After insulin binds

Three recent advances pertinent to the mechanism of insulin action include (i) the discovery that the insulin receptor is an insulin-dependent protein tyrosine kinase, functionally related to certain growth factor receptors and oncogene-encoded proteins, (ii) the molecular cloning of the insulin proreceptor complementary DNA, and (iii) evidence that the protein tyrosine kinase activity of the receptor is essential for insulin action. Efforts are now focusing on the physiological substrates for the receptor kinase. Experience to date suggests that they will be rare proteins whose phosphorylation in intact cells may be transient. The advantages of attempting to dissect the initial biochemical pathway of insulin action include the wealth of information about the metabolic consequences of insulin action and the potential for genetic analysis in Drosophila and in man.     

Replicative and cytopathic potential of HTLV-III/LAV with sor gene deletions

The genome of the human T-lymphotropic virus type III (HTLV-III/LAV) has the potential to encode at least three polypeptides in addition to those encoded by the gag, pol, and env genes. In this study, the product of the sor (short open reading frame) region, which overlaps the 3' end of the pol gene, was found to be a protein with a molecular weight of 23,000. An assay was developed for testing the ability of cloned HTLV-III proviruses to produce viruses cytopathic for T4+ lymphocytes. In the cell line used, C8166, neither the HTLV-III sor gene product nor the complete 3'-orf gene product were necessary for the replication or cytopathic effects of the HTLV-III.     

Carbon dioxide sensitivity in mosquitoes infected with sigma, vesicular stomatitis, and other rhabdoviruses

Carbon dioxide, usually an innocuous narcotic for insects, kills mosquitoes infected with rhabdoviruses. Such toxicity was originally observed in Drosophila harboring a hereditary virus, sigma, and has been considered unique to Drosophila. The new findings support the possibility that insects with piercing and sucking mouthparts harbor similar hereditary viruses and transmit some of them to vertebrates or plants.     

Location of the trans-activating region on the genome of human T-cell lymphotropic virus type III

The retrovirus involved in acquired immune deficiency syndrome (HTLV-III/LAV) contains a region that is necessary for stimulation of gene expression directed by the viral long terminal repeat. This region is located between nucleotides 5365 and 5607, immediately 5' to the envelope gene. A doubly-spliced message containing this region could encode an 86-amino acid protein with structural features similar to those of nucleic acid-binding proteins.     

Major glycoprotein antigens that induce antibodies in AIDS patients are encoded by HTLV-III

Antibodies from the serum of patients with the acquired immune deficiency syndrome (AIDS) or with the AIDS-related complex and from the serum of seropositive healthy homosexuals, recognize two major glycoproteins in cells infected with human T-cell lymphotropic virus type III (HTLV III). These glycoproteins, gp160 and gp120, are encoded by the 2.5-kilobase open reading frame located in the 3' end of the HTLV-III genome, as determined by amino terminus sequence analysis of the radiolabeled forms of these proteins. It is hypothesized that gp160 and gp120 represent the major species of virus-encoded envelope gene products for HTLV-III.     

Sulfuric Acid droplet formation and growth in the stratosphere after the 1982 eruption of el chichon

The eruption of El Chichón Volcano in March and April 1982 resulted in the nucleation of large numbers of new sulfuric acid droplets and an increase by nearly an order of magnitude in the size of the preexisting particles in the stratosphere. Nearly 10(7) metric tons of sulfuric acid remained in the stratosphere by the end of 1982, about 40 times as much as was deposited by Mount St. Helens in 1980.     

Ultrafast X-ray Pulses from Laser-Produced Plasmas

A high-temperature plasma is created when an intense laser pulse is focused onto the surface of a solid. An ultrafast pulse of x-ray radiation is emitted from such a plasma when the laser pulse length is less than a picosecond. A high-speed streak camera detector was used to determine the duration of these x-ray pulses, and computer simulations of the plasmas agree with the experimental results. Scaling laws predict that brighter and more efficient x-ray sources will be obtained by the use of more intense laser pulses. These sources can be used for time-resolved x-ray scattering studies and for the development of x-ray lasers.