With the rising number of patients who rely on medical care, it is necessary to use evolving health care technology appropriately, to control health care costs, and to enhance the well-being of patients in the home care setting. Point of care testing (POCT)is instrumental system for such demands for home care; however, this term remains relatively unknown in Japan. For this research, I conducted a qualitative analysis of factors based on stories obtained through group interviews of 11 experienced home visiting nurses who work at three home-visit nursing stations for the purpose of clarifying issues in the introduction of POCT. The results of the research identified five categories and 16 subcategories for issues in the introduction of POCT. The identified categories are expected to be useful for the spread of POCT in the future. Key words: Point of care testing, Home care nursing. PMID:25595090
Background Globally, no qualitative studies have explored the perspectives of women and their partners about the integration of technology – and specifically diagnostic testing technologies – into antenatal care. The study objective was to describe the demand side for pregnancy-related diagnostic tests from the perspective of Peruvian consumers, including female and male community members, by engaging participants about their awareness of and care-seeking for pregnancy-related diagnostic tests and their preferred characteristics and testing conditions for pregnancy-related point-of-care diagnostic tests (POCTs). Methods Sixty-seven mothers and fathers of children under one from the peri-urban coast and the peri-urban and rural highlands and jungle of Peru participated in ten focus groups. Results Participants think that pregnancy-related diagnostic tests are important and they and their fellow community members are committed to ensuring that pregnant women receive the tests they need. Participants expressed clear demands for pregnancy-related POCTs, including important characteristics for the tests themselves (certification, rapid, reliable results) and for test implementation (well-trained, personable good communicators as test administrators at well-equipped, convenient testing sites). Participants emphasized the importance of short waiting times and explained that many people have some ability to pay for POCTs, particularly if they are innovative, rapid or multiplex. Conclusions Engaging future POCT users as consumers who are able to make key decisions about the development and implementation of pregnancy-related POCTs is valuable and informative. PMID:24433514
Point-of-care testing (POCT) is a fast developing area in clinical diagnostics that is considered to be one of the main driving\\u000a forces for the future in vitro diagnostic market. POCT means decentralized testing at the site of patient care. The most important\\u000a POCT devices are handheld blood glucose sensors. In some of these sensors, after the application of less than
Point-of-care test devices (POCT) constitute one group of in vitro diagnostic (IVD) medical devices. Approval to offer IVDs in the European Common Market is shown by the CE mark which indicates that the test conforms with the IVD directive. POCT have to fulfill the same require- ments as all other laboratory IVDs. The device is CE- marked by the manufacturer
The availability of rapid, point-of-care (POC) tests has significantly expanded the capacity of both developed and resource-constrained\\u000a countries (RCCs) to diagnose HIV, with immunochromatographic tests most commonly used in these settings. This has been especially\\u000a important in programs for prevention of mother-to-child transmission, in both RCCs and the developed world. However, suitable\\u000a POC tests are not yet commercially available for
David A. Anderson; Suzanne M. Crowe; Mary Garcia
We developed a portable and easy-to-use nucleic acid amplification test (NAT) system for use in point-of-care testing (POCT). The system shows sensitivity that is sufficiently higher than that of the currently available rapid diagnostic kit and is comparable to that of real-time reverse transcription polymerase chain reaction (RT-PCR) for influenza testing. PMID:21311813
Abe, Tomoteru; Segawa, Yuji; Watanabe, Hidetoshi; Yotoriyama, Tasuku; Kai, Shinichi; Yasuda, Akio; Shimizu, Norio; Tojo, Naoko
BACKGROUND: While point of care testing (PoCT) for general practitioners is becoming increasingly popular, few studies have investigated whether it represents value for money. This study aims to assess the relative cost-effectiveness of PoCT in general practice (GP) compared to usual testing practice through a pathology laboratory. METHODS: A cost-effectiveness analysis based on a randomized controlled trial with 4,968 patients
Caroline O Laurence; John R Moss; Nancy E Briggs; Justin J Beilby
Acute myocardial infarction (AMI) is the world's leading cause of mortality and morbidity. Therefore, quick and reliable diagnostics of AMI is extremely critical. Compared to the traditionally used central laboratory tests (CLT), which can be time-consuming and expensive, point-of-care testing (POCT) for AMI-indicative cardiac markers provides a convenient means for rapid diagnostic assays to be performed at the site of
Zhen Yang; Dao Min Zhou
Background Besides the great importance of the issue in terms of public health, there is a lack of studies evaluating the performance of several of the currently used point of care tests (POCTs) for the detection of anti-HCV. Objectives To investigate the performance of two POCTs for anti-HCV detection and to assess the impact of the reading time on diagnostic performance. Patients and Methods A total of 307 subjects were divided into three groups (1- HCV infected; 2- other chronic liver diseases; and 3- controls). The POCTs HCV Rapid Test Bioeasy® and Imuno-Rapido HCV® were read at 3, 5, 10, 15, 20 and 30 minutes. The sensitivity and specificity of the POCTs were calculated in relation to anti-HCV detection by chemiluminescence. Results Valid results were obtained for all tests. When compared to the chemiluminescence, both tests showed sensitivity of 97.1% and specificity of 100%. No changes in the sensitivity or specificity of the tests were observed at different reading times and when patients with other chronic liver diseases were evaluated as a control group. Conclusions The POCTs evaluated in this study showed high sensitivity and specificity, with no change in the performance after the third minute of reading. PMID:24282422
da Rosa, Lígia; Dantas-Corrêa, Esther Buzaglo; Narciso-Schiavon, Janaína Luz; Schiavon, Leonardo de Lucca
Background Coeliac disease (CD), due to its protean clinical manifestation, is still very under diagnosed in adults and delays in diagnosis may take years and even decades. Simple tools to find cases in primary care may help to identify patients for further diagnostic tests. We have evaluated the usefulness of an on site rapid fingertip whole blood point-of-care test (POCT) for such a purpose. Methods As CD is known to run within families, we tested 148 healthy relatives of 70 Romanian index cases with biopsy-proven CD (87% of all first-degree family members, median age 36 years) for the presence of circulating autoantibodies. In addition to performing the POCT (which measures blood erythrocyte self-TG2-autoantibody complexes) on site, blood was drawn for later evaluations of serum IgA-class endomysial antibodies (EMA). EMA-positive sera were further tested for transglutaminase 2 antibodies (TG2-IgA). All serological parameters were analyzed blindly in a centralized laboratory that had no knowledge of the on site POCT result. Endoscopic small intestinal biopsies was recommended for all POCT- or EMA-test positive subjects. Results In on site testing the POCT was positive in 12/148 first-degree relatives (8%) and all these subjects were also serum EMA-positive. A positive EMA test was found only in one other subject. All remaining 135 healthy first-degree relatives were negative for both POCT and EMA. Four subjects positive for both POCT and EMA were negative for TG2-IgA. Ten out of thirteen of the antibody-positive subjects agreed to undergo endoscopy. The POCT was found to be positive in 8/9 first-degree relatives having coeliac-type mucosal lesions of grade Marsh 2 (n?=?3) or Marsh 3 (n?=?6). The three POCT-positive subjects not agreeing to undergo endoscopy were also both EMA- and TG2-IgA-positive. Conclusion The fingertip whole blood rapid POCT might fulfill the unmet need for a simple and cheap case-finding biomarker for early detection and presumptive diagnosis of CD. Confirmatory studies are warranted in adult case-finding in specialized outpatient clinics and in primary care. PMID:23849178
BackgroundA point-of-care test (POCT) for sexually transmitted infections (STIs), which offers immediate diagnosis resulting in patients receiving diagnosis and treatment in a single visit, has the ability to address some of the STI control needs. However, needs assessment from STI experts and end users about currently available STI POCTs and their future new development has not been evaluated since World
Yu-Hsiang Hsieh; M. Terry Hogan; Mathilda Barnes; Mary Jett-Goheen; Jill Huppert; Anne M. Rompalo; Charlotte A. Gaydos; Patricia Kissinger
Involvement of health personnel in a medical audit can reduce the number of errors in laboratory medicine. The checked control of point of care testing (POCT) could be an answer to developing a better medical service in the emergency department and decreasing the time taken to report tests. The performance of sanitary personnel from different disciplines was studied over an 18-month period in a children's hospital. Clinical errors in the emergency and laboratory departments were monitored by: nursing instruction using specific courses, POCT, and external quality control; improvement of test results and procedural accuracy; and reduction of hemolyzed and nonprotocol-conforming samples sent to the laboratory department. In January 2012, point of care testing (POCT) was instituted in three medical units (neonatology, resuscitation, delivery room) at the Children's Hospital in Trieste, northeast Italy, for analysis of hematochemical samples. In the same period, during the months of January 2012 and June 2013, 1,600 samples sent to central laboratory and their related preanalytical errors were examined for accuracy. External quality control for POCT was also monitored in the emergency department; three meetings were held with physicians, nurses, and laboratory technicians to highlight problems, ie, preanalytical errors and analytical methodologies associated with POCT. During the study, there was an improvement in external quality control for POCT from -3 or -2 standard deviations or more to one standard deviation for all parameters. Of 800 samples examined in the laboratory in January 2012, we identified 64 preanalytical errors (8.0%); in June 2013, there were 17 preanalytical errors (2.1%), representing a significant decrease (P<0.05, ?(2) test). Multidisciplinary management and clinical audit can be used as tools to detect errors caused by organizational problems outside the laboratory and improve clinical and economic outcomes. PMID:24474844
Parco, Sergio; Visconti, Patrizia; Vascotto, Fulvia
Point-of-care testing (POCT) of infectious bacterial agents offers substantial benefits for disease diagnosis, mainly by shortening the time required to obtain results and by making the test available bedside or at remote care centers. Immunochromatographic lateral flow biosensors offer a low cost, highly sensitive platform for POCT. In this article, we describe the fabrication and testing of a multiplex immuno-disc sensor for the specific detection of Pseudomonas aeruginosa and Staphylococcus aureus. Antibody conjugated gold nanoparticles were used as the signaling agents. The detection range of the bacteria lies within 500-5000 CFU/ml. The advantage of the immuno-disc sensor is that it does not require any preprocessing of biological sample and is capable of whole cell bacterial detection. We also describe the design and fabrication of a compact portable device which converts the color intensity of the gold nanoparticles that accumulate at the test region into a quantitative voltage reading proportional to the bacterial concentration in the sample. The combination of the immuno-disc and the portable color reader provides a rapid, sensitive, low cost, and quantitative tool for the detection of a panel of infectious agents present in the patient sample. PMID:21592765
Li, Chen-zhong; Vandenberg, Katherine; Prabhulkar, Shradha; Zhu, Xuena; Schneper, Lisa; Methee, Kalai; Rosser, Charles J; Almeide, Eugenio
The diverse diagnostic market offers a wide range of devices for Point-of-Care-Testing (POCT). Usually these devices feature a high level of automation ranging from hand- held POCT-systems to bench top instruments. Placed in operating rooms, emergency hospitalization, and intensive care units these diagnostic tools have decreased the turn-around-time for diagnostics drastically. The applied transduction technologies are either based on electrochemical
Introduction: Forward deployed military medical units can provide sophisticated medical care with limited resources. Point-of-Care Testing (POCT) may facilitate care and expedite diagnosis. This study assessed the accuracy of results for POCT for non-serum samples (pleural, peritoneal, and cerebrospinal fluid) using iSTAT and Piccolo hand-held devices compared with results obtained using a hospital chemistry analyzer. Methods: Pleural, peritoneal, and cerebrospinal fluids obtained during routine care were simultaneously analyzed on a Vitros 5600 automated clinical chemistry hospital analyzer, iSTAT, and Piccolo POCT devices. Results: POCT results were highly correlated with the Vitros 5600 for pleural fluid LDH, glucose, and triglycerides (TG); for peritoneal fluid bilirubin, TG, glucose, albumin, and protein; and glucose for cerebrospinal fluid. Conclusion: POCT results for non-serum samples from pleural, peritoneal, and cerebrospinal fluid correlate with standard hospital chemistry analysis. The results of this study demonstrate potential for possible new diagnostic roles for POCT in resource-limited environments. PMID:25285247
Davis, Konrad; Helman, Donald; Abadie, Jude
Abstract Objective To evaluate the performance of a newly developed point-of-care test (POCT) for the detection of measles-specific IgM antibodies in serum and oral fluid specimens and to assess if measles virus nucleic acid could be recovered from used POCT strips. Methods The POCT was used to test 170 serum specimens collected through measles surveillance or vaccination programmes in Ethiopia, Malaysia and the Russian Federation: 69 were positive for measles immunoglobulin M (IgM) antibodies, 74 were positive for rubella IgM antibodies and 7 were positive for both. Also tested were 282 oral fluid specimens from the measles, mumps and rubella (MMR) surveillance programme of the United Kingdom of Great Britain and Northern Ireland. The Microimmune measles IgM capture enzyme immunoassay was the gold standard for comparison. A panel of 24 oral fluids was used to investigate if measles virus haemagglutinin (H) and nucleocapsid (N) genes could be amplified by polymerase chain reaction directly from used POCT strips. Findings With serum POCT showed a sensitivity and specificity of 90.8% (69/76) and 93.6% (88/94), respectively; with oral fluids, sensitivity and specificity were 90.0% (63/70) and 96.2% (200/208), respectively. Both H and N genes were reliably detected in POCT strips and the N genes could be sequenced for genotyping. Measles virus genes could be recovered from POCT strips after storage for 5 weeks at 20–25 °C. Conclusion The POCT has the sensitivity and specificity required of a field-based test for measles diagnosis. However, its role in global measles control programmes requires further evaluation. PMID:21897488
Slibinskas, Rimantas; Chua, Kaw Bing; Nigatu, Wondatir; Brown, Kevin E; Sasnauskas, Kestutis; Samuel, Dhanraj; Brown, David
It is an urgent need of highly sensitive, specific and economical diagnostic tools for early and fast diagnosis of highly challenging dengue virus infections. Many laboratory methods including virus detection, genome detection, antigen detection and serological detection of such short-lived viremia were explored but promising outcomes for economical immunochromatographic tests have been reported in this review. With the trend of fast, easy operation, rapid diagnostic tests (RDT) based on immunochromatographic assays are of great importance due to point of care test (POCT) in the dengue endemic regions where it is short of laboratory equipments and cold storage conditions. Such kind of point of care diagnosis is more efficient, fast and user friendly. Moreover, the development of highly advance RDT is dependent on the use of anti-dengue monoclonal antibodies highly specific for particular analyte/antigen. PMID:25553705
Fatima, Aneela; Wang, Jufang
Point-of-care (POC) testing in hemostasis has experienced a significant increase in the spectrum of available tests and the number of tests performed. Short turn-around time and observation of rapid changes in test results are facilitated. The quality control process in POC testing must encompass a preanalytic (collection), analytic (measurement), and postanalytic (clinical response) phase. Erroneous interpretation of findings and difficult quality controls can outweigh the advantages of POC testing.Only a limited number of hemostatic POC tests have proven useful so far: prothrombin time POC-monitoring of oral vitamin K antagonists; activated clotting time POC-monitoring of high-dose heparin therapy; platelet function analyzer (PFA; Siemens, Marburg, Germany) closure time (CT)-detection of von Willebrand disease and severe platelet function defects; whole blood aggregometry (WBA) Multiplate (Roche Diagnostics, Rotkreuz, Switzerland), and the VerifyNow system (Accumetrics, San Diego, CA)-detection of platelet dysfunction due to antiplatelet drugs; thromboelastography-continuous observation of clot formation and fibrinolysis. The use of various agonists in WBA and thromboelastography (TEG) requires some expertise. In experienced hands the PFA CT and WBA and TEG are recommended combinations.Application of POC testing depends strictly on whether it improves medical care and patient outcome. More POC test systems are in the research pipeline, but only a few will resist the ravages of time. PMID:25611850
Fries, Dietmar; Streif, Werner
In the last years several point of care testing (POCT) systems used for coagulation parameters have been developed and became daily routine. As for other POCT applications (e. g. blood gas analysis) there is a need for user education and continuous improvement of quality assurance. For some POCT coagulation systems a comprehensive quality management has not been established yet. According to the feasibility and availability of control material and system self control each POCT coagulation method described in this article has a varying concept of quality management. Besides a high quality standard in manufacturing systems, devices and reagents the education of the user and the automatic self control of the instrument as well as the application of electronic and/ or liquid control samples contribute to the total quality assurance. Even if a "like versus like" control material is not available a comprehensive quality management should be implemented in daily routine concerning pre-analytic as well as technical and post-analytic criteria. Anyway to do nothing as the available control material seems to be not suitable is a bad decision. PMID:20454752
Spannagl, Michael; Dick, A; Junker, R
HIV counselling and testing has traditionally been performed by highly trained professionals in clinical settings. With HIV rapid testing, a reliable and easy to use diagnostic tool, paraprofessionals can be trained to administer on-site HIV testing in a variety of non-traditional settings, broadening the HIV detection rates. Our objective was to create a robust and sustainable paraprofessional training module to facilitate off-site HIV rapid testing in non-clinical settings. Trainees attended a series of training sessions involving HIV education, rapid test instructions and communication techniques. After these sessions, trainees competently carried out HIV rapid testing in homeless shelters throughout the Los Angeles county. Agencies motivated to expand HIV screening programmes may use trained paraprofessionals to administer a full range of services (recruitment, pretest counselling, test administration, interpretation of results, post-test counselling and documentation) through this training model and enabling more highly trained healthcare providers to focus efforts on patients identified as HIV-positive. PMID:18725556
Knapp, Herschel; Anaya, Henry D; Feld, Jamie E
Objectives The purpose of this study was to design an integrated data management system based on the POCT1-A2, LIS2-A, LIS2-A2, and HL7 standard to ensure data interoperability between mobile equipment, such as point-of-care testing equipment and the existing hospital data system, its efficiency was also evaluated. Methods The method of this study was intended to design and realize a data management system which would provide a solution for the problems that occur when point-of-care testing equipment is introduced to existing hospital data, after classifying such problems into connectivity, integration, and interoperability. This study also checked if the data management system plays a sufficient role as a bridge between the point-of-care testing equipment and the hospital information system through connection persistence and reliability testing, as well as data integration and interoperability testing. Results In comparison with the existing system, the data management system facilitated integration by improving the result receiving time, improving the collection rate, and by enabling the integration of disparate types of data into a single system. And it was found out that we can solve the problems related to connectivity, integration and interoperability through generating the message in standardized types. Conclusions It is expected that the proposed data management system, which is designed to improve the integration point-of-care testing equipment with existing systems, will establish a solid foundation on which better medical service may be provided by hospitals by improving the quality of patient service. PMID:24175121
Park, Ki Sang; Heo, Hyuk
Introduction A point of care test (POCT) for Chlamydia trachomatis detection is an urgent public health need. Technology advances in diagnostics have made solutions possible. Yet no reliable POCT exist. Our goal was to address the gap between chlamydia POCT needs and successful POCT development by determining which characteristics of POCT tests are most critical and if any flexibility in the attributes assigned those characteristics exist between technology developer and end user. Methods We employed a process known as WALEX (Warfare Analysis Laboratory Exercise) in combination with Design of Experiment (DOE) methodology using discrete choice experiments (DCE), to describe the attributes of the most realistic, rather than the most ideal POCT. The WALEX was conducted as interactive oral and simultaneous electronic discussion among experts with differing expertise, but linked by a common interest in development of a chlamydia POCT. Results Our studies demonstrated which features of the ideal chlamydia POCT were considered critical to test acceptance by users and which were open to negotiation. In particular, end users were more lenient on the requirement for the fastest ideal test and the lowest one time instrument costs, if the requirement for higher throughput, lowest cost and vaginal sample source collection were preserved. DOE methods used in forced choice question design provided confirmation of opinions derived from oral and electronic WALEX comments Conclusions The WALEX in combination with DCE helped us achieve our goal in identifying the gaps in the chlamydia POCT and determining the most realistic solutions to bridge those gaps. PMID:22919287
Jackman, Joany; Uy, Manny; Hsieh, Yu-Hsiang; Rompalo, Anne; Hogan, Terry; Huppert, Jill; Jett-Goheen, Mary; Gaydos, Charlotte
Reversing and arresting the epidemic of HIV are a challenge for any country. Early diagnosis and rapid initiation of treatment remain a key strategy in the control of HIV. Technological advances in the form of low-cost rapid point-of-care tests have completely transformed the diagnosis and management of HIV, especially in resource limited settings, where health infrastructure is poor and timely access to medical care is a challenge. Point-of-care devices have proven to be easy to transport, operate, and maintain, and also lower-skilled staff is equally able to perform these tests as compared to trained laboratory technicians. Point-of-care tests allow rapid detection of HIV allowing for rapid initiation of therapy, monitoring of antiretroviral therapy and drug toxicity, and detection of opportunistic infections and associated illnesses. PMID:24052887
Arora, D. R.; Maheshwari, Megha; Arora, B.
BackgroundInfection by Chlamydia trachomatis (CT) is the most prevalent sexually transmitted infection (STI) world wide. The most frequently used diagnostic test for CT is a nucleic acid amplification test (NAAT), which is highly sensitive and specific. To further shorten time delay until diagnosis has been made, in order to prevent CT spread, the use of point-of-care (POC) tests may be
Laura van Dommelen; Frank H van Tiel; Sander Ouburg; Elfi E H G Brouwers; Peter H W Terporten; Paul H M Savelkoul; Servaas A Morré; Cathrien A Bruggeman; Christian J P A Hoebe
The purpose of this study was to evaluate the accuracy of glucometers in assessing glucose levels in outpatients. The investigation consisted in the analysis of retrospective validation data (obtained at the Clinical Laboratory of the Puerto Rico Medical Services Administration) and the analysis of data obtained from forty outpatients. Glucose concentration was obtained from these outpatient samples using the patients' glucometers and a clinical laboratory analyzer (hexokinase method). Statistical analysis included descriptive and correlation measures and t-test. Results revealed that accurate glucose values were obtained by the glucometers utilized in both the validation process and the outpatients (POCT) procedure. The investigation also demonstrated the need by outpatients to receive proper training in handling their glucometers. PMID:14768505
Velázquez Medina, Diana; Climent, Consuelo
Background The proper development and implementation of point-of-care (POC) diagnostics requires knowledge of the perceived requirements and barriers to their implementation. To determine the current requirements and perceived barriers to the introduction of POC diagnostics in the field of medical microbiology (MM)-POC a prospective online survey (TEMPOtest-QC) was established. Methods and results The TEMPOtest-QC survey was online between February 2011 and July 2012 and targeted the medical community, POC test diagnostic manufacturers, general practitioners, and the general public. In total, 293 individuals responded to the survey, including 91 (31%) medical microbiologists, 39 (13%) nonmedical microbiologists, 25 (9%) employees of POC test manufacturers, and 138 (47%) members of the general public. Responses were received from 18 different European countries, with the largest percentage of these living in The Netherlands (52%). The majority (>50%) of medical specialists regarded the development of MM-POC for blood culture and hospital acquired infections as “absolutely necessary”, but were much less favorable towards their use in the home environment. Significant differences in perceptions between medical specialists and the general public included the: (1) Effect on quality of patient care; (2) Ability to better monitor patients; (3) Home testing and the doctor-patient relationship; and (4) MM-POC interpretation. Only 34.7% of the general public is willing to pay more than a€10 ($13) for a single MM-POC test, with 85.5% preferring to purchase their MM-POC test from a pharmacy. Conclusion The requirements for the proper implementation of MM-POC were found to be generally similar between medical specialists and POC test kit manufacturers. The general public was much more favorable with respect to a perceived improvement in the quality of healthcare that these tests would bring to the hospital and home environment. PMID:23814465
Kaman, Wendy E; Andrinopoulou, Eleni-Rosalina; Hays, John P
Background Previous studies have reported volatile organic compounds (VOCs) in breath as biomarkers of breast cancer and abnormal mammograms, apparently resulting from increased oxidative stress and cytochrome p450 induction. We evaluated a six-minute point-of-care breath test for VOC biomarkers in women screened for breast cancer at centers in the USA and the Netherlands. Methods 244 women had a screening mammogram (93/37 normal/abnormal) or a breast biopsy (cancer/no cancer 35/79). A mobile point-of-care system collected and concentrated breath and air VOCs for analysis with gas chromatography and surface acoustic wave detection. Chromatograms were segmented into a time series of alveolar gradients (breath minus room air). Segmental alveolar gradients were ranked as candidate biomarkers by C-statistic value (area under curve [AUC] of receiver operating characteristic [ROC] curve). Multivariate predictive algorithms were constructed employing significant biomarkers identified with multiple Monte Carlo simulations and cross validated with a leave-one-out (LOO) procedure. Results Performance of breath biomarker algorithms was determined in three groups: breast cancer on biopsy versus normal screening mammograms (81.8% sensitivity, 70.0% specificity, accuracy 79% (73% on LOO) [C-statistic value], negative predictive value 99.9%); normal versus abnormal screening mammograms (86.5% sensitivity, 66.7% specificity, accuracy 83%, 62% on LOO); and cancer versus no cancer on breast biopsy (75.8% sensitivity, 74.0% specificity, accuracy 78%, 67% on LOO). Conclusions A pilot study of a six-minute point-of-care breath test for volatile biomarkers accurately identified women with breast cancer and with abnormal mammograms. Breath testing could potentially reduce the number of needless mammograms without loss of diagnostic sensitivity. PMID:24599224
Phillips, Michael; Beatty, J. David; Cataneo, Renee N.; Huston, Jan; Kaplan, Peter D.; Lalisang, Roy I.; Lambin, Philippe; Lobbes, Marc B. I.; Mundada, Mayur; Pappas, Nadine; Patel, Urvish
Improved access to anti-retroviral therapy increases the need for affordable monitoring using assays such as CD4 and/or viral load in resource-limited settings. Barriers to accessing treatment, high rates of loss to initiation and poor retention in care are prompting the need to find alternatives to conventional centralized laboratory testing in certain countries. Strong advocacy has led to a rapidly expanding repertoire of point-of-care tests for HIV. point-of-care testing is not without its challenges: poor regulatory control, lack of guidelines, absence of quality monitoring and lack of industry standards for connectivity, to name a few. The management of HIV increasingly requires a multidisciplinary testing approach involving hematology, chemistry, and tests associated with the management of non-communicable diseases, thus added expertise is needed. This is further complicated by additional human resource requirements and the need for continuous training, a sustainable supply chain, and reimbursement strategies. It is clear that to ensure appropriate national implementation either in a tiered laboratory model or a total decentralized model, clear country-specific assessments need to be conducted. PMID:25197773
Stevens, Wendy; Gous, Natasha; Ford, Nathan; Scott, Lesley E
Point-of-care (POC) testing in communities, home settings and primary healthcare centers plays an important role in cutting delays in HIV diagnosis and in the uptake of voluntary testing and counseling. Qualitative research methods have important potential to overcome the current challenges in expanding HIV POC testing programs and strategies, by examining the diagnostic processes, complex inter-relationships and patterns involved in making POC diagnostics work in real-world settings. This article reviews existing qualitative studies on POC testing strategies and programs for HIV. Qualitative research on POC diagnostics around the uptake of POC tests, the actual diagnostic and testing processes involved, the influence of POC tests on clinical decision-making, communication of decisions and decisions exercised by patients are limited. Equally limited are studies that explore adaptation of POC programs to various socio-cultural contexts. More qualitative research is needed to inform test developers, funders and policymakers. PMID:25267607
Engel, Nora; Pant Pai, Nitika
A low-cost, fully integrated sample-to-answer, quantitative PCR (qPCR) system that can be used for detection of HIV-1 proviral DNA in infants at the point-of-care in resource-limited settings has been developed and tested. The system is based on a novel DNA extraction method, which uses a glass fiber membrane, a disposable assay card that includes on-board reagent storage, provisions for thermal cycling and fluorescence detection, and a battery-operated portable analyzer. The system is capable of automated PCR mix assembly using a novel reagent delivery system and performing qPCR. HIV-1 and internal control targets are detected using two spectrally separated fluorophores, FAM and Quasar 670. In this report, a proof-of-concept of the platform is demonstrated. Initial results with whole blood demonstrate that the test is capable of detecting HIV-1 in blood samples containing greater than 5000 copies of HIV-1. In resource-limited settings, a point-of-care HIV-1 qPCR test would greatly increase the number of test results that reach the infants caregivers, allowing them to pursue anti-retroviral therapy. PMID:23202333
Jangam, Sujit R; Agarwal, Abhishek K; Sur, Kunal; Kelso, David M
The results of HPV detection in 550 cervical samples by cervical cytology were compared with the sequencing analysis and HPV genotyping 9G membrane test. The HPV genotyping 9G membrane test can efficiently identify and discriminate five HR-HPV genotypes. The 100% identical results of HPV genotyping 9G membrane tests with the sequencing results in 550 clinical samples ensure its wide clinical applicability. The simple handling steps and the portable scanning device make the HPV genotyping 9G membrane test applicable in point-of-care settings. Moreover, the HPV genotyping 9G membrane test allows one to obtain final results in 30 min at 25 °C by simply loading the hybridization and washing solution and scanning the membranes without any drying steps or special handling. The clinical sensitivity and specificity of the HPV genotyping 9G membrane test was found to be 100%, which is much higher than cervical cytology. PMID:25320905
Song, Keumsoo; Nimse, Satish Balasaheb; An, Heejung; Kim, Taisun
Point-of-care testing (POCT) for the management of patients with diabetes has become a standard of care. Originally, diabetic monitoring was accomplished by manual urine dipsticks. The development of hand-held, battery-operated capillary glucose monitors radically improved the ability of physicians and nurses to monitor diabetic patients during their hospital stay. Capillary glucose meters have been shown to provide accurate results under controlled conditions, but a number of early meters had issues with the quality of testing when used by non-laboratory personnel. Bedside capillary glucose testing was first initiated in our hospital in 1990, using a first-generation glucose meter that could measure a glucose value within 2 min. Operator errors were common because the glucose strips required wiping and the testing required timing. Furthermore, these early meters had no data storage or data management capabilities. In 1995, we transitioned to a second-generation meter with a rudimentary data management and storage capability that could be downloaded to a portable laptop. A log of quality control (QC) data could be derived from the download. A major problem with this device was the need to bring the instruments and laptop together, which was labor intensive and difficult to sustain over long periods of time in a large institution. We recently implemented a third-generation instrument (the Abbott Precision PCx) with a data management system (Precision NET). This device significantly expands the data management and networking capabilities of the bedside glucose meter, as shown in Table 5. Glucose values can now be performed in a fraction of the time of the first-generation meters, the need to wipe the glucose strips has been eliminated, and only certified operators can use the instrument. Networking technology allows for centralized quality control management, and the ability to network with other point-of-care technologies using intranet and in the near future internet applications. Collectively, these developments have radically improved the efficiency and quality of bedside capillary glucose testing, and have significantly enhanced the ability to manage this important technology. PMID:11369354
Lewandrowski, E; Mac Millan, D; Misiano, D; Tochka, L; Lewandrowski, K
Dengue fever, dengue haemorrhagic fever, and dengue shock syndrome (DF/DHF/DSS) are tropical diseases that cause significant humanitarian and economic hardship. It is estimated that more than 2.5 billion people are at risk of infection and more than 100 countries have endemic dengue virus transmission. Laboratory tests are essential to provide an accurate diagnosis of dengue virus infection so that appropriate treatment and patient management may be administered. In many dengue endemic settings, laboratory diagnostic resources are limited and simple rapid diagnostic tests (RDTs) provide opportunities for point-of-care diagnosis. This paper addresses current issues relating to the application of commercial dengue RDTs for the diagnosis of acute dengue virus infection, recent diagnostic evaluations, and identifies future needs. PMID:22654479
Blacksell, Stuart D.
In a point-of-care (POC) setting, it is critically important to reliably count the number of specific cells in a blood sample. Software-based cell counting, which is far faster than manual counting, while much cheaper than hardware-based counting, has emerged as an attractive solution potentially applicable to mobile POC testing. However, the existing software-based algorithm based on the normalized cross-correlation (NCC) method is too time- and, thus, energy-consuming to be deployed for battery-powered mobile POC testing platforms. In this paper, we identify inefficiencies in the NCC-based algorithm and propose two synergistic optimization techniques that can considerably reduce the runtime and, thus, energy consumption of the original algorithm with negligible impact on counting accuracy. We demonstrate that an AndroidTM smart phone running the optimized algorithm consumes 11.5× less runtime than the original algorithm. PMID:25195851
Ahn, DaeHan; Kim, Nam Sung; Moon, SangJun; Park, Taejoon; Son, Sang Hyuk
Objectives Point-of-care (POC) testing for chlamydia (CT) and gonorrhoea (NG) offers a new approach to the diagnosis and management of these sexually transmitted infections (STIs) in remote Australian communities and other similar settings. Diagnosis of STIs in remote communities is typically symptom driven, and for those who are asymptomatic, treatment is generally delayed until specimens can be transported to the reference laboratory, results returned and the patient recalled. The objective of this study was to explore the clinical implications of using CT/NG POC tests in routine clinical care in remote settings. Methods In-depth qualitative interviews were conducted with a purposively selected group of 18 key informants with a range of sexual health and laboratory expertise. Results Participants highlighted the potential impact POC testing would have on different stages of the current STI management pathway in remote Aboriginal communities and how the pathway would change. They identified implications for offering a POC test, specimen collection, conducting the POC test, syndromic management of STIs, pelvic inflammatory disease diagnosis and management, interpretation and delivery of POC results, provision of treatment, contact tracing, management of client flow and wait time, and re-testing at 3 months after infection. Conclusions The introduction of POC testing to improve STI service delivery requires careful consideration of both its advantages and limitations. The findings of this study will inform protocols for the implementation of CT/NG POC testing, and also STI testing and management guidelines. PMID:24956111
Natoli, Lisa; Maher, Lisa; Shephard, Mark; Hengel, Belinda; Tangey, Annie; Badman, Steven G.; Ward, James; Guy, Rebecca J.
Point of care testing for urinary tract Infection in primary care (POETIC): protocol for a randomised controlled trial of the clinical and cost effectiveness of FLEXICULT¿ informed management of uncomplicated UTI in primary care.
BackgroundUrinary tract infections (UTI) are the most frequent bacterial infection affecting women and account for about 15% of antibiotics prescribed in primary care. However, some women with a UTI are not prescribed antibiotics or are prescribed the wrong antibiotics, while many women who do not have a microbiologically confirmed UTI are prescribed antibiotics. Inappropriate antibiotic prescribing unnecessarily increases the risk of side effects and the development of antibiotic resistance, and wastes resources.POETIC is a randomised controlled trial of a Point Of Care Test (POCT) (Flexicult¿) guided UTI management strategy for use in primary care, which may help General Practitioners more effectively decide both whether or not to prescribe antibiotics, and if so, to select the most appropriate antibiotic.Methods/design614 adult female patients will be recruited from four primary care research networks (Wales, England, Spain, the Netherlands) and individually randomised to either POCT guided care or the guideline-informed `standard care¿ arm. Urine and stool samples (where possible) will be obtained at presentation (day 1) and two weeks later for microbiological analysis. All participants will be followed up on the course of their illness and their quality of life, using a 2 week self-completed symptom diary. At 3 months, a primary care notes review will be conducted for evidence of further evidence of treatment failures, recurrence, complications, hospitalisations and health service costs.The primary objective is to compare appropriate antibiotic use on day 3 between the POCT and standard care arms using multi-level logistic regression to produce an odds ratio and associated 95% confidence interval. Costs of the two management approaches will be assessed in terms of the primary outcome.DiscussionAlthough the Flexicult¿ POCT is used in some countries in routine primary care, it¿s clinical and cost effectiveness has never been evaluated in a randomised clinical trial. If shown to be effective, the use of this POCT could benefit individual sufferers and provide evidence for health care authorities to develop evidence based policies to combat the spread and impact of the unprecedented rise of infections caused by antibiotic resistant bacteria in Europe.Trial registration number ISRCTN65200697 (Registered 10 September 2013). PMID:25425162
Bates, Janine; Thomas-Jones, Emma; Pickles, Timothy; Kirby, Nigel; Gal, Micaela; Bongard, Emily; Hood, Kerenza; Francis, Nicolas; Little, Paul; Moore, Michael; Rumsby, Kate; Llor, Carlos; Burgman, Curt; Verheij, Theo; Cohen, David; Wootton, Mandy; Howe, Robin; Butler, Christopher C
The Southern states experience the highest rates of HIV and AIDS in the US, and point-of-care (POC) testing outside of primary care may contribute to status awareness in medically underserved populations in this region. To evaluate POC screening and linkage to care at an urban south site, analyses were performed on a dataset of 3,651 individuals from an integrated rapid-result HIV testing and linkage program to describe this test-seeking cohort and determine trends associated with screening, results, and linkage to care. Four percent of the population had positive results. We observed significant differences by test result for age, race and gender, reported risk behaviors, test location, and motivation for screening. The overall linkage rate was 86%, and we found significant differences for clients who were linked to HIV care versus persons whose linkage could not be confirmed with respect to race and gender, location, and motivation. The linkage rate for POC testing that included a comprehensive intake visit and colocated primary care services for in-state residents was 97%. Additional research on integrated POC screening and linkage methodologies that provide intake services at time of testing is essential for increasing status awareness and improving linkage to HIV care in the US. PMID:24159384
Dougherty, Sarah M.; Ross-Davis, Kelly L.; Raper, James L.
One-step lateral flow test is recommended as the first line screening of syphilis for primary healthcare settings in developing countries. However, it generally shows low sensitivity. We describe here the development of a novel fluorescent POC (Point Of Care) test method to be used for screening for syphilis. The method was designed to combine the rapidness of lateral flow test and sensitiveness of fluorescent method. 50 syphilis-positive specimens and 50 healthy specimens conformed by Treponema pallidum particle agglutination (TPPA) were tested with Quantum Dot-labeled and colloidal gold-labeled lateral flow test strips, respectively. The results showed that both sensitivity and specificity of the quantum dots-based method reached up to 100% (95% confidence interval [CI], 91-100%), while those of the colloidal gold-based method were 82% (95% CI, 68-91%) and 100% (95% CI, 91-100%), respectively. In addition, the naked-eye detection limit of quantum dot-based method could achieve 2 ng/ml of anti-TP47 polyclonal antibodies purified by affinity chromatography with TP47 antigen, which was tenfold higher than that of colloidal gold-based method. In conclusion, the quantum dots were found to be suitable for labels of lateral flow test strip. Its ease of use, sensitiveness and low cost make it well-suited for population-based on-the-site syphilis screening.
Yang, Hao; Li, Ding; He, Rong; Guo, Qin; Wang, Kan; Zhang, Xueqing; Huang, Peng; Cui, Daxiang
The purpose of this article is to review current principles and criteria for obtaining Clinical Laboratory Improvement Amendments of 1988 (CLIA ’88) waiver, identify existing point-of-care (POC) coagulation and hematology technologies, and analyze regulatory challenges regarding CLIA-waiver for those and future devices. CLIA ’88 documentation requires tests performed by laboratories with a Certificate of Waiver to be so simple that the likelihood of erroneous results by the user is negligible, or poses no unreasonable risk of harm to the patient if performed incorrectly as determined by the Secretary of Health and Human Services. “Simple” means that the test uses unprocessed samples, has a direct read-out of test results, does not have specifications for user training, and includes instructions for confirmatory testing when advisable. Currently the CLIA-waived hematology and coagulation POC devices only test for hemoglobin (Hb), hematocrit (Hct), and prothrombin time/international normalized ratio (PT/INR). The problem with these devices is the lack of multiplexing. POC coagulation and hematology devices face challenges for obtaining a waiver. These challenges include the lack of clinical needs assessment, miniturized assays that correct for interfering substances, and assays simple enough to be combined in a multiplex platform. Several scenarios demonstrate how POC coagulation or hematology devices can improve crisis care. Industry should perform needs assessment on clinicians and emergency responders to determine which analytes to incorporate on multiplex POC coagulation and hematology devices, and produce devices that address confounding factors. PMID:23843728
Curtis, Corbin M.; Kost, Gerald J.; Louie, Richard F.; Sonu, Rebecca J.; Ammirati, Erika B.; Sumner, Stephanie
Point-of-care (POC) tests offer potentially substantial benefits for the management of infectious diseases, mainly by shortening the time to result and by making the test available at the bedside or at remote care centres. Commercial POC tests are already widely available for the diagnosis of bacterial and viral infections and for parasitic diseases, including malaria. Infectious diseases specialists and clinical microbiologists should be aware of the indications and limitations of each rapid test, so that they can use them appropriately and correctly interpret their results. The clinical applications and performance of the most relevant and commonly used POC tests are reviewed. Some of these tests exhibit insufficient sensitivity, and should therefore be coupled to confirmatory tests when the results are negative (e.g. Streptococcus pyogenes rapid antigen detection test), whereas the results of others need to be confirmed when positive (e.g. malaria). New molecular-based tests exhibit better sensitivity and specificity than former immunochromatographic assays (e.g. Streptococcus agalactiae detection). In the coming years, further evolution of POC tests may lead to new diagnostic approaches, such as panel testing, targeting not just a single pathogen, but all possible agents suspected in a specific clinical setting. To reach this goal, the development of serology-based and/or molecular-based microarrays/multiplexed tests will be needed. The availability of modern technology and new microfluidic devices will provide clinical microbiologists with the opportunity to be back at the bedside, proposing a large variety of POC tests that will allow quicker diagnosis and improved patient care. PMID:20670287
Clerc, O; Greub, G
In this paper, we present a low cost and equipment-free blood filtration device capable of producing plasma from blood samples with mL-scale capacity and demonstrate its clinical application for hepatitis B diagnosis. We report the results of in-field testing of the device with 0.8-1?ml of undiluted, anticoagulated human whole blood samples from patients at the National Hospital for Tropical Diseases in Hanoi, Vietnam. Blood cell counts demonstrate that the device is capable of filtering out 99.9% of red and 96.9% of white blood cells, and the plasma collected from the device contains lower red blood cell counts than plasma obtained from a centrifuge. Biochemistry and immunology testing establish the suitability of the device as a sample preparation unit for testing alanine transaminase (ALT), aspartate transaminase (AST), urea, hepatitis B "e" antigen (HBeAg), hepatitis B "e" antibody (HBe Ab), and hepatitis B surface antibody (HBs Ab). The device provides a simple and practical front-end sample processing method for point-of-care microfluidic diagnostics, enabling sufficient volumes for multiplexed downstream tests. PMID:24404044
Gong, Max M; Macdonald, Brendan D; Vu Nguyen, Trung; Van Nguyen, Kinh; Sinton, David
Objective To identify strategies with tactics that enable point-of-care (POC) testing (medical testing at or near the site of care) to improve outcomes effectively in emergencies, disasters, and public health crises, especially where community infrastructure is compromised. Design Logic model-critical path-feedback identified needs for improving practices. Reverse stress analysis showed POC should be integrated, responders properly trained, and devices staged in small-world networks (SWNs). We summarize first responder POC resources, strategize test clusters, address assay environmental vulnerabilities, and design tactics useful for SWNs, alternate care facilities, shelters, point-of-distribution centers, and community hospitals. Participants and Environment Emergency-disaster needs assessment survey respondents and Center experience. Outcomes Important tactics are: a) develop training/education courses and “just-in-time” on-line web resources to assure the competency of POC coordinators and high quality testing performance; b) protect equipment from environmental extremes by sealing reagents, controlling temperature and humidity to which they are exposed, and establishing near-patient testing in defined environments that operate within current FDA licensing claims (illustrated with HIV-1/2 tests); c) position testing in defined sites within SWNs and other environments; d) harden POC devices and reagents to withstand wider ranges of environmental extremes in field applications; e) promote new POC technologies for pathogen detection and other assays, per needs assessment results; and f) select tests according to mission objectives and value propositions. Conclusions Careful implementation of POC testing will facilitate evidence-based triage, diagnosis, treatment, and monitoring of victims and patients, while advancing standards of care in emergencies and disasters, as well as public health crises. PMID:22338316
Kost, Gerald J.; Sakaguchi, Ann; Curtis, Corbin; Tran, Nam K.; Katip, Pratheep; Louie, Richard F.
We assessed the technical performance and robustness of the point-of-care test for C-reactive protein (CRP) NycoCard CRP for use in forensic autopsy cases. The results of 17 of 39 cadaver blood samples that had CRP in the range effectively measured by the NycoCard (5-120mg/l) correlated well (r=0.99) with those of quantitative latex agglutination immunoassay (turbidimetry), and the out-of-range NycoCard results were fully consistent with those obtained by turbidimetry. For the ten sera whose CRP >120mg/l according to NycoCard, a significant correlation (r=0.98) was observed between values multiplied by the dilution ratio and those of turbidimetry. No significant differences were observed after a freeze-thaw procedure. In addition, CRP results using recombinant human CRP spiked with hemoglobin up to 80g/l were not significantly different from the unspiked results in PBS. The test allows reliable and cost-effective on-site measurement of CRP from a small volume of serum (5?l) with simple equipment. This semi-quantification method of CRP should be useful for diagnosis during autopsy. PMID:24530941
Soejima, Mikiko; Koda, Yoshiro
BACKGROUND. Anemia, or low blood hemoglobin (Hgb) levels, afflicts 2 billion people worldwide. Currently, Hgb levels are typically measured from blood samples using hematology analyzers, which are housed in hospitals, clinics, or commercial laboratories and require skilled technicians to operate. A reliable, inexpensive point-of-care (POC) Hgb test would enable cost-effective anemia screening and chronically anemic patients to self-monitor their disease. We present a rapid, stand-alone, and disposable POC anemia test that, via a single drop of blood, outputs color-based visual results that correlate with Hgb levels. METHODS. We tested blood from 238 pediatric and adult patients with anemia of varying degrees and etiologies and compared hematology analyzer Hgb levels with POC Hgb levels, which were estimated via visual interpretation using a color scale and an optional smartphone app for automated analysis. RESULTS. POC Hgb levels correlated with hematology analyzer Hgb levels (r = 0.864 and r = 0.856 for visual interpretation and smartphone app, respectively), and both POC test methods yielded comparable sensitivity and specificity for detecting any anemia (n = 178) (<11 g/dl) (sensitivity: 90.2% and 91.1%, specificity: 83.7% and 79.2%, respectively) and severe anemia (n = 10) (<7 g/dl) (sensitivity: 90.0% and 100%, specificity: 94.6% and 93.9%, respectively). CONCLUSIONS. These results demonstrate the feasibility of this POC color-based diagnostic test for self-screening/self-monitoring of anemia. TRIAL REGISTRATION. Not applicable. FUNDING. This work was funded by the FDA-funded Atlantic Pediatric Device Consortium, the Georgia Research Alliance, Children’s Healthcare of Atlanta, the Georgia Center of Innovation for Manufacturing, and the InVenture Prize and Ideas to Serve competitions at the Georgia Institute of Technology. PMID:25157824
Tyburski, Erika A.; Gillespie, Scott E.; Stoy, William A.; Mannino, Robert G.; Weiss, Alexander J.; Siu, Alexa F.; Bulloch, Rayford H.; Thota, Karthik; Cardenas, Anyela; Session, Wilena; Khoury, Hanna J.; O’Connor, Siobhán; Bunting, Silvia T.; Boudreaux, Jeanne; Forest, Craig R.; Gaddh, Manila; Leong, Traci; Lyon, L. Andrew; Lam, Wilbur A.
Point-of-care (POC) testing is increasingly applied as a cost effective alternative to many diagnostic tests. Key in POC testing is to create sufficient assay sensitivity with relatively low cost reagents and equipment. For this purpose we have employed a unique reporter, upconverting phosphor (UCP) particles, in combination with lateral flow (LF) assays. UCPs, submicron ceramic particles doped with rare earth ions (lanthanides), convert infrared to visible light and do not suffer from autofluorescence which limits conventional fluorescence based assays. Low cost handheld readers and microfluidics were evaluated in various applications. Designed assays are well suited for applications outside diagnostic laboratories, in resource poor settings, and can even be used by patients at home. Using two distinctly different UCP-LF assay formats, we focussed on assays for infectious diseases based on the detection of pathogen-specific antibodies and/or antigens including nucleic acids to demonstrate active infection with HIV. Only minor adaptation of the standard UCP-LF assay format is needed to render the format suitable for applications involving low affinity capture antibodies (e.g. in the detection of neurotoxin, botulism), capture of small molecules (e.g. detection of melatonin, a key hormone in chronopharmacology) or the use of dry UCP reagents (e.g. detection of protein based fruit-ripening markers, of economic interest in agriculture). Finally, we anticipate on developments in healthcare (personalized medicine) by discussing the potential of one of the UCP-LF assay formats to measure serum trough levels of immunodrugs (e.g. infliximab or adalimumab) in patients treated for inflammatory bowel disease and rheumatoid arthritis.
Tanke, Hans J.; Zuiderwijk, Michel; Wiesmeijer, Karien C.; Breedveld, Robert N.; Abrams, William R.; de Dood, Claudia J.; Tjon Kon Fat, Elisa M.; Corstjens, Paul L. A. M.
Introduction Point-of-care testing for CD4 cell count is considered a promising way of reducing the time to eligibility assessment for antiretroviral therapy (ART) and of increasing retention in care prior to treatment initiation. In this review, we assess the available evidence on the patient and programme impact of point-of-care CD4 testing. Methods We searched nine databases and two conference sites (up until 26 October 2013) for studies reporting patient and programme outcomes following the introduction of point-of-care CD4 testing. Where appropriate, results were pooled using random-effects methods. Results Fifteen studies, mainly from sub-Saharan Africa, were included for review, providing evidence for adults, adolescents, children and pregnant women. Compared to conventional laboratory-based testing, point-of-care CD4 testing increased the likelihood of having CD4 measured [odds ratio (OR) 4.1, 95% CI 3.5–4.9, n=2] and receiving a CD4 result (OR 2.8, 95% CI 1.5–5.6, n=6). Time to being tested was significantly reduced, by a median of nine days; time from CD4 testing to receiving the result was reduced by as much as 17 days. Evidence for increased treatment initiation was mixed. Discussion The results of this review suggest that point-of-care CD4 testing can increase retention in care prior to starting treatment and can also reduce time to eligibility assessment, which may result in more eligible patients being initiated on ART. PMID:24447595
Wynberg, Elke; Cooke, Graham; Shroufi, Amir; Reid, Steven D; Ford, Nathan
Background Hemoglobin A1c monitoring is routine care for patients with diabetes and may be obtained as often as every 3 months. Most family practice clinics are not equipped to evaluate a hemoglobin A1c result in the office. Obtaining a hemoglobin A1c result from a central laboratory can result in a delay, added expense, and inconvenience for the patient. To date, there are no published studies on the accuracy of the A1CNow+™, a point-of-care hemoglobin A1c monitoring device. Methods Seventy patients having type 1 or type 2 diabetes were enrolled from three pharmacy-managed diabetes clinics. Subjects were required to have a venous blood draw within 1 week of the point-of-care test. The study then evaluated the statistical and clinical significance between both tests. Results A good correlation was seen between the A1CNow+ and laboratory values with a correlation coefficient of r = 0.893. The best correlation between the A1CNow+ and the laboratory was seen among hemoglobin A1c values in the range of 7–8.5%. Conclusion The access of the A1CNow+ device at point of care makes a hemoglobin A1c evaluation economically and therapeutically beneficial after proving its accuracy in a primary care setting. Advantages of this device may go beyond convenience and economic benefit by allowing patients to acknowledge their level of glucose control at the point of care and to be counseled appropriately. PMID:19885267
Arrendale, Justin R.; Cherian, Sonia E.; Zineh, Issam; Chirico, Mark J.; Taylor, James R.
Chemiluminescent reactions have found application in a number of commercial point-of-care and on-site testing devices. Notable examples include allergy tests (e.g., MASTpette, OPTIGEN® systems), flu tests (e.g., ZstatFlu®-II), cartridge-based immunoassay systems (FastPack® IP System, PATHFAST®), forensic tests for bloodstains, portable analyzers for biochip array assays (Evidence MultiStat), water quality tests (Eclox), air pollutants (e.g., oxides of nitrogen), and handheld devices for detecting explosives (e.g., E3500 Chemilux®). Many other point-of-care or on-site testing devices with a chemiluminescent end point have been devised on the basis of a variety of formats (e.g., cuvette, cassette, dipstick, test strip, microchip), but most have not progressed beyond a proof-of-principle or prototype stage. PMID:24658468
Park, Jason Y; Kricka, Larry J
The U.S. Institute of Medicine (IOM) much publicized report in “To Err is Human” (2000, National Academy Press) stated that as many as 98 000 hospitalized patients in the U.S. die each year due to preventable medical errors. This revelation about medical error and patient safety focused the public and the medical community's attention on errors in healthcare delivery including laboratory and point-of-care-testing (POCT). Errors introduced anywhere in the POCT process clearly can impact quality and place patient's safety at risk. While POCT performed by or near the patient reduces the potential of some errors, the process presents many challenges to quality with its multiple tests sites, test menus, testing devices and non-laboratory analysts, who often have little understanding of quality testing. Incoherent or no regulations and the rapid availability of test results for immediate clinical intervention can further amplify errors. System planning and management of the entire POCT process are essential to reduce errors and improve quality and patient safety. PMID:21808107
Ehrmeyer, Sharon S.
