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21.
Ravi Ranjan Rakesh Kumar Singh Thirupathi Yasotha Manish Kumar Kuldeep Kumar Renu Singh Monzamul Houque Vijay Prakash Mourya Gyanendra Singh Mihir Sarkar Bikash Chandra Das Sadhan Bag 《In vitro cellular & developmental biology. Animal》2013,49(7):486-491
The present study was conducted to see the in vivo developmental potency of caprine parthenogenetic embryos generated in a modified way. The good quality caprine oocytes were matured in presence of cytochalasin B (CCB) and then activated by 7% ethanol followed by 2 mM 6-dimethyl amino purine (6-DMAP) and embryo development was recorded. Early stage parthenogenetic embryos (two to four cells) were surgically transferred in recipients (10). The pregnancy diagnosis was done by nonreturn to oestrus, ultrasonography (USG), and progesterone estimation. The levels of progesterone were above normal values (1 ng/ml) of pregnancy and fall below the level of pregnancy just before retuned to oestrus. Progesterone profile revealed that out of ten recipients (G1–G10), four goats (G1, G2, G3, and G5) returned to oestrus after 43?±?7.29 (Mean?±?SE) d of embryo transfer and six goats (G4, G6, G7, G8, G9, and G10) did not return to cycle even after 70 d of embryo transfer. In three recipients (G4, G5, and G6), the USG on day 40 revealed that there was fluid filled uterine body with solid fetus-like structure. These might be dead fetus and had started resorption. The progesterone profile also corroborated the assumption of pregnancy in these animals. Authors believe that this may be the first report on in vivo diploid parthenogenetic embryo development in caprine species. 相似文献
22.
Hui Chen Bing Zhou Matthew Brecher Nilesh Banavali Susan A. Jones Zhong Li Jing Zhang Dilip Nag Laura D. Kramer Arun K. Ghosh Hongmin Li 《PloS one》2013,8(10)
The methyltransferase enzyme (MTase), which catalyzes the transfer of a methyl group from S-adenosyl-methionine (AdoMet) to viral RNA, and generates S-adenosyl-homocysteine (AdoHcy) as a by-product, is essential for the life cycle of many significant human pathogen flaviviruses. Here we investigated inhibition of the flavivirus MTase by several AdoHcy-derivatives. Unexpectedly we found that AdoHcy itself barely inhibits the flavivirus MTase activities, even at high concentrations. AdoHcy was also shown to not inhibit virus growth in cell-culture. Binding studies confirmed that AdoHcy has a much lower binding affinity for the MTase than either the AdoMet co-factor, or the natural AdoMet analog inhibitor sinefungin (SIN). While AdoMet is a positively charged molecule, SIN is similar to AdoHcy in being uncharged, and only has an additional amine group that can make extra electrostatic contacts with the MTase. Molecular Mechanics Poisson-Boltzmann Sovation Area analysis on AdoHcy and SIN binding to the MTase suggests that the stronger binding of SIN may not be directly due to interactions of this amine group, but due to distributed differences in SIN binding resulting from its presence. The results suggest that better MTase inhibitors could be designed by using SIN as a scaffold rather than AdoHcy. 相似文献
23.
Julie Nemecek Nabanita Nag Christina M. Carlson Jay R. Schneider Dennis M. Heisey Christopher J. Johnson David M. Asher Luisa Gregori 《PloS one》2013,8(10)
Rapid antemortem tests to detect individuals with transmissible spongiform encephalopathies (TSE) would contribute to public health. We investigated a technique known as protein misfolding cyclic amplification (PMCA) to amplify abnormal prion protein (PrPTSE) from highly diluted variant Creutzfeldt-Jakob disease (vCJD)-infected human and macaque brain homogenates, seeking to improve the rapid detection of PrPTSE in tissues and blood. Macaque vCJD PrPTSE did not amplify using normal macaque brain homogenate as substrate (intraspecies PMCA). Next, we tested interspecies PMCA with normal brain homogenate of the southern red-backed vole (RBV), a close relative of the bank vole, seeded with macaque vCJD PrPTSE. The RBV has a natural polymorphism at residue 170 of the PrP-encoding gene (N/N, S/S, and S/N). We investigated the effect of this polymorphism on amplification of human and macaque vCJD PrPTSE. Meadow vole brain (170N/N PrP genotype) was also included in the panel of substrates tested. Both humans and macaques have the same 170S/S PrP genotype. Macaque PrPTSE was best amplified with RBV 170S/S brain, although 170N/N and 170S/N were also competent substrates, while meadow vole brain was a poor substrate. In contrast, human PrPTSE demonstrated a striking narrow selectivity for PMCA substrate and was successfully amplified only with RBV 170S/S brain. These observations suggest that macaque PrPTSE was more permissive than human PrPTSE in selecting the competent RBV substrate. RBV 170S/S brain was used to assess the sensitivity of PMCA with PrPTSE from brains of humans and macaques with vCJD. PrPTSE signals were reproducibly detected by Western blot in dilutions through 10-12 of vCJD-infected 10% brain homogenates. This is the first report showing PrPTSE from vCJD-infected human and macaque brains efficiently amplified with RBV brain as the substrate. Based on our estimates, PMCA showed a sensitivity that might be sufficient to detect PrPTSE in vCJD-infected human and macaque blood. 相似文献
24.
