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Biomedical subjects

R Hemmings

Publications and source records attributed to R Hemmings.

At least 37 records · Page 2Linked to original sources
PubMed1994

Dysfunctional uterine bleeding in adolescents.

This retrospective, multicenter analysis was conducted on all adolescents admitted to three pediatric hospitals in Montreal, Quebec, Canada, over a 10-year period (1981-1991) with a primary diagnosis of dysfunctional uterine bleeding. The purpose was to assess the frequency of underlying medical disorders and their response to medical therapy. Sixty-one patient charts were identified. Newly diagnosed hematologic abnormalities were found in two patients (one with immune thrombocytopenic purpura and one with acute promyelocytic leukemia). Furthermore, all patients who were evaluated had normal factor VIII levels, partial thromboplastin times and prothrombin times. Twenty-nine percent of the patients had a past history of a significant medical problem. The mean age at presentation was 13.8 +/- 2.1 (SD) years. More than 50% of the patients had a history of irregular bleeding. Most patients (93.4%) responded to medical management. Only five (8.2%) required dilation and curettage. The history of irregular cycles, the early presentation after menarche, the infrequency of hematologic problems but high frequency of significant medical problems led us to conclude that the etiology of dysfunctional uterine bleeding in adolescence is often related to persistent immaturity of the hypothalamic-pituitary-ovarian axis. Medical therapy is highly effective in controlling such bleeding. Dilation and curettage is rarely required.

Administration, Oral↗
PubMed1993

Effects of synthetic growth hormone-releasing factor in women treated with gonadotrophin.

To evaluate the effects of synthetic growth hormone-releasing factor (GRF) in women with idiopathic infertility who were treated with human menopausal gonadotrophin (HMG), 13 women with this condition were randomly assigned to undergo treatment with HMG-GRF (500 micrograms twice daily) or HMG-placebo. Conception occurred in four of six women (14 cycles) who received HMG-GRF and in one of seven women (22 cycles) who received HMG-placebo. No difference was found in the amount of HMG and the duration of HMG required to induce ovulation between the two groups of patients. The overall serum growth hormone and insulin-like growth factor I concentrations were higher in the GRF than in the placebo group. No difference was found in serum oestradiol or inhibin concentrations between the two groups. Our results suggest that in women with idiopathic infertility, administration of GRF does not decrease the duration or the amount of HMG required to induce ovulation. However, it appears that in this small group concomitant treatment with GRF increases the pregnancy rates in women who are treated with HMG (4/14 cycles compared with 1/22 cycles).

Adult↗
PubMed1993

Embryonic resistance to tumour necrosis factor-alpha mediated cytotoxicity: novel mechanism underlying maternal immunological tolerance to the fetal allograft.

The cytokine tumour necrosis factor-alpha (TNF alpha) has been postulated to play an essential role in the cytotoxic activity of cell-mediated immunity against allogenic or tumour cells invading the host. Several tumour cell lines, however, are resistant to TNF mediated cytotoxicity and respond paradoxically by cellular proliferation and by autocrine secretion of TNF alpha. In view of the metastatic character of the mammalian embryo, the aim of this study was to assess the potential of murine embryos to secrete TNF alpha in vitro, to express TNF receptors and to resist TNF alpha mediated cytotoxicity during their in-vitro development to the blastocyst stage. The potential of human embryos to secrete TNF alpha in vitro until the blastocyst stage was also investigated. From a total of 11 human embryos, which were allowed to proceed to blastocyst formation, seven secreted TNF alpha in the range of 2-117 pg/ml/24 h. A total of 123 C57BL/6J mouse embryos were studied of which 55% secreted TNF alpha in the range of 1.25-3.95 mg/ml/24 h. The presence of high levels of exogenous TNF alpha (10-300 IU) was not detrimental to the in-vitro development of murine embryos. Using immunohistochemical techniques, we were not able to detect the presence of type I or II TNF receptors on the surface of murine embryos. Our findings suggest that human and C57BL/6J murine embryos have the potential to secrete TNF alpha in vitro during the developmental stages leading to blastocyst formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Distribution of lysophospholipids and metabolism of platelet-activating factor in human follicular and peritoneal fluids.

