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61.
Peste des petits ruminants (PPR) is a highly contagious transboundary animal disease with a severe socio-economic impact on the livestock industry, particularly in poor countries where it is endemic. Full understanding of PPR virus (PPRV) pathobiology and molecular biology is critical for effective control and eradication of the disease. To achieve these goals, establishment of stable reverse genetics systems for PPRV would play a key role. Unfortunately, this powerful technology remains less accessible and poorly documented for PPRV. In this review, we discussed the current status of PPRV reverse genetics as well as the recent innovations and advances in the reverse genetics of other non-segmented negative-sense RNA viruses that could be applicable to PPRV. These strategies may contribute to the improvement of existing techniques and/or the development of new reverse genetics systems for PPRV. 相似文献
62.
Sodium chloride induced changes in leaf growth, and pigment and protein contents in two rice cultivars 总被引:2,自引:0,他引:2
A.N. Misra S.M. Sahu M. Misra P. Singh I. Meera N. Das M. Kar P. Sahu 《Biologia Plantarum》1997,39(2):257-262
Rice (Oryza sativa L.) seedlings were grown under NaCl stress. The leaf growth of resistant cv. Damodar was less affected
than that of the susceptible cv. Jaya. The leaf protein content showed no distinct cultivar or age dependent differences under
NaCl salinity. There was a significant increase in chlorophyll (Chl) and carotenoid (Car) contents of 25-d-oldseedlings of
both cv. Jaya and cv. Damodar. However, Chl and Car content of 15-d-old seedlings of cv. Jaya decreased and that of cv. Damodar
increased, under NaCl stress.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
63.
Rapid detection of 6-phosphogluconate dehydrogenase variants by electrophoresis on cellulose acetate gel 总被引:3,自引:0,他引:3
A procedure, suitable even under field conditions for the rapid detection of 6-phosphogluconate dehydrogenase electrophoretic variants, is described.Work supported by N.I.H.—grant no. ROI GM 13415. 相似文献
64.
The peel and pulp of the banana fruit and the pseudostem were examined for glutamate-oxaloacetate transaminase (GOT), glutamate-pyruvate transaminase (GPT) and aldolase activities and protein, phenolics, chlorophyll and starch. The peel-pulp ratio at various stages of fruit development on the plant and in detached fruits showing incipient ripening were used as an index of the physiological age of the fruit. The enzymes exhibited maximum activity at a stage corresponding to the initiation of the climacteric. GPT level at this stage was higher than that of GOT. An initial increase in the protein content was followed by a decline in both peel and pulp, the level reaching a minimum in climacteric fruits. Astringency, measured in terms of total phenolics, decreased with development; in mature fruits, peel contained 4–5 × as much phenolics as pulp. Chlorophyll in mature fruits was 10 × higher than in young fruits and decreased in ripe fruits. The onset of ripening was attended with a pronounced decrease in the starch. The various analyses were carried out also on the pseudostem removed from the plant soon after flower formation. 相似文献
65.
66.
Shiranee Sriskandan Meera Unnikrishnan Thomas Krausz & Jonathan Cohen 《Molecular microbiology》1999,33(4):778-790
Epidemiological studies strongly implicate the bacterial superantigen, streptococcal pyrogenic exotoxin A (SPEA), in the pathogenesis of necrotizing soft-tissue infection and toxic shock syndrome resulting from Streptococcus pyogenes. SPEA can act as a superantigen and cellular toxin ex vivo, but its role during invasive streptococcal infection is unclear. We have disrupted the wild-type spea gene in an M1 streptococcal isolate. Supernatants from toxin-negative mutant bacteria demonstrated a 50% reduction in pro-mitogenic activity in HLA DQ-positive murine splenocyte culture, and up to 20% reduction in activity in human PBMC culture. Mutant and wild-type bacteria were then compared in mouse models of bacteraemia and streptococcal muscle infection. Disruption of spea was not associated with attenuation of virulence in either model. Indeed, a paradoxical increase in mutant strain-induced mortality was seen after intravenous infection. Intramuscular infection with the SPEA-negative mutant led to increased bacteraemia at 24 h and a reduction in neutrophils at the site of primary muscle infection. Purified SPEA led to a dose-dependent increase in peritoneal neutrophils 6 h after administration. SPEA is not a critical virulence factor in invasive soft-tissue infection or bacteraemia caused by S. pyogenes, and it could have a protective role in murine immunity to pyogenic infection. The role of this toxin may be different in hosts with augmented superantigen responsiveness. 相似文献
67.
Ball AL Chambers KA Hewinson M Navaratnarajah S Samrin L Thomas N Tyler AE Wall AJ Lloyd MD 《Journal of enzyme inhibition and medicinal chemistry》2008,23(1):131-135
Glycosidases perform a wide range of functions in physiology and pathology, and are potential targets for the treatment of diseases such as influenza, cancer, AIDS and diabetes. This paper reports a convenient discontinuous colourimetric assay for the measurement of glycosidase activity. The assay utilises 4-nitrophenyl- substrates and quantities of product are determined by measuring absorbance at 405 nm. This assay is performed in a 96 well microtitre plate and has been used to characterise the properties of seven different glycosidases from bacteria, yeast and higher eukaryotes and their kinetic parameters determined. Assays in the presence of known inhibitors showed that inhibition modes can be determined, and IC(50) and K(i) values calculated. This assay appears to be of widely applicable and of general utility for the measurement of glycosidase activity and the evaluation of inhibitors. 相似文献
68.
69.
Unicellular tubes or capillaries composed of individual cells with a hollow lumen perform important physiological functions including fluid or gas transport and exchange. These tubes are thought to build intracellular lumina by polarized trafficking of apical membrane components, but the molecular signals that promote luminal growth and luminal connectivity between cells are poorly understood. Here we show that the lipocalin LPR-1 is required for luminal connectivity between two unicellular tubes in the Caenorhabditis elegans excretory (renal) system, the excretory duct cell and pore cell. Lipocalins are a large family of secreted proteins that transport lipophilic cargos and participate in intercellular signaling. lpr-1 is required at a time of rapid luminal growth, it is expressed by the duct, pore and surrounding cells, and it can function cell non-autonomously. These results reveal a novel signaling mechanism that controls unicellular tube formation, and provide a genetic model system for dissecting lipocalin signaling pathways. 相似文献
70.
Das T Banerjee S Samuel G Bapat K Subramanian S Pillai MR Venkatesh M 《Bioorganic & medicinal chemistry letters》2006,16(22):5788-5792
With an insight that ligands possessing a N2S2 tetradentate array of donor atoms serve as ideal bifunctional chelating agents (BFCA) in the radiolabeling of target-specific agents, 5-hydroxy-3,7-diazanonan-1,9-dithiol (DAHPES) with a derivatizable substituent in the form of a hydroxyl group in the backbone was synthesized. The preparation of a steroid conjugate via coupling of this BFCA with testosterone-3-(O-carboxymethyl) oxime and the subsequent radiolabeling of the conjugate under optimized conditions with 99mTc, the ideal diagnostic radionuclide in nuclear medicine procedures, are reported. The immunoreactivity of the radiolabeled conjugate was demonstrated in a study using anti-testosterone antibodies, wherein the radiolabeled conjugate exhibited significant binding with antiserum to testosterone. Cell-uptake studies in DU145 prostate carcinoma cell line bearing androgen receptors (ARs) and comparison with AR non-bearing breast carcinoma cell line revealed the specific binding of the steroidal moiety with the testosterone receptor. 相似文献