Biomedical subjects

D Nagel

Publications and source records attributed to D Nagel.

129 records · Page 8Linked to original sources

PubMedDate not supplied

Total and free PSA: a methodical and clinical evaluation of five assays.

UNLABELLED: We studied the methodical and clinical relevance of five determination assays for free PSA (f-PSA) in addition to the corresponding total PSA antigen (t-PSA). METHODS: Both the total PSA- and free-PSA-values of frozen sera obtained pretherapeutically from 80 patients with carcinoma (PC) and 171 patients with benign hyperplasia of the prostate (BPH) were analysed by means of Enzymun-Test PSA/BM, PSA-RIACT/ CIS, CanAg PSA EIA/ Dia, Tandem-E PSA/Hyb, PSA IRMA/ IBL and Enzymun-Test PSA free/BM, F PSA-RIACT/CIS, CanAg Anti Free PSA/Dia, Tandem-R free PSA/Hyb, FREE PSA IRMA/IBL. RESULTS: The coefficient of correlation between Hybritech PSA assay and the other assays was determined in patients with benign and malignant prostatic diseases. There was a strong overall correlation with all assays measuring total or free PSA, respectively. A satisfying correlation is also shown using a limited scale up to 50 ng/mL for total PSA and 5 ng/mL for free PSA. At 95% specificity sensitivities of total PSA between 40% and 50% of the ratio (Q) = free PSA/total PSA between 4% and 28% were calculated. In a second step only patients with total PSA values below the cutoff level of 16.5 [micrograms/l] (BM), 13.9 [micrograms/l] (CIS), 14.7 [micrograms/l] (Dia), 15.7 [micrograms/l] (Hyb) and 16.8 [micrograms/l] (IBL) were considered. Using the BM assays, of these patients 9 of 162 with BPH and 14 of 47 with PC [CIS: 14 of 162 with BPH and 4 of 48 with PC/Dia: 13 of 162 with BPH and 11 of 48 with PC/Hyb: 6 of 156 with BPH (missing values = 6) and 11 of 40 with PC/IBL: 11 of 160 with BPH (missing values = 1) and 13 of 33 with PC (missing values = 2)] were below the ratio Q = free PSA/total PSA. Considering both steps (total PSA and Q) using the BM assay 47 patlents with PC were detected correctly and 18 patients with BPH would have been biopsied unnecessarily (positive biopsy rate = pos. br.: 72%) [CIS: 38 patients with PC and 23 patients with BPH (pos. br.: 62%)/Dia: 43 patients with PC and 22 patients with BPH (pos. br.: 66%)/Hyb: 51 patients with PC and 15 patients with BPH (pos. br.: 77%)/IBL: 46 patients with PC and 20 patients with BPH (pos. br.: 70%)] CONCLUSIONS: High total PSA levels of all assays are a very good indicator for the presence of prostate cancer. There is still concern to improve the differentiation between BPH and PC, when an intermediate or low value (< 95% specificity) is observed. The determination of Q is only useful in this range and it might be helpful for the clinicians decision to apply or avoid biopsy.

Antibodies, Monoclonal↗

PubMedDate not supplied

Alpha 1-antichymotrypsin-PSA (ACT-PSA): a useful marker in the differential diagnosis of benign hyperplasia and cancer of the prostate?

UNLABELLED: This study examined the clinical relevance of the determination of alpha 1-antichymotrypsin complexed PSA (ACT-PSA) in addition to total PSA antigen (t-PSA). PATIENTS AND METHODS: Both total PSA- and ACT-PSA-values of frozen sera obtained pretherapeutically from 93 patients with carcinoma (PC) and 132 patients with benign hyperplasia of the prostate (BPH) were analyzed by means of PSA sandwich-ELISA (Dianova GmbH) and ACT-PSA sandwich-ELISA (Dianova GmbH). RESULTS: At 95% specificity (true negative test results), a cutoff value of 18.9 [micrograms/L] was obtained for total PSA (7 patients with BPH [5%] were above this value). For this cutoff value we calculated a sensitivity (true positive test results) of 41%. Using the same criteria for the ratio Q = ACT-PSA: t-PSA (percentage of ACT-PSA) a cutoff of 6.0 was found again at a specificity of 95%. In a second step only patients with total PSA values below the cutoff level of 18.9 [micrograms/L]) were considered. Out of these patients 119 of 125 with BPH and 3 of 54 with PC were below the above mentioned ratio (Q = 6.0). Considering both steps (total PSA and Q) 42 patients with PC were detected correctly and 15 patients with BPH would have been biopsied unnecessarily. CONCLUSION: High total PSA levels are a very good indicator for the presence of prostate cancer. There is still concern to improve the differentiation of the diagnosis between BPH and PC, when an intermediate or low value (< or = 95% specificity) is observed. The determination of Q = ACT-PSA: t-PSA is not to be recommended because it might not be helpful for the clinicians decision to perform biopsy.

Diagnosis, Differential↗

PubMedDate not supplied

Alkaline phosphatase isoenzymes in detection and follow up of breast cancer metastases.

Alkaline phosphatase isoenzymes in bone and liver metastases of breast cancer were determined in 637 patients and during follow up in 116 patients, by agarose gel electrophoresis. The activity of total alkaline phosphatase, gamma glutamyl transferase, CEA and CA 15-3 was also determined. The sensitivity of bone alkaline phosphatase in bone metastases detection was 39%, of electrophoresis (total alkaline phosphatase and specific isoenzymes) 48% and of enzymes and tumor markers together 85% (n = 62). For liver metastases gamma glutamyl transferase had the best sensitivity (100%, n = 19). Even though positive predictive value was only 6%, the sensitivity of liver alkaline phosphatase was 58% and of electrophoresis 94%. The determination of alkaline phosphatase isoenzymes is a non-invasive, in-expensive, reproductable and rapid method to detect progressive disease in breast cancer, especially in combination with the tumor markers CA 15-3 and CEA.

Alkaline Phosphatase↗