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N Wehner

Publications and source records attributed to N Wehner.

6 recordsLinked to original sources
PubMed1992

Ultrasensitive radioimmunoassay of prostate-specific antigen.

We describe a modification of the Yang Pros-check radioimmunoassay for prostate-specific antigen (PSA) that increases the analytical sensitivity of the assay approximately threefold (from a working range of 0.3-50 to 0.1-1.2 micrograms/L). It can detect PSA added to zero-concentration diluent (bovine serum albumin solution) at 0.10 microgram/L or added to zero-concentration control female serum at 0.20 microgram/L (P less than 0.05). In 26 patients tested after cystoprostatectomy for bladder cancer (who had normal prostates without cancer on histologic examination), PSA values by this ultrasensitive assay were all less than 0.10 microgram/L. Therefore, we propose this value as the upper limit of the 95% reference interval. In a retrospective study of two patients who developed recurrent prostate cancer, serum PSA values increased above the 0.1 microgram/L detection limit 175 and 581 days before increasing above the 0.3 microgram/L detection limit of the standard Yang assay. This ultrasensitive radioimmunoassay of PSA should prove more useful than current methods for detecting early recurrence of prostate cancer.

Antigens, Neoplasm↗
PubMed1990

Comparison of a polyclonal and monoclonal immunoassay for PSA: need for an international antigen standard.

Two leading commercial immunoassays for prostate specific antigen (the Yang Laboratories polyclonal radioimmunoassay and the Hybritech two-site monoclonal radioimmunometric assay) were compared using independently purified antigen as the calibrator. The Yang polyclonal assay yielded values from 1.4 to 1.9 times higher than the Hybritech monoclonal assay on the same sample, similar to results of previous investigators. When an independent prostate specific antigen calibrator was substituted for the respective kit calibrators, both assays yielded essentially identical results, thereby confirming that differences in assay values arise from differences in the assigned values of the kit calibrators. Otherwise, both assays had similar responses in the high and low range. Recovery studies of prostate specific antigen in various diluents demonstrated that antigen recovery was lowest in diluents with the highest protein content. We conclude that the kit manufacturers have assigned different values to their antigen calibrators. Sample values between the assays can be compared by use of an appropriate conversion table. Differences in their recommended ranges of normal for prostate specific antigen in male serum (zero to 2.5 ng./ml. for the Yang assay and zero to 4.0 ng./ml. for the Hybritech assay) reflect two factors: a difference in assigned calibrator values and differences in the selection of the "normal" population of men used to define the normal range of values. We urge adoption of an international standard calibrator for prostate specific antigen as a means to correct these differences.

Antibodies, Monoclonal↗
PubMed1976

Prostatic antibacterial factor. Identity and significance.

Normal human prostatic fluid possesses pronounced antibacterial activity. This activity is absent or markedly diminished in the fluid of men with chronic bacterial prostatitis. Ion-probe and mass spectrographic analysis of this antibacterial factor has shown it to be a zinc salt. Prostatic fluid zinc levels in 15 men with chronic bacterial prostatitis averaged 50 mug. per milliliter (range 0 to 139 mug. per milliliter). The zinc level in the expressed prostate secretion (EPS) of 49 control men averaged 448 mug. per milliliter (range 150 to 1,000 mug. per milliliter). There was no overlap in the range of zinc values between the two groups. The decrease in EPS zinc concentration in the patient population was not secondary to a decreased serum zinc level. Exogenous zinc given orally did not increase the EPS zinc level. The decrease in EPS zinc was not limited to infected prostatic fluid cultures and may precede the entry of bacteria into the prostate. The data presented suggest that zinc may serve as an in vivo defense mechanism against prostatic invasion and subsequent urinary tract infections in men.

Adult↗
PubMed1975

Urinary polyamine levels in the diagnosis of carcinoma of the prostate.

Urinary excretion of the basic polyamine, spermidine, was significantly elevated in patients with prostatic carcinoma as compared to a control group of patients, Of 44 urine specimens from patients with prostatic malignancy 31 had spermidine levels more than 2 mg. per 24 hours, while only 3 of 13 urine specimens from the control groups had levels in excess of this value. The increase in spermidine appeared to be correlated with the histologic grading of the tumor, that is 30 of 34 specimens from patients with grade II, III or IV carcinoma had excessive spermidine excretion and only 1 of 10 urine specimens from patients with grade I tumors had similiar spermidine elevations. High spermidine levles were found in tumors localized to the prostate and in 7 of 8 patients with negative pelvic and para-aortic lymph node biopsies. This study raises the possibility that urinary spermidine determinations may aid in the development of a biochemical screening test for prostatic neoplasms.

Aged↗