Risk factors for human immunodeficiency virus infection in intravenous drug users

To identify risk factors for human immunodeficiency virus (HIV) infection in intravenous drug users, we undertook a study of the seroprevalence of HIV antibody in 452 persons enrolled in a methadone-treatment program in the Bronx, New York. The seroprevalence of HIV was 39.4 percent overall, 49.1 percent in blacks, 41.8 percent in Hispanics, and 17.2 percent in non-Hispanic whites (P less than 0.001 for all comparisons). The presence of HIV antibody was associated with the number of injections per month (P less than 0.001), the percentage of injections with used needles (P less than 0.001), the average number of injections with cocaine per month (P less than 0.001), and the percentage of injections with needles that were shared with strangers or acquaintances (P less than 0.001), a practice that was more common among blacks and Hispanics than among whites. The number of heterosexual sex partners who used intravenous drugs was associated with HIV infection in women (P less than 0.004) and was the only risk factor found for users who had not injected drugs after 1982 (P less than 0.05). The presence of HIV antibody was independently associated with being black or Hispanic (adjusted odds ratio, 4.56; 95 percent confidence interval, 2.65 to 8.14), a more recent year of the last injection of drugs (adjusted odds ratio, 1.24; 95 percent confidence interval, 1.13 to 1.35), the percentage of injections of drugs that took place in "shooting galleries" (adjusted odds ratio, 1.49; 95 percent confidence interval, 1.19 to 1.88), having sex partners who used intravenous drugs (adjusted odds ratio 1.24; 95 percent confidence interval, 1.06 to 1.45), and low income (adjusted odds ratio, 1.55; 95 percent confidence interval, 1.10 to 2.17). We conclude that differences in both the social setting of drug use and behavior related to injection carry different risks for infection with HIV and may explain, in part, the higher seroprevalence of HIV among blacks and Hispanics. In addition, we found that heterosexual activity was an independent risk factor for drug users.     

Lipid lowering improves endothelial functions

The healthy endothelium usually provides an anticoagulant, vasodilatory and anti-inflammatory spectrum of functions that are central in vascular homeostasis. Dysfunction of the endothelium is a common feature of all phases of atherosclerosis. Hypercholesterolemia provokes many aspects of endothelial dysfunction before and during the development of atheroma. For example, a high cholesterol diet leads to the formation of a fatty streak and the recruitment and binding of blood leukocytes to the artery wall. This process requires expression by the endothelial cells of adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1). In rabbits that are fed an atherogenic diet, the aortic endothelium, which usually expresses little VCAM-1, shows foci of VCAM-1 expression soon after initiating this diet. Furthermore, lowering plasma cholesterol by diet or drugs down-regulates the expression of VCAM-1 and reduces the density of inflammatory cells in the atherosclerotic plaque. Hypercholesterolemia also attenuates normal vasodilatation to several stimuli such as exercise and acetylcholine. In healthy subjects, the vascular endothelium produces the vasodilator nitric oxide. In atherosclerosis, however, nitric oxide bioavailability is impaired. As a result, atherosclerotic coronary arteries commonly display a vasoconstrictor response when challenged with acetylcholine. Lipid lowering appears to favorably influence endothelial vasomotor and inflammatory functions in ways that may benefit patients with coronary artery disease. Continued probing of the basic mechanisms of endothelial dysfunction and its treatment may lead to new therapies that offer clinical benefits in patients with atherosclerosis, including reductions in coronary events.     

