Biomedical subjects

Clemens B Tempfer

Publications and source records attributed to Clemens B Tempfer.

28 records · Page 2Linked to original sources

PubMed2003

An interleukin-6 gene promoter polymorphism influences the biological phenotype of ovarian cancer.

Interleukin (IL)-6 is known to be involved in the pathogenesis of ovarian cancer. We investigated a common G/C polymorphism at position -174 of the IL-6 gene (IL6) promoter in 121 patients with ovarian cancer using pyrosequencing. Presence of at least one mutant allele was associated with early tumor stage as well as an expanded length of disease-free (DFS) and overall survival with a dose-dependent effect regarding the carriage of 0, 1, and 2 alleles. In a multivariate Cox regression model incorporating tumor stage and residual tumor mass, presence of the -174 C allele of IL6 was the best predictor of DFS. We conclude that the mutant -174 C allele of IL6 influences the biological phenotype of ovarian cancer because it is associated with early stage and improved DFS and overall survival.

Adenocarcinoma, Clear Cell↗

PubMed2002

Accessing single nucleotide polymorphisms in genomic DNA by direct multiplex polymerase chain reaction amplification on oligonucleotide microarrays.

This study introduces a DNA microarray-based genotyping system for accessing single nucleotide polymorphisms (SNPs) directly from a genomic DNA sample. The described one-step approach combines multiplex amplification and allele-specific solid-phase PCR into an on-chip reaction platform. The multiplex amplification of genomic DNA and the genotyping reaction are both performed directly on the microarray in a single reaction. Oligonucleotides that interrogate single nucleotide positions within multiple genomic regions of interest are covalently tethered to a glass chip, allowing quick analysis of reaction products by fluorescence scanning. Due to a fourfold SNP detection approach employing simultaneous probing of sense and antisense strand information, genotypes can be automatically assigned and validated using a simple computer algorithm. We used the described procedure for parallel genotyping of 10 different polymorphisms in a single reaction and successfully analyzed more than 100 human DNA samples. More than 99% of genotype data were in agreement with data obtained in control experiments with allele-specific oligonucleotide hybridization and capillary sequencing. Our results suggest that this approach might constitute a powerful tool for the analysis of genetic variation.

Algorithms↗

PubMed2002

The prognostic value of immunohistochemically detected CD44v3 and CD44v6 expression in patients with surgically staged vulvar carcinoma: a multicenter study.

BACKGROUND: Isoforms of the adhesion molecule CD44 are involved in carcinogenesis and the metastatic cascade of tumor cells by increasing the affinity of malignant cells to their extracellular matrix. Preliminary data with respect to the prognostic value of the CD44 isoforms CD44v3 and CD44v6 in patients with vulvar carcinoma showed promising results. The current multicenter study aimed to determine the prognostic value of CD44v3 and CD44v6 in patients with surgically staged vulvar carcinoma. METHODS: Expression of CD44v3 and CD44v6 in vulvar carcinoma tissue was assessed by immunohistochemistry. Immunohistochemical staining was performed according to established protocols. Results were correlated to clinical data. RESULTS: A positive CD44v3 and CD44v6 staining was detected in 33.3% (33 out of 99) and 39.4% (39 out of 99) of the tumor samples, respectively. Overexpression of CD44v6 was associated with an impaired prognosis with respect to disease-free survival (P = 0.01) and overall survival (P = 0.04). Multivariate analysis showed that CD44v6 provided prognostic information with respect to disease-free survival (P = 0.001) and overall survival (P = 0.005) independently of the two established prognosticators, tumor stage and groin lymph node involvement. Overexpression of CD44v3 had no impact on patient survival. CONCLUSIONS: The current multicenter study, involving a large series of patients with surgically staged vulvar carcinoma, allowed for multivariate survival analysis and showed that CD44v6 confers prognostic information in addition to that provided by the established clinicopathologic parameters of tumor stage and lymph node status.

