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Die rechtliche Regelung der Fortpflanzungsmedizin ist dringend reformbedurftig. Das Embryonenschutzgesetz von 1990 erfasst die neuesten technischen Entwicklungen nicht, ist in manchen Bereichen unstimmig und luckenhaft, setzt die betroffenen Frauen, Paare und Kinder unnotigen gesundheitlichen Risiken aus, erschwert paradoxerweise die Durchsetzung von Kinderrechten und erzeugt Gerechtigkeitsprobleme und Rechtsunsicherheit fur die betroffenen Paare und die behandelnden Arztinnen und Arzte. Das Embryonenschutzgesetz enthalt zudem nur strafrechtliche Verbote. Diese erlauben keine angemessene Reaktion auf die medizinische Entwicklung und den gesellschaftlichen Wandel und werden der Komplexitat der Materie nicht gerecht. Diese Probleme mussen gelost werden. Der Bundesgesetzgeber verfugt seit mehr als 20 Jahren uber die Kompetenz zur Regelung der Fortpflanzungsmedizin. Er sollte in der kommenden Legislaturperiode ein umfassendes Fortpflanzungsmedizingesetz schaffen.

Die rechtliche Regelung der Fortpflanzungsmedizin ist dringend reformbedurftig. Das Embryonenschutzgesetz von 1990 erfasst die neuesten technischen Entwicklungen nicht, ist in manchen Bereichen unstimmig und luckenhaft, setzt die betroffenen Frauen, Paare und Kinder unnotigen gesundheitlichen Risiken aus, erschwert paradoxerweise die Durchsetzung von Kinderrechten und erzeugt Gerechtigkeitsprobleme und Rechtsunsicherheit fur die betroffenen Paare und die behandelnden Arztinnen und Arzte. Das Embryonenschutzgesetz enthalt zudem nur strafrechtliche Verbote. Diese erlauben keine angemessene Reaktion auf die medizinische Entwicklung und den gesellschaftlichen Wandel und werden der Komplexitat der Materie nicht gerecht. Diese Probleme mussen gelost werden. Der Bundesgesetzgeber verfugt seit mehr als 20 Jahren uber die Kompetenz zur Regelung der Fortpflanzungsmedizin. Er sollte in der kommenden Legislaturperiode ein umfassendes Fortpflanzungsmedizingesetz schaffen.

Classen-Linke I, Moss S, Groting K, Beier H M, Alfer J & Krusche C A (2012) Histopathology 61, 955–965 Mammaglobin 1: not only a breast-specific and tumour-specific marker, but also a hormone-responsive endometrial protein Aims: The secretoglobin mammaglobin 1 (MGB1) is strongly expressed in breast tumours, and is therefore used to detect breast cancer metastases, although it has also been detected in other tissues. The aim of this study was to examine MGB1 expression and its hormonal regulation in human endometrium to further investigate the use of MGB1 as a marker molecule. Methods and results: Mammaglobin 1 expression was assessed immunohistochemically in endometrial samples from 60 normal fertile patients throughout the menstrual cycle, in 49 endometriotic tissue samples, in 15 endometrial adenocarcinomas, and in 36 breast carcinomas. In addition, 25 endometrial samples were analysed by western blot and quantitative real-time reverse transcription polymerase chain reaction. To prove hormonal regulation, primary endometrial epithelial cells were cultured with 17β-oestradiol and promegestone. MGB1 was detected in human endometrial tissue, with peak expression during the luteal phase, in 31% of endometriotic samples, in 53% of endometrial adenocarcinomas, and in 64% of breast carcinomas. MGB1 mRNA expression was increased in vitro by hormonal treatment. Conclusions: Our data show that MGB1 expression is not restricted to normal and malignant breast tissue. Besides its documented occurrence in endometriotic and malignant endometrial tissues, MGB1 is also expressed in normal human endometrium, and such expression is controlled by steroid hormones.

Objective: to compare the assessment of endometrial maturation parameters in endometrial secretion samples obtained by a novel minimally invasive technique with those assessed in tissue biopsies. Design: prospective study. Setting: university hospital. Population: healthy female volunteers attending a gynaecological outpatient clinic. Methods: endometrial secretion fluid and tissue sampling 5 days after a spontaneous ovulation assessed with ultrasound. Main outcome measures: progesterone (P) receptor, Ki-67 expression and the Noyes criteria were used to date endometrial biopsies. In the endometrial fluid samples, glycodelin A (GdA), leukaemia inhibitory factor (LIF) and P levels were analysed, and protein content and electrophoresis patterns were determined. RESULTS: All data were correlated to estradiol (E2) and P serum concentrations. The dating according to histology and immunohistochemical staining patterns correlated significantly with GdA levels (r=0.376, P=0.048) in endometrial fluid samples as well with serum levels of E2 (r=0.568, P=0.001) and P (r=0.408, P=0.023). No correlation was observed between tissue dating and LIF levels and protein content in endometrial fluid samples. Conclusions: the measurement of GdA in endometrial secretion samples may provide a less invasive method for assessing endometrial maturation in potential conception cycles without disrupting implantation.

The objective of this study was to investigate the effect of ovarian stimulation for IVF on endometrial secretion and tissue markers of receptivity in the mid-luteal phase. In 10 oocyte donors, endometrial secretions and biopsies were sampled 5 days after spontaneous ovulation and oocyte retrieval in consecutive cycles. Four subjects received progesterone in the luteal phase of the stimulated cycles. Mid-luteal endometrial maturation in the stimulated cycle was compared with the spontaneous cycle, by histological dating, Ki-67, oestrogen receptor (ER) and progesterone receptor (PR) expression, secretion levels of leukaemia inhibitory factor (LIF), glycodelin A (GdA) and progesterone, and protein profile. No significant differences in histological markers, expression of Ki-67, PR, ER, secretion protein profiles or concentrations of LIF, GdA, or progesterone were observed when comparing natural with stimulated cycles. Progesterone supplementation of stimulated cycles was associated with significantly lower Ki-67 (P = 0.03) and ER (P = 0.04) expression compared with the non-supplemented stimulated cycle. In this pilot study, ovarian stimulation was not demonstrated to alter the studied markers of endometrial maturation in the mid-luteal phase.

Objective To study the mRNA expression of the two leucine-rich repeat-containing G-protein-coupled receptors LGR-4 and LGR-5 and the mRNA and protein expression of LGR-7, the relaxin receptor, in the human cyclic endometrium. Design Retrospective study. Setting Department of Anatomy and Reproductive Biology, Rheinisch-Westfalische Technische Hochschule Aachen, Aachen, Germany. Method(s) LGR-4, -5, and -7 mRNA expression was assessed by semiquantitative and real time reverse transcription–polymerase chain reaction in the endometrium of premenopausal women (n = 26) and cultured primary endometrial epithelial cells and fibroblasts (n = 3). Transcript size was determined by Northern blotting. LGR-7 protein expression was assessed by immunohistochemistry. Result(s) The mRNA of LGR-4, LGR-5, and LGR-7 was expressed constitutively throughout the menstrual cycle in the endometrium, and characterized by substantial differences in expression levels of individual women. LGR-7 immunostaining was detected in the epithelium of the functional layer throughout the cycle, with lowest staining in the midproliferative phase. Furthermore, individual stromal cells of the functional layer and the stroma of the basal layer showed LGR-7 immunostaining. Conclusion(s) Endometrial expression of the mRNA of orphan receptors LGR-4 and LGR-5 implies that the endometrium is potentially influenced by as yet unknown mediators, which are possibly involved in fertility control. Furthermore, we confirmed constitutive endometrial mRNA expression of LGR-7, the classical relaxin receptor, and demonstrated specific LGR-7 immunostaining of different endometrial cell types, which suggests a physiological role of relaxin in the human endometrium.

