Insulin receptors: Structure and function

Summary and conclusions The recent characterization of the human insulin receptor structure and its intrinsic tyrosine kinase activity represent major advances in our understanding of the mechanism of insulin action. It is reasonable to think that the insulin-induced autophosphorylation and activation of its receptor kinase represent an important event in the action of insulin on cell metabolism and growth. The fundamental research reviewed may be followed by the discovery of molecular receptor defects in clinical syndromes of insulin resistance.     

Anchorage-dependent culture of line 10 guinea-pig hepatoma cells

Summary A simple method for the anchorage-dependent culture of line 10 guinea-pig hepatoma cells is described.     

Germline mosaicism and Duchenne muscular dystrophy mutations

Duchenne muscular dystrophy (DMD) is a severe X-linked neuromuscular disease with an incidence of approximately 1 in 3,500 newborn boys. The DMD locus has a high mutation frequency: one third of the cases is thought to result from a new mutation. Linkage studies using probes to detect restriction fragment length polymorphisms and DNA deletion studies have greatly improved DMD carrier detection and prenatal diagnosis. Here we report on two families in which a pERT87 (DXS164) deletion was transmitted to more than one offspring by women who showed no evidence for the mutation in their own somatic (white blood) cells. We also show that the deletion in both siblings in one of the families is identical, indicating that the deletion must have occurred during mitosis in early germline proliferation, leading to a germline mosaicism. This phenomenon may turn out to be a major factor contributing to the induction of DMD mutations, and has important implications for the counselling of DMD families.     

Molecular forms of dopamine beta-hydroxylase in rat superior cervical ganglion and adrenal gland

Summary Dopamine beta-hydroxylase (DBH) enzyme activity was associated in rat superior cervical ganglion with tetrameric DBH-A (294,000 D) and dimeric DBH-B (147,000 D) and in rat adrenal gland with DBH-A and a novel molecular form of DBH, defined as DBH-C, with a molecular weight of 125,000 D. Pretreatment of the rats with cycloheximide markedly reduced DBH activity without altering the molecular heterogeneity.     

Chemotherapy of parasite infections.

Although several good antiparasitic agents are available, new drugs are needed for the treatment of diseases such as chloroquine-resistant malaria, Chagas' disease, leishmaniasis and filariasis. The 'semirational approach' should be the basis for their synthesis.     

Métaplasie épidermoïde de l'épithélium mammaire humain,en culture organotypique à long-terme

Summary Squamous metaplasia of the mammary epithelium was observed in human breast tissue maintained in long-term organ culture. The phenomenon occurred only in the synthetic medium 199 with Earle's salts. Insulin and/or glucose enrichment enhanced its occurrence.