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91.
Increased nitric oxide (NO) is the main factor leading to the hyperdynamic circulation associated with advanced portal hypertension (PHT), but the initial mechanisms and the magnitude of increase in portal pressure required to trigger NO production are not known. We addressed these issues by studying systemic and splanchnic hemodynamics and endothelial NO synthase (eNOS) and VEGF expression in rats with different degrees of portal hypertension. Portal vein ligation (PVL) performed over needles of three different calibers (16-, 18-, and 20-gauge) yielded different degrees of PHT and portosystemic shunting. Compared with sham rats, all three groups of PVL rats exhibited features of hyperdynamic circulation. Rats with minimal portal hypertension (PVL with a 16-gauge needle) showed an early increase in VEGF and eNOS expression selectively at the jejunum. Immunofluorescence showed that VEGF expression was located in highly vascularized areas of the mucosa. Inhibition of VEGF signaling markedly attenuated the increase in eNOS expression. In conclusion, mild increases in portal pressure are enough to upregulate eNOS at the intestinal microcirculation, and this occurs, at least in part, through VEGF upregulation.  相似文献   
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93.
Prion protein gene polymorphisms in four goat breeds of Pakistan   总被引:1,自引:0,他引:1  
Four different goat breeds (Pak-Angora, Dera Din Panah, Naachi and Teddy) of Pakistan were selected to investigate polymorphism in the prion protein gene (PrP gene) responsible for scrapie disease resistance in goats. Initially, genotyping of 187 animals of these four breeds by restriction fragment length polymorphism (RFLP) was done to see the genotype for codon 136 and 154. All the animals were monomorphic with a genotype of AARR except one animal of Teddy breed having the genotype of AARH. Sequencing of PrP gene of twenty animals representing these four goat breeds revealed two genotypes PPSSSS and PPSSPS with haplotypes PSS and PSP of PrP gene at the codon numbers 42, 138, and 240. All four breeds showed both wild type monomorphic sequence and mutant polymorphic sequences of these codons. The mutants of 42 and 138 codons translate the same amino acids as with the wild type sequences, while the mutant of codon 240 is responsible for a different amino acid translation i.e., serine to proline. In short, this study provides preliminary information about alleles and genotypes of PrP gene in four goat breeds of Pakistan.  相似文献   
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95.
Textile industry discharges a vast amount of unused synthetic dyes in effluents. The discharge of these effluents into rivers and lakes leads to a reduction in sunlight penetration in natural water bodies, which, in turn, decreases both photosynthetic activity and dissolved oxygen concentration rendering it toxic to living beings. This paper describes the decolorization potential of a local white rot fungus, Coriolus versicolor IBL-04 for practical industrial effluents collected from five different textile industries of Faisalabad, Pakistan. Screening of C. versicolor IBL-04 on five effluents showed best decolorization results (36.3%) for Arzoo Textile Industry (ART) effluent in 6 days followed by Crescent Textile Industry (CRT), Itmad Textile Industry (ITT), Megna Textile Industry (MGT) and Ayesha Textile Industry (AST) effluents. Optimization of different process parameters for ART effluent decolorization by C. versicolor IBL-04 showed that manganese peroxidase (MnP) (486 U/mL) was the lignolytic enzyme present in the culture filtrates with undetectable lignin peroxidase (LiP) and laccase. The MnP synthesis and effluent decolorization could be enhanced to 725 U/mL and 84.4%, respectively, with a significant time reduction to 3 days by optimizing pH and temperature and using 1% starch as a supplementary carbon source.  相似文献   
96.
The Fascinating World of RNA Interference   总被引:1,自引:0,他引:1       下载免费PDF全文
Micro- and short-interfering RNAs represent small RNA family that are recognized as critical regulatory species across the eukaryotes. Recent high-throughput sequencing have revealed two more hidden players of the cellular small RNA pool. Reported in mammals and Caenorhabditis elegans respectively, these new small RNAs are named piwi-interacting RNAs (piRNAs) and 21U-RNAs. Moreover, small RNAs including miRNAs have been identified in unicellular alga Chlamydomonas reinhardtii, redefining the earlier concept of multi-cellularity restricted presence of these molecules. The discovery of these species of small RNAs has allowed us to understand better the usage of genome and the number of genes present but also have complicated the situation in terms of biochemical attributes and functional genesis of these molecules. Nonetheless, these new pools of knowledge have opened up avenues for unraveling the finer details of the small RNA mediated pathways.  相似文献   
97.
