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Biomedical subjects

C Friedl

Publications and source records attributed to C Friedl.

7 recordsLinked to original sources
PubMed2007

Steroid receptors ERalpha, ERbeta, PR-A and PR-B are differentially expressed in normal and atrophic human endometrium.

OBJECTIVE: The endometrium expresses estrogen (ER) and progesterone receptor (PR), which are related to autocrine and paracrine processes that respond to estrogen and progesterone. Therefore, the aim of this study was to evaluate the distribution pattern of ERalpha, ERbeta, PR-A and PR-B with monoclonal antibodies in normal human endometrial tissue. STUDY DESIGN: Human endometrial tissue was obtained from 84 premenopausal and 11 postmenopausal patients and immunohistochemically analysed with monoclonal antibodies against ERalpha, ERbeta, PR-A and PR-B. RESULTS: ERalpha, PR-A and PR-B declined significantly (p<0.001, p<0.05, p<0.05 respectively) in glandular epithelium from proliferative to late secretory phase. The ERbeta immunohistochemical reaction showed a similar significant declining pattern (p<0.05), although the staining intensity was lower than that of ERalpha. While ERalpha, ERbeta and PR-B decrease significantly in atrophic endometrial tissue compared to proliferative endometrium, a significant up-regulation of PR-A was observed compared to late secretory phase (p<0.05). CONCLUSION: ERalpha, ERbeta, PR-A and PR-B were expressed in normal human endometrium with a cyclical variation during the menstrual cycle. In normal postmenopausal endometrial tissue, a down-regulation of ERalpha, ERbeta and PR-B occurs with a subsequent higher expression of PR-A. These results show the presence of steroid receptors in human epithelium, indicating that these cells respond to estrogen and progesterone, thus playing a significant role in endometrial physiology.

Atrophy↗
PubMed2000

Differential frequencies of p16(INK4a) promoter hypermethylation, p53 mutation, and K-ras mutation in exfoliative material mark the development of lung cancer in symptomatic chronic smokers.

PURPOSE: The aim of this study was to investigate the frequency of three (epi)genetic alterations (p53 and K-ras mutations and p16(INK4a) promoter hypermethylation) in symptomatic chronic smokers compared with patients with lung cancer and to evaluate the use of exfoliative material for such analyses. PATIENTS AND METHODS: Fifty-one patients with histologically confirmed lung cancer and 25 chronic smokers (> 20 pack-years) were investigated for mutations in the K-ras (codon 12) and p53 (codons 248, 249, and 273) genes and for allelic hypermethylation of the p16(INK4a) gene. DNA was isolated from sputum and bilateral bronchial lavage, and brushings were taken at bronchoscopy. RESULTS: Forty-one genetic lesions were detected within exfoliative material from the group of 51 patients with lung cancer and 10 lesions in the chronic smoker group. K-ras mutations occurred exclusively in the lung cancer group, whereas p53 mutations and p16(INK4a) promoter hypermethylation were also found in chronic smokers. Three of eight chronic smokers who harbored an (epi)genetic alteration were subsequently diagnosed with lung cancer. Analysis of sputum yielded information equivalent to that of samples obtained during bronchoscopy. CONCLUSION: p16(INK4a) promoter hypermethylation and p53 mutations can occur in chronic smokers before any clinical evidence of neoplasia and may be indicative of an increased risk of developing lung cancer or of early disease. K-ras mutations occur exclusively in the presence of clinically detectable neoplastic transformation. Molecular analysis of sputum for such markers may provide an effective means of screening chronic smokers to enable earlier detection and therapeutic intervention of lung cancer.

Aged↗
PubMed1986

Fast protein chromatofocusing of human very-low-density lipoproteins.

Using fast protein chromatofocusing, a high-efficiency column chromatography method with a self-generated pH gradient and focusing effects, soluble human very-low-density lipoprotein (VLDL) apolipoproteins were fractionated between pH 6.3 and 4.0. In the presence of 6 mol/l urea and with a flow rate of 1 ml/min, one run (up to 10 mg of protein) took 30 min. VLDL apolipoproteins were separated in seven peaks. As revealed by SDS-polyacrylamide gel electrophoresis, isoelectric focusing and double-immunodiffusion against mono-specific antisera, fractions corresponded to the following proteins: apolipoprotein C-I, albumin, apolipoproteins A-I, E, C-II plus C-III0, C-III1 and C-III2, respectively. Apolipoproteins were eluted in sharp, well-resolved peaks. The recovery of proteins was 78% of the starting material. With fast protein chromatofocusing, an efficient isolation of single apolipoproteins is possible from small amounts of VLDL apolipoprotein preparations. This technique is superior to the commonly used, time-consuming methods for apolipoprotein isolation.

Electrophoresis, Polyacrylamide Gel↗
PubMed1986

Isolation and quantification of apolipoproteins C-I, C-II, and C-III0-2 in very-low-density lipoproteins by "high-performance" anion-exchange chromatography.

Using "high-performance" anion-exchange chromatography, we isolated and quantified human C apolipoproteins (apo C) from very-low-density lipoproteins (VLDL) in serum. As revealed by isoelectric focusing and double immunodiffusion against monospecific antisera, apo C-I, apo C-II, apo C-III0, apo C-III1, and apo C-III2 were purified to homogeneity. Assay reproducibility (coefficients of variation) ranged between 0.9% and 4.7%. The relative percentages of apo C subspecies in VLDL from normal and hypertriglyceridemic serum samples agreed with data obtained by alternative methods. This precise technique is suitable for detecting and analyzing abnormalities of C apolipoproteins in VLDL.

Apolipoprotein C-I↗
PubMed1979

The ATP synthetase of Escherichia coli K12: purification of the enzyme and reconstitution of energy-transducing activities.

The ATP synthetase of Escherichia coli K12 was purified by a simple procedure. The dicyclohexylcarbodiimide-sensitive ATPase activity was enriched 21-fold. The ATP synthetase preparation contained the eight polypeptides (alpha, beta, gamma, a,delta, b,espilon, c) of the enzyme and a residual contamination (4% of the total protein) as shown by dodecylsulfate/polyacrylamide electrophoresis. The polypeptide c was specifically labelled with [14C]dicyclohexylcarbodiimide. Energy-transducing activities were reconstituted from soybean phospholipids and the purified enzyme. The proteoliposomes exhibited a significantly higher ATP-32Pi exchange activity and a higher proton-translocating activity as compared to the untreated membranes.

Adenosine Diphosphate↗