Leelavati Narlikar Nidhi Mehta Sanjeev Galande Mihir Arjunwadkar 《Nucleic acids research》2013,41(3):1416-1424
The structural simplicity and ability to capture serial correlations make Markov models a popular modeling choice in several genomic analyses, such as identification of motifs, genes and regulatory elements. A critical, yet relatively unexplored, issue is the determination of the order of the Markov model. Most biological applications use a predetermined order for all data sets indiscriminately. Here, we show the vast variation in the performance of such applications with the order. To identify the ‘optimal’ order, we investigated two model selection criteria: Akaike information criterion and Bayesian information criterion (BIC). The BIC optimal order delivers the best performance for mammalian phylogeny reconstruction and motif discovery. Importantly, this order is different from orders typically used by many tools, suggesting that a simple additional step determining this order can significantly improve results. Further, we describe a novel classification approach based on BIC optimal Markov models to predict functionality of tissue-specific promoters. Our classifier discriminates between promoters active across 12 different tissues with remarkable accuracy, yielding 3 times the precision expected by chance. Application to the metagenomics problem of identifying the taxum from a short DNA fragment yields accuracies at least as high as the more complex mainstream methodologies, while retaining conceptual and computational simplicity. 相似文献
25.
Kumar Abhiram Jha Tapas C Nag Shashi Wadhwa Tara Sankar Roy 《Journal of biosciences》2016,41(4):667-676
Light causes damage to the retina, which is one of the supposed factors for age-related macular degeneration in human. Some animal species show drastic retinal changes when exposed to intense light (e.g. albino rats). Although birds have a pigmented retina, few reports indicated its susceptibility to light damage. To know how light influences a cone-dominated retina (as is the case with human), we examined the effects of moderate light intensity on the retina of white Leghorn chicks (Gallus g. domesticus). The newly hatched chicks were initially acclimatized at 500 lux for 7 days in 12 h light: 12 h dark cycles (12L:12D). From posthatch day (PH) 8 until PH 30, they were exposed to 2000 lux at 12L:12D, 18L:6D (prolonged light) and 24L:0D (constant light) conditions. The retinas were processed for transmission electron microscopy and the level of expressions of rhodopsin, S- and L/M cone opsins, and synaptic proteins (Synaptophysin and PSD-95) were determined by immunohistochemistry and Western blotting. Rearing in 24L:0D condition caused disorganization of photoreceptor outer segments. Consequently, there were significantly decreased expressions of opsins and synaptic proteins, compared to those seen in 12L:12D and 18L:6D conditions. Also, there were ultrastructural changes in outer and inner plexiform layer (OPL, IPL) of the retinas exposed to 24L:0D condition. Our data indicate that the cone-dominated chick retina is affected in constant light condition, with changes (decreased) in opsin levels. Also, photoreceptor alterations lead to an overall decrease in synaptic protein expressions in OPL and IPL and death of degenerated axonal processes in IPL. 相似文献
26.
