Isolation and comparative mapping of a human chromosome 20-specific alpha-satellite DNA clone.

We have isolated and characterized a human genomic DNA clone (PZ20, locus D20Z2) that identifies, under high-stringency hybridization conditions, an alphoid DNA subset specific for chromosome 20. The specificity was determined using fluorescence in situ hybridization. Sequence analysis confirmed our previously reported data on the great similarity between the chromosome 20 and chromosome 2 alphoid subsets. Comparative mapping of pZ20 on chimpanzee and gorilla chromosomes, also performed under high-stringency conditions, indicates that the alphoid subset has ancestral sequences on chimpanzee chromosome 11 and gorilla chromosome 19. However, no hybridization was observed to chromosomes 21 in the great apes, the homolog of human chromosome 20.     

RESPONSE OF IPS GRANDICOLLIS (EICHHOFF) ADULTS (COLEOPTERA;SCOLYTIDAE) TO SITES IN BARK INITIATED BY OTHERS OF THE SAME SPECIES

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Dispersing males and females of Ips grandicollis , whether mated or virgin, initiated galleries on experimental logs held in a naturally infested P. radiata plantation. A few females initiated galleries despite the presence of adjacent male-initiated galleries. Males responded to logs bearing females by entering 41% of the female-initiated galleries. The pattern of entry of these males differed depending on whether the entrance to the female-initiated gallery was blocked by frass or not. The findings of this study has led to interesting speculations about the behaviour and biology of this species.     

Tissue lipids in experimental calcium oxalate lithiasis and the effect of DL alpha-lipoic acid.

The function of DL alpha-lipoic acid (6,8-thioctic acid) as a prosthetic group in the oxidative decarboxylation of alpha-keto acids, pyruvate and alpha-ketoglutarate in mitochondria is well known. Its role is well extended to certain reactions in lipid biosynthesis. In addition, lipoic acid has been shown to prevent the induced precipitation of calcium oxalate crystals in the renal tissues of laboratory animals. Here, the effect of alpha-lipoic acid was studied, on altered tissue lipid levels manifested during experimental renal lithiasis. Raised tissue cholesterol, triglyceride and low phospholipid levels were some of the striking significant observations made in calculogenic rats. Lipoic acid treatment reduced tissue cholesterol and triglyceride levels significantly and raised phospholipids. The alterations may have a bearing in relation to calcium oxalate stone formation.