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C Schneeberger

Publications and source records attributed to C Schneeberger.

At least 37 records · Page 2Linked to original sources
PubMed1999

Endocrinological disorders. Focusing on melatonin's interactions.

BACKGROUND: The interaction of melatonin to sterility and anovulation as well as related hormonal disorders has not been sufficiently examined yet. We set out to investigate the interaction between melatonin and hyperprolactinemia, hyperandrogenemia, hypothyreosis and obesity in premenopausal females. METHODS: We evaluated the overnight urinary excretion of 6-sulfatoxymelatonin (6-SMT) in a group of 155 women using a radioimmunoassay. RESULTS: Melatonin levels in patients with hyperprolactinemia and hyperandrogenemia with normal body mass index are significantly higher compared to matched controls. Obese females without hormonal disorders showed statistically lower 6-sulfatoxymelatonin levels and in hypothyreotic females we found no difference in 6-sulfatoxymelatonin levels compared to controls. CONCLUSION: Melatonin plays an important role in patients with hormonal disorders such as hyperprolactinemia and hyperandrogenemia. Melatonin should be prescribed restrictively in all sterile patients. In patients with untreated hypothyreosis or obesity, melatonin seems to play a minor part; in those with hyperprolactinemia and hyperandrogenemia additionally to standard sterility treatment light therapy may improve the outcome.

Adolescent↗
PubMed1999

Messenger RNA determination of estrogen receptor, progesterone receptor, pS2, and plasminogen activator inhibitor-1 by competitive reverse transcription-polymerase chain reaction in human breast cancer.

Estrogen receptor (ER), progesterone receptor (PR), the estrogen-inducible protein pS2, and plasminogen activator inhibitor-1 (PAI-1) are important prognostic factors in primary breast cancer. The protein concentrations of these factors in breast tumors have been well documented. However, few data about the mRNA expression of ER, PR, pS2, and PAI-1 in breast cancer are available, which is mostly due to the limitations of conventional techniques for mRNA analysis. We have described a competitive reverse transcription-PCR system for the simultaneous quantification of ER, PR, pS2, and PAI-1 mRNA in tumor samples. Here, we evaluated 100 tumor biopsies from breast cancer patients for the mRNA expression of ER, PR, pS2, and PAI-1. The results were analyzed for correlations with protein status and with clinical data. Significant correlations between mRNA expression levels and protein concentrations of all tested markers were found. In only a few cases was there an obvious discordance between the measurable amounts of mRNA and protein, especially for ER and PR. In addition, ER, PR, and pS2 mRNA levels correlated significantly with each other. No correlation between PAI-1 mRNA amount and the expression of the other markers was found. With respect to clinical data, ER and PR mRNA levels were found to be inversely correlated to tumor size and histological grade but not to the lymph node status. pS2 and PAI-1 mRNA expression were not correlated with tumor size, grade, or lymph node involvement. In conclusion, competitive reverse transcription-PCR may be used as an alternative for the study of prognostic factors in human breast cancer and other malignancies. However, before mRNA expression is measured for diagnostics, a presumed concordance of mRNA and protein expression must be evaluated very carefully for every gene.

Adult↗
PubMed1998

M3/M21 serum levels in women with adnexal masses and inflammatory diseases.

The aim of the present study was to evaluate the clinical usefulness of the cytokeratin tumor marker M3/M21 as a screening marker for ovarian cancer, as a predictive marker in patients with adnexal masses and as a prognostic factor in women with ovarian cancer. To determine the specificity of the M3/M21 test, we investigated M3/M21 serum levels in several benign conditions. This retrospective study comprises 37 patients with ovarian cancer FIGO stages Ia to III. Sera of patients with benign cysts, endometriosis, pelvic inflammatory disease, inflammatory bowel disease and liver cirrhosis were evaluated in 90, 10, 38, 10 and 20 cases, respectively. With a sensitivity of 57% and a specificity of 95%, M3/M21 is not suitable as a screening marker for ovarian cancer. Although M3/M21 is able to discriminate between ovarian cancer and benign adnexal tumors (univariate logistic regression, p = 0.0003), M3/M21 does not provide information additional to CA 125. M3/M21 serum levels are elevated in several benign conditions such as liver cirrhosis and inflammatory bowel disease. In ovarian cancer patients, elevated M3/M21 serum levels prior to therapy were associated with poor overall and disease-free survival (log-rank test, p = 0.03; log-rank test, p = 0.01, respectively). M3/M21, while obviously not suitable for screening or differential diagnosis of adnexal masses, could be useful as an additional prognostic factor in ovarian cancer patients.

