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Biomedical subjects

M Lein

Publications and source records attributed to M Lein.

At least 73 records · Page 4Linked to original sources
PubMed1997

Antioxidant enzymes in malignant prostate cell lines and in primary cultured prostatic cells.

The antioxidant enzymes catalase, glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPx), and superoxide dismutase (SOD) were determined in the androgen-response LNCaP and androgen-nonresponsive PC-3 and DU 145 cells as well as in prostatic epithelial cell cultures of benign and malignant human prostatic tissue. There were no differences between the enzyme activities of the human primary cell cultures from cancerous tissue and their normal counterparts. The enzyme activities of the three permanent cell lines were either higher (SOD, catalase, GR) or lower (GST, GPx) than in the primary cell cultures. In LNCaP cells catalase and GR were significantly higher, GST, in contrast, was significantly lower than in PC-3 and DU 145 cells. GST in PC-3 and DU 145 cells, and SOD in all the three cell lines showed no significant differences. Catalase, GPx and GR values were significantly different in the three permanent cell lines. The different enzymatic equipment of the prostate cancer cell lines provides the basis for experimental testing of new concepts of cancer treatment with the help of systematic modulations of the antioxidant defence systems in prostate cancer.

Antioxidants↗
PubMed1997

Elimination of serum free and total prostate-specific antigen after radical retropubic prostatectomy.

Elimination kinetics of serum total and free prostate-specific antigen were studied for a ten days course after radical retropubic prostatectomy on 11 patients suffering from organ confined prostate cancer. Samples were taken before operation, immediately after finishing the operation and 1, 2, 3, 4, 5, 6 h after prostatectomy and then once a day for the following ten days. The measurements were performed with AxSym assays from Abbott Laboratories. The elimination of both total and free prostate-specific antigen followed a biphasic kinetics. In the fast phase, the average of the individual elimination half-lives of total and free prostate-specific antigen amounted to 6.3 h (SD = 6.1 h; range: 0.55 to 37.1 h) and 0.57 h (SD = 0.18 h; range: 0.22 to 0.89 h), respectively. In the slow phase, total prostate-specific antigen disappeared with an average half-life of 85.6 h (SD = 11 h; range: 47.2 to 261.7 h) and free prostate-specific antigen with an average half-life of 14.4 h (SD = 10.4 h; range: 2.4 to 30.3 h). These results might be significant for the use of free and total prostate-specific antigen and its ratio as a diagnostic and prognostic tool.

Aged↗
PubMed1996

Soluble CD44 molecules in serum of patients with prostate cancer and benign prostatic hyperplasia.

Recent studies suggest that expression of CD44 splice variants are of prognostic significance for a variety of neoplasias. It was the aim of this study to investigate whether any correlation exists between the concentration of soluble CD44 molecules in serum (CD44 standard form and CD44 splice variants v5 and v6) and the prostate cancer stage. Serum levels of these soluble CD44 isoforms were measured by ELISA tests specific for these proteins in controls (n = 30), patients with benign prostatic hyperplasia (BPH; n = 30), with prostate cancer without metastasis (T1,2,3pN0M0; n = 30) and with locally advanced prostate cancer and/or metastatic disease (T3,4pN1,2M1; n = 19). sCD44std and sCD44v6 concentrations were not significantly different among the four groups studied, with few patients' levels outside the central 95% reference intervals. The mean sCD44v5 concentrations of both prostate cancer and BPH patients were significantly lower than those of the controls. There was no significant difference between the soluble CD44 concentrations of the two groups of prostate cancer patients studied. In contrast to results observed in other carcinomas, the determination of soluble CD44 proteins in serum is not suitable for providing additional prognostic information on patients with prostate cancer.

Adult↗
PubMed1996

Comparison between equimolar- and skewed-response assays of prostate specific antigen: is there an influence on the clinical significance when measuring total serum prostate specific antigen?

Using the Tandem-E, Axsym and LIA-mat assays, prostate specific antigen (PSA) was measured in pure PSA solutions of known concentrations of free and complexed PSA and in serum of patients with prostate cancer (n = 31), benign prostate hyperplasia (n = 32) and in healthy controls (n = 27). Measurements of pure PSA solutions showed that the AxSym assay exemplified typical properties of the skewed-response assay reacting more to free PSA than to the complexed PSA forms whereas the other two assays showed an equimolar-response. When PSA was measured in the serum of the tree groups, the AxSym test and Tandem-E gave similar PSA values whereas the LIA-mat test yielded significantly lower values. These results were not related to the amount of free PSA in the samples and proved that discordant PSA values between PSA assays were not mainly caused by the use of skewed- or equimolar assays. Despite these differences, receiver-operation characteristic analysis confirmed that the clinical validity of all three PSA tests did not differ.

Aged↗
PubMed1996

The pharmacological effect of the gonadotrophin-releasing hormone on experimental cryptorchidism in rats.

