1,721,088 research outputs found
Low expression of human beta-defensin 1 in duodenum of celiac patients is partially restored by a gluten-free diet.
No full textBACKGROUND: Human beta-defensins (hBDs) are small cationic, widely expressed proteins involved in innate immunity that exert strong bactericidal activity toward various pathogens. However, the role of hBDs in various diseases to which bacterial infection add severity, as it is in celiac disease (CD), is not yet clear. We analyzed the expression of the hBD1, hBD2, hBD3 and hBD4 genes in patients with CD during the active phase and after remission following a gluten-free diet to determine their role in development and relapse of CD.
METHODS: We studied 21 unrelated adults with CD (confirmed by anti-thyroglobulin antibodies and intestinal biopsy); 14 were evaluated at diagnosis, before diet modification, and seven after 2 years of a gluten-free diet. Thirty-six unrelated adults served as controls. We analyzed the mRNA expression of hBD1, 2, 3 and 4 on biopsy samples of duodenum obtained from all patients during endoscopy for diagnostic purposes. We used real-time polymerase chain reaction with TaqMan probes and obtained gene expression data using the delta-Ct method.
RESULTS: hBD1 mRNA was significantly lower in patients with active CD compared with patients on diet modification, whereas the mRNA levels of the other three defensins did not differ significantly between the two subgroups. Interestingly, the gluten-free diet restored only partially hBD1 expression as compared to a normal group of celiac-free subjects.
CONCLUSIONS: Our data reinforce the evidence that hBD1 expression is greatly reduced in the duodenum of patients with active CD. It also strengthens the concept that reduced activity of immune peptides may predispose individuals to bacterial proliferation that contributes to the pathogenesis of C
ACE and AGTR1 polymorphisms in elite rhythmic gymnastics
No full textIn the angiotensin-converting enzyme (ACE) gene, Alu deletion, in intron 16, is associated with higher concentrations of ACE serum activity and this may be associated with elite sprint and power performance. The Alu insertion is associated with lower ACE levels and this could lead to endurance performance. Moreover, recent studies have identified a single-nucleotide polymorphism of the angiotensin type 1 receptor gene AGTR1, which seems to be related to ACE activity. The aim of this study was to examine the involvement of the ACE and the AGTR1 gene polymorphisms in 28 Italian elite rhythmic gymnasts (age range 21 ± 7.6 years), and compare them to 23 middle level rhythmic gymnasts (age range 17 ± 10.9 years). The ACE D allele was significantly more frequent in elite athletes than in the control population (χ(2)=4.07, p=0.04). Comparisons between the middle level and elite athletes revealed significant differences (p<0.0001) for the ACE DD genotype (OR=6.48, 95% confidence interval=1.48-28.34), which was more frequent in elite athletes. There were no significant differences in the AGTR1 A/C genotype or allele distributions between the middle level and elite athletes. In conclusion, the ACE D allele genotype could be a contributing factor to high-performance rhythmic gymnastics that should be considered in athlete development and could help to identify which skills should be trained for talent promotion
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Genetic risk factors and candidate biomarkers for Alzheimer’s disease
No full textAlzheimer's disease is a multifactorial and
progressive neurodegenerative disease, extremely diffused
and with an increasing prevalence worldwide. There is an
urgent need for biomarkers to diagnose AD early in its
course. Furthermore, accurate biomarkers would be able to
determine the clinical efficacy of novel neuroprotective
strategies. Although the heritability of late-onset AD is
high, our knowledge of the underlying putative
susceptibility genes remains incomplete and the only
unequivocally established late-onset AD gene is APOE.
Nevertheless a number of susceptibility loci seems to
influence the pathogenesis of AD, and variations in
numerous genes have been considered to be important in
the risk for AD. Many advances have been made in
identifying biochemical indices of brain dysfunction,
measured in body fluids such as cerebrospinal fluid and
plasma, with different methodological approaches.
