Mitral valve resistance determines hemodynamic consequences of severe rheumatic mitral stenosis and immediate outcomes of percutaneous valvuloplasty.

PubMed

Sanati, Hamidreza; Zolfaghari, Reza; Samiei, Niloufar; Rezaei, Yousef; Chitsazan, Mitra; Zahedmehr, Ali; Shakerian, Farshad; Kiani, Reza; Firouzi, Ata; Rezaei Tabrizi, Reza

2017-02-01

The mitral valve area (MVA) poorly reflects the hemodynamic status of (MS). In this study, we compared the MVA with mitral valve resistance (MVR) with regard to the determination of hemodynamic consequences of MS and the immediate outcomes of percutaneous balloon mitral valvuloplasty (PBMV). In a prospective study, 36 patients with severe rheumatic MS with left ventricular ejection fraction (LVEF) >50% were evaluated. They underwent transthoracic echocardiography (TTE) and catheterization. The MVA was measured by two-dimensional planimetry and pressure half-time (PHT), and the MVR was calculated using the equation: 1333 × transmitral pressure gradient mean transmitral diastolic flow rate. The patients' mean age was 47.8±10.5 years. MVR ≥140.6 dynes·s/cm 5 detected systolic pulmonary arterial pressure (sPAP) >55 mm Hg with a sensitivity of 100% and a specificity of 74%. The sensitivity and specificity of MVA<0.75 cm 2 to discriminate elevated sPAP were 81% and 89%, respectively. PHT ≥323.5 mseconds had a sensitivity of 78% and a specificity of 96% to detect an elevated sPAP. To predict a successful PBMV, preprocedural MVR ≥106.1 dynes·s/cm 5 had a sensitivity of 100% and a specificity of 67% (area under the curve [AUC]=0.763; 95% confidence interval [CI]=0.520-1.006; P=.034); preprocedural MVA <0.95 cm 2 had a sensitivity of 78% and a specificity of 73% (AUC=0.730; 95% CI=0.503-0.956; P=.065); and preprocedural PHT ≥210.5 mseconds had a sensitivity of 73% and a specificity of 78% (AUC=0.707; 95% CI=0.474-0.941; P=.095). MVR seems to be more accurate than MVA in determining the hemodynamic consequences of severe MS as determined by sPAP. In addition, preprocedural MVR detected successful PBMVs. © 2017, Wiley Periodicals, Inc.

The accuracy of burn diagnosis codes in health administrative data: A validation study.

PubMed

Mason, Stephanie A; Nathens, Avery B; Byrne, James P; Fowler, Rob; Gonzalez, Alejandro; Karanicolas, Paul J; Moineddin, Rahim; Jeschke, Marc G

2017-03-01

Health administrative databases may provide rich sources of data for the study of outcomes following burn. We aimed to determine the accuracy of International Classification of Diseases diagnoses codes for burn in a population-based administrative database. Data from a regional burn center's clinical registry of patients admitted between 2006-2013 were linked to administrative databases. Burn total body surface area (TBSA), depth, mechanism, and inhalation injury were compared between the registry and administrative records. The sensitivity, specificity, and positive and negative predictive values were determined, and coding agreement was assessed with the kappa statistic. 1215 burn center patients were linked to administrative records. TBSA codes were highly sensitive and specific for ≥10 and ≥20% TBSA (89/93% sensitive and 95/97% specific), with excellent agreement (κ, 0.85/κ, 0.88). Codes were weakly sensitive (68%) in identifying ≥10% TBSA full-thickness burn, though highly specific (86%) with moderate agreement (κ, 0.46). Codes for inhalation injury had limited sensitivity (43%) but high specificity (99%) with moderate agreement (κ, 0.54). Burn mechanism had excellent coding agreement (κ, 0.84). Administrative data diagnosis codes accurately identify burn by burn size and mechanism, while identification of inhalation injury or full-thickness burns is less sensitive but highly specific. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.

Accuracy criteria voltage electrocardiography left ventricular hypertrophy to distinguish types of left ventricular hypertrophy geometry

NASA Astrophysics Data System (ADS)

Tumbur, O.; Safri, Z.; Hassan, R.

2018-03-01

Different types of left ventricular hypertrophy geometry are associated with different risk of cardiovascular disease. The purpose of this study was to determine the role of various ECG voltages of LVH to distinguish the type of LVH geometry. A cross-sectional study from June to November 2015, 100 patients in Adam Malik Hospital Medan. The result of LVH ECG criteria of Sokolow-Lyon was not met then obtained normal left ventricular geometry with 60% sensitivity, 72.22% specificity, and 71% accuracy. The eccentric type of LVH is obtained when the Cornel Voltage is not met; the sensitivity is 25%, specificity 71.88%, and 55% accuracy. Concentric geometric hypertrophy when the RV6/V5> 1 ratio is satisfied, the sensitivity is 55.56%, specificity 56.36%, and 56% accuracy. The RV6/V5>1 ratio was not met, the concentric geometry type of hypertrophy remodeling was determined with a sensitivity of 55.56%, specificity 49.45%, and 50% accuracy. Conclusions, various LVHECG criteria distinguish the type of LVH geometry. Sokolow-Lyon and Cornel Voltage sensitivity and specificity are better than the RV6/V5 ratio.

Cost-effectiveness of various methods of diagnosing hypersensitivity to Alternaria.

PubMed

Escudero, A I; Sánchez-Guerrero, I M; Mora, A M; Soriano, V; López, J D; García, F J; Negro, J M; Hernández, J; Pagán, J A

1993-01-01

This study was undertaken for two reasons: 1) It is more difficult to diagnose hypersensitivity to molds than to other allergens, so an evaluation of diagnostic tests was needed. 2) Alternaria is the principal cause of mold sensitization in our area. Sixty-six patients (20 +/- 4 years) were selected and divided into two groups. Group A was made up of patients with rhinitis and/or asthma due to Alternaria sensitization. Group B consisted of patients sensitized to other allergens and patients with nonrespiratory allergic disorders. Skin tests (prick and intradermal), challenge tests (conjunctival, nasal, and bronchial), and specific IgE determination were performed for all patients. A biologically standardized extract of Alternaria tenuis (Alergia e Inmunología Abelló, S. A., Madrid, Spain) obtained from a single batch was used for all tests. Our diagnostic criterion was a clinical history of rhinitis or asthma that coincided with the results of nasal/bronchial challenge. The diagnostic value of the other tests was compared to this criterion. In the group of rhinitic patients, skin tests and conjunctival challenge were more sensitive than specific IgE determination. In asthmatic patients, the most sensitive techniques were nasal and conjunctival challenges, followed by prick and intradermal skin tests, and, lastly, serum specific IgE determination. When rhinitis and asthma were considered jointly, the most sensitive test was conjunctival challenge, followed by skin-prick and intradermal tests. All tests had the same specificity, regardless of disorder. Nasal challenge was positive in all patients. Skin tests are easy to perform, cheap, non-traumatic for the patient, and sufficiently specific and sensitive for the diagnosis of Alternaria hypersensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative real-time PCR technique for the identification of E. coli residual DNA in streptokinase recombinant product.

PubMed

Fazelahi, Mansoureh; Kia, Vahid; Kaghazian, Hooman; Paryan, Mahdi

2017-11-26

Recombinant streptokinase is a biopharmaceutical which is usually produced in E. coli. Residual DNA as a contamination and risk factor may remain in the product. It is necessary to control the production procedure to exclude any possible contamination. The aim of the present study was to develop a highly specific and sensitive quantitative real-time PCR-based method to determine the amount of E. coli DNA in recombinant streptokinase. A specific primers and a probe was designed to detect all strains of E. coli. To determine the specificity, in addition to using NCBI BLASTn, 28 samples including human, bacterial, and viral genomes were used. The results confirmed that the assay detects no genomic DNA but E. coli's and the specificity was determined to be 100%. To determine the sensitivity and limit of detection of the assay, a 10-fold serial dilution (10 1 to 10 7 copies/µL) was tested in triplicate. The sensitivity of the test was determined to be 101 copies/µL or 35 fg/µL. Inter-assay and intra-assay were determined to be 0.86 and 1.69%, respectively. Based on the results, this assay can be used as an accurate method to evaluate the contamination of recombinant streptokinase in E. coli.

Protein determination: a comparison of several methods.

PubMed

Hocman, G; Palkovic, M

1977-01-01

A comparison of four methods for the determination of total proteins is presented from the following points of view: - sensitivity; - specificity; - amount of work, chemicals, time and equipment needed for the performance of the determination. The following tests have been examined; Tombs' (absorbancy at 210 nm); Waddell's (difference in absorbancy between 215 and 225 nm); Warburg's (absorbancy at 280 nm); Lowry's (absorbancy at 500 nm after the reaction with phenol reagent). The authors recommend Tombs' method for its outstanding sensitivity, specificity and simplicity as the best of the four.

Comparison of four methods to assess colostral IgG concentration in dairy cows.

PubMed

Chigerwe, Munashe; Tyler, Jeff W; Middleton, John R; Spain, James N; Dill, Jeffrey S; Steevens, Barry J

2008-09-01

To determine sensitivity and specificity of 4 methods to assess colostral IgG concentration in dairy cows and determine the optimal cutpoint for each method. Cross-sectional study. 160 Holstein dairy cows. 171 composite colostrum samples collected within 2 hours after parturition were used in the study. Test methods used to estimate colostral IgG concentration consisted of weight of the first milking, 2 hydrometers, and an electronic refractometer. Results of the test methods were compared with colostral IgG concentration determined by means of radial immunodiffusion. For each method, sensitivity and specificity for detecting colostral IgG concentration < 50 g/L were calculated across a range of potential cutpoints, and the optimal cutpoint for each test was selected to maximize sensitivity and specificity. At the optimal cutpoint for each method, sensitivity for weight of the first milking (0.42) was significantly lower than sensitivity for each of the other 3 methods (hydrometer 1, 0.75; hydrometer 2, 0.76; refractometer, 0.75), but no significant differences were identified among the other 3 methods with regard to sensitivity. Specificities at the optimal cutpoint were similar for all 4 methods. Results suggested that use of either hydrometer or the electronic refractometer was an acceptable method of screening colostrum for low IgG concentration; however, the manufacturer-defined scale for both hydrometers overestimated colostral IgG concentration. Use of weight of the first milking as a screening test to identify bovine colostrum with inadequate IgG concentration could not be justified because of the low sensitivity.

Optimizing the interpretation of CT for appendicitis: modeling health utilities for clinical practice.

PubMed

Blackmore, C Craig; Terasawa, Teruhiko

2006-02-01

Error in radiology can be reduced by standardizing the interpretation of imaging studies to the optimum sensitivity and specificity. In this report, the authors demonstrate how the optimal interpretation of appendiceal computed tomography (CT) can be determined and how it varies in different clinical scenarios. Utility analysis and receiver operating characteristic (ROC) curve modeling were used to determine the trade-off between false-positive and false-negative test results to determine the optimal operating point on the ROC curve for the interpretation of appendicitis CT. Modeling was based on a previous meta-analysis for the accuracy of CT and on literature estimates of the utilities of various health states. The posttest probability of appendicitis was derived using Bayes's theorem. At a low prevalence of disease (screening), appendicitis CT should be interpreted at high specificity (97.7%), even at the expense of lower sensitivity (75%). Conversely, at a high probability of disease, high sensitivity (97.4%) is preferred (specificity 77.8%). When the clinical diagnosis of appendicitis is equivocal, CT interpretation should emphasize both sensitivity and specificity (sensitivity 92.3%, specificity 91.5%). Radiologists can potentially decrease medical error and improve patient health by varying the interpretation of appendiceal CT on the basis of the clinical probability of appendicitis. This report is an example of how utility analysis can be used to guide radiologists in the interpretation of imaging studies and provide guidance on appropriate targets for the standardization of interpretation.

Detection of CIN by naked eye visualization after application of acetic acid.

PubMed

Londhe, M; George, S S; Seshadri, L

1997-06-01

A prospective study was undertaken to determine the sensitivity and specificity of acetic application to the cervix followed by naked eye visualization as a screening test for detection of cervical intraepithelial neoplasia. Three hundred and seventy two sexually active woman in the reproductive age group were studied. All the women underwent Papanicolaou test, acetic acid test and colposcopy. One hundred and seventy five woman were acetic acid test negative, 197 women were acetic acid test positive. The sensitivity of acetic acid test was 72.4%, specificity 54% and false negative rate 15.2%, as compared to papanicolaou test which had a sensitivity of 13.2%, specificity of 96.3% and false negative rate of 24.4%. The advantage of the acetic acid test lies in its easy technique, low cost and high sensitivity which are important factors for determining the efficacy of any screening programme in developing countries.

Sensitivity of different Trypanosoma vivax specific primers for the diagnosis of livestock trypanosomosis using different DNA extraction methods.

PubMed

Gonzales, J L; Loza, A; Chacon, E

2006-03-15

There are several T. vivax specific primers developed for PCR diagnosis. Most of these primers were validated under different DNA extraction methods and study designs leading to heterogeneity of results. The objective of the present study was to validate PCR as a diagnostic test for T. vivax trypanosomosis by means of determining the test sensitivity of different published specific primers with different sample preparations. Four different DNA extraction methods were used to test the sensitivity of PCR with four different primer sets. DNA was extracted directly from whole blood samples, blood dried on filter papers or blood dried on FTA cards. The results showed that the sensitivity of PCR with each primer set was highly dependant of the sample preparation and DNA extraction method. The highest sensitivities for all the primers tested were determined using DNA extracted from whole blood samples, while the lowest sensitivities were obtained when DNA was extracted from filter paper preparations. To conclude, the obtained results are discussed and a protocol for diagnosis and surveillance for T. vivax trypanosomosis is recommended.

Dynamic MR imaging of soft tissue tumors with assessment of the rate and character of lesion enhancement.

PubMed

Tacikowska, Małgorzata

2002-02-01

The aim of this study was to analyze the diagnostic usefulness of dynamic MRI with determination of the coefficient of enhancement rate and the character of tumor enhancement, and to assess both parameters in the differentiation of malignant lesions. The material consisted of 45 patients (30 sarcomas, 15 non-malignant lesions), age 16-64 years. MRI was done using an Elscint 2T unit, gradient echo techniques, apex angle 80 degrees. The repetition time (TR) was 80-200 ms, the echo time (TE) was 2-6 ms, 1 excitation; the acquisition time (TA) was 70-80 ms. The coefficient of tissue enhancement rate was calculated in the region of interest, and expressed as percent per second (erc%/s). The limit value of erc%/s was determined. The sensitivity and specificity of MRI were calculated in the differentiation of malignant tumors. The method of contrast filling of the tumors was assessed in successive phases after administration of gadolinium Gd-DTPA. Dynamic MRI with determination of the index of tumor enhancement rate is highly sensitive (93%) and specific (73%) in the differentiation of malignant and benign lesions. The usefulness of the assessment of tumor enhancement character was not confirmed, since the sensitivity and specificity were 73% and 33%. Dynamic MRI with determination of erc%/s and tumor enhancement character is highly sensitive (93%) and specific (87%). Dynamic MRI with determination of erc%/s and tumor enhancement character is the best method for differential diagnosis.

Rapid quantification of color vision: the cone contrast test.

PubMed

Rabin, Jeff; Gooch, John; Ivan, Douglas

2011-02-09

To describe the design, specificity, and sensitivity of the cone contrast test (CCT), a computer-based, cone-specific (L, M, S) contrast sensitivity test for diagnosing type and severity of color vision deficiency (CVD). The CCT presents a randomized series of colored letters visible only to L, M or S cones in decreasing steps of cone contrast to determine L, M, and S letter-recognition thresholds. Sensitivity and specificity were determined by retrospective comparison of CCT scores to anomaloscope and pseudoisochromatic plate (PIP) results in 1446 applicants for pilot training. CVD was detected in 49 (3.4%) of 1446 applicants with hereditary red-green (protan or deutan) CVD detected in 47 (3.5%) of 1359 men and blue-yellow (tritan) in 2 of 1446. In agreement with the anomaloscope, the CCT showed 100% sensitivity for detection and categorization of CVD (40 deutan, 7 protan, 2 tritan). PIP testing showed lower sensitivity (80% detected; 20% missed) due in part to the applicant's prior experience and/or pretest preparation. CCT specificity for confirming normal color vision was 100% for L and M cone tests and 99.8% for S cones. The CCT has sensitivity and specificity comparable to anomaloscope testing and exceeds PIP sensitivity in practiced observers. The CCT provides a rapid (6 minutes), clinically expedient, measure of color vision for quantifying normal color performance, diagnosing type and severity of hereditary deficiency, and detection of acquired sensitivity loss due to ocular, neurologic, and/or systemic disease, as well as injury and physiological stressors, such as altitude and fatigue.

Sensitivity and specificity of the lymphocyte transformation test in drug reaction with eosinophilia and systemic symptoms causality assessment.

PubMed

Cabañas, R; Calderón, O; Ramírez, E; Fiandor, A; Caballero, T; Heredia, R; Herranz, P; Madero, R; Quirce, S; Bellón, T

2018-03-01

Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe delayed hypersensitivity reaction. The determination of drug causality is complex. The lymphocyte transformation test (LTT) has been reported positive in more than 50% of DRESS cases. Nevertheless, the sensitivity and specificity of LTT specifically in DRESS have not yet been established. Rechallenge with the culprit drug is contraindicated and cannot be used as gold standard for sensitivity and specificity determination. To estimate the sensitivity and specificity of LTT in a clinically defined series of patients with DRESS. Some 41 patients diagnosed with DRESS were included in the study. The results of the algorithm of the Spanish Pharmacovigilance System were used as the standard for a correct diagnosis of drug causality. A standard LTT was performed with involved drugs in acute or recovery samples. A stimulation index (SI) ≥2 in at least one concentration except for beta-lactams (SI ≥3) and contrast media (SI ≥4) was considered positive. Contingency tables and ROC curves were used for analysis. Sensitivity and specificity of LTT in the recovery phase of DRESS were 73% and 82%, respectively, whereas in the acute phase, they were only 40% and 30%, respectively. Comparison of skin tests and LTT confirmed a higher sensitivity and specificity of LTT in DRESS. LTT showed high sensitivity (S) and specificity (Sp) for anticonvulsants (S 100%, Sp 100%; P = .008), anti-TB drugs (S 87.5%, Sp 100%; P = .004), and beta-lactams (S 73%, Sp 100%; P = .001). ROC curves revealed that the best criteria for LTT positivity for all drugs are SI ≥2 in at least one concentration, increasing overall sensitivity to 80%, and for beta-lactams from 73% to 92%. LTT is a good diagnostic tool for drug causality in DRESS, mainly when performed in the recovery phase. © 2017 John Wiley & Sons Ltd.

A systematic review of the sensitivity and specificity of the toe-brachial index for detecting peripheral artery disease.

PubMed

Tehan, Peta Ellen; Santos, Derek; Chuter, Vivienne Helaine

2016-08-01

The toe-brachial index (TBI) is used as an adjunct to the ankle-brachial index (ABI) for non-invasive lower limb vascular screening. With increasing evidence suggesting limitations of the ABI for diagnosis of vascular complications, particularly in specific populations including diabetes cohorts, the TBI is being used more widely. The aim of this review was to determine the sensitivity and specificity of the TBI for detecting peripheral artery disease (PAD) in populations at risk of this disease. A database search was conducted to identify current work relating to the sensitivity and specificity of toe-brachial indices up to July 2015. Only studies using valid diagnostic imaging as a reference standard were included. The QUADAS-2 tool was used to critically appraise included articles. Seven studies met the inclusion criteria. Sensitivity of the TBI for PAD was reported in all seven studies and ranged from 45% to 100%; specificity was reported by five studies only and ranged from 16% to 100%. In conclusion, this review suggests that the TBI has variable diagnostic accuracy for the presence of PAD in specific populations at risk of developing the disease. There was a notable lack of large-scale diagnostic accuracy studies determining the diagnostic accuracy of the TBI in detecting PAD in different at-risk cohorts. However, standardised normal values need to be established for the TBI to conclusively determine the diagnostic accuracy of this test. © The Author(s) 2016.

[Validation of the nutritional index in Mexican pre-teens with the sensitivity and specificity method].

PubMed

Saucedo-Molina, T J; Gómez-Peresmitré, G

1998-01-01

To determine the diagnostic validity of the nutritional index (NI) in a sample of Mexican preadolescents. A total of 256 preadolescents, between 10 and 12 years old, male and female, students from Mexico City, were used to establish the diagnostic validity of NI using the sensitivity and specificity method. The findings show that the conventional NI cut-off points showed good sensitivity and specificity for the diagnosis of low weight, normality and obesity but not for overweight. When the cut-off points of NI were normalized, the sensitivity, specificity and prediction potency values were more suitable in all categories. When working with preadolescents, it is better to use the new cut-off points of NI, to obtain more reliable diagnosis.

Requirements for Minimum Sample Size for Sensitivity and Specificity Analysis

PubMed Central

Adnan, Tassha Hilda

2016-01-01

Sensitivity and specificity analysis is commonly used for screening and diagnostic tests. The main issue researchers face is to determine the sufficient sample sizes that are related with screening and diagnostic studies. Although the formula for sample size calculation is available but concerning majority of the researchers are not mathematicians or statisticians, hence, sample size calculation might not be easy for them. This review paper provides sample size tables with regards to sensitivity and specificity analysis. These tables were derived from formulation of sensitivity and specificity test using Power Analysis and Sample Size (PASS) software based on desired type I error, power and effect size. The approaches on how to use the tables were also discussed. PMID:27891446

Assessment of Relationship-Specific Incentive and Threat Sensitivities: Predicting Satisfaction and Affect in Adult Intimate Relationships

ERIC Educational Resources Information Center

Laurenceau, Jean-Philippe; Kleinman, Brighid M.; Kaczynski, Karen J.; Carver, Charles S.

2010-01-01

Self-report scales assessing relationship-specific incentive and threat sensitivity were created. Initial tests of factor structure and associations with relationship quality were conducted in a sample of persons in intimate relationships (Study 1). Associations with conceptually related measures were examined to determine convergent and…

The Effect of Audience Specification on Writing Anxiety, Performance, and Sensitivity to Audience.

ERIC Educational Resources Information Center

Hurd, Rhynette N.

One hundred seventy-nine students enrolled in a first-year college level composition course were subjects in a study of the effects of four levels of audience specification on writing anxiety, performance, and sensitivity to audience. Subjects completed the Writing Apprehension Test, which determined levels of writing apprehension, and then…

International ring trial to detect anti-Trichinella IgG by ELISA on pig sera.

USDA-ARS?s Scientific Manuscript database

In the present study, the sensitivity and specificity of the ELISA assay determined by the CRLP validation was 100% and 98.29%, respectively. The assay was reproducible, moreover, based on the receiver-operator characteristic (ROC) curve, the sensitivity and specificity of the assay reached 97.5% an...

ADHD Is Highly Prevalent in Patients Seeking Treatment for Cannabis Use Disorders.

PubMed

Notzon, Daniel P; Pavlicova, Martina; Glass, Andrew; Mariani, John J; Mahony, Amy L; Brooks, Daniel J; Levin, Frances R

2016-03-31

To estimate the prevalence of ADHD and determine an effective screening test for ADHD in a population-seeking treatment for cannabis use disorders. The Conners Adult ADHD Diagnostic Interview forDiagnostic and Statistical Manual of Mental Disorders, Fourth Edition(DSM-IV; CAADID) was used to generate sensitivity and specificity data for ADHD screening tests, which were then administered to 99 participants seeking treatment for cannabis use disorders to estimate ADHD prevalence. The prevalence estimated from the Wender Utah Rating Scale (WURS) was 45% (sensitivity = 0.88, sensitivity of 0.75), from the Conners Adult ADHD Rating Scale (CAARS) 34% (sensitivity = 0.80, specificity = 0.91), from the WURS + CAARS 36% (sensitivity = 0.71, specificity = 0.95), and from the Adult ADHD Self-Report Scale (ASRS) 46% (sensitivity = 0.61, specificity = 0.86). The prevalence of ADHD in adults seeking treatment for cannabis use disorders is estimated to be between 34% and 46%. The WURS paired with the CAARS provides excellent sensitivity and specificity for the diagnosis of ADHD in this population. © The Author(s) 2016.

Differentiation between diverticulitis and colorectal cancer: quantitative CT perfusion measurements versus morphologic criteria--initial experience.

PubMed

Goh, Vicky; Halligan, Steve; Taylor, Stuart A; Burling, David; Bassett, Paul; Bartram, Clive I

2007-02-01

To determine whether computed tomographic (CT) perfusion measurements in prospectively recruited patients can be used to differentiate between diverticulitis and colorectal cancer and to compare this discrimination with that of standard morphologic criteria. After institutional review board approval and written informed consent were obtained, 60 patients (24 men, 36 women; mean age, 69 years; range, 33.5-90.4 years; 20 patients with cancer, 20 with diverticulitis, and 20 with inactive diverticular disease) underwent CT perfusion imaging at the level of the colonic abnormality, and perfusion parameters were calculated. Analysis of variance was used to investigate any differences in perfusion between the patient groups. Two independent observers also analyzed an abdominopelvic CT study obtained immediately after the CT perfusion study and noted standard morphologic criteria for differential diagnosis. The sensitivity and specificity of CT perfusion measurements for determining the diagnostic category were compared with morphologic criteria by means of multivariate analysis to identify the most discriminatory criteria. Mean blood volume, blood flow, transit time, and permeability were significantly different between patients with cancer and those with diverticulitis (P < .0001); patients with cancer had the highest blood volume, blood flow, and permeability and the shortest transit time. The most discriminatory criteria for determining diagnostic category were blood volume, transit time, permeability, and presence of pericolonic nodes (P = .05, .02, .04, and .02, respectively). Blood volume and blood flow each had a sensitivity of 80% and had specificity of 70% and 75%, respectively, for cancer in comparison with standard morphologic criteria: less than 5 cm of bowel involvement (45% sensitivity, 95% specificity), presence of a mass (85% sensitivity, 90% specificity), pericolonic inflammation (75% sensitivity, 5% specificity), and pericolonic nodes (90% sensitivity, 45% specificity). CT perfusion measurements enable differentiation and better discrimination, in comparison with morphologic criteria, between cancer and diverticulitis. (c) RSNA, 2007.

Determining sensitivity/specificity of virtual reality-based neuropsychological tool for detecting residual abnormalities following sport-related concussion.

PubMed

Teel, Elizabeth; Gay, Michael; Johnson, Brian; Slobounov, Semyon

2016-05-01

Computer-based neuropsychological (NP) evaluation is an effective clinical tool used to assess cognitive function which complements the clinical diagnosis of a concussion. However, some researchers and clinicians argue its lack of ecological validity places limitations on externalizing results to a sensory rich athletic environment. Virtual reality-based NP assessment offers clinical advantages using an immersive environment and evaluating domains not typically assessed by traditional NP assessments. The sensitivity and specificity of detecting lingering cognitive abnormalities was examined on components of a virtual reality-based NP assessment battery to cohort affiliation (concussed vs. controls). Data were retrospectively gathered on 128 controls (no concussion) and 24 concussed college-age athletes on measures of spatial navigation, whole body reaction, attention, and balance in a virtual environment. Concussed athletes were tested within 10 days (M = 8.33, SD = 1.06) of concussion and were clinically asymptomatic at the time of testing. A priori alpha level was set at 0.05 for all tests. Spatial navigation (sensitivity 95.8%/specificity 91.4%, d = 1.89), whole body reaction time (sensitivity 95.2%/specificity 89.1%, d = 1.50) and combined virtual reality modules (sensitivity 95.8%,/specificity 96.1%, d = 3.59) produced high sensitivity/specificity values when determining performance-based variability between groups. Use of a virtual reality-based NP platform can detect lingering cognitive abnormalities resulting from concussion in clinically asymptomatic participants. Virtual reality NP platforms may compliment the traditional concussion assessment battery by providing novel information. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Individual variability of human olfactory sensitivity to volatile steroids: Environmental and genetic factors.

PubMed

Voznessenskaya, V V; Klyuchnikova, M A

2017-03-01

The sensitivity to androstenone and possible factors, determining the sensitivity were investigated for the large sample of inhabitants of central Russia (n = 860). Specific anosmia was detected in 48.8% of subjects. Women were more sensitive to androstenone than men. The proportion of men, but not women perceiving the smell of androstenone as a strong one in the concentration used decreased with age. Smoking, blood group, or ethnicity had no significant effect on the expression of specific anosmia and the perception of androstenone odor intensity.

’Coxiella Burnetii’ Vaccine Development: Lipopolysaccharide Structural Analysis

DTIC Science & Technology

1991-02-20

Analytical instrumentation and methodology is presented for the determination of endotoxin -related structures at much improved sensitivity and... ENDOTOXIN CHARACTERIZATION BY SFC .......................... 10 III. COXIELLA BURNETII LPS CHARACTERIZATION A. EXPERIMENTAL...period for the determination of endotoxin -related structures at much improved sensitivity and specificity. Reports, and their applications, are listed in

Geochemistry of biomolecules

NASA Technical Reports Server (NTRS)

Bonner, J.

1976-01-01

A highly sensitive fluorometric technique is developed for the determination of biological and geo-organic compounds in ancient sediments and extraterrestrial samples. This technique is used to establish chemical evidence for fossil pigments in an extraterrestrial sample. Also developed is a highly sensitive and specific fluorometric method for the determination of total primary amine nitrogen in soil samples.

Designing Medical Tests: The Other Side of Bayes' Theorem

ERIC Educational Resources Information Center

Ross, Andrew M.

2012-01-01

To compute the probability of having a disease, given a positive test result, is a standard probability problem. The sensitivity and specificity of the test must be given and the prevalence of the disease. We ask how a test-maker might determine the tradeoff between sensitivity and specificity. Adding hypothetical costs for detecting or failing to…

[Diagnostic strategies in the Tuberculosis Clinic of the Hospital General La Raza National Medical Center].

PubMed

Flores-Ibarra, Alberto Alejandro; Ochoa-Vázquez, María Dolores; Sánchez-Tec, Georgina Alejandra

2016-01-01

In order to diagnose TB infection, tuberculin skin test and interferon gamma release assay are available. The tuberculin test has a sensitivity of 99 % and a specificity of 95 %. For the detection of interferon gamma in blood there are currently two tests available: TBGold QuantiFERON-In-Tube (with a sensitivity of 0.70 and a specificity of 0.90), and T-SPOT-TB (sensitivity 0.90 and specificity 0.93). To diagnose the disease, a microscopy of direct smears for acid-fast bacilli is used if the physician is facing an extensive cavitary lung disease due to M. tuberculosis (this test has a high sensitivity: 80-90 %). The most common staining techniques used are Ziehl-Neelsen and Kinyoun, and the fluorescent technique, auramine-rhodamine. The culture is the gold standard and it has a sensitivity of 80 % and a specificity over 90 %, but the results take weeks. The nucleic acid amplification test has an overall sensitivity and specificity of 0.85 and 0.97, respectively. In the presence of a pleural effusion is necessary to perform a pleural biopsy for culture with a sensitivity of 85 % if it is percutaneous and 98 % if it was taken by thoracoscopy. The adenosine deaminase can be determined in pleural fluid with a sensitivity and specificity of 95 %.

A Theory of Self- Nonself Discrimination

ERIC Educational Resources Information Center

Bretscher, Peter; Cohn, Melvin

1970-01-01

Theoretical model suggests antigen-sensitive cells produce antibodies only when two antigenic determinants are recognized, and explains self-nonself discrimination by antibody system. Specific antigen-sensitive cells accumulate in absence of foreign antigens and co-operate to induce antibodies if antigen enter the body; but antigen-sensitive cells…

Optimal cut-off of homeostasis model assessment of insulin resistance (HOMA-IR) for the diagnosis of metabolic syndrome: third national surveillance of risk factors of non-communicable diseases in Iran (SuRFNCD-2007).

PubMed

Esteghamati, Alireza; Ashraf, Haleh; Khalilzadeh, Omid; Zandieh, Ali; Nakhjavani, Manouchehr; Rashidi, Armin; Haghazali, Mehrdad; Asgari, Fereshteh

2010-04-07

We have recently determined the optimal cut-off of the homeostatic model assessment of insulin resistance for the diagnosis of insulin resistance (IR) and metabolic syndrome (MetS) in non-diabetic residents of Tehran, the capital of Iran. The aim of the present study is to establish the optimal cut-off at the national level in the Iranian population with and without diabetes. Data of the third National Surveillance of Risk Factors of Non-Communicable Diseases, available for 3,071 adult Iranian individuals aging 25-64 years were analyzed. MetS was defined according to the Adult Treatment Panel III (ATPIII) and International Diabetes Federation (IDF) criteria. HOMA-IR cut-offs from the 50th to the 95th percentile were calculated and sensitivity, specificity, and positive likelihood ratio for MetS diagnosis were determined. The receiver operating characteristic (ROC) curves of HOMA-IR for MetS diagnosis were depicted, and the optimal cut-offs were determined by two different methods: Youden index, and the shortest distance from the top left corner of the curve. The area under the curve (AUC) (95%CI) was 0.650 (0.631-0.670) for IDF-defined MetS and 0.683 (0.664-0.703) with the ATPIII definition. The optimal HOMA-IR cut-off for the diagnosis of IDF- and ATPIII-defined MetS in non-diabetic individuals was 1.775 (sensitivity: 57.3%, specificity: 65.3%, with ATPIII; sensitivity: 55.9%, specificity: 64.7%, with IDF). The optimal cut-offs in diabetic individuals were 3.875 (sensitivity: 49.7%, specificity: 69.6%) and 4.325 (sensitivity: 45.4%, specificity: 69.0%) for ATPIII- and IDF-defined MetS, respectively. We determined the optimal HOMA-IR cut-off points for the diagnosis of MetS in the Iranian population with and without diabetes.

Sensitivity of frozen section histology for identifying Propionibacterium acnes infections in revision shoulder arthroplasty.

PubMed

Grosso, Matthew J; Frangiamore, Salvatore J; Ricchetti, Eric T; Bauer, Thomas W; Iannotti, Joseph P

2014-03-19

Propionibacterium acnes is a clinically relevant pathogen with total shoulder arthroplasty. The purpose of this study was to determine the sensitivity of frozen section histology in identifying patients with Propionibacterium acnes infection during revision total shoulder arthroplasty and investigate various diagnostic thresholds of acute inflammation that may improve frozen section performance. We reviewed the results of forty-five patients who underwent revision total shoulder arthroplasty. Patients were divided into the non-infection group (n = 15), the Propionibacterium acnes infection group (n = 18), and the other infection group (n = 12). Routine preoperative testing was performed and intraoperative tissue culture and frozen section histology were collected for each patient. The histologic diagnosis was determined by one pathologist for each of the four different thresholds. The absolute maximum polymorphonuclear leukocyte concentration was used to construct a receiver operating characteristics curve to determine a new potential optimal threshold. Using the current thresholds for grading frozen section histology, the sensitivity was lower for the Propionibacterium acnes infection group (50%) compared with the other infection group (67%). The specificity of frozen section was 100%. Using a receiver operating characteristics curve, an optimized threshold was found at a total of ten polymorphonuclear leukocytes in five high-power fields (400×). Using this threshold, the sensitivity of frozen section for Propionibacterium acnes was increased to 72%, and the specificity remained at 100%. Using current histopathology grading systems, frozen sections were specific but showed low sensitivity with respect to the Propionibacterium acnes infection. A new threshold value of a total of ten or more polymorphonuclear leukocytes in five high-power fields may increase the sensitivity of frozen section, with minimal impact on specificity.

Sensitivity and Specificity of Suspected Case Definition Used during West Africa Ebola Epidemic

PubMed Central

Champaloux, Steven W.; Keïta, Sakoba; Martel, Lise; Bilivogui, Pepe; Knust, Barbara; McCollum, Andrea M.

2018-01-01

Rapid early detection and control of Ebola virus disease (EVD) is contingent on accurate case definitions. Using an epidemic surveillance dataset from Guinea, we analyzed an EVD case definition developed by the World Health Organization (WHO) and used in Guinea. We used the surveillance dataset (March–October 2014; n = 2,847 persons) to identify patients who satisfied or did not satisfy case definition criteria. Laboratory confirmation determined cases from noncases, and we calculated sensitivity, specificity and predictive values. The sensitivity of the defintion was 68.9%, and the specificity of the definition was 49.6%. The presence of epidemiologic risk factors (i.e., recent contact with a known or suspected EVD case-patient) had the highest sensitivity (74.7%), and unexplained deaths had the highest specificity (92.8%). Results for case definition analyses were statistically significant (p<0.05 by χ2 test). Multiple components of the EVD case definition used in Guinea contributed to improved overall sensitivity and specificity. PMID:29260687

Diagnosis of knee injuries: comparison of the physical examination and magnetic resonance imaging with the findings from arthroscopy☆

PubMed Central

Orlando Júnior, Nilton; de Souza Leão, Marcos George; de Oliveira, Nelson Henrique Carvalho

2015-01-01

Objectives To ascertain the sensitivity, specificity, accuracy and concordance of the physical examination (PE) and magnetic resonance imaging (MRI) in comparison with arthroscopy, in diagnosing knee injuries. Methods Prospective study on 72 patients, with evaluation and comparison of PE, MRI and arthroscopic findings, to determine the concordance, accuracy, sensitivity and specificity. Results PE showed sensitivity of 75.00%, specificity of 62.50% and accuracy of 69.44% for medial meniscal (MM) lesions, while it showed sensitivity of 47.82%, specificity of 93.87% and accuracy of 79.16% for lateral meniscal (LM) lesions. For anterior cruciate ligament (ACL) injuries, PE showed sensitivity of 88.67%, specificity of 94.73% and accuracy of 90.27%. For MM lesions, MRI showed sensitivity of 92.50%, specificity of 62.50% and accuracy of 69.44%, while for LM injuries, it showed sensitivity of 65.00%, specificity of 88.46% and accuracy of 81.94%. For ACL injuries, MRI showed sensitivity of 86.79%, specificity of 73.68% and accuracy of 83.33%. For ACL injuries, the best concordance was with PE, while for MM and LM lesions, it was with MRI (p < 0.001). Conclusions Meniscal and ligament injuries can be diagnosed through careful physical examination, while requests for MRI are reserved for complex or doubtful cases. PE and MRI used together have high sensitivity for ACL and MM lesions, while for LM lesions the specificity is higher. Level of evidence II – Development of diagnostic criteria on consecutive patients (with universally applied reference “gold” standard). PMID:27218085

Sensitivity and Specificity of OCT Angiography to Detect Choroidal Neovascularization.

PubMed

Faridi, Ambar; Jia, Yali; Gao, Simon S; Huang, David; Bhavsar, Kavita V; Wilson, David J; Sill, Andrew; Flaxel, Christina J; Hwang, Thomas S; Lauer, Andreas K; Bailey, Steven T

2017-01-01

To determine the sensitivity and specificity of optical coherence tomography angiography (OCTA) in the detection of choroidal neovascularization (CNV) in age-related macular degeneration (AMD). Prospective case series. Prospective series of seventy-two eyes were studied, which included eyes with treatment-naive CNV due to AMD, non-neovascular AMD, and normal controls. All eyes underwent OCTA with a spectral domain (SD) OCT (Optovue, Inc.). The 3D angiogram was segmented into separate en face views including the inner retinal angiogram, outer retinal angiogram, and choriocapillaris angiogram. Detection of abnormal flow in the outer retina served as candidate CNV with OCTA. Masked graders reviewed structural OCT alone, en face OCTA alone, and en face OCTA combined with cross-sectional OCTA for the presence of CNV. The sensitivity and specificity of CNV detection compared to the gold standard of fluorescein angiography (FA) and OCT was determined for structural SD-OCT alone, en face OCTA alone, and with en face OCTA combined with cross-sectional OCTA. Of 32 eyes with CNV, both graders identified 26 true positives with en face OCTA alone, resulting in a sensitivity of 81.3%. Four of the 6 false negatives had large subretinal hemorrhage (SRH) and sensitivity improved to 94% for both graders if eyes with SRH were excluded. The addition of cross-sectional OCTA along with en face OCTA improved the sensitivity to 100% for both graders. Structural OCT alone also had a sensitivity of 100%. The specificity of en face OCTA alone was 92.5% for grader A and 97.5% for grader B. The specificity of structural OCT alone was 97.5% for grader A and 85% for grader B. Cross-sectional OCTA combined with en face OCTA had a specificity of 97.5% for grader A and 100% for grader B. Sensitivity and specificity for CNV detection with en face OCTA combined with cross-sectional OCTA approaches that of the gold standard of FA with OCT, and it is better than en face OCTA alone. Structural OCT alone has excellent sensitivity for CNV detection. False positives from structural OCT can be mitigated with the addition of flow information with OCTA.

Determinants of total and specific IgE in infants with atopic dermatitis. ETAC Study Group. Early Treatment of the Atopic Child.

PubMed

1997-11-01

ETAC (Early Treatment of the Atopic Child), a multi-centre predominantly European study to investigate the potential for cetirizine to prevent the development of asthma in infants with atopic dermatitis has completed enrollment: 817 children have been randomised to 18 months' treatment with either active or placebo and a subsequent 18 months of post-treatment follow-up. Results of the therapeutic effects will not be available for some time, but the study has provided an opportunity to investigate influences on sensitization to allergens in a large cohort of 1-2 years olds with already established atopic dermatitis, resident in different countries and in different environments. The study shows that in infants with atopic dermatitis, raised serum total IgE has significantly different determinants from that a specific allergen sensitization. In infancy, increased total IgE is more affected by factors increasing risk of intercurrent infection and non-specific airway inflammation, such as environmental tobacco smoke exposure (p < 0.001) and the use of gas cookers (p = 0.02). Specific allergen sensitization as represented by detectable IgE antibodies is influenced primarily by allergen exposure. In Sweden, low level exposure to allergens is associated with reduced specific allergen sensitization rates even though the infants already have atopic dermatitis.

Assessment of medial coronoid disease in 180 canine lame elbow joints: a sensitivity and specificity comparison of radiographic, computed tomographic and arthroscopic findings.

PubMed

Villamonte-Chevalier, A; van Bree, H; Broeckx, Bjg; Dingemanse, W; Soler, M; Van Ryssen, B; Gielen, I

2015-09-25

Diagnostic imaging is essential to assess the lame patient; lesions of the elbow joint have traditionally been evaluated radiographically, however computed tomography (CT) has been suggested as a useful technique to diagnose various elbow pathologies. The primary objective of this study was to determine the sensitivity and specificity of CT to assess medial coronoid disease (MCD), using arthroscopy as gold standard. The secondary objective was to ascertain the radiographic sensitivity and specificity for MCD compared with CT. For this study 180 elbow joints were assessed, of which 141 had been examined with radiography, CT and arthroscopy; and 39 joints, had radiographic and CT assessment. Sensitivity and specificity were calculated for CT and radiographic findings using available statistical software. Sensitivity and specificity of CT using arthroscopy as gold standard resulted in high values for sensitivity (100 %) and specificity (93 %) for the assessment of MCD. For the radiographic evaluation, a sensitivity of 98 % and specificity of 64 - 69 % using CT as the technique of reference, were found. These results suggest that in case of doubt during radiographic assessment, CT could be used as a non-invasive technique to assess the presence of MCD. Based on the high sensitivity and specificity obtained in this study it has been considered that CT, rather than arthroscopy, is the preferred noninvasive technique to assess MCD lesions of the canine elbow joint.

A Retrospective Estimate of Ear Disease Detection Using the "Red Flags" in a Clinical Sample.

PubMed

Klyn, Niall A M; Kleindienst Robler, Samantha; Alfakir, Razan; Nielsen, Donald W; Griffith, James W; Carlson, Deborah L; Lundy, Larry; Dhar, Sumitrajit; Zapala, David A

2018-03-01

The purpose of this study was to evaluate the specificity and sensitivity of two red flag protocols in detecting ear diseases associated with changes in hearing. The presence of red-flag symptoms was determined in a chart review of 307 adult patients from the Mayo Clinic Florida Departments of Otorhinolaryngology and Audiology. Participants formed a convenience sample recruited for a separate study. Neurotologist diagnosis was the criterion for comparisons. Of the 251 patient files retained for analysis, 191 had one or more targeted diseases and 60 had age- or noise-related hearing loss. Food and Drug Administration red flags sensitivity was 91% (confidence interval [CI], 86 to 95%) and specificity was 72% (CI, 59 to 83%). American Academy of Otolaryngology-Head and Neck Surgery red flags sensitivity was 98% (CI, 95 to 99%) and specificity was 20% (CI, 11 to 32%). Stakeholders must determine which diseases are meaningful contraindications for hearing aid use and whether these red-flag protocols have acceptable levels of sensitivity and specificity. As direct-to-consumer models of hearing devices increase, a disease detection method that does not require provider intercession would be useful.

The cut-off values of anthropometric variables for predicting mild cognitive impairment in Malaysian older adults: a large population based cross-sectional study.

PubMed

Won, Huiloo; Abdul, Manaf Zahara; Mat Ludin, Arimi Fitri; Omar, Mohd Azahadi; Razali, Rosdinom; Shahar, Suzana

2017-01-01

Older adults are at risk of mild cognitive impairment (MCI), and simple anthropometric measurements can be used to screen for this condition. Thus, the aim of this study was to explore the cut-off values of body mass index (BMI) and waist circumference (WC) for predicting the risk of MCI in older Malaysian adults. A total of 2,240 Malaysian older adults aged ≥60 years were recruited using multistage random sampling in a population based cross-sectional study. Receiver operating characteristic (ROC) curve was used to determine the cut-off values of BMI and WC with optimum sensitivity and specificity for the detection of MCI. Age, gender, years of education, smoking habit, alcohol consumption, depression, and medical conditions were used as confounding factors in this analysis. A BMI cut-off value of 26 kg/m 2 (area under the receiver operating characteristic curve [AUC] 0.725; sensitivity 90.5%; specificity 38.8%) was appropriate in identifying the risk of getting MCI in both men and women. The optimum WC cut-offs for likelihood of MCI were 90 cm (AUC 0.745; sensitivity 78.0%; specificity 59.8%) for men and 82 cm (AUC 0.714; sensitivity 84.3%; specificity 49.7%) for women. The optimum calf circumference (CC) cut-off values for identifying MCI were 29 cm (AUC 0.731; sensitivity 72.6%; specificity 61.1%) for men and 26 cm (AUC 0.598; sensitivity 79.1%; specificity 45.3%) for women. The cut-off values could be advocated and used as part of the screening of MCI among older Malaysian adults. There is a need to further determine the predictive values of these cut-off points on outcomes through longitudinal study design.

Moderate sensitivity and high specificity of emergency department administrative data for transient ischemic attacks.

PubMed

Yu, Amy Y X; Quan, Hude; McRae, Andrew; Wagner, Gabrielle O; Hill, Michael D; Coutts, Shelagh B

2017-09-18

Validation of administrative data case definitions is key for accurate passive surveillance of disease. Transient ischemic attack (TIA) is a condition primarily managed in the emergency department. However, prior validation studies have focused on data after inpatient hospitalization. We aimed to determine the validity of the Canadian 10th International Classification of Diseases (ICD-10-CA) codes for TIA in the national ambulatory administrative database. We performed a diagnostic accuracy study of four ICD-10-CA case definition algorithms for TIA in the emergency department setting. The study population was obtained from two ongoing studies on the diagnosis of TIA and minor stroke versus stroke mimic using serum biomarkers and neuroimaging. Two reference standards were used 1) the emergency department clinical diagnosis determined by chart abstractors and 2) the 90-day final diagnosis, both obtained by stroke neurologists, to calculate the sensitivity, specificity, positive and negative predictive values (PPV and NPV) of the ICD-10-CA algorithms for TIA. Among 417 patients, emergency department adjudication showed 163 (39.1%) TIA, 155 (37.2%) ischemic strokes, and 99 (23.7%) stroke mimics. The most restrictive algorithm, defined as a TIA code in the main position had the lowest sensitivity (36.8%), but highest specificity (92.5%) and PPV (76.0%). The most inclusive algorithm, defined as a TIA code in any position with and without query prefix had the highest sensitivity (63.8%), but lowest specificity (81.5%) and PPV (68.9%). Sensitivity, specificity, PPV, and NPV were overall lower when using the 90-day diagnosis as reference standard. Emergency department administrative data reflect diagnosis of suspected TIA with high specificity, but underestimate the burden of disease. Future studies are necessary to understand the reasons for the low to moderate sensitivity.

Determination of the optimal case definition for the diagnosis of end-stage renal disease from administrative claims data in Manitoba, Canada.

PubMed

Komenda, Paul; Yu, Nancy; Leung, Stella; Bernstein, Keevin; Blanchard, James; Sood, Manish; Rigatto, Claudio; Tangri, Navdeep

2015-01-01

End-stage renal disease (ESRD) is a major public health problem with increasing prevalence and costs. An understanding of the long-term trends in dialysis rates and outcomes can help inform health policy. We determined the optimal case definition for the diagnosis of ESRD using administrative claims data in the province of Manitoba over a 7-year period. We determined the sensitivity, specificity, predictive value and overall accuracy of 4 administrative case definitions for the diagnosis of ESRD requiring chronic dialysis over different time horizons from Jan. 1, 2004, to Mar. 31, 2011. The Manitoba Renal Program Database served as the gold standard for confirming dialysis status. During the study period, 2562 patients were registered as recipients of chronic dialysis in the Manitoba Renal Program Database. Over a 1-year period (2010), the optimal case definition was any 2 claims for outpatient dialysis, and it was 74.6% sensitive (95% confidence interval [CI] 72.3%-76.9%) and 94.4% specific (95% CI 93.6%-95.2%) for the diagnosis of ESRD. In contrast, a case definition of at least 2 claims for dialysis treatment more than 90 days apart was 64.8% sensitive (95% CI 62.2%-67.3%) and 97.1% specific (95% CI 96.5%-97.7%). Extending the period to 5 years greatly improved sensitivity for all case definitions, with minimal change to specificity; for example, for the optimal case definition of any 2 claims for dialysis treatment, sensitivity increased to 86.0% (95% CI 84.7%-87.4%) at 5 years. Accurate case definitions for the diagnosis of ESRD requiring dialysis can be derived from administrative claims data. The optimal definition required any 2 claims for outpatient dialysis. Extending the claims period to 5 years greatly improved sensitivity with minimal effects on specificity for all case definitions.

The Sensitivity of Adolescent Hearing Screens Significantly Improves by Adding High Frequencies.

PubMed

Sekhar, Deepa L; Zalewski, Thomas R; Beiler, Jessica S; Czarnecki, Beth; Barr, Ashley L; King, Tonya S; Paul, Ian M

2016-09-01

One in 6 US adolescents has high-frequency hearing loss, often related to hazardous noise. Yet, the American Academy of Pediatrics (AAP) hearing screen (500, 1,000, 2,000, 4,000 Hertz) primarily includes low frequencies (<3,000 Hertz). Study objectives were to determine (1) sensitivity and specificity of the AAP hearing screen for adolescent hearing loss and (2) if adding high frequencies increases sensitivity, while repeat screening of initial referrals reduces false positive results (maintaining acceptable specificity). Eleventh graders (n = 134) participated in hearing screening (2013-2014) including "gold-standard" sound-treated booth testing to calculate sensitivity and specificity. Of the 43 referrals, 27 (63%) had high-frequency hearing loss. AAP screen sensitivity and specificity were 58.1% (95% confidence interval 42.1%-73.0%) and 91.2% (95% confidence interval 83.4-96.1), respectively. Adding high frequencies (6,000, 8,000 Hertz) significantly increased sensitivity to 79.1% (64.0%-90.0%; p = .003). Specificity with repeat screening was 81.3% (71.8%-88.7%; p = .003). Adolescent hearing screen sensitivity improves with high frequencies. Repeat testing maintains acceptable specificity. Copyright © 2016 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Prevalence of sensitization to 'improver' enzymes in UK supermarket bakers.

PubMed

Jones, M; Welch, J; Turvey, J; Cannon, J; Clark, P; Szram, J; Cullinan, P

2016-07-01

Supermarket bakers are exposed not only to flour and alpha-amylase but also to other 'improver' enzymes, the nature of which is usually shrouded by commercial sensitivity. We aimed to determine the prevalence of sensitization to 'improver' enzymes in UK supermarket bakers. We examined the prevalence of sensitization to enzymes in 300 bakers, employed by one of two large supermarket bakeries, who had declared work-related respiratory symptoms during routine health surveillance. Sensitization was determined using radioallergosorbent assay to eight individual enzymes contained in the specific 'improver' mix used by each supermarket. The prevalence of sensitization to 'improver' enzymes ranged from 5% to 15%. Sensitization was far more likely if the baker was sensitized also to either flour or alpha-amylase. The prevalence of sensitization to an 'improver' enzyme did not appear to be related to the concentration of that enzyme in the mix. We report substantial rates of sensitization to enzymes other than alpha-amylase in UK supermarket bakers; in only a small proportion of bakers was there evidence of sensitization to 'improver mix' enzymes without sensitization to either alpha-amylase or flour. The clinical significance of these findings needs further investigation, but our findings indicate that specific sensitization in symptomatic bakers may not be identified without consideration of a wide range of workplace antigens. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Detection of LipL32-specific IgM by ELISA in sera of patients with a clinical diagnosis of leptospirosis

PubMed Central

Vedhagiri, Kumaresan; Velineni, Sridhar; Timoney, John F; Shanmughapriya, Santhanam; Vijayachari, Paluru; Narayanan, Ramasamy; Natarajaseenivasan, Kalimuthusamy

2013-01-01

Successful treatment of leptospirosis is heavily dependent on early diagnosis and prompt initiation of antibiotic therapy. An ELISA test to detect specific IgM antibodies against LipL32 for early diagnosis of leptospirosis is described and evaluated here. One thousand one hundred and eighty sera from clinically suspected leptospirosis cases were enrolled together with 109 healthy volunteers selected from an endemic area between October 2007 and January 2010. Patients were categorized based on their clinical signs and symptoms. Sera were screened for leptospiral antibodies by the microscopic agglutination test (MAT) using a panel of locally circulating serovars followed by enzyme-linked immunosorbent assay (ELISA) based on recombinant LipL32 from Leptospira interrogans serovar Autumnalis strain N2. The sensitivity and specificity of the ELISA test were determined to establish its diagnostic efficiency. The cut-off value was determined to be 0.205. Overall sensitivity and specificity compared to the MAT were found to be 96.4 and 90.4%, respectively. The LipL32-specific IgM ELISA had good sensitivity and acceptable specificity and may be a candidate for the early serodiagnosis of human leptospirosis. PMID:23683367

Molecular allergy diagnostics using IgE singleplex determinations: methodological and practical considerations for use in clinical routine: Part 18 of the Series Molecular Allergology.

PubMed

Kleine-Tebbe, Jörg; Jakob, Thilo

Allergen molecules (synonyms: single allergens, allergen components) open up new horizons for the targeted allergen-specific diagnostics of immunoglobulin E (IgE) in singleplex determination. The following rationales support the targeted use of allergen molecules and, more importantly, improve test properties: (1) increased test sensitivity ("analytical sensitivity"), particularly when important allergens are under-represented or lacking in the extract; (2) improved test selectivity (analytical specificity), particularly when the selected IgE repertoire against an allergen yields additional information on: (a) potential risk, (b) possible cross-reactivity, or (c) primary (species-specific) sensitization. However, the appropriate indication for the use of single allergens can only be established on a case-by-case basis (depending on the clinical context and previous history) and in an allergen-specific manner (depending on the allergen source and the single allergens available), rather than in a standardized way. Numerous investigations on suspected food allergy, insect venom allergy, or sensitization to respiratory allergens have meanwhile demonstrated the successful use of defined molecules for allergen-specific singleplex IgE diagnosis. Specific IgE to single allergens is limited in its suitability to predict the clinical relevance of sensitivity on an individual basis. In food allergies, one can at best identify the relative risk of a clinical reaction on the basis of an IgE profile, but no absolutely reliable prediction on (future) tolerance can be made. Ultimately, the clinical relevance of all IgE findings depends on the presence of corresponding symptoms and can only be assessed on an individual basis (previous history, symptom log, and provocation testing with the relevant allergen source where appropriate). Thus, also in molecular allergology, the treating physician and not the test result should determine the clinical relevance of diagnostic findings. Supplementary material is available for this article at 10.1007/s40629-015-0067-z and is accessible for authorized users.

Estimating sensitivity and specificity for technology assessment based on observer studies.

PubMed

Nishikawa, Robert M; Pesce, Lorenzo L

2013-07-01

The goal of this study was to determine the accuracy and precision of using scores from a receiver operating characteristic rating scale to estimate sensitivity and specificity. We used data collected in a previous study that measured the improvements in radiologists' ability to classify mammographic microcalcification clusters as benign or malignant with and without the use of a computer-aided diagnosis scheme. Sensitivity and specificity were estimated from the rating data from a question that directly asked the radiologists their biopsy recommendations, which was used as the "truth," because it is the actual recall decision, thus it is their subjective truth. By thresholding the rating data, sensitivity and specificity were estimated for different threshold values. Because of interreader and intrareader variability, estimated sensitivity and specificity values for individual readers could be as much as 100% in error when using rating data compared to using the biopsy recommendation data. When pooled together, the estimates using thresholding the rating data were in good agreement with sensitivity and specificity estimated from the recommendation data. However, the statistical power of the rating data estimates was lower. By simply asking the observer his or her explicit recommendation (eg, biopsy or no biopsy), sensitivity and specificity can be measured directly, giving a more accurate description of empirical variability and the power of the study can be maximized. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

Antibody against mutated citrullinated vimentin: a new sensitive marker in the diagnosis of rheumatoid arthritis.

PubMed

Wagner, Ernst; Skoumal, M; Bayer, P M; Klaushofer, K

2009-09-01

The aim of this study was to determine the performance of antibodies against mutated citrullinated vimentin (anti-MCV) in comparison with antibodies to cyclic citrullinated peptides (anti-CCP) in patients with rheumatoid arthritis (RA). Serum levels of anti-MCV and anti-CCP were determined in 193 patients with RA and 332 controls, and sensitivity and specificity were calculated. In a separate analysis of 86 patients, the anti-MCV levels were compared to disease activity. Sensitivity of anti-MCV versus anti-CCP was 71.5 and 69.4%, specificity was 81.3 and 97.6%, respectively. The ROC curves showed higher specificity and an advantage of anti-CCP. In seronegative RA patients the sensitivity of anti-MCV was superior over anti-CCP. Anti-MCV positivities also occurred in systemic lupus erythematosus and Sjoegren's syndrome. In a subgroup of 86 RA patients we found a significant correlation between anti-MCV and disease activity. Anti-MCV appears to be an important marker for the diagnosis of RA, and correlates also with disease activity.

Comparison of five diagnostic tests for Giardia duodenalis in fecal samples from young dogs.

PubMed

Uehlinger, Fabienne D; Naqvi, S Ali; Greenwood, Spencer J; McClure, J Trenton; Conboy, Gary; O'Handley, Ryan; Barkema, Herman W

2017-09-15

Five diagnostic tests were compared for the diagnosis of Giardia duodenalis in fecal samples of young dogs. Fecal samples were collected from 136 healthy dogs <1year old and examined using immunofluorescence antibody microscopy (IFA) after sucrose gradient centrifugation, zinc sulfate centrifugal flotation technique (ZSCT), SNAP ® Giardia test, and ProSpecT ® Giardia EZ Microplate assay. In addition, polymerase chain reaction (PCR) of the 16S rRNA gene was performed. Kappa (κ) statistic was calculated to assess diagnostic agreement between the IFA and each test. Using the IFA as the gold standard, the relative sensitivity and specificity of each test were determined. Subsequently, a Bayesian approach was used to estimate the sensitivity and specificity of each test in comparison to the IFA results. Giardia duodenalis was detected in 41% of the samples examined by IFA. The ZSCT resulted in 37% of positive samples, with a relative sensitivity and specificity of 86 and 98%, respectively. The SNAP ® Giardia test was positive in 40% of the samples, with a relative sensitivity and specificity of 91 and 96%, respectively. The ProSpecT ® test was positive in 51% of the samples, with a relative sensitivity and specificity of 100 and 83%, respectively. The relative sensitivity and specificity for PCR were 58 and 56%, respectively, with 55% of samples being PCR-positive. While the sensitivity and specificity estimates of each test in comparison to the IFA changed when using a Bayesian approach, the conclusions remained the same. While the ProSpecT ® test was the most sensitive test in this study, it is not designed for dogs and more costly than the other tests. The SNAP ® Giardia test performed similar to the ZSCT but may be more favorable because it is fast and easy to perform. Performance of the PCR was poor and the benefit of PCR may be in determining genotypes for evaluating zoonotic transfer between dogs and humans. Copyright © 2017 Elsevier B.V. All rights reserved.

Systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for osteoporosis or low bone density

PubMed Central

Edwards, D. L.; Saleh, A. A.; Greenspan, S. L.

2015-01-01

Summary We performed a systematic review and meta-analysis of the performance of clinical risk assessment instruments for screening for DXA-determined osteoporosis or low bone density. Commonly evaluated risk instruments showed high sensitivity approaching or exceeding 90 % at particular thresholds within various populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments. Introduction The purpose of the study is to systematically review the performance of clinical risk assessment instruments for screening for dual-energy X-ray absorptiometry (DXA)-determined osteoporosis or low bone density. Methods Systematic review and meta-analysis were performed. Multiple literature sources were searched, and data extracted and analyzed from included references. Results One hundred eight references met inclusion criteria. Studies assessed many instruments in 34 countries, most commonly the Osteoporosis Self-Assessment Tool (OST), the Simple Calculated Osteoporosis Risk Estimation (SCORE) instrument, the Osteoporosis Self-Assessment Tool for Asians (OSTA), the Osteoporosis Risk Assessment Instrument (ORAI), and body weight criteria. Meta-analyses of studies evaluating OST using a cutoff threshold of <1 to identify US postmenopausal women with osteoporosis at the femoral neck provided summary sensitivity and specificity estimates of 89 % (95%CI 82–96 %) and 41 % (95%CI 23–59 %), respectively. Meta-analyses of studies evaluating OST using a cutoff threshold of 3 to identify US men with osteoporosis at the femoral neck, total hip, or lumbar spine provided summary sensitivity and specificity estimates of 88 % (95%CI 79–97 %) and 55 % (95%CI 42–68 %), respectively. Frequently evaluated instruments each had thresholds and populations for which sensitivity for osteoporosis or low bone mass detection approached or exceeded 90 % but always with a trade-off of relatively low specificity. Conclusions Commonly evaluated clinical risk assessment instruments each showed high sensitivity approaching or exceeding 90 % for identifying individuals with DXA-determined osteoporosis or low BMD at certain thresholds in different populations but low specificity at thresholds required for high sensitivity. Simpler instruments, such as OST, generally performed as well as or better than more complex instruments. PMID:25644147

Comparison of loop-mediated isothermal amplification assay and smear microscopy with culture for the diagnostic accuracy of tuberculosis.

PubMed

Gelaw, Baye; Shiferaw, Yitayal; Alemayehu, Marta; Bashaw, Abate Assefa

2017-01-17

Tuberculosis (TB) caused by Mycobacterium tuberculosis is one of the leading causes of death from infectious diseases worldwide. Sputum smear microscopy remains the most widely available pulmonary TB diagnostic tool particularly in resource limited settings. A highly sensitive diagnostic with minimal infrastructure, cost and training is required. Hence, we assessed the diagnostic performance of Loop-mediated isothermal amplification (LAMP) assay in detecting M.tuberculosis infection in sputum sample compared to LED fluorescent smear microscopy and culture. A cross-sectional study was conducted at the University of Gondar Hospital from June 01, 2015 to August 30, 2015. Pulmonary TB diagnosis using sputum LED fluorescence smear microscopy, TB-LAMP assay and culture were done. A descriptive analysis was used to determine demographic characteristics of the study participants. Analysis of sensitivity and specificity for smear microscopy and TB-LAMP compared with culture as a reference test was performed. Cohen's kappa was calculated as a measure of agreement between the tests. A total of 78 pulmonary presumptive TB patients sputum sample were analyzed. The overall sensitivity and specificity of LAMP were 75 and 98%, respectively. Among smear negative sputum samples, 33.3% sensitivity and 100% specificity of LAMP were observed. Smear microscopy showed 78.6% sensitivity and 98% specificity. LAMP and smear in series had sensitivity of 67.8% and specificity of 100%. LAMP and smear in parallel had sensitivity of 85.7% and specificity of 96%. The agreement between LAMP and fluorescent smear microscopy tests was very good (κ = 0.83, P-value ≤0.0001). TB-LAMP showed similar specificity but a slightly lower sensitivity with LED fluorescence microscopy. The specificity of LAMP and smear microscopy in series was high. The sensitivity of LAMP was insufficient for smear negative sputum samples.

Determinants of Cervical Cancer Screening Accuracy for Visual Inspection with Acetic Acid (VIA) and Lugol’s Iodine (VILI) Performed by Nurse and Physician

PubMed Central

Raifu, Amidu O.; El-Zein, Mariam; Sangwa-Lugoma, Ghislain; Ramanakumar, Agnihotram; Walter, Stephen D.

2017-01-01

Background Visual inspection with acetic acid (VIA) and Lugol’s iodine (VILI) are used to screen women for cervical cancer in low-resource settings. Little is known about correlates of their diagnostic accuracy by healthcare provider. We examined determinants of VIA and VILI screening accuracy by examiner in a cross-sectional screening study of 1528 women aged 30 years or older in a suburb of Kinshasa, Democratic Republic of Congo. Methods We used a logistic regression model for sensitivity and specificity to estimate the diagnostic accuracy of VIA and VILI, independently performed by nurse and physician, as a function of sociodemographic and reproductive health characteristics. Results Nurses rated tests as positive more often than physicians (36.3% vs 30.2% for VIA, 26.2% vs 25.2% for VILI). Women’s age was the most important determinant of performance. It was inversely associated with sensitivity (nurse’s VIA: p<0.001, nurse’s VILI: p = 0.018, physician’s VIA: p = 0.005, physician’s VILI: p = 0.006) but positively associated with specificity (all four combinations: p<0.001). Increasing parity adversely affected sensitivity and specificity, but the effects on sensitivity were significant for nurses only. The screening performance of physician’s assessment was significantly better than the nurse’s (difference in sensitivity: VIA = 13%, VILI = 16%; difference in specificity: VIA = 6%, VILI = 1%). Conclusions Age and parity influence the performance of visual tests for cervical cancer screening. Proper training of local healthcare providers in the conduct of these tests should take into account these factors for improved performance of VIA and VILI in detecting cervical precancerous lesions among women in limited-resource settings. PMID:28107486

Comparison of accuracy of pregnancy-associated glycoprotein (PAG) concentration in blood and milk for early pregnancy diagnosis in cows.

PubMed

Gajewski, Z; Petrajtis-Gołobów, M; Melo de Sousa, N; Beckers, J F; Pawliński, B; Wehrend, A

2014-12-01

The aim of this study was to compare two methods of early pregnancy diagnosis by determining pregnancy-associated glycoprotein (PAG) concentration in blood and PAG concentration in milk. Blood and milk samples were obtained on days 0 (AI day), 14, 21, 28, 35, 49, 63, 77, 91 and 105 of gestation from 60 lactating Holstein Frisian cows from one herd, carrying live fetuses. To determine PAG concentration a specific RIA system (RIA-706) was used. PAG concentration in blood and milk increased after 28 days of pregnancy, with blood concentrations being significantly higher than in milk. However, the accuracy of both tests at this time point was similar (sensitivity: 92 % in blood, 93 % in milk; specificity 53 % and 60 % respectively). None of the tests were able to detect open cows properly at this stage. On day 35 of gestation sensitivity (100 % for blood, 97 % for milk) and specificity (100 % for blood, 100 % for milk) were high enough to be used for reliable pregnancy diagnosis. The accuracy (sensitivity and specificity) for PAG concentrations in blood and milk for the rest of the study was 100 %. Our investigation shows that PAG determination in milk is a stress-free and non-invasive method for early pregnancy diagnosis in cattle.

Criteria To Screen for Chronic Sinonasal Disease

PubMed Central

Dixon, Anne E.; Sugar, Elizabeth A.; Zinreich, S. James; Slavin, Raymond G.; Corren, Jonathan; Naclerio, Robert M.; Ishii, Masaru; Cohen, Rubin I.; Brown, Ellen D.; Wise, Robert A.; Irvin, Charles G.

2009-01-01

Background: Sinusitis and rhinitis are associated with uncontrolled asthma. There are no simple, validated tools to screen for these diseases. The objective of this study was to assess instruments to assist in the diagnosis of chronic sinonasal disease. Methods: Participants without acute sinonasal symptoms underwent an extensive evaluation. The results were submitted to an expert panel that used the Delphi method to achieve consensus. Using the consensus diagnosis of the panel, we determined the sensitivity and specificity of test procedures to diagnose chronic sinonasal disease. We determined the reproducibility of the most sensitive and specific instrument in a separate cohort. Results: Fifty-nine participants were evaluated, and the expert panel reached consensus for all (42 participants with chronic sinonasal disease, 17 participants without chronic sinonasal disease). A six-item questionnaire based on the frequency of nasal symptoms was the most sensitive tool used to diagnose sinonasal disease (minimum specificity, 0.90). Reproducibility testing in a separate cohort of 63 participants (41 chronic sinonasal disease with asthma, 22 chronic sinonasal disease without asthma) showed a concordance correlation coefficient of 0.91 (95% CI, 0.85 to 0.94) when this questionnaire was limited to five items (ie, excluding a question on smell). This five-item questionnaire had a sensitivity of 0.90 (95% CI, 0.77 to 0.97), a specificity of 0.94 (95% CI, 0.71 to 1.00), and an area under the receiver operating characteristic curve of 0.97 (95% CI, 0.93 to 1.0). Sinus CT scans and nasal endoscopy lacked sensitivity for use in the diagnosis of chronic sinonasal disease. Conclusions: We have developed a sensitive, specific, and reproducible instrument to screen for chronic sinonasal disease. Validation studies of this five-item questionnaire are needed, including in patients with asthma. PMID:19581356

The Sensitivity and Specificity of Potassium Hydroxide Smear and Fungal Culture Relative to Clinical Assessment in the Evaluation of Tinea Pedis: A Pooled Analysis

PubMed Central

Levitt, Jacob Oren; Levitt, Barrie H.; Akhavan, Arash; Yanofsky, Howard

2010-01-01

Background. There are relatively few studies published examining the sensitivity and specificity of potassium hydroxide (KOH) smear and fungal culture examination of tinea pedis. Objective. To evaluate the sensitivity and specificity of KOH smear and fungal culture for diagnosing tinea pedis. Methods. A pooled analysis of data from five similarly conducted bioequivalence trials for antifungal drugs was performed. Data from 460 patients enrolled in the vehicle arms of these studies with clinical diagnosis of tinea pedis supported by positive fungal culture were analyzed 6 weeks after initiation of the study to determine the sensitivity and specificity of KOH smear and fungal culture. Results. Using clinical assessment as the gold standard, the sensitivities for KOH smear and culture were 73.3% (95% CI: 66.3 to 79.5%) and 41.7% (34.6 to 49.1%), respectively. The respective specificities for culture and KOH smear were 77.7% (72.2 to 82.5%) and 42.5% (36.6 to 48.6%). Conclusion. KOH smear and fungal culture are complementary diagnostic tests for tinea pedis, with the former being the more sensitive test of the two, and the latter being more specific. PMID:20672004

Refractometer assessment of colostral and serum IgG and milk total solids concentrations in dairy cattle

PubMed Central

2014-01-01

Background Estimation of the quantity of colostral IgG or serum IgG absorbed following ingestion of colostrum by calves is essential for monitoring the effectiveness of colostrum feeding practices on dairy farms. Milk total solids concentrations determination is a critical part of quality assessment of nonsaleable whole milk prior to feeding to calves. To date, on-farm methods to assess colostral IgG, serum IgG or milk total solids concentrations have been performed separately with various instruments. The objective of this study was to evaluate the diagnostic performance of a single electronic, hand-held refractometer for assessing colostral and serum IgG concentrations and milk total solids in dairy cattle. Colostral IgG, serum IgG and milk total solids concentrations were determined by the refractometer. Corresponding analysis of colostral and serum IgG concentrations were determined by radial immunodiffusion (RID) while milk total solids were determined by spectrophotometry. Sensitivity and specificity of the refractometer for colostrum and serum samples were calculated as determined by RID. Sensitivity and specificity of the refractometer for milk samples was calculated as determined by spectrophotometry. Results The sensitivity of the refractometer was 1 for colostral IgG, serum IgG and milk total solids determinations. Specificity of the refractometer was 0.66, 0.24 and 0 for colostral IgG, serum IgG and milk total solids determinations, respectively. The refractometer underestimated colostral IgG, serum IgG and milk total solids concentrations compared to the concentrations determined by RID or spectrophotometry. Conclusions The refractometer was an acceptable, rapid, convenient on-farm method for determining colostral IgG and milk total solids. The refractometer was not an acceptable method for determination of serum IgG concentrations as it severely underestimated the serum IgG concentrations. PMID:25125217

A Nanoporous Alumina Membrane Based Electrochemical Biosensor for Histamine Determination with Biofunctionalized Magnetic Nanoparticles Concentration and Signal Amplification

PubMed Central

Ye, Weiwei; Xu, Yifan; Zheng, Lihao; Zhang, Yu; Yang, Mo; Sun, Peilong

2016-01-01

Histamine is an indicator of food quality and indispensable in the efficient functioning of various physiological systems. Rapid and sensitive determination of histamine is urgently needed in food analysis and clinical diagnostics. Traditional histamine detection methods require qualified personnel, need complex operation processes, and are time-consuming. In this study, a biofunctionalized nanoporous alumina membrane based electrochemical biosensor with magnetic nanoparticles (MNPs) concentration and signal amplification was developed for histamine determination. Nanoporous alumina membranes were modified by anti-histamine antibody and integrated into polydimethylsiloxane (PDMS) chambers. The specific antibody modified MNPs were used to concentrate histamine from samples and transferred to the antibody modified nanoporous membrane. The MNPs conjugated to histamine were captured in the nanopores via specific reaction between histamine and anti-histamine antibody, resulting in a blocking effect that was amplified by MNPs in the nanopores. The blockage signals could be measured by electrochemical impedance spectroscopy across the nanoporous alumina membrane. The sensing platform had great sensitivity and the limit of detection (LOD) reached as low as 3 nM. This biosensor could be successfully applied for histamine determination in saury that was stored in frozen conditions for different hours, presenting a potentially novel, sensitive, and specific sensing system for food quality assessment and safety support. PMID:27782087

Evaluation of Leishmania species reactivity in human serologic diagnosis of leishmaniasis.

PubMed

Silvestre, Ricardo; Santarém, Nuno; Teixeira, Lúcia; Cunha, Joana; Schallig, Henk; Cordeiro-da-Silva, Anabela

2009-08-01

The sensitivities and specificities of IgG-ELISA and IgG flow cytometry based techniques using different Leishmania species were determined using sera collected from 40 cutaneous or visceral leishmaniasis patients. The flow cytometry technique, using promastigote parasite forms, performed better than total soluble extract IgG-ELISA. At the species level, the use of Leishmania amazonensis and Leishmania major as antigens in enzyme linked immunosorbent assay (ELISA) decreased the overall sensitivity. To assess the specificity of these tests, sera from malaria, toxoplasmosis, amoebiasis, schistosomiasis, and leprosy patients were used. We also included sera from Leishmania non-infected endemic individuals. The cutaneous species displayed a decreased specificity in both assays. Although more sensitive, flow cytometry using promastigote parasite forms generally presented lower levels of specificity when compared with total extract of IgG-ELISA. Overall, the results of the study show the potential of IgG flow cytometry for the diagnosis of leishmaniasis. Although highly sensitive, a refinement of the flow cytometry method should be performed to improve the overall specificity.

ERBB-Receptors and Drug Response in Breast Cancer

DTIC Science & Technology

1997-09-01

in topoisomerase II a (topo II a ) levels seen may be understood by global changes in DNA repair enzymes, brought about by signaling through the EGFR...ErbB-mediated signaling and topoisomerase II a levels specifically as they relate to drug sensitivity/resistance. This information will allow the use...topoisomerase II a levels and increased sensitivity to doxorubicin. In order to determine which, if any, of the specific receptors involved are

Cardiothoracic ratio for prediction of left ventricular dilation: a systematic review and pooled analysis.

PubMed

Loomba, Rohit S; Shah, Parinda H; Nijhawan, Karan; Aggarwal, Saurabh; Arora, Rohit

2015-03-01

Increased cardiothoracic ratio noted on chest radiographs often prompts concern and further evaluation with additional imaging. This study pools available data assessing the utility of cardiothoracic ratio in predicting left ventricular dilation. A systematic review of the literature was conducted to identify studies comparing cardiothoracic ratio by chest x-ray to left ventricular dilation by echocardiography. Electronic databases were used to identify studies which were then assessed for quality and bias, with those with adequate quality and minimal bias ultimately being included in the pooled analysis. The pooled data were used to determine the sensitivity, specificity, positive predictive value and negative predictive value of cardiomegaly in predicting left ventricular dilation. A total of six studies consisting of 466 patients were included in this analysis. Cardiothoracic ratio had 83.3% sensitivity, 45.4% specificity, 43.5% positive predictive value and 82.7% negative predictive value. When a secondary analysis was conducted with a pediatric study excluded, a total of five studies consisting of 371 patients were included. Cardiothoracic ratio had 86.2% sensitivity, 25.2% specificity, 42.5% positive predictive value and 74.0% negative predictive value. Cardiothoracic ratio as determined by chest radiograph is sensitive but not specific for identifying left ventricular dilation. Cardiothoracic ratio also has a strong negative predictive value for identifying left ventricular dilation.

Sensitivity and specificity of the body mass index for the diagnosis of overweight/obesity in elderly.

PubMed

Vasconcelos, Francisco de Assis Guedes de; Cordeiro, Braian Alves; Rech, Cassiano Ricardo; Petroski, Edio Luiz

2010-08-01

The aim of this article was to verify the sensitivity and specificity of the body mass index (BMI) cut-off points proposed by the World Health Organization (WHO) and the Nutrition Screening Initiative (NSI) for the diagnosis of obesity in the elderly. A cross-sectional study was made with 180 healthy elderly subjects from Florianópolis, Santa Catarina State, Brazil. Body fat percentage (%BF) was determined using DEXA (dual energy X-ray absorptiometry). The BMI cut-off point of the NSI offers better sensitivity and specificity for men (73.7% and 72.5% respectively). For women, the lower the cut-off point the better the sensitivity, with a BMI of 25kg/m² (sensitivity of 76.3% and specificity of 100%) being the most accurate for diagnosing obesity in elderly women. The WHO cut-off point offered very low sensitivity (28.9%). The results of this investigation lead to the conclusion that the cut-off points proposed by the WHO and the ones adopted by the NSI and by Lipschitz are not good indicators of obesity for the elderly of either sex, since they offer low sensitivity.

Determination of Caffeine in Beverages by Capillary Zone Electrophoresis: An Experiment for the Undergraduate Analytical Laboratory

NASA Astrophysics Data System (ADS)

Conte, Eric D.; Barry, Eugene F.; Rubinstein, Harry

1996-12-01

Certain individuals may be sensitive to specific compounds in comsumer products. It is important to quantify these analytes in food products in order to monitor their intake. Caffeine is one such compound. Determination of caffeine in beverages by spectrophotometric procedures requires an extraction procedure, which can prove time-consuming. Although the corresponding determination by HPLC allows for a direct injection, capillary zone electrophoresis provides several advantages such as extremely low solvent consumption, smaller sample volume requirements, and improved sensitivity.

Sensitivity and specificity of the Percentage of Consonants Correct-Revised in the identification of speech sound disorder.

PubMed

Barrozo, Tatiane Faria; Pagan-Neves, Luciana de Oliveira; Pinheiro da Silva, Joyce; Wertzner, Haydée Fiszbein

2017-05-22

The purpose of the study was to determine the sensitivity and specificity, and to establish cutoff points for the severity index Percentage of Consonants Correct - Revised (PCC-R) in Brazilian Portuguese-speaking children with and without speech sound disorders. 72 children between 5:00 and 7:11 years old - 36 children without speech and language complaints and 36 children with speech sound disorders. The PCC-R was applied to the figure naming and word imitation tasks that are part of the ABFW Child Language Test. Results were statistically analyzed. The ROC curve was performed and sensitivity and specificity values ​​of the index were verified. The group of children without speech sound disorders presented greater PCC-R values in both tasks, regardless of the gender of the participants. The cutoff value observed for the picture naming task was 93.4%, with a sensitivity value of 0.89 and specificity of 0.94 (age independent). For the word imitation task, results were age-dependent: for age group ≤6:5 years old, the cutoff value was 91.0% (sensitivity of 0.77 and specificity of 0.94) and for age group >6:5 years-old, the cutoff value was 93.9% (sensitivity of 0.93 and specificity of 0.94). Given the high sensitivity and specificity of PCC-R, we can conclude that the index was effective in discriminating and identifying children with and without speech sound disorders.

[Validation of the abbreviated Zarit scales for measuring burden syndrome in the primary caregiver of an elderly patient].

PubMed

Vélez Lopera, Johana María; Berbesí Fernández, Dedsy; Cardona Arango, Doris; Segura Cardona, Angela; Ordóñez Molina, Jaime

2012-07-01

To determine which abbreviated Zarit Scale (ZS) better evaluates the burden of the caregiver of an elderly patient in Medellin, Colombia. Validation study. Primary Care setting in the city of Medellin. Primary caregiver of dependent elderly patients over 65 years old. Sensitivity, specificity, positive predictive value, and negative predictive value for the different abbreviated Zarit scales, plus performing a reliability analysis using the Cronbach Alpha coefficient. The abbreviated scales obtained a sensitivity of between 36.84 and 81.58%, specificity between 95.99 and 100%, positive predictive values between 71.05 and 100%, and negative predictive values of between 91.64 and 97.42%. The scale that better determined caregiver burden in Primary Care was the Bedard Screening scale, with a sensitivity of 81.58%, a specificity of 96.35% and positive and negative predictive values of 75.61% and 97.42%, respectively. Copyright © 2010 Elsevier España, S.L. All rights reserved.

Analysis of world terror networks from the reduced Google matrix of Wikipedia

NASA Astrophysics Data System (ADS)

El Zant, Samer; Frahm, Klaus M.; Jaffrès-Runser, Katia; Shepelyansky, Dima L.

2018-01-01

We apply the reduced Google matrix method to analyze interactions between 95 terrorist groups and determine their relationships and influence on 64 world countries. This is done on the basis of the Google matrix of the English Wikipedia (2017) composed of 5 416 537 articles which accumulate a great part of global human knowledge. The reduced Google matrix takes into account the direct and hidden links between a selection of 159 nodes (articles) appearing due to all paths of a random surfer moving over the whole network. As a result we obtain the network structure of terrorist groups and their relations with selected countries including hidden indirect links. Using the sensitivity of PageRank to a weight variation of specific links we determine the geopolitical sensitivity and influence of specific terrorist groups on world countries. The world maps of the sensitivity of various countries to influence of specific terrorist groups are obtained. We argue that this approach can find useful application for more extensive and detailed data bases analysis.

The diagnostic adaptive behavior scale: evaluating its diagnostic sensitivity and specificity.

PubMed

Balboni, Giulia; Tassé, Marc J; Schalock, Robert L; Borthwick-Duffy, Sharon A; Spreat, Scott; Thissen, David; Widaman, Keith F; Zhang, Dalun; Navas, Patricia

2014-11-01

The Diagnostic Adaptive Behavior Scale (DABS) was constructed with items across three domains--conceptual, social, and practical adaptive skills--and normed on a representative sample of American individuals from 4 to 21 years of age. The DABS was developed to focus its assessment around the decision point for determining the presence or absence of significant limitations of adaptive behavior for the diagnosis of Intellectual Disability (ID). The purpose of this study, which was composed of 125 individuals with and 933 without an ID-related diagnosis, was to determine the ability of the DABS to correctly identify the individuals with and without ID (i.e., sensitivity and specificity). The results indicate that the DABS sensitivity coefficients ranged from 81% to 98%, specificity coefficients ranged from 89% to 91%, and that the Area Under the Receiver Operating Characteristic Curve were excellent or good. These results indicate that the DABS has very good levels of diagnostic efficiency. Copyright © 2014. Published by Elsevier Ltd.

[Detection of rubella virus RNA in clinical material by real time polymerase chain reaction method].

PubMed

Domonova, É A; Shipulina, O Iu; Kuevda, D A; Larichev, V F; Safonova, A P; Burchik, M A; Butenko, A M; Shipulin, G A

2012-01-01

Development of a reagent kit for detection of rubella virus RNA in clinical material by PCR-RT. During development and determination of analytical specificity and sensitivity DNA and RNA of 33 different microorganisms including 4 rubella strains were used. Comparison of analytical sensitivity of virological and molecular-biological methods was performed by using rubella virus strains Wistar RA 27/3, M-33, "Orlov", Judith. Evaluation of diagnostic informativity of rubella virus RNAisolation in various clinical material by PCR-RT method was performed in comparison with determination of virus specific serum antibodies by enzyme immunoassay. A reagent kit for the detection of rubella virus RNA in clinical material by PCR-RT was developed. Analytical specificity was 100%, analytical sensitivity - 400 virus RNA copies per ml. Analytical sensitivity of the developed technique exceeds analytical sensitivity of the Vero E6 cell culture infection method in studies of rubella virus strains Wistar RA 27/3 and "Orlov" by 11g and 31g, and for M-33 and Judith strains is analogous. Diagnostic specificity is 100%. Diagnostic specificity for testing samples obtained within 5 days of rash onset: for peripheral blood sera - 20.9%, saliva - 92.5%, nasopharyngeal swabs - 70.1%, saliva and nasopharyngeal swabs - 97%. Positive and negative predictive values of the results were shown depending on the type of clinical material tested. Application of reagent kit will allow to increase rubella diagnostics effectiveness at the early stages of infectious process development, timely and qualitatively perform differential diagnostics of exanthema diseases, support tactics of anti-epidemic regime.

The use of anti-Müllerian hormone as diagnostic for gonadectomy status in dogs.

PubMed

Themmen, Axel P N; Kalra, Bhanu; Visser, Jenny A; Kumar, Ajay; Savjani, Gopal; de Gier, Jeffrey; Jaques, Scott

2016-10-01

In the veterinary practice, there is a need for a diagnostic tool to check the gonadal status in female dogs because it may be difficult to determine whether a female animal has been spayed or whether there are ovarian remnants. Although less prevalent, a similar situation pertains to male dogs. Anti-Müllerian hormone (AMH) is an important regulator of gonadal function and is a specific gonadal product that can be determined in circulation. The objective of this study was to develop and test a canine blood AMH assay as a diagnostic tool to determine the presence of functional gonadal tissue in dogs. A prospective study with a training-validation set paradigm was used. A canine AMH assay was developed and serum and plasma AMH concentrations were determined in blood samples from 46 intact female dogs, 48 spayed females, 50 intact males, and 48 castrated males collected at two separate institutes. Using a training-validation set paradigm, it was found that using cutoff values of 1.1 ng/mL (female) and 5.5 ng/mL (male) AMH, the assay reported excellent specificity and sensitivity of 100% and 90% in female dogs, and good specificity and sensitivity of 100% and 76%, in male dogs, respectively. The sensitivity in male dogs could be further enhanced by including a serum testosterone determination. This newly developed canine AMH assay is a valuable diagnostic tool to determine gonadal status in veterinary medicine. Copyright © 2016 Elsevier Inc. All rights reserved.

Can hip abduction and external rotation discriminate sacroiliac joint pain?

PubMed

Adhia, Divya Bharatkumar; Tumilty, Steve; Mani, Ramakrishnan; Milosavljevic, Stephan; Bussey, Melanie D

2016-02-01

The primary aim of the study is to determine if Hip Abduction and External Rotation (HABER) test is capable of reproducing familiar pain in individuals with low back pain (LBP) of sacroiliac joint (SIJ) origin (SIJ-positive) when compared with LBP of Non-SIJ origin (SIJ-negative). If so, the secondary aim is to determine the diagnostic accuracy of HABER test against the reference standard of pain provocation tests, and to determine which increments of the HABER test has highest sensitivity and specificity for identifying SIJ-positive individuals. Single-blinded diagnostic accuracy study. Participants [n(122)] between ages of 18-50 y, suffering from chronic non-specific LBP (≥3 months) volunteered in the study. An experienced musculoskeletal physiotherapist evaluated and classified participants into either SIJ-positive [n(45)] or SIJ-negative [n(77)], based on reference standard of pain provocation tests [≥3 positive tests = SIJ-positive]. Another musculoskeletal physiotherapist, blinded to clinical groups, evaluated participants for reproduction of familiar pain during each increment (10°, 20°, 30°, 40°, and 50°) of HABER test. The HABER test reproduced familiar pain in SIJ-positive individuals when compared with SIJ-negative individuals [p (0.001), R(2) (0.38), Exp(β) (5.95-10.32)], and demonstrated moderate level of sensitivity (67%-78%) and specificity (71%-72%) for identifying SIJ-positive individuals. Receiver operator curve analysis demonstrated that the HABER increments of ≥30° have the highest sensitivity (83%-100%) and specificity (52%-64%). The HABER test is capable of reproducing familiar pain in SIJ-positive LBP individuals and has moderate levels of sensitivity and specificity for identifying SIJ-positive LBP individuals. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Clinical Impact of Bet v 6 in Birch Pollen-Sensitized Patients.

PubMed

Gellrich, Donata; Eder, Katharina; San Nicoló, Marion; Berghaus, Alexander; Gröger, Moritz

2017-01-01

Bet v 6, a minor birch pollen allergen, is commercially available for allergen-specific IgE antibody testing. However, there is hardly any literature on the clinical impact of Bet v 6. The aim of the present study was to analyze if testing specific IgE against Bet v 6 can add valuable benefit to the standard diagnostics of birch pollen-sensitized patients, especially in patients with unknown sensitization-eliciting allergens. Birch pollen-sensitized patients with missing IgE reactivity against Bet v 1, 2, and 4 were tested for specific IgE antibodies against Bet v 6. For comparison, an equal number of randomly selected patients with birch pollen sensitization, regardless of their individual sensitization patterns, were tested for specific anti-Bet v 6. Of 57 cases with missing reactivity against the standard birch pollen allergens, 2 patients were positive for Bet v 6. In the representative sample, 3 patients showed specific IgE against Bet v 6 - resulting in a total prevalence of 5%. None of the Bet v 6-positive patients showed allergic symptoms after exposure to birch pollen or an oral allergy syndrome. An increased prevalence of asthma and a higher degree of sensitization were the only distinctive clinical features in Bet v 6-positive patients. Among birch pollen-sensitized patients, the prevalence of specific IgE against Bet v 6 is low. Further, sensitization to Bet v 6, which shows characteristics of a panallergen, remains clinically silent. Therefore, determination of anti-Bet v 6 is not considered useful in the clinical routine. © 2017 S. Karger AG, Basel.

Urinary levels of triclosan and parabens are associated with aeroallergen and food sensitization

PubMed Central

Savage, Jessica H.; Matsui, Elizabeth C.; Wood, Robert A.; Keet, Corinne A.

2013-01-01

Background Endocrine-disrupting compounds (EDCs) have immune-modulating effects. We were interested in determining their association with allergic sensitization. Objective To determine the association between EDCs and allergic sensitization and if this relationship depended on the antimicrobial properties of the EDCs and/or gender. Methods Data were obtained from the 2005–2006 National Health and Nutrition Examination Survey in which urinary bisphenol A, triclosan, benzophenone-3, and propyl, methyl, butyl and ethyl paraben, and specific IgE were available on 860 children. Aeroallergen and food sensitization were defined as having at least one positive (≥0.35 kU/L) specific IgE to an aeroallergen or a food. Logistic regression was used to determine the association of EDCs and sensitization. Analyses were adjusted for urinary creatinine, age, ethnicity, and poverty index ratio. Results The odds of aeroallergen sensitization significantly increased with the level of the antimicrobial EDCs triclosan and propyl and butyl paraben (p≤0.04). The odds of food sensitization significantly increased with the level of urinary triclosan among male subjects (odds ratio for 3rd versus 1st tertile 3.9, p=0.02 for trend). There was a significant interaction between gender and triclosan, with males being more likely to be food sensitized with exposure (p=0.03). Similar associations were not identified for the non-antimicrobial EDCs bisphenol A and benzophenone-3 (p>0.2). Conclusions As a group, EDCs are not associated with allergen sensitization. However, levels of the antimicrobial EDCs triclosan and parabens were significantly associated with allergic sensitization. The potential role of antimicrobial EDCs in allergic disease warrants further study as they are commonly used in Western society. PMID:22704536

Development of a Serological Test for Haemophilus ducreyi for Seroprevalence Studies

PubMed Central

Elkins, Christopher; Yi, Kyungcheol; Olsen, Bonnie; Thomas, Christopher; Thomas, Kevin; Morse, Stephen

2000-01-01

We developed a new enzyme immunoassay (rpEIA) for use in determining the seroprevalence of chancroid. Three highly conserved outer membrane proteins from Haemophilus ducreyi strain 35000 were cloned, overexpressed, and purified from Escherichia coli for use as antigens in the rpEIA. Serum specimens from patients with and without chancroid were assayed to determine optimum sensitivity and specificity and to establish cutoff values. On the basis of these data, rpEIA was found to be both sensitive and specific when used to test a variety of serum specimens from patients with genital ulcers and urethritis and from healthy blood donors. PMID:10747137

Sensitivity and specificity of a CAD solution for lung nodule detection on chest radiograph with CTA correlation.

