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Biomedical subjects

S Basu

Publications and source records attributed to S Basu.

At least 469 records · Page 26Linked to original sources

Differential activities of glycolipid glycosyltransferases in Tay-Sachs disease: studies in cultured cells from cerebrum.

Four different glycolipid:glycosyltransferase activities involved in the biosynthesis in vitro of gangliosides and blood group-related glycosphingolipids have been tested in a simian virus 40-transformed glial cell culture derived from the cerebrum of a fetus with Tay-Sachs disease (TSD). The TSD cultured brain cells contained little activity of either UDP-Gal:GM2(beta 1-3)galactosyltransferase (GalT-3; EC 2.4.1.62), which catalyzes the formation of GM1a from GM2 (tay-Sachs) ganglioside, or GDP-Fuc:nLcOse4Cer (alpha 1-2)fucosyltransferase (FucT-2; EC 2.4.1.89), which catalyzes the formation of H1 glycolipid from nLcOse4Cer. These cells contained a potent inhibitor of the second reaction (catalyzed by a Golgi-rich membrane fraction from bovine spleen), whereas no inhibition of the first reaction (catalyzed by a membrane fraction from 14-day-old embryonic chicken brain) was observed. The activity of UDP-Gal:LcOse3Cer(beta 1-4)galactosyltransferase (GalT-4; EC 2.4.1.86) was 30- to 80-fold higher than the activity of GalT-3. The presence of CMP-AcNeu:nLcOse4Cer sialyltransferase activity and the absence of either GalT-3 or FucT-2 suggested a probable pathway for the synthesis of sialylneolactotetraosylceramide [GM1b(GlcNAc)] in addition to a specific blockage of GM1a ganglioside synthesis from GM2 in these TSD transformed cells.

ABO Blood-Group System↗

Second trimester abortion with 5% intraamniotic saline--a pilot study.

The risk of hypernatremia and related postabortion complications resulting from the intraamniotic administration of a 20-25% hypertonic saline solution, a widely used procedure all over the world, prompted this trial of 5% saline. Midtrimester abortion was induced in 150 women with a 5% saline solution administered intraamniotically at the National Medical College, Calcutta, India, from August 1974 to October 1975. The abortion was complete within 48 hours in 90% of the cases. All the fetuses were delivered dead. In one case, hysterotomy was performed because of severe bleeding. The immediate complication rate was 36% (12% serious). The follow-up complication rate was 2%. One patient died on the seventh postabortal day due to severe, uncontrolled septicemia. The authors conclude that because this procedure is simple and low cost and because it reduces the risk of hypernatremia it should be a welcome addition to service programs in developing countries.

Abortion, Induced↗

Evaluation of 496 menstrual regulation and abortion patients in Calcutta.

From March to December 1975, 496 patients were studied to compare the safety and effectiveness of menstrual regulation (MR) performed with a Karman hand syringe and first trimester abortion performed with an electric vacuum aspirator. All procedures were done on an outpatient basis. The complication rate for the MR patients was significantly lower than that for the other first trimester abortion patients. Study results indicate that MR with the Karman syringe is a safer, simpler and less costly procedure than first trimester abortion with the electric vacuum aspirator. Further research and study are necessary to determine the effect of the initial and repeat MR procedures on women's menstrual patterns and future pregnancies, including any subsequent prematurity, stillbirths and Rh immunization.

Abortion, Induced↗

Biosynthesis in vitro of fucose-containing glycosphingolipids in human neuroblastoma IMR-32 cells.

Two different glycolipid:fucosyltransferase activities involved in the biosynthesis in vitro of blood group-related glycosphingolipids have been detected in a membrane preparation isolated from a human neuroblastoma-derived clonal cell line, IMR-32. The membrane preparation contains an alpha (1,2)-fucosyltransferase (EC 2.4.1.89) that catalyzed the transfer of vucose from GDP--[14C]fucose to neolactotetraosylceramide or neolactopentaosylceramide to form types H-I and B-I glycolipids, respectively. The second fucosyltransferase catalyzes the transfer of fucose to lactotriaosylceramide [GlcNAc(beta1-3)Gal(beta1-4)Glc-Cer] to form a tetraglycosylceramide intermediate of the novel Lea-type glycolipid. UDP-galactose:lactotriaosylceramide beta-galactosyltransferase (EC 2.4.1.86) had 4 times the activity of UDP-galactose:alpha-galactosyltransferase (EC 2.4.1.87) when tested under similar conditions. alpha-Fucosyltransferase activities and the incorporation of [14C]fucose into glycoproteins and glycolipids were also compared in cells differentiated in the presence of 4 micron BrdUrd and 6-mercaptoguanosine.