Many mammary tumors express estrogen receptors (ER) and progesterone receptors (PR), and there is increasing evidence that progestins influence gene expression of breast tumor cells. To analyse the impact of progestins on breast cancer cells, we compared (a) the expression of two cytokines, involved in tumor progression, and searched (b) for differentially regulated genes by a microarray, containing 2400 genes, on T47D breast cancer cells cultured for 6 days with 17β-estradiol (E 2 ) or E 2 + medroxyprogesterone acetate (E 2 + MPA). Lower amounts of PDGF and TNFα were found in culture supernatants of E 2 + MPA treated T47D cells. MPA addition induced a 2.8–3.5-fold increase of the mRNA expression of (a) tristetraprolin, which is involved in the posttranscriptional regulation of cytokine biosynthesis, and (b) zinc-α2-glycoprotein and Na, K-ATPase α1-subunit, which both resemble differentiation markers of breast epithelium. In contrast, the mRNA expression of lipocalin 2, which promotes matrixmetalloproteinase-9 activity, was decreased five-fold in E 2 + MPA treated cells. Our data show that the expression of genes from various functional gene families is regulated differentially by E 2 and E 2 + MPA treatment in T47D cells. This suggests that exogenous progestins applied for therapy and endogenous changes of the progesterone levels during the menstrual cycle both influence breast cancer pathophysiology.

Uteroglobin (UG) is a conserved protein which is induced by progesterone and secreted by the epithelia of various mammalian reproductive and respiratory organs. Recombinant bovine uteroglobin (recbUG), consisting of 80 amino acids with a C-terminal His6 tag, was overexpressed in Escherichia coli and purified. The protein was crystallized in two geometric forms, rhomboid and cuneate (wedge-shaped), by the hanging-drop vapour-diffusion method at 295 K. The rhomboid crystals diffracted to a maximum resolution of 1.6 A using synchrotron radiation. These crystals belong to space group P2(1)2(1)2, with unit-cell parameters a = 81.42, b = 82.82, c = 45.26 A, and contain four monomers per asymmetric unit. The cuneate crystals diffracted to 2.35 A resolution using a rotating-anode generator. These crystals belong to space group C222(1), with unit-cell parameters a = 43.39, b = 93.94, c = 77.30 A, and contain two molecules per asymmetric unit.

Impaired histone acetylation was recognized to be involved in carcinogenesis. Furthermore, histone deacetylase (HDAC) inhibitors induce differentiation of breast cancer cells and inhibit tumour growth. These results prompted us to study HDAC-1 and -3 expression in breast tumours to establish their potential therapeutic and prognostic significance. HDAC-1 und HDAC-3 protein expression was analyzed immunohistochemically on a tissue microarray (TMA) containing 600 core biopsies from 200 patients. HDAC-1 and -3 expression was correlated to steroid hormone receptor-, Her2/neu- and proliferation status of tumours as well as to overall and disease free survival. Moderate or strong nuclear immunoreactivity for HDAC-1 was observed in 39.8% and for HDAC-3 in 43.9% of breast carcinomas. HDAC-1 and -3 expression correlated significantly with oestrogen and progesterone receptor expression (both p< 0.001). HDAC-1 expression predicted significantly better disease free survival (DFS: p=0.044), in particular, in patients with small tumours of all differentiation types (DFS: p=0.016). Multivariate analysis demonstrated that HDAC-1 is an independent prognostic marker. Our data suggest that evaluation of HDAC-1 protein expression enables a more precise assessment of the prognosis of breast cancer patients. Thus, HDAC-1 expression analysis might be clinically useful to facilitate an individual, risk-directed, adjuvant systemic therapy in breast cancer patients.

BACKGROUND: Evidence is emerging that haptoglobin, an acute phase protein with immunomodulatory properties, is expressed by the endometrium of various species. The present study describes an in-depth investigation of haptoglobin expression and release in the rabbit reproductive tract and in preimplantation embryos. METHODS: The full-length cDNA sequence of rabbit haptoglobin was determined by rapid amplification of cDNA ends PCR. Haptoglobin expression was studied in the oviductal ampull, and isthmus, endometrium and embryos from the time of ovulation up to adhesion. These results were completed by western blot analysis of reproductive tract secretions and embryonic tissues. RESULTS: cDNA sequencing showed a high homology between rabbit and human haptoglobin (84.1%). In oviductal tissues haptoglobin mRNA is clearly expressed from 6h post-conception (p.c.) to day 3, and in the uterus on days 5 and 6. In the oviductal fluid highest haptoglobin protein content was found between 6h p.c and day 2, and in the uterine fluid on days 5 and 6 p.c. Embryos do not express haptoglobin mRNA during preimplantation development. However, considerable amounts of maternal haptoglobin protein were detected in the blastocyst coverings and in blastocyst fluid. CONCLUSIONS: Already during periovulatory time and oviductal passage, high amounts of haptoglobin are present in the microenvironment surrounding the oocyte/embryo. Two days before implantation, again, high haptoglobin levels are detectable in the embryo’s environment. The incorporation of haptoglobin into the extra-embryonic matrix may be of particular functional significance.

Embryo implantation and subsequent decidualization, trophoblast invasion and formation of a functional placenta are crucial for establishment and maintenance of pregnancy. Interleukin-11 signalling has been shown to be obligatory for adequate decidualization and trophoblast invasion in mice. Defects in IL-11 signalling in mice result in trophoblast over-invasion and fetal loss. The pathological situation of human tubal pregnancy resembles that of IL-11Ralpha(-/-) mice concerning these symptoms. As our interest is focused on the human early pregnancy, we compared IL-11 expression at the implantation site of ectopic tubal pregnancy (EP) to 1st and 2nd trimester of normal intrauterine pregnancies (IP), and to the normal cycling endometrium. The mRNA expression of IL-11 and IL-11Ralpha was analysed by semiquantitative RT-PCR. Protein expression was detected by western blotting and immunohistochemistry. IL-11Ralpha is expressed constitutively in all tissue specimens analysed. IL-11 is expressed predominantly during follicular and early luteal phase of the menstrual cycle. In IP, IL-11 expression peaks during the 1st trimester and declines from the beginning of the 2nd trimester onwards. In tubal abortions, IL-11 expression is reduced in comparison to vital EP and IP. Cultured primary endometrial and decidual epithelial cells were analysed for hormonal regulation of IL-11 by enzyme-linked immunosorbent assay and RT-PCR. IL-11 is up-regulated by estrogen and down-regulated by progesterone. Overall, our results indicate that in humans, IL-11 signalling is significantly involved in regulation of trophoblast invasion. In the case of tubal abortion, inadequate IL-11 signalling may therefore result in dysregulation of trophoblast invasion.

