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T Bauknecht

Publications and source records attributed to T Bauknecht.

89 records · Page 5Linked to original sources
PubMed1980

The effect of bromocriptine during early pregnancy in the rat: inhibition of implantation.

The increase in the number of the ovarian LH/hCG-receptors and of serum progesterone concentration during pregnancy in the rat is highly dependent on the presence of prolactin during the luteinization process. Blocking of the hypophyseal prolactin secretion by twice daily injections of 2 microgram/g body weight bromocriptine into rats from the first day of pregnancy onwards prevents the increase in ovarian hCG-binding and progesterone production. Similar results are obtained by application of bromocriptine during the first three days only or either at day 1, 3 or 5 after mating. In all bromocriptine treated rats implantation of blastocysts does not occur. The failure to implant is not due to a teratogenic effect of bromocriptine onto preimplantation embryos, but is probably the consequence of changes of the uterine mucosa caused by the lack of progesterone production in the luteal cells.

Animals↗
PubMed1979

The stilbestrol-adenosis-carcinoma syndrome.

For the development of the DES carcinoma syndrome, two different mechanisms may be assumed. 1. Indirect effect via teratogenesis: squamous cell carcinoma develops from adenosis vaginae with the assistance of cofactors (Fig. 6). Till now, a conversion of adenosis to clear cell carcinoma has never been observed (Hilgers, 1977). Adenosis is probably a precancerous lesion only for squamous cell carcinoma. 2. Transplacental terato-oncogenesis: clear cell carcinoma as a mesonephric carcinoma develops from persisting wolffian ducts with a latent period of 15 to 20 years. DES here acts only as a promoter by way of the transplacental teratogenic mechanism, thus as a terato-co-carcinogenic factor (Fig. 6).

Abnormalities, Drug-Induced↗
PubMed1978

Appearance of hCG-receptor after conversion of newborn ovarian cells into testicular structures by H-Y antigen in vitro.

In a previous report (Zenzes et al., 1978b) it was shown that dissociated ovarian cells of newborn rats in vitro, if exposed to H-Y antigen, reorganize into testicular structures. The current study was designed to see whether this morphological conversion also results in a functional conversion. The LH/hCG receptor was used as a parameter characteristic for the newborn testis, but not for the newborn ovary. In the converted ovary, the LH/hCG receptor becomes detectable a few hours after onset of the culture and remains continuously present afterward. The appearance of this receptor may be due to a hormone-like action of H-Y antigen.

Animals↗
PubMed1978

Effects of caffeine on sister chromatid exchange (SCE) after exposure to UV light or triaziquone studied with a fluorescence plus giemsa (FPG) technique.

Studies are reported that are designed to analyze the mechanism by which caffeine reduces the induction of SCE by UV light or alkylating agents. The substantial points are (1) caffeine does not inhibit SCE formation, and (2) the caffeine-mediated apparent decrease of SCE induction after UV or triaziquone exposure is due to a selective destruction of those metaphases otherwise exhibiting a high number of SCE. These findings and their relevance to the ascertainment of the SCE-forming process are discussed.

Animals↗
PubMed1977

Studies on steroid hormone receptors (5alpha-dihidrotesterone, estradiol, and dexamethasone) in cultured human fibroblasts and amniotic fluid cells.

Cultured human fibroblasts and amniotic fluid cells (AF cells) were examined for the presence of steroid hormone receptors. In both cell types, the androgen (DHT) or glucocorticoid (dexamethasone) receptor was detected, but not the estrogen receptor. Binding parameters in fibroblasts were: for androgen: KD = 3.7 X 10(-9) M, Bmax = 13 fmol/mg; for dexamethasone: KD = 4.5 X 10(-9) M, Bmax = 120 fmol/mg. Binding parameters in AF cells were: for androgen: KD = 4 X 10(-9) M, Bmax = 8 fmol/mg; for dexamethasone: KD = 1.9 X 10(-8) M, Bmax = 375 fmol/mg. Cultured cells derived from the gonads (of a patient with 17beta-ketosteroid reductase deficiency) seem to have more receptors than cells from extragenital body parts (Bmax = 21 fmol). With the aid of gel chromatography, the molecular weight of the androgen receptor was estimated to be 30-40 000D.

Amniotic Fluid↗
PubMed1977

Comparative in vivo mutagenicity testing by SCE and micronucleus induction in mouse bone marrow.

The treatment of mice with repeated injections of BUdR and FUdR allows for the demonstration of differentially stained metaphases from bone marrow after FPG (fluorescence plus Giemsa; Perry and Wolff, 1974) treatment. Thus, it is possible to determine the number of SCE's under in vivo conditions, which appears as a very promising system for mutagenicity testing. We studied the response of this system in comparison to the micronucleus test using six mutagenic agents: triaziquone, cyclophosphamide (CP), dimethylphenyltriazene (PDMT), methylnitronitrosoguandine (MNNG), dimethylnitrosamine (DMNA), and diethylnitrosamine (DENA). With the exception of MNNG and DENA, all these agents induce both, SCE and micronuclei, MNNG and and DENA being ineffective in both systems. The most potent SCE-inducing agent was triaziquone, followed by PDMT, CP, and DMNA. The quantitative comparison indicates that SCE are induced at 1/10-1/100 of the concentrations which are required for the detection of micronuclei.

