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Sample records for 1-year repeat mri

  1. Automated mapping of hippocampal atrophy in 1-year repeat MRI data from 490 subjects with Alzheimer's disease, mild cognitive impairment, and elderly controls.

    PubMed

    Morra, Jonathan H; Tu, Zhuowen; Apostolova, Liana G; Green, Amity E; Avedissian, Christina; Madsen, Sarah K; Parikshak, Neelroop; Toga, Arthur W; Jack, Clifford R; Schuff, Norbert; Weiner, Michael W; Thompson, Paul M

    2009-03-01

    As one of the earliest structures to degenerate in Alzheimer's disease (AD), the hippocampus is the target of many studies of factors that influence rates of brain degeneration in the elderly. In one of the largest brain mapping studies to date, we mapped the 3D profile of hippocampal degeneration over time in 490 subjects scanned twice with brain MRI over a 1-year interval (980 scans). We examined baseline and 1-year follow-up scans of 97 AD subjects (49 males/48 females), 148 healthy control subjects (75 males/73 females), and 245 subjects with mild cognitive impairment (MCI; 160 males/85 females). We used our previously validated automated segmentation method, based on AdaBoost, to create 3D hippocampal surface models in all 980 scans. Hippocampal volume loss rates increased with worsening diagnosis (normal=0.66%/year; MCI=3.12%/year; AD=5.59%/year), and correlated with both baseline and interval changes in Mini-Mental State Examination (MMSE) scores and global and sum-of-boxes Clinical Dementia Rating scale (CDR) scores. Surface-based statistical maps visualized a selective profile of ongoing atrophy in all three diagnostic groups. Healthy controls carrying the ApoE4 gene atrophied faster than non-carriers, while more educated controls atrophied more slowly; converters from MCI to AD showed faster atrophy than non-converters. Hippocampal loss rates can be rapidly mapped, and they track cognitive decline closely enough to be used as surrogate markers of Alzheimer's disease in drug trials. They also reveal genetically greater atrophy in cognitively intact subjects.

  2. A chronic 1 year assessment of MRI contrast agent-labelled neural stem cell transplants in stroke.

    PubMed

    Modo, M; Beech, J S; Meade, T J; Williams, S C R; Price, J

    2009-08-01

    Non-invasive identification of transplanted neural stem cells in vivo by pre-labelling with contrast agents may play an important role in the translation of cell therapy to the clinic. Understanding the impact of these labels on the cells' ability to repair is therefore vital. In rats with middle cerebral artery occlusion (MCAo), a model of stroke, the transhemispheric migration of MHP36 cells labelled with the bimodal contrast agent GRID was detected on magnetic resonance images (MRI) up to 4 weeks following transplantation. However, compared to MHP36 cells labelled with the red fluorescent dye PKH26, GRID-labelled transplants did not significantly improve behaviour, and performance was akin to non-treated animals. Likewise, the evolution of anatomical damage as assessed by serial, T(2)-weighted MRI over 1 year indicated that GRID-labelled transplants resulted in a slight increase in lesion size compared to MCAo-only animals, whereas the same, PKH26-labelled cells significantly decreased lesion size by 35%. Although GRID labelling allows the in vivo identification of transplanted cells up to 1 month after transplantation, it is likely that some is gradually degraded inside cells. The translation of cellular imaging therefore does not only require the in vitro assessment of contrast agents on cellular functions, but also requires the chronic, in vivo assessment of the label on the stem cells' ability to repair in preclinical models of neurological disease. PMID:18634886

  3. Are early MRI findings correlated with long-lasting symptoms following whiplash injury? A prospective trial with 1-year follow-up

    PubMed Central

    Sorensen, Joan S.; Andersen, Hans; Keseler, Bjarne; Jensen, Troels S.; Bendix, Tom

    2008-01-01

    Neck pain is the cardinal symptom following whiplash injuries. The trauma mechanism could theoretically lead to both soft tissue and bone injury that could be visualised by means of MRI. From previous quite small trials it seems that MRI does not demonstrate significant tissue damage. Large prospectively followed cohorts are needed to identify possible clinically relevant MRI findings. The objective of this trial was to evaluate (1) the predictive value of cervical MRI after whiplash injuries and (2) the value of repeating MRI examinations after 3 months including sequences with flexion and extension of the cervical spine. Participants were included after rear-end or frontal car collisions. Patients with fractures or dislocations diagnosed by standard procedures at the emergency unit were not included. MRI scans of the cervical spine were performed at baseline and repeated after 3 months. Clinical follow-ups were performed after 3 and 12 months. Outcome parameters were neck pain, headache, neck disability and working ability. A total of 178 participants had a cervical MRI scan on average 13 days after the injury. Traumatic findings were observed in seven participants. Signs of disc degeneration were common and most frequent at the C5–6 and C6–7 levels. Findings were not associated with outcome after 3 or 12 months. The population had no considerable neck trouble prior to the whiplash injury and the non-traumatic findings represent findings to be expected in the background population. Trauma-related MRI findings are rare in a whiplash population screened for serious injuries in the emergency unit and not related to a specific symptomatology. Also, pre-existing degeneration is not associated with prognosis. PMID:18512085

  4. Repeatability of Cerebral Perfusion Using Dynamic Susceptibility Contrast MRI in Glioblastoma Patients12

    PubMed Central

    Jafari-Khouzani, Kourosh; Emblem, Kyrre E.; Kalpathy-Cramer, Jayashree; Bjørnerud, Atle; Vangel, Mark G.; Gerstner, Elizabeth R.; Schmainda, Kathleen M.; Paynabar, Kamran; Wu, Ona; Wen, Patrick Y.; Batchelor, Tracy; Rosen, Bruce; Stufflebeam, Steven M.

    2015-01-01

    OBJECTIVES This study evaluates the repeatability of brain perfusion using dynamic susceptibility contrast magnetic resonance imaging (DSC-MRI) with a variety of post-processing methods. METHODS Thirty-two patients with newly diagnosed glioblastoma were recruited. On a 3-T MRI using a dual-echo, gradient-echo spin-echo DSC-MRI protocol, the patients were scanned twice 1 to 5 days apart. Perfusion maps including cerebral blood volume (CBV) and cerebral blood flow (CBF) were generated using two contrast agent leakage correction methods, along with testing normalization to reference tissue, and application of arterial input function (AIF). Repeatability of CBV and CBF within tumor regions and healthy tissues, identified by structural images, was assessed with intra-class correlation coefficients (ICCs) and repeatability coefficients (RCs). Coefficients of variation (CVs) were reported for selected methods. RESULTS CBV and CBF were highly repeatable within tumor with ICC values up to 0.97. However, both CBV and CBF showed lower ICCs for healthy cortical tissues (up to 0.83), healthy gray matter (up to 0.95), and healthy white matter (WM; up to 0.93). The values of CV ranged from 6% to 10% in tumor and 3% to 11% in healthy tissues. The values of RC relative to the mean value of measurement within healthy WM ranged from 22% to 42% in tumor and 7% to 43% in healthy tissues. These percentages show how much variation in perfusion parameter, relative to that in healthy WM, we expect to observe to consider it statistically significant. We also found that normalization improved repeatability, but AIF deconvolution did not. CONCLUSIONS DSC-MRI is highly repeatable in high-grade glioma patients. PMID:26055170

  5. Reproducibility of Brain Morphometry from Short-Term Repeat Clinical MRI Examinations: A Retrospective Study

    PubMed Central

    Liu, Hon-Man; Chen, Shan-Kai; Chen, Ya-Fang; Lee, Chung-Wei; Yeh, Lee-Ren

    2016-01-01

    Purpose To assess the inter session reproducibility of automatic segmented MRI-derived measures by FreeSurfer in a group of subjects with normal-appearing MR images. Materials and Methods After retrospectively reviewing a brain MRI database from our institute consisting of 14,758 adults, those subjects who had repeat scans and had no history of neurodegenerative disorders were selected for morphometry analysis using FreeSurfer. A total of 34 subjects were grouped by MRI scanner model. After automatic segmentation using FreeSurfer, label-wise comparison (involving area, thickness, and volume) was performed on all segmented results. An intraclass correlation coefficient was used to estimate the agreement between sessions. Wilcoxon signed rank test was used to assess the population mean rank differences across sessions. Mean-difference analysis was used to evaluate the difference intervals across scanners. Absolute percent difference was used to estimate the reproducibility errors across the MRI models. Kruskal-Wallis test was used to determine the across-scanner effect. Results The agreement in segmentation results for area, volume, and thickness measurements of all segmented anatomical labels was generally higher in Signa Excite and Verio models when compared with Sonata and TrioTim models. There were significant rank differences found across sessions in some labels of different measures. Smaller difference intervals in global volume measurements were noted on images acquired by Signa Excite and Verio models. For some brain regions, significant MRI model effects were observed on certain segmentation results. Conclusions Short-term scan-rescan reliability of automatic brain MRI morphometry is feasible in the clinical setting. However, since repeatability of software performance is contingent on the reproducibility of the scanner performance, the scanner performance must be calibrated before conducting such studies or before using such software for retrospective

  6. Repeated BOLD-fMRI imaging of deep brain stimulation responses in rats.

    PubMed

    Chao, Tzu-Hao Harry; Chen, Jyh-Horng; Yen, Chen-Tung

    2014-01-01

    Functional magnetic resonance imaging (fMRI) provides a picture of the global spatial activation pattern of the brain. Interest is growing regarding the application of fMRI to rodent models to investigate adult brain plasticity. To date, most rodent studies used an electrical forepaw stimulation model to acquire fMRI data, with α-chloralose as the anesthetic. However, α-chloralose is harmful to animals, and not suitable for longitudinal studies. Moreover, peripheral stimulation models enable only a limited number of brain regions to be studied. Processing between peripheral regions and the brain is multisynaptic, and renders interpretation difficult and uncertain. In the present study, we combined the medetomidine-based fMRI protocol (a noninvasive rodent fMRI protocol) with chronic implantation of an MRI-compatible stimulation electrode in the ventroposterior (VP) thalamus to repetitively sample thalamocortical responses in the rat brain. Using this model, we scanned the forebrain responses evoked by the VP stimulation repeatedly of individual rats over 1 week. Cortical BOLD responses were compared between the 2 profiles obtained at day1 and day8. We discovered reproducible frequency- and amplitude-dependent BOLD responses in the ipsilateral somatosensory cortex (S1). The S1 BOLD responses during the 2 sessions were conserved in maximal response amplitude, area size (size ratio from 0.88 to 0.91), and location (overlap ratio from 0.61 to 0.67). The present study provides a long-term chronic brain stimulation protocol for studying the plasticity of specific neural circuits in the rodent brain by BOLD-fMRI. PMID:24825464

  7. Evaluation of T2-weighted and dynamic contrast-enhanced MRI in localizing prostate cancer before repeat biopsy.

    PubMed

    Cheikh, Alexandre Ben; Girouin, Nicolas; Colombel, Marc; Maréchal, Jean-Marie; Gelet, Albert; Bissery, Alvine; Rabilloud, Muriel; Lyonnet, Denis; Rouvière, Olivier

    2009-03-01

    We assessed the accuracy of T2-weighted (T2w) and dynamic contrast-enhanced (DCE) 1.5-T magnetic resonance imaging (MRI) in localizing prostate cancer before transrectal ultrasound-guided repeat biopsy. Ninety-three patients with abnormal PSA level and negative prostate biopsy underwent T2w and DCE prostate MRI using pelvic coil before repeat biopsy. T2w and DCE images were interpreted using visual criteria only. MR results were correlated with repeat biopsy findings in ten prostate sectors. Repeat biopsy found prostate cancer in 23 patients (24.7%) and 44 sectors (6.6%). At per patient analysis, the sensitivity, specificity, positive and negative predictive values were 47.8%, 44.3%, 20.4% and 79.5% for T2w imaging and 82.6%, 20%, 24.4% and 93.3% for DCE imaging. When all suspicious areas (on T2w or DCE imaging) were taken into account, a sensitivity of 82.6% and a negative predictive value of 100% could be achieved. At per sector analysis, DCE imaging was significantly less specific (83.5% vs. 89.7%, p < 0.002) than T2w imaging; it was more sensitive (52.4% vs. 32.1%), but the difference was hardly significant (p = 0.09). T2w and DCE MRI using pelvic coil and visual diagnostic criteria can guide prostate repeat biopsy, with a good sensitivity and NPV.

  8. Reliability of Early Magnetic Resonance Imaging (MRI) and Necessity of Repeating MRI in Noncooled and Cooled Infants With Neonatal Encephalopathy.

    PubMed

    Chakkarapani, Elavazhagan; Poskitt, Kenneth J; Miller, Steven P; Zwicker, Jill G; Xu, Qi; Wong, Darren S T; Roland, Elke H; Hill, Alan; Chau, Vann

    2016-04-01

    In cooled newborns with encephalopathy, although late magnetic resonance imaging (MRI) scan (10-14 days of age) is reliable in predicting long-term outcome, it is unknown whether early scan (3-6 days of life) is. We compared the predominant pattern and extent of lesion between early and late MRI in 89 term neonates with neonatal encephalopathy. Forty-three neonates (48%) were cooled. The predominant pattern of lesions and the extent of lesion in the watershed region agreed near perfectly in noncooled (kappa = 0.94; k = 0.88) and cooled (k = 0.89; k = 0.87) infants respectively. There was perfect agreement in the extent of lesion in the basal nuclei in noncooled infants (k = 0.83) and excellent agreement in cooled infants (k = 0.67). Changes in extent of lesions on late MRI occurred in 19 of 89 infants, with higher risk in infants with hypoglycemia and moderate-severe lesions in basal nuclei. In most term neonates with neonatal encephalopathy, early MRI (relative to late scan) robustly predicts the predominant pattern and extent of injury.

  9. Traumatic spinal epidural hematoma in a 1-year-old boy.

    PubMed

    Tarbé de Saint Hardouin, A-L; Grévent, D; Sainte-Rose, C; Angoulvant, F; Chéron, G

    2016-07-01

    Traumatic spinal epidural hematoma is uncommon in children, making rapid diagnosis difficult. In this report, we present a case of traumatic cervical epidural hematoma in a 1-year-old boy, diagnosed with computed tomography scanning and magnetic resonance imaging (MRI). Management was conservative and the lesion regressed spontaneously. The presentation in childhood is often nonspecific. MRI is the imaging modality of choice for diagnosing these lesions. Conservative treatment has to be considered in cases with a benign clinical course and provided that the patient is followed up neurologically with repeated MRI.

  10. Human dermal matrix scaffold augmentation for large and massive rotator cuff repairs: preliminary clinical and MRI results at 1-year follow-up.

    PubMed

    Rotini, Roberto; Marinelli, Alessandro; Guerra, Enrico; Bettelli, Graziano; Castagna, Alessandro; Fini, Milena; Bondioli, Elena; Busacca, Maurizio

    2011-07-01

    The high incidence of recurrent tendon tears after repair of massive cuff lesions is prompting the research of materials aimed at mechanically or biologically reinforcing the tendon. Among the materials studied upto now, the extracellular matrix (ECM) scaffolds of human origin have proved to be the safest and most efficient, but the current laws about grafts and transplants preclude their use in Europe. In order to overcome this condition in 2006, we started a project regarding the production of an ECM scaffold of human origin which could be implanted in Europe too. In 2009, the clinical study began with the implantation of dermal matrix scaffolds in 7 middle-aged patients affected with large/massive cuff lesions and tendon degeneration. Out of 5 cases, followed for at least 1 year in which the scaffold was employed as an augmentation device, there were 3 patients with complete healing, 1 partial re-tear, and 1 total recurrence. The absence of adverse inflammatory or septic complications allows to continue this line of research with a prospective controlled study in order to define the real advantages and correct indications offered by scaffold application. PMID:21691735

  11. In Emergency Department Patients with Acute Chest Pain, Stress Cardiac MRI Observation Unit Care Reduces 1- year Cardiac-Related Health Care Expenditures: A Randomized Trial

    PubMed Central

    Miller, Chadwick D.; Hwang, Wenke; Case, Doug; Hoekstra, James W.; Lefebvre, Cedric; Blumstein, Howard; Hamilton, Craig A.; Harper, Erin N.; Hundley, W. Gregory

    2013-01-01

    Objective To compare the direct cost of medical care and clinical events during the first year after patients with intermediate risk acute chest pain were randomized to stress cardiovascular magnetic resonance (CMR) observation unit (OU) testing, versus inpatient care. Background In a recent study, randomization to OU-CMR reduced median index hospitalization cost compared to inpatient care in patients presenting to the emergency department with intermediate risk acute chest pain. Methods Emergency department patients with intermediate risk chest pain were randomized to OU-CMR (OU care, cardiac markers, stress CMR) or inpatient care (admission, care per admitting provider). This analysis reports the direct cost of cardiac-related care and clinical outcomes (MI, revascularization, cardiovascular death) during the first year of follow-up subsequent to discharge. Consistent with health economics literature, provider cost was calculated from work-related relative value units using the Medicare conversion factor; facility charges were converted to cost using departmental specific cost-to-charge ratios. Linear models were used to compare cost accumulation among study groups. Results One-hundred nine (109) randomized subjects were included in this analysis (52 OU-CMR, 57 inpatient care). The median age was 56 years; baseline characteristics were similar in both groups. At 1 year, 6% of OU-CMR and 9% of inpatient care participants experienced a major cardiac event (p=0.72) with 1 patient in each group experiencing a cardiac event after discharge. First-year cardiac-related costs were significantly lower for participants randomized to OU-CMR compared to participants receiving inpatient care (geometric mean = $3101 vs $4742 including the index visit (p = .004) and $29 vs $152 following discharge (p = .012)). During the year following randomization, 6% of OU-CMR and 9% of inpatient care participants experienced a major cardiac event (p=0.72). Conclusions An OU-CMR strategy

  12. Cognitive control mechanisms revealed by ERP and fMRI: evidence from repeated task-switching.

    PubMed

    Swainson, R; Cunnington, R; Jackson, G M; Rorden, C; Peters, A M; Morris, P G; Jackson, S R

    2003-08-15

    We investigated the extent to which a common neural mechanism is involved in task set-switching and response withholding, factors that are frequently confounded in task-switching and go/no-go paradigms. Subjects' brain activity was measured using event-related electrical potentials (ERPs) and event-related functional MRI (fMRI) neuroimaging in separate studies using the same cognitive paradigm. Subjects made compatible left/right keypress responses to left/right arrow stimuli of 1000 msec duration; they switched every two trials between responding at stimulus onset (GO task-green arrows) and stimulus offset (WAIT task-red arrows). With-holding an immediate response (WAIT vs. GO) elicited an enhancement of the frontal N2 ERP and lateral PFC activation of the right hemisphere, both previously associated with the "no-go" response, but only on switch trials. Task-switching (switch vs. nonswitch) was associated with frontal N2 amplification and right hemisphere ventrolateral PFC activation, but only for the WAIT task. The anterior cingulate cortex (ACC) was the only brain region to be activated for both types of task switch, but this activation was located more rostrally for the WAIT than for the GO switch trials. We conclude that the frontal N2 ERP and lateral PFC activation are not markers for withholding an immediate response or switching tasks per se, but are associated with switching into a response-suppression mode. Different regions within the ACC may be involved in two processes integral to task-switching: processing response conflict (rostral ACC) and overcoming prior response suppression (caudal ACC).

  13. MRI

    MedlinePlus

    MRI does not use ionizing radiation. No side effects from the magnetic fields and radio waves have been reported. The most common type of contrast (dye) used is gadolinium. It is very safe. Allergic reactions rarely ...

  14. Hyperintense Dentate Nuclei on T1-Weighted MRI: Relation to Repeat Gadolinium Administration

    PubMed Central

    Adin, M.E.; Kleinberg, L.; Vaidya, D.; Zan, E.; Mirbagheri, S.; Yousem, D.M.

    2016-01-01

    BACKGROUND AND PURPOSE A hyperintense appearance of the dentate nucleus on T1-weighted MR images has been related to various clinical conditions, but the etiology remains indeterminate. We aimed to investigate the possible associations between a hyperintense appearance of the dentate nucleus on T1-weighted MR images in patients exposed to radiation and factors including, but not limited to, the cumulative number of contrast-enhanced MR images, amount of gadolinium administration, dosage of ionizing radiation, and patient demographics. MATERIALS AND METHODS The medical records of 706 consecutive patients who were treated with brain irradiation at The Johns Hopkins Medical Institutions between 1995 and 2010 were blindly reviewed by 2 readers. RESULTS One hundred eighty-four subjects were included for dentate nuclei analysis. Among the 184 subjects who cumulatively underwent 2677 MR imaging studies following intravenous gadolinium administration, 103 patients had hyperintense dentate nuclei on precontrast T1-weighted MR images. The average number of gadolinium-enhanced MR imaging studies performed in the group with normal dentate nuclei was significantly lower than that of the group with hyperintense dentate nuclei. The average follow-up time was 62.5 months. No significant difference was observed between hyperintense and normal dentate nuclei groups in terms of exposed radiation dose, serum creatinine and calcium/phosphate levels, patient demographics, history of chemotherapy, and strength of the scanner. No dentate nuclei abnormalities were found on the corresponding CT scans of patients with hyperintense dentate nuclei (n = 44). No dentate nuclei abnormalities were found in 53 healthy volunteers. CONCLUSIONS Repeat performance of gadolinium-enhanced studies likely contributes to a long-standing hyperintense appearance of dentate nuclei on precontrast T1-weighted-MR images. PMID:26294649

  15. The Prostate Health Index adds predictive value to multi-parametric MRI in detecting significant prostate cancers in a repeat biopsy population

    PubMed Central

    Gnanapragasam, V. J.; Burling, K.; George, A.; Stearn, S.; Warren, A.; Barrett, T.; Koo, B.; Gallagher, F. A.; Doble, A.; Kastner, C.; Parker, R. A.

    2016-01-01

    Both multi-parametric MRI (mpMRI) and the Prostate Health Index (PHI) have shown promise in predicting a positive biopsy in men with suspected prostate cancer. Here we investigated the value of combining both tests in men requiring a repeat biopsy. PHI scores were measured in men undergoing re-biopsy with an mpMRI image-guided transperineal approach (n = 279, 94 with negative mpMRIs). The PHI was assessed for ability to add value to mpMRI in predicting all or only significant cancers (Gleason ≥7). In this study adding PHI to mpMRI improved overall and significant cancer prediction (AUC 0.71 and 0.75) compared to mpMRI + PSA alone (AUC 0.64 and 0.69 respectively). At a threshold of ≥35, PHI + mpMRI demonstrated a NPV of 0.97 for excluding significant tumours. In mpMRI negative men, the PHI again improved prediction of significant cancers; AUC 0.76 vs 0.63 (mpMRI + PSA). Using a PHI≥35, only 1/21 significant cancers was missed and 31/73 (42%) men potentially spared a re-biopsy (NPV of 0.97, sensitivity 0.95). Decision curve analysis demonstrated clinically relevant utility of the PHI across threshold probabilities of 5–30%. In summary, the PHI adds predictive performance to image-guided detection of clinically significant cancers and has particular value in determining re-biopsy need in men with a negative mpMRI. PMID:27748407

  16. Comparison of prostate MRI-3D transrectal ultrasound fusion biopsy for first-time and repeat biopsy patients with previous atypical small acinar proliferation

    PubMed Central

    Cool, Derek W.; Romagnoli, Cesare; Izawa, Jonathan I.; Chin, Joseph; Gardi, Lori; Tessier, David; Mercado, Ashley; Mandel, Jonathan; Ward, Aaron D.; Fenster, Aaron

    2016-01-01

    Introduction: This study evaluates the clinical benefit of magnetic resonance-transrectal ultrasound (MR-TRUS) fusion biopsy over systematic biopsy between first-time and repeat prostate biopsy patients with prior atypical small acinar proliferation (ASAP). Materials: 100 patients were enrolled in a single-centre prospective cohort study: 50 for first biopsy, 50 for repeat biopsy with prior ASAP. Multiparameteric magnetic resonance imaging (MP-MRI) and standard 12-core ultrasound biopsy (Std-Bx) were performed on all patients. Targeted biopsy using MRI-TRUS fusion (Fn-Bx) was performed f suspicious lesions were identified on the pre-biopsy MP-MRI. Classification of clinically significant disease was assessed independently for the Std-Bx vs. Fn-Bx cores to compare the two approaches. Results: Adenocarcinoma was detected in 49/100 patients (26 first biopsy, 23 ASAP biopsy), with 25 having significant disease (17 first, 8 ASAP). Fn-Bx demonstrated significantly higher per-core cancer detection rates, cancer involvement, and Gleason scores for first-time and ASAP patients. However, Fn-Bx was significantly more likely to detect significant cancer missed on Std-Bx for ASAP patients than first-time biopsy patients. The addition of Fn-Bx to Std-Bx for ASAP patients had a 166.7% relative risk reduction for missing Gleason ≥ 3 + 4 disease (number needed to image with MP-MRI=10 patients) compared to 6.3% for first biopsy (number to image=50 patients). Negative predictive value of MP-MRI for negative biopsy was 79% for first-time and 100% for ASAP patients, with median followup of 32.1 ± 15.5 months. Conclusions: MR-TRUS Fn-Bx has a greater clinical impact for repeat biopsy patients with prior ASAP than biopsy-naïve patients by detecting more significant cancers that are missed on Std-Bx. PMID:27800057

  17. Diffusion-weighted MRI of breast lesions: a prospective clinical investigation of the quantitative imaging biomarker characteristics of reproducibility, repeatability, and diagnostic accuracy.

    PubMed

    Spick, Claudio; Bickel, Hubert; Pinker, Katja; Bernathova, Maria; Kapetas, Panagiotis; Woitek, Ramona; Clauser, Paola; Polanec, Stephan H; Rudas, Margaretha; Bartsch, Rupert; Helbich, Thomas H; Baltzer, Pascal A

    2016-10-01

    Diffusion-weighted MRI (DWI) provides insights into tissue microstructure by visualization and quantification of water diffusivity. Quantitative evaluation of the apparent diffusion coefficient (ADC) obtained from DWI has been proven helpful for differentiating between malignant and benign breast lesions, for cancer subtyping in breast cancer patients, and for prediction of response to neoadjuvant chemotherapy. However, to further establish DWI of breast lesions it is important to evaluate the quantitative imaging biomarker (QIB) characteristics of reproducibility, repeatability, and diagnostic accuracy. In this intra-individual prospective clinical study 40 consecutive patients with suspicious findings, scheduled for biopsy, underwent an identical 3T breast MRI protocol of the breast on two consecutive days (>24 h). Mean ADC of target lesions was assessed (two independent readers) in four separate sessions. Reproducibility, repeatability, and diagnostic accuracy between examinations (E1, E2), readers (R1, R2), and measurements (M1, M2) were assessed with intraclass correlation coefficients (ICCs), coefficients of variation (CVs), Bland-Altman plots, and receiver operating characteristic (ROC) analysis with calculation of the area under the ROC curve (AUC). The standard of reference was either histopathology (n = 38) or imaging follow-up of up to 24 months (n = 2). Eighty breast MRI examinations (median E1-E2, 2 ± 1.7 days, 95% confidence interval (CI) 1-2 days, range 1-11 days) in 40 patients (mean age 56, standard deviation (SD) ±14) were evaluated. In 55 target lesions (mean size 25.2 ± 20.8 (SD) mm, range 6-106 mm), mean ADC values were significantly (P < 0.0001) higher in benign (1.38, 95% CI 1.27-1.49 × 10(-3)  mm(2) /s) compared with malignant (0.86, 95% CI 0.81-0.91 × 10(-) (3)  mm(2) /s) lesions. Reproducibility and repeatability showed high agreement for repeated examinations, readers, and measurements (all ICCs >0.9, CVs 3

  18. TU-C-12A-05: Repeatability Study of Reduced Field-Of-View Diffusion-Weighted MRI On Human Thyroid Gland

    SciTech Connect

    Shukla-Dave, A; Lu, Y; Hatzoglou, V; Stambuk, H; Mazaheri, Y; Banerjee, S; Shankaranarayanan, A; Deasy, J

    2014-06-15

    Purpose: To investigate the repeatability of reduced field-of-view diffusion-weighted imaging (rFOV DWI) in quantifying apparent diffusion coefficients (ADCs) for human thyroid glands in a clinical setting. Methods: Nine healthy human volunteers were enrolled and underwent 3T MRI exams. For each volunteer, 3 longitudinal exams (2 weeks apart) with 2 repetitive sessions within each exam, including rFOV and conventional full field-of-view (fFOV) DWI scans, were performed. In the acquired DWI images, a fixed-size region of interest (ROI; diameter=8mm) was placed on thyroid glands to calculate ADC. ADC was calculated using a monoexponential function with a noise correction scheme. The repeatability of ADC was assessed by using coefficient variation (CV) across sessions or exams, which was defined to be: r = 1-CV, 0 < r < 1, where CV=STD/m, STD is the standard deviation of ADC, and m is the average of ADC across sessions or exams. An experienced radiologist assessed and scored rFOV and fFOV DW images based on image characteristics (1, nondiagnostic; 2, poor; 3, satisfactory; 4, good; and 5, excellent).Analysis of variance (ANOVA) was performed to compare ADC values, CV of ADC, repeatability of ADC across sessions and exams, and radiologic scores between rFOV and fFOV DWI techniques. Results: There was no significant difference in ADC values across sessions and exams either in rFOV or fFOV DWI. The average CVs of both rFOV and fFOV DWI were less than 13%. The repeatability of ADC measurement between rFOV and fFOV DWI was not significantly different. The overall image quality was significantly higher with rFOV DWI than with fFOV DWI. Conclusion: This study suggested that ADCs from both rFOV and fFOV DWI were repeatable, but rFOV DWI had superior imaging quality for human thyroid glands in a clinical setting.

  19. Discontinuous Patterns of Brain Activation in the Psychotherapy Process of Obsessive-Compulsive Disorder: Converging Results from Repeated fMRI and Daily Self-Reports

    PubMed Central

    Schiepek, Günter; Tominschek, Igor; Heinzel, Stephan; Aigner, Martin; Dold, Markus; Unger, Annemarie; Lenz, Gerhard; Windischberger, Christian; Moser, Ewald; Plöderl, Martin; Lutz, Jürgen; Meindl, Thomas; Zaudig, Michael; Pogarell, Oliver; Karch, Susanne

    2013-01-01

    This study investigates neuronal activation patterns during the psychotherapeutic process, assuming that change dynamics undergo critical instabilities and discontinuous transitions. An internet-based system was used to collect daily self-assessments during inpatient therapies. A dynamic complexity measure was applied to the resulting time series. Critical phases of the change process were indicated by the maxima of the varying complexity. Repeated functional magnetic resonance imaging (fMRI) measurements were conducted over the course of the therapy. The study was realized with 9 patients suffering from obsessive-compulsive disorder (subtype: washing/contamination fear) and 9 matched healthy controls. For symptom-provocative stimulation individualized pictures from patients’ personal environments were used. The neuronal responses to these disease-specific pictures were compared to the responses during standardized disgust-provoking and neutral pictures. Considerably larger neuronal changes in therapy-relevant brain areas (cingulate cortex/supplementary motor cortex, bilateral dorsolateral prefrontal cortex, bilateral insula, bilateral parietal cortex, cuneus) were observed during critical phases (order transitions), as compared to non-critical phases, and also compared to healthy controls. The data indicate that non-stationary changes play a crucial role in the psychotherapeutic process supporting self-organization and complexity models of therapeutic change. PMID:23977168

  20. Emotional Development: 1 Year Olds

    MedlinePlus

    ... Español Text Size Email Print Share Emotional Development: 1 Year Olds Page Content Article Body Throughout her ... for shelter. She may seem to change from one moment to the next, or she may seem ...

  1. Social Development: 1 Year Olds

    MedlinePlus

    ... Stages Prenatal Baby Toddler Fitness Nutrition Toilet Training Preschool Gradeschool Teen Young Adult Healthy Children > Ages & Stages > Toddler > Social Development: 1 Year Olds Ages & Stages Listen Español ...

  2. Heart MRI

    MedlinePlus

    Magnetic resonance imaging - cardiac; Magnetic resonance imaging - heart; Nuclear magnetic resonance - cardiac; NMR - cardiac; MRI of the heart; Cardiomyopathy - MRI; Heart failure - MRI; Congenital heart disease - MRI

  3. Head MRI

    MedlinePlus

    ... the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head ... the test, tell your provider if you have: Brain aneurysm clips An artificial heart valves Heart defibrillator ...

  4. An exploratory intervention study suggests clinical benefits of training in chronic stroke to be paralleled by changes in brain activity using repeated fMRI

    PubMed Central

    Landsmann, Barbara; Pinter, Daniela; Pirker, Eva; Pichler, Gerald; Schippinger, Walter; Weiss, Elisabeth M; Mathie, Gabriel; Gattringer, Thomas; Fazekas, Franz; Enzinger, Christian

    2016-01-01

    Purpose Previous studies demonstrated changes in sensorimotor network activation over time after stroke that have been interpreted as partly compensatory. Locomotor and balance trainings may improve both mobility and cognition even in chronic stroke and thereby impact on cerebral activation patterns. We here aimed at testing these assumptions in an exploratory study to inform subsequent larger intervention studies. Patients and methods Eight patients (73.3±4.4 years) with a chronic lacunar stroke (mean interval 3.7 years after the acute event with a range from 2 to 4 years) and residual leg paresis leading to gait disturbance received a guided 5-week training focusing on mobility, endurance, and coordination. Before and afterward, they underwent clinical, neuropsychological, and gait assessments and brain MRI at 3 T including a functional ankle movement paradigm. Sixteen healthy controls (HCs; 68.8±5.4 years) followed the same protocol without intervention. Results After training, patients had improved in mobility, memory, and delayed recall of memory. While cerebral activations in HC remained completely unaltered, patients showed increased activations in the right precentral gyrus, the right and left superior frontal gyri, and the right frontal lobe, with bipedal ankle movements after training. Conclusion In this exploratory study of chronic stroke, we found not only significant effects of physical training on mobility but also distinct aspects of cognition already with a small number of highly selected patients. These improvements were paralleled by alterations in cerebral activity possibly reflecting neuronal plasticity. Larger studies including randomization are needed. PMID:26869779

  5. MRI and low back pain

    MedlinePlus

    Backache - MRI; Low back pain - MRI; Lumbar pain - MRI; Back strain - MRI; Lumbar radiculopathy - MRI; Herniated intervertebral disk - MRI; Prolapsed intervertebral disk - MRI; Slipped disk - MRI; Ruptured ...

  6. Progression of asymptomatic peripheral artery disease over 1 year.

    PubMed

    Mohler, Emile R; Bundens, Warner; Denenberg, Julie; Medenilla, Elizabeth; Hiatt, William R; Criqui, Michael H

    2012-02-01

    The pathophysiology and time course of an individual converting from asymptomatic peripheral artery disease (PAD) to symptomatic claudication is unclear. The objectives of this study were: (1) to characterize the extent of atherosclerotic disease in individuals with an abnormal ankle-brachial index (ABI), but without claudication; and over 1 year of follow-up to (2) evaluate the progression of PAD using ultrasound imaging, (3) determine changes in the ABI and leg pain symptoms, and (4) correlate PAD progression with changes in the ABI and leg symptoms. We hypothesized that PAD progression would be associated with the development of claudication and changes in the ABI, 6-minute walk distance (6-MWD), and walking quality of life. Individuals with a reduced ABI but without typical intermittent claudication noted on community screening were invited to undergo baseline and 1-year follow-up assessment, including duplex ultrasound. The initial and repeat evaluations included measurement of the ABI, lower extremity duplex arterial mapping, and assessment of leg pain and functional status. Of the 50 people studied, 44 (88%) had significant atherosclerotic lesions in the lower extremity arteries, affecting 80 legs. A total of 33 of 50 individuals (66%) returned for the 1-year follow-up visit. On ultrasound examination, two of 18 normal legs developed PAD, and in 48 legs with PAD at baseline, 17 legs (35%) developed new or progressive lesions. Thirteen legs developed new claudication. Overall, there was no significant worsening in the ABI, 6-MWD, or the Walking Impairment Questionnaire (WIQ). However, legs with new lesions or lesion progression were significantly more likely to develop claudication, and the 13 legs (seven subjects) developing claudication showed a significant decline in the 6-MWD. In conclusion, these data indicate that a significant number of people with asymptomatic PAD show progression over 1 year, that such individuals are more likely to develop

  7. MRI Scans

    MedlinePlus

    Magnetic resonance imaging (MRI) uses a large magnet and radio waves to look at organs and structures inside your body. Health care professionals use MRI scans to diagnose a variety of conditions, from torn ...

  8. Gauging MRI

    NASA Astrophysics Data System (ADS)

    Herron, Ison; Goodman, Jeremy

    2009-11-01

    Axisymmetric stability of viscous resistive magnetized Couette flow is re-examined, with emphasis on flows that would be hydrodynamically stable according to Rayleigh's criterion: opposing gradients of angular velocity and specific angular momentum. A uniform axial magnetic field permeates the fluid. In this regime, magnetorotational instability (MRI) may occur. It is proved that MRI is suppressed, in fact no instability at all occurs, with insulating boundary conditions, when the magnetic resistivity is sufficiently large. This shows conclusively that small magnetic dissipation is a feature of this instability for all magnetic Prandtl numbers. A criterion is provided for the onset of MRI.

  9. Musculoskeletal MRI.

    PubMed

    Sage, Jaime E; Gavin, Patrick

    2016-05-01

    MRI has the unique ability to detect abnormal fluid content, and is therefore unparalleled in its role of detection, diagnosis, prognosis, treatment planning and follow-up evaluation of musculoskeletal disease. MRI in companion animals should be considered in the following circumstances: a definitive diagnosis cannot be made on radiographs; a patient is nonresponsive to medical or surgical therapy; prognostic information is desired; assessing surgical margins and traumatic and/or infectious joint and bone disease; ruling out subtle developmental or early aggressive bone lesions. The MRI features of common disorders affecting the shoulder, elbow, stifle, carpal, and tarsal joints are included in this chapter.

  10. Portable MRI

    SciTech Connect

    Espy, Michelle A.

    2012-06-29

    This project proposes to: (1) provide the power of MRI to situations where it presently isn't available; (2) perform the engineering required to move from lab to a functional prototype; and (3) leverage significant existing infrastructure and capability in ultra-low field MRI. The reasons for doing this: (1) MRI is the most powerful tool for imaging soft-tissue (e.g. brain); (2) Billions don't have access due to cost or safety issues; (3) metal will heat/move in high magnetic fields; (4) Millions of cases of traumatic brain injury in US alone; (5) even more of non-traumatic brain injury; (6) (e.g. stroke, infection, chemical exposure); (7) Need for early diagnostic; (8) 'Signature' wound of recent conflicts; (9) 22% of injuries; (10) Implications for post-traumatic stress disorder; and (11) chronic traumatic encephalopathy.

  11. Battlefield MRI

    SciTech Connect

    Espy, Michelle

    2015-06-01

    Magnetic Resonance Imaging is the best method for non-invasive imaging of soft tissue anatomy, saving countless lives each year. It is regarded as the gold standard for diagnosis of mild to moderate traumatic brain injuries. Furthermore, conventional MRI relies on very high, fixed strength magnetic fields (> 1.5 T) with parts-per-million homogeneity, which requires very large and expensive magnets.

  12. Repeat-until-success quantum repeaters

    NASA Astrophysics Data System (ADS)

    Bruschi, David Edward; Barlow, Thomas M.; Razavi, Mohsen; Beige, Almut

    2014-09-01

    We propose a repeat-until-success protocol to improve the performance of probabilistic quantum repeaters. Conventionally, these rely on passive static linear-optics elements and photodetectors to perform Bell-state measurements (BSMs) with a maximum success rate of 50%. This is a strong impediment for entanglement swapping between distant quantum memories. Every time a BSM fails, entanglement needs to be redistributed between the corresponding memories in the repeater link. The key ingredients of our scheme are repeatable BSMs. Under ideal conditions, these turn probabilistic quantum repeaters into deterministic ones. Under realistic conditions, our protocol too might fail. However, using additional threshold detectors now allows us to improve the entanglement generation rate by almost orders of magnitude, at a nominal distance of 1000 km, compared to schemes that rely on conventional BSMs. This improvement is sufficient to make the performance of our scheme comparable to the expected performance of some deterministic quantum repeaters.

  13. Competitive advantage of PET/MRI.

    PubMed

    Jadvar, Hossein; Colletti, Patrick M

    2014-01-01

    Multimodality imaging has made great strides in the imaging evaluation of patients with a variety of diseases. Positron emission tomography/computed tomography (PET/CT) is now established as the imaging modality of choice in many clinical conditions, particularly in oncology. While the initial development of combined PET/magnetic resonance imaging (PET/MRI) was in the preclinical arena, hybrid PET/MR scanners are now available for clinical use. PET/MRI combines the unique features of MRI including excellent soft tissue contrast, diffusion-weighted imaging, dynamic contrast-enhanced imaging, fMRI and other specialized sequences as well as MR spectroscopy with the quantitative physiologic information that is provided by PET. Most evidence for the potential clinical utility of PET/MRI is based on studies performed with side-by-side comparison or software-fused MRI and PET images. Data on distinctive utility of hybrid PET/MRI are rapidly emerging. There are potential competitive advantages of PET/MRI over PET/CT. In general, PET/MRI may be preferred over PET/CT where the unique features of MRI provide more robust imaging evaluation in certain clinical settings. The exact role and potential utility of simultaneous data acquisition in specific research and clinical settings will need to be defined. It may be that simultaneous PET/MRI will be best suited for clinical situations that are disease-specific, organ-specific, related to diseases of the children or in those patients undergoing repeated imaging for whom cumulative radiation dose must be kept as low as reasonably achievable. PET/MRI also offers interesting opportunities for use of dual modality probes. Upon clear definition of clinical utility, other important and practical issues related to business operational model, clinical workflow and reimbursement will also be resolved.

  14. A Repeat Look at Repeating Patterns

    ERIC Educational Resources Information Center

    Markworth, Kimberly A.

    2016-01-01

    A "repeating pattern" is a cyclical repetition of an identifiable core. Children in the primary grades usually begin pattern work with fairly simple patterns, such as AB, ABC, or ABB patterns. The unique letters represent unique elements, whereas the sequence of letters represents the core that is repeated. Based on color, shape,…

  15. Choking first aid - infant under 1 year - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100221.htm Choking first aid - infant under 1 year - series—Part 1 To ... Loss of consciousness if blockage is not cleared FIRST AID 1. DO NOT perform these steps if the ...

  16. Pelvis MRI scan

    MedlinePlus

    MRI - pelvis; MRI - hips; Pelvic MRI with prostate probe; Magnetic resonance imaging - pelvis ... care provider if you are afraid of close spaces (have claustrophobia). You may be given a medicine ...

  17. Breast MRI scan

    MedlinePlus

    MRI - breast; Magnetic resonance imaging - breast; Breast cancer - MRI; Breast cancer screening - MRI ... the same breast or the other breast after breast cancer has been diagnosed Distinguish between scar tissue and ...

  18. Repeat hepatectomy for colorectal liver metastases.

    PubMed Central

    Adam, R; Bismuth, H; Castaing, D; Waechter, F; Navarro, F; Abascal, A; Majno, P; Engerran, L

    1997-01-01

    OBJECTIVE: The authors assess the long-term results of repeat hepatectomies for recurrent metastases of colorectal cancer and determine the factors that can predict survival. SUMMARY BACKGROUND DATA: Safer techniques of hepatic resection have allowed surgeons to consider repeat hepatectomy for colorectal metastases in an increasing number of patients. However, higher operative bleeding and increased morbidity have been reported after repeat hepatectomies, and the long-term benefit of these procedures needs to be evaluated. STUDY POPULATION: Sixty-four patients from a group of 243 patients resected for colorectal liver metastases were submitted to 83 repeat hepatectomies (64 second, 15 third, and 4 fourth hepatectomies). Combined extrahepatic surgery was performed in 21 (25%) of these 83 repeat hepatectomies. RESULTS: There was no intraoperative or postoperative mortality. Operative bleeding was not significantly increased in repeat hepatectomies as compared to first resections. Morbidity and duration of hospital stay were comparable to first hepatectomies. Overall and disease-free survival after a second hepatectomy were 60% and 42%, respectively, at 3 years and 41% and 26%, respectively, at 5 years. Factors of prognostic value on univariate analysis included the curative nature of first and second hepatectomies (p = 0.04 and p = 0.002, respectively), an interval between the two procedures of more than 1 year (p = 0.003), the number of recurrent tumors (p = 0.002), serum carcinoembryonic antigen levels (p = 0.03), and the presence of extrahepatic disease (p = 0.03). Only the curative nature of the second hepatectomy and an interval of more than 1 year between the two procedures were independently related to survival on multivariate analysis. CONCLUSIONS: Repeat hepatectomies can provide long-term survival rates similar to those of first hepatectomies, with no mortality and comparable morbidity. Combined extrahepatic surgery can be required to achieve tumor

  19. Anxiety Sensitivity and Panic Attacks: A 1-Year Longitudinal Study

    ERIC Educational Resources Information Center

    Li, Wen; Zinbarg, Richard E.

    2007-01-01

    The hypothesis that anxiety sensitivity (AS) is a risk factor for panic genesis has obtained compelling support, but the clinical/practical importance of AS in panic genesis has been questioned. In addition, the association between panic experience and AS increase has not been clearly demonstrated. Through this 1-year longitudinal study among…

  20. Pulmonary toxicity of cyclophosphamide: a 1-year study

    SciTech Connect

    Morse, C.C.; Sigler, C.; Lock, S.; Hakkinen, P.J.; Haschek, W.M.; Witschi, H.P.

    1985-01-01

    The development of cyclophosphamide-induced pulmonary lesions over a 1-year period was studied in mice. Male BALB/c mice received a single intraperitoneal injection of 100 mg/kg of cyclophosphamide. Within 3 weeks there were scattered foci of intraalveolar foamy macrophages. With time, these foci increased in size and, 1 year later, occupied large areas in all lung lobes. There was also diffuse interstitial fibrosis. Chemical determination done 3, 12, 24, and 52 weeks after cyclophosphamide showed that lungs of animals treated with cyclophosphamide had significantly more hydroxyproline per lung than controls. One year after cyclophosphamide pressure - volume curves measured in vivo were shifted down and to the right and total lung volumes were decreased. A single injection of cyclophosphamide produced an irreversible and progressive pulmonary lesion. 16 references, 5 figures, 3 tables.

  1. Secondary preventive medication persistence and adherence 1 year after stroke

    PubMed Central

    Olson, D.M.; Zhao, X.; Pan, W.; Zimmer, L.O.; Goldstein, L.B.; Alberts, M.J.; Fagan, S.C.; Fonarow, G.C.; Johnston, S.C.; Kidwell, C.; LaBresh, K.A.; Ovbiagele, B.; Schwamm, L.; Peterson, E.D.

    2011-01-01

    Objective: Data on long-term use of secondary prevention medications following stroke are limited. The Adherence eValuation After Ischemic stroke–Longitudinal (AVAIL) Registry assessed patient, provider, and system-level factors influencing continuation of prevention medications for 1 year following stroke hospitalization discharge. Methods: Patients with ischemic stroke or TIA discharged from 106 hospitals participating in the American Heart Association Get With The Guidelines–Stroke program were surveyed to determine their use of warfarin, antiplatelet, antihypertensive, lipid-lowering, and diabetes medications from discharge to 12 months. Reasons for stopping medications were ascertained. Persistence was defined as continuation of all secondary preventive medications prescribed at hospital discharge, and adherence as continuation of prescribed medications except those stopped according to health care provider instructions. Results: Of the 2,880 patients enrolled in AVAIL, 88.4% (2,457 patients) completed 1-year interviews. Of these, 65.9% were regimen persistent and 86.6% were regimen adherent. Independent predictors of 1-year medication persistence included fewer medications prescribed at discharge, having an adequate income, having an appointment with a primary care provider, and greater understanding of why medications were prescribed and their side effects. Independent predictors of adherence were similar to those for persistence. Conclusions: Although up to one-third of stroke patients discontinued one or more secondary prevention medications within 1 year of hospital discharge, self-discontinuation of these medications is uncommon. Several potentially modifiable patient, provider, and system-level factors associated with persistence and adherence may be targets for future interventions. PMID:21900638

  2. Stability of physical assessment of older drivers over 1 year.

    PubMed

    Smith, Andrew; Marshall, Shawn; Porter, Michelle; Ha, Linda; Bédard, Michel; Gélinas, Isabelle; Man-Son-Hing, Malcolm; Mazer, Barbara; Rapoport, Mark; Tuokko, Holly; Vrkljan, Brenda

    2013-12-01

    Older adults represent the fastest-growing population of drivers with a valid driver's licence. Also common in this age group are multiple chronic medical conditions that may have an effect on physical function and driving ability. Determining the reliability of physical measures used to assess older drivers' functional ability is important to identifying those who are safe to continue driving. Most previous reliability studies of clinical physical measures of health used test-retest intervals shorter than those between patient visits with a clinician. In the present study we examined a more clinically representative interval of 1 year to determine the stability of commonly used physical measures collected during the Candrive II prospective cohort study of older drivers. Reliability statistics indicate that the sequential finger-thumb opposition, rapid pace walk and the Pelli-Robson contrast sensitivity tests have adequate stability over 1 year. Poor stability was observed for the one-legged stance and Snellen visual acuity test. Several assessments with nominal data (Marottoli method [functional neck range of motion], whispered voice test, range of motion and strength testing) lacked sufficient variability to conduct reliability analyses; however, a lack of variability between test days suggests consistency over a 1-year time frame. Our results provide evidence that specific physical measures are stable in monitoring functional ability over the course of a year.

  3. MRI appearances of borderline ovarian tumours.

    PubMed

    Bent, C L; Sahdev, A; Rockall, A G; Singh, N; Sohaib, S A; Reznek, R H

    2009-04-01

    This review was performed to describe the range of magnetic resonance imaging (MRI) appearances of borderline ovarian tumours. The MRI findings in 26 patients with 31 borderline ovarian tumours (mean age: 40.1 years, range: 14-85 years) were retrospectively reviewed. For each tumour, site, size, MRI characteristics, and enhancement following gadolinium administration were recorded. There were 20 serous and 11 mucinous borderline ovarian subtypes. Nine of 26 patients demonstrated bilateral disease on MRI; synchronous contralateral ovarian disease included three benign, five serous borderline, and one serous invasive tumour. A history of a metachronous mucinous borderline tumour was identified in one patient. MRI appearances were classified into four morphological categories: group 1 (6/31, 19%), unilocular cysts; group 2 (6/31, 19%), minimally septate cysts with papillary projections; group 3 (14/31, 45%), markedly septate lesions with plaque-like excrescences; and group 4 (5/31, 16%), predominantly solid with exophytic papillary projections, all of serous subtype. There was a significant difference in mean volume between serous (841.5 cm(3)) and mucinous (6358.2 cm(3)) subtypes (p=0.009). All tumours demonstrated at least one MRI feature suggestive of malignancy. The present review demonstrates the variable MRI appearances of borderline ovarian tumours along with imaging features suggestive of tumour subtype. In patients in whom the clinical features are suggestive of a borderline ovarian tumour (young age and normal or minimally elevated CA125), the ability to predict a borderline disease using morphological features observed on MRI would be extremely helpful in surgical planning, with the potential to offer fertility or ovary-preserving surgery. Future studies are required to further this aim.

  4. Revisiting the TALE repeat.

    PubMed

    Deng, Dong; Yan, Chuangye; Wu, Jianping; Pan, Xiaojing; Yan, Nieng

    2014-04-01

    Transcription activator-like (TAL) effectors specifically bind to double stranded (ds) DNA through a central domain of tandem repeats. Each TAL effector (TALE) repeat comprises 33-35 amino acids and recognizes one specific DNA base through a highly variable residue at a fixed position in the repeat. Structural studies have revealed the molecular basis of DNA recognition by TALE repeats. Examination of the overall structure reveals that the basic building block of TALE protein, namely a helical hairpin, is one-helix shifted from the previously defined TALE motif. Here we wish to suggest a structure-based re-demarcation of the TALE repeat which starts with the residues that bind to the DNA backbone phosphate and concludes with the base-recognition hyper-variable residue. This new numbering system is consistent with the α-solenoid superfamily to which TALE belongs, and reflects the structural integrity of TAL effectors. In addition, it confers integral number of TALE repeats that matches the number of bound DNA bases. We then present fifteen crystal structures of engineered dHax3 variants in complex with target DNA molecules, which elucidate the structural basis for the recognition of bases adenine (A) and guanine (G) by reported or uncharacterized TALE codes. Finally, we analyzed the sequence-structure correlation of the amino acid residues within a TALE repeat. The structural analyses reported here may advance the mechanistic understanding of TALE proteins and facilitate the design of TALEN with improved affinity and specificity.

  5. Getting an MRI

    MedlinePlus

    ... Help White House Lunch Recipes Getting an MRI (Video) KidsHealth > For Kids > Getting an MRI (Video) A A A en español Obtención de una resonancia magnética, RM (video) An MRI (magnetic resonance imaging) scan creates detailed ...

  6. Night waking in 1-year-old children in England.

    PubMed

    Scott, G; Richards, M P

    1990-01-01

    A national sample of 1500 mothers of 1-year-old children received a postal questionnaire concerned with the sleeping patterns of their children. The response rate was 69%. Seventeen per cent of mothers reported that their 1-year-old presented a moderate or severe sleep problem and 26% said their child woke at night on at least five nights a week. While these two measures correlated, 10% of those who reported their infant woke on at least five nights a week did not consider this to be a problem. Neither sex of infant, social class, method of infant feeding or numbers of house moves were associated with sleep problems. The pattern of results strongly suggest an association between night waking and other sleeping difficulties and stress for mothers. This was indicated by the association we found with complaints about housing, overcrowding, more negative attitudes toward motherhood, lower assessments of maternal well-being, lack of practical support from partners, the use of more negative adjectives to describe their baby and more frequent feelings of being dominated by their baby. While these associations may be explained by the stresses of living with a night-waking baby, it is also likely that a mother who is feeling somewhat depressed and negative toward her baby is more likely to see night waking as significant and as a problem. There were class differences in how parents coped with a shortage of space. Middle-class parents were more likely to put a baby in with a sibling while working class parents more often had the baby in their own room. Middle-class parents were more likely to leave a night-waking baby to cry. PMID:2225345

  7. Otitis media with effusion in children younger than 1 year

    PubMed Central

    Di Francesco, Renata Cantisani; Barros, Vivian Boschesi; Ramos, Rafael

    2016-01-01

    Abstract Objective: To determine the prevalence of otitis media with effusion in children younger than 1 year and its association with the season of the year, artificial feeding, environmental and perinatal factors. Methods: Retrospective study of 184 randomly included medical records from a total of 982 healthy infants evaluated for hearing screening tests. Diagnosis of otitis media with effusion was based on otoscopy (amber-gold color, fluid level, handle of malleus position), type B tympanometric curves and absence of otoacoustic emissions. Incomplete medical records or those describing acute otitis media, upper respiratory tract infections on the assessment day or in the last 3 months, neuropathies and craniofacial anomalies were excluded. Data such as gestational age, birth weight, Apgar score, type of feeding and day care attendance were compared between children with and without otitis media with effusion through likelihood tests and multivariate analysis. Results: 25.3% of 184 infants had otitis media with bilateral effusion; 9.2% had unilateral. In infants with otitis media, the following were observed: chronological age of 9.6±1.7 months; gestational age >38 weeks in 43.4% and birth weight >2500g in 48.4%. Otitis media with effusion was associated with winter/fall, artificial feeding, Apgar score <7 and day care attendance. The multivariate analysis showed that artificial feeding is the factor most often associated to otitis media with effusion. Conclusions: Otitis media with effusion was found in about one third of children younger than 1 year and was mainly associated with artificial feeding. PMID:26559603

  8. A database of age-appropriate average MRI templates.

    PubMed

    Richards, John E; Sanchez, Carmen; Phillips-Meek, Michelle; Xie, Wanze

    2016-01-01

    This article summarizes a life-span neurodevelopmental MRI database. The study of neurostructural development or neurofunctional development has been hampered by the lack of age-appropriate MRI reference volumes. This causes misspecification of segmented data, irregular registrations, and the absence of appropriate stereotaxic volumes. We have created the "Neurodevelopmental MRI Database" that provides age-specific reference data from 2 weeks through 89 years of age. The data are presented in fine-grained ages (e.g., 3 months intervals through 1 year; 6 months intervals through 19.5 years; 5 year intervals from 20 through 89 years). The base component of the database at each age is an age-specific average MRI template. The average MRI templates are accompanied by segmented partial volume estimates for segmenting priors, and a common stereotaxic atlas for infant, pediatric, and adult participants. The database is available online (http://jerlab.psych.sc.edu/NeurodevelopmentalMRIDatabase/).

  9. Uterine cirsoid aneurysm: MRI and MRA

    SciTech Connect

    Joja, Ikuo; Asakawa, Mari; Motoyama, Kazumi

    1996-03-01

    Uterine cirsoid aneurysm is uncommon. It is important to make a diagnosis of this disease preoperatively, because repeated curettages may induce life-threatening massive genital bleeding. We present a case of a 51-year-old woman with uterine cirsoid aneurysm in whom MRI and MRA were very useful for the preoperative diagnosis. The radiologic appearances on ultrasonography, CT, conventional SE MRI, MRA, dynamic MRI, and pelvic angiography are presented. Conventional SE T1-weighted and T2-weighted images demonstrated multiple flow voids in the uterus and bilateral adnexal regions. MRA demonstrated a cluster of distinct, tortuous, and coiled vascular channels in the pelvis. MRA could obtain images almost equal to angiography and was considered to be an excellent noninvasive imaging technique for the diagnosis of uterine cirsoid aneurysm. 28 refs., 7 figs

  10. Health Care Costs 1 Year After Pediatric Traumatic Brain Injury

    PubMed Central

    Rivara, Frederick P.; Vavilala, Monica S.

    2015-01-01

    Objectives. This study sought to estimate total health care costs for mild, moderate, and severe pediatric traumatic brain injury (TBI) and to compare individual- and population-level costs across levels of TBI severity. Methods. Using 2007 to 2010 MarketScan Commercial Claims and Encounters data, we estimated total quarterly health care costs 1 year after TBI among enrollees (aged < 18 years). We compared costs across levels of TBI severity using generalized linear models. Results. Mild TBI accounted for 96.6% of the 319 103 enrollees with TBI; moderate and severe TBI accounted for 1.7% and 1.6%, respectively. Adjusted individual health care costs for moderate and severe TBI were significantly higher than mild TBI in the year after injury (P < .01). At the population level, moderate and severe TBI costs were 88% and 75% less than mild TBI, respectively. Conclusions. Individually, moderate and severe TBI initially generated costs that were markedly higher than those of mild TBI. At the population level, costs following mild TBI far exceeded those of more severe cases, a result of the extremely high population burden of mild TBI. PMID:26270293

  11. Smoking Cessation 1 Year or More: Experiences of Successful Quitters.

    PubMed

    DiPiazza, Jennifer T; Naegle, Madeline

    2016-01-01

    There is a paucity of research focused on the experience of maintaining cessation for a year or longer, and recidivism rates for smoking cessation are estimated at 50% to 97%. As cigarette smoking is one of the leading causes of death worldwide, there is a critical need for more knowledge about maintaining smoking cessation. Therefore, this study was undertaken to explore the lived experience of maintaining cigarette smoking cessation for a year or more. Using Streubert's nurse-developed descriptive phenomenological method, seven adults who sustained cessation for 1.5 to 18 years, after repeated relapses, were interviewed about their experience of sustaining cessation. Data collection included interviews, field notes, and a reflexive journal. Phenomenological analysis involved dwelling intensely with the data, extracting parts of the transcript, and identifying codes and themes, defined by Streubert as essences, common to all participants' descriptions of the experience of sustained cessation. Through this inductive process, the investigator ascertained relationships among the essences, forming the basis for a formalized, exhaustive description of the experience. Six essences captured participants' experiences of maintaining cigarette smoking cessation: (a) breaking free, (b) developing an olfactory aversion, (c) reframing, (d) learning through relapse, (e) reclaiming acceptance, and (f) self-transformation. The findings suggest that maintaining cessation for a year or more is shaped by biological, psychological, and social conditions, as reflected in the essences. The essences coalesced to a tipping point of motivation and conditions leading to sustained behavior change, allowing participants to maintain cessation.

  12. Smoking Cessation 1 Year or More: Experiences of Successful Quitters.

    PubMed

    DiPiazza, Jennifer T; Naegle, Madeline

    2016-01-01

    There is a paucity of research focused on the experience of maintaining cessation for a year or longer, and recidivism rates for smoking cessation are estimated at 50% to 97%. As cigarette smoking is one of the leading causes of death worldwide, there is a critical need for more knowledge about maintaining smoking cessation. Therefore, this study was undertaken to explore the lived experience of maintaining cigarette smoking cessation for a year or more. Using Streubert's nurse-developed descriptive phenomenological method, seven adults who sustained cessation for 1.5 to 18 years, after repeated relapses, were interviewed about their experience of sustaining cessation. Data collection included interviews, field notes, and a reflexive journal. Phenomenological analysis involved dwelling intensely with the data, extracting parts of the transcript, and identifying codes and themes, defined by Streubert as essences, common to all participants' descriptions of the experience of sustained cessation. Through this inductive process, the investigator ascertained relationships among the essences, forming the basis for a formalized, exhaustive description of the experience. Six essences captured participants' experiences of maintaining cigarette smoking cessation: (a) breaking free, (b) developing an olfactory aversion, (c) reframing, (d) learning through relapse, (e) reclaiming acceptance, and (f) self-transformation. The findings suggest that maintaining cessation for a year or more is shaped by biological, psychological, and social conditions, as reflected in the essences. The essences coalesced to a tipping point of motivation and conditions leading to sustained behavior change, allowing participants to maintain cessation. PMID:27580193

  13. Honesty through repeated interactions.

    PubMed

    Rich, Patricia; Zollman, Kevin J S

    2016-04-21

    In the study of signaling, it is well known that the cost of deception is an essential element for stable honest signaling in nature. In this paper, we show how costs for deception can arise endogenously from repeated interactions between individuals. Utilizing the Sir Philip Sidney game as an illustrative case, we show that repeated interactions can sustain honesty with no observable signal costs, even when deception cannot be directly observed. We provide a number of potential experimental tests for this theory which distinguish it from the available alternatives.

  14. Varicella paediatric hospitalisations in Belgium: a 1-year national survey

    PubMed Central

    Blumental, Sophie; Sabbe, Martine; Lepage, Philippe

    2016-01-01

    Background Varicella universal vaccination (UV) has been implemented in many countries for several years. Nevertheless, varicella UV remains debated in Europe and few data are available on the real burden of infection. We assessed the burden of varicella in Belgium through analysis of hospitalised cases during a 1-year period. Methods Data on children admitted to hospital with varicella were collected through a national network from November 2011 to October 2012. Inclusion criteria were either acute varicella or related complications up to 3 weeks after the rash. Results Participation of 101 hospitals was obtained, covering 97.7% of the total paediatric beds in Belgium. 552 children were included with a median age of 2.1 years. Incidence of paediatric varicella hospitalisations reached 29.5/105 person-years, with the highest impact among those 0–4 years old (global incidence and odds of hospitalisation: 79/105 person-years and 1.6/100 varicella cases, respectively). Only 14% (79/552) of the cohort had an underlying chronic condition. 65% (357/552) of children had ≥1 complication justifying their admission, 49% were bacterial superinfections and 10% neurological disorders. Only a quarter of children (141/552) received acyclovir. Incidence of complicated hospitalised cases was 19/105 person-years. Paediatric intensive care unit admission and surgery were required in 4% and 3% of hospitalised cases, respectively. Mortality among Belgian paediatric population was 0.5/106 and fatality ratio 0.2% among our cohort. Conclusions Varicella demonstrated a substantial burden of disease in Belgian children, especially among the youngest. Our thorough nationwide study, run in a country without varicella UV, offers data to support varicella UV in Belgium. PMID:26130380

  15. MRI brain imaging.

    PubMed

    Skinner, Sarah

    2013-11-01

    General practitioners (GPs) are expected to be allowed to request MRI scans for adults for selected clinically appropriate indications from November 2013 as part of the expansion of Medicare-funded MRI services announced by the Federal Government in 2011. This article aims to give a brief overview of MRI brain imaging relevant to GPs, which will facilitate explanation of scan findings and management planning with their patients. Basic imaging techniques, common findings and terminology are presented using some illustrative case examples.

  16. Slit Wheel Repeatability

    NASA Astrophysics Data System (ADS)

    DiFelice, Audrey

    2012-10-01

    Test the repeatibility of the slit wheel by taking a sequence of comparison lamp spectra with grating G230MB {2697} and the three smallest long slits {52X0.2, 52X0.1, and 52X0.05}. This is a clone of Cycle 19 Program 12771.

  17. Slit Wheel Repeatability

    NASA Astrophysics Data System (ADS)

    Long, Chris

    2011-10-01

    Test the repeatibility of the slit wheel by taking a sequence of comparison lamp spectra with grating G230MB {2697} and the three smallest long slits {52X0.2, 52X0.1, and 52X0.05}. This is a clone of Cycle 18 Program 12410.

  18. Slit Wheel Repeatability

    NASA Astrophysics Data System (ADS)

    DiFelice, Audrey

    2013-10-01

    Test the repeatibility of the slit wheel by taking a sequence of comparison lamp spectra with grating G230MB {2697} and the three smallest long slits {52X0.2, 52X0.1, and 52X0.05}. This is a clone of Cycle 20 Program 13140.

  19. Slit Wheel Repeatability

    NASA Astrophysics Data System (ADS)

    Zheng, Wei

    2010-09-01

    Test the repeatibility of the slit wheel by taking a sequence of comparison lamp spectra with grating G230MB {2697} and the three smallest long slits {52X0.2, 52X0.1, and 52X0.05}. This is a clone of Cycle 17 Program 11851.

  20. Repeated Causal Decision Making

    ERIC Educational Resources Information Center

    Hagmayer, York; Meder, Bjorn

    2013-01-01

    Many of our decisions refer to actions that have a causal impact on the external environment. Such actions may not only allow for the mere learning of expected values or utilities but also for acquiring knowledge about the causal structure of our world. We used a repeated decision-making paradigm to examine what kind of knowledge people acquire in…

  1. All-optical repeater.

    PubMed

    Silberberg, Y

    1986-06-01

    An all-optical device containing saturable gain, saturable loss, and unsaturable loss is shown to transform weak, distorted optical pulses into uniform standard-shape pulses. The proposed device performs thresholding, amplification, and pulse shaping as required from an optical repeater. It is shown that such a device could be realized by existing semiconductor technology.

  2. Bidirectional Manchester repeater

    NASA Technical Reports Server (NTRS)

    Ferguson, J.

    1980-01-01

    Bidirectional Manchester repeater is inserted at periodic intervals along single bidirectional twisted pair transmission line to detect, amplify, and transmit bidirectional Manchester 11 code signals. Requiring only 18 TTL 7400 series IC's, some line receivers and drivers, and handful of passive components, circuit is simple and relatively inexpensive to build.

  3. Case report: repeated neonaticides in Hokkaido.

    PubMed

    Funayama, M; Ikeda, T; Tabata, N; Azumi, J; Morita, M

    1994-02-01

    Five cases of repeated neonaticides were reported in Hokkaido, the northernmost island of Japan, during the 10 years from 1983 to 1992. Four or more neonates were involved in each case by each mother. All the suspected mothers were not mentally ill. Two of them were single and the rest were married. Each husband was not aware of the pregnancy of his wife, because he was away from home very often. The main motive of murder seemed to be economic and/or to save appearances. Sentences were 1 year penal servitude with a stay of 3 years for one case, but 30-42 months in prison for the other four cases. We rarely find reports of repeated infanticides committed by the same mother in European countries and the United States.

  4. Tissue-Point Motion Tracking in the Tongue from Cine-MRI and Tagged-MRI

    PubMed Central

    Woo, Jonghye; Stone, Maureen; Suo, Yuanming; Murano, Emi Z.; Prince, Jerry L.

    2015-01-01

    Purpose Accurate tissue motion tracking within the tongue can help to diagnose and treat vocal tract related disorders, evaluate speech quality before and after surgery, and conduct various scientific studies. We have compared tissue tracking results from four widely used deformable registration (DR) methods applied to Cine-MRI with harmonic phase (HARP)-based tracking applied to tagged-MRI. Method Ten subjects repeated the words “a geese” multiple times while sagittal images of the head were collected at 26 Hz, first in a tagged-MRI data set, and then in a Cine-MRI data set. HARP tracked the motion of eight specified tissue points in the tagged data set. Four DR methods including diffeomorphic demons and free-form deformations based on cubic B-spline with three different similarity measures were used to track the same eight points in the Cine-MRI data set. Individual points were tracked and length changes of several muscles were calculated using the DR and HARP based tracking methods. Results Results showed that the DR tracking errors were non-systematic and varied in direction, amount, and timing across speakers and within speakers. Comparison of HARP and DR tracking with manual tracking showed better tracking results for HARP except at the tongue surface, where mistracking caused greater errors in HARP than DR. Conclusions Tissue point tracking using DR tracking methods contain non-systematic tracking errors within and across subjects, making it less successful than tagged-MRI tracking within the tongue. However, HARP sometimes mistracks points at the tongue surface of tagged MRI due to its limited bandpass filter and tag pattern fading, so that DR has better success measuring surface tissue points on Cine-MRI than HARP does. Therefore a hybrid method is being explored. PMID:24686470

  5. CEST MRI reporter genes.

    PubMed

    Liu, Guanshu; Bulte, Jeff W M; Gilad, Assaf A

    2011-01-01

    In recent years, several reporter genes have been developed that can serve as a beacon for non-invasive magnetic resonance imaging (MRI). Here, we provide a brief summary of recent advances in MRI reporter gene technology, as well as detailed "hands-on" protocols for cloning, expression, and imaging of reporter genes based on chemical exchange saturation transfer (CEST).

  6. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-01-01

    Duct leakage often needs to be measured to demonstrate compliance with requirements or to determine energy or Indoor Air Quality (IAQ) impacts. Testing is often done using standards such as ASTM E1554 (ASTM 2013) or California Title 24 (California Energy Commission 2013 & 2013b), but there are several choices of methods available within the accepted standards. Determining which method to use or not use requires an evaluation of those methods in the context of the particular needs. Three factors that are important considerations are the cost of the measurement, the accuracy of the measurement and the repeatability of the measurement. The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards.

