Living conditions and occurrence of malaria in a rural community

Results of a prospective study of the association between environmental factors and malaria occurrence among 1461 individuals in an Indian rural community are reported. A multiplicative model was fitted by relating malaria positivity with different environmental risk factors as categorical variables. The risk of acquiring malaria infections varied significantly within a village stratified by proximity of breeding sources to human dwellings (chi 2 = 19.87, df = 5, p = 0.0000) and different types of houses (chi 2 = 11.32, df = 2, p = 0.0035). People residing in thatched houses with [Relative Risk (RR) = 6.72] and without false ceiling (RR = 11.27) are exposed to greater risk of contracting malaria infections when compared to tiled houses (RR = 1.00). However, malaria infection was not significantly associated with proximity of cattlesheds to human dwellings (chi 2 = 1.54, df = 2, p = 0.46). A significantly high risk was observed in zones where the cattle to man ratio was very low and vice versa (chi 2 = 15.32, df = 6, p = 0.018). These data suggest and corroborate with earlier studies that transmission is a local problem and it varies within a village according to the microepidemiological factors.     

Age-related changes in the response of hepatic succinic dehydrogenase activity to thyroxine and thiourea in lizards

Intraperitoneal injection of thyroxine (T4; 1 microgram/g body weight on alternate days, seven doses) to male garden lizards of three different age groups caused a stimulation of hepatic succinic dehydrogenase activity, the degree of response being higher in the old (63%) than in middle-aged (39%) and young (31%). Percent inhibition of enzyme activity following thiourea treatment (0.05 mg/g body weight on alternate days, three doses) was higher in middle-aged lizards (24%) than in young (10%) and old (12%) ones.     

Lipid composition of sputum from patients with asthma and patients with cystic fibrosis

Lipids from the sputum of patients with asthma and with cystic flbrosis were isolated and characterized. In both cases, lipids constituted approximately 30% of the dry material. Phosphatidylcholine was the most abundant lipid. Significant amounts of phosphatidylethanolamine and phosphatidylglycerol were present. Hexosyl ceramides, sphingomyelin, phosphatidylinositol, lysophosphatidylcholine, and lysophosphatidylethanolamine were present as minor lipid components. Appreciable quantities of neutral lipids were present, of which triglycerides and cholesterol were the main constituents. Phosphatidylcholine, sphingomyelin, and phosphatidylglycerol were highly saturated. Large amounts of phosphatidylcholine containing mostly palmitic acid, particularly in the asthmatic sputum, suggests that this highly saturated phospholipid is synthesized in the upper airways for reasons other than its beneficial surface-active properties in the alveoli.