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Query: UMLS:C1519176 (PSA)
 5,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The usefulness of prostate specific antigen to predict final pathological stage was studied in 178 consecutive patients. Prostate specific antigen was determined preoperatively in all patients by a monoclonal immunoradiometric assay. All pathological specimens were examined for capsular penetration, seminal vesicle involvement and lymph node involvement. Prostate specific antigen correlated directly with capsular penetration (p less than 0.002), seminal vesicle involvement (p less than 0.02) and lymph node involvement (p less than 0.05). However the diagnostic accuracy of an elevated serum antigen level on an individual basis was only 55 per cent for capsular penetration and 50 per cent for seminal vesicle involvement and lymph node involvement. With a log-linear regression model, the half-life of prostate specific antigen was calculated to be 3.15 +/- 0.09 days. From the equation PSA (t) equals PSA (2) e[-0.2197(t-2)], prostate specific antigen can be used to detect residual cancer on day t in the immediate postoperative period. With respect to long-term followup, 127 patients have been monitored for longer than 2 months postoperatively with prostate specific antigen (mean followup 2 years, range 2 months to 8.6 years). Of the 101 patients who had favorable pathological findings at operation (organ-confined cancer or capsular penetration only) 92 (91 per cent) had a followup antigen concentration in the female range (0.0 to 0.2 ng. per ml.), whereas only 5 of 26 men (19 per cent) with either seminal vesicle involvement or lymph node involvement had an antigen value that was less than 0.2 ng. per ml. All patients with a documented clinical recurrence (8 of 127, 6 per cent) had an elevated followup serum prostate specific antigen concentration. These findings suggest that preoperative levels of prostate specific antigen are not sufficiently reliable to predict final pathological stage on an individual basis in patients with early prostatic cancer, and that the antigen is a sensitive tumor marker for the detection of residual disease after radical prostatectomy and subsequent recurrence of tumor on long-term followup.
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PMID:Prostate specific antigen in the preoperative and postoperative evaluation of localized prostatic cancer treated with radical prostatectomy. 245 Oct 37

Prostate specific antigen has become an important adjunct to the digital rectal examination in screening for prostate cancer. The clinician should be familiar with interpretation of this test. Many men with BPH have elevated serum PSA concentrations; however, the majority of these men will have other pathologic processes such as occult cancer, PIN, or acute inflammation that may account for the elevations in serum PSA. Certainly, serial increases in serum PSA should increase concern that occult carcinoma is present. Patients with PIN may also have elevated PSA concentrations. When PIN is associated with elevated PSA, a high incidence of invasive carcinoma is noted on subsequent biopsy. Further investigation into the associations will further refine the clinical utility of this powerful tumor marker.
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PMID:PSA in benign prostatic hyperplasia and prostatic intraepithelial neoplasia. 750 69

Prostate specific antigen is an abundant prostate-derived serine protease in the seminal fluid. Low concentrations of the protein are normally released into blood, but above normal concentrations are frequently detected in prostate disease. The PSA-ACT complex is the predominant molecular form of serum PSA (up to approximately 95%) although complex formation is slow between the purified proteins in vitro. A free, noncomplexed form of PSA constitutes a minor fraction of the serum PSA, although serum ACT occurs in large molar excess. The free, noncomplexed form of serum PSA is reported to constitute a significantly smaller proportion of the PSA in untreated prostate cancer than in BPH. The molecular basis for this finding is unclear, but measurements of the proportion of the free form of serum PSA or the proportion of serum PSA-ACT may facilitate discrimination between prostate cancer and BPH.
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PMID:Significance of different molecular forms of serum PSA. The free, noncomplexed form of PSA versus that complexed to alpha 1-antichymotrypsin. 750 76

As part of the search for alternatives to transurethral resection of the prostate (TURP) attention has (re)turned to laser methods. We describe our experience with the currently available endoscopic beam deflection devices, particularly the Prolase II. 25 patients, generally with medical reasons to avoid TURP, and with proven bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPH) underwent prostatic laser coagulation. Average age was 72 years (range 57-84), mean prostatic size by transrectal ultrasound (TRUS) was 48 g (15-100), average pretreatment peak flow rate (FR) was 7.6 ml/s (4.56-12.4). All patients were markedly symptomatic. Patients underwent clinical examination, Prostate specific antigen assay (PSA = 3.75, range 0.1-10.2), and TRUS preoperatively to exclude prostate cancer. After cystoscopic assessment the prostate was lasered according to the device manufacturers recommendations and clinical experience. A suprapubic catheter (SPC) and urethral catheters were inserted, the urethral for 24 hours. If voiding was satisfactory the SPC was removed after 24-48 hrs. Alternatively the patient was discharged and assessed at weekly intervals for SPC removal. Mean duration of SPC drainage was 11 days. Total mean impatient stay was 4.5 days (2-13) during a mean of 2 admissions. Blood loss was minimal and there were no other significant complications. At a minimum follow up of 3 months mean peak FR was 15.3 ml/s (9-31). Symptom scores (IPSS) fell from a mean of 21 to 10 by 3 months after treatment. There was an initial period of irritability for up to 12 weeks but symptomatic improvement was noted in all.
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PMID:[Therapy by endoscopic laser for prostatic obstruction]. 751 89