  7. Accumulate repeat accumulate codes

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative channel coding scheme called 'Accumulate Repeat Accumulate codes' (ARA). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes, thus belief propagation can be used for iterative decoding of ARA codes on a graph. The structure of encoder for this class can be viewed as precoded Repeat Accumulate (RA) code or as precoded Irregular Repeat Accumulate (IRA) code, where simply an accumulator is chosen as a precoder. Thus ARA codes have simple, and very fast encoder structure when they representing LDPC codes. Based on density evolution for LDPC codes through some examples for ARA codes, we show that for maximum variable node degree 5 a minimum bit SNR as low as 0.08 dB from channel capacity for rate 1/2 can be achieved as the block size goes to infinity. Thus based on fixed low maximum variable node degree, its threshold outperforms not only the RA and IRA codes but also the best known LDPC codes with the dame maximum node degree. Furthermore by puncturing the accumulators any desired high rate codes close to code rate 1 can be obtained with thresholds that stay close to the channel capacity thresholds uniformly. Iterative decoding simulation results are provided. The ARA codes also have projected graph or protograph representation that allows for high speed decoder implementation.

  8. Comprehensive MRI simulation methodology using a dedicated MRI scanner in radiation oncology for external beam radiation treatment planning

    SciTech Connect

    Paulson, Eric S.; Erickson, Beth; Schultz, Chris; Allen Li, X.

    2015-01-15

    Purpose: The use of magnetic resonance imaging (MRI) in radiation oncology is expanding rapidly, and more clinics are integrating MRI into their radiation therapy workflows. However, radiation therapy presents a new set of challenges and places additional constraints on MRI compared to diagnostic radiology that, if not properly addressed, can undermine the advantages MRI offers for radiation treatment planning (RTP). The authors introduce here strategies to manage several challenges of using MRI for virtual simulation in external beam RTP. Methods: A total of 810 clinical MRI simulation exams were performed using a dedicated MRI scanner for external beam RTP of brain, breast, cervix, head and neck, liver, pancreas, prostate, and sarcoma cancers. Patients were imaged in treatment position using MRI-optimal immobilization devices. Radiofrequency (RF) coil configurations and scan protocols were optimized based on RTP constraints. Off-resonance and gradient nonlinearity-induced geometric distortions were minimized or corrected prior to using images for RTP. A multidisciplinary MRI simulation guide, along with window width and level presets, was created to standardize use of MR images during RTP. A quality assurance program was implemented to maintain accuracy and repeatability of MRI simulation exams. Results: The combination of a large bore scanner, high field strength, and circumferentially wrapped, flexible phased array RF receive coils permitted acquisition of thin slice images with high contrast-to-noise ratio (CNR) and image intensity uniformity, while simultaneously accommodating patient setup and immobilization devices. Postprocessing corrections and alternative acquisition methods were required to reduce or correct off-resonance and gradient nonlinearity induced geometric distortions. Conclusions: The methodology described herein contains practical strategies the authors have implemented through lessons learned performing clinical MRI simulation exams. In

  9. The Effect of fMRI (Noise) on Cognitive Control

    ERIC Educational Resources Information Center

    Hommel, Bernhard; Fischer, Rico; Colzato, Lorenza S.; van den Wildenberg, Wery P. M.; Cellini, Cristiano

    2012-01-01

    Stressful situations, the aversiveness of events, or increases in task difficulty (e.g., conflict) have repeatedly been shown to be capable of triggering attentional control adjustments. In the present study we tested whether the particularity of an fMRI testing environment (i.e., EPI noise) might result in such increases of the cognitive control…

  10. Variability in Muscle Damage after Eccentric Exercise and the Repeated Bout Effect

    ERIC Educational Resources Information Center

    Chen, Trevor C.

    2006-01-01

    The first purpose of this study was to determine a possible explanation for the variability in the response to eccentric exercise by having participants repeat the same exercise 1 year apart. The second purpose was to examine whether initial injury in response to eccentric exercise was associated with the extent of the repeated bout effect (RBE).…

  11. Duct Leakage Repeatability Testing

    SciTech Connect

    Walker, Iain; Sherman, Max

    2014-08-01

    The purpose of this report is to evaluate the repeatability of the three most significant measurement techniques for duct leakage using data from the literature and recently obtained field data. We will also briefly discuss the first two factors. The main question to be answered by this study is to determine if differences in the repeatability of these tests methods is sufficient to indicate that any of these methods is so poor that it should be excluded from consideration as an allowed procedure in codes and standards. The three duct leak measurement methods assessed in this report are the two duct pressurization methods that are commonly used by many practitioners and the DeltaQ technique. These are methods B, C and A, respectively of the ASTM E1554 standard. Although it would be useful to evaluate other duct leak test methods, this study focused on those test methods that are commonly used and are required in various test standards, such as BPI (2010), RESNET (2014), ASHRAE 62.2 (2013), California Title 24 (CEC 2012), DOE Weatherization and many other energy efficiency programs.

  12. Repeated measures with zeros.

    PubMed

    Berk, K N; Lachenbruch, P A

    2002-08-01

    Consider repeated measures data with many zeros. For the case with one grouping factor and one repeated measure, we examine several models, assuming that the nonzero data are roughly lognormal. One of the simplest approaches is to model the zeros as left-censored observations from the lognormal distribution. A random effect is assumed for subjects. The censored model makes a strong assumption about the relationship between the zeros and the nonzero values. To check on this, you can instead assume that some of the zeros are 'true' zeros and model them as Bernoulli. Then the other values are modeled with a censored lognormal. A logistic model is used for the Bernoulli p, the probability of a true nonzero. The fit of the pure left-censored lognormal can be assessed by testing the hypothesis that p is 1, as described by Moulton and Halsey. The model can also be simplified by omitting the censoring, leaving a logistic model for the zeros and a lognormal model for the nonzero values. This is approximately equivalent to modeling the zero and nonzero values separately, a two-part model. In contrast to the censored model, this model assumes only a slight relationship (a covariance component) between the occurrence of zeros and the size of the nonzero values. The models are compared in terms of an example with data from children's private speech. PMID:12197298

  13. Neonatal cranial ultrasound versus MRI and neurodevelopmental outcome at school age in children born preterm

    PubMed Central

    Rademaker, K; Uiterwaal, C; Beek, F; van Haastert, I C; Lieftink, A; Groenendaal, F; Grobbee, D; de Vries, L S

    2005-01-01

    Aim: To examine the correlation between neonatal cranial ultrasound and school age magnetic resonance imaging (MRI) and neurodevelopmental outcome. Methods: In a prospective 2 year cohort study, 221 children (gestational age ⩽32 weeks and/or birth weight ⩽1500 g) participated at a median age of 8.1 years (inclusion percentage 78%). Conventional MRI, IQ (subtests of the WISC), and motor performance (Movement Assessment Battery for Children) at school age were primary outcome measurements. Results: Overall, there was poor correspondence between ultrasound group classifications and MRI group classifications, except for the severe group (over 70% agreement). There was only a 1% chance of the children with a normal cranial ultrasound having a major lesion on MRI. Mean IQ (standard deviation) was significantly lower in children with major ultrasound or MRI lesions, but was also lower in children with minor lesions on MRI compared to children with a normal MRI (91±16, 100±13, 104±13 for major lesions, minor lesions, and normal MRI, respectively). Median total impairment score (TIS) was significantly higher in children with major lesions on ultrasound or MRI as well as in children with minor lesions on MRI (TIS 4.0 and 6.25 for normal and minor lesions on MRI, respectively; p<0.0001). Conclusions: A normal neonatal cranial ultrasound excluded a severe lesion on MRI in 99% of cases. MRI correlated more strongly with mean IQ and median TIS than ultrasound. Subtle white matter lesions are better detected with MRI which could explain the stronger correlation of MRI with IQ and motor performance. PMID:15956095

  14. Repeat Customer Success in Extension

    ERIC Educational Resources Information Center

    Bess, Melissa M.; Traub, Sarah M.

    2013-01-01

    Four multi-session research-based programs were offered by two Extension specialist in one rural Missouri county. Eleven participants who came to multiple Extension programs could be called "repeat customers." Based on the total number of participants for all four programs, 25% could be deemed as repeat customers. Repeat customers had…

  15. Leg MRI scan

    MedlinePlus

    ... resonance imaging) scan of the leg uses strong magnets to create pictures of the leg. This may ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed into the room ...

  16. Shoulder MRI scan

    MedlinePlus

    ... an imaging test that uses energy from powerful magnets and to create pictures of the shoulder area. ... in your eyes) Because the MRI contains strong magnets, metal objects are not allowed in the room ...

  17. MRI (Magnetic Resonance Imaging)

    MedlinePlus

    ... some MRI exams, intravenous (IV) drugs, such as gadolinium-based contrast agents (GBCAs) are used to change the contrast of the MR image. Gadolinium-based contrast agents are rare earth metals that ...

  18. MRI of the Breast

    MedlinePlus

    ... as a supplemental tool to breast screening with mammography or ultrasound. It may be used to screen ... following diagnosis, or further evaluate abnormalities seen on mammography. Breast MRI does not use ionizing radiation, and ...

  19. Abdominal MRI scan

    MedlinePlus

    Nuclear magnetic resonance - abdomen; NMR - abdomen; Magnetic resonance imaging - abdomen; MRI of the abdomen ... used to look at: Blood flow in the abdomen Blood vessels in the abdomen The cause of ...

  20. MRI of the Chest

    MedlinePlus

    ... magnetic field of the MRI unit, metal and electronic items are not allowed in the exam room. ... tell the technologist if you have medical or electronic devices in your body. These objects may interfere ...

  1. Lumbar MRI scan

    MedlinePlus

    ... may need a lumbar MRI if you have: Low back pain that does not get better after treatment Leg ... spine Injury or trauma to the lower spine Low back pain and a history or signs of cancer Multiple ...

  2. Knee MRI scan

    MedlinePlus

    ... have been no reported side effects from the magnetic fields and radio waves. The most common type of ... health care provider before the test. The strong magnetic fields created during an MRI can cause heart pacemakers ...

  3. Cervical MRI scan

    MedlinePlus

    ... have been no reported side effects from the magnetic fields and radio waves. The most common type of ... tell your provider before the test. The strong magnetic fields created during an MRI can cause heart pacemakers ...

  4. Arm MRI scan

    MedlinePlus

    ... have been no reported side effects from the magnetic fields and radio waves. The most common type of ... tell your provider before the test The strong magnetic fields created during an MRI can cause heart pacemakers ...

  5. Molecular fMRI

    PubMed Central

    Bartelle, Benjamin B.; Barandov, Ali

    2016-01-01

    Comprehensive analysis of brain function depends on understanding the dynamics of diverse neural signaling processes over large tissue volumes in intact animals and humans. Most existing approaches to measuring brain signaling suffer from limited tissue penetration, poor resolution, or lack of specificity for well-defined neural events. Here we discuss a new brain activity mapping method that overcomes some of these problems by combining MRI with contrast agents sensitive to neural signaling. The goal of this “molecular fMRI” approach is to permit noninvasive whole-brain neuroimaging with specificity and resolution approaching current optical neuroimaging methods. In this article, we describe the context and need for molecular fMRI as well as the state of the technology today. We explain how major types of MRI probes work and how they can be sensitized to neurobiological processes, such as neurotransmitter release, calcium signaling, and gene expression changes. We comment both on past work in the field and on challenges and promising avenues for future development. SIGNIFICANCE STATEMENT Brain researchers currently have a choice between measuring neural activity using cellular-level recording techniques, such as electrophysiology and optical imaging, or whole-brain imaging methods, such as fMRI. Cellular level methods are precise but only address a small portion of mammalian brains; on the other hand, whole-brain neuroimaging techniques provide very little specificity for neural pathways or signaling components of interest. The molecular fMRI techniques we discuss have particular potential to combine the specificity of cellular-level measurements with the noninvasive whole-brain coverage of fMRI. On the other hand, molecular fMRI is only just getting off the ground. This article aims to offer a snapshot of the status and future prospects for development of molecular fMRI techniques. PMID:27076413

  6. Optogenetic Functional MRI

    PubMed Central

    Lin, Peter; Fang, Zhongnan; Liu, Jia; Lee, Jin Hyung

    2016-01-01

    The investigation of the functional connectivity of precise neural circuits across the entire intact brain can be achieved through optogenetic functional magnetic resonance imaging (ofMRI), which is a novel technique that combines the relatively high spatial resolution of high-field fMRI with the precision of optogenetic stimulation. Fiber optics that enable delivery of specific wavelengths of light deep into the brain in vivo are implanted into regions of interest in order to specifically stimulate targeted cell types that have been genetically induced to express light-sensitive trans-membrane conductance channels, called opsins. fMRI is used to provide a non-invasive method of determining the brain's global dynamic response to optogenetic stimulation of specific neural circuits through measurement of the blood-oxygen-level-dependent (BOLD) signal, which provides an indirect measurement of neuronal activity. This protocol describes the construction of fiber optic implants, the implantation surgeries, the imaging with photostimulation and the data analysis required to successfully perform ofMRI. In summary, the precise stimulation and whole-brain monitoring ability of ofMRI are crucial factors in making ofMRI a powerful tool for the study of the connectomics of the brain in both healthy and diseased states. PMID:27167840

  7. RepeatsDB: a database of tandem repeat protein structures

    PubMed Central

    Di Domenico, Tomás; Potenza, Emilio; Walsh, Ian; Gonzalo Parra, R.; Giollo, Manuel; Minervini, Giovanni; Piovesan, Damiano; Ihsan, Awais; Ferrari, Carlo; Kajava, Andrey V.; Tosatto, Silvio C.E.

    2014-01-01

    RepeatsDB (http://repeatsdb.bio.unipd.it/) is a database of annotated tandem repeat protein structures. Tandem repeats pose a difficult problem for the analysis of protein structures, as the underlying sequence can be highly degenerate. Several repeat types haven been studied over the years, but their annotation was done in a case-by-case basis, thus making large-scale analysis difficult. We developed RepeatsDB to fill this gap. Using state-of-the-art repeat detection methods and manual curation, we systematically annotated the Protein Data Bank, predicting 10 745 repeat structures. In all, 2797 structures were classified according to a recently proposed classification schema, which was expanded to accommodate new findings. In addition, detailed annotations were performed in a subset of 321 proteins. These annotations feature information on start and end positions for the repeat regions and units. RepeatsDB is an ongoing effort to systematically classify and annotate structural protein repeats in a consistent way. It provides users with the possibility to access and download high-quality datasets either interactively or programmatically through web services. PMID:24311564

  8. Cardiovascular Effects of 1 Year of Alagebrium and Endurance Exercise Training in Healthy Older Individuals

    PubMed Central

    Fujimoto, Naoki; Hastings, Jeffrey L.; Carrick-Ranson, Graeme; Shafer, Keri M.; Shibata, Shigeki; Bhella, Paul S.; Abdullah, Shuaib M.; Barkley, Kyler W.; Adams-Huet, Beverley; Boyd, Kara N.; Livingston, Sheryl A.; Palmer, Dean; Levine, Benjamin D.

    2014-01-01

    Background Lifelong exercise training maintains a youthful compliance of the left ventricle (LV), whereas a year of exercise training started later in life fails to reverse LV stiffening, possibly because of accumulation of irreversible advanced glycation end products. Alagebrium breaks advanced glycation end product crosslinks and improves LV stiffness in aged animals. However, it is unclear whether a strategy of exercise combined with alagebrium would improve LV stiffness in sedentary older humans. Methods and Results Sixty-two healthy subjects were randomized into 4 groups: sedentary+placebo; sedentary+alagebrium (200 mg/d); exercise+placebo; and exercise+alagebrium. Subjects underwent right heart catheterization to define LV pressure–volume curves; secondary functional outcomes included cardiopulmonary exercise testing and arterial compliance. A total of 57 of 62 subjects (67±6 years; 37 f/20 m) completed 1 year of intervention followed by repeat measurements. Pulmonary capillary wedge pressure and LV end-diastolic volume were measured at baseline, during decreased and increased cardiac filling. LV stiffness was assessed by the slope of LV pressure–volume curve. After intervention, LV mass and end-diastolic volume increased and exercise capacity improved (by ≈8%) only in the exercise groups. Neither LV mass nor exercise capacity was affected by alagebrium. Exercise training had little impact on LV stiffness (training×time effect, P=0.46), whereas alagebrium showed a modest improvement in LV stiffness compared with placebo (medication×time effect, P=0.04). Conclusions Alagebrium had no effect on hemodynamics, LV geometry, or exercise capacity in healthy, previously sedentary seniors. However, it did show a modestly favorable effect on age-associated LV stiffening. PMID:24130005

  9. 3D MRI volume sizing of knee meniscus cartilage.

    PubMed

    Stone, K R; Stoller, D W; Irving, S G; Elmquist, C; Gildengorin, G

    1994-12-01

    Meniscal replacement by allograft and meniscal regeneration through collagen meniscal scaffolds have been recently reported. To evaluate the effectiveness of a replaced or regrown meniscal cartilage, a method for measuring the size and function of the regenerated tissue in vivo is required. To solve this problem, we developed and evaluated a magnetic resonance imaging (MRI) technique to measure the volume of meniscal tissues. Twenty-one intact fresh cadaver knees were evaluated and scanned with MRI for meniscal volume sizing. The sizing sequence was repeated six times for each of 21 lateral and 12 medial menisci. The menisci were then excised and measured by water volume displacement. Each volume displacement measurement was repeated six times. The MRI technique employed to measure the volume of the menisci was shown to correspond to that of the standard measure of volume and was just as precise. However, the MRI technique consistently underestimated the actual volume. The average of the coefficient of variation for lateral volumes was 0.04 and 0.05 for the water and the MRI measurements, respectively. For medial measurements it was 0.04 and 0.06. The correlation for the lateral menisci was r = 0.45 (p = 0.04) and for the medial menisci it was r = 0.57 (p = 0.05). We conclude that 3D MRI is precise and repeatable but not accurate when used to measure meniscal volume in vivo and therefore may only be useful for evaluating changes in meniscal allografts and meniscal regeneration templates over time.

  10. Longitudinal fMRI analysis: A review of methods

    PubMed Central

    Skup, Martha

    2010-01-01

    Functional magnetic resonance imaging (fMRI) investigations of a longitudinal nature, where participants are scanned repeatedly over time and imaging data are obtained at more than one time-point, are essential to understanding functional changes and development in healthy and pathological brains. The main objective of this paper is to provide a brief summary of common longitudinal analysis approaches, develop an overview of fMRI by introducing how such data manifest, and explore the statistical challenges that arise at the intersection of these two techniques. PMID:21691445

  11. Longitudinal fMRI analysis: A review of methods

    PubMed Central

    Skup, Martha

    2011-01-01

    Functional magnetic resonance imaging (fMRI) investigations of a longitudinal nature, where participants are scanned repeatedly over time and imaging data are obtained at more than one time-point, are essential to understanding functional changes and development in healthy and pathological brains. The main objective of this paper is to provide a brief summary of common longitudinal analysis approaches, develop an overview of fMRI by introducing how such data manifest, and explore the statistical challenges that arise at the intersection of these two techniques. PMID:22655113

  12. Repeated exposure of the developing rat brain to magnetic resonance imaging did not affect neurogenesis, cell death or memory function

    SciTech Connect

    Zhu, Changlian; Gao, Jianfeng; Li, Qian; Huang, Zhiheng; Zhang, Yu; Li, Hongfu; Kuhn, Hans-Georg; Blomgren, Klas

    2011-01-07

    Research highlights: {yields} The effect of MRI on the developing brain is a matter of debate. {yields} Repeated exposure to MRI did not affect neurogenesis. {yields} Memory function was not affected by repeated MRI during development. {yields} Neither late gestation nor young postnatal brains were affected by MRI. {yields} Repeated MRI did not cause cell death in the neurogenic region of the hippocampus. -- Abstract: The effect of magnetic fields on the brain is a matter of debate. The objective of this study was to investigate whether repeated exposure to strong magnetic fields, such as during magnetic resonance imaging (MRI), could elicit changes in the developing rat brain. Embryonic day 15 (E15) and postnatal day 14 (P14) rats were exposed to MRI using a 7.05 T MR system. The animals were anesthetized and exposed for 35 min per day for 4 successive days. Control animals were anesthetized but no MRI was performed. Body temperature was maintained at 37 {sup o}C. BrdU was injected after each session (50 mg/kg). One month later, cell proliferation, neurogenesis and astrogenesis in the dentate gyrus were evaluated, revealing no effects of MRI, neither in the E15, nor in the P14 group. DNA damage in the dentate gyrus in the P14 group was evaluated on P18, 1 day after the last session, using TUNEL staining. There was no difference in the number of TUNEL-positive cells after MRI compared with controls, neither in mature neurons, nor in newborn progenitors (BrdU/TUNEL double-labeled cells). Novel object recognition was performed to assess memory function 1 month after MRI. There was no difference in the recognition index observed after MRI compared with the control rats, neither for the E15, nor for the P14 group. In conclusion, repeated exposure to MRI did not appear to affect neurogenesis, cell death or memory function in rats, neither in late gestation (E15-E18) nor in young postnatal (P14-P17) rats.

  13. Saturation of repeated quantum measurements

    NASA Astrophysics Data System (ADS)

    Haapasalo, Erkka; Heinosaari, Teiko; Kuramochi, Yui

    2016-08-01

    We study sequential measurement scenarios where the system is repeatedly subjected to the same measurement process. We first provide examples of such repeated measurements where further repetitions of the measurement do not increase our knowledge on the system after some finite number of measurement steps. We also prove, however, that repeating the Lüders measurement of an unsharp two-outcome observable never saturates in this sense, and we characterize the observable measured in the limit of infinitely many repetitions. Our result implies that a repeated measurement can be used to correct the inherent noise of an unsharp observable.

  14. To Repeat or Not to Repeat a Course

    ERIC Educational Resources Information Center

    Armstrong, Michael J.; Biktimirov, Ernest N.

    2013-01-01

    The difficult transition from high school to university means that many students need to repeat (retake) 1 or more of their university courses. The authors examine the performance of students repeating first-year core courses in an undergraduate business program. They used data from university records for 116 students who took a total of 232…

  15. DWI Repeaters and Non-Repeaters: A Comparison.

    ERIC Educational Resources Information Center

    Weeber, Stan

    1981-01-01

    Discussed how driving-while-intoxicated (DWI) repeaters differed signigicantly from nonrepeaters on 4 of 23 variables tested. Repeaters were more likely to have zero or two dependent children, attend church frequently, drink occasionally and have one or more arrests for public intoxication. (Author)

  16. MRI of the lung: state of the art.

    PubMed

    Wielpütz, Mark; Kauczor, Hans-Ulrich

    2012-01-01

    Magnetic resonance imaging (MRI) of the lung is technically challenging due to the low proton density and fast signal decay of the lung parenchyma itself. Additional challenges consist of tissue loss, hyperinflation, and hypoxic hypoperfusion, e.g., in emphysema, a so-called "minus-pathology". However, pathological changes resulting in an increase of tissue ("plus-pathology"), such as atelectases, nodules, infiltrates, mucus, or pleural effusion, are easily depicted with high diagnostic accuracy. Although MRI is inferior or at best equal to multi-detector computed tomography (MDCT) for the detection of subtle morphological features, MRI now offers an increasing spectrum of functional imaging techniques such as perfusion assessment and measurement of ventilation and respiratory mechanics that are superior to what is possible with MDCT. Without putting patients at risk with ionizing radiation, repeated examinations allow for the evaluation of the course of lung disease and monitoring of the therapeutic response through quantitative imaging, providing a level of functional detail that cannot be obtained by any other single imaging modality. As such, MRI will likely be used for clinical applications beyond morphological imaging for many lung diseases. In this article, we review the technical aspects and protocol suggestions for chest MRI and discuss the role of MRI in the evaluation of nodules and masses, airway disease, respiratory mechanics, ventilation, perfusion and hemodynamics, and pulmonary vasculature. PMID:22434450

  17. Polarized noble gas MRI

    SciTech Connect

    Brookeman, James R.; Mugler, John P. III; Lange, Eduard E. de; Knight-Scott, Jack; Maier, Therese; Bogorad, Paul; Driehuys, Bastiaan; Cates, Gordon; Happer, William; Daniel, Thomas M.; Truwit, Jonathon D.

    1998-01-20

    The development of convenient methods to polarize liter quantities of the noble gases helium-3 and xenon-129 has provided the opportunity for a new MRI method to visualize the internal air spaces of the human lung. These spaces are usually poorly seen with hydrogen-based MRI, because of the limited water content of the lung and the low thermal polarization of the water protons achieved in conventional magnets. In addition, xenon, which has a relatively high solubility and a sufficiently persistent polarization level in blood and biological tissue, offers the prospect of providing perfusion images of the lung, brain and other organs.

  18. MRI of the brain (image)

    MedlinePlus

    An MRI (magnetic resonance imaging) of the brain creates a detailed image of the complex structures in the brain. An MRI can give a three-dimensional depiction of the brain, making location of problems such ...

  19. Bone Mineral Density at Diagnosis of Celiac Disease and after 1 Year of Gluten-Free Diet

    PubMed Central

    Pantaleoni, Stefano; Luchino, Massimo; Adriani, Alessandro; Pellicano, Rinaldo; Stradella, Davide; Ribaldone, Davide Giuseppe; Sapone, Nicoletta; Isaia, Gian Carlo; Di Stefano, Marco; Astegiano, Marco

    2014-01-01

    Atypical or silent celiac disease may go undiagnosed for many years and can frequently lead to loss of bone mineral density, with evolution to osteopenia or osteoporosis. The prevalence of the latter conditions, in case of new diagnosis of celiac disease, has been evaluated in many studies but, due to the variability of epidemiologic data and patient features, the results are contradictory. The aim of this study was to evaluate bone mineral density by dual-energy X-ray absorptiometry in 175 consecutive celiac patients at time of diagnosis (169 per-protocol, 23 males, 146 females; average age 38.9 years). Dual-energy X-ray absorptiometry was repeated after 1 year of gluten-free diet in those with T-score value <−1 at diagnosis. Stratification of patients according to sex and age showed a higher prevalence of low bone mineral density in men older than 30 years and in women of all ages. A 1-year gluten-free diet led to a significant improvement in lumbar spine and femoral neck mean T-score value. We propose that dual-energy X-ray absorptiometry should be performed at diagnosis of celiac disease in all women and in male aged >30 years, taking into account each risk factor in single patients. PMID:25379519

  20. Nifty Nines and Repeating Decimals

    ERIC Educational Resources Information Center

    Brown, Scott A.

    2016-01-01

    The traditional technique for converting repeating decimals to common fractions can be found in nearly every algebra textbook that has been published, as well as in many precalculus texts. However, students generally encounter repeating decimal numerals earlier than high school when they study rational numbers in prealgebra classes. Therefore, how…

  1. Estimating repeatability of egg size

    USGS Publications Warehouse

    Flint, P.L.; Rockwell, R.F.; Sedinger, J.S.

    2001-01-01

    Measures of repeatability have long been used to assess patterns of variation in egg size within and among females. We compared different analytical approaches for estimating repeatability of egg size of Black Brant. Separate estimates of repeatability for eggs of each clutch size and laying sequence number varied from 0.49 to 0.64. We suggest that using the averaging egg size within clutches results in underestimation of variation within females and thereby overestimates repeatability. We recommend a nested design that partitions egg-size variation within clutches, among clutches within females, and among females. We demonstrate little variation in estimates of repeatability resulting from a nested model controlling for egg laying sequence and a nested model in which we assumed laying sequence was unknown.

  2. All-photonic quantum repeaters.

    PubMed

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories.

  3. All-photonic quantum repeaters

    PubMed Central

    Azuma, Koji; Tamaki, Kiyoshi; Lo, Hoi-Kwong

    2015-01-01

    Quantum communication holds promise for unconditionally secure transmission of secret messages and faithful transfer of unknown quantum states. Photons appear to be the medium of choice for quantum communication. Owing to photon losses, robust quantum communication over long lossy channels requires quantum repeaters. It is widely believed that a necessary and highly demanding requirement for quantum repeaters is the existence of matter quantum memories. Here we show that such a requirement is, in fact, unnecessary by introducing the concept of all-photonic quantum repeaters based on flying qubits. In particular, we present a protocol based on photonic cluster-state machine guns and a loss-tolerant measurement equipped with local high-speed active feedforwards. We show that, with such all-photonic quantum repeaters, the communication efficiency scales polynomially with the channel distance. Our result paves a new route towards quantum repeaters with efficient single-photon sources rather than matter quantum memories. PMID:25873153

  4. MRI in decompression illness.

    PubMed

    Hierholzer, J; Tempka, A; Stroszczynski, C; Amodio, F; Hosten, N; Haas, J; Felix, R

    2000-05-01

    We report a case of decompression illness in which the patient developed paraparesis during scuba diving after rapid ascent. MRI of the spine revealed a focal intramedullary lesion consistent with the symptoms. The pathophysiological and radiological aspects of spinal decompression illness are discussed.

  5. Structural brain MRI trait polygenic score prediction of cognitive abilities

    PubMed Central

    Luciano, Michelle; Marioni, Riccardo E; Hernández, Maria Valdés; Maniega, Susana Munoz; Hamilton, Iona F; Royle, Natalie A.; Scotland, Generation; Chauhan, Ganesh; Bis, Joshua C.; Debette, Stephanie; DeCarli, Charles; Fornage, Myriam; Schmidt, Reinhold; Ikram, M. Arfan; Launer, Lenore J.; Seshadri, Sudha; Bastin, Mark E.; Porteous, David J.; Wardlaw, Joanna; Deary, Ian J

    2016-01-01

    Structural brain magnetic resonance imaging (MRI) traits share part of their genetic variance with cognitive traits. Here, we use genetic association results from large meta-analytic studies of genome-wide association for brain infarcts, white matter hyperintensities, intracranial, hippocampal and total brain volumes to estimate polygenic scores for these traits in three Scottish samples: Generation Scotland: Scottish Family Health Study (GS:SFHS), and the Lothian Birth Cohorts of 1936 (LBC1936) and 1921 (LBC1921). These five brain MRI trait polygenic scores were then used to 1) predict corresponding MRI traits in the LBC1936 (numbers ranged 573 to 630 across traits) and 2) predict cognitive traits in all three cohorts (in 8,115 to 8,250 persons). In the LBC1936, all MRI phenotypic traits were correlated with at least one cognitive measure; and polygenic prediction of MRI traits was observed for intracranial volume. Meta-analysis of the correlations between MRI polygenic scores and cognitive traits revealed a significant negative correlation (maximal r=0.08) between the hippocampal volume polygenic score and measures of global cognitive ability collected in childhood and in old age in the Lothian Birth Cohorts. The lack of association to a related general cognitive measure when including the GS:SFHS points to either type 1 error or the importance of using prediction samples that closely match the demographics of the genome-wide association samples from which prediction is based. Ideally, these analyses should be repeated in larger samples with data on both MRI and cognition, and using MRI GWA results from even larger meta-analysis studies. PMID:26427786

  6. Procedural Learning and Associative Memory Mechanisms Contribute to Contextual Cueing: Evidence from fMRI and Eye-Tracking

    ERIC Educational Resources Information Center

    Manelis, Anna; Reder, Lynne M.

    2012-01-01

    Using a combination of eye tracking and fMRI in a contextual cueing task, we explored the mechanisms underlying the facilitation of visual search for repeated spatial configurations. When configurations of distractors were repeated, greater activation in the right hippocampus corresponded to greater reductions in the number of saccades to locate…

  7. Protein Repeats from First Principles.

    PubMed

    Turjanski, Pablo; Parra, R Gonzalo; Espada, Rocío; Becher, Verónica; Ferreiro, Diego U

    2016-01-01

    Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family. PMID:27044676

  8. Protein Repeats from First Principles.

    PubMed

    Turjanski, Pablo; Parra, R Gonzalo; Espada, Rocío; Becher, Verónica; Ferreiro, Diego U

    2016-04-05

    Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family.

  9. Protein Repeats from First Principles

    PubMed Central

    Turjanski, Pablo; Parra, R. Gonzalo; Espada, Rocío; Becher, Verónica; Ferreiro, Diego U.

    2016-01-01

    Some natural proteins display recurrent structural patterns. Despite being highly similar at the tertiary structure level, repeating patterns within a single repeat protein can be extremely variable at the sequence level. We use a mathematical definition of a repetition and investigate the occurrences of these in sequences of different protein families. We found that long stretches of perfect repetitions are infrequent in individual natural proteins, even for those which are known to fold into structures of recurrent structural motifs. We found that natural repeat proteins are indeed repetitive in their families, exhibiting abundant stretches of 6 amino acids or longer that are perfect repetitions in the reference family. We provide a systematic quantification for this repetitiveness. We show that this form of repetitiveness is not exclusive of repeat proteins, but also occurs in globular domains. A by-product of this work is a fast quantification of the likelihood of a protein to belong to a family. PMID:27044676

  10. Eosinophilic granuloma: MRI manifestations.

    PubMed

    Beltran, J; Aparisi, F; Bonmati, L M; Rosenberg, Z S; Present, D; Steiner, G C

    1993-01-01

    The appearance on magnetic resonance imaging (MRI) of 16 cases of pathologically proven eosinophilic granuloma were reviewed retrospectively and correlated with the radiographic appearance of the lesion. The most common MR appearance (ten cases) was a focal lesion, surrounded by an extensive, ill-defined bone marrow and soft tissue reaction with low signal intensity on T1-weighted images and high signal intensity on T2-weighted images, considered to represent bone marrow and soft tissue edema (the flare phenomenon). The MRI manifestations of eosinophilic granuloma, especially during the early stages, are nonspecific, and may stimulate an aggressive lesion such as osteomyelitis or Ewings sarcoma, or other benign bone tumors such as osteoid osteoma or chondroblastoma. PMID:8480200

  11. MRI of the penis.

    PubMed

    Kirkham, A

    2012-11-01

    MRI of the penis is an expensive test that is not always superior to clinical examination or ultrasound. However, it shows many of the important structures, and in particular the combination of tumescence from intracavernosal alprostadil, and high-resolution T(2) sequences show the glans, corpora and the tunica albuginea well. In this paper we summarise the radiological anatomy and discuss the indications for MRI. For penile cancer, it may be useful in cases where the local stage is not apparent clinically. In priapism, it is an emerging technique for assessing corporal viability, and in fracture it can in most cases make the diagnosis and locate the injury. In some cases of penile fibrosis and Peyronie's disease, it may aid surgical planning, and in complex pelvic fracture may replace or augment conventional urethrography. It is an excellent investigation for the malfunctioning penile prosthesis.

  12. SU-E-J-192: Verification of 4D-MRI Internal Target Volume Using Cine MRI

    SciTech Connect

    Lafata, K; Czito, B; Palta, M; Bashir, M; Yin, F; Cai, J

    2014-06-01

    Purpose: To investigate the accuracy of 4D-MRI in determining the Internal Target Volume (ITV) used in radiation oncology treatment planning of liver cancers. Cine MRI is used as the standard baseline in establishing the feasibility and accuracy of 4D-MRI tumor motion within the liver. Methods: IRB approval was obtained for this retrospective study. Analysis was performed on MR images from four patients receiving external beam radiation therapy for liver cancer at our institution. Eligible patients received both Cine and 4D-MRI scans before treatment. Cine images were acquired sagittally in real time at a slice bisecting the tumor, while 4D images were acquired volumetrically. Cine MR DICOM headers were manipulated such that each respiratory frame was assigned a unique slice location. This approach permitted the treatment planning system (Eclipse, Varian Medical Systems) to recognize a complete respiratory cycle as a “volume”, where the gross tumor was contoured temporally. Software was developed to calculate the union of all frame contours in the structure set, resulting in the corresponding plane of the ITV projecting through the middle of the tumor, defined as the Internal Target Area (ITA). This was repeated for 4D-MRI, at the corresponding slice location, allowing a direct comparison of ITAs obtained from each modality. Results: Four patients have been analyzed. ITAs contoured from 4D-MRI correlate with contours from Cine MRI. The mean error of 4D values relative to Cine values is 7.67 +/− 2.55 %. No single ITA contoured from 4D-MRI demonstrated more than 10.5 % error compared to its Cine MRI counterpart. Conclusion: Motion management is a significant aspect of treatment planning within dynamic environments such as the liver, where diaphragmatic and cardiac activity influence plan accuracy. This small pilot study suggests that 4D-MRI based ITA measurements agree with Cine MRI based measurements, an important step towards clinical implementation. NIH 1R21

  13. Post-stroke aphasia recovery assessed with fMRI and a picture identification task

    PubMed Central

    Szaflarski, Jerzy P.; Eaton, Kenneth; Ball, Angel L.; Banks, Christi; Vannest, Jennifer; Allendorfer, Jane B.; Page, Stephen; Holland, Scott K.

    2010-01-01

    Background Stroke patients often display deficits in language function such as correctly naming objects. Our aim was to evaluate the reliability and the patterns of post-stroke language recovery using a picture identification task during fMRI at 4T. Material and Methods 4 healthy and 4 left MCA stroke subjects with chronic (>1 year) aphasia. Ten fMRI scans were performed for each subject over a 10-week period using a picture identification task. Active condition involved presenting subjects with a panel of 4 figures (e.g., drawings of 4 animals) every 6 seconds; subjects indicated which figure matched the written name in the center. Control condition was same/different judgment task of pairs of geometric figures (squares, octagons or combination) presented every 6 seconds. Thirty-second active/control blocks were repeated 5 times each; responses were recorded. Results Patients and controls exhibited similar demographic characteristics: age (46 vs. 53 years), personal handedness (EHI; 89 vs. 95), familial handedness (93 vs. 95) or years of education (14.3 vs. 14.8). For the active condition, controls performed better than patients (97.7% vs. 89.1%, p<0.001); performance was similar for the control condition (99.5% vs. 98.8%, p=0.23). During fMRI, controls exhibited bilateral, L>R positive blood oxygenation-level dependent (BOLD) activations in frontal and temporal language areas and symmetric retro-splenial and posterior cingulate areas and symmetric negative BOLD activations in bilateral fronto-temporal language networks. However, the patient group showed positive BOLD activations predominantly in peri-stroke areas and negative BOLD activations in the unaffected (right) hemisphere. Both the control and patient groups displayed high activation reliability (as measured by the ICC) in left frontal and temporal language areas, although the ICC in frontal regions of the patients was spread over a much larger peri-stroke area. Conclusion This study documents the utility

  14. Superconducting magnets for MRI

    SciTech Connect

    Williams, J.E.

    1984-08-01

    Three types of magnets are currently used to provide the background field required for magnet resonance imaging (MRI). (i) Permanent magnets produce fields of up to 0.3 T in volumes sufficient for imaging the head or up to 0.15 T for whole body imaging. Cost and simplicity of operation are advantages, but relatively low field, weight (up to 100 tonnes) and, to a small extent, instability are limitations. (ii) Water-cooled magnets provide fields of up to 0.25 T in volumes suitable for whole body imaging, but at the expense of power (up to 150 kW for 0.25 T) and water-cooling. Thermal stability of the field requires the maintenance of constant temperature through periods both of use and of quiescence. (iii) Because of the limitations imposed by permanent and resistive magnets, particularly on field strength, the superconducting magnet is now most widely used to provide background fields of up to 2 T for whole body MRI. It requires very low operating power and that only for refrigeration. Because of the constant low temperature, 4.2 K, at which its stressed structure operates, its field is stable. The following review deals principally with superconducting magnets for MRI. However, the sections on field analysis apply to all types of magnet and the description of the source terms of circular coils and of the principals of design of solenoids apply equally to resistive solenoidal magnets.

  15. MRI characteristics of fourth ventricle arachnoid diverticula in five dogs.

    PubMed

    Bazelle, Julien; Caine, Abby; Palus, Viktor; Summers, Brian A; Cherubini, Giunio B

    2015-01-01

    Intracranial arachnoid diverticula (cysts) are rare accumulations of cerebrospinal fluid (CSF) within the arachnoid membrane. The purpose of this retrospective study was to describe magnetic resonance imaging (MRI) characteristics of fourth ventricle arachnoid diverticula in a group of dogs. The hospital's medical records were searched for dogs with MRI studies of the brain and a diagnosis of fourth ventricle arachnoid diverticulum. Clinical characteristics were recorded from medical records and MRI studies were reinterpreted by a board-certified veterinary radiologist. Five pediatric dogs fulfilled inclusion criteria. Clinical signs included cervical hyperaesthesia, obtundation, tetraparesis, and/or central vestibular syndrome. In all five dogs, MRI findings were consistent with obstructive hydrocephalus, based on dilation of all ventricles and compression of the cerebellum and brainstem. All five dogs also had cervical syringohydromyelia, with T2-weighted hyperintensity of the gray matter of the cord adjacent to the syringohydromyelia. A signal void, interpreted as flow disturbance, was observed at the mesencephalic aqueduct in all dogs. Four dogs underwent surgical treatment with occipitalectomy and durotomy. A cystic lesion emerging from the fourth ventricle was detected in all four dogs during surgery and histopathology confirmed the diagnosis of arachnoid diverticula. Three dogs made excellent recovery but deteriorated shortly after surgery and were euthanized. Repeat MRI in two dogs revealed improved hydrocephalus but worsening of the syringohydromyelia. Findings from the current study supported theories that fourth ventricle arachnoid diverticula are secondary to partial obstruction of the central canal or lateral apertures and that arachnoid diverticula are developmental lesions in dogs.

  16. Repeat endocarditis: analysis of risk factors based on the International Collaboration on Endocarditis - Prospective Cohort Study.

    PubMed

    Alagna, L; Park, L P; Nicholson, B P; Keiger, A J; Strahilevitz, J; Morris, A; Wray, D; Gordon, D; Delahaye, F; Edathodu, J; Miró, J M; Fernández-Hidalgo, N; Nacinovich, F M; Shahid, R; Woods, C W; Joyce, M J; Sexton, D J; Chu, V H

    2014-06-01

    Repeat episodes of infective endocarditis (IE) can occur in patients who survive an initial episode. We analysed risk factors and 1-year mortality of patients with repeat IE. We considered 1874 patients enrolled in the International Collaboration on Endocarditis - Prospective Cohort Study between January 2000 and December 2006 (ICE-PCS) who had definite native or prosthetic valve IE and 1-year follow-up. Multivariable analysis was used to determine risk factors for repeat IE and 1-year mortality. Of 1874 patients, 1783 (95.2%) had single-episode IE and 91 (4.8%) had repeat IE: 74/91 (81%) with new infection and 17/91 (19%) with presumed relapse. On bivariate analysis, repeat IE was associated with haemodialysis (p 0.002), HIV (p 0.009), injection drug use (IDU) (p < 0.001), Staphylococcus aureus IE (p 0.003), healthcare acquisition (p 0.006) and previous IE before ICE enrolment (p 0.001). On adjusted analysis, independent risk factors were haemodialysis (OR, 2.5; 95% CI, 1.2-5.3), IDU (OR, 2.9; 95% CI, 1.6-5.4), previous IE (OR, 2.8; 95% CI, 1.5-5.1) and living in the North American region (OR, 1.9; 95% CI, 1.1-3.4). Patients with repeat IE had higher 1-year mortality than those with single-episode IE (p 0.003). Repeat IE is associated with IDU, previous IE and haemodialysis. Clinicians should be aware of these risk factors in order to recognize patients who are at risk of repeat IE.

  17. Intraoperative MRI and functional mapping.

    PubMed

    Gasser, Thomas; Szelenyi, Andrea; Senft, Christian; Muragaki, Yoshihiro; Sandalcioglu, I Erol; Sure, Ulrich; Nimsky, Christopher; Seifert, Volker

    2011-01-01

    The integration of functional and anatomical data into neuronavigation is an established standard of care in many neurosurgical departments. Yet, this method has limitations as in most cases the data are acquired prior to surgery. Due to brain-shift the accurate presentation of functional as well as anatomical structures declines in the course of surgery. In consequence, the acquisition of information during surgery about the brain's current functional state is of specific interest. The advancement of imaging technologies (e.g. fMRI, MEG, Intraoperative Optical Intrinsic Signal Imaging--IOIS) and neurophysiological techniques and the advent of intraoperative MRI all had a major impact on neurosurgery. The combination of modalities such as neurophysiology and intraoperative MRI (ioMRI), as well as the acquisition of functional MRI during surgery (ifMRI) are in the focus of this work. Especially the technical aspects and safety issues are elucidated.

  18. Sodium MRI: Methods and applications

    PubMed Central

    Madelin, Guillaume; Lee, Jae-Seung; Regatte, Ravinder R.; Jerschow, Alexej

    2014-01-01

    Sodium NMR spectroscopy and MRI have become popular in recent years through the increased availability of high-field MRI scanners, advanced scanner hardware and improved methodology. Sodium MRI is being evaluated for stroke and tumor detection, for breast cancer studies, and for the assessment of osteoarthritis and muscle and kidney functions, to name just a few. In this article, we aim to present an up-to-date review of the theoretical background, the methodology, the challenges and limitations, and current and potential new applications of sodium MRI. PMID:24815363

  19. Limitations on quantum key repeaters.

    PubMed

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-04-23

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol.

  20. Limitations on quantum key repeaters.

    PubMed

    Bäuml, Stefan; Christandl, Matthias; Horodecki, Karol; Winter, Andreas

    2015-01-01

    A major application of quantum communication is the distribution of entangled particles for use in quantum key distribution. Owing to noise in the communication line, quantum key distribution is, in practice, limited to a distance of a few hundred kilometres, and can only be extended to longer distances by use of a quantum repeater, a device that performs entanglement distillation and quantum teleportation. The existence of noisy entangled states that are undistillable but nevertheless useful for quantum key distribution raises the question of the feasibility of a quantum key repeater, which would work beyond the limits of entanglement distillation, hence possibly tolerating higher noise levels than existing protocols. Here we exhibit fundamental limits on such a device in the form of bounds on the rate at which it may extract secure key. As a consequence, we give examples of states suitable for quantum key distribution but unsuitable for the most general quantum key repeater protocol. PMID:25903096

  1. Gradient echo MRI

    PubMed Central

    Copenhaver, B R.; Shin, J; Warach, S; Butman, J A.; Saver, J L.; Kidwell, C S.

    2009-01-01

    Background: Recent studies have demonstrated that gradient echo (GRE) MRI sequences are as accurate as CT for the detection of intracerebral hemorrhage (ICH) in the context of acute stroke. However, many physicians who currently read acute stroke imaging studies may be unfamiliar with interpretation of GRE images. Methods: An NIH Web-based training program was developed including a pretest, tutorial, and posttest. Physicians involved in the care of acute stroke patients were encouraged to participate. The tutorial covered acute, chronic, and mimic hemorrhages as they appear on CT, diffusion-weighted imaging, and GRE sequences. Ability of users to identify ICH presence, type, and age on GRE was compared from the pretest to posttest timepoint. Results: A total of 104 users completed the tutorial. Specialties represented included general radiology (42%), general neurology (16%), neuroradiology (15%), stroke neurology (14%), emergency medicine (1%), and other (12%). Median overall score improved pretest to posttest from 66.7% to 83.3%, p < 0.001. Improvement by category was as follows: acute ICH, 66.7%–100%, p < 0.001; chronic ICH, 33.3%–66.7%, p < 0.001; ICH negatives/mimics, 100%–100%, p = 0.787. Sensitivity for identification of acute hemorrhage improved from 68.2% to 96.4%. Conclusions: Physicians involved in acute stroke care achieved significant improvement in gradient echo (GRE) hemorrhage interpretation after completing the NIH GRE MRI tutorial. This indicates that a Web-based tutorial may be a viable option for the widespread education of physicians to achieve an acceptable level of diagnostic accuracy at reading GRE MRI, thus enabling confident acute stroke treatment decisions. GLOSSARY AHA/ASA = American Heart Association/American Stroke Association; CME = continuing medical education; DWI = diffusion-weighted imaging; GRE = gradient echo; ICH = intracerebral hemorrhage; tPA = tissue plasminogen activator. PMID:19414724

  2. Occupational exposure in MRI

    PubMed Central

    Mcrobbie, D W

    2012-01-01

    This article reviews occupational exposure in clinical MRI; it specifically considers units of exposure, basic physical interactions, health effects, guideline limits, dosimetry, results of exposure surveys, calculation of induced fields and the status of the European Physical Agents Directive. Electromagnetic field exposure in MRI from the static field B0, imaging gradients and radiofrequency transmission fields induces electric fields and currents in tissue, which are responsible for various acute sensory effects. The underlying theory and its application to the formulation of incident and induced field limits are presented. The recent International Commission on Non-Ionizing Radiation Protection (ICNIRP) Bundesministerium für Arbeit und Soziales and Institute of Electrical and Electronics Engineers limits for incident field exposure are interpreted in a manner applicable to MRI. Field measurements show that exposure from movement within the B0 fringe field can exceed ICNIRP reference levels within 0.5 m of the bore entrance. Rate of change of field dB/dt from the imaging gradients is unlikely to exceed the new limits, although incident field limits can be exceeded for radiofrequency (RF) exposure within 0.2–0.5 m of the bore entrance. Dosimetric surveys of routine clinical practice show that staff are exposed to peak values of 42±24% of B0, with time-averaged exposures of 5.2±2.8 mT for magnets in the range 0.6–4 T. Exposure to time-varying fields arising from movement within the B0 fringe resulted in peak dB/dt of approximately 2 T s−1. Modelling of induced electric fields from the imaging gradients shows that ICNIRP-induced field limits are unlikely to be exceeded in most situations; however, movement through the static field may still present a problem. The likely application of the limits is discussed with respect to the reformulation of the European Union (EU) directive and its possible implications for MRI. PMID:22457400

  3. Nanoformulations for molecular MRI

    PubMed Central

    Tu, Chuqiao; Louie, Angelique Y.

    2012-01-01

    Nanoscale contrast agents have shown the ability to increase the detection sensitivity of MRI by several orders of magnitude, endowing this traditionally macroscopic modality with the ability to observe unique molecular signatures. Herein, we describe three types of nanoparticulate contrast agents: iron oxide nanoparticles, gadolinium-based nanoparticles, and bio-essential manganese, cobalt, nickel, and copper ion-containing nanoformulations. Some of these agents have been approved for clinical use, but more are still under development for medical imaging. The advantages and disadvantages of each nanoformulation, in terms of intrinsic magnetism, ease of synthesis, and biodistribution, etc. are discussed. PMID:22488901

  4. Screening for refractive errors at age 1 year: a pilot study.

    PubMed Central

    Ingram, R M; Traynar, M J; Walker, C; Wilson, J M

    1979-01-01

    Cycloplegic refraction of 1-year-old children is technically possible and is acceptable to mothers as a method for screening children for visual defects. The range of refractions found in a sample of 186 1-year-old children is reported. Prediction of which children are significantly at risk for squint and/or amblyopia is possible on the basis of refractions at age 1 year according to the criteria selected for an 'abnormal' refraction. Bilateral hypermetropia and/or astigmatism or anisometropia at age 1 year was significantly (P less than 1 in 10 000) associated with a child eventually being found to have squint or amblyopia. Both the age of screening and criteria of abnormality will probably need modification. +2.50 or more D hypermetropia in any one meridian of either eye at age 1 year was even more significantly (P = 0.000 000 05%) associated with squint and/or amblyopia. The possibility that meridional hypermetropia could be the basic defect in squint and amblyopia is discussed. PMID:435441

  5. 1 year test-retest reliability of ImPACT in professional ice hockey players.

    PubMed

    Bruce, Jared; Echemendia, Ruben; Meeuwisse, Willem; Comper, Paul; Sisco, Amber

    2014-01-01

    The Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery is widely used to assess neurocognitive outcomes following sports-related concussion. The purpose of this study was to examine the 1 year test-retest reliability of ImPACT in a multilingual sample of professional hockey players. A total of 305 professional hockey players were tested 1 year apart using ImPACT. Reliable change confidence intervals were calculated and test-retest reliability was measured using Pearson and Intraclass correlation coefficients. Results indicated that the 1-year test-retest reliabilities for the Visual Motor and Reaction Time Composites ranged from low to high (.52 to .81). In contrast, 1-year test-retest reliabilities for the Verbal and Visual Memory Composites were low (.22 to .58). The 1-year test-retest results provided mixed support for the use of Visual Motor and Reaction Time Composites in select samples; in contrast, the Verbal and Visual Memory Composites may not be sensitive to clinical change.

  6. Multiparametric MRI and targeted prostate biopsy: Improvements in cancer detection, localization, and risk assessment

    PubMed Central

    Bjurlin, Marc A.; Mendhiratta, Neil; Wysock, James S.

    2016-01-01

    Introduction Multiparametric-MRI (mp-MRI) is an evolving noninvasive imaging modality that increases the accurate localization of prostate cancer at the time of MRI targeted biopsy, thereby enhancing clinical risk assessment, and improving the ability to appropriately counsel patients regarding therapy. Material and methods We used MEDLINE/PubMed to conduct a comprehensive search of the English medical literature. Articles were reviewed, data was extracted, analyzed, and summarized. In this review, we discuss the mp-MRI prostate exam, its role in targeted prostate biopsy, along with clinical applications and outcomes of MRI targeted biopsies. Results Mp-MRI, consisting of T2-weighted imaging, diffusion-weighted imaging, dynamic contrast-enhanced imaging, and possibly MR spectroscopy, has demonstrated improved specificity in prostate cancer detection as compared to conventional T2-weighted images alone. An MRI suspicion score has been developed and is depicted using an institutional Likert or, more recently, a standardized reporting scale (PI-RADS). Techniques of MRI-targeted biopsy include in-gantry MRI guided biopsy, TRUS-guided visual estimation biopsy, and software co-registered MRI-US guided biopsy (MRI-US fusion). Among men with no previous biopsy, MRI-US fusion biopsy demonstrates up to a 20% increase in detection of clinically significant cancers compared to systematic biopsy while avoiding a significant portion of low risk disease. These data suggest a potential role in reducing over-detection and, ultimately, over-treatment. Among men with previous negative biopsy, 72–87% of cancers detected by MRI targeted biopsy are clinically significant. Among men with known low risk cancer, repeat biopsy by MR-targeting improves risk stratification in selecting men appropriate for active surveillance secondarily reducing the need for repetitive biopsy during surveillance. Conclusions Use of mp-MRI for targeting prostate biopsies has the potential to reduce the

  7. Hyperoxia and Functional MRI.

    PubMed

    Bulte, Daniel

    2016-01-01

    Oxygen plays a fundamental role in functional magnetic resonance imaging (FMRI). Blood oxygenation level-dependent (BOLD) imaging is the foundation stone of all FMRI and is still the essential workhorse of the vast majority of FMRI procedures. Hemoglobin may provide the magnetic properties that allow the technique to work, but it is oxygen that allows the contrast to effectively be switched on or off, and it is oxygen that we are interested in tracking in order to observe the oxygen metabolism changes. In general the changes in venous oxygen saturation are observed in order to infer changes in the correlated mechanisms, which can include changes in cerebral blood flow, metabolism, and the fraction of inspired oxygen. By independently manipulating the fraction of inspired oxygen it is possible to alter the amount of dissolved oxygen in the plasma, the venous saturation, or even the blood flow. The effects that these changes have on the observed MRI signal can be either a help or a hindrance depending on how well the changes induced are understood. The administration of supplemental inspired oxygen is in a unique position to provide a flexible, noninvasive, inexpensive, patient-friendly addition to the MRI toolkit to enable investigations to look beyond statistics and regions of interest, and actually produce calibrated, targeted measurements of blood flow, metabolism or pathology. PMID:27343097

  8. Nonalcoholic Fatty Liver Disease Is Associated With Higher 1-year All-Cause Rehospitalization Rates in Patients Admitted for Acute Heart Failure

    PubMed Central

    Valbusa, Filippo; Bonapace, Stefano; Grillo, Cristina; Scala, Luca; Chiampan, Andrea; Rossi, Andrea; Zoppini, Giacomo; Lonardo, Amedeo; Arcaro, Guido; Byrne, Christopher D.; Targher, Giovanni

    2016-01-01

    Abstract Repeat hospitalization due to acute heart failure (HF) is a global public health problem that markedly impacts on health resource use. Identifying novel predictors of rehospitalization would help physicians to determine the optimal postdischarge plan for preventing HF rehospitalization. Nonalcoholic fatty liver disease (NAFLD) is an emerging risk factor for many heart diseases, including HF. We assessed whether NAFLD at hospital admission predicts 1-year all-cause rehospitalization in patients with acute HF. We enrolled all patients consecutively admitted for acute HF to our General Medicine Division, from January 2013 to April 2014, after excluding patients with acute myocardial infarction, severe heart valve diseases, malignancy, known liver diseases, and those with volume overload related to extracardiac causes. NAFLD was diagnosed by ultrasonography and exclusion of competing etiologies. The primary outcome of the study was the 1-year all-cause rehospitalization rate. Among the 107 patients enrolled in the study, the cumulative rehospitalization rate was 12.1% at 1 month, 25.2% at 3 months, 29.9% at 6 months, and 38.3% at 1 year. Patients with NAFLD had markedly higher 1-year rehospitalization rates than those without NAFLD (58% vs 21% at 1 y; P < 0.001 by the log-rank test). Cox regression analysis revealed that NAFLD was associated with a 5.5-fold increased risk of rehospitalization (adjusted hazard ratio 5.56, 95% confidence interval 2.46–12.1, P < 0.001) after adjustment for multiple HF risk factors and potential confounders. In conclusion, NAFLD was independently associated with higher 1-year rehospitalization in patients hospitalized for acute HF. PMID:26886619

  9. Do Twelfths Terminate or Repeat?

    ERIC Educational Resources Information Center

    Ambrose, Rebecca; Burnison, Erica

    2015-01-01

    When finding the decimal equivalent of a fraction with 12 in the denominator, will it terminate or repeat? This question came from a seventh grader in author Erica Burnison's class as the student was pondering a poster generated by one of her classmates. Not only was the question intriguing, but it also affirmed the belief in the power of…

  10. 78 FR 65594 - Vehicular Repeaters

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-01

    ... mobile repeaters by public safety licensees on certain frequencies in the VHF band. DATES: Submit..., CART, etc.) by email: FCC504@fcc.gov or phone: 202-418- 0530 or TTY: 202-418-0432. For detailed... Proceedings, 63 FR 24121 (May 1, 1998). Electronic Filers: Comments may be filed electronically using...

  11. Repeat Pregnancies among Adolescent Mothers.

    ERIC Educational Resources Information Center

    Gillmore, Mary Rogers; Lewis, Steven M.; Lohr, Mary Jane; Spencer, Michael S.; White, Rachelle D.

    1997-01-01

    Reports the results of an event history analysis of rapidly repeated pregnancies among a sample of 170 adolescents. Results show that the best fitting model for these girls included two proximate determinants of pregnancy, contraceptive use, and other factors. Findings indicate that such pregnancies among teenagers are somewhat predictable. (RJM)

  12. "I was born full deaf." Written language outcomes after 1 year of strategic and interactive writing instruction.

    PubMed

    Wolbers, Kimberly A; Dostal, Hannah M; Bowers, Lisa M

    2012-01-01

    Nonstandard grammatical forms are often present in the writing of deaf students that are rarely, if ever, seen in the writing of hearing students. With the implementation of Strategic and Interactive Writing Instruction (SIWI) in previous studies, students have demonstrated significant gains in high-level writing skills (e.g., text structure) but have also made gains with English grammar skills. This 1-year study expands on prior research by longitudinally examining the written language growth (i.e., writing length, sentence complexity, sentence awareness, and function words) of 29 deaf middle-school students. A repeated-measures analysis of variance with a between-subjects variable for literacy achievement level was used to examine gains over time and the intervention's efficacy when used with students of various literacy levels. Students, whether high or low achieving, demonstrated statistically significant gains with writing length, sentence complexity, and sentence awareness. Subordinate clauses were found to be an area of difficulty, and follow up strategies are suggested. An analysis of function word data, specifically prepositions and articles, revealed different patterns of written language growth by language group (e.g., American Sign Language users, oral students, users of English-based sign).

  13. The Effects of Acupressure Training on Sleep Quality and Cognitive Function of Older Adults: A 1-Year Randomized Controlled Trial.

    PubMed

    Zeng, Hui; Liu, Mengjiao; Wang, Ping; Kang, Jiaxun; Lu, Fenghua; Pan, Lu

    2016-10-01

    We explored the effects of acupressure training on older adults' sleep quality and cognitive function. Ninety older adults with impaired sleep quality were selected from screened volunteers and randomly divided into equal control and experimental groups; 82 completed the 1-year follow-up. Participants in the control group were given instructions on sleep health, while those in the experimental group received sleep health instructions plus individual and small group acupressure training sessions and support to practice the intervention on their own each day. All participants were assessed by trained assistants blind to study group allocation using Chinese versions of the Pittsburgh Sleep Quality Index, the Epworth Sleepiness Scale, the Mini-Mental State Examination, and four subscales from the revised Chinese version of the Wechsler Memory Scale, at baseline and at 3, 6, and 12 months. Repeated measures analysis of variance showed that acupressure training improved older adults' sleep quality and cognitive function, but the mediating effect of sleep on the relationship between acupressure training and cognitive function was not supported. Given the ease, simplicity, and safety of acupressure training observed with community-dwelling older adults in China, attempts should be made to replicate these preliminary positive findings with larger samples. © 2016 Wiley Periodicals, Inc. PMID:27327537

  14. Pentapeptide Repeat Proteins and Cyanobacteria

    SciTech Connect

    Buchko, Garry W.

    2009-10-16

    Cyanobacteria are unique in many ways and one unusual feature is the presence of a suite of proteins that contain at least one domain with a minimum of eight tandem repeated five-residues (Rfr) of the general consensus sequence A[N/D]LXX. The function of such pentapeptide repeat proteins (PRPs) are still unknown, however, their prevalence in cyanobacteria suggests that they may play some role in the unique biological activities of cyanobacteria. As part of an inter-disciplinary Membrane Biology Grand Challenge at the Environmental Molecular Sciences Laboratory (Pacific Northwest National Laboratory) and Washington University in St. Louis, the genome of Cyanothece 51142 was sequenced and its molecular biology studied with relation to circadian rhythms. The genome of Cyanothece encodes for 35 proteins that contain at least one PRP domain. These proteins range in size from 105 (Cce_3102) to 930 (Cce_2929) kDa with the PRP domains ranging in predicted size from 12 (Cce_1545) to 62 (cce_3979) tandem pentapeptide repeats. Transcriptomic studies with 29 out of the 35 genes showed that at least three of the PRPs in Cyanothece 51142 (cce_0029, cce_3083, and cce_3272) oscillated with repeated periods of light and dark, further supporting a biological function for PRPs. Using X-ray diffraction crystallography, the structure for two pentapeptide repeat proteins from Cyanothece 51142 were determined, cce_1272 (aka Rfr32) and cce_4529 (aka Rfr23). Analysis of their molecular structures suggests that all PRP may share the same structural motif, a novel type of right-handed quadrilateral β-helix, or Rfr-fold, reminiscent of a square tower with four distinct faces. Each pentapeptide repeat occupies one face of the Rfr-fold with four consecutive pentapeptide repeats completing a coil that, in turn, stack upon each other to form “protein skyscrapers”. Details of the structural features of the Rfr-fold are reviewed here together with a discussion for the possible role of end

  15. Evaluation of the management of Hr-HPV+/PapTest- women: results at 1-year recall

    PubMed Central

    Chiappetta, Caterina; Puggioni, Chiara; Lendaro, Eugenio; Cacciotti, Jessica; Zaralli, Roberto; Migliore, Giovanna; Bellardini, Paola; Petrozza, Vincenzo; Della Rocca, Carlo; Di Cristofano, Claudio

    2015-01-01

    With cervical cancer screening the choice of 1-year as a period of follow-up in positive high-risk HPV women without cytological lesions is still under discussion. We evaluated the management of these women and the role of HPV genotyping test. We did a cervical cancer screening study of women aged 35-64 with primary high-risk HPV test. Women positive for high-risk HPV with negative cytology were followed-up after 1 year. In this study we selected women with high-risk HPV+/PapTest- resulted high-risk HPV+ at recall and performed the PapTest and HPV genotyping test. The detection rate of squamous high grade (CIN2+) relative to the total screened cohort was 2.1‰, and it was 0.2‰ at the 1-year recall. The colposcopy performed in women referred at the 1-year recall accounted for 48.8% of the total (baseline + 1-year recall), and 84.3% of these women had no cytological lesions. The most frequent hr-HPV genotype detected was HPV16 and 66.7% of co-infections were due to HPV16 and HPV18. 54.5% of women presented a persistent infection at 1-year recall with the same HPV subtype, 50% of persistent infections was due to HPV16 and 16.7% of these were determined to be CIN2+ histological lesions. Our data show that it may be useful to extend the period of follow-up for women hr-HPV+/PapTest- so as to reduce the number of unnecessary colposcopies due to the transitory infections and that the genotyping test could help to identify the persistent infections in which HPV16 is involved. PMID:26884886

  16. [Repeated head injury during judo practice].

    PubMed

    Fujiwara, Kazue

    2014-01-01

    Mild traumatic brain injuries, if repeated, can cause permanent brain damage, or even death. I examined five published documents(three judicial decisions, one official injury report, and one book)to analyze incidents in which high school students who, while practicing judo, experienced acute subdural hematoma(ASDH)with grave outcomes, despite the fact that they had been examined by neurosurgeons. The five students, first-grade boy and girl of junior high school and two first-grade boys and one second-grade girl of senior high school, were hit on the head during extracurricular judo practice and were taken to the neurosurgery department of different hospitals. They were all novices or unskilled players. The initial diagnoses were ASDH in three cases, concussion in one, and headache in one. Although the surgeons, except in one case, prohibited the students from returning to play, the juveniles resumed judo practice soon. Some of them complained of continued headaches, but they kept practicing. Between 17 and 82 days after the first injury, they received the fateful hits to their heads, and they were brought to the emergency rooms. MRI and CT revealed ASDH in all;two of them died, and the other three remain in persistent vegetative state. Neurosurgeons should take the initiative to prevent severe brain injury of young athletes through collaborations with the athletes themselves, fellow athletes, family members, coaches, teachers, athletic directors, and other physicians. They should pay close attention to headaches and other signs and symptoms of concussion and prohibit the athletes from returning to play until they are confirmed to be symptom free for recommended periods, insisting that safety comes first. PMID:24388944

  17. Segmentation precision of abdominal anatomy for MRI-based radiotherapy

    SciTech Connect

    Noel, Camille E.; Zhu, Fan; Lee, Andrew Y.; Yanle, Hu; Parikh, Parag J.

    2014-10-01

    The limited soft tissue visualization provided by computed tomography, the standard imaging modality for radiotherapy treatment planning and daily localization, has motivated studies on the use of magnetic resonance imaging (MRI) for better characterization of treatment sites, such as the prostate and head and neck. However, no studies have been conducted on MRI-based segmentation for the abdomen, a site that could greatly benefit from enhanced soft tissue targeting. We investigated the interobserver and intraobserver precision in segmentation of abdominal organs on MR images for treatment planning and localization. Manual segmentation of 8 abdominal organs was performed by 3 independent observers on MR images acquired from 14 healthy subjects. Observers repeated segmentation 4 separate times for each image set. Interobserver and intraobserver contouring precision was assessed by computing 3-dimensional overlap (Dice coefficient [DC]) and distance to agreement (Hausdorff distance [HD]) of segmented organs. The mean and standard deviation of intraobserver and interobserver DC and HD values were DC{sub intraobserver} = 0.89 ± 0.12, HD{sub intraobserver} = 3.6 mm ± 1.5, DC{sub interobserver} = 0.89 ± 0.15, and HD{sub interobserver} = 3.2 mm ± 1.4. Overall, metrics indicated good interobserver/intraobserver precision (mean DC > 0.7, mean HD < 4 mm). Results suggest that MRI offers good segmentation precision for abdominal sites. These findings support the utility of MRI for abdominal planning and localization, as emerging MRI technologies, techniques, and onboard imaging devices are beginning to enable MRI-based radiotherapy.

  18. Anatomical evaluation of CT-MRI combined femoral model

    PubMed Central

    Lee, Yeon S; Seon, Jong K; Shin, Vladimir I; Kim, Gyu-Ha; Jeon, Moongu

    2008-01-01

    Background Both CT and MRI are complementary to each other in that CT can produce a distinct contour of bones, and MRI can show the shape of both ligaments and bones. It will be ideal to build a CT-MRI combined model to take advantage of complementary information of each modality. This study evaluated the accuracy of the combined femoral model in terms of anatomical inspection. Methods Six normal porcine femora (180 ± 10 days, 3 lefts and 3 rights) with ball markers were scanned by CT and MRI. The 3D/3D registration was performed by two methods, i.e. the landmark-based 3 points-to-3 points and the surface matching using the iterative closest point (ICP) algorithm. The matching accuracy of the combined model was evaluated with statistical global deviation and locally measure anatomical contour-based deviation. Statistical analysis to assess any significant difference between accuracies of those two methods was performed using univariate repeated measures ANOVA with the Turkey post hoc test. Results This study revealed that the local 2D contour-based measurement of matching deviation was 0.5 ± 0.3 mm in the femoral condyle, and in the middle femoral shaft. The global 3D contour matching deviation of the landmark-based matching was 1.1 ± 0.3 mm, but local 2D contour deviation through anatomical inspection was much larger as much as 3.0 ± 1.8 mm. Conclusion Even with human-factor derived errors accumulated from segmentation of MRI images, and limited image quality, the matching accuracy of CT-&-MRI combined 3D models was 0.5 ± 0.3 mm in terms of local anatomical inspection. PMID:18234068

  19. Segmentation precision of abdominal anatomy for MRI-based radiotherapy.

    PubMed

    Noel, Camille E; Zhu, Fan; Lee, Andrew Y; Yanle, Hu; Parikh, Parag J

    2014-01-01

    The limited soft tissue visualization provided by computed tomography, the standard imaging modality for radiotherapy treatment planning and daily localization, has motivated studies on the use of magnetic resonance imaging (MRI) for better characterization of treatment sites, such as the prostate and head and neck. However, no studies have been conducted on MRI-based segmentation for the abdomen, a site that could greatly benefit from enhanced soft tissue targeting. We investigated the interobserver and intraobserver precision in segmentation of abdominal organs on MR images for treatment planning and localization. Manual segmentation of 8 abdominal organs was performed by 3 independent observers on MR images acquired from 14 healthy subjects. Observers repeated segmentation 4 separate times for each image set. Interobserver and intraobserver contouring precision was assessed by computing 3-dimensional overlap (Dice coefficient [DC]) and distance to agreement (Hausdorff distance [HD]) of segmented organs. The mean and standard deviation of intraobserver and interobserver DC and HD values were DC(intraobserver) = 0.89 ± 0.12, HD(intraobserver) = 3.6mm ± 1.5, DC(interobserver) = 0.89 ± 0.15, and HD(interobserver) = 3.2mm ± 1.4. Overall, metrics indicated good interobserver/intraobserver precision (mean DC > 0.7, mean HD < 4mm). Results suggest that MRI offers good segmentation precision for abdominal sites. These findings support the utility of MRI for abdominal planning and localization, as emerging MRI technologies, techniques, and onboard imaging devices are beginning to enable MRI-based radiotherapy.

