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101.
In vitro culture of bovine preantral follicles 总被引:3,自引:0,他引:3
Bovine preantral follicles (40-100 microm diameter at collection) were collected from ovaries of slaughtered cows and cultured in vitro with one of the four treatments: follicle stimulating hormone (FSH; 100 ng/ml) alone; FSH plus epidermal growth factor (EGF; 100 ng/ml); FSH plus insulin-transferrin-selenium (ITS; +1%) or FSH plus hypoxanthine (4 mM) in tissue culture medium (TCM 199) supplemented with 10% fetal calf serum (FCS), 0.1 mg/ml sodium pyruvate, 100 IU/ml of penicillin and 100 microg/ml streptomycin. The control culture medium was TCM 199 with supplements without any treatments. Follicles of each size were cultured separately in groups of one to three in 24-well multidishes each containing 500 microl of the appropriate culture medium. Culture commenced at follicle recovery (day 1) and continued for 10 days (harvested on day 11). In each case, half the medium was removed and replaced by fresh medium every third day. Follicle diameters were recorded on days 1, 5 and 11 of the experiment. At the end of the 10-day culture period, half of the follicles were stained with trypan blue to assess their potential viability and half were stained with bisbenzimide plus propidium iodine to estimate various morphological features of the follicles. Follicles of all initial sizes, on all culture treatments, increased in diameter during in vitro cultures with the greatest increases, both in absolute and proportional size, occurring between days 1 and 5 of culture. All of the culture medium supplements caused greater increases in follicle diameters than control medium at both days 5 and 11 of culture for all initial sizes of follicles (p<0.01). The most effective culture supplements for follicles of 40-, 60- and 80-microm initial diameter were FSH alone and FSH+EGF. The size of these follicles at both days 5 and 11 of culture on both the treatments was significantly larger (p<0.01) than follicles cultured in the presence of the other two supplementary treatments. The growth of follicles of 100-microm initial diameter did not differ between culture medium supplements. None of the culture media caused follicle size to increase to the initial diameters of the next larger size category during the 10 days of culture although follicles of 100-microm diameter achieved a diameter of 120 microm, after 4 days of culture.The overall follicular viability and morphology were better with treatments than the controls in all cases; however, there was no significant difference (p>0.05) among them.From this experiment, FSH and FSH plus EGF may be recommended for in vitro culture of smaller (40, 60 and 80 microm) follicles. 相似文献
102.
Global gene expression analysis using microarrays and, more recently, RNA-seq, has allowed investigators to understand biological processes at a system level. However, the identification of differentially expressed genes in experiments with small sample size, high dimensionality, and high variance remains challenging, limiting the usability of these tens of thousands of publicly available, and possibly many more unpublished, gene expression datasets. We propose a novel variable selection algorithm for ultra-low-n microarray studies using generalized linear model-based variable selection with a penalized binomial regression algorithm called penalized Euclidean distance (PED). Our method uses PED to build a classifier on the experimental data to rank genes by importance. In place of cross-validation, which is required by most similar methods but not reliable for experiments with small sample size, we use a simulation-based approach to additively build a list of differentially expressed genes from the rank-ordered list. Our simulation-based approach maintains a low false discovery rate while maximizing the number of differentially expressed genes identified, a feature critical for downstream pathway analysis. We apply our method to microarray data from an experiment perturbing the Notch signaling pathway in Xenopus laevis embryos. This dataset was chosen because it showed very little differential expression according to limma, a powerful and widely-used method for microarray analysis. Our method was able to detect a significant number of differentially expressed genes in this dataset and suggest future directions for investigation. Our method is easily adaptable for analysis of data from RNA-seq and other global expression experiments with low sample size and high dimensionality. 相似文献
103.
104.
