排序方式: 共有65条查询结果,搜索用时 0 毫秒
21.
Maria E. Laucho-Contreras Katherine L. Taylor Ravi Mahadeva Steve S. Boukedes Caroline A. Owen 《Journal of visualized experiments : JoVE》2015,(95)
COPD is projected to be the third most common cause of mortality world-wide by 2020(1). Animal models of COPD are used to identify molecules that contribute to the disease process and to test the efficacy of novel therapies for COPD. Researchers use a number of models of COPD employing different species including rodents, guinea-pigs, rabbits, and dogs(2). However, the most widely-used model is that in which mice are exposed to cigarette smoke. Mice are an especially useful species in which to model COPD because their genome can readily be manipulated to generate animals that are either deficient in, or over-express individual proteins. Studies of gene-targeted mice that have been exposed to cigarette smoke have provided valuable information about the contributions of individual molecules to different lung pathologies in COPD(3-5). Most studies have focused on pathways involved in emphysema development which contributes to the airflow obstruction that is characteristic of COPD. However, small airway fibrosis also contributes significantly to airflow obstruction in human COPD patients(6), but much less is known about the pathogenesis of this lesion in smoke-exposed animals. To address this knowledge gap, this protocol quantifies both emphysema development and small airway fibrosis in smoke-exposed mice. This protocol exposes mice to CS using a whole-body exposure technique, then measures respiratory mechanics in the mice, inflates the lungs of mice to a standard pressure, and fixes the lungs in formalin. The researcher then stains the lung sections with either Gill’s stain to measure the mean alveolar chord length (as a readout of emphysema severity) or Masson’s trichrome stain to measure deposition of extracellular matrix (ECM) proteins around small airways (as a readout of small airway fibrosis). Studies of the effects of molecular pathways on both of these lung pathologies will lead to a better understanding of the pathogenesis of COPD. 相似文献
22.
Mei-Ling Sharon Tai Norbelinda Norhatta Khean Jin Goh Foong Ming Moy Ramanujam Sujarita Azman Ahmad Asraff Qin Zhi Lee Jiun Hoong Ng Eugene Choon Li Tan Sanjiv Mahadeva 《PloS one》2015,10(1)
Background
Dyspepsia and headache frequently co-exist, but the clinical implication of this association is uncertain. We planned to examine the prevalence and impact of dyspepsia in adults with headache.Methods
A cross-sectional study was conducted in a secondary care setting. Clinical, psychological and health-related quality of life (HRQOL) data were compared between subjects with headache and controls (non-headache subjects). The impact of dyspepsia was analysed further in subjects with headache alone.Results
280 subjects (93 cases with headache and 187 matched controls) were recruited. The following baseline characteristics of subjects were as follows: mean age 45.0±17.3 years, 57.0% females and ethnic distribution—Malaysian = 45 (48.4%), Chinese n = 24 (25.8%) and Indians n = 24 (25.8%). Headache sub-types among cases with headache were as follows: tension-type headache (TTH) n = 53 (57.0%) and migraine n = 40 (43.0%). Dyspepsia was more prevalent in cases with headache compared to controls (25.8% vs 12.8%, p = 0.011), and headache was independently associated with dyspepsia (OR 2.75, 95% CI 1.39–5.43). Among cases with headache, there was a trend towards a higher prevalence of dyspepsia in those with migraine (27.5%) compared to TTH (24.5%). Subjects with headache and dyspepsia, compared to those with headache alone, had a greater severity of headache symptoms (63.67±22.85 mm vs 51.20 ±24.0 mm VAS, p = 0.029). Overall HRQOL scores were lower in headache subjects with dyspepsia (EQ-5D summary score 0.82±0.18 vs 0.90 ±0.16, p = 0.037 and EQ-5D VAS 62.08±17.50 mm vs 72.62 ±18.85 mm, p = 0.018), compared to those without dyspepsia.Conclusion
Dyspepsia is associated with more severe headache symptoms and results in a lower HRQOL in patients with headache. 相似文献23.
