Biomedical subjects

M K Brawer

Publications and source records attributed to M K Brawer.

137 records · Page 8Linked to original sources

PubMed1987

Analytical and physiological characteristics of prostate-specific antigen and prostatic acid phosphatase in serum compared.

We did a comparative analysis of the physiological and analytical properties of prostate-specific antigen (PSA), acid phosphatase (ACP; EC 3.1.32) activity, and acid phosphatase antigen (PAP) in serum. The PSA assay is sensitive to 0.2 microgram/L and demonstrates good linearity (y = 1.01x + 0.74). The CV was 3.9% at 40 micrograms/L, 8.0% at 3.1 micrograms/L. PSA and PAP are less stable at 4 degrees C than at -20 degrees C. Serum PAP and ACP concentrations showed large intra-individual fluctuations (average CVs of 22% and 24%, respectively), which were not observed with PSA measurements (average CV 6.2%). We saw significant correlation with the magnitude of physiological change when analytes were compared for serially collected split samples [y(PSA) = 0.14x(PAP) + 0.00, r = 0.767], which indicates that a common factor is influencing this variation. The excellent analytical performance, tissue specificity, and small degree of intra-individual variance are characteristics that favor the measurement of PSA in serum for monitoring patients with prostatic cancer.

Acid Phosphatase↗

PubMed1985

Keratin immunoreactivity in the benign and neoplastic human prostate.

Keratin immunoreactivity in the benign and neoplastic human prostate was examined immunohistochemically using two monoclonal antibodies with differing specificities. One of these antibodies stained only the basal cells of the normal and hyperplastic prostatic epithelium, with no reactivity in tumor cells of prostatic adenocarcinoma. The other monoclonal antibody recognized a keratin protein present in all normal and hyperplastic columnar (secretory) epithelial cells, as well as in all cancer cells regardless of degree of tumor differentiation. In addition, the second antibody stained acinar and ductal epithelial cells exhibiting premalignant changes. Our findings indicate that keratin immunoreactivity differs among the epithelial cell populations of the human prostate, probably reflecting expression of different keratin proteins. The distinctive patterns of staining obtained with these two antibodies may assist in distinguishing hyperplastic from neoplastic prostatic epithelium, as well as in the recognition of basal cell hyperplasia, transitional cell metaplasia, and premalignant changes.

Antibodies, Monoclonal↗

PubMed1982

Papillary adenocarcinoma of ureter.

A well-differentiated papillary adenocarcinoma developed in a ureteral stump thirty-six years after nephrectomy and was associated with a combined transitional-epidermoid carcinoma in the urinary bladder. Carcinoma in a ureteral stump is not uncommon and should be suspected in patients with a ureteral stump and hematuria. The very rare adenocarcinoma of the ureter is typically papillary and is associated with urinary tract infection and stones. At present successful treatment requires the early identification and extirpation of the ureteral tumor and consideration of associated cancer elsewhere in the urinary tract.

Adenocarcinoma, Papillary↗

PubMed1980

Mucinous adenocarcinoma probably arising in the renal pelvis and ureter: a case report.

A patient with widely disseminated mucinous adenocarcinoma had polypoid tumors in the left renal pelvis and ureter. While no certain primary site was determined, either clinically or at postmortem examination, microscopic examination of the left renal pelvis and ureter revealed atypical glandular metaplasia adjacent to the tumors and made the upper urinary tract a likely site of origin for the adenocarcinoma.

Adenocarcinoma, Mucinous↗

PubMed1980

Survival of full-thickness skin grafts over avascular defects.

The ability of full-thickness skin grafts to survive over avascular defects has been studied in rabbits. The size of a nonvascularized defect over which take occurs appears to have an absolute limit. If the graft is returned to its bed and an implant is inserted under the graft once it has become vascularized, the graft can be supported solely by the blood supply from the periphery of the graft over an implant of any size.

Animals↗

PubMed1980

Focal fatty change of the liver, a hitherto poorly recognized entity.

