bluuebunny/crossref_metadata_2025_split huggingface dataset:
Psoralen–narrowband UVB phototherapy for the treatment of vitiligo in comparison to narrowband UVB alone
Authors: Bansal Shivani , Sahoo Bijaylaxmi , Garg Vijay 
Published: September 2013

SummaryBackgroundThe potential of psoralen–narrowband ultraviolet B (NBUVB) photochemotherapy has been investigated in vitiligo. The present study aims to evaluate the efficacy of psoralen–NBUVB (P‐NBUVB) vs. NBUVB in vitiligo.MethodsIn a randomized study, 45 Indian patients (age above 13 years) with vitiligo involving more than 5% body surface area were randomly allocated to receive either NBUVB or P‐NBUVB treatment. Both groups received NBUVB exposure thrice weekly, with a total of 60 sessions. The extent of repigmentation achieved was calculated on the basis of Vitiligo Area Severity Index (VASI) scoring.ResultsForty patients were available for analysis at the end of the study. The extent of repigmentation in the P‐NBUVB group was statistically significantly greater in face and neck (P = 0.006, t‐test) and hands (P = 0.007, t‐test) in comparison with the NBUVB group (t‐test). Percentage reduction in VASI scores was statistically significantly greater in the P‐NBUVB group (29.2% vs. 21.7%, P = 0.043, t‐test). The response to P‐NBUVB therapy started earlier than the response to NBUVB. After excluding sunlight as a confounding factor, treatment response was also significantly better in the P‐NBUVB group (P = 0.005).ConclusionAddition of psoralen increased the extent of repigmentation due to NBUVB therapy in vitiligo. Further studies are required to determine the long‐term efficacy and safety of P‐NBUVB.
A Model-Based Framework for Air Quality Indices and Population Risk Evaluation, with an Application to the Analysis of Scottish Air Quality Data
Authors: Finazzi Francesco , Scott E. Marian , Fassò Alessandro 
Published: September 2013

SummaryThe paper is devoted to the development of a statistical framework for air quality assessment at the country level and for the evaluation of the ambient population exposure and risk with respect to airborne pollutants. The framework is based on a multivariate space–time model and on aggregated indices defined at different levels of aggregation in space and time. The indices are evaluated, uncertainty included, by considering both the model outputs and the information on the population spatial distribution. The framework is applied to the analysis of air quality data for Scotland for 2009 referring to European and Scottish air quality legislation.
Locally Adaptive Spatial Smoothing Using Conditional Auto-Regressive Models
Authors: Lee Duncan , Mitchell Richard 
Published: September 2013

SummaryConditional auto-regressive models are commonly used to capture spatial cor relation in areal unit data, as part of a hierarchical Bayesian model. The spatial correlation structure that is induced by these models is determined by geographical adjacency, but this is too simplistic for some real data sets, which can visually exhibit subregions of strong correlation as well as locations at which the response exhibits a step change. An example of this, and the motivation for the paper, is the spatial pattern in respiratory disease risk in the 271 intermed iate geographies in the Greater Glasgow and Clyde Health Board in 2005. The methodology proposed is an extension to the class of conditional auto-regressive priors, which allow them to capture such localized spatial correlation and to identify step changes. The approach takes the form of an iterative algorithm, which sequentially updates the spatial correlation structure that is assumed by the model in addition to estimating the remaining parameters. The efficacy of the approach is assessed by simulation, before being applied to the motivating Greater Glasgow application.
A Penalized Likelihood Approach to Estimate Within-Household Contact Networks from Egocentric Data
Authors: Potter Gail E. , Hens Niel 
Published: September 2013

SummaryAcute infectious diseases are transmitted over networks of social contacts. Epidemic models are used to predict the spread of emergent pathogens and to compare intervention strategies. Many of these models assume equal probability of contact within mixing groups (homes, schools, etc.), but little work has inferred the actual contact network, which may influence epidemic estimates. We develop a penalized likelihood method to infer contact networks within households, which are a key area for disease transmission. Using egocentric surveys of contact behaviour in Belgium, we estimate within-household contact networks for six different age compositions. Our estimates show dependence in contact behaviour and vary substantively by age composition, with fewer contacts in older households. Our results are relevant for epidemic models that are used to make policy recommendations.
The Item Count Method for Sensitive Survey Questions: Modelling Criminal Behaviour
Authors: Kuha Jouni , Jackson Jonathan 
Published: September 2013

