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Biomedical subjects

G Bettendorf

Publications and source records attributed to G Bettendorf.

At least 37 records · Page 2Linked to original sources
PubMed1986

Radioreceptor assay for lactogenic hormones based on membranes from rat mammary tumour.

A highly sensitive radioreceptor assay (RRA) for human prolactin (hPRL) based on membrane preparations obtained from chemically induced rat mammary tumour is described. The binding of 125I-labelled, highly purified pituitary human prolactin was specific for lactogenic hormones and depending on time, temperature, and concentration of receptor protein. Optimal specific receptor binding (18-20%) was obtained by incubation at 21 degrees C for 18 h. The prolactin receptor was shown to have a single "class" of binding sites with an affinity constant (Ka) of 6.0 X 10(10) mol-1. The binding capacity was 8-33 fmol/mg membrane protein. The sensitivity of the radioreceptor assay was 0.5 ng/ml ovine prolactin (NIH-PS-10) or 0.84 ng/ml human prolactin (NIH-VLS-4). The receptor binding activity of various purified prolactin preparations from different species was comparable to the biological hormone activities, indicating that this in vitro assay system measures values which are biologically relevant.

Animals↗
PubMed1985

[Gonadotropin stimulation during LH/RH analog-induced inhibition of pituitary function].

Ovarian stimulation with hMG/hCG is most effective in hypogonadotropic patients. In normogonadotropic/estrogen-positive patients in whom gonadotropin therapy is also indicated after failure of other forms of treatment, it is much more difficult and considerably less effective. The objective of this study was to change the endocrine status in patients from a normogonadotropic and estrogen-positive status, by administration of a GNRH analogue, to a hypogonadotropic, estrogen-negative status, in order to create better conditions for gonadotropin stimulation. For this purpose Buserilin was administered either intranasally or intravenously and the endocrine reaction was observed. The endocrine changes observed were very varied. In the majority of cycles a fall in plasma FSH concentrations resulted (20 out of 28), in 2 a rise, while in 6 of the 28 there was no change. In 12 out of 28 cycles the plasma LH concentration decreased; it rose in 3 and was unchanged in 13. The LH fluctuation was suppressed or irregular in all cases. Estrogen secretion was unaffected in 16 cycles; it increased continuously in 6 cycles and temporarily in a further 6. The reaction to the hMG injections did not show the hoped-for improvement with simultaneous administration of an RH analogue. A complete and constant suppression of pituitary function, and thus the creation of a hypogonadotropic state, could not be achieved by medication with 8 X 300 micrograms Buserilin or intravenous injection of 5 and 10 micrograms every 90 minutes.

Adult↗
PubMed1985

[Gonadotropin treatment in ovarian insufficiency, stimulation of follicle maturation with human urinary FSH].

Thirty-two infertile patients with basal FSH/LH ratios of less than 0.5 were treated with a pure human urinary FSH preparation in various doses, in 57 cycles. With initially low FSH doses and increase in the dose according to the individual reaction (analogous to hMG therapy) ovulation and a normal luteal phase were achieved in 22 out of 25 cycles, and 6 pregnancies. In one cycle there was a clinical overstimulation syndrome in early pregnancy. Treatment with high doses of FSH at the beginning of the cycle proved unsuitable: normal follicle stimulation, ovulation and luteal phase only occurred in 12 out of 23 cycles, and there was no pregnancy. The combination of FSH therapy with initially high doses and subsequent stimulation with hMG resulted in ovulation in 9 out of 10 cycles without ensuing pregnancy. The behaviour of the endogenous LH under FSH therapy varied: with an initially high dose of FSH there was a clear drop in serum LH concentrations in 8 out of 23 cycles, and with an initially low dose in 5 out of 25 cycles. In 5 cycles the serum LH concentrations rose under FSH therapy. The results of the investigation confirm earlier observations that ovarian stimulation with FSH is possible in cases with low endogenous FSH/LH ratios, and that it is best accomplished by individualized therapy with an initially low dose. However, because of the different reaction of endogenous LH secretion, a better ovarian reaction than with hMG therapy could not be achieved with regard to ovulation and pregnancy rate, course of the luteal phase and overstimulation.

