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Biomedical subjects

S Kapur

Publications and source records attributed to S Kapur.

At least 181 records · Page 10Linked to original sources

Influence of ellagic acid on antioxidant defense system and lipid peroxidation in mice.

Addition of ellagic acid (EA) to liver microsomes of mice resulted in a steady increase in inhibition of NADPH-dependent lipid peroxidation up to 2 mM concentration. The maximum of 70% inhibition of ascorbate-dependent lipid peroxidation was achieved at 1 mM concentration of EA. Feeding of EA significantly increased the levels of reduced glutathione and glutathione reductase in liver and lungs of male and female mice. However, there were no changes in the activities of catalase and superoxide dismutase. On the other hand, microsomes from liver and lungs of EA fed animals showed significantly suppressed NADPH- and ascorbate-dependent lipid peroxidation.

Animals↗

DiGeorge anomaly in an infant with deletion of chromosome 22 and dup(9p) due to adjacent type II disjunction.

A term white girl presented with low birth weight, minor anomalies, and congenital heart defects. The infant had microcephaly, upslanting palpebral fissures, prominent nasal bridge, short philtrum, thin upper lip vermilion, down-turned corners of the mouth, receding mandible, and short broad neck. The hands showed proximal placement of the thumbs, bilateral clinodactyly of the index finger, and bilateral transverse crease. Both hands were clenched, with the index finger overlapping the third finger and the fifth finger overlapping the fourth. There was also talipes calcaneo-valgus, bilateral dorsiflexion of the metatarsophalangeal joints, flexion of the interphalangeal joints, and hypoplasia of all nails. The patient's karyotype was 46,XX,-22, + der(9)t(9;22)(q21.13;q12.1)mat; the mother had the balanced translocation 46,XX,t(9;22)(9pter----9q21.13::22q12.1----22qter++ +;22pter---- 22q12.1::9q21.3----9qter). The infant died at age 10 days, and the autopsy showed absent thyroid isthmus and rudimentary thymus, with one small ectopic parathyroid attached to it. The lungs were hypoplastic, with abnormal lobation. The cardiac anomalies included truncus arteriosus, truncal valve stenosis, single carotid trunk, subclavian arteries arising from the distal part of the aortic arch, atrial and ventricular septal defects, right ventricular hypertrophy, and a hypoplastic left pulmonary artery. Also, multiple small accessory spleens were present in addition to a normal-sized spleen. This case combines features associated with DiGeorge anomaly and dup(9p). The chromosome abnormality in this patient appears to have arisen in a maternal germ cell due to adjacent type II disjunction.

Chromosome Deletion↗

Pathophysiologic glucocorticoid levels and survival of translocating bacteria.

Burn wound sepsis in rats results in sustained corticosterone elevations and the prolonged presence of translocated bacteria in the mesenteric lymph nodes (MLNs). To determine if survival of bacteria in the MLNs may be influenced by pathophysiologic corticosterone levels, MLNs were quantitatively analyzed from rats randomized to the following groups: burn wound sepsis (BI); BI with adrenocortical response attenuated by cyclosporine (cyclosporine/BI); or cyclosporine/BI with corticosterone replacement (cyclosporine/BI + P). Although rates of bacterial translocation were similar, corticosterone levels were significantly different among the three groups and correlated with the number of lymphocytes and the number of enteric bacteria present per gram of MLN. Thus, pathophysiologic elevations of corticosterone levels during sepsis may exert an effect that allows survival of translocated bacteria in the MLNs of rats, perhaps due to glucocorticoid-associated alterations in regional immunity.

Administration, Cutaneous↗

Use of random-sequence riboflavin as a marker of medication compliance in chronic schizophrenics.

Adherence to prescribed medications is believed to be a major problem in medicine. However, actual medication taking behaviour is rarely measured as no reliable objective measures of adherence are available. 50 mg of riboflavin administered at night could be reliably detected in urine, under UV light, for the next 18-24 h. The ability of 20 schizophrenic outpatients to adhere to a once-a-night dosage was studied by dispensing riboflavin or placebo in a random sequence and testing the urine for UV fluorescence the next day. The majority of patients (80%) had errors between 40-80% of the times tested. Only age and sex predicted the level of adherence. Clinicians were very poor predictors of the error rates in their patients.

Adult↗

Germ-line mosaicism in Waardenburg syndrome.

A family with three children with Waardenburg syndrome born to normal, unrelated parents is reported. This appears to be the first report suggesting germ-line mosaicism in Waardenburg syndrome.

