Search PubMed⌕ Search

Biomedical subjects

J Kaufman

Publications and source records attributed to J Kaufman.

At least 235 records · Page 13Linked to original sources
PubMed1975

Thermal oxidative decomposition studies of neoprene compositions.

Four neoprene compositions--uncured gum, known cured rubber, cable insulation, and hose conduit, the latter two used in underground mining--were subjected to thermal oxidative degradation under static and dynamic environments, and the volatile products were quantitated on a milligrams-per-gram basis. In a quiescent system at 370 degrees C, no glow was observed, the extent of oxidation was low, up to 84% of the chlorine content was evolved as hydrogen chloride, and the sulfur present was released largely in the form of carbon disulfide. Under more drastic conditions (higher temperatures and flowing air), glow occurred in several instances resulting in an increased production oxidation products as represented by CO2, COS, SO2, HCOOH, and CH3COOH, among others. Thermogravimetric investigations of the neoprene compositions show the first weight loss to correlate closely with hydrogen chloride evolution; furthermore, the use of thermogravimetric curves as means of meterial differentiation appears to offer a definite promise.

Air Pollution↗
PubMed1973

Inhibition of cellular protein synthesis by double-stranded RNA: inactivation of an initiation factor.

Inhibition of protein synthesis in rabbit reticulocyte lysates by double-stranded RNA is caused by the inactivation of IF-3, an initiation factor required for the recycling of ribosomes and for their binding to messenger RNA. The evidence for this is that (i) the inhibition can be overcome by addition of exogenous If-3; (ii) double-stranded RNA inactivates stoichiometric amounts of IF-3; (iii) double-stranded RNA forms a complex with IF-3; and (iv) double-stranded DNA, which lacks inhibitory activity, also binds to IF-3, but with a much lower affinity than double-stranded RNA. It is concluded that double-stranded RNA inhibits cellular protein synthesis by tightly complexing with IF-3. It is suggested that IF-3 normally recognizes a double-stranded region in messenger RNA.

Amino Acids↗
PubMed1972

Translational control of hemoglobin synthesis by an initiation factor required for recycling of ribosomes and for their binding to messenger RNA.

The continued recycling of ribosomes during protein synthesis in rabbit reticulocyte lysates at 37 degrees requires an initiation factor whose activity is rapidly lost in the absence of added heme. Partially purified factor (i) fully maintains the polysomes; (ii) inhibits the association of 40S and 60S ribosomal subunits into single ribosomes; (iii) promotes the quantitative entry of added 60S subunits into polysomes; (iv) allows the accumulation of ribosomal subunits, instead of single ribosomes, when initiation is blocked with aurin tricarboxylate; and (v) is absolutely required for the binding of globin messenger RNA to ribosomes.These properties suggest that this mammalian initiation factor functions analogously to bacterial IF-3. In addition, the translational control of globin synthesis by heme is exerted, directly or indirectly, through this factor.

Animals↗