Biomedical subjects
Publications and source records attributed to M V Rao.
Bimonthly injections (im) of medroxyprogesterone acetate (MPA, 5 mg/0.2 ml) and testosterone enanthate (TE, 2.5 mg/0.2 ml) to rats for 30 and 60 days induced oligospermia. The sperms from epididymis had defective metabolism, alterations in their morphology, viability and acrosome integrity. Thus this altered sperm function resulted in reduction in the fertility rate of MPA+TE treated animals.
A positive cis-acting DNA element in the near 5'-upstream region of the CYP2B1/B2 genes in rat liver was found to play an important role in the transcription of these genes. An oligonucleotide covering -69 to -98 nt mimicked the gel mobility shift pattern given by the fragment -179 to +29 nt, which was earlier found adequate to confer the regulatory features of this gene. Two major complexes were seen, of which the slower and faster moving complexes became intense under uninduced and Phenobarbitone-induced conditions respectively. Minigene cloned DNA plasmid covering -179 to +181 nt in pUC 19 and Bal 31 mutants derived from this parent were transcribed in whole nuclei and cell free transcription extracts and mutants containing only upto -75 nt of the upstream were poorly transcribed. Transcription extracts from phenobarbitone-injected rat liver nuclei were significantly more active than extracts from uninduced rats in transcribing the minigene constructs. Addition of the oligonucleotide (-69 to -98nt) specifically inhibited the transcription of the minigene construct (-179 to +181 nt) in the cell free transcription system. It is therefore, concluded that the region -69 to -98 nt acts as a positive cis-acting element in the transcription of the CYP2B1/B2 genes and in mediating the inductive effects of phenobarbitone.
The interaction of two anthraquinone dyes, bromaminic acid 1-amino-4-bromo anthraquinone-2-sulphonic acid (BA) and 1-amino-4-(4'-aminophenylamino)-anthraquinone-2,3'-disulphonic acid (ASSO), with poly-L-lysine (PLL), poly-L-ornithine (PLO) and poly-L-arginine (PLA) has been studied. The flexibility of the side chain (chain length) and the geometry of the charge centre (tetrahedral/planar) of the polypeptide were found to affect the interaction. Further, both dyes induce ordered conformation (alpha or beta) for the three polypeptides, but the final conformation was found to depend on the polypeptide as well as the number of anionic sites on the ligand. While the bidentate ASSO-polypeptide complexes acquire beta-conformation, the monodentate BA distinguished between the three substrates and induces beta-conformation only for PLO.
This investigation suggests that the oxazolidine derivative of propranolol is a prodrug which is hydrolysed stereoselectively to propranolol by hepatic post-mitochondrial supernatant. The (S)-form of the prodrug is more stable in the biological system than its (R)-form.
Spermine induced B-Z transition of poly(dG-dC) in aqueous medium at and above physiological temperature, at cellular concentration levels in low ionic strength medium. The amine to phosphate ratio, A/P, at the midpoint of the transition decreases with increase in temperature. The enthalpy change was 45 +/- 8 kcal per mol of cooperative unit; the transition induced by spermine is highly cooperative with a cooperative unit length of 700 +/- 20 at 50 degrees C.
A single microdose (50 micrograms/50 microL) injection of sodium fluoride (NaF) into the vasa deferentia of adult male albino rats (Rattus norvegicus) caused arrest of spermatogenesis and absence of spermatozoa in the lumina of the seminiferous tubules of the testes, which consequently led to a decline in the sperm count in the caudae epididymides. Scanning electron microscopy of cauda and vas deferens sperm revealed deflagellation and tail abnormalities. This is probably related to the alterations in the internal milieu of these organs which rendered the spermatozoa immotile and consequently caused fertility impairment in the experimental animals. Thus microdoses of sodium fluoride were found to affect reproductive function and fertility rate.
Dexamethasone has a potentiating effect on phenobarbitone mediated induction of cytochrome P-450b + e mRNAs in adult rat liver. However, the glucocorticoid inhibits phenobarbitone-activated transcription of cytochrome P-450b + e mRNAs by 60-70%. This inhibitory effect is evident in run-off transcription of the endogenous genes as well as in the transcription of an added cloned gene fragment. Dexamethasone inhibits the phenobarbitone-mediated increase in the binding of a transcription factor(s) to the upstream region of the gene as evidenced by gel retardation and Southwestern blot analysis. The glucocorticoid does not stabilize the phenobarbitone-induced polyribosomal cytochrome P-450b + e mRNAs but appears to stabilize the nuclear transcripts. It is proposed that a negative element may mediate the action of dexamethasone at the level of nuclear transcription and stabilization of the nuclear transcript may account for the potentiating effect of the glucocorticoid on phenobarbitone-mediated increase in cytochrome P-450b + e mRNAs in the cytoplasm of the adult rat liver. However, the cytochrome P-450b protein levels are slightly lower in phenobarbitone + dexamethasone treatment than in phenobarbitone-treated liver microsomes.
