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Biomedical subjects

I Khatri

Publications and source records attributed to I Khatri.

9 recordsLinked to original sources

Role of MIF and glutathione, in association with fetal ovine globin chain (Hbgamma) and LPS, in induction of TNFalpha from cells of young and aged mice, and PBL from healthy human populations.

Previous reports from our group have established that the fetal ovine gamma globin chain (Hbgamma) and LPS can synergize in the induction of pro-inflammatory cytokines, especially TNFalpha, from mouse and human leukocytes. A fetal sheep liver extract (FSLE) which was observed to have marked immunoregulatory properties in vivo and in vitro had independently been observed to contain significant amounts of each of these molecules. However, the biological activity of this extract (hereafter FSLE) was not explained solely by its content of Hbgamma and LPS, and independent analysis confirmed also the presence of migration inhibitory factor, MIF, and glutathione in FSLE. We have investigated whether MIF and the cellular anti-oxidant glutathione can further synergize with Hbgamma and LPS in TNFalpha induction from human cells in vitro, and mouse cells activated in vivo/in vitro. Our data show that indeed there is evidence for such a synergy. Treatment or mouse cells with FSLE produced an enhanced TNFalpha production which could be inhibited independently both by anti-Hbgamma and by anti-MIF, and optimally by a combination of these reagents.

Aging↗

Analysis of interaction of cloned human and/or sheep fetal hemoglobin gamma-chain and LPS in augmenting induction of inflammatory cytokine production in vivo and in vitro.

We have reported earlier that purified preparations of sheep fetal hemoglobin, but not adult hemoglobin, in concert with non-stimulatory doses of lipopolysaccharide (LPS) (lipid A), act cooperatively to regulate in vitro production of a number of cytokines, including TNFalpha, TGFbeta and IL-6 from murine and human leukocytes. Following in vivo treatment of mice with the same combination of hemoglobin and LPS, harvested spleen or peritoneal cells showed a similar augmented capacity to release these cytokines into culture supernatants. We report below that genetically cloned gamma-chain of human or sheep fetal hemoglobin, but not cloned alpha- or beta-chains, can produce this cooperative effect, as indeed can HPLC purified, heme-free, gamma-chains derived from cord blood fetal hemoglobin, and that purified haptoglobin completely abolishes the cooperative interaction.

Age Factors↗

Human intestinal mucin-like protein (MLP) is homologous with rat MLP in the C-terminal region, and is encoded by a gene on chromosome 11 p 15.5.

A cDNA specific for a human intestinal mucin (MLP) was amplified by PCR from cDNA of cultured human colonic adenocarcinoma cells, LS174T. The human cDNA shared high sequence homology with a corresponding rat intestinal mucin (MLP) cDNA in the 3' terminal region, and hybridized to the same mRNA (approximately 9.0 Kb) that was recognized by a probe for the MUC-2 human intestinal mucin gene. The gene encoding our human mucin peptide also mapped to chromosome 11 p 15.5, the known locus of MUC-2. Our findings suggest that human MLP and MUC-2 are encoded by the same gene and that rat and human intestinal mucin share a common C-terminal amino acid structure.

Adenocarcinoma↗

Treatment of hypertension in the elderly. III. Response of isolated systolic hypertension to various doses of hydrochlorothiazide: results of a Department of Veterans Affairs cooperative study. Department of Veterans Affairs Cooperative Study Group on Antihypertensive Agents.

In a double-blind randomized study, we evaluated the effects of 25 mg vs 50 mg of hydrochlorothiazide in 51 elderly patients (aged 68.9 +/- 7.0 years) with isolated systolic hypertension (blood pressure, 160 to 239 mm Hg systolic and less than 90 mm Hg diastolic). Dose levels could be increased to twice daily to control blood pressure. The reductions in blood pressure (25.4/6.8 mm Hg and 28.9/7.4 mm Hg) and proportion of patients in whom blood pressure was controlled (78% and 89%) were similar in the lower- and higher-dose groups during the titration phase. However, serum potassium level was reduced more in the higher-dosage (0.57 mmol/L) than the lower-dosage (0.17 mmol/L) group. There were no significant changes in blood pressure during a 24-week maintenance phase. No patient required withdrawal from the study because of adverse effects, and cognitive-behavioral function was well preserved. We conclude that hydrochlorothiazide is effective and well tolerated in older patients with isolated systolic hypertension, many of whom may be effectively treated with 25 mg of hydrochlorothiazide once daily.