  20. Directionality switchable gain stabilized linear repeater

    NASA Astrophysics Data System (ADS)

    Ota, Takayuki; Ohmachi, Tadashi; Aida, Kazuo

    2004-10-01

    We propose a new approach to realize a bidirectional linear repeater suitable for future optical internet networks and fault location in repeater chain with OTDR. The proposed approach is the linear repeater of simple configuration whose directionality is rearranged dynamically by electrical control signal. The repeater is composed of a magneto-optical switch, a circulator, a dynamically gain stabilized unidirectional EDFA, and control circuits. The repeater directionality is rearranged as fast as 0.1ms by an electrical control pulse. It is experimentally confirmed that OTDR with the directionality switchable repeater is feasible for repeater chain. The detailed design and performance of the repeater are also discussed, including the multi-pass interference (MPI) which may arise in the proposed repeater, the effect of the MPI on SNR degradation of the repeater chain and the feed-forward EDFA gain control circuit.

  1. Latent Classes of Adolescent Posttraumatic Stress Disorder Predict Functioning and Disorder after 1 Year

    ERIC Educational Resources Information Center

    Ayer, Lynsay; Danielson, Carla Kmett; Amstadter, Ananda B.; Ruggiero, Ken; Saunders, Ben; Kilpatrick, Dean

    2011-01-01

    Objective: To identify latent classes of posttraumatic stress disorder (PTSD) symptoms in a national sample of adolescents, and to test their associations with PTSD and functional impairment 1 year later. Method: A total of 1,119 trauma-exposed youth aged 12 through 17 years (mean = 14.99 years, 51% female and 49% male) participating in the…

  2. Verbal Labels Modulate Perceptual Object Processing in 1-Year-Old Children

    ERIC Educational Resources Information Center

    Gliga, Teodora; Volein, Agnes; Csibra, Gergely

    2010-01-01

    Whether verbal labels help infants visually process and categorize objects is a contentious issue. Using electroencephalography, we investigated whether possessing familiar or novel labels for objects directly enhances 1-year-old children's neural processes underlying the perception of those objects. We found enhanced gamma-band (20-60 Hz)…

  3. An Analysis of 1-Year Impacts of Youth Transition Demonstration Projects

    ERIC Educational Resources Information Center

    Fraker, Thomas M.; Luecking, Richard G.; Mamun, Arif A.; Martinez, John M.; Reed, Deborah S.; Wittenburg, David C.

    2016-01-01

    This article examines the impacts of the Youth Transition Demonstration, an initiative of the Social Security Administration (SSA) to improve employment outcomes for youth with disabilities. Based on a random assignment design, the analysis uses data from a 1-year follow-up survey and SSA administrative records for 5,203 youth in six research…

  4. Thai Adolescent Survivors 1 Year after the 2004 Tsunami: A Mixed Methods Study

    ERIC Educational Resources Information Center

    Tuicomepee, Arunya; Romano, John L.

    2008-01-01

    This study examined the impact of the 2004 Asian tsunami on 400 Thai adolescents 1 year after the disaster. Quantitative analyses showed that youth behavior problems were positively associated with tsunami experiences and negatively associated with positive family functioning. Tsunami exposure, school connectedness, religious beliefs and…

  5. Results with SynCardia total artificial heart beyond 1 year.

    PubMed

    Torregrossa, Gianluca; Morshuis, Michiel; Varghese, Robin; Hosseinian, Leila; Vida, Vladimiro; Tarzia, Vincenzo; Loforte, Antonio; Duveau, Daniel; Arabia, Francisco; Leprince, Pascal; Kasirajan, Vigneshwa; Beyersdorf, Friedhelm; Musumeci, Francesco; Hetzer, Roland; Krabatsch, Thoamas; Gummert, Jan; Copeland, Jack; Gerosa, Gino

    2014-01-01

    Mechanical circulatory support devices have been increasingly used for long-term support. We reviewed outcomes in all patients supported with a SynCardia total artificial heart (TAH) for more than 1 year to assess its safety in long-term support. As of December 2011, all 47 patients who received the TAH from 10 centers worldwide were included in this retrospective study. Clinical data were collected on survival, infections, thromboembolic and hemorrhagic events, device failures, and antithrombotic therapy. The mean age of patients was 50 ± 1.57 years, the median support time was 554 days (range 365-1373 days). The primary diagnosis was dilated cardiomiopathy in 23 patients, ischemic in 15, and "other" in 9. After a minimum of 1 year of support, 34 patients (72%) were successfully transplanted, 12 patients (24%) died while on device support, and 1 patient (2%) is still supported. Five patients (10%) had a device failure reported. Major complications were as follows: systemic infections in 25 patients (53%), driveline infections in 13 patients (27%), thromboembolic events in 9 patients (19%), and hemorrhagic events in 7 patients (14%). SynCardia TAH has proven to be a reliable and effective device in replacing the entire heart. In patients who reached a minimum of 1 year of support, device failure rate is acceptable and only in two cases was the leading cause of death. Infections and hemorrhagic events were the major causes of death. Patients who remain supported beyond 1 year are still likely to survive to transplantation.

  6. Dialectical Behavior Therapy for Adolescents with Bipolar Disorder: A 1-Year Open Trial

    ERIC Educational Resources Information Center

    Goldstein, Tina R.; Axelson, David A.; Birmaher, Boris; Brent, David A.

    2007-01-01

    Objective: To describe an adapted version of dialectical behavior therapy for adolescents with bipolar disorder. Method: The dialectical behavior therapy intervention is delivered over 1 year and consists of two modalities: family skills training (conducted with individual family units) and individual therapy. The acute treatment period (6 months)…

  7. Outpatient treated burns in infants younger than 1 year in Helsinki during 2005-2009.

    PubMed

    Laitakari, Elina; Koljonen, Virve; Pyörälä, Sari; Rintala, Risto

    2014-05-01

    In general, voluminous data exists concerning burns in children, but the data focusing specially on children less than 1 year of age is sporadic. We therefore focused on examining the special features of burns in children less than 1 year of age. A retrospective study of all outpatient treated burn patients <1 year old at the Hospital for Children and Adolescents, Helsinki, Finland, from January 2005 to December 2009 was performed. During the 5-year period we identified 106 outpatient treated infants with burns, representing 15% of all pediatric burns during the study period. The majority was male and aged 9-12 months. Most of the burns occurred at home, and in most cases a caregiver was present in the injury room. Scalds were the most common type of injury followed by contact burns. The most common source of scald was from cups containing hot drink, and the most common source of contact burn was hot stoves or oven doors. Special attention needs to be targeted toward the prevention of burns in children less than 1 year of age. The majority of the injuries could have been prevented with more vigilance.

  8. Magnetostimulation in MRI.

    PubMed

    Irnich, W; Schmitt, F

    1995-05-01

    In national and international bodies, there is active discussion of appropriate safety regulations of levels of magnetic field strength in MRI. Present limits are usually expressed in terms of the switching rate dB/dt, but the validity of this is open to debate. Application of the fundamental law of electrostimulation is well-established, both on theoretical and experimental grounds. Application of this law, in combination with Maxwell's law, yields a very simple equation that we call the fundamental law of magnetostimulation. This law has the hyperbolic form of a strength-duration curve and allows an estimation of the lowest possible value of the magnetic flux density capable of stimulating nerves and muscles. Calculations prove that the threshold for heart excitation is much higher than those for nerve and muscle stimulations. Experimental results from us and other authors confirm the correctness of the derived laws for magnetostimulation. In light of these findings, proposed safety limits should be reconsidered. PMID:7596265

  9. Visualizing Hyolaryngeal Mechanics in Swallowing Using Dynamic MRI

    PubMed Central

    Pearson, William G.; Zumwalt, Ann C.

    2013-01-01

    Introduction Coordinates of anatomical landmarks are captured using dynamic MRI to explore whether a proposed two-sling mechanism underlies hyolaryngeal elevation in pharyngeal swallowing. A principal components analysis (PCA) is applied to coordinates to determine the covariant function of the proposed mechanism. Methods Dynamic MRI (dMRI) data were acquired from eleven healthy subjects during a repeated swallows task. Coordinates mapping the proposed mechanism are collected from each dynamic (frame) of a dynamic MRI swallowing series of a randomly selected subject in order to demonstrate shape changes in a single subject. Coordinates representing minimum and maximum hyolaryngeal elevation of all 11 subjects were also mapped to demonstrate shape changes of the system among all subjects. MophoJ software was used to perform PCA and determine vectors of shape change (eigenvectors) for elements of the two-sling mechanism of hyolaryngeal elevation. Results For both single subject and group PCAs, hyolaryngeal elevation accounted for the first principal component of variation. For the single subject PCA, the first principal component accounted for 81.5% of the variance. For the between subjects PCA, the first principal component accounted for 58.5% of the variance. Eigenvectors and shape changes associated with this first principal component are reported. Discussion Eigenvectors indicate that two-muscle slings and associated skeletal elements function as components of a covariant mechanism to elevate the hyolaryngeal complex. Morphological analysis is useful to model shape changes in the two-sling mechanism of hyolaryngeal elevation. PMID:25090608

  10. Linewidth narrowing for 31Phosphorus MRI of cell membranes

    NASA Astrophysics Data System (ADS)

    Barrett, Sean; Frey, Merideth; Madri, Joseph; Michaud, Michael

    2011-03-01

    Most 31 P Magnetic Resonance Spectroscopy studies of tissues try to avoid contamination by a relatively large, but broad, spectral feature attributed to cell membrane phospholipids. MRI using this broad 31 P membrane spectrum is not even attempted, since the spatial resolution and signal-to-noise would be poor, relative to conventional MRI using the narrow 1 H water spectrum. This long-standing barrier has been overcome by a novel pulse sequence, recently discovered in fundamental quantum computation research, which narrows the broad 31 P spectrum by ~ 1000 × . Applying time-dependent gradients in synch with a repeating pulse block enables a new route to high spatial resolution, 3D 31 P MRI of the soft solid components of cells and tissues. So far, intact and sectioned samples of ex vivo fixed mouse organs have been imaged, with (sub-mm)3 voxels. Extending the reach of MRI to broad spectra in natural and artificial tissues opens a new window into cells, enabling progress in biomedical research. W.J. Thoma et al., J. MR 61, 141 (1985); E.J. Murphy et al., MR Med 12, 282 (1989); R. McNamara et al., NMR Biomed 7, 237 (1994).

  11. MRI probes for sensing biologically relevant metal ions.

    PubMed

    Bonnet, Célia S; Tóth, Eva

    2010-03-01

    Given the important role of metal ions in fundamental biological processes, the visualization of their concentration in living animals by repeatable, noninvasive imaging techniques, such as MRI, would be highly desirable. A large number of metal-responsive MRI contrast agents, the majority based on Gd(3+) complexes, have been reported in recent years. The contrast-enhancing properties (relaxivity) of a Gd(3+) complex can be most conveniently modulated by interaction with the sensed metal cation via changes in the number of water molecules bound directly to Gd(3+) or changes in the size of the complex, which represent the two major strategies to develop metal sensitive MRI probes. Here, we survey paramagnetic lanthanide complexes involving Gd(3+) agents and paramagnetic chemical exchange saturation transfer probes designed to detect the most important endogenous metal ions: calcium, zinc, iron and copper. Future work will likely focus on extending applications of these agents to living animals, as well as on exploring new ways of creating molecular MRI probes in order to meet requirements such as higher specificity or lower detection limits.

  12. Observations of Soft Gamma Repeaters

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2004-01-01

    Magnetars (Soft Gamma Repeaters and Anomalous X-ray Pulsars) are a subclass of neutron stars characterized by their recurrent X-ray bursts. While in an active (bursting) state (lasting anywhere between days and years), they are emit&ng hundreds of predominantly soft (kT=30 kev), short (0.1-100 ms long) events. Their quiescent source x-ray light ewes exhibit puhlions rotational period rate changes (spin-down) indicate that their magnetic fields are extremely high, of the order of 10^14- 10^l5 G. Such high B-field objects, dubbed "magnetars", had been predicted to exist in 1992, but the first concrete observational evidence were obtained in 1998 for two of these sources. I will discuss here the history of Soft Gamma Repeaters, and their spectral, timing and flux characteristics both in the persistent and their burst emission.

  13. Changes in echocardiographic measures of systolic and diastolic function in children 1 year after hematopoietic SCT.

    PubMed

    Daly, K P; Colan, S D; Blume, E D; Margossian, R; Gauvreau, K; Duncan, C; Lehmann, L E; Chen, M H

    2011-12-01

    Hematopoietic SCT (HSCT) is a life-saving therapy in children, but has been associated with heart failure. Little is known about subclinical changes in cardiac function. We examined changes in systolic and diastolic function from pre- to 1-year post HSCT by echocardiography. All patients (n=74, 61% men, median age 9.1 years, mean left-ventricular (LV) ejection fraction 61.3±4.9%) who underwent HSCT at Children's Hospital Boston between 2005 and 2008, were <21 years at time of HSCT, and had routine pre- and 1-year post echocardiograms were included. Systolic function parameters, including LV ejection fraction, rate-corrected velocity of fiber shortening (Vcfc) and stress-velocity index and diastolic parameters, including tissue Doppler imaging (TDI)-derived velocities, and left-ventricular flow propagation, were compared before and after transplant. At 1-year post HSCT, systolic function, as measured by Vcfc (1.10±0.15 vs 1.04±0.12 circ/s; P=0.03) and stress-velocity index (z-score 0.40±1.4 vs -0.20±1.1; P=0.02), had worsened; diastolic function parameters, including mitral E' velocity (16.6±3.9 vs 15.0±3.4 cm/s; P=0.01) and tricuspid E' velocity (14.3±3.6 vs 12.4±2.8 cm/s; P=0.002) had also decreased. At 1-year post HSCT, children have subclinical declines in systolic and diastolic function. These small changes might become clinically important over time. Serial non-invasive assessment of cardiac function should be considered in all children following HSCT.

  14. Hematuria duration does not predict kidney function at 1 year in ANCA-associated glomerulonephritis

    PubMed Central

    Chen, Teresa K.; Murakami, Christine; Manno, Rebecca L.; Geetha, Duvuru

    2015-01-01

    Objectives Hematuria is considered a marker of active renal disease in ANCA-associated glomerulonephritis (ANCA-GN) with induction immunosuppression often continued until hematuria has resolved. We aim to determine whether longer hematuria duration is associated with lower estimated glomerular filtration rate (eGFR) at 1 year. Methods We conducted a retrospective study of 55 patients with biopsy-proven ANCA-GN. Linear regression models were constructed to determine predictors of eGFR at 1 year. The primary exposure was hematuria (>5 rbc/hpf) duration, defined as <90 days vs. ≥90 days following renal biopsy. Covariates included age, gender, ANCA type, baseline eGFR, and baseline proteinuria. Results Mean age at diagnosis was 58 years (53% male, 80% Caucasian, 38% PR3-ANCA, and 45% MPO-ANCA). At baseline, all patients had hematuria, 95% had proteinuria, and mean serum creatinine was 3.1 [standard deviation (SD) = 2.3] mg/dL. Overall, 93% were treated with steroids in combination with either cyclophosphamide or rituximab. Mean hematuria duration was 92 (SD = 77) days with 34 (62%) patients having hematuria resolution within 90 days. Older age and lower baseline eGFR were associated with lower eGFR at 1 year (p = 0.03 and p < 0.001, respectively). Hematuria resolution (<90 days vs. ≥90 days) was not predictive of eGFR at 1 year (p = 0.93). Conclusions In ANCA-GN, hematuria duration does not predict eGFR at 1 year. Our findings provide support that among individuals who are otherwise considered to be in clinical remission, the persistence of hematuria should not delay transition from induction to maintenance immunosuppression. PMID:24775913

  15. fMRI adaptation revisited.

    PubMed

    Larsson, Jonas; Solomon, Samuel G; Kohn, Adam

    2016-07-01

    Adaptation has been widely used in functional magnetic imaging (fMRI) studies to infer neuronal response properties in human cortex. fMRI adaptation has been criticized because of the complex relationship between fMRI adaptation effects and the multiple neuronal effects that could underlie them. Many of the longstanding concerns about fMRI adaptation have received empirical support from neurophysiological studies over the last decade. We review these studies here, and also consider neuroimaging studies that have investigated how fMRI adaptation effects are influenced by high-level perceptual processes. The results of these studies further emphasize the need to interpret fMRI adaptation results with caution, but they also provide helpful guidance for more accurate interpretation and better experimental design. In addition, we argue that rather than being used as a proxy for measurements of neuronal stimulus selectivity, fMRI adaptation may be most useful for studying population-level adaptation effects across cortical processing hierarchies.

  16. MRI of plants and foods

    NASA Astrophysics Data System (ADS)

    Van As, Henk; van Duynhoven, John

    2013-04-01

    The importance and prospects for MRI as applied to intact plants and to foods are presented in view of one of humanity's most pressing concerns, the sustainable and healthy feeding of a worldwide increasing population. Intact plants and foods have in common that their functionality is determined by complex multiple length scale architectures. Intact plants have an additional level of complexity since they are living systems which critically depend on transport and signalling processes between and within tissues and organs. The combination of recent cutting-edge technical advances and integration of MRI accessible parameters has the perspective to contribute to breakthroughs in understanding complex regulatory plant performance mechanisms. In food science and technology MRI allows for quantitative multi-length scale structural assessment of food systems, non-invasive monitoring of heat and mass transport during shelf-life and processing, and for a unique view on food properties under shear. These MRI applications are powerful enablers of rationally (re)designed food formulations and processes. Limitations and bottlenecks of the present plant and food MRI methods are mainly related to short T2 values and susceptibility artefacts originating from small air spaces in tissues/materials. We envisage cross-fertilisation of solutions to overcome these hurdles in MRI applications in plants and foods. For both application areas we witness a development where MRI is moving from highly specialised equipment to mobile and downscaled versions to be used by a broad user base in the field, greenhouse, food laboratory or factory.

  17. A repeating fast radio burst.

    PubMed

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star. PMID:26934226

  18. A repeating fast radio burst.

    PubMed

    Spitler, L G; Scholz, P; Hessels, J W T; Bogdanov, S; Brazier, A; Camilo, F; Chatterjee, S; Cordes, J M; Crawford, F; Deneva, J; Ferdman, R D; Freire, P C C; Kaspi, V M; Lazarus, P; Lynch, R; Madsen, E C; McLaughlin, M A; Patel, C; Ransom, S M; Seymour, A; Stairs, I H; Stappers, B W; van Leeuwen, J; Zhu, W W

    2016-03-10

    Fast radio bursts are millisecond-duration astronomical radio pulses of unknown physical origin that appear to come from extragalactic distances. Previous follow-up observations have failed to find additional bursts at the same dispersion measure (that is, the integrated column density of free electrons between source and telescope) and sky position as the original detections. The apparent non-repeating nature of these bursts has led to the suggestion that they originate in cataclysmic events. Here we report observations of ten additional bursts from the direction of the fast radio burst FRB 121102. These bursts have dispersion measures and sky positions consistent with the original burst. This unambiguously identifies FRB 121102 as repeating and demonstrates that its source survives the energetic events that cause the bursts. Additionally, the bursts from FRB 121102 show a wide range of spectral shapes that appear to be predominantly intrinsic to the source and which vary on timescales of minutes or less. Although there may be multiple physical origins for the population of fast radio bursts, these repeat bursts with high dispersion measure and variable spectra specifically seen from the direction of FRB 121102 support an origin in a young, highly magnetized, extragalactic neutron star.

  19. Serial MRI and CSF analysis in a dog treated with intrathecal amphotericin B for protothecosis.

    PubMed

    Young, Martin; Bush, William; Sanchez, Melissa; Gavin, Pat; Williams, Mathew

    2012-01-01

    A 3 yr old female spayed English setter mixed-breed dog presented with diarrhea, weight loss, side stepping to the right, and a right head tilt. Rectal and cerebrospinal fluid cytology and culture confirmed a diagnosis of Prototheca zopfii. MRI of the brain showed inflammation of the brain and meninges, ventriculomegaly, and syringomyelia. Treatment with prednisone, itraconazole, and amphotericin B lipid complex administered intrathecally yielded transient improvement. Progressive brainstem signs were noted, and a repeat MRI and cerebrospinal fluid analysis documented persistent disease. This is the first description of the MRI findings and treatment with intrathecal amphoteracin B lipid complex for protothecosis of the central nervous system. Protothecosis should be considered in dogs with chronic diarrhea and compatible MRI findings. PMID:22267176

  20. Three-dimensional assessment of mandibular advancement 1 year after surgery

    PubMed Central

    de Assis Ribeiro Carvalho, Felipe; Cevidanes, Lucia Helena Soares; Motta, Alexandre Trindade Simões da; de Oliveira Almeida, Marco Antonio; Phillips, Ceib

    2010-01-01

    Introduction This prospective observational study evaluated changes in the 3-dimensional position and remodeling of the mandibular rami, condyles, and chin at splint removal and 1 year after mandibular advancement surgery. Methods Presurgery, splint removal (4–6 weeks postsurgery), and 1-year postsurgery cone-beam computed tomography scans of 27 subjects were used. Superimposition on the cranial base was used to assess positional or remodeling changes in the anatomic regions of interest. Surface distance displacements were visually displayed and quantified by 3-dimensional color maps. A 1-sample t test was used to assess the average postsurgical changes of each region of interest. The level of significance was set at 0.05. Results After antero-inferior chin displacement with surgery (mean, 6.81 ± 3.2 mm at splint removal), the average 1-year post-surgery displacement was not statistically significant (P = 0.44). Postsurgical adaptations greater than 2 mm were observed in 48% of the patients: 16% with an additional anterior-inferior displacement of the chin of 2 to 4 mm, and 4% with ≥4 mm; 20% had postero-superior movement of 2 to 4 mm, and 8% had postero-superior movement of ≥4 mm. The condyles tended to move, on average, ≤2 mm supero-posteriorly with surgery, and this small positional displacement was maintained 1 year postsurgery (right condyle, P = 0.58; left, P = 0.88). The rami exhibited outward (lateral) movements with surgery, with greater displacement of the inferior part of the rami (≥2 mm in 65% of the subjects). This torque of the ramus with surgery was stable 1 year postsurgery. Conclusions Three-dimensional assessment of skeletal changes with mandibular advancement surgery shows that nearly half of the patients have >2 mm change in chin position from splint removal to the 1-year follow-up, with approximately equal chances of anterior and posterior movement. Torque of the rami usually occurs with mandibular advancement surgery. PMID:20381760

  1. Early Neuropsychological Tests as Correlates of Productivity 1 Year after Traumatic Brain Injury: A Preliminary Matched Case-Control Study

    ERIC Educational Resources Information Center

    Ryu, Won Hyung A.; Cullen, Nora K.; Bayley, Mark T.

    2010-01-01

    This study explored the relative strength of five neuropsychological tests in correlating with productivity 1 year after traumatic brain injury (TBI). Six moderate-to-severe TBI patients who returned to work at 1-year post-injury were matched with six controls who were unemployed after 1 year based on age, severity of injury, and Functional…

  2. Metalloprotein-based MRI probes

    PubMed Central

    Matsumoto, Yuri; Jasanoff, Alan

    2013-01-01

    Metalloproteins have long been recognized as key determinants of endogenous contrast in magnetic resonance imaging (MRI) of biological subjects. More recently, both natural and engineered metalloproteins have been harnessed as biotechnological tools to probe gene expression, enzyme activity, and analyte concentrations by MRI. Metalloprotein MRI probes are paramagnetic and function by analogous mechanisms to conventional gadolinium or iron oxide-based MRI contrast agents. Compared with synthetic agents, metalloproteins typically offer worse sensitivity, but the possibilities of using protein engineering and targeted gene expression approaches in conjunction with metalloprotein contrast agents are powerful and sometimes definitive strengths. This review summarizes theoretical and practical aspects of metalloprotein-based contrast agents, and discusses progress in the exploitation of these proteins for molecular imaging applications. PMID:23376346

  3. Metalloprotein-based MRI probes.

    PubMed

    Matsumoto, Yuri; Jasanoff, Alan

    2013-04-17

    Metalloproteins have long been recognized as key determinants of endogenous contrast in magnetic resonance imaging (MRI) of biological subjects. More recently, both natural and engineered metalloproteins have been harnessed as biotechnological tools to probe gene expression, enzyme activity, and analyte concentrations by MRI. Metalloprotein MRI probes are paramagnetic and function by analogous mechanisms to conventional gadolinium or iron oxide-based MRI contrast agents. Compared with synthetic agents, metalloproteins typically offer worse sensitivity, but the possibilities of using protein engineering and targeted gene expression approaches in conjunction with metalloprotein contrast agents are powerful and sometimes definitive strengths. This review summarizes theoretical and practical aspects of metalloprotein-based contrast agents, and discusses progress in the exploitation of these proteins for molecular imaging applications.

  4. Bacterial diversity and structural changes of oyster shell during 1-year storage.

    PubMed

    Islam, Shah Md Asraful; Hong, Sun Joo; Cho, Kye Man; Math, Renukaradhya K; Heo, Jae Young; Lee, Young Han; Lee, Ki Sang; Yun, Han Dae

    2009-02-01

    We examined the biodiversity of bacteria associated with oyster-shell waste during a 1-year storage period using 16S ribosomal DNA analysis. Temperature variation and structural changes of oyster shell were observed during storage. Initial and final temperatures were at 16-17 degrees C, but a high temperature of about 60 degrees C was recorded after approximately 6 months of storage. The crystal structure and nanograin of the oyster shell surface were sharp and large in size initially and became gradually blunter and smaller over time. Phylogenetic analysis revealed that Firmicutes were dominant in the oyster-shell waste initially, during the high-temperature stage, and after 1 year of storage (making up >65% of the biodiversity at all three sampling times). Bacillus licheniformis was presumed as the predominate Firmicutes present. These bacteria are likely to have important roles in the biodegradation of oyster shell.

  5. Less is still more: maintenance of the very brief exposure effect 1 year later.

    PubMed

    Siegel, Paul; Warren, Richard

    2013-04-01

    This study tested the hypothesis that an immediate effect of exposure to masked phobic stimuli on avoidance of the corresponding feared object would be maintained 1 year later. Fifty-three spider-phobic participants were identified with a questionnaire and a Behavioral Avoidance Test (BAT) with a live tarantula. One week later, they were administered 1 of 3 types of exposure: very brief (25-ms, masked) or clearly visible (125-ms, unmasked) images of spiders, or very brief images of flowers. They engaged in the BAT again immediately thereafter. One year later, they returned for a follow-up BAT. The immediate effect of exposure to very brief spiders on reducing avoidance of the tarantula was still evident 1 year later. Endurance of an effect by masked stimuli of this duration has not been reported before. Potential theoretical implications are discussed. PMID:23527506

  6. Persistence of intestinal antibody response to heterologous rotavirus infection in a murine model beyond 1 year.

    PubMed Central

    Shaw, R D; Merchant, A A; Groene, W S; Cheng, E H

    1993-01-01

    We used an ELISPOT (enzyme-linked immunosorbent spot) assay to quantitate the long-term rotavirus-specific intestinal antibody response in a murine model. The frequency of murine intestinal antibody-secreting cells (ASCs) was followed for a period of 1 year after a single dose of rhesus rotavirus (10(6) PFU) was administered at 10 days of age. Some animals were boosted at that time with a second dose. One year after infection, virus-specific ASCs declined from acute-phase levels, but they were still present at significant levels (1.32 x 10(4) virus-specific ASCs per 10(6) intestinal mononuclear cells; approximately 17% of the previously reported response at 1 month after infection). A booster dose 1 year after the primary infection produced a 100% increase in virus-specific ASCs but did not restore the response to that of the primary infection. PMID:8381806

  7. A prospective study of the 1-year incidence of fibromyalgia after acute whiplash injury

    PubMed Central

    Ferrari, Robert

    2015-01-01

    Objective To measure the 1-year incidence of fibromyalgia in a cohort of acute whiplash-injured participants. Methods Consecutive acute patients with whiplash were assessed via the 2010 Modified American College of Rheumatology (ACR) criteria for fibromyalgia at 3 months, 6 months and 1 year postinjury. At each of these follow-up points, participants were also examined for recovery from whiplash injury. Results Of an initial 268 participants, data on recovery was available for 264 participants during the 1-year follow-up period. At the 3-month follow-up, 62% (167/268) of participants reported recovery from their whiplash injuries. At 6 months, 76% (203/268) reported recovery, and at 1 year 82% (216/264) reported recovery. At 3 and 6 months follow-up none of the participants met the 2010 Modified ACR Criteria for fibromyalgia, but fibromyalgia criteria were met for 2 (of 264) seen at the 1-year follow-up, yielding a 1-year incidence of 0.8% (95% CI 0.1% to 3.0%). Conclusions In the primary care setting, a significant proportion of patients with whiplash recover from whiplash injury at 1 year, and the incidence of fibromyalgia after acute whiplash injury is very low. The impression that fibromyalgia is common after whiplash injury may be due to the failure to exclude precollision fibromyalgia cases or due to referral bias of non-recovered patients. PMID:26509044

  8. Obesity negatively impacts aerobic capacity improvements both acutely and 1-year following cardiac rehabilitation.

    PubMed

    Martin, Billie-Jean; Aggarwal, Sandeep G; Stone, James A; Hauer, Trina; Austford, Leslie D; Knudtson, Merril; Arena, Ross

    2012-12-01

    Cardiac rehabilitation (CR) produces a host of health benefits related to modifiable cardiovascular risk factors. The purpose of the present investigation was to determine the influence of body weight, assessed through BMI, on acute and long-term improvements in aerobic capacity following completion of CR. Three thousand nine hundred and ninety seven subjects with coronary artery disease (CAD) participated in a 12-week multidisciplinary CR program. Subjects underwent an exercise test to determine peak estimated metabolic equivalents (eMETs) and BMI assessment at baseline, immediately following CR completion and at 1-year follow-up. Normal weight subjects at 1-year follow-up demonstrated the greatest improvement in aerobic fitness and best retention of those gains (gain in peak METs: 0.95 ± 1.1, P < 0.001). Although the improvement was significant (P < 0.001), subjects who were initially classified as obese had the lowest aerobic capacity and poorest retention in CR fitness gains at 1-year follow-up (gain in peak eMETs: 0.69 ± 1.2). Subjects initially classified as overweight by BMI had a peak eMET improvement that was also significantly better (P < 0.05) than obese subjects at 1-year follow-up (gain in peak eMETs: 0.82 ± 1.1). Significant fitness gains, one of the primary beneficial outcomes of CR, can be obtained by all subjects irrespective of BMI classification. However, obese patients have poorer baseline fitness and are more likely to "give back" fitness gains in the long term. Obese CAD patients may therefore benefit from additional interventions to enhance the positive adaptations facilitated by CR.

  9. Coupling of fMRI and NIRS measurements in the study of negative BOLD response to intermittent photic stimulation.

    PubMed

    Maggioni, E; Molteni, E; Arrigoni, F; Zucca, C; Reni, G; Triulzi, F M; Bianchi, A M

    2013-01-01

    Functional Magnetic Resonance Imaging (fMRI) in combination with Near Infrared Spectroscopy (NIRS) is finding widespread use in the analysis of brain function. While most of the studies deal with the detection of positive responses, here we focus on negative responses to visual stimulation. In a group fMRI study on Intermittent Photic Stimulation (IPS) we detected a sustained Negative BOLD Response (NBR) in the extrastriate visual cortex. To confirm and better characterize NBR, we repeated the same protocol during NIRS recordings. In this paper we show fMRI results and demonstrate the NBR on the basis of NIRS findings. PMID:24109953

  10. MRI and intraocular tamponade media.

    PubMed

    Manfrè, L; Fabbri, G; Avitabile, T; Biondi, P; Reibaldi, A; Pero, G

    1993-01-01

    Thirteen patients who underwent surgery for retinal detachment and injection of intraocular tamponade media (silicone oil, fluorosilicone oil, or perfluorocarbon liquid) underwent magnetic resonance imaging (MRI), using spin-echo T1- and T2-weighted images. The ophthalmic tamponade media showed different signal intensity, according to their chemical structure. Unlike ophthalmoscopy or ultrasonography, MRI showed no oil-related artefact, making possible recognition of recurrent retinal detachment.

  11. How hot is too hot? Live-trapped gray wolf rectal temperatures and 1-year survival

    USGS Publications Warehouse

    Barber-Meyer, Shannon M.; Mech, L. David

    2014-01-01

    The ability of physically restrained and anesthetized wolves to thermoregulate is lessened and could lead to reduced survival, yet no information is available about this subject. Therefore, we analyzed rectal temperatures related to survival 1 year post-capture from 173 adult (non-pup) gray wolves (Canis lupus) captured in modified foot-hold traps for radiocollaring during June–August, 1988–2011, in the Superior National Forest of northeastern Minnesota, USA. The maximum observed rectal temperature (“maxtemp,” ° F, ° C) in each wolf during capture (x = 104.0, 40.0; SD = 2.0, 1.1; min. = 95.9, 35.5; max. = 108, 42.2) was not a significant predictor of survival to 1 year post-capture. Although no weather or morphometric variable was a significant predictor of maxtemps, wolves initially anesthetized with ketamine–xylazine rather than telazol®–xylazine averaged higher maxtemps. This information does not fully address possible effects of high body temperatures related to live-capture and handling of wolves, but it does provide a useful waypoint for future assessments of this relationship and a reassurance to wildlife practitioners that the maxtemps observed in our study did not appear to affect 1-year survival.

  12. Major isoflavonoid contents of the 1-year-cultivated phytoestrogen-rich herb, Pueraria mirifica.

    PubMed

    Cherdshewasart, Wichai; Sriwatcharakul, Suttijit

    2007-10-01

    Pueraria mirifica is a tuberous plant enriched with active phytoestrogens. There is no established information about the factors influencing isoflavonoid storage in the tubers. We investigated the tuberous storage of the major isoflavonoids of 1-year-old plants. Four cultivars of P. mirifica were cultivated in the same field trial during the same period to establish a unique plant age and differentiation under the same environment and soil conditions. The tubers collected from the 1-year-old plants in the summer, rainy season and winter were submitted to an HPLC analysis with a gradient system comprising 0.1% acetic acid and acetonitrile. Five major isoflavonoids, puerarin, daidzin, genistin, daidzein and genistein, were adopted as standards. P. mirifica tubers of different cultivars collected in the same season exhibited significant differences in individual and total isoflavonoid contents, showing chemovariety. P. mirifica tubers of the same cultivar collected from different seasons also exhibited significant differences in individual and total isoflavonoid contents, showing the influence of season. In conclusion, the tuberous storage of major isoflavonoids in 1-year-cultivated plants was greatly diverse and was strongly influenced by the season and plant genetics.

  13. Predictors of Relapse after Inpatient Opioid Detoxification during 1-Year Follow-Up

    PubMed Central

    2016-01-01

    Introduction. Relapse rate after opioid detoxification is very high. We studied the possibility that predetoxification patient characteristics might predict relapse at follow-up and thus conducted this 1-year follow-up study to assess the predictors of relapse after inpatient opioid detoxification. Materials and Methods. We conducted this study in our tertiary care institute in India over two-year time period (1 Jan 2014 to 31 Dec 2015). Out of 581 patients admitted, 466 patients were considered for study. Results and Discussion. No significant difference was found between relapsed and nonrelapsed patients regarding sociodemographic profile; however substance abuse pattern and forensic history showed significant differences. Relapsed patients abused greater amount and used injections more commonly, as compared to nonrelapsed group. Longer duration of abuse was also a significant risk factor. Patients with past attempt of opioid detoxification and family history (parental or first degree) of alcohol abuse had decreased possibility of maintaining remission during 1-year follow-up. Relapsed patients were found to abuse their spouse or parents. Conclusion. Our study compared profiles of relapsed and nonrelapsed patients after inpatient detoxification and concluded predictors of relapse during 1-year follow-up period. Early identification of predictors of relapse and hence high risk patients might be helpful in designing more effective and focused treatment plan. PMID:27722007

  14. Blastocystis surface antigen is stable in chemically preserved stool samples for at least 1 year.

    PubMed

    Gould, Rick; Boorom, Kenneth

    2013-07-01

    Blastocystis spp. refer to a group of prevalent enteric protists found in humans and animals. Detection of Blastocystis spp. in fecal samples is often performed by clinicians with direct microscopy, which provides low sensitivity, or with culture and polymerase chain reaction testing, a method which is problematic when used with formalin-preserved stool samples. Prior study of Blastocystis and other enteric protists suggests that immunofluorescence antibody (IFA) stain could provide sensitivity and compatibility with formalin, but no information is available on the longevity of Blastocystis sp.'s surface antigens in formalin. We collected fecal samples from animals at a country fair held in the summer of 2009 in Oregon, USA. Samples were tested for the presence of Blastocystis infection using an IFA stain shortly after collection, and again after 1 year, with samples stored refrigerated at 4-8 °C. Most samples collected from steer, pigs, and goats were found to be Blastocystis positive. All fecal samples that were Blastocystis positive initially remained positive after 1 year. Blastocystis-negative samples remained negative. Minimal degradation was observed in stained slides. Blastocystis surface antigens detected by a polyclonal stain remained stable in formalin for a period of at least 1 year.

  15. Accumulate Repeat Accumulate Coded Modulation

    NASA Technical Reports Server (NTRS)

    Abbasfar, Aliazam; Divsalar, Dariush; Yao, Kung

    2004-01-01

    In this paper we propose an innovative coded modulation scheme called 'Accumulate Repeat Accumulate Coded Modulation' (ARA coded modulation). This class of codes can be viewed as serial turbo-like codes, or as a subclass of Low Density Parity Check (LDPC) codes that are combined with high level modulation. Thus at the decoder belief propagation can be used for iterative decoding of ARA coded modulation on a graph, provided a demapper transforms the received in-phase and quadrature samples to reliability of the bits.

  16. Hybrid-SPRITE MRI.

    PubMed

    Xiao, Dan; Balcom, Bruce J

    2013-10-01

    In a FID based frequency encoding MRI experiment the central part of k-space is not generally accessible due to the probe dead time. This portion of k-space is however crucial for image reconstruction. SPRITE (Single Point Ramped Imaging with T1 Enhancement), SPI with a linearly ramped phase encode gradient, has been employed to image short relaxation time systems for many years with great success. It is a robust imaging method in significant measure because it provides acquisition of high quality k-space origin data. We propose a new sampling scheme, termed hybrid-SPRITE, combining phase and frequency encoding to ensure high quality images with reduced acquisition times, reduced gradient duty cycle and increased sensitivity. In hybrid-SPRITE, numerous time domain points are collected to assist image reconstruction. An Inverse Non-uniform Discrete Fourier Transform (INDFT) is employed in 1D applications. A pseudo-polar grid is exploited in 2D hybrid-SPRITE for rapid and accurate image reconstruction. PMID:23916990

  17. Crowding by a repeating pattern.

    PubMed

    Rosen, Sarah; Pelli, Denis G

    2015-01-01

    Theinability to recognize a peripheral target among flankers is called crowding. For a foveal target, crowding can be distinguished from overlap masking by its sparing of detection, linear scaling with eccentricity, and invariance with target size.Crowding depends on the proximity and similarity of the flankers to the target. Flankers that are far from or dissimilar to the target do not crowd it. On a gray page, text whose neighboring letters have different colors, alternately black and white, has enough dissimilarity that it might escape crowding. Since reading speed is normally limited by crowding, escape from crowding should allow faster reading. Yet reading speed is unchanged (Chung & Mansfield, 2009). Why? A recent vernier study found that using alternating-color flankers produces strong crowding (Manassi, Sayim, & Herzog, 2012). Might that effect occur with letters and reading? Critical spacing is the minimum center-to-center target-flanker spacing needed to correctly identify the target. We measure it for a target letter surrounded by several equidistant flanker letters of the same polarity, opposite polarity, or mixed polarity: alternately white and black. We find strong crowding in the alternating condition, even though each flanker letter is beyond its own critical spacing (as measured in a separate condition). Thus a periodic repeating pattern can produce crowding even when the individual elements do not. Further, in all conditions we find that, once a periodic pattern repeats (two cycles), further repetition does not affect critical spacing of the innermost flanker.

  18. Repeated Reading. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2014

    2014-01-01

    "Repeated reading" is an academic practice that aims to increase oral reading fluency. "Repeated reading" can be used with students who have developed initial word reading skills but demonstrate inadequate reading fluency for their grade level. During "repeated reading," a student sits in a quiet location with a…

  19. 47 CFR 22.1015 - Repeater operation.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Repeater operation. 22.1015 Section 22.1015... Offshore Radiotelephone Service § 22.1015 Repeater operation. Offshore central stations may be used as repeater stations provided that the licensee is able to maintain control of the station, and in...

  20. Changes in cerebrospinal fluid flow assessed using intraoperative MRI during posterior fossa decompression for Chiari malformation.

    PubMed

    Bond, Aaron E; Jane, John A; Liu, Kenneth C; Oldfield, Edward H

    2015-05-01

    OBJECT The authors completed a prospective, institutional review board-approved study using intraoperative MRI (iMRI) in patients undergoing posterior fossa decompression (PFD) for Chiari I malformation. The purpose of the study was to examine the utility of iMRI in determining when an adequate decompression had been performed. METHODS Patients with symptomatic Chiari I malformations with imaging findings of obstruction of the CSF space at the foramen magnum, with or without syringomyelia, were considered candidates for surgery. All patients underwent complete T1, T2, and cine MRI studies in the supine position preoperatively as a baseline. After the patient was placed prone with the neck flexed in position for surgery, iMRI was performed. The patient then underwent a bone decompression of the foramen magnum and arch of C-1, and the MRI was repeated. If obstruction was still present, then in a stepwise fashion the patient underwent dural splitting, duraplasty, and coagulation of the tonsils, with an iMRI study performed after each step guiding the decision to proceed further. RESULTS Eighteen patients underwent PFD for Chiari I malformations between November 2011 and February 2013; 15 prone preincision iMRIs were performed. Fourteen of these patients (93%) demonstrated significant improvement of CSF flow through the foramen magnum dorsal to the tonsils with positioning only. This improvement was so notable that changes in CSF flow as a result of the bone decompression were difficult to discern. CONCLUSIONS The authors observed significant CSF flow changes when simply positioning the patient for surgery. These results put into question intraoperative flow assessments that suggest adequate decompression by PFD, whether by iMRI or intraoperative ultrasound. The use of intraoperative imaging during PFD for Chiari I malformation, whether by ultrasound or iMRI, is limited by CSF flow dynamics across the foramen magnum that change significantly when the patient is

  1. Fractures in children younger than age 1 year: importance of collaboration with child protection services.

    PubMed

    Banaszkiewicz, Paul A; Scotland, Thomas R; Myerscough, Elizabeth J

    2002-01-01

    The medical records of all children less than 1 year of age presenting to the Accident and Emergency Department over a 5-year period (1995-1999) with a fracture were retrospectively reviewed for possible abuse. Seventy-four children presented with fractures during the study period, with a mean age at presentation of 5 months (range 2 weeks to 1 year). Of these children, 46 had skull fractures and 28 had long bone fractures. Children were classified into one of seven categories: definite abuse, likely abuse, suspicious, likely accident, definite accident, neglect, or unknown cause. A three-tier system of grading for possible abuse was then used to analyze variance. The first tier consisted of the initial assessment by staff clinicians, the second retrospectively by an orthopaedic registrar, and the third retrospectively by a designated doctor in child protection (consultant pediatrician), all using the same information from the case notes. The use of the three-tier system of grading demonstrated a variance in the diagnosis of nonaccidental injury. The possibility of abuse was underestimated at the time of the original injury in over a quarter of cases (28.4%) when compared with the assessment by the consultant pediatrician. In 34 children (46%), there was no written documentation that nonaccidental injury was ever considered. While management depends on local guidelines and arrangements, the authors would advise that all children under 1 year of age with a fracture should be admitted to the hospital and referred to a pediatrician for child protection assessment. PMID:12409899

  2. Corneal Crosslinking for Keratoconus in Iranian Patients: Outcomes at 1 year following treatment

    PubMed Central

    Saffarian, Ladan; Khakshoor, Hamid; Zarei-Ghanavati, Mehran; Esmaily, Habibollah

    2010-01-01

    Aim and Design: A retrospective, nonrandomized, single-center clinical study was designed to evaluate the outcomes of corneal collagen crosslinking (CXL) for progressive keratoconus in Iranian patients 12 months after CXL. Settings: This study was carried out at Navid Didegan Eye Center, a private clinic, Mashhad, Iran. Materials and Methods: Ninety-two eyes of 53 subjects with progressive keratoconus were evaluated in this study. All eyes completed 1-year follow-up. The outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), sphere and cylinder refraction, keratometry, and corneal thickness. Comparison of baseline and 1-year postoperative data is reported in this study. The Wilcoxon signed-ranked and Student’s t-tests were used for statistical analyses. P < 0.05 was statistically significant. Results: The mean age was 21.5 ± 3.4 years (range, 16 -30 years). Thirty-one (58.5%) of the subjects were men and 22 (41.5%) were women. Mean baseline UCVA and BSCVA were 0.61 ± 0.31 and 0.06 ± 0.12 logarithm of minimal angle of resolution (logMAR), respectively. One year postoperatively UCVA was 0.31 ± 0.25 logMAR and BSCVA was 0.0 ± 0.01 logMAR. UCVA and BSCVA were statistically higher postoperatively (P < 0.001, both parameters). The mean astigmatism decreased by 0.78 ± 1.49 diopter (D) with significant variation during the follow-up period (P < 0.001). Mean baseline simulated keratometry (SIM K) was 46.94 ± 2.37 D and decreased to 46.0 ± 2.33 D on year postoperatively (P < 0.001). Conclusion: Corneal CXL seems to be efficient in stabilization of progressive keratoconus progression in Iranian patients at 1 year of followup. PMID:21180440

  3. Necessity and Opportunity: the 1-Year Master's ABA Program at Auburn University.

    PubMed

    Johnston, James M

    2016-05-01

    The Auburn University Master of Science program in Applied Behavior Analysis was designed to accommodate not only the requirements of the Behavior Analyst Certification Board for approved course sequences and practicum training, but unavoidable limitations in faculty and other resources. These limitations were incompatible with the more traditional 2-year curriculum model, so a 1-year program was designed that met the necessary conditions. This article describes the resulting academic and practicum curriculum, the key funding mechanisms that allowed the program to develop, and the opportunities and benefits that this model afforded. PMID:27606193

  4. Vitamin D Plasma Levels and In-Hospital and 1-Year Outcomes in Acute Coronary Syndromes

    PubMed Central

    De Metrio, Monica; Milazzo, Valentina; Rubino, Mara; Cabiati, Angelo; Moltrasio, Marco; Marana, Ivana; Campodonico, Jeness; Cosentino, Nicola; Veglia, Fabrizio; Bonomi, Alice; Camera, Marina; Tremoli, Elena; Marenzi, Giancarlo

    2015-01-01

    Abstract Deficiency in 25-hydroxyvitamin D (25[OH]D), the main circulating form of vitamin D in blood, could be involved in the pathogenesis of acute coronary syndromes (ACS). To date, however, the possible prognostic relevance of 25 (OH)D deficiency in ACS patients remains poorly defined. The purpose of this prospective study was to assess the association between 25 (OH)D levels, at hospital admission, with in-hospital and 1-year morbidity and mortality in an unselected cohort of ACS patients. We measured 25 (OH)D in 814 ACS patients at hospital presentation. Vitamin D serum levels >30 ng/mL were considered as normal; levels between 29 and 21 ng/mL were classified as insufficiency, and levels < 20 ng/mL as deficiency. In-hospital and 1-year outcomes were evaluated according to 25 (OH)D level quartiles, using the lowest quartile as a reference. Ninety-three (11%) patients had normal 25 (OH)D levels, whereas 155 (19%) and 566 (70%) had vitamin D insufficiency and deficiency, respectively. The median 25 (OH)D level was similar in ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI) patients (14.1 [IQR 9.0–21.9] ng/mL and 14.05 [IQR 9.1–22.05] ng/mL, respectively; P = .88). The lowest quartile of 25 (OH)D was associated with a higher risk for several in-hospital complications, including mortality. At a median follow-up of 366 (IQR 364–379) days, the lowest quartile of 25 (OH)D, after adjustment for the main confounding factors, remained significantly associated to 1-year mortality (P < .01). Similar results were obtained when STEMI and NSTEMI patients were considered separately. In ACS patients, severe vitamin D deficiency is independently associated with poor in-hospital and 1-year outcomes. Whether low vitamin D levels represent a risk marker or a risk factor in ACS remains to be elucidated. PMID:25984675

  5. Institutional factors influencing regional differences in the 1-year survival of dialysis patients.

    PubMed

    Ogata, Satoshi; Nishi, Shinichi; Wakai, Kenji; Hanafusa, Norio; Iseki, Kunitoshi; Tsubakihara, Yoshiharu; Masakane, Ikuto

    2015-10-01

    There are regional differences in the survival of incident dialysis patients, but few studies have investigated the reasons. We assessed the effect of institutional factors on factors on survival (by both cross-sectional assessment and after a 1-year investigation) in a cohort of the Japanese Society for Dialysis Therapy (JSDT). We investigated 20 institutional factors from 3958 dialysis institution data of the 47 prefectures in Japan in 2005 and the JSDT database of 102,011 patients who commenced dialysis during 2004-2006. Univariate regression analysis between 20 factors and 1-year survival rate, Kaplan-Meier method, log-rank test, and Cox's proportional hazard model between the upper 24 and the lower 23 prefectures of the significant factors were carried out. The age-adjusted 1-year survival rate was 0.832 ± 0.027. Deaths occurred in 15.0% in 24 upper survival prefectures and 18.7% in 23 lower survival prefectures (P < 0.0001, unadjusted hazard ratio [HR] of death in lower survival prefectures: 1.26, 95% confidence interval [CI]: 1.17-1.40). A total of five factors among males were significantly correlated with 1-year survival according to the univariate regression analysis. Among them, three factors (night-time center/total dialysis center ratio [males: P < 0.0001, age, genders, and presence of diabetes adjusted HR: 0.88, 95% CI: 0.81-0.93], number of full-time dialysis nurses [males: P = 0.0427, 0.94, 0.87-1.00], number of full-time dialysis dietitians [males: P = 0.0084, 0.92, 0.85-0.98], respectively) were significant in Kaplan-Meier analysis, log-rank test, and the Cox's model. Institutional factors were closely related to the survival of incident dialysis patients, and regional differences in the survival may be explained, at least partly, by these factors.

  6. MRI Abnormalities Are Common In Little League Player’s Elbows

    PubMed Central

    Pennock, Andrew T.; Roocroft, Joanna Helena; Bastrom, Tracey P.; Kruk, Peter

    2016-01-01

    Objectives: Youth baseball is extremely popular, but it has been associated with elbow pain and pathology. The purpose of this study was to examine pre- and post-season Magnetic Resonance Imaging (MRI) changes in Little League baseball players and correlate these findings with the players’ throwing history and physical exams. Methods: A prospective study of Little League players age 10 -13 years was performed. Players were recruited prior to the start of the season and underwent bilateral elbow MRI. All players underwent a physical exam and responded to a questionnaire addressing their playing history and arm pain. At the end of the season, the players underwent repeat physical exam and MRI of their throwing arm. MRIs were read by two blinded radiologists. During the season, player statistics including innings played and pitch counts were recorded. Physical exam findings and players statistics were compared between subjects with and without MRI changes utilizing chi-square and ANOVA techniques. Results: Twenty-six players were enrolled. On pre-season MRI, nine players (35%) had 12 positive MRI findings; edema of the medial epicondyle (ME) apophysis (7), fragmentation of ME (2), and edema of the sublime tubercle (3). The two factors associated with a positive MRI were year round play (47% vs 11%, p<0.01) and working with a private coach (71% vs 21%, p=0.02). A history of pain was also associated with year round play and a private coach (p<0.05). Loss of internal rotation was associated with an abnormal MRI (p = 0.04). Post-season, 25 players returned for follow-up. Ten players (40%) had an abnormal MRI of which 8 (32%) had new/worsening findings. There was a significant difference in distal humeral physeal width measured pre- to post-season (1.54 mm vs 2.31 mm p<0.001). There was a significant decrease in internal rotation measured pre- to post-season of the shoulder in all patients regardless of MRI findings (62° vs 43°, p=0.001). Pitch counts, player position

  7. Estimating Motion From MRI Data

    PubMed Central

    OZTURK, CENGIZHAN; DERBYSHIRE, J. ANDREW; MCVEIGH, ELLIOT R.

    2007-01-01

    Invited Paper Magnetic resonance imaging (MRI) is an ideal imaging modality to measure blood flow and tissue motion. It provides excellent contrast between soft tissues, and images can be acquired at positions and orientations freely defined by the user. From a temporal sequence of MR images, boundaries and edges of tissues can be tracked by image processing techniques. Additionally, MRI permits the source of the image signal to be manipulated. For example, temporary magnetic tags displaying a pattern of variable brightness may be placed in the object using MR saturation techniques, giving the user a known pattern to detect for motion tracking. The MRI signal is a modulated complex quantity, being derived from a rotating magnetic field in the form of an induced current. Well-defined patterns can also be introduced into the phase of the magnetization, and could be thought of as generalized tags. If the phase of each pixel is preserved during image reconstruction, relative phase shifts can be used to directly encode displacement, velocity and acceleration. New methods for modeling motion fields from MRI have now found application in cardiovascular and other soft tissue imaging. In this review, we shall describe the methods used for encoding, imaging, and modeling motion fields with MRI. PMID:18958181

  8. fMRI Sequential-Finger Movement Activation Differentiating Good and Poor Writers

    PubMed Central

    Richards, Todd L.; Berninger, Virginia W.; Stock, Pat; Altemeier, Leah; Trivedi, Pamala; Maravilla, Ken

    2009-01-01

    Good and poor fifth-grade writers differed, after controlling for multiple comparisons, in 42 brain regions on group maps and then individual brain analyses for fMRI contrast between tapping adjacent fingers sequentially and same finger repeatedly. Of these, 11 regions were correlated with both handwriting and spelling (transcription). Gender differences on the fMRI contrast, with girls more activated, occurred only in left superior parietal, which was correlated with handwriting and spelling. Significance of serial-organization of fingers for handwriting and spelling is discussed. PMID:19358006

  9. Induction of Maturogenesis by Partial Pulpotomy: 1 Year Follow-Up

    PubMed Central

    Bacaksiz, A.; Alaçam, A.

    2013-01-01

    In cariously exposed immature permanent teeth, the treatment choice is controversial in pediatric dentistry. Radical root canal treatment usually appears to be the solution for these teeth. Even partial pulpotomy is a vital treatment for traumatically exposed immature permanent teeth; extending the borders of indication towards cariously exposed immature permanent teeth with reversible pulpitis may abolish the necessity of pulpectomy. This article describes the partial pulpotomy of a cariously affected immature permanent teeth and the follow-up for 1 year. A healthy 11-year-old male patient was referred to Gazi University Faculty of Dentistry Department of Pediatric Dentistry. The patient had reversible pulpitis symptoms on teeth numbered 45. At radiographic examination, immature apex and deep caries lesion were observed and partial pulpotomy was performed by using calcium hydroxide to maintain vitality of the pulp and allow continued development of root dentin expecting the root will attain full maturity. Clinical and radiographic follow-up demonstrated a vital pulp besides not only closure of the apex (apexogenesis), but also physiologic root development (maturogenesis) after 1 year. Partial pulpotomy is an optional treatment for cariously exposed immature permanent teeth for preserving vitality and physiological root development. PMID:24324899

  10. Gestational hormone profiles predict human maternal behavior at 1-year postpartum.

    PubMed

    Glynn, Laura M; Davis, Elysia Poggi; Sandman, Curt A; Goldberg, Wendy A

    2016-09-01

    In many non-human species, including primates, gestational reproductive hormones play an essential role in the onset of maternal motivation and behaviors. We investigated the associations between prepartum estradiol and progesterone and maternal behavior at 1-year postpartum in 177 women. Blood was obtained at five gestational time points and an index of quality of maternal care was determined using a well-validated mother-child interaction protocol. Women who exhibited higher quality maternal care at 1-year postpartum were characterized by unique gestational profiles of estradiol, progesterone and the estrogen to progesterone ratio; specifically by slower accelerations and levels of these hormone trajectories beginning in midgestation. Further, it appeared that both fetal sex and parity moderated these findings, with first time mothers and mothers of females showing stronger associations. In sum, these data document persisting associations between prepartum hormone profiles and human maternal behavior. More broadly, these findings add to the growing literature highlighting the perinatal period as one of critical neurodevelopment in the lifespan of the human female. PMID:27427279

  11. Systemic ketoconazole in tinea versicolor: a double-blind evaluation and 1-year follow-up.

    PubMed

    Savin, R C

    1984-05-01

    A 4-week, double-blind comparison of ketoconazole and placebo was conducted in sixty-six patients with tinea versicolor. Two hundred milligrams of ketoconazole in a daily oral dose was effective in producing a clinical and mycologic cure: lesions in thirty-three of thirty-four patients on active drug were completely healed (97%), and one patient had a mild residual effect. Only three patients on placebo were considered to have responded, and none experienced complete healing. Potassium hydroxide (KOH) examinations were negative in all but one of the patients given ketoconazole. All patients receiving ketoconazole who were KOH-negative at week 4 also showed negative results when reexamined 8 weeks later. Patients who did not respond (virtually all of the patients given placebo) were subsequently treated with a topical imidazole lotion. Safety evaluation, including blood chemistry tests and a comprehensive liver function battery, showed no differences between the ketoconazole and placebo groups. Ketoconazole was well tolerated and produced no significant adverse effects. Follow-up after 1 year revealed that 64% of patients given ketoconazole were still clear, whereas only 11% of patients who received placebo (later treated with imidazole topically) were clear after 1 year.

  12. Parental spanking of 1-year-old children and subsequent child protective services involvement.

    PubMed

    Lee, Shawna J; Grogan-Kaylor, Andrew; Berger, Lawrence M

    2014-05-01

    The majority of U.S. parents spank their children, often beginning when their children are very young. We examined families (N=2,788) who participated in a longitudinal community-based study of new births in urban areas. Prospective analyses examined whether spanking by the child's mother, father, or mother's current partner when the child was 1-year-old was associated with household CPS involvement between age 1 and age 5. Results indicated that 30% of 1-year-olds were spanked at least once in the past month. Spanking at age 1 was associated with increased odds of subsequent CPS involvement (adjusted odds ratio=1.36, 95% CI [1.08, 1.71], p<.01). When compared to non-spanked children, there was a 33% greater probability of subsequent CPS involvement for children who were spanked at age 1. Given the undesirable consequences of spanking children and a lack of empirical evidence to suggest positive effects of physical punishment, professionals who work with families should counsel parents not to spank infants and toddlers. For optimal benefits, efforts to educate parents regarding alternative forms of discipline should begin during the child's first year of life.

  13. Parental spanking of 1-year-old children and subsequent child protective services involvement✩

    PubMed Central

    Lee, Shawna J.; Grogan-Kaylor, Andrew; Berger, Lawrence M.

    2015-01-01

    The majority of U.S. parents spank their children, often beginning when their children are very young. We examined families (N=2,788) who participated in a longitudinal community-based study of new births in urban areas. Prospective analyses examined whether spanking by the child's mother, father, or mother's current partner when the child was 1-year-old was associated with household CPS involvement between age 1 and age 5. Results indicated that 30% of 1-year-olds were spanked at least once in the past month. Spanking at age 1 was associated with increased odds of subsequent CPS involvement (adjusted odds ratio=1.36, 95% CI [1.08, 1.71], p<.01). When compared to non-spanked children, there was a 33% greater probability of subsequent CPS involvement for children who were spanked at age 1. Given the undesirable consequences of spanking children and a lack of empirical evidence to suggest positive effects of physical punishment, professionals who work with families should counsel parents not to spank infants and toddlers. For optimal benefits, efforts to educate parents regarding alternative forms of discipline should begin during the child's first year of life. PMID:24602690

  14. Residual skin damage in rats 1 year after exposure to x rays or accelerated heavy ions

    SciTech Connect

    Leith, J.T.; McDonald, M.; Howard, J.

    1982-01-01

    In conjunction with a study on the biological effects of accelerated heavy ions on rat spinal cord, we were able to assess the residual skin damage remaining 1 year postirradiation. In this study, rats were irradiated with 230-kVp fractionated doses of either X rays, carbon ions, or neon ions. Four radiation fractions were given at daily intervals. For the carbon and neon ion exposures, rats were irradiated in both the plateau and spread Bragg peak (4 cm) regions of ionization. Comparing doses that produced complete epilation with a slight suggestion of a residual radiation scar, it was found that the relative biological effectivesness (RBE) values 1 year postirradiation for the four fraction irradiations were: carbon ions (plateau ionization region), 1.06; carbon ions (spread Bragg peak ionization region), 1.88; neon ions (plateau region of ionization), 1.55; and neon ions (spread Bragg peak ionization region), 2.26. RBE values for production of paralysis after spinal cord irradiation (using the same X-ray total dose levels for comparison purposes) were in all cases higher than the RBE values obtained from assessment of residual skin injury.

  15. Worksite Opportunities for Wellness (WOW): Effects on cardiovascular disease risk factors after 1 year

    PubMed Central

    Racette, Susan B.; Deusinger, Susan S.; Inman, Cindi L.; Burlis, Tamara L.; Highstein, Gabrielle R.; Buskirk, Trent D.; Steger-May, Karen; Peterson, Linda R.

    2015-01-01

    Objective To evaluate the effectiveness of a worksite health promotion program on improving cardiovascular disease risk factors. Methods In St Louis, Missouri from 2005 to 2006, 151 employees (134 F, 17 M, 81% overweight/obese) participated in a cohort-randomized trial comparing assessments + intervention (worksite A) with assessments only (worksite B) for 1 year. All participants received personal health reports containing their assessment results. The intervention was designed to promote physical activity and favorable dietary patterns using pedometers, healthy snack cart, WeightWatchers® meetings, group exercise classes, seminars, team competitions, and participation rewards. Outcomes included BMI, body composition, blood pressure, fitness, lipids, and Framingham 10-year coronary heart disease risk. Results 123 participants, aged 45 ± 9 yr, with BMI 32.9 ± 8.8 kg/m2 completed 1 year. Improvements (P ≤ 0.05) were observed at both worksites for fitness, blood pressure, and total-, HDL-, and LDL-cholesterol. Additional improvements occurred at worksite A in BMI, fat mass, Framingham risk score, and prevalence of the metabolic syndrome; only the changes in BMI and fat mass were different between worksites. Conclusion A multi-faceted worksite intervention promoted favorable changes in cardiovascular disease risk factors, but many of the improvements were achieved with worksite health assessments and personalized health reports in the absence of an intervention. PMID:19576927

  16. BDNF mediates improvements in executive function following a 1-year exercise intervention

    PubMed Central

    Leckie, Regina L.; Oberlin, Lauren E.; Voss, Michelle W.; Prakash, Ruchika S.; Szabo-Reed, Amanda; Chaddock-Heyman, Laura; Phillips, Siobhan M.; Gothe, Neha P.; Mailey, Emily; Vieira-Potter, Victoria J.; Martin, Stephen A.; Pence, Brandt D.; Lin, Mingkuan; Parasuraman, Raja; Greenwood, Pamela M.; Fryxell, Karl J.; Woods, Jeffrey A.; McAuley, Edward; Kramer, Arthur F.; Erickson, Kirk I.

    2014-01-01

    Executive function declines with age, but engaging in aerobic exercise may attenuate decline. One mechanism by which aerobic exercise may preserve executive function is through the up-regulation of brain-derived neurotropic factor (BDNF), which also declines with age. The present study examined BDNF as a mediator of the effects of a 1-year walking intervention on executive function in 90 older adults (mean age = 66.82). Participants were randomized to a stretching and toning control group or a moderate intensity walking intervention group. BDNF serum levels and performance on a task-switching paradigm were collected at baseline and follow-up. We found that age moderated the effect of intervention group on changes in BDNF levels, with those in the highest age quartile showing the greatest increase in BDNF after 1-year of moderate intensity walking exercise (p = 0.036). The mediation analyses revealed that BDNF mediated the effect of the intervention on task-switch accuracy, but did so as a function of age, such that exercise-induced changes in BDNF mediated the effect of exercise on task-switch performance only for individuals over the age of 71. These results demonstrate that both age and BDNF serum levels are important factors to consider when investigating the mechanisms by which exercise interventions influence cognitive outcomes, particularly in elderly populations. PMID:25566019

  17. Phase Fluctuations at Goldstone Derived from 1-Year Site Testing Interferometer Data

    NASA Technical Reports Server (NTRS)

    Nessel, James A.; Acosta, Roberto J.; Morabito, David D.

    2009-01-01

    A two-element site test interferometer has been deployed at the NASA Deep Space Network (DSN) tracking complex in Goldstone, California, since May 2007. The interferometer system consists of two offset-fed 1.2 m parabolic reflectors which monitor atmospheric-induced amplitude and phase fluctuations on an unmodulated beacon signal (20.199 GHz) broadcast from a geostationary satellite (Anik F2). The geometry of the satellite and the ground-based infrastructure imposes a 48.5 elevation angle with a separation distance of 256 m along an east-west baseline. The interferometer has been recording phase fluctuation data, to date, for 1 yr with an overall system availability of 95 percent. In this paper, we provide the cumulative distribution functions (CDFs) for 1 year of recorded data, including phase rms, spatial structure function exponent, and surface meteorological measurements: surface wind speed, relative humidity, temperature, barometric pressure, and rain rate. Correlation between surface measurements, phase rms, and amplitude rms at different time scales are discussed. For 1 year, phase fluctuations at the DSN site in Goldstone, are better than 23 for 90 percent of the time (at 48.5 elevation). This data will be used to determine the suitability of the Goldstone site as a location for the Next Generation Deep Space Network.

  18. A Semiparametric Bayesian Model for Repeatedly Repeated Binary Outcomes

    PubMed Central

    Quintana, Fernando A.; Müller, Peter; Rosner, Gary L.; Relling, Mary V.

    2009-01-01

    Summary We discuss the analysis of data from single nucleotide polymorphism (SNP) arrays comparing tumor and normal tissues. The data consist of sequences of indicators for loss of heterozygosity (LOH) and involve three nested levels of repetition: chromosomes for a given patient, regions within chromosomes, and SNPs nested within regions. We propose to analyze these data using a semiparametric model for multi-level repeated binary data. At the top level of the hierarchy we assume a sampling model for the observed binary LOH sequences that arises from a partial exchangeability argument. This implies a mixture of Markov chains model. The mixture is defined with respect to the Markov transition probabilities. We assume a nonparametric prior for the random mixing measure. The resulting model takes the form of a semiparametric random effects model with the matrix of transition probabilities being the random effects. The model includes appropriate dependence assumptions for the two remaining levels of the hierarchy, i.e., for regions within chromosomes and for chromosomes within patient. We use the model to identify regions of increased LOH in a dataset coming from a study of treatment-related leukemia in children with an initial cancer diagnostic. The model successfully identifies the desired regions and performs well compared to other available alternatives. PMID:19746193

  19. MRI artefacts after Bonebridge implantation.

    PubMed

    Steinmetz, C; Mader, I; Arndt, S; Aschendorff, A; Laszig, R; Hassepass, F

    2014-07-01

    The new transcutaneous bone conduction implant (BCI) Bonebridge (BB, MED-EL) allows the skin to remain intact and therefore overcomes some issues related to percutaneous systems, such as skin reaction around the external screw and cosmetic complaints. According to manufacturer, BB is MRI conditional up to 1,5 Tesla (T). The artefact of the neurocranium after BB implantation is extensive as shown in the present report. This has to be taken into account when patients suffering conductive, mixed or single-sided hearing loss with candidacy for a BCI are counselled. In patients with comorbid intracranial tumour or other diseases of the brain that require imaging control scans with MRI percutaneous, BCI should be the implant of choice considering the very small artefact of the percutaneous screw in MRI.

  20. Signal intensity, clinical activity and cross-sectional areas on MRI scans in thyroid eye disease.

    PubMed

    Mayer, E J; Fox, D L; Herdman, G; Hsuan, J; Kabala, J; Goddard, P; Potts, M J; Lee, R W J

    2005-10-01

    The signal intensity from inflamed extra-ocular muscles on short tau inversion recovery (STIR)-sequence magnetic resonance imaging (MRI) is known to correlate with clinical scores of thyroid eye disease (TED) severity. Twenty-one patients who had undergone repeated MRI scanning for TED were studied retrospectively. Signal intensity of extra-ocular muscles (from STIR-sequence MRI) and cross-sectional area (from STIR and T1 MRI) were correlated with Mourits' clinical activity score (CAS). The area of highest signal intensity within the most inflamed extra-ocular muscle, and the average cross-sectional signal intensity of the most inflamed extra-ocular muscle reliably correlated with CAS, and this was maintained as disease activity changed over time. In contrast, isolated measures of muscle cross-sectional area did not correlate with CAS. The extra-ocular muscle cross-sectional area calculated from STIR-sequence MR images was greater than that measured on T1 images. This suggests that muscle area from STIR-sequence MRI may also detect peri-muscular inflammation. We conclude that the peak signal intensity from the most inflamed extra-ocular muscle remains the most reliable correlate of clinical disease activity obtained from these images. STIR-sequence MRI scans provide a number of useful measures of disease activity in TED.

