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21.
Biflavonoids from Lonicera japonica 总被引:7,自引:0,他引:7
Two biflavonoids, 3'-O-methyl loniflavone [5,5',7,7'-tetrahydroxy 3'-methoxy 4',4'-biflavonyl ether (1)] and loniflavone [5,5',7,7',3'-pentahydroxy 4',4'-biflavonyl ether (2)] along with luteolin (3) and chrysin (4) were isolated from the leaves of Lonicera japonica. The structures were established on the basis of UV/vis, 1D, 2D NMR (HMQC and HMBC) and ESI-QTOF-MS/MS spectroscopic methods and chemical evidences. 相似文献
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Swati Haldar Ajai Tripathi Juan Qian Amber Beserra Srinivas Suda Matthew McElwee Jerrold Turner Ulrich Hopfer Neena Singh 《The Journal of biological chemistry》2015,290(9):5512-5522
Brain iron-dyshomeostasis is an important cause of neurotoxicity in prion disorders, a group of neurodegenerative conditions associated with the conversion of prion protein (PrPC) from its normal conformation to an aggregated, PrP-scrapie (PrPSc) isoform. Alteration of iron homeostasis is believed to result from impaired function of PrPC in neuronal iron uptake via its ferrireductase activity. However, unequivocal evidence supporting the ferrireductase activity of PrPC is lacking. Kidney provides a relevant model for this evaluation because PrPC is expressed in the kidney, and ∼370 μg of iron are reabsorbed daily from the glomerular filtrate by kidney proximal tubule cells (PT), requiring ferrireductase activity. Here, we report that PrPC promotes the uptake of transferrin (Tf) and non-Tf-bound iron (NTBI) by the kidney in vivo and mainly NTBI by PT cells in vitro. Thus, uptake of 59Fe administered by gastric gavage, intravenously, or intraperitoneally was significantly lower in PrP-knock-out (PrP−/−) mouse kidney relative to PrP+/+ controls. Selective in vivo radiolabeling of plasma NTBI with 59Fe revealed similar results. Expression of exogenous PrPC in immortalized PT cells showed localization on the plasma membrane and intracellular vesicles and increased transepithelial transport of 59Fe-NTBI and to a smaller extent 59Fe-Tf from the apical to the basolateral domain. Notably, the ferrireductase-deficient mutant of PrP (PrPΔ51–89) lacked this activity. Furthermore, excess NTBI and hemin caused aggregation of PrPC to a detergent-insoluble form, limiting iron uptake. Together, these observations suggest that PrPC promotes retrieval of iron from the glomerular filtrate via its ferrireductase activity and modulates kidney iron metabolism. 相似文献
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Male rats (Rattus novergicus) infected with protozoan Toxoplasma gondii relinquish their innate aversion to the cat odours. This behavioural change is postulated to increase transmission of the parasite to its definitive felid hosts. Here, we show that the Toxoplasma gondii infection institutes an epigenetic change in the DNA methylation of the arginine vasopressin promoter in the medial amygdala of male rats. Infected animals exhibit hypomethylation of arginine vasopressin promoter, leading to greater expression of this nonapeptide. The infection also results in the greater activation of the vasopressinergic neurons after exposure to the cat odour. Furthermore, we show that loss of fear in the infected animals can be rescued by the systemic hypermethylation and recapitulated by directed hypomethylation in the medial amygdala. These results demonstrate an epigenetic proximate mechanism underlying the extended phenotype in the Rattus novergicus–Toxoplasma gondii association. 相似文献
26.
Methylmercury toxicity: amelioration by selenium and water‐soluble chelators as N‐acetyl cysteine and dithiothreitol 下载免费PDF全文
Deepmala Joshi Deepak Kumar Mittal Sangeeta Shukla Ajai Kumar Srivastav Sunil Kumar Srivastav 《Cell biochemistry and function》2014,32(4):351-360
The protective potential of chelators, i.e. N‐acetyl cysteine (0.6 mg /kg, intraperitoneally) and dithiothreitol (15.4 mg kg?1, intraperitoneally) with selenium (0.5 mg kg?1, pre‐oral) were evaluated individually and in combination against methylmercury‐induced biochemical alterations and oxidative stress consequences. Forty‐two male Sprague–Dawley rats were exposed with methylmercury (1.5 mg kg?1, pre‐oral) daily for 21 days followed by different treatments for five consecutive days. Administration of methylmercury caused significant enhancement in the release of transaminases, alkaline phosphatases and lactate dehydrogenases in serum. A significant increased was observed in lipid peroxidation level with a concomitant decreased in glutathione content after methylmercury exposure in liver, kidney and brain. Hepatic microsomal drug metabolizing enzymes (aniline hydroxylase and amidopyrine N‐demethylase) of cytochrome p4502E1 showed sharp depletion after methylmercury exposure. Alterations in histological changes in liver, kidney and brain were also noted in methylmercury administered group. All treated groups showed recovery pattern, but the combined treatments with N‐acetyl cysteine and dithiothreitol in combination with selenium were more effective than that with either alone treatments in recovering blood biochemical changes after methylmercury toxicity. In conclusion, the results demonstrated that combination therapy may recover all blood biochemical alterations and offer maximum protection against methylmercury‐induced toxicity. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
