Isolation and characterization of a novel gene sfig in rat skeletal muscle up-regulated by spaceflight (STS-90)

We obtained the skeletal muscle of rats exposed to weightless conditions during a 16-day-spaceflight (STS-90). By using a differential display technique, we identified 6 up-regulated and 3 down-regulated genes in the gastrocnemius muscle of the spaceflight rats, as compared to the ground control. The up-regulated genes included those coding Casitas B-lineage lymphoma-b, insulin growth factor binding protein-1, titin and mitochondrial gene 16 S rRNA and two novel genes (function unknown). The down-regulated genes included those encoding RNA polymerase II elongation factor-like protein, NADH dehydrogenase and one novel gene (function unknown). In the present study, we isolated and characterize done of two novel muscle genes that were remarkably up-regulated by spaceflight. The deduced amino acid sequence of the spaceflight-induced gene (sfig) comprises 86amino acid residues and is well conserved from Drosophila to Homo sapiens. A putative leucine-zipper structure located at the N-terminal region of sfig suggests that this gene may encode a transcription factor. The up-regulated expression of this gene, confirmed by Northern blot analysis, was observed not only in the muscles of spaceflight rats but also in the muscles of tail-suspended rats, especially in the early stage of tail-suspension when gastrocnemius muscle atrophy initiated. The gene was predominantly expressed in the kidney, liver, small intestine and heart. When rat myoblastic L6 cells were grown to 100% confluence in the cell culture system, the expression of sfig was detected regardless of the cell differentiation state. These results suggest that spaceflight has many genetic effects on rat skeletal muscle

Relationship between job stress, temperament and depressive symptoms in female nurses

Objectives: A casual relationship between temperament, job stress and depressive symptoms has not been established yet. The purpose of this study was to assess the relationships between job stress, temperament and depressive symptoms in female nurses at a Japanese general hospital. Material and Methods: A self-report survey was conducted among 706 nurses. We measured job stress, temperament, and depressive symptoms using the Brief-Job Stress Questionnaire, the TEMPS-A and a screening scale of items from the Ministry of Health, Labour and Welfare of Japan. In order to examine the causal relationship between the measures the stepwise multiple regression and path analyses were used. Results: Depressive symptoms were modestly correlated with job stress (γ = -0.23-0.30). Except for hyperthymic temperament measures, the correlations between depressive symptoms and temperament types were significant and moderate (γ = 0.36-0.50). Overtime, job control as well as depressive and cyclothymic types of temperament were significantly correlated with depressive symptoms (β = 0.15, p < 0.05; β = 0.19, p < 0.01; β = 0.26, p < 0.001; β = 0.32, p < 0.001, respectively). Path-analysis revealed that depressive and cyclothymic types of temperament influenced depressive symptoms both directly (β = 0.67, p < 0.001) and indirectly via job stress (β = 0.35, p < 0.001 from temperament to job stress; β = 0.20, p < 0.05 from job stress to depressive symptoms). Irritable and anxious types of temperament and quantitative job overload did not contri­bute to the path-analytic model. Conclusions: Health care professionals should consider temperament, especially depressive and cyclothymic types, in order to help employees cope better with job stress factors. We need further research about the effective intervention to help employees better cope with their job stress

Effects of the development changes in dentition on the retention of mouthguards

Summary The use of mouthguards is one of the main strategies that are considered effective in preventing sports–related trauma.Although mouthguards are recommended for use in children during sports activities,little is known as to how growth and developmental changes in the oral cavity, jaw, and dentition affect the retention of mouthguards. In the present study, we designed mouthguards for primary,mixed(4 types),and permanent detention stages and performed tensile testing to determine the effects of dental growth and development on their retention.We also designed mouthguards for the left maxillary second milk molar,left maxillary second premolar, and left maxillary first molar to determine how the shape of the teeth affects their retention.Data was analyzed statistically,and the following results were obtained:1.Mouthguards for permanent detention stage had a significantly higher level of retention than those for primary and mixed detention stages.2.Mouthguards for primary detention stage had a significantly lower level of retention than those for mixed and permanent detention stages. 3.The retention of mixed detention stage mouthguards became poorer with the number of teeth requiring relief.4.Differences in the shape of the teeth(left maxillary second milk molar, left maxillary second premolar, left maxillary first molar)had no significant effect on the retention of mouthguards.These findings indicate that the level of mouthguard retention is lower in children at primary and mixed detention stages than in adults and children with complete eruption of central incisor to second molar.This difference may be attributed to the differences in the coverage areas of mouthguard