Search PubMed⌕ Search

Biomedical subjects

H Shah

Publications and source records attributed to H Shah.

At least 91 records · Page 5Linked to original sources
PubMed1983

Interstitial deletion of 8q. Occurrence in a patient with multiple exostoses and unusual facies.

A patient with multiple exostoses, mental retardation, and unusual facies has an interstitial deletion of the long arm of chromosome 8, or 46,XX, del (8) (pter leads to q22::q24.1 leads to qter). She has some features of the Langer-Giedion syndrome, but her facies are not characteristic and she does not have cone-shaped phalangeal epiphyses. Of the eight previous reports of partial deletion of the long arm of chromosome 8, four patients had exostoses and unusual facies, three of whom had characteristics of the Langer-Gieldion syndrome. The deleted segments in the patients with exostoses are not identical, although there are areas of deletion that are seen in more than one patient. Among the explanations of the relationship of the 8q deletions to exostoses is the presence of several loci on 8q that are involved in bone formation, the deletion of any of which may give rise to a similar skeletal defect.

Adolescent↗
PubMed1982

Purification and properties of inorganic pyrophosphatase of rat liver and hepatoma 3924A.

Inorganic pyrophosphatase (EC 3.6.1.1) has been purified to electrophoretic homogeneity from the soluble portion of the cytoplasm of rat Hepatoma 3924A and rat liver. It has a specific activity of 600 to 700 mumol inorganic orthophosphate liberated per min per mg protein at 25 degrees, a value in the same range as the highly purified enzymes from yeast and Escherichia coli. By all criteria applied, the hepatoma inorganic pyrophosphatase is identical with the liver enzyme. It is a dimer with subunits with molecular weights of approximately 30,000 to 33,000 and has a pH optimum of 7.4, a Km for pyrophosphate of 5 microM, and a Ka for Mg2+ of 0.3 mM with a pyrophosphate concentration of 0.2 mM. It is not inhibited by high Mg2+ concentrations up to 20 mM. Other metal ions such as Zn2+ and Ca2+ do not activate. Mn2+ activates to less than 10% that of Mg2+ at 0.6 mM and has no effect at 1 mM or higher. In the presence of optimal (4 mM) Mg2+ concentration, Ca2+, Mn2+, Hg2+, and F- at 0.2 mM inhibited strongly, but Zn2+ at 1 mM was not inhibitory. The enzyme had no phosphatase activity toward any of the purine or pyrimidine nucleoside mono-, di-, and triphosphates or toward p-nitrophenyl phosphate, beta-glycerophosphate, glucose 6-phosphate, or glucose 1-phosphate. Bromo- or iodoacetate at high concentration had no inhibitory effect, but p-chloromercuribenzoate and p-chloromercuriphenylsulfonate inhibited strongly at low concentration. The purified enzyme was very unstable but was protected markedly at or above the pH optimum of 7.4 by cysteine, dithiothreitol, and glutathione.

Adenosine Triphosphate↗
PubMed1979

Formation of carbonyl chloride in carbon tetrachloride metabolism by rat liver in vitro.

In order to identify intermediates of CCl4 metabolism, whole, suitably fortified rat liver homogenates were incubated with 14CCl4 in the presence and absence of "pools" of unlabeled suspected intermediates. In the presence of NADH or NADPH, incorporation of radioactivity was rapid and substantial in CO2, lipid, protein, and the acid-soluble fraction. It was not influenced by the presence of large pools of unlabeled chloroform or formate, thus excluding these substances as obligatory intermediates. However, when incubated with L-cysteine, radioactivity incorporation in the acid-soluble fraction was almost doubled, and about one-third of the radioactivity of this fraction was identified as 2-oxothiazolidine 4-carboxylic acid. This substance is formed chemically by condensation of cysteine with carbonyl chloride and has been identified previously by others as a product of chloroform metabolism by liver microsomes in the presence of L-cysteine. Based on current knowledge of CCl4 metabolism, the following aerobic pathway is envisioned: microsomal cleavage to Cl- and .CCl3 and oxidation of the latter to the unstable intermediate, Cl3COH, which loses HCl to yield COCl2. COCl2 is likely to be the major source of CO2 from CCl4 but is probably not the intermediate that binds to lipid and protein. The addition of glutathione had no effect on CCl4 metabolism in rat liver homogenate, suggesting that glutathione S-transferases, which catalyze other dehalogenation reactions, do not play a role in CCl4 metabolism.

Aerobiosis↗
PubMed1977

Metabolism of [3H]-methylcholanthrene in the perfused rat liver.

