A new tripeptide, Pol 509, influences biochemical events associated with antigen presentation efficiency of PPD-specific EBV-B cells.

A synthetic tripeptide (pGLU-LEU-TRP-OCH3) Pol 509, derived from snake venom, was studied directly by analyzing the interactions with synthetic lipid bilayers using NMR spectroscopy. Functional studies were also performed by measuring the effects: i), on early biochemical events (adenyl cyclase and phospholipase C activation products), intermediate (surface Ag expression) and late (DNA synthesis) parameters following B-cell activation elicited by PPD-linkage to specific membrane Ig; and ii), on the presentation of PPD to Ag-specific T-cell lines. Comparative experiments using PMA and IFN-gamma were also performed.

[Mycobacterium tuberculosis. From the gene to the diagnosis].

Pulmonary tuberculosis still in on the list of the world major health problems. Tuberculosis has not been eradicated yet, from developing countries. Furthermore, its incidence is increasing in the industrialized world, due to the human immunodeficiency virus (HIV) epidemic.

Effect of glucocorticoids on the development of suppressive activity in human lymphocyte response to a polysaccharide purified from Candida albicans.

The action of glucocorticoids on the proliferative response of human lymphocytes stimulated in vitro by MPPS has been investigated. The effect of Dex was dependent on the time of steroid addition to the cultures. Dex added at the beginning of the culture period inhibited, cell proliferation and IL 1/IL 2 synthesis, although not completely.

[Adaptability of the Gompertz equation to the growth kinetics of a transplantable experimental tumor].

We have carried out a study on the growth kinetics of a solid rat reticulosarcoma, by making use of the Gompertz equation. This approach is not sufficiently valid for the groups as a whole, but furnishes useful information when applied to individual tumors. In fact the values for relative (1/V dV/dt) and absolute (dV/dt) velocities calculated for individual tumors by making use of this equation, exhibit greater significance and consistency with respect to tumor-host integration.

Mitochondrial DNA of Yoshida ascites tumour cells. Physicochemical properties and biological function.

Mitochondrial DNA from Yoshida A.H. 130 cells, has been characterized by determination of the buoyant density by CsCl equilibrium density gradient centrifugation and the thermal denaturation and renaturation behaviour.