Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C1519176 (PSA)
 5,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study investigated the serum prostate-specific antigen concentration in 100 healthy men (mean age, 26.3 years; range, 20-29 years) with a clinically normal prostate gland. The effect of digital rectal examination and ejaculation on the serum concentration, and the variability of the serum concentration over 1-week and 1-month periods were examined. In the 100 subjects, the serum prostate-specific antigen concentration ranged from less than 0.1-2.6 ng/ml. The mean, median, and mode were 0.68 ng/ml, 0.6 ng/ml, and 0.4 ng/ml, respectively. The 97.5th percentile value was 2.1 ng/ml. The mean and median changes in the serum concentration after digital rectal examination were -0.013 +/- 0.11 ng/ml and 0.0 ng/ml, respectively (P = 0.59 compared with control group). The mean change after ejaculation was 0.05 +/- 0.12 ng/ml, and the median change was 0.0 ng/ml (P = 0.14 compared with control group). Diurnal variation showed minimal change in 16 patients over a 1-week period. The mean change (p.m. value-a.m. value) was 0.003 ng/ml (range, -0.2-0.06 ng/ml). In addition, the serum concentration showed minimal intrapatient variability in 20 patients throughout a 1-month period; the average coefficient of variation (standard deviation/mean) in these subjects was 16.5% (range, 6.4-45.2%). These results indicate that the range in the serum concentration of prostate-specific antigen for healthy men with a clinically normal prostate gland is significantly lower (0.0-2.6 ng/ml) than the currently employed range (0.0-4.0 ng/ml; Tandem-R PSA assay); in addition, digital rectal examination and ejaculation have no significant effect on the serum concentration. Finally, the time of day has little effect, and the variability in the serum concentration of prostate-specific antigen over a 1-week and 1-month interval is minimal.
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PMID:Prostate-specific antigen: establishment of the reference range for the clinically normal prostate gland and the effect of digital rectal examination, ejaculation, and time on serum concentrations. 138 15

We used the method of Rudolph et al. (Clin Chem 1988; 34:2031-8) to find information in the data from correlated determinations of acid phosphatase (PAP, EC 3.1.3.2; DuPont aca) and prostate-specific antigen (PSA, Hybritech). We described there how we assign medical decision limits for two or more correlated variables and convert the database to a binary coded message, allowing separation of a selected disease class with minimum error. The decision point, analogous to a percentile upper limit on the ordered values of each variable in the reference group, satisfies the maximum entropy constraints of reference, producing a minimum entropy for the binary coded patient database. We found maximum entropy decision points at PAP = 0.75 U/L and PSA = 22.8 micrograms/L. Patients with PSA values exceeding 22.8 micrograms/L had no benign prostatic disease except for five patients with benign prostate hyperplasia (BPH) with adjacent colon carcinoma (95.3), BPH with infarction (27.6), BPH (23.4) 28.1), or acute prostatitis (34.6). We consider PSA exceeding 22.8 micrograms/L as indicative of carcinoma of the prostate, stage C or D, in the absence of disconfirming evidence. Another decision value for PSA is 11.3 micrograms/L. This bounds the region between 11.3 and 22.8 micrograms/L, where the frequency of BPH is 1.5 times that for adenocarcinoma. At PSA less than 11.3 micrograms/L there is a high frequency of BPH. PSA concentration is not correlated with prostatic size (mass) or with prostatitis. A metastatic carcinoma is as likely to be nonprostatic as prostatic when the PSA concentration is less than 11.3 micrograms/L.
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PMID:Medically significant concentrations of prostate-specific antigen in serum assessed. 169 92

