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81.
Ambastha Vivek Chauhan Garima Tiwari Budhi Sagar Tripathy Baishnab C 《Protoplasma》2020,257(3):841-851
Protoplasma - Absorption of excess excitation energy induces overproduction of singlet oxygen (1O2) in plants. The major sources of singlet oxygen production are chlorophyll and its intermediates... 相似文献
82.
Haq Abdul Shaik Archana Mishra Hany M. Hussein Oxana Skoková Habuštová František Sehnal 《Journal of Applied Entomology》2020,144(6):481-490
Entomopathogenic nematodes and parasitoid larvae of some wasps play important roles in the natural control of the pest insects. However, it has not been excluded that competition between nematodes and wasps may in some cases reduce their efficacy in the pest control. Using caterpillars of Spodoptera littoralis, we examined interactions between the nematode Steinernema carpocapsae and the venom of the parasitoid Habrobracon hebetor. The survival of S. littoralis caterpillars was reduced in a dose-dependent manner when 5 to 500 nematodes or 0.005–0.1 venom units were applied to single caterpillars. High doses of either nematodes or the venom caused death within 1–3 days in all treated hosts. The low doses of nematodes killed caterpillars within a week, in some cases when they attempted to pupate. Caterpillars receiving low venom doses were characterized by extended survival time terminated with death due to starvation. Combined treatment of nematodes and the venom were mutually synergistic and elicited severe lethal effects. The nematodes were fully resistant to the venom and can feed and grow on the symbiotic bacteria in vitro. The venom impairs food processing and causes death of caterpillars due to starvation. Disruption of the hormonal regulation of metamorphosis by ecdysteroids and juvenile hormone could be responsible for defective moults block at different stages of the moulting process, regionally restricted moulting, moults to “intermediates” combining regions of newly secreted larval and pupal cuticles. 相似文献
83.
Asish K. Sen Amal K. Mukherjee Bhakti Guhathakurta Archana Dutta Dipti Sasmal 《Carbohydrate research》1979
On hydrolysis, the purified lipopolysaccharide (LPS) isolated from Vibrio cholera, Inaba 569 B, yielded glucose, mannose, a heptose behaving like d-glycero-l-manno-heptose and one behaving like d-glycero-l-gluco-heptose, 2-amino-2-deoxy-glucose, and glucuronic acid in the molar ratios of ~9:4:5:1:2:5. Studies on the LPS, the polysaccharide (PS), and carboxyl-reduced LPS showed that the PS has a branched structure, with (1→2)-linked mannopyranosyl and a heptopyranosyl, and (1→4)-linked glucopyranosyluronic and 2-amino-2-deoxyglucopyranosyl residues in the interior part of the molecule, and glucopyranosyl and heptopyranosyl residues as nonreducing end-groups. 相似文献
84.
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86.
Src kinase activity is essential for osteoclast function 总被引:21,自引:0,他引:21
Miyazaki T Sanjay A Neff L Tanaka S Horne WC Baron R 《The Journal of biological chemistry》2004,279(17):17660-17666
Deletion of the c-src gene impairs osteoclast bone resorbing activity, causing osteopetrosis. Although it has been concluded that restoring only the Src adaptor function at least partly rescues the cell attachment and skeletal phenotypes, the contribution of Src kinase activity remains controversial. Src forms a complex with Pyk2 and Cbl after adhesion-induced stimulation of alpha(V)beta(3) integrin. To demonstrate the importance of the Pyk2-Src association in osteoclasts and to distinguish the contributions of the Src adaptor and kinase activities in cytoskeletal organization and osteoclast function, we expressed mutants of Src and Pyk2 in osteoclasts using adenovirus vectors. Eliminating the Src-binding site on Pyk2 (Pyk2(Y402F)) markedly inhibited bone resorption by osteoclast-like cells, whereas kinase-dead Pyk2 had little effect. Kinase-dead Src, unlike kinase-dead Pyk2, markedly inhibited the bone-resorbing activity of wild type osteoclasts and failed to significantly restore bone-resorbing activity to Src(-/-) osteoclast-like cells. Activation of Src kinase by overexpressing kinase-dead Csk failed to reverse the inhibitory effect of Pyk2(Y402F), suggesting that osteoclastic bone resorption requires both c-Src kinase activity and the targeting of Src kinase by Pyk2. Src-catalyzed phosphorylation of Cbl on Tyr-731 is reported to induce the activation and recruitment of phosphatidylinositol 3-kinase to the cell membrane in a signaling pathway that is critical for osteoclast function. Expressing the Cbl(Y731F) mutant in osteoclasts markedly reduced their bone resorbing activity, suggesting that phosphorylation of Cbl(Y731) and the subsequent recruitment and activation of phosphatidylinositol 3-kinase may be critical signaling events downstream of Src in osteoclasts. 相似文献
87.