The transmembrane protein gp130 plays a central role in cytokine action as a signal transducing receptor subunit common to all interleukin-6 type cytokines. Endometrial tissue obtained from women with a normal menstrual cycle and decidua obtained from women in the first or second trimester of pregnancy were assessed for gp130 by western blotting, immunohistochemistry and enzyme-linked immunosorbent assay (ELISA) analysis. By immunoblotting, two forms of gp130 were detected: one-the soluble form-of approximately 100 kDa and a larger membrane-bound form of approximately 150 kDa. The latter became clearly visible in the mid to late secretory phase and was more pronounced in decidual tissue of second trimester compared to first trimester. Immunohistochemically, gp130 was located in glandular epithelial cells during the mid to late secretory phase, whereas staining in the proliferative phase was rather weak. In first and second trimester decidua, glandular cells were also positively stained. In addition, the invading trophoblast cells were gp130 positive. Soluble gp130 release was measured in the supernatants from primary endometrial and decidual cell cultures by ELISA and reached maximum values in cell cultures without addition of hormones. In cultured endometrial epithelial cells obtained during the proliferative phase of the cycle, the soluble gp130 release increased significantly under combined estradiol/progesterone supplementation which mimics the secretory phase conditions compared to estradiol supplementation alone. In cultured epithelial cells derived from decidual tissue of first trimester of pregnancy, similar effects of hormonal regulation were observed. Our results suggest that the balance between soluble gp130 and its membrane-bound form may play an important role in regulating cytokine action necessary for blastocyst implantation and for further interaction between the decidualized endometrium and the invading trophoblast.

Aus Anlass der Veroffentlichung des ersten Tatigkeitsberichts der Zentralen Ethik-Kommission beim Robert-Koch-Institut werden aktuelle Aspekte zur Forschung mit embryonalen Stammzellen in Deutschland berichtet. Insbesondere werden die mit weltweiter Aufmerksamkeit verfolgten neuesten Befunde uber die Differenzierung von embryonalen Stammzellen der Maus zu Spermien und Eizellen dargestellt. Diese Befunde geben erneut Diskussionsanstose, uber den Status der embryonalen Stammzellen mit Blick auf die deutsche Gesetzeslage nachzudenken. Die wissenschaftliche Diskussion zeigt indessen, dass eine Anderung der wissenschaftlichen Einschatzung, dass alle embryonalen Stammzellen pluripotent sind, keiner Revision bedarf. Die sprachliche und terminologische Klarheit wird erneut als wesentlicher Beitrag fur jede ethische und rechtliche Beurteilung angesehen. Die offentliche Debatte sollte verantwortungsvoller Forschung Raum geben, um kunftige ethische und rechtliche Entscheidungen auf dem Boden gesicherten Wissens zu treffen.

During the first trimester of pregnancy extravillous trophoblast cells (EVT) invade the maternal decidua. Invasion normally is reduced from the second trimester onwards and stops in the inner third of the myometrium. By contrast, in extrauterine tubal pregnancy, trophoblast invasion may even penetrate the tubal wall, which ultimately leads to the rupture of the fallopian tube. Induction of apoptosis of EVT cells, by maternal immune competent cells, may be an important mechanism to limit EVT invasion in uterine pregnancy. Tissue specimens from first and second trimester uterine pregnancy and first trimester tubal pregnancy were analyzed for apoptosis by TUNEL- and M30-staining. By immunohistochemical double labelling, maternal leukocyte subtypes were co-localized to apoptotic cells and in this context, the number of CD56(+)NK cells was analyzed. Our data show that apoptosis is confined to the decidua basalis. Most apoptotic cells are single cytokeratin-positive epithelial cells residing in the stromal compartment. Consequently these cells can only be EVT cells. Maternal leukocytes are not apoptotic. They are located in close contact to apoptotic cells. The number of apoptotic cells in the second trimester (1.8+/-0.7 per cent) is reduced compared to first trimester (5.6+/-0.7 per cent) of uterine pregnancy. In parallel, the number of NK cells declines from first (24.4+/-2.9) to second (12.4+/-1.8) trimester. Furthermore, apoptosis is significantly reduced in ectopic (0.9+/-0.3 per cent) compared to eutopic first trimester pregnancies. Consequently, we suggest that in first trimester uterine pregnancy, induction of EVT cell apoptosis by the maternal immune system is one mechanism to limit EVT invasion. During the second trimester, in parallel to declining numbers of NK cells, the mechanism changes. However, in tubal pregnancy due to differing immunological microenvironments at the ectopic implantation site, apoptosis induction fails, which deleteriously may result in uncontrolled invasion and penetration of the tubal wall.

Early embryonic development, implantation and maintenance of a pregnancy are critically dependent on an intact embryo-maternal communication. So far, only few signals involved in this dialogue have been identified. In bovine and other ruminants, interferon tau is the predominant embryonic pregnancy recognition signal, exhibiting antiluteolytic activity. However, this is just one aspect of the complex process of embryo-maternal signalling, and a number of other systems are more likely to be involved. To gain a more comprehensive understanding of these important mechanisms, integrated projects involving specialists in embryology, reproductive biotechnology and functional genome research are necessary to perform a systematic analysis of interactions between pre-implantation stage embryos and oviduct or uterine epithelial cells, respectively. State-of-the-art transcriptomic and proteomic technologies will identify reciprocal signals between embryos and their maternal environment and the respective downstream reaction cascades. For in vivo studies, the use of monozygotic twins as recipient animals provides elegant model systems, thus eliminating genetic variability as a cause of differential gene expression. In addition, suitable systems for the co-culture of oviduct epithelial or endometrium cells with the respective embryonic stages need to be established for functional validation of candidate genes potentially involved in the dialogue between embryos and their maternal environment. The knowledge of these mechanisms should help to increase the pregnancy rate following embryo transfer and to avoid embryonic losses. Candidate genes involved in embryo-maternal communication will also be used to define new quality criteria for the selection of embryos for transfer to recipients. Another application is the supplementation of embryotrophic factors or components of embryo-maternal signalling in optimized formulations, such as bioartificial matrices. As a long-term goal, signalling mechanisms identified in bovine will also be functionally evaluated in other species, including the human.

Objective To compare cytokine expression profiles of decidua basalis (containing trophoblast cells) and decidua parietalis (without trophoblast cells) for determination of microenvironments in human first trimester decidua. Design Retrospective study. Setting School of Medicine, RWTH University of Aachen, Aachen Germany, and Bourgognekliniek Maastricht, Maastricht, The Netherlands. Patient(s) Forty-six women who had undergone elective first-trimester termination of viable pregnancy at 5 to 12 weeks. Main outcome measure(s) Quantitative cytokine protein analysis in decidual tissues by enzyme-linked immunosorbent assay, qualitative cytokine messenger (m)RNA analysis in isolated decidual cell samples, and comparative mRNA and protein analysis in tissues of decidua basalis compared with decidua parietalis. Result(s) Interleukin-2, interferon-γ (Th-1), interleukin-4 (Th-2), and interleukin-1β proteins are expressed in the human first-trimester decidua. Interleukin-2, interferon-γ, and interleukin-4 mRNA mainly derive from the decidual tissue leukocytes. Interleukin-1β mRNA is expressed by all decidual cell types. Interferon-γ mRNA and protein is detected predominantly in the decidua basalis, which contains trophoblast cells. Conclusion(s) Microenvironments are established topographically by different expression of cytokines in decidua basalis and decidua parietalis. These locally specific patterns are indicative of fetomaternal cross-talk. Higher interferon-γ concentrations in decidua basalis may influence leukocyte differentiation (e.g., macrophage activation) and trophoblast invasion (e.g., by induction of expression of major histocompatibility complex).