A quadruple tumor marker serotest assay (neurone-specific enolase, NSE, prostate-specific antigen, PSA, prostatic acid phosphatase, PAP, and carcino-embryonic antigen, CEA) was performed on sera from both 63 patients with untreated prostate cancer and 135 patients treated with orchiectomy, flutamide, diethylstilbestrol (DES), cyproterone acetate (CPA), and Estracyt. In untreated patients with local tumor elevated blood NSE concentrations were found more frequently (10/35, 28.6%) than in untreated subjects with disseminated disease (3/28, 10.7%). Elevated NSE values were measured more frequently in nonresponders to therapy 10/46 (21.7%), than in responders during prostate cancer partial remission (2/89, 2.2%). In none of NSE-positive neoplasms a small cell prostate cancer has been histologically detected. Many of NSE-positive tumors are also closely associated with elevated blood CEA values. The applied anticancer drugs were inefficient in the normalization of neither one from the pair of elevated NSE and CEA concentrations (regardless of the numerical values of the other two markers, PSA and PAP), but their values were found to decline occasionally only after surgical treatment. In patients with raised PSA, PAP, and CEA levels but with a normal NSE value, the application of the same treatment strategies was in the most of subjects sufficient to provoke either temporary or even lasting tumor response to therapy. Hence, it appears that the assessment of the NSE serotest, despite its minimal value in the overall tumor staging and monitoring, might furnish the decision-making step related to the treatment of aggressive prostate cancer with an additional and powerful tool.
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PMID:Investigation on serum neurone-specific enolase in prostate cancer diagnosis and monitoring: comparative study of a multiple tumor marker assay. 171 80

Prostatic acid phosphatase (PAP), prostate-specific antigen (PSA; or gamma-seminoprotein), and beta-microseminoprotein (beta-MSP; PSP94 or beta-inhibin) are the three predominant proteins secreted by the normal human prostate gland. In the epithelium of normal and hyperplastic prostatic acini and ducts PAP, PSA and beta-MSP have an identical immunohistochemical localization. Highly differentiated (grade I) carcinomas contain an almost equal number of PAP-, PSA- and beta-MSP-immunoreactive cells; the incidence of these cells is lower and they display a greater staining variability in the moderately and poorly (grade II-III) differentiated tumours. Especially in poorly differentiated tumours PSA seems to be a more sensitive immunohistochemical marker than PAP or prostatic carcinomas. Moreover, the use of PAP as a marker for prostatic carcinomas is complicated by the reported structural similarities between the prostatic secreted acid phosphatase and lysosomal acid phosphatase occurring in all tissues. The use of beta-MSP as a marker for prostatic carcinomas may be limited by indications of non-prostatic production of this protein.
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PMID:Three predominant prostatic proteins. 172 Feb 87

In 712 patients, mapping of the prostate by six systematic ultrasound-guided core biopsies was performed without major side effects using the "biopyt gun". The histologic findings provided data on patients with normal and those with abnormal prostates on digital rectal examination (DRE). Only 3 of 72 (4%) nonurologic patients with normal prostate-specific antigen (PSA; less than 4 ng/ml) had prostate cancer. In patients with firm prostates on DRE and normal PSA, 13 out of 101 (13%) had prostate cancer. In patients in whom PSA was greater than or equal to 4 ng/ml, 92 of 158 (58%) had prostate cancer. In patients with clinical stage B or C and PSA less than 4 ng/ml, 20/56 (36%) had prostate cancer, compared to 155 of 187 (83%) patients with PSA greater than or equal to 4 ng/ml. Transrectal ultrasound (TRUS) seemed not to be useful in screening for prostate cancer, due to its low specificity of 54%, although in patients with clinical stage B or C TRUS identified 157/175 (90%) patients with prostate cancer. For staging prostate cancer we compared in 103 men with pelvic lymph node dissection the value of digital rectal examination, computerized tomography (CT), magnetic resonance imaging (MRI), PAS, TRUS, and random systematic biopsy for identification of lymph-node-positive patients before radical prostatectomy. CT had a sensitivity of only 7% and a specificity of 96% in detecting lymph nodes, whereas MRI had a sensitivity of 50% and a specificity of 100%.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Diagnosis of localized prostate cancer: screening and preoperative staging]. 172 21

