Biomedical subjects

Petra Neufing

Publications and source records attributed to Petra Neufing.

6 recordsLinked to original sources

PubMed2007

Changes in steroid receptors and proteoglycan expression in the guinea pig prostate stroma during puberty and hormone manipulation.

BACKGROUND: Proteoglycans are structural and informational molecules important during embryogenesis and organ maturation. Maturation of the prostate is influenced by androgens and estrogens, but changes in the relative spatiotemporal expression of steroid receptors and proteoglycans during hormonal change are unexplored. METHODS: Guinea pig prostate was used to define hormone-induced changes in the expression of androgen (AR) and estrogen (ER(alpha)) receptors, chondroitin sulfate (CS) glycosaminoglycan and core proteins of versican and syndecan-1. Tissue locations of AR, ER(alpha), CS and the proteoglycans versican and syndecan-1 were determined by immunohistochemistry. Cellular content of ER(alpha) and syndecan-1 was assessed visually. Versican, CS56 epitope, and AR were quantified by image analysis. RESULTS: AR expression within prostate epithelial and stromal cell nuclei decreased following castration and increased following treatment of castrate animals with dihydrotestosterone (DHT). ER(alpha) expression was restricted to prostate stromal cell nuclei and decreased during puberty, and following treatment of castrate animals with DHT. Versican was present in periacinar stroma immediately peripheral to basal epithelial cells, fibromuscular stromal tissue bands surrounding acinar units, and loose fibrovascular connective tissue interspersed between individual acini. Versican and native CS expression decreased (>10-fold) in periacinar stroma during puberty and following administration of DHT to castrated animals. Expression of syndecan-1 was restricted to fibromuscular cells of prostate stroma, and remained constant during puberty and hormone manipulation. CONCLUSIONS: ER(alpha), versican core protein and CS side chain epitopes are negatively regulated in prostate stromal tissue by DHT, whilst AR levels are positively regulated.

Androgens↗

PubMed2006

Variants in the prostate-specific antigen (PSA) gene and prostate cancer risk, survival, and circulating PSA.

An A to G substitution, rs925013, in the promoter of the prostate-specific antigen gene (PSA) was recently found to be associated with promoter activity and circulating PSA levels. The objective of this study was to test the associations between rs925013 and another A to G substitution, rs266882, in the PSA gene with prostate cancer risk using a population-based case-control study of 821 prostate cancer cases and 734 controls carried out in Perth and Melbourne, Australia. The study focused on young (i.e., < 70 years) and aggressive cases (i.e., well-differentiated tumors were excluded). Cases in the Melbourne arm of the study (N = 638) were followed up prospectively for an average period of 8.2 years and deaths from prostate cancer ascertained through record linkage to study the possible association between genetic variants and disease-specific survival. PSA-circulating levels were measured in controls to test the association with the genetic variants using a cross-sectional design. Linear regression of log PSA levels, unconditional logistic regression, Cox regression, and haplotype analyses were undertaken. For rs925013, the G allele was associated with an increased risk of prostate cancer [odds ratio, 1.4; 95% confidence interval (95% CI), 1.1-1.7; P = 0.001], and the hazard ratio for survival for cases homozygous for the G allele compared with cases homozygous for the A allele was increased but not statistically significant (hazard ratio, 2.3; 95% CI, 1-5.6; P = 0.06). For rs266882, there was no association with overall prostate cancer risk and survival (all P > 0.1). Men homozygous or heterozygous for the G/G (rs925013/rs266882) haplotype were at higher risk of prostate cancer than men homozygous for the A/A haplotype (odds ratio, 1.3; 95% CI, 1.1-1.7; P = 0.009). Adjusted geometric means of circulating PSA levels in controls were similar in men with zero, one, and two copies of the G allele in rs266882 (1.2, 1.1, and 1.3 ng/mL, respectively; all P > or = 0.2) and rs925013 (1.1, 1.2, and 1.5 ng/mL, respectively; all P > 0.1). For rs925013, our study provides good evidence of association with prostate cancer risk, marginal evidence of association with survival, and little evidence of detectable association with circulating PSA levels in controls. We found no evidence of an independent association between rs266882 and any of the outcomes. The genotypes and haplotypes studied might be associated with the PSA gene function or be in linkage disequilibrium with other unmeasured and functional variants in the PSA or other genes.

Aged↗

PubMed2005

Androgen receptor levels in prostate cancer epithelial and peritumoral stromal cells identify non-organ confined disease.

