Long-term local and distal increases in tryptophan hydroxylase activity following intracerebral kainic acid injections in the rat

The administration of kainic acid (1–2 μg) into the right striatum of adult rats resulted in a marked local increase in tryptophan hydroxylase activity (+ 54–106%). This change was significant as soon as on the second day after the treatment and persisted for at least 12 days. In addition, long-lasting elevations of tryptophan hydroxylase activity were also observed in the anterior raphe area, septum and ipsilateral hippocampus and cerebral cortex. In contrast, the intrahippocampal injection of kainic acid (1 μg) induced a long-term increase in tryptophan hydroxylase activity only in the injected structure. In all cases, the changes in tryptophan hydroxylase activity were associated with significant increases in the V_max of the enzyme with no alteration of its apparent affinities for tryptophan and the pterin cofactor. Studies of the sensitivity of tryptophan hydroxylase from control and from kainic acid-treated rats to in vitro activating conditions (Ca⁺-dependent phosphorylation, partial trypsinization, exposure to sodium dodecyl sulfate) suggest that the intrastriatal injection of the neurotoxin induced a long-lasting activation of the enzyme.These findings indicate that intracerebral injections of kainic acid may be a valuable approach to explore further the mechanisms controlling tryptophan hydroxylase activity in vivo.     

Measles vaccination in severely malnourished Sudanese children

The clinical and serological responses to attenuated measles virus vaccine were compared in 35 severely malnourished and 35 well-nourished children. A third group of severely malnourished children, who received an injection of vitamin B12, served as controls. The children were observed for three weeks following vaccination. Paired sera were collected from each child before and after administration of the vaccine or vitamin B12 and measles antibody titres were estimated using HAI technique. The malnourished children who received measles vaccine developed higher fever of longer duration and had more lower respiratory tract disease than the other two groups but had fewer skin rashes than the well-nourished group. Sero-conversion rates were 96% had 92.6% in the malnourished and well-nourished vaccinated children, respectively. Antibody titres were lower in children who had marasmic/kwashiorkor than in the marasmic children.     

Relationship between changes in corneal configuration and thickness.

The experiment was conducted on a sample of 26 subjects including both males and females and a control group of five. Their mean age was a little over 24 years. Corneal thickness and configuration were measured before and after the subjects had been wearing rigid and flexible contact lenses for three hours; measurements were also taken on control subjects at two different sessions, before and after a three-hour period. The statistical analysis showed a low but significant correlation between corneal thickness and corneal shape.     

Novel synthesis of 2-substituted aminobenzimidazoles from thiourea derivatives.

The use of different alkyl halides as effective cyclodesulfurizing agents was thoroughly studied. N-phenyl-,N'-[o-aminophenyl]-thiourea when treated with different alkyl halides gave rise to 2-phenyl-aminobenzimidazole. The optimum conditions for such cyclodesulfurization reaction were established by using eight equivalents of the alkyl halide, ethyl alcohol as solvent, and 8 h reflux. The reaction was also successfully applied to N-o-tolyl (benzyl or n-butyl)-N'-[o-aminophenyli1-thioureas to give rise to the corresponding 2-substituted aminobenzimidazoles.