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871.
Vrinda S. Thaker Sant Saroop Pankaj P. Vaishnav Yash Dev Singh 《Journal of Plant Growth Regulation》1986,5(1):17-27
Cytoplasmic and salt-extracted wall peroxidase and nonspecific esterase activities along with growth analysis were investigated during the entire period of cotton fiber development. Both the peroxidase fractions, when assayed with chlorogenic and ferulic acids as substrates, recorded low levels during the fiber elongation phase, and a close relationship between cessation of elongation growth and increase in peroxidase activity was discernible. Nonspecific esterase activity in both cytoplasmic and salt-extracted fractions, on the other hand, showed higher activity during the elongation phase, whereas during the secondary thickening phase it decreased. The role of cytoplasmic peroxidase in IAA oxidation is discussed. It is suggested that esterases and peroxidases associated with wall fractions may well be involved in turnover of phenolic acids that are cross-linked to wall polysaccharides. 相似文献
872.
Epratuzumab has demonstrated therapeutic activity in patients with non-Hodgkin lymphoma, acute lymphoblastic leukemia, systemic lupus erythematosus, and Sjögren''s syndrome, but its mechanism of affecting normal and malignant B cells remains incompletely understood. We reported previously that epratuzumab displayed in vitro cytotoxicity to CD22-expressing Burkitt lymphoma cell lines (Daudi and Ramos) only when immobilized on plates or combined with a crosslinking antibody plus a suboptimal amount of anti-IgM (1 μg/mL). Herein, we show that, in the absence of additional anti-IgM ligation, extensive crosslinking of CD22 by plate-immobilized epratuzumab induced intracellular changes in Daudi cells similar to ligating B-cell antigen receptor with a sufficiently high amount of anti-IgM (10 μg/mL). Specifically, either treatment led to phosphorylation of CD22, CD79a and CD79b, along with their translocation to lipid rafts, both of which were essential for effecting caspase-dependent apoptosis. Moreover, such immobilization induced stabilization of F-actin, phosphorylation of Lyn, ERKs and JNKs, generation of reactive oxygen species (ROS), decrease in mitochondria membrane potential (Δψm), upregulation of pro-apoptotic Bax, and downregulation of anti-apoptotic Bcl-xl and Mcl-1. The physiological relevance of immobilized epratuzumab was implicated by noting that several of its in vitro effects, including apoptosis, drop in Δψm, and generation of ROS, could be observed with soluble epratuzumab in Daudi cells co-cultivated with human umbilical vein endothelial cells. These results suggest that the in vivo mechanism of non-ligand-blocking epratuzumab may, in part, involve the unmasking of CD22 to facilitate the trans-interaction of B cells with vascular endothelium. 相似文献
873.
AbstractSelective activation of the cannabinoid receptor subtype 2 (CB2) shows promise for treating pain, inflammation, multiple sclerosis, cancer, ischemic/reperfusion injury and osteoporosis. Target selectivity and off-target side effects are two major limiting factors for orthosteric ligands, and therefore, the search for allosteric modulators (AMs) is a widely used drug discovery approach. To date, only a limited number of negative CB2 AMs have been identified, possessing only micromolar activity at best, and the CB2 receptor’s allosteric site(s) are not well characterized. Herein, we used computational approaches including receptor modeling, site mapping, docking, molecular dynamics (MD) simulations and binding free energy calculations to predict, characterize and validate allosteric sites within the complex of the CB2 receptor with bound orthosteric agonist CP55,940. After docking of known negative CB2 allosteric modulators (NAMs), dihydro-gambogic acid (DHGA) and trans-β-caryophyllene (TBC) (note that TBC also shows agonist activity), at the predicted allosteric sites, the best total complex with CB2, CP55,940 and NAM was embedded into a hydrated lipid bilayer and subjected to a 200 ns MD simulation. The presence of an AM affected the CB2–CP55,940 complex, altering the relative positioning of the toggle switch residues and promoting a strong π–π interaction between Phe1173.36 and Trp2586.48. Binding of either TBC or DHGA to a putative allosteric pocket directly adjacent to the orthosteric ligand reduced the binding free energy of CP55,940, which is consistent with the expected effect of a negative AM. The identified allosteric sites present immense scope for the discovery of novel classes of CB2 AMs. 相似文献
874.
Pankaj Ganguly Harvey R. Bradford 《Biochimica et Biophysica Acta (BBA)/General Subjects》1982,714(2):192-199
The aggregation of human blood platelets by thrombin, adenosine diphosphate, wheat germ agglutinin or ristocetin was inhibited by primary amines. In general, thrombin-induced platelet aggregation was strongly affected by the amines while the effect was weak on cell aggregation by ristocetin. Usually, the diamines were stronger inhibitors of aggregation than the monoamines with cadaverine as the strongest and ethylamine as the weakest inhibitor. At concentration where platelet aggregation was inhibited, the amines neither displaced serotonin from serotinin-loaded platelets nor caused lysis of human red cells. The lectin activity of wheat germ agglutinin on human red cells was not affected by the amines indicating that the amines probably acted on platelets and not on the agglutinin. The clotting activity of thrombin on fibrinogen was partially inhibited by the amines while its esterolytic activity remained unaltered. The inhibitory action of the amines on platelet aggregation could be overcome with small amounts of calcium while other divalent cations tested had little effect. It is suggested that the amines affect platelet aggregation by interfering with the actions of membrane-associated calcium. 相似文献
875.
