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Dive into the research topics where Klaus Diedrich is active.

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Featured researches published by Klaus Diedrich.


International Journal of Cancer | 2000

Over‐expression of wild‐type Rad51 correlates with histological grading of invasive ductal breast cancer

Heiko Maacke; Sven Opitz; Kirsten Jost; Willem Hamdorf; Wilhelm Henning; Stefan Krüger; Alfred C. Feller; Antje Lopens; Klaus Diedrich; Eberhard Schwinger; Horst‐Werner Stürzbecher

Breast cancer is a major cause of cancer‐related death in women. BRCA1 tumour‐suppressor function is abolished in sporadic breast cancer by down‐regulation of the protein level. This down‐regulation inversely correlates with tumour grading. BRCA1 is part of a multiprotein complex, which also contains the recombination factor Rad51. Here we describe that in contrast to BRCA1, histological grading of sporadic invasive ductal breast cancer significantly correlates with over‐expression of wild‐type Rad51. These data suggest that in addition to the absence of the tumour‐suppressor protein BRCA1, over‐expression of wild‐type Rad51 also contributes to the pathogenesis of a significant percentage of sporadic breast cancers and that other mechanisms than mutations must be responsible for this altered expression. Int. J. Cancer 88:907–913, 2000.


Gynecologic and Obstetric Investigation | 2006

Is Endometriosis Associated with Systemic Subclinical Inflammation

Admir Agic; Hong Xu; Dominique Finas; Constanze Banz; Klaus Diedrich; Daniela Hornung

Endometriosis is a pelvic inflammatory process with altered function of immune-related cells and increased number of activated macrophages in the peritoneal environment that secrete various local products, such as growth factors and cytokines. The elevation of cytokines and other factors in the peritoneal fluid is accompanied by the elevation of similar factors, such as CRP, SAA, TNF-α, MCP-1, IL-6, IL-8 and CCR1, in the peripheral blood of patients with endometriosis. CD44+ and CD14+ monocytes are significantly increased, while CD3+ T lymphocytes and CD20+ B lymphocytes show modest, but significant decrease in peripheral blood of women with endometriosis. This indicates that endometriosis could be viewed as a local disease with systemic subclinical manifestations. This review provides an overview of data on the changes of various factors in peripheral blood and their potential use as diagnostic tools in patients with endometriosis.


Reproductive Biomedicine Online | 2006

GnRH-antagonists in ovarian stimulation for IVF in patients with poor response to gonadotrophins, polycystic ovary syndrome, and risk of ovarian hyperstimulation: a meta-analysis

G. Griesinger; Klaus Diedrich; Basil C. Tarlatzis; Efstratios M. Kolibianakis

This article is a systematic review of the literature on utilization of gonadotrophin-releasing hormone antagonists (GnRH-ant) for ovarian stimulation for IVF in special patient groups. Summarized by meta-analysis are the data from randomized controlled trials (RCT) in which GnRH-agonist (GnRH-a) and GnRH-ant were compared (eight RCT for poor response, four RCT for PCOS). Also reviewed are the data from two RCT and 13 retrospective or observational trials in which patients at risk of ovarian hyperstimulation syndrome (OHSS) were triggered with GnRH-agonist instead of HCG. For poor responders, no differences in clinical outcomes were found, except a significantly higher number of cumulus-oocyte complexes in GnRH-antagonist multiple dose protocol as compared to GnRH-agonist long protocol (P=0.05). For PCOS patients, no differences in outcomes were found, except a significantly shorter duration of stimulation, when GnRH-antagonist multiple dose protocol and GnRH-agonist long protocol are compared (P<0.01). However, sample sizes are still small and power to detect subtle differences is therefore limited. For OHSS risk patients triggered with GnRH-agonist, reports on the efficacy of this measure vary in the literature. GnRH-agonist triggering appears to be associated with a reduction in the incidence of mild and moderate OHSS. For prevention of severe OHSS, as yet, only very limited evidence is available.