The Western Ghats of Karnataka natural ecosystem are among the most diverse and is one of the eight hottest hotspots of biological diversity in the world, that runs along the western part of India through four states including Karnataka. Bacillus thuringiensis (Bt) strains were isolated from soils of Western Ghats of Karnataka and characterized by molecular and analytical methods as a result of which 28 new Bt-like isolates were identified. Bt strains were isolated from soil samples using sodium acetate selection method. The morphology of crystals was studied using light and phase contrast microscopy. Isolates were further characterized for insecticidal cry gene by PCR, composition of toxins in bacterial crystals by SDS-PAGE cloning, sequencing and evaluation of toxicity was done. As a result 28 new Bt-like isolates were identified. Majority of the isolates showed the presence of a 55 kDa protein bands on SDS-PAGE while the rest showed 130, 73, 34, and 25 kDa bands. PCR analysis revealed predominance of Coleopteran-active cry genes in these isolates. The variations in the nucleotide sequences, crystal morphology, and mass of crystal protein(s) purified from the Bt isolates revealed genetic and molecular diversity. Three strains containing Coleopteran-active cry genes showed higher activity against larvae Myllocerus undecimpustulatus undatus Marshall (Coleoptera: Curculionidae) than B. thuringiensis subsp. Morrisoni. Results indicated that Bt isolates could be utilized for bioinsecticide production, aiming to reduce the use of chemical insecticide which could be useful to use in integrated pest management to control agriculturally important pests for sustainable crop production. 相似文献
24.
新疆托木尔峰国家级自然保护区北山羊分布调查 总被引:1,自引:0,他引:1
北山羊作为国家I级保护动物,目前对其研究仍然较少。2004年10—11月、2005年7月以及2005年10—12月三次对新疆托木尔峰国家级自然保护区北山羊(Capraibex)的分布进行调查。通过定点搜寻、样线调查以及访问调查,其结果显示北山羊在保护区5个主要区域中的3个有分布,这3个区域是:琼台兰河谷地区、克其克台兰河谷地区、木扎特河谷地区;在托木尔河谷和库孜巴依河谷两个区域中,定点搜寻和样线调查均没有发现北山羊分布,但访问调查该区域有北山羊。通过此次调查得出托木尔峰自然保护区的大部分地区是北山羊分布区,说明该保护区在北山羊保护中的确起了重要作用,但北山羊在保护区中的不均匀分布现状值得注意,这种现象可能与人为活动干扰有关。 相似文献
25.
Mohankrishna Dalvoy Vasudevarao Pushpak Mizar Sujata Kumari Somnath Mandal Soumik Siddhanta Mahadeva MM Swamy Stephanie Kaypee Ravindra C Kodihalli Amrita Banerjee Chandrabhas Naryana Dipak Dasgupta Tapas K. Kundu 《The Journal of biological chemistry》2014,289(11):7702-7717
Hydroxynaphthoquinone-based inhibitors of the lysine acetyltransferase KAT3B (p300), such as plumbagin, are relatively toxic. Here, we report that free thiol reactivity and redox cycling properties greatly contribute to the toxicity of plumbagin. A reactive 3rd position in the naphthoquinone derivatives is essential for thiol reactivity and enhances redox cycling. Using this clue, we synthesized PTK1, harboring a methyl substitution at the 3rd position of plumbagin. This molecule loses its thiol reactivity completely and its redox cycling ability to a lesser extent. Mechanistically, non-competitive, reversible binding of the inhibitor to the lysine acetyltransferase (KAT) domain of p300 is largely responsible for the acetyltransferase inhibition. Remarkably, the modified inhibitor PTK1 was a nearly non-toxic inhibitor of p300. The present report elucidates the mechanism of acetyltransferase activity inhibition by 1,4-naphthoquinones, which involves redox cycling and nucleophilic adduct formation, and it suggests possible routes of synthesis of the non-toxic inhibitor. 相似文献
26.
Srilatha Rao Sowmyashree A S Gururaj Kudur Jayaprakash M. Mahadeva Swamy Swamynathan K Deepak Kumar 《Luminescence》2023,38(7):1123-1131
This report attempts to elucidate the potential of plant seed extract assisted synthesis of graphite-based zinc oxide nanoparticles (C-ZnO NPs) towards removal of chromium(VI) ions from water samples. The graphite-based zinc oxide (C-ZnO) composites were characterized using thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The C-ZnO nanocomposites have found to remove chromium from the sample through an adsorption process. The sensitivity of chromium removal through adsorption is found to be in the range of 40 to 240 mg. The adsorption behaviour was found to be fitting with Langmuir isotherm model and the adsorption reaction follows pseudo second-order kinetics. 相似文献
27.