Die individuelle Entwicklung beginnt mit einer befruchteten Eizelle, die bereits die gesamte genetische Information fur die Ausbildung eines jeden Zelltyps enthalt. Das humane Genom beinhaltet nach derzeitiger Schatzung ca. 35.000 Gene, die fur die Differenzierung von mehr als 200 histologisch definierten Gewebetypen verantwortlich sind. Differenzierung einer Zelle bedeutet, dass ein Grosteil des Genoms abgeschaltet wird. Der Differenzierungsprozess ist an den genauen Ablauf eines genetischen Expressionsprogramms gebunden, welcher jedoch unter epigenetischer Kontrolle steht. Auf diese Weise wird ein molekulares Gedachtnis geformt, welches die Differenzierung einer jeden Zelle definiert. Hierbei wird nicht die Basensequenz der DNS selbst verandert, sondern ihre Zugangigkeit wird uber DNS-Methylierung und Veranderungen der Chromatinstruktur beeinflusst. Diese Mechanismen werden bereits bei der Reifung der Keimzellen eingeleitet. Hierbei kommt es zu deutlichen Unterschieden im Umfang der Methylierung bei Spermien und Eizellen. Ein Teil der Methylierungen ist so fest, dass sie auch noch nach der Befruchtung und bei allen Folgezellen Bestand haben; diese werden als Imprints bezeichnet. In der fruhen Embryonalentwicklung finden weitere Veranderungen statt, wobei es zu typisch "mutterlichen" und typisch "vaterlichen" Genomunterschieden kommt. Entscheidend sind die Methylierung der DNS sowie die Methylierung oder Azetylierung der Kernproteine, besonders der Histone. Ob und wie diese Prozesse umkehrbar sind und ineinandergreifen ist derzeit ein zentrales Anliegen der Forschung, besonders im Zusammenhang mit den Klonierungsversuchen. Der schwierigste Schritt ist die Ruckfuhrung einer adulten Korperzelle auf die Entwicklungsstufe einer Zygote als Basis fur die Bildung verschiedener Gewebe oder eines Individuums, wie es erstmals bei dem Schaf Dolly erfolgreich durchgefuhrt wurde. Limitierender Faktor beim Klonen, also der Herstellung einer totipotenten Zelle aus einem somatischen Zellkern, der in eine enukleierte Oozyte transferiert wurde, scheinen epigenetische Vorgange zu sein. Fehlsteuerungen in den epigenetischen Regulationsmechanismen konnen schwerwiegende Folgen, wie zum Beispiel Schizophrenie, Immunkrankheiten oder Krebserkrankungen, haben.

Objective: Midcyclic cervical dilatation in its basic mechanisms is thought to resemble cervical dilatation during parturition, where an infiltration of the cervical stroma and the activation of matrix metalloproteinases is known to play an important role. In this study we have investigated the presence and localization of matrix metalloproteinases (MMP)-2 and -9 in the human uterine cervix across the menstrual cycle. Methods: Samples of tissue from human uterine cervix were obtained from specimens from 14 premenopausal patients undergoing hysterectomy (6 were removed during follicular phase [day 1-11], 4 in the periovulatory phase [day 12-16], 4 in the secretory phase [day 17-28]). Paraffin embedded slides were stained with a monoclonal antibody against MMP 2 and MMP 9. The relative intensity of the staining reaction was described by two independent researchers and classified in semiquantitative categories (- negative; + faint; + + moderate; + + + strong). Results: MMP 9 was immunolocalized in different cellular compartments of the tissue: glandular epithelium, vascular endothelium, stroma and macrophages. An increase of MMP 9 was detected only in glandular epithelium during periovulatory phase. In vascular endothelium and macrophages MMP 9 was present in all phases of the menstrual cycle in an equal intensity of staining reaction. MMP 2 was immunolocalized in the glandular epithelium of the follicular and secretory phase in a moderate intensity, while the cervical stroma showed only a faint staining reaction for MMP 2. Conclusion: The finding of an increase of MMP 9 in glandular epithelium during periovulatory phase is consistent with the involvement of MMP 9 in the mechanisms of midcyclic cervical dilatation. At the same time the rather unspecific expression of MMP 2 and MMP 9 in all phases of the menstrual cycle indicates that midcyclic cervical dilatation may depend on the involvement of several, hormonally regulated mediators. Further studies evaluating the mechanisms are required.

Preimplantation embryos of several species are surrounded by an extraembryonic matrix (often simply named zona pellucida) until briefly before implantation. All signals of the early embryo-maternal dialogue have to pass this matrix and therefore are detectable inside. We investigated the protein pattern of the extraembryonic matrices of 3-6-day-old rabbit embryos by two-dimensional gel-electrophoresis. Using (35)S-methionine incorporation, embryonic proteins were labelled and could be distinguished from maternal proteins. Furthermore, the presence of three different proteins (insulin-like growth factor-binding protein-3, uteroglobin, haptoglobin) within the matrices of day-6 embryos was investigated by Western blot analysis. The pattern and numbers of protein spots detected was clearly dependent on the time of embryonic development. Of all proteins detected, 19.3% and 33% are of embryonic origin (day 5 and day 6, respectively). At day 4 the zona proteins are no longer detectable, reflecting the degradation of the zona pellucida. From day 4 to day 5 proteins detectable within the extraembryonic matrices increase enormously. This demonstrates that embryo-maternal signalling accelerates at least 2 days before implantation. Insulin-like growth factor-binding protein-3, uteroglobin and haptoglobin are part of the early signalling as shown by Western blot analysis. Insulin-like growth factor-binding protein-3 could be detected as one spot at 38 kDa pI 6.1, uteroglobin at 8 kDa pI 6.0 and haptoglobin as two spots/isoforms at 36/38 kDa pI 5.8 and pI 6.0. These results demonstrate that extraembryonic matrices serving as a mailbox are a valuable tool for investigating early embryo-maternal signalling.

In diesem Jahr erinnern wir uns daran, dass der 1792 in Estland geborene Karl Ernst von Baer vor 175 Jahren in Konigsberg die Eizelle der Saugetiere und des Menschen entdeckte. Diese Entdeckung stellt einen Meilenstein in der Geschichte der Embryologie und Reproduktionsbiologie dar. Sie machte der grotesken Praformationstheorie ein Ende, die nach Entdeckung der Spermien 1677 zu bluhen begann, indem sie ein vollkommen praformiertes Menschlein in die Samenzelle projizierte. Karl Ernst von Baer bezeichnete jedoch die von ihm 1827 entdeckten “Eier” noch nicht als “Zellen”, da erst 12 Jahre spater die Definition der Zellen als kleinste Einheiten biologischer Gewebe und Organismen durch Theodor Schwann und Mathias Jakob Schleiden gegeben wurde. Dennoch, die Entdeckung der Eizelle bedeutete den Beginn einer neuen,ausgewogenen Betrachtung der Entstehung der menschlichen Embryonalentwicklung, die nun auf weibliche und mannliche Keimzellen als Ursprunge gleichermasen zuruckgefuhrt wurde.

