Addressing issues associated with evaluating prediction models for survival endpoints based on the concordance statistic.

Prediction models for disease risk and prognosis play an important role in biomedical research, and evaluating their predictive accuracy in the presence of censored data is of substantial interest. The standard concordance (c) statistic has been extended to provide a summary measure of predictive accuracy for survival models. Motivated by a prostate cancer study, we address several issues associated with evaluating survival prediction models based on c-statistic with a focus on estimators using the technique of inverse probability of censoring weighting (IPCW).

Hierarchical Feature Selection Incorporating Known and Novel Biological Information: Identifying Genomic Features Related to Prostate Cancer Recurrence.

Our work is motivated by a prostate cancer study aimed at identifying mRNA and miRNA biomarkers that are predictive of cancer recurrence after prostatectomy. It has been shown in the literature that incorporating known biological information on pathway memberships and interactions among biomarkers improves feature selection of high-dimensional biomarkers in relation to disease risk. Biological information is often represented by graphs or networks, in which biomarkers are represented by nodes and interactions among them are represented by edges; however, biological information is often not fully known.

Model selection and inference for censored lifetime medical expenditures.

Identifying factors associated with increased medical cost is important for many micro- and macro-institutions, including the national economy and public health, insurers and the insured. However, assembling comprehensive national databases that include both the cost and individual-level predictors can prove challenging. Alternatively, one can use data from smaller studies with the understanding that conclusions drawn from such analyses may be limited to the participant population.

Doubly robust multiple imputation using kernel-based techniques.

We consider the problem of estimating the marginal mean of an incompletely observed variable and develop a multiple imputation approach. Using fully observed predictors, we first establish two working models: one predicts the missing outcome variable, and the other predicts the probability of missingness. The predictive scores from the two models are used to measure the similarity between the incomplete and observed cases.

Transient Activation of Mitoflashes Modulates Nanog at the Early Phase of Somatic Cell Reprogramming.

The mechanisms of somatic cell reprogramming have been revealed at multiple levels. However, the lack of tools to monitor different reactive oxygen species (ROS) has left their distinct signals and roles in reprogramming unknown. We hypothesized that mitochondrial flashes (mitoflashes), recently identified spontaneous bursts of mitochondrial superoxide signaling, play a role in reprogramming.

IL-17 Induces MPTP opening through ERK2 and P53 signaling pathway in human platelets.

The opening of mitochondrial permeability transition pore (MPTP) plays a critical role in platelet activation. However, the potential trigger of the MPTP opening in platelet activation remains unknown. Inflammation is the crucial trigger of platelet activation.

18F-fluorodeoxyglucose positron emission tomography/computed tomography for primary thyroid langerhans histiocytosis: A case report and literature review.

Langerhans cell histiocytosis (LCH) is a rare clonal proliferative disease, with an incidence rate of 4.0-5.4/1 million individuals.

Modeling of Mitochondrial Donut Formation.

Mitochondria are highly dynamic cell organelles. Continual cycles of fusion and fission play an important role in mitochondrial metabolism and cellular signaling. Previously, a novel mitochondrial morphology, the donut, was reported in cells after hypoxia-reoxygenation or osmotic pressure changes.

B10 Cells Ameliorate the Progression of Lupus Nephritis by Attenuating Glomerular Endothelial Cell Injury.

Background/aim: B10 cells are generally considered to inhibit the kidney injury in systemic lupus erythematosus (SLE) mouse models, but recently this function of B10 cells was denied by the lineage-specific deletion of IL-10 from B cells. Thus, this study aimed to determine whether and how B10 cells play a protective role in lupus nephritis (LN).

Methods: LN and non-LN SLE patients without receiving any treatments were recruited, and the percentages of circulating B10 cell were determined.

Translating What Works: A New Approach to Improve Diabetes Management.

Background: The most efficacious strategies to improve diabetes control include case management, health care team changes, patient education, and facilitated transmission of patient data to clinicians ("facilitated relay"), but these strategies have not been translated to permit general use in clinical practice.