Adult↗

PubMed2002

Polymorphisms of the endothelial nitric oxide synthase gene in ovarian cancer.

OBJECTIVE: The free radical nitric oxide is known to be critically involved in ovarian carcinogenesis by inducing apoptosis and by mediating various cytostatic and cytotoxic effects, but also by promoting growth, invasion, and metastasis. METHODS: We investigated two polymorphisms (exon 7 Glu298Asp and a 27-bp repeat in intron 4) of the gene encoding endothelial nitric oxide synthase (Nos3) in 130 patients with ovarian cancer, 26 patients with borderline ovarian cancer, and 133 healthy age-matched Caucasian women using PCR and pyrosequencing, respectively. RESULTS: Genotypes and allelic frequencies did not differ between patients with ovarian cancer and controls. Within the ovarian cancer group, however, the presence of at least one mutant allele of intron 4 was associated with advanced tumor stage and positive lymph node involvement, but not with tumor grading. The presence of the mutant allele of exon 7 was not associated with the investigated clinicopathological parameters. No correlation with patients' overall and disease-free survival was ascertained. CONCLUSIONS: We are the first to report on Nos3 polymorphisms in ovarian cancer. Allelic variation within intron 4 of Nos3 is associated with an advanced tumor stage and positive lymph node involvement in ovarian cancer.

Alleles↗

PubMed2002

A polymorphism of the Nos3 gene and age at natural menopause.

To investigate the possible influence of a polymorphism of the Nos3 gene on menarche and onset of menopause in humans. Cohort study.Academic research institution.Ninety-one consecutive Caucasian postmenopausal women. Peripheral venous puncture and a patient questionnaire were administered.A tandem repeat polymorphism in intron 4 of Nos3 was analyzed by polymerase chain reaction amplification. The common B allele was identified on 143 of 182 chromosomes (frequency 0.79). The polymorphic A allele was present on 39 chromosomes (frequency 0.21). The genotype frequencies were as follows: 58.2% (B/B), 40.7% (A/B), and 1.1% (A/A). Age at menarche, number of deliveries, number of miscarriages, and onset of menopause did not differ between genotypes. Smoking and increased body mass index were associated with an earlier onset of natural menopause.In contrast to mouse models, in humans Nos3 does not seem to modulate onset and cessation of menses.

Adult↗

PubMed2002

The C677T polymorphism of the methylenetetrahydrofolate reductase gene and idiopathic recurrent miscarriage.

OBJECTIVE: To investigate the association between the C677T polymorphism of the 5,10-methylenetetrahydrofolate reductase gene (MTHFR), serum homocysteine levels, and idiopathic recurrent miscarriage in a Middle-European white population. METHODS: In a case control study, we investigated 133 women with a history of three or more consecutive pregnancy losses before 20 weeks' gestation and 74 healthy controls with at least two live births and no history of pregnancy loss. A DNA extraction and polymerase chain reaction followed by restriction fragment length polymorphism analysis were used to genotype women for the presence of the MTHFR C677T polymorphism. Serum homocysteine levels were assessed by a fluorescence polarization immunoassay. RESULTS: The MTHFR allele frequencies in women with idiopathic recurrent miscarriage and controls were 34.6% and 21.6%, respectively, for the T allele (mutant) and 65.4% and 78.4%, respectively, for the C allele (wild type) (P =.007, odds ratio 1.9, 95% confidence interval 1.2, 3.1). The MTHFR genotype frequencies in women with idiopathic recurrent miscarriage and controls were: 17.3% (T/T), 34.6% (C/T), 48.1% (C/C) and 5.4% (T/T), 32.4% (C/T), 62.2% (C/C), respectively (P =.03, odds ratio 3.7, 95% confidence interval 1.2, 11.8 [T/T versus C/T and C/C]). Serum concentrations of homocysteine were significantly higher in carriers of a MTHFR mutant allele compared with women with no mutant allele (mean 7.4 +/- 2.4 micromol/L [T/T + C/T] versus 6.5 +/- 2.6 micromol/L [C/C], P =.05). CONCLUSION: Carriage of the mutant allele of the MTHFR C677T polymorphism is associated with elevated serum levels of homocysteine and idiopathic recurrent miscarriage.