PubMed

Moore, William; Ripton-Snyder, Jennifer; Wu, George; Hendler, Craig

2011-06-01

The objective of this research was to determine the sensitivity and specificity of a commercially available computer-aided detection (CAD) system for detection of lung nodule on posterior-anterior (PA) chest radiograph in a varied patient population who are referred to computed tomographic angiogram (CTA) of the chest as a reference standard. Patients who had a PA chest radiograph with concomitant CTA of the chest were included in this retrospective study. The PA chest radiograph was analyzed by a CAD device, and results were recorded. A qualitative assessment of the CAD results was performed using a 5-point Likert scale. The CTA was then reviewed to determine if there were correlative nodules. The presence of a correlative nodule between 0.5 cm and 1.5 cm was considered a positive result. The baseline sensitivity of the system was determined to be 0.707 (95% CI = 0.52-0.86), with a specificity of 0.50 (95% CI = 0.38-0.76). Positive predictive value was 0.30 (95% CI = 0.24-0.49), with a negative predictive value of 0.858 (95% CI = 0.82-0.95), and accuracy of 0.555 (95% CI = 0.40-0.66). When excluding nodules that were qualitatively determined by a thoracic radiologist to be false positives, the specificity was 0.781 (95% CI = 0.764-0.839), the positive predictive value was 0.564 (95% CI = 0.491-0.654), the negative predictive value was 0.829 (95% CI = 0.819-0.878), and the accuracy was 0.737 (95% CI = 0.721-0.801). The use of CAD for lung nodule detection on chest radiograph, when used in conjunction with an experienced radiologist, has a very good sensitivity, specificity, and accuracy.

Reducing animal experimentation in foot-and-mouth disease vaccine potency tests.

PubMed

Reeve, Richard; Cox, Sarah; Smitsaart, Eliana; Beascoechea, Claudia Perez; Haas, Bernd; Maradei, Eduardo; Haydon, Daniel T; Barnett, Paul

2011-07-26

The World Organisation for Animal Health (OIE) Terrestrial Manual and the European Pharmacopoeia (EP) still prescribe live challenge experiments for foot-and-mouth disease virus (FMDV) immunogenicity and vaccine potency tests. However, the EP allows for other validated tests for the latter, and specifically in vitro tests if a "satisfactory pass level" has been determined; serological replacements are also currently in use in South America. Much research has therefore focused on validating both ex vivo and in vitro tests to replace live challenge. However, insufficient attention has been given to the sensitivity and specificity of the "gold standard"in vivo test being replaced, despite this information being critical to determining what should be required of its replacement. This paper aims to redress this imbalance by examining the current live challenge tests and their associated statistics and determining the confidence that we can have in them, thereby setting a standard for candidate replacements. It determines that the statistics associated with the current EP PD(50) test are inappropriate given our domain knowledge, but that the OIE test statistics are satisfactory. However, it has also identified a new set of live animal challenge test regimes that provide similar sensitivity and specificity to all of the currently used OIE tests using fewer animals (16 including controls), and can also provide further savings in live animal experiments in exchange for small reductions in sensitivity and specificity. Copyright © 2011 Elsevier Ltd. All rights reserved.

The sensitivity and specificity of the Middlesex Elderly Assessment of Mental State (MEAMS) for detecting cognitive impairment after stroke.

PubMed

Cartoni, A; Lincoln, N B

2005-03-01

The aim of the study was to assess the sensitivity and specificity of the MEAMS (Golding, 1989) for detecting cognitive impairment after stroke. Stroke patients admitted to hospital received a cognitive screening assessment, the MEAMS, and a detailed cognitive assessment. The information obtained from the detailed assessment was summarised in a structured written report. From the conclusions in these reports, patients were classified as "impaired" or "not impaired" in perception, memory, executive function and language. The sensitivity and specificity of the MEAMS subtests and the overall number of tests passed were determined in relation to the presence of impairment, as given in the overall conclusion of the written reports. There were 30 stroke patients, aged 58 to 92 (mean 75.80, SD 7.94) years. Of these, 17 were men and 13 were women. The sensitivity of the MEAMS subtests ranged from 11% to 100% and the specificity ranged from 69% to 100%. The sensitivity of the overall MEAMS score was 52% and the specificity was 100%, using a cut-off score of 3 or more fails to indicate impairment. Three subtests, Orientation, Naming and Unusual views had 81% sensitivity and 50% specificity for detecting problems in language, perception or memory. The MEAMS was not a sensitive screen for overall cognitive impairment or for memory, perceptual, language, or executive function problems after stroke, but it was specific. Although screening for cognitive impairment is important, the MEAMS is not recommended as the sole method, as it produces an unacceptably high false negative rate. Three subtests (Orientation, Naming and Unusual views) had 81% sensitivity and 50% specificity for detecting cognitive problems in language, perception or memory after stroke.

Use of new World Health Organization child growth standards to assess how infant malnutrition relates to breastfeeding and mortality

PubMed Central

Vesel, Linda; Martines, Jose; Penny, Mary; Bhandari, Nita; Kirkwood, Betty R

2010-01-01

Abstract Objective To compare the estimated prevalence of malnutrition using the World Health Organization’s (WHO) child growth standards versus the National Center for Health Statistics’ (NCHS) growth reference, to examine the relationship between exclusive breastfeeding and malnutrition, and to determine the sensitivity and specificity of nutritional status indicators for predicting death during infancy. Methods A secondary analysis of data on 9424 mother–infant pairs in Ghana, India and Peru was conducted. Mothers and infants were enrolled in a trial of vitamin A supplementation during which the infants’ weight, length and feeding practices were assessed regularly. Malnutrition indicators were determined using WHO and NCHS growth standards. Findings The prevalence of stunting, wasting and underweight in infants aged < 6 months was higher with WHO than NCHS standards. However, the prevalence of underweight in infants aged 6–12 months was much lower with WHO standards. The duration of exclusive breastfeeding was not associated with malnutrition in the first 6 months of life. In infants aged < 6 months, severe underweight at the first immunization visit as determined using WHO standards had the highest sensitivity (70.2%) and specificity (85.8%) for predicting mortality in India. No indicator was a good predictor in Ghana or Peru. In infants aged 6–12 months, underweight at 6 months had the highest sensitivity and specificity for predicting mortality in Ghana (37.0% and 82.2%, respectively) and Peru (33.3% and 97.9% respectively), while wasting was the best predictor in India (sensitivity: 54.6%; specificity: 85.5%). Conclusion Malnutrition indicators determined using WHO standards were better predictors of mortality than those determined using NCHS standards. No association was found between breastfeeding duration and malnutrition at 6 months. Use of WHO child growth standards highlighted the importance of malnutrition in the first 6 months of life. PMID:20428352

The Spaeth/Richman contrast sensitivity test (SPARCS): design, reproducibility and ability to identify patients with glaucoma.

PubMed

Richman, Jesse; Zangalli, Camila; Lu, Lan; Wizov, Sheryl S; Spaeth, Eric; Spaeth, George L

2015-01-01

(1) To determine the ability of a novel, internet-based contrast sensitivity test titled the Spaeth/Richman Contrast Sensitivity Test (SPARCS) to identify patients with glaucoma. (2) To determine the test-retest reliability of SPARCS. A prospective, cross-sectional study of patients with glaucoma and controls was performed. Subjects were assessed by SPARCS and the Pelli-Robson chart. Reliability of each test was assessed by the intraclass correlation coefficient and the coefficient of repeatability. Sensitivity and specificity for identifying glaucoma was also evaluated. The intraclass correlation coefficient for SPARCS was 0.97 and 0.98 for Pelli-Robson. The coefficient of repeatability for SPARCS was ±6.7% and ±6.4% for Pelli-Robson. SPARCS identified patients with glaucoma with 79% sensitivity and 93% specificity. SPARCS has high test-retest reliability. It is easily accessible via the internet and identifies patients with glaucoma well. NCT01300949. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

IgE-mediated sensitization to malassezia in atopic dermatitis: more common in male patients and in head and neck type.

PubMed

Brodská, Petra; Panzner, Petr; Pizinger, Karel; Schmid-Grendelmeier, Peter

2014-01-01

Atopic dermatitis (AD) is a common chronic inflammatory skin disease. Malassezia, the predominant skin microbiota fungus, is considered to exacerbate AD, especially in a subset of patients with head and neck type AD (HNAD). In the present study, the relationship between AD and sensitization to Malassezia antigens was investigated. We assessed 173 patients with AD. The severity of eczema was determined with Eczema Area and Severity Index (EASI); the type of AD, namely, head and neck type, was reported as well. The total serum IgE and specific IgE to Malassezia were determined and correlated with clinical picture of AD, sex, age, and the EASI. Total IgE was elevated in 77.7% of patients. Specific IgE to Malassezia was positive (≥0.35 kU/L) in 49.1% of patients. Men were significantly more often sensitized to Malassezia antigen (58% of men vs 42% of women; P value, 0.04). Concurrently, 58% of patients with HNAD versus 42% non-HNAD patients had higher levels of specific IgE to Malassezia, this difference being nearly significant (P value, 0.06). Patients with atopy were also more frequently sensitized to Malassezia. No significant relationship between EASI and the level of total IgE or specific IgE to Malassezia was observed. In our population, IgE-mediated sensitization was found in up to 49% of all patients with AD, most common in men and in head and neck type.

Field evaluation of a malaria rapid diagnostic test (ICT Pf).

PubMed

Moonasar, Devanand; Goga, Ameena E; Kruger, Philip S; La Cock, Christine; Maharaj, Rajendra; Frean, John; Chandramohan, Daniel

2009-11-01

Malaria rapid diagnostic tests (MRDTs) are quick and easy to perform and useful for diagnosing malaria in primary health care settings. In South Africa most malaria infections are due to Plasmodium falciparurrm, and HRPII-based MRDTs have been used since 2001. Previous studies in Africa showed variability in sensitivity and specificity of HRPII-based MRDTs; hence, we conducted a field evaluation in Limpopo province to determine the accuracy of the MRDT currently used in public sector clinics and hospitals. A cross-sectional observational study was conducted to determine the sensitivity and specificity of an ICT Pf MRDT. We tested 405 patients with fever with ICT Pf MRDT and compared the results with blood film microscopy (the gold standard). RESULTS. The overall sensitivity of the ICT Pf MRDT was 99.48% (95% confidence interval (CI) 96.17-100%), while specificity was 96.26% (95% CI 94.7-100%). The positive predictive value of the test was 98.48 (99% CI 98.41-100%), and the negative predictive value was 99.52% (95% CI 96.47-100%). The ICT Pf MRDT is an appropriate test to use in the field in South Africa where laboratory facilities are not available. It has a high degree of sensitivity and acceptable level of specificity in accordance with the World Health Organization criteria. However, sensitivity of MRDT at low levels of parasitaemia (<100 parasites/microl of blood) in field conditions must still be established.

Gastroesophageal dysmotility is associated with the impairment of cough-specific quality of life in patients with cough variant asthma.

PubMed

Kanemitsu, Yoshihiro; Niimi, Akio; Matsumoto, Hisako; Iwata, Toshiyuki; Ito, Isao; Oguma, Tsuyoshi; Inoue, Hideki; Tajiri, Tomoko; Nagasaki, Tadao; Izuhara, Yumi; Petrova, Guergana; Birring, Surinder S; Mishima, Michiaki

2016-07-01

Gastroesophageal reflux disease (GERD) is known as a common comorbidity of asthma and chronic cough. The impact of GERD symptoms on cough-specific quality of life (QoL) in patients with asthmatic cough is poorly understood. The aim of this study is to determine the association of GERD symptoms with cough-specific quality of life in patients with cough variant asthma (CVA) using the Leicester Cough Questionnaire (LCQ). A total of 172 consecutive patients (121 females) with mean cough duration of 45.1 months (range 2-480 months) completed the Japanese version of the LCQ. The Frequency Scale for the Symptoms of Gastroesophageal reflux was administered to assess symptoms of acid-reflux and dysmotility. A range of clinical variables that may determine cough-specific QoL (LCQ) were estimated. The mean LCQ scores was 12.9 (SD 3.5), consistent with severe impairment in QoL. Female gender, symptoms of gastroesophageal dysmotility, sensitization to allergens (house dust and Japanese cedar pollen) and the number of sensitized allergens were associated with lower LCQ scores (i.e. impaired cough-specific QoL) in univariate regression analysis. Acid-reflux symptoms, airway hyperresponsiveness, fractional exhaled nitric oxide, and sensitization to molds were unrelated to the LCQ score. After adjustment for gender, symptoms of gastroesophageal dysmotility was the only significant determinant of impaired cough-specific QoL accounting for 23% of the variance. Cough-specific QoL is severely impaired in patients with CVA. Symptoms of gastroesophageal dysmotility are an independent predictor of cough-specific QoL of patients with CVA. Copyright © 2016 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Evaluation of echocardiography in the management of elderly patients with heart failure.

PubMed

Hendry, A; Hacking, L; Langhorne, P; Vallance, R; MacDonald, J

1999-09-01

To determine the validity of a clinical diagnosis of systolic dysfunction in elderly patients with heart failure and assess the contribution of echocardiography to their management. 61 elderly patients with a diagnosis of heart failure in a geriatric assessment unit setting. Prospective study determining sensitivity, specificity and predictive values of a clinical and radiological diagnosis compared with echocardiographic standard. Proposed management was compared before and after echocardiography. Clinical assessment was highly sensitive (93%) but lacked specificity (32%). Combining radiological and clinical diagnoses increased specificity to 58%. Echocardiography revised the lead cardiac diagnosis for 28% of patients and influenced patient management plans for 41%. For elderly patients with heart failure, echocardiography improves diagnostic accuracy and identifies those patients with potential to benefit from angiotensin-converting enzyme inhibitors.

The cut-off values of anthropometric variables for predicting mild cognitive impairment in Malaysian older adults: a large population based cross-sectional study

PubMed Central

Won, Huiloo; Abdul, Manaf Zahara; Mat Ludin, Arimi Fitri; Omar, Mohd Azahadi; Razali, Rosdinom; Shahar, Suzana

2017-01-01

Purpose Older adults are at risk of mild cognitive impairment (MCI), and simple anthropometric measurements can be used to screen for this condition. Thus, the aim of this study was to explore the cut-off values of body mass index (BMI) and waist circumference (WC) for predicting the risk of MCI in older Malaysian adults. Methods A total of 2,240 Malaysian older adults aged ≥60 years were recruited using multistage random sampling in a population based cross-sectional study. Receiver operating characteristic (ROC) curve was used to determine the cut-off values of BMI and WC with optimum sensitivity and specificity for the detection of MCI. Age, gender, years of education, smoking habit, alcohol consumption, depression, and medical conditions were used as confounding factors in this analysis. Results A BMI cut-off value of 26 kg/m2 (area under the receiver operating characteristic curve [AUC] 0.725; sensitivity 90.5%; specificity 38.8%) was appropriate in identifying the risk of getting MCI in both men and women. The optimum WC cut-offs for likelihood of MCI were 90 cm (AUC 0.745; sensitivity 78.0%; specificity 59.8%) for men and 82 cm (AUC 0.714; sensitivity 84.3%; specificity 49.7%) for women. The optimum calf circumference (CC) cut-off values for identifying MCI were 29 cm (AUC 0.731; sensitivity 72.6%; specificity 61.1%) for men and 26 cm (AUC 0.598; sensitivity 79.1%; specificity 45.3%) for women. Conclusion The cut-off values could be advocated and used as part of the screening of MCI among older Malaysian adults. There is a need to further determine the predictive values of these cut-off points on outcomes through longitudinal study design. PMID:28223785

Novel diagnostic procedure for determining metastasis to sentinel lymph nodes in breast cancer using a semi-dry dot-blot method.

PubMed

Otsubo, Ryota; Oikawa, Masahiro; Hirakawa, Hiroshi; Shibata, Kenichiro; Abe, Kuniko; Hayashi, Tomayoshi; Kinoshita, Naoe; Shigematsu, Kazuto; Hatachi, Toshiko; Yano, Hiroshi; Matsumoto, Megumi; Takagi, Katsunori; Tsuchiya, Tomoshi; Tomoshige, Koichi; Nakashima, Masahiro; Taniguchi, Hideki; Omagari, Takeyuki; Itoyanagi, Noriaki; Nagayasu, Takeshi

2014-02-15

We developed an easy, quick and cost-effective detection method for lymph node metastasis called the semi-dry dot-blot (SDB) method, which visualizes the presence of cancer cells with washing of sectioned lymph nodes by anti-pancytokeratin antibody, modifying dot-blot technology. We evaluated the validity and efficacy of the SDB method for the diagnosis of lymph node metastasis in a clinical setting (Trial 1). To evaluate the validity of the SDB method in clinical specimens, 180 dissected lymph nodes from 29 cases, including breast, gastric and colorectal cancer, were examined. Each lymph node was sliced at the maximum diameter and the sensitivity, specificity and accuracy of the SDB method were determined and compared with the final pathology report. Metastasis was detected in 32 lymph nodes (17.8%), and the sensitivity, specificity and accuracy of the SDB method were 100, 98.0 and 98.3%, respectively (Trial 2). To evaluate the efficacy of the SDB method in sentinel lymph node (SLN) biopsy, 174 SLNs from 100 cases of clinically node-negative breast cancer were analyzed. Each SLN was longitudinally sliced at 2-mm intervals and the sensitivity, specificity, accuracy and time required for the SDB method were determined and compared with the intraoperative pathology report. Metastasis was detected in 15 SLNs (8.6%), and the sensitivity, specificity, accuracy and mean required time of the SDB method were 93.3, 96.9, 96.6 and 43.3 min, respectively. The SDB method is a novel and reliable modality for the intraoperative diagnosis of SLN metastasis. © 2013 UICC.

Electrocardiogram findings in emergency department patients with syncope.

PubMed

Quinn, James; McDermott, Daniel

2011-07-01

To determine the sensitivity and specificity of the San Francisco Syncope Rule (SFSR) electrocardiogram (ECG) criteria for determining cardiac outcomes and to define the specific ECG findings that are the most important in patients with syncope. A consecutive cohort of emergency department (ED) patients with syncope or near syncope was considered. The treating emergency physicians assessed 50 predictor variables, including an ECG and rhythm assessment. For the ECG assessment, the physicians were asked to categorize the ECG as normal or abnormal based on any changes that were old or new. They also did a separate rhythm assessment and could use any of the ECGs or available monitoring strips, including prehospital strips, when making this assessment. All patients were followed up to determine a broad composite study outcome. The final ECG criterion for the SFSR was any nonsinus rhythm or new ECG changes. In this specific study, the initial assessments in the database were used to determine only cardiac-related outcomes (arrhythmia, myocardial infarction, structural, sudden death) based on set criteria, and the authors determined the sensitivity and specificity of the ECG criteria for cardiac outcomes only. All ECGs classified as "abnormal" by the study criteria were compared to the official cardiology reading to determine specific findings on the ECG. Univariate and multivariate analysis were used to determine important specific ECG and rhythm findings. A total of 684 consecutive patients were considered, with 218 having positive ECG criteria and 42 (6%) having important cardiac outcomes. ECG criteria predicted 36 of 42 patients with cardiac outcomes, with a sensitivity of 86% (95% confidence interval [CI] = 71% to 94%), a specificity of 70% (95% CI = 66% to 74%), and a negative predictive value of 99% (95% CI = 97% to 99%). Regarding specific ECG findings, any nonsinus rhythm from any source and any left bundle conduction problem (i.e., any left bundle branch block, left anterior fascicular block, left posterior fascicular block, or QRS widening) were 2.5 and 3.5 times more likely associated with significant cardiac outcomes. The ECG criteria from the SFSR are relatively simple, and if used correctly can help predict which patients are at risk of cardiac outcomes. Furthermore, any left bundle branch block conduction problems or any nonsinus rhythms found during the ED stay should be especially concerning for physicians caring for patients presenting with syncope. © 2011 by the Society for Academic Emergency Medicine.

Strain-specific variations in cation content and transport in mouse erythrocytes

PubMed Central

Rivera, Alicia; Zee, Robert Y. L.; Alper, Seth L.; Peters, Luanne L.

2013-01-01

Studies of ion transport pathophysiology in hematological disorders and tests of possible new therapeutic agents for these disorders have been carried out in various mouse models because of close functional similarities between mouse and human red cells. We have explored strain-specific differences in erythrocyte membrane physiology in 10 inbred mouse strains by determining erythrocyte contents of Na+, K+, and Mg2+, and erythrocyte transport of ions via the ouabain-sensitive Na-K pump, the amiloride-sensitive Na-H exchanger (NHE1), the volume and chloride-dependent K-Cl cotransporter (KCC), and the charybdotoxin-sensitive Gardos channel (KCNN4). Our data reveal substantial strain-specific and sex-specific differences in both ion content and trans-membrane ion transport in mouse erythrocytes. These differences demonstrate the feasibility of identifying specific quantitative trait loci for erythroid ion transport and content in genetically standardized inbred mouse strains. PMID:23482811

Strain-specific variations in cation content and transport in mouse erythrocytes.

PubMed

Rivera, Alicia; Zee, Robert Y L; Alper, Seth L; Peters, Luanne L; Brugnara, Carlo

2013-05-01

Studies of ion transport pathophysiology in hematological disorders and tests of possible new therapeutic agents for these disorders have been carried out in various mouse models because of close functional similarities between mouse and human red cells. We have explored strain-specific differences in erythrocyte membrane physiology in 10 inbred mouse strains by determining erythrocyte contents of Na(+), K(+), and Mg(2+), and erythrocyte transport of ions via the ouabain-sensitive Na-K pump, the amiloride-sensitive Na-H exchanger (NHE1), the volume and chloride-dependent K-Cl cotransporter (KCC), and the charybdotoxin-sensitive Gardos channel (KCNN4). Our data reveal substantial strain-specific and sex-specific differences in both ion content and trans-membrane ion transport in mouse erythrocytes. These differences demonstrate the feasibility of identifying specific quantitative trait loci for erythroid ion transport and content in genetically standardized inbred mouse strains.

Sensitivity and specificity of obesity diagnosis in pediatric ambulatory care in the United States.

PubMed

Walsh, Carolyn O; Milliren, Carly E; Feldman, Henry A; Taveras, Elsie M

2013-09-01

We examined the sensitivity and specificity of an obesity diagnosis in a nationally representative sample of pediatric outpatient visits. We used the 2005 to 2009 National Ambulatory Medical Care and National Hospital Ambulatory Medical Care surveys. We included visits with children 2 to 18 years, yielding a sample of 48 145 database visits. We determined 3 methods of identifying obesity: documented body mass index (BMI) ≥95th percentile; International Classification of Diseases, Ninth Revision (ICD-9) code; and positive answer to the question, "Does the patient now have obesity?" Using BMI as the gold standard, we calculated the sensitivity and specificity of a clinical obesity diagnosis. Among the 19.5% of children who were obese by BMI, 7.0% had an ICD-9 code and 15.2% had a positive response to questioning. The sensitivity of an obesity diagnosis was 15.4%, and the specificity was 99.2%. The sensitivity of the obesity diagnosis in pediatric ambulatory visits is low. Efforts are needed to increase identification of obese children.

Accuracy of ultrasound versus computed tomography urogram in detecting urinary tract calculi.

PubMed

Salinawati, B; Hing, E Y; Fam, X I; Zulfiqar, M A

2015-08-01

To determine the (i) sensitivity and specificity of ultrasound (USG) in the detection of urinary tract calculi, (ii) size of renal calculi detected on USG, and (iii) size of renal calculi not seen on USG but detected on computed tomography urogram (CTU). A total of 201 patients' USG and CTU were compared retrospectively for the presence of calculi. Sensitivity, specificity, accuracy, positive predictive value and negative predictive value of USG were calculated with CTU as the gold standard. From the 201 sets of data collected, 59 calculi were detected on both USG and CTU. The sensitivity and specificity of renal calculi detection on USG were 53% and 85% respectively. The mean size of the renal calculus detected on USG was 7.6 mm ± 4.1 mm and the mean size of the renal calculus not visualised on USG but detected on CTU was 4 mm ± 2.4 mm. The sensitivity and specificity of ureteric calculi detection on USG were 12% and 97% respectively. The sensitivity and specificity of urinary bladder calculi detection on USG were 20% and 100% respectively. This study showed that the accuracy of US in detecting renal, ureteric and urinary bladder calculi were 67%, 80% and 98% respectively.

The psychometric properties, sensitivity and specificity of the geriatric anxiety inventory, hospital anxiety and depression scale, and rating anxiety in dementia scale in aged care residents.

PubMed

Creighton, Alexandra S; Davison, Tanya E; Kissane, David W

2018-02-22

Limited research has been conducted into the identification of a valid and reliable screening measure for anxiety in aged care settings, despite it being one of the most common psychological conditions. This study aimed to determine an appropriate anxiety screening tool for aged care by comparing the reliability and validity of three commonly used measures and identifying specific cut-offs for the identification of generalized anxiety disorder (GAD). One-hundred and eighty nursing home residents (M age = 85.39 years) completed the GAI, HADS-A, and RAID, along with a structured diagnostic interview. Twenty participants (11.1%) met DSM-5 criteria for GAD. All measures had good psychometric properties , although reliability estimates for the HADS-A were sub-optimal. Privileging sensitivity , the GAI cut-off score of 9 gave sensitivity of 90.0% and specificity of 86.3%; HADS-A cut-off of 6 gave sensitivity of 90.0% and specificity of 80.6%; and RAID cut-off of 11 gave sensitivity of 85.0% and specificity of 72.5%. While all three measures had adequate reliability, validity, and cut-scores with high levels of sensitivity and specificity to detect anxiety within aged care, the GAI was the most consistently reliable and valid measure for screening for GAD.

State-of-Science Approaches to Determine Sensitive Taxa for Water Quality Criteria Derivation

EPA Science Inventory

Current Ambient Water Quality Criteria (AWQC) guidelines specify pre-defined taxa diversity requirements, which has limited chemical-specific criteria development in the U.S. to less than 100 chemicals. A priori knowledge of sensitive taxa to toxicologically similar groups of che...

Sensitivity and Specificity of CT and Its signs for Diagnosis of Strangulation in Patients with Acute Small Bowel Obstruction.

PubMed

Jha, Ashwini Kumar; Tang, Wen Hao; Bai, Zhi Bin; Xiao, Jia Quan

2014-01-01

To perform a meta-analysis to review the sensitivity and specificity of computed tomography and different known computed yomography signs for the diagnosis of strangulation in patients with acute small bowel obstruction. A comprehensive Pubmed search was performed for all reports that evaluated the use of CT and discussed different CT criteria for the diagnosis of acute SBO. Articles published in English language from January 1978 to June 2008 were included. Review articles, case reports, pictorial essays and articles without original data were excluded. The bivariate random effect model was used to obtain pooled sensitivity and pooled specificity. Summary receiver operating curve was calculated using Meta-Disc. Software Openbugs 3.0.3 was used to summarize the data. A total of 12 studies fulfilled the inclusion criteria. The pooled sensitivity and specificity of CT in the diagnosis of strangulation was 0.720 (95% CI 0.674 to 0.763) and 0.866 (95% CI 0.837 to 0.892) respectively. Among different CT signs, mesenteric edema had highest Pooled sensitivity of 0. 741 and lack of bowel wall enhancement had highest pooled specificity of 0.991. This review demonstrates that CT is highly sensitive as well as specific in the preoperative diagnosis of strangulation SBO which are in accordance with the published studies. Our analysis also shows that "presence of mesenteric fluid" is most sensitive, and "lack of bowel wall enhancement" is most specific CT sign of strangulation, and also justifies need of large scale prospective studies to validate the results obtained as well as to determine a clinical protocol.

Assessment of nodal involvement in non-small-cell lung cancer with 18F-FDG-PET/CT: mediastinal blood pool cut-off has the highest sensitivity and tumour SUVmax/2 has the highest specificity.

PubMed

Mallorie, Amy; Goldring, James; Patel, Anant; Lim, Eric; Wagner, Thomas

2017-08-01

Lymph node involvement in non-small-cell lung cancer (NSCLC) is a major factor in determining management and prognosis. We aimed to evaluate the accuracy of fluorine-18-fluorodeoxyglucose-PET/computed tomography (CT) for the assessment of nodal involvement in patients with NSCLC. In this retrospective study, we included 61 patients with suspected or confirmed resectable NSCLC over a 2-year period from April 2013 to April 2015. 221 nodes with pathological staging from surgery or endobronchial ultrasound-guided transbronchial needle aspiration were assessed using a nodal station-based analysis with original clinical reports and three different cut-offs: mediastinal blood pool (MBP), liver background and tumour standardized uptake value maximal (SUVmax)/2. Using nodal station-based analysis for activity more than tumour SUVmax/2, the sensitivity was 45%, the specificity was 89% and the negative predictive value (NPV) was 87%. For activity more than MBP, the sensitivity was 93%, the specificity was 72% and NPV was 98%. For activity more than liver background, the sensitivity was 83%, the specificity was 84% and NPV was 96%. Using a nodal staging-based analysis for accuracy at detecting N2/3 disease, for activity more than tumour SUVmax/2, the sensitivity was 59%, the specificity was 85% and NPV was 80%. For activity more than MBP, the sensitivity was 95%, the specificity was 61% and NPV was 96%. For activity more than liver background, the sensitivity was 86%, the specificity was 81% and NPV was 92%. Receiver-operating characteristic analysis showed the optimal nodal SUVmax to be more than 6.4 with a sensitivity of 45% and a specificity of 95%, with an area under the curve of 0.85. Activity more than MBP was the most sensitive cut-off with the highest sensitivity and NPV. Activity more than primary tumour SUVmax/2 was the most specific cut-off. Nodal SUVmax more than 6.4 has a high specificity of 95%.

Serologic diagnosis of West Nile and St. Louis encephalitis virus infections in domestic chickens.

PubMed

Patiris, Peter J; Oceguera, Leopoldo F; Peck, George W; Chiles, Robert E; Reisen, William K; Hanson, Carl V

2008-03-01

Adult domestic chickens were infected with West Nile virus (WNV) or St. Louis encephalitis virus (SLEV) and challenged with homologous or heterologous virus at 21 or 56 days postinfection (dpi). Sera were collected at selected time points after infection and assayed by enzyme immunoassay (EIA), plaque reduction neutralization test (PRNT), and a Western blot (WB) alternative to PRNT. EIA results were sensitive and accurate (few false positives) but not specific, requiring a confirmatory test to determine virus infection history. PRNT results generally were specific until challenge, after which test results were frequently equivocal and inadequate to determine first or second infecting virus. WB results confirmed the serologic cross-reactivity between WNV and SLEV envelope protein. Non-structural protein 1 and pre-membrane protein reactivities were highly specific for WNV during SLEV infection, but less specific for SLEV during WNV infection. WB and PRNT specificities were similar for both viruses from 6 to 14 dpi, and sensitivities to WNV were virtually identical.

Performance of a time-resolved fluorescence immunoassay for measuring varicella-zoster virus immunoglobulin G levels in adults and comparison with commercial enzyme immunoassays and Merck glycoprotein enzyme immunoassay.

PubMed

Maple, P A C; Gray, J; Breuer, J; Kafatos, G; Parker, S; Brown, D

2006-02-01

Highly sensitive and specific, quantitative assays are needed to detect varicella-zoster virus (VZV) immunoglobulin G in human sera, particularly for determining immune status and response following vaccination. A time-resolved fluorescence immunoassay (TRFIA) has been developed, and its performance was compared to that of two commercial enzyme immunoassays (EIAs) and Merck glycoprotein EIA (gpEIA). The TRFIA had equivalent sensitivity (97.8%) and high specificity (93.5%) in relation to gpEIA. A commercial (Behring) EIA compared favorably with TRFIA in terms of sensitivity (98.4%) but had lower specificity (80.7%). Another commercial EIA (Diamedix) had high specificity (97.1%) but low sensitivity (76.4%) compared to TRFIA if equivocal test results were treated as negative for VZV antibody. A novel feature of the TRFIA was that the cutoff was generated using population mixture modeling and was expressed in mIU/ml, as the assay was calibrated using the British standard VZV antibody.

Monoscopic versus stereoscopic photography in screening for clinically significant macular edema.

PubMed

Welty, Christopher J; Agarwal, Anita; Merin, Lawrence M; Chomsky, Amy

2006-01-01

The purpose of the study was to determine whether monoscopic photography could serve as an accurate tool when used to screen for clinically significant macular edema. In a masked randomized fashion, two readers evaluated monoscopic and stereoscopic retinal photographs of 100 eyes. The photographs were evaluated first individually for probable clinically significant macular edema based on the Early Treatment Diabetic Retinopathy Study criteria and then as stereoscopic pairs. Graders were evaluated for sensitivity and specificity individually and in combination. Individually, reader one had a sensitivity of 0.93 and a specificity of 0.77, and reader two had a sensitivity of 0.88 and a specificity of 0.94. In combination, the readers had a sensitivity of 0.91 and a specificity of 0.86. They correlated on 0.76 of the stereoscopic readings and 0.92 of the monoscopic readings. These results indicate that the use of monoscopic retinal photography may be an accurate screening tool for clinically significant macular edema.

Evaluation of a new reagent for anti-cytomegalovirus and anti-Epstein-Barr virus immunoglobulin G.

PubMed Central

Gutierrez, J; Maroto, M D; Piédrola, G

1994-01-01

The Enzygnost alpha method was tested against the complement fixation test and anti-VCA immunofluorescence to determine the respective titers of anti-cytomegalovirus and anti-Epstein-Barr virus immunoglobulin G antibodies. For cytomegalovirus, the Enzygnost results showed 97.99% agreement with the readings obtained by the alternative method, with 100% sensitivity and 93.7% specificity. For Epstein-Barr virus, Enzygnost showed 97.71% agreement, 100% sensitivity, and 91.11% specificity. PMID:7814510

Comparison between esophagography and chest computed tomography for evaluation of leaks after esophagectomy and gastric pull-through.

PubMed

Lantos, Joshua E; Levine, Marc S; Rubesin, Stephen E; Lau, Charles T; Torigian, Drew A

2013-03-01

To assess the diagnostic performance of esophagography and chest computed tomography (CT) for detecting leaks after esophagectomy and gastric pull-through. Our database revealed 29 patients who had undergone esophagography and chest CT after esophagectomy. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for postoperative leaks were determined for esophagography and CT, separately and combined, on the basis of a retrospective image review. Patients were also stratified for esophagograms with water-soluble contrast alone versus water-soluble contrast and high-density barium and for CT with and without oral contrast. Our findings were retrospectively compared with those reported at initial image interpretation. Clinically relevant leaks were present in 14 (48%) of 29 patients after esophagectomy. Esophagography had a sensitivity of 79%, specificity of 73%, PPV of 73%, and NPV of 79% for detecting leaks, whereas CT had a sensitivity of 86%, specificity of 33%, PPV of 55%, and NPV of 71% and esophagography and CT combined had a sensitivity of 100%, specificity of 27%, PPV of 56%, and NPV of 100%. The sensitivity of esophagography increased with high-density barium, whereas the sensitivity of CT was the same with and without oral contrast agent. Finally, esophagography and CT were seen to have a higher sensitivity and lower specificity on retrospective review compared with the results reported at initial image interpretation. Esophagography had a slightly lower sensitivity and substantially higher specificity compared with CT for detecting leaks after esophagectomy, whereas esophagography and CT combined had a sensitivity of 100% for detecting leaks. Therefore, postoperative leaks can be excluded with confidence after esophagectomy when both tests are negative.

Sensitivity and specificity for detecting early glaucoma in eyes with high myopia from normative database of macular ganglion cell complex thickness obtained from normal non-myopic or highly myopic Asian eyes.

PubMed

Nakanishi, Hideo; Akagi, Tadamichi; Hangai, Masanori; Kimura, Yugo; Suda, Kenji; Kumagai, Kyoko Kawashima; Morooka, Satoshi; Ikeda, Hanako Ohashi; Yoshimura, Nagahisa

2015-07-01

We aimed to determine the sensitivity and specificity of the normative database of non-myopic and highly myopic eyes of the macular ganglion cell complex (mGCC) thickness embedded in the NIDEK RS-3000 spectral-domain optical coherence tomography (SD-OCT) for detecting early glaucoma in highly myopic eyes. Forty-seven highly myopic eyes (axial length ≥26.0 mm) of 47 subjects were studied. The SD-OCT images were used to determine the mGCC thickness within a 9-mm diameter circle centered on the fovea. The sensitivity and specificity of the non-myopic database were compared to that of the highly myopic database for distinguishing the early glaucomatous eyes from the non-glaucomatous eyes. The mGCC scans were classified as abnormal if at least one of the eight sectors of the significance map was < 1 % of the normative thickness. Twenty-one eyes were diagnosed to be non-glaucomatous and 26 eyes to have early glaucoma. . The average mGCC thickness was significantly thinner (80.9 ± 8.5 μm) in the early glaucoma group than in the non-glaucomatous group (91.2 ± 7.5 μm; p <1 × 10(-4)). The sensitivity was 96.2 % and specificity was 47.6 % when the non-myopic database was used, and the sensitivity was 92.3 % and the specificity was 90.5 % when the highly myopic database was used. The difference in the specificity was significant (p < 0.01). The significantly higher specificity of the myopic normative database for detecting early glaucoma in highly myopic eyes will lead to fewer false positive diagnoses. The database obtained from highly myopic eyes should be used when evaluating the mGCC thickness of highly myopic eyes.

An evaluation of the DRI-ETG EIA method for the determination of ethyl glucuronide concentrations in clinical and post-mortem urine.

PubMed

Turfus, Sophie C; Vo, Tu; Niehaus, Nadia; Gerostamoulos, Dimitri; Beyer, Jochen

2013-06-01

A commercial enzyme immunoassay for the qualitative and semi-quantitative measurement of ethyl glucuronide (EtG) in urine was evaluated. Post-mortem (n=800), and clinical urine (n=200) samples were assayed using a Hitachi 902 analyzer. The determined concentrations were compared with those obtained using a previously published liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the quantification of EtG and ethyl sulfate. Using a cut-off of 0.5 µg/ml and LC-MS/MS limit of reporting of 0.1 µg/ml, there was a sensitivity of 60.8% and a specificity of 100% for clinical samples. For post-mortem samples, sensitivity and specificity were 82.4% and 97.1%, respectively. When reducing the cut-off to 0.1 µg/ml, the sensitivity and specificity were 83.3% and 100% for clinical samples whereas for post-mortem samples the sensitivity and specificity were 90.3 % and 88.3 %, respectively. The best trade-offs between sensitivity and specificity for LC-MS/MS limits of reporting of 0.5 and 0.1 µg/ml were achieved when using immunoassay cut-offs of 0.3 and 0.092 µg/ml, respectively. There was good correlation between quantitative results obtained by both methods but analysis of samples by LC-MS/MS gave higher concentrations than by enzyme immunoassay (EIA), with a statistically significant proportional bias (P<0.0001, Deming regression) for both sample types. The immunoassay is reliable for the qualitative and semi-quantitative presumptive detection of ethyl glucuronide in urine. Copyright © 2012 John Wiley & Sons, Ltd.

Accuracy of immunoassay and mass spectrometry urinary free cortisol in the diagnosis of Cushing's syndrome.

PubMed

Aranda, G; Careaga, M; Hanzu, F A; Patrascioiu, I; Ríos, P; Mora, M; Morales-Romero, B; Jiménez, W; Halperin, I; Casals, G

2016-10-01

Urinary free cortisol (UFC) determination by highly specific methods as mass spectrometry instead of commercially available antibody-based immunoassays is increasingly recommended. However, clinical comparisons of both analytical approaches in the screening of Cushing's syndrome (CS) are not available. The aim of this study was to evaluate the diagnostic value of mass spectrometry versus immunoassay measurements of 24 h-UFC in the screening of CS. Cross-sectional study of 33 histologically confirmed CS patients: 25 Cushing's disease, 5 adrenal CS and 3 ectopic CS; 92 non-CS patients; and 35 healthy controls. UFC by immunoassay (UFCxIA) and mass spectrometry (UFCxMS), urinary free cortisone (UFCo) and UFC:UFCo ratio were measured, together with creatinine-corrected values. Sensitivity, specificity, AUC and Landis and Koch concordance index were determined. AUC for UFCxIA and UFCxMS were 0.77 (CI 0.68-0.87) and 0.77 (CI 0.67-0.87) respectively, with a kappa coefficient 0.60 and strong Landis and Koch concordance index. The best calculated cutoff values were 359 nmol/24 h for UFCxIA (78 % sensitivity, 62 % specificity) and 258.1 nmol/24 h for UCFxMS (53 % sensitivity, 86 % specificity). The upper limit of UFCxIA and UCFxMS reference ranges were 344.7 and 169.5 nmol/24 h respectively. Sensitivity and specificity for CS diagnosis at these cutpoints were 84 and 56 % for UFCxIA and 81 and 54 % for UFCxMS. According to our data, both methods present a very similar diagnostic value. However, results suggest that lower cutoff points for mass spectrometry may be necessary in order to improve clinical sensitivity.

TSPY4 is a novel sperm-specific biomarker of semen exposure in human cervicovaginal fluids; potential use in HIV prevention and contraception studies.

PubMed

Jacot, Terry A; Zalenskaya, Irina; Mauck, Christine; Archer, David F; Doncel, Gustavo F

2013-09-01

Developing an objective, reliable method to determine semen exposure in cervicovaginal fluids is important for accurately studying the efficacy of vaginal microbicides and contraceptives. Y-chromosome biomarkers offer better stability, sensitivity, and specificity than protein biomarkers. TSPY4 belongs to the TSPY (testis-specific protein Y-encoded) family of homologous genes on the Y-chromosome. Using a multiplex PCR amplifying TSPY4, amelogenin, and Sex-determining region in the Y chromosome (SRY), our objective was to determine whether a gene in the TSPY family was a more sensitive marker of semen exposure in cervicovaginal fluids than SRY. The multiplex polymerase chain reaction (PCR) was developed using sperm and vaginal epithelial (female) DNA. Diluted sperm DNA and mixed male/female DNA was used to determine the sensitivity of the multiplex PCR. Potential interference of TSPY4 amplification by components in cervicovaginal and seminal fluids was determined. TSPY4 and SRY amplification was also investigated in women participating in a separate IRB-approved clinical study in which cervicovaginal swab DNA was collected before semen exposure and at various time points after exposure. TSPY4, SRY, and amelogenin were amplified in sperm DNA, but only amelogenin in female DNA. The limit of sperm DNA from which TSPY4 could be amplified was lower than SRY (4 pg vs 80 pg). TSPY4 could also be amplified from mixed male/female DNA. Amplification was not affected by cervicovaginal and seminal components. Using cervicovaginal swab DNA from three women before and after semen exposure, TSPY4 was detected up to 72 h post exposure while SRY detection was observed up to 24-48 h. TSPY4 was detected up to 7 days post exposure in one out of three women. We have demonstrated that TSPY4 is a new sensitive, and sperm-specific biomarker. The multiplex PCR incorporating this new biomarker has potential to be an objective measure for determining semen exposure in clinical trials of vaginal products such as contraceptives and HIV pre/post-exposure prophylaxis agents. Copyright © 2013 Elsevier Inc. All rights reserved.

Optimal search strategies for detecting health services research studies in MEDLINE

PubMed Central

Wilczynski, Nancy L.; Haynes, R. Brian; Lavis, John N.; Ramkissoonsingh, Ravi; Arnold-Oatley, Alexandra E.

2004-01-01

Background Evidence from health services research (HSR) is currently thinly spread through many journals, making it difficult for health services researchers, managers and policy-makers to find research on clinical practice guidelines and the appropriateness, process, outcomes, cost and economics of health care services. We undertook to develop and test search terms to retrieve from the MEDLINE database HSR articles meeting minimum quality standards. Methods The retrieval performance of 7445 methodologic search terms and phrases in MEDLINE (the test) were compared with a hand search of the literature (the gold standard) for each issue of 68 journal titles for the year 2000 (a total of 25 936 articles). We determined sensitivity, specificity and precision (the positive predictive value) of the MEDLINE search strategies. Results A majority of the articles that were classified as outcome assessment, but fewer than half of those in the other categories, were considered methodologically acceptable (no methodologic criteria were applied for cost studies). Combining individual search terms to maximize sensitivity, while keeping specificity at 50% or more, led to sensitivities in the range of 88.1% to 100% for several categories (specificities ranged from 52.9% to 97.4%). When terms were combined to maximize specificity while keeping sensitivity at 50% or more, specificities of 88.8% to 99.8% were achieved. When terms were combined to maximize sensitivity and specificity while minimizing the differences between the 2 measurements, most strategies for HSR categories achieved sensitivity and specificity of at least 80%. Interpretation Sensitive and specific search strategies were validated for retrieval of HSR literature from MEDLINE. These strategies have been made available for public use by the US National Library of Medicine at www.nlm.nih.gov/nichsr/hedges/search.html. PMID:15534310

Sensitivity and Specificity of Interictal EEG-fMRI for Detecting the Ictal Onset Zone at Different Statistical Thresholds

PubMed Central

Tousseyn, Simon; Dupont, Patrick; Goffin, Karolien; Sunaert, Stefan; Van Paesschen, Wim

2014-01-01

There is currently a lack of knowledge about electroencephalography (EEG)-functional magnetic resonance imaging (fMRI) specificity. Our aim was to define sensitivity and specificity of blood oxygen level dependent (BOLD) responses to interictal epileptic spikes during EEG-fMRI for detecting the ictal onset zone (IOZ). We studied 21 refractory focal epilepsy patients who had a well-defined IOZ after a full presurgical evaluation and interictal spikes during EEG-fMRI. Areas of spike-related BOLD changes overlapping the IOZ in patients were considered as true positives; if no overlap was found, they were treated as false-negatives. Matched healthy case-controls had undergone similar EEG-fMRI in order to determine true-negative and false-positive fractions. The spike-related regressor of the patient was used in the design matrix of the healthy case-control. Suprathreshold BOLD changes in the brain of controls were considered as false positives, absence of these changes as true negatives. Sensitivity and specificity were calculated for different statistical thresholds at the voxel level combined with different cluster size thresholds and represented in receiver operating characteristic (ROC)-curves. Additionally, we calculated the ROC-curves based on the cluster containing the maximal significant activation. We achieved a combination of 100% specificity and 62% sensitivity, using a Z-threshold in the interval 3.4–3.5 and cluster size threshold of 350 voxels. We could obtain higher sensitivity at the expense of specificity. Similar performance was found when using the cluster containing the maximal significant activation. Our data provide a guideline for different EEG-fMRI settings with their respective sensitivity and specificity for detecting the IOZ. The unique cluster containing the maximal significant BOLD activation was a sensitive and specific marker of the IOZ. PMID:25101049

Plasma glycosylphosphatidylinositol-specific phospholipase D predicts the change in insulin sensitivity in response to a low-fat but not a low-carbohydrate diet in obese women.

PubMed

Gray, Dona L; O'Brien, Kevin D; D'Alessio, David A; Brehm, Bonnie J; Deeg, Mark A

2008-04-01

Although circulating glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD), a minor high-density lipoprotein-associated protein, is elevated in patients with insulin resistance or high triglycerides, no information is available on the effect of weight loss or changes in insulin sensitivity on circulating GPI-PLD levels. The objective of the study was to determine the effect of weight loss and changes in insulin sensitivity on plasma GPI-PLD levels. Forty-two nondiabetic obese women were included in the study, which involved a 3-month dietary intervention randomizing patients to a low-fat or a low-carbohydrate diet. The study's main outcome measures were plasma GPI-PLD levels and insulin sensitivity as estimated by the homeostasis model assessment. The very low carbohydrate diet group lost more weight after 3 months (-7.6 +/- 3.2 vs -4.2 +/- 3.5 kg, P < .01), although the decrease in insulin resistance was similar between groups. Weight loss with either diet did not alter plasma GPI-PLD levels. However, baseline GPI-PLD levels correlated with the change in insulin sensitivity in response to the low-fat diet, whereas baseline insulin sensitivity correlated with the change in insulin sensitivity in response to the low-carbohydrate diet. Plasma GPI-PLD may serve as a clinical tool to determine the effect of a low-fat diet on insulin sensitivity.

Desmopressin test during petrosal sinus sampling: a valuable tool to discriminate pituitary or ectopic ACTH-dependent Cushing's syndrome.

PubMed

Castinetti, F; Morange, I; Dufour, H; Jaquet, P; Conte-Devolx, B; Girard, N; Brue, T

2007-09-01

Corticotropin-releasing hormone (CRH)-stimulated petrosal sinus sampling is currently the gold standard method for the differential diagnosis between pituitary and ectopic ACTH-dependent Cushing's syndrome. Our objective was to determine sensitivity and specificity of desmopressin test during petrosal sinus sampling. Forty-three patients had petrosal sinus sampling because of the lack of visible adenoma on magnetic resonance imaging (MRI) and/or because of discordant cortisol response to high-dose dexamethasone suppression test. ACTH sampling was performed in an antecubital vein, right and left petrosal sinuses, then at each location 5 and 10 min after injection of desmopressin. Diagnosis was based on the ACTH ratio between petrosal sinus and humeral vein ACTH after desmopressin test. Diagnosis was confirmed after surgery. A receiver operating characteristics curve was used to determine optimal sensitivity and specificity. Thirty-six patients had Cushing's disease (CD) and seven had ectopic ACTH secretion. A ratio > 2 after desmopressin was found in 35 of the 36 cases of CD (sensitivity: 95%). A ratio < or = 2 was found in the seven patients with ectopic ACTH secretion (specificity: 100%). Sinus sampling was ineffective in determining the left or right localization of the adenoma (sensitivity = 50%). No major adverse effects were observed during or after the procedure. Desmopressin test during petrosal sinus sampling is a safe and effective diagnostic procedure in ACTH-dependent Cushing's syndrome. It thus represents a valuable alternative to CRH.

Low sensitivity of implant sonication when screening for infection in revision surgery

PubMed Central

Van Diek, Floor M; Albers, Christiaan G M; Van Hooff, Miranda L; Meis, Jacques F; Goosen, Jon H M

2017-01-01

Background and purpose Prosthetic-joint infection (PJI) is the most serious complication of arthroplasty, and accurate identification of a potentially responsible microorganism is essential for successful antibiotic treatment. We therefore determined the diagnostic accuracy of sonication and compared it with tissue culture as a screening tool in detecting prosthetic joint infection in revision arthroplasty. Patients and methods 252 consecutive revision arthroplasty cases were enrolled. These cases were determined as being suspected or unsuspected of having infection according to standard criteria. Perioperatively, 6 periprosthetic interface tissue biopsies were obtained from each patient and the implants removed were sonicated. The sensitivity and specificity of periprosthetic tissue culture and sonication fluid cultures were determined. Results Preoperatively, 75 revision cases were classified as having PJI (33 early and 42 late) and 177 were unsuspected of having infection. Compared with tissue culture, the sensitivity of the sonication fluid analysis was low: 0.47 (95% CI: 0.35–0.59) for sonication as compared to 0.68 (95% CI: 0.56–0.78) for tissue culture. The specificity of the sonication fluid analysis was higher than that for tissue culture: 0.99 (95% CI: 0.96–1.0) as compared to 0.80 (95% CI: 0.74–0.86). Interpretation Sonication is a highly specific test for diagnosis of PJI. However, due to the low sensitivity, a negative sonication result does not rule out the presence of PJI. Thus, sonication is not of value for screening of microorganisms during revision surgery. PMID:28287012

Development and evaluation of an immunochromatographic assay using a gp51 monoclonal antibody for the detection of antibodies against the bovine leukemia virus.

PubMed

Kim, Eun-Ju; Cheong, Kwang-Myun; Joung, Ha-Kyung; Kim, Bo-Hye; Song, Jae-Young; Cho, In-Soo; Lee, Kyoung-Ki; Shin, Yeun-Kyung

2016-12-30

Infection of cattle with bovine leukemia virus (BLV) has been observed and reported worldwide, including in Korea. The onsite identification of infected cattle would help decreasing and eradicating BLV infections on farms. Here, we present a new immunochromatographic assay that employs monoclonal antibodies (MAbs) for the detection of antibodies against BLV in the field. BLV envelope glycoprotein (gp)51 was expressed in E. coli , and MAbs against recombinant BLV gp51 were generated for the development of an immunochromatographic assay to detect BLV antibodies in cattle. The sensitivity and specificity of the assay were determined by comparing these results with those obtained from a standard enzyme linked immunosorbent assay (ELISA). A total of 160 bovine sera were used to evaluate the new immunochromatographic assay. Using ELISA as a reference standard, the relative specificity and sensitivity of this assay were determined to be 94.7% and 98%, respectively. Because of its high sensitivity and specificity, this BLV antibody detection assay would be suitable for the onsite identification of BLV infection in the field.

Evaluation of Aspergillus PCR protocols for testing serum specimens.

PubMed

White, P Lewis; Mengoli, Carlo; Bretagne, Stéphane; Cuenca-Estrella, Manuel; Finnstrom, Niklas; Klingspor, Lena; Melchers, Willem J G; McCulloch, Elaine; Barnes, Rosemary A; Donnelly, J Peter; Loeffler, Juergen

2011-11-01

A panel of human serum samples spiked with various amounts of Aspergillus fumigatus genomic DNA was distributed to 23 centers within the European Aspergillus PCR Initiative to determine analytical performance of PCR. Information regarding specific methodological components and PCR performance was requested. The information provided was made anonymous, and meta-regression analysis was performed to determine any procedural factors that significantly altered PCR performance. Ninety-seven percent of protocols were able to detect a threshold of 10 genomes/ml on at least one occasion, with 83% of protocols reproducibly detecting this concentration. Sensitivity and specificity were 86.1% and 93.6%, respectively. Positive associations between sensitivity and the use of larger sample volumes, an internal control PCR, and PCR targeting the internal transcribed spacer (ITS) region were shown. Negative associations between sensitivity and the use of larger elution volumes (≥100 μl) and PCR targeting the mitochondrial genes were demonstrated. Most Aspergillus PCR protocols used to test serum generate satisfactory analytical performance. Testing serum requires less standardization, and the specific recommendations shown in this article will only improve performance.

Evaluation of Aspergillus PCR Protocols for Testing Serum Specimens▿†

PubMed Central

White, P. Lewis; Mengoli, Carlo; Bretagne, Stéphane; Cuenca-Estrella, Manuel; Finnstrom, Niklas; Klingspor, Lena; Melchers, Willem J. G.; McCulloch, Elaine; Barnes, Rosemary A.; Donnelly, J. Peter; Loeffler, Juergen

2011-01-01

A panel of human serum samples spiked with various amounts of Aspergillus fumigatus genomic DNA was distributed to 23 centers within the European Aspergillus PCR Initiative to determine analytical performance of PCR. Information regarding specific methodological components and PCR performance was requested. The information provided was made anonymous, and meta-regression analysis was performed to determine any procedural factors that significantly altered PCR performance. Ninety-seven percent of protocols were able to detect a threshold of 10 genomes/ml on at least one occasion, with 83% of protocols reproducibly detecting this concentration. Sensitivity and specificity were 86.1% and 93.6%, respectively. Positive associations between sensitivity and the use of larger sample volumes, an internal control PCR, and PCR targeting the internal transcribed spacer (ITS) region were shown. Negative associations between sensitivity and the use of larger elution volumes (≥100 μl) and PCR targeting the mitochondrial genes were demonstrated. Most Aspergillus PCR protocols used to test serum generate satisfactory analytical performance. Testing serum requires less standardization, and the specific recommendations shown in this article will only improve performance. PMID:21940479

A simple and sensitive method for determining plasma cell isotype and monoclonality in bone marrow using flowcytometry.

PubMed

van Zaanen, H C; Vet, R J; de Jong, C M; von dem Borne, A E; van Oers, M H

1995-09-01

In this paper we describe a new, rapid and sensitive method to determine plasma cell isotype and clonality in bone marrow using flowcytometry. With the use of a new fixation and permeabilization reagent (Permeafix), which preserves cell structure and morphology, and a monoclonal antibody (Mab) specific for plasma cells (B-B4), it has become possible to specifically select plasma cells and to determine the cytoplasmatic immunoglobulins by flowcytometry. Thirty successive bone marrow aspirates from multiple myeloma patients and patients with MGUS were studied as well as 10 bone marrow samples from patients with reactive plasmacytosis. Each sample was analysed both by immunofluorescence on cytospin smears and FACS analysis. There were no discrepancies between plasma cell isotype as determined by FACS and cytospin. Moreover, FACS analysis was shown to allow detection of very low numbers of plasma cells and to determine whether these plasma cells are mono- or polyclonal. Possible applications are discussed.

The link between CD8⁺ T-cell antigen-sensitivity and HIV-suppressive capacity depends on HLA restriction, target epitope and viral isolate.

PubMed

Lissina, Anna; Fastenackels, Solène; Inglesias, Maria C; Ladell, Kristin; McLaren, James E; Briceño, Olivia; Gostick, Emma; Papagno, Laura; Autran, Brigitte; Sauce, Delphine; Price, David A; Saez-Cirion, Asier; Appay, Victor

2014-02-20

Although it is established that CD8 T-cell immunity is critical for the control of HIV replication in vivo, the key factors that determine antiviral efficacy are yet to be fully elucidated. Antigen-sensitivity and T-cell receptor (TCR) avidity have been identified as potential determinants of CD8⁺ T-cell efficacy. However, there is no general consensus in this regard because the relationship between these parameters and the control of HIV infection has been established primarily in the context of immunodominant CD8⁺ T-cell responses against the Gag₂₆₃₋₂₇₂ KK10 epitope restricted by human leukocyte antigen (HLA)-B27. To investigate the relationship between antigen-sensitivity, TCR avidity and HIV-suppressive capacity in vitro across epitope specificities and HLA class I restriction elements, we used a variety of techniques to study CD8⁺ T-cell clones specific for Nef₇₃₋₈₂ QK10 and Gag₂₀₋₂₉ RY10, both restricted by HLA-A3, alongside CD8⁺ T-cell clones specific for Gag₂₆₃₋₂₇₂ KK10. For each targeted epitope, the linked parameters of antigen-sensitivity and TCR avidity correlated directly with antiviral efficacy. However, marked differences in HIV-suppressive capacity were observed between epitope specificities, HLA class I restriction elements and viral isolates. Collectively, these data emphasize the central role of the TCR as a determinant of CD8⁺ T-cell efficacy and demonstrate that the complexities of antigen recognition across epitope and HLA class I boundaries can confound simple relationships between TCR engagement and HIV suppression.

Evaluation of vaginal pH for detection of bacterial vaginosis

PubMed Central

Hemalatha, R.; Ramalaxmi, Baru Anantha; Swetha, Eluru; Balakrishna, N.; Mastromarino, Paola

2013-01-01

Background & objectives: Bacterial vaginosis (BV) is highly prevalent among women in reproductive age group. Little information exists on routine vaginal pH measurement in women with BV. We undertook this study to assess the utility of vaginal pH determination for initial evaluation of bacterial vaginosis. Methods: In this cross-sectional study vaginal swabs were collected from women with complaints of white discharge, back ache and pain abdomen attending a government hospital and a community health clinic, and subjected to vaginal pH determination, Gram stain, wet mount and whiff test. Nugent score and Amsel criteria were used for BV confirmation. Results: Of the 270 women included in the analysis, 154 had BV based on Nugents’ score. The mean vaginal pH in women with BV measured by pH strips and pH glove was 5 and 4.9, respectively. The vaginal pH was significantly higher in women with BV. Vaginal discharge was prevalent in 84.8 per cent women, however, only 56.8 per cent of these actually had BV by Nugent score (NS). Presence of clue cells and positive whiff test were significant for BV. Vaginal pH >4.5 by pH strips and pH Glove had a sensitivity of 72 and 79 per cent and specificity of 60 and 53 per cent, respectively to detect BV. Among the combination criteria, clue cells and glove pH >4.5 had highest sensitivity and specificity to detect BV. Interpretation & conclusions: Vaginal pH determination is relatively sensitive, but less specific in detecting women with BV. Inclusion of whiff test along with pH test reduced the sensitivity, but improved specificity. Both, the pH strip and pH glove are equally suitable for screening women with BV on outpatient basis. PMID:24135180

Validation of diabetes mellitus and hypertension diagnosis in computerized medical records in primary health care

PubMed Central

2011-01-01

Background Computerized Clinical Records, which are incorporated in primary health care practice, have great potential for research. In order to use this information, data quality and reliability must be assessed to prevent compromising the validity of the results. The aim of this study is to validate the diagnosis of hypertension and diabetes mellitus in the computerized clinical records of primary health care, taking the diagnosis criteria established in the most prominently used clinical guidelines as the gold standard against which what measure the sensitivity, specificity, and determine the predictive values. The gold standard for diabetes mellitus was the diagnostic criteria established in 2003 American Diabetes Association Consensus Statement for diabetic subjects. The gold standard for hypertension was the diagnostic criteria established in the Joint National Committee published in 2003. Methods A cross-sectional multicentre validation study of diabetes mellitus and hypertension diagnoses in computerized clinical records of primary health care was carried out. Diagnostic criteria from the most prominently clinical practice guidelines were considered for standard reference. Sensitivity, specificity, positive and negative predictive values, and global agreement (with kappa index), were calculated. Results were shown overall and stratified by sex and age groups. Results The agreement for diabetes mellitus with the reference standard as determined by the guideline was almost perfect (κ = 0.990), with a sensitivity of 99.53%, a specificity of 99.49%, a positive predictive value of 91.23% and a negative predictive value of 99.98%. Hypertension diagnosis showed substantial agreement with the reference standard as determined by the guideline (κ = 0.778), the sensitivity was 85.22%, the specificity 96.95%, the positive predictive value 85.24%, and the negative predictive value was 96.95%. Sensitivity results were worse in patients who also had diabetes and in those aged 70 years or over. Conclusions Our results substantiate the validity of using diagnoses of diabetes and hypertension found within the computerized clinical records for epidemiologic studies. PMID:22035202

Biological water quality monitoring using chemiluminescent and bioluminescent techniques

NASA Technical Reports Server (NTRS)

Thomas, R. R.

1978-01-01

Automated chemiluminescence and bioluminescence sensors were developed for the continuous monitoring of microbial levels in water supplies. The optimal chemical procedures were determined for the chemiluminescence system to achieve maximum sensitivity. By using hydrogen peroxide, reaction rate differentiation, ethylene diamine tetraacetic acid (EDTA), and carbon monoxide pretreatments, factors which cause interference were eliminated and specificity of the reaction for living and dead bacteria was greatly increased. By employing existing technology with some modifications, a sensitive and specific bioluminescent system was developed.

A guide to unclassified sensitive information protection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donahue, S.C.

1996-11-14

This document is a reference guide for CIC-Division employees who lead or participate in projects that use and/or produce unclassified sensitive information. It is intended for use on a case by case basis to develop project specific sensitive information handling procedures and standards. It contains criteria for identifying sensitive information and determining levels of sensitivity, and describes cost effective measures for protecting various levels of sensitive information. The goal of this document is to help establish good business practices that benefit both the Laboratory and its customers. Division personnel are encouraged to apply these guidelines.

Electrocardiographic Criteria for Left Ventricular Hypertrophy in Asians Differs from Criteria Derived from Western Populations--Community-based Data from an Asian Population.

PubMed

Xu, Chang Fen; Tan, Eugene S J; Feng, Liang; Santhanakrishnan, Rajalakshmi; Chan, Michelle M Y; Nyunt, Shwe Zin; Ng, Tze Pin; Ling, Lieng Hsi; Richards, A Mark; Lam, Carolyn S P; Lim, Toon Wei

2015-08-01

Electrocardiographic (ECG) criteria for left ventricular hypertrophy (LVH), such as the Cornell and Sokolow-Lyon voltage criteria were derived from Western populations. However, their utility and accuracy for diagnosing echocardiographic LVH in Asian populations is unclear. The objective of this study was to assess the accuracy of ECG criteria for LVH in Asians and to determine if alternative gender-specific ECG cut-offs may improve its diagnostic accuracy. ECG and echocardiographic assessments were performed on 668 community-dwelling Asian adults (50.9% women; 57 ± 10 years) in Singapore. The accuracy of ECG voltage criteria was compared to echocardiographic LVH criteria based on the American Society of Echocardiography guidelines, and Asian ethnicity and gender-specific partition values. Echocardiographic LVH was present in 93 (13.6%) adults. Cornell criteria had low sensitivity (5.5%) and high specificity (98.9%) for diagnosing LVH. Modified gender specific cut-offs (18 mm in women, 22 mm in men) improved sensitivity (8.8% to 17.5%, 0% to 14.7%, respectively) whilst preserving specificity (98.2% to 94.2%, 100% to 95.8%). Similarly, Sokolow-Lyon criteria had poor sensitivity (7.7%) and high specificity (96.1%) for diagnosing LVH. Lowering the cut-off value from 35 mm to 31 mm improved the sensitivity in women from 3.5% to 14% while preserving specificity at 94.2%. A cut-off of 36 mm was optimal in men (sensitivity of 14.7%, specificity of 95.5%). Current ECG criteria for LVH derived in Western cohorts have limited sensitivity in Asian populations. Our data suggests that ethnicity- and gender-specific ECG criteria may be needed.

Role of bone marrow cells in the growth inhibition of transplanted methylcholanthrene-induced sarcoma (MCA). [/sup 137/Cs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scuderi, P.; Rosse, C.

1981-03-01

The operation of various antitumor mechanisms in vivo remains largely unknown. The presence of specific sensitized cells in the spleen and lymph node of tumor-bearing and tumor-immune animals has been demonstrated. Such cells are more effectively revealed by secondary sensitization of the splenocytes of tumor-immune animals in vitro by reexposing them to the tumor. Tumor-immune in vitro sensitized splenocytes (ISS) are highly effective in retarding the in vivo growth of the sensitizing tumor when they are transplated together with tumor cells into normal recipient mice. However, if the same cell transfer is made into lethally irradiated mice, the tumor willmore » grow rapidly in 100% of recipients. The objective of the present study is to explore this phenomenon and to determine the origin of the host cells that are capable of collaborating with tumor-immune in vitro sensitized splenocytes in the regulation of tumor growth. We designed experiments to test whether the host cells involved in tumor growth regulation are derived from the spleen, thymus, or the bone marrow and set out to determine whether or not collaboration of the host cells with ISS was specific as far as the sensitizing tumor was concerned.« less

Simplified HCC-ART score for highly sensitive detection of small-sized and early-stage hepatocellular carcinoma in the widely used Okuda, CLIP, and BCLC staging systems.

PubMed

Attallah, Abdelfattah M; Omran, Mohamed M; Attallah, Ahmed A; Abdelrazek, Mohamed A; Farid, Khaled; El-Dosoky, Ibrahim

2017-04-01

Small-sized HCC can be effectively cured by surgery with good clinical outcomes. A highly sensitive HCC α-fetoprotein routine test (HCC-ART) for HCC diagnosis as well as a simplied form of the HCC-ART were reported in the British Journal of Cancer. Here, we verified and studied the applicability of the HCC-ART to the detection of early-stage HCC. 341 cirrhotic patients and 318 HCC patients were included in this study. For each, the HCC-ART score was calculated, and then the sensitivity, specificity, and results of an ROC curve analysis were compared between the HCC-ART and AFP when these biomarkers were used to detect small-sized HCC. Different HCC-ART cutoffs were set for the detection of different tumor sizes. The HCC-ART (AUC = 0.871, 70% sensitivity, 97% specificity) and the simplified HCC-ART (AUC = 0.934, 82% sensitivity, 100% specificity) were found to have high predictive power when attempting to separate cirrhotic patients from those with small-sized HCC. The simplified HCC-ART score was superior to AFP for determining stages according to the early Okuda (0.950 AUC, 84% sensitivity, 99% specificity), CLIP (0.945 AUC, 84% sensitivity, 99% specificity), and BCLC (1.000 AUC, 100% sensitivity, 99% specificity) staging systems. The simplified HCC-ART score was more strongly correlated than AFP and other staging systems with HCC tumor size (P < 0.0001; r = 0.8). The HCC-ART is superior to AFP for diagnosing early-stage HCC. Due to its advantages of minimal variability and a wide continuous scale for assessing HCC severity, the simplified HCC-ART has the potential to be more widely used than the original HCC-ART.

A PRELIMINARY assessment of BCG vacination in India.

PubMed

1955-01-01

A NEW ASSESSMENT ACTIVITY IN RELATION TO THE WHO/UNICEF BCG VACCINATION PROGRAMME IS DESCRIBED IN THIS REPORT: according to a detailed plan special field teams collect data on tuberculin sensitivity to determine how efficiently children are being selected for vaccination and to appraise the allergy produced by the mass vaccinations. Results of nine months' work in India have important implications for the practical BCG work.Testing of unvaccinated groups of schoolchildren shows that the pattern of tuberculin sensitivity differs in different parts of India. Specific tuberculin sensitivity is found in all areas, as evidenced by strong reactions to the 5 TU test. Many children had a low-grade non-specific sensitivity, evidenced by small reactions to 5 TU and large reactions to 100 TU. This non-specific tuberculin sensitivity was less frequent at high altitudes, and most common in low-lying humid areas: in all areas it was more prevalent than specific sensitivity.In some areas non-specific tuberculin sensitivity is so strong that it cannot be effectively distinguished from specific sensitivity: consequently, many children not infected with tuberculosis are undoubtedly being excluded from vaccination.Sample retesting of children vaccinated in the mass campaign revealed variable levels of allergy, in many instances much lower than had been expected. These results cannot be explained by a native incapacity of the Indian children to develop strong allergy-nor presumably by the vaccine used. Impairment of the vaccine by exposure to light could be no more than a contributory factor. The marked variability of the campaign results suggests that some factor connected with the handling or application of the vaccine (or possibly of the tuberculin) is involved.

Assessment of simple colorimetric procedures to determine smoking status of diabetic subjects.

PubMed

Smith, R F; Mather, H M; Ellard, G A

1998-02-01

The performance of a simple colorimetric assay for urinary nicotine metabolites to assess smoking status in diabetic subjects (n = 251) was investigated. Several variations of the colorimetric assay and a qualitative extraction procedure were evaluated in comparison with a cotinine immunoassay as the "gold standard." Among these, the best overall performance was achieved with the qualitative test (sensitivity 95%; specificity 100%). The quantitative measurement of total nicotine metabolites performed less well (sensitivity 92%; specificity 97%) but could be improved by incorporating a blank extraction (sensitivity 98%; specificity 98%). Allowance for diuresis appeared to offer no advantage over the other methods. These results support previous findings regarding the use of these colorimetric procedures in nondiabetic subjects and, contrary to other recent observations, their performance was not impaired in diabetic patients.

Sensitivity and Specificity of Human Immunodeficiency Virus Rapid Serologic Assays and Testing Algorithms in an Antenatal Clinic in Abidjan, Ivory Coast

PubMed Central

Koblavi-Dème, Stéphania; Maurice, Chantal; Yavo, Daniel; Sibailly, Toussaint S.; N′guessan, Kabran; Kamelan-Tano, Yvonne; Wiktor, Stefan Z.; Roels, Thierry H.; Chorba, Terence; Nkengasong, John N.

2001-01-01

To evaluate serologic testing algorithms for human immunodeficiency virus (HIV) based on a combination of rapid assays among persons with HIV-1 (non-B subtypes) infection, HIV-2 infection, and HIV-1–HIV-2 dual infections in Abidjan, Ivory Coast, a total of 1,216 sera with known HIV serologic status were used to evaluate the sensitivity and specificity of four rapid assays: Determine HIV-1/2, Capillus HIV-1/HIV-2, HIV-SPOT, and Genie II HIV-1/HIV-2. Two serum panels obtained from patients recently infected with HIV-1 subtypes B and non-B were also included. Based on sensitivity and specificity, three of the four rapid assays were evaluated prospectively in parallel (serum samples tested by two simultaneous rapid assays) and serial (serum samples tested by two consecutive rapid assays) testing algorithms. All assays were 100% sensitive, and specificities ranged from 99.4 to 100%. In the prospective evaluation, both the parallel and serial algorithms were 100% sensitive and specific. Our results suggest that rapid assays have high sensitivity and specificity and, when used in parallel or serial testing algorithms, yield results similar to those of enzyme-linked immunosorbent assay-based testing strategies. HIV serodiagnosis based on rapid assays may be a valuable alternative in implementing HIV prevention and surveillance programs in areas where sophisticated laboratories are difficult to establish. PMID:11325995

Bowel Ultrasonography in the Management of Crohn's Disease. A Review with Recommendations of an International Panel of Experts.

PubMed

Calabrese, Emma; Maaser, Christian; Zorzi, Francesca; Kannengiesser, Klaus; Hanauer, Stephen B; Bruining, David H; Iacucci, Marietta; Maconi, Giovanni; Novak, Kerri L; Panaccione, Remo; Strobel, Deike; Wilson, Stephanie R; Watanabe, Mamoru; Pallone, Francesco; Ghosh, Subrata

2016-05-01

Bowel ultrasonography (US) is considered a useful technique for assessing mural inflammation and complications in Crohn's disease (CD). The aim of this review is to appraise the evidence on the accuracy of bowel US for CD. In addition, we aim to provide recommendations for its optimal use. Publications were identified by literature search from 1992 to 2014 and selected based on predefined criteria: 15 or more patients; bowel US for diagnosing CD, complications, postoperative recurrence, activity; adequate reference standards; prospective study design; data reported to allow calculation of sensitivity, specificity, agreement, or correlation values; articles published in English. The search yielded 655 articles, of which 63 were found to be eligible and retrieved as full-text articles for analysis. Bowel US showed 79.7% sensitivity and 96.7% specificity for the diagnosis of suspected CD, and 89% sensitivity and 94.3% specificity for initial assessment in established patients with CD. Bowel US identified ileal CD with 92.7% sensitivity, 88.2% specificity, and colon CD with 81.8% sensitivity, 95.3% specificity, with lower accuracy for detecting proximal lesions. The oral contrast agent improves the sensitivity and specificity in determining CD lesions and in assessing sites and extent. Bowel US is a tool for evaluation of CD lesions in terms of complications, postoperative recurrence, and monitoring response to medical therapy; it reliably detects postoperative recurrence and complications, as well as offers the possibility of monitoring disease progression.

Sensitivity and Specificity of Procalcitonin in Predicting Bacterial Infections in Patients With Renal Impairment

PubMed Central

El-sayed, Dena; Grotts, Jonathan; Golgert, William A.; Sugar, Alan M.

2014-01-01

Background  It is unclear whether procalcitonin is an accurate predictor of bacterial infections in patients with renal impairment, although it is used as a biomarker for early diagnosis of sepsis. We determined the sensitivity, specificity, positive and negative predictive values, accuracy and best predictive value of procalcitonin for predicting bacterial infection in adult patients with severe renal impairment. Methods  Retrospective study at a single-center community teaching hospital involving 473 patients, ages 18–65, with Modification of Diet in Renal Disease eGFR ≤30 ml/min per 1.73 m2, admitted between January 2009 and June 2012, with 660 independent hospital visits. A positive or negative culture (blood or identifiable focus of infection) was paired to the highest procalcitonin result performed 48 hours before or after collecting the culture. Results  The sensitivity and specificity to predict bacterial infection, using a procalcitonin level threshold of 0.5 ng/mL, was 0.80 and 0.35 respectively. When isolating for presence of bacteremia, the sensitivity and specificity were 0.89 and 0.35 respectively. An equation adjusting for optimum thresholds of procalcitonin levels for predicting bacterial infection at different levels of eGFR had a sensitivity and specificity of 0.55 and 0.80 respectively. Conclusions  Procalcitonin is not a reliably sensitive or specific predictor of bacterial infection in patients with renal impairment when using a single threshold. Perhaps two thresholds should be employed, where below the lower threshold (i.e. 0.5 ng/mL) bacterial infection is unlikely with a sensitivity of 0.80, and above the higher threshold (i.e. 3.2 ng/mL) bacterial infection is very likely with a specificity of 0.75. PMID:25734138

Sensitivity and specificity of procalcitonin in predicting bacterial infections in patients with renal impairment.

PubMed

El-Sayed, Dena; Grotts, Jonathan; Golgert, William A; Sugar, Alan M

2014-09-01

It is unclear whether procalcitonin is an accurate predictor of bacterial infections in patients with renal impairment, although it is used as a biomarker for early diagnosis of sepsis. We determined the sensitivity, specificity, positive and negative predictive values, accuracy and best predictive value of procalcitonin for predicting bacterial infection in adult patients with severe renal impairment. Retrospective study at a single-center community teaching hospital involving 473 patients, ages 18-65, with Modification of Diet in Renal Disease eGFR ≤30 ml/min per 1.73 m(2), admitted between January 2009 and June 2012, with 660 independent hospital visits. A positive or negative culture (blood or identifiable focus of infection) was paired to the highest procalcitonin result performed 48 hours before or after collecting the culture. The sensitivity and specificity to predict bacterial infection, using a procalcitonin level threshold of 0.5 ng/mL, was 0.80 and 0.35 respectively. When isolating for presence of bacteremia, the sensitivity and specificity were 0.89 and 0.35 respectively. An equation adjusting for optimum thresholds of procalcitonin levels for predicting bacterial infection at different levels of eGFR had a sensitivity and specificity of 0.55 and 0.80 respectively. Procalcitonin is not a reliably sensitive or specific predictor of bacterial infection in patients with renal impairment when using a single threshold. Perhaps two thresholds should be employed, where below the lower threshold (i.e. 0.5 ng/mL) bacterial infection is unlikely with a sensitivity of 0.80, and above the higher threshold (i.e. 3.2 ng/mL) bacterial infection is very likely with a specificity of 0.75.

Sensitivity and specificity of the Eating Assessment Tool and the Volume-Viscosity Swallow Test for clinical evaluation of oropharyngeal dysphagia.

PubMed

Rofes, L; Arreola, V; Mukherjee, R; Clavé, P

2014-09-01

Oropharyngeal dysphagia (OD) is an underdiagnosed digestive disorder that causes severe nutritional and respiratory complications. Our aim was to determine the accuracy of the Eating Assessment Tool (EAT-10) and the Volume-Viscosity Swallow Test (V-VST) for clinical evaluation of OD. We studied 120 patients with swallowing difficulties and 14 healthy subjects. OD was evaluated by the 10-item screening questionnaire EAT-10 and the bedside method V-VST, videofluoroscopy (VFS) being the reference standard. The V-VST is an effort test that uses boluses of different volumes and viscosities to identify clinical signs of impaired efficacy (impaired labial seal, piecemeal deglutition, and residue) and impaired safety of swallow (cough, voice changes, and oxygen desaturation ≥3%). Discriminating ability was assessed by the AUC of the ROC curve and sensitivity and specificity values. According to VFS, prevalence of OD was 87%, 75.6% with impaired efficacy and 80.9% with impaired safety of swallow including 17.6% aspirations. The EAT-10 showed a ROC AUC of 0.89 for OD with an optimal cut-off at 2 (0.89 sensitivity and 0.82 specificity). The V-VST showed 0.94 sensitivity and 0.88 specificity for OD, 0.79 sensitivity and 0.75 specificity for impaired efficacy, 0.87 sensitivity and 0.81 specificity for impaired safety, and 0.91 sensitivity and 0.28 specificity for aspirations. Clinical methods for screening (EAT-10) and assessment (V-VST) of OD offer excellent psychometric proprieties that allow adequate management of OD. Their universal application among at-risk populations will improve the identification of patients with OD at risk for malnutrition and aspiration pneumonia. © 2014 The Authors. Neurogastroenterology & Motility published by John Wiley & Sons Ltd.

Sensitivity and specificity of the Eating Assessment Tool and the Volume-Viscosity Swallow Test for clinical evaluation of oropharyngeal dysphagia

PubMed Central

Rofes, L; Arreola, V; Mukherjee, R; Clavé, P

2014-01-01

Background Oropharyngeal dysphagia (OD) is an underdiagnosed digestive disorder that causes severe nutritional and respiratory complications. Our aim was to determine the accuracy of the Eating Assessment Tool (EAT-10) and the Volume-Viscosity Swallow Test (V-VST) for clinical evaluation of OD. Methods We studied 120 patients with swallowing difficulties and 14 healthy subjects. OD was evaluated by the 10-item screening questionnaire EAT-10 and the bedside method V-VST, videofluoroscopy (VFS) being the reference standard. The V-VST is an effort test that uses boluses of different volumes and viscosities to identify clinical signs of impaired efficacy (impaired labial seal, piecemeal deglutition, and residue) and impaired safety of swallow (cough, voice changes, and oxygen desaturation ≥3%). Discriminating ability was assessed by the AUC of the ROC curve and sensitivity and specificity values. Key Results According to VFS, prevalence of OD was 87%, 75.6% with impaired efficacy and 80.9% with impaired safety of swallow including 17.6% aspirations. The EAT-10 showed a ROC AUC of 0.89 for OD with an optimal cut-off at 2 (0.89 sensitivity and 0.82 specificity). The V-VST showed 0.94 sensitivity and 0.88 specificity for OD, 0.79 sensitivity and 0.75 specificity for impaired efficacy, 0.87 sensitivity and 0.81 specificity for impaired safety, and 0.91 sensitivity and 0.28 specificity for aspirations. Conclusions & Inferences Clinical methods for screening (EAT-10) and assessment (V-VST) of OD offer excellent psychometric proprieties that allow adequate management of OD. Their universal application among at-risk populations will improve the identification of patients with OD at risk for malnutrition and aspiration pneumonia. PMID:24909661

Sensitivity of standing radiographs to detect knee arthritis: a systematic review of Level I studies.

PubMed

Duncan, Stephen T; Khazzam, Michael S; Burnham, Jeremy M; Spindler, Kurt P; Dunn, Warren R; Wright, Rick W

2015-02-01

The purpose of this study was to perform a systematic review of the available literature to define the level of quality evidence for determining the sensitivity and specificity of different radiographic views in detecting knee osteoarthritis and to determine the impact of different grading systems on the ability to detect knee osteoarthritis. A systematic review of the literature was conducted to identify studies that evaluated the standing anteroposterior (AP) and 45° posteroanterior (PA) views for tibiofemoral and patellofemoral arthritis and those comparing the use of the Kellgren-Lawrence versus the joint space narrowing (JSN) radiographic grading systems using arthroscopy as the gold standard. A comprehensive search of PubMed, Scopus, CINAHL, the Cochrane Database, Clinicaltrial.gov, and EMBASE was performed using the keywords "osteoarthritis," "knee," "x-ray," "sensitivity," and "arthroscopy." Six studies were included in the evaluation. The 45° flexion PA view showed a higher sensitivity than the standing AP view for detecting severe arthritis involving either the medial or lateral tibiofemoral compartment. There was no difference in the specificities for the 2 views. The direct comparison of the Kellgren-Lawrence and the JSN radiographic grading systems found no clinical difference between the 2 systems regarding the sensitivities, although the specificity was greater for the JSN system. The ability to detect knee osteoarthritis continues to be difficult without using advanced imaging. However, as an inexpensive screening tool, the 45° flexion PA view is more sensitive than the standing AP view to detect severe tibiofemoral osteoarthritis. When evaluating the radiograph for severe osteoarthritis using either the Kellgren-Lawrence or JSN grading system, there is no clinical difference in the sensitivity between the 2 methods; however, the JSN may be more specific for ruling in severe osteoarthritis in the medial compartment. Level I, systematic review of Level I studies. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Analysis of the sensitivity properties of a model of vector-borne bubonic plague.

PubMed

Buzby, Megan; Neckels, David; Antolin, Michael F; Estep, Donald

2008-09-06

Model sensitivity is a key to evaluation of mathematical models in ecology and evolution, especially in complex models with numerous parameters. In this paper, we use some recently developed methods for sensitivity analysis to study the parameter sensitivity of a model of vector-borne bubonic plague in a rodent population proposed by Keeling & Gilligan. The new sensitivity tools are based on a variational analysis involving the adjoint equation. The new approach provides a relatively inexpensive way to obtain derivative information about model output with respect to parameters. We use this approach to determine the sensitivity of a quantity of interest (the force of infection from rats and their fleas to humans) to various model parameters, determine a region over which linearization at a specific parameter reference point is valid, develop a global picture of the output surface, and search for maxima and minima in a given region in the parameter space.

Evaluation of procalcitonin for diagnosis of neonatal sepsis of vertical transmission

PubMed Central

López Sastre, José B; Solís, David Pérez; Serradilla, Vicente Roqués; Colomer, Belén Fernández; Cotallo, Gil D Coto

2007-01-01

Background The results of recent studies suggest the usefulness of PCT for early diagnosis of neonatal sepsis, with varying results. The aim of this prospective multicenter study was to determine the behavior of serum PCT concentrations in both uninfected and infected neonates, and to assess the value of this marker for diagnosis of neonatal sepsis of vertical transmission. Methods PCT was measured in 827 blood samples collected prospectively from 317 neonates admitted to 13 acute-care teaching hospitals in Spain over one year. Serum PCT concentrations were determined by a specific immunoluminometric assay. The diagnostic efficacy of PCT at birth and within 12–24 h and 36–48 h of life was evaluated calculating the sensitivity, specificity, and likelihood ratio of positive and negative results. Results 169 asymptomatic newborns and 148 symptomatic newborns (confirmed vertical sepsis: 31, vertical clinical sepsis: 38, non-infectious diseases: 79) were studied. In asymptomatic neonates, PCT values at 12–24 h were significantly higher than at birth and at 36–48 h of life. Resuscitation at birth and chorioamnionitis were independently associated to PCT values. Neonates with confirmed vertical sepsis showed significantly higher PCT values than those with clinical sepsis. PCT thresholds for the diagnosis of sepsis were 0.55 ng/mL at birth (sensitivity 75.4%, specificity 72.3%); 4.7 ng/mL within 12–24 h of life (sensitivity 73.8%, specificity 80.8%); and 1.7 ng/mL within 36–48 h of life (sensitivity 77.6%, specificity 79.2%). Conclusion Serum PCT was moderately useful for the detection of sepsis of vertical transmission, and its reliability as a maker of bacterial infection requires specific cutoff values for each evaluation point over the first 48 h of life. PMID:17324267

Sensitivity and specificity of the gain short-screener for predicting substance use disorders in a large national sample of emerging adults.

PubMed

Smith, Douglas C; Bennett, Kyle M; Dennis, Michael L; Funk, Rodney R

2017-05-01

Emerging Adults (ages 18-25) have the highest prevalence of substance use disorders and rarely receive treatment from the specialty care system. Thus, it is important to have screening instruments specifically developed for emerging adults for use in Screening, Brief Intervention and Referral to Treatment (SBIRT) models. Optimal cutoffs for the widely-used GAIN Short-Screener's (GAIN-SS) Substance Disorder Screener (SDScrY) are not established specifically for emerging adults. Therefore, this study examined the sensitivity and specificity of the SDScrY in predicting emerging adult (ages 18-25) substance use disorders. We analyzed data from emerging adults in a large clinical sample (n=9,808) who completed both the five-item SDScrY (α=0.85) and the full criteria set for DSM-IV Substance Use Disorders. We estimated the sensitivity, specificity and area under the curve to determine optimal cutoffs. Analyses revealed a high correlation between the SDScrY screener and its longer parent scale (r=0.95, p<0.001). Sensitivity (83%) and specificity (95%) were highest at a cutoff score of two (AUC=94%) on the SDScrY for any past year substance use disorder. Sensitivity (85%) was also high at a cutoff score of two on the SDScrY for any past year alcohol disorder. The five-item Substance Use Disorder Screener is a sensitive and specific screener for emerging adults, and could be used to identify emerging adults who may benefit from SBIRT interventions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Stress proteins on the yeast cell surface determine resistance to osmotin, a plant antifungal protein.

PubMed

Yun, D J; Zhao, Y; Pardo, J M; Narasimhan, M L; Damsz, B; Lee, H; Abad, L R; D'Urzo, M P; Hasegawa, P M; Bressan, R A

1997-06-24

Strains of the yeast Saccharomyces cerevisiae differ in their sensitivities to tobacco osmotin, an antifungal protein of the PR-5 family. However, cells sensitive to tobacco osmotin showed resistance to osmotin-like proteins purified from the plant Atriplex nummularia, indicating a strict specificity between the antifungal protein and its target cell. A member of a gene family encoding stress proteins induced by heat and nitrogen limitation, collectively called Pir proteins, was isolated among the genes that conveyed resistance to tobacco osmotin to a susceptible strain. We show that overexpression of Pir proteins increased resistance to osmotin, whereas simultaneous deletion of all PIR genes in a tolerant strain resulted in sensitivity. Pir proteins have been immunolocalized to the cell wall. The enzymatic digestion of the cell wall of sensitive and resistant cells rendered spheroplasts equally susceptible to the cytotoxic action of tobacco osmotin but not to other osmotin-like proteins, indicating that the cell membrane interacts specifically with osmotin and facilitates its action. Our results demonstrate that fungal cell wall proteins are determinants of resistance to antifungal PR-5 proteins.

Stress proteins on the yeast cell surface determine resistance to osmotin, a plant antifungal protein

PubMed Central

Yun, Dae-Jin; Zhao, Yuan; Pardo, José M.; Narasimhan, Meena L.; Damsz, Barbara; Lee, Hyeseung; Abad, Laura R.; D’Urzo, Matilde Paino; Hasegawa, Paul M.; Bressan, Ray A.

1997-01-01

Strains of the yeast Saccharomyces cerevisiae differ in their sensitivities to tobacco osmotin, an antifungal protein of the PR-5 family. However, cells sensitive to tobacco osmotin showed resistance to osmotin-like proteins purified from the plant Atriplex nummularia, indicating a strict specificity between the antifungal protein and its target cell. A member of a gene family encoding stress proteins induced by heat and nitrogen limitation, collectively called Pir proteins, was isolated among the genes that conveyed resistance to tobacco osmotin to a susceptible strain. We show that overexpression of Pir proteins increased resistance to osmotin, whereas simultaneous deletion of all PIR genes in a tolerant strain resulted in sensitivity. Pir proteins have been immunolocalized to the cell wall. The enzymatic digestion of the cell wall of sensitive and resistant cells rendered spheroplasts equally susceptible to the cytotoxic action of tobacco osmotin but not to other osmotin-like proteins, indicating that the cell membrane interacts specifically with osmotin and facilitates its action. Our results demonstrate that fungal cell wall proteins are determinants of resistance to antifungal PR-5 proteins. PMID:9192695

Bayesian estimation of the sensitivity and specificity of individual fecal culture and Paralisa to detect Mycobacterium avium subspecies paratuberculosis infection in young farmed deer.

PubMed

Stringer, Lesley A; Jones, Geoff; Jewell, Chris P; Noble, Alasdair D; Heuer, Cord; Wilson, Peter R; Johnson, Wesley O

2013-11-01

A Bayesian latent class model was used to estimate the sensitivity and specificity of an immunoglobulin G1 serum enzyme-linked immunosorbent assay (Paralisa) and individual fecal culture to detect young deer infected with Mycobacterium avium subsp. paratuberculosis. Paired fecal and serum samples were collected, between July 2009 and April 2010, from 20 individual yearling (12-24-month-old) deer in each of 20 South Island and 18 North Island herds in New Zealand and subjected to culture and Paralisa, respectively. Two fecal samples and 16 serum samples from 356 North Island deer, and 55 fecal and 37 serum samples from 401 South Island deer, were positive. The estimate of individual fecal culture sensitivity was 77% (95% credible interval [CI] = 61-92%) with specificity of 99% (95% CI = 98-99.7%). The Paralisa sensitivity estimate was 19% (95% CI = 10-30%), with specificity of 94% (95% CI = 93-96%). All estimates were robust to variation of priors and assumptions tested in a sensitivity analysis. The data informs the use of the tests in determining infection status at the individual and herd level.

Screening for bipolar disorders in Spanish-speaking populations: sensitivity and specificity of the Bipolar Spectrum Diagnostic Scale-Spanish Version.

PubMed

Vázquez, Gustavo Héctor; Romero, Ester; Fabregues, Fernando; Pies, Ronald; Ghaemi, Nassir; Mota-Castillo, Manuel

2010-01-01

Bipolar disorder is commonly misdiagnosed, perhaps more so in Latin American and Spanish-speaking populations than in the United States. The Bipolar Spectrum Diagnostic Scale (BSDS) is a 19-item screening instrument designed to assist in screening for all types of bipolar disorder. The authors investigated the sensitivity of a Spanish-language version of the BSDS in a cohort of 65 outpatients with a diagnosis of bipolar disorder, based on a semi-structured interview and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. To determine specificity, we assessed a control group of 36 outpatients with diagnosis of unipolar major depressive disorder. The overall sensitivity of the BSDS Spanish version with bipolar disorders types I, II, and NOS was 0.70, which was slightly lower than the sensitivity in the study using the English version of the BSDS (0.76). The specificity was 0.89. When the threshold was decreased from 13 to 12, the sensitivity of the Spanish BSDS increased to 0.76 and specificity dropped to 0.81. The Spanish version of the BSDS is promising as a screening instrument in Spanish-speaking populations. Copyright 2010 Elsevier Inc. All rights reserved.