SummaryThe item count method is a way of asking sensitive survey questions which protects the anonymity of the respondents by randomization before the interview. It can be used to estimate the probability of sensitive behaviour and to model how it depends on explanatory variables. We analyse item count survey data on the illegal behaviour of buying stolen goods. The analysis of an item count question is best formulated as an instance of modelling incomplete categorical data. We propose an efficient implementation of the estimation which also provides explicit variance estimates for the parameters. We then suggest specifications for the model for the control items, which is an auxiliary but unavoidable part of the analysis of item count data. These considerations and the results of our analysis of criminal behaviour highlight the fact that careful design of the questions is crucial for the success of the item count method.
Semiparametric Bayesian Models for Clustering and Classification in the Presence of Unbalanced In-Hospital Survival
Authors: Guglielmi Alessandra , Ieva Francesca , Paganoni Anna M. , Ruggeri Fabrizio , Soriano Jacopo 
Published: September 2013

Summary
Bayesian semiparametric logit models are fitted to grouped data related to in-hospital survival outcome of patients hospitalized with an ST-segment elevation myocardial infarction diagnosis. Dependent Dirichlet process priors are considered for modelling the random-effects distribution of the grouping factor (hospital of admission), to provide a cluster analysis of the hospitals. The clustering structure is highlighted through the optimal random partition that minimizes the posterior expected value of a suitable loss function. There are two main goals of the work: to provide model-based clustering and ranking of the providers according to the similarity of their effect on patients' outcomes, and to make reliable predictions on the survival outcome at the patient's level, even when the survival rate itself is strongly unbalanced. The study is within a project, named the ‘Strategic program of Regione Lombardia’, and is aimed at supporting decisions in healthcare policies.
Estimating Disease Onset Distribution Functions in Mutation Carriers with Censored Mixture Data
Authors: Ma Yanyuan , Wang Yuanjia 
Published: September 2013

Summary
We consider non-parametric estimation of disease onset distribution functions in multiple populations by using censored data with unknown population identifiers. The problem is motivated from studies aiming at estimating the age-specific disease risk distribution in deleterious mutation carriers for genetic counselling and design of therapeutic intervention trials to modify disease progression (i.e. to slow down the development of symptoms and to delay the onset of disease). In some of these studies, the distribution of disease risk in participants assumes a mixture form. Although the population identifiers are missing, study design and scientific knowledge allow calculation of the probability of a subject belonging to each population. We propose a general family of weighted least squares estimators and show that existing consistent non-parametric methods belong to this family. We identify a computationally effortless estimator in the family, study its asymptotic properties and show its significant gain in efficiency compared with the existing estimators in the literature. The application to a large genetic epidemiological study of Huntington's disease reveals information on the age-at-onset distribution of Huntington's disease which sheds light on some clinical hypotheses.
A Factor Mixture Model for Multivariate Survival Data: An Application to the Analysis of Lifetime Mental Disorders
Authors: Almansa Josué , Vermunt Jeroen K. , Forero Carlos G. , Alonso Jordi 
Published: September 2013

SummaryThe assessment of the lifetime prevalence of mental disorders under comorbidity conditions is an important area in mental health research. Because information on lifetime disorders is usually gathered retrospectively within cross-sectional studies, the information is necessarily right censored and this should be taken into account when setting up models for the estimation of lifetime prevalences. We propose a factor analytic discrete time survival model combining mixture item response theory and discrete time hazard functions to describe disorder associations while accounting for censoring. This model is used for describing the lifetime prevalence and comorbidity of eight depression and anxiety disorders from the European Study of the Epidemiology of Mental Disorders.
Improving Outcomes in Patients with Lupus and End‐Stage Renal Disease
Authors: Inda‐Filho Antonio , Neugarten Joel , Putterman Chaim , Broder Anna 
Published: September 2013

