Characteristics of Hidden Status Among Users of Crack, Powder Cocaine, and Heroin in Central Harlem

This article analyzes hidden status among crack, powder cocaine, and heroin users and setters, in contrast to more accessible users/sellers. Several sampling strategies acquired 657 users (N=559) and sellers (N=98). Indicators of hidden status were those who (1) paid rent in full in the last 30 days, (2) used nonstreet drug procurement. (3) had legal jobs, and (4) earned $1,000 or more in legal income in the last 30 days. Nearly half had at least one indicator: approximately 16% of users/sellers had two to four indicators. In logistic regression analyses, those who had not panhandled in the last 30 days, those who had used powder cocaine in the last 30 days, and those never arrested were the most likely to have hidden status, whether the analysis predicted those having any indicators or those having two to four indicators. The four indicators begin to operationally define hidden status among users of cocaine and heroin.     

A molecular and FISH analysis of structurally abnormal Y chromosomes in patients with Turner syndrome

Fourteen patients with Turner syndrome and a structurally abnormal Y chromosome were analysed by PCR amplification and fluorescence in situ hybridisation for the presence of sequences specific to defined regions of the Y chromosome. Thirteen patients had a mosaic karyotype including a 45,X cell line and one case was non-mosaic in cultured lymphocytes. Ten patients had a pseudodicentric Yp chromosome, two an isodicentric Yq, one a pseudodicentric Yq, and one a derived Y chromosome. Two of the patients with a psu dic(Yp) chromosome had complex karyotypes with more than two cell lines, one of which exhibited five morphologically distinct mar(Y) chromosomes, presumably derived from a progenitor psu dic(Yp). Nine of the ten psu dic(Yp) chromosomes were positive for all Yp and Yq probes used except DYZ1 which maps to Yq12, suggesting a common breakpoint near the Yq euchromatin/heterochromatin boundary. In the three patients with a dicentric Yq chromosome two different breakpoints were observed; in two it was between PABY and the subtelomeric repeat sequence and in one it was between DYZ5 and AMGY in proximal Yp. Our results suggest that the great majority of structurally abnormal Y chromosomes found in Turner syndrome mosaics contain two copies of virtually all of the functional Y chromosome euchromatin.     

The effect of intravenously injected beta very low density lipoprotein on small and large arterial injuries

A series of daily injections of beta very low density lipoprotein (beta-VLDL) was administered over 4-5 days to rabbits whose arteries contained either experimental circumferential lesions or areas of intimal thickening. The circumferential lesions were similar to those that occur spontaneously and were produced by the application of longitudinal tension. The intimal thickening was produced by denuding the endothelium with a balloon catheter. Over the period of injection of beta-VLDL the plasma cholesterol levels rose in a pulse-like manner from 60 to 100 mg/dl. Following cessation of injections the cholesterol levels initially rose further and then decreased to normal levels within 4 weeks. Injections of beta-VLDL, commencing 1-2 days after production of the circumferential lesions, resulted in an increase in the number of mononuclear leukocytes (primarily macrophages) and in a moderate accumulation of lipid by these cells and the medial smooth muscle cells. If the injections were started 14 days postinjury there was some accumulation of lipid in the large lesions but none in small lesions. There was no lipid accumulation in any lesions if the beta-VLDL was administered 3 months postinjury or if the animals were injected 2 days after injury and examined 3 months later. A very slight accumulation of lipid occurred in the intimal thickening, or neo-intima, following a series of beta-VLDL injections given to rabbits 2 or 6 weeks after balloon catheter injury. The series of injections produced a significant increase in the number of mononuclear leukocyte profiles per area of the neo-intima, suggesting an increased infiltration of these cells into the injured artery. These results suggest that a small transient increase in the plasma concentration of cholesterol-carrying lipoproteins may lead to increased infiltration of mononuclear leukocytes into areas of intimal thickening or areas of "spontaneously occurring" injury.     

