Search results for " statistics"

Role of Hypoxia and the Adenosine System in Immune Evasion and Prognosis of Patients with Brain Metastases of Melanoma: A Multiplex Whole Slide Immun…

2020

Simple Summary The introduction of immune-checkpoint inhibitors improved the therapeutic landscape for patients with advanced malignant melanoma. However, many patients, including patients with melanoma brain metastases, do not derive benefit from immune-checkpoint blockade. Hence, biomarkers are needed to identify potential mechanisms of resistance and optimize patient selection. This study aimed to explore the role of hypoxia-mediated immunosuppression within the tumor microenvironment of patients with metastatic melanoma using multiplex immunofluorescence. We analyzed the prognostic relevance of the hypoxia surrogate marker GLUT-1, the adenosine-synthesizing ectoenzymes CD73/CD39, and th…

Reducing sample size in experiments with animals: historical controls and related strategies

2015

Reducing the number of animal subjects used in biomedical experiments is desirable for ethical and practical reasons. Previous reviews of the benefits of reducing sample sizes have focused on improving experimental designs and methods of statistical analysis, but reducing the size of control groups has been considered rarely. We discuss how the number of current control animals can be reduced, without loss of statistical power, by incorporating information from historical controls, i.e. subjects used as controls in similar previous experiments. Using example data from published reports, we describe how to incorporate information from historical controls under a range of assumptions that mig…

2018

The rapidly increasing interest in fitness related sports over the past few years has been accompanied by a booming industry of nutritional supplements. Many of these substances have unproven benefits and are even potentially harmful to the user. The aim of this study was to determine the prevalence and reasons for nutritional supplement (NS) use among fitness studio visitors in Mainz (Germany), emphasizing new multi-ingredient based supplements such as pre workout boosters (PWBs). Some of the PWBs contain stimulants such as DMAA, N,α-DEPEA, DMAE and DMBA with so far unknown risks, harms and benefits. Four-Hundred and Ninety Two participants in 13 fitness studios completed a questionnaire o…

Importance of rotary systems in dental care by undergraduate students in patients of a public health service of Belo Horizonte.

2015

Background: The aim of this study was to evaluate the fracture rates of ProTaper rotary files used in the endodontics extension clinic of the Undergraduate Dentistry Course of the Pontifical Catholic University of Minas Gerais during the prior eight years. Material and Methods: Control record data regarding file usage by students were collected and analyzed by semester. For each period, the total number of patient consultations, the frequency of file use, the occurrence of fractures and the file numbers for which fractures occurred were noted. Descriptive statistics, including frequency of file fractures were calculated for all file types. The chi-square test was used to evaluate difference…

Low-energy extracorporeal shockwave therapy (ESWT) improves metaphyseal fracture healing in an osteoporotic rat model.

2017

Purpose As result of the current demographic changes, osteoporosis and osteoporotic fractures are becoming an increasing social and economic burden. In this experimental study, extracorporeal shock wave therapy (ESWT), was evaluated as a treatment option for the improvement of osteoporotic fracture healing. Methods A well-established fracture model in the metaphyseal tibia in the osteoporotic rat was used. 132 animals were divided into 11 groups, with 12 animals each, consisting of one sham-operated group and 10 ovariectomized (osteoporotic) groups, of which 9 received ESWT treatment. Different energy flux intensities (0.15 mJ/mm2, 0.35 mJ/mm2, or 0.55 mJ/mm2) as well as different numbers o…

The colored longest common prefix array computed via sequential scans

2018

Due to the increased availability of large datasets of biological sequences, the tools for sequence comparison are now relying on efficient alignment-free approaches to a greater extent. Most of the alignment-free approaches require the computation of statistics of the sequences in the dataset. Such computations become impractical in internal memory when very large collections of long sequences are considered. In this paper, we present a new conceptual data structure, the colored longest common prefix array (cLCP), that allows to efficiently tackle several problems with an alignment-free approach. In fact, we show that such a data structure can be computed via sequential scans in semi-exter…

TM6SF2 rs58542926 is not associated with steatosis and fibrosis in largecohort of patients with genotype 1 chronic hepatitis C

2016

Background & Aims We tested the putative association of the rs58542926 variant of TM6SF2, a recently described genetic determinant of nonalcoholic fatty liver disease, with steatosis and fibrosis in genotype 1(G1) chronic hepatitis C(CHC) patients. Methods A total of 694 consecutively biopsied Caucasian G1 CHC patients were genotyped for TM6SF2 rs58542926, IL28B rs12979860 and PNPLA3 rs738409. Steatosis was classified as absent (<5%), mild-moderate(5–29%) and severe(≥30%), Fibrosis was considered severe if=F3-F4. Results Carriers of TM6SF2 rs58542926 (6.3% of patients) exhibited lower serum levels of cholesterol (P = 0.04) and triglycerides (P = 0.01), but a similar distribution of steatosi…

Protein supplement consumption is linked to time spent exercising and high-protein content foods: A multicentric observational study

2019

The main aim of this study is to analyze if protein supplement consumption and food patterns vary across three geographical regions and secondly to identify possible factors that increase the likelihood of ingesting protein supplements.A total of 916 responses from gym users of 3 countries (Italy, Turkey and UK) were entered for analysis. Questions were related to supplement consumption (protein and other supplements), food intake and training habits. A descriptive analysis, analysis of variance (ANOVA), and logistic regression were performed.No differences were found across groups regarding: prevalence of protein supplement consumption, typology of other ingested supplement and food intake…

A Dirichlet Autoregressive Model for the Analysis of Microbiota Time-Series Data

2021

Growing interest in understanding microbiota dynamics has motivated the development of different strategies to model microbiota time series data. However, all of them must tackle the fact that the available data are high-dimensional, posing strong statistical and computational challenges. In order to address this challenge, we propose a Dirichlet autoregressive model with time-varying parameters, which can be directly adapted to explain the effect of groups of taxa, thus reducing the number of parameters estimated by maximum likelihood. A strategy has been implemented which speeds up this estimation. The usefulness of the proposed model is illustrated by application to a case study.

Dairy product consumption and risk of type 2 diabetes in an elderly Spanish Mediterranean population at high cardiovascular risk.

2015

PURPOSE The possible effects of dairy consumption on diabetes prevention remain controversial. The aim of this study was to investigate the association between the dairy consumption and type 2 diabetes (T2D) risk in an elderly Mediterranean population at high cardiovascular risk. METHODS: We prospectively followed 3,454 non-diabetic individuals from the PREDIMED study. Dairy consumption was assessed at baseline and yearly using food frequency questionnaires and categorized into total, low-fat, whole-fat, and subgroups: milk, yogurt, cheeses, fermented dairy, concentrated full fat, and processed dairy. Hazard ratios (HRs) were calculated using Cox proportional hazards regression models. RESU…