Biomedical subjects

H R Tinneberg

Publications and source records attributed to H R Tinneberg.

At least 19 recordsLinked to original sources

PubMed2006

Attitudes of patients, healthcare professionals and ethicists towards embryonic stem cell research and donation of gametes and embryos in Germany.

Due to the Embryo Protection Act, creation of supernumerary embryos, as well as egg and embryo donation, is prohibited in Germany. Human stem cell research is regulated through the Act on stem cells that came into force in 2002. A cross-sectional survey of 101 IVF couples (n=202) in two fertility centres, and representative samples of healthcare professionals and ethicists (n=879), was carried out, and their attitudes towards embryonic stem cell research and donation of gametes and embryos compared. A clear majority of IVF couples favoured legalization of egg and embryo donation and embryonic stem cell research for various purposes. The willingness of couples to donate was related to purpose and to other independent influences. The majority of physicians voted for legalization of embryonic stem cell production from surplus embryos. Most human geneticists and obstetricians approved egg, but not embryo, donation to other couples. Ethicists and midwives were opposed to every kind of donation and research on surplus embryos. The IVF couples surveyed have positive attitudes towards donation and research using surplus embryos, whereas the healthcare professionals and ethicists are predominantly sceptical about most research activities destroying human embryos. This difference should be considered carefully in legal and ethical discussions on reprogenetics.

Attitude of Health Personnel↗

PubMed2006

Ovine placental eluate immunoglobulins recognise isologous and third party acid-treated trophoblast microvesicle antigens in vitro.

Placental microvesicles were prepared from ovine placentae and immunoglobulins eluted with 0.5 M glycine buffer pH 2.5. The ability of eluate immunoglobulins to re-associate with isologous (self) and third party acidified microvesicles was tested by ELISA. Ovine placental immunoglobulins re-associated with isologous and third party acidified microvesicles suggesting that at least 2 types of antigenic epitopes I and II maybe expressed on the ovine placentae. Type I antigens may be present on placentae of all ovines while type II epitopes may be paternally derived, hence unique to each pregnancy. Analysis by SDS PAGE revealed the heavy and light chains of IgG at 57 and 27 kDa, respectively, together giving a relative molecular weight of 158 kDa. Results suggest that immunoglobulins produced to placental microvesicle antigens may be directed to some but not all antigenic epitopes expressed on the trophoblast, possibly defining a mechanism by which the foetus evades maternal immunological rejection.

Acids↗

PubMed2005

[ENZIAN-score, a classification of deep infiltrating endometriosis].

The ENZIAN-Score is presented as a new instrument to classify the deep infiltrating endometriosis. Especially the retroperitoneal part of the severe endometriosis is focussed on. In analogy to an oncological staging four different stages are pronounced. The localisation and the expansion of the endometriosis nodule was indicated to different subgroups. The still used rAFS-score is of no clinical evidence, as we pointed out in a retrospective study of our patients with severe intestinal endometriosis.

Endometrial Neoplasms↗

PubMed2005

Human placental immunoglobulins show unique re-association patterns with isologous and third party acid treated trophoblast microvesicles in vitro.

OBJECTIVE: To study re-association pattern of human placental eluate immunoglobulins with acid treated isologous and third party trophoblast derived placental microvesicles. DESIGN: Laboratory based experimentation. SETTING: Biological Sciences Department and Discipline for Reproductive Medicine University of Newcastle, Australia and the Department of Biochemistry, University of Nairobi, Kenya. RESULTS: Placental eluate immunoglobulins re-associated with isologous and third party acidified microvesicles in three distinct patterns. I: eluate immunoglobulins re-associated more strongly with isologous and third party acid treated placental microvesicles, II: eluate immunoglobulins re-associated strongly with isologous but weakly with third party acid treated placental microvesicles, III: eluate immunoglobulins did not show preferential re-association with isologous and third party acid treated placental microvesicles. CONCLUSION: Two types of antigenic epitopes I and II may be expressed on the human placentae. Type I antigens may be present on all human placentae while type II epitopes may be paternally derived hence unique to each pregnancy. Also, immunoglobulins produced to placental microvesicle antigens may be directed to some but not all antigenic epitopes expressed on the human placental trophoblast.

Acids↗

PubMed2005

Immunoglobulin G bound to ovine placenta is eluted by surgical cannulation and acid perfusion in situ.

OBJECTIVE: To elute placental bound immunoglobulin G (IgG) in situ. DESIGN: Laboratory based experimentation. SETTING: Biological Sciences Department, The University of Newcastle Australia and the Department of Biochemistry, University of Nairobi, Kenya. SUBJECTS: Twelve pregnant ewes 10 to 15 days before the onset of natural parturition. RESULTS: Placental eluates were rich in IgG, and IgG2. The relative molecular weight of placental IgG was estimated at 158kDa by gel filtration chromatography. Analysis of eluate by SDS PAGE revealed the heavy and light chains of IgG at 57 and 27kDa respectively together giving a relative molecular weight of 168kDa. CONCLUSION: Placental bound IgG may be crucial in immunology of pregnancy and together with the cognate antigen thereof may be useful as models for the study of maternal-fetal interaction in human pregnancy and in the development of experimental immunotherapy to immunologically compromised pregnancies in humans and livestock.