Abortion, Habitual↗

PubMed2002

Drug therapy of urinary urge incontinence: a systematic review.

OBJECTIVE: To review the efficacy of drug therapy for urinary urge incontinence by examining the published literature. METHODS OF STUDY SELECTION: In October 1999, we searched the medical databases MEDLINE, EMBASE, and Cochrane Controlled Trials Register to identify prospective randomized, double-blind, placebo-controlled clinical trials in the English literature evaluating drug therapy (except hormonal therapy) of urinary urge incontinence. Trials were categorized by type of drug and outcome variables. TABULATION, INTEGRATION, AND RESULTS: Forty-seven trials were identified. Twenty-four, 12, and 11 trials evaluated anticholinergic drugs, drugs with anticholinergic and calcium antagonistic properties, and alternative regimens, respectively. Data regarding treatment effects of anticholinergic drugs are consistent with a high therapeutic efficacy and characteristic side effects. Therapeutic efficacy and side effect patterns of terodiline, an agent with anticholinergic and calcium antagonistic properties, were comparable to those of anticholinergic agents. Terodiline, however, has been withdrawn from the market because of its association with cardiac arrhythmia. Of the investigated alternative drug regimens, the papaverine-like smooth muscle relaxant flavoxate was reported to be ineffective. Studies investigating the dopamine agonist bromocryptine, the alpha-adrenoceptor blocker prazosin, or the gamma-aminobutyric acid receptor agonist baclofen showed subjective and/or objective improvement of symptoms without reaching statistical significance, whereas the tricyclic antidepressant doxepin, the neurotoxin capsaicin, and the prostaglandin synthase inhibitor flurbiprofen led to statistically significant subjective and/or objective improvement of symptoms. No data for subjective and/or objective improvement of symptoms could be extracted from the studies using the anticholinergic and calcium antagonistic agent propiverine and the calcium antagonist thiphenamil. CONCLUSION: Published trials support anticholinergic drugs as efficacious therapy for urinary urge incontinence, with predictable side effects. At present, these agents represent the pharmacological treatment of choice for this condition. The potential value of selected alternative drugs is underscored by the available data.

Calcium Channel Blockers↗

PubMed2002

Polymorphisms of the angiotensinogen gene, the endothelial nitric oxide synthase gene, and the interleukin-1beta gene promoter in women with idiopathic recurrent miscarriage.

Interleukin (IL)-1beta, angiotensinogen (Agt), and endothelium-derived nitric oxide synthase (eNOS) are thought to be involved in idiopathic recurrent miscarriage (IRM). We investigated the correlation between IRM and common polymorphisms in Agt, Nos3 and IL-1beta genes: one polymorphism in the promoter region of the IL-1beta gene, one in exon 2 of the Agt gene, and one in exon 7 of the Nos3 gene. A total of 130 women with a history of IRM and 67 healthy control women were included in the study. Genotyping for the C/T transition at position -511 in the promoter region of IL1B, for the single base M235T polymorphism of Agt, and for the missense Glu298Asp variant of Nos3 was performed using PCR, an allele-specific oligonucleotide hybridization assay, and pyrosequencing, respectively. Allele and genotype frequencies of all polymorphisms were similar among women with IRM and controls. Between women with primary and secondary recurrent miscarriages, no statistically significant differences between allele and genotype frequencies were observed. Despite promising experimental data, our data fall short of showing any significant association between a variant of the promoter region of IL1B, the M235T polymorphism of Agt, and the Glu298Asp missense variant of Nos3 and the occurrence of IRM.

