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K Diedrich

Publications and source records attributed to K Diedrich.

At least 19 recordsLinked to original sources
PubMed1999

Oocyte quality and treatment outcome in intracytoplasmic sperm injection cycles of polycystic ovarian syndrome patients.

Patients with polycystic ovarian syndrome (PCOS) have higher miscarriage rates. It is postulated that this is caused by a lower rate of mature oocytes, and a lower quality of embryos. Retrospectively we analysed 51 intracytoplasmic sperm injection (ICSI) cycles of 31 PCOS patients. These data were compared to age-matched controls (105 cycles) during the same period. All patients of both groups received gonadotrophin-releasing hormone (GnRH) agonists prior to gonadotrophin treatment. The rate of metaphase II oocytes (MII) was not different. However, the mean absolute number of normally fertilized oocytes was significantly higher in PCOS patients (5.00 versus 3.56, P < 0.01), due to a higher number of oocytes retrieved. More embryos were transferred by cycle in the PCOS group (2.69 versus 2.17, P < 0.05), with a higher cumulative embryo score. The overall and multiple pregnancy rate showed no differences and the clinical abortion rate was lower (21 versus 41.67%, P < 0.05) in the controls. Our findings demonstrate that negative factors unconnected to oocyte morphology must be present in PCOS patients. It is possible that only cytoplasmic, not nuclear, maturity is influenced in these patients.

Adult↗
PubMed1999

Comparison between chromatin condensation and morphology from testis biopsy extracted and ejaculated spermatozoa and their relationship to ICSI outcome.

A significant association between male subfertility, imperfect spermiation and abnormal nuclear condensation has been suggested. The DNA content of spermatozoa might be responsible for inducing alterations in sperm morphology. The final nuclear shape, which is species-specific, depends on chromatin condensation during spermatogenesis as well as a precise organization of DNA within the nucleus. Many reports have described the association between disturbances in sperm chromatin condensation, morphology and male infertility. Chromatin condensation is achieved by gradual substitution of lysinerich somatic histones by testis-specific histone and finally by protamine. In this study two groups of patients were compared: the first consisted of 63 patients who had undergone intracytoplasmic sperm injection (ICSI) with freshly ejaculated spermatozoa whereas the second included 47 patients assigned to ICSI with testes biopsy-extracted spermatozoa. In both groups chromatin condensation was assessed by aniline blue staining and morphology evaluated according to strict criteria. The condensed chromatin and morphology of spermatozoa were significantly (P < 0.0001) less in the second group compared to the first. However the fertilization, cleavage, implantation and pregnancy rates were almost the same in both investigated groups. There was no significant difference between the two groups with respect to ICSI outcome. The percentage of chromatin condensation (nuclear maturity) and morphologically-normal spermatozoa were significantly higher (P < 0.0001) in the ejaculated spermatozoa than in those from testis biopsy but the ICSI outcome (fertilization, cleavage, implantation and pregnancy rates) was the same. In view of these results the fertilization capability and the embryo quality obtained using testis biopsy extracted spermatozoa is not influenced by chromatin condensation and sperm morphology in testicular sperm extraction (TESE)-ICSI programmes. Therefore, it could be said that neither chromatin condensation nor morphology of testis extracted sperm could predict the fertilization, implantation and pregnancy rate in TESE-ICSI programmes.

Adult↗
PubMed1998

Dual action of androgen on calcium signaling and luteinizing hormone secretion in pituitary gonadotrophs.

An increase in serum androgen levels associated with a suppression of cyclic gonadotropin secretion is frequently observed in females with impaired ovarian function. Here, we addressed the hypotheses that androgens (testosterone and dihydrotestosterone) alter gonadotropin secretion by modulating agonist-induced Ca2+ signaling and/or Ca(2+)-controlled exocytosis. In mixed populations of pituitary cells from female rats, addition of testosterone reduced basal and agonist (GnRH)-induced gonadotropin secretion in a concentration- and time-dependent manner. The suppressive actions of this androgen on gonadotropin secretion were observed over the full GnRH concentration range. Reduction in agonist-induced gonadotropin secretion was also observed after addition of dihydrotestosterone, indicating that the inhibitory action of testosterone is not mediated by its conversion to estradiol. Both the extracellular Ca(2+)-independent spike phase and extracellular Ca(2+)-dependent sustained phase of GnRH-induced gonadotropin secretions were affected by testosterone. In part, the inhibitory action of testosterone was mediated by attenuation of GnRH-induced InsP3 production and InsP3-dependent Ca2+ mobilization. In addition, testosterone exhibited a Ca(2+)-independent action on gonadotropin secretion, as documented by attenuation of high potassium-induced secretion without an affect on depolarization-induced Ca2+ signals. These results suggest that androgen inhibition of gonadotropin secretion occurs at two distinct steps in the secretory pathway, one prior to and one after elevation in cytosolic Ca2+ concentration.