In Peru, a significant proportion of people tested for HIV and syphilis do not receive timely results. Our objective was to assess the institutional feasibility of implementing simultaneous HIV/syphilis point-of-care tests and client perceptions regarding these point-of-care tests. Point-of-care tests were implemented in a hospital consultation room in a marginalised zone of Lima. A time-series design was used to compare the proportion of tested clients who received timely results, with and without the point-of-care test intervention. Experience and satisfaction with point-of-care tests was evaluated with 149 people. In the 6 months without intervention, 69% and 61% of clients tested for HIV and syphilis, respectively, received their results within the required 45-minute window. During the 2-month point-of-care test intervention, all clients tested for HIV (n?=?387) and syphilis (n?=?398) received their results within 45?minutes. All clients surveyed were completely satisfied (52%) or satisfied (48%) with the simultaneous HIV/syphilis point-of-care test screening process. Additionally, 73% strongly agreed with the statement 'I feel satisfied with the rapid testing process.' Screening using point-of-care tests represents an important opportunity to reduce the time, resource and cost burden for users and institutions and increase the proportion of users receiving their test results in a timely manner. PMID:25258394
Flores, Elaine C; Lluque, Maria E; Chiappe, Marina; Lino, Rosabel; Bayer, Angela M
Introduction Hemoglobin concentration is assessed to detect anemia and its associated morbidities. Hemoglobin is usually determined from venous or capillary blood samples run on a laboratory analyzer. However, this method requires a needle stick and results can be delayed. It also exposes caregivers to risks associated with needle sticks and blood exposure. Noninvasive hemoglobin determination would be of benefit to patients and caregivers because it would allow for quick and painless point-of-care assessment. Methods Hemoglobin determination from a noninvasive spot check hemoglobin device (Pronto-7 with SpHb, Masimo) and an invasive point-of-care device (HemoCue) was compared with venous blood samples run on a laboratory hematology analyzer. Results A total of 440 outpatients and healthy volunteers were included (mean age 36 years, 62% female). Compared with the hematology analyzer, the bias ± standard deviation of was ?0.1 ± 1.1 g/dL for SpHb and ?0.1 ± 1.6 g/dL for HemoCue. Conclusion Noninvasive hemoglobin testing with SpHb provided similar accuracy as invasive point-of-care hemoglobin testing and may enable more efficient and effective patient care. PMID:23809685
Shah, N; Osea, E A; Martinez, G J
Background An integrated tiered service delivery model (ITSDM) has been proposed to provide ‘full-coverage’ of CD4 services throughout South Africa. Five tiers are described, defined by testing volumes and number of referring health-facilities. These include: (1) Tier-1/decentralized point-of-care service (POC) in a single site; Tier-2/POC-hub servicing processing <30–40 samples from 8–10 health-clinics; Tier-3/Community laboratories servicing ?50 health-clinics, processing <150 samples/day; high-volume centralized laboratories (Tier-4 and Tier-5) processing <300 or >600 samples/day and serving >100 or >200 health-clinics, respectively. The objective of this study was to establish costs of existing and ITSDM-tiers 1, 2 and 3 in a remote, under-serviced district in South Africa. Methods Historical health-facility workload volumes from the Pixley-ka-Seme district, and the total volumes of CD4 tests performed by the adjacent district referral CD4 laboratories, linked to locations of all referring clinics and related laboratory-to-result turn-around time (LTR-TAT) data, were extracted from the NHLS Corporate-Data-Warehouse for the period April-2012 to March-2013. Tiers were costed separately (as a cost-per-result) including equipment, staffing, reagents and test consumable costs. A one-way sensitivity analyses provided for changes in reagent price, test volumes and personnel time. Results The lowest cost-per-result was noted for the existing laboratory-based Tiers- 4 and 5 ($6.24 and $5.37 respectively), but with related increased LTR-TAT of >24–48 hours. Full service coverage with TAT <6-hours could be achieved with placement of twenty-seven Tier-1/POC or eight Tier-2/POC-hubs, at a cost-per-result of $32.32 and $15.88 respectively. A single district Tier-3 laboratory also ensured ‘full service coverage’ and <24 hour LTR-TAT for the district at $7.42 per-test. Conclusion Implementing a single Tier-3/community laboratory to extend and improve delivery of services in Pixley-ka-Seme, with an estimated local ?12–24-hour LTR-TAT, is ?$2 more than existing referred services per-test, but 2–4 fold cheaper than implementing eight Tier-2/POC-hubs or providing twenty-seven Tier-1/POCT CD4 services. PMID:25517412
Cassim, Naseem; Coetzee, Lindi M.; Schnippel, Kathryn; Glencross, Deborah K.
Analyte quantification in highly scattering media such as tissue, blood, and other biological fluids is challenging using conventional spectroscopic methods. Ultrasound easily penetrates these opaque samples, yet currently provides little chemical information. We have developed a general approach for creating hydrogel biosensors based on antibody-linked cellulose polymers. Target recognition induces changes to the sensor stiffness and size, which is accompanied by characteristic changes to a measured ultrasonic frequency profile. Using this technique, nM sensitivity for acetaminophen is demonstrated in a series of biofluids including whole blood, blood plasma, saliva, and urine. Likewise, this methodology is attractive for point of care diagnostics due to the short measurement time, simple methodology which excludes pretreatment of samples, and has minimal chemical or buffer requirements. PMID:21238722
Dion, Jonathan R; Burns, David H
Point-of-care testing (POCT) is one of the formidable concept introduce in the field of critical care settings to deliver decentralized, patient-centric health care to the patients. Rapid provision of blood measurements, particularly blood gases and electrolytes, may translate into improved clinical outcomes. Studies shows that POCT carries advantages of providing reduced therapeutic turnaround time (TTAT), shorter door-to-clinical-decision time, rapid data availability, reduced preanalytic and postanalytic testing errors, self-contained user-friendly instruments, small sample volume requirements, and frequent serial whole-blood testing. However, still there is a noticeable debate that exists among the laboratorians, clinicians, and administrators over concerns regarding analyzer inaccuracy, imprecision and performance (interfering substances), poorly trained non-laboratorians, high cost of tests, operator-dependent quality of testing, and difficulty in integrating test results with hospital information system (HIS). On search of literature using Medline/Pubmed and Embase using the key phrases “ppoint-of-care test,” “central laboratory testing,” “electrolytes,” “blood gas analysis,” “lactate,” “emergency department,” “intensive care unit,” we found that POCT of blood gases and selected electrolytes may not entirely replace centralized laboratory testing but may transfigure the clinical practice paradigm of emergency and critical care physicians. We infer that further comprehensive, meaningful and rigorous evaluations are required to determine outcomes which are more quantifiable, closely related to testing events and are associated with effective cost benefits. PMID:25337483
Kapoor, Dheeraj; Srivastava, Meghana; Singh, Pritam
Self-reported information about smoking habit and cigarette consumption can be inaccurate and subject to bias in the clinical setting. Accurate assessment of a given smoking history at point-of-care is valuable. We describe the use of a comprehensive smoking questionnaire and the use of a disposable biomarker test to verify and quantify the exposure to tobacco smoke. This point-of-care test (SmokeScreen) is a 6-min, easy-to-use urine test that measures nicotine and its breakdown products. One hundred consecutive patients attending plastic surgery pre-assessment clinic filled in the questionnaire and gave a consented urine sample. Qualitative and semi-quantitative assessment of tobacco consumption was observed by a simple sample colour change set against a standardised colorimetric chart for nicotine metabolite containing urine. The questionnaire self-reported smoking prevalence was 30% with 98% test specificity. The cotinine validated smoking prevalence was 54% with a 26% self-denial rate. Half the patients (n = 15) who admitted smoking on the questionnaire underreported the amount they smoked daily, as quantified by biochemical measurement. Objective biochemical assessment shows that 26% of self-reporting non-smokers via self-completed questionnaire studies are actual smokers attending this pre-assessment clinic. When patients did report smoking there was consistent underreporting of cigarette consumption. PMID:17046624
Payne, C E; Southern, S J
The design of a novel therapeutic drug monitoring (TDM) point-of-care-testing (POCT) biochip for immunosuppressants detection in transplanted patients is described. The chip consists of two polymeric parts, a top PMMA slide and a bottom ZEONOR® thin foil, bonded together by means of a pressure sensitive adhesive tape. The tape, with lower refractive index, is shaped in order to obtain a microfluidic multi-channel array. The optical signal, coming from an external light source and travelling along the ZEONOR® thin foil, excites the fluorescent sensing layer immobilized onto the fluidic channels. Preliminary tests with the bioassay implementation for tacrolimus detection are reported.
Berrettoni, C.; Trono, C.; Berneschi, S.; Giannetti, A.; Tombelli, S.; Bernini, R.; Grimaldi, A.; Persichetti, G.; Testa, G.; Bolzoni, L.; Porro, G.; Becker, H.; Gärtner, C.; Baldini, F.
Medical errors are a major concern in health care today. Errors in point-of-care testing (POCT) are particularly problematic because the test is conducted by clinical operators at the site of patient care and immediate medical action is taken on the results prior to review by the laboratory. The Performance Improvement Program at Baystate Health System, Springfield, Massachusetts, noted a number of identification errors occurring with glucose and blood gas POCT devices. Incorrect patient account numbers that were attached to POCT results prevented the results from being transmitted to the patient's medical record and appropriately billed. In the worst case, they could lead to results being transferred to the wrong patient's chart and inappropriate medical treatment. Our first action was to lock-out operators who repeatedly made identification errors (3-Strike Rule), requiring operators to be counseled and retrained after their third error. The 3-Strike Rule significantly decreased our glucose meter errors (p = 0.014) but did not have an impact on the rate of our blood gas errors (p = 0.378). Neither device approached our ultimate goal of zero tolerance. A Failure Mode and Effects Analysis (FMEA) was conducted to determine the various processes that could lead to an identification error. A primary source of system failure was the manual entry of 14 digits for each test, five numbers for operator and nine numbers for patient account identification. Patient barcoding was implemented to automate the data entry process, and after an initial familiarization period, resulted in significant improvements in error rates for both the glucose (p = 0.0007) and blood gas devices (p = 0.048). Despite the improvements, error rates with barcoding still did not achieve zero errors. Operators continued to utilize manual data entry when the barcode scan was unsuccessful or unavailable, and some patients were found to have incorrect patient account numbers due to hospital transfer, multiple wristbands on a single patient, and selection of expired account numbers from previous hospitalizations when printing the barcoded wristbands. Barcoding can thus improve the incidence of identification errors, but hospitals need to take additional steps to ensure successful barcode scanning and to verify that patient wristbands contain correct information. Implementation of patient barcoding was successful in significantly reducing identification errors with POCT, improving patient care, and enhancing interdisciplinary communication. PMID:15597554
Nichols, James H; Bartholomew, Cathy; Brunton, Mary; Cintron, Carlos; Elliott, Sheila; McGirr, Joan; Morsi, Deborah; Scott, Sue; Seipel, Joseph; Sinha, Daisy
Background User-friendly, accurate, point-of-care rapid tests to detect glucose-6-phosphate dehydrogenase deficiency (G6PDd) are urgently needed at peripheral level to safely recommend primaquine for malaria elimination. Methods The CareStart G6PD RDT (AccessBio, New Jersey, USA), a novel rapid diagnostic test and the most commonly used test, the fluorescent spot test (FST) were assessed against the quantitatively measured G6PD enzyme activity for detecting G6PDd. Subjects were healthy males and non-pregnant females aged 18 years or older residing in six villages in Pailin Province, western Cambodia. Findings Of the 938 subjects recruited, 74 (7.9%) were severe and moderately severe G6PD deficient (enzyme activity <30%), mostly in male population; population median G6PD activity was 12.0 UI/g Hb. The performances of the CareStart G6PD RDT and the FST, according to different cut-off values used to define G6PDd were very similar. For the detection of severe and moderately severe G6PDd (enzyme activity <30%, <3.6 UI/g Hb) in males and females, sensitivity and negative (normal status) predictive value were 100% for both point-of-care tools. When the G6PDd cut-off value increased (from <40% to <60%), the sensitivity for both PoCs decreased: 93.3% to 71.7% (CareStart G6PD RDT, p?=?10?6) and 95.5% to 73.2% (FST, p?=?10?6) while the specificity for both PoCs remained similar: 97.4% to 98.3% (CareStart G6PD RDT, p?=?0.23) and 98.7% to 99.6% (FST, p?=?0.06). The cut-off values for classifying individuals as normal were 4.0 UI/g Hb and 4.3 UI/g Hb for the CareStart G6PD RDT and the FST, respectively. Conclusions The CareStart G6PD RDT reliably detected moderate and severe G6PD deficient individuals (enzyme activity <30%), suggesting that this novel point-of-care is a promising tool for tailoring appropriate primaquine treatment for malaria elimination by excluding individuals with severe G6PDd for primaquine treatment. PMID:25541721
Roca-Feltrer, Arantxa; Khim, Nimol; Kim, Saorin; Chy, Sophy; Canier, Lydie; Kerleguer, Alexandra; Tor, Pety; Chuor, Char Meng; Kheng, Sim; Siv, Sovannaroth; Kachur, Patrick S.; Taylor, Walter R. J.; Hwang, Jimee; Menard, Didier
Overcrowding of the emergency department (ED) is rapidly becoming a global challenge and a major source of concern for emergency physicians. The evaluation of cardiac biomarkers is critical for confirming diagnoses and expediting treatment decisions to reduce overcrowding, however, physicians currently face the dilemma of choosing between slow and accurate central-based laboratory tests, or faster but imprecise assays. With improvements in technology, point-of-care testing (POCT) systems facilitate the efficient and high-throughput evaluation of biomarkers, such as troponin (cTn), brain natriuretic peptide (BNP) and neutrophil gelatinase-associated lipocalin (NGAL). In this context, POCT may help ED physicians to confirm a diagnosis of conditions, such as acute coronary syndrome, heart failure or kidney damage. Compared with classic laboratory methods, the use of cTn, BNP, and NGAL POCT has shown comparable sensitivity, specificity and failure rate, but with the potential to provide prompt and accurate diagnosis, shorten hospital stay, and alleviate the burden on the ED. Despite this potential, the full advantages of rapid delivery results will only be reached if POCT is implemented within hospital standardized procedures and ED staff receive appropriate training. PMID:24864300
Di Somma, Salvatore; Zampini, Giorgio; Vetrone, Francesco; Soto-Ruiz, Karina M; Magrini, Laura; Cardelli, Patrizia; Ronco, Claudio; Maisel, Alan; Peacock, Frank W
Background A commercially available self-test for the detection of Borrelia burgdorferi sensu lato in ticks was evaluated for its ability to predict erythema migrans formation. Findings The self-test was performed on 127 Ixodes ricinus from 122 humans that reported tick bites at enrolment and occurrence of symptoms during follow-up. The self-test gave negative results on all the 122 individuals, 14 of whom reported erythema migrans (EM) at follow-up of which 10 were confirmed by their GP. The estimated sensitivity of the self-test for prediction of EM formation is 0% (95% CI: 0%-28%). Conclusions This self-test is not suitable for reducing the number needed to treat in a post-exposure prophylaxis setting as it already missed all the obvious early Lyme borreliosis cases. PMID:24304944
Point-of-care testing (POCT) is applicable in the immediate vicinity of the patient, where timely diagnosis or prognostic information could help doctors decide the following treatment. Among types of developed POCT, gold nanoparticle based lateral flow strip technology provides advantages such as simple operation, cost-effectiveness, and a user-friendly platform. Therefore, this type of POCT is most likely to be used in battlefields and developing countries. However, conventional lateral flow strips suffer from low detection limits. Although enzyme-linked amplification was demonstrated to improve the detection limit and sensitivity by stronger visible lines or by permitting electrochemical analytical instrumentation, the enzyme labels have potential to cause interference with other enzymes in our body fluids. To eliminate this limitation, we developed an amplification-free gold nanoparticle-based immunosensor applied for detecting collagen type V, which is produced or released abnormally during rejection of lung transplants and sulfur mustard exposure. By using suitable blocking protein to stabilize gold nanoparticles as the reporter probe, a low detection limit of ng/ml was achieved. This strategy is a promising platform for clinical POCT, with potential applications in military or disaster response.
Chung, Pei-Yu; Bracho-Sanchez, Evelyn R.; Jiang, Peng; Seagrave, JeanClare; Duncan, Matthew R.; Grotendorst, Gary R.; Schultz, Gregory; Batich, Christopher
In recent years, there has been significant investment from both the private and public sectors in the development of diagnostic technologies to meet the need for human immunodeficiency virus (HIV) and tuberculosis testing in low-resource settings. Future investments should ensure that the most appropriate technologies are adopted in settings where they will have a sustainable impact. Achieving these aims requires the involvement of many stakeholders, as their needs, operational constraints, and priorities are often distinct. Here, we discuss these considerations from different perspectives representing those of various stakeholders involved in the development, introduction, and implementation of diagnostic tests. We also discuss some opportunities to address these considerations. PMID:22402038
Palamountain, Kara M.; Baker, Jeff; Cowan, Elliot P.; Essajee, Shaffiq; Mazzola, Laura T.; Metzler, Mutsumi; Schito, Marco; Stevens, Wendy S.; Young, Gloria J.
We describe a point-of-care immunochromatographic test for the simultaneous detection of both nontreponemal and treponemal antibodies in the sera of patients with syphilis that acts as both a screening and a confirmatory test. A total of 1,601 banked serum samples were examined by the dual test, and the results were compared to those obtained using a quantitative rapid plasma reagin (RPR) test and the Treponema pallidum passive particle agglutination (TP-PA) assay. Compared to the RPR test, the reactive concordance of the dual test nontreponemal line was 98.4% when the RPR titers of sera were ?1:2 and the nonreactive concordance was 98.6%. Compared to the TP-PA assay, the reactive and nonreactive concordances of the treponemal line were 96.5% and 95.5%, respectively. These results indicate that the dual test could be used for the serological diagnosis of syphilis in primary health care clinics or resource-poor settings and therefore improve rates of treatment where patients may fail to return for their laboratory results. PMID:20881177
Castro, Arnold R.; Esfandiari, Javan; Kumar, Shailendra; Ashton, Matthew; Kikkert, Susan E.; Park, Mahin M.; Ballard, Ronald C.
Laboratory-based CD4 monitoring of HIV patients presents challenges in resource limited settings (RLS) including frequent machine breakdown, poor engineering support and limited cold chain and specimen transport logistics. This study assessed the performance of two CD4 tests designed for use in RLS; the Dynal assay and the Alere PIMA test (PIMA). Accuracy of Dynal and PIMA using venous blood was assessed in a centralised laboratory by comparison to BD FACSCount (BD FACS). Dynal had a mean bias of -50.35 cells/µl (r2?=?0.973, p<0.0001, n?=?101) and PIMA -22.43 cells/µl (r2?=?0.964, p<0.0001, n?=?139) compared to BD FACS. Similar results were observed for PIMA operated by clinicians in one urban (n?=?117) and two rural clinics (n?=?98). Using internal control beads, PIMA precision was 10.34% CV (low bead mean 214.24 cells/µl) and 8.29% (high bead mean 920.73 cells/µl) and similar %CV results were observed external quality assurance (EQA) and replicate patient samples. Dynal did not perform using EQA and no internal controls are supplied by the manufacturer, however duplicate testing of samples resulted in r2?=?0.961, p<0.0001, mean bias?=?-1.44 cells/µl. Using the cut-off of 350 cells/µl compared to BD FACS, PIMA had a sensitivity of 88.85% and specificity of 98.71% and Dynal 88.61% and 100%. A total of 0.44% (2/452) of patient samples were misclassified as "no treat" and 7.30% (33/452) "treat" using PIMA whereas with Dynal 8.91% (9/101) as "treat" and 0% as "no treat". In our setting PIMA was found to be accurate, precise and user-friendly in both laboratory and clinic settings. Dynal performed well in initial centralized laboratory evaluation, however lacks requisite quality control measures, and was technically more difficult to use, making it less suitable for use at lower tiered laboratories. PMID:25426710
Malagun, Malin; Nano, Gideon; Chevallier, Caroline; Opina, Ragagalo; Sawiya, Gola; Kivavia, Joseph; Kalinoe, Albina; Nathaniel, Kathalina; Kaminiel, Oscillah; Millan, John; Carmone, Andrea; Dini, Mary; Palou, Theresa; Topma, Kum; Lavu, Evelyn; Markby, Jessica
Laboratory-based CD4 monitoring of HIV patients presents challenges in resource limited settings (RLS) including frequent machine breakdown, poor engineering support and limited cold chain and specimen transport logistics. This study assessed the performance of two CD4 tests designed for use in RLS; the Dynal assay and the Alere PIMA test (PIMA). Accuracy of Dynal and PIMA using venous blood was assessed in a centralised laboratory by comparison to BD FACSCount (BD FACS). Dynal had a mean bias of ?50.35 cells/µl (r2?=?0.973, p<0.0001, n?=?101) and PIMA ?22.43 cells/µl (r2?=?0.964, p<0.0001, n?=?139) compared to BD FACS. Similar results were observed for PIMA operated by clinicians in one urban (n?=?117) and two rural clinics (n?=?98). Using internal control beads, PIMA precision was 10.34% CV (low bead mean 214.24 cells/µl) and 8.29% (high bead mean 920.73 cells/µl) and similar %CV results were observed external quality assurance (EQA) and replicate patient samples. Dynal did not perform using EQA and no internal controls are supplied by the manufacturer, however duplicate testing of samples resulted in r2?=?0.961, p<0.0001, mean bias?=??1.44 cells/µl. Using the cut-off of 350 cells/µl compared to BD FACS, PIMA had a sensitivity of 88.85% and specificity of 98.71% and Dynal 88.61% and 100%. A total of 0.44% (2/452) of patient samples were misclassified as “no treat” and 7.30% (33/452) “treat” using PIMA whereas with Dynal 8.91% (9/101) as “treat” and 0% as “no treat”. In our setting PIMA was found to be accurate, precise and user-friendly in both laboratory and clinic settings. Dynal performed well in initial centralized laboratory evaluation, however lacks requisite quality control measures, and was technically more difficult to use, making it less suitable for use at lower tiered laboratories. PMID:25426710
Malagun, Malin; Nano, Gideon; Chevallier, Caroline; Opina, Ragagalo; Sawiya, Gola; Kivavia, Joseph; Kalinoe, Albina; Nathaniel, Kathalina; Kaminiel, Oscillah; Millan, John; Carmone, Andrea; Dini, Mary; Palou, Theresa; Topma, Kum; Lavu, Evelyn; Markby, Jessica
Background Neonates routinely receive vitamin K to prevent vitamin K deficiency bleeding, which is associated with a high mortality rate and a high frequency of neurological sequelae. A coagulation screening test might be necessary to detect prophylactic failure or incomplete prophylaxis. However, venous access and the volume of blood required for such testing can be problematic. CoaguChek XS is a portable device designed to monitor prothrombin time while only drawing a small volume of blood. Although the device is used in adults and children, studies have not been performed to evaluate its clinical utility in neonates, and the reference value is unknown in this population. The objectives of the present study were to determine the reference intervals (RIs) for international normalized ratio (INR) using the CoaguChek XS by capillary puncture in healthy term neonates, to evaluate factors that correlate with INR, and to evaluate the device by assessing its ease of use in clinical practice. Methods This study included 488 healthy term neonates born at a perinatal center between July 2012 and June 2013. The INRs determined by CoaguChek XS were measured in 4-day-old neonates. Results The enrolled neonates were orally administered vitamin K 6-12 h after birth. A RI for INRs in 4-day-old neonates was established using the CoaguChek XS with a median value of 1.10 and a range of 0.90–1.30. A significant difference in the INR was noted between male (median value, 1.10; RI, 0.90–1.30) and female (median value, 1.10; RI, 0.90–1.24) neonates (p?=?0.049). The INR was found to correlate with gestational age, birth weight, and hematocrit value. Conclusions The CoaguChek XS device is safe, fast, and convenient for performing INR assays in neonates. Our study is the first to establish a RI for INRs that were measured using the CoaguChek XS in healthy term neonates. PMID:25008798
Objective: Determine the percentage of subjects taking antipsychotics who meet criteria for metabolic syndrome based on point-of-care testing analyses. Evaluate pharmacist comprehensive medication management services using point-of-care tests to reduce the mean difference in number of metabolic syndrome risk parameters at 6 and 12 months. Method: This 12-month, prospective, multisite, randomized, controlled study included 120 subjects taking antipsychotics (mean [SD] age of 42.9 [11.3] years) recruited from 3 community mental health clinics in Minnesota. Subjects consented to receive either pharmacist (PCS; n = 60) or no pharmacist (NCS; n = 60) comprehensive medication management services. Data were collected from February 2010 to January 2012. Results: No statistical differences in metabolic syndrome based on point-of-care tests were observed between the 2 groups at baseline (PCS: 85.2%, n = 46 versus NCS: 71.2%, n = 42, P = .073) or at 12 months (PCS: 84.4%, n = 38 versus NCS: 70.2%, n = 33, P = .104). Subjects, overall, screened positive at baseline for dyslipidemia (85.8%, n = 106), hypertension (52.5%, n = 63), and diabetes (22.5%, n = 27) based on point-of-care testing for metabolic risk criteria. After 12 months, a nonsignificant (P = .099) higher adjusted mean number of metabolic syndrome parameters in PCS subjects compared to NCS subjects (mean difference [95% CI] = 0.41 [?0.08 to 0.90]) were found. Conclusions: A relatively high proportion of subjects met criteria for metabolic syndrome, although no significant improvement was observed between the groups after 12 months. Point-of-care test analyses identified a high proportion of subjects meeting criteria for dyslipidemia, hypertension, and diabetes. Utilizing point-of-care tests in mental health settings and fostering interprofessional partnerships with comprehensive medication management pharmacists may improve identification and long-term management of metabolic risks among patients prescribed antipsychotics. Trial Registration: ClinicalTrials.gov identifier: NCT02029989
Shuster, Sara M.; Davey, Cynthia S.
Background. Point-of-care (POC) diagnostics for syphilis can contribute to epidemic control by offering a timely knowledge of serostatus. Although accuracy data on POC syphilis tests have been widely published, few studies have evaluated broader outcomes beyond accuracy that impact patients and health systems. We comprehensively reviewed evidence and reporting of these implementation research outcomes (IROs), and proposed a framework to improve their quality. Methods. Three reviewers systematically searched 6 electronic databases from 1980 to 2014 for syphilis POC studies reporting IROs. Data were abstracted and findings synthesised narratively. Results. Of 71 studies identified, 38 documented IROs. IROs were subclassified into preference (7), acceptability (15), feasibility (15), barriers and challenges (15), impact (13), and prevalence (23). Using our framework and definitions, a pattern of incomplete documentation, inconsistent definitions, and lack of clarity was identified across all IROs. Conclusion. Although POC screening tests for syphilis were generally favourably evaluated across a range of outcomes, the quality of evidence was compromised by inconsistent definitions, poor methodology, and documentation of outcomes. A framework for standardized reporting of outcomes beyond accuracy was proposed and considered a necessary first step towards an effective implementation of these metrics in POC diagnostics research. PMID:24795821
Jafari, Yalda; Joseph, Lawrence; Vadnais, Caroline; Pant Pai, Nitika
This study presents an optical inspection system for detecting a commercial point-of-care testing product and a new detection model covering from qualitative to quantitative analysis. Human chorionic gonadotropin (hCG) strips (cut-off value of the hCG commercial product is 25 mIU/mL) were the detection target in our study. We used a complementary metal-oxide semiconductor (CMOS) sensor to detect the colors of the test line and control line in the specific strips and to reduce the observation errors by the naked eye. To achieve better linearity between the grayscale and the concentration, and to decrease the standard deviation (increase the signal to noise ratio, S/N), the Taguchi method was used to find the optimal parameters for the optical inspection system. The pregnancy test used the principles of the lateral flow immunoassay, and the colors of the test and control line were caused by the gold nanoparticles. Because of the sandwich immunoassay model, the color of the gold nanoparticles in the test line was darkened by increasing the hCG concentration. As the results reveal, the S/N increased from 43.48 dB to 53.38 dB, and the hCG concentration detection increased from 6.25 to 50 mIU/mL with a standard deviation of less than 10%. With the optimal parameters to decrease the detection limit and to increase the linearity determined by the Taguchi method, the optical inspection system can be applied to various commercial rapid tests for the detection of ketamine, troponin I, and fatty acid binding protein (FABP). PMID:25256108
Yeh, Chia-Hsien; Zhao, Zi-Qi; Shen, Pi-Lan; Lin, Yu-Cheng
Early identification of chronic hepatitis B is important for optimal disease management and prevention of transmission. Cost and lack of access to commercial hepatitis B surface antigen (HBsAg) immunoassays can compromise the effectiveness of HBV screening in resource-limited settings and among marginalized populations. High-quality point-of-care (POC) testing may improve HBV diagnosis in these situations. Currently available POC HBsAg assays are often limited in sensitivity. We evaluated the NanoSign® HBs POC chromatographic immunoassay for its ability to detect HBsAg of different genotypes and with substitutions in the ‘a’ determinant. Thirty-seven serum samples from patients with HBV infection, covering HBV genotypes A–G, were assessed for HBsAg titre with the Roche Elecsys HBsAg II quantification assay and with the POC assay. The POC assay reliably detected HBsAg at a concentration of at least 50 IU/mL for all genotypes, and at lower concentrations for some genotypes. Eight samples with substitutions in the HBV ‘a’ determinant were reliably detected after a 1/100 dilution. The POC strips were used to screen serum samples from 297 individuals at risk for HBV in local clinical settings (health fairs and outreach events) in parallel with commercial laboratory HBsAg testing (Quest Diagnostics EIA). POC testing was 73.7% sensitive and 97.8% specific for detection of HBsAg. Although the POC test demonstrated high sensitivity over a range of genotypes, false negatives were frequent in a clinical setting. Nevertheless, the POC assay offers advantages for testing in both developed and resource-limited countries due to its low cost (0.50$) and immediately available results. PMID:24779356
Gish, R G; Gutierrez, J A; Navarro-Cazarez, N; Giang, K; Adler, D; Tran, B; Locarnini, S; Hammond, R; Bowden, S
There is a well-recognized need for low cost biodetection technologies for resource-poor settings with minimal medical infrastructure. Lab-on-a-chip (LOC) technology has the ability to perform biological assays in such settings. The aim of this work is to develop a low cost, high-throughput detection system for the analysis of 96 samples simultaneously outside the laboratory setting. To achieve this aim, several biosensing elements were combined: a syringe operated ELISA lab-on-a-chip (ELISA-LOC) which integrates fluid delivery system into a miniature 96-well plate; a simplified non-enzymatic reporter and detection approach using a gold nanoparticle-antibody conjugate as a secondary antibody and silver enhancement of the visual signal; and Carbon nanotubes (CNT) to increase primary antibody immobilization and improve assay sensitivity. Combined, these elements obviate the need for an ELISA washer, electrical power for operation and a sophisticated detector. We demonstrate the use of the device for detection of Staphylococcal enterotoxin B, a major foodborne toxin using three modes of detection, visual detection, CCD camera and document scanner. With visual detection or using a document scanner to measure the signal, the limit of detection (LOD) was 0.5ng/ml. In addition to visual detection, for precise quantitation of signal using densitometry and a CCD camera, the LOD was 0.1ng/ml for the CCD analysis and 0.5 ng/ml for the document scanner. The observed sensitivity is in the same range as laboratory-based ELISA testing. The point of care device can analyze 96 samples simultaneously, permitting high throughput diagnostics in the field and in resource poor areas without ready access to laboratory facilities or electricity. PMID:21503269
Yang, Minghui; Sun, Steven; Kostov, Yordan
Routine viral-load (VL) testing of HIV-infected individuals on antiretroviral therapy (ART) is used to monitor treatment efficacy. However, due to logistical challenges, implementation of VL has been difficult in resource-limited settings. The aim of this study was to evaluate the performance of the SAMBA semi-Q (simple amplification-based assay semiquantitative test for HIV-1) in London, Malawi, and Uganda. The SAMBA semi-Q can distinguish between patients with VLs above and below 1,000 copies/ml. The SAMBA semi-Q was validated with diluted clinical samples and blinded plasma samples collected from HIV-1-positive individuals. SAMBA semi-Q results were compared with results from the Roche COBAS AmpliPrep/COBAS TaqMan HIV-1 test, v2.0. Testing of 96 2- to 10-fold dilutions of four samples containing HIV-1 subtype C as well as 488 samples from patients in the United Kingdom, Malawi, and Uganda yielded an overall accuracy for the SAMBA semi-Q of 99% (95% confidence interval [CI], 93.8 to 99.9%) and 96.9% (95% CI 94.9 to 98.3%), respectively, compared to to the Roche test. Analysis of VL data from patients in Malawi and Uganda showed that the SAMBA cutoff of 1,000 copies/ml appropriately distinguished treated from untreated individuals. Furthermore, analysis of the viral loads of 232 patients on ART in Malawi and Uganda revealed similar patterns for virological control, defined as either <1,000 copies/ml (SAMBA cutoff) or <5,000 copies/ml (WHO 2010 criterion; WHO, Antiretroviral Therapy for HIV Infection in Adults and Adolescents: Recommendations for a Public Health Approach, 2010). This study suggests that the SAMBA semi-Q has adequate concurrency with the gold standard measurements for viral load. This test can allow VL monitoring of patients on ART at the point of care in resource-limited settings. PMID:25031444
Ritchie, Allyson V.; Ushiro-Lumb, Ines; Edemaga, Daniel; Joshi, Hrishikesh A.; De Ruiter, Annemiek; Szumilin, Elisabeth; Jendrulek, Isabelle; McGuire, Megan; Goel, Neha; Sharma, Pia I.; Allain, Jean-Pierre
Routine viral-load (VL) testing of HIV-infected individuals on antiretroviral therapy (ART) is used to monitor treatment efficacy. However, due to logistical challenges, implementation of VL has been difficult in resource-limited settings. The aim of this study was to evaluate the performance of the SAMBA semi-Q (simple amplification-based assay semiquantitative test for HIV-1) in London, Malawi, and Uganda. The SAMBA semi-Q can distinguish between patients with VLs above and below 1,000 copies/ml. The SAMBA semi-Q was validated with diluted clinical samples and blinded plasma samples collected from HIV-1-positive individuals. SAMBA semi-Q results were compared with results from the Roche COBAS AmpliPrep/COBAS TaqMan HIV-1 test, v2.0. Testing of 96 2- to 10-fold dilutions of four samples containing HIV-1 subtype C as well as 488 samples from patients in the United Kingdom, Malawi, and Uganda yielded an overall accuracy for the SAMBA semi-Q of 99% (95% confidence interval [CI], 93.8 to 99.9%) and 96.9% (95% CI 94.9 to 98.3%), respectively, compared to to the Roche test. Analysis of VL data from patients in Malawi and Uganda showed that the SAMBA cutoff of 1,000 copies/ml appropriately distinguished treated from untreated individuals. Furthermore, analysis of the viral loads of 232 patients on ART in Malawi and Uganda revealed similar patterns for virological control, defined as either <1,000 copies/ml (SAMBA cutoff) or <5,000 copies/ml (WHO 2010 criterion; WHO, Antiretroviral Therapy for HIV Infection in Adults and Adolescents: Recommendations for a Public Health Approach, 2010). This study suggests that the SAMBA semi-Q has adequate concurrency with the gold standard measurements for viral load. This test can allow VL monitoring of patients on ART at the point of care in resource-limited settings. PMID:25031444
Ritchie, Allyson V; Ushiro-Lumb, Ines; Edemaga, Daniel; Joshi, Hrishikesh A; De Ruiter, Annemiek; Szumilin, Elisabeth; Jendrulek, Isabelle; McGuire, Megan; Goel, Neha; Sharma, Pia I; Allain, Jean-Pierre; Lee, Helen H
Background Untreated syphilis in pregnancy is associated with adverse clinical outcomes for the infant. Most syphilis infections occur in sub-Saharan Africa (SSA), where coverage of antenatal screening for syphilis is inadequate. Recently introduced point-of-care syphilis tests have high accuracy and demonstrate potential to increase coverage of antenatal screening. However, country-specific cost-effectiveness data for these tests are limited. The objective of this analysis was to evaluate the cost-effectiveness and budget impact of antenatal syphilis screening for 43 countries in SSA and estimate the impact of universal screening on stillbirths, neonatal deaths, congenital syphilis, and disability-adjusted life years (DALYs) averted. Methods and Findings The decision analytic model reflected the perspective of the national health care system and was based on the sensitivity (86%) and specificity (99%) reported for the immunochromatographic strip (ICS) test. Clinical outcomes of infants born to syphilis-infected mothers on the end points of stillbirth, neonatal death, and congenital syphilis were obtained from published sources. Treatment was assumed to consist of three injections of benzathine penicillin. Country-specific inputs included the antenatal prevalence of syphilis, annual number of live births, proportion of women with at least one antenatal care visit, per capita gross national income, and estimated hourly nurse wages. In all 43 sub-Saharan African countries analyzed, syphilis screening is highly cost-effective, with an average cost/DALY averted of US$11 (range: US$2–US$48). Screening remains highly cost-effective even if the average prevalence falls from the current rate of 3.1% (range: 0.6%–14.0%) to 0.038% (range: 0.002%–0.113%). Universal antenatal screening of pregnant women in clinics may reduce the annual number of stillbirths by up to 64,000, neonatal deaths by up to 25,000, and annual incidence of congenital syphilis by up to 32,000, and avert up to 2.6 million DALYs at an estimated annual direct medical cost of US$20.8 million. Conclusions Use of ICS tests for antenatal syphilis screening is highly cost-effective in SSA. Substantial reduction in DALYs can be achieved at a relatively modest budget impact. In SSA, antenatal programs should expand access to syphilis screening using the ICS test. Please see later in the article for the Editors' Summary PMID:24223524
Kuznik, Andreas; Lamorde, Mohammed; Nyabigambo, Agnes; Manabe, Yukari C.
Glycemic control in hospitalized patients with diabetes requires accurate near-patient glucose monitoring systems. In the past decade, point-of-care blood glucose monitoring devices have become the mainstay of near-patient glucose monitoring in hospitals across the world. In this article, we focus on its history, accuracy, clinical use, and cost-effectiveness. Point-of-care devices have evolved from 1.2 kg instruments with no informatics to handheld lightweight portable devices with advanced connectivity features. Their accuracy however remains a subject of debate, and new standards for their approval have now been issued by both the International Organization for Standardization and the Clinical and Laboratory Standards Institute. While their cost-effectiveness remains to be proved, their clinical value for managing inpatients with diabetes remains unchallenged. This evidence-based review provides an overall view of its use in the hospital setting. PMID:25355711
Rajendran, Rajesh; Rayman, Gerry
Thrombelastography® is a monitor of coagulation and fibrinolytic status, with point-of-care applications in managing haemorrhaging patients. Advocates have suggested a possible role in managing obstetric haemorrhage. This study aims to develop a pregnancy-specific thrombelastography-guided transfusion algorithm, which could be integrated into the management of postpartum haemorrhage. In this prospective observational study, 57 healthy, term-parturients provided pre-caesarean whole blood specimens for thrombelastography analyses. Specimens were processed according to a standardised protocol involving simultaneous analyses using three assays: native (non-activated); kaolin-activated; and kaolin and tissue factor-activated (RapidTEG®). For each assay, the following thrombelastography parameters were measured: reaction time (minutes); clot formation kinetics time (minutes); maximum amplitude (mm); and a angle (degree). Subsequent reference values were used to establish assay-specific reference intervals. For all thrombelastography parameters studied, reference values obtained using a non-activated assay differed from the corresponding values obtained using activated assays, and also demonstrated greater inter-sample variability. From the assay-specific reference intervals obtained, it was possible to establish a pregnancy-specific thrombelastography-guided transfusion algorithm. Specific features of this transfusion algorithm included the preferential use of activated assays, the need for duplicates and a recommendation that an initial baseline thrombelastography measurement is established for subsequent serial comparisons. This transfusion algorithm has been developed to assist with assessment of coagulation and fibrinolytic status during postpartum haemorrhage. PMID:23194210
Hill, J S; Devenie, G; Powell, M
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. PMID:22381707
Litster, A L; Pressler, B; Volpe, A; Dubovi, E
Using a terror management theory framework, this study investigated if providing mortality reminders or self-esteem threats would lead participants to exhibit avoidant responses toward a point-of-care testing device for cardiovascular disease risk and if the nature of the device served to diminish the existential threat of cardiovascular disease. One hundred and twelve participants aged 40-55 years completed an experimental questionnaire. Findings indicated that participants were not existentially threatened by established terror management methodologies, potentially because of cross-cultural variability toward such methodologies. Highly positive appraisals of the device also suggest that similar technologies may beneficially affect the uptake of screening behaviors. PMID:24972015
Dunne, Simon; Gallagher, Pamela; Matthews, Anne
Recent research in the management of haemorrhage has led to several changes in clinical practice. Evidence is accumulating that point-of-care testing results in fewer transfusions, improved patient outcomes, and reduced hospital costs. However, there is still insufficient high quality evidence to support transfusion guidelines and algorithms based on point-of-care tests alone, and more robust studies are needed. The implementation of point-of-care testing requires institutional support and senior clinical leadership to realise the benefits, with educational programmes, audit, and feedback regarding transfusion practice. A change in philosophy is required, from performing testing only when there is an obvious bleeding problem, towards the concept of routinely monitoring high-risk patients throughout the surgical procedure. This informs clinical practice, establishes normal ranges for that population, identifies patients at risk and allows early identification and treatment of evolving coagulopathy. PMID:25440399
Mallett, S V; Armstrong, M
In this paper, a pen-on-paper electrochemiluminescence (PoP-ECL) device was entirely hand drawn and written in commercially available crayon and pencil in turn for the first time, and a constant potential-triggered sandwich-type immunosensor was introduced into the PoP-ECL device to form a low-cost ECL immunodevice proof. Each PoP-ECL device contained a hydrophilic paper channel and two PoP electrodes, and the PoP-ECL device was produced as follows: crayon was firstly used to draw hydrophobic regions on pure cellulose paper to create the hydrophilic paper channels followed with a baking treatment, and then a 6B-type black pencil with low resistivity was applied for precision writing, as the PoP electrodes, across the hydrophilic paper channel. For further point-of-care testing, a portable, low-cost rechargeable battery was employed as the power source to provide constant potential to the PoP electrodes to trigger the ECL. Using Carbohydrate antigen 199 as model analyte, this PoP-ECL immunodevice showed a good linear response range from 0.01-200 U mL(-1) with a detection limit of 0.0055 U mL(-1), a high sensitivity and stability. The proposed PoP-ECL immunodevice could be used in point-of-care testing of other tumor markers for remote regions and developing countries. PMID:24841090
Yang, Hongmei; Kong, Qingkun; Wang, Shaowei; Xu, Jinmeng; Bian, Zhaoquan; Zheng, Xiaoxiao; Ma, Chao; Ge, Shenguang; Yu, Jinghua
Background Point-of-care CD4 tests at HIV diagnosis could improve linkage to care in resource-limited settings. Our objective is to evaluate the clinical and economic impact of point-of-care CD4 tests compared to laboratory-based tests in Mozambique. Methods and Findings We use a validated model of HIV testing, linkage, and treatment (CEPAC-International) to examine two strategies of immunological staging in Mozambique: (1) laboratory-based CD4 testing (LAB-CD4) and (2) point-of-care CD4 testing (POC-CD4). Model outcomes include 5-y survival, life expectancy, lifetime costs, and incremental cost-effectiveness ratios (ICERs). Input parameters include linkage to care (LAB-CD4, 34%; POC-CD4, 61%), probability of correctly detecting antiretroviral therapy (ART) eligibility (sensitivity: LAB-CD4, 100%; POC-CD4, 90%) or ART ineligibility (specificity: LAB-CD4, 100%; POC-CD4, 85%), and test cost (LAB-CD4, US$10; POC-CD4, US$24). In sensitivity analyses, we vary POC-CD4-specific parameters, as well as cohort and setting parameters to reflect a range of scenarios in sub-Saharan Africa. We consider ICERs less than three times the per capita gross domestic product in Mozambique (US$570) to be cost-effective, and ICERs less than one times the per capita gross domestic product in Mozambique to be very cost-effective. Projected 5-y survival in HIV-infected persons with LAB-CD4 is 60.9% (95% CI, 60.9%–61.0%), increasing to 65.0% (95% CI, 64.9%–65.1%) with POC-CD4. Discounted life expectancy and per person lifetime costs with LAB-CD4 are 9.6 y (95% CI, 9.6–9.6 y) and US$2,440 (95% CI, US$2,440–US$2,450) and increase with POC-CD4 to 10.3 y (95% CI, 10.3–10.3 y) and US$2,800 (95% CI, US$2,790–US$2,800); the ICER of POC-CD4 compared to LAB-CD4 is US$500/year of life saved (YLS) (95% CI, US$480–US$520/YLS). POC-CD4 improves clinical outcomes and remains near the very cost-effective threshold in sensitivity analyses, even if point-of-care CD4 tests have lower sensitivity/specificity and higher cost than published values. In other resource-limited settings with fewer opportunities to access care, POC-CD4 has a greater impact on clinical outcomes and remains cost-effective compared to LAB-CD4. Limitations of the analysis include the uncertainty around input parameters, which is examined in sensitivity analyses. The potential added benefits due to decreased transmission are excluded; their inclusion would likely further increase the value of POC-CD4 compared to LAB-CD4. Conclusions POC-CD4 at the time of HIV diagnosis could improve survival and be cost-effective compared to LAB-CD4 in Mozambique, if it improves linkage to care. POC-CD4 could have the greatest impact on mortality in settings where resources for HIV testing and linkage are most limited. Please see later in the article for the Editors' Summary PMID:25225800
Hyle, Emily P.; Jani, Ilesh V.; Lehe, Jonathan; Su, Amanda E.; Wood, Robin; Quevedo, Jorge; Losina, Elena; Bassett, Ingrid V.; Pei, Pamela P.; Paltiel, A. David; Resch, Stephen; Freedberg, Kenneth A.; Peter, Trevor; Walensky, Rochelle P.
Background Acute respiratory infections (ARIs) are by far the most common reason for prescribing an antibiotic in primary care, even though the majority of ARIs are of viral or non-severe bacterial aetiology. Unnecessary antibiotic use will, in many cases, not be beneficial to the patients' recovery and expose them to potential side effects. Furthermore, as a causal link exists between antibiotic use and antibiotic resistance, reducing unnecessary antibiotic use is a key factor in controlling this important problem. Antibiotic resistance puts increasing burdens on healthcare services and renders patients at risk of future ineffective treatments, in turn increasing morbidity and mortality from infectious diseases. One strategy aiming to reduce antibiotic use in primary care is the guidance of antibiotic treatment by use of a point-of-care biomarker. A point-of-care biomarker of infection forms part of the acute phase response to acute tissue injury regardless of the aetiology (infection, trauma and inflammation) and may in the correct clinical context be used as a surrogate marker of infection,possibly assisting the doctor in the clinical management of ARIs.Objectives To assess the benefits and harms of point-of-care biomarker tests of infection to guide antibiotic treatment in patients presenting with symptoms of acute respiratory infections in primary care settings regardless of age.Search methods We searched CENTRAL (2013, Issue 12), MEDLINE (1946 to January 2014), EMBASE (2010 to January 2014), CINAHL (1981 to January 2014), Web of Science (1955 to January 2014) and LILACS (1982 to January 2014).Selection criteria We included randomised controlled trials (RCTs) in primary care patients with ARIs that compared use of point-of-care biomarkers with standard of care. We included trials that randomised individual patients as well as trials that randomised clusters of patients(cluster-RCTs).Two review authors independently extracted data on the following outcomes: i) impact on antibiotic use; ii) duration of and recovery from infection; iii) complications including the number of re-consultations, hospitalisations and mortality; iv) patient satisfaction. We assessed the risk of bias of all included trials and applied GRADE. We used random-effects meta-analyses when feasible. We further analysed results with a high level of heterogeneity in pre-specified subgroups of individually and cluster-RCTs.Main results The only point-of-care biomarker of infection currently available to primary care identified in this review was C-reactive protein. We included six trials (3284 participants; 139 children) that evaluated a C-reactive protein point-of-care test. The available information was from trials with a low to moderate risk of bias that address the main objectives of this review.Overall a reduction in the use of antibiotic treatments was found in the C-reactive protein group (631/1685) versus standard of care(785/1599). However, the high level of heterogeneity and the statistically significant test for subgroup differences between the three RCTs and three cluster-RCTs suggest that the results of the meta-analysis on antibiotic use should be interpreted with caution and the pooled effect estimate (risk ratio (RR) 0.78, 95% confidence interval (CI) 0.66 to 0.92; I2 statistic = 68%) may not be meaningful.The observed heterogeneity disappeared in our pre planned subgroup analysis based on study design: RR 0.90, 95% CI 0.80 to 1.02; I2 statistic = 5% for RCTs and RR 0.68, 95% CI 0.61 to 0.75; I2 statistic = 0% for cluster-RCTs, suggesting that this was the cause of the observed heterogeneity.There was no difference between using a C-reactive protein point-of-care test and standard care in clinical recovery (defined as at least substantial improvement at day 7 and 28 or need for re-consultations day 28). However, we noted an increase in hospitalisations in the C-reactive protein group in one study, but this was based on few events and may be a chance finding. No deaths were reported in any of the included studies.We classified the qualit
Aabenhus, Rune; Jensen, Jens-Ulrik S; Jørgensen, Karsten Juhl; Hróbjartsson, Asbjørn; Bjerrum, Lars
Purpose To identify factors that determine patients’ intentions to use point-of-care medical devices, ie, portable coagulometer devices for self-testing of the international normalized ratio (INR) required for ongoing monitoring of blood-coagulation intensity among patients on long-term oral anticoagulation therapy with vitamin K antagonists, eg, warfarin. Methods A cross-sectional study that applied the technology-acceptance model through a self-completed questionnaire, which was administered to a convenience sample of 125 outpatients attending outpatient anticoagulation services at a district general hospital in London, UK. Data were analyzed using descriptive statistics, factor analyses, and structural equation modeling. Results The participants were mainly male (64%) and aged ? 71 years (60%). All these patients were attending the hospital outpatient anticoagulation clinic for INR testing; only two patients were currently using INR self-testing, 84% of patients had no knowledge about INR self-testing using a portable coagulometer device, and 96% of patients were never offered the option of the INR self-testing. A significant structural equation model explaining 79% of the variance in patients’ intentions to use INR self-testing was observed. The significant predictors that directly affected patients’ intention to use INR self-testing were the perception of technology (? = 0.92, P < 0.001), trust in doctor (? = ?0.24, P = 0.028), and affordability (? = 0.15, P = 0.016). In addition, the perception of technology was significantly affected by trust in doctor (? = 0.43, P = 0.002), age (? = ?0.32, P < 0.001), and affordability (? = 0.23, P = 0.013); thereby, the intention to use INR self-testing was indirectly affected by trust in doctor (? = 0.40), age (? = ?0.29), and affordability (? = 0.21) via the perception of technology. Conclusion Patients’ intentions to use portable coagulometers for INR self-testing are affected by patients’ perceptions about the INR testing device, the cost of device, trust in doctors/clinicians, and the age of the patient, which need to be considered prior to any intervention involving INR self-testing by patients. Manufacturers should focus on increasing the affordability of INR testing devices for patients’ self-testing and on the potential role of medical practitioners in supporting use of these medical devices as patients move from hospital to home testing. PMID:23300344
Shah, Syed Ghulam Sarwar; Barnett, Julie; Kuljis, Jasna; Hone, Kate; Kaczmarski, Richard
Two studies (N = 136) investigated whether or not gender or mortality reminders would impact middle-aged and older adults' appraisal of a novel point-of-care testing device for cardiovascular disease risk. Middle-aged females were significantly more likely to positively appraise and commit to using the device compared to middle-aged males, but there were no such gender differences among older adults. Both studies also failed to support hypotheses that existential concerns would lead to avoidance of the device. When taken together, the findings suggest that similar devices may beneficially affect screening behaviours and underscore a need to target middle-aged males for cardiovascular screening interventions. PMID:24296738
Dunne, Simon; Gallagher, Pamela; Matthews, Anne
BackgroundPathogen-specific metabolic pathways may be detected by breath tests based on introduction of stable isotopically-labeled substrates and detection of labeled products in exhaled breath using portable infrared spectrometers.Methodology\\/Principal FindingsWe tested whether mycobacterial urease activity could be utilized in such a breath test format as the basis of a novel biomarker and diagnostic for pulmonary TB. Sensitized New-Zealand White Rabbits underwent
Mandeep S. Jassal; Gueno G. Nedeltchev; Jong-Hee Lee; Seong Won Choi; Viorel Atudorei; Zachary D. Sharp; Vojo Deretic; Graham S. Timmins; William R. Bishai
...Tests and Kits for the Detection of Colon and Rectal Cancer, Breast Cancer, and Lung Cancer AGENCY: National Institutes of...association and risk-stratification of colon and rectal cancer, breast cancer, and lung cancer. DATES: Only...
Development of small footprint, disposable, fast, and inexpensive devices for pathogen detection in the field and clinic would benefit human and veterinary medicine by allow- ing evidence-based responses to future out breaks. We designed and tested an integrated nucleic acid extraction and amplifica- tion device employing a loop-mediated isothermal amplification (LAMP) or reverse transcriptase-LAMP assay. Our system pro- vides a
Jane P. Bearinger; Lawrence C. Dugan; Brian R. Baker; Sara B. Hall; Katja Ebert; Valerie Mioulet; Mikidache Madi; Donald P. King
Objective To evaluate the performance of a new Chlamydia Rapid Test with vaginal swab specimens as a potential tool for chlamydia diagnosis and screening.Design Performance evaluation study.Settings A young people’s sexual health centre (site 1) and two genitourinary medicine clinics (sites 2 and 3) in the United Kingdom.Participants 1349 women aged between 16 and 54 attending one of the three
Lourdes Mahilum-Tapay; Vivian Laitila; James J Wawrzyniak; Helen H Lee; Sarah Alexander; Catherine Ison; Alison Swain; Penelope Barber; Ines Ushiro-Lumb; Beng T Goh
Development of small footprint, disposable, fast, and inexpensive devices for pathogen detection in the field and clinic would benefit human and veterinary medicine by allowing evidence-based responses to future out breaks. We designed and tested an integrated nucleic acid extraction and amplification device employing a loop-mediated isothermal amplification (LAMP) or reverse transcriptase-LAMP assay. Our system provides a screening tool with polymerase-chain-reaction-level sensitivity and specificity for outbreak detection, response, and recovery. Time to result is ~90 min. The device utilizes a swab that collects sample and then transfers it to a disc of cellulose-based nucleic acid binding paper. The disc is positioned within a disposable containment tube with a manual loading port. In order to test for the presence of target pathogens, LAMP reagents are loaded through the tube’s port into contact with the sample containing cellulose disc. The reagents then are isothermally heated to 63°C for ~1 h to achieve sequence-specific target nucleic acid amplification. Due to the presence of a colorimetric dye, amplification induces visible color change in the reagents from purple to blue. As initial demonstrations, we detected methicillin resistant Staphylococcus aureus genomic DNA, as well as recombinant and live foot-and-mouth disease virus. PMID:21342806
Dugan, Lawrence C.; Baker, Brian R.; Hall, Sara B.; Ebert, Katja; Mioulet, Valerie; Madi, Mikidache; King, Donald P.
