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Biomedical subjects

S Mehta

Publications and source records attributed to S Mehta.

At least 415 records · Page 23Linked to original sources
PubMed1982

Biochemical separation of a human B cell mitogenic factor.

Recent studies have established the ability of human B lymphocytes to undergo G1-phase cell cycle progression and subsequent DNA synthesis upon exposure to factor(s) present in media conditioned by lectin-stimulated mononuclear cells. Procedures for the isolation of such a cytokine have been the focus of the present investigation. Conditioned medium from cells stimulated by lectin for 72 hr was fractionated by ammonium sulfate precipitation, ion-exchange chromatography, and gel filtration chromatography. During the isolation procedure the proliferation-stimulating activity of the column fractions was assayed concurrently on purified human T cells, purified human B cells, and murine thymocytes. T cell and B cell stimulatory factors present in the initial conditioned medium were found to copurify during ammonium sulfate precipitation, DEAE-Sephadex chromatography, and Bio-Gel P-30 gel filtration. However, partial separation of these two activities was achieved after Bio-Gel P-100 gel filtration. Analytic polyacrylamide gel electrophoresis of radiolabeled Bio-Gel P-100 column fractions demonstrated a distinct protein band of 14,000-15,000 daltons in those column fractions predominantly supporting T cell growth and a distinct protein band of 12,000-13,000 daltons for those fractions predominantly supporting B cell growth. The fractions associated with B cell mitogenic activity induced B cell S-phase entry in a proportion of B lymphocytes in the absence of any detectable IgM secretion.

B-Lymphocytes↗
PubMed1982

Growth factors in Hodgkin's disease.

Tumor nodules from spleens removed at staging laparotomy for nodular sclerosing Hodgkin's disease were grown as fragment cultures in vitro. These cultures could be maintained in vitro for up to 2 months and consisted of 90% large, adherent multinuclear and mononuclear cells. Immunologic markers and enzyme histochemistry suggested that the cultured cells belonged to the monocyte/macrophage lineage. Supernatants from these cell cultures were then assayed for the monokine Interleukin I and for fibroblast stimulatory factors, which were both present. These results are discussed in considering Hodgkin's disease as a neoplasm of the monocyte/macrophage lineage, capable of producing functionally active mediators that may account for the histopathologic appearance observed.

Cells, Cultured↗
PubMed1982

Lysosomal enzyme changes in macrophages from mice given myocrisin and infected with avirulent Semliki Forest virus.

Myocrisin given to mice i.p. causes depression of lysosomal enzyme activity (acid phosphatase, beta-glucuronidase and N-acetyl-beta-D-glucosaminidase) in peritoneal macrophages. If avirulent Semliki Forest virus (SFV) is given i.p. 3 h after the Myocrisin, further depression of lysosomal enzyme activity occurs, a very high titre of virus is produced in these macrophages and the virus becomes lethal, causing 100% mortality. The possible interrelationships between depressed lysosomal activity, high virus titres and the production of a lethal virus infection are discussed.

Acetylglucosaminidase↗
PubMed1982

Disposition of four drugs in malnourished children.

Pharmacokinetic studies on antipyrine, chloramphenicol, acetaminophen, and sulphadiazine have been carried out in infants and children suffering from protein-energy malnutrition (PEM). Increased antipyrine plasma half-life in PEM indicated altered mixed oxidative microsomal enzyme activity in hepatocytes. Chloramphenicol was absorbed (ka) as well as eliminated (ke) at slower rates in PEM. The net result was that the comparative bioavailability of the drug was higher in PEM as compared to the control. Observations were similar in the case of sulphadiazine. The rate of absorption (ka) of acetaminophen was not affected in children with PEM, but the elimination rate constant was slower and plasma half-life prolonged. Noticeable improvement was observed within 6-8 weeks of nutritional rehabilitation with respect to chloramphenicol, antipyrine, and acetaminophen pharmacokinetics.

Acetaminophen↗
PubMed1982

Dialytic ascitic ultrafiltration in refractory ascites.

Nine patients with hepatic cirrhosis and refractory ascites underwent dialytic ascitic ultrafiltration with intraperitoneal reinfusion of the concentrated ascites. Ascites was removed via a peritoneal catheter and ultrafiltered using a hemodialyzer. The concentrate was continuously returned to the peritoneal space. A mean of 4.8 l of protein-free ascitic ultrafiltrate was removed without adverse effects over the course of the 3- to 5-h procedure. Preliminary evidence indicates a potential role for dialytic ascitic ultrafiltration in the management of refractory ascites.

Ascites↗
PubMed1981

Clinical performance and endocrine profiles with contraceptive vaginal rings containing a combination of estradiol and D-norgestrel.

Contraceptive vaginal rings (CVRs) impregnated with a combination of estradiol and d-norgestrel were studied in 39 women. The rings were inserted as three weeks "in" and one week "out" schedule to allow withdrawal bleeding. Ovulation was inhibited in all cycles and promptly resumed on completion of the treatment cycles. Bleeding control was excellent. Incidence of breakthrough bleeding was 2.11 per cent in 273 cycles studied, with 89 per cent of the cycles within the acceptable range (25 - 35 days). Levels of estradiol after an initial rise were maintained between 50-100 pg/ml and, d-norgestrel levels were relatively constant between 1.8-3 ng/ml during the period while the ring remained in situ. Clinical acceptance was good. The main problem encountered was of spontaneous expulsion of the ring in the toilet, which might be due to the squatting toilet habits of Indian women and laxity of vaginal wall.

Alkaline Phosphatase↗
PubMed1981

Effects of nitrous oxide and oxygen on tracheal tube cuff gas volumes.

The changes in the volume of the cuffs of 200 air-inflated tracheal tubes were studied on exposure to 70% nitrous oxide and 30% oxygen. The length of the cuff, its diameter, wall thickness and residual volume were measured. Increases in the volume of gas occurred in all tubes in a time-dependent manner. The tracheal tubes with low-pressure cuffs were more permeable to nitrous oxide and oxygen than those with high-pressure cuffs. Implications of these findings and the factors which govern the transmission rates of gases through cuff material are discussed.

Intubation, Intratracheal↗