3 resultados para sterol
em Aston University Research Archive
Resumo:
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Resumo:
Fungi are ubiquitous organisms in nature and can be found in association with healthy eyes. The incidence of actual fungal infection of the eye, however, is relatively low compared with that attributable to viruses and bacteria. Nevertheless, fungal infection of the eye is increasing especially in immuno-compromised patients and a wide variety of fungal infections have now been described worldwide with species of Fusarium, Aspergillus, Candida, and dematiaceous fungi predominating. At present there are a limited number of compounds available to control ocular mycoses while resistance to anti-fungal agents has been growing in recent years, especially to azoles. Several mechanisms of resistance have been identified including modification of sterol synthesis pathways by the fungus, modification of enzymes to reduce the binding of azoles to fungal components and increased efficiency of removal of the azole within fungal cells. Although resistance to amphotericin-B has been reported, it continues to be the most important treatment for life-threatening conditions and more severe ophthalmic infections. Natamycin is often first choice for filamentous fungal keratitis and topical amphotericin-B for Candida keratitis. Continued monitoring of the behaviour of ocular fungi will be essential in future together with the development of new anti-fungal agents.
Resumo:
Extensive loss of adipose tissue is a hallmark of cancer cachexia but the cellular and molecular basis remains unclear. This study has examined morphologic and molecular characteristics of white adipose tissue in mice bearing a cachexia-inducing tumour, MAC16. Adipose tissue from tumour-bearing mice contained shrunken adipocytes that were heterogeneous in size. Increased fibrosis was evident by strong collagen-fibril staining in the tissue matrix. Ultrastructure of 'slimmed' adipocytes revealed severe delipidation and modifications in cell membrane conformation. There were major reductions in mRNA levels of adipogenic transcription factors including CCAAT/enhancer binding protein alpha (C/EBPα), CCAAT/enhancer binding protein beta, peroxisome proliferator-activated receptor gamma, and sterol regulatory element binding protein-1c (SREBP-1c) in adipose tissue, which was accompanied by reduced protein content of C/EBPα and SREBP-1. mRNA levels of SREBP-1c targets, fatty acid synthase, acetyl CoA carboxylase, stearoyl CoA desaturase 1 and glycerol-3-phosphate acyl transferase, also fell as did glucose transporter-4 and leptin. In contrast, mRNA levels of peroxisome proliferators-activated receptor gamma coactivator-1alpha and uncoupling protein-2 were increased in white fat of tumour-bearing mice. These results suggest that the tumour-induced impairment in the formation and lipid storing capacity of adipose tissue occurs in mice with cancer cachexia. © 2006 Cancer Research UK.