An essential aspect of the treatment of patients with cardiovascular disease is the use of anticoagulant and antiplatelet agents for the prevention of further ischaemic events and vascular death resulting from thrombosis. Aspirin and heparin have been the standard therapy for the management of such conditions to date. Recently, numerous more potent platelet inhibitors together with anticoagulant agents have been developed and tested in randomized clinical trials. This article reviews the current state of the art of antiplatelet and anticoagulant therapy in light of its potential clinical efficacy. It then focuses on the usages of these agents in order to improve the performance of clinical devices such as balloon catheters, coronary stents, and femoropopliteal bypass grafting and extra corporeal circuits for cardiopulmonary bypass. The article then goes on to look at the usage of these agents more specifically heparin, heparan, hirudin, and coumarin in the development of more biocompatible scaffolds for tissue engineering. 相似文献
88.
Implantation of blastocysts involves conversion of maternal and embryonic cell surfaces from a nonadhesive to an adhesive state in response to the internally driven developmental program or to externally generated factors. However, the intricacies of the cellular and subcellular changes that promote the attachment are not known, because these changes are difficult to determine in situ because of the nonaccessibility of the site. To overcome this, an in vitro model of implantation was developed by co-culturing rat blastocysts and uterine epithelial cells of the same gestational age (day 5 postcoitum; plug day as day 1) in drops hanging from the lid of a Petri dish. The system was used to study the changes on the surface membranes of the cells of the trophectoderm and uterine epithelium and to evaluate the antiadhesive activity of the newly designed test substances. The isolated epithelial cell vesicles were co-cultured with zona-free blastocysts in the microdrops (40–50 µl) hanging from the lid of a 60-mm Petri dish. The lid was placed over the lower dish, which was presaturated with the medium. The culture was examined 48 h later to determine the site of adhesion of epithelial cell vesicles with the trophoblasts lining the blastocyst. The cell-cell adhesion was monitored on a computerized image analyzer. To validate the adhesion of blastocysts and epithelial cell vesicles in co-culture, the expression of a cell adhesion molecule, uvomorulin, was studied using immunocytochemical technique after incubating with antiuvomorulin antibody. Intense staining was noted on the membrane surfaces at the site of attachment of the blastocyst and cell vesicles.The authors express their sincere thanks to the Ministry of Health and Family Welfare, Government of India, for their financial support 相似文献
89.
Cenchrus (family Poaceae) is an important component of major grass covers of the world. Largely it is apomictic and both annual and perennial species
exist in nature. Variations in contents of malondialdehyde, proline, specific leaf area and carbon isotope discrimination
for drought tolerance were estimated among eight prominent species of Cenchrus. Simultaneously, genetic variations were also estimated by employing 187 RAPD primers. Of these, 23 primers did not react,
2 performed poorly and 7 produced many non-scorable bands and one primer yielded a single monomorphic band. Rest of the 154
primers generated one or more unambiguously scorable fragments. Twelve hundred and four of the 1,296 putative loci were polymorphic
(93%) between at least one pair-wise comparisons among eight species. Dice coefficient and neighbor-joining algorithm analyses
showed clustering patterns that fit with the known habitat of the species except perennial, C. myosuroides which formed a node between two annuals species. When these species were subjected to water stress tolerance test, a correlation
(r = 0.612) between specific leaf area (SLA) and carbon isotope discrimination (CID) and difference in levels of drought tolerance
based parameters among eight species were observed. Of the eight species investigated two annuals viz., C. biflorus and C. echinatus showed highest level of genetic similarity which was also evident from the similar levels of SLA, MDA, proline contents and
carbon isotope discrimination values observed in these two species. 相似文献
90.
Rohit Lall George Thomas Satendra Singh Archana Singh Gulshan Wadhwa 《Bioinformation》2013,9(18):923-928
Solanum lycopersicum and Solanum tuberosum are agriculturally important crop species as they are rich sources of starch, protein,
antioxidants, lycopene, beta-carotene, vitamin C, and fiber. The genomes of S. lycopersicum and S. tuberosum are currently available.
However the linear strings of nucleotides that together comprise a genome sequence are of limited significance by themselves.
Computational and bioinformatics approaches can be used to exploit the genomes for fundamental research for improving their
varieties. The comparative genome analysis, Pfam analysis of predicted reviewed paralogous proteins was performed. It was found
that S. lycopersicum proteins belong to more families, domains and clans in comparison with S. tuberosum. It was also found that
mostly intergenic regions are conserved in two genomes followed by exons, intron and UTR. This can be exploited to predict
regions between genomes that are similar to each other and to study the evolutionary relationship between two genomes, leading
towards the development of disease resistance, stress tolerance and improved varieties of tomato. 相似文献