Human Reproduction | 2012

Oocyte cryopreservation for age-related fertility loss

Wybo Dondorp; G. de Wert; Guido Pennings; Françoise Shenfield; Paul Devroey; Basil C. Tarlatzis; Pedro N. Barri; Klaus Diedrich

The recent introduction of oocyte vitrification has significantly advanced the outcome of oocyte cryopreservation, leading to clinical results comparable to those achieved in IVF using fresh oocytes, as reported by experienced centres. This has lead to new debate, both in the professional community and in society at large, about the acceptability of offering this technology to reproductively healthy women who want to cryopreserve their oocytes against the threat of time. Given the many demands calling for simultaneous realization in a relatively short period of their lives, many women who want to have children feel to be under considerable pressure. The option of oocyte cryopreservation may in fact give them more breathing space. In this document, it is concluded that the arguments against allowing this application of the technology are not convincing. The recommendations include the need for adequate information of women interested in oocyte cryopreservation, also in order to avoid raising false hopes. The message must remain that womens best chances of having a healthy child are through natural reproduction at a relative early age. Centres offering this service must have the necessary expertise to employ oocyte cryopreservation efficiently with the so far non-standardized protocols. As data about long-term safety is still lacking, centres also have a responsibility to contribute to the collection of these data.


Reproductive Biomedicine Online | 2007

Three years of routine vitrification of human zygotes: is it still fair to advocate slow-rate freezing?

S. Al-Hasani; Batuhan Özmen; Nikoleta Koutlaki; Beate Schoepper; Klaus Diedrich; Askan Schultze-Mosgau

Cryopreservation of human oocytes and embryos is a necessary tool in assisted reproduction treatment that leads to an increased cumulative outcome while decreasing costs. Vitrification is a cryopreservation technique that leads to a glass-like solidification, with rapid cooling of cells or tissues. Nowadays vitrification is claimed to be the future of cryopreservation of human embryos due to improved survival rates and clinical outcomes. This study was conducted at a university clinic to assess the safety and efficiency of vitrification of human zygotes as a routine procedure. A total of 849 pronuclear-stage (PN) zygotes were vitrified between March 2004 and July 2006. During this period, 103 cycles of cryopreserved embryo transfer were completed. In total, 339 PN zygotes were thawed resulting in an 89% survival rate (302 PN zygotes). The mean number of embryos per transfer was 2.2. The pregnancy rate obtained was three times higher (36.9%) than that obtained with the slow-rate freezing method (10.2%) used previously in the same centre. In conclusion, vitrification of human zygotes at the pronuclear stage seems to be a successful and reliable method with favourable outcomes and can be recommended as a routine technique for cryopreservation of human embryos.


European Journal of Obstetrics & Gynecology and Reproductive Biology | 1995

Preserved pituitary response under ovarian stimulation with HMG and GnRH antagonists (Cetrorelix) in women with tubal infertility

R. Felberbaum; Thomas Reissmann; W. Küpker; O. Bauer; Safaa Al Hasani; C. Diedrich; Klaus Diedrich

OBJECTIVE To examine the pituitary response in patients undergoing short-term application of the GnRH antagonist Cetrorelix in the mid-cycle phase for hypophysial suppression of premature LH surges within an IVF-program. DESIGN Twenty patients suffering from primary or secondary tubal infertility were stimulated with hMG from cycle day 2. From day 7 till ovulation induction Cetrorelix was administered in two different dose regimens (15 patients 3 mg s.c. daily; 5 patients 1 mg s.c. daily). Three hours before ovulation induction a GnRH test was performed using 25 micrograms of native GnRH and the pituitary response examined by measurement of the serum LH concentration after 30 min. RESULTS Premature LH surges could be avoided in the 3-mg group and in the 1-mg group, respectively. Due to this, none of the cycles had to be cancelled. Oestradiol profiles and ultrasound demonstrated a satisfactory follicular maturation. All patients showed pronounced suppression of the serum LH levels before ovulation induction. The mean increase of serum LH due to the performed GnRH test was 10 mIU/ml for the 3-mg group, while the average maximum in the 1-mg group was about 32.5 mIU/ml. CONCLUSIONS The pituitary response is preserved by the treatment with the GnRH antagonist Cetrorelix. The extent of suppression of the adenohypophysis, as expressed by the different reactions on GnRH test, can be modulated by the dosage administered. This should allow ovulation induction by GnRH or one of its agonists instead of hCG, which could be beneficial in patients at high risk of Ovarian Hyperstimulation Syndrome (OHSS) and those suffering from Polycystic Ovary Disease (PCOD).