AbstractThe development of lupus‐related end‐stage renal disease (ESRD) confers the highest mortality rates among individuals with lupus. Lupus‐related ESRD is also associated with higher morbidity and mortality rates compared with non‐lupus ESRD. We review the evidence that persistent lupus activity, hypercoagulability, and continuing immunosuppression may contribute to unfavorable outcomes in dialysis and renal transplantation among lupus patients. Robust epidemiologic studies are needed to develop individualized evidence‐based approaches to treating lupus‐related ESRD. In the meantime, managing lupus‐related ESRD presents a significant challenge for clinicians and requires a team approach involving nephrologists and rheumatologists. Goals of therapy after developing ESRD should include continuing monitoring of lupus activity, minimizing corticosteroid exposure, and choosing the most appropriate renal replacement therapy based on patient's risk profile and quality‐of‐life considerations.
Reduction in facial hyperpigmentation after treatment with a combination of topical niacinamide and tranexamic acid: a randomized, double‐blind, vehicle‐controlled trial
Authors: Lee Do Hyun , Oh In Young , Koo Kyo Tan , Suk Jang Mi , Jung Sang Wook , Park Jin Oh , Kim Beom Joon , Choi Yoo Mi 
Published: September 2013

BackgroundFacial hyperpigmentation occurs in multiple conditions. In addition, many Asian women desire a lighter skin color. Thus, there is a need for the development of skin lightening agents, and niacinamide and tranexamic acid (TXA) are promising candidates.ObjectiveTo assess the effectiveness of a combination of niacinamide and TXA as a topical moisturizing formulation for treatment of irregular facial pigmentation.Materials and MethodsA total of 42 Korean women (age range: 30–60 years) who were not pregnant, nursing, or undergoing any concurrent therapy were enrolled in this study for 8 weeks. Subjects used a twice‐daily regimen of either a moisturizing cream containing 2% niacinamide + 2% TXA (test formulation; n = 21) or cream vehicles (vehicle control; n = 21) in addition to an assigned sunscreen each morning. Pigmentation was measured objectively using a mexameter and chromameter, in addition to physicians' assessment using clinical photographs.ResultsThe niacinamide + TXA formulation regimen was significantly (P < 0.05) more effective than the vehicle control formulation regimen in reducing the appearance of pigmentation.ConclusionA formulation containing the combination of niacinamide + TXA reduced the appearance of irregular pigmentation, providing an effect beyond that achieved with sunscreen.
Direct reconstruction of cardiac PET kinetic parametric images using a preconditioned conjugate gradient approach
Authors: Rakvongthai Yothin , Ouyang Jinsong , Guerin Bastien , Li Quanzheng , Alpert Nathaniel M. , El Fakhri Georges 
Published: September 2013

Purpose:Our research goal is to develop an algorithm to reconstruct cardiac positron emission tomography (PET) kinetic parametric images directly from sinograms and compare its performance with the conventional indirect approach.Methods:Time activity curves of a NCAT phantom were computed according to a one‐tissue compartmental kinetic model with realistic kinetic parameters. The sinograms at each time frame were simulated using the activity distribution for the time frame. The authors reconstructed the parametric images directly from the sinograms by optimizing a cost function, which included the Poisson log‐likelihood and a spatial regularization terms, using the preconditioned conjugate gradient (PCG) algorithm with the proposed preconditioner. The proposed preconditioner is a diagonal matrix whose diagonal entries are the ratio of the parameter and the sensitivity of the radioactivity associated with parameter. The authors compared the reconstructed parametric images using the direct approach with those reconstructed using the conventional indirect approach.Results:At the same bias, the direct approach yielded significant relative reduction in standard deviation by 12%–29% and 32%–70% for 50 × 106 and 10 × 106 detected coincidences counts, respectively. Also, the PCG method effectively reached a constant value after only 10 iterations (with numerical convergence achieved after 40–50 iterations), while more than 500 iterations were needed for CG.Conclusions:The authors have developed a novel approach based on the PCG algorithm to directly reconstruct cardiac PET parametric images from sinograms, and yield better estimation of kinetic parameters than the conventional indirect approach, i.e., curve fitting of reconstructed images. The PCG method increases the convergence rate of reconstruction significantly as compared to the conventional CG method.
Acute HIV-1 Seroconversion with an Unusual Plasma Biomarker Profile
Authors: Aziz Najib , Detels Roger , Martinez-Maza Otoniel , Oishi John , Jamieson Beth D. , Witt Mallory D. , Butch Anthony W. 
Published: September 2013

