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排序方式: 共有260条查询结果,搜索用时 78 毫秒
1.
The effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), its metabolite 1-methyl-4-phenyl pyridinium ion (MPP+, cyperquat) and a structurally-related compound paraquat on mitochondrial functions were investigated in isolated organelles from rat striatum, cortex and liver. MPTP (0.1-1.0 mM) had no significant effect on various parameters of mitochondrial oxidative phosphorylation. In contrast, MPP+ (0.5 mM) inhibited the oxidation of the nicotinamide adenine dinucleotide (NAD+)-linked substrates pyruvate and malate but not that of the flavin adenine dinucleotide (FAD+)-linked substrate succinate. Paraquat (5.0 mM) significantly stimulated basal oxygen consumption (state 4) without influencing the oxygen utilization (state 3) associated with adenosine diphosphate (ADP) phosphorylation. Thus, these structurally-related compounds have different effects on mitochondrial oxidative phosphorylation, but the organelles from striatum, cortex and liver were affected in a similar manner by these compounds. 相似文献
2.
Bloom Syndrome and Maternal Uniparental Disomy for Chromosome 15 总被引:4,自引:1,他引:3
Trevor Woodage Madhuri Prasad Joanne W. Dixon Roslyn E. Selby Dennis R. Romain Letizia M. Columbano-Green David Graham Peter K. Rogan James R. Seip Arabella Smith Ronald J. Trent 《American journal of human genetics》1994,55(1):74-80
Bloom syndrome (BS) is an autosomal recessive disorder characterized by increases in the frequency of sister-chromatid exchange and in the incidence of malignancy. Chromosome-transfer studies have shown the BS locus to map to chromosome 15q. This report describes a subject with features of both BS and Prader-Willi syndrome (PWS). Molecular analysis showed maternal uniparental disomy for chromosome 15. Meiotic recombination between the two disomic chromosomes 15 has resulted in heterodisomy for proximal 15q and isodisomy for distal 15q. In this individual BS is probably due to homozygosity for a gene that is telomeric to D15S95 (15q25), rather than to genetic imprinting, the mechanism responsible for the development of PWS. This report represents the first application of disomy analysis to the regional localization of a disease gene. This strategy promises to be useful in the genetic mapping of other uncommon autosomal recessive conditions. 相似文献
3.
A protocol has been developed to obtain whole plants from apical shoot meristems of red pepper (Capsicum annuum L. cv. Bhivapuri), susceptible to viral infections. The meristems (~ 0.8 mm long), from aseptically grown seedlings (one-month-old), cultured on filter paper bridge in liquid Murashige and Skoog medium supplemented with 2 mg/l benzylaminopurine produced multiple shoots (5–7 per explant). The differentiated shoots developed further upon transfer to agar-solidified medium. Complete plantlets were obtained after rooting of shoots on MS medium fortified with 1 mg/l naphthaleneacetic acid. 相似文献
4.
Summary Two antitubercular drugs, viz., isoniazid (INH) and para-aminosalicylic acid (PAS), in combination, were evaluated for their in vivo clastogenic effects on human lymphocyte chromosomes. Lymphocyte cultures from tuberculosis patients taking a therapeutic dose of INH and PAS for a period of not less then 3 months and from two sets of controls were used: (1) newly diagnosed tuberculosis patients who were not yet under therapy and (2) healthy individuals from the general population. Chromosome aberration frequency was very significantly increased in the patients exposed to combined INH and PAS therapy as compared with controls. The most frequently observed aberrations were chromatid breaks and gaps. Isoniazid, the major antituberculosis drug, has been reported not to be clastogenic by itself. However, we observed that the INH-PAS combination commonly used in therapy was clastogenic. From this observation it may be concluded that INH and PAS act synergistically in producing chromosomal aberrations. 相似文献
5.
Defective guanine uptake in an 8-azaguanine-resistant mutant of Salmonella typhimurium 总被引:4,自引:2,他引:2
An 8-azaguanine-resistant mutant, azg-11, derived from a guanine auxotroph, gua-1, of Salmonella typhimurium was isolated. This mutant was resistant to the analogue when grown on 2,6-diaminopurine, but showed greater susceptibility than the parent on guanine. Studies with the uptake of radioactive purines revealed that the mutant was defective in a mechanism for incorporation of guanine as well as of xanthine. Initial rates of uptake were determined for guanine at concentrations which were sufficiently low to make permeases limiting. The affinity constant K(m) for the mutant was found to be 2.5 x 10(-4)m; that of the parent was 2.3 x 10(-5)m. Examination of cell-free extracts suggested that the purine nucleotide pyrophosphorylases, responsible for the conversion of free intracellular purines to the corresponding nucleotides, were present and unaltered. The results indicate that the mutant is defective in a mechanism for the active transport for guanine and possibly xanthine. 相似文献
6.
