Chromosome breakage induced by alkyl-alkane-sulfonates under different physical treatment conditions

A detailed study of chromosome breakage induced by three alkane sulfonates, which differ in chemical structure, functionality and reaction mechanism has been made in barley under different treatment conditions of temperature and hydrogen ion concentration. This study has indicated that, (i) the frequency and the types of chromosome breakage, at mitosis and meiosis, indicate certain qualitative and quantitative differences between the biological action of these three chemicals, (ii) the temperature of the treatment solution profoundly influences the frequency of chromosome breakage — a high frequency of breakage is observed at higher temperature, (iii) the effect of pH, though not very significant, is evident from the production of appreciably low frequency of breakage at alkaline pH for a given dose of chemical, (iv) by appropriate manipulation of treatment conditions, increase or decrease in the frequency of chromosome breakage can be accomplished to a considerable extent, (v) the qualitative and quantitative differences observed with respect to chromosoma breakage reflect the differences in the mode of biological action of these agents.     

Physicochemical and biological properties of glycoproteins isolated from the plasma of different species of animals

1. Glycoproteins were isolated from the plasma of sheep, goat, cow, buffalo and monkey. They were homogeneous by electrophoresis; on ultracentrifugation, a faster-sedimenting fraction, to an extent of 5–8% only, was observed in each case. 2. Similar physical properties were exhibited by these glycoproteins and they each have a molecular weight of about 105000. 3. In chemical composition, differences have been observed and the glycoproteins can be classified into three groups: (a) sheep and goat glycoproteins; (b) cow and buffalo glycoproteins; (c) monkey glycoprotein. Glucose, galactosamine and N-terminal amino acid were absent from these proteins. 4. These glycoproteins were trypsin inhibitors and prolonged the clotting time of plasma.     

Antibodies specific for VB8 receptor peptide suppress experimental autoimmune encephalomyelitis.

Recent studies from our laboratory have shown, for the first time, that a synthetic peptide from that TCR VB chain used preferentially by encephalitogenic T cells induced the formation of protective, MHC class I-restricted T cells and prevented the development of EAE in Lewis rats. In this report we 1) demonstrate that immunization with the TCR-VB8-39-59 peptide generated peptide-specific antibodies that protect against experimental autoimmune encephalomyelitis induced by either of the two distinct encephalitogenic epitopes of basic protein, and 2) characterize the production and biologic functions of rat and rabbit antibody responses to the TCR peptide. The antibodies in both species increased in titer over time, were highly specific for the immunogen by direct reaction and inhibition assays, stained only VB8+ T cells, and suppressed clinical signs and to lesser extent the number of histologic lesions of experimental autoimmune encephalomyelitis mediated by VB8+ T cells. Coupled with our previous work, these results indicate that both humoral and cellular responses to the TCR-VB8-39-59 peptide can contribute independent immunoregulatory effects on encephalitogenic T lymphocytes that use common V region genes in response to epitopes of myelin basic protein.