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51.
Free radicals produced by ulcerogenic agents affect the TCA cycle enzymes located in the outer membrane of the mitochondria. Upon induction with ulcerogens, peroxidation of membrane lipids bring about alterations in the mitochondrial enzyme activity. This indicates an increase in the permeability levels of the mitochondrial membrane. The ability of PSE to scavenge the reactive oxygen species results in restoration of activities of TCA cycle enzymes. NSAIDs interfere with the mitochondrial beta-oxidation of fatty acids in vitro and in vivo, resulting in uncoupling of mitochondrial oxidative phosphorylation process. This usually results in diminished cellular ATP production. The recovery of gastric mucosal barrier function through maintenance of energy metabolism results in maintenance of ATP levels, as observed in this study upon treatment with PSE. Membrane integrity altered by peroxidation is known to have a modified fatty acid composition, a disruption of permeability, a decrease in electrical resistance, and increase in flip-flopping between monolayers and inactivated cross-linked proteins. The severe depletion of arachidonic acid in ulcer induced groups was prevented upon treatment with PSE. The acid inhibitory property of the herbal extract enables the maintenance of GL activity upon treatment with PSE. The ability to prevent membrane peroxidation has been traced to the presence of active constituents in the PSE. In essence, PSE has been found to prevent mitochondrial dysfunction, provide mitochondrial cell integrity, through the maintenance of lipid bilayer by its ability to provide a hydrophobic character to the gastric mucosa, further indicating its ability to reverse the action of NSAIDs and mast cell degranulators in gastric mucosa. 相似文献
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Beneficial effects of alpha linolenic acid rich flaxseed oil on growth performance and hepatic cholesterol metabolism in high fat diet fed rats 总被引:1,自引:0,他引:1
Vijaimohan K Jainu M Sabitha KE Subramaniyam S Anandhan C Shyamala Devi CS 《Life sciences》2006,79(5):448-454
The purpose of the study was to investigate the effect of flaxseed oil (FO), rich in alpha-linolenic acid (ALA) (18:3 n-3) on growth parameters and lipid metabolism of rats fed with high fat diet. High fat diet (HFD) resulted in significant alterations in hepatic lipids, increase in body weight gain and negative effect on lipoprotein metabolism. FO supplementation significantly lowered the increase in body weight gain, liver weight, plasma cholesterol, triglycerides, phospholipids, free fatty acids, high-density lipoprotein (HDL), low-density lipoprotein-cholesterol (LDL-C), very low-density lipoprotein (VLDL), LDL/HDL and TC/HDL ratio in HFD fed rats. FO significantly reduced the hepatic and plasma lipid levels indicating its hypolipidemic activity. On the other hand, oral administration of FO exhibited lower plasma lipoprotein profile as compared to HFD rats. Hepatic protection by FO is further substantiated by the normal liver histological findings in HFD fed rats. These data suggest that FO participate in the normal regulation of plasma lipid concentration and cholesterol metabolism in liver. No adverse effect of FO on growth parameters and plasma lipids in rats fed with fat-free diet. The results of the present study demonstrate that FO may be developed as a useful therapy for hyperlipidemia through reducing hepatic lipids, thereby proving its hypolipidemic activity. 相似文献
55.
Circulating tumor cells (CTCs) shed from primary and metastatic cancers are admixed with blood components and are thus rare, making their isolation and characterization a major technological challenge. CTCs hold the key to understanding the biology of metastasis and provide a biomarker to noninvasively measure the evolution of tumor genotypes during treatment and disease progression. Improvements in technologies to yield purer CTC populations amenable to better cellular and molecular characterization will enable a broad range of clinical applications, including early detection of disease and the discovery of biomarkers to predict treatment responses and disease progression. 相似文献
56.
