Biomedical subjects

H S Sharma

Publications and source records attributed to H S Sharma.

At least 181 records · Page 10Linked to original sources

PubMed1987

Cloning and sequence analysis of a cDNA encoding poly-ubiquitin in human ovarian granulosa cells.

A cDNA clone, pHGR21 encoding poly-ubiquitin, was isolated from a human ovarian granulosa cDNA library. This clone contained three complete, and part of a fourth, ubiquitin coding sequence joined head to tail with no spacer sequences. Northern analysis employing a restriction fragment comprising a complete ubiquitin coding unit indicated the existence of two mRNA species of 1.1kb and 2.8kb. Sequence comparison of pHGR21 with the known two human ubiquitin genes revealed differences to the human ubiquitin-3 repeat gene but significant homology to the human ubiquitin-9 repeat gene. The untranslated 3'-region and the adjacent ubiquitin coding repeat were found to be identical to that of the human ubiquitin-9 repeat gene. The other 3 ubiquitin coding repeats were of close homology to the fourth ubiquitin coding repeat of the human ubiquitin-9 repeat gene. These findings suggest the existence of yet another human poly-ubiquitin gene.

Base Sequence↗

PubMed1987

Biochemical development of the rat lung: studies on cellular DNA, RNA and protein content in relation to maternal vitamin A status.

The effect of maternal vitamin A restriction on the biochemical development of the lung in rats has been studied. The vitamin A status of dams has been varied by supplying low, medium and adequate amounts of vitamin A (6, 40 and 100 micrograms retinol/day/kg body weight, respectively) during pregnancy and suckling. The results demonstrate that the restricted supply of vitamin A to the mother affected the growth and development of the lung in parameters of tissue weight, DNA and protein levels and their biosynthesis from respective labelled precursors, RNA contents, cell number and cell size.

Aging↗

PubMed1987

Distribution of vitamin A in various organs of rats in relation to the quality and the quantity of dietary proteins.

The influence of the quality and the quantity of dietary proteins on the distribution of a single massive dose of vitamin A in various organs of growing Wistar strain rats has been studied by using casein and bengal gram diets at 20% and 10% protein levels. The distribution of [3H]-retinyl acetate in various tissues was also investigated in these dietary conditions. The results show that the hepatic storage of dietary as well as a single massive dose (20,000 I.U.) of vitamin A was profoundly decreased in the rats fed on bengal gram diets as compared to those fed on casein diets. Regardless of hepatic stores, the plasma vitamin A levels were comparable in all the groups. Feeding of low quality of protein reduced the tissue distribution of [3H]-retinyl acetate in control as well as rats given a massive dose of vitamin A. This study suggests that both the poor quality and the inadequate quantity of dietary protein are detrimental influences on the vitamin A status of the growing rats.

Animals↗

PubMed1987

Effect of captopril (a converting enzyme inhibitor) on blood-brain barrier permeability and cerebral blood flow in normotensive rats.

Intracarotid (10 mg/kg), intracerebroventricular (100, 200 micrograms) or topical application (0.8 M) of captopril (a converting enzyme inhibitor) increased the permeability of the blood-brain barrier to Evans blue albumin (EBA) and [131I]sodium in anesthetized normotensive rats. The permeability of the blood-brain barrier to albumen in 6 and to [131I]sodium in 10 out of 14 regions of the brain was increased in the perfused hemisphere after infusion of captopril into the right carotid artery. These regions of the brain were associated with a 54-107% increase in regional cerebral blood flow (CBF). Pretreatment with indomethacin and aprotinin prevented both the increased regional permeability of the blood-brain barrier along with regional cerebral blood flow. Pretreatment with vinblastine prevented only the regional increase in permeability of the blood-brain barrier. The regional cerebral blood flow continued to remain high. The probable mechanism(s) underlying the increased cerebral blood flow and permeability of the blood-brain barrier after infusion of captopril is discussed.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed1987

An mRNA encoding poly-ubiquitin in porcine corpus luteum: identification by cDNA cloning and sequencing.

A cDNA library derived from a particular fraction of mRNA of porcine corpus luteum was screened by hybrid-release. cDNA clone pCL208 selected an mRNA which, in cell-free translation, directed the synthesis of a major polypeptide of 28 kD. Sequence analysis of clone pCL208 revealed that the entire coding sequence contained three complete repeats and a fourth incomplete repeat of porcine ubiquitin, joined head-to-tail without any spacer peptide sequences. The ultimate ubiquitin molecule contained a Phe residue as a carboxy-terminal extension. The coding sequence terminated with the stop codon TAA followed by a short untranslated region, the polyadenylation signal AATAAA, and a tract of A residues. Northern analysis indicated the presence of two types of ubiquitin-specific mRNAs, i.e., 1100 and 2500 bp, in porcine corpus luteum.

Amino Acid Sequence↗

PubMed1987

In vitro secretion and uptake of radioactive vitamin A in rats fed different dietary proteins.