Influence of Neuroblastoma Stage on Serum-Based Detection of MYCN Amplification

PubMed Central

Combaret, Valerie; Hogarty, Michael D; London, Wendy B; McGrady, Patrick; Iacono, Isabelle; Brejon, Stephanie; Swerts, Katrien; Noguera, Rosa; Gross, Nicole; Rousseau, Raphael; Puisieux, Alain

2010-01-01

Background MYCN oncogene amplification has been defined as the most important prognostic factor for neuroblastoma, the most common solid extracranial neoplasm in children. High copy numbers are strongly associated with rapid tumor progression and poor outcome, independently of tumor stage or patient age, and this has become an important factor in treatment stratification. Procedure By Real Time Quantitative PCR analysis, we evaluated the clinical relevance of circulating MYCN DNA of 267 patients with locoregional or metastatic neuroblastoma in children less than 18 months of age. Results For patients in this age group with INSS stage 4 or 4S NB and stage 3 patients, serum-based determination of MYCN DNA sequences had good sensitivity (85%, 83% and 75% respectively) and high specificity (100%) when compared to direct tumor gene determination. In contrast, the approach showed low sensitivity patients with stage 1 and 2 disease. Conclusion Our results show that the sensitivity of the serum-based MYCN DNA sequence determination depends on the stage of the disease. However, this simple, reproducible assay may represent a reasonably sensitive and very specific tool to assess tumor MYCN status in cases with stage 3 and metastatic disease for whom a wait and see strategy is often recommended. PMID:19301388

Intimate partner violence (IPV): The validity of an IPV screening instrument utilized among pregnant women in Tanzania and Vietnam

PubMed Central

Rasch, Vibeke; Van, Toan Ngo; Nguyen, Hanh Thi Thuy; Manongi, Rachel; Mushi, Declare; Meyrowitsch, Dan W.; Gammeltoft, Tine; Wu, Chun Sen

2018-01-01

Background Intimate partner violence (IPV) is a global problem that affects one-third of all women. The present study aims to develop and determine the validity of a screening instrument for the detection of IPV in pregnant women in Tanzania and Vietnam and to determine the minimum number of questions needed to identify IPV. Method An IPV screening instrument based on eight questions was tested on 1,116 Tanzanian and 1,309 Vietnamese women who attended antenatal care before 24 gestational weeks. The women were re-interviewed during their 30th-34th gestational week where the World Health Organization (WHO) IPV questionnaire was used as the gold standard. In all, 255 combinations of eight different questions were first tested on the Tanzanian study population where sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated. In the evaluation of the performance of the question combinations, different IPV types and the frequency of abusive acts were considered. The question combinations that performed best in Tanzania were subsequently evaluated in the Vietnamese study population. Results In Tanzania, a combination of three selected questions including one question on emotional IPV, one on physical IPV and one on sexual IPV was found to be most effective in identifying women who are exposed to at least one type of IPV during pregnancy (sensitivity = .80; specificity = .74). The performance of the identified combination was slightly less effective in Vietnam (sensitivity = .74; specificity = .68). Focusing on different IPV types, the best performance was found for exposure to physical IPV in both Tanzania (sensitivity = .93; specificity = .70) and Vietnam (sensitivity = .96; specificity = .55). In both countries, the sensitivity increased with the frequency of abuse whereas the specificity decreased. Conclusion By asking pregnant women three simple questions we were able to identify women who were exposed to IPV during pregnancy in two different countries. The question combination performed best in assessing physical IPV where it identified 93% and 96% of Vietnamese and Tanzanian women, respectively, who were exposed to physical IPV. PMID:29389954

The reliability, validity, sensitivity, specificity and predictive values of the Chinese version of the Rowland Universal Dementia Assessment Scale.

PubMed

Chen, Chia-Wei; Chu, Hsin; Tsai, Chia-Fen; Yang, Hui-Ling; Tsai, Jui-Chen; Chung, Min-Huey; Liao, Yuan-Mei; Chi, Mei-Ju; Chou, Kuei-Ru

2015-11-01

The purpose of this study was to translate the Rowland Universal Dementia Assessment Scale into Chinese and to evaluate the psychometric properties (reliability and validity) and the diagnostic properties (sensitivity, specificity and predictive values) of the Chinese version of the Rowland Universal Dementia Assessment Scale. The accurate detection of early dementia requires screening tools with favourable cross-cultural linguistic and appropriate sensitivity, specificity, and predictive values, particularly for Chinese-speaking populations. This was a cross-sectional, descriptive study. Overall, 130 participants suspected to have cognitive impairment were enrolled in the study. A test-retest for determining reliability was scheduled four weeks after the initial test. Content validity was determined by five experts, whereas construct validity was established by using contrasted group technique. The participants' clinical diagnoses were used as the standard in calculating the sensitivity, specificity, positive predictive value and negative predictive value. The study revealed that the Chinese version of the Rowland Universal Dementia Assessment Scale exhibited a test-retest reliability of 0.90, an internal consistency reliability of 0.71, an inter-rater reliability (kappa value) of 0.88 and a content validity index of 0.97. Both the patients and healthy contrast group exhibited significant differences in their cognitive ability. The optimal cut-off points for the Chinese version of the Rowland Universal Dementia Assessment Scale in the test for mild cognitive impairment and dementia were 24 and 22, respectively; moreover, for these two conditions, the sensitivities of the scale were 0.79 and 0.76, the specificities were 0.91 and 0.81, the areas under the curve were 0.85 and 0.78, the positive predictive values were 0.99 and 0.83 and the negative predictive values were 0.96 and 0.91 respectively. The Chinese version of the Rowland Universal Dementia Assessment Scale exhibited sound reliability, validity, sensitivity, specificity and predictive values. This scale can help clinical staff members to quickly and accurately diagnose cognitive impairment and provide appropriate treatment as early as possible. © 2015 John Wiley & Sons Ltd.

Performance characteristics of the ARCHITECT anti-HCV assay.

PubMed

Jonas, Gesa; Pelzer, Claudia; Beckert, Christian; Hausmann, Michael; Kapprell, Hans-Peter

2005-10-01

The ARCHITECT Anti-HCV assay is a fully automated high throughput chemiluminescent microparticle immunoassay (CMIA) for the detection of antibodies to structural and nonstructural proteins of the hepatitis C virus (HCV). To further enhance the performance of this test, the assay was modified to improve the specificity for blood donor specimens. The specificity of the enhanced ARCHITECT Anti-HCV assay was evaluated by screening blood donor samples randomly collected from various German blood banks, as well as hospitalized patient samples derived from Germany and the US. Additionally, antibody sensitivity was determined on commercially available anti-HCV seroconversion panels and on a commercially available worldwide anti-HCV genotype performance panel. Apparent specificity of the modified ARCHITECT Anti-HCV assay in a blood donor population consisting of 3811 specimens was 99.92%, compared to 99.76% for the current on-market assay. Additionally, antibody sensitivity was determined on commercially available anti-HCV seroconversion panels. Seroconversion sensitivity equivalent to or better than the current on-market product was observed by testing 33 seroconversion panels. This study demonstrates that the modified version of the ARCHITECT Anti-HCV assay shows improved specificity for blood donor specimens compared to the current assay on market without compromising sensitivity. With the availability of the improved ARCHITECT Anti-HCV assay and the recent launch of the ARCHITECT HIV Ag/Ab Combo assay, the ARCHITECT system now offers a full hepatitis/retrovirus menu with excellent performance on a high throughput, random access, automated analyzer, ideally suited for blood screening and diagnostic applications.

The power of data mining in diagnosis of childhood pneumonia.

PubMed

Naydenova, Elina; Tsanas, Athanasios; Howie, Stephen; Casals-Pascual, Climent; De Vos, Maarten

2016-07-01

Childhood pneumonia is the leading cause of death of children under the age of 5 years globally. Diagnostic information on the presence of infection, severity and aetiology (bacterial versus viral) is crucial for appropriate treatment. However, the derivation of such information requires advanced equipment (such as X-rays) and clinical expertise to correctly assess observational clinical signs (such as chest indrawing); both of these are often unavailable in resource-constrained settings. In this study, these challenges were addressed through the development of a suite of data mining tools, facilitating automated diagnosis through quantifiable features. Findings were validated on a large dataset comprising 780 children diagnosed with pneumonia and 801 age-matched healthy controls. Pneumonia was identified via four quantifiable vital signs (98.2% sensitivity and 97.6% specificity). Moreover, it was shown that severity can be determined through a combination of three vital signs and two lung sounds (72.4% sensitivity and 82.2% specificity); addition of a conventional biomarker (C-reactive protein) further improved severity predictions (89.1% sensitivity and 81.3% specificity). Finally, we demonstrated that aetiology can be determined using three vital signs and a newly proposed biomarker (lipocalin-2) (81.8% sensitivity and 90.6% specificity). These results suggest that a suite of carefully designed machine learning tools can be used to support multi-faceted diagnosis of childhood pneumonia in resource-constrained settings, compensating for the shortage of expensive equipment and highly trained clinicians. © 2016 The Authors.

Use of Specific IgE and Skin Prick Test to Determine Clinical Reaction Severity

PubMed Central

Ta, Von; Weldon, Brittany; Yu, Grace; Humblet, Olivier; Neale-May, Susan; Nadeau, Kari

2012-01-01

Aims To determine whether specific IgE and skin prick test correlate better in predicting reaction severity during a double-blinded placebo controlled food challenge (DBPCFC) for egg, milk, and multiple tree nut allergens. Study design Prospective study. Place and Duration of Study Department of Pediatrics, Stanford University School of Medicine, August 2009 and ongoing. Methodology We examined the reaction severity of twenty-four subjects to nine possible food allergens: milk, egg, almond, cashew, hazelnut, peanut, sesame, pecan and walnut. Specific IgE and SPT were performed before each DBPCFC. DBPCFC results were classified into mild (1), moderate (2), or severe (3) reactions using a modified Bock’s criteria. Results Twenty four subjects underwent a total of 80 DBPCFC. Eighty percent of all DBPCFCs resulted in a positive reaction. A majority, 71%, were classified as mild. No reactions occurred with a SPT of zero mm while three reactions occurred with a negative specific IgE. All reactions were reversible with medication. Conclusion These data suggest that SPT and specific IgE levels are not associated with reaction severity (p<0.64 and 0.27, respectively). We also found that combining specific IgE and SPT improved specificity but did not help to achieve clinically useful sensitivity. For instance, an SPT > 5mm had a sensitivity of 91% and specificity of 50%. Combining SPT > 5mm and IgE > 7 resulted in a reduced sensitivity of 64%. Unexpectedly, a history of anaphylaxis 70% (n=17) was not predictive of anaphylaxis on challenge 4% (n=2). PMID:22993721

A loop-mediated isothermal amplification assay for rapid and sensitive detection of bovine papular stomatitis virus.

PubMed

Kurosaki, Yohei; Okada, Sayaka; Nakamae, Sayuri; Yasuda, Jiro

2016-12-01

Bovine papular stomatitis virus (BPSV) causes pustular cutaneous disease in cattle worldwide. This paper describes the development of a specific loop-mediated isothermal amplification (LAMP) assay to detect BPSV which did not cross-react with other parapoxviruses. To assess analytical sensitivity of this LAMP assay, DNA was extracted from serially diluted BPSV from which the infectious titer was determined by a novel assay based on calf kidney epithelial cells. The LAMP assay had equivalent analytical sensitivity to quantitative PCR, and could detect as few as 86 copies of viral DNA per reaction. These results suggest that the assay is a specific and sensitive technique to rapidly diagnose bovine papular stomatitis in domestic animals. Copyright © 2016 Elsevier B.V. All rights reserved.

Determination of Cancer Cell-Based pH-Sensitive Fluorescent Carbon Nanoparticles of Cross-Linked Polydopamine by Fluorescence Sensing of Alkaline Phosphatase Activity on Coated Surfaces and Aqueous Solution.

PubMed

Kang, Eun Bi; Choi, Cheong A; Mazrad, Zihnil Adha Islamy; Kim, Sung Han; In, Insik; Park, Sung Young

2017-12-19

The tumor-specific sensitive fluorescence sensing of cellular alkaline phosphatase (ALP) activity on the basis of host-guest specific and pH sensitivity was conducted on coated surfaces and aqueous states. Cross-linked fluorescent nanoparticles (C-FNP) consisting of β-cyclodextrin (β-CD)/boronic acid (BA) and fluorescent hyaluronic acid [FNP(HA)] were conjugated to fluorescent polydopamine [FNP(pDA)]. To determine the quenching effect of this system, hydrolysis of 4-nitrophenyl phosphate (NPP) to 4-nitrophenol (NP) was performed in the cavity of β-CD in the presence of ALP activated photoinduced electron transfer (PET) between NP and C-FNP. At an ALP level of 30-1000 U/L, NP caused off-emission of C-FNP because of their specific host-guest recognition. Fluorescence can be recovered under pH shock due to cleavage of the diol bond between β-CD and BA, resulting in release of NP from the fluorescent system. Sensitivity of the assays was assessed by confocal imaging not only in aqueous states, but also for the first time on coated surfaces in MDAMB-231 and MDCK cells. This novel system demonstrated high sensitivity to ALP through generation of good electron donor/acceptor pair during the PET process. Therefore, this fluorescence sensor system can be used to enhance ALP monitoring and cancer diagnosis on both coated surfaces and in aqueous states in clinical settings.

Temporal resolution in individuals with neurological disorders

PubMed Central

Rabelo, Camila Maia; Weihing, Jeffrey A; Schochat, Eliane

2015-01-01

OBJECTIVE: Temporal processing refers to the ability of the central auditory nervous system to encode and detect subtle changes in acoustic signals. This study aims to investigate the temporal resolution ability of individuals with mesial temporal sclerosis and to determine the sensitivity and specificity of the gaps-in-noise test in identifying this type of lesion. METHOD: This prospective study investigated differences in temporal resolution between 30 individuals with normal hearing and without neurological lesions (G1) and 16 individuals with both normal hearing and mesial temporal sclerosis (G2). Test performances were compared, and the sensitivity and specificity were calculated. RESULTS: There was no difference in gap detection thresholds between the two groups, although G1 revealed better average thresholds than G2 did. The sensitivity and specificity of the gaps-in-noise test for neurological lesions were 68% and 98%, respectively. CONCLUSIONS: Temporal resolution ability is compromised in individuals with neurological lesions caused by mesial temporal sclerosis. The gaps-in-noise test was shown to be a sensitive and specific measure of central auditory dysfunction in these patients. PMID:26375561

Blinded study determination of high sensitivity and specificity microchip electrophoresis–SSCP/HA to detect mutations in the p53 gene

PubMed Central

Hestekin, Christa N.; Lin, Jennifer S.; Senderowicz, Lionel; Jakupciak, John P.; O’Connell, Catherine; Rademaker, Alfred; Barron, Annelise E.

2012-01-01

Knowledge of the genetic changes that lead to disease has grown and continues to grow at a rapid pace. However, there is a need for clinical devices that can be used routinely to translate this knowledge into the treatment of patients. Use in a clinical setting requires high sensitivity and specificity (>97%) in order to prevent misdiagnoses. Single strand conformational polymorphism (SSCP) and heteroduplex analysis (HA) are two DNA-based, complementary methods for mutation detection that are inexpensive and relatively easy to implement. However, both methods are most commonly detected by slab gel electrophoresis, which can be labor-intensive, time-consuming, and often the methods are unable to produce high sensitivity and specificity without the use of multiple analysis conditions. Here we demonstrate the first blinded study using microchip electrophoresis-SSCP/HA. We demonstrate the ability of microchip electrophoresis-SSCP/HA to detect with 98% sensitivity and specificity >100 samples from the p53 gene exons 5–9 in a blinded study in an analysis time of less than 10 minutes. PMID:22002021

The influence of viewing conditions on radiological diagnosis of periapical inflammation.

PubMed

Patel, N; Rushton, V E; Macfarlane, T V; Horner, K

2000-07-08

To determine the effect of viewing conditions upon diagnosis of early periapical inflammatory pathosis on intra-oral radiographs, and to examine the effect of observer experience upon diagnostic performance in this task. 50 observers examined 18 periapical radiographs using three different viewing conditions (room lighting; viewing box; viewing box with x2 magnification and masking). Their diagnoses were compared with an 'expert' diagnosis provided by repeated viewings of the films by two dental radiologists. Sensitivities and specificities were determined. When 'ideal' viewing conditions were used, optimal sensitivity (78%) and specificity (78%) were obtained. Use of a viewing box was associated with significantly higher specificity than the use of room lighting (P = 0.0016). Use of masking and x2 magnification was associated with significantly higher sensitivity than a viewing box alone (P = 0.004). There were few significant differences in diagnostic performance between observers, but qualified dental staff had significantly higher specificities than 4th year (P = 0.01) and 5th year (P = 0.01) students when a viewing box was used alone. This study on early periapical inflammatory pathosis gives support to guidelines which recommend the use of a viewing box, x2 magnification and masking for interpreting intra-oral radiographs. It also suggests that observer experience may influence interpretation of early periapical pathosis.

Designing Playgrounds for Multifamily Dwellings

ERIC Educational Resources Information Center

Corrado, Paul

1978-01-01

Substantive, cost-sensitive guidelines are offered for determining basic playground needs, performance specifications, and site location, as well as construction techniques, for playgrounds servicing multi-family dwellings. (MJB)

A Laboratory-Based Evaluation of Four Rapid Point-of-Care Tests for Syphilis

PubMed Central

Causer, Louise M.; Kaldor, John M.; Fairley, Christopher K.; Donovan, Basil; Karapanagiotidis, Theo; Leslie, David E.; Robertson, Peter W.; McNulty, Anna M.; Anderson, David; Wand, Handan; Conway, Damian P.; Denham, Ian; Ryan, Claire; Guy, Rebecca J.

2014-01-01

Background Syphilis point-of-care tests may reduce morbidity and ongoing transmission by increasing the proportion of people rapidly treated. Syphilis stage and co-infection with HIV may influence test performance. We evaluated four commercially available syphilis point-of-care devices in a head-to-head comparison using sera from laboratories in Australia. Methods Point-of-care tests were evaluated using sera stored at Sydney and Melbourne laboratories. Sensitivity and specificity were calculated by standard methods, comparing point-of-care results to treponemal immunoassay (IA) reference test results. Additional analyses by clinical syphilis stage, HIV status, and non-treponemal antibody titre were performed. Non-overlapping 95% confidence intervals (CI) were considered statistically significant differences in estimates. Results In total 1203 specimens were tested (736 IA-reactive, 467 IA-nonreactive). Point-of-care test sensitivities were: Determine 97.3%(95%CI:95.8–98.3), Onsite 92.5%(90.3–94.3), DPP 89.8%(87.3–91.9) and Bioline 87.8%(85.1–90.0). Specificities were: Determine 96.4%(94.1–97.8), Onsite 92.5%(90.3–94.3), DPP 98.3%(96.5–99.2), and Bioline 98.5%(96.8–99.3). Sensitivity of the Determine test was 100% for primary and 100% for secondary syphilis. The three other tests had reduced sensitivity among primary (80.4–90.2%) compared to secondary syphilis (94.3–98.6%). No significant differences in sensitivity were observed by HIV status. Test sensitivities were significantly higher among high-RPR titre (RPR≥8) (range: 94.6–99.5%) than RPR non-reactive infections (range: 76.3–92.9%). Conclusions The Determine test had the highest sensitivity overall. All tests were most sensitive among high-RPR titre infections. Point-of-care tests have a role in syphilis control programs however in developed countries with established laboratory infrastructures, the lower sensitivities of some tests observed in primary syphilis suggest these would need to be supplemented with additional tests among populations where syphilis incidence is high to avoid missing early syphilis cases. PMID:24618681

Determination of the optimum number of cardiac cycles to differentiate intra-pulmonary shunt and patent foramen ovale by saline contrast two- and three-dimensional echocardiography.

PubMed

Bhatia, Nirmanmoh; Abushora, Mohannad Y; Donneyong, Macarius M; Stoddard, Marcus F

2014-03-01

Patent foramen ovale (PFO) and intra-pulmonary shunt (IPS) are potential causes of stroke. The most optimum cardiac cycle cutoff for bubbles to appear in the left heart on saline contrast transthoracic echocardiography (TTE) as criteria to differentiate the 2 entities is unknown. Ninety-five adult patients had saline contrast transesophageal echocardiography (TEE), two-dimensional (2D) and 3DTTE. Sensitivity and specificity of each cardiac cycle as cutoff to differentiate a PFO and IPS were obtained. Transesophageal echocardiography showed IPS in 28 and PFO in 15 patients. If bubbles appeared in the left heart within the first 4 cardiac cycles (the 4th cardiac cycle rule) as compared to alternate cutoffs, a PFO was most accurately diagnosed by both 2D and 3DTTE. Bubbles appearing at or after the 5th cardiac cycle most accurately determined an IPS. 3D versus 2DTTE had a trend for a higher sensitivity (61% vs. 36%, P = 0.06), but similar specificity (94% vs. 91%) for IPS. Accuracy of 3DTTE was 84% and 2DTTE was 75% (P = 0.08) for IPS. For PFO, 2DTTE sensitivity (87%) and specificity (98%) did not differ (P = NS) from that of 3DTTE sensitivity (73%) and specificity (100%). This study demonstrates for the first time that the 4th cardiac cycle rule differentiates PFO and IPS most optimally by 2D and 3DTTE. 3DTTE appears to have higher sensitivity for diagnosing IPS. These data suggest that 3DTTE is preferable when IPS is to be diagnosed. Both methods are similar for diagnosing PFO. © 2013, Wiley Periodicals, Inc.

Diagnostic performance of rapid diagnostic tests for the diagnosis of malaria at public health facilities in north-west Ethiopia.

PubMed

Getnet, Gebeyaw; Getie, Sisay; Srivastava, Mitaly; Birhan, Wubet; Fola, Abebe A; Noedl, Harald

2015-11-01

To assess the performance of RDTs against nested polymerase chain reaction (nPCR) for the diagnosis of malaria in public health facilities in north-western Ethiopia. Cross-sectional study at public health facilities in North Gondar, Ethiopia, of 359 febrile patients with signs and symptoms consistent with malaria. Finger prick blood samples were collected for testing in a P. falciparum/pan-malaria RDTs and for molecular analysis. Sensitivity, specificity and predictive values were determined for the RDTs using nPCR as reference diagnostic method. Kappa value was determined to demonstrate the consistency of the results between the diagnostic tools. By RDTs, 22.28% (80/359) of patients tested positive for malaria, and by nPCR, 27.02% (97/359) did. In nPCR, 1.67% (6/359) and 0.28% (1/359) samples were positive for P. ovale and P. malariae, which had almost all tested negative in the RDTs. The sensitivity, specificity, positive and negative predictive values of RDTs for the diagnosis of malaria were 62.9%, 92.7%, 76.3% and 87.1%, respectively, with 0.589 measurement agreement between RDTs and nPCR. The sensitivity and specificity of RDTs for P. falciparum identification only were 70.8% and 95.2%, and 65.2% and 93.1% for P. vivax. Although RDTs are commonly used at health posts in resource-limited environments, their sensitivity and specificity for the detection and species identification of Plasmodium parasites were poor compared to nPCR, suggesting caution in interpreting RDTs results. Particularly, in the light of expanded efforts to eliminate malaria in the country, more sensitive diagnostic procedures will be needed. © 2015 John Wiley & Sons Ltd.

Accuracy of Focused Assessment with Sonography for Trauma (FAST) in Blunt Trauma Abdomen-A Prospective Study.

PubMed

Kumar, Subodh; Bansal, Virinder Kumar; Muduly, Dillip Kumar; Sharma, Pawan; Misra, Mahesh C; Chumber, Sunil; Singh, Saraman; Bhardwaj, D N

2015-12-01

Focused assessment with sonography for trauma (FAST) is a limited ultrasound examination, primarily aimed at the identification of the presence of free intraperitoneal or pericardial fluid. In the context of blunt trauma abdomen (BTA), free fluid is usually due to hemorrhage, bowel contents, or both; contributes towards the timely diagnosis of potentially life-threatening hemorrhage; and is a decision-making tool to help determine the need for further evaluation or operative intervention. Fifty patients with blunt trauma abdomen were evaluated prospectively with FAST. The findings of FAST were compared with contrast-enhanced computed tomography (CECT), laparotomy, and autopsy. Any free fluid in the abdomen was presumed to be hemoperitoneum. Sonographic findings of intra-abdominal free fluid were confirmed by CECT, laparotomy, or autopsy wherever indicated. In comparing with CECT scan, FAST had a sensitivity, specificity, and accuracy of 77.27, 100, and 79.16 %, respectively, in the detection of free fluid. When compared with surgical findings, it had a sensitivity, specificity, and accuracy of 94.44, 50, and 90 %, respectively. The sensitivity of FAST was 75 % in determining free fluid in patients who died when compared with autopsy findings. Overall sensitivity, specificity, and accuracy of FAST were 80.43, 75 and 80 %, respectively, for the detection of free fluid in the abdomen. From this study, we can safely conclude that FAST is a rapid, reliable, and feasible investigation in patients with BTA, and it can be performed easily, safely, and quickly in the emergency room with a reasonable sensitivity, specificity, and accuracy. It helps in the initial triage of patients for assessing the need for urgent surgery.

Evaluation of magnetic resonance imaging for the differentiation of inflammatory, neoplastic, and vascular intradural spinal cord diseases in the dog.

PubMed

Masciarelli, Amanda E; Griffin, John F; Fosgate, Geoffrey T; Hecht, Silke; Mankin, Joseph M; Holmes, Shannon P; Platt, Simon R; Kent, Marc; Pancotto, Theresa E; Chen, Annie V; Levine, Jonathan M

2017-07-01

Magnetic resonance imaging (MRI) is a common test for dogs with suspected intradural spinal cord lesions, however studies on diagnostic performance for this test are lacking. Objectives of this multi-institutional, retrospective, case-control study were to estimate sensitivity and specificity of MRI for (1) distinguishing between histopathologically confirmed intradural spinal cord disease versus degenerative myelopathy in dogs, (2) categorizing intradural spinal cord diseases as neoplastic, inflammatory, or vascular; and (3) determining tumor type within the etiologic category of neoplasia. Additional aims were to (1) determine whether knowledge of clinical data affects sensitivity and specificity of MRI diagnoses; and (2) report interrater agreement for MRI classification of intradural spinal lesions. Cases were recruited from participating hospital databases over a 7-year period. Three reviewers independently evaluated each MRI study prior to and after provision of clinical information. A total of 87 cases were sampled (17 degenerative myelopathy, 53 neoplasia, nine inflammatory, and eight vascular). Magnetic resonance imaging had excellent (>97.6%) sensitivity for diagnosis of intradural spinal cord lesions but specificity varied before and after provision of clinical data (68.6% vs. 82.4%, P = 0.023). Magnetic resonance imaging had good sensitivity (86.8%) and moderate specificity (64.7-72.5%) for diagnosing neoplasia. Sensitivity was lower for classifying inflammatory lesions but improved with provision of clinical data (48.1% vs. 81.5%, P = 0.015). Magnetic resonance imaging was insensitive for diagnosing vascular lesions (25.0%). Interrater agreement was very good for correctly diagnosing dogs with intradural lesions (ĸ = 0.882-0.833), and good (ĸ = 0.726-0.671) for diagnosing dogs with neoplasia. © 2017 American College of Veterinary Radiology.

Duplex criteria for determination of in-stent stenosis after angioplasty and stenting of the superficial femoral artery.

PubMed

Baril, Donald T; Rhee, Robert Y; Kim, Justine; Makaroun, Michel S; Chaer, Rabih A; Marone, Luke K

2009-01-01

Endovascular intervention is considered first-line therapy for most superficial femoral artery (SFA) occlusive disease. Duplex ultrasound (DU) criteria for SFA in-stent stenosis and correlation with angiographic data remain poorly defined. This study evaluated SFA-specific DU criteria for the assessment of SFA in-stent stenosis. From May 2003 to May 2008, 330 limbs underwent SFA angioplasty and stenting and were monitored by serial DU imaging. Suspected stenotic lesions underwent angiography and intervention when appropriate. Data pairs of DU and angiographically estimated stenosis or=50% in-stent stenosis, a PSV >or=190 had 88% sensitivity, 95% specificity, a 98% positive predictive value (PPV), and a 72% negative predictive value (NPV); for Vr, a ratio of >1.50 had 93% sensitivity, 89% specificity, a 96% PPV, and a 81% NPV. To detect >or=80% in-stent stenosis, a PSV >or=275 had 97% sensitivity, 68% specificity, a 67% PPV, and a 97% NPV; a Vr ratio >or=3.50 had 74% sensitivity, 94% specificity, a 77% PPV, and a 88% NPV. Combining a PSV >or=275 and a Vr >or=3.50 to determine >or=80% in-stent stenosis had 74% sensitivity, 94% specificity, a 88% PPV, and a 85% NPV; odds ratio was 42.17 (95% confidence interval, 10.20-174.36, P < .001) to predict >or=80% in-stent stenosis. A significant drop in ABI (>0.15) correlated with a >62% in-stent stenosis, although the adjusted correlation coefficients was low (R(2) = 0.31, P = .02). PSV and Vr appear to have a significant role in predicting in-stent stenosis. To determine >or=80% stenosis, combining PSV >or=275 cm/s and Vr >or=3.50 is highly specific and predictive.

Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) processing speed scores as measures of noncredible responding: The third generation of embedded performance validity indicators.

PubMed

Erdodi, Laszlo A; Abeare, Christopher A; Lichtenstein, Jonathan D; Tyson, Bradley T; Kucharski, Brittany; Zuccato, Brandon G; Roth, Robert M

2017-02-01

Research suggests that select processing speed measures can also serve as embedded validity indicators (EVIs). The present study examined the diagnostic utility of Wechsler Adult Intelligence Scale-Fourth Edition (WAIS-IV) subtests as EVIs in a mixed clinical sample of 205 patients medically referred for neuropsychological assessment (53.3% female, mean age = 45.1). Classification accuracy was calculated against 3 composite measures of performance validity as criterion variables. A PSI ≤79 produced a good combination of sensitivity (.23-.56) and specificity (.92-.98). A Coding scaled score ≤5 resulted in good specificity (.94-1.00), but low and variable sensitivity (.04-.28). A Symbol Search scaled score ≤6 achieved a good balance between sensitivity (.38-.64) and specificity (.88-.93). A Coding-Symbol Search scaled score difference ≥5 produced adequate specificity (.89-.91) but consistently low sensitivity (.08-.12). A 2-tailed cutoff on the Coding/Symbol Search raw score ratio (≤1.41 or ≥3.57) produced acceptable specificity (.87-.93), but low sensitivity (.15-.24). Failing ≥2 of these EVIs produced variable specificity (.81-.93) and sensitivity (.31-.59). Failing ≥3 of these EVIs stabilized specificity (.89-.94) at a small cost to sensitivity (.23-.53). Results suggest that processing speed based EVIs have the potential to provide a cost-effective and expedient method for evaluating the validity of cognitive data. Given their generally low and variable sensitivity, however, they should not be used in isolation to determine the credibility of a given response set. They also produced unacceptably high rates of false positive errors in patients with moderate-to-severe head injury. Combining evidence from multiple EVIs has the potential to improve overall classification accuracy. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Advances in tumor diagnosis using OCT and Raman spectroscopy

NASA Astrophysics Data System (ADS)

Zakharov, V. P.; Bratchenko, I. A.; Kozlov, S. V.; Moryatov, A. A.; Kornilin, D. V.; Myakinin, O. O.; Artemyev, D. N.

2014-05-01

Complex investigation of malignant tumors was performed with combined optical coherence tomography (OCT) and Raman spectroscopy (RS) setup: 22 ex vivo lung tissue samples and 23 in vivo experiments with skin tumors. It was shown that combined RS-OCT unit may be used for precise tissue morphology visualization with simultaneous tumor type determination (BCC, malignant melanoma of skin tissues, adenocarcinoma and squamous cell carcinoma of lung). Fast RS phase method for skin and lung tumors identification was proposed. It is based on alteration of Raman spectral intensity in 1300-1340, 1440-1460 and 1640-1680 cm-1 bands for healthy and malignant tissue. Complex method could identify: malignant melanoma with 88.9% sensitivity and 87.8% specificity; adenocarcinoma with 100% sensitivity and 81.5% specificity; squamous cell carcinomas with 90.9% sensitivity and 77.8% specificity.

Evaluation of the Kodak Surecell Chlamydia test for the laboratory diagnosis of adult inclusion conjunctivitis.

PubMed

Tantisira, J G; Kowalski, R P; Gordon, Y J

1995-07-01

The Kodak Surecell Chlamydia test, a rapid enzyme immunoassay, has been reported to be highly sensitive (93%) and specific (96%) for detecting chlamydial lipopolysaccharide antigen in conjunctival specimens from infants, but has not been evaluated previously in adult conjunctival specimens. This study was designed to determine the efficacy of the Kodak Surecell Chlamydia test for the laboratory diagnosis of adult inclusion conjunctivitis. Twenty Chlamydia culture-positive conjunctival specimens from adults (true-positives) and 20 true-negative specimens were tested with the Kodak Surecell Chlamydia test. The Kodak Surecell Chlamydia test was 40% (8/20) sensitive, 100% (20/20) specific, and 70% (28/40) efficient. This study indicates that the Kodak Surecell Chlamydia test, though highly specific, is less sensitive in its ability to diagnose chlamydial conjunctivitis in adults than has been reported previously in infants.

A closure test for time-specific capture-recapture data

USGS Publications Warehouse

Stanley, T.R.; Burnham, K.P.

1999-01-01

The assumption of demographic closure in the analysis of capture-recapture data under closed-population models is of fundamental importance. Yet, little progress has been made in the development of omnibus tests of the closure assumption. We present a closure test for time-specific data that, in principle, tests the null hypothesis of closed-population model M(t) against the open-population Jolly-Seber model as a specific alternative. This test is chi-square, and can be decomposed into informative components that can be interpreted to determine the nature of closure violations. The test is most sensitive to permanent emigration and least sensitive to temporary emigration, and is of intermediate sensitivity to permanent or temporary immigration. This test is a versatile tool for testing the assumption of demographic closure in the analysis of capture-recapture data.

Challenges in Routine Implementation and Quality Control of Rapid Diagnostic Tests for Malaria–Rufiji District, Tanzania

PubMed Central

McMorrow, Meredith L.; Masanja, M. Irene; Abdulla, Salim M. K.; Kahigwa, Elizeus; Kachur, S. Patrick

2018-01-01

Rapid diagnostic tests (RDTs) represent an alternative to microscopy for malaria diagnosis and have shown high sensitivity and specificity in a variety of study settings. Current World Health Organization (WHO) guidelines for quality control of RDTs provide detailed instructions on pre-field testing, but offer little guidance for quality assurance once RDTs are deployed in health facilities. From September 2006 to April 2007, we introduced a histidine-rich protein II (HRP2)-based RDT (Paracheck) for suspected malaria cases five years of age and older in nine health facilities in Rufiji District, Tanzania, to assess sensitivity and specificity of RDTs in routine use at rural health facilities. Thick blood smears were collected for all patients tested with RDTs and stained and read by laboratory personnel in each facility. Thick smears were subsequently reviewed by a reference microscopist to determine RDT sensitivity and specificity. In all nine health facilities, there were significant problems with the quality of staining and microscopy. Sensitivity and specificity of RDTs were difficult to assess given the poor quality of routine blood smear staining. Mean operational sensitivity of RDTs based on reference microscopy was 64.8%, but varied greatly by health facility, range 18.8–85.9%. Sensitivity of RDTs increased with increasing parasite density. Specificity remained high at 87.8% despite relatively poor slide quality. Institution of quality control of RDTs based on poor quality blood smear staining may impede reliable measurement of sensitivity and specificity and undermine confidence in the new diagnostic. There is an urgent need for the development of alternative quality control procedures for rapid diagnostic tests that can be performed at the facility level. PMID:18784230

The association of allergic sensitization in mother and child in breast-fed and formula-fed infants.

PubMed

Wright, A L; Stern, D A; Halonen, M

2001-01-01

Human milk contains immunologically active substances potentially capable of altering infant immune response. As part of the prospective Children's Respiratory Study, we assessed whether the association between maternal allergic status and allergic status of the child was altered by breast-feeding. Skin-prick tests for 7 common allergens were administered to 702 6-year-old children and their mothers. The percentage of children sensitized to specific allergens, maternal skin test response to that allergen, and whether or not the child was ever breast-fed was determined. Findings indicated that specific sensitization in the mother was associated with specific sensitization in the child only if the child was breast-fed. This indirectly supports the hypothesis that contents of milk differ with maternal allergic status, and appear to affect allergic status in the child. These results suggest that milk from allergic mothers either promotes a Th2 type immune response or suppresses Th1 immune response in the child.

Reliability, validity, sensitivity and specificity of Guajarati version of the Roland-Morris Disability Questionnaire.

PubMed

Nambi, S Gopal

2013-01-01

The most common instruments developed to assess the functional status of patients with Non specific low back pain is the Roland-Morris Disability Questionnaire (RMDQ). Clinical and epidemiological research related to low back pain in the Gujarati population would be facilitated by the availability of well-established outcome measures. To find the reliability, validity, sensitivity and specificity of the Gujarati version of the RMDQ for use in Non Specific Chronic low back pain. A reliability, validity, sensitivity and specificity study of Gujarati version of the Roland-Morris Disability Questionnaire (RMDQ). Thirty out patients with Non Specific Chronic low back pain were assessed by the RMDQ. Reliability is assessed by using internal consistency and the intra-class correlation coefficient (ICC). Internal construct validity is assessed by RASCH Analysis and external construct validity is assessed by association with pain and spinal movement. Clinical calculator was used to determine the sensitivity and specificity. Internal consistency of the RMDQ is found to be adequate (> 0.65) at both times, with high ICC's also at both time points. Internal construct validity of the scale is good, indicating a single underlying construct. Expected associations with pain and spinal movement confirm external construct validity. The Sensitivity and Specificity at cut off point of 0.5 was 80% and 84% with respectively positive predictive value (PPV) of 83.33% and negative predictive value (NPV) of 80.76%. The Questionnaire is at the ordinal level. The RMDQ is a one-dimensional, ordinal measure, which works well in the Gujarati population.

Determination of isocyanate specific albumin-adducts in workers exposed to toluene diisocyanates.

PubMed

Sabbioni, Gabriele; Gu, Qi; Vanimireddy, Lakshiminiranjan Reddy

2012-03-01

Toluene diisocyanates (2,4-TDI and 2,6-TDI) are important intermediates in the chemical industry. Among the main damages after low levels of TDI exposure are lung sensitization and asthma. It is therefore necessary to have sensitive and specific methods to monitor isocyanate exposure of workers. Urinary metabolites or protein adducts have been used as biomarkers in workers exposed to TDI. However, with these methods it was not possible to determine if the biomarkers result from exposure to TDI or to the corresponding toluene diamines (TDA). This work presents a new procedure for the determination of isocyanate-specific albumin adducts. Isotope dilution mass spectrometry was used to measure the adducts in albumin present in workers exposed to TDI. 2,4-TDI and 2,6-TDI formed adducts with lysine: N(ϵ)-[({3-amino-4-methylphenyl}amino)carbonyl]-lysine, N(ϵ)-[({5-amino-2-methylphenyl}amino)carbonyl]-lysine, and N(ϵ)- [({3-amino-2-methylphenyl}amino)carbonyl]-lysine. In future studies, this new method can be applied to measure TDI-exposures in workers.

Cervical and Ocular VEMP Testing in Diagnosing Superior Semicircular Canal Dehiscence.

PubMed

Hunter, Jacob B; Patel, Neil S; O'Connell, Brendan P; Carlson, Matthew L; Shepard, Neil T; McCaslin, Devin L; Wanna, George B

2017-05-01

Objective To determine the sensitivity and specificity of ocular and cervical vestibular evoked myogenic potentials (VEMPs) in the diagnosis of superior semicircular canal dehiscence (SCD) and to describe the VEMP response characteristics that are most sensitive to SCD and compare the findings to previous reports. Study Design Case series with chart review. Setting Two tertiary neurotologic referral centers. Subjects and Methods Cervical and ocular VEMP peak-to-peak amplitudes and thresholds from 39 adult patients older than 18 years with surgically confirmed SCD were compared with 84 age-matched controls. Results Using receiver operating characteristic (ROC) curves, cervical VEMP (cVEMP) amplitudes, cVEMP thresholds, and ocular VEMP (oVEMP) amplitudes had areas under the curve of 0.731, 0.912, and 0.856, respectively, all of which were statistically significant ( P < .0001). For cVEMP thresholds, at the clinical equivalent ≤85-dB normalized hearing level (nHL) threshold, the sensitivity and specificity were 97.3% and 31.3%, respectively. At the ≤70-dB nHL threshold, the sensitivity and specificity were 73.0% and 94.0%, respectively. For oVEMP amplitudes >12.0 µV, the sensitivity and specificity were 78.6% and 81.7%, respectively. Conclusion Data from this multicenter study suggest that both cVEMP thresholds and oVEMP amplitudes remain good diagnostic tests for identifying SCD, with each test dependent on a number of factors. The sensitivity and specificity of these individual tests may vary slightly between centers depending on testing parameters used.

3D fluid-attenuated inversion recovery imaging: reduced CSF artifacts and enhanced sensitivity and specificity for subarachnoid hemorrhage.

PubMed

Lummel, N; Schoepf, V; Burke, M; Brueckmann, H; Linn, J

2011-12-01

FLAIR images are highly sensitive for SAH. However, CSF flow artifacts caused by conventional FLAIR can produce false-positive results. Here, we compare 3D and 3D FLAIR sequences, focusing on their potential for containing these artifacts and their sensitivity and specificity for detection of SAHs. We evaluated the following 4 FLAIR sequences: 1) 2D FLAIR at 1.5T, 2) 2D FLAIR, 3) 2D PROPELLER-FLAIR, and 4) 3D Cube-FLAIR at 3T. All sequences were performed in 5 healthy volunteers; sequences 2 and 4 were also performed under routine conditions in 10 patients with focal epilepsy and in 10 patients with SAH. Two neuroradiologists independently conducted the analysis. The presence of flow artifacts in the ventricles and cisterns of healthy volunteers and patients with epilepsy was evaluated and scored on a 4-point scale. Mean values were calculated and compared by using paired t tests. Sensitivity and specificity for SAH detection in sequences 2 and 4 were determined. Cube-FLAIR showed almost no CSF artifacts in the volunteers and the patients with epilepsy; therefore, it was superior to any other FLAIR (P < .001). Sensitivity and specificity of SAH detection by 3T FLAIR were 58.3% and 89.4%, respectively, whereas Cube-FLAIR had a sensitivity of 95% and a specificity of 100%. Cube-FLAIR allows FLAIR imaging with almost no CSF artifacts and is, thus, particularly useful for SAH detection.

Metallized gelled monopropellants

NASA Technical Reports Server (NTRS)

Nieder, Erin G.; Harrod, Charles E.; Rodgers, Frederick C.; Rapp, Douglas C.; Palaszewski, Bryan A.

1992-01-01

Thermochemical calculations of seven metallized monopropellants were conducted to quantify theoretical specific impulse and density specific impulse performance. On the basis of theoretical performance, commercial availability of formulation constituents, and anticipated viscometric behavior, two metallized monopropellants were selected for formulation characterization: triethylene glycol dinitrate, ammonium perchlorate, aluminum and hydrogen peroxide, aluminum. Formulation goals were established, and monopropellant formulation compatibility and hazard sensitivity were experimentally determined. These experimental results indicate that the friction sensitivity, detonation susceptibility, and material handling difficulties of the elevated monopropellant formulations and their constituents pose formidable barriers to their future application as metallized monopropellants.

Detection of Plasmodium knowlesi, Plasmodium falciparum and Plasmodium vivax using loop-mediated isothermal amplification (LAMP) in a co-endemic area in Malaysia.

PubMed

Piera, Kim A; Aziz, Ammar; William, Timothy; Bell, David; González, Iveth J; Barber, Bridget E; Anstey, Nicholas M; Grigg, Matthew J

2017-01-13

Plasmodium knowlesi is the most common cause of malaria in Malaysia. However, microscopic diagnosis is inaccurate and rapid diagnostic tests (RDTs) are insufficiently sensitive. PCR is sensitive and specific but not feasible at a district level. Loop-mediated isothermal amplification (LAMP) shows potential with only basic requirements. A commercially available LAMP assay, the Eiken Loopamp™ MALARIA Pan Detection kit, is sensitive for Plasmodium falciparum and Plasmodium vivax, but has not previously been evaluated for P. knowlesi. This study aims to determine the sensitivity of this LAMP assay for detecting P. knowlesi infection. Study participants included 73 uncomplicated malaria patients with PCR species confirmation: 50 P. knowlesi, 20 P. falciparum and 3 P. vivax. Nineteen malaria-negative, non-endemic area controls were also included. The sensitivity of the Eiken Loopamp™ MALARIA Pan Detection kit (Pan LAMP) for detecting each Plasmodium species was evaluated. Sensitivity and specificity of the Eiken Loopamp™ MALARIA Pf Detection kit (Pf LAMP) for P. falciparum were also determined. The limit of detection for each LAMP assay was evaluated, with results compared to PCR. All P. knowlesi patients were also tested by CareStart™ (Pf/VOM) and OptiMAL-IT™ (Pan/Pf) RDTs. The sensitivity of the Pan LAMP assay was 100% for P. knowlesi (95% CI 92.9-100), P. falciparum (95% CI 83.2-100), and P. vivax (95% CI 29.2-100). The Pf LAMP was 100% sensitive and specific for P. falciparum detection, with all P. knowlesi samples having a negative reaction. LAMP sensitivity was superior to both RDTs, with only 10 and 28% of P. knowlesi samples testing positive to CareStart™ and OptiMAL-IT™, respectively. Limit of detection using the Pan LAMP for both P. knowlesi and P. vivax was 2 parasites/μL, comparable to PCR. For P. falciparum both the Pan LAMP and Pf LAMP demonstrated a limit of detection of 20 parasites/μL. The Eiken Loopamp™ MALARIA Pan Detection kit is sensitive for detection of P. knowlesi in low parasitaemia clinical infections, as well as P. falciparum and P. vivax. However, a P. knowlesi-specific field assay in a simpler format would assist correct species identification and initiation of optimal treatment for all malaria patients.

Risk factors for latex allergy in patients with spina bifida and latex sensitization.

PubMed

Bernardini, R; Novembre, E; Lombardi, E; Mezzetti, P; Cianferoni, A; Danti, D A; Mercurella, A; Vierucci, A

1999-05-01

Some subjects with spina bifida (SB) and latex sensitization (cutaneous and/or serum IgE) can have clinical reactions, while others may have no symptoms after the exposure to latex products. This study was carried out to determine the risk factors associated with latex allergy in patients affected with SB and latex sensitization. Fifty-nine consecutive subjects affected with SB, besides answering a questionnaire, underwent a skin-prick test (SPT) to latex and the determination of the specific serum IgE (RAST CAP) to latex. The total serum IgE concentration was determined and SPT to common aero- and food-allergens, skin tests (prick + prick) with fresh foods (kiwi, pear, orange, pineapple, tomato, banana) and RAST CAP to the same foods tested by the prick + prick technique, were also performed. Fifteen out of the 59 subjects (25%) were sensitized to latex according to the presence of IgE to latex detected by SPT (nine patients) and/or RAST CAP (13 patients). Five out of the 15 sensitized patients (33%) suffered from clinical reactions to latex (urticaria, conjunctivitis, angioedema, rhinitis, bronchial asthma) while they were using latex gloves and while inflating latex balloons. In the 15 sensitized patients, the presence of specific latex seric IgE > 3.5 kU/L (>/= class 3), a positive latex SPT, an elevated total serum IgE, and a positive prick + prick and/or a positive RAST CAP to foods, were significant (P < 0.05) risk factors associated with latex symptoms. The other factors tested (age, gender, months of intermittent bladder catheterization, surgical procedures, SPT reactivity and clinical reactions to aero-allergens and food-allergens, skin tests for fresh foods, positive RAST CAP to foods) were not significantly different in symptomatic and asymptomatic patients. Significant risk factors for symptoms to latex in patients with SB and latex sensitization were a presence of specific IgE to latex > 3.5 kU/L, a more frequent positive latex SPT, elevated total IgE, and one or more positive prick + prick and/or RAST CAP to fresh foods.

Receiver operating characteristic analysis of prediction for gastric cancer development using serum pepsinogen and Helicobacter pylori antibody tests.

PubMed

Hamashima, Chisato; Sasazuki, Shizuka; Inoue, Manami; Tsugane, Shoichiro

2017-03-09

Chronic Helicobacter pylori infection plays a central role in the development of gastric cancer as shown by biological and epidemiological studies. The H. pylori antibody and serum pepsinogen (PG) tests have been anticipated to predict gastric cancer development. We determined the predictive sensitivity and specificity of gastric cancer development using these tests. Receiver operating characteristic analysis was performed, and areas under the curve were estimated. The predictive sensitivity and specificity of gastric cancer development were compared among single tests and combined methods using serum pepsinogen and H. pylori antibody tests. From a large-scale population-based cohort of over 100,000 subjects followed between 1990 and 2004, 497 gastric cancer subjects and 497 matched healthy controls were chosen. The predictive sensitivity and specificity were low in all single tests and combination methods. The highest predictive sensitivity and specificity were obtained for the serum PG I/II ratio. The optimal PG I/II cut-off values were 2.5 and 3.0. At a PG I/II cut-off value of 3.0, the sensitivity was 86.9% and the specificity was 39.8%. Even if three biomarkers were combined, the sensitivity was 97.2% and the specificity was 21.1% when the cut-off values were 3.0 for PG I/II, 70 ng/mL for PG I, and 10.0 U/mL for H. pylori antibody. The predictive accuracy of gastric cancer development was low with the serum pepsinogen and H. pylori antibody tests even if these tests were combined. To adopt these biomarkers for gastric cancer screening, a high specificity is required. When these tests are adopted for gastric cancer screening, they should be carefully interpreted with a clear understanding of their limitations.

Promoter methylation of MCAM, ERα and ERβ in serum of early stage prostate cancer patients.

PubMed

Brait, Mariana; Banerjee, Mithu; Maldonado, Leonel; Ooki, Akira; Loyo, Myriam; Guida, Elisa; Izumchenko, Evgeny; Mangold, Leslie; Humphreys, Elizabeth; Rosenbaum, Eli; Partin, Alan; Sidransky, David; Hoque, Mohammad Obaidul

2017-02-28

Prostate cancer (PC) is the second most common cancer among men worldwide. Currently, the most common non-invasive approach for screening and risk assessment of PC is measuring the level of serum prostate-specific antigen (PSA). However, the sensitivity of PSA is 42.8 % and specificity is 41.1%. As a result, the serum PSA test leads to numerous unneeded biopsies. Therefore, a rigorous search for biomarkers for early detection of PC is ongoing. In this study, we aim to assess a panel of epigenetic markers in an intend to develop an early detection test for PC. The sensitivity and specificity of hypermethylation of MCAM was 66% and 73% respectively which is an improvement from the sensitivity and specificity of PSA. Considering a combination marker panel of MCAM, ERα and ERβ increased the sensitivity to 75% and the specificity became 70% for the minimally invasive early detection test of PC. Sixteen primary matched tumor and serum were analyzed by quantitative methylation specific PCR (QMSP) to determine analytical and clinical sensitivity of the genes tested (SSBP2, MCAM, ERα, ERβ, APC, CCND2, MGMT, GSTP1, p16 and RARβ2). Additionally, serum samples from eighty four cases of PC, thirty controls and seven cases diagnosed as high grade Prostatic Intraepithelial Neoplasia (HGPIN) were analyzed. Promoter methylation of MCAM, ERα and ERβ have a potential to be utilized as biomarker for the early detection of prostate PC as their sensitivity and specificity seem to be better than serum PSA in our cohort of samples. After robust validation in a larger prospective cohort, our findings may reduce the numbers of unwarranted prostate biopsies.

Clinical applicability of quantitative nailfold capillaroscopy in differential diagnosis of connective tissue diseases with Raynaud's phenomenon.

PubMed

Wu, Po-Chang; Huang, Min-Nung; Kuo, Yu-Min; Hsieh, Song-Chou; Yu, Chia-Li

2013-08-01

Nailfold capillaroscopy is a useful tool to distinguish primary from secondary Raynaud's phenomenon (RP) by examining the morphology of nailfold capillaries but its role in disease diagnosis is not clearly established. The purpose of this study was to evaluate the roles of quantitative nailfold capillaroscopy in differential diagnosis of connective tissue diseases (CTDs) with RP. The data between the year 2005 and 2009 were retrieved from the nailfold capillaroscopic database of National Taiwan University Hospital (NTUH). Only the data from the patients with RP were analyzed. The criteria for interpretation of capillaroscopic findings were predefined. The final diagnoses of the patients were based on the American College of Rheumatology classification criteria for individual diseases, independent of nailfold capillaroscopic findings. The sensitivity and the specificity of each capillaroscopic pattern to the diseases were determined. The data from a total of 67 patients were qualified for the current study. We found the sensitivity and specificity of scleroderma pattern for systemic sclerosis (SSc) were 89.47% and 80%, and the specificity of the early, active, and late scleroderma patterns for SSc reached 87.5%, 97.5%, and 95%, respectively. The sensitivity/specificity of systemic lupus erythematosus (SLE) pattern for SLE and polymyositis/dermatomyositis (PM/DM) pattern for PM/DM were 33.33%/95.45% and 60%/96.3%, respectively. The sensitivity/specificity of mixed connective tissue disease (MCTD) pattern for MCTD were 20%/100%. The nailfold capillaroscopic (NC) patterns may be useful in the differential diagnosis of CTDs with RP. The NC patterns for SSc and PM/DM are both sensitive and specific to the diseases, while the SLE and MCTD patterns exhibit high specificity but relatively low sensitivity. Copyright © 2012. Published by Elsevier B.V.

High-resolution melting analysis for noninvasive prenatal diagnosis of IVS-II-I (G-A) fetal DNA in minor beta-thalassemia mothers.

PubMed

Zafari, Mandana; Gill, Pooria; Kowsaryan, Mehrnoush; Alipour, Abbass; Banihashemi, Ali

2016-10-01

The high-resolution melting (HRM) technique is fast, effective and successful method for mutation detection. The aim of this study was to determine the sensitivity and specificity of the HRM method for detection of a paternally inherited mutation in a fetus as a noninvasive prenatal diagnosis of β-thalassemia. Genomic DNAs were prepared from 50 β-thalassemia minor couples whose pregnancy was at risk for homozygous β-thalassemia. Ten milliliters of the maternal blood from each pregnant woman were collected and after separating plasma stored at -80 °C until analysis. The extracted DNAs were analyzed by HRM real-time PCR for detection of IVS-II-I (G-A) as a paternally inherited mutation. The gold standard was the result of a chorionic villus sampling by a standard reverse dot blotting test. The sensitivity and specificity of HRM real-time PCR were 92.6% and 82.6%, respectively. Also, the positive and negative predictive values were 86.2% and 90.47%, respectively. HRM real-time PCR was a sensitive and specific method for determining the paternally inherited mutation in the fetus at risk with thalassemia major.

Comparison of bronchoalveolar lavage cytology and transbronchial biopsy in the diagnosis of carcinoma of lung.

PubMed

Ahmed, Ayesha; Ahmed, Sajjad

2004-01-01

The objectives of this study were to compare bronchoalveolar lavage (BAL) cytology and transbronchial biopsy in the diagnosis of carcinoma lung and to determine accuracy of BAL cytology using histopathlologic examination of transbronchial biopsy as gold standard at our center. This study was carried out at Department of Histopathology, Ayub Medical College, Abbottabad, from 1.09.2000 to 28.02.2003. BAL fluid and bronchial biopsy were received and processed simultaneously. Four cytology and a set of histopathology slides were prepared. These were screened and diagnosis recorded. Sensitivity, Specificity, False Positive, False Negative, Positive predictive value and Negative predictive value of BAL cytology were determined using histopathology of transbronchial biopsy as gold standard. We found the sensitivity of BAL cytology to be 93.44% as compared with transbronchial biopsy. The specificity was 100%. There was no false positive while false negative results were 6.55 %. The positive predictive value was 100 %, while the negative predictive value was 75 %. The overall diagnostic efficacy of BAL cytology was 94.52 %. BAL cytology is a highly sensitive and specific test for diagnosis of carcinoma lung. It can be used as a quick and reliable diagnostic method for diagnosis of lung malignancy.

EXHALED CARBON MONOXIDE LEVELS AMONG TOBACCO SMOKERS BY AGE.

PubMed

Chatrchaiwiwatana, Supaporn; Ratanasiri, Amornrat

2017-03-01

Measurement of exhaled carbon monoxide (ECO) has been used to confirm self-reported tobacco smoking. There is little data regarding ECO levels among Thai tobacco smokers by age. The objectives of this study were to determine ECO cutoff level to confirm tobacco smoking and to assess whether the cutoff level varies by age. During 2009 we evaluated 875 Thai volunteers aged 16-70 years, residing in Pathum Thani (central Thailand) and Khon Kaen (northeastern Thailand). Among the 875 volunteers, there were 584 non-smokers and 291 smokers. Each subject was interviewed and had their ECO level measured. The mean ECO level was 11.24 ppm among smokers and 2.25 ppm among non-smokers. The best ECO cutoff level to distinguish 291smokers from 584 non-smokers was 5 ppm (sensitivity 79.0%, specificity 89.9%).The optimal ECO cutoff level varied by age-group. For subjects aged 16-25 years, the best ECO cutoff level was 4 ppm (sensitivity 85.2%, specificity 77.5%) and for subject aged 26-70 years, the best ECO cutoff level was 5 ppm (sensitivity 79.4%, specificity 91.2%).These levels by age should be used among Thai subjects to determine smoking.

Antigen sensitivity is a major determinant of CD8+ T-cell polyfunctionality and HIV-suppressive activity

PubMed Central

Almeida, Jorge R.; Sauce, Delphine; Price, David A.; Papagno, Laura; Shin, So Youn; Moris, Arnaud; Larsen, Martin; Pancino, Gianfranco; Douek, Daniel C.; Autran, Brigitte; Sáez-Cirión, Asier

2009-01-01

CD8+ T cells are major players in the immune response against HIV. However, recent failures in the development of T cell–based vaccines against HIV-1 have emphasized the need to reassess our basic knowledge of T cell–mediated efficacy. CD8+ T cells from HIV-1–infected patients with slow disease progression exhibit potent polyfunctionality and HIV-suppressive activity, yet the factors that unify these properties are incompletely understood. We performed a detailed study of the interplay between T-cell functional attributes using a bank of HIV-specific CD8+ T-cell clones isolated in vitro; this approach enabled us to overcome inherent difficulties related to the in vivo heterogeneity of T-cell populations and address the underlying determinants that synthesize the qualities required for antiviral efficacy. Conclusions were supported by ex vivo analysis of HIV-specific CD8+ T cells from infected donors. We report that attributes of CD8+ T-cell efficacy against HIV are linked at the level of antigen sensitivity. Highly sensitive CD8+ T cells display polyfunctional profiles and potent HIV-suppressive activity. These data provide new insights into the mechanisms underlying CD8+ T-cell efficacy against HIV, and indicate that vaccine strategies should focus on the induction of HIV-specific T cells with high levels of antigen sensitivity to elicit potent antiviral efficacy. PMID:19389882

Antigen sensitivity is a major determinant of CD8+ T-cell polyfunctionality and HIV-suppressive activity.

PubMed

Almeida, Jorge R; Sauce, Delphine; Price, David A; Papagno, Laura; Shin, So Youn; Moris, Arnaud; Larsen, Martin; Pancino, Gianfranco; Douek, Daniel C; Autran, Brigitte; Sáez-Cirión, Asier; Appay, Victor

2009-06-18

CD8(+) T cells are major players in the immune response against HIV. However, recent failures in the development of T cell-based vaccines against HIV-1 have emphasized the need to reassess our basic knowledge of T cell-mediated efficacy. CD8(+) T cells from HIV-1-infected patients with slow disease progression exhibit potent polyfunctionality and HIV-suppressive activity, yet the factors that unify these properties are incompletely understood. We performed a detailed study of the interplay between T-cell functional attributes using a bank of HIV-specific CD8(+) T-cell clones isolated in vitro; this approach enabled us to overcome inherent difficulties related to the in vivo heterogeneity of T-cell populations and address the underlying determinants that synthesize the qualities required for antiviral efficacy. Conclusions were supported by ex vivo analysis of HIV-specific CD8(+) T cells from infected donors. We report that attributes of CD8(+) T-cell efficacy against HIV are linked at the level of antigen sensitivity. Highly sensitive CD8(+) T cells display polyfunctional profiles and potent HIV-suppressive activity. These data provide new insights into the mechanisms underlying CD8(+) T-cell efficacy against HIV, and indicate that vaccine strategies should focus on the induction of HIV-specific T cells with high levels of antigen sensitivity to elicit potent antiviral efficacy.

SiMa Cells for a Serotype Specific and Sensitive Cell-Based Neutralization Test for Botulinum Toxin A and E.

PubMed

Bak, Nicola; Rajagopal, Shalini; Stickings, Paul; Sesardic, Dorothea

2017-07-20

Botulinum toxins (BoNTs), of which there are seven serotypes, are among the most potent neurotoxins, with serotypes A, B and E causing human botulism. Antitoxins form the first line of treatment for botulism, and functional, highly sensitive in vitro methods for toxin neutralization are needed to replace the current in vivo methods used for determination of antitoxin potency. In this preliminary proof of concept study, we report the development of a neutralization test using the neuroblastoma SiMa cell line. The assay is serotype specific for either BoNT/A or BoNT/E, which both cleave unique sequences on SNAP-25 within SiMa cells. The end point is simple immunodetection of cleaved SNAP-25 from cell lysates with antibodies detecting only the newly exposed sequence on SNAP-25. Neutralizing antibodies prevent the toxin-induced cleavage of SNAP-25. The toxin neutralization assay, with an EC50 of ~2 mIU/mL determined with a standardized reference antiserum, is more sensitive than the mouse bioassays. Relevance was demonstrated with commercial and experimental antitoxins targeting different functional domains, and of known in vivo neutralizing activities. This is the first report describing a simple, specific, in vitro cell-based assay for the detection of neutralizing antibodies against BoNT/A and BoNT/E with a sensitivity exceeding that of the mouse bioassay.

SiMa Cells for a Serotype Specific and Sensitive Cell-Based Neutralization Test for Botulinum Toxin A and E

PubMed Central

Bak, Nicola; Rajagopal, Shalini; Stickings, Paul; Sesardic, Dorothea

2017-01-01

Botulinum toxins (BoNTs), of which there are seven serotypes, are among the most potent neurotoxins, with serotypes A, B and E causing human botulism. Antitoxins form the first line of treatment for botulism, and functional, highly sensitive in vitro methods for toxin neutralization are needed to replace the current in vivo methods used for determination of antitoxin potency. In this preliminary proof of concept study, we report the development of a neutralization test using the neuroblastoma SiMa cell line. The assay is serotype specific for either BoNT/A or BoNT/E, which both cleave unique sequences on SNAP-25 within SiMa cells. The end point is simple immunodetection of cleaved SNAP-25 from cell lysates with antibodies detecting only the newly exposed sequence on SNAP-25. Neutralizing antibodies prevent the toxin-induced cleavage of SNAP-25. The toxin neutralization assay, with an EC50 of ~2 mIU/mL determined with a standardized reference antiserum, is more sensitive than the mouse bioassays. Relevance was demonstrated with commercial and experimental antitoxins targeting different functional domains, and of known in vivo neutralizing activities. This is the first report describing a simple, specific, in vitro cell-based assay for the detection of neutralizing antibodies against BoNT/A and BoNT/E with a sensitivity exceeding that of the mouse bioassay. PMID:28726719

Evaluation of Modified 2-Tiered Serodiagnostic Testing Algorithms for Early Lyme Disease

PubMed Central

Strle, Klemen; Nigrovic, Lise E.; Lantos, Paul M.; Lepore, Timothy J.; Damle, Nitin S.; Ferraro, Mary Jane; Steere, Allen C.

2017-01-01

Abstract Background. The conventional 2-tiered serologic testing protocol for Lyme disease (LD), an enzyme immunoassay (EIA) followed by immunoglobulin M and immunoglobulin G Western blots, performs well in late-stage LD but is insensitive in patients with erythema migrans (EM), the most common manifestation of the illness. Western blots are also complex, difficult to interpret, and relatively expensive. In an effort to improve test performance and simplify testing in early LD, we evaluated several modified 2-tiered testing (MTTT) protocols, which use 2 assays designed as first-tier tests sequentially, without the need of Western blots. Methods. The MTTT protocols included (1) a whole-cell sonicate (WCS) EIA followed by a C6 EIA; (2) a WCS EIA followed by a VlsE chemiluminescence immunoassay (CLIA); and (3) a variable major protein-like sequence, expressed (VlsE) CLIA followed by a C6 EIA. Sensitivity was determined using serum from 55 patients with erythema migrans; specificity was determined using serum from 50 patients with other illnesses and 1227 healthy subjects. Results. Sensitivity of the various MTTT protocols in patients with acute erythema migrans ranged from 36% (95% confidence interval [CI], 25%–50%) to 54% (95% CI, 42%–67%), compared with 25% (95% CI, 16%–38%) using the conventional protocol (P = .003–0.3). Among control subjects, the 3 MTTT protocols were similarly specific (99.3%–99.5%) compared with conventional 2-tiered testing (99.5% specificity; P = .6–1.0). Conclusions. Although there were minor differences in sensitivity and specificity among MTTT protocols, each provides comparable or greater sensitivity in acute EM, and similar specificity compared with conventional 2-tiered testing, obviating the need for Western blots. PMID:28329259

Accommodative Lag by Autorefraction and Two Dynamic Retinoscopy Methods

PubMed Central

2008-01-01

Purpose To evaluate two clinical procedures, MEM and Nott retinoscopy, for detecting accommodative lags 1.00 diopter (D) or greater in children as identified by an open-field autorefractor. Methods 168 children 8 to <12 years old with low myopia, normal visual acuity, and no strabismus participated as part of an ancillary study within the screening process for a randomized trial. Accommodative response to a 3.00 D demand was first assessed by MEM and Nott retinoscopy, viewing binocularly with spherocylindrical refractive error corrected, with testing order randomized and each performed by a different masked examiner. The response was then determined viewing monocularly with spherical equivalent refractive error corrected, using an open-field autorefractor, which was the gold standard used for eligibility for the clinical trial. Sensitivity and specificity for accommodative lags of 1.00 D or more were calculated for each retinoscopy method compared to the autorefractor. Results 116 (69%) of the 168 children had accommodative lag of 1.00 D or more by autorefraction. MEM identified 66 children identified by autorefraction for a sensitivity of 57% (95% CI = 47% to 66%) and a specificity of 63% (95% CI = 49% to 76%). Nott retinoscopy identified 35 children for a sensitivity of 30% (95% CI = 22% to 39%) and a specificity of 81% (95% CI = 67% to 90%). Analysis of receiver operating characteristic (ROC) curves constructed for MEM and for Nott retinoscopy failed to reveal alternate cut points that would improve the combination of sensitivity and specificity for identifying accommodative lag ≥ 1.00 D as defined by autorefraction. Conclusions Neither MEM nor Nott retinoscopy provided adequate sensitivity and specificity to identify myopic children with accommodative lag ≥ 1.00 D as determined by autorefraction. A variety of methodological differences between the techniques may contribute to the modest to poor agreement. PMID:19214130

Repeat Cytology and Human Papillomavirus Screening Strategies in Detecting Preinvasive Cervical Lesions

PubMed Central

Li, Kemin; Yin, Rutie

2015-01-01

Abstract The aim of the present study was to determine the value of human papillomavirus (HPV) testing in screening patients with preinvasive cervical lesions. Seven hundred thirty-four women diagnosed with atypical squamous cells of undetermined significance (ASCUS+) cervical cytology during routine screening had additional cytologic testing and HPV DNA testing within 6 months of their diagnosis, after which all women who tested positive were referred for colposcopy and biopsy. The test findings were then used to determine the screening value of HPV for diagnosing preinvasive cervical lesions. Cytology and HPV testing were compared by conventional cytology. The odds ratio (OR) of sensitivity using ASCUS+ or low-grade squamous intraepithelial neoplasia (LSIL+) as a cutoff for detecting cervical intraepithelial neoplasia (CIN) II+ was, respectively, 0.78 (0.72, 0.85) and 0.82 (0.70, 0.95) (P < 0.01). The cytology for triage and conventional cytology had different sensitivities using ASCUS+ or LSIL+ as the cutoff (P < 0.01). The cytology or HPV testing and conventional cytology had a difference in sensitivity using ASCUS+, LSIL+, or high-grade squamous intraepithelial neoplasia (HSIL+) as the cutoff (P < 0.01). Cytology and HPV testing were also compared with conventional cytology. The OR of specificity using ASCUS+ or LSIL+ as the cutoff for the detection of CIN II+ was 1.97 (1.68, 2.31) and 1.10 (1.02, 1.18), respectively (P < 0.01). The cytology for triage and conventional cytology had a difference in specificity when ASCUS+ or LSIL+ was used as the cutoff (P < 0.01). Finally, the cytology or HPV testing and conventional cytology had a difference in specificity when ASCUS+, LSIL+, or HSIL+ was used as the cutoff (P < 0.01). Cytology and HPV testing and cytology for triage improved the specificity of detecting CIN II+, but this did not improve the sensitivity. Additionally, cytology or HPV testing improved the sensitivity of detecting CIN II+ but not the specificity. PMID:25654377

Reliability of meat, fish, dairy, and egg intake over a 33-year interval in Adventist Health Study 2.

PubMed

Singh, Pramil N; Batech, Michael; Faed, Pegah; Jaceldo-Siegl, Karen; Martins, Marcia; Fraser, Gary E

2014-01-01

We studied Adventist Health Study 2 (AHS-2) cohort members to determine the reliability of long-term recall of adult dietary intake that occurred 33 years ago. Establishing the reliability of these measures supports studies of how dietary exposure across the life course affects risk of cancer and other noncommunicable disease outcomes. Among 1816 AHS-2 cohort members, we conducted a statistical comparison of long-term recall of meat, fish, dairy, and eggs at AHS-2 baseline with their report of current diet 33 years before AHS-2 baseline at an age of 30-60 years. Major findings are as follows: 1) a high correlation for frequency of red meat (R = 0.71), poultry (R = 0.67), and fish (R = 0.60); lower correlations for dairy (R = 0.19) and eggs (R = 0.28); 2) good concordance for dichotomous measures of red meat [sensitivity: 0.70; specificity: 0.92; positive predictive value (PPV): 0.91], poultry (sensitivity: 0.76; specificity: 0.87; PPV: 0.83), fish (sensitivity: 0.61; specificity: 0.93; PPV: 0.89), dairy (sensitivity: 0.95; specificity: 0.57; PPV: 0.99), and eggs (sensitivity: 0.95; specificity: 0.41; PPV: 0.96); negative predictive value for dairy and eggs was poor. Among older AHS-2 cohort members, we found good reliability of recall of red meat, poultry, and fish intake that occurred 33 years earlier.

Optical Coherence Tomography Angiography versus Dye Angiography in Age-Related Macular Degeneration: Sensitivity and Specificity Analysis.

PubMed

Nikolopoulou, Eleni; Lorusso, Massimo; Micelli Ferrari, Luisa; Cicinelli, Maria Vittoria; Bandello, Francesco; Querques, Giuseppe; Micelli Ferrari, Tommaso

2018-01-01

Optical coherence tomography angiography (OCTA) could be a valid tool to detect choroidal neovascularization (CNV) in neovascular age-related macular degeneration (nAMD), allowing the analysis of the type, the morphology, and the extension of CNV in most of the cases. To determine the sensitivity and specificity of OCTA in detecting CNV secondary to nAMD, compared to fluorescein angiography (FA) and indocyanine green angiography (ICGA). Prospective observational study. Patients with suspected nAMD were recruited between May and December 2016. Patients underwent FA, ICGA, spectral domain OCT, and OCTA (AngioVue, Optovue, Inc.). Sensitivity and specificity of FA, with or without ICGA, were assessed and compared with OCTA. Seventy eyes of 70 consecutive patients were included: 32 eyes (45.7%) with type I CNV, 8 eyes (11.4%) with type II CNV, 4 eyes (5.7%) with type III CNV, 6 eyes (8.6%) with mixed type I and type II CNV, and 20 eyes (28.6%) with no CNV. Sensitivity of OCTA was 88% and specificity was 90%. Concordance between FA/ICGA and OCTA was very good (0,91; range 0,81-1,00). OCTA showed high sensitivity and specificity for detection of CNV. Concordance between OCTA and gold-standard dye-based techniques was excellent. OCTA may represent a first-line noninvasive method for the diagnosis of nAMD.

Developmental link between sex and nutrition; doublesex regulates sex-specific mandible growth via juvenile hormone signaling in stag beetles.

PubMed

Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J; Lavine, Laura C; Miura, Toru

2014-01-01

Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the developmental fates and final sizes of nutrition-dependent secondary-sexual characters.

Developmental Link between Sex and Nutrition; doublesex Regulates Sex-Specific Mandible Growth via Juvenile Hormone Signaling in Stag Beetles

PubMed Central

Gotoh, Hiroki; Miyakawa, Hitoshi; Ishikawa, Asano; Ishikawa, Yuki; Sugime, Yasuhiro; Emlen, Douglas J.; Lavine, Laura C.; Miura, Toru

2014-01-01

Sexual dimorphisms in trait expression are widespread among animals and are especially pronounced in ornaments and weapons of sexual selection, which can attain exaggerated sizes. Expression of exaggerated traits is usually male-specific and nutrition sensitive. Consequently, the developmental mechanisms generating sexually dimorphic growth and nutrition-dependent phenotypic plasticity are each likely to regulate the expression of extreme structures. Yet we know little about how either of these mechanisms work, much less how they might interact with each other. We investigated the developmental mechanisms of sex-specific mandible growth in the stag beetle Cyclommatus metallifer, focusing on doublesex gene function and its interaction with juvenile hormone (JH) signaling. doublesex genes encode transcription factors that orchestrate male and female specific trait development, and JH acts as a mediator between nutrition and mandible growth. We found that the Cmdsx gene regulates sex differentiation in the stag beetle. Knockdown of Cmdsx by RNA-interference in both males and females produced intersex phenotypes, indicating a role for Cmdsx in sex-specific trait growth. By combining knockdown of Cmdsx with JH treatment, we showed that female-specific splice variants of Cmdsx contribute to the insensitivity of female mandibles to JH: knockdown of Cmdsx reversed this pattern, so that mandibles in knockdown females were stimulated to grow by JH treatment. In contrast, mandibles in knockdown males retained some sensitivity to JH, though mandibles in these individuals did not attain the full sizes of wild type males. We suggest that moderate JH sensitivity of mandibular cells may be the default developmental state for both sexes, with sex-specific Dsx protein decreasing sensitivity in females, and increasing it in males. This study is the first to demonstrate a causal link between the sex determination and JH signaling pathways, which clearly interact to determine the developmental fates and final sizes of nutrition-dependent secondary-sexual characters. PMID:24453990

Prospective treatment plan-specific action limits for real-time intrafractional monitoring in surface image guided radiosurgery.

PubMed

Yock, Adam D; Pawlicki, Todd; Kim, Gwe-Ya

2016-07-01

In surface image guided radiosurgery, action limits are created to determine at what point intrafractional motion exhibited by the patient is large enough to warrant intervention. Action limit values remain constant across patients despite the fact that patient motion affects the target coverage of brain metastases differently depending on the planning technique and other treatment plan-specific factors. The purpose of this work was twofold. The first purpose was to characterize the sensitivity of single-met per iso and multimet per iso treatment plans to uncorrected patient motion. The second purpose was to describe a method to prospectively determine treatment plan-specific action limits considering this sensitivity. In their surface image guided radiosurgery technique, patient positioning is achieved with a thermoplastic mask that does not cover the patient's face. The patient's exposed face is imaged by a stereoscopic photogrammetry system. It is then compared to a reference surface and monitored throughout treatment. Seventy-two brain metastases (representing 29 patients) were used for this study. Twenty-five mets were treated individually ("single-met per iso plans"), and 47 were treated in a plan simultaneously with at least one other met ("multimet per iso plans"). For each met, the proportion of the gross tumor volume that remained within the 100% prescription isodose line was estimated under the influence of combinations of translations and rotations (0.0-3.0 mm and 0.0°-3.0°, respectively). The target volume and the prescription dose-volume were considered concentric spheres that each encompassed a volume determined from the treatment plan. Plan-specific contour plots and DVHs were created to illustrate the sensitivity of a specific lesion to uncorrected patient motion. Both single-met per iso and multimet per iso plans exhibited compromised target coverage under translations and rotations, though multimet per iso plans were considerably more sensitive to these transformations (2.3% and 39.8%, respectively). Plan-specific contour plots and DVHs were used to illustrate how size, distance from isocenter, and planning technique affect a particular met's sensitivity to motion. Stereotactic radiosurgery treatment plans that treat multiple brain metastases using a common isocenter are particularly susceptible to compromised target coverage as a result of uncorrected patient motion. The use of such a planning technique along with other treatment plan-specific factors should influence patient motion management. A graphical representation of the effect of translations and rotations on any particular plan can be generated to inform clinicians of the appropriate action limit when monitoring intrafractional motion.

Effectiveness of Quantitative Real Time PCR in Long-Term Follow-up of Chronic Myeloid Leukemia Patients.

PubMed

Savasoglu, Kaan; Payzin, Kadriye Bahriye; Ozdemirkiran, Fusun; Berber, Belgin

2015-08-01

To determine the use of the Quantitative Real Time PCR (RQ-PCR) assay follow-up with Chronic Myeloid Leukemia (CML) patients. Cross-sectional observational. Izmir Ataturk Education and Research Hospital, Izmir, Turkey, from 2009 to 2013. Cytogenetic, FISH, RQ-PCR test results from 177 CMLpatients' materials selected between 2009 - 2013 years was set up for comparison analysis. Statistical analysis was performed to compare between FISH, karyotype and RQ-PCR results of the patients. Karyotyping and FISH specificity and sensitivity rates determined by ROC analysis compared with RQ-PCR results. Chi-square test was used to compare test failure rates. Sensitivity and specificity values were determined for karyotyping 17.6 - 98% (p=0.118, p > 0.05) and for FISH 22.5 - 96% (p=0.064, p > 0.05) respectively. FISH sensitivity was slightly higher than karyotyping but there was calculated a strong correlation between them (p < 0.001). RQ-PCR test failure rate did not correlate with other two tests (p > 0.05); however, karyotyping and FISH test failure rate was statistically significant (p < 0.001). Besides, the situation needed for karyotype analysis, RQ-PCR assay can be used alone in the follow-up of CMLdisease.

[Validation of PCR as a tool for the detection of Leishmania (Vianna) spp. parasites in the Lutzomyia (Diptera: Psychodidae) vector].

PubMed

Santamaría, Erika; Ponce, Nubia; Puerta, Concepción; Ferro, Cristina

2005-06-01

The applicability of the polymerase chain reaction (PCR) was evaluated for the detection and identification of parasites in sand fly vectors and thereby precluding the necessity of dissecting them. DNA was extracted from individual, laboratory infected sand flies, and subjected to PCR amplification using specific B1 and B2 primers for parasites of the Leishmania (Viannia) subgenus. The sensitivity and specificity of the PCR primers were defined by means of serial dilutions of a Leishmania culture. Pooled samples of 1 to 5 sandflies were examined in association with the parasite dilutions to determine the point at which sensitivity became reduced. Experimentally infected sand flies were used to compare the sensitivity of the PCR with sand fly dissection and searching for flagellated parasites by microscopic examination. As few as a single parasite was detected, and the sensitivity remained unaltered up to 3 female sand flies per pool. Detection rates were 33% for the traditional technique and 33.3% for PCR. The B1 and B2 primers were confirmed as specific for Leishmania (Viannia) parasites. The demonstrably high sensitivity and specificity of PCR warrant the use of PCR in assessing natural infection rates of Leishmania (Viannia) in field populations of sand fly vectors.

Detecting High Hyperopia: The Plus Lens Test and the Spot Vision Screener.

PubMed

Feldman, Samuel; Peterseim, Mae Millicent W; Trivedi, Rupal H; Edward Wilson, M; Cheeseman, Edward W; Papa, Carrie E

2017-05-01

To evaluate the usefulness of the Plus Lens (Goodlite Company, Elgin, IL) test and the Spot Vision Screener (Welch Allyn, Skaneateles Falls, NY) in detecting high hyperopia in a pediatric population. Between June and August 2015, patients were screened with the Spot Vision Screener and the Plus Lens test prior to a scheduled pediatric ophthalmology visit. The following data were analyzed: demographic data, Plus Lens result, Spot Vision Screener result, cycloplegic refraction, and examination findings. Sensitivity/specificity and positive/negative predictive values were calculated for the Plus Lens test and Spot Vision Screener in detecting hyperopia as determined by the "gold-standard" cycloplegic refraction. A total of 109 children (average age: 82 months) were included. Compared to the ophthalmologist's cycloplegic refraction, the Spot Vision Screener sensitivity for +3.50 diopters (D) hyperopia was 31.25% and the specificity was 100%. The Plus Lens sensitivity for +3.50 D hyperopia was 43.75% and the specificity was 89.25%. Spot Vision Screener sensitivity increased with higher degrees of hyperopia. In this preliminary study, the Plus Lens test and the Spot Vision Screener demonstrated moderate sensitivity with good specificity in detecting high hyperopia. [J Pediatr Ophthalmol Strabismus. 2017;54(3):163-167.]. Copyright 2017, SLACK Incorporated.

Validity and Reliability of a Virtual Reality Game in Evaluating the Projected Frontal Plane Knee Angle When Landing From a Drop Vertical Jump.

PubMed

Mills, Kathryn; Idris, Aula; Pham, Thu-An; Porte, John; Wiggins, Mark; Kavakli, Manolya

2017-12-18

To determine the validity and reliability of the peak frontal plane knee angle evaluated by a virtual reality (VR) netball game when landing from a drop vertical jump (DVJ). Laboratory Methods: Forty participants performed 3 DVJs evaluated by 3-dimensional (3D) motion analysis and 3 DVJs evaluated by the VR game. Limits of agreement for the peak projected frontal plane knee angle and peak knee abduction were determined. Participants were given a consensus category of "Above threshold" or "Below threshold" based on a pre-specified threshold angle of 9˚ during landing. Classification agreement was determined using kappa coefficient and accuracy was determined using specificity and sensitivity. Ten participants returned 1-week later to determine intra-rater reliability, standard error of the measure and typical error. The mean difference in detected frontal plane knee angle was 3.39˚ (1.03˚, 5.74˚). Limits of agreement were -10.27˚ (-14.36˚, -6.19˚) to 17.05˚ (12.97˚, 21.14˚). Substantial agreement, specificity and sensitivity were observed for the threshold classification (ĸ = 0.66, [0.42, 0.88] specificity= 0.96 [0.78, 1.0], sensitivity= 0.75 [0.43, 0.95]). The game exhibited acceptable reliability over time (ICC (3,1) = 0.844) and error was approximately 2˚. The VR game reliably evaluated a projected frontal plane knee angle. While the knee angle detected by the VR game is strongly related peak knee abduction, the accuracy of detecting the exact angle was limited. A threshold approach may be a more accurate approach for gaming technology to evaluate frontal plane knee angles when landing from a jump.

Radiation treatment of pharmaceuticals

NASA Astrophysics Data System (ADS)

Dám, A. M.; Gazsó, L. G.; Kaewpila, S.; Maschek, I.

1996-03-01

Product specific doses were calculated for pharmaceuticals to be radiation treated. Radio-pasteurization dose were determined for some heat sensitive pharmaceutical basic materials (pancreaton, neopancreatin, neopancreatin USP, duodenum extract). Using the new recommendation (ISO standards, Method 1) dose calculations were performed and radiation sterilization doses were determined for aprotinine and heparine Na.

An improved colorimetric method for the determination of proline in the presence of other ninhydrin-positive compounds

PubMed Central

Wren, J. J.; Wiggall, P. H.

1965-01-01

1. The conditions required for sensitive and specific colorimetric determination of proline with acidified ninhydrin were investigated. 2. A method applicable to protein samples was developed. 3. The only compound found to interfere appreciably was a hydroxyproline. PMID:14342233

Detection of pericardial effusion by chest roentgenography and electrocardiography versus echocardiography.

PubMed Central

Manyari, D. E.; Milliken, J. A.; Colwell, B. T.; Burggraf, G. W.

1978-01-01

To determine the sensitivity and specificity of chest roentgenography and electrocardiography in the detection of pericardial effusion, echocardiography was used as the diagnostic standard. Chest roentgenograms and electrocardiograms of 124 patients, 57 of whom had pericardial effusion, were read without knowledge of the echocardiographic interpretation. The sensitivity of roentgenographic diagnosis was low (20%), as was that of diagnosis from decreased voltage on the electrocardiogram (26%). The specificity of the chest roentgenogram was 89% and that of the low-voltage electrocardiogram 97%. The high specificity of the low-voltage electrocardiogram may have been due in part to the exclusion of obese and emphysematous subjects from the study. When cardiomegaly detected roentgenographically or a low-voltage electrocardiogram or both were considered as evidence of pericardial effusion, sensitivity improved to 82% but specificity declined to 29%. It is concluded the chest roentgenography and electrocardiography are unsatisfactory as screening investigations for the detection of pericardial effusion. Images FIG. 1 FIG. 2 FIG. 3 PMID:688146

ADHD Diagnosis: As Simple As Administering a Questionnaire or a Complex Diagnostic Process?

PubMed

Parker, Ashton; Corkum, Penny

2016-06-01

The present study investigated the validity of using the Conners' Teacher and Parent Rating Scales (CTRS/CPRS) or semistructured diagnostic interviews (Parent Interview for Child Symptoms and Teacher Telephone Interview) to predict a best-practices clinical diagnosis of ADHD. A total of 279 children received a clinical diagnosis based on a best-practices comprehensive assessment (including diagnostic parent and teacher interviews, collection of historical information, rating scales, classroom observations, and a psychoeducational assessment) at a specialty ADHD Clinic in Truro, Nova Scotia, Canada. Sensitivity and specificity with clinical diagnosis were determined for the ratings scales and diagnostic interviews. Sensitivity and specificity values were high for the diagnostic interviews (91.8% and 70.7%, respectively). However, while sensitivity of the CTRS/CPRS was relatively high (83.5%), specificity was poor (35.7%). The low specificity of the CPRS/CTRS is not sufficient to be used alone to diagnose ADHD. (J. of Att. Dis. 2016; 20(6) 478-486). © The Author(s) 2013.

Correlation coefficients of three self-perceived orthodontic treatment need indices.

PubMed

Eslamipour, Faezeh; Riahi, Farnaz Tajmir; Etemadi, Milad; Riahi, Alireza

2017-01-01

To determine patient orthodontic treatment need, appropriate self-perceived indices are required. The aim of this study was to assess the sensitivity and specificity of esthetic component (AC) of the index of orthodontic treatment need (IOTN), oral esthetic subjective index scale (OASIS), and visual analog scale (VAS) through dental health component (DHC) IOTN as a normative index to determine the more appropriate self-perceived index among young adults. In this cross-sectional study, a sample of 993 was randomly selected from freshman students of Isfahan University. Those with a history of orthodontic treatment or current treatment were excluded. DHC was evaluated by two inter- and intra-calibrated examiners. Data for AC, OASIS, and VAS were collected through a questionnaire completed by students. Descriptive statistics, Mann-Whitney U-test, and Spearman correlation test, were used for data analyses. Sensitivity, specificity, positive and negative predictive values of self-perceived indices were calculated through DHC. Sensitivity of AC, OASIS, and VAS for evaluating definite orthodontic treatment need was calculated at 15.4%, 22.3%, and 44.6%, respectively. Specificity of these indices for evaluating definite orthodontic treatment need was calculated at 92.7%, 90.5%, and 76.2% percent, respectively. All self-perceived indices had a significant correlation with together and with DHC ( P < 0.01). Among demographic factors, there was weak but significant correlation only between mother's educational level and VAS ( P < 0.01). Due to the sensitivity and specificity of the three self-perceived indices, these indices are not recommended for population screening and should be used as adjuncts to a normative index for decision-making in orthodontic treatment planning.

Assessment of nasalance and nasality in patients with a repaired cleft palate.

PubMed

Sinko, Klaus; Gruber, Maike; Jagsch, Reinhold; Roesner, Imme; Baumann, Arnulf; Wutzl, Arno; Denk-Linnert, Doris-Maria

2017-07-01

In patients with a repaired cleft palate, nasality is typically diagnosed by speech language pathologists. In addition, there are various instruments to objectively diagnose nasalance. To explore the potential of nasalance measurements after cleft palate repair by NasalView ® , we correlated perceptual nasality and instrumentally measured nasalance of eight speech items and determined the relationship between sensitivity and specificity of the nasalance measures by receiver-operating characteristics (ROC) analyses and AUC (area under the curve) computation for each single test item and specific item groups. We recruited patients with a primarily repaired cleft palate receiving speech therapy during follow-up. During a single day visit, perceptive and instrumental assessments were obtained in 36 patients and analyzed. The individual perceptual nasality was assigned to one of four categories; the corresponding instrumental nasalance measures for the eight specific speech items were expressed on a metric scale (1-100). With reference to the perceptual diagnoses, we observed 3 nasal and one oral test item with high sensitivity. However, the specificity of the nasality indicating measures was rather low. The four best speech items with the highest sensitivity provided scores ranging from 96.43 to 100%, while the averaged sensitivity of all eight items was below 90%. We conclude that perceptive evaluation of nasality remains state of the art. For clinical follow-up, instrumental nasalance assessment can objectively document subtle changes by analysis of four speech items only. Further studies are warranted to determine the applicability of instrumental nasalance measures in the clinical routine, using discriminative items only.

Cyst fluid analysis in the differential diagnosis of pancreatic cystic lesions: a pooled analysis.

PubMed

van der Waaij, Laurens A; van Dullemen, Hendrik M; Porte, Robert J

2005-09-01

Pancreatic cystic tumors commonly include serous cystadenoma (SCA), mucinous cystadenoma (MCA), and mucinous cystadenocarcinoma (MCAC). A differential diagnosis with pseudocysts (PC) can be difficult. Radiologic criteria are not reliable. The objective of the study is to investigate the value of cyst fluid analysis in the differential diagnosis of benign (SCA, PC) vs. premalignant or malignant (MCA, MCAC) lesions. A search in PubMed was performed with the search terms cyst, pancrea, and fluid. Articles about cyst fluid analysis of pancreatic lesions that contained the individual data of at least 7 patients were included in the study. Data of all individual patients were combined and were plotted in scatter grams. Cutoff levels were determined. Twelve studies were included, which comprised data of 450 patients. Cysts with an amylase concentration <250 U/L were SCA, MCA, or MCAC (sensitivity 44%, specificity 98%) and, thus, virtually excluded PC. A carcinoembryonic antigen (CEA) <5 ng/mL suggested a SCA or PC (sensitivity 50%, specificity 95%). A CEA >800 ng/mL strongly suggested MCA or MCAC (sensitivity 48%, specificity 98%). A carbohydrate-associated antigen (CA) 19-9 <37 U/mL strongly suggested PC or SCA (sensitivity 19%, specificity 98%). Cytologic examination revealed malignant cells in 48% of MCAC (n = 111). Most pancreatic cystic tumors should be resected without the need for cyst fluid analysis. However, in asymptomatic patients, in patients with an increased surgical risk, and, in patients in whom there is a diagnostic uncertainty about the presence of a PC, cyst fluid analysis helps to determine the optimal therapeutic strategy.

Evaluation of abnormal radiological findings in children aged 2 to 36 months followed by recurrent urinary tract infection: a retrospective study.

PubMed

Ozen, Cinar; Ertan, Pelin; Aras, Feray; Gumuser, Gul; Ozkol, Mine; Horasan Dinc, Gonul

2017-11-01

Our aim is to determine the rational usage of imaging techniques in order to prevent or minimize permanent renal damage in recurrent urinary tract infections (UTIs). This study was enrolled children aged between 2 and 36 months, following-up with the diagnosis of recurrent UTI. All children had ultrasonography (USG) and dimercaptosuccinic acid scanning, 39 of them had underwent on voiding cystourethrography. There were 133 children (87 girls, 46 boys) with the mean age of 32.82 ± 38.10 months included into the study. Forty-three kidney units were normal in ultrasonogram of which seven units had reflux whereas among 35 units with hydronephrosis 22 units had reflux. Sensitivity and specificity presence of hydronephrosis in ultrasonogram for prediction of reflux was 75.9% and 73.5%, respectively. There were 19 dilated ureters in ultrasonogram, and among them 14 had reflux. Sensitivity and specificity of presence with ureteral dilatation in ultrasonogram for prediction of reflux was found as 48.3% and 89.8%, respectively. The sensitivity of parenchymal thinning seen in ultrasonogram for the evaluation of renal parenchyma was 15.9%, whereas specificity was 98.2% .Sensitivity and specificity of dimercaptosuccinic acid for prediction of reflux was 51.6% and 72.3%, respectively. The normal ultrasonogram findings cannot rule out neither possibility of reflux presence nor development of renal scarring. Therefore, DMSA scanning has major role both in determination of parenchymal damage and prevention of scarring. Also we get an important result as ureteral dilatation seen in USG, related to presence of reflux.

Development and face validity of a cerebral visual impairment motor questionnaire for children with cerebral palsy.

PubMed

Salavati, M; Waninge, A; Rameckers, E A A; van der Steen, J; Krijnen, W P; van der Schans, C P; Steenbergen, B

2017-01-01

The objectives of this study were (i) to develop two cerebral visual impairment motor questionnaires (CVI-MQ's) for children with cerebral palsy (CP): one for children with Gross Motor Function Classification System (GMFCS) levels I, II and III and one for children with GMFCS levels IV and V; (ii) to describe their face validity and usability; and (iii) to determine their sensitivity and specificity. The initial versions of the two CVI-MQ's were developed based on literature. Subsequently, the Delphi method was used in two groups of experts, one familiar with CVI and one not familiar with CVI, in order to gain consensus about face validity and usability. The sensitivity and specificity of the CVI-MQ's were subsequently assessed in 82 children with CP with (n = 39) and without CVI (n = 43). With the receiver operating curve the cut-off scores were determined to detect possible presence or absence of CVI in children with CP. Both questionnaires showed very good face validity (percentage agreement above 96%) and good usability (percentage agreement 95%) for practical use. The CVI-MQ version for GMFCS levels I, II and III had a sensitivity of 1.00 and specificity of 0.96, with a cut-off score of 12 points or higher, and the version for GMFCS levels IV and V had a sensitivity of 0.97 and a specificity of 0.98, with a cut-off score of eight points or higher. The CVI-MQ is able to identify at-risk children with CP for the probability of having CVI. © 2016 John Wiley & Sons Ltd.

Sensitivity and specificity of western blot testing of cerebrospinal fluid and serum for diagnosis of equine protozoal myeloencephalitis in horses with and without neurologic abnormalities.