Fatty change of the liver is a well-recognized entity associated with many clinical situations. It is a diffuse lesion although it may show centrolobular or periportal accentuation. Focal fatty change, on the other hand, is a rarely recognized and poorly characterized entity. We are presenting 10 cases of this condition. The lesions were discovered incidentally at post mortem examination in patients ranging in ages from 26 mo to 79 yr. The nodules measured up to 4.0 cm in diameter, were predominantly subcapsular in location, and the majority occurred in livers with minimal diffuse steatosis. At autopsy some had been confused with abscesses and metastases. The underlying disease processes and therapy were examined to determine etiology. Focal ischemia superimposed upon conditions producing fatty change is postulated as a pathogenic mechanism for this entity. Focal fatty change may have importance in the differential diagnosis of space-occupying lesions of the liver.

Adult↗

PubMedDate not supplied

Screening for prostate cancer.

Screening for prostate cancer has shown great promise in its ability to detect prostate cancer at a curable stage; however, significant problems exist with respect to our knowledge of its impact on prostate cancer mortality. For the properly informed patient with at least a 10-year life expectancy, it would seem that early detection efforts utilizing digital rectal examination (DRE) and serum prostate-specific antigen (PSA) determination are beneficial. Considerable controversy abounds about early detection and screening and will continue until definitive proof of decreased prostate cancer mortality as a result of effective early detection and treatment regimens is demonstrated. Until then, all men with at least a 10-year life expectancy should be counseled as to the potential benefits and risks. The salient literature is reviewed and commentary made as to the benefits of screening methods that can be invoked as well as their limitations and potential liabilities.

Humans↗

PubMedDate not supplied

Prostate-specific antigen.

Prostate-specific antigen (PSA) has revolutionized the diagnosis and management of men with prostate cancer. Significant advances have been made since the early development of immunoassays. While PSA is useful for staging and monitoring of established disease, it has shown the greatest utility in the realm of early detection realm. PSA is the most important tumor marker; its importance in evaluating men for the possibility of prostate cancer is irrefutable. Enhancing specificity is a pressing need. In this regard, the recognition of the molecular forms of free PSA and complex PSA have shown the most promise and undoubtedly will result in fewer false-positive PSA test results. The salient literature is reviewed and commentary made on the current status of PSA with particular emphasis on methods to enhance its specificity in early detection and applications.

Adult↗

PubMedDate not supplied

Prostate-specific antigen and premalignant change: implications for early detection.

PSA represents a major advance in our tumor marker armamentarium. PIN fulfills the majority of requirements for a premalignant change. If we could determine a subset of individuals with PIN, an enriched population on which to base screening studies would emerge. In this regard the observation that PIN may be associated with elevation of the serum PSA is particularly intriguing. Considerable interest exists for early detection of prostate cancer. The high morbidity and mortality associated with this tumor coupled with the late stage at presentation by conventional means underscore the justification for such enthusiasm. However, the wisdom of screening for a cancer for which the mortality is far less than the histologic incidence remains to be proven. In the final analysis, the question is not whether we can detect more carcinoma, but rather whether we can significantly decrease patient morbidity and mortality. Until prospective randomized clinical trials demonstrate the effectiveness of early detection programs for carcinoma of the prostate, it is difficult to recommend such screening to the general public.

Antigens, Neoplasm↗

PubMedDate not supplied

How to use prostate-specific antigen in the early detection or screening for prostatic carcinoma.

At present, increased early detection of prostate cancer appears to be the most feasible way to reduce cancer-related mortality. As a result significant efforts have been made to identify more men with curable cancer. This article reviews the role of serum prostate-specific antigen in an early detection or screening strategy and describes efforts to enhance the specificity of prostate-specific antigen testing.

Adult↗

PubMedDate not supplied

Prostate-specific antigen: current status.

Prostate-specific antigen (PSA) is the most important of all tumor markers in that it has significant applications in all aspects of the management of men with prostatic disease. Certainly, the most important utilization of PSA is for the early detection of this most ubiquitous of all human neoplasms. This article reviews the salient features of PSA, with particular emphasis on strategies to improve its utility in the diagnosis of prostate cancer. So-called PSA derivatives--including age-specific PSA, PSA velocity, and PSA density--are discussed. With the recognition of molecular forms of PSA, however, the ratio of free-to-total PSA, and now the complex form of PSA, have been shown to be more specific indicators of the presence of malignancy. Significant public interest and research efforts in prostate cancer have resulted in numerous advances over the past decade. The discovery of PSA and the development of assays to measure it will undoubtedly be recorded as one of the most important advances in the management of men with prostate cancer.

Humans↗