Power of the Wilcoxon-Mann-Whitney test for non-inferiority in the presence of death-censored observations.

In clinical trials with patients in a critical state, death may preclude measurement of a quantitative endpoint of interest, and even early measurements, for example for intention-to-treat analysis, may not be available. For example, a non-negligible proportion of patients with acute pulmonary embolism will die before 30 day measurements on the efficacy of thrombolysis can be obtained. As excluding such patients may introduce bias, alternative analyses, and corresponding means for sample size calculation are needed.

How Low Can You Go? Low Densities of Poly(ethylene glycol) Surfactants Attract Stealth Proteins.

It is now well-established that the surface chemistry and "stealth" surface functionalities such as poly(ethylene glycol) (PEG) chains of nanocarriers play an important role to decrease unspecific protein adsorption of opsonizing proteins, to increase the enrichment of specific stealth proteins, and to prolong the circulation times of the nanocarriers. At the same time, PEG chains are used to provide colloidal stability for the nanoparticles. However, it is not clear how the chain length and density influence the unspecific and specific protein adsorption keeping at the same time the stability of the nanoparticles in a biological environment.

Direct pericyte-to-neuron reprogramming via unfolding of a neural stem cell-like program.

Ectopic expression of defined transcription factors can force direct cell-fate conversion from one lineage to another in the absence of cell division. Several transcription factor cocktails have enabled successful reprogramming of various somatic cell types into induced neurons (iNs) of distinct neurotransmitter phenotype. However, the nature of the intermediate states that drive the reprogramming trajectory toward distinct iN types is largely unknown.

Engineering Proteins at Interfaces: From Complementary Characterization to Material Surfaces with Designed Functions.

Once materials come into contact with a biological fluid containing proteins, proteins are generally-whether desired or not-attracted by the material's surface and adsorb onto it. The aim of this Review is to give an overview of the most commonly used characterization methods employed to gain a better understanding of the adsorption processes on either planar or curved surfaces. We continue to illustrate the benefit of combining different methods to different surface geometries of the material.

A DAG-based comparison of interventional effect underestimation between composite endpoint and multi-state analysis in cardiovascular trials.

Background: Composite endpoints comprising hospital admissions and death are the primary outcome in many cardiovascular clinical trials. For statistical analysis, a Cox proportional hazards model for the time to first event is commonly applied. There is an ongoing debate on whether multiple episodes per individual should be incorporated into the primary analysis.

Regulation of Alpha-Secretase ADAM10 and : Genetic, Epigenetic, and Protein-Based Mechanisms.

ADAM10 (A Disintegrin and Metalloproteinase 10) has been identified as the major physiological alpha-secretase in neurons, responsible for cleaving APP in a non-amyloidogenic manner. This cleavage results in the production of a neuroprotective APP-derived fragment, APPs-alpha, and an attenuated production of neurotoxic A-beta peptides. An increase in ADAM10 activity shifts the balance of APP processing toward APPs-alpha and protects the brain from amyloid deposition and disease.

Feasibility of sample size calculation for RNA-seq studies.

Sample size calculation is a crucial step in study design but is not yet fully established for RNA sequencing (RNA-seq) analyses. To evaluate feasibility and provide guidance, we evaluated RNA-seq sample size tools identified from a systematic search. The focus was on whether real pilot data would be needed for reliable results and on identifying tools that would perform well in scenarios with different levels of biological heterogeneity and fold changes (FCs) between conditions.

Quantification of Radiation Biomarkers in Leukocytes of Breast Cancer Patients Treated with Different Modalities of 3D-CRT or IMRT.

The goal of this study was to determine whether the quantification of radiation biomarkers in peripheral leukocytes of 111 breast cancer patients after adjuvant treatment with different modalities of three-dimensional conformal radiation therapy (3D-CRT) or intensity-modulated radiation therapy (IMRT) revealed any difference in the patients' radiation burden by out-of-field doses and an associated risk of second malignancies. Whole-breast radiation therapy was performed by 3D-CRT using either a hard wedge (n = 32) or a virtual wedge (n = 49) at dose rates of 3 and 6 Gy per min each. Patients receiving additional radiotherapy to lymph nodes were treated by 3D-CRT (n = 21) or IMRT (n = 9).

Evaluating patients for psychosocial distress and supportive care needs based on health-related quality of life in primary brain tumors: a prospective multicenter analysis of patients with gliomas in an outpatient setting.

The association between health-related quality of life (HRQoL), psychosocial distress, and supportive care is in the focus of patient-centered neuro-oncology. We investigated the relationship between the aforementioned in glioma-patients to evaluate the association of these instruments and determine cut-off values for suitable HRQoL scales indicating a potential need for intervention. In an observational multi-center study, outpatients completed the Distress Thermometer (DT), EORTC Quality of Life Questionnaire (EORTC-QLQ-C30/BN20, HRQoL), and Supportive-Care-Needs-Survey-SF34-G (SCNS).

Integrating multiple molecular sources into a clinical risk prediction signature by extracting complementary information.

Background: High-throughput technology allows for genome-wide measurements at different molecular levels for the same patient, e.g. single nucleotide polymorphisms (SNPs) and gene expression.

Rescue of Hypovitaminosis A Induces Non-Amyloidogenic Amyloid Precursor Protein (APP) Processing.

Retinoic acid, the bioactive metabolite of beta-carotene or vitamin A, plays a pleiotropic, multifunctional role in vertebrate development. Studies in rodents revealed that a diet deficient in vitamin A results in a complex neonatal syndrome (the VAD syndrome), manifested in many organs. In humans, the function of retinoic acid (RA) extends into adulthood, where it has important roles in fertility, vision, and suppression of neoplastic growth.