PubMed

Daft, Barbara M; Barr, Bradd C; Gardner, Ian A; Read, Deryck; Bell, William; Peyser, Karen G; Ardans, Alex; Kinde, Hailu; Morrow, Jennifer K

2002-10-01

To determine sensitivity and specificity of western blot testing (WBT) of CSF and serum for diagnosis of equine protozoal myeloencephalitis (EPM) in horses with and without neurologic abnormalities. Prospective investigation. 65 horses with and 169 horses without neurologic abnormalities. CSF and serum from horses submitted for necropsy were tested for Sarcocystis neurona-specific antibody with a WBT. Results of postmortem examination were used as the gold standard against which results of the WBT were compared. Sensitivity of WBT of CSF was 87% for horses with and 88% for horses without neurologic abnormalities. Specificity of WBT of CSF was 44% for horses with and 60% for horses without neurologic abnormalities. Regardless of whether horses did or did not have neurologic abnormalities, sensitivity and specificity of WBT of serum were not significantly different from values for WBT of CSF. Ninety-four horses without EPM had histologic evidence of slight CNS inflammation. The low specificity of WBT of CSF indicated that it is inappropriate to diagnose EPM on the basis of a positive test result alone because of the possibility of false-positive test results. The high sensitivity, however, means that a negative result is useful in ruling out EPM. There was no advantage in testing CSF versus serum in horses without neurologic abnormalities. Slight CNS inflammation was common in horses with and without S neurona-specific antibodies in the CSF and should not be considered an indication of CNS infection with S neurona.

Investigation of carbon storage regulation network (csr genes) and phenotypic differences between acid sensitive and resistant Escherichia coli O157:H7 strains

USDA-ARS?s Scientific Manuscript database

Background: Escherichia coli O157:H7 and related serotype strains have previously been shown to vary in acid resistance, however, little is known about strain specific mechanisms of acid resistance. We examined sensitive and resistant E. coli strains to determine the effects of growth in minimal and...

A Meta-Analytic Review of the Role of Child Anxiety Sensitivity in Child Anxiety

ERIC Educational Resources Information Center

Noel, Valerie A.; Francis, Sarah E.

2011-01-01

Conflicting findings exist regarding (1) whether anxiety sensitivity (AS) is a construct distinct from anxiety in children and (2) the specific nature of the role of AS in child anxiety. This study uses meta-analytic techniques to (1) determine whether youth (ages 6-18 years) have been reported to experience AS, (2) examine whether AS…

Excessive Eating and Compulsive Buying Behaviours in Women: An Empirical Pilot Study Examining Reward Sensitivity, Anxiety, Impulsivity, Self-Esteem and Social Desirability

ERIC Educational Resources Information Center

Davenport, Kate; Houston, James E.; Griffiths, Mark D.

2012-01-01

"Mall disorders" such as excessive eating and compulsive buying appear to be increasing, particularly among women. A battery of questionnaires was used in an attempt to determine this association between specific personality traits (i.e., reward sensitivity, impulsivity, cognitive and somatic anxiety, self-esteem, and social desirability) and…

The First Time Ever I Saw Your Feet: Inversion Effect in Newborns' Sensitivity to Biological Motion

ERIC Educational Resources Information Center

Bardi, Lara; Regolin, Lucia; Simion, Francesca

2014-01-01

Inversion effect in biological motion perception has been recently attributed to an innate sensitivity of the visual system to the gravity-dependent dynamic of the motion. However, the specific cues that determine the inversion effect in naïve subjects were never investigated. In the present study, we have assessed the contribution of the local…

Subjective evaluation of physical and mental workload interactions across different muscle groups.

PubMed

Mehta, Ranjana K; Agnew, Michael J

2015-01-01

Both physical and mental demands, and their interactions, have been shown to increase biomechanical loading and physiological reactivity as well as impair task performance. Because these interactions have shown to be muscle-dependent, the aim of this study was to determine the sensitivity of the NASA Task Load Index (NASA TLX) and Ratings of Perceived Exertion (RPE) to evaluate physical and mental workload during muscle-specific tasks. Twenty-four participants performed upper extremity and low back exertions at three physical workload levels in the absence and presence of a mental stressor. Outcome measures included RPE and NASA TLX (six sub-scales) ratings. The findings indicate that while both RPEs and NASA TLX ratings were sensitive to muscle-specific changes in physical demand, only an additional mental stressor and its interaction with either physical demand or muscle groups influenced the effort sub-scale and overall workload scores of the NASA TLX. While additional investigations in actual work settings are warranted, the NASA TLX shows promise in evaluating perceived workload that is sensitive not only to physical and mental demands but also sensitive in determining workload for tasks that employ different muscle groups.

Vertical or horizontal orientation of foot radiographs does not affect image interpretation

PubMed Central

Ferran, Nicholas Antonio; Ball, Luke; Maffulli, Nicola

2012-01-01

Summary This study determined whether the orientation of dorsoplantar and oblique foot radiographs has an effect on radiograph interpretation. A test set of 50 consecutive foot radiographs were selected (25 with fractures, and 25 normal), and duplicated in the horizontal orientation. The images were randomly arranged, numbered 1 through 100, and analysed by six image interpreters. Vertical and horizontal area under the ROC curve, accuracy, sensitivity and specificity were calculated for each image interpreter. There was no significant difference in the area under the ROC curve, accuracy, sensitivity or specificity of image interpretation between images viewed in the vertical or horizontal orientation. While conventions for display of radiographs may help to improve the development of an efficient visual search strategy in trainees, and allow for standardisation of publication of radiographic images, variation from the convention in clinical practice does not appear to affect the sensitivity or specificity of image interpretation. PMID:23738310

Evaluation of puberty by verifying spontaneous and stimulated gonadotropin values in girls.

PubMed

Chin, Vivian L; Cai, Ziyong; Lam, Leslie; Shah, Bina; Zhou, Ping

2015-03-01

Changes in pharmacological agents and advancements in laboratory assays have changed the gonadotropin-releasing hormone analog stimulation test. To determine the best predictive model for detecting puberty in girls. Thirty-five girls, aged 2 years 7 months to 9 years 3 months, with central precocious puberty (CPP) (n=20) or premature thelarche/premature adrenarche (n=15). Diagnoses were based on clinical information, baseline hormones, bone age, and pelvic sonogram. Gonadotropins and E2 were analyzed using immunochemiluminometric assay. Logistic regression for CPP was performed. The best predictor of CPP is the E2-change model based on 3- to 24-h values, providing 80% sensitivity and 87% specificity. Three-hour luteinizing hormone (LH) provided 75% sensitivity and 87% specificity. Basal LH lowered sensitivity to 65% and specificity to 53%. The E2-change model provided the best predictive power; however, 3-h LH was more practical and convenient when evaluating puberty in girls.

[Transcutaneous electrical nervous stimulation in the prognosis of Bell's palsy].

PubMed

Sabag-Ruiz, Enrique; Osuna-Bernal, Janeth; Brito-Zurita, Olga Rosa; Gómez-Alcalá, Alejandro Vidal; Ornelas-Aguirre, José Manuel

2009-01-01

The peripheral face palsy (PFP) is the commonest acute cranial neuropathy. The PFP has a showy clinical pattern which contrasts with a favorable course. Our objective was to determine the sensitivity and specificity for the nervous excitability test (NET) with transcutaneous electrical nerve stimulation (TENS) and the time required to obtain face symmetry. An analytical cross-sectional study was made in 22 patients with PFP. The goal was the time (days) to obtain face symmetry. The sensitivity and specificity was carried out. A sensitivity and specificity of the NET was of 100 %. The correlation corrected by sex and age between both variables was 0.89. The average in days of recovery was smaller in those with a positive NET (p < 0.05) test. The test of nervous excitability for PFP with TENS is safe and simple to use in primary care and urgencies services.

Development of a highly sensitive and specific immunoassay for enrofloxacin based on heterologous coating haptens.

PubMed

Wang, Zhanhui; Zhang, Huiyan; Ni, Hengjia; Zhang, Suxia; Shen, Jianzhong

2014-04-11

In the paper, an enzyme-linked immunosorbent immunoassay (ELISA) for detection of enrofloxacin was described using one new derivative of enrofloxacin as coating hapten, resulting in surprisingly high sensitivity and specificity. Incorporation of aminobutyric acid (AA) in the new derivative of enrofloxacin had decreased the IC50 of the ELISA for enrofloxacin from 1.3 μg L(-1) to as low as 0.07 μg L(-1). The assay showed neglect cross-reactivity for other fluoroquinolones but ofloxacin (8.23%), marbofloxacin (8.97%) and pefloxacin (7.29%). Analysis of enrofloxacin fortified chicken muscle showed average recoveries from 81 to 115%. The high sensitivity and specificity of the assay makes it a suitable screening method for the determination of low levels of enrofloxacin in chicken muscle without clean-up step. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of Commercially Available Diagnostic Tests for the Detection of Dengue Virus NS1 Antigen and Anti-Dengue Virus IgM Antibody

PubMed Central

Hunsperger, Elizabeth A.; Yoksan, Sutee; Buchy, Philippe; Nguyen, Vinh Chau; Sekaran, Shamala Devi; Enria, Delia A.; Vazquez, Susana; Cartozian, Elizabeth; Pelegrino, Jose L.; Artsob, Harvey; Guzman, Maria G.; Olliaro, Piero; Zwang, Julien; Guillerm, Martine; Kliks, Susie; Halstead, Scott; Peeling, Rosanna W.; Margolis, Harold S.

2014-01-01

Commercially available diagnostic test kits for detection of dengue virus (DENV) non-structural protein 1 (NS1) and anti-DENV IgM were evaluated for their sensitivity and specificity and other performance characteristics by a diagnostic laboratory network developed by World Health Organization (WHO), the UNICEF/UNDP/World Bank/WHO Special Programme for Research and Training in Tropical Diseases (TDR) and the Pediatric Dengue Vaccine Initiative (PDVI). Each network laboratory contributed characterized serum specimens for the panels used in the evaluation. Microplate enzyme-linked immunosorbent assay (ELISA) and rapid diagnostic test (RDT formats) were represented by the kits. Each ELISA was evaluated by 2 laboratories and RDTs were evaluated by at least 3 laboratories. The reference tests for IgM anti-DENV were laboratory developed assays produced by the Armed Forces Research Institute for Medical Science (AFRIMS) and the Centers for Disease Control and Prevention (CDC), and the NS1 reference test was reverse transcriptase polymerase chain reaction (RT-PCR). Results were analyzed to determine sensitivity, specificity, inter-laboratory and inter-reader agreement, lot-to-lot variation and ease-of-use. NS1 ELISA sensitivity was 60–75% and specificity 71–80%; NS1 RDT sensitivity was 38–71% and specificity 76–80%; the IgM anti-DENV RDTs sensitivity was 30–96%, with a specificity of 86–92%, and IgM anti-DENV ELISA sensitivity was 96–98% and specificity 78–91%. NS1 tests were generally more sensitive in specimens from the acute phase of dengue and in primary DENV infection, whereas IgM anti-DENV tests were less sensitive in secondary DENV infections. The reproducibility of the NS1 RDTs ranged from 92-99% and the IgM anti-DENV RDTs from 88–94%. PMID:25330157

Use of Humanized RS-ATL8 Reporter System for Detection of Allergen-Specific IgE Sensitization in Human Food Allergy.

PubMed

Ali, Eman Ali; Nakamura, Ryosuke; Falcone, Franco H

2017-01-01

Allergen-specific Immunoglobulin E (IgE) determination lies at the heart of diagnosis of sensitization to food and other allergens. In the past few years, reporter systems capable of detecting the presence of allergen-specific IgE have been developed by several labs. These rely on humanized rat basophil leukemia cell lines stably transfected with reporter genes such as firefly luciferase. In this chapter, we describe protocols for the use of the RS-ATL8 cell line (IgE cross-linking-induced luciferase expression; EXiLE) in 96-well and 384-well formats. We also describe optional treatment steps for enveloped virus and complement inactivation.

Utilizing the ultrasensitive Schistosoma up-converting phosphor lateral flow circulating anodic antigen (UCP-LF CAA) assay for sample pooling-strategies.

PubMed

Corstjens, Paul L A M; Hoekstra, Pytsje T; de Dood, Claudia J; van Dam, Govert J

2017-11-01

Methodological applications of the high sensitivity genus-specific Schistosoma CAA strip test, allowing detection of single worm active infections (ultimate sensitivity), are discussed for efficient utilization in sample pooling strategies. Besides relevant cost reduction, pooling of samples rather than individual testing can provide valuable data for large scale mapping, surveillance, and monitoring. The laboratory-based CAA strip test utilizes luminescent quantitative up-converting phosphor (UCP) reporter particles and a rapid user-friendly lateral flow (LF) assay format. The test includes a sample preparation step that permits virtually unlimited sample concentration with urine, reaching ultimate sensitivity (single worm detection) at 100% specificity. This facilitates testing large urine pools from many individuals with minimal loss of sensitivity and specificity. The test determines the average CAA level of the individuals in the pool thus indicating overall worm burden and prevalence. When requiring test results at the individual level, smaller pools need to be analysed with the pool-size based on expected prevalence or when unknown, on the average CAA level of a larger group; CAA negative pools do not require individual test results and thus reduce the number of tests. Straightforward pooling strategies indicate that at sub-population level the CAA strip test is an efficient assay for general mapping, identification of hotspots, determination of stratified infection levels, and accurate monitoring of mass drug administrations (MDA). At the individual level, the number of tests can be reduced i.e. in low endemic settings as the pool size can be increased as opposed to prevalence decrease. At the sub-population level, average CAA concentrations determined in urine pools can be an appropriate measure indicating worm burden. Pooling strategies allowing this type of large scale testing are feasible with the various CAA strip test formats and do not affect sensitivity and specificity. It allows cost efficient stratified testing and monitoring of worm burden at the sub-population level, ideally for large-scale surveillance generating hard data for performance of MDA programs and strategic planning when moving towards transmission-stop and elimination.

Penetrating Colorectal Injuries: Diagnostic Performance of Multidetector CT with Trajectography.

PubMed

Dreizin, David; Boscak, Alexis R; Anstadt, Michael J; Tirada, Nikki; Chiu, William C; Munera, Felipe; Bodanapally, Uttam K; Hornick, Michael; Stein, Deborah M

2016-12-01

Purpose To determine the diagnostic performance of multidetector computed tomography (CT) with trajectography for penetrating colorectal injuries. Materials and Methods This institutional review board-approved and HIPAA-compliant study was a 6-year blinded retrospective review by two independent readers of 182 consecutive patients who preoperatively underwent 40- or 64-row multidetector CT for penetrating torso trauma below the diaphragm and had surgically confirmed findings. Colorectal perforation was present in 42 patients. Trajectory analysis with postprocessing software was used for all studies. Additional signs evaluated were rectal contrast agent leak, collections of extruded fecal material, mural defect, wall thickening, abnormal enhancement, free fluid or stranding, and free air. The quality of the colorectal contrast agent administration was recorded. Sensitivity, specificity, predictive values, areas under the receiver operating characteristic curves (AUCs), and Cohen κ were determined. Results In patients with rectal contrast agent administration (n = 151), AUCs were 0.90-0.91, which indicated excellent accuracy. Trajectory was sensitive (88%-91%). For single wounds (n = 104), sensitivity of trajectory was 96% for both readers, but was only 80% for multiple wounds (n = 47). Contrast agent leak was highly specific (96%-98%), but insensitive (42%-46%). Improved diagnostic performance was observed in patients with poor colonic distension or opacification. Accuracy remained high (AUC, 0.86-0.99) in the group without rectal contrast agent administration (n = 31). Conclusion Trajectory had excellent sensitivity, while rectal contrast agent leak was specific but insensitive. Sensitivity of trajectory was lower for multiple wounds. Accuracy remained high in patients without rectal contrast agent administration. © RSNA, 2016.

[Validation of the Montgomery-Åsberg Depression Rating Scale (MADRS) in Colombia].

PubMed

Cano, Juan Fernando; Gomez Restrepo, Carlos; Rondón, Martín

2016-01-01

To adapt and to validate the Montgomery-Åsberg Depression Rating Scale (MADRS) in Colombia. Observational study for scale validation. Validity criteria were used to determine the severity cut-off points of the tool. Taking into account sensitivity and specificity values, those cut points were contrasted with ICD-10 criteria for depression severity. A a factor analysis was performed. The internal consistencY was determined with the same sample of patients used for the validity criteria. Inter-rater reliability was assessed by evaluating the 22 records of the patients that consented to a video interview. Sensitivity to change was established through a second application of the scale in 28 subjects after a lapse of 14 to 28 days. The study was performed in Bogotá, the tool was applied in 150 patients suffering from major depressive disorder. The cut-off point for moderate depression was 20 (sensitivity, 98%; specificity, 96%), and the cut-off point for severe depression was 34 (sensitivity, 98%; specificity, 92%). The tool appears as a unidimensional scale, which possesses a good internal consistency with (α=.9168). The findings of inter-rater reliability evaluation showed the scale as highly reliable (intraclass correlation coefficient=.9833). The instrument has a good sensitivity to change. The Colombian version of the Montgomery-Åsberg Depression Rating Scale has good psychometric properties and can be used in clinical practice and in clinical research in the field of depressive disorder. Copyright © 2015 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

Performance of the dipstick screening test as a predictor of negative urine culture

PubMed Central

Marques, Alexandre Gimenes; Doi, André Mario; Pasternak, Jacyr; Damascena, Márcio dos Santos; França, Carolina Nunes; Martino, Marinês Dalla Valle

2017-01-01

ABSTRACT Objective To investigate whether the urine dipstick screening test can be used to predict urine culture results. Methods A retrospective study conducted between January and December 2014 based on data from 8,587 patients with a medical order for urine dipstick test, urine sediment analysis and urine culture. Sensitivity, specificity, positive and negative predictive values were determined and ROC curve analysis was performed. Results The percentage of positive cultures was 17.5%. Nitrite had 28% sensitivity and 99% specificity, with positive and negative predictive values of 89% and 87%, respectively. Leukocyte esterase had 79% sensitivity and 84% specificity, with positive and negative predictive values of 51% and 95%, respectively. The combination of positive nitrite or positive leukocyte esterase tests had 85% sensitivity and 84% specificity, with positive and negative predictive values of 53% and 96%, respectively. Positive urinary sediment (more than ten leukocytes per microliter) had 92% sensitivity and 71% specificity, with positive and negative predictive values of 40% and 98%, respectively. The combination of nitrite positive test and positive urinary sediment had 82% sensitivity and 99% specificity, with positive and negative predictive values of 91% and 98%, respectively. The combination of nitrite or leukocyte esterase positive tests and positive urinary sediment had the highest sensitivity (94%) and specificity (84%), with positive and negative predictive values of 58% and 99%, respectively. Based on ROC curve analysis, the best indicator of positive urine culture was the combination of positives leukocyte esterase or nitrite tests and positive urinary sediment, followed by positives leukocyte and nitrite tests, positive urinary sediment alone, positive leukocyte esterase test alone, positive nitrite test alone and finally association of positives nitrite and urinary sediment (AUC: 0.845, 0.844, 0.817, 0.814, 0.635 and 0.626, respectively). Conclusion A negative urine culture can be predicted by negative dipstick test results. Therefore, this test may be a reliable predictor of negative urine culture. PMID:28444086

Sensitivity and specificity of dosing alerts for dosing errors among hospitalized pediatric patients

PubMed Central

Stultz, Jeremy S; Porter, Kyle; Nahata, Milap C

2014-01-01

Objectives To determine the sensitivity and specificity of a dosing alert system for dosing errors and to compare the sensitivity of a proprietary system with and without institutional customization at a pediatric hospital. Methods A retrospective analysis of medication orders, orders causing dosing alerts, reported adverse drug events, and dosing errors during July, 2011 was conducted. Dosing errors with and without alerts were identified and the sensitivity of the system with and without customization was compared. Results There were 47 181 inpatient pediatric orders during the studied period; 257 dosing errors were identified (0.54%). The sensitivity of the system for identifying dosing errors was 54.1% (95% CI 47.8% to 60.3%) if customization had not occurred and increased to 60.3% (CI 54.0% to 66.3%) with customization (p=0.02). The sensitivity of the system for underdoses was 49.6% without customization and 60.3% with customization (p=0.01). Specificity of the customized system for dosing errors was 96.2% (CI 96.0% to 96.3%) with a positive predictive value of 8.0% (CI 6.8% to 9.3). All dosing errors had an alert over-ridden by the prescriber and 40.6% of dosing errors with alerts were administered to the patient. The lack of indication-specific dose ranges was the most common reason why an alert did not occur for a dosing error. Discussion Advances in dosing alert systems should aim to improve the sensitivity and positive predictive value of the system for dosing errors. Conclusions The dosing alert system had a low sensitivity and positive predictive value for dosing errors, but might have prevented dosing errors from reaching patients. Customization increased the sensitivity of the system for dosing errors. PMID:24496386

Comparison of two antigen assays for rapid intrapartum detection of vaginal group B streptococcal colonization.

PubMed

Green, M; Dashefsky, B; Wald, E R; Laifer, S; Harger, J; Guthrie, R

1993-01-01

As part of a clinical investigation evaluating the efficacy of intrapartum antigen detection for screening for heavy vaginal colonization with group B streptococci (GBS), we compared the performance of modified Bactigen and Directigen GBS latex particle agglutination (LPA) kits. Paired vaginal swabs obtained from women in labor were rapidly transported to the laboratory and used for culturing (both swabs) and LPA testing (one swab by each method). GBS growth was estimated semiquantitatively and further designated as light or heavy growth. Performance specifications for each method were determined by comparing LPA and culture results from the same swab. A total of 4,251 paired swabs were evaluated during the study period. The performance specifications for detecting GBS growth of any degree for Bactigen and Directigen, respectively, were as follows: sensitivity, 20 and 24%; specificity, 99 and 99%. The performance specifications for heavy colonization for Bactigen and Directigen, respectively, were as follows: sensitivity, 57 and 62%; specificity, 99 and 99%. Neither LPA kit was a sensitive indicator of vaginal colonization with GBS or neonatal infection.

Quantifying the effect of side branches in endothelial shear stress estimates

PubMed Central

Giannopoulos, Andreas A.; Chatzizisis, Yiannis S.; Maurovich-Horvat, Pal; Antoniadis, Antonios P.; Hoffmann, Udo; Steigner, Michael L.; Rybicki, Frank J.; Mitsouras, Dimitrios

2016-01-01

Background and aims Low and high endothelial shear stress (ESS) is associated with coronary atherosclerosis progression and high-risk plaque features. Coronary ESS is currently assessed via computational fluid dynamic (CFD) simulation in the lumen geometry determined from invasive imaging such as intravascular ultrasound and optical coherence tomography. This process typically omits side branches of the target vessel in the CFD model as invasive imaging of those vessels is not clinically-indicated. The purpose of this study was to determine the extent to which this simplification affects the determination of those regions of the coronary endothelium subjected to pathologic ESS. Methods We determined the diagnostic accuracy of ESS profiling without side branches to detect pathologic ESS in the major coronary arteries of 5 hearts imaged ex vivo with CT angiography. ESS of the three major coronary arteries was calculated both without (test model), and with (reference model) inclusion of all side branches >1.5 mm in diameter, using previously-validated CFD approaches. Diagnostic test characteristics (accuracy, sensitivity, specificity and negative and positive predictive value [NPV/PPV]) with respect to the reference model were assessed for both the entire length as well as only the proximal portion of each major coronary artery, where the majority of high-risk plaques occur. Results Using the model without side branches overall accuracy, sensitivity, specificity, NPV and PPV were 83.4%, 54.0%, 96%, 95.9% and 55.1%, respectively to detect low ESS, and 87.0%, 67.7%, 90.7%, 93.7% and 57.5%, respectively to detect high ESS. When considering only the proximal arteries, test characteristics differed for low and high ESS, with low sensitivity (67.7%) and high specificity (90.7%) to detect low ESS, and low sensitivity (44.7%) and high specificity (95.5%) to detect high ESS. Conclusions The exclusion of side branches in ESS vascular profiling studies greatly reduces the ability to detect regions of the major coronary arteries subjected to pathologic ESS. Single-conduit models can in general only be used to rule out pathologic ESS. PMID:27372207

Quantifying the effect of side branches in endothelial shear stress estimates.

PubMed

Giannopoulos, Andreas A; Chatzizisis, Yiannis S; Maurovich-Horvat, Pal; Antoniadis, Antonios P; Hoffmann, Udo; Steigner, Michael L; Rybicki, Frank J; Mitsouras, Dimitrios

2016-08-01

Low and high endothelial shear stress (ESS) is associated with coronary atherosclerosis progression and high-risk plaque features. Coronary ESS is currently assessed via computational fluid dynamic (CFD) simulation of coronary blood flow in the lumen geometry determined from invasive imaging such as intravascular ultrasound and optical coherence tomography. This process typically omits side branches of the target vessel in the CFD model as invasive imaging of those vessels is not usually clinically-indicated. The purpose of this study was to determine the extent to which this simplification affects the determination of those regions of the coronary endothelium subjected to pathologic ESS. We determined the diagnostic accuracy of ESS profiling without side branches to detect pathologic ESS in the major coronary arteries of 5 hearts imaged ex vivo with computed tomography angiography (CTA). ESS of the three major coronary arteries was calculated both without (test model), and with (reference model) inclusion of all side branches >1.5 mm in diameter, using previously-validated CFD approaches. Diagnostic test characteristics (accuracy, sensitivity, specificity and negative and positive predictive value [NPV/PPV]) with respect to the reference model were assessed for both the entire length as well as only the proximal portion of each major coronary artery, where the majority of high-risk plaques occur. Using the model without side branches overall accuracy, sensitivity, specificity, NPV and PPV were 83.4%, 54.0%, 96%, 95.9% and 55.1%, respectively to detect low ESS, and 87.0%, 67.7%, 90.7%, 93.7% and 57.5%, respectively to detect high ESS. When considering only the proximal arteries, test characteristics differed for low and high ESS, with low sensitivity (67.7%) and high specificity (90.7%) to detect low ESS, and low sensitivity (44.7%) and high specificity (95.5%) to detect high ESS. The exclusion of side branches in ESS vascular profiling studies greatly reduces the ability to detect regions of the major coronary arteries subjected to pathologic ESS. Single-conduit models can in general only be used to rule out pathologic ESS. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Sensitivity and specificity of CT scanning for determining the number of internally concealed packages in 'body-packers'.

PubMed

Asha, Stephen Edward; Higham, Matthew; Child, Peter

2015-05-01

If package counts on abdominal CTs of body-packers were known to be accurate, follow-up CTs could be avoided. The objective was to determine the accuracy of CT for the number of concealed packages in body-packers, and the reliability of package counts reported by body-packers who admit to concealing drugs. Suspected body-packers were identified from the emergency departments (ED) database. The medical record and radiology reports were reviewed for package counts determined by CT, patient-reported and physically retrieved. The last method was used as the reference standard. Sensitivity, specificity, positive predictive values (PPV) and negative predictive values (NPV) were calculated for CT package count accuracy. Reliability of patient-reported package counts was assessed using Pearson's correlation coefficient. There were 50 confirmed body-packers on whom 104 CT scans were performed. Data for the index and reference tests were available for 84 scans. The sensitivity, specificity, PPV and NPV for CT package count were 63% (95% CI 46% to 77%), 82% (95% CI 67% to 92%), 76% (95% CI 58% to 89%) and 71% (95% CI 56% to 83%) respectively. For CTs with a package count<15, the sensitivity, specificity, PPV and NPV for CT package count were 96% (95% CI 80% to 99%), 95% (95% CI 82% to 99%), 93% (95% CI 76% to 99%) and 97% (95% CI 86% to 100%), respectively. Correlation between patient-reported package counts and the number of packages retrieved was high (r=0.90, p<0.001, R2=81%). The accuracy of CT for determining the number of concealed packages is poor, although when applied to patients with few concealed packages accuracy is high and is useful as a rule-out test. Among patients who have admitted to drug concealment, the number of packages reported to be concealed is reliable. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Complexed prostate specific antigen provides significant enhancement of specificity compared with total prostate specific antigen for detecting prostate cancer.

PubMed

Brawer, M K; Cheli, C D; Neaman, I E; Goldblatt, J; Smith, C; Schwartz, M K; Bruzek, D J; Morris, D L; Sokoll, L J; Chan, D W; Yeung, K K; Partin, A W; Allard, W J

2000-05-01

Determining serum total prostate specific antigen (PSA) has proved to be a valuable diagnostic aid for detecting prostatic carcinoma, although the lack of specificity has limited its usefulness. Studies indicate that the use of percent free PSA would improve specificity while maintaining sensitivity. Since complexed PSA represents the major proportion of measurable PSA in serum, we determined whether it represents a single test alternative to the use of percent free PSA for the early detection of prostate cancer. Archival serum was obtained from 385 men with no evidence of malignancy on biopsy and 272 with biopsy confirmed prostate cancer. We determined the concentration and proportion of total, complexed and free PSA. Receiver operating characteristics analysis using total PSA results from all samples (range 0.32 to 117 ng./ml.) indicated that the areas under the curve for complexed PSA alone as well as the free-to-total and complexed-to-total PSA ratios were similar and significantly greater than those for total PSA alone. Within the range of 85% to 95% sensitivity receiver operating characteristics analysis revealed that the specificity of complexed PSA was higher than that of total PSA and equivalent to that of the free-to-total PSA ratio. We noted a similar improvement in specificity in the 4 to 10 ng./ml. total PSA range. Using published cutoff values for complexed, total and percent free PSA when total PSA was in the 4 to 10 ng./ml. range the sensitivity and specificity of complexed and percent free PSA were similar. Within the 4 to 10 ng./ml. total PSA range the population of patients with no evidence of malignancy and complexed PSA below the upper limit was different with respect to total PSA from that with no evidence of malignancy and free PSA greater than 25%. The measurement of complexed PSA represents an alternative to the use of percent free PSA, although the patient populations identified by the 2 tests are different.

Characterization of plasma cytokines in an infant population cohort of challenge-proven food allergy.

PubMed

Dang, T D; Tang, M L K; Koplin, J J; Licciardi, P V; Eckert, J K; Tan, T; Gurrin, L C; Ponsonby, A-L; Dharmage, S C; Allen, K J

2013-10-01

Sensitization to food allergens indicates the production of food-specific IgE; however, sensitization is not a definite indicator of allergic reaction upon ingestion (N Engl J Med, 344, 2001, 30: J Allergy Clin Immunol, 120, 2007, 491). Currently, food challenge is the best approach to identify the presence or absence of allergy. While 95% positive predictive values (PPVs) thresholds for sIgE can assist with identifying increased likelihood of allergy among those who are sensitized, there are no specific biological markers that differentiate between allergic and sensitized individuals. To determine whether plasma serum cytokine profiles predict (i) sensitization to peanut and egg and (ii) food allergy among sensitized infants. Peanut-sensitized (PT) and egg-sensitized 14-month-old infants and nonsensitized controls enrolled in HealthNuts, a population-based study of food allergy, underwent an oral food challenge (OFC). Blood was collected within 1 h after OFC. Serum levels of Th1, Th2 and regulatory cytokines were determined in allergic (n = 79), sensitized (n = 40) and nonsensitized, nonallergic (n = 37) infants by multiplex assay. Food-sensitized infants had significantly higher plasma IL-4, IL-13, IL-12p70 and lower IL-10 levels compared to nonsensitized infants. IL-10 and IL-6 levels were significantly higher in sensitized compared with allergic infants. Egg-allergic infants had significantly higher IL-13 and IL-12p70 levels compared to peanut-allergic (PA) infants. Levels of Th2-related cytokines in plasma are higher in food-sensitized infants, irrespective of clinical food allergy status. In contrast, IL-10 levels appear to predict food allergy among sensitized infants. Differences in IL-13 and IL-12p70 between egg- and peanut-allergic infants could help explain the different resolution rates of the allergies. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Utility of hand-held devices in diagnosis and triage of cardiovascular emergencies. Observations during implementation of a PACS-based system in an acute aortic syndrome (AAS) network.

PubMed

Matar, Ralph; Renapurkar, Rahul; Obuchowski, Nancy; Menon, Venu; Piraino, David; Schoenhagen, Paul

2015-01-01

Prompt diagnosis and early referral to specialized centers is critical for patients presenting with cardiovascular emergencies, including acute aortic syndromes (AAS). Prior data has suggested that mobile access to imaging studies with hand-held devices can accelerate diagnosis and management. We conducted a study to determine the diagnostic accuracy of a hand-held device compared to conventional dedicated work-stations for diagnosing a spectrum of cardiovascular emergencies, predominantly acute aortic pathology. This study included 104 cases who underwent computed tomography (CT)-scan during "on-call'' hours between January, 2013 and August, 2014 for suspected AAS. Assessment was performed on a hand-held device independently by two readers using an iPhone5 connected via secure connection to web-based PACS servers. The subsequent interpretation from a dedicated workstation coupled with the diagnosis at the time of discharge was used as the reference standard for determining the presence or absence of an acute abnormality. Sensitivity and Specificity were calculated on a per patient basis. Readers' sensitivity and specificity using the hand-held device to diagnose acute chest pathology were calculated. Hand-held device evaluation was determined to have a sensitivity of 85.2% and a specificity of 98.6% by reader A and a sensitivity of 96.3% and specificity of 100% by reader B. Of 103 cases interpreted by both readers, the readers agreed about the diagnosis in 98 cases (95.1%). This study demonstrates that hand-held devices can be a potential useful tool to assist in diagnosis and triage of patients presenting with cardiovascular emergencies. Further studies are needed to assess the impact of screen size and resolution. Copyright © 2015 Society of Cardiovascular Computed Tomography. Published by Elsevier Inc. All rights reserved.

Utility of contrast-enhanced harmonic EUS in the diagnosis of malignant gallbladder polyps (with videos).

PubMed

Choi, Jun-Ho; Seo, Dong-Wan; Choi, Joon Hyuk; Park, Do Hyun; Lee, Sang Soo; Lee, Sung Koo; Kim, Myung-Hwan

2013-09-01

The differential diagnosis between benign and malignant polyps of the gallbladder (GB) is often challenging. To evaluate whether contrast-enhanced harmonic EUS (CEH-EUS) might be an accurate method for discriminating malignant GB polyps from benign polyps. Observational study. Tertiary care medical center. Ninety-three patients with GB polyps larger than 10 mm in diameter that were detected by conventional EUS underwent CEH-EUS for evaluation of microvasculature. CEH-EUS was performed using a radial echoendoscope and the extended pure harmonic detection mode. The abilities of conventional EUS and CEH-EUS to diagnose malignant polyp were compared. Two blinded reviewers classified the perfusion images into 3 categories: diffuse enhancement, perfusion defect, or nonenhancement. The vessel images were categorized as having a regular spotty vessel, an irregular vessel, or no vessels. An irregular vessel pattern determined by CEH-EUS aided in the diagnosis of malignant polyps with a sensitivity and specificity of 90.3% and 96.6%, respectively. The presence of perfusion defects, determined by CEH-EUS, was calculated to diagnose malignant polyps with a sensitivity and specificity of 90.3% and 94.9%, respectively. Based on the definitely determined diagnosis, sensitivity and specificity for CEH-EUS were 93.5% and 93.2% versus 90.0% and 91.1% for conventional EUS. In 8 cases, management changed after CEH-EUS. A tertiary medical center with a limited number of patients. The presence of irregular intratumoral vessels or perfusion defects seen on CEH-EUS may be sensitive and accurate predictors of malignant GB polyps. CEH-EUS offers slightly improved diagnostic accuracy compared with EUS. Copyright © 2013 American Society for Gastrointestinal Endoscopy. All rights reserved.

Maternal peanut exposure during pregnancy and lactation reduces peanut allergy risk in offspring.

PubMed

López-Expósito, Iván; Song, Ying; Järvinen, Kirsi M; Srivastava, Kamal; Li, Xiu-Min

2009-11-01

Maternal allergy is believed to be a risk factor for peanut allergy (PNA) in children. However, there is no direct evidence of maternal transmission of PNA susceptibility, and it is unknown whether maternal peanut exposure affects the development of PNA in offspring. To investigate the influence of maternal PNA on offspring reactions to the first peanut exposure, and whether maternal low-dose peanut exposure during pregnancy and lactation influences these reactions and peanut sensitization in a murine model. Five-week-old offspring of PNA C3H/HeJ mothers (PNA-Ms) were challenged intragastrically with peanut (first exposure), and reactions were determined. In a subset of the experiment, PNA-Ms were fed a low dose of peanut (PNA-M/PN) or not fed peanut (PNA-M/none) during pregnancy and lactation. Their 5-week-old offspring were challenged intragastrically with peanut, and reactions were determined. In another subset of the experiment, offspring of PNA-M/PN or PNA-M/none were sensitized with peanut intragastrically for 6 weeks, and serum peanut-specific antibodies were determined. PNA-M offspring exhibited anaphylactic reactions at first exposure to peanut that were associated with peanut-specific IgG(1) levels and prevented by a platelet activation factor antagonist. In a subset experiment, PNA-M/PN offspring showed significantly reduced first-exposure peanut reactions, increased IgG(2a), and reduced mitogen-stimulated splenocyte cytokine production compared with PNA-M/none offspring. In an additional experiment, PNA-M/PN offspring showed reduction of peanut-specific IgE to active peanut sensitization. We show for the first time maternal transmission of susceptibility to first-exposure peanut reactions and active peanut sensitization. Low-dose peanut exposure during pregnancy and lactation reduced this risk.

Computer-aided auscultation of murmurs in children: evaluation of commercially available software.

PubMed

Lee, Cecilia; Rankin, Kathryn N; Zuo, Kevin J; Mackie, Andrew S

2016-10-01

Heart murmurs are common in children and may represent congenital or acquired cardiac pathology. Auscultation is challenging and many primary-care physicians lack the skill to differentiate innocent from pathologic murmurs. We sought to determine whether computer-aided auscultation (CardioscanTM) identifies which children require referral to a cardiologist. We consecutively enrolled children aged between 0 and 17 years with a murmur, innocent or pathologic, being evaluated in a tertiary-care cardiology clinic. Children being evaluated for the first time and patients with known cardiac pathology were eligible. We excluded children who had undergone cardiac surgery previously or were unable to sit still for auscultation. CardioscanTM auscultation was performed in a quiet room with the subject in the supine position. The sensitivity and specificity of a potentially pathologic murmur designation by CardioscanTM - that is, requiring referral - was determined using echocardiography as the reference standard. We enrolled 126 subjects (44% female) with a median age of 1.7 years, with 93 (74%) having cardiac pathology. The sensitivity and specificity of a potentially pathologic murmur determination by CardioscanTM for identification of cardiac pathology were 83.9 and 30.3%, respectively, versus 75.0 and 71.4%, respectively, when limited to subjects with a heart rate of 50-120 beats per minute. The combination of a CardioscanTM potentially pathologic murmur designation or an abnormal electrocardiogram improved sensitivity to 93.5%, with no haemodynamically significant lesions missed. Sensitivity of CardioscanTM when interpreted in conjunction with an abnormal electrocardiogram was high, although specificity was poor. Re-evaluation of computer-aided auscultation will remain necessary as advances in this technology become available.

Development of a direct PCR assay to detect Taenia multiceps eggs isolated from dog feces.

PubMed

Wang, Ning; Wang, Yu; Ye, Qinghua; Yang, Yingdong; Wan, Jie; Guo, Cheng; Zhan, Jiafei; Gu, Xiaobin; Lai, Weimin; Xie, Yue; Peng, Xuerong; Yang, Guangyou

2018-02-15

Taenia multiceps is a tapeworm that leads to the death of livestock, resulting in major economic losses worldwide. The adult stage of this parasite invades the small intestine of dogs and other canids. In the present study, we developed a direct PCR assay to detect T. multiceps eggs isolated from dog feces to help curb further outbreaks. The genomic DNA was rapidly released using a lysis buffer and the PCR reaction was developed to amplify a 433-bp fragment of the T. multiceps mitochondrial gene encoding NADH dehydrogenase subunit 5 (nad5) from eggs isolated from dog feces. The procedure could be completed within 3 h, including flotation. The sensitivity of the assay was determined by detecting DNA from defined numbers of eggs, and the specificity was determined by detecting DNA from other intestinal tapeworm and roundworm species that commonly infect dogs. In addition, 14 taeniid-positive fecal samples determined by the flotation technique were collected and further evaluated by the regular PCR and our direct PCR. The results showed that the direct PCR developed herein was sensitive enough to detect the DNA from as few as 10 T. multiceps eggs and that no cross-reactions with other tapeworm and roundworm were observed, suggesting its high sensitivity and specificity for T. multiceps detection. Moreover, 14 taeniid-positive samples were screened by the regular PCR and direct PCR, with detection rates of 78.6% and 85.7%, respectively. In conclusion, the direct PCR assay developed in the present study has high sensitivity and specificity to identify T. multiceps eggs isolated from dog feces and therefore could represent an invaluable tool to identify T. multiceps outbreaks and would contribute to future clinical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

MRI in multiple sclerosis: current status and future prospects

PubMed Central

Bakshi, Rohit; Thompson, Alan J; Rocca, Maria A; Pelletier, Daniel; Dousset, Vincent; Barkhof, Frederik; Inglese, Matilde; Guttmann, Charles R G; Horsfield, Mark A; Filippi, Massimo

2008-01-01

Many promising MRI approaches for research or clinical management of multiple sclerosis (MS) have recently emerged, or are under development or refinement. Advanced MRI methods need to be assessed to determine whether they allow earlier diagnosis or better identification of phenotypes. Improved post-processing should allow more efficient and complete extraction of information from images. Magnetic resonance spectroscopy should improve in sensitivity and specificity with higher field strengths and should enable the detection of a wider array of metabolites. Diffusion imaging is moving closer to the goal of defining structural connectivity and, thereby, determining the functional significance of lesions at specific locations. Cell-specific imaging now seems feasible with new magnetic resonance contrast agents. The imaging of myelin water fraction brings the hope of providing a specific measure of myelin content. Ultra-high-field MRI increases sensitivity, but also presents new technical challenges. Here, we review these recent developments in MRI for MS, and also look forward to refinements in spinal-cord imaging, optic-nerve imaging, perfusion MRI, and functional MRI. Advances in MRI should improve our ability to diagnose, monitor, and understand the pathophysiology of MS. PMID:18565455

Validity of self-reported eye disease and treatment in a population-based study: the Los Angeles Latino Eye Study.

PubMed

Patty, Lauren; Wu, Cathy; Torres, Mina; Azen, Stanley; Varma, Rohit

2012-09-01

To examine the validity of self-reported eye disease, including cataract, age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy (DR), and self-reported surgical treatment for cataract and DR in the Los Angeles Latino Eye Study (LALES). Population-based, cross-sectional study. A total of 6357 Latinos aged 40+ years from the LALES. Participants underwent a detailed interview, including survey questions about ocular health, diagnoses, and timing of last eye examination, and a standardized clinical examination. Self-report was compared with examination to determine sensitivity and specificity by length of time since last eye examination. Stepwise logistic regression was used to determine factors associated with inaccurate self-report. Sensitivity and specificity were calculated for 4 self-reported eye diseases (cataract, AMD, glaucoma, and DR) and for surgical treatment of cataract and DR. Odds ratios (ORs) were determined for factors associated with inaccurate self-report underestimating eye disease and treatment. For each disease, sensitivity and specificity in those who reported their last eye examination as <1 year ago were 36.8% and 92.5% for cataract, 37.7% and 96.3% for glaucoma, 5.1% and 98.9% for AMD, and 25.7% and 94.2% for DR, respectively. Self-report was less accurate with increasing time since last eye examination. Inaccurate self-report was independently associated with better visual acuity (OR, 2.4), <2 comorbidities (OR, 1.7), last eye examination/visit 1 to 5 years ago and ≥ 5 years ago (OR, 2.3 and 4.9, respectively), and less education (OR, 1.3 for 7-12 years and 1.7 for <7 years). Of 88 participants surgically treated for cataract who reported an eye examination <1 year ago, sensitivity and specificity of self-reported surgical history were 90.9% and 99.9%, respectively. Of the 31 participants treated for DR (laser/surgery) and reporting an eye examination <1 year ago, sensitivity and specificity of self-reported surgical history were 19.4% and 99.6%, respectively. Among Latinos, self-reporting of eye disease and surgical history provides a significant underestimate of the disease burden. This may lead to significant misclassification in vision research if self-report alone is used to identify persons with eye disease. Copyright © 2012 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Validity of self reported eye disease and treatment in a population-based study: The Los Angeles Latino Eye Study

PubMed Central

Patty, Lauren; Wu, Cathy; Torres, Mina; Azen, Stanley; Varma, Rohit

2012-01-01

Purpose To examine the validity of self-reported eye disease, including cataract, age-related macular degeneration (AMD), glaucoma, and diabetic retinopathy (DR), and self-reported surgical treatment for cataract and DR in the Los Angeles Latino Eye Study (LALES). Design Population-based cross-sectional study Participants 6357 Latinos age 40+ years from the LALES Methods Participants underwent a detailed interview, including survey questions about ocular health, diagnoses and timing of last eye examination, and a standardized clinical examination. Self report was compared to examination to determine sensitivity and specificity by length of time since last eye examination. Stepwise logistic regression was used to determine factors associated with inaccurate self report. Main Outcome Measures Sensitivity and specificity were calculated for four self reported eye diseases (cataract, AMD, glaucoma, DR) and for surgical treatment of cataract and DR. Odds ratios (OR) were determined for factors associated with inaccurate self report underestimating eye disease and treatment. Results For each disease, sensitivity and specificity in those who reported their last eye examination as <1 year ago were: 36.8%, 92.5% for cataract; 37.7%, 96.3% for glaucoma; 5.1%, 98.9% for AMD; and 25.7%, 94.2% for DR. Self report was less accurate with increasing time since last eye examination. Inaccurate self report was independently associated with better visual acuity (OR=2.4), <2 comorbidities (OR=1.7), last eye exam/visit 1–5 years ago and ≥5 years ago (OR=2.3 and 4.9, respectively), and less education (OR=1.3 for 7–12 years and 1.7 for <7 years). Of 88 participants surgically treated for cataract who reported an eye examination <1 year ago, sensitivity and specificity of self-reported surgical history were 90.9% and 99.9%. Of the 31 participants treated for DR (laser/surgery) and reporting an eye examination <1 year ago, sensitivity and specificity of self-reported surgical history were 19.4% and 99.6%. Conclusions Among Latinos, self reporting of eye disease and surgical history provides a significant underestimate of the disease burden. This may lead to significant misclassification in vision research if self report alone is used to identify persons with eye disease. PMID:22537615

The role of procalcitonin in neonatal intensive care unit patients with candidemia.

PubMed

Montagna, Maria Teresa; Coretti, Caterina; Rella, Antonella; Barbuti, Giovanna; Manca, Fabio; Montagna, Osvaldo; Laforgia, Nicola; Caggiano, Giuseppina

2013-01-01

Candidemia is a major infectious complication in neonatal patients. The isolation of yeasts from blood is still the "gold standard" for its diagnosis, but other laboratory markers (i.e., circulating antigens) have been studied with varying specificities and sensitivities. The aim of this study was to evaluate the role of procalcitonin for the diagnosis of candidemia in neonatal patients at high risk. To verify if the use of different commercial methods can highlight dissimilar results of sensitivity and/or specificity, the determination of procalcitonin serum levels was estimated by two systems. Overall, 90 patients from a Neonatal Intensive Care Units were enrolled, of whom six developed Candida bloodstream infection. Four of six infants with candidemia had slight increase of procalcitonin values (0.5-1 ng/mL). Only one baby showed very high levels but he had fungal and bacterial sepsis at the same time, while no elevation was observed in the sixth patient. No statistically significant difference was observed between two different methods at the time of monitoring (p>0.643). Both methods showed a sensitivity of 83.3 % at diagnosis, while the specificity was 73.8 and 63.1 % by methods A and B, respectively. In the light of the low sensibility and specificity of this assay, we can assume that the determination of procalcitonin would not seem to play a significant role in the diagnosis of fungal infection in neonatal patients.

Correlation between the immunological condition and the results of immunoenzymatic tests in diagnosing infectious mononucleosis.

PubMed

Tamaro, Giorgio; Donato, Michela; Princi, Tanja; Parco, Sergio

2009-04-01

A symptom-based diagnosis of infectious mononucleosis is not sufficiently accurate, since some clinical symptoms of infectious mononucleosis are also detected in other virally induced diseases. Moreover, not all patients suffering from infectious mononucleosis show circulating atypical lymphocytes, which are considered characteristic of this disease. Therefore, when this disorder is suspected, serum analyses are carried out to detect the presence of certain immunoglobulins associated with infectious mononucleosis in the patient's blood. The aim of this study was to evaluate the sensitivity and the specificity of a rapid test detecting heterophil antibodies in diagnosing infectious mononucleosis in a paediatric population. We considered 163 paediatric patients with suspected infectious mononucleosis and we tested their serums to detect heterophil antibodies (using an inexpensive and rapid test) and specific immunoglobulins directed against Epstein-Barr virus (EBV) (these assays are known to be characterized by high sensitivity and specificity, but are more expensive and time-consuming). By comparing the results of the rapid test with those of the other assays, we found that the sensitivity of the first test was 61.8%, whereas its specificity was sufficiently high (about 90%). We show that, in paediatric patients, the detection of heterophil antibodies is not a very sensitive test, therefore the determination of immunoglobulins against specific antigens of EBV is recommended.

Highly Sensitive Multiplex Assay for Detection of Human Immunodeficiency Virus Type 1 and Hepatitis C Virus RNA

PubMed Central

Giachetti, C.; Linnen, J. M.; Kolk, D. P.; Dockter, J.; Gillotte-Taylor, K.; Park, M.; Ho-Sing-Loy, M.; McCormick, M. K.; Mimms, L. T.; McDonough, S. H.

2002-01-01

Various nucleic acid assays have been developed and implemented for diagnostics and therapeutic monitoring of human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) infections. The high-throughput, semiautomated assays described here were developed to provide a method suitable for screening plasma specimens for the presence of HIV-1 and HCV RNAs. Three assays were developed: a multiplex HIV-1/HCV assay for simultaneous detection of HIV-1 and HCV, and discriminatory assays for specific detection of HIV-1 and HCV. The assay systems utilize three proprietary technologies: (i) target capture-based sample preparation, (ii) transcription-mediated amplification (TMA), and (iii) hybridization protection assay (HPA). An internal control is incorporated into each reaction to control for every step of the assay and identify random false-negative reactions. The assays demonstrated a sensitivity of at least 100 copies/ml for each target, and they detected with similar sensitivity all major variants of HCV and HIV-1, including HIV-1 group O strains. Assay sensitivity for one virus was not affected by the presence of the other. The specificity of these TMA-driven assays was ≥99.5% in both normal donor specimens and plasma containing potentially interfering substances or other blood-borne pathogens. Statistical receiver operating characteristic plots of 1 − specificity versus sensitivity data determined very wide analyte cutoff values for each assay at the point at which the assay specificity and sensitivity were both ≥99.5%. The sensitivity, specificity, and throughput capability predict that these assays will be valuable for large-volume plasma screening, either in a blood bank setting or in other diagnostic applications. PMID:12089255

Accurate antemortem diagnosis of equine protozoal myeloencephalitis (EPM) based on detecting intrathecal antibodies against Sarcocystis neurona using the SnSAG2 and SnSAG4/3 ELISAs.

PubMed

Reed, S M; Howe, D K; Morrow, J K; Graves, A; Yeargan, M R; Johnson, A L; MacKay, R J; Furr, M; Saville, W J A; Williams, N M

2013-01-01

Recent work demonstrated the value of antigen-specific antibody indices (AI and C-value) to detect intrathecal antibody production against Sarcocystis neurona for antemortem diagnosis of equine protozoal myeloencephalitis (EPM). The study was conducted to assess whether the antigen-specific antibody indices can be reduced to a simple serum : cerebrospinal fluid (CSF) titer ratio to achieve accurate EPM diagnosis. Paired serum and CSF samples from 128 horses diagnosed by postmortem examination. The sample set included 44 EPM cases, 35 cervical-vertebral malformation (CVM) cases, 39 neurologic cases other than EPM or CVM, and 10 non-neurologic cases. Antibodies against S. neurona were measured in serum and CSF pairs using the SnSAG2 and SnSAG4/3 (SnSAG2, 4/3) ELISAs, and the ratio of each respective serum titer to CSF titer was determined. Likelihood ratios and diagnostic sensitivity and specificity were calculated based on serum titers, CSF titers, and serum : CSF titer ratios. Excellent diagnostic sensitivity and specificity was obtained from the SnSAG2, 4/3 serum : CSF titer ratio. Sensitivity and specificity of 93.2 and 81.1%, respectively, were achieved using a ratio cutoff of ≤100, whereas sensitivity and specificity were 86.4 and 95.9%, respectively, if a more rigorous cutoff of ≤50 was used. Antibody titers in CSF also provided good diagnostic accuracy. Serum antibody titers alone yielded much lower sensitivity and specificity. The study confirms the value of detecting intrathecal antibody production for antemortem diagnosis of EPM, and they further show that the antigen-specific antibody indices can be reduced in practice to a simple serum : CSF titer ratio. Copyright © 2013 by the American College of Veterinary Internal Medicine.

Blinded study determination of high sensitivity and specificity microchip electrophoresis-SSCP/HA to detect mutations in the p53 gene.

PubMed

Hestekin, Christa N; Lin, Jennifer S; Senderowicz, Lionel; Jakupciak, John P; O'Connell, Catherine; Rademaker, Alfred; Barron, Annelise E

2011-11-01

Knowledge of the genetic changes that lead to disease has grown and continues to grow at a rapid pace. However, there is a need for clinical devices that can be used routinely to translate this knowledge into the treatment of patients. Use in a clinical setting requires high sensitivity and specificity (>97%) in order to prevent misdiagnoses. Single-strand conformational polymorphism (SSCP) and heteroduplex analysis (HA) are two DNA-based, complementary methods for mutation detection that are inexpensive and relatively easy to implement. However, both methods are most commonly detected by slab gel electrophoresis, which can be labor-intensive, time-consuming, and often the methods are unable to produce high sensitivity and specificity without the use of multiple analysis conditions. Here, we demonstrate the first blinded study using microchip electrophoresis (ME)-SSCP/HA. We demonstrate the ability of ME-SSCP/HA to detect with 98% sensitivity and specificity >100 samples from the p53 gene exons 5-9 in a blinded study in an analysis time of <10 min. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Clinical Effectiveness of Prospectively Reported Sonographic Twinkling Artifact for the Diagnosis of Renal Calculus in Patients Without Known Urolithiasis.

PubMed

Masch, William R; Cohan, Richard H; Ellis, James H; Dillman, Jonathan R; Rubin, Jonathan M; Davenport, Matthew S

2016-02-01

The purpose of this study was to determine the clinical effectiveness of prospectively reported sonographic twinkling artifact for the diagnosis of renal calculus in patients without known urolithiasis. All ultrasound reports finalized in one health system from June 15, 2011, to June 14, 2014, that contained the words "twinkle" or "twinkling" in reference to suspected renal calculus were identified. Patients with known urolithiasis or lack of a suitable reference standard (unenhanced abdominal CT with ≤ 2.5-mm slice thickness performed ≤ 30 days after ultrasound) were excluded. The sensitivity, specificity, and positive likelihood ratio of sonographic twinkling artifact for the diagnosis of renal calculus were calculated by renal unit and stratified by two additional diagnostic features for calcification (echogenic focus, posterior acoustic shadowing). Eighty-five patients formed the study population. Isolated sonographic twinkling artifact had sensitivity of 0.78 (82/105), specificity of 0.40 (26/65), and a positive likelihood ratio of 1.30 for the diagnosis of renal calculus. Specificity and positive likelihood ratio improved and sensitivity declined when the following additional diagnostic features were present: sonographic twinkling artifact and echogenic focus (sensitivity, 0.61 [64/105]; specificity, 0.65 [42/65]; positive likelihood ratio, 1.72); sonographic twinkling artifact and posterior acoustic shadowing (sensitivity, 0.31 [33/105]; specificity, 0.95 [62/65]; positive likelihood ratio, 6.81); all three features (sensitivity, 0.31 [33/105]; specificity, 0.95 [62/65]; positive likelihood ratio, 6.81). Isolated sonographic twinkling artifact has a high false-positive rate (60%) for the diagnosis of renal calculus in patients without known urolithiasis.

Laboratory evaluation on the sensitivity and specificity of a novel and rapid detection method for malaria diagnosis based on magneto-optical technology (MOT).

PubMed

Mens, Petra F; Matelon, Raphael J; Nour, Bakri Y M; Newman, Dave M; Schallig, Henk D F H

2010-07-19

This study describes the laboratory evaluation of a novel diagnostic platform for malaria. The Magneto Optical Test (MOT) is based on the bio-physical detection of haemozoin in clinical samples. Having an assay time of around one minute, it offers the potential of high throughput screening. Blood samples of confirmed malaria patients from different regions of Africa, patients with other diseases and healthy non-endemic controls were used in the present study. The samples were analysed with two reference tests, i.e. an histidine rich protein-2 based rapid diagnostic test (RDT) and a conventional Pan-Plasmodium PCR, and the MOT as index test. Data were entered in 2 x 2 tables and analysed for sensitivity and specificity. The agreement between microscopy, RDT and PCR and the MOT assay was determined by calculating Kappa values with a 95% confidence interval. The observed sensitivity/specificity of the MOT test in comparison with clinical description, RDT or PCR ranged from 77.2 - 78.8% (sensitivity) and from 72.5 - 74.6% (specificity). In general, the agreement between MOT and the other assays is around 0.5 indicating a moderate agreement between the reference and the index test. However, when RDT and PCR are compared to each other, an almost perfect agreement can be observed (k = 0.97) with a sensitivity and specificity of >95%. Although MOT sensitivity and specificity are currently not yet at a competing level compared to other diagnostic test, such as PCR and RDTs, it has a potential to rapidly screen patients for malaria in endemic as well as non-endemic countries.

Acute Brain Imaging in Children: Can MRI Replace CT as a Screening Tool?

PubMed

Wagner, Matthias W; Kontzialis, Marinos; Seeburg, Daniel; Stern, Steven E; Oshmyansky, Alexander; Poretti, Andrea; Huisman, Thierry A G M

2016-01-01

To determine if axial T2-weighted imaging can serve as screening tool for pediatric brain imaging. We retrospectively evaluated consecutive brain magnetic resonance imaging (MRI) data of 161 children (74 girls) with a mean age of 7.44 ± 5.71 years. Standard of reference was the final report of neuroradiology attendings. Three readers with different levels of experience were blinded for clinical diagnoses and study indications. First, readers studied only the axial T2-weighted screening sequence. Second, they studied all available anatomical and functional MRI sequences as performed per standard protocol for each clinical indication. The readings were classified as normal or abnormal. Sensitivity and specificity were measured. Axial T2 screening yielded a sensitivity of 77-88% and a specificity of 92%. The full studies/data sets had a sensitivity of 89-95% and a specificity of 86-93%. Nineteen of 167 studies were acquired for acute and 148 of 167 studies for nonacute clinical indication. Twenty-five false-negative diagnoses paneled in three groups were made by all readers together. Readers misread four of 19 studies with acute and 21 of 148 studies with nonacute clinical indication. Four of 21 misread studies with nonacute indications harbored unexpected findings needing management. Axial T2 screening can detect pediatric brain abnormalities with high sensitivity and specificity and can possibly replace CT as screening tool if the reading physician is aware of possible limitations/pitfalls. The level of experience influences sensitivity and specificity. Adding diffusion-weighted imaging and susceptibility-weighted imaging to a 3-dimensional T2-weighted sequence would most likely further increase sensitivity and specificity. Copyright © 2015 by the American Society of Neuroimaging.

Brain metabolic pattern analysis using a magnetic resonance spectra classification software in experimental stroke.

PubMed

Jiménez-Xarrié, Elena; Davila, Myriam; Candiota, Ana Paula; Delgado-Mederos, Raquel; Ortega-Martorell, Sandra; Julià-Sapé, Margarida; Arús, Carles; Martí-Fàbregas, Joan

2017-01-13

Magnetic resonance spectroscopy (MRS) provides non-invasive information about the metabolic pattern of the brain parenchyma in vivo. The SpectraClassifier software performs MRS pattern-recognition by determining the spectral features (metabolites) which can be used objectively to classify spectra. Our aim was to develop an Infarct Evolution Classifier and a Brain Regions Classifier in a rat model of focal ischemic stroke using SpectraClassifier. A total of 164 single-voxel proton spectra obtained with a 7 Tesla magnet at an echo time of 12 ms from non-infarcted parenchyma, subventricular zones and infarcted parenchyma were analyzed with SpectraClassifier ( http://gabrmn.uab.es/?q=sc ). The spectra corresponded to Sprague-Dawley rats (healthy rats, n = 7) and stroke rats at day 1 post-stroke (acute phase, n = 6 rats) and at days 7 ± 1 post-stroke (subacute phase, n = 14). In the Infarct Evolution Classifier, spectral features contributed by lactate + mobile lipids (1.33 ppm), total creatine (3.05 ppm) and mobile lipids (0.85 ppm) distinguished among non-infarcted parenchyma (100% sensitivity and 100% specificity), acute phase of infarct (100% sensitivity and 95% specificity) and subacute phase of infarct (78% sensitivity and 100% specificity). In the Brain Regions Classifier, spectral features contributed by myoinositol (3.62 ppm) and total creatine (3.04/3.05 ppm) distinguished among infarcted parenchyma (100% sensitivity and 98% specificity), non-infarcted parenchyma (84% sensitivity and 84% specificity) and subventricular zones (76% sensitivity and 93% specificity). SpectraClassifier identified candidate biomarkers for infarct evolution (mobile lipids accumulation) and different brain regions (myoinositol content).

Home oximetry to screen for obstructive sleep apnoea in Down syndrome.

PubMed

Hill, Catherine M; Elphick, Heather E; Farquhar, Michael; Gringras, Paul; Pickering, Ruth M; Kingshott, Ruth N; Martin, Jane; Reynolds, Janine; Joyce, Anna; Gavlak, Johanna C; Evans, Hazel J

2018-05-14

Children with Down syndrome are at high risk of obstructive sleep apnoea (OSA) and screening is recommended. Diagnosis of OSA should be confirmed with multichannel sleep studies. We aimed to determine whether home pulse oximetry (HPO) discriminates children at high risk of OSA, who need further diagnostic multichannel sleep studies. Cross-sectional prospective study in a training sample recruited through three UK centres. Validation sample used single-centre retrospective analysis of clinical data. Children with Down syndrome aged 0.5-6 years. Diagnostic multichannel sleep study and HPO. Sensitivity and specificity of HPO to predict moderate-to-severe OSA. 161/202 children with Down syndrome met quality criteria for inclusion and 25 had OSA. In this training sample, the best HPO parameter predictors of OSA were the delta 12 s index >0.555 (sensitivity 92%, specificity 65%) and 3% oxyhaemoglobin (SpO 2 ) desaturation index (3% ODI)>6.15 dips/hour (sensitivity 92%, specificity 63%). Combining variables (delta 12 s index, 3% ODI, mean and minimum SpO 2 ) achieved sensitivity of 96% but reduced specificity to 52%. All predictors retained or improved sensitivity in a clinical validation sample of 50 children with variable loss of specificity, best overall was the delta 12 s index, a measure of baseline SpO 2 variability (sensitivity 92%; specificity 63%). HPO screening could halve the number of children with Down syndrome needing multichannel sleep studies and reduce the burden on children, families and health services alike. This approach offers a practical universal screening approach for OSA in Down syndrome that is accessible to the non-specialist paediatrician. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

[Validity of expired carbon monoxide and urine cotinine using dipstick method to assess smoking status].

PubMed

Park, Su San; Lee, Ju Yul; Cho, Sung-Il

2007-07-01

We investigated the validity of the dipstick method (Mossman Associates Inc. USA) and the expired CO method to distinguish between smokers and nonsmokers. We also elucidated the related factors of the two methods. This study included 244 smokers and 50 ex-smokers, recruited from smoking cessation clinics at 4 local public health centers, who had quit for over 4 weeks. We calculated the sensitivity, specificity and Kappa coefficient of each method for validity. We obtained ROC curve, predictive value and agreement to determine the cutoff of expired air CO method. Finally, we elucidated the related factors and compared their effect powers using the standardized regression coefficient. The dipstick method showed a sensitivity of 92.6%, specificity of 96.0% and Kappa coefficient of 0.79. The best cutoff value to distinguish smokers was 5-6 ppm. At 5 ppm, the expired CO method showed a sensitivity of 94.3%, specificity of 82.0% and Kappa coefficient of 0.73. And at 6 ppm, sensitivity, specificity and Kappa coefficient were 88.5%, 86.0% and 0.64, respectively. Therefore, the dipstick method had higher sensitivity and specificity than the expired CO method. The dipstick and expired CO methods were significantly increased with increasing smoking amount. With longer time since the last smoking, expired CO showed a rapid decrease after 4 hours, whereas the dipstick method showed relatively stable levels for more than 4 hours. The dipstick and expired CO methods were both good indicators for assessing smoking status. However, the former showed higher sensitivity and specificity and stable levels over longer hours after smoking, compared to the expired CO method.

Evaluation of FlaB1, FlaB2, FlaB3, and Tp0463 of Treponema pallidum for serodiagnosis of syphilis.

PubMed

Jiang, Chuanhao; Xiao, Jinhong; Xie, Yafeng; Xiao, Yongjian; Wang, Chuan; Kuang, Xingxing; Xu, Man; Li, Ranhui; Zeng, Tiebing; Liu, Shuanquan; Yu, Jian; Zhao, Feijun; Wu, Yimou

2016-02-01

Syphilis is a multistage disease caused by the invasive spirochete Treponema pallidum subsp. pallidum, and accurate diagnosis is important for the prevention and treatment of syphilis. Here, to identify appropriate diagnostic antigens for serodiagnosis of syphilis, 6 recombinant proteins were expressed in Escherichia coli and purified, including flagellins (FlaB1 [Tp0868], FlaB2 [Tp0792], and FlaB3 [Tp0870]), Tp0463, Tp0751, and Tp1038. The sensitivities were determined by screening sera from individuals with primary (n=82), secondary (n=115), latent (n=105), and congenital (n=65) syphilis. The specificities were determined by screening sera from uninfected controls (n=30) and potentially cross-reactive infections including Lyme disease (n=30), leptospirosis (n=5), and hepatitis B (n=30). Our data showed that FlaB1, FlaB2, FlaB3, Tp0463, and Tp1038 exhibited higher overall sensitivities and specificities for detecting IgG antibody, with 95.4% and 98.9%, 92.6% and 95.8%, 95.1% and 95.8%, 92.6% and 97.9%, and 95.9% and 98.9%, respectively. In contrast, Tp0751 demonstrated only an overall sensitivity of 39.2%. For comparison, the sensitivity and specificity of Architect Syphilis TP were determined to be 98.1% and 93.7%, respectively. In addition, FlaB1, FlaB2, FlaB3, and Tp0463 demonstrated excellent performance for detecting IgM antibody in primary and congenital syphilis, with sensitivities of 76.8% and 83.1%, 72.0% and 87.7%, 74.4% and 89.2%, and 64.6% and 75.3%, respectively. These results indicate that FlaB1, FlaB2, FlaB3, and Tp0463 could be as novel diagnostic candidates for serodiagnosis of syphilis. Copyright © 2016 Elsevier Inc. All rights reserved.

[Effect of inoculum size on sensitivity and specificity of the double-disk synergy test for the detection of wide-spectrum beta-lactamases].

PubMed

Bedenić, B; Boras, A

2001-01-01

The plasmid-mediated extended-spectrum beta-lactamases (ESBL) confer resistance to oxymino-cephalosporins, such as cefotaxime, ceftazidime, and ceftriaxone and to monobactams such as aztreonam. It is well known fact that ESBL producing bacteria exhibit a pronounced inoculum effect against broad spectrum cephalosporins like ceftazidime, cefotaxime, ceftriaxone and cefoperazone. The aim of this investigation was to determine the effect of inoculum size on the sensitivity and specificity of double-disk synergy test (DDST) which is the test most frequently used for detection of ESBLs, in comparison with other two methods (determination of ceftazidime MIC with and without clavulanate and inhibitor potentiated disk-diffusion test) which are seldom used in clinical laboratories. The experiments were performed on a set of K. pneumoniae strains with previously characterized beta-lactamases which comprise: 10 SHV-5 beta-lactamase producing K. pneumoniae, 20 SHV-2 + 1 SHV 2a beta-lactamase producing K. pneumoniae, 7 SHV-12 beta-lactamase producing K. pneumoniae, 39 putative SHV ESBL producing K. pneumoniae and 26 K. pneumoniae isolates highly susceptible to ceftazidime according to Kirby-Bauer disk-diffusion method and thus considered to be ESBL negative. According to the results of this investigation, increase in inoculum size affected more significantly the sensitivity of DDST than of other two methods. The sensitivity of the DDST was lower when a higher inoculum size of 10(8) CFU/ml was applied, in distinction from other two methods (MIC determination and inhibitor potentiated disk-diffusion test) which retained high sensitivity regardless of the density of bacterial suspension. On the other hand, DDST displayed higher specificity compared to other two methods regardless of the inoculum size. This investigation found that DDST is a reliable method but it is important to standardize the inoculum size.

Steroid Signaling and Temperature-Dependent Sex Determination – Reviewing the Evidence for Early Action of Estrogen during Ovarian Determination in the Red-Eared Slider Turtle (Trachemys scripta elegans)

PubMed Central

Ramsey, Mary; Crews, David

2009-01-01

The developmental processes underlying gonadal differentiation are conserved across vertebrates, but the triggers initiating these trajectories are extremely variable. The red-eared slider turtle (Trachemys scripta elegans) exhibits temperature-dependent sex determination (TSD), a system where incubation temperature during a temperature-sensitive period of development determines offspring sex. However, gonadal sex is sensitive to both temperature and hormones during this period – particularly estrogen. We present a model for temperature-based differences in aromatase expression as a critical step in ovarian determination. Localized estrogen production facilitates ovarian development while inhibiting male-specific gene expression. At male-producing temperatures aromatase is not upregulated, thereby allowing testis development. PMID:18992835

Development and clinical performance of high throughput loop-mediated isothermal amplification for detection of malaria

PubMed Central

Perera, Rushini S.; Ding, Xavier C.; Tully, Frank; Oliver, James; Bright, Nigel; Bell, David; Chiodini, Peter L.; Gonzalez, Iveth J.; Polley, Spencer D.

2017-01-01

Background Accurate and efficient detection of sub-microscopic malaria infections is crucial for enabling rapid treatment and interruption of transmission. Commercially available malaria LAMP kits have excellent diagnostic performance, though throughput is limited by the need to prepare samples individually. Here, we evaluate the clinical performance of a newly developed high throughput (HTP) sample processing system for use in conjunction with the Eiken malaria LAMP kit. Methods The HTP system utilised dried blood spots (DBS) and liquid whole blood (WB), with parallel sample processing of 94 samples per run. The system was evaluated using 699 samples of known infection status pre-determined by gold standard nested PCR. Results The sensitivity and specificity of WB-HTP-LAMP was 98.6% (95% CI, 95.7–100), and 99.7% (95% CI, 99.2–100); sensitivity of DBS-HTP-LAMP was 97.1% (95% CI, 93.1–100), and specificity 100% against PCR. At parasite densities greater or equal to 2 parasites/μL, WB and DBS HTP-LAMP showed 100% sensitivity and specificity against PCR. At densities less than 2 p/μL, WB-HTP-LAMP sensitivity was 88.9% (95% CI, 77.1–100) and specificity was 99.7% (95% CI, 99.2–100); sensitivity and specificity of DBS-HTP-LAMP was 77.8% (95% CI, 54.3–99.5) and 100% respectively. Conclusions The HTP-LAMP system is a highly sensitive diagnostic test, with the potential to allow large scale population screening in malaria elimination campaigns. PMID:28166235

Effect of Sport Related Concussion on Clinically Measured Simple Reaction Time

PubMed Central

Eckner, James T.; Kutcher, Jeffrey S.; Broglio, Steven P.; Richardson, James K.

2013-01-01

Background Reaction time (RT) is a valuable component of the sport concussion assessment battery. RT is typically measured using computers running specialized software, which limits its applicability in some athletic settings and populations. To address this, we developed a simple clinical test of RT (RTclin) that involves grasping a falling measuring stick. Purpose To determine the effect of concussion on RTclin and its sensitivity and specificity for concussion. Materials and methods Concussed athletes (n=28) and non-concussed control teammates (n=28) completed RTclin assessments at baseline and within 48 hours of injury. Repeated measures ANOVA compared mean baseline and follow-up RTclin values between groups. Sensitivity and specificity were calculated over a range of reliable change confidence levels. Results RTclin differed significantly between groups (p < .001): there was significant prolongation from baseline to post-injury in the concussed group (p= .003), with a trend toward improvement in the control group (p = .058). Sensitivity and specificity were maximized when a critical change value of 0 ms was applied (i.e., any increase in RTclin from baseline was interpreted as abnormal), which corresponded to a sensitivity of 75%, specificity of 68%, and a 65% reliable change confidence level. Conclusions RTclin appears sensitive to the effects of concussion and distinguished concussed and non-concussed athletes with similar sensitivity and specificity to other commonly used concussion assessment tools. Given its simplicity, low cost, and minimal time requirement, RTclin should be considered a viable component of the sports medicine provider’s multifaceted concussion assessment battery. PMID:23314889

The prevalence and diagnostic value of specific IgE antibodies to inhalant, animal and plant food, and ficus allergens in patients with natural rubber latex allergy.

PubMed

Ebo, D G; Bridts, C H; Hagendorens, M M; De Clerck, L S; Stevens, W J

2003-01-01

It is well recognised that natural rubber latex allergy can be associated with serological cross-reactivity to plant allergens, especially tropical fruits and Ficus. In contrast, data on the frequency and clinical value of specific IgE antibodies against these allergens remain rare. In addition, little is known about the prevalence and diagnostic value of specific IgE antibodies to classical inhalant and animal allergens in NRL allergic patients. The purpose of this study was to investigate the prevalence, the sensitivity, and the specificity of these different specific IgE antibodies in patients suffering from NRL allergy. Serum samples of 42 NRL allergic adults were investigated. All had a history of NRL allergy confirmed by a positive skin test for latex and a positive latex-specific IgE. Samples were analysed for IgE antibodies against 9 plant food allergens (avocado, banana, chestnut, fig, kiwi, papaya, peanut, pineapple and tomato) and Ficus benjamina. A specific IgE quantification for 3 animal food allergens (codfish, cow's milk, egg's white) and 8 common inhalant allergens (Dermatophagoïdes pteronyssinus, birch pollen, timothy grass pollen, mugwort pollen, cat and dog epithelium, Aspergillus fumigatus and Cladosporium herbarum) was also performed. Because double blind placebo-controlled challenges could not be considered, for ethical reasons, patient's food allergy or immediate hypersensitivity for Ficus and inhalant allergens was documented by a standardised questionnaire. Diagnosis of atopy was based on a relevant history and the presence of a specific IgE antibody to at least one classical inhalant allergen. For some IgE determinations presence or absence of cross-reactivity was investigated by CAP-inhibition tests. A specific IgE antibody to at least one of the investigated inhalant and animal food allergens was found in respectively 76% and 12% of the serum samples. A plant food-specific IgE antibody was observed in 88% of the serum samples, most frequently to papaya (71%) and least frequently to kiwi (17%). Twenty-nine percent of the serum samples contained Ficus-IgE. According to the questionnaire and the threshold of 0.35 kUa/L, sensitivity of the plant food IgE antibodies varied between 0% for papaya and 73% for avocado. Specificity varied between 28% for papaya and 91% for kiwi. For Ficus-IgE sensitivity was 20% and specificity 70%. For inhalant and animal food allergens sensitivity and specificity of the IgE quantification correlated generally well with the values obtained in non-NRL allergic adults. Determination of specific IgE to the investigated plant foods and Ficus was not always a sensitive neither a specific test to establish the clinical diagnosis of this allergy.

Immunity to Salmonella typhi: considerations relevant to measurement of cellular immunity in typhoid-endemic regions.

PubMed Central

Murphy, J R; Wasserman, S S; Baqar, S; Schlesinger, L; Ferreccio, C; Lindberg, A A; Levine, M M

1989-01-01

Experiments were performed in Baltimore, Maryland and in Santiago, Chile, to determine the level of Salmonella typhi antigen-driven in vitro lymphocyte replication response which signifies specific acquired immunity to this bacterium and to determine the best method of data analysis and form of data presentation. Lymphocyte replication was measured as incorporation of 3H-thymidine into desoxyribonucleic acid. Data (ct/min/culture) were analyzed in raw form and following log transformation, by non-parametric and parametric statistical procedures. A preference was developed for log-transformed data and discriminant analysis. Discriminant analysis of log-transformed data revealed 3H-thymidine incorporation rates greater than 3,433 for particulate S. typhi, Ty2 antigen stimulated cultures signified acquired immunity at a sensitivity and specificity of 82.7; for soluble S. typhi O polysaccharide antigen-stimulated cultures, ct/min/culture values of greater than 1,237 signified immunity (sensitivity and specificity 70.5%). PMID:2702777

Development of real-time PCR assays for the detection of Moraxella macacae associated with bloody nose syndrome in rhesus (Macaca mulatta) and cynomolgus (Macaca fascicularis) macaques

PubMed Central

Whitehouse, Chris A.; Chase, Kitty; Embers, Monica E.; Kulesh, David A.; Ladner, Jason T.; Palacios, Gustavo F.; Minogue, Timothy D.

2016-01-01

Background Moraxella macacae is a recently described bacterial pathogen that causes epistaxis or so-called bloody nose syndrome in captive macaques. The aim of this study was to develop specific molecular diagnostic assays for M. macacae and to determine their performance characteristics. Methods We developed six real-time PCR assays on the Roche LightCycler. The accuracy, precision, selectivity, and limit of detection (LOD) were determined for each assay, in addition to further validation by testing nasal swabs from macaques presenting with epistaxis at the Tulane National Primate Research Center. Results All assays exhibited 100% specificity and were highly sensitive with an LOD of 10 fg for chromosomal assays and 1 fg for the plasmid assay. Testing of nasal swabs from 10 symptomatic macaques confirmed the presence of M. macacae in these animals. Conclusions We developed several accurate, sensitive, and species-specific real-time PCR assays for the detection of M. macacae in captive macaques. PMID:26365904

Interindividual differences of corneal sensitivity. Genetic aspects.

PubMed

Draeger, J; Schloot, W; Wirt, H

1985-08-01

By means of an electronic optical esthesiometer corneal sensitivity was examined in 91 volunteers of different age groups. Additionally, the anesthetic duration of the local anesthetic benoxinate was investigated. Corneal sensitivity decreases with advancing age. Comparing male and female subjects, we can suppose that there are age and sex specific differences of corneal sensitivity. There might be additional genetic factors. There are great interindividual differences in the anesthetic duration of benoxinate. It can be assumed that benoxinate is metabolized by pseudocholinesterase. One possible explanation for the great differences in the anesthetic duration of benoxinate can be seen in the genetically determined variants of pseudocholinesterase.

[Sensitivity and specificity of prick skin test with two concentrations of standardized extract of Culex quinquefasciatus in allergic children].

PubMed

Castro-Almarales, Raúl Lázaro; Álvarez-Castelló, Mirta; Ronquillo-Díaz, Mercedes; Rodríguez-Canosa, José S; González-León, Mayda; Navarro-Viltre, Bárbara I; Betancourt-Mesia, Daniel; Enríquez-Domínguez, Irene; Reyes-Zamora, Mary Carmen; Oliva-Díaz, Yunia; Mateo-Morejón, Maytee; Labrada-Rosado, Alexis

2016-01-01

Diagnostic options for immune reactions to mosquito bites are limited. In Cuba, IgE-mediated reactions are frequently related to Culex quinquefasciatus bite. To determine the sensitivity and specificity of skin prick test with two doses of standardized extract in nitrogen protein units (PNU of Culex quinquefasciatus (BIOCEN, Cuba). An analytical study was conducted on 100 children between 2 and 15 years old. Fifty atopic patients with a history of allergy to mosquito bite and positive specific serum IgE Culex quinquefasciatus and fifty atopic patients without a history of allergy to mosquito bite and negative specific serum IgE to Culex quinquefasciatus. Skin prick tests (SPT) were performed by duplicates on the forearms of the patients. Investigated doses were 100 PNU/mL and 10 PNU/mL. SPT with the highest concentration obtained a mean wheal size of 22.09 mm2 and for lower doses of 8.09 mm2, a statistically significant difference (p=0.001, Student's t test). Positive skin test correlated in 100% of patients with the presence of specific IgE. Testing with both doses showed a 94% of specificity and 88% of sensitivity. The diagnostic accuracy of SPT using both doses of standardized extract was similar, which justifies its use for diagnosis of sensitization to Culex quinquefasciatus in patients with symptoms of allergy to mosquito bite.

Application of support vector machine method for the analysis of absorption spectra of exhaled air of patients with broncho-pulmonary diseases

NASA Astrophysics Data System (ADS)

Bukreeva, Ekaterina B.; Bulanova, Anna A.; Kistenev, Yury V.; Kuzmin, Dmitry A.; Tuzikov, Sergei A.; Yumov, Evgeny L.

2014-11-01

The results of the joint use of laser photoacoustic spectroscopy and chemometrics methods in gas analysis of exhaled air of patients with respiratory diseases (chronic obstructive pulmonary disease, pneumonia and lung cancer) are presented. The absorption spectra of exhaled breath of all volunteers were measured, the classification methods of the scans of the absorption spectra were applied, the sensitivity/specificity of the classification results were determined. It were obtained a result of nosological in pairs classification for all investigated volunteers, indices of sensitivity and specificity.

Intrauterine sensitization of allergen-specific IgE analyzed by a highly sensitive new allergen microarray.

PubMed

Kamemura, Norio; Tada, Hitomi; Shimojo, Naoki; Morita, Yoshinori; Kohno, Yoichi; Ichioka, Takao; Suzuki, Koichi; Kubota, Kenji; Hiyoshi, Mineyoshi; Kido, Hiroshi

2012-07-01

To design a rational allergy prevention program, it is important to determine whether allergic sensitization starts in utero under the maternal immune system. To investigate the origin of allergen-specific IgE antibodies in cord blood (CB) and maternofetal transfer of immunoglobulins. The levels of food and inhalant allergen-specific IgE, IgA, IgG, and IgG(4) antibodies in CB and maternal blood (MB) from 92 paired neonates and mothers were measured by using a novel allergen microarray of diamond-like-carbon-coated chip, with high-sensitivity detection of allergen-specific antibodies and allergen profiles. The levels of allergen-specific IgE antibodies against food and inhalant allergens and allergen profiles were identical in CB and newborn blood, but the levels and profiles, specifically against inhalant allergens, were different from those in MB. The level of allergen-specific IgA antibodies was below the detection levels in CB despite clear detection in MB. Therefore, contamination with MB in CB was excluded on the basis of extremely low levels of IgA antibodies in CB and the obvious mismatch of the allergen-specific IgE and IgA profiles between CB and MB. However, the levels of allergen-specific IgG and IgG(4) antibodies and their allergen profiles were almost identical in both MB and CB. Allergen-specific levels of IgE and IgA antibodies and their allergen profiles analyzed by the diamond-like-carbon allergen chip indicate that IgE antibodies in CB are of fetal origin. Food-allergen specific IgE antibodies were detected more often than inhalant-allergen specific IgE antibodies in CB, the reason of which remains unclarified. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Discrimination of skin sensitizers from non-sensitizers by interleukin-1α and interleukin-6 production on cultured human keratinocytes.

PubMed

Jung, Daun; Che, Jeong-Hwan; Lim, Kyung-Min; Chun, Young-Jin; Heo, Yong; Seok, Seung Hyeok

2016-09-01

In vitro testing methods for classifying sensitizers could be valuable alternatives to in vivo sensitization testing using animal models, such as the murine local lymph node assay (LLNA) and the guinea pig maximization test (GMT), but there remains a need for in vitro methods that are more accurate and simpler to distinguish skin sensitizers from non-sensitizers. Thus, the aim of our study was to establish an in vitro assay as a screening tool for detecting skin sensitizers using the human keratinocyte cell line, HaCaT. HaCaT cells were exposed to 16 relevant skin sensitizers and 6 skin non-sensitizers. The highest dose used was the dose causing 75% cell viability (CV75) that we determined by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The levels of extracellular production of interleukin-1α (IL-1α) and IL-6 were measured. The sensitivity of IL-1α was 63%, specificity was 83% and accuracy was 68%. In the case of IL-6, sensitivity: 69%, specificity: 83% and accuracy: 73%. Thus, this study suggests that measuring extracellular production of pro-inflammatory cytokines IL-1α and IL-6 by human HaCaT cells may potentially classify skin sensitizers from non-sensitizers. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Sensitivity and specificity of waist circumference as a single screening tool for identification of overweight and obesity among Malaysian adults.

PubMed

Kee, C C; Jamaiyah, H; Geeta, A; Ali, Z Ahmad; Safiza, M N Noor; Suzana, S; Khor, G L; Rahmah, R; Jamalludin, A R; Sumarni, M G; Lim, K H; Faudzi, Y Ahmad; Amal, N M

2011-12-01

Generalised obesity and central obesity are risk factors for Type II diabetes mellitus and cardiovascular diseases. Waist circumference (WC) has been suggested as a single screening tool for identification of overweight or obese subjects in lieu of the body mass index (BMI) for weight management in public health program. Currently, the recommended waist circumference cut-off points of > or = 94cm for men and > or =80cm for women (waist action level 1) and > or = 102cm for men and > or = 88cm for women (waist action level 2) used for identification of overweight and obesity are based on studies in Caucasian populations. The objective of this study was to assess the sensitivity and specificity of the recommended waist action levels, and to determine optimal WC cut-off points for identification of overweight or obesity with central fat distribution based on BMI for Malaysian adults. Data from 32,773 subjects (14,982 men and 17,791 women) aged 18 and above who participated in the Third National Health Morbidity Survey in 2006 were analysed. Sensitivity and specificity of WC at waist action level 1 were 48.3% and 97.5% for men; and 84.2% and 80.6% for women when compared to the cut-off points based on BMI > or = 25kg/m2. At waist action level 2, sensitivity and specificity were 52.4% and 98.0% for men, and 79.2% and 85.4% for women when compared with the cut-off points based on BMI (> or = 30 kg/m2). Receiver operating characteristic analyses showed that the appropriatescreening cut-off points for WC to identify subjects with overweight (> or = 25kg/m2) was 86.0cm (sensitivity=83.6%, specificity=82.5%) for men, and 79.1cm (sensitivity=85.0%, specificity=79.5%) for women. Waist circumference cut-off points to identify obese subjects (BMI > or = 30 kg/m2) was 93.2cm (sensitivity=86.5%, specificity=85.7%) for men and 85.2cm (sensitivity=77.9%, specificity=78.0%) for women. Our findings demonstrated that the current recommended waist circumference cut-off points have low sensitivity for identification of overweight and obesity in men. We suggest that these newly identified cut-off points be considered.

Determination of 2-isovaleryl-1,3-indandione with 2, 4-dinitro-phenylhydrazine

USGS Publications Warehouse

Menzie, C.M.; Adomaitis, V.A.; Reichel, W.L.

1962-01-01

At present, three 2-alkyl-1,3-indandiones (PMP, pival, and diphacinon) are widely used as rodenticides. Because analytical procedures now in use are empirical and do not furnish adequate or positive means for distinguishing among these closely related compounds, studies were undertaken to develop a sensitive and specific method for the determination of PMP. The relation between KCN and the 2,4-dinitrophenylhydrazone of PMP was investigated and shown to be sensitive and specific. A deeply colored solution is produced with an absorption maximum at 540 mu. This solution obeys Beer?s law over a wide range. The molar absorptivity for the developed color was calculated to be 3.0 X 104. This reaction can be used also as a spot test to detect as little as 1 ug. of PMP.

The salivary microbiota as a diagnostic indicator of oral cancer: a descriptive, non-randomized study of cancer-free and oral squamous cell carcinoma subjects.

PubMed

Mager, D L; Haffajee, A D; Devlin, P M; Norris, C M; Posner, M R; Goodson, J M

2005-07-07

The purpose of the present investigation was to determine if the salivary counts of 40 common oral bacteria in subjects with an oral squamous cell carcinoma (OSCC) lesion would differ from those found in cancer-free (OSCC-free) controls. Unstimulated saliva samples were collected from 229 OSCC-free and 45 OSCC subjects and evaluated for their content of 40 common oral bacteria using checkerboard DNA-DNA hybridization. DNA counts per ml saliva were determined for each species, averaged across subjects in the 2 subject groups, and significance of differences between groups determined using the Mann-Whitney test and adjusted for multiple comparisons. Diagnostic sensitivity and specificity in detection of OSCC by levels of salivary organisms were computed and comparisons made separately between a non-matched group of 45 OSCC subjects and 229 controls and a group of 45 OSCC subjects and 45 controls matched by age, gender and smoking history. Counts of 3 of the 40 species tested, Capnocytophaga gingivalis, Prevotella melaninogenica and Streptococcus mitis, were elevated in the saliva of individuals with OSCC (p < 0.001). When tested as diagnostic markers the 3 species were found to predict 80% of cancer cases (sensitivity) while excluding 83% of controls (specificity) in the non-matched group. Diagnostic sensitivity and specificity in the matched group were 80% and 82% respectively. High salivary counts of C. gingivalis, P. melaninogenica and S. mitis may be diagnostic indicators of OSCC.

[Enzymatic methods in the analysis of musts and wines].

PubMed

Lafon-Lafourcade, S

1978-01-01

The enzymatic methods are based on the property of the enzymes to catalyse specifically and reversibly the conversion of certain metabolites. These methods, developed thanks to the industrial preparation of enzymes, can be applied with no major modification to the analysis of drinks. About 15 constituants of musts and wines can now be determined by these methods. If their cost price was not relatively high, their specificity, sensitivity and rapidity would enable them to compete with the most precise of chemical methods. This is why they are only used in analytic oenology when chemical analysis is most specific enough or too laborious. Enzymatic measurement allows one by its specificity to determine the amount of residual sugar that is fermentable in a dry wine and by its sensitivity to verifie the total disappearance of the malic acid of the wine. Its rapidity must make it preferable to the long and not very specific chemical measurement, especially concerning the determination of citric acid. But glycerol, ethanol and acetic acid can be measured by chemical or chromatographical means with sufficient precision and for a more modest price. In oenology the methods are essentially used for research. They have permitted the study of the combinations of sulphur anhydride in wines (measurement of cetonic acids). The determination of the isomeric nature of the lactic acid produced from sugars by lactic bacteria is based on their application; this determination is a criterium for the identification and classification of these microorganisms. The measurement of the lactic acid during vinification allows the early disclosure of the first effects of a bacterial development; inversely it permits the invalidation of the existence of a lactic sourness, which a high volatile acidity might point to. Lastly, the enzymatic measurement of gluconic acid allows the health of the crop to be controlled.

A rapid spectrophotometric blood cyanide determination applicable to emergency toxicology.

PubMed

Laforge, M; Buneaux, F; Houeto, P; Bourgeois, F; Bourdon, R; Levillain, P

1994-01-01

Cyanide determination in whole blood can be performed by spectrophotometry after using diffusion coupled with coloration by hydroxocobalamin in a Conway dish. The technique may be accelerated by the use of a heating sheet at 45 degrees C. The method proved to be specific, sensitive, and fast, thus permitting measurements in emergency situations.

Assessing sensitivity and specificity of the Manchester Triage System in the evaluation of acute coronary syndrome in adult patients in emergency care: a systematic review.

PubMed

Nishi, Fernanda Ayache; de Oliveira Motta Maia, Flávia; de Souza Santos, Itamar; de Almeida Lopes Monteiro da Cruz, Dina

2017-06-01

Triage is the first assessment and sorting process used to prioritize patients arriving in the emergency department (ED). As a triage tool, the Manchester Triage System (MTS) must have a high sensitivity to minimize the occurrence of under-triage, but must not compromise specificity to avoid the occurrence of overtriage. Sensitivity and specificity of the MTS can be calculated using the frequency of appropriately assigned clinical priority levels for patients presenting to the ED. However, although there are well established criteria for the prioritization of patients with suspected acute coronary syndrome (ACS), several studies have reported difficulties when evaluating patients with this condition. The objective of this review was to synthesize the best available evidence on assessing the sensitivity and specificity of the MTS for screening high-level priority adult patients presenting to the ED with ACS. The current review considered studies that evaluated the use of the MTS in the risk classification of adult patients in the ED. In this review, studies that investigated the priority level, as established by the MTS to screen patients under suspicion of ACS or the sensitivity and specificity of the MTS, for screening patients before the medical diagnosis of ACS were included. This review included both experimental and epidemiological study designs. The results were presented in a narrative synthesis. Six studies were appraised by the independent reviewers. All appraised studies enrolled a consecutive or random sample of patients and presented an overall moderate methodological quality, and all of them were included in this review. A total of 54,176 participants were included in the six studies. All studies were retrospective. Studies included in this review varied in content and data reporting. Only two studies reported sensitivity and specificity values or all the necessary data to calculate sensitivity and specificity. The remaining four studies presented either a sensitivity analysis or the number of true positives and false negatives. However, these four studies were conducted considering only data from patients diagnosed with ACS. Sensitivity values were relatively uniform among the studies: 0.70-0.80. A specificity of 0.59 was reported in the study including only patients with non-traumatic chest pain. On the other hand, in the study that included patients with any complaint, the specificity of MTS to screen patients with ACS was 0.97. The current review demonstrates that the MTS has a moderate sensitivity to evaluate patients with ACS. This may compromise time to treatment in the ED, an important variable in the prognosis of ACS. Atypical presentation of ACS, or high specificity, may also explain the moderate sensitivity demonstrated in this review. However, because of minimal data, it is not possible to confirm this hypothesis. It is difficult to determine the acceptable level of sensitivity or specificity to ensure that a certain triage system is safe.

Performance of rapid tests and algorithms for HIV screening in Abidjan, Ivory Coast.