Background Blood glucose (BG) meters used for assisted monitoring of blood glucose (AMBG) require different attributes compared with meters designed for home use. These include safety considerations (i.e., minimized risk of blood-borne pathogen transmission), capability for testing multiple blood sample types, and enhanced performance specifications. The OneTouch® Verio™Pro+ BG meter is designed to incorporate all of these attributes. Methods Meter accuracy was assessed in clinical studies with arterial, venous, and capillary blood samples with a hematocrit range of 22.9–59.8%. The effect of interferents, including anticoagulants, on accuracy was evaluated. The meter disinfection protocol was validated, and instructions for use and user acceptance of the system were assessed. Results A total of 97% (549/566) of BG measures from all blood sample types and 95.5% (191/200) of arterial blood samples were within ±12 mg/dl or 12.5% of reference measurements. The system was unaffected by 4 anticoagulants and 57 of 59 endogenous and exogenous compounds; it was affected by 2 compounds: pralidoxime iodide and xylose. Bleach wipes were sufficient to disinfect the meter. Users felt that the meter's quality control (QC) prompts would help them to comply with regulatory requirements. Conclusions The meter provided accurate measurements of different blood samples over a wide hematocrit range and was not affected by 57 physiologic and therapeutic compounds. The QC prompts and specific infection-mitigating design further aid to make this meter system practical for AMBG in care facilities.
MacRury, Sandra; Srinivasan, Aparna; Mahoney, John J.
OBJECTIVE: To assess attitudes and opinions surrounding point-of-care HIV testing among Canadian women, and to determine predictors for acceptance of testing. METHODS: A survey assessing acceptability and attitudes toward rapid HIV testing was distributed on the labour and delivery unit in an academic hospital (St Michael’s Hospital) in Toronto, Ontario, in 2011. Information collected included demographic data, health and pregnancy history, willingness to undergo rapid HIV testing while in labour and barriers to testing. RESULTS: Responses in 92 completed questionnaires were analyzed. The mean age of respondents was 32 years and all were HIV negative. Twelve percent of patients reported having at least one risk factor for HIV transmission. The study showed that only 59% of women were willing to be tested at the time of survey completion, and these women stated that they would accept saliva, urine or serum testing. If found to be positive, 96% would accept antiretroviral treatment and 94% would formula feed their infants. Of the 41% who were not willing to be tested, their reasons for refusal included “don’t want to know” (39%) and being in “too much labour pain” (29%). Regardless of willingness to be tested, the most frequently cited barriers to testing were social stigma (64%) and reaction from partners (69%). CONCLUSIONS: Canadian women in labour were willing to undergo rapid HIV testing via urine, saliva or serum. If found to be positive, women were willing to undergo treatment and to formula feed to prevent mother-to-child transmission of HIV. PMID:25285124
Iqbal, Salikah; De Souza, Leanne R; Yudin, Mark H
BackgroundThe urine lipoarabinomannan (LAM) strip test has been suggested as a new point-of-care test for active tuberculosis (TB) among human immunodeficiency virus (HIV) infected individuals. It has been questioned if infections with nontuberculous mycobacteria (NTM) affect assay specificity. We set forth to investigate if the test detects LAM in urine from a Danish cystic fibrosis (CF) population characterized by a high NTM prevalence and negligible TB exposure.MethodPatients followed at the Copenhagen CF Center were comprehensively screened for pulmonary NTM infection between May 2012 and December 2013. Urine samples were tested for LAM using the 2013 DetermineTM TB LAM Ag strip test.ResultsThree-hundred and six patients had a total of 3,322 respiratory samples cultured for NTM and 198 had urine collected (65%). A total of 23/198 (12%) had active pulmonary NTM infection. None had active TB. The TB-LAM test had an overall positive rate of 2.5% applying a grade 2 cut-point as positivity threshold, increasing to 10.6% (21/198) if a grade 1 cut-point was applied. Among patients with NTM infection 2/23 (8.7%) had a positive LAM test result at the grade 2 cut-point and 9/23 (39.1%) at the grade 1 cut -point. Test specificity for NTM diagnosis was 98.3% and 93.1 for grade 2 and 1 cut-point respectively.ConclusionsThis is the first study to assess urine LAM detection in patients with confirmed NTM infection. The study demonstrated low cross-reactivity due to NTM infection when using the recommended grade 2 cut-point as positivity threshold. This is reassuring in regards to interpretation of the LAM test for TB diagnosis in a TB prevalent setting. The test was not found suitable for NTM detection among patients with CF. PMID:25471640
Qvist, Tavs; Johansen, Isik S; Pressler, Tania; Høiby, Niels; Andersen, Aase B; Katzenstein, Terese L; Bjerrum, Stephanie
Objectives We aimed to explore patient pathways using a chlamydia/gonorrhoea point-of-care (POC) nucleic acid amplification test (NAAT), and estimate and compare the costs of the proposed POC pathways with the current pathways using standard laboratory-based NAAT testing. Design/participants Workshops were conducted with healthcare professionals at four sexual health clinics representing diverse models of care in the UK. They mapped out current pathways that used chlamydia/gonorrhoea tests, and constructed new pathways using a POC NAAT. Healthcare professionals' time was assessed in each pathway. Outcome measure The proposed POC pathways were then priced using a model built in Microsoft Excel, and compared to previously published costs for pathways using standard NAAT-based testing in an off-site laboratory. Results Pathways using a POC NAAT for asymptomatic and symptomatic patients and chlamydia/gonorrhoea-only tests were shorter and less expensive than most of the current pathways. Notably, we estimate that POC testing as part of a sexual health screen for symptomatic patients, or as stand-alone chlamydia/gonorrhoea testing, could reduce costs per patient by as much as £16 or £6, respectively. In both cases, healthcare professionals' time would be reduced by approximately 10?min per patient. Conclusions POC testing for chlamydia/gonorrhoea in a clinical setting may reduce costs and clinician time, and may lead to more appropriate and quicker care for patients. Further study is warranted on how to best implement POC testing in clinics, and on the broader clinical and cost implications of this technology. PMID:25056977
Adams, Elisabeth J; Ehrlich, Alice; Turner, Katherine M E; Shah, Kunj; Macleod, John; Goldenberg, Simon; Meray, Robin K; Pearce, Vikki; Horner, Patrick
Background Point-of-care (POC) tests could be important public health tools in settings with treatment delays and high rates of sexually transmissible infections (STIs). Use is limited due to suboptimal performance. The performance and ease-of-use of a new molecular-based POC test for simultaneous detection of Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) was assessed, alongside two single-organism immunochromatographic tests (ICT). Methods: The evaluation occurred between May 2012 and March 2013 during community STI screens in two remote Aboriginal health services. Urine was tested with the GeneXpert®CT/NG and if sufficient volume, also with Diaquick CT and Gonorrhoea Card. The gold standard comparison was laboratory nucleic acid amplification testing (NAAT). Operational characteristics were also assessed. Results: Among 198 samples, GeneXpert CT sensitivity and specificity was 100% [95% confidence intervals (CI): 75.9-100] and 99.5% (95% CI: 96.5-100), and NG was 100% (95% CI: 96.5-100) and 100% (95% CI: 97.5-100), respectively. Among a sample subset, Diaquick CT (n=104) sensitivity and specificity was 27.3% (95% CI: 7.3-60.7) and 66.7% (95% CI: 12.5-98.2), and Gonorrhoea Card (n=29), was 66.7% (95% CI: 12.5-98.2) and 76.9% (95% CI: 56.0-90.2), respectively. GeneXpert required 1mL of urine, four steps, 1min specimen preparation and 90min to result. ICTs required 15mL of urine, eight steps, 18min preparation and 10-15min to result. Conclusion: The accuracy and operational benefits of GeneXpert CT/NG make it very suitable in these settings where delays to treatment are encountered. PMID:25426655
Causer, Louise M; Hengel, Belinda; Natoli, Lisa; Tangey, Annie; Badman, Steven G; Tabrizi, Sepehr N; Whiley, David; Ward, James; Kaldor, John M; Guy, Rebecca J
Background Bleeding complications in cardiac surgery may lead to increased morbidity and mortality. Traditional blood coagulation tests are not always suitable to detect rapid changes in the patient's coagulation status. Point-of-care instruments such as the TEG (thromboelastograph) and RoTEM (thromboelastometer) have been shown to be useful as a guide for the clinician in the choice of blood products and they may lead to a reduction in the need for blood transfusion, contributing to better patient blood management. Methods The purpose of this study was to evaluate the ability of the TEG, RoTEM and Sonoclot instruments to detect changes in hemostasis in elective cardiac surgery with cardiopulmonary bypass and to investigate possible correlations between variables from these three instruments and routine hematological coagulation tests. Blood samples from thirty-five adult patients were drawn before and after surgery and analyzed in TEG, RoTEM, Sonoclot and routine coagulation tests. Data were compared using repeated measures analysis of variance and Pearson's test for linear correlation. Results We found significant changes for all TEG variables after surgery, for three of the RoTEM variables, and for one variable from the Sonoclot. There were significant correlations postoperatively between plasma fibrinogen levels and variables from the three instruments. Conclusions TEG and RoTEM may be used to detect changes in hemostasis following cardiac surgery with CPB. Sonoclot seems to be less suitable to detect such changes. Variables from the three instruments correlated with plasma fibrinogen and could be used to monitor treatment with fibrinogen concentrate. PMID:25276093
Background Toxicology and Emergency medicine textbooks recommend measurement of acetylcholinesterase (AChE) in all symptomatic cases of organophosphorus (OP) poisoning but laboratory facilities are limited in rural Asia. The accuracy of point-of-care (POC) acetylcholinesterase testing has been demonstrated but it remains to be shown whether results would be valued by clinicians. This study aims to assess the effect of seeing AChE POC test results on the knowledge, attitudes and practices of doctors who frequently manage OP poisoning. Methods We surveyed 23 clinicians, who had different levels of exposure to seeing AChE levels in OP poisoned patients, on a) knowledge of OP poisoning and biomarker interpretation, b) attitudes towards AChE in guiding poison management, oxime therapy and discharge decisions, and c) practices of ordering AChE in poisoning scenarios. Results An overall high proportion of doctors valued the test (68-89%). However, we paradoxically found that doctors who were more experienced in seeing AChE results valued the test less. Lower proportions valued the test in guidance of acute poisoning management (50%, p = 0.015) and guidance of oxime therapy (25%, p = 0.008), and it was apparent it would not generally be used to facilitate early discharge. The highest proportion of respondents valued it on admission (p < 0.001). A lack of correlation of test results with the clinical picture, and a perception that the test was a waste of money when compared to clinical observation alone were also comments raised by some of the respondents. Greater experience with seeing AChE test results was associated with increased knowledge (p = 0.034). However, a disproportionate lack of knowledge on interpretation of biomarkers and the pharmacology of oxime therapy (12-50%) was noted, when compared with knowledge on the mechanism of OP poisoning and management (78-90%). Conclusions Our findings suggest an AChE POC test may not be valued by rural doctors. The practical use of AChE in OP poisoning management is complex, and a poor understanding of how to interpret test results may have affected its perceived utility. Future research should evaluate the impact of providing both AChE and training in interpretation on clinicians’ attitudes and practice. PMID:24589276
Background A rapid diagnostic test for active tuberculosis (TB) at the clinical point-of-care could expedite case detection and accelerate TB treatment initiation. We assessed the diagnostic accuracy of a rapid urine lipoarabinomannan (LAM) test for TB screening among HIV-infected adults in a TB-endemic setting. Methods We prospectively enrolled newly-diagnosed HIV-infected adults (?18 years) at 4 outpatient clinics in Durban from Oct 2011-May 2012, excluding those on TB therapy. A physician evaluated all participants and offered CD4 cell count testing. Trained study nurses collected a sputum sample for acid-fast bacilli smear microscopy (AFB) and mycobacterial culture, and performed urine LAM testing using Determine™ TB LAM in the clinic. The presence of a band regardless of intensity on the urine LAM test was considered positive. We defined as the gold standard for active pulmonary TB a positive sputum culture for Mycobacterium tuberculosis. Diagnostic accuracy of urine LAM was assessed, alone and in combination with smear microscopy, and stratified by CD4 cell count. Results Among 342 newly-diagnosed HIV-infected participants, 190 (56%) were male, mean age was 35.6 years, and median CD4 was 182/mm3. Sixty participants had culture-positive pulmonary TB, resulting in an estimated prevalence of 17.5% (95% CI 13.7-22.0%). Forty-five (13.2%) participants were urine LAM positive. Mean time from urine specimen collection to LAM test result was 40 minutes (95% CI 34–46 minutes). Urine LAM test sensitivity was 28.3% (95% CI 17.5-41.4) overall, and 37.5% (95% CI 21.1-56.3) for those with CD4 count <100/mm3, while specificity was 90.1% (95% CI 86.0-93.3) overall, and 86.9% (95% CI 75.8-94.2) for those with CD4?100/mm3. When combined with sputum AFB (either test positive), sensitivity increased to 38.3% (95% CI 26.0-51.8), but specificity decreased to 85.8% (95% CI 81.1-89.7). Conclusions In this prospective, clinic-based study with trained nurses, a rapid urine LAM test had low sensitivity for TB screening among newly-diagnosed HIV-infected adults, but improved sensitivity when combined with sputum smear microscopy. PMID:24571362
Clopidogrel is a prodrug which is converted into active metabolite by cytochrome P450 isoenzyme, CYP2C19. Numerous polymorphisms of CYP2C19 are reported, and a strong link exists between loss-of-function (LOF) or gain-of-function polymorphisms, clopidogrel metabolism, and clinical outcome. Hence, a fully automated point-of-care CYP2C19 genotyping assay is more likely to bring personalized antiplatelet therapy into real practice. We assessed the feasibility of the Verigene 2C19/CBS Nucleic Acid Test, a fully automated microarray-based assay, compared to bidirectional sequencing, and performed VerifyNow P2Y12 assay to evaluate the effect of CYP2C19 polymorphisms on on-treatment platelet reactivity in 57 Korean patients treated with clopidogrel after percutaneous coronary intervention. The Verigene 2C19/CBS assay identified ?2, ?3, and ?17 polymorphisms with 100% concordance to bidirectional sequencing in 180 minutes with little hands-on time. Patients were classified into 4 groups: extensive (?1/?1; n = 12, 21.1%), intermediate (?1/?2, ?1/?3; n = 33, 57.9%), poor (?2/?2, ?2/?3, and ?3/?3; n = 11, 19.3%), and ultrarapid metabolizers (?1/?17; n = 1, 1.8%). The prevalence of the CYP2C19???2, ?3, and ?17 alleles was 36.0%, 12.3%, and 0.9%. Platelet reactivity showed gene dose response according to the number of CYP2C19 LOF allele. In conclusion, the Verigene 2C19/CBS assay gave accurate CYP2C19 genotype results which were in well match with the differing on-treatment platelet reactivity. PMID:23607088
Chae, Hyojin; Kim, Myungshin; Koh, Yoon-Seok; Hwang, Byung-Hee; Kang, Min-Kyu; Kim, Yonggoo; Park, Hae-il; Chang, Kiyuk
We compared results obtained with the Nanosphere Verigene® System, a novel point-of-care (POC) genetic test capable of analysing 11 CYP2C19 variants within 3 hours, to an established, validated genotyping method (Affymetrix™ DMET+; reference assay) for identifying extensive and reduced metabolisers of clopidogrel. Based on genotyping, patients (N=82) with stable coronary artery disease on clopidogrel 75 mg daily were defined as extensive metabolisers (*1/*1, *1/*17, *17/*17), reduced metabolisers (*1/*2, *1/*8, *2/*2, *2/*3), or of indeterminate metaboliser status (*2/*17). Pharmacokinetic exposure to clopidogrel's active metabolite and pharmacodynamic measures with P2Y12 reaction units (PRU) (VerifyNow®P2Y12 assay) and VASP PRI (PRI) were also assessed. There was a 99.9% overall concordance of marker-level data between the Nanosphere Verigene and DMET+ systems in identifying the CYP2C19 variants and 100% agreement in classifying the patients as extensive (n=59) or reduced metabolisers (n=15). Extensive metabolisers had significantly higher active metabolite exposure than reduced metabolisers (LS means 12.6 ng*h/ml vs 7.7 ng*h/ml; p<0.001). Extensive metabolisers also had lower PRU (LS means 158 vs 212; p=0.003) and VASP PRI (LS means 48% vs 63%, p=0.01) compared to reduced metabolisers. Rates of high on-treatment platelet reactivity were higher in reduced metabolisers compared to extensive metabolisers (VASP PRI ? 50%: 79% vs 47%; PRU >235: 33% vs 16%). The Nanosphere Verigene CBS system identified 11 CYP2C19 alleles in less than 3 hours with a high degree of accuracy when compared to a conventional method, and was further validated against pharmacokinetic and pharmacodynamic phenotypes. PMID:24402637
Erlinge, David; James, Stefan; Duvvuru, Suman; Jakubowski, Joseph A; Wagner, Henrik; Varenhorst, Christoph; Tantry, Udaya S; Brown, Patricia B; Small, David; Moser, Brian A; Sundseth, Scott S; Walker, Joseph R; Winters, Kenneth J; Gurbel, Paul A
Objective Previous studies have reported a considerable association between the VerifyNow (Accumetrics, San Diego, CA, USA) P2Y12 assay results and hematocrit. No reports, however, have described an association between the multiple electrode platelet aggregometry (MEA; Dynabyte, Munich, Germany) adenosine diphosphate (ADP) assay results and hematocrit. This study was conducted to evaluate the influence of hematocrit on the results of 2 different point-of-care platelet function tests. Methods A total of 462 consecutive patients who were undergoing percutaneous coronary intervention were enrolled. Platelet function was evaluated with both the VerifyNow P2Y12 and MEA ADP assays. Results Anemic patients (n?=?152, 32.9%) demonstrated a significantly higher rate of cardiac death, myocardial infarction, and stroke (5.3% vs. 2.3%, p?=?0.046) during the follow-up (median: 18.8 months). Although the VerifyNow P2Y12 assay results demonstrated a significant inverse correlation with hematocrit (r?=??0.409, p<0.001), there was no such correlation between the MEA ADP assay results and hematocrit (r?=?0.039, p?=?0.401). In the multivariate analysis, anemia was an independent predictor of high on-treatment platelet reactivity, defined as a VerifyNow P2Y12 reaction unit level of ?252.5 (odds ratio?=?2.21, 95% confidence interval?=?1.39–3.52; p?=?0.001). Importantly, this association was independent of an intrinsic change in platelet reactivity as measured by the MEA ADP assay. Adjusting for the influence of hematocrit improved the strength of the correlation between the VerifyNow P2Y12 and MEA ADP assay results. Conclusions Hematocrit significantly influenced the VerifyNow P2Y12 assay results, a phenomenon that was presumably in-vitro. Hematocrit level should therefore be considered when interpreting results of the VerifyNow P2Y12 assay. PMID:25427105
Kim, Yun Gi; Suh, Jung-Won; Park, Jin Joo; Oh, Il-Young; Yoon, Chang-Hwan; Cho, Young-Seok; Youn, Tae-Jin; Chae, In-Ho; Choi, Dong-Ju
A novel in-clinic point-of-care (ICPOC) polymerase chain reaction (PCR) test was evaluated for its ability to detect Ehrlichia canis DNA in artificially infected dogs compared to a real-time PCR assay. Six Beagle dogs negative for E. canis antibodies and PCR negative were artificially infected with an Israeli E. canis strain (611). All dogs developed IgG antibodies 8 days post infection (PI), and clinical and hematological abnormalities on day 10 PI. Only the real-time PCR detected E. canis DNA in the blood of five dogs at days 3 and 5 PI. At day 12 PI during the acute phase of the disease, 1 day after the initiation of doxycycline treatment, the ICPOC PCR assay detected E. canis DNA in all infected dogs, which were also positive by the real-time PCR. Two days later the ICPOC PCR assay was able to detect only 3/6 infected dogs, which were all positive by the real-time PCR. At days 17 and 19 PI, the ICPOC PCR assay did not detect E. canis DNA in the dogs while the real-time PCR detected all dogs as positive on day 17 PI and two dogs on day 19 PI. In conclusion, the sensitivity of the ICPOC PCR assay was 75% for the acute phase of the disease and 30% for the whole study, suggesting that this ICPOC assay has a potential utility for the diagnosis of acute canine monocytic ehrlichiosis. PMID:25453243
Waner, Trevor; Nachum-Biala, Yaarit; Harrus, Shimon
Noninferiority of glucose-6-phosphate dehydrogenase deficiency diagnosis by a point-of-care rapid test vs the laboratory fluorescent spot test demonstrated by copper inhibition in normal human red blood cells.
Tens of millions of patients diagnosed with vivax malaria cannot safely receive primaquine therapy against repeated attacks caused by activation of dormant liver stages called hypnozoites. Most of these patients lack access to screening for glucose-6-phosphate dehydrogenase (G6PD) deficiency, a highly prevalent disorder causing serious acute hemolytic anemia with primaquine therapy. We optimized CuCl inhibition of G6PD in normal red blood cells (RBCs) to assess G6PD diagnostic technologies suited to point of care in the impoverished rural tropics. The most widely applied technology for G6PD screening-the fluorescent spot test (FST)-is impractical in that setting. We evaluated a new point-of-care G6PD screening kit (CareStart G6PD, CSG) against FST using graded CuCl treatments to simulate variable hemizygous states, and varying proportions of CuCl-treated RBC suspensions to simulate variable heterozygous states of G6PD deficiency. In experiments double-blinded to CuCl treatment, technicians reading FST and CSG test (n = 269) classified results as positive or negative for deficiency. At G6PD activity ?40% of normal (n = 112), CSG test was not inferior to FST in detecting G6PD deficiency (P = 0.003), with 96% vs 90% (P = 0.19) sensitivity and 75% and 87% (P = 0.01) specificity, respectively. The CSG test costs less, requires no specialized equipment, laboratory skills, or cold chain for successful application, and performs as well as the FST standard of care for G6PD screening. Such a device may vastly expand access to primaquine therapy and aid in mitigating the very substantial burden of morbidity and mortality imposed by the hypnozoite reservoir of vivax malaria. PMID:25312015
Baird, J Kevin; Dewi, Mewahyu; Subekti, Decy; Elyazar, Iqbal; Satyagraha, Ari W
Due to great use of touchscreens in mobile telephones and other electronic devices, there has been great evolution in this technology. Its wide applicability makes the touch sensor technology suitable for detection of specific components in urine, responsible for urinary tract infection (UTI). Integration of a touch sensor in a disposable probe tip to be used in UTI detection represents a powerful tool to develop new point-of-care testing (POCT) devices. The simplified structure of an electrodes array touch screen was simulated using the software COMSOL Multiphysics to prove that capacitive based touch screens can be used for detection of UTI. Besides we assumed presence of E.coli, one of the major causes of UTI urine. Results show that global capacitance increases if an E.coli sphere is present near the active electrodes, remaining approximately constant when further apart electrodes are excited. The output simulated voltage varies according to the capacitance value, decreasing when the capacitance is increased. PMID:25571114
Barbosa, Catia; Tao Dong
BackgroundSerologic assays that identify herpes simplex type 2 (HSV-2) type-specific antibodies have been commercially available for more than a decade. Greater acceptance of these tests is hindered by uncertainty regarding their performance in real-world clinical settings.
Bridget Leyland; Margaret R. Kennedy; Yolanda H. Wimberly; Bruce J. Levine; Thomas L. Cherpes
Currently, there is no routine monitoring of an immune response to the anthrax vaccine. Simple on-site tests are needed to evaluate the antibody response of anthrax-vaccinated individuals in the Armed Forces and others at high risk. Using a prototype lateral flow assay (LFA) (R. E. Biagini, D. L. Sammons, J. P. Smith, B. A. MacKenzie, C. A. F. Striley, J.
Diane R. Bienek; Raymond E. Biagini; David G. Charlton; Jerome P. Smith; Deborah L. Sammons; Shirley A. Robertson
Excessive bleeding after cardiopulmonary bypass (CPB) operations remains to be a persistent problem and weak platelet function certainly contributes to bleeding diathesis. Antiplatelet therapy (APT) is an integral component of perioperative management in patients undergoing cardiac surgery procedures, both with and without use of CPB. In addition to individual variability in platelet function, different preoperative APT administration/discontinuation management further affects platelet function, which in turn may reflect bleeding tendency. However, the impact of drug-induced platelet inhibition on early postoperative bleeding extent remains difficult to predict. Herein, we reviewed the available evidence on the association between platelet function testing values and the extent of bleeding and transfusion requirements in early perioperative period. Currently, the association between platelet function measured by ex vivo assay and the occurrence of bleeding events remains uncertain. The intent of this review is to provide comprehensive literature insight into published evidence, investigating the possibility of platelet function tests to predict bleeding extent as well as transfusion requirements in cardiac surgery patients. PMID:24983736
Petricevic, Mate; Kopjar, Tomislav; Biocina, Bojan; Milicic, Davor; Kolic, Kresimir; Boban, Marko; Skoric, Bosko; Lekic, Ante; Gasparovic, Hrvoje
Many of the target molecules that reside in blood are also present in oral fluids, albeit at lower concentrations. Oral fluids are, however, relatively easy and safe to collect without the need for specialized equipment and training. Thus, oral fluids provide convenient samples for medical diagnostics. Recent advances in lab-on-a-chip technologies have made minute, fully integrated diagnostic systems practical for an assortment of point-of-care tests. Such systems can perform either immunoassays or molecular diagnostics outside centralized laboratories within time periods ranging from minutes to an hour. The article briefly reviews recent advances in devices for point-of-care testing with a focus on work that has been carried out by the authors as part of a NIH program. PMID:21521419
Hart, RW; Mauk, MG; Liu, C; Qiu, X; Thompson, JA; Chen, D; Malamud, D; Abrams, WR; Bau, HH
Rapid and accurate diagnosis of a patient with an acute disease is a challenge for emergency physicians. Natriuretic peptides have emerged as important tools for diagnosis, risk stratification and therapeutic decision making for some categories of emergency patients. Brain natriuretic peptide (BNP) is a member of a four natriuretic peptides family that shares a common 17-peptide ring structure. Atrial natriuretic peptide, C-natriuretic peptide (CNP), and D-type natriuretic peptide are the other natriuretic peptide, which share the same common 17-peptide ring structure. The N-terminal fragment of pro-BNP, N-terminal pro-brain natriuretic peptide (NT-proBNP) consists of 76 amino acids, which is biologically inert, while the active component BNP contains 32 amino acids. BNP and NT-proBNP are secreted in the plasma in equimolar quantities and are frequently used in the diagnosis of congestive heart failure, and distinguishing between patients with dyspnea of cardiac or pulmonary origin. Both natriuretic peptides have also been evaluated for use in the assessment and management of several other conditions including sepsis, cirrhosis of liver and renal failure. However, one should remember that the values of natriuretic peptides are affected by age and weight of the patients, and presence of several comorbidities such as chronic renal failure, type 2 diabetes mellitus, anemia, pulmonary embolism, and acute coronary syndrome. Values of these peptides also vary depending on the type of test used. The performance characteristics of these natriuretic peptides vary depending on the patients on whom they are used. Therefore determination of reference values for these peptides represents a challenge. PMID:25337482
Nayer, Jamshed; Aggarwal, Praveen; Galwankar, Sagar
The burden of health-care related services in a global era with continuously increasing population and inefficient dissipation of the resources requires effective solutions. From this perspective, point-of-care diagnostics is a demanded field in clinics. It is also necessary both for prompt diagnosis and for providing health services evenly throughout the population, including the rural districts. The requirements can only be fulfilled by technologies whose productivity has already been proven, such as complementary metal-oxide-semiconductors (CMOS). CMOS-based products can enable clinical tests in a fast, simple, safe, and reliable manner, with improved sensitivities. Portability due to diminished sensor dimensions and compactness of the test set-ups, along with low sample and power consumption, is another vital feature. CMOS-based sensors for cell studies have the potential to become essential counterparts of point-of-care diagnostics technologies. Hence, this review attempts to inform on the sensors fabricated with CMOS technology for point-of-care diagnostic studies, with a focus on CMOS image sensors and capacitance sensors for cell studies. PMID:23112587
Adiguzel, Yekbun; Kulah, Haluk
As part of the development of a point of care complete blood count device, I designed a single use lancet integrated with a blood collection mechanism and interface and successfully tested a prototype. High speed video was ...
Zimmerman, Julia C
Effective prevention of HIV/AIDS requires early diagnosis, initiation of therapy, and regular plasma viral load monitoring of the infected individual. In addition, incidence estimation using accurate and sensitive assays is needed to facilitate HIV prevention efforts in the public health setting. Therefore, more affordable and accessible point-of-care (POC) technologies capable of providing early diagnosis, HIV viral load measurements, and CD4 counts in settings where HIV is most prevalent are needed to enable appropriate intervention strategies and ultimately stop transmission of the virus within these populations to achieve the future goal of an AIDS-free generation. This review discusses the available and emerging POC technologies for future application to these unmet public health needs. PMID:24579041
Hewlett, Indira K.
Recent developments in nanotechnology have led to significant advancements in point-of-care (POC) nucleic acid detection. The ability to sense DNA and RNA in a portable format leads to important applications for a range of settings, from on-site detection in the field to bedside diagnostics, in both developing and developed countries. We review recent innovations in three key process components for nucleic acid detection: sample preparation, target amplification, and read-out modalities. We discuss how the advancements realized by nanotechnology are making POC nucleic acid detection increasingly applicable for decentralized and accessible testing, in particular for the developing world.
Hartman, Mark R.; Ruiz, Roanna C. H.; Hamada, Shogo; Xu, Chuanying; Yancey, Kenneth G.; Yu, Yan; Han, Wei; Luo, Dan
Improving the access to effective and affordable healthcare has long been a global endeavor. In this quest, the development of cost-effective and easy-to-use medical testing equipment that enable rapid and accurate diagnosis is essential to reduce the time and costs associated with healthcare services. To this end, point-of-care (POC) diagnostics plays a crucial role in healthcare delivery in both the developed and developing countries by bringing medical testing to patients, or to sites near patients. As the diagnosis of a wide range of diseases, including various types of cancers and many endemics relies on optical techniques, numerous compact and cost-effective optical imaging platforms have been developed in recent years for use at the POC. Here, we review the state-of-the-art optical imaging techniques that can have significant impact on global health by facilitating effective and affordable POC diagnostics. PMID:23044793
Zhu, Hongying; Isikman, Serhan O.; Mudanyali, Onur; Greenbaum, Alon; Ozcan, Aydogan
BackgroundAccurate, inexpensive point-of-care CD4+ T cell testing technologies are needed that can deliver CD4+ T cell results at lower level health centers or community outreach voluntary counseling and testing. We sought to evaluate a point-of-care CD4+ T cell counter, the Pima CD4 Test System, a portable, battery-operated bench-top instrument that is designed to use finger stick blood samples suitable for
Yukari C. Manabe; Yaping Wang; Ali Elbireer; Brandon Auerbach; Barbara Castelnuovo
Rapid volatile profiling of stool sample headspace was achieved using a combination of short multi-capillary chromatography column (SMCC), highly sensitive heated metal oxide semiconductor sensor and artificial neural network software. For direct analysis of biological samples this prototype offers alternatives to conventional gas chromatography (GC) detectors and electronic nose technology. The performance was compared to an identical instrument incorporating a long single capillary column (LSCC). The ability of the prototypes to separate complex mixtures was assessed using gas standards and homogenized in house ‘standard’ stool samples, with both capable of detecting more than 24 peaks per sample. The elution time was considerably faster with the SMCC resulting in a run time of 10 min compared to 30 min for the LSCC. The diagnostic potential of the prototypes was assessed using 50 C. difficile positive and 50 negative samples. The prototypes demonstrated similar capability of discriminating between positive and negative samples with sensitivity and specificity of 85% and 80% respectively. C. difficile is an important cause of hospital acquired diarrhoea, with significant morbidity and mortality around the world. A device capable of rapidly diagnosing the disease at the point of care would reduce cases, deaths and financial burden.
McGuire, N. D.; Ewen, R. J.; de Lacy Costello, B.; Garner, C. E.; Probert, C. S. J.; Vaughan, K.; Ratcliffe, N. M.
Invited Paper This paper presents the development of a disposable plastic biochip incorporating smart- plications in clinical diagnostics and point-of-care testing. The fully integrated disposable biochip components. The biochip has a unique power source using on-chip pressurized air reservoirs, for microfluidic
Orally based diagnostic testing is emerging as an alternative, noninvasive method for analyzing a variety of analytes. These analytes include pathogens, antibodies, drugs, and nucleic acids. In the present study we developed a protocol for evaluation of collectors that could be used in orally based, point-of-care diagnostics. A performance comparison was carried out with a number of commercially available collectors,
Carol Holm-Hansen; Gary Tong; Cheryl Davis; William R. Abrams; Daniel Malamud
The rapid detection and identification of infectious disease pathogens is a critical need for healthcare in both developed and developing countries. As we gain more insight into the genomic basis of pathogen infectivity and drug resistance, point-of-care nucleic acid testing will likely become an important tool for global health. In this paper, we present an inexpensive, handheld, battery-powered instrument designed to enable pathogen genotyping in the developing world. Our Microfluidic Biomolecular Amplification Reader (µBAR) represents the convergence of molecular biology, microfluidics, optics, and electronics technology. The µBAR is capable of carrying out isothermal nucleic acid amplification assays with real-time fluorescence readout at a fraction of the cost of conventional benchtop thermocyclers. Additionally, the µBAR features cell phone data connectivity and GPS sample geotagging which can enable epidemiological surveying and remote healthcare delivery. The µBAR controls assay temperature through an integrated resistive heater and monitors real-time fluorescence signals from 60 individual reaction chambers using LEDs and phototransistors. Assays are carried out on PDMS disposable microfluidic cartridges which require no external power for sample loading. We characterize the fluorescence detection limits, heater uniformity, and battery life of the instrument. As a proof-of-principle, we demonstrate the detection of the HIV-1 integrase gene with the µBAR using the Loop-Mediated Isothermal Amplification (LAMP) assay. Although we focus on the detection of purified DNA here, LAMP has previously been demonstrated with a range of clinical samples, and our eventual goal is to develop a microfluidic device which includes on-chip sample preparation from raw samples. The µBAR is based entirely around open source hardware and software, and in the accompanying online supplement we present a full set of schematics, bill of materials, PCB layouts, CAD drawings, and source code for the µBAR instrument with the goal of spurring further innovation toward low-cost genetic diagnostics. PMID:23936402
Myers, Frank B; Henrikson, Richard H; Bone, Jennifer M; Bone, Jennifer; Lee, Luke P
A variety of point-of-care monitors for the measurement of hematocrit, hemoglobin, blood gas with electrolytes, and lactate can be used also in the prehospital setting for optimizing and individualizing trauma resuscitation. Point-of-care coagulation testing with activated prothrombin test, prothrombin test, and activated coagulation/clotting time tests is available for prehospital use. Although robust, battery driven, and easy to handle, many devices lack documentation for use in prehospital care. Some of the devices correspond poorly to corresponding laboratory analyses in acute trauma coagulopathy and at lower hematocrits. In trauma, viscoelastic tests such as rotational thromboelastometry and thromboelastography can rapidly detect acute trauma coagulopathy and give an overall dynamic picture of the hemostatic system and the interaction between its different components: coagulation activation, fibrin polymerization, fibrin platelet interactions within the clot, and fibrinolysis. Rotational thromboelastometry is shock resistant and has the potential to be used outside the hospital setting to guide individualized coagulation factor and blood component therapies. Sonoclot and Rheorox are two small viscoelastic instruments with one-channel options, but with less documentation. The point-of-care market for coagulation tests is quickly expanding, and new devices are introduced all the time. Still they should be better adopted to prehospital conditions, small, robust, battery charged, and rapid and use small sample volumes and whole blood. PMID:24365883
Practitioners other than radiologists and certified sonographers are increasingly using ultrasound at the bedside to facilitate immediate patient management from both procedural and diagnostic standpoints. This editorial provides a brief overview of the use of point-of-care ultrasound in clinical practice, its potential to improve patient care, and some of the unanswered questions surrounding issues of training, scope of practice, and quality assurance. PMID:25064491
Morris, Amy E
An architecture built from five software components -a Router, Parser, Matcher, Mapper, and Server -fulfills key requirements common to several point-of-care information and knowledge processing tasks. The requirements include problem-list creation, exploiting the contents of the Electronic Medical Record for the patient at hand, knowledge access, and support for semantic visualization and software agents. The components use the National Library of Medicine Unified Medical Language System to create and exploit lexical closure-a state in which terms, text and reference models are represented explicitly and consistently. Preliminary versions of the components are in use in an oncology knowledge server. PMID:8947646
Tuttle, M S; Sherertz, D D; Olson, N E; Nelson, S J; Erlbaum, M S; Keck, K D; Davis, A N; Suarez-Munist, O N; Lipow, S S; Cole, W G; Fagan, L M; Acuff, R D; Crangle, C E; Musen, M A; Tu, S W; Wiederhold, G C; Carlson, R W
Advances in optical designs are enabling the development of miniature microscopes that can examine tissue in situ for early anatomic and molecular indicators of disease, in real time, and at cellular resolution. These new devices will lead to major changes in how diseases are detected and managed, driving a shift from today’s diagnostic paradigm of biopsy followed by histopathology and recommended therapy, to non-invasive point-of-care diagnosis with possible same-session definitive treatment. This shift may have major implications for the training requirements of future physicians to enable them to interpret real-time in vivo microscopic data, and will also shape the emerging fields of telepathology and telemedicine. Implementation of new technologies into clinical practice is a complex process that requires bridging gaps between clinicians, engineers and scientists. This article provides a forward-looking discussion of these issues, with a focus on malignant and pre-malignant lesions, by first highlighting some of the clinical areas where point-of-care in vivo microscopy could address unmet needs, and then by reviewing the technological challenges that are being addressed, or need to be addressed, for in vivo microscopy to become a standard clinical tool. PMID:21673433
Liu, Jonathan T.C.; Loewke, Nathan O.; Mandella, Michael J.; Levenson, Richard M.; Crawford, James M.; Contag, Christopher H.
Lab-on-a-chip technologies have pervaded various fields of the life sciences including nucleic acid testing, immunoassays and cell screening. It has by now been clearly recognized that microfluidic liquid handling offers a unique approach to integrate, automate, parallelize and miniaturize assay formats, thus making it possible to port them from the lab bench to point of care settings. In systems biology,
This work reviews present technologies and developing trends in Point-of-Care (POC) microfluidic diagnostics platforms. First, various fluidics technologies such as pressure-driven flows, capillary flows, electromagnetically driven flows, centrifugal fluidics, acoustically driven flows, and droplet fluidics are categorized. Then three broad categories of POC microfluidic testing devices are considered: lateral flow devices, desktop and handheld POC diagnostic platforms, and emergent molecular diagnostic POC systems. Such evolving trends as miniaturization, multiplexing, networking, new more sensitive detection schemes, and the importance of sample processing are discussed. It is concluded that POC microfluidic diagnostics has a potential to improve patient treatment outcome and bring substantial savings in overall healthcare costs. PMID:23329432
Kulinsky, Lawrence; Noroozi, Zahra; Madou, Marc
The development of new point of care coagulation assay devices is necessary due to the increasing number of patients requiring long-term anticoagulation in addition to the desire for appropriate, targeted anticoagulant therapy and a more rapid response to optimization of treatment. The majority of point of care devices currently available for hemostasis testing rely on clot-based endpoints which are variable, unreliable and limited to measuring only certain portions of the coagulation pathway. Here we present a novel fluorescence-based anti-Factor Xa (FXa) microfluidic assay device for monitoring the effect of anticoagulant therapy at the point of care. The device is a disposable, laminated polymer microfluidic strip fabricated from a combination of hydrophobic and hydrophilic cyclic polyolefins to allow reagent deposition in addition to effective capillary fill. Zeonor was the polymer of choice resulting in low background fluorescence (208.5 AU), suitable contact angles (17.5°± 0.9°) and capillary fill times (20.3 ± 2.1 s). The device was capable of measuring unfractionated heparin and tinzaparin from 0-0.8 U ml(-1) and enoxaparin from 0-0.6 U ml(-1) with average CVs < 10%. A linear correlation was observed between the device and the fluorescent assay in the plate for plasma samples spiked with UFH, with an R(2) value of 0.99, while correlations with tinzaparin and enoxaparin resulted in sigmoidal responses (R(2) = 0.99). Plasma samples containing UFH resulted in a linear correlation between the device and a standard chromogenic assay with an R(2) value of 0.98, with both LMWHs resulting in sigmoidal relationships (R(2) = 0.99). PMID:23666610
Harris, Leanne F; Rainey, Paul; Castro-López, Vanessa; O'Donnell, James S; Killard, Anthony J
Dielectrophoresis (DEP) is a label free, noninvasive, stand alone, rapid, and sensitive particle manipulation and characterization technique. Improvements in micro-electro-mechanical systems technology have enabled the biomedical applications of DEP over the past decades. By this way, integration of DEP into lab-on-a-chip systems has become achievable, creating a potential tool for point-of-care (POC) systems. DEP can be utilized in many different POC applications including early detection and prognosis of various cancer types, diagnosis of infectious diseases, blood cell analysis, and stem cell therapy. However, there are still some challenges to be resolved to have DEP-based devices available in POC market. Today, researchers have focused on these challenges to have this powerful theory as a solution for many POC applications. Here, DEP theory, cell modeling, and most common device structures are introduced briefly. Next, POC applications of DEP theory, such as cell (blood, cancer, stem, and fetal) and microorganism separation, manipulation, and enrichment for diagnosis and prognosis, are explained. Integration of DEP with other detection techniques to have more sensitive systems is summarized. Finally, future outlook for DEP-based systems are discussed with some challenges, which are currently preventing these systems to be a common tool for POC applications, and possible solutions. PMID:23348714
Demircan, Ya?mur; Özgür, Ebru; Külah, Haluk
Control of blood glucose (BG) in an acceptable range is a major therapy target for diabetes patients in both the hospital and outpatient environments. This review focuses on the state of point-of-care (POC) glucose monitoring and the accuracy of the measurement devices. The accuracy of the POC glucose monitor depends on device methodology and other factors, including sample source and collection and patient characteristics. Patient parameters capable of influencing measurements include variations in pH, blood oxygen, hematocrit, changes in microcirculation, and vasopressor therapy. These elements alone or when combined can significantly impact BG measurement accuracy with POC glucose monitoring devices (POCGMDs). In general, currently available POCGMDs exhibit the greatest accuracy within the range of physiological glucose levels but become less reliable at the lower and higher ranges of BG levels. This issue raises serious safety concerns and the importance of understanding the limitations of POCGMDs. This review will discuss potential interferences and shortcomings of the current POCGMDs and stress when these may impact the reliability of POCGMDs for clinical decision-making. PMID:22538154
Rebel, Annette; Rice, Mark A.; Fahy, Brenda G.
Dipstick and lateral-flow formats have dominated rapid diagnostics over the last three decades. These formats gained popularity in the consumer markets due to their compactness, portability and facile interpretation without external instrumentation. However, lack of quantitation in measurements has challenged the demand of existing assay formats in consumer markets. Recently, paper-based microfluidics has emerged as a multiplexable point-of-care platform which might transcend the capabilities of existing assays in resource-limited settings. However, paper-based microfluidics can enable fluid handling and quantitative analysis for potential applications in healthcare, veterinary medicine, environmental monitoring and food safety. Currently, in its early development stages, paper-based microfluidics is considered a low-cost, lightweight, and disposable technology. The aim of this review is to discuss: (1) fabrication of paper-based microfluidic devices, (2) functionalisation of microfluidic components to increase the capabilities and the performance, (3) introduction of existing detection techniques to the paper platform and (4) exploration of extracting quantitative readouts via handheld devices and camera phones. Additionally, this review includes challenges to scaling up, commercialisation and regulatory issues. The factors which limit paper-based microfluidic devices to become real world products and future directions are also identified. PMID:23652632
Yetisen, Ali Kemal; Akram, Muhammad Safwan; Lowe, Christopher R
Point-of-care ultrasonography with a pocket ultrasound device, General Electric Medical Systems Vscan (Milwaukee, Wisconsin), has been shown to be effective and easy to learn. However, no studies to date have evaluated its use in the military primary care setting where its portability and value in bedside diagnosis would be especially beneficial. We tested the feasibility of the Vscan in the day-to-day care of patients by family physicians in their clinic, inpatient wards, and its potential for use in the military-deployed setting. Participants were trained and credentialed in the use of the point-of-care ultrasonography. Then, participants were provided with a pocket ultrasound device to use in their normal day-to-day practice. Additionally, participants completed surveys and provided ratings on their perceptions regarding the use of the device. According to the survey analysis, participants found the devices to be easy to use, valuable in discerning a diagnosis, and were not prohibitively time consuming. Moreover, patients were perceived by the participants to have been satisfied with the use of the device. Overall, participants had high satisfaction with the Vscan and perceived that the device would be highly valuable in the military-deployed setting. PMID:25469971
Bornemann, Paul; Bornemann, Gina
An automated point-of-care (POC) immunodetection system for immunological detection of Staphylococcal enterotoxin B (SEB) was designed, fabricated, and tested. The system combines several elements: (1) ELISA-Lab-on-a-chip (ELISA-LOC) with fluidics, (2) a CCD camera detector, (3) pumps and valves for fluid delivery to the ELISA-LOC, (4) a computer interface board, and (5) a computer for controlling the fluidics, logging and data analysis of the CCD data. The ELISA-LOC integrates a simple microfluidics system into a miniature ninety-six well sample plate, allowing the user to carry out immunological assays without a laboratory. The analyte is measured in a sandwich ELISA assay format combined with a sensitive Electrochemiluminescence (ECL) detection method. Using the POC system, SEB, a major foodborne toxin, was detected at concentrations as low as 0.1 ng/ml. This is similar to the reported sensitivity of conventional ELISA. The open platform with simple modular fluid delivery automation design described here is interchangeable between detection systems and because of its versatility it can be also used to automate many other LOC systems, simplifying LOC development. This new point-of-care system is useful for carrying out various immunological and other complex medical assays without a laboratory and can easily be adapted for high throughput biological screening in remote and resource poor areas. PMID:21640067
Yang, Minghui; Sun, Steven; Kostov, Yordan; Rasooly, Avraham
Influenza infections are associated with high morbidity and mortality, carry the risk of pandemics, and pose a considerable economic burden worldwide. To improve the management of the illness, it is essential with accurate and fast point-of-care diagnostic tools for use in the field or at the patient's bedside. Conventional diagnostic methods are time consuming, expensive and require specialized laboratory facilities. We present a highly sensitive, highly specific, and low cost platform to test for acute virus infections in less than 15 min, employing influenza A virus (H1N1) as an example of its usability. An all polymer microfluidic system with a functionalized conductive polymer (PEDOT-OH:TsO) microelectrode array was developed and exploited for label free and real time electrochemical detection of intact influenza A virus (H1N1) particles. DNA aptamers with affinity for influenza A virus (H1N1) were linked covalently to the conductive polymer microelectrodes in the microfluidic channel. Based on changes in the impedance when virions were captured by immobilized probes, we could detect clinically relevant concentrations of influenza A virus (H1N1) in saliva. This is a new, stable and very sensitive point-of-care platform for detection and diagnostics of intact virus particles. PMID:23800609
Kiilerich-Pedersen, Katrine; Daprà, Johannes; Cherré, Solène; Rozlosnik, Noemi
Respiratory infections, particularly those caused by influenza viruses, represent the third-most important cause of death in the world due to infectious diseases. Nevertheless, despite the enormous publicity attracted by epidemics due to these viruses, laboratory diagnosis, documentation and recording of respiratory diseases is still unsatisfactory. Available diagnostic tests capable of providing results rapidly are either limited and insufficiently sensitive or highly sensitive and specific but insufficiently rapid. Considerable investment and research efforts have been made towards the development of new diagnostics for influenza A and B viruses and the Xpert(®) Flu assay (Cepheid(®), CA, USA) has emerged as one of the most promising. In this article, we review current knowledge of the Xpert Flu test, discuss its potential value as a point-of-care test and outline the potential leads for future development. PMID:24707995
Salez, Nicolas; Nougairede, Antoine; Ninove, Laetitia; Zandotti, Christine; de Lamballerie, Xavier; Charrel, Rémi N
Point-of-care (POC) diagnostics brings tests nearer to the site of patient care. The turnaround time is short, and minimal manual interference enables quick clinical management decisions. Growth in POC diagnostics is being continuously fueled by the global burden of cardiovascular and infectious diseases. Early diagnosis and rapid initiation of treatment are crucial in the management of such patients. This review provides the rationale for the use of POC tests in acute coronary syndrome, heart failure, human immunodeficiency virus, and tuberculosis. We also consider emerging technologies that are based on advanced nanomaterials and microfluidics, improved assay sensitivity, miniaturization in device design, reduced costs, and high-throughput multiplex detection, all of which may shape the future development of POC diagnostics.
Chan, Cangel Pui Yee; Mak, Wing Cheung; Cheung, Kwan Yee; Sin, King Keung; Yu, Cheuk Man; Rainer, Timothy H.; Renneberg, Reinhard
Research review paper Point-of-care assays for tuberculosis: Role of nanotechnology Keywords: Tuberculosis Point-of-care Nanotechnology Microfluidics Tuberculosis (TB) remains one of the most for TB diagnosis, and highlight the recent advances in nanotechnology and microfluidics that potentially
Accurate and inexpensive point-of-care (POC) tests are urgently needed to control sexually transmitted infection (STI) epidemics, so that patients can receive immediate diagnoses and treatment. Current POC assays for Chlamydia trachomatis and Neisseria gonorrhoeae perform inadequately and require better assays. Diagnostics for Trichomonas vaginalis rely on wet preparation, with some notable advances. Serological POC assays for syphilis can impact resource-poor settings, with many assays available, but only one available in the U.S. HIV POC diagnostics demonstrate the best performance, with excellent assays available. There is a rapid assay for HSV lesion detection; but no POC serological assays are available. Despite the inadequacy of POC assays for treatable bacterial infections, application of technological advances offers the promise of advancing POC diagnostics for all STIs. PMID:24484215
Gaydos, Charlotte; Hardick, Justin
This technical note presents a simple and disposable lab-on-a-tube (LOT) for point-of-care measurements of multiple analytes. LOT is a one-step device that can perform both sample collection and multi-sensing on-site. Sample collection is conducted by taking advantage of its inherent micro/macro channel structure while multi-sensing is conducted by integrated microsensors. This approach ensures reliable transportation of various samples into the testing area by either passive capillary force or active suction force, thus avoiding the need for a pump or injection components as used in lab-on-a-chip systems. The developed LOT (Diameter = 1 mm, Sensing length = 4.5 mm, Required sample volume = 3.5 microl) is capable of simultaneously quantifying the concentrations of glucose, lactate and oxygen in human serum samples. The result suggests the LOT hold great potential for many point-of-care applications. PMID:20480114
Li, Chunyan; Shutter, Lori A; Wu, Pei-Ming; Ahn, Chong H; Narayan, Raj K
Early efforts to use point-of-care clinical decision support (CDS) were limited to the use of prompts and reminders, which improved test ordering but not intermediate outcomes of care such as glucose, blood pressure, or lipid levels. More sophisticated diabetes CDS tools are now available that use electronic medical record data to provide patient-specific advice on medication use based on previous treatment, distance from goal, and other clinical data. These tools have shown modest but significant improvement in glucose and blood pressure control. Promising next-generation developments will include prioritizing clinical actions that have maximum benefit to a given patient at the point of care and developing effective methods to communicate CDS information to patients to better incorporate patient preferences in care decisions. PMID:23225213
O’Connor, Patrick J.; Desai, Jay; Butler, John; Kharbanda, Elyse; Sperl-Hillen, JoAnn M.
Rapid, sensitive and specific diagnostic assays play an indispensable role in determination of HIV infection stages and evaluation of efficacy of antiretroviral therapy. Recently, our laboratory developed a sensitive Europium nanoparticle-based microtiter-plate immunoassay capable of detecting target analytes at subpicogram per milliliter levels without the use of catalytic enzymes and signal amplification processes. Encouraged by its sensitivity and simplicity, we continued to miniaturize this assay to a microchip platform for the purpose of converting the benchtop assay technique to a point-of-care test. It was found that detection capability of the microchip platform could be readily improved using Europium nanoparticle probes. We were able to routinely detect 5 pg/mL (4.6 attomoles) of HIV-1 p24 antigen at a signal-to-blank ratio of 1.5, a sensitivity level reasonably close to that of microtiter-plate Europium nanoparticle assay. Meanwhile, use of the microchip platform effectively reduced sample/reagent consumption 4.5 fold and shortened total assay time 2 fold in comparison with microtiter plate assays. Complex matrix substance in plasma negatively affected the microchip assays and the effects could be minimized by diluting the samples before loading. With further improvements in sensitivity, reproducibility, usability, assay process simplification, and incorporation of portable time-resolved fluorescence reader, Europium nanoparticle immunoassay technology could be adapted to meet the challenges of point-of-care diagnosis of HIV or other health-threatening pathogens at bedside or in resource-limited settings. PMID:24880655
Liu, Jikun; Du, Bingchen; Zhang, Panhe; Haleyurgirisetty, Mohan; Zhao, Jiangqin; Ragupathy, Viswanath; Lee, Sherwin; DeVoe, Don L; Hewlett, Indira K
In order to limit the interference of HIV-1 cellular nucleic acids in estimating viral load (VL), the feasibility of leukodepletion of a small whole blood (WB) volume to eliminate only leukocyte cell content was investigated, using a selection of filters. The efficacy of leukocyte filtration was evaluated by counting, CD45 quantitative PCR and HIV-1 DNA quantification. Plasma HIV-1 was tested by RT-real-time PCR. A specific, miniaturised, filter was developed and tested for leukocyte and plasma virus retention, WB sample dilution and filtration parameters in HIV-1-spiked WB samples. This device proved effective to retain >99.9% of white blood cells in 100?l of WB without affecting plasma VL. The SAMBA sample preparation chemistry was adapted to use a leukodepleted WB sample for VL monitoring using the point of care SAMBA1 semi-automated system. The clinical performance of the assay was evaluated by testing 207 consecutive venous EDTA WB samples from HIV-1 infected patients attending a CD4 testing clinic. Most patients were on anti-retroviral treatment (ART) but their VL status was unknown. When compared to the Roche COBAS AmpliPrep/COBAS TaqMan HIV-1 test, the new SAMBA assay had a concordance of 96.5%. The use of the SAMBA system with a VL test for WB might contribute to HIV-1 ART management and reduce loss-to-follow-up rates in resource-limited settings. PMID:25428162
Titchmarsh, Logan; Zeh, Clement; Verpoort, Thierry; Allain, Jean-Pierre; Lee, Helen
...2007D-0290] Draft Guidance for Industry: Cell Selection Devices for Point of Care Production...Manipulated Autologous Peripheral Blood Stem Cells; Withdrawal of Draft Guidance AGENCY...entitled ``Draft Guidance for Industry: Cell Selection Devices for Point of Care...
