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R H Asch

Publications and source records attributed to R H Asch.

At least 145 records · Page 8Linked to original sources
PubMed1984

Human sperm penetration in bovine cervical mucus clinical studies. II. Use of split ejaculates.

Sperm penetration through bovine cervical mucus was determined and correlated with the sperm characteristics in three fractions of the split ejaculate and in the whole ejaculate from 40 men of infertile couples in which a female cause of infertility had been ruled out. Sperm concentration and motility were found to be significantly higher in the first fraction (n = 40) as compared with the rest of the fractions and the whole ejaculate, whereas normal sperm morphology was not significantly different among the various fractions and the whole ejaculate. The bovine mucus penetration (BCMP) test was found to be normal in a significantly high percentage (58%) of samples of the first fraction as compared with the other two fractions (32% and 17%, respectively) and the whole ejaculate (35%) (n = 17). Moreover, in the first fraction of the split ejaculate, the results of the BCMP test were correlated significantly with sperm concentration (P less than 0.01), motility (P less than 0.0001), and morphology (P less than 0.02). The data demonstrate the superiority of the first fraction of the split ejaculate in terms of cervical mucus penetrability and sperm characteristics.

Adult↗
PubMed1983

Tolerance develops to the disruptive effects of delta 9-tetrahydrocannabinol on primate menstrual cycle.

Long-term exposure of sexually mature female rhesus monkeys (Macaca mulata) to thrice weekly injections of delta 9-tetrahydrocannabinol resulted in a disruption of menstrual cycles that lasted for several months. This period was marked by an absence of ovulation and decreased basal concentrations of gonadotropin and sex steroids in the plasma. After this period, normal cycles and hormone concentrations were reestablished. These studies demonstrate that in rhesus monkeys subjected to long-term treatment with delta 9-tetrahydrocannabinol tolerance develops to the disruptive effects of the drug on the menstrual cycle.

Animals↗
PubMed1983

Administration of agonistic and antagonistic analogues of LH-RH induce anovulation in Macaca fasicularis.

This study was designed to compare the effects of [N-Ac-D-Trp1,3, D-p-Cl-Phe2, D-Phe6, D-Ala10] (A-LH-RH), an inhibitory analogue, and D-Trp6-LH-RH, an agonist of LH-RH, administered to normally cycling cynomologous monkeys. Animals were divided into three groups (n = 5 each), each group receiving one of the following daily during the first 25 days of the menstrual cycle: 1) 20 micrograms of D-Trp6-LH-RH daily, 2) 1 mg of A-LH-RH, and 3) vehicle. Ovulation was established by serial laparoscopies and serum estradiol measurement. Controls presented normal cycles, as evidenced by ovulation day, luteal phase length and hormone levels. Ovulation was completely inhibited during drug administration in all animals of groups 1 and 2. Luteal phase length of all monkeys that ovulated was normal. The present data, therefore, not only show evidence for a consistent anovulatory effect of agonistic and antagonistic analogues of LH-RH in non-human primates, but also open a new approach for non-steroidal contraception.

Animals↗
PubMed1983

Predictive value analysis of measurements of human chorionic gonadotropin, pregnancy specific beta 1-glycoprotein, placental lactogen, and cystine aminopeptidase for the diagnosis of ectopic pregnancy.

The diagnostic utility of serum and urinary human chorionic gonadotropin (hCG) measurements and serum measurements of pregnancy-specific beta 1-glycoprotein (PSBG), placental lactogen, and cystine aminopeptidase (CAP) was prospectively studied in 51 consecutive patients with suspected ectopic pregnancy who underwent laparoscopy or laparotomy. CAP was not detected in the sera of any patient with ectopic pregnancy. False-positive results in each assay were found in patients with intrauterine pregnancy or missed abortion. The overall efficiency of the tests were: urine hCG slide test, 47%; urine hCG tube test, 80%; serum hCG, 86%; serum PSBG, 82%; and human placental lactogen, 60%. Although measurement of serum hCG by radioimmunoassay is the most accurate biochemical test in predicting the correct diagnosis in patients with suspected ectopic pregnancy, the relatively high efficiency of the urinary hCG tube test, coupled with its ease of performance, low cost, and rapid turnaround time, makes it the most practical screening test.

Aminopeptidases↗
PubMed1983

Platelets bind to rhesus monkey corpora lutea and stimulate its prostaglandin synthesis.

