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Biomedical subjects

D Krebs

Publications and source records attributed to D Krebs.

At least 181 records · Page 10Linked to original sources
PubMed1986

[Improved implantation rate following embryo transfer in an in vitro fertilization program].

In spite of the efforts made in in-vitro fertilization and embryo transfer in recent years, little progress has so far been made with regard to the pregnancy rate. While embryo transfer rates of over 80% are now being attained, the pregnancy rate achieved with extracorporal fertilization in the majority of study groups is well under 20%. Between 1981 and May 1986, 1088 laparoscopies were performed in our study group with the aim of follicle puncture and subsequent in-vitro fertilization and embryo transfer. A total of 171 pregnancies resulted from 832 embryo transfers. The pregnancy rate has been increased since 1981 to 21.2% at present (1986). Since April 1986 we have been using a modified embryo transfer procedure: in 25 patients embryo transfer has been accomplished under barbiturate anesthesia. Twelve of these patients have become pregnant, i.e., 48% of the embryo transfers. There are signs that this embryo transfer method will lead to a distinct improvement in the pregnancy rate. An attempt should be made to confirm these provisional results in a larger collective.

Alfentanil↗
PubMed1986

[Initial results of the cryopreservation of human oocytes].

As a part of an IVF project, "superfluous" ova were frozen, then thawed and fertilized under in-vitro conditions. Altogether 133 oocytes of varying quality, from 22 patients, were frozen. To date, 57 ova have been thawed and 47 oocytes have been found. The survival rate after thawing was 34%, the in-vitro fertilization rate 75%. Out of a total of seven embryo transfers performed there was one pregnancy following transfer of a six-cell embryo.

Cell Survival↗
PubMed1986

Successful in-vitro fertilization of frozen-thawed rabbit oocytes.

The objective of this study was to evaluate the capacity of frozen-thawed rabbit oocytes to be fertilized in vitro. After superovulation with FSH a total of 1040 oocytes was obtained by puncturing the follicles 6 or 9 h after the injection of LH or by flushing the oviducts 12 h after LH application. 1.5 M dimethylsulphoxide (DMSO) was used as cryoprotective agent and the oocytes were transferred into 0.25 ml French straws and cooled in a methanol bath to -30 degrees C and transferred to liquid nitrogen. After 1-14 days of storage the oocytes were thawed rapidly in a 15 degrees C water bath and DMSO was diluted in a stepwise manner. Subsequently the oocytes were cultured in Ham's F-10 + 10% fetal calf serum at 37 degrees C and 5% CO2 for 14, 7 and 4 h according to the time of oocyte collection. The survival rates of the oocytes based on morphological criteria were 5.4, 20.0 and 28.8%, respectively. For chromosomal analysis, morphologically intact frozen-thawed oocytes were fixed and stained using the technique described by Tarkowski. In 44 successful chromosomal preparations, 2 of 2, 10 of 19 and 22 of 23 preparations of oocytes collected 6, 9 and 12 h after LH application were in metaphase-II, respectively. Furthermore, the viability of the oocytes was also examined by using fluorescein diacetate. Out of 52 morphologically intact oocytes, 50 showed a positive intracellular fluorescence.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Influence of inorganic phosphate on the lipid synthesis of a phosphate-deregulated mutant of Streptomyces noursei.

Phosphate-dependent changes of the mycelial lipid composition were studied in the streptothricin-producing parental strain Streptomyces noursei JA 3890 b/2 and its mutant RG 2. In contrast to its ancestor, the mutant was capable of producing the antibiotic nourseothricin even when large quantities of inorganic phosphate were present in the medium. The apparent insensitivity of the secondary metabolism to phosphate inhibition corresponds to a decreased level of phospholipids in the presence of excessive inorganic phosphate and, during phosphate limitation, to a much higher production of the alkaline phosphatases. A model is discussed which proposed the control by a common genetic element of both the phospholipid and antibiotic production.

Alkaline Phosphatase↗
PubMed1985

The prognostic value of age for patients with common epithelial ovarian cancer.