The use of in vitro diagnostic devices is transitioning from the laboratory to the primary care setting to address early disease detection needs. Time critical viral diagnoses are often made without support due to the experimental time required in today's standard tests. Available rapid point of care (POC) viral tests are less reliable, requiring a follow-on confirmatory test before conclusions can be drawn. The development of a reliable POC viral test for the primary care setting would decrease the time for diagnosis leading to a lower chance of transmission and improve recovery. The single particle interferometric reflectance imaging sensor (SP-IRIS) has been shown to be a sensitive and specific-detection platform in serum and whole blood. This paper presents a step towards a POC viral assay through a SP-IRIS prototype with automated data acquisition and analysis and a simple, easy-to-use software interface. Decreasing operation complexity highlights the potential of SP-IRIS as a sensitive and specific POC diagnostic tool. With the integration of a microfluidic cartridge, this automated instrument will allow an untrained user to run a sample-to-answer viral assay in the POC setting. PMID:24271115
Reddington, Alexander P; Trueb, Jacob T; Freedman, David S; Tuysuzoglu, Ahmet; Daaboul, George G; Lopez, Carlos A; Karl, W Clem; Connor, John H; Fawcett, Helen; Ünlu, M Selim
The use of in vitro diagnostic devices is transitioning from the laboratory to the primary care setting to address early disease detection needs. Time critical viral diagnoses are often made without support due to the experimental time required in today’s standard tests. Available rapid point of care (POC) viral tests are less reliable, requiring a follow-on confirmatory test before conclusions can be drawn. The development of a reliable POC viral test for the primary care setting would decrease the time for diagnosis leading to a lower chance of transmission and improve recovery. The single particle interferometric reflectance imaging sensor (SP-IRIS) has been shown to be a sensitive and specific-detection platform in serum and whole blood. This paper presents a step towards a POC viral assay through a SP-IRIS prototype with automated data acquisition and analysis and a simple, easy-to-use software interface. Decreasing operation complexity highlights the potential of SP-IRIS as a sensitive and specific POC diagnostic tool. With the integration of a microfluidic cartridge, this automated instrument will allow an untrained user to run a sample-to-answer viral assay in the POC setting. PMID:24271115
Reddington, Alexander P.; Trueb, Jacob T.; Freedman, David S.; Tuysuzoglu, Ahmet; Daaboul, George G.; Lopez, Carlos A.; Karl, W. Clem; Connor, John H.; Fawcett, Helen; Ünlü, M. Selim
WHO recommendations for dengue diagnosis require laboratory facilities. Antibody-based rapid diagnostic tests (RDTs) have performed poorly, and clinical diagnosis remains the mainstay in dengue-endemic countries. We evaluated a combination antigen-antibody RDT for point-of-care testing in a high-prevalence setting. In this prospective cohort study, adults were enrolled from a tertiary infectious disease centre for evaluation of undifferentiated febrile illness from October 2011 to May 2012. SD Bioline Dengue Duo was evaluated at point-of-care against a WHO-based reference standard of viral isolation, RT-PCR, NS1-, IgM-, and IgG-ELISA. 246 adults were enrolled (median age 34 years, range 18–69), of which 197 could be confirmed definitively as either dengue or non-dengue. DENV-2 was the predominant serotype (79.5%) and the ratio of primary to secondary cases was 1?1.1. There were no test failures and minimal interobserver variation with a Fleiss’ kappa of 0.983 (95% CI 0.827–1.00). Overall sensitivity and specificity were 93.9% (95% CI 88.8–96.8%) and 92.0% (95% CI 81.2–96.9%) respectively. Using WHO clinical criteria alone for diagnosis had similar sensitivities (95.9%, 95% CI 91.4–98.1%) and lower specificities (20.0%, 95% CI 11.2–33.0%). No significant difference in performance was found when testing early versus late presenters, primary versus secondary cases, or DENV-1 versus DENV-2 infections. The use of a combination RDT fulfills WHO ASSURED criteria for point-of-care testing and can enhance dengue diagnosis in an endemic setting. This has the potential to markedly improve clinical management of dengue in the field. PMID:24646519
Gan, Victor C.; Tan, Li-Kiang; Lye, David C.; Pok, Kwoon-Yong; Mok, Shi-Qi; Chua, Rachel Choon-Rong; Leo, Yee-Sin; Ng, Lee-Ching
Background To date, the use of traditional nucleic acid amplification tests (NAAT) for detection of HIV-1 DNA or RNA has been restricted to laboratory settings due to time, equipment, and technical expertise requirements. The availability of a rapid NAAT with applicability for resource-limited or point-of-care (POC) settings would fill a great need in HIV diagnostics, allowing for timely diagnosis or confirmation of infection status, as well as facilitating the diagnosis of acute infection, screening and evaluation of infants born to HIV-infected mothers. Isothermal amplification methods, such as reverse-transcription, loop-mediated isothermal amplification (RT-LAMP), exhibit characteristics that are ideal for POC settings, since they are typically quicker, easier to perform, and allow for integration into low-tech, portable heating devices. Methodology/Significant Findings In this study, we evaluated the HIV-1 RT-LAMP assay using portable, non-instrumented nucleic acid amplification (NINA) heating devices that generate heat from the exothermic reaction of calcium oxide and water. The NINA heating devices exhibited stable temperatures throughout the amplification reaction and consistent amplification results between three separate devices and a thermalcycler. The performance of the NINA heaters was validated using whole blood specimens from HIV-1 infected patients. Conclusion The RT-LAMP isothermal amplification method used in conjunction with a chemical heating device provides a portable, rapid and robust NAAT platform that has the potential to facilitate HIV-1 testing in resource-limited settings and POC. PMID:22384022
Curtis, Kelly A.; Rudolph, Donna L.; Nejad, Irene; Singleton, Jered; Beddoe, Andy; Weigl, Bernhard; LaBarre, Paul; Owen, S. Michele
Stratifying risk of patients with acute coronary syndrome (ACS) in the emergency department (ED) remains a frequent challenge. When ST-elevation criteria are absent, current recommendations rely upon insensitive and time-intensive methods such as the electrocardiogram and cardiac enzyme testing. Here, we report on a series of cases, where emergency physicians used a simplified model for identifying regional wall motion abnormalities by point-of-care echocardiography in patients presenting with chest pain to the ED. With the use of a simplified model described herein, high-risk patients with ACS were identified rapidly in a cohort usually difficult to risk stratify. PMID:24745875
Frenkel, Oron; Riguzzi, Christine; Nagdev, Arun
During perioperative treatment of coagulopathic patients the so-called Point-of-Care (POC) analyses enable more rapidly available and more comprehensive hemostatic analyses compared to routinely performed conventional coagulation testing, such as activated partial thromboplastin time (aPTT), international normalized ratio (INR), fibrinogen concentration and platelet count. In this review article a hemotherapy algorithm is presented which is based on viscoelastic and aggregometric POC measurements. The algorithm was designed double sided and consists of a general and a special part. The general part contains boxes and fields for sociodemographic data and gives general recommendations for coagulation management and therapy specifications for particular patient collectives and presents proposals for emergency reversal of anticoagulation therapy. The special part refers to basic physiological conditions for hemostasis and asks for measurement results of clot initiation, clot firmness, clot stability and platelet function analyses. Reference values were defined for each parameter and therapeutic options are presented. In cases of persistent coagulopathy despite algorithm-conform therapy, the algorithm could be run through once again. Finally, the algorithm presents therapeutic options for an ultima ratio therapy approach. PMID:23793973
Weber, C F; Zacharowski, K; Brün, K; Volk, T; Martin, E O; Hofer, S; Kreuer, S
Preconcentration of pathogens from patient samples represents a great challenge in point-of-care (POC) diagnostics. Here, a low-cost, rapid, and portable agarose-based microfluidic device was developed to concentrate biological fluid from micro- to picoliter volume. The microfluidic concentrator consisted of a glass slide simply covered by an agarose layer with a binary tree-shaped microchannel, in which pathogens could be concentrated at the end of the microchannel due to the capillary effect and the strong water permeability of the agarose gel. The fluorescent Escherichia coli strain OP50 was used to demonstrate the capacity of the agarose-based device. Results showed that 90% recovery efficiency could be achieved with a million-fold volume reduction from 400 ?L to 400 pL. For concentration of 1 × 10(3) cells mL(-1) bacteria, approximately ten million-fold enrichment in cell density was realized with volume reduction from 100 ?L to 1.6 pL. Urine and blood plasma samples were further tested to validate the developed method. In conjugation with fluorescence immunoassay, we successfully applied the method to the concentration and detection of infectious Staphylococcus aureus in clinics. The agarose-based microfluidic concentrator provided an efficient approach for POC detection of pathogens. PMID:25264815
Li, Yiwei; Yan, Xinghua; Feng, Xiaojun; Wang, Jie; Du, Wei; Wang, Yachao; Chen, Peng; Xiong, Liang; Liu, Bi-Feng
With noncommunicable diseases (NCDs) now constituting the majority of global mortality, there is a growing need for low-cost, noninvasive methods to diagnose and treat this class of diseases, especially in resource-limited settings. Molecular biomarkers combined with low-cost point-of-care assays constitute a potential solution for diagnosing NCDs, but the dearth of naturally occurring, predictive markers limits this approach. Here, we describe the design of exogenous agents that serve as synthetic biomarkers for NCDs by producing urinary signals that can be quantified by a companion paper test. These synthetic biomarkers are composed of nanoparticles conjugated to ligand-encoded reporters via protease-sensitive peptide substrates. Upon delivery, the nanoparticles passively target diseased sites, such as solid tumors or blood clots, where up-regulated proteases cleave the peptide substrates and release reporters that are cleared into urine. The reporters are engineered for detection by sandwich immunoassays, and we demonstrate their quantification directly from unmodified urine; furthermore, capture antibody specificity allows the probes to be multiplexed in vivo and quantified simultaneously by ELISA or paper lateral flow assay (LFA). We tailor synthetic biomarkers specific to colorectal cancer, a representative solid tumor, and thrombosis, a common cardiovascular disorder, and demonstrate urinary detection of these diseases in mouse models by paper diagnostic. Together, the LFA and injectable synthetic biomarkers, which could be tailored for multiple diseases, form a generalized diagnostic platform for NCDs that can be applied in almost any setting without expensive equipment or trained medical personnel. PMID:24567404
Warren, Andrew D.; Kwong, Gabriel A.; Wood, David K.; Lin, Kevin Y.; Bhatia, Sangeeta N.
An automated point-of-care (POC) immunodetection system for immunological detection of staphylococcal enterotoxin B (SEB) was designed, fabricated, and tested. The system combines several elements: (i) enzyme-linked immunosorbent assay-lab-on-a-chip (ELISA-LOC) with fluidics, (ii) a charge-coupled device (CCD) camera detector, (iii) pumps and valves for fluid delivery to the ELISA-LOC, (iv) a computer interface board, and (v) a computer for controlling the fluidics, logging, and data analysis of the CCD data. The ELISA-LOC integrates a simple microfluidic system into a miniature 96-well sample plate, allowing the user to carry out immunological assays without a laboratory. The analyte is measured in a sandwich ELISA assay format combined with a sensitive electrochemiluminescence (ECL) detection method. Using the POC system, SEB, a major foodborne toxin, was detected at concentrations as low as 0.1 ng/ml. This is similar to the reported sensitivity of conventional ELISA. The open platform with simple modular fluid delivery automation design described here is interchangeable between detection systems, and because of its versatility it can also be used to automate many other LOC systems, simplifying LOC development. This new POC system is useful for carrying out various immunological and other complex medical assays without a laboratory and can easily be adapted for high-throughput biological screening in remote and resource-poor areas. PMID:21640067
Yang, Minghui; Sun, Steven; Kostov, Yordan; Rasooly, Avraham
Objectives The Massachusetts Veterans Epidemiology Research and Information Center in collaboration with the Stanford Center for Innovative Study Design set out to test the feasibility of a new method of evidence generation. The first pilot of a point-of-care clinical trial (POCCT), adding randomization and other study processes to an electronic medical record (EMR) system, was launched to compare the effectiveness of two insulin regimens. Materials and Methods Existing functionalities of the Veterans Affairs (VA) computerized patient record system (CPRS)/veterans health information systems and technology architecture (VISTA) were modified to support the activities of a randomized controlled trial including enrolment, randomization, and longitudinal data collection. Results The VA's CPRS/VISTA was successfully adapted to support the processes of a clinical trial and longitudinal study data are being collected from the medical record automatically. As of 30 June 2011, 55 of the 67 eligible patients approached received a randomized intervention. Discussion The design of CPRS/VISTA made integration of study workflows and data collection possible. Institutions and investigators considering similar designs must carefully map clinical workflows and clinical trial workflows to EMR capabilities. POCCT study teams are necessarily interdisciplinary and interdepartmental. As a result, executive sponsorship is critical. Conclusion POCCT represent a promising new method for conducting clinical science. Much work is needed to understand better the optimal uses and designs for this new approach. Next steps include focus groups to measure patient and clinician perceptions, multisite deployment of the current pilot, and implementation of additional studies. PMID:22366293
Ferguson, Ryan; Goryachev, Sergey; Woods, Patricia; Sabin, Thomas; O'Neil, Joseph; Conrad, Chester; Gillon, Joseph; Escalera, Jasmine; Brophy, Mary; Lavori, Phillip; Fiore, Louis
Neonatal sepsis is still a leading cause of death among newborns. Therefore a protein-microarray for point-of-care testing that simultaneously quantifies the sepsis associated serum proteins IL-6, IL-8, IL-10, TNF alpha, S-100, PCT, E-Selectin, CRP and Neopterin has been developed. The chip works with only a 4 ?L patient serum sample and hence minimizes excessive blood withdrawal from newborns. The 4 ?L patient samples are diluted with 36 ?L assay buffer and distributed to four slides for repetitive measurements. Streptavidin coated magnetic particles that act as distinct stirring detection components are added, not only to stir the sample, but also to detect antibody antigen binding events. We demonstrate that the test is complete within 2.5 h using a single step assay. S-100 conjugated to BSA is spotted in increasing concentrations to create an internal calibration. The presented low volume protein-chip fulfills the requirements of point-of-care testing for accurate and repeatable (CV < 14%) quantification of serum proteins for the diagnosis of neonatal sepsis. PMID:22438722
Buchegger, Patricia; Sauer, Ursula; Toth-Székély, Hedvig; Preininger, Claudia
We developed an automated point-of-care diagnostic instrument that is capable of analyzing nasal swab samples for the presence of respiratory diseases. This robust instrument, called FluIDx, performs autonomous multiplexed RT-PCR reactions that are analyzed by microsphere xMAP technology. We evaluated the performance of FluIDx, in comparison rapid tests specific for influenza and respiratory syncytial virus, in a clinical study performed at the UC Davis Medical Center. The clinical study included samples positive for RSV (n = 71), influenza A (n = 16), influenza B (n = 4), adenovirus (n = 5), parainfluenza virus (n = 2), and 44 negative samples, according to a composite reference method. FluIDx and the rapid tests detected 85.9% and 62.0% of the RSV positive samples, respectively. Similar sensitivities were recorded for the influenza B samples; whereas the influenza A samples were poorly detected, likely due to the utilization of an influenza A signature that did not accurately match currently circulating influenza A strains. Data for all pathogens were compiled and indicate that FluIDx is more sensitive than the rapid tests, detecting 74.2% (95% C.I. of 64.7-81.9%) of the positive samples in comparison to 53.6% (95% C.I. of 43.7-63.2%) for the rapid tests. The higher sensitivity of FluIDx was partially offset by a lower specificity, 77.3% versus 100.0%. Overall, these data suggest automated flow-through PCR-based instruments that perform multiplexed assays can successfully screen clinical samples for infectious diseases.
Regan, J F; Letant, S E; Adams, K L; Mahnke, R C; Nguyen, N T; Dzenitis, J M; Hindson, B J; Hadley, D R; Makarewicz, T J; Henderer, B D; Breneman, J W; Tammero, L F; Ortiz, J I; Derlet, R W; Cohen, S; Colston, W W; McBride, M T; Birch, J M
One of the key elements in point-of-care (POC) diagnostic test instrumentation is the optical system required for signal detection and / or imaging. Many tests which use fluorescence, absorbance, or colorimetric optical signals are under development for management of infectious diseases in resource limited settings, where the overall size and cost of the device is of critical importance. At present, high-performance lenses are expensive to fabricate and difficult to obtain commercially, presenting barriers for developers of in vitro POC tests or microscopic image-based diagnostics. We recently described a compact “hybrid” objective lens incorporating both glass and plastic optical elements, with a numerical aperture of 1.0 and field-of-view of 250 m. This design concept may potentially enable mass-production of high-performance, low-cost optical systems which can be easily incorporated in the readout path of existing and emerging POC diagnostic assays. In this paper, we evaluate the biological imaging performance of these lens systems in three broad POC diagnostic application areas; (1) bright field microscopy of histopathology slides, (2) cytologic examination of blood smears, and (3) immunofluorescence imaging. We also break down the fabrication costs and draw comparisons with other miniature optical systems. The hybrid lenses provided images with quality comparable to conventional microscopy, enabling examination of neoplastic pathology and infectious parasites including malaria and cryptosporidium. We describe how these components can be produced at below $10 per unit in full-scale production quantities, making these systems well suited for use within POC diagnostic instrumentation. PMID:24097204
Pierce, Mark C.; Weigum, Shannon E.; Jaslove, Jacob M.; Richards-Kortum, Rebecca; Tkaczyk, Tomasz S.
The difficulty of rapid, definitive diagnosis of myocardial ischemia leads to unnecessary hospital admissions and treatment delays. Previously, decreased metal binding affinity in human serum was investigated as a marker for myocardial ischemia. Polymerized Crystalline Colloidal Array (PCCA) sensors for Ni2+ may be useful in developing a point-of-care test to determine metal binding affinity in plasma and to help rule out myocardial ischemia. PCCA sensors for Ni2+, with 5-amino-8-hydroxyquinoline as a chelating agent, were tested in aqueous solutions and diluted human plasma. The peak wavelength diffracted by the sensors was monitored by reflectance spectrometry and correlated with Ni2+ concentration. The PCCA sensors show a linear response to aqueous Ni2+ concentrations between 0.2 and 1.0 mmol L(-1), and can detect changes in free Ni2+ concentration of <60 micromol L(-1). The sensors respond at physiologic pH and can be reversibly dehydrated. The PCCA sensors developed here can report on free Ni2+ concentration in the presence of human plasma. These sensors can be used to detect a decrease in the Ni2+ affinity of plasma proteins, which may indicate recent myocardial ischemia. PCCA sensors offer a practical approach to rapid, point-of-care detection of a proposed biochemical signature of myocardial ischemia. PMID:18299754
Baca, Justin T; Finegold, David N; Asher, Sanford A
Background. A nonrecognized pneumothorax (PTX) may become a life-threatening tension PTX. A reliable point-of-care diagnostic tool could help in reduce this risk. For this purpose, we investigated the feasibility of the use of the PneumoScan, an innovative device based on micropower impulse radar (MIR). Patients and Methods. addition to a standard diagnostic protocol including clinical examination, chest X-ray (CXR), and computed tomography (CT), 24 consecutive patients with chest trauma underwent PneumoScan testing in the shock trauma room to exclude a PTX. Results. The application of the PneumoScan was simple, quick, and reliable without functional disorder. Clinical examination and CXR each revealed one and PneumoScan three out of altogether four PTXs (sensitivity 75%, specificity 100%, positive predictive value 100%, and negative predictive value 95%). The undetected PTX did not require intervention. Conclusion. The PneumoScan as a point-of-care device offers additional diagnostic value in patient management following chest trauma. Further studies with more patients have to be performed to evaluate the diagnostic accuracy of the device. PMID:24187624
Lindner, T.; Conze, M.; Albers, C. E.; Leidel, B. A.; Levy, P.; Kleber, C.; De Moya, M.; Exadaktylos, A.; Stoupis, C.
Electronic data systems are being implemented in resource-poor HIV clinics to track and improve patient care. The great majority of these systems rely on paper forms and retrospective data entry, while a few have chosen to deploy point-of-care systems to collect data in real time. This study describes a comparison of data quality between these two approaches. PMID:18999092
Douglas, Gerald; McKay, Michael; Bwanali, Mwatha; Gadabu, Oliver; Mumba, Soyapi; Gondwe, Alex
to administration. Administration errors, leading to non-compliance to correct medication directions, contributeTR-IIS-07-004 Point-of-Care Support for Error-Free Medication Process J. W. S. Liu, C. S. Shih, P for prevention and reduction of medication errors. The focus of this paper is on devices and tools that support
A cost-effective and highly sensitive portable diagnostic device is needed to enable much more widespread monitoring of health conditions in disease prevention, detection, and control. Miniaturized and easy-to-operate devices can reduce the inherent costs and inefficiencies associated with healthcare testing in central laboratories. Hence, clinicians are beginning to use point of care (POC) testing and flexible clinical chemistry testing devices which are beneficial for the patient. In our work, a low-cost and simple autonomous microfluidic device for biochemical detection was developed. The pumpless capillary system with capillary stop valves and trigger valves is fabricated on a silicon (Si) wafer and then bonded with the modified polydimethylsiloxane (PDMS) cover. The key point of this study is the change of the surface contact angle of the PDMS to achieve the functionalities such as timing features (capillary-driven stop valve) and basic logical functions (trigger valves). The polydimethylsiloxane-ethylene oxide polymer (PDMS-b-PEO) is utilized as a surfactant additive to make the PDMS hydrophilic. The contact angle of the modified PDMS can be adjusted from 80.9° to 21.5° with different mixing ratios. The contact angles of PEO-PDMS accepted in this work are from 80.9° to 58.5° to bring the capillary channel and valve into effect. This autonomous capillary-driven device with good microfluidic flow manipulation can be widely applied to a number of microfluidic devices and pumpless fluidic actuation mechanisms, which is suitable for cost-effective diagnostic tools in the biomedical analysis and POC testing applications. Another obstacle for miniaturization of the bio-detection system is the optical detector. We developed a novel, highly sensitive and miniaturized detector. It integrates a light source--light emitting diode (LED), all necessary optical components, and a photodiode with preamplifier into one package about 2 cm x 2 cm x 2 cm, especially for the applications of lab-on-a-chip (LOC), portable bio-detection system and POC diagnostic system. The size of this detector is smaller than the existing miniaturized detector of the size 5 cm x 5 cm x 5 cm. The fluorescence dye 5-Carboxyfluorescein (5-FAM) dissolved into the solvent DMSO (Dimethyl Sulfoxide) and diluted with DI water was used as the testing solution samples. The prototype has been tested to prove a remarkable sensitivity at pico-scale molar, around 1.08 pM, which is the highest sensitivity by now. It is higher than the current limit of detection at 1.96 nm, which will be presented in detail in the latter section.
This article develops a framework for understanding how financial and nonfinancial incentives can complicate point-of-care decision-making by physicians, leading to the overuse or underuse of healthcare services. By examining the types of decisions that clinicians and patients make at the point-of-care, the framework clarifies how incentives can distort physicians' decisions about testing, diagnosis and treatment, as well as efforts to enhance patient adherence. The analysis highlights contributing factors that promote and impede evidence-based decision-making, using examples from the 'Choosing Wisely' program. It concludes with a summary of how the existing fee-for-service payment system in the USA may contribute to the problems of over- and under-testing, diagnosis and treatment, highlighted through the efforts of Choosing Wisely. PMID:24236623
Rich, Eugene C; Lake, Timothy K; Valenzano, Christal Stone; Maxfield, Myles M
Current methods used to measure protein expression on microarrays, such as labeled fluorescent imaging, are not well suited for real-time, diagnostic measurements at the point of care. Studies have shown that microelectrical sensors utilizing silica nanowire, impedimetric, surface acoustic wave, magnetic nanoparticle and microantenna technologies have the potential to impact disease diagnosis by offering sensing characteristics that rival conventional sensing techniques. Their ability to transduce protein binding events into electrical signals may prove essential for the development of next-generation point-of-care devices for molecular diagnostics, where they could be easily integrated with microarray, microfluidic and telemetry technologies. However, common limitations associated with the microelectrical sensors, including problems with sensor fabrication and sensitivity, must first be resolved. This review describes governing technical concepts and provides examples demonstrating the use of various microelectrical sensors in the diagnosis of disease via protein biomarkers. PMID:19817557
Arruda, David L; Wilson, William C; Nguyen, Crystal; Yao, Qi W; Caiazzo, Robert J; Talpasanu, Ilie; Dow, Douglas E; Liu, Brian C-S
In clinical practice, pharmacists play a very important role in identifying and correcting medication discrepancies as older patients move across transition points of care. With increasing complexity of health care needs of older people, these discrepancies are likely to increase. The major concern with identifying and correcting medication discrepancies is that medication reconciliation is considered a retrospective problem - that is, dealing with medication discrepancies after they have occurred. It is argued here that a more proactive stance should be taken where doctors, nurses and pharmacists collectively work together to prevent medication discrepancies from happening in the first place. Improved involvement of patients and family members will help to facilitate better management of medications across transition points of care. Efficient use of information technology aids, such as electronic medication reconciliation tools, should also assist with organizational systems problems associated with the working culture, heavy workloads, and staff and skill mix of health professionals. PMID:25455760
Manias, Elizabeth; Hughes, Carmel
OBJECTIVES: The purpose of this study was to evaluate the effect of a research training program on clinicians’ knowledge, attitudes, and practices related to research and evidence-based practice (EBP). BACKGROUND: EBP has been shown to improve patient care and outcomes. Innovative approaches are needed to overcome individual and organizational barriers to EBP. METHODS: Mixed-methods design was used to evaluate a research training intervention with point-of-care clinicians in a Canadian urban health organization. Participants completed the Knowledge, Attitudes, and Practice Survey over 3 timepoints. Focus groups and interviews were also conducted. RESULTS: Statistically significant improvement in research knowledge and ability was demonstrated. Participants and administrators identified benefits of the training program, including the impact on EBP. CONCLUSIONS: Providing research training opportunities to point-of-care clinicians is a promising strategy for healthcare organizations seeking to promote EBP, empower clinicians, and showcase excellence in clinical research. PMID:25390076
Black, Agnes T.; Balneaves, Lynda G.; Garossino, Candy; Puyat, Joseph H.; Qian, Hong
Due to the fact that health care professionals in Malawi are often overstretched, the use and quality of health data can be compromised. The Malawi Health Management Information System (HMIS) has streamlined data collection and reporting and increased the use of data to improve care. Obstacles remain, including incomplete reporting and low staff morale. With the Baobab Health Trust and the Malawi Ministry of Health, Partners In Health piloted an innovative point-of-care data system for primary care that functions alongside OpenMRS, an open source medical record platform. The system has given access to a patient-level primary care dataset in real time. Initial results highlight some of the benefits of a point-of-care system such as improved data quality, emphasize the importance of sharing data with clinical practitioners, and shed light on how this approach could strengthen HMIS. PMID:20841657
Waters, Evan; Rafter, Jeff; Douglas, Gerald P; Bwanali, Mwatha; Jazayeri, Darius; Fraser, Hamish S F
The biomedical field publishes a huge volume of articles every year and most of them are now available online as PDF full-texts.There is still no an effective search mechanisim that could locate the full-text articles very narrowly matching the users preference quickly. Such a mechanisim can be important for many real-time applications such as information at point of care for
Massuod Alatrash; Hao Ying; Peter Dews; Ming Dong; Wendy Wu; Michael Massanari
Cardiovascular disease remains the leading cause of death in the world and continues to serve as the major contributor to healthcare costs. Likewise, there is an ever-increasing need and demand for novel and more efficient diagnostic tools for the early detection of cardiovascular disease, especially at the point-of-care (POC). This article reviews the programmable bio-nanochip (P-BNC) system, a new medical microdevice approach with the capacity to deliver both high performance and reduced cost. This fully integrated, total analysis system leverages microelectronic components, microfabrication techniques, and nanotechnology to noninvasively measure multiple cardiac biomarkers in complex fluids, such as saliva, while offering diagnostic accuracy equal to laboratory-confined reference methods. This article profiles the P-BNC approach, describes its performance in real-world testing of clinical samples, and summarizes new opportunities for medical microdevices in the field of cardiac diagnostics. PMID:22891104
Pierre, Floriano N.; Sanchez, Ximena; Li, Luanyi; Hocquard, Kyle; Patton, Aaron; Muldoon, Rachna; Miller, Craig S.; Ebersole, Jeffrey L.; Redding, Spencer; Yeh, Chih-Ko; Furmaga, Wieslaw B.; Wampler, David A.; Bozkurt, Biykem; Ballantyne, Christie M.; McDevitt, John T.
Millions of patients worldwide are receiving anticoagulant therapy to treat hypercoagulable diseases. While standard testing is still performed in the central laboratory, point-of-care (POC) diagnostics are being developed due to the increasing number of patients requiring long-term anticoagulation and with a need for more personalized and targeted therapy. Many POC devices on the market focus on clot measurement, a technique which is limited in terms of variability, highlighting the need for more reliable assays of anticoagulant status. The anti-Xa assay, a factor specific optical assay, was developed to measure the extent to which exogenous factor Xa (FXa) is inhibited by heparinantithrombin complexes. We have developed a novel microfluidic device and assay for monitoring the effect of heparin anticoagulant therapy at the point-of-care. The assay which was also developed in our institute is based on the anti-Xa assay principle but uses fluorescence as the method of detection. Our device is a disposable laminate microfluidic strip, fabricated from the cyclic polyolefin (COP), Zeonor®, which is extremely suitable for application to fluorescent device platforms. We present data on the execution of the anti-Xa assay in this microfluidic format, demonstrating that the assay can be used to measure heparin in human plasma samples from 0 to 0.8 U/ml, with average assay reproducibility of 8% and a rapid result obtained within 60 seconds. Results indicate that with further development, the fluorogenic anti-Xa assay and device could become a successful method for monitoring anticoagulant therapy.
Harris, Leanne F.; Rainey, Paul; Castro-López, Vanessa; O'Donnell, James S.; Killard, Anthony J.
AIM: To determine the diagnostic accuracy of a new point-of-care assay detecting anti-deamidated gliadin peptides in celiac disease (CD) patients. METHODS: One-hundred-and-twelve patients (age range: 1.8-79.2 years old) with clinical symptoms suggestive of CD and/or first-degree relatives (FDR) of CD patients (n = 66), and confirmed CD on a gluten-free diet (GFD) (n = 46), were prospectively enrolled in the study at Gastroenterology outpatient clinics for adult patients and from the Gastroenterology Consultation Ward at the Pediatric Department of the University Hospital of Geneva. Written informed consent was obtained from all subjects enrolled. The study received approval from the local ethics committee. The original CD diagnosis had been based on serum-positive IgA anti-tissue transglutaminase enzyme-linked immunosorbent assay (ELISA) (QuantaLite™, Inova Diagnostics, San Diego, CA, United States) and on biopsy results. Serum samples from all study participants were tested by the new CD lateral flow immunochromatographic assay (CD-LFIA) device, Simtomax® Blood Drop (Augurix SA, BioArk, Monthey, Switzerland) to detect immunoglobulin (Ig)A and IgG antibodies against deamidated gliadin peptides. The diagnostic performance was evaluated using receiver operating characteristic curves with 95%CIs. A cut-off of 2 on the Rann colorimetric scale was used to calculate the device’s sensitivity and specificity. RESULTS: CD-LFIA was highly accurate in detecting untreated celiac patients. In the group of patients with CD symptoms and/or FDR, eight new cases of CD were detected by ELISA and biopsy. All of these new cases were also correctly identified by CD-LFIA. The test yielded four false positive and four false negative results. The false positive results were all within the groups with clinical symptoms suggestive of CD and/or FDR, whereas the false negative results were all within the GFD group. The test yeld a sensitivity of 78.9% (95%CI: 54.4-93.9) and specificity of 95.7% (95%CI: 89.4-98.8), and the area under the curve reached 0.893 (95%CI: 0.798-0.988). The Kappa coefficient, calculated according to the values obtained by two readers from the same device, was of 0.96 (SE: 0.06). When the GFD patients were excluded from the analysis, the area under the curve reached 0.989 (95%CI: 0.971-1.000) and the Kappa coefficient, calculated according to the values obtained by two readers from the same device, became 0.96 (SE: 0.07). Furthermore, using the Rann scale cut-off of 2 without the GFD patients, sensitivity was 100% and specificity was 93.1% (95%CI: 83.3-98.1). CONCLUSION: The new CD-LFIA rapid screening test shows good diagnostic accuracy, sensitivity and specificity, and may rule out CD in patients with CD-related symptoms. PMID:23964145
Benkebil, Faiza; Combescure, Christophe; Anghel, Silvia I; Besson Duvanel, Cécile; Schäppi, Michela G
Stakeholders agree that supporting high-quality diagnostics is essential if we are to continue to make strides in the fight against human immunodeficiency virus (HIV) and tuberculosis. Despite the need to strengthen existing laboratory infrastructure, which includes expanding and developing new laboratories, there are clear diagnostic needs where conventional laboratory support is insufficient. Regarding HIV, rapid point-of-care (POC) testing for initial HIV diagnosis has been successful, but several needs remain. For tuberculosis, several new diagnostic tests have recently been endorsed by the World Health Organization, but a POC test remains elusive. Human immunodeficiency virus and tuberculosis are coendemic in many high prevalence locations, making parallel diagnosis of these conditions an important consideration. Despite its clear advantages, POC testing has important limitations, and laboratory-based testing will continue to be an important component of future diagnostic networks. Ideally, a strategic deployment plan should be used to define where and how POC technologies can be most efficiently and cost effectively integrated into diagnostic algorithms and existing test networks prior to widespread scale-up. In this fashion, the global community can best harness the tremendous capacity of novel diagnostics in fighting these 2 scourges. PMID:22457286
Peter, Trevor F.; Cavanaugh, Sean; Piatek, Amy S.; Young, Gloria J.; Alexander, Heather; Coggin, William; Domingo, Gonzalo J.; Ellenberger, Dennis; Ermantraut, Eugen; Jani, Ilesh V.; Katamba, Achilles; Palamountain, Kara M.; Essajee, Shaffiq; Dowdy, David W.
We report the implementation of the bokeh microscopy scheme in microfluidic settings for future applications in point-of-care microchannel monitoring in highly resource-limited environments. We realize the functional integration using a single polymer microlens fabricated over the microchannel. The inherent simplicity of the bokeh microscopy enables image capturing with an off-the-shelf camera. Our pilot devices exhibit 10???40 of magnification and 67???252 ?m of field-of-view extent, confirming their utility for monitoring 50???100 ?m microchannels carrying 10???50 ?m objects. PMID:25653063
Paek, Jungwook; Kim, Jaeyoun
A vast amount of important information on the various rheumatic diseases that the rheumatologist treats is available in the medical records derived from the patient consultation. Until recently, it has been difficult to assemble and interpret this data. Moreover, the 'everyday' rheumatologist seeing the 'everyday' patient often does not contribute data to better understanding of 'everyday' clinical issues. We discuss an approach to this problem by describing a blending of a customised electronic medical record with a consortium of like-minded clinicians. We feel that this approach demonstrates the powerful potential for targeted point of care data collection in rheumatology research and patient management. PMID:25365106
Tymms, K; Littlejohn, G
In the post-genomic era, ever-advancing capabilities in DNA detection and analysis have become vital to the detection of infectious diseases and the diagnosis of genetic abnormalities and inheritable diseases. The benefit of such capabilities, however, has yet to reach patients outside of centralized facilities. There thus exists an increasing need to decentralize DNA detection methods and to administer such diagnostics at the "point of care." Electrochemical-based DNA sensors present a compelling approach, but have yet to deliver satisfactory sensitivity, specificity, miniaturization, and real-time monitoring capability to meet the demand of point-of-care diagnostics. Motivated by their potential and their current limitations, in this dissertation, we present a series of strategies that we have undertaken in order to address the key shortcomings of electrochemical DNA sensors and advance them toward point-of-care applications. First, we report a single-step, single reagent, label-free, isothermal electrochemical DNA sensor based on the phenomenon of enzyme catalyzed target recycling amplification. Using this technique, we achieve improved detection limit in comparison to hybridization-based sensors without amplification. We also demonstrate greater than 16-fold amplification of signal at low target concentrations. Next, we present a novel electrochemical DNA sensor that detects single-nucleotide mismatched targets with unprecedented "polarity-switching" responses. This "bipolar" sensor employs a surface-bound and redox-modified (methylene blue) DNA probe architecture, and outputs a decreased Faradaic current when hybridized to a perfectly matched (PM) target, but conversely reports an increased Faradaic current when hybridized to a single-base mismatched (SM) target. Third, we describe the microfluidic electrochemical dynamic allele specific hybridization (microE-DASH) platform for versatile and rapid detection of single-nucleotide polymorphisms. Implementing electrochemical-based melting curve analysis within the microfluidic device, this platform directly detects PCR amplicon-like targets and distinguishes perfectly matched target from single-base mismatched target and heterozygote combination of both targets in 20 minutes. Finally, we present the microfluidic electrochemical quantitative loop-mediated isothermal amplification (MEQ-LAMP) platform for rapid, sensitive, and quantitative detection of pathogen genomic DNA at the point of care. DNA amplification is electrochemically monitored in real time within a monolithic microfluidic device, enabling the detection of as few as 16 copies of Salmonella genomic DNA via a single-step process in under an hour.
Self-monitoring of glucose is important for managing diabetes. Noninvasive glucose monitors are not yet available, but patients would benefit highly from such a device. We present results that may lead to a novel, point-of-care noninvasive system to measure blood glucose based on Raman spectroscopy. A hospitalized cohort of 111 subjects was measured using a custom-made Raman spectrometer system. Blood glucose reference samples were used to correlate Raman data to glucose levels, using advanced preprocessing and analysis algorithms. A correlation coefficient (R (2)) of .83 was found correlating independent Raman-based predictions on reference blood glucose for the full cohort. Stratification of the cohort in gender-specific groups raised correlation levels to .88 (females) and .94 (males). Glucose could be measured noninvasively with average errors as low as 0.9 mM. We conclude that this novel system shows promising results for the advance of noninvasive, point-of-care glucose monitoring. PMID:25037192
Scholtes-Timmerman, Maarten J; Bijlsma, Sabina; Fokkert, Marion J; Slingerland, Robbert; van Veen, Sjaak J F
This critical review evaluates progress toward viable point-of-care protein biomarker measurements for cancer detection and diagnostics. The ability to measure panels of specific, selective cancer biomarker proteins in physicians’ surgeries and clinics has the potential to revolutionize cancer detection, monitoring, and therapy. The dream envisions reliable, cheap, automated, technically undemanding devices that can analyze a patient’s serum or saliva in a clinical setting, allowing on-the-spot diagnosis. Existing commercial products for protein assays are reliable in laboratory settings, but have limitations for point-of-care applications. A number of ultrasensitive immunosensors and some arrays have been developed, many based on nanotechnology. Multilabel detection coupled with high capture molecule density in immunosensors and arrays seems to be capable of detecting a wide range of protein concentrations with sensitivity ranging into the sub pg mL?1 level. Multilabel arrays can be designed to detect both high and ultralow abundance proteins in the same sample. However, only a few of the newer ultrasensitive methods have been evaluated with real patient samples, which is key to establishing clinical sensitivity and selectivity. PMID:20614087
Kumar, Challa V.; Gutkind, J. Silvio; Patel, Vyomesh
Objective To pilot a provincial joint replacement registry using electronic point-of-care data collection. Design Data collection study. Setting Southwestern Ontario, which has a population base of 3.5 million people. Participants Eighteen orthopedic surgeons. Method Information on total hip and knee replacements was obtained by the orthopedic surgeons over a 6-month period. Information was obtained in paper form and electronically on hand-held computers. Main outcome measures Patient demographics, waiting times from referral to operation, patient satisfaction and relevance and value of electronic records compared with paper records. Main results Data were collected on 815 total hip and knee arthroplasties. A slightly greater number of hips required revision than knees. The majority of patients were in the 60 to 90-year age range. With respect to the waiting time from referral to operation 10% of patients waited less than 5 weeks, 50% waited less than 30 weeks, and 90% waited less than 59 weeks. There was a high level of patient satisfaction with the operation and with hospital care received. Most surgeons found that the gathering and use of data electronically was relevant and easy. The electronic data were more timely, accurate and complete than paper records. Conclusion Electronic point-of-care data collection is appropriate, particularly in high-volume, high-cost surgical interventions such as total joint replacements. PMID:11407830
Bourne, Robert B.; Sibbald, William J.; Doig, Gordon; Lee, Lydia; Adolph, Susan; Robertson, Debbie; Provencher, Maureen
We present a small, compact and portable device for point-of-care instantaneous early detection of anemia. The method used is based on direct hematocrit measurement from whole blood samples by means of impedance analysis. This device consists of a custom electronic instrumentation and a plug-and-play disposable sensor. The designed electronics rely on straightforward standards for low power consumption, resulting in a robust and low consumption device making it completely mobile with a long battery life. Another approach could be powering the system based on other solutions like indoor solar cells, or applying energy-harvesting solutions in order to remove the batteries. The sensing system is based on a disposable low-cost label-free three gold electrode commercial sensor for 50 µL blood samples. The device capability for anemia detection has been validated through 24 blood samples, obtained from four hospitalized patients at Hospital Clínic. As a result, the response, effectiveness and robustness of the portable point-of-care device to detect anemia has been proved with an accuracy error of 2.83% and a mean coefficient of variation of 2.57% without any particular case above 5%. PMID:25690552
Punter-Villagrasa, Jaime; Cid, Joan; Páez-Avilés, Cristina; Rodríguez-Villarreal, Ivón; Juanola-Feliu, Esteve; Colomer-Farrarons, Jordi; Miribel-Català, Pere Ll
Randomized controlled trials have traditionally been the gold standard against which all other sources of clinical evidence are measured. However, the cost of conducting these trials can be prohibitive. In addition, evidence from the trials frequently rests on narrow patient-inclusion criteria and thus may not generalize well to real clinical situations. Given the increasing availability of comprehensive clinical data in electronic health records (EHRs), some health system leaders are now advocating for a shift away from traditional trials and toward large-scale retrospective studies, which can use practice-based evidence that is generated as a by-product of clinical processes. Other thought leaders in clinical research suggest that EHRs should be used to lower the cost of trials by integrating point-of-care randomization and data capture into clinical processes. We believe that a successful learning health care system will require both approaches, and we suggest a model that resolves this escalating tension: a "green button" function within EHRs to help clinicians leverage aggregate patient data for decision making at the point of care. Giving clinicians such a tool would support patient care decisions in the absence of gold-standard evidence and would help prioritize clinical questions for which EHR-enabled randomization should be carried out. The privacy rule in the Health Insurance Portability and Accountability Act (HIPAA) of 1996 may require revision to support this novel use of patient data. PMID:25006150
Longhurst, Christopher A; Harrington, Robert A; Shah, Nigam H
Microfluidics have become an enabling technology for point-of-care and personalized diagnostics. Desirable capabilities of microfluidics-based diagnostic devices include simplicity, portability, low cost and the performance of multiplexed and quantitative measurements, ideally in a high-throughput format. Here we present the multiplexed volumetric bar-chart chip (V-Chip), which integrates all these capabilities in one device. A key feature of the V-Chip is that quantitative results are displayed as bar charts directly on the device—without the need for optical instruments or any data processing or plotting steps. This is achieved by directly linking oxygen production by catalase, which is proportional to the concentration of the analyte, with the displacement of ink along channels on the device. We demonstrate the rapid quantification of protein biomarkers in diverse clinical samples with the V-Chip. The development of the V-Chip thus opens up the possibility of greatly simplified point-of-care and personalized diagnostics. PMID:23250413
Song, Yujun; Zhang, Yuanqing; Bernard, Paul E.; Reuben, James M.; Ueno, Naoto T.; Arlinghaus, Ralph B.; Zu, Youli; Qin, Lidong
Immunoassays have been widely used in commercial, scientific and medical research for detection and quantification of analytes in complex mixtures. There is however a need for a point-of-care, multiplex diagnostic assays capable of providing rapid and quantitative measurements of analytes present in samples that are sufficiently simple to carry out without use of a laboratory or individuals trained in chemical analysis. We are developing a fluorescent lateral flow immunoassay platform to perform simultaneous, multiplexed detection of analytes in a complex fluid mixture along with instrumentation to optically quantitate the analytes in the sample. Our prototype imaging system is based on conventional 16-bit CCD optics, which enables the development of a rugged diagnostic instrument that can be further scaled down for point-of-care applications. We have compared protein microarrays with lateral flow assays (LFAs) to determine the sensitivity of each system for the measurement of distinct proteins in complex samples. We are pursuing the LFA platform such that it can easily be scaled to meet the requirements of any given screening application, and be implemented for use in a medical or surgical setting.
Rao, R. S.; Albala, J. S.; Lane, S. L.; Matthews, D. L.; Fisher, A. M.; Lambert, J. L.; Coleman, M. A.
Food-borne pathogens such as Listeria monocytogenes have been recognized as a major cause of human infections worldwide, leading to substantial health problems. Food-borne pathogen identification needs to be simpler, cheaper and more reliable than the current traditional methods. Here, we have constructed a low-cost paper biosensor for the detection of viable pathogenic bacteria with the naked eye. In this study, an effective isothermal amplification method was used to amplify the hlyA mRNA gene, a specific RNA marker in Listeria monocytogenes. The amplification products were applied to the paper biosensor to perform a visual test, in which endpoint detection was performed using sandwich hybridization assays. When the RNA products migrated along the paper biosensor by capillary action, the gold nanoparticles accumulated at the designated Test line and Control line. Under optimized experimental conditions, as little as 0.5 pg/?L genomic RNA from Listeria monocytogenes could be detected. The whole assay process, including RNA extraction, amplification, and visualization, can be completed within several hours. The developed method is suitable for point-of-care applications to detect food-borne pathogens, as it can effectively overcome the false-positive results caused by amplifying nonviable Listeria monocytogenes.
Liu, Hongxing; Xing, Da; Zhou, Xiaoming
Incorporation of point-of-care ultrasound into the skill set of Special Operations medical providers should come with an appreciation of the potential limitations of the technology. We present a case of a U.S. Army Special Forces Soldier who suffered traumatic monocular vision loss after being struck in the eye during a combatives tournament. Evaluation in the emergency department (ED) included an unremarkable ocular ultrasound, despite a high clinical suspicion of intraocular pathology. Ophthalmologic consultation was obtained emergently. Optical coherence topography and a dilated fundoscopic examination were performed, which revealed a small subretinal hemorrhage. We will review the history of ocular ultrasound and its sensitivity to detect intraocular pathology. We will also emphasize the need to obtain specialty consultation when the clinical suspicion for intraocular pathology is high despite a negative ocular ultrasound. PMID:23526323
Nydam, Timothy; Tanksley, Steve
Continuous, real-time remote monitoring through medical point - of - care (POC) systems appears to draw the interest of the scientific community for healthcare monitoring and diagnostic applications the last decades. Towards this direction a significant merit has been due to the advancements in several scientific fields. Portable, wearable and implantable apparatus may contribute to the betterment of today's healthcare system which suffers from fundamental hindrances. The number and heterogeneity of such devices and systems regarding both software and hardware components, i.e sensors, antennas, acquisition circuits, as well as the medical applications that are designed for, is impressive. Objective of the current study is to present the major technological advancements that are considered to be the driving forces in the design of such systems, to briefly state the new aspects they can deliver in healthcare and finally, the identification, categorization and a first level evaluation of them. PMID:25571429
Tsakalakis, Michail; Bourbakis, Nicolaos G
Computerized decision support for use at the point of care has to be comprehensive. It means that clinical information stored in electronic health records needs to be integrated with various forms of clinical knowledge (elicited from experts, discovered from data or summarized in systematic reviews of clinical trials). In order to provide such comprehensive support we created the MET-A3Support framework for constructing clinical applications aimed at various medical conditions. We employed the multiagent system paradigm and the O-MaSE methodology to define an engineering process involving three main activities: requirements engineering, analysis and design. Then we applied the process to build MET-A3Support. The paper describes the engineering process and its results, including models representing selected elements of our framework. PMID:18999068
Wilk, Szymon; Michalowski, Wojtek; O'Sullivan, Dympna; Farion, Ken; Matwin, Stan
For many drugs, finding the balance between efficacy and toxicity requires monitoring their concentrations in the patient's blood. Quantifying drug levels at the bedside or at home would have advantages in terms of therapeutic outcome and convenience, but current techniques require the setting of a diagnostic laboratory. We have developed semisynthetic bioluminescent sensors that permit precise measurements of drug concentrations in patient samples by spotting minimal volumes on paper and recording the signal using a simple point-and-shoot camera. Our sensors have a modular design consisting of a protein-based and a synthetic part and can be engineered to selectively recognize a wide range of drugs, including immunosuppressants, antiepileptics, anticancer agents and antiarrhythmics. This low-cost point-of-care method could make therapies safer, increase the convenience of doctors and patients and make therapeutic drug monitoring available in regions with poor infrastructure. PMID:24907901
Griss, Rudolf; Schena, Alberto; Reymond, Luc; Patiny, Luc; Werner, Dominique; Tinberg, Christine E; Baker, David; Johnsson, Kai
In medical facilities, there is strong motivation to develop detection systems that can provide continuous analysis of fluids in medical tubing used to either deliver or remove fluids from a patient's body. Possible applications include systems that increase the safety of intravenous (IV) drug injection and point-of-care health monitoring. In this work, we incorporated a surface-enhanced Raman scattering (SERS) sensor comprised of an array of closely spaced metal nanodomes into flexible tubing commonly used for IV drug delivery and urinary catheters. The nanodome sensor was fabricated by a low-cost, large-area process that enables single use disposable operation. As exemplary demonstrations, the sensor was used to kinetically detect promethazine (pain medication) and urea (urinary metabolite) within their clinically relevant concentration ranges. Distinct SERS peaks for each analyte were used to demonstrate separate detection and co-detection of the analytes. PMID:22159459
Choi, Charles J; Wu, Hsin-Yu; George, Sherine; Weyhenmeyer, Jonathan; Cunningham, Brian T
Although advanced fluid handling using elastomeric valves is useful for a variety of lab-on-a-chip procedures, their operation has traditionally relied on external laboratory infrastructure (such as gas tanks, computers, and ground electricity). This dependence has held back the use of elastomeric microvalves for point-of-care settings. Here, we demonstrate that microfabricated microvalves, via liquid-filled control channels, can be actuated using only a handheld instrument powered by a 9 V battery. This setup can achieve on-off fluid control with fast response times, coordinated switching of multiple valves, and operation of a biological assay. In the future, this technique may enable the widely used elastomeric microvalves (made by multilayer soft lithography) to be increasingly adopted for portable sensors and lab-on-a-chip systems. PMID:20383403
Addae-Mensah, Kweku A; Cheung, Yuk Kee; Fekete, Veronika; Rendely, Matthew S; Sia, Samuel K
Here, we present an integrated Lab-on-a-Chip (LOC) system based on silicon microring resonator devices. The system comprises of an electrical tracing-assisted silicon dual-microring sensor which requires a low-cost broadband light source instead of a bulky and expensive tunable laser therefore allows the development of cost-effective point-of-care (POC) diagnostic device. Highly efficient and fast nucleic acids detection with silicon microring device is demonstrated using an isothermal solid-phase amplification/detection (ISAD) technique. The integrated LOC system consists of dualmicroring sensors and microfluidic device for sample processing together with ISAD technique offers true realization of POC device for human disease diagnosis.