Acids↗

PubMed2002

The effect of catecholamines, acetylcholine and histamine on progesterone release by human granulosa cells in a granulosa cell superfusion system.

There are experimental data demonstrating the presence and actions of various neurotransmitters in the ovary, thus supporting the view that they might play a role in intraovarian regulatory mechanisms, although their exact function in the regulation of ovarian hormone secretion is unclear. The objective of the present study was to investigate the direct action of catecholamines, acetylcholine and histamine on progesterone secretion of human granulosa cells in a superfused cell system. Human granulosa cells were isolated from preovulatory follicular fluid using a Percoll gradient centrifugation method. Approximately 2 x 10(6) cells were mixed with Sephadex G-10 and were transferred into two chambers of the superfusion apparatus. The system was perfused with a culture medium and test materials were added to the system at a dose of 100 pmol/ml. The progesterone concentration of samples was measured using an (125)I radioimmunoassay. Administration of epinephrine (adrenaline), norepinephrine (noradrenaline), dopamine and histamine had no effect on progesterone release. However, acetylcholine produced a significant progesterone release, which could be blocked by atropine. The observed effect of acetylcholine on progesterone release of superfused human granulosa cells may reflect a physiological role of acetylcholine in the regulation of granulosa cell function during the menstrual cycle.

Acetylcholine↗

PubMed2001

Modulatory effect of acetylcholine on gonadotropin-stimulated human granulosa cell steroid secretion.

The aim of this study was to explore the direct action of acetylcholine on gonadotropin-stimulated progesterone (P) and estradiol (E(2)) secretion of human granulosa cells (GCs) cultured in serum-free medium. Human GCs were isolated from preovulatory follicular fluid aspirated from 22 women undergoing in vitro fertilization at the University Women's Hospital of Tübingen. The production of progesterone and E(2) was measured in the presence and absence of acetylcholine, carbachol, atropine, luteinizing hormone (LH) or follicle-stimulating hormone (FSH) using radioimmunoassay. Statistical analysis of the data was performed by ANOVA and Newman-Keuls test. Administration of acetylcholine or carbachol (10(-5) M) resulted in a significant increase in P and E(2) secretion. This response was specifically blocked by the muscarinic receptor antagonist atropine. Similarly, carbachol resulted in a significant increase in P and E(2) output, though the response to it was somewhat reduced when compared to that evoked by acetylcholine. Acetylcholine did not show any additive effect on LH-stimulated P secretion, while it augmented the stimulatory effect of FSH on P release. In contrast, carbachol markedly diminished the stimulatory effect of LH on P secretion, while it caused no change in FSH-induced P output. When administered together, acetylcholine did not modify the stimulatory effect of FSH on E(2) secretion, however, it markedly elevated LH-induced E(2) output. Similar to this, carbachol significantly increased LH-induced E(2) release, however it decreased FSH-stimulated E(2) secretion. We suggest that acetylcholine has a direct modulatory effect on gonadotropin-stimulated steroid production of GCs, an effect that is mediated via muscarinic receptors. This effect may have a physiological role in the regulation of GC function during the menstrual cycle.

Acetylcholine↗

PubMed2001

Influence of melatonin on basal and gonadotropin-stimulated progesterone and estradiol secretion of cultured human granulosa cells and in the superfused granulosa cell system.

The aim of this study was to explore the direct action of melatonin (Me) on basal and gonadotropin-stimulated progesterone (PG) and estradiol (E2) secretion of human granulosa cells (GCs) cultured in serum-free medium and in a superfused GC system. Human GCs were isolated from preovulatory follicular fluid aspirated from 34 women undergoing in vitro fertilization at the University Women's Hospital of Tübingen. PG and E2 production was measured in the presence and absence of Me, propranolol, LH or FSH using radioimmunoassay. Statistical analysis of the data was performed by ANOVA and Newman-Keuls test. Me stimulated E2 secretion in a dose-dependent manner. Propranolol did not cause any change in E2 secretion, and when given with Me, it only partially blocked but could not entirely prevent E2 output. There was no statistically significant effect of Me on PG production when Me was administered at concentrations between 10(-4) and 10(-8) M. However, at 10(-3) M Me significantly suppressed PG output of granulosa cells. LH and FSH significantly stimulated the secretion of both steroid hormones. Me significantly reduced LH- and FSH-induced E2 secretion, as well as LH-stimulated PG output, while it caused only a slight, yet significant decrease in PG secretion. In the superfused GC system, FSH and LH resulted in a significant stimulatory effect on PG release. Me did not modify the stimulatory effect of FSH on PG, while it caused some delay in LH-stimulated PG release. Propranolol and Me had no stimulatory effect on PG release. On the basis of our results we suggest that Me has a direct modulatory effect on basal E2 and gonadotropin-stimulated E2 and PG secretion of human GCs. The observed effect may play a physiological role in the regulation of GC function during the menstrual cycle.