Following attenuation of progesterone production corpora lutea are selectively cleared, a process associated with recruitment of macrophages. In the rabbit little is known about luteal immune cell phenotypes and expression of cytokines, which influence immune cells and resident luteal cells, during luteolysis. Consequently, we studied luteal immune cells by immunohistochemistry as well as luteal IL-10, TNFalpha, MCP-1, IFN-gamma, and IL-1beta mRNA expression by semiquantitative RT-PCR from day 8 to day 20 in pseudopregnant rabbits (d8-d20 p.hCG). Luteal function was assayed by serum progesterone levels. Functional luteolysis commenced by d14 p.hCG as indicated by attenuation of serum progesterone levels. X4(+) tissue macrophage levels increased transiently on d12 and d14 p.hCG, whereas CD5(+) T-cell levels transiently declined on these two days. CD68(+) macrophages increased progressively after d16 p.hCG. The luteal mRNA level of the anti-inflammatory cytokine IL-10 as well as the mRNA levels of the pro-inflammatory cytokines TNFalpha and MCP-1 increased after d16 p.hCG and remained elevated up to d20 p.hCG. IFN-gamma and IL-1beta mRNA expression did not vary systematically. In summary, luteolysis was associated with an initial transient increase of X4(+) macrophages and decrease of CD5(+) T-cells, and later recruitment of CD68(+) macrophages. During structural regression pro- and anti-inflammatory cytokines are upregulated possibly to control immune cell function.

Objective:To determine the localization and concentrations of estrogen receptor α and progesterone receptors A andB in the lower uterine segment during term parturition.Methods:Biopsies were taken from 70 patients during nonelective cesarean delivery. The patients were at different stages of cervical dilatation ( 6 cm) and different duration of labor (≤6 hours, >6-12 hours, >12 hours). The receptor concentrations were determined with solid phase immunoassays, and their localization was investigated immunohistochemically.Results:Estrogen receptor α concentration decreased significantly from 2.12 fmol/mg protein at less than 2 an dilatation to 1.08 fmol/mg (4-6 cm) but tended to increase at greater than 6 cm. Progesterone receptor A and B concentration was 84.7 fmol/mg at less than 2 cm dilatation, decreased significantly to 36.6 fmol/mg (2-3.9 cm), and increased again with further dilation. Concentrations of both receptors did not depend on duration of labor. By immunohistochemistr...

Die offentliche Diskussion uber die Forschung an menschlichen embryonalen Stammzellen hatte mit der jungsten Stellungnahme der Enquetekommission des Deutschen Bundestages “Recht und Ethik in der modernen Medizin”, dem Votum des Nationalen Ethikrates und der Stellungnahme der Zentralen Ethikkommission bei der Bundesarztekammer einen Hohepunkt erreicht, der endlich zu einer politischen Debatte und einer Entscheidung im deutschen Bundestag fuhrte (30. Januar 2002). Es ist bei der aktuellen internationalen Entwicklung terroristischer und kriegerischer Auseinandersetzungen mehr als verstandlich, dass das Parlament jungst wichtigere Entscheidungen treffen musste. Dennoch war es fur die Gesellschaft und fur die Wissenschaft gleichermasen wichtig, dass sich die Politik mit einem klaren Votum zumindest fur die nachsten 2–3 Jahre festlegt hat. Da in der offentlichen Debatte die Argumente selbst klugster Kopfe durch Zuwarten offensichtlich nicht besser werden, und da selbst einige der klugsten Kopfe der Politik nicht gewillt zu sein scheinen, den Erkenntnissen der biologischen und embryologischen Wissenschaften ihre Aufmerksamkeit zu schenken, war eine Entscheidung im Parlament daruber fallig, ob legale Importe von menschlichen Stammzelllinien verwirklicht werden durfen, obwohl ethische Gegenargumente in Deutschland noch langst nicht ausgeraumt sind. Fur kunftige Entwicklungen wird jedoch die Gesellschaft eine Uberprufung der einschlagigen Gesetze (ESchG und § 218 StGB) einfordern, denn hochrangige Forschung an menschlichen embryonalen Stammzellen wird ohne die gesetzlich geregelte Spende von Embryoblastzellen aus verwaisten Blastozysten nicht durchfuhrbar.

The contemporary approach to ovarian stimulation for IVF treatment results in supraphysiological concentrations of steroids during the follicular and luteal phases of the menstrual cycle. These sex steroids act directly and indirectly to mature the endometrium, influencing receptivity for implantation. Corpus luteum function is distinctly abnormal in IVF cycles, and therefore luteal support is widely used. Various reasons may underlie the defective luteal phase, including (i) ovarian hyperstimulation per se, (ii) gonadotrophin-releasing hormone (GnRH) analogue co-treatment and (iii) the use of human chorionic gonadotrophin (HCG) to induce final oocyte maturation. The recent introduction of GnRH antagonist co-treatment for the prevention of a premature LH rise during the late follicular phase allows for different approaches to ovarian stimulation for IVF. However, a recent meta-analysis showed that implantation rates may be compromised by using GnRH antagonists in currently employed regimens. The development of endometrium receptive to embryo implantation is a complex process and may be altered by inappropriate exposure to sex steroids in terms of timing, duration and magnitude. New approaches to the assessment of endometrial receptivity are now required. Novel approaches to ovarian stimulation aimed at adjusted GnRH antagonist regimens and achieving a more physiological luteal phase endocrinology are now appearing in the literature and may represent an important step in the improvement of the overall health economics of IVF.

Objective: Around the time of ovulation the cervix opens and the cervical mucus liquefies. Vascular endothelial growth factor (VEGF), a potent inductor of vascular permeability, may play a role in these changes. We examined VEGF in cervical tissue specimens and cervical mucus at different stages of the menstrual cycle. Methods: Samples of tissue and mucus from the uterine cervix were obtained from specimens from 20 premenopausal patients undergoing hysterectomy. Eight uteri were removed during the follicular phase (day 1-8), five in the periovulatory phase (day 12 - 16), and seven in the secretory phase (day 17-28). Paraffin-embedded slides were stained with a VEGF antibody covering the splicing variants 165,189 and 121. Cervical mucus was examined for VEGF 165 with an enzyme-linked immunoassay. Data were analyzed with the Wilcoxon two-sample test. Results: Uteri in the early proliferative phase showed distinct VEGF staining of the basal epithelium of the cervix. During the late follicular and periovulatory phases, staining in the apical epithelium and cervical stroma increased and the VEGF concentration in the cervical mucus was highest (97 pg/mg total protein). After ovulation VEGF in the epithelium fell sharply, to then reappear in the mid and late secretory phase. Conclusion: VEGF increases in the cervical stroma around the time of ovulation and may play a role in the liquefaction of the cervical mucus and tissue edema. These changes are likely involved with the opening of the cervix at near the time of ovulation.