Neelakshi Sarkar Ananya Pal Dipanwita Das Debraj Saha Avik Biswas Bhaswati Bandopadhayay Mandira Chakraborti Mrinmoy Ghosh Runu Chakravarty 《PloS one》2015,10(11)
Hepatitis B Virus (HBV) manifests high genetic variability and is classifiable into ten genotypes (A-J). HBV infection can lead to variable clinical outcomes, ranging from self-limiting acute hepatitis to active chronic hepatitis, cirrhosis and hepatocellular carcinoma. The present study characterizes HBV strains circulating among patients with acute (AHB) and chronic HBV infection (CHB). Among a total of 653 HBsAg positive cases, 40 manifested acute infection. After sequencing the surface(S), basal core promoter/pre-core(BCP/PC) and the X gene regions, phylogenetic tree was constructed using MEGA4 by neighbor-joining method. Statistical robustness was established with bootstrap analysis. Nucleotide diversity was determined by Shannon entropy per site using the Entropy program of the Los Alamos National Laboratories. Analyses of acute patients revealed that HBV/D2 is the major circulating sub-genotype and commonly associated with sexual promiscuity and the age group between15-30 years. Comparison of AHB and CHB patients revealed that HBeAg positivity, ALT levels and genotype D were significantly high in AHB, whereas CHB patients were predominantly male, had a high viral load, and were commonly associated with genotype C. The frequencies of mutations in the S, BCP/PC, and X gene were low in AHB as compared to CHB. Drug resistant mutations were not detectable in the polymerase gene of AHB. Average nucleotide diversity in AHB was considerably low as compared to CHB. Further, the highest average ΔH (average difference in entropy between chronic and acute infection) was observed in the BCP/PC region implying that this region was most vulnerable to mutations upon HBV persistence, especially in case of genotype C. Additionally, among all substitutions, the A1762T and G1764A BCP mutations were the strongest indicators of chronicity. In conclusion, the study exhibits a general portrait of HBV strains circulating among acute hepatitis B patients in Eastern India and their intricate differences with chronic patients which should be useful from the clinical point of view. 相似文献
105.
Laura Dyer Pamela Lockyer Yaxu Wu Arnab Saha Chelsea Cyr Martin Moser Xinchun Pi Cam Patterson 《PloS one》2015,10(9)
Formation of the cardiac valves is an essential component of cardiovascular development. Consistent with the role of the bone morphogenetic protein (BMP) signaling pathway in cardiac valve formation, embryos that are deficient for the BMP regulator BMPER (BMP-binding endothelial regulator) display the cardiac valve anomaly mitral valve prolapse. However, how BMPER deficiency leads to this defect is unknown. Based on its expression pattern in the developing cardiac cushions, we hypothesized that BMPER regulates BMP2-mediated signaling, leading to fine-tuned epithelial-mesenchymal transition (EMT) and extracellular matrix deposition. In the BMPER-/- embryo, EMT is dysregulated in the atrioventricular and outflow tract cushions compared with their wild-type counterparts, as indicated by a significant increase of Sox9-positive cells during cushion formation. However, proliferation is not impaired in the developing BMPER-/- valves. In vitro data show that BMPER directly binds BMP2. In cultured endothelial cells, BMPER blocks BMP2-induced Smad activation in a dose-dependent manner. In addition, BMP2 increases the Sox9 protein level, and this increase is inhibited by co-treatment with BMPER. Consistently, in the BMPER-/- embryos, semi-quantitative analysis of Smad activation shows that the canonical BMP pathway is significantly more active in the atrioventricular cushions during EMT. These results indicate that BMPER negatively regulates BMP-induced Smad and Sox9 activity during valve development. Together, these results identify BMPER as a regulator of BMP2-induced cardiac valve development and will contribute to our understanding of valvular defects. 相似文献
106.
Kamala Mitra Abhisek Brata Ghosh Arpita Sarkar Namrata Saha Amit Kumar Dutta 《Biochemical and biophysical research communications》2014
This article reports simple, green and efficient synthesis of γ-Fe2O3 nanoparticles (NPs) (maghemite) through single-source precursor approach for colorimetric estimation of human glucose level. The γ-Fe2O3 NPs, having cubic morphology with an average particle size of 30 nm, exhibited effective peroxidase-like activity through the catalytic oxidation of peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2 producing a blue-colored solution. On the basis of this colored-reaction, we have developed a simple, cheap, highly sensitive and selective colorimetric method for estimation of glucose using γ-Fe2O3/TMB/glucose–glucose oxidase (GOx) system in the linear range from 1 to 80 μM with detection limit of 0.21 μM. The proposed glucose sensor displays faster response, good stability, reproducibility and anti-interference ability. Based on this simple reaction process, human blood and urine glucose level can be monitored conveniently. 相似文献
107.
