865 resultados para Body, human


Relevância:

30.00% 30.00%

Publicador:

Resumo:

Tumour necrosis factor (TNF)alpha is implicated in the relationship between obesity and insulin resistance/ type 2 diabetes. In an effort to understand this association better we (i) profiled gene expression patterns of TNF, TNFR1 and TNFR2 and (ii) investigated the effects of TNF on glucose uptake in isolated adipocytes and adipose tissue explants from omental and subcutaneous depots from lean, overweight and obese individuals. TNF expression correlated with expression of TNFR2, but not TNFR1, and TNF and TNFR2 expression increased in obesity. TNFR1 expression was higher in omental than in subcutaneous adipocytes. Expression levels of TNF or either receptor did not differ between adipocytes from individuals with central and peripheral obesity. TNF only suppressed glucose uptake in insulin-stimulated subcutaneous tissue and this suppression was only observed in tissue from lean subjects. These data support a relationship between the TNF system and body mass index (BMI), but not fat distribution, and suggest depot specificity of the TNF effect on glucose uptake. Furthermore, adipose tissue from obese subjects already appears insulin 'resistant' and this may be a result of the increased TNF levels.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Human polybrominated diphenyl ether (PBDE) exposure occurs through a range of pathways including: ingestion of dust including hand-to-mouth contact; inhalation (air/particulate matter); and ingestion via food including the unique nutrition sources of human milk and placental transfer. While inhalation has been deemed a minor source of exposure, ingestion of food and dust make greater contributions to overall PBDE body burden with intake via dust reported to be much higher in infants than in adults. PBDEs have been detected in samples of human milk, blood serum, cord blood, and adipose tissue worldwide. Concentrations have been found to be highest in populations from North America, followed by Australia, Europe, and Asia. While factors such as gender and parity may not affect concentrations, occupational exposure and age (infants and children) are associated with higher PBDE concentrations. In contrast to “traditional” persistent organic pollutants, there is an inverse relationship between PBDE body burden and age. Predicted body burden calculated using available information on intake and elimination rates of BFRs appears to underestimate measured human body burden data obtained through analysis of BFRs in blood or human milk. This may be due to unknown exposure or inaccurate elimination data. Further exposure studies should focus on younger age groups and an investigation of human PBDE half-lives.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Since World War I, explosions have accounted for over 70% of all injuries in conflict. With the development of improved personnel protection of the torso, improved medical care and faster aeromedical evacuation, casualties are surviving with more severe injuries to the extremities. Understanding the processes involved in the transfer of blast-induced shock waves through biological tissues is essential for supporting efforts aimed at mitigating and treating blast injury. Given the inherent heterogeneities in the human body, we argue that studying these processes demands a highly integrated approach requiring expertise in shock physics, biomechanics and fundamental biological processes. This multidisciplinary systems approach enables one to develop the experimental framework for investigating the material properties of human tissues that are subjected to high compression waves in blast conditions and the fundamental cellular processes altered by this type of stimuli. Ultimately, we hope to use the information gained from these studies in translational research aimed at developing improved protection for those at risk and improved clinical outcomes for those who have been injured from a blast wave.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Preserving the integrity of the skin's outermost layer (the epidermis) is vital for humans to thrive in hostile surroundings. Covering the entire body, the epidermis forms a thin but impenetrable cellular cordon that repels external assaults and blocks escape of water and electrolytes from within. This structure exists in a perpetual state of regeneration where the production of new cellular subunits at the base of the epidermis is offset by the release of terminally differentiated corneocytes from the surface. It is becoming increasingly clear that proteases hold vital roles in assembling and maintaining the epidermal barrier. More than 30 proteases are expressed by keratinocytes or infiltrating immune cells and the activity of each must be maintained within narrow limits and confined to the correct time and place. Accordingly, over- or under-exertion of proteolytic activity is a common factor in a multitude of skin disorders that range in severity from relatively mild to life-threatening. This review explores the current state of knowledge on the involvement of proteases in skin diseases and the latest findings from proteomic and transcriptomic studies focused on uncovering novel (patho)physiological roles for these enzymes.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