  1. Transient CNS responses to repeated binge ethanol treatment

    PubMed Central

    Zahr, Natalie M; Rohlfing, Torsten; Mayer, Dirk; Luong, Richard; Sullivan, Edith V; Pfefferbaum, Adolf

    2016-01-01

    Adaptive changes occur in response to repeated exposure to drugs. Although ethanol (EtOH) is known to induce pharmacokinetic tolerance, the effects of EtOH on in vivo, magnetic resonance (MR)-detectable brain measures across repeated exposures have not previously been reported. Of 28 rats weighing 341±22g at baseline, 15 were assigned to the EtOH group and 13 to the control (Ctrl) group. EtOH animals were exposed to 5 cycles of 4-days of EtOH treatment followed by 10 days of recovery. Rats in both groups had structural MR imaging (MRI) scans and whole brain MR spectroscopy (MRS) at baseline, immediately following each binge period, and after each recovery period (total=11 MR scans per rat). Average blood alcohol levels (BALs) across each of the 5, 4-day binge periods were 298, 300, 301, 312, 318 mg/dL. Cerebrospinal fluid (CSF) volumes of the lateral ventricles and cisterns showed enlargement with each binge EtOH exposure but recovery with each abstinence period. Similarly, changes to MRS metabolites were transient: levels of N-acetyl aspartate (NAA) and total creatine (tCr) decreased, while those of choline-containing compounds (Cho) and glutamate/glutamine (Glx) increased with each binge EtOH exposure cycle, but also recovered during each abstinence period. The directionality of changes in response to EtOH were in expected directions based on previous, single-binge EtOH exposure experiments, but the current results do not provide support for accruing pathology with repeated binge EtOH exposure. PMID:26283309

  2. Lying about facial recognition: an fMRI study.

    PubMed

    Bhatt, S; Mbwana, J; Adeyemo, A; Sawyer, A; Hailu, A; Vanmeter, J

    2009-03-01

    Novel deception detection techniques have been in creation for centuries. Functional magnetic resonance imaging (fMRI) is a neuroscience technology that non-invasively measures brain activity associated with behavior and cognition. A number of investigators have explored the utilization and efficiency of fMRI in deception detection. In this study, 18 subjects were instructed during an fMRI "line-up" task to either conceal (lie) or reveal (truth) the identities of individuals seen in study sets in order to determine the neural correlates of intentionally misidentifying previously known faces (lying about recognition). A repeated measures ANOVA (lie vs. truth and familiar vs. unfamiliar) and two paired t-tests (familiar vs. unfamiliar and familiar lie vs. familiar truth) revealed areas of activation associated with deception in the right MGF, red nucleus, IFG, SMG, SFG (with ACC), DLPFC, and bilateral precuneus. The areas activated in the present study may be involved in the suppression of truth, working and visuospatial memories, and imagery when providing misleading (deceptive) responses to facial identification prompts in the form of a "line-up". PMID:18848742

  3. Fetal MRI: A pictorial essay.

    PubMed

    Rathee, Sapna; Joshi, Priscilla; Kelkar, Abhimanyu; Seth, Nagesh

    2016-01-01

    Ultrasonography (USG) is the primary method for antenatal fetal evaluation. However, fetal magnetic resonance imaging (MRI) has now become a valuable adjunct to USG in confirming/excluding suspected abnormalities and in the detection of additional abnormalities, thus changing the outcome of pregnancy and optimizing perinatal management. With the development of ultrafast sequences, fetal MRI has made remarkable progress in recent times. In this pictorial essay, we illustrate a spectrum of structural abnormalities affecting the central nervous system, thorax, genitourinary and gastrointestinal tract, as well as miscellaneous anomalies. Anomalies in twin gestations and placental abnormalities have also been included.

  4. MRI EVALUATION OF KNEE CARTILAGE

    PubMed Central

    Rodrigues, Marcelo Bordalo; Camanho, Gilberto Luís

    2015-01-01

    Through the ability of magnetic resonance imaging (MRI) to characterize soft tissue noninvasively, it has become an excellent method for evaluating cartilage. The development of new and faster methods allowed increased resolution and contrast in evaluating chondral structure, with greater diagnostic accuracy. In addition, physiological techniques for cartilage assessment that can detect early changes before the appearance of cracks and erosion have been developed. In this updating article, the various techniques for chondral assessment using knee MRI will be discussed and demonstrated. PMID:27022562

  5. The Raven MRI teaching file

    SciTech Connect

    Lufkin, R.B.; Bradley, W.G. Jr.; Brant-Zawadzki, M.

    1990-01-01

    This book presents individually bound guides for each section of the body, the 1,000 concise and clearly illustrated case files cover neoplastic, non-neoplastic, degenerative, inflammatory, congenital, and acquired disease of the brain, head and neck, spine, musculoskeletal system, cardiovascular system, chest, abdomen, and male and female pelvis. It focuses on specific body regions; one is devoted to pediatric MRI; and one reviews the principles of MRI and identifies frequently encountered artifacts. It contains 100 completed case studies, with high-resolution MR images.

  6. Fetal MRI: A pictorial essay

    PubMed Central

    Rathee, Sapna; Joshi, Priscilla; Kelkar, Abhimanyu; Seth, Nagesh

    2016-01-01

    Ultrasonography (USG) is the primary method for antenatal fetal evaluation. However, fetal magnetic resonance imaging (MRI) has now become a valuable adjunct to USG in confirming/excluding suspected abnormalities and in the detection of additional abnormalities, thus changing the outcome of pregnancy and optimizing perinatal management. With the development of ultrafast sequences, fetal MRI has made remarkable progress in recent times. In this pictorial essay, we illustrate a spectrum of structural abnormalities affecting the central nervous system, thorax, genitourinary and gastrointestinal tract, as well as miscellaneous anomalies. Anomalies in twin gestations and placental abnormalities have also been included. PMID:27081224

  7. Repeated checking causes memory distrust.

    PubMed

    van den Hout, Marcel; Kindt, Merel

    2003-03-01

    This paper attempts to explain why in obsessive-compulsive disorder (OCD) checkers distrust in memory persists despite extensive checking. It is argued that: (1) repeated checking increases familiarity with the issues checked; (2) increased familiarity promotes conceptual processing which inhibits perceptual processing; (3) inhibited perceptual processing makes recollections less vivid and detailed and finally; (4) reduction in vividness and detail promotes distrust in memory. An interactive computer animation was developed in which participants had to perform checking rituals on a virtual gas stove. Two separate experiments were carried out with n=39 (Experiment I) and n=40 (Experiment II) healthy participants. In both studies, the control group and the experimental group were given the same pre-test and post-test on the virtual gas stove. In between, the experimental group engaged in 'relevant checking', i.e. checking the gas stove, while the control group engaged in 'irrelevant checking', i.e. checking virtual light bulbs. In both experiments there were powerful effects of repeated 'relevant checking': while actual memory accuracy remained unaffected, the vividness and detail of the recollections were greatly reduced. Most pertinently, in both experiments relevant checking undermined confidence in memory. No such effects were observed in the control group. One might argue that the pre-test/post-test design may have made the control group anticipate a memory assessment at the post-test and that this artifact made them relatively alert producing memory confidence at post test that was artificially high. A third experiment was carried out (n=2 x 20) in which no pre-test was given while, other than that, Experiment III was identical to the first two experiments. Results confirmed earlier findings: compared to the irrelevant checking control group, recollections in the relevant checking group were non-vivid, non-detailed while confidence in memory was low. The theory

  8. Patient-centeredness and quality management in Dutch diabetes care organizations after a 1-year intervention

    PubMed Central

    Campmans-Kuijpers, Marjo JE; Lemmens, Lidwien C; Baan, Caroline A; Rutten, Guy EHM

    2016-01-01

    Background More focus on patient-centeredness in care for patients with type 2 diabetes requests increasing attention to diabetes quality management processes on patient-centeredness by managers in primary care groups and outpatient clinics. Although patient-centered care is ultimately determined by the quality of interactions between patients and clinicians at the practice level, it should be facilitated at organizational level too. This nationwide study aimed to assess the state of diabetes quality management on patient-centeredness at organizational level and its possibilities to improve after a tailored intervention. Methods This before–after study compares the quality management on patient-centeredness within Dutch diabetes care groups and outpatient clinics before and after a 1-year stepwise intervention. At baseline, managers of 51 diabetes primary care groups and 28 outpatient diabetes clinics completed a questionnaire about the organization’s quality management program. Patient-centeredness (0%–100%) was operationalized in six subdomains: facilitating self-management support, individualized care plan support, patients’ access to medical files, patient education policy, safeguarding patients’ interests, and formal patient involvement. The intervention consisted of feedback and benchmark and if requested a telephone call and/or a consultancy visit. After 1 year, the managers completed the questionnaire again. The 1-year changes were examined by dependent (non) parametric tests. Results Care groups improved significantly on patient-centeredness (from 47.1% to 53.3%; P=0.002), and on its subdomains “access to medical files” (from 42.0% to 49.4%), and “safeguarding patients’ interests” (from 58.1% to 66.2%). Outpatient clinics, which scored higher at baseline (66.7%) than care groups, did not improve on patient-centeredness (65.6%: P=0.54) or its subdomains. “Formal patient involvement” remained low in both care groups (23.2%) and

  9. Dynamic Contrast-Enhanced MRI Evaluation of Cerebral Cavernous Malformations

    PubMed Central

    Hart, B. L.; Taheri, S.; Rosenberg, G. A.; Morrison, L. A.

    2013-01-01

    The aim of this study is to quantitatively evaluate the behavior of CNS cavernous malformations (CCMs) using a dynamic contrast-enhanced MRI (DCEMRI) technique sensitive for slow transfer rates of gadolinium. The prospective study was approved by the institutional review board and was HIPPA compliant. Written informed consent was obtained from 14 subjects with familial CCMs (4 men and 10 women, ages 22–76 years, mean 48.1 years). Following routine anatomic MRI of the brain, DCEMRI was performed for six slices, using T1 mapping with partial inversion recovery (TAPIR) to calculate T1 values, following administration of 0.025 mmol/kg gadolinium DTPA. The transfer rate (Ki) was calculated using the Patlak model, and Ki within CCMs was compared to normal-appearing white matter as well as to 17 normal control subjects previously studied. All subjects had typical MRI appearance of CCMs. Thirty-nine CCMs were studied using DCEMRI. Ki was low or normal in 12 lesions and elevated from 1.4 to 12 times higher than background in the remaining 27 lesions. Ki ranged from 2.1E–6 to 9.63E–4 min−1, mean 3.55E–4. Normal-appearing white matter in the CCM patients had a mean Ki of 1.57E–4, not statistically different from mean WM Ki of 1.47E–4 in controls. TAPIR-based DCEMRI technique permits quantifiable assessment of CCMs in vivo and reveals considerable differences not seen with conventional MRI. Potential applications include correlation with biologic behavior such as lesion growth or hemorrage, and measurement of drug effects. PMID:24323376

  10. Clinical, CSF, and MRI findings in Devic's neuromyelitis optica.

    PubMed Central

    O'Riordan, J I; Gallagher, H L; Thompson, A J; Howard, R S; Kingsley, D P; Thompson, E J; McDonald, W I; Miller, D H

    1996-01-01

    OBJECTIVES: Since Devic's original description of neuromyelitis optica in 1894 there has been much debate regarding its aetiology. A specific cause has been identified in a minority of cases but in most the question has arisen whether or not Devic's neuromyelitis optica is a variant of multiple sclerosis. This study was undertaken to help clarify this issue. METHODS: Neuromyelitis optica was defined as (1) a severe transverse myelitis; (2) an acute unilateral or bilateral optic neuropathy; (3) no clinical involvement beyond the spinal cord or optic nerves, and (4) a monophasic or multiphasic illness. The clinical and autoantibody status was documented. Patients underwent CSF examination and MRI of brain and spinal cord. RESULTS: Twelve patients, with a mean age of presentation of 35.1 years, were seen. Eleven were women; vision was reduced to counting fingers or worse in 10 patients and seven became confined to a wheelchair. Examination of CSF showed local synthesis of oligoclonal bands in only two patients and a neutrophil pleocytosis in two. A possible aetiology was identified in five: a specific connective tissue disorder (two), pulmonary tuberculosis (one), and possible acute disseminated encephalomyelitis (two). Six had non-specific increases in various autoantibodies. Eleven patients underwent MRI of the brain and spinal cord. In 10 there were diffuse abnormalities involving cervical and thoracic cords with extensive swelling in the acute phase. Brain MRI was normal in five; in five there were multiple deep white matter lesions, and one patient had minor age related changes. CONCLUSION: It is proposed that Devic's neuromyelitis optica is a distinctive disorder with some clinical, CSF, and MRI features different from those found in classic multiple sclerosis. In most cases a specific aetiology is not identified, but an immunological mechanism of tissue damage seems likely. Images PMID:8774400

  11. Paramagnetic lanthanide chelates for multicontrast MRI.

    PubMed

    Cakić, Nevenka; Savić, Tanja; Stricker-Shaver, Janice; Truffault, Vincent; Platas-Iglesias, Carlos; Mirkes, Christian; Pohmann, Rolf; Scheffler, Klaus; Angelovski, Goran

    2016-07-28

    The preparation of a paramagnetic chelator that serves as a platform for multicontrast MRI, and can be utilized either as a T1-weighted, paraCEST or (19)F MRI contrast agent is reported. Its europium(iii) complex exhibits an extremely slow water exchange rate which is optimal for the use in CEST MRI. The potential of this platform was demonstrated through a series of MRI studies on tube phantoms and animals. PMID:27291157

  12. Modeling Repeatedly Flaring δ Sunspots.

    PubMed

    Chatterjee, Piyali; Hansteen, Viggo; Carlsson, Mats

    2016-03-11

    Active regions (ARs) appearing on the surface of the Sun are classified into α, β, γ, and δ by the rules of the Mount Wilson Observatory, California on the basis of their topological complexity. Amongst these, the δ sunspots are known to be superactive and produce the most x-ray flares. Here, we present results from a simulation of the Sun by mimicking the upper layers and the corona, but starting at a more primitive stage than any earlier treatment. We find that this initial state consisting of only a thin subphotospheric magnetic sheet breaks into multiple flux tubes which evolve into a colliding-merging system of spots of opposite polarity upon surface emergence, similar to those often seen on the Sun. The simulation goes on to produce many exotic δ sunspot associated phenomena: repeated flaring in the range of typical solar flare energy release and ejective helical flux ropes with embedded cool-dense plasma filaments resembling solar coronal mass ejections.

  13. TOO Observations Soft Gamma Repeaters

    NASA Technical Reports Server (NTRS)

    vanParadijs, J.

    1998-01-01

    The goal of the project was to study the X-ray properties of the persistent and burst emission of Soft Gamma Repeaters (SGRs) during periods of burst activity. We monitored this activity with BATSE on the Compton Gamma-Ray Observatory, and made X-ray observations with the Rossi X-ray Timing Explorer (RXTE). SGR1806-20 became active in October 1996. We made observations with the PCA on the RXTE in November 1996. In the RXTE data we detected several hundred brief SGR events, which occurred in clear bunches, and persistent emission. From a Fouder analysis of the persistent emission (excluding time intervals with bursts) we found a period of 7.47 s. These pulsations are also present in RXTE data taken several weeks later (PI Dr. T. Strohmayer), which were combined with our data. Comparison with ASCA data taken in 1993 and 1995 shows that the period, which reflects the spin of a neutron star, increases on a time scale of 1500 years. These results show that SGR1 806-20 is a neutron star with a superstrong magnetic field (about 1"15) Gauss), thereby establishing, for the first time, the existence of magnetars.

  14. Observations of Soft Gamma Repeaters

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2005-01-01

    Magnetars (Soft Gamma Repeaters and Anomalous X-ray Pulsars) are a subclass of neutron stars characterized by their recurrent X-ray bursts. While in an active (bursting) state (lasting anywhere between days and years), they are emitting hundreds of predominantly soft (kl'=30 kev), short (0.1 - 100 ms long) events. Their quiescent source X-ray light curves exhibit pulsations in the narrow range of 5-1 1 s; estimates of these rotational period rate changes (spin-down) indicate that their magnetic fields are extremely high, of the order of 10A14-10A15 G. Such high B-field objects, dubbed "magnetars", had been predicted to exist in 1992, but the first concrete observational evidence was obtained in 1998 for two of these sources. Very recently, SGR1806-20 emitted a giant flare, which was detected in the radio with a multitude of telescopes under an extensive international campaign. These observations have revealed exciting new results, never seen before in any of the other magnetar sources. I will discuss here these results and their relevance to our understanding of the nature of magnetars.

  15. Cognitive dysfunction at baseline predicts symptomatic 1-year outcome in first-episode schizophrenics.

    PubMed

    Moritz, S; Krausz, M; Gottwalz, E; Lambert, M; Perro, C; Ganzer, S; Naber, D

    2000-01-01

    The present study addresses the consequences of cognitive disturbances on symptomatic outcome. Fifty-three first-episode schizophrenics were reassessed (n = 32) 1 year after admission. Simple regression analyses revealed that several self-perceived cognitive deficits at baseline as measured with the Frankfurt Complaint Questionnaire significantly predicted increased Brief Psychiatric Rating Scale global scores at follow-up (p = 0.05 to p = 0.005). A stepwise regression analysis proved memory dysfunction to be the strongest predictor of symptomatic worsening (p = 0.005). It is suggested that the exploration and treatment of neuropsychological deficits in schizophrenia is of great clinical importance with regard to its impact on both functional and symptomatic outcome in schizophrenia.

  16. Whooping cough in South-East Romania: a 1-year study.

    PubMed

    Dinu, Sorin; Guillot, Sophie; Dragomirescu, Cristiana Cerasella; Brun, Delphine; Lazăr, Stefan; Vancea, Geta; Ionescu, Biatrice Mariana; Gherman, Mariana Felicia; Bjerkestrand, Andreea-Florina-Dana; Ungureanu, Vasilica; Guiso, Nicole; Damian, Maria

    2014-03-01

    The incidence of whooping cough in Romania is substantially underestimated, and, as noted by the health authorities, this is mostly due to the lack of both awareness and biological diagnosis. We conducted a 1-year study in Bucharest in order to assess the circulation of Bordetella pertussis, the main etiological agent of whooping cough. Fifty-one subjects suspected of whooping cough were enrolled. Culture, real-time PCR, and enzyme-linked immunosorbent assay were used for laboratory diagnosis. Whooping cough patients (63%) were distributed among all age groups, and most were unvaccinated, incompletely vaccinated, or had been vaccinated more than 5 years previously. Bordetella holmesii DNA was detected in 22% of the bordetellosis cases; these patients included adults; teenagers; and, surprisingly, young children. B. pertussis isolates were similar to the clinical isolates currently circulating elsewhere in Europe. One isolate does not express pertactin, an antigen included in some acellular pertussis vaccines.

  17. Cognitive dysfunction at baseline predicts symptomatic 1-year outcome in first-episode schizophrenics.

    PubMed

    Moritz, S; Krausz, M; Gottwalz, E; Lambert, M; Perro, C; Ganzer, S; Naber, D

    2000-01-01

    The present study addresses the consequences of cognitive disturbances on symptomatic outcome. Fifty-three first-episode schizophrenics were reassessed (n = 32) 1 year after admission. Simple regression analyses revealed that several self-perceived cognitive deficits at baseline as measured with the Frankfurt Complaint Questionnaire significantly predicted increased Brief Psychiatric Rating Scale global scores at follow-up (p = 0.05 to p = 0.005). A stepwise regression analysis proved memory dysfunction to be the strongest predictor of symptomatic worsening (p = 0.005). It is suggested that the exploration and treatment of neuropsychological deficits in schizophrenia is of great clinical importance with regard to its impact on both functional and symptomatic outcome in schizophrenia. PMID:10601828

  18. Infants of adolescent mothers. Maternal characteristics and developmental status at 1 year of age.

    PubMed

    Camp, B W; Burgess, D; Morgan, L; Malpiede, D

    1984-03-01

    The Bayley Scales of Infant Development were administered at 1 year of age to 54 healthy infants of adolescent mothers. Information was obtained regarding maternal cognitive and emotional maturity, child-rearing attitudes, attitudes toward the infant, and psychosocial status at one year. The average Bayley Mental Scale score was 113, and the average Bayley Motor Scale score was 105. There was a negative correlation between the Bayley Mental Scale score and maternal age and education. Bayley Motor Scale scores were predictable from a combination of maternal authoritarian attitudes, abuse potential, and infant's birth weight. Although high authoritarian attitudes in mothers have been associated with poor cognitive development at later ages, they may represent an important strength in adolescent mothers during the first year. PMID:6702768

  19. Eosinophilic granulomatous gastroenterocolitis and hepatitis in a 1-year-old male Siberian Husky.

    PubMed

    Brellou, G D; Kleinschmidt, S; Meneses, F; Nolte, I; Hewicker-Trautwein, M

    2006-11-01

    A case of eosinophilic granulomatous gastroenterocolitis and hepatitis in a 1-year-old male Siberian Husky is described. The dog presented with a history of diarrhea, weakness, lethargy, and anorexia of several months' duration. Hematologic and biochemical examinations, abdominal ultrasonography, computer tomography, and exploratory laparotomy were performed. Histopathologic examination of full-thickness biopsies from the gastrointestinal tract and liver revealed the presence of eosinophilic granulomatous lesions in the submucosa and tunica muscularis of stomach, jejunum, ileum, colon, and liver. Infectious agents were not detected by light microscopic and electron microscopic examination or by immunohistochemistry. On the basis of the findings, it is concluded that the disease in this dog represents an unusual manifestation of chronic idiopathic inflammatory bowel disease.

  20. Exercise training prevents regain of visceral fat for 1 year following weight loss.

    PubMed

    Hunter, Gary R; Brock, David W; Byrne, Nuala M; Chandler-Laney, Paula C; Del Corral, Pedro; Gower, Barbara A

    2010-04-01

    The purpose of this study was to determine what effect aerobic and resistance exercise training has on gain of visceral fat during the year following weight loss. After being randomly assigned to aerobic training, resistance training, or no exercise training, 45 European-American (EA) and 52 African-American (AA) women lost 12.3 +/- 2.5 kg on a 800 kcal/day diet. Computed tomography was used to measure abdominal subcutaneous and visceral adipose tissue, whereas total fat and regional fat (leg, arm, and trunk) were measured by dual energy X-ray absorptiometry after weight loss and 1 year following the weight loss. Because not all the subjects adhered to the 2 time/week 40 min/day exercise training during the 1-year follow-up, subjects were divided into five groups for analysis: aerobic adherers, aerobic nonadherers, resistance adherers, resistance nonadherers, and no exercise. No significant differences were observed between the aerobic training and resistance training adherers for any variable. However, the aerobic (3.1 kg) and resistance (3.9 kg) exercise adherers gained less weight than any of the other three groups (all >6.2 kg). In addition, the two exercise adherence groups did not significantly increase visceral fat (<0.8%) as compared with the 38% increase for the two nonadhering exercise groups and the 25% for the nonexercise group. In conclusion, as little as 80 min/week aerobic or resistance training had modest positive effects on preventing weight regain following a diet-induced weight loss. More importantly, both aerobic and resistance training prevented regain of potentially harmful visceral fat.

  1. Sustained sympathetic and blood pressure reduction 1 year after renal denervation in patients with resistant hypertension.

    PubMed

    Hering, Dagmara; Marusic, Petra; Walton, Antony S; Lambert, Elisabeth A; Krum, Henry; Narkiewicz, Krzysztof; Lambert, Gavin W; Esler, Murray D; Schlaich, Markus P

    2014-07-01

    Renal denervation (RDN) reduces muscle sympathetic nerve activity (MSNA) and blood pressure (BP) in resistant hypertension. Although a persistent BP-lowering effect has been demonstrated, the long-term effect on MSNA remains elusive. We investigated whether RDN influences MSNA over time. Office BP and MSNA were obtained at baseline, 3, 6, and 12 months after RDN in 35 patients with resistant hypertension. Office BP averaged 166±22/88±19 mm Hg, despite the use of an average of 4.8±2.1 antihypertensive drugs. Baseline MSNA was 51±11 bursts/min ≈2- to 3-fold higher than the level observed in healthy controls. Mean office systolic and diastolic BP significantly decreased by -12.6±18.3/-6.5±9.2, -16.1±25.6/-8.6±12.9, and -21.2±29.1/-11.1±12.9 mm Hg (P<0.001 for both systolic BP and diastolic BP) with RDN at 3-, 6-, and 12-month follow-up, respectively. MSNA was reduced by -8±12, -6±12, and -6±11 bursts/min (P<0.01) at 3-, 6-, and 12-month follow-up. The reduction in MSNA was maintained, despite a progressive fall in BP over time. No such changes were observed in 7 control subjects at 6-month follow-up. These findings confirm previous reports on the favorable effects of RDN on elevated BP and demonstrate sustained reduction of central sympathetic outflow ≤1-year follow-up in patients with resistant hypertension and high baseline MSNA. These observations are compatible with the hypothesis of a substantial contribution of afferent renal nerve signaling to increased BP in resistant hypertension and argue against a relevant reinnervation at 1 year after procedure.

  2. Infant Aphakia Treatment Study: Effects of persistent fetal vasculature on outcome at 1 year of age

    PubMed Central

    Morrison, David G.; Wilson, M. Edward; Trivedi, Rupal H.; Lambert, Scott R.; Lynn, Michael J.

    2011-01-01

    Background The Infant Aphakia Treatment Study (IATS) is a randomized trial comparing the treatment of unilateral congenital cataract with primary intraocular lens (IOL) implantation versus aphakic contact lens (CL). The purpose of this study was to compare the outcomes for infants with lens opacity associated with persistent fetal vasculature (PFV) to those without. Methods Retrospective subgroup analysis of grating visual acuity at 1 year of age and adverse events up to 1 year after surgery in eyes identified intraoperatively as having evidence of mild PFV from the IATS. Results Of 83 infants, 18 (22%: 11 CL, 7 IOL) had PFV. Median logMAR visual acuity was 0.88 for patients with PFV and 0.80 for patients without PFV (P = 0.46). One or more adverse events up to one year after surgery occurred in 12 infants (67%) with PFV and 30 infants (46%) without PFV (P = 0.18). The incidence of adverse events was significantly higher in patients with PFV compared to patients without PFV in the CL group (55% vs 20%, P = 0.049) but not in the IOL group (86% vs 71%, P = 0.65), possibly because all children receiving IOLs had higher rates of adverse events when compared to aphakic children (73% vs 29%, P < 0.001). Conclusions Aphakic infants with mild PFV treated with CL had a higher incidence of adverse events following lensectomy compared to children with other forms of unilateral congenital cataract; nevertheless, similar visual outcomes at one year after surgery were obtained. PMID:22108353

  3. Metabolic Changes Following a 1-Year Diet and Exercise Intervention in Patients With Type 2 Diabetes

    PubMed Central

    Albu, Jeanine B.; Heilbronn, Leonie K.; Kelley, David E.; Smith, Steven R.; Azuma, Koichiro; Berk, Evan S.; Pi-Sunyer, F. Xavier; Ravussin, Eric

    2010-01-01

    OBJECTIVE To characterize the relationships among long-term improvements in peripheral insulin sensitivity (glucose disposal rate [GDR]), fasting glucose, and free fatty acids (FFAs) and concomitant changes in weight and adipose tissue mass and distribution induced by lifestyle intervention in obese individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS We measured GDR, fasting glucose, and FFAs during a euglycemic clamp and adipose tissue mass and distribution, organ fat, and adipocyte size by dual-energy X-ray absorptiometry, CT scan, and adipose tissue biopsy in 26 men and 32 women in the Look-AHEAD trial before and after 1 year of diet and exercise aimed at weight loss. RESULTS Weight and fasting glucose decreased significantly (P < 0.0001) and significantly more in men than in women (−12 vs. −8% and −16 vs. −7%, respectively; P < 0.05), while FFAs during hyperinsulinemia decreased and GDR increased significantly (P < 0.00001) and similarly in both sexes (−53 vs. −41% and 63 vs. 43%; P = NS). Men achieved a more favorable fat distribution by losing more from upper compared with lower and from deeper compared with superficial adipose tissue depots (P < 0.01). Decreases in weight and adipose tissue mass predicted improvements in GDR but not in fasting glucose or fasting FFAs; however, decreases in FFAs during hyperinsulinemia significantly determined GDR improvements. Hepatic fat was the only regional fat measure whose change contributed independently to changes in metabolic variables. CONCLUSIONS Patients with type 2 diabetes undergoing a 1-year lifestyle intervention had significant improvements in GDR, fasting glucose, FFAs and adipose tissue distribution. However, changes in overall weight (adipose tissue mass) and hepatic fat were the most important determinants of metabolic improvements. PMID:20028945

  4. Enteroaggregative Escherichia coli in Daycare—A 1-Year Dynamic Cohort Study

    PubMed Central

    Hebbelstrup Jensen, Betina; Stensvold, Christen R.; Struve, Carsten; Olsen, Katharina E. P.; Scheutz, Flemming; Boisen, Nadia; Röser, Dennis; Andreassen, Bente U.; Nielsen, Henrik V.; Schønning, Kristian; Petersen, Andreas M.; Krogfelt, Karen A.

    2016-01-01

    Enteroaggregative Escherichia coli (EAEC) has been associated with persistent diarrhea, reduced growth acceleration, and failure to thrive in children living in developing countries and with childhood diarrhea in general in industrialized countries. The clinical implications of an EAEC carrier-status in children in industrialized countries warrants clarification. To investigate the pathological significance of an EAEC carrier-state in the industrialized countries, we designed a 1-year dynamic cohort study and performed follow-up every second month, where the study participants submitted a stool sample and answered a questionnaire regarding gastrointestinal symptoms and exposures. Exposures included foreign travel, consumption of antibiotics, and contact with a diseased animal. In the capital area of Denmark, a total of 179 children aged 0–6 years were followed in a cohort study, in the period between 2009 and 2013. This is the first investigation of the incidence and pathological significance of EAEC in Danish children attending daycare facilities. Conventional microbiological detection of enteric pathogens was performed at Statens Serum Institute, Copenhagen, Denmark, and at Hvidovre Hospital, Copenhagen, Denmark. Parents completed questionnaires regarding gastrointestinal symptoms. The EAEC strains were further characterized by serotyping, phylogenetic analysis, and susceptibility testing. EAEC was detected in 25 (14%) of the children during the observational period of 1 year. One or more gastrointestinal symptoms were reported from 56% of the EAEC-positive children. Diarrhea was reported in six (24%) of the EAEC positive children, but no cases of weight loss, and general failure to thrive were observed. The EAEC strains detected comprised a large number of different serotypes, confirming the genetic heterogeneity of this pathotype. EAEC was highly prevalent (n = 25, 14%) in Danish children in daycare centers and was accompanied by gastrointestinal symptoms in

  5. Glomerular filtration rate in patients with atrial fibrillation and 1-year outcomes

    PubMed Central

    Boriani, Giuseppe; Laroche, Cécile; Diemberger, Igor; Popescu, Mircea Ioachim; Rasmussen, Lars Hvilsted; Petrescu, Lucian; Crijns, Harry J. G. M.; Tavazzi, Luigi; Maggioni, Aldo P.; Lip, Gregory Y. H.

    2016-01-01

    We assessed 1-year outcomes in patients with atrial fibrillation enrolled in the EurObservational Research Programme AF General Pilot Registry (EORP-AF), in relation to kidney function, as assessed by glomerular filtration rate (eGFR). In a cohort of 2398 patients (median age 69 years; 61% male), eGFR (ml/min/1.73 m2) calculated using the CKD-EPI formula was ≥80 in 35.1%, 50–79 in 47.2%, 30–49 in 13.9% and <30 in 3.7% of patients. In a logistic regression analysis, eGFR category was an independent predictor of stroke/TIA or death, with elevated odds ratios associated with severe to mild renal impairment, ie. eGFR < 30 ml/min/1.73 m2 [OR 3.641, 95% CI 1.572–8.433, p < 0.0001], 30–49 ml/min/1.73 m2 [OR 3.303, 95% CI 1.740–6.270, p = 0.0026] or 50–79 ml/min/1.73 m2 [OR 2.094, 95% CI 1.194–3.672, p = 0.0003]. The discriminant capability for the risk of death was tested among various eGFR calculation algorithms: the best was the Cockcroft-Gault equation adjusted for BSA, followed by Cockcroft-Gault equation, and CKD-EPI equation, while the worst was the MDRD equation. In conclusion in this prospective observational registry, renal function was a major determinant of adverse outcomes at 1 year, and even mild or moderate renal impairments were associated with an increased risk of stroke/TIA/death. PMID:27466080

  6. Quasar variability measurements with SDSS repeated imaging and POSS data

    NASA Astrophysics Data System (ADS)

    Ivezic, Ž.; Lupton, R. H.; Juric, M.; Anderson, S.; Hall, P. B.; Richards, G. T.; Rockosi, C. M.; vanden Berk, D. E.; Turner, E. L.; Knapp, G. R.; Gunn, J. E.; Schlegel, D.; Strauss, M. A.; Schneider, D. P.

    2004-11-01

    We analyze the properties of quasar variability using repeated SDSS imaging data in five UV-to-far red photometric bands, accurate to 0.02 mag, for ˜13,000 spectroscopically confirmed quasars. The observed time lags span the range from 3 hours to over 3 years, and constrain the quasar variability for rest-frame time lags of up to two years, and at rest-frame wavelengths from 1000Å to 6000Å. We demonstrate that ˜66,000 SDSS measurements of magnitude differences can be described within the measurement noise by a simple function of only three free parameters. The addition of POSS data constrains the long-term behavior of quasar variability and provides evidence for a turn-over in the structure function. This turn-over indicates that the characteristic time scale for optical variability of quasars is of the order 1 year.

  7. Cervical Spine MRI in Abused Infants.

    ERIC Educational Resources Information Center

    Feldman, Kenneth W.; And Others

    1997-01-01

    This study attempted to use cervical spine magnetic resonance imaging (MRI) to detect cord injury in 12 dead children with head injury from child abuse. Eighty percent of children autopsied had small cervical spine hemorrhages; MRI did not identify them and did not identify cord injury in any child studied, indicating that MRI scans are probably…

  8. Syntactic Priming and the Lexical Boost Effect during Sentence Production and Sentence Comprehension: An fMRI Study

    ERIC Educational Resources Information Center

    Segaert, Katrien; Kempen, Gerard; Petersson, Karl Magnus; Hagoort, Peter

    2013-01-01

    Behavioral syntactic priming effects during sentence comprehension are typically observed only if both the syntactic structure and lexical head are repeated. In contrast, during production syntactic priming occurs with structure repetition alone, but the effect is boosted by repetition of the lexical head. We used fMRI to investigate the neuronal…

  9. Strengthening concept learning by repeated testing

    PubMed Central

    Wiklund-Hörnqvist, Carola; Jonsson, Bert; Nyberg, Lars

    2014-01-01

    The aim of this study was to examine whether repeated testing with feedback benefits learning compared to rereading of introductory psychology key-concepts in an educational context. The testing effect was examined immediately after practice, after 18 days, and at a five-week delay in a sample of undergraduate students (n = 83). The results revealed that repeated testing with feedback significantly enhanced learning compared to rereading at all delays, demonstrating that repeated retrieval enhances retention compared to repeated encoding in the short- and the long-term. In addition, the effect of repeated testing was beneficial for students irrespectively of working memory capacity. It is argued that teaching methods involving repeated retrieval are important to consider by the educational system. PMID:24313425

  10. Strengthening concept learning by repeated testing.

    PubMed

    Wiklund-Hörnqvist, Carola; Jonsson, Bert; Nyberg, Lars

    2014-02-01

    The aim of this study was to examine whether repeated testing with feedback benefits learning compared to rereading of introductory psychology key-concepts in an educational context. The testing effect was examined immediately after practice, after 18 days, and at a five-week delay in a sample of undergraduate students (n = 83). The results revealed that repeated testing with feedback significantly enhanced learning compared to rereading at all delays, demonstrating that repeated retrieval enhances retention compared to repeated encoding in the short- and the long-term. In addition, the effect of repeated testing was beneficial for students irrespectively of working memory capacity. It is argued that teaching methods involving repeated retrieval are important to consider by the educational system.

  11. Repeat radiation synovectomy with dysprosium 165-ferric hydroxide macroaggregates in rheumatoid knees unresponsive to initial injection

    SciTech Connect

    Vella, M.; Zuckerman, J.D.; Shortkroff, S.; Venkatesan, P.; Sledge, C.B.

    1988-06-01

    Because of failure to fully respond to an initial intraarticular injection of dysprosium 165-ferric hydroxide macroaggregates, 17 patients with seropositive rheumatoid arthritis underwent repeat radiation synovectomy using this agent. Of the 13 patients who were evaluated 1 year later, 54% (7 knees) had good results, 31% (4 knees) had fair results, and 15% (2 knees) had poor results. The initial lack of significant benefit from radiation synovectomy did not appear to preclude a favorable response to a second injection.

  12. MRI Biosensors: A Short Primer

    PubMed Central

    Louie, Angelique

    2013-01-01

    Interest in Magnetic Resonance Imaging (MRI) contrast agents for molecular imaging of biological function experienced a surge of excitement approximately 20 years ago with the development of the first activatable contrast agents that could act as biosensors and turn “on” in response to a specific biological activity. This brief tutorial, based on a short course lecture from the 2011 ISMRM meeting, provides an overview of underlying principles governing the design of biosensing contrast agents. We describe mechanisms by which a magnetic resonance imaging (MRI) contrast agent can be made into a sensor for both T1 and T2 types contrast agents. Examples of biological activities that can interact with a contrast agent are discussed using specific examples from the recent literature to illustrate the primary mechanisms of action that have been utilized to achieve activation. MRI sensors for pH, ion binding, enzyme cleavage, and oxidation-reduction are presented. This article is not meant to be an exhaustive review, but an illustrative primer to explain how activation can be achieved for an MRI contrast agent. Chemical exchange saturation transfer (CEST) is not covered as these agents were covered in a separate lecture. PMID:23996662

  13. MRI of Little Leaguer's shoulder.

    PubMed

    Hatem, Stephen F; Recht, Michael P; Profitt, Brad

    2006-02-01

    The MRI appearance of 'Little Leaguer's shoulder' has not been previously reported in the radiology literature. Purported etiologies include proximal humeral epiphyseolysis, osteochondrosis of the proximal humeral epiphysis, stress fracture of the proximal humeral epiphyseal plate, and rotational stress fracture of the proximal humeral epiphyseal plate. We describe magnetic resonance imaging findings in four patients and review the literature.

  14. MRI findings in cobalamin deficiency.

    PubMed

    Krishna, Kavita K; Arafat, Abou-Sharbin Maher; Ichaporia, Nasli Rustom; Jain, M M

    2003-01-01

    A 55 year old male presented 2 years after a jejuno-iliectomy with weakness of all limbs, paraesthesiae, and difficulty in walking. Clinical examination revealed loss of posterior column sensations. Investigations were suggestive of a deficiency of vitamin B12 and folate. MRI showed a band of hyperintensity on T2 image, in the dorsal portion of the spinal cord.

  15. Short Tandem Repeat DNA Internet Database

    National Institute of Standards and Technology Data Gateway

    SRD 130 Short Tandem Repeat DNA Internet Database (Web, free access)   Short Tandem Repeat DNA Internet Database is intended to benefit research and application of short tandem repeat DNA markers for human identity testing. Facts and sequence information on each STR system, population data, commonly used multiplex STR systems, PCR primers and conditions, and a review of various technologies for analysis of STR alleles have been included.

  16. Understanding and identifying amino acid repeats.

    PubMed

    Luo, Hong; Nijveen, Harm

    2014-07-01

    Amino acid repeats (AARs) are abundant in protein sequences. They have particular roles in protein function and evolution. Simple repeat patterns generated by DNA slippage tend to introduce length variations and point mutations in repeat regions. Loss of normal and gain of abnormal function owing to their variable length are potential risks leading to diseases. Repeats with complex patterns mostly refer to the functional domain repeats, such as the well-known leucine-rich repeat and WD repeat, which are frequently involved in protein–protein interaction. They are mainly derived from internal gene duplication events and stabilized by ‘gate-keeper’ residues, which play crucial roles in preventing inter-domain aggregation. AARs are widely distributed in different proteomes across a variety of taxonomic ranges, and especially abundant in eukaryotic proteins. However, their specific evolutionary and functional scenarios are still poorly understood. Identifying AARs in protein sequences is the first step for the further investigation of their biological function and evolutionary mechanism. In principle, this is an NP-hard problem, as most of the repeat fragments are shaped by a series of sophisticated evolutionary events and become latent periodical patterns. It is not possible to define a uniform criterion for detecting and verifying various repeat patterns. Instead, different algorithms based on different strategies have been developed to cope with different repeat patterns. In this review, we attempt to describe the amino acid repeat-detection algorithms currently available and compare their strategies based on an in-depth analysis of the biological significance of protein repeats. PMID:23418055

  17. Can Dynamic Contrast-Enhanced MRI (DCE-MRI) and Diffusion-Weighted MRI (DW-MRI) Evaluate Inflammation Disease

    PubMed Central

    Zhu, Jianguo; Zhang, Faming; Luan, Yun; Cao, Peng; Liu, Fei; He, Wenwen; Wang, Dehang

    2016-01-01

    Abstract The aim of the study was to investigate diagnosis efficacy of dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI) in Crohn's disease (CD). To find out the correlations between functional MRI parameters including Ktrans, Kep, Ve, Vp, and apparent diffusion coefficient (ADC) with a serologic biomarker. The relationships between pharmacokinetic parameters and ADC were also studied. Thirty-two patients with CD (22 men, 10 women; mean age: 30.5 years) and 18 healthy volunteers without any inflammatory disease (10 men, 8 women; mean age, 34.11 years) were enrolled into this approved prospective study. Pearson analysis was used to evaluate the correlation between Ktrans, Kep, Ve, Vp, and C-reactive protein (CRP), ADC, and CRP respectively. The diagnostic efficacy of the functional MRI parameters in terms of sensitivity and specificity were analyzed by receiver operating characteristic (ROC) curve analyses. Optimal cut-off values of each functional MRI parameters for differentiation of inflammatory from normal bowel were determined according to the Youden criterion. Mean value of Ktrans in the CD group was significantly higher than that of normal control group. Similar results were observed for Kep and Ve. On the contrary, the ADC value was lower in the CD group than that in the control group. Ktrans and Ve were shown to be correlated with CRP (r = 0.725, P < 0.001; r = 0.533, P = 0.002), meanwhile ADC showed negative correlation with CRP (r = −0.630, P < 0.001). There were negative correlations between the pharmacokinetic parameters and ADC, such as Ktrans to ADC (r = −0.856, P < 0.001), and Ve to ADC (r = −0.451, P = 0.01). The area under the curve (AUC) was 0.994 for Ktrans (P < 0.001), 0.905 for ADC (P < 0.001), 0.806 for Ve (P < 0.001), and 0.764 for Kep (P = 0.002). The cut-off point of the Ktrans was found to be 0.931 min–1. This value provided the best trade-off between

  18. Approaching improved adhesive bonding repeatability

    NASA Astrophysics Data System (ADS)

    Schlette, Christian; Müller, Tobias; Roβmann, Jürgen; Brecher, Christian

    2016-03-01

    Today, the precision of micro-optics assembly is mostly limited by the accuracy of the bonding process ― and in the case of adhesive bonding by the prediction and compensation of adhesive shrinkage during curing. In this contribution, we present a novel approach to address adhesive bonding based on hybrid control system theory. In hybrid control, dynamic systems are described as "plants" which produce discrete and/or continuous outputs from given discrete and/or continuous inputs, thus yielding a hybrid state space description of the system. The task of hybrid controllers is to observe the plant and to generate a discrete and/or continuous input sequence that guides or holds the plant in a desired target state region while avoiding invalid or unwanted intermediate states. Our approach is based on a series of experiments carried out in order to analyze, define and decouple the dependencies of adhesive shrinkage on multiple parameters, such as application geometries, fixture forces and UV intensities. As some of the dependencies describe continuous effects (e.g. shrinkage from UV intensity) and other dependencies describe discrete state transitions (e.g. fixture removal during curing), the resulting model of the overall bonding process is a hybrid dynamic system in the general case. For this plant model, we then propose a concept of sampling-based parameter search as a basis to design suitable hybrid controllers, which have the potential to optimize process control for a selection of assembly steps, thus improving the repeatability of related production steps like beam-shaping optics or mounting of turning mirrors for fiber coupling.

  19. De Novo Repeat Classification and Fragment Assembly

    PubMed Central

    Pevzner, Paul A.; Tang, Haixu; Tesler, Glenn

    2004-01-01

    Repetitive sequences make up a significant fraction of almost any genome, and an important and still open question in bioinformatics is how to represent all repeats in DNA sequences. We propose a new approach to repeat classification that represents all repeats in a genome as a mosaic of sub-repeats. Our key algorithmic idea also leads to new approaches to multiple alignment and fragment assembly. In particular, we show that our FragmentGluer assembler improves on Phrap and ARACHNE in assembly of BACs and bacterial genomes. PMID:15342561

  20. Tandem repeats derived from centromeric retrotransposons

    PubMed Central

    2013-01-01

    Background Tandem repeats are ubiquitous and abundant in higher eukaryotic genomes and constitute, along with transposable elements, much of DNA underlying centromeres and other heterochromatic domains. In maize, centromeric satellite repeat (CentC) and centromeric retrotransposons (CR), a class of Ty3/gypsy retrotransposons, are enriched at centromeres. Some satellite repeats have homology to retrotransposons and several mechanisms have been proposed to explain the expansion, contraction as well as homogenization of tandem repeats. However, the origin and evolution of tandem repeat loci remain largely unknown. Results CRM1TR and CRM4TR are novel tandem repeats that we show to be entirely derived from CR elements belonging to two different subfamilies, CRM1 and CRM4. Although these tandem repeats clearly originated in at least two separate events, they are derived from similar regions of their respective parent element, namely the long terminal repeat (LTR) and untranslated region (UTR). The 5′ ends of the monomer repeat units of CRM1TR and CRM4TR map to different locations within their respective LTRs, while their 3′ ends map to the same relative position within a conserved region of their UTRs. Based on the insertion times of heterologous retrotransposons that have inserted into these tandem repeats, amplification of the repeats is estimated to have begun at least ~4 (CRM1TR) and ~1 (CRM4TR) million years ago. Distinct CRM1TR sequence variants occupy the two CRM1TR loci, indicating that there is little or no movement of repeats between loci, even though they are separated by only ~1.4 Mb. Conclusions The discovery of two novel retrotransposon derived tandem repeats supports the conclusions from earlier studies that retrotransposons can give rise to tandem repeats in eukaryotic genomes. Analysis of monomers from two different CRM1TR loci shows that gene conversion is the major cause of sequence variation. We propose that successive intrastrand deletions

  1. Vertebral Augmentation with Nitinol Endoprosthesis: Clinical Experience in 40 Patients with 1-Year Follow-up

    SciTech Connect

    Anselmetti, Giovanni Carlo; Manca, Antonio; Marcia, Stefano; Chiara, Gabriele; Marini, Stefano; Baroud, Gamal; Regge, Daniele; Montemurro, Filippo

    2013-05-08

    PurposeThis study was designed to assess the clinical outcomes of patients treated by vertebral augmentation with nitinol endoprosthesis (VNE) to treat painful vertebral compression fractures.MethodsForty patients with one or more painful osteoporotic VCF, confirmed by MRI and accompanied by back-pain unresponsive to a minimum 2 months of conservative medical treatment, underwent VNE at 42 levels. Preoperative and postoperative pain measured with Visual Analog Scale (VAS), disability measured by Oswestry Disability Index (ODI), and vertebral height restoration (measured with 2-dimensional reconstruction CT) were compared at last follow-up (average follow-up 15 months). Cement extravasation, subsequent fractures, and implant migration were recorded.ResultsLong-term follow-up was obtained in 38 of 40 patients. Both VAS and ODI significantly improved from a median of 8.0 (range 5–10) and 66 % (range 44–88 %) to 0.5 (range 0–8) and 6 % (range 6–66 %), respectively, at 1 year (p < 0.0001). Vertebral height measurements comparing time points increased in a statistically significant manner (ANOVA, p < 0.001). Overall cement extravasation rate was 9.5 %. Discal and venous leakage rates were 7.1 and 0 % respectively. No symptomatic extravasations occurred. Five of 38 (13.1 %) patients experienced new spontaneous, osteoporotic fractures. No device change or migration was observed.ConclusionsVNE is a safe and effective procedure that is able to provide long-lasting pain relief and durable vertebral height gain with a low rate of new fractures and cement leakages.

  2. A Case of West Nile Encephalitis That Develops into a Disease of Deep White Matter on MRI over a Two-Week Span

    PubMed Central

    Liu, Antonio

    2016-01-01

    We present a case of serologically proved West Nile encephalitis. This patient had a normal MRI on admission. Given that the patient's clinical picture had worsened during her admission, a repeat MRI was performed, which demonstrated diffuse disease in the deep white matter of the brain. This is a case of West Nice encephalitis presenting as a disease of deep white matter that developed over a two-week span. PMID:27703823

  3. Advances in Clinical PET/MRI Instrumentation.

    PubMed

    Herzog, Hans; Lerche, Christoph

    2016-04-01

    In 2010, the first whole-body PET/MRI scanners installed for clinical use were the sequential Philips PET/MRI with PMT-based, TOF-capable technology and the integrated simultaneous Siemens PET/MRI. Avalanche photodiodes as non-magneto-sensitive readout electronics allowed PET integrated within the MRI. The experiences with these scanners showed that improvements of software aspects, such as attenuation correction, were necessary and that efficient protocols combining optimally PET and MRI must be still developed. In 2014, General Electric issued an integrated PET/MRI with SiPM-based PET detectors, allowing TOF-PET. Looking at the MRI components of current PET/MR imaging systems, primary improvements come from sequences and new coils.

  4. Intraoperative, real-time, functional MRI.

    PubMed

    Gering, D T; Weber, D M

    1998-01-01

    Functional MRI (fMRI) methods have been demonstrated to noninvasively identify motor-sensory, visual, and other areas of eloquent cortex for guiding surgical intervention. Typically, fMRI data are acquired preoperatively during a conventional surgical planning MRI examination. Unlike direct cortical stimulation at the time of surgery, however, preoperative fMRI methods do not account for the potential movement of tissues (relative to the time of functional imaging) that may occur in the surgical suite as a direct result of the intervention. Recently, an MRI device has been demonstrated for use in the surgical suite that has the potential to reduce the extent of cortical exposure required for the intervention. However, the invasive requirements of cortical mapping may supersede the invasive requirements of the surgical intervention itself. Consequently, we demonstrate here a modification to the intraoperative MRI device that facilitates a noninvasive, real-time, functional MR examination in the surgical suite.

  5. Repeated adjacent-segment degeneration after posterior lumbar interbody fusion.

    PubMed

    Okuda, Shinya; Oda, Takenori; Yamasaki, Ryoji; Maeno, Takafumi; Iwasaki, Motoki

    2014-05-01

    One of the most important sequelae affecting long-term results is adjacent-segment degeneration (ASD) after posterior lumbar interbody fusion (PLIF). Although several reports have described the incidence rate, there have been no reports of repeated ASD. The purpose of this report was to describe 1 case of repeated ASD after PLIF. A 62-year-old woman with L-4 degenerative spondylolisthesis underwent PLIF at L4-5. At the second operation, L3-4 PLIF was performed for L-3 degenerative spondylolisthesis 6 years after the primary operation. At the third operation, L2-3 PLIF was performed for L-2 degenerative spondylolisthesis 1.5 years after the primary operation. Vertebral collapse of L-1 was detected 1 year after the third operation, and the collapse had progressed. At the fourth operation, 3 years after the third operation, vertebral column resection of L-1 and replacement of titanium mesh cages with pedicle screw fixation between T-4 and L-5 was performed. Although the patient's symptoms resolved after each operation, the time between surgeries shortened. The sacral slope decreased gradually although each PLIF achieved local lordosis at the fused segment.

  6. Depression and posttraumatic stress disorder in temporary settlement residents 1 year after the Sichuan earthquake.

    PubMed

    Cheng, Zhang; Ma, Ning; Yang, Lei; Agho, Kingsley; Stevens, Garry; Raphael, Beverley; Cui, Lijun; Liu, Yongqiao; Yan, Baoping; Ma, Hong; Yu, Xin

    2015-03-01

    The authors sought to determine the prevalence and risk factors for major depressive disorder and posttraumatic stress disorder (PTSD) among survivors living in temporary accommodation in the Yongxing settlement in Mianyang city 1 year after the Sichuan earthquake for further interventions. They interviewed 182 residents, using the Structured Clinical Interview for DSM-IV Axis I Disorders and a self-report questionnaire. The 12-month prevalence of depressive disorder and PTSD were 48.9% and 39.6%, respectively. Multivariate analysis indicated that bereaved survivors were 5.51 times (adjusted odds ratio [AOR] = 5.51; 95% confidence interval [CI] =2.14-14.22) more likely to report PTSD and 2.42 times (AOR = 2.42; 95%CI =1.00-5.48) more likely to report depressive disorder than nonbereaved survivors. Older age and receipt of government financial support were significantly associated with 12-month PTSD. Depressive disorder 12 months after the earthquake was associated with receipt of government financial support, pre-earthquake physical illness, single marital status, being currently employed, and Han ethnicity.

  7. A 1-year-old boy with persistent, generalized eruption. Urticaria pigmentosa.

    PubMed

    Mir, Adnan; Chamlin, Sarah L

    2014-01-01

    A healthy 1-year-old boy born at full term after an uncomplicated pregnancy presented to the dermatology clinic for a widespread eruption with gradual onset since 3 months of age. He was otherwise well, afebrile, feeding well, and gaining weight appropriately. The child was overall asymptomatic, though some of his lesions occasionally became red and pruritic. His mother noticed that after mild illnesses, he was more prone to these flares. She denied flushing, vomiting, diarrhea, respiratory distress, and irritability. He was meeting all developmental milestones and started walking at 11 months of age. The remainder of his review of systems was unremarkable, and family history was noncontributory. Physical exam revealed a well-appearing, well-nourished, playful, and interactive toddler. There were innumerable discrete and coalescing pink-brown macules and papules concentrated on the trunk and extending onto the proximal upper and lower extremities bilaterally, as well as the neck and lower face. Stroking the lesions quickly led to development of erythematous edematous wheals. There was no hepatosplenomegaly, and the lymph node exam was unremarkable.

  8. Ablation for atrial fibrillation during mitral valve surgery: 1-year results through continuous subcutaneous monitoring.

    PubMed

    Bogachev-Prokophiev, Alexandr; Zheleznev, Sergey; Romanov, Alexander; Pokushalov, Evgeny; Pivkin, Alexey; Corbucci, Giorgio; Karaskov, Alexander

    2012-07-01

    Continuous monitoring of cardiac rhythm may play an important role in measuring the true symptomatic/asymptomatic atrial fibrillation (AF) burden and improve the management of anti-arrhythmic and anti-thrombotic therapies. Forty-seven patients with mitral valve disease and longstanding persistent AF (LSPAF) underwent a left atrial maze procedure with bipolar radiofrequency and valve surgery. The follow-up data recorded by an implanted loop recorder were analysed after 3, 6 and 12 months. On discharge, 40 (85.1%) patients were in stable sinus rhythm, as documented by in-office electrocardiography (ECG), 4 (8.5%) were in pacemaker rhythm and 3 (6.4%) were in AF. One (2.1%) patient died after 7 months. On 12-month follow-up examination, 30 (65.2%) patients had an AF burden <0.5% and were classified as responders. Three (6.5%) of the 16 non-responders had atrial flutter and 13 (27.7%) had documented AF recurrences with an AF burden >0.5%. Two (4.3%) patients with AF recurrences were completely asymptomatic. Among the symptomatic events stored by the patients, only 27.6% was confirmed as genuine AF recurrences according to the concomitant ECG recorded by the implanted loop recorder. A concomitant bipolar maze procedure during mitral valve surgery is effective in treating AF, as proved by detailed 1-year continuous monitoring. PMID:22514258

  9. Hydrocephalus in children less than 1 year of age in northern Mozambique

    PubMed Central

    Salvador, Sérgio F.; Henriques, João Carlos; Munguambe, Missael; Vaz, Rui M. C.; Barros, Henrique P.

    2014-01-01

    Background: In developed countries, the incidence of neonatal hydrocephalus ranges from 3 to 5 cases per 1000 live births, but little is known about the frequency of hydrocephalus in Africa. In Mozambique, there is no primary information related to this disorder, but using the above data, the expected incidence of neonatal hydrocephalus would range from 2900 to 4800 cases per year. Methods: This study is based on 122 children younger than 1 year with neonatal hydrocephalus, followed up between January 2010 and December 2012, their origin and treatment, and aims to evaluate difficulties with diagnosis, treatment, and follow-up in northern Mozambique. Results: Identified cases were mainly less than 6 months old (77%), with severe macrocephaly and the classic stigmata of this condition. A high rate of follow-up loss (44.3%) was detected, particularly among children from more distant locations. Our findings contrast with the expected 1000-1700 cases that would occur in the area during the study period, being considerably lower. Conclusions: Hydrocephalus is a serious problem in sub-Saharan Africa, whose effects can be minimized by a better organization of the health system in hydrocephalus prevention, referral, and follow-up. New management alternatives to provide treatment to more children with this disorder and reduction of the follow-up difficulties caused due to geographical reasons for the children undergoing treatment are essential. PMID:25593759

  10. Beyond Earth: Weaving Science and Indigenous Culture - A 1-year NSF Planning Grant

    NASA Astrophysics Data System (ADS)

    Young, Timothy; Guy, M.; Baker Big-Back, C.; Froelich, K.

    2011-01-01

    We present results of a 1-year NSF planning grant called Beyond Earth. The project is designed to engage Native American, urban, and rural families in science learning while piloting curriculum development and implementation that incorporates both Native and Western epistemologies. Physical, earth, and space science content is juxtaposed with indigenous culture, stories, language and epistemology in after-school programs and teacher training. Project partners include the Dakota Science Center, Fort Berthold Community College, and Sitting Bull College. The Native American tribes represented in this initiative illustrate partnerships between the Dakota, Lakota, Nakota, Hidatsa, Mandan, and Arikara. Over the past year the primary project deliverables include a culturally responsive curriculum Beyond Earth Moon Module, teacher training workshops, a project website. The curriculum module introduces students to the moon's appearance, phases, and positions in the sky using the Night Sky Planetarium Experience Station to explore core concepts underlying moon phases and eclipses using the interactive Nature Experience Station before engaging in the culminating Mission Challenge in which they apply their knowledge to problem solving situations and projects. The Native Science and Western Science activities developed, planetarium explorations created, and website toolkit utilizations are presented.

  11. Results of 1 year of clinical experience with independent dose calculation software for VMAT fields

    PubMed Central

    Colodro, Juan Fernando Mata; Berna, Alfredo Serna; Puchades, Vicente Puchades; Amores, David Ramos; Baños, Miguel Alcaraz

    2014-01-01

    It is widely accepted that a redundant independent dose calculation (RIDC) must be included in any treatment planning verification procedure. Specifically, volumetric modulated arc therapy (VMAT) technique implies a comprehensive quality assurance (QA) program in which RIDC should be included. In this paper, the results obtained in 1 year of clinical experience are presented. Eclipse from Varian is the treatment planning system (TPS), here in use. RIDC were performed with the commercial software; Diamond® (PTW) which is capable of calculating VMAT fields. Once the plan is clinically accepted, it is exported via Digital Imaging and Communications in Medicine (DICOM) to RIDC, together with the body contour, and then a point dose calculation is performed, usually at the isocenter. A total of 459 plans were evaluated. The total average deviation was -0.3 ± 1.8% (one standard deviation (1SD)). For higher clearance the plans were grouped by location in: Prostate, pelvis, abdomen, chest, head and neck, brain, stereotactic radiosurgery, lung stereotactic body radiation therapy, and miscellaneous. The highest absolute deviation was -0.8 ± 1.5% corresponding to the prostate. A linear fit between doses calculated by RIDC and by TPS produced a correlation coefficient of 0.9991 and a slope of 1.0023. These results are very close to those obtained in the validation process. This agreement led us to consider this RIDC software as a valuable tool for QA in VMAT plans. PMID:25525309

  12. Attenuated hypothalamic-pituitary-adrenal axis functioning predicts accelerated pubertal development in girls 1 year later.

    PubMed

    Saxbe, Darby E; Negriff, Sonya; Susman, Elizabeth J; Trickett, Penelope K

    2015-08-01

    Accelerated pubertal development has been linked to adverse early environments and may heighten subsequent mental and physical health risks. Hypothalamic-pituitary-adrenal axis functioning has been posited as a mechanism whereby stress may affect pubertal development, but the literature lacks prospective tests of this mechanism. The current study assessed 277 youth (M = 10.84 years, SD = 1.14), 138 boys and 139 girls, who reported on their pubertal development and underwent the Trier Social Stress Test for Children at baseline and returned to the laboratory approximately 1 year later (M = 1.12 years, range = 0.59-1.98 years). For girls, lower cortisol area under the curve (with respect to ground) at Time 1 predicted more advanced pubertal development at Time 2, controlling for Time 1 pubertal development. This association persisted after additional covariates including age, body mass index, race, and maltreatment history were introduced, and was driven by adrenal rather than gonadal development. Cortisol was not linked to boys' subsequent pubertal development, and no interaction by gender or by maltreatment appeared. These results suggest that attenuated cortisol, reported in other studies of children exposed to early adversity, may contribute to accelerated pubertal tempo in girls.

  13. Efficacy and safety of tiotropium Respimat SMI in COPD in two 1-year randomized studies.

    PubMed

    Bateman, Eric; Singh, Dave; Smith, David; Disse, Bernd; Towse, Lesley; Massey, Dan; Blatchford, Jon; Pavia, Demetri; Hodder, Rick

    2010-08-09

    Two 1-year studies evaluated the long-term efficacy and safety of tiotropium 5 or 10 microg versus placebo, inhaled via the Respimat Soft Mist Inhaler (SMI). The two studies were combined and had 4 co-primary endpoints (trough FEV(1) response, Mahler Transition Dyspnea Index [TDI] and St George's Respiratory Questionnaire scores all at week 48, and COPD exacerbations per patient-year). A total of 1990 patients with COPD participated (mean FEV(1): 1.09 L). The mean trough FEV(1) response of tiotropium 5 or 10 microg relative to placebo was 127 or 150 mL, respectively (both P < 0.0001). The COPD exacerbation rate was significantly lower with tiotropium 5 microg (RR = 0.78; P = 0.002) and tiotropium 10 microg (RR = 0.73; P = 0.0008); the health-related quality of life and Mahler TDI co-primary endpoints were significantly improved with both doses (both P < 0.0001). Adverse events were generally balanced except anticholinergic class effects, which were more frequent with active treatment. Fatal events occurred in 2.4% (5 microg), 2.7% (10 microg), and 1.6% (placebo) of patients; these differences were not significant. Tiotropium Respimat SMI 5 microg demonstrated sustained improvements in patients with COPD relative to placebo and similar to the 10 microg dose but with a lower frequency of anticholinergic adverse events.

  14. The 1-year clinical impact of rotational aspiration atherectomy of infrainguinal lesions.

    PubMed

    Sixt, Sebastian; Rastan, Aljoscha; Scheinert, Dierk; Krankenberg, Hans; Steinkamp, Hermann; Schmidt, Andrej; Sievert, Horst; Minar, Erich; Bosiers, Marc; Peeters, Patrick; Balzer, Jörn O; Tübler, Thilo; Wissgott, Christian; Cancino, Oscar Gerardo Carpio; Schwarzwälder, Uwe; Zeller, Thomas

    2011-11-01

    The present study was carried out to provide information about outcome of the Jetstream atherectomy device for treatment of infrainguinal arteries. From February 2006 to February 2007, 172 patients with Rutherford class 1 to 5 lower limb ischemia were enrolled at 9 study sites. The endpoints were evaluation of quality of life according to the walking impairment questionnaire (WIQ) besides technical parameters. In the total study cohort, the WIQ scale maintained improved up to 12-month follow-up. Furthermore, target lesion revascularization rate was 26% (42/162), ankle-brachial index (ABI) increased from 0.59 ± 0.21 at baseline to 0.82 ± 0.27 (P < 0.05), and mean Rutherford class dropped from 3.0 ± 0.9 at baseline to 1.5 ± 1.3 at 1 year (P < .05). The results of this prospective, multicenter, clinical study demonstrate that the Jetstream atherectomy device is a potential treatment alternative for the endovascular management to improve clinical outcome in patients with peripheral arterial occlusive disease. PMID:21555314

  15. [The combined DAK therapy of obesity for children and adolescents. Evaluation after 1 year].

    PubMed

    Adam, S; Westenhöfer, J; Rudolphi, B; Kraaibeek, H K

    2008-04-10

    In 2003, the program "The combined DAK therapy of obesity for children and adolescents", funded and conducted by the Deutsche Angestellten Krankenkasse (DAK) (A German Health Insurance Company), has started. The whole treatment lasts for 1 year including an initial inpatient therapy for 6 weeks followed by an outpatient treatment at home that adresses the overweight patients and their families. The therapy contents are developed according to the recommendations of the "Arbeitsgemeinschaft Adipositas im Kindes- und Jugendalter (AGA)". In a prospective cohort study a sample of 604 subjects was studied in order to examine the achievement of the treatment goals weight reduction, behaviour modification and improvement of quality of life. The development of weight was evaluated using BMI-SDS. 44,1% of children and adolescents had a successful weight reduction, they reduced their weight at least by 0,3 BMI-SDS. Furthermore, significant changes of health behaviour, physical fitness and quality of life were observed. However, during the outpatient treatment an impairment of some behaviour changes were observed. Nevertheless, the study has identified significant, positive effects in weight loss, behaviour modifications, changes in physical fitness and in the development of quality of life as a result of the therapy. It is demonstrated that a relapse in "old behaviour" followed by an increase of weight after the inpatient treatment can be avoided bythe subsequent outpatient therapy.

  16. The first simultaneous kidney-adrenal gland-pancreas transplantation: outcome at 1 year.

    PubMed

    Vouillarmet, J; Buron, F; Houzard, C; Carlier, M C; Chauvet, C; Brunet, M; Thivolet, C; Morelon, E; Badet, L

    2013-07-01

    Adrenal insufficiency is a rare but life-threatening disease. Replacement therapy sometimes fails to prevent an acute adrenal crisis and most often does not lead to restoration of well-being. We report here the 1-year outcome of the first simultaneous kidney-adrenal gland-pancreas transplantation in a 33-year-old patient with type 1 diabetes and concomitant autoimmune adrenal insufficiency. En bloc left adrenal gland and kidney grafts were anastomosed on the left iliac vessels in normal vascular conditions and the pancreas graft was anastomosed on the right iliac vessels. The immunosuppressive regimen was not modified by the addition of the adrenal gland. We observed no additional morbidity due to the adrenal gland transplantation, as there were no surgical complications. One-year kidney and pancreas graft functions were satisfactory (estimated glomerular filtration rate: 55 mL/min/1.73 m(2) and HbA1c: 4.8%). The adrenal graft functioned well at 12 months with a normalization of cortisol and aldosterone baseline levels. Functional imaging at 3 months showed good uptake of [(123) I]-metaiodobenzylguanidine by the adrenal graft. Transplantation of the adrenal gland en bloc with the left kidney appears to be a good therapeutic option in patients with adrenal insufficiency awaiting kidney or kidney-pancreas transplantation.

  17. Change in Metabolic Profile after 1-Year Nutritional-Behavioral Intervention in Obese Children.

    PubMed

    Verduci, Elvira; Lassandro, Carlotta; Giacchero, Roberta; Miniello, Vito Leonardo; Banderali, Giuseppe; Radaelli, Giovanni

    2015-12-03

    Research findings are inconsistent about improvement of specific cardio-metabolic variables after lifestyle intervention in obese children. The aim of this trial was to evaluate the effect of a 1-year intervention, based on normocaloric diet and physical activity, on body mass index (BMI), blood lipid profile, glucose metabolism and metabolic syndrome. Eighty-five obese children aged ≥6 years were analyzed. The BMI z-score was calculated. Fasting blood samples were analyzed for lipids, insulin and glucose. The homeostatic model assessment of insulin resistance (HOMA-IR) was calculated and insulin resistance was defined as HOMA-IR >3.16. HOMA-β%, quantitative insulin sensitivity check index and triglyceride glucose index were calculated. The metabolic syndrome was defined in accordance with the International Diabetes Federation criteria. At the end of intervention children showed a reduction (mean (95% CI)) in BMI z-score (-0.58 (-0.66; -0.50)), triglycerides (-0.35 (-0.45; -0.25) mmol/L) and triglyceride glucose index (-0.29 (-0.37; -0.21)), and an increase in HDL cholesterol (0.06 (0.01; 0.11) mmol/L). Prevalence of insulin resistance declined from 51.8% to 36.5% and prevalence of metabolic syndrome from 17.1% to 4.9%. Nutritional-behavioral interventions can improve the blood lipid profile and insulin sensitivity in obese children, and possibly provide benefits in terms of metabolic syndrome.

  18. Hippocampal Neuron Number Is Unchanged 1 Year After Fractionated Whole-Brain Irradiation at Middle Age

    SciTech Connect

    Shi Lei Molina, Doris P.; Robbins, Michael E.; Wheeler, Kenneth T.; Brunso-Bechtold, Judy K.

    2008-06-01

    Purpose: To determine whether hippocampal neurons are lost 12 months after middle-aged rats received a fractionated course of whole-brain irradiation (WBI) that is expected to be biologically equivalent to the regimens used clinically in the treatment of brain tumors. Methods and Materials: Twelve-month-old Fischer 344 X Brown Norway male rats were divided into WBI and control (CON) groups (n = 6 per group). Anesthetized WBI rats received 45 Gy of {sup 137}Cs {gamma} rays delivered as 9 5-Gy fractions twice per week for 4.5 weeks. Control rats were anesthetized but not irradiated. Twelve months after WBI completion, all rats were anesthetized and perfused with paraformaldehyde, and hippocampal sections were immunostained with the neuron-specific antibody NeuN. Using unbiased stereology, total neuron number and the volume of the neuronal and neuropil layers were determined in the dentate gyrus, CA3, and CA1 subregions of hippocampus. Results: No differences in tissue integrity or neuron distribution were observed between the WBI and CON groups. Moreover, quantitative analysis demonstrated that neither total neuron number nor the volume of neuronal or neuropil layers differed between the two groups for any subregion. Conclusions: Impairment on a hippocampal-dependent learning and memory test occurs 1 year after fractionated WBI at middle age. The same WBI regimen, however, does not lead to a loss of neurons or a reduction in the volume of hippocampus.