Andrew M. Steffensmeier Meghana Tare Oorvashi Roy Puli Rohan Modi Jaison Nainaparampil Madhuri Kango-Singh Amit Singh 《PloS one》2013,8(11)
Alzheimer''s disease (AD, OMIM: 104300), a progressive neurodegenerative disorder with no cure to date, is caused by the generation of amyloid-beta-42 (Aβ42) aggregates that trigger neuronal cell death by unknown mechanism(s). We have developed a transgenic Drosophila eye model where misexpression of human Aβ42 results in AD-like neuropathology in the neural retina. We have identified an apical-basal polarity gene crumbs (crb) as a genetic modifier of Aβ42-mediated-neuropathology. Misexpression of Aβ42 caused upregulation of Crb expression, whereas downregulation of Crb either by RNAi or null allele approach rescued the Aβ42-mediated-neurodegeneration. Co-expression of full length Crb with Aβ42 increased severity of Aβ42-mediated-neurodegeneration, due to three fold induction of cell death in comparison to the wild type. Higher Crb levels affect axonal targeting from the retina to the brain. The structure function analysis identified intracellular domain of Crb to be required for Aβ42-mediated-neurodegeneration. We demonstrate a novel neuroprotective role of Crb in Aβ42-mediated-neurodegeneration. 相似文献
7.
Krishna Kumar Natarajan Amaresan Someshwar Bhagat Kutthum Madhuri Palaniswamy Udhayaraj Ramesh Chandra Srivastava 《Archives Of Phytopathology And Plant Protection》2013,46(14):1399-1409
In this study, the in vitro potential of 42 Trichoderma spp. were evaluated against four isolates of soil borne phytopathogenic fungi viz., Rhizoctonia solani, Macrophomina sp., Sclerotium rolfsii and Pythium aphanidermatum in dual culture techniques and through production of volatile and non-volatile inhibitors. In vitro screening results showed that the proportion of isolates with antagonistic activities was highest for the S. rolfsii followed by R. solani, Macrophomina sp. and P. aphanidermatum, respectively. The isolates TNT1, TNP2 and TWP1 showed consistent results in volatile and non-volatile activity in vitro against any of the two pathogens tested. Based on genomic finger prints, potential isolates showed no particular correlation between the origin of the isolates and the Random Amplified Polymorphic DNA (RAPD) groups could not be established. However, the polymorphism shown by the isolates did not correlate to their level of antagonism. Whereas, in physiology studies using BIOLOG (microbial identification system), three groups were formed, one group consists with 14 different Trichoderma species and two groups with two isolates each comprised of only T. koningii and T. viride. 相似文献
8.
Claire Lugassy Bruno Péault Madhuri Wadehra Hynda K. Kleinman Raymond L. Barnhill 《Pigment cell & melanoma research》2013,26(5):746-754
We hypothesize that the interaction between angiotropic melanoma cells and the abluminal vascular surface can induce or sustain embryonic and/or stem cell migratory properties in these tumor cells. As a result, such angiotropic melanoma cells may migrate along the abluminal vascular surface, demonstrating pericytic mimicry. Through these cellular interactions, melanoma cells may migrate toward secondary sites. 相似文献
9.
Timothy B. Curry Madhuri Somaraju Casey N. Hines Cornelius B. Groenewald John M. Miles Michael J. Joyner Nisha Charkoudian 《Obesity (Silver Spring, Md.)》2013,21(3):480-485
Objective:
This study was designed to determine how gastric bypass affects the sympathetically‐mediated component of resting energy expenditure (REE) and muscle sympathetic nerve activity (MSNA).Design and Methods:
We measured REE before and after beta‐blockade in seventeen female subjects approximately three years post‐gastric bypass surgery and in nineteen female obese individuals for comparison. We also measured MSNA in a subset of these subjects.Results:
The gastric bypass subjects had no change in REE after systemic beta‐blockade, reflecting a lack of sympathetic support of REE, in contrast to obese subjects where REE was reduced by beta‐blockade by approximately 5% (P < 0.05). The gastric bypass subjects, while still overweight (BMI = 29.3 vs 38.0 kg·m?2 for obese subjects, P < 0.05), also had significantly lower MSNA compared to obese subjects (10.9 ± 2.3 vs. 21.9 ± 4.1 bursts·min?1, P < 0.05). The reasons for low MSNA and a lack of sympathetically mediated support of REE after gastric bypass are likely multifactorial and may be related to changes in insulin sensitivity, body composition, and leptin, among other factors.Conclusions:
These findings may have important consequences for the maintenance of weight loss after gastric bypass. Longitudinal studies are needed to further explore the changes in sympathetic support of REE and if changes in MSNA or tissue responsiveness are related to the sympathetic support of REE.10.
Karoline Kragelund Nielsen Peter Damm Anil Kapur Vijayam Balaji Madhuri S. Balaji Veerasamy Seshiah Ib C. Bygbjerg 《PloS one》2016,11(3)