The in vitro production of different prostaglandins (PGs) was studied in rhesus monkey corpora lutea incubated with labeled arachidonic acid. The percentage of conversion of the arachidonic acid to all the PGs identified was similar, but the addition of platelet lysates caused at least a sevenfold stimulation of all PGs by the corpora lutea, the greatest stimulation in production occurring in the area corresponding to PGE2 and 15-keto-PGF2 alpha. Adipose tissue by itself produced more PGs than corpus luteum (CL); but, in contrast, such production was inhibited by addition of platelet lysates to the levels of conversion of the unstimulated CL. 125I-labeled platelets bound specifically to monkey CL, but not to adipose tissue. The interaction of the platelets with the CL in the formation of PGs may be of significance in the regulation of the luteal life span.

Adipose Tissue↗
PubMed1983

Assay for characterization of human follicular oocyte maturation inhibitor using Xenopus oocytes.

Human follicular fluid from healthy mature Graafian follicles and from pathologic ovarian cyst fluid was found to be inhibitory to progesterone-induced meiotic maturation of oocytes from the South African clawed toad, Xenopus laevis. Human follicular fluid but not human serum, collected from the same individuals, demonstrated a linear dose-response inhibition on the maturation of oocytes in the Xenopus assay system. These findings indicate that the human follicular and cyst fluids contain oocyte maturation inhibitor (OMI). This human OMI was inactivated when subjected to a boiling water bath for 2 min. The OMI action was shown to be reversible in its inhibitory action. The fact that OMI can act directly on the oocyte was demonstrated by its inhibitory action on maturation in defolliculated oocytes. The findings demonstrate that the inhibitory action of human OMI is not species-specific. Xenopus oocytes provide a simple, readily available, year-round bioassay material for testing follicular oocyte maturation inhibitor.

Animals↗
PubMed1983

Interactions of delta 9-tetrahydrocannabinol (THC) with hypothalamic neurotransmitters controlling luteinizing hormone and prolactin release.

The effects of delta 9-tetrahydrocannabinol (THC) on hypothalamic norepinephrine (NE) and dopamine (DA) turnover and hypothalamic serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIAA) and LHRH content preceding and during a progesterone- (P) induced LH and prolactin (PRL) surge were investigated in ovariectomized estrogen-primed rats. THC had no effect on basal LH levels, but it inhibited basal PRL levels and blocked the surges of both LH and PRL. The turnover of NE, as estimated by measuring NE depletion after inhibition of tyrosine hydroxylase with alpha-methyl tyrosine (250 mg/kg), in both the anterior (AH) and medial basal hypothalamus (MBH) was significantly inhibited by THC. THC did not significantly affect AH or MBH DA or 5-HT content nor MBH-DA-turnover. Hypothalamic LHRH levels were significantly elevated 4 h after THC administration as compared to the vehicle-injected controls, but pituitary response to exogenous LHRH was not affected. These data suggest that THC inhibits the steroid-induced positive feedback release of LH by reducing NE metabolism and the release of hypothalamic LHRH. Although the mechanism for the inhibition of PRL release by THC is not clear from these experiments, it does not appear that alterations in DA turnover are a contributing factor.

Animals↗
PubMed1983

Suppression of the positive feedback of estradiol benzoate on gonadotropin secretion by an inhibitory analog of luteinizing hormone-releasing hormone (LRH) in oophorectomized rhesus monkeys: evidence for a necessary synergism between LRH and estrogens.

Estrogens have a biphasic effect on gonadotropin (FSH and LH) secretion in human and nonhuman primates. Recent studies suggest that estrogens induce negative as well as positive feedback on gonadotropin secretion by a direct action at the pituitary gland. To further investigate the mechanism by which estrogens modulate gonadotropin secretion, the following experiments were performed. Oophorectomized rhesus monkeys were injected with estradiol benzoate (EB) at a dose of 40 micrograms/kg sc at zero time (controls). Three groups of animals received, additionally, an inhibitory analog of LRH, [Ac-D-p-Cl-Phe1,2, D-Trp3,D-Arg6,D-Ala10]LRH (200 micrograms, sc, daily) at 1) -48 to 48 h, 2) 0-48 h, and 3) 24-48 h from EB treatment, respectively. Blood was collected at -72, -48, -24, and 0 h, every 6 h from 6-84 h, and 96 and 116 h after EB; FSH and LH levels were measured by RIA. Control animals had a 70-80% decrease in baseline FSH and LH levels during the first 24 h after EB injection, followed by a sharp rise to 60-80% above basal levels 42-48 h post-EB. In contrast, animals that received the inhibitory analog of LRH in different regimens had more pronounced and prolonged negative feedback of EB on gonadotropin concentrations. The positive feedback release of FSH and LH was significantly diminished or delayed compared to control values. The results of this study indicate that this inhibitory analog of LRH potentiates the negative feedback and suppresses the positive feedback of EB on gonadotropins, suggesting that estrogens induce the secretion of FSH and LH through a mechanism that involves the action of LRH at the gonadotroph.