Objective: To distinguish endocrine and paracrine influences on leukocyte subpopulations at uterine and tubal implantation sites. Design: Retrospective immunohistochemical study. Setting: Departments of Anatomy, and Obstetrics and Gynecology, School of Medicine, RWTH University of Aachen, Aachen, Germany. Patient(s): Ten women with a viable ectopic pregnancy (EP), 25 women who had undergone elective first-trimester termination of pregnancy, and 4 women who had undergone hysterectomy with adnexectomy. Intervention(s): None. Main Outcome Measure(s): Quantitative analysis of leukocyte subpopulations at the implantation sites and their corresponding noninvaded tissues, decidual tissue from patients with EP, and tubal mucosa from normal menstrual cycle. Result(s): Similar numbers and characteristic distribution patterns of macrophages, T cells, and B cells were found at both normal intrauterine and tubal implantation sites. Natural killer (NK) cells were always absent from tubal mucosa. The number and distribution of leukocytes within decidual tissue from women with EP corresponded to those in the noninvaded decidual compartment in intrauterine pregnancy (IUP). Conclusion(s): Leukocyte populations present in the tubal and uterine mucosa are an intrinsic characteristic of these tissues. The distinct leukocyte distribution pattern at the implantation sites suggests that the invading trophoblast exerts a paracrine influence on endometrial and endosalpingeal leukocytes. The absence of natural killer cells from the tubal wall may be one reason for the higher degree of invasiveness of the trophoblast at the tubal implantation site.

Die embryonale Morphogenese wird uber Entwicklungskontrollgene, zu denen die sog. Hox-Gene gehoren, gesteuert. Alle Hox-Gene weisen eine hochkonservierte DNA-Sequenz auf, die als Homoobox bezeichnet wird. Der Begriff Homoosis bezeichnet die Transformation der Struktur eines Korpersegments in die homologe Struktur eines anderen Korpersegments: Eine homootische Transformation kann durch Mutation oder ektope Expression auftreten und ist erstmals bei der Taufliege Drosophila melanogaster beschrieben worden. Da Hox-Gene in der Evolution stark konserviert sind, gibt es zwischen der Drosophila-Embryogenese und der Wirbeltier-Embryogenese bemerkenswert enge Parallelen. Drosophila stellt somit ein universelles aber einfacheres Modell fur die molekulare Genetik der embryonalen Musterbildung dar. Entsprechend sind die Hox-Gene auch bei den Wirbeltieren (z. B. Maus, Mensch) entscheidend fur die Ausbildung der anterior-posterior ausgerichteten Korperachse. Nicht nur die Korperachse wird durch Hox-Gene in ihrer Entwicklung kontrolliert, sondern auch der Reproduktionstrakt, im weiblichen Geschlecht die Entwicklung der Muller-Gange. Hierbei spielen vor allem die dem Abdominal-B-Gen (Abd-B) von Drosophila homologen Hox a-9, Hox a-10, Hox a-11 und Hox a-13 Gene eine bedeutende Rolle. Diese Gene werden entsprechend ihrer Anordnung auf dem Chromosom 7 in gleicher Weise von anterior nach posterior in Oviduct, Uterus, Zervix und Vagina exprimiert (Prinzip der Kolinearitat). Taylor et al. (1997) konnten nachweisen, dass auch in der adulten Maus sowie beim Menschen diese Expression der Hox-Gene erhalten bleibt und ihre regelrechte Expression eine wichtige Rolle fur die Funktion der adulten Organe, so z. B. auch fur die Implantation der Blastozyste, spielt. Folglich sind die Hox a-10- und Hox a-11-knock-out-Mause aufgrund einer gestorten Dezidualisierung infertil (Hox a-11) oder vermindert fertil (Hox a-10). Die Expression der Hox-Gene kann durch Steroidhormone beeinflusst werden. Dieser Einfluss wirkt sich auf die Entwicklung des Reproduktionstraktes aus, wenn DES in der fruhen Schwangerschaft appliziert wird. Diese Befunde liefern eine Erklarung fur die teratogenen Effekte von DES. Eine direkte Regulierung der Hox-Gen-Expression im Zyklus uber Steroidhormone zeigt die Relevanz dieser Entwicklungskontrollgene fur Wachstum und Differenzierung des Endometriums im Laufe des menstruellen Zyklus und als Vorbereitung fur die Implantation.

Biologisch ist die Reifung des Endometriums in jedem Zyklus darauf gerichtet, einer Blastozyste gunstige Bedingungen fur die Implantation zu bieten. Infertilitat und fruhes Ende einer Schwangerschaft beruhen nicht selten auf einer unvollkommenen Reifung des Endometriums. Bereits eine mangelhafte Rezeptivitat des Endometriums fuhrt zum Scheitern der Implantation. Um die endometriale Ursache einer Infertilitat zu erkennen, werden die normalen zyklischen Veranderungen des Endometriums studiert. Morphologische Veranderungen bilden bis heute in diesem Bemuhen der Gynakologen noch die Grundlage der klassischen histologischen Diagnostik nach Noyes et al. (1950). Da jedoch evident ist, dass molekulare Defizite des Endometriums sich nicht unmittelbar histologisch erfassen lassen, werden neue Methoden und signifikante Parameter gesucht, die diese Art funktioneller Defekte diagnostisch erfassen lassen. Histochemische Lokalisierungen von definierten Proteinen, von Adhasionsmolekulen und Zytokinen, erlauben bereits eine detailliertere und aussagekraftigere molekulare Analyse als es die klassische Morphologie ermoglicht. Uberzeugende Argumente sprechen inzwischen dafur, mit einfachen biochemischen Analysen die Proteine des Uterussekrets als weitergehende signifikante Parameter zu nutzen. Die elektrophoretische Auftrennung des Uterussekrets ergibt typische Proteinmuster, welche die zyklischen Funktionsphasen des Endometriums darstellen. Das adaquate Proteinmuster der Lutealphase ist als das Produkt eines rezeptiven Endometriums zu betrachten und reprasentiert das fur diese molekulare Analytik charakteristische „Implantationsfenster“. Es wird bereits 2 Tage post ovulationem exprimiert und bei ungestortem Zyklusverlauf 8 Tage aufrechterhalten (15.–24. Zyklustag).

The biological aim of the differentiation and maturation of endometrial tissue compartments during any menstrual cycle is the achievement of suitable conditions for blastocyst implantation and the establishment of pregnancy. Infertility and early embryonic loss are frequently caused by insufficient endometrial differentiation. Even any incomplete receptivity stage of the luteal phase endometrium will prevent attachment and implantation. We have studied the physiological changes throughout an endometrial cycle to elucidate causes of endometrial insufficiency leading to subfertility or infertility. Up to now, the histological changes described by Noyes et al. are understood as classical diagnostic approaches. However, evidence is accumulating that molecular deficits of endometrial differentiation are by no means detectable histologically, and consequently ask for the research on new diagnostic methods and parameters. There are histochemical localizations of specific protein molecules, adhesion molecules and cytokines, which permit by far more detailed and significant molecular analyses than any classical morphological means could yield. Moreover, there are convincing arguments to use further biochemical assessments on proteins of the uterine secretions as specific diagnostic parameters. The electrophoretical resolution presents typical protein patterns, which in turn can be interpreted as characteristic reflexions of the functional phases of the endometrial cycle. What is demonstrated as the so-called adequate luteal phase protein pattern clearly is the product of the receptive endometrium, reflecting the "implantation window". This is established already two days after ovulation and persists usually eight further days, if the endometrial cycle is undisturbed (15th to 24th day of the cycle).

