4,901 research outputs found
Neural regulation of cardiovascular response to exercise: role of central command and peripheral afferents
During dynamic exercise, mechanisms controlling the cardiovascular apparatus operate to provide adequate oxygen to fulfill metabolic demand of exercising muscles and to guarantee metabolic end-products washout. Moreover, arterial blood pressure is regulated to maintain adequate perfusion of the vital organs without excessive pressure variations. The autonomic nervous system adjustments are characterized by a parasympathetic withdrawal and a sympathetic activation. In this review, we briefly summarize neural reflexes operating during dynamic exercise. The main focus of the present review will be on the central command, the arterial baroreflex and chemoreflex, and the exercise pressure reflex. The regulation and integration of these reflexes operating during dynamic exercise and their possible role in the pathophysiology of some cardiovascular diseases are also discusse
Specific cancer rates may differ in patients with hereditary haemorrhagic telangiectasia compared to controls.
BACKGROUND: Hereditary haemorrhagic telangiectasia (HHT) is inherited as an autosomal dominant trait, affects ~1 in 5,000, and causes multi-systemic vascular lesions and life-limiting complications. Life expectancy is surprisingly good, particularly for patients over 60ys. We hypothesised that individuals with HHT may be protected against life-limiting cancers. METHODS: To compare specific cancer rates in HHT patients and controls, we developed a questionnaire capturing data on multiple relatives per respondent, powered to detect differences in the four most common solid non skin cancers (breast, colorectal, lung and prostate), each associated with significant mortality. Blinded to cancer responses, reports of HHT-specific features allowed assignment of participants and relatives as HHT-subjects, unknowns, or controls. Logistic and quadratic regressions were used to compare rates of specific cancer types between HHT subjects and controls. RESULTS: 1,307 participants completed the questionnaire including 1,007 HHT-subjects and 142 controls. The rigorous HHT diagnostic algorithm meant that 158 (12%) completed datasets were not assignable either to HHT or control status. For cancers predominantly recognised as primary cancers, the rates in the controls generally matched age-standardised rates for the general population. HHT subjects recruited through the survey had similar demographics to controls, although the HHT group reported a significantly greater smoking habit. Combining data of participants and uniquely-reported relatives resulted in an HHT-arm of 2,161 (58% female), and control-arm of 2,817 (52% female), with median ages of 66ys [IQR 53–77] and 77ys [IQR 65–82] respectively. In both crude and age-adjusted regression, lung cancers were significantly less frequent in the HHT arm than controls (age-adjusted odds ratio 0.48 [0.30, 0.70], p = 0.0012). Breast cancer prevalence was higher in HHT than controls (age-adjusted OR 1.52 [1.07, 2.14], p = 0.018). Overall, prostate and colorectal cancer rates were equivalent, but the pattern of colorectal cancer was modified, with a higher prevalence in younger HHT patients than controls. CONCLUSIONS: These preliminary survey data suggest clinically significant differences in the rates of lung, breast and colorectal cancer in HHT patients compared to controls. For rare diseases in which longitudinal studies take decades to recruit equivalent datasets, this type of methodology provides a good first-step method for data collection
Surgical Treatment of Rotator Cuff Tears After 65 Years of Age: A Systematic Review
INTRODUCTION:
The objective of this study was to analyze current evidence regarding surgical management of rotator cuff tears in patients of 65 years of age and above. Our hypothesis was that surgical repair of rotator cuff tears, in patients older than 65 years, conveys good outcome scores. We have not found a similar systematic review in current literature.
MATERIAL AND METHODS:
Medline®, PubMed, Scopus, and the Cochrane Register of Controlled Trials were searched from January 1999 unto December 2015 for studies, regardless of language, including the words 'rotator cuff' and '65 years' or '70 years'. Inclusion criteria were studies (level I to IV) that reported clinical outcomes in patients older than 65 years, having undertaken surgical repair of a symptomatic rotator cuff tears. Arthroscopic, mini open and open techniques were included. Exclusion criteria were: studies with patients younger than 65 years, studies that did not use validated outcome evaluation scores as primary assessment tools and those with follow up under one year. This work followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses - PRISMA guidelines. Data abstracted included patient demographics, tear pattern, surgical procedures, clinical and repair results. Outcome scores were converted to percentages, allowing comparison of data between studies.
RESULTS:
After deep analysis, 14 studies met the inclusion criteria: 11 level IV studies, 1 level III study and 2 level II studies. Seven studies found statistically significant outcome improvements between pre and postoperative evaluations. All studies reported good or excellent surgical outcomes.
DISCUSSION:
Better results would probably be achieved if all studies had rigorous and homogeneous patient selection criteria, but the fact is, that even though this was not the case, the clinical scores remained favorable, and with statistically significant outcome improvement in all studies with prospectively collected data.