Shamsul Mohd Zain Zahurin Mohamed Sanjiv Mahadeva Sanjay Rampal Roma Choudhury Basu Phaik-Leng Cheah Agus Salim Rosmawati Mohamed 《PloS one》2013,8(3)
Angiotensin II type 1 receptor (AGTR1) has been reported to play a fibrogenic role in non-alcoholic fatty liver disease (NAFLD). In this study, five variants of the AGTR1 gene (rs3772622, rs3772627, rs3772630, rs3772633, and rs2276736) were examined for their association with susceptibility to NAFLD. Subjects made up of 144 biopsy-proven NAFLD patients and 198 controls were genotyped using TaqMan assays. The liver biopsy specimens were histologically graded and scored according to the method of Brunt. Single locus analysis in pooled subjects revealed no association between each of the five variants with susceptibility to NAFLD. In the Indian ethnic group, the rs2276736, rs3772630 and rs3772627 appear to be protective against NAFLD (p = 0.010, p = 0.016 and p = 0.026, respectively). Haplotype ACGCA is shown to be protective against NAFLD for the Indian ethnic subgroup (p = 0.03). Gene-gene interaction between the AGTR1 gene and the patatin-like phospholipase domain-containing 3 (PNPLA3) gene, which we previously reported as associated with NAFLD in this sample, showed a strong interaction between AGTR1 (rs3772627), AGTRI (rs3772630) and PNPLA3 (rs738409) polymorphisms on NAFLD susceptibility (p = 0.007). Further analysis of the NAFLD patients revealed that the G allele of the AGTR1 rs3772622 is associated with increased fibrosis score (p = 0.003). This is the first study that replicates an association between AGTR1 polymorphism and NAFLD, with further details in histological features of NAFLD. There is lack of evidence to suggest an association between any of the five variants of the AGTR1 gene and NAFLD in the Malays and Chinese. In the Indians, the rs2276736, rs3772630 and rs3772627 appear to protect against NAFLD. We report novel findings of an association between the G allele of the rs3772622 with occurrence of fibrosis and of the gene-gene interaction between AGTR1gene and the much-studied PNPLA3 gene. 相似文献
28.
29.
Electroporation was used to facilitate transformation of Listeria species with plasmid DNA. Optimal conditions for transformation of L. monocytogenes were a field strength of 8.5 kV/cm, 200 Ohms resistance, 25 microF capacitor with a time constant of 5 ms. With these conditions, 3.9 x 10(6) transformants/micrograms DNA were obtained. Under the same conditions, L. innocua and L. ivanovii exhibited a frequency of transformation similar to that of L. monocytogenes but a somewhat lower level was obtained with L. seeligeri. 相似文献
30.
Summary We have investigated the efficacy of the cell blot assay in analysis of the secretion of hormones and peptides from rat anterior
pituitary cells. The dissociated cells are cultured on pieces of translucent polyvinylidene difluoride membrane, on which
their secretory products are adsorbed and subsequently immunostained. The area and integrated optical density of the stained
‘halo’ surrounding individual cells is measured by microscopical image processing and the values for basal secretion of a
particular hormone or peptide are compared with those after application of secretagogues or inhibitors. Our experiments tested
established responses of dissociated rat anterior pituitary cells; in general, the results were as expected. Double immunoenzymatic
staining could be used to show secretion of two products from the same or different cells in one preparation, and immunofluorescence
with fluorescein- and/or rhodamine-labelled antibodies could be used instead of enzyme-linked immunolabelling. Optimal dilutions
of immunoreagents were much higher than those used for immunocytochemistry on tissue sections. Although the cell blot assay
does not provide absolute quantification, since some of the secreted product escapes into the medium, it is a relatively easy
and economical way for morphologists to compare secretion from individual cells under varying conditions. 相似文献