Adenocarcinoma↗
PubMed1998

Oxytocin and vasopressin 1a receptor gene expression in the cycling or pregnant human uterus.

OBJECTIVE: Our purpose was to compare concentrations of messenger ribonucleic acid specific for the oxytocin receptor and for the vasopressin 1a receptor in myometrial and endometrial tissues of pregnant and nonpregnant women. STUDY DESIGN: Tissues from pregnant uteri were obtained from 95 women who were undergoing cesarean delivery between 26 and 42 weeks' gestation. Tissues from nonpregnant uteri were obtained from 7 cycling women who were undergoing hysterectomy. The competitive reverse-transcription polymerase chain reaction method was used to determine messenger ribonucleic acid concentrations. RESULTS: A significant increase in oxytocin receptor messenger ribonucleic acid was found during the first half of pregnancy. Oxytocin receptor messenger ribonucleic acid concentrations were lower in tissues with spontaneous contractions than in quiescent tissues and were decreased in patients with advanced labor. Vasopressin 1a receptor messenger ribonucleic acid concentrations were high in tissues from both cycling and pregnant uteri but remained unchanged throughout gestation. CONCLUSION: The increase in oxytocin receptor protein concentrations seen in pregnancy is only partially controlled by messenger ribonucleic acid abundance. High concentrations of vasopressin 1a receptor messenger ribonucleic acid confirm the biologically active role of this receptor in both the cycling and the pregnant uterus.

Endometrium↗
PubMed1998

Expression of endothelial (type III) nitric oxide synthase in cytotrophoblastic cell lines: regulation by hypoxia and inflammatory cytokines.

Expression of endothelial nitric oxide synthase (eNOS) has been localized to the villous syncytiotrophoblasts suggesting that NO release from these cells could prevent platelet adhesion and aggregation in the intervillous space. Hypoxia- or inflammation-dependent changes in the release of this vasoactive substance may result in thrombus formation and altered vascular resistance which occur in the placental bed of pre-eclamptic patients. To evaluate the influence of low-oxygen tension and inflammation on eNOS production in the trophoblast steady-state eNOS mRNA and protein levels were investigated in cytotrophoblastic BeWo and Jeg-3 cells cultured at 3.5 per cent oxygen and/or in the presence of the pro-inflammatory cytokines IL-1 and TNF-alpha. By RT-PCR and immunocytochemistry we demonstrate that BeWo cells produce eNOS mRNA and protein while eNOS polypeptide was undetectable in JEG-3 cells. In BeWo cells addition of both cytokines decreases eNOS mRNA and protein abundancies within 24 h of incubation while each substance alone had no effect. Compared to controls, the amount of eNOS transcripts was found to be elevated at low-oxygen tension, however, cNOS protein was downregulated after 24 h in the hypoxic environment, as shown by immunocytochemistry and Western blot analysis. Forskolin and methotrexate, which induce biochemical differentiation/ growth arrest in choriocarcinoma cells, stimulate eNOS mRNA and protein synthesis, but cannot overcome the decline of eNOS polypeptide levels during hypoxic incubation. It is speculated that acute hypoxia and inflammation impair eNOS/NO production of the trophoblast in vivo, which might contribute to pathological conditions of gestational diseases.

Adult↗
PubMed1998

Induction of inducible nitric oxide synthase expression in human secretory endometrium.

The endometrial secretory phase is characterized by stromal oedema, a premenstrual increase in stromal macrophages and an increased cytokine production as menstruation approaches. Nitric oxide (NO) is a mediator of vasodilatation and cytotoxicity which is synthesized from L-arginine by NO synthases (NOS). These enzymes are either constitutively expressed or induced by lipopolysaccharides and/or cytokines. The presence and function of the inducible isoform of NOS (iNOS) in normal human endometrium has not been fully elucidated until recently. Frozen tissue sections taken from 22 women who underwent hysterectomy and adnexectomy for benign disease were immunostained with antibodies raised against the different NOS isoforms to investigate the presence of NOS in human endometrium. iNOS stained positive in the glandular epithelial cells of the secretory endometrium. Staining was either weak or absent in the proliferative and inactive endometrium, as well as in the oviduct and the glandular epithelium of the endocervix. The stroma remained uniformly negative. Immunoreactivity for endothelial constitutive NOS (eNOS) was confined exclusively to endothelial cells. Furthermore, epithelial cells from endometrium, oviduct and endocervix and all endothelial cells showed positive staining for reduced nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase, which is a histochemical marker for NOS activity. Reverse transcriptase polymerase chain reaction (RT-PCR) was performed in order to assess the presence of NOS mRNA. Abundant expression of iNOS mRNA was detected in the secretory phase endometrium only. The strong expression of inducible NO synthase in human secretory phase endometrium suggests that the increased production of NO, probably induced by cytokines, may be relevant to the process of menstruation.

