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排序方式: 共有763条查询结果,搜索用时 15 毫秒
101.
102.
McArthur S Siddique ZL Christian HC Capone G Theogaraj E John CD Smith SF Morris JF Buckingham JC Gillies GE 《Endocrinology》2006,147(4):1904-1915
This study aimed to test the hypothesis that the tuberoinfundibular dopaminergic neurons of the arcuate nucleus and/or the lactotroph cells of the anterior pituitary gland are key targets for the programming effects of perinatal glucocorticoids (GCs). Dexamethasone was administered noninvasively to fetal or neonatal rats via the mothers' drinking water (1 mug/ml) on embryonic d 16-19 or neonatal d 1-7, and control animals received normal drinking water. At 68 d of age, the numbers of tyrosine hydroxylase-positive (TH+) cells in the arcuate nucleus and morphometric parameters of pituitary lactotrophs were analyzed. In control animals, striking sex differences in TH+ cell numbers, lactotroph cell size, and pituitary prolactin content were observed. Both pre- and neonatal GC treatment regimens were without effect in adult male rats, but in females, the overriding effect was to abolish the sex differences by reducing arcuate TH+ cell numbers (pre- and neonatal treatments) and reducing lactotroph cell size and pituitary prolactin content (prenatal treatment only) without changing lactotroph cell numbers. Changes in circulating prolactin levels represented a net effect of hypothalamic and pituitary alterations that exhibited independent critical windows of susceptibility to perinatal GC treatments. The dopaminergic neurons of the hypothalamic periventricular nucleus and the pituitary somatotroph populations were not significantly affected by either treatment regimen in either sex. These data show that the adult female hypothalamo-lactotroph axis is profoundly affected by perinatal exposure to GCs, which disrupts the tonic inhibitory tuberoinfundibular dopaminergic pathway and changes lactotroph morphology and prolactin levels in the pituitary and circulation. These findings provide new evidence for a long-term disruption in prolactin-dependent homeostasis in females, but not males, after inappropriate GC exposure in perinatal life. 相似文献
103.
Parkinson's disease (PD), a common neurodegenerative disease, is characterized by the progressive loss of dopamine neurons and the accumulation of Lewy bodies and neurites. The exact role of genetic and environmental factors in the pathogenesis of PD has frequently been debated. The association of MPTP (methyl-4-phenyl-1, 2, 3, 6- tetrahydropyridine) and toxins (such as rotenone) with parkinsonism highlights the potential etiologic role of environmental toxins in disease causation. The recent discoveries of monogenic (such as α-synuclein, Parkin, UCHL1, PINK1, DJ-1, LRRK2) forms of PD have provided considerable insights into its pathophysiology. Parkin, an ubiquitin protein ligase assists in the degradation of toxic substrates via the ubiquitin proteasome system. It can also mediate a nondegradative form of ubiquitination. PINK1 and LRRK2 are possibly involved in the phosphorylation of substrates important for various cellular functions. Some toxins could interact with α-synuclein, an endogenous protein that is implicated in pathology of PD. Increasing in vitro and in vivo studies suggest that deficits in mitochondrial function, oxidative and nitrosative stress, the accumulation of aberrant or misfolded proteins, and ubiquitin-proteasome system dysfunction underpin the pathogenesis of sporadic and familial forms of PD. Elucidation of the functions of the proteins encoded by the diseasecausing genes will provide an opportunity for identification of specific pathways that could be targeted in neurotherapeutics. 相似文献
104.
Myrica nagi Hook (syn. Myrica esculenta Buch. & Ham) (Myricaceae) is commonly known as box berry. The bark of Myrica nagi is used in the treatment of mental illness by different ethnic groups of the rural region of Orissa (India). In the present work, the anxiolytic and antidepressant effects of an ethanol extract of M. nagi were analyzed at three different dosages (100, 200, and 400 mg/kg, p.o.) by elevated plus-maze, light/dark exploration test, tail suspension test, and the forced swimming model. Oral administration of the ethanol extract (100, 200, and 400 mg/kg, p.o.) of M. nagi showed significant (p < 0.01) and dose-dependent anxiolytic activity by increasing time spent in the open arms of the elevated plus-maze and in the lit box indicating an anxiolytic effect. Nevertheless this treatment was unable to exhibit an effect identical to antidepressants in the tail suspension and forced swimming tests. Altogether, these results suggest an anxiolytic effect of the ethanol extract of M. nagi. 相似文献
105.
AIM: To evaluate the effect of Ocimum sanctum leaf extract on the dietary supplementation in the transgenic Drosophila model of Parkinson's disease. METHOD: The effect of Ocimum sanctum leaf extract was studied on the transgenic Drosophila model of flies expressing normal human alpha synuclein(h-αs) in the neurons. O. sanctum extract at final concentrations of 0.042 8 × 10-4, 0.87 × 10-4, and 1.85 × 10-4 g·mL-1 of diet were established and the flies were allowed to feed for 21 days. The climbing assay and lipid peroxidation were taken as parameters for the study. RESULTS: The supplementation of O. sanctum extract showed a dose-dependent significant delay in the loss of climbing ability and reduction in oxidative stress in the brain of PD model flies. CONCLUSION: The results of the present study showed that the O. sanctum extract is potent in reducing the PD symptoms in transgenic Drosophila model. 相似文献
106.