The distribution of lysophosphatidylcholine, lyso-platelet-activating factor and platelet-activating factor (PAF) was studied in human plasma and in follicular and peritoneal fluid. In plasma, peritoneal and follicular fluids, 51%, 87% and 89%, respectively, of the total lipids were found in the protein fraction (the density > 1.21 fraction). Two forms of lysophospholipids were identified in this fraction: one of high affinity and one of low affinity for albumin. The metabolism of PAF in human follicular fluid, peritoneal fluid and plasma was also investigated. PAF-acetylhydrolase activity was found in both peritoneal and follicular fluids which induced a time-dependent hydrolysis of [3H]PAF. The half-life of PAF was estimated to be 7-12 min in plasma, 15-25 min in peritoneal fluid and approximately 2 h in follicular fluid. PAF-acetylhydrolase activity in embryo culture media supplemented with 10% serum was markedly inhibited by addition of commercial serum albumin. When 25 g albumin l-1 was added, 22% of [3H]PAF was hydrolysed h-1 compared with 72% in media without albumin. The concentrations of lysophosphatidylcholine measured in plasma, in follicular and peritoneal fluids were 252, 286 and 53 mumol l-1, respectively. The distribution of these lysophospholipids and the metabolism of PAF in the female genital tract fluids reported in the present study provide evidence for the involvement of these biologically active lipid mediators in a variety of reproductive processes including sperm-egg interactions and embryonic development.

Albumins↗
PubMed1993

Platelet-activating factor acetylhydrolase activity in peritoneal fluids of women with endometriosis.

OBJECTIVE: To investigate whether platelet-activating factor acetylhydrolase may play a role in the pathophysiology of endometriosis. METHODS: Peritoneal fluids were obtained at laparoscopy from eight fertile women without endometriosis and 12 women with mild endometriosis. Platelet-activating factor acetylhydrolase activity was assayed in serum and peritoneal fluid by the release of 3H-acetate from [3H]-platelet-activating factor during a 15-minute incubation. RESULTS: Platelet-activating factor acetylhydrolase activity (mean +/- standard error of the mean) was significantly lower (P < .01) in peritoneal fluids from women with mild endometriosis (29.5 +/- 2.7%) than in controls (39.9 +/- 3.4%). The platelet-activating factor acetylhydrolase-cholesterol and -albumin ratios were also significantly lower in peritoneal fluids of women with endometriosis compared with controls (P < .006 and P < .012, respectively). CONCLUSION: These data suggest that mild endometriosis is associated with decreased platelet-activating factor acetylhydrolase activity in peritoneal fluid.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed1993

Recurrent pancreatitis associated with in vitro fertilization.

BACKGROUND: We report the possible association between in vitro fertilization (IVF) and recurrent acute pancreatitis. CASE: A patient developed acute pancreatitis during each of two cycles of IVF. On a spontaneous cycle, serum triglycerides were as follows: early follicular phase 2.34 mmol/L, mid-follicular phase 4.17 mmol/L, and late follicular phase 6.6 mmol/L. During an episode of acute pancreatitis, the serum triglyceride level was 38.45 mmol/L. CONCLUSION: Acute pancreatitis may occur in patients with a family or personal history of hypertriglyceridemia who are candidates for IVF.

Acute Disease↗
PubMed1992

Human embryos produce transforming growth factors alpha activity and insulin-like growth factors II.

OBJECTIVE: To assess whether growth factors are produced by early human embryos in culture. DESIGN: We studied various growth factors in the culture media of human embryos (n = 6) cultured from days 3 to 8 after fertilization. MAIN OUTCOME MEASURES: Four growth factors were measured: Insulin growth factors I and II (IGF-I and IGF-II), epidermal growth factor (EGF) and transforming growth factor alpha (TGF alpha) activity. RESULTS: Nonconditioned INRA Menezo B2 (Biomerieux, S.A., Paris, France) culture medium contained significant levels of TGF alpha activity (5.2 ng/mL) and low levels of IGF-I (1.02 ng/mL) and IGF-II (2.8 ng/mL), whereas EGF was below detection of our assay. With human embryo, the culture media contained lower TGF alpha activity on days 3 and 4 after fertilization (2.5 ng/mL and 2.8 ng/mL, P less than 0.05). From days 5 to 8 after fertilization, a significant increase in TGF alpha activity and IGF-II was detected (TGF alpha activity: day 5: 3.7 ng/mL; day 6: 4.4 ng/mL; day 7: 6.4 ng/mL; day 8: 8.4 ng/mL) (IGF-II: day 5: 3.4 ng/mL; day 6: 3.1 ng/mL; day 7: 4.1 ng/mL; day 8: 4.2 ng/mL). Epidermal growth factor was undetectable, and IGF-I did not vary significantly. CONCLUSION: Transforming growth factor alpha activity and IGF-II are produced by human embryos in culture at a time when they could play a role in morula to blastocyst transformation.