  19. Effect of iodine supplementation during pregnancy on infant neurodevelopment at 1 year of age.

    PubMed

    Murcia, Mario; Rebagliato, Marisa; Iñiguez, Carmen; Lopez-Espinosa, Maria-Jose; Estarlich, Marisa; Plaza, Belén; Barona-Vilar, Carmen; Espada, Mercedes; Vioque, Jesús; Ballester, Ferran

    2011-04-01

    Iodine is the main constituent of thyroid hormones, which in turn are required for fetal brain development. However, the relation between iodine intake during pregnancy, thyroid function, and child neurodevelopment needs further evaluation. The authors assessed the association of maternal iodine intake from diet and supplements during pregnancy and of maternal and neonatal thyroid function with infant neurodevelopment. The Mental Development Index and Psychomotor Development Index (PDI) for 691 children were obtained between 2005 and 2007 using the Bayley Scales of Infant Development at age 1 year in a prebirth cohort in Valencia, Spain. In multivariate analyses, a maternal thyrotropin level >4 μU/mL was associated with an increased risk of a PDI <85 (odds ratio = 3.5, P = 0.02). Maternal intake of ≥150 μg/day, compared with <100 μg/day, of iodine from supplements was associated with a 5.2-point decrease in PDI (95% confidence interval: -8.1, -2.2) and a 1.8-fold increase in the odds of a PDI <85 (95% confidence interval: 1.0, 3.3). When analyses were stratified by sex, this association was intensified for girls but was not observed for boys. Further evidence on the safety and effectiveness of iodine supplementation during pregnancy is needed before it is systematically recommended in iodine-sufficient or mildly deficient areas. PMID:21385833

  20. Acutely Suicidal Adolescents Who Engage in Bullying Behavior: 1-Year Trajectories

    PubMed Central

    King, Cheryl A.; Horwitz, Adam; Berona, Johnny; Jiang, Qingmei

    2013-01-01

    Purpose Prospective longitudinal research is needed to examine associations between bullying behaviors and trajectories of suicidal ideation and behavior and overall functional impairment. The specific aims of the present study are to: (1) characterize differences in baseline functioning between acutely suicidal adolescents who are classified into bullying perpetrator and non-bully groups and (2) examine the 1-year trajectories of these two groups of adolescents. Method Participants were 433 psychiatrically hospitalized suicidal adolescents (72% female), ages 13 to 17 years. Participants reported suicidal ideation, depression, anxiety, substance use, adaptive functioning, and bullying behavior. Six items from the Youth Self-Report were used to classify adolescents into bullying perpetrator (n = 54) and non-bully (n = 379) groups. Follow-up assessments were conducted at 6 weeks, 3 months, 6 months, and 12 months. Results At hospitalization, adolescents in the bully group reported significantly higher levels of suicidal ideation, substance use, and functional impairment. Suicidal ideation differences remitted at six weeks. The elevated functional impairment of the bullying perpetrator group persisted across the 12-month period. Conclusion Adolescents who met bullying perpetrator group criteria were characterized by more severe suicidal ideation and higher levels of proximal risk factors for suicide. Bullying behavior was not stable over time but was associated with elevated suicide risk when present. These findings highlight the importance of specifically assessing for and targeting bullying behavior at multiple time points when treating suicidal adolescents. PMID:23790201

  1. Congenital abnormality of the vagina complicated by haemato-pyocolpos in a 1-year labrador retriever.

    PubMed

    Alonge, S; Romussi, S; Grieco, V; Luvoni, G C

    2015-06-01

    A 1-year-old female Labrador retriever was referred with a few days history of haematic-like vulvar discharge. Physical examination, vaginal inspection and palpation did not reveal any remarkable finding. Transabdominal ultrasound showed echogenic fluid accumulation in the vagina suggesting haemato-pyocolpos. An exploratory laparotomy was performed: a well-delimited ectasic vagina was identified. Ovariohysterectomy and partial vaginectomy and vaginoplasty were performed to spay the bitch and to remove the ectasic vagina. Post-operative recovery and 12-month follow-up were uneventful. Clinical, morphological and histological findings were consistent with a congenital abnormality of the muscular layer of the vagina complicated by haemato-pyocolpos. The disorganization of the vaginal tunica muscularis may have acted as locus minoris resistentiae in the vaginal wall. The organ was dilated and atonic due to the gradual accumulation of physiological fluids complicated by an overgrowth of genital bacteria. This congenital disorder has to be taken into account as differential diagnosis of haemato-pyocolpos with vaginal discharge in young bitches.

  2. Facial sensibility in adolescents with and without clefts 1 year after undergoing Le Fort I osteotomy.

    PubMed

    Posnick, J C; al-Qattan, M M; Pron, G

    1994-09-01

    Static two-point discrimination, pressure, and vibratory threshold values were measured at standard coordinates in the area corresponding to the infraorbital nerve distribution in 59 adolescents 1 year after undergoing LeFort I osteotomy. The patients were divided into three groups: those born with unilateral cleft lip and palate (n = 30; mean age, 18 years; SD = 2); those with bilateral cleft lip and palate (n = 12; mean age, 19 years; SD = 3); and those without a cleft (n = 17; mean age, 19 years; SD = 3). One year after the osteotomy, none of the patients complained of altered sensibility in the maxillary vestibular mucosa, gingiva, or upper lip and cheek regions. No significant differences were found between the mean postoperative sensibility values of patients with and without clefts, indicating that the presence of clefting did not affect sensory recovery. Mean postoperative static two-point discrimination values were higher than preoperative values in all areas tested and in all patient groups. These results suggest that the sensory recovery, although incomplete, was strong enough to mask any subjective feelings of changes in sensory function.

  3. A 1-year-old boy with persistent, generalized eruption. Urticaria pigmentosa.

    PubMed

    Mir, Adnan; Chamlin, Sarah L

    2014-01-01

    A healthy 1-year-old boy born at full term after an uncomplicated pregnancy presented to the dermatology clinic for a widespread eruption with gradual onset since 3 months of age. He was otherwise well, afebrile, feeding well, and gaining weight appropriately. The child was overall asymptomatic, though some of his lesions occasionally became red and pruritic. His mother noticed that after mild illnesses, he was more prone to these flares. She denied flushing, vomiting, diarrhea, respiratory distress, and irritability. He was meeting all developmental milestones and started walking at 11 months of age. The remainder of his review of systems was unremarkable, and family history was noncontributory. Physical exam revealed a well-appearing, well-nourished, playful, and interactive toddler. There were innumerable discrete and coalescing pink-brown macules and papules concentrated on the trunk and extending onto the proximal upper and lower extremities bilaterally, as well as the neck and lower face. Stroking the lesions quickly led to development of erythematous edematous wheals. There was no hepatosplenomegaly, and the lymph node exam was unremarkable. PMID:24549082

  4. Laboratory Tests Ordered By a Chiropractic Sports Physician on Elite Athletes Over a 1-Year Period

    PubMed Central

    Nabhan, Dustin C.; Moreau, William J.; Barylski, Chad

    2015-01-01

    Objective The purpose of this study is to describe and discuss laboratory tests ordered on elite athletes in an interdisciplinary sports medicine clinic by a doctor of chiropractic over 1 calendar year. Methods A retrospective review of laboratory tests ordered during routine clinical practice as standard screening and diagnostic tests from November 1, 2009, to November 1, 2010 was performed. Data were collected during clinical encounters at one sports medicine clinic and entered into a database for analysis. Descriptive and frequency statistics were used to describe the tests ordered and the frequency of abnormal findings. Results Five hundred and thirty-nine studies were ordered for diagnostic and routine screenings on 137 athlete patients (86 males, 51 females), representing 49 types of tests. Sample sources included blood, urine, skin lesions, and fecal matter. The most commonly ordered tests were complete blood count, comprehensive metabolic panel, serum ferritin, creatine kinase, serum iron and total iron binding capacity, total cortisol, thyroid stimulating hormone, and lipid panels. There were 217 studies (40%) flagged as abnormal by the reporting laboratory. Conclusion This report provides greater insight into the diverse array of laboratory studies ordered over a 1-year period for diagnosis and screening of elite athletes. A high percentage of the results were flagged as abnormal by the laboratory. These findings show that the unique physiology of the elite athlete must be considered when interpreting laboratory findings in this population. PMID:26257590

  5. A MRI-CT prostate registration using sparse representation technique

    NASA Astrophysics Data System (ADS)

    Yang, Xiaofeng; Jani, Ashesh B.; Rossi, Peter J.; Mao, Hui; Curran, Walter J.; Liu, Tian

    2016-03-01

    Purpose: To develop a new MRI-CT prostate registration using patch-based deformation prediction framework to improve MRI-guided prostate radiotherapy by incorporating multiparametric MRI into planning CT images. Methods: The main contribution is to estimate the deformation between prostate MRI and CT images in a patch-wise fashion by using the sparse representation technique. We assume that two image patches should follow the same deformation if their patch-wise appearance patterns are similar. Specifically, there are two stages in our proposed framework, i.e., the training stage and the application stage. In the training stage, each prostate MR images are carefully registered to the corresponding CT images and all training MR and CT images are carefully registered to a selected CT template. Thus, we obtain the dense deformation field for each training MR and CT image. In the application stage, for registering a new subject MR image with the same subject CT image, we first select a small number of key points at the distinctive regions of this subject CT image. Then, for each key point in the subject CT image, we extract the image patch, centered at the underlying key point. Then, we adaptively construct the coupled dictionary for the underlying point where each atom in the dictionary consists of image patches and the respective deformations obtained from training pair-wise MRI-CT images. Next, the subject image patch can be sparsely represented by a linear combination of training image patches in the dictionary, where we apply the same sparse coefficients to the respective deformations in the dictionary to predict the deformation for the subject MR image patch. After we repeat the same procedure for each subject CT key point, we use B-splines to interpolate a dense deformation field, which is used as the initialization to allow the registration algorithm estimating the remaining small segment of deformations from MRI to CT image

  6. Evaluating a Group Repeated Reading Intervention

    ERIC Educational Resources Information Center

    Klubnik, Cynthia Adele

    2009-01-01

    Fluency has been identified as an important component of effective reading instruction, and repeated reading has been shown to improve oral reading fluency. In order to improve the efficiency of repeated reading interventions, more research is needed on the effectiveness of small group reading interventions. An alternating treatments, single…

  7. The Effects of Repeaters on Test Equating.

    ERIC Educational Resources Information Center

    Andrulis, Richard S.; And Others

    1978-01-01

    The effects of repeaters (testees included in both administrations of two forms of a test) on the test equating process are examined. It is shown that repeaters do effect test equating and tend to lower the cutoff point for passing the test. (JKS)

  8. The Effects of Repeaters on Test Equating.

    ERIC Educational Resources Information Center

    Andrulis, Richard S.; And Others

    The purpose of this investigation was to establish the effects of repeaters on test equating. Since consideration was not given to repeaters in test equating, such as in the derivation of equations by Angoff (1971), the hypothetical effect needed to be established. A case study was examined which showed results on a test as expected; overall mean…

  9. Integration of DCE-MRI and DW-MRI Quantitative Parameters for Breast Lesion Classification

    PubMed Central

    Fusco, Roberta; Sansone, Mario; Filice, Salvatore; Granata, Vincenza; Catalano, Orlando; Amato, Daniela Maria; Di Bonito, Maurizio; D'Aiuto, Massimiliano; Capasso, Immacolata; Rinaldo, Massimo; Petrillo, Antonella

    2015-01-01

    Objective. The purpose of our study was to evaluate the diagnostic value of an imaging protocol combining dynamic contrast-enhanced MRI (DCE-MRI) and diffusion-weighted MRI (DW-MRI) in patients with suspicious breast lesions. Materials and Methods. A total of 31 breast lesions (15 malignant and 16 benign proved by histological examination) in 26 female patients were included in this study. For both DCE-MRI and DW-MRI model free and model based parameters were computed pixel by pixel on manually segmented ROIs. Statistical procedures included conventional linear analysis and more advanced techniques for classification of lesions in benign and malignant. Results. Our findings indicated no strong correlation between DCE-MRI and DW-MRI parameters. Results of classification analysis show that combining of DCE parameters or DW-MRI parameter, in comparison of single feature, does not yield a dramatic improvement of sensitivity and specificity of the two techniques alone. The best performance was obtained considering a full combination of all features. Moreover, the classification results combining all features are dominated by DCE-MRI features alone. Conclusion. The combination of DWI and DCE-MRI does not show a potential to dramatically increase the sensitivity and specificity of breast MRI. DCE-MRI alone gave the same performance as in combination with DW-MRI. PMID:26339597

  10. Cortical and Subcortical Changes in Alzheimer's Disease: A Longitudinal and Quantitative MRI Study.

    PubMed

    Su, Li; Blamire, Andrew M; Watson, Rosie; He, Jiabao; Aribisala, Benjamin; O'Brien, John T

    2016-01-01

    Quantitative MRI provides important information about tissue properties in brain both in normal ageing and in degenerative disorders. Although it is well known that those with Alzheimer's disease (AD) show a specific pattern and faster rate of atrophy than controls, the precise spatial and temporal patterns of quantitative MRI in AD are unknown. We aimed to investigate neuroimaging correlates of AD using serial quantitative MRI. In our study, twenty-one subjects with AD and thirty-two similar-aged healthy controls underwent two serial MRI scans at baseline and 12 months. Tissue characteristics were captured using two quantitative MRI parameters: longitudinal relaxation time (qT1) and transverse relaxation time (qT2). The two groups (AD and controls) were statistically compared using a voxel based quantification (VBQ) method based on Matlab and SPM8. At baseline, subjects with AD showed a significant reduction of qT1 and qT2 compared to controls in bilateral temporal and parietal lobes, hippocampus, and basal ganglia. This pattern was also observed at follow-up. Longitudinally, in AD we found a significant increase rather than further reduction of qT1 and qT2 from the baseline in bilateral hippocampus, thalamus and right caudate nucleus. In addition, the longitudinal change of qT1 in left hippocampus was negatively correlated with cognitive decline in AD over the 1-year period, and the general disease severity significantly predicted the amount of increase of qT1 in bilateral hippocampus over 12 months. The longitudinal change of qT2 in left parahippocampus correlated with change in neuropsychiatric features over time. In summary, quantitative MRI parameters were reduced in AD cross-sectionally, but increased over time, showing distinct spatiotemporal patterns from the atrophy in AD. We also showed the clinical relevance of quantitative MRI parameters, indicating their potential promise as new imaging markers in AD.

  11. Radio-frequency ablation of small renal tumors: minimum follow up of 1 year

    NASA Astrophysics Data System (ADS)

    Patel, Vipul; Thaly, Rahul; Shah, Ketul

    2007-02-01

    OBJECTIVE: With the increased utility of complex imaging modalities small renal tumors are being diagnosed with rising frequency. We performed radiofrequency ablation to treat tumors less than 4cm in size using a combination of temperature, impedance, ultrasound and laparoscopic guidance. In this article we reviewed the outcome of radiofrequency ablation of renal tumors at one year at our institution. MATERIALS AND METHODS: Over a three-year period 75 patients with a total of 93 renal tumors underwent radiofrequency ablation. Average patient age was 64.5 years with ASA of 2.9. Indications for nephron sparing were imperative in 33 (solitary kidney 21, renal insufficiency 12). Seventeen patients had significant co-morbidities with ASA score of 3 or more and were thought to be poor candidates for nephrectomy or partial nephrectomy. Five were Jehovah's Witness patients. Average tumor size was 3.2 cm (1.5-4.0). 60% of the tumors were exophytic and 40% deep. Radiofrequency ablation was performed via a transperitoneal approach using the single pronged 3cm Cool tip electrode (Radionics Inc). Tumor was isolated laparoscopically. Prior to ablation the lesions were biopsied. Ablation was performed using both laparoscopic and real-time ultrasound imaging of the boarders of the tumor. During ablation impedance and temperature monitoring was performed. For each tumor two separate ablations were performed at perpendicular angles, the first ablation was for 6 minutes and the second for 3 minutes. The center and periphery of the tumor was monitored to insure that the temperature rose above 70 degrees Celsius. Patients were followed at three-month intervals with triple phase CT scan or MRI to evaluate efficacy of the ablation. Our criteria for recurrent tumor were growth or enhancement of the lesion. RESULTS: Average operative time was 109 minutes with and average EBL of <25cc. Mean hospital stay was 1.4 days. At average follow up of 19.2 months (range 2-24), one lesion showed

  12. [Perioperative anesthetic exposure and the neurodevelopmental status of 1 year old baby underwent neonatal cardiac surgery].

    PubMed

    Chen, Xuejun; Wan, Yongling; Wen, Kailan; Liang, Tao; Lin, Tao; Li, Peng

    2015-11-01

    目的:探讨新生儿心脏手术的围手术期麻醉暴露与1岁时的神经发育结果的相关性。方法:选取四川省人民医院行心脏手术的新生儿115例,纳入队列研究,于术前和术后7 d行大脑磁共振(MRI),记录围手术期挥发性麻醉药、苯二氮卓类与阿片类药物使用情况,患儿1岁时应用贝利婴幼儿发展量表评估患儿的认知、语言和运动情况,在矫正其他协变量基础上分析它们的相关性。结果:共有92例患儿被纳入研究,患儿1岁时贝利婴幼儿发展量表认知、语言和运动的分值分别为104.2±14.7,85.6±11.3和86.9±13.5;术前MRI显示颅脑损伤17例,术后MRI显示颅脑损伤25例。多重线性回归分析显示与1岁神经发育结果相关的因素包括MRI显示术后脑损伤、挥发性麻醉药的最低肺泡有效浓度、芬太尼总质量浓度、苯二氮卓类总质量浓度、ICU住院时间、术前平均区域脑氧饱和度和染色体异常。结论:挥发性麻醉药暴露、术后MRI显示脑损伤以及长ICU住院时间是患儿1岁时神经发育预后差的影响因素。需要采取针对性的措施,降低围手术期致神经损伤的危险因素。.

  13. MRI morphometry in Alzheimer's disease.

    PubMed

    Matsuda, Hiroshi

    2016-09-01

    MRI based evaluation of brain atrophy is regarded as a valid method to stage the disease and to assess progression in Alzheimer's disease (AD). Volumetric software programs have made it possible to quantify gray matter in the human brain in an automated fashion. At present, voxel based morphometry (VBM) is easily applicable to the routine clinical procedure with a short execution time. The importance of the VBM approach is that it is not biased to one particular structure and is able to assess anatomical differences throughout the brain. Stand-alone VBM software running on Windows, Voxel-based Specific Regional analysis system for AD (VSRAD), has been widely used in the clinical diagnosis of AD in Japan. On the other hand, recent application of graph theory to MRI has made it possible to analyze changes in structural connectivity in AD.

  14. Liver isolation in abdominal MRI.

    PubMed

    Rajasvaran, Logeswaran; Haw, Tan Wooi; Sarker, Shakowat Zaman

    2008-08-01

    This work presents a method for liver isolation in magnetic resonance imaging (MRI) abdomen images. It is based on a priori statistical information about the shape of the liver obtained from a training set using the segmentation approach. Morphological watershed algorithm is used as a key technique as it is a simple and intuitive method, producing a complete division of the image in separated regions even if the contrast is poor, and it is fast, with possibility for parallel implementation. To overcome the over-segmentation problem of the watershed process, image preprocessing and postprocessing are applied. Morphological smoothing, Gaussian smoothing, intensity thresholding, gradient computation and gradient thresholding are proposed for preprocessing with morphological and graph based region adjacent list constructed for region merging. A new integrated region similarity function is also defined for region merging control. The proposed method produces good isolation of liver in axial MRI images of the abdomen, as is shown in this paper.

  15. Polycatechol Nanoparticle MRI Contrast Agents.

    PubMed

    Li, Yiwen; Huang, Yuran; Wang, Zhao; Carniato, Fabio; Xie, Yijun; Patterson, Joseph P; Thompson, Matthew P; Andolina, Christopher M; Ditri, Treffly B; Millstone, Jill E; Figueroa, Joshua S; Rinehart, Jeffrey D; Scadeng, Miriam; Botta, Mauro; Gianneschi, Nathan C

    2016-02-01

    Amphiphilic triblock copolymers containing Fe(III) -catecholate complexes formulated as spherical- or cylindrical-shaped micellar nanoparticles (SMN and CMN, respectively) are described as new T1-weighted agents with high relaxivity, low cytotoxicity, and long-term stability in biological fluids. Relaxivities of both SMN and CMN exceed those of established gadolinium chelates across a wide range of magnetic field strengths. Interestingly, shape-dependent behavior is observed in terms of the particles' interactions with HeLa cells, with CMN exhibiting enhanced uptake and contrast via magnetic resonance imaging (MRI) compared with SMN. These results suggest that control over soft nanoparticle shape will provide an avenue for optimization of particle-based contrast agents as biodiagnostics. The polycatechol nanoparticles are proposed as suitable for preclinical investigations into their viability as gadolinium-free, safe, and effective imaging agents for MRI contrast enhancement. PMID:26681255

  16. Clinical outcome after 1 year of cardiac resynchronisation therapy: national results from the European CRT survey.

    PubMed

    Dichtl, Wolfgang; Strohmer, Bernhard; Fruhwald, Friedrich

    2013-12-01

    Cardiac resynchronisation therapy (CRT) is an established treatment option for heart failure patients with electromechanical dyssynchrony. Between 2008 and 2010, the Heart Failure Association (HFA) and the European Heart Rhythm Association (EHRA) of the European Society of Cardiology (ESC) initiated the European CRT survey to describe the current practice and short-term clinical outcome associated with CRT implantations in 13 countries. One year follow-up data from 150 patients collected in 10 Austrian centres are presented in comparison to the total 1,969 patients enrolled throughout Europe. In most cases (n = 120), CRT-D devices were implanted, while CRT-P devices were used in only 23 %. After 12 ± 3 months, mortality and hospitalisation rates reached 10 and 37 %, respectively. New York Heart Association (NYHA) functional classes improved significantly: NYHA I/II/III/IV were found before implantation in 2/20/71/7 % and after 1 year follow-up in 35/51/9/5 % of the patients, respectively. Left ventricular ejection fraction improved from 27 ± 8 % to 35 ± 10 %, left ventricular end-diastolic diameters were reduced from 65 ± 10 mm to 59 ± 5 mm. Median NT-proBNP was reduced from 1,886 to 997 pg/ml, QRS duration diminished from 158 ± 34 to 147 ± 27 ms. In conclusion, the Austrian data from the CRT survey confirms the efficacy of CRT in heart failure patients, but outlines that these patients still suffer from a high mortality and cardiovascular (CV) hospitalisation rate.

  17. A 1-Year Study on the Detection of Human Enteric Viruses in New Caledonia.

    PubMed

    Kaas, Laetitia; Gourinat, Ann-Claire; Urbès, Florence; Langlet, Jérémie

    2016-03-01

    Human enteric viruses occur in high concentrations in wastewater and can contaminate receiving environmental waters. Due to the lack of data on the prevalence of enteric viruses in New Caledonia, the presence and the concentrations of enteric viruses in wastewater and seawater were determined. Untreated wastewater and seawater samples were collected monthly for 1 year from a wastewater treatment plant (WWTP) and from the WWTP's outlet, located directly on a popular recreational beach. Samples were tested for norovirus genogroups I and II (NoV GI and GII), astroviruses (AsV), sapoviruses (SaV), enteroviruses (EV), hepatitis A viruses (HAV), rotaviruses (RoV), human adenoviruses (HAdV) and human polyomaviruses (HPyV). To support these data, faecal samples from cases of gastroenteritis were tested for the first time for NoV and detected in the population. NoV GI, NoV GII, EV, SaV, HAdV and HPyV were detected in all wastewaters, RoV in 75% and AsV in 67%. HAV were not detected in wastewater. Overall, 92% of seawater samples were positive for at least one virus. HPyV were detected most frequently in 92% of samples and at concentrations up to 7.7 × 10(3) genome copies/L. NoV GI, NoV GII, EV, SaV, RoV and HAdV were found in 33, 66, 41, 33, 16 and 66% of seawater samples, respectively. AsV were not detected in seawater. This study reports for the first time the presence of NoV and other enteric viruses in New Caledonia and highlights the year-round presence of enteric viruses in the seawater of a popular beach.

  18. Encouraging responses in sexual and relationship violence prevention: what program effects remain 1 year later?

    PubMed

    Moynihan, Mary M; Banyard, Victoria L; Cares, Alison C; Potter, Sharyn J; Williams, Linda M; Stapleton, Jane G

    2015-01-01

    Colleges and universities are high-risk settings for sexual and relationship violence. To address these problems, institutions of higher education have implemented prevention programs, many of which train students as potential bystanders who can step in to help diffuse risky situations, identify and challenge perpetrators, and assist victims. The impact of bystander sexual and relationship violence prevention programs on long-term behavior of bystanders has remained a key unanswered question for those who seek to offer the most effective programs as well as for policy makers. In this study, the researchers experimentally evaluated the effectiveness of the Bringing in the Bystander® in-person program. Participants were 948 1st-year college students of whom 47.8% were women and 85.2% identified as White (15% also identified as Hispanic in a separate question) between the ages of 18 and 24 at two universities (one a rural, primarily residential campus and the other an urban, highly commuter campus) in the northeastern United States. To date, this is the first study to have found positive behavior changes as long-lasting as 1 year following an educational workshop focusing on engaging bystanders in preventing sexual and relationship violence. Even so, many questions remain to be answered about prevention and intervention of this type. More prospective research is needed on bystander-focused prevention of these forms of violence to help understand and better predict the complicated relationships both between and among the attitudes and behaviors related to preventing sexual and relationship violence. In this regard, we make specific recommendations for designing and evaluating programs based on our findings relating to the importance of moderators, especially two key understudied ones, readiness to help and opportunity to intervene.

  19. Effectiveness of a multidisciplinary heart failure disease management programme on 1-year mortality: Prospective cohort study.

    PubMed

    Laborde-Castérot, Hervé; Agrinier, Nelly; Zannad, Faiez; Mebazaa, Alexandre; Rossignol, Patrick; Girerd, Nicolas; Alla, François; Thilly, Nathalie

    2016-09-01

    We performed a multicenter prospective observational cohort study (Epidémiologie et Pronostic de l'Insuffisance Cardiaque Aiguë en Lorraine, Epidemiology and Prognosis of Acute Heart Failure in Lorraine [EPICAL2]) to evaluate the effectiveness on mortality of a community-based multidisciplinary disease management programme (DMP) for heart failure (HF) patients.Between October 2011 and October 2012, 1816 patients, who were hospitalized for acute HF or who developed acute HF during a hospitalization, were included from 21 hospitals in a northeast region of France. At hospital admission, their mean age was 77.3 (standard deviation [SD] 11.6) years and mean left ventricular ejection fraction was 45.0 (SD 16.0)%. A subset of patients were enrolled in a multidimensional DMP for HF (n = 312, 17.2%), based on structured patient education, home monitoring visits by HF-trained nurses, and automatic alerts triggered by significant clinical and biological changes to the patient. The DMP involved general practitioners, nurses, and cardiologists collaborating via an individual web-based medical electronic record. The outcome was all-cause mortality from the 3rd to the 12th month after discharge. During the follow-up, a total of 377 (20.8%) patients died: 321 (21.3%) in the control group and 56 (17.9%) in the DMP group. In a propensity score analysis, DMP was associated with lower 1-year all-cause mortality (hazard ratio 0.65, 95% CI 0.46-0.92). Instrumental variable analysis gave similar results (hazard ratio 0.56, 0.27-1.16).In a real world setting, a multidimensional DMP for HF with structured patient education, home nurse monitoring, and appropriate physician alerts may improve survival when implemented after discharge from hospitalization due to worsening HF.

  20. Effect of ethnicity on weight loss among adolescents 1 year after bariatric surgery

    PubMed Central

    Messiah, Sarah E; Lopez-Mitnik, Gabriela; Winegar, Deborah; Sherif, Bintu; Arheart, Kristopher L; Reichard, Kirk W; Michalsky, Marc P; Lipshultz, Steven E; Miller, Tracie L; Livingstone, Alan S; de la Cruz-Muñoz, Nestor

    2013-01-01

    AIM: To investigate whether or not bariatric surgery weight outcomes vary by ethnicity in a large, nationally representative sample of adolescents. METHODS: The Bariatric Outcomes Longitudinal Database was used for analysis and contains data on surgeries performed on adolescents from 2004 to 2010 from 423 surgeons at 360 facilities across the United States Adolescents (n = 827) between 11 and 19 years old who underwent either gastric bypass or adjustable gastric banding surgery were included in the analysis. Outcome measures included changes in anthropometric measurements [weight (kg) and body mass index] from baseline to 3 (n = 739), 6 (n = 512), and 12 (n = 247) mo after surgery. RESULTS: A year after patients underwent either gastric bypass (51%) or adjustable gastric banding (49%) surgery, mean estimated weight loss for all ethnic groups differed by a maximum of only 1.5 kg, being 34.3 kg (95%CI: 30.0-38.5 kg) for Hispanics, 33.8 kg (95%CI: 27.3-40.3 kg) for non-Hispanic blacks, and 32.8 kg (95%CI: 30.9-34.7 kg) for non-Hispanic whites. No overall pairwise group comparisons were significant, indicating that no ethnic group had better weight loss outcomes than did another. CONCLUSION: Bariatric surgery substantially reduces the weight of severely obese adolescents at 1 year post-procedure with little variation by ethnicity and/or gender. These results suggest that bariatric surgery is a safe and reasonable treatment for all severely obese adolescents with the appropriate indications. PMID:24147204

  1. A 1-Year Study on the Detection of Human Enteric Viruses in New Caledonia.

    PubMed

    Kaas, Laetitia; Gourinat, Ann-Claire; Urbès, Florence; Langlet, Jérémie

    2016-03-01

    Human enteric viruses occur in high concentrations in wastewater and can contaminate receiving environmental waters. Due to the lack of data on the prevalence of enteric viruses in New Caledonia, the presence and the concentrations of enteric viruses in wastewater and seawater were determined. Untreated wastewater and seawater samples were collected monthly for 1 year from a wastewater treatment plant (WWTP) and from the WWTP's outlet, located directly on a popular recreational beach. Samples were tested for norovirus genogroups I and II (NoV GI and GII), astroviruses (AsV), sapoviruses (SaV), enteroviruses (EV), hepatitis A viruses (HAV), rotaviruses (RoV), human adenoviruses (HAdV) and human polyomaviruses (HPyV). To support these data, faecal samples from cases of gastroenteritis were tested for the first time for NoV and detected in the population. NoV GI, NoV GII, EV, SaV, HAdV and HPyV were detected in all wastewaters, RoV in 75% and AsV in 67%. HAV were not detected in wastewater. Overall, 92% of seawater samples were positive for at least one virus. HPyV were detected most frequently in 92% of samples and at concentrations up to 7.7 × 10(3) genome copies/L. NoV GI, NoV GII, EV, SaV, RoV and HAdV were found in 33, 66, 41, 33, 16 and 66% of seawater samples, respectively. AsV were not detected in seawater. This study reports for the first time the presence of NoV and other enteric viruses in New Caledonia and highlights the year-round presence of enteric viruses in the seawater of a popular beach. PMID:26670603

  2. Robot-assisted laparoscopic pyeloplasty: minimum 1-year follow-up

    NASA Astrophysics Data System (ADS)

    Patel, Vipul; Thaly, Rahul; Shah, Ketul

    2007-02-01

    Objectives: To evaluate the feasibility and efficacy of robotic-assisted laparoscopic pyeloplasty. Laparoscopic pyeloplasty has been shown to have a success rate comparable to that of the open surgical approach. However, the steep learning curve has hindered its acceptance into mainstream urologic practice. The introduction of robotic assistance provides advantages that have the potential to facilitate precise dissection and intracorporeal suturing. Methods: A total of 50 patients underwent robotic-assisted laparoscopic dismembered pyeloplasty. A four-trocar technique was used. Most patients were discharged home on day 1, with stent removal at 3 weeks. Patency of the ureteropelvic junction was assessed in all patients with mercaptotriglycylglycine Lasix renograms at 1, 3, 6, 9, and 12 months, then every 6 months for 1 year, and then yearly. Results: Each patient underwent a successful procedure without open conversion or transfusion. The average estimated blood loss was 40 ml. The operative time averaged 122 minutes (range 60 to 330) overall. Crossing vessels were present in 30% of the patients and were preserved in all cases. The time for the anastomosis averaged 20 minutes (range 10 to 100). Intraoperatively, no complications occurred. Postoperatively, the average hospital stay was 1.1 days. The stents were removed at an average of 20 days (range 14 to 28) postoperatively. The average follow-up was 11.7 months; at the last follow-up visit, each patient was doing well. Of the 50 patients, 48 underwent one or more renograms, demonstrating stable renal function, improved drainage, and no evidence of recurrent obstruction. Conclusions: Robotic-assisted laparoscopic pyeloplasty is a feasible technique for ureteropelvic junction reconstruction. The procedure provides a minimally invasive alternative with good short-term results.

  3. Effectiveness of a multidisciplinary heart failure disease management programme on 1-year mortality: Prospective cohort study.

    PubMed

    Laborde-Castérot, Hervé; Agrinier, Nelly; Zannad, Faiez; Mebazaa, Alexandre; Rossignol, Patrick; Girerd, Nicolas; Alla, François; Thilly, Nathalie

    2016-09-01

    We performed a multicenter prospective observational cohort study (Epidémiologie et Pronostic de l'Insuffisance Cardiaque Aiguë en Lorraine, Epidemiology and Prognosis of Acute Heart Failure in Lorraine [EPICAL2]) to evaluate the effectiveness on mortality of a community-based multidisciplinary disease management programme (DMP) for heart failure (HF) patients.Between October 2011 and October 2012, 1816 patients, who were hospitalized for acute HF or who developed acute HF during a hospitalization, were included from 21 hospitals in a northeast region of France. At hospital admission, their mean age was 77.3 (standard deviation [SD] 11.6) years and mean left ventricular ejection fraction was 45.0 (SD 16.0)%. A subset of patients were enrolled in a multidimensional DMP for HF (n = 312, 17.2%), based on structured patient education, home monitoring visits by HF-trained nurses, and automatic alerts triggered by significant clinical and biological changes to the patient. The DMP involved general practitioners, nurses, and cardiologists collaborating via an individual web-based medical electronic record. The outcome was all-cause mortality from the 3rd to the 12th month after discharge. During the follow-up, a total of 377 (20.8%) patients died: 321 (21.3%) in the control group and 56 (17.9%) in the DMP group. In a propensity score analysis, DMP was associated with lower 1-year all-cause mortality (hazard ratio 0.65, 95% CI 0.46-0.92). Instrumental variable analysis gave similar results (hazard ratio 0.56, 0.27-1.16).In a real world setting, a multidimensional DMP for HF with structured patient education, home nurse monitoring, and appropriate physician alerts may improve survival when implemented after discharge from hospitalization due to worsening HF. PMID:27631204

  4. Aerosol source apportionment from 1-year measurements at the CESAR tower in Cabauw, the Netherlands

    NASA Astrophysics Data System (ADS)

    Schlag, Patrick; Kiendler-Scharr, Astrid; Blom, Marcus Johannes; Canonaco, Francesco; Sebastiaan Henzing, Jeroen; Moerman, Marcel; Prévôt, André Stephan Henry; Holzinger, Rupert

    2016-07-01

    Intensive measurements of submicron aerosol particles and their chemical composition were performed with an Aerosol Chemical Speciation Monitor (ACSM) at the Cabauw Experimental Site for Atmospheric Research (CESAR) in Cabauw, the Netherlands, sampling at 5 m height above ground. The campaign lasted nearly 1 year from July 2012 to June 2013 as part of the EU-FP7-ACTRIS project (Q-ACSM Network). Including equivalent black carbon an average particulate mass concentration of 9.50 µg m-3 was obtained during the whole campaign with dominant contributions from ammonium nitrate (45 %), organic aerosol (OA, 29 %), and ammonium sulfate (19 %). There were 12 exceedances of the World Health Organization (WHO) PM2.5 daily mean limit (25 µg m-3) observed at this rural site using PM1 instrumentation only. Ammonium nitrate and OA represented the largest contributors to total particulate matter during periods of exceedance. Source apportionment of OA was performed season-wise by positive matrix factorization (PMF) using the multilinear engine 2 (ME-2) controlled via the source finder (SoFi). Primary organic aerosols were attributed mainly to traffic (8-16 % contribution to total OA, averaged season-wise) and biomass burning (0-23 %). Secondary organic aerosols (SOAs, 61-84 %) dominated the organic fraction during the whole campaign, particularly on days with high mass loadings. A SOA factor which is attributed to humic-like substances (HULIS) was identified as a highly oxidized background aerosol in Cabauw. This shows the importance of atmospheric aging processes for aerosol concentration at this rural site. Due to the large secondary fraction, the reduction of particulate mass at this rural site is challenging on a local scale.

  5. Deep Sclerectomy With a New Nonabsorbable Uveoscleral Implant (Esnoper-Clip): 1-Year Outcomes

    PubMed Central

    Parera-Arranz, Angels; Romera-Romera, Pau; Castellvi-Manent, Jordi; Sabala-Llopart, Antoni; de la Cámara-Hermoso, Julio

    2015-01-01

    Purpose: To report the safety and the effectiveness of deep sclerectomy (DS) with a new nonabsorbable uveoscleral hema implant (Esnoper-Clip) designed to increase trabecular and uveoscleral outflow and to achieve higher intrascleral blebs. Materials and Methods: Twenty-seven eyes of 27 patients with open-angle glaucoma, who underwent DS with an Esnoper-Clip implant, were included in this study. All patients were followed up after 12 months. Results: A significant decrease in intraocular pressure was observed after surgery, changing from a preoperative mean of 26.6±5.2 mm Hg to a postoperative mean of 15.3±5 mm Hg (P<0.001) at 12 months. There was also a significant reduction in the number of glaucoma drugs needed, varying from 2.5 per patient to 0.3 (P<0.001) 1 year after surgery. The main intrascleral lake height and volume at 12 months was 0.7±0.1 mm and 3.9±1.3 mm3, respectively. No intraoperative complications occurred. The main postoperative complications were a positive Seidel test result at 24 hours in 2 eyes (7.4%), hyphema in 2 eyes (7.4%), and choroidal detachment in 1 eye (3.7%). All these complications resolved successfully. The need for additional mitomycin-C injections was recorded in 4 eyes (14.8%), twice in 2 of them. Twelve eyes (44.4%) underwent postsurgical Nd:YAG laser goniopuncture with a mean time between surgery and this procedure of 4.3 months. Mean intraocular pressure after Nd:YAG laser goniopuncture decreased from 19.2 to 15.5 mm Hg (P<0.001). Conclusion: DS with an uveoscleral hema implant (Esnoper-Clip) is a safe and effective technique for the management of open-angle glaucoma. PMID:25836660

  6. Parallel MRI at microtesla fields.

    PubMed

    Zotev, Vadim S; Volegov, Petr L; Matlashov, Andrei N; Espy, Michelle A; Mosher, John C; Kraus, Robert H

    2008-06-01

    Parallel imaging techniques have been widely used in high-field magnetic resonance imaging (MRI). Multiple receiver coils have been shown to improve image quality and allow accelerated image acquisition. Magnetic resonance imaging at ultra-low fields (ULF MRI) is a new imaging approach that uses SQUID (superconducting quantum interference device) sensors to measure the spatially encoded precession of pre-polarized nuclear spin populations at microtesla-range measurement fields. In this work, parallel imaging at microtesla fields is systematically studied for the first time. A seven-channel SQUID system, designed for both ULF MRI and magnetoencephalography (MEG), is used to acquire 3D images of a human hand, as well as 2D images of a large water phantom. The imaging is performed at 46 mu T measurement field with pre-polarization at 40 mT. It is shown how the use of seven channels increases imaging field of view and improves signal-to-noise ratio for the hand images. A simple procedure for approximate correction of concomitant gradient artifacts is described. Noise propagation is analyzed experimentally, and the main source of correlated noise is identified. Accelerated imaging based on one-dimensional undersampling and 1D SENSE (sensitivity encoding) image reconstruction is studied in the case of the 2D phantom. Actual threefold imaging acceleration in comparison to single-average fully encoded Fourier imaging is demonstrated. These results show that parallel imaging methods are efficient in ULF MRI, and that imaging performance of SQUID-based instruments improves substantially as the number of channels is increased.

  7. Parallel MRI at microtesla fields

    NASA Astrophysics Data System (ADS)

    Zotev, Vadim S.; Volegov, Petr L.; Matlashov, Andrei N.; Espy, Michelle A.; Mosher, John C.; Kraus, Robert H.

    2008-06-01

    Parallel imaging techniques have been widely used in high-field magnetic resonance imaging (MRI). Multiple receiver coils have been shown to improve image quality and allow accelerated image acquisition. Magnetic resonance imaging at ultra-low fields (ULF MRI) is a new imaging approach that uses SQUID (superconducting quantum interference device) sensors to measure the spatially encoded precession of pre-polarized nuclear spin populations at microtesla-range measurement fields. In this work, parallel imaging at microtesla fields is systematically studied for the first time. A seven-channel SQUID system, designed for both ULF MRI and magnetoencephalography (MEG), is used to acquire 3D images of a human hand, as well as 2D images of a large water phantom. The imaging is performed at 46 μT measurement field with pre-polarization at 40 mT. It is shown how the use of seven channels increases imaging field of view and improves signal-to-noise ratio for the hand images. A simple procedure for approximate correction of concomitant gradient artifacts is described. Noise propagation is analyzed experimentally, and the main source of correlated noise is identified. Accelerated imaging based on one-dimensional undersampling and 1D SENSE (sensitivity encoding) image reconstruction is studied in the case of the 2D phantom. Actual threefold imaging acceleration in comparison to single-average fully encoded Fourier imaging is demonstrated. These results show that parallel imaging methods are efficient in ULF MRI, and that imaging performance of SQUID-based instruments improves substantially as the number of channels is increased.

  8. Retroperitoneal bronchogenic cyst: MRI findings.

    PubMed

    Castro, R; Oliveira, M I; Fernandes, T; Madureira, A J

    2013-01-01

    The authors describe a case of a retroperitoneal bronchogenic cyst in a 36-year-old female. She presented with abdominal pain, nausea, and vomiting. An MRI scan revealed an 8 cm cystic lesion in the left upper retroperitoneum, with intermediate signal on T2-weighted images, high signal on T1 weighted images, and lack of internal enhancement after gadolinium. After laparoscopic excision, the histology findings were compatible with a bronchogenic cyst, which is extremely uncommon in the retroperitoneum.

  9. Quantitative MRI Assessment of Leukoencephalopathy

    PubMed Central

    Reddick, Wilburn E.; Glass, John O.; Langston, James W.; Helton, Kathleen J.

    2008-01-01

    Quantitative MRI assessment of leukoencephalopathy is difficult because the MRI properties of leukoencephalopathy significantly overlap those of normal tissue. This report describes the use of an automated procedure for longitudinal measurement of tissue volume and relaxation times to quantify leukoencephalopathy. Images derived by using this procedure in patients undergoing therapy for acute lymphoblastic leukemia (ALL) are presented. Five examinations from each of five volunteers (25 examinations) were used to test the reproducibility of quantitated baseline and subsequent, normal-appearing images; the coefficients of variation were less than 2% for gray and white matter. Regions of leukoencephalopathy in patients were assessed by comparison with manual segmentation. Two radiologists manually segmented images from 15 randomly chosen MRI examinations that exhibited leukoencephalopathy. Kappa analyses showed that the two radiologists’ interpretations were concordant (κ = 0.70) and that each radiologist’s interpretations agreed with the results of the automated procedure (κ = 0.57 and 0.55).The clinical application of this method was illustrated by analysis of images from sequential MR examinations of two patients who developed leukoencephalopathy during treatment for ALL. The ultimate goal is to use these quantitative MR imaging measures to better understand therapy-induced neurotoxicity, which can be limited or even reversed with some combination of therapy adjustments and pharmacological and neurobehavioral interventions. PMID:11979570

  10. MRI characteristics of midbrain tumours.

    PubMed

    Sun, B; Wang, C C; Wang, J

    1999-03-01

    We diagnosed 60 cases of midbrain tumours by MRI between 1993 to 1997. There were 39 males and 21 females, aged 2-64 years, mean 25.6 years. We found 38 patients with true intramedullary mid-brain tumours, 11 predominantly in the tectum, 20 in the tegmentum and 7 with a downward extension to the pons; there were 7 within the cerebral aqueduct. There were 22 patients with infiltrating midbrain tumours extending from adjacent structures, 11 cases each from the thalamus and pineal region. All patients received surgical treatment. Gross total resection was achieved in 42 cases, subtotal (> 75 %) resection in 18. Pathological diagnoses included 16 low-grade and 15 high-grade astrocytomas; 5 oligodendroastrocytomas; 2 ependymomas; 11 glioblastomas; and 11 pineal parenchymal or germ-cell tumours. Midbrain tumours are a heterogeneous group of neoplasms, with wide variation in clinical and MRI features, related to the site and type of tumour. MRI not only allows precise analysis of their growth pattern, but also can lead to a correct preoperative diagnosis in the majority of cases.

  11. Characteristic MRI Findings of upper Limb Muscle Involvement in Myotonic Dystrophy Type 1

    PubMed Central

    Sugie, Kazuma; Sugie, Miho; Taoka, Toshio; Tonomura, Yasuyo; Kumazawa, Aya; Izumi, Tesseki; Kichikawa, Kimihiko; Ueno, Satoshi

    2015-01-01

    The objective of our study was to evaluate the relation between muscle MRI findings and upper limb weakness with grip myotonia in patients with myotonic dystrophy type 1 (DM1). Seventeen patients with DM1 were evaluated by manual muscle strength testing and muscle MRI of the upper limbs. Many DM1 patients presenting with decreased grasping power frequently showed high intensity signals in the flexor digitorum profundus (FDP) muscles on T1-weighted imaging. Patients presenting with upper limb weakness frequently also showed high intensity signals in the flexor pollicis longus, abductor pollicis longus, and extensor pollicis muscles. Disturbances of the distal muscles of the upper limbs were predominant in all DM1 patients. Some DM1 patients with a prolonged disease duration showed involvement of not only distal muscles but also proximal muscles in the upper limbs. Muscle involvement of the upper limbs on MRI strongly correlated positively with the disease duration or the numbers of CTG repeats. To our knowledge, this is the first study to provide a detailed description of the distribution and severity of affected muscles of the upper limbs on MRI in patients with DM1. We conclude that muscle MRI findings are very useful for identifying affected muscles and predicting the risk of muscle weakness in the upper limbs of DM1 patients. PMID:25919300

  12. Native DNA repeats and methylation in Ascobolus.

    PubMed Central

    Goyon, C; Rossignol, J L; Faugeron, G

    1996-01-01

    We identified two classes of native dispersed DNA repeats in the Ascobolus genome. The first class consisted of several kilobase long, methylated repeats. These repeats, named Mars (methylated Ascobolus repeated sequences), fell in one family of LINE-like elements and in three families of LTR-containing retrotransposable elements. The methylation features of Mars elements were those expected if they were natural targets for the MIP (methylation induced premeiotically) previously discovered in Ascobolus. The second class consisted of short repeats, approximately 100 bp long, corresponding to 5S rRNA and tRNA genes. As expected from their size, which was too small to allow MIP to occur, they were unmethylated, as were 26 kb of unique sequences tested. These observations are consistent with the hypothesis that MIP is targeted at natural DNA repeats and constitutes a defensive process against the detrimental consequences of the spreading of mobile elements throughout the genome. The 9 kb tandem repeats harbouring the 28S, 18S and 5.8S rRNA genes displayed methylation features suggesting that rDNA methylation proceeds through a process other than MIP. PMID:8811089

  13. Finding and Characterizing Repeats in Plant Genomes.

    PubMed

    Nicolas, Jacques; Peterlongo, Pierre; Tempel, Sébastien

    2016-01-01

    Plant genomes contain a particularly high proportion of repeated structures of various types. This chapter proposes a guided tour of available software that can help biologists to look for these repeats and check some hypothetical models intended to characterize their structures. Since transposable elements are a major source of repeats in plants, many methods have been used or developed for this large class of sequences. They are representative of the range of tools available for other classes of repeats and we have provided a whole section on this topic as well as a selection of the main existing software. In order to better understand how they work and how repeats may be efficiently found in genomes, it is necessary to look at the technical issues involved in the large-scale search of these structures. Indeed, it may be hard to keep up with the profusion of proposals in this dynamic field and the rest of the chapter is devoted to the foundations of the search for repeats and more complex patterns. The second section introduces the key concepts that are useful for understanding the current state of the art in playing with words, applied to genomic sequences. This can be seen as the first stage of a very general approach called linguistic analysis that is interested in the analysis of natural or artificial texts. Words, the lexical level, correspond to simple repeated entities in texts or strings. In fact, biologists need to represent more complex entities where a repeat family is built on more abstract structures, including direct or inverted small repeats, motifs, composition constraints as well as ordering and distance constraints between these elementary blocks. In terms of linguistics, this corresponds to the syntactic level of a language. The last section introduces concepts and practical tools that can be used to reach this syntactic level in biological sequence analysis. PMID:26519414

  14. Finding and Characterizing Repeats in Plant Genomes.

    PubMed

    Nicolas, Jacques; Peterlongo, Pierre; Tempel, Sébastien

    2016-01-01

    Plant genomes contain a particularly high proportion of repeated structures of various types. This chapter proposes a guided tour of available software that can help biologists to look for these repeats and check some hypothetical models intended to characterize their structures. Since transposable elements are a major source of repeats in plants, many methods have been used or developed for this large class of sequences. They are representative of the range of tools available for other classes of repeats and we have provided a whole section on this topic as well as a selection of the main existing software. In order to better understand how they work and how repeats may be efficiently found in genomes, it is necessary to look at the technical issues involved in the large-scale search of these structures. Indeed, it may be hard to keep up with the profusion of proposals in this dynamic field and the rest of the chapter is devoted to the foundations of the search for repeats and more complex patterns. The second section introduces the key concepts that are useful for understanding the current state of the art in playing with words, applied to genomic sequences. This can be seen as the first stage of a very general approach called linguistic analysis that is interested in the analysis of natural or artificial texts. Words, the lexical level, correspond to simple repeated entities in texts or strings. In fact, biologists need to represent more complex entities where a repeat family is built on more abstract structures, including direct or inverted small repeats, motifs, composition constraints as well as ordering and distance constraints between these elementary blocks. In terms of linguistics, this corresponds to the syntactic level of a language. The last section introduces concepts and practical tools that can be used to reach this syntactic level in biological sequence analysis.

  15. A novel anthropomorphic flow phantom for the quantitative evaluation of prostate DCE-MRI acquisition techniques

    NASA Astrophysics Data System (ADS)

    Knight, Silvin P.; Browne, Jacinta E.; Meaney, James F.; Smith, David S.; Fagan, Andrew J.

    2016-10-01

    A novel anthropomorphic flow phantom device has been developed, which can be used for quantitatively assessing the ability of magnetic resonance imaging (MRI) scanners to accurately measure signal/concentration time-intensity curves (CTCs) associated with dynamic contrast-enhanced (DCE) MRI. Modelling of the complex pharmacokinetics of contrast agents as they perfuse through the tumour capillary network has shown great promise for cancer diagnosis and therapy monitoring. However, clinical adoption has been hindered by methodological problems, resulting in a lack of consensus regarding the most appropriate acquisition and modelling methodology to use and a consequent wide discrepancy in published data. A heretofore overlooked source of such discrepancy may arise from measurement errors of tumour CTCs deriving from the imaging pulse sequence itself, while the effects on the fidelity of CTC measurement of using rapidly-accelerated sequences such as parallel imaging and compressed sensing remain unknown. The present work aimed to investigate these features by developing a test device in which ‘ground truth’ CTCs were generated and presented to the MRI scanner for measurement, thereby allowing for an assessment of the DCE-MRI protocol to accurately measure this curve shape. The device comprised a four-pump flow system wherein CTCs derived from prior patient prostate data were produced in measurement chambers placed within the imaged volume. The ground truth was determined as the mean of repeat measurements using an MRI-independent, custom-built optical imaging system. In DCE-MRI experiments, significant discrepancies between the ground truth and measured CTCs were found for both tumorous and healthy tissue-mimicking curve shapes. Pharmacokinetic modelling revealed errors in measured K trans, v e and k ep values of up to 42%, 31%, and 50% respectively, following a simple variation of the parallel imaging factor and number of signal averages in the acquisition

  16. The child accident repeater: a review.

    PubMed

    Jones, J G

    1980-04-01

    The child accident repeater is defined as one who has at least three accidents that come to medical attention within a year. The accident situation has features in common with those of the child who has a single accident through simple "bad luck", but other factors predispose him to repeated injury. In the child who has a susceptible personality, a tendency for accident repetition may be due to a breakdown in adjustment to a stressful environment. Prevention of repeat accidents should involve the usual measures considered appropriate for all children as well as an attempt to provide treatment of significant maladjustment and modification of a stressful environment.

  17. Do gamma-ray burst sources repeat?

    NASA Technical Reports Server (NTRS)

    Meegan, C. A.; Hartmann, D. H.; Brainerd, J. J.; Briggs, M.; Paciesas, W. S.; Pendleton, G.; Kouveliotou, C.; Fishman, G.; Blumenthal, G.; Brock, M.

    1994-01-01

    The demonstration of repeated gamma-ray bursts from an individual source would severely constrain burst source models. Recent reports of evidence for repetition in the first BATSE burst catalog have generated renewed interest in this issue. Here, we analyze the angular distribution of 585 bursts of the second BATSE catalog (Meegan et al. 1994). We search for evidence of burst recurrence using the nearest and farthest neighbor statistic ad the two-point angular correlation function. We find the data to be consistent with the hypothesis that burst sources do not repeat; however, a repeater fraction of up to about 20% of the bursts cannot be excluded.

  18. Brain development in preterm infants assessed using advanced MRI techniques.

    PubMed

    Tusor, Nora; Arichi, Tomoki; Counsell, Serena J; Edwards, A David

    2014-03-01

    Infants who are born preterm have a high incidence of neurocognitive and neurobehavioral abnormalities, which may be associated with impaired brain development. Advanced magnetic resonance imaging (MRI) approaches, such as diffusion MRI (d-MRI) and functional MRI (fMRI), provide objective and reproducible measures of brain development. Indices derived from d-MRI can be used to provide quantitative measures of preterm brain injury. Although fMRI of the neonatal brain is currently a research tool, future studies combining d-MRI and fMRI have the potential to assess the structural and functional properties of the developing brain and its response to injury.

  19. Surveillance of antimicrobial resistance among Escherichia coli in wastewater in Stockholm during 1 year: does it reflect the resistance trends in the society?

    PubMed

    Kwak, Young-Keun; Colque, Patricia; Byfors, Sara; Giske, Christian G; Möllby, Roland; Kühn, Inger

    2015-01-01

    The resistance patterns of Escherichia coli in untreated (raw) urban wastewater (UW) was monitored by repeated sampling during 1 year. Comparison with data from wastewater samples collected from hospital wastewater (HW) in the same urban area was made. A total of 1326 E. coli isolates from 17 UW samples and 451 isolates from six HW samples were analysed by typing using the PhenePlate™ system, and their susceptibility towards 10 antibiotics was determined. Resistance to at least one antibiotic was observed in 34% of the UW isolates and 55% of the HW isolates. For UW isolates, phenotypic diversity was lower among antibiotic-susceptible than among antibiotic-resistant isolates, indicating a higher presence of clonal groups among susceptible isolates. Total antibiotic resistance measured as the Multiple Antibiotic Resistance (MAR) index was 0.08 for UW compared with 0.19 for HW, and increased over time for UW isolates, indicating increasing resistance among E. coli in the urban population during the studied time period. Resistance to all included β-lactam antibiotics was detected in 2.4% of UW isolates and 14.0% of HW isolates, and 73/75 (97%) analysed isolates were confirmed to be extended-spectrum β-lactamase (including plasmid-mediated AmpC)-producing E. coli. Thus, by cultivating samples from wastewater and analysing many independent isolates per sample, increasing frequencies of antibiotic resistance in UW were detected during 1 year that may reflect increasing faecal carriage of resistant bacteria in the society. Surveillance of antibiotic resistance in wastewater could be a valuable tool for screening of resistance trends on a population level.

  20. Maleimidyl magnetic nanoplatform for facile molecular MRI

    NASA Astrophysics Data System (ADS)

    Heo, Dan; Lee, Eugene; Ku, Minhee; Hwang, Seungyeon; Kim, Bongjune; Park, Yeonji; Lee, Young Han; Huh, Yong-Min; Haam, Seungjoo; Cheong, Jae-Ho; Yang, Jaemoon; Suh, Jin-Suck

    2014-07-01

    In this study, we developed the maleimidyl magnetic nanoplatform, which enables functional targeting of a biomarker-specific moiety for molecular imaging via MRI. The maleimide group of the maleimidyl magnetic nanoplatform is conjugated with a thiol group without additional crosslinkers and side products. A physicochemical analysis was conducted to verify the effectiveness of the maleimidyl magnetic nanoplatform, and the existence of the maleimidyl group was investigated using the platform. To prepare biomarker-specific MRI probes, a thiolated aptamer and peptide were immobilized onto the maleimidyl group of the maleimidyl magnetic nanoplatform. The fabricated MRI probes were applied to four cancer cell lines: HT1080, MCF7, MKN45, and HEK293T. To investigate the potential of the molecular MRI probe, the target-biomarker specificity was confirmed without serious cytotoxicity, and in vivo MRI analysis using a xenograft mouse model was demonstrated. We believe these results will be useful for fabricating molecular MRI probes for the diagnosis of cancer.

  1. MRI Scans - Multiple Languages: MedlinePlus

    MedlinePlus

    ... Resonance Imaging) (Arabic) العربية Bilingual PDF Health Information Translations Chinese - Simplified (简体中文) MRI (Magnetic Resonance Imaging) 核磁共振成像(MRI) - 简体中文 (Chinese - Simplified) Bilingual PDF Health Information Translations Chinese - Traditional (繁體中文) MRI (Magnetic Resonance Imaging) 核磁共振成像( ...

  2. DNA Triplet Repeat Expansion and Mismatch Repair

    PubMed Central

    Iyer, Ravi R.; Pluciennik, Anna; Napierala, Marek; Wells, Robert D.

    2016-01-01

    DNA mismatch repair is a conserved antimutagenic pathway that maintains genomic stability through rectification of DNA replication errors and attenuation of chromosomal rearrangements. Paradoxically, mutagenic action of mismatch repair has been implicated as a cause of triplet repeat expansions that cause neurological diseases such as Huntington disease and myotonic dystrophy. This mutagenic process requires the mismatch recognition factor MutSβ and the MutLα (and/or possibly MutLγ) endonuclease, and is thought to be triggered by the transient formation of unusual DNA structures within the expanded triplet repeat element. This review summarizes the current knowledge of DNA mismatch repair involvement in triplet repeat expansion, which encompasses in vitro biochemical findings, cellular studies, and various in vivo transgenic animal model experiments. We present current mechanistic hypotheses regarding mismatch repair protein function in mediating triplet repeat expansions and discuss potential therapeutic approaches targeting the mismatch repair pathway. PMID:25580529

  3. The Moral Maturity of Repeater Delinquents.

    ERIC Educational Resources Information Center

    Petronio, Richard J.

    1980-01-01

    Differences in moral development (as conceived by Kohlberg) were examined in a sample of delinquent teenagers. The repeater group was not found, as had been hypothesized, to be lower on moral maturity than those who engaged in less delinquency. (GC)

  4. Hepatobiliary MRI: current concepts and controversies.

    PubMed

    Glockner, James F

    2007-04-01

    Evaluation of the liver and biliary system is a frequent indication for abdominal MRI. Hepatobiliary MRI comprises a set of noninvasive techniques that are usually very effective in answering most clinical questions. There are significant limitations, however, as well as considerable variation and disagreement regarding the optimal protocols for standard hepatic MRI and magnetic resonance cholangiopancreaticography (MRCP). This review discusses pulse sequences most often used in hepatic MRI and MRCP, examines a few sources of controversy in the current literature, and summarizes some recent and future developments in the field.

  5. Functional MRI and Outcome in Traumatic Coma

    PubMed Central

    Giacino, Joseph T.; Wu, Ona

    2013-01-01

    Advances in task-based functional MRI (fMRI), resting-state fMRI (rs-fMRI), and arterial-spin labeled (ASL) perfusion MRI have occurred at a rapid pace in recent years. These techniques for measuring brain function have great potential to improve the accuracy of prognostication for civilian and military patients with traumatic coma. In addition, fMRI, rs-fMRI, and ASL have provided novel insights into the pathophysiology of traumatic disorders of consciousness, as well as mechanisms of recovery from coma. However, functional neuroimaging techniques have yet to achieve widespread clinical use as prognostic tests for patients with traumatic coma. Rather, a broad spectrum of methodological hurdles currently limits the feasibility of clinical implementation. In this review, we discuss the basic principles of fMRI, rs-fMRI and ASL and their potential applications as prognostic tools for patients with traumatic coma. We also discuss future strategies for overcoming the current barriers to clinical implementation. PMID:23881623

  6. Star repeaters for fiber optic links.

    PubMed

    McMahon, D H; Gravel, R L

    1977-02-01

    A star repeater combines the functions of a passive star coupler and a signal regenerating amplifier. By more effectively utilizing the light power radiated by a light emitting diode, the star repeater can, when used with small diameter channels, couple as much power to all receivers of a multiterminal link as would be coupled to the single receiver of a simple point-to-point link.

  7. Development of 1-year-old computational phantom and calculation of organ doses during CT scans using Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Pan, Yuxi; Qiu, Rui; Gao, Linfeng; Ge, Chaoyong; Zheng, Junzheng; Xie, Wenzhang; Li, Junli

    2014-09-01

    With the rapidly growing number of CT examinations, the consequential radiation risk has aroused more and more attention. The average dose in each organ during CT scans can only be obtained by using Monte Carlo simulation with computational phantoms. Since children tend to have higher radiation sensitivity than adults, the radiation dose of pediatric CT examinations requires special attention and needs to be assessed accurately. So far, studies on organ doses from CT exposures for pediatric patients are still limited. In this work, a 1-year-old computational phantom was constructed. The body contour was obtained from the CT images of a 1-year-old physical phantom and the internal organs were deformed from an existing Chinese reference adult phantom. To ensure the organ locations in the 1-year-old computational phantom were consistent with those of the physical phantom, the organ locations in 1-year-old computational phantom were manually adjusted one by one, and the organ masses were adjusted to the corresponding Chinese reference values. Moreover, a CT scanner model was developed using the Monte Carlo technique and the 1-year-old computational phantom was applied to estimate organ doses derived from simulated CT exposures. As a result, a database including doses to 36 organs and tissues from 47 single axial scans was built. It has been verified by calculation that doses of axial scans are close to those of helical scans; therefore, this database could be applied to helical scans as well. Organ doses were calculated using the database and compared with those obtained from the measurements made in the physical phantom for helical scans. The differences between simulation and measurement were less than 25% for all organs. The result shows that the 1-year-old phantom developed in this work can be used to calculate organ doses in CT exposures, and the dose database provides a method for the estimation of 1-year-old patient doses in a variety of CT examinations.

  8. Development of 1-year-old computational phantom and calculation of organ doses during CT scans using Monte Carlo simulation.

    PubMed

    Pan, Yuxi; Qiu, Rui; Gao, Linfeng; Ge, Chaoyong; Zheng, Junzheng; Xie, Wenzhang; Li, Junli

    2014-09-21

    With the rapidly growing number of CT examinations, the consequential radiation risk has aroused more and more attention. The average dose in each organ during CT scans can only be obtained by using Monte Carlo simulation with computational phantoms. Since children tend to have higher radiation sensitivity than adults, the radiation dose of pediatric CT examinations requires special attention and needs to be assessed accurately. So far, studies on organ doses from CT exposures for pediatric patients are still limited. In this work, a 1-year-old computational phantom was constructed. The body contour was obtained from the CT images of a 1-year-old physical phantom and the internal organs were deformed from an existing Chinese reference adult phantom. To ensure the organ locations in the 1-year-old computational phantom were consistent with those of the physical phantom, the organ locations in 1-year-old computational phantom were manually adjusted one by one, and the organ masses were adjusted to the corresponding Chinese reference values. Moreover, a CT scanner model was developed using the Monte Carlo technique and the 1-year-old computational phantom was applied to estimate organ doses derived from simulated CT exposures. As a result, a database including doses to 36 organs and tissues from 47 single axial scans was built. It has been verified by calculation that doses of axial scans are close to those of helical scans; therefore, this database could be applied to helical scans as well. Organ doses were calculated using the database and compared with those obtained from the measurements made in the physical phantom for helical scans. The differences between simulation and measurement were less than 25% for all organs. The result shows that the 1-year-old phantom developed in this work can be used to calculate organ doses in CT exposures, and the dose database provides a method for the estimation of 1-year-old patient doses in a variety of CT examinations.

  9. Digital repeat analysis; setup and operation.

    PubMed

    Nol, J; Isouard, G; Mirecki, J

    2006-06-01

    Since the emergence of digital imaging, there have been questions about the necessity of continuing reject analysis programs in imaging departments to evaluate performance and quality. As a marketing strategy, most suppliers of digital technology focus on the supremacy of the technology and its ability to reduce the number of repeats, resulting in less radiation doses given to patients and increased productivity in the department. On the other hand, quality assurance radiographers and radiologists believe that repeats are mainly related to positioning skills, and repeat analysis is the main tool to plan training needs to up-skill radiographers. A comparative study between conventional and digital imaging was undertaken to compare outcomes and evaluate the need for reject analysis. However, digital technology still being at its early development stages, setting a credible reject analysis program became the major task of the study. It took the department, with the help of the suppliers of the computed radiography reader and the picture archiving and communication system, over 2 years of software enhancement to build a reliable digital repeat analysis system. The results were supportive of both philosophies; the number of repeats as a result of exposure factors was reduced dramatically; however, the percentage of repeats as a result of positioning skills was slightly on the increase for the simple reason that some rejects in the conventional system qualifying for both exposure and positioning errors were classified as exposure error. The ability of digitally adjusting dark or light images reclassified some of those images as positioning errors. PMID:16421768

  10. Diffusion-Tensor MRI Based Skeletal Muscle Fiber Tracking

    PubMed Central

    Damon, Bruce M.; Buck, Amanda K. W.; Ding, Zhaohua

    2014-01-01

    A skeletal muscle's function is strongly influenced by the internal organization and geometric properties of its fibers, a property known as muscle architecture. Diffusion-tensor magnetic resonance imaging-based fiber tracking provides a powerful tool for non-invasive muscle architecture studies, has three-dimensional sensitivity, and uses a fixed frame of reference. Significant advances have been made in muscle fiber tracking technology, including defining seed points for fiber tracking, quantitatively characterizing muscle architecture, implementing denoising procedures, and testing validity and repeatability. Some examples exist of how these data can be integrated with those from other advanced MRI and computational methods to provide novel insights into muscle function. Perspectives are offered regarding future directions in muscle diffusion-tensor imaging, including needs to develop an improved understanding for the microstructural basis for reduced and anisotropic diffusion, establish the best practices for data acquisition and analysis, and integrate fiber tracking with other physiological data. PMID:25429308

  11. Structures of designed armadillo-repeat proteins show propagation of inter-repeat interface effects.

    PubMed

    Reichen, Christian; Madhurantakam, Chaithanya; Hansen, Simon; Grütter, Markus G; Plückthun, Andreas; Mittl, Peer R E

    2016-01-01

    The armadillo repeat serves as a scaffold for the development of modular peptide-recognition modules. In order to develop such a system, three crystal structures of designed armadillo-repeat proteins with third-generation N-caps (YIII-type), four or five internal repeats (M-type) and second-generation C-caps (AII-type) were determined at 1.8 Å (His-YIIIM4AII), 2.0 Å (His-YIIIM5AII) and 1.95 Å (YIIIM5AII) resolution and compared with those of variants with third-generation C-caps. All constructs are full consensus designs in which the internal repeats have exactly the same sequence, and hence identical conformations of the internal repeats are expected. The N-cap and internal repeats M1 to M3 are indeed extremely similar, but the comparison reveals structural differences in internal repeats M4 and M5 and the C-cap. These differences are caused by long-range effects of the C-cap, contacting molecules in the crystal, and the intrinsic design of the repeat. Unfortunately, the rigid-body movement of the C-terminal part impairs the regular arrangement of internal repeats that forms the putative peptide-binding site. The second-generation C-cap improves the packing of buried residues and thereby the stability of the protein. These considerations are useful for future improvements of an armadillo-repeat-based peptide-recognition system. PMID:26894544

  12. Imaging and pathology findings after an initial negative MRI-US fusion-guided and 12-core extended sextant prostate biopsy session

    PubMed Central

    Hong, Cheng William; Walton-Diaz, Annerleim; Rais-Bahrami, Soroush; Hoang, Anthony N.; Türkbey, Barış; Stamatakis, Lambros; Xu, Sheng; Amalou, Hayet; Minhaj Siddiqui, M.; Nix, Jeffrey W.; Vourganti, Srinivas; Merino, Maria J.; Choyke, Peter L.; Wood, Bradford J.; Pinto, Peter A.

