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Biomedical subjects

J Kaur

Publications and source records attributed to J Kaur.

At least 91 records · Page 5Linked to original sources
PubMed1991

Analysis in vitro of uterine estrogen receptor conformation of young and old rats.

The conformation of estrogen receptor (ER) and its in vitro transformation by RNase, Urea and ATP were analysed using the uteri of young (16 weeks) and old (92 weeks) rats. Following the digestion of ER with proteolytic enzymes like trypsin and chymotrypsin and the analysis of cleaved fragments by SDS-PAGE, similar pattern is observed in both ages. In vitro transformation of ER by RNase, Urea and ATP shows that the degree of transformation is lower in old than young. Furthermore, the transformed ER from old is less capable of binding to DNA than that from young. Thus our results show that the conformation of ER probably does not change with age, but the degree of transformation and the ability of transformed receptor to bind to DNA decrease with age.

Adenosine Triphosphate↗
PubMed1991

Organomercury(II) complexes of 6-thioguanine: synthesis, characterization, and biological studies.

Organomercury(II) complexes involving 6-thioguanine, of the type p-XC6H4HgL (Fig. 1) [LH = 6-thioguanine; X = Me, MeO, NO2], have been synthesized and characterized. Conductance measurements indicate that the complexes are nonelectrolytes. From IR and UV studies, it is concluded that 6-thioguanine acts as a bidentate ligand, coordinating through the 6-thione group and deprotonation of N-7. 1H and 13C NMR support the stoichiometry of the complexes. From thermal studies (TG and DSC) various kinetic and thermodynamic parameters for thermal degradation have been enumerated. In addition, the fragmentation pattern of the complexes have been analyzed on the basis of mass spectra. The p-MeC6H4HgL and p-MeOC6H4HgL complexes display significant activity against L1210 leukemia cells.

Animals↗
PubMed1991

Evaluation of the ability of a new long-acting androgen ester to maintain accessory gland function in castrated rhesus monkey.

The ability of 40 mg of milled suspension of a new long-acting androgen ester (20 Aet-1) to restore and maintain accessory gland function was compared with that of testosterone enanthate (TE) in castrated adult rhesus monkeys. Castration did not abolish the ejaculatory response since only two animals did not void semen in the postcastration period. A single intramuscular injection of 40 mg of these compounds stimulated accessory gland function at levels lower than in the pretreatment period. 20 Aet-1-induced stimulation of prostatic acid phosphatase activity never exceeded control levels unlike that induced by testosterone enanthate which caused hyperstimulation on day 21 of drug treatment. In terms of support of accessory gland function, 20 Aet-1 would appear to offer hope of being a successful androgen for supplementation therapy in male animals.

Acid Phosphatase↗
PubMed1991

In vitro organ culture of rhesus monkey epididymal tubules.

The caput and cauda epididymal tubules of rhesus monkey were cultured for 5 days using a simple organ culture system. The viability of the tubules in culture was established by assessing: (a) the histology of the epididymis; (b) motility and viability of spermatozoa; and (c) scanning electron microscopic morphology of spermatozoa before and at the end of culture. The efficacy of the culture was evaluated by introducing the antiandrogen, cyproterone acetate, into the culture medium. Cyproterone acetate caused degenerative changes in the histology of the epididymis and coiling of the epididymal spermatozoa which may be due to alterations in epididymal milieu.

Androgen Antagonists↗
PubMed1991

Effect of age on physico-chemical properties of the uterine nuclear estrogen receptors of albino rats.

Estrogen receptors (ER) were extracted with high ionic strength buffer from the nuclei of uteri of young (21 weeks) and old (89 weeks) rats. Following the analysis of these receptors on a sucrose gradient and a Sephadex column, two peaks representing the two forms of receptors were obtained. The minor peak sedimented at 6.8 S with Stokes radius (RS) = 7.2 nm, molecular weight (Mr) = 204 K and frictional ratio (f/f0) = 1.71. On the other hand, the major peak sedimented at 4.1 S with RS = 3.3 nm, Mr = 57 K and f/f0 = 1.18. These properties of nuclear ER were similar in both ages. Also, the half life of ER complexes from both ages at 25 degrees C and 37 degrees C were 135 min and 30 min, respectively. However, these complexes were retained for longer periods in the nuclei of young than old rats. Furthermore, the dissociation constant of the binding of nuclear receptors to estrogen remained constant, but the number of binding sites decreased from 1.56 in young to 1.05 pmol/mg DNA in the old. In young rats, about 61% of nuclear receptors bound to DNA-cellulose. Out of this 2/5 was eluted with 0.15 M and the remaining 3/5 with 0.5 M KCl. On contrary, only 37% of total receptors bound to DNA-cellulose in the old. Out of this 3/5 was eluted with 0.15 M and the remaining 2/5 with 0.5 M KCl. These data suggested that despite the similarity in different physicochemical properties, the number of estrogen binding sites and the retention time of ER complexes in nuclei and the ability of these complexes to bind to DNA decrease in the uterus of old age.