Abortion, Habitual↗

PubMedDate not supplied

Polymorphisms associated with thrombophilia and vascular homeostasis and the timing of menarche and menopause in 728 white women.

OBJECTIVE: Genetic factors have been proposed as modulators of the timing of natural menopause. Single nucleotide polymorphisms (SNPs) of genes associated with thrombophilia and vascular homeostasis may interfere with ovarian function and thus are candidate genes for early menopause. We attempted to assess the association of SNPs and the timing of menarche and natural and surgical menopause in an ethnically homogenous cohort of Middle European white women. DESIGN: In the present cross-sectional study, eight SNPs of six genes involved in vascular function and homeostasis were analyzed by sequencing-on-chip using solid-phase polymerase chain reaction on oligonucleotide microarrays in 728 white women: factor V (F5) Leiden G1691A, factor II (F2) prothrombin G20210A, plasminogen activator inhibitor1 (PAI-1) 4G/5G, angiotensinogen (AGT) Met235Thr, endothelial nitric oxide synthase (NOS3) T768C and NOS3 Glu298Asp, apolipoprotein E-1 (APOE-1) Cys112Arg, and APOE-2 Arg158Cys. The women's reproductive and medical histories were correlated to genotypes. RESULTS: In a univariate analysis, current smoking (P = 0.01) and the presence of at least one mutant allele of F5 Leiden (P = 0.03) and APOE-2 (P = 0.03) were significantly associated with a reduced age at natural menopause. The presence of at least one mutant allele of F5 Leiden (P = 0.02) and a body mass index above 25 kg/m (P = 0.009) were significantly associated with an increased risk for surgical menopause by premenopausal hysterectomy (odds ratio = 2.6, 95% CI, 1.2-5.6; odds ratio = 1.9, 95% CI, 1.2-3.0, respectively). Age at menarche was not affected by the carriage of any of the investigated SNPs. Applying stepwise linear regression models considering all two-way interactions, no interactions were found among different SNPs or between SNPs and environmental and lifestyle parameters. CONCLUSION: We identified various genetic and personal history parameters influencing age at natural menopause and the risk of undergoing premenopausal hysterectomy. To the best of our knowledge, we present the largest study to date determining SNPs as contributors to the genetic control of the timing of natural and surgical menopause.

Angiotensinogen↗

PubMedDate not supplied

Polymorphisms of the interleukin-1 gene cluster and ovarian cancer.

OBJECTIVE: Interleukin-1 (IL-1) is known to be critically involved in ovarian carcinogenesis. We investigated a panel of polymorphisms of the IL-1 and the IL-1 receptor antagonist (IL-1 RA) genes in patients with ovarian cancer. METHODS: One hundred thirty-four patients with surgically staged ovarian cancer, 27 patients with borderline ovarian cancer, and 134 healthy controls were genotyped for three polymorphisms of the IL-1 gene (-889 C/T polymorphism of the IL-1alpha gene [IL1A], -511 C/T polymorphism of the IL-1beta promoter [IL1B promoter], a polymorphism of IL-1beta exon 5 [IL1B exon 5]), and an 86-base pair repeat in intron 2 of the IL-1 RA gene [IL1RN]) using polymerase chain reaction and pyrosequencing. RESULTS: Allelic frequencies did not differ between patients with ovarian cancer and controls. In the ovarian cancer group, polymorphism did not correlate with any of the investigated clinicopathologic variables, including tumor stage, lymph node, and histologic grade. In univariate and multivariate models, there was no correlation between any polymorphism and patients' overall and disease-free survival. CONCLUSION: We investigated interleukin polymorphisms in ovarian cancer but did not find any association between common polymorphisms of IL1A, IL1B, and IL1RN and the occurrence of ovarian cancer. Allelic variation within the IL-1 gene clusters does not seem to play a role in ovarian carcinogenesis and does not appear to be a useful tool for possible screening and risk evaluation.

Alleles↗