Reproductive Sciences | 2007

Relative Expression of 1,25-Dihydroxyvitamin D3 Receptor, Vitamin D 1α-Hydroxylase, Vitamin D 24-Hydroxylase, and Vitamin D 25-Hydroxylase in Endometriosis and Gynecologic Cancers

Admir Agic; Hong Xu; C. Altgassen; Frank Noack; Monika Martina Wölfler; Klaus Diedrich; Michael Friedrich; Robert N. Taylor; Daniela Hornung

The authors demonstrate expression of the vitamin D receptor (VDR) and its hydroxylases in the endometrium and ovaries of women with and without endometriosis and endometrial or ovarian cancer. Immunohistochemistry showed strong staining of the VDR in endometriosis and endometrial cancer, with the most intense staining in epithelial cells. The VDR mRNA was significantly increased in patients with endometrial and ovarian cancer compared to the control group. There was a significantly higher 1α-hydroxylase expression in the endometrium of patients with endometriosis compared to healthy controls. The observed differences in VDR and 1α -hydroxylase mRNA levels were maintained at the protein level. The authors found no differences in 25-OH vitamin D levels between the serum of patients with endometriosis (25.7 ± 2.1 ng/mL, n = 46) and healthy controls (22.6 ± 2.0 ng/mL, n = 33, P = .31). They hypothesize that vitamin D might influence the local activity of immune cells and cytokines thought to play important pathogenic roles in the development and maintenance of endometriosis.


The Lancet | 2001

Selection pressure for the factor-V-Leiden mutation and embryo implantation

Wolfgang Göpel; Michael Ludwig; Ann K Junge; Thomas Kohlmann; Klaus Diedrich; Jens Möller

The factor-V-Leiden mutation is seen in high frequencies in white people, despite its contribution to second-trimester abortion, preterm birth, and deep-vein thrombosis. The reason for its high frequency is not known. We investigated 102 mother-child pairs who had had successful in-vitro fertilisation by intracytoplasmic sperm injection as a model for human implantation. In 90% (9 of 10) of mother-child pairs who carried factor-V-Leiden mutation, the first embryo transfer was successful, compared with 49% (45 of 92) in factor-V-Leiden negative pairs (p=0.018, Fishers exact test). Furthermore, the median number of unsuccessful transfers was lower in pairs who were positive for the mutation (0, range 0-2) than those who were negative (1, 0-8) (p=0.02, Mann Whitney U test) suggesting that improved implantation rate is an important genetic advantage of the factor-V-Leiden mutation.


Journal of Assisted Reproduction and Genetics | 1996

Hormone profiles under ovarian stimulation with human menopausal gonadotropin (hMG) and concomitant administration of the gonadotropin releasing hormone (GnRH)-antagonist Cetrorelix at different dosages

R. Felberbaum; T. Reissmann; W. Küpker; S. Al-Hasani; O. Bauer; T. Schill; C. Zoll; C. Diedrich; Klaus Diedrich

AbstractPurpose: The premature LH surge in ART programs seems to be avoided by daily administration of the GnRH-antagonist Cetrorelix during the midcycle phase in controlled ovarian hyperstimulation with hMG. The dosage necessary for sufficient suppression of the pituitary gland is not yet defined. Methods: To elucidate this question three daily dosages (3, 1, 0.5 mg) were administered and the hormone profiles obtained as well as the number of oocytes retrieved, the fertilization rate, and the consumption of HMG were compared. Results: No premature LH surge could be observed at any of the three dosages administered. Both gonadotropins were deeply suppressed. The fertilization rates of the oocytes obtained were 45.3% in the 3-mg group, 53.1% in the 1-mg group, and 67.7% in the 0.5-mg group. The average uses of hMG ampoules were 30 in the 3-mg group, 27 in the 1-mg group, and 26 in the 0.5-mg group. Conclusions: Cetrolix, 0.5 mg/day, administered during the midcycle phase of controlled ovarian hyperstimulation with hMG is enough to prevent completely the premature LH surge. Perhaps even lower dosages would be sufficient. Regarding fertilization rates and use of hMG, the lower dosage seems to be the most favorable.


Acta Obstetricia et Gynecologica Scandinavica | 2001

Evaluation of an optimal luteal phase support protocol in IVF

Michael Ludwig; Klaus Diedrich

Subject. Luteal phase support has been shown in the past to be an essential part of ovarian stimulation protocols, especially the long protocol. It could be shown that hCG is as effective as is progesterone for luteal phase support but hCG is accompanied by a higher rate of complications.

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Michael Friedrich

Massachusetts Institute of Technology

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