Biomedical subjects

J Kushari

Publications and source records attributed to J Kushari.

6 recordsLinked to original sources

PubMed1984

Action of polyamines on ribonucleic acid and protein synthesis during ontogeny of human fetal liver.

A higher rate of RNA synthesis in human fetal liver cells was found during the early age of gestation, after a drop, it gradually increases to a maximum value between 18 and 22 weeks, followed by a sharp decrease at later period of gestation. Total polyamine content of fetal liver tissue shows a similar trend. However, when liver cell suspension was incubated with exogenous spermine, spermidine and putrescine there is a dose-dependent inhibition in RNA synthesis. Protein synthesis in human fetal liver cells was stimulated with lower doses of spermine, spermidine and putrescine and inhibited at higher doses. The optimum dose for stimulation and the degree of stimulation was, however, not the same for fetuses of different gestational ages.

Fetus↗

PubMed1982

Occurrence of phosphodiesterase IV in the developing human brain, liver and placenta.

The presence of phosphodiesterase IV has been demonstrated in the human fetal brain, liver and placenta as early as in the 6th week of intrauterine development. The enzyme activity in each tissue increases with gestation, being maximum at 18-21 wk and then decreases. The Km values of this enzyme for bis-(p-nitrophenyl)-phosphate hydrolysis in the brain, liver and placenta are 2.94 mM, 1.47 mM and 1.66 mM, respectively. Presence of sulfhydryl group in the active center of the placental enzyme has been demonstrated with the help of cationic study. EDTA inhibits the enzyme in all three tissues. Effect of concanavalin A reveals the absence or unexposition of glucose, mannose and N-acetylglucosamine moieties in the active site of the enzyme in each of the three tissues. Maximum enzyme activity has been found to be localized in the soluble supernatant fraction obtained on centrifuging the brain and liver homogenate at 105,000 x g and in 20,000 x g pellet of the placenta.

3',5'-Cyclic-AMP Phosphodiesterases↗

PubMed1982

Biochemical studies on acid phosphatase in human placenta and fetal liver during development.

Activity and a few physiochemical properties of acid phosphatase (ACP) have been studied in different subcellular fractions of developing human placenta and fetal liver. The enzyme activity is discernible in all subfractions of each tissue already in the 6th week of gestation. The activity of the hydrolase in 20,000 g pellet, 105,000 g pellet and in 105,000 g supernatant of the placenta and in all fractions of the liver increases significantly with advancement of pregnancy until 26 weeks and declines in term placenta. However, 800 and 10,000 g pellets of the placenta show a gradual decrease in ACP activity with progression of gestation. Experiment with different inhibitors reveals that each tissue contains at least two types of ACP--a soluble one and a sedimentable one. It appears from the Lineweaver-Burk plot of kinetic study that sedimentable form has low Km and high Vmax values. Ag+, Cu++, Hg++, Co++ and Zn++ are inhibitory, while Fe++ and EDTA are stimulatory to the enzyme. The effect of different detergents, particularly with sodium deoxycholate and Triton X-100, shows the increase of the hydrolase activity, indicating 'latent nature' of the enzyme.

Acid Phosphatase↗

PubMed1981

Effect of medroxyprogesterone acetate contraception on human serum enzymes.

Activities of five enzymes were determined biochemically in the serum of a woman taking the injectable contraceptive, depo-medroxyprogesterone acetate (DMPA), 150 mg every 3 months for 2 years. The specific activities of SGOT, SGPT, and alkaline phosphatase (AP)-the enzymes commonly discerned in tests on the function of the liver-do not show any change with long-term treatment of this steroid contraceptive. Activities of serum acid phosphatase (ACP) and acetylcholinesterase (AChE) in red cells show significant increase. DMPA contraception has no apparent harmful effect on liver function, although the rise in ACP and AChE activities may be related to some pathological condition.

Acetylcholinesterase↗

PubMed1980

Studies on beta-glucuronidase of the developing human placenta.

Subfractional activities and some properties of Beta-glucuronidase were studied at different ontogenetic stages of the human placenta. Maximum activity was localized in the 105,000 g supernatant of tissue homogenate. THe enzyme activity in all fractions increased gradually, being maximum in the placentas of 22-26 weeks of gestation. At term, Beta-glucuronidase activity had diminished to a great extent. The enzyme showed considerable stability after heating at 65 C for 10 min. The Km value of this enzyme for p-nitrophenyl-Beta-D-glucuronide was 1.02 mM. EDTA inhibited placental Beta-glucuronidase. Of the cations tested, Ag+, Fe++ and Co++ were stimulatory, while Zn++ was inhibitory to the enzyme. Only one isoenzyme of Beta-glucuronidase was found in human placenta.

Female↗

PubMed1980

Comparative studies on acid phosphatase isozymes of developing human placenta and fetal liver.

Acid phosphatases from human placenta and fetal liver during ontogenic development have been studied by electrophoresis on polyacrylamide gels. Three isozymes have been detected in liver as well as in early and term placenta, and one more in placenta at mid-gestation. These isozymes behaved differentially towards heat and a number of inhibitors at different weeks of gestation. Quantitative determination of each isozyme also showed stage-specific variation.

Acid Phosphatase↗