CONCLUSION:
Based on current literature, rotator cuff repair in patients older than 65 years imparts favorable improvement in clinical outcome scores and overall patient satisfaction.info:eu-repo/semantics/publishedVersio
Abordagem ClÃnica e Terapêutica de Doentes Internados por COVID-19: Uma Coorte Pediátrica em Portugal
Introduction: Coronavirus disease 2019, or COVID-19, in children is usually a mild disease, but severe illness has been reported. Currently, the therapy benefits of antiviral experimental drugs are still uncertain. The main aim of this study is to describe the experience of a level III hospital regarding therapeutic management of hospitalized children with COVID-19 and to characterize clinical features and evolution.
Material and methods: This is a descriptive study of patients with COVID-19 in a level III pediatric hospital in Portugal between March and June 2020. Experimental drugs were administered according to the best scientific evidence at the time as 'off-label use'.
Results: Among 200 children with SARS-CoV-2 infection, 37 were admitted due to COVID-19. Median age was one year (23 days - 18 years), 43% had comorbidities and 20/37 (54%) received antiviral therapy. Hydroxychloroquine was administered in 13 patients, in monotherapy or combined with lopinavir/ritonavir or azithromycin. Lopinavir/ritonavir was administered in eight patients and three children were treated with remdesivir. The patients who were treated had pneumonia (14), multisystem inflammatory syndrome in children (2), sepsis (2), myocarditis (1), acute respiratory distress syndrome (1), and mild illness with comorbidities (3). Other therapies included methylprednisolone and immunoglobulin (3), enoxaparin (2), antibiotics (16), oxygen (7), corticosteroids, and other inhaled therapy (16).
Discussion: Several treatment approaches have been proposed for severe COVID-19, even though none of them had been proven effective or approved for small children. Currently, remdesivir is approved for children aged above 12 years-old. Although 54% of our patients were treated with antivirals, it is important to understand that the favorable clinical evolution could be related with the natural course of the disease.
Conclusion: A significant proportion of our population presented severe and critical disease, was hospitalized and received treatment according to the most recent data, although most patients had mild disease. COVID-19 treatment in children is a clinical challenge and clinical trials are urgently needed.info:eu-repo/semantics/publishedVersio
Amphibians on the hotspot: Molecular biology and conservation in the South American Atlantic Rainforest
Amphibians are the focus of a recent debate and public attention owing to the global decline in their populations worldwide. Amphibians are one of the most threatened and poorly known groups of vertebrates in several geographic areas, even though they play a central role in their own ecosystems. At different levels, amphibians make their contribution to proper ecosystem functioning. They act as regulators of the food web and nutrient cycling, and they also provide several valuable ecosystem services, e.g., as a food source and as animal models for lab research. In this sense, it seems clear that the maintenance of amphibian diversity should be one of the major goals for the several countries where their population decline is observed. However, we are still struggling with the very first step of this process, i.e., the correct identification of the amphibian species diversity. Over the past few decades, research on molecular identification of amphibians using DNA barcoding has encountered some difficulties related to high variability in the mitochondrial genome of amphibians, and a research gap is noticeable in the literature. We herein evaluated both COI and 16S rRNA mitochondrial genes for the molecular identification of frogs and tadpoles in a large fragment of the South American Atlantic Rainforest in Rio de Janeiro, Brazil. Our results suggest that both COI and 16S rRNA are informative markers for the molecular identification of the amphibian specimens with all specimens unambiguously identified at the species level. We also made publicly available 12 new sequences of Atlantic Rainforest amphibian species for the first time, and we discussed some conservation issues related to amphibians within the Atlantic Rainforest domains in the state of Rio de Janeiro, Brazil.The authors benefited from grants provided to CFDR (304791/2010-5; 470265/2010- 8 and 302974/2015-6) from Conselho Nacional do Desenvolvimento Cientifico e Tecnologico (CNPq) and through "Cientistas do Nosso Estado" Program from FAPERJ to CFDR (process No. E-26/ 102.765.2012 E-26/202.920.2015). We would like to thank C. Haddad (Universidade Estadual Paulista) and M. L. Lyra (Universidade Estadual Paulista) for some of the specimens and the primers used in the present manuscript and L. A. Fusinatto, who kindly revised the manuscript offering helpful suggestions. FP was supported by the Portuguese Foundation for Science and Technology (FCT) [IF/01356/2012] and Northern Regional Operational Programme (NORTE2020) through the European Regional Development Fund (ERDF) [MARINFO NORTE-01-0145-FEDER- 000031]. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript
Being Deaf in Mainstream Schools: The Effect of a Hearing Loss in Children’s Playground Behaviors