Long‐term potentiation (LTP) and long‐term depression (LTD) are the current models of synaptic plasticity and widely believed to explain how different kinds of memory are stored in different brain regions. Induction of LTP and LTD in different regions of brain undoubtedly involve trafficking of AMPA receptor to and from synapses. Hippocampal LTP involves phosphorylation of GluR1 subunit of AMPA receptor and its delivery to synapse whereas; LTD is the result of dephosphorylation and endocytosis of GluR1 containing AMPA receptor. Conversely the cerebellar LTD is maintained by the phosphorylation of GluR2 which promotes receptor endocytosis while dephosphorylation of GluR2 triggers receptor expression at the cell surface and results in LTP. The interplay of phosphorylation and O‐GlcNAc modification is known as functional switch in many neuronal proteins. In this study it is hypothesized that a same phenomenon underlies as LTD and LTP switching, by predicting the potential of different Ser/Thr residues for phosphorylation, O‐GlcNAc modification and their possible interplay. We suggest the involvement of O‐GlcNAc modification of dephosphorylated GluR1 in maintaining the hippocampal LTD and that of dephosphorylated GluR2 in cerebral LTP. J. Cell. Biochem. 109: 585–597, 2010. © 2010 Wiley‐Liss, Inc.  相似文献   
98.
Gene encoding a novel translation initiation factor PeIF5B from Pisum sativum with sequence similarity to eIF5B from H. sapiens, D. melanogaster, S. cerevisiae as well as archaeal aIF5B from M. thermoautotrophicum was earlier reported by us. We now describe the expression and purification of 96 kDa recombinant PeIF5B (rPeIF5B) protein. Using fluorescence and circular dichroism spectra analyses, we show that Mg(2+) binding does not lead to any change in PeIF5B aromatic amino acid micro-environment, whereas GTP binding induces significant changes in the local environment of the aromatic amino acids. However, the protein undergoes changes in secondary structure upon metal ion and nucleotide binding. Charged initiator tRNA binding to PeIF5B is found to be cofactor dependent. PeIF5B binds to GTP in vitro as evident from autoradiography. Based on homology modeling of the catalytic domain of PeIF5B, we could confirm the conformational changes in PeIF5B following ligand binding.  相似文献   
99.
The application of methoprene, and providing access to diet including hydrolyzed yeast, are treatments known to enhance mating success in the male melon fly Bactrocera cucurbitae Coquillett (Diptera: Tephritidae), supporting their use in mass rearing protocols for sterile males in the context of sterile insect technique (SIT) programmes. The objective of the present laboratory study was to investigate the effect of methoprene application and diet supplementation with hydrolyzed yeast (protein) on the turnover of body lipids and protein to confirm the feasibility of their application in melon fly SIT mass-rearing programmes. While females had access to a diet that included hydrolyzed yeast (protein), males were exposed to one of the following treatments: (1) topical application of methoprene and access to diet including protein (M+P+); (2) only diet including protein (M−P+); (3) only methoprene (M+P−) and (4) untreated, only sugar-fed, control males (M−P−). Total body carbon (TBC) and total body nitrogen (TBN) of flies were measured at regular intervals from emergence to 35 days of age for each of the different treatments. Nitrogen assimilation and turnover in the flies were measured using stable isotope (15N) dilution techniques. Hydrolyzed yeast incorporation into the diet significantly increased male body weight, TBC and TBN as compared to sugar-fed males. Females had significantly higher body weight, TBC and TBN as compared to all males. TBC and TBN showed age-dependent changes, increasing until the age of sexual maturity and decreasing afterwards in both sexes. Methoprene treatment did not significantly affect TBC or TBN. The progressive increase with age of TBC suggests that lipogenesis occurs in adult male B. cucurbitae, as is the case in other tephritids. Stable isotope dilution was shown to be an effective method for determining N uptake in B. cucurbitae. This technique was used to show that sugar-fed males rely solely on larval N reserves and that the N uptake rate in males with access to diet including hydrolyzed yeast was higher shortly after emergence and then stabilized. The implications of the results for SIT applications are discussed.  相似文献   
100.
Three bacterial strains, two of Klebsiella sp. and one Enterobacter cloacae were isolated from industrial effluents of chemical and textile industries. They showed high efficiency in removing cadmium (Cd2+) from the medium. When 100 g/ml of Cd was added to the medium, the three isolates namely CMBL-Cd1, CMBL-Cd2 and CMBL-Cd3 removed or accumulated 86%, 87% and 85% of Cd, respectively, from the medium within 24h. Plasmids were detected in all the three strains. Plasmids of E. cloacae (pCBL1) and Klebsiella sp. (pCBL2 and pCBL3), estimated to be 6.6kb, were used to transform Escherichia coli C600. The transformed E. coli cells showed elevated resistance to Cd. Ethidium bromide curing indicated the presence of the Cd resistance gene on the plasmid. Resistance of the isolated strains against other metals like chromium (cr6+) and lead (pb2+) and a number of antibiotics was also checked. Cured strains showed lowered resistance against Cr and some antibiotics. This again supported the indication of the presence of Cd, Cr and some antibiotics resistance genes on plasmids.  相似文献   
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