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1.
Shailesh Kumar Atma P. Dwivedi Vivek Kr. Kashyap A.K. Saxena A.K. Dwivedi Ranjana Srivastava Devi P. Sahu 《Bioorganic & medicinal chemistry letters》2013,23(8):2404-2407
Synthesis of a library of novel trans 6-methoxy-1,1-dimethyl-2-phenyl-3-aryl-2,3-dihydro-1H-inden-4-yloxy alkyl amines and their antimycobacterial activity against drug sensitive and multidrug resistant strains of Mycobacterium tuberculosis have been reported. All the new compounds in the series exhibited MIC between 1.56 and 6.25 μg/ml. Two compounds 1i and 1j with low MIC and low cytotoxicity showed significant reduction in CFU in infected mouse macrophages at 1× MIC concentration. The compound 1i inhibited the growth of M. tuberculosis in mice at 100 mg/kg dose with 1.35 log10 reduction of CFU in lungs tissue and was active against non-replicating Mycobacterium tuberculosis under anaerobic condition. 相似文献
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Microorganisms capable of metabolizing the herbicide metolachlor 总被引:3,自引:0,他引:3
We screened several strains of microorganisms and microbial populations for their ability to mineralize or transform the herbicide metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)-acetami de] because such cultures would potentially be useful in the cleanup of contaminated sites. Although we used various inocula and enrichment culture techniques, we were not able to isolate microorganisms that could mineralize metolachlor. However, strains of Bacillus circulans, Bacillus megaterium, Fusarium sp., Mucor racemosus, and an actinomycete were found to transform metolachlor. Several metabolites could be determined with high-performance liquid chromatography. The tolerance of the strains to high concentrations of metolachlor was also evaluated for the usefulness of the strains for decontamination. Tolerance of the actinomycete to metolachlor concentrations over 200 ppm (200 micrograms/ml) was low and could not be increased by doubling the sucrose concentration in the growth medium or by using a large biomass as inoculum. However, a Fusarium sp. could grow and transform metolachlor up to a concentration of 300 ppm. 相似文献
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U Saxena A Nagpurkar P J Dolphin S Mookerjea 《The Journal of biological chemistry》1987,262(7):3011-3016
Rat serum phosphorylcholine-binding protein (PCBP), a member of the pentraxin family of proteins, was previously shown to bind multilamellar liposomes prepared with egg phosphatidylcholine and lysophosphatidylcholine. The results suggested that the phosphorylcholine groups on the surface of liposomes play an important role in the binding process (Nagpurkar, A., Saxena, U., and Mookerjea, S. (1983) J. Biol Chem. 258, 10518-10523). A study on the binding of human plasma lipoproteins to PCBP immobilized on Sepharose has now been initiated. Very low density lipoproteins were partially bound to a Sepharose-PCBP column, and the bound fraction contained higher concentrations of apoprotein B and E. All the low density lipoproteins applied were bound to the column. In the case of high density lipoproteins, only a small fraction was retained on the column (based on protein analysis), and that bound fraction contained all the apoprotein E and Lp(a) lipoprotein. The binding of very low, low, and high density lipoproteins to Sepharose-PCBP was Ca2+-dependent, and the bound lipoproteins were quantitatively eluted by a phosphorylcholine gradient. Apoprotein B and E were also bound when whole human plasma was applied to Sepharose-PCBP. The effect of selective modification of lysine residues by acetoacetylation and of arginine residues by cyclohexanedione on the binding of low density lipoproteins to Sepharose-PCBP was examined. Modification of arginyl residues resulted in marked reduction of binding, whereas modification of lysine had no effect. Removal of sialic acid from PCBP also had no effect on the binding of low density lipoproteins to immobilized-desialylated PCBP column. The preferential binding of apoprotein B- and E-containing lipoproteins to Sepharose-PCBP indicates a possible physiological role of PCBP and other similar circulating phosphorylcholine-binding proteins of the pentraxin family in lipoprotein metabolism. 相似文献
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The process of spermiation and sperm transport was studied using specific inhibitors of cytoskeletal elements. Within 12-24 hr after the intratesticular injection of taxol, a compound that acts to stabilize microtubules and inhibit microtubule-related processes, an unusually large number of microtubules was seen within the body of the Sertoli cell. At the same time, transport of elements within the seminiferous epithelium was affected. At the end of stage VI of the cycle, step 19 spermatids were maintained in the deep recesses of the Sertoli cell and not transported to the rim of the seminiferous tubule lumen. At stage VIII, residual bodies remained at, or near, the rim of the tubule and were not transported to the base of the tubule. They underwent only partial degradation at this site, indicating that there may have been two phases involved in their dissolution--one autophagic and one phagocytic, but the latter did not occur since the residual bodies were not transported to Sertoli lysosomes at the base of the tubule. The observations suggest that microtubules are involved in transport processes