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Biomedical subjects

W Würfel

Publications and source records attributed to W Würfel.

At least 19 recordsLinked to original sources
PubMed1992

Prenatal diagnosis by amniocentesis in 82 pregnancies after in vitro fertilization.

We report on the outcome of 82 amniocenteses (AC) carried out during pregnancies after in vitro fertilization (IVF) from 1-1-1985 to 31-12-1989. The main indication for amniocentesis was a maternal age of greater than or equal to 35 years. In 48 cases, we found an anterior placenta and assumed that this was related to the position in which the uterine embryo transfer was performed. In six pregnancies, we found an abnormal karyotype, including two cases of trisomy 21; the two couples decided for abortion. Four aberrations in the fetal karyotypes were also present in either the mother or the father, the resulting children are healthy. The further course of pregnancies after IVF and AC was characterized by a higher incidence of toxemia, uterine bleeding before the 28th week of gestation, abruptio placentae, and premature deliveries, when compared to the course of pregnancies after spontaneous conception. We believe that these occurrences were not caused by AC, as the incidence was higher in all our pregnancies after IVF (without AC) and has also been reported in pregnancies after ovarian hyperstimulation without IVF. Therefore, we see no reason to renounce AC after IVF. However, the special risks inherent in pregnancies after IVF must always be discussed with the couple.

Adult↗
PubMed1992

Maternal immunization by husband's leukocytes for repeated fetal death associated with mild pre-eclampsia--case report with successful outcome.

We report a case of repeated fetal death at 31 gestational weeks associated with mild non-proteinuric pre-eclampsia and intrauterine growth retardation. After double intradermal immunisation with paternal leukocytes, a third pregnancy proceeded uneventfully until it ended at 38 weeks. Maternal anti-paternal blocking antibody activity was assessed by the erythrocyte antibody inhibition (EAI) test. Serologic testing revealed that the couple did not share HLA class I antigens. The mechanisms underlying the likely benefit from immunotherapy are discussed.

Antibody Formation↗
PubMed1992

[Regulation of sterol carrier protein-2 in human luteal cells by LH and LH-RH].

Conversion of cholesterol to pregnenolone is the most important and, at the same time, the rate-limiting step of steroidogenesis. Sterol carrier protein-2 (SCP2) or nonspecific lipid transfer protein (nsL-TP) is an intracellular protein, which plays an important role in the pre- and transmitochondrial transport of cholesterol and for the mitochondrial synthesis of pregnenolone. Synthesis of pregnenolone in rat Leydig cells can be increased by LH and LH-RH; however, only LH leads to characteristic changes in intracellular concentrations of SCP2. This means that synthesis of pregnenolone is regulated in two different ways. In this study we aimed to find out whether such a 'second way' of steroidogenesis is also demonstrable for the human corpus luteum (i.e. human luteal cells). Human luteal cells were collected during follicle punctures and were cultured as described previously. We demonstrate that (human) LH/hCG are able to enhance pregnenolone synthesis; this process is accompagnied by typical changes of SCP2 and an increase in activity of 7-dehydrocholesterol reductase, which is a marker enzyme for SCP2. LH-RH was shown to exert no effect. Thus, we conclude that a second way of steroidogenesis (i.e. synthesis of pregnenolone) cannot be proved for the human corpus luteum.

Carrier Proteins↗
PubMed1992

[Thyroid regulation pathways and its effect on human luteal function].

There are interferences between function of the thyroid gland and the ovary. Thus, thyroid disorders may influence the ovarian cycle. Up to now interferences in three main areas are described: the secretion of GnRH, i.e. FSH and, above all, LH, the peripheral metabolism of steroids (androgens, estrogens, and SHBG), and metabolism of prolactin. By employing human luteal cells, we were able to demonstrate that there is also a direct impact of thyroid regulation on luteal function: TSH, but not TRH or T3 or T4, possesses a luteotropic activity and reaches one fifth of the biological activity of hCG. This kind or direct influence may play an important role in the pathophysiology in patients with hypothyroidism.

Feedback↗
PubMed1992

Suppression of human chorionic gonadotropin in the human placenta at term by human thyroid-stimulating hormone in vitro.

Human chorionic gonadotropin (hCG) exerts a clinically apparent negative feedback on the secretion of human thyroid-stimulating hormone (hTSH) in pregnancy, and the two have cross-reactivity for the TSH receptor in membrane preparations of the thyroid. We examined whether hTSH, in turn, has an influence on the secretion and synthesis of hCG in short-term cultures of human placenta at term. A dose- and time-dependent decrease in the extracellular hCG concentration caused by hTSH was demonstrated. To examine whether hTSH inhibits de novo synthesis of hCG or decreases hCG depletion, we determined the amount of hCG secreted and the size of the intracellular pool by using an enzyme immunoassay. By incorporating a radiolabeled amino acid in the hCG molecule, we measured the amount of hCG synthesized de novo. We concluded that hTSH acts by decreasing the rate of de novo synthesis of placental hCG.