For 230 patients with common epithelial ovarian cancer, the prognostic impact of age was examined. Statistical analysis was done using proportional hazard models, 3- and 5-year survival rates and median survival of stratified groups, and the Kaplan-Meier mean. Taking the age-adjusted mortality into account, the prognosis of the older patients was significantly worse. This effect depended primarily on early mortality (survival time less than 2 months). A comparative analysis was made of the prognostic factors age, grade, and stage, taking into account the correlation between factors. This analysis showed that, for our series, age was of lesser prognostic significance than grading, and both of these were of much less prognostic importance than staging.

Adult↗
PubMed1985

Effects of granulosa cells and gonadotrophins on maturation of rabbit oocytes in vitro.

Rabbit oocyte maturation was induced by i.v. injection of 100 mU/HCG. Six hours later the animals were sacrificed, their granulosa cells cultured 7-10 days and their oocytes incubated in different media for 5-6 h. The oocytes were then examined microscopically. The appearance of a polar body was taken as an indication that maturation had progressed. The results presented show that maturation of rabbit oocytes can be inhibited by granulosa cells in vitro (OMI = oocyte maturation inhibitor), the activity of OMI is influenced by gonadotrophins and cumulus cells have a facilitatory effect on OMI. The results give the first indication that OMI exists in rabbits and may contribute to the discussion about the existence of OMI in other species (e.g. the pig).

Animals↗
PubMed1985

[Grading of epithelial ovarian cancers].

UNLABELLED: Tissue slides of 230 epithelial ovarian cancers were examined by two different pathologic teams to determine the following details: histological pattern, grade of polymorphy, mitotic index, density of chromatin, presence of nuclei and macronuclei, lymphocytic infiltration, psammoma bodies, and necrosis. For statistical evaluations the data were presented together with stage, age and survival times in form of an information vector for each of the 230 patients and analysed using hazard-models (Cox 1972, Carter 1983) and contingency tables. RESULTS: The agreement between the 2 pathologic teams was good. There were many interrelated histological concomitants, such as polymorphy and chromatin density, and as nuclei and macronuclei. Necrosis was relatively independent. Significant effects on prognosis could be demonstrated for polymorphy, chromatin density, mitotic index, histologic pattern, (macro)nuclei. Polymorphy was the best histological prognostic indicator and, together with necrosis, produced the best prognostic grading system.

Adenocarcinoma↗
PubMed1985

[Effect of human follicular fluid on the maturity of rabbit ova by in vitro conditions].

The influence of human follicular fluid from mature and immature oocytes on the maturation of rabbit oocytes under in-vitro conditions was examined. The human follicular fluids were obtained in the course of laparoscopies for extracorporeal insemination and separated into the categories mature and immature ova. In cases of normal early embryonal development the follicular fluid was termed "follicular fluid of a mature ovum"; if the ova were immature or degenerated the fluid was termed "follicular fluid of an immature ovum". Rabbit oocytes were obtained 3 hours after administration of P-LH and immediately cultivated in 3 different culture media for 7 hours. Only 6 out of 50 rabbit oocytes cultivated in Brackett's Defined Medium with the addition of 20% follicular fluid from an immature human ovum for 7 hours reached prometaphase II to metaphase II. This corresponds to a rate of 12%; on the other hand, with the addition of follicular fluid from a mature ovum 18 out of 50 oocytes reached the same phase, i.e., a rate of 36%. This difference is statistically significant (p less than 0.01). Brackett's Defined Medium with no fluid added was used as a control. Only 5 out of 50 oocytes managed to reach prometaphase II to metaphase II. The rate in this case was 10%. In order to prove that the rabbit oocytes were in the chromatin consolidation phase, they were fixed immediately after being obtained (3 hours after P-LH administration) and stained in 5% Giemsa solution. All of the oocytes (31) were in the chromatin consolidation phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Polyspermy in in vitro fertilization of human oocytes: frequency and possible causes.