Park, Mi Kyoung; Liu, Qing; Kim, Kyung Woo; Shin, Yong; Kee, Jack Sheng; Song, Junfeng; Lo, Guo-Qiang; Kwong, Dim-Lee
This article reviews the current technology, literature, teaching models, and methods associated with simulation-based point-of-care ultrasound training. Patient simulation appears particularly well suited for learning point-of-care ultrasound, which is a required core competency for emergency medicine and other specialties. Work hour limitations have reduced the opportunities for clinical practice, and simulation enables practicing a skill multiple times before it may be used on patients. Ultrasound simulators can be categorized into 2 groups: low and high fidelity. Low-fidelity simulators are usually static simulators, meaning that they have nonchanging anatomic examples for sonographic practice. Advantages are that the model may be reused over time, and some simulators can be homemade. High-fidelity simulators are usually high-tech and frequently consist of many computer-generated cases of virtual sonographic anatomy that can be scanned with a mock probe. This type of equipment is produced commercially and is more expensive. High-fidelity simulators provide students with an active and safe learning environment and make a reproducible standardized assessment of many different ultrasound cases possible. The advantages and disadvantages of using low- versus high-fidelity simulators are reviewed. An additional concept used in simulation-based ultrasound training is blended learning. Blended learning may include face-to-face or online learning often in combination with a learning management system. Increasingly, with simulation and Web-based learning technologies, tools are now available to medical educators for the standardization of both ultrasound skills training and competency assessment. PMID:24371095
Lewiss, Resa E; Hoffmann, Beatrice; Beaulieu, Yanick; Phelan, Mary Beth
Everyday lifestyle related issues are the main cause of psychological stress, which contributes to health disparities experienced by individuals. Prolonged exposure to stress leads to the activation of signaling pathways from the brain that leads to release of cortisol from the adrenal cortex. Various biomarkers have been affected by psychological stress, but cortisol "a steroid hormone" is known as a potential biomarker for its estimation. Cortisol can also be used as a target analyte marker to determine the effect of exposure such as organophosphates on central nervous system, which alters the endocrine system, leading to imbalance in cortisol secretion. Cortisol secretion of individuals depends on day-night cycle and field environment hence its detection at point-of-care (POC) is deemed essential to provide personalized healthcare. Chromatographic techniques have been traditionally used to detect cortisol. The issues relating to assay formation, system complexity, and multistep extraction/purification limits its application in the field. In order to overcome these issues and to make portable and effective miniaturized platform, various immunoassays sensing strategies are being explored. However, electrochemical immunosensing of cortisol is considered as a recent advancement towards POC application. Highly sensitive, label-free and selective cortisol immunosensor based on microelectrodes are being integrated with the microfluidic system for automated diurnal cortisol monitoring useful for personalized healthcare. Although the reported sensing devices for cortisol detection may have a great scope to improve portability, electronic designing, performance of the integrated sensor, data safety and lifetime for point-of-care applications, This review is an attempt to describe the various cortisol sensing platforms and their potential to be integrated into a wearable system for online and continuous monitoring of cortisol rhythm at POC as a function of one's environment. PMID:24212052
Kaushik, Ajeet; Vasudev, Abhay; Arya, Sunil K; Pasha, Syed Khalid; Bhansali, Shekhar
Early diagnosis of tuberculosis (TB) facilitates appropriate treatment initiation and can limit the spread of this highly contagious disease. However, commonly used TB diagnostic methods are slow, often insensitive, cumbersome and inaccessible to most patients in TB endemic countries that lack necessary resources. This review discusses nucleic acid amplification technologies, which are being developed for rapid near patient TB diagnosis, that are in the market or undergoing clinical evaluation. They are based on PCR or isothermal methods and are implemented as manual assays or partially/fully integrated instrument systems, with associated tradeoffs between clinical performance, cost, robustness, quality assurance and usability in remote settings by minimally trained personnel. Unmet needs prevail for the identification of drug-resistant TB and for TB diagnosis in HIV-positive and pediatric patients. PMID:23153237
Niemz, Angelika; Boyle, David S
It represents a viable solution for the realization of a portable biosensor platform that could screen/diagnose acute myocardial infarction by measuring cardiac marker concentrations such as cardiac troponin I (cTnI), creatine kinase MB (CK-MB), and myoglobin (MYO) for application to u-health monitoring system. The portable biosensor platform introduced in this presentation has a more compact structure and a much higher measuring resolution than a conventional spectrometer system. Portable guided-mode resonance (GMR) biosensor platform was composed of a biosensor chip stage, an optical pick-up module, and a data display panel. Disposable plastic GMR biosensor chips with nano-grating patterns were fabricated by injection-molding. Whole blood filtration and label-free immunoassay were performed on these single chips, automatically. Optical pick-up module was fabricated by using the miniaturized bulk optics and the interconnecting optical fibers and a tunable VCSEL (vertical cavity surface emitting laser). The reflectance spectrum from the GMR biosensor was measured by the optical pick-up module. Cardiac markers in human serum with concentrations less than 0.1ng/mL were analyzed using a GMR biosensor. Analysis time was 30min, which is short enough to meet clinical requirements. Our results show that the GMR biosensor will be very useful in developing lowcost portable biosensors that can screen for cardiac diseases.
Sung, Gun Yong; Kim, Wan-Joong; Ko, Hyunsung; Kim, Bong K.; Kim, Kyung-Hyun; Huh, Chul; Hong, Jongcheol
Cardiovascular disease (CVD) is the single greatest cause of adult mortality in the western world and, consequently, places a massive burden on healthcare services and the economy. Lifestyles, lack of clearly defined risk assessment criteria, consistently high incidences of misdiagnosis and inappropriate referrals, all contribute significantly to this problem. It also correlates directly with inefficient or non-accessible early detection systems.
Barry McDonnell; Stephen Hearty; Paul Leonard; Richard O'Kennedy
Monitoring for drug-induced liver injury (DILI) via serial transaminase measurements in patients on potentially hepatotoxic medications (e.g., for HIV and tuberculosis) is routine in resource-rich nations, but often ...
Pollock, Nira R.
An optical biosensor system using surface-plasmon field-enhanced fluorescence has been developed, which allows high sensitivity and fast measurement available. Intensity of fluorophores in SPFS is highly dependent upon the distance from metal surface. The resonant evanescent electric field excites fluorophores within the penetration area. On the other hand, fluorescence quenching in close proximity to a metal surface interfere with the excitation. We have developed a new technology for fluorescent nanoparticles that could receive the energy from metal surface effectively. This enables technology of detecting strong and stable SPFS signals, as well as homogeneous assay method that allows us to eliminate binding/free separation process for unreacted fluorescent particles. A rate assay method has also been employed, which resolves affect from diffusion-limited access, in order to realize a fast surface immunoreaction in a microchannel. Taking advantage of these two developments, as eliminating an enzyme response process such as CLEIA, our system reaches much faster reaction time of 2 minutes to detect thyroid stimulating hormone (TSH) of canine serum sample at 0.1ng/mL. We believe our system with these new technologies is a powerful tool for in-vitro diagnosis which meets various clinical requirements.
Horii, Kazuyoshi; Kimura, Toshihito; Ohtsuka, Hisashi; Kasagi, Noriyuki; Oohara, Tomoya; Matsuno, Tadahiro; Hakamata, Masashi; Komatsu, Akihiro; Sendai, Tomonari
A non-invasive test for oro-ileal transit time (OITT) evaluation was developed, based on the measurement of tauroursodeoxycholic acid (TUDCA) oral fluid concentration profile after its oral administration. Exploiting the fact that TUDCA is actively absorbed only in the ileum, OITT is measured as the time corresponding to TUDCA maximum oral fluid concentration (tmax). To measure oral fluid TUDCA concentration in a point-of-care setting, an ultrasensitive portable immunosensor was developed, based on a competitive chemiluminescent enzyme immunoassay (CL-EIA), using immobilized anti-TUDCA antibody and an ursodeoxycholic acid (UDCA)-peroxidase conjugate as tracer, detected by enhanced chemiluminescence employing a portable charge-coupled device (CCD)-based device. The test was validated in 24 healthy subjects before and after treatment with Loperamide, a drug that increases OITT. The developed CL-EIA was accurate and precise, with a LLOQ of 50 pmol L(-1). The measured OITT for healthy subjects (291 ± 50 min) was fairly well correlated with OITT values obtained by measuring TUDCA in serum (r=0.89). An increased OITT was observed in all the studied subjects after Loperamide treatment. The CL immunosensor can be employed directly in gastroenterology and paediatric units and it can thus represent a new non-invasive simple test for OITT evaluation in a point-of-care setting, with improved diagnostic utility. PMID:23587552
Simoni, Patrizia; Magliulo, Maria; Mirasoli, Mara; Vestito, Amanda; Festi, Davide; Roda, Giulia; Colecchia, Antonio; Roda, Aldo
Objective Though absolute CD4+ T cell enumeration is the primary gateway to antiretroviral therapy initiation for HIV-positive patients in all developing countries, patient access to this critical diagnostic test is relatively poor. We technically evaluated the performance of a newly developed point-of-care CD4+ T cell technology, the MyT4, compared with conventional CD4+ T cell testing technologies. Design Over 250 HIV-positive patients were consecutively enrolled and their blood tested on the MyT4, BD FACSCalibur, and BD FACSCount. Results Compared with the BD FACSCount, the MyT4 had an r2 of 0.7269 and a mean bias of ?23.37 cells/µl. Compared with the BD FACSCalibur, the MyT4 had an r2 of 0.5825 and a mean bias of ?46.58 cells/µl. Kenya currently uses a CD4+ T cell test threshold of 350 cells/µl to determine patient eligibility for antiretroviral therapy. At this threshold, the MyT4 had a sensitivity of 95.3% (95% CI: 88.4–98.7%) and a specificity of 87.9% (95% CI: 82.3–92.3%) compared with the BD FACSCount and sensitivity and specificity of 88.2% (95% CI: 79.4–94.2%) and 84.2% (95% CI: 78.2–89.2%), respectively, compared with the BD FACSCalibur. Finally, the MyT4 had a coefficient of variation of 12.80% compared with 14.03% for the BD FACSCalibur. Conclusions We conclude that the MyT4 performed well at the current 350 cells/µl ART initiation eligibility threshold when used by lower cadres of health care facility staff in rural clinics compared to conventional CD4+ T cell technologies. PMID:25229408
Mwau, Matilu; Kadima, Silvia; Mwende, Joy; Adhiambo, Maureen; Akinyi, Catherine; Prescott, Marta; Lusike, Judi; Hungu, Jackson; Vojnov, Lara
Infectious diseases are the leading cause of death worldwide. Among them, tuberculosis (TB) remains a major threat to public health, exacerbated by the emergence of multiple drug-resistant (MDR) and extensively drug-resistant (XDR) Mycobacterium tuberculosis (Mtb). MDR-Mtb strains are resistant to first-line anti-TB drugs such as isoniazid and rifampicin; whereas XDR-Mtb strains are resistant to additional drugs including at least to any fluoroquinolone and one of the second-line anti-TB injectable drugs such as kanamycin, capreomycin, or amikacin. Clinically, these strains have significantly impacted the management of TB in high-incidence developing countries, where systemic surveillance of TB drug resistance is lacking. For effective management of TB on-site, early detection of drug resistance is critical to initiate treatment, to reduce mortality, and to thwart drug-resistant TB transmission. In this review, we discuss the diagnostic challenges to detect drug-resistant TB at the point-of-care (POC). Moreover, we present the latest advances in nano/microscale technologies that can potentially detect TB drug resistance to improve on-site patient care. PMID:24882226
Mani, Vigneshwaran; Wang, ShuQi; Inci, Fatih; De Libero, Gennaro; Singhal, Amit; Demirci, Utkan
Rapid and precise patterning of functional biomaterials is desirable for point-of-care (POC) tissue engineering and diagnostics. However, existing technologies such as dip-pen nanolithography and inkjet printing are currently unsuitable for POC applications due to issues of cost and portability. Here, we report the development of `BioPen', a portable tool for continuous, defined and scalable deposition of functional materials with micrometer spatial resolution and nanolitre volumetric resolution. BioPen is based upon the ballpoint pen but with multiple ``ink sources'' (functional material solutions) and with an apparatus that can be optimized for writing living cells, proteins, nucleic acids, etc. We demonstrate POC detection of human immunodeficiency virus type 1 (HIV-1) nucleic acid by writing on paper with BioPen using ``ink'' consisting of nucleic acid probes and nucleic acid-modified gold nanoparticles. We also demonstrate POC tissue engineering by writing a continuous pattern of living, functional, interconnected cells with a defined extracellular environment. Because it is simple, accurate, inexpensive and portable, BioPen has broad potential for POC detection of diagnostic biomarkers, and for POC engineering of tissues for a range of healing applications.
Han, Yu Long; Hu, Jie; Genin, Guy M.; Lu, Tian Jian; Xu, Feng
Rapid and precise patterning of functional biomaterials is desirable for point-of-care (POC) tissue engineering and diagnostics. However, existing technologies such as dip-pen nanolithography and inkjet printing are currently unsuitable for POC applications due to issues of cost and portability. Here, we report the development of 'BioPen', a portable tool for continuous, defined and scalable deposition of functional materials with micrometer spatial resolution and nanolitre volumetric resolution. BioPen is based upon the ballpoint pen but with multiple "ink sources" (functional material solutions) and with an apparatus that can be optimized for writing living cells, proteins, nucleic acids, etc. We demonstrate POC detection of human immunodeficiency virus type 1 (HIV-1) nucleic acid by writing on paper with BioPen using "ink" consisting of nucleic acid probes and nucleic acid-modified gold nanoparticles. We also demonstrate POC tissue engineering by writing a continuous pattern of living, functional, interconnected cells with a defined extracellular environment. Because it is simple, accurate, inexpensive and portable, BioPen has broad potential for POC detection of diagnostic biomarkers, and for POC engineering of tissues for a range of healing applications. PMID:24799039
Han, Yu Long; Hu, Jie; Genin, Guy M; Lu, Tian Jian; Xu, Feng
Fluorescence microscopy has long been a standard tool in laboratory medicine. Implementation of fluorescence microscopy for near-patient diagnostics, however, has been limited due to cost and complexity associated with traditional fluorescence microscopy techniques. There is a particular need for robust, low-cost imaging in high disease burden areas in the developing world, where access to central laboratory facilities and trained staff is limited. Here we describe a point-of-care assay that combines a disposable plastic cartridge with an extremely low cost fluorescence imaging instrument. Based on a novel, multi-mode planar waveguide configuration, the system capitalizes on advances in volume-manufactured consumer electronic components to deliver an imaging system with minimal moving parts and low power requirements. A two-color cell imager is presented, with magnification optimized for enumeration of immunostained human T cells. To demonstrate the system, peripheral blood mononuclear cells were stained with fluorescently labeled anti-human-CD4 and anti-human-CD3 antibodies. Registered images were used to generate fractional CD4+ and CD3+ staining and enumeration results that show excellent correlation with flow cytometry. The cell imager is under development as a very low cost CD4+ T cell counter for HIV disease management in limited resource settings.
Lochhead, Michael J.; Ives, Jeff; Givens, Monique; Delaney, Marie; Moll, Kevin; Myatt, Christopher J.
In the 90s, efforts arise in the scientific world to automate and integrate one or several laboratory applications in tinny devices by using microfluidic principles and fabrication technologies used mainly in the microelectronics field. It showed to be a valid method to obtain better reactions efficiency, shorter analysis times, and lower reagents consumption over existing analytical techniques. Traditionally, these fluidic microsystems able to realize laboratory essays are known as Lab-On-a-Chip (LOC) devices. The capability to transport cells, bacteria or biomolecules in an aqueous medium has significant potential for these microdevices, also known as micro-Total-Analysis Systems (uTAS) when their application is of analytical nature. In particular, the technique of dielectrophoresis (DEP) opened the possibility to manipulate, actuate or transport such biological particles being of great potential in medical diagnostics, environmental control or food processing. This technique consists on applying amplitude and frequency controlled AC signal to a given microsystem in order to manipulate or sort cells. Furthermore, the combination of this technique with electrical impedance measurements, at a single or multiple frequencies, is of great importance to achieve novel reliable diagnostic devices. This is because the sorting and manipulating mechanism can be easily combined with a fully characterizing method able to discriminate cells. The paper is focused in the electronics design of the quadrature DEP generator and the four-electrode impedance measurement modules. These together with the lab-on-a-chip device define a full conception of an envisaged Point-of-Care (POC) device.
del Moral Zamora, B.; Colomer-Farrarons, J.; Mir-Llorente, M.; Homs-Corbera, A.; Miribel-Català, P.; Samitier-Martí, J.
Antibodies are ubiquitously deployed on in vitro diagnostic (IVD) platforms for detecting a panoply of analytes indicative of environmental and food contamination, residue adulteration and both veterinary and medical diagnostics. In the clinical realm, rapid and accurate determination of disease status is paramount. The significance of immunodiagnostic performance cannot be overemphasized and in many cases reliable diagnosis informs medical intervention which can mean the difference between patient recovery and demise. Cardiovascular disease (CVD) is the single biggest cause of adult mortality in the western world and principal burden on the healthcare services. Although the troponin (Tn) family, in particular troponin I (TnI), are regarded as the gold standard for diagnosis of myocardial damage, over the last decade much research has focused on the identification of alternative cardiac biomarker molecules that can either supplant or complement TnI metrics to add value to cardiac risk stratification criteria. In particular, markers that appear earlier than TnI in the pathophyisiology of cardiac disease are highly sought after. The subject of this addendum represents part of a broader challenge to deliver novel rapid point-of-care (POC) diagnostics to provide a chip-based multi-plexed platform for more comprehensive profiling of cardiac status with additive diagnostic and prognostic value. Specifically, it outlines proof-of-concept direct myeloperoxidase (MPO) detection, demonstrates the benefits of using recombinant antibodies in POC diagnostics and describes optimized strategies for generation of superior candidate antibody panels. PMID:21637010
Hearty, Stephen; O'Kennedy, Richard
We present a cost-effective portable ultrasound system based on a single field-programmable gate array (FPGA) for point-of-care applications. In the portable ultrasound system developed, all the ultrasound signal and image processing modules, including an effective 32-channel receive beamformer with pseudo-dynamic focusing, are embedded in an FPGA chip. For overall system control, a mobile processor running Linux at 667 MHz is used. The scan-converted ultrasound image data from the FPGA are directly transferred to the system controller via external direct memory access without a video processing unit. The potable ultrasound system developed can provide real-time B-mode imaging with a maximum frame rate of 30, and it has a battery life of approximately 1.5 h. These results indicate that the single FPGA-based portable ultrasound system developed is able to meet the processing requirements in medical ultrasound imaging while providing improved flexibility for adapting to emerging POC applications. PMID:22828834
Kim, Gi-Duck; Yoon, Changhan; Kye, Sang-Bum; Lee, Youngbae; Kang, Jeeun; Yoo, Yangmo; Song, Tai-kyong
A novel handheld optical sensor for quantification of fluorescent microarrays, the so-called portMD-113 has been developed. On the surface of a planar waveguide, the spots of different fluorescently labeled biological complexes are excited by the evanescent field of the guided light. The emitted fluorescence signals of the spots are independently and simultaneously detected applying our system, which consists of a pinehole array, a microlens array, an interference filter and a detector array. As it is demonstrated in comparative measurements, the detection limit of this sensor is close to that of commercial top microarray readers, e.g. of modern laser scanners, while it has remarkable and important advantages over them. Namely, the device comprises only a few low-cost, lightweight and small components without applying any moving or energy-intensive elements, which results in turn in a commercially competitive, handheld and compact design and in the possibility to be supplied simply by a battery or a personal computer. These advantageous properties open prospects e.g. for point-of-care medical checks, as well. PMID:23612063
Kozma, P; Lehmann, A; Wunderlich, K; Michel, D; Schumacher, S; Ehrentreich-Förster, E; Bier, F F
Variation of probe immobilization on microarrays hinders the ability to make high quality, assertive and statistically relevant conclusions needed in the healthcare setting. To address this problem, we have developed a calibrated, compact, inexpensive, multiplexed, dual modality point-of-care detection platform that calibrates and correlates surface probe density measured label-free to captured labeled secondary antibody, is independent of chip-to-chip variability, and improves upon existing diagnostic technology. We have identified four major technological advantages of our proposed platform: the capability to perform single spot analysis based on the fluorophore used for detection, a 10-fold gain in fluorescence signal due to optimized substrate, a calibrated, quantitative method that uses the combined fluorescent and label-free modalities to accurately measure the density of probe and bound target for a variety of systems, and a compact measurement platform offering reliable and rapid results at the doctor’s office. Already, we have formulated over a 90% linear correlation between the amount of probe bound to surface and the resulting fluorescence of captured target for IgG, ?-lactoglobulin, Ara h 1 peanut allergen, and Phl 5a Timothy grass allergen. PMID:22254352
Monroe, M. R.; Reddington, A. P.; Cretich, M.; Chiari, M.; Little, F.; Ünlü, M. S.
With the growing number of aging population and a significant portion of that suffering from cardiac diseases, it is conceivable that remote ECG patient monitoring systems are expected to be widely used as Point-of-Care (PoC) applications in hospitals around the world. Therefore, huge amount of ECG signal collected by Body Sensor Networks (BSNs) from remote patients at homes will be transmitted along with other physiological readings such as blood pressure, temperature, glucose level etc. and diagnosed by those remote patient monitoring systems. It is utterly important that patient confidentiality is protected while data is being transmitted over the public network as well as when they are stored in hospital servers used by remote monitoring systems. In this paper, a wavelet based steganography technique has been introduced which combines encryption and scrambling technique to protect patient confidential data. The proposed method allows ECG signal to hide its corresponding patient confidential data and other physiological information thus guaranteeing the integration between ECG and the rest. To evaluate the effectiveness of the proposed technique on the ECG signal, two distortion measurement metrics have been used: the Percentage Residual Difference (PRD) and the Wavelet Weighted PRD (WWPRD). It is found that the proposed technique provides high security protection for patients data with low (less than 1% ) distortion and ECG data remains diagnosable after watermarking (i.e. hiding patient confidential data) and as well as after watermarks (i.e. hidden data) are removed from the watermarked data. PMID:23708767
Ibaida, Ayman; Khalil, Ibrahim
There is a growing demand to integrate biosensors with microfluidics to provide miniaturized platforms with many favorable properties, such as reduced sample volume, decreased processing time, low cost analysis and low reagent consumption. These microfluidics-integrated biosensors would also have numerous advantages such as laminar flow, minimal handling of hazardous materials, multiple sample detection in parallel, portability and versatility in design. Microfluidics involves the science and technology of manipulation of fluids at the micro- to nano-liter level. It is predicted that combining biosensors with microfluidic chips will yield enhanced analytical capability, and widen the possibilities for applications in clinical diagnostics. The recent developments in microfluidics have helped researchers working in industries and educational institutes to adopt some of these platforms for point-of-care (POC) diagnostics. This review focuses on the latest advancements in the fields of microfluidic biosensing technologies, and on the challenges and possible solutions for translation of this technology for POC diagnostic applications. We also discuss the fabrication techniques required for developing microfluidic-integrated biosensors, recently reported biomarkers, and the prospects of POC diagnostics in the medical industry. PMID:24019250
Kumar, Suveen; Kumar, Saurabh; Ali, Md Azahar; Anand, Pinki; Agrawal, Ved Varun; John, Renu; Maji, Sagar; Malhotra, Bansi D
We present here research work on two optical biosensors which have been developed within two separate European projects (6th and 7th EU Framework Programmes). The biosensors are based on the idea of a disposable biochip, integrating photonics and microfluidics, optically interrogated by a multichannel interrogation platform. The objective is to develop versatile tools, suitable for performing screening tests at Point of Care or for example, at schools or in the field. The two projects explore different options in terms of optical design and different materials. While SABIO used Si3N4/SiO2 ring resonators structures, P3SENS aims at the use of photonic crystal devices based on polymers, potentially a much more economical option. We discuss both approaches to show how they enable high sensitivity and multiple channel detection. The medium term objective is to develop a new detection system that has low cost and is portable but at the same time offering high sensitivity, selectivity and multiparametric detection from a sample containing various components (e.g. blood, serum, saliva, etc.). Most biological sensing devices already present on the market suffer from limitations in multichannel operation capability (either the detection of multiple analytes indicating a given pathology or the simultaneous detection of multiple pathologies). In other words, the number of different analytes that can be detected on a single chip is very limited. This limitation is a main issue addressed by the two projects. The excessive cost per test of conventional bio sensing devices is a second issue that is addressed.
Giannone, Domenico; Kazmierczak, Andrzej; Dortu, Fabian; Vivien, Laurent; Sohlström, Hans
Local immobilization of quantum dots in a microchannel for the development of a point of care microdiscs, localised in a microchannel onto which streptavidin coated quantum dots (SA-QDs) will strongly attach. Preliminary results of such immobilizations in a microchannel are reported in this abstract. KEY
Background Neonatal infections annually claim lives of 1.4 million neonates worldwide. Until now, there is no ideal diagnostic test for detecting sepsis and thus management of possible sepsis cases often depends on clinical algorithm leading to empirical treatment. This often results in unnecessary antibiotic use, which may lead to emergence of antibiotic resistance. Biomarkers have shown great promise in diagnosis of sepsis and guiding appropriate treatment of neonates. In this study, we conducted a literature review of existing biomarkers to analyze their status for use as a point-of-care diagnostic in developing countries. Methods PubMed and EMBASE database were searched with keywords, ‘infections’, ‘neonates’, and ‘biomarkers’ to retrieve potentially relevant papers from the period 1980 to 2010. Leading hospitals and manufacturers were communicated to inquire about the cost, laboratory requirements and current standing of biomarkers in clinical use. Results The search returned 6407 papers on biomarkers; 65 were selected after applying inclusion and exclusion criteria. Among the studies, C-reactive protein (CRP), procalcitonin (PCT) and interleukin 6 (IL-6) were the most widely studied biomarkers and were considered to be most promising for diagnosing neonatal infections. About 90% of the studies were from developed countries; more than 50% were from Europe. Conclusions Extensive work is being performed to find the diagnostic and prognostic value of biomarkers. However, the methodologies and study design are highly variable. Despite numerous research papers on biomarkers, their use in clinical setting is limited to CRP. The methods for detection of biomarkers are far too advanced to be used at the community level where most of the babies are dying. It is important that a harmonized multi-site study is initiated to find a battery of biomarkers for diagnosis of neonatal infections. PMID:23198119
Meem, Mahbuba; Modak, Joyanta K.; Mortuza, Roman; Morshed, Mahboob; Islam, Mohammad Shahidul; Saha, Samir K.
Technology advances in rapid diagnosis and clinical monitoring of human immunodeficiency virus (HIV) infection have been made in recent years, greatly benefiting those at risk of HIV infection, those needing care and treatment, and those on antiretroviral (ART) therapy in sub-Saharan Africa. However, resource-limited, geographically remote, and harsh climate regions lack uniform access to these technologies. HIV rapid diagnostic tests (RDTs) and monitoring tools, such as those for CD4 counts, as well as tests for coinfections, are being developed and have great promise in these settings to aid in patient care. Here we explore the advances in point-of-care (POC) technology in the era where portable devices are bringing the laboratory to the patient. Quality management approaches will be imperative for the successful implementation of POC testing in endemic settings to improve patient care. PMID:22287974
Shott, Joseph P.; Galiwango, Ronald M.; Reynolds, Steven J.
Early detection of Mycobacterium tuberculosis complex (MTBC) and markers conveying drug resistance can have a beneficial impact on preventive public health actions. We describe here a new molecular point-of-care (POC) system, the Genedrive, which is based on simple sample preparation combined with PCR to detect MTBC and simultaneously detect mutation markers in the rpoB gene directly from raw sputum sample. Hybridization probes were used to detect the presence of the key mutations in codons 516, 526, and 531 of the rpoB gene. The sensitivities for MTBC and rpoB detection from sputum samples were assessed using model samples spiked with known numbers of bacteria prepared from liquid cultures of M. tuberculosis. The overall sensitivities were 90.8% (95% confidence interval [CI], 81, 96.5) for MTBC detection and 72.3% (95% CI, 59.8, 82.7) for rpoB detection. For samples containing ?1,000 CFU/ml, the sensitivities were 100% for MTBC and 85.7% for rpoB detection, while for samples containing ?100 CFU/ml, the sensitivities were 86.4% and 65.9% for MTBC and rpoB detection, respectively. The specificity was shown to be 100% (95% CI, 83.2, 100) for MTBC and rpoB. The clinical sputum samples were processed using the same protocol and showed good concordance with the data generated from the model. Tuberculosis-infected subjects with smear samples assessed as scanty or negative were detectable by the Genedrive system. In these paucibacillary patients, the performance of the Genedrive system was comparable to that of the GeneXpert assay. The characteristics of the Genedrive platform make it particularly useful for detecting MTBC and rifampin resistance in low-resource settings and for reducing the burden of tuberculosis disease. PMID:24478480
Castan, Pablo; de Pablo, Alicia; Fernández-Romero, Natalia; Rubio, José Miguel; Cobb, Benjamin D.; Mingorance, Jesús
A simple, sensitive optical analyzer for the rapid determination of cyanide in blood in point of care applications is described. HCN is liberated by the addition of 20% H3PO4 and is absorbed by a paper filter impregnated with borate-buffered (pH 9.0) hydroxoaquocobinamide Hereinafter called cobinamide). Cobinamide on the filter changes color from orange (?max = 510 nm) to violet (?max = 583 nm) upon reaction with cyanide. This color change is monitored in the transmission mode by a light emitting diode (LED) with a 583 nm emission maximum and a photodiode detector. The observed rate of color change increases 10x when the cobinamide solution for filter impregnation is prepared in borate-buffer rather than in water. The use of a second LED emitting at 653 nm and alternate pulsing of the LEDs improve the limit of detection by 4x to ~ 0.5 ?M for a 1 mL blood sample. Blood cyanide levels of imminent concern (? 10 ?M) can be accurately measured in ~ 2 min. The response is proportional to the mass of cyanide in the sample – smaller sample volumes can be successfully used with proportionate change in the concentration LODs. Bubbling air through the blood-acid mixture was found effective for mixing of the acid with the sample and the liberation of HCN. A small amount of ethanol added to the top of the blood was found to be the most effective means to prevent frothing during aeration. The relative standard deviation (RSD) for repetitive determination of blood samples containing 9 ?M CN was 1.09% (n=5). The technique was compared blind with a standard microdiffusion-spectrophotometric method used for the determination of cyanide in rabbit blood. The results showed good correlation (slope 1.05, r2 0.9257); independent calibration standards were used. PMID:21553921
Ma, Jian; Ohira, Shin-Ichi; Mishra, Santosh K.; Puanngam, Mahitti; Dasgupta, Purnendu K.; Mahon, Sari B.; Brenner, Matthew; Blackledge, William; Boss, Gerry R.
Background Point-of-care ultrasound performed by clinicians is a useful supplement in the treatment and assessment of patients. We aimed to investigate whether medical students with minimal training were able to successfully acquire and interpret ultrasound images using a pocket-size imaging device (PSID) as a supplement to their clinical practice. Methods Thirty 5th year (of six) medical students volunteered to participate. They were each given a personal PSID device to use as a supplement to their physical examination during their allocated hospital terms. Prior to clinical placement the students were given three evenings of hands-on training with PSID by a board certified radiologist/cardiologist, including three short lectures (<20 min). The students were shown basic ultrasound techniques and taught to assess for basic, clinically relevant pathology. They were specifically instructed to assess for the presence or absence of reduced left ventricular function (assessed as mitral annular excursion?10 mm), pericardial effusion, pleural effusion, lung comets, hydronephrosis, bladder distension, gallstones, abdominal free-fluid, cholecystitis, and estimate the diameter of abdominal aorta and inferior vena cava. Results A total of 211 patients were examined creating 1151 ultrasound recordings. Acceptable organ presentation was 73.8% (95% CI 63.1-82.6) for cardiovascular and 88.4% (95% CI: 80.6-93.6) for radiological structures. Diagnostic accuracy was 93.5% (95% CI: 89.0-96.2) and 93.2% (95% CI: 87.4-96.5) respectively. Conclusion Medical students with minimal training were able to use PSID as a supplement to standard physical examination and successfully acquire acceptable relevant organ recordings for presentation and correctly interpret these with great accuracy. PMID:25070529
Introduction New medical technology brings the potential of lawsuits related to the usage of that new technology. In recent years the use of point-of-care (POC) ultrasound has increased rapidly in the emergency department (ED). POC ultrasound creates potential legal risk to an emergency physician (EP) either using or not using this tool. The aim of this study was to quantify and characterize reported decisions in lawsuits related to EPs performing POC ultrasound. Methods We conducted a retrospective review of all United States reported state and federal cases in the Westlaw database. We assessed the full text of reported cases between January 2008 and December 2012. EPs with emergency ultrasound fellowship training reviewed the full text of each case. Cases were included if an EP was named, the patient encounter was in the emergency department, the interpretation or failure to perform an ultrasound was a central issue and the application was within the American College of Emergency Physician (ACEP) ultrasound core applications. In order to assess deferred risk, cases that involved ultrasound examinations that could have been performed by an EP but were deferred to radiology were included. Results We identified five cases. All reported decisions alleged a failure to perform an ultrasound study or a failure to perform it in a timely manner. All studies were within the scope of emergency medicine and were ACEP emergency ultrasound core applications. A majority of cases (n=4) resulted in a patient death. There were no reported cases of failure to interpret or misdiagnoses. Conclusion In a five-year period from January 2008 through December 2012, five malpractice cases involving EPs and ultrasound examinations that are ACEP core emergency ultrasound applications were documented in the Westlaw database. All cases were related to failure to perform an ultrasound study or failure to perform a study in a timely manner and none involved failure to interpret or misdiagnosis when using of POC ultrasound.
Stolz, Lori; O’Brien, Kathleen M.; Miller, Marc L.; Winters-Brown, Nicole D.; Blaivas, Michael; Adhikari, Srikar
AIMS Relevant and easily accessible drug information at point-of-care is essential for physicians' decision making when prescribing. However, the information available by using Clinical Decision Support Systems (CDSSs) often does not meet physicians' requirements. The Summary of Product Characteristics (SmPC) is statutory information about drugs. However, the current structure, content and format of SmPCs make it difficult to incorporate them into CDSSs and link them to relevant patient information from the Electronic Health Records. The aim of the study was to evaluate the perceived needs for drug information among physicians in Sweden. METHODS We recruited three focus group discussions with 18 physicians covering different specialities. The information from the groups was combined with a questionnaire administered at the beginning of the group discussions. RESULTS Physicians reported their needs for knowledge databases at the point of drug prescribing. This included more consistent information about existing and new drugs. They also wished to receive automatically generated alerts for severe drug–drug interactions and adverse effects, and to have functions for calculating glomerular filtration rate to enable appropriate dose adjustments to be made for elderly patients and those with impaired renal function. Additionally, features enhancing electronic communication with colleagues and making drug information more searchable were suggested. CONCLUSIONS The results from the current study showed the need for knowledge databases which provide consistent information about new and existing drugs. Most of the required information from physicians appeared to be possible to transfer from current SmPCs to CDSSs. However, inconsistencies in the SmPC information have to be reduced to enhance their utility. PMID:21714807
Rahmner, Pia Bastholm; Eiermann, Birgit; Korkmaz, Seher; Gustafsson, Lars L; Gruvén, Magnus; Maxwell, Simon; Eichle, Hans-Georg; Vég, Anikó
An Integrated Tiered Service Delivery Model (ITSDM) Based on Local CD4 Testing Demands Can Improve Turn-Around Times and Save Costs whilst Ensuring Accessible and Scalable CD4 Services across a National Programme
Background The South African National Health Laboratory Service (NHLS) responded to HIV treatment initiatives with two-tiered CD4 laboratory services in 2004. Increasing programmatic burden, as more patients access anti-retroviral therapy (ART), has demanded extending CD4 services to meet increasing clinical needs. The aim of this study was to review existing services and develop a service-model that integrated laboratory-based and point-of-care testing (POCT), to extend national coverage, improve local turn-around/(TAT) and contain programmatic costs. Methods NHLS Corporate Data Warehouse CD4 data, from 60–70 laboratories and 4756 referring health facilities was reviewed for referral laboratory workload, respective referring facility volumes and related TAT, from 2009–2012. Results An integrated tiered service delivery model (ITSDM) is proposed. Tier-1/POCT delivers CD4 testing at single health-clinics providing ART in hard-to-reach areas (<5 samples/day). Laboratory-based testing is extended with Tier-2/POC-Hubs (processing ?30–40 CD4 samples/day), consolidating POCT across 8–10 health-clinics with other HIV-related testing and Tier-3/‘community’ laboratories, serving ?40 health-clinics, processing ?150 samples/day. Existing Tier-4/‘regional’ laboratories serve ?100 facilities and process <350 samples/day; Tier-5 are high-volume ‘metro’/centralized laboratories (>350–1500 tests/day, serving ?200 health-clinics). Tier-6 provides national support for standardisation, harmonization and quality across the organization. Conclusion The ITSDM offers improved local TAT by extending CD4 services into rural/remote areas with new Tier-3 or Tier-2/POC-Hub services installed in existing community laboratories, most with developed infrastructure. The advantage of lower laboratory CD4 costs and use of existing infrastructure enables subsidization of delivery of more expensive POC services, into hard-to-reach districts without reasonable access to a local CD4 laboratory. Full ITSDM implementation across 5 service tiers (as opposed to widespread implementation of POC testing to extend service) can facilitate sustainable ‘full service coverage’ across South Africa, and save>than R125 million in HIV/AIDS programmatic costs. ITSDM hierarchical parental-support also assures laboratory/POC management, equipment maintenance, quality control and on-going training between tiers. PMID:25490718
Glencross, Deborah K.; Coetzee, Lindi M.; Cassim, Naseem
A novel innovative approach towards a marketable lab-on-chip system for point-of-care in vitro diagnostics is reported. In a consortium of seven Fraunhofer Institutes a lab-on-chip system called "Fraunhofer ivD-platform" has been established which opens up the possibility for an on-site analysis at low costs. The system features a high degree of modularity and integration. Modularity allows the adaption of common and established assay types of various formats. Integration lets the system move from the laboratory to the point-of-need. By making use of the microarray format the lab-on-chip system also addresses new trends in biomedicine. Research topics such as personalized medicine or companion diagnostics show that multiparameter analyses are an added value for diagnostics, therapy as well as therapy control. These goals are addressed with a low-cost and self-contained cartridge, since reagents, microfluidic actuators and various sensors are integrated within the cartridge. In combination with a fully automated instrumentation (read-out and processing unit) a diagnostic assay can be performed in about 15 min. Via a user-friendly interface the read-out unit itself performs the assay protocol, data acquisition and data analysis. So far, example assays for nucleic acids (detection of different pathogens) and protein markers (such as CRP and PSA) have been established using an electrochemical read-out based on redoxcycling or an optical read-out based on total internal reflectance fluorescence (TIRF). It could be shown that the assay performance within the cartridge is similar to that found for the same assay in a microtiter plate. Furthermore, recent developments are the integration of sample preparation and polymerase chain reaction (PCR) on-chip. Hence, the instrument is capable of providing heating-and-cooling cycles necessary for DNA-amplification. In addition to scientific aspects also the production of such a lab-on-chip system was part of the development since this heavily affects the success of a later market launch. In summary, the Fraunhofer ivD-platform covers the whole value chain ranging from microfluidics, material and polymer sciences, assay and sensor development to the production and assembly design. In this consortium the gap between diagnostic needs and available technologies can be closed. PMID:22038328
Schumacher, Soeren; Nestler, Jörg; Otto, Thomas; Wegener, Michael; Ehrentreich-Förster, Eva; Michel, Dirk; Wunderlich, Kai; Palzer, Silke; Sohn, Kai; Weber, Achim; Burgard, Matthias; Grzesiak, Andrzej; Teichert, Andreas; Brandenburg, Albrecht; Koger, Birgit; Albers, Jörg; Nebling, Eric; Bier, Frank F
Nucleotide and immunoassays are important tools for disease diagnostics. Many of the current laboratory-based analytical diagnostic techniques require multiple assay steps and long incubation times before results are acquired. In the development of bioassays designed for detecting the emergence and spread of diseases in point-of-care (POC) and remote settings, more rapid and portable analytical methods are necessary. Nanoparticles provide simple and reproducible synthetic methods for the preparation of substrates that can be applied in colloidal assays, providing gains in kinetics due to miniaturization and plasmonic substrates for surface enhanced spectroscopies. Specifically, surface enhanced Raman spectroscopy (SERS) is finding broad application as a signal transduction method in immunological and nucleotide assays due to the production of narrow spectral peaks from the scattering molecules and the potential for simultaneous multiple analyte detection. The application of SERS to a no-wash, magnetic capture assay for the detection of West Nile Virus Envelope and Rift Valley Fever Virus N antigens is described. The platform utilizes colloid based capture of the target antigen in solution, magnetic collection of the immunocomplexes and acquisition of SERS spectra by a handheld Raman spectrometer. The reagents for a core-shell nanoparticle, SERS based assay designed for the capture of target microRNA implicated in acute myocardial infarction are also characterized. Several new, small molecule Raman scatterers are introduced and used to analyze the enhancing properties of the synthesized gold coated-magnetic nanoparticles. Nucleotide and immunoassay platforms have shown improvements in speed and analyte capture through the miniaturization of the capture surface and particle-based capture systems can provide a route to further surface miniaturization. A reaction-diffusion model of the colloidal assay platform is presented to understand the interplay of system parameters such as particle diameter, initial analyte concentration and dissociation constants. The projected sensitivities over a broad range of assay conditions are examined and the governing regime of particle systems reported. The results provide metrics in the design of more robust analytics that are of particular interest for POC diagnostics.
Driscoll, Ashley J.
Functionalized magnetic nanoparticles are important components in biorecognition and medical diagnostics. Here, we present a review of our contribution to this interdisciplinary research field. We start by describing a simple one-step process for the synthesis of highly uniform ferrite nanoparticles (d = 20-200 nm) and their functionalization with amino acids via carboxyl groups. For real-world applications, we used admicellar polymerization to produce 200 nm diameter 'FG beads', consisting of several 40 nm diameter ferrite nanoparticles encapsulated in a co-polymer of styrene and glycidyl methacrylate for high throughput molecular screening. The highly dispersive FG beads were functionalized with an ethylene glycol diglycidyl ether spacer and used for affinity purification of methotrexate-an anti-cancer agent. We synthesized sub-100 nm diameter magnetic nanocapsules by exploiting the self-assembly of viral capsid protein pentamers, where single 8, 20, and 27 nm nanoparticles were encapsulated with VP1 pentamers for applications including MRI contrast agents. The FG beads are now commercially available for use in fully automated bio-screening systems. We also incorporated europium complexes inside a polymer matrix to produce 140 nm diameter fluorescent-ferrite beads (FF beads), which emit at 618 nm. These FF beads were used for immunofluorescent staining for diagnosis of cancer metastases to lymph nodes during cancer resection surgery by labeling tumor cell epidermal growth factor receptor (EGFRs), and for the detection of brain natriuretic peptide (BNP)-a hormone secreted in excess amounts by the heart when stressed-to a level of 2.0 pg ml(-1). We also describe our work on Hall biosensors made using InSb and GaAs/InGaAs/AlGaAs 2DEG heterostructures integrated with gold current strips to reduce measurement times. Our approach for the detection of sub-200 nm magnetic bead is also described: we exploit the magnetically induced capture of micrometer sized 'probe beads' by nanometer sized 'target beads', enabling the detection of small concentrations of beads as small as 8 nm in 'pumpless' microcapillary systems. Finally, we describe a 'label-less homogeneous' procedure referred to as 'magneto-optical transmission (MT) sensing', where the optical transmission of a solution containing rotating linear chains of magnetic nanobeads was used to detect biomolecules with pM-level sensitivity with a dynamic range of more than four orders of magnitude. Our research on the synthesis and applications of nanoparticles is particularly suitable for point of care diagnostics. PMID:20935358
Sandhu, Adarsh; Handa, Hiroshi; Abe, Masanori
Functionalized magnetic nanoparticles are important components in biorecognition and medical diagnostics. Here, we present a review of our contribution to this interdisciplinary research field. We start by describing a simple one-step process for the synthesis of highly uniform ferrite nanoparticles (d = 20-200 nm) and their functionalization with amino acids via carboxyl groups. For real-world applications, we used admicellar polymerization to produce 200 nm diameter 'FG beads', consisting of several 40 nm diameter ferrite nanoparticles encapsulated in a co-polymer of styrene and glycidyl methacrylate for high throughput molecular screening. The highly dispersive FG beads were functionalized with an ethylene glycol diglycidyl ether spacer and used for affinity purification of methotrexate—an anti-cancer agent. We synthesized sub-100 nm diameter magnetic nanocapsules by exploiting the self-assembly of viral capsid protein pentamers, where single 8, 20, and 27 nm nanoparticles were encapsulated with VP1 pentamers for applications including MRI contrast agents. The FG beads are now commercially available for use in fully automated bio-screening systems. We also incorporated europium complexes inside a polymer matrix to produce 140 nm diameter fluorescent-ferrite beads (FF beads), which emit at 618 nm. These FF beads were used for immunofluorescent staining for diagnosis of cancer metastases to lymph nodes during cancer resection surgery by labeling tumor cell epidermal growth factor receptor (EGFRs), and for the detection of brain natriuretic peptide (BNP)—a hormone secreted in excess amounts by the heart when stressed—to a level of 2.0 pg ml - 1. We also describe our work on Hall biosensors made using InSb and GaAs/InGaAs/AlGaAs 2DEG heterostructures integrated with gold current strips to reduce measurement times. Our approach for the detection of sub-200 nm magnetic bead is also described: we exploit the magnetically induced capture of micrometer sized 'probe beads' by nanometer sized 'target beads', enabling the detection of small concentrations of beads as small as 8 nm in 'pumpless' microcapillary systems. Finally, we describe a 'label-less homogeneous' procedure referred to as 'magneto-optical transmission (MT) sensing', where the optical transmission of a solution containing rotating linear chains of magnetic nanobeads was used to detect biomolecules with pM-level sensitivity with a dynamic range of more than four orders of magnitude. Our research on the synthesis and applications of nanoparticles is particularly suitable for point of care diagnostics.
Sandhu, Adarsh; Handa, Hiroshi; Abe, Masanori
In this paper the methodology of designing a genomic-based point-of-care diagnostic system composed of a microfluidic Lab-On-Chip, algorithms for microarray image information extraction and knowledge modeling of clinico-genomic patient data is presented. The data are processed by genome wide association studies for two complex diseases: rheumatoid arthritis and multiple sclerosis. Respecting current technological limitations of autonomous molecular-based Lab-On-Chip systems the approach proposed in this work aims to enhance the diagnostic accuracy of the miniaturized LOC system. By providing a decision support system based on the data mining technologies, a robust portable integrated point-of-care diagnostic assay will be implemented. Initially, the gene discovery process is described followed by the detection of the most informative SNPs associated with the diseases. The clinical data and the selected associated SNPs are modeled using data mining techniques to allow the knowledge modeling framework to provide the diagnosis for new patients performing the point-of-care examination. The microfluidic LOC device supplies the diagnostic component of the platform with a set of SNPs associated with the diseases and the ruled-based decision support system combines this genomic information with the clinical data of the patient to outcome the final diagnostic result. PMID:19964246
Kalatzis, Fanis G; Giannakeas, Nikolaos; Exarchos, Themis P; Lorenzelli, Leandro; Adami, Andrea; Decarli, Massimiliano; Lupoli, Sara; Macciardi, Fabio; Markoula, Sofia; Georgiou, Ioannis; Fotiadis, Dimitrios I
The recent revolution in digital technologies and information processing methods present important opportunities to transform the way optical imaging is performed, particularly toward improving the throughput of microscopes while at the same time reducing their relative cost and complexity. Lensfree computational microscopy is rapidly emerging toward this end, and by discarding lenses and other bulky optical components of conventional imaging systems, and relying on digital computation instead, it can achieve both reflection and transmission mode microscopy over a large field-of-view within compact, cost-effective and mechanically robust architectures. Such high throughput and miniaturized imaging devices can provide a complementary toolset for telemedicine applications and point-of-care diagnostics by facilitating complex and critical tasks such as cytometry and microscopic analysis of e.g., blood smears, Pap tests and tissue samples. In this article, the basics of these lensfree microscopy modalities will be reviewed, and their clinically relevant applications will be discussed. PMID:22433451
Isikman, Serhan O.; Greenbaum, Alon; Lee, Myungjun; Bishara, Waheb; Mudanyali, Onur; Su, Ting-Wei; Ozcan, Aydogan
This paper presents a taxonomy for medical devices that includes the review of over 260 companies. The taxonomy classifies medical device products with respect to their output interface. Each medical device in the study is portable, designed for the point of care environment, non-implantable, and includes at least one output interface. The main motivation for this study is the possible
Dalimar Velez; Michael Shanblatt
Background The bacterium Chlamydia trachomatis is one of the leading causes of sexually transmitted diseases worldwide. Since no simple and effective tool exists to diagnose C. trachomatis infections, we evaluated a novel point-of-care (POC) test, aQcare Chlamydia TRF kit, which uses europium-chelated nanoparticles and a time-resolved fluorescence reader. Methods The test performance was evaluated by comparing the results obtained using the novel POC testing kit with those obtained using a nucleic acid amplification test (NAAT), using 114 NAAT-positive and 327 NAAT-negative samples. Results The cut-off value of the novel test was 20.8 with a detection limit of 0.27 ng/mL. No interference or cross-reactivity was observed. Diagnostic accuracy showed an overall sensitivity of 93.0% (106/114), specificity of 96.3% (315/327), positive predictive value (PPV) of 89.8% (106/118), and negative predictive value (NPV) of 97.5% (315/323). The sensitivity of the novel test was much higher than that of currently available POC tests. Furthermore, the relative ease and short turnaround time (30 min) of this assay enables C. trachomatis-infected individuals to be treated without a diagnostic delay. Conclusions This simple and novel test is a potential tool to screen a larger population, especially those in areas with limited resources. PMID:25553280
Ham, Ji Yeon; Jung, Jaean; Hwang, Byung-Gap; Kim, Won-Jung; Kim, Young-Seop; Kim, Eun-Ju; Cho, Mi-Yeon; Hwang, Mi-Sun; Won, Dong Il
There is controversy regarding needle aspiration for primary spontaneous pneumothorax (PSP), with contradictory recommendations between the American College of Chest Physicians consensus statement (2001), which suggests that needle aspiration has little place in the management of PSP, and the British Thoracic Society guidelines (2010), which recommend that needle aspiration be attempted first for all cases of PSP where drainage is deemed necessary. Studies have shown that there is no significant difference between needle aspiration and tube thoracostomy with regard to safety, rates of immediate success, and early failure and has the advantages of decreasing pain and reducing rates of hospital admission and duration of hospital stay compared with tube thoracostomy. Point-of-care ultrasound (US) can facilitate needle aspiration by decreasing the risk of complications and detect pneumothorax resolution during or re-expansion after the procedure. This is a case series where the sonographic finding of the “lung point” on point-of-care US was used to facilitate needle aspiration to monitor pneumothorax resolution during or re-expansion after the procedure. We report 3 cases of PSP in adolescents presenting to the pediatric emergency department (ED), where needle aspiration was safely performed by using US to track the sonographic finding of the lung point. This technique allows the determination of pneumothorax resolution or re-expansion in real time. Point-of-care US may assist in the evaluation and management of spontaneous pneumothorax in the pediatric ED. Ultrasound-assisted needle aspiration may be a safe and less painful option for pediatric ED patients with PSP. PMID:24360316
Ng, Carrie; Tsung, James W
This report describes a patient with sub-massive pulmonary embolism (PE) who was successfully treated with half-dose thrombolytics guided by the use of point-of-care (POC) ultrasound. In this case, POC ultrasound was the only possible imaging since computed tomography was contraindicated. POC ultrasound demonstrated a deep vein thrombosis and evidence of cardiac strain. In situations or locations where definitive imaging is unobtainable, POC ultrasound can help diagnose submassive PE and direct the use of half-dose tissue plasminogen activator.
Amini, Richard; Panchal, Ashish R.; Bahner, David; Adhikari, Srikar
New mobile computing devices including personal digital assistants (PDAs) and tablet computers have emerged to facilitate data collection at the point of care. Unfortunately, little research has been reported regarding which device is optimal for a given care setting. In this study we created and compared functionally identical applications on a Palm operating system-based PDA and a Windows-based tablet computer for point-of-care documentation of clinical observations by eye care professionals when caring for patients with diabetes. Eye-care professionals compared the devices through focus group sessions and through validated usability surveys. We found that the application on the tablet computer was preferred over the PDA for documenting the complex data related to eye care. Our findings suggest that the selection of a mobile computing platform depends on the amount and complexity of the data to be entered; the tablet computer functions better for high volume, complex data entry, and the PDA, for low volume, simple data entry. PMID:16779128
Silvey, Garry M.; Macri, Jennifer M.; Lee, Paul P.; Lobach, David F.
This work demonstrates that a full laboratory-quality immunoassay can be run on a smartphone accessory. This low-cost dongle replicates all mechanical, optical, and electronic functions of a laboratory-based enzyme-linked immunosorbent assay (ELISA) without requiring any stored energy; all necessary power is drawn from a smartphone. Rwandan health care workers used the dongle to test whole blood obtained via fingerprick from 96 patients enrolling into care at prevention of mother-to-child transmission clinics or voluntary counseling and testing centers. The dongle performed a triplexed immunoassay not currently available in a single test format: HIV antibody, treponemal-specific antibody for syphilis, and nontreponemal antibody for active syphilis infection. In a blinded experiment, health care workers obtained diagnostic results in 15 min from our triplex test that rivaled the gold standard of laboratory-based HIV ELISA and rapid plasma reagin (a screening test for syphilis), with sensitivity of 92 to 100% and specificity of 79 to 100%, consistent with needs of current clinical algorithms. Patient preference for the dongle was 97% compared to laboratory-based tests, with most pointing to the convenience of obtaining quick results with a single fingerprick. This work suggests that coupling microfluidics with recent advances in consumer electronics can make certain laboratory-based diagnostics accessible to almost any population with access to smartphones. PMID:25653222
Laksanasopin, Tassaneewan; Guo, Tiffany W; Nayak, Samiksha; Sridhara, Archana A; Xie, Shi; Olowookere, Owolabi O; Cadinu, Paolo; Meng, Fanxing; Chee, Natalie H; Kim, Jiyoon; Chin, Curtis D; Munyazesa, Elisaphane; Mugwaneza, Placidie; Rai, Alex J; Mugisha, Veronicah; Castro, Arnold R; Steinmiller, David; Linder, Vincent; Justman, Jessica E; Nsanzimana, Sabin; Sia, Samuel K
Exposure to drugs and toxins is a major cause for patients' visits to the emergency department (ED). For most drugs-of-abuse intoxication, ED physicians are skeptical to rely on results of urine drug testing for emergent management decisions. This is partially because immunoassays, although rapid, have limitations in sensitivity and specificity and chromatographic assays, which are more definitive, are more labor intensive. Testing for toxic alcohols is needed, but rapid commercial assays are not available. ED physicians need stat assays for acetaminophen, salicylates, co-oximetry, cholinesterase, iron, and some therapeutic drugs that could be used as agents of self-harm. In this review, we look at the potential limitations of these screening tests and suggest improvements and innovations needed for better clinical utilization. New drugs of abuse should be sought and assays should be developed to meet changing abuse patterns. PMID:25337490
Glucose Tolerance Test Simulation, p. 1 Physiological Simulations: Plasma Glucose Regulation1 I by Bennett (1983). Annual Review of Medicine. 34, 295-309. This is in the stacks in the CHC Science Library fluid compartment"). Plasma is part of this compartment. One uses the extracellular fluid compartment
Florida, University of
Breast cancer-related lymphedema (BCRL) can be irreversible with profound negative impact on patients' quality of life. Programs that provide screening and active surveillance for BCRL are essential to determine whether early detection and intervention influences the course of lymphedema development. Established methods of quantitatively assessing lymphedema at early stages include "volume" methods such as perometry and bioimpedance spectroscopy. Here we demonstrate 1) Use of topographical techniques analogous to those used in corneal topography 2) Development of point-of-care lymphedema detection and characterization based on off-the-shelf hardward 3) The role of subsurface imaging 4) Multimodal diagnostics and integration yielding higher sensitivity/ specificity.
