Biomedical subjects

Cameron Marlow

Publications and source records attributed to Cameron Marlow.

4 recordsLinked to original sources

PubMed2006

Ultrasound verification of bladder damage is associated with known biomarkers of bladder cancer in adults chronically infected with Schistosoma haematobium in Ghana.

Long-term infection with urinary schistosomiasis has been associated with development of bladder cancer. However, bladder cancer is difficult to diagnose without invasive measures such as cystoscopy, thus there is little information on the epidemiological extent of the problem. Studies have been either case-control studies or case examinations in different geographical areas, estimating a schistosome-associated bladder cancer incidence of 3-4 cases per 100,000. We have used three indicators to examine the potential bladder cancer problem in an adult rural population in Ghana endemic for urinary schistosomiasis: (i) parasitological positivity; (ii) age prevalence of bladder damage from ultrasound scans; and (iii) detection of biomarkers associated with the presence of bladder cancer. Biomarkers were BLCA-4 test (urine) and nuclear morphometry or quantitative nuclear grading (QNG) of epithelial cells (urine sediment), which quantifies DNA ploidy status and nuclear morphometric descriptors, both of which can detect the presence of bladder cancer. Our data show an increasing association between age, severe bladder abnormalities and the occurrence of these biomarkers. Sixty-two of 73 cytopathology Papanicolaou-stained smears were seen to have squamous metaplasia. Although further investigations are needed, we suggest that schistosome-associated bladder cancer is an important public health concern in areas where Schistosoma haematobium is prevalent.

Adult↗

PubMed2006

Alterations in nuclear structure and expression of proPSA predict differences between native Japanese and Japanese-American prostate cancer.

OBJECTIVES: To differentiate the benign and/or malignant epithelial cells in prostate cancer (PCa) glands of native Japanese (NJ) and Japanese-American (JA) men using biomarkers. METHODS: Tissue microarrays from radical prostatectomy specimens of cancerous and adjacent benign areas from 25 NJ and 25 JA prostate glands were studied. Image analysis was used to quantify total prostate-specific antigen (PSA) and proPSA immunohistochemical staining, as well as the variance of several morphometric features from Feulgen-stained epithelial cell nuclei. Logistic regression analysis was applied to determine whether quantitative nuclear grade (QNG) calculations and PSA immunohistochemical staining could differentiate the two test groups. RESULTS: The QNG model differentiated changes in the benign epithelium of the two Japanese groups with an area under the receiver operating characteristic curve of 84% and accuracy of 82% (P = 0.0001). A second QNG model differentiated changes in the malignant epithelium of the two groups with an area under the receiver operating characteristic curve of 84% and accuracy of 76% (P = 0.0023). Logistic regression models combining proPSA immunohistochemical data and QNG from either benign or malignant tissue components yielded areas under the receiver operating characteristic curve of 96% and 91% (P <0.0001) for differentiation of the JA and NJ groups, respectively. CONCLUSIONS: Unique nuclear morphometric alterations demonstrated by QNG combined with proPSA immunohistologic localization independently predicted for significant differences between NJ and JA men with PCa. These preliminary observations indicate a basis for biologic and molecular alterations in the benign adjacent and malignant epithelium between these two groups.

Asian↗

PubMed2006

Immunohistochemical staining of precursor forms of prostate-specific antigen (proPSA) in metastatic prostate cancer.

Precursors of prostate-specific antigen (proPSA) have been previously shown to be more concentrated in prostate cancer tissue. This study characterizes the immunohistochemical staining (IHS) of proPSA forms in metastatic prostate cancer compared with prostate specific antigen (PSA) and prostatic acid phosphatase (PAP). A tissue microarray, consisting of 74 cases of metastatic prostate carcinoma and control tissues, was used. IHS, using monoclonal antibodies against proPSA with a truncated proleader peptide containing 2 amino acids ([-2]pPSA), native ([-5/-7]pPSA), PSA, and PAP, was analyzed. The monoclonal antibodies were specific for both benign and malignant prostatic glandular tissue. IHS with [-5/-7]pPSA showed the least number of cases with negative staining (3%), and the most number of cases with moderate or strong staining (76%). In the 60 cases where all 4 stains could be evaluated, none of them were negative for proPSA and positive for PSA or PAP, and all 7 cases that were negative for both PSA and PAP showed IHS to proPSA. [-5/-7]pPSA (native proPSA) may be a better marker than PSA and PAP in characterizing metastatic prostate adenocarcinoma, with most of the cases showing positivity for the marker. Even cases that were negative for PSA and PAP, were reactive for proPSA. Such enhanced detection is particularly important in poorly differentiated carcinomas involving metastatic sites where prostate carcinoma is a consideration. A panel of markers, including proPSA, should be performed when metastatic prostate carcinoma is in the differential diagnosis.

Acid Phosphatase↗

PubMed2005

Determinants and consequences of sexual networks as they affect the spread of sexually transmitted infections.

Because pathogens spread only within the unique context of a sexual union between people when one person is infectious, the other is susceptible to new infection, and condoms are not used to prevent transmission, the epidemiological study of sexually transmitted infections (STIs) is particularly challenging. Social network analysis entails the study of ties among people and how the structure and quality of such ties affect individuals and overall group dynamics. Although ascertaining complete sexual networks is difficult, application of this approach has provided unique insights into the spread of STIs that traditional individual-based epidemiological methods do not capture. This article provides a brief background on the design and assessments of studies of social networks, to illustrate how these methods have been applied to understanding the distribution of STIs, to inform the development of interventions for STI control.

Adolescent↗