Magnetic resonance angiography findings in the early post-carotid endarterectomy period

This preliminary study was designed to investigate the ability of multiple axial volume three-dimensional fourier transform (3DFT) time-of-flight (TOF) magnetic resonance angiography (MRA) to depict the carotid bifurcation in the early post-carotid endarterectomy period. Five patients underwent intra-operative digital subtraction angiography (DSA) and carotid MRA within 5 days of carotid endarterectomy. An axial volume fast imaging in steady-state precession (FISP) gradient-echo 3DFT TOF carotid MRA technique in this limited series appeared to display accurately the surgically significant abnormalities at the carotid bifurcation after endarterectomy. However, in normal or near-normal intra-operative DSA studies, overestimation of internal carotid artery stenoses was encountered. Postoperative MRA demonstrates potential as a useful non-invasive investigation after carotid endarterectomy but should be interpreted with caution until larger studies become available.     

Colon cancer screening in the ambulatory setting

BACKGROUND: Despite evidence of decreased mortality, recommendations for colon cancer screening have not been widely implemented by physicians. The objective of this study was to determine patient and clinician factors associated with screening for colon cancer. METHODS: A retrospective review of computerized medical records from primary care practices in an academic medical center was performed. Patients comprised men and women aged 50-74 with at least one visit between July 1, 1995 and June 30, 1997. Measurements included Fecal occult blood testing in the past 1 or 2 years, sigmoidoscopy in the previous 5 or 10 years, or colonoscopy in the past 10 years. RESULTS: A total of 6,039 patients were included in the analysis. Fecal occult blood testing had been performed in 44% of patients and sigmoidoscopy in 26%. Fifty-three percent of patients had undergone some type of colon cancer screening. In multivariate analysis, patient factors predictive of fecal occult blood testing included age (odds ratio (OR) per 5 years 1.05; 95% confidence interval 1.04, 1.06), Asian ethnicity (OR 1.23; 1.08, 1.41), number of visits during the study period (OR 1.05; 1.04, 1.06), recency of the last visit (OR 1.03; 1.02, 1.04), and having private insurance (OR 1.65; 1.04, 2.62). Predictors of sigmoidoscopy were similar except that patients with a family history of colon cancer and those with managed care insurance were also more likely to undergo sigmoidoscopy. Patients of nurse practitioners were less likely to receive fecal occult blood testing than were patients of physicians (OR 0.78; 0.65, 0.93). Patients of residents were less likely to undergo sigmoidoscopy than were patients of faculty (OR 0.79; 0.66, 0.94). CONCLUSIONS: Among patients seen in primary care practices, rates of colon cancer screening remain low, especially in patients who are younger, who have been seen less frequently, who are uninsured, or who do not have managed care insurance. Future research should explore these differences and should focus on increasing screening in all patient groups, especially in those who are underscreened.     

The G gamma / T-15 transgenic mouse model of androgen-independent prostate cancer: target cells of carcinogenesis and the effect of the vitamin D analogue EB 1089.

Transgenic mouse models of prostate cancer provide unique opportunities to understand the molecular events in prostate carcinogenesis and for the preclinical testing of new therapies. We studied the G gamma T-15 transgenic mouse line, which contains the human fetal globin promoter linked to SV40 T antigen (Tag) and which develops androgen-independent prostate cancer. Using the immunohistochemistry of normal mouse prostates before tumor formation, we showed that the target cells of carcinogenesis in G gamma T-15 mice are located in the basal epithelial layer. We tested the efficacy of the 1,25(OH)(2)D(3) analogue, EB 1089, to chemoprevent prostate cancer in these transgenic mice. Compared with treatment with placebo, treatment with EB 1089 at three different time points before the onset of prostate tumors in mice did not prevent or delay tumor onset. However, EB 1089 significantly inhibited prostate tumor growth. At the highest dose, EB 1089 inhibited prostate tumor growth by 60% (P = 0.0003) and the growth in the number of metastases, although this dose also caused significant hypercalcemia and weight loss. We conducted several in vitro experiments to explore why EB 1089 did not prevent the occurrence of the primary tumors. EB 1089 significantly inhibited the growth of a Tag-expressing human prostate epithelial cell line, BPH-1, and an androgen-insensitive subline of LNCaP cells [which was not inhibited by 1,25(OH)(2)D(3)]. Thus, neither Tag expression nor androgen insensitivity explain the absence of chemopreventive effect. Conversely, neither 1,25(OH)(2)D(3) nor EB 1089 inhibited the growth of the normal rat prostate basal epithelial cell line NRP-152. It is likely that EB 1089 was not effective in delaying the growth of the primary tumor in G gamma T-15 transgenic mice because the target cells of carcinogenesis in these mice are located in the basal epithelial layer. We conclude that G gamma T-15 transgenic mice are a useful model for testing vitamin D-based therapies in androgen-insensitive prostate cancer but are not suitable for studies of vitamin D-based chemoprevention. The superiority of EB 1089 over 1,25(OH)(2)D(3) in the growth suppression of androgen-insensitive prostate cancer cells supports the use of EB 1089 in androgen-insensitive prostate cancer.     

Aspergillus endocarditis in chronic granulomatous disease

We report the first case, to our knowledge, of Aspergillus endocarditis in chronic granulomatous disease in a patient who also had an atrial septal defect. A diagnosis was made on culture of the organism from the mass despite extensive prior investigation. The presence of distinctive skin lesions as a diagnostic clue of fungaemia is highlighted. Possible advances in diagnosis by detection of fungal cell wall components and in prophylaxis by use of itraconazole are referred to. We conclude that fungal endocarditis should be considered in this condition, especially in the presence of a structural heart defect.     

Regional myocardial dysfunction: evaluation of patients with prior myocardial infarction with fast CT

A prototype ultrafast cine computed tomographic (CT) scanner, designed specifically for cardiac imaging, was used to evaluate a preliminary series of patients with prior myocardial infarction (n = 21) and a control group without coronary artery disease (n = 5). Multilevel 50-msec CT scan exposures were obtained during peripheral intravenous bolus injections of contrast medium. A comparison was made between cine-CT scans and standard left ventriculographic images in assessing segmental left ventricular motion. Results indicate that cine CT, performed at sufficiently rapid speeds (20 scans per second) to allow useful analysis of regional ventricular wall motion, can provide adequate image quality. Analysis of 110 segments revealed a good correlation (90.9%) between the two techniques in characterizing normal from abnormal regional wall motion. Cine CT, based on this initial study, demonstrates considerable potential for evaluating not only cardiac chamber dimensions but also segmental wall dynamics.     

Latino populations: a unique opportunity for the study of race, genetics, and social environment in epidemiological research

Latinos are the largest minority population in the United States. Although usually classified as a single ethnic group by researchers, Latinos are heterogeneous from cultural, socioeconomic, and genetic perspectives. From a cultural and social perspective, Latinos represent a wide variety of national origins and ethnic and cultural groups, with a full spectrum of social class. From a genetic perspective, Latinos are descended from indigenous American, European, and African populations. We review the historical events that led to the formation of contemporary Latino populations and use results from recent genetic and clinical studies to illustrate the unique opportunity Latino groups offer for studying the interaction between racial, genetic, and environmental contributions to disease occurrence and drug response.     

Ferromagnetic materials in patients: detection before MR imaging

A number of surgical clips and other metallic materials embedded within patients have ferromagnetic properties that present a potential hazard when in the strong fields associated with magnetic resonance imaging. Several types of magnetometers and metal detectors were investigated as possible pre-imaging screening devices. The sensitivities and costs of these devices are given.