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Jaina S. Patel Manisha M. Patel Prakash G. Koringa Tejas M. Shah Amrutlal K. Patel Ajai K. Tripathi Anila Mathew Mohan M. Rajapurkar Chaitanya G. Joshi 《Indian journal of human genetics》2013,19(2):219-232
BACKGROUND:
Human leukocyte antigen (HLA) is comprised of a highly polymorphic set of genes which determines the histocompatibility of organ transplantation. The present study was undertaken to identify HLA class I and class II allele, genotype and haplotype frequencies in renal transplant recipients and donors from West Central India.MATERIALS AND METHODS:
HLA typing was carried out using Polymerase Chain Reaction-Sequence Specific Primer in 552 live related and unrelated renal transplant recipients and donors.RESULTS:
The most frequent HLA class I and class II alleles and their frequencies in recipients were HLA-AFNx0101 (0.1685) and AFNx0102 (0.1649), HLA-BFNx0135 (0.1322), and HLA-DR beta 1 (DRB 1)FNx0115 (0.2192), whereas in donors, these were HLA-AFNx0102 (0.1848) and AFNx0101 (0.1667), HLA-BFNx0135 (0.1359), and HLA-DRB1FNx0115 (0.2409). The two-locus haplotype statistical analysis revealed HLA-AFNx0102-B61 as the most common haplotype with the frequency of 0.0487 and 0.0510 in recipients and donors, respectively. Further, among the three locus haplotypes HLA-AFNx0133-BFNx0144-DRB1FNx0107 and HLA-AFNx0102-BFNx0161-DRB1FNx0115 were the most common haplotypes with frequencies 0.0362 and 0.0326, respectively in recipients and 0.0236 and 0.0323, respectively in donors. Genotype frequency revealed a high prevalence of genotype HLA-AFNx0102/AFNx0124 in recipients (0.058) compared to donors (0.0109) whereas low prevalence of HLA-AFNx0101/AFNx0102 in recipients (0.0435) than in donors (0.0797). The phylogenetic and principal component analysis of HLA allele and haplotype frequency distribution revealed genetic similarities of various ethnic groups. Further, case control analysis provides preliminary evidence of association of HLA-A genotype (P < 0.05) with renal failure.CONCLUSION:
This study will be helpful in suitable donor search besides providing valuable information for population genetics and HLA disease association analysis. 相似文献28.
Summary Spontaneous temperature sensitive (ts) mutants of cyanophage LPP-1 were isolated from the wild population of the virus upto a frequency of 1.7x10-3. The reversion frequencies were 1.3x10-4 or even less which appeared to be a clonal property. A detailed investigation of the two mutants showed that they were unable to grow at non-permissive temperature and the temperature sensitive phase lasted for 2–3 h during their intracellular growth as judged by the shift-up and down experiments. The mutants differed from the wild phage in being more sensitive to photodynamic inactivation and EDTA shock. They showed high frequency towards rapid lysis mutation following exposure of free phage particles to high temperature. 相似文献
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Niraj Rai Gyaneshwer Chaubey Rakesh Tamang Ajai Kumar Pathak Vipin Kumar Singh Monika Karmin Manvendra Singh Deepa Selvi Rani Sharath Anugula Brijesh Kumar Yadav Ashish Singh Ramkumar Srinivasagan Anita Yadav Manju Kashyap Sapna Narvariya Alla G. Reddy George van Driem Peter A. Underhill Richard Villems Toomas Kivisild Lalji Singh Kumarasamy Thangaraj 《PloS one》2012,7(11)
Linguistic and genetic studies on Roma populations inhabited in Europe have unequivocally traced these populations to the Indian subcontinent. However, the exact parental population group and time of the out-of-India dispersal have remained disputed. In the absence of archaeological records and with only scanty historical documentation of the Roma, comparative linguistic studies were the first to identify their Indian origin. Recently, molecular studies on the basis of disease-causing mutations and haploid DNA markers (i.e. mtDNA and Y-chromosome) supported the linguistic view. The presence of Indian-specific Y-chromosome haplogroup H1a1a-M82 and mtDNA haplogroups M5a1, M18 and M35b among Roma has corroborated that their South Asian origins and later admixture with Near Eastern and European populations. However, previous studies have left unanswered questions about the exact parental population groups in South Asia. Here we present a detailed phylogeographical study of Y-chromosomal haplogroup H1a1a-M82 in a data set of more than 10,000 global samples to discern a more precise ancestral source of European Romani populations. The phylogeographical patterns and diversity estimates indicate an early origin of this haplogroup in the Indian subcontinent and its further expansion to other regions. Tellingly, the short tandem repeat (STR) based network of H1a1a-M82 lineages displayed the closest connection of Romani haplotypes with the traditional scheduled caste and scheduled tribe population groups of northwestern India. 相似文献