Loss of a Harvey ras allele in sporadic Wilms' tumour

Genomic changes within chromosome band 11p13 appear to have a role in the initiation of Wilms' tumour. The human Harvey ras oncogene, c-Ha-ras 1, has been located by Jhanwar et al. immediately adjacent to this region at band 11p14 .1, although several groups have assigned the gene more distally at band 11p15 . We have examined tumour DNA from two cases of sporadic Wilms' tumour, and report here that in both cases one of the two constitutional c-Ha-ras 1 alleles was absent. One tumour had a reciprocal translocation between the short arm of chromosome 11 (at band 11p13), and the long arm of chromosome 12, with no visible loss of chromosomal material. The loss of a c-Ha-ras 1 allele in association with this translocation indicates that a submicroscopic deletion had occurred. The resulting hemizygosity may have had a role in tumour initiation. Our results indicate that the c-Ha-ras 1 gene and the 'Wilms' tumour locus' may be in close proximity. It would, therefore, be premature to exclude the possibility that these two sites are functionally related.     

Tests of the helix dipole model for stabilization of alpha-helices

Charged groups play a critical role in the stability of the helix formed by the isolated C-peptide (residues 1-13 of ribonuclease A) in aqueous solution. One charged-group effect may arise from interactions between charged residues at either end of the helix and the helix dipole. We report here that studies of C-peptide analogues support the helix dipole model, and provide further evidence for the importance of electrostatic interactions not included in the Zimm-Bragg model for alpha-helix formation.     

Effect of different bathing media on the short-circuit current across the intestine of the rat and guinea-pig

Summary The changes in short-circuit current occurring when one or both solutions bathing the intestine of rat or guinea-pig mounted in flux chambers were recorded. The results with the guinea-pig can be explained in terms of diffusion potentials arising from the ionic replacements, and an electrogenic sodium pump, sensitive to ouabain, in the contraluminal membrane of the cell. In the rat, the situation is more complicated, and the enterocyte probably possesses an electrogenic sodium pump in the brush-border membrane.     

The lambda phage att site: functional limits and interaction with Int protein

Site specific integrative recombination of bacteriophage lambda involves unequal partners. The minimal phage att site is composed of approximately 240-base pairs and four distinct binding sites for Int protein, at least three of which are crucial for function. This 'donor site' recombines efficiently with a smaller 'recipient site' that lacks the extensive interactions with Int protein.     

Effects of thalidomide on the skeleton of the rat foetus

Zusammenfassung Nach Thalidomidverabreichung an trächtigen Ratten fanden wir Fruchtresorption und Anomalien am fünften Brustbeinkern der Föten. Weitere ergänzende Skelettuntersuchungen ergaben, besonders bei mittelgrossen Thalidomidgaben, Verknöcherungs-störungen an den Halswirbelkörpern. Andere Skeletteile zeigten keine Thalidomid-abhängigen Entwicklungsvariationen.     

Survival of embryonic limb bud transplants in snapping turtles

Résumé Des membres furent transplantés chez des tortues embryonnaires deChelydra serpentina en combinaisons allogénique et xénogénique. Ces greffes survivaient longtemps, mais étaient usuellement rejettées de façon chronique.

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Supported by U.S. Public Health Service Grants No. 8 RO1 HD 03484 and No. 1 FO2 AM 33,123 from the National Institutes of Health.     

Effect of biogenic amines on γ-amylase (acid α-glucosidase)

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