Adult↗
PubMed1985

[A clinical study of the treatment of sterility in hyperandrogenic ovarian insufficiency].

The therapeutic effect of glucocorticoid therapy in infertile patients with hyperandrogenemic ovarian insufficiency was verified in a clinical study and compared with the results of other forms of therapy. Of 40 patients treated with 0.5 mg/d dexamethasone only one conceived. Of 47 patients treated with 7.5 mg/d prednisone 6 became pregnant. A combination therapy of dexamethasone and clomiphene resulted in 3 pregnancies among 20 patients; a combination of prednisone and clomiphene in 18 patients led to one pregnancy. In the majority of these patients previous treatment with clomiphene only had been unsuccessful. In the patient in whom both clomiphene and glucocorticoid therapy was unsuccessful, hMG/hCG therapy was applied. The pregnancy rate, 24% in the dexamethasone group and 36% in the prednisone group, was much higher. Plasma testosterone concentrations were not significantly suppressed under corticoid therapy. Neither at the beginning of a cycle nor at the time of ovulation were FSH and LH levels changed by the administration of corticoids. There was no significant correlation between the plasma testosterone values and the length of the cycle, the duration of the follicular phase, the duration of the rise in basal temperature or the length thereof. There was a significant correlation between testosterone and the LH/FSH quotient at the beginning of the cycle both in the spontaneous cycles and under corticoid therapy, though not under clomiphene therapy. In the control cycles there was a significant correlation between testosterone and LH; in the corticoid cycles it was not significant, and under corticoid therapy there was no correlation. A negatively significant correlation between testosterone and FSH was found in the control cycles. This correlation was not significant under glucocorticoid therapy and there was no correlation under clomiphene therapy. As testosterone concentrations increased a decrease in the percentage of biphasic cycles was observed in all groups. Regardless of the testosterone concentration, the pregnancy rate in patients showing signs of androgenization, at 22%, was higher than in patients without these symptoms. In patients who conceived under corticoid therapy there was no uniform correlation either to the pretherapeutic testosterone levels or to the degree of testosterone suppression. Neither the initial testosterone level nor the degree of its suppression is of any prognostic value for corticoid therapy. The more pronounced the clinical symptoms in hyperandrogenemic patients, the more effective a corticoid therapy will be; this applies both to signs of androgenization as well as to the degree of ovarian insufficiency.

Adult↗
PubMed1985

[Rate of pregnancy in the treatment of sterility during spontaneous and therapy cycles].

Serum hCG was determined in 231 infertility patients in the late luteal phase of spontaneous and therapeutic cycles. The aim was to establish whether the discrepancy between the high number of induced ovulation cycles and the far lower cycle-related pregnancy rate can be explained by subclinical abortion. In 16.7% of spontaneous cycles hCG was positive; in 16.8% of these cases clinical pregnancy subsequently occurred. The rate of biochemically detectable pregnancies was no higher under endocrine therapy. However, under treatment with clomiphene, epimestrol, prolactin inhibitors and glucocorticoids the rate of clinical pregnancies was almost twice as high, and after hMG/hCG therapy clinically demonstrable pregnancies developed from biochemically identified ones in 76% of the cycles. The investigations show that a stimulation therapy leading to ovulatory cycles after multifollicular development increases the clinical pregnancy rate without resulting in a higher rate of very early abortions.

Bromocriptine↗
PubMed1984

Polymorphism of human pituitary lutropin (LH). Effect of the seven isohormones on mouse Leydig cell functions.

The effect of the 7 different molecular forms of human pituitary lutropin (LH) on mouse Leydig cells as a model of a target organ were studied. The hormone functions have been characterized by receptor binding, cAMP accumulation and testosterone production. One important finding was the similar intrinsic in vitro biological activity for all isohormones. Quantitatively, however, the potencies of the 7 hormone forms did not correlate with the activities obtained by radioimmunoassay: there was a dramatic decrease of receptor binding activity and biological activity compared to immunoactivity from the more alkaline to the more acidic LH isohormones.

Animals↗
PubMed1982

Biological and immunological potencies of lutropin (LH) in human serum: comparative studies using different standard preparations.