Naturalistic playground observations are a rich source of information when studying the social interactions of preschool children. On the playground, children can interact with their peers, explore different places and activities, and engage in different types of play. For deaf and hard of hearing (DHH) children, interactions at a playground can be more difficult because of the large number of auditory stimuli surrounding them. Constraints in the access to the social world on the playground might hamper DHH children's interactions with their typically hearing (TH) peers, activities, and play. This pilot study aimed to examine the playground behaviors of preschool DHH children across three aspects: social levels, type of activities, and play choices. For this purpose, 12 preschool DHH children were observed during recess time, and their behaviors were coded and compared to their 85 TH peers. The preliminary findings indicate that DHH children spend less time in social interactions compared to their TH peers and that they still face difficulties when socially engaging with their TH peers. These findings suggest that interventions should focus on three aspects: the physical environment awareness of TH peers about communicating with DHH children, and the use of exercise play to facilitate social interactions between DHH children and their TH peers.info:eu-repo/semantics/publishedVersio
A switch from high-fat to normal diet does not restore sperm quality but prevents metabolic syndrome
In recent decades, the prevalence of metabolic diseases has concomitantly increased with a decline on fertility rates and sperm quality. High-fat diets (HFD) are seldom considered part of the problem, but the molecular mechanisms underlying its effects on male fertility remain poorly understood. Herein we postulated that HFD alter sperm quality. We evaluated the effects of switching from a HFD to a normal diet in early adulthood on metabolic disease onset, testicular metabolism and sperm quality. Thirty-six male C57BL6/J mice were divided in: a control group fed with standard chow; a group fed with HFD for 200 days; and a group fed with HFD for 60 days and then with standard chow (HFDt). Biometric data and whole-body metabolism were assessed. Epididymal sperm was studied for concentration, motility, viability and morphology. 1H-NMR metabolomics approach was performed on testicular extracts to trace the metabolic changes. Diet switch reduced body weight and fat mass, preventing metabolic syndrome onset. However, sperm viability, motility and morphology were deteriorated by HFD consumption and not restored by diet switch. HFD induced irreversible changes in pyruvate and glutamate metabolism, ethanol degradation and ammonia recycling in testis. Furthermore, HFDt changed purine and cysteine metabolism, urea cycle, and glutathione content. Overall, HFD caused irreversible changes in testicular metabolism even after switching to normal diet. HFD feeding until early adulthood decreases sperm quality, which cannot be restored by diet switch or weight loss, even when development of metabolic syndrome is avoided
PUK7 IMMUNOSUPPRESSANT THERAPY PATTERNS AND ITS COSTS IN POST KIDNEY TRANSPLANT PATIENTS IN THE NATIONAL TRANSPLANT PROGRAM IN BRAZIL
Hyperoside Supplementation in Preservation Media Surpasses Vitamin C Protection Against Oxidative Stress-Induced Damages in Human Spermatozoa
Background/Aims: Oxidative Stress (OS) is reported as one of the main causes of male infertility. Infertile couples often resort to assisted reproductive technology (ART) to achieve parenthood. However, preparation for ART protocols increases the exposer of gametes to OS. Thus, it is crucial to find suitable preservation media that can counteract the OS-induced damages in spermatozoa. In this work, we tested and compared the efficiency of vitamin C (VC) and hyperoside (HYP) as potential antioxidant supplements for sperm preservation media. Methods: We evaluated the cytotoxicity of HYP (0, 5, 50, 100, and 500 µM) in spermatozoa. After incubation of sperm cells with VC (600 µM) and HYP (100 and 500 µM), in the presence and absence of H2O2 (300 µM), the following parameters were assessed: total sperm motility and vitality, OS biomarkers expression, total antioxidant capacity (TAC) of the media, percentage of DNA fragmentation, mitochondrial membrane potential (MMP), and metabolite quantification of the media by proton nuclear magnetic resonance (1H-NMR). Results: The supplementation with VC (600 µM) and HYP (100 and 500 µM) did not induce any deleterious effects to the physiology and metabolism of the spermatozoa, after 1-hour of treatment. In the presence of H2O2 (300 µM), both VC and HYP were able to prevent some of the deleterious effects of H2O2 in sperm, which were represented by an increase in sperm motility, a decrease in DNA fragmentation, and a decreasing trend in lipid peroxidation levels. However, these antioxidants were not able to prevent the decrease of MMP associated with H2O2 treatment, nor were able to prevent the conversion of pyruvate into acetate (a reaction promoted by H2O2). Conclusion: The supplementation of sperm preservation media with VC and HYP could be beneficial for the preservation of sperm physiology. From the antioxidant conditions tested, the supplementation of media with HYP (100 µM) demonstrated the best results regarding sperm preservation, evidencing the higher antioxidant capacity of HYP compared to VC. Nevertheless, none of the antioxidants used was able to prevent the metabolic alterations promoted by H2O2 in spermatozoa.This work was supported by Fundação para a Ciência e a Tecnologia - FCT to Sara C. Pereira (2021.05487.BD); David F. Carrageta (SFRH/BD/136779/2018); Marco G. Alves (IFCT2015 and PTDC/MEC-AND/28691/2017); LAQV-REQUIMTE (UIDB/50006/2020); UMIB (UIDB/00215/2020, and UIDP/00215/2020); ITR - Laboratory for Integrative and Translational Research in Population Health (LA/P/0064/2020). Pedro F. Oliveira was funded by national funds through FCT – Fundação para a Ciência e a Tecnologia, I.P., under the Scientific Employment Stimulus - Institutional Call - reference CEECINST/00026/2018
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