Isolation and sequence of the gene encoding ornithine decarboxylase, SPE1, from Candida albicans by complementation of a spe1 delta strain of Saccharomyces cerevisiae

The gene encoding ornithine decarboxylase, SPE1, from the pathogenic yeast Candida albicans has been isolated by complementation of an ornithine decarboxylase-negative (spe1 delta) strain of Saccharomyces cerevisiae. Four transformants, three of which contain plasmids with the SPE1 gene, were isolated by selection on polyamine-free medium. The C. albicans ornithine decarboxylase (ODC) showed high homology with other eukaryotic ODCs at both the amino acid and nucleic acid levels.     

How receptors talk to trimeric G proteins

Stimulated by hormones and sensory stimuli, serpentine receptors promote the release of GDP that is bound to the alpha subunit of trimeric G proteins and its replacement by GTP. Recent investigations have begun to define the sizes, shapes, and relative orientations of receptors and G proteins, the surfaces through which they interact with one another, and conformational changes in both sets of molecules that underlie receptor-catalyzed guanine-nucleotide exchange.     

Clostridium difficile-associated diarrhea: epidemiology, risk factors, and infection control

OBJECTIVES: To evaluate the effectiveness of specific infection control measures on the incidence of Clostridium difficile-associated diarrhea (CDAD) and to identify risk factors for its development. SETTING: 370-bed, tertiary-care teaching hospital with approximately 12,000 to 15,000 admissions per year. METHODS: Several infection control measures were implemented in 1991 and 1992, and the attack rates of CDAD were calculated quarterly. Antibiotic use for 1988 through 1993 was analyzed. A case-control study was conducted from January 1992 to December 1992 to identify risk factors for acquisition of CDAD. RESULTS: From 1989 to 1992, the attack rate of CDAD increased from 0.49% to 2.25%. An increase in antibiotic use preceded the rise in the incidence of CDAD in 1991. Despite implementation of various infection control measures, the attack rate decreased to 1.32% in 1993, but did not return to baseline. Ninety-two cases and 78 controls (patients with diarrhea but with negative toxin assay) were studied. By univariate analysis, history of prior respiratory tract infections (odds ratio [OR], 3.6; 95% confidence interval [CI95], 1.2-10.4), the number of antibiotics, and the duration of exposure to second-generation cephalosporins (OR, 3.55; CI95, 1.47-9.41) and to ciprofloxacin (OR, 7.27; CI95, 1.13-166.0) were related significantly to the development of CDAD. By stepwise logistic regression analysis, only exposure to antibiotics and prior respiratory tract infections (P = .0001 and .0203, respectively) were found to be significant. CONCLUSION: Antibiotic pressure might have contributed to failure of infection control measures to reduce the incidence of CDAD to baseline.     

Yoga breathing through a particular nostril increases spatial memory scores without lateralized effects

Uninostril breathing facilitates the performance on spatial and verbal cognitive tasks, said to be right and left brain functions, respectively. Since hemispheric memory functions are also known to be lateralized, the present study assessed the effects of uninostril breathing on the performance in verbal and spatial memory tests. School children (N = 108 whose ages ranged from 10 to 17 years) were randomly assigned to four groups. Each group practiced a specific yoga breathing technique: (i) right nostril breathing, (ii) left nostril breathing, (iii) alternate nostril breathing, or (iv) breath awareness without manipulation of nostrils. These techniques were practiced for 10 days. Verbal and spatial memory was assessed initially and after 10 days. An age-matched control group of 27 were similarly assessed. All 4 trained groups showed a significant increase in spatial test scores at retest, but the control group showed no change. Average increase in spatial memory scores for the trained groups was 84%. It appears yoga breathing increases spatial rather than verbal scores, without a lateralized effect.