Identifying Prognostic SNPs in Clinical Cohorts: Complementing Univariate Analyses by Resampling and Multivariable Modeling.

Clinical cohorts with time-to-event endpoints are increasingly characterized by measurements of a number of single nucleotide polymorphisms that is by a magnitude larger than the number of measurements typically considered at the gene level. At the same time, the size of clinical cohorts often is still limited, calling for novel analysis strategies for identifying potentially prognostic SNPs that can help to better characterize disease processes. We propose such a strategy, drawing on univariate testing ideas from epidemiological case-controls studies on the one hand, and multivariable regression techniques as developed for gene expression data on the other hand.

Amphiphilic Copolymers Shuttle Drugs Across the Blood-Brain Barrier.

Medical treatment of diseases of the central nervous system requires transport of drugs across the blood-brain barrier (BBB). Here, it is extended previously in vitro experiments with a model compound to show that the non-water-soluble and brain-impermeable drug domperidone (DOM) itself can be enriched in the brain by use of an amphiphilic copolymer as a carrier. This carrier consists of poly(N-(2-hydroxypropyl)-methacrylamide), statistically copolymerized with 10 mol% hydrophobic lauryl methacrylate, into whose micellar aggregates DOM is noncovalently absorbed.

In Vivo Reprogramming for Brain and Spinal Cord Repair.

Cell reprogramming technologies have enabled the generation of various specific cell types including neurons from readily accessible patient cells, such as skin fibroblasts, providing an intriguing novel cell source for autologous cell transplantation. However, cell transplantation faces several difficult hurdles such as cell production and purification, long-term survival, and functional integration after transplantation. Recently, in vivo reprogramming, which makes use of endogenous cells for regeneration purpose, emerged as a new approach to circumvent cell transplantation.

Radiotherapy with BRAF inhibitor therapy for melanoma: progress and possibilities.

The introduction of small molecule BRAF(V600) kinase inhibitors represents a milestone in the targeted therapy of patients with metastatic melanoma by a significant increase in therapeutic efficacy in terms of overall and progression-free survival compared with conventional chemotherapy. Beside BRAF(V600) inhibitor treatment, radiotherapy is a further mainstay for the therapy of metastatic melanoma and thus a concomitant or sequential application of BRAF(V600) inhibitors and radiotherapy is inevitable. Recent reports show a significant radiosensitization of the irradiated healthy tissue in patients with melanoma after the combination of radiotherapy and BRAF(V600) inhibitors, evoking concern in clinical practice.

Gene expression patterns underlying parasite-induced alterations in host behaviour and life history.

Many parasites manipulate their hosts' phenotype. In particular, parasites with complex life cycles take control of their intermediate hosts' behaviour and life history to increase transmission to their definitive host. The proximate mechanisms underlying these parasite-induced alterations are poorly understood.

Imported Stem Cells Strike against Stroke.

Cells with neural stem cell (NSC)-like properties can be isolated from the cortex of adult brains following injury, but their origins and function are unclear. Now in Cell Stem Cell, Faiz et al. (2015) show that subventricular-zone-derived NSCs home to injured cortical area following stroke, where they generate reactive astrocytes.

Pitfalls of hypothesis tests and model selection on bootstrap samples: Causes and consequences in biometrical applications.

The bootstrap method has become a widely used tool applied in diverse areas where results based on asymptotic theory are scarce. It can be applied, for example, for assessing the variance of a statistic, a quantile of interest or for significance testing by resampling from the null hypothesis. Recently, some approaches have been proposed in the biometrical field where hypothesis testing or model selection is performed on a bootstrap sample as if it were the original sample.

Simulating recurrent event data with hazard functions defined on a total time scale.

Background: In medical studies with recurrent event data a total time scale perspective is often needed to adequately reflect disease mechanisms. This means that the hazard process is defined on the time since some starting point, e.g.

Biodosimetry Based on γ-H2AX Quantification and Cytogenetics after Partial- and Total-Body Irradiation during Fractionated Radiotherapy.

The aim of this current study was to quantitatively describe radiation-induced DNA damage and its distribution in leukocytes of cancer patients after fractionated partial- or total-body radiotherapy. Specifically, the impact of exposed anatomic region and administered dose was investigated in breast and prostate cancer patients receiving partial-body radiotherapy. DNA double-strand breaks (DSBs) were quantified by γ-H2AX immunostaining.

Ascl1 Coordinately Regulates Gene Expression and the Chromatin Landscape during Neurogenesis.

The proneural transcription factor Ascl1 coordinates gene expression in both proliferating and differentiating progenitors along the neuronal lineage. Here, we used a cellular model of neurogenesis to investigate how Ascl1 interacts with the chromatin landscape to regulate gene expression when promoting neuronal differentiation. We find that Ascl1 binding occurs mostly at distal enhancers and is associated with activation of gene transcription.

Identification of trichlormethiazide as a Mdr1a/b gene expression enhancer via a dual secretion-based promoter assay.

Transporters of the ATP-binding cassette (ABC) family such as MDR1 play a pivotal role in persistence of brain homeostasis by contributing to the strict permeability properties of the blood-brain barrier. This barrier on one hand compromises treatment of central nervous system diseases by restricting access of drugs; on the other hand, an impaired or altered function of barrier building cells has been described in neurological disorders. The latter might contribute to increased vulnerability of the brain under pathological conditions or even enforce pathogenesis.

In-TOX-icating neurogenesis.

Early development of the mammalian cerebral cortex proceeds via a sequence of proliferative and differentiative steps from neural stem cells toward neurons and glia. However, how these steps are molecularly orchestrated is still only partially understood. In this issue of The EMBO Journal, Artegiani and colleagues implicate Tox, a HMG-box transcription factor previously known only for its role in lymphocyte development, in early cortical development.