Biomedical subjects
Publications and source records attributed to Klaus Diedrich.
We explored the association of the PPAR-gamma2 (peroxisome proliferator-activated receptor) Pro-12-Ala polymorphism with endometriosis in a case-control study with 51 women with endometriosis stages I-IV and 55 control women without endometriosis. The 12-Pro allele of PPAR-gamma2 may have protective effects avoiding the development and progression of endometriosis.
With a prevalence of 5%-10% the polycystic ovary syndrome (PCOS) is an exceptionally common disorder of premenopausal women. According to prospective studies, women with PCOS present abnormal glucose tolerance and diabetes mellitus in 31%-35% and 7.5%-10%, respectively. PCOS patients have a higher prevalence of cardiovascular risk factors such as hypertension, type 2 diabetes and dyslipidaemia. The rate of spontaneous abortions as well as the risk to develop gestational or type 2 diabetes is increased in PCOS. Therefore, PCOS is not only a reproductive problem but a complex endocrine disease with important health implications. The role of the glucose metabolism in PCOS, the health consequences and possible interventions are reviewed in this article.
In this study, we examined alterations in the apoptotic response of tamoxifen (TAM)-resistant breast cancer cells. We used an in vitro selection approach for TAM resistance by means of long-term culture of MCF-7 breast cancer cells with increasing concentrations of TAM. The apoptotic response to TAM was determined by means of ELISA measurement of apoptotic DNA-histone complexes in cytoplasm and by Annexin-V staining. MCF-7(LT) cells isolated after 5 months of long-term treatment with TAM exhibited a significantly reduced apoptotic response to this drug, even if administered in high concentrations up to 20 microM. This reduced apoptotic response was also observed after treatment with the topoisomerase II inhibitor etoposide, a pro-apoptotic antineoplastic drug. Microarray experiments comparing the transcriptome of MCF-7(LT) and wild-type cells revealed both the down-regulated expression of several genes coding for pro-apoptotic proteins and the up-regulation of genes coding for apoptosis inhibitors. Further experiments to determine expression changes of the receptor tyrosine kinases HER2 and epidermal growth factor receptor did not reveal any alterations in MCF-7(LT) if compared to wild-type cells. Our findings suggest that long-term treatment with TAM in vitro does not necessarily change the expression of receptor tyrosine kinases, but can modulate the expression of apoptotic key genes impairing the apoptotic response of MCF-7 breast cancer cells.
Gonadotropin-releasing hormone (GnRH) antagonists have been tested extensively in ovarian stimulation protocols for assisted reproductive techniques (ART). GnRH antagonists immediately and rapidly inhibit gonadotropin release by the anterior pituitary gland by competitive blockage of the GnRH receptor, preventing and interrupting luteinising hormone surges in controlled ovarian hyperstimulation for infertility treatment. A review of the available literature on GnRH antagonists for ART is presented, focusing on the pharmacological and clinical properties of the two compounds available on the market, cetrorelix and ganirelix. Both cetrorelix and ganirelix are well tolerated and effective drugs for controlled ovarian hyperstimulation and are of comparable value for infertility treatment. Cetrorelix is available as a 0.25mg preparation for daily injections and as a 3mg intermediate depot preparation. Ganirelix is available as a 0.25mg preparation for daily injections.Currently, two treatment protocols are used in clinical practice: the GnRH antagonist multiple-dose protocol and the GnRH antagonist single-dose protocol. Both protocols are effective and well tolerated. Cetrorelix and ganirelix have not yet been directly compared in a clinical trial; nor have the single-dose and the multiple-dose approaches been compared in a randomised, controlled trial. Data to compare these compounds in clinical terms can be extrapolated only from results of phase II dose-finding studies and phase III studies comparing GnRH agonist cycles with GnRH antagonists in single- and multiple-dose protocols. Therefore, all conclusions on clinical differences between cetrorelix and ganirelix should remain tentative, as they are based on a limited amount of available data.Randomised, controlled trials comparing cetrorelix and ganirelix are warranted to further evaluate benefits and drawbacks of individual GnRH antagonists. Furthermore, more data are needed to determine the efficacy and safety of cetrorelix and ganirelix in established treatment protocols in patients other than those included in clinical trials investigating new drugs, such as "poor responders", patients with polycystic ovaries, patients with a history of allergy or overweight patients.