    2014-01-01

    PURPOSE A magnetic resonance imaging-ultrasonography (MRI-US) fusion-guided prostate biopsy increases detection rates compared to an extended sextant biopsy. The imaging characteristics and pathology outcomes of subsequent biopsies in patients with initially negative MRI-US fusion biopsies are described in this study. MATERIALS AND METHODS We reviewed 855 biopsy sessions of 751 patients (June 2007 to March 2013). The fusion biopsy consisted of two cores per lesion identified on multiparametric MRI (mpMRI) and a 12-core extended sextant transrectal US (TRUS) biopsy. Inclusion criteria were at least two fusion biopsy sessions, with a negative first biopsy and mpMRI before each. RESULTS The detection rate on the initial fusion biopsy was 55.3%; 336 patients had negative findings. Forty-one patients had follow-up fusion biopsies, but only 34 of these were preceded by a repeat mpMRI. The median interval between biopsies was 15 months. Fourteen patients (41%) were positive for cancer on the repeat MRI-US fusion biopsy. Age, prostate-specific antigen (PSA), prostate volume, PSA density, digital rectal exam findings, lesion diameter, and changes on imaging were comparable between patients with negative and positive rebiopsies. Of the patients with positive rebiopsies, 79% had a positive TRUS biopsy before referral (P = 0.004). Ten patients had Gleason 3+3 disease, three had 3+4 disease, and one had 4+4 disease. CONCLUSION In patients with a negative MRI-US fusion prostate biopsy and indications for repeat biopsy, the detection rate of the follow-up sessions was lower than the initial detection rate. Of the prostate cancers subsequently found, 93% were low grade (≤3+4). In this low risk group of patients, increasing the follow-up time interval should be considered in the appropriate clinical setting. PMID:24509182

  13. MRI of nasopharyngeal adenoid hypertrophy.

    PubMed

    Surov, Alexey; Ryl, Ina; Bartel-Friedrich, Sylvia; Wienke, Andreas; Kösling, Sabrina

    2016-10-01

    Nasopharyngeal adenoid hypertrophy (NAH) is a typical benign lesion. Due to involution, nasopharyngeal lymphatic tissue usually is not found in adults beyond the 30th to 40th year of life. However, occasionally NAH has been recognized after the 50th or 60th year. The aim of this study is to identify the frequency of NAH and to analyze its MRI findings in different age groups. From 2007 to 2011, 6693 MR investigations of the head were performed at our institution. MRI was obtained with a 1.5 T MRI device. NAH was identified in 18.0% of the patients. The frequency of NAH varied from 60.3% to 1.0% in the different age groups. The mean size of NAH was 23.2 ± 4.5 mm in cranio-caudal, 31.1 ± 5.2 mm in left-right, and 14.2 ± 4.1 mm in the anterior-posterior direction. The left-right and cranio-caudal sizes of NAH were largest in the 0-9 age group and decreased with age. On T1-w images most lesions (95.4%) were hypointense in comparison to the adjacent musculature. On T2-w fat-saturated images 82.4% of the lesions were hyperintense. After intravenous administration of contrast medium most lesions showed a slight enhancement (58.6%). Moderate enhancement was seen in 32.4% and a marked enhancement was identified in 9.0%. In the 0-9 age group most lesions showed a slight enhancement. Cysts within NAH were identified in 433 cases (35.9%). The frequency of cysts increased continuously with age, namely from 10.9% to 65.2%.

  14. Functional Imaging: CT and MRI

    PubMed Central

    van Beek, Edwin JR; Hoffman, Eric A

    2008-01-01

    Synopsis Numerous imaging techniques permit evaluation of regional pulmonary function. Contrast-enhanced CT methods now allow assessment of vasculature and lung perfusion. Techniques using spirometric controlled MDCT allow for quantification of presence and distribution of parenchymal and airway pathology, Xenon gas can be employed to assess regional ventilation of the lungs and rapid bolus injections of iodinated contrast agent can provide quantitative measure of regional parenchymal perfusion. Advances in magnetic resonance imaging (MRI) of the lung include gadolinium-enhanced perfusion imaging and hyperpolarized helium imaging, which can allow imaging of pulmonary ventilation and .measurement of the size of emphysematous spaces. PMID:18267192

  15. 4D flow imaging with MRI

    PubMed Central

    Stankovic, Zoran; Allen, Bradley D.; Garcia, Julio; Jarvis, Kelly B.

    2014-01-01

    Magnetic resonance imaging (MRI) has become an important tool for the clinical evaluation of patients with cardiovascular disease. Since its introduction in the late 1980s, 2-dimensional phase contrast MRI (2D PC-MRI) has become a routine part of standard-of-care cardiac MRI for the assessment of regional blood flow in the heart and great vessels. More recently, time-resolved PC-MRI with velocity encoding along all three flow directions and three-dimensional (3D) anatomic coverage (also termed ‘4D flow MRI’) has been developed and applied for the evaluation of cardiovascular hemodynamics in multiple regions of the human body. 4D flow MRI allows for the comprehensive evaluation of complex blood flow patterns by 3D blood flow visualization and flexible retrospective quantification of flow parameters. Recent technical developments, including the utilization of advanced parallel imaging techniques such as k-t GRAPPA, have resulted in reasonable overall scan times, e.g., 8-12 minutes for 4D flow MRI of the aorta and 10-20 minutes for whole heart coverage. As a result, the application of 4D flow MRI in a clinical setting has become more feasible, as documented by an increased number of recent reports on the utility of the technique for the assessment of cardiac and vascular hemodynamics in patient studies. A number of studies have demonstrated the potential of 4D flow MRI to provide an improved assessment of hemodynamics which might aid in the diagnosis and therapeutic management of cardiovascular diseases. The purpose of this review is to describe the methods used for 4D flow MRI acquisition, post-processing and data analysis. In addition, the article provides an overview of the clinical applications of 4D flow MRI and includes a review of applications in the heart, thoracic aorta and hepatic system. PMID:24834414

  16. Stalled DNA Replication Forks at the Endogenous GAA Repeats Drive Repeat Expansion in Friedreich's Ataxia Cells.

    PubMed

    Gerhardt, Jeannine; Bhalla, Angela D; Butler, Jill Sergesketter; Puckett, James W; Dervan, Peter B; Rosenwaks, Zev; Napierala, Marek

    2016-08-01

    Friedreich's ataxia (FRDA) is caused by the expansion of GAA repeats located in the Frataxin (FXN) gene. The GAA repeats continue to expand in FRDA patients, aggravating symptoms and contributing to disease progression. The mechanism leading to repeat expansion and decreased FXN transcription remains unclear. Using single-molecule analysis of replicated DNA, we detected that expanded GAA repeats present a substantial obstacle for the replication machinery at the FXN locus in FRDA cells. Furthermore, aberrant origin activation and lack of a proper stress response to rescue the stalled forks in FRDA cells cause an increase in 3'-5' progressing forks, which could enhance repeat expansion and hinder FXN transcription by head-on collision with RNA polymerases. Treatment of FRDA cells with GAA-specific polyamides rescues DNA replication fork stalling and alleviates expansion of the GAA repeats, implicating DNA triplexes as a replication impediment and suggesting that fork stalling might be a therapeutic target for FRDA.

  17. Stalled DNA Replication Forks at the Endogenous GAA Repeats Drive Repeat Expansion in Friedreich's Ataxia Cells.

    PubMed

    Gerhardt, Jeannine; Bhalla, Angela D; Butler, Jill Sergesketter; Puckett, James W; Dervan, Peter B; Rosenwaks, Zev; Napierala, Marek

    2016-08-01

    Friedreich's ataxia (FRDA) is caused by the expansion of GAA repeats located in the Frataxin (FXN) gene. The GAA repeats continue to expand in FRDA patients, aggravating symptoms and contributing to disease progression. The mechanism leading to repeat expansion and decreased FXN transcription remains unclear. Using single-molecule analysis of replicated DNA, we detected that expanded GAA repeats present a substantial obstacle for the replication machinery at the FXN locus in FRDA cells. Furthermore, aberrant origin activation and lack of a proper stress response to rescue the stalled forks in FRDA cells cause an increase in 3'-5' progressing forks, which could enhance repeat expansion and hinder FXN transcription by head-on collision with RNA polymerases. Treatment of FRDA cells with GAA-specific polyamides rescues DNA replication fork stalling and alleviates expansion of the GAA repeats, implicating DNA triplexes as a replication impediment and suggesting that fork stalling might be a therapeutic target for FRDA. PMID:27425605

  18. Automated genotyping of dinucleotide repeat markers

    SciTech Connect

    Perlin, M.W.; Hoffman, E.P. |

    1994-09-01

    The dinucleotide repeats (i.e., microsatellites) such as CA-repeats are a highly polymorphic, highly abundant class of PCR-amplifiable markers that have greatly streamlined genetic mapping experimentation. It is expected that over 30,000 such markers (including tri- and tetranucleotide repeats) will be characterized for routine use in the next few years. Since only size determination, and not sequencing, is required to determine alleles, in principle, dinucleotide repeat genotyping is easily performed on electrophoretic gels, and can be automated using DNA sequencers. Unfortunately, PCR stuttering with these markers generates not one band for each allele, but a pattern of bands. Since closely spaced alleles must be disambiguated by human scoring, this poses a key obstacle to full automation. We have developed methods that overcome this obstacle. Our model is that the observed data is generated by arithmetic superposition (i.e., convolution) of multiple allele patterns. By quantitatively measuring the size of each component band, and exploiting the unique stutter pattern associated with each marker, closely spaced alleles can be deconvolved; this unambiguously reconstructs the {open_quotes}true{close_quotes} allele bands, with stutter artifact removed. We used this approach in a system for automated diagnosis of (X-linked) Duchenne muscular dystrophy; four multiplexed CA-repeats within the dystrophin gene were assayed on a DNA sequencer. Our method accurately detected small variations in gel migration that shifted the allele size estimate. In 167 nonmutated alleles, 89% (149/167) showed no size variation, 9% (15/167) showed 1 bp variation, and 2% (3/167) showed 2 bp variation. We are currently developing a library of dinucleotide repeat patterns; together with our deconvolution methods, this library will enable fully automated genotyping of dinucleotide repeats from sizing data.

  19. Reduced repetition suppression in the occipital visual cortex during repeated negative Chinese personality-trait word processing.

    PubMed

    Qiao, Fuqiang; Zheng, Li; Li, Lin; Zhu, Lei; Wang, Qianfeng

    2014-12-01

    Reduced neural activation have been consistently observed during repeated items processing, a phenomenon termed repetition suppression. The present study used functional magnetic resonance imaging (fMRI) to investigate whether and how stimuli of emotional valence affects repetition suppression by adopting Chinese personality-trait words as materials. Seventeen participants were required to read the negative and neutral Chinese personality-trait words silently. And then they were presented with repeated and novel items during scanning. Results showed significant repetition suppression in the inferior occipital gyrus only for neutral personality-trait words, whereas similar repetition suppression in the left inferior temporal gyrus and left middle temporal gyrus was revealed for both the word types. These results indicated common and distinct neural substrates during processing Chinese repeated negative and neutral personality-trait words.

  20. Characteristics of young children with persistent conduct problems 1 year after treatment with the Incredible Years program.

    PubMed

    Drugli, May Britt; Fossum, Sturla; Larsson, Bo; Morch, Willy-Tore

    2010-07-01

    In the present study, predictors of persistent conduct problems among children aged 4-8 years were investigated in a randomized controlled trial 1 year after treatment with the Incredible Years parent training program (PT), or combined parent training and child treatment (PT + CT). Data were collected before and after treatment and at a 1-year follow-up. Pre-treatment child characteristics predicting persistent conduct problems in the child at the 1-year follow-up were high levels of internalizing and aggression problems as reported by mothers. The only family characteristic predicting persistence of child conduct problems was having contacts with child protection services. Clinicians and researchers need to closely monitor and identify children with conduct problems not responding to parent training programs. These individuals and their families are likely to need further support. PMID:20012877

  1. [A case of neuro-Behçet's disease with repeating isolated thoracic spinal cord lesion].

    PubMed

    Shiote, Mito; Kido, Yukiko; Hayashi, Takeshi; Manabe, Yasuhiro; Kashihara, Ken-ichi; Nagano, Isao; Shoji, Mikio; Abe, Koji

    2003-06-01

    We reported a 45-year-old man who had repeated isolated thoracic spinal cord lesion on MRI in the clinical course of seven years. He had transient bilateral plantar numbness and urinary retention on December, 1994. Then, spastic paraplegia, total anesthesia of feet, and severe sphincter disturbance struck him on May, 1995. He was diagnosed as incomplete Behçet's disease and neuro-Behçet's disease on June, 1995 because of recurrent oral aphta, genital ulceration, and foliculitis. T2-weighted magnetic resonance imaging showed high intensity enhanced with Gd-DTPA in thoracic spinal cord from Th 5 to 8 level. Any other abnormal lesion on brain or spinal MRI was not observed. He was treated with corticosteroids and recovered incompletely. Another two big attacks occurred to him. No new lesion but thoracic spinal cord lesion was observed. We conclude that this case is the first reported example of neuro-Behçet's disease with repeating isolated thoracic spinal cord lesion.

  2. Novel Imaging of Prostate Cancer with MRI, MRI/US, and PET.

    PubMed

    Koo, Phillip J; Kwak, Jennifer J; Pokharel, Sajal; Choyke, Peter L

    2015-12-01

    Imaging of prostate cancer presents many challenges to the imaging community. There has been much progress in this space in large part due to MRI and PET radiopharmaceuticals. Though MRI has been focused on the evaluation of local disease and PET on the detection of metastatic disease, these two areas do converge and will be complementary especially with the growth of new PET/MRI technologies. In this review article, we review novel MRI, MRI/US, and PET radiopharmaceuticals which will offer insight into the future direction of imaging in prostate cancer.

  3. Novel Imaging of Prostate Cancer with MRI, MRI/US, and PET.

    PubMed

    Koo, Phillip J; Kwak, Jennifer J; Pokharel, Sajal; Choyke, Peter L

    2015-12-01

    Imaging of prostate cancer presents many challenges to the imaging community. There has been much progress in this space in large part due to MRI and PET radiopharmaceuticals. Though MRI has been focused on the evaluation of local disease and PET on the detection of metastatic disease, these two areas do converge and will be complementary especially with the growth of new PET/MRI technologies. In this review article, we review novel MRI, MRI/US, and PET radiopharmaceuticals which will offer insight into the future direction of imaging in prostate cancer. PMID:26462919

  4. Long-term vascular access ports as a means of sedative administration in a rodent fMRI survival model.

    PubMed

    Hettinger, Patrick C; Li, Rupeng; Yan, Ji-Geng; Matloub, Hani S; Cho, Younghoon R; Pawela, Christopher P; Rowe, Daniel B; Hyde, James S

    2011-09-15

    The purpose of this study is to develop a rodent functional magnetic resonance imaging (fMRI) survival model with the use of heparin-coated vascular access devices. Such a model would ease the administration of sedative agents, reduce the number of animals required in survival experiments and eliminate animal-to-animal variability seen in previous designs. Seven male Sprague-Dawley rats underwent surgical placement of an MRI-compatible vascular access port, followed by implantable electrode placement on the right median nerve. Functional MRI during nerve stimulation and resting-state functional connectivity MRI (fcMRI) were performed at times 0, 2, 4, 8 and 12 weeks postoperatively using a 9.4T scanner. Anesthesia was maintained using intravenous dexmedetomidine and reversed using atipamezole. There were no fatalities or infectious complications during this study. All vascular access ports remained patent. Blood oxygen level dependent (BOLD) activation by electrical stimulation of the median nerve using implanted electrodes was seen within the forelimb sensory region (S1FL) for all animals at all time points. The number of activated voxels decreased at time points 4 and 8 weeks, returning to a normal level at 12 weeks, which is attributed to scar tissue formation and resolution around the embedded electrode. The applications of this experiment extend far beyond the scope of peripheral nerve experimentation. These vascular access ports can be applied to any survival MRI study requiring repeated medication administration, intravenous contrast, or blood sampling.

  5. In vivo evaluation of the effect of stimulus distribution on FIR statistical efficiency in event-related fMRI.

    PubMed

    Jansma, J Martijn; de Zwart, Jacco A; van Gelderen, Peter; Duyn, Jeff H; Drevets, Wayne C; Furey, Maura L

    2013-05-15

    Technical developments in MRI have improved signal to noise, allowing use of analysis methods such as Finite impulse response (FIR) of rapid event related functional MRI (er-fMRI). FIR is one of the most informative analysis methods as it determines onset and full shape of the hemodynamic response function (HRF) without any a priori assumptions. FIR is however vulnerable to multicollinearity, which is directly related to the distribution of stimuli over time. Efficiency can be optimized by simplifying a design, and restricting stimuli distribution to specific sequences, while more design flexibility necessarily reduces efficiency. However, the actual effect of efficiency on fMRI results has never been tested in vivo. Thus, it is currently difficult to make an informed choice between protocol flexibility and statistical efficiency. The main goal of this study was to assign concrete fMRI signal to noise values to the abstract scale of FIR statistical efficiency. Ten subjects repeated a perception task with five random and m-sequence based protocol, with varying but, according to literature, acceptable levels of multicollinearity. Results indicated substantial differences in signal standard deviation, while the level was a function of multicollinearity. Experiment protocols varied up to 55.4% in standard deviation. Results confirm that quality of fMRI in an FIR analysis can significantly and substantially vary with statistical efficiency. Our in vivo measurements can be used to aid in making an informed decision between freedom in protocol design and statistical efficiency.

  6. The effect of an official match on repeated sprint ability in junior basketball players.

    PubMed

    Caprino, Davide; Clarke, Neil David; Delextrat, Anne

    2012-01-01

    The aim of this study was to investigate the effect of an official basketball match on repeated sprint ability indices in male junior players. Ten (16 ± 1 years old; 183.6 ± 7.0 cm; 76.6 ± 8.0 kg) starting players for their teams performed three repeated sprint ability tests, before, at half-time and immediately after an official match. Each repeated sprint ability test consisted of 10 shuttle-run sprints of 30 m (15 + 15 m) separated by 30 seconds of passive recovery. The matches were video-taped to determine the frequency of eight types of movement patterns, and blood lactate concentration was measured before and immediately after each repeated sprint ability test. Differences in total time, ideal time and percentage decrement between tests was assessed by a one-way analysis of variance (ANOVA) with repeated measures, while a two-way ANOVA with repeated measures was used to identify differences in blood lactate concentration. The main results indicated a significant decrease in total movement frequency (-9.9%), high-intensity activity frequency (-13.3%), run frequency (-13.0%) and sprint frequency (-23.3%) in the second compared to the first half, and significantly worse total time and ideal time at the end of the match, compared to the start and half-time (differences ranging from -2.1% to -2.9%, P < 0.05). The practical implications of these findings suggest that regional basketball players should participate in conditioning sessions that focus on the improvement of repeated sprint ability.

  7. Physics of MRI: a primer.

    PubMed

    Plewes, Donald B; Kucharczyk, Walter

    2012-05-01

    This article is based on an introductory lecture given for the past many years during the "MR Physics and Techniques for Clinicians" course at the Annual Meeting of the ISMRM. This introduction is not intended to be a comprehensive overview of the field, as the subject of magnetic resonance imaging (MRI) physics is large and complex. Rather, it is intended to lay a conceptual foundation by which magnetic resonance image formation can be understood from an intuitive perspective. The presentation is nonmathematical, relying on simple models that take the reader progressively from the basic spin physics of nuclei, through descriptions of how the magnetic resonance signal is generated and detected in an MRI scanner, the foundations of nuclear magnetic resonance (NMR) relaxation, and a discussion of the Fourier transform and its relation to MR image formation. The article continues with a discussion of how magnetic field gradients are used to facilitate spatial encoding and concludes with a development of basic pulse sequences and the factors defining image contrast.

  8. MRI-conditional pacemakers: current perspectives

    PubMed Central

    Ferreira, António M; Costa, Francisco; Tralhão, António; Marques, Hugo; Cardim, Nuno; Adragão, Pedro

    2014-01-01

    Use of both magnetic resonance imaging (MRI) and pacing devices has undergone remarkable growth in recent years, and it is estimated that the majority of patients with pacemakers will need an MRI during their lifetime. These investigations will generally be denied due to the potentially dangerous interactions between cardiac devices and the magnetic fields and radio frequency energy used in MRI. Despite the increasing reports of uneventful scanning in selected patients with conventional pacemakers under close surveillance, MRI is still contraindicated in those circumstances and cannot be considered a routine procedure. These limitations prompted a series of modifications in generator and lead engineering, designed to minimize interactions that could compromise device function and patient safety. The resulting MRI-conditional pacemakers were first introduced in 2008 and the clinical experience gathered so far supports their safety in the MRI environment if certain conditions are fulfilled. With this technology, new questions and controversies arise regarding patient selection, clinical impact, and cost-effectiveness. In this review, we discuss the potential risks of MRI in patients with electronic cardiac devices and present updated information regarding the features of MRI-conditional pacemakers and the clinical experience with currently available models. Finally, we provide some guidance on how to scan patients who have these devices and discuss future directions in the field. PMID:24851058

  9. MRI endoscopy using intrinsically localized probes

    PubMed Central

    Sathyanarayana, Shashank; Bottomley, Paul A.

    2009-01-01

    Magnetic resonance imaging (MRI) is traditionally performed with fixed externally applied gradient magnetic fields and is hence intrinsically locked to the laboratory frame of reference (FoR). Here a method for high-resolution MRI that employs active, catheter-based, tiny internal probes that utilize the spatial properties of the probe itself for localization is proposed and demonstrated at 3 T. Because these properties are intrinsic to the probe, they move with it, transforming MRI from the laboratory FoR to the FoR of the device itself, analogous to an endoscope. The “MRI endoscope” can utilize loop coils and loopless antennas with modified sensitivity, in combination with adiabatic excitation by the device itself, to restrict the MRI sensitivity to a disk-shaped plane a few mm thick. Excitation with the MRI endoscope limits the eddy currents induced in the sample to an excited volume whose size is orders of magnitude below that excited by a conventional body MRI coil. Heat testing shows maximum local temperature increases of <1 °C during MRI, within regulatory guidelines. The method is demonstrated in a kiwifruit, in intact porcine and rabbit aortas, and in an atherosclerotic human iliac artery specimen, with in-plane resolution as small as 80 μm and 1.5–5 mm slice thickness. PMID:19378751

  10. High-performance computing MRI simulations.

    PubMed

    Stöcker, Tony; Vahedipour, Kaveh; Pflugfelder, Daniel; Shah, N Jon

    2010-07-01

    A new open-source software project is presented, JEMRIS, the Jülich Extensible MRI Simulator, which provides an MRI sequence development and simulation environment for the MRI community. The development was driven by the desire to achieve generality of simulated three-dimensional MRI experiments reflecting modern MRI systems hardware. The accompanying computational burden is overcome by means of parallel computing. Many aspects are covered that have not hitherto been simultaneously investigated in general MRI simulations such as parallel transmit and receive, important off-resonance effects, nonlinear gradients, and arbitrary spatiotemporal parameter variations at different levels. The latter can be used to simulate various types of motion, for instance. The JEMRIS user interface is very simple to use, but nevertheless it presents few limitations. MRI sequences with arbitrary waveforms and complex interdependent modules are modeled in a graphical user interface-based environment requiring no further programming. This manuscript describes the concepts, methods, and performance of the software. Examples of novel simulation results in active fields of MRI research are given.

  11. Pantopaque simulating thrombosed intracranial aneurysms on MRI

    SciTech Connect

    Lidov, M.W.; Silvers, A.R.; Mosesson, R.E.; Stollman, A.L.; Som, P.M.

    1996-03-01

    A patient is presented in whom iophendylate (Pantopaque) within the basal cisterns closely resembled the appearance on MRI of thrombosed aneurysms of the middle cerebral arteries. The sometimes subtle differences between the appearances on MRI of Pantopaque and aneurysmal clot are discussed to permit accurate diagnosis without resorting to more invasive diagnostic tests, such as cerebral angiography. 5 refs., 4 figs.

  12. Cranial computed tomography and MRI. Second edition

    SciTech Connect

    Lee, S.H.; Rao, K.C.V.G.

    1987-01-01

    This book contains 17 chapters. Some of the chapter titles are: Physics and Instrumentation: CT and MRI; Normal Cranial CT and MRI Anatomy; The Orbit; The ventricles and Subarachnoid Spaces in Children; Primary Tumors in Children; Trauma: Craniocerebral and Craniofacial; Infectious Disease; and Stroke.

  13. Variable efficacy of repeated annual influenza vaccination.

    PubMed

    Smith, D J; Forrest, S; Ackley, D H; Perelson, A S

    1999-11-23

    Conclusions have differed in studies that have compared vaccine efficacy in groups receiving influenza vaccine for the first time to efficacy in groups vaccinated more than once. For example, the Hoskins study [Hoskins, T. W., Davis, J. R., Smith, A. J., Miller, C. L. & Allchin, A. (1979) Lancet i, 33-35] concluded that repeat vaccination was not protective in the long term, whereas the Keitel study [Keitel, W. A., Cate, T. R., Couch, R. B., Huggins, L. L. & Hess, K. R. (1997) Vaccine 15, 1114-1122] concluded that repeat vaccination provided continual protection. We propose an explanation, the antigenic distance hypothesis, and test it by analyzing seven influenza outbreaks that occurred during the Hoskins and Keitel studies. The hypothesis is that variation in repeat vaccine efficacy is due to differences in antigenic distances among vaccine strains and between the vaccine strains and the epidemic strain in each outbreak. To test the hypothesis, antigenic distances were calculated from historical hemagglutination inhibition assay tables, and a computer model of the immune response was used to predict the vaccine efficacy of individuals given different vaccinations. The model accurately predicted the observed vaccine efficacies in repeat vaccinees relative to the efficacy in first-time vaccinees (correlation 0.87). Thus, the antigenic distance hypothesis offers a parsimonious explanation of the differences between and within the Hoskins and Keitel studies. These results have implications for the selection of influenza vaccine strains, and also for vaccination strategies for other antigenically variable pathogens that might require repeated vaccination. PMID:10570188

  14. Variable efficacy of repeated annual influenza vaccination.

    PubMed

    Smith, D J; Forrest, S; Ackley, D H; Perelson, A S

    1999-11-23

    Conclusions have differed in studies that have compared vaccine efficacy in groups receiving influenza vaccine for the first time to efficacy in groups vaccinated more than once. For example, the Hoskins study [Hoskins, T. W., Davis, J. R., Smith, A. J., Miller, C. L. & Allchin, A. (1979) Lancet i, 33-35] concluded that repeat vaccination was not protective in the long term, whereas the Keitel study [Keitel, W. A., Cate, T. R., Couch, R. B., Huggins, L. L. & Hess, K. R. (1997) Vaccine 15, 1114-1122] concluded that repeat vaccination provided continual protection. We propose an explanation, the antigenic distance hypothesis, and test it by analyzing seven influenza outbreaks that occurred during the Hoskins and Keitel studies. The hypothesis is that variation in repeat vaccine efficacy is due to differences in antigenic distances among vaccine strains and between the vaccine strains and the epidemic strain in each outbreak. To test the hypothesis, antigenic distances were calculated from historical hemagglutination inhibition assay tables, and a computer model of the immune response was used to predict the vaccine efficacy of individuals given different vaccinations. The model accurately predicted the observed vaccine efficacies in repeat vaccinees relative to the efficacy in first-time vaccinees (correlation 0.87). Thus, the antigenic distance hypothesis offers a parsimonious explanation of the differences between and within the Hoskins and Keitel studies. These results have implications for the selection of influenza vaccine strains, and also for vaccination strategies for other antigenically variable pathogens that might require repeated vaccination.

  15. Role of Percutaneous Image Guided Biopsy in Spinal Lesions: Adequacy and Correlation with MRI Findings

    PubMed Central

    2016-01-01

    Introduction Although, MRI has increased our understanding of spinal pathologies, accurate diagnosis of spinal lesions need biopsy, so that early treatment can be initiated. Aim To evaluate the accuracy of biopsy, safety and yield of percutaneously done image guided spinal biopsy using a large bore needle and correlate between MRI findings and biopsy as well as the importance of various MRI findings in establishing the diagnosis. Materials and Methods All spinal lesions after clinical and MRI evaluation were subjected to Jamshidi Needle biopsy using 11 gauge needles. Biopsy material was sent for culture/sensitivity, AFB smear and histopathological examination. The outcome assessment included percentage of patients in whom diagnosis was changed after biopsy, yield in biopsy and complications of biopsy. MRI findings, biopsy findings and final diagnosis were correlated to know the sensitivity and specificity of MRI and biopsy diagnosis. Logistic regression analysis was used to study the importance of each of MRI findings in making a diagnosis. Results Forty five patients with spinal lesions underwent biopsy using an 11 gauge Jamshidi needle. Initial biopsy was inconclusive in 4 patients giving a positive yield in about 91.2% of cases and a repeat biopsy ensured conclusive report in all cases. Following biopsy there was a change in diagnosis in 8% cases. MRI showed sensitivity of 85.71% and specificity of 93.54% for the diagnosis of malignancy and sensitivity of 85.71% and specificity of 86.48% for the diagnosis of tuberculosis. In contrast, initial biopsy had sensitivity of 92.85% and specificity of 100% for the diagnosis of malignancy and sensitivity of 71.42% and specificity of 100 % for the diagnosis of infection. Logistic regression analysis showed good correlation between malignancy and posterior bugle in the vertebral body in the absence of a fracture (p = 0.007), involvement of pedicles and posterior elements (p = 0.001) and soft tissue extension (p = 0

  16. NMR, MRI, and spectroscopic MRI in inhomogeneous fields

    DOEpatents

    Demas, Vasiliki; Pines, Alexander; Martin, Rachel W; Franck, John; Reimer, Jeffrey A

    2013-12-24

    A method for locally creating effectively homogeneous or "clean" magnetic field gradients (of high uniformity) for imaging (with NMR, MRI, or spectroscopic MRI) both in in-situ and ex-situ systems with high degrees of inhomogeneous field strength. THe method of imaging comprises: a) providing a functional approximation of an inhomogeneous static magnetic field strength B.sub.0({right arrow over (r)}) at a spatial position {right arrow over (r)}; b) providing a temporal functional approximation of {right arrow over (G)}.sub.shim(t) with i basis functions and j variables for each basis function, resulting in v.sub.ij variables; c) providing a measured value .OMEGA., which is an temporally accumulated dephasing due to the inhomogeneities of B.sub.0({right arrow over(r)}); and d) minimizing a difference in the local dephasing angle .phi.({right arrow over (r)},t)=.gamma..intg..sub.0.sup.t{square root over (|{right arrow over (B)}.sub.1({right arrow over (r)},t')|.sup.2+({right arrow over (r)}{right arrow over (G)}.sub.shimG.sub.shim(t')+.parallel.{right arrow over (B)}.sub.0({right arrow over (r)}).parallel..DELTA..omega.({right arrow over (r)},t'/.gamma/).sup.2)}dt'-.OMEGA. by varying the v.sub.ij variables to form a set of minimized v.sub.ij variables. The method requires calibration of the static fields prior to minimization, but may thereafter be implemented without such calibration, may be used in open or closed systems, and potentially portable systems.

  17. Rate analysis for a hybrid quantum repeater

    SciTech Connect

    Bernardes, Nadja K.; Loock, Peter van

    2011-01-15

    We present a detailed rate analysis for a hybrid quantum repeater assuming perfect memories and using optimal probabilistic entanglement generation and deterministic swapping routines. The hybrid quantum repeater protocol is based on atomic qubit-entanglement distribution through optical coherent-state communication. An exact, analytical formula for the rates of entanglement generation in quantum repeaters is derived, including a study on the impacts of entanglement purification and multiplexing strategies. More specifically, we consider scenarios with as little purification as possible and we show that for sufficiently low local losses, such purifications are still more powerful than multiplexing. In a possible experimental scenario, our hybrid system can create near-maximally entangled (F=0.98) pairs over a distance of 1280 km at rates of the order of 100 Hz.

  18. Do gamma-ray burst sources repeat?

    NASA Technical Reports Server (NTRS)

    Meegan, Charles A.; Hartmann, Dieter H.; Brainerd, J. J.; Briggs, Michael S.; Paciesas, William S.; Pendleton, Geoffrey; Kouveliotou, Chryssa; Fishman, Gerald; Blumenthal, George; Brock, Martin

    1995-01-01

    The demonstration of repeated gamma-ray bursts from an individual source would severely constrain burst source models. Recent reports (Quashnock and Lamb, 1993; Wang and Lingenfelter, 1993) of evidence for repetition in the first BATSE burst catalog have generated renewed interest in this issue. Here, we analyze the angular distribution of 585 bursts of the second BATSE catalog (Meegan et al., 1994). We search for evidence of burst recurrence using the nearest and farthest neighbor statistic and the two-point angular correlation function. We find the data to be consistent with the hypothesis that burst sources do not repeat; however, a repeater fraction of up to about 20% of the observed bursts cannot be excluded.

  19. False-positive Extra-Mammary Findings in Breast MRI: Another Cause for Concern.

    PubMed

    Padia, Shilpa A; Freyvogel, Mary; Dietz, Jill; Valente, Stephanie; O'Rourke, Colin; Grobmyer, Stephen R

    2016-01-01

    Breast magnetic resonance imaging (MRI) has been repeatedly shown to have a high false-positive rate for additional findings in the breast resulting in additional breast imaging and biopsies. We hypothesize that breast MRI is also associated with a high rate of false-positive findings outside of the breast requiring additional evaluation, interventions, and delays in treatment. We performed a retrospective review of all breast MRIs performed on breast cancer patients in 2010 at a single institution. MRI reports were analyzed for extra-mammary findings. The timing and yield of the additional procedures was also analyzed. Three hundred and twenty-seven breast cancer patients (average age = 53.53 ± 11.08 years) had a breast MRI. Incidental, extra-mammary findings were reported in 35/327 patients (10.7%) with a total of 38 incidental findings. The extra-mammary findings were located in the liver (n = 21, 60.0%), thoracic cavity (n = 12, 34.3%), kidneys (n = 1, 2.9%), musculoskeletal system (n = 3, 8.6%), and neck (n = 1, 2.9%). Eighteen of the 35 patients (51.4%) received additional radiographic imaging, 3 (8.6%) received additional laboratory testing, 2 (5.7%) received additional physician referrals and 2 (5.7%) received a biopsy of the finding. The average time to additional procedures in these patients was 14.5 days. None of the incidental, extra-mammary findings were associated with breast cancer or other malignancy. Breast MRI was associated with a high rate (10.7%) of extra-mammary findings, which led to costly additional imaging studies, referrals, and tests. These findings were not associated with breast cancer or other malignancies. Extra-mammary findings highlight an unrecognized adverse consequence of breast MRI.

  20. Impact of Cardiac Arrhythmia on Velocity Quantification by ECG gated Phase Contrast MRI

    PubMed Central

    Markl, Michael; Fluckiger, Jacob; Lee, Daniel C.; Ng, Jason; Goldberger, Jeffrey J.

    2014-01-01

    Objective To systematically investigate the impact of beat-to-beat variations on ECG gated multi-beat flow imaging with phase contrast (PC) MRI based on real time in-vivo TEE data in patients with known arrhythmia. Methods Real-time 2D Doppler transesophageal echocardiography (TEE) was performed in five patients with atrial fibrillation (4 male, age=64±8.7 years). TEE data provided real-time left atrial (LA) and left ventricular (LV) flow velocities in consecutive cardiac cycles with different RR-interval durations. PC-MRI acquisitions were simulated from the TEE velocity measures by constructing time-resolved k-space data for segmented sampling schemes typically used for ECG gated 2D PC MRI. Each simulation was repeated 100 times to minimize effects from data that may be weighted to a particular beat in the center of k-space. The resulting LA and LV velocities were compared to the average TEE velocities and data from individual cardiac cycles. Results Despite beat-to-beat variations velocities in TEE data, ECG gated flow imaging with MRI could reproduce persistent average LA and LV mean velocities within 7.0–7.4% compared to TEE. Conclusions PC-MRI velocity measurements in patients with varying R-R interval durations are not significantly different from time-averaged real-time velocity data for a typical segmented k-space data acquisition schemes. Though beat-to-beat variations in atrial velocities that were observed with TEE cannot be detected with ECG gated multi-beat PC MRI, it can reliably assess average flow patterns across multiple beats PMID:25978593

  1. Hemodynamic Nonlinearities Affect BOLD fMRI Response Timing and Amplitude

    PubMed Central

    de Zwart, Jacco A; van Gelderen, Peter; Jansma, J Martijn; Fukunaga, Masaki; Bianciardi, Marta; Duyn, Jeff H

    2009-01-01

    The interpretation of functional Magnetic Resonance Imaging (fMRI) studies based on Blood Oxygen-Level Dependent (BOLD) contrast generally relies on the assumption of a linear relationship between evoked neuronal activity and fMRI response. While nonlinearities in this relationship have been suggested by a number of studies, it remains unclear to what extent they relate to the neurovascular response and are therefore inherent to BOLD-fMRI. Full characterization of potential vascular nonlinearities is required for accurate inferences about the neuronal system under study. To investigate the extent of vascular nonlinearities, evoked activity was studied in humans with BOLD-fMRI (n=28) and Magnetoencephalography (MEG) (n=5). Brief (600-800 ms) rapidly repeated (1 Hz) visual stimuli were delivered using a stimulation paradigm that minimized neuronal nonlinearities. Nevertheless, BOLD-fMRI experiments showed substantial remaining nonlinearities. The smallest stimulus separation (200-400 ms) resulted in significant response broadening (15-20% amplitude decrease; 10-12% latency increase; 6-14% duration increase) with respect to a linear prediction. The substantial slowing and widening of the response in the presence of preceding stimuli suggests a vascular rather than neuronal origin to the observed non-linearity. This was confirmed by the MEG data, which showed no significant neuro-electric nonlinear interactions between stimuli as little as 200 ms apart. The presence of substantial vascular nonlinearities has important implications for rapid event-related studies by fMRI and other imaging modalities that infer neuronal activity from hemodynamic parameters. PMID:19520175

  2. Morphological asymmetries of mouse brain assessed by geometric morphometric analysis of MRI data.

    PubMed

    Barbeito-Andrés, Jimena; Bernal, Valeria; Gonzalez, Paula N

    2016-09-01

    Mammalian brain has repeated structures at both sides of the median plane, although some asymmetries have been described even under normal conditions. Characterizing normal patterns of asymmetry in mouse brain is important to recognize features that depart from expected ranges in the most widely used mammalian model. Analyses on brain morphology based on magnetic resonance image (MRI) have largely focused on volumes while less is known about shape asymmetry. We introduce a flexible protocol based on geometric morphometrics to assess patterns of asymmetry in shape and size of mouse brain from microMRI scans. After systematic digitization of landmarks and semilandmarks, we combine multivariate methods for statistical analyses with visualization tools to display the results. No preliminary treatment of the images (e.g. space normalization) is needed to collect data on MRI slices and visual representations improve the interpretation of the results. Results indicated that the protocol is highly repeatable. Asymmetry was more evident for shape than for size. Particularly, fluctuating asymmetry accounted for more variation than directional asymmetry in all brain regions. Since this approach can detect subtle shape variation between sides, it is a promising methodology to explore morphological changes in the brain of model organisms and can be applied in future studies addressing the effect of genetic and environmental factors on brain morphology. PMID:27108357

  3. Morphological asymmetries of mouse brain assessed by geometric morphometric analysis of MRI data.

    PubMed

    Barbeito-Andrés, Jimena; Bernal, Valeria; Gonzalez, Paula N

    2016-09-01

    Mammalian brain has repeated structures at both sides of the median plane, although some asymmetries have been described even under normal conditions. Characterizing normal patterns of asymmetry in mouse brain is important to recognize features that depart from expected ranges in the most widely used mammalian model. Analyses on brain morphology based on magnetic resonance image (MRI) have largely focused on volumes while less is known about shape asymmetry. We introduce a flexible protocol based on geometric morphometrics to assess patterns of asymmetry in shape and size of mouse brain from microMRI scans. After systematic digitization of landmarks and semilandmarks, we combine multivariate methods for statistical analyses with visualization tools to display the results. No preliminary treatment of the images (e.g. space normalization) is needed to collect data on MRI slices and visual representations improve the interpretation of the results. Results indicated that the protocol is highly repeatable. Asymmetry was more evident for shape than for size. Particularly, fluctuating asymmetry accounted for more variation than directional asymmetry in all brain regions. Since this approach can detect subtle shape variation between sides, it is a promising methodology to explore morphological changes in the brain of model organisms and can be applied in future studies addressing the effect of genetic and environmental factors on brain morphology.

  4. Algorithm for quantifying advanced carotid artery atherosclerosis in humans using MRI and active contours

    NASA Astrophysics Data System (ADS)

    Adams, Gareth; Vick, G. W., III; Bordelon, Cassius; Insull, William; Morrisett, Joel

    2002-05-01

    A new algorithm for measuring carotid artery volumes and estimating atherosclerotic plaque volumes from MRI images has been developed and validated using pressure-perfusion-fixed cadaveric carotid arteries. Our method uses an active contour algorithm with the generalized gradient vector field force as the external force to localize the boundaries of the artery on each MRI cross-section. Plaque volume is estimated by an automated algorithm based on estimating the normal wall thickness for each branch of the carotid. Triplicate volume measurements were performed by a single observer on thirty-eight pairs of cadaveric carotid arteries. The coefficient of variance (COV) was used to quantify measurement reproducibility. Aggregate volumes were computed for nine contiguous slices bounding the carotid bifurcation. The median (mean +/- SD) COV for the 76 aggregate arterial volumes was 0.93% (1.47% +/- 1.52%) for the lumen volume, 0.95% (1.06% +/- 0.67%) for the total artery volume, and 4.69% (5.39% +/- 3.97%) for the plaque volume. These results indicate that our algorithm provides repeatable measures of arterial volumes and a repeatable estimate of plaque volume of cadaveric carotid specimens through analysis of MRI images. The algorithm also significantly decreases the amount of time necessary to generate these measurements.

  5. Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

    SciTech Connect

    Aubuchon, Adam C.; Chan, Michael D.; Lovato, James F.; Balamucki, Christopher J.; Ellis, Thomas L.; Tatter, Stephen B.; McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G.

    2011-11-15

    Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80-90). The mean retreatment dose was 84.4 Gy (range, 60-90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

  6. Safety of Repeated Yttrium-90 Radioembolization

    SciTech Connect

    Lam, Marnix G. E. H.; Louie, John D.; Iagaru, Andrei H.; Goris, Michael L.; Sze, Daniel Y.

    2013-10-15

    Purpose: Repeated radioembolization (RE) treatments carry theoretically higher risk of radiation-induced hepatic injury because of the liver's cumulative memory of previous exposure. We performed a retrospective safety analysis on patients who underwent repeated RE. Methods: From 2004 to 2011, a total of 247 patients were treated by RE. Eight patients (5 men, 3 women, age range 51-71 years) underwent repeated treatment of a targeted territory, all with resin microspheres (SIR-Spheres; Sirtex, Lane Cove, Australia). Adverse events were graded during a standardized follow-up. In addition, the correlation between the occurrence of RE-induced liver disease (REILD) and multiple variables was investigated in univariate and multivariate analyses in all 247 patients who received RE. Results: Two patients died shortly after the second treatment (at 84 and 107 days) with signs and symptoms of REILD. Both patients underwent whole liver treatment twice (cumulative doses 3.08 and 2.66 GBq). The other 6 patients demonstrated only minor toxicities after receiving cumulative doses ranging from 2.41 to 3.88 GBq. All patients experienced objective tumor responses. In the whole population, multifactorial analysis identified three risk factors associated with REILD: repeated RE (p = 0.036), baseline serum total bilirubin (p = 0.048), and baseline serum aspartate aminotransferase (p = 0.043). Repeated RE proved to be the only independent risk factor for REILD in multivariate analysis (odds ratio 9.6; p = 0.002). Additionally, the administered activity per target volume (in GBq/L) was found to be an independent risk factor for REILD, but only in whole liver treatments (p = 0.033). Conclusion: The risk of REILD appears to be elevated for repeated RE. Objective tumor responses were observed, but establishment of safety limits will require improvement in dosimetric measurement and prediction.

  7. The puzzle of the triple repeats

    SciTech Connect

    Morell, V.

    1993-06-04

    Two years ago, when researchers discovered the gene that causes a hereditary form of mental retardation known as fragile-X syndrome, they also turned up a mutation so unexpected geneticists are still scratching their heads over it. The defect, which makes genes balloon in size by adding extra copies of a three base-pair repeated sequence of DNA, was the first of its kind. Despite decades of study, nothing like it had ever been seen in any of the species that laid the foundations for modern genetics: bacteria, the fruit fly Drosophila melanogaster, and the mouse. The mutations caused by these expanding trinucleotide repeats turned out be common causes of human disease. In the past 2 years, they have been fingered as the culprits in three hereditary disorders besides fragile-X syndrome: myotronic dystrophy, spinobullar muscular atrophy (also known as Kennedy's disease), and just this March-Huntington's disease. The FMR-1 gene, which is the one at fault in fragile-X syndrome, shows just how much the trinucleotide repeats can expand. The normal gene carries at most 50 copies of the CGG trinucleotide. But in children who inherit the gene from these carriers and actually develop mental retardation and the other fragile-X symptoms, the FMR-1 gene may have hundreds to thousands of CGG repeats. Huge expansions of another trinucleotide repeat (CTG) can also occur from one generation to the next in the gene that causes myotonic dystrophy (DM), while smaller, although no less devastating, expansions in the CAG trinucleotide repeat lead to Huntington's and Kennedy's diseases.

  8. Risperidone in Children with Disruptive Behavior Disorders and Subaverage Intelligence: A 1-Year, Open-Label Study of 504 Patients

    ERIC Educational Resources Information Center

    Croonenberghs, Jan; Fegert, Joerg M.; Findling, Robert L.; de Smedt, Goedele; van Dongen, Stefan

    2005-01-01

    Objective: To determine the long-term safety and effectiveness of risperidone for severe disruptive behaviors in children. Method: A multisite, 1-year, open-label study of patients aged 5 to 14 years with disruptive behaviors and subaverage intelligence was conducted. Results: Seventy-three percent of the 504 patients enrolled completed the study.…

  9. Genetic evaluation of weaning weight and probability of lambing at 1 year of age in Targhee lambs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this study was to investigate genetic control of 120-day weaning weight and the probability of lambing at 1 year of age in Targhee ewe lambs. Records of 5,967 ewe lambs born from 1989 to 2012 and first exposed to rams for breeding at approximately 7 months of age were analyzed. Reco...

  10. Establishment of quantitative PCR (qPCR) and culture laboratory facilities in a field hospital in benin: 1-year results.

    PubMed

    Marion, Estelle; Ganlonon, Line; Claco, Eric; Blanchard, Simon; Kempf, Marie; Adeye, Ambroise; Chauty, Annick

    2014-12-01

    No simple diagnostic tool is available to confirm Mycobacterium ulcerans infection, which is an emerging disease reported in many rural areas of Africa. Here, we report the 1-year results of a hospital laboratory that was created in an area of endemicity of Benin to facilitate the diagnosis of M. ulcerans infection. PMID:25320228

  11. Endovascular Treatment of a Bleeding Secondary Aorto-Enteric Fistula. A Case Report with 1-Year Follow-up

    SciTech Connect

    Brountzos, Elias N. Vasdekis, Spyros; Kostopanagiotou, Georgia; Danias, Nikolaos; Alexopoulou, Efthymia; Petropoulou, Konstantina; Gouliamos, Athanasios; Perros, Georgios

    2007-09-15

    We report a patient with life-threatening gastrointestinal bleeding caused by a secondary aorto-enteric fistula. Because the patient had several comorbid conditions, we successfully stopped the bleeding by endovascular placement of a bifurcated aortic stent-graft. The patient developed periaortic infection 4 months later, but he was managed with antibiotics. The patient is well 1 year after the procedure.

  12. A randomized double-blind clinical trial of posterior composite restorations with or without bevel: 1-year follow-up

    PubMed Central

    COELHO-DE-SOUZA, Fábio Herrmann; CAMARGO, Junara Cristina; BESKOW, Tiago; BALESTRIN, Matheus Dalmolin; KLEIN-JÚNIOR, Celso Afonso; DEMARCO, Flávio Fernando

    2012-01-01

    Objective This randomized double-blind clinical trial compared the performance of posterior composite restorations with or without bevel, after 1-year follow-up. Material and Methods Thirteen volunteers requiring at least two posterior composite restorations were selected. Twenty-nine cavities were performed, comprising 14 without bevel (butt joint) and 15 with bevel preparation of the enamel cavosurface angle. All cavities were restored with simplified adhesive system (Adper Single Bond) and composite resin (Filtek P60). A halogen light curing unit was used through the study. Restorations were polished immediately. Analysis was carried out at baseline, after 6 months and after 1 year by a calibrated evaluator (Kappa), according to the FDI criteria. Data were statistically analyzed by Mann-Whitney test (p<0.05). Results Beveled and non-beveled cavities performed similarly after 1 year follow-up, regarding to fractures and retention, marginal adaptation, postoperative hypersensitivity, recurrence of caries, surface luster and anatomic form. However, for surface and marginal staining, beveled cavities showed significantly better performance (p<0.05) than butt joint restorations. Conclusions It was concluded that the restorations were acceptable after 1 year, but restorations placed in cavities with marginal beveling showed less marginal staining than those placed in non-beveled cavities. PMID:22666833

  13. 41 CFR 302-11.22 - May the 1-year time limitation be extended by my agency?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 41 Public Contracts and Property Management 4 2012-07-01 2012-07-01 false May the 1-year time... Federal Travel Regulation System RELOCATION ALLOWANCES RESIDENCE TRANSACTION ALLOWANCES 11-ALLOWANCES FOR EXPENSES INCURRED IN CONNECTION WITH RESIDENCE TRANSACTIONS General Rules Time Limitations § 302-11.22...

  14. 41 CFR 302-11.22 - May the 1-year time limitation be extended by my agency?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 4 2014-07-01 2014-07-01 false May the 1-year time... Federal Travel Regulation System RELOCATION ALLOWANCES RESIDENCE TRANSACTION ALLOWANCES 11-ALLOWANCES FOR EXPENSES INCURRED IN CONNECTION WITH RESIDENCE TRANSACTIONS General Rules Time Limitations § 302-11.22...

  15. 41 CFR 302-11.22 - May the 1-year time limitation be extended by my agency?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 41 Public Contracts and Property Management 4 2013-07-01 2012-07-01 true May the 1-year time... Federal Travel Regulation System RELOCATION ALLOWANCES RESIDENCE TRANSACTION ALLOWANCES 11-ALLOWANCES FOR EXPENSES INCURRED IN CONNECTION WITH RESIDENCE TRANSACTIONS General Rules Time Limitations § 302-11.22...

  16. Decrease in Television Viewing Predicts Lower Body Mass Index at 1-Year Follow-Up in Adolescents, but Not Adults

    ERIC Educational Resources Information Center

    French, Simone A.; Mitchell, Nathan R.; Hannan, Peter J.

    2012-01-01

    Objective: To examine associations between television viewing, sugar-sweetened beverage consumption, eating out, physical activity, and body weight change over 1 year. Design: Secondary data analysis from randomized intervention trial. Setting: Households in the community. Participants: Adults (n = 153) and adolescents (n = 72) from the same…

  17. Improving Academic Performance of School-Age Children by Physical Activity in the Classroom: 1-Year Program Evaluation

    ERIC Educational Resources Information Center

    Mullender-Wijnsma, Marijke J.; Hartman, Esther; de Greeff, Johannes W.; Bosker, Roel J.; Doolaard, Simone; Visscher, Chris

    2015-01-01

    Background: An intervention was designed that combined physical activity with learning activities. It was based upon evidence for positive effects of moderate to vigorous physical activity (MVPA) on academic achievement. The aim of this study was to describe the program implementation and effects on academic achievement after 1?year. Methods:…

  18. Temporally multiplexed quantum repeaters with atomic gases

    SciTech Connect

    Simon, Christoph; Riedmatten, Hugues de; Afzelius, Mikael

    2010-07-15

    We propose a temporally multiplexed version of the Duan-Lukin-Cirac-Zoller (DLCZ) quantum-repeater protocol using controlled inhomogeneous spin broadening in atomic gases. A first analysis suggests that the advantage of multiplexing is negated by noise due to spin-wave excitations corresponding to unobserved directions of Stokes photon emission. However, this problem can be overcome with the help of a moderate-finesse cavity which is in resonance with Stokes photons, but invisible to the anti-Stokes photons. Our proposal promises greatly enhanced quantum repeater performance with atomic gases.

  19. Detecting variable responses in time-series using repeated measures ANOVA: Application to physiologic challenges

    PubMed Central

    Macey, Paul M.; Schluter, Philip J.; Macey, Katherine E.; Harper, Ronald M.

    2016-01-01

    We present an approach to analyzing physiologic timetrends recorded during a stimulus by comparing means at each time point using repeated measures analysis of variance (RMANOVA). The approach allows temporal patterns to be examined without an a priori model of expected timing or pattern of response. The approach was originally applied to signals recorded from functional magnetic resonance imaging (fMRI) volumes-of-interest (VOI) during a physiologic challenge, but we have used the same technique to analyze continuous recordings of other physiological signals such as heart rate, breathing rate, and pulse oximetry. For fMRI, the method serves as a complement to whole-brain voxel-based analyses, and is useful for detecting complex responses within pre-determined brain regions, or as a post-hoc analysis of regions of interest identified by whole-brain assessments. We illustrate an implementation of the technique in the statistical software packages R and SAS. VOI timetrends are extracted from conventionally preprocessed fMRI images. A timetrend of average signal intensity across the VOI during the scanning period is calculated for each subject. The values are scaled relative to baseline periods, and time points are binned. In SAS, the procedure PROC MIXED implements the RMANOVA in a single step. In R, we present one option for implementing RMANOVA with the mixed model function “lme”. Model diagnostics, and predicted means and differences are best performed with additional libraries and commands in R; we present one example. The ensuing results allow determination of significant overall effects, and time-point specific within- and between-group responses relative to baseline. We illustrate the technique using fMRI data from two groups of subjects who underwent a respiratory challenge. RMANOVA allows insight into the timing of responses and response differences between groups, and so is suited to physiologic testing paradigms eliciting complex response patterns.

  20. Detecting variable responses in time-series using repeated measures ANOVA: Application to physiologic challenges.

    PubMed

    Macey, Paul M; Schluter, Philip J; Macey, Katherine E; Harper, Ronald M

    2016-01-01

    We present an approach to analyzing physiologic timetrends recorded during a stimulus by comparing means at each time point using repeated measures analysis of variance (RMANOVA). The approach allows temporal patterns to be examined without an a priori model of expected timing or pattern of response. The approach was originally applied to signals recorded from functional magnetic resonance imaging (fMRI) volumes-of-interest (VOI) during a physiologic challenge, but we have used the same technique to analyze continuous recordings of other physiological signals such as heart rate, breathing rate, and pulse oximetry. For fMRI, the method serves as a complement to whole-brain voxel-based analyses, and is useful for detecting complex responses within pre-determined brain regions, or as a post-hoc analysis of regions of interest identified by whole-brain assessments. We illustrate an implementation of the technique in the statistical software packages R and SAS. VOI timetrends are extracted from conventionally preprocessed fMRI images. A timetrend of average signal intensity across the VOI during the scanning period is calculated for each subject. The values are scaled relative to baseline periods, and time points are binned. In SAS, the procedure PROC MIXED implements the RMANOVA in a single step. In R, we present one option for implementing RMANOVA with the mixed model function "lme". Model diagnostics, and predicted means and differences are best performed with additional libraries and commands in R; we present one example. The ensuing results allow determination of significant overall effects, and time-point specific within- and between-group responses relative to baseline. We illustrate the technique using fMRI data from two groups of subjects who underwent a respiratory challenge. RMANOVA allows insight into the timing of responses and response differences between groups, and so is suited to physiologic testing paradigms eliciting complex response patterns.

  1. Detecting variable responses in time-series using repeated measures ANOVA: Application to physiologic challenges

    PubMed Central

    Macey, Paul M.; Schluter, Philip J.; Macey, Katherine E.; Harper, Ronald M.

    2016-01-01

    We present an approach to analyzing physiologic timetrends recorded during a stimulus by comparing means at each time point using repeated measures analysis of variance (RMANOVA). The approach allows temporal patterns to be examined without an a priori model of expected timing or pattern of response. The approach was originally applied to signals recorded from functional magnetic resonance imaging (fMRI) volumes-of-interest (VOI) during a physiologic challenge, but we have used the same technique to analyze continuous recordings of other physiological signals such as heart rate, breathing rate, and pulse oximetry. For fMRI, the method serves as a complement to whole-brain voxel-based analyses, and is useful for detecting complex responses within pre-determined brain regions, or as a post-hoc analysis of regions of interest identified by whole-brain assessments. We illustrate an implementation of the technique in the statistical software packages R and SAS. VOI timetrends are extracted from conventionally preprocessed fMRI images. A timetrend of average signal intensity across the VOI during the scanning period is calculated for each subject. The values are scaled relative to baseline periods, and time points are binned. In SAS, the procedure PROC MIXED implements the RMANOVA in a single step. In R, we present one option for implementing RMANOVA with the mixed model function “lme”. Model diagnostics, and predicted means and differences are best performed with additional libraries and commands in R; we present one example. The ensuing results allow determination of significant overall effects, and time-point specific within- and between-group responses relative to baseline. We illustrate the technique using fMRI data from two groups of subjects who underwent a respiratory challenge. RMANOVA allows insight into the timing of responses and response differences between groups, and so is suited to physiologic testing paradigms eliciting complex response patterns

  2. Detecting variable responses in time-series using repeated measures ANOVA: Application to physiologic challenges.

    PubMed

    Macey, Paul M; Schluter, Philip J; Macey, Katherine E; Harper, Ronald M

    2016-01-01

    We present an approach to analyzing physiologic timetrends recorded during a stimulus by comparing means at each time point using repeated measures analysis of variance (RMANOVA). The approach allows temporal patterns to be examined without an a priori model of expected timing or pattern of response. The approach was originally applied to signals recorded from functional magnetic resonance imaging (fMRI) volumes-of-interest (VOI) during a physiologic challenge, but we have used the same technique to analyze continuous recordings of other physiological signals such as heart rate, breathing rate, and pulse oximetry. For fMRI, the method serves as a complement to whole-brain voxel-based analyses, and is useful for detecting complex responses within pre-determined brain regions, or as a post-hoc analysis of regions of interest identified by whole-brain assessments. We illustrate an implementation of the technique in the statistical software packages R and SAS. VOI timetrends are extracted from conventionally preprocessed fMRI images. A timetrend of average signal intensity across the VOI during the scanning period is calculated for each subject. The values are scaled relative to baseline periods, and time points are binned. In SAS, the procedure PROC MIXED implements the RMANOVA in a single step. In R, we present one option for implementing RMANOVA with the mixed model function "lme". Model diagnostics, and predicted means and differences are best performed with additional libraries and commands in R; we present one example. The ensuing results allow determination of significant overall effects, and time-point specific within- and between-group responses relative to baseline. We illustrate the technique using fMRI data from two groups of subjects who underwent a respiratory challenge. RMANOVA allows insight into the timing of responses and response differences between groups, and so is suited to physiologic testing paradigms eliciting complex response patterns. PMID

  3. Speech task and timing considerations in MRI research

    NASA Astrophysics Data System (ADS)

    Epstein, Melissa A.; Stone, Maureen

    2003-04-01

    In order to create dynamic magnetic resonance images, subjects must repeat tokens as much as 30 times in a row, therefore, their precision is critical for image quality. Word repetition rate can be 1 or 1.5 s, and is matched to the rate of image recording. Unlike reciting tokens to the beat of a metronome, subjects must say each token during an extended period of noise that lasts about 75% of the repetition period. Furthermore, some tokens may be more difficult to say repetitively in these conditions. Therefore, this study simulated the acoustics of a MRI recording session to examine the effects of subject, token, and repetition rate on temporal precision. Subjects repeat up to ten mono- to trisyllabic words 30 times each at two repetition rates. Measurements are made of onsets and offsets of one or more phonemes within each word. Preliminary results (five subjects) indicate that there is an effect of subject and word. Further subjects are being measured to corroborate these results and to determine if one repetition rate is better than another and to test subject reliability.

  4. Effect of Repeated Evaluation and Repeated Exposure on Acceptability Ratings of Sentences

    ERIC Educational Resources Information Center

    Zervakis, Jennifer; Mazuka, Reiko

    2013-01-01

    This study investigated the effect of repeated evaluation and repeated exposure on grammatical acceptability ratings for both acceptable and unacceptable sentence types. In Experiment 1, subjects in the Experimental group rated multiple examples of two ungrammatical sentence types (ungrammatical binding and double object with dative-only verb),…

  5. Copy number of tandem direct repeats within the inverted repeats of Marek's disease virus DNA.

    PubMed

    Kanamori, A; Nakajima, K; Ikuta, K; Ueda, S; Kato, S; Hirai, K

    1986-12-01

    We previously reported that DNA of the oncogenic strain BC-1 of Marek's disease virus serotype 1 (MDV1) contains three units of tandem direct repeats with 132 base pair (bp) repeats within the inverted repeats of the long regions of the MDV1 genome, whereas the attenuated, nononcogenic viral DNA contains multiple units of tandem direct repeats (Maotani et al., 1986). In the present study, the difference in the copy numbers of 132 bp repeats of oncogenic and nononcogenic MDV1 DNAs in other strains of MDV1 was investigated by Southern blot hybridization. The main copy numbers in different oncogenic MDV1 strains differed: those of BC-1, JM and highly oncogenic Md5 were 3, 5 to 12 and 2, respectively. The viral DNA population with two units of repeats was small, but detectable, in cells infected with either the oncogenic BC-1 or JM strain. The MDV1 DNA in various MD cell lines contained either two units or both two and three units of repeats. The significance of the copy number of repeats in oncogenicity of MDV1 is discussed.

  6. Portable MRI developed at Los Alamos

    SciTech Connect

    Espy, Michelle

    2015-04-22

    Scientists at Los Alamos National Laboratory are developing an ultra-low-field Magnetic Resonance Imaging (MRI) system that could be low-power and lightweight enough for forward deployment on the battlefield and to field hospitals in the World's poorest regions. "MRI technology is a powerful medical diagnostic tool," said Michelle Espy, the Battlefield MRI (bMRI) project leader, "ideally suited for imaging soft-tissue injury, particularly to the brain." But hospital-based MRI devices are big and expensive, and require considerable infrastructure, such as large quantities of cryogens like liquid nitrogen and helium, and they typically use a large amount of energy. "Standard MRI machines just can't go everywhere," said Espy. "Soldiers wounded in battle usually have to be flown to a large hospital and people in emerging nations just don't have access to MRI at all. We've been in contact with doctors who routinely work in the Third World and report that MRI would be extremely valuable in treating pediatric encephalopathy, and other serious diseases in children." So the Los Alamos team started thinking about a way to make an MRI device that could be relatively easy to transport, set up, and use in an unconventional setting. Conventional MRI machines use very large magnetic fields that align the protons in water molecules to then create magnetic resonance signals, which are detected by the machine and turned into images. The large magnetic fields create exceptionally detailed images, but they are difficult and expensive to make. Espy and her team wanted to see if images of sufficient quality could be made with ultra-low-magnetic fields, similar in strength to the Earth's magnetic field. To achieve images at such low fields they use exquisitely sensitive detectors called Superconducting Quantum Interference Devices, or SQUIDs. SQUIDs are among the most sensitive magnetic field detectors available, so interference with the signal is the primary stumbling block. "SQUIDs are

  7. A simple risk stratification model that predicts 1-year postoperative mortality rate in patients with solid-organ cancer

    PubMed Central

    Chou, Wen-Chi; Wang, Frank; Cheng, Yu-Fan; Chen, Miao-Fen; Lu, Chang-Hsien; Wang, Cheng-Hsu; Lin, Yung-Chang; Yeh, Ta-Sen

    2015-01-01

    This study aimed to construct a scoring system developed exclusively from the preoperative data that predicts 1-year postoperative mortality in patients with solid cancers. A total of 20,632 patients who had a curative resection for solid-organ cancers between 2007 and 2012 at Chang Gung Memorial Hospital Linkou Medical Center were included in the derivation cohort. Multivariate logistic regression analysis was performed to develop a risk model that predicts 1-year postoperative mortality. Patients were then stratified into four risk groups (low-, intermediate-, high-, and very high-risk) according to the total score (0–43) form mortality risk analysis. An independent cohort of 16,656 patients who underwent curative cancer surgeries at three other hospitals during the same study period (validation cohort) was enrolled to verify the risk model. Age, gender, cancer site, history of previous cancer, tumor stage, Charlson comorbidity index, American Society of Anesthesiologist score, admission type, and Eastern Cooperative Oncology Group performance status were independently predictive of 1-year postoperative mortality. The 1-year postoperative mortality rates were 0.5%, 3.8%, 14.6%, and 33.8%, respectively, among the four risk groups in the derivation cohort (c-statistic, 0.80), compared with 0.9%, 4.2%, 14.6%, and 32.6%, respectively, in the validation cohort (c-statistic, 0.78). The risk stratification model also demonstrated good discrimination of long-term survival outcome of the four-tier risk groups (P < 0.01 for both cohorts). The risk stratification model not only predicts 1-year postoperative mortality but also differentiates long-term survival outcome between the risk groups. PMID:26311149

  8. A simple risk stratification model that predicts 1-year postoperative mortality rate in patients with solid-organ cancer.

    PubMed

    Chou, Wen-Chi; Wang, Frank; Cheng, Yu-Fan; Chen, Miao-Fen; Lu, Chang-Hsien; Wang, Cheng-Hsu; Lin, Yung-Chang; Yeh, Ta-Sen

    2015-11-01

    This study aimed to construct a scoring system developed exclusively from the preoperative data that predicts 1-year postoperative mortality in patients with solid cancers. A total of 20,632 patients who had a curative resection for solid-organ cancers between 2007 and 2012 at Chang Gung Memorial Hospital Linkou Medical Center were included in the derivation cohort. Multivariate logistic regression analysis was performed to develop a risk model that predicts 1-year postoperative mortality. Patients were then stratified into four risk groups (low-, intermediate-, high-, and very high-risk) according to the total score (0-43) form mortality risk analysis. An independent cohort of 16,656 patients who underwent curative cancer surgeries at three other hospitals during the same study period (validation cohort) was enrolled to verify the risk model. Age, gender, cancer site, history of previous cancer, tumor stage, Charlson comorbidity index, American Society of Anesthesiologist score, admission type, and Eastern Cooperative Oncology Group performance status were independently predictive of 1-year postoperative mortality. The 1-year postoperative mortality rates were 0.5%, 3.8%, 14.6%, and 33.8%, respectively, among the four risk groups in the derivation cohort (c-statistic, 0.80), compared with 0.9%, 4.2%, 14.6%, and 32.6%, respectively, in the validation cohort (c-statistic, 0.78). The risk stratification model also demonstrated good discrimination of long-term survival outcome of the four-tier risk groups (P < 0.01 for both cohorts). The risk stratification model not only predicts 1-year postoperative mortality but also differentiates long-term survival outcome between the risk groups.

  9. Improvement in insulin sensitivity following a 1-year lifestyle intervention program in viscerally obese men: contribution of abdominal adiposity.

    PubMed

    Borel, Anne-Laure; Nazare, Julie-Anne; Smith, Jessica; Alméras, Natalie; Tremblay, Angelo; Bergeron, Jean; Poirier, Paul; Després, Jean-Pierre

    2012-02-01

    The objectives of the study were to quantify the effect of a 1-year healthy eating-physical activity/exercise lifestyle modification program on insulin sensitivity in viscerally obese men classified according to their glucose tolerance status and to evaluate the respective contributions of changes in body fat distribution vs changes in cardiorespiratory fitness (CRF) to the improvements in indices of plasma glucose/insulin homeostasis. Abdominally obese, dyslipidemic men (waist circumference ≥90 cm, triglycerides ≥1.69 mmol/L, and/or high-density lipoprotein cholesterol <1.03 mmol/L) were recruited. The 1-year intervention/evaluation was completed by 104 men. Body weight, composition, and fat distribution were assessed by dual-energy x-ray absorptiometry/computed tomography. Cardiorespiratory fitness and cardiometabolic risk profile were measured. After 1 year, insulin sensitivity improved in association with decreases in both visceral (VAT) and subcutaneous adiposity (SAT) as well as with the improvement in CRF, regardless of baseline glucose tolerance. Further analyses were performed according to changes in glucose tolerance status: improvement (group I, n = 39), no change (group N, n = 50), or worsening (group W, n = 15) after 1 year. Groups I and N improved their insulin sensitivity and their CRF, whereas group W did not, while losing less VAT than groups I and N. Multiple regressions showed that reduction in VAT was associated with an improvement in homeostasis model assessment of insulin resistance, whereas reduction in SAT was rather associated with improvement of the insulin sensitivity index of Matsuda. Changes in CRF were not independently associated with changes in indices of plasma glucose/insulin homeostasis. A 1-year lifestyle intervention improved plasma glucose/insulin homeostasis in viscerally obese men, including those with normal glucose tolerance status at baseline. Changes in SAT and VAT but not in CRF appeared to mediate these improvements

  10. Massively Parallel MRI Detector Arrays

    PubMed Central

    Keil, Boris; Wald, Lawrence L

    2013-01-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called “ultimate” SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays. PMID:23453758

  11. Combined PET/MRI scanner

    DOEpatents

    Schlyer, David; Woody, Craig L.; Rooney, William; Vaska, Paul; Stoll, Sean; Pratte, Jean-Francois; O'Connor, Paul

    2007-10-23

    A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

  12. Structures of designed armadillo-repeat proteins show propagation of inter-repeat interface effects

    PubMed Central

    Reichen, Christian; Madhurantakam, Chaithanya; Hansen, Simon; Grütter, Markus G.; Plückthun, Andreas; Mittl, Peer R. E.