Androgens↗
PubMed1998

Serum concentration of vascular endothelial growth factor cannot predict the course of severe ovarian hyperstimulation syndrome.

Vascular endothelial growth factor (VEGF) is stated to be a possible promoter of the development and the severity of ovarian hyperstimulation syndrome (OHSS). The secretion of VEGF in granulosa cells seems to be human chorionic gonadotrophin (HCG) dependent. In this prospective study, the data of 10 patients suffering from severe OHSS with ascites and pleural effusions (haematocrit, fluid balance, serum HCG, serum oestradiol) were analysed. The serum VEGF concentration declined during the period of clinical improvement but provided no additional diagnostic information for the further course of OHSS. VEGF was neither an early marker of improvement, nor of worsening of the clinical picture of the OHSS. Serum oestradiol concentrations and serum VEGF concentrations showed a statistical correlation (r = 0.33, P < 0.001). There was no correlation between haematocrit and VEGF, nor between serum HCG and VEGF. To conclude, although VEGF may be involved in the pathogenesis of OHSS, it is not an important clinical marker for the course of an OHSS.

Ascites↗
PubMed1998

The effect of multiple cryopreservation procedures and blastomere biopsy on the in-vitro development of mouse embryos.

Preimplantation genetic diagnosis is currently used in clinical practice. In experienced hands the biopsy procedure alone does not affect the further in-vitro and in-vivo developmental potential of animal and human embryos. No data exist on the combination of cryopreservation of embryos at the pronuclear and/or 8-cell stage and/or biopsy at the 8-cell stage. Pronuclear stages of mouse F1 hybrids (C57Bl/jxCBA) were harvested and divided into several experimental groups. The developmental rates of zygotes, which were neither biopsied nor cryopreserved were used as data control. Others were only cryopreserved at the pronuclear stage (C-PN), or at the cleavage stage (C-CS), or both. Each of these groups was also combined with or without a biopsy. Only the hatched blastocyst rate (HBR), but not the 'simple' blastocyst rate, showed significant differences between groups. Neither C-PN (HBR = 60.42%), nor C-CS (63.16%), nor a combination of both (59.46%) had an impact on the hatched blastocyst rate when compared with that of the control group (67.46%). The biopsy procedure (55.93%) also proved not to be harmful for the embryos. The embryos, which were C-PN and C-CS, and subsequently biopsied, showed a significantly lower hatched blastocyst rate (39.62%) than that of the control, C-PN, C-CS, and C-PN/C-CS groups (P < 0.05). The combination of C-PN and cleavage-stage biopsy also lead to a lower hatched blastocyst rate (42.22%), compared with that of the control group (P < 0.05). It was concluded that couples must be advised that an effect on embryos which have undergone a combined cryopreservation and micromanipulation procedure cannot be ruled out. However, cryopreservation at the pronuclear or at the 8-cell stage alone, or in combination with a biopsy procedure, does not influence the further development of the embryo.

Animals↗
PubMed1998

Treatment of uterine fibroids with a slow-release formulation of the gonadotrophin releasing hormone antagonist Cetrorelix.