ABSTRACT
An unusual case of acute primary HIV-1 infection in a man with a high plasma viral load, a 51-fold increase in C-reactive protein, and antibodies against only gp160 is described. Numerous serum cytokine concentrations were elevated during HIV-1 seroconversion.
A Novel Line Immunoassay Based on Recombinant Virulence Factors Enables Highly Specific and Sensitive Serologic Diagnosis of Helicobacter pylori Infection
Authors: Formichella Luca , Romberg Laura , Bolz Christian , Vieth Michael , Geppert Michael , Göttner Gereon , Nölting Christina , Walter Dirk , Schepp Wolfgang , Schneider Arne , Ulm Kurt , Wolf Petra , Busch Dirk H. , Soutschek Erwin , Gerhard Markus 
Published: September 2013

ABSTRACT

Helicobacter pylori
colonizes half of the world's population, and infection can lead to ulcers, gastric cancer, and mucosa-associated lymphoid tissue (MALT) lymphoma. Serology is the only test applicable for large-scale, population-based screening, but current tests are hampered by a lack of sensitivity and/or specificity. Also, no serologic test allows the differentiation of type I and type II strains, which is important for predicting the clinical outcome.
H. pylori
virulence factors have been associated with disease, but direct assessment of virulence factors requires invasive methods to obtain gastric biopsy specimens. Our work aimed at the development of a highly sensitive and specific, noninvasive serologic test to detect immune responses to important
H. pylori
virulence factors. This line immunoassay system (
recom
Line) is based on recombinant proteins. For this assay, six highly immunogenic virulence factors (CagA, VacA, GroEL, gGT, HcpC, and UreA) were expressed in
Escherichia coli
, purified, and immobilized to nitrocellulose membranes to detect serological immune responses in patient's sera. For the validation of the line assay, a cohort of 500 patients was screened, of which 290 (58.0%) were
H. pylori
negative and 210 (42.0%) were positive by histology. The assay showed sensitivity and specificity of 97.6% and 96.2%, respectively, compared to histology. In direct comparison to lysate blotting and enzyme-linked immunosorbent assay (ELISA), the
recom
Line assay had increased discriminatory power. For the assessment of individual risk for gastrointestinal disease, the test must be validated in a larger and defined patient cohort. Taking the data together, the
recom
Line assay provides a valuable tool for the diagnosis of
H. pylori
infection.
Detection of Colonization by Carbapenemase-Producing Gram-Negative Bacilli in Patients by Use of the Xpert MDRO Assay
Authors: Tenover Fred C. , Canton Rafael , Kop JoAnn , Chan Ryan , Ryan Jamie , Weir Fred , Ruiz-Garbajosa Patricia , LaBombardi Vincent , Persing David H. 
Published: September 2013

ABSTRACT

Detecting colonization of patients with carbapenemase-producing bacteria can be difficult. This study compared the sensitivity and specificity of a PCR-based method (Xpert MDRO) for detecting
bla
KPC
,
bla
NDM
, and
bla
VIM
carbapenem resistance genes using GeneXpert cartridges to the results of culture with and without a broth enrichment step on 328 rectal, perirectal, and stool samples. The culture method included direct inoculation of a MacConkey agar plate on which a 10-μg meropenem disk was placed and plating on MacConkey agar after overnight enrichment of the sample in MacConkey broth containing 1 μg/ml of meropenem. Forty-three (13.1%) samples were positive by PCR for
bla
KPC
and 11 (3.4%) were positive for
bla
VIM
; none were positive for
bla
NDM
. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the PCR assay for
bla
KPC
were 100%, 99.0%, 93.0%, and 100%, respectively, compared to broth enrichment culture and sequencing of target genes. The sensitivity, specificity, PPV, and NPV of the assay for
bla
VIM
were 100%, 99.4%, 81.8%, and 100%, respectively. Since none of the clinical samples contained organisms with
bla
NDM
, 66 contrived stool samples were prepared at various dilutions using three
Klebsiella pneumoniae
isolates containing
bla
NDM
. The PCR assay showed 100% positivity at dilutions from 300 to 1,800 CFU/ml and 93.3% at 150 CFU/ml. The Xpert MDRO PCR assay required 2 min of hands-on time and 47 min to complete. Rapid identification of patients colonized with carbapenemase-producing organisms using multiplex PCR may help hospitals to improve infection control activities.
Comparison of Six Real-Time PCR Assays for Qualitative Detection of Cytomegalovirus in Clinical Specimens
Authors: Binnicker M. J. , Espy M. E. 
Published: September 2013