Education review: Crossing borders--delivering health information management education across state lines

Since its inception in 1992, the associate degree program in health information management (HIM) of the University of Alaska Southeast has been distance delivered across the state; it was the first distance degree program to be approved by the university's Board of Regents. In the spring of 1995, the HIM program was selected to be part of a pilot brokering project of the Western Interstate Consortium on Higher Education, in which member institutions would offer programs to or receive programs from other member institutions. The university's HIM program was selected by New Mexico and Wyoming, and classes for two groups of Wyoming students were initiated in the fall of 1995. The article summarizes the results of the project for the HIM program and future plans. It also provides an overview of some of the challenges facing institutions with out-of-state or multistate program delivery.     

The Variation in Arrestees' Disclosure of Recent Drug Use Across Locations, Drugs, and Demographic Characteristics

This study provides a comprehensive multivariate analysis of drug use disclosure among arrestees interviewed between 2000 and 2001 at 37 sites across the U.S. served by the Arrestee Drug Abuse Monitoring (ADAM) Program. Rates varied widely by drug and across sites. The marijuana disclosure rate varied from 68% in Fort Lauderdale to 93% in Spokane. The cocaine/crack disclosure rate varied from 28% in Chicago to 70% in Kansas City. Moreover, covariates of disclosure differed across drugs. This wide variation in disclosure suggests extreme caution be used when comparing self-reports of prevalence across drugs, locations, and individual characteristics - certainly at least for arrestees.     

Broadband miniature optical ultrasound probe for high resolution vascular tissue imaging

An all-optical ultrasound probe for vascular tissue imaging was developed. Ultrasound was generated by pulsed laser illumination of a functionalized carbon nanotube composite coating on the end face of an optical fiber. Ultrasound was detected with a Fabry-Pérot (FP) cavity on the end face of an adjacent optical fiber. The probe diameter was < 0.84 mm and had an ultrasound bandwidth of ~20 MHz. The probe was translated across the tissue sample to create a virtual linear array of ultrasound transmit/receive elements. At a depth of 3.5 mm, the axial resolution was 64 µm and the lateral resolution was 88 µm, as measured with a carbon fiber target. Vascular tissues from swine were imaged ex vivo and good correspondence to histology was observed.OCIS codes: (110.5125) Photoacoustics, (110.2350) Fiber optics imaging, (060.2380) Fiber optics sources and detectors, (170.7170) Ultrasound, (170.0110) Imaging systems     

Immediate antiviral therapy appears to restrict resting CD4+ cell HIV-1 infection without accelerating the decay of latent infection

HIV type 1 (HIV-1) persists within resting CD4(+) T cells despite antiretroviral therapy (ART). To better understand the kinetics by which resting cell infection (RCI) is established, we developed a mathematical model that accurately predicts (r = 0.65, P = 2.5 × 10(-4)) the initial frequency of RCI measured about 1 year postinfection, based on the time of ART initiation and the dynamic changes in viremia and CD4(+) T cells. In the largest cohort of patients treated during acute seronegative HIV infection (AHI) in whom RCI has been stringently quantified, we found that early ART reduced the generation of latently infected cells. Although RCI declined after the first year of ART in most acutely infected patients, there was a striking absence of decline when initial RCI frequency was less than 0.5 per million. Notably, low-level viremia was observed more frequently as RCI increased. Together these observations suggest that (i) the degree of RCI is directly related to the availability of CD4(+) T cells susceptible to HIV, whether viremia is controlled by the immune response and/or ART; and (ii) that two pools of infected resting CD4(+) T cells exist, namely, less stable cells, observable in patients in whom viremia is not well controlled in early infection, and extremely stable cells that are established despite early ART. These findings reinforce and extend the concept that new approaches will be needed to eradicate HIV infection, and, in particular, highlight the need to target the extremely small but universal, long-lived latent reservoir.     

The MD/PhD pathway to a career in laboratory medicine

Laboratory medicine offers attractive opportunities for individuals who have MD and PhD degrees and advanced training in medicine and the underlying basic biomedical sciences, and these individuals have much to contribute to the field. The modern era of basic biomedical sciences has produced a wealth of genomic, postgenomic, and proteomic knowledge. As a bridge discipline, a major challenge and opportunity for laboratory medicine is to bring these advances to the diagnostic, prognostic, and therapeutic care of patients. The authors believe that, for many reasons, the field of laboratory medicine represents an excellent, although underrecognized, career choice for graduates of MD/PhD programs.