Adrenergic beta-Agonists↗

PubMed2001

The pregnancy rates--a retrospective comparison of tubal and uterine embryo transfers.

Tubal embryo transfer (TET), which involves an embryo transfer via the uterine tube, has a possible advantage over uterine embryo transfer (UET) due to more natural timing of embryo exposure to the uterine cavity. This study was carried out to evaluate the pregnancy rate of TET versus UET. Eight hundred and ninety-seven consecutive patients who underwent embryo transfers from July 1997 to June 1999 in Bielefelder Institut fuer Fortpflanzungsmedizin (BIF.), Germany were included in this study. Two hundred and eighty-six pregnancies were achieved in 167 cases (31.4%) after TET and 119 cases (24.6%) after UET. The abortion rate of the TET group was 12.0 per cent while that of the UET group was 23.3 per cent. Our results showed that TET has a significantly increased clinical pregnancy rate and significantly decreased abortion rate. There is an advantage in transferring embryos to the fallopian tube in infertile couples with male factor infertility and unexplained infertility. We recommend TET as the first choice for embryo transfer in infertile couples with patent fallopian tubes and with no evidence of pelvic adhesion and/or endometriosis.

Abortion, Spontaneous↗

PubMed2000

Recurrent pregnancy losses and the role of immunotherapy.

Post implantation pregnancy losses are psychologically and economically stressful to the childbearing population. The etiology in the vast majority of cases is unknown but is partly thought to result from a break-down of the maternal tolerance to the fetoplacental unit. Immunologically based therapy remains controversial but no alternative therapy is available at the moment. This article reviews the conceived immunological basis of recurrent pregnancy losses, discussing the controversies arising, and recommending the use of intravenous immunoglobulin, IVIg, in well controlled experiments for further clinical trials.

Abortion, Habitual↗

PubMed2000

A dynamic in vitro investigation of the characteristics of the granulosa cells hormone secretion.

OBJECTIVE: Basic characteristics of ovarian steroid production has largely been clarified by the use of human granulosa cell cultures in vitro. This technique made also possible to test different stimulatory and blocking hormones and chemicals in the cell cultures to clarify regulatory mechanisms of the granulosa cells. However, these cell cultures are static systems that do not give information about the dynamics of steroid production of the granulosa cells. Therefore, in the present study we have tried to establish a dynamic model using the so called superfusion method. METHODS: Granulosa cells were isolated from follicular fluid obtained by aspiration from patients undergoing in vitro fertilization program. The granulosa cells were packed into a closed Sephadex G10 column which was continuously kept at 37 degrees C and washed with McCoy's 5A culture medium. Samples of the medium leaving the column were collected in every 30 minutes with a fraction collector. Stimulation with LH and blocking with cycloheximide were carried out by adding the materials into the perfusing culture medium. Progesterone levels of the samples were measured by RIA-s. RESULTS: We found that the basal progesterone secretion is pulsatile even in the absence of any stimulation. After stimulation with LH there is a rapid, but a slight increase in the steroid levels, followed by a delayed and also pulsatile definite increase of progesterone levels starting at about 30 minutes. CONCLUSIONS: From the data obtained it is clear that human granulosa cells are storing progesterone in a small quantity that is LH releasable. The delayed progesterone increase is due to de novo synthesis of the hormones after the gonadotropin stimulation, which takes about 60 minutes.

Cell Culture Techniques↗

PubMed1999

The outcome of intracytoplasmic sperm injection in patients with retrograde ejaculation.

The objective of this retrospective clinical study was to assess the benefit of assisted fertilization in cases of anejaculatory infertility due to retrograde ejaculation. We report the outcome of intracytoplasmic sperm injection (ICSI) treatment. In 16 couples in which the men suffered from retrograde ejaculation. We performed 35 cycles of ICSI with spermatozoa retrieved from post-ejaculatory urine. The patients had been instructed to alkalinize the urine by ingesting sodium bicarbonate before the procedure. The fertilization rate averaged 51.2%. Seven clinical pregnancies were achieved. Three spontaneous first trimester abortions occurred, but three live offspring were delivered and one pregnancy is ongoing. In conclusion, the use of ICSI may be feasible for patients with retrograde ejaculation who are resistant to medical treatment and whose sperm quality is so low or unpredictable that intrauterine insemination or conventional methods of in-vitro fertilization are not possible.

Adult↗

PubMed1998