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Biomedical subjects

V Hanf

Publications and source records attributed to V Hanf.

At least 37 records · Page 2Linked to original sources
PubMed1993

Cholinergic stimulation of progesterone and estradiol secretion by human granulosa cells cultured in serum-free medium.

Cholinergic effects on hormone secretion by human granulosa cells (GCs) are not well characterized. The aim of this study was to explore the direct action of acetylcholine and carbachol on progesterone and estradiol secretion of human GCs cultured in serum-free medium. Granulosa cells were obtained from 26 women undergoing in vitro fertilization and embryo transfer. Progesterone and estradiol production was measured in the presence and absence of acetylcholine, carbachol, or atropine using radioimmunoassays; statistical analysis of the data was performed by ANOVA. Acetylcholine significantly stimulated progesterone secretion by GCs in a dose-related manner. Estradiol secretion was also stimulated by acetylcholine, but this effect did not show dose dependency. Carbachol showed a similar stimulatory effect, but to a lower degree; both effects can be blocked by acetylcholine. The results suggest that cholinergic action on steroid production by human GCs is mediated through the muscarinic route, and cholinergic neurotransmission may have a physiological significance in the intra-ovarian regulatory pathways.

Acetylcholine↗
PubMed1993

The effect of histamine on progesterone and estradiol secretion of human granulosa cells in serum-free culture.

The aim of this study was to explore the direct action of histamine on progesterone and estradiol secretion of human granulosa cells cultured in serum-free medium. Human granulosa cells were isolated from preovulatory follicular fluid aspirated from 17 women (32 +/- 3 years old, mean +/- SD) undergoing in vitro fertilization treatment at the University Women's Hospital of Tübingen. Progesterone and estradiol production was measured in the presence and absence of histamine, terfenadine or cimetidine using radioimmunoassays. Statistical analysis of the data was performed by analysis of variance and Newmann-Keul tests. Histamine stimulated a dose-related increase in estradiol secretion with a maximal stimulatory effect at 10(-3) mol/l. This response was blocked specifically by the H1-receptor antagonist terfenadine. Progesterone production in response to histamine stimulation was independent of dose at the limit of significance. The specific H2-receptor antagonist cimetidine did not block the stimulatory effect of histamine. We suggest that histamine has a direct stimulatory effect on steroid production of granulosa cells mediated via the H1-receptor. This effect may have a physiological role in the regulation of granulosa cell function during the menstrual cycle.

Adult↗
PubMed1992

Loss of PAF-like activity from human embryo conditioned media (ECM) following HPLC separation.

Recently a platelet activating factor (PAF)-like activity has been found in embryo conditioned media (ECM) and consequentially been termed embryo-derived PAF (EPAF). Yet it remains unclear whether the embryo-released molecule is in fact PAF or a PAF precursor or inductor in vivo. In this study we shall show that ECM did not induce platelet aggregation in vitro; however, it was possible to detect PAF-activity using the sensitive splenectomized mouse bioassay (SMB). Following lipid extraction, PAF activity was diminished, and after additional HPLC separation completely lost. We propose that the active fraction of ECM is lipid in nature but that this molecule is not PAF. We would rather suggest that this molecule induces the production of PAF by other cell types in vivo.

Animals↗
PubMed1992

Influence of serotonin on progesterone and estradiol secretion of cultured human granulosa cells.

OBJECTIVE: To explore the direct action of serotonin on progesterone (P) and estradiol (E2) secretion of human granulosa cells cultured in serum-free medium. DESIGN: Progesterone and E2 production was measured in the presence and absence of serotonin, propranolol, or cycloheximide using radioimmunoassays; statistical analysis of the data was performed by ANOVA. SETTING: In vitro fertilization and embryo transfer (IVF-ET) for infertility treatment at the University Women's Hospital, University of Tübingen, Germany. PATIENTS, PARTICIPANTS: Fourteen women, 30 +/- 3 years old, undergoing IVF-ET. RESULTS: Serotonin stimulated a dose-related increase in P secretion with a maximal stimulatory effect at 10(-4) M. This response was blocked specifically by the beta-receptor antagonist propranolol (10(-4) M). Estradiol secretion in response to serotonin was dose-independent stimulation, which was highest at 10(-6) M and was inhibited by 10(-4) M propranolol. The protein synthesis inhibitor cycloheximide markedly reduced the stimulatory effect of serotonin on P secretion. Estradiol production in the presence of cycloheximide was significantly reduced; serotonin had no stimulatory effect under these conditions. CONCLUSION: Serotonin may have a physiological role in the corpus hemorrhagicum, when luteinization is initiated.

Adult↗
PubMed1992

[Modification of in vitro motility of human sperm by various dioxin congeners in super-physiologic concentrations].

