Solution conformation of a five-nucleotide RNA bulge loop from a group I intron.

We present the solution conformation, determined by NMR spectroscopy, of a five-nucleotide RNA bulge loop. The bulge interrupts the stem of a 25-nucleotide RNA hairpin, and its sequence and flanking sequences are those of a conserved bulge from a Group I intron. The secondary structure of the bulge loop in the hairpin context is that predicted by the secondary structure prediction algorithm of Zuker. It differs, however, from the secondary structure deduced from sequence covariation of the bulge in the context of the functionally folded Group I introns and observed in the crystal structure of an independently folding domain of the Group I intron from Tetrahymena thermophila. This difference represents an exception to the heierarchical model of RNA folding in which preformed elements of secondary structure interact to form a tertiary structure. The three-dimensional structure of the bulge loop is characterized by discontinuous base stacking. Adjacent adenines stack with each other and with the flanking double helices. However, the position of the central uracil is not well defined by NOE distance constraints and is a point of discontinuity in the base stacking.

Trichinosis: common source outbreak related to commercial pork.

Fifteen patients had trichinosis after eating raw or undercooked commercial pork sausage produced by a local processing plant. Even though it is recommended that all fresh pork be cooked to a temperature of at least 171 degrees F (77 degrees C) to ensure a sufficient margin of safety, this is not always done, and sporadic outbreaks continue to occur. Control strategies to prevent human trichinosis should include trichinosis surveillance of all commercial swine, as well as strict compliance with current regulations.

Family history fails to detect the majority of children with high capillary blood total cholesterol.

To examine the predictive value of family history in detecting children with high blood cholesterol, finger-stick screening was done in 1,118 children ages 9-10 whose parents provided parental and grandparental history of cardiovascular disease events and risk factors. Mean blood total cholesterol was 167.7 mg/dl with no significant gender or ethnic differences. Of 157 children with blood cholesterol 200 mg/dl or greater, only 61 (38.9%) had a family history of early myocardial infarction or hyperlipidemia; however, the prevalence of a positive family history varied from 2.8% in Vietnamese-Americans to 38.5% in Spanish-surnamed students to 52.6% in all other children. Adherence to current policies recommending screening only children with a positive family history will result in failing to detect a majority of children whose blood cholesterol levels exceed desirable levels for adults, particularly those from ethnic families recently arrived in the U.S.

School-based blood cholesterol screening.

Coronary artery disease, the major cause of death in developed countries, begins early in childhood. Elevated blood cholesterol, a major risk for coronary artery disease in adults, has been associated at autopsy with atherosclerotic disease in children. To explore the feasibility of mass screening of blood cholesterol levels in children, a school-based screening and education program for fourth-graders was carried out in a Southern California school district. Approximately 10% of the children had blood cholesterol levels of 200 mg/dl or more, the upper limit of desirable levels for adults. These children and their parents returned for repeat cholesterol testing and nutrition counseling. A family history of early coronary artery disease was present in only one third of the children with high cholesterol levels; this fact, coupled with consumable costs less than $2 per child, suggests that cholesterol screening is a practical, cost-effective addition to school health programs.

Nosocomial bloodstream infections: secular trends in a statewide surveillance program in Virginia.

Over a 7-year period (1978-1984) the authors studied the rates of nosocomial bloodstream infections in acute-care hospitals participating in a statewide surveillance network in Virginia. A total of 4,617 hospital-acquired bloodstream infections were documented among 1,807,989 patients at risk for an overall rate of 25.5 cases per 10,000 patient admissions/discharges (annual range = 22.1 to 30.7). Compliance of reporting for Virginia hospitals averaged 58% (1 to 5 monthly reports in a study year), and 39% (greater than or equal to 6 monthly reports annually). Significant changes in bloodstream infection rates (cases per 10,000 patient admissions/discharges) due to specific pathogens included the following: coagulase-negative staphylococci increased from a rate of 1.3 to 4.5 (P = .0003), and those due to all gram-positive cocci increased from a rate of 7.5 to 11.4 (P = .03). Candida species increased from a rate of 0.1 to 1.5 (P = .005). The data show a continuing rise of nosocomial Candida BSI and clearly document the re-emergence of gram-positive cocci as major nosocomial bloodstream pathogens.

Hospital-acquired infections in intensive care unit patients: an overview with emphasis on epidemics.

Surveillance activities for the detection of nosocomial infections at the University of Virginia Hospital (Charlottesville, Virginia) and at hospitals participating in the Virginia Statewide Infection Control Program have focused on outbreaks and device-related infections which are potentially preventable. Eleven outbreaks of nosocomial infections were identified at the University of Virginia Hospital between January 1, 1978 and December 31, 1982 (9.8 outbreaks/100,000 admissions). Ten of the 11 were centered in critical care units. The 269 patients involved in the epidemics represented 0.2% of all hospital admissions and 3.7% of all patients who developed nosocomial infections. Eight of the 11 outbreaks involved infection of the bloodstream, and the 90 patients who developed a bloodstream infection as part of an epidemic represented 8% of all patients with nosocomial bloodstream infections identified during the five-year study period. The reservoir of the 11 outbreaks involved devices (5), contaminated cocaine (1), probable blood products (1), other patients (3), and nursing personnel (1). Forty-one percent of all nosocomial bloodstream infections and 41% of all nosocomial pneumonias occurred in intensive care units (ICUs). In 38 hospitals in the state of Virginia with ICUs and practitioners who voluntarily reported surveillance data between June 1, 1980 and May 31, 1982, there were 264,757 patients admitted and a crude infection rate of 3%. Of note is that 1,867 of the 7,407 nosocomial infections (25%) occurred in the ICU patients. Several factors point to a compelling argument that the highest priority in infection control resources be assigned to the prevention and control of ICU infections: ICU patients often have serious device-related infections and may be identified as high risk prior to infection.(ABSTRACT TRUNCATED AT 250 WORDS)