The mouse leydig cell in vitro-bioassay for LH, first reported by van Damme, Robertson and Diczfalusy (1974) was modified and applied to female and male serum. Non-parallelism of dose-response curves between serial dilutions of individual male as well as female sera and LH standards was caused by damage to incubated interstitial cells in the presence of human serum. The extent of cell damage- paralleled by an inhibition of testosterone production - was a characteristic of individual human sera rather than a general protein effect. This inhibition could be completely avoided by mild heating of the serum for 15 min at 50 degree C prior to the assay. Using this pretreatment, reliable LH values were obtained for normal males, cycling females and postmenopausal women. Biological LH measurements were compared with RIA-LH potencies. The following LH value were obtained by both methods (mean +/- sd) in terms of mlU 2nd IRP HMG/ml serum: males (n = 35), BIO: 23.3 +/- 9.0, IMMUNO: 11.0 +/- 4.3; cycling females (n = 30), BIO: 30.9 +/- 14.6, IMMUNO: 17.4 +/- 5.9; postmenopausal women (n = 12), BIO: 324 +/- 138, IMMUNO: 117 +/- 43. It could be shown that the use of different reference preparations caused great differences in the ratios of biological to immunological potencies e.g. for male serum 0.9, female serum 0.7-5.6 and postmenopausal female serum 1.1 - 8.8. Irrespective of the standard used, significant differences between the B:l ratios of male, female and postmenopausal female sera were found.

Animals↗
PubMed1982

Gonadotropin therapy of female infertility. Analysis of results in 416 cases.

This report is based on 416 infertile female patients who were treated for 1,033 cycles with gonadotropins. 28.6% of the patients conceived after hMG/hCG treatment in 79.8% of these pregnancies, healthy children were born. Spontaneous abortion or premature birth occurred in 20.2% of the cases. The twin rate was 28.6%, the triplet rate 5.5%. Most of the abortions occurred in the first trimester (52.2%). No malformations were seen. The pregnancy rate showed striking differences in the various diagnostic groups: hypogonadotropic amenorrhea 44.4%, normogonadotropic amenorrhea 50%, anovulatory cycles 22%, corpus luteum insufficiency 14.8%. The abortion rates for these four groups were as follows: hypogonadotropic amenorrhea 25%, normogonadotropic amenorrhea 14.7%, anovulatory cycles 4.8%, corpus luteum insufficiency 36.3%. A detailed analysis of the treatment cycles is given for the four groups: the number of ampoules of hMG/hCG increased from 21.4 ampoules in patients with corpus luteum insufficiency to 47.7 ampoules in patients with hypogonadotropic amenorrhea. The inactive phase increased from 5.6 days in patients with corpus luteum insufficiency to 8.5 days in patients with hypogonadotropic amenorrhea. Estrogen values around the time of ovulation and in the corpus luteum phase were much lower in patients with spontaneous uterine bleedings. Hyperstimulation syndrome occurred less frequently in these patients. The percentage of pregnancies decreased in patients with corpus luteum insufficiency from 8.1% in the first treatment cycle to 4.8% in the following treatment cycles, whereas it increased from the first to the following cycles in the other diagnostic groups. Patients with anovulatory cycles and corpus luteum insufficiency respond differently to hMG/hCG treatment than patients with normogonadotropic amenorrhea. The inactive and active phase are important parameters for the evaluation of ovulation induction with hMG/hCG, hMG/hCG treatment is of little value in patients with corpus luteum insufficiency.

Amenorrhea↗
PubMed1978

[Clinical experimental studies in the treatment of ovarian dysfunction with bromo-ergocryptin (pravidel) (author's transl)].