Adult↗

Magnetic resonance spectroscopy in psychiatry: potential, pitfalls, and promise.

Magnetic resonance spectroscopy (MRS) is a novel noninvasive approach to measuring important metabolites in living tissue. Its application to psychiatry is just beginning. In vivo MRS with 31P provides important information on brain phospholipid metabolism and energy production. In vivo 13C and 1H MRS can reveal information about carbohydrate, protein, and amino acid metabolism. In vivo 7Li and 19F MRS can be used to study the pharmacology of lithium and fluorinated psychopharmacological agents. MRS with 23Na can yield information about electrolyte balance. The limitations of in vivo MRS include poor sensitivity, poor resolution, and the fact that only highly mobile atomic nuclei can be detected. Future clinical application of MRS will benefit from improvements in the technology of localization, use of spectroscopy contrast agents, stronger magnets, and the merging of MRS and imaging technology.

Brain↗

Inhibition of arylhydrocarbon hydroxylase and cytochrome P-450 by 20-methylcholanthrene and phenobarbital in guinea pig on excessive doses of ascorbic acid.

Treatment of guinea pigs on adequate ascorbic acid (AA) with 20-methylcholanthrene (MCA) and phenobarbital (PB) significantly increased hepatic arylhydrocarbon hydroxylase (AHH), cytochrome P-450 and cytochrome-b5 activities. In lungs, only MCA treatment significantly enhanced the activities of AHH, cytochrome P-450 and cytochrome b5. In animals on excessive doses of AA, there was inhibition of hepatic AHH, cytochrome P-450 and cytochrome b5 levels by treatment with these xenobiotics. Also, inhibition was observed in pulmonary AHH and cytochrome P-450 levels. The relevance of these observations in excessive AA-fed guinea pigs to carcinogenesis requires further extensive investigations.

Animals↗

Apparently previously undescribed X-linked dominant syndrome with facial and skeletal anomalies.

We report on a syndrome of widow's peak, ptosis, skeletal abnormalities and other minor anomalies in a large family. The condition appears to be inherited in an X-linked dominant fashion. No similar cases have been found in the literature, suggesting that this is a "new" syndrome. Study of 5 generations of the family documents information on the natural history of the condition.

Adolescent↗

High-dose, pulse intravenous methylprednisolone enhances Fc gamma receptor-mediated mononuclear phagocyte function in systemic lupus erythematosus.

The benefit of high-dose, pulse intravenous methylprednisolone (IVMP) for some patients with active lupus nephritis would appear paradoxical, since active nephritis is associated with profound abnormalities in Fc gamma receptor function, and several studies have demonstrated that glucocorticoids decrease monocyte Fc gamma receptor expression and phagocytic function. To resolve this paradox, we investigated the possibility that pulse IVMP might enhance monocyte Fc gamma receptor function in patients with systemic lupus erythematosus (SLE). Circulating immune complex (CIC) levels, Fc gamma receptor-mediated clearance, and Fc gamma receptor-dependent monocyte function were analyzed in 23 SLE patients before and after pulse IVMP (1 gm daily for 3 days). A biphasic response in CIC levels, determined by a staphylococcal protein A binding assay, was observed. Initially, CIC levels increased within 2-4 hours after the first dose of pulse IVMP and then decreased by 50% within 24-48 hours after the completion of therapy. Fc gamma receptor-mediated binding and phagocytosis of IgG-sensitized erythrocytes (EA) by monocytes in vitro were significantly enhanced 24 hours after the final dose of pulse IVMP (pre-IVMP versus post-IVMP 43 +/- 14% versus 53 +/- 12% EA rosettes, P less than 0.01; 3.00 +/- 1.04 versus 3.99 +/- 1.30 EA ingested/monocyte, P less than 0.01). In contrast, there was no change in the phagocytosis of an Fc gamma receptor-independent probe, neuraminidase-treated erythrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Cerebrovascular accidents in neonates treated with extracorporeal membrane oxygenation: sonographic-pathologic correlation.