Methods: A web-based decision support program was developed to include these features, and assessed in patients who had A1c ≥7.0% despite using metformin with/without sulfonylureas or insulin.

Mitochondrial fusion provides an 'initial metabolic complementation' controlled by mtDNA.

Heteroplasmic cells, harboring both mutant and normal mitochondrial DNAs (mtDNAs), must accumulate mutations to a threshold level before respiratory activity is affected. This phenomenon has led to the hypothesis of mtDNA complementation by inter-mitochondrial content mixing. The precise mechanisms of heteroplasmic complementation are unknown, but it depends both on the mtDNA nucleoid dynamics among mitochondria as well as the mitochondrial dynamics as influenced by mtDNA.

Variable selection in the presence of missing data: resampling and imputation.

In the presence of missing data, variable selection methods need to be tailored to missing data mechanisms and statistical approaches used for handling missing data. We focus on the mechanism of missing at random and variable selection methods that can be combined with imputation. We investigate a general resampling approach (BI-SS) that combines bootstrap imputation and stability selection, the latter of which was developed for fully observed data.

Weight loss and incidence of diabetes with the Veterans Health Administration MOVE! lifestyle change programme: an observational study.

Background: Programmes for lifestyle change are aimed at improving health but little is known about their effectiveness in clinical settings. The Veterans Health Administration (VA) MOVE! lifestyle change programme is the largest in the USA. We investigated whether participation in MOVE! is associated with reduced incidence of diabetes.

Increased cardiovascular disease, resource use, and costs before the clinical diagnosis of diabetes in veterans in the southeastern U.S.

Importance: Screening for diabetes might be more widespread if adverse associations with cardiovascular disease (CVD), resource use, and costs were known to occur earlier than conventional clinical diagnosis.

Objective: The purpose of this study was to determine whether adverse effects associated with diabetes begin prior to clinical diagnosis.

Design: Veterans with diabetes were matched 1:2 with controls by follow-up, age, race/ethnicity, gender, and VA facility.

Valproic acid-induced hepatotoxicity in Alpers syndrome is associated with mitochondrial permeability transition pore opening-dependent apoptotic sensitivity in an induced pluripotent stem cell model.

Unlabelled: Valproic acid (VPA) is widely used to treat epilepsy, migraine, chronic headache, bipolar disorder, and as adjuvant chemotherapy, but potentially causes idiosyncratic liver injury. Alpers-Huttenlocher syndrome (AHS), a neurometabolic disorder caused by mutations in mitochondrial DNA polymerase gamma (POLG), is associated with an increased risk of developing fatal VPA hepatotoxicity. However, the mechanistic link of this clinical mystery remains unknown.

Clinical trial with traditional Chinese medicine intervention ''tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment'' for chronic hepatitis B-associated liver failure.

Aim: To study the clinical efficacy of traditional Chinese medicine (TCM) intervention "tonifying the kidney to promote liver regeneration and repair by affecting stem cells and their microenvironment" ("TTK") for treating liver failure due to chronic hepatitis B.

Methods: We designed the study as a randomized controlled clinical trial. Registration number of Chinese Clinical Trial Registry is ChiCTR-TRC-12002961.

Prediction of the sorption capacities and affinities of organic chemicals by XAD-7.

Macro-porous resins are widely used as adsorbents for the treatment of organic contaminants in wastewater and for the pre-concentration of organic solutes from water. However, the sorption mechanisms for organic contaminants on such adsorbents have not been systematically investigated so far. Therefore, in this study, the sorption capacities and affinities of 24 organic chemicals by XAD-7 were investigated and the experimentally obtained sorption isotherms were fitted to the Dubinin-Ashtakhov model.

Epithelium-Specific ETS (ESE)-1 upregulated GP73 expression in hepatocellular carcinoma cells.

