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Biomedical subjects

C D Cheli

Publications and source records attributed to C D Cheli.

9 recordsLinked to original sources
PubMed2006

Prostate specific antigen isoforms and human glandular kallikrein 2--which offers the best screening performance in a predominantly black population?

PURPOSE: Free prostate specific antigen, complexed PSA and human glandular kallikrein 2 have independently been tested against the gold standard of total PSA for prostate cancer screening in largely white populations. With the incidence of prostate cancer much higher in black men, we sought to evaluate these markers simultaneously in a predominantly black population. MATERIALS AND METHODS: A total of 138 men, of whom 108 were black, underwent ultrasound guided biopsy of the prostate for tPSA levels greater than 2.5 ng/ml or an abnormal digital rectal examination. Sera were drawn before biopsy and analyzed for tPSA, fPSA, cPSA and hK2 concentrations using standard methods (hK2 assay is for research use only, not for use in diagnostic procedures). The areas under the receiver operator characteristic curves were determined for each marker as well as biomarker combinations. Additionally, each parameter's specificity, positive and negative predictive values, and theoretical screening efficiency were assessed at or above the 95% sensitivity level. RESULTS: A total of 43 (31.1%) men had prostate cancer by biopsy. While the AUC for %fPSA was statistically the highest (0.822, p <0.001), cPSA offered the highest specificity (31.6%) and positive predictive power (31.7%) of any of the tested biomarkers at comparable sensitivity (greater than 95%). The calculated efficiency of cPSA (51.4%) was also higher than the other markers. Nearly 20% of biopsies would be avoided using cPSA vs standard tPSA screening methods. CONCLUSIONS: Comparing the major PSA isoforms and hK2, cPSA alone appears to offer superior diagnostic discrimination for cancer detection in a predominantly black population.

Black or African American↗
PubMed2003

Complexed PSA performance for prostate cancer detection in an African-American population.

OBJECTIVES: Complexed prostate-specific antigen (cPSA) has been shown to improve the differentiation of benign and malignant disease compared with total PSA (tPSA) in studies evaluating predominantly white populations of men. We sought to evaluate the diagnostic performance of cPSA relative to tPSA in a population of African-American men. METHODS: Consecutive African-American men scheduled for prostate biopsy were enrolled prospectively at the Louisiana State University Medical Center, New Orleans. Serum was collected before the biopsy procedure and tested with the Immuno 1 tPSA and cPSA methods. Receiver operating characteristic curve analysis was performed and the area under the curve was calculated for tPSA and cPSA. RESULTS: A total of 156 patients were evaluated, 51 (32.7%) of whom were diagnosed with prostate cancer. The median PSA value for men with prostate cancer was 4.96 ng/mL and for those with benign disease was 3.93 ng/mL. The receiver operating characteristic analysis indicated that the area under the curve for cPSA (0.679) was statistically greater than that achieved for tPSA (0.642, P = 0.004). Using cutoff values for cPSA of 2.3 ng/mL and for tPSA of 2.85 ng/mL provided a specificity of 31.4% and 26.7%, respectively, at a sensitivity for prostate cancer detection of 95%. This was not statistically significant (P = 0.18). CONCLUSIONS: cPSA offers modest improvement in prostate cancer detection compared with tPSA in African-American men, but not at the clinically relevant 95% sensitivity level. Additional work is needed to improve prostate cancer detection in this high-risk cohort of patients.

Adenocarcinoma↗
PubMed2000

Complexed prostate specific antigen provides significant enhancement of specificity compared with total prostate specific antigen for detecting prostate cancer.