Base Sequence↗
PubMed1998

[The role of nitric oxide in reproduction].

Nitrix oxide (NO) is a highly reactive and short-lived radical (half-life time: 10-12 s), which is derived from L-arginine by the NO synthases (NOS) in several organ systems. The release of NO by endothelial cells leads to rapid relaxation of vascular smooth muscle cells, whereas release by several neuronal cells causes neurotransmission. When NOS is actively induced in immune cells or certain epithelia it causes cytotoxicity and/or apoptosis of these cells. In the reproductive organs NO is now considered to be an important trigger molecule for several physiological mechanisms. Follicular synthesized NO is involved in rupture of the follicle during ovulation. Moreover, NO participates in the acrosome reaction of spermatozoa during capacitation. Apoptosis and collagenolysis of the functional endometrium may be involved in endometrial shedding during menstruation. Since NO induces both apoptosis and collagenolysis, the newly discovered production of NO in late secretory endometrium could act as a key mechanism in the process of menstrual disintegration of the endometrium. Additionally, NO is necessary to support and maintain the decidualization process and plays a pivotal role in implantation.

Female↗
PubMed1998

Nitric oxide synthases in Kaposi's sarcoma are expressed predominantly by vessels and tissue macrophages.

Kaposi's sarcoma (KS) is a tumor of presumed vascular origin frequently found in patients with AIDS. Recent data suggest that the development of KS is linked with the presence of a newly recognized herpesvirus, human herpesvirus type 8. Nitric oxide (NO), a messenger molecule with vasoactive, antitumor, and antimicrobial effects, is produced by three isoforms of nitric oxide synthases (NOS). In the present report, we investigated the expression of NOS isoforms in KS. By NADPH-diaphorase histochemistry, NOS activity was detectable in endothelia and CD45+ cells within KS lesions. Reactivity for endothelial NOS (eNOS) was found in blood vessel endothelia; however, eNOS reactivity was negative in KS spindle cells in 12 of 17 tumors, and moderately positive in the other 5 lesions. In contrast to KS, tumor cells in three hemangiomas and one angiosarcoma were strongly positive for eNOS. Inducible NOS (iNOS) was absent from KS tumor cells but was found regularly in CD45+, HLA-DR+ cells within the lesions. In five KS-derived spindle cell cultures, neither eNOS nor iNOS proteins were detectable. The sporadic expression of eNOS by KS spindle cells in vivo and the absence of eNOS protein from KS spindle cells in tissue cultures argue against the possibility that the cells are derived from blood vessel endothelia. The consistent expression of iNOS by CD45+, HLA-DR+ cells within KS lesions strongly suggests that leukocyte-derived NO participates in the pathology of this tumor.

Endothelium, Vascular↗
PubMed1998

A differential PCR system for the determination of CCND1 (cyclin D1) gene amplification in head and neck squamous cell carcinomas.

The gene for Cyclin D1 (CCND1) lies within chromosomal region 11q13 and codes for a cell cycle regulator essential for G1 phase progression. This G1-cyclin is a putative protooncogene whose clonal rearrangement and/or amplification and mRNA overexpression occurs in several types of human neoplasias, including head and neck squamous cell carcinomas. Data from the literature suggest that amplification and overexpression of the CCND1 gene could lead to destabilisation of cell cycle control mechanisms and uncontrolled cell proliferation. We developed a differential PCR system for the determination of CCND1 gene amplification in head and neck squamous cell carcinomas. A 115 bp CCND1 fragment and a 150 bp gamma-interferon fragment are amplified simultaneously in the same reaction tube under optimized conditions. Statistical analysis of amplification data obtained by differential PCR revealed excellent correlation with amplification data obtained by conventional Southern hybridization.

Blotting, Southern↗
PubMed1997

[6-sulfatoxymelatonin in women with secondary amenorrhea].

