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Biomedical subjects

H S Juneja

Publications and source records attributed to H S Juneja.

67 records · Page 4Linked to original sources
PubMed1984

Abnormal marrow fibroblasts in aplastic anemia.

Human bone marrow fibroblasts (BMF) were grown in vitro from normal (N) subjects and patients with aplastic anemia (AA). Growth studies in vitro revealed that both the N-BMF and AA-BMF had a logarithmic growth phase of eight days. Population doubling time for six of the 12 N-BMF and seven of the 12 AA-BMF was greater than 50 h. Five of the 12 AA-BMF studied in contrast to only two of the 12 N-BMF had a population doubling time of less than 50 h. The remaining four N-BMF had a population doubling time of greater than 100 h. During a similar duration in the logarithmic phase of growth, the AA-BMF underwent an average of 2.499 population doublings in comparison to 1.586 doublings by N-BMF (P = less than 0.01). The AA-BMF grew in multiple layers compared with the N-BMF, which usually grew as a monolayer. At the end of the logarithmic phase of growth, the AA-BMF also had a significantly higher number of cells per dish than the N-BMF (P = 0.02 on analysis of variance and covariance). These data suggest that a subgroup of AA-BMF grows faster than N-BMF and that the AA-BMF lack cell-to-cell inhibition. Testosterone, 3 alpha-etiocholanolone, and dexamethasone at 1 X 10(-8)M concentration, a physiological concentration, stimulated the growth of N-BMF as evidenced by increase in cell numbers and radioactive thymidine (3H-TdR) uptake. While dexamethasone had a stimulating effect on growth of N-BMF, it suppressed the growth of AA-BMF. Specific binding of radioactive dexamethasone (3H-dexa) was determined both for the N-BMF and AA-BMF. Specific binding sites for dexamethasone (Bmax) present on the N-BMF ranged from 460 to 770 fmol/mg protein). Bmax for AA-BMF was low (27-215 fmol/mg protein). In addition, the dissociation constant (Kd) was ten times lower for AA-BMF (1.0 X 10(-7) M) than for N-BMF (1.1 X 10(-8) M). The observations on the growth studies, the paradoxical response to dexamethasone, and the difference in the number of binding sites for dexamethasone indicate that the marrow fibroblasts from patients with aplastic anemia are abnormal.

Anemia, Aplastic↗
PubMed1983

Bioassayable gonadotropin releasing hormone-like activity in the spent nutrient medium of rat sertoli cells in primary cultures.

Investigations were undertaken to demonstrate bioassayable GnRH-like activity in the spent nutrient medium of Sertoli Cells in Primary Cell Cultures (SCCM) using an in vitro bioassay procedure. The bioassay involved the use of intact pituitaries from day-12 male rats. Amounts of LH and FSH released into the incubation medium in response to varying doses of synthetic GnRH were measured by radio-immunoassays. SCCM was extracted with methanol and diethylether. The extracted SCCM was evaporated under a stream of nitrogen at 50 degrees C. The dry residue was re-suspended in the assay medium and centrifuged. The supernatant was used as the source of GnRH-like activity. The treated SCCM gave a dose response parallel to that given by synthetic GnRH. Boiling and trypsinization of extracted SCCM destroyed the GnRH-like activity. Addition of synthetic GnRH to different doses of extracted SCCM gave additive response.

Animals↗
PubMed1982

Effect of testosterone, estradiol-17 beta, and 5 alpha-dihydrotestosterone on inhibin production by sertoli cells in culture.

Inhibin activity in charcoal-extracted spent culture medium of Sertoli cells in Primary culture (CSCCM) was monitored by following the temporal inhibition of serum levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in normal adult male rats. Subcutaneous injection of CSCCM reduced LH and FSH levels within 15 min and maintained the inhibition up to 10 hr. No selective suppression of FSH was observed. The model was used to assess inhibin activity in CSCCM from Sertoli cell cultures incubated with 5 alpha-dihydrotestosterone (DHT), testosterone (T), and estradiol -17 beta (E2) (5 micrograms/ml) for 24 hr. CSCCM from T and E2 treated groups suppressed gonadotropins while the group exposed to DHT failed to elicit any inhibition. DHT seems to inhibit the release of inhibin by Sertoli Cells.

Animals↗
PubMed1982

Growth of human malignant micromegakaryocytes in vitro.