In an IVF program a total of 585 oocytes (180 patients) were examined for the presence of pronuclei 16 to 20 hours after the addition of spermatozoa. The overall fertilization rate was 71%, and in 58 (10%) of the fertilized oocytes, three or more pronuclei, indicating a failure of the block to polyspermy, could be observed. The frequency of polyspermy was related to the maturity of the oocyte, determined according to morphologic criteria. Immature oocytes showed a higher percentage of polyspermic fertilization (32%) compared to that of mature oocytes (6%). Preincubation of oocytes (for 0.5-1.5, 2-4, and 5-8 hours) prior to the addition of spermatozoa increased the fertilization rate (to 67%, 70%, and 83%, respectively). The polyspermy rate, however, was not significantly different between the various preincubation intervals (13%, 14%, and 19%, respectively). The polyspermy rate was affected by the number of spermatozoa used for in vitro fertilization. Insemination with 0.5-0.8, 1.0, or 1.5-2.0 X 10(6) spermatozoa/oocyte resulted in a polyspermy rate of 6%, 20%, and 32%, respectively. The appearance of polyspermic fertilization was not related to the age of the patient (which ranged from 20 to 45 years) nor to the method of ovarian stimulation (clomiphene, hMG, or clomiphene/hMG). Because of the high incidence of polyspermy under in vitro conditions it seems to be important to routinely examine the oocytes in the pronuclear stage. Reduction of the number of spermatozoa used for in vitro fertilization and the exact timing of insemination according to the maturity of the oocyte might reduce the occurrence of polyspermic fertilization.

Female↗
PubMed1985

[Initial results with PAC polychemotherapy in the treatment of advanced recurrent breast cancers].

11 patients with advanced, recurrent mamma cancer were treated by a PAC polychemotherapy. The therapy was well tolerated, the incidence of side effects was low. All patients responded to therapy (7 NED, 3 CR, 1 PR). 2 patients died, one commited suicide, the other died after having developed hepatitis. Of the remaining 9 patients 7 survive recurrence free; medium follow up 20 months. These data are in accordance with results obtained by Kolarić et al. [2] and Forastiere et al. [1] who showed platinum to be effective in the treatment of mamma cancer.

Adult↗
PubMed1984

Modification by genetic changes of the pleiotropic interference of butyrolactone-type autoregulators with differentiation of Streptomyces griseus.

Two series of aerial-mycelium-negative (Amy-), anthracycline-nonproducing (Ant-) mutants were obtained from ancestral Amy+Ant+ strains of S. griseus: a) derivatives represented by the met- strain 39 which could not differentiate although they were still producing both the butyrolactone-type autoregulator 1 and NADP-glycohydrolase, and b) mutants whose incapability to form spores and anthracycline pigments was apparently caused by the loss of autoregulator production. These latter mutants responded to the addition of 1 or the naturally occurring dihydro derivative 2 with complete or at least partial reconstitution of differentiation-associated functions. All of the b)-type mutant strains exhibited similar biochemical alterations in the presence of 1 or 2 regardless of the presence of additional genetic changes in the primary metabolism. Two mutants, however, displayed an altered pattern of secondary product formation. In submerged cultures the major biochemical changes observed in presence of 1 (or 2) were an increase of the lipid level in the mycelium, an alteration of the lipid composition, and a stimulation of neutral proteinase production. All of the blocked autoregulator-negative mutants were discernible from the ancestral strains and strain 39 by their lack of NADP-glycohydrolase production. This suggested the existance of a common genetic locus or a common pleiotropic regulator gene controling both gene functions. Present ideas concerning the role of butyrolactone-type autoregulator 1 as a pleiotropic effector molecule interacting with development of S. griseus are summarized in a hypothetical scheme.

4-Butyrolactone↗
PubMed1984

[Manifest chickenpox reinfection in pregnancy with low varicella antibody titer?].

The report concerns a case of an obvious varicella reinfection during pregnancy and the course of varicella-IgG and -IgM titers, respectively. By means of early diagnosis with an enzyme-linked immunosorbent assay (Elisa) and immediate application of a high - titered commercial varicella-zoster immunoglobuline, an infection of the foetus was probably prevented.

Adult↗
PubMed1984

[Platin-containing cytostatic combinations in the therapy of advanced gynecologic carcinomas].