We evaluated the overnight urinary excretion of 6-sulfatoxymelatonin in a group of 347 women (range: 18-69 years). 26 women (range 20-29 years) with normogonadotrophic, hypoestrogenemic amenorrhoea (WHO II) were selected and compared with a group of 26 women menstruating normally (range: 19-30 years) with respect to urinary 6-sulfatoxymelatonin excretion, serum 17 beta-estradiol levels and response to the thyroid releasing hormone (TRH) test. Patients with hyperprolactinemia, hyperandrogenemia, thyroid dysfunction and weight problems were excluded. 6-sulfatoxymelatonin was found to be significantly higher in the amenorrhoeic women than in the controls (p < 0.000001). In the amenorrhoeic patients a statistically significant inverse correlation was found between serum 17 beta-estradiol levels and urinary 6-sulfatoxymelatonin excretion. A positive correlation was obtained between the thyroid stimulation hormone (TSH) value measured at 20 minutes after stimulation and 6-sulfatoxymelatonin excretion. Further clinical research in this field is required to evaluate its clinical impact, especially in patients with secondary amenorrhea.

Adolescent↗
PubMed1997

Quantitative determination of gene expression by competitive reverse transcription-polymerase chain reaction in degraded RNA samples.

Quantitative competitive reverse transcription-polymerase chain reaction has become a powerful tool for determining the amount of mRNA in cultured cells as well as in tissue. To ensure the reliability of the analysis, RNA with high purity and integrity is needed. However, when analyzing RNA samples from tumor biopsies, RNA degradation is often an inevitable problem. This causes differences in sample quality and furthermore adversely affects the quantification of gene expression. Here, we demonstrate that in partially degraded RNA samples different mRNAs are degraded to the same extent. Normalizing the expression level of a specific gene to that of a constitutively expressed gene in the same sample allows the relative quantification of this specific gene. Thus, the comparison of gene expression in RNA samples with varying integrity is possible.

Gene Expression↗
PubMed1997

Detection of p53 point mutations in primary human vulvar cancer by PCR and temperature gradient gel electrophoresis.

Clinical and experimental evidence is consistent with a key role of point mutations of the p53 tumor suppressor gene in the etiology of squamous cell carcinoma. To determine the relation of tumor behavior and patient survival in vulvar cancer in regard to p53 status, we retrospectively analyzed 38 paraffin-embedded specimens of primary vulvar cancer for genetic alterations of exons 5-8 of the p53 gene. For detection of p53 point mutations we used in vitro amplification by polymerase chain reaction (PCR) and temperature gradient gel electrophoresis (TGGE) and, as a detection method, direct sequencing for mutation verification. p53 point mutations were detected in 12/38 tumor specimens. Patients bearing p53 point mutations showed a significantly shorter relapse-free (log-rank test, P = 0.002) and overall survival time (log-rank test, P = 0.0006). We conclude that PCR-TGGE is an appropriate method for detection of p53 point mutations in paraffin-embedded material. We show that loss of wild-type p53 is an adverse prognostic factor in patients suffering from vulvar cancer.

Adult↗
PubMed1996

Simultaneous expression of nitric oxide synthase and estrogen receptor in human breast cancer cell lines.

For various human tumor cell lines (neuroblastoma, cervix carcinoma) the presence of constitutive nitric oxide synthase (cNOS) has been documented. Here, for the first time, we report about cNOS expression in 10 of 16 human breast cancer cell lines. cNOS expression correlates strongly with expression of estrogen receptor (ER). Competitive reverse transcription-polymerase chain reaction (cRT-PCR) was used to detect cNOS and ER mRNA expression. Our findings suggest that estradiol could stimulate constitutive NO release in breast tissue, where it acts as a free radical.

Breast Neoplasms↗
PubMed1996

Quantification of uPA receptor expression in human breast cancer cell lines by cRT-PCR.

The conversion of plasminogen to active plasmin is thought to be a crucial step in the process of extracellular matrix degradation associated with metastatic spread. Activation of plasminogen is initiated by urokinase plasminogen activator (uPA). The binding of uPA to the uPA cell surface receptor (uPA-R) accelerates plasmin generation from plasminogen and localizes uPA activity to the cell surface. We investigated the mRNA-expression of uPA-R in 19 different human breast cancer cell lines. In a competitive reverse transcription polymerase chain reaction (cRT-PCR) we simultaneously co-amplified two different RNA templates bearing the same primer recognition sequences, the cell line RNA and a known amount of an in vitro synthesized uPA-R-RNA internal standard. We analyzed the two PCR products differing 50 bp in size by agarose gel electrophoresis and calculated the initial uPA-R-RNA template concentration from the relative intensities of the bands quantified by video densitometry. We grouped the investigated cell lines according to their in vitro invasiveness according to literature. Cell lines with a high potential of invasiveness showed a higher expression of uPA-R compared to those with a low potential of invasiveness (Student's t-test, p 0.04). In addition to that we compared the uPA-R mRNA levels with uPA-R, uPA, and PAI-1 protein levels in culture supernatants and cell lysates. The obtained results in breast cancer cell lines with different invasiveness and in benign epithelial cell lines revealed the complex cooperation of the urokinase type proteolytic pathway. uPA, uPA-R, and PAI-1 are to be considered as a diagnostic tool rather than assaying a particular molecule alone. Our findings support the hypothesis that the urokinase proteolytic pathway plays a central role in the acquisition of an invasive phenotype and favors its potential use as a prognostic marker in patients with breast cancer.