Chorionic Gonadotropin↗
PubMed1992

Effects of prolactin on secretion and synthesis of human chorionic gonadotropin in human term placentas in vitro: short-term increase in secretion, followed by medium-term suppression of synthesis and secretion.

We studied the influence of human prolactin on the secretion and de novo synthesis of human chorionic gonadotropin (hCG) in the human term placenta in culture. Placental tissue from 14 patients with uncomplicated pregnancies and deliveries was prepared mechanically, with addition of a Percoll gradient step. hCG levels were determined in the culture media and in the cytosolic fraction of cells by means of an enzyme immunoassay with coated beads. The amount of newly synthesized hCG was measured by the extent of incorporation of 35S-methionine into the hCG molecule. Our results showed that human prolactin had two different effects in vitro: between 1/2 and 1 h, prolactin slightly increased secretion of hCG into the culture medium without affecting de novo synthesis; after 2 h, prolactin began to cause a significant decrease in both secretion and de novo synthesis of hCG over several hours. It appears that both effects are receptor mediated, for ovine prolactin failed to produce any response. We conclude that prolactin is one of the main factors regulating the synthesis and secretion of hCG in the human trophoblast at term.

Animals↗
PubMed1991

[Continuous pulsatile subcutaneous gonadotropin stimulation in polycystic ovary syndrome: a therapeutic alternative].

In order to improve the ovarian response to exogenous gonadotropins and to reduce the risk of the ovarian hyperstimulation syndrome and of multiple pregnancies, human menopausal gonadotropin (hMG) was administered by continuous pulsatile subcutaneous (s.c.) infusion via a portable pump. The effectiveness of pulsatile hMG treatment was first demonstrated in a control group comprising 7 females with regular ovulatory cycles, who underwent gonadotropin ovarian superovulation and subsequent IVF/GIFT procedures for tubal or male factor. All pulsatile s.c. hMG cycles were ovulatory and one clinical pregnancy was achieved. In this group, ovarian response was similar following intramuscular (i.m.) and pulsatile s.c. hMG therapy, with a marked reduction of preovulatory serum levels of oestradiol in the pulsatile s.c. hMG cycles. In a prospective study, 11 patients with overt polycystic ovary syndrome (PCO) who failed to ovulate in response to clomiphene, received i.m. hMG ovarian superovulation treatment in 19 cycles and pulsatile s.c. hMG in 21 cycles. Following i.m. hMG treatment, only 10 cycles were ovulatory; 7 cycles had to be cancelled for impending ovarian hyperstimulation syndrome. Following pulsatile s.c. hMG treatment, 15 cycles were ovulatory, only 3 treatment cycles had to be disrupted for multifollicular ovarian response. Both modes of treatment were similar in terms of requirement of hMG ampoules, number of preovulatory follicles, preovulatory serum levels of oestradiol and duration of the preovulatory oestradiol rise. The total duration of hMG treatment was significantly increased following pulsatile s.c. hMG. It is concluded, that in overt PCO syndrome, continuous pulsatile s.c. administration of hMG is an effective method to induce follicular maturation and to achieve ovulations.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Surgical pelviscopy in treatment of extrauterine pregnancy following in vitro fertilization and spontaneous conception].

We report on our experience with surgical pelviscopy in the treatment of ectopic pregnancies after in-vitro fertilisation and, in comparison, during spontaneous cycles and during cycles with ovarian hyperstimulations and IUI. From 1.1. 1988 to 31.12.1990, 54 patients underwent this operation, 25 of these having undergone the IVF programme. All IVF patients had an extensive history of tubal sterility. Therefore, we found difficult anatomic conditions during the operation in most cases. Furthermore, the special conditions of the IVF treatment itself (e.g., multiple transfer of embryos into the uterus) caused a higher incidence of complicated situations (one triple ectopic, three ovarian ectopic pregnancies and one simultaneous pregnancy). Firstly, our experience leads to the conclusion, that surgical pelviscopy can be used for management of more complicate problems and can be regarded, so far, as an alternative to laparotomy. Secondly, laparotomy should not be replaced by pelviscopy in difficult situations (e.g., ovarian ectopics pregnancies). Surgical pelviscopy reduces the trauma of treatment, a consideration, which is very important especially for IVF patients. Because of the extraordinary problems related to ectopic pregnancies after IVF, we are at present sceptical about the use of other methods (e.g., instillation of prostaglandins or methotrexate) for these patients. Subsequently, 19 patients in the IVF group conceived with an intrauterine pregnancy after repeated IVF treatment. In the second group, 8 spontaneous intrauterine conceptions have occurred since.