Mononuclear cells from the peripheral blood of a patient with megakaryoblastic transformation of Philadelphia chromosome-positive chronic myelogenous leukemia were cultured. Morphological and cytochemical studies and cell ploidy determinations were done daily for 4 days. PAS staining of the cells increased progressively during culture. Ultrastructural study of circulating and cultured cells revealed demarcation membranes and alpha granules indicating the cells were micromegakaryocytes. Deoxyribonucleic acid synthesis, determined by 3H-thymidine uptake, peaked at 72 hours. The DNA content of cultured cells was diploid at all times. All 15 metaphases analyzed at 72 hours were Ph1-positive. Malignant (Ph1-positive) megakaryoblasts and micromegakaryocytes grown successfully were capable of partial cytoplasmic maturation as demonstrated by glycogen deposition and increase in subcellular organelles, while endoreduplication was impaired. Malignant megakaryoblasts and micromegakaryocytes can be grown successfully in short term liquid culture and have more complete maturation in vitro than observed in vivo.

Cell Division↗
PubMed1981

Presence of the Philadelphia chromosome (Ph1) in pokeweed mitogen stimulated lymphocytes during chronic phase of chronic myelocytic leukemia (CML).

There has been a lack of direct cytogenetic studies on lymphocytes in the chronic phase of chronic myelocytic leukemia (CML). Peripheral blood mononuclear cells from seven patients in the chronic phase and on in the blastic phase of Ph1-positive CML were cultured in the presence of phytohemagglutinin (PHA) and pokeweed mitogen (PWM). Preparations adequate for analysis were obtained from eight PHA and five PWM stimulated cultures. Cytogenetic studies on the PWM stimulated cultured cells revealed, in one patient, the presence of the Philadelphia chromosome (Ph1) in 23/25 metaphases. The PHA stimulated lymphocytes from the same patient were all Ph1 negative. Lymphocytes from PHA and PWM stimulated cultures from the other six patients in the chronic phase and the one patient in blastic crisis were all Ph1 negative. The one positive result suggests that some B lymphocytes contain the Ph1 and that there is a common hematopoietic stem cell for B lymphocytes as well as the myeloid, erythroid, and megakaryocytic series.

B-Lymphocytes↗
PubMed1979

Changes in uterine phosphatase levels in mice deprived of LH during early pregnancy.

Mice injected with normal rabbit serum on Day 4 of gestation showed a progressive increase in specific alkaline and acid phosphatase activities on Days 6 and 7. Mice injected with antiserum to LH on Day 4 showed a significant decrease in specific alkaline phosphatase activity estimated biochemically on Days 6, 7 and 8, but this decrease was histochemically evident only on Day 8. Similarly, acid phosphatase activity in antiserum-treated mice was significantly increased on Days 6, 7 and 8 when estimated biochemically, but only on Day 8 when studied histochemically.

Acid Phosphatase↗
PubMed1969

Studies on metabolism of vitamin A. The effect of hormones on gestation in retinoate-fed female rats.

1. Female rats, raised to maturity on a vitamin A-deficient diet supplemented with retinoate as the sole source of vitamin A, conceived when allowed to mate with normal males, but the conception resulted in foetal resorption, beginning from day 14 or 15 of pregnancy. 2. Daily injections of pregnenolone or oestradiol-17beta, but not of progesterone, were fully effective, and transplantation of pituitary homografts under kidney capsules was 80% effective, in preventing resorption. 3. Unilateral ovariectomy, leading to compensatory hypertrophy of the remaining ovary, resulted in significantly fewer corpora lutea and in lower weight of the hypertrophied ovary of the retinoate-treated rats, as compared with the corresponding retinyl acetate-fed ones. 4. The activity of the enzyme system Delta(5)-3beta-hydroxy steroid dehydrogenase was significantly less in the ovaries of the retinoate-fed rats that were subjected to unilateral ovariectomy or were made pregnant, when compared with that of the corresponding controls. Also, the ovaries of the retinoate-treated rats were insensitive to both exogenous and endogenous gonadotrophin stimulus. 5. These results indicate that one of the reasons for foetal resorption in the retinoate-fed rats might be inadequate synthesis of steroid hormones such as pregnenolone and oestrogen.

Animals↗
PubMed1966

The effect of vitamin A deficiency on the biosynthesis of steroid hormones in rats.