ABO Blood-Group System↗

DNA polymerase activities in differentiating mouse neuroblastoma N-18 cells.

The activities of two DNA polymerases (DNA nucleotidyltransferases) were characterized in mouse neuroblastoma clone N-18 on the basis of their apparent molecular weights (determined by sucrose density gradient centrifugation: polymerase-alpha, 7.5-8 S; polymerase-beta, 3-4 S) and relative inhibition by sulfhydryl-blocking agents. N-Ethylmaleimide (10 mM) and iodoacetamide (1.5 mM) inhibited DNA polymerase-alpha activity completely, whereas only 35-40% inhibition was observed for DNA polymerase-beta under similar conditions. DNA polymerase-alpha activity was reduced 50-70% in N-18 cells that had been induced to differentiate by 4 micro M bromodeoxyuridine, and the low molecular weight DNA polymerase-beta activity remain unchanged. With activated calf thymus DNA as template, only DNA polymerase-alpha activity was stimulated in the presence of added ribonucleotides and purified Escherichia coli RNA polymerase.

Bromodeoxyuridine↗

Phage-typing of Salmonella weltevreden based on lysogeny. I. The phage-typing system.

All of the 1070 strains of Salmonella weltevreden tested were lysogenic, temperate phage being demonstrable in 83.9% of the strains in broth culture, 6.4% in mixed culture and the remaining 9.7% after induction by UV-irradiation and MC treatment. A phage-typing scheme for Salmonella weltevreden based on the host range of temperate phages was developed. The strains could be classified into eight groups by means of the host range of their temperate phages on six indicator strains and a ninth group, the symbiotic phages of which failed to lyse any of the indicator strains.

Bacteriophage Typing↗

Phage-typing of Salmonella weltevreden based on lysogeny. II. Epidemiological usefulness of the system and geographical distribution of its phage-types.

Nine hundred and forty-six strains of Salmonella weltevreden isolated in different states of India during 1958-1974 and 124 strains from Australia, Burma, Holland, Hong Kong, New Zealand, Papua New Guinea, the Philippines, Thailand, the United States and Vietnam during 1953-1971 were phage-typed according to the phage-typing scheme described in the first part of this paper (Sood and Basu, 1977). The epidemiological incidence and geographical distribution of phage-types of Salmonella weltevreden were studied. All the phage-types were present in India, the predominant phage-types being b, d and i. Phage-type g was isolated exclusively from India. All the 14 strains from Hawaii belonged to phage-type i. Phage-type h was the most predominant phage-type in Vietnam. The 15 strains isolated from Papua New Guinea in 1965, which were supposed to have originated from a single source, belonged to 3 phage-types. Except these cultures all the available epidemiologically related strains were of uniform phage-types - a finding which establishes the epidemiological validity of the scheme.

Animals↗

Embryonic chicken brain and mouse neuroblastoma cells N1E-115 and N-18 contain an inhibitor of acid deoxyribonuclease.

Activity of a trypsin-sensitive acid deoxyribonuclease (DNase) inhibitor has been detected in 13- to 21-day-old embryonic chicken brains and in clonal lines of neuroblastoma cells (adrenergic, N1E-115, and neurotransmitter-inactive, N-18) grown for 48 hr after subculture. The activities of purified porcine and bovine spleen DNases were inhibited 60--75% in the presence of the inhibitor, whereas less than 10% inhibition was observed with purified pancreatic DNase. Activities of an acidic DNase and its inhibitor reached maxima in 21-day-old embryonic chicken brain. The proteins were separated by isoelectric focusing and affinity column chromatographic techniques. The pI values of the acid DNase and its inhibitor were 5.4 and 4.2, respectively.

Animals↗