Omar Haq

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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(More)
Increased levels of intestinal VEGF are thought to worsen portal hypertension. The cause of the increase in the level of intestinal VEGF found during cirrhosis is not known. The aim of this study is to demonstrate a relationship between portal pressure (PP) and intestinal/ plasma VEGF levels in different stages of fibrosis/cirrhosis. In this experiment,(More)
The reaction of HIV protease to inhibitor therapy is characterized by the emergence of complex mutational patterns which confer drug resistance. The response of HIV protease to drugs often involves both primary mutations that directly inhibit the action of the drug, and a host of accessory resistance mutations that may occur far from the active site but may(More)
Small organic molecules can assume conformations in the protein-bound state that are significantly different from those in solution. We have analyzed the conformations of 21 common torsion motifs of small molecules extracted from crystal structures of protein-ligand complexes and compared them with their torsion potentials calculated by an ab initio DFT(More)
Clustering of 99 available X-ray crystal structures of HIV-1 reverse transcriptase (RT) at the flexible non-nucleoside inhibitor binding pocket (NNIBP) provides information about features of the conformational landscape for binding non-nucleoside inhibitors (NNRTIs), including effects of mutation and crystal forms. The ensemble of NNIBP conformations is(More)
BACKGROUND/AIMS Cirrhotic livers have a deficient vasodilator response to nitric oxide (NO). The vasodilator effect of NO is normally limited by the degradation of its second messenger cyclic guanosine 3', 5' monophosphate by phosphodiesterases. We investigated (1) the phosphodiesterase-5 (PDE-5) expression in normal and cirrhotic rat livers, (2) the(More)
HIV protease, an aspartyl protease crucial to the life cycle of HIV, is the target of many drug development programs. Though many protease inhibitors are on the market, protease eventually evades these drugs by mutating at a rapid pace and building drug resistance. The drug resistance mutations, called primary mutations, are often destabilizing to the(More)
BACKGROUND AND AIM Livers from lipopolysaccharide-treated rats have a decreased vascular response to alpha(1)-adrenergic agonists due to an increased production of nitric oxide. Kupffer cells play a central role in the development of intrahepatic microvascular abnormalities during endotoxemia. We investigated the role of Kupffer cells in the intrahepatic(More)
Purpose. We examined current osteoporosis prevention practices in patients with inflammatory bowel disease (IBD) on chronic steroid using the 2003 American Gastroenterological Association guidelines as standard of care. Methods. We identified all IBD patients followed at the Oklahoma City VA Medical Center from January 2003 to December 2010, who had been on(More)
A coarse grained model for the electrostatic free energy contribution to the folding of a given protease sequence was calculated using AGB, an implementation of the pairwise descreening Generalized Born (GB) model that makes use of a parameter-free algorithm to take into account atomic overlaps [1].
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