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P Banerjee

Publications and source records attributed to P Banerjee.

At least 109 records · Page 6Linked to original sources
PubMed1990

Asymmetric extraction of membrane lipids by CHAPS.

We have characterized and quantitated the lipids which are cosolubilized with serotonin 5-HT1A sites from sheep brain using 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS). Dialysis of the CHAPS extract produced a [3H]8-hydroxy(2-di-n-propylamino)tetralin [( 3H]8-OH-DPAT) binding vesicular preparation of the protein. Quantitative analysis of the lipids present in the CHAPS extract by HPTLC and transmittance-densitometry revealed extraction of phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidyl serine (PS) and phosphatidic acid (PA) in striking preference over cholesterol, galactosylceramides, sulfatides and sphingomyelin. All lipids present in the clear CHAPS-extract were coeluted with the [3H]8-OH-DPAT binding preparation were separated by centrifugation, 95-100% of the [3H]8-OH-DPAT binding protein was retained in the vesicle-containing pellet. The supernatant contained small amounts of cholesterol, PE and PC, but virtually no PS, PI, or PA, whereas the vesicular pellet contained all the lipids mentioned, indicating that PS, PI and PA are more tightly bound to the vesicles than PE, PC and cholesterol. SDS-PAGE analysis of the pellet revealed two major protein bands, at 58 kDa and 33.5 kDa, respectively. Our report outlines a simple and improved densitometric assay used for the first detailed analysis of lipids cosolubilized with an active, membrane protein, and also, a simple assay for CHAPS.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1990

Molecular structure of a major insulin/mitogen-activated 70-kDa S6 protein kinase.

The molecular structure of a rat hepatoma 70-kDa insulin/mitogen-stimulated S6 protein kinase, obtained by molecular cloning, is compared to that of a rat homolog of the 85-kDa Xenopus S6 protein kinase alpha; both kinases were cloned from H4 hepatoma cDNA libraries. The 70-kDa S6 kinase (calculated molecular mass of 59,186 Da) exhibits a single catalytic domain that is most closely related in amino acid sequence (56% identity) to the amino-terminal, kinase C-like domain of the rat p85 S6 kinase (calculated molecular mass of 82,695 Da); strong similarity extends through a further 67 residues carboxyl-terminal to the catalytic domain (40% identity), corresponding to a region also conserved among the kinase C family. Outside of this segment of approximately 330 amino acids, the structures of the p70 and p85 S6 kinases diverge substantially. The p70 S6 kinase is known to be activated through serine/threonine phosphorylation by unidentified insulin/mitogen-activated protein kinases. A model for the regulation of p70 S6 protein kinase activity is proposed wherein the low activity of the unphosphorylated enzyme results from the binding of a basic, inhibitory pseudosubstrate site (located carboxyl-terminal to the extended catalytic domain) to an acidic substrate binding region (located amino-terminal to the catalytic domain); substrate binding is thereby prevented. S6 kinase activation requires displacement of this inhibitory segment, which is proposed to occur consequent to its multiple phosphorylation. The putative autoinhibitory segment contains several serine and threonine residues, each followed directly by a proline residue. This motif may prevent autophosphorylation but permit transphosphorylation; two of these serine residues reside in a maturation promoting factor (MPF)/cdc-2 consensus motif. Thus, hormonal regulation of S6 kinase may involve the action of MPF/cdc-2 or protein kinases with related substrate specificity.

Amino Acid Sequence↗
PubMed1989

Critical evaluation of conventional abdominal closure with single-layer closure in adult and elderly.

Two different techniques of abdominal closure, conventional and single-layer, were studied on comparative basis in 55 cases each. Single-layer closure was found to have definite advantage over conventional closure as regards operating or healing time, feasibility, ease and postoperative morbidity. Single-layer closure took 8-10 minutes in comparison to 18-20 minutes required by conventional method. Incidence of burst abdomen was found to be 3.6% in the former and 7.27% in the latter. In only one case of conventional closure incisional hernia occurred whereas none occurred in case of single-layer closure. Moreover complications of scar and delayed healing were less in single-layer closure.

Abdomen↗
PubMed1988

Solubilized glycosyltransferases and biosynthesis in vitro of glycolipids.