We evaluated the analytical performance of a new monoclonal immunoradiometric assay ("M-PSA") for prostate-specific antigen ("Tandem"; Hybritech Inc.) in comparison with a monoclonal immunoradiometric assay ("M-PAP") for mass measurement of prostatic acid phosphatase ("Tandem") and with a conventional enzyme-activity assay ("E-PAP") for prostatic acid phosphatase (EC 3.1.3.2). For M-PSA, the CVs were 1.3-3.0% within-run and 3.0-4.9% between-run. The minimum detectable mass concentration was 0.10 microgram/L, and linearity extended to 100 micrograms/L. The reference interval for M-PSA in 178 healthy men was 0-2.8 micrograms/L. Serum specimens from men with prostatic disease (primarily prostatic carcinoma and benign prostatic hypertrophy) were assayed by the three methods. Correlation was best between mass measurement (M-PAP) and enzyme activity (E-PAP) for prostatic acid phosphatase (r = 0.958). Results for PSA did not correlate well with those for either M-PAP (r = 0.629) or E-PAP (r = 0.387). PSA was increased in a higher percentage of specimens from men with earlier (clinical stage B) prostatic carcinoma than were results from either assay for PAP.
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PMID:Evaluation of a monoclonal immunoradiometric assay for prostate-specific antigen. 244 7

Human seminal vesicle and prostatic fluids were obtained separately and reconstituted in vitro to test the hypothesis that proteolytic enzymes of prostatic origin would degrade seminal vesicle-specific antigen (SVSA). Using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis to follow the fate of SVSA over time, we found that upon mixing the two secretions, SVSA was converted to forms of intermediate and low molecular weight identical to transformations seen in normal liquefied ejaculates. Diisoproprylfluorophophate, a serine protease inhibitor, prevented this degradation, indicating serine protease involvement in the proteolysis of SVSA. Prostate-specific antigen (PSA; also known as P-30), recently identified as a serine protease, was examined for its ability to mimic the effects of prostatic fluid on SVSA. Purified PSA catalyzed degradation of SVSA to produce proteolytic fragments that comigrated and were immunologically related to SVSA fragments produced by prostatic fluid. Purified PSA in the presence of serine protease inhibitors was unable to degrade SVSA. These results demonstrate that SVSA is a substrate for PSA during human semen liquefaction.
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PMID:Human seminal vesicle-specific antigen is a substrate for prostate-specific antigen (or P-30). 246 Jan 48

Elevated serum prostate-specific antigen secondary to acute bacterial prostatitis occurred in 2 patients. This cause of increased PSA has not been documented previously.
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PMID:Elevated serum prostate-specific antigen due to acute bacterial prostatitis. 169 Sep 38

We studied serum prostate-specific antigen levels in 12 men with benign prostatic hypertrophy treated with a long-acting GnRH analogue, leuprolide, 1 mg (0.2 mL) sc. daily for six months. The average decrease in prostate size measured by ultrasound was 45 percent after six months with concomitant improvement in the obstructive symptoms of prostatism. There was a steady decline in serum PSA levels which paralleled the decrease in prostate size. One patient who discontinued treatment after six months demonstrated both a regrowth of his prostate and a rise in serum PSA levels to pretreatment levels four months post-discontinuation of treatment. We conclude that treatment with a GnRH analogue caused reversible involution of prostatic epithelial cells with parallel effects on serum PSA levels. Consideration of the initial prostate size together with the serum PSA levels can help predict the response to medical castration in men with BPH.
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PMID:Serum prostate-antigen levels in patients with benign prostatic hypertrophy treated with leuprolide. 247 67

Prostate-specific antigen has proven to be a new useful marker for the evaluation of men with prostatic cancer. In addition to its proven value for immunohistochemical staining and for the followup evaluation of men treated with hormonal therapy, the monoclonal immunoradiometric assay for PSA has proven to be a unique, sensitive, and specific marker for the followup evaluation of men who have undergone radical prostatectomy.
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PMID:The value of prostate-specific antigen in the management of localized prostatic cancer. 247 20


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