ABSTRACT

In this study, we compared the performance of six real-time PCR assays for the qualitative detection of cytomegalovirus (CMV) in clinical samples other than plasma. Two hundred specimens (respiratory [
n
= 72], urine [
n
= 67], cerebrospinal fluid [CSF] [
n
= 25], tissue [
n
= 18], amniotic fluid [
n
= 10], and bone marrow [
n
= 8]) submitted for routine testing by CMV real-time PCR analyte-specific reagents (ASR) (Roche Diagnostics, Indianapolis, IN) were also tested by a laboratory-developed test (LDT) and 4 commercially available PCR assays: EraGen Multicode (Luminex, Austin, TX), Focus Simplexa (Focus Diagnostics, Cypress, CA), Elitech MGB Alert CMV (Fisher Scientific, Hanover Park, IL), and Abbott CMV (Abbott Park, IL). Nucleic acid was extracted using the MagNA Pure system (Roche Diagnostics) and subsequently tested by each PCR method. Results were analyzed by comparing each assay to a “consensus result,” which was defined as the result obtained from at least 4 of the 6 assays. In addition to the prospective samples, 13 lower respiratory samples with known positive results by CMV shell vial were tested by each PCR method. Following testing of the 200 prospective specimens, the Abbott, Elitech, EraGen, and Focus PCR assays demonstrated a sensitivity of 100% (46/46), while the Roche analyte-specific reagents (ASR) and LDT showed sensitivities of 89% (41/46) and 98% (45/46), respectively. Percent specificities ranged from 97% (149/154) by Elitech to 100% (154/154) by the LDT. Among the 13 shell vial-positive lower respiratory samples, the percent sensitivities ranged from 69% (9/13) by Elitech to 92% (12/13) by the LDT. The Abbott, EraGen, Elitech, Focus, and LDT PCR assays performed similarly (κ ≥ 0.89) for the detection of CMV in clinical specimens and demonstrated increased sensitivity compared to the Roche ASR.
Human Herpesvirus 6A Infection and Immunopathogenesis in Humanized Rag2−/−γc−/−Mice
Authors: Tanner Anne , Carlson Stephanie A. , Nukui Masatoshi , Murphy Eain A. , Berges Bradford K. 
Published: September 2013

ABSTRACTAlthough serious human diseases have been correlated with human herpesvirus 6A (HHV-6A) and HHV-6B, the lack of animal models has prevented studies which would more definitively link these viral infections to disease. HHV-6A and HHV-6B have recently been classified as two distinct viruses, and in this study we focused specifically on developing anin vivomodel for HHV-6A. Here we show that Rag2−/−γc−/−mice humanized with cord blood-derived human hematopoietic stem cells produce human T cells that express the major HHV-6A receptor, CD46. Both cell-associated and cell-free viral transmission of HHV-6A into the peritoneal cavity resulted in detectable viral DNA in at least one of the samples (blood, bone marrow, etc.) analyzed from nearly all engrafted mice. Organs and cells positive for HHV-6A DNA were the plasma and cellular blood fractions, bone marrow, lymph node, and thymic samples; control mice had undetectable viral DNA. We also noted viral pathogenic effects on certain T cell populations. Specific thymocyte populations, including CD3−CD4+CD8−and CD3+CD4−cells, were significantly modified in humanized mice infected by cell-associated transmission. In addition, we detected significantly increased proportions of CD4+CD8+cells in the blood of animals infected by cell-free transmission. These findings provide additional evidence that HHV-6A may play a role in human immunodeficiencies. These results indicate that humanized mice can be used to study HHV-6Ain vivoinfection and replication as well as aspects of viral pathogenesis.