A depot preparation of the third-generation gonadotrophin-releasing hormone (GnRH) antagonist Cetrorelix (SB-75) was used for preoperative treatment in twenty premenopausal patients with symptomatic uterine fibroids who were to undergo surgery. In a prospective, open, randomized setting 60 mg of Cetrorelix pamoate salt was administered i.m. on cycle day 2. Patients were randomized for a second dose of 30 or 60 mg of Cetrorelix depot, which was administered according to the degree of oestradiol suppression (<50 pg/ml) on treatment day 21 or 28. Surgery was done after 6 or 8 weeks of treatment, depending on second dosage administration. Weekly transvaginal sonography (TVS) and magnetic resonance imaging (MRI) before and after treatment was performed, for fibroid volume assessment. Sixteen patients showed satisfactory suppression of gonadotrophins and sex steroid secretion, avoiding any initial flare-up effect. In these patients a mean shrinkage rate of largest fibroid volume of 33.5% at the end of treatment could be observed according to TVS, while the mean shrinkage rate obtained after 14 days of treatment was 31.3%. In good responders (shrinkage >20%) largest fibroid volume at day 14 was approximately 56.7% of basic assessment. Although MRI showed minor mean shrinkage rates of only 25.4% of the initial volume, these differences in comparison to TVS assessment were not statistically significant. The avoidance of any initial flare-up in gonadotrophin secretion may explain this extremely fast reduction in fibroid size. The advantages of GnRH antagonist treatment in this indication consist in the short treatment time with a fast restoration of the ovarian function. The rate of poor responders may be reduced by using an improved slow release preparation.

Adult↗
PubMed1998

Ovarian hyperstimulation syndrome (OHSS) in a spontaneous pregnancy with fetal and placental triploidy: information about the general pathophysiology of OHSS.

An ovarian hyperstimulation syndrome (OHSS) in spontaneous pregnancies is a very rare event. Hence, clinicians might make wrong decisions, such as laparotomy, because of suspicion of an ovarian carcinoma, or severe complications such as renal insufficiency may develop because the diagnosis and treatment of OHSS are delayed. Here we report a case of a woman in the 15th week of gestation, presenting with a partial hydatidiform mole and a triploidy of fetus and placenta, with an ongoing and severe OHSS even after legal induced abortion. A low vascular endothelium growth factor (VEGF) concentration (50 ng/ml) was measured when human chorionic gonadotrophin (HCG) exceeded 1000 IU/l and was followed by VEGF concentrations >900 ng/ml, when the OHSS developed. The literature on spontaneous pregnancies associated with OHSS is reviewed, and possible reasons for the clinical course presented in this study and the reviewed reports are discussed. The findings in this case contribute to our theory that VEGF is a causative factor of OHSS, but has no impact on the course of this disease.

Abortion, Induced↗
PubMed1998

Principles of mammalian fertilization.

The principles of mammalian fertilization are defined in relation to studies of the intracytoplasmic injection of spermatozoa into human oocytes (ICSI). Sections are included on the production of mature oocytes and mature spermatozoa, sperm-oocyte interaction, and formation of the pronucleate oocyte. Current concepts in gametogenesis are discussed, including spermiogenesis, oogenesis, the biology and penetration of the zona pellucida including capacitation and the acrosome reaction, gamete fusion, the block to polyspermy and growth of the pronucleus. A concluding section relates the normal events of fertilization to those occurring after ICSI and discusses various types of anomalies found in the oocyte after ICSI.

Animals↗
PubMed1998

Ultrastructure of gametes and intracytoplasmic sperm injection: the significance of sperm morphology.

The aim of this study was to determine characteristic malformations of sperm ultrastructure in patients with severe subfertility undergoing intracytoplasmic sperm injection (ICSI). Although light microscopy (LM) can reveal major abnormalities of the three parts of the spermatozoon (head, mid-piece and flagellum), the various cell organelles of the spermatozoon and their fine structure remain unevaluated by LM. Insight into the submicroscopic organization of the spermatozoon and its complex organellar system may contribute to a better understanding of the preconditions for success or failure of fertilization. An in-depth evaluation of semen quality by transmission electron microscopy (TEM) can improve the diagnosis of male subfertility and can give substantial information about the fertilizing competence of spermatozoa. Thus, in this study 56 ejaculated sperm samples from patients with severe male subfertility or previous failed attempts at in-vitro fertilization were assessed by LM and TEM prior to ICSI to evaluate the most important sperm defects causing extreme subfertility. LM analysis was performed according to World Health Organization criteria. It could be confirmed that severe head defects are mostly involved in long-term infertility and fertilizing failure in classical IVF treatments. The most frequent head defects are disorders of the nuclear membranes and the acrosomal cap and disorganization of the chromatin structure. These defects of sperm fine structure seem to be associated with dysfunctional sperm-oocyte recognition, binding and fusion with the oolemma. Chromatin alterations and signs of decondensation or karyolysis are frequently associated with a deterioration of the nuclear membranes and may be due to impaired spermiogenesis. However, our results and the success of ICSI proved that severe sperm defects have no predictive value and do not impair the fertilization process, and also that the maturity of spermatozoa does not play an important role. Fine structure analysis revealed the pleiomorphology and heterogeneity of human spermatozoa.