Pankaj Srivastava Amrit Kumar Soumit K. Behera Yogesh K. Sharma Nandita Singh 《Biodiversity and Conservation》2012,21(5):1343-1358
Global warming due to increasing greenhouse gases emission and the subsequent climatic changes are the most serious environmental
challenges faced by environmental scientists, academicians, regulatory agencies and policy makers worldwide. Among the various
greenhouse gases, CO2 constitutes a major share and its concentration is increasing rapidly. Therefore, there is perhaps an urgent need to formulate
suitable policies and programs that can firmly reduce and sequester CO2 emissions in a sustainable way. In order to combat the predicted disaster due to rising CO2 level, several CO2 capture and storage technologies and medium are being widely pursued and deliberated. Among them soil carbon sequestration
(SCS) is gaining global attention because of its stability and role in long-term surface reservoir, natural low cost and eco-friendly
means to combat climate change. Apart from the carbon capturing, the process of soil carbon stabilization also provides other
tangible benefits that includes achieving food security, by improving soil quality, wasteland reclamation and preventing soil
erosion. The present article aimed to address all these concerns and provide strategies and critical research needs to implement
SCS as a mitigation option for increasing atmospheric CO2 level and its future directions. 相似文献
876.
Vitthal Awad Rohit Shirke Sourav Mukherjee Suresh Khadke Pankaj Pawar Nilambika Meti Abhay Harsulkar 《In vitro cellular & developmental biology. Plant》2011,47(4):525-535
Taverniera cuneifolia (Roth) Arn. or Indian licorice is considered to be a substitute for Glycyrrhiza glabra L. owing to an equivalent content of glycyrrhizic acid (GA). GA recognized as the main active ingredient of T. cuneifolia, GA imparts several medicinal properties to these plants. However, research on this plant is scanty with no published record
on tissue culture studies. Present study demonstrates a method for (1) induction and successful development of somatic embryos
from the root culture, (2) regeneration of plants, and (3) GA production by root cultures of T. cuneifolia. Shoot initiation frequency of cultured roots ranged from 52.57% to 97.71%. Plant regeneration frequency (germination) from
somatic embryos was 88.66% in 1/4-strength Murashige and Skoog (MS) medium supplemented with 2% sucrose, as against 68% in
half 1/2-strength MS containing 2% sucrose. Glycyrrhizic acid of 1.32 mg/gm of dry weight was obtained in full-strength MS
medium supplemented with 3% sucrose, through high-performance thin layer chromatography analysis with standard GA in root
cultures. The present study provides an efficient method for the mass production of plants from a single mother plant as well
as the potential root culture system to study the GA production pathways in T. cuneifolia. 相似文献
877.
Ashutosh Kumar Verma Chandralata Raghukumar Pankaj Verma Yogesh S. Shouche Chandrakant Govind Naik 《Biodegradation》2010,21(2):217-233
Textile dye effluents pose environmental hazards because of color and toxicity. Bioremediation of these has been widely attempted.
However, their widely differing characteristics and high salt contents have required application of different microorganisms
and high dilutions. We report here decolorization and detoxification of two raw textile effluents, with extreme variations
in their pH and dye composition, used at 20–90% concentrations by each of the four marine-derived fungi. Textile effluent
A (TEA) contained an azo dye and had a pH of 8.9 and textile effluent B (TEB) with a pH of 2.5 contained a mixture of eight
reactive dyes. The fungi isolated from mangroves and identified by 18S and ITS sequencing corresponded to two ascomycetes
and two basidiomycetes. Each of these fungi decolorized TEA by 30–60% and TEB by 33–80% used at 20–90% concentrations and
salinity of 15 ppt within 6 days. This was accompanied by two to threefold reduction in toxicity as measured by LC50 values against Artemia larvae and 70–80% reduction in chemical oxygen demand and total phenolics. Mass spectrometric scan
of effluents after fungal treatment revealed degradation of most of the components. The ascomycetes appeared to remove color
primarily by adsorption, whereas laccase played a major role in decolorization by basidiomycetes. A process consisting of
a combination of sorption by fungal biomass of an ascomycete and biodegradation by laccase from a basidiomycete was used in
two separate steps or simultaneously for bioremediation of these two effluents. 相似文献
878.
Peristylus sahanii (Orchidaceae), a new species from Jharkhand state (Chotanagpur plateau), India is described and illustrated. 相似文献
879.