Animals↗
PubMed1976

Trisomy 4p due to a paternal t(4p-;16p+) translocation.

A patient is described carrying a duplication 4p12 leads to pter due to a paternal translocation: 46,XY,t(4;16) (p12;p13). Involvement of chromosome No. 16 and the heterogeneity of the clinical picture in cases with dup (4p) are discussed.

Chromosome Aberrations↗
PubMedDate not supplied

Gemcitabine combined with cisplatin as first-line treatment in patients 60 years or older with epithelial ovarian cancer: a phase II study.

This phase II study evaluated the activity and toxicity of gemcitabine plus cisplatin as first-line treatment of patients with advanced ovarian cancer. Chemonaive patients >/=60-year-old with FIGO stage IIIC or IV epithelial ovarian carcinoma were enrolled. Patients received cisplatin 75 mg /m2 on day 1 and gemcitabine 1250 mg /m2 on day 1 (before cisplatin) and day 8 of a 21-day cycle. Of 44 female patients (median age, 70 years), 72.7% had stage IIIC disease and 67.4% had a Karnofsky performance status >/=80. Of the 37 response-evaluable patients (35 with measurable lesion[s] >/=2 cm), there were seven (18.9%) pathologic complete responses, two (5.4%) pathologic partial responses, two (5.4%) clinical complete responses, and 12 (32.4%) clinical partial responses, for an overall response rate of 62.2% (95% CI, 44.8%-77.5%), and a pathologic response rate of 24.3% (95% CI, 11.8%-41.2%). Median survival was 27.7 months (95% CI, 14.3-40.8 months). Grade 3/4 neutropenia and thrombocytopenia occurred in 59.5% and 30.2% of patients, respectively, with neutropenic fever in one patient. Grade 3 nausea /vomiting and alopecia occurred in 25.6% and 9.5% of patients, respectively. We conclude that gemcitabine plus cisplatin is active and feasible as first-line treatment of advanced epithelial ovarian cancer in patients >/=60 years. Further clinical trials adding gemcitabine to current standard, first-line treatment seem warranted in younger as well as older patients.

Age Factors↗
PubMedDate not supplied

Detection of T helper responses, but not of human papillomavirus-specific cytotoxic T lymphocyte responses, after peptide vaccination of patients with cervical carcinoma.

Human papillomavirus type 16 (HPV16)-encoded E7 oncoprotein is constitutively expressed in cervical carcinoma cells and is required for cellular transformation to be maintained. The E7 protein, therefore, forms an attractive target for T-cell-mediated immune intervention to prevent or treat HPV16+ tumors. The authors performed a peptide-based phase I/II vaccination trial to induce anti-tumor immune responses in patients with recurrent or residual cervical carcinoma. Fifteen HLA-A*0201+ patients with HPV16+ cervical carcinoma received vaccinations with synthetic peptides representing 2 HPV16 E7-encoded, HLA-A*0201-restricted cytotoxic T lymphocyte epitopes and a pan-HLA-DR-binding T-helper epitope, PADRE, in adjuvant. No signs of toxicity were observed. Two patients had stable disease for more than 1 year after vaccination, 3 patients died of the disease during or shortly after the vaccination period, and 10 patients maintained progressive cervical carcinoma. Specific immune responses directed against the vaccine components were analyzed in peripheral blood samples. No cytotoxic T lymphocyte responses against the HPV16 E7 peptides were detectable. After vaccination, strong PADRE helper peptide-specific proliferation was detected in 4 of 12 patients. In conclusion, peptide vaccination with 2 HPV16 E7 cytotoxic T lymphocyte epitopes and a universal T helper epitope is well tolerated by patients with advanced cervical carcinoma. Despite a reduction of in vitro cytolytic or proliferative recall responses to some, but not all, conventional antigens in this patient group, peptide-specific proliferative responses were induced in 4 patients. Based on the current study, it is now feasible to perform peptide vaccination in earlier stages of HPV16-induced cervical disease.

Adult↗
PubMedDate not supplied

Expression analysis of EGF-R and TGFa in human ovarian carcinomas.