Sayegh, Samir I.; Taghian, Alphonse
Leveraging advances in consumer electronics and wireless telecommunications, low-cost, portable optical imaging devices have the potential to improve screening and detection of disease at the point of care in primary health care settings in both low- and high-resource countries. Similarly, real-time optical imaging technologies can improve diagnosis and treatment at the point of procedure by circumventing the need for biopsy and analysis by expert pathologists, who are scarce in developing countries. Although many optical imaging technologies have been translated from bench to bedside, industry support is needed to commercialize and broadly disseminate these from the patient level to the population level to transform the standard of care. This review provides an overview of promising optical imaging technologies, the infrastructure needed to integrate them into widespread clinical use, and the challenges that must be addressed to harness the potential of these technologies to improve health care systems around the world. PMID:25210062
Boppart, Stephen A; Richards-Kortum, Rebecca
'Point-of-care' (POC) diagnostics are a powerful emerging healthcare approach. They can rapidly provide statistically significant results, are simple to use, do not require specialized equipment and are cost-effective. For these reasons, they have the potential to play a major role in revolutionizing the diagnosis, initiation and monitoring of treatment of major global diseases. This review focuses on antibody-based POC devices that target four major global diseases: cardiovascular diseases, prostate cancer, HIV infection and tuberculosis. The key statistics and pathology of each disease is described in detail, followed by an in-depth discussion on emerging POC devices that target each disease, highlighting their potential and limitations. PMID:25300742
McPartlin, Daniel A; O'Kennedy, Richard J
Background Implementing semi-automated processes to efficiently match patients to clinical trials at the point of care requires both detailed patient data and authoritative information about open studies. Objective To evaluate the utility of the ClinicalTrials.gov registry as a data source for semi-automated trial eligibility screening. Methods Eligibility criteria and metadata for 437 trials open for recruitment in four different clinical domains were identified in ClinicalTrials.gov. Trials were evaluated for up to date recruitment status and eligibility criteria were evaluated for obstacles to automated interpretation. Finally, phone or email outreach to coordinators at a subset of the trials was made to assess the accuracy of contact details and recruitment status. Results 24% (104 of 437) of trials declaring on open recruitment status list a study completion date in the past, indicating out of date records. Substantial barriers to automated eligibility interpretation in free form text are present in 81% to up to 94% of all trials. We were unable to contact coordinators at 31% (45 of 146) of the trials in the subset, either by phone or by email. Only 53% (74 of 146) would confirm that they were still recruiting patients. Conclusion Because ClinicalTrials.gov has entries on most US and many international trials, the registry could be repurposed as a comprehensive trial matching data source. Semi-automated point of care recruitment would be facilitated by matching the registry's eligibility criteria against clinical data from electronic health records. But the current entries fall short. Ultimately, improved techniques in natural language processing will facilitate semi-automated complex matching. As immediate next steps, we recommend augmenting ClinicalTrials.gov data entry forms to capture key eligibility criteria in a simple, structured format. PMID:25334031
Pfiffner, Pascal B.; Oh, JiWon; Miller, Timothy A.; Mandl, Kenneth D.
We propose the use of a potentiometric biosensor that incorporates the efficient and specific molecular imprinting (MI) method with a self-assembled monolayer (SAM). We first tested the biosensor using carcinoembryonic antigen, CEA, a biomarker associated with pancreatic cancer. No change in detection efficiency was observed when detection was performed in the presence of 100% serum albumin, indicating that the sensor is able to discriminate for the template analyte even in concentrated solution of similar substances. Computer simulations of the protein structure were performed in order to estimate the changes in morphology and determine the sensitivity of the biosensor to conformational changes in the proteins. We found that even small changes in PH can generate rotation of the surface functional groups, without significant change in the morphology. Yet, the results show that only when the detection and imprinting conditions are similar, robust signals occurs. Hence we concluded that both morphology and surface chemistry play a role in the recognition.
Yu, Yingjie; Rafailovich, Miriam; Wang, Yantian; Ranjbaran, Alina; Wang, Tom; Nam, David
Background In tropical Africa, where the spectrum of the bacterial pathogens that cause fevers is poorly understood and molecular-based diagnostic laboratories are rare, the time lag between test results and patient care is a critical point for treatment of disease. Methodology/Principal Findings We implemented POC laboratory in rural Senegal to resolve the time lag between test results and patient care. During the first year of the study (February 2011 to January 2012), 440 blood specimens from febrile patients were collected in Dielmo and Ndiop villages. All samples were screened for malaria, dengue fever, Borrelia spp., Coxiella burnetii, Tropheryma whipplei, Rickettsia conorii, R. africae, R. felis, and Bartonella spp. Conclusions/Significance We identified DNA from at least one pathogenic bacterium in 80/440 (18.2%) of the samples from febrile patients. B. crocidurae was identified in 35 cases (9.5%), and R. felis DNA was found in 30 cases (6.8%). The DNA of Bartonella spp. was identified in 23/440 cases (4.3%), and DNA of C. burnetii was identified in 2 cases (0.5%). T. whipplei (0.2%) was diagnosed in one patient. No DNA of R. africae or R. conorii was identified. Among the 7 patients co-infected by two different bacteria, we found R. felis and B. crocidurae in 4 cases, B. crocidurae and Bartonella spp. in 2 cases, and B. crocidurae and C. burnetii in 1 case. Malaria was diagnosed in 54 cases. In total, at least one pathogen (bacterium or protozoa) was identified in 127/440 (28.9%) of studied samples. Here, the authors report the proof of concept of POC in rural tropical Africa. Discovering that 18.2% of acute infections can be successfully treated with doxycycline should change the treatment strategy for acute fevers in West Africa. PMID:23350001
Fenollar, Florence; Bassene, Hubert; Diatta, Georges; Tall, Adama; Trape, Jean-François; Drancourt, Michel; Raoult, Didier
Ovarian cancer is asymptomatic at early stages and most patients present with advanced levels of disease. Lack of cost-effective methods that can achieve frequent, simple and non-invasive testing hinders early detection and causes high mortality in ovarian cancer patients. Here, we report a simple and inexpensive microchip ELISA-based detection module that employs a portable detection system, i.e., a cell phone/charge-coupled device (CCD) to quantify an ovarian cancer biomarker, HE4, in urine. Integration of a mobile application with a cell phone enabled immediate processing of microchip ELISA results, which eliminated the need for a bulky, expensive spectrophotometer. The HE4 level detected by a cell phone or a lensless CCD system was significantly elevated in urine samples from cancer patients (n = 19) than normal healthy controls (n = 20) (p < 0.001). Receiver operating characteristic (ROC) analyses showed that the microchip ELISA coupled with a cell phone running an automated analysis application had a sensitivity of 89.5% at a specificity of 90%. Under the same specificity, the microchip ELISA coupled with a CCD had a sensitivity of 84.2%. In conclusion, integration of microchip ELISA with cell phone/CCD-based colorimetric measurement technology can be used to detect HE4 biomarker at the point-of-care (POC), paving the way to create bedside technologies for diagnostics and treatment monitoring. PMID:21881677
Wang, ShuQi; Zhao, Xiaohu; Khimji, Imran; Akbas, Ragip; Qiu, Weiliang; Edwards, Dale; Cramer, Daniel W.; Ye, Bin; Demirci, Utkan
We propose the use of a potentiometric biosensor that incorporates the efficient and specific molecular imprinting (MI) method with a self-assembled monolayer (SAM). We first tested the biosensor using carcinoembryonic antigen, CEA, a biomarker associated with pancreatic cancer. No change in detection efficiency was observed, indicating that the sensor is able to discriminate for the template analyte even in concentrated solution of similar substances. In addition, we use biosensor to discriminate normal fibrinogen and damaged fibrinogen, which is critical for the detection of bleeding disorder. Computer simulations of the protein structure were performed in order to estimate the changes in morphology and determine the sensitivity of the biosensor to conformational changes in the proteins. We found that even small changes in PH can generate rotation of the surface functional groups. Yet, the results show that only when the detection and imprinting conditions are similar, robust signals occurs. Hence we concluded that both morphology and surface chemistry play a role in the recognition.
Yu, Yingjie; Rafailovich, Miriam; Wang, Yantian; Kang, Yeona; Zhang, Lingxi; Rigas, Basil
MayoExpert is a multifaceted information system integrated with the electronic medical record (EMR) across Mayo Clinic's multisite health system. It was developed as a technology-based solution to manage information, standardize clinical practice, and promote and document learning in clinical contexts. Features include urgent test result notifications; models illustrating expert-approved care processes; concise, expert-approved answers to frequently asked questions (FAQs); a directory of topic-specific experts; and a portfolio for provider licensure and credentialing. The authors evaluate MayoExpert's reach, effectiveness, adoption, implementation, and maintenance. Evaluation data sources included usage statistics, user surveys, and pilot studies.As of October 2013, MayoExpert was available at 94 clinical sites in 12 states and contained 1,368 clinical topics, answers to 7,640 FAQs, and 92 care process models. In 2012, MayoExpert was accessed at least once by 2,578/3,643 (71%) staff physicians, 900/1,374 (66%) midlevel providers, and 1,728/2,291 (75%) residents and fellows. In a 2013 survey of MayoExpert users with 536 respondents, all features were highly rated (? 67% favorable). More providers reported using MayoExpert to answer questions before/after than during patient visits (68% versus 36%). During November 2012 to April 2013, MayoExpert sent 1,660 notifications of new-onset atrial fibrillation and 1,590 notifications of prolonged QT. MayoExpert has become part of routine clinical and educational operations, and its care process models now define Mayo Clinic best practices. MayoExpert's infrastructure and content will continue to expand with improved templates and content organization, new care process models, additional notifications, better EMR integration, and improved support for credentialing activities. PMID:25374037
Cook, David A; Sorensen, Kristi J; Nishimura, Rick A; Ommen, Steve R; Lloyd, Farrell J
Background Optimal treatment of acute ST-elevation myocardial infarction (STEMI) involves rapid diagnosis, and transfer to a cardiac centre capable of percutaneous coronary intervention (PCI) for immediate mechanical revascularisation. Successful treatment requires rapid return of perfusion to the myocardium achieved by thromboaspiration, passivation of the culprit lesion with stent scaffolding and systemic inhibition of thrombosis and platelet activation. A delicate balance exists between thrombosis and bleeding and consequently anti-thrombotic and antiplatelet treatment regimens continue to evolve. The desire to achieve reperfusion as soon as possible, in the setting of high platelet reactivity, requires potent and fast-acting anti-thrombotic/anti-platelet therapies. The associated bleeding risk may be minimised by use of short-acting anti-thrombotic intravenous agents. However, effective oral platelet inhibition is required to prevent recurrent thrombosis. The interaction between baseline platelet reactivity, timing of revascularisation and effective inhibition of thrombosis is yet to be formally investigated. Methods/Design We present a protocol for a prospective observational study in patients presenting with acute STEMI treated with primary PCI (PPCI) and receiving bolus/infusion bivalirudin and prasugrel therapy. The objective of this study is to describe variation in platelet reactivity, as measured by the multiplate platelet function analyser, at presentation, the end of the PPCI procedure and 1, 2, & 24 hours post-procedure. We intend to assess the prevalence of high residual platelet reactivity within 24 hours of PPCI in acute STEMI patients receiving prasugrel and bivalirudin. Additionally, we will investigate the association between high platelet reactivity before and after PPCI and the door-to-procedure completion time. This is a single centre study with a target sample size of 108 participants. Discussion The baseline platelet reactivity on presentation with a STEMI may impact on the effect of acute anti-thrombotic and anti-platelet therapy and expose patients to a heightened risk of bleeding or ongoing thrombosis. This study will define the baseline variation in platelet reactivity in a population of patients experiencing acute STEMI and assess the pharmacodynamic response to combined treatment with bivalirudin and prasugrel. The data obtained from this trial will be hypothesis generating for future trials testing alternative pharmacotherapies in the acute phase of treatment for STEMI. Trial registration This study has approval from Wiltshire research ethics committee (10/H0106/87) and is registered with current controlled trials (http://www.controlled-trials.com/ISRCTN82257414). PMID:24708700
Aims Point-of-care HbA1c is routine in clinical practice. Comparison of point-of-care HbA1c against laboratory measurements across sites and over time is warranted. Methods One hundred and twenty-one young persons with Type 1 diabetes from four centres provided 450 paired samples collected over 10 months for point-of-care HbA1c and central laboratory-based high-performance liquid chromatography (HPLC) HbA1c determinations. Change in HbA1c over time was assessed by difference from initial to final HbA1c and by growth modelling with annualized slope calculation. Change in HbA1c was categorized as improved (decrease of ? 0.5% or negative slope), no change (± 0.4% of initial HbA1c or slope = 0) or worsened (increase of ? 0.5% or positive slope). Results The 450 paired samples (median of four pairs/patient) were highly correlated (r = 0.97, P < 0.0001), as were time-specific and site-specific pairs (r = 0.94 to 0.98, P < 0.0001). Initial-to-final point-of-care HbA1c and HPLC HbA1c changes were 0.3 ± 1.1% (range ?2.7 to 4.1) and 0.4 ± 1.2% (–3.9 to 4.5), respectively, with 21% of patients (n = 26) discordant for change categories. ?HbA1c by point-of-care HbA1c vs. HPLC HbA1c differed across the HbA1c range and by ? 0.5% absolute difference in ?HbA1c in 14 (54%) of the 26 patients discordant for HbA1c change categories. Mean annual HbA1c slope was 0.4 ± 1.5% (?5.4 to 4.8) for point-of-care HbA1c and 0.4 ± 1.6% (?6.9 to 5.2) for HPLC HbA1c, with 18% (n = 22 pairs) discordant for change categories. Conclusions Assessment of absolute HbA1c change may not be different for point-of-care HbA1c compared with HPLC HbA1c; however, misclassification of patients by discrete cut-off values may occur with point-of-care HbA1c compared with HPLC HbA1c determinations. PMID:21824185
Alleyn, C. R.; Laffel, L. M. B.; Volkening, L. K.; Anderson, B. J.; Nansel, T. R.; Wysocki, T.; Weissberg-Benchell, J
It has recently been demonstrated that 2-aminoacetophenone (2-AA) is a chemical indicator in exhaled air/breath of Pseudomonas aeruginosa infection associated with progressive life threatening decline of lung function in cystic fibrosis sufferers [Scott-Thomas et al., BMC Pulm. Med., 2010, 10, 56]. Currently the detection of 2-AA involves laboratory based instrumentation such as mass spectrometry and a hand-held point-of-care type breath device would be ideal in providing real-time results within seconds to accelerate patient care decision-making processes. To this end, we demonstrate proof-of-concept that the chemical marker 2-AA, indicative of Pseudomonas aeruginosa infection, can be measured using electrochemical based sensing strategies. A range of commercially available electrode substrates are explored demonstrating for the first time that 2-AA is electrochemically active within aqueous based solutions providing an (electro)analytical signal. Glassy carbon, boron-doped diamond and platinum electrodes have been explored towards the electrochemical oxidation of 2-AA. Electrode fouling is observed requiring pre-treatment in the form of mechanical polishing between voltammetric scans and measurements. To alleviate this, screen-printed graphite electrodes are shown to be a more viable option for implementation into breath sensing devices and overcome the fouling problem since due to their low cost and disposable nature, a new electrode can be used for each measurement. The analytical utility of the platinum, screen-printed and boron-doped diamond electrodes were found to correspond to 6.85, 7.66 and 4.86 mM respectively. The challenges associated with the electrochemical sensing of 2-AA in breath that need to be overcome are discussed. This generic approach where electrochemical based technology is used to provide measurements for chemical markers in exhaled air/breath for medical diagnostics termed electrochemical breathprints (ec-breathprints), has the potential to be developed into a hand-held point-of-care breath diagnostic tool for identifying Pseudomonas aeruginosa infection in exhaled air/breath. PMID:24926967
Metters, Jonathan P; Kampouris, Dimitrios K; Banks, Craig E
Early diagnosis of tuberculosis can dramatically reduce both its transmission and the associated death rate. The extremely slow growth rate of the causative pathogen, Mycobacterium tuberculosis (Mtb), however, makes this challenging at the point of care, particularly in resource-limited settings. Here we report the use of BlaC (an enzyme naturally expressed/secreted by tubercle bacilli) as a marker and the design of BlaC-specific fluorogenic substrates as probes for Mtb detection. These probes showed an enhancement by 100-200 times in fluorescence emission on BlaC activation and a greater than 1,000-fold selectivity for BlaC over TEM-1 ?-lactamase, an important factor in reducing false-positive diagnoses. Insight into the BlaC specificity was revealed by successful co-crystallization of the probe/enzyme mutant complex. A refined green fluorescent probe (CDG-OMe) enabled the successful detection of live pathogen in less than ten minutes, even in unprocessed human sputum. This system offers the opportunity for the rapid, accurate detection of very low numbers of Mtb for the clinical diagnosis of tuberculosis in sputum and other specimens.
Xie, Hexin; Mire, Joseph; Kong, Ying; Chang, Mihee; Hassounah, Hany A.; Thornton, Chris N.; Sacchettini, James C.; Cirillo, Jeffrey D.; Rao, Jianghong
Lateral flow devices are commonly used for many point-of-care (POC) applications in low-resource settings. However, they lack the sensitivity needed for many analytes relevant in the diagnosis of diseases. One approach to achieve higher sensitivity is signal amplification, which is commonly used in laboratory assays, but uses reagents that require refrigeration and inherently requires multiple assay steps not normally compatible with POC settings. Enzyme-based signal amplification, such as the one used in ELISA, could greatly improve the limit of detection if it were translated to a format compatible with POC requirements. A signal-amplified POC device not only requires the reagents to be stored in a stable form, but also requires automation of the multiple sequential steps of signal amplification protocols. Here, we describe a method for the long-term dry storage of ELISA reagents: horseradish peroxidase (HRP) conjugated antibody label and its colorimetric substrate diaminobenzidine (DAB). The HRP conjugate retained ?80% enzymatic activity after dry storage at 45 °C for over 5 months. The DAB substrate was also stable at 45 °C and exhibited no detectable loss of activity over 3 months. These reagents were incorporated into a two-dimensional paper network (2DPN) device that automated the steps of ELISA for the detection of a malarial biomarker. These results demonstrate the potential of enzyme-based signal amplification for enhanced sensitivity in POC devices for low resource settings. PMID:24496140
Ramachandran, Sujatha; Fu, Elain; Lutz, Barry; Yager, Paul
A device for measuring human breath ammonia was developed based on a single use, disposable, inkjet printed ammonia sensor fabricated using polyaniline nanoparticles. The device was optimized for sampling ammonia in human breath samples by addressing issues such as variations in breath sample volume, flow rate, sources of oral ammonia, temperature and humidity. The resulting system was capable of measuring ammonia in breath from 40 to 2993 ppbv (r(2 )= 0.99, n = 3) as correlated with photoacoustic laser spectroscopy and correlation in normal human breath samples yielded a slope of 0.93 and a Pearson correlation coefficient of 0.9705 (p < 0.05, n = 11). Measurement of ammonia in the breath of patients with end-stage kidney disease demonstrated its significant reduction following dialysis, while also correlating well with blood urea nitrogen (BUN) (r = 0.61, p < 0.01, n = 96). Excellent intraindividual correlations were demonstrated between breath ammonia and BUN (0.86 to 0.96), which demonstrates the possibility of using low cost point of care breath ammonia systems as a noninvasive means of monitoring kidney dysfunction and treatment. PMID:24299143
Hibbard, Troy; Crowley, Karl; Kelly, Frank; Ward, Frank; Holian, John; Watson, Alan; Killard, Anthony J
This chapter describes the development of microfluidic toner-based analytical devices (?TADs) to perform clinical diagnostics using a scanner or cell-phone camera. ?TADs have been produced in a platform composed of polyester and toner by the direct-printing technology (DPT) in a matter of minutes. This technology offers simplicity and versatility, and it does not require any sophisticated instrumentation. Toner-based devices integrate the current generation of disposable analytical devices along paper-based chips. The cost of one ?TAD has been estimated to be lower than $0.10. In addition, these platforms are lightweight and portable thus enabling their use for point-of-care applications. In the last 5 years, great efforts have been dedicated to spread out the use of ?TADs in bioassays. The current chapter reports the fabrication of printed microplates and integrated microfluidic toner-based devices for dengue diagnostics and rapid colorimetric assays with clinically relevant analytes including cholesterol, triglycerides, total proteins, and glucose. The use of ?TADs associated with cell-phone camera may contribute to the health care, in special, to people housed in developing regions or with limited access to clinics and hospitals. PMID:25626533
Oliveira, Karoliny Almeida; de Souza, Fabrício Ribeiro; de Oliveira, Cristina Rodrigues; da Silveira, Lucimeire Antonelli; Coltro, Wendell Karlos Tomazelli
Purpose. Monitoring patients' international normalized ratio (INR) within a family medicine setting can be challenging. Novel methods of doing this effectively and in a timely manner are important for patient care. The purpose of this study was to determine the effectiveness of a pharmacist-led point-of-care (POC) INR clinic. Methods. At a community-based academic Family Health Team in Toronto, Canada, charts of patients with atrial fibrillation managed by a pharmacist with usual care (bloodtesting at lab and pharmacist follow up of INR by phone) from February 2008 to April 2008 were compared with charts of patients attending a weekly POC INR clinic from February 2010 to April 2010. Time in therapeutic range (TTR) was measured for both groups. Results. 119 patient charts were reviewed and 114 had TTR calculated. After excluding patients with planned inconsistent Coumadin use (20), such as initiating Coumadin treatment or stopping for a surgical procedure, the mean TTR increased from 64.41% to 77.09% with the implementation of the POC clinic. This was a statistically significant difference of 12.68% (CI: 1.18, 24.18; P = 0.03). Conclusion. A pharmacist-led POC-INR clinic improves control of anticoagulation therapy in patients receiving warfarin and should be considered for implementation in other family medicine settings. PMID:24455250
Rossiter, Jennifer; Soor, Gursharan; Aliarzadeh, Babak; Lake, Jennifer
Our POC (Point of Care) device is intended to be a diagnostic tool for routine use in the clinical sector. The validation of the whole procedure, including bacterial genomic DNA isolation and the Real Time detection of Salmonella spp., was conducted on 29 clinical stool samples that had been diagnosed with Salmonella spp. by a routine culture technique. The entire process was achieved in a single microfluidic chip within 35 min. In comparison to the culture reference method that is used in the clinical laboratories, this new device performed well in regards to the analytical parameters of sensitivity, specificity and accuracy. Therefore, the POC device reported in this study proved to be very appropriate for the fully integrated analysis system. To the best of our knowledge, this is the first work to report the sample preparation and followed by Real Time PCR (Polymerase Chain Reaction) on a single 2.5 ?l chamber chip for the detection of Salmonella spp. bacteria in stool samples. PMID:22226408
Verdoy, Dolores; Barrenetxea, Ziortza; Berganzo, Javier; Agirregabiria, Maria; Ruano-López, Jesús M; Marimón, José M; Olabarría, Garbiñe
An evaluation was commissioned to generate evidence on the impact of PIMA point-of-care CD4+ count machines in maternal and new-born child health settings in Zimbabwe; document best practices, lessons learned, challenges, and recommendations related to scale up of this new technology. A mixed methodology approach that included 31 in-depth interviews with stakeholders involved in procurement, distribution, and use of the POC machines was employed. Additionally, data was also abstracted from 207 patient records from 35 sites with the PIMA POC CD4+ count machines and 10 other comparative sites without the machine. A clearer training strategy was found to be necessary. The average time taken to initiate clients on antiretroviral treatment (ART) was substantially less, 15 days (IQR-1-149) for sites with a PIMA POC machine as compared to 32.7 days (IQR-1-192) at sites with no PIMA POC machine. There was general satisfaction because of the presence of the PIMA POC CD4+ count machine at sites that also initiated ART. PMID:24847177
Mtapuri-Zinyowera, Sekesai; Chiyaka, Edward T.; Mushayi, Wellington; Musuka, Godfrey; Naluyinda-Kitabire, Florence; Mushavi, Angella; Chikwasha, Vasco
Abstract The application of emerging nanotechnology to the practice of medicine represents a frontier of nanomedicine. Nanomedicine has been defined as a science which emphasizes the use of nanoscale tools in conjunction with background knowledge of the human body for medical diagnosis and treatment. Application of nanomedicine in EM may give EM providers the opportunity to diagnose and treat life-threatening diseases in a shorter period of time. These applications include diagnostic utilities, preventive medicine, targeted pharmacotherapy, and tissue regeneration. PMID:23351236
Myocardial infarction (MI) is the main cause of death all over the world. Biomarkers of cardiac necrosis are of great importance\\u000a in the diagnosis of MI. The aim of this study was to determine probable changes of creatine kinase MB isoform (CK-MB) levels\\u000a in saliva of patients with acute MI. A case–control study was carried out on 30 patients with
Iraj Mirzaii-Dizgah; Seyed Fakhreddin Hejazi; Esmail Riahi; Mohammad Mohsen Salehi
Contamination of a point-of-care ultrasound system (POCUS) mainly involved electrocardiography accessories and included pathogenic microorganisms. The use of a glass-sealed control panel significantly facilitated its cleaning and reduced its bacterial contamination compared with a standard control panel. Overall hand hygiene compliance during examinations with POCUS was poor. PMID:25419778
Mekontso Dessap, Armand; Jansen, Chloe; Boissier, Florence; Razazi, Keyvan; de Prost, Nicolas; Michaud, Gaël; Cizeau, Florence; Ducellier, David; Abid, Shariq; Decousser, Jean-Winoc; Brun-Buisson, Christian
Accurate assessment of diabetes polyneuropathy (DPN) is important in the prevention of foot ulcerations and amputations. Simple screening methods including the 10 g monofilament and the 128-Hz tuning fork are not sensitive enough nor intended for detection of early neuropathy, while more confirmatory tests such as nerve conduction studies are not universally available. We evaluated a rapid, low-cost, point-of-care nerve conduction device (POCD; NC-stat®|DPNCheck™) for the assessment of DPN and compared it with the LDIFLARE technique-an established method for early detection of small fibre dysfunction. A total of 162 patients with diabetes (DM) and 80 healthy controls (HC) were recruited. Based on the 10-point Neuropathy Disability Score (NDS), DPN was categorized into none (<2), mild (3-5) moderate (6-7), and severe (8-10). The LDIFLARE was performed in all patients according to previously described methodology. The associations between POCD outcomes and the LDIFLARE within the NDS categories were evaluated using regression analysis. In HC and DM, SNCV measured with the POCD correlated significantly with the LDIFLARE technique (r < 0.90 and r = 0.78, respectively) as did SNAP (r = 0.88 and r = 0.73, respectively); in addition, significance was found in all categories of DPN (r = 0.64 to 0.84; p= ? 0.03). ROC curves within each category of DPN showed that the POCD was sensitive in the assessment of DPN. We report highly significant linear relationships between the POCD with both comparators-the LDIFLARE technique and clinical neuropathy scores. Thus, the NC-stat|DPNCheck™ system appears to be an excellent adjunctive diagnostic tool for diagnosing DPN in the clinical setting. PMID:25231114
Sharma, Sanjeev; Vas, Prashanth Rj; Rayman, Gerry
This descriptive study replicates and extends previous research on advanced practice RNs and the (1) reference resources available to them at the point of care, (2) resources they use to inform their clinical practice, and (3) resources they are accessing from handheld electronic devices such as PDAs, smartphones, and tablet computers during practice. These elements formed the purpose of the current study. A sample of advanced practice RNs from Texas Public Health Region 11 was surveyed. Available resources were current journals appropriate to setting and current clinical guidelines. These advanced practice RNs "always or frequently" based their professional practice on personal experience of caring for patients/clients over time, information learned in college/university, and information learned about each patient/client as an individual. Responses for Hispanic respondents as well as electronic device users were similar. Content and features accessed daily by handheld computer devices were reference materials, e-mail, address/phonebook, Internet access other than e-mail, calendar/date book, alarm/reminder, calculator, and memo pad. Software installed on handheld devices and used daily included drug references, medical text/reference book, medical math/formula calculator, practice guidelines, and language translator/dictionary. Respondents who did not report using handheld devices at work were older, had more years in advanced practice nursing, and were more likely to work in a hospital, birthing center, or institution such as a prison, school, or military facility. There was no difference in resource or electronic device use by Hispanic advanced practice RNs. Electronic resources for practice are growing and being used by advanced practice RNs. Consideration should be given to incorporating evaluation and implementation of electronic clinical resources into advanced practice RN educational programs. Future research should include greater detail about the origin of information used in practice. Patient responses to the use of electronic handheld devices in clinical settings needs illuminating. PMID:24226042
Bischoff, Whitney Rogers; Hinojosa, Rogelio H
Objective Many mobile phone resources have been developed to increase access to health education in the developing world, yet few studies have compared these resources or quantified their performance in a resource-limited setting. This study aims to compare the performance of resident physicians in answering clinical scenarios using PubMed abstracts accessed via the PubMed for Handhelds (PubMed4Hh) website versus medical/drug reference applications (Medical Apps) accessed via software on the mobile phone. Methods A two-arm comparative study with crossover design was conducted. Subjects, who were resident physicians at the University of Botswana, completed eight scenarios, each with multi-part questions. The primary outcome was a grade for each question. The primary independent variable was the intervention arm and other independent variables included residency and question. Results Within each question type there were significant differences in ‘percentage correct’ between Medical Apps and PubMed4Hh for three of the six types of questions: drug-related, diagnosis/definitions, and treatment/management. Within each of these question types, Medical Apps had a higher percentage of fully correct responses than PubMed4Hh (63% vs 13%, 33% vs 12%, and 41% vs 13%, respectively). PubMed4Hh performed better for epidemiologic questions. Conclusions While mobile access to primary literature remains important and serves an information niche, mobile applications with condensed content may be more appropriate for point-of-care information needs. Further research is required to examine the specific information needs of clinicians in resource-limited settings and to evaluate the appropriateness of current resources in bridging location- and context-specific information gaps. PMID:23535665
Goldbach, Hayley; Chang, Aileen Y; Kyer, Andrea; Ketshogileng, Dineo; Taylor, Lynne; Chandra, Amit; Dacso, Matthew; Kung, Shiang-Ju; Rijken, Taatske; Fontelo, Paul; Littman-Quinn, Ryan; Seymour, Anne K; Kovarik, Carrie L
Objectives. This study was designed to assess the clinical applicability of a Point-of-Care (POC) ultrasound curriculum into an intensive care unit (ICU) fellowship program and its impact on patient care. Methods. A POC ultrasound curriculum for the surgical ICU (SICU) fellowship was designed and implemented in an urban, academic tertiary care center. It included 30 hours of didactics and hands-on training on models. Minimum requirement for each ICU fellow was to perform 25–50 exams on respective systems or organs for a total not less than 125 studies on ICU. The ICU fellows implemented the POC ultrasound curriculum into their daily practice in managing ICU patients, under supervision from ICU staff physicians, who were instructors in POC ultrasound. Impact on patient care including finding a new diagnosis or change in patient management was reviewed over a period of one academic year. Results. 873 POC ultrasound studies in 203 patients admitted to the surgical ICU were reviewed for analysis. All studies included were done through the POC ultrasound curriculum training. The most common exams performed were 379 lung/pleural exams, 239 focused echocardiography and hemodynamic exams, and 237 abdominal exams. New diagnosis was found in 65.52% of cases (95% CI 0.590, 0.720). Changes in patient management were found in 36.95% of cases (95% CI 0.303, 0.435). Conclusions. Implementation of POC ultrasound in the ICU with a structured fellowship curriculum was associated with an increase in new diagnosis in about 2/3 and change in management in over 1/3 of ICU patients studied. PMID:25478217
Killu, Keith; Coba, Victor; Mendez, Michael; Reddy, Subhash; Adrzejewski, Tanja; Huang, Yung; Ede, Jessica; Horst, Mathilda
Background Universal HIV pediatric screening offered at postnatal points of care (PPOC) is an entry point for early infant diagnosis (EID). We assessed the parents' acceptability of this approach in Abidjan, Côte d'Ivoire. Methods In this cross-sectional study, trained counselors offered systematic HIV screening to all children aged 6–26 weeks attending PPOC in three community health centers with existing access to HAART during 2008, as well as their parents/caregivers. HIV-testing acceptability was measured for parents and children; rapid HIV tests were used for parents. Both parents' consent was required according to the Ivorian Ethical Committee to perform a HIV test on HIV-exposed children. Free HIV care was offered to those who were diagnosed HIV-infected. Findings We provided 3,013 HIV tests for infants and their 2,986 mothers. While 1,731 mothers (58%) accepted the principle of EID, only 447 infants had formal parental consent 15%; 95% confidence interval (CI): [14%–16%]. Overall, 1,817 mothers (61%) accepted to test for HIV, of whom 81 were HIV-infected (4.5%; 95% CI: [3.5%–5.4%]). Among the 81 HIV-exposed children, 42 (52%) had provided parental consent and were tested: five were HIV-infected (11.9%; 95% CI: [2.1%–21.7%]). Only 46 fathers (2%) came to diagnose their child. Parental acceptance of EID was strongly correlated with prenatal self-reported HIV status: HIV-infected mothers were six times more likely to provide EID parental acceptance than mothers reporting unknown or negative prenatal HIV status (aOR: 5.9; 95% CI: [3.3–10.6], p?=?0.0001). Conclusions Although the principle of EID was moderately accepted by mothers, fathers' acceptance rate remained very low. Routine HIV screening of all infants was inefficient for EID at a community level in Abidjan in 2008. Our results suggest the need of focusing on increasing the PMTCT coverage, involving fathers and tracing children issued from PMTCT programs in low HIV prevalence countries. PMID:23990870
Ndondoki, Camille; Brou, Hermann; Timite-Konan, Marguerite; Oga, Maxime; Amani-Bosse, Clarisse; Menan, Hervé; Ekouévi, Didier; Leroy, Valériane
Background: Screening for Down syndrome in the first trimester by a combination of fetal nuchal translucency thickness and maternal serum pregnancy-associated plasma protein A (PAPP-A) and free -human chorionic gonadotropin has been shown to be effective and effi- cient. We aimed to develop a fast point-of-care assay that could be placed in one-stop clinics for the measure- ment of PAPP-A.
Qiu-Ping Qin; Michael Christiansen; Kim Pettersson
The use of high-dose vitamin C (hdVC, 66?mg/kg/hour × 18 hours) infusion is a useful adjunct to reducing fluid requirements during resuscitation of burn shock. Routine point-of-care glucose (POCG) analysis has been inaccurately high in observed patients undergoing hdVC. Inaccurate POCG could potentially lead to iatrogenic hypoglycemia if the fictitious hyperglycemia is treated with insulin. This study is a retrospective analysis of plasma glucose measurements from a central laboratory (LG) compared with POCG during and 24 hours after hdVC infusion. Records of adult patients receiving hdVC infusions during burn resuscitation over 1 year were reviewed. Charts selected for analysis included those with glucose measurements using POCG and LG that were taken simultaneously, during hdVC infusion, and 24 hours after completion. All specimens were drawn from arterial lines. POCG was measured with Accu-Chek Inform (Roche, Indianapolis, IN) and LG was measured by Siemens Dimension Vista 500 (Siemens, Deerfield, IL) using biochromic analysis. Nonparametric statistical analysis was performed using Wilcoxon's matched pairs test and Spearman correlation with significance at P < .05. Of 18 adult patients undergoing burn resuscitation with hdVC infusion, 5 were chosen for analysis (%TBSA 40?±?15; age 51?±?18). All data were pooled with 11 comparisons both during and after hdVC. The mean POCG (225?±?71) was significantly higher than mean LG (138?±?41) on hdVC (P = .002). There was no difference between POCG (138?±?30) and LG (128?±?23) after hdVC was finished (P = .09). There was a negative correlation between POCG and LG on hdVC (-0.64, P = .04) and a positive correlation off hdVC (0.89, P = .0005). POCG analysis during hdVC infusion is significantly higher than laboratory glucose measurements. Once the hdVC infusion is complete, POCG and laboratory glucose measurements are not statistically different. Treating erroneously high glucose based on POC testing is potentially dangerous and could lead to hypoglycemia and seizures. PMID:25162951
Kahn, Steven A; Lentz, Christopher W
Master project: Ebola point-of-care diagnostics development for low-resource settings A padlock methods that are sensitive, cheap and simple to perform are desirable. The current situation of the Ebola
Emergency Diagnostics, Homeland Security, Epidemiological Preparedness and the high cost of the Health Care Systems have increased demand for affordable and mobile point of care (POC) devices with highest sensitivity, specificity and rapid time to result. We have developed pocket and brief case sized systems for point of care and field based tests based on fluorescence read-out. The core consists
Konrad Faulstich; Klaus Haberstroh
The rapid development and updates of mobile medical resource applications (apps) highlight the need for an evaluation tool to assess the content of these resources. The purpose of the study was to develop and test a new evaluation rubric for medical resource apps. The evaluation rubric was designed using existing literature and through a collaborative effort between a hospital and an academic librarian. Testing found scores ranging from 23% to 88% for the apps. The evaluation rubric proved able to distinguish levels of quality within each content component of the apps, demonstrating potential for standardization of medical resource app evaluations. PMID:25611442
Butcher, Robyn; MacKinnon, Martin; Gadd, Kathleen; LeBlanc-Duchin, Denise
We present here research work on two optical biosensors which have been developed within two separate European projects (6th and 7th EU Framework Programmes). The biosensors are based on the idea of a disposable biochip, integrating photonics and microfluidics, optically interrogated by a multichannel interrogation platform. The objective is to develop versatile tools, suitable for performing screening tests at Point
Domenico Giannone; Andrzej Kazmierczak; Fabian Dortu; Laurent Vivien; Hans Sohlström
Human illnesses caused by food pathogen are cost-generating problem in societies all over the world. The portable, sensitive and cheap devices for rapid detection of these pathogen are in great interest of many research groups. In this paper the description and first results of test of a miniaturized system for detection of common food pathogens by a real-time PCR is
R. Walczak; J. A. Dziuban; J. Koszur; D. D. Bang; J. Ruano-Lopez
This review investigates optical sensor platforms for protein multiplexing, the ability to analyze multiple analytes simultaneously. Multiplexing is becoming increasingly important for clinical needs because disease and therapeutic response often involve the interplay between a variety of complex biological networks encompassing multiple, rather than single, proteins. Multiplexing is generally achieved through one of two routes, either through spatial separation on a surface (different wells or spots) or with the use of unique identifiers/labels (such as spectral separation-different colored dyes, or unique beads-size or color). The strengths and weaknesses of conventional platforms such as immunoassays and new platforms involving protein arrays and lab-on-a-chip technology, including commercially-available devices, are discussed. Three major public health concerns are identified whereby detecting medically-relevant markers using Point-of-Care (POC) multiplex assays could potentially allow for a more efficient diagnosis and treatment of diseases. PMID:25429414
Spindel, Samantha; Sapsford, Kim E
This review investigates optical sensor platforms for protein multiplexing, the ability to analyze multiple analytes simultaneously. Multiplexing is becoming increasingly important for clinical needs because disease and therapeutic response often involve the interplay between a variety of complex biological networks encompassing multiple, rather than single, proteins. Multiplexing is generally achieved through one of two routes, either through spatial separation on a surface (different wells or spots) or with the use of unique identifiers/labels (such as spectral separation—different colored dyes, or unique beads—size or color). The strengths and weaknesses of conventional platforms such as immunoassays and new platforms involving protein arrays and lab-on-a-chip technology, including commercially-available devices, are discussed. Three major public health concerns are identified whereby detecting medically-relevant markers using Point-of-Care (POC) multiplex assays could potentially allow for a more efficient diagnosis and treatment of diseases. PMID:25429414
Spindel, Samantha; Sapsford, Kim E.
The growing need to gain efficiencies within a home care setting has prompted home care practitioners to focus on health informatics to address the needs of an aging clientele. The remote and heterogeneous nature of the home care environment necessitates the use of non-intrusive client monitoring and a portable, point-of-care graphical user interface. Using a grounded theory approach, this article examines the simulated use of a graphical user interface by practitioners in a home care setting to explore the salient features of monitoring the activity of home care clients. The results demonstrate the need for simple, interactive displays that can provide large amounts of geographical and temporal data relating to patient activity. Additional emerging themes from interviews indicate that home care professionals would use a graphical user interface of this type for patient education and goal setting as well as to assist in the decision-making process of home care practitioners. PMID:24835146
Canally, Culum; Doherty, Sean; Doran, Diane M; Goubran, Rafik A
Objective-To determine the effect of PCV on veterinary point-of-care (POC) glucometer measurements in canine blood samples and develop a formula to correct the glucose concentration as measured by a point-of-care glucometer (POCgluc) given a known PCV. Design-Experimental and prospective study. Samples-Blood samples from 6 healthy dogs and from 30 hospitalized dogs. Procedures-60 mL of heparinized blood was obtained from each of 6 healthy dogs. Samples were processed into packed RBCs and plasma. Packed RBCs were resuspended with plasma to achieve a range of PCVs from 0% to 94%. Duplicate POCgluc and PCV measurements were obtained for each dilution; following POCgluc measurements, plasma samples were analyzed for glucose concentration by a clinical laboratory biochemical analyzer (LABgluc). A correction formula for POCgluc was developed. Measurements of POCgluc, PCV, and LABgluc were also determined from blood samples of 30 dogs admitted to the veterinary teaching hospital. Results-Values of LABgluc for each sample were similar at any PCV. As PCV decreased, POCgluc was falsely increased; as PCV increased, POCgluc was falsely decreased, compared with LABgluc. The absolute difference between POCgluc and LABgluc increased as the PCV changed from 50%. Compared with POCgluc, the corrected POCgluc had a significantly improved correlation with LABgluc, which was also reflected in improvements in Clarke and consensus error grid analyses. Conclusions and Clinical Relevance-Results indicated that in dogs with hemodilution or hemoconcentration, POCgluc did not reflect actual patient glucose concentrations. Use of a correction formula reduced this error. Corrected POCgluc data had strong, significant correlations with LABgluc data. PMID:25587730
Lane, Selena L; Koenig, Amie; Brainard, Benjamin M
Many new and exciting portable HIV viral load testing technologies are emerging for use in global medicine. While the potential to provide fast, isothermal, and quantitative molecular diagnostic information to clinicians in the field will soon be a reality, many of these technologies lack a robust front end for sample clean up and nucleic acid preparation. Such a technology would enable many different downstream molecular assays. Here, we present a portable system for centrifuge-free room temperature nucleic acid extraction from small volumes of whole blood (70 µL), using only thermally stable reagents compatible with storage and transport in low resource settings. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis of simulated samples demonstrate a lower limit of detection of 1000 copies/ml, with the ability to detect differences in viral load across four orders of magnitude. The system can also be used to store extracted RNA on detachable cartridges for up to one week at ambient temperature, and can be operated using only hand generated air pressure. PMID:23914255
Byrnes, Samantha; Fan, Andy; Trueb, Jacob; Jareczek, Francis; Mazzochette, Mark; Sharon, Andre; Sauer-Budge, Alexis F.; Klapperich, Catherine M.
We developed a wireless auto-tracking system for tracking clinical intervention such as drug administrations and blood tests at the patient bedside. The system can not only authenticate patients and nurses, but also confirm medications and provide relevant information, depending on the clinical situation and personnel location. We conducted a feasibility experiment and examined whether or not the system could work as a patient safety measure in terms of reducing misidentifications of patients and medical errors including wrong medication type, dose, time, and route. Also, the duration of clinical interventions in the system were measured to compare with the BCMA system. Moreover, we conducted a qualitative evaluation with nurses and received feedback clarifying their perceptions of the system. The results showed that the system correctly recognized medical staff, patient ID, and medication data in real time. With regards to workflow time, a significant reduction of time of clinical interventions was observed, when compared to a bar-coding system. In addition, on the nurses' evaluation, we received mostly positive comments although they also clarified some issues to consider with regards to operability and privacy issues. We concluded that the system had great potential for reducing medical errors and nurse workload with high efficiency. PMID:20471637
Ohashi, Kumiko; Ota, Sakiko; Ohno-Machado, Lucila; Tanaka, Hiroshi
Background Despite major public health initiatives and the existence of efficacious treatment regimes, tuberculosis (TB) remains a threat, particularly in resource-limited settings. A significant part of the problem is the difficulty of rapidly identifying infected individuals, and as a result, there has been renewed interest in developing better diagnostics for infection or disease caused by Mycobacterium tuberculosis. Many of the existing tools, however, have limitations such as poor sensitivity or specificity, or the need for well-equipped laboratories to function effectively. Serodiagnostic approaches in particular have long drawn attention, due to their potential utility in large field studies, particularly in resource-poor settings. Unfortunately none of the serodiagnostic approaches have so far proven useful under field conditions. Results We screened a large panel of antigens with serodiagnostic potential by ELISA and selected a subpanel that was strongly and broadly recognised by TB patients, but not by controls. These antigens were then formulated into a simple immuno-chromatographic lateral flow assay format, suitable for field use, and tested against panels of plasma and blood samples from individuals with different clinical status (confirmed TB patients, household contacts, and apparently healthy community controls), recruited from Ethiopia (a highly TB-endemic country) and Turkey (a TB meso-endemic country). While specificity was good (97-100% in non TB-endemic controls), the sensitivity was not as high as expected (46-54% in pulmonary TB, 25-29% in extra-pulmonary TB). Conclusions Though below the level of sensitivity the consortium had set for commercial development, the assay specifically identified M. tuberculosis-infected individuals, and provides a valuable proof of concept. PMID:23688126
According to the World Health Organization, cardiovascular disease is the most common cause of death in the world. In the US, over 115 million people visit the emergency department (ED), 5 million of which may have acute coronary syndrome (ACS). Cardiac biomarkers can provide early identification and diagnosis of ACS, and can provide information on the prognosis of the patient by assessing the risk of death. In addition, the biomarkers can serve as criteria for admission, indicate possibility of re-infarction, or eliminate ACS as a diagnosis altogether. We propose a SERSbased multi-marker approach towards a point-of-care diagnostic system for ACS. Using a nanofluidic device consisting of a microchannel leading into a nanochannel, we formed SERS active sites by mechanically aggregating gold particles (60 nm) at the entrance to the nanochannel (40nm×1?m). The induced capillary flow produces a high density of aggregated nanoparticles at this precise region, creating areas with enhanced electromagnetic fields within the aggregates, shifting the plasmon resonance to the near infrared region, in resonance with incident laser wavelength. With this robust sensing platform, we were able to obtain qualitative information of brain natriuretic peptide (biomarker of ventricular dysfunction or pulmonary stress), troponin I (biomarker of myocardial necrosis), and C-reactive protein (biomarker of inflammation potentially caused by atherosclerosis).
Benford, Melodie E.; Wang, Miao; Kameoka, Jun; Coté, Gerard L.
Variations in nursing care have been observed, affecting patient outcomes and quality of care. Case-based reasoners that benchmark for patient indicators can reduce variation through decision support. This study evaluated and validated a case-based reasoning application to establish benchmarks for nursing-sensitive patient outcomes of pain, fatigue, and toilet use, using patient characteristic variables for generating similar cases. Three graduate nursing students participated. Each ranked 25 patient cases using demographics of age, sex, diagnosis, and comorbidities against 10 patients from a database. Participant judgments of case similarity were compared with the case-based reasoning system. Feature weights for each indicator were adjusted to make the case-based reasoning system's similarity ranking correspond more closely to participant judgment. Small differences were noted between initial weights and weights generated from participants. For example, initial weight for comorbidities was 0.35, whereas weights generated by participants for pain, fatigue, and toilet use were 0.49, 0.42, and 0.48, respectively. For the same outcomes, the initial weight for sex was 0.15, but weights generated by the participants were 0.025, 0.002, and 0.000, respectively. Refinement of the case-based reasoning tool established valid benchmarks for patient outcomes in relation to participants and assisted in point-of-care decision making. PMID:20571376
DI Pietro, Tammie L; Doran, Diane M; McArthur, Gregory
We demonstrate an approach for detection, identification, and kinetic monitoring of drugs flowing within tubing, through the use of a plasmonic nanodome array (PNA) surface. The PNA structures are fabricated using a low-cost nanoreplica molding process upon a flexible plastic substrate that is subsequently integrated with a flow cell that connects in series with ordinary intravenous (IV) drug delivery tubing. To investigate the potential clinical applications for point-of-care detection and real-time monitoring, we perform SERS detection of ten pharmaceutical compounds (hydrocodone, levorphanol, morphine, oxycodone, methadone, phenobarbital, dopamine, diltiazem, promethazine, and mitoxantrone). We demonstrate dose-dependent SERS signal magnitude, resulting in detection limits (ng ml(-1)) well below typical administered dosages (mg ml(-1)). Further, we show that the detected drugs are not permanently attached to the PNA surface, and thus our approach is capable of performing continuous monitoring of drug delivery as materials flow through IV tubing that is connected in series with the sensor. Finally, we demonstrate the potential co-detection of multiple drugs when they are mixed together, and show excellent reproducibility and stability of SERS measurements for periods extending at least five days. The capabilities reported here demonstrate the potential to use PNA SERS surfaces for enhancing the safety of IV drug delivery. PMID:24699532
Wu, Hsin-Yu; Cunningham, Brian T
Titanium (Ti) is commonly utilized in many cardiovascular devices, e.g. as a component of Nitinol stents, intra- and extracorporeal mechanical circulatory assist devices, but is associated with the risk of thromboemboli formation. We propose to solve this problem by lining the Ti blood-contacting surfaces with autologous peripheral blood-derived late outgrowth endothelial progenitor cells (EPCs) after having previously demonstrated that these EPCs adhere to and grow on Ti under physiological shear stresses and functionally adapt to their environment under flow conditions ex vivo. Autologous fluorescently-labeled porcine EPCs were seeded at the point-of-care in the operating room onto Ti tubes for 30 minutes and implanted into the pro-thrombotic environment of the inferior vena cava of swine (n = 8). After 3 days, Ti tubes were explanted, disassembled, and the blood-contacting surface was imaged. A blinded analysis found all 4 cell-seeded implants to be free of clot, whereas 4 controls without EPCs were either entirely occluded or partially thrombosed. Pre-labeled EPCs had spread and were present on all 4 cell-seeded implants while no endothelial cells were observed on control implants. These results suggest that late outgrowth autologous EPCs represent a promising source of lining Ti implants to reduce thrombosis in vivo. PMID:21840592
Jantzen, Alexandra E.; Lane, Whitney O.; Gage, Shawn M.; Jamiolkowski, Ryan M.; Haseltine, Justin M.; Galinat, Lauren J.; Lin, Fu-Hsiung; Lawson, Jeffrey H.; Truskey, George A.; Achneck, Hardean E.
1. With histamine used as agonist, pKB values were estimated for seventeen histamine H2-receptor antagonists on assays involving acid secretion by the mouse isolated stomach and contraction frequency of the guinea-pig right atrium. 2. With the exception of oxmetidine, SK&F 94,826 and SK&F 94,206 on the right atrium assay, the compounds behaved as simple competitive antagonists on both assays. Although the former three compounds produced concentration-dependent, parallel, displacement of the histamine concentration-effect curves, subsequent analysis indicated Schild plot slope parameters significantly less than unity. However, the application of a combined dose-ratio analysis indicated that their antagonistic behaviour did not differ from expectations for simple competition at dose-ratios of approximately 20, and pKB values were estimated on this basis. 3. In accordance with previously reported data, pKB values were found to be consistently lower on the stomach than atrial assays. The pKB value for tiotidine was underestimated to the same extent on the stomach assay when impromidine was used as agonist. 4. The removal of the serosal muscle from the mouse stomach, achieved by using an isolated, perfused, mucosal sheet preparation, did not significantly affect the underestimation of the pKB value for metiamide. 5. Linear regressional analysis indicated a significant, positive, correlation between lipophilicity (log POCT/H2O) of the antagonists and the degree of antagonist pKB value underestimation on the gastric secretion assay. PMID:2900037
Shankley, N. P.; Black, J. W.; Ganellin, C. R.; Mitchell, R. C.
Breath gas analysis is a novel powerful technique for noninvasive, early-stage diagnosis of metabolic disorders or diseases. Molecular hydrogen and methane are biomarkers for colonic fermentation, because of malabsorption of oligosaccharides (e.g., lactose or fructose) and for small intestinal bacterial overgrowth. Recently, the presence of these gases in exhaled breath was also correlated with obesity. Here, we report on the highly selective and sensitive detection of molecular hydrogen and methane within a complex gas mixture (consisting of H2, CH4, N2, O2, and CO2) by means of fiber-enhanced Raman spectroscopy (FERS). An elaborate FERS setup with a microstructured hollow core photonic crystal fiber (HCPCF) provided a highly improved analytical sensitivity. The simultaneous monitoring of H2 with all other gases was achieved by a combination of rotational (H2) and vibrational (other gases) Raman spectroscopy within the limited spectral transmission range of the HCPCF. The HCPCF was combined with an adjustable image-plane aperture pinhole, in order to separate the H2 rotational Raman bands from the silica background signal and improve the sensitivity down to a limit of detection (LOD) of 4.7 ppm (for only 26 fmol H2). The ability to monitor the levels of H2 and CH4 in a positive hydrogen breath test (HBT) was demonstrated. The FERS sensor possesses a high dynamic range (?5 orders of magnitude) with a fast response time of few seconds and provides great potential for miniaturization. We foresee that this technique will pave the way for fast, noninvasive, and painless point-of-care diagnosis of metabolic diseases in exhaled human breath. PMID:25545503
Hanf, Stefan; Bögözi, Timea; Keiner, Robert; Frosch, Torsten; Popp, Jürgen
We demonstrate an approach for detection, identification, and kinetic monitoring of drugs flowing within tubing, through the use of a plasmonic nanodome array (PNA) surface. The PNA structures are fabricated using a low-cost nanoreplica molding process upon a flexible plastic substrate that is subsequently integrated with a flow cell that connects in series with ordinary intravenous (IV) drug delivery tubing. To investigate the potential clinical applications for point-of-care detection and real-time monitoring, we perform SERS detection of ten pharmaceutical compounds (hydrocodone, levorphanol, morphine, oxycodone, methadone, phenobarbital, dopamine, diltiazem, promethazine, and mitoxantrone). We demonstrate dose-dependent SERS signal magnitude, resulting in detection limits (ng ml-1) well below typical administered dosages (mg ml-1). Further, we show that the detected drugs are not permanently attached to the PNA surface, and thus our approach is capable of performing continuous monitoring of drug delivery as materials flow through IV tubing that is connected in series with the sensor. Finally, we demonstrate the potential co-detection of multiple drugs when they are mixed together, and show excellent reproducibility and stability of SERS measurements for periods extending at least five days. The capabilities reported here demonstrate the potential to use PNA SERS surfaces for enhancing the safety of IV drug delivery.We demonstrate an approach for detection, identification, and kinetic monitoring of drugs flowing within tubing, through the use of a plasmonic nanodome array (PNA) surface. The PNA structures are fabricated using a low-cost nanoreplica molding process upon a flexible plastic substrate that is subsequently integrated with a flow cell that connects in series with ordinary intravenous (IV) drug delivery tubing. To investigate the potential clinical applications for point-of-care detection and real-time monitoring, we perform SERS detection of ten pharmaceutical compounds (hydrocodone, levorphanol, morphine, oxycodone, methadone, phenobarbital, dopamine, diltiazem, promethazine, and mitoxantrone). We demonstrate dose-dependent SERS signal magnitude, resulting in detection limits (ng ml-1) well below typical administered dosages (mg ml-1). Further, we show that the detected drugs are not permanently attached to the PNA surface, and thus our approach is capable of performing continuous monitoring of drug delivery as materials flow through IV tubing that is connected in series with the sensor. Finally, we demonstrate the potential co-detection of multiple drugs when they are mixed together, and show excellent reproducibility and stability of SERS measurements for periods extending at least five days. The capabilities reported here demonstrate the potential to use PNA SERS surfaces for enhancing the safety of IV drug delivery. Electronic supplementary information (ESI) available: Fabrication of PNA substrates, fabrication details of the flow cell, details of FDTD simulation, characterization of the scattering volume, and detection of diltiazem diluted in DI water and PBS. See DOI: 10.1039/c4nr00027g
Wu, Hsin-Yu; Cunningham, Brian T.
