No detectable bioeffects following acute exposure to high peak power ultra-wide band electromagnetic radiation in rats

A wide range assessment of the possible bioeffects of an acute exposure to high peak power ultra-wide band (UWB) electromagnetic radiation was performed in rats. The UWB-exposure consisted of 2 min of pulsed (frequency: 60 Hz, pulse width: 5-10 ns) UWB (bandwidth: 0.25-2.50 GHz) electromagnetic radiation. Rats were examined using one of the following: 1) a functional observational battery (FOB); 2) a swimming performance test; 3) a complete panel of blood chemistries; or 4) determination of the expression of the c-fos protein in immunohistologically-stained sections of the brain. No significant differences were found between UWB- or sham-exposed rats on any of the measured parameters.     

Modification of the "kindling" method for obtaining experimental status epilepticus in rats

Taber et al. (1977) introduced new model of epilepsy to obtain experimental status epilepticus in mice, through a modification of the kindling method (Goddard et al. 1969). The aim of this paper is to report the effect of Taber's modification on a new animal specie (rats). Bipolar, twisted steel electrodes were stereotaxically implanted into the CA1-CA3 regions of the dorsal hippocampus. After one week the animals received 2 h stimulation sessions, one stimulus per minute, during which a sustained electrographical and behavioral seizures were induced. Different patterns of electrographical discharges as well as tonic-clonic convulsions were observed. The animals which were submitted to 3 stimulating sessions respectively 7, 14 and 21 days after surgery showed an increase in the epileptic activity. This has been interpreted as a plastic neural modification of the hippocampus similar to that observed during learning and memory consolidation. In comparison to other inducing kindling methods this one permits a more rapid elicitation of the phenomenon. For this reason this method will provide a good epilepsy model for the study of anticonvulsant drugs and basic mechanisms involved in the epileptic activity.     

1st instance of the absence of an erythrocyte membrane protein (band 4(1)) in a case of familial elliptocytic anemia

In four members of a family presenting hereditary elliptocytosis erythrocytes were studied, membranes were extracted and proteins were analysed by gel electrophoresis in a polyacrylamide gradient. In one of the patients suffering from severe haemolytic anaemia successfully treated by splenectomy, an almost complete deficiency in band 4(1) was discovered. Endogenous protein kinase activities revealed the absence of radioactivity of band 4(1) in the proband, a result not modified by cAMP. The kinase activity was normal in the parents, which confirms the almost complete absence of protein 4(1) seen in the stained gel of the proband. A moderate increase in the phosphorylation of band 3 was observed in all the members of this family. Deformability was measured by a visco-diffractometric method (Ektacytometry) in a medium of low viscosity (11 cp at 22 degrees C), allowing the recording of curves characteristic of elliptocytosis and revealing a markedly reduced deformability index (DI). At low shear stress, elliptocytes were oriented perpendicular to the flow (a result common to all elliptocytosis). In the proband several years after splenectomy, the DI was extremely reduced at high shear stress, which can be explained by the simultaneous presence of elliptocytes, schizocytes and spherocytes. A more detailed comparative study of the proteins of the various members of the family could lead to more precise information on the possible role of band 4(1) as a linkage protein maintaining the erythrocyte membrane stability.     

Maternal-foetal interaction, antibody formation, and metabolic response in mice immunized with pneumococcal polysacharides

The maternal transfer of pneumococcal polysaccharides to foetus, as well as the antibody formation and metabolic response were studied in mice exposed to pneumococcal polysaccharides during pregnancy. Type 19 and type 57 pneumococcal polysaccharides display cross-placental transfer to foetus. These polysaccharides also transfer through mother's milk to neonates. Maternal immunization of type 19 polysaccharide during pregnancy induced higher antibody formation in the offspring than the group from non-immunized mothers. Young mice, which received a second dose of polysaccharide at 2 weeks of age, showed a higher antibody response than those which did not receive polysacharide. Treatment of mothers with anti-lymphocyte serum, following by administration of polysaccharide, significantly increased the neonatal immune response to the polysaccharide. Treatment of the mother with a high dose of type 19 or type 57 polysaccharide did not cause significant changes in neonatal growth and organ weights. The offspring from mothers treated with high doses of these polysaccharides did not exhibit abnormalities in chemical contents of their tissues.