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E J Pontes

Publications and source records attributed to E J Pontes.

24 records · Page 2Linked to original sources

Human prostatic acid phosphatases: I. Isolation.

A new purification procedure is described for the human prostatic acid phosphatase. The procedure included carboxy-methyl-Sephadex and Concanavalin A affinity column chromatography. The purified enzyme has a high specific enzyme activity and is free from any extraneous proteins judging from immunochemical criteria and biochemical criteria such as SDS-polyacrylamide gel electrophoresis. The purified enyzme produced a monospecific anti-PAP antisera in animals and this anti-PAP antibody did not cross-react with other human acid phosphatases.

Acid Phosphatase↗

Human prostatic acid phosphatases: II. A double--antibody radioimmunoassay.

A double-antibody radioimmunoassay method for prostate-specific acid phosphatase (PAP) is presented. Experimental details are outlined to assess the reproducibility and reliability of the method under assay conditions. The upper limit of the serum PAP levels in the present assay was set at 2.4 ng/100 microliter by 162 determinations of normal serum samples. The serum PAP levels of patients with nonprostatic malignant tumors fell in the normal range, whereas the levels higher than 4.0 ng/100 microliter were found in patients with prostatic carcinoma.

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Human prostatic acid phosphatases: III. Counterimmunoelectrophoresis for rapid identification.

When serial dilution of standard prostatic acid phosphatases (PAP) was reacted with constant amounts of anti-PAP serum by counterimmunoelectrophoresis (CIEP), the detection end point of enzyme concentration was 0.25 ng in a 10 microliter sample volume. The PAP concentrations in unknowns can be quantitated by comparing the dilution end points of reference PAP with the testing samples. Serum PAP levels were determined by a radioimmunoassay (RIA) and CIEP using normal male and female sera and serum samples from patients with prostatic cancer and nonprostatic tumors. An excellent correlation was observed between the two assay results. According to RIA data, the concentration of PAP higher than 0.4 ng per 10 microliter (or 4.0 ng per 100 microliter) signify the elevation of serum or bone marrow PAP level beyond normal range (normal value 1.6 +/- 0.8 ng/100 microliter). Thus, the CIEP assay will be a simple and reliable screening method for the serum PAP levels in the clinical diagnosis of prostatic cancer.

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Expression of human prostatic acid phosphatase in a pancreatic islet cell carcinoma.

The immunologic specificity of human prostatic acidphosphatase has been established by several previous investigations as well as in this study. An apparent exception to this specificity was observed--a case of pancreatic islet cell carcinoma metastasized to the liver produced acid phosphatase that was immunologically indistinguishable from the prostatic acid phosphatase. In this case, the possibility of prostatic involvement was convincingly ruled out by clinical follow-ups and by postmortem pathologic studies. Highly purified prostatic acid phosphatase and this tumor acid phosphatase exhibited very similar Km values and identical molecular weights. Immunochemical analysis of the two enzymes using antiprostatic acid phosphatase sera showed that enzymes are antigenically identical. The implications of our observation are discussed in relation to clinical application of immunoassays for prostatic phosphatase in the future and to the molecular basis of human acid phosphatase polymorphism.

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Immunochemical studies of prostatic acid phosphatase.

Immunologic specificity of the prostatic acid phosphatase (PAP) and the kinetics of the PAP-anti-PAP antibody interactions were studied in detail. Antigenic identity of electrophoretic isozymes of PAP was established in this study. Counterimmunoelectrophoretic assay, radioimmunoassay, and immunofluorescence technique were developed to detect PAP and PAP-synthesizing cells. These techniques were applied to the determination of serum PAP levels and to the identification of metastatic prostate cancer cells in biopsies.

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[Survival in stage T2-T3A bladder cancer treated with radical cystectomy].

OBJECTIVE: The optimal treatment for patients with localized muscle-infiltrating urothelial carcinoma (Jewett stage B or T2-T3a of the TNM classification, UICC 1992) continues to be a controversy. The present study analyzed the survival rate in patients with stage T2-T3a bladder cancer who had been treated by radical cystectomy. METHODS: The records of 50 patients with T2-T3a NO tumor, submitted to pelvic lymphadenectomy and radical cystoprostatectomy, were reviewed to determine the prognosis in this group of patients. Seventeen patients (34%) received three courses of systemic chemotherapy (CMV) prior to cystectomy. RESULTS: The overall 5-year survival rate was 73%; 76% for those with T2 (n = 30) and 67% for those with T3a (n = 20) (log-rank, p = 0.27). No statistically significant differences were observed for age (less than or over 65 years), tumor growth pattern (papillary or flat), tumor size (less or greater than 5 cms) or treatment (with or without induction CMV). However, patients with G1-2 tumor had a better survival rate (94% at 5 years) than those with G3 tumor (51%), a difference with statistical significance (log-rank, p = 0.047). The Cox regression analysis showed no independent variable of prognostic significance. CONCLUSION: Muscle-infiltrating urothelial carcinoma is highly curable by radical surgery. Some authors believe it is unnecessary to distinguish T2-T3a lesions; therefore a critical review of the TNM classification appears to be warranted. We are unable to distinguish patients with a better prognosis that might benefit from less aggressive therapeutic options. Similarly, the therapeutic benefits of induction chemotherapy prior to cystectomy in patients with stage T2-T3a tumor could not be demonstrated.

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