Analysis of Variance↗
PubMed1992

Peritoneal fluid inhibin during the menstrual cycle.

Serum and peritoneal fluid inhibin levels were measured by radioimmunoassay throughout the menstrual cycle in 14 women with endometriosis and in 16 controls. In controls, serum values (+/- standard error of the mean) increased from the early follicular phase (49.8 +/- 6.5 microLEq/mL) to the late follicular phase (178 +/- 37.8 microLEq/mL) and the luteal phase (346 +/- 98.3 microLEq/mL). Peritoneal fluid inhibin levels were several-fold higher than those in serum and reached a maximum value during the late follicular phase (early follicular: 2404 +/- 85 microLEq/mL, late follicular: 22,922 +/- 7145 microLEq/mL, luteal: 5195 +/- 1959 microLEq/mL). There was no difference in peritoneal fluid or serum inhibin concentrations between patients with and without endometriosis. These findings suggest that human gametes in the fallopian tube may be exposed to a very high concentration of inhibin. The lack of difference in inhibin concentrations between patients with and without endometriosis suggests that this hormone does not play a role in endometriosis-related infertility.

Adult↗
PubMed1990

Determination of insulin and insulin-like growth factors in the ovarian circulation.

Recent in vitro studies implicate the ovary as an extra-hepatic source of insulin-like growth factors (IGFs) with production regulated by gonadotropins and local steroids. Because previous studies have failed to show any significant variations in IGF levels in peripheral blood during the menstrual cycle, we measured the concentrations of IGF-I, IGF-II, and insulin in ovarian and peripheral venous blood samples obtained simultaneously from nine women undergoing abdominal hysterectomy to obtain more detailed data on the ovarian contribution. A significant decreased ovarian gradient was found for IGF-II but not for IGF-I or insulin. Although there was no significant ovarian vein insulin gradient, insulin levels were higher in follicular than in luteal phase ovarian samples. These data suggest that IGF-II may be locally regulated by the ovary. Both insulin and IGFs may regulate ovarian function in vivo.

Adult↗
PubMed1987

The Gollin incomplete figures test: a flexible, computerised version.

The Gollin incomplete figures test has been used as a measure of visual development, as a clinical test for parietal cortex dysfunction, and to examine long-term memory in amnesic patients. It has traditionally been administered by using a series of three or five stimulus cards, successive cards containing progressively more information. A study is reported in which digitised outline drawings of familiar objects were presented via a computer, the percentage of the figure on the screen slowly increasing from 0 to 100. The original findings of Gollin were successfully replicated; children's performance on the task improved markedly over the age range 2-5 years, and performance improved dramatically over three tests in all subjects. Computerisation of the Gollin task provides a precise and versatile alternative to the original card version.

Child Development↗
PubMed1985

Unilateral ovariectomy restores ovulatory cyclicity in rats with a polycystic ovarian condition.

An acyclic polycystic ovarian condition can be induced in adult rats with a single injection of estradiol valerate (EV). The ovaries are small and contain multiple cystic follicles and no new corpora lutea. In the early stages of the condition, both basal plasma luteinizing hormone (LH) and LH responses to luteinizing hormone-releasing hormone (LHRH) are attenuated. Plasma androgens are indistinguishable from normal controls. The present study examines the effect of unilateral ovariectomy (ULO) on this condition. Removal of one cystic ovary results in almost immediate resumption of vaginal cyclicity that persists for at least 3 wk. At 1 or 3 wk after ULO the remaining ovary contains fresh corpora lutea, appears histologically normal, and is significantly heavier than the cystic ovary removed at ULO, indicative of compensatory hypertrophy. Despite the resumption of apparently normal cyclic function, basal plasma LH concentrations and LH responses to LHRH are not significantly better than those in intact animals with polycystic ovaries. Thus, the previously polycystic ovary is fully capable of normal ovulatory function despite obvious impairments in the hypothalamo-pituitary axis. Since ovulatory function resumes on a background of continued poor pituitary responsiveness, the primary defect, which ULO corrects, is probably at the hypothalamic level. Finally, the cystic ovary clearly contributes to the hypothalamic aberration to which it subsequently responds.