within the seminiferous epithelium. Within 1-12 hr after the intratesticular injection of 500 microM cytochalasin D, a compound which interferes with actin-related processes, normal appearing tubulobulbar complexes were not present. The tubular portion (distal tube) of the complex did not initiate development. It was assumed that filaments (which were identified as such using NBD-phallacidin and the S-1 fragment of myosin) played an important role in the development of this portion of the complex. Cells did not eliminate cytoplasm normally, as evidenced by an enlarged cytoplasmic droplet, further emphasizing the published role for tubulobulbar complexes in cytoplasmic elimination. Although sperm were released normally from stage VIII tubules, many remained within the tubular lumen and did not traverse the duct system. Cytochalasin did not inhibit fluid secretion by the Sertoli cell, as demonstrated by efferent duct ligation, but did alter myoid cell actin cytoskeletal organization, suggesting that myoid cell contractility is primarily responsible for transport of sperm. Overall, the observations suggest that cytoskeletal activity of the Sertoli cell is important for several aspects of the spermiation process as well as sperm transport. 相似文献
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Herbicide Resistance in Datura innoxia: Cross-Resistance of Sulfonylurea-Resistant Cell Lines to Imidazolinones 总被引:3,自引:3,他引:0
Cells resistant to the sulfonylurea herbicides chlorsulfuron and sulfometuron methyl were isolated from a predominantly haploid cell suspension culture of Datura innoxia P. Mill. Exponentially growing cell colonies (aggregates of about 40 cells) were mutagenized with ethyl methane sulfonate, subcultured for 10 days to allow growth recovery and plated on a medium containing either chlorsulfuron or sulfometuron methyl at a concentration (10−8 molar) which killed wild type cells. Surviving clones were picked up after 3 to 4 weeks, further proliferated as callus or cell suspension cultures, and tested for their resistance to both the sulfonylureas and imidazolinones, a chemically different class of herbicides. The variants were stable and showed high (100- to 1000-fold) resistance to the sulfonylureas. While some also exhibited cross resistance to imidazolinones, others showed no cross-resistance at all or, as in one case, greater sensitivity than wild type cells to the imidazolinones. Both classes of herbicides tested inhibited acetolactate synthase activity isolated from wild type cells. The acetolactate synthase of the resistant variants, however, was found to be resistant to the sulfonylureas and also to the imidazolinone(s) in those cells showing cross-resistance to the latter. The lack of cross-resistance observed in some cases provides evidence that the two groups of herbicides have slightly different sites on the acetolactate synthase molecule. 相似文献
9.
Properties and characterization of a rat spleen cell-derived factor that induces resistance to natural killer cell lysis in YAC lymphoma cells 总被引:1,自引:0,他引:1
R K Saxena Q B Saxena W H Adler 《Journal of immunology (Baltimore, Md. : 1950)》1988,141(5):1782-1787
Supernatants of Con A-stimulated rat spleen cell cultures contain a factor that induces relative resistance to NK cell-mediated cytotoxicity in the YAC cell line, a line that is otherwise highly susceptible to murine NK cell-mediated lysis. This NK-lysis resistance-inducing factor (LRIF) has a Mr of 12,600 Da, as determined by gel filtration chromatography, and an isoelectric pH of 4.8. NK-LRIF is heat labile and is de-activated by treatment with proteolytic enzymes. Unlike immune-IFN (IFN-gamma), NK-LRIF is not inactivated by pH 2 treatment, and antibodies capable of neutralizing IFN-alpha and IFN-gamma do not abrogate the effect of NK-LRIF. Highly purified IL-2 preparations lack NK-LRIF activity. NK-LRIF does not induce a general resistance to lysis in YAC cells, because control and NK-LRIF-treated YAC cells were equally susceptible to alloimmune cytotoxic T cells. YAC cells treated with NK-LRIF showed a marked enhancement (5- to 10-fold) in the expression of class I MHC Ag. This observation supports the proposition that the NK susceptibility of target cells could be inversely related to the expression of class I MHC Ag. 相似文献
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A rapid, one-step procedure has been developed for inducing direct organogenesis and somatic embryogenesis in cultures of Phaseolus coccineus L., P. acutifolius A., P. aureus L. [Vigna radiata L. Wilczek] and P. wrightii L. Development of somatic embryos and shoot buds occurred within 6–8 weeks of culture from intact seedlings raised on MS (Murashige and Skoog 1962) medium supplemented with N6-benzylaminopurine (BAP). Shoot buds or embryoids originated from subepidermal tissue of the regions adjacent to the shoot apex, hypocotyl and cotyledonary axils. While P. acutifolius and P. aureus were regenerated via shoot formation and P. wrightii by somatic embryogenesis, both embryogenesis and shoot regeneration were observed in P. coccineus. Relatively higher levels of BAP, 50–80 M, were found to be optimal for inducing regeneration while lower concentrations were ineffective. About 40–70 shoots and 70–250 somatic embryos were produced per responding seedling. Regenerated shoots and somatic embryos developed into whole plants on a basal medium or the one supplemented with 1 M naphthaleneacetic acid. 相似文献