Function of the RNA Coliphage Qβ Proteins in Medical In Vitro Evolution.

Qβ is a positive (+) single-stranded RNA bacteriophage covered by a 25 nm icosahedral shell. Qβ belongs to the family of Leviviridae and is found throughout the world (bacterial isolates and sewage). The genome of Qβ is about 4.

The acute chest syndrome in sickle cell disease: incidence and risk factors. The Cooperative Study of Sickle Cell Disease.

The acute chest syndrome (ACS), a pneumonia-like illness in sickle cell patients, is one of the most frequent causes of their morbidity and hospitalizations. Repeated ACS events may predict the development of chronic lung disease. ACS is reported as a frequent cause of death in these patients.

HIV-1 and HTLV-I in sexually transmitted disease clinics in the Dominican Republic.

A cross-sectional seroprevalence study of human immunodeficiency virus type 1 (HIV-1) and human T-cell lymphotropic virus type I (HTLV-I) was undertaken among 494 attendees in two Santo Domingo sexually transmitted disease clinics in 1989. All participants were evaluated for Neisseria gonorrhoeae, Chlamydia trachomatis, syphilis, and genital ulcers. Of the 494 participants, 15 (3.

Pain in sickle cell disease. Rates and risk factors.

Background And Methods: Acute episodes of pain are the principal symptom of sickle cell disease, but little is known about the epidemiologic features of these episodes or risk factors for them, nor is it known whether patients with high rates of such episodes die prematurely. We prospectively studied the natural history of sickle cell disease in 3578 patients ranging from newborns to persons up to 66 years old who were followed at clinical centers across the United States.

Results: There were 12,290 episodes of pain in 18,356 patient-years.

The accuracy of substitution rules for health risk appraisals.

Abstract Health Risk Appraisals (HRAs) have been in increasingly wide use over the past 20 years as health education tools designed to encourage healthy behaviors. A major criticism of HRAs has been the error introduced by missing or incorrectly-specified responses by clients, especially regarding physiological measures such as blood pressure and cholesterol. Four HRAs were randomly assigned to members of a random sample of Massachusetts residents as part of a trial to assess the reliability and validity of HRA instruments.