Differences in the tumor biology of ovarian carcinomas probably influence operability and response to chemotherapy which are the most relevant prognostic factors. The phenotype of different malignant epithelial tumors including ovarian carcinomas is obviously associated with an activation of the EGF/TGFa signal pathway. When we analysed the expression of EGF-R and TGFa with biochemical, molecular-chemical and immunohistochemical methods in 29 different ovarian carcinomas, we found a correlation between the mRNA and protein levels of EGF-R as well as TGFa for tumors with low or high expressing rates. However, the concentration of measurable free EGF-Rs seems to depend on the amount of TGFa expression by the tumors. The EGF-R binding ligand TGFa is produced by the tumor cells; stromal cells are TGFa negative as shown by immunohistochemistry. By the use of an immunostaining index the TGFa protein concentration was measured semiquantitatively, classifying tumors according to their TGFa production rate. The comparison of TGFa mRNA amounts and staining index supports the hypothesis that TGFa is modified posttranslationally. EGF-R or TGFa expressing ovarian carcinomas had a high response rate to chemotherapy, whereas the EGF-R or TGFa negative tumors mostly exhibit a no change or progressive disease behaviour. These findings are the basis for our assumption that ovarian carcinomas with the basis for our assumption that ovarian carcinomas with an activated EGF-TGFa system are tumor biologically different compared to the EGF-R/TGFa negative tumors.

Antineoplastic Combined Chemotherapy Protocols↗
PubMedDate not supplied

The expression of EGF receptors, EGF-like factors and c-myc in ovarian and cervical carcinomas and their potential clinical significance.

The expression of the epidermal growth factor receptor (EGF-R) and the c-myc oncogene was investigated in different specimens of ovarian and cervical carcinomas. The EGF-Rs were analyzed by EGF binding assay, immunohistochemistry and Northern blotting. For analysis of c-myc expression, we used Northern blotting and immunohistochemistry. Furthermore, tissue concentrations of EGF-like factors (EGF-F) were measured in the same tumor and non-malignant specimens. The biochemical determination of EGF-R demonstrated that EGF specific binding sites were detected in 36% of ovarian (n = 140) and 81% of cervical carcinomas (n = 42). High amounts of EGF-R (greater than 10 fmol/mg specific binding) were found in 8% of the ovarian and 41% of the cervical carcinomas. Increased expression of EGF-R specific mRNA was detectable in 7/21 ovarian and in 5/7 cervical carcinomas. A positive correlation between the amounts of EGF-R mRNA, the EGF-R binding data and the staining index of EGF-R immunohistochemistry was found. The EGF-R immunohistochemistry demonstrates that only the tumor cells produce increased amounts of EGF-R, while the stromal cells are EGF-R negative. Low amounts of EGF-R specific mRNA were also detected in biochemically EGF-R negative tumors. The c-myc specific mRNA signal was found in all cases investigated. It is shown that the c-myc expression was increased in 10/21 ovarian and 5/7 cervical carcinomas. There was no positive correlation between the amounts of EGF-R and c-myc mRNAs. The product of myc, as detected by immunohistochemistry, is found in tumor as well as in stromal cells. The levels of EGF-F were measured in extracts of 63 ovarian and 12 cervical carcinomas and in 21 non-malignant tissues. About 30% of the tumor extracts contained higher EGF-F levels (4-15 ng/mg) than those found in the non-malignant specimens. Tumors with high EGF-F levels expressed high amounts of c-myc RNA. The EGF-R status (n = 111) and the EGF-F levels (n = 63) were related to the prognosis of survival for patients with ovarian carcinomas. EGF-R positive (EGF-R(+)) ovarian carcinomas had a significantly higher response rate to chemotherapy. The survival time of the EGF-R(+) group is reduced compared to the EGF-R negative (EGF-R(-)) group if only patients in remission are used to construct survival curves. Furthermore, a poor prognosis for survival was noticed for ovarian carcinoma patients with high EGF-F levels.

Biomarkers, Tumor↗
PubMedDate not supplied

UGP--a tumor marker of gynecologic and breast malignancies? Specificity and sensitivity in pretherapeutic patients and the influence of hormonal substitution on the expression of UGP.

Urinary gonadotropin peptide (UGP) is a 10,300 Dalton peptide which is present in the urine of pregnant women, those with trophoblast disease and those with, certain nontrophoblastic malignancies. We examined the efficiency of UGP measurement at differentiating benign from malignant gynecologic and breast diseases. UGP was measured in 1355 spot urine samples from 841 patients (343 samples from 323 healthy women and women with benign gynecologic and breast diseases, 1012 samples from 518 women with gynecologic malignant diseases or breast cancer). Using a cutoff of > 3 fmol UGP/mg urinary creatinine the specificity was 97%. The sensitivity of UGP was calculated from pretherapeutically collected samples (n = 210). The sensitivity of the test for all malignancies was 26% (ovarian malignancy (n = 27) 52%, endometrial cancer (n = 25) 32%, cervical cancer (n = 49) 29%, breast cancer (n = 72) 19%, vulvar cancer and vaginal cancer (n = 12) 17% and for carcinoma in situ of the breast or the cervix (n = 20) 0%). We also found significantly higher UGP values in postmenopausal women than in premenopausal women. Hormonal substitution significantly lowered the UGP values.

Biomarkers, Tumor↗