PubMed

Loukou, Y G; Cabran, M A; Yessé, Zinzendorf Nanga; Adouko, B M O; Lathro, S J; Agbessi-Kouassi, K B T

2014-01-01

Seven rapid diagnosis tests (RDTs) of HIV were evaluated by a panel group who collected serum samples from patients in Abidjan (HIV-1 = 203, HIV-2 = 25, HIV-dual = 25, HIV = 305). Kit performances were recorded after the reference techniques (enzyme-linked immunosorbent assay). The following RDTs showed a sensitivity of 100% and a specificity higher than 99%: Determine, Oraquick, SD Bioline, BCP, and Stat-Pak. These kits were used to establish infection screening strategies. The combination with 2 or 3 of these tests in series or parallel algorithms showed that series combinations with 2 tests (Oraquick and Bioline) and 3 tests (Determine, BCP, and Stat-Pak) gave the best performances (sensitivity, specificity, positive predictive value, and negative predictive value of 100%). However, the combination with 2 tests appeared to be more onerous than the combination with 3 tests. The combination with Determine, BCP, and Stat-Pak tests serving as a tiebreaker could be an alternative to the HIV/AIDS serological screening in Abidjan.

Use of hexyl isocyanate antigen to detect antibodies to hexamethylene diisocyanate (HDI) in sensitized guinea pigs and in a sensitized worker.

PubMed

Karol, M H; Hauth, B A

1982-01-01

Hypersensitivity to hexamethylene diisocyanate (HDI) has been reported following occupational exposure. Diagnosis of sensitivity is usually made from clinical evaluation of symptomatology. An in vitro serologic assay for HDI sensitivity was developed by immunizing guinea pigs with HDI and with hexyl isocyanate (HMI). Animals injected intradermally with HMI produced hapten-specific antibodies whereas guinea pigs injected with HDI produced antibodies specific for larger determinants which included the HDI hapten. The larger determinants were assumed to be composed of portions of "self" molecules which reacted in vivo with HDI. Serum albumin appeared to be one such molecule. No cross reactions were noted between antibodies to HDI and another widely used industrial isocyanate, toluene diisocyanate (TDI). Antigens effective in detecting antibodies to HDI or HMI were tested for ability to detect reaginic antibodies in a worker with clinical "HDI" asthma. Using a radioimmunoassay (RAST), antibodies reacted with conjugates containing either HDI or HMI as haptens. In addition, the prevalance of HDI polyisocyanates (Desmodur N) in spray paints prompted its use as a hapten. Antibodies reacted with Desmodur N antigen conjugates in RAST. RAST inhibition further indicated that Desmodur N antigen reacted more readily with the patient's antibodies than did HDI or HMI antigens. These results suggest that the patient may have been exposed to HDI polyisocyanates in spray paint application. Use of Rast inhibition for diagnosis of sensitivity may indicate the precise sensitizing agent within a mixture.

Rotator cuff crepitus: could Codman really feel a cuff tear?

PubMed

Ponce, Brent A; Kundukulam, Joseph A; Sheppard, Evan D; Determann, Jason R; McGwin, Gerald; Narducci, Carl A; Crowther, Marshall J

2014-07-01

The objective of this study was to assess the accuracy of palpating crepitus to diagnose rotator cuff tears. Seventy consecutive consenting patients who presented with shoulder pain and no previous imaging or surgery on the affected shoulder were prospectively enrolled during a 10-month period. A standardized patient history and examination, including the crepitus test, were recorded in addition to obtaining standard radiographs. Additional imaging after initial evaluation was performed with magnetic resonance imaging and interpreted by a musculoskeletal radiologist blinded to the examination findings. Statistical analysis was used to determine sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the crepitus test in the clinical diagnosis of a rotator cuff tear. Sixty-three patients had histories, examinations, and imaging studies available for analysis. The crepitus test had a sensitivity of 67%, specificity of 80%, PPV of 91%, and NPV of 43% for all types of rotator cuff tears. The sensitivity and specificity for full-thickness or high-grade partial tears was 82% and 73%, respectively; the PPV and NPV were 77% and 79%. Increasing age improved accuracy as the presence of crepitus in patients older than 55 years had a sensitivity of 76%, specificity of 100%, PPV of 100%, and NPV of 38%. The crepitus test has a favorable sensitivity, specificity, PPV, and NPV to assess the integrity of the rotator cuff and may be a useful examination in the clinical diagnosis of a rotator cuff tear. Published by Mosby, Inc.

Reliability of Meat, Fish, Dairy, and Egg Intake Over a 33-Year Interval in Adventist Health Study 2

PubMed Central

Singh, Pramil N.; Batech, Michael; Faed, Pegah; Jaceldo-Siegl, Karen; Martins, Marcia; Fraser, Gary E.

2015-01-01

We studied Adventist Health Study 2 (AHS-2) cohort members to determine the reliability of long-term recall of adult dietary intake that occurred 33 years ago. Establishing the reliability of these measures supports studies of how dietary exposure across the life course affects risk of cancer and other noncommunicable disease outcomes. Among 1816 AHS-2 cohort members, we conducted a statistical comparison of long-term recall of meat, fish, dairy, and eggs at AHS-2 baseline with their report of current diet 33 years before AHS-2 baseline at an age of 30–60 years. Major findings are as follows: 1) a high correlation for frequency of red meat (R = 0.71), poultry (R = 0.67), and fish (R = 0.60); lower correlations for dairy (R = 0.19) and eggs (R = 0.28); 2) good concordance for dichotomous measures of red meat [sensitivity: 0.70; specificity: 0.92; positive predictive value (PPV): 0.91], poultry (sensitivity: 0.76; specificity: 0.87; PPV: 0.83), fish (sensitivity: 0.61; specificity: 0.93; PPV: 0.89), dairy (sensitivity: 0.95; specificity: 0.57; PPV: 0.99), and eggs (sensitivity: 0.95; specificity: 0.41; PPV: 0.96); negative predictive value for dairy and eggs was poor. Among older AHS-2 cohort members, we found good reliability of recall of red meat, poultry, and fish intake that occurred 33 years earlier. PMID:25298211

Diagnostic Accuracy of Abdominal Ultrasound for Diagnosis of Acute Appendicitis: Systematic Review and Meta-analysis.

PubMed

Giljaca, Vanja; Nadarevic, Tin; Poropat, Goran; Nadarevic, Vesna Stefanac; Stimac, Davor

2017-03-01

To determine the diagnostic accuracy of abdominal ultrasound (US) for the diagnosis of acute appendicitis (AA), in terms of sensitivity, specificity and post-test probabilities for positive and negative result. A systematic search of MEDLINE, Embase, The Cochrane library and Science Citation Index Expanded from January 1994 to October 2014 was performed. Two authors independently evaluated studies for inclusion, extracted data and performed analyses. The reference standard for evaluation of final diagnosis was pathohistological report on tissue obtained at appendectomy. Summary sensitivity, specificity and post-test probability of AA after positive and negative result of US with corresponding 95% confidence intervals (CI) were calculated. Out of 3306 references identified through electronic searches, 17 reports met the inclusion criteria, with 2841 included participants. The summary sensitivity and specificity of US for diagnosis of AA were 69% (95% CI 59-78%) and 81% (95% CI 73-88%), respectively. At the median pretest probability of AA of 76.4%, the post-test probability for a positive and negative result of US was 92% (95% CI 88-95%) and 55% (95% CI 46-63%), respectively. Abdominal ultrasound does not seem to have a role in the diagnostic pathway for diagnosis of AA in suspected patients. The summary sensitivity and specificity of US do not exceed that of physical examination. Patients that require additional diagnostic workup should be referred to more sensitive and specific diagnostic procedures, such as computed tomography.

Computer-aided dermoscopy for diagnosis of melanoma

PubMed Central

Barzegari, Masoomeh; Ghaninezhad, Haiedeh; Mansoori, Parisa; Taheri, Arash; Naraghi, Zahra S; Asgari, Masood

2005-01-01

Background Computer-aided dermoscopy using artificial neural networks has been reported to be an accurate tool for the evaluation of pigmented skin lesions. We set out to determine the sensitivity and specificity of a computer-aided dermoscopy system for diagnosis of melanoma in Iranian patients. Methods We studied 122 pigmented skin lesions which were referred for diagnostic evaluation or cosmetic reasons. Each lesion was examined by two clinicians with naked eyes and all of their clinical diagnostic considerations were recorded. The lesions were analyzed using a microDERM® dermoscopy unit. The output value of the software for each lesion was a score between 0 and 10. All of the lesions were excised and examined histologically. Results Histopathological examination revealed melanoma in six lesions. Considering only the most likely clinical diagnosis, sensitivity and specificity of clinical examination for diagnosis of melanoma were 83% and 96%, respectively. Considering all clinical diagnostic considerations, the sensitivity and specificity were 100% and 89%. Choosing a cut-off point of 7.88 for dermoscopy score, the sensitivity and specificity of the score for diagnosis of melanoma were 83% and 96%, respectively. Setting the cut-off point at 7.34, the sensitivity and specificity were 100% and 90%. Conclusion The diagnostic accuracy of the dermoscopy system was at the level of clinical examination by dermatologists with naked eyes. This system may represent a useful tool for screening of melanoma, particularly at centers not experienced in the field of pigmented skin lesions. PMID:16000171

Diagnostic value of sputum adenosine deaminase (ADA) level in pulmonary tuberculosis.

PubMed

Binesh, Fariba; Jalali, Hadi; Zare, Mohammad Reza; Behravan, Farhad; Tafti, Arefeh Dehghani; Behnaz, Fatemah; Tabatabaee, Mohammad; Shahcheraghi, Seyed Hossein

2016-06-01

Tuberculosis is still a considerable health problem in many countries. Rapid diagnosis of this disease is important, and adenosine deaminase (ADA) has been used as a diagnostic test. The aim of this study was to assess the diagnostic value of ADA in the sputum of patients with pulmonary tuberculosis. The current study included 40 patients with pulmonary tuberculosis (culture positive, smear ±) and 42 patients with non tuberculosis pulmonary diseases (culture negative). ADA was measured on all of the samples. The median value of ADA in non-tuberculosis patients was 2.94 (4.2) U/L and 4.01 (6.54) U/L in tuberculosis patients, but this difference was not statistically significant (p=0.100). The cut-off point of 3.1 U/L had a sensitivity of 61% and a specificity of 53%, the cut-off point of 2.81 U/L had a sensitivity of 64% and a specificity of 50% and the cut-off point of 2.78 U/L had a sensitivity of 65% and a specificity of 48%. The positive predictive values for cut-off points of 3.1, 2.81 and 2.78 U/L were 55.7%, 57.44% and 69.23%, respectively. The negative predictive values for the abovementioned cut-off points were 56.75%, 57.14% and 55.88%, respectively. Our results showed that sputum ADA test is neither specific nor sensitive. Because of its low sensitivity and specificity, determination of sputum ADA for the diagnosis of pulmonary tuberculosis is not recommended.

Applying Classification Trees to Hospital Administrative Data to Identify Patients with Lower Gastrointestinal Bleeding

PubMed Central

Siddique, Juned; Ruhnke, Gregory W.; Flores, Andrea; Prochaska, Micah T.; Paesch, Elizabeth; Meltzer, David O.; Whelan, Chad T.

2015-01-01

Background Lower gastrointestinal bleeding (LGIB) is a common cause of acute hospitalization. Currently, there is no accepted standard for identifying patients with LGIB in hospital administrative data. The objective of this study was to develop and validate a set of classification algorithms that use hospital administrative data to identify LGIB. Methods Our sample consists of patients admitted between July 1, 2001 and June 30, 2003 (derivation cohort) and July 1, 2003 and June 30, 2005 (validation cohort) to the general medicine inpatient service of the University of Chicago Hospital, a large urban academic medical center. Confirmed cases of LGIB in both cohorts were determined by reviewing the charts of those patients who had at least 1 of 36 principal or secondary International Classification of Diseases, Ninth revision, Clinical Modification (ICD-9-CM) diagnosis codes associated with LGIB. Classification trees were used on the data of the derivation cohort to develop a set of decision rules for identifying patients with LGIB. These rules were then applied to the validation cohort to assess their performance. Results Three classification algorithms were identified and validated: a high specificity rule with 80.1% sensitivity and 95.8% specificity, a rule that balances sensitivity and specificity (87.8% sensitivity, 90.9% specificity), and a high sensitivity rule with 100% sensitivity and 91.0% specificity. Conclusion These classification algorithms can be used in future studies to evaluate resource utilization and assess outcomes associated with LGIB without the use of chart review. PMID:26406318

Diagnostic Value of Cerebrospinal Fluid T-SPOT.TB for Tuberculousis Meningitis in China.

PubMed

Li, Xue Lian; Xie, Na; Wang, Song Wang; Wu, Qian Hong; Ma, Yan; Shu, Wei; Chen, Hong Mei; Zhang, Li Qun; Wu, Xiao Guang; Ma, Li Ping; Che, Nan Ying; Gao, Meng Qiu

2017-09-01

The aim of this study was to evaluate the diagnostic value of the cerebrospinal fluid (CSF) T-SPOT.TB test for the diagnosis of TB meningitis (TBM). A retrospective analysis of 96 patients with manifested meningitis was conducted; T-SPOT.TB test was performed for diagnosing TBM to determine the diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). A receiver operating characteristic (ROC) curve was also drawn to assess the diagnostic accuracy. The sensitivity, specificity, PPV, and NPV of CSF T-SPOT.TB test were 97.8%, 78.0%, 80.3%, and 97.5%, respectively, for 52 patients (54.2%) of the 96 enrolled patients. The area under the curve (AUC) was 0.910, and the sensitivities of CSF T-SPOT.TB for patients with stages I, II, and III of TBM were 96.7%, 97.2%, and 98.9%, respectively. CSF T-SPOT.TB test is a rapid and accurate diagnostic method with higher sensitivity and specificity for diagnosing TBM. Copyright © 2017 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Molecular Detection and Species-Specific Identification of Medically Important Aspergillus Species by Real-Time PCR in Experimental Invasive Pulmonary Aspergillosis ▿

PubMed Central

Walsh, Thomas J.; Wissel, Mark C.; Grantham, Kevin J.; Petraitiene, Ruta; Petraitis, Vidmantas; Kasai, Miki; Francesconi, Andrea; Cotton, Margaret P.; Hughes, Johanna E.; Greene, Lora; Bacher, John D.; Manna, Pradip; Salomoni, Martin; Kleiboeker, Steven B.; Reddy, Sushruth K.

2011-01-01

Diagnosis of invasive pulmonary aspergillosis (IPA) remains a major challenge to clinical microbiology laboratories. We developed rapid and sensitive quantitative PCR (qPCR) assays for genus- and species-specific identification of Aspergillus infections by use of TaqMan technology. In order to validate these assays and understand their potential diagnostic utility, we then performed a blinded study of bronchoalveolar lavage (BAL) fluid specimens from well-characterized models of IPA with the four medically important species. A set of real-time qPCR primers and probes was developed by utilizing unique ITS1 regions for genus- and species-specific detection of the four most common medically important Aspergillus species (Aspergillus fumigatus, A. flavus, A. niger, and A. terreus). Pan-Aspergillus and species-specific qPCRs with BAL fluid were more sensitive than culture for detection of IPA caused by A. fumigatus in untreated (P < 0.0007) and treated (P ≤ 0.008) animals, respectively. For infections caused by A. terreus and A. niger, culture and PCR amplification from BAL fluid yielded similar sensitivities for untreated and treated animals. Pan-Aspergillus PCR was more sensitive than culture for detection of A. flavus in treated animals (P = 0.002). BAL fluid pan-Aspergillus and species-specific PCRs were comparable in sensitivity to BAL fluid galactomannan (GM) assay. The copy numbers from the qPCR assays correlated with quantitative cultures to determine the pulmonary residual fungal burdens in lung tissue. Pan-Aspergillus and species-specific qPCR assays may improve the rapid and accurate identification of IPA in immunocompromised patients. PMID:21976757

Urinary neutrophil gelatinase-associated lipocalin for diagnosis and estimating activity in lupus nephritis: a meta-analysis.

PubMed

Fang, Y G; Chen, N N; Cheng, Y B; Sun, S J; Li, H X; Sun, F; Xiang, Y

2015-12-01

Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is relatively specific in lupus nephritis (LN) patients. However, its diagnostic value has not been evaluated. The aim of this review was to determine the value of uNGAL for diagnosis and estimating activity in LN. A comprehensive search was performed on PubMed, EMBASE, Web of Knowledge, Cochrane electronic databases through December 2014. Meta-analysis of sensitivity and specificity was performed with a random-effects model. Additionally, summary receiver operating characteristic (SROC) curves and area under the curve (AUC) values were calculated. Fourteen studies were selected for this review. With respect to diagnosing LN, the pooled sensitivity and specificity were 73.6% (95% confidence interval (CI), 61.9-83.3) and 78.1% (95% CI, 69.0-85.6), respectively. The SROC-AUC value was 0.8632. Regarding estimating LN activity, the pooled sensitivity and specificity were 66.2% (95% CI, 60.4-71.7) and 62.1% (95% CI, 57.9-66.3), respectively. The SROC-AUC value was 0.7583. In predicting renal flares, the pooled sensitivity and specificity were 77.5% (95% CI, 68.1-85.1) and 65.3% (95% CI, 60.0-70.3), respectively. The SROC-AUC value was 0.7756. In conclusion, this meta-analysis indicates that uNGAL has relatively fair sensitivity and specificity in diagnosing LN, estimating LN activity and predicting renal flares, suggesting that uNGAL is a potential biomarker in diagnosing LN and monitoring LN activity. © The Author(s) 2015.

The immunogenicity of cephalosporin derivatives and their cross-reaction with penicillin

PubMed Central

Batchelor, F. R.; Dewdney, Janet M.; Weston, R. D.; Wheeler, A. W.

1966-01-01

Cephalothin and cephaloridine, antibiotics with the 7-amino cephalosporanic acid nucleus, have been shown to form protein conjugates which were able to stimulate production of haemagglutinating, precipitating and guinea-pig skin-sensitizing antibodies in the rabbit. A high degree of cross-reaction with the benzyl penicilloyl determinant group was demonstrated, but evidence was found of only very limited cross-reaction with the haptenic determinant of the penicillin nucleus, 6-amino penicillanic acid. Cephalothin did not induce contact sensitivity in guinea-pigs. These results are discussed with particular respect to the relative parts which the side chain and nucleus of these related antibiotics play in determining antigenic specificity. PMID:4160334

Evaluation of sensitivity and specificity of a standardized procedure using different reagents for the detection of lupus anticoagulants. The Working Group on Hemostasis of the Société Française de Biologie Clinique and for the Groupe d'Etudes sur I'Hémostase et la Thrombose.

PubMed

Goudemand, J; Caron, C; De Prost, D; Derlon, A; Borg, J Y; Sampol, J; Sié, P

1997-02-01

This study was designed to test the sensitivity and specificity of a combination of 3 phospholipid-dependent assays performed with various reagents, for the detection of lupus anticoagulant (LA). Plasmas containing an LA (n = 56) or displaying various confounding pathologies [58 intrinsic pathway factor deficiencies, 9 factor VIII inhibitors, 28 plasmas from patients treated with an oral anticoagulant (OAC)] were selected. In a first step, the efficiency of each assay and reagent was assessed using the Receiving Operating Characteristic (ROC) method. Optimal cut-offs providing both sensitivity and specificity > or = 80% were determined. The APTT assay and most of the phospholipid neutralization assays failed to discriminate factor VIII inhibitors from LA. In a second step, using the optimal cut-offs determined above, the results of all the possible combinations of the 3 assays performed with 4 different reagents were analyzed. Thirteen combinations of reagents allowed > or = 80% of plasmas of each category (LA, factor deficiency or OAC) to be correctly classified (3/3 positive test results in LA-containing plasmas and 0/3 positive results in LA-negative samples).

Prospective, multicenter clinical trial to validate new products for skin tests in the diagnosis of allergy to penicillin.

PubMed

Fernández, J; Torres, M J; Campos, J; Arribas-Poves, F; Blanca, M

2013-01-01

Allergy to penicillin is the most commonly reported type of drug hypersensitivity. Diagnosis is currently confirmed using skin tests with benzylpenicillin reagents, ie, penicilloyl-polylysine (PPL) as the major determinant of benzylpenicillin and benzylpenicillin, benzylpenicilloate and benzylpenilloate as a minor determinant mixture (MDM). To synthesize and assess the diagnostic capacity of 2 new benzylpenicillin reagents in patients with immediate hypersensitivity reactions to B-lactams: benzylpenicilloyl octa-L-lysine (BP-OL) as the major determinant and benzylpenilloate (penilloate) as the minor determinant. Prospective multicenter clinical trial performed in 18 Spanish centers. Efficacy was assessed by detection of positive skin test results in an allergic population and negative skin test results in a nonallergic, drug-exposed population. Sensitivity, specificity, and negative and positive predictive values were determined. The study sample comprised 94 allergic patients: 31 (35.23%) presented anaphylaxis, 4 (4.55%) anaphylactic shock, 51 (58.04%) urticaria, and 2 (2.27%) no specific condition. The culprit 8-lactams were amoxicillin in 63 cases (71.60%), benzypencillin in 14 cases (15.89%), cephalosporins in 2 cases (2.27%), other drugs in 3 cases (3.42%), and unidentified agents in 6 cases (6.82%). The results of testing with BP-OL were positive in 46 cases (52.3%); the results of testing with penilloate were positive in 33 cases (37.5%). When both reagents were taken into consideration, sensitivity reached 61.36% and specificity 100%. Skin testing with penilloate was significantly more often negative when the interval between the reaction and the study was longer. The sensitivity of BP-OL and penilloate was 61%. Considering that amoxicillin was the culprit drug in 71% of reactions, these results indicate that most patients were allergic to the whole group of penicillins. These data support the use of benzylpenicillin determinants in the diagnosis of allergy to beta-lactams, even in predominantly amoxicillin-allergic populations.

Combined determination of circulating miR-196a and miR-196b levels produces high sensitivity and specificity for early detection of oral cancer.

PubMed

Lu, Ya-Ching; Chang, Joseph Tung-Chieh; Huang, Yu-Chen; Huang, Chi-Che; Chen, Wen-Ho; Lee, Li-Yu; Huang, Bing-Shen; Chen, Yin-Ju; Li, Hsiao-Fang; Cheng, Ann-Joy

2015-02-01

The aim of this study was to determine whether the oncogenic microRNA family members miR-196a and miR-196b can be circulating biomarkers for the early detection of oral cancer. To determine the stability of circulating miRNA, the blood sample was aliquot and stored at different temperature conditions for analysis. To assess the diagnostic efficacy, we determined the levels of miR-196s in plasma samples, including 53 from healthy individuals, 16 from pre-cancer patients, and 90 from oral cancer patients. In general, circulating miRNA was very stable when storing plasma samples at -20°C or below. In clinical study, both circulating miR-196a and miR-196b were substantially up-regulated in patients with oral pre-cancer lesions (5.9- and 14.8-fold, respectively; P < 0.01), as well as in oral cancer patients (9.3- and 17.0-fold, respectively; P < 0.01). These results show prominent discrimination between normal and pre-cancer patients (AUC = 0.764 or 0.840, miR-196a or miR-196b, respectively), and between normal and cancer patients (AUC = 0.864 or 0.960, miR-196a or miR-196b, respectively). The combined determination of miR-196a and miR-196b levels produces excellent sensitivity and specificity in the diagnosis of patients with oral pre-cancer (AUC = 0.845) or oral cancer (AUC = 0.963), as well as in the prediction of potential malignancy (AUC = 0.950, sensitivity = 91%, specificity = 85%). Combined determination of circulating miR-196a and miR-196b levels may serve as panel plasma biomarkers for the early detection of oral cancer. Copyright © 2014 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

The diagnostic value of narrow-band imaging for early and invasive lung cancer: a meta-analysis.

PubMed

Zhu, Juanjuan; Li, Wei; Zhou, Jihong; Chen, Yuqing; Zhao, Chenling; Zhang, Ting; Peng, Wenjia; Wang, Xiaojing

2017-07-01

This study aimed to compare the ability of narrow-band imaging to detect early and invasive lung cancer with that of conventional pathological analysis and white-light bronchoscopy. We searched the PubMed, EMBASE, Sinomed, and China National Knowledge Infrastructure databases for relevant studies. Meta-disc software was used to perform data analysis, meta-regression analysis, sensitivity analysis, and heterogeneity testing, and STATA software was used to determine if publication bias was present, as well as to calculate the relative risks for the sensitivity and specificity of narrow-band imaging vs those of white-light bronchoscopy for the detection of early and invasive lung cancer. A random-effects model was used to assess the diagnostic efficacy of the above modalities in cases in which a high degree of between-study heterogeneity was noted with respect to their diagnostic efficacies. The database search identified six studies including 578 patients. The pooled sensitivity and specificity of narrow-band imaging were 86% (95% confidence interval: 83-88%) and 81% (95% confidence interval: 77-84%), respectively, and the pooled sensitivity and specificity of white-light bronchoscopy were 70% (95% confidence interval: 66-74%) and 66% (95% confidence interval: 62-70%), respectively. The pooled relative risks for the sensitivity and specificity of narrow-band imaging vs the sensitivity and specificity of white-light bronchoscopy for the detection of early and invasive lung cancer were 1.33 (95% confidence interval: 1.07-1.67) and 1.09 (95% confidence interval: 0.84-1.42), respectively, and sensitivity analysis showed that narrow-band imaging exhibited good diagnostic efficacy with respect to detecting early and invasive lung cancer and that the results of the study were stable. Narrow-band imaging was superior to white light bronchoscopy with respect to detecting early and invasive lung cancer; however, the specificities of the two modalities did not differ significantly.

Prevalence of and risk factors for latex sensitization in patients with spina bifida.

PubMed

Bernardini, R; Novembre, E; Lombardi, E; Mezzetti, P; Cianferoni, A; Danti, A D; Mercurella, A; Vierucci, A

1998-11-01

We determined the prevalence of and risk factors for latex sensitization in patients with spina bifida. A total of 59 consecutive subjects 2 to 40 years old with spina bifida answered a questionnaire, and underwent a latex skin prick test and determination of serum IgE specific for latex by RAST CAP radioimmunoassay. We also noted the relationships of total serum IgE skin prick tests to common air and food allergens. In addition, skin prick plus prick tests were also done with fresh foods, including kiwi, pear, orange, almond, pineapple, apple, tomato and banana. Latex sensitization was present in 15 patients (25%) according to the presence of IgE specific to latex, as detected by a skin prick test in 9 and/or RAST CAP in 13. Five latex sensitized patients (33.3%) had clinical manifestations, such as urticaria, conjuctivitis, angioedema, rhinitis and bronchial asthma, while using a latex glove and inflating a latex balloon. Atopy was present in 21 patients (35.6%). In 14 patients (23%) 1 or more skin tests were positive for fresh foods using a prick plus prick technique. Tomato, kiwi, and pear were the most common skin test positive foods. Univariate analysis revealed that a history of 5 or more operations, atopy and positive prick plus prick tests results for pear and kiwi were significantly associated with latex sensitization. Multivariate analysis demonstrated that only atopy and a history of 5 or more operations were significantly and independently associated with latex sensitization. A fourth of the patients with spina bifida were sensitized to latex. Atopy and an elevated number of operations were significant and independent predictors of latex sensitization in these cases.

Sensitivity and Specificity of Biochemical Tests for Diagnosis of Intrahepatic Cholestasis of Pregnancy.

PubMed

Jurate, Kondrackiene; Rimantas, Zalinkevicius; Jolanta, Sumskiene; Vladas, Gintautas; Limas, Kupcinskas

2017-01-01

Intrahepatic cholestasis of pregnancy (ICP) is linked with increased risk of fetal complications. An accurate diagnostic test is needed to diagnose this disorder on time. We aimed to assess sensitivity and specificity of laboratory tests used for diagnosis of intrahepatic cholestasis of pregnancy and determine more reliable cut-off values of transaminases. Sixty one symptomatic patients with ICP and 29 healthy pregnant women were included in the retrospective analysis. ICP patients had higher total bile acids (TBA) levels than healthy women (32 vs. 6; P < 0.0001) due to increase in cholic acid (CA) and chenodeoxycholic acid (CDCA). CA/CDCA ratio was significantly higher in ICP patients compared to healthy pregnant women (1.13 vs. 0.68; P < 0.00002). TBA, CA, CDCA and CA/CDCA ratio demonstrate the following sensitivity (94%, 96%, 89%, 71.9%) and specificity (63%, 63%, 59%, 79.3%, respectively) for ICP diagnosis. Lowering cut-off values for ALT (31 U/L) and AST (30 U/L) resulted only in minimal increase of sensitivity to 92.2% vs. 90.1% for ALT and to 92.2%, vs. 90.6% for AST. The present study did not reveal any single specific and sensitive marker for reliable diagnosis of ICP. Establishment of lower cut-off values for transaminases activity might only minimally increase the accuracy of diagnosing ICP.

Grading Dysphagia as a Toxicity of Head and Neck Cancer: Differences in Severity Classification Based on MBS DIGEST and Clinical CTCAE Grades.

PubMed

Goepfert, Ryan P; Lewin, Jan S; Barrow, Martha P; Warneke, Carla L; Fuller, Clifton D; Lai, Stephen Y; Weber, Randal S; Hutcheson, Katherine A

2018-04-01

Clinician-reported toxicity grading through common terminology criteria for adverse events (CTCAE) stages dysphagia based on symptoms, diet, and tube dependence. The new dynamic imaging grade of swallowing toxicity (DIGEST) tool offers a similarly scaled five-point ordinal summary grade of pharyngeal swallowing as determined through results of a modified barium swallow (MBS) study. This study aims to inform clinicians on the similarities and differences between dysphagia severity according to clinical CTCAE and MBS-derived DIGEST grading. A cross-sectional sample of 95 MBS studies was randomly selected from a prospectively-acquired MBS database among patients treated with organ preservation strategies for head and neck cancer. MBS DIGEST and clinical CTCAE dysphagia grades were compared. DIGEST and CTCAE dysphagia grades had "fair" agreement per weighted κ of 0.358 (95% CI .231-.485). Using a threshold of DIGEST ≥ 3 as reference, CTCAE had an overall sensitivity of 0.50, specificity of 0.84, and area under the curve (AUC) of 0.67 to identify severe MBS-detected dysphagia. At less than 6 months, sensitivity was 0.72, specificity was 0.76, and AUC was 0.75 while at greater than 6 months, sensitivity was 0.22, specificity was 0.90, and AUC was 0.56 for CTCAE to detect dysphagia as determined by DIGEST. Classification of pharyngeal dysphagia on MBS using DIGEST augments our understanding of dysphagia severity according to the clinically-derived CTCAE while maintaining the simplicity of an ordinal scale. DIGEST likely complements CTCAE toxicity grading through improved specificity for physiologic dysphagia in the acute phase and improved sensitivity for dysphagia in the late-phase.

Validity of LIDAS (LIfetime Depression Assessment Self-report): a self-report online assessment of lifetime major depressive disorder.

PubMed

Bot, M; Middeldorp, C M; de Geus, E J C; Lau, H M; Sinke, M; van Nieuwenhuizen, B; Smit, J H; Boomsma, D I; Penninx, B W J H

2017-01-01

There is a paucity of valid, brief instruments for the assessment of lifetime major depressive disorder (MDD) that can be used in, for example, large-scale genomics, imaging or biomarker studies on depression. We developed the LIfetime Depression Assessment Self-report (LIDAS), which assesses lifetime MDD diagnosis according to DSM criteria, and is largely based on the widely used Composite International Diagnostic Interview (CIDI). Here, we tested the feasibility and determined the sensitivity and specificity for measuring lifetime MDD with this new questionnaire, with a regular CIDI as reference. Sensitivity and specificity analyses of the online lifetime MDD questionnaire were performed in adults with (n = 177) and without (n = 87) lifetime MDD according to regular index CIDIs, selected from the Netherlands Study of Depression and Anxiety (NESDA) and Netherlands Twin Register (NTR). Feasibility was tested in an additional non-selective, population-based sample of NTR participants (n = 245). Of the 753 invited persons, 509 (68%) completed the LIDAS, of which 419 (82%) did this online. User-friendliness of the instrument was rated high. Median completion time was 6.2 min. Sensitivity and specificity for lifetime MDD were 85% [95% confidence interval (CI) 80-91%] and 80% (95% CI 72-89%), respectively. This LIDAS instrument gave a lifetime MDD prevalence of 20.8% in the population-based sample. Measuring lifetime MDD with an online instrument was feasible. Sensitivity and specificity were adequate. The instrument gave a prevalence of lifetime MDD in line with reported population prevalences. LIDAS is a promising tool for rapid determination of lifetime MDD status in large samples, such as needed for genomics studies.

Evaluation of the Recombinant Protein TpF1 of Treponema pallidum for Serodiagnosis of Syphilis

PubMed Central

Jiang, Chuanhao; Zhao, Feijun; Xiao, Jinhong; Zeng, Tiebing; Yu, Jian; Ma, Xiaohua; Wu, Haiying

2013-01-01

Syphilis is a chronic infection caused by Treponema pallidum subsp. pallidum, and diagnosis with sensitive and specific methods is a challenging process that is important for its prevention and treatment. In the present study, we established a recombinant protein TpF1-based indirect immunoglobulin G (IgG) enzyme-linked immunosorbent assay (ELISA) and a Western blot assay for human and rabbit sera. The 20-kDa recombinant protein TpF1 was detected by Western blotting performed with sera from rabbits immunized with recombinant TpF1 and infected with the T. pallidum Nichols strain and T. pallidum clinical isolates but was not detected by Western blotting with sera from uninfected rabbits. The sensitivity of the recombinant protein was determined by screening sera from individuals with primary, secondary, latent, and congenital syphilis (n = 82). The specificity of the recombinant protein was determined by screening sera from uninfected controls (n = 30) and individuals with potentially cross-reactive infections, including Lyme disease (n = 30) and leptospirosis (n = 5). The sensitivities of TpF1-based ELISAs were 93.3%, 100%, 100%, and 100% for primary, secondary, latent, and congenital syphilis, respectively, and the specificities were all 100% for sera from uninfected controls and individuals with potentially cross-reactive infections. In Western blot assays, the sensitivities and specificities of TpF1 for human sera were all 100%. The reactivities of TpF1 with syphilitic sera were proportional to the titers of the T. pallidum particle agglutination (TPPA) assay. These data indicate that the recombinant protein TpF1 is a highly immunogenic protein in human and rabbit infections and a promising marker for the screening of syphilis. PMID:23945159

Cytomegalovirus cultured from different major leukocyte subpopulations: association with clinical features in CMV immunoglobulin G-positive renal allograft recipients.

PubMed

Schäfer, P; Tenschert, W; Cremaschi, L; Schröter, M; Gutensohn, K; Laufs, R

2000-08-01

Cytomegalovirus (CMV) cultured from peripheral blood mononuclear cells (PBMCs) was shown to be associated more closely with clinical manifestations than infectious CMV in polymorphonuclear leukocytes (PMNLs) of renal allograft recipients with secondary CMV infection. Shell vial culture was carried out with ficoll-purified PBMCs and PMNLs of 71 CMV IgG-positive patients after kidney transplantation. Thirty-six patients experienced active CMV infections. Of these, 17 developed clinical symptoms. The diagnostic value of PMNLs and PBMCs viremia was determined in comparison to pp65 antigenemia, leukoDNAemia, plasma DNAemia, and detection of cytomegalic endothelial cells. In both PMNLs and PBMCs (with or without detectable endothelial cells), frequencies and levels of viremia were significantly higher among symptomatic patients. Regarding the occurrence of clinical CMV manifestations, the sensitivity of culture from PMNLs and from PBMCs fractions was 100%. Viremia in PBMCs, however, was far more specific (94%) than in PMNLs (74%). Cutoff values established previously for pp65 antigenemia and leukoDNAemia, standard markers in the laboratory, had similar specificity (96% each) to PBMCs viremia, but were less sensitive (88% each). Plasma DNA-emia was both less sensitive (82%) and less specific (69%) than PBMCs viremia. Detection of endothelemia showed maximal specificity (100%), but inferior sensitivity (47%). All patients had PBMCs viremia before the onset of symptoms. In conclusion, infectious CMV present in PBMCs may prove to be a determinant of clinical CMV manifestations in seropositive immunocompromised individuals. Factors involved in PBMCs tropism may help to understand the pathogenetic mechanisms of CMV dissemination in this group of patients. Copyright 2000 Wiley-Liss, Inc.

ROC-ing along: Evaluation and interpretation of receiver operating characteristic curves.

PubMed

Carter, Jane V; Pan, Jianmin; Rai, Shesh N; Galandiuk, Susan

2016-06-01

It is vital for clinicians to understand and interpret correctly medical statistics as used in clinical studies. In this review, we address current issues and focus on delivering a simple, yet comprehensive, explanation of common research methodology involving receiver operating characteristic (ROC) curves. ROC curves are used most commonly in medicine as a means of evaluating diagnostic tests. Sample data from a plasma test for the diagnosis of colorectal cancer were used to generate a prediction model. These are actual, unpublished data that have been used to describe the calculation of sensitivity, specificity, positive predictive and negative predictive values, and accuracy. The ROC curves were generated to determine the accuracy of this plasma test. These curves are generated by plotting the sensitivity (true-positive rate) on the y axis and 1 - specificity (false-positive rate) on the x axis. Curves that approach closest to the coordinate (x = 0, y = 1) are more highly predictive, whereas ROC curves that lie close to the line of equality indicate that the result is no better than that obtained by chance. The optimum sensitivity and specificity can be determined from the graph as the point where the minimum distance line crosses the ROC curve. This point corresponds to the Youden index (J), a function of sensitivity and specificity used commonly to rate diagnostic tests. The area under the curve is used to quantify the overall ability of a test to discriminate between 2 outcomes. By following these simple guidelines, interpretation of ROC curves will be less difficult and they can then be interpreted more reliably when writing, reviewing, or analyzing scientific papers. Copyright © 2016 Elsevier Inc. All rights reserved.

[Diagnostic values of plasma CD64 and sTREM-1 for pediatric pneumonia].

PubMed

Zhong, Mei-Feng; Zhao, Jian-Mei

2016-07-01

To determine the diagnostic values of plasma CD64 and soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) in children with pneumonia. Sixty children with pneumonia between August 2014 and October 2015 were classified into bacterial pneumonia group (25 cases), viral pneumonia group (17 cases), and Mycoplasma pneumonia group (18 cases) according to their clinical manifestations, pathogen cultures, and X-ray findings. Another 30 healthy children who underwent physical examination during the same period were selected as the control group. The concentrations of CD64 and sTREM-1 in blood samples were determined using ELISA. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic sensitivity and specificity of plasma CD64 and/or sTREM-1 for bacterial pneumonia. The expression of CD64 and sTREM-1 in the bacterial pneumonia group was significantly higher than that in the viral pneumonia, Mycoplasma pneumonia, and control groups (P<0.05). The areas under the ROC curves of CD64, sTREM-1, and a combination of the two markers for diagnosing bacterial pneumonia were 0.878, 0.805, and 0.956, respectively. The sensitivity and specificity of CD64 for diagnosing bacterial pneumonia were 81.30% and 92.32%, respectively, when the cut-off value was 641 pg/mL. The sensitivity and specificity of sTREM-1 for diagnosing bacterial pneumonia were 78.65% and 84.67%, respectively, when the cut-off value was 1 479 pg/mL. The sensitivity and specificity of a combination of the two markers for diagnosing bacterial pneumonia were 93.15% and 91.54%, respectively. Plasma CD64 and sTREM-1 can be used as markers for diagnosing pediatric bacterial pneumonia, and a combination of the two markers results in better diagnosis.

Sensitivity, Specificity, Predictive Values, and Accuracy of Three Diagnostic Tests to Predict Inferior Alveolar Nerve Blockade Failure in Symptomatic Irreversible Pulpitis

PubMed Central

Rodríguez-Wong, Laura; Noguera-González, Danny; Esparza-Villalpando, Vicente; Montero-Aguilar, Mauricio

2017-01-01

Introduction The inferior alveolar nerve block (IANB) is the most common anesthetic technique used on mandibular teeth during root canal treatment. Its success in the presence of preoperative inflammation is still controversial. The aim of this study was to evaluate the sensitivity, specificity, predictive values, and accuracy of three diagnostic tests used to predict IANB failure in symptomatic irreversible pulpitis (SIP). Methodology A cross-sectional study was carried out on the mandibular molars of 53 patients with SIP. All patients received a single cartridge of mepivacaine 2% with 1 : 100000 epinephrine using the IANB technique. Three diagnostic clinical tests were performed to detect anesthetic failure. Anesthetic failure was defined as a positive painful response to any of the three tests. Sensitivity, specificity, predictive values, accuracy, and ROC curves were calculated and compared and significant differences were analyzed. Results IANB failure was determined in 71.7% of the patients. The sensitivity scores for the three tests (lip numbness, the cold stimuli test, and responsiveness during endodontic access) were 0.03, 0.35, and 0.55, respectively, and the specificity score was determined as 1 for all of the tests. Clinically, none of the evaluated tests demonstrated a high enough accuracy (0.30, 0.53, and 0.68 for lip numbness, the cold stimuli test, and responsiveness during endodontic access, resp.). A comparison of the areas under the curve in the ROC analyses showed statistically significant differences between the three tests (p < 0.05). Conclusion None of the analyzed tests demonstrated a high enough accuracy to be considered a reliable diagnostic tool for the prediction of anesthetic failure. PMID:28694714

Comparative assessment of recombinant and native immunogenic forms of Fasciola hepatica proteins for serodiagnosis of sheep fasciolosis.

PubMed

Mokhtarian, Kobra; Meamar, Ahmad Reza; Khoshmirsafa, Majid; Razmjou, Elham; Masoori, Leila; Khanmohammadi, Majid; Akhlaghi, Lame; Falak, Reza

2018-01-01

Laboratory diagnosis of sheep fasciolosis is commonly performed by coprological examinations; however, this method may lead to false negative results during the acute phase of the infection. Furthermore, the poor sensitivity of coprological methods is considered to be a paradox in the chronic phase of the infection. In this study, we compared the immunoreactivity of native and recombinant forms of Fasciola hepatica excretory/secretory antigens and determined their capabilities for the development of F. hepatica-specific immunoassays. Immunoreactivity and specificity of recombinant and native forms of F. hepatica antigens, including fatty acid binding protein (FABP), glutathione-S-transferase (GST), and cathepsin L-1 (CL1), in parallel with native forms of FABP and GST, were studied for serodiagnosis of the chronic form of sheep fasciolosis, individually or in combination with each other by enzyme-linked immunosorbent assays (ELISA). The correlation of the findings was assessed by receiver-operator characteristic (ROC); furthermore, the specificity and sensitivity were assessed by Youden's J. Serologic cross-reactivity was evaluated using samples from healthy sheep (n = 40), Fasciola-infected sheep (n = 30), and sheep with other parasitic infections (n = 43). The FABPs were determined to be greater than 95% sensitive for F. hepatica serodiagnosis. The most desirable diagnostic recombinant antigen was rCL1, which showed 100% sensitivity and 97% specificity in ELISA and was capable of discriminating the positive and negative samples by maximum Youden's J results. We conclude that rCL1 can be used for routine serodiagnosis of chronic fasciolosis. Thus, it could be advantageous in development of immunoassays for screening of ovine herds in fasciolosis-endemic areas and as a reliable agent for detection of fasciolosis in non-endemic regions.

Sensitivity and specificity of the amer dizziness diagnostic scale (adds) for patients with vestibular disorders.

PubMed

Al Saif, Amer; Alsenany, Samira

2015-01-01

[Purpose] To investigate the sensitivity and specificity of a newly developed diagnostic tool, the Amer Dizziness Diagnostic Scale (ADDS), to evaluate and differentially diagnose vestibular disorder and to identify the strengths and weaknesses of the scale and its usefulness in clinical practice. [Subjects and Methods] Two hundred subjects of both genders (72 males, 128 females) aged between 18 to 60 (49.5±7.8) who had a history of vertigo and/or dizziness symptoms for this previous two weeks or less were recruited for the study. All subjects were referred by otolaryngologists, neurologists or family physicians in and around Jeddah, Kingdom of Saudi Arabia. On the first clinic visit, all the patients were evaluated once using the ADDS, following which they underwent routine testing of clinical signs and symptoms, audiometry, and a neurological examination, coupled with tests of Vestibulo-Ocular Reflex function, which often serves as the "gold standard" for determining the probability of a vestibular deficit. [Results] The results show that the ADDS strongly correlated with "true-positive" and "true-negative" responses for determining the probability of a vestibular disorder (r =0.95). A stepwise linear regression was conducted and the results indicate that the ADDS was a significant predictor of "true-positive" and "true-negative" responses in vestibular disorders (R(2) =0.90). Approximately 90% of the variability in the vestibular gold standard test was explained by its relationship to the ADDS. Moreover, the ADDS was found to have a sensitivity of 96% and a specificity of 96%. [Conclusion] This study showed that the Amer Dizziness Diagnostic Scale has high sensitivity and specificity and that it can be used as a method of differential diagnosis for patients with vestibular disorders.

Double immunohistochemical staining with MUC4/p53 is useful in the distinction of pancreatic adenocarcinoma from chronic pancreatitis: a tissue microarray-based study.

PubMed

Bhardwaj, Atul; Marsh, William L; Nash, Jason W; Barbacioru, Catalin C; Jones, Susie; Frankel, Wendy L

2007-04-01

Immunohistochemical stains have been used for the distinction of pancreatic adenocarcinoma from chronic pancreatitis. To determine if a double stain for MUC/p53 improved specificity and sensitivity for distinction of pancreatic adenocarcinoma from chronic pancreatitis by comparing maspin, mucin 4 (MUC4), p53, Smad4, and the double stain MUC4/p53. Seventy-four pancreatic adenocarcinomas and 19 chronic pancreatitis cases were retrieved from archival files. Tissue cores were arrayed to create a tissue microarray of 2-mm cores. Sections were stained with antibodies against maspin, MUC4, p53, and Smad4. Additionally, a 2-color, double stain for MUC4 and p53 was developed and evaluated. Five percent or greater staining in either of the cores was considered positive. Intensity (0, 1, 2) and extent (%) of tumor cells staining was also determined. The sensitivity for distinction of pancreatic adenocarcinoma from chronic pancreatitis with maspin, MUC4, p53, and Smad4 was 90%, 77%, 60%, and 63%, respectively; the specificity was 67%, 78%, 88%, and 88%, respectively. When MUC4 and p53 were combined in a double stain, and positive staining for either considered a positive result, the sensitivity increased to 96% but specificity was 73%. When immunoreactivity for both antibodies was necessary for a positive result, sensitivity fell to 39% but specificity was 100%. No correlation was found between intensity or extent of staining with any of the individual stains and tumor differentiation. The double immunohistochemical stain for MUC4/p53 can be a useful diagnostic tool in conjunction with the hematoxylin-eosin-stained section for pancreatic adenocarcinoma, particularly when limited tumor is available for multiple stains.

Diagnostic accuracy of ultrasound in upper and lower extremity long bone fractures of emergency department trauma patients.

PubMed

Frouzan, Arash; Masoumi, Kambiz; Delirroyfard, Ali; Mazdaie, Behnaz; Bagherzadegan, Elnaz

2017-08-01

Long bone fractures are common injuries caused by trauma. Some studies have demonstrated that ultrasound has a high sensitivity and specificity in the diagnosis of upper and lower extremity long bone fractures. The aim of this study was to determine the accuracy of ultrasound compared with plain radiography in diagnosis of upper and lower extremity long bone fractures in traumatic patients. This cross-sectional study assessed 100 patients admitted to the emergency department of Imam Khomeini Hospital, Ahvaz, Iran with trauma to the upper and lower extremities, from September 2014 through October 2015. In all patients, first ultrasound and then standard plain radiography for the upper and lower limb was performed. Data were analyzed by SPSS version 21 to determine the specificity and sensitivity. The mean age of patients with upper and lower limb trauma were 31.43±12.32 years and 29.63±5.89 years, respectively. Radius fracture was the most frequent compared to other fractures (27%). Sensitivity, specificity, positive predicted value, and negative predicted value of ultrasound compared with plain radiography in the diagnosis of upper extremity long bones were 95.3%, 87.7%, 87.2% and 96.2%, respectively, and the highest accuracy was observed in left arm fractures (100%). Tibia and fibula fractures were the most frequent types compared to other fractures (89.2%). Sensitivity, specificity, PPV and NPV of ultrasound compared with plain radiography in the diagnosis of upper extremity long bone fractures were 98.6%, 83%, 65.4% and 87.1%, respectively, and the highest accuracy was observed in men, lower ages and femoral fractures. The results of this study showed that ultrasound compared with plain radiography has a high accuracy in the diagnosis of upper and lower extremity long bone fractures.

Tumor invasiveness defined by IASLC/ATS/ERS classification of ground-glass nodules can be predicted by quantitative CT parameters.

PubMed

Zhou, Qian-Jun; Zheng, Zhi-Chun; Zhu, Yong-Qiao; Lu, Pei-Ji; Huang, Jia; Ye, Jian-Ding; Zhang, Jie; Lu, Shun; Luo, Qing-Quan

2017-05-01

To investigate the potential value of CT parameters to differentiate ground-glass nodules between noninvasive adenocarcinoma and invasive pulmonary adenocarcinoma (IPA) as defined by IASLC/ATS/ERS classification. We retrospectively reviewed 211 patients with pathologically proved stage 0-IA lung adenocarcinoma which appeared as subsolid nodules, from January 2012 to January 2013 including 137 pure ground glass nodules (pGGNs) and 74 part-solid nodules (PSNs). Pathological data was classified under the 2011 IASLC/ATS/ERS classification. Both quantitative and qualitative CT parameters were used to determine the tumor invasiveness between noninvasive adenocarcinomas and IPAs. There were 154 noninvasive adenocarcinomas and 57 IPAs. In pGGNs, CT size and area, one-dimensional mean CT value and bubble lucency were significantly different between noninvasive adenocarcinomas and IPAs on univariate analysis. Multivariate regression and ROC analysis revealed that CT size and one-dimensional mean CT value were predictive of noninvasive adenocarcinomas compared to IPAs. Optimal cutoff value was 13.60 mm (sensitivity, 75.0%; specificity, 99.6%), and -583.60 HU (sensitivity, 68.8%; specificity, 66.9%). In PSNs, there were significant differences in CT size and area, solid component area, solid proportion, one-dimensional mean and maximum CT value, three-dimensional (3D) mean CT value between noninvasive adenocarcinomas and IPAs on univariate analysis. Multivariate and ROC analysis showed that CT size and 3D mean CT value were significantly differentiators. Optimal cutoff value was 19.64 mm (sensitivity, 53.7%; specificity, 93.9%), -571.63 HU (sensitivity, 85.4%; specificity, 75.8%). For pGGNs, CT size and one-dimensional mean CT value are determinants for tumor invasiveness. For PSNs, tumor invasiveness can be predicted by CT size and 3D mean CT value.

Drama-induced affect and pain sensitivity.

PubMed

Zillmann, D; de Wied, M; King-Jablonski, C; Jenzowsky, S

1996-01-01

This study was conducted to examine the pain-ameliorating and pain-sensitizing effects of exposure to emotionally engaging drama. Specifically, the consequences for pain sensitivity of exposure to dramatic expositions differing in both excitatory and hedonic qualities were determined. Hedonically negative, neutral, and positive affective states were induced in male respondents by exposure to excerpts from cinematic drama. Pain sensitivity was assessed by the cuff-pressure procedure before and after exposure and by the cold pressor test after exposure only. When compared against the control condition, pain sensitivity diminished under conditions of hedonically positive affect. An inverse effect was suggested for hedonically negative conditions, but proved tentative and statistically unreliable. The findings are consistent with earlier demonstrations of mood effects on pain sensitivity. Unlike inconclusive earlier findings concerning the magnitude of directional effects, however, they suggest an asymmetry that emphasizes the pain-ameliorating effect of positive affects while lending little, if any, support to the proposal of a pain-sensitizing effect of negative affects. The investigation did not accomplish the intended creation of conditions necessary to test the proposal that heightened sympathetic activity diminishes pain sensitivity. The utility of a rigorous determination of this hypothesized relationship is emphasized, and procedures for a viable test of the proposal are suggested.

Residential care/assisted living staff may detect undiagnosed dementia using the minimum data set cognition scale.

PubMed

Zimmerman, Sheryl; Sloane, Philip D; Williams, Christianna S; Dobbs, Debra; Ellajosyula, Ratnavalli; Braaten, Alyssa; Rupnow, Marcia F T; Kaufer, Daniel I

2007-09-01

To estimate the sensitivity, specificity, and reliability of the Minimum Data Set Cognition Scale (MDS-COGS) in screening for undetected dementia when completed by direct care staff in residential care/assisted living (RC/AL) facilities and secondarily to determine the prevalence of dementia in the sample. A cross-sectional study in which staff were trained to complete the MDS-COGS. Research interviewers and a neuropsychologist obtained information on each participant. Two neurologists reviewed the data and examined the participant, rendering a probable diagnosis of dementia/non-dementia diagnosis. MDS-COGS results were compared with the neurologists' determination. Fourteen RC/AL facilities in North Carolina. Data were collected from 50 staff on 166 residents without a diagnosis of dementia. In addition to the MDS-COGS, measures included a comprehensive neuropsychological battery. Depression and other neuropsychiatric symptoms were also assessed. Neurologists determined that 38% of participants had probable dementia. An MDS-COGS cutpoint of 2 was highly specific (0.97) but not very sensitive (0.49) for dementia. Test-retest and interrater agreement for a negative screen were high (88% and 93%, respectively). The MDS-COGS is a simple, brief screen that RC/AL staff can complete. It will identify with high specificity a subset of residents with undetected dementia, allowing rapid identification of those likely to need dementia care. Caution needs to be exercised in light of its low sensitivity, because some with milder dementia will not be detected. Further work is needed to determine whether staff can and will use the MDS-COGS as a trigger for more-thorough assessment and to guide care and improve outcomes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nielsen, Yousef W., E-mail: yujwni01@heh.regionh.d; Eiberg, Jonas P.; Logager, Vibeke B.

The purpose of this investigation was to determine if addition of infragenicular steady-state (SS) magnetic resonance angiography (MRA) to first-pass imaging improves diagnostic performance compared with first-pass imaging alone in patients with peripheral arterial disease (PAD) undergoing whole-body (WB) MRA. Twenty consecutive patients with PAD referred to digital-subtraction angiography (DSA) underwent WB-MRA. Using a bolus-chase technique, first-pass WB-MRA was performed from the supra-aortic vessels to the ankles. The blood-pool contrast agent gadofosveset trisodium was used at a dose of 0.03 mmol/kg body weight. Ten minutes after injection of the contrast agent, high-resolution (0.7-mm isotropic voxels) SS-MRA of the infragenicular arteriesmore » was performed. Using DSA as the 'gold standard,' sensitivities and specificities for detecting significant arterial stenoses ({>=}50% luminal narrowing) with first-pass WB-MRA, SS-MRA, and combined first-pass and SS-MRA were calculated. Kappa statistics were used to determine intermodality agreement between MRA and DSA. Overall sensitivity and specificity for detecting significant arterial stenoses with first-pass WB-MRA was 0.70 (95% confidence interval 0.61 to 0.78) and 0.97 (0.94 to 0.99), respectively. In first-pass WB-MRA, the lowest sensitivity was in the infragenicular region, with a value of 0.42 (0.23 to 0.63). Combined analysis of first-pass WB-MRA and SS-MRA increased sensitivity to 0.81 (0.60 to 0.93) in the infragenicular region, with specificity of 0.94 (0.88 to 0.97). Sensitivity and specificity for detecting significant arterial stenoses with isolated infragenicular SS-MRA was 0.47 (0.27 to 0.69) and 0.86 (0.78 to 0.91), respectively. Intermodality agreement between MRA and DSA in the infragenicular region was moderate for first-pass WB-MRA ({kappa} = 0.49), fair for SS-MRA ({kappa} = 0.31), and good for combined first-pass/SS-MRA ({kappa} = 0.71). Addition of infragenicular SS-MRA to first-pass WB MRA improves diagnostic performance.« less

The Half RR Rule: A Poor Rule of Thumb and Not a Risk Assessment Tool for QT Interval Prolongation.

PubMed

Berling, Ingrid; Isbister, Geoffrey K

2015-10-01

Measuring the QT interval on an electrocardiogram (ECG) is integral to risk assessment of Torsade de Pointes (TdP). This study aimed to investigate the accuracy of the 1/2 RR rule as a risk assessment tool for drug-induced TdP, comparing it to the QT nomogram, Bazett's corrected QT (QTcB), and Fridericia's corrected QT (QTcF). The authors calculated sensitivity and specificity of the 1/2 RR rule using a published data set of 129 cases of drug-induced TdP and 316 controls (noncardiotoxic overdoses), compared to the QT nomogram, QTcB > 500 msec and QTcF > 500 msec. To further determine the value of the 1/2 RR rule, its observed positive, and negative agreement were calculated when compared to the QT nomogram for determining an abnormal QT in eight samples of different drugs in overdose. The sensitivity and specificity of the 1/2 RR rule were 88% (95% confidence interval [CI] = 80% to 93%) and 53% (95% CI = 47% to 58%), respectively, compared to the QT nomogram (sensitivity = 97%, 95% CI = 92% to 99%; specificity = 99%, 95% CI = 97% to 100%). It was also less sensitive than QTcB > 500 msec and had a lower specificity than QTcB > 500 msec and QTcF > 500 msec. In drug overdose patients, the 1/2 RR rule had poor observed agreement averaging 41%, which was mainly due to poor positive agreement, except for amisulpride where there was good agreement. The 1/2 RR rule was not as sensitive as the QT nomogram or QTcB > 500 msec for drug-induced TdP. It had poor positive agreement in almost all overdose patients, resulting in over half of patients receiving unnecessary cardiac monitoring and repeat ECGs. © 2015 by the Society for Academic Emergency Medicine.

Development and Validation of a Deep Learning Algorithm for Detection of Diabetic Retinopathy in Retinal Fundus Photographs.

PubMed

Gulshan, Varun; Peng, Lily; Coram, Marc; Stumpe, Martin C; Wu, Derek; Narayanaswamy, Arunachalam; Venugopalan, Subhashini; Widner, Kasumi; Madams, Tom; Cuadros, Jorge; Kim, Ramasamy; Raman, Rajiv; Nelson, Philip C; Mega, Jessica L; Webster, Dale R

2016-12-13

Deep learning is a family of computational methods that allow an algorithm to program itself by learning from a large set of examples that demonstrate the desired behavior, removing the need to specify rules explicitly. Application of these methods to medical imaging requires further assessment and validation. To apply deep learning to create an algorithm for automated detection of diabetic retinopathy and diabetic macular edema in retinal fundus photographs. A specific type of neural network optimized for image classification called a deep convolutional neural network was trained using a retrospective development data set of 128 175 retinal images, which were graded 3 to 7 times for diabetic retinopathy, diabetic macular edema, and image gradability by a panel of 54 US licensed ophthalmologists and ophthalmology senior residents between May and December 2015. The resultant algorithm was validated in January and February 2016 using 2 separate data sets, both graded by at least 7 US board-certified ophthalmologists with high intragrader consistency. Deep learning-trained algorithm. The sensitivity and specificity of the algorithm for detecting referable diabetic retinopathy (RDR), defined as moderate and worse diabetic retinopathy, referable diabetic macular edema, or both, were generated based on the reference standard of the majority decision of the ophthalmologist panel. The algorithm was evaluated at 2 operating points selected from the development set, one selected for high specificity and another for high sensitivity. The EyePACS-1 data set consisted of 9963 images from 4997 patients (mean age, 54.4 years; 62.2% women; prevalence of RDR, 683/8878 fully gradable images [7.8%]); the Messidor-2 data set had 1748 images from 874 patients (mean age, 57.6 years; 42.6% women; prevalence of RDR, 254/1745 fully gradable images [14.6%]). For detecting RDR, the algorithm had an area under the receiver operating curve of 0.991 (95% CI, 0.988-0.993) for EyePACS-1 and 0.990 (95% CI, 0.986-0.995) for Messidor-2. Using the first operating cut point with high specificity, for EyePACS-1, the sensitivity was 90.3% (95% CI, 87.5%-92.7%) and the specificity was 98.1% (95% CI, 97.8%-98.5%). For Messidor-2, the sensitivity was 87.0% (95% CI, 81.1%-91.0%) and the specificity was 98.5% (95% CI, 97.7%-99.1%). Using a second operating point with high sensitivity in the development set, for EyePACS-1 the sensitivity was 97.5% and specificity was 93.4% and for Messidor-2 the sensitivity was 96.1% and specificity was 93.9%. In this evaluation of retinal fundus photographs from adults with diabetes, an algorithm based on deep machine learning had high sensitivity and specificity for detecting referable diabetic retinopathy. Further research is necessary to determine the feasibility of applying this algorithm in the clinical setting and to determine whether use of the algorithm could lead to improved care and outcomes compared with current ophthalmologic assessment.

Head-shaking nystagmus predicts greater disability in unilateral peripheral vestibulopathy.

PubMed

Angeli, Simon I; Velandia, Sandra; Snapp, Hillary

2011-01-01

The objective of this study was to determine the association of the bedside test of head-shaking nystagmus (HSN) with patients' self-perceived dizziness handicap as well as this test's sensitivity and specificity in unilateral peripheral vestibular hypofunction. A retrospective case-control study was performed. The study was held at an academic, tertiary referral center. Fifty-three adult patients with unilateral peripheral hypofunction defined by the caloric test of the videonystagmography with documented bedside HSN and who had completed questionnaires of self-perceived dizziness handicap were included. The sensitivity and specificity of the bedside HSN in patients and 10 healthy controls in diagnosing unilateral vestibular hypofunction defined by videonystagmographic caloric testing and by abnormal gain and symmetry of the vestibular-ocular reflex by rotary chair testing were determined. Scores of the screening test of the Dizziness Handicap Index and Functional Level Scale questionnaires were taken. When using the caloric irrigation test as the reference standard for unilateral vestibular hypofunction, the sensitivity, specificity, and positive predictive value of the bedside HSN were 31%, 96%, and 97%, respectively. When comparing with results of rotational chair testing (vestibular-ocular reflex gain and symmetry), the sensitivity of the HSN test increases to 71%. Patients with positive bedside HSN had higher scores (greater self-perceived dizziness handicap) of the Dizziness Handicap Index (P = .049) and higher (worse) scores of the Functional Level Scale (P = .0377) than those with negative bedside HSN (Wilcoxon rank test). Greater perceived handicap was correlated with a positive bedside HSN in patients with unilateral peripheral vestibulopathy. The HSN has sufficient sensitivity to be used as screening test of uncompensated vestibulopathy in this series. However, a negative HSN alone does not rule out the diagnosis of peripheral vestibular dysfunction. Copyright © 2011 Elsevier Inc. All rights reserved.

Development of an ELISA for sensitive and specific detection of IgA autoantibodies against BP180 in pemphigoid diseases

PubMed Central

2011-01-01

Background Pemphigoids are rare diseases associated with IgG, IgE and IgA autoantibodies against collagen XVII/BP180. An entity of the pemphigoid group is the lamina lucida-type of linear IgA disease (IgA pemphigoid) characterized by IgA autoantibodies against BP180. While for the detection of IgG and IgE autoantibodies specific to collagen XVII several ELISA systems have been established, no quantitative immunoassay has been yet developed for IgA autoantibodies. Therefore, the aim of the present study was to develop an ELISA to detect IgA autoantibodies against collagen XVII in the sera of patients with pemphigoids. Methods We expressed a soluble recombinant form of the collagen XVII ectodomain in mammalian cells. Reactivity of IgA autoantibodies from patients with IgA pemphigoid was assessed by immunofluorescence microscopy and immunoblot analysis. ELISA test conditions were determined by chessboard titration experiments. The sensitivity, specificity and the cut-off were determined by receiver-operating characteristics analysis. Results The optimized assay was carried out using sera from patients with IgA pemphigoid (n = 30) and healthy donors (n = 105). By receiver operating characteristics (ROC) analysis, an area under the curve of 0.993 was calculated, indicating an excellent discriminatory capacity. Thus, a sensitivity and specificity of 83.3% and 100%, respectively, was determined for a cut-off point of 0.48. As additional control groups, sera from patients with bullous pemphigoid (n = 31) and dermatitis herpetiformis (n = 50), a disease associated with IgA autoantibodies against epidermal transglutaminase, were tested. In 26% of bullous pemphigoid patients, IgA autoantibodies recognized the ectodomain of collagen XVII. One of 50 (2%) of dermatitis herpetiformis patients sera slightly topped the cut-off value. Conclusions We developed the first ELISA for the specific and sensitive detection of serum IgA autoantibodies specific to collagen XVII in patients with pemphigoids. This immunoassay should prove a useful tool for clinical and translational research and should essentially improve the diagnosis and disease monitoring of patients with IgA pemphigoid. Moreover, our findings strongly suggest that IgA pemphigoid and IgG bullous pemphigoid represent two ends of the clinical spectrum of an immunological loss of tolerance against components of hemidesmosomes, which is mediated by both IgG and IgA autoantibodies. PMID:21619684

Assigning Cytomegalovirus (CMV) Status in Children Awaiting Organ Transplant: Viral Shedding, CMV-Specific T-cells and CD27-CD28-CD4+ T-cells.

PubMed

Burton, Catherine E; Sester, Martina; Robinson, Joan L; Eurich, Dean T; Preiksaitis, Jutta K; Urschel, Simon

2018-05-24

Passive antibodies, maternal or transfusion-acquired, make serologic determination of pre-transplant cytomegalovirus (CMV) status unreliable. We evaluated 3 assays un-affected by passive antibodies, in assignment of CMV infection status in children awaiting solid organ transplant and in controls: i) CMV Nucleic Acid Amplification Testing (NAAT), quantification of ii) CMV-specific CD4+T-cells, and iii) CD27-CD28-CD4+T-cells. Our results highlight that CMV NAAT, from urine and oropharynx, is useful in confirming positive CMV status. Detection of CMV-specific CD4+T-cells was sensitive and specific in children >18 months but was less sensitive in children <12 months. CD27-CD28- CD4+T-cells are not likely useful in CMV risk-stratification in children.

SELDI-TOF-MS proteomic profiling of serum, urine, and amniotic fluid in neural tube defects.

PubMed

Liu, Zhenjiang; Yuan, Zhengwei; Zhao, Qun

2014-01-01

Neural tube defects (NTDs) are common birth defects, whose specific biomarkers are needed. The purpose of this pilot study is to determine whether protein profiling in NTD-mothers differ from normal controls using SELDI-TOF-MS. ProteinChip Biomarker System was used to evaluate 82 maternal serum samples, 78 urine samples and 76 amniotic fluid samples. The validity of classification tree was then challenged with a blind test set including another 20 NTD-mothers and 18 controls in serum samples, and another 19 NTD-mothers and 17 controls in urine samples, and another 20 NTD-mothers and 17 controls in amniotic fluid samples. Eight proteins detected in serum samples were up-regulated and four proteins were down-regulated in the NTD group. Four proteins detected in urine samples were up-regulated and one protein was down-regulated in the NTD group. Six proteins detected in amniotic fluid samples were up-regulated and one protein was down-regulated in the NTD group. The classification tree for serum samples separated NTDs from healthy individuals, achieving a sensitivity of 91% and a specificity of 97% in the training set, and achieving a sensitivity of 90% and a specificity of 97% and a positive predictive value of 95% in the test set. The classification tree for urine samples separated NTDs from controls, achieving a sensitivity of 95% and a specificity of 94% in the training set, and achieving a sensitivity of 89% and a specificity of 82% and a positive predictive value of 85% in the test set. The classification tree for amniotic fluid samples separated NTDs from controls, achieving a sensitivity of 93% and a specificity of 89% in the training set, and achieving a sensitivity of 90% and a specificity of 88% and a positive predictive value of 90% in the test set. These suggest that SELDI-TOF-MS is an additional method for NTDs pregnancies detection.

Ultrasound as a screening test for genitourinary anomalies in children with UTI.

PubMed

Nelson, Caleb P; Johnson, Emilie K; Logvinenko, Tanya; Chow, Jeanne S

2014-03-01

The 2011 American Academy of Pediatrics guidelines state that renal and bladder ultrasound (RBUS) should be performed after initial febrile urinary tract infection (UTI) in a young child, with voiding cystourethrogram (VCUG) performed only if RBUS shows abnormalities. We sought to determine test characteristics and predictive values of RBUS for VCUG findings in this setting. We analyzed 3995 clinical encounters from January 1, 2006 to December 31, 2010 during which VCUG and RBUS were performed for history of UTI. Patients who had previous postnatal genitourinary imaging or history of prenatal hydronephrosis were excluded. Sensitivity, specificity, and predictive values of RBUS for VCUG abnormalities were determined. We identified 2259 patients age <60 months who had UTI as the indication for imaging. RBUS was reported as "normal" in 75%. On VCUG, any vesicoureteral reflux (VUR) was identified in 41.7%, VUR grade >II in 20.9%, and VUR grade >III in 2.8%. Sensitivity of RBUS for any abnormal findings on VCUG ranged from 5% (specificity: 97%) to 28% (specificity: 77%). Sensitivity for VUR grade >III ranged from 18% (specificity: 97%) to 55% (specificity: 77%). Among the 1203 children aged 2 to 24 months imaged after a first febrile UTI, positive predictive value of RBUS was 37% to 47% for VUR grade >II (13% to 24% for VUR grade >III); negative predictive value was 72% to 74% for VUR grade >II (95% to 96% for VUR grade >III). RBUS is a poor screening test for genitourinary abnormalities. RBUS and VCUG should be considered complementary as they provide important, but different, information.

Ultrasound as a Screening Test for Genitourinary Anomalies in Children With UTI

PubMed Central

Johnson, Emilie K.; Logvinenko, Tanya; Chow, Jeanne S.

2014-01-01

BACKGROUND: The 2011 American Academy of Pediatrics guidelines state that renal and bladder ultrasound (RBUS) should be performed after initial febrile urinary tract infection (UTI) in a young child, with voiding cystourethrogram (VCUG) performed only if RBUS shows abnormalities. We sought to determine test characteristics and predictive values of RBUS for VCUG findings in this setting. METHODS: We analyzed 3995 clinical encounters from January 1, 2006 to December 31, 2010 during which VCUG and RBUS were performed for history of UTI. Patients who had previous postnatal genitourinary imaging or history of prenatal hydronephrosis were excluded. Sensitivity, specificity, and predictive values of RBUS for VCUG abnormalities were determined. RESULTS: We identified 2259 patients age <60 months who had UTI as the indication for imaging. RBUS was reported as “normal” in 75%. On VCUG, any vesicoureteral reflux (VUR) was identified in 41.7%, VUR grade >II in 20.9%, and VUR grade >III in 2.8%. Sensitivity of RBUS for any abnormal findings on VCUG ranged from 5% (specificity: 97%) to 28% (specificity: 77%). Sensitivity for VUR grade >III ranged from 18% (specificity: 97%) to 55% (specificity: 77%). Among the 1203 children aged 2 to 24 months imaged after a first febrile UTI, positive predictive value of RBUS was 37% to 47% for VUR grade >II (13% to 24% for VUR grade >III); negative predictive value was 72% to 74% for VUR grade >II (95% to 96% for VUR grade >III). CONCLUSIONS: RBUS is a poor screening test for genitourinary abnormalities. RBUS and VCUG should be considered complementary as they provide important, but different, information. PMID:24515519

Target-protecting dumbbell molecular probe against exonucleases digestion for sensitive detection of ATP and streptavidin.

PubMed

Chen, Jinyang; Liu, Yucheng; Ji, Xinghu; He, Zhike

2016-09-15

In this work, a versatile dumbbell molecular (DM) probe was designed and employed in the sensitively homogeneous bioassay. In the presence of target molecule, the DM probe was protected from the digestion of exonucleases. Subsequently, the protected DM probe specifically bound to the intercalation dye and resulted in obvious fluorescence signal which was used to determine the target molecule in return. This design allows specific and versatile detection of diverse targets with easy operation and no sophisticated fluorescence labeling. Integrating the idea of target-protecting DM probe with adenosine triphosphate (ATP) involved ligation reaction, the DM probe with 5'-end phosphorylation was successfully constructed for ATP detection, and the limitation of detection was found to be 4.8 pM. Thanks to its excellent selectivity and sensitivity, this sensing strategy was used to detect ATP spiked in human serum as well as cellular ATP. Moreover, the proposed strategy was also applied in the visual detection of ATP in droplet-based microfluidic platform with satisfactory results. Similarly, combining the principle of target-protecting DM probe with streptavidin (SA)-biotin interaction, the DM probe with 3'-end biotinylation was developed for selective and sensitive SA determination, which demonstrated the robustness and versatility of this design. Copyright © 2016 Elsevier B.V. All rights reserved.

Can time-averaged flow boundary conditions be used to meet the clinical timeline for Fontan surgical planning?

PubMed

Wei, Zhenglun Alan; Trusty, Phillip M; Tree, Mike; Haggerty, Christopher M; Tang, Elaine; Fogel, Mark; Yoganathan, Ajit P

2017-01-04

Cardiovascular simulations have great potential as a clinical tool for planning and evaluating patient-specific treatment strategies for those suffering from congenital heart diseases, specifically Fontan patients. However, several bottlenecks have delayed wider deployment of the simulations for clinical use; the main obstacle is simulation cost. Currently, time-averaged clinical flow measurements are utilized as numerical boundary conditions (BCs) in order to reduce the computational power and time needed to offer surgical planning within a clinical time frame. Nevertheless, pulsatile blood flow is observed in vivo, and its significant impact on numerical simulations has been demonstrated. Therefore, it is imperative to carry out a comprehensive study analyzing the sensitivity of using time-averaged BCs. In this study, sensitivity is evaluated based on the discrepancies between hemodynamic metrics calculated using time-averaged and pulsatile BCs; smaller discrepancies indicate less sensitivity. The current study incorporates a comparison between 3D patient-specific CFD simulations using both the time-averaged and pulsatile BCs for 101 Fontan patients. The sensitivity analysis involves two clinically important hemodynamic metrics: hepatic flow distribution (HFD) and indexed power loss (iPL). Paired demographic group comparisons revealed that HFD sensitivity is significantly different between single and bilateral superior vena cava cohorts but no other demographic discrepancies were observed for HFD or iPL. Multivariate regression analyses show that the best predictors for sensitivity involve flow pulsatilities, time-averaged flow rates, and geometric characteristics of the Fontan connection. These predictors provide patient-specific guidelines to determine the effectiveness of analyzing patient-specific surgical options with time-averaged BCs within a clinical time frame. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detection of prostate-specific antigen with biomolecule-gated AlGaN/GaN high electron mobility transistors

NASA Astrophysics Data System (ADS)

Li, Jia-dong; Cheng, Jun-jie; Miao, Bin; Wei, Xiao-wei; Xie, Jie; Zhang, Jin-cheng; Zhang, Zhi-qiang; Wu, Dong-min

2014-07-01

In order to improve the sensitivity of AlGaN/GaN high electron mobility transistor (HEMT) biosensors, a simple biomolecule-gated AlGaN/GaN HEMT structure was designed and successfully fabricated for prostate specific antigen (PSA) detection. UV/ozone was used to oxidize the GaN surface and then a 3-aminopropyl trimethoxysilane (APTES) self-assembled monolayer was bound to the sensing region. This monolayer serves as a binding layer for attachment of the prostate specific antibody (anti-PSA). The biomolecule-gated AlGaN/GaN HEMT sensor shows a rapid and sensitive response when the target prostate-specific antigen in buffer solution was added to the antibody-immobilized sensing area. The current change showed a logarithm relationship against the PSA concentration from 0.1 pg/ml to 0.993 ng/ml. The sensitivity of 0.215% is determined for 0.1 pg/ml PSA solution. The above experimental result of the biomolecule-gated AlGaN/GaN HEMT biosensor suggested that this biosensor might be a useful tool for prostate cancer screening.

Development of an enzyme-linked immunosorbent assay for determination of the furaltadone etabolite, 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) in animal tissues

USDA-ARS?s Scientific Manuscript database

A rapid, sensitive, and specific competitive direct enzyme-linked immunosorbent assay (cdELISA) for determination of protein bound 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) residues is described to monitor the illegal use of furaltadone. Polyclonal and monoclonal antibodies were produced in...

Development of a genus-specific next generation sequencing approach for sensitive and quantitative determination of the Legionella microbiome in freshwater systems.

PubMed

Pereira, Rui P A; Peplies, Jörg; Brettar, Ingrid; Höfle, Manfred G

2017-03-31

Next Generation Sequencing (NGS) has revolutionized the analysis of natural and man-made microbial communities by using universal primers for bacteria in a PCR based approach targeting the 16S rRNA gene. In our study we narrowed primer specificity to a single, monophyletic genus because for many questions in microbiology only a specific part of the whole microbiome is of interest. We have chosen the genus Legionella, comprising more than 20 pathogenic species, due to its high relevance for water-based respiratory infections. A new NGS-based approach was designed by sequencing 16S rRNA gene amplicons specific for the genus Legionella using the Illumina MiSeq technology. This approach was validated and applied to a set of representative freshwater samples. Our results revealed that the generated libraries presented a low average raw error rate per base (<0.5%); and substantiated the use of high-fidelity enzymes, such as KAPA HiFi, for increased sequence accuracy and quality. The approach also showed high in situ specificity (>95%) and very good repeatability. Only in samples in which the gammabacterial clade SAR86 was present more than 1% non-Legionella sequences were observed. Next-generation sequencing read counts did not reveal considerable amplification/sequencing biases and showed a sensitive as well as precise quantification of L. pneumophila along a dilution range using a spiked-in, certified genome standard. The genome standard and a mock community consisting of six different Legionella species demonstrated that the developed NGS approach was quantitative and specific at the level of individual species, including L. pneumophila. The sensitivity of our genus-specific approach was at least one order of magnitude higher compared to the universal NGS approach. Comparison of quantification by real-time PCR showed consistency with the NGS data. Overall, our NGS approach can determine the quantitative abundances of Legionella species, i. e. the complete Legionella microbiome, without the need for species-specific primers. The developed NGS approach provides a new molecular surveillance tool to monitor all Legionella species in qualitative and quantitative terms if a spiked-in genome standard is used to calibrate the method. Overall, the genus-specific NGS approach opens up a new avenue to massive parallel diagnostics in a quantitative, specific and sensitive way.

Evaluation of clinical methods for diagnosing bacterial vaginosis.

PubMed

Gutman, Robert E; Peipert, Jeffrey F; Weitzen, Sherry; Blume, Jeffrey

2005-03-01

To determine whether the current clinical criteria for diagnosing bacterial vaginosis can be simplified by using 2 clinical criteria rather than the standard 3 of 4 criteria (Amsel's criteria). This was a prospective observational study of 269 women undergoing a vaginal examination in the Women's Primary Care Center, Division of Research, or Colposcopy Clinic at Women & Infants Hospital. All 4 clinical criteria for diagnosing bacterial vaginosis were collected, and Gram stain was used as the gold standard. Sensitivity and specificity were calculated for each individual criterion, combinations of criteria, and a colorimetric pH and amine card. Receiver operating characteristic curve was generated to estimate the preferred pH and percentage of clue cells for diagnosing bacterial vaginosis. The prevalence of bacterial vaginosis in our study population was 38.7%. Vaginal pH was the most sensitive of all the criteria, at 89%, and a positive amine odor was the individual criteria with the highest specificity, at 93%. Similar specificity was seen with combinations of 2 criteria and Amsel's criteria. Receiver operating characteristic curve analysis yielded a preferred pH and percentage of clue cells of 5.0 and 20%, respectively. However, a pH of 4.5 or greater improves sensitivity with minimal loss of specificity. The clinical criteria for diagnosing bacterial vaginosis can be simplified to 2 clinical criteria without loss of sensitivity and specificity.

Evaluation of acute knee pain in primary care.

PubMed

Jackson, Jeffrey L; O'Malley, Patrick G; Kroenke, Kurt

2003-10-07

The evaluation of acute knee pain often includes radiography of the knee. To synthesize the literature to determine the role of radiologic procedures in evaluating common causes of acute knee pain: fractures, meniscal or ligamentous injuries, osteoarthritis, and pseudogout. MEDLINE search from 1966 to October 2002. We included all published, peer-reviewed studies of decision rules for fractures. We included studies that used arthroscopy as the gold standard for measuring the accuracy of the physical examination and magnetic resonance imaging (MRI) for meniscal and ligamentous knee damage. We included all studies on the use of radiographs in pseudogout. We extracted all data in duplicate and abstracted physical examination and MRI results into 2 x 2 tables. Among the 5 decision rules for deciding when to use plain films in knee fractures, the Ottawa knee rules (injury due to trauma and age >55 years, tenderness at the head of the fibula or the patella, inability to bear weight for 4 steps, or inability to flex the knee to 90 degrees) have the strongest supporting evidence. When the history suggests a potential meniscal or ligamentous injury, the physical examination is moderately sensitive (meniscus, 87%; anterior cruciate ligament, 74%; and posterior cruciate ligament, 81%) and specific (meniscus, 92%; anterior cruciate ligament, 95%; and posterior cruciate ligament, 95%). The Lachman test is more sensitive and specific for ligamentous tears than is the drawer sign. For meniscal tears, joint line tenderness is sensitive (75%) but not specific (27%), while the McMurray test is specific (97%) but not sensitive (52%). Compared with the physical examination, MRI is more sensitive for ligamentous and meniscal damage but less specific. When the differential diagnosis for acute knee pain includes an exacerbation of osteoarthritis, clinical features (age >50 years, morning stiffness <30 minutes, crepitus, or bony enlargement) are 89% sensitive and 88% specific for underlying chronic arthritis. Adding plain films improves sensitivity slightly but not specificity. Plain films for pseudogout are not sensitive or specific, according to limited-quality studies. We recommend the Ottawa knee rules to decide when to obtain plain films for suspected knee fracture. A careful physical examination should be sufficient to decide whether to refer patients with potential meniscal and ligament injuries, and we prefer clinical criteria rather than plain films for evaluating osteoarthritis. We do not recommend using plain films to diagnose pseudogout.

Sensitivity, accuracy, and precision issues in opto-electronic holography based on fiber optics and high-spatial- and high-digitial-resolution cameras

NASA Astrophysics Data System (ADS)

Furlong, Cosme; Yokum, Jeffrey S.; Pryputniewicz, Ryszard J.

2002-06-01

Sensitivity, accuracy, and precision characteristics in quantitative optical metrology techniques, and specifically in optoelectronic holography based on fiber optics and high-spatial and high-digital resolution cameras, are discussed in this paper. It is shown that sensitivity, accuracy, and precision dependent on both, the effective determination of optical phase and the effective characterization of the illumination-observation conditions. Sensitivity, accuracy, and precision are investigated with the aid of National Institute of Standards and Technology (NIST) traceable gages, demonstrating the applicability of quantitative optical metrology techniques to satisfy constantly increasing needs for the study and development of emerging technologies.

High resolution microendoscopy for classification of colorectal polyps.

PubMed

Chang, S S; Shukla, R; Polydorides, A D; Vila, P M; Lee, M; Han, H; Kedia, P; Lewis, J; Gonzalez, S; Kim, M K; Harpaz, N; Godbold, J; Richards-Kortum, R; Anandasabapathy, S

2013-07-01

It can be difficult to distinguish adenomas from benign polyps during routine colonoscopy. High resolution microendoscopy (HRME) is a novel method for imaging colorectal mucosa with subcellular detail. HRME criteria for the classification of colorectal neoplasia have not been previously described. Study goals were to develop criteria to characterize HRME images of colorectal mucosa (normal, hyperplastic polyps, adenomas, cancer) and to determine the accuracy and interobserver variability for the discrimination of neoplastic from non-neoplastic polyps when these criteria were applied by novice and expert microendoscopists. Two expert pathologists created consensus HRME image criteria using images from 68 patients with polyps who had undergone colonoscopy plus HRME. Using these criteria, HRME expert and novice microendoscopists were shown a set of training images and then tested to determine accuracy and interobserver variability. Expert microendoscopists identified neoplasia with sensitivity, specificity, and accuracy of 67 % (95 % confidence interval [CI] 58 % - 75 %), 97 % (94 % - 100 %), and 87 %, respectively. Nonexperts achieved sensitivity, specificity, and accuracy of 73 % (66 % - 80 %), 91 % (80 % - 100 %), and 85 %, respectively. Overall, neoplasia were identified with sensitivity 70 % (65 % - 76 %), specificity 94 % (87 % - 100 %), and accuracy 85 %. Kappa values were: experts 0.86; nonexperts 0.72; and overall 0.78. Using the new criteria, observers achieved high specificity and substantial interobserver agreement for distinguishing benign polyps from neoplasia. Increased expertise in HRME imaging improves accuracy. This low-cost microendoscopic platform may be an alternative to confocal microendoscopy in lower-resource or community-based settings.

Use of electronic data and existing screening tools to identify clinically significant obstructive sleep apnea.

PubMed

Severson, Carl A; Pendharkar, Sachin R; Ronksley, Paul E; Tsai, Willis H

2015-01-01

To assess the ability of electronic health data and existing screening tools to identify clinically significant obstructive sleep apnea (OSA), as defined by symptomatic or severe OSA. The present retrospective cohort study of 1041 patients referred for sleep diagnostic testing was undertaken at a tertiary sleep centre in Calgary, Alberta. A diagnosis of clinically significant OSA or an alternative sleep diagnosis was assigned to each patient through blinded independent chart review by two sleep physicians. Predictive variables were identified from online questionnaire data, and diagnostic algorithms were developed. The performance of electronically derived algorithms for identifying patients with clinically significant OSA was determined. Diagnostic performance of these algorithms was compared with versions of the STOP-Bang questionnaire and adjusted neck circumference score (ANC) derived from electronic data. Electronic questionnaire data were highly sensitive (>95%) at identifying clinically significant OSA, but not specific. Sleep diagnostic testing-determined respiratory disturbance index was very specific (specificity ≥95%) for clinically relevant disease, but not sensitive (<35%). Derived algorithms had similar accuracy to the STOP-Bang or ANC, but required fewer questions and calculations. These data suggest that a two-step process using a small number of clinical variables (maximizing sensitivity) and objective diagnostic testing (maximizing specificity) is required to identify clinically significant OSA. When used in an online setting, simple algorithms can identify clinically relevant OSA with similar performance to existing decision rules such as the STOP-Bang or ANC.

SU-F-303-05: DCE-MRI Before and During Treatment for Prediction of Concurrent Chemotherapy and Radiation Therapy Response in Head and Neck Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Y; Diwanji, T; Zhang, B

2015-06-15

Purpose: To determine the ability of pharmacokinetic parameters derived from dynamic contrast-enhanced MRI (DCE- MRI) acquired before and during concurrent chemotherapy and radiation therapy to predict clinical response in patients with head and neck cancer. Methods: Eleven patients underwent a DCE-MRI scan at three time points: 1–2 weeks before treatment, 4–5 weeks after treatment initiation, and 3–4 months after treatment completion. Post-processing of MRI data included correction to reduce motion artifacts. The arterial input function was obtained by measuring the dynamic tracer concentration in the jugular veins. The volume transfer constant (Ktrans), extracellular extravascular volume fraction (ve), rate constant (Kep;more » Kep = Ktrans/ve), and plasma volume fraction (vp) were computed for primary tumors and cervical nodal masses. Patients were categorized into two groups based on response to therapy at 3–4 months: responders (no evidence of disease) and partial responders (regression of disease). Responses of the primary tumor and nodes were evaluated separately. A linear classifier and receiver operating characteristic curve analyses were used to determine the best model for discrimination of responders from partial responders. Results: When the above pharmacokinetic parameters of the primary tumor measured before and during treatment were incorporated into the linear classifier, a discriminative accuracy of 88.9%, with sensitivity =100% and specificity = 66.7%, was observed between responders (n=6) and partial responders (n=3) for the primary tumor with the corresponding accuracy = 44.4%, sensitivity = 66.7%, and specificity of 0% for nodal masses. When only pre-treatment parameters were used, the accuracy decreased to 66.7%, with sensitivity = 66.7% and specificity = 66.7% for the primary tumor and decreased to 33.3%, sensitivity of 50%, and specificity of 0% for nodal masses. Conclusion: Higher accuracy, sensitivity, and specificity were obtained using DCE-MRI-derived pharmacokinetic parameters acquired before and during treatment as compared with those derived from the pre-treatment time-point, exclusively.« less

The RIPASA score is sensitive and specific for the diagnosis of acute appendicitis in a western population.

PubMed

Malik, Muhammad Usman; Connelly, Tara M; Awan, Faisal; Pretorius, Frederik; Fiuza-Castineira, Constantino; El Faedy, Osama; Balfe, Paul

2017-04-01

The definitive diagnosis of acute appendicitis (AA) requires histopathological examination. Various clinical diagnostic scoring systems attempt to reduce negative appendectomy rates. The most commonly used in Western Europe and the USA is the Alvarado score. The Raja Isteri Pengiran Anak Saleha appendicitis (RIPASA) score achieves better sensitivity and specificity in Asian and Middle Eastern populations. We aimed to determine the diagnostic accuracy of the RIPASA score in Irish patients with AA. All patients who presented to our institution with right iliac fossa pain and clinically suspected AA between January 1 and December 31, 2015, were indentified from our hospital inpatient enquiry database and retrospectively studied. Operating theatre records and histology reports confirmed those who underwent a non-elective operative procedure and the presence or absence of AA. SPSS version 22 was used for statistical analysis. Standard deviation is provided where appropriate. Two hundred eight patients were included in the study (106/51% male, mean age 22.7 ± 9.2 years). One hundred thirty-five (64.9%) had histologically confirmed AA (mean symptom duration = 36.19 ± 15.90 h). At a score ≥7.5, the previously determined score most likely associated with AA in Eastern populations, the RIPASA scoring system demonstrated a sensitivity of 85.39%, specificity of 69.86%, positive predictive value of 84.06%, negative predictive value of 72.86% and diagnostic accuracy of 80% in our cohort. The RIPASA score is a useful tool to aid in the diagnosis of acute appendicitis in the Irish population. A score of ≥7.5 provides sensitivity and specificity exceeding that previously documented for the Alvarado score in Western populations. WHAT DOES THIS PAPER ADD TO THE LITERATURE?: This is the first study evaluating the utility of the RIPASA score in predicting acute appendicitis in a Western population. At a value of 7.5, a cut-off score suggestive of appendicitis in the Eastern population, RIPASA demonstrated a high-sensitivity, specificity, positive predictive value and diagnostic accuracy in our cohort and was more accurate than the commonly used Alvarado score.

Sensitive method for the quantitative determination of bromocriptine in human plasma by liquid chromatography-tandem mass spectrometry.

PubMed

Salvador, Arnaud; Dubreuil, Didier; Denouel, Jannick; Millerioux, L

2005-06-25

A sensitive LC-MS-MS assay for the quantitative determination of bromocriptine has been developed and validated and is described in this work. The assay involved the extraction of the analyte from 1 ml of human plasma using a solid phase extraction on Oasis MCX cartridges. Chromatography was performed on a Symmetry C18 (2.1 mm x 100 mm, 3.5 microm) column using a mobile phase consisting of 25:75:01 acetonitrile-water-formic acid with a flow rate of 250 microl/min. The linearity was within the concentration range of 2-500 pg/ml. The lower limit of quantification was 2 pg/ml. This method has been demonstrated to be an improvement over existing methods due to its greater sensitivity and specificity.

CSF ADA Determination in Early Diagnosis of Tuberculous Meningitis in HIV-Infected Patients.

PubMed

Ghosh, Gopal Chandra; Sharma, Brijesh; Gupta, B B

2016-01-01

Tuberculous and Cryptococcal meningitis are common in HIV patients. A highly specific and sensitive rapid test for diagnosis of Tuberculous meningitis especially in setting of HIV is not available in developing countries where the burden of disease is high. We measured ADA (adenosine deaminase) levels using spectrophotometric method in the CSF of HIV patients with meningitis to differentiate Tuberculous meningitis from meningitis due to other causes. Kruskal-Wallis test was used to compare ADA values between tuberculous meningitis (TBM) and nontuberculous (non-TB) meningitis patients and a receiver-operating characteristic (ROC) analysis curve was drawn from these values. Levels of ADA in the CSF of patients with TBM were significantly higher than those in patients with meningitis due to other causes. CSF ADA level determination with a cut-off value of 6 IU/L was found to be highly specific and fairly sensitive test for the diagnosis of TBM in HIV positive patients.

Comparison of a Novel Multiple Marker Assay Versus the Risk of Malignancy Index for the Prediction of Epithelial Ovarian Cancer in Patients with a Pelvic Mass

PubMed Central

MOORE, Richard G.; JABRE-RAUGHLEY, Moune; BROWN, Amy K.; ROBISON, Katina M.; MILLER, M. Craig; ALLARD, W. Jeffery; KURMAN, Robert J.; BAST, Robert C.; SKATES, Steven J.

2012-01-01

Objectives To compare the Risk of Malignancy Index (RMI) to the Risk of Ovarian Malignancy Algorithm (ROMA) to predict EOC in women with a pelvic mass. Study Design 457 women with imaging results from ultrasound, CT and MRI, and serum HE4 and CA 125 determined prior to surgery for pelvic mass were evaluable. RMI values were determined using CA 125, imaging score and menopausal status. ROMA values were determined using HE4, CA 125, and menopausal status. Results At a set specificity of 75%, ROMA had a sensitivity of 94.3% and RMI had a sensitivity of 84.6% for distinguishing benign from EOC (p=0.0029). In patients with stage I and II disease, ROMA achieved a sensitivity of 85.3% compared with 64.7% for RMI (p<0.0001). Conclusions The dual marker algorithm utilizing HE4 and CA125 to calculate a ROMA value achieves a significantly higher sensitivity for identifying women with EOC than does RMI. PMID:20471625

Use of basal serum or plasma cortisol concentrations to rule out a diagnosis of hypoadrenocorticism in dogs: 123 cases (2000-2005).