Ovarian stimulation with gonadotropins (GN) during human in vitro fertilization and embryo transfer (IVF/ET) therapy alters the ovarian steroid output, especially that of progesterone. As a consequence, endometrial transformation is advanced, and embryo implantation is hampered. This study used the rabbit model to determine if the application of the progesterone antagonist (PA) onapristone (ONA) could retard endometrial development after GN-stimulation. Rabbits were GN-stimulated twice daily with 5 IU FSH and 5 IU LH on 3 consecutive days with a) hMG (n = 10) or b) with a mixture of recombinant FSH and LH (n = 10). The animals were then mated, and hCG was injected i.v. to ensure ovulation. This day is designated as day 0 post coitum (d 0 p.c.). On day 2 p.c., five animals of each group were treated with 20 mg ONA/kg body weight and five with vehicle for control. On d 5 p.c. endometrial transformation was analyzed by morphology, uteroglobin (Ugl)-mRNA expression, and proliferation. Embryos were flushed from the uteri. Their number and morphology was evaluated. The endometrium of GN-stimulated control animals demonstrated very long endometrial glands and narrow stromal septa. Ugl-mRNA expression was restricted to the cells at the bottom of the gland. 17.0 +/- 4.6% (mean +/- SD) of glandular cells and 6.0 +/- 5.3% of luminal epithelial cells proliferated. In ONA-treated animals, endometrial glands were significantly shorter, and the pattern of arborization was less pronounced. Endometrial gland cells and luminal epithelial cells expressed Ugl-mRNA. Furthermore, glandular and luminal cells proliferated with high intensity (38.6 +/- 6.8% and 36.4 +/- 9.3%, respectively). These results indicate that the status of endometrial differentiation was retarded after ONA-treatment. Nevertheless, the embryos of these ONA-treated animals were well developed. In conclusion, after GN-stimulation, ONA treatment retarded the advanced endometrial transformation in rabbits. Therefore, postovulatory administration of a PA might be a possible strategy to modulate the advanced endometrial development in IVF-cycles.

The influences of the synthetic progestin, medroxyprogesterone acetate (MPA), the progesterone receptor modulator J867, and the antagonist ZK137316 were studied in vitro on isolated endometrial epithelial cells, as well as endometrial fibroblasts. We evaluated the expression of estrogen receptor alpha (ER) and the progesterone receptor (PR) by RT-PCR. ER and PR were strongly expressed in the fibroblasts and epithelial cells under treatment with 10(-8) M 17beta-estradiol (E(2)). Treatment with 10(-6) M J867 or ZK137316 upregulated the PR expression as did E(2), in contrast to treatment with 10(-6) M MPA, which caused a downregulation of PR in epithelial cells, but not in fibroblasts. In addition, the vascular endothelial growth factor (VEGF) release into the cell culture medium was analyzed by a VEGF-ELISA. VEGF which plays an important role in angiogenesis, is regulated by steroid hormones as well as hypoxia. E(2) stimulates VEGF release into the medium in both cell types. MPA reduces VEGF release significantly in the fibroblast cell culture, but increases it in the epithelial cell culture. ZK137316, in the presence or absence of E(2), reduces VEGF release in fibroblast cell culture. J867 increases the VEGF production in fibroblasts only in the presence of E(2). Both compounds show no significant effects, compared to E(2), in epithelial cell culture. The different results for the epithelial cells and fibroblasts indicate that the pharmacological effects of PR modulators (PRMs) and progesterone antagonists (PAs) may be cell specific and depend on the presence or absence of partial progestagenic agonistic activities. This observation opens up new perspectives for various clinical applications.

Vom 24.–26. Mai 2000 fand in Berlin auf Einladung des Bundesministeriums fur Gesundheit ein Symposium mit 600 Teilnehmern zum Thema „Fortpflanzungsmedizin in Deutschland“ statt. Hintergrund fur diese Veranstaltung ist die politische Frage, ob wir in der Bundesrepublik eine Novellierung des Embryonenschutzgesetzes oder ein neues Gesetz brauchen, welches den gesamten Bereich der Fortpflanzungsmedizin regelt. Die erste von sieben Leitfragen dieses Symposiums beschaftigte sich mit der fundamentalen Frage, welcher Status dem noch nicht implantierten menschlichen Embryo biologisch, moralisch und rechtlich zugeschrieben werden musse. Die neuen Entwicklungen der Wissenschaft stellen eine Verwendung fruhester Embryonalstadien fur wissenschaftliche und therapeutische Ziele auch in Deutschland zur Diskussion. In England ist seit 1990 nach strenger Uberprufung durch eine gesetzlich eingerichtete Kommission, in welcher nichtmedizinisch ausgebildete und verantwortungsbewusste Laien die Mehrheit haben mussen, fur hochrangige Forschungs- und Therapieziele eine streng kontrollierte Verwendung von nichtimplantierten Embryonen moglich. Fur eine solche Entscheidung ist die Definition des Status des fruhen menschlichen Embryos eine essentielle Voraussetzung. Wenn in unserer Gesellschaft ein offener Diskurs uber den Status des noch nicht implantierten menschlichen Embryos gefuhrt werden soll, ist es nicht vertretbar, dass bestehende parlamentarische und gesetzgewordene Kompromisse (§ 218 StGB) zum unantastbaren Axiom erklart werden, zumal ein Teil dieses Kompromisses, wie die unwissenschaftliche Festlegung des Schwangerschaftsbeginns (Zeitpunkt der Implantation), in eklatantem Widerspruch zum Embryonenschutzgesetz und dem verfassungskonformen Beginn des Schutzes der Menschenwurde steht (Abschluss der Befruchtung). Fur die Definition des Status des Embryos hat Gleichstellung im Recht hochste Prioritat.

Advanced endometrial transformation often occurs in IVF and embryo transfer therapy after ovarian stimulation with gonadotrophins. One reason is probably the early rise in peripheral progesterone concentration after ovulation induction. Consequently, we studied in a rabbit model, whether the post-ovulatory application of the progesterone receptor antagonist, onapristone, could prevent such an advancement of endometrial transformation after stimulation with different gonadotrophin preparations. The inhibitory effect of onapristone on the endometrium is dependent upon the strength of ovarian stimulation. In unstimulated animals or animals treated with recombinant LH (nine corpora Iutea/animal in both groups), secretory differentiation and proliferation of the endometrium was strongly inhibited by onapristone. After weak ovarian stimulation with a 3:1 mixture of FSH and LH (22 corpora Iutea/animal), secretory differentiation was strongly inhibited, while proliferation was enhanced. After strong stimulation with either a 1:1 mixture of FSH and LH, or human menopausal gonadotrophin (HMG; >40 corpora lutea/animal), only limited inhibitory effects of onapristone on secretory transformation or proliferation could be detected. In conclusion, these graded effects of onapristone after stimulation with gonadotrophins, resemble the basic observations from which a therapeutic strategy emerges, to modulate the advanced endometrial transformation which occurs in many IVF patients after ovarian stimulation.

