Chronic non-infective conjunctivitis in rabbits.

A high proportion (36%) of rabbits in a long-term experiment developed a severe chronic purulent conjunctivitis. Bacteriological examination failed to reveal an organism common to all cases, and the condition was only partially controlled by a neomycin and hydrocortisone eye ointment. Cutting down the possibility of hay dust entering the rabbits' eyes led to marked improvement: the conjunctivitis was virtually eliminated when hay was given in a specially-designed solid-sided hopper which prevented the release of dust during feeding and which, being detachable, could be refilled away from the rabbit rooms to minimize general atmospheric dust.     

Allometry between length and cross-sectional dimensions of the femur and tibia in Homo sapiens sapiens

Allometric equations relating length and cross-sectional geometric properties of the femur and tibia are generated using skeletal remains from three recent human population samples. Approximate isometry, or geometric similarity, is found both within and between samples. Cross-sectional areas scale to approximately length2, while second moments of area scale to approximately length4. It is shown that this is consistent with the maintenance of equivalent mechanical stress in long bones of different length under dynamic loadings in vivo. Other evidence indicates that bending and torsional loadings are more critical than axial loadings in the determination of lower limb bone cross-sectional dimensions.     

Intracellular distribution of molecular forms of acetylcholinesterase in rat brain and changes after diisopropylfluorophosphate treatment

The subcellular distribution of acetylcholinesterase activities was studied in the striatum and cerebellum of rat brain. The highest percentage of the enzyme activity was found in the crude synaptosomal (P₂) fraction, with striatum much higher than cerebellum. On sucrose density gradient centrifugation analyses all the particulate fractions (P₁, P₂, and P₃) showed a major peak of the 10 S form of acetylcholinesterase activity with very little activity of the 4 S form of the enzyme. The 10 S/4 S ratio was much higher in striatum than in cerebellum. In the soluble fraction (100,000g supernatant) the 10 S form was less than the 4 S form in the adult rat brain, but this was reversed in the 6-day-old rat brain. After diisopropylfluorophosphate administration the recovery of acetylcholinesterase molecular forms in various subcellular fractions differed at different recovery periods. These results indicate that the distribution of molecular forms of acetylcholinesterase in rat brain differs in various subcellular fractions, and also the pattern of distribution differs in different regions of the brain as well as in adult and developing brains.     

Schistosoma japonicum: disc electrophoretic protein patterns of the Japanese, Philippine, and Formosan strains

Soluble proteins of the Japanese, Philippine, and Formosan strains of Schistosoma japonicum were separated by disc electrophoresis using polyacrylamide gel columns. Differences between strains and sexes were investigated on the basis of R_f values of the bands, location of prominent peaks, quantitative comparisons of major bands, and overall densitometric profiles. With male extract, 29, 28, and 29, distinct bands were resolved for the Japanese, Philippine, and Formosan strains, respectively. Female extracts gave 31, 26, and 25 distinct bands for the Japanese, Philippine, and Formosan strains, respectively. Both qualitative and quantitative differences were found among the three strains and between sexes. The closest relationship of densitometric profile was between the Japanese and Formosan strains.