Endometriosis is an important clinical problem in routine practice. Besides the problems of dysmenorrhea, dyspareunia and chronic abdominal pain, women with endometriosis are often infertile. We performed a systematic literature review on two issues: firstly, we clarified which medical treatment options have been investigated in prospective, randomized studies. Secondly, potential future treatments, still being preclinically investigated, were examined. A meta-analysis was not possible as the studies varied too much in their protocols and inclusion and exclusion criteria, as well as in the drugs and doses administered. Gonadotropin-releasing hormone (GnRH) agonists, progestins and oral contraceptives all appear to offer certain advantages for endometriosis patients. GnRH agonists appear to be the most effective but they are expensive and long-term treatment is not possible because of loss of bone mineral density. Estrogen add-back may offer some benefit for the clinical complaints of patients, but it may reduce the efficacy of GnRH agonists. Progestins have the best clinical profile and a good cost-effectiveness balance; however, most studies found that they were not as effective as GnRH agonists. Oral contraceptives are only effective during treatment and have a high relapse rate after therapy is completed. Future options may include the use of GnRH agonists, selective estrogen receptor modulators (SERMs) and anti-estrogens, as well as immunomodulators.
The efficiency of gene transfer is many times higher in viral than in liposomal transfection. One reason for this is an insufficient intracellular transport of the exogenous DNA into the nucleus in lipofection. Using liposomal transfection techniques for gene therapy is safer than viral approaches, so it would be of great importance to find solutions for their enhancement. We found a 4.51-fold increase in liposomal transfection of T-47D breast cancer cells by the addition of progesterone and a 2.81-fold increase by the addition of cholesterol. The transfection efficiency was measured as the activity of the delivered reporter gene luciferase. The addition of progesterone and cholesterol in combination led to a further enhancement of the transfection efficiency up to 13.72-fold. This additive effect could also be seen when we combined cholesterol with other steroids, but not by the combination of different steroids. All of these steroids alone had also the potential to increase liposomal transfection. Therefore we suggest that steroids and cholesterol enhance liposomal transfection by different mechanisms. Both substances have been shown to shift the exogenous DNA from the cytosol to the nucleus. Steroids normally act through intracellular steroid receptors, which migrate into the nucleus upon activation. The transfected DNA might be co-transported to the nucleus together with the migration of the activated steroid receptors. Even if cholesterol causes also an intracellular shift of DNA to the nucleus, its impact on the fluidity of cellular membranes or on the stability of lipoplexes in serum containing media could be mainly responsible for its effect. If the steroid enhanced liposomal transfection is dependent on the presence of steroid receptors, a specifically-enhanced gene delivery for a subgroup of gynecological tumours expressing high levels of steroid receptors could be possible.
INTRODUCTION: Granulomatous mastitis (GM) is a rare disease which predominantly occurs in premenopausal women shortly after their last childbirth. ETIOLOGY: Its etiology is unclear, however, the disease has been shown to be correlated with breast-feeding and the use of oral contraceptives. An autoimmune component has also been discussed. PRESENTATION: It presents with the clinical symptoms of galactorrhea, inflammation, breast mass, tumorous indurations and ulcerations of the skin. In mammography and sonography nodular opacities and hypoechoic nodules are found. Very often clinical and radiological findings mimic breast cancer. HISTOLOGICAL DIAGNOSIS: The diagnosis is made by histopathology. Histological features in GM include signs of a chronic granulomatous inflammation with giant cells, leucocytes, epitheloid cells and macrophages as well as abscesses. TREATMENT: Therapy of GM consists of complete surgical excision combined with oral steroid therapy, eventually in combination with anti-inflammatory drugs or colchicine. Use of methotrexate has also been successful. In case of formation of abscesses antibiotic therapy should be applied before steroid therapy. Immune-suppressive therapy should be performed until complete remission as rates of recurrence can be up to 50%.