Human ejaculate was fractionated using density gradient centrifugation. Highly motile spermatozoa were incubated with "superphysiological" concentrations of various dioxin congeners. Over a period of sixty hours, no relevant influence on sperm motility in comparison to control media was noted on triplicate testing. It therefore appears unlikely, that intravaginally ejaculated spermatozoa would be compromised in their motility by naturally occurring levels of dioxins in female genital tract secretions. However, this does not preclude the possibility of such dioxin levels affecting normal intratesticular spermatogenesis.

Dioxins↗
PubMed1992

Effect of LHRH and its analogues on the progesterone secretion of human granulosa cells in vitro.

Progesterone secretion of cultured human granulosa cells treated with LHRH or its analogues was measured. Granulosa cells were also stimulated with LH, FSH, cAMP or forskolin. No differences could be observed in the progesterone basal secretion of cultures treated with or without LHRH or its analogues and after the various stimulations. It was concluded that the clinical experience that the sensitivity of ovaries for gonadotropins after LHRH desensitization is decreased could not be explained with the peripheral effects of LHRH on the granulosa cells. From the data obtained, the lack of LHRH receptors in the ovaries are suggested in humans.

Female↗
PubMed1991

Effects of EPF treatment in human mononuclear cells.

Early Pregnancy Factor (EPF) is one of the earliest pregnancy associated signals, communicating the ensuing pregnancy to the maternal organism. Data published by others on the mouse suggest that EPF bound to spleen cells causes the release of two H2-restricted "suppressor factors" responsible for the rosette inhibiting activity of EPF in the rosette inhibition test. Using human material, we were able to detect the release of a second entity from mononuclear cells that is able to suppress rosette formation in the human rosette inhibition test. In an attempt to show an intracellular EPF effect in the target cell, cytosolic free calcium concentrations were measured in EPF-treated mononuclear cells from peripheral blood. Our findings did not, however, show any changes of intracellular free Ca(2+)-concentrations under the chosen conditions.

Calcium↗
PubMed1991

Comparison of the effects of HMG or pure FSH stimulation during suppression with an LHRH agonist analogue.

Infertile patients who responded poorly in an in-vitro fertilization programme were treated with human menopausal gonadotrophin (HMG) or with pure follicle stimulating hormone (FSH) during continuous administration of a luteinizing hormone-releasing hormone (LHRH) agonist, to determine whether a low level of LH is required for follicle maturation. No statistically significant differences were detected in the dose of gonadotrophins, duration of treatment, oestradiol and LH levels, numbers of recovered oocytes, transferred embryos or fertilization rates. It is concluded that an absence of low levels of LH does not disturb follicular development in the follicular phase. Based on the low fertilization rates in the present study (0.32 with HMG versus 0.45 with FSH) the authors suggest that, as well as hormonal deficiency, other factors may also influence follicular and early embryonic development.

Estradiol↗
PubMed1990

[Pregnancy and labor following liver transplantation].

We report on pregnancy and delivery in a patient following hepatic transplantation. After an uneventful gestation at term, a child of normal body weight was born. To the best of our knowledge only 7 successful pregnancies following hepatic transplantation have been reported, one of them in the Federal Republic of Germany. Amongst the publications mentioned there are only two further reports on an immunosuppressive drug regimen utilising cyclosporine plus prednisolone. We stress the importance of the following items: peripartual immunosuppression, analgesia as well as the necessary control of the coagulation system.

Adult↗
PubMed1985

Use of a modified test system to determine early pregnancy factor (EPF) levels in patients with normal first trimester pregnancy and after therapeutic abortion.

Human pregnancy can be recognized as early as 48 hours after conception using the rosette inhibition test (RIT) to detect early pregnancy factor (EPF). A modification of the test as originally described by Morton et al. is demonstrated using a monoclonal pan T-cell antibody. Studies were performed to investigate the relationship between EPF levels during normal first trimester intact pregnancies and therapeutic abortions. The change in EPF levels is compared with those of hormones after interrupted pregnancy.

Abortion, Therapeutic↗
PubMedDate not supplied

Concentrations and profiles of PCDDs and PCDFs in human mammary carcinoma tissue.

PCDD/PCDF concentrations in eight mammary carcinoma tissue samples obtained after surgical excision were similar to those found in two healthy breast glandular tissue samples from autopsy material. These levels agree well with mean concentrations in human adipose tissue from German adults. An analogous consistency was found for the congener profiles of the normalized concentrations, also in comparison with mothers' milk from Germany. In spite of similar congener profiles the concentrations in four axillary adipose tissue samples corresponding to the carcinoma samples were about 40% lower. This discrepancy was not found in one tissue pair from a healthy breast.

Adipose Tissue↗