Prostate cancer is increasing in incidence, particularly because of the control of competing causes of death and the lengthening life span of western men. Screening and early detection initiatives among symptom free men show that the disease can be detected at earlier stages when hope for cure is reasonable. Prostate specific antigen is the most useful marker for prostate cancer. Analytical methods to improve its sensitivity and specificity include PSA density, age specific PSA reference ranges and PSA velocity or the rate of change in PSA. Older paradigms of the natural history of prostate cancer have been heavily influenced by characteristics of clinical disease. However, improved detection of the disease through better diagnostic tools and heightened public awareness may be changing the dynamics of the disease. The prevalence of advanced disease is falling, and more knowledge is accumulating on the identification of clinically significant disease. The most appropriate definition of clinically significant disease today must be based on a new paradigm, one that can build on but not be bound by older models.
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PMID:Screening strategies: a clinical perspective. 754 65

Prostate specific antigen was, until recently, thought to be a highly specific biochemical marker of prostatic epithelial cells. Using highly sensitive techniques, we have recently found that PSA is present in 30-40% of breast tumors and at a lower percentage in other tumors including lung, colon, ovary, liver, kidney, adrenal and parotid tumors. Others have found PSA in skin and salivary gland tumors and in normal endometrium. We found PSA in normal breast, milk of lactating women and in amniotic fluid. The physiological role of PSA in these tissues and tumors is currently unknown. It appears that PSA is either a growth factor or a growth factor regulator and that it may play a role in fetal development. A substrate for PSA in these tissues has not as yet been identified.
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PMID:New diagnostic applications and physiological functions of prostate specific antigen. 754 79

Prostate specific antigen was, until recently, thought to be a highly specific biochemical marker of prostatic epithelial cells which is not produced by any female tissue. We have used immunological and molecular techniques to demonstrate the presence of PSA protein or mRNA in various non-prostatic tissues. We have recently found that PSA is present in 30-40% of breast tumors and at a lower percentage in other tumors including lung, colon, ovary, liver, kidney, adrenal and paroria tumors. Others have found PSA in skin and salivary gland tumors and in normal endometrium. We found PSA in the normal breast, the milk of lactating women, breast discharge fluid and in amniotic fluid. We developed a tissue culture system that reproduces the phenomenon of PSA production by breast tumors. Using this system, we showed that PSA regulation is under the control of steroid hormones and their receptors. PSA is produced by normal, hyperplastic and malignant breast tissue and is present in all breast secretions and some other tumors. The physiological role of PSA in these tissues, fluids and tumors is currently unknown. A substrate for PSA in these tissues has not as yet been identified.
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PMID:Prostate specific antigen--new applications in breast and other cancers. 904 23

Prostate specific antigen, specific organ and tissue marker, is a glycoprotein present in serum in different molecular forms, i.e. not protein bound and bound to proteins (PSA-ACT and PSA-AMG). The total PSA is expressed by the sum of the non protein bound value (free-PSA) and PSA-ACT. The aim of our study was to evaluate the hypothesis that measurement of free/total PSA ratio may be helpful in the differential diagnosis of prostatic pathology. Our study was conducted on 350 patients, to whom the total-PSA, free-PSA and f/t PSA had been performed; 250 patients showed a total PSA between 2.5 and 10 ng/ml and 185 of them had symptoms of bladder out-flow obstruction. In all of the 250 patients digital rectal examination, transrectal ultrasound and prostatic biopsy were performed. 100 patients were controls. The cut-off to differentiate between benign and malignant prostatic disease was 16%. The pathologic diagnosis was related to the f/t PSA ratio, and in particular those patients with a f/t PSA lower than 16% were expected to be prostatic carcinoma, while those with a f/t PSA higher than 16% were expected to be benign prostatic hypertrophy. The diagnostic accuracy of the ratio was calculated, and it was observed that it was 88.65% in the diagnosis of benign prostatic hypertrophy, while in the diagnosis of prostatic carcinoma it was 84.5%. We can therefore assume that f/t PSA can add useful information on prostatic pathology, eventually sparing unnecessary prostatic biopsies.
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PMID:[Diagnostic efficacy of free SPA/total PSA ratio in the diagnosis of prostatic carcinoma]. 918 32

Prostate specific antigen (uPSA) was purified to homogeneity from human urine using SuperQ-Toyopearl, Sulfate-Cellulofine, Phenyl-Toyopearl, CM-Sepharose, anti-urokinase IgG Sepharose and Sephadex G-100. The purified uPSA gave a major band at 32.9 kDa on SDS-PAGE under the reduced condition. However, it shows multiple bands on native PAGE. Substrate specificity of purified uPSA is identical with that of PSA from human seminal plasma and uPSA shows the kallikrein and chymotrypsin-like activities. On the analysis of N-terminal amino acid, two amino acid residues at N-terminal position of uPSA were detected and other amino acid sequence of uPSA was identical with that of sPSA. In addition, we isolated the multiple components of uPSA using anion-exchange chromatography. They were almost the same in amino acid composition and N-terminal amino acid sequences and showed differences in lectin-blotting pattern.
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PMID:Purification and characterization of prostate specific antigen from human urine. 936 70

Prostate specific antigen is a highly specific marker of prostatic tissue. Recent studies have shown, that it is present in several other human tissues, tumors and fluids. PSA has been identified as a serine protease and member of the kallikrein family of enzymes. In our study PSA concentration was measured in 97 cytosols of breast cancer tissues and 14 samples, prepared from human endometrium. Cytosols were analysed also for steroid hormone receptors, EGF-receptor, Cathepsin D and pS-2 protein. PSA was found in 84.5% of breast cancer tissues and in 12 endometrium samples. High concentration of PSA were associated with high pS-2 protein levels. No correlation was found between the concentration of steroid hormone receptors and PSA in our material. The results suggest, that PSA in cytosol of human breast cancer and endometrial tissues may be an additional new prognostic indicator.
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PMID:[Determination of prostate-specific antigen (PSA) in cytosol of breast tumors and human endometrium--new diagnostic approaches]. 961 May 20


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