Aging↗
PubMed1991

Effects of feeding low protein diet with and without leucine supplementation on protein status of lactating females and their pups.

Female rats were fed low protein diet (10% casein) either as such or supplemented with 3% leucine during pregnancy and lactation. Changes in litter size and the survival rate, growth and protein status of the pups were noted. The milk yield and hepatic and mammary gland protein status of the mothers were also studied. Feeding low protein diet reduced litter size, increased their mortality and resulted in poor growth of the pups. It also resulted in poor hepatic and mammary gland protein status of the mothers, as well as reduced their milk yield. On adding 3% leucine to 10% casein in the diet, the changes observed in the low protein group, did not alter in any manner.

Animals↗
PubMed1991

Enzyme immunoassay of phagocytosis stimulating tetrapeptide "tuftsin" in normal and leprosy sera.

The serum concentrations of the phagocytosis stimulating the tetrapeptide, tuftsin, were determined by competitive enzyme immunoassay in borderline tuberculoid/tuberculoid (BT/TT, 16 cases), borderline lepromatous/lepromatous (BL/LL, 16 cases), and in healthy controls (20 cases). Using checkerboard titration, 10 ng/well of diphtheria toxoid-p-aminophenylacetyl tuftsin (DTPT) conjugate when incubated with tuftsin antisera at 1:15,000 dilution with a preincubation time of 60 min with the competitor (tuftsin) followed by a further 60-min incubation onto the DTPT-coated wells gave consistent results with a sensitivity of 5 ng/well tuftsin. The mean serum tuftsin concentration was significantly lower in BL/LL patients (134.42 +/- 48.7 ng/ml, p less than 0.01) than in healthy controls (262.86 +/- 59.8 ng/ml), while BT/TT sera (210.94 +/- 75.5 ng/ml) showed slightly decreased levels than did normals, which was not statistically significant. The mean serum IgG levels in BL/LL and BT/TT patients (37.26 +/- 10.99 mg/ml; 28.08 +/- 6.57 mg/ml, respectively) showed significantly (p less than 0.001) higher concentrations than did healthy controls (12.3 +/- 3.6 mg/ml). These observations on the serum concentrations of tuftsin and IgG in leprosy individuals suggest that there is splenic dysfunction in BL/LL patients in terms of the processing of leukokinin to release the free, active molecule tuftsin.

Binding, Competitive↗
PubMed1991

Childhood psychopathology and temperament among slum dwelling children.

In this study we have identified the temperament and psychopathology among children between the age of 5 to 14 years. Out of the forty children selected for same thirty four of them belonged to parents who have less than primary education and earning less than Rs.1,000/- per month. Temperament and psychopathology is markedly high among the children belonging to these groups.

Adolescent↗
PubMed1990

Effect of post-synthetic modifications of proteins on the binding of estrogen-receptor complex to uterine nuclei of aging rats.

The binding of estrogen-receptor (ER) complex to nuclei following post-synthetic modifications of proteins was examined in the uteri of young (18 weeks) and old (96 weeks) rats. Acetylation decreases the binding of ER complex to nuclei but methylation shows no effect on the extent of binding in both ages. On the other hand, phosphorylation enhances the binding of ER complex by two-fold in nuclei from young rats but reduces this to half in nuclei from old rats. The pattern of binding in salt-resistant nuclear fractions is similar to that in total nuclei except in methylation where old rats show about 20% higher binding as compared to the respective control. These findings suggest that post-synthetic modifications of proteins modulate the binding of ER complex to uterine nuclei in an age-specific manner.

Acetylation↗
PubMed1990

Inhibition of spermatozoa maturation in rhesus monkey by cyproterone acetate.

The morphology of spermatozoa from the initial segment, caput, corpus and cauda epididymides of normal and cyproterone acetate-treated animals was studied using light and scanning electron microscopy to understand the changes taking place during spermatozoa maturation. A progressive and significant decrease in the percentage of spermatozoa that retained the cytoplasmic droplet and a shift in its position from proximal end of the midpiece to its distal end were seen during epididymal transit; these events were inhibited in cyproterone acetate-treated animals. A large percentage of spermatozoa from the initial segment and the caput epididymides showed coiling of the spermatozoa tail which involved the midpiece, principal piece and the endpiece. The percentage of spermatozoa that showed the coiled tail decreased; a gradual straightening of the spermatozoa tail with less complex types of coiling was also seen during epididymal transit. Cyproterone acetate reversed these changes occurring during maturation. These results indicate that spermatozoa maturation in the rhesus monkey, occurring between the corpus and cauda epididymides, is an androgen-dependent event.