Female↗
PubMed1998

New approaches to ovarian stimulation.

Suppression of endogenous hormone production by gonadotrophin-releasing hormone (GnRH) agonists followed by controlled ovarian hyperstimulation (COH) with human gonadotrophins, especially the so-called 'long protocol' has developed from second-line into first-line therapy. Due to this attitude premature luteinization can be safely avoided, enhancing therapeutic efficacy. Recombinant preparations of human follicle stimulating hormone (FSH) have been proven to be effective within COH according to the long protocol. The high purity of these compounds may have clinical advantages. GnRH antagonists could be successfully introduced in COH protocols. Also, daily injections in the midcycle phase according to the 'Lübeck protocol', as single or only dual administrations around day 9 seem to abolish any premature LH rises. Due to their different pharmacological mode of action, based on a classic competitive receptor blockage GnRH antagonists avoid any flare-up period and allow ovarian stimulation to start within the spontaneous cycle. Pregnancy rates are comparable to those after long protocol stimulation. Combination of softer stimulation regimes like clomiphene citrate and low dose HMG with midcycle administration of GnRH antagonists may be the way to a cheap, safe and efficient ovarian stimulation. It seems to be high time for modest forms of ovarian stimulation, lowering burden and risk for our patients.

Female↗
PubMed1998

[Rhesus factor determination of the genome of stereomicroscopy selected amniocytes].

This study intended to develop a molecular biological method for the determination of the rhesus blood type through the genome of amniocytes. Using micropipettes amniocytes were isolated under a stereomicroscope from amniotic fluid samples. Single or several (> or = 10) amniocytes, respectively, were pipetted into 0.2 ml vials each, and were lysated at 65 degrees C for 15 min using an alkaline solution making the DNA accessible to polymerase chain reaction. Thereafter, the rhesus D gene as well as the CE gene were amplified with nested primers in two subsequent PCR. Finally, the amplification product was electrophoretically analyzed using agarose gel. When single aminocytes were analysed the amplification rate was 64% for the rhesus D gene, and 80% for the rhesus CE gene; "allele specific non amplification" was observed in 24% of cases. With 10 or more amniocytes per vial the amplification rate was 100%. This method permits to reliably predict the fetal rh-type at low costs within about 4 hours.

Amniocentesis↗
PubMed1997

A new indication for an intracytoplasmic sperm injection procedure outside the cases of severe male factor infertility.

OBJECTIVE: To show the success of intracytoplasmic sperm injection (ICSI) in cases of a low number of oocytes retrieved. STUDY DESIGN: 715 microinjection cycles, which were performed at our center, were analyzed retrospectively. RESULTS: Within the analyzed cycles, there were 50 cycles with less than four oocytes retrieved. Twelve, 18, and 20 cases were treated with one, two, and three oocytes, respectively. The rate of metaphase II oocytes injected and subsequently fertilized, and intact oocytes was similar in the three groups. The transfer rate was not significantly different from those cases with more than three oocytes (84% vs. 94%). Therefore, the rate of fertilization failure was not higher in the low-number group. The number of embryos transferred was statistically significantly lower in the group with one and two oocytes compared to the group with three oocytes (1, and 1.31 vs. 2.27; P < 0.01) and the group of all patients (2.63; P < 0.01), as well as between the group of less than four oocytes and all patients (1.63 vs. 2.63; P < 0.01). There was no statistically significant difference between the pregnancy rates of the three groups (36.4% vs. 20% vs. 22.2%), and also no difference was found between the group with less than four oocytes and the data of all patients (22% vs. 26.9%). CONCLUSION: In our opinion, these data show that ICSI guarantees a successful treatment even if only as many oocytes are present as embryos are planned to be transferred, i.e. three embryos. This has been accepted to be a new indication in our center. Therefore it should be possible to stimulate patients mildly, with e.g. clomiphene citrate, to avoid unnecessary hyperstimulation syndromes, and to lower the cost of hormonal superstimulation.

