Brain imaging and cognition in young narcoleptic patients.

The relationship between functional brain images and performances in narcoleptic patients and controls is a new field of investigation. We studied 71 young, type 1 narcoleptic patients and 20 sex- and age-matched control individuals using brain positron emission tomography (PET) images and neurocognitive testing. Clinical investigation was carried out using sleep-wake evaluation questionnaires; a sleep-wake study was conducted with actigraphy, polysomnography, multiple sleep latency test (MSLT), and blood tests (with human leukocyte antigen typing). The continuous performance test (CPT) and Wisconsin card sorting test (WCST) were administered on the same day as the PET study. PET data were analyzed using Statistical Parametric Mapping (version 8) software. Correlation of brain imaging and neurocognitive function was performed by Pearson's correlation. Statistical analyses (Student's t-test) were conducted with SPSS version-18. Seventy-one narcoleptic patients (mean age: 16.15 years, 41 boys (57.7%)) and 20 controls (mean age: 15.1 years, 12 boys (60%)) were studied. Results from the CPT and WCST showed significantly worse scores in narcoleptic patients than in controls (P < 0.05). Compared to controls, narcoleptic patients presented with hypometabolism in the right mid-frontal lobe and angular gyrus (P < 0.05) and significant hypermetabolism in the olfactory lobe, hippocampus, parahippocampus, amygdala, fusiform, left inferior parietal lobe, left superior temporal lobe, striatum, basal ganglia and thalamus, right hypothalamus, and pons (P < 0.05) in the PET study. Changes in brain metabolic activity in narcoleptic patients were positively correlated with results from the sleepiness scales and performance tests. Young, type 1 narcoleptic patients face a continuous cognitive handicap. Our imaging cognitive test protocol can be useful for investigating the effects of treatment trials in these patients.

Lethal effect of microwaves on spores of Bacillus spp.

Strains representing four types of common heat-resistant spores of Bacillus spp., B. cereus CCRC 14655, B. coagulans CCRC10606, B. licheniformis CCRC14693, and B. subtilis CCRC14199, were heated with microwaves at different power levels and under different conditions in salt solutions, starch solutions, and containers. The results of this study showed that B. licheniformis spores had the highest microwave tolerance at a power level of 100% for different incubation times. B. coagulans spores showed the lowest microwave tolerance in salt solutions with water activity values of 0.6, 0.7, 0.8, and 0.9, and B. licheniformis spores were the most resistant in the tested salt solutions at different incubation times. An analysis of the effect of the viscosity of the medium revealed that the bacteria had the lowest microwave resistance in a medium containing <0.8% starch in solution. The microwave resistance levels of the test microorganisms were the lower in glass containers than in polypropylene containers and aluminum foil-enclosed pouches. Of the four species of bacilli, B. licheniformis had the highest microwave tolerance (P < 0.05) under all conditions.