Androgens↗
PubMed1990

Effect of non-aromatizable androgens on testicular and accessory gland functions in rhesus monkeys (Macaca mulatta).

Adult male rhesus monkeys were injected intramuscularly 100 micrograms, 1000 micrograms 5 alpha-androstane-3 alpha, 17 beta-diol or 100 micrograms dihydrotestosterone (DHT) per day for 70 days. A decrease in seminiferous tubular diameter was seen in treated animals. Androstanediol treatment disrupted spermatogenesis in most tubules. Sperm motility decreased within 40 days and by Day 70 non-motile spermatozoa were seen in 2 animals of each group treated with androstanediol. DHT treatment also decreased sperm motility progressively from Day 40. Both androgens caused retention of the cytoplasmic droplet and an increase in coiling of the tail of spermatozoa. Seminal fructose was decreased by Day 40 (1000 micrograms androstanediol) or Day 70 (100 micrograms androstanediol and 100 micrograms DHT). Seminal glycerophosphocholine (GPC) and acid phosphatase levels decreased by Day 70 in all treatment groups. Both steroids decreased circulating concentrations of testosterone without altering FSH or oestradiol values.

Androgens↗
PubMed1990

Kinetic properties of gamma-glutamyltranspeptidase and leucine-amino-peptidase in developing rat intestine: effect of hormones.

Administration of cortisone and thyroxine produced adult-type increase in the activities of soluble and membrane-bound gamma-glutamyltranspeptidase (gamma-GTP) in suckling rat intestine. Membrane-bound enzyme activity remained unaltered while the soluble enzyme activity was reduced (27%) in insulin-injected pups. Kinetic analysis revealed that the observed changes in the enzyme levels were a consequence of altered Vmax with no change in apparent Km. A 2-fold increase in the Km value was observed in adult gamma-GTP activity compared to that of suckling animals. Membrane-bound and soluble gamma-GTP yielded similar values of the Ea (9.7-13.1 kcal/mole) but exhibited apparent differences in heat stability in the control and hormone-injected groups. Leucine-amino peptidase(LAP) activity was reduced to adult levels in insulin-treated suckling animals. Thyroxine- and cortisone-treatment did not affect soluble activity but significantly (P less than 0.001) augmented the membrane-bound LAP levels. This increase was due to enhanced (54-82%) Vmax with no change in Km. The observed decrease in LAP activity in response to insulin was due to reduced Vmax. There was no change in Ea (8-11.6 kcal/mole) except the value was raised to 19.1 kcal/mole in cortisone-injected pups. Both the soluble and membrane-bound LAP activities were quite resistant to heat inactivation upto 30 min at 60 degrees C except in weanling rats. Thus, the kinetic behaviour of normally developed and precociously induced gamma-GTP and LAP is essentially similar but there are apparent differences in the mode of action of insulin, cortisone and thyroxine in affecting the development of these enzymes.

Animals↗
PubMed1989

Enterically transmitted non-A, non-B hepatitis: recovery of virus-like particles from an epidemic in south Delhi and transmission studies in rhesus monkeys.

An epidemic of viral hepatitis, serologically characterized as due to non-A, non-B hepatitis, occurred in a village of South Delhi, India, in December, 1986, through January, 1987. Water contaminated with fecal matter was the apparent source of infection. Disease-associated virus-like particles were detected by immune electron microscopy in the feces of three patients within 5 days of illness. The virus-like particles were agglutinated by autologous acute-phase serum but not by convalescent serum. Rhesus monkeys inoculated with particle-containing fecal suspensions developed biochemical and morphologic features of acute, self-limited hepatitis. The findings in the present study and in earlier investigations of sporadic non-A, non-B hepatitis suggest that (i) the epidemic form and a proportion of sporadic cases of this infection in India may be related, both being enterically transmitted and associated with infection by a 27- to 32-nm virus-like particle, (ii) antibody responses to this virus occur early in disease and are transient and (iii) the rhesus monkey may prove to be a suitable model for studies of epidemic non-A, non-B hepatitis.

Adolescent↗
PubMed1989

Effect of dihydrotestosterone on testicular and accessory gland function in male rhesus monkeys.

Pituitary, testicular and accessory gland functions were assessed at intervals of 10-20 days in adult male rhesus monkeys given 10, 100 or 1000 micrograms dihydrotestosterone (DHT). Circulating levels of LH and testosterone were suppressed. Ejaculated spermatozoa showed morphological abnormalities and decrease in motility but sperm counts were unaffected. Seminal fructose was decreased in animals receiving DHT. Sexual behaviour was maintained in these animals.

Acid Phosphatase↗