Contrast-induced nephropathy (CIN) is a common event in hospitals, with reported incidences ranging from 1 to 30%. Patients with underlying kidney disease have an increased risk of developing CIN. Point-of-care (POC) creatinine devices are handheld devices capable of providing quantitative data on a patient's kidney function that could be useful in stratifying preventive measures. This overview aims to synthesize the current evidence on diagnostic accuracy and clinical utility of POC creatinine devices in detecting patients at risk of CIN. Five databases were searched for diagnostic accuracy studies or clinical trials that evaluated the usefulness of POC devices in detecting patients at risk of CIN. Selected articles were critically appraised to assess their individual risk of bias by the use of standard criteria; 13 studies were found that addressed the diagnostic accuracy or clinical utility of POC creatinine devices. Most studies incurred a moderate to high risk of bias. Overall concordance between POC devices and reference standards (clinical laboratory procedures) was found to be moderate, with 95% limits of agreement often lying between -35.4 and +35.4?µmol/L (-0.4 and +0.4?mg/dL). Concordance was shown to decrease with worsening kidney function. Data on the clinical utility of these devices were limited, but a significant reduction in time to diagnosis was reported in two studies. Overall, POC creatinine devices showed a moderate concordance with standard clinical laboratory creatinine measurements. Several biases could have induced optimism in these estimations. Results obtained from these devices may be unreliable in cases of severe kidney failure. Randomized trials are needed to address the clinical utility of these devices. PMID:25033794
Martínez Lomakin, Felipe; Tobar, Catalina
Point-of-care (POC) diagnostic platforms have the potential to enable low-cost, large-scale screening. As no single biomarker is shed by all ovarian cancers, multiplexed biomarker panels promise improved sensitivity and specificity to address the unmet need for early detection of ovarian cancer. We have configured the programmable bio-nano-chip (p-BNC)-a multiplexable, microfluidic, modular platform-to quantify a novel multi-marker panel comprising CA125, HE4, MMP-7, and CA72-4. The p-BNC is a bead-based immunoanalyzer system with a credit-card-sized footprint that integrates automated sample metering, bubble and debris removal, reagent storage and waste disposal, permitting POC analysis. Multiplexed p-BNC immunoassays demonstrated high specificity, low cross-reactivity, low limits of detection suitable for early detection, and a short analysis time of 43 minutes. Day-to-day variability, a critical factor for longitudinally monitoring biomarkers, ranged between 5.4% and 10.5%, well below the biologic variation for all four markers. Biomarker concentrations for 31 late-stage sera correlated well (R(2) = 0.71 to 0.93 for various biomarkers) with values obtained on the Luminex platform. In a 31 patient cohort encompassing early- and late-stage ovarian cancers along with benign and healthy controls, the multiplexed p-BNC panel was able to distinguish cases from controls with 68.7% sensitivity at 80% specificity. Utility for longitudinal biomarker monitoring was demonstrated with prediagnostic plasma from 2 cases and 4 controls. Taken together, the p-BNC shows strong promise as a diagnostic tool for large-scale screening that takes advantage of faster results and lower costs while leveraging possible improvement in sensitivity and specificity from biomarker panels. Cancer Prev Res; 8(1); 37-48. ©2014 AACR. PMID:25388014
Shadfan, Basil H; Simmons, Archana R; Simmons, Glennon W; Ho, Andy; Wong, Jorge; Lu, Karen H; Bast, Robert C; McDevitt, John T
Background Massive bleeding and transfusion of packed red blood cells (PRBC), fresh frozen plasma (FFP) and platelets are associated with increased morbidity, mortality and costs. Patients and Methods We analysed the transfusion requirements after implementation of point-of-care (POC) coagulation management algorithms based on early, calculated, goal-directed therapy with fibrinogen concentrate and prothrombin complex concentrate (PCC) in different perioperative settings (trauma surgery, visceral and transplant surgery (VTS), cardiovascular surgery (CVS) and general and surgical intensive care medicine) at 3 different hospitals (AUVA Trauma Centre Salzburg, University Hospital Innsbruck and University Hospital Essen) in 2 different countries (Austria and Germany). Results In all institutions, the implementation of POC coagulation management algorithms was associated with a reduction in the transfusion requirements for FFP by about 90% (Salzburg 94%, Innsbruck 88% and Essen 93%). Furthermore, PRBC transfusion was reduced by 8.4–62%. The incidence of intraoperative massive transfusion (?10 U PRBC) could be more than halved in VTS and CVS (2.56 vs. 0.88%; p < 0.0001 and 2.50 vs. 1.06%; p = 0.0007, respectively). Platelet transfusion could be reduced by 21–72%, except in CVS where it increased by 115% due to a 5-fold increase in patients with dual antiplatelet therapy (2.7 vs. 13.7%; p < 0.0001). Conclusions The implementation of perioperative POC coagulation management algorithms based on early, calculated, goal-directed therapy with fibrinogen concentrate and PCC is associated with a reduction in the transfusion requirements for FFP, PRBC and platelets as well as with a reduced incidence of massive transfusion. Thus, the limited blood resources can be used more efficiently. PMID:22670128
Görlinger, Klaus; Fries, Dietmar; Dirkmann, Daniel; Weber, Christian F.; Hanke, Alexander A.; Schöchl, Herbert
Background: Facilitation is considered a way of enabling clinicians to implement evidence into practice by problem solving and providing support. Practice development is a well-established movement in the United Kingdom that incorporates the use of facilitators, but in Canada, the role is more obtuse. Few investigations have observed the process of facilitation as described by individuals experienced in guideline implementation in North America. AimTo describe the tacit knowledge regarding facilitation embedded in the experiences of nurses implementing evidence into practice. Methods: Twenty nurses from across Canada were purposively selected to attend an interactive knowledge translation symposium to examine what has worked and what has not in implementing evidence in practice. This study is an additional in-depth analysis of data collected at the symposium that focuses on facilitation as an intervention to enhance evidence uptake. Critical incident technique was used to elicit examples to examine the nurses’ facilitation experiences. Participants shared their experiences with one another and completed initial data analysis and coding collaboratively. The data were further thematically analyzed using the qualitative inductive approach of constant comparison. Results: A number of factors emerged at various levels associated with the successes and failures of participants’ efforts to facilitate evidence-based practice. Successful implementation related to: (a) focus on a priority issue, (b) relevant evidence, (c) development of strategic partnerships, (d) the use of multiple strategies to effect change, and (e) facilitator characteristics and approach. Negative factors influencing the process were: (a) poor engagement or ownership, (b) resource deficits, (c) conflict, (d) contextual issues, and (e) lack of evaluation and sustainability. Conclusions: Factors at the individual, environmental, organizational, and cultural level influence facilitation of evidence-based practice in real situations at the point-of-care. With a greater understanding of factors contributing to successful or unsuccessful facilitation, future research should focus on analyzing facilitation interventions tailored to address barriers and enhance facilitators of evidence uptake. PMID:23796066
Dogherty, Elizabeth J; Harrison, Margaret B; Graham, Ian D; Vandyk, Amanda Digel; Keeping-Burke, Lisa
Background Glycemic control in critically ill patients decreases infection and mortality. While capillary blood glucose values are accurate in normotensive patients and correlate with arterial samples, patients on vasopressors have altered peripheral perfusion that may affect accuracy of capillary blood glucose values tested using point of care devices. Objectives To compare capillary and arterial blood samples using point of care testing (POCT) with arterial blood samples using the clinical chemistry lab in patients following cardiothoracic surgery, and to determine if vasopressor medications or diminished peripheral perfusion influenced the accuracy of POCT values. Methods In a prospective, convenience sample (n=50) of adult post-operative cardiothoracic patients on insulin and vasopressors, samples (n=162) were obtained simultaneously from capillary and arterial sites during insulin infusion and tested on both POCT and clinical chemistry lab, respectively. Quality of peripheral perfusion was recorded using a standardized scale. Clarke error grid analysis and ISO 15197 were used to analyze the level of agreement between the three samples. Two-way ANOVA was used to analyze differences in blood glucose values with respect to vasopressor use and peripheral perfusion. Results An unacceptable level of agreement was found between the capillary POCT and arterial samples tested in the clinical chemistry lab (only 88.3% of values fell in Zone A, or within the ISO 15197 tolerance bands). Arterial POCT showed 94.4% agreement with the clinical chemistry lab. Vasopressor use demonstrated a statistically significant effect on the accuracy of arterial blood glucose values (F=15.01; p= .0001). Conclusions Capillary POCT is not within acceptable limits of agreement with the clinical chemistry lab. Even when using the more accurate arterial blood with POCT, patients with >2 vasopressors demonstrate significantly less accuracy as compared to patients on fewer vasopressors. Using the clinical chemistry lab may be safer for insulin titration in these patients. PMID:23996422
Ellis, Myra F.; Benjamin, Kesi; Cornell, Morgan; Decker, Kelsey; Farrell, Debra; McGugan, Lynn; Porter, Gloria P.; Shearin, Helen; Zhao, Yanfang; Granger, Bradi B
This pilot study evaluates the diagnostic performance of Sofia RSV Fluorescent Immunoassay Analyzer (FIA) and Sofia Influenza A + B FIA for rapid detection of respiratory syncytial virus and influenza A and B. Sofia had a lower-than-expected sensitivity for all viruses and a high rate of false-positive results for influenza B virus. PMID:25241640
Bruning, Andrea H L; van Dijk, Karin; van Eijk, Hetty W M; Koen, Gerrit; van Woensel, Job B M; Kruisinga, Frea H; Pajkrt, Dasja; Wolthers, Katja C
Background Although echocardiography is an important tool for making the diagnosis of left ventricular (LV) dysfunction, the cost of this procedure limits its use as a routine screening tool for this purpose. Brain natriuretic peptide (BNP) accurately reflects ventricular pressure, and preliminary studies have found it to be highly sensitive and highly specific in diagnosing congestive heart failure in the
Alan S. Maisel; Jen Koon; Padma Krishnaswamy; Radmila Kazenegra; Paul Clopton; Nancy Gardetto; Robin Morrisey; Alex Garcia; Albert Chiu; Anthony De Maria
It is clinically important to be able to detect influenza A/H1N1 virus using a fast, portable, and accurate system that has high specificity and sensitivity. To achieve this goal, it is necessary to develop a highly specific primer set that recognizes only influenza A viral genes and a rapid real-time PCR system that can detect even a single copy of the viral gene. In this study, we developed and validated a novel fluidic chip-type real-time PCR (LabChip real-time PCR) system that is sensitive and specific for the detection of influenza A/H1N1, including the pandemic influenza strain A/H1N1 of 2009. This LabChip real-time PCR system has several remarkable features: (1) It allows rapid quantitative analysis, requiring only 15 min to perform 30 cycles of real-time PCR. (2) It is portable, with a weight of only 5.5 kg. (3) The reaction cost is low, since it uses disposable plastic chips. (4) Its high efficiency is equivalent to that of commercially available tube-type real-time PCR systems. The developed disposable LabChip is an economic, heat-transferable, light-transparent, and easy-to-fabricate polymeric chip compared to conventional silicon- or glass-based labchip. In addition, our LabChip has large surface-to-volume ratios in micro channels that are required for overcoming time consumed for temperature control during real-time PCR. The efficiency of the LabChip real-time PCR system was confirmed using novel primer sets specifically targeted to the hemagglutinin (HA) gene of influenza A/H1N1 and clinical specimens. Eighty-five human clinical swab samples were tested using the LabChip real-time PCR. The results demonstrated 100% sensitivity and specificity, showing 72 positive and 13 negative cases. These results were identical to those from a tube-type real-time PCR system. This indicates that the novel LabChip real-time PCR may be an ultra-fast, quantitative, point-of-care-potential diagnostic tool for influenza A/H1N1 with a high sensitivity and specificity. PMID:23285281
Song, Hyun-Ok; Kim, Je-Hyoung; Ryu, Ho-Sun; Lee, Dong-Hoon; Kim, Sun-Jin; Kim, Deog-Joong; Suh, In Bum; Choi, Du Young; In, Kwang-Ho; Kim, Sung-Woo; Park, Hyun
Will a quadruple multiplexed point-of-care screening strategy for HIV-related co-infections be feasible and impact detection of new co-infections in at-risk populations? Results from cross-sectional studies
Objectives Multiplexed point-of-care (POC) devices can rapidly screen for HIV-related co-infections (eg, hepatitis C (HCV), hepatitis B (HBV), syphilis) in one patient visit, but global evidence for this approach remains limited. This study aimed to evaluate a multiplex POC testing strategy to expedite screening for HIV-related co-infections in at-risk populations. Methods A multiplex strategy was developed with two subsequent versions of an investigational device Miriad. It was evaluated in two non-comparable settings and populations in two countries for feasibility of conduct, detection of new infections, preference and accuracy. Version 1 was evaluated in 375 sexually transmitted disease clinic attendees in Mumbai, India; version 2 was evaluated in 119 injection drug users in Montreal, Canada. Results Feasibility (completion rate) of the multiplex strategy was high (86.1% Mumbai; 92.4% Montreal). A total of 170 new infections were detected in Mumbai (56 HIV, 75 HBV, 37 syphilis, 2 HCV) versus 2 in Montreal. Preference was 60% in Mumbai and 97% in Montreal. Miriad version 1 specificities were high: HIV 99.7% (98.3% to 100%), HBV 99.3% (97.6% to 99.9%), HCV 99.7% (98.5% to 99.9%), syphilis 85.2% (80.9% to 88.8%); sensitivities were as follows: HIV 100% (94.8% to 100%), HBV 13.3% (6.6% to 23.2%), HCV 50% (1.3% to 98.7%), syphilis 86.1% (70.5% to 95.3%). With version 2, specificities improved: HIV 100% (97.2% to 100%), HBV 100% (97.3% to 100%), HCV 85.3% (73.8% to 93.0%), syphilis 98.1% (93.3% to 99.8%); sensitivities were: HIV 100% (47.3% to 100%), HCV 80.4% (66.1% to 90.6%), syphilis 100% (22.4% to 100%). Conclusions A quad multiplex POC strategy for HIV and co-infections was feasible to operationalise and preferred by patients in both settings. Many new infections were identified in Mumbai and accuracy improved with version 2 of the assay. Such a strategy will help expedite screening for co-infections, particularly where baseline screening is low. These findings are valuable to practitioners, researchers, policymakers and funders involved in initiatives for all four diseases with implications for scale-up. PMID:25510882
Pai, Nitika Pant; Dhurat, Rachita; Potter, Martin; Behlim, Tarannum; Landry, Geneviève; Vadnais, Caroline; Rodrigues, Camilla; Joseph, Lawrence; Shetty, Anjali
This paper briefly overviews progress on the development of MEMS-based micropumps and their applications in drug delivery and other biomedical applications such as micrototal analysis systems (?TAS) or lab-on-a-chip and point of care testing systems (POCT). The focus of the review is to present key features of micropumps such as actuation methods, working principles, construction, fabrication methods, performance parameters and
A. Nisar; Nitin Afzulpurkar; Banchong Mahaisavariya; Adisorn Tuantranont
In recent years, the use of transoesophageal echocardiography has increased in anaesthesia and intensive care. We explored the impact of two different teaching methods on the ability of echocardiography-naïve subjects to identify cardiac anatomy associated with the 20 standard transoesophageal echocardiography imaging planes, and assessed trainees' satisfaction with these methods of training. Fifty-two subjects were randomly assigned to one of two groups: a simulation-based and a theatre-based teaching group. Subjects undertook video-based tests comprised of 20 multiple choice questions on echocardiography views before and after receiving echocardiography teaching. Subjects in simulation- and theatre-based teaching groups scored 40% (30-40 [20-50])% and 35% (30-40 [15-55])% in the pre-test, respectively (p = 0.52). Following echocardiography teaching, subjects within both groups improved upon their pre-test knowledge (p < 0.001). Subjects in the simulation-based teaching group significantly outperformed their theatre-based group counterparts in the post-intervention test (p = 0.0002). PMID:25308195
Ogilvie, E; Vlachou, A; Edsell, M; Fletcher, S N; Valencia, O; Meineri, M; Sharma, V
Background Monitoring of immune function, measured by CD4 cell count, is an essential service for people with Human Immunodeficiency Virus (HIV). Prescription of antiretroviral (ARV) medications is contingent on CD4 cell count; patients without regular CD4 monitoring are unlikely to receive ARVs when indicated. This study assesses disparities in CD4 monitoring among HIV-positive Medicaid beneficiaries. Methods In this retrospective observational study, we examined 24 months of administrative data on 2,250 HIV-positive, continuously-enrolled fee-for-service Medicaid beneficiaries with at least two outpatient healthcare encounters. We used logistic regression to evaluate the association of patient demographics (age, gender, race/ethnicity, and language) with receipt of at least one CD4 test per year, controlling for other potentially confounding variables. Results Having a history of ARV therapy was positively associated with receipt of CD4 tests. We found racial/ethnic, gender, and age disparities in CD4 testing. Among individuals with a history of ARV use, all racial/ethnic groups were significantly less likely to have CD4 tests than White non-Latinos (African Americans, OR = 0.35, p<0.0001; Asian/Pacific Islanders, OR = 0.31, p=0.0047; and, Latinos, OR = 0.42, p<0.0001). Conclusions Disparities in receipt of CD4 tests elucidate one potential pathway for previously reported disparities in ARV treatment. Further qualitative and quantitative research is needed to identify the specific factors that account for these disparities, so that appropriate interventions can be implemented. PMID:25401120
Davis, Anna C.; Watson, Greg; Pourat, Nadereh; Kominski, Gerald F.; Roby, Dylan H.
AIM: To evaluate the effectiveness of a rapid and easy fingertip whole blood point-of-care test for celiac disease (CD) case finding and diet monitoring. METHODS: Three hundred individuals, 206 females (68.7%) and 94 males (31.3%), were submitted to a rapid and easy immunoglobulin-A-class fingertip whole blood point-of-care test in the doctor's office in order to make immediate clinical decisions: 13
Lorete Maria da Silva; Luiz Roberto Kotze; Renato Mitsunori Nisihara; Kotze LM; Brambila Rodrigues AP; Kotze LR; Nisihara RM
Background Routine HIV screening in emergency department (ED) settings may require dedicated personnel. We evaluated the outcomes, costs and cost-effectiveness of HIV screening when offered by either a member of the ED staff or by an HIV counselor. Methods We employed a mathematical model to extend data obtained from a randomized clinical trial of provider- vs. counselor-based HIV screening in the ED. We compared the downstream survival, costs, and cost-effectiveness of three HIV screening modalities: 1) no screening program; 2) an ED provider-based program; and 3) an HIV counselor-based program. Trial arm-specific data were used for test offer and acceptance rates (provider offer 36%, acceptance 75%; counselor offer 80%, acceptance 71%). Undiagnosed HIV prevalence (0.4%) and linkage to care rates (80%) were assumed to be equal between the screening modalities. Personnel costs were derived from trial-based resource utilization data. We examined the generalizability of results by conducting sensitivity analyses on offer and acceptance rates, undetected HIV prevalence, and costs. Results Estimated HIV screening costs in the provider and counselor arms averaged $8.10 and $31.00 per result received. The Provider strategy (compared to no screening) had an incremental cost-effectiveness ratio of $58,700/quality-adjusted life year (QALY) and the Counselor strategy (compared to the Provider strategy) had an incremental cost-effectiveness ratio of $64,500/QALY. Results were sensitive to the relative offer and acceptance rates by strategy and the capacity of providers to target-screen, but were robust to changes in undiagnosed HIV prevalence and programmatic costs. Conclusions The cost-effectiveness of provider-based HIV screening in an emergency department setting compares favorably to other US screening programs. Despite its additional cost, counselor-based screening delivers just as much return on investment as provider based-screening. Investment in dedicated HIV screening personnel is justified in situations where ED staff resources may be insufficient to provide comprehensive, sustainable screening services. PMID:22022415
Walensky, Rochelle P.; Morris, Bethany L.; Reichmann, William M.; Paltiel, A. David; Arbelaez, Christian; Donnell-Fink, Laurel; Katz, Jeffrey N.; Losina, Elena
The article by Vohra and colleagues, "Sonographic Signs of Snakebites", is reviewed and offers a novel use of ultrasound to assess the severity of soft tissue injury due to crotaline envenomation. The authors have shown the feasibility and potential utility of this modality. Further studies are needed to determine the true value of these sonographic findings and how to apply them to patient care. PMID:25345434
Ockerse, P; Mallin, M
supplies. Inadequate environmental monitoring capabilities were highlighted by the cholera epidemic in Haiti after the earthquake in 2010 [20–24]. Although the cholera epidemic took most people by surprise, it wasn’t totally unexpected since Haiti ranked...
Yetisen, Ali Kemal
In recent years, thanks to the development of miniaturized ultrasound devices, comparable to personal computers, tablets and even to smart phones, we have seen an increasing use of bedside ultrasound in internal medicine departments as a novel kind of ultrasound stethoscope. The clinical ultrasound-assisted approach has proved to be particularly useful in assessing patients with nodules of the neck, dyspnoea, abdominal pain, and with limb edema. In several cases, it has allowed a simple, rapid and precise diagnosis. Since 2005, the Italian Society of Internal Medicine and its Ultrasound Study Group has been holding a Summer School and training courses in ultrasound for residents in internal medicine. A national network of schools in bedside ultrasound was then organized for internal medicine specialists who want to learn this technique. Because bedside ultrasound is a user-dependent diagnostic method, it is important to define the limits and advantages of different new ultrasound devices, to classify them (i.e. Echoscopy and Point of Care Ultrasound), to establish appropriate different levels of competence and to ensure their specific training. In this review, we describe the point of view of the Italian Internal Medicine Society on these topics. PMID:25145290
Arienti, Vincenzo; Di Giulio, Rosella; Cogliati, Chiara; Accogli, Esterita; Aluigi, Leonardo; Corazza, Gino Roberto
Dependability is an important attribute for microfluidic biochips that are used for safety-critical applications such as point-of-care health assessment, air-quality monitoring, and food-safety testing. Therefore, these devices must be adequately tested after manufacture and during bioassay operations. Known techniques for biochip testing are all function-oblivious, i.e., while they can detect and locate defect sites on a microfluidic array, they cannot
Tao Xu; Krishnendu Chakrabarty
A simple and sensitive point-of-care-test (POCT) device for chemiluminescence (CL) immunoassay was devised and tested. The device consists of a plastic flow-channel reactor and two wireless-communication sensor chips, namely, a photo-sensor chip and a temperature-sensor chip. In the flow-channel reactor, a target antigen is captured by an antibody immobilized on the inner wall of the flow-channel and detected with enzyme labeled antibody by using CL substrate. The CL signal corresponding to the amount of antigen is measured by a newly developed radio-frequency-identification (RFID) sensor, which enables batteryless operation and wireless data communication with an external reader. As for the POCT device, its usage environment, especially temperature, varies for each measurement. Hence, temperature compensation is a key issue in regard to eliminating dark-signal fluctuation, which is a major factor in deterioration of the precision of the POCT device. A two-stage temperature-compensation scheme was adopted. As for the first stage, the signals of two photodiodes, one with an open window and one with a sealed window, integrated on the photo-sensor chip are differentiated to delete the dark signal. As for the second stage, the differentiated signal fluctuation caused by a temperature variation is compensated by using the other sensor chip (equipped with a temperature sensor). The dark-level fluctuation caused by temperature was reduced from 0.24 to 0.02 pA/°C. The POCT device was evaluated as a CL immunoassay of thyroid-stimulating hormone (TSH). The flow rate of the CL reagent in the flow channel was optimized. As a result, the detection limit of the POCT device was 0.08 ng/ml (i.e., 0.4 ?IU/ml). PMID:24735652
Yazawa, Yoshiaki; Oonishi, Tadashi; Watanabe, Kazuki; Shiratori, Akiko; Funaoka, Sohei; Fukushima, Masao
Clinical laboratories provide an invaluable service to millions of people around the world in the form of quality diagnostic care. Within the clinical laboratory industry the impetus for change has come from technological development (miniaturization, nanotechnology, and their collective effect on point-of-care testing; POCT) and the increasingly global nature of laboratory services. Potential technological gains in POCT include: the development of bio-sensors, microarrays, genetics and proteomics testing, and enhanced web connectivity. In globalization, prospective opportunities lie in: medical tourism, the migration of healthcare workers, cross-border delivery of testing, and the establishment of accredited laboratories in previously unexplored markets. Accompanying these impressive opportunities are equally imposing challenges. Difficulty transitioning from research to clinical use, poor infrastructure in developing countries, cultural differences and national barriers to global trade are only a few examples. Dealing with the issues presented by globalization and the impact of developing technology on POCT, and on the clinical laboratory services industry in general, will be a daunting task. Despite such concerns, with appropriate countermeasures it will be possible to address the challenges posed. Future laboratory success will be largely dependent on one's ability to adapt in this perpetually shifting landscape. PMID:21175379
Melo, Murilo R; Clark, Samantha; Barrio, Daniel
With the continuing rise of multiresistant pathogens, reliable, cost-effective, and novel diagnostics are urgently required by clinicians and clinical trialists to diagnose conditions such as respiratory tract infections to enable rational antimicrobial choice and enhance clinical outcomes. However, during product development, validation of these in vitro diagnostic devices, a key regulatory hurdle, requires sputum samples in large numbers. The Rapid Point-of-Care test Platform for Infectious Diseases (RAPP-ID) consortium is tasked with producing point of care test (POCT) platforms for rapid diagnosis of lower respiratory tract infections, including tuberculosis and blood stream infections. Validation of diagnostic platforms would ideally use well-characterized samples in a sputum library taken from a range of clinical settings to allow for a wide panel of pathogens to be assessed. These samples would be stored in specific stable conditions (monitored temperature, specific medium) until required for validation. Therefore we reviewed the current literature for details of storage conditions of sputum samples and for previous validation studies of other diagnostic tests using this methodology. However, we conclude that little data exists, and thus the acquisition and successful storage of good quality clinical samples are major roadblocks in the validation of novel POCT platforms, and that while not without limitations, spiked sputum samples appear the best solution until sputum library laboratory techniques allowing careful preservation of pathogens are improved. PMID:24489460
Dollow, Joshua M; Green, Justin A
Dependability is an important attribute for microfluidic biochips that are used for safety-critical applications such as point-of-care health assessment, air-quality monitoring, and food-safety testing. Therefore, these devices must be adequately tested after manufacture and during bioassay operations. We propose a parallel scan-like testing methodology for digital microfluidic devices. A diagnosis method based on test outcomes is also proposed. The diagnosis
Tao Xu; Krishnendu Chakrabarty
Interpreting tricyclic antidepressant measurements in urine in an emergency department setting: comparison of two qualitative point-of-care urine tricyclic antidepressant drug immunoassays with quantitative serum chromatographic analysis.
Patients taking tricyclic antidepressants (TCA) can experience toxicity or severe side effects. As a rapid and less technically demanding alternative to quantitative serum analysis, most laboratories offer qualitative immunoassays to assist in the evaluation of a suspected TCA overdose. However, the relationship between quantitative serum and qualitative urine levels of TCA-related compounds and their metabolites has not been comprehensively studied. Serum high-performance liquid chromatography results were compared to the qualitative urine results using the Syva Rapid Test and the Biosite Triage. Serum concentrations of amitriptyline, desipramine, doxepin, imipramine, and nortriptyline ranging from subtherapeutic to toxic triggered a positive response on both urine immunoassay devices. On the other hand, neither immunoassay uniformly detected clomipramine, even at serum levels greater than the therapeutic range. False positives due to cyclobenzaprine were more common with the Biosite assay. For virtually all positive urine TCA findings, it was not possible to determine whether the positive results corresponded to subtherapeutic, therapeutic, supratherapeutic, or toxic serum concentrations. Because urine immunoassays are the only option for many laboratories analyzing specimens for TCAs (especially in an emergency setting), clinicians must understand the limitations and interpret results in conjunction with clinical findings and/or quantitation of serum levels. PMID:17579971
Melanson, Stacy E F; Lewandrowski, Elizabeth Lee; Griggs, David A; Flood, James G
The paper presents the development of a “proof-of-principle” hands-free and self-contained diagnostic platform for detection of human papillomavirus (HPV) E6/E7 mRNA in clinical specimens. The automated platform performs chip-based sample preconcentration, nucleic acid extraction, amplification, and real-time fluorescent detection with minimal user interfacing. It consists of two modular prototypes, one for sample preparation and one for amplification and detection; however, a common interface is available to facilitate later integration into one single module. Nucleic acid extracts (n = 28) from cervical cytology specimens extracted on the sample preparation chip were tested using the PreTect HPV-Proofer and achieved an overall detection rate for HPV across all dilutions of 50%–85.7%. A subset of 6 clinical samples extracted on the sample preparation chip module was chosen for complete validation on the NASBA chip module. For 4 of the samples, a 100% amplification for HPV 16 or 33 was obtained at the 1?:?10 dilution for microfluidic channels that filled correctly. The modules of a “sample-in, answer-out” diagnostic platform have been demonstrated from clinical sample input through sample preparation, amplification and final detection. PMID:22235204
Gulliksen, Anja; Keegan, Helen; Martin, Cara; O'Leary, John; Solli, Lars A.; Falang, Inger Marie; Grønn, Petter; Karlgård, Aina; Mielnik, Michal M.; Johansen, Ib-Rune; Tofteberg, Terje R.; Baier, Tobias; Gransee, Rainer; Drese, Klaus; Hansen-Hagge, Thomas; Riegger, Lutz; Koltay, Peter; Zengerle, Roland; Karlsen, Frank; Ausen, Dag; Furuberg, Liv
This hour-long video from the University of WashingtonÃ¢ÂÂs Molecular Medicine Training Program explains microfluidicsÃ¢ÂÂa technology for manipulating small volumes of fluid that could have a major impact on global health by enabling the development of a portable and inexpensive system for detecting pathogens.
Nancy Maizels (University of Washington;University of Washington Molecular Medicine Trainging program)
The University of Washington's "UWTV" website is an archive of talks by visitors to the University as well as professors, librarians, and others who have a formal association with the institution. The talks cover a myriad of topics from urban planning to zoology, and this specific talk looks into the world of health care provisioning in the developing world. The talk is by Professor Paul Yager of the bioengineering department at the UW, and he offers information and findings about a new technology for manipulating small volumes of fluids. This technology will help health care professionals as they work to create a small portable and inexpensive system for detecting pathogens far from any centralized laboratory. It's an engaging hour-long talk, and one that will be of interest to persons in the health care and public health fields.
Parent-offspring conflict theory (POCT) has been underutilized in studies of human family dynamics. An implication of POCT is that the presence of siblings will increase conflict in biological parent-child dyads, and that half siblings will increase that conflict more than full siblings. Evidence consistent with this prediction was found in a…
Schlomer, Gabriel L.; Ellis, Bruce J.; Garber, Judy
A plastic biochip was developed for the detection of procalcitonin (PCT) and consists of a polymethylmethacrylate (PMMA) chip shaped in order to achieve several flow microchannels. A sandwich assay using a new antibody pairs is implemented with the capture antibody immobilized on the PMMA surface and the target antibody labelled with a fluorophore. A laser diode excites the fluorescent sensing layer. Thanks to the anisotropy of the fluorescence the emitted light travels along the thickness of the plastic material. The fluorescence coming out from the chip is collected by 1 mm plastic optical fibre and detected with a spectrum analyser.
Baldini, Francesco; Bolzoni, Luca; Giannetti, Ambra; Kess, Melanie; Kraemer, Petra M.; Kremmer, Elisabeth; Porro, Giampiero; Senesi, Folco; Trono, Cosimo
This paper presents a discussion on Vetscan, a system designed to provide veterinarians with instant diagnostic information needed for rapid treatment decisions. VetScan is designed for point-of-care testing in any treatment setting, including mobile environments, where veterinarians can operate the analyzer from a car-lighter adapter. A full range of tests is available for almost every species normally treated by veterinarians, including cats, dogs, birds, reptiles, and large animals, such as those in the equine and bovine families.
HIV diagnostic and follow up testing are usually done in laboratory settings. However, in developing countries there is a need to decentralize testing as the majority of the population lives in rural settings. In developing countries stringent quality assurance (QA) practices, which include appropriate training, development of standard operating procedures, maintenance of operator proficiency, routine use of quality control (QC) specimens, standardized data management, equipment calibration and maintenance, and biohazard safety with proper disinfection/disposal procedures are not routinely followed to ensure reliability of results and a safe work environment. The introduction of point-of-care testing technologies involving the use of non-laboratorians in routine testing has further increased the complexity of QA. Therefore, a careful approach towards improvement of laboratories that encourages best practices, coupled with incentives, and review of government policies in point-of-care testing is needed to improve quality of testing as decentralization takes place. Development of a functional laboratory tiered network that facilitates communication, referral, training and problem solving could further enhance confidence in laboratory testing. There is also a need for special considerations in implementing a step-wise approach towards quality improvement, strengthening of the supply chain management, human capacity development, infrastructure upgrade, and strong public private partnerships to ensure long term sustainability of these efforts. PMID:22310813
Alemnji, George; Nkengasong, John N; Parekh, Bharat S
Bacillus anthracis, Brucella spp., and Yersinia pestis are zoonotic pathogens and biowarfare- or bioterrorism-associated agents that must be detected rapidly on-site from various samples (e.g., viscera and powders). An up-converting phosphor technology-based lateral flow (UPT–LF) strip was developed as a point-of-care testing (POCT) to satisfy the requirements of first-level emergency response. We developed UPT–LF POCT to quantitatively detect the three pathogens within 15 min. Sample and operation-error tolerances of the assay were comprehensively evaluated. The sensitivity of UPT–LF assay to bacterial detection reached 104 cfu·mL?1 (100 cfu/test), with a linear quantitative range of 4 to 6 orders of magnitude. Results revealed that the UPT–LF assay exhibited a high specificity with the absence of false-positive results even at 109 cfu·mL?1 of non-specific bacterial contamination. The assay could tolerate samples with a wide pH range (2 to 12), high ion strengths (?4 mol·L?1 of NaCl), high viscosities (?25 mg·mL?1 of PEG20000 or ?20% of glycerol), and high concentrations of bio-macromolecule (?200 mg·mL?1 of bovine serum albumin or ?80 mg·mL?1 of casein). The influence of various types of powders and viscera (fresh and decomposed) on the performance of UPT–LF assay was determined. The operational error of liquid measurement exhibited few effects on sensitivity and specificity. The developed UPT–LF POCT assay is applicable under field conditions with excellent tolerance to sample complexity and operational error. PMID:25144726
Zhao, Yong; Hua, Fei; Li, Chunfeng; Yang, Ruifu; Zhou, Lei
This work presents novel components for on-chip storage and dispensing inside a lab-on-a-chip (LOC) for applications in immunoassay point-of-care testing (POCT), where incubation and washing steps are essential. It involves easy-to-use on-chip solutions for the sequential thermo-hydraulic actuation of liquids. The novel concept of combining the use of a rubber plug, both as a non-return valve cap and as a liquid injection interface of a sealed reservoir, allows simple filling of a sterilized cavity, as well as the storage and dispensing of reagent and washing buffer liquids. Segmenting the flow with air spacers enables effective rinsing and the use of small volumes of on-chip stored liquids. The chip uses low-resistance resistors as heaters in the paraffin actuator, providing the low-voltage actuation that is preferred for handheld battery driven instruments.
Bodén, Roger; Lehto, Marcus; Margell, Joakim; Hjort, Klas; Schweitz, Jan-Åke
Accurate disease diagnosis in animals is crucial for animal well-being but also for preventing zoonosis transmission to humans. In particular, livestock diseases may constitute severe threats to humans due to the particularly high physical contact and exposure and, also, be the cause of important economic losses, even in non-endemic countries, where they often arise in the form of rapid and devastating epidemics. Rapid diagnostic tests have been used for a long time in field situations, particularly during outbreaks. However, they mostly rely on serological approaches, which may confirm the exposure to a particular pathogen but may be inappropriate for point-of-decision (point-of-care) settings when emergency responses supported on early and accurate diagnosis are required. Moreover, they often exhibit modest sensitivity and hence significantly depend on later result confirmation in central or reference laboratories. The impressive advances observed in recent years in materials sciences and in nanotechnology, as well as in nucleic-acid synthesis and engineering, have led to an outburst of new in-the-bench and prototype tests for nucleic-acid testing towards point-of-care diagnosis of genetic and infectious diseases. Manufacturing, commercial, regulatory, and technical nature issues for field applicability more likely have hindered their wider entrance into veterinary medicine and practice than have fundamental science gaps. This chapter begins by outlining the current situation, requirements, difficulties, and perspectives of point-of-care tests for diagnosing diseases of veterinary interest. Nucleic-acid testing, particularly for the point of care, is addressed subsequently. A range of valuable signal transduction mechanisms commonly employed in proof-of-concept schemes and techniques born on the analytical chemistry laboratories are also described. As the essential core of this chapter, sections dedicated to the principles and applications of microfluidics, lab-on-a-chip, and nanotechnology for the development of point-of-care tests are presented. Microdevices already applied or under development for application in field diagnosis of animal diseases are reviewed. PMID:25399103
Teles, Fernando; Fonseca, Luís
A new on-chip whole blood/plasma separator driven by asymmetric capillary forces, which are produced through a microchannel with sprayed nanobead multilayers, has been designed, fabricated and fully characterized. The silica nanobead multilayers revealing as superhydrophilic surfaces have been fabricated using a spray layer-by-layer (LbL) nano-assembly method. This new on-chip blood plasma separator has been targeted for a sample-to-answer (S-to-A) microfluidic lab-on-a-chip (LOC) toward point-of-care clinical testing (POCT). Effective plasma separation from undiluted whole blood was achieved through the microchannel which was composed of asymmetric superhydrophilic surfaces with a 10 mm hydrophobic patch. Blood cells were continuously accumulated over the hydrophobic patch while the blood plasma was able to flow over the patch. Therefore, the blood plasma was successfully separated from the whole blood throughout the accumulated blood cells which worked as a so-called 'self-built-in blood cell microfilter'. The separated plasma was approximately 102 nL from a single drop of 3 ?L whole blood within 10 min, which is very suitable for single-use disposable POCT devices. PMID:23793507
Lee, Kang Kug; Ahn, Chong H
Along with the miniaturization and intellectualization of biomedical instruments, the increasing demand of health monitoring at anywhere and anytime elevates the need for the development of point of care testing (POCT). Photonic crystal beads (PCBs) as one kind of good encoded microcarriers can be integrated with microfluidic chips in order to realize cost-effective and high sensitive multiplex bioassays. However, there are difficulties in analyzing them towards automated analysis due to the characters of the PCBs and the unique detection manner. In this paper, we propose a strategy to take advantage of automated image processing for the color decoding of the PCBs array in the microfluidic chip for multiplex assays. By processing and alignment of two modal images of epi-fluorescence and epi-white light, every intact bead in the image is accurately extracted and decoded by PC colors, which stand for the target species. This method, which shows high robustness and accuracy under various configurations, eliminates the high hardware requirement of spectroscopy analysis and user-interaction software, and provides adequate supports for the general automated analysis of POCT based on PCBs array. PMID:25341876
Yuan, Junjie; Zhao, Xiangwei; Wang, Xiaoxia; Gu, Zhongze
Along with the miniaturization and intellectualization of biomedical instruments, the increasing demand of health monitoring at anywhere and anytime elevates the need for the development of point of care testing (POCT). Photonic crystal beads (PCBs) as one kind of good encoded microcarriers can be integrated with microfluidic chips in order to realize cost-effective and high sensitive multiplex bioassays. However, there are difficulties in analyzing them towards automated analysis due to the characters of the PCBs and the unique detection manner. In this paper, we propose a strategy to take advantage of automated image processing for the color decoding of the PCBs array in the microfluidic chip for multiplex assays. By processing and alignment of two modal images of epi-fluorescence and epi-white light, every intact bead in the image is accurately extracted and decoded by PC colors, which stand for the target species. This method, which shows high robustness and accuracy under various configurations, eliminates the high hardware requirement of spectroscopy analysis and user-interaction software, and provides adequate supports for the general automated analysis of POCT based on PCBs array.
Yuan, Junjie; Zhao, Xiangwei; Wang, Xiaoxia; Gu, Zhongze
Along with the miniaturization and intellectualization of biomedical instruments, the increasing demand of health monitoring at anywhere and anytime elevates the need for the development of point of care testing (POCT). Photonic crystal beads (PCBs) as one kind of good encoded microcarriers can be integrated with microfluidic chips in order to realize cost-effective and high sensitive multiplex bioassays. However, there are difficulties in analyzing them towards automated analysis due to the characters of the PCBs and the unique detection manner. In this paper, we propose a strategy to take advantage of automated image processing for the color decoding of the PCBs array in the microfluidic chip for multiplex assays. By processing and alignment of two modal images of epi-fluorescence and epi-white light, every intact bead in the image is accurately extracted and decoded by PC colors, which stand for the target species. This method, which shows high robustness and accuracy under various configurations, eliminates the high hardware requirement of spectroscopy analysis and user-interaction software, and provides adequate supports for the general automated analysis of POCT based on PCBs array. PMID:25341876
Yuan, Junjie; Zhao, Xiangwei; Wang, Xiaoxia; Gu, Zhongze
Emergency Diagnostics, Homeland Security, Epidemiological Preparedness and the high cost of the Health Care Systems have increased demand for affordable and mobile point of care (POC) devices with highest sensitivity, specificity and rapid time to result. We have developed pocket sized systems for point of care and field based tests based on fluorescence read-out. The core consists of battery operated, 90 gram electro-optical units with optional wireless data transfer, which have been optimized to achieve highest accuracy and sensitivity paired with simplicity of use. The robust systems have been applied to molecular diagnostics such as DNA based testing, immunodiagnostics as well as environmental monitoring and agricultural testing. We will show examples of DNA testing, testing of drugs and toxins, cell based assays and water monitoring. We will discuss drivers and rationale for mobile testing platforms and address critical points such as sample preparation and sampling problems e.g. target delivery in small volumes. ESE's battery-operated handheld and mobile testing platforms have been shown to provide sensitive, accurate, and specific results, as well as rapid turnaround. The stand-alone devices demonstrate operational and physical robustness, and they can be manufactured to be affordable. Some underlying assays work directly from clinical samples such as urine or blood.
Faulstich, Konrad; Haberstroh, Klaus; Gruler, Roman; Eberhard, Michael; Wiest, Thomas; Lentzsch, Dirk
Point of care testing (POCT) using biomarkers in the emergency department reduces turnaround time for clinical decision making. An ideal biomarker should be accurate, reliable and easy to measure with a standard assay, non-invasive, sensitive and specific with defined cutoff values. Conventional biomarkers for renal injuries include rise in serum creatinine and fluid overload. Recently, neutrophil gelatinase associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), cystatin C, interleukin-18 (IL-18) and liver fatty acid binding protein (L-FABP) have been studied extensively for their role in acute kidney injury associated with various clinical entities. Biochemical markers of ischaemic cardiac damage commonly used are plasma creatine kinase and cardiac troponins (cTn). Clinically valuable cardiac markers for myocardial injury in research at present comprise BNP/NT-proBNP and to a lesser extent, CRP, which are independent predictors of adverse events including death and heart failure. Current status of point of care biomarkers for diagnosis and prognostication of renal and cardiac injuries in pediatric emergency care is appraised in this review. PMID:25337487
Singhal, Noopur; Saha, Abhijeet
A rapid test for an infectious disease that can be used at point-of-care at a physician's office, a pharmacy, or in the field is critical for the prompt and appropriate therapeutic intervention. Ultimately by treating infections early on will decrease transmission of the pathogen. In contrast to metabolic diseases or cancer where multiple biomarkers are required, infectious disease targets (e.g. antigen, antibody, nucleic acid) are simple and specific for the pathogen causing the disease. Our laboratory has focused on three major infectious disease; HIV, Tuberculosis, and Malaria. These diseases are pandemic in much of the world thus putting natives, tourists and military personnel at risk for becoming infected, and upon returning to the U.S., transmitting these diseases to their contacts. Our devices are designed to detect antigens, antibodies or nucleic acids in blood or saliva samples in less than 30 minutes. An overview describing the current status of each of the three diagnostic platforms is presented. These microfluidic point-of-care devices will be relatively inexpensive, disposable, and user friendly.
Articles in this special section consider (1) flow in test taking (Craig Deville); (2) testwiseness (Thomas O'Neill); (3) test length (Benjamin Wright); (4) cross-language test equating (Richard W. Woodcock and Ana Munoz-Sandoval); (5) computer-assisted testing and testwiseness (Richard Gershon and Betty Bergstrom); and (6) Web-enhanced testing…
Deville, Craig; O'Neill, Thomas; Wright, Benjamin D.; Woodcock, Richard W.; Munoz-Sandoval, Ana; Gershon, Richard C.; Bergstrom, Betty
The number and use of pharmacogenetic tests to assess a patient's likelihood of response or risk of an adverse event is expanding across medical specialties and becoming more prevalent. During this period of development and translation, different approaches are being investigated to optimize delivery of pharmacogenetic services. In this paper, we review pre-emptive and point-of-care delivery approaches currently implemented or being investigated and discuss the advantages and disadvantages of each approach. The continued growth in knowledge about the genetic basis of drug response combined with development of new and less expensive testing technologies and electronic medical records will impact future delivery systems. Regardless of delivery approach, the currently limited knowledge of health professionals about genetics generally or PGx specifically will remain a major obstacle to utilization. PMID:24384556
Haga, Susanne B; Moaddeb, Jivan
Approximately 60% of human immunodeficiency virus (HIV)-infected individuals are unaware of their infection, and stigma and discrimination continue to threaten acceptance of HIV testing services worldwide. Self-testing for HIV has garnered controversy for years and the debate reignited with the approval of a point-of-care test for over-the-counter sale in the US in 2012. Here, we present arguments for and against HIV self-testing. The case in support of HIV self-testing contends that: the modality is highly acceptable, especially among the most at-risk individuals; self-testing empowers users, thus helping to normalize testing; and mutual partner testing has the potential to increase awareness of risk and avert condomless sex between discordant partners. Arguments against HIV self-testing include: cost limits access to those who need testing most; false-negative results, especially during the window period, may lead to false reassurance and could promote sex between discordant partners at the time of highest infectivity; opportunities for counseling, linkage to care, and diagnosis of other sexually transmitted infections may be missed; and self-testing leads to potential for coercion between partners. Research is needed to better define the risks of self-testing, especially as performance of the assays improves, and to delineate the benefits of programs designed to improve access to self-test kits, because this testing modality has numerous potential advantages and drawbacks. PMID:25114592
Wood, Brian R; Ballenger, Carl; Stekler, Joanne D
Evidence-based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. .. by best available external clinical evidence we mean clinically relevant research.' Health care reform authorized by the Affordable Care Act is based on the belief that evidence-based practice (EBP) generates cost savings due to the delivery of more effective care.2 Medical librarians, skilled in identifying appropriate resources and working with multiple complex interfaces, can support clinicians' efforts to practice evidence based medicine by providing time and expertise in articulating the clinical question and identifying the best evidence. PMID:25507879
Yaeger, Lauren H; Kelly, Betsy
Evidence-based medicine is the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients. .. by best available external clinical evidence we mean clinically relevant research.' Health care reform authorized by the Affordable Care Act is based on the belief that evidence-based practice (EBP) generates cost savings due to the delivery of more effective care.2 Medical librarians, skilled in identifying appropriate resources and working with multiple complex interfaces, can support clinicians' efforts to practice evidence based medicine by providing time and expertise in articulating the clinical question and identifying the best evidence. PMID:25438362
Yaeger, Lauren H; Kelly, Betsy
Home care agencies often fail to commit adequate resource time preparing nurses for POC technology. Successful implementations need to incorporate human issues in addition to the technical aspects for POC. This article discusses the experiences and perceptions of nurses who participated in a pilot POC training group. The pilot group and key elements of the training are presented. The results of a focus group present the major POC focus of importance for the nurses. PMID:11771471
Thoman, J; Struk, C; Spero, M O; Stricklin, M L
During the perioperative period, which includes the period before surgery and after surgery (postoperative), it is essential to measure diagnostic parameters such as: blood oxygen saturation; hemoglobin (Hb) concentration; and pulse rate. The Hb concentration in human blood is an important parameter to evaluate the physiological condition of an individual, as Hb is the oxygen carrying component of red blood cells. By determining the Hb concentration, it is possible, for example, to observe intraoperative or postoperative bleeding, and use this information as a trigger for autologous/ allogenic blood transfusions. In blood donation center it is also an essential parameter for the decision regarding the acceptance of the donor.
Timm, Ulrich; Gewiss, Helge; Kraitl, Jens; Stuepmann, Kirstin; Hinz, Michael; Koball, Sebastian; Ewald, Hartmut
We describe an optical system which reduces the cost and complexity of fluorescence correlation spectroscopy (FCS), intended to increase the suitability of the technique for clinical use. Integration of the focusing optics and sample chamber into a plastic component produces a design which is simple to align and operate. We validate the system by measurements on fluorescent dye, and compare the results to a commercial instrument. In addition, we demonstrate its application to measurements of concentration and multimerization of the clinically relevant protein von Willebrand factor (vWF) in human plasma. PMID:23847733
Olson, Eben; Torres, Richard; Levene, Michael J.
Objective Health care professionals access various information sources to quickly answer questions that arise in clinical practice. The features that favorably influence the selection and use of knowledge resources remain unclear. We sought to better understand how clinicians select among the various knowledge resources available to them, and from this to derive a model for an effective knowledge resource. Methods We conducted 11 focus groups at an academic medical center and outlying community sites. We included a purposive sample of 50 primary care and subspecialist internal medicine and family medicine physicians. We transcribed focus group discussions and analyzed these using a constant comparative approach to inductively identify features that influence the selection of knowledge resources. Results We identified nine features that influence users' selection of knowledge resources, namely efficiency (with sub-features of comprehensiveness, searchability, and brevity), integration with clinical workflow, credibility, user familiarity, capacity to identify a human expert, reflection of local care processes, optimization for the clinical question (e.g., diagnosis, treatment options, drug side effect), currency, and ability to support patient education. No single existing resource exemplifies all of these features. Conclusion The influential features identified in this study will inform the development of knowledge resources, and could serve as a framework for future research in this field. PMID:24282535
Cook, David A.; Sorensen, Kristi J.; Hersh, William; Berger, Richard A.; Wilkinson, John M.
We have developed an ammonia-sensitive material by coupling the Berthelot reaction to our polymerized crystalline colloidal array (PCCA) technology. The material consists of a periodic array of highly charged colloidal particles (110 nm diameter) embedded in a poly(hydroxyethyl acrylate) hydrogel. The particles have a lattice spacing such that they Bragg-diffract visible light. In the Berthelot reaction, ammonia, hypochlorite, and phenol react to produce the dye molecule indophenol blue in an aqueous solution. We use this reaction in our sensor by covalently attaching 3-aminophenol to the hydrogel backbone, which forms cross-links through the Berthelot mechanism. Ammonia reacts with hypochlorite, forming monochloramine, which then reacts with a pendant aminophenol to form a benzoquinone chlorimine. The benzoquinone chlorimine reacts with another pendant aminophenol to form a cross-link. The creation of new cross-links causes the hydrogel to shrink, which reduces the lattice spacing of the embedded colloidal array. This volume change results in a blue-shift in the diffracted light proportional to the concentration of NH3 in the sample. We demonstrate that the NH3 photonic crystal sensing material is capable of quantitative determination of concentrations in the physiological range (50-350 micromol NH3 L(-1)) in human blood serum. PMID:16741766
Kimble, Kyle W; Walker, Jeremy P; Finegold, David N; Asher, Sanford A
There is a critical unmet clinical need for a device that can monitor and predict the onset of shock: hemorrhagic shock or bleeding to death, septic shock or systemic infection, and cardiogenic shock or blood flow and tissue oxygenation impairment due to heart attack. Together these represent 141 M patients per year. We have developed a monitor for shock based on measuring blood flow in peripheral (skin) capillary beds using diffuse correlation spectroscopy, a form of dynamic light scattering, and have demonstrated proof-of-principle both in pigs and humans. Our results show that skin blood flow measurement, either alone or in conjunction with other hemodynamic properties such as heart rate variability, pulse pressure variability, and tissue oxygenation, can meet this unmet need in a small self-contained patch-like device in conjunction with a hand-held processing unit. In this paper we describe and discuss the experimental work and the multivariate statistical analysis performed to demonstrate proof-of-principle of the concept.