PURPOSE: Determining serum total prostate specific antigen (PSA) has proved to be a valuable diagnostic aid for detecting prostatic carcinoma, although the lack of specificity has limited its usefulness. Studies indicate that the use of percent free PSA would improve specificity while maintaining sensitivity. Since complexed PSA represents the major proportion of measurable PSA in serum, we determined whether it represents a single test alternative to the use of percent free PSA for the early detection of prostate cancer. MATERIALS AND METHODS: Archival serum was obtained from 385 men with no evidence of malignancy on biopsy and 272 with biopsy confirmed prostate cancer. We determined the concentration and proportion of total, complexed and free PSA. RESULTS: Receiver operating characteristics analysis using total PSA results from all samples (range 0.32 to 117 ng./ml.) indicated that the areas under the curve for complexed PSA alone as well as the free-to-total and complexed-to-total PSA ratios were similar and significantly greater than those for total PSA alone. Within the range of 85% to 95% sensitivity receiver operating characteristics analysis revealed that the specificity of complexed PSA was higher than that of total PSA and equivalent to that of the free-to-total PSA ratio. We noted a similar improvement in specificity in the 4 to 10 ng./ml. total PSA range. Using published cutoff values for complexed, total and percent free PSA when total PSA was in the 4 to 10 ng./ml. range the sensitivity and specificity of complexed and percent free PSA were similar. Within the 4 to 10 ng./ml. total PSA range the population of patients with no evidence of malignancy and complexed PSA below the upper limit was different with respect to total PSA from that with no evidence of malignancy and free PSA greater than 25%. CONCLUSIONS: The measurement of complexed PSA represents an alternative to the use of percent free PSA, although the patient populations identified by the 2 tests are different.

Humans↗
PubMed1999

Measurement of four tumor marker antigens in the sera of pregnant women.

We sought to determine the maternal serum levels of four tumor-associated antigens during the three trimesters of pregnancy in healthy women. CEA, CA 228, CA 15-3, and Her2/neu oncogene product p105 assay values were determined for 90 healthy pregnant women during the three trimesters of pregnancy at five participating evaluation sites. Results were compared to means and cut-off values determined for healthy nonpregnant women. Differences in assay values in the 1st and 3rd trimester were analyzed for statistical significance (Student's t-test). CEA, CA 228 and CA 15-3 assay values in general were found to be within the normal range. CA 15-3 and Her2/neu p105 serum assay values were above the cut-off (3.3% and 8.2%, respectively) and were significantly elevated in the 3rd trimester as compared to the 1st trimester of pregnancy (P < 0.05 and P < 0.001, respectively). CEA and CA 228 may be of potential value in monitoring pregnant women with malignant disease. Normal elevations in 3rd trimester serum Her2/neu p105 and CA 15-3 assay values should be considered when monitoring a pregnant patient with malignant disease.

Adolescent↗
PubMed1998

Multicenter evaluation of the Bayer Immuno I CA 15-3 assay.

We conducted a multicenter evaluation of the analytical and clinical features of the automated Bayer Immuno 1 CA 15-3 assay and compared assay performance to two manual tests. Results of the 10-day imprecision study of the Bayer Immuno 1 assay pooled across four evaluation sites and three lots of reagent produced total CV < or = 4%. Lot-to-lot reproducibility for 26 different lots of reagents and calibrators manufactured over a 2-year period was demonstrated (CV, 1.1%). Results for the Bayer Immuno 1 assay correlated well with the Biomira TRUQUANT BR 27.29 and Centocor CA 15-3 RIAs (r > or = 0.94). The upper limit of the reference interval for the Bayer Immuno 1 assay was 35.9 kilounits/L (35.9 units/mL); values were similar for all methods. Longitudinal monitoring of healthy women yielded assay values with an average CV of 11% and 21% for the Bayer Immuno 1 and Biomira assays, respectively. The Bayer Immuno 1 assay demonstrated the analytical features, intermethod correlation, and long-term performance characteristics that are essential for longitudinal monitoring of breast cancer patients.

Adolescent↗
PubMed1986

Dexamethasone inhibits prostaglandin release from rabbit coronary microvessel endothelium.