Animals↗
PubMed1983

Evidence for modulation of a 24K protein in human endometrium during the menstrual cycle.

The presence and distribution of a protein with a molecular weight of 24,000 (24K) was determined in endometrial biopsies from regularly cycling women. This protein, of as yet unknown function and originally found in a breast cancer cell line, was detected by immunohistochemistry using a monoclonal antibody. In the glandular epithelium, the 24K protein began to appear during the late proliferative phase and decreased after ovulation. In contrast, the strongest immunostaining was observed in the superficial epithelium during the secretory phase. In these cells, the 24K immunoactivity reached the maximum around day 21 of the cycle and was clearly seen in the bulbous projections of the apical cytoplasm. These results suggest that the 24K protein may be a marker for hormonal events during the menstrual cycle.

Cytoplasm↗
PubMed1983

Suppression of postovulatory gonadotropin levels does not affect corpus luteum function in rhesus monkeys.

The exact mechanism(s) of control of corpus luteum function remains unknown. To address the question whether luteinizing hormone (LH) plays an important role, the following experiments were performed in cycling rhesus monkeys. Experiment 1: 10 monkeys were followed for 2 consecutive cycles and ovulation data determined using serum estradiol (E2) measurements and serial laparoscopies. In the second cycle, starting on day 1 after ovulation, the animals received daily administration of a potent inhibitory LHRH analog, [N-Ac-D-Trp1,3,D-p-Cl-Phe1,D-Phe6,D-Ala10]-LH-RH (N = 5) or vehicle (N = 5) until the onset of vaginal bleeding. Serum FSH and LH concentrations declined significantly in animals treated with the antagonist. However, E2 and progesterone (P) levels were not different from vehicle-treated monkeys. Luteal phase length in both groups was unchanged from the control cycle. Experiment 2: the same protocol was followed, adding the administration of hCG in increasing dosages from days 6-10 after ovulation (Day 6 = 30 IU, Day 7 = 60 IU, Day 8 = 90 IU, Day 9 = 180 IU, Day 10 = 360 IU). The increase in serum P concentration was the same for both groups. These results suggest that significant suppression on gonadotropin levels after ovulation does not affect corpus luteum function and that the inhibitory analog does not have a direct effect on the ovary.

Animals↗
PubMed1983

The effects of marijuana extract and delta 9-tetrahydrocannabinol on luteal function in the rhesus monkey.

The effects of marijuana extract (ME) and delta 9-tetrahydrocannabinol (THC) on corpus luteum function were studied in the rhesus monkey by the use of in vivo and in vitro techniques. THC (2.5 mg/kg) or vehicle (3% Tween 80 in saline) was administered by an intramuscular injection to rhesus monkeys on day 20, 21, or 22 of the menstrual cycle. Progesterone (P) levels were measured at 6-hour intervals for the first 24 hours after treatment. THC caused a significant decrease in P levels during this 24-hour period. This decrease was reversed by the administration of human chorionic gonadotropin (hCG) at 6 hours after THC administration. When THC was administered 2 hours after hCG, it failed to inhibit the expected rise in serum P levels caused by hCG. Direct effects of the drugs on P production were studied with the use of dispersed luteal cells obtained from monkeys on day 21 or 22 of the menstrual cycle. Neither ME nor THC had any effect on basal P production in these in vitro studies. These data suggest that the inhibitory effect of THC on P levels during the luteal phase are not mediated by a direct effect of the drug on ovarian steroid production.

Animals↗
PubMed1983

Administration of luteinizing hormone-releasing hormone analogs delays ovulation without affecting the luteal function in rhesus monkeys.

Regularly cycling rhesus monkeys received, from days 1 to 6 of the menstrual cycle (1) the potent luteinizing hormone-releasing hormone (LH-RH) agonist D-Trp6-LH-RH, 20 micrograms/day; (2) the potent LH-RH antagonist [N-Ac-D-Trp1,3,D-p-Cl-Phe2,D-Phe6-D-Ala10]-LH-RH, 1 mg/day; or (3) vehicle. Whereas control animals showed normal menstrual cycles, as determined by dates of ovulation, length of luteal phases, and hormonal profiles, animals treated with either analog of LH-RH exhibited disruption of the cycles. In animals from both groups, delayed ovulation was observed (LH-RH agonist, 22, 23, 17, 19, and 20 days of the cycle; LH-RH antagonist, 22, 22, 24, and 10 days of the cycle, and one animal remained anovulatory for 65 days). Monkeys treated with either LH-RH analog showed normal luteal phase lengths (15, 15, 16, 14, and 15 days, and 15, 16, 16, and 13 days, respectively) and serum progesterone concentrations. The results of this study suggest that, in the rhesus monkey, the administration of LH-RH analogs during the early follicular phase induces a temporary cessation of folliculogenesis demonstrated by a delay of ovulation, with subsequent normal luteal function.