The assembly of most of the ceramide-linked glycolipids (GSLs) in eukaryotic cells occurs in Golgi bodies. At least 18 different glycolipid:glycosyltransferases (GSL:GLTs) have been characterized, 10 of which have been solubilized. These GLTs can be classified into 2 distinct groups: 1) GLTs dedicated to either Dol-P-P-sugar(s) or ceramide-linked sugar(s); and 2) GLTs with dual loyalties (i.e., they compete with glycolipid- and glycoprotein-bound oligosaccharides). Studies with solubilized and purified GalNAcT-1 and GalNAcT-2 from embryonic chicken brains prove that GalNAcT-1 (UDP-GalNAc:GM3 beta 1-4GalNAcT) is specific for GSL, whereas GalNAcT-2 (UDP-GalNAc:Gb3 beta 1-3GalNAcT) can transfer to an oligosaccharide containing the alpha-linked terminal galactose. Similarly, GalT-3 (UDP-Gal:GM2 beta 1-3GalT) is more specific for ganglio-oligosaccharide and GalT-4 (UDP-Gal:Lc3 beta 1-4GalT) can transfer galactose to N-acetylglucosamine linked to p-nitrophenol, glycolipid or glycoprotein. Both GalT-3 and GalT-4 have been separated and purified from embryonic chicken brains. Studies with solubilized SAT-4 and SAT-3, from bovine spleen and embryonic chicken brains, respectively, suggest the existence of 2 different gene-expressed alpha 2-3SATs. The newly discovered FucT-3 (GDP-Fuc:NeuGc-iLc6-alpha 1-3FucT) from human colon carcinoma (Colo-205) has also been solubilized and separated from other GSL:GLTs. Using a new activity gel-Western blot combined technique, the molecular mass of this FucT-3 was determined to be 105 kDa.

Animals↗
PubMed1984

In search of a super solution: controlled trial of glycine-glucose oral rehydration solution in infantile diarrhoea.

In a double blind trial a glycine fortified oral glucose electrolyte solution was evaluated in a group of infants and small children (n=25) with moderate to severe dehydration due to acute diarrhoea, and was compared with a matched control group (n=26) receiving only glucose based oral rehydration solution. It is seen that the diarrhoea stool output, duration of diarrhoea, and volume of oral rehydration fluid required to achieve and maintain hydration are significantly lower in the group receiving glycine fortified glucose electrolyte solution. The possibility of developing an oral rehydration solution which could also act as an absorption promoting drug is discussed.

Administration, Oral↗
PubMed1983

Ovarian steroids and modulation of morphine-induced analgesia and catalepsy in female rats.

The influence of ovarian steroids on modulation of antinociceptive and cataleptic responses to morphine in female rats was evaluated. The sensitivity of the animals to morphine varied at different stages of the estrous cycle. The responses of postpartum and ovariectomized rats to morphine was attenuated. The test doses of estradiol-17 beta or progesterone, either alone or in combination, did not alter this attenuated morphine sensitivity. Testosterone, however, sensitized post-partum as well as ovariectomized rats to morphine. Unlike progesterone, 17-alpha-hydroxy progesterone antagonized testosterone. Collectively these data implicate ovarian testosterone as a physiological modulator of actions of morphine in female rats.

Analgesia↗
PubMed1982

Possible physiological role of adrenal and gonadal steroids in morphine analgesia.

The effects of adrenal and gonadal steroids on the antinociceptive potency of parenteral morphine were studied in male rats. At all doses studied, dexamethasone pretreatment 30 min before morphine sensitized the animals to the effects of parenteral morphine. However, at higher doses of dexamethasone this sensitization was masked when dexamethasone was given 4 h before morphine by a cycloheximide-sensitive attenuating effect. This feature is not a specific glucocorticoid effect since testosterone showed similar characteristics. Estradiol-17beta and progesterone, however, produced only a cycloheximide-sensitive attenuating response at 4 h. Deoxycorticosterone on the contrary had a cycloheximide-independent attenuating influence with both pretreatment schedules. Results of the present study indicate that morphine subsensitivity after castration or supersensitivity after adrenalectomy may be attributed to the relative lack of testosterone or mineralocorticoid in the respective conditions. Furthermore, in view of the fact that testosterone plays a rate-limiting role in determining the morphine sensitivity of the animals and that mineralocorticoids exert their effects indirectly via antagonism of testosterone action.

Adrenalectomy↗