Body growth, mitochondrial enzymatic capacities and aspects of the antioxidant system and redox balance under calorie restriction in young turbot (Scophthalmus maximus, L.).

Caloric reduction (cr) without undernutrition has been found to enhance stress resistance and life span in endotherms and ectotherms. We investigated the effect of 30% reduction in food offering on growth, aerobic capacities and oxidative stress parameters in young turbot (Scophthalmus maximus, L.).No differences in body weight, length and hepatosomatic index between the ad libitum fed (AL) and the calorie reduced (CR) group occurred after 55 days of diet application. Of the mitochondrial marker enzymes, only citrate synthase activity in liver was reduced under CR, whereas muscle CS activity and cytochrome oxidase activity in both tissues remained the same in both feeding groups. The concentration of reduced glutathione increased significantly during feeding in muscle of CR fish, resulting in a more reduced glutathione redox ratio (GSH/GSSG) compared to AL fish muscle. TBARS (lipid peroxidation) but not protein carbonyl content (protein oxidation) was significantly reduced in CR fish muscle. Liver oxidative stress parameters did not vary significantly between experimental feeding groups.We conclude that 30% calorie reduction over 8 weeks has no adverse effect on young turbot. On the contrary, cr supports a reduced tissue oxidation state and reduces accumulation of lipid peroxidation products in muscle at sustained muscular aerobic capacity

Delayed infection, family size and malignant lymphomas

BACKGROUND—The annual incidence of non-Hodgkin's lymphomas (NHL) is increasing by 3%-4% in different parts of the developed world. Excesses of NHL have been observed in populations exposed to immunosuppressants and to HIV, but these causes do not explain the increasing trends. It is suggested that delayed infection could explain NHL trends, through an impairment of the Th1/Th2 lymphocyte patterns.
METHODS—In a population-based study on 1388 patients with NHL, 354 with Hodgkin's disease (HD) and 1718 healthy controls, the age of first occurrence of bacterial and viral diseases was investigated. Clinical records were perused in one centre to check the anamnestic data.
FINDINGS—The age of occurrence of bacterial and viral diseases was significantly higher among NHL patients than in the controls. The association between later age at first bacterial or viral disease was limited to small families (OR= 1.95; 95% confidence intervals 1.26, 3.00, for age 4-8 at first infection; OR=1.91; 1.19, 3.06,( )for age 9+, compared with less than 4). The association was more obvious for bacterial diseases (possibly for the lower degree of misclassification). High grade lymphomas showed the strongest association. The later age of occurrence of bacterial or viral diseases in NHL patients is consistent with a higher incidence of lymphomas observed in higher social groups. No clear association was found between HD and age at first bacterial or viral diseases.
INTERPRETATION—It is proposed that delayed infection could explain the increasing NHL trends, through an impairment of the Th1/Th2 lymphocyte patterns. The model of delayed infection has been proposed also to explain increasing prevalence rates of asthma.