Animals↗
PubMed1982

Response of rhesus monkey lymphocytes to short-term administration of THC.

Four Rhesus monkeys were subjected to daily administration of 2.5 mg of tetrahydrocannabinol (THC)/kg body wt, after establishing the norms for complete blood count, T- and B-cell concentrations, and the dose response of thymidine incorporation after PHA stimulation. THC was administered daily for 3 weeks, the treatment was stopped, and then the animals were allowed to recover for 4 weeks. Cellular responses, incorporation studies and fibrinogen levels were determined during the treatment and recovery phases. Compared to 4 vehicle-treated animals, the THC-treated animals experienced significant augmentation of both their total white cell and their neutrophil counts during the recovery phase which returned to normal levels during the recovery phase. There was no alteration in total lymphocyte count or T- or B-cell concentrations. Fibrinogen levels of the THC-treated animals during the treatment phase were also elevated compared to controls, and the levels diminished to the same values as the vehicle-treated animals during recovery phase. Possible mechanisms for the response of Rhesus monkeys to short-term administration of THC are discussed.

Animals↗
PubMed1982

Effects of porcine follicular fluid on gonadotropin concentrations in rhesus monkeys.

The administration of steroid-free charcoal-treated porcine follicular fluid to long term castrated female rhesus monkeys lowered basal serum concentrations of FSH and had almost no effect on serum LH. Treatment with porcine follicular fluid before the administration of exogenous LRH inhibited the release of FSH, but also affected the release of LH. This inhibition was especially striking on the suppression of the peak of release of both FSH or LH at 20 min. These findings suggest that an inhibin-like material present in follicular fluid could play an important role in the secretion of FSH and LH in rhesus monkeys.

Animals↗
PubMed1982

Failure of indomethacin to block the estrogen-induced luteinizing hormone surge in the ovariectomized rhesus monkey.

Prostaglandins have been shown to be stimulatory to LH release in several species, although it is not known, in the primate, whether this effect is mediated through the hypothalamic-pituitary axis or by an indirect effect mediated through the ovary. In the present experiments, indomethacin, an inhibitor of prostaglandin synthesis, did not significantly alter basal LH levels or the positive and negative feedback effects of estrogen on LH release in the ovariectomized rhesus monkey. Therefore, it appears that the previously demonstrated effect of indomethacin on LH release in the intact monkey was mediated through ovarian mechanisms.

Animals↗
PubMed1982

Luteal function in hypophysectomized rhesus monkeys.

Experiments were designed to study the maintenance of corpus luteum function in the rhesus monkey. The experiments used a transfrontal microsurgical approach for total hypophysectomy. This proved to be a reliable and safe procedure for the complete removal of the pituitary gland. Luteal function was not affected by either complete hypophysectomy or sham surgery performed 1 day after ovulation. The concentrations of PRL in serum became undetectable during the luteal phase in hypophysectomized animals. Serum LH levels in the first postoperative cycle were detectable, but were just above the lower limits of sensitivity of the bioassay. Ovulation was induced with human menopausal gonadotropin and hCG or human menopausal gonadotropin and human LH at least 6 months after hypophysectomy, at which time endogenous LH was undetectable. These animals displayed normal luteal function, for approximately 10 days suggesting that the corpus luteum, once formed, can function independently of circulating LH and in the absence of the pituitary gland.

Animals↗
PubMed1982

Prevention of the postcoital luteinizing hormone surge by ultrashortloop feedback control.

Studies were designed to determine whether the ultrashortloop feedback (USLF) system could prevent the gonadotropin-releasing hormone (GnRH) stimulation and postcoital rise of luteinizing hormone (LH). Unanesthetized castrated female rabbits bearing chronically-implanted venous catheters were subjected to the following: (1) GnRH stimulation. Ten animals received intravenous (IV) bolus injections of 30 microgram GnRH. Two hours prior to GnRH, animals received either 2000 IU human chorionic gonadotropin (hCG) or saline. A second group of ten animals received 20 microgram GnRH. One hour prior to GnRH, an infusion of human luteinizing hormone (hLH) at 2.75 IU/min or of saline was started and continued over 4 hours. (2) Coital stimulation. Ten rabbits were studied with the use of natural coital stimulus. They received either 2000 IU hCG 2 hours before mating or saline as a control group. Both hLH infusion and hCG injection inhibited GnRH stimulation of LH secretion but did not modify the follicle-stimulating hormone (FSH) response. hCG inhibited the coitus-induced LH surge and did not modify coitus-induced FSH secretion. These studies demonstrate that USLF control of LH can modulate LH secretion under both pharmacologic and physiologic conditions.

Animals↗