    2016-01-01

    The armadillo repeat serves as a scaffold for the development of modular peptide-recognition modules. In order to develop such a system, three crystal structures of designed armadillo-repeat proteins with third-generation N-caps (YIII-type), four or five internal repeats (M-type) and second-generation C-caps (AII-type) were determined at 1.8 Å (His-YIIIM4AII), 2.0 Å (His-YIIIM5AII) and 1.95 Å (YIIIM5AII) resolution and compared with those of variants with third-generation C-caps. All constructs are full consensus designs in which the internal repeats have exactly the same sequence, and hence identical conformations of the internal repeats are expected. The N-cap and internal repeats M1 to M3 are indeed extremely similar, but the comparison reveals structural differences in internal repeats M4 and M5 and the C-cap. These differences are caused by long-range effects of the C-cap, contacting molecules in the crystal, and the intrinsic design of the repeat. Unfortunately, the rigid-body movement of the C-terminal part impairs the regular arrangement of internal repeats that forms the putative peptide-binding site. The second-generation C-cap improves the packing of buried residues and thereby the stability of the protein. These considerations are useful for future improvements of an armadillo-repeat-based peptide-recognition system. PMID:26894544

  13. Intra voxel analysis in MRI

    NASA Astrophysics Data System (ADS)

    Ambrosanio, Michele; Baselice, Fabio; Ferraioli, Giampaolo; Pascazio, Vito

    2014-03-01

    A new application of Compressive Sensing (CS) in Magnetic Resonance Imaging (MRI) field is presented. In particular, first results of the Intra Voxel Analysis (IVA) technique are reported. The idea is to exploit CS peculiarities in order to distinguish different contributions inside the same resolution cell, instead of reconstructing images from not fully sampled k-space acquisition. Applied to MRI field, this means the possibility of estimating the presence of different tissues inside the same voxel, i.e. in one pixel of the obtained image. In other words, the method is the first attempt, as far as we know, of achieving Spectroscopy-like results starting from each pixel of MR images. In particular, tissues are distinguished each others by evaluating their spin-spin relaxation times. Within this manuscript, first results on clinical dataset, in particular a phantom made by aqueous solution and oil and an occipital brain lesion corresponding to a metastatic breast cancer nodule, are reported. Considering the phantom dataset, in particular focusing on the slice where the separation between water and oil occurs, the methodology is able to distinguish the two components with different spin-spin relaxation times. With respect to clinical dataset,focusing on a voxel of the lesion area, the approach is able to detect the presence of two tissues, namely the healthy and the cancer related ones, while in other location outside the lesion only the healthy tissue is detected. Of course, these are the first results of the proposed methodology, further studies on different types of clinical datasets are required in order to widely validate the approach. Although few datasets have been considered, results seem both interesting and promising.

  14. Rehabilitative Interventions and Brain Plasticity in Autism Spectrum Disorders: Focus on MRI-Based Studies

    PubMed Central

    Calderoni, Sara; Billeci, Lucia; Narzisi, Antonio; Brambilla, Paolo; Retico, Alessandra; Muratori, Filippo

    2016-01-01

    Clinical and research evidence supports the efficacy of rehabilitative intervention for improving targeted skills or global outcomes in individuals with autism spectrum disorder (ASD). However, putative mechanisms of structural and functional brain changes are poorly understood. This review aims to investigate the research literature on the neural circuit modifications after non-pharmacological intervention. For this purpose, longitudinal studies that used magnetic resonance imaging (MRI)-based techniques at the start and at the end of the trial to evaluate the neural effects of rehabilitative treatment in subjects with ASD were identified. The six included studies involved a limited number of patients in the active group (from 2 to 16), and differed by acquisition method (task-related and resting-state functional MRI) as well as by functional MRI tasks. Overall, the results produced by the selected investigations demonstrated brain plasticity during the treatment interval that results in an activation/functional connectivity more similar to those of subjects with typical development (TD). Repeated MRI evaluation may represent a promising tool for the detection of neural changes in response to treatment in patients with ASD. However, large-scale randomized controlled trials after standardized rehabilitative intervention are required before translating these preliminary results into clinical use. PMID:27065795

  15. Single element ultrasonic imaging of limb geometry: an in-vivo study with comparison to MRI

    NASA Astrophysics Data System (ADS)

    Zhang, Xiang; Fincke, Jonathan R.; Anthony, Brian W.

    2016-04-01

    Despite advancements in medical imaging, current prosthetic fitting methods remain subjective, operator dependent, and non-repeatable. The standard plaster casting method relies on prosthetist experience and tactile feel of the limb to design the prosthetic socket. Often times, many fitting iterations are required to achieve an acceptable fit. Use of improper socket fittings can lead to painful pathologies including neuromas, inflammation, soft tissue calcification, and pressure sores, often forcing the wearer to into a wheelchair and reducing mobility and quality of life. Computer software along with MRI/CT imaging has already been explored to aid the socket design process. In this paper, we explore the use of ultrasound instead of MRI/CT to accurately obtain the underlying limb geometry to assist the prosthetic socket design process. Using a single element ultrasound system, multiple subjects' proximal limbs were imaged using 1, 2.25, and 5 MHz single element transducers. Each ultrasound transducer was calibrated to ensure acoustic exposure within the limits defined by the FDA. To validate image quality, each patient was also imaged in an MRI. Fiducial markers visible in both MRI and ultrasound were used to compare the same limb cross-sectional image for each patient. After applying a migration algorithm, B-mode ultrasound cross-sections showed sufficiently high image resolution to characterize the skin and bone boundaries along with the underlying tissue structures.

  16. MRI visualisation by digitally reconstructed radiographs

    NASA Astrophysics Data System (ADS)

    Serrurier, Antoine; Bönsch, Andrea; Lau, Robert; Deserno, Thomas M.

    2015-03-01

    Visualising volumetric medical images such as computed tomography and magnetic resonance imaging (MRI) on picture archiving and communication systems (PACS) clients is often achieved by image browsing in sagittal, coronal or axial views or three-dimensional (3D) rendering. This latter technique requires fine thresholding for MRI. On the other hand, computing virtual radiograph images, also referred to as digitally reconstructed radiographs (DRR), provides in a single two-dimensional (2D) image a complete overview of the 3D data. It appears therefore as a powerful alternative for MRI visualisation and preview in PACS. This study describes a method to compute DRR from T1-weighted MRI. After segmentation of the background, a histogram distribution analysis is performed and each foreground MRI voxel is labeled as one of three tissues: cortical bone, also known as principal absorber of the X-rays, muscle and fat. An intensity level is attributed to each voxel according to the Hounsfield scale, linearly related to the X-ray attenuation coefficient. Each DRR pixel is computed as the accumulation of the new intensities of the MRI dataset along the corresponding X-ray. The method has been tested on 16 T1-weighted MRI sets. Anterior-posterior and lateral DRR have been computed with reasonable qualities and avoiding any manual tissue segmentations. This proof-of-concept holds for research application for use in clinical PACS.

  17. Low-Cost High-Performance MRI.

    PubMed

    Sarracanie, Mathieu; LaPierre, Cristen D; Salameh, Najat; Waddington, David E J; Witzel, Thomas; Rosen, Matthew S

    2015-01-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5-3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm(3) imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (<10 mT) will complement traditional MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices. PMID:26469756

  18. Low-Cost High-Performance MRI

    NASA Astrophysics Data System (ADS)

    Sarracanie, Mathieu; Lapierre, Cristen D.; Salameh, Najat; Waddington, David E. J.; Witzel, Thomas; Rosen, Matthew S.

    2015-10-01

    Magnetic Resonance Imaging (MRI) is unparalleled in its ability to visualize anatomical structure and function non-invasively with high spatial and temporal resolution. Yet to overcome the low sensitivity inherent in inductive detection of weakly polarized nuclear spins, the vast majority of clinical MRI scanners employ superconducting magnets producing very high magnetic fields. Commonly found at 1.5-3 tesla (T), these powerful magnets are massive and have very strict infrastructure demands that preclude operation in many environments. MRI scanners are costly to purchase, site, and maintain, with the purchase price approaching $1 M per tesla (T) of magnetic field. We present here a remarkably simple, non-cryogenic approach to high-performance human MRI at ultra-low magnetic field, whereby modern under-sampling strategies are combined with fully-refocused dynamic spin control using steady-state free precession techniques. At 6.5 mT (more than 450 times lower than clinical MRI scanners) we demonstrate (2.5 × 3.5 × 8.5) mm3 imaging resolution in the living human brain using a simple, open-geometry electromagnet, with 3D image acquisition over the entire brain in 6 minutes. We contend that these practical ultra-low magnetic field implementations of MRI (<10 mT) will complement traditional MRI, providing clinically relevant images and setting new standards for affordable (<$50,000) and robust portable devices.

  19. Recommendations for Real-Time Speech MRI

    PubMed Central

    Lingala, Sajan Goud; Sutton, Brad P.; Miquel, Marc E.; Nayak, Krishna S.

    2016-01-01

    Real-time magnetic resonance imaging (RT-MRI) is being increasingly used for speech and vocal production research studies. Several imaging protocols have emerged based on advances in RT-MRI acquisition, reconstruction, and audio-processing methods. This review summarizes the state-of-the-art, discusses technical considerations, and provides specific guidance for new groups entering this field. We provide recommendations for performing RT-MRI of the upper airway. This is a consensus statement stemming from the ISMRM-endorsed Speech MRI summit held in Los Angeles, February 2014. A major unmet need identified at the summit was the need for consensus on protocols that can be easily adapted by researchers equipped with conventional MRI systems. To this end, we provide a discussion of tradeoffs in RT-MRI in terms of acquisition requirements, a priori assumptions, artifacts, computational load, and performance for different speech tasks. We provide four recommended protocols and identify appropriate acquisition and reconstruction tools. We list pointers to open-source software that facilitate implementation. We conclude by discussing current open challenges in the methodological aspects of RT-MRI of speech. PMID:26174802

  20. Testing Multiple Outcomes in Repeated Measures Designs

    ERIC Educational Resources Information Center

    Lix, Lisa M.; Sajobi, Tolulope

    2010-01-01

    This study investigates procedures for controlling the familywise error rate (FWR) when testing hypotheses about multiple, correlated outcome variables in repeated measures (RM) designs. A content analysis of RM research articles published in 4 psychology journals revealed that 3 quarters of studies tested hypotheses about 2 or more outcome…

  1. Triggering of repeating earthquakes in central California

    USGS Publications Warehouse

    Wu, Chunquan; Gomberg, Joan; Ben-Naim, Eli; Johnson, Paul

    2014-01-01

    Dynamic stresses carried by transient seismic waves have been found capable of triggering earthquakes instantly in various tectonic settings. Delayed triggering may be even more common, but the mechanisms are not well understood. Catalogs of repeating earthquakes, earthquakes that recur repeatedly at the same location, provide ideal data sets to test the effects of transient dynamic perturbations on the timing of earthquake occurrence. Here we employ a catalog of 165 families containing ~2500 total repeating earthquakes to test whether dynamic perturbations from local, regional, and teleseismic earthquakes change recurrence intervals. The distance to the earthquake generating the perturbing waves is a proxy for the relative potential contributions of static and dynamic deformations, because static deformations decay more rapidly with distance. Clear changes followed the nearby 2004 Mw6 Parkfield earthquake, so we study only repeaters prior to its origin time. We apply a Monte Carlo approach to compare the observed number of shortened recurrence intervals following dynamic perturbations with the distribution of this number estimated for randomized perturbation times. We examine the comparison for a series of dynamic stress peak amplitude and distance thresholds. The results suggest a weak correlation between dynamic perturbations in excess of ~20 kPa and shortened recurrence intervals, for both nearby and remote perturbations.

  2. Blood Donation by Elderly Repeat Blood Donors

    PubMed Central

    Zeiler, Thomas; Lander-Kox, Jutta; Alt, Timo

    2014-01-01

    Summary Background Upper age limits for blood donors are intended to protect elderly blood donors from donor reactions. However, due to a lack of data about adverse reactions in elderly blood donors, upper age limits are arbitrary and vary considerably between different countries. Methods Here we present data from 171,231 voluntary repeat whole blood donors beyond the age of 68 years. Results Blood donations from repeat blood donors beyond the age of 68 years increased from 2,114 in 2005 to 38,432 in 2012 (from 0,2% to 4.2% of all whole blood donations). Adverse donor reactions in repeat donors decreased with age and were lower than in the whole group (0.26%), even in donors older than 71 years (0.16%). However, from the age of 68 years, the time to complete recovery after donor reactions increased. Donor deferrals were highest in young blood donors (21.4%), but increased again in elderly blood donors beyond 71 years (12.6%). Conclusion Blood donation by regular repeat blood donors older than 71 years may be safely continued. However, due to a lack of data for donors older than 75 years, blood donation in these donors should be handled with great caution. PMID:25254019

  3. Epigenetics and Triplet-Repeat Neurological Diseases

    PubMed Central

    Nageshwaran, Sathiji; Festenstein, Richard

    2015-01-01

    The term “junk DNA” has been reconsidered following the delineation of the functional significance of repetitive DNA regions. Typically associated with centromeres and telomeres, DNA repeats are found in nearly all organisms throughout their genomes. Repetitive regions are frequently heterochromatinized resulting in silencing of intrinsic and nearby genes. However, this is not a uniform rule, with several genes known to require such an environment to permit transcription. Repetitive regions frequently exist as dinucleotide, trinucleotide, and tetranucleotide repeats. The association between repetitive regions and disease was emphasized following the discovery of abnormal trinucleotide repeats underlying spinal and bulbar muscular atrophy (Kennedy’s disease) and fragile X syndrome of mental retardation (FRAXA) in 1991. In this review, we provide a brief overview of epigenetic mechanisms and then focus on several diseases caused by DNA triplet-repeat expansions, which exhibit diverse epigenetic effects. It is clear that the emerging field of epigenetics is already generating novel potential therapeutic avenues for this group of largely incurable diseases. PMID:26733936

  4. Epigenetics and Triplet-Repeat Neurological Diseases.

    PubMed

    Nageshwaran, Sathiji; Festenstein, Richard

    2015-01-01

    The term "junk DNA" has been reconsidered following the delineation of the functional significance of repetitive DNA regions. Typically associated with centromeres and telomeres, DNA repeats are found in nearly all organisms throughout their genomes. Repetitive regions are frequently heterochromatinized resulting in silencing of intrinsic and nearby genes. However, this is not a uniform rule, with several genes known to require such an environment to permit transcription. Repetitive regions frequently exist as dinucleotide, trinucleotide, and tetranucleotide repeats. The association between repetitive regions and disease was emphasized following the discovery of abnormal trinucleotide repeats underlying spinal and bulbar muscular atrophy (Kennedy's disease) and fragile X syndrome of mental retardation (FRAXA) in 1991. In this review, we provide a brief overview of epigenetic mechanisms and then focus on several diseases caused by DNA triplet-repeat expansions, which exhibit diverse epigenetic effects. It is clear that the emerging field of epigenetics is already generating novel potential therapeutic avenues for this group of largely incurable diseases. PMID:26733936

  5. A Structured Group Program for Repeat Dieters.

    ERIC Educational Resources Information Center

    McNamara, Kathleen

    1989-01-01

    Describes a structured group program for women who repeatedly diet and may be at risk of developing more serious eating disorders. Discusses sessions focusing on eating behavior as well as internal factors that contribute to low body esteem and food and weight preoccupation. Evaluates effectiveness of program by self-reports of members of two…

  6. Building Fluency through the Repeated Reading Method

    ERIC Educational Resources Information Center

    Cohen, Joshua

    2011-01-01

    For the last two years the author has used Repeated Reading (RR) to teach reading fluency in English as a Foreign Language classrooms in colleges and universities in Japan. RR is a method where the student reads and rereads a text silently or aloud from two to four times to reach a predetermined level of speed, accuracy, and comprehension. RR…

  7. Longer-baseline telescopes using quantum repeaters.

    PubMed

    Gottesman, Daniel; Jennewein, Thomas; Croke, Sarah

    2012-08-17

    We present an approach to building interferometric telescopes using ideas of quantum information. Current optical interferometers have limited baseline lengths, and thus limited resolution, because of noise and loss of signal due to the transmission of photons between the telescopes. The technology of quantum repeaters has the potential to eliminate this limit, allowing in principle interferometers with arbitrarily long baselines. PMID:23006349

  8. Human adaptation to repeated cold immersions.

    PubMed Central

    Golden, F S; Tipton, M J

    1988-01-01

    1. The present investigation was designed to examine human adaptation to intermittent severe cold exposure and to assess the effect of exercise on any adaptation obtained. 2. Sixteen subjects were divided into two equal groups. Each subject performed ten head-out immersions; two into thermoneutral water which was then cooled until they shivered vigorously, and eight into water at 15 degrees C for 40 min. During the majority of the 15 degrees C immersions, one group (dynamic group) exercised whilst the other (static group) rested. 3. Results showed that both groups responded to repeated cold immersions with a reduction in their initial responses to cold. The time course of these reductions varied, however, between responses. 4. Only the static group developed a reduced metabolic response to prolonged resting immersion. 5. It is concluded that repeated resting exposure to cold was the more effective way of producing an adaptation. The performance of exercise during repeated exposure to cold prevented the development of an adaptive reduction in the metabolic response to cold during a subsequent resting immersion. In addition, many of the adaptations obtained during repeated resting exposure were overridden or masked during a subsequent exercising immersion. PMID:3411500

  9. The Differential Effects of Repeating Kindergarten

    ERIC Educational Resources Information Center

    Burkam, David T.; LoGerfo, Laura; Ready, Doug; Lee, Valerie E.

    2007-01-01

    We use the Early Childhood Longitudinal Study to investigate national patterns addressing (a) who repeats kindergarten, and (b) the subsequent cognitive effects of this event. Using OLS regression techniques, we investigate 1st-time kindergartners who are promoted, 1st-time kindergartners who are retained, and children who are already repeating…

  10. Chlorinated hydrocarbons in women with repeated miscarriages.

    PubMed Central

    Gerhard, I; Daniel, V; Link, S; Monga, B; Runnebaum, B

    1998-01-01

    This study was conducted to investigate a possible etiological role of chlorinated hydrocarbons in the pathogenesis of repeated miscarriages. The blood levels of chlorinated hydrocarbons [CHCs: pentachlorophenol, hexachlorocyclohexane, hexachlorobenzene, the dichlorodiphenyltrichloroethane (DDT) group, polychlorinated biphenyls] were determined in 89 women with repeated miscarriages, who were referred to the University Hospital of Obstetrics and Gynecology of Heidelberg for investigations between 1989 and 1993, and compared to a previously investigated reference population. In more than 20% of the women, at least one of the CHC levels exceeded the reference range. CHC levels did not differ significantly between women with primary or secondary and early or late miscarriages; neither did they differ between women with hormonal or immunological disorders as causes of repeated miscarriages or women with idiopathic repeated miscarriages. No significant associations were detected between CHC levels and further conceptions or the outcome of further pregnancies. As significant associations were found between increasing CHC blood concentrations and immunological and hormonal changes, CHCs may have an impact on the pregnancy course in certain cases. PMID:9755145

  11. Repeat abortions in New York City, 2010.

    PubMed

    Toprani, Amita; Cadwell, Betsy L; Li, Wenhui; Sackoff, Judith; Greene, Carolyn; Begier, Elizabeth

    2015-06-01

    This study aims to describe factors associated with the number of past abortions obtained by New York City (NYC) abortion patients in 2010. We calculated rates of first and repeat abortion by age, race/ethnicity, and neighborhood-level poverty and the mean number of self-reported past abortions by age, race/ethnicity, neighborhood-level poverty, number of living children, education, payment method, marital status, and nativity. We used negative binomial regression to predict number of past abortions by patient characteristics. Of the 76,614 abortions reported for NYC residents in 2010, 57% were repeat abortions. Repeat abortions comprised >50% of total abortions among the majority of sociodemographic groups we examined. Overall, mean number of past abortions was 1.3. Mean number of past abortions was higher for women aged 30-34 years (1.77), women with ≥5 children (2.50), and black non-Hispanic women (1.52). After multivariable regression, age, race/ethnicity, and number of children were the strongest predictors of number of past abortions. This analysis demonstrates that, although socioeconomic disparities exist, all abortion patients are at high risk for repeat unintended pregnancy and abortion. PMID:25779755

  12. History repeats itself: genomic divergence in copepods.

    PubMed

    Renaut, Sébastien; Dion-Côté, Anne-Marie

    2016-04-01

    Press stop, erase everything from now till some arbitrary time in the past and start recording life as it evolves once again. Would you see the same tape of life playing itself over and over, or would a different story unfold every time? The late Steven Jay Gould called this experiment replaying the tape of life and argued that any replay of the tape would lead evolution down a pathway radically different from the road actually taken (Gould 1989). This thought experiment has puzzled evolutionary biologists for a long time: how repeatable are evolutionary events? And if history does indeed repeat itself, what are the factors that may help us predict the path taken? A powerful means to address these questions at a small evolutionary scale is to study closely related populations that have evolved independently, under similar environmental conditions. This is precisely what Pereira et al. (2016) set out to do using marine copepods Tigriopus californicus, and present their results in this issue of Molecular Ecology. They show that evolution can be repeatable and even partly predictable, at least at the molecular level. As expected from theory, patterns of divergence were shaped by natural selection. At the same time, strong genetic drift due to small population sizes also constrained evolution down a similar evolutionary road, and probably contributed to repeatable patterns of genomic divergence. PMID:27012819

  13. Y Se Repite = And It Repeats Itself

    ERIC Educational Resources Information Center

    Katzew, Adriana

    2010-01-01

    In this article, the author discusses Y Se Repite [And It Repeats Itself], a project she conceptualized due to the growing number of Latino/a Mexican migrant workers in dairy farms in the state of Vermont. In 2006, approximately 2,000 Latinos/as--most of them undocumented Mexican migrant workers--worked throughout the state's dairy farms, yet…

  14. Repeater For A Digital-Communication Bus

    NASA Technical Reports Server (NTRS)

    Torres-Guzman, Esteban; Olson, Stephen; Heaps, Tim

    1993-01-01

    Digital repeater circuit designed to extend range of communication on MIL-STD-1553 bus beyond original maximum allowable length of 300 ft. Circuit provides two-way communication, one way at time, and conforms to specifications of MIL-STD-1553. Crosstalk and instability eliminated.

  15. The Effect of Repeaters on Equating

    ERIC Educational Resources Information Center

    Kim, HeeKyoung; Kolen, Michael J.

    2010-01-01

    Test equating might be affected by including in the equating analyses examinees who have taken the test previously. This study evaluated the effect of including such repeaters on Medical College Admission Test (MCAT) equating using a population invariance approach. Three-parameter logistic (3-PL) item response theory (IRT) true score and…

  16. Why Do Students Repeat Admissions Tests?

    ERIC Educational Resources Information Center

    Jones, Martha S.

    Attitudes and beliefs about the admissions process, especially the role of standardized testing in admissions, were examined for students who took a standardized admissions test more than once. Their attitudes were compared with those of students who did not repeat the test. About 200 preveterinary students who had taken the Veterinary Aptitude…

  17. A Repeater in the Language Laboratory

    ERIC Educational Resources Information Center

    Griffiths, B. T.

    1969-01-01

    Discusses the feasilility of the use of repeater devices in the language laboratory in order to enable the student to "recapitulate effortlessly and and indefinitely any utterance of any length which is causing him difficulty or is of special interest. (FWB)

  18. Cumulative Intertrial Inhibition in Repeated Visual Search

    ERIC Educational Resources Information Center

    Takeda, Yuji

    2007-01-01

    In the present study the author examined visual search when the items remain visible across trials but the location of the target varies. Reaction times for inefficient search cumulatively increased with increasing numbers of repeated search trials, suggesting that inhibition for distractors carried over successive trials. This intertrial…

  19. Influence of dental materials on dental MRI

    PubMed Central

    Tymofiyeva, O; Vaegler, S; Rottner, K; Boldt, J; Hopfgartner, AJ; Proff, PC; Richter, E-J; Jakob, PM

    2013-01-01

    Objectives: To investigate the potential influence of standard dental materials on dental MRI (dMRI) by estimating the magnetic susceptibility with the help of the MRI-based geometric distortion method and to classify the materials from the standpoint of dMRI. Methods: A series of standard dental materials was studied on a 1.5 T MRI system using spin echo and gradient echo pulse sequences and their magnetic susceptibility was estimated using the geometric method. Measurements on samples of dental materials were supported by in vivo examples obtained in dedicated dMRI procedures. Results: The tested materials showed a range of distortion degrees. The following materials were classified as fully compatible materials that can be present even in the tooth of interest: the resin-based sealer AH Plus® (Dentsply, Maillefer, Germany), glass ionomer cement, gutta-percha, zirconium dioxide and composites from one of the tested manufacturers. Interestingly, composites provided by the other manufacturer caused relatively strong distortions and were therefore classified as compatible I, along with amalgam, gold alloy, gold–ceramic crowns, titanium alloy and NiTi orthodontic wires. Materials, the magnetic susceptibility of which differed from that of water by more than 200 ppm, were classified as non-compatible materials that should not be present in the patient’s mouth for any dMRI applications. They included stainless steel orthodontic appliances and CoCr. Conclusions: A classification of the materials that complies with the standard grouping of materials according to their magnetic susceptibility was proposed and adopted for the purposes of dMRI. The proposed classification can serve as a guideline in future dMRI research. PMID:23610088

  20. MRI-guided focused ultrasound treatments.

    PubMed

    Hynynen, Kullervo

    2010-02-01

    Focused ultrasound (FUS) allows noninvasive focal delivery of energy deep into soft tissues. The focused energy can be used to modify and eliminate tissue for therapeutic purposes while the energy delivery is targeted and monitored using magnetic resonance imaging (MRI). MRI compatible methods to deliver these exposures have undergone rapid development over the past 10 years such that clinical treatments are now routinely performed. This paper will review the current technical and clinical status of MRI-guided focused ultrasound therapy and discuss future research and development opportunities.

  1. Developments in boron magnetic resonance imaging (MRI)

    SciTech Connect

    Schweizer, M.

    1995-11-01

    This report summarizes progress during the past year on maturing Boron-11 magnetic resonance imaging (MRI) methodology for noninvasive determination of BNCT agents (BSH) spatially in time. Three major areas are excerpted: (1) Boron-11 MRI of BSH distributions in a canine intracranial tumor model and the first human glioblastoma patient, (2) whole body Boron-11 MRI of BSH pharmacokinetics in a rat flank tumor model, and (3) penetration of gadolinium salts through the BBB as a function of tumor growth in the canine brain.

  2. MRI findings in Little Leaguer's shoulder.

    PubMed

    Song, James C; Lazarus, Martin L; Song, Alexandra Pae

    2006-02-01

    Little leaguer's shoulder, a stress injury of the proximal humeral physis, should be considered in the differential diagnosis for an adolescent baseball player with shoulder pain, especially if the player is pitching regularly in a competitive environment. While roentgenographs may or may not be helpful, depending on the duration and severity of the injury, we report the MRI appearance of a case of little leaguer's shoulder. We found MRI helpful in diagnosing injury to the growth plate that was radiographically occult; furthermore, we were able to document the patient's progress with a follow-up MRI examination, which showed improvement with treatment.

  3. MRI findings in pediatric patients with scurvy.

    PubMed

    Gulko, Edwin; Collins, Lee K; Murphy, Robyn C; Thornhill, Beverly A; Taragin, Benjamin H

    2015-02-01

    In modern times scurvy is a rarely encountered disease caused by ascorbic acid (vitamin C) deficiency. However, sporadic cases of scurvy persist, particularly within the pediatric population. Recent individual case reports highlight an increased incidence of scurvy among patients with autism or developmental delay, with isolated case reports detailing the magnetic resonance imaging (MRI) findings of scurvy in these pediatric populations. We present the MRI findings of scurvy in four patients with autism or developmental delay, and review the literature on MRI findings in pediatric patients with scurvy. Despite its rarity, the radiologist must consider scurvy in a pediatric patient with a restricted diet presenting with arthralgia or myalgia. PMID:25109378

  4. MRI findings in pediatric patients with scurvy.

    PubMed

    Gulko, Edwin; Collins, Lee K; Murphy, Robyn C; Thornhill, Beverly A; Taragin, Benjamin H

    2015-02-01

    In modern times scurvy is a rarely encountered disease caused by ascorbic acid (vitamin C) deficiency. However, sporadic cases of scurvy persist, particularly within the pediatric population. Recent individual case reports highlight an increased incidence of scurvy among patients with autism or developmental delay, with isolated case reports detailing the magnetic resonance imaging (MRI) findings of scurvy in these pediatric populations. We present the MRI findings of scurvy in four patients with autism or developmental delay, and review the literature on MRI findings in pediatric patients with scurvy. Despite its rarity, the radiologist must consider scurvy in a pediatric patient with a restricted diet presenting with arthralgia or myalgia.

  5. Functional imaging of olfaction by CBV fMRI in monkeys: insight into the role of olfactory bulb in habituation.

    PubMed

    Zhao, Fuqiang; Holahan, Marie A; Houghton, Andrea K; Hargreaves, Richard; Evelhoch, Jeffrey L; Winkelmann, Christopher T; Williams, Donald S

    2015-02-01

    Cerebral blood volume (CBV) fMRI with superparamagnetic iron oxide nanoparticles (USPIO) as contrast agent was used to investigate the odorant-induced olfaction in anesthetized rhesus monkeys. fMRI data were acquired in 24 axial slices covering the entire brain, with isoamyl-acetate as the odor stimulant. For each experiment, multiple fMRI measurements were made during a 1- or 2-h period, with each measurement consisting of a baseline period, a stimulation period, and a recovery period. Three different stimulation paradigms with a stimulation period of 1 min, 2 min, or 8 min, respectively, were used to study the olfactory responses in the olfactory bulb (OB). Odorant-induced CBV increases were observed in the OB of each individual monkey. The spatial and temporal activation patterns were reproducible within and between animals. The sensitivity of CBV fMRI in OB was comparable with the sensitivities reported in previous animal fMRI studies. The CBV responses during the 1-min, 2-min, or 8-min odor stimulation period were relatively stable, and did not show attenuation. The amplitudes of CBV response to the repeated stimuli during the 1- or 2-h period were also stable. The stable CBV response in the OB to both continuous and repeated odor stimuli suggests that the OB may not play a major role in olfactory habituation. The technical approach described in this report can enable more extensive fMRI studies of olfactory processing in OB of both humans and non-human primates. PMID:25498426

  6. Temporal filtering of event-related fMRI data using cross-validation.

    PubMed

    Ngan, S C; LaConte, S M; Hu, X

    2000-06-01

    To circumvent the problem of low signal-to-noise ratio (SNR) in event-related fMRI data, the fMRI experiment is typically designed to consist of repeated presentations of the stimulus and measurements of the response, allowing for subsequent averaging of the resulting data. Due to factors such as time limitation, subject motion, habituation, and fatigue, practical constraints on the number of repetitions exist. Thus, filtering is commonly applied to further improve the SNR of the averaged data. Here, a time-varying filter based on theoretical work by Nowak is employed. This filter operates under the stationary wavelet transform framework and is demonstrated to lead to good estimates of the true signals in simulated data. The utility of the filter is also shown using experimental data obtained with a visual-motor paradigm.

  7. Measurement of articular cartilage thickness using a three-dimensional image reconstructed from B-mode ultrasonography mechanical scans feasibility study by comparison with MRI-derived data.

    PubMed

    Ohashi, Satoru; Ohnishi, Isao; Matsumoto, Takuya; Bessho, Masahiko; Matsuyama, Juntaro; Tobita, Kenji; Kaneko, Masako; Nakamura, Kozo

    2012-03-01

    The present study aimed to develop a method to measure three-dimensional (3-D) thickness of cartilage (Tc) at the femoral condyle using B-mode ultrasonography (US) and to clarify the feasibility of US in clinical evaluations of articular cartilage by comparing the results with 3-D measurement values using magnetic resonance imaging (MRI) and assessing repeatability. The medial surface of the right knees of two healthy male volunteers (age, 37 and 59 years) and the knees on affected side of three male patients with osteoarthritis (OA) (age, 73, 81 and 83 years) were scanned using B-mode US with the knee flexed at 120°. The range of the angle of probe rotation for the arm was 0-80° and B-mode images (total, 101 images) were acquired every 0.8°. MRI of the knees was also performed using the double echo steady-state sequence. Both US and MRI images were used to create 3-D models of medial femoral condyle articular cartilage. Tc was determined at points 1 mm apart from one another in the US model (Tc-US) and MRI model (Tc-MRI). Tc-US was compared with Tc-MRI and the repeatability of Tc-US was assessed by mean Tc in the specific region of interest of the femoral condyle. Tc-US correlated significantly with Tc-MRI both in volunteers and in OA patients (p < 0.0001 each) and coefficients of correlation were 0.976 and 0.964 for volunteers and OA patients, respectively. The coefficient of variance for mean Tc-US was 4.90%. Our results show that 3-D US measurements of femoral cartilage are reproducible and correlate strongly with MRI measurements.

  8. SU-D-18C-01: A Novel 4D-MRI Technology Based On K-Space Retrospective Sorting

    SciTech Connect

    Liu, Y; Yin, F; Cai, J

    2014-06-01

    Purpose: Current 4D-MRI techniques lack sufficient temporal/spatial resolution and consistent tumor contrast. To overcome these limitations, this study presents the development and initial evaluation of an entirely new framework of 4D-MRI based on k-space retrospective sorting. Methods: An important challenge of the proposed technique is to determine the number of repeated scans(NR) required to obtain sufficient k-space data for 4D-MRI. To do that, simulations using 29 cancer patients' respiratory profiles were performed to derive the relationship between data acquisition completeness(Cp) and NR, also relationship between NR(Cp=95%) and the following factors: total slice(NS), respiratory phase bin length(Lb), frame rate(fr), resolution(R) and image acquisition starting-phase(P0). To evaluate our technique, a computer simulation study on a 4D digital human phantom (XCAT) were conducted with regular breathing (fr=0.5Hz; R=256×256). A 2D echo planer imaging(EPI) MRI sequence were assumed to acquire raw k-space data, with respiratory signal and acquisition time for each k-space data line recorded simultaneously. K-space data was re-sorted based on respiratory phases. To evaluate 4D-MRI image quality, tumor trajectories were measured and compared with the input signal. Mean relative amplitude difference(D) and cross-correlation coefficient(CC) are calculated. Finally, phase-sharing sliding window technique was applied to investigate the feasibility of generating ultra-fast 4D-MRI. Result: Cp increased with NR(Cp=100*[1-exp(-0.19*NR)], when NS=30, Lb=100%/6). NR(Cp=95%) was inversely-proportional to Lb (r=0.97), but independent of other factors. 4D-MRI on XCAT demonstrated highly accurate motion information (D=0.67%, CC=0.996) with much less artifacts than those on image-based sorting 4D-MRI. Ultra-fast 4D-MRI with an apparent temporal resolution of 10 frames/second was reconstructed using the phase-sharing sliding window technique. Conclusions: A novel 4D-MRI

  9. 47 CFR 80.1179 - On-board repeater limitations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false On-board repeater limitations. 80.1179 Section... On-board repeater limitations. When an on-board repeater is used, the following limitations must be met: (a) The on-board repeater antenna must be located no higher than 3 meters (10 feet) above...

  10. Undescended testes: incidence in 1,002 consecutive male infants and outcome at 1 year of age.

    PubMed

    Thong, M; Lim, C; Fatimah, H

    1998-01-01

    In a study of 1,002 consecutive Malaysian male newborns, 48 (4.8%) were found to have undescended testes (UDT). The rate and laterality of the UDT were associated with lower birth weight (P < 0.001) and prematurity (P < 0.001). Boys with UDT were also more likely to have other congenital abnormalities of the external genitalia, the commonest being hydrocele. No correlation between UDT and maternal age, birth order, social class, or mode of delivery was demonstrated in this study. Although 26/34 (76.5%) of UDT achieved full spontaneous descent by 1 year of age, 1.1% of all infants whose testes remained undescended required regular long-term follow-up with surgical referral and correction at an appropriate time. A premature infant with UDT is more likely to achieve full testicular descent at 1 year of age than a term infant. PMID:9391202

  11. Epigenetic Analysis of Neurocognitive Development at 1 year of Age in a Community-Based Pregnancy Cohort

    PubMed Central

    Murphy, Laura E.; Palmer, Frederick B.; Graff, J. Carolyn; Sutter, Thomas R.; Mozhui, Khyobeni; Hovinga, Collin A.; Thomas, Fridtjof; Park, Vicki; Tylavsky, Frances A.; Adkins, Ronald M.

    2014-01-01

    Multiple studies show that molecular genetic changes and epigenetic modifications affect the risk of cognitive disability or impairment. However, the role of epigenetic variation in cognitive development of neurotypical young children remains largely unknown. Using data from a prospective, community-based study of mother-infant pairs, we investigated the association of DNA methylation patterns in neonatal umbilical cord blood with cognitive and language development at 1 year of age. No CpG loci achieved genome-wide significance, although a small number of weakly suggestive associations with Bayley-III Receptive Communication scales were noted. While umbilical cord blood is a convenient resource for genetic analyses of birth outcomes, our results do not provide conclusive evidence that its use for DNA methylation profiling yields epigenetic markers that are directly related to postnatal neurocognitive outcomes at 1 year of age. PMID:24452678

  12. Emergency contraception with a Copper IUD or oral levonorgestrel: an observational study of 1-year pregnancy rates

    PubMed Central

    Turok, David K.; Jacobson, Janet C.; Dermish, Amna I.; Simonsen, Sara E.; Gurtcheff, Shawn; McFadden, Molly; Murphy, Patricia A.

    2014-01-01

    Objective We investigated the one-year pregnancy rates for emergency contraception (EC) users who selected the copper T380 IUD or oral levonorgestrel (LNG) for EC. Study Design This prospective study followed women for 1 year after choosing either the copper T380 IUD or oral LNG for EC. The study was powered to detect a 6% difference in pregnancy rates within the year after presenting for EC. Results Of the 542 women who presented for EC, agreed to participate in the trial, and meet inclusion criteria, 215 (40%) chose the copper IUD and 327 (60%) chose oral LNG. In the IUD group, 127 (59%) were nulligravid. IUD insertion failed in 42 women (19%). The 1-year follow-up rate was 443/542 (82%); 64% of IUD users contacted at 1 year still had their IUDs in place. The 1-year cumulative pregnancy rate in women choosing the IUD was 6.5% vs. 12.2% in those choosing oral LNG (HR= 0.53, 95% CI: 0.29–0.97, p=0.041). By type of EC method actually received, corresponding values were 5.2% for copper IUD users vs. 12.3% for oral LNG users, HR 0.42 (95% CI: 0.20–0.85, p= 0.017). A multivariable logistic regression model controlling for demographic variables demonstrates that women who chose the IUD for EC had fewer pregnancies in the following year than those who chose oral LNG (HR 0.50, 95% CI: 0.26–0.96, p=0.037). Conclusion One year after presenting for EC women choosing the copper IUD for EC were half as likely to have a pregnancy compared to those choosing oral LNG. PMID:24332433

  13. Prevalence, Course, Incidence, and 1-Year Prediction of Deliberate Self-Harm and Suicide Attempts in Early Norwegian School Adolescents

    ERIC Educational Resources Information Center

    Larsson, Bo; Sund, Anne Mari

    2008-01-01

    In this survey of early Norwegian school adolescents, the prevalence, course, and incidence of self-harm behavior with or without suicide intent were examined, in addition to predictors of self-harm for a 1-year follow-up period. Lifetime prevalence rates of self-harm without suicide intent and suicide attempts were 2.9% and 3.0%, respectively,…

  14. BOLD fMRI in awake prairie voles: A platform for translational social and affective neuroscience.

    PubMed

    Yee, J R; Kenkel, W M; Kulkarni, P; Moore, K; Perkeybile, A M; Toddes, S; Amacker, J A; Carter, C S; Ferris, C F

    2016-09-01

    The advancement of neuroscience depends on continued improvement in methods and models. Here, we present novel techniques for the use of awake functional magnetic resonance imaging (fMRI) in the prairie vole (Microtus ochrogaster) - an important step forward in minimally-invasive measurement of neural activity in a non-traditional animal model. Imaging neural responses in prairie voles, a species studied for its propensity to form strong and selective social bonds, is expected to greatly advance our mechanistic understanding of complex social and affective processes. The use of ultra-high-field fMRI allows for recording changes in region-specific activity throughout the entire brain simultaneously and with high temporal and spatial resolutions. By imaging neural responses in awake animals, with minimal invasiveness, we are able to avoid the confound of anesthesia, broaden the scope of possible stimuli, and potentially make use of repeated scans from the same animals. These methods are made possible by the development of an annotated and segmented 3D vole brain atlas and software for image analysis. The use of these methods in the prairie vole provides an opportunity to broaden neuroscientific investigation of behavior via a comparative approach, which highlights the ethological relevance of pro-social behaviors shared between voles and humans, such as communal breeding, selective social bonds, social buffering of stress, and caregiving behaviors. Results using these methods show that fMRI in the prairie vole is capable of yielding robust blood oxygen level dependent (BOLD) signal changes in response to hypercapnic challenge (inhaled 5% CO2), region-specific physical challenge (unilateral whisker stimulation), and presentation of a set of novel odors. Complementary analyses of repeated restraint sessions in the imaging hardware suggest that voles do not require acclimation to this procedure. Taken together, awake vole fMRI represents a new arena of neurobiological

  15. Prolonged repeated acupuncture stimulation induces habituation effects in pain-related brain areas: an FMRI study.

    PubMed

    Li, Chuanfu; Yang, Jun; Park, Kyungmo; Wu, Hongli; Hu, Sheng; Zhang, Wei; Bu, Junjie; Xu, Chunsheng; Qiu, Bensheng; Zhang, Xiaochu

    2014-01-01

    Most previous studies of brain responses to acupuncture were designed to investigate the acupuncture instant effect while the cumulative effect that should be more important in clinical practice has seldom been discussed. In this study, the neural basis of the acupuncture cumulative effect was analyzed. For this experiment, forty healthy volunteers were recruited, in which more than 40 minutes of repeated acupuncture stimulation was implemented at acupoint Zhusanli (ST36). Three runs of acupuncture fMRI datasets were acquired, with each run consisting of two blocks of acupuncture stimulation. Besides general linear model (GLM) analysis, the cumulative effects of acupuncture were analyzed with analysis of covariance (ANCOVA) to find the association between the brain response and the cumulative duration of acupuncture stimulation in each stimulation block. The experimental results showed that the brain response in the initial stage was the strongest although the brain response to acupuncture was time-variant. In particular, the brain areas that were activated in the first block and the brain areas that demonstrated cumulative effects in the course of repeated acupuncture stimulation overlapped in the pain-related areas, including the bilateral middle cingulate cortex, the bilateral paracentral lobule, the SII, and the right thalamus. Furthermore, the cumulative effects demonstrated bimodal characteristics, i.e. the brain response was positive at the beginning, and became negative at the end. It was suggested that the cumulative effect of repeated acupuncture stimulation was consistent with the characteristic of habituation effects. This finding may explain the neurophysiologic mechanism underlying acupuncture analgesia.

  16. A longitudinal, event-related potential pilot study of adult obsessive-compulsive disorder with 1-year follow-up

    PubMed Central

    Yamamuro, Kazuhiko; Okada, Koji; Kishimoto, Naoko; Ota, Toyosaku; Iida, Junzo; Kishimoto, Toshifumi

    2016-01-01

    Aim Earlier brain imaging research studies have suggested that brain abnormalities in obsessive-compulsive disorder (OCD) normalize as clinical symptoms improve. However, although many studies have investigated event-related potentials (ERPs) in patients with OCD compared with healthy control subjects, it is currently unknown whether ERP changes reflect pharmacological and psychotherapeutic effects. As such, the current study examined the neurocognitive components of OCD to elucidate the pathophysiological abnormalities involved in the disorder, including the frontal-subcortical circuits. Methods The Yale-Brown Obsessive-Compulsive Scale was used to evaluate 14 adult patients with OCD. The present study also included ten age-, sex-, and IQ-matched controls. The P300 and mismatch negativity (MMN) components during an auditory oddball task at baseline for both groups and after 1 year of treatment for patients with OCD were measured. Results Compared with controls, P300 amplitude was attenuated in the OCD group at Cz and C4 at baseline. Pharmacotherapy and psychotherapy treatment for 1 year reduced OCD symptomology. P300 amplitude after 1 year of treatment was significantly increased, indicating normalization compared with baseline at Fz, Cz, C3, and C4. We found no differences in P300 latency, MMN amplitude, or MMN latency between baseline and after one year of treatment. Conclusion ERPs may be a useful tool for evaluating pharmacological and cognitive behavioral therapy in adult patients with OCD. PMID:27713631

  17. Identifying high-school dance students who will develop an eating disorder: a 1-year prospective study.

    PubMed

    Tseng, Mei-Chih Meg; Fang, David; Chang, Chin-Hao; Lee, Ming-Been

    2013-10-30

    This study examined the changes in eating disorder (ED) status over 1 year and identified risk factors for EDs among female dance students. In 2003, all students enrolled in each of the nation's 12 high schools with gifted dance programs participated in a two-phase survey. The same participants were invited to take part in a follow-up survey 1 year later. In all, 583 persons completed the phase 1 questionnaire survey, and 245 persons completed interviews twice at baseline and follow-up. Thirty-five females had a newly developed ED, and less than half of the ED cases found at baseline had recovered at follow-up. Being a grade 12 student carried a reduced risk of EDs, whereas higher baseline scores on the Bulimic Investigatory Test Edinburgh (BITE) increased risks of developing an ED after 1 year. A 10-item BITE questionnaire validly identified girl dance students who would develop EDs later in high school. EDs were more commonly developed during middle adolescence, and we suggest that prevention work against EDs begin in this period among the dance student population. The brief screening questionnaire might help detect intervention targets of a prevention program among adolescent dance students.

  18. Gray matter myelination of 1555 human brains using partial volume corrected MRI images

    PubMed Central

    Shafee, Rebecca; Buckner, Randy L.; Fischl, Bruce

    2014-01-01

    The myelin content of the cortex changes over the human lifetime and aberrant cortical myelination is associated with diseases such as schizophrenia and multiple sclerosis. Recently magnetic resonance imaging (MRI) techniques have shown potential in differentiating between myeloarchitectonically distinct cortical regions in vivo. Here we introduce a new algorithm for correcting partial volume effects present in mm-scale MRI images which was used to investigate the myelination pattern of the cerebral cortex in 1555 clinically normal subjects using the ratio of T1-weighted (T1w) and T2-weighted (T2w) MRI images. A significant linear cross-sectional age increase in T1w/T2w estimated myelin was detected across an 18 to 35 year age span (highest value of ~ 1%/year compared to mean T1w/T2w myelin value at 18 years). The cortex was divided at mid-thickness and the value of T1w/T2w myelin calculated for the inner and the outer layers separately. The increase in T1w/T2w estimated myelin occurs predominantly in the inner layer for most cortical regions. The ratio of the inner and outer layer T1w/T12w myelin was further validated using high-resolution in vivo MRI scans and also a high-resolution MRI scan of a postmortem brain. Additionally, the relationships between cortical thickness, curvature and T1w/T2w estimated myelin were found to be significant, although the relationships varied across the cortex. We discuss these observations as well as limitations of using the T1w/T2w ratio as an estimate of cortical myelin. PMID:25449739

  19. MRI volumetry of prefrontal cortex

    NASA Astrophysics Data System (ADS)

    Sheline, Yvette I.; Black, Kevin J.; Lin, Daniel Y.; Pimmel, Joseph; Wang, Po; Haller, John W.; Csernansky, John G.; Gado, Mokhtar; Walkup, Ronald K.; Brunsden, Barry S.; Vannier, Michael W.

    1995-05-01

    Prefrontal cortex volumetry by brain magnetic resonance (MR) is required to estimate changes postulated to occur in certain psychiatric and neurologic disorders. A semiautomated method with quantitative characterization of its performance is sought to reliably distinguish small prefrontal cortex volume changes within individuals and between groups. Stereological methods were tested by a blinded comparison of measurements applied to 3D MR scans obtained using an MPRAGE protocol. Fixed grid stereologic methods were used to estimate prefrontal cortex volumes on a graphic workstation, after the images are scaled from 16 to 8 bits using a histogram method. In addition images were resliced into coronal sections perpendicular to the bicommissural plane. Prefrontal cortex volumes were defined as all sections of the frontal lobe anterior to the anterior commissure. Ventricular volumes were excluded. Stereological measurement yielded high repeatability and precision, and was time efficient for the raters. The coefficient of error was repeatable measurements. Small frontal lobe volume reductions in patients with brain disorders such as depression and schizophrenia can be efficiently assessed using this method.

  20. Cranial MRI in neonatal hypernatraemic dehydration.

    PubMed

    Korkmaz, A; Yiğit, S; Firat, M; Oran, O

    2000-05-01

    Severe neonatal hypernatraemia is a life-threatening electrolyte disorder because of its neurological complications. These are brain oedema, intracranial haemorrhages, haemorrhagic infarcts and thromboses. There are few reports concerning the radiological findings in the central nervous system in severe neonatal hypernatraemia. Cranial MRI findings in hypernatraemia have been reported in an older child, but have not been described in newborn infants. We report the cranial MRI findings in a newborn infant with acute renal failure and severe hypernatraemia.

  1. Infantile Refsum disease: serial evaluation with MRI.

    PubMed

    Cakirer, Sinan; Savas, Mahmut R

    2005-02-01

    Refsum disease is a rare metabolic disorder, which is characterized by the accumulation of phytanic acid in the blood and tissues, including the brain. A variant of this condition that occurs in young children is called infantile Refsum disease. The MRI findings of symmetrical signal change involving the corticospinal tracts, cerebellar dentate nuclei, and corpus callosum are characteristic. We report the serial MRI findings of a child with this rare metabolic disorder.

  2. MRI and MRS of human brain tumors.

    PubMed

    Hou, Bob L; Hu, Jiani

    2009-01-01

    The purpose of this chapter is to provide an introduction to magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) of human brain tumors, including the primary applications and basic terminology involved. Readers who wish to know more about this broad subject should seek out the referenced books (1. Tofts (2003) Quantitative MRI of the brain. Measuring changes caused by disease. Wiley; Bradley and Stark (1999) 2. Magnetic resonance imaging, 3rd Edition. Mosby Inc; Brown and Semelka (2003) 3. MRI basic principles and applications, 3rd Edition. Wiley-Liss) or reviews (4. Top Magn Reson Imaging 17:127-36, 2006; 5. JMRI 24:709-724, 2006; 6. Am J Neuroradiol 27:1404-1411, 2006).MRI is the most popular means of diagnosing human brain tumors. The inherent difference in the magnetic resonance (MR) properties of water between normal tissues and tumors results in contrast differences on the image that provide the basis for distinguishing tumors from normal tissues. In contrast to MRI, which provides spatial maps or images using water signals of the tissues, proton MRS detects signals of tissue metabolites. MRS can complement MRI because the observed MRS peaks can be linked to inherent differences in biochemical profiles between normal tissues and tumors.The goal of MRI and MRS is to characterize brain tumors, including tumor core, edge, edema, volume, types, and grade. The commonly used brain tumor MRI protocol includes T2-weighted images and T1-weighted images taken both before and after the injection of a contrast agent (typically gadolinium: Gd). The commonly used MRS technique is either point-resolved spectroscopy (PRESS) or stimulated echo acquisition mode (STEAM).

  3. What physics does affect the MRI threshold

    SciTech Connect

    Ilgisonis, V. I.; Lakhin, V. P.; Khalzov, I. V.; Smolyakov, A. I.

    2010-06-16

    Several physical effects, which can considerably decrease the magnetorotational instability (MRI) threshold are discussed. First, we show that MRI features are changed significantly in non-uniform magnetic field. Second, the buoyancy effect is shown to can be destabilizing for azimuthal flow of a resistive plasma. Third, we demonstrate that the rotating fluid may be unstable with respect to non-axisymmetric modes at much lower rotation velocities than with respect to usual symmetric modes.

  4. MRI-powered Actuators for Robotic Interventions

    PubMed Central

    Vartholomeos, Panagiotis; Qin, Lei; Dupont, Pierre E.

    2012-01-01

    This paper presents a novel actuation technology for robotically assisted MRI-guided interventional procedures. Compact and wireless, the actuators are both powered and controlled by the MRI scanner. The design concept and performance limits are described and derived analytically. Simulation and experiments in a clinical MR scanner are used to validate the analysis and to demonstrate the capability of the approach for needle biopsies. The concepts of actuator locking mechanisms and multi-axis control are also introduced. PMID:22287082

  5. Repeated interactions in open quantum systems

    SciTech Connect

    Bruneau, Laurent; Joye, Alain; Merkli, Marco

    2014-07-15

    Analyzing the dynamics of open quantum systems has a long history in mathematics and physics. Depending on the system at hand, basic physical phenomena that one would like to explain are, for example, convergence to equilibrium, the dynamics of quantum coherences (decoherence) and quantum correlations (entanglement), or the emergence of heat and particle fluxes in non-equilibrium situations. From the mathematical physics perspective, one of the main challenges is to derive the irreversible dynamics of the open system, starting from a unitary dynamics of the system and its environment. The repeated interactions systems considered in these notes are models of non-equilibrium quantum statistical mechanics. They are relevant in quantum optics, and more generally, serve as a relatively well treatable approximation of a more difficult quantum dynamics. In particular, the repeated interaction models allow to determine the large time (stationary) asymptotics of quantum systems out of equilibrium.

  6. Overcoming fixation with repeated memory suppression.

    PubMed

    Angello, Genna; Storm, Benjamin C; Smith, Steven M

    2015-01-01

    Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information.

  7. Emergence of Fairness in Repeated Group Interactions

    NASA Astrophysics Data System (ADS)

    Van Segbroeck, S.; Pacheco, J. M.; Lenaerts, T.; Santos, F. C.

    2012-04-01

    Often groups need to meet repeatedly before a decision is reached. Hence, most individual decisions will be contingent on decisions taken previously by others. In particular, the decision to cooperate or not will depend on one’s own assessment of what constitutes a fair group outcome. Making use of a repeated N-person prisoner’s dilemma, we show that reciprocation towards groups opens a window of opportunity for cooperation to thrive, leading populations to engage in dynamics involving both coordination and coexistence, and characterized by cycles of cooperation and defection. Furthermore, we show that this process leads to the emergence of fairness, whose level will depend on the dilemma at stake.

  8. Predictability of repeating earthquakes near Parkfield, California

    NASA Astrophysics Data System (ADS)

    Zechar, J. Douglas; Nadeau, Robert M.

    2012-07-01

    We analyse sequences of repeating microearthquakes that were identified by applying waveform coherency methods to data from the Parkfield High-Resolution Seismic Network. Because by definition all events in a sequence have similar magnitudes and locations, the temporal behaviour of these sequences is naturally isolated, which, coupled with the high occurrence rates of small events, makes these data ideal for studying interevent time distributions. To characterize the temporal predictability of these sequences, we perform retrospective forecast experiments using hundreds of earthquakes. We apply three variants of a simple algorithm that produces sequence-specific, time-varying hazard functions, and we find that the sequences are predictable. We discuss limitations of these data and, more generally, challenges in identifying repeating events, and we outline the potential implications of our results for understanding the occurrence of large earthquakes.

  9. Accumulate-Repeat-Accumulate-Accumulate Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Samuel; Thorpe, Jeremy

    2007-01-01

    Accumulate-repeat-accumulate-accumulate (ARAA) codes have been proposed, inspired by the recently proposed accumulate-repeat-accumulate (ARA) codes. These are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. ARAA codes can be regarded as serial turbolike codes or as a subclass of low-density parity-check (LDPC) codes, and, like ARA codes they have projected graph or protograph representations; these characteristics make it possible to design high-speed iterative decoders that utilize belief-propagation algorithms. The objective in proposing ARAA codes as a subclass of ARA codes was to enhance the error-floor performance of ARA codes while maintaining simple encoding structures and low maximum variable node degree.

  10. Learning with repeated-game strategies.

    PubMed

    Ioannou, Christos A; Romero, Julian

    2014-01-01

    We use the self-tuning Experience Weighted Attraction model with repeated-game strategies as a computer testbed to examine the relative frequency, speed of convergence and progression of a set of repeated-game strategies in four symmetric 2 × 2 games: Prisoner's Dilemma, Battle of the Sexes, Stag-Hunt, and Chicken. In the Prisoner's Dilemma game, we find that the strategy with the most occurrences is the "Grim-Trigger." In the Battle of the Sexes game, a cooperative pair that alternates between the two pure-strategy Nash equilibria emerges as the one with the most occurrences. In the Stag-Hunt and Chicken games, the "Win-Stay, Lose-Shift" and "Grim-Trigger" strategies are the ones with the most occurrences. Overall, the pairs that converged quickly ended up at the cooperative outcomes, whereas the ones that were extremely slow to reach convergence ended up at non-cooperative outcomes. PMID:25126053

  11. Interoperability in encoded quantum repeater networks

    NASA Astrophysics Data System (ADS)

    Nagayama, Shota; Choi, Byung-Soo; Devitt, Simon; Suzuki, Shigeya; Van Meter, Rodney

    2016-04-01

    The future of quantum repeater networking will require interoperability between various error-correcting codes. A few specific code conversions and even a generalized method are known, however, no detailed analysis of these techniques in the context of quantum networking has been performed. In this paper we analyze a generalized procedure to create Bell pairs encoded heterogeneously between two separate codes used often in error-corrected quantum repeater network designs. We begin with a physical Bell pair and then encode each qubit in a different error-correcting code, using entanglement purification to increase the fidelity. We investigate three separate protocols for preparing the purified encoded Bell pair. We calculate the error probability of those schemes between the Steane [[7,1,3

  12. High-bandwidth hybrid quantum repeater.

    PubMed

    Munro, W J; Van Meter, R; Louis, Sebastien G R; Nemoto, Kae

    2008-07-25

    We present a physical- and link-level design for the creation of entangled pairs to be used in quantum repeater applications where one can control the noise level of the initially distributed pairs. The system can tune dynamically, trading initial fidelity for success probability, from high fidelity pairs (F=0.98 or above) to moderate fidelity pairs. The same physical resources that create the long-distance entanglement are used to implement the local gates required for entanglement purification and swapping, creating a homogeneous repeater architecture. Optimizing the noise properties of the initially distributed pairs significantly improves the rate of generating long-distance Bell pairs. Finally, we discuss the performance trade-off between spatial and temporal resources.

  13. Quantum repeater with continuous variable encoding

    NASA Astrophysics Data System (ADS)

    Li, Linshu; Albert, Victor V.; Michael, Marios; Muralidharan, Sreraman; Zou, Changling; Jiang, Liang

    2016-05-01

    Quantum communication enables faithful quantum state transfer between different parties and protocols for cryptographic purposes. However, quantum communication over long distances (>1000km) remains challenging due to optical channel attenuation. This calls for investigation on developing novel encoding schemes that correct photon loss errors efficiently. In this talk, we introduce the generalization of multi-component Schrödinger cat states and propose to encode quantum information in these cat states for ultrafast quantum repeaters. We detail the quantum error correction procedures at each repeater station and characterize the performance of this novel encoding scheme given practical imperfections, such as coupling loss. A comparison with other quantum error correcting codes for bosonic modes will be discussed.

  14. Evolution and recombination of bovine DNA repeats.

    PubMed

    Jobse, C; Buntjer, J B; Haagsma, N; Breukelman, H J; Beintema, J J; Lenstra, J A

    1995-09-01

    The history of the abundant repeat elements in the bovine genome has been studied by comparative hybridization and PCR. The Bov-A and Bov-B SINE elements both emerged just after the divergence of the Camelidae and the true ruminants. A 31-bp subrepeat motif in satellites of the Bovidae species cattle, sheep, and goat is also present in Cervidae (deer) and apparently predates the Bovidae. However, the other components of the bovine satellites were amplified after the divergence of the cattle and the Caprinae (sheep and goat). A 23-bp motif, which as subrepeat of two major satellites occupies 5% of the cattle genome, emerged only after the split of the water buffalo and other cattle species. During the evolution of the Bovidae the satellite repeat units were shaped by recombination events involving subrepeats, other satellite components, and SINE elements. Differences in restriction sites of homologous satellites indicate a continuing rapid horizontal spread of new sequence variants.

  15. Repeatability of Response to Asthma Medications

    PubMed Central

    Wu, Ann; Tantisira, Kelan; Li, Lingling; Schuemann, Brooke; Weiss, Scott

    2010-01-01

    Background Pharmacogenetic studies of drug response in asthma assume that patients respond consistently to a treatment but that treatment response varies across patients, however, no formal studies have demonstrated this. Objective To determine the repeatability of commonly used outcomes for treatment response to asthma medications: bronchodilator response, forced expiratory volume in 1 second (FEV1), and provocative concentration of methacholine producing a 20% decline in FEV1 (PC20). Methods The Childhood Asthma Management Program (CAMP) was a multi-center clinical trial of children randomized to receiving budesonide, nedocromil, or placebo. We determined the intraclass correlation coefficient (ICC) for each outcome over repeated visits over four years in CAMP using mixed effects regression models. We adjusted for the covariates: age, race/ethnicity, height, family income, parental education, and symptom score. We incorporated each outcome for each child as repeated outcome measurements and stratified by treatment group. Results The ICC for bronchodilator response was 0.31 in the budesonide group, 0.35 in the nedocromil group, and 0.40 in the placebo group, after adjusting for covariates. The ICC for FEV1 was 0.71 in the budesonide group, 0.60 in the nedocromil group, and 0.69 in the placebo group, after adjusting for covariates. The ICC for PC20 was 0.67 in the budesonide and placebo groups and 0.73 in the nedocromil group, after adjusting for covariates. Conclusion The within treatment group repeatability of FEV1 and PC20 are high; thus these phenotypes are heritable. FEV1 and PC20 may be better phenotypes than bronchodilator response for studies of treatment response in asthma. PMID:19064281

  16. Automatic-repeat-request error control schemes

    NASA Technical Reports Server (NTRS)

    Lin, S.; Costello, D. J., Jr.; Miller, M. J.

    1983-01-01

    Error detection incorporated with automatic-repeat-request (ARQ) is widely used for error control in data communication systems. This method of error control is simple and provides high system reliability. If a properly chosen code is used for error detection, virtually error-free data transmission can be attained. Various types of ARQ and hybrid ARQ schemes, and error detection using linear block codes are surveyed.

  17. A New Property of Repeating Decimals

    ERIC Educational Resources Information Center

    Arledge, Jane; Tekansik, Sarah

    2008-01-01

    As extended by Ginsberg, Midi's theorem says that if the repeated section of a decimal expansion of a prime is split into appropriate blocks and these are added, the result is a string of nines. We show that if the expansion of 1/p[superscript n+1] is treated the same way, instead of being a string of nines, the sum is related to the period of…

  18. The PRESTO technique for fMRI.

    PubMed

    van Gelderen, P; Duyn, J H; Ramsey, N F; Liu, G; Moonen, C T W

    2012-08-15

    In the early days of BOLD fMRI, the acquisition of T(2)(*) weighted data was greatly facilitated by rapid scan techniques such as EPI. The latter, however, was only available on a few MRI systems that were equipped with specialized hardware that allowed rapid switching of the imaging gradients. For this reason, soon after the invention of fMRI, the scan technique PRESTO was developed to make rapid T(2)(*) weighted scanning available on standard clinical scanners. This method combined echo shifting, which allows for echo times longer than the sequence repetition time, with acquisition of multiple k-space lines per excitation. These two concepts were combined in order to achieve a method fast enough for fMRI, while maintaining a sufficiently long echo time for optimal contrast. PRESTO has been primarily used for 3D scanning, which minimized the contribution of large vessels due to inflow effects. Although PRESTO is still being used today, its appeal has lessened somewhat due to increased gradient performance of modern MRI scanners. Compared to 2D EPI, PRESTO may have somewhat reduced temporal stability, which is a disadvantage for fMRI that may not outweigh the advantage of reduced inflow effects provided by 3D scanning. In this overview, the history of the development of the PRESTO is presented, followed by a qualitative comparison with EPI. PMID:22245350

  19. Diffusion MRI and its role in neuropsychology

    PubMed Central

    Mueller, Bryon A; Lim, Kelvin O; Hemmy, Laura; Camchong, Jazmin

    2015-01-01

    Diffusion Magnetic Resonance Imaging (dMRI) is a popular method used by neuroscientists to uncover unique information about the structural connections within the brain. dMRI is a non-invasive imaging methodology in which image contrast is based on the diffusion of water molecules in tissue. While applicable to many tissues in the body, this review focuses exclusively on the use of dMRI to examine white matter in the brain. In this review, we begin with a definition of diffusion and how diffusion is measured with MRI. Next we introduce the diffusion tensor model, the predominant model used in dMRI. We then describe acquisition issues related to acquisition parameters and scanner hardware and software. Sources of artifacts are then discussed, followed by a brief review of analysis approaches. We provide an overview of the limitations of the traditional diffusion tensor model, and highlight several more sophisticated non-tensor models that better describe the complex architecture of the brain’s white matter. We then touch on reliability and validity issues of diffusion measurements. Finally, we describe examples of ways in which dMRI has been applied to studies of brain disorders and how identified alterations relate to symptomatology and cognition. PMID:26255305

  20. Diffusion MRI and its Role in Neuropsychology.

    PubMed

    Mueller, Bryon A; Lim, Kelvin O; Hemmy, Laura; Camchong, Jazmin

    2015-09-01

    Diffusion Magnetic Resonance Imaging (dMRI) is a popular method used by neuroscientists to uncover unique information about the structural connections within the brain. dMRI is a non-invasive imaging methodology in which image contrast is based on the diffusion of water molecules in tissue. While applicable to many tissues in the body, this review focuses exclusively on the use of dMRI to examine white matter in the brain. In this review, we begin with a definition of diffusion and how diffusion is measured with MRI. Next we introduce the diffusion tensor model, the predominant model used in dMRI. We then describe acquisition issues related to acquisition parameters and scanner hardware and software. Sources of artifacts are then discussed, followed by a brief review of analysis approaches. We provide an overview of the limitations of the traditional diffusion tensor model, and highlight several more sophisticated non-tensor models that better describe the complex architecture of the brain's white matter. We then touch on reliability and validity issues of diffusion measurements. Finally, we describe examples of ways in which dMRI has been applied to studies of brain disorders and how identified alterations relate to symptomatology and cognition.

  1. Advanced flow MRI: emerging techniques and applications.

    PubMed

    Markl, M; Schnell, S; Wu, C; Bollache, E; Jarvis, K; Barker, A J; Robinson, J D; Rigsby, C K

    2016-08-01

    Magnetic resonance imaging (MRI) techniques provide non-invasive and non-ionising methods for the highly accurate anatomical depiction of the heart and vessels throughout the cardiac cycle. In addition, the intrinsic sensitivity of MRI to motion offers the unique ability to acquire spatially registered blood flow simultaneously with the morphological data, within a single measurement. In clinical routine, flow MRI is typically accomplished using methods that resolve two spatial dimensions in individual planes and encode the time-resolved velocity in one principal direction, typically oriented perpendicular to the two-dimensional (2D) section. This review describes recently developed advanced MRI flow techniques, which allow for more comprehensive evaluation of blood flow characteristics, such as real-time flow imaging, 2D multiple-venc phase contrast MRI, four-dimensional (4D) flow MRI, quantification of complex haemodynamic properties, and highly accelerated flow imaging. Emerging techniques and novel applications are explored. In addition, applications of these new techniques for the improved evaluation of cardiovascular (aorta, pulmonary arteries, congenital heart disease, atrial fibrillation, coronary arteries) as well as cerebrovascular disease (intra-cranial arteries and veins) are presented. PMID:26944696

  2. Pediatric multifocal liver lesions evaluated by MRI

    PubMed Central

    Almotairi, Majed; Oudjhane, Kamaldine; Chavhan, Govind B

    2015-01-01

    Objective: The purpose of this study is to present our experience with MRI evaluation of multifocal liver lesions in children and describe the MRI characteristics of these lesions. Patients and Methods: A retrospective review of consecutive MRI exams performed for the evaluation of multiple liver lesions between 1 January 2007 and 31 December 2012 was done to note the number of lesions, the size of the largest lesion, MR signal characteristics, and background liver. Final diagnosis was assigned to each case based on pathology in the available cases and a combination of clinical features, imaging features, and follow-up in the remaining cases. Results: A total of 48 children (22 boys, 26 girls; age between 3 months and 18 years with average age 10.58 years and median age 11 years) were included in the study. Totally 51 lesion diagnoses were seen in 48 children that included 17 focal nodular hyperplasia (FNH), 8 hemangiomas, 7 metastases, 6 regenerative nodules, 3 adenomas, 3 abscesses, and one each of angiomyolipoma, epithelioid hemangioendothelioma, focal fatty infiltration, hepatocellular carcinoma, hepatic infarction, nodular regenerative hyperplasia, and hepatic cyst. Background liver was normal in 33, cirrhotic in 10, fatty in 3, and siderotic in 2 children. Most FNH, hemangiomas, and regenerative nodules showed characteristic MRI features, while metastases were variable in signal pattern. Conclusion: Many commonly seen multifocal liver lesions in children have characteristic MRI features. MRI can help to arrive at reasonable differential diagnoses for multifocal liver lesions in children and guide further investigation and management. PMID:26288526

  3. Agreement and repeatability of an infrared thermometer.

    PubMed

    Kelechi, Teresa J; Good, Angela; Mueller, Martina

    2011-01-01

    Recently, manufacturers have devised thermometers for home use by patients, such as the TempTouch Infrared Thermometer (TTIR; Diabetica Solutions, San Antonio, TX), which is designed with a long handle that can be used for self-monitoring localized skin temperature of the feet and legs. This study assessed the level of agreement and repeatability of the TTIR compared to a thermistor-type thermometer (TT; PeriFlux, 5020 Temperature Unit, Perimed, Stockholm, Sweden), the reference standard. In 17 healthy subjects, localized skin temperature was measured 8 cm above the right medial malleolus at baseline (Time 1), after a 10-minute rest period (Time 2), and after 10 minutes of cold provocation (Time 3) with a cryotherapy gel wrap placed around the lower legs using the TTIR and TT for temperature measurement. Scatter plots and correlation coefficients showed strong positive relationships between the two measurement methods at all three time points (Time 1: r = 0.95; Time 2: r = 0.97; and, Time 3: r = 0.87). Results showed a reasonable level of agreement between the two methods at Times 1 and 2 but not after cold provocation. Agreement between the methods appears to be better than repeatability within each method. Results for repeatability from both the TT and TTIR were very similar suggesting that there was a systematic bias with increasing temperatures between Time 1 and Time 2.

  4. Genomic Repeat Abundances Contain Phylogenetic Signal

    PubMed Central

    Dodsworth, Steven; Chase, Mark W.; Kelly, Laura J.; Leitch, Ilia J.; Macas, Jiří; Novák, Petr; Piednoël, Mathieu; Weiss-Schneeweiss, Hanna; Leitch, Andrew R.