With a prevalence of 5-10% the polycystic ovary syndrome (PCOS) is a common disorder of premenopausal women. According to prospective studies abnormal glucose tolerance and diabetes mellitus present in about 10.0% and 35.0% of adult women with PCOS, respectively. PCOS patients have a higher prevalence of cardiovascular risk factors such as hypertension and dyslipidaemia. The rate of spontaneous abortions as well as the risk of developing gestational diabetes is increased in PCOS. Therefore, PCOS is not only a reproductive problem, but a complex endocrine disease with important health implications. The role of glucose metabolism in PCOS, the health consequences and possible interventions are reviewed in this article.
BACKGROUND: Five women undergoing intracytoplasmatic sperm injection (ICSI) considered to be at high risk of developing an ovarian hyperstimulation syndrome (OHSS) from March to July 2002 underwent unilateral follicular aspiration. METHODS: When >/=15 follicles of 12-15 mm diameter in each ovary and a serum estrodial level >/=2500 pg/ml was present, follicular aspiration was performed unilaterally without hCG administration. Ovarian stimulation was continued for 1-3 days in four women before human chorionic gonadotrophin (hCG) was given. In one woman hCG injection was administered at the evening after unilateral follicular aspiration. The oocyte retrieval from the contralateral ovary was performed 36 h after hCG injection. By unilateral follicular aspiration two to six germinal vesicle (GV) oocytes could be retrieved. After in-vitro maturation of those oocytes ICSI was performed. RESULTS: In four women one to two oocytes were fertilized and cryopreserved. In one case only one triploid pronucleus (3PN) was observed. At the contralateral ovum-pick up after hCG injection a median of 10 could be retrieved. After transfer of a median of 3 embryos, no pregnancy was achieved. Four of five patients developed a severe OHSS and were hospitalized for a median of 3 days. CONCLUSION: Unilateral follicular aspiration and continuation of stimulation therefore can not be recommended for the prevention of OHSS.
OBJECTIVE: To evaluate the risk of testicular damage from testicular biopsies that are carried out for testicular sperm extraction (TESE) in infertile men. DESIGN: Prospective controlled clinical study. SETTING: Academic hospital. PATIENT(S): Forty infertile males with azoospermia. Examination of the clinical, endocrine, biochemical, and sonographic data in average after 18 months after TESE was performed. MAIN OUTCOME MEASURE(S): Measurements before and after TESE: hormone values, testicular size, morphologic characteristics, and power Doppler after scrotal sonography. RESULT(S): Comparison of preoperative and postoperative values of basal testosterone, FSH, LH, and estradiol levels did not reveal any differences. Twelve of 26 patients had subnormal testosterone values before TESE; 14 of 39 patients had subnormal levels afterward. Postoperative sonographic measurements showed no significant difference of the testicular volume as compared with the preoperative values. Results of power Doppler sonography revealed pathological conditions (n = 5) in patients with former iliacal or testicular operations. CONCLUSION(S): Endocrine testicular function and testicular size were not impaired after testicular biopsy when compared with preoperative data. However, patients with nonobstructive azoospermia seem to be at risk for androgen deficiency due to primary testicular failure after repeated testicular biopsies.
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According to the transplantation theory, endometriosis develops from endometrial fragments that are retrogradely menstruated into the peritoneal cavity. In order to develop into endometriotic lesions, they have to connect to the vascular system by angiogenesis, probably involving matrix metalloproteinases (MMP) as key enzymes in extracellular matrix remodelling. A model of endometriosis using the chorioallantoic membrane (CAM) of chick embryos was established. Eutopic endometrium from healthy women was transferred to the CAM and cultivated ectopically for up to 3 days. Before transplantation and after 24, 48 and 72 h of culture on the CAM, total RNA was extracted and reverse transcribed. Human MMP-1 (interstitial collagenase) and MMP-2 (gelatinase A) mRNA expression was assessed by competitive PCR. Results were normalized to the content of human glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA. In eutopic endometrium, 0.29 amol MMP-1 mRNA and 0.42 fmol MMP-2 mRNA per fmol GAPDH mRNA were found. Relative MMP-1 mRNA concentrations increased strongly after culture on the CAM, while MMP-2 mRNA levels were nearly unaltered. This differential regulation suggests different roles of these enzymes in the angiogenesis of ectopic endometrial fragments and during the development of endometriosis.
