Current Issue : July - September Volume : 2012 Issue Number : 3 Articles : 6 Articles
Adiponectin is an important adipocyte-derived hormone that regulates metabolism of lipids and glucose, and its receptors (AdipoR1, AdipoR2, T-cadherin) appear to exert actions in peripheral tissues by activating the AMP-activated protein kinase, p38-MAPK, PPARα and NF-kappa B. Adiponectin has been shown to exert a wide range of biological functions that could elicit different effects, depending on the target organ and the biological milieu. The widespread physiological actions of adiponectin have now been well characterized as clinical studies and works in animal models have established strong correlations between circulating adiponectin level and various disease-related outcomes. Thus, conventional thinking attributes many of adiponectin’s beneficial effects to various tissue. However, it is now clear that several tissues can themselves produce adiponectin and there is growing evidence that locally produced adiponectin can mediate functionally important autocrine or paracrine effects. In this review article we discuss structure, its mechanism of action via receptor isoforms and signalling pathways, and its principal physiological effects....
Antiplatelet therapy has been documented to reduce risks of cardiovascular disease after acute myocardial infarction, coronary\r\nartery bypass graft, and in chronic atrial fibrillation patients, amongst other risk factors. Conventional management of thrombosisbased\r\ndisorders includes the use of heparin, oral anticoagulants, and the preferred antiplatelet agent aspirin. Interestingly, aspirin\r\nwas not intended to be used as an antiplatelet agent; rather, after being repurposed, it has become one of the most widely prescribed\r\nantithrombotic drugs. To this end, there have been several milestones in the development of antiplatelet agents in the last few\r\ndecades, such as adenosine diphosphate receptor inhibitors, phosphodiesterase inhibitors, and GPIIb/IIIa inhibitors. However,\r\ngiven some of the limitations of these therapies, aspirin continues to play a major role in the management of thrombotic and\r\ncardiovascular disorders and is expected to do so for years to come....
Background: Tumors are frequently hypoxic, affecting both chemotherapy and radiotherapy. Trans sodiumcrocetinate (TSC), a novel pharmaceutical agent, causes increases in oxygen levels of hypoxic tissues. It has alsobeen shown, in animal models of cancer, that radiotherapy is more effective when used in conjunction with TSC.An increase in tumor oxygen should also affect the HIF-1a pathway. Thus, an in vitro study of that pathway inhuman glioblastoma cells was performed.Methods: This study involved the use of quantitative real time polymerase chain reaction technology and humanglioblastoma multiforme cells. The cells were cultured under both hypoxic and normoxic conditions.Results: The inclusion of TSC in the media of the cells resulted in some genes in the HIF-1a pathway being eitherup- or down-regulated in a statistically-significant manner. These changes were opposite to those which occurredwhen the same cells were grown under hypoxic conditions but without TSC. In addition, those same genes reacted inan opposite manner when the cells were grown with TSC but under a normal oxygen environment.Conclusions: These results support previous observations that TSC reduces hypoxia in tumor cells. SinceTSC caused statistical differences in gene expression under hypoxia different from those caused under normoxia, itsuggests that there is not a direct effect of TSC on the HIF-1a pathway. Rather, TSC alters the gene expression dueto a change in the response of the genes to different oxygen levels. These data also correlate with previous in vivostudies which show that TSC increases oxygen to hypoxic tissue but not to normal tissue.Thus, these data, combined with previous studies of animal cancer models, strongly suggest that TSC has theability to increase cellular oxygen in tumor cells. Such a physiological change can be beneficial with combined withradiotherapy for cancer....
Alcohol is readily distributed throughout the body in the blood stream and crosses biological membranes, which affect virtually all\r\nbiological processes inside the cell. Excessive alcohol consumption induces numerous pathological stress responses, part of which\r\nis endoplasmic reticulum (ER) stress response. ER stress, a condition under which unfolded/misfolded protein accumulates in\r\nthe ER, contributes to alcoholic disorders of major organs such as liver, pancreas, heart, and brain. Potential mechanisms that\r\ntrigger the alcoholic ER stress response are directly or indirectly related to alcohol metabolism, which includes toxic acetaldehyde\r\nand homocysteine, oxidative stress, perturbations of calcium or iron homeostasis, alterations of S-adenosylmethionine to Sadenosylhomocysteine\r\nratio, and abnormal epigenetic modifications. Interruption of the ER stress triggers is anticipated to have\r\ntherapeutic benefits for alcoholic disorders....
Docosahexaenoic acid (DHA) is an omega-3 essential fatty acid that reduces the incidence and severity of a number of diseases. The (n-3) fatty acids are essential dietary nutrients, and one of their important roles is providing docosahexaenoic acid. DHA helps in growth and function of nervous tissue. Reduced DHA is associated with impairment in cognitive and behavioral performance, effects which are particularly important during brain development. Recently, a novel series of DHA-derived lipid mediators with potent protective actions have been identified. In the present review, we demonstrate the dietary amplification of these DHA-derived products and their role in protection of different disorders such as Alzheimer�s disease, mood disorders, cardiac complications as well as maintainence of pregnancy and vision. In vitro supplementation of hepatocytes with DHA significantly reduces hydrogen peroxide-induced damage, evaluated by the \"comet assay,\" and oxidative stress Deoxyribo Nucleic Acid, determined by measurement of malondialdehyde levels. Some of the commonly used dietary sources of DHA are Pink salmon filet, baked or broiled Pink salmon, White (albacore) tuna, Blue crab etc. It is also found in some herbal sources such as hemp, flax, sunflower and sesame as well as in nuts....
Hearing loss is the most common symptom in patients with vestibular schwannoma (VS). In the past, compressive mechanisms\r\ncaused by the tumoral mass and its growth have been regarded as the most likely causes of the hearing loss associated with\r\nVS. Interestingly, new evidence proposes molecular mechanisms as an explanation for such hearing loss. Among the molecular\r\nmechanisms proposed are methylation of TP73, negative expression of cyclin D1, expression of B7-H1, increased expression of the\r\nplatelet-derived growth factor A, underexpression of PEX5L, RAD54B, and PSMAL, and overexpression of CEA. Many molecular\r\nmechanisms are involved in vestibular schwannoma development; we review some of these mechanisms with special emphasis on\r\nhearing loss associated with vestibular schwannoma....
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