Maternal Influences on Feeding and General Activity in Domestic Chicks

The aim of this study was to determine if and how the presence of a hen influences the behaviour of chicks and, more precisely, their food preferences. We observed two types of young, brooded and non‐brooded chicks in the presence of three different food types. Results revealed that brooded chicks performed more locomotion and more sustained feeding activities than non‐brooded chicks. Moreover, brooded chicks had different preferences from non‐brooded chicks and very clearly followed their mother's preferences. We concluded that social facilitation and local enhancement could play a significant role in determining the importance of feeding activities and preferences of brooded chicks.     

In vitro and in vivo chromosomal aberrations induced by megazol

With the re-emergence of Human African Trypanosomiasis (HAT) on the one hand, which are increasingly resistant to current therapies, and the stage-dependent effectiveness or even the prohibitive cost of these therapies on the other hand, megazol, a 5-nitroimidazole thiadiazole highly active against various trypanosomal species, was assessed for its genotoxic potential. Very little information has become available until now. Two batches of megazol were provided by two different suppliers: Far-Manguinhos, a part of the Fiocruz foundation, under the Brazilian Minister of Health, and Delphia, a French company. These two batches, obtained by different synthetic routes, were studied by means of the in vitro micronucleus assay on L5178Y mouse lymphoma cells, in its microscale version. Both batches of magazol displayed a strong genotoxic activity in this screening assay. A second batch from Delphia was then investigated by use of two tests, i.e. the in vitro metaphase analysis with human lymphocytes and the in vivo micronucleus test in rat bone-marrow. Megazol was shown to be a potent inducer of in vitro and in vivo chromosomal aberrations. Although megazol is a potent trypanocidal agent and is orally bio-available, its toxicity dictates that it should not be developed further for the treatment of HAT and Chagas disease. All development work has therefore been discontinued.     

Nucleotide sequence of the woodchuck hepatitis virus surface antigen mRNAs and the variability of three overlapping viral genes

A cDNA library was constructed from the liver of a woodchuck chronically infected with woodchuck hepatitis virus (WHV). A clone, pWS23, encompassing the entire surface and X genes of WHV was isolated. Comparison of the complete nucleotide (nt) sequence of pWS23 with those of genomic DNAs from two different WHV isolates showed that it contained a nearly full-length copy of the major mRNA encoding the viral surface antigen (5 mRNA). It was colinear with the WHV genome over 1858 nt and terminated 22 nt downstream from the variant polyadenylation signal within the core gene. Evidence for heterogeneity of the 5′ -terminal region of the S mRNA came from direct sequencing of the 5′ extremities of 20 cDNA inserts, similar to that of pWS23, isolated from a second cDNA library of the same woodchuck liver. In agreement with previous mapping studies of hepadnaviruses, two main initiation regions of S mRNA were localized 27–30 nt upstream and 22–49 nt downstream from the pre-S2 initiation codon. Further analysis of the amino acid sequences of the surface, polymerase and X genes of WHV showed a high conservation among three WHY isolates and a similar distribution of conserved and variable regions in woodchuck and human hepatitis B viruses.