Lactobacillus intermedius NRRL B-3693 produced mannitol, lactic acid, and acetic acid when grown on fructose at 37°C. The optimal pH for mannitol production
from fructose by the heterofermentative lactic acid bacterium (LAB) in pH-controlled fermentation was at pH 5.0. It produced
160.7 ± 1.1 g mannitol in 40 h with a volumetric productivity of 4.0 g l−1 h−1 in a simplified medium containing 250 g fructose, 50 g corn steep liquor (CSL), and 33 mg MnSO4 per liter. However, the mannitol production by the LAB was severely affected by the variability of CSL. The supplementation
of CSL with soy peptone (5 g/l), tryptophan (50 mg/l), tryptophan (50 mg/l) plus tyrosine (50 mg/l), or commercial protease
preparation (2 ml/100 g of CSL) enhanced the performance of the inferior CSL and thus helped to overcome the nutrient limitations. 相似文献
108.
Wetlands such as rice fields and associated canals are congenial habitats for different fishes and provide the foundation of rice‐fish culture. The selection of suitable fish species determines the success for this linkage of aquaculture and agriculture. An assessment of fish assemblages in selected rice fields and associated canals in West Bengal, India documented the candidate species for culture and conservation in rice fields. Indigenous minnow traps made of bamboo were employed in the rice fields and canals for a period of 3 months, to collect and record the fish abundance. A total of 531 fishes representing 19 different species were caught from the rice fields in 30 sampling efforts. From the canals, 13 different fish species totaling 676 fishes were collected in 80 sampling efforts. The fish collected per trap in the rice fields (mean 17.7 ± 1.97 SE) remained significantly different (t = 4.461, df = 112; P < 0.001) from those of the canals (mean 8.05 ± 1.09 SE). Diversity indices ranged between 1.91 and 2.01, with a 53% similarity between the rice fields and canals. Among the fish species collected, Badis badis, Colisa fasciatus and C. lalia exhibited high abundance; the two species Heteropneustes fossilis and Mystus vittatus established as threatened fish categories, showed low abundance. The fish species collected were important as food resources and the ornamental fish trade, and many of them bear potential in regulating mosquitoes in the rice fields. These fish assemblages in the rice fields and associated canals suggest a rice‐fish culture potential for integrating food and health. 相似文献
109.
Unusual fungal agents that exist environmentally as saprophytes can often lead to opportunistic infections. Hyalohyphomycosis
is a group of fungal infections caused by fungi characterized by hyaline septate hyphae and can infect both immunocompetent
as well as immunocompromised patients. Many a times it becomes difficult to distinguish a pathogenic and a contaminant fungus,
because many such agents can assume clinical significance depending on circumstances. Subcutaneous and invasive fungal infection
due to the emerging hyalohyphomycotic fungus, Acremonium, has drawn the attention of clinicians and microbiologists, as a potential pathogen in patients with and without underlying
risk factors. Generally considered to be minimally invasive in the past, genus Acremonium has been responsible for eumycotic mycetomas and focal infections in otherwise healthy individuals. It has also been increasingly
implicated in systemic fungal diseases. The management with different antifungals in various clinical situations has been
very conflicting and hence needs to be carefully evaluated. This overview is an endeavor to consolidate the available clinical
infections due to Acremonium and the recommendations on treatment. 相似文献
110.
Population dynamics of five different species of grasshopper were analyzed for the first time in Darjeeling (Lebong and Happy Valley) of the eastern Himalayan region of India. The study is based on the relationship between monthly samples collected using sweep nets for three years (March, 2005 to February, 2008) in relation to meteorological parameters (monthly average rainfall, monthly mean maximum and minimum temperatures). The population for each of the five species of grasshopper is plotted against the Aridity Ratio (A.R.). For all species, the population increases at lower A.R. values and then decreases exponentially at higher A.R. values. The exponentially decreasing part of the population is modeled using a simple formula. The monthly population of A. crenulata nymphs and adults in Lebong has also been modeled by iterative equations using A.R. and results compared satisfactorily with the sample data. These works show the possibility of forecasting grasshopper populations using a simple model and thereby easing the regulation process. 相似文献