Although these biomarkers are promising, none of them
can predict AD with 100% confidence to date. This review
will elaborate on the available selection of genetic and
biochemical biomarkers for AD, with a particular reference
to those linked to inflammation and oxidative stress
Association Between Beta-Carotene Supplementation and Mortality: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Full text linkBACKGROUND: Aging is a phenomenon universally involving all organisms, genetically determined, and epigenetically influenced by the environment. Numerous observational studies have shown the positive impact of non-pharmacological approaches started in younger age on chronic conditions affecting the elderly health and survival. This meta-analysis aimed to investigate the effect of beta-carotene on the total and cause-specific mortality as reported by randomized controlled trials (RCTs). METHODS: We searched Medline, Scopus, Web of Science, and CENTRAL Cochrane from inception to September 2021. Studies were eligible if enrolled adults with any health condition, compared beta-carotene supplements at any dose with placebo or no intervention, provided information on deaths from any cause, and were RCTs, in English. The risk of bias was assessed by the Cochrane risk of bias tool and the GRADE. Risk ratios and their 95% confidence intervals were used and a P-value less than 0.05 was considered statistically significant. RESULTS: Among 3,942 articles searched, 44 articles on 31 RCTs, which included 216,734 total subjects, 108,622 in beta-carotene supplement groups, and 108,112 in the placebo or no-intervention groups, were involved in the final analyses. In a random-effects meta-analysis of all 31 trials, beta-carotene supplements were found to have no preventive effect on mortality (risk ratio 1.02, 95% confidence interval 0.98–1.05, I(2) = 42%). Further, the analysis showed no preventive effect on cancer, cardiovascular, cerebrovascular, and other mortality causes. Instead, beta-carotene supplementation significantly increased the risk of lung cancer mortality (RR 1.14, 95% CI 1.02, 1.27, I(2) = 3%) but decreased the risk of human immunodeficiency virus-related mortality (RR 0.55, 95% CI 0.33, 0.92, I(2) = 0). CONCLUSION: More studies should be performed to better define the role of beta-carotene on survival, to confirm or deny our results. Therefore, the possible beneficial or harmful effects of the beta-carotene supplementation on mortality must not be overstated. SYSTEMATIC REVIEW REGISTRATION: [https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=259354], identifier [CRD42021259354]
Astaxanthin as a Modulator of Nrf2, NF-κB, and Their Crosstalk: Molecular Mechanisms and Possible Clinical Applications
Full text linkAstaxanthin (AST) is a dietary xanthophyll predominantly found in marine organisms and seafood. Due to its unique molecular features, AST has an excellent antioxidant activity with a wide range of applications in the nutraceutical and pharmaceutical industries. In the past decade, mounting evidence has suggested a protective role for AST against a wide range of diseases where oxidative stress and inflammation participate in a self-perpetuating cycle. Here, we review the underlying molecular mechanisms by which AST regulates two relevant redox-sensitive transcription factors, such as nuclear factor erythroid 2-related factor 2 (Nrf2) and nuclear factor κB (NF-κB). Nrf2 is a cellular sensor of electrophilic stress that coordinates the expression of a battery of defensive genes encoding antioxidant proteins and detoxifying enzymes. Likewise, NF-κB acts as a mediator of cellular stress and induces the expression of various pro-inflammatory genes, including those encoding cytokines, chemokines, and adhesion molecules. The effects of AST on the crosstalk between these transcription factors have also been discussed. Besides this, we summarize the current clinical studies elucidating how AST may alleviate the etiopathogenesis of oxidative stress and inflammation
The ART of Thromboprophylaxis in the Prevention of Gestational Venous Thromboembolism
No full textAssisted reproductive techniques (ART) allow infertile couples to conceive. Use of hormones to obtain a controlled ovarian stimulation and an adequate growth of the endometrium preparatory for embryo implantation are not riskless. Among others, thrombotic events can occur during the ovulation induction or pregnancy following ART. As the number of women approaching ART to conceive is steadily increasing, the issue of thrombotic risk in this setting is relevant. Data on the weight of each risk factor and on potential benefit of thromboprophylaxis are largely lacking. In this review, we discuss risk of venous thromboembolism during pregnancy following ART, with a focus on general (i.e.: age, body mass index, thrombophilia, bed rest, transfusions) and ART-specific (i.e., polycystic ovarian syndrome, ovarian hyperstimulation syndrome) risk factors. We also attempt to provide some suggestions to guide clinical practice, based on available data and studies performed outside ART
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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