Gurjar, Rajan S.; Riccardi, Suzannah L.; Johnson, Blair D.; Johnson, Christopher P.; Paradis, Norman A.; Joyner, Michael J.; Wolf, David E.
that the most effective way to treat a malignant tumor within body organs is to detect it early. Currently, kidney, ovary and bladder) at periodic intervals. We explore the design space for such a system to a tumor of large size and sometimes metastasizing to different organs. Fig. 1(b) shows that the cumulative
elastomeric microvalves (made by multilayer soft lithography) to be increasingly adopted for portable sensors and lab-on-a-chip systems. Introduction In recent years, the use of multilayer soft lithography for making and a computer with a portable device that can maintain high control over valve operation. Materials and methods
Sia, Samuel K.
Melanoma is a malignancy of melanocytes or pigment-producing cells located predominantly in the skin. It is less common than other skin cancers but causes the greatest number of skin cancer-related deaths worldwide. The incidence of melanoma continues to increase and early detection is the most promising means of decreasing morbidity and mortality. Currently, physicians perform routine skin cancer screenings for melanoma without the benefit of imaging devices more advanced than handheld magnifiers or dermatoscopes. However, it is possible that the diagnosis of melanoma may be improved with technology that provides diagnostic discrimination beyond what is possible on routine inspection. This article reviews current and emerging technologies to aid in the diagnosis of melanoma. Ultimately, these advances may enhance the early diagnosis of melanoma. PMID:24860656
Higgins, H William; Lee, Kachiu C; Leffell, David J
Health sciences librarians at the University of Washington (UW) are partners in the evolution of Internet-based clinical information systems for two medical centers, University of Washington Medical Center and Harborview Medical Center, as well as the UW Primary Care Network clinics. Librarians lead information resource and systems development projects and play a variety of roles including facilitator, publisher, integrator, and educator. These efforts have been coordinated with parallel development efforts by the Integrated Advanced Information Management Systems (IAIMS) clinical informatics group in developing electronic medical record systems and clinical decision support tools. The outcome is MINDscape, a very heavily used Web view of the patient medical record with tightly integrated knowledge resources as well as numerous Web-accessible information resources and tools. The goal of this article is to provide a case study of librarian involvement in institutional information systems development at UW and to illustrate the variety of roles that librarians can assume in hospital settings. PMID:10550024
Fuller, S S; Ketchell, D S; Tarczy-Hornoch, P; Masuda, D
Melanoma is a malignancy of melanocytes or pigment-producing cells located predominantly in the skin. It is less common than other skin cancers but causes the greatest number of skin cancer-related deaths worldwide. The incidence of melanoma continues to increase and early detection is the most promising means of decreasing morbidity and mortality. Currently, physicians perform routine skin cancer screenings for melanoma without the benefit of imaging devices more advanced than handheld magnifiers or dermatoscopes. However, it is possible that the diagnosis of melanoma may be improved with technology that provides diagnostic discrimination beyond what is possible on routine inspection. This article reviews current and emerging technologies to aid in the diagnosis of melanoma. Ultimately, these advances may enhance the early diagnosis of melanoma. PMID:24860656
Lee, Kachiu C.; Leffell, David J.
We are leveraging recent advances in rapid nucleic acid amplification chemistries, self-powered microfluidics, and low-cost optoelectronics to develop instrumentation for pathogen genotyping in the developing world. A growing number of correlations are emerging between genetic mutations in pathogens and their infectivity, origin, and drug resistance. Particularly for diseases like tuberculosis, where multi-drug resistance is a growing concern, a rapid diagnostic which could inform prescription decisions for newly diagnosed patients would not only save lives and reduce prolonged sickness but would help slow the emergence of more virulent strains. Additionally, for pathogens such as HIV, there is a need for new assay formats which can inexpensively and quantitativly monitor pathogen load. We have developed a portable instrument which uses disposable microfluidic assay cartridges pre-loaded with lyophilized reagents for genetic amplification of multiple markers. The cartridges can be adapted for a variety of sample types (blood, sputum, saliva). The instrument controls assay temperature and quantitatively monitors real-time fluorescence signals from 96 individual reaction chambers. The platform can be tailored for different economic situations--from a quantitative electronic readout to a simple binary readout with the naked eye. PMID:22255135
Myers, Frank B; Henrikson, Richard H; Xu, Liyi; Lee, Luke P
Abstract China is experiencing a syphilis epidemic of enormous proportions. The regions most heavily affected by syphilis correspond to regions where sexually transmitted HIV infection is also a major public health threat. Many high-risk patients in China fail to receive routine syphilis screening. This missed public health opportunity stems from both a failure of many high-risk individuals to seek clinical care and a disconnect between policy and practice. New point-of-care syphilis testing enables screening in non-traditional settings such as community organizations or sex venues. This paper describes the current Chinese syphilis policies, suggests a spatiotemporal framework (based on targeting high-risk times and places) to improve screening and care practices, and emphasizes a syphilis control policy extending beyond the clinical setting. PMID:20539859
Hawkes, Sarah J; Yin, Yue-Pin; Peeling, Rosanna W; Cohen, Myron S; Chen, Xiang-Sheng
Point-of-care testing (POCT) of biomarkers in clinical samples is of great importance for rapid and cost-effective diagnosis. However, it is extremely challenging to develop an electrochemical POCT technique retaining both ultrasensitivity and simplicity. We report an interference-free electrochemical lateral-flow immunoassay that enables one-step ultrasensitive detection with serum. The electrochemical-chemical-chemical (ECC) redox cycling combined with an enzymatic reaction of an enzyme label is used to obtain high signal amplification. The ECC redox cycling involving Ru(NH3)6(3+), enzyme product, and tris(3-carboxyethyl)phosphine (TCEP) depends on pH, because the formal potentials of an enzyme product and TCEP increase with decreasing pH although that of Ru(NH3)6(3+) is pH-independent. With consideration of the pH dependence of ECC redox cycling, a noble combination of enzyme label, substrate, and product [?-galactosidase, 4-amino-1-naphthyl ?-D-galactopyranoside, and 4-amino-1-naphthol, respectively] is introduced to ensure fast and selective ECC redox cycling of the enzyme product along with a low background level. The selective ECC redox cycling at a low applied potential (0.05 V vs. Ag/AgCl) minimizes the interference effect of electroactive species (L-ascorbic acid, acetaminophen, and uric acid) in serum. A detection limit of 0.1 pg mL(-1) for troponin I is obtained only 11 min after serum dropping without the use of an additional solution. Moreover, the lateral-flow immunoassay is applicable to the analysis of real clinical samples. PMID:24482801
Akanda, Md Rajibul; Joung, Hyou-Arm; Tamilavan, Vellaiappillai; Park, Seonhwa; Kim, Sinyoung; Hyun, Myung Ho; Kim, Min-Gon; Yang, Haesik
This paper introduces the design of a novel time-resolved fluorometer based on immunochromatograghy. Different from the other time-resolved fluorometers, it tests the immunochromatographic strip which is labeled with lanthanide ions and their chelates. This instrument can provide a rapid, quantitative measurement of analytes present in samples without any washing steps and it can be used to carry out point-of-care test (POCT). The immunochromatograghy-based timeresolved fluorometer is composed of a specific optical sensor, a scanning stage, a signal processing system and a computer control system. The light from UV LED is focused on the test strip by a condense lens group in the optical sensor. If the labels are present in samples, the fluorescence at 613nm will be exited (when Eu3+chelate is used for marking substance). After a delay of some microseconds, the fluorescence will be collected by the optical sensor and converted into electronic signal by a photomultiplier tube (PMT). The concentration of the sample can be calculated through the standard working curve of this instrument. By testing, the sensitivity is several ng/ml level (when Eu3+chelate is used for marking substance), test linear range is from several ng/ml to 103 ng/ml, in which correlation coefficient is 99.97%.
Ren, Bingqiang; Huang, Lihua; Huang, Huijie
ABSTRACT One of the major hurdles in treating tuberculosis (TB) is the time-consuming and difficult methodology for diagnosis. Stable-isotope breath tests hold great potential for rapidly diagnosing an infectious disease, monitoring therapy, and determining a bacterial phenotype in a rapid, point-of-care manner that does not require invasive sampling. Here we describe the preclinical development of a potentially highly selective TB diagnostic breath test based upon the organism’s CO dehydrogenase activity. After development of the test in vitro, we were able to use the breath test to discriminate between infected and control rabbits, demonstrating that a diagnosis can potentially be made and also that a complex bacterial phenotype can be noninvasively and rapidly studied in the host. PMID:24736224
Maiga, Mamoudou; Choi, Seong Won; Atudorei, Viorel; Maiga, Mariama C.; Sharp, Zachary D.; Bishai, William R.; Timmins, Graham S.
Institutional practices and policies in acid-base testing: a self reported Croatian survey study on behalf of the Croatian society of medical biochemistry and laboratory medicine Working Group for acid-base balance
Introduction: The aim of this survey study was to assess the current practices and policies in use related to the various steps in the blood gas testing process, across hospital laboratories in Croatia. Materials and methods: First questionnaire was sent by email to all medical biochemistry laboratories (N = 104) within general, specialized and clinical hospitals and university hospital centres to identify laboratories which perform blood gas analysis. Second questionnaire with detailed questions about sample collection, analysis and quality control procedures, was sent only to 47 laboratories identified by the first survey. Questionnaire was designed as combination of questions and statements with Likert scale. Third questionnaire was sent to all participating laboratories (N=47) for additional clarification for either indeterminate or unclear answers. Results: Blood gas analysis is performed in 47/104 hospital laboratories in Croatia. In 25/41 (0.61) of the laboratories capillary blood gas sampling is the preferred sample type for adult patient population, whereas arterial blood sample is preferentially used in only 5/44 laboratories (0.11). Blood sampling and sample processing for capillary samples is done almost always by laboratory technicians (36/41 and 37/44, respectively), whereas arterial blood sampling is almost always done by the physician (24/29) and only rarely by a nurse (5/28). Sample acceptance criteria and sample analysis are in accordance with international recommendations for majority of laboratories. 43/44 laboratories participate in the national EQA program. POCT analyzers are installed outside of the laboratory in 20/47 (0.43) institutions. Laboratory staff is responsible for education and training of ward personnel, quality control and instrument maintenance in only 12/22, 11/20 and 9/20 institutions, respectively. Conclusions: Practices related to collection and analysis for blood gases in Croatia are not standardised and vary substantially between laboratories. POCT analyzers are not under the direct supervision by laboratory personnel in a large proportion of surveyed institutions. Collective efforts should be made to harmonize and improve policies and procedures related to blood gas testing in Croatian laboratories. PMID:24969922
Duki?, Lora; Šimundi?, Ana-Maria
Platelet ADhesion Assay (PADA) is a POCT capable method for quantitative determination of platelet adhesiveness. Using special polymer particles and test conditions adjusted to the physiologic conditions, the current functional state of blood platelets is determined directly from a whole blood sample. Within a short time, using little technical equipment and small sample volume, a therapeutic drug monitoring of GP IIb/IIIa and ADP receptor antagonists is possible, too. Whereas in healthy volunteers dose/effect curves of GP IIb/IIIa antagonists vary only slightly, in thrombopilic patients there are big variations. Differences in efficacy up to drug resistance may occur also in use of the ADP receptor antagonist clopidogrel. A therapeutic drug monitoring of GP IIb/IIIa- and ADP receptor antagonist therapy is essential and becomes feasible using PADA, also as long-term drug monitoring of ADP receptor antagonists and detection of drug resistance. Additionally, an individual ex vivo dose estimation for GP IIb/IIIa antagonists is possible. PADA allows diagnostics of pathological platelet function in thrombophilic patients as well as long-term therapeutic drug monitoring due to its simple handling. PMID:15314708
Schumann, A; Wiesenburg, A; Bucha, E; Nowak, G
In recent years, rapid diagnostic tests (RDTs) have been widely used for malaria detection, primarily because of their simple operation, fast results, and straightforward interpretation. The Asan EasyTest™ Malaria Pf/Pan Ag is one of the most commonly used malaria RDTs in several countries, including Korea and India. In this study, we tested the diagnostic performance of this RDT in Uganda to evaluate its usefulness for field diagnosis of malaria in this country. Microscopic and PCR analyses, and the Asan EasyTest™ Malaria Pf/Pan Ag rapid diagnostic test, were performed on blood samples from 185 individuals with suspected malaria in several villages in Uganda. Compared to the microscopic analysis, the sensitivity of the RDT to detect malaria infection was 95.8% and 83.3% for Plasmodium falciparum and non-P. falciparum, respectively. Although the diagnostic sensitivity of the RDT decreased when parasitemia was ?500 parasites/µl, it showed 96.8% sensitivity (98.4% for P. falciparum and 93.8% for non-P. falciparum) in blood samples with parasitemia ?100 parasites/µl. The specificity of the RDT was 97.3% for P. falciparum and 97.3% for non-P. falciparum. These results collectively suggest that the accuracy of the Asan EasyTest™ Malaria Pf/Pan Ag makes it an effective point-of-care diagnostic tool for malaria in Uganda. PMID:25352698
Chong, Chom-Kyu; Cho, Pyo Yun; Na, Byoung-Kuk; Ahn, Seong Kyu; Kim, Jin Su; Lee, Jin-Soo; Lee, Sung-Keun; Han, Eun-Taek; Kim, Hak-Yong; Park, Yun-Kyu; Cha, Seok Ho
Surface plasmon resonance (SPR) is a medical diagnosis technique with high sensitivity and specificity. In this research, a new method based on SPR is proposed for rapid, 10-minute detection of the anti-dengue virus in human serum samples. This novel technique, known as rapid immunoglobulin M (IgM)-based dengue diagnostic test, can be utilized quickly and easily at the point of care. Four dengue virus serotypes were used as ligands on a biochip. According to the results, a serum volume of only 1??l from a dengue patient (as a minimized volume) is required to indicate SPR angle variation to determine the ratio of each dengue serotype in samples with 83–93% sensitivity and 100% specificity. PMID:24458089
Jahanshahi, Peyman; Zalnezhad, Erfan; Sekaran, Shamala Devi; Adikan, Faisal Rafiq Mahamd
1.Technology Description-Researchers discovered that when the Varicella Zoster Virus (VZV) reactivates from latency in the body, the virus is consistently present in saliva before the appearance of skin lesions. A small saliva sample is mixed with a specialized reagent in a test kit. If the virus is present in the saliva sample, the mixture turns a red color. The sensitivity and specificity emanates from an antibody-antigen reaction. This technology is a rapid, non-invasive, point of-of-care testing kit for detecting the virus from a saliva sample. The device is easy to use and can be used in clinics and in remote locations to quickly detect VZV and begin treatment with antiviral drugs. 2.Market Opportunity- RST Bioscience will be the first and only company to market a rapid, same day test kit for the detection of VZV in saliva. The RST detection test kit will have several advantages over existing, competitive technology. The test kit is self contained and laboratory equipment is not required for analysis of the sample. Only a single saliva sample is required to be taken instead of blood or cerebral spinal fluid. The test kit is portable, sterile and disposable after use. RST detection test kits require no electrical power or expensive storage equipment and can be used in remote locations. 3.Market Analysis- According to the CDC, it is estimated that 1 million cases of shingles occur each year in the U.S. with more than half over the age of sixty. There is a high demand for rapid diagnostics by the public. The point-of-care testing (POCT) market is growing faster than other segments of in vitro diagnostics. According to a July 2007 InteLab Corporation industry report the overall market for POCT was forecast to increase from $10.3 billion in 2005 to $18.7 billion by 2011. The market value of this test kit has not been determined. 4.Competition- The VZV vaccine prevents 50% of cases and reduces neuralgia by 66%. The most popular test detects VZV-specific IgM antibody in blood. Other tests include running a sample in a polymerase chain reaction analyzer, enzyme immunoassay, latex agglutination, indirect fluorescent antibody and fluorescent antibody to membrane antigen assay. These existing tests require laboratory analysis by trained personnel, expensive equipment, invasive procedures and a longer period of time to obtain test results.
Lewis, Michelle P.; Harding, Robert
Tuberculosis (TB) remains a significant public health issue worldwide especially in developing countries, where the disease is endemic, and effective TB diagnostic as well as treatment-monitoring tools are serious barriers to defeating the disease. Detection of pathogen-specific metabolic pathways offers a potential alternative to current methods, which focus on bacterial growth, bacterial nucleic acid amplification, or detection of host immune response to the pathogen. Metabolic pathway detection may provide rapid and effective new tools for TB that can improve TB diagnostics for children and HIV infected patients. Metabolic breath tests are attractive because these are safe, and provide an opportunity for rapid point of care diagnostics and tool for drug efficacy evaluation during clinical trials. Our group has developed a rabbit urease breath test model to evaluate the sensitivity and the specificity of urease based detection of Mycobacterium tuberculosis. TB infected rabbits were given stable isotopically labelled urea as the substrate. The urea tracer was metabolized to 13 C-CO 2 and detected in exhaled breaths using portable infrared spectrometers. The signal correlated with bacterial load both for primary diagnostics and treatment monitoring. Clinical trials are currently ongoing to evaluate the value of the test in clinical management settings. Urea breath testing may provide a useful diagnostic and biomarker assay for tuberculosis and treatment response. PMID:22771606
Maiga, Mamoudou; Abaza, Ahmed; Bishai, William R
A new application of gold nanoparticles (AuNPs) as a colorimetric method for gene detection of ?-thalassemia 1 (SEA deletion) is reported here for the first time. This technique is based on color changes from salt-induced aggregation of un-hybridized nanogold probes after hybridization with the target DNA. Specific DNA probes were synthesized, thiol modified and conjugated on the surface of AuNPs. The target DNA was amplified and hybridized with the AuNPs-immobilized probe. Salt solution (NaCl) was added to induce aggregation of the un-hybridized nanogold probes. The color changes were visualized either by the naked eye or by UV-vis spectrophotometry at 520 nm. By this nanogold colorimetric method samples carrying normal ?-globin genes could be successfully identified from samples carrying ?-globin genes causing ?-thalassemia 1 (SEA deletion), either as a carrier or disease form. Results demonstrated that the new colorimetric nanogold method is a definite gene diagnosis of ?-thalassemia. It is accurate, simple, rapid, specific, sensitive, and cost effective. It is also a promising point-of-care testing (POCT) method for thalassemias and other genetic disorders. The new colorimetric nanogold is a method of choice for areas where access to sophisticated molecular diagnosis is limited. PMID:24383063
Chomean, Sirinart; Wangmaung, Nantawan; Sritongkham, Pornpimol; Promptmas, Chamras; Mas-Oodi, Sumana; Tanyong, Dalina; Ittarat, Wanida
MicroRNAs (miRNAs) have been identified as promising cancer biomarkers due to their stable presence in serum. As an alternative to PCR-based homogenous assays, surface-based electrochemical biosensors offer great opportunities for low-cost, point-of-care tests (POCTs) of disease-associated miRNAs. Nevertheless, the sensitivity of miRNA sensors is often limited by mass transport and crowding effects at the water-electrode interface. To address such challenges, we herein report a DNA nanostructure-based interfacial engineering approach to enhance binding recognition at the gold electrode surface and drastically improve the detection sensitivity. By employing this novel strategy, we can directly detect as few as attomolar (<1, 000 copies) miRNAs with high single-base discrimination ability. Given that this ultrasensitive electrochemical miRNA sensor (EMRS) is highly reproducible and essentially free of prior target labeling and PCR amplification, we also demonstrate its application by analyzing miRNA expression levels in clinical samples from esophageal squamous cell carcinoma (ESCC) patients. PMID:23162691
Wen, Yanli; Pei, Hao; Shen, Ye; Xi, Junjie; Lin, Meihua; Lu, Na; Shen, Xizhong; Li, Jiong; Fan, Chunhai
MicroRNAs (miRNAs) are key regulators of a wide range of cellular processes, and have been identified as promising cancer biomarkers due to their stable presence in serum. As an surface-based electrochemical biosensors which offer great opportunities for low-cost, point-of-care tests (POCTs) of disease-associated miRNAs. Nevertheless, the sensitivity of miRNA sensors is often limited by mass transport and the surface crowding effect at the water-electrode interface. Here, we present a protocol as well as guidelines for ultrasensitive detection of miRNA with DNA nanostructure-based electrochemical miRNA biosensor. By employing the three-dimensional DNA nanostructure-based interfacial engineering approach, we can directly detect as few as attomolar (<1000 copies) miRNAs with high single-base discrimination ability. Since this ultrasensitive electrochemical miRNA sensor (EMRS) is highly reproducible and essentially free of prior target labeling and PCR amplification, it can conveniently and reliably analyze miRNA expression levels in clinical samples from esophageal squamous cell carcinoma (ESCC) patients. PMID:23911620
Wen, Yanli; Liu, Gang; Pei, Hao; Li, Lanying; Xu, Qin; Liang, Wen; Li, Yan; Xu, Li; Ren, Suzhen; Fan, Chunhai
We report on a cartridge based platform for complex immunoassay formats that allows for flexible adaption of individual steps. It is a sample-to-answer system which is quantitative as well as sensitive. The target molecules are detected through a magnetic bead-based fluorescence sandwich immunoassay. The beads both constitute the solid phase for immobilizing capture molecules and are used for magnetic field activated incubation. The injection molded cartridge comprises several chambers separated by capillary valves. Chambers contain the assay reagents, through which the beads are manipulated via externally applied magnetic fields. Active incubation is made possible by assembling the beads into microstirrers and systematically scanning through a chamber. The beads are transported by focusing them to form an aggregate which subsequently is dragged through the valves. Once the aggregate enters a chamber, it is re-dispersed and magnetic actuation is used to re-assemble the beads into microstirrers. The assay protocol involves an incubation of sample with antibody coated magnetic beads, followed by steps for washing or separation, labeling with fluorescent detection antibody and finally fluorescence detection. An interleukin-8 assay served as a model for evaluating the system and a concentration as low as 5 pg/mL (0.625 pM) was successfully detected. The platform shows potential to be developed into a diagnostic tool to be used in a point-of-care testing (PoCT) environment. PMID:24091714
Gottheil, Raiah; Baur, Nadja; Becker, Holger; Link, Gorden; Maier, Dimitri; Schneiderhan-Marra, Nicole; Stelzle, Martin
Patient safety is a management issue, in view of the fact that clinical risk management has become an important part of hospital management. Failure Mode and Effect Analysis (FMEA) is a proactive technique for error detection and reduction, firstly introduced within the aerospace industry in the 1960s. Early applications in the health care industry dating back to the 1990s included critical systems in the development and manufacture of drugs and in the prevention of medication errors in hospitals. In 2008, the Technical Committee of the International Organization for Standardization (ISO), licensed a technical specification for medical laboratories suggesting FMEA as a method for prospective risk analysis of high-risk processes. Here we describe the main steps of the FMEA process and review data available on the application of this technique to laboratory medicine. A significant reduction of the risk priority number (RPN) was obtained when applying FMEA to blood cross-matching, to clinical chemistry analytes, as well as to point-of-care testing (POCT). PMID:19298799
Chiozza, Maria Laura; Ponzetti, Clemente
Considering the urgent demand for rapid and accurate determination of bacterial toxins and the recent promising developments in nanotechnology and microfluidics, this review summarizes new achievements of the past five years. Firstly, bacterial toxins will be categorized according to their antibody binding properties into low and high molecular weight compounds. Secondly, the types of antibodies and new techniques for producing antibodies are discussed, including poly- and mono-clonal antibodies, single-chain variable fragments (scFv), as well as heavy-chain and recombinant antibodies. Thirdly, the use of different nanomaterials, such as gold nanoparticles (AuNPs), magnetic nanoparticles (MNPs), quantum dots (QDs) and carbon nanomaterials (graphene and carbon nanotube), for labeling antibodies and toxins or for readout techniques will be summarized. Fourthly, microscale analysis or minimized devices, for example microfluidics or lab-on-a-chip (LOC), which have attracted increasing attention in combination with immunoassays for the robust detection or point-of-care testing (POCT), will be reviewed. Finally, some new materials and analytical strategies, which might be promising for analyzing toxins in the near future, will be shortly introduced. PMID:24732203
Zhu, Kui; Dietrich, Richard; Didier, Andrea; Doyscher, Dominik; Märtlbauer, Erwin
In this paper, we describe the development of an automated sample preparation procedure for etiological agents of community-acquired lower respiratory tract infections (CA-LRTI). The consecutive assay steps, including sample re-suspension, pre-treatment, lysis, nucleic acid purification, and concentration, were integrated into a microfluidic lab-on-a-chip (LOC) cassette that is operated hands-free by a demonstrator setup, providing fluidic and valve actuation. The performance of the assay was evaluated on viral and Gram-positive and Gram-negative bacterial broth cultures previously sampled using a nasopharyngeal swab. Sample preparation on the microfluidic cassette resulted in higher or similar concentrations of pure bacterial DNA or viral RNA compared to manual benchtop experiments. The miniaturization and integration of the complete sample preparation procedure, to extract purified nucleic acids from real samples of CA-LRTI pathogens to, and above, lab quality and efficiency, represent important steps towards its application in a point-of-care test (POCT) for rapid diagnosis of CA-LRTI. PMID:24615272
Van Heirstraeten, Liesbet; Spang, Peter; Schwind, Carmen; Drese, Klaus S; Ritzi-Lehnert, Marion; Nieto, Benjamin; Camps, Marta; Landgraf, Bryan; Guasch, Francesc; Corbera, Antoni Homs; Samitier, Josep; Goossens, Herman; Malhotra-Kumar, Surbhi; Roeser, Tina
MicroRNAs (miRNAs) have been identified as promising cancer biomarkers due to their stable presence in serum. As an alternative to PCR-based homogenous assays, surface-based electrochemical biosensors offer great opportunities for low-cost, point-of-care tests (POCTs) of disease-associated miRNAs. Nevertheless, the sensitivity of miRNA sensors is often limited by mass transport and crowding effects at the water-electrode interface. To address such challenges, we herein report a DNA nanostructure-based interfacial engineering approach to enhance binding recognition at the gold electrode surface and drastically improve the detection sensitivity. By employing this novel strategy, we can directly detect as few as attomolar (<1, 000 copies) miRNAs with high single-base discrimination ability. Given that this ultrasensitive electrochemical miRNA sensor (EMRS) is highly reproducible and essentially free of prior target labeling and PCR amplification, we also demonstrate its application by analyzing miRNA expression levels in clinical samples from esophageal squamous cell carcinoma (ESCC) patients.
Wen, Yanli; Pei, Hao; Shen, Ye; Xi, Junjie; Lin, Meihua; Lu, Na; Shen, Xizhong; Li, Jiong; Fan, Chunhai
Point-of-care testing (POC, POCT) laboratory devices are being introduced into operating suites and critical care units in ever increasing numbers. The small, portable devices have gained in popularity because of their ease of use and the rapid availability of test results. POCT is an integral part of extracorporeal technology (ECT). A challenge associated with the growth of POC technology is related to management of the data generated by these devices. In the field of ECT, storing, retrieving, analyzing, viewing and charting quality control (QC) and patient test data generated with POC coagulation instruments is essential. We evaluated a premarket version of data management software developed for the Hemochron Jr. Signature coagulation analyzer, a PC-based software capable of fulfilling our objective. A database comprised of greater than 50 plasma and electronic QC results and greater than 140 patient sample results for ACT, PT, and aPTT tests was transferred from a Hemochron Jr. Signature device to two different PCs, each equipped with Hemochron ReportMaker software supplied by the manufacturer. Data files were transferred directly from the coagulation test unit to the PCs via an RS-232 cable. A variety of charts, reports, and file listings were created from the datasets using the software menus. Transfer of the complete database required less than 5 min. The relative speed and simplicity of the data interface promotes frequent charting of QC data, permitting real-time monitoring and early identification of data trends or values requiring intervention. If a subset of QC data is found to be incomplete, altered, or unacceptable, all patient samples tested during that period can be promptly identified. The software also includes data query tools useful for sorting and selecting specific subsets of patient and QC data. Electronic data management can facilitate compliance with quality control requirements and assist clinicians and laboratory personnel in the collection, storage, and review of quality control and patient test data. In addition, the patient and QC data are readily accessible when necessary for use in risk management assessment, accreditation, or litigation proceedings. PMID:12395963
Searles, Bruce; Nasrallah, Fadi; Graham, Susan; Tozer, Michelle
Data on the performance of rapid molecular point-of-care use platforms for diagnosis of influenza are lacking. We validated nasopharyngeal (NP) flocked specimens in universal transport medium (UTM) and evaluated the clinical sensitivity and specificity of the Alere i influenza A&B test compared to those of the Xpert flu A/B assay. The Alere i influenza A&B test had an overall sensitivity and specificity of 93.8% and 62.5% for influenza A, respectively, and of 91.8% and 53.6% for influenza B, respectively. The poor specificity was due to influenza virus samples determined positive for both type A and B. PMID:25502527
Chapin, Kimberle C; Flores-Cortez, Estefany J
In the USA, 21% of the estimated 1.1 million people living with human immunodeficiency virus/acquired immune deficiency syndrome (HIV/AIDS) are unaware they are HIV-infected. In 2011, Veterans Health Administration (VHA)'s Office of Public Health in conjunction with VHA's Health Care for Homeless Veterans Program funded grants to support rapid HIV testing at homeless outreach events because homeless populations are more likely to obtain emergent rather than preventive care and have a higher HIV seroprevalence as compared to the general population. Because of a Veterans Affairs North Texas Health Care System (VANTHCS)'s laboratory testing requirement, VANTHCS partnered with community agencies to offer rapid HIV testing for the first time at VANTHCS' 2011 Homeless Stand Downs in Dallas, Fort Worth, and Texoma, Texas. Homeless Stand Downs are outreach events that connect Veterans with services. Veterans who declined testing were asked their reasons for declining. Comparisons by Homeless Stand Down site used Pearson ?², substituting Fisher's Exact tests for expected cell sizes <5. Of the 910 Veterans attending the Homeless Stand Downs, 261 Veterans reported reasons for declining HIV testing, and 133 Veterans were tested, where 92% of the tested Veterans obtained their test results at the events - all tested negative. Veterans' reported reasons for declining HIV testing included previous negative result (n=168), no time to test (n=49), no risk factors (n=36), testing is not a priority (n=11), uninterested in knowing serostatus (n=6), and HIV-infected (n=3). Only "no time to test" differed significantly by Homeless Stand Down site. Nonresponse rate was 54%. Offering rapid HIV testing at Homeless Stand Downs is a promising testing venue since 15% of Veterans attending VANTHCS' Homeless Stand Downs were tested for HIV, and majority obtained their HIV test results at point-of-care while further research is needed to determine how to improve these rates. PMID:23750751
Hooshyar, Dina; Surís, Alina M; Czarnogorski, Maggie; Lepage, James P; Bedimo, Roger; North, Carol S
In 2010, New York (NY) passed new legislation mandating Emergency Departments (EDs) to offer HIV tests to patients 13-64 presenting for care. We evaluated the requirement's implementation and determined differences based on HIV prevalence or site-specific designated AIDS centers (DACs). We also evaluated policies for linkage to care of new HIV positive patients. An electronic survey on testing practices and linkage to care was administered to all NY EDs, excluding VA hospitals. Basic descriptive statistics were used for analysis. The response rate was 96% (184/191). All respondents knew of the legislation and 86% offered testing, but only 65% (159/184) to all patients required by the law. EDs in NYC, high prevalence areas, and DACs were more likely to offer HIV testing. Most facilities (104/159, 65%) used separate written consent despite elimination of this requirement. Most EDs (67%) used rapid testing: oral point-of-care ED testing and rapid laboratory testing. Only 61% of EDs provided results to patients while in the ED. Most (94%) had a linkage-to-care protocol. However, only 29% confirm linkage. We provide the first report of NY ED HIV testing practices since the mandatory testing law. Most EDs offer HIV testing but challenges still exist. Linkage-to-care plans are in place, but few EDs confirm it occurs. PMID:24517540
Egan, Daniel J; Cowan, Ethan; Fitzpatrick, Laura; Savitsky, Leah; Kushner, John; Calderon, Yvette; Agins, Bruce D
Chronic illness including cardiovascular disease (CVD) is a major burden on the healthcare system. Behavioral and lifestyle changes could significantly reduce the burden of CVD, but provider counseling for behavior change is a very challenging, and often ineffective task. We have developed a patient-centric decision support tool to be incorporated into an Electronic Health Record system (EHR). The tool provides tailored feedback on behavioral risk, readiness and confidence in an effort to empower patients to make decisions about improving health behaviors. In turn, the tool will facilitate an informed and balanced discussion between patients and their providers about behavioral changes, incorporating both the clinical view and the individual’s preferences for choosing among multiple behavior change goals based on their psychosocial characteristics, and evaluation of benefits and barriers. PMID:20351881
Li, Jianhua; Khan, Sharib A.; Mark, Jessica; Nivarthi, Phani K.; Misra, Rupa; Chan, Connie; Kaufman, David; Kukafka, Rita
Devices A Novel Device for Long-term Organ Preservation Conley Jones, Mats Dreyer, Gary, David Fisher, Rebecca Menke,Tianye Yao Energy Bacteriophage-based Electric Generators for Portable Electronics I-Chin Wu
Sekhon, Jasjeet S.
A novel electrochemical sensing method was devised for the first time to detect plasma cortisol, a potential psychological stress biomarker, in human immunodeficiency virus (HIV)-positive subjects. A miniaturized potentiostat (reconfigured LMP91000 chip) interfaced with a microfluidic manifold containing a cortisol immunosensor was employed to demonstrate electrochemical cortisol sensing. This fully integrated and optimized electrochemical sensing device exhibited a wide cortisol-detection range from 10 pg/mL to 500 ng/mL, a low detection limit of 10 pg/mL, and sensitivity of 5.8 ?A (pg mL)?1, with a regression coefficient of 0.995. This cortisol-selective sensing system was employed to estimate plasma cortisol in ten samples from HIV patients. The electrochemical cortisol-sensing performance was validated using an enzyme-linked immunosorbent assay technique. The results obtained using both methodologies were comparable within 2%–5% variation. The information related to psychological stress of HIV patients can be correlated with disease-progression parameters to optimize diagnosis, therapeutic, and personalized health monitoring. PMID:25632229
Kaushik, Ajeet; Yndart, Adriana; Jayant, Rahul Dev; Sagar, Vidya; Atluri, Venkata; Bhansali, Shekhar; Nair, Madhavan
A nontraditional approach to leadership development promoted successful transition of new graduate RN residents to professional nurses. Utilizing an outdoor adventure program increased nurses' feelings of competence by boosting their confidence, facilitating an environment where leadership at the bedside became an ingrained part of their nursing practice. RN residents at a Midwestern medical center represented only 17% of the nursing population but reshaped the culture of the entire organization by becoming dynamic "everyday" leaders. PMID:25608096
Greer-Day, Susan; Medland, Jackie; Watson, Lynn; Bojak, Sarah
Objective: To conduct a prospective cohort study to determine the frequency and characteristics of Shiga toxin (Stx)-producing Escherichia coli (STEC) infections in children with diarrhea attending an emergency department and a private clinic in Seattle, Washington. Methods: Between November 1998 and October 2001, 1851 stools were processed for STEC by sorbitol-MacConkey (SMAC) agar screening and a commercial Stx enzyme immunoassay
Eileen J. Klein; Jennifer R. Stapp; Carla R. Clausen; Daniel R. Boster; Joy G. Wells; Xuan Qin; David L. Swerdlow; Phillip I. Tarr
The 2001 World Health Organization (WHO) treatise on the classification of hematopoietic tumors lists chronic myeloproliferative diseases (CMPDs) as a subdivision of myeloid neoplasms that includes the four classic myeloproliferative disorders (MPDs)—chronic myelogenous leukemia, polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF)—as well as chronic neutrophilic leukemia (CNL), chronic eosinophilic leukemia\\/hypereosinophilic syndrome (CEL\\/HES) and ‘CMPD, unclassifiable’. In the
A Tefferi; J W Vardiman; A Tefferi
We present an all-thermoplastic integrated sample-to-answer centrifugal microfluidic Lab-on-Disc system (LoD) for nucleic acid analysis. The proposed CD system and engineered platform were employed for analysis of Bacillus atrophaeus subsp. globigii spores. The complete assay comprised cellular lysis, polymerase chain reaction (PCR) amplification, amplicon digestion, and microarray hybridization on a plastic support. The fluidic robustness and operating efficiency of the assay were ensured through analytical optimization of microfluidic tools enabling beneficial implementation of capillary valves and accurate control of all flow timing procedures. The assay reliability was further improved through the development of two novel microfluidic strategies for reagents mixing and flow delay on the CD platform. In order to bridge the gap between the proof-of-concept LoD and production prototype demonstration, low-cost thermoplastic elastomer (TPE) was selected as the material for CD fabrication and assembly, allowing the use of both, high quality hot-embossing and injection molding processes. Additionally, the low-temperature and pressure-free assembly and bonding properties of TPE material offer a pertinent solution for simple and efficient loading and storage of reagents and other on-board components. This feature was demonstrated through integration and conditioning of microbeads, magnetic discs, dried DNA buffer reagents and spotted DNA array inserts. Furthermore, all microfluidic functions and plastic parts were designed according to the current injection mold-making knowledge for industrialization purposes. Therefore, the current work highlights a seamless strategy that promotes a feasible path for the transfer from prototype toward realistic industrialization. This work aims to establish the full potential for TPE-based centrifugal system as a mainstream microfluidic diagnostic platform for clinical diagnosis, water and food safety, and other molecular diagnostic applications. PMID:25385141
Roy, Emmanuel; Stewart, Gale; Mounier, Maxence; Malic, Lidija; Peytavi, Régis; Clime, Liviu; Madou, Marc; Bossinot, Maurice; Bergeron, Michel G; Veres, Teodor
Recently, digital photography has become an efficient and economic method to assist dermatologists in monitoring skin characteristics. Although this technology has advanced a great deal in resolution and costs, conventional digital cameras continue to only provide qualitative recording of color information. To address this issue, we are developing a compact, quantitative skin imaging camera by employing spatial frequency domain imaging (SFDI), a non-contact approach for determining tissue optical properties over a wide field-of-view. SFDI uses knowledge of optical properties at multiple wavelengths to recover concentrations of tissue constituents such as oxy/deoxy-hemoglobin, water, and melanin. This method has been well researched and presented in laboratory and research settings. The next step in the development of SFDI systems is to make typical systems compact and cheaper using commercial components. We present our findings by performing a component-by-component analysis of key SFDI system components including light sources, projectors, and cameras.
Nadeau, K. P.; Khoury, P.; Mazhar, A.; Cuccia, D.; Durkin, A. J.
Obtaining accurate needle placement is of critical importance in many medical scenarios. In the setting of fine needle aspiration biopsy (FNAB), manual palpation is often the only cue for determining the optimal position ...
Goldberg, Brian, 1979-
HIV has become one of the most devastating pathogens in human history. Despite fast progress in HIV-related basic research, antiretroviral therapy (ART) remains the most effective method to save AIDS patients' lives. Unfortunately, ART cannot be universally accessed, especially in developing countries, due to the lack of effective treatment monitoring diagnostics. Here, we present an inexpensive, rapid and portable micro-a-fluidic platform, which can streamline the process of an enzyme-linked immunosorbent assay (ELISA) in a fully automated manner for CD4 cell count. The micro-a-fluidic CD4 cell count is achieved by eliminating operational fluid flow via “moving the substrate”, as opposed to “flowing liquid” in traditional ELISA or microfluidic methods. This is the first demonstration of capturing and detecting cells from unprocessed whole blood using the enzyme-linked immunosorbent assay (ELISA) in a microfluidic channel. Combined with cell phone imaging, the presented micro-a-fluidic ELISA platform holds great promise for offering rapid CD4 cell count to scale up much needed ART in resource-constrained settings. The developed system can be extended to multiple areas for ELISA-related assays. PMID:24448112
Wang, ShuQi; Tasoglu, Savas; Chen, Paul Z.; Chen, Michael; Akbas, Ragip; Wach, Sonya; Ozdemir, Cenk Ibrahim; Gurkan, Umut Atakan; Giguel, Francoise F.; Kuritzkes, Daniel R.; Demirci, Utkan
HIV has become one of the most devastating pathogens in human history. Despite fast progress in HIV-related basic research, antiretroviral therapy (ART) remains the most effective method to save AIDS patients' lives. ...
' medication safety efforts will be upon the prevention of IV medication administration errors, particularly delivery remains highly vulnerable to error. Medication errors associated with IV-delivered drugs include ("smart pumps") help reduce tradi- tional medication errors through programming and calculating dose
Bacterial vaginosis (BV) is the most common cause of abnormal vaginal discharge in reproductive age women. It is associated with increased susceptibility to HIV/STI and adverse birth outcomes. Diagnosis of BV in resource-poor settings like India is challenging. With little laboratory infrastructure there is a need for objective point-of-care diagnostic tests. Vaginal swabs were collected from women 18 years and older, with a vaginal pH>4.5 attending a reproductive health clinic. BV was diagnosed with Amsel's criteria, Nugent scores, and the OSOM BVBlue test. Study personnel were blinded to test results. There were 347 participants enrolled between August 2009 and January 2010. BV prevalence was 45.1% (95% confidence interval (CI): 41.5%-52.8%) according to Nugent score. When compared with Nugent score, the sensitivity, specificity, positive predictive value, negative predictive value for Amsel's criteria and BVBlue were 61.9%, 88.3%, 81.5%, 73.7% and 38.1%, 92.7%, 82.1%, 63.9%, respectively. Combined with a "whiff" test, the performance of BVBlue increased sensitivity to 64.4% and negative predictive value to 73.8%. Despite the good specificity, poor sensitivity limits the usefulness of the BVBlue as a screening test in this population. There is a need to examine the usefulness of this test in other Indian populations. PMID:24526829
Madhivanan, Purnima; Krupp, Karl; Li, Tan; Ravi, Kavitha; Selezneva, Julia; Srinivas, Vijaya; Arun, Anjali; Klausner, Jeffrey D
Strategy, Management and Health PolicyEnabling Technology, Genomics, ProteomicsPreclinical ResearchPreclinical Development Toxicology, Formulation Drug Delivery, PharmacokineticsClinical Development Phases I-III Regulatory, Quality, ManufacturingPostmarketing Phase IV There is an increasing need for the standardization of platelet function and coagulation testing for the assessment of antithrombotic therapies. Investigators continue to strive to identify ideal laboratory testing and monitoring procedures for acquired and inherited platelet function defects as well as for evaluating patient status when treated with existing or emerging antithrombotics. These therapies are used primarily in the treatment of ischemic complications. In patients receiving antithrombotic therapy, the balance between hemostasis and thrombosis is a challenge as there is an ongoing risk for bleeding when patients are receiving antiplatelet agents or anticoagulants to lessen their risk for secondary thrombotic events. There are several diverse tests for monitoring anticoagulant therapy; however, as new agents are developed, more specific tests will be required to directly assess these agents in relationship to overall coagulation status. Research in the platelet biology field is ongoing to provide point-of-care methodologies for the assessment of platelet reactivity in terms of both bleeding and thrombosis risk. Currently there are no instruments that reliably assess the risk of bleeding. The challenges that routinely faced are the complexity of physiology, the need for standardization of platelet testing methodology, and the necessity for appropriate interpretation of the test results. PMID:24489427
Jennings, Lisa K; Kotha, Jayaprakash
There is an urgent need for the development of serodiagnostic approaches with improved sensitivity for patients with acute leptospirosis. Immunoblots were performed on 188 sera collected from 74 patients with laboratory-confirmed early leptospiral infection to detect immunoglobulin M (IgM) antibodies to antigens pooled from 10 leptospiral strains prevalent in Thailand. Sera from patients with other febrile diseases served as controls. IgM reactivity to seven distinct antigens, with apparent molecular masses of 14 to 18, 19 to 23, 24 to 30, 32, 35/36, 37, and 41/42 kDa, was observed. The low-molecular-mass 14- to 18-kDa band was the most frequently detected antigen, being recognized in sera from 82.4% of patients during the first 3 days after the onset of symptoms. We evaluated the accuracy of the IgM immunoblot (IgM-IB) test by using reactivity to the 14- to 18-kDa band and/or at least two bands among the 19- to 23-, 24- to 30-, 32-, 35/36-, 37-, and 41/42-kDa antigens as the diagnostic criterion. The sensitivities of the IgM-IB test and the microscopic agglutination test (MAT) were 88.2% and 2.0%, respectively, with sera from patients 1 to 3 days after the onset of symptoms. In contrast, the IgM-IB test was positive with only 2/48 (4.2%) sera from patients with other febrile illnesses. The high sensitivity and specificity of the IgM-IB test for acute leptospirosis would provide greatly improved diagnostic accuracy for identification of patients who would benefit from early antibiotic intervention. In addition, the antigens identified by the IgM-IB test may serve as components of a rapid, accurate, point-of-care diagnostic test for early leptospirosis. PMID:18184827
Doungchawee, Galayanee; Kositanont, Uraiwan; Niwetpathomwat, Anuchai; Inwisai, Tasanee; Sagarasaeranee, Plyyonk; Haake, David A
Since September 2010, more than 10,000 patients have undergone preemptive, panel-based pharmacogenomic testing through the Vanderbilt Pharmacogenomic Resource for Enhanced Decisions in Care and Treatment program. Analysis of the genetic data from the first 9,589 individuals reveals that the frequency of genetic variants is concordant with published allele frequencies. Based on five currently implemented drug-gene interactions, the multiplexed test identified one or more actionable variants in 91% of the genotyped patients and in 96% of African American patients. Using medication exposure data from electronic medical records, we compared a theoretical "reactive," prescription-triggered, serial single-gene testing strategy with our preemptive, multiplexed genotyping approach. Reactive genotyping would have generated 14,656 genetic tests. These data highlight three advantages of preemptive genotyping: (i) the vast majority of patients carry at least one pharmacogenetic variant; (ii) data are available at the point of care; and (iii) there is a substantial reduction in testing burden compared with a reactive strategy. PMID:24253661
Van Driest, S L; Shi, Y; Bowton, E A; Schildcrout, J S; Peterson, J F; Pulley, J; Denny, J C; Roden, D M
2% of the world's population lives with a hepatitis C virus (HCV) infection with highest rates in developing countries. The most common mode of transmission takes place via unsafe blood transfusions and unsafe therapeutic injections. Thus, screening potential blood donors for hepatitis C infection is a must to ensure safe blood transfusions. Rapid immunochromatographic tests are the best suitable test format to be used for screening for blood donors in resource-limited settings. The ImmunoFlow HCV from Core Diagnostics was evaluated at the Paul-Ehrlich-Institute, Germany for its test accuracy on three seropanels. Panel 1 consisted of 26 HCV positive and 55 negative samples, panel 2 of 193 HCV positive samples. Panel 3 contained 116 samples of 10 patients during seroconversion period. 39 of these 116 samples were characterized as HCV positive. The HCV ImmunoFlow had a sensitivity of 100% (95% CI: 93.5-100) and a specificity of 100% (95% CI: 86.8-100) when samples of panel 1 were tested. 191 samples of the 193 samples in panel 2 were correctly by the HCV Immunoflow, resulting in a sensitivity of 99.0%. 9 of 10 HCV infections were detected by the HCV ImmunoFlow when panel 3 was used. This evaluation revealed good sensitivity of the HCV ImmunoFlow test from and compares favorably with the results from the WHO evaluation and a systematic review conducted of field evaluations of Hepatitis C rapid diagnostic and other point of care tests. PMID:24726704
Kosack, Cara S; Nick, Sigrid; Shanks, Leslie
Although simple and low-cost interventions for sickle cell disease (SCD) exist in many developing countries, child mortality associated with SCD remains high, in part, because of the lack of access to diagnostic tests for SCD. A density-based test using aqueous multiphase systems (SCD-AMPS) is a candidate for a low-cost, point-of-care diagnostic for SCD. In this paper, the field evaluation of SCD-AMPS in a large (n?=?505) case-control study in Zambia is described. Of the two variations of the SCD-AMPS used, the best system (SCD-AMPS-2) demonstrated a sensitivity of 86% (82–90%) and a specificity of 60% (53–67%). Subsequent analysis identified potential sources of false positives that include clotting, variation between batches of SCD-AMPS, and shipping conditions. Importantly, SCD-AMPS-2 was 84% (62–94%) sensitive in detecting SCD in children between 6 months and 1 year old. In addition to an evaluation of performance, an assessment of end-user operability was done with health workers in rural clinics in Zambia. These health workers rated the SCD-AMPS tests to be as simple to use as lateral flow tests for malaria and HIV. PMID:25490722
Hennek, Jonathan W.; Mantina, Hamakwa; Lee, S. Y. Ryan; Patton, Matthew R.; Sambo, Pauline; Sinyangwe, Silvester; Kankasa, Chipepo; Chintu, Chifumbe; Brugnara, Carlo; Stossel, Thomas P.; Whitesides, George M.
Passive exposure to tobacco smoke causes a variety of illnesses ranging from allergic responses to cancer. Assessment of exposure to second-hand tobacco smoke (SHS), particularly among vulnerable populations enables intervention and prevention of future disease. A minimally invasive oral fluids-based onsite test to detect such exposure would create a valuable tool for researchers and clinicians. Here we describe the development of a test that uses an inexpensive reader that utilizes a CMOS image sensor to reliably quantify a reporter signal and determine nicotine exposure. The rapid lateral flow test consists of a nitrocellulose strip with a control line containing goat anti-rabbit IgG, used as an internal standard, and a test line containing BSA-cotinine conjugate. To run the test, diluted sample containing antibodies against cotinine, the major metabolite of nicotine, is mixed with protein A-gold nanoparticles and placed on the sample pad. As the sample runs up to the nitrocellulose pad, antibodies in the running buffer bind to available cotinine. If cotinine is absent, the antibodies will bind to the BSA-cotinine derivative immobilized on the test line, resulting in an intense purple-red band. The concentration of cotinine equivalents in the sample can be estimated from interpretation of the test line. In this article we describe the effect of different cotinine derivatives, oral fluid pretreatment, and application and running buffers on assay sensitivity. The test can reliably detect as little as 2 ng mL(-1) cotinine equivalents. The assay is sensitive, simple, rapid, inexpensive, and easily implementable in point-of-care facilities to detect second-hand smoke exposure. PMID:21556750
Gonzalez, Jesus M; Foley, Michael W; Bieber, Natalie M; Bourdelle, Peter A; Niedbala, R Sam
Tests that detect Mycobacterium tuberculosis antigens in clinical specimens could provide rapid direct evidence of active disease. We performed a systematic review to assess the diagnostic accuracy of antigen detection tests for active tuberculosis (TB) according to standard methods and summarized test performance using bivariate random effects meta-analysis. Overall, study quality was a concern. For pulmonary TB (47 studies, 5,036 participants), sensitivity estimates ranged from 2% to 100% and specificity from 33% to 100%. Lipoarabinomannan (LAM) was the antigen most frequently targeted (23 studies, 49%). The pooled sensitivity of urine LAM was higher in HIV-infected than HIV-uninfected individuals (47%; 95% confidence interval [CI], 26 to 68% versus 14%; 95% CI, 4 to 38%); pooled specificity estimates were similar: 96%; 95% CI, 81 to 100% and 97%; 95% CI, 86 to 100%, respectively. For extrapulmonary TB (21 studies, 1,616 participants), sensitivity estimates ranged from 0% to 100% and specificity estimates from 62% to 100%. Five studies targeting LAM, ESAT-6, Ag85 complex, and the 65-kDa antigen in cerebrospinal fluid, when pooled, yielded the highest sensitivity (87%; 95% CI, 61 to 98%), but low specificity (84%; 95% CI, 60 to 95%). Because of the limited number of studies targeting any specific antigen other than LAM, we could not draw firm conclusions about the overall clinical usefulness of these tests. Further studies are warranted to determine the value of LAM detection for TB meningitis in high-HIV-prevalence settings. Considering that antigen detection tests could be translated into rapid point-of-care tests, research to improve their performance is urgently needed. PMID:21832100
Flores, L. L.; Steingart, K. R.; Dendukuri, N.; Schiller, I.; Minion, J.; Pai, M.; Ramsay, A.; Henry, M.; Laal, S.
Rapid point-of-care detection of enteric protozoa in diarrheal stool is desirable in clinical and research settings to efficiently determine the etiology of diarrhea. We analyzed the ability of the third-generation E. histolytica Quik Chek assay developed by Techlab to detect amebic antigens in fecal samples collected from independent study populations in South Africa and Bangladesh. We compared the performance of this recently released rapid test to that of the commercially available ProSpecT Entamoeba histolytica microplate assay from Remel and the E. histolytica II enzyme-linked immunosorbent assay (ELISA) from Techlab, using real-time and nested-PCR for Entamoeba species to resolve any discrepant results. After discrepant resolution, The E. histolytica Quik Chek assay exhibited sensitivity and specificity compared to the E. histolytica II ELISA of 98.0% (95% confidence interval [CI], 92.9% to 99.8%) and 100% (95% CI, 99.0% to 100%), respectively. Compared to the ProSpecT microplate assay, the E. histolytica Quik Chek (Quik Chek) assay exhibited 97.0% sensitivity (95% CI, 91.5% to 99.4%) and 100% specificity (95% CI, 99.0% to 100%). Our results indicate that the Quik Chek is a robust assay for the specific detection of E. histolytica trophozoites in unfixed frozen clinical stool samples. PMID:25428152
Verkerke, Hans P; Hanbury, Blake; Siddique, Abdullah; Samie, Amidou; Haque, Rashidul; Herbein, Joel; Petri, William A
We have developed a portable breath acetone analyzer using cavity ringdown spectroscopy (CRDS). The instrument was initially tested by measuring the absorbance of breath gases at a single wavelength (266 nm) from 32 human subjects under various conditions. A background subtraction method, implemented to obtain absorbance differences, from which an upper limit of breath acetone concentration was obtained, is described. The upper limits of breath acetone concentration in the four Type 1 diabetes (T1D) subjects, tested after a 14 h overnight fast, range from 0.80 to 3.97 parts per million by volume (ppmv), higher than the mean acetone concentration (0.49 ppmv) in non-diabetic healthy breath reported in the literature. The preliminary results show that the instrument can tell distinctive differences between the breath from individuals who are healthy and those with T1D. On-line monitoring of breath gases in healthy people post-exercise, post-meals and post-alcohol-consumption was also conducted. This exploratory study demonstrates the first CRDS-based acetone breath analyzer and its potential application for point-of-care, non-invasive, diabetic monitoring.
Wang, Chuji; Surampudi, Anand B.