Leptin and its receptor are involved in endocrine and paracrine regulation of metabolism, obesity and reproduction. Here, we describe the detection of the functional long isoform receptor of leptin in human endometrium. The leptin receptor protein was shown to be expressed in glandular and luminal epithelium and is periodically regulated throughout the menstrual cycle, demonstrating main expression in follicular and mid-luteal phase. In contrast, leptin receptor mRNA is detectable by reverse transcription-polymerase chain reaction (RT-PCR) as a constitutive component. Since RT-PCR analyses showed that leptin is not expressed in this tissue, the present study suggests that the human endometrium is a novel target for leptin. Therefore, we investigated 11 subfertile patients who underwent two biopsies in one menstrual cycle. The patients presented with a repetitive endometrial maturation defect, but showed adequate serum hormone concentrations and normal steroid hormone receptor expression and down-regulation in the endometrium. These patients were, however, deficient for expression of the functional leptin receptor. These analyses provide evidence that the lack of the leptin receptor in an ovulatory cycle may contribute to subfertility by a yet undefined 'endometrial factor'.

Insulin-like growth factor-I (IGF-I) promotes early embryonic development in several species. In the rabbit, IGF-I binds to the embryonic coats from Day 3 of development onward by a 38-kDa protein that is probably insulin-like growth factor-binding protein 3 (IGFBP3). In the present study, ligand, Western, and Northern blot analyses were used to demonstrate the presence of IGF-I-binding activity, several immunoreactive IGFBP3 proteins, and IGFBP3 mRNA in horse conceptuses with particularly large amounts of immunoreactive IGFBP3 in the conceptus capsule. In addition, immunoprecipitation of radiolabeled proteins showed that cultured horse conceptuses secreted IGFBP3 into the culture medium. Endometrial samples from mares also contained IGFBP3 mRNA and protein; but there was no evidence of secretion of IGFBP3 into the uterine lumen by ligand blot analysis, and there was evidence of only very small amounts by Western blot analysis. These results indicate that the horse conceptus secretes significant quantities of IGFBP3 toward the conceptus capsule from as early as Day 10 after ovulation. Thus, most of the IGFBP3 contained within the capsule, which binds IGF-I to this special extracellular matrix of the preimplantation horse conceptus, is likely to be embryonic in origin. IGFBP3 in the horse conceptus capsule may enhance or modulate the action of IGFs on the developing conceptus.

Am 9. und 10. September 1999 fand im Genzentrum Munchen ein internationaler Workshop zum Thema ,,Stem cells and nuclear transfer strategies – present state and future prospects“ statt. Organisatoren und Chairmen waren Anna M. Wobus (IPK Gatersleben), Eckhard Wolf (Genzentrum Munchen) und Henning M. Beier (Anatomie und Reproduktionsbiologie der RWTH Aachen). International anerkannte Experten hielten folgende Vortrage: Jonathan Van Blerkom (Boulder, Co/USA) ,,The oocyte – the ultimate stem cell“, Austin Smith (Edinburgh/UK) ,,Control of stem cell pluripotency and differentiation“, Hans R. Scholer (Philadelphia, Pa/USA) ,,Oct-4 expression in ES cells and early embryogenesis“, Keith H. S. Campbell (Roslin/UK) ,,Viable offspring derived from fetal and adult mammalian cells – applications and progress“, Jose B. Cibelli (Worcester, Mass./USA) ,,Genetic modification by somatic cell nuclear transplantation“, Oliver Brustle (Bonn) ,,Transplantation of embryonic stem cell-derived neural precursors“, Anthony D. Ho (Heidelberg) ,,Symmetry of division of haematopoietic stem cells“, Axel Haverich (Hannover) ,,Modern strategies of cell and tissue repair – Requirements of transplantation therapy“. Bei diesem Workshop wurde eine Fulle von wissenschaftlichen Daten prasentiert, die das enorme Potential der embryonalen Stammzelltechnologie fur die zukunftige Gewebetransplantation deutlich machte. Uber 150 Wissenschaftler aus Deutschland, Europa und den USA nahmen an diesem Workshop teil.

Unsere Kenntnisse uber die Biologie des Progesterons und des Progesteronrezeptors (PR) sind in den letzten 10 Jahren immens gewachsen. Das Wissen uber die PR-Modulatoren, sowohl Agonisten als auch partielle und vollstandige Antagonisten wurde entsprechend vermehrt. Folglich ergibt sich heute ein grosses Potential medizinischer Anwendungen. Dieses reicht von der Behandlung spezifischer Erkrankungen, z. B. hormonabhangiger Karzinome und der Endometriose bis zur post-menopausalen Hormonsubstitutionstherapie, sowie neuer Methoden in der Fertilitatskontrolle. Die Erforschung der PR-Modulatoren war in den ersten Jahren nach Entdeckung dieser Molekule auf den Abbruch der Schwangerschaft gerichtet. Diese Anwendungsmoglichkeit erhielt eine viel zu grosse Aufmerksamkeit durch Medien und Interessengruppen. Die unangemessene Beachtung einer einzigen medizinischen Indikation hat die ubrigen Anwendungsbereiche der Antigestagene in ihrer Erforschung und Entwicklung nachhaltig behindert und blockiert. Gehen wir von einer kontinuierlichen Forschung und Entwicklung auf diesem Gebiet aus, so ist es sehr wahrscheinlich, dass die PR-Modulatoren signifikante Verbesserungen der gesundheitlichen Situation der Menschheit und segensreiche Therapiebeitrage erwarten lassen. Wegen dieser vorteilhaften gesundheitspolitischen Entwicklung erscheint es uns unethisch, wenn die vernunftigen medizinischen Forschungen und Entwicklungen in diesem Bereich nicht fortgesetzt werden.

Uteroglobin is a progesterone binding protein, a member of the antiflammin gene family and possibly a novel cytokine. Initially, uteroglobin was identified as the major protein of rabbit uterine secretion during the phase of preimplantation. Counterparts of the rabbit uteroglobin or its gene are described in rat, mouse, hamster, hare, pig, horse and human. While uteroglobin appears as one of the most extensively studied proteins, particularly its physico-chemical properties, including its crystal structure and its gene, the true physiological role of this protein still remains to be unravelled. Essential to understanding the significance of human uteroglobin in reproductive organs, particularly in the endometrium, is a knowledge of the spatial and chronological expression of this secretory protein. Our studies on 115 volunteers combined reverse transcription-polymerase chain reaction (RT-PCR), immunohistochemistry and quantitative assessment by an enzyme-linked immunosorbent assay for uteroglobin. The expression, localization and release of uteroglobulin in the human endometrium are presented. Secretory uteroglobin is found in endometrial tissue homogenates in highest levels of expression during the early luteal phase (days 15-19, 340 pg/mg total protein). In turn, uteroglobin is released into the uterine lumen in peak amounts during the receptive phase of the menstrual cycle (mid-luteal phase, days 20-23, secretion level 833.4 pg/mg total protein). Our immunohistochemical studies match with these results, as uteroglobin is located during the early and mid-luteal phase in the apical compartments of endometrial gland cells. These observations strongly suggest an involvement of uteroglobin in endometrial preparations for implantation.