    2015-01-01

    A large proportion of genomic information, particularly repetitive elements, is usually ignored when researchers are using next-generation sequencing. Here we demonstrate the usefulness of this repetitive fraction in phylogenetic analyses, utilizing comparative graph-based clustering of next-generation sequence reads, which results in abundance estimates of different classes of genomic repeats. Phylogenetic trees are then inferred based on the genome-wide abundance of different repeat types treated as continuously varying characters; such repeats are scattered across chromosomes and in angiosperms can constitute a majority of nuclear genomic DNA. In six diverse examples, five angiosperms and one insect, this method provides generally well-supported relationships at interspecific and intergeneric levels that agree with results from more standard phylogenetic analyses of commonly used markers. We propose that this methodology may prove especially useful in groups where there is little genetic differentiation in standard phylogenetic markers. At the same time as providing data for phylogenetic inference, this method additionally yields a wealth of data for comparative studies of genome evolution. PMID:25261464

  5. Genomic repeat abundances contain phylogenetic signal.

    PubMed

    Dodsworth, Steven; Chase, Mark W; Kelly, Laura J; Leitch, Ilia J; Macas, Jiří; Novák, Petr; Piednoël, Mathieu; Weiss-Schneeweiss, Hanna; Leitch, Andrew R

    2015-01-01

    A large proportion of genomic information, particularly repetitive elements, is usually ignored when researchers are using next-generation sequencing. Here we demonstrate the usefulness of this repetitive fraction in phylogenetic analyses, utilizing comparative graph-based clustering of next-generation sequence reads, which results in abundance estimates of different classes of genomic repeats. Phylogenetic trees are then inferred based on the genome-wide abundance of different repeat types treated as continuously varying characters; such repeats are scattered across chromosomes and in angiosperms can constitute a majority of nuclear genomic DNA. In six diverse examples, five angiosperms and one insect, this method provides generally well-supported relationships at interspecific and intergeneric levels that agree with results from more standard phylogenetic analyses of commonly used markers. We propose that this methodology may prove especially useful in groups where there is little genetic differentiation in standard phylogenetic markers. At the same time as providing data for phylogenetic inference, this method additionally yields a wealth of data for comparative studies of genome evolution.

  6. Repeat Stereotactic Radiosurgery for Acoustic Neuromas

    SciTech Connect

    Kano, Hideyuki; Kondziolka, Douglas; Niranjan, Ajay M.Ch.; Flannery, Thomas J.; Flickinger, John C.; Lunsford, L. Dade

    2010-02-01

    Purpose: To evaluate the outcome of repeat stereotactic radiosurgery (SRS) for acoustic neuromas, we assessed tumor control, clinical outcomes, and the risk of adverse radiation effects in patients whose tumors progressed after initial management. Methods and Materials: During a 21-year experience at our center, 1,352 patients underwent SRS as management for their acoustic neuromas. We retrospectively identified 6 patients who underwent SRS twice for the same tumor. The median patient age was 47 years (range, 35-71 years). All patients had imaging evidence of tumor progression despite initial SRS. One patient also had incomplete surgical resection after initial SRS. All patients were deaf at the time of the second SRS. The median radiosurgery target volume at the time of the initial SRS was 0.5 cc and was 2.1 cc at the time of the second SRS. The median margin dose at the time of the initial SRS was 13 Gy and was 11 Gy at the time of the second SRS. The median interval between initial SRS and repeat SRS was 63 months (range, 25-169 months). Results: At a median follow-up of 29 months after the second SRS (range, 13-71 months), tumor control or regression was achieved in all 6 patients. No patient developed symptomatic adverse radiation effects or new neurological symptoms after the second SRS. Conclusions: With this limited experience, we found that repeat SRS for a persistently enlarging acoustic neuroma can be performed safely and effectively.

  7. Accumulate-Repeat-Accumulate-Accumulate-Codes

    NASA Technical Reports Server (NTRS)

    Divsalar, Dariush; Dolinar, Sam; Thorpe, Jeremy

    2004-01-01

    Inspired by recently proposed Accumulate-Repeat-Accumulate (ARA) codes [15], in this paper we propose a channel coding scheme called Accumulate-Repeat-Accumulate-Accumulate (ARAA) codes. These codes can be seen as serial turbo-like codes or as a subclass of Low Density Parity Check (LDPC) codes, and they have a projected graph or protograph representation; this allows for a high-speed iterative decoder implementation using belief propagation. An ARAA code can be viewed as a precoded Repeat-and-Accumulate (RA) code with puncturing in concatenation with another accumulator, where simply an accumulator is chosen as the precoder; thus ARAA codes have a very fast encoder structure. Using density evolution on their associated protographs, we find examples of rate-lJ2 ARAA codes with maximum variable node degree 4 for which a minimum bit-SNR as low as 0.21 dB from the channel capacity limit can be achieved as the block size goes to infinity. Such a low threshold cannot be achieved by RA or Irregular RA (IRA) or unstructured irregular LDPC codes with the same constraint on the maximum variable node degree. Furthermore by puncturing the accumulators we can construct families of higher rate ARAA codes with thresholds that stay close to their respective channel capacity thresholds uniformly. Iterative decoding simulation results show comparable performance with the best-known LDPC codes but with very low error floor even at moderate block sizes.

  8. Identification of repeat structure in large genomes using repeat probability clouds.

    PubMed

    Gu, Wanjun; Castoe, Todd A; Hedges, Dale J; Batzer, Mark A; Pollock, David D

    2008-09-01

    The identification of repeat structure in eukaryotic genomes can be time-consuming and difficult because of the large amount of information ( approximately 3 x 10(9) bp) that needs to be processed and compared. We introduce a new approach based on exact word counts to evaluate, de novo, the repeat structure present within large eukaryotic genomes. This approach avoids sequence alignment and similarity search, two of the most time-consuming components of traditional methods for repeat identification. Algorithms were implemented to efficiently calculate exact counts for any length oligonucleotide in large genomes. Based on these oligonucleotide counts, oligonucleotide excess probability clouds, or "P-clouds," were constructed. P-clouds are composed of clusters of related oligonucleotides that occur, as a group, more often than expected by chance. After construction, P-clouds were mapped back onto the genome, and regions of high P-cloud density were identified as repetitive regions based on a sliding window approach. This efficient method is capable of analyzing the repeat content of the entire human genome on a single desktop computer in less than half a day, at least 10-fold faster than current approaches. The predicted repetitive regions strongly overlap with known repeat elements as well as other repetitive regions such as gene families, pseudogenes, and segmental duplicons. This method should be extremely useful as a tool for use in de novo identification of repeat structure in large newly sequenced genomes.

  9. MRI atlas of the brain

    SciTech Connect

    Bradley, W.G. ); Bydder, G. )

    1990-01-01

    Since most radiologists will start from a basic of familiarity with pathophysiology of disease and a knowledge of cross-sectional imaging (at least in the transaxial plane), they are in a good position to recognize and diagnose many of the abnormalities we can currently see with CT. The appearance of these lesions on MRI is the basis for the majority of the images in this book. Chapters on Tumors, Infarcts and Ischemia, Demyelination and Infection. Hydrocephalus, and Pediatrics feature multiple images displaying the MR appearance of many common lesions with minimal associated text. Instead of focusing on pathophysiology, attention is directed to the variable appearance of these disease states using various MR imaging techniques. Although the MR contrast agent, Gadolinium-DTPA, has similar behavior (physiologically) to meglumine diatrizoate in CT, the MR techniques which result in optimal visualization of enhancing lesions are nonintuitive and are discussed. Similarly, the appearance of flowing blood and CSF and hemorrhage does not follow easily from a pre-existing CT base, therefore additional text has been devoted to these subjects.

  10. Gradient-Modulated PETRA MRI

    PubMed Central

    Kobayashi, Naoharu; Goerke, Ute; Wang, Luning; Ellermann, Jutta; Metzger, Gregory J.; Garwood, Michael

    2015-01-01

    Image blurring due to off-resonance and fast T2* signal decay is a common issue in radial ultrashort echo time MRI sequences. One solution is to use a higher readout bandwidth, but this may be impractical for some techniques like pointwise encoding time reduction with radial acquisition (PETRA), which is a hybrid method of zero echo time and single point imaging techniques. Specifically, PETRA has severe specific absorption rate (SAR) and radiofrequency (RF) pulse peak power limitations when using higher bandwidths in human measurements. In this study, we introduce gradient modulation (GM) to PETRA to reduce image blurring artifacts while keeping SAR and RF peak power low. Tolerance of GM-PETRA to image blurring was evaluated in simulations and experiments by comparing with the conventional PETRA technique. We performed inner ear imaging of a healthy subject at 7T. GM-PETRA showed significantly less image blurring due to off-resonance and fast T2* signal decay compared to PETRA. In in vivo imaging, GM-PETRA nicely captured complex structures of the inner ear such as the cochlea and semicircular canals. Gradient modulation can improve the PETRA image quality and mitigate SAR and RF peak power limitations without special hardware modification in clinical scanners. PMID:26771005

  11. Cerebral perfusion alterations in epileptic patients during peri-ictal and post-ictal phase: PASL vs DSC-MRI.

    PubMed

    Pizzini, Francesca B; Farace, Paolo; Manganotti, Paolo; Zoccatelli, Giada; Bongiovanni, Luigi G; Golay, Xavier; Beltramello, Alberto; Osculati, Antonio; Bertini, Giuseppe; Fabene, Paolo F

    2013-07-01

    Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment. PMID:23623332

  12. Cerebral perfusion alterations in epileptic patients during peri-ictal and post-ictal phase: PASL vs DSC-MRI.

    PubMed

    Pizzini, Francesca B; Farace, Paolo; Manganotti, Paolo; Zoccatelli, Giada; Bongiovanni, Luigi G; Golay, Xavier; Beltramello, Alberto; Osculati, Antonio; Bertini, Giuseppe; Fabene, Paolo F

    2013-07-01

    Non-invasive pulsed arterial spin labeling (PASL) MRI is a method to study brain perfusion that does not require the administration of a contrast agent, which makes it a valuable diagnostic tool as it reduces cost and side effects. The purpose of the present study was to establish the viability of PASL as an alternative to dynamic susceptibility contrast (DSC-MRI) and other perfusion imaging methods in characterizing changes in perfusion patterns caused by seizures in epileptic patients. We evaluated 19 patients with PASL. Of these, the 9 affected by high-frequency seizures were observed during the peri-ictal period (within 5hours since the last seizure), while the 10 patients affected by low-frequency seizures were observed in the post-ictal period. For comparison, 17/19 patients were also evaluated with DSC-MRI and CBF/CBV. PASL imaging showed focal vascular changes, which allowed the classification of patients in three categories: 8 patients characterized by increased perfusion, 4 patients with normal perfusion and 7 patients with decreased perfusion. PASL perfusion imaging findings were comparable to those obtained by DSC-MRI. Since PASL is a) sensitive to vascular alterations induced by epileptic seizures, b) comparable to DSC-MRI for detecting perfusion asymmetries, c) potentially capable of detecting time-related perfusion changes, it can be recommended for repeated evaluations, to identify the epileptic focus, and in follow-up and/or therapy-response assessment.

  13. Repeated buckling of composite shear panels

    NASA Technical Reports Server (NTRS)

    Singer, Josef; Weller, Tanchum

    1990-01-01

    Failures in service of aerospace structures and research at the Technion Aircraft Structures Laboratory have revealed that repeatedly buckled stiffened shear panels might be susceptible to premature fatigue failures. Extensive experimental and analytical studies have been performed at Technion on repeated buckling, far in excess of initial buckling, for both metal and composite shear panels with focus on the influence of the surrounding structure. The core of the experimental investigation consisted of repeated buckling and postbuckling tests on Wagner beams in a three-point loading system under realistic test conditions. The effects of varying sizes of stiffeners, of the magnitude of initial buckling loads, of the panel aspect ratio and of the cyclic shearing force, V sub cyc, were studied. The cyclic to critical shear buckling ratios, (V sub cyc/V sub cr) were on the high side, as needed for efficient panel design, yet all within possible flight envelopes. The experiments were supplemented by analytical and numerical analyses. For the metal shear panels the test and numerical results were synthesized into prediction formulas, which relate the life of the metal shear panels to two cyclic load parameters. The composite shear panels studied were hybrid beams with graphite/epoxy webs bonded to aluminum alloy frames. The test results demonstrated that composite panels were less fatigue sensitive than comparable metal ones, and that repeated buckling, even when causing extensive damage, did not reduce the residual strength by more than 20 percent. All the composite panels sustained the specified fatigue life of 250,000 cycles. The effect of local unstiffened holes on the durability of repeatedly buckled shear panels was studied for one series of the metal panels. Tests on 2024 T3 aluminum panels with relatively small unstiffened holes in the center of the panels demonstrated premature fatigue failure, compared to panels without holes. Preliminary tests on two graphite

  14. Quantification of Head Motion in Children During Various fMRI Language Tasks

    PubMed Central

    Yuan, Weihong; Altaye, Mekibib; Ret, Jen; Schmithorst, Vincent; Byars, Anna W.; Plante, Elena; Holland, Scott K.

    2009-01-01

    Purpose Head motion during functional MRI scanning can lead to signal artifact, a problem often more severe with children. However, the documentation for the characteristics of head motion in children during various language functional tasks is very limited in the current literature. This report characterizes head motion in children during fMRI as a function of age, sex, and task. Methods Head motion during four different fMRI language tasks was investigated in a group of 323 healthy children between the age of 5 and 18 years. A repeated measures ANOVA analysis was used to study the impact of age, sex, task, and the interaction of these factors on the motion. Results Pediatric subjects demonstrated significantly different amounts of head motion during fMRI when different language tasks were used. Word-Picture Matching, the only task that involved visual engagement, suffered the least amount of motion, which was significantly less than in any of the other three tasks; the latter were not significantly different from each other. Further examination revealed that the main effect of language task on motion was significantly affected by age, sex, and their interaction. Conclusion Our results suggest that age, sex, and task are all associated with the degree of head motion in children during fMRI experiments. Investigators working with pediatric patients may increase their success by using task components associated with less motion (e.g., visual stimuli), or by using this large scale dataset to estimate the effects of sex and age on motion for planning purposes. PMID:18636549

  15. "MRI Stealth" robot for prostate interventions.

    PubMed

    Stoianovici, Dan; Song, Danny; Petrisor, Doru; Ursu, Daniel; Mazilu, Dumitru; Muntener, Michael; Mutener, Michael; Schar, Michael; Patriciu, Alexandru

    2007-01-01

    The paper reports an important achievement in MRI instrumentation, a pneumatic, fully actuated robot located within the scanner alongside the patient and operating under remote control based on the images. Previous MRI robots commonly used piezoelectric actuation limiting their compatibility. Pneumatics is an ideal choice for MRI compatibility because it is decoupled from electromagnetism, but pneumatic actuators were hardly controllable. This achievement was possible due to a recent technology breakthrough, the invention of a new type of pneumatic motor, PneuStep 1, designed for the robot reported here with uncompromised MRI compatibility, high-precision, and medical safety. MrBot is one of the "MRI stealth" robots today (the second is described in this issue by Zangos et al.). Both of these systems are also multi-imager compatible, being able to operate with the imager of choice or cross-imaging modalities. For MRI compatibility the robot is exclusively constructed of nonmagnetic and dielectric materials such as plastics, ceramics, crystals, rubbers and is electricity free. Light-based encoding is used for feedback, so that all electric components are distally located outside the imager's room. MRI robots are modern, digital medical instruments in line with advanced imaging equipment and methods. These allow for accessing patients within closed bore scanners and performing interventions under direct (in scanner) imaging feedback. MRI robots could allow e.g. to biopsy small lesions imaged with cutting edge cancer imaging methods, or precisely deploy localized therapy at cancer foci. Our robot is the first to show the feasibility of fully automated in-scanner interventions. It is customized for the prostate and operates transperineally for needle interventions. It can accommodate various needle drivers for different percutaneous procedures such as biopsy, thermal ablations, or brachytherapy. The first needle driver is customized for fully automated low

  16. "MRI Stealth" robot for prostate interventions.

    PubMed

    Stoianovici, Dan; Song, Danny; Petrisor, Doru; Ursu, Daniel; Mazilu, Dumitru; Muntener, Michael; Mutener, Michael; Schar, Michael; Patriciu, Alexandru

    2007-01-01

    The paper reports an important achievement in MRI instrumentation, a pneumatic, fully actuated robot located within the scanner alongside the patient and operating under remote control based on the images. Previous MRI robots commonly used piezoelectric actuation limiting their compatibility. Pneumatics is an ideal choice for MRI compatibility because it is decoupled from electromagnetism, but pneumatic actuators were hardly controllable. This achievement was possible due to a recent technology breakthrough, the invention of a new type of pneumatic motor, PneuStep 1, designed for the robot reported here with uncompromised MRI compatibility, high-precision, and medical safety. MrBot is one of the "MRI stealth" robots today (the second is described in this issue by Zangos et al.). Both of these systems are also multi-imager compatible, being able to operate with the imager of choice or cross-imaging modalities. For MRI compatibility the robot is exclusively constructed of nonmagnetic and dielectric materials such as plastics, ceramics, crystals, rubbers and is electricity free. Light-based encoding is used for feedback, so that all electric components are distally located outside the imager's room. MRI robots are modern, digital medical instruments in line with advanced imaging equipment and methods. These allow for accessing patients within closed bore scanners and performing interventions under direct (in scanner) imaging feedback. MRI robots could allow e.g. to biopsy small lesions imaged with cutting edge cancer imaging methods, or precisely deploy localized therapy at cancer foci. Our robot is the first to show the feasibility of fully automated in-scanner interventions. It is customized for the prostate and operates transperineally for needle interventions. It can accommodate various needle drivers for different percutaneous procedures such as biopsy, thermal ablations, or brachytherapy. The first needle driver is customized for fully automated low

  17. Outcomes after thrombus aspiration for ST elevation myocardial infarction: 1-year follow-up of the prospective randomised TOTAL trial

    PubMed Central

    Jolly, Sanjit S; Cairns, John A; Yusuf, Salim; Rokoss, Michael J; Gao, Peggy; Meeks, Brandi; Kedev, Sasko; Stankovic, Goran; Moreno, Raul; Gershlick, Anthony; Chowdhary, Saqib; Lavi, Shahar; Niemela, Kari; Bernat, Ivo; Cantor, Warren J; Cheema, Asim N; Steg, Philippe Gabriel; Welsh, Robert C; Sheth, Tej; Bertrand, Olivier F; Avezum, Alvaro; Bhindi, Ravinay; Natarajan, Madhu K; Horak, David; Leung, Raymond C M; Kassam, Saleem; Rao, Sunil V; El-Omar, Magdi; Mehta, Shamir R; Velianou, James L; Pancholy, Samir; Džavík, Vladimír

    2016-01-01

    Summary Background Two large trials have reported contradictory results at 1 year after thrombus aspiration in ST elevation myocardial infarction (STEMI). In a 1-year follow-up of the largest randomised trial of thrombus aspiration, we aimed to clarify the longer-term benefits, to help guide clinical practice. Methods The trial of routine aspiration ThrOmbecTomy with PCI versus PCI ALone in Patients with STEMI (TOTAL) was a prospective, randomised, investigator-initiated trial of routine manual thrombectomy versus percutaneous coronary intervention (PCI) alone in 10 732 patients with STEMI. Eligible adult patients (aged ≥18 years) from 87 hospitals in 20 countries were enrolled and randomly assigned (1:1) within 12 h of symptom onset to receive routine manual thrombectomy with PCI or PCI alone. Permuted block randomisation (with variable block size) was done by a 24 h computerised central system, and was stratified by centre. Participants and investigators were not masked to treatment assignment. The trial did not show a difference at 180 days in the primary outcome of cardiovascular death, myocardial infarction, cardiogenic shock, or heart failure. However, the results showed improvements in the surrogate outcomes of ST segment resolution and distal embolisation, but whether or not this finding would translate into a longer term benefit remained unclear. In this longer-term follow-up of the TOTAL study, we report the results on the primary outcome (cardiovascular death, myocardial infarction, cardiogenic shock, or heart failure) and secondary outcomes at 1 year. Analyses of the primary outcome were by modified intention to treat and only included patients who underwent index PCI. This trial is registered with ClinicalTrials.gov, number NCT01149044. Findings Between Aug 5, 2010, and July 25, 2014, 10 732 eligible patients were enrolled and randomly assigned to thrombectomy followed by PCI (n=5372) or to PCI alone (n=5360). After exclusions of patients who did not

  18. Risk of Recurrent Helicobacter pylori Infection 1 Year After Initial Eradication Therapy in 7 Latin American Communities

    PubMed Central

    Morgan, Douglas R.; Torres, Javier; Sexton, Rachael; Herrero, Rolando; Salazar-Martínez, Eduardo; Robert Greenberg, E.; Bravo, Luis Eduardo; Dominguez, Ricardo L.; Ferreccio, Catterina; Lazcano-Ponce, Eduardo C.; Meza-Montenegro, Maria Mercedes; Peña, Edgar M.; Peña, Rodolfo; Correa, Pelayo; Martínez, María Elena; Chey, William D.; Valdivieso, Manuel; Anderson, Garnet L.; Goodman, Gary E.; Crowley, John J.; Baker, Laurence H.

    2013-01-01

    Importance The long-term effectiveness of Helicobacter pylori eradication programs for preventing gastric cancer will depend on recurrence risk and individual and community factors. Objective To estimate risk of H pylori recurrence and assess factors associated with successful eradication 1 year after treatment. Design, Setting, and Participants Cohort analysis of 1463 randomized trial participants aged 21 to 65 years from 7 Latin American communities, who were treated for H pylori and observed between September 2009 and July 2011. Interventions Randomization to 1 of 3 treatment groups: 14-day lansoprazole, amoxicillin, and clarithromycin (triple therapy); 5-day lansoprazole and amoxicillin followed by 5-day lansoprazole, clarithromycin, and metronidazole (sequential); or 5-day lansoprazole, amoxicillin, clarithromycin, and metronidazole (concomitant). Participants with a positive (13) C-urea breath test (UBT) 6 to 8 weeks posttreatment were offered voluntary re-treatment with 14-day bismuth-based quadruple therapy. Measurements Recurrent infection after a negative posttreatment UBT and factors associated with successful eradication at 1-year follow-up. Results Among participants with UBT-negative results who had a 1-year follow-up UBT (n=1091), 125 tested UBT positive, a recurrence risk of 11.5% (95% CI, 9.6%–13.5%). Recurrence was significantly associated with study site (P=.03), nonadherence to initial therapy (adjusted odds ratio [AOR], 2.94; 95% CI, 1.31–6.13; P=.01), and children in the household (AOR, 1.17; 95% CI, 1.01–1.35 per child; P=.03). Of the 281 with positive posttreatment UBT results, 138 completed re-treatment, of whom 93 tested UBT negative at 1 year. Among the 1340 who had a 1-year UBT, 80.4% (95% CI, 76.4%–83.9%), 79.8% (95% CI, 75.8%–83.5%), and 77.8% (95% CI, 73.6%–81.6%) had UBT-negative results in the triple, sequential, and concomitant groups, respectively (P=.61), with 79.3% overall effectiveness (95% CI, 77.1%–81.5%). In a

  19. Accident and emergency attendances by children under the age of 1 year as a result of injury

    PubMed Central

    Macgregor, D

    2003-01-01

    Objectives: To examine all accident and emergency (A&E) department attendances by children under the age of 1 year over a period of 12 months. Also to try to identify the prevalence and severity of accident types in small children and to suggest ways to reduce such accidents. Methods: The A&E department of the Royal Aberdeen Children's Hospital (RACH) serves a population of over half a million. All children under 1 year of age attending this department in the year 2000 had their case notes reviewed by the author and the cause, type, and severity of the illness or injury noted. Results: During the 12 month audit period 1416 new cases under the age of 1 year presented to RACH, 790 of which presented directly to A&E. Six hundred and eighteen (78%) were self referred and 116 children attended A&E on more than one occasion during the year. Four hundred and thirty four (55%) of the A&E attendances were classed as "accidents", the remainder were mainly for medical conditions such as respiratory distress. Two hundred and sixty four (61%) were caused by falls and 38% were admitted for inpatient management. Two hundred and twenty nine (29%) required radiographs, which revealed 30 fractures. Thirty seven children sustained scalds/burns and there were 33 accidental ingestions. Six cases were judged to be non-accidental. Conclusions: There is a surprisingly high rate of "accidental" injury in this age group, bringing into question the effectiveness of current accident prevention strategies. Perhaps specific prevention advice should be targeted at parents and carers of young children. There should always be a high index of suspicion for non-accidental injury. PMID:12533361

  20. Individual, physical and psychological risk factors for neck pain in Australian office workers: a 1-year longitudinal study.

    PubMed

    Hush, Julia M; Michaleff, Zoe; Maher, Christopher G; Refshauge, Kathryn

    2009-10-01

    Neck pain is more prevalent in office workers than in the general community. To date, findings from prospective studies that investigated causal relationships between putative risk factors and the onset of neck pain in this population have been limited by high loss to follow-up. The aim of this research was to prospectively evaluate a range of risk factors for neck pain in office workers, using validated and reliable objective measures as well as attain an estimate of 1-year incidence. We assembled a cohort of 53 office workers without neck pain and measured individual, physical, workplace and psychological factors at baseline. We followed participants for 1 year to measure the incidence of neck pain. We achieved 100% participant follow-up. Cox regression analysis was applied to examine the relationship between the putative risk factors and the cumulative incidence of neck pain. The 1-year incidence proportion of neck pain in Australian office workers was estimated in this study to be 0.49 (95% CI 0.36-0.62). Predictors of neck pain with moderate to large effect sizes were female gender (HR: 3.07; 95% CI: 1.18-7.99) and high psychological stress (HR: 1.64; 95% CI: 0.66-4.07). Protective factors included increased mobility of the cervical spine (HR: 0.44; 95% CI: 0.19-1.05) and frequent exercise (HR: 0.64; 95% CI: 0.27-1.51). These results reveal that neck pain is common in Australian office workers and that there are risk factors that are potentially modifiable.

  1. BDNF and NGF Signalling in Early Phases of Psychosis: Relationship With Inflammation and Response to Antipsychotics After 1 Year

    PubMed Central

    Martinez-Cengotitabengoa, M.; MacDowell, K.S.; Alberich, S.; Diaz, F.J.; Garcia-Bueno, B.; Rodriguez-Jimenez, R.; Bioque, M.; Berrocoso, E.; Parellada, M.; Lobo, A.; Saiz, P.A.; Matute, C.; Bernardo, M.; Gonzalez-Pinto, A.; Leza, J.C.

    2016-01-01

    Previous studies have indicated systemic deregulation of the proinflammatory or anti-inflammatory balance in individuals with first-episode psychosis (FEP) that persists 12 months later. To identify potential risk/protective factors and associations with symptom severity, we assessed possible changes in plasma levels of neurotrophins (brain-derived neurotrophic factor [BDNF] and nerve growth factor [NGF]) and their receptors in peripheral blood mononuclear cells (PBMCs). Expression of the 2 forms of BDNF receptors (active TrkB-FL and inactiveTrkB-T1) in PBMCs of FEP patients changed over time, TrkB-FL expression increasing by 1 year after diagnosis, while TrkB-T1 expression decreased. The TrkB-FL/TrkB-T1 ratio (hereafter FL/T1 ratio) increased during follow-up in the nonaffective psychosis group only, suggesting different underlying pathophysiological mechanisms in subgroups of FEP patients. Further, the expression of the main NGF receptor, TrkA, generally increased in patients at follow-up. After adjusting for potential confounders, baseline levels of inducible isoforms of nitric oxide synthase, cyclooxygenase, and nuclear transcription factor were significantly associated with the FL/T1 ratio, suggesting that more inflammation is associated with higher values of this ratio. Interestingly, the FL/T1 ratio might have a role as a predictor of functioning, a regression model of functioning at 1 year suggesting that the effect of the FL/T1 ratio at baseline on functioning at 1 year depended on whether patients were treated with antipsychotics. These findings may have translational relevance; specifically, it might be useful to assess the expression of TrkB receptor isoforms before initiating antipsychotic treatment in FEPs. PMID:26130821

  2. Predictors of Shoulder Pain and Disability Index (SPADI) and work status after 1 year in patients with subacromial shoulder pain

    PubMed Central

    2010-01-01

    Background Shoulder pain is a common complaint in primary health care and has an unfavourable outcome in many patients. The objectives were to identify predictors for pain and disability (SPADI) and work status in patients with subacromial shoulder pain. Methods Secondary analyses of data from a randomized clinical controlled trial were performed. Outcome measures were the absolute values of the combined Shoulder Pain and Disability Index (SPADI) and work status 1 year after treatment with supervised exercises (SE) or radial extracorporeal shockwave therapy (rESWT). Predictors of outcome were investigated using multiple linear regression (SPADI) and logistic regression (work status). Results 104 patients were included. Low education (≤ 12 years), previous shoulder pain, and a high baseline SPADI score predicted poor results with these variables explaining 29.9% of the variance in SPADI score at 1 year. Low education and poor self-reported health status predicted a work status of "not working": Odds Ratio, OR = 4.3(95% CI (1.3 to 14.9)), p = 0.02 for education, and OR = 1.06 (95% CI (1.0 to 1.1)), p = 0.001 for self-reported health status, respectively. Adjustments for age, gender, and treatment group were performed, but did not change the results. Conclusion Education was the most consistent predictor of pain and disability, and work status at 1 year follow-up. Also, baseline SPADI score, previous shoulder pain and self-reported health status predicted outcome. Trial registration Clinical trials NCT00653081 PMID:20863369

  3. Visceral and not subcutaneous abdominal adiposity reduction drives the benefits of a 1-year lifestyle modification program.

    PubMed

    Borel, Anne-Laure; Nazare, Julie-Anne; Smith, Jessica; Alméras, Natalie; Tremblay, Angelo; Bergeron, Jean; Poirier, Paul; Després, Jean-Pierre

    2012-06-01

    Excess visceral adipose tissue (VAT) is associated with an increased cardiometabolic risk. The study examined whether changes in cardiometabolic risk markers after a 1-year lifestyle intervention in viscerally obese men were associated with changes in VAT or with changes in subcutaneous abdominal adipose tissue (SAT). The relative contributions of changes in global adiposity vs. changes in cardiorespiratory fitness to changes in VAT were also quantified. One hundred and forty four men were selected on the basis of an increased waist circumference (≥ 90 cm) associated with dyslipidemia (triglycerides ≥ 1.69 and/or high-density lipoprotein (HDL)-cholesterol <1.03 mmol/l); 117 men completed the 1-year intervention which consisted in a healthy eating, physical activity/exercise program. Body weight, body composition, and fat distribution were assessed by anthropometry and dual-energy X-ray absorptiometry (DEXA)/computed tomography. Cardiorespiratory fitness, plasma adipokine/inflammatory markers, fasting lipoprotein-lipid profile, and oral glucose tolerance test (OGTT) were assessed. VAT volume decreased by 26%, cardiorespiratory fitness improved by 20% (P < 0.0001) after 1 year. Plasma adipokine/inflammatory markers, lipids/lipoproteins, and glucose homeostasis were improved. One-year changes in triglyceride (r = 0.29), apolipoprotein B (r = 0.21), 120-min OGTT-glucose (r = 0.27), and fasting insulin (r = 0.27) levels correlated with changes in VAT (all P < 0.05) after adjustment for changes in SAT. Using a multilinear regression model, VAT reduction was independently associated with SAT reduction and with improvement in cardiorespiratory fitness (R(2) = 0.58, P < 0.0001). Therefore, this healthy eating-physical activity/exercise program improved the cardiometabolic risk profile of viscerally obese men in relation to the reduction of VAT. Furthermore, the reduction in VAT was independently related to the reduction in global adiposity and to the improvement in

  4. Impact of Different Childhood Adversities on 1-Year Outcomes of Psychotic Disorder in the Genetics and Psychosis Study

    PubMed Central

    Trotta, Antonella; Murray, Robin M.; David, Anthony S.; Kolliakou, Anna; O’Connor, Jennifer; Di Forti, Marta; Dazzan, Paola; Mondelli, Valeria; Morgan, Craig; Fisher, Helen L.

    2016-01-01

    While the role of childhood adversity in increasing the risk of psychosis has been extensively investigated, it is not clear what the impact of early adverse experiences is on the outcomes of psychotic disorders. Therefore, we investigated associations between childhood adversity and 1-year outcomes in 285 first-presentation psychosis patients. Exposure to childhood adversity prior to 17 years of age was assessed using the Childhood Experience of Care and Abuse Questionnaire. Data on illness course, symptom remission, length of psychiatric hospitalization, compliance with medication, employment, and relationship status were extracted from clinical records for the year following first contact with mental health services for psychosis. Seventy-one percent of patients reported exposure to at least 1 type of childhood adversity (physical abuse, sexual abuse, parental separation, parental death, disrupted family arrangements, or being taken into care). No robust associations were found between childhood adversity and illness course or remission. However, childhood physical abuse was associated with almost 3-fold increased odds of not being in a relationship at 1-year follow-up compared to patients who did not report such adverse experiences. There was also evidence of a significant association between parental separation in childhood and longer admissions to psychiatric wards during 1-year follow-up and 2-fold increased odds of noncompliance with medication compared to those not separated from their parents. Therefore, our findings suggest that there may be some specificity in the impact of childhood adversity on service use and social functioning among psychosis patients over the first year following presentation to mental health services. PMID:26373540

  5. Impact of Renal Sympathetic Denervation on Left Ventricular Structure and Function at 1-Year Follow-Up

    PubMed Central

    de Sousa Almeida, Manuel; de Araújo Gonçalves, Pedro; Branco, Patricia; Mesquita, João; Carvalho, Maria Salomé; Dores, Helder; Silva Sousa, Henrique; Gaspar, Augusta; Horta, Eduarda; Aleixo, Ana; Neuparth, Nuno; Mendes, Miguel; Andrade, Maria João

    2016-01-01

    Background Catheter-based sympathetic renal denervation (RDN) is a recent therapeutic option for patients with resistant hypertension. However, the impact of RDN in left ventricular (LV) mass and function is not completely established. Our aim was to evaluate the effects of RDN on LV structure and function (systolic and diastolic) in patients with resistant hypertension (HTN). Methods and Results From a single centre prospective registry including 65 consecutive patients with resistant HTN submitted to RDN between July-2011 and April-2015, 31 patients with baseline and 1-year follow-up echocardiogram were included in this analysis. Mean age was 65±7 years, 48% were males, 71% had type 2 diabetes. Most had hypertension lasting for more than 10 years (90%), and were being treated with a median number of 6 anti-hypertensive drugs, including 74% on spironolactone. At 1-year, there was a significant decrease both on office SBP (176±24 to 149±13mmHg, p<0.001) and DBP (90±14 to 79±11mmHg, p<0.001), and also in 24h ABPM SBP (150±20 to 132±14mmhg, p<0.001) and DBP (83±10 to 74±9mmHg, p<0.001). There was also a significant decrease in LV mass from 152±32 to 136±34g/m2 (p<0.001), an increase in LV end diastolic volume (93±18 to 111±27 mL, p = 0.004), an increase in LV ejection fraction (65±9 to 68±9%, p = 0.001) and mitral valve E deceleration time (225±49 to 247±51ms, p = 0.015) at 1-year follow up. There were no significant changes in left atrium volume index or in the distribution of patients among the different left ventricle geometric patterns and diastolic function subgroups. Conclusions In this single centre registry of patients with resistant hypertension, renal denervation was associated with significant reduction in both office and ABPM blood pressure and a significant decrease in left ventricle mass evaluated by transthoracic echocardiogram at 1 year follow-up. PMID:26934735

  6. Sodium MRI in human heart: a review.

    PubMed

    Bottomley, Paul A

    2016-02-01

    This paper offers a critical review of the properties, methods and potential clinical application of sodium ((23)Na) MRI in human heart. Because the tissue sodium concentration (TSC) in heart is about ~40 µmol/g wet weight, and the (23)Na gyromagnetic ratio and sensitivity are respectively about one-quarter and one-11th of that of hydrogen ((1)H), the signal-to-noise ratio of (23)Na MRI in the heart is about one-6000th of that of conventional cardiac (1)H MRI. In addition, as a quadrupolar nucleus, (23)Na exhibits ultra-short and multi-component relaxation behavior (T1 ~ 30 ms; T2 ~ 0.5-4 ms and 12-20 ms), which requires fast, specialized, ultra-short echo-time MRI sequences, especially for quantifying TSC. Cardiac (23)Na MRI studies from 1.5 to 7 T measure a volume-weighted sum of intra- and extra-cellular components present at cytosolic concentrations of 10-15 mM and 135-150 mM in healthy tissue, respectively, at a spatial resolution of about 0.1-1 ml in 10 min or so. Currently, intra- and extra-cellular sodium cannot be unambiguously resolved without the use of potentially toxic shift reagents. Nevertheless, increases in TSC attributable to an influx of intra-cellular sodium and/or increased extra-cellular volume have been demonstrated in human myocardial infarction consistent with prior animal studies, and arguably might also be seen in future studies of ischemia and cardiomyopathies--especially those involving defects in sodium transport. While technical implementation remains a hurdle, a central question for clinical use is whether cardiac (23)Na MRI can deliver useful information unobtainable by other more convenient methods, including (1)H MRI.

  7. Multichannel compressive sensing MRI using noiselet encoding.

    PubMed

    Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

    2015-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding. PMID:25965548

  8. Multichannel compressive sensing MRI using noiselet encoding.

    PubMed

    Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

    2015-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding.

  9. Multichannel Compressive Sensing MRI Using Noiselet Encoding

    PubMed Central

    Pawar, Kamlesh; Egan, Gary; Zhang, Jingxin

    2015-01-01

    The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP) of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS). In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS) framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding. PMID:25965548

  10. COMPARISON OF THE COMPLETE FOURIER DIRECT MRI WITH EXISTING DIFFUSION WEIGHTED MRI METHODS

    PubMed Central

    Özcan, Alpay

    2011-01-01

    The Complete Fourier Direct (CFD) MRI method introduced in earlier work for modeling the diffusion weighted MRI signal is compared with the existing methods. The preservation of Hermitian symmetry in the diffusion weighted MRI signal without affecting its energy is the key point that differentiates CFD–MRI from the existing methods. By keeping the correct Fourier relationship intact, the joint distribution function is represented ‘as it is’, without any constraints, e.g. being symmetric. The necessity to model or assume models for spin motion and try to fit the model to the samples of the Fourier transform as in case of model matching methods is not required because the Discrete Fourier Transform applied to correctly processed signal in CFD–MRI gives more accurate results. PMID:21918715

  11. Multi-Institutional Review of Repeat Irradiation of Chest Wall and Breast for Recurrent Breast Cancer

    SciTech Connect

    Wahl, Andrew O.; Rademaker, Alfred; Kiel, Krystyna D.; Jones, Ellen L.; Marks, Lawrence B.; Croog, Victoria; McCormick, Beryl M.; Hirsch, Arica; Karkar, Ami; Motwani, Sabin B.; Tereffe, Welela; Yu, T.-K.; Sher, David; Silverstein, Joshua; Kachnic, Lisa A.; Kesslering, Christy; Freedman, Gary M.; Small, William

    2008-02-01

    Purpose: To review the toxicity and clinical outcomes for patients who underwent repeat chest wall or breast irradiation (RT) after local recurrence. Methods and Materials: Between 1993 and 2005, 81 patients underwent repeat RT of the breast or chest wall for locally recurrent breast cancer at eight institutions. The median dose of the first course of RT was 60 Gy and was 48 Gy for the second course. The median total radiation dose was 106 Gy (range, 74.4-137.5 Gy). At the second RT course, 20% received twice-daily RT, 54% were treated with concurrent hyperthermia, and 54% received concurrent chemotherapy. Results: The median follow-up from the second RT course was 12 months (range, 1-144 months). Four patients developed late Grade 3 or 4 toxicity. However, 25 patients had follow-up >20 months, and no late Grade 3 or 4 toxicities were noted. No treatment-related deaths occurred. The development of Grade 3 or 4 late toxicity was not associated with any repeat RT variables. The overall complete response rate was 57%. No repeat RT parameters were associated with an improved complete response rate, although a trend was noted for an improved complete response with the addition of hyperthermia that was close to reaching statistical significance (67% vs. 39%, p = 0.08). The 1-year local disease-free survival rate for patients with gross disease was 53% compared with 100% for those without gross disease (p < 0.0001). Conclusions: The results of our study have shown that repeat RT of the chest wall for patients with locally recurrent breast cancer is feasible, because it is associated with acceptable acute and late morbidity and encouraging local response rates.

  12. Repeatability of a running heat tolerance test.

    PubMed

    Mee, Jessica A; Doust, Jo; Maxwell, Neil S

    2015-01-01

    At present there is no standardised heat tolerance test (HTT) procedure adopting a running mode of exercise. Current HTTs may misdiagnose a runner's susceptibility to a hyperthermic state due to differences in exercise intensity. The current study aimed to establish the repeatability of a practical running test to evaluate individual's ability to tolerate exercise heat stress. Sixteen (8M, 8F) participants performed the running HTT (RHTT) (30 min, 9 km h(-1), 2% elevation) on two separate occasions in a hot environment (40 °C and 40% relative humidity). There were no differences in peak rectal temperature (RHTT1: 38.82 ± 0.47 °C, RHTT2: 38.86 ± 0.49 °C, Intra-class correlation coefficient (ICC)=0.93, typical error of measure (TEM) = 0.13 °C), peak skin temperature (RHTT1: 38.12 ± 0.45, RHTT2: 38.11 ± 0.45 °C, ICC = 0.79, TEM = 0.30 °C), peak heart rate (RHTT1: 182 ± 15 beats min(-1), RHTT2: 183 ± 15 beats min(-1), ICC = 0.99, TEM = 2 beats min(-1)), nor sweat rate (1721 ± 675 g h(-1), 1716 ± 745 g h(-1), ICC = 0.95, TEM = 162 g h(-1)) between RHTT1 and RHTT2 (p>0.05). Results demonstrate good agreement, strong correlations and small differences between repeated trials, and the TEM values suggest low within-participant variability. The RHTT was effective in differentiating between individuals physiological responses; supporting a heat tolerance continuum. The findings suggest the RHTT is a repeatable measure of physiological strain in the heat and may be used to assess the effectiveness of acute and chronic heat alleviating procedures. PMID:25774031

  13. Repeated vitrification/warming of human sperm gives better results than repeated slow programmable freezing

    PubMed Central

    Vutyavanich, Teraporn; Lattiwongsakorn, Worashorn; Piromlertamorn, Waraporn; Samchimchom, Sudarat

    2012-01-01

    In this study, we compared the effects of repeated freezing/thawing of human sperm by our in-house method of rapid freezing with slow programmable freezing. Sperm samples from 11 normozoospermic subjects were processed through density gradients and divided into three aliquots: non-frozen, rapid freezing and slow programmable freezing. Sperm in the rapid freezing group had better motility and viability than those in the slow freezing group (P<0.01) after the first, second and third cycles of freezing/thawing, but there was no difference in morphology. In the second experiment, rapid freezing was repeated three times in 20 subjects. The samples from each thawing cycle were evaluated for DNA fragmentation using the alkaline comet assay. DNA fragmentation began to increase considerably after the second cycle of freezing/thawing, but to a level that was not clinically important. In the third experiment, rapid freezing was done repeatedly in 10 subjects, until no motile sperm were observed after thawing. The median number of repeated freezing/thawing that yielded no motile sperm was seven (range: 5–8, mean: 6.8). In conclusion, we demonstrated that repeated freezing/thawing of processed semen using our rapid freezing method gave better results than standard slow programmable freezing. This method can help maximize the usage of precious cryopreserved sperm samples in assisted reproduction technology. PMID:23064685

  14. Capping motifs stabilize the leucine-rich repeat protein PP32 and rigidify adjacent repeats.

    PubMed

    Dao, Thuy P; Majumdar, Ananya; Barrick, Doug

    2014-06-01

    Capping motifs are found to flank most β-strand-containing repeat proteins. To better understand the roles of these capping motifs in organizing structure and stability, we carried out folding and solution NMR studies on the leucine-rich repeat (LRR) domain of PP32, which is composed of five tandem LRR, capped by α-helical and β-hairpin motifs on the N- and C-termini. We were able to purify PP32 constructs lacking either cap and containing destabilizing substitutions. Removing the C-cap results in complete unfolding of PP32. Removing the N-cap has a much less severe effect, decreasing stability but retaining much of its secondary structure. In contrast, the dynamics and tertiary structure of the first two repeats are significantly perturbed, based on (1)H-(15)N relaxation studies, chemical shift perturbations, and residual dipolar couplings. However, more distal repeats (3 to C-cap) retain their native tertiary structure. In this regard, the N-cap drives the folding of adjacent repeats from what appears to be a molten-globule-like state. This interpretation is supported by extensive analysis using core packing substitutions in the full-length and N-cap-truncated PP32. This work highlights the importance of caps to the stability and structural integrity of β-strand-containing LRR proteins, and emphasizes the different contributions of the N- and C-terminal caps. PMID:24659532

  15. Distillation by repeated measurements: Continuous spectrum case

    SciTech Connect

    Bellomo, Bruno; Compagno, Giuseppe; Nakazato, Hiromichi; Yuasa, Kazuya

    2010-12-15

    Repeated measurements on one part of a bipartite system strongly affect the other part that is not measured, the dynamics of which is regulated by an effective contracted evolution operator. When the spectrum of this operator is discrete, the nonmeasured system is driven into a pure state, irrespective of the initial state, provided that the spectrum satisfies certain conditions. We show here that, even in the case of continuous spectrum, an effective distillation can occur under rather general conditions. We confirm it by applying our formalism to a simple model.

  16. Innovative collaboration to prevent repeated adolescent pregnancies.

    PubMed

    Saunders, R B; Brown, H N

    1997-01-01

    Nurse educators from a university setting and staff from the county health department collaborated to establish an innovative program to prevent repeated pregnancy in adolescents. Called Dollar-A-Day and patterned after the original in Denver, CO, the program was operated jointly for 5 years and today continues to operate under the auspices of the health department. Success of the venture is attributed to use of skills in assessment, building, managing, and evaluating, as described by Loxley (1997). These elements were used to construct a context for collaboration.

  17. Multifunctional protein: cardiac ankyrin repeat protein*

    PubMed Central

    Zhang, Na; Xie, Xiao-jie; Wang, Jian-an

    2016-01-01

    Cardiac ankyrin repeat protein (CARP) not only serves as an important component of muscle sarcomere in the cytoplasm, but also acts as a transcription co-factor in the nucleus. Previous studies have demonstrated that CARP is up-regulated in some cardiovascular disorders and muscle diseases; however, its role in these diseases remains controversial now. In this review, we will discuss the continued progress in the research related to CARP, including its discovery, structure, and the role it plays in cardiac development and heart diseases. PMID:27143260

  18. Yet another model of soft gamma repeaters

    NASA Technical Reports Server (NTRS)

    Katz, J. I.; Toole, H. A.; Unruh, S. H.

    1994-01-01

    We develop a model of soft gamma repeaters (SGRs) in which a supernova leaves planets orbiting a neutron star in intersecting orbits. These planets will collide in approximately 10(exp 4) yr if their orbits are coplanar. Some fragments of debris lose their angular momentum in the collision and fall onto the neutron star, producing a SGR. The initial accretion of matter left by the collision with essntially no angular momentum may produce a superburst like that of 1979 March 5, while debris fragments which later lose their angular momentum produce an irregular but non-Poissonian pattern of smaller bursts resembling those observed in spectrum and duration.

  19. Synthesis of biotinylated keratan sulfate repeating disaccharides.

    PubMed

    Takeda, Naoko; Tamura, Jun-Ichi

    2014-01-01

    We synthesized four types of keratan and keratan sulfate repeating disaccharides containing non-sulfate, Galβ1-4GlcNAcβ, and three types of sulfates, Gal6Sβ1-4GlcNAcβ, Galβ1-4GlcNAc6Sβ, and Gal6Sβ1-4GlcNAc6Sβ in an efficient and stereo-controlled manner. These disaccharides were conjugated with biotin via a hydrophilic linker at the reducing terminal.

  20. Platelet peripheral benzodiazepine receptors in repeated stress

    SciTech Connect

    Dar, D.E.; Bidder, M.; Gavish, M. ); Weizman, A.; Karp, L.; Tyano, S. ); Grinshpoon, A.; Bleich, A.

    1991-01-01

    ({sup 3}H)PK 11195 binding to platelet membranes and plasma stress hormones were studied in soldiers at the beginning of a parachute training course, following 6 days of preparatory exercises, and after the fourth actual parachute jump. A slight reduction (15%; NS) in the number of peripheral benzodiazepine receptors (PBR) was detected at the end of the exercise period, prior to the first jump. Reduced density of PBR was observed immediately after the repeated actual jumps. Equilibrium dissociation constants were not affected by the stressful situation. Plasma cortisol and prolactin levels remained unaltered during the entire study period.

  1. On the nature of soft gamma repeaters

    NASA Technical Reports Server (NTRS)

    Norris, J. P.; Hertz, P.; Wood, K. S.; Kouveliotou, C.

    1991-01-01

    The nature of soft gamma repeaters (SGRs) is discussed on the basis of data available for the March 5, 1979 superburst described by Cline et al. (1982) and for the less intense bursts detected by instruments on board Venera 11/12 and 13/14. It is argued that the three known SGR bursters can be explained most economically and consistently as belonging to a single class, with source distances of tens of kiloparsecs. The viability of several proposed models developed for the SGR energy release mechanism is examined.

  2. Different multivariate techniques for automated classification of MRI data in Alzheimer's disease and mild cognitive impairment.

    PubMed

    Aguilar, Carlos; Westman, Eric; Muehlboeck, J-Sebastian; Mecocci, Patrizia; Vellas, Bruno; Tsolaki, Magda; Kloszewska, Iwona; Soininen, Hilkka; Lovestone, Simon; Spenger, Christian; Simmons, Andrew; Wahlund, Lars-Olof

    2013-05-30

    Automated structural magnetic resonance imaging (MRI) processing pipelines and different multivariate techniques are gaining popularity for Alzheimer's disease (AD) research. We used four supervised learning methods to classify AD patients and controls (CTL) and to prospectively predict the conversion of mild cognitive impairment (MCI) to AD from baseline MRI data. A total of 345 participants from the AddNeuroMed cohort were included in this study; 116 AD patients, 119 MCI patients and 110 CTL individuals. High resolution sagittal 3D MP-RAGE datasets were acquired and MRI data were processed using FreeSurfer. We explored the classification ability of orthogonal projections to latent structures (OPLS), decision trees (Trees), artificial neural networks (ANN) and support vector machines (SVM). Applying 10-fold cross-validation demonstrated that SVM and OPLS were slightly superior to Trees and ANN, although not statistically significant for distinguishing between AD and CTL. The classification experiments resulted in up to 83% sensitivity and 87% specificity for the best techniques. For the prediction of conversion of MCI patients at baseline to AD at 1-year follow-up, we obtained an accuracy of up to 86%. The value of the multivariate models derived from the classification of AD vs. CTL was shown to be robust and efficient in the identification of MCI converters.

  3. The Use of MRI Modeling to Enhance Osteochondral Transfer in Segmental Kienböck's Disease.

    PubMed

    Barber, Lauren; Koff, Matthew F; Virtue, Patrick; Lipman, Joseph P; Hotchkiss, Robert J; Potter, Hollis G

    2012-04-01

    Kienböck's disease, defined as avascular necrosis of the lunate, is a relatively rare condition with a poorly understood etiology. Conservative and invasive treatments for Kienböck's disease exist, including wrist immobilization, surgical joint-leveling procedures, vascularized bone grafting, proximal row carpectomy, and total wrist arthrodesis. Staging Kienböck's disease using radiography assumes near complete avascularity of the lunate. The staging distinguishes only the "state of collapse" in an ordinal classification scheme and does not allow localization or indicate partial involvement of the lunate, which the image contrast from MRI may provide. In this short communication, we report the treatment of a patient's Kienböck's disease by combining MRI with mathematical modeling to optimize the congruency between the curvature of donor and recipient sites of an autologous osteoarticular plug transfer. Follow-up MRI and radiographs at 1 year postoperatively demonstrated gradual graft incorporation and bone healing. The purpose of this study was to describe the feasibility of a novel surgical technique. The results indicate that donor site selection for autologous osteoarticular transfer using a quantitative evaluation of articular surface curvature may be beneficial for optimizing the likelihood for restoring the radius of curvature and thus joint articulation following cartilage repair.

  4. The immediate effect of repeated loading on the compressive strength of young porcine lumbar spine.

    PubMed

    Thoreson, Olof; Baranto, Adad; Ekström, Lars; Holm, Sten; Hellström, Mikael; Swärd, Leif

    2010-05-01

    The human spine is exposed to repeated loading during daily activities and more extremely during sports. Despite this, there remains a lack of knowledge regarding the immediate effects on the spine due to this mode of loading. Age-specific spinal injury patterns has been demonstrated and this implies differences in reaction to load mode and load history The purpose of the present study was to investigate the impact of cyclic pre-loading on the biomechanical properties and fracture patterns of the adolescent spine in an experimental model. Eight functional spinal units from four young porcine spines were harvested. The functional spinal units were cyclic loaded with 20,000 cycles and then axially compressed to failure. The compression load at failure, ultimate stress and viscoelastic parameters were calculated. The functional spinal units were examined with plain radiography, computer tomography and MRI before and after the loading, and finally macroscopically and histologically. The median compression load at failure in this study was 8.3 kN (range 5.6-8.7 kN). The median deformation for all cases was 2.24 mm (range 2.30-2.7 mm) and stiffness was 3.45 N/mm (range 3.5-4.5 N/mm). A fracture was seen on radiograph in one case, on CT and macroscopically in seven, and on MRI and histologically in all eight cases. The cyclic loaded functional spinal units in the present study were not more sensitive to axial compression than non-cyclic loaded functional spinal units from young porcine. The endplate and the growth zone were the weakest part in the cyclic loaded functional spinal units. Disc signal reduction and disc height reduction was found on MRI. The E-modulus value found in this study was of the same order of magnitude as found by others using a porcine animal model.

  5. Management and 1-year outcomes of patients with atrial fibrillation in the Middle East: Gulf survey of atrial fibrillation events.

    PubMed

    Zubaid, Mohammad; Rashed, Wafa A; Alsheikh-Ali, Alawi A; Al-Zakwani, Ibrahim; AlMahmeed, Wael; Shehab, Abdullah; Sulaiman, Kadhim; Qudaimi, Ahmed Al; Asaad, Nidal; Amin, Haitham

    2015-05-01

    We describe management and outcomes of patients with nonvalvular atrial fibrillation (AF) in the Middle East. Consecutive patients with AF presenting to emergency departments (EDs) were prospectively enrolled. Among 1721 patients with nonvalvular AF, mean age was 59 ± 16 years and 44% were women. Comorbidities were common such as hypertension (59%), diabetes (33%), and coronary artery disease (33%). Warfarin was not prescribed to 40% of patients with Congestive heart failure, Hypertension, Age, Diabetes mellitus, Stroke/TIA2 score of ≥2. One-year rates of stroke/transient ischemic attack (TIA) and all-cause mortality were 4.2% and 15.3%, respectively. Warfarin use at hospital-ED discharge was independently associated with lower 1-year rate of stroke/TIA (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.17-0.85; P = .015) and all-cause mortality (OR, 0.51; 95% CI, 0.32-0.83; P = .006). Prior history of heart failure and peripheral vascular disease was independent mortality predictors. Our patients are relatively young with significant cardiovascular risk. Their anticoagulation treatment is suboptimal, and 1-year all-cause mortality and stroke/TIA event rates are relatively high.

  6. Cognitive function, social functioning and quality of life in first-episode psychosis: A 1-year longitudinal study.

    PubMed

    Popolo, Raffaele; Vinci, Giancarlo; Balbi, Andrea

    2010-03-01

    Abstract Objective. The majority of patients with schizophrenia have cognitive deficits early in the disease. We evaluated the relationship between cognitive function, social functioning and quality of life in patients with first-episode psychosis. Methods. This was a longitudinal study in 15 patients aged 18-30 years who had recently experienced a first psychotic episode and were treated with the atypical antipsychotic aripiprazole, cognitive-behavioural therapy, psycho-educational sessions, family supportive sessions and social interventions. Patients were evaluated at baseline and after 1 year. Cognitive assessment included attention, memory, language skills and problem solving. Social functioning, quality of life, and psychopathological evaluation were performed with validated tools. Results. At baseline, patients had a severe impairment of social functioning and a low quality of life, while a specific pattern of cognitive functions was not identified. After 1-year, we observed a significant improvement in social functioning and quality of life, without a significant decrease in cognitive function. Conclusion. Contrary to previous findings, we found that social functioning and quality of life are related, but independent of cognitive impairment. The use of antipsychotic agents that do not interefere with cognitive function plus psychological assistance is a valuable treatment approach in patients with first-episode schizophrenia.

  7. First experiences with the direct anterior approach in lateral decubitus position: learning curve and 1 year complication rate.

    PubMed

    Melman, Wietse P R; Mollen, Bas P; Kollen, Boudewijn J; Verheyen, Cees C P M

    2015-01-01

    The direct anterior approach (DAA) in supine position for hip arthroplasty has been reported to suffer from high complication rates initially. The DAA with the patient in lateral decubitus position is believed to provide better visibility and especially femoral accessibility with potential fewer complications.The first cohort of total hip prostheses, which were implanted by a single surgeon using DAA in lateral decubitus position more than 1 year ago, was analysed retrospectively.In total 182 hip prostheses (172 patients) were analysed. Three consecutive time periods based on equal number of surgical procedures were compared. The technical complication rate and operating time improved significantly between the 3 consecutive groups. The 1 year infection rate was 0.5% and survival rate of 98.9%.This is the first series of patients that were subjected to a hip replacement based on the direct anterior approach in a lateral decubitus position in which decreasing complication rates suggest the presence of a learning curve in surgeons conducting this type of surgery. Initial complication rate was high but decreased significantly in time and was acceptable certainly in the third group of our cohort. An unacceptable complication rate with the straight uncemented stem forced us to discontinue this configuration after only 7 surgical procedures. Complication, infection and revision rates were acceptable for the all cemented hip replacements using a curved anatomical stem. PMID:25684251

  8. Management and 1-year outcomes of patients with atrial fibrillation in the Middle East: Gulf survey of atrial fibrillation events.

    PubMed

    Zubaid, Mohammad; Rashed, Wafa A; Alsheikh-Ali, Alawi A; Al-Zakwani, Ibrahim; AlMahmeed, Wael; Shehab, Abdullah; Sulaiman, Kadhim; Qudaimi, Ahmed Al; Asaad, Nidal; Amin, Haitham

    2015-05-01

    We describe management and outcomes of patients with nonvalvular atrial fibrillation (AF) in the Middle East. Consecutive patients with AF presenting to emergency departments (EDs) were prospectively enrolled. Among 1721 patients with nonvalvular AF, mean age was 59 ± 16 years and 44% were women. Comorbidities were common such as hypertension (59%), diabetes (33%), and coronary artery disease (33%). Warfarin was not prescribed to 40% of patients with Congestive heart failure, Hypertension, Age, Diabetes mellitus, Stroke/TIA2 score of ≥2. One-year rates of stroke/transient ischemic attack (TIA) and all-cause mortality were 4.2% and 15.3%, respectively. Warfarin use at hospital-ED discharge was independently associated with lower 1-year rate of stroke/TIA (odds ratio [OR], 0.38; 95% confidence interval [CI], 0.17-0.85; P = .015) and all-cause mortality (OR, 0.51; 95% CI, 0.32-0.83; P = .006). Prior history of heart failure and peripheral vascular disease was independent mortality predictors. Our patients are relatively young with significant cardiovascular risk. Their anticoagulation treatment is suboptimal, and 1-year all-cause mortality and stroke/TIA event rates are relatively high. PMID:24904179

  9. Consecutive Case Series of Healed Single-Molar Sites Immediately Restored with Wide-Diameter Implants: A 1-Year Evaluation.

    PubMed

    Antoun, Hadi; Cherfane, Pierre; Sojod, Bouchra

    2016-01-01

    Introduction. To evaluate outcomes of wide-diameter (6 mm) implants immediately provisionalized with cement-retained single crowns in posterior molar sites. Materials and Methods. Forty-eight consecutive patients received a total of 53 moderately rough-surface, 6 mm diameter implants in healed sites. All implants were immediately provisionalized with a cement-retained provisional crown. Final prosthesis with cement-retained porcelain fused to metal crowns was delivered 3-6 months later. Patients were followed up for 1 year. Outcome measures were implant failures and success rate, complications, marginal bone levels, bone level changes, papilla index, bleeding on probing, and inflammation. Results. One patient was lost to follow-up. At one year, the implant survival and success rate were 98.1%. The mean marginal bone loss after 1 year was -0.17 ± 1.84 mm. Ideal papilla score was recorded at 83.8% of the sites. More than 95.6% of the sites showed no bleeding or inflammation. No procedure-related or device-related adverse events were reported. Conclusion. Wide-diameter (6 mm) implants can safely and successfully replace single posterior molars. Longer follow-up studies are necessary to evaluate the long-term success of these implants. PMID:27195008

  10. Consecutive Case Series of Healed Single-Molar Sites Immediately Restored with Wide-Diameter Implants: A 1-Year Evaluation

    PubMed Central

    Cherfane, Pierre; Sojod, Bouchra

    2016-01-01

    Introduction. To evaluate outcomes of wide-diameter (6 mm) implants immediately provisionalized with cement-retained single crowns in posterior molar sites. Materials and Methods. Forty-eight consecutive patients received a total of 53 moderately rough-surface, 6 mm diameter implants in healed sites. All implants were immediately provisionalized with a cement-retained provisional crown. Final prosthesis with cement-retained porcelain fused to metal crowns was delivered 3–6 months later. Patients were followed up for 1 year. Outcome measures were implant failures and success rate, complications, marginal bone levels, bone level changes, papilla index, bleeding on probing, and inflammation. Results. One patient was lost to follow-up. At one year, the implant survival and success rate were 98.1%. The mean marginal bone loss after 1 year was −0.17 ± 1.84 mm. Ideal papilla score was recorded at 83.8% of the sites. More than 95.6% of the sites showed no bleeding or inflammation. No procedure-related or device-related adverse events were reported. Conclusion. Wide-diameter (6 mm) implants can safely and successfully replace single posterior molars. Longer follow-up studies are necessary to evaluate the long-term success of these implants. PMID:27195008

  11. Self-management of chronic pain in Malaysian patients: effectiveness trial with 1-year follow-up.

    PubMed

    Cardosa, Mary; Osman, Zubaidah Jamil; Nicholas, Michael; Tonkin, Lois; Williams, Amanda; Abd Aziz, Khuzaimah; Mohd Ali, Ramli; Dahari, Norhana Mohd

    2012-03-01

    Self-management of chronic illnesses has been widely recognised as an important goal on quality of life, health service utilisation and cost grounds. This study describes the first published account on the application of this approach to people suffering from chronic pain conditions in a Southeast Asian country, Malaysia. A heterogeneous sample of chronic pain patients in Malaysia attended a 2-week cognitive-behavioural pain management programme (PMP) aimed at improving daily functional activities and general psychological well-being. Complete datasets from 70 patients out of 102 patients who attended 11 programmes conducted from 2002 to 2007, as well as the 1-month and 1-year follow-up sessions at the hospital clinic, are reported. The pre- to post-treatment results on self-report measures indicate that significant gains were achieved on the dimensions of pain, disability and psychological well-being. These gains were maintained at both 1-month and 1-year follow-ups. The results mirror those reported from similar interventions in Europe and North America and indicate the concept of self-management of a chronic illness is acceptable and meaningful to Asian patients. Importantly, the achieved outcomes were independent of gender and ethnic group status.

  12. Residential treatment for homeless female veterans with psychiatric and substance use disorders: effect on 1-year clinical outcomes.

    PubMed

    Harpaz-Rotem, Ilan; Rosenheck, Robert A; Desai, Rani

    2011-01-01

    Limited evidence shows that time-limited residential treatment (RT) is beneficial for homeless people with serious mental illness. The Department of Veterans Affairs has established 11 specialty programs for homeless female veterans. We present data comparing 1-year clinical outcomes in a group of veterans who did and did not receive at least 30 days of RT. Clients of the Homeless Women Veterans Programs were invited to participate in a follow-up study. They were interviewed every 3 months for 1 year. Those who received at least 30 days of RT in the 3 months after program entry (RT group) were compared with other program participants (no or <30 days RT [NRT] group) on measures of community functioning, psychiatric symptoms, and drug and alcohol use during the follow-up. The RT group had better outcomes on employment, social support, housing status, and psychiatric symptoms. They also had significantly increased use of drugs and alcohol compared with the NRT group. Data suggest that RT may have a beneficial effect on mental health outcomes in homeless women. This study, in conjunction with others, suggests that provision of stable housing may be an important element of recovery for homeless women with psychiatric problems, excluding substance use.

  13. Acupuncture and occlusal splint therapy in the treatment of craniomandibular disorders. II. A 1-year follow-up study.

    PubMed

    List, T; Helkimo, M

    1992-12-01

    Eighty patients, of whom 22 were men and 58 women, participated in a 1-year follow-up study. All participants in the study showed signs and symptoms of craniomandibular disorders (CMD) and had had pain for more than 6 months at treatment start. The patients were randomly assigned to either acupuncture or occlusal splint therapy. Those patients who did not respond to either of the treatment modes were offered various additional therapies. The result showed that 57% of the patients who received acupuncture and 68% of the patients treated with occlusal splint therapy benefited subjectively (p < 0.01) and clinically (p < 0.001) from the treatment over a 12-month period. No statistically significant difference was found between the two groups as to the assessment variables. Those patients who received various additional therapies after acupuncture and/or occlusal splint therapy responded favorably to additional treatment in only a few instances. The study showed that acupuncture gave positive results similar to those of occlusal splint therapy in patients with primarily myogenic CMD symptoms over a 1-year follow-up period.

  14. Low Field Squid MRI Devices, Components and Methods

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Hahn, Inseob (Inventor)

    2014-01-01

    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

  15. Low field SQUID MRI devices, components and methods

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I. (Inventor); Eom, Byeong H (Inventor); Hahn, Inseob (Inventor)

    2010-01-01

    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

  16. Low Field Squid MRI Devices, Components and Methods

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Hahn, Inseob (Inventor)

    2013-01-01

    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

  17. Low field SQUID MRI devices, components and methods

    NASA Technical Reports Server (NTRS)

    Penanen, Konstantin I. (Inventor); Eom, Byeong H. (Inventor); Hahn, Inseob (Inventor)

    2011-01-01

    Low field SQUID MRI devices, components and methods are disclosed. They include a portable low field (SQUID)-based MRI instrument and a portable low field SQUID-based MRI system to be operated under a bed where a subject is adapted to be located. Also disclosed is a method of distributing wires on an image encoding coil system adapted to be used with an NMR or MRI device for analyzing a sample or subject and a second order superconducting gradiometer adapted to be used with a low field SQUID-based MRI device as a sensing component for an MRI signal related to a subject or sample.

  18. Safety of implanted cardiac devices in an MRI environment.

    PubMed

    Ipek, Esra Gucuk; Nazarian, Saman

    2015-07-01

    Magnetic resonance imaging (MRI) has evolved into an essential diagnostic modality for the evaluation of various conditions. In line with the increase in MRI applications, the use of cardiac implantable electronic devices (CIED) is growing and many of the CEID recipients of today may require MRI examinations in the future. Traditionally, MRI examination of CIED recipients has been considered a contraindication. However, recent studies have provided strong evidence that MRI can safely be performed in selected patients with specific precautions. This review highlights the interactions of MRI with CIEDs, summarizes the literature, and outlines the Johns Hopkins Safety Protocol. PMID:26026996

  19. Neural circuitry involved in quitting after repeated failures: role of the cingulate and temporal parietal junction

    PubMed Central

    Zhao, Weihua; Kendrick, Keith M; Chen, Fei; Li, Hong; Feng, Tingyong

    2016-01-01

    The more times people fail the more likely they are to give up, however little is known about the neural mechanisms underlying this impact of repeated failure on decision making. Here we have used a visual shape discrimination task with computer-controlled feedback combined with functional magnetic resonance imaging (fMRI) to investigate the neural circuits involved. The behavioral task confirmed that the more times subjects experienced failure the more likely they were to give up, with three successive failures being the key threshold and the majority of subjects reaching the point where they decided to quit and try a new stimulus set after three or four failures. The fMRI analysis revealed activity changes in frontal, parietal, temporal, limbic and striatal regions, especially anterior cingulate cortex (ACC), posterior cingulate cortex (PCC) and temporal parietal junction (TPJ) associated with the number of previous failures experienced. Furthermore, their parameter estimates were predictive of subjects’ quitting rate. Thus, subjects reach the point where they decide to quit after three/four failures and this is associated with differential changes in brain regions involved in error monitoring and reward which regulate both failure detection and changes in decision-making strategy. PMID:27097529

  20. Transition from Collisionless to Collisional MRI

    SciTech Connect

    Prateek Sharma; Gregory W. Hammett; Eliot Quataert

    2003-07-24

    Recent calculations by Quataert et al. (2002) found that the growth rates of the magnetorotational instability (MRI) in a collisionless plasma can differ significantly from those calculated using MHD. This can be important in hot accretion flows around compact objects. In this paper, we study the transition from the collisionless kinetic regime to the collisional MHD regime, mapping out the dependence of the MRI growth rate on collisionality. A kinetic closure scheme for a magnetized plasma is used that includes the effect of collisions via a BGK operator. The transition to MHD occurs as the mean free path becomes short compared to the parallel wavelength 2*/k(sub)||. In the weak magnetic field regime where the Alfven and MRI frequencies w are small compared to the sound wave frequency k(sub)||c(sub)0, the dynamics are still effectively collisionless even if omega << v, so long as the collision frequency v << k(sub)||c(sub)0; for an accretion flow this requires n less than or approximately equal to *(square root of b). The low collisionality regime not only modifies the MRI growth rate, but also introduces collisionless Landau or Barnes damping of long wavelength modes, which may be important for the nonlinear saturation of the MRI.