Adult↗
PubMed1997

Demonstration of fetal coronary blood flow by Doppler ultrasound in relation to arterial and venous flow velocity waveforms and perinatal outcome--the 'heart-sparing effect'.

This longitudinal observational study evaluates the stage at which coronary flow can be visualized by color-coded and pulsed wave Doppler sonography in fetuses with normal cardiac anatomy. Fetal biometry, echocardiography and Doppler examination of the umbilical and middle cerebral arteries, ductus venosus, inferior vena cava and umbilical vein were performed in 109 cases. Fetuses were divided into five groups based on the Doppler examination of the umbilical artery, birth weight and the ability to visualize coronary blood flow. Coronary blood flow was identified in six of 55 fetuses with normal growth who had normal Doppler studies and perinatal outcome. In these, visualization of coronary blood flow was possible after 31 weeks' gestation at a median gestational age of 37 weeks. Coronary blood flow was also visualized in ten of 54 fetuses with severe intrauterine growth retardation and highly pathological flow velocity waveforms in all vessels soon after a significant increase of venous indices in the inferior vena cava and ductus venosus. In these cases, coronary blood flow was identified at a significantly earlier gestational age (median 27 weeks). These fetuses had a poor perinatal outcome (average birth weight less than 3rd centile, mortality rate 50%, significantly lower umbilical artery blood pH and Apgar scores after 1 and 5 min). Intrauterine fetal death occurred in five fetuses after a median of 3.5 days following visualization of coronary blood flow. Median coronary peak blood flow velocities in the right coronary artery were higher in intrauterine growth-retarded than appropriate-for-gestational-age fetuses.

Blood Flow Velocity↗
PubMed1997

[Premature labor, determination of fetal lung maturity and medicamentous induction of lung maturation].

Preterm delivery continues to be one of the main causes of perinatal mortality and morbidity, comprising about 8% of all deliveries. The percentage of the most jeopardized preterm newborns weighing less than 1500 g is about 1, however, can be several fold higher in perinatal centers. Respiratory distress syndrome, intracranial hemorrhage, persistent fetal circulation as well as enterocolitis represent prominent complications. Avoiding preterm delivery in cases of preterm labor is attempted by application of magnesium sulfate, beta sympathomimetics or non-steroidal antiphlogistics. Is preterm delivery desirable, however not absolutely indicated, knowing the status of the fetal lung maturity may be helpful in the decision making process. This can nowadays best be achieved by determining the surfactant albumin-ratio by possibly repeatedly withdrawing amniotic fluid by amniocentesis. When inducing lung maturation, application of corticosteroids crossing the placenta is favoured. With impending preterm delivery this should always be given a try, independent from the time expected to be left until delivery- and also below the completed 27th week of pregnancy. Prenatal induction of lung maturation and postnatal application of surfactant are to be looked at as complementing therapeutic concepts in the immature neonate.

Adrenal Cortex Hormones↗
PubMed1997

Molecular cytogenetic diagnostics in sperm.

Among other factors contributing to male infertility, chromosomal anomalies are a frequent finding. Investigating 440 males with reduced sperm counts (< 20 x 10(6)/mL) we found 19 males with chromosome abnormalities (aneuploidies and translocations). This frequency of chromosomal aberrations (4.3%) is much higher than in the normal population. We were able to investigate sperm nuclei from seven out of these 19 men with molecular cytogenetic methods. There were two carriers of Robertsonian translocations, two had a constitutional reciprocal translocation and three were XYY males. In addition, one other man with a long history of infertility and a marker chromosome 15 was included. Using fluorescence in-situ hybridization, it was possible to investigate a great number of sperm nuclei in each case. Each translocation case showed a specific mode of chromosomal segregation; confirming the dependence on chromosomes involved and the individual segregation pattern in each patient. The well known elimination of the supernumerary Y-chromosome in XYY males during meiosis was confirmed in our study. Molecular cytogenetic investigations in sperm provide a more reliable risk estimate with respect to the possible injection of chromosomally unbalanced sperm during intracytoplasmatic sperm injection and can be valuable in genetic counselling.

Adult↗