A crosstalk between cellular estrogen response and receptor tyrosine kinase signaling has been shown in a variety of estrogen receptor (ER)-positive cell lines. We intended to examine the presence of estrogenic growth factor effects in an ER alpha-negative breast cancer cell line. By means of reporter gene assays, we investigated the activation of estrogen response elements (EREs) by epidermal growth factor (EGF) in the estrogen-unresponsive cell line MDA-MB-231. Our results demonstrate the H-ras-dependent activation of EREs after EGF treatment in this estrogen-unresponsive cell line, an effect which was not observed in the ERalpha/beta-positive breast cancer cell line MCF-7. In MDA-MB-231 cells, the transcriptional activity of an ERE-containing promotor was enhanced dose dependently by all tested EGF concentrations. This effect could be blocked by co-treatment with the epidermal growth factor receptor (EGFR) inhibitors AG1478 and ZD1839, as well as by co-transfection with a vector coding for a dominant negative H-ras mutant, but not by co-treatment with the pure antiestrogen ICI182,780. Furthermore, expression of constitutively active H-ras was shown to be sufficient to activate EREs in MDA-MB-231 cells. Our results suggest alternative utilization of ERE-mediated gene regulation in an estradiol-unresponsive breast cancer cell line in response to an EGF stimulus. This mechanism was shown to be dependent on EGFR and H-ras activity, but independent of the presence of functional ERalpha.
BACKGROUND: Women with a single ovary form a group of special interest in assisted reproduction. The aim of this study was to compare the outcome of intracytoplasmic sperm injection cycles between women with one and two ovaries. To our knowledge, this is the first study reporting the outcome of intracytoplasmic sperm injection cycles with women with a single ovary. METHODS: Sixty-three intracytoplasmic sperm injection cycles in 24 women with a single ovary were compared with 191 intracytoplasmic sperm injection cycles in 109 women with both ovaries. All cycles were stimulated with triptorelin-long protocol. RESULTS: Statistically significant differences were found in the following parameters between women with a single ovary and women with two ovaries: total number of administrated gonadotropins (63.22 +/- 45.03 vs. 44.72 +/- 21.92), number of follicles (8.29 +/- 5.02 vs. 14.45 +/- 7.94), estradiol peak levels (1695.05 +/- 1177.34 vs. 2728.51 +/- 1852.67), number of retrieved metaphase II oocytes (6.95 +/- 3.78 vs. 11.72 +/- 6.11) and number of 2 PN oocytes (4.07 +/- 2.85 vs. 6.53 +/- 4.14). There were no differences in duration of stimulation, number of transferred embryos, and cumulative embryo score. In the group of women with a single ovary 14 pregnancies were achieved (22.2%), whereas 33 pregnancies were achieved in the group of women with two ovaries (17.28%). CONCLUSIONS: Women with a single ovary have a decreased response to external ovarian stimulation than women with both ovaries, but they present a higher, although not statistically significant, pregnancy rate.
GnRH analogues were introduced into clinical practice more than 20 years ago. The recent development of new GnRH antagonists (GnRHant) has revolutionized the treatment protocols of infertility. Ovarian stimulation has become easier, safer and more convenient for patients. This review presents data on the physiological background of GnRH and its analogues--agonists as well as antagonists--and highlights the different aspects of the clinical use of these substances. Two protocols, the single dose and multiple dose protocol are available and lead to comparable results. Data from prospective, randomized trials as well as meta-analyses suggest, that a more tailored, individualized approach concerning the day of administration of GnRHant may lead to more favorable results with regard to ovarian response, implantation and pregnancy rates. Possible negative effects of GnRHant, mainly based on in vitro models are discussed. The outcome of children born after GnRHant use has shown, that this medication is safe. On the whole, the use of GnRHant is advantageous as compared to the traditional way of ovarian stimulation, i.e., the GnRH agonist long protocol. However, especially the effectiveness of these compounds will have to be clarified in the near future by carefully designed prospective, randomized studies.