PubMed

Lennon, Elizabeth M; Boyle, Tonya E; Hutchins, Rae Grace; Friedenthal, Arit; Correa, Maria T; Bissett, Sally A; Moses, Lorra S; Papich, Mark G; Birkenheuer, Adam J

2007-08-01

To determine whether basal serum or plasma cortisol concentration can be used as a screening test to rule out hypoadrenocorticism in dogs. Retrospective case-control study. 110 dogs with nonadrenal gland illnesses and 13 dogs with hypoadrenocorticism. Sensitivity and specificity of basal serum or plasma cortisol concentrations of either 2 microg/dL that are not receiving corticosteroids, mitotane, or ketoconazole are highly unlikely to have hypoadrenocorticism. However, if the basal cortisol concentration is

The sensitivity and specificity of touch preparation for rapid diagnosis of invasive fungal sinusitis: A pilot study.

PubMed

Schuman, Theodore A; Nguyen, Josephine H; Yelverton, Joshua C; Almenara, Jorge A; Powers, Celeste N

2018-01-01

Invasive fungal sinusitis is a morbid pathology that typically affects immunocompromised patients and may quickly progress to fulminant disease. The purpose of this study was to measure the sensitivity and specificity of touch preparation of nasal debridement specimens as a rapid diagnostic tool for invasive fungal sinusitis. A retrospective chart review was performed of 22 patients undergoing nasal debridement due to suspicion for invasive fungal sinusitis over a 10-year period. Thirteen patients had touch preparation of nasal specimens followed by routine histologic processing; 2 of these patients underwent two and 1 patient had three separate debridements, for a total of 17 touch preparations performed. The sensitivity and specificity of touch preparation were calculated by correlating the initial results with the presence of fungal invasion on final pathologic analysis. The sensitivity of touch preparation was 56% (95% confidence interval [CI]: 0.23 to 0.85), specificity was 100% (95% CI: 0.60 to 1.00), positive predictive value was 100% (95% CI: 0.46 to 1.00), and negative predictive value was 67% (95% CI: 0.35 to 0.89). This procedure may be a useful adjunct in situations requiring rapid diagnosis of invasive fungal sinusitis but should not be used as the sole criterion for determining the need for surgical intervention.

Review-of-systems questionnaire as a predictive tool for psychogenic nonepileptic seizures.

PubMed

Robles, Liliana; Chiang, Sharon; Haneef, Zulfi

2015-04-01

Patients with refractory epilepsy undergo video-electroencephalography for seizure characterization, among whom approximately 10-30% will be discharged with the diagnosis of psychogenic nonepileptic seizures (PNESs). Clinical PNES predictors have been described but in general are not sensitive or specific. We evaluated whether multiple complaints in a routine review-of-system (ROS) questionnaire could serve as a sensitive and specific marker of PNESs. We performed a retrospective analysis of a standardized ROS questionnaire completed by patients with definite PNESs and epileptic seizures (ESs) diagnosed in our adult epilepsy monitoring unit. A multivariate analysis of covariance (MANCOVA) was used to determine whether groups with PNES and ES differed with respect to the percentage of complaints in the ROS questionnaire. Tenfold cross-validation was used to evaluate the predictive error of a logistic regression classifier for PNES status based on the percentage of positive complaints in the ROS questionnaire. A total of 44 patients were included for analysis. Patients with PNESs had a significantly higher number of complaints in the ROS questionnaire compared to patients with epilepsy. A threshold of 17% positive complaints achieved a 78% specificity and 85% sensitivity for discriminating between PNESs and ESs. We conclude that the routine ROS questionnaire may be a sensitive and specific predictive tool for discriminating between PNESs and ESs. Published by Elsevier Inc.

Comparison of Sofia Legionella FIA and BinaxNOW® Legionella urinary antigen card in two national reference centers.

PubMed

Beraud, L; Gervasoni, K; Freydiere, A M; Descours, G; Ranc, A G; Vandenesch, F; Lina, G; Gaia, V; Jarraud, S

2015-09-01

The Sofia Legionella Fluorescence Immunoassay (FIA; Quidel) is a recently introduced rapid immunochromatographic diagnostic test for Legionnaires' disease using immunofluorescence technology designed to enhance its sensitivity. The aim of this study was to evaluate its performance for the detection of urinary antigens for Legionella pneumophila serogroup 1 in two National Reference Centers for Legionella. The sensitivity and specificity of the Sofia Legionella FIA test were determined in concentrated and nonconcentrated urine samples, before and after boiling, in comparison with the BinaxNOW® Legionella Urinary Antigen Card (UAC; Alere). Compared with BinaxNOW® Legionella UAC, the sensitivity of the Sofia Legionella test was slightly higher in nonconcentrated urine samples and was identical in concentrated urine samples. The specificity of the Sofia Legionella FIA test was highly reduced by the concentration of urine samples. In nonconcentrated samples, a lack of specificity was observed in 2.3 % of samples, all of them resolved by heat treatment. The Sofia Legionella FIA is a sensitive test for detecting Legionella urinary antigens with no previous urine concentration. However, all positive samples have to be re-tested after boiling to reach a high specificity. The reading is automatized on the Sofia analyzer, which can be connected to laboratory information systems, facilitating accurate and rapid reporting of results.

Use of shear wave elastography to differentiate benign and malignant breast lesions.

PubMed

Çebi Olgun, Deniz; Korkmazer, Bora; Kılıç, Fahrettin; Dikici, Atilla Süleyman; Velidedeoğlu, Mehmet; Aydoğan, Fatih; Kantarcı, Fatih; Yılmaz, Mehmet Halit

2014-01-01

We aimed to determine the correlations between the elasticity values of solid breast masses and histopathological findings to define cutoff elasticity values differentiating malignant from benign lesions. A total of 115 solid breast lesions of 109 consecutive patients were evaluated prospectively using shear wave elastography (SWE). Two orthogonal elastographic images of each lesion were obtained. Minimum, mean, and maximum elasticity values were calculated in regions of interest placed over the stiffest areas on the two images; we also calculated mass/fat elasticity ratios. Correlation of elastographic measurements with histopathological results were studied. Eighty-three benign and thirty-two malignant lesions were histopathologically diagnosed. The minimum, mean, and maximum elasticity values, and the mass/fat elasticity ratios of malignant lesions, were significantly higher than those of benign lesions. The cutoff value was 45.7 kPa for mean elasticity (sensitivity, 96%; specificity, 95%), 54.3 kPa for maximum elasticity (sensitivity, 95%; specificity, 94%), 37.1 kPa for minimum elasticity (sensitivity, 96%; specificity, 95%), and 4.6 for the mass/fat elasticity ratio (sensitivity, 97%; specificity, 95%). SWE yields additional valuable quantitative data to ultrasonographic examination on solid breast lesions. SWE may serve as a complementary tool for diagnosis of breast lesions. Long-term clinical studies are required to accurately select lesions requiring biopsy.

Computer-aided interpretation approach for optical tomographic images

NASA Astrophysics Data System (ADS)

Klose, Christian D.; Klose, Alexander D.; Netz, Uwe J.; Scheel, Alexander K.; Beuthan, Jürgen; Hielscher, Andreas H.

2010-11-01

A computer-aided interpretation approach is proposed to detect rheumatic arthritis (RA) in human finger joints using optical tomographic images. The image interpretation method employs a classification algorithm that makes use of a so-called self-organizing mapping scheme to classify fingers as either affected or unaffected by RA. Unlike in previous studies, this allows for combining multiple image features, such as minimum and maximum values of the absorption coefficient for identifying affected and not affected joints. Classification performances obtained by the proposed method were evaluated in terms of sensitivity, specificity, Youden index, and mutual information. Different methods (i.e., clinical diagnostics, ultrasound imaging, magnet resonance imaging, and inspection of optical tomographic images), were used to produce ground truth benchmarks to determine the performance of image interpretations. Using data from 100 finger joints, findings suggest that some parameter combinations lead to higher sensitivities, while others to higher specificities when compared to single parameter classifications employed in previous studies. Maximum performances are reached when combining the minimum/maximum ratio of the absorption coefficient and image variance. In this case, sensitivities and specificities over 0.9 can be achieved. These values are much higher than values obtained when only single parameter classifications were used, where sensitivities and specificities remained well below 0.8.

Evaluation of immunity to varicella zoster virus with a novel double antigen sandwich enzyme-linked immunosorbent assay.

PubMed

Liu, Jian; Chen, Chunye; Zhu, Rui; Ye, Xiangzhong; Jia, Jizong; Yang, Lianwei; Wang, Yongmei; Wang, Wei; Ye, Jianghui; Li, Yimin; Zhu, Hua; Zhao, Qinjian; Zhang, Jun; Cheng, Tong; Xia, Ningshao

2016-11-01

Varicella is a highly contagious disease caused by primary infection of Varicella zoster virus (VZV). Varicella can be severe or even lethal in susceptible adults, immunocompromised patients and neonates. Determination of the status of immunity to VZV is recommended for these high-risk populations. Furthermore, measurement of population immunity to VZV can help in developing proper varicella vaccination programmes. VZV glycoprotein E (gE) is an antigen that has been demonstrated to be a highly accurate indicator of VZV-specific immunity. In this study, recombinant gE (rgE) was used to establish a double antigen sandwich enzyme-linked immunosorbent assay (ELISA). The established sandwich ELISA showed high specificity and sensitivity in the detection of human sera, and it could detect VZV-specific antibodies at a concentration of 11.25 m IU/mL with a detection linearity interval of 11.25 to 360 m IU/mL (R 2  = 0.9985). The double gE antigen sandwich ELISA showed a sensitivity of 95.08 % and specificity of 100 % compared to the fluorescent-antibody-to-membrane-antigen (FAMA) test, and it showed a sensitivity of 100 % and a specificity of 94.74 % compared to a commercial neutralizing antibody detection kit. Thus, the established double antigen sandwich ELISA can be used as a sensitive and specific quantitative method to evaluate immunity to VZV.

Utility of Gram staining for diagnosis of Malassezia folliculitis.

PubMed

Tu, Wei-Ting; Chin, Szu-Ying; Chou, Chia-Lun; Hsu, Che-Yuan; Chen, Yu-Tsung; Liu, Donald; Lee, Woan-Ruoh; Shih, Yi-Hsien

2018-02-01

Malassezia folliculitis (MalF) mimics acne vulgaris and bacterial folliculitis in clinical presentations. The role of Gram staining in rapid diagnosis of MalF has not been well studied. In our study, 32 patients were included to investigate the utility of Gram staining for MalF diagnosis. The final diagnoses of MalF were determined according to clinical presentation, pathological result and treatment response to antifungal agents. Our results show that the sensitivity and specificity of Gram staining are 84.6% and 100%, respectively. In conclusion, Gram staining is a rapid, non-invasive, sensitive and specific method for MalF diagnosis. © 2017 Japanese Dermatological Association.

A Comparative Analysis of Coprologic Diagnostic Methods for Detection of Toxoplama gondii in Cats

PubMed Central

Salant, Harold; Spira, Dan T.; Hamburger, Joseph

2010-01-01

The relative role of transmission of Toxoplasma gondii infection from cats to humans appears to have recently increased in certain areas. Large-scale screening of oocyst shedding in cats cannot rely on microscopy because oocyst identification lacks sensitivity and specificity, or on bioassays, which require test animals and weeks before examination. We compared a sensitive and species-specific coprologic–polymerase chain reaction (copro-PCR) for detection of T. gondii infected cats with microscopy and a bioassay. In experimentally infected cats followed over time, microscopy was positive occasionally, and positive copro-PCR and bioassay results were obtained continuously from days 2 to 24 post-infection. The copro-PCR is at least as sensitive and specific as the bioassay and is capable of detecting infective oocysts during cat infection. Therefore, this procedure can be used as the new gold standard for determining potential cat infectivity. Its technologic advantages over the bioassay make it superior for large-scale screening of cats. PMID:20439968

Chronic pesticide poisoning from persistent low-dose exposures in Ecuadorean floriculture workers: toward validating a low-cost test battery.

PubMed

Breilh, Jaime; Pagliccia, Nino; Yassi, Annalee

2012-01-01

Chronic pesticide poisoning is difficult to detect. We sought to develop a low-cost test battery for settings such as Ecuador's floriculture industry. First we had to develop a case definition; as with all occupational diseases a case had to have both sufficient effective dose and associated health effects. For the former, using canonical discriminant analysis, we found that adding measures of protection and overall environmental stressors to occupational category and duration of exposure was useful. For the latter, factor analysis suggested three distinct manifestations of pesticide poisoning. We then determined sensitivity and specificity of various combinations of symptoms and simple neurotoxicity tests from the Pentox questionnaire, and found that doing so increased sensitivity and specificity compared to use of acethylcholinesterase alone--the current screening standard. While sensitivity and specificity varied with different case definitions, our results support the development of a low-cost test battery for screening in such settings.

Artificial neural network techniques to improve the ability of optical coherence tomography to detect optic neuritis.

PubMed

Garcia-Martin, Elena; Herrero, Raquel; Bambo, Maria P; Ara, Jose R; Martin, Jesus; Polo, Vicente; Larrosa, Jose M; Garcia-Feijoo, Julian; Pablo, Luis E

2015-01-01

To analyze the ability of Spectralis optical coherence tomography (OCT) to detect multiple sclerosis (MS) and to distinguish MS eyes with antecedent optic neuritis (ON). To analyze the capability of artificial neural network (ANN) techniques to improve the diagnostic precision. MS patients and controls were enrolled (n = 217). OCT was used to determine the 768 retinal nerve fiber layer thicknesses. Sensitivity and specificity were evaluated to test the ability of OCT to discriminate between MS and healthy eyes, and between MS with and without antecedent ON using ANN. Using ANN technique multilayer perceptrons, OCT could detect MS with a sensitivity of 89.3%, a specificity of 87.6%, and a diagnostic precision of 88.5%. Compared with the OCT-provided parameters, the ANN had a better sensitivity-specificity balance. ANN technique improves the capability of Spectralis OCT to detect MS disease and to distinguish MS eyes with or without antecedent ON.

Comparison of enzyme immunoassays for antibodies to Haemophilus ducreyi in a community outbreak of chancroid in the United States.

PubMed

Chen, C Y; Mertz, K J; Spinola, S M; Morse, S A

1997-06-01

The performance of two EIAs (adsorption EIA and lipooligosaccharide [LOS] EIA) that detect antibodies to Haemophilus ducreyi was evaluated with serum specimens obtained from 163 patients (96 with genital ulcer disease [GUD]). Paired serum specimens (initial and follow-up) were obtained from 52 of the GUD patients. By use of initial serum specimens from 82 GUD patients whose etiologic agents for their ulcers had been identified, the adsorption EIA had a sensitivity and specificity for chancroid of 53% and 71%, while the LOS EIA had a sensitivity and specificity of 48% and 89%, respectively. Sensitivity and specificity of the adsorption EIA increased to 78% and 84%, respectively, when the results of follow-up serum specimens were used to calculate optimal performance. The proportion of patients testing positive for H. ducreyi who had anti-H. ducreyi IgG antibodies, as determined by adsorption EIA, increased with the duration of infection, thus limiting the role of EIAs in the diagnosis of chancroid.

Liver Rapid Reference Set Application (#1): David Lubman - Univ of Michigan (2009) — EDRN Public Portal

Cancer.gov

We are requesting the reference set, which includes 50 HCC cases and 50 cirrhotic controls. In our preliminary study, AFP had a AUROC of 0.66 while the AUROC for the 5 glycoproteins was 0.81. The sensitivity and specificity for the 5 glycoproteins was 79% and 72% at the point that maximizes sensitivity+specificity in the ROC curve, and it was 79% and 35%, respectively, for AFP at the same point in the ROC curve. The reference set will allow us to determine the best performance of the 5 glycoproteins by themselves or whether their combination has a better sensitivity and/or specificity and AUROC. While a direct comparison with AFP will be made, the reference set will not allow a robust comparison due to the low sample size. If the glycoproteins are complementary or have better performance than AFP, then the next step would be to test them in the entire phase 2 hepatocellular carcinoma set.

Liver Rapid Reference Set Application ( #2): Lubman - Univ of Michigan (2010) — EDRN Public Portal

Cancer.gov

We are requesting the reference set, which includes 50 HCC cases and 50 cirrhotic controls. In our preliminary study, AFP had a AUROC of 0.66 while the AUROC for the 5 glycoproteins was 0.81. The sensitivity and specificity for the 5 glycoproteins was 79% and 72% at the point that maximizes sensitivity+specificity in the ROC curve, and it was 79% and 35%, respectively, for AFP at the same point in the ROC curve. The reference set will allow us to determine the best performance of the 5 glycoproteins by themselves or whether their combination has a better sensitivity and/or specificity and AUROC. While a direct comparison with AFP will be made, the reference set will not allow a robust comparison due to the low sample size. If the glycoproteins are complementary or have better performance than AFP, then the next step would be to test them in the entire phase 2 hepatocellular carcinoma set.

The accuracy of pleural ultrasonography in diagnosing complicated parapneumonic pleural effusions.

PubMed

Svigals, Philip Z; Chopra, Amit; Ravenel, James G; Nietert, Paul J; Huggins, John T

2017-01-01

We compared the accuracy of pleural ultrasound versus chest CT versus chest radiograph (CXR) to determine radiographic complexity in predicting a complicated parapneumonic effusion (CPPE) defined by pleural fluid analysis. 66 patients with parapneumonic effusions were identified with complete data. Pleural ultrasound had a sensitivity of 69.2% (95% CI 48.2% to 85.7%) and specificity of 90.0% (95% CI 76.3% to 97.2%). Chest CT had a sensitivity of 76.9% (95% CI 56.3% to 91.0%) and specificity of 65.0% (95% CI 48.3% to 79.4%). CXR had a sensitivity of 61.5% (95% CI 40.6% to 79.8%) and specificity of 60.0% (95% CI 43.3% to 75.1%). Pleural ultrasound appears to be a superior modality to rule in a CPPE when compared with chest CT and CXR. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Comparison of real-time PCR methods for the detection of Naegleria fowleri in surface water and sediment.

PubMed

Streby, Ashleigh; Mull, Bonnie J; Levy, Karen; Hill, Vincent R

2015-05-01

Naegleria fowleri is a thermophilic free-living ameba found in freshwater environments worldwide. It is the cause of a rare but potentially fatal disease in humans known as primary amebic meningoencephalitis. Established N. fowleri detection methods rely on conventional culture techniques and morphological examination followed by molecular testing. Multiple alternative real-time PCR assays have been published for rapid detection of Naegleria spp. and N. fowleri. Foursuch assays were evaluated for the detection of N. fowleri from surface water and sediment. The assays were compared for thermodynamic stability, analytical sensitivity and specificity, detection limits, humic acid inhibition effects, and performance with seeded environmental matrices. Twenty-one ameba isolates were included in the DNA panel used for analytical sensitivity and specificity analyses. N. fowleri genotypes I and III were used for method performance testing. Two of the real-time PCR assays were determined to yield similar performance data for specificity and sensitivity for detecting N. fowleri in environmental matrices.

Comparison of real-time PCR methods for the detection of Naegleria fowleri in surface water and sediment

PubMed Central

Streby, Ashleigh; Mull, Bonnie J.; Levy, Karen

2015-01-01

Naegleria fowleri is a thermophilic free-living ameba found in freshwater environments worldwide. It is the cause of a rare but potentially fatal disease in humans known as primary amebic meningoencephalitis. Established N. fowleri detection methods rely on conventional culture techniques and morphological examination followed by molecular testing. Multiple alternative real-time PCR assays have been published for rapid detection of Naegleria spp. and N. fowleri. Four such assays were evaluated for the detection of N. fowleri from surface water and sediment. The assays were compared for thermodynamic stability, analytical sensitivity and specificity, detection limits, humic acid inhibition effects, and performance with seeded environmental matrices. Twenty-one ameba isolates were included in the DNA panel used for analytical sensitivity and specificity analyses. N. fowleri genotypes I and III were used for method performance testing. Two of the real-time PCR assays were determined to yield similar performance data for specificity and sensitivity for detecting N. fowleri in environmental matrices. PMID:25855343

Application of Sal classification to parotid gland fine-needle aspiration cytology: 10-year retrospective analysis of 312 patients.

PubMed

Kilavuz, Ahmet Erdem; Songu, Murat; İmre, Abdulkadir; Arslanoğlu, Secil; Özkul, Yilmaz; Pinar, Ercan; Ateş, Düzgün

2018-05-01

The accuracy of fine-needle aspiration biopsy (FNAB) is controversial in parotid tumors. We aimed to compare FNAB results with the final histopathological diagnosis and to apply the "Sal classification" to our data and discuss its results and its place in parotid gland cytology. The FNAB cytological findings and final histological diagnosis were assessed retrospectively in 2 different scenarios based on the distribution of nondefinitive cytology, and we applied the Sal classification and determined malignancy rate, sensitivity, and specificity for each category. In 2 different scenarios FNAB sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were found to be 81%, 87%, 54.7%, and 96.1%; and 65.3%, 100%, 100%, and 96.1%, respectively. The malignancy rates and sensitivity and specificity were also calculated and discussed for each Sal category. We believe that the Sal classification has a great potential to be a useful tool in classification of parotid gland cytology. © 2018 Wiley Periodicals, Inc.

[An exploratory study on the diagnostic cutoff value of International HIV-associated Dementia Scale in minority ethnic groups with different educational levels, in Guangxi].

PubMed

Zhao, Ting-ting; Feng, Qi-ming; Liang, Hao; Tang, Xian-yan; Wei, Bo

2011-11-01

Using Intelligence Scale of Mini Mental State Estimated (MMSE) as the gold standard to determine the relevance of International HIV-associated Dementia Scale (IHDS) in minority ethnic areas in Guangxi populations with different cultural values. Corresponding boundary value related to the authenticity and reliability on IHDS were also evaluated. 200 patients with HIV infection were randomly selected from the minority ethnic groups in Guangxi. For each infected person, MMSE and IHDS blind scale were tested at the same period. Using the results from MMSE scale test as the gold standard, ROC curve and IHDS scale in Guangxi minority populations with different education levels which related to the diagnosis of dementia-HIV values were determined. The value of a specific sector under the IHDS sensitivity, specificity, and internal consistency coefficients was also evaluated. When considering the infected person did not differ on their educational level, the IHDS scale diagnostic cutoff appeared as 8.25, while IHDS sensitivity as 0.925, specificity as 0.731 and Kappa as 0.477 (P < 0.001). When considering the extent of cultural differences did influence the prevalence of infection, the different education groups showed different IHDS diagnostic cutoff values. People with high school, secondary school or higher education levels, the IHDS diagnosis appeared to be 8.25, when sensitivity was 0.917, specificity was 0.895 and Kappa was 0.722 (P < 0.001). People with only primary education level, the IHDS appeared to be 7.25. When sensitivity was 0.875, specificity was 0.661 and Kappa was 0.372 (P < 0.001). The IHDS diagnostic sector in Guangxi minority groups was lower than the internationally recommended level of diagnostic cutoff value (IHDS ≤ 10 points). When using IHDS to perform the HIV related dementia screening program, in the minority areas of Guangxi, culture context, the degree and difference of HIV infection should be considered, especially in using IHDS diagnostic cutoff values.

Bayesian estimation of sensitivity and specificity of the modified agglutination test and bioassay for detection of Toxoplasma gondii in free-range chickens

USDA-ARS?s Scientific Manuscript database

Toxoplasma gondii infects virtually all warm-blooded animals worldwide. Serological tests, including the modified agglutination test (MAT), are often used to determine exposure to the parasite. The MAT can be used for all hosts because it does not need species-specific reagents and has been shown to...

Cut off values for abdominal obesity as a criterion of metabolic syndrome in an ethnic Kyrgyz population (Central Asian region).

PubMed

Mirrakhimov, Aibek E; Lunegova, Olga S; Kerimkulova, Alina S; Moldokeeva, Cholpon B; Nabiev, Malik P; Mirrakhimov, Erkin M

2012-02-22

People of different racial and ethnic backgrounds have a distinct pattern of central fat deposition, thus making it necessary to devise a race based approach for the diagnosis and evaluation of abdominal obesity (AO). This is the first study to determine the optimal waist circumference (WC) cutoff values for definition of AO in an ethnic Kyrgyz population. 323 persons of Kyrgyz ethnicity (183 women and 140 men), with a mean age of 51.8 ± 9.5 years old were included in the study. Measurement of blood pressure (BP), anthropometric data (including body mass index calculation and WC measurement), fasting blood sugar, serum lipid parameters and insulin were performed in all examined individuals. Insulin resistance (IR) was considered as HOMA index (insulin × fasting glucose/22.5) ≥ 2.77. Sensitivity and specificity for the presence of IR or two other criteria of MS (according to the international classification, 2009) were calculated by using receiver operating characteristic (ROC) curves for men and women separately. The optimal sensitivity and specificity obtained from the ROC curves for IR were 88 cm in women (sensitivity of 0.85, 95%CI (0.72-0.93), specificity of 0.58, 95%CI (0.49-0.66)) and 94 cm for men (sensitivity of 0.8, 95% CI (0.65-0.91), specificity of 0.61, 95% CI (0.51-0.71)). The data from the ROC curve for any two other MS criteria confirmed the results and the WC 88 cm in women (sensitivity of 0.82, 95% CI (0.72-0.9), specificity of 0.72, 95% CI (0.62-0.8)) and 94 cm in men (sensitivity of 0.74, 95% CI (0.62-0.84), specificity of 0.73, 95% CI (0.61-0.83)) were corresponded to the optimal sensitivity and specificity. WC ≥ 88 cm and ≥ 94 cm should be used as a criterion for the diagnosis of AO for Kyrgyz women and men respectively based on these results.

The after breakfast 50-g, 1-hour glucose challenge test in urban Mexican pregnant women: its sensitivity and specificity evaluated by three diagnostic criteria for gestational diabetes mellitus.

PubMed

Espinosa de los Monteros, A; Parra, A; Hidalgo, R; Zambrana, M

1999-04-01

To study the sensitivity and specificity of the 50-g, 1-hour gestational glucose challenge test performed 1 to 2 hours after a non-standardized home breakfast in urban Mexican women by using three different gestational diabetes mellitus diagnostic criteria. Four hundred and forty-five consecutive women of 24-28 weeks gestation were studied. The glucose challenge test was performed in the fed state and a week later a fasting 100-g, 3-hours oral glucose tolerance test was carried out in all of them. Duplicate serum glucose concentrations were determined by a glucose-oxidase method. Sensitivity and specificity were calculated using three different diagnostic criteria for gestational diabetes mellitus. The glucose challenge test performed as indicated, with a cutoff of 7.8 mmol/L, had 88-89% sensitivity and 85-87% specificity when using as diagnostic criteria those proposed by the National Diabetes Data Group and by Carpenter & Coustan; by using Sacks et al. criteria, the values were 82% and 88%, respectively. Considering only pregnant women > or = 25 years of age, the sensitivity increased to 92% with the National Diabetes Data Group criteria. Pregnant women < 25 years of age had significantly lower blood glucose values than those with age > or = 25 years during the glucose tolerance test. For the general group the sensitivity of the glucose challenge test performed 1 to 2 hours after breakfast was similar, based on the National Diabetes Data Group and the Carpenter & Coustan's diagnostic criteria for gestational diabetes mellitus. However, when pregnant women > or = 25 years of age were considered, the use of the former criteria yielded a slightly better sensitivity.

Proteomic biomarkers apolipoprotein A1, truncated transthyretin and connective tissue activating protein III enhance the sensitivity of CA125 for detecting early stage epithelial ovarian cancer.

PubMed

Clarke, Charlotte H; Yip, Christine; Badgwell, Donna; Fung, Eric T; Coombes, Kevin R; Zhang, Zhen; Lu, Karen H; Bast, Robert C

2011-09-01

The low prevalence of ovarian cancer demands both high sensitivity (>75%) and specificity (99.6%) to achieve a positive predictive value of 10% for successful early detection. Utilizing a two stage strategy where serum marker(s) prompt the performance of transvaginal sonography (TVS) in a limited number (2%) of women could reduce the requisite specificity for serum markers to 98%. We have attempted to improve sensitivity by combining CA125 with proteomic markers. Sera from 41 patients with early stage (I/II) and 51 with late stage (III/IV) epithelial ovarian cancer, 40 with benign disease and 99 healthy individuals, were analyzed to measure 7 proteins [Apolipoprotein A1 (Apo-A1), truncated transthyretin (TT), transferrin, hepcidin, ß-2-microglobulin (ß2M), Connective Tissue Activating Protein III (CTAPIII), and Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4)]. Statistical models were fit by logistic regression, followed by optimization of factors retained in the models determined by optimizing the Akaike Information Criterion. A validation set included 136 stage I ovarian cancers, 140 benign pelvic masses and 174 healthy controls. In a training set analysis, the 3 most effective biomarkers (Apo-A1, TT and CTAPIII) exhibited 54% sensitivity at 98% specificity, CA125 alone produced 68% sensitivity and the combination increased sensitivity to 88%. In a validation set, the marker panel plus CA125 produced a sensitivity of 84% at 98% specificity (P=0.015, McNemar's test). Combining a panel of proteomic markers with CA125 could provide a first step in a sequential two-stage strategy with TVS for early detection of ovarian cancer. Copyright © 2011. Published by Elsevier Inc.

Proteomic Biomarkers Apolipoprotein A1, Truncated Transthyretin and Connective Tissue Activating Protein III Enhance the Sensitivity of CA125 for Detecting Early Stage Epithelial Ovarian Cancer

PubMed Central

Clarke, Charlotte H.; Yip, Christine; Badgwell, Donna; Fung, Eric T.; Coombes, Kevin R.; Zhang, Zhen; Lu, Karen H.; Bast, Robert C.

2011-01-01

Objective The low prevalence of ovarian cancer demands both high sensitivity (>75%) and specificity (99.6%) to achieve a positive predictive value of 10% for successful early detection. Utilizing a two stage strategy where serum marker(s) prompt the performance of transvaginal sonography (TVS) in a limited number (2%) of women could reduce the requisite specificity for serum markers to 98%. We have attempted to improve sensitivity by combining CA125 with proteomic markers. Methods Sera from 41 patients with early stage (I/II) and 51 with late stage (III/IV) epithelial ovarian cancer, 40 with benign disease and 99 healthy individuals, were analyzed to measure 7 proteins [Apolipoprotein A1 (Apo-A1), truncated transthyretin (TT), transferrin, hepcidin, ß-2-microglobulin (ß2M), Connective Tissue Activating Protein III (CTAPIII), and Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4)]. Statistical models were fit by logistic regression, followed by optimization of factors retained in the models determined by optimizing the Akaike Information Criterion. A validation set included 136 stage I ovarian cancers, 140 benign pelvic masses and 174 healthy controls. Results In a training set analysis, the 3 most effective biomarkers (Apo-A1, TT and CTAPIII) exhibited 54% sensitivity at 98% specificity, CA125 alone produced 68% sensitivity and the combination increased sensitivity to 88%. In a validation set, the marker panel plus CA125 produced a sensitivity of 84% at 98% specificity (P= 0.015, McNemar's test). Conclusion Combining a panel of proteomic markers with CA125 could provide a first step in a sequential two-stage strategy with TVS for early detection of ovarian cancer. PMID:21708402

Assessment of insulin sensitivity from measurements in fasting state and during an oral glucose tolerance test in obese children.

PubMed

Atabek, Mehmet Emre; Pirgon, Ozgur

2007-02-01

Few previous studies have examined the validity of the fasting glucose-to-insulin ratio (FGIR), homeostasis model assessment of insulin resistance (HOMA-IR) and quantitative insulin-sensitivity check index (QUICKI) in pediatric populations. To compare simple indices of insulin resistance calculated from fasting glucose and insulin levels with insulin sensitivity indices (area under the response curve [AUCinsulin], insulin sensitivity index [ISI-compositeL) determined by oral glucose tolerance testing (OGTT) in obese children. One hundred and forty-eight obese children and adolescents (86 girls and 62 boys, mean age: 10.86 +/- 3.08 years, mean body mass index (BMI): 27.7 +/- 4.2) participated in the study. OGTT was performed in all participants. After glucose and insulin measurements from OGTT, the children were divided into two groups according to the presence or absence of insulin resistance. Insulin sensitivity indices obtained from the OGTT were compared between the groups. The total plasma glucose response and insulin secretion were evaluated from the AUC estimated by the trapezoid rule. Cut-off points, and sensitivity and specificity calculations were based on insulin resistance with receiver operating characteristic curve (ROC) analysis. The prevalence of insulin resistance, glucose intolerance and dyslipidemia was 37.1%, 24.3% and 54% in obese children, respectively. The groups consisted of 93 children without insulin resistance (54 girls and 39 boys; mean age: 10.5 +/- 3.3 years; mean BMI: 27.0 +/- 4.2) and 55 children with insulin resistance (32 girls and 23 boys; mean age: 11.4 +/- 2.5 years; mean BMI: 27.9 +/- 3.9). There were significant differences in mean FGIR (10.0 +/- 7.2 vs 5.6 +/- 2.8, p < 0.001), HOMA-IR (3.2 +/- 2.3 vs 4.9 +/- 2.3, p < 0.001) and QUICKI (0.33 +/- 0.03 vs 0.30 +/- 0.02, p < 0.001) between the groups. The cut-off points for diagnosis of insulin resistance were < 5.6 for FGIR (sensitivity 61.8, specificity 76.3), > 2.7 for HOMA-IR (sensitivity 80, specificity 59.1), and < 0.328 for QUICKI (sensitivity 80, specificity 60.2). Indices derived from fasting samples for diagnosis of insulin sensitivity are reliable criteria in obese children and adolescents. HOMA-IR and QUICKI appeared to have similar sensitivity and specificity and to have higher sensitivity than FGIR.

Aberrant DNA methylation of tumor-related genes in oral rinse: a noninvasive method for detection of oral squamous cell carcinoma.

PubMed

Nagata, Satoshi; Hamada, Tomofumi; Yamada, Norishige; Yokoyama, Seiya; Kitamoto, Sho; Kanmura, Yuji; Nomura, Masahiro; Kamikawa, Yoshiaki; Yonezawa, Suguru; Sugihara, Kazumasa

2012-09-01

The early detection of oral squamous cell carcinoma (OSCC) is important, and a screening test with high sensitivity and specificity is urgently needed. Therefore, in this study, the authors investigated the methylation status of tumor-related genes with the objective of establishing a noninvasive method for the detection of OSCC. Oral rinse samples were obtained from 34 patients with OSCC and from 24 healthy individuals (controls). The methylation status of 13 genes was determined by using methylation-specific polymerase chain reaction analysis and was quantified using a microchip electrophoresis system. Promoter methylation in each participant was screened by receiver operating characteristic analysis, and the utility of each gene's methylation status, alone and in combination with other genes, was evaluated as a tool for oral cancer detection. Eight of the 13 genes had significantly higher levels of DNA methylation in samples from patients with OSCC than in controls. The genes E-cadherin (ECAD), transmembrane protein with epidermal growth factor-like and 2 follistatin-like domains 2 (TMEFF2), retinoic acid receptor beta (RARβ), and O-6 methylguanine DNA methyltransferase (MGMT) had high sensitivity (>75%) and specificity for the detection of oral cancer. OSCC was detected with 100% sensitivity and 87.5% specificity using a combination of ECAD, TMEFF2, RARβ, and MGMT and with 97.1% sensitivity and 91.7% specificity using a combination of ECAD, TMEFF2, and MGMT. The aberrant methylation of a combination of marker genes present in oral rinse samples was used to detect OSCC with >90% sensitivity and specificity. The detection of methylated marker genes from oral rinse samples has great potential for the noninvasive detection of OSCC. Copyright © 2012 American Cancer Society.

Immunologic responses against hydrolyzed soy protein in dogs with experimentally induced soy hypersensitivity.

PubMed

Puigdemont, Anna; Brazís, Pilar; Serra, Montserrat; Fondati, Alessandra

2006-03-01

To assess whether dogs with experimentally induced type I hypersensitivity against soy protein would respond to soy hydrolysate and develop cutaneous or gastrointestinal tract reactions after intradermal and oral challenge exposure. 12 naïve Beagle pups (9 sensitized and 3 control dogs). 9 dogs were sensitized against soy protein by administration of allergens during a 90-day period. After the sensitization period, serum concentrations of soy-specific IgE were determined and an intradermal test was performed to confirm the dogs were sensitized against soy protein. An intradermal challenge test and an oral challenge test with native and hydrolyzed soy protein were conducted on 6 sensitized and 2 control dogs. High serum concentrations of soy-specific IgE and positive results for the intradermal test were observed for the 9 sensitized dogs after completion of the sesitization process. Sensitized dogs challenge exposed with hydrolyzed soy protein had a reduced inflammatory response after intradermal injection and no clinical response after an oral challenge exposure, compared with responses after intradermal and oral challenge exposure with native soy protein. Soy-sensitized dogs did not respond to oral administration of hydrolyzed soy protein. Thus, hydrolyzed soy protein may be useful in diets formulated for the management of dogs with adverse reactions to food.

Parenting Supports for Early Vocabulary Development: Specific Effects of Sensitivity and Stimulation through Infancy

PubMed Central

Vallotton, Claire; Mastergeorge, Ann; Foster, Tricia; Decker, Kalli B.; Ayoub, Catherine

2016-01-01

Growing recognition of disparities in early childhood language environments prompt examination of parent-child interactions which support vocabulary. Research links parental sensitivity and cognitive stimulation to child language, but has not explicitly contrasted their effects, nor examined how effects may change over time. We examined maternal sensitivity and stimulation throughout infancy using two observational methods – ratings of parents’ interaction qualities, and coding of discrete parenting behaviors - to assess the relative importance of these qualities to child vocabulary over time, and determine whether mothers make related changes in response to children’s development. Participants were 146 infants and mothers, assessed when infants were 14, 24, and 36 months. At 14 months, sensitivity had a stronger effect on vocabulary than did stimulation, but the effect of stimulation grew throughout toddlerhood. Mothers’ cognitive stimulation grew over time, whereas sensitivity remained stable. While discrete parenting behaviors changed with child age, there was no evidence of trade-offs between sensitive and stimulating behaviors, and no evidence that sensitivity moderated the effect of stimulation on child vocabulary. Findings demonstrate specificity of timing in the link between parenting qualities and child vocabulary which could inform early parent interventions, and supports a reconceptualization of the nature and measurement of parental sensitivity. PMID:28111526

Detection of the Peanut Allergens Ara h 2 and Ara h 6 in Human Breast Milk: Development of 2 Sensitive and Specific Sandwich ELISA Assays.

PubMed

Schocker, Frauke; Scharf, Alexandra; Kull, Skadi; Jappe, Uta

2017-01-01

Little is known about breast milk as a vehicle for tolerance development or sensitization to peanuts very early in life. Thus, well-characterized and highly sensitive detection systems for the reliable determination of peanut allergens in breast milk are mandatory. For the quantification of the marker allergens Ara h 2 and Ara h 6 in the low nanogram per milliliter range in breast milk samples of a German cohort, sensitive and highly specific sandwich ELISAs were optimized and validated. The Ara h 2 ELISA revealed a limit of detection (LOD) of 1.3 ng Ara h 2/mL and a quantification range of 2.3-250 ng/mL, the Ara h 6 ELISA showed an LOD of 0.7 ng/mL and a working range of 1.1-14.4 ng/mL. The assays showed no relevant cross-reactivity against other potentially cross-reactive legume, seed, and tree nut extracts (<0.01%, except for Ara h 1 in the Ara h 2 ELISA <0.1%). Ara h 2 was detectable in breast milk samples from 14/40 (35%) of the participants in concentrations from 2.3 to 184 ng/mL, Ara h 6 appeared in 9/40 (22.5%) of the lactating mothers between 1.1 and 9.7 ng/mL, and 1 highly positive sample with 79 ng/mL. Both allergens appeared at the same time points, but Ara h 6 in lower concentrations than Ara h 2. Sensitive and specific diagnostic tools for the determination of Ara h 2 and Ara h 6 in human breast milk were established. The kinetics of secreted Ara h 2 and Ara h 6 seem to be similar but with a difference in concentration. Follow-up investigations on their tolerogenic or sensitizing properties in breast milk become now accessible. © 2017 S. Karger AG, Basel.

Sensitivity and specificity of diagnostic ultrasound in the diagnosis of phrenic neuropathy.

PubMed

Boon, Andrea J; Sekiguchi, Hiroshi; Harper, Caitlin J; Strommen, Jeffrey A; Ghahfarokhi, Leili S; Watson, James C; Sorenson, Eric J

2014-09-30

To determine the sensitivity and specificity of B-mode ultrasound in the diagnosis of neuromuscular diaphragmatic dysfunction, including phrenic neuropathy. A prospective study of patients with dyspnea referred to the EMG laboratory over a 2-year time frame for evaluation of neuromuscular respiratory failure who were recruited consecutively and examined with ultrasound for possible diaphragm dysfunction. Sonographic outcome measures were absolute thickness of the diaphragm and degree of increased thickness with maximal inspiration. The comparison standard for diagnosis of diaphragm dysfunction was the final clinical diagnosis of clinicians blinded to the diaphragm ultrasound results, but taking into account other diagnostic workup, including chest radiographs, fluoroscopy, phrenic nerve conduction studies, diaphragm EMG, and/or pulmonary function tests. Of 82 patients recruited over a 2-year period, 66 were enrolled in the study. Sixteen patients were excluded because of inconclusive or insufficient reference testing. One hemidiaphragm could not be adequately visualized; therefore, hemidiaphragm assessment was conducted in a total of 131 hemidiaphragms in 66 patients. Of the 82 abnormal hemidiaphragms, 76 had abnormal sonographic findings (atrophy or decreased contractility). Of the 49 normal hemidiaphragms, none had a false-positive ultrasound. Diaphragmatic ultrasound was 93% sensitive and 100% specific for the diagnosis of neuromuscular diaphragmatic dysfunction. B-mode ultrasound imaging of the diaphragm is a highly sensitive and specific tool for diagnosis of neuromuscular diaphragm dysfunction. This study provides Class II evidence that diaphragmatic ultrasound performed by well-trained individuals accurately identifies patients with neuromuscular diaphragmatic respiratory failure (sensitivity 93%; specificity 100%). © 2014 American Academy of Neurology.

Sensitivity and specificity of intrathecal fluorescein and white light excitation for detecting intraoperative cerebrospinal fluid leak in endoscopic skull base surgery: a prospective study.

PubMed

Raza, Shaan M; Banu, Matei A; Donaldson, Angela; Patel, Kunal S; Anand, Vijay K; Schwartz, Theodore H

2016-03-01

The intraoperative detection of CSF leaks during endonasal endoscopic skull base surgery is critical to preventing postoperative CSF leaks. Intrathecal fluorescein (ITF) has been used at varying doses to aid in the detection of intraoperative CSF leaks. However, the sensitivity and specificity of ITF at certain dosages is unknown. A prospective database of all endoscopic endonasal procedures was reviewed. All patients received 25 mg ITF diluted in 10 ml CSF and were pretreated with dexamethasone and Benadryl. Immediately after surgery, the operating surgeon prospectively noted if there was an intraoperative CSF leak and fluorescein was identified. The sensitivity, specificity, and positive and negative predictive power of ITF for detecting intraoperative CSF leak were calculated. Factors correlating with postoperative CSF leak were determined. Of 419 patients, 35.8% of patients did not show a CSF leak. Fluorescein-tinted CSF (true positive) was noted in 59.7% of patients and 0 false positives were encountered. CSF without fluorescein staining (false negative) was noted in 4.5% of patients. The sensitivity and specificity of ITF were 92.9% and 100%, respectively. The negative and positive predictive values were 88.8% and 100%, respectively. Postoperative CSF leaks only occurred in true positives at a rate of 2.8%. ITF is extremely specific and very sensitive for detecting intraoperative CSF leaks. Although false negatives can occur, these patients do not appear to be at risk for postoperative CSF leak. The use of ITF may help surgeons prevent postoperative CSF leaks by intraoperatively detecting and confirming a watertight repair.

Quantitative image cytometry measurements of lipids, DNA, CD45 and cytokeratin for circulating tumor cell identification in a model system

NASA Astrophysics Data System (ADS)

Futia, Gregory L.; Qamar, Lubna; Behbakht, Kian; Gibson, Emily A.

2016-04-01

Circulating tumor cell (CTC) identification has applications in both early detection and monitoring of solid cancers. The rarity of CTCs, expected at ~1-50 CTCs per million nucleated blood cells (WBCs), requires identifying methods based on biomarkers with high sensitivity and specificity for accurate identification. Discovery of biomarkers with ever higher sensitivity and specificity to CTCs is always desirable to potentially find more CTCs in cancer patients thus increasing their clinical utility. Here, we investigate quantitative image cytometry measurements of lipids with the biomarker panel of DNA, Cytokeratin (CK), and CD45 commonly used to identify CTCs. We engineered a device for labeling suspended cell samples with fluorescent antibodies and dyes. We used it to prepare samples for 4 channel confocal laser scanning microscopy. The total data acquired at high resolution from one sample is ~ 1.3 GB. We developed software to perform the automated segmentation of these images into regions of interest (ROIs) containing individual cells. We quantified image features of total signal, spatial second moment, spatial frequency second moment, and their product for each ROI. We performed measurements on pure WBCs, cancer cell line MCF7 and mixed samples. Multivariable regressions and feature selection were used to determine combination features that are more sensitive and specific than any individual feature separately. We also demonstrate that computation of spatial characteristics provides higher sensitivity and specificity than intensity alone. Statistical models allowed quantification of the required sensitivity and specificity for detecting small levels of CTCs in a human blood sample.

Sensitivity and specificity of a new MRI method evaluating temporo-mandibular joint disc-condyle relationships: an in vivo study.

PubMed

Benbelaïd, R; Fleiter, B

2006-03-01

The aim of this study was to evaluate sensitivity and specificity of a new method to locate temporo-mandibular joint (TMJ) disc using magnetic resonance imaging (MRI) and analyze disc-condyle relationships, in asymptomatic subjects and patients with disc displacement. Twenty-nine sagittal MRI of 16 subjects, 8 asymptomatic volunteers and 8 subjects with anterior disc displacement, were carried out during controlled opening from intercuspal position up to a 25 mm opening. Selected sections were analyzed with a graphic computerized system of coordinates. The total surface area (TS) of disc section was separated into anterior surface area (AS) and posterior surface area. Areas were determined by computer. Two trained examiners drew images at random. The reliability of AS/TS ratio index was evaluated in a previous study. AS/TS ratio sensitivity (Se) and specificity (Sp) were calculated closed mouth, 5 mm open and 25 mm open mouth. Best sensitivity (Se=0.63) and specificity (Sp=0.81) were obtained when MRI was realized with closed mouth and 25 mm open mouth. Lower sensitivity was observed when MRI was performed either with closed mouth (Se=0.54) or 25 mm open mouth (Se=0.18). Lower specificity was observed with 5 mm open mouth (Sp=0.68). In conclusion, it was confirmed as well that MRI of anterior disc displacement should be performed with closed mouth and opened mouth. Thus, further studies are required to assess disc displacement and mechanical alterations and to evaluate the risk of direct damage on TMJ tissues.

Multivariate modelling of prostate cancer combining magnetic resonance derived T2, diffusion, dynamic contrast-enhanced and spectroscopic parameters.

PubMed

Riches, S F; Payne, G S; Morgan, V A; Dearnaley, D; Morgan, S; Partridge, M; Livni, N; Ogden, C; deSouza, N M

2015-05-01

The objectives are determine the optimal combination of MR parameters for discriminating tumour within the prostate using linear discriminant analysis (LDA) and to compare model accuracy with that of an experienced radiologist. Multiparameter MRIs in 24 patients before prostatectomy were acquired. Tumour outlines from whole-mount histology, T2-defined peripheral zone (PZ), and central gland (CG) were superimposed onto slice-matched parametric maps. T2, Apparent Diffusion Coefficient, initial area under the gadolinium curve, vascular parameters (K(trans),Kep,Ve), and (choline+polyamines+creatine)/citrate were compared between tumour and non-tumour tissues. Receiver operating characteristic (ROC) curves determined sensitivity and specificity at spectroscopic voxel resolution and per lesion, and LDA determined the optimal multiparametric model for identifying tumours. Accuracy was compared with an expert observer. Tumours were significantly different from PZ and CG for all parameters (all p < 0.001). Area under the ROC curve for discriminating tumour from non-tumour was significantly greater (p < 0.001) for the multiparametric model than for individual parameters; at 90 % specificity, sensitivity was 41 % (MRSI voxel resolution) and 59 % per lesion. At this specificity, an expert observer achieved 28 % and 49 % sensitivity, respectively. The model was more accurate when parameters from all techniques were included and performed better than an expert observer evaluating these data. • The combined model increases diagnostic accuracy in prostate cancer compared with individual parameters • The optimal combined model includes parameters from diffusion, spectroscopy, perfusion, and anatominal MRI • The computed model improves tumour detection compared to an expert viewing parametric maps.

The salivary microbiota as a diagnostic indicator of oral cancer: A descriptive, non-randomized study of cancer-free and oral squamous cell carcinoma subjects

PubMed Central

Mager, DL; Haffajee, AD; Devlin, PM; Norris, CM; Posner, MR; Goodson, JM

2005-01-01

Background The purpose of the present investigation was to determine if the salivary counts of 40 common oral bacteria in subjects with an oral squamous cell carcinoma (OSCC) lesion would differ from those found in cancer-free (OSCC-free) controls. Methods Unstimulated saliva samples were collected from 229 OSCC-free and 45 OSCC subjects and evaluated for their content of 40 common oral bacteria using checkerboard DNA-DNA hybridization. DNA counts per ml saliva were determined for each species, averaged across subjects in the 2 subject groups, and significance of differences between groups determined using the Mann-Whitney test and adjusted for multiple comparisons. Diagnostic sensitivity and specificity in detection of OSCC by levels of salivary organisms were computed and comparisons made separately between a non-matched group of 45 OSCC subjects and 229 controls and a group of 45 OSCC subjects and 45 controls matched by age, gender and smoking history. Results Counts of 3 of the 40 species tested, Capnocytophaga gingivalis, Prevotella melaninogenica and Streptococcus mitis, were elevated in the saliva of individuals with OSCC (p < 0.001). When tested as diagnostic markers the 3 species were found to predict 80% of cancer cases (sensitivity) while excluding 83% of controls (specificity) in the non-matched group. Diagnostic sensitivity and specificity in the matched group were 80% and 82% respectively. Conclusion High salivary counts of C. gingivalis, P. melaninogenica and S. mitis may be diagnostic indicators of OSCC. PMID:15987522

Increased pulsatility index supports diagnosis of vascular parkinsonism versus idiopathic Parkinson's disease.

PubMed

Caba, L M; Ferrairó, J I T; Torres, I M; Costa, J F V; Muñoz, R B; Martin, A L

2017-12-29

The diagnosis of vascular parkinsonism (VP) is based on a series of clinical criteria and neuroimaging findings. An increase in transcranial Doppler ultrasonography pulsatility index (PI) has been described as a frequent finding in patients with VP. We aimed to confirm this association and to determine the PI value with the highest sensitivity and specificity for diagnosis of VP. PI was determined in all patients admitted to Hospital Universitari i Politècnic La Fe due to parkinsonism between January 2012 and June 2016. We assessed the probability of having VP based on PI values in patients with a definite diagnosis of either VP or idiopathic Parkinson's disease (IPD). A ROC curve was created to determine the PI value with the highest sensitivity and specificity. We assessed a total of 146 patients with suspected parkinsonism; 54 (37%) were diagnosed with IPD and 15 (10%) with VP. Patients with VP were significantly older than those with IPD (mean age of 79 vs 68.5, P=.00144) and had a higher PI (median of 1.29 [IQR: 1.09-1.38] vs 0.96 [IQR: 0.89-1.16], P=.01328). In our sample, a PI of 1.09 conferred 84% sensitivity and 70% specificity. In our series, the PI was significantly higher in patients with VP than in those with IPD. We therefore support the use of transcranial Doppler ultrasonography for the initial assessment of elderly patients with akinetic-rigid syndrome. Copyright © 2017 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

[Evaluation of the diagnostic performance of Xpert MTB/RIF test for the detection of Mycobacterium tuberculosis and rifampin resistance in clinical samples].

PubMed

Gürsoy, Nafia Canan; Yakupoğulları, Yusuf; Tekerekoğlu, Mehmet Sait; Otlu, Barış

2016-04-01

Rapid and accurate detection of active tuberculosis (TB) cases is one of the most important goal of tuberculosis control programme. For this purpose, new methods are being developed to isolate, serotype and determine the drug resistance of the agent. Xpert MTB/RIF test (CepheidGeneXpert® System, USA) that has been recently developed, is a real-time polymerase chain reaction-based method which detects Mycobacterium tuberculosis complex and resistance of the strain to rifampicin (RIF) from the clinical sample directly within a couple of hours. However, there are not sufficient data about the performance of that test for extrapulmonary samples and pulmonary samples other than sputum. The aims of this study were to investigate the sensitivity, specificity, positive and negative predictive values of Xpert MTB/RIF test in detection of M. tuberculosis and the performance in the determination of rifampicin resistance of the isolates from pulmonary and extrapulmonary clinical samples. A total of 2160 clinical samples, in which 1141 (52.8%) were pulmonary and 1019 (47.2%) were extrapulmonary samples, sent to our laboratory between July 2013 to December 2014, were included in the study. Sixty seven of the evaluated samples (3.1%) were positive with microscopy (acid-fast stain; AFS), 116 samples (5.1%) were positive with culture and 98 samples (4.5%) were positive with Xpert MTB/RIF test. When the culture was considered as the reference method, the sensitivity and specificity of Xpert MTB/RIF test were determined as 73.3% and 99.3%, respectively for all samples; 77.5% and 99.5%, respectively for pulmonary samples and 63.9% and 99.2%, respectively for extrapulmonary samples. Among AFS positive samples, the sensitivity was 100% and specificity was 66.7%; whereas among AFS negative samples those values were 40.4% and 99.4%, respectively. Among all the samples involved in the study, RIF resistance was determined only in three samples with Xpert MTB/ RIF test and that was also proved phenotypically (100% concordance). According to mycobacterial culture results, positive and negative predictive values of Xpert MTB/RIF test were determined as 86.7% and 98.5%, respectively for all samples. Those were determined as 92.5% and 98.3%, respectively for extrapulmonary samples and were determined as 74.2 and 98.7%, respectively for pulmonary samples. According to the results obtained in our study, sensitivity of Xpert MTB/RIF test for extrapulmonary samples was found to be at moderate level; sensitivity of the test was found to be decreased especially in AFS negative samples with less bacilli load. Nonetheless, specificity of Xpert MTB/RIF test to the agent in all samples was found to be extremely high. In our study, although RIF-resistant strains were detected in few of the samples, Xpert MTB/ RIF test could differentiate all resistant and sensitive strains. Additionally, detection of M. tuberculosis and RIF resistance in our laboratory takes approximately 20.96 days with culture, this period decreases to a couple of hours with Xpert MTB/RIF test. Because of the advantages such as being practical, rapid and requiring minimal safety measures, it was concluded that Xpert MTB/RIF test may contribute to rapid diagnosis of TB also in extrapulmonary samples, with the confirmation of culture method.

Association of tree nut and coconut sensitizations.

PubMed

Polk, Brooke I; Dinakarpandian, Deendayal; Nanda, Maya; Barnes, Charles; Dinakar, Chitra

2016-10-01

Coconut (Cocos nucifera), despite being a drupe, was added to the US Food and Drug Administration list of tree nuts in 2006, causing potential confusion regarding the prevalence of coconut allergy among tree nut allergic patients. To determine whether sensitization to tree nuts is associated with increased odds of coconut sensitization. A single-center retrospective analysis of serum specific IgE levels to coconut, tree nuts (almond, Brazil nut, cashew, chestnut, hazelnut, macadamia, pecan, pistachio, and walnut), and controls (milk and peanut) was performed using deidentified data from January 2000 to August 2012. Spearman correlation (ρ) between coconut and each tree nut was determined, followed by hierarchical clustering. Sensitization was defined as a nut specific IgE level of 0.35 kU/L or higher. Unadjusted and adjusted associations between coconut and tree nut sensitization were tested by logistic regression. Of 298 coconut IgE values, 90 (30%) were considered positive results, with a mean (SD) of 1.70 (8.28) kU/L. Macadamia had the strongest correlation (ρ = 0.77), whereas most other tree nuts had significant (P < .05) but low correlation (ρ < 0.5) with coconut. The adjusted odds ratio between coconut and macadamia was 7.39 (95% confidence interval, 2.60-21.02; P < .001) and 5.32 (95% confidence interval, 2.18-12.95; P < .001) between coconut and almond, with other nuts not being statistically significant. Our findings suggest that although sensitization to most tree nuts appears to correlate with coconut, this is largely explained by sensitization to almond and macadamia. This finding has not previously been reported in the literature. Further study correlating these results with clinical symptoms is planned. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Food Allergy Sensitization and Presentation in Siblings of Food Allergic Children.

PubMed

Gupta, Ruchi S; Walkner, Madeline M; Greenhawt, Matthew; Lau, Claudia H; Caruso, Deanna; Wang, Xiaobin; Pongracic, Jacqueline A; Smith, Bridget

2016-01-01

Many parents of food allergic children have concerns about the development of food allergies in their other children. We sought to determine prevalence of food sensitization and clinical food allergy among siblings of food allergic children. Two thousand eight hundred and thirty-four children were enrolled in the Chicago Family Cohort Food Allergy study. One thousand one hundred and twenty children (ages 0-21 years) with a food allergy (defined by a reported reaction history and evidence of food-specific IgE or skin prick test) and at least 1 biological sibling were included in this study. Among siblings of children with food allergy, 33.4% had no sensitization and no clinical symptoms to food. Fifty-three percent had a positive food serum-specific IgE or skin prick test, but no reported symptoms of food allergy. Only 13.6% of siblings were both sensitized and clinically reactive to the same food. Milk allergy was the most common allergy among siblings (5.9%), followed by egg allergy (4.4%) and peanut allergy (3.7%). In a large cohort of food allergic families, only a small proportion of siblings were both sensitized and clinically reactive to a food. Sensitization without reactivity was common among siblings. Testing for food allergy in siblings without a history of clinical reactivity appears to be unjustified. Screening may lead to negative consequences related to potential misdiagnosis and unnecessary avoidance of a food. More data are needed to determine the absolute risk of food allergy development in siblings of food allergic children. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. All rights reserved.

Food Allergy Sensitization and Presentation in Siblings of Food Allergic Children

PubMed Central

Gupta, Ruchi; Walkner, Maddy; Greenhawt, Matthew; Lau, Claudia; Caruso, Deanna; Wang, Xiaobin; Pongracic, Jacqueline A.; Smith, Bridget

2016-01-01

Background Many parents of food allergic children have concerns about the development of food allergies in their other children. Objective We sought to determine prevalence of food sensitization and clinical food allergy among siblings of food allergic children. Methods Two thousand eight hundred and thirty-four children were enrolled in the Chicago Family Cohort Food Allergy study. One thousand one hundred and twenty children (ages 0–21 years) with a food allergy (defined by a reported reaction history and evidence of food-specific IgE or skin prick test) and at least one biological sibling were included in this study. Results Among siblings of children with food allergy, 33.4% had no sensitization and no clinical symptoms to food. Fifty-three percent had a positive food serum-specific IgE or skin prick test, but no reported symptoms of food allergy. Only 13.6% of siblings were both sensitized and clinically reactive to the same food. Milk allergy was the most common allergy among siblings (5.9%), followed by egg allergy (4.4%) and peanut allergy (3.7%). Conclusions In a large cohort of food allergic families, only a small proportion of siblings were both sensitized and clinically reactive to a food. Sensitization without reactivity was common among siblings. Testing for food allergy in siblings without a history of clinical reactivity appears to be unjustified. Screening may lead to negative consequences related to potential misdiagnosis and unnecessary avoidance of a food. More data are needed to determine the absolute risk of food allergy development in siblings of food allergic children. PMID:27421900

Evaluation of highly conserved hsp65-specific nested PCR primers for diagnosing Mycobacterium tuberculosis.

PubMed

Priyadarshini, P; Tiwari, K; Das, A; Kumar, D; Mishra, M N; Desikan, P; Nath, G

2017-02-01

To evaluate the sensitivity and specificity of a new nested set of primers designed for the detection of Mycobacterium tuberculosis complex targeting a highly conserved heat shock protein gene (hsp65). The nested primers were designed using multiple sequence alignment assuming the nucleotide sequence of the M. tuberculosis H37Rv hsp65 genome as base. Multidrug-resistant Mycobacterium species along with other non-mycobacterial and fungal species were included to evaluate the specificity of M. tuberculosis hsp65 gene-specific primers. The sensitivity of the primers was determined using serial 10-fold dilutions, and was 100% as shown by the bands in the case of M. tuberculosis complex. None of the other non M. tuberculosis complex bacterial and fungal species yielded any band on nested polymerase chain reaction (PCR). The first round of amplification could amplify 0.3 ng of the template DNA, while nested PCR could detect 0.3 pg. The present hsp65-specific primers have been observed to be sensitive, specific and cost-effective, without requiring interpretation of biochemical tests, real-time PCR, sequencing or high-performance liquid chromatography. These primer sets do not have the drawbacks associated with those protocols that target insertion sequence 6110, 16S rDNA, rpoB, recA and MPT 64.

Comparison of Conventional PCR, Multiplex PCR, and Loop-Mediated Isothermal Amplification Assays for Rapid Detection of Arcobacter Species

PubMed Central

Wang, Xiaoyu; Seo, Dong Joo; Lee, Min Hwa

2014-01-01

This study aimed to develop a loop-mediated isothermal amplification (LAMP) method for the rapid detection of Arcobacter species. Specific primers targeting the 23S ribosomal RNA gene were used to detect Arcobacter butzleri, Arcobacter cryaerophilus, and Arcobacter skirrowii. The specificity of the LAMP primer set was assessed using DNA samples from a panel of Arcobacter and Campylobacter species, and the sensitivity was determined using serial dilutions of Arcobacter species cultures. LAMP showed a 10- to 1,000-fold-higher sensitivity than multiplex PCR, with a detection limit of 2 to 20 CFU per reaction in vitro. Whereas multiplex PCR showed cross-reactivity with Campylobacter species, the LAMP method developed in this study was more sensitive and reliable than conventional PCR or multiplex PCR for the detection of Arcobacter species. PMID:24478488

Sensitivity, Specificity, and Receiver Operating Characteristics: A Primer for Neuroscience Nurses.

PubMed

McNett, Molly; Amato, Shelly; Olson, DaiWai M

2017-04-01

It is important for neuroscience nurses to have a solid understanding of the instruments they use in clinical practice. Specifically, when reviewing reports of research instruments, nurses should be knowledgeable of analytical terms when determining the applicability of instruments for use in clinical practice. The purpose of this article is to review 3 such analytical terms: sensitivity, specificity, and receiver operating characteristic curves. Examples of how these terms are used in the neuroscience literature highlight the relevance of these terms to neuroscience nursing practice. As the role of the nurse continues to expand, it is important not to simply accept all instruments as valid but to be able to critically evaluate their properties for applicability to nursing practice and evidence-based care of our patients.

The optimum time to employ telephotoscreening to detect retinopathy of prematurity.

PubMed Central

Yen, K G; Hess, D; Burke, B; Johnson, R A; Feuer, W J; Flynn, J T

2000-01-01

PURPOSE: Labor-intensive screening of infants in the neonatal intensive care units is the only way to detect retinopathy of prematurity (ROP). Our purpose is to determine if RetCam 120 photos, acquired by a neonatal nurse, can be used to screen for ROP by performing 2 screening examinations, at 32 to 34 weeks (exam 1) and at 38 to 40 weeks (exam 2) post-conceptional age. METHODS: RetCam examinations are performed by a nurse on infants at exam 1 and exam 2 intervals. At the same time, an examination is performed by an experienced ophthalmologist. Masked readers evaluate the photos for ROP and determine if each eye will progress to prethreshold or threshold disease. The data are compared to the clinical course of the eyes. RESULTS: Forty-six eyes were photographed at exam 1 and 50 eyes at exam 2 from July 1, 1999, to December 15, 1999. Sensitivity and specificity of detecting ROP were 76% and 100% for exam 2 and 46% and 100% for exam 1. Sensitivity and specificity of predicting prethreshold disease were 64% and 97% for exam 2 and 33% and 100% for exam 1. Sensitivity and specificity of predicting threshold were both 100% at exam 2 and 0% (one photo in category) and 95% at exam 1. CONCLUSION: A potential reason for low sensitivity is technical limitations of the Retcam, such as the difficulty in capturing peripheral retina in small eyes and the need for a better lid speculum. Images FIGURE 1 FIGURE 2A FIGURE 2B FIGURE 3 PMID:11190018

Preliminary development of an ultrabrief two-item bedside test for delirium.

PubMed

Fick, Donna M; Inouye, Sharon K; Guess, Jamey; Ngo, Long H; Jones, Richard N; Saczynski, Jane S; Marcantonio, Edward R

2015-10-01

Delirium is common, morbid, and costly, yet is greatly under-recognized among hospitalized older adults. To identify the best single and pair of mental status test items that predict the presence of delirium. Diagnostic test evaluation study that enrolled medicine inpatients aged 75 years or older at an academic medical center. Patients underwent a clinical reference standard assessment involving a patient interview, medical record review, and interviews with family members and nurses to determine the presence or absence of Diagnostic and Statistical Manual of Mental Disorders, 4th Edition defined delirium. Participants also underwent the three-dimensional Confusion Assessment Method (3D-CAM), a brief, validated assessment for delirium. Individual items and pairs of items from the 3D-CAM were evaluated to determine sensitivity and specificity relative to the reference standard delirium diagnosis. Of the 201 participants (mean age 84 years, 62% female), 42 (21%) had delirium based on the clinical reference standard. The single item with the best test characteristics was "months of the year backwards" with a sensitivity of 83% (95% confidence interval [CI]: 69%-93%) and specificity of 69% (95% CI: 61%-76%). The best 2-item screen was the combination of "months of the year backwards" and "what is the day of the week?" with a sensitivity of 93% (95% CI: 81%-99%) and specificity of 64% (95% CI: 56%-70%). We identified a single item with >80% and pair of items with >90% sensitivity for delirium. If validated prospectively, these items will serve as an initial innovative screening step for delirium identification in hospitalized older adults. © 2015 Society of Hospital Medicine.

The molecular basis of the specificity of action of KATP channel openers

PubMed Central

Moreau, Christophe; Jacquet, Hélène; Prost, Anne-Lise; D’hahan, Nathalie; Vivaudou, Michel

2000-01-01

KATP channels incorporate a regulatory subunit of the ATP-binding cassette (ABC) transporter family, the sulfonylurea receptor (SUR), which defines their pharmacology. The therapeutically important K+ channel openers (e.g. pinacidil, cromakalim, nicorandil) act specifically on the SUR2 muscle isoforms but, except for diazoxide, remain ineffective on the SUR1 neuronal/pancreatic isoform. This SUR1/2 dichotomy underpinned a chimeric strategy designed to identify the structural determinants of opener action, which led to a minimal set of two residues within the last transmembrane helix of SUR. Transfer of either residue from SUR2A to SUR1 conferred opener sensitivity to SUR1, while the reverse operation abolished SUR2A sensitivity. It is therefore likely that these residues form part of the site of interaction of openers with the channel. Thus, openers would target a region that, in other ABC transporters, is known to be tightly involved with the binding of substrates and other ligands. This first glimpse of the site of action of pharmacological openers should permit rapid progress towards understanding the structural determinants of their affinity and specificity. PMID:11118199

Sensitivity and Specificity of 50% Excess Weight Loss (50%EWL) and Twelve Other Bariatric Criteria for Weight Loss Success.

PubMed

van de Laar, Arnold W; van Rijswijk, A S; Kakar, H; Bruin, S C

2018-02-27

Criteria for bariatric weight loss success are numerous. Most of them are arbitrary. None of them is evidence-based. Our objective was to determine their sensitivity and specificity. Thirteen common bariatric weight loss criteria were compared to a benchmark reflecting the gold standard in bariatric surgery. We used an elaborate baseline BMI-independent weight loss percentile chart, based on retrospective data after laparoscopic Roux-en-Y gastric bypass (LRYGB), performed between 2007 and 2017. Percentile curves p31.6 (patients' expectation), p25 (interquartile range), p15.9 (1 standard deviation (SD) below median), and p10.9 (surgeons' goal) were used as possible cutoff for success to determine true or false positive and negative results beyond 1 year. We operated 4497 primary LRYGB patients, with mean follow-up 22 (± 1 SD 19; range 0-109) months, 3031 patients with last result ≥ 1 year, 518 ≥ 5 years. For all four cutoff percentile curves for success, specificities were low (2-72%) for criteria < 35 body mass index (BMI), ≥ 25percentage excess BMI loss (%EBMIL), ≥ 50%EBMIL, ≥ 15 percentage total weight loss (%TWL), ≥ 20%TWL, ≥ 25 percentage excess weight loss (%EWL), and high (83-96%) for < 30 BMI. No criterion had > 80% specificity and sensitivity for a cutoff above p15.9. For p15.9, they were both > 80% for criteria ≥ 10 BMI reduction and ≥ 50%EWL, both > 90% for ≥ 25%TWL and ≥ 35 percentage alterable weight loss (%AWL). All criteria had high sensitivities for all cutoff percentile curves (87-100%), except < 30 BMI (65-78%). For the first time, common bariatric criteria for weight loss success were systematically validated. Most criteria recognized success very well (high sensitivities), but ≥ 15%TWL, ≥ 20%TWL, < 35BMI, ≥ 25%EWL, ≥ 25%EBMIL, and ≥ 50%EBMIL left too many poor responders unnoticed (low specificities). Bariatric weight loss success is best assessed by comparing results to percentile curve 1 SD below median (p15.9) in a bariatric baseline BMI-independent weight loss percentile chart. Criteria ≥ 35%AWL and ≥ 25%TWL came close to that curve, both with > 90% sensitivity and specificity. Among others, criterion ≥ 50%EBMIL did not.

Genotypic, Phenotypic and Clinical Validation of GeneXpert in Extra-Pulmonary and Pulmonary Tuberculosis in India

PubMed Central

Singh, Urvashi B.; Pandey, Pooja; Mehta, Girija; Bhatnagar, Anuj K.; Mohan, Anant; Goyal, Vinay; Ahuja, Vineet; Ramachandran, Ranjani; Sachdeva, Kuldeep S.; Samantaray, Jyotish C.

2016-01-01

Background Newer molecular diagnostics have brought paradigm shift in early diagnosis of tuberculosis [TB]. WHO recommended use of GeneXpert MTB/RIF [Xpert] for Extra-pulmonary [EP] TB; critics have since questioned its efficiency. Methods The present study was designed to assess the performance of GeneXpert in 761 extra-pulmonary and 384 pulmonary specimens from patients clinically suspected of TB and compare with Phenotypic, Genotypic and Composite reference standards [CRS]. Results Comparison of GeneXpert results to CRS, demonstrated sensitivity of 100% and 90.68%, specificity of 100% and 99.62% for pulmonary and extra-pulmonary samples. On comparison with culture, sensitivity for Rifampicin [Rif] resistance detection was 87.5% and 81.82% respectively, while specificity was 100% for both pulmonary and extra-pulmonary TB. On comparison to sequencing of rpoB gene [Rif resistance determining region, RRDR], sensitivity was respectively 93.33% and 90% while specificity was 100% in both pulmonary and extra-pulmonary TB. GeneXpert assay missed 533CCG mutation in one sputum and dual mutation [517 & 519] in one pus sample, detected by sequencing. Sequencing picked dual mutation [529, 530] in a sputum sample sensitive to Rif, demonstrating, not all RRDR mutations lead to resistance. Conclusions Current study reports observations in a patient care setting in a high burden region, from a large collection of pulmonary and extra-pulmonary samples and puts to rest questions regarding sensitivity, specificity, detection of infrequent mutations and mutations responsible for low-level Rif resistance by GeneXpert. Improvements in the assay could offer further improvement in sensitivity of detection in different patient samples; nevertheless it may be difficult to improve sensitivity of Rif resistance detection if only one gene is targeted. Assay specificity was high both for TB detection and Rif resistance detection. Despite a few misses, the assay offers major boost to early diagnosis of TB and MDR-TB, in difficult to diagnose pauci-bacillary TB. PMID:26894283

Validation of time to task performance assessment method in simulation: A comparative design study.

PubMed

Shinnick, Mary Ann; Woo, Mary A

2018-05-01

There is a lack of objective and valid measures for assessing nursing clinical competence which could adversely impact patient safety. Therefore, we evaluated an objective assessment of clinical competence, Time to Task (ability to perform specific, critical nursing care activities within 5 min), and compared it to two subjective measures, (Lasater Clinical Judgement Rubric [LCJR] and common "pass/fail" assessment). Using a prospective, "Known Groups" (Expert vs. Novice nurses) comparative design, Expert nurses (ICU nurses with >5 years of ICU experience) and Novice nurses (senior prelicensure nursing students) participated individually in a simulation of a patient in decompensated heart failure. Fourteen nursing instructors or preceptors, blinded to group assignment, reviewed 28 simulation videos (15 Expert and 13 Novice) and scored them using the LCJR and pass/fail assessments. Time to Task assessment was scored based on time thresholds for specific nursing actions prospectively set by an expert clinical panel. Statistical analysis consisted of Medians Test and sensitivity and specificity analyses. The LCJR total score was significantly different between Experts and Novices (p < 0.01) and revealed adequate sensitivity (ability to correctly identify "Expert" nurses; 0.72) but had a low specificity (ability to correctly identify "Novice" nurses; 0.40). For the subjective measure 'pass/fail', sensitivity was high (0.90) but specificity was low (0.47). The Time to Task measure had statistical significance between Expert and Novice groups (p < 0.01) and sensitivity (0.80) and specificity (0.85) were good. Commonly used subjective measures of clinical nursing competence have difficulties with achieving acceptable specificity. However, an objective measure, Time to Task, had good sensitivity and specificity in differentiating between groups. While more than one assessment instrument should be used to determine nurse competency, an objective measure, such as Time to Task, warrants further study. Copyright © 2018 Elsevier Ltd. All rights reserved.

A novel restriction endonuclease GlaI for rapid and highly sensitive detection of DNA methylation coupled with isothermal exponential amplification reaction.

PubMed

Sun, Yueying; Sun, Yuanyuan; Tian, Weimin; Liu, Chenghui; Gao, Kejian; Li, Zhengping

2018-02-07

Sensitive and accurate detection of site-specific DNA methylation is of critical significance for early diagnosis of human diseases, especially cancers. Herein, for the first time we employ a novel methylation-dependent restriction endonuclease GlaI to detect site-specific DNA methylation in a highly specific and sensitive way by coupling with isothermal exponential amplification reaction (EXPAR). GlaI can only cut the methylated target site with excellent selectivity but leave the unmethylated DNA intact. Then the newly exposed end fragments of methylated DNA can trigger EXPAR for highly efficient signal amplification while the intact unmethylated DNA will not initiate EXPAR at all. As such, only the methylated DNA is quantitatively and faithfully reflected by the real-time fluorescence signal of the GlaI-EXPAR system, and the potential false positive interference from unmethylated DNA can be effectively eliminated. Therefore, by integrating the unique features of GlaI for highly specific methylation discrimination and EXPAR for rapid and powerful signal amplification, the elegant GlaI-EXPAR assay allows the direct quantification of methylated DNA with ultrahigh sensitivity and accuracy. The detection limit of methylated DNA target has been pushed down to the aM level and the whole detection process of GlaI-EXPAR can be accomplished within a short time of 2 h. More importantly, ultrahigh specificity is achieved and as low as 0.01% methylated DNA can be clearly identified in the presence of a large excess of unmethylated DNA. This GlaI-EXPAR is also demonstrated to be capable of determining site-specific DNA methylations in real genomic DNA samples. Sharing the distinct advantages of ultrahigh sensitivity, outstanding specificity and facile operation, this new GlaI-EXPAR strategy may provide a robust and reliable platform for the detection of site-specific DNA methylations with low abundances.

Blood DNA methylation biomarkers predict clinical reactivity in food-sensitized infants.

PubMed

Martino, David; Dang, Thanh; Sexton-Oates, Alexandra; Prescott, Susan; Tang, Mimi L K; Dharmage, Shyamali; Gurrin, Lyle; Koplin, Jennifer; Ponsonby, Anne-Louise; Allen, Katrina J; Saffery, Richard

2015-05-01

The diagnosis of food allergy (FA) can be challenging because approximately half of food-sensitized patients are asymptomatic. Current diagnostic tests are excellent makers of sensitization but poor predictors of clinical reactivity. Thus oral food challenges (OFCs) are required to determine a patient's risk of reactivity. We sought to discover genomic biomarkers of clinical FA with utility for predicting food challenge outcomes. Genome-wide DNA methylation (DNAm) profiling was performed on blood mononuclear cells from volunteers who had undergone objective OFCs, concurrent skin prick tests, and specific IgE tests. Fifty-eight food-sensitized patients (aged 11-15 months) were assessed, half of whom were clinically reactive. Thirteen nonallergic control subjects were also assessed. Reproducibility was assessed in an additional 48 samples by using methylation data from an independent population of patients with clinical FA. Using a supervised learning approach, we discovered a DNAm signature of 96 CpG sites that predict clinical outcomes. Diagnostic scores were derived from these 96 methylation sites, and cutoffs were determined in a sensitivity analysis. Methylation biomarkers outperformed allergen-specific IgE and skin prick tests for predicting OFC outcomes. FA status was correctly predicted in the replication cohort with an accuracy of 79.2%. DNAm biomarkers with clinical utility for predicting food challenge outcomes are readily detectable in blood. The development of this technology in detailed follow-up studies will yield highly innovative diagnostic assays. Copyright © 2015 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

Mechanism of action of hypoglycemic effects of an intestine-specific inhibitor of microsomal triglyceride transfer protein (MTP) in obese rats.

PubMed

Sakata, Shohei; Katsumi, Sohei; Mera, Yasuko; Kuroki, Yukiharu; Nashida, Reiko; Kakutani, Makoto; Ohta, Takeshi

2015-01-01

Diminished insulin sensitivity in the peripheral tissues and failure of pancreatic beta cells to secrete insulin are known major determinants of type 2 diabetes mellitus. JTT-130, an intestine-specific microsomal transfer protein inhibitor, has been shown to suppress high fat-induced obesity and ameliorate impaired glucose tolerance while enhancing glucagon-like peptide-1 (GLP-1) secretion. We investigated the effects of JTT-130 on glucose metabolism and elucidated the mechanism of action, direct effects on insulin sensitivity and glucose-stimulated insulin secretion in a high fat diet-induced obesity rat model. Male Sprague Dawley rats fed a high-fat diet were treated with a single administration of JTT-130. Glucose tolerance, hyperglycemic clamp and hyperinsulinemic-euglycemic testing were performed to assess effects on insulin sensitivity and glucose-stimulated insulin secretion, respectively. Plasma GLP-1 and tissue triglyceride content were also determined under the same conditions. A single administration of JTT-130 suppressed plasma glucose elevations after oral glucose loading and increased the disposition index while elevating GLP-1. JTT-130 also enhanced glucose-stimulated insulin secretion in hyperglycemic clamp tests, whereas increased insulin sensitivity was observed in hyperinsulinemic-euglycemic clamp tests. Single-dose administration of JTT-130 decreased lipid content in the liver and skeletal muscle. JTT-130 demonstrated acute and direct hypoglycemic effects by enhancing insulin secretion and/or insulin sensitivity. Copyright © 2014 Japanese Pharmacological Society. Production and hosting by Elsevier B.V. All rights reserved.

A rapid and sensitive LC-MS/MS method for the determination of Pulsatilla saponin D in rat plasma and its application in a rat pharmacokinetic and bioavailability study.

PubMed

Ouyang, Hui; Guo, Yicheng; He, Mingzhen; Zhang, Jinlian; Huang, Xiaofang; Zhou, Xin; Jiang, Hongliang; Feng, Yulin; Yang, Shilin

2015-03-01

A simple, sensitive and specific liquid chromatography-tandem mass spectrometry method was developed and validated for the determination of Pulsatilla saponin D, a potential antitumor constituent isolated from Pulsatilla chinensis in rat plasma. Rat plasma samples were pretreated by protein precipitation with methanol. The method validation was performed in accordance with US Food and Drug Administration guidelines and the results met the acceptance criteria. The method was successfully applied to assess the pharmacokinetics and oral bioavailability of Pulsatilla saponin D in rats. Copyright © 2014 John Wiley & Sons, Ltd.

Diagnostic performance of optical coherence tomography ganglion cell--inner plexiform layer thickness measurements in early glaucoma.

PubMed

Mwanza, Jean-Claude; Budenz, Donald L; Godfrey, David G; Neelakantan, Arvind; Sayyad, Fouad E; Chang, Robert T; Lee, Richard K

2014-04-01

To evaluate the glaucoma diagnostic performance of ganglion cell inner-plexiform layer (GCIPL) parameters used individually and in combination with retinal nerve fiber layer (RNFL) or optic nerve head (ONH) parameters measured with Cirrus HD-OCT (Carl Zeiss Meditec, Inc, Dublin, CA). Prospective cross-sectional study. Fifty patients with early perimetric glaucoma and 49 age-matched healthy subjects. Three peripapillary RNFL and 3 macular GCIPL scans were obtained in 1 eye of each participant. A patient was considered glaucomatous if at least 2 of the 3 RNFL or GCIPL scans had the average or at least 1 sector measurement flagged at 1% to 5% or less than 1%. The diagnostic performance was determined for each GCIPL, RNFL, and ONH parameter as well as for binary or-logic and and-logic combinations of GCIPL with RNFL or ONH parameters. Sensitivity, specificity, positive likelihood ratio (PLR), and negative likelihood ratio (NLR). Among GCIPL parameters, the minimum had the best diagnostic performance (sensitivity, 82.0%; specificity, 87.8%; PLR, 6.69; and NLR, 0.21). Inferior quadrant was the best RNFL parameter (sensitivity, 74%; specificity, 95.9%; PLR, 18.13; and NLR, 0.27), as was rim area (sensitivity, 68%; specificity, 98%; PLR, 33.3; and NLR, 0.33) among ONH parameters. The or-logic combination of minimum GCIPL and average RNFL provided the overall best diagnostic performance (sensitivity, 94%; specificity, 85.7%; PRL, 6.58; and NLR, 0.07) as compared with the best RNFL, best ONH, and best and-logic combination (minimum GCIPL and inferior quadrant RNFL; sensitivity, 64%; specificity, 100%; PLR, infinity; and NPR, 0.36). The binary or-logic combination of minimum GCIPL and average RNFL or rim area provides better diagnostic performances than those of and-logic combinations or best single GCIPL, RNFL, or ONH parameters. This finding may be clinically valuable for the diagnosis of early glaucoma. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Detection of compression vessels in trigeminal neuralgia by surface-rendering three-dimensional reconstruction of 1.5- and 3.0-T magnetic resonance imaging.

PubMed

Shimizu, Masahiro; Imai, Hideaki; Kagoshima, Kaiei; Umezawa, Eriko; Shimizu, Tsuneo; Yoshimoto, Yuhei

2013-01-01

Surface-rendered three-dimensional (3D) 1.5-T magnetic resonance (MR) imaging is useful for presurgical simulation of microvascular decompression. This study compared the sensitivity and specificity of 1.5- and 3.0-T surface-rendered 3D MR imaging for preoperative identification of the compression vessels of trigeminal neuralgia. One hundred consecutive patients underwent microvascular decompression for trigeminal neuralgia. Forty and 60 patients were evaluated by 1.5- and 3.0-T MR imaging, respectively. Three-dimensional MR images were constructed on the basis of MR imaging, angiography, and venography data and evaluated to determine the compression vessel before surgery. MR imaging findings were compared with the microsurgical findings to compare the sensitivity and specificity of 1.5- and 3.0-T MR imaging. The agreement between MR imaging and surgical findings depended on the compression vessels. For superior cerebellar artery, 1.5- and 3.0-T MR imaging had 84.4% and 82.7% sensitivity and 100% and 100% specificity, respectively. For anterior inferior cerebellar artery, 1.5- and 3.0-T MR imaging had 33.3% and 50% sensitivity and 92.9% and 95% specificity, respectively. For the petrosal vein, 1.5- and 3.0-T MR imaging had 75% and 64.3% sensitivity and 79.2% and 78.1% specificity, respectively. Complete pain relief was obtained in 36 of 40 and 55 of 60 patients undergoing 1.5- and 3.0-T MR imaging, respectively. The present study showed that both 1.5- and 3.0-T MR imaging provided high sensitivity and specificity for preoperative assessment of the compression vessels of trigeminal neuralgia. Preoperative 3D imaging provided very high quality presurgical simulation, resulting in excellent clinical outcomes. Copyright © 2013 Elsevier Inc. All rights reserved.

Automated analysis of retinal images for detection of referable diabetic retinopathy.

PubMed

Abràmoff, Michael D; Folk, James C; Han, Dennis P; Walker, Jonathan D; Williams, David F; Russell, Stephen R; Massin, Pascale; Cochener, Beatrice; Gain, Philippe; Tang, Li; Lamard, Mathieu; Moga, Daniela C; Quellec, Gwénolé; Niemeijer, Meindert

2013-03-01

The diagnostic accuracy of computer detection programs has been reported to be comparable to that of specialists and expert readers, but no computer detection programs have been validated in an independent cohort using an internationally recognized diabetic retinopathy (DR) standard. To determine the sensitivity and specificity of the Iowa Detection Program (IDP) to detect referable diabetic retinopathy (RDR). In primary care DR clinics in France, from January 1, 2005, through December 31, 2010, patients were photographed consecutively, and retinal color images were graded for retinopathy severity according to the International Clinical Diabetic Retinopathy scale and macular edema by 3 masked independent retinal specialists and regraded with adjudication until consensus. The IDP analyzed the same images at a predetermined and fixed set point. We defined RDR as more than mild nonproliferative retinopathy and/or macular edema. A total of 874 people with diabetes at risk for DR. Sensitivity and specificity of the IDP to detect RDR, area under the receiver operating characteristic curve, sensitivity and specificity of the retinal specialists' readings, and mean interobserver difference (κ). The RDR prevalence was 21.7% (95% CI, 19.0%-24.5%). The IDP sensitivity was 96.8% (95% CI, 94.4%-99.3%) and specificity was 59.4% (95% CI, 55.7%-63.0%), corresponding to 6 of 874 false-negative results (none met treatment criteria). The area under the receiver operating characteristic curve was 0.937 (95% CI, 0.916-0.959). Before adjudication and consensus, the sensitivity/specificity of the retinal specialists were 0.80/0.98, 0.71/1.00, and 0.91/0.95, and the mean intergrader κ was 0.822. The IDP has high sensitivity and specificity to detect RDR. Computer analysis of retinal photographs for DR and automated detection of RDR can be implemented safely into the DR screening pipeline, potentially improving access to screening and health care productivity and reducing visual loss through early treatment.

Sensitivity and specificity of antibodies against HPV16 E6 and other early proteins for the detection of HPV16-driven oropharyngeal squamous cell carcinoma.

PubMed

Holzinger, Dana; Wichmann, Gunnar; Baboci, Lorena; Michel, Angelika; Höfler, Daniela; Wiesenfarth, Manuel; Schroeder, Lea; Boscolo-Rizzo, Paolo; Herold-Mende, Christel; Dyckhoff, Gerhard; Boehm, Andreas; Del Mistro, Annarosa; Bosch, Franz X; Dietz, Andreas; Pawlita, Michael; Waterboer, Tim

2017-06-15

To determine the sensitivity and specificity of HPV16 serology as diagnostic marker for HPV16-driven oropharyngeal squamous cell carcinoma (OPSCC), 214 HNSCC patients from Germany and Italy with fresh-frozen tumor tissues and sera collected before treatment were included in this study. Hundred and twenty cancer cases were from the oropharynx and 94 were from head and neck cancer regions outside the oropharynx (45 oral cavity, 12 hypopharynx and 35 larynx). Serum antibodies to early (E1, E2, E6 and E7) and late (L1) HPV16 proteins were analyzed by multiplex serology and were compared to tumor HPV RNA status as the gold standard. A tumor was defined as HPV-driven in the presence of HPV16 DNA and HPV16 transformation-specific RNA transcript patterns (E6*I, E1 ∧ E4 and E1C). Of 120 OPSCC, 66 (55%) were HPV16-driven. HPV16 E6 seropositivity was the best predictor of HPV16-driven OPSCC (diagnostic accuracy 97% [95%CI 92-99%], Cohen's kappa 0.93 [95%CI 0.8-1.0]). Of the 66 HPV-driven OPSCC, 63 were HPV16 E6 seropositive, compared to only one (1.8%) among the 54 non-HPV-driven OPSCC, resulting in a sensitivity of 96% (95%CI 88-98) and a specificity of 98% (95%CI 90-100). Of 94 HNSCC outside the oropharynx, six (6%) were HPV16-driven. In these patients, HPV16 E6 seropositivity had lower sensitivity (50%, 95%CI 19-81), but was highly specific (100%, 95%CI 96-100). In conclusion, HPV16 E6 seropositivity appears to be a highly reliable diagnostic marker for HPV16-driven OPSCC with very high sensitivity and specificity, but might be less sensitive for HPV16-driven HNSCC outside the oropharynx. © 2017 UICC.

Novel high-speed droplet-allele specific-polymerase chain reaction: application in the rapid genotyping of single nucleotide polymorphisms.

PubMed

Taira, Chiaki; Matsuda, Kazuyuki; Yamaguchi, Akemi; Sueki, Akane; Koeda, Hiroshi; Takagi, Fumio; Kobayashi, Yukihiro; Sugano, Mitsutoshi; Honda, Takayuki

2013-09-23

Single nucleotide alterations such as single nucleotide polymorphisms (SNP) and single nucleotide mutations are associated with responses to drugs and predisposition to several diseases, and they contribute to the pathogenesis of malignancies. We developed a rapid genotyping assay based on the allele-specific polymerase chain reaction (AS-PCR) with our droplet-PCR machine (droplet-AS-PCR). Using 8 SNP loci, we evaluated the specificity and sensitivity of droplet-AS-PCR. Buccal cells were pretreated with proteinase K and subjected directly to the droplet-AS-PCR without DNA extraction. The genotypes determined using the droplet-AS-PCR were then compared with those obtained by direct sequencing. Specific PCR amplifications for the 8 SNP loci were detected, and the detection limit of the droplet-AS-PCR was found to be 0.1-5.0% by dilution experiments. Droplet-AS-PCR provided specific amplification when using buccal cells, and all the genotypes determined within 9 min were consistent with those obtained by direct sequencing. Our novel droplet-AS-PCR assay enabled high-speed amplification retaining specificity and sensitivity and provided ultra-rapid genotyping. Crude samples such as buccal cells were available for the droplet-AS-PCR assay, resulting in the reduction of the total analysis time. Droplet-AS-PCR may therefore be useful for genotyping or the detection of single nucleotide alterations. Copyright © 2013 Elsevier B.V. All rights reserved.

Do race-specific definitions of short long bones improve the detection of down syndrome on second-trimester genetic sonograms?

PubMed

Harper, Lorie M; Gray, Diana; Dicke, Jeffrey; Stamilio, David M; Macones, George A; Odibo, Anthony O

2010-02-01

The purpose of this study was to determine whether the use of race-specific definitions of short femur and humerus lengths improves Down syndrome detection. This was a retrospective cohort study over 16 years. For each self-reported maternal race (white, African American, Hispanic, and Asian), we evaluated the efficiency of Down syndrome detection using published race-specific formulas compared with a standard formula for short femur and humerus lengths (observed versus expected lengths < or =0.91 and < or =0.89, respectively). The sensitivity, specificity, and 95% confidence intervals for each parameter were compared. Screening performance was compared by areas under the receiver operating characteristic curves. Of 58,710 women, 209 (0.3%) had a diagnosis of a fetus with Down syndrome. Although the race-based formula increased sensitivity in each population, the increase was statistically significant only in the white population, whereas a decrease in specificity was statistically significant in all 4 populations, as denoted by nonoverlapping confidence intervals. The area under the receiver operating characteristic curve for the model using the race-specific definition of short femur length was 0.67 versus 0.65 compared with the standard definition, and for humerus length it was 0.70 versus 0.71. The use of race-based formulas for the determination of short femur and humerus lengths did not significantly improve the detection rates for Down syndrome.

A highly sensitive and specific capacitive aptasensor for rapid and label-free trace analysis of Bisphenol A (BPA) in canned foods.

PubMed

Mirzajani, Hadi; Cheng, Cheng; Wu, Jayne; Chen, Jiangang; Eda, Shigotoshi; Najafi Aghdam, Esmaeil; Badri Ghavifekr, Habib

2017-03-15

A rapid, highly sensitive, specific and low-cost capacitive affinity biosensor is presented here for label-free and single step detection of Bisphenol A (BPA). The sensor design allows rapid prototyping at low-cost using printed circuit board material by benchtop equipment. High sensitivity detection is achieved through the use of a BPA-specific aptamer as probe molecule and large electrodes to enhance AC-electroelectrothermal effect for long-range transport of BPA molecules toward electrode surface. Capacitive sensing technique is used to determine the bounded BPA level by measuring the sample/electrode interfacial capacitance of the sensor. The developed biosensor can detect BPA level in 20s and exhibits a large linear range from 1 fM to 10 pM, with a limit of detection (LOD) of 152.93 aM. This biosensor was applied to test BPA in canned food samples and could successfully recover the levels of spiked BPA. This sensor technology is demonstrated to be highly promising and reliable for rapid, sensitive and on-site monitoring of BPA in food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Does body mass index misclassify physically active young men.

