The severe acute respiratory syndrome coronavirus (SARS-CoV) 8b protein, which is not expressed by other known coronaviruses, can down-regulate the envelope (E) protein via a proteasome-dependent pathway. Here, we showed that the down-regulation of E is not dependent on the lysine residues on 8b and the reduction of polyubiquitination of E mutants is not correlated with their down-regulation by 8b, suggesting an ubiquitin-independent proteasome pathway is involved. A time-course study revealed that 8b was expressed at late-stages of SARS-CoV infection. By using Vero E6 cells stably expressing green fluorescence protein-tagged 8b, ectopic expression of 8b was shown to significantly reduce the production of progeny virus and down-regulate E expression. Taken together, these results suggest that 8b negatively modulates virus replication by down-regulating E via an ubiquitin-independent proteasome pathway. 相似文献
Protease inhibitors are well known to have several applications in medicine and biotechnology. Several plant sources are known to return potential protease inhibitors. In this study plants belonging to different families of Leguminosae, Malvaceae, Rutaceae, Graminae and Moringaceae were screened for the protease inhibitor. Among them Moringa oleifera, belonging to the family Moringaceae, recorded high level of protease inhibitor activity after ammonium sulfate fractionation. M. oleifera, which grows throughout most of the tropics and having several industrial and medicinal uses, was selected as a source of protease inhibitor since so far no reports were made on isolation of the protease inhibitor. Among the different parts of M. oleifera tested, the crude extract isolated from the mature leaves and seeds showed the highest level of inhibition against trypsin. Among the various extraction media evaluated, the crude extract prepared in phosphate buffer showed maximum recovery of the protease inhibitor. The protease inhibitor recorded high inhibitory activity toward the serine proteases thrombin, elastase, chymotrypsin and the cysteine proteases cathepsin B and papain which have more importance in pharmaceutical industry. The protease inhibitor also showed complete inhibition of activities of the commercially available proteases of Bacillus licheniformis and Aspergillus oryzae. However, inhibitory activities toward subtilisin, esperase, pronase E and proteinase K were negligible. Further, it was found that the protease inhibitor could prevent proteolysis in a commercially valuable shrimp Penaeus monodon during storage indicating the scope for its application as a seafood preservative. This is the first report on isolation of a protease inhibitor from M. oleifera. 相似文献
A pot experiment was investigated to study the effect of sewage irrigation treatments (primary and secondary effluents) compared with tap water on the growth and chemical constituents of mahogany seedlings (Swietenia mahagoni (L.) Jacq.) as well as soil chemical properties. The experiment was conducted at a greenhouse in the nursery of Timber Trees Research Department of Sabahia, Horticultural Research Station in Alexandria, Egypt, from June 2003 to December 2004 for three irrigation periods (6, 12 and 18 months). The sewage effluent waters were taken from oxidation ponds located in New Borg EL-Arab city and used directly for irrigation.The primary effluent treatment was superior than other treatments in improving the growth parameters (plant height, stem diameter, leaf area, leaves number, fresh and dry weights of leaves, shoots and roots and shoot/root ratio) and showed the highest concentration and total uptake of N, P, K, Cd, Ni, Pb and Fe in plant parts, followed by secondary effluent then tap water. The data revealed that soil salinity in terms of electrical conductivity of saturated paste (EC), CaCO3%, organic matter% and soluble anions and cations were influenced significantly by primary or secondary effluent treatment. The data also showed that the use of sewage effluent for irrigation increased N, P, K and DTPA-extractable-heavy metals (Cd, Cu, Ni, Pb, Fe, Mn and Zn). The effects of sewage effluent on growth parameters and elements content in plant parts and treated soil were more pronounced as water treatments were used for long period.The results suggested that the use of sewage effluent in irrigating mahogany trees grown on calcareous sandy loam soil was an important agriculture practice for improving soil properties, increasing fuel and timber production, and is an economic and safe way to dispose wastewaters. 相似文献
Drug discovery in skin pharmacotherapy is an enormous, continually expanding field. Researchers are developing novel and sensitive
pharmaceutical products and drugs that target specific receptors to elicit concerted and appropriate responses. The pigment-bearing
cells called melanophores have a significant contribution to make in this field. Melanophores, which contain the dark brown
or black pigment melanin, constitute an important class of chromatophores. They are highly specialized in the bidirectional
and coordinated translocation of pigment granules when given an appropriate stimulus. The pigment granules can be stimulated
to undergo rapid dispersion throughout the melanophores, making the cell appear dark, or to aggregate at the center, making
the cell appear light. The major signals involved in pigment transport within the melanophores are dependent on a special
class of cell surface receptors called G-protein-coupled receptors (GPCRs). Many of these receptors of adrenaline, acetylcholine,
histamine, serotonin, endothelin and melatonin have been found on melanophores. They are believed to have clinical relevance
to skin-related ailments and therefore have become targets for high throughput screening projects. The selective screening
of these receptors requires the recognition of particular ligands, agonists and antagonists and the characterization of their
effects on pigment motility within the cells. The mechanism of skin pigmentation is incredibly intricate, but it would be
a considerable step forward to unravel its underlying physiological mechanism. This would provide an experimental basis for
new pharmacotherapies for dermatological anomalies. The discernible stimuli that can trigger a variety of intracellular signals
affecting pigment granule movement primarily include neurotransmitters and hormones. This review focuses on the role of the
hormone and neurotransmitter signals involved in pigment movement in terms of the pharmacology of the specific receptors. 相似文献
We aimed to show the effect of osteoporosis on sleep quality in 59 postmenopausal women. The participants’ bone-mineral density levels were measured by dual-energy X-ray absorptiometry (DEXA). According to their DEXA results, participants were divided into two groups as osteoporotics and controls. The Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep quality. Fourteen osteoporotic women (43.8%) and four controls (14.8%) were “poor” sleepers (p < 0.05). Postmeno-pausal women with osteoporosis scored greater on the “sleep latency” and “sleep duration” components of PSQI than controls. According to the findings of our study, osteoporosis is a risk factor for poor sleep quality in postmenopausal women.