Neonates treated with extracorporeal membrane oxygenation are at high risk for the development of intracranial hemorrhage and infarction. The appearance of these lesions on cranial sonography is often unusual and may be confusing. We compared the findings at autopsy with premorbid cranial sonograms in 17 nonsurviving neonates to define better the anatomic basis for the sonographic appearance of these lesions. Macroscopic abnormalities were identified at autopsy in 13 of the 17 neonates. Five neonates had multifocal hemorrhagic white-matter infarcts, three had large parenchymal hemorrhages with adjacent areas of parenchymal necrosis, three had hemorrhagic infarcts of the cerebellum, one had a germinal matrix and intraventricular hemorrhage, and one had bilateral periventricular cysts with surrounding gliosis. All 17 neonates had abnormalities on microscopic examination. Although sonography was accurate in the detection of macroscopic lesions (11 of 13 lesions detected with sonography), the nature and extent of these abnormalities were difficult to judge because of the variable echogenicity of unclotted blood and the presence of focal areas of abnormal echogenicity associated with microscopic calcification and gliosis. Sonography is excellent for the detection of acute cerebrovascular complications during extracorporeal membrane oxygenation, but the appearance of these lesions is variable and nonspecific.

Brain↗

Inhibition kinetics of lactate dehydrogenase isoenzymes by gossypol acetic acid.

The effect of gossypol acetic acid, a potent male sterilent was studied on LDH from goat liver (LDH-A4), heart (LDH-B4) and testis (LDH-C4) in vitro. All the preparations of LDH were inhibited by gossypol when the reaction was carried out in pyruvate-lactate (direct) or lactate to pyruvate (reverse) directions. The IC50 of gossypol for the pyruvate oxidation by LDH isozymes varied between 16 and 42 microM in presence of 0.27 mM pyruvate and 0.15 mM NADH at 25 degrees C and pH 7.4 whereas for the lactate oxidation, IC50 was 125 microM in a system containing 3.3 mM lactic acid and 1.8 mM NAD at 25 degrees C and pH 9.0. Reciprocal plots due to Lineweaver-Burk showed that these isozymes are inhibited in a non-competitive manner with respect to pyruvate and lactate, and in a competitive fashion when NAD and NADH were varied as substrates. Ki values of LDH-A4, -B4 and -C4 isozymes in presence of gossypol were 20, 34 and 29 microM against pyruvate; 33, 43 and 45 microM against NADH; 85, 85 and 125 microM against lactate and 94, 108 and 83 microM against NAD respectively.

Animals↗

Renal histology of mucocutaneous lymph node syndrome (Kawasaki disease).

Renal involvement is well described in patients with mucocutaneous lymph node syndrome (MCLNS), or Kawasaki disease and is manifested by mild azotemia, hematuria, pyuria or cylinduria, and more often, proteinuria. Renal morphology during the acute stages of the illness has never been reported. In this paper we describe the renal histopathologic changes in a child with MCLNS. The glomerular histopathologic findings suggest immune complex damage to the kidney as a possible mechanism of nephrotoxicity in MCLNS. Presence of kidney lesions, which speak in favor of the injurious role of immune complexes in MLCNS may be relevant to the understanding of the pathogenesis of the vascular lesions that are characteristic of this disease.

Antigen-Antibody Complex↗

Opsonin-independent ligation of Fc gamma receptors. The 3G8-bearing receptors on neutrophils mediate the phagocytosis of concanavalin A-treated erythrocytes and nonopsonized Escherichia coli.

We report that phagocytosis by human neutrophils of Con A-treated erythrocytes (E-Con A) and nonopsonized Escherichia coli with mannose-binding adhesions is mediated by the Fc gamma receptor bearing the 3G8 epitope. Modulation of Fc receptors by pretreating with aggregated-IgG or with 3G8 anti-Fc gamma receptor mAb markedly inhibited internalization of E-Con A and E. coli without altering their cell surface attachment. Phagocytosis of these probes was specifically blocked by alpha-methylmannoside and D-mannose and not by other monosaccharides. Thus, recognition of E-Con A and E. coli by the Fc receptor is dependent upon the mannose-specific interaction with lectin or lectin-like adhesions. These data demonstrate that ligands other than the classical IgG opsonins can bind to classical immune receptors for IgG through lectin-carbohydrate interactions.

Concanavalin A↗

Menkes syndrome in a girl with X-autosome translocation.

We report on a girl with Menkes syndrome (M.S.) and X-2 reciprocal translocation. We conclude that the probable locus for M.S. gene is at band Xq13. This case and other previous case reports of X-linked disorders in females suggest that chromosome analysis is indicated in all females who present with manifestations of a known X-linked lethal condition in order to detect a possible associated balanced X-autosome translocation.

Brain Diseases, Metabolic↗