Search PubMed⌕ Search

Biomedical subjects

S Batra

Publications and source records attributed to S Batra.

At least 217 records · Page 12Linked to original sources
PubMed1976

Unconjugated estradiol in the myometrium of pregnancy.

By chemically digesting myometrium in a mixture of NaOH and sodium dodecyl sulphate, estradiol could be recovered almost completely by extraction with ethyl acetate. The concentration of estradiol-17beta (E2) in the extracted samples could reliably be determined by radioimmunoassay. Compared to its concentration in the plasma, E2 in the pregnant human myometrium was very low, and as a result, the tissue/plasma estradiol concentration ratio was less than 0.5. In the pseudopregnant rabbit, this ratio ranged between 16 and 20.

Animals↗
PubMed1976

Uterine norepinephrine levels as related to plasma and tissue progesterone in pseudopregnant rabbits.

Pseudopregnancy was induced in rabbits by a single iv injection of 100 IU of human chorionic gonadotrophin (hCG). Uterine norepinephrine, located exclusively in adrenergic nerves, was markedly reduced (fluorometric determinations) during the first 6 days of pseudopregnancy and then returned towards pre-injection values. Plasma progesterone (measured by radioimmunoassay) was found to be elevated at days 3,6, and 12 of pseudopregnancy as compared to the very low values of the untreated controls. Although tissue progesterone also increased during pseudopregnancy (fourfold at day 6), there was a somewhat paradoxical relationship between plasma and tissue progesterone. In spite of unchanged plasma levels, tissue progesterone decreased considerably between days 6 and 12. The uterine/plasma progesterone ratio was very high (approximately 28) in non-pregnant (control) animals and ranged between 1 and 3 during pseudopregnancy. These results suggest that there is a causal relationship between the high levels of progesterone in the uterus and the reduced amount of norepinephrine transmitter in the adrenergic nerves in this organ, and that plasma progesterone concentration and the changing progesterone receptor levels regulate uterine progesterone concentration.

Animals↗
PubMed1976

Levels of free and protein-bound progesterone in plasma during late pregnancy.

Using a filter method, levels of free (unbound) and protein-bound progesterone in blood samples were measured serially from the 23rd week of pregnancy until delivery in 16 healthy women. In addition, total estrogen and progesterone concentrations were determined by radioimmunoassay. The levels of both free and total progesterone increased steadily until the end of pregnancy. Free progesterone increased with advancing pregnancy more in proportion to the total progesterone, as it rose from 6% (of total) at week 24 to 13% at week 40. Both free and total progesterone decreased markedly very soon (2 h) after delivery. However, the corresponding decrease in the level of free progesterone was considerably less, with the result that it rose to 19% of the total, the greatest proportion of free progesterone observed at any time. The levels of both total estrogen and progesterone in plasma increased with advancing pregnancy, and at no time, prior to delivery, was there a significant fall in progesterone or an abrupt rise in estrogen.

Blood Proteins↗
PubMedDate not supplied

Isoproterenol induced rat endomyocardial damage in relationship to local capillary geometry.

Isoproterenol (2 mg/kg) injected subcutaneously into male Sprague-Dawley rats elicited morphological damage in the endomyocardium which was analyzed 16 h following injection. Our aim was to study the relationship between damaged individual myocytes and their capillary supply. Myocardial tissue sections were differentially stained in order to distinguish arteriolar (AC) and venular (VC) capillary portions. Tissue areas surrounding individual capillaries and the position of the capillaries with respect to the damaged individual myocytes were established by using the method of "capillary domains". In multicellular necrotic lesions 84% of the capillaries located within the necrotic foci and 77% of the capillaries in the surrounding tissue area were identified as the distal, venular portion with presumably low O2 content. The proportion of VCs related to necrotic lesions was significantly higher than in surviving endomyocardial regions. In the case of individual necrotic myocytes, we found 88% to be supplied by VCs, while the adjacent normal myocytes were supplied by 61% VCs. Both values were significantly higher when compared to control hearts (42%). These results strongly support the crucial role of a lack of oxygen delivery in the pathogenesis of isoproterenol-induced necrosis.

Animals↗
PubMedDate not supplied

Serum TNF-alpha and free radical scavengers in neonatal septicemia.

Tumor necrosis factor-alpha (TNF-alpha) and free radicals have been implicated in the pathogenesis of neonatal septicemia and its complications. This case control study was conducted between November 1996 to July 1997 to determine the levels of TNF-alpha and free radical scavengers viz. superoxide dismutase (SOD) and glutathione peroxidase (GPX) in the serum of 30 septic neonates and 20 healthy controls. Patients with neonatal sepsis registered significantly higher levels of TNF-alpha, SOD and GPX in comparison to controls (p < 0.05). The neonates with septic shock had five fold increase in TNF-alpha levels (2262 +/- 605.8 pg/ml) as compared to those without shock (738.8 +/- 728.8 pg/ml). There was no statistically significant difference in levels of antioxidant enzymes between neonates with shock and without shock. The levels of TNF-alpha and antioxidant enzymes were not affected by the type of organism isolated in blood culture.

Case-Control Studies↗
PubMedDate not supplied

Changes in anti-oxidant enzymes and lipid peroxidation in hyaline membrane disease.

This study was conducted to elucidate the changes in key antioxidant enzymes e.g. Superoxide dismutase (SOD), Catalase and Glutathione peroxidase (GPx) along with lipid peroxidation (LPO) in preterm newborns having hyaline membrane disease (HMD) and thus to find out role of free radicals mediated injury in this disease. Twenty one preterm appropriate for gestational age newborns were included in the study. Eleven of them had hyaline membrane disease and ten were controls without any disease. Status of superoxide dismutase, glutathione peroxidase and catalase, the three main antioxidant enzymes and lipid peroxidation was monitored at 12-24 hours of age. SOD and catalase were found significantly elevated in cases having hyaline membrane disease along with significantly more lipid peroxidation. It is evident that free radicals result in the induction of the antioxidant enzymes; however, the elevated enzymes are unable to counteract the high concentration of the free radicals which are being produced in the diseased cases and leads to increase in lipid peroxidation in hyaline membrane disease. It is concluded that free radicals play a significant role in hyaline membrane disease and the preterm newborns have ability to induce antioxidant enzymes in response to oxidative stress.

Catalase↗