The metabolism of [3H]-3-methylcholanthrene (3-MC) was studied in the isolated, perfused rat liver. Following addition of 250 mug to the perfusion fluid, 3-MC disappeared rapidly. After 2 hr, approximately 34% of the radioactivity was excreted in the bile, 6% remained in the perfusate, and 60% was found in the liver. Of the liver radioactivity, 80% was unchanged 3-MC, 11% was conjugated metabolites, 4% was free hydroxymetabolites, and 4% was nonextractable, presumably bound to macromolecules. Of the perfusate radioactivity, 82% was conjugated metabolites, 3% was free hydroxymetabolites, and 15% was unchanged 3-MG. A similar distribution was observed in intact, bile-cannulated rats, but biliary excretion was about one-fourth as high with double the i.v.-injected dose. Biliary excretion in perfused livers rose rapidly during the first 30 to 40 min, then decreased steadily. It was nearly twice as high in male as in female rat livers. Pretreatment of rats with 3-MC more than doubled the biliary excretion rate over the first 20 to 30 min in livers of both sexes and raised that of the female to that of the male rat liver. Neither retinol acetate nor 7,8-benzoflavone had any appreciable effect on biliary excretion of 3-MC metabolites. 2-Diethylaminoethyl-2,2-diphenylvalerate, a well-known microsomal oxygenase inhibitor, lowered excretion by 80 to 90% and lengthened the lag period, and dibutyryl-3',5'-cyclic adenosine monophosphate markedly increased the rate of excretion of 3-MC metabolites. Fractionation of bile by chromatography on Sephadex LH-20 revealed six well-defined peaks of radioactivity. In contrast, bile of intact rats given 3-MC gave a pattern on Sephadex chromatography consisting of only three peaks. Preliminary data suggest that these consist of conjugates of dihydroxymetabolites as well as more highly hydroxylate derivatives. The data obtained indicate that the perfused liver is an appropriate experimental model for studies on the hepatobiliary metabolism of carcinogens.

Animals↗
PubMed1975

Age-related incidence of sclerotic glomeruli in human kidneys.

The incidence of sclerotic glomeruli as a function of age in kidneys from 122 patients without clinical evidence of renal disease or hypertension was estimated by histologic quantitation. Based on statistical analysis of data from this sample, 95% of the normal population up to 40 years of age would be expected to have less than 10% sclerotic glomeruli. After the age of 40 years, the upper limit containing 95% of the normal population exceeds 10% sclerosis, and after the age of 50, there is a broad scatter of observed percentage of sclerotic glomeruli. These findings suggest that, in patients 40 years of age and younger, sclerosis of glomeruli at an incidence greater than 10% is disease-related, while in patients older than 40 years (and particularly those older than 50), there is a transition, and the distinction between abiotrophic involutional sclerosis and disease-related sclerosis becomes less clear.

Adolescent↗
PubMedDate not supplied

Incidence and management of arterial emboli from hemodialysis graft surgical thrombectomy.

PURPOSE: To determine the incidence and significance of arterial emboli resulting from surgical thrombectomy/revision of hemodialysis grafts. This information may help in determining the significance and management of similar emboli resulting from percutaneous hemodialysis graft thrombolysis. PATIENTS AND METHODS: Patients undergoing surgical thrombectomy/revision of clotted hemodialysis grafts are studied with postoperative fistulography per institutional protocol whenever possible. For this retrospective study, all postoperative fistulograms from a 1-year period were reviewed for the presence of arterial emboli. Patients with documented arterial emboli were examined for evidence of hand/digital ischemia; only those patients with signs or symptoms of ischemia were treated. At clinical follow-up, repeated evaluation for hand/digital ischemia was performed. RESULTS: Ninety-one thrombectomy/revision procedures were performed during the study period. Postoperative fistulograms were obtained after 67 of these procedures in 32 patients. One patient complained of hand pain during dialysis prior to acquisition of the postoperative fistulogram. Arterial emboli were documented in eight patients (12%; brachial, n = 3; radial, n = 2; ulnar, n = 2; radial/ulnar, n = 1). The single symptomatic brachial embolus was percutaneously removed; no intervention was undertaken in the remainder. At mean follow-up of 14 months, no patient had developed hand or digital ischemia. Subsequent fistulograms demonstrated partial (n = 2) or complete (n = 2) resolution of the untreated emboli. CONCLUSION: Arterial emboli are a relatively common occurrence with surgical thrombectomy/revision. Conservative management appears to be indicated in asymptomatic patients.

Angiography↗
PubMedDate not supplied

Comparison of digital subtraction and cut film arteriography in the evaluation of suspected thoracic aortic injury.

PURPOSE: To determine whether intraarterial digital subtraction arteriography (DSA) is as sensitive and specific as cut film arteriography (CFA) in the evaluation of suspected aortic injury resulting from blunt chest trauma. MATERIALS AND METHODS: Both CFA and DSA images of the thoracic aorta were obtained in the right posterior oblique (RPO) projection in 100 of 103 consecutive patients undergoing arteriography after blunt chest trauma. Diagnoses based on blinded separate review of both studies (CFA vs DSA) by four independent reviewers were compared. Reviewers graded their confidence in their diagnoses from 1 (certain) to 10 (uncertain). RESULTS: Eleven of 100 patients had aortic or great vessel injuries confirmed by operation (n = 10) or transesophageal echocardiography (n = 1). Three hundred eighty-eight of 400 diagnoses based on RPO CFA and 390 of 400 diagnoses based on RPO DSA agreed with the correct diagnoses. The sensitivity, specificity, and diagnostic accuracy of CFA versus DSA were not significantly different. The reviewers' confidence in their diagnoses was equivalent between CFA (average confidence score, 1.373) and DSA (average confidence score, 1.375). CONCLUSION: DSA and CFA yield equivalent sensitivity, specificity, and diagnostic accuracy in the evaluation of blunt chest trauma.

Adolescent↗