Wolfgang P. J. Dittus Shyamala M. Ratnayeke 《International journal of primatology》1989,10(3):215-234
Toque macaques (Macaca sinica),inhabiting natural forest at Polonnaruwa, Sri Lanka, are frequently injured in fights with conspecifics. The behavior of known
individuals when they were injured was compared to that after they had recovered their health. Thus, injured animals rested
and alloand autogroomed more, but they foraged less and initiated fewer aggressive episodes. They spent most time being sedentary
in the safety of arboreal refuges and reduced acrobatic movements by locomoting more often terrestrially. Other group members
showed no special tolerance (or altruism) toward injury victims during the costly and highly competitive activity of foraging
for food. In fact, some injured animals received more aggression, or lost dominance rank, and thereby had their competitive
abilities further impaired. Care for the injured was manifest mostly by grooming and wound cleaning. All hair in the area
surrounding a wound, as well as dirt, scabs, and fly larvae, were removed, and saliva was applied by licking the wound (wounds
so treated healed with no obvious signs of infection). (1) Injured macaques sought and received significantly more grooming
(owing to wound care); (2) the amount so received increased with the severity of the injury; and (3) the initiative of other
group members often compensated for a victim’s inability to solicit care. Juvenile males were especially attentive to injured
adult males, suggesting that they were investing in a social bond with these adults, which might reciprocate altruism toward
their juvenile caregivers in the future. Injured juvenile females received most care from their mothers. 相似文献
57.
Tandem chromosomal duplications: role of REP sequences in the recombination event at the join-point. 总被引:18,自引:1,他引:17
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We show that a family of prokaryotic repetitive sequences, called REP (repetitive extragenic palindromic), (Stern et al., 1984) is involved in the formation of chromosomal rearrangements such as duplications. The join-points of seven RecA+ tandem duplications previously characterized in Salmonella typhimurium, that fuse the hisD gene to distant foreign promoters, were cloned and sequenced. In all seven cases they are shown to have originated by recombination between distant REP sequences. Importantly, several join-points had also occurred at REP sequences even in a RecA-background. Thus, REPs can recombine with each other by a RecA(-)-independent mechanism involved in the generation of chromosomal rearrangements. While all RecA+ duplications analysed resulted from recombination between REP sequences, some RecA-duplications did occur also outside of REP sequences, in one case by recombination within a 7 bp homology. Possible roles for the known interaction between DNA gyrase and REP in chromosomal rearrangements are discussed. 相似文献
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Dakshinamurti S 《Canadian journal of physiology and pharmacology》2005,83(10):893-898
Neonatal circulatory transition is dependent upon tightly regulated pulmonary circuit relaxation. Persistent pulmonary hypertension (PPHN), a rapidly progressive disease of pulmonary arterial vasospasm and remodelling, may be characterized by pulmonary arterial myocyte relaxation failure. A key regulator of vascular tone is myocyte calcium sensitivity, determined by the relative stoichiometry of myosin light chain phosphorylation and dephosphorylation. We have recently reported downregulation of myosin light chain phosphatase activity in a hypoxic model of neonatal pulmonary hypertension. This review examines the recognized pathways of regulation governing myosin light chain phosphatase activity, including targeting subunit isoform switching, targeting unit phosphorylation and catalytic site inhibition. In light of the reviewed literature, further speculation is proposed on the potential contributions of these mechanisms to the pathophysiology of the perinatal pulmonary arterial relaxation defect in PPHN. 相似文献
60.
YfiT, a 19-kDa polypeptide from Bacillus subtilis, belongs to a small sequence family with members predominantly from Gram positive bacteria. We have determined the crystal structure of YfiT in complex with Ni(2+) to a resolution of 1.7 A. YfiT exists as a dimer and binds Ni(2+) in a 1:1 stoichiometry. The protein has an unusual four-helix bundle topology and coordinates Ni(2+) in an octahedral geometry with three conserved histidines and three waters. Although there is no similarity in their overall structures, the coordination geometry of the metal and the residues that constitute the putative active site in YfiT are similar to those of metalloproteases such as thermolysin. Our structural analyses suggest that YfiT might function as a metal-dependent hydrolase. 相似文献