One of the core values to be applied by a body reviewing the ethics of human research is justice. The inclusion of justice as a requirement in the ethical review of human research is relatively recent and its utility had been largely unexamined until debates arose about the conduct of international biomedical research in the late 1990s. The subsequent amendment of authoritative documents in ways that appeared to shift the meaning of conceptions of justice generated a deal of controversy. Another difficulty has been that both the theory and the substance of justice that are applied by researchers or reviewers can be frequently seen to be subjective. Both the concept of justice – whether distributive or commutative - and what counts as a just distribution or exchange – are given different weight and meanings by different people. In this paper, the origins and more recent debates about the requirement to consider justice as a criterion in the ethical review of human research are traced, relevant conceptions of justice are distinguished and the manner in which they can be applied meaningfully in the ethical review all human research is identified. The way that these concepts are articulated in, and the intent and function of, specific paragraphs of the National Statement on Ethical Conduct in Human Research (NHMRC, ARC, UA, 2007) (National Statement) is explained. The National Statement identifies a number of issues that should be considered when a human research ethics committee is reviewing the justice aspects of an application. It also provides guidance to researchers as to how they can show that there is a fair distribution of burdens and benefits in the participant experience and the research outcomes. It also provides practical guidance to researchers on how to think through issues of justice so that they can demonstrate that the design of their research projects meets this ethical requirement is also provided

