Pettersson et a!. recently reported that prostate-specific antigen (PSA) corn-plexed to a1-antichymotrypsin (PSA-ACT) is unstable in aqueous solutions [1]. Recognizing the usefulness of PSA-ACT calibrators, given that most of the PSA in male serum is in the complexed form, they pointed out that establishment of optimal conditions for preparation and storage of PSA-AGT complexes to prevent disso...

BACKGROUND The total prostate-specific antigen (t-PSA) in serum measured by PSA assays represents the sum of free (f-PSA) and PSA complexed with alpha 1-antichymotrypsin. The f-PSA/t-PSA (F/T) ratio in prostate cancer (PCA) patients is lower than in patients suffering from benign prostatic hyperplasia (BPH). This review summarizes the current literature on the clinical relevance of measurement ...

Prostate-specific antigen (PSA) has been used for prostate cancer detection since 1994. PSA testing has revolutionized our ability to diagnose, treat, and follow-up patients. In the last two decades, PSA screening has led to a substantial increase in the incidence of prostate cancer (PC). This increased detection caused the incidence of advanced-stage disease to decrease at a dramatic rate, and...

BACKGROUND Heterogeneity among the various molecular forms of prostate-specific antigen (PSA) has not been well characterized, despite the critical importance of PSA in the detection of prostate cancer. The purpose of this study was to examine PSA heterogeneity in cancerous and noncancerous materials by extensive and systematic protein analysis. METHODS A catalog of molecular forms of PSA was...

Prostate-specific antigen (PSA) is an important marker for the diagnosis and management of prostate cancer. Free PSA has been shown to be more extensively cleaved in sera from benign prostatic hyperplasia patients than in sera from prostate cancer patients. Moreover, the presence of enzymatically activatable PSA was characterized previously in sera from patients with prostate cancer by the use ...

P antigen (PSA) is a serine protease produced by the prostate gland at very high concentrations. PSA is secreted into the seminal plasma in high concentrations (0.5 to 5 g/L), where it plays a role in semen liquefaction. The retrograde release of PSA into the bloodstream is a rare event in young, healthy men. It occurs with a frequency of less than one PSA molecule per million secreted PSA mole...

PSA measurements are used to assess the risk for prostate cancer. PSA range and PSA kinetics such as PSA velocity have been correlated with increased cancer detection and assist the clinician in deciding when prostate biopsy should be performed. Our aim is to evaluate the use of a novel, maximum likelihood estimation prostate specific antigen (MLE-PSA) model for predicting the probability of pr...

BACKGROUND Different molecular forms of prostate-specific antigen (PSA) have been used to differentiate between benign prostatic hyperplasia and prostate cancer. Detecting PSA bound to endogenous inhibitors such as alpha(1)-antichymotrypsin (ACT) and alpha(2)-macroglobulin (alpha(2)M) is often difficult because of epitope masking or sensitivity problems. Here we report the characterization of f...

We have analyzed matched serum and breast cyst fluid samples for total PSA from 148 patients with fibrocystic breast disease. We have also determined the molecular forms of PSA (free PSA and PSA bound to alpha1-antichymotrypsin) in 78 breast cyst fluid samples. We found that total PSA can be detected in all cyst fluids and in about 75% of female sera. The median total PSA concentration in breas...