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Biomedical subjects

M van Sande

Publications and source records attributed to M van Sande.

At least 37 records · Page 2Linked to original sources
PubMed1985

Lipids in human benign prostatic hypertrophy.

Lipids in human prostate have been the subject of limited research and the most complete studies were published forty years ago. In this study we report on the total lipid, total cholesterol, free cholesterol and triglyceride content in human benign prostatic hypertrophy. By means of thin-layer chromatography, we separated the cholesterolesters in five fractions. The effect of treatment with anti-androgens before prostatectomy was examined.

Androgen Antagonists↗
PubMed1985

Tripeptidyl carboxypeptidase activity of angiotensin-converting enzyme in human tissues of the urogenital tract.

The tripeptidyl carboxypeptidase activity of angiotensin-converting enzyme (EC 3.4.15.1) has been determined in several human tissues of the urogenital tract. Benzoyl-glycyl-L-seryl-L-prolyl-L-phenylalanine was used as substrate. The cleaved benzoyl-glycine was measured by means of high-performance liquid chromatography. Results obtained showed a high enzymatic activity for seminal plasma, vesicula seminalis and benign prostatic hyperplasia. Normal prostate and in particular prostatic adenocarcinoma have low enzymatic activity. The activity of the enzyme is sensitive to inhibition by the angiotensin-converting enzyme inhibitor captopril.

Adenocarcinoma↗
PubMed1985

Multiple forms of angiotensin-converting enzyme in human tissues and fluids.

Angiotensin-converting enzyme (EC 3.4.15.1) exhibits distinctive tissue differences in electrophoretic behaviour. Human tissue homogenates and biological fluids were subjected to agar gel and polyacrylamide gel electrophoresis. The gels were cut into slices and enzymatic activity detected by a specific colorimetric reaction. The technique allows localization of the enzyme in the electrophoretogram and gives an estimate of the total enzymatic activity of a tissue or biological fluid. Several tissues were found to show multiple forms of angiotensin-converting enzyme. The specificity of the assay was determined by running the samples after the addition of captopril and by adding proteinase inhibitors to the incubation mixture.

Body Fluids↗
PubMed1985

Assay of carboxypeptidase N activity in serum by liquid-chromatographic determination of hippuric acid.

We describe conditions for determining carboxypeptidase N (EC 3.4.17.3) activity by liquid chromatography. Serum (10 microL) is mixed with the artificial substrates hippuryl-L-arginine (30 mmol/L) and hippuryl-L-lysine (100 mmol/L) in 50 mmol/L 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) buffer solution at pH 8.2 and 7.8, respectively. The hippuric acid product is separated from the substrate in less than 2 min by reversed-phase "high-performance" liquid chromatography and measured spectrophotometrically. o-Methyl hippuric acid is used as internal standard. By this method, optimized for activity and sensitivity of detection, carboxypeptidase N activities are 60-fold greater than those by another procedure (J Chromatogr 266:173-177, 1983). The mean value for 80 normal control subjects was 74.8 (SD 10.3) nmol of hippuric acid released per milliliter of serum per minute for hippuryl-L-arginine substrate, 378 (SD 55) for hippuryl-L-lysine substrate. The sensitivity and precision of the method make it suitable both for routine clinical determinations and as a reference procedure.

Adolescent↗
PubMed1983

Alpha 1-antitrypsin, alpha 2-macroglobulin and complement C4 in human benign prostatic hyperplasia.

The concentrations of the globulins alpha 1-antitrypsin, alpha 2-macroglobulin and complement C4 have been determined in tissue samples of benign prostatic hyperplasia, from patients with and without prior treatment before open surgery. Globulins have been determined by means of radial immunodiffusion. Results obtained show that alpha 1-antitrypsin is present in high concentrations in human prostate. Treatment with anti-androgens influences the alpha 2-macroglobulin concentration in the different prostatic lobes. Complement C4 concentration is not influenced by the treatment.

Androgen Antagonists↗
PubMed1983

Immunoglobulins in tissues of human benign prostatic hypertrophy.

The concentrations of immunoglobulins (IgG, IgA and IgM) have been determined in tissues of human benign prostatic hypertrophy by means of different immunological techniques. Results obtained show that IgA is quantitatively the most important immunoglobulin in prostatic tissue. Treatment with anti-androgens can change the Ig-pattern, in particular the levels of IgA and IgM.

Electrophoresis, Agar Gel↗
PubMed1983

Polyamine profiles in human pathological prostate tissue.

Polyamine concentrations were determined in homogenized specimens of human prostatic tissue obtained at open surgery from patients with benign prostatic hypertrophy, some of whom had been treated with oestrogens or anti-androgens, and from patients with prostatic adenocarcinoma in whom the tissues were removed by transurethral resection. The results show that in treated benign prostatic hyperplasia there is a lower polyamine concentration. Homogenates of tissues from patients with prostatic cancer show no specific polyamine profile.

Adenocarcinoma↗
PubMed1981

Lactoferrin in human prostate tissue.

Lactoferrin levels have been determined by radialimmunodiffusion in homogenates of both human benign prostatic hypertrophy obtained at open surgery from patients, some of whom had been treated with oestrogens or antiandrogens, and also in prostatic adenocarcinoma tissue removed by transurethral resection. Results show that in untreated benign prostatic hyperplasia there is a statistically lower lactoferrin level in the median compared with the lateral lobes. In patients with benign prostatic hypertrophy treated before prostatectomy with oestrogens or antiandrogens the lactoferrin concentration is decreased. In neoplastic tissue removed by open surgery, the lactoferrin level is very low. Homogenates of tissue resected from prostatic cancer patients show similarly low levels. The concentration of lactoferrin in human prostate is hormone dependent. The role of the protein is considered to be bacteriostatic.

Adenocarcinoma↗
PubMed1980

Absence of L-histidine lyase and histidine imidazole metabolites in human adenomatous prostate.

The histidine metabolism in homogenates of human tissues of nontreated benign prostatic hyperplasia has been examined by means of the determination of L-histidine ammonia lyase activity (EC 4.3.1.3;histidine alpha-deaminase, histidase) and the histidine imidazole metabolites which were separated by means of ion exchange chromatography. Neither enzymatic activity nor metabolites of histidine could be detected. It is concluded that non-treated benign prostatic hyperplasia lacks L-histidine ammonia lyase activity and subsequently the metabolic pathway of histidine.

Ammonia-Lyases↗
PubMed1979

Free amino acids and ninhydrin-reacting compounds of median and lateral lobes in human benign prostatic hypertrophy.

The levels of free amino acids and ninhydrin-reacting substances were determined in median and lateral lobes of human benign prostatic hypertrophy. Student's paired t test showed only a statistical difference for the hypotaurine concentration. This compound is present at higher levels in the lateral lobes. The different hypotheses formulated in the literature about the presence and possible metabolic role of hypotaurine in the male reproductive tract are examined.

Amino Acids↗