The effects of dexamethasone on prostaglandin secretion by cultivated rabbit coronary microvascular endothelial (RCME) cells were investigated. Incubation of RCME cells with dexamethasone resulted in a time- and concentration-dependent decrease in prostaglandin accumulation in the culture media and reduced basal and A23187-stimulated prostaglandin (PG) E2 and 6-keto-PGF1 alpha release. The maximal effects of dexamethasone (50-80% inhibition) were achieved after 16-18 h of incubation with the steroid at a final concentration of 10(-7) M. The effects of dexamethasone treatment were partially reversed 24 h after removal of the steroid from the culture media. Dexamethasone treatment did not reduce arachidonic acid-stimulated prostaglandin synthesis, indicating that the level of inhibition was proximal to that of cyclooxygenase. The inhibitory effects of dexamethasone could be prevented by pretreatment of the RCME cells with actinomycin D or cycloheximide, suggesting a requirement for protein synthesis in the inhibitory action of dexamethasone. Conditioned media from dexamethasone-treated cells contained a factor that inhibited porcine pancreatic phospholipase A2 (PLA2) in vitro. Transfer of conditioned media from dexamethasone-treated cells to untreated cells did not reduce basal or stimulated prostaglandin release; in contrast, a stimulatory action was consistently observed. Adherence of rabbit peripheral polymorphonuclear leukocytes (PMN) to RCME cells was reduced when the leukocytes were pretreated with 10(-7) M dexamethasone (4 h). However, dexamethasone pretreatment of the RCME cells did not significantly effect granulocyte adhesion. Thus coronary microvascular endothelial cell prostaglandin production is regulated by glucocorticoids, and glucocorticoid-pretreated microvascular endothelial cell release an inhibitor of PLA2 activity into the culture media.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1983

Arachidonic acid and prostaglandin endoperoxide metabolism in isolated rabbit and coronary microvessels and isolated and cultivated coronary microvessel endothelial cells.

Isolated microvessels and isolated and cultured microvessel endothelial cells were prepared from rabbit cardiac muscle. Pathways of arachidonic acid metabolism were determined by measurement of exogenous substrate utilization [( 1-14C]arachidonic acid incorporation and release from intact tissue and cells; [1-14C]prostaglandin H2 (PGH2) metabolism by broken cell preparations) and by quantification of endogenous products (immunoreactive 6-keto-prostaglandin F1 alpha (PGF1 alpha) and prostaglandin E (PGE) release) by selective radioimmunoassay. Rabbit coronary microvessels and derived microvascular endothelial cells (RCME cells) synthesized two major products of the cyclooxygenase pathway: 6-keto-PGF1 alpha (hydrolytic product of prostaglandin I2) and PGE2. A reduced glutathione requiring PGH-E isomerase was demonstrated in coronary microvessels and RCME cells, but not in rabbit circumflex coronary artery or aorta. In addition, a minor amount of a compound exhibiting similar characteristics to 6-keto-PGE1 was found to be produced by microvessels and RCME cells. Measurement of endogenously released prostaglandins indicated that under basal and stimulated conditions, PGE release exceeded that of 6-keto-PGF1 alpha. Microvessels and microvessel endothelial cells derived from cardiac muscle of rabbit exhibit pathways of arachidonate metabolism that are different from those of many large blood vessels and derived endothelial cells.

6-Ketoprostaglandin F1 alpha↗
PubMedDate not supplied

Multicenter evaluation of the performance and clinical utility in longitudinal monitoring of the Bayer Immuno 1 complexed PSA assay.

We conducted a multicenter evaluation of the analytical and clinical performance of the automated Bayer Immuno 1 complexed PSA (cPSA) assay, and compared assay performance to the Bayer Immuno 1 PSA assay. We sought to determine whether measurements of cPSA could be of clinical utility in the management of patients with prostate cancer. Results of the 10-day imprecision across three evaluation sites produced total CV < 2.50% and an analytical sensitivity of 0.02 microgram/L. There was an increased trend in clinical sensitivity for prostate cancer with increasing stage of disease (71-86%). Clinical specificity for patients with benign urogenital disease was 74.8%, and for other nonprostate diseases ranged from 91.1-100%. Retrospective serial monitoring of 155 patients with prostate cancer demonstrated concordance of cPSA measurements to clinical status for 97% of the patients analyzed. Results from the clinical studies using the Bayer Immuno 1 cPSA assay were comparable to results obtained with the Bayer Immuno 1 PSA assay. The Bayer Immuno 1 cPSA assay demonstrates analytical performance and clinical effectiveness in the management of prostate cancer patients during the course of disease and therapy.

Adolescent↗