Color Doppler imaging of fibroadenomas of the breast with histopathologic correlation

PURPOSE: This study was conducted to characterize the spatial distribution of blood vessels in breast fibroadenomas. METHODS: We performed a prospective study to map the anatomic distribution of the vessels in 29 fibroadenomas of the breast using color Doppler sonography. We categorized the detected vessels according to their location in or on the fibroadenoma, counted the different types of vessels, and tested for correlations between vessel distributions or numbers and histopathologic findings. RESULTS: Blood flow was demonstrated in 24/29 (83%) of fibroadenomas. We found 3 vessel types: feeding vessels, which are prominent vessels leading from the surrounding breast tissue into the fibroadenoma; capsular vessels, which are located within the tissue capsule; and segmental vessels, which are located within the fibrous septa of the fibroadenoma. Capsular and segmental vessels were demonstrated in 23/24 (96%) and 24/24 (100%) of the cases, respectively. Feeding vessels were seen in 12/24 (50%) of the cases. Histopathologic analysis revealed the same location and distribution of the vessels as color Doppler imaging. However, there was no correlation between numbers of vessels counted on sonograms and on histopathologic specimens. CONCLUSIONS: Examination of the vascularity demonstrated on color Doppler imaging helps in the diagnosis of benign breast neoplasms such as fibroadenomas.     

Precordial electrocardiographic mapping in the identification of patients with left main stem narrowing

This study was designed to determine if exercise testing using 16-lead precordial mapping can be used to identify patients with left main stem narrowing. In a group of 235 consecutive patients undergoing coronary angiography there were 35 patients with left main stem narrowing. The patients with left main stem disease differed from the others in that not only did they develop extensive S-T segment depression, but more specifically these changes occupied a characteristic position high on the precordium above the usual site of the precordial leads of the 12-lead electrocardiogram. This finding was then tested prospectively in a second group of 100 patients. Fourteen of the 100 patients had left main stem narrowing; the sensitivity and specificity of S- T segment changes high on the precordium in identifying patients with left main stem disease were 82 and 84% respectively. Thus precordial mapping and exercise testing is valuable in the diagnosis of patients with left main stem narrowing. The technique is simple and inexpensive and provides data not available using the conventional precordial leads of the 12-lead electrocardiogram.     

Patient Safety Through RFID: Vulnerabilities in Recently Proposed Grouping Protocols

As RFID-tagged systems become ubiquitous, acceptance of this technology by the general public necessitates addressing related security/privacy issues. The past eight years have seen an increasing number of publications in this direction, specifically using cryptographic approaches. Recently, the Journal of Medical Systems published two papers addressing security/privacy issues through cryptographic protocols. We consider the proposed protocols and identify some existing vulnerabilities.     

A Review of Barriers to Utilization of the Medicare Hospice Benefits in Urban Populations and Strategies for Enhanced Access

Disparities in access to health care extend to end-of-life care. Lack of access to hospice mirrors lack of access to health maintenance and primary care. Patients who are served by hospice nationally are disproportionately white and likely to reside in economically stable communities. In many urban low-income communities, less than 5% of decedents receive hospice care in the last 6 months of life. This review focuses on barriers to palliative care and hospice in urban, predominantly low-income communities, including cultural and reimbursement factors and the paucity of hospice providers, outreach projects, and in-patient hospice beds in urban communities. This review will also address some strategies that are being implemented by hospices locally and nationally to overcome demographic barriers to hospice care.     

Application of Molecular Biology Studies to Gene Therapy Treatment Strategies

The diagnosis of pancreatic cancer continues to produce fear in both patients and practitioners in large part owing to the likely incurability in all for whom the diagnosis is made. It is this reality that continually motivates the surgical and medical oncologists who endeavor to treat these patients. Currently, the cure rate for pancreatic cancer has improved only minimally, and the overall survival of patients remains dismal, with fewer than 5% of patients alive at 5 years and 92% of these patients dead at 2 years. This current treatment status has stimulated numerous studies endeavoring to understand the diverse mechanisms of cell growth in this tumor. Intensive investigative efforts have produced the understanding of new tumor suppressor genes such as DPC4 and an increasing understanding of tyrosine kinase receptors and signal transduction and their regulation of programmed cell death (apoptosis). Detection of these numerous genetic defects may give new insights and understanding of the highly chemo- and radioresistant nature of pancreatic cancer. These same findings also provide the basis for the development of new potential therapies for pancreatic cancer through gene therapy. This paper reviews the significant molecular biologic findings and their influence on the development of gene therapy strategies in the treatment of pancreatic adenocarcinoma.