Effect of splenectomy on the in-vitro migration inhibition response to sheep erythrocytes in the lizard,Calotes versicolor

Summary Splenectomy completely erased the PFC response to SRBC in lizards. In contrast, it has very little effect on the degree of MI to all doses ranging from 10⁴ to 10⁹, excepting the lowest dose, 10³ SRBC.Supported by PL-480 (NIH) research grant, No. 01-077.Grateful to Madurai University for the award of Studentship during the tenure of the work and to Dr P. W. Askenase for the gift of capillaries used in this study.     

The origin,diversity, and structure function relationships of insect luciferases

Luciferases are the enzymes that catalyze the reactions that produce light in bioluminescence. Whereas the oxidative mechanism which leads to light emission is similar for most luciferases, these enzymes and their substrates are evolutionarily unrelated. Among all bioluminescent groups, insects constitute one of the most diverse in terms of biochemistry. In the fungus-gnats (Mycetophilidae: Diptera), for example, bioluminescence is generated by two biochemically distinct systems. Despite the diversity, investigations on insect luciferases and biochemistry have been conducted mostly with fireflies. The luciferases from the related phengodid beetles, which can produce green to red bioluminescence using the same chemistry as firefly luciferases, have been recently investigated. Beetle luciferases originated from ancestral acyl-CoA ligases. Present data suggest that conserved motifs among this class of ligases are involved in substrate adenylation. The three-dimensional structure of firefly luciferase was recently solved and mutagenesis studies have been performed identifying putative residues involved in luciferin binding and bioluminescence color determination in several beetle luciferases. The knowledge gained through these studies is helping in the development of useful reporter gene tools for biotechnological and biomedical purposes. Received 4 March 2002; received after revision 13 May 2002; accepted 21 May 2002     

Effect of lysine and threonine deficiency on the endogenous cholesterol content of rat plasma and liver

Riassunto È stato studiato l'effetto di diete ipoproteiche e isoazotate carenti e supplementate in lisina e treonina sul contenuto in colesterolo del fegato e del plasma.La carenza di aminoacidi essenziali induce negli animali più elevati livelli di colesterolo nel fegato, mentre diminuisce il colesterolo del plasma.In queste condizioni il ratto dimostra un comportamento simile all'uomo.

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Supported by grant from Consiglio Nazionale delle Ricerche, Roma.