Animals↗
PubMed1984

Carbon dioxide laser and electrosurgical wound study with an animal model: a comparison of tissue damage and healing patterns in peritoneal tissue.

This study was designed to compare the effect of wound healing after the use of the carbon dioxide laser and the electrosurgical unit on the peritoneal mesothelium of the New Zealand white rabbit. The biophysical parameters were held constant and identical in both groups. The effects were compared in terms of tissue damage, adhesion formation, and healing time. The animals were killed on days 0, 5, 10, 15, 20, and 25. Gross anatomic and histologic findings were recorded. The laser, when compared to the electrosurgical unit in this study, produced no adhesion formation and less tissue injury, immediately and throughout the healing phase (p less than 0.0039).

Animals↗
PubMed1983

Carbon dioxide laser treatment of vaginal adenosis in DES-exposed offspring: a prospective study.

Seventy-nine patients with history and physical findings characteristic of antenatal DES exposure were randomly divided into two groups. Fourty-four DES-exposed offspring had their vaginal adenosis treated with the carbon dioxide laser (group I), and the remaining 35 DES-exposed offspring (group II) did not receive any specific treatment for this condition. Additionally, the 79 DES-exposed offspring were compared to an age-matched control population (group III). Treatment of vaginal adenosis with the carbon dioxide laser did not significantly reduce the incidence of development of new dysplasia in the DES-exposed offspring. This study also showed no statistical difference (p less than or equal to 0.05) in the incidence of dysplasia in DES-exposed offspring as compared to a control population.

Adenocarcinoma↗
PubMed1983

Pituitary and ovarian responses to luteinizing hormone releasing hormone in a rat with polycystic ovaries.

Female rats injected with a single dose of 2 mg estradiol valerate (EV) develop anovulatory acyclicity characterized by persistent vaginal cornification and the formation of multiple large cystic follicles on the ovaries. In order to determine if these effects of EV are accompanied by changes in ovarian and/or pituitary function, the following studies were conducted. Ovarian androgen production was determined by the measurement at 4, 5 and 6 weeks after EV treatment of circulating dehydroepiandrosterone, androstenedione and testosterone. The capacity of the polycystic ovary to ovulate in response to luteinizing hormone releasing hormone (LHRH) stimulus was assessed. Ovarian histology was examined at the termination of the study (9 weeks after EV treatment). Pituitary function was assessed 9 weeks after the EV treatment by examining the acute changes in plasma luteinizing hormone (LH) concentration in response to a double pulse of LHRH. Plasma concentrations of the androgens were unchanged over the 3-week sampling period and were similar to those found in sesame-oil-treated normal cycling control rats. The ovaries from EV-treated animals were smaller than those of controls and the cystic follicles exhibited marked thecal hypertrophy and attenuation of the granulosa cell layer. The basal plasma LH concentration at 9 weeks after EV treatment were significantly lower than in proestrus controls and plasma concentrations of LH elicited by LHRH pulses was significantly lower than in controls. The relative increase in plasma LH following the LHRH stimulus was, however, greater in the EV-treated animals than in controls. In spite of the diminished LH surge elicited in response to LHRH, the EV-treated animals ovulated as indicated by the presence of fresh corpora lutea on the ovaries. These results indicate that androgens are not responsible for the polycystic ovarian condition in this system and that the polycystic ovary is capable of ovulatory function when appropriately stimulated.

Animals↗
PubMed1982

Effect of morphine on the hypothalamic-pituitary axis in postmenopausal women.

In this study, 10 postmenopausal women were given 5 mg of morphine intravenously; and the serum level of prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and growth hormone (GH) were measured before and after morphine injection. A significant increase in serum prolactin as well as a significant decrease in LH were observed following the administration of morphine. It is suggested that morphine may affect a common neurotransmitter that controls both prolactin and LH secretion. It is also of interest that the increase in serum prolactin following morphine injection is of similar magnitude as observed in premenopausal patients.

Female↗