Background: Golgi protein-73 (GP73) is a Golgi transmembrane glycoprotein elevated in numerous liver diseases. Clinically, GP73 is strongly elevated in the serum of HCC patients and is thus regarded as a novel potential biomarker for HCC. However, the mechanism leading to GP73 dysregulation in liver diseases remains unknown.

Bayesian modeling and prediction of accrual in multi-regional clinical trials.

In multi-regional trials, the underlying overall and region-specific accrual rates often do not hold constant over time and different regions could have different start-up times, which combined with initial jump in accrual within each region often leads to a discontinuous overall accrual rate, and these issues associated with multi-regional trials have not been adequately investigated. In this paper, we clarify the implication of the multi-regional nature on modeling and prediction of accrual in clinical trials and investigate a Bayesian approach for accrual modeling and prediction, which models region-specific accrual using a nonhomogeneous Poisson process and allows the underlying Poisson rate in each region to vary over time. The proposed approach can accommodate staggered start-up times and different initial accrual rates across regions/centers.

Temporal changes in serum biomarkers and risk for progression of gastric precancerous lesions: a longitudinal study.

Effectively managing precancerous lesions is crucial to reducing the gastric cancer (GC) burden. We evaluated associations of temporal changes in multiple serological markers (pepsinogen I [PGI], PGII, PGI/II ratio, gastrin-17 and anti-Helicobacter pylori IgG) with risk for progression of gastric precancerous lesions. From 1997 to 2011, repeated esophagogastroduodenoscopies with gastric mucosal biopsies and blood sample collections were conducted on 2,039 participants (5,070 person-visits) in the Zhuanghe Gastric Diseases Screening Program, Liaoning, China.

EphB2 contributes to human naive B-cell activation and is regulated by miR-185.

EphB2 is an important member of the receptor tyrosine kinases. Recently, EphB2 was shown to facilitate T-cell migration and monocyte activation. However, the effects of EphB2 on B cells remain unknown.

Global transcriptome analysis of formalin-fixed prostate cancer specimens identifies biomarkers of disease recurrence.

Prostate cancer remains the second leading cause of cancer death in American men and there is an unmet need for biomarkers to identify patients with aggressive disease. In an effort to identify biomarkers of recurrence, we performed global RNA sequencing on 106 formalin-fixed, paraffin-embedded prostatectomy samples from 100 patients at three independent sites, defining a 24-gene signature panel. The 24 genes in this panel function in cell-cycle progression, angiogenesis, hypoxia, apoptosis, PI3K signaling, steroid metabolism, translation, chromatin modification, and transcription.

A nonparametric multiple imputation approach for data with missing covariate values with application to colorectal adenoma data.

A nearest neighbor-based multiple imputation approach is proposed to recover missing covariate information using the predictive covariates while estimating the association between the outcome and the covariates. To conduct the imputation, two working models are fitted to define an imputing set. This approach is expected to be robust to the underlying distribution of the data.

[Early multi-disciplinary intervention reduces neurological disability in premature infants].

Objective: This study aimed to evaluate the effectiveness of multi-disciplinary treatment approaches in reducing neurological disabilities in premature infants.

Methods: A total of 117 infants who were born premature in our hospital between March 2008 and February 2010 but had no congenital malformations and no severe neonatal complications, were enrolled in this study. They were randomly allocated to a multi-disciplinary treatment group (n=63) and a control group (n=54).

Cardiac fibroblasts recruit Th17 cells infiltration into myocardium by secreting CCL20 in CVB3-induced acute viral myocarditis.

Aims: Th17 cells contributed to myocardial inflammatory injury in acute viral myocarditis (AVMC), and the migration of these cells were mainly mediated by CCL20-secreting inflammatory cells. However, whether and how the resident cells such as cardiomyocytes and cardiac fibroblasts could mediate Th17 cell migration into the heart remains unclear in AVMC.

Methods: The effect of CCL20 on the dynamic alterations of intracardiac Th17 cells and disease severity were investigated through the neutralization of CCL20 in AVMC mice.