Replacing GnRH agonist cotreatment for the prevention of a premature rise in LH during ovarian stimulation for in vitro fertilization (IVF) by the late follicular phase administration of GnRH antagonist may render supplementation of the luteal phase redundant, because of the known rapid recovery of pituitary function after antagonist cessation. This randomized two-center study was performed to compare nonsupplemented luteal phase characteristics after three different strategies for inducing final oocyte maturation. Forty patients underwent ovarian stimulation using recombinant (r-)FSH (150 IU/d, fixed) combined with a GnRH antagonist (antide; 1 mg/d) during the late follicular phase. When at least one follicle above 18 mm was observed, patients were randomized to induce oocyte maturation by a single injection of either r-human (h)CG (250 microg) (n = 11), r-LH (1 mg) (n = 13), or GnRH agonist (triptorelin; 0.2 mg) (n = 15). Retrieved oocytes were fertilized by either IVF or intracytoplasmatic sperm injection, depending on sperm quality. Embryo transfer was performed 3-4 d after oocyte retrieval. No luteal support was provided. Serum concentrations of FSH, LH, estradiol (E(2)), progesterone (P), and hCG were assessed at fixed intervals during the follicular and luteal phase. The median duration of the luteal phase was 13, 10, and 9 d for the r-hCG, the r-LH, and the GnRH agonist group, respectively (P = 0.005). The median area under the curve per day (from 4 d post randomization until the onset of menses) for LH was 0.50, 2.34, and 1.07 for the r-hCG, the r-LH, and the GnRH agonist group, respectively (P = 0.001). The median area under the curve per day for P was 269 vs. 41 and 16 for the r-hCG, the r-LH, and the GnRH agonist group, respectively (P < 0.001). Low pregnancy rates (overall, 7.5%; range, 0-18% per started cycle) were observed in all groups. In conclusion, the nonsupplemented luteal phase was insufficient in all three groups. In the patients receiving r-hCG, the luteal phase was less disturbed, compared with both other groups, presumably because of prolonged clearance of hCG from the circulation and the resulting extended support of the corpus luteum. Despite high P and E(2) concentrations during the early luteal phase in all three groups, luteolysis started prematurely, presumably because of excessive negative steroid feedback resulting in suppressed pituitary LH release. Hence, support of corpus luteum function remains mandatory after ovarian stimulation for IVF with GnRH antagonist cotreatment.
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MATERIALS AND METHODS: This retrospective study was carried out in order to assess the value of inhibin B as a predictive factor for the assisted reproduction-outcome. Inhibin B on the day of HCG-administration (ovulation induction) was measured in 15 pregnant and 16 non-pregnant patients (defined as positive serum-HCG) and compared by single and multiple logistic regression analysis with classical predictive factors such as estrogen and oocyte number. Both groups were similar with respect to age and cause of infertility. RESULTS: While estrogen, FSH and LH at the HCG-day did not differ, inhibin B, the number of cumulus oocyte complexes and metaphase II -oocytes were statistically significantly different. In a single variable logistic model inhibin B, cumulus oocyte complexes and metaphase II oocytes showed significant correlation with pregnancy. When reassessed in a multiple variable logistic model only inhibin B maintained a considerable influence. Further inspection revealed, that the predictive inhibin B value at HCG-day <1200 pg/ml for failure of ART (assisted reproduction techniques) was 91%. Inhibin >1200 pg/ml showed 70% predictivity for pregnancy. CONCLUSION: In comparison to classical parameters inhibin B at HCG-day seems to be the better prognostic factor for the outcome of ART. Inhibin B <1200 pg/ml seems to be highly predictive for failure of ART.