Siddique HR Sharma A Gupta SC Murthy RC Dhawan A Saxena DK Chowdhuri DK 《Environmental and molecular mutagenesis》2008,49(3):206-216
Genomic stability requires that error-free genetic information be transmitted from generation to generation, a process that is dependent upon efficient DNA repair. Industrial leachates which contain mixtures of diverse chemicals are a major environmental concern. The interaction between these chemicals may have synergistic, antagonistic, or simply additive effects on biological systems. In the present study, the Comet assay was used to measure the DNA damage produced by leachates of solid wastes from flashlight battery, pigment, and tanning factories in the midgut cells and brain ganglia of Drosophila melanogaster mutants deficient in DNA repair proteins. Larvae were allowed to feed for 48 or 72 hr on diets containing 0.1, 0.5, and 2.0% (v/v) of the leachates. Physicochemical analysis run on the solid wastes, leachates, and treated larvae detected elevated levels of heavy metals. Leachates produced significantly greater levels of DNA damage in mutant strains mei41 (deficient in cell cycle check point protein), mus201 (deficient in excision repair protein), mus308 (deficient in postreplication repair protein), and rad54 (deficient in double strand break repair protein) than in the OregonR(+) wild-type strain. Larvae of the ligaseIV mutant (deficient in double strand break repair protein) were hypersensitive only to the pigment plant waste leachate. Conversely, the dnase2 mutant (deficient in protein responsible for degrading fragmented DNA) was more sensitive to DNA damage induction from the flashlight battery and tannery waste leachates. Our data demonstrate that repair of DNA damage in organisms exposed to leachates is dependent upon several DNA repair proteins, indicative of the involvement of multiple overlapping repair pathways. The study further suggests the usefulness of the Comet assay for studying the mechanisms of DNA repair in Drosophila. 相似文献
107.
Abbas MA Spackman E Fouchier R Smith D Ahmed Z Siddique N Sarmento L Naeem K McKinley ET Hameed A Rehmani S Swayne DE 《Vaccine》2011,29(43):7424-7429
Vaccination has been a critical tool in the control of some avian influenza viruses (AIV) and has been used routinely in Pakistan to help control sporadic outbreaks of highly pathogenic (HP) H7 AIV since 1995. During that time, several AIV isolates were utilized as inactivated vaccines with varying degrees of success. In order to evaluate which H7 AIV strains may serve as optimal vaccines for diverse H7 AIVs from Pakistan we conducted vaccination-challenge studies with five H7 vaccines against challenge with two HPAIVs: A/chicken/Murree/NARC-1/1995 H7N3 and A/chicken/Karachi/SPVC-4/2004 H7N3. To further characterize the isolates antigenic cartography was used to visually demonstrate the antigenic relationships among the isolates. All vaccines provided similar protection against mortality, morbidity and shedding of challenge virus from the respiratory tract. However, some minor (not statistically significant) differences were observed and correlated with antibody levels induced by the vaccine prior to challenge. 相似文献
108.
Edward Fletcher Alan Askari Yunfei Yang Samuel Adegbola Yasser Al‐Obudi Darryl Bernstein Krasha Patel Amit Gupta Omar Abbasi Hasna Anda Harjot Birdi Mohammed Rabie Shahla Siddique Hesham El‐Hakim Chelise Currow Alice Rudge Mohamed Aly Paul Cathcart Stephen Crockett Michael Ha Medhat Aker Ketan Dhatariya 《International journal of clinical practice》2020,74(4)
109.
Efaza U. Siddiqui Timothy P. Murphy Syed S. Naeem Ayesha Siddique Gregory E. McEnteggart Roberto Scarpioni 《Journal of vascular and interventional radiology : JVIR》2018,29(7):966-970
Purpose
To perform a post-hoc analysis of the Nephropathy Ischemic Therapy (NITER) trial, which enrolled patients with atherosclerotic renal artery stenosis, to evaluate whether medical therapy plus stent placement is superior to medical therapy alone in patients without elevated albuminuria.Materials and Methods
Data from 51 patients were analyzed and stratified into 2 cohorts by median urinary albumin (UAlb) levels: cohort 1 (“low albuminuria,” UAlb ≤0.04 g/24h) and cohort 2 (“high albuminuria,” UAlb >0.04g/24h). Interaction effect between treatment arms and UAlb cohorts was calculated using Cox regression analysis. Survival analysis was followed by test for effect size, power analysis, and construction of a Kaplan-Meier survival table.Results
At study completion, 13 patients had an outcome event: 6 (23%) from cohort 1 and 7 (28%) from cohort 2. Patients in cohort 1 had event-free survival of 83% at 3.9 ± 0.3 years from the primary endpoints of all-cause mortality, dialysis, and cardiovascular events when treated with interventional therapy, compared to 45% when treated with medical therapy alone (P = .501), which showed a 62% treatment effect for stent placement. In cohort 2, event-free survival rates were 64% for medical therapy versus 52% for medical plus interventional therapy (P = .64). Using Cox regression analysis, the interaction effect between treatment arms and UAlb cohorts was not significant (P = .32). The power of the study to detect an interaction effect, if one existed, was only 15%.Conclusions
Inference cannot be drawn for similar populations because of inadequate sample size, but, in this sample, patients treated with stent placement who had low albuminuria had better outcomes than patients treated with medical therapy alone. 相似文献110.
Rabbia Tariq Khan Ayesha Siddique Naeem Shahid Samina Khokher Warda Fatima 《Breast cancer (Tokyo, Japan)》2018,25(3):350-355