The role of antioxidants, which are thought to scavenge the oxygen-free radicals in plants exposed to relatively low concentrations of ambient air pollutants for long durations, was studied for a year. Increases were observed in superoxide dismutase peroxidase activity, sulphate and leaf area to dry weight ratio, and decreases in stomatal conductance, ascorbic acid, protein content and total lipids, as a general response of all the plants in the polluted area. The results indicate that high peroxidase activity in the control plants and enhanced superoxide-dismutase activity in the polluted area might have enhanced the ability of Cassia siamea to tolerate stress better than Dalbergia sissoo. Similarly, enhanced activities in the polluted sites made Calotropis procera more tolerant of stress than Ipomoea fistulosa. Thus, it appears that monitoring of antioxidant activities offers a useful tool in understanding the mechanisms which make plants relatively tolerant in field conditions.
Conditions influencing production kinetics of bovine interleukin 2 (IL-2), viz. cell concentration, mitogen and its concentration, length of incubation, nutrient medium and in vivo antigen-priming were investigated. Peripheral blood mononuclear cells (PBL) of outbred cattle of different age groups showed considerable variation in their ability to secrete IL-2 which possibly reflects their immune competence. Of the cultures initiated with PBL, 5 x 10(6) cells/ml cultured in serum free Iscove's medium and stimulated with 5 micrograms Con A/ml for 24 hr produced maximal amount of IL-2 activity. In vivo antigen-priming of bovine lymphocytes with the live attenuated rinderpest virus revealed that IL-2 production was not affected by rinderpest virus but the in vivo antigen-priming possibly resulted in concomitant production of suppressor factor(s) which suppressed the already produced IL-2. The implications of this factor(s) in relation to regulation of immune responses in the disease process are discussed.
Serum levels of cortisol, T3, T4 and blood levels of glucose, lactate and pyruvate were measured 15 min before anaesthesia, 15 and 60 min after skin incision and at 2 h after surgery, in 16 patients undergoing elective surgery on lower extremities either under epidural analgesia (group I) or general anaesthesia (group II). The results showed that as long as the effect of epidural analgesia persisted, it could inhibit the increases in cortisol and blood glucose and the decreases in T3 levels, observed under general anaesthesia. This is probably because of the blocking effect of epidural analgesia on the afferent neurogenic impulses from the area of surgery. T4, lactate and pyruvate levels were not affected to any significant extent. These observations could be of value in the operative management of patients with diabetes mellitus and others with a high surgical morbidity.
The synthesis of cyclic di-, tri-, tetra-, penta- and hexa-thymidylic acids (16; n = 2, 3, 4, 5 and 6) and the cyclic hexadeoxyribonucleotide [d(CpCpTpApGpGp)], via the "filtration" approach, is reported. Some of the physical properties of the cyclic oligonucleotides are discussed, and their susceptibility to digestion in the presence of phosphorylytic enzymes has been studied.
In an in vitro investigation, methylmercury (MeHg) reduced the motility of rat spermatozoa probably by the inhibition of succinate dehydrogenase and ATPase activities. Concomitant morphological changes observed in the spermatozoa were coiled tails and kinks in midpiece and tail regions.
One hundred and fifty cases of Japanese encephalitis (JE) in children below 12 years of age admitted to the Headquarters Hospital, Bellary Medical College during October, 1986 to January, 1987 were studied. The youngest child affected was 1 year old. The ratio of male to female was 2:1. Hindu patients (93.33%) were significantly more than Muslim patients (6.6%). The average duration of illness prior to hospitalisation was 4.2 days (SD +/- 1.9 days). Fever, headache and/or vomiting were common presenting symptoms at the onset of illness. Onset of illness was acute or sub-acute in 105 cases (70%). CSF examination showed pleocytosis with lymphocytic reaction and normal sugar. Japanese encephalitis virus was isolated from the brain biopsy tissue in one case and the seropositivity rate for JE was 50%. The mortality was 26% and was directly related to younger age, longer duration of illness prior to admission and deeper grade of coma at the time of admission. Moderate to severe sequalae were seen in 31 patients (28.82%). The mean duration of hospital stay was 8 days.
Intramuscular administration of methylmercury (MeHg) into mice at doses of 10 and 20 micrograms per day and animal for 30 days exerts toxic effects on the epididymal histoarchitecture, sperm motility, sperm count and sperm energy metabolism. Scanning electron microscopic study showed changes in the cauda epididymal sperm morphology. All these factors contributed finally to a failure of the fertility in MeHg treated mice as evidenced by a significant reduction in the average number of implantation sites or their absence in females cohabited with treated males. The decline in the serum testosterone levels by high dose indicates a decreased testicular androgen synthesis.
Explore the source record for details and available documents.
Ryle's tube drainage of the afferent loop effectively prevented duodenal blow-out or anastomotic leakage in 40 patients undergoing partial gastrectomy for recurrent peptic ulcer. Similarly the same procedure was adopted in 20 cases of cholecystojejunostomy. The tube prevented anastomotic leakage and decompressed the biliary tree by effective bile drainage from the very 1st day thus favouring the prognosis. There was no complication observed directly related to either procedure in the present series.
Methylmercury (MeHg) treatment intramuscularly at doses of 10 and 20 micrograms separately/day/mouse for 30 days affected the weight of body and organs like testes, vas deferens and seminal vesicles in mice. Diminution of testosterone in serum was also associated with an accumulation of cholesterol in testes and reduction in seminal vesicle fructose. Altered spermatogenesis and Leydig cell morphology in testes and the changes in histoarchitecture of seminal vesicle and vas deferens indicated androgen deficiency in treated mice. Thus, the data suggested that MeHg administration to mice induced androgen deprived effect to target organs probably by blocking Leydig cell function.