Cryptorchidism is the most frequent congenital disturbance in males requiring both medical and surgical interventions. The involved testicle shows severe pathological changes. In an effort to test new medical treatments, we established a rat model for induced cryptorchidism using two estradiol treatment regimens and evaluated the effects of GnRH and an analogue D-Phe-GnRH on rate of testicular descent and on improvement of abnormal testicular histology. We found that the duration of estradiol treatment and not the total dose was related to delayed recovery from testicular descent. No significant effect of GnRH on testicular descent was observed. D-Phe-GnRH significantly improved the rate of testicular descent in rats treated 40 days with estradiol, but not in those treated 30 days with estradiol. The histologic examination of estradiol-induced undescended testes revealed severe morphological changes with a low number of germ cells, infiltration with lymphocytes, fibrosis and smaller diameter of seminiferous tubules. These changes were not improved with GnRH. D-Phe-GnRH was able to correct some of the histologic changes of estradiol-induced cryptorchidism. We established an animal model for testing of medical treatments for cryptorchidism. Our study may be indicative of a new treatment strategy using D-Phe-GnRH in the non-surgical treatment of cryptorchidism in human.

Animals↗
PubMed1996

Analytical performance and clinical validity of two free prostate-specific antigen assays compared.

We compared two recently introduced commercial assays (CanAg and Immulite) for measuring free prostate-specific antigen (f-PSA), total PSA (t-PSA), and the ratio of t-PSA/f-PSA (f-PSA%) in control materials and sera of 54 healthy men, 50 patients with benign prostatic hyperplasia (BPH), and 45 patients with prostate cancer (PCa). The lower detection limits for f-PSA were 0.038 microgram/L and 0.004 microgram/L for the CanAg and Immulite assays, respectively. The within-run and between-day precisions of the Immulite assay were < 5%; the CanAg assay showed a poorer precision. Whereas f-PSA values differed between controls and patients but not between BPH and PCa patients, the f-PSA% values were lower in PCa patients than in BPH patients and controls. The receiver-operating characteristic (ROC) curve showed an improved diagnostic power of f-PSA% compared with t-PSA to discriminate between BPH and PCa. Discrimination limits of 16% (CanAg assay), and 15% (Immulite assay) are recommended for f-PSA%.

Autoanalysis↗
PubMed1996

Strip test for the quick detection of increased concentrations of prostate-specific antigen in blood.

We tested the performance of the new immunochemical membrane test BioSign PSA for detecting serum concentrations of prostate-specific antigen > 4 micrograms/l. Measurements were simultaneously performed on 161 serum samples, using the strip test and three quantitative assays of prostate specific antigen (Tandem-E, IMx, LIA-mat). Based on the upper reference limit of 4 micrograms/l, 11-37% of the results obtained with the BioSign test were false-negative and 4-15% were false-positive, compared with the data of the three quantitative assays. It is concluded that the BioSign test in its present form does not satisfactorily differentiate between prostate-specific antigen concentrations above and below 4 micrograms/l, but an improved version of the test would be useful.

Adult↗
PubMed1996

Laparoscopic adrenalectomy.

Fifteen patients with benign adrenal tumors underwent laparoscopic adrenalectomy for the following indications: six pheochromocytomas, four adenomas, two Cushing's syndromes, one hematoma, one myolipoma, and one Conn's syndrome. Fourteen of 15 procedures were completed laparoscopically. The average blood loss was 300 ml; the mean operative time was 150 min. In the hands of a laparoscopically experienced surgeon, laparoscopic adrenalectomy is a safe and effective procedure involving minimal morbidity. With the accepted indications for removal of benign adrenal tumors, laparoscopic adrenalectomy is our therapy of choice.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

Soluble CD44 variants in the serum of patients with urological malignancies.

In patients with malignant diseases, characteristic alterations in the expression of CD44 protein and their variants were found. For the present study, the serum concentrations of the standard isoform CD44 std and the two variant isoforms CD44 v5 amd CD44 v6 were measured by ELISA in patients with prostate cancer (n = 49), benign prostatic hyperplasia (n = 30), renal cell carcinoma (n = 31) and bladder cancer (n = 29). The data were compared with the results of 30 healthy men and 30 healthy women. The sCD44 v5 concentrations in patients with prostate cancer (p < 0.01), benign prostatic hyperplasia (p < 0.01) and men with renal cell cancer (p < 0.01) were significantly lower than those measured in the male control group. The sCD44 v5 concentrations observed in male patients with bladder cancer were lower than in the male control group (p < 0.05). Only in one group the concentration of sCD44 std differed significantly from the others. The sCD44 std concentration in male patients with renal cell cancer was significantly lower than in the male control group (p < 0.01). Other significant differences were not found. In contrast to results observed in other carcinomas, the determination of soluble CD44 proteins in serum cannot be recommended as a marker for urological malignancies.

Adult↗