Generally, protein energy malnutrition is accompanied with vitamin A deficiency. The present study was undertaken to evaluate the importance of the quality and the quantity of dietary proteins on the in vitro secretion and uptake of vitamin A in growing rats. The results show that the in vitro release of radioactive vitamin A was greater in rats fed Bengal gram diets as compared to those fed casein diets. However, this relationship between the two groups of rats was reversed for the in vitro uptake of radioactive vitamin A from plasma by various extrahepatic tissues. Thus the vitamin A status of the animal is profoundly influenced by the quality and the quantity of dietary proteins.

Animals↗

PubMed1987

Molecular cloning and expression of a synthetic DNA coding for the antimicrobial protein of bull seminal plasma.

A DNA carrying the coding sequence for the antimicrobial protein from bull seminal plasma (SAP) was obtained by enzymic ligation of six synthetic oligonucleotides. The 162 bp synthetic DNA fragment was cloned into the C-terminal part of the lacZ-gene employing the vector pUR289. Expression in E. coli in the presence of the inducer isopropylthiogalactoside (IPTG) led to the formation of a fusion protein, which was shown by immuno-blotting to contain immuno-reactive antimicrobial protein. Approximately 90 min after induction, the cells stopped growing and the culture was found to contain no viable cells 3 h after induction. We conclude from this observation that the beta-galactosidase-antimicrobial protein fusion product was toxic for the E. coli cell and that the SAP-residue attached to beta-galactosidase was responsible for the cytotoxicity.

Animals↗

PubMed1986

Influence of long-term immobilization stress on regional blood-brain barrier permeability, cerebral blood flow and 5-HT level in conscious normotensive young rats.

Eight hours immobilization stress in young rats has increased the blood-brain barrier (BBB) permeability in 12 out of 14 brain regions studied. In the same regions cerebral blood flow (CBF) diminished by 2-37%, but the magnitude of flow reduction was not correlated with the degree of increased BBB permeability. On the other hand, a correlation was observed with increased plasma and brain 5-HT levels. The increased BBB permeability and increased 5-HT levels were prevented by pretreatment with p-CPA, indomethacin and diazepam. Cyproheptadine and vinblastine pretreatment prevented the occurrence of increased BBB permeability alone. The probable mechanism(s) underlying the breakdown of BBB permeability is discussed.

Animals↗

PubMed1986

Probable involvement of 5-hydroxytryptamine in increased permeability of blood-brain barrier under heat stress in young rats.

Exposure of young rats (9-10 weeks) to chronic summer heat (36 degrees C) or acute heat (38 degrees C, 4 hr) increased the permeability of the blood-brain barrier (BBB) to Evans blue albumin complex and [131I]sodium in different regions of the brain, which correlated well with the increased level of 5-hydroxytryptamine (5-HT) in plasma and brain. This increased permeability of the blood-brain barrier and the increased level of 5-HT were prevented by pretreatment with para-chlorophenylalanine (p-CPA), indomethacin and diazepam. Pretreatment with cyproheptadine and vinblastine, however, prevented only the increased permeability of the blood-brain barrier; the plasma and level of 5-HT in brain continued to remain high. These results indicate a probable role of 5-HT as one of the factors leading to the increased permeability of the blood-brain barrier in young rats following heat stress.

Aging↗

PubMed1986

Postnatal distribution of vitamin A in liver, lung, heart and brain of the rat in relation to maternal vitamin A status.

The effect of low, medium and adequate vitamin A (6, 40 and 100 micrograms/day/kg body weight) supplementation to the dams was studied on the accumulation of vitamin A in various tissues of the rat during postnatal growth. The restricted supply of vitamin A to the mother resulted in an impaired growth of pups and their organs. The maternal hepatic stores of vitamin A were related to their vitamin A intake, being lowest in the low group and highest in the adequate group during their fetal development. The plasma vitamin A levels of dams were comparable in three groups at birth and on 10th day of postnatal age. The vitamin A contents of fetal hepatic and extra-hepatic tissues (lung, heart and brain) were increased with the age of pups and this increase was observed to be dependent on the supply of vitamin A to the mother.

Animals↗

PubMed1985

Developmental pattern of the hepatic DNA, RNA and protein in relation to maternal vitamin A status in rats.

The effect of maternal vitamin A restriction on the biochemical development of fetal liver in rats has been studied. Vitamin A status of the dams has been varied by supplying low, medium and adequate (6.40 and 100 micrograms retinol equivalents/day/kg body weight respectively) amounts of vitamin A during pregnancy and suckling. The restricted supply of vitamin A to the mother resulted in the impaired growth and development of fetal liver in the parameters of tissue weight, DNA, RNA and protein levels, cell number and biosynthesis of DNA and protein from 3H-thymidine and 3H-leucine respectively. Results also indicated a dose dependent effect of vitamin A on the metabolism of DNA, RNA and protein in the developing liver.

Aging↗

PubMed1984