1. The synthesis, both in vivo and in vitro, of various steroid hormones in the adrenals, testes and ovaries of rats was compared at various stages of vitamin A deficiency with the corresponding pair-fed controls. 2. The enzymic conversion of the Delta(5)-3beta-hydroxy steroids into the corresponding Delta(4)-3-oxo steroids was significantly decreased in these tissues even at the mild-deficiency stage, further loss taking place on prolonging the deficiency. 3. In all three tissues the loss in the production of androstenedione from dehydroepiandrosterone could be reactivated in vitro by retinol or retinoic acid, but only at the mild stage of the deficiency. 4. Of the various lipoidal materials tried, retinal, retinol, retinoic acid, alpha-tocopherol acetate, menadione, calciferol, lecithin, palmitic acid and cholesterol, only retinol and retinoic acid restored the lost activity. 5. Intraperitoneal injection of retinal, retinol or retinoic acid into the deficient rats, 24hr. before they were killed, corrected the effect of the deficiency on this reaction. 6. Vitamin A deficiency markedly affected the synthesis of deoxycorticosterone and corticosterone from pregnenolone in the adrenals of rats, even at the mildly deficient stage, with further loss taking place at the acute stage; in vitro, retinol or retinoic acid could restore the loss at the mild-deficiency but not at the acute-deficiency stage. 7. The deficiency had no such effect on the synthesis of deoxycorticosterone from progesterone or of corticosterone from progesterone or deoxycorticosterone. 8. Compared with the pair-fed normals, the adrenals of deficient rats contained smaller amounts of deoxycorticosterone and corticosterone.

Adrenal Glands↗
PubMedDate not supplied

Poor quality of sperm as it affects repeated early pregnancy loss.

A study was carried out to determine whether males contribute to repeated early pregnancy loss. Semen samples were analyzed from proven-fertile men (n = 51 group I) and from men whose partners presented with early pregnancy loss (>3 first trimester abortions, n = 32 group II). Routine analysis, sperm function tests, and ultrastructural studies of sperms were carried out. Female factor could be identified in 25 (78%) couples, and in 7 (22%) no cause either male or female could be identified and the semen analysis was normal. Percent morphologically normal did not differ significantly between the groups, but increased sperm head abnormalities were seen. The functional tests were all normal except for a significant decrease in the capacity of nuclear chromatin to decondense in vitro. The ultrastructural studies showed defects of chromatin condensation and irregular nuclei with vacuoles. This study points to the loss of chromatin integrity as a possible contributing factor from males to early pregnancy loss.

Abortion, Habitual↗
PubMedDate not supplied

Effect of chronic administration of Tamoxifen on fertility in male bonnet monkeys (Macaca radiata).

Administration of Tamoxifen via the Alzet pump at a rate of 50 micrograms hr-1 for 90 days in the adult male bonnet monkeys Macaca radiata had no effect on the serum testosterone concentration determined at 10 AM and 10 PM as well as total sperm count determined at 15-day intervals over a period of 260 days. However, a significant reduction in sperm motility was observed beyond 90 days up until the 225th day. Breeding studies conducted from day 90 to 260 revealed that these males were infertile.

Animals↗
PubMedDate not supplied

Effect of 5alpha-dihydrotestosterone implants on the fertility of male rats treated with tamoxifen.

In adult male rats, tamoxifen (TAM) reduces circulating levels of luteinizing hormone (LH) and testosterone (T) with no effect on follicle-stimulating hormone (FSH) and prolactin (PRL). It reduces the male rat's ability to inseminate the female (potency), as well as its siring ability (fecundity). The objective of the present study was to test whether androgen supplementation could reverse all or some of the observed effects of TAM. To obviate the effects of estrogen, the study was designed to evaluate the beneficial or deleterious effect of 5alpha-dihydrotestosterone (DHT), a 5alpha-reduced, nonaromatizable metabolite of T, on the reproductive functions of TAM-treated adult male rats. Adult male rats received either saline or TAM (0.2 or 0.4 mg per day p.o.) for 90 days. A group of TAM-treated rats was implanted with 6 mg DHT from day 50 to day 90. A third group of untreated animals was implanted with 0-, 1-, 3-, or 6-mg DHT implants for 90 days. Mating studies were done to assess the fecundity, potency, and fertility index at the end of the treatment. Weights of testes, pituitary, and accessory sex organs were recorded, and circulating levels of LH, FSH, PRL, T, and 17-beta-estradiol were estimated. DHT did not affect the fecundity or fertility index. TAM reduced fecundity, potency, and the fertility index. DHT implants improved the fertilizing ability of the TAM-treated male rat. This study discusses and reviews the role of T and 17-beta-estradiol in sperm-fertilizing potential in light of these observations.

Animals↗