Aged↗

Mucin depletion in the intestine of malnourished rats.

The effects of malnutrition on mucosal goblet cell mucin levels were studied in rats deprived of 50% of their daily intake, as judged by pair-fed, age-matched control animals, for 5 wk. Average daily weight gain was 0.7 g/day compared with 5.8 g in age-matched (AM) rats; final weight was 246 +/- 9 g compared with 406 +/- 4 g. Immunoassayable mucin, sucrase, protein, and DNA were assayed in mucosal scrapings from the proximal, middle, and distal segments of the small intestine in malnourished rats, AM rats, and a third group of low-weight, less mature (LM) rats. Total protein, total DNA, and protein-to-DNA ratios in malnourished rats were unchanged compared with AM control rats and often higher than levels in LM control rats. In malnourished animals, mucin concentration per milligram protein was significantly decreased below AM control animals in the upper two segments and below LM control animals in all segments. Mucin concentration per milligram DNA was significantly lower in malnourished rats than in all segments of both control groups. In contrast, sucrase activity per milligram protein or DNA was either unchanged or increased in the malnourished rats, indicating that the reduction in mucin concentration was selective and did not reflect all surface glycoproteins. Isolated mucins from malnourished and AM control rats were chemically similar, and the affinity and number of antigenic determinants were the same. Malnutrition therefore leads to an absolute decrease in intestinal mucin rather than reduced molecular antigenicity. Impaired capacity to maintain mucosal mucin content may be a factor in reducing intestinal resistance to enteric infection in malnutrition.

Animals↗

Effect of therapy on left ventricular function in hypertension.

1. Twelve untreated hypertensive patients whose blood pressure was 171.8 +/- 5.5 mmHg systolic and 119.7 +/- 3.4 mmHg diastolic (mean +/- SEM) were treated aggressively with diuretics plus other antihypertensive agents. Echocardiograms were performed before, and 2 weeks, 3 months and 6 months after therapy. Blood pressures were lowered to an average of 142/98 mmHg over the 6 month period. 2. Mean velocity of circumferential fibre shortening rose from 1.1 +/- 0.09 to 1.3 +/- 0.06 diameters/s at 2 weeks and remained elevated at the end of 3 months (1.3 +/- 0.03 diameters/s) (P < 0.025), but returned to the control level in 6 months. Similarly, ejection fraction increased significantly during the same period from a control value of 65.1 +/- 4.4 to 73.4 +/- 1.8% (P < 0.025) and persisted in this range at 3 months. At 6 months the ejection fraction had returned to pretreatment levels. There were significant reductions in left ventricular end-systolic and end-diastolic dimensions. Left ventricular mass index decreased from 182.3 +/- 18.3 to 163.8 +/- 12.4 g/m2 after 6 months of therapy. 3. These results indicate that in the early stages of blood pressure reduction there is a temporary increase in ejection phase indices, probably related to afterload reduction. The reduction in the left ventricular mass index suggests that increased cardiac muscle mass due to elevated blood pressure may be partially reversible after long-term reduction in blood pressure.

Adult↗

Mechanism of antihypertensive effect of thiazide diuretics.

Hemodynamic studies were carried out before and during 8 weeks of treatment with hydrochlorothiazide 50 mg. twice daily in 11 hypertensive patients. Forty-eight hours after beginning treatment there was a significant reduction in blood pressure, cardiac output, plasma volume, and extracellular fluid volume (thiocyanate space) while total peripheral resistance increased. After 6 and 8 weeks of treatment, the blood pressure and the plasma and extracellular volumes remained reduced. However, total peripheral resistance fell while cardiac output rose to control levels. These results were consistent with the "reverse autoregulation" theory of the action of the thiazides as proposed by Tobian. The present evidence discussed below makes it appear unlikely that the thiazides have an important direct vasodilator effect.

Antihypertensive Agents↗