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This issue of the Journal of Law and Medicine seeks to explore the law's relationship with the human body within a broad context of social, cultural and technological considerations. It does this both in terms of the ways in which the law constitutes the body (for example, by labelling it as property or otherwise), and in terms of the legal rules which regulate rights to bodies and body parts.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Mammographic density (MD) is the area of breast tissue that appears radiologically white on mammography. Although high MD is a strong risk factor for breast cancer, independent of BRCA1/2 mutation status, the molecular basis of high MD and its associated breast cancer risk is poorly understood. MD studies will benefit from an animal model, where hormonal, gene and drug perturbations on MD can be measured in a preclinical context. High and low MD tissues were selectively sampled by stereotactic biopsy from operative specimens of high-risk women undergoing prophylactic mastectomy. The high and low MD tissues were transferred into separate vascularised biochambers in the groins of SCID mice. Chamber material was harvested after 6 weeks for histological analyses and immunohistochemistry for cytokeratins, vimentin and a human-specific mitochondrial antigen. Within-individual analysis was performed in replicate mice, eliminating confounding by age, body mass index and process-related factors, and comparisons were made to the parental human tissue. Maintenance of differential MD post-propagation was assessed radiographically. Immunohistochemical staining confirmed the preservation of human glandular and stromal components in the murine biochambers, with maintenance of radiographic MD differential. Propagated high MD regions had higher stromal (p = 0.0002) and lower adipose (p = 0.0006) composition, reflecting the findings in the original human breast tissue, although glands appeared small and non-complex in both high and low MD groups. No significant differences were observed in glandular area (p = 0.4) or count (p = 0.4) between high and low MD biochamber tissues. Human mammary glandular and stromal tissues were viably maintained in murine biochambers, with preservation of differential radiographic density and histological features. Our study provides a murine model for future studies into the biomolecular basis of MD as a risk factor for breast cancer.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The experiences and constructs of time, space and bodies saturate human discourse—naturally enough, since they are fundamental to existence—yet there has long been a tendency for the terms to be approached somewhat independently, belying the depth of their interconnections. It was a desire to address that apparent shortcoming that inspired this book, and the interdisciplinary meetings from which it was born, the 1st Global Conferences on ‘Time, Space and the Body’ and ‘Body Horror’ held in Sydney in February 2013. Following the lively, often provocative, exchange of ideas throughout those meetings, the writing here crosses conventional boundaries inhabiting everyday life and liminal experiences, across cultures, life circumstances, and bodily states. Through numerous theoretical frameworks and with reference to a variety of media, the authors problematize or deconstruct commonplace assumptions to reveal challenging new perspectives on the diverse cultures and communities which make our world. If there is an overarching theme of this collection it is diversity itself. The writers here come from numerous academic fields, but a good number of them also draw on first-hand cultural production in the arts: photography, sculpture and fine art instillation, for example. Of course, however laudable it might be, there is a potential problem in such diversity: does it produce fruitful dialogue moving toward creative, workable syntheses or simply a cacophony of competing, incomprehensible, barely comprehending voices? To a large degree this depends upon the intellectual, existential ambitions as well as the old-fashioned goodnatured tolerance of both writers and readers. But we hope three unifying characteristics are discernable in the following chapters viewed as a whole: firstly, a genuine concern for the world humans inhabit and the communities they form as bodies in space and time; secondly, an emphasis upon the experience of the human subject, exemplified perhaps by the number of chapters drawing on phenomenology; thirdly, an adventurous, explorative impulse associated with an underlying sense that being, since it is inseparable from the body’s temporality, is always becoming, and here the presence of poststructuralist influences is unmistakable, often explicit. Our challenge as editors has been to present the enormous variety of subjects and views in a way that would render the book coherent and at the same time encourage readers to make explorations themselves into realms they might usually consider beyond their field of interest. To that end we have divided the book into six sections around loosely defined themes, each offering different angles on how time and/or space unfold in and around bodies.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Rationale: Chronic lung disease characterized by loss of lung tissue,inflammation, and fibrosis represents a major global health burden. Cellular therapies that could restore pneumocytes and reduce inflammation and fibrosis would be a major advance in management. Objectives: To determine whether human amnion epithelial cells (hAECs), isolated from term placenta and having stem cell–like and antiinflammatory properties, could adopt an alveolar epithelial phenotype and repair a murine model of bleomycin-induced lung injury. Methods: Primary hAECs were cultured in small airway growth medium to determine whether the cells could adopt an alveolar epithelial phenotype. Undifferentiated primary hAECs were also injected parenterally into SCID mice after bleomycin-induced lung injury and analyzed for production of surfactant protein (SP)-A, SP-B, SP-C, and SP-D. Mouse lungs were also analyzed for inflammation and collagen deposition. Measurements and Main Results: hAECs grown in small airway growth medium developed an alveolar epithelial phenotype with lamellar body formation, production of SPs A–D, and SP-D secretion. Although hAECs injected into mice lacked SPs, hAECs recovered from mouse lungs 2 weeks posttransplantation produced SPs. hAECs remained engrafted over the 4-week test period. hAEC administration reduced inflammation in association with decreased monocyte chemoattractant protein-1, tumor necrosis factor-a, IL-1 and -6, and profibrotic transforming growth factor-b in mouse lungs. In addition,lung collagen content was significantly reduced by hAEC treatment as a possible consequence of increased degradation by matrix metalloproteinase-2 and down-regulation of the tissue inhibitors f matrix metalloproteinase-1 and 2. Conclusions: hAECs offer promise as a cellular therapy for alveolar restitution and to reduce lung inflammation and fibrosis.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Objective. To estimate the burden of disease attributable to excess body weight using the body mass index (BMI), by age and sex, in South Africa in 2000. Design. World Health Organization comparative risk assessment (CRA) methodology was followed. Re-analysis of the 1998 South Africa Demographic and Health Survey data provided mean BMI estimates by age and sex. Populationattributable fractions were calculated and applied to revised burden of disease estimates. Monte Carlo simulation-modelling techniques were used for the uncertainty analysis. Setting. South Africa. Subjects. Adults 30 years of age. Outcome measures. Deaths and disability-adjusted life years (DALYs) from ischaemic heart disease, ischaemic stroke, hypertensive disease, osteoarthritis, type 2 diabetes mellitus, and selected cancers. Results. Overall, 87% of type 2 diabetes, 68% of hypertensive disease, 61% of endometrial cancer, 45% of ischaemic stroke, 38% of ischaemic heart disease, 31% of kidney cancer, 24% of osteoarthritis, 17% of colon cancer, and 13% of postmenopausal breast cancer were attributable to a BMI 21 kg/m2. Excess body weight is estimated to have caused 36 504 deaths (95% uncertainty interval 31 018 - 38 637) or 7% (95% uncertainty interval 6.0 - 7.4%) of all deaths in 2000, and 462 338 DALYs (95% uncertainty interval 396 512 - 478 847) or 2.9% of all DALYs (95% uncertainty interval 2.4 - 3.0%). The burden in females was approximately double that in males. Conclusions. This study shows the importance of recognising excess body weight as a major risk to health, particularly among females, highlighting the need to develop, implement and evaluate comprehensive interventions to achieve lasting change in the determinants and impact of excess body weight.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Accurate modelling of automotive occupant posture is strongly related to the mechanical interaction between human body soft tissue and flexible seat components. This paper presents a finite-element study simulating the deflection of seat cushion foam and supportive seat structures, as well as human buttock and thigh soft tissue when seated. The thigh-buttock surface shell model was based on 95th percentile male subject scan data and made of two layers, covering thin to moderate thigh and buttock proportions. To replicate the effects of skin and fat, the neoprene rubber layer was modelled as a hyperelastic material with viscoelastic behaviour. The analytical seat model is based on a Ford production seat. The result of the finite-element indentation simulation is compared to a previous simulation of an indentation with a hard shell human model of equal geometry, and to the physical indentation result. We conclude that SAE composite buttock form and human-seat indentation of a suspended seat cushion can be validly simulated.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