Binding, Competitive↗
PubMed1995

Quantitative detection of reverse transcriptase-PCR products by means of a novel and sensitive DNA stain.

We constructed a plasmid for the in vitro synthesis of a competitor RNA for use as an internal exogenous control during reverse transcriptase--PCR (RT-PCR) detection of epidermal growth factor receptor (EGFR) expression. The competitor RNA harbors a 32-base deletion compared with wild-type EGFR mRNA and generates a PCR product that is easily distinguished from the wild-type PCR product by agarose gel electrophoresis. We encountered the problem of heteroduplex formation during later stages of PCR, which could be solved by decreasing the PCR cycle number. This was accompanied by a significant loss of sensitivity. Sensitivity could be restored by using a novel and extremely sensitive DNA stain (SYBR Green I) instead of ethidium bromide.

Base Sequence↗
PubMed1994

Patterns of allele losses suggest the existence of five distinct regions of LOH on chromosome 17 in breast cancer.

Chromosome 17 is a frequent target during breast-cancer formation and progression. It has been shown to be affected by allele losses at multiple sites, as well as by DNA amplification. Our aim was to delineate a map of the genetic alterations on chromosome 17 in a given set of breast tumors. To this end we analyzed 151 pairs of tumor and cognate lymphocyte DNAs by Southern blotting with 5 RFLP or VNTR probes and by PCR at 8 CA repeat polymorphic loci for LOHs. Moreover, we studied DNA amplification of the evi2, erbB2, thraI, gcsf and rara genes. Data presented here point strongly to the existence of 5 distinct regions of allele losses on chromosome 17:2 on 17p, 3 on 17q. Of the 2 regions on 17p, one involves tp53 while the second is located more distally toward the telomere. LOH was found in 45.9% and 58.8% respectively. The 3 regions on 17q are located: (i) on the proximal portion of the long arm band q21, corresponding to the brcaI region; (ii) in a central region defined by the marker D17S74; (iii) on the distal part of 17q (band q25) characterized by losses of the marker D17S24. Each of these regions presented respectively allele losses in 47.5%, 33.3% and 40.8% of the informative tumors. Whereas some tumors presented patterns of LOH consistent with the loss of a complete chromosomal arm or of large portions of the chromosome, a high proportion of the analyzed tumors showed interstitial losses. Amplifications were found in 15% of the tumors and were centered around erbB2.(ABSTRACT TRUNCATED AT 250 WORDS)

Alleles↗
PubMed1994

Patterns of DNA amplification at band q13 of chromosome 11 in human breast cancer.

In an attempt to verify the nature of amplification events at band q13 on chromosome 11 we surveyed the amplification status of ten molecular markers specific for this region (GSTP, SEA, D11S97, D11S146, BCLI, PRADI/CCNDI, HST/FGF4, INT2/FGF3, EMSI, and DIIS833E) in a panel of 389 primary breast carcinoma DNA samples. Eighty-eight tumors (23%) showed at least one of these markers amplified, but in a majority of the cases amplification encompassed more than one of the tested loci. Our data confirm that amplicons at 11q13 can cover large portions of DNA and are consistent with the existence of several cores of amplification. One important core seems to be, as previously described, centered around PRADI/CCNDI; 57 tumors (14.7%) showed amplification at PRADI/CCNDI either alone (one tumor) or along with amplification of BCLI or INT2/FGF3. The level of amplification of PRADI/CCNDI sometimes exceeded that of surrounding markers. Three additional amplification events occurring independently of amplification of PRADI/CCNDI were also detected. Centromeric to BCLI, probes to DIIS97, and DIIS146 detected amplification in 60 tumors (15.4%) and were often the only amplified markers. Telomeric to INT2/FGF3, DIIS833E was found amplified alone in ten tumors, and it was the most amplified marker in another six cases. At a shorter distance of INT2/FGF3, EMSI was the only amplified marker in two tumors, with a level of amplification that could exceed that of PRADI/CCNDI and DIIS833E. Our data thus suggest the existence of four independent amplified regions within band 11q13 in breast cancer.

Breast Neoplasms↗