PubMed

Grier, Tyson; Canham-Chervak, Michelle; Sharp, Marilyn; Jones, Bruce H

2015-01-01

The purpose of this analysis was to determine the accuracy of age and gender adjusted BMI as a measure of body fat (BF) in U.S. Army Soldiers. BMI was calculated through measured height and weight (kg/m(2)) and body composition was determined by dual energy X-ray absorptiometry (DEXA). Linear regression was used to determine a BF prediction equation and examine the correlation between %BF and BMI. The sensitivity and specificity of BMI compared to %BF as measured by DEXA was calculated. Soldiers (n = 110) were on average 23 years old, with a BMI of 26.4, and approximately 18% BF. The correlation between BMI and %BF (R = 0.86) was strong (p < 0.01). A sensitivity of 77% and specificity of 100% were calculated when using Army age adjusted BMI thresholds. The overall accuracy in determining if a Soldier met Army BMI standards and were within the maximum allowable BF or exceeded BMI standards and were over the maximum allowable BF was 83%. Using adjusted BMI thresholds in populations where physical fitness and training are requirements of the job provides better accuracy in identifying those who are overweight or obese due to high BF.

[The fasting calcium/creatinine ratio in patients with calcium stones and the relation with hypercalciuria and phosphocalcium metabolism].

PubMed

Arrabal-Polo, Miguel Ángel; del Carmen Cano-García, María; Arrabal-Martín, Miguel

2016-04-01

To determine the importance of fasting calcium/creatinine ratio in patients with calcium stones and its relation with hypercalciuria and phospho-calcium metabolism. Cross-sectional study including 143 patients divided into two groups according to fasting calcium/creatinine. Group 1: 66 patients (calcium/ creatinine<0.11); Group 2: 77 patients (calcium/ creatinine>0.11). A comparative study is performed between groups including phospho-calcium metabolism parameters and excretion of urinary lithogenic markers. Linear correlation studying calciuria and fasting calcium/ creatinine was performed. SPSS 17.0 statistical analysis software was used, considering p≤0.05. It is noteworthy that group 2 had increased 24 h urine calcium excretion in comparison to group 1 (229.3 vs 158.1; p=0.0001) and calcium/citrate (0.47 vs 0.34; p=0.001). There is a positive and significant correlation between calcium levels in 24 h urine and fasting calcium/creatinine (R=0.455; p=0.0001) and a cutoff is set at 0.127 (sensitivity 72%, specificity 66%) to determine hypercalciuria (>260 mg in 24 h). Increased fasting calcium/creatinine determines increased 24 hours calcium excretion, although the sensitivity and specificity to determine hypercalciuria is not high.

Highly sensitive detection of cancer cells using femtosecond dual-wavelength near-IR two-photon imaging.

PubMed

Starkey, Jean R; Makarov, Nikolay S; Drobizhev, Mikhail; Rebane, Aleksander

2012-07-01

We describe novel imaging protocols that allow detection of small cancer cell colonies deep inside tissue phantoms with high sensitivity and specificity. We compare fluorescence excited in Styryl-9M molecules by femtosecond pulses at near IR wavelengths, where Styryl-9M shows the largest dependence of the two-photon absorption (2PA) cross section on the local environment. We show that by calculating the normalized ratio of the two-photon excited fluorescence (2PEF) intensity at 1200 nm and 1100 nm excitation wavelengths we can achieve high sensitivity and specificity for determining the location of cancer cells surrounded by normal cells. The 2PEF results showed a positive correlation with the levels of MDR1 proteins expressed by the cells, and, for high MDR1 expressors, as few as ten cancer cells could be detected. Similar high sensitivity is also demonstrated for tumor colonies induced in mouse external ears. This technique could be useful in early cancer detection, and, perhaps, also in monitoring dormant cancer deposits.

Immune biosensors based on the SPR and TIRE: efficiency of their application for bacteria determination

NASA Astrophysics Data System (ADS)

Starodub, N. F.; Ogorodniichuk, J.; Lebedeva, T.; Shpylovyy, P.

2013-11-01

In this work we have designed high-specific biosensors for Salmonella typhimurium detection based on the surface plasmon resonance (SPR) and total internal reflection ellipsometry (TIRE). It has been demonstrated high selectivity and sensitivity of analysis. As a registering part for our experiments the Spreeta (USA) and "Plasmonotest" (Ukraine) with flowing cell have been applied among of SPR device. Previous researches confirmed an efficiency of SPR biosensors using for detecting of specific antigen-antibody interactions therefore this type of reactions with some previous preparations of surface binding layer was used as reactive part. It has been defined that in case with Spreeta sensitivity was on the level 103 - 107 cells/ml. Another biosensor based on the SPR has shown the sensitivity within 101 - 106 cells/ml. Maximal sensitivity was on the level of several cells in 10 ml (up to the fact that less than 5 cells) which has been obtained using the biosensor based on TIRE.

Evaluation of a rapid immunochromatographic ODK-0901 test for detection of pneumococcal antigen in middle ear fluids and nasopharyngeal secretions.

PubMed

Hotomi, Muneki; Togawa, Akihisa; Takei, Shin; Sugita, Gen; Sugita, Rinya; Kono, Masamitsu; Fujimaki, Yutaka; Kamide, Yosuke; Uchizono, Akihiro; Kanesada, Keiko; Sawada, Shoichi; Okitsu, Naohiro; Tanaka, Yumi; Saijo, Yoko; Yamanaka, Noboru

2012-01-01

Since the incidence of penicillin-resistant Streptococcus pneumoniae has been increasing at an astonishing rate throughout the world, the need for accurate and rapid identification of pneumococci has become increasingly important to determine the appropriate antimicrobial treatment. We have evaluated an immunochromatographic test (ODK-0901) that detects pneumococcal antigens using 264 middle ear fluids (MEFs) and 268 nasopharyngeal secretions (NPSs). A sample was defined to contain S. pneumoniae when optochin and bile sensitive alpha hemolytic streptococcal colonies were isolated by culture. The sensitivity and specificity of the ODK-0901 test were 81.4% and 80.5%, respectively, for MEFs from patients with acute otitis media (AOM). In addition, the sensitivity and specificity were 75.2% and 88.8%, respectively, for NPSs from patients with acute rhinosinusitis. The ODK-0901 test may provide a rapid and highly sensitive evaluation of the presence of S. pneumoniae and thus may be a promising method of identifying pneumococci in MEFs and NPSs.

Evaluation of a Rapid Immunochromatographic ODK-0901 Test for Detection of Pneumococcal Antigen in Middle Ear Fluids and Nasopharyngeal Secretions

PubMed Central

Hotomi, Muneki; Togawa, Akihisa; Takei, Shin; Sugita, Gen; Sugita, Rinya; Kono, Masamitsu; Fujimaki, Yutaka; Kamide, Yosuke; Uchizono, Akihiro; Kanesada, Keiko; Sawada, Shoichi; Okitsu, Naohiro; Tanaka, Yumi; Saijo, Yoko; Yamanaka, Noboru

2012-01-01

Since the incidence of penicillin-resistant Streptococcus pneumoniae has been increasing at an astonishing rate throughout the world, the need for accurate and rapid identification of pneumococci has become increasingly important to determine the appropriate antimicrobial treatment. We have evaluated an immunochromatographic test (ODK-0901) that detects pneumococcal antigens using 264 middle ear fluids (MEFs) and 268 nasopharyngeal secretions (NPSs). A sample was defined to contain S. pneumoniae when optochin and bile sensitive alpha hemolytic streptococcal colonies were isolated by culture. The sensitivity and specificity of the ODK-0901 test were 81.4% and 80.5%, respectively, for MEFs from patients with acute otitis media (AOM). In addition, the sensitivity and specificity were 75.2% and 88.8%, respectively, for NPSs from patients with acute rhinosinusitis. The ODK-0901 test may provide a rapid and highly sensitive evaluation of the presence of S. pneumoniae and thus may be a promising method of identifying pneumococci in MEFs and NPSs. PMID:22448257

The sensitivity of benzene cluster cation chemical ionization mass spectrometry to select biogenic terpenes

NASA Astrophysics Data System (ADS)

Lavi, Avi; Vermeuel, Michael P.; Novak, Gordon A.; Bertram, Timothy H.

2018-06-01

Benzene cluster cations are a sensitive and selective reagent ion for chemical ionization of select biogenic volatile organic compounds. We have previously reported the sensitivity of a field deployable chemical ionization time-of-flight mass spectrometer (CI-ToFMS), using benzene cluster cation ion chemistry, for detection of dimethyl sulfide, isoprene and α-pinene. Here, we present laboratory measurements of the sensitivity of the same instrument to a series of terpenes, including isoprene, α-pinene, β-pinene, D-limonene, ocimene, β-myrcene, farnesene, α-humulene, β-caryophyllene, and isolongifolene at atmospherically relevant mixing ratios (< 100 pptv). In addition, we determine the dependence of CI-ToFMS sensitivity on the reagent ion neutral delivery concentration and water vapor concentration. We show that isoprene is primarily detected as an adduct (C5H8 ṡ C6H6+) with a sensitivity ranging between 4 and 10 ncps ppt-1, which depends strongly on the reagent ion precursor concentration, de-clustering voltages, and specific humidity (SH). Monoterpenes are detected primarily as the molecular ion (C10H16+) with an average sensitivity, across the five measured compounds, of 14 ± 3 ncps ppt-1 for SH between 7 and 14 g kg-1, typical of the boreal forest during summer. Sesquiterpenes are detected primarily as the molecular ion (C15H24+) with an average sensitivity, across the four measured compounds, of 9.6 ± 2.3 ncps ppt-1, that is also independent of specific humidity. Comparable sensitivities across broad classes of terpenes (e.g., monoterpenes and sesquiterpenes), coupled to the limited dependence on specific humidity, suggest that benzene cluster cation CI-ToFMS is suitable for field studies of biosphere-atmosphere interactions.

Combination of methylated-DNA precipitation and methylation-sensitive restriction enzymes (COMPARE-MS) for the rapid, sensitive and quantitative detection of DNA methylation.

PubMed

Yegnasubramanian, Srinivasan; Lin, Xiaohui; Haffner, Michael C; DeMarzo, Angelo M; Nelson, William G

2006-02-09

Hypermethylation of CpG island (CGI) sequences is a nearly universal somatic genome alteration in cancer. Rapid and sensitive detection of DNA hypermethylation would aid in cancer diagnosis and risk stratification. We present a novel technique, called COMPARE-MS, that can rapidly and quantitatively detect CGI hypermethylation with high sensitivity and specificity in hundreds of samples simultaneously. To quantitate CGI hypermethylation, COMPARE-MS uses real-time PCR of DNA that was first digested by methylation-sensitive restriction enzymes and then precipitated by methyl-binding domain polypeptides immobilized on a magnetic solid matrix. We show that COMPARE-MS could detect five genome equivalents of methylated CGIs in a 1000- to 10,000-fold excess of unmethylated DNA. COMPARE-MS was used to rapidly quantitate hypermethylation at multiple CGIs in >155 prostate tissues, including benign and malignant prostate specimens, and prostate cell lines. This analysis showed that GSTP1, MDR1 and PTGS2 CGI hypermethylation as determined by COMPARE-MS could differentiate between malignant and benign prostate with sensitivities >95% and specificities approaching 100%. This novel technology could significantly improve our ability to detect CGI hypermethylation.

Comparison of the abbreviated minimal assessment of cognitive function in multiple sclerosis (aMACFIMS) and the brief international cognitive assessment for multiple sclerosis (BICAMS).

PubMed

Gromisch, Elizabeth S; Portnoy, Jeffrey G; Foley, Frederick W

2018-05-15

Cognitive impairment is a prevalent and often intrusive problem among persons with multiple sclerosis (PwMS). Valid and reliable assessments, including quick screening measures, are crucial. The Brief International Cognitive Assessment for MS (BICAMS) was developed for this reason. While it lends itself to use in locations where formal neuropsychological resources might be limited, it does not include measures of verbal fluency or executive functioning, domains assessed as part of the Minimal Assessment of Cognitive Function in MS (MACFIMS). Given previous evidence that shortened MACFIMS measures have strong criterion validity, this study aimed to determine which of these should be included in the abbreviated MACFIMS (aMACFIMS), and how the aMACFIMS compares to the BICAMS. One hundred forty-seven PwMS were included in the analyses. A stepwise logistic regression was used to determine the measures in the aMACFIMS. Receiver-operating-characteristic (ROC) curves assessed the classification accuracy, sensitivity, and specificity. The batteries' sensitivity, specificity, and predictive values were then compared. Compared to the BICAMS, the final aMACFIMS had higher specificity (87% versus 72%) and positive predictive value (86% versus 77%), but lower sensitivity (71% versus 81%). The aMACFIMS has several benefits, including reduced administration time and the addition of a verbal fluency/executive functioning measure. Copyright © 2018 Elsevier B.V. All rights reserved.

Serum Adenosine Deaminase (ADA) Activity: A Novel Screening Test to Differentiate HIV Monoinfection From HIV-HBV and HIV-HCV Coinfections.

PubMed

Abdi, Mohammad; Rahbari, Rizgar; Khatooni, Zahed; Naseri, Nima; Najafi, Adel; Khodadadi, Iraj

2016-05-01

CD4(+) cell count, the common HIV infection screening test, is costly and unable to differentiate HIV monoinfection from its concurrent infection with hepatitis B or C virus. We aimed to ascertain diagnostic value of serum adenosine deaminase (ADA) activity as a useful tool to differentiate HIV mono- and co-infection. Blood samples were collected from 30 HIV-HBV and 30 HIV-HCV coinfected patients, 33 HIV positive subjects, and 72 controls. CD4(+) cell count, serum total ADA (tADA), and ADA1, and ADA2 isoenzyme activities were determined and their sensitivity and specificity were computed. tADA and ADA2 activities were significantly higher and CD4(+) counts were markedly lower in all patients compared with controls. Strong inverse agreements between CD4(+) cell counts and both tADA and ADA2 activities were observed. Serum tADA and ADA1 activities showed the highest specificity and the highest sensitivity, respectively, for differentiating HIV monoinfection from HIV-HBV and HIV-HCV coinfections. We showed strong agreement and correlation between CD4(+) cell count and ADA enzyme activity. Based on high ADA sensitivity and specificity, it is concluded that determination of ADA activity might be a novel diagnostic tool to distinguish of HIV monoinfection from its coinfection with HBV or HCV. © 2015 Wiley Periodicals, Inc.

Determination of colonoscopy indication from administrative claims data.

PubMed

Ko, Cynthia W; Dominitz, Jason A; Neradilek, Moni; Polissar, Nayak; Green, Pam; Kreuter, William; Baldwin, Laura-Mae

2014-04-01

Colonoscopy outcomes, such as polyp detection or complication rates, may differ by procedure indication. To develop methods to classify colonoscopy indications from administrative data, facilitating study of colonoscopy quality and outcomes. We linked 14,844 colonoscopy reports from the Clinical Outcomes Research Initiative, a national repository of endoscopic reports, to the corresponding Medicare Carrier and Outpatient File claims. Colonoscopy indication was determined from the procedure reports. We developed algorithms using classification and regression trees and linear discriminant analysis (LDA) to classify colonoscopy indication. Predictor variables included ICD-9CM and CPT/HCPCS codes present on the colonoscopy claim or in the 12 months prior, patient demographics, and site of colonoscopy service. Algorithms were developed on a training set of 7515 procedures, then validated using a test set of 7329 procedures. Sensitivity was lowest for identifying average-risk screening colonoscopies, varying between 55% and 86% for the different algorithms, but specificity for this indication was consistently over 95%. Sensitivity for diagnostic colonoscopy varied between 77% and 89%, with specificity between 55% and 87%. Algorithms with classification and regression trees with 7 variables or LDA with 10 variables had similar overall accuracy, and generally lower accuracy than the algorithm using LDA with 30 variables. Algorithms using Medicare claims data have moderate sensitivity and specificity for colonoscopy indication, and will be useful for studying colonoscopy quality in this population. Further validation may be needed before use in alternative populations.

Spinal perimedullary vein enlargement sign: an added value for the differentiation between intradural-extramedullary and intramedullary tumors on magnetic resonance imaging.

PubMed

Gong, Tao; Liu, Yubo; Wang, Guangbin; Yang, Li; Chen, Weibo; Gao, Fei; Chen, Xin

2016-11-01

The purpose of this study was to determine the added value of the perimedullary spinal vein enlargement sign on magnetic resonance imaging (MRI) in distinguishing intradural-extramedullary tumors (IDEMTs) from intramedullary spinal tumors (IMTs). Two hundred and eight consecutive spinal intradural tumors with histopathologic confirmation (21 IMTs, 187 IDEMTs) were enrolled. Two readers blinded to the final pathological diagnosis and clinical data independently assessed the venous enlargement sign to determine the agreement between them and jointly distinguished IDEMTs from IMTs according to the common MRI findings. Sensitivity, specificity, and accuracy for the diagnosis of IDEMTs were calculated for the common MRI findings, vein enlargement sign, and a combination of both. Intraobserver agreement and interobserver agreement for both readers was excellent. The sensitivity, specificity, and accuracy of common MRI findings for differentiating IDEMTs from IMTs were 83.4, 95.2, and 89.3 %, respectively. Thirty-one IDEMTs were mistakenly diagnosed as IMTs, in which seven were cases with vein enlargement signs. By applying the vein enlargement sign to the common MRI findings, the specificity remained at 95.2 %, while the sensitivity improved to 89.3 % and the accuracy increased to 92.3 %. The spinal perimedullary vein enlargement sign is useful in assessing intradural tumors and to differentiate IDEMTs from IMTs.

Management of neonatal sepsis at Muhimbili National Hospital in Dar es Salaam: diagnostic accuracy of C-reactive protein and newborn scale of sepsis and antimicrobial resistance pattern of etiological bacteria.

PubMed

Mkony, Martha Franklin; Mizinduko, Mucho Michael; Massawe, Augustine; Matee, Mecky

2014-12-05

We determined the accuracy of Rubarth's newborn scale of sepsis and C- reactive protein in diagnosing neonatal sepsis and assessed antimicrobial susceptibility pattern of etiological bacteria. This cross sectional study was conducted at Muhimbili National Hospital in Dar es Salaam, Tanzania between July 2012 and March 2013. Neonates suspected to have sepsis underwent physical examination using Rubarth's newborn scale of sepsis (RNSOS). Blood was taken for culture and antimicrobial sensitivity testing, full blood picture and C - reactive protein (CRP) performed 12 hours apart. The efficacy of RNSOS and serial CRP was assessed by calculating sensitivity, specificity, negative and positive predictive values, receiver operating characteristics (ROC) analysis as well as likelihood ratios (LHR) with blood culture result used as a gold standard. Out of 208 blood samples, 19.2% had a positive blood culture. Single CRP had sensitivity and specificity of 87.5% and 70.9% respectively, while RNSOS had sensitivity of 65% and specificity of 79.7%. Serial CRP had sensitivity of 69.0% and specificity of 92.9%. Combination of CRP and RNSOS increased sensitivity to 95.6% and specificity of 56.4%. Combination of two CRP and RNSOS decreased sensitivity to 89.1% but increased specificity to 74%. ROC for CRP was 0.86; and for RNSOS was 0.81. For CRP the LHR for positive test was 3 while for negative test was 0.18, while for RNSOS the corresponding values were 3.24 and for negative test was 0.43. Isolated bacteria were Klebsiella spp 14 (35%), Escherichia coli 12 (22.5%), Coagulase negative staphlococci 9 (30%), Staphylococcus aureus 4 (10%), and Pseudomonas spp 1 (2.5%). The overall resistance to the WHO recommended first line antibiotics was 100%, 92% and 42% for cloxacillin, ampicillin and gentamicin, respectively. For the second line drugs resistance was 45%, 40%, and 7% for ceftriaxone, vancomycin and amikacin respectively. Single CRP in combination with RNSOS can be used for rapid identification of neonates with sepsis due to high sensitivity (95.6%) but cannot exclude those without sepsis due to low specificity (56.4%). Serial CRP done 12hrs apart can be used to exclude non-cases. This study demonstrated very high levels of resistance to the first-line antibiotics.

Sensitivity and specificity of subacute computerized neurocognitive testing and symptom evaluation in predicting outcomes after sports-related concussion.

PubMed

Lau, Brian C; Collins, Michael W; Lovell, Mark R

2011-06-01

Concussions affect an estimated 136 000 high school athletes yearly. Computerized neurocognitive testing has been shown to be appropriately sensitive and specific in diagnosing concussions, but no studies have assessed its utility to predict length of recovery. Determining prognosis during subacute recovery after sports concussion will help clinicians more confidently address return-to-play and academic decisions. To quantify the prognostic ability of computerized neurocognitive testing in combination with symptoms during the subacute recovery phase from sports-related concussion. Cohort study (prognosis); Level of evidence, 2. In sum, 108 male high school football athletes completed a computer-based neurocognitive test battery within 2.23 days of injury and were followed until returned to play as set by international guidelines. Athletes were grouped into protracted recovery (>14 days; n = 50) or short-recovery (≤14 days; n = 58). Separate discriminant function analyses were performed using total symptom score on Post-Concussion Symptom Scale, symptom clusters (migraine, cognitive, sleep, neuropsychiatric), and Immediate Postconcussion Assessment and Cognitive Testing neurocognitive scores (verbal memory, visual memory, reaction time, processing speed). Multiple discriminant function analyses revealed that the combination of 4 symptom clusters and 4 neurocognitive composite scores had the highest sensitivity (65.22%), specificity (80.36%), positive predictive value (73.17%), and negative predictive value (73.80%) in predicting protracted recovery. Discriminant function analyses of total symptoms on the Post-Concussion Symptom Scale alone had a sensitivity of 40.81%; specificity, 79.31%; positive predictive value, 62.50%; and negative predictive value, 61.33%. The 4 symptom clusters alone discriminant function analyses had a sensitivity of 46.94%; specificity, 77.20%; positive predictive value, 63.90%; and negative predictive value, 62.86%. Discriminant function analyses of the 4 computerized neurocognitive scores alone had a sensitivity of 53.20%; specificity, 75.44%; positive predictive value, 64.10%; and negative predictive value, 66.15%. The use of computerized neurocognitive testing in conjunction with symptom clusters results improves sensitivity, specificity, positive predictive value, and negative predictive value of predicting protracted recovery compared with each used alone. There is also a net increase in sensitivity of 24.41% when using neurocognitive testing and symptom clusters together compared with using total symptoms on Post-Concussion Symptom Scale alone.

Preformed Frequencies of Cytomegalovirus (CMV)–Specific Memory T and B Cells Identify Protected CMV-Sensitized Individuals Among Seronegative Kidney Transplant Recipients

PubMed Central

Lúcia, Marc; Crespo, Elena; Melilli, Edoardo; Cruzado, Josep M.; Luque, Sergi; Llaudó, Inés; Niubó, Jordi; Torras, Joan; Fernandez, Núria; Grinyó, Josep M.; Bestard, Oriol

2014-01-01

Background. Cytomegalovirus (CMV) infection remains a major complication after kidney transplantation. Baseline CMV risk is typically determined by the serological presence of preformed CMV-specific immunoglobulin (Ig) G antibodies, even though T-cell responses to major viral antigens are crucial when controlling viral replication. Some IgG-seronegative patients who receive an IgG-seropositive allograft do not develop CMV infection despite not receiving prophylaxis. We hypothesized that a more precise evaluation of pretransplant CMV-specific immune-sensitization using the B and T-cell enzyme-linked immunospot assays may identify CMV-sensitized individuals more accurately, regardless of serological evidence of CMV-specific IgG titers. Methods. We compared the presence of preformed CMV-specific memory B and T cells in kidney transplant recipients between 43 CMV IgG–seronegative (sR−) and 86 CMV IgG–seropositive (sR+) patients. Clinical outcome was evaluated in both groups. Results. All sR+ patients showed a wide range of CMV-specific memory T- and B-cell responses. High memory T- and B-cell frequencies were also clearly detected in 30% of sR− patients, and those with high CMV-specific T-cell frequencies had a significantly lower incidence of late CMV infection after prophylactic therapy. Receiver operating characteristic curve analysis for predicting CMV viremia and disease showed a high area under the receiver operating characteristic curve (>0.8), which translated into a high sensitivity and negative predictive value of the test. Conclusions. Assessment of CMV-specific memory T- and B-cell responses before kidney transplantation among sR− recipients may help identify immunized individuals more precisely, being ultimately at lower risk for CMV infection. PMID:25048845

Aptamer-fluorescent silica nanoparticles bioconjugates based dual-color flow cytometry for specific detection of Staphylococcus aureus.

PubMed

He, Xiaoxiao; Li, Yuhong; He, Dinggen; Wang, Kemin; Shangguan, Jingfang; Shi, Hui

2014-07-01

This paper describes a sensitive and specific determination strategy for Staphylococcus aureus (S. aureus) detection using aptamer recognition and fluorescent silica nanoparticles (FSiNPs) label based dual-color flow cytometry assay (Aptamer/FSiNPs-DCFCM). In the protocol, an aptamer, having high affinity to S. aureus, was first covalently immobilized onto chloropropyl functionalized FSiNPs through a click chemistry approach to generate aptamer-nanoparticles bioconjugates (Aptamer/FSiNPs). Next, S. aureus was incubated with Aptamer/FSiNPs, and then stained with SYBR Green I (a special staining material for the duplex DNA). Upon target binding and nucleic acid staining with SYBR Green I, the S. aureus was determined using two-color flow cytometry. The method took advantage of the specificity of aptamer, signal amplification of FSiNPs label and decreased false positives of two-color flow cytometry assay. It was demonstrated that these Aptamer/FSiNPs could efficiently recognize and fluorescently label target S. aureus. Through multiparameter determination with flow cytometry, this assay allowed for detection of as low as 1.5 x 10(2) and 7.6 x 10(2) cells mL(-1) S. aureus in buffer and spiked milk, respectively, with higher sensitivity than the Aptamer/FITC based flow cytometry.

Non-parametric early seizure detection in an animal model of temporal lobe epilepsy

NASA Astrophysics Data System (ADS)

Talathi, Sachin S.; Hwang, Dong-Uk; Spano, Mark L.; Simonotto, Jennifer; Furman, Michael D.; Myers, Stephen M.; Winters, Jason T.; Ditto, William L.; Carney, Paul R.

2008-03-01

The performance of five non-parametric, univariate seizure detection schemes (embedding delay, Hurst scale, wavelet scale, nonlinear autocorrelation and variance energy) were evaluated as a function of the sampling rate of EEG recordings, the electrode types used for EEG acquisition, and the spatial location of the EEG electrodes in order to determine the applicability of the measures in real-time closed-loop seizure intervention. The criteria chosen for evaluating the performance were high statistical robustness (as determined through the sensitivity and the specificity of a given measure in detecting a seizure) and the lag in seizure detection with respect to the seizure onset time (as determined by visual inspection of the EEG signal by a trained epileptologist). An optimality index was designed to evaluate the overall performance of each measure. For the EEG data recorded with microwire electrode array at a sampling rate of 12 kHz, the wavelet scale measure exhibited better overall performance in terms of its ability to detect a seizure with high optimality index value and high statistics in terms of sensitivity and specificity.

Genomic testing to determine drug response: measuring preferences of the public and patients using Discrete Choice Experiment (DCE)

PubMed Central

2013-01-01

Background The extent to which a genomic test will be used in practice is affected by factors such as ability of the test to correctly predict response to treatment (i.e. sensitivity and specificity of the test), invasiveness of the testing procedure, test cost, and the probability and severity of side effects associated with treatment. Methods Using discrete choice experimentation (DCE), we elicited preferences of the public (Sample 1, N = 533 and Sample 2, N = 525) and cancer patients (Sample 3, N = 38) for different attributes of a hypothetical genomic test for guiding cancer treatment. Samples 1 and 3 considered the test/treatment in the context of an aggressive curable cancer (scenario A) while the scenario for sample 2 was based on a non-aggressive incurable cancer (scenario B). Results In aggressive curable cancer (scenario A), everything else being equal, the odds ratio (OR) of choosing a test with 95% sensitivity was 1.41 (versus a test with 50% sensitivity) and willingness to pay (WTP) was $1331, on average, for this amount of improvement in test sensitivity. In this scenario, the OR of choosing a test with 95% specificity was 1.24 times that of a test with 50% specificity (WTP = $827). In non-aggressive incurable cancer (scenario B), the OR of choosing a test with 95% sensitivity was 1.65 (WTP = $1344), and the OR of choosing a test with 95% specificity was 1.50 (WTP = $1080). Reducing severity of treatment side effects from severe to mild was associated with large ORs in both scenarios (OR = 2.10 and 2.24 in scenario A and B, respectively). In contrast, patients had a very large preference for 95% sensitivity of the test (OR = 5.23). Conclusion The type and prognosis of cancer affected preferences for genomically-guided treatment. In aggressive curable cancer, individuals emphasized more on the sensitivity rather than the specificity of the test. In contrast, for a non-aggressive incurable cancer, individuals put similar emphasis on sensitivity and specificity of the test. While the public expressed strong preference toward lowering severity of side effects, improving sensitivity of the test had by far the largest influence on patients’ decision to use genomic testing. PMID:24176050

Performance of the G4 Xpert® MTB/RIF assay for the detection of Mycobacterium tuberculosis and rifampin resistance: a retrospective case-control study of analytical and clinical samples from high- and low-tuberculosis prevalence settings.

PubMed

Dharan, Nila J; Blakemore, Robert; Sloutsky, Alex; Kaur, Devinder; Alexander, Richard C; Ghajar, Minoo; Musser, Kimberlee A; Escuyer, Vincent E; Rowlinson, Marie-Claire; Crowe, Susanne; Laniado-Laborin, Rafael; Valli, Eloise; Nabeta, Pamela; Johnson, Pamela; Alland, David

2016-12-20

The Xpert ® MTB/RIF (Xpert) assay is a rapid PCR-based assay for the detection of Mycobacterium tuberculosis complex DNA (MTBc) and mutations associated with rifampin resistance (RIF). An updated version introduced in 2011, the G4 Xpert, included modifications to probe B and updated analytic software. An analytical study was performed to assess Xpert detection of mutations associated with rifampin resistance in rifampin-susceptible and -resistant isolates. A clinical study was performed in which specimens from US and non-US persons suspected of tuberculosis (TB) were tested to determine Xpert performance characteristics. All specimens underwent smear microscopy, mycobacterial culture, conventional drug-susceptibility testing and Xpert testing; DNA from isolates with discordant rifampin resistance results was sequenced. Among 191 laboratory-prepared isolates in the analytical study, Xpert sensitivity for detection of rifampin resistance associated mutations was 97.7% and specificity was 90.8%, which increased to 99.0% after DNA sequencing analysis of the discordant samples. Of the 1,096 subjects in the four clinical studies, 49% were from the US. Overall, Xpert detected MTBc in 439 of 468 culture-positive specimens for a sensitivity of 93.8% (95% confidence interval [CI]: 91.2%-95.7%) and did not detect MTBc in 620 of 628 culture-negative specimens for a specificity of 98.7% (95% CI: 97.5%-99.4%). Sensitivity was 99.7% among smear-positive cases, and 76.1% among smear-negative cases. Non-determinate MTBc detection and false-positive RIF resistance results were low (1.2 and 0.9%, respectively). The updated Xpert assay retained the high sensitivity and specificity of the previous assay versions and demonstrated low rates of non-determinate and RIF resistance false positive results.

Competitive Enzyme Immunoassay for Diagnosis of Human Brucellosis

PubMed Central

Lucero, Nidia E.; Foglia, Luis; Ayala, Sandra M.; Gall, David; Nielsen, Klaus

1999-01-01

The methods commonly used for human brucellosis serological testing are agglutination tests and the complement fixation test (CFT). Among the newer serological tests, primary binding assays were developed to improve sensitivity and specificity. The competitive enzyme immunoassay (CELISA) for the detection of serum antibody to Brucella is a multispecies assay which appears to be capable of differentiating vaccinal and cross-reacting antibodies from antibodies elicited by field infection in cattle. The competing monoclonal antibody used in this assay is specific for a common epitope of smooth lipopolysaccharide (S-LPS). In this study, we compared the CELISA to the classical tests for the diagnosis of human brucellosis. The CELISA cutoff value was determined to calculate its diagnostic specificity and sensitivity. A survey was performed with 911 sera. Of the sera, 341 were from an asymptomatic population that tested negative with conventional serological tests (screening and confirmatory). Based on these samples, the CELISA specificities were determined to be 99.7 and 100% with cutoff values of 28 and 30% inhibition (%I), respectively. In a further study with 393 additional sera from an asymptomatic population found negative by the conventional screening tests, the CELISA specificities were calculated to be 96.5 and 98.8% with cutoff values of 28 and 30%I. The CELISA sensitivities were determined to be 98.3 and 94.8% with cutoff values of 28 and 30%I, respectively, for sera from 116 individuals found positive by the classical tests. For the 51 culture-positive patients, CELISA was positive for 100%, the CFT was positive for 92%, and the standard tube agglutination test (TAT) was positive for 100%. The CELISA specificity was 100% for 31 sera from patients found negative by conventional serological tests but with brucellosis-like symptoms. The CELISA is fairly rapid to perform, somewhat faster than TAT, and cross-reacts less with other antigens (or antibodies) than the conventional tests. Further, the CELISA is simpler to perform that the CFT and may readily be standardized by the use of purified S-LPS antigen and monoclonal antibody for competition. PMID:10488186

Handgrip Strength Cutoff Points to Identify Mobility Limitation in Community-dwelling Older People and Associated Factors.

PubMed

Vasconcelos, K S de Souza; Dias, J M Domingues; Bastone, A de Carvalho; Vieira, R Alvarenga; Andrade, A C de Souza; Perracini, M Rodrigues; Guerra, R Oliveira; Dias, R Corrêa

2016-03-01

Sarcopenia is defined as a progressive and generalized loss of skeletal muscle mass and strength. The specific threshold of muscle weakness that leads to mobility limitations has not been identified. To determine the best cutoff point of handgrip strength for identifying mobility limitation and to investigate the factors associated with muscle weakness and mobility limitation in community-dwelling older people. Transversal study. Cities of Belo Horizonte, Barueri and Santa Cruz in Brazil. 1374 community-dwelling older people from the Frailty study in Brazilian older people (FIBRA Study). Outcomes included muscle weakness determined according to gender-specific handgrip strength cutoff points generated by Receiver Operating Characteristic curves, mobility limitation defined as a gait speed ≤ 0.8 m/s; and a combination of both muscle weakness and mobility limitation. Associated factors included socio-demographic variables, lifestyle, anthropometrics, health conditions, use of health services and disability. The cutoff points of handgrip strength with the best balancing between sensitivity and specificity for mobility limitation were 25.8 kgf for men (sensitivity 69%, specificity 73%) and 17.4 kgf (sensitivity 60%, specificity 66%) for women. Age and disability in instrumental activities of daily living were associated with all outcomes. Women had greater odds of mobility limitation than men. Physical inactivity, body fat, diabetes, depression, sleeping disturbances, number of medications and occurrence of falls remained as significant associated factors in the final model. Handgrip strength can be a useful tool to identify mobility limitation in clinical practice. Interventions to prevent or minimize impacts of sarcopenia should stimulate physical activity and improvement of body composition in addition to the management of chronic diseases and disabilities.

Ethnic dependent differences in diagnostic accuracy of glycated hemoglobin (HbA1c) in Canadian adults.

PubMed

Booth, Ronald A; Jiang, Ying; Morrison, Howard; Orpana, Heather; Rogers Van Katwyk, Susan; Lemieux, Chantal

2018-02-01

Previous studies have shown varying sensitivity and specificity of hemoglobin A1c (HbA1c) to identify diabetes and prediabetes, compared to 2-h oral glucose tolerance testing (OGTT) and fasting plasma glucose (FPG), in different ethnic groups. Within the Canadian population, the ability of HbA1c to identify prediabetes and diabetes in First Nations, Métis and Inuit, East and South Asian ethnic groups has yet to be determined. We collected demographic, lifestyle information, biochemical results of glycemic status (FPG, OGTT, and HbA1c) from an ethnically diverse Canadian population sample, which included a purposeful sampling of First Nations, Métis, Inuit, South Asian and East Asian participants. Sensitivity and specificity using Canadian Diabetes Association (CDA) recommended cut-points varied between ethnic groups, with greater variability for identification of prediabetes than diabetes. Dysglycemia (prediabetes and diabetes) was identified with a sensitivity and specificity ranging from 47.1% to 87.5%, respectively in Caucasians to 24.1% and 88.8% in Inuit. Optimal HbA1c ethnic-specific cut-points for dysglycemia and diabetes were determined by receiver operating characteristic (ROC) curve analysis. Our sample showed broad differences in the ability of HbA1c to identify dysglycemia or diabetes in different ethnic groups. Optimal cut-points for dysglycemia or diabetes in all ethnic groups were substantially lower than CDA recommendations. Utilization of HbA1c as the sole biochemical diagnostic marker may produce varying degrees of false negative results depending on the ethnicity of screened individuals. Further research is necessary to identify and validate optimal ethnic specific cut-points used for diabetic screening in the Canadian population. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Characterization of Neutralization Determinants on Epizootic Hemorrhagic Disease Virus

USDA-ARS?s Scientific Manuscript database

The control of Rift Valley Fever (RVF) outbreaks requires sensitive and specific diagnostics, effective vector monitoring and management, and vaccination of humans and animals. The Arthropod-Borne Animal Diseases Research Laboratory has a multidisciplinary scientific team comprised of microbiologist...

Cervical VEMP threshold response curve in the identification of Ménière's disease.

PubMed

Zhu, Yi; McPherson, James; Beatty, Charles; Driscoll, Colin; Neff, Brian; Eggers, Scott; Shepard, Neil T

2014-03-01

To investigate the sensitivity/specificity of a shift upward in the most sensitive frequency of the cervical vestibular evoked myogenic potential (cVEMP) threshold-response curve in the identification of Ménière's disease (MD). A secondary purpose was to investigate the clinical characteristics that had an impact on the sensitivity/specificity and to adjust the criteria for a positive shift upward in the cVEMP curve to maximize performance of the test. A retrospective review of patients diagnosed with MD and those without MD. Two hundred ninety-four patients met the inclusion criteria of symptom complaints of spontaneous events of vertigo and a full vestibular and balance evaluation with cVEMP threshold-response curve testing. Two hundred six of these patients were diagnosed with MD, and 88 patients were determined to be non-MD. Review of the patients' medical records was used to extract data on the results of the cVEMP curve, age, gender, duration from time of onset of spontaneous events, pure tone average from hearing test, and water caloric asymmetry. Student's t-test, χ² test, receiver operating characteristic (ROC) curve with area under the curve (AUC), Pearson correlation coefficient, and sensitivity/specificity from 2 × 2 tables were all used in the analysis. Basic sensitivity/specificity for a shift upward in the most sensitive frequency to 1000 Hz in the cVEMP threshold-response curve was 0.47/0.64 respectively. Clinical characteristics that were found to have a significant impact on the sensitivity/specificity were age equal to or above 60 yr and a caloric asymmetry ≥25%. Various combinations of age and caloric with the requirement of a shift upward in the cVEMP curve most sensitive frequency to 1000 Hz resulted in significant but modest improvements in sensitivity/specificity. However, the overall performance was not shown acceptable for routine clinical use with maximum sensitivity at 0.73. Therefore, placing an emphasis on specificity over sensitivity results showed specificity of 0.95 for those under 60 yr and 0.90 for those 60 yr of age or older with sensitivity at 0.20, but only in the context of a ≥25% caloric asymmetry. We recommend the use of the shift upward to 1000 Hz with a caloric asymmetry as the clinical protocol to maximize the use of the cVEMP threshold-response curve for assistance in the identification of MD, in the context of a ≥25% caloric asymmetry. This implies that if the test is negative no interpretation of identification of MD can be made. If the test is positive the results can be used to increase the argument for MD since the probability of the result being a false positive is only 5-10%. American Academy of Audiology.

Mission Analysis for High Specific Impulse Deep Space Exploration

NASA Technical Reports Server (NTRS)

Adams, Robert B.; Polsgrove, Tara; Brady, Hugh J. (Technical Monitor)

2002-01-01

This paper describes trajectory calculations for high specific impulse engines. Specific impulses on the order of 10,000 to 100,000 sec are predicted in a variety of fusion powered propulsion systems. This paper and its companion paper seek to build on analyses in the literature to yield an analytical routine for determining time of flight and payload fraction to a predetermined destination. The companion paper will compare the results of this analysis to the trajectories determined by several trajectory codes. The major parameters that affect time of flight and payload fraction will be identified and their sensitivities quantified. A review of existing fusion propulsion concepts and their capabilities will also be tabulated.

Multiplex Identification of Gram-Positive Bacteria and Resistance Determinants Directly from Positive Blood Culture Broths: Evaluation of an Automated Microarray-Based Nucleic Acid Test

PubMed Central

Buchan, Blake W.; Ginocchio, Christine C.; Manii, Ryhana; Cavagnolo, Robert; Pancholi, Preeti; Swyers, Lettie; Thomson, Richard B.; Anderson, Christopher; Kaul, Karen; Ledeboer, Nathan A.

2013-01-01

Background A multicenter study was conducted to evaluate the diagnostic accuracy (sensitivity and specificity) of the Verigene Gram-Positive Blood Culture Test (BC-GP) test to identify 12 Gram-positive bacterial gene targets and three genetic resistance determinants directly from positive blood culture broths containing Gram-positive bacteria. Methods and Findings 1,252 blood cultures containing Gram-positive bacteria were prospectively collected and tested at five clinical centers between April, 2011 and January, 2012. An additional 387 contrived blood cultures containing uncommon targets (e.g., Listeria spp., S. lugdunensis, vanB-positive Enterococci) were included to fully evaluate the performance of the BC-GP test. Sensitivity and specificity for the 12 specific genus or species targets identified by the BC-GP test ranged from 92.6%–100% and 95.4%–100%, respectively. Identification of the mecA gene in 599 cultures containing S. aureus or S. epidermidis was 98.6% sensitive and 94.3% specific compared to cefoxitin disk method. Identification of the vanA gene in 81 cultures containing Enterococcus faecium or E. faecalis was 100% sensitive and specific. Approximately 7.5% (87/1,157) of single-organism cultures contained Gram-positive bacteria not present on the BC-GP test panel. In 95 cultures containing multiple organisms the BC-GP test was in 71.6% (68/95) agreement with culture results. Retrospective analysis of 107 separate blood cultures demonstrated that identification of methicillin resistant S. aureus and vancomycin resistant Enterococcus spp. was completed an average of 41.8 to 42.4 h earlier using the BC-GP test compared to routine culture methods. The BC-GP test was unable to assign mecA to a specific organism in cultures containing more than one Staphylococcus isolate and does not identify common blood culture contaminants such as Micrococcus, Corynebacterium, and Bacillus. Conclusions The BC-GP test is a multiplex test capable of detecting most leading causes of Gram-positive bacterial blood stream infections as well as genetic markers of methicillin and vancomycin resistance directly from positive blood cultures. Please see later in the article for the Editors' Summary PMID:23843749

Performance characteristics of broth-only cultures after revision total joint arthroplasty.

PubMed

Smith, Eric B; Cai, Jenny; Wynne, Rachael; Maltenfort, Mitchell; Good, Robert P

2014-11-01

Surgeons frequently obtain intraoperative cultures at the time of revision total joint arthroplasty. The use of broth or liquid medium before applying the sample to the agar medium may be associated with contamination and false-positive cultures; however, the degree to which this is the case is not known. We (1) calculated the performance characteristics of broth-only cultures (sensitivity, specificity, positive predictive value, and negative predictive value) and (2) characterized the organisms identified in broth to determine whether a specific organism showed increased proclivity for true-positive periprosthetic joint infection (PJI). A single-institution retrospective chart review was performed on 257 revision total joint arthroplasties from 2009 through 2010. One hundred ninety (74%) had cultures for review. All culture results, as well as treatment, if any, were documented and patients were followed for a minimum of 1 year for evidence of PJI. Cultures were measured as either positive from the broth only or broth negative. The true diagnosis of infection was determined by the Musculoskeletal Infection Society criteria during the preoperative workup or postoperatively at 1 year for purposes of calculating the performance characteristics of the broth-only culture. The sensitivity, specificity, positive predictive value, and negative predictive value were 19%, 88%, 13%, and 92%, respectively. The most common organism identified was coagulase-negative Staphylococcus (16 of 24 cases, 67%). Coagulase-negative Staphylococcus was present in all three true-positive cases; however, it was also found in 13 of the false-positive cases. The broth-only positive cultures showed poor sensitivity and positive predictive value but good specificity and negative predictive value. The good specificity indicates that it can help to rule in the presence of PJI; however, the poor sensitivity makes broth-only culture an unreliable screening test. We recommend that broth-only culture results be carefully scrutinized and decisions on the diagnosis and treatment of infection should be based specifically on the Musculoskeletal Infection Society criteria. Level IV, diagnostic study. See Instructions for Authors for a complete description of levels of evidence.

Highly sensitive determination of diclofenac based on resin beads and a novel polyclonal antibody by using flow injection chemiluminescence competitive immunoassay

NASA Astrophysics Data System (ADS)

Shi, Jing; Xu, Mingxia; Tang, Qinghui; Zhao, Kang; Deng, Anping; Li, Jianguo

2018-02-01

A novel flow injection chemiluminescence immunoassay for simple, sensitive and low-cost detection of diclofenac was established based on specific binding of antigen and antibody. Carboxylic resin beads used as solid phase carrier materials provided good biocompatibility and large surface-to-volume ratio for modifying more coating antigen. There was a competitive process between the diclofenac in solution and the immobilized coating antigen to react with the limited binding sites of the polyclonal antibody to form the immunocomplex. The second antibody labelled with horseradish peroxidase was introduced into the immunosensor and trapped by captured polyclonal antibody against diclofenac, which could effectively amplify chemiluminescence signals of luminol-PIP-H2O2. Under optimal conditions, the diclofenac could be detected quantitatively. The chemiluminescence intensity decreased linearly with the logarithm of the diclofenac concentration in the range of 0.1-100 ng mL- 1 with a detection limit of 0.05 ng mL- 1 at a signal-to-noise ratio of 3. The immunosensor exhibited high sensitivity, specificity and acceptable stability. This easy-operated and cost-effective analytical method could be valuable for the diclofenac determination in real water samples.

Accuracy of a point-of-care ELISA test kit for predicting the presence of protective canine parvovirus and canine distemper virus antibody concentrations in dogs.

PubMed

Litster, A L; Pressler, B; Volpe, A; Dubovi, E

2012-08-01

Canine parvovirus (CPV) and canine distemper virus (CDV) are highly infectious and often fatal diseases with worldwide distributions, and are important population management considerations in animal shelters. A point-of-care ELISA test kit is available to detect serum antibodies to CPV and CDV, and presumptively to predict protective status. The aim of this study was to determine the diagnostic accuracy of the test compared to CPV hemagglutination inhibition titers and CDV serum neutralization titers determined by a reference laboratory, using sera collected from dogs housed at animal shelters. The ELISA test was used under both field and laboratory conditions and duplicate specimens were processed using an extra wash step. The test kit yielded accurate results (CPV: sensitivity 92.3%, specificity 93.5%; CDV: sensitivity 75.7%, specificity 91.8%) under field conditions. CDV sensitivity was improved by performing the test under laboratory conditions and using an optical density (OD) meter (laboratory performed 94.0%; OD 88.1%). Point-of-care ELISA testing for serum CPV and CDV antibody titers was demonstrated to be a useful tool for determining antibody status when making decisions regarding the need for CPV and/or CDV vaccination and also in animal shelters for population management. Copyright © 2012 Elsevier Ltd. All rights reserved.

The use of hippocampal volumetric measurements to improve diagnostic accuracy in pediatric patients with mesial temporal sclerosis.

PubMed

Guzmán Pérez-Carrillo, Gloria J; Owen, Christopher; Schwetye, Katherine E; McFarlane, Spencer; Vellimana, Ananth K; Mar, Soe; Miller-Thomas, Michelle M; Shimony, Joshua S; Smyth, Matthew D; Benzinger, Tammie L S

2017-06-01

OBJECTIVE Many patients with medically intractable epilepsy have mesial temporal sclerosis (MTS), which significantly affects their quality of life. The surgical excision of MTS lesions can result in marked improvement or even complete resolution of the epileptic episodes. Reliable radiological diagnosis of MTS is a clinical challenge. The purpose of this study was to evaluate the utility of volumetric mapping of the hippocampi for the identification of MTS in a case-controlled series of pediatric patients who underwent resection for medically refractory epilepsy, using pathology as a gold standard. METHODS A cohort of 57 pediatric patients who underwent resection for medically intractable epilepsy between 2005 and 2015 was evaluated. On pathological investigation, this group included 24 patients with MTS and 33 patients with non-MTS findings. Retrospective quantitative volumetric measurements of the hippocampi were acquired for 37 of these 57 patients. Two neuroradiologists with more than 10 years of experience who were blinded to the patients' MTS status performed the retrospective review of MR images. To produce the volumetric data, MR scans were parcellated and segmented using the FreeSurfer software suite. Hippocampal regions of interest were compared against an age-weighted local regression curve generated with data from the pediatric normal cohort. Standard deviations and percentiles of specific subjects were calculated. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were determined for the original clinical read and the expert readers. Receiver operating characteristic curves were generated for the methods of classification to compare results from the readers with the authors' results, and an optimal threshold was determined. From that threshold the sensitivity, specificity, PPV, and NPV were calculated for the volumetric analysis. RESULTS With the use of quantitative volumetry, a sensitivity of 72%, a specificity of 95%, a PPV of 93%, an NPV of 78%, and an area under the curve of 0.84 were obtained using a percentage difference of normalized hippocampal volume. The resulting specificity (95%) and PPV (93%) are superior to the original clinical read and to Reader A and Reader B's findings (range for specificity 74%-86% and for PPV 64%-71%). The sensitivity (72%) and NPV (78%) are comparable to Reader A's findings (73% and 81%, respectively) and are better than those of the original clinical read and of Reader B (sensitivity 45% and 63% and NPV 71% and 70%, respectively). CONCLUSIONS Volumetric measurement of the hippocampi outperforms expert readers in specificity and PPV, and it demonstrates comparable to superior sensitivity and NPV. Volumetric measurements can complement anatomical imaging for the identification of MTS, much like a computer-aided detection tool would. The implementation of this approach in the daily clinical workflow could significantly improve diagnostic accuracy.

Voice Handicap Index and Interpretation of the Cutoff Points Using Receiver Operating Characteristic Curve as Screening for Young Adult Female Smokers.

PubMed

Tafiadis, Dionysios; Kosma, Evangelia I; Chronopoulos, Spyridon K; Papadopoulos, Aggelos; Drosos, Konstantinos; Siafaka, Vassiliki; Toki, Eugenia I; Ziavra, Nausica

2018-01-01

The relationship between smoking and alterations of the vocal tract and larynx is well known. This pathology leads to the degradation of voice performance in daily living. Multiple assessment methods of vocal tract and larynx have been developed, and in recent years they were enriched with self-reported questionnaires such as Voice Handicap Index (VHI). This study determined the cutoff points of VHI's total score and its three domains for young female smokers in Greece. These estimated cutoff points could be used by voice specialists as an indicator for further clinical evaluation (foreseeing a potential risk of developing a vocal symptom because of smoking habits). A sample of 120 female nondysphonic smokers (aged 18-31) was recruited. Participants filled out the VHI and Voice Evaluation Form. VHI's cutoff point of total score was calculated at the value of 19.50 (sensitivity: 0.780, 1-specificity: 0.133). Specifically, the construct domain of functional was 7.50 (sensitivity: 0.900, 1-specificity: 0.217), for physical it was 8.50 (sensitivity: 0.867, 1-specificity: 0.483), and for emotional it was 7.50 (sensitivity: 0.833, 1-specificity: 0.200) through the use of receiver operating characteristic. Furthermore, VHI could be used as a monitoring tool for smokers and as a feedback for smoking cessation. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Using Receiver Operating Characteristic Curve to Define the Cutoff Points of Voice Handicap Index Applied to Young Adult Male Smokers.

PubMed

Tafiadis, Dionysios; Chronopoulos, Spyridon K; Kosma, Evangelia I; Voniati, Louiza; Raptis, Vasilis; Siafaka, Vasiliki; Ziavra, Nausica

2017-07-11

Voice performance is an inextricable key factor of everyday life. Obviously, the deterioration of voice quality can cause various problems to human communication and can therefore reduce the performance of social skills (relevant to voice). The deterioration could be originated from changes inside the system of the vocal tract and larynx. Various prognostic methods exist, and among them is the Voice Handicap Index (VHI). This tool includes self-reported questionnaires, used for determining the cutoff points of total score and of its three domains relevant to young male Greek smokers. The interpretation of the calculated cutoff points can serve as a strong indicator of imminent or future evaluation by a clinician. Consistent with previous calculation, the VHI can also act as a feedback for smokers' voice condition and as monitoring procedure toward smoking cessation. Specifically, the sample consisted of 130 male nondysphonic smokers (aged 18-33 years) who all participated in the VHI test procedure. The test results (through receiver operating characteristic analysis) concluded to a total cutoff point score of 19.50 (sensitivity: 0.838, 1-specificity: 0). Also, in terms of constructs, the Functional domain was equal to 7.50 (sensitivity: 0.676, 1-specificity: 0.032), the Physical domain was equal to 7.50 (sensitivity: 0.706, 1-specificity: 0.032), and the Emotional domain was equal to 6.50 (sensitivity: 0.809, 1-specificity: 0.048). Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Screening markers for chronic atrophic gastritis in Chiapas, Mexico.

PubMed

Ley, C; Mohar, A; Guarner, J; Herrera-Goepfert, R; Figueroa, L S; Halperin, D; Parsonnet, J

2001-02-01

Intestinal-type gastric adenocarcinomas usually are preceded by chronic atrophic gastritis. Studies of gastric cancer prevention often rely on identification of this condition. In a clinical trial, we sought to determine the best serological screening method for chronic atrophic gastritis and compared our findings to the published literature. Test characteristics of potential screening tests (antibodies to Helicobacter pyloni or CagA, elevated gastrin, low pepsinogen, increased age) alone or in combination were examined among consecutive subjects enrolled in a study of H. pylori and preneoplastic gastric lesions in Chiapas, Mexico; 70% had chronic atrophic gastritis. English-language articles concerning screening for chronic atrophic gastritis were also reviewed. Sensitivity for chronic atrophic gastritis was highest for antibodies to H. pylori (92%) or CagA, or gastrin levels >25 ng/l (both 83%). Specificity, however, was low for these tests (18, 41, and 22%, respectively). Pepsinogen levels were highly specific but insensitive markers of chronic atrophic gastritis (for pepsinogen I <25 microg/l, sensitivity was 6% and specificity was 100%; for pepsinogen I:pepsinogen II ratio <2.5, sensitivity was 14% and specificity was 96%). Combinations of markers did not improve test characteristics. Screening test characteristics from the literature varied widely and did not consistently identify a good screening strategy. In this study, CagA antibodies alone had the best combination of test characteristics for chronic atrophic gastritis screening. However, no screening test was both highly sensitive and highly specific for chronic atrophic gastritis.

Transcranial magnetic stimulation distinguishes Alzheimer disease from frontotemporal dementia.

PubMed

Benussi, Alberto; Di Lorenzo, Francesco; Dell'Era, Valentina; Cosseddu, Maura; Alberici, Antonella; Caratozzolo, Salvatore; Cotelli, Maria Sofia; Micheli, Anna; Rozzini, Luca; Depari, Alessandro; Flammini, Alessandra; Ponzo, Viviana; Martorana, Alessandro; Caltagirone, Carlo; Padovani, Alessandro; Koch, Giacomo; Borroni, Barbara

2017-08-15

To determine whether a transcranial magnetic stimulation (TMS) multiparadigm approach can be used to distinguish Alzheimer disease (AD) from frontotemporal dementia (FTD). Paired-pulse TMS was used to investigate short-interval intracortical inhibition (SICI) and facilitation (ICF), long-interval intracortical inhibition, and short-latency afferent inhibition (SAI) to measure the activity of different intracortical circuits in patients with AD, patients with FTD, and healthy controls (HC). The primary outcome measures were sensitivity and specificity of TMS measures, derived from receiver operating curve analysis. A total of 175 participants met the inclusion criteria. We diagnosed 79 patients with AD, 64 patients with FTD, and 32 HC. We found that while patients with AD are characterized by a specific impairment of SAI, FTD shows a remarkable dysfunction of SICI-ICF intracortical circuits. With the use of the best indexes, TMS differentiated FTD from AD with a sensitivity of 91.8% and specificity of 88.6%, AD from HC with a sensitivity of 84.8% and specificity of 90.6%, and FTD from HC with a sensitivity of 90.2% and specificity of 78.1%. These results were confirmed in patients with mild disease. TMS is a noninvasive procedure that reliably distinguishes AD from FTD and HC and, if these findings are replicated in larger studies, could represent a useful additional diagnostic tool for clinical practice. This study provides Class III evidence that TMS measures can distinguish patients with AD from those with FTD. © 2017 American Academy of Neurology.

Identifying Depressed Older Adults in Primary Care: A Secondary Analysis of a Multisite Randomized Controlled Trial

PubMed Central

Voils, Corrine I.; Olsen, Maren K.; Williams, John W.; for the IMPACT Study Investigators

2008-01-01

Objective: To determine whether a subset of depressive symptoms could be identified to facilitate diagnosis of depression in older adults in primary care. Method: Secondary analysis was conducted on 898 participants aged 60 years or older with major depressive disorder and/or dysthymic disorder (according to DSM-IV criteria) who participated in the Improving Mood–Promoting Access to Collaborative Treatment (IMPACT) study, a multisite, randomized trial of collaborative care for depression (recruitment from July 1999 to August 2001). Linear regression was used to identify a core subset of depressive symptoms associated with decreased social, physical, and mental functioning. The sensitivity and specificity, adjusting for selection bias, were evaluated for these symptoms. The sensitivity and specificity of a second subset of 4 depressive symptoms previously validated in a midlife sample was also evaluated. Results: Psychomotor changes, fatigue, and suicidal ideation were associated with decreased functioning and served as the core set of symptoms. Adjusting for selection bias, the sensitivity of these 3 symptoms was 0.012 and specificity 0.994. The sensitivity of the 4 symptoms previously validated in a midlife sample was 0.019 and specificity was 0.997. Conclusion: We identified 3 depression symptoms that were highly specific for major depressive disorder in older adults. However, these symptoms and a previously identified subset were too insensitive for accurate diagnosis. Therefore, we recommend a full assessment of DSM-IV depression criteria for accurate diagnosis. PMID:18311416

Prediction of parturition in bitches utilizing continuous vaginal temperature measurement.

PubMed

Geiser, B; Burfeind, O; Heuwieser, W; Arlt, S

2014-02-01

The objective of this study was to determine sensitivity and specificity of a body temperature decline in bitches to predict parturition. Temperature loggers were placed into the vaginal cavity of 16 pregnant bitches on day 56-61 after estimated ovulation or first mating. This measurement technique has been validated previously and enabled continuous sampling of body temperature. The temperature loggers were expelled from the vagina before delivery of the first pup. The computed values for specificity (77-92%) were higher than sensitivity (53-69%), indicating a more precise prognosis of parturition not occurring. In conclusion, our findings may assist interpreting vaginal temperature measurements in order to predict parturition in bitches. © 2013 Blackwell Verlag GmbH.

Nucleic Acid-Based Approaches for Detection of Viral Hepatitis

PubMed Central

Behzadi, Payam; Ranjbar, Reza; Alavian, Seyed Moayed

2014-01-01

Context: To determining suitable nucleic acid diagnostics for individual viral hepatitis agent, an extensive search using related keywords was done in major medical library and data were collected, categorized, and summarized in different sections. Results: Various types of molecular biology tools can be used to detect and quantify viral genomic elements and analyze the sequences. These molecular assays are proper technologies for rapidly detecting viral agents with high accuracy, high sensitivity, and high specificity. Nonetheless, the application of each diagnostic method is completely dependent on viral agent. Conclusions: Despite rapidity, automation, accuracy, cost-effectiveness, high sensitivity, and high specificity of molecular techniques, each type of molecular technology has its own advantages and disadvantages. PMID:25789132

[Comparison of efficacy between the serum cortisol and 24 hour urine free cortisol in combined dexamethasone suppression test in the diagnosis of Cushing syndrome].

PubMed

Lu, L; Chen, J H; Zhu, H J; Song, A L; Li, M; Chen, S; Pan, H; Gong, F Y; Wang, R Z; Xing, B; Yao, Y; Feng, M; Lu, Z L

2016-07-19

To compare the sensitivity and specificity between the 24 hour urine free cortisol (24 h UFC) and serum cortisol in dexamethasone suppression test (DST) in the diagnosis of Cushing syndrome (CS). Combined low dose DST (LDDST) and high dose DST (HDDST) were carried out in 67 cases of CS with surgically confirmed cases in recent 3 years(from January 2011 to November 2015). The serum cortisol and 24 h UFC were collected simultaneously for each subject and the sensitivity and specificity of serum cortisol and 24 h UFC were compared. There were Cushing disease (CD) group (n=53), ectopic adrenocorticotropic hormone (ACTH) syndrome group (n=7) and ACTH-independent Cushing syndrome group (n=7) according to the etiology of hypercorticordism.There were no significant differences among 3 groups in gender and age.The sensitivity of serum cortisol of different cut off points(50, 110, 140 nmol/L and 50% of control)after LDDST was 97.01%, 86.57%, 83.58% and 70.15% respectively.Meanwhile, the sensitivity of cutoff point of 24 h UFC <32 nmol in combined LDDST was 92.54% in the diagnosis of Cushing syndrome.There was no significant differences in two groups between serum cortisol <110 nmol/L and 24 h UFC <32 nmol.However, the sensitivity of serum cortisol <50 nmol/L was significantly higher than 24 h UFC<32 nmol (P<0.05). Furthermore, in combined HDDST, if the suppression rate was ≥50%, the sensitivity of serum cortisol and 24 h UFC in differentiating the etiology of Cushing disease was 60.38% and 90.57%, and the specificity was 91.43% and 96.00% respectively.There were significant differences between serum cortisol and 24 h UFC in both of sensitivity and specificity (both P<0.05). In addition, if the suppression rate of 24 h UFC in HDDST was adjusted to 60.85% according to receiver operating characteristic (ROC) curve, it could have the best levels of sensitivity (92.6%) with the specificity of 85.7%. If the suppression rate of serum cortisol was adjusted to 61.53% in HDDST according to ROC curve, it could have the best sensitivity (64.8%) with the specificity of 78.6% accordingly. In combined LDDST, the serum cortisol <50 nmol/L had a higher sensitivity than the 24 h UFC<32 nmol when they were used as the criteria in determining the diagnosis of CS.In HDDST, the sensitivity and specificity of suppression rate of 24 h UFC ≥50% were better than serum cortisol to differentiate the etiology of CS.

Assessment of the Sensitizing Potential of Processed Peanut Proteins in Brown Norway Rats: Roasting Does Not Enhance Allergenicity

PubMed Central

Kroghsbo, Stine; Rigby, Neil M.; Johnson, Philip E.; Adel-Patient, Karine; Bøgh, Katrine L.; Salt, Louise J.; Mills, E. N. Clare; Madsen, Charlotte B.

2014-01-01

Background IgE-binding of process-modified foods or proteins is the most common method for examination of how food processing affects allergenicity of food allergens. How processing affects sensitization capacity is generally studied by administration of purified food proteins or food extracts and not allergens present in their natural food matrix. Objectives The aim was to investigate if thermal processing increases sensitization potential of whole peanuts via the oral route. In parallel, the effect of heating on sensitization potential of the major peanut allergen Ara h 1 was assessed via the intraperitoneal route. Methods Sensitization potential of processed peanut products and Ara h 1 was examined in Brown Norway (BN) rats by oral administration of blanched or oil-roasted peanuts or peanut butter or by intraperitoneal immunization of purified native (N-), heated (H-) or heat glycated (G-)Ara h 1. Levels of specific IgG and IgE were determined by ELISA and IgE functionality was examined by rat basophilic leukemia (RBL) cell assay. Results In rats dosed orally, roasted peanuts induced significant higher levels of specific IgE to NAra h 1 and 2 than blanched peanuts or peanut butter but with the lowest level of RBL degranulation. However, extract from roasted peanuts was found to be a superior elicitor of RBL degranulation. Process-modified Ara h 1 had similar sensitizing capacity as NAra h 1 but specific IgE reacted more readily with process-modified Ara h 1 than with native. Conclusions Peanut products induce functional specific IgE when dosed orally to BN rats. Roasted peanuts do not have a higher sensitizing capacity than blanched peanuts. In spite of this, extract from roasted peanuts is a superior elicitor of RBL cell degranulation irrespectively of the peanut product used for sensitization. The results also suggest that new epitopes are formed or disclosed by heating Ara h 1 without glucose. PMID:24805813

[Evaluation of ICT malaria immunochromatographic Binax NOW ICT P.f/P.v test for rapid diagnosis of malaria in a Colombian endemic area].

PubMed

Pabón, Adriana; Alvarez, Gonzalo; Yánez, Jorge; Céspedes, Carlos; Rodríguez, Yensa; Restrepo, Angela; Blair, Silvia

2007-06-01

One of the strategies to reduce malarial morbidity and mortality is to make an early diagnosis, using simple rapid tests which are highly sensitive and specific. Furthermore, the tests must be easy to perform and understand by local people in such a way that a suitable and prompt antimalarial treatment is guaranteed. The sensitivity and specificity was determined for the immuno-chromographic malaria dipstick (ICT Pf/Pv) test for the rapid diagnosis of malaria in Turbo, Antioquia. The sample consisted of 171 patients distributed into two groups: the first group was 118 patients with acute febrile syndrome compatible with malaria to which ICT Pf/Pv and thick smears were applied simultaneously; a second group was 53 patients with positive diagnosis by thick smear, with follow-up on the 4th and 7th days after beginning treatment. Sensitivity and specificity of the ICT Pf/Pv test for Plasmodium falciparum infections were 54.2% (95%CI: 52.0-53.4%) and 93.6% (95%CI: 93.1-94.2%), respectively. In addition, for Plasmodium vivax the sensitivity and specificity were 80% (95%CI: 77.9-82.1%) and 100% (95%CI: 99.5-100%); there was a 21.4% loss of sensitivity for P. falciparum 21.4% and a 33% loss for P. vivax malaria with parasitaemias under 500 parasites/ul. For the confirmatory test, ICT Pf/Pv showed a global sensitivity of 71.6% with 20.7% false positive and 5.6% false negative results. During follow-up, ICT showed 36% and 34% false positive results for day 4 and 7, respectively. The ICT Pf/Pv test has a poor sensitivity for P. falciparum malaria and its capacity to detect parasitemias under 500 parasites/ul is minimal. As a confirmatory test, the ICT Pf/Pv has a good sensitivity for P. falciparum. Its use for patient follow-up is not recommended.

Intermittent Cocaine Self-Administration Produces Sensitization of Stimulant Effects at the Dopamine Transporter

PubMed Central

Calipari, Erin S.; Ferris, Mark J.; Siciliano, Cody A.; Zimmer, Benjamin A.

2014-01-01

Previous literature investigating neurobiological adaptations following cocaine self-administration has shown that high, continuous levels of cocaine intake (long access; LgA) results in reduced potency of cocaine at the dopamine transporter (DAT), whereas an intermittent pattern of cocaine administration (intermittent access; IntA) results in sensitization of cocaine potency at the DAT. Here, we aimed to determine whether these changes are specific to cocaine or translate to other psychostimulants. Psychostimulant potency was assessed by fast-scan cyclic voltammetry in brain slices containing the nucleus accumbens following IntA, short access, and LgA cocaine self-administration, as well as in brain slices from naive animals. We assessed the potency of amphetamine (a releaser), and methylphenidate (a DAT blocker, MPH). MPH was selected because it is functionally similar to cocaine and structurally related to amphetamine. We found that MPH and amphetamine potencies were increased following IntA, whereas neither was changed following LgA or short access cocaine self-administration. Therefore, whereas LgA-induced tolerance at the DAT is specific to cocaine as shown in previous work, the sensitizing effects of IntA apply to cocaine, MPH, and amphetamine. This demonstrates that the pattern with which cocaine is administered is important in determining the neurochemical consequences of not only cocaine effects but potential cross-sensitization/cross-tolerance effects of other psychostimulants as well. PMID:24566123

Parametric study of modern airship productivity

NASA Technical Reports Server (NTRS)

Ardema, M. D.; Flaig, K.

1980-01-01

A method for estimating the specific productivity of both hybrid and fully buoyant airships is developed. Various methods of estimating structural weight of deltoid hybrids are discussed and a derived weight estimating relationship is presented. Specific productivity is used as a figure of merit in a parametric study of fully buoyant ellipsoidal and deltoid hybrid semi-buoyant vehicles. The sensitivity of results as a function of assumptions is also determined. No airship configurations were found to have superior specific productivity to transport airplanes.

Rapid detection of methicillin resistance in coagulase-negative staphylococci by a penicillin-binding protein 2a-specific latex agglutination test.

PubMed

Horstkotte, M A; Knobloch, J K; Rohde, H; Mack, D

2001-10-01

The detection of PBP 2a by the MRSA-Screen latex agglutination test with 201 clinical coagulase-negative staphylococci had an initial sensitivity of 98% and a high degree of specificity for Staphylococcus epidermidis strains compared to PCR for mecA. Determination of oxacillin MICs evaluated according to the new breakpoint (0.5 microg/ml) of the National Committee for Clinical Laboratory Standards exhibited an extremely low specificity for this population.

Roles of uptake, biotransformation, and target site sensitivity in determining the differential toxicity of chlorpyrifos to second to fourth instar Chironomous riparius (Meigen)

USGS Publications Warehouse

Buchwalter, D.B.; Sandahl, J.F.; Jenkins, J.J.; Curtis, L.R.

2004-01-01

Early life stages of aquatic organisms tend to be more sensitive to various chemical contaminants than later life stages. This research attempted to identify the key biological factors that determined sensitivity differences among life stages of the aquatic insect Chironomous riparius. Specifically, second to fourth instar larvae were exposed in vivo to both low and high waterborne concentrations of chlorpyrifos to examine differences in accumulation rates, chlorpyrifos biotransformation, and overall sensitivity among instars. In vitro acetylcholinesterase (AChE) assays were performed with chlorpyrifos and the metabolite, chlorpyrifos-oxon, to investigate potential target site sensitivity differences among instars. Earlier instars accumulated chlorpyrifos more rapidly than later instars. There were no major differences among instars in the biotransformation rates of chlorpyrifos to the more polar metabolites, chlorpyrifos-oxon, and chlorpyridinol (TCP). Homogenate AChE activities from second to fourth instar larvae were refractory to chlorpyrifos, even at high concentrations. In contrast, homogenate AChE activities were responsive in a dose-dependent manner to chlorpyrifos-oxon. In general, it appeared that chlorpyrifos sensitivity differences among second to fourth instar C. riparius were largely determined by differences in uptake rates. In terms of AChE depression, fourth instar homogenates were more sensitive to chlorpyrifos and chlorpyrifos-oxon than earlier instars. However, basal AChE activity in fourth instar larvae was significantly higher than basal AChE activity in second to third instar larvae, which could potentially offset the apparent increased sensitivity to the oxon. ?? 2003 Elsevier B.V. All rights reserved.

Helicobacter pylori diagnostic tests in children: review of the literature from 1999 to 2009.

PubMed

Guarner, Jeannette; Kalach, Nicolas; Elitsur, Yoram; Koletzko, Sibylle

2010-01-01

The array of tests that can be used for diagnosis of Helicobacter pylori infection is large, and it can be confusing to define which test to use particularly in children where results may not be comparable to those obtained in adult patients. Using PubMed, we reviewed the English literature from January 1999 to May 2009 to identify articles that determined sensitivity and specificity of H. pylori invasive and non-invasive diagnostic tests in children. We excluded articles that presented a review of the literature, abstracts, case reports, or series where children's results could not be separated from adult populations. Of the tissue based methods, rapid urease tests have better sensitivity than histology to detect presence of H. pylori; however, histology can detect the pathology associated with disease including gastritis, intestinal metaplasia, and other conditions that could be the cause of the child's symptoms. Culture of gastric tissues or stool has 100% specificity but sensitivity is low. Of the serologic tests, immunoblot has the best sensitivity. The urea breath tests have >75% sensitivity for detection of H. pylori before and after treatment. Immunoassays in stool using monoclonal antibodies have >95% sensitivity for detection of H. pylori before and after treatment. PCR testing can be performed in tissue and stool samples and can detect genes associated to antibiotic resistance. In summary, the current commercial non-invasive tests have adequate sensitivity and specificity for detecting the presence of H. pylori; however, endoscopy with histopathology is the only method that can detect H. pylori and lesions associated with the infection.

Histopathology of valves in infective endocarditis, diagnostic criteria and treatment considerations.

PubMed

Brandão, Tatiana J D; Januario-da-Silva, Carolina A; Correia, Marcelo G; Zappa, Monica; Abrantes, Jaime A; Dantas, Angela M R; Golebiovski, Wilma; Barbosa, Giovanna Ianini F; Weksler, Clara; Lamas, Cristiane C

2017-04-01

Infective endocarditis (IE) is a severe disease. Pathogen isolation is fundamental so as to treat effectively and reduce morbidity and mortality. Blood and valve culture and histopathology (HP) are routinely employed for this purpose. Valve HP is the gold standard for diagnosis. To determine the sensitivity and specificity of clinical criteria for IE (the modified Duke and the St Thomas' minor modifications, STH) of blood and valve culture compared to valve HP, and to evaluate antibiotic treatment duration. Prospective case series of patients, from 2006 to 2014 with surgically treated IE. Statistical analysis was done by the R software. There were 136 clinically definite episodes of IE in 133 patients. Mean age ± SD was 43 ± 15.6 years and IE was left sided in 81.6 %. HP was definite in 96 valves examined, which were used as gold standard. Sensitivity of blood culture was 61 % (CI 0.51, 0.71) and of valve culture 15 % (CI 0.07, 0.26). The modified Duke criteria were 65 % (CI 0.55, 0.75) sensitive and 33 % specific, while the STH's sensitivity was 72 % (CI 0.61, 0.80) with similar specificity. In multivariate analysis and logistic regression, the only variable with statistical significance was duration of antibiotic therapy postoperatively. Valve HP had high sensitivity and valve culture low sensitivity in the diagnosis of IE. The STH's criteria were more sensitive than the modified Duke criteria. Valve HP should guide duration of postoperative antibiotic treatment.

Diagnostic performance of a computer-assisted diagnosis system for bone scintigraphy of newly developed skeletal metastasis in prostate cancer patients: search for low-sensitivity subgroups.

PubMed

Koizumi, Mitsuru; Motegi, Kazuki; Koyama, Masamichi; Terauchi, Takashi; Yuasa, Takeshi; Yonese, Junji

2017-08-01

The computer-assisted diagnostic system for bone scintigraphy (BS) BONENAVI is used to evaluate skeletal metastasis. We investigated its diagnostic performance in prostate cancer patients with and without skeletal metastasis and searched for the problems. An artificial neural network (ANN) value was calculated in 226 prostate cancer patients (124 with skeletal metastasis and 101 without) using BS. Receiver operating characteristic curve analysis was performed and the sensitivity and specificity determined (cutoff ANN = 0.5). Patient's situation at the time of diagnosis of skeletal metastasis, computed tomography (CT) type, extent of disease (EOD), and BS uptake grade were analyzed. False-negative and false-positive results were recorded. BONENAVI showed 82% (102/124) of sensitivity and 83% (84/101) specificity for metastasis detection. There were no significant differences among CT types, although low EOD and faint BS uptake were associated with low ANN values and low sensitivity. Patients showed lower sensitivity during the follow-up period than staging work-up. False-negative lesions were often located in the pelvis or adjacent to it. They comprised not only solitary, faint BS lesions but also overlaying to urinary excretion. BONENAVI with BS has good sensitivity and specificity for detecting prostate cancer's osseous metastasis. Low EOD and faint BS uptake are associated with low sensitivity but not the CT type. Prostate cancer patients likely to have false-negative results during the follow-up period had a solitary lesion in the pelvis with faint BS uptake or lesions overlaying to urinary excretion.

Local Atopy in Childhood Adenotonsillar Hypertrophy.

PubMed

Cho, Kyu-Sup; Kim, Seong Heon; Hong, Sung-Lyong; Lee, Jaeyoung; Mun, Sue Jean; Roh, Young Eun; Kim, Young Mi; Kim, Hye-Young

2018-05-01

Background Although the cause of adenotonsillar hypertrophy remains unknown, some studies have shown that allergy may be a risk factor. Purpose This study determined the levels of allergen-specific immunoglobulin E (sIgE) in the adenotonsillar tissues of children with adenotonsillar hypertrophy and evaluated the clinical significance of local atopy in adenotonsillar tissues. Methods We measured 21 types of specific immunoglobulin E in the serum and adenotonsillar tissues of 102 children with adenotonsillar hypertrophy and compared the sensitization patterns of the serum and local tissues. The patients were divided into three groups-atopy, local atopy, and nonatopy-according to the sensitization of serum and adenotonsillar tissues, and the clinical symptoms among the groups were analyzed. Results Seventy-two (70.6%) children with adenotonsillar hypertrophy were sensitized to more than one allergen in the serum and/or adenotonsillar tissue. Thirty (29.4%) children had no IgE positivity to any allergen in both serum and adenotonsillar tissues. Fifty-five (53.9%) were sensitized to at least one allergen in the serum. Seventy (68.6%) were sensitized to at least one allergen in the adenotonsillar tissue. Seventeen (36.2%) of 47 children with specific immunoglobulin E-negative serum had specific immunoglobulin E-positive adenotonsillar tissues. The rate of specific immunoglobulin E was significantly higher in local tissues than in serum. The rate of inhalant allergen specific immunoglobulin E was significantly higher in the adenoids than in the tonsils. However, the rate of food allergen specific immunoglobulin E was significantly higher in the tonsils than adenoids. The lifetime prevalence of asthma and allergic rhinitis, recent symptoms or treatment of allergic rhinitis, and severity of nasal symptoms (rhinorrhea, sneezing, and nasal itching) were significantly higher in children with local atopy than with nonatopy. Conclusions These results confirm that allergic response may be a risk factor for adenotonsillar hypertrophy. Local allergic inflammation may play an important role in childhood adenotonsillar hypertrophy, and local atopy in adenotonsillar tissues can cause respiratory allergic symptoms in children.

Diabetic retinopathy screening using deep neural network.

PubMed

Ramachandran, Nishanthan; Hong, Sheng Chiong; Sime, Mary J; Wilson, Graham A

2017-09-07

There is a burgeoning interest in the use of deep neural network in diabetic retinal screening. To determine whether a deep neural network could satisfactorily detect diabetic retinopathy that requires referral to an ophthalmologist from a local diabetic retinal screening programme and an international database. Retrospective audit. Diabetic retinal photos from Otago database photographed during October 2016 (485 photos), and 1200 photos from Messidor international database. Receiver operating characteristic curve to illustrate the ability of a deep neural network to identify referable diabetic retinopathy (moderate or worse diabetic retinopathy or exudates within one disc diameter of the fovea). Area under the receiver operating characteristic curve, sensitivity and specificity. For detecting referable diabetic retinopathy, the deep neural network had an area under receiver operating characteristic curve of 0.901 (95% confidence interval 0.807-0.995), with 84.6% sensitivity and 79.7% specificity for Otago and 0.980 (95% confidence interval 0.973-0.986), with 96.0% sensitivity and 90.0% specificity for Messidor. This study has shown that a deep neural network can detect referable diabetic retinopathy with sensitivities and specificities close to or better than 80% from both an international and a domestic (New Zealand) database. We believe that deep neural networks can be integrated into community screening once they can successfully detect both diabetic retinopathy and diabetic macular oedema. © 2017 Royal Australian and New Zealand College of Ophthalmologists.

Magnetic Resonance Imaging for Patellofemoral Chondromalacia: Is There a Role for T2 Mapping?

PubMed

van Eck, Carola F; Kingston, R Scott; Crues, John V; Kharrazi, F Daniel

2017-11-01

Patellofemoral pain is common, and treatment is guided by the presence and grade of chondromalacia. To evaluate and compare the sensitivity and specificity in detecting and grading chondral abnormalities of the patella between proton density fat suppression (PDFS) and T2 mapping magnetic resonance imaging (MRI). Cohort study; Level of evidence, 2. A total of 25 patients who underwent MRI of the knee with both a PDFS sequence and T2 mapping and subsequently underwent arthroscopic knee surgery were included. The cartilage surface of the patella was graded on both MRI sequences by 2 independent, blinded radiologists. Cartilage was then graded during arthroscopic surgery by a sports medicine fellowship-trained orthopaedic surgeon. Reliability, sensitivity, specificity, and accuracy were determined for both MRI methods. The findings during arthroscopic surgery were considered the gold standard. Intraobserver and interobserver agreement for both PDFS (98.5% and 89.4%, respectively) and T2 mapping (99.4% and 91.3%, respectively) MRI were excellent. For T2 mapping, the sensitivity (61%) and specificity (64%) were comparable, whereas for PDFS there was a lower sensitivity (37%) but higher specificity (81%) in identifying cartilage abnormalities. This resulted in a similar accuracy for PDFS (59%) and T2 mapping (62%). Both PDFS and T2 mapping MRI were reliable but only moderately accurate in predicting patellar chondromalacia found during knee arthroscopic surgery.

Sensitivity and specificity of ultrasonography and low-field magnetic resonance imaging for diagnosing arthritis.

PubMed

Broll, Matthias; Albrecht, Katinka; Tarner, Ingo; Müller-Ladner, Ulf; Strunk, Johannes

2012-01-01

To evaluate the value of grey-scale ultrasonography (US) including power Doppler ultrasonography (PDUS) and low-field magnetic resonance imaging (MRI) for the diagnosis of arthritis in a diagnostic phase III study. Fifty consecutive patients with suspected arthritis were included in the study. Following a standardised protocol, US of the carpus and the metacarpophalangeal (MCP) joints of the dominant hand was performed. Subsequently, low-field MRI was done using standard sequences, with contrast agent (Gadolinium DTPA) administered to 29 patients. In 32 out of 50 patients a clinical diagnosis of arthritis was established. In grey-scale ultrasonography including PDUS, sensitivity and specificity were determined as 0.94 and 0.5, respectively, for synovitis (effusion and hypertrophy), 0.72 and 0.94, respectively, for Doppler signals, and 0.38 and 1.0, respectively, for bone erosions. In low-field MRI, sensitivity and specificity values were 0.77 and 0.75, respectively, for synovitis (when using contrast agent), 0.48 and 0.78, respectively, for bone marrow oedema, and 0.58 and 0.83, respectively, for bone erosion. Both grey-scale ultrasonography including PDUS and low-field MRI are suitable imaging methods for diagnosing arthritis at an early stage. However, PDUS displays a higher specificity and almost the same sensitivity as compared to contrast-enhanced MRI, while being a much simpler and less costly procedure.

Use of shear wave elastography to differentiate benign and malignant breast lesions

PubMed Central

Olgun, Deniz Çebi; Korkmazer, Bora; Kılıç, Fahrettin; Dikici, Atilla Süleyman; Velidedeoğlu, Mehmet; Aydoğan, Fatih; Kantarcı, Fatih; Yılmaz, Mehmet Halit

2014-01-01

PURPOSE We aimed to determine the correlations between the elasticity values of solid breast masses and histopathological findings to define cutoff elasticity values differentiating malignant from benign lesions. MATERIALS and METHODS A total of 115 solid breast lesions of 109 consecutive patients were evaluated prospectively using shear wave elastography (SWE). Two orthogonal elastographic images of each lesion were obtained. Minimum, mean, and maximum elasticity values were calculated in regions of interest placed over the stiffest areas on the two images; we also calculated mass/fat elasticity ratios. Correlation of elastographic measurements with histopathological results were studied. RESULTS Eighty-three benign and thirty-two malignant lesions were histopathologically diagnosed. The minimum, mean, and maximum elasticity values, and the mass/fat elasticity ratios of malignant lesions, were significantly higher than those of benign lesions. The cutoff value was 45.7 kPa for mean elasticity (sensitivity, 96%; specificity, 95%), 54.3 kPa for maximum elasticity (sensitivity, 95%; specificity, 94%), 37.1 kPa for minimum elasticity (sensitivity, 96%; specificity, 95%), and 4.6 for the mass/fat elasticity ratio (sensitivity, 97%; specificity, 95%). CONCLUSION SWE yields additional valuable quantitative data to ultrasonographic examination on solid breast lesions. SWE may serve as a complementary tool for diagnosis of breast lesions. Long-term clinical studies are required to accurately select lesions requiring biopsy. PMID:24509183

Development of a rapid and visual nucleotide detection method for a Chinese epidemic strain of Orientia tsutsugamushi based on recombinase polymerase amplification assay and lateral flow test.

PubMed

Qi, Yong; Yin, Qiong; Shao, Yinxiu; Cao, Min; Li, Suqin; Chen, Hongxia; Shen, Wanpeng; Rao, Jixian; Li, Jiameng; Li, Xiaoling; Sun, Yu; Lin, Yu; Deng, Yi; Zeng, Wenwen; Zheng, Shulong; Liu, Suyun; Li, Yuexi

2018-05-01

Orientia tsutsugamushi is an obligate intracellular pathogen that causes scrub typhus. Diagnosing scrub typhus remains a challenge, and a sensitive, specific, simple, and rapid diagnostic test is still needed. A recombinase polymerase amplification (RPA) assay combined with a lateral flow (LF) test targeting the 56-kDa gene of a Karp-like strain of O. tsutsugamushi was developed and optimized. The detection limits, sensitivity, specificity, and simulative clinical performance were evaluated. Primers and probe were screened to establish the RPA assay, and the reaction conditions were optimized. The detection limit was 10 copies/reaction in detecting plasmid DNA and 12 copies/reaction in detecting genomic DNA. The RPA-LF method could differentiate O. tsutsugamushi from other phylogenetically related bacteria. The sensitivity was 100% and specificity was over 90%, when evaluated using infected animal samples or simulative clinical samples. Furthermore, the method was completed in 20min at 37°C followed by a 3-5min incubation at room temperature for the development of an immunochromatographic strip, and the results could be determined visually. This method is promising for wide-ranging use in basic medical units considering that it requires minimal instruments and infrastructure and is highly time-efficient, sensitive, and specific for diagnosing scrub typhus. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

Quantitative Analysis of Swallowing Function Between Dysphagia Patients and Healthy Subjects Using High-Resolution Manometry

PubMed Central

2017-01-01

Objective To compare swallowing function between healthy subjects and patients with pharyngeal dysphagia using high resolution manometry (HRM) and to evaluate the usefulness of HRM for detecting pharyngeal dysphagia. Methods Seventy-five patients with dysphagia and 28 healthy subjects were included in this study. Diagnosis of dysphagia was confirmed by a videofluoroscopy. HRM was performed to measure pressure and timing information at the velopharynx (VP), tongue base (TB), and upper esophageal sphincter (UES). HRM parameters were compared between dysphagia and healthy groups. Optimal threshold values of significant HRM parameters for dysphagia were determined. Results VP maximal pressure, TB maximal pressure, UES relaxation duration, and UES resting pressure were lower in the dysphagia group than those in healthy group. UES minimal pressure was higher in dysphagia group than in the healthy group. Receiver operating characteristic (ROC) analyses were conducted to validate optimal threshold values for significant HRM parameters to identify patients with pharyngeal dysphagia. With maximal VP pressure at a threshold value of 144.0 mmHg, dysphagia was identified with 96.4% sensitivity and 74.7% specificity. With maximal TB pressure at a threshold value of 158.0 mmHg, dysphagia was identified with 96.4% sensitivity and 77.3% specificity. At a threshold value of 2.0 mmHg for UES minimal pressure, dysphagia was diagnosed at 74.7% sensitivity and 60.7% specificity. Lastly, UES relaxation duration of <0.58 seconds had 85.7% sensitivity and 65.3% specificity, and UES resting pressure of <75.0 mmHg had 89.3% sensitivity and 90.7% specificity for identifying dysphagia. Conclusion We present evidence that HRM could be a useful evaluation tool for detecting pharyngeal dysphagia. PMID:29201816

Sensitivity, Specificity, and Posttest Probability of Parotid Fine-Needle Aspiration: A Systematic Review and Meta-analysis.

PubMed

Liu, C Carrie; Jethwa, Ashok R; Khariwala, Samir S; Johnson, Jonas; Shin, Jennifer J

2016-01-01

(1) To analyze the sensitivity and specificity of fine-needle aspiration (FNA) in distinguishing benign from malignant parotid disease. (2) To determine the anticipated posttest probability of malignancy and probability of nondiagnostic and indeterminate cytology with parotid FNA. Independently corroborated computerized searches of PubMed, Embase, and Cochrane Central Register were performed. These were supplemented with manual searches and input from content experts. Inclusion/exclusion criteria specified diagnosis of parotid mass, intervention with both FNA and surgical excision, and enumeration of both cytologic and surgical histopathologic results. The primary outcomes were sensitivity, specificity, and posttest probability of malignancy. Heterogeneity was evaluated with the I(2) statistic. Meta-analysis was performed via a 2-level mixed logistic regression model. Bayesian nomograms were plotted via pooled likelihood ratios. The systematic review yielded 70 criterion-meeting studies, 63 of which contained data that allowed for computation of numerical outcomes (n = 5647 patients; level 2a) and consideration of meta-analysis. Subgroup analyses were performed in studies that were prospective, involved consecutive patients, described the FNA technique utilized, and used ultrasound guidance. The I(2) point estimate was >70% for all analyses, except within prospectively obtained and ultrasound-guided results. Among the prospective subgroup, the pooled analysis demonstrated a sensitivity of 0.882 (95% confidence interval [95% CI], 0.509-0.982) and a specificity of 0.995 (95% CI, 0.960-0.999). The probabilities of nondiagnostic and indeterminate cytology were 0.053 (95% CI, 0.030-0.075) and 0.147 (95% CI, 0.106-0.188), respectively. FNA has moderate sensitivity and high specificity in differentiating malignant from benign parotid lesions. Considerable heterogeneity is present among studies. © American Academy of Otolaryngology-Head and Neck Surgery Foundation 2015.

Quantitative Analysis of Swallowing Function Between Dysphagia Patients and Healthy Subjects Using High-Resolution Manometry.

PubMed

Park, Chul-Hyun; Kim, Don-Kyu; Lee, Yong-Taek; Yi, Youbin; Lee, Jung-Sang; Kim, Kunwoo; Park, Jung Ho; Yoon, Kyung Jae

2017-10-01

To compare swallowing function between healthy subjects and patients with pharyngeal dysphagia using high resolution manometry (HRM) and to evaluate the usefulness of HRM for detecting pharyngeal dysphagia. Seventy-five patients with dysphagia and 28 healthy subjects were included in this study. Diagnosis of dysphagia was confirmed by a videofluoroscopy. HRM was performed to measure pressure and timing information at the velopharynx (VP), tongue base (TB), and upper esophageal sphincter (UES). HRM parameters were compared between dysphagia and healthy groups. Optimal threshold values of significant HRM parameters for dysphagia were determined. VP maximal pressure, TB maximal pressure, UES relaxation duration, and UES resting pressure were lower in the dysphagia group than those in healthy group. UES minimal pressure was higher in dysphagia group than in the healthy group. Receiver operating characteristic (ROC) analyses were conducted to validate optimal threshold values for significant HRM parameters to identify patients with pharyngeal dysphagia. With maximal VP pressure at a threshold value of 144.0 mmHg, dysphagia was identified with 96.4% sensitivity and 74.7% specificity. With maximal TB pressure at a threshold value of 158.0 mmHg, dysphagia was identified with 96.4% sensitivity and 77.3% specificity. At a threshold value of 2.0 mmHg for UES minimal pressure, dysphagia was diagnosed at 74.7% sensitivity and 60.7% specificity. Lastly, UES relaxation duration of <0.58 seconds had 85.7% sensitivity and 65.3% specificity, and UES resting pressure of <75.0 mmHg had 89.3% sensitivity and 90.7% specificity for identifying dysphagia. We present evidence that HRM could be a useful evaluation tool for detecting pharyngeal dysphagia.

Efficacy of preoperative neck ultrasound in the detection of cervical lymph node metastasis from thyroid cancer.

PubMed

Hwang, Harry S; Orloff, Lisa A

2011-03-01

This study was performed to assess the diagnostic accuracy of surgeon-performed preoperative neck ultrasound (US) in the detection of both central and lateral cervical lymph node metastases from thyroid cancer. Prospective cohort study. Data for all patients with thyroid cancers and follicular thyroid lesions who were evaluated by means of preoperative neck US were reviewed. The cervical lymph nodes were assessed for suspicion of metastasis based on US characteristics. The diagnostic accuracy of US was determined according to whether histologically confirmed cancer was present in surgical cervical lymph node specimens. The sensitivity and specificity of US in predicting papillary thyroid carcinoma (PTC) metastasis in the central neck were 30.0% and 86.8%, respectively. The sensitivity and specificity of US in predicting metastasis in the lateral neck were 93.8% and 80.0%, respectively. A subset of patients underwent US followed by revision neck dissection for PTC, and the sensitivity and specificity of US in predicting metastasis in the lateral neck were 100% and 100%, respectively. Preoperative neck US is a valuable tool in assessing patients with thyroid cancers. The highly sensitive and specific nature of US in predicting cervical lymph node metastasis in the lateral neck, especially in the setting of recurrent disease, can provide reliable information to assist in surgical management. Although US for central compartment lymphadenopathy in the presence of the thyroid gland is less sensitive and specific than US for the lateral neck, it still provides useful information that can be obtained at the same time the primary thyroid pathology is assessed. Copyright © 2010 The American Laryngological, Rhinological, and Otological Society, Inc.

Sensitivity, Specificity, and Posttest Probability of Parotid Fine-Needle Aspiration: A Systematic Review and Meta-analysis

PubMed Central

Liu, C. Carrie; Jethwa, Ashok R.; Khariwala, Samir S.; Johnson, Jonas; Shin, Jennifer J.