The potential for parallel impacts of habitat change on multiple biodiversity levels has important conservation implications. We report on the first empirical test of the 'species-genetic diversity correlation' across co-distributed taxa with contrasting ecological traits in the context of habitat fragmentation. In a rainforest landscape undergoing conversion to oil palm, we show that depauperate species richness in fragments is mirrored by concomitant declines in population genetic diversity in the taxon predicted to be most susceptible to fragmentation. This association, not seen in the other species, relates to fragment area rather than isolation. While highlighting the over-simplification of extrapolating across taxa, we show that fragmentation presents a double jeopardy for some species. For these, conserving genetic diversity at levels of pristine forest could require sites 15-fold larger than those needed to safeguard species numbers. Importantly, however, each fragment contributes to regional species richness, with larger ones tending to contain more species. 相似文献
Contemporary sequencing studies often ignore the diploid nature of the human genome because they do not routinely separate or 'phase' maternally and paternally derived sequence information. However, many findings - both from recent studies and in the more established medical genetics literature - indicate that relationships between human DNA sequence and phenotype, including disease, can be more fully understood with phase information. Thus, the existing technological impediments to obtaining phase information must be overcome if human genomics is to reach its full potential. 相似文献
To improve the management of leishmaniasis, new drugs and/or alternative therapeutic strategies are required. Combination therapy of antileishmanial drugs is currently considered as one of the most rational approaches to lower treatment failure rate and limit drug resistance spreading. Nicotinamide (NAm), also known as vitamin B3 that is already is used in human therapy, exerts in vitro antileishmanial activity. Drug combination studies, performed on L. infantum axenic amastigotes, revealed that NAm significantly improves the antileishmanial activity of trivalent antimony in a synergistic manner while it shows additive activity with amphotericin B and slightly antagonizes pentamidine activity. NAm also significantly increases the toxicity of pentavalent antimony against the intracellular forms of L. infantum, L. amazonensis and L. braziliensis. The potential of NAm to be used as adjuvant during leishmaniasis chemotherapy is further discussed. 相似文献
A recently discovered occult HCV entity reported by various investigators seems to be highly controversial. Especially, the clinical significance of these findings remains uncertain. For optimal outcome of antiviral therapy, investigation of occult HCV needs a broad-based probe in order to investigate the results of viral therapy and its host/viral interaction. The current study was aimed at determining the prevalence of occult HCV in peripheral blood lymphocytes of predominantly genotype 3 HCV-infected patients after completion of antiviral therapy and to investigate long term outcomes in the presence or absence of PBMC positivity.
Method
A total of 151 chronic, antiHCV and serum RNA-positive patients were enrolled in the study. Patients with a complete virological response at the end of treatment were screened for the presence of viral RNA in their PBMCs and were followed for up to one year for the presence of serum and PBMC viral genomic RNA.
Results
Out of 151 patients, 104 (70%) responded to the prescribed interferon treatment and showed viral-clearance from serum. These were screened for the presence of genomic RNA in their PBMCs. Sixteen samples were PBMC-positive for viral RNA at the end of treatment (EOT). All these patients had also cleared the virus from peripheral blood cells after the 6-12 month follow-up study.
Conclusion
True occult hepatitis C virus does not exist in our cohort. Residual viremia at the EOT stage merely reflects a difference in viral kinetics in various compartments that remains a target of immune response even after the end of antiviral therapy and is eventually cleared out at the sustained viral response (SVR). 相似文献