BACKGROUND: Although up to 30% of men who undergo radical prostatectomy for clinically organ-confined prostate cancer will relapse with disseminated disease, currently it is not possible to predict these patients. METHODS: Androgen receptor (AR) immunoreactivity in stromal and epithelial compartments of tumor foci was evaluated by video image analysis in 53 radical prostatectomy specimens. Kaplan-Meier and Cox Regression analyses were used to determine whether AR immunostaining was related to rate and risk of relapse, respectively. RESULTS: Ninety-eight percent (52/53) of the tumors contained AR positive malignant epithelial cells. Kaplan-Meier analysis indicated that patients with high AR levels (>64% AR positive nuclear area) in the malignant epithelial cells or low AR levels (<or=45% AR positive nuclear area) in the peritumoral stroma cells, were more likely to relapse earlier following radical prostatectomy. The shortest time to relapse and the highest relapse rate was for patients with both high AR in the malignant epithelial cells and low AR in the peritumoral stromal cells. CONCLUSIONS: These findings suggest that AR is an important determinant of disease relapse in early stage prostate cancer, and that altered AR levels in the malignant epithelial cells or in the peritumoral stroma is indicative of non-organ confined prostate cancer.

Aged↗

PubMed2003

ELAC2/HPC2 polymorphisms, prostate-specific antigen levels, and prostate cancer.

BACKGROUND: The ELAC2 gene has been proposed to be a prostate cancer susceptibility gene and is being referred to as HPC2, in part because three case-control studies suggested that two common polymorphisms (Ser217Leu and Ala541Thr) are associated with risk. However, four subsequent larger studies have not confirmed this association. In five of the seven total studies, subject selection was influenced by prostate-specific antigen (PSA) levels. We examined the association and possible effect of subject selection in a larger study and a meta-analysis. METHODS: In a population-based study in Australia, 825 case patients and 732 control subjects were genotyped for the Ser217Leu and Ala541Thr polymorphisms of ELAC2. Odds ratios (ORs) for prostate cancer were estimated by unconditional logistic and polytomous regression. A meta-analysis was conducted combining our data with those from seven published studies. The association of genotype with the logarithm of plasma PSA levels in control subjects was analyzed by linear regression. RESULTS: The ORs for prostate cancer were 0.74 (95% confidence interval [CI] = 0.50 to 1.09) for Leu217 homozygotes and 1.01 (95% CI = 0.68 to 1.50) for Thr541 heterozygotes and homozygotes compared with Ser217 and Ala541 homozygotes, respectively. ORs were not changed by excluding control subjects with elevated PSA levels. Among control subjects, there were no statistically significant associations between genotype frequencies and PSA level for either polymorphism (both P>.4). The meta-analysis gave pooled OR estimates of 1.04 (95% CI = 0.85 to 1.26) for Leu217 homozygotes and 1.18 (OR = 0.98 to 1.42) for Thr541 homozygotes and heterozygotes. CONCLUSION: There is no evidence that either ELAC2 polymorphism is associated with prostate cancer or PSA level.

Aged↗

PubMedDate not supplied

A functional autoantibody in narcolepsy.

Narcolepsy is widely believed to have an autoimmune basis, but conventional immunological approaches have failed to detect a serum autoantibody marker. Since cholinergic hyperactivity is a feature of narcolepsy-cataplexy, we transferred IgG from nine patients with narcolepsy and nine healthy controls to mice and assessed the effect on smooth muscle contractile responses to cholinergic stimulation. IgG from all narcolepsy patients significantly enhanced bladder contractile responses to the muscarinic agonist carbachol and to neuronally released acetylcholine compared with control IgG (p<0.0001), whereas contraction of the sympathetically innervated vas deferens was unaltered. Our findings provide direct evidence for the autoimmune hypothesis of narcolepsy.

Adult↗

PubMedDate not supplied

Expression and localization of homeodomain proteins DLX4, HB9 and HB24 in malignant and benign human colorectal tissues.

BACKGROUND: The purpose of this study was to identify homeobox genes expressed in the human colon and to determine whether their expression levels were altered between matched non-malignant and malignant colon tissues. MATERIALS AND METHODS: Homeobox genes expressed in colon tissue were identified by reverse transcription polymerase chain reaction (RT-PCR). Antibodies were raised to the homeodomain proteins DLX4, HB9 and HB24 and immunohistochemistry was performed on 3 moderately-differentiated tumors and their corresponding non-malignant colon tissue samples. RESULTS: The RT-PCR screen identified expression of DLX4, HB9, HB24 and MSX2 in the normal colon. Immunoaffinity purified polyclonal antisera raised against DLX4, HB9 and HB24 detect specific immunoreactivity in glandular epithelial cells, stromal cells of the lamina propria but not in the submucosa. Nuclear epithelial immunoreactivity of all three antibodies decreased in moderately-differentiated tumors compared to the corresponding matched non-malignant mucosa. These data suggest that differential expression of HB9, HB24 and DLX4 may be associated with colorectal carcinogenesis.

Adult↗