2016-01-01

Objectives (1) To analyze the sensitivity and specificity of fine-needle aspiration (FNA) in distinguishing benign from malignant parotid disease. (2) To determine the anticipated posttest probability of malignancy and probability of non-diagnostic and indeterminate cytology with parotid FNA. Data Sources Independently corroborated computerized searches of PubMed, Embase, and Cochrane Central Register were performed. These were supplemented with manual searches and input from content experts. Review Methods Inclusion/exclusion criteria specified diagnosis of parotid mass, intervention with both FNA and surgical excision, and enumeration of both cytologic and surgical histopathologic results. The primary outcomes were sensitivity, specificity, and posttest probability of malignancy. Heterogeneity was evaluated with the I2 statistic. Meta-analysis was performed via a 2-level mixed logistic regression model. Bayesian nomograms were plotted via pooled likelihood ratios. Results The systematic review yielded 70 criterion-meeting studies, 63 of which contained data that allowed for computation of numerical outcomes (n = 5647 patients; level 2a) and consideration of meta-analysis. Subgroup analyses were performed in studies that were prospective, involved consecutive patients, described the FNA technique utilized, and used ultrasound guidance. The I2 point estimate was >70% for all analyses, except within prospectively obtained and ultrasound-guided results. Among the prospective subgroup, the pooled analysis demonstrated a sensitivity of 0.882 (95% confidence interval [95% CI], 0.509–0.982) and a specificity of 0.995 (95% CI, 0.960–0.999). The probabilities of nondiagnostic and indeterminate cytology were 0.053 (95% CI, 0.030–0.075) and 0.147 (95% CI, 0.106–0.188), respectively. Conclusion FNA has moderate sensitivity and high specificity in differentiating malignant from benign parotid lesions. Considerable heterogeneity is present among studies. PMID:26428476

Evaluation of Gamma Interferon and Antibody Tuberculosis Tests in Alpacas

PubMed Central

Holder, Tom; Clifford, Derek; Dexter, Ian; Brewer, Jacky; Smith, Noel; Waring, Laura; Crawshaw, Tim; Gillgan, Steve; Lyashchenko, Konstantin; Lawrence, John; Clarke, John; de la Rua-Domenech, Ricardo; Vordermeier, Martin

2012-01-01

We describe the performance of cell-based and antibody blood tests for the antemortem diagnosis of tuberculosis (TB) in South American camelids (SAC). The sensitivity and specificity of the gamma interferon (IFN-γ) release assay, two lateral flow rapid antibody tests (Stat-Pak and Dual Path Platform [DPP]), and two enzyme-linked immunosorbent assay (ELISA)-based antibody tests (Idexx and Enferplex) were determined using diseased alpacas from Mycobacterium bovis culture-confirmed breakdown herds and TB-free alpacas from geographical areas with no history of bovine TB, respectively. Our results show that while the sensitivities of the IFN-γ and antibody tests were similar (range of 57.7% to 66.7%), the specificity of the IFN-γ test (89.1%) was lower than those of any of the antibody tests (range of 96.4% to 97.4%). This lower specificity of the IFN-γ test was at least in part due to undisclosed Mycobacterium microti infection in the TB-free cohort, which stimulates a positive purified protein derivative (PPD) response. The sensitivity of infection detection could be increased by combining two antibody tests, but even the use of all four antibody tests failed to detect all diseased alpacas. These antibody-negative alpacas were IFN-γ positive. We found that the maximum sensitivity could be achieved only by the combination of the IFN-γ test with two antibody tests in a “test package,” although this resulted in decreased specificity. The data from this evaluation of tests with defined sensitivity and specificity provide potential options for antemortem screening of SAC for TB in herd breakdown situations and could also find application in movement testing and tracing investigations. PMID:22914362

Arrhythmia discrimination by physician and defibrillator: importance of atrial channel.

PubMed

Diemberger, Igor; Martignani, Cristian; Biffi, Mauro; Frabetti, Lorenzo; Valzania, Cinzia; Cooke, Robin M T; Rapezzi, Claudio; Branzi, Angelo; Boriani, Giuseppe

2012-01-26

Many ICD carriers experience inappropriate shocks, but the relative merits of dual- /single-chamber devices for arrhythmia discrimination still remain unclear. We explored possible advantages of the atrial data provided by dual-chamber implantable defibrillators (ICD) for discrimination of real-life supraventricular/ventricular tachyarrhythmias (SVT/VT). 100 dual-chamber traces from 24 ICD were blindly reviewed in dual-chamber and simulated single-chamber (with/without discriminator data) reading modes by five electrophysiologists who determined chamber of origin and provided Likert-scale "confidence" ratings. We assessed 1) intra/interobserver concordance; 2) diagnostic accuracy, using expert diagnoses as a reference standard; 3) ROC curves of sensitivity/specificity of "likelihood perception" scores, generated by combining chamber-of-origin diagnostic judgments with Likert-scale "confidence" ratings. We also assessed diagnostic accuracy of automated discrimination by all possible dual-/single-chamber algorithm configurations. Interobserver concordance was "substantial" (modified Cohen kappa-test values for dual-/single-chamber, 0.79/0.68); intraobserver concordance "almost complete" (kappa ≥ 0.89). Dual-chamber mode provided best diagnostic sensitivity/specificity (99%/92%) and highest reader confidence (p<0.001). Area under ROC curves of sensitivity/specificity values for the "likelihood perception" score (representing electrophysiologists' perceptions of the likelihood that an episode was of ventricular origin) was highest in dual-chamber mode (0.98 vs. 0.93 for both single-chamber modes; p<0.001). Regarding automated discrimination, all four dual-chamber configurations conferred 100% sensitivity (specificity values ranged 39%-88%), whereas single-chamber configurations appeared inferior (best sensitivity/specificity combination, 89%/64%). Availability of the atrial channel helps in reducing inappropriate ICD therapies by providing relevant advantages in terms of both appropriate cardiologist's post-hoc discrimination of SVT/VT (improving program tailoring) and automated arrhythmia discrimination. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Preoperative identification of a suspicious adnexal mass: a systematic review and meta-analysis.

PubMed

Dodge, Jason E; Covens, Allan L; Lacchetti, Christina; Elit, Laurie M; Le, Tien; Devries-Aboud, Michaela; Fung-Kee-Fung, Michael

2012-07-01

To systematically review the existing literature in order to determine the optimal strategy for preoperative identification of the adnexal mass suspicious for ovarian cancer. A review of all systematic reviews and guidelines published between 1999 and 2009 was conducted as a first step. After the identification of a 2004 AHRQ systematic review on the topic, searches of MEDLINE for studies published since 2004 was also conducted to update and supplement the evidentiary base. A bivariate, random-effects meta-regression model was used to produce summary estimates of sensitivity and specificity and to plot summary ROC curves with 95% confidence regions. Four meta-analyses and 53 primary studies were included in this review. The diagnostic performance of each technology was compared and contrasted based on the summary data on sensitivity and specificity obtained from the meta-analysis. Results suggest that 3D ultrasonography has both a higher sensitivity and specificity when compared to 2D ultrasound. Established morphological scoring systems also performed with respectable sensitivity and specificity, each with equivalent diagnostic competence. Explicit scoring systems did not perform as well as other diagnostic testing methods. Assessment of an adnexal mass by colour Doppler technology was neither as sensitive nor as specific as simple ultrasonography. Of the three imaging modalities considered, MRI appeared to perform the best, although results were not statistically different from CT. PET did not perform as well as either MRI or CT. The measurement of the CA-125 tumour marker appears to be less reliable than do other available assessment methods. The best available evidence was collected and included in this rigorous systematic review and meta-analysis. The abundant evidentiary base provided the context and direction for the diagnosis of early-staged ovarian cancer. Copyright © 2012 Elsevier Inc. All rights reserved.

Artificial neural networks: Predicting head CT findings in elderly patients presenting with minor head injury after a fall.

PubMed

Dusenberry, Michael W; Brown, Charles K; Brewer, Kori L

2017-02-01

To construct an artificial neural network (ANN) model that can predict the presence of acute CT findings with both high sensitivity and high specificity when applied to the population of patients≥age 65years who have incurred minor head injury after a fall. An ANN was created in the Python programming language using a population of 514 patients ≥ age 65 years presenting to the ED with minor head injury after a fall. The patient dataset was divided into three parts: 60% for "training", 20% for "cross validation", and 20% for "testing". Sensitivity, specificity, positive and negative predictive values, and accuracy were determined by comparing the model's predictions to the actual correct answers for each patient. On the "cross validation" data, the model attained a sensitivity ("recall") of 100.00%, specificity of 78.95%, PPV ("precision") of 78.95%, NPV of 100.00%, and accuracy of 88.24% in detecting the presence of positive head CTs. On the "test" data, the model attained a sensitivity of 97.78%, specificity of 89.47%, PPV of 88.00%, NPV of 98.08%, and accuracy of 93.14% in detecting the presence of positive head CTs. ANNs show great potential for predicting CT findings in the population of patients ≥ 65 years of age presenting with minor head injury after a fall. As a good first step, the ANN showed comparable sensitivity, predictive values, and accuracy, with a much higher specificity than the existing decision rules in clinical usage for predicting head CTs with acute intracranial findings. Copyright © 2016 Elsevier Inc. All rights reserved.

Evaluation of gamma interferon and antibody tuberculosis tests in alpacas.

PubMed

Rhodes, Shelley; Holder, Tom; Clifford, Derek; Dexter, Ian; Brewer, Jacky; Smith, Noel; Waring, Laura; Crawshaw, Tim; Gillgan, Steve; Lyashchenko, Konstantin; Lawrence, John; Clarke, John; de la Rua-Domenech, Ricardo; Vordermeier, Martin

2012-10-01

We describe the performance of cell-based and antibody blood tests for the antemortem diagnosis of tuberculosis (TB) in South American camelids (SAC). The sensitivity and specificity of the gamma interferon (IFN-γ) release assay, two lateral flow rapid antibody tests (Stat-Pak and Dual Path Platform [DPP]), and two enzyme-linked immunosorbent assay (ELISA)-based antibody tests (Idexx and Enferplex) were determined using diseased alpacas from Mycobacterium bovis culture-confirmed breakdown herds and TB-free alpacas from geographical areas with no history of bovine TB, respectively. Our results show that while the sensitivities of the IFN-γ and antibody tests were similar (range of 57.7% to 66.7%), the specificity of the IFN-γ test (89.1%) was lower than those of any of the antibody tests (range of 96.4% to 97.4%). This lower specificity of the IFN-γ test was at least in part due to undisclosed Mycobacterium microti infection in the TB-free cohort, which stimulates a positive purified protein derivative (PPD) response. The sensitivity of infection detection could be increased by combining two antibody tests, but even the use of all four antibody tests failed to detect all diseased alpacas. These antibody-negative alpacas were IFN-γ positive. We found that the maximum sensitivity could be achieved only by the combination of the IFN-γ test with two antibody tests in a "test package," although this resulted in decreased specificity. The data from this evaluation of tests with defined sensitivity and specificity provide potential options for antemortem screening of SAC for TB in herd breakdown situations and could also find application in movement testing and tracing investigations.

Development and validation of a registry-based definition of eosinophilic esophagitis in Denmark

PubMed Central

Dellon, Evan S; Erichsen, Rune; Pedersen, Lars; Shaheen, Nicholas J; Baron, John A; Sørensen, Henrik T; Vyberg, Mogens

2013-01-01

AIM: To develop and validate a case definition of eosinophilic esophagitis (EoE) in the linked Danish health registries. METHODS: For case definition development, we queried the Danish medical registries from 2006-2007 to identify candidate cases of EoE in Northern Denmark. All International Classification of Diseases-10 (ICD-10) and prescription codes were obtained, and archived pathology slides were obtained and re-reviewed to determine case status. We used an iterative process to select inclusion/exclusion codes, refine the case definition, and optimize sensitivity and specificity. We then re-queried the registries from 2008-2009 to yield a validation set. The case definition algorithm was applied, and sensitivity and specificity were calculated. RESULTS: Of the 51 and 49 candidate cases identified in both the development and validation sets, 21 and 24 had EoE, respectively. Characteristics of EoE cases in the development set [mean age 35 years; 76% male; 86% dysphagia; 103 eosinophils per high-power field (eos/hpf)] were similar to those in the validation set (mean age 42 years; 83% male; 67% dysphagia; 77 eos/hpf). Re-review of archived slides confirmed that the pathology coding for esophageal eosinophilia was correct in greater than 90% of cases. Two registry-based case algorithms based on pathology, ICD-10, and pharmacy codes were successfully generated in the development set, one that was sensitive (90%) and one that was specific (97%). When these algorithms were applied to the validation set, they remained sensitive (88%) and specific (96%). CONCLUSION: Two registry-based definitions, one highly sensitive and one highly specific, were developed and validated for the linked Danish national health databases, making future population-based studies feasible. PMID:23382628

Value of parents' estimates of children's developmental ages.

PubMed

Glascoe, F P; Sandler, H

1995-11-01

To determine whether parents' estimates of children's developmental ages can function as a prescreening technique. Parents of 234 children from birth to 77 months of age seeking well-child care in pediatric offices were queried in two separate studies. In the first study, parents were asked to give an estimate of their child's overall developmental age and, in the second study, to estimate ages in each of six developmental domains. Children were administered a range of screening measures of intelligence, speech-language, and adoptive behavior. The overall age-estimate, if less than chronologic age, was 75% sensitive to likely developmental problems and, if equal to or greater than chronologic age, was 90% specific in identifying children likely to have typical development. Age estimates for each developmental domain were 81% sensitive to likely developmental problems if less than chronologic age in the domains of fine motor, language, grass motor, or behavior, and 62% specific if equal to or greater than chronologic age. Estimates at or below chronologic age in receptive language or personal-social domains were 90% sensitive and 43% specific in identifying likely behavior problems. There were no differences in the accuracy of parents estimates on the basis of children's age, gender, race, parents' level of education, or parenting experience. Parents' overall age-estimates provided a sensitive and specific indicator of global developmental status, but insufficient information about strengths and weaknesses to enable focused referrals for services. In contrast, discrete patterns of age estimates in each developmental domain sensitively discriminated children with developmental versus behavioral problems, although specificity was limited. Age estimates appear to be a potentially helpful method for identifying a subset of children in need of thorough screening, although further research is needed on a larger sample given diagnostic rather than screening tests.

Sensitivity and Specificity of Cetuximab-IRDye800CW to Identify Regional Metastatic Disease in Head and Neck Cancer.

PubMed

Rosenthal, Eben L; Moore, Lindsay S; Tipirneni, Kiranya; de Boer, Esther; Stevens, Todd M; Hartman, Yolanda E; Carroll, William R; Zinn, Kurt R; Warram, Jason M

2017-08-15

Purpose: Comprehensive cervical lymphadenectomy can be associated with significant morbidity and poor quality of life. This study evaluated the sensitivity and specificity of cetuximab-IRDye800CW to identify metastatic disease in patients with head and neck cancer. Experimental Design: Consenting patients scheduled for curative resection were enrolled in a clinical trial to evaluate the safety and specificity of cetuximab-IRDye800CW. Patients ( n = 12) received escalating doses of the study drug. Where indicated, cervical lymphadenectomy accompanied primary tumor resection, which occurred 3 to 7 days following intravenous infusion of cetuximab-IRDye800CW. All 471 dissected lymph nodes were imaged with a closed-field, near-infrared imaging device during gross processing of the fresh specimens. Intraoperative imaging of exposed neck levels was performed with an open-field fluorescence imaging device. Blinded assessments of the fluorescence data were compared to histopathology to calculate sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). Results: Of the 35 nodes diagnosed pathologically positive, 34 were correctly identified with fluorescence imaging, yielding a sensitivity of 97.2%. Of the 435 pathologically negative nodes, 401 were correctly assessed using fluorescence imaging, yielding a specificity of 92.7%. The NPV was determined to be 99.7%, and the PPV was 50.7%. When 37 fluorescently false-positive nodes were sectioned deeper (1 mm) into their respective blocks, metastatic cancer was found in 8.1% of the recut nodal specimens, which altered staging in two of those cases. Conclusions: Fluorescence imaging of lymph nodes after systemic cetuximab-IRDye800CW administration demonstrated high sensitivity and was capable of identifying additional positive nodes on deep sectioning. Clin Cancer Res; 23(16); 4744-52. ©2017 AACR . ©2017 American Association for Cancer Research.

Sensitivity and Specificity of Laser-Scanning In Vivo Confocal Microscopy for Filamentous Fungal Keratitis: Role of Observer Experience.

PubMed

Kheirkhah, Ahmad; Syed, Zeba A; Satitpitakul, Vannarut; Goyal, Sunali; Müller, Rodrigo; Tu, Elmer Y; Dana, Reza

2017-07-01

To determine sensitivity and specificity of laser-scanning in vivo confocal microscopy (LS-IVCM) for detection of filamentous fungi in patients with microbial keratitis and to evaluate the effect of observer's imaging experience on these parameters. Retrospective reliability study. This study included 21 patients with filamentous fungal keratitis and 24 patients with bacterial keratitis (as controls). The etiology of infection was confirmed based on the response to specific therapy regardless of culture results. All patients had undergone full-thickness corneal imaging by a LS-IVCM (Heidelberg Retina Tomograph 3 with Rostock Cornea Module; Heidelberg Engineering, Heidelberg, Germany). The images were evaluated for the presence of fungal filaments by 2 experienced observers and 2 inexperienced observers. All observers were masked to the clinical and microbiologic data. The mean number of images obtained per eye was 917 ± 353. The average sensitivity of LS-IVCM for detecting fungal filaments was 71.4% ± 0% for the experienced observers and 42.9% ± 6.7% for the inexperienced observers. The average specificity was 89.6% ± 3.0% and 87.5% ± 17.7% for these 2 groups of observers, respectively. Although there was a good agreement between the 2 experienced observers (κ = 0.77), the inexperienced observers showed only a moderate interobserver agreement (κ = 0.51). The LS-IVCM sensitivity was higher in patients with fungal infections who had positive culture or longer duration of the disease. Although LS-IVCM has a high specificity for diagnosing filamentous fungal keratitis, its sensitivity is moderate and highly dependent on the level of the observer's experience and training with this imaging modality. Copyright © 2017 Elsevier Inc. All rights reserved.

[The diagnostic value of ultrasonic elastography and ultrasonography comprehensive score in cervical lesions].

PubMed

Lu, R; Xiao, Y

2017-07-18

Objective: To evaluate the clinical value of ultrasonic elastography and ultrasonography comprehensive scoring method in the diagnosis of cervical lesions. Methods: A total of 116 patients were selected from the Department of Gynecology of the first hospital affiliated with Central South University from March 2014 to September 2015.All of the lesions were preoperatively examined by Doppler Ultrasound and elastography.The elasticity score was determined by a 5-point scoring method. Calculation of the strain ratio was based on a comparison of the average strain measured in the lesion with the adjacent tissue of the same depth, size, and shape.All these ultrasonic parameters were quantified, added, and arrived at ultrasonography comprehensive scores.To use surgical pathology as the gold standard, the sensitivity, specificity, accuracy of Doppler Ultrasound, elasticity score and strain ratio methods and ultrasonography comprehensive scoring method were comparatively analyzed. Results: (1) The sensitivity, specificity, and accuracy of Doppler Ultrasound in diagnosing cervical lesions were 82.89% (63/76), 85.0% (34/40), and 83.62% (97/116), respectively.(2) The sensitivity, specificity, and accuracy of the elasticity score method were 77.63% (59/76), 82.5% (33/40), and 79.31% (92/116), respectively; the sensitivity, specificity, and accuracy of the strain ratio measure method were 84.21% (64/76), 87.5% (35/40), and 85.34% (99/116), respectively.(3) The sensitivity, specificity, and accuracy of ultrasonography comprehensive scoring method were 90.79% (69/76), 92.5% (37/40), and 91.38% (106/116), respectively. Conclusion: (1) It was obvious that ultrasonic elastography had certain diagnostic value in cervical lesions. Strain ratio measurement can be more objective than elasticity score method.(2) The combined application of ultrasonography comprehensive scoring method, ultrasonic elastography and conventional sonography was more accurate than single parameter.

Down-regulation of FcεRI-mediated CD63 basophil response during short-term VIT determined venom-nonspecific desensitization.

PubMed

Čelesnik Smodiš, Nina; Šilar, Mira; Eržen, Renato; Rijavec, Matija; Košnik, Mitja; Korošec, Peter

2014-01-01

We recently showed a desensitization of FcεRI-mediated basophil response after short-term VIT. Our aim was to evaluate the allergen specificity of this desensitization. In 11 Hymenoptera-venom double positive subjects, basophil threshold sensitivity (CD-sens) to anti-FcεRI, honeybee, and Vespula venom was assessed at the beginning and just before the first maintenance dose (MD) of single ultra-rush VIT. In some patients we also monitored CD-sens to rApi m 1 and/or rVes v 5 or other co-sensitizations (i.e., grass pollen). In additional 7 patients, basophils were stripped and sensitized with house dust mite (HDM) IgEs at the same time points. We demonstrated a marked reduction of CD-sens to anti-FcεRI and VIT-specific venom before the first MD in all 18 subjects included. Furthermore, in 10 out of 11 double positive subjects, a significant and comparable decrease before the first MD was also evident for non-VIT venom; this nonspecific decrease was further supported by the opposite recombinant species-specific major allergen. In one subject with additional grass pollen allergy, a decrease of CD-sens to grass allergen was also demonstrated. Similarly, in 7 cases of patients with passively HDM-sensitized basophils, a significant reduction of CD-sens was also evident to de novo sensitized HDM allergen. Short-term VIT induced basophil desensitization to VIT-specific as well as to VIT-nonspecific venom. As opposed to long-term VIT, which induces venom-specific changes, the effect of short-term VIT seems to be venom-nonspecific.

Down-Regulation of FcεRI-Mediated CD63 Basophil Response during Short-Term VIT Determined Venom-Nonspecific Desensitization

PubMed Central

Čelesnik Smodiš, Nina; Šilar, Mira; Eržen, Renato; Rijavec, Matija; Košnik, Mitja; Korošec, Peter

2014-01-01

Background We recently showed a desensitization of FcεRI-mediated basophil response after short-term VIT. Our aim was to evaluate the allergen specificity of this desensitization. Methods In 11 Hymenoptera-venom double positive subjects, basophil threshold sensitivity (CD-sens) to anti-FcεRI, honeybee, and Vespula venom was assessed at the beginning and just before the first maintenance dose (MD) of single ultra-rush VIT. In some patients we also monitored CD-sens to rApi m 1 and/or rVes v 5 or other co-sensitizations (i.e., grass pollen). In additional 7 patients, basophils were stripped and sensitized with house dust mite (HDM) IgEs at the same time points. Results We demonstrated a marked reduction of CD-sens to anti-FcεRI and VIT-specific venom before the first MD in all 18 subjects included. Furthermore, in 10 out of 11 double positive subjects, a significant and comparable decrease before the first MD was also evident for non-VIT venom; this nonspecific decrease was further supported by the opposite recombinant species-specific major allergen. In one subject with additional grass pollen allergy, a decrease of CD-sens to grass allergen was also demonstrated. Similarly, in 7 cases of patients with passively HDM-sensitized basophils, a significant reduction of CD-sens was also evident to de novo sensitized HDM allergen. Conclusions Short-term VIT induced basophil desensitization to VIT-specific as well as to VIT-nonspecific venom. As opposed to long-term VIT, which induces venom-specific changes, the effect of short-term VIT seems to be venom-nonspecific. PMID:24733549

Diagnostic value of sleep stage dissociation as visualized on a 2-dimensional sleep state space in human narcolepsy.

PubMed

Olsen, Anders Vinther; Stephansen, Jens; Leary, Eileen; Peppard, Paul E; Sheungshul, Hong; Jennum, Poul Jørgen; Sorensen, Helge; Mignot, Emmanuel

2017-04-15

Type 1 narcolepsy (NT1) is characterized by symptoms believed to represent Rapid Eye Movement (REM) sleep stage dissociations, occurrences where features of wake and REM sleep are intermingled, resulting in a mixed state. We hypothesized that sleep stage dissociations can be objectively detected through the analysis of nocturnal Polysomnography (PSG) data, and that those affecting REM sleep can be used as a diagnostic feature for narcolepsy. A Linear Discriminant Analysis (LDA) model using 38 features extracted from EOG, EMG and EEG was used in control subjects to select features differentiating wake, stage N1, N2, N3 and REM sleep. Sleep stage differentiation was next represented in a 2D projection. Features characteristic of sleep stage differences were estimated from the residual sleep stage probability in the 2D space. Using this model we evaluated PSG data from NT1 and non-narcoleptic subjects. An LDA classifier was used to determine the best separation plane. This method replicates the specificity/sensitivity from the training set to the validation set better than many other methods. Eight prominent features could differentiate narcolepsy and controls in the validation dataset. Using a composite measure and a specificity cut off 95% in the training dataset, sensitivity was 43%. Specificity/sensitivity was 94%/38% in the validation set. Using hypersomnia subjects, specificity/sensitivity was 84%/15%. Analyzing treated narcoleptics the specificity/sensitivity was 94%/10%. Sleep stage dissociation can be used for the diagnosis of narcolepsy. However the use of some medications and presence of undiagnosed hypersomnolence patients impacts the result. Copyright © 2017 Elsevier B.V. All rights reserved.

Posturography and locomotor tests of dynamic balance after long-duration spaceflight.

PubMed

Cohen, Helen S; Kimball, Kay T; Mulavara, Ajitkumar P; Bloomberg, Jacob J; Paloski, William H

2012-01-01

The currently approved objective clinical measure of standing balance in astronauts after space flight is the Sensory Organization Test battery of computerized dynamic posturography. No tests of walking balance are currently approved for standard clinical testing of astronauts. This study determined the sensitivity and specificity of standing and walking balance tests for astronauts before and after long-duration space flight. Astronauts were tested on an obstacle avoidance test known as the Functional Mobility Test (FMT) and on the Sensory Organization Test using sway-referenced support surface motion with eyes closed (SOT 5) before and six months after (n=15) space flight on the International Space Station. They were tested two to seven days after landing. Scores on SOT tests decreased and scores on FMT increased significantly from pre- to post-flight. In other words, post-flight scores were worse than pre-flight scores. SOT and FMT scores were not significantly related. ROC analyses indicated supra-clinical cut-points for SOT 5 and for FMT. The standard clinical cut-point for SOT 5 had low sensitivity to post-flight astronauts. Higher cut-points increased sensitivity to post-flight astronauts but decreased specificity to pre-flight astronauts. Using an FMT cut-point that was moderately highly sensitive and highly specific plus SOT 5 at the standard clinical cut-point was no more sensitive than SOT 5, alone. FMT plus SOT 5 at higher cut-points was more specific and more sensitive. The total correctly classified was highest for FMT, alone, and for FMT plus SOT 5 at the highest cut-point. These findings indicate that standard clinical comparisons are not useful for identifying problems. Testing both standing and walking balance will be more likely to identify balance deficits.

Can magnetic resonance imaging at 3.0-Tesla reliably detect patients with endometriosis? Initial results.

PubMed

Thomeer, Maarten G; Steensma, Anneke B; van Santbrink, Evert J; Willemssen, Francois E; Wielopolski, Piotr A; Hunink, Myriam G; Spronk, Sandra; Laven, Joop S; Krestin, Gabriel P

2014-04-01

The aim of this study was to determine whether an optimized 3.0-Tesla magnetic resonance imaging (MRI) protocol is sensitive and specific enough to detect patients with endometriosis. This was a prospective cohort study with consecutive patients. Forty consecutive patients with clinical suspicion of endometriosis underwent 3.0-Tesla MRI, including a T2-weighted high-resolution fast spin echo sequence (spatial resolution=0.75 ×1.2 ×1.5 mm³) and a 3D T1-weighted high-resolution gradient echo sequence (spatial resolution=0.75 ×1.2 × 2.0 mm³). Two radiologists reviewed the dataset with consensus reading. During laparoscopy, which was used as reference standard, all lesions were characterized according to the revised criteria of the American Fertility Society. Patient-level and region-level sensitivities and specificities and lesion-level sensitivities were calculated. Patient-level sensitivity was 42% for stage I (5/12) and 100% for stages II, III and IV (25/25). Patient-level specificity for all stages was 100% (3/3). The region-level sensitivity and specificity was 63% and 97%, respectively. The sensitivity per lesion was 61% (90% for deep lesions, 48% for superficial lesions and 100% for endometriomata). The detection rate of obliteration of the cul-the-sac was 100% (10/10) with no false positive findings. The interreader agreement was substantial to perfect (kappa=1 per patient, 0.65 per lesion and 0.71 for obliteration of the cul-the-sac). An optimized 3.0-Tesla MRI protocol is accurate in detecting stage II to stage IV endometriosis. © 2014 The Authors. Journal of Obstetrics and Gynaecology Research © 2014 Japan Society of Obstetrics and Gynecology.

Single-energy non-contrast hepatic steatosis criteria applied to virtual non-contrast images: is it still highly specific and positively predictive?

PubMed

Haji-Momenian, S; Parkinson, W; Khati, N; Brindle, K; Earls, J; Zeman, R K

2018-06-01

To determine the sensitivity, specificity, and predictive values of single-energy non-contrast hepatic steatosis criteria on dual-energy virtual non-contrast (VNC) images. Forty-eight computed tomography (CT) examinations, which included single-energy non-contrast (TNC) and contrast-enhanced dual-energy CT angiography (CTA) of the abdomen, were enrolled. VNC images were reconstructed from the CTA. Region of interest (ROI) attenuations were measured in the right and left hepatic lobes, spleen, and aorta on TNC and VNC images. The right and left hepatic lobes were treated as separate samples. Steatosis was diagnosed based on TNC liver attenuation of ≤40 HU or liver attenuation index (LAI) of ≤-10 HU, which are extremely specific and predictive for moderate to severe steatosis. The sensitivity, specificity, and predictive values of VNC images for steatosis were calculated. VNC-TNC deviations were correlated with aortic enhancement and patient water equivalent diameter (PWED). Thirty-two liver ROIs met steatosis criteria based on TNC attenuation; VNC attenuation had sensitivity, specificity, and a positive predictive value of 66.7%, 100%, and 100%, respectively. Twenty-one liver ROIs met steatosis criteria based on TNC LAI. VNC LAI had sensitivity, specificity, and positive predictive values of 61.9%, 90.7%, and 65%, respectively. Hepatic and splenic VNC-TNC deviations did not correlate with one another (R 2 =0.08), aortic enhancement (R 2 <0.06) or PWED (R 2 <0.09). Non-contrast hepatic attenuation criteria is extremely specific and positively predictive for moderate to severe steatosis on VNC reconstructions from the arterial phase. Hepatic attenuation performs better than LAI criteria. VNC deviations are independent of aortic enhancement and PWED. Copyright © 2018 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Sensitive and Specific Guest Recognition through Pyridinium-Modification in Spindle-Like Coordination Containers.

PubMed

Bhuvaneswari, Nagarajan; Dai, Feng-Rong; Chen, Zhong-Ning

2018-05-02

An elaborately designed pyridinium-functionalized octanuclear zinc(II) coordination container 1-Zn was prepared through the self-assembly of Zn 2+ , p-tert-butylsulfonylcalix[4]arene, and pyridinium-functionalized angular flexible dicarboxylate linker (H 2 BrL1). The structure was determined by a single-crystal X-ray diffractometer. 1-Zn displays highly sensitive and specific recognition to 2-picolylamine as revealed by drastic blueshifts of the absorption and emission spectra, ascribed to the decrease of intramolecular charge transfer (ICT) character of the container and the occurrence of intermolecular charge transfer between the host and guest molecules. The intramolecular charge transfer plays a key role in the modulation of the electronic properties and is tunable through endo-encapsulation of specific guest molecules. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Diagnostic Accuracy of the FIGO and the 5-Tier Fetal Heart Rate Classification Systems in the Detection of Neonatal Acidemia.

PubMed

Martí Gamboa, Sabina; Giménez, Olga Redrado; Mancho, Jara Pascual; Moros, María Lapresta; Sada, Julia Ruiz; Mateo, Sergio Castan

2017-04-01

Objective  The objective of this study was to determine ability to detect neonatal acidemia and interobserver agreement with the FIGO 3-tier and 5-tier fetal heart rate (FHR) classification systems. Design  This was a case-control study. Setting  This study was set at the University Medical Center. Population  A total of 202 FHR tracings of 102 women who delivered an acidemic fetus (umbilical arterial cord gas pH ≤ 7.10 and BE < - 8) and 100 who delivered a nonacidemic fetus (umbilical arterial cord gas pH > 7.10) were assessed. A subanalysis was performed for those fetuses who suffered severe metabolic acidemia (pH ≤ 7.0 and BE < - 12). Methods  Two reviewers blind to clinical and outcome data classified tracings according to the new 3-tier system proposed by the FIGO and the 5-tier system proposed by Parer and Ikeda. Main Outcome Measures  Sensitivity and specificity for detecting neonatal acidemia and interobserver agreement in classifying FHR tracings into categories of both systems were studied. Results  The 3-tier system showed a greater sensitivity and lower specificity to detect neonatal acidemia (43.6% sensitivity, 82.5% specificity) and severe metabolic acidemia (71.4% sensitivity, 74.0% specificity) compared with the 5-tier system (36.3% sensitivity, 88% specificity and 61.9% sensitivity, 80.1% specificity, respectively). Both systems were compared by area under the receiver-operating characteristic curve, with comparable predictive ability for detecting neonatal acidemia (FIGO-area under the curve [AUC]: 0.63 [95% confidence interval [CI]: 0.57-0.68] and Parer-AUC: 0.62 [95% CI: 0.56-0.67]). Interobserver agreement was moderate for both systems, but performance at each specific category showed a better agreement for the 5-tier system identifying a pathological tracing (orange or red, κ: 0.625 vs. pathological category, κ: 0.538). Conclusion  Both systems presented a comparable ability to predict neonatal acidemia, although the 5-tier system showed a better interobserver agreement identifying pathological tracings. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The diagnostic validity of musculoskeletal ultrasound in lateral epicondylalgia: a systematic review.

PubMed

Dones, Valentin C; Grimmer, Karen; Thoirs, Kerry; Suarez, Consuelo G; Luker, Julie

2014-03-03

Ultrasound is considered a reliable, widely available, non-invasive and inexpensive imaging technique for assessing soft tissue involvement in Lateral epicondylalgia. Despite the number of diagnostic studies for Lateral Epicondylalgia, there is no consensus in the current literature on the best abnormal ultrasound findings that confirm lateral epicondylalgia. Eligible studies identified by searching electronic databases, scanning reference lists of articles and chapters on ultrasound in reference books, and consultation of experts in sonography. Three reviewers (VCDIII, KP, KW) independently searched the databases using the agreed search strategy, and independently conducted all stages of article selection. Two reviewers (VCDIII, KP) then screened titles and abstracts to remove obvious irrelevance. Potentially relevant full text publications which met the inclusion criteria were reviewed by the primary investigator (VCDIII) and another reviewer (CGS). Among the 15 included diagnostic studies in this review, seven were Level II diagnostic accuracy studies for chronic lateral epicondylalgia based on the National Health and Medical Research Council Hierarchy of Evidence. Based from the pooled sensitivity of abnormal ultrasound findings with homogenous results (p > 0.05), the hypoechogenicity of the common extensor origin has the best combination of diagnostic sensitivity and specificity. It is moderately sensitive [Sensitivity: 0.64 (0.56-0.72)] and highly specific [Specificity: 0.82 (0.72-0.90)] in determining elbows with lateral epicondylalgia. Additionally, bone changes on the lateral epicondyle [Sensitivity: 0.56 (0.50-0.62)] were moderately sensitive to chronic LE. Conversely, neovascularity [Specificity: 1.00 (0.97-1.00)], calcifications [Specificity: 0.97 (0.94-0.99)] and cortical irregularities [Specificity: 0.96 (0.88-0.99)] have strong specificity for chronic lateral epicondylalgia. There is insufficient evidence supporting the use of Power Doppler Ultrasonogrophy, Real-time Sonoelastography and sonographic probe-induced tenderness in diagnosing LE. The use of Gray-scale Ultrasonography is recommended in objectively diagnosing lateral epicondylalgia. The presence of hypoechogenicity and bone changes indicates presence of a stressed common extensor origin-lateral epicondyle complex in elbows with lateral epicondylalgia. In addition to diagnosis, detection of these abnormal ultrasound findings allows localization of pathologies to tendon or bone that would assist in designing an appropriate treatment suited to patient's condition.

A Sensitive and Specific Diagnostic Panel to Distinguish Diffuse Astrocytoma from Astrocytosis: Chromosome 7 Gain with Mutant Isocitrate Dehydrogenase 1 and p53

PubMed Central

Camelo-Piragua, Sandra; Jansen, Michael; Ganguly, Aniruddha; Kim, J. ChulMin; Cosper, Arjola K.; Dias-Santagata, Dora; Nutt, Catherine L.; Iafrate, A. John; Louis, David N.

2011-01-01

One of the major challenges of surgical neuropathology is the distinction of diffuse astrocytoma (World Health Organization [WHO] grade II) from astrocytosis. The most commonly used ancillary tool to solve this problem is p53 immunohistochemistry (IHC), but this is neither sensitive nor specific. Isocitrate dehydrogenase 1 (IDH1) mutations are common in lower grade gliomas, with most causing a specific amino acid change (R132H) that can be detected with a monoclonal antibody. IDH2 mutations are rare, but also occur in gliomas. In addition, gains of chromosome 7 are common in gliomas. In this study we assessed the status of p53, IDH1/2 and chromosome 7 to determine the most useful panel to distinguish astrocytoma from astrocytosis. We studied biopsy specimens from 21 WHO grade II diffuse astrocytomas and 20 reactive conditions. The single most sensitive test to identify astrocytoma is fluorescence in situ hybridization (FISH) for chromosome 7 gain (76.2%). The combination of p53 and mutant IDH1 IHC provides a higher sensitivity (71.4%) than either test alone (47.8%); this combination offers a practical initial approach for the surgical pathologist. The best overall sensitivity (95%) is achieved when FISH for chromosome 7 gain is added to the p53-mutant IDH1 IHC panel. PMID:21343879

Nanoamplifiers synthesized from gadolinium and gold nanocomposites for magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Tian, Xiumei; Shao, Yuanzhi; He, Haoqiang; Liu, Huan; Shen, Yingying; Huang, Wenlin; Li, Li

2013-03-01

We have synthesized an efficient and highly sensitive nanoamplifier composed of gadolinium-doped silica nanoparticles and gold nanoparticles (AuNPs). Magnetic resonance imaging (MRI) in vitro and in vivo assays revealed enhancement of signal sensitivity, which may be explained by electron transfer between water and gadolinium-doped nanoparticles, apparent in the presence of gold. In vitro and in vivo evaluation demonstrated nanoamplifier incurred minimal cytotoxicity and immunotoxicity, increased stability, and gradual excretion patterns. Tumor targeted properties were preliminarily determined when the nanoamplifier was injected into mouse models of colon cancer liver metastasis. Furthermore, although AuNPs departed from the nanoamplifiers in specific mice tissues, optical and magnetic resonance imaging was efficient, especially in metastatic tumors. These assays validate our nanoamplifier as an effective MRI signal enhancer with sensitive cancer diagnosis potential.We have synthesized an efficient and highly sensitive nanoamplifier composed of gadolinium-doped silica nanoparticles and gold nanoparticles (AuNPs). Magnetic resonance imaging (MRI) in vitro and in vivo assays revealed enhancement of signal sensitivity, which may be explained by electron transfer between water and gadolinium-doped nanoparticles, apparent in the presence of gold. In vitro and in vivo evaluation demonstrated nanoamplifier incurred minimal cytotoxicity and immunotoxicity, increased stability, and gradual excretion patterns. Tumor targeted properties were preliminarily determined when the nanoamplifier was injected into mouse models of colon cancer liver metastasis. Furthermore, although AuNPs departed from the nanoamplifiers in specific mice tissues, optical and magnetic resonance imaging was efficient, especially in metastatic tumors. These assays validate our nanoamplifier as an effective MRI signal enhancer with sensitive cancer diagnosis potential. Electronic supplementary information (ESI) available: Protocols for the characterization, immunotoxicity and pharmacokinetics analyses. Additional supporting figures. See DOI: 10.1039/c3nr00170a

Differential gene expression responses distinguish contact and respiratory sensitizers and nonsensitizing irritants in the local lymph node assay.

PubMed

Adenuga, David; Woolhiser, Michael R; Gollapudi, B Bhaskar; Boverhof, Darrell R

2012-04-01

Genomic approaches have the potential to enhance the specificity and predictive accuracy of existing toxicology endpoints, including those for chemical sensitization. The present study was conducted to determine whether gene expression responses can distinguish contact sensitizers (1-chloro-2,4-dinitrobenzene [DNCB] and hexyl cinnamic aldehyde [HCA]), respiratory sensitizers (ortho-phthalaldehyde and trimellitic anhydride [TMA]), and nonsensitizing irritants (methyl salicylate [MS] and nonanoic acid [NA]) in the local lymph node assay (LLNA). Female Balb/c mice received doses of each chemical as per the standard LLNA dosing regimen on days 1, 2, and 3. Auricular lymph nodes were analyzed for tritiated thymidine ((3)HTdR) incorporation on day 6 and for gene expression responses on days 6 and 10. All chemicals induced dose-dependent increases in stimulation index, which correlated strongly with the number of differentially expressed genes. A majority of genes modulated by the irritants were similarly altered by the sensitizers, consistent with the irritating effects of the sensitizers. However, a select number of responses involved with immune-specific functions, such as dendritic cell activation, were unique to the sensitizers and may offer the ability to distinguish sensitizers from irritants. Genes for the mast cell proteases 1 and 8, Lgals7, Tim2, Aicda, Il4, and Akr1c18 were more strongly regulated by respiratory sensitizers compared with contact sensitizers and may represent potential biomarkers for discriminating between contact and respiratory sensitizers. Collectively, these data suggest that gene expression responses may serve as useful biomarkers to distinguish between respiratory and contact sensitizers and nonsensitizing irritants in the LLNA.

Comparison of ferumoxytol-enhanced MRA with conventional angiography for assessment of severity of transplant renal artery stenosis.

PubMed

Fananapazir, Ghaneh; Bashir, Mustafa R; Corwin, Michael T; Lamba, Ramit; Vu, Catherine T; Troppmann, Christoph

2017-03-01

To determine the accuracy of ferumoxytol-enhanced magnetic resonance angiography (MRA) in assessing the severity of transplant renal artery stenosis (TRAS), using digital subtraction angiography (DSA) as the reference standard. Our Institutional Review Board approved this retrospective, Health Insurance Portability and Accountability Act-compliant study. Thirty-three patients with documented clinical suspicion for TRAS (elevated serum creatinine, refractory hypertension, edema, and/or audible bruit) and/or concerning sonographic findings (elevated renal artery velocity and/or intraparenchymal parvus tardus waveforms) underwent a 1.5T MRA with ferumoxytol prior to DSA. All DSAs were independently reviewed by an interventional radiologist and served as the reference standard. The MRAs were reviewed by three readers who were blinded to the ultrasound and DSA findings for the presence and severity of TRAS. Sensitivity, specificity, and accuracy for identifying substantial stenoses (>50%) were determined. Intraclass correlation coefficients (ICCs) were calculated among readers. Mean differences between the percent stenosis from each MRA reader and DSA were calculated. On DSA, a total of 42 stenoses were identified in the 33 patients. The sensitivity, specificity, and accuracy of MRA in detecting substantial stenoses were 100%, 75-87.5%, and 95.2-97.6%, respectively, among the readers. There was excellent agreement among readers as to the percent stenosis (ICC = 0.82). MRA overestimated the degree of stenosis by 3.9-9.6% compared to DSA. Ferumoxytol-enhanced MRA provides high sensitivity, specificity, and accuracy for determining the severity of TRAS. Our results suggest that it can potentially be used as a noninvasive examination following ultrasound to reduce the number of unnecessary conventional angiograms. 3 J. Magn. Reson. Imaging 2017;45:779-785. © 2016 International Society for Magnetic Resonance in Medicine.

Bronchial and non-bronchial systemic arteries: value of multidetector CT angiography in diagnosis and angiographic embolisation feasibility analysis.

PubMed

Lin, Yuning; Chen, Ziqian; Yang, Xizhang; Zhong, Qun; Zhang, Hongwen; Yang, Li; Xu, Shangwen; Li, Hui

2013-12-01

The aim of this study is to evaluate the diagnostic performance of multidetector CT angiography (CTA) in depicting bronchial and non-bronchial systemic arteries in patients with haemoptysis and to assess whether this modality helps determine the feasibility of angiographic embolisation. Fifty-two patients with haemoptysis between January 2010 and July 2011 underwent both preoperative multidetector CTA and digital subtraction angiography (DSA) imaging. Diagnostic performance of CTA in depicting arteries causing haemoptysis was assessed on a per-patient and a per-artery basis. The feasibility of the endovascular treatment evaluated by CTA was analysed. Sensitivity, specificity, and positive and negative predictive values for those analyses were determined. Fifty patients were included in the artery-presence-number analysis. In the per-patient analysis, neither CTA (P = 0.25) nor DSA (P = 1.00) showed statistical difference in the detection of arteries causing haemoptysis. The sensitivity, specificity, and positive and negative predictive values were 94%, 100%, 100%, and 40%, respectively, for the presence of pathologic arteries evaluated by CTA, and 98%, 100%, 100%, and 67%, respectively, for DSA. On the per-artery basis, CTA correctly identified 97% (107/110). Fifty-two patients were included in the feasibility analysis. The performance of CTA in predicting the feasibility of angiographic embolisation was not statistically different from the treatment performed (P = 1.00). The sensitivity, specificity, and positive and negative predictive values were 96%, 80%, 98% and 67%, respectively, for CTA. Multidetector CTA is an accurate imaging method in depicting the presence and number of arteries causing haemoptysis. This modality is also useful for determining the feasibility of angiographic embolisation for haemoptysis. © 2013 The Authors. Journal of Medical Imaging and Radiation Oncology © 2013 The Royal Australian and New Zealand College of Radiologists.

Identification of Streptococcus agalactiae by fluorescent in situ hybridization compared to culturing and the determination of prevalence of Streptococcus agalactiae colonization among pregnant women in Bushehr, Iran.

PubMed

Tajbakhsh, Saeed; Norouzi Esfahani, Marjan; Emaneini, Mohammad; Motamed, Niloofar; Rahmani, Elham; Gharibi, Somayyeh

2013-09-08

Pregnant women colonized by Streptococcus agalactiae (group B streptococci [GBS]) may transfer this microorganism to their newborns. S. agalactiae is an important cause of pneumonia, sepsis, and meningitis in newborns. Fluorescent in situ hybridization (FISH) is considered as a method of identification in the field of diagnostic microbiology. In this paper, we have designed a study to compare the DNA FISH after 7 h Lim broth enrichment and culturing for the identification of S. agalactiae and to determine the prevalence of vaginal colonization by S. agalactiae among pregnant women in Bushehr, Iran. Vaginal swab specimens were obtained from 285 pregnant women at 35 weeks or more than 35 weeks of gestation. The specimens were inoculated into Lim broth. In order to evaluate the sensitivity and specificity of GBS DNA FISH after 7 h Lim broth enrichment, the specimens were tested using both FISH and conventional culture methods. In addition, the prevalence of GBS colonization was determined. Based on the results of this study, both the sensitivity and specificity of FISH were 100%. S. agalactiae was detected by both culture and FISH in 27 of the 285 pregnant women. Thus, the prevalence of GBS colonization was 9.5%. Since short-term (7 h) Lim broth enrichment followed by FISH using oligonucleotide probes showed a high sensitivity and specificity, this protocol is therefore a highly accurate and relatively rapid method for the detection of S. agalactiae. Our analysis suggests that the use of DNA FISH to screen for S. agalactiae colonization in pregnant women may be considered in the absence of GBS culture availability.

Diagnostic accuracy of the Thessaly test, standardised clinical history and other clinical examination tests (Apley's, McMurray's and joint line tenderness) for meniscal tears in comparison with magnetic resonance imaging diagnosis.

PubMed

Blyth, Mark; Anthony, Iain; Francq, Bernard; Brooksbank, Katriona; Downie, Paul; Powell, Andrew; Jones, Bryn; MacLean, Angus; McConnachie, Alex; Norrie, John

2015-08-01

Reliable non-invasive diagnosis of meniscal tears is difficult. Magnetic resonance imaging (MRI) is often used but is expensive and incidental findings are problematic. There are a number of physical examination tests for the diagnosis of meniscal tears that are simple, cheap and non-invasive. To determine the diagnostic accuracy of the Thessaly test and to determine if the Thessaly test (alone or in combination with other physical tests) can obviate the need for further investigation by MRI or arthroscopy for patients with a suspected meniscal tear. Single-centre prospective diagnostic accuracy study. Although the study was performed in a secondary care setting, it was designed to replicate the results that would have been achieved in a primary care setting. Two cohorts of patients were recruited: patients with knee pathology (n = 292) and a control cohort with no knee pathology (n = 75). Sensitivity, specificity and diagnostic accuracy of the Thessaly test in determining the presence of meniscal tears. Participants were assessed by both a primary care clinician and a musculoskeletal clinician. Both clinicians performed the Thessaly test, McMurray's test, Apley's test, joint line tenderness test and took a standardised clinical history from the patient. The Thessaly test had a sensitivity of 0.66, a specificity of 0.39 and a diagnostic accuracy of 54% when utilised by primary care clinicians. This compared with a sensitivity of 0.62, a specificity of 0.55 and diagnostic accuracy of 59% when used by musculoskeletal clinicians. The diagnostics accuracy of the other tests when used by primary care clinicians was 54% for McMurray's test, 53% for Apley's test, 54% for the joint line tenderness test and 55% for clinical history. For primary care clinicians, age and past history of osteoarthritis were both significant predictors of MRI diagnosis of meniscal tears. For musculoskeletal clinicians age and a positive diagnosis of meniscal tears on clinical history taking were significant predictors of MRI diagnosis. No physical tests were significant predictors of MRI diagnosis in our multivariate models. The specificity of MRI diagnosis was tested in subgroup of patients who went on to have a knee arthroscopy and was found to be low [0.53 (95% confidence interval 0.28 to 0.77)], although the sensitivity was 1.0. The Thessaly test was no better at diagnosing meniscal tears than other established physical tests. The sensitivity, specificity and diagnostic accuracy of all physical tests was too low to be of routine clinical value as an alternative to MRI. Caution needs to be exercised in the indiscriminate use of MRI scanning in the identification of meniscal tears in the diagnosis of the painful knee, due to the low specificity seen in the presence of concomitant knee pathology. Further research is required to determine the true diagnostic accuracy and cost-effectiveness of MRI for the detection of meniscal tears. Current Controlled Trial ISRCTN43527822. The National Institute for Health Research Health Technology Assessment programme.

Neuroendocrine tumor recurrence: diagnosis with 68Ga-DOTATATE PET/CT.

PubMed

Haug, Alexander R; Cindea-Drimus, Ramona; Auernhammer, Christoph J; Reincke, Martin; Beuschlein, Felix; Wängler, Björn; Uebleis, Christopher; Schmidt, Gerwin P; Spitzweg, Christine; Bartenstein, Peter; Hacker, Marcus

2014-02-01

To evaluate diagnostic performance of gallium 68-tetraazacyclododecane tetraacetic acid-octreotate ((68)Ga-DOTATATE) in detection of recurrent neuroendocrine tumors (NETs). Approval was waived by the local ethics committee for this retrospective study. Between 2007 and 2011, 63 patients (mean age, 58 years) were examined with (68)Ga-DOTATATE positron emission tomography (PET)/computed tomography (CT) after primary NET curative resection. Reasons for PET/CT were regular follow-up examinations (n = 30), increased plasma levels of tumor markers (n = 27), or clinical suspicion of recurrence (n = 6). Final diagnosis was determined with histopathologic verification (n = 25) or clinical follow-up (n = 38). PET/CT scans were evaluated in consensus by two readers without blinding to clinical information and independently by two readers with blinding. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. Final diagnosis of NET recurrence was determined in 29 patients. In three other patients, tumors of nonneuroendocrine origin were diagnosed. (68)Ga-DOTATATE PET/CT helped identify NET recurrence in 26 of 29 patients (sensitivity, 90%) and exclude presence of recurrent NET in 28 of 34 patients (specificity, 82% ). PET/CT provided false-positive and false-negative results in six and three patients (PPV, 81% [26 of 32]; NPV, 90% [28 of 31]; accuracy, 86% [54 of 63]). In gastroenteropancreatic NET (n = 45), sensitivity was 94% (17 of 18); specificity was 89% (24 of 27); PPV was 85% (17 of 20); NPV was 96% (24 of 25); and accuracy was 91% (41 of 45). Two blinded readers achieved sensitivity of 79% (23 of 29) and 76% (22 of 29); specificity of 85% (29 of 34) and 94% (32 of 34) (κ = 0.80); and accuracy of 83% and 86%. (68)Ga-DOTATATE PET/CT is accurate in detection of recurrent NET. Blinded PET/CT review markedly decreased sensitivity, underlining importance of considering clinical parameters in NET recurrence. Present results must be further validated to substantiate use of (68)Ga-DOTATATE PET/CT in routine follow-up after curative resection of NET. © RSNA, 2013

[Assessment Method of Remnant α-1, 3-galactosyle Epitopes in Animal Tissue-derived Biomaterials].

PubMed

Shan, Yongqiang; Xu, Liming; Ke, Linnan; Lu, Yan; Shao, Anliang; Zhang, Na; Zeng, Bixin

2015-06-01

The aim of this study was to establish an assessment method for determining α-Gal (α-1, 3-galactosyle) epitopes contained in animal tissue or animal tissue-derived biological materials with ELISA inhibition assay. Firstly, a 96 well plate was coated with Gal α-1, 3-Gal/bovine serum albumin (BSA) as a solid phase antigen and meanwhile, the anti-α-Gal M86 was used to react with α-Gal antigens which contained in the test materials. Then, the residual antibodies (M86) in the supernatant of M86-Gal reaction mixture were measured using ELISA inhibition assay by the α-Gal coating plate. The inhibition curve of the ELISA inhibition assay, the R2 = 0.999, was well established. Checking using both α-Gal positive materials (rat liver tissues) and α-Gal negative materials (human placenta tissues) showed a good sensitivity and specificity. Based on the presently established method, the α-Gal expression profile of rat tissues, decellular animal tissue-derived biological materials and porcine dermal before and after decellular treatment were determined. The M86 ELISA inhibition assay method, which can quantitatively determine the α-Gal antigens contained in animal tissues or animal tissue-derived biomaterials, was refined. This M86 specific antibody based-ELISA inhibition assay established in the present study has good sensitivity and specificity, and could be a useful method for determining remnant α-1, 3Gal antigens in animal tissue-derived biomaterials.

The role of nerve monitoring to predict postoperative recurrent laryngeal nerve function in thyroid and parathyroid surgery.

PubMed

Eid, Issam; Miller, Frank R; Rowan, Stephanie; Otto, Randal A

2013-10-01

To determine the role and efficacy of intraoperative recurrent laryngeal nerve (RLN) stimulation in the prediction of early and permanent postoperative nerve function in thyroid and parathyroid surgery. A retrospective review of thyroid and parathyroid surgeries was performed with calculation of sensitivity and specificity of the response of intraoperative stimulation for different pathological groups. Normal electromyography (EMG) response with 0.5 mAmp stimulation was considered a positive stimulation response with postoperative function determined by laryngoscopy. No EMG response at >1-2 mAmps was considered a negative response. The rates of early and permanent paralysis, as well as sensitivity, specificity, and positive and negative predictive values for postoperative nerve function were calculated for separate pathological groups. The number of nerves at risk analyzed was 909. The overall early and permanent paralysis rates were 3.1% and 1.2%, respectively, with the highest rate being for Grave's disease cases. The overall sensitivity was 98.4%. The specificity was lower at 62.5% but acceptable in thyroid carcinoma and Grave's disease patients. The majority of nerves with a positive stimulation result and postoperative paralysis on laryngoscopy recovered function in 3 to 12 weeks, showing positive stimulation to be a good predictor of eventual recovery. Stimulation of the RLN during thyroid and parathyroid surgery is a useful tool in predicting postoperative RLN function. The sensitivity of stimulation is high, showing positive stimulation to be an excellent predictor of normal nerve function. Negative stimulation is more predictive of paralysis in cases of thyroid carcinoma and Grave's disease. 2b. Copyright © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Predicting gestational diabetes mellitus during the first trimester using anthropometric measurements and HOMA-IR.

PubMed

Alptekin, Hüsnü; Çizmecioğlu, Ahmet; Işık, Hatice; Cengiz, Türkan; Yildiz, Murat; Iyisoy, Mehmet Sinan

2016-05-01

To determine the predictability of gestational diabetes mellitus (GDM) during the first trimester using the degree of insulin resistance and anthropometric measurements and to assign the risk of developing GDM by weight gained during pregnancy (WGDP). A total of 250 singleton pregnancies at 7-12 gestational weeks were studied. Body mass index (BMI), waist/hip ratio (WHR), quantitative insulin sensitivity check index (QUICKI), homeostasis model assessment-insulin resistance (HOMA-IR) scores and WGDP were determined. The backward stepwise method was applied to estimate possible associations with GDM. Cutoff points were estimated using receiver operating characteristic curve analysis. GDM was found in 20 of 227 singleton pregnancies (8.8 %). The calculated HOMA-IR, QUICKI, BMI, WHR, WGDP, and parity were significantly associated with GDM. Logistic regression analyses showed that three covariates (HOMA-IR, BMI, WGDP) remained independently associated with GDM. It was calculated as OR 1.254 (95 % CI 1.006-1.563), AUC 0.809, sensitivity 90 %, specificity 61 % with cutoff = 2.08 for HOMA-IR; OR 1.157 (CI 1.045-1.281), AUC 0.723, sensitivity 80 %, specificity 58 % with cutoff = 25.95 for BMI; OR 1.221, (CI 1.085-1.374), AUC 0.654, sensitivity 80 %, specificity 46 % with cutoff = 4.7 for WGDP. Despite a HOMA-IR score of >3.1 in pregnant women, GDM was detected in only three of 29 patients (10.3 %) if WGDP was <4.7 kg at weeks 24-28. First trimester screening for GDM can be achieved based on maternal anthropometric measurements and HOMA-IR. In particular, if BMI is >25.95 kg/m(2) and the HOMA-IR score >2.08, controlling weight gain may protect against GDM.

How well do vital signs identify children with serious infections in paediatric emergency care?

PubMed

Thompson, M; Coad, N; Harnden, A; Mayon-White, R; Perera, R; Mant, D

2009-11-01

To determine whether vital signs identify children with serious infections, and to compare their diagnostic value with that of the Manchester triage score (MTS) and National Institute for Health and Clinical Excellence (NICE) traffic light system of clinical risk factors. Prospective cohort of children presenting with suspected acute infection. We recorded vital signs, level of consciousness, activity level, respiratory distress, hydration and MTS category. Paediatric assessment unit at a teaching hospital in England. 700 children (median age 3 years), of whom 357 (51.0%) were referred from primary care, 198 (28.3%) self-referrals and 116 (16.6%) emergency ambulance transfers. Just over half (383 or 54.7%) were admitted. Severity of infection categorised as serious, intermediate, minor or not infection. Children with serious or intermediate infections (n = 313) were significantly more likely than those with minor or no infection (n = 387) to have a temperature >or=39 degrees C, tachycardia, saturations 2 seconds. Having one or more of temperature >or=39 degrees C, saturations

Study on ABO and RhD blood grouping: Comparison between conventional tile method and a new solid phase method (InTec Blood Grouping Test Kit).

PubMed

Yousuf, R; Abdul Ghani, S A; Abdul Khalid, N; Leong, C F

2018-04-01

'InTec Blood Grouping Test kit' using solid-phase technology is a new method which may be used at outdoor blood donation site or at bed side as an alternative to the conventional tile method in view of its stability at room temperature and fulfilled the criteria as point of care test. This study aimed to compare the efficiency of this solid phase method (InTec Blood Grouping Test Kit) with the conventional tile method in determining the ABO and RhD blood group of healthy donors. A total of 760 voluntary donors who attended the Blood Bank, Penang Hospital or offsite blood donation campaigns from April to May 2014 were recruited. The ABO and RhD blood groups were determined by the conventional tile method and the solid phase method, in which the tube method was used as the gold standard. For ABO blood grouping, the tile method has shown 100% concordance results with the gold standard tube method, whereas the solid-phase method only showed concordance result for 754/760 samples (99.2%). Therefore, for ABO grouping, tile method has 100% sensitivity and specificity while the solid phase method has slightly lower sensitivity of 97.7% but both with good specificity of 100%. For RhD grouping, both the tile and solid phase methods have grouped one RhD positive specimen as negative each, thus giving the sensitivity and specificity of 99.9% and 100% for both methods respectively. The 'InTec Blood Grouping Test Kit' is suitable for offsite usage because of its simplicity and user friendliness. However, further improvement in adding the internal quality control may increase the test sensitivity and validity of the test results.

3D-CAM: Derivation and Validation of a 3-Minute Diagnostic Interview for CAM-defined Delirium

PubMed Central

Marcantonio, Edward R.; Ngo, Long H.; O’Connor, Margaret; Jones, Richard N.; Crane, Paul K.; Metzger, Eran D.; Inouye, Sharon K.

2015-01-01

Background Delirium is common, morbid, and costly, yet remains often unrecognized in most clinical settings. The Confusion Assessment Method (CAM) is the most widely used diagnostic algorithm, and operationalizing its features would represent a substantial advance for clinical care. Objective To derive the 3D-CAM, a new 3-minute diagnostic assessment for CAM-defined delirium, and to validate it against a clinical reference standard. Design Diagnostic test study Setting 4 general medicine units in an academic medical center Participants 201 inpatients aged ≥ 75 years old Measurements We identified 20 items that best operationalized the 4 CAM diagnostic features to create the 3D-CAM. For prospective validation, 3D-CAM assessments were administered by trained research assistants. Independently, clinicians performed an extensive assessment that included patient interviews, family interviews, and review of the medical record. These data were considered by an expert panel to determine the presence or absence of delirium and dementia (reference standard). We compared the 3D-CAM delirium determination to the reference standard in all patients and in subgroups with and without dementia. Results The 201 participants in the prospective validation study had mean age (SD) of 84 (5.5) years, and 27% had dementia. The expert panel identified delirium in 21%. Median administration time for 3D-CAM was 3 minutes (inter-quartile range: 2–5 minutes). The sensitivity [95% CI] of 3D-CAM was 95% [84%, 99%] and the specificity was 94% [90%, 97%]. The 3D-CAM performed well in patients both with dementia (sensitivity=96% [82%, 100%], specificity=86% [67%, 96%]) and without dementia (sensitivity=93% [66%, 100%], specificity=96% [91%,99%]). Limitations Limited to single center, cross-sectional, and medicine patients only Conclusion The 3D-CAM operationalizes the CAM algorithm using a 3-minute structured assessment with high sensitivity and specificity relative to a reference standard and could be an important tool for improving recognition of delirium. PMID:25329203

Performance characteristics of magnetic resonance imaging without contrast agents or sedation in pediatric appendicitis.

PubMed

Didier, Ryne A; Hopkins, Katharine L; Coakley, Fergus V; Krishnaswami, Sanjay; Spiro, David M; Foster, Bryan R

2017-09-01

Magnetic resonance imaging (MRI) has emerged as a promising modality for evaluating pediatric appendicitis. However optimal imaging protocols, including roles of contrast agents and sedation, have not been established and diagnostic criteria have not been fully evaluated. To investigate performance characteristics of rapid MRI without contrast agents or sedation in the diagnosis of pediatric appendicitis. We included patients ages 4-18 years with suspicion of appendicitis who underwent rapid MRI between October 2013 and March 2015 without contrast agent or sedation. After two-radiologist review, we determined performance characteristics of individual diagnostic criteria and aggregate diagnostic criteria by comparing MRI results to clinical outcomes. We used receiver operating characteristic (ROC) curves to determine cut-points for appendiceal diameter and wall thickness for optimization of predictive power, and we calculated area under the curve (AUC) as a measure of test accuracy. Ninety-eight MRI examinations were performed in 97 subjects. Overall, MRI had a 94% sensitivity, 95% specificity, 91% positive predictive value and 97% negative predictive value. Optimal cut-points for appendiceal diameter and wall thickness were ≥7 mm and ≥2 mm, respectively. Independently, those cut-points produced sensitivities of 91% and 84% and specificities of 84% and 43%. Presence of intraluminal fluid (30/33) or localized periappendiceal fluid (32/33) showed a significant association with acute appendicitis (P<0.01), with sensitivities of 91% and 97% and specificities of 60% and 50%. For examinations in which the appendix was not identified by one or both reviewers (23/98), the clinical outcome was negative. Rapid MRI without contrast agents or sedation is accurate for diagnosis of pediatric appendicitis when multiple diagnostic criteria are considered in aggregate. Individual diagnostic criteria including optimized cut-points of ≥7 mm for diameter and ≥2 mm for wall thickness demonstrate high sensitivities but relatively low specificities. Nonvisualization of the appendix favors a negative diagnosis.

Type 2 diabetes and cardiac autonomic neuropathy screening using dynamic pupillometry

PubMed Central

Lerner, Alana G.; Bernabé-Ortiz, Antonio; Ticse, Ray; Hernandez, Arturo; Huaylinos, Yvonne; Pinto, Miguel E.; Málaga, Germán; Checkley, William; Gilman, Robert H.; Miranda, J. Jaime

2015-01-01

Aim To determine if changes in pupillary response are useful as a screening tool for diabetes and to assess whether pupillometry is associated with cardiac autonomic neuropathy. Methods We conducted a cross-sectional study with participants drawn from two settings: a hospital and a community site. At the community site, individuals with newly diagnosed diabetes as well as a random sample of control individuals without diabetes, confirmed by oral glucose tolerance test, were selected. Participants underwent an LED light stimulus test and eight pupillometry variables were measured. Outcomes were diabetes, defined by oral glucose tolerance test, and cardiac autonomic dysfunction, determined by a positive readout on two of four diagnostic tests: heart rate response to the Valsalva manoeuvre; orthostatic hypotension; 30:15 ratio; and expiration-to-inspiration ratio. The area under the curve, best threshold, sensitivity and specificity of each pupillometry variable was calculated. Results Data from 384 people, 213 with diabetes, were analysed. The mean (±SD) age of the people with diabetes was 58.6 (±8.2) years and in the control subjects it was 56.1 (±8.6) years. When comparing individuals with and without diabetes, the amplitude of the pupil reaction had the highest area under the curve [0.69 (sensitivity: 78%; specificity: 55%)]. Cardiac autonomic neuropathy was present in 51 of the 138 people evaluated (37.0%; 95% CI 28.8–45.1). To diagnose cardiac autonomic neuropathy, two pupillometry variables had the highest area under the curve: baseline pupil radius [area under the curve: 0.71 (sensitivity: 51%; specificity: 84%)], and amplitude of the pupil reaction [area under the curve: 070 (sensitivity: 82%; specificity: 55%)]. Conclusions Pupillometry is an inexpensive technique to screen for diabetes and cardiac autonomic neuropathy, but it does not have sufficient accuracy for clinical use as a screening tool. PMID:25761508

Type 2 diabetes and cardiac autonomic neuropathy screening using dynamic pupillometry.

PubMed

Lerner, A G; Bernabé-Ortiz, A; Ticse, R; Hernandez, A; Huaylinos, Y; Pinto, M E; Málaga, G; Checkley, W; Gilman, R H; Miranda, J J

2015-11-01

To determine if changes in pupillary response are useful as a screening tool for diabetes and to assess whether pupillometry is associated with cardiac autonomic neuropathy. We conducted a cross-sectional study with participants drawn from two settings: a hospital and a community site. At the community site, individuals with newly diagnosed diabetes as well as a random sample of control individuals without diabetes, confirmed by oral glucose tolerance test, were selected. Participants underwent an LED light stimulus test and eight pupillometry variables were measured. Outcomes were diabetes, defined by oral glucose tolerance test, and cardiac autonomic dysfunction, determined by a positive readout on two of four diagnostic tests: heart rate response to the Valsalva manoeuvre; orthostatic hypotension; 30:15 ratio; and expiration-to-inspiration ratio. The area under the curve, best threshold, sensitivity and specificity of each pupillometry variable was calculated. Data from 384 people, 213 with diabetes, were analysed. The mean (±sd) age of the people with diabetes was 58.6 (±8.2) years and in the control subjects it was 56.1 (±8.6) years. When comparing individuals with and without diabetes, the amplitude of the pupil reaction had the highest area under the curve [0.69 (sensitivity: 78%; specificity: 55%)]. Cardiac autonomic neuropathy was present in 51 of the 138 people evaluated (37.0%; 95% CI 28.8-45.1). To diagnose cardiac autonomic neuropathy, two pupillometry variables had the highest area under the curve: baseline pupil radius [area under the curve: 0.71 (sensitivity: 51%; specificity: 84%)], and amplitude of the pupil reaction [area under the curve: 0.70 (sensitivity: 82%; specificity: 55%)]. Pupillometry is an inexpensive technique to screen for diabetes and cardiac autonomic neuropathy, but it does not have sufficient accuracy for clinical use as a screening tool. © 2015 The Authors. Diabetic Medicine © 2015 Diabetes UK.

Diagnostic accuracy of ultrasound in upper and lower extremity long bone fractures of emergency department trauma patients

PubMed Central

Frouzan, Arash; Masoumi, Kambiz; Delirroyfard, Ali; Mazdaie, Behnaz; Bagherzadegan, Elnaz

2017-01-01

Background Long bone fractures are common injuries caused by trauma. Some studies have demonstrated that ultrasound has a high sensitivity and specificity in the diagnosis of upper and lower extremity long bone fractures. Objective The aim of this study was to determine the accuracy of ultrasound compared with plain radiography in diagnosis of upper and lower extremity long bone fractures in traumatic patients. Methods This cross-sectional study assessed 100 patients admitted to the emergency department of Imam Khomeini Hospital, Ahvaz, Iran with trauma to the upper and lower extremities, from September 2014 through October 2015. In all patients, first ultrasound and then standard plain radiography for the upper and lower limb was performed. Data were analyzed by SPSS version 21 to determine the specificity and sensitivity. Results The mean age of patients with upper and lower limb trauma were 31.43±12.32 years and 29.63±5.89 years, respectively. Radius fracture was the most frequent compared to other fractures (27%). Sensitivity, specificity, positive predicted value, and negative predicted value of ultrasound compared with plain radiography in the diagnosis of upper extremity long bones were 95.3%, 87.7%, 87.2% and 96.2%, respectively, and the highest accuracy was observed in left arm fractures (100%). Tibia and fibula fractures were the most frequent types compared to other fractures (89.2%). Sensitivity, specificity, PPV and NPV of ultrasound compared with plain radiography in the diagnosis of upper extremity long bone fractures were 98.6%, 83%, 65.4% and 87.1%, respectively, and the highest accuracy was observed in men, lower ages and femoral fractures. Conclusion The results of this study showed that ultrasound compared with plain radiography has a high accuracy in the diagnosis of upper and lower extremity long bone fractures. PMID:28979747

Accuracy of methods for detecting an irregular pulse and suspected atrial fibrillation: A systematic review and meta-analysis.

PubMed

Taggar, Jaspal S; Coleman, Tim; Lewis, Sarah; Heneghan, Carl; Jones, Matthew

2016-08-01

Pulse palpation has been recommended as the first step of screening to detect atrial fibrillation. We aimed to determine and compare the accuracy of different methods for detecting pulse irregularities caused by atrial fibrillation. We systematically searched MEDLINE, EMBASE, CINAHL and LILACS until 16 March 2015. Two reviewers identified eligible studies, extracted data and appraised quality using the QUADAS-2 instrument. Meta-analysis, using the bivariate hierarchical random effects method, determined average operating points for sensitivities, specificities, positive and negative likelihood ratios (PLR, NLR); we constructed summary receiver operating characteristic plots. Twenty-one studies investigated 39 interventions (n = 15,129 pulse assessments) for detecting atrial fibrillation. Compared to 12-lead electrocardiography (ECG) diagnosed atrial fibrillation, blood pressure monitors (BPMs; seven interventions) and non-12-lead ECGs (20 interventions) had the greatest accuracy for detecting pulse irregularities attributable to atrial fibrillation (BPM: sensitivity 0.98 (95% confidence interval (CI) 0.92-1.00), specificity 0.92 (95% CI 0.88-0.95), PLR 12.1 (95% CI 8.2-17.8) and NLR 0.02 (95% CI 0.00-0.09); non-12-lead ECG: sensitivity 0.91 (95% CI 0.86-0.94), specificity 0.95 (95% CI 0.92-0.97), PLR 20.1 (95% CI 12-33.7), NLR 0.09 (95% CI 0.06-0.14)). There were similar findings for smartphone applications (six interventions) although these studies were small in size. The sensitivity and specificity of pulse palpation (six interventions) were 0.92 (95% CI 0.85-0.96) and 0.82 (95% CI 0.76-0.88), respectively (PLR 5.2 (95% CI 3.8-7.2), NLR 0.1 (95% CI 0.05-0.18)). BPMs and non-12-lead ECG were most accurate for detecting pulse irregularities caused by atrial fibrillation; other technologies may therefore be pragmatic alternatives to pulse palpation for the first step of atrial fibrillation screening. © The European Society of Cardiology 2015.

Dry-eye screening by using a functional visual acuity measurement system: the Osaka Study.

PubMed

Kaido, Minako; Uchino, Miki; Yokoi, Norihiko; Uchino, Yuichi; Dogru, Murat; Kawashima, Motoko; Komuro, Aoi; Sonomura, Yukiko; Kato, Hiroaki; Kinoshita, Shigeru; Tsubota, Kazuo

2014-05-06

We determined whether functional visual acuity (VA) parameters and a dry eyes (DEs) symptoms questionnaire could predict DEs in a population of visual terminal display (VDT) users. This prospective study included 491 VDT users from the Osaka Study. Subjects with definite DE, diagnosed with the presence of DE symptoms, tear abnormality (Schirmer test ≤ 5 mm or tear breakup time [TBUT] ≤ 5 seconds), and conjunctivocorneal epithelial damage (total staining score of ≥3 points), or probable DE, diagnosed with the presence of two of them, were assigned to a DE group, and the remainder to a non-DE group. Functional VA was assessed, and DE questionnaires were administered. We assessed whether univariate and discriminant analyses could determine to which group a subject belonged. Sensitivity and specificity were assessed. Of 491 subjects, 320 and 171 were assigned to the DE and non-DE groups, respectively. No significant differences were observed between DE and non-DE groups in Schirmer test value and epithelial damage, but TBUT value (3.1 ± 1.5 vs. 5.9 ± 3.0 seconds). The sensitivity and specificity of single test using functional VA parameters were 59% and 49% in functional VA, 60% and 50% in visual maintenance ratio, and 83% and 30% in frequency of blinking, respectively. According to a discriminant analysis using a combination of functional VA parameters and a DE questionnaire, six variables were selected for the discriminant equation, of which area under the curve (AUC) was 0.735. Sensitivity and specificity of diagnoses predicted by the discriminant equation were 85.9% and 45.6%, respectively. The discriminant equation obtained using functional VA measurement combined with a symptoms questionnaire may suggest the possibility for the first step screening of DE with unstable tear film. Since the questionnaire has an overall poor sensitivity and specificity, further amelioration may be necessary for the actual utilization of this screening tool. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

Development of a recombinase polymerase amplification assay for Vibrio parahaemolyticus detection with an internal amplification control.

PubMed

Yang, Huan-Lan; Wei, Shuang; Gooneratne, Ravi; Mutukumira, Anthony N; Ma, Xue-Jun; Tang, Shu-Ze; Wu, Xi-Yang

2018-04-01

A novel RPA-IAC assay using recombinase polymerase and an internal amplification control (IAC) for Vibrio parahaemolyticus detection was developed. Specific primers were designed based on the coding sequence for the toxR gene in V. parahaemolyticus. The recombinase polymerase amplification (RPA) reaction was conducted at a constant low temperature of 37 °C for 20 min. Assay specificity was validated by using 63 Vibrio strains and 10 non-Vibrio bacterial species. In addition, a competitive IAC was employed to avoid false-negative results, which co-amplified simultaneously with the target sequence. The sensitivity of the assay was determined as 3 × 10 3 CFU/mL, which is decidedly more sensitive than the established PCR method. This method was then used to test seafood samples that were collected from local markets. Seven out of 53 different raw seafoods were detected as V. parahaemolyticus-positive, which were consistent with those obtained using traditional culturing method and biochemical assay. This novel RPA-IAC assay provides a rapid, specific, sensitive, and more convenient detection method for V. parahaemolyticus.

The role of orbital ultrasonography in distinguishing papilledema from pseudopapilledema

PubMed Central

Carter, S B; Pistilli, M; Livingston, K G; Gold, D R; Volpe, N J; Shindler, K S; Liu, G T; Tamhankar, M A

2014-01-01

Purpose To determine the sensitivity and specificity of orbital ultrasonography in distinguishing papilledema from pseudopapilledema in adult patients. Methods The records of all adult patients referred to the neuro-ophthalmology service who underwent orbital ultrasonography for the evaluation of suspected papilledema were reviewed. The details of history, ophthalmologic examination, and results of ancillary testing including orbital ultrasonography, MRI, and lumbar puncture were recorded. Results of orbital ultrasonography were correlated with the final diagnosis of papilledema or pseudopapilledema on the basis of the clinical impression of the neuro-ophthalmologist. Ultrasound was considered positive when the optic nerve sheath diameter was ≥3.3 mm along with a positive 30° test. Results The sensitivity of orbital ultrasonography for detection of papilledema was 90% (CI: 80.2–99.3%) and the specificity in detecting pseudopapilledema was 79% (CI: 67.7–90.7%). Conclusions Orbital ultrasonography is a rapid and noninvasive test that is highly sensitive, but less specific in differentiating papilledema from pseudopapilledema in adult patients, and can be useful in guiding further management of patients in whom the diagnosis is initially uncertain. PMID:25190532

B-mode Ultrasound Versus Color Doppler Twinkling Artifact in Detecting Kidney Stones

PubMed Central

Harper, Jonathan D.; Hsi, Ryan S.; Shah, Anup R.; Dighe, Manjiri K.; Carter, Stephen J.; Moshiri, Mariam; Paun, Marla; Lu, Wei; Bailey, Michael R.

2013-01-01

Abstract Purpose To compare color Doppler twinkling artifact and B-mode ultrasonography in detecting kidney stones. Patients and Methods Nine patients with recent CT scans prospectively underwent B-mode and twinkling artifact color Doppler ultrasonography on a commercial ultrasound machine. Video segments of the upper pole, interpolar area, and lower pole were created, randomized, and independently reviewed by three radiologists. Receiver operator characteristics were determined. Results There were 32 stones in 18 kidneys with a mean stone size of 8.9±7.5 mm. B-mode ultrasonography had 71% sensitivity, 48% specificity, 52% positive predictive value, and 68% negative predictive value, while twinkling artifact Doppler ultrasonography had 56% sensitivity, 74% specificity, 62% positive predictive value, and 68% negative predictive value. Conclusions When used alone, B-mode is more sensitive, but twinkling artifact is more specific in detecting kidney stones. This information may help users employ twinkling and B-mode to identify stones and developers to improve signal processing to harness the fundamental acoustic differences to ultimately improve stone detection. PMID:23067207

Validity of self-reported stroke in elderly African Americans, Caribbean Hispanics, and Whites.

PubMed

Reitz, Christiane; Schupf, Nicole; Luchsinger, José A; Brickman, Adam M; Manly, Jennifer J; Andrews, Howard; Tang, Ming X; DeCarli, Charles; Brown, Truman R; Mayeux, Richard

2009-07-01

The validity of a self-reported stroke remains inconclusive. To validate the diagnosis of self-reported stroke using stroke identified by magnetic resonance imaging (MRI) as the standard. Community-based cohort study of nondemented, ethnically diverse elderly persons in northern Manhattan. High-resolution quantitative MRIs were acquired for 717 participants without dementia. Sensitivity and specificity of stroke by self-report were examined using cross-sectional analyses and the chi(2) test. Putative relationships between factors potentially influencing the reporting of stroke, including memory performance, cognitive function, and vascular risk factors, were assessed using logistic regression models. Subsequently, all analyses were repeated, stratified by age, sex, ethnic group, and level of education. In analyses of the whole sample, sensitivity of stroke self-report for a diagnosis of stroke on MRI was 32.4%, and specificity was 78.9%. In analyses stratified by median age (80.1 years), the validity between reported stroke and detection of stroke on MRI was significantly better in the younger than the older age group (for all vascular territories: sensitivity and specificity, 36.7% and 81.3% vs 27.6% and 26.2%; P = .02). Impaired memory, cognitive skills, or language ability and the presence of hypertension or myocardial infarction were associated with higher rates of false-negative results. Using brain MRI as the standard, specificity and sensitivity of stroke self-report are low. Accuracy of self-report is influenced by age, presence of vascular disease, and cognitive function. In stroke research, sensitive neuroimaging techniques rather than stroke self-report should be used to determine stroke history.

Benefit of cerebrospinal fluid spectrophotometry in the assessment of CT scan negative suspected subarachnoid haemorrhage: a diagnostic accuracy study.

PubMed

Hann, Angus; Chu, Kevin; Greenslade, Jaimi; Williams, Julian; Brown, Anthony

2015-01-01

This study aimed to determine if performing cerebrospinal fluid spectrophotometry in addition to visual inspection detects more ruptured cerebral aneurysms than performing cerebrospinal fluid visual inspection alone in patients with a normal head CT scan but suspected of suffering an aneurysmal subarachnoid haemorrhage (SAH). We performed a single-centre retrospective study of patients presenting to the emergency department of a tertiary hospital who underwent both head CT scan and lumbar puncture to exclude SAH. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of an approach utilising both spectrophotometry and visual inspection (combined approach) was compared to visual inspection alone. A total of 409 patients (mean age 37.8 years, 56.2% female) were recruited and six (1.5%) had a cerebral aneurysm on angiography. The sensitivity of visual inspection was 50% (95% confidence interval [CI]: 12.4-82.6%), specificity was 99% (95% CI: 97.5-99.7%), PPV was 42.9% (95% CI: 10.4-81.3%) and NPV was 99.2% (95% CI: 97.8-99.8%). The combined approach had a sensitivity of 100% (95% CI: 54.1-100%), specificity of 79.7% (95% CI: 75.4-83.5%), PPV of 6.8% (95% CI: 2.6-14.3%) and a NPV of 100% (95% CI: 98.8-100%). The sensitivity of the combined approach was not significantly different to that of visual inspection alone (p=0.25). Visual inspection had a significantly higher specificity than the combined approach (p<0.01). The combined approach detected more cases of aneurysmal SAH than visual inspection alone, however the difference in sensitivity was not statistically significant. Visual xanthochromia should prompt angiography because of a superior specificity and PPV. Due to its reduced sensitivity, caution should be applied when using only visual inspection of the supernatant. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Evaluation of the articular cartilage of the knee joint: value of adding a T2 mapping sequence to a routine MR imaging protocol.

PubMed

Kijowski, Richard; Blankenbaker, Donna G; Munoz Del Rio, Alejandro; Baer, Geoffrey S; Graf, Ben K

2013-05-01

To determine whether the addition of a T2 mapping sequence to a routine magnetic resonance (MR) imaging protocol could improve diagnostic performance in the detection of surgically confirmed cartilage lesions within the knee joint at 3.0 T. This prospective study was approved by the institutional review board, and the requirement to obtain informed consent was waived. The study group consisted of 150 patients (76 male and 74 female patients with an average age of 41.2 and 41.5 years, respectively) who underwent MR imaging and arthroscopy of the knee joint. MR imaging was performed at 3.0 T by using a routine protocol with the addition of a sagittal T2 mapping sequence. Images from all MR examinations were reviewed in consensus by two radiologists before surgery to determine the presence or absence of cartilage lesions on each articular surface, first by using the routine MR protocol alone and then by using the routine MR protocol with T2 maps. Each articular surface was then evaluated at arthroscopy. Generalized estimating equation models were used to compare the sensitivity and specificity of the routine MR imaging protocol with and without T2 maps in the detection of surgically confirmed cartilage lesions. The sensitivity and specificity in the detection of 351 cartilage lesions were 74.6% and 97.8%, respectively, for the routine MR protocol alone and 88.9% and 93.1% for the routine MR protocol with T2 maps. Differences in sensitivity and specificity were statistically significant (P < .001). The addition of T2 maps to the routine MR imaging protocol significantly improved the sensitivity in the detection of 24 areas of cartilage softening (from 4.2% to 62%, P < .001), 41 areas of cartilage fibrillation (from 20% to 66%, P < .001), and 96 superficial partial-thickness cartilage defects (from 71% to 88%, P = .004). The addition of a T2 mapping sequence to a routine MR protocol at 3.0 T improved sensitivity in the detection of cartilage lesions within the knee joint from 74.6% to 88.9%, with only a small reduction in specificity. The greatest improvement in sensitivity with use of the T2 maps was in the identification of early cartilage degeneration. © RSNA, 2013.

Comparative application of IS711-based polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) for canine brucellosis diagnosis.

PubMed

Batinga, Maria Cryskely Agra; de Lima, Julia Teresa Ribeiro; Gregori, Fabio; Diniz, Jaqueline Assumpção; Muner, Kerstin; Oliveira, Trícia M F S; Ferreira, Helena Lage; Soares, Rodrigo Martins; Keid, Lara Borges

2018-06-01

Canine brucellosis is caused by Brucella canis, a gram negative and facultative intracellular bacterium that is commonly associated with reproductive failures in dogs. The accurate diagnosis of the infection relies on the use of serological tests associated with blood culturing to guarantee sensitivity. The polymerase chain reaction (PCR) can replace the culturing procedure for the direct diagnosis of the infection because of its speed, high specificity and sensitivity values; however, it depends on some laboratory infrastructure to be conducted. The loop-mediated isothermal amplification (LAMP) may be an alternative method for DNA amplification in a shorter period, using simpler equipment, and with a lower cost. This study evaluated the potential of molecular tools based on PCR and LAMP using primers targeting the insertion sequence IS711 for Brucella detection in three groups of dogs (infected, non-infected and suspected of brucellosis), which were determined according to the results of blood culturing and clinical examination. The performance of the three diagnostic tests was also determined using McNemar test and Kappa coefficient. The proportion of positive samples detected by blood culturing, PCR and LAMP was respectively 31.57% (18/57), 33.34% (19/57), and 14.03% (8/57). The agreement between blood culturing and PCR was almost perfect, while the agreement of PCR and blood culturing compared to LAMP was fair. The diagnostic sensitivity of PCR and LAMP was respectively 100% (18/18) and 44.44% (8/18), while the diagnostic specificity of both tests was 100% (21/21). LAMP performance was not satisfactory for canine brucellosis diagnosis because of the low diagnostic sensitivity of the test. The IS711 based PCR, otherwise, showed high values of sensitivity and specificity, which makes it a good alternative for use for the rapid diagnosis of canine brucellosis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Modeling ozone episodes in the Baltimore-Washington region

NASA Technical Reports Server (NTRS)

Ryan, William F.

1994-01-01

Surface ozone (O3) concentrations in excess of the National Ambient Air Quality Standard (NAAQS) continue to occur in metropolitan areas in the United States despite efforts to control emissions of O3 precursors. Future O3 control strategies will be based on results from modeling efforts that have just begun in many areas. Two initial questions that arise are model sensitivity to domain-specific conditions and the selection of episodes for model evaluation and control strategy development. For the Baltimore-Washington region (B-W), the presence of the Chesapeake Bay introduces a number of issues relevant to model sensitivity. In this paper, the specific questions of the determination of model volume (mixing height) for the Urban Airshed Model (UAM) is discussed and various alternative methods compared. For the latter question, several analytic approaches, Cluster Analysis and classification and Regression Tree (CART) analysis are undertaken to determine meteorological conditions associated with severe O3 events in the B-W domain.

Natural gas applications for hybrid vehicles. Final report, October 1992-July 1993

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bentley, J.M.

1993-08-01

Hybrid vehicle technology holds the potential for improved efficiency and emissions compared with internal combustion (IC) engines and improved range and refueling convenience over electric vehicles. This study evaluated the potential for using natural gas as a hybrid vehicle fuel. Potential regulatory and market drivers were evaluated for hybrids generally and natural gas hybrids in specific. Heat engine options and other configuration issues were investigated to determine efficiency, emissions or other benefits of light- and heavy-duty hybrids. Several hybrid vehicle configurations were evaluated to determine the specific packaging attributes of natural gas in a hybrid configuration. Generally, conventional IC enginesmore » appear adequate for most emissions-sensitive hybrid applications with no great advantage being gained from using turbines or other more advanced heat engines. The largest technology barrier to a near-term hybrid is the weight of available or near-term batteries. Smaller, light-duty hybrid vehicles will be more sensitive to this weight handicap than larger vehicles such as the urban transit bus.« less

Protein microarray with horseradish peroxidase chemiluminescence for quantification of serum α-fetoprotein.

PubMed

Zhao, Yuanshun; Zhang, Yonghong; Lin, Dongdong; Li, Kang; Yin, Chengzeng; Liu, Xiuhong; Jin, Boxun; Sun, Libo; Liu, Jinhua; Zhang, Aiying; Li, Ning

2015-10-01

To develop and evaluate a protein microarray assay with horseradish peroxidase (HRP) chemiluminescence for quantification of α-fetoprotein (AFP) in serum from patients with hepatocellular carcinoma (HCC). A protein microarray assay for AFP was developed. Serum was collected from patients with HCC and healthy control subjects. AFP was quantified using protein microarray and enzyme-linked immunosorbent assay (ELISA). Serum AFP concentrations determined via protein microarray were positively correlated (r = 0.973) with those determined via ELISA in patients with HCC (n = 60) and healthy control subjects (n = 30). Protein microarray showed 80% sensitivity and 100% specificity for HCC diagnosis. ELISA had 83.3% sensitivity and 100% specificity. Protein microarray effectively distinguished between patients with HCC and healthy control subjects (area under ROC curve 0.974; 95% CI 0.000, 1.000). Protein microarray is a rapid, simple and low-cost alternative to ELISA for detecting AFP in human serum. © The Author(s) 2015.

Juvenile-onset localized scleroderma activity detection by infrared thermography.

PubMed

Martini, G; Murray, K J; Howell, K J; Harper, J; Atherton, D; Woo, P; Zulian, F; Black, C M

2002-10-01

The aim of this study was to define the clinical utility of infrared thermography in disease activity detection in localized scleroderma (LS). We retrospectively reviewed 130 thermal images of 40 children with LS and calculated the sensitivity and specificity of thermography, comparing clinical descriptions of the lesions and contemporary thermographs. The reproducibility of thermography was calculated by using the weighted kappa coefficient to determine the level of agreement between two clinicians who reviewed the thermographs independently. The sensitivity of thermography was 92% and specificity was 68%. Full concordance between the two clinicians was observed in 91% of lesions, with a kappa score of 0.82, implying very high reproducibility of this technique. Our results demonstrate that thermography is a promising diagnostic tool when associated with clinical examination in discriminating disease activity, as long as it is applied to lesions without severe atrophy of the skin and subcutaneous fat. Further evaluation is needed to determine whether thermography can predict the future progression of lesions.

Sex-specific genetic determinants for arterial stiffness in Dahl salt-sensitive hypertensive rats.

PubMed

Decano, Julius L; Pasion, Khristine A; Black, Nicole; Giordano, Nicholas J; Herrera, Victoria L; Ruiz-Opazo, Nelson

2016-01-11

Arterial stiffness is an independent predictor of cardiovascular outcomes in hypertensive patients including myocardial infarction, fatal stroke, cerebral micro-bleeds which predicts cerebral hemorrhage in hypertensive patients, as well as progression to hypertension in non-hypertensive subjects. The association between arterial stiffness and various cardiovascular outcomes (coronary heart disease, stroke) remains after adjusting for age, sex, blood pressure, body mass index and other known predictors of cardiovascular disease, suggesting that arterial stiffness, measured via carotid-femoral pulse wave velocity, has a better predictive value than each of these factors. Recent evidence shows that arterial stiffening precedes the onset of high blood pressure; however their molecular genetic relationship (s) and sex-specific determinants remain uncertain. We investigated whether distinct or shared genetic determinants might underlie susceptibility to arterial stiffening in male and female Dahl salt-sensitive rats. Thus, we performed a genome-wide scan for quantitative trait loci (QTLs) affecting arterial stiffness in six-week old F2 (Dahl S x R)-intercross male and female rats characterized for abdominal aortic pulse wave velocity and aortic strain by high-resolution ultrasonography. We detected five highly significant QTLs affecting aortic stiffness: two interacting QTLs (AS-m1 on chromosome 4 and AS-m2 on chromosome16, LOD 8.8) in males and two distinct interacting QTLs (AS-f1 on chromosome 9 and AS-f2 on chromosome11, LOD 8.9) in females affecting pulse wave velocity. One QTL (AS-1 on chromosome 3, LOD 4.3) was found to influence aortic strain in a sex-independent manner. None of these arterial stiffness QTLs co-localized with previously reported blood pressure QTLs detected in equivalent genetic intercrosses. These data reveal sex-specific genetic determinants for aortic pulse wave velocity and suggest distinct polygenic susceptibility for arterial stiffness and salt-sensitive hypertension in Dahl rats based upon reported blood pressure QTLs in equivalent (Dahl S x R)-intercrosses.

Specific features of the planarian Dugesia tigrina regeneration and mollusk Helix albescens nociception under weak electromagnetic shielding

NASA Astrophysics Data System (ADS)

Temur'yants, N. A.; Demtsun, N. A.; Kostyuk, A. S.; Yarmolyuk, N. S.

2012-12-01

It has been demonstrated that weak electromagnetic shielding stimulates regeneration in the planarian Dugesia tigrina, the stimulating intensity being dependent on both the initial state of the animals, which is determined by season, and their functional asymmetry. As has been shown, the effect of a weak electromagnetic field induces phasic changes in the nociceptive sensitivity of the mollusk Helix albescens: an increase in the sensitivity to a thermal stimulus is replaced by the development of the hypalgesic effect.