95 patients with advanced and recurred gynecological carcinomas (57 ovarian carcinoma, 22 cervical carcinoma) were treated by a platinum (CDDP) based polychemotherapy platinum, adriamycine, cyclophosphamide (PAC); platinum, adriamycine, bleomycine (PAB), 22 out of 48 patients with low differentiated epithelial carcinoma of the ovary stage III and IV achieved a remission (13 CR; 9 PR). Today 6 of the CR-patients survive 23 months without recurrence; 7 had a medium survival of 17 months. Medium survival of PR-patients was 15 months. 6 NED-patients survive 22 months without recurrence and 2 NED-patients died after 19,5 months. The overall response rate (CR, PR, NED) was 63%. A retrospective comparison with 78 patients (low differentiated ovarian carcinoma stage III and IV) treated by a cyclophosphamide monotherapy shows an elevated 2-year survival rate of the PAC treated patients. The other patients suffered from carcinoma of the mamma, the tubes, the corpus uteri, the vagina, and the vulva. The therapeutic effect of CDDP based polychemotherapy cannot be judged because of the small number of cases; but the side effects at these patients were registered thoroughly. Side effects of totally 514 therapeutic cycles (460 mg CDDP per patient, 78 mg CDDP per cycle) are presented.

Aged↗
PubMed1984

[Performance of laparoscopic follicle puncture and oocyte recovery for in-vitro fertilization].

In-vitro fertilisation of human egg cells and subsequent embryonal transfer offers a possibility to sterile women with oviducts incapable of functioning, to become pregnant after all. This article describes the performance of laparoscopic follicular puncture and extraction of egg cells for in-vitro fertilisation. Laparoscopic follicle puncture as described here was performed from July 1982 to March 1983 on 130 patients at the Gynaecological and Obstetric Hospital in Lübeck. 585 follicles were punctured and 404 egg cells obtained, 210 of which met the criteria of a pre-ovulatory egg cell. Of the 210 pre-ovulatory egg cells, 177 could be fertilised. In 95 patients, embryo transfer was effected in the 2-cell to 8-cell stage. The fertilisation rate obtained was 84%, with an embryo transfer rate of 71%. Since this patient group also included andrological causes of sterility, this figure can be considered quite satisfactory, which is decisively due, among other things, to the puncture technique described here. Pregnancy was attained in 14 cases so far. It is certain that the pregnancy rate can be improved still further.

Female↗
PubMed1984

[Polyploidy occurring during in-vitro fertilization of human oocytes: frequency and possible causes].

In an IVF-program a total of 585 oocytes (180 patients) was examined for the presence of pronuclei 16 to 20 hours after the addition of spermatozoa. The fertilization rate was 71% and in 58 (10%) of the fertilized oocytes three or more pronuclei, indicating a failure of the block to polyspermy with polyspermic fertilization, could be observed. The frequency of polyspermy was related to the maturity of the oocyte, determined according to morphological criteria. Immature oocytes showed a higher percentage of polyspermic fertilization (32%) compared to mature oocytes (6%). Preincubation of oocytes (0-1.5, 2-4, 5-8 hours) prior to the addition of spermatozoa increased the fertilization rate (67%, 70%, 83%, respectively). The polyspermy rate seemed to increase (13%, 14%, 19%). The observed frequency, however, was not significantly different between the various preincubation intervals. The polyspermy rate was affected by the number of spermatozoa used for in-vitro fertilization. Insemination with 0.5-0.8, 1.0 or 1.5 X 10(6) spermatozoa/oocyte resulted in a polyspermy rate of 6%, 20%, 32%, respectively. The appearance of polyspermic fertilization was not related to the age of the patient (20 to 45 years) nor to the method of ovarian stimulation (Clomiphene, hMG, Clomiphene/hMG). Because of the high incidence of polyspermy under in-vitro conditions it seems to be important to examine the oocytes in the pronuclear stage on a routine basis. Reduction of the number of spermatozoa used for in-vitro fertilization and the exact timing of insemination according to the maturity of the oocyte might reduce the occurrence of polyspermic fertilization.

Adult↗
PubMed1984

[Postmenopausal bleeding following the application of an estrogen-containing hair lotion--concomitant endocrine changes].

Application of a commercially available hair lotion containing high concentrations of oestradiol led to uterine bleeding in a 76-year old patient. Histological examination of the endometrium showed typical proliferation. Oestradiol blood levels were in the normal range of the follicular or luteal phase, LH- and FSH-serum concentrations were suppressed. After discontinuing the application of the assay used (20 pg/ml) and gonadotrophins rose to normal postmenopausal levels. These findings prove that after local application of oestradiol on the scalp, percutaneous resorption of the steroid is significant and systemic oestrogen effects have to be taken into account.

Age Factors↗