This study arose out of the 2002 Review of the PCB Management Plan by the Scheduled Waste Management Network (SWMN) and the National Advisory Body (NAB). The Review indicated it would be beneficial to obtain some data on the levels of organochlorine pesticides (OCPs) in the Australian population. In 2002, the Environment Protection and Heritage Standing Committee (EPHSC) agreed and noted that the Australian Government Department of the Environment and Heritage (DEH) would commission a study using the same samples from the National Dioxins Program (NDP) breast milk study collected in 2002- 03. The study, however, was also broadened to include polybrominated diphenyl ethers (PBDEs).

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The first consideration of any Australian Human Research Ethics Committee should be to satisfy itself that the project before them is worth undertaking. If the project does not add to the body of knowledge, if it does not improve social welfare or individual wellbeing then the use of human participants, their tissue or their data must be questioned. Sometimes, however, committees are criticised for appearing to adopt the role of scientific review committees. The intent of this paper is to provide researchers with an understanding of the ethical importance of demonstrating the merit of their research project and to help them develop protocols that show ethics committees that adequate attention has been paid to this central tenet in dealing ethically with human research participants. Any person proposing human research must be prepared to show that it is worthwhile. This paper will clarify the relationship between research merit and integrity, research ethics and the responsibilities of human research ethics committees.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Background The genetic mutation resulting in osteogenesis imperfecta (OI) type V was recently characterised as a single point mutation (c.-14C > T) in the 5' untranslated region (UTR) of IFITM5, a gene encoding a transmembrane protein with expression restricted to skeletal tissue. This mutation creates an alternative start codon and has been shown in a eukaryotic cell line to result in a longer variant of IFITM5, but its expression has not previously been demonstrated in bone from a patient with OI type V. Methods Sanger sequencing of the IFITM5 5' UTR was performed in our cohort of subjects with a clinical diagnosis of OI type V. Clinical data was collated from referring clinicians. RNA was extracted from a bone sample from one patient and Sanger sequenced to determine expression of wild-type and mutant IFITM5. Results: All nine subjects with OI type V were heterozygous for the c.-14C > T IFITM5 mutation. Clinically, there was heterogeneity in phenotype, particularly in the manifestation of bone fragility amongst subjects. Both wild-type and mutant IFITM5 mRNA transcripts were present in bone. Conclusions The c.-14C > T IFITM5 mutation does not result in an RNA-null allele but is expressed in bone. Individuals with identical mutations in IFITM5 have highly variable phenotypic expression, even within the same family.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Humans and microbes have developed a symbiotic relationship over time, and alterations in this symbiotic relationship have been linked to several immune mediated diseases such as inflammatory bowel disease, type 1 diabetes and spondyloarthropathies. Improvements in sequencing technologies, coupled with a renaissance in 16S rRNA gene based community profiling, have enabled the characterization of microbiomes throughout the body including the gut. Improved characterization and understanding of the human gut microbiome means the gut flora is progressively being explored as a target for novel therapies including probiotics and faecal microbiota transplants. These innovative therapies are increasingly used for patients with debilitating conditions where conventional treatments have failed. This review discusses the current understanding of the interplay between host genetics and the gut microbiome in the pathogenesis of spondyloarthropathies, and how this may relate to potential therapies for these conditions.