Remotely sensed vegetation indices are increasingly being used in wildlife studies but field‐based support for their utility as a measure of forage availability comes largely from open‐canopy habitats. We assessed whether normalized difference vegetation index (NDVI) represents forage availability for Asian elephants in a southern Indian tropical forest. We found that the number of food species was a small percentage of all plant species. NDVI was not a good measure of food abundance in any vegetation category partly because of (a) small to moderate proportional abundances of food species relative to the total abundance of all species in that category (herbs and shrubs), (b) abundant overstory vegetation resulting in low correlations between NDVI and food abundance, despite a high proportional abundance of food species and a concordance between total abundance and food species abundance (graminoids), and (c) the relevant variables measured and important as food at the ground level (count and GBH) not being related to primary productivity (trees and recruits). NDVI had a negative relationship with the total abundance of graminoids, which represent a bulk of elephant and other herbivore diet, because of negative interaction with other vegetation and canopy cover that positively explained NDVI. Spatially interpolated total graminoid abundance modeled from field data outperformed NDVI in predicting total graminoid abundance, although interpolation models of food graminoid abundance were not satisfactory. Our results reject the utility of NDVI in mapping elephant forage abundance in tropical forests, a finding that has implications for studies of other herbivores also. Abstract in Kannada is available with online material. 相似文献
27.
Nocardia asteroides is an important opportunistic pathogen in immunocompromised hosts. The primary infection is usually in the lungs and is followed
by dissemination to other parts of the body. Primary subcutaneous infection with Nocardia asteroides has been reported rarely (three reports) and no such case has been reported in a renal transplant recipient. We describe
here a case of renal transplant recipient who developed primary subcutaneous infection with Nocardia asteroides within one and half years of the transplantation.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
28.
Neogi P Lakner FJ Medicherla S Cheng J Dey D Gowri M Nag B Sharma SD Pickford LB Gross C 《Bioorganic & medicinal chemistry》2003,11(18):4059-4067
A number of 2,4-thiazolidinedione derivatives of -phenyl substituted cinnamic acid were synthesized and studied for their PPAR agonist activity. The E-isomer of cinnamic acid, 11, showed moderate PPAR transactivation. The corresponding Z-isomer, 23, and double bond reduced derivative, 15, were found to be much less potent. Although the E-isomer showed a moderate PPAR gamma transactivation, it demonstrated a strong glucose-lowering effect in a genetic rodent model of diabetes. Results of pharmacokinetic, metabolism and permeability studies are consistent with 11 being an active prodrug with an active metabolite, 14, that has similar glucose lowering and PPAR gamma agonist properties. 相似文献
29.
Using subtractive hybridization screening, the methyl CpG-binding domain containing protein MBD3 was identified as being more prevalently expressed in the embryonic brain than in the adult. In this report, we present the mRNA and protein expression patterns of MBD3 in the developing brain. MBD3 expression was detected in neuroepithelial cells of the developing forebrain, and in peripheral tissues such as liver and intestine during late embryogenesis. This is in contrast to its related family member MBD2, which displayed only minimal expression in the embryonic brain. Immunoblot analysis revealed that the levels of both MBD3 splice forms decrease in the maturing postnatal hippocampus and cortex, although the two forms do not decline at equivalent rates. Immunohistochemical analysis revealed strong MBD3 immunostaining in principal neurons of the hippocampus and cortex, but weak or nondetectable immunostaining in outer cortical layer cells. MBD3 was also selectively expressed in the adult retina, where strong immunoreactivity was detected in cells of the inner nuclear and ganglion cell layers, but no immunoreactivity was detected in cells of the outer nuclear layer. Taken together, these results illustrate that MBD3 displays a selective spatial and temporal pattern of expression in the embryonic and adult brain, thereby strengthening the possibility of MBD3 playing an important role in neuronal development. 相似文献
30.
Intraventricular infusion of rats with beta-amyloid for 14 days resulted in memory deficit in the water maze as well as decreases in choline acetyltransferase activities and somatostatin levels in the cerebral cortex and hippocampus. These changes were not altered by daily intraperitoneal injection of 20 mg/Kg melatonin. Orally administered Ginkgo biloba extract, however, partially reversed the memory deficit and the decrease in choline actyltransferase activities in the hippocampus. The latter treatment failed to reverse the decrease in somatostatin levels. The results indicate that orally administered Ginkgo biloba extract can protect the brain against beta-amyloid from changes leading to memory deficit through its effect on the cholinergic system. 相似文献