Abortion, Spontaneous↗
PubMed1991

Serial scintigraphic imaging for visualization of passive transport processes in the human fallopian tube.

Spontaneous migration of a radionuclide tracer from the vagina to the peritoneum may be visualized by scintigraphic imaging (hysterosalpingoscintigraphy, HSS). A prospective study was designed to evaluate diagnostic criteria for normal tubal passage of a control group (n = 7) and to establish the predictive value of the HSS technique in defining functional deficiency in anatomically patent tubes. In 56 patients with tubal and unexplained infertility, a comparison between the results of the tracer migration study and of contrast hysterosalpingography and laparoscopy was made. The overall correlation was 65%. Clearly discrepant results (i.e. an abnormal migration pattern in anatomically patent tubes) were recorded in 18% and were positively, yet not significantly associated with tubal adhesive disease and with a history of tubal microsurgery. Interpretation of scans was equivocal in another 18% of patients due to undetectable ascension of the tracer to the uterus. It is suggested that the radionuclide is moved forward by the same passive transport processes which are concerned with support of the migration of spermatozoa to the ovum, and that failure of tubal migration of the tracer may render patients eligible for in-vitro fertilization/embryo transfer treatment.

Adult↗
PubMed1990

Prednisolone promotes the secretion of progesterone and oestradiol by luteinised granulosa cells independent of human chorionic gonadotropin.

An in vitro model based on luteinised granulosa cells gained during an in vitro fertilisation programme examines the question of whether prednisolone, and thus glucocorticoids in general, are capable of exerting an influence on the secretion of oestradiol and progesterone. It can be demonstrated that prednisolone leads to dosage-dependent increases in the concentration of both steroids, even independently of concurrent stimulation by human chorionic gonadotropin. A similar mechanism for aromatase activity of human adipose cells is suggested.

Chorionic Gonadotropin↗
PubMed1989

[Initial experiences with hysterosalpingoscintigraphy in normal and pathologic fallopian tube passage].

A prospective study in 38 patients was designed to evaluate the efficacy and reliability of radionuclide hysterosalpingoscintigraphy (HSS) using 99mTc labelled human albumin macroaggregates (HAMA). Following application in the posterior vaginal fornix at the time of ovulation, HAMA normally migrate spontaneously through the uterus and tubes and may be identified after 20 min (range 5-90 min) in the uterine cavity and after 2 hrs (range 40 min - 3 hrs) in the free pelvis, using a gamma camera. When correlated with the findings of conventional contrast hysterosalpingography (HSG), the radionuclide procedure yielded comparable results in females with patent or clearly obstructed tubes. Using 8-10 MBq 99mTc, radiation exposure was estimated to be 0.75 cGy per ovary, which is considerably less than the mean dose absorbed with HSG. As the HSS procedure imitates the migration of spermatozoa by the means of an inert tracer, it allows a direct insight in the mechanisms of passive transport taking place in the uterus and tubes at the period of ovulation. Thus, it reflects the physiological state of the female reproductive tract. On the basis of the scintigraphic findings, equivocal results on HSG have to be re-evaluated, as tubes, which are anatomically patent under high pressure, may be functionally deficient.

Adult↗
PubMed1989

[Intra-tubal embryo transfer (IVF/IT-ET) in the treatment of non-tubal-induced sterility. Initial studies of the value of a new and expensive therapy procedure].

Intratubar embryo transfer is a form of sterility treatment, in which the in-vitro-fertilized pre-implantation embryos are transferred into the intact fallopian tube(s). This enables the benefits of in-vitro fertilization (information of the gamete fertilization behavior, specific incubation of dysmature oocytes, reduction of the polyploidy rate, risk of multiple pregnancies) to be combined with those of gamete intrafallopian transfer (GIFT; tubar environment for the further development of the pre-implantation embryos). Intratubar embryo transfer is indicated in cases of sterility that are not due to the fallopian tubes; in addition to idiopathic sterility, particular emphasis is put on a certain form of immunological sterility (antibodies against sperm antigens), which seems to be a special indication for this method. Intratubar embryo transfer demands a two sided approach. It is advisable to collect the oocytes transvaginally, guided by ultrasound, since general anaesthesia maybe dispensed with - if so desired. The embryo transfer itself still requires a pelviscopy, which is only performed once fertilization of the oocyte has been confirmed; which is in contrast to GIFT, in which pelviscopy is an inherent part of each treatment cycle. In spite of this advantage, intratubar embryo transfer is a method, which is associated with a high expenditure. The aim of the study was, to evaluate the success rate when all the alternative, less costly options have been exhausted. Our first results are demonstrating, that intratubar embryo transfer is successful, even as a second line therapy. Therefore the method has a significance in the treatment of sterility, not caused by the tubes and the expenditure, with which it is associated, can be justified.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