Among 62 patients with galactorrhoea a corpus luteum deficiency or anovulatory cycles were found in 35 cases by serum progesterone determination, endometrial biopsy or basal body temperature records. 27 patients had a hyperpro-lactenemic amenorrhoea-galactorrhoea syndrome. During treatment with 2.5-5 mg. of Pravidel daily the basal body temperature was recorded, the concentrations of serum FSH, LH, Prolactin and progesterone were determined by radioimmunoassay. Other possible reasons for infertility were investigated. 10 of the 19 patients with normal serum prolactins in the group with deficient corpus luteum or anovulation became pregnant after a short duration of treatment, whereas only 2 of the 16 patients with hyperprolactenemia became pregnant. Among 27 patients with secondary amenorrhoea 11 became pregnant. All these patients had increased serum prolactins. During treatment with Pravidel all patients showed a significant increase of FSH and LH concentrations and a decrease of the prolactin concentrations. The outcome of the pregnancy of the 58 patients who became pregnant during treatment with Pravidel was also reported. 14 of the 58 pregnancies occured following additional treatment with Dyneric or HMG/HCG. Up to now there were 18 term deliveries following uneventful pregnancies. There were no fetal anomalies. The abortion rate was not higher than in the general population. All results show that euprolactinemia is not alone characterized by normal prolactin concentration. The clinical signs and symptoms of galactorrhoea without increase of prolactin over 20 ng/ml. in conjunction with ovarian dysfunction must be classified as dysprolactinemia.

Amenorrhea↗
PubMed1978

[Results of routine treatment with Clomiphen (author's transl)].

After 15 years of clinical experiences with Clomiphen treatment it seemed desirable to investigate the efficiency of this kind of therapy under routine conditions in a crowded out-patient clinic. 314 patients treated from 1972--1974 have been included in this study. From 242 sterility patients 730 cycles could be followed. 80.2% were ovulatory, but 23.5% had an insufficient luteal phase and 11.9% of these cycles ended with an anovulatory bleeding. The overall pregnancy rate was 30%. Side-effects were recorded in 4.5% but all of them were harmless, no overstimulation occurred. After discontinuation of Clomiphen therapy 8% of all patients had spontaneous cycles. In 36 patients with eugonadotropic secondary amenorrhea with a total of 115 treatment cycles ovulation was recorded in 58%. Pregnancy rate was 25%, the intensity of treatment 3.1. In 54 patients with anovulatory cycles 156 cycles (72,3%) became ovulatory, pregnancy rate was 24%, the intensity of treatment 3.5. In another group of 19 patients with oligomenorrhea ovulation occurred in 39 of 42 cycles, 4 patients became pregnant. In 108 patients with luteal phase defects in 338 cycles ovulation was found in 90.2%, with 26.6% of these cycles being still insufficient. The pregnancy rate was 18.5%, the intensity of treatment 3.7. 9.8% of these 338 cycles became anovulatory during clomiphen treatment. In 27 patients with "insufficient cycles" in 104 treatment cycles nearly all of them were ovulatory but 20% of them were found to have an insufficient corpus luteum phase. The pregnancy rate was 30%. The highest pregnancy rate was found during the first 3 treatment cycles (26%). It is consequently our policy to treat patients 4 to 6 times with clomiphen and when no pregnancy can be achieved, these patients should be treated with HMG/HCG. 65 of 73 pregnancies were followed, 52 patients were delivered with healthy babies, 12 patients aborted. Of the total number of 54 babies born, 47 were single, 6 were twins, 2 babies were stillborn. The sex ratio (male to female) was 2.2. No malformations were found. In our group of patients other factors besides ovarian dysfunction contributed to the relatively low pregnancy rate. Thus, in 116 out of 244 patients one tube was occluded, while adhesions were found in 99 treated with clomiphen as a diagnostic step to convince the patient, that stimulation of ovarian function will be possible whenever the patient desires to become pregnant. The ovulation rate in this group was 38% in addition 37% responded with anovulatory bleeding, thus, 74% of all patients experienced a positive reaction from their point of view. After discontinuation of clomiphen administration 18% of these patients continued to bleed with (7.5%) or without (10.6%) clinical signs of ovulation. A further observation is the obvious fact that clomiphen therapy free intervals can be interposed without risk of a lower success rate, compared to patients receiving continuous cycle to cycle treatment.

Adolescent↗
PubMed1976

A low molecular weight substance obtained from serum which has luteinizing hormone like activity ("mini LH").

A low molecular weight substance of 1000-2000 daltons has been isolated in dialysates of normal human serum which, on testing in a radio-immunoassay, a radioligand receptorassay and an in-vitro bioassay exhibited LH activity comparable to the range of LH activity found in normal serum. The substance was heat labile. Its reactivity in a RIA suggests peptide nature. No "mini LH" activity could be derived from LH-free serum samples of hypophysectomized patients.

Biological Assay↗