Thermal preferences of wintering snails Planorbarius corneus (L.) exposed to lipopolysaccharide and zymosan.

Fever is regarded as a physiological response to infection both in endothermic and ectothermic animals. In ectotherms, fevers are achieved only behaviorally, and has been described in many vertebrates' and few invertebrates' groups. In snails only symptoms of reverse fever as a response to trematode invasion were found. Present work reports on the effects of two different pyrogens - lipopolysaccharide extracted from Escherichia coli (LPS), and zymosan - from Saccharomyces cerevisiae on the thermal behavior of wintering (studied during a winter season) specimens of the Planorbarius corneus (L.). Using the thermal gradient protocol we demonstrate that the individuals of this snail species responded with behavioral fevers to dosages of pyrogens. LPS injection to the surface of the snail's foot at a dose of 10 µg/g resulted in a significant increase in preferred temperature at 5h after injection. Similarly zymosan at a dose of 0.5 and 1.0 µg/g - caused fever at 8h and 9h respectively. Average temperature chosen by feverish animals after latency period reached 28.7±0.41 °C (LPS), 28.1±0.43 °C (zymosan 1.0 µg/g) or 25.5±0.33 °C (zymosan 0.5 µg/g). We conclude, therefore, that snails are capable of reacting with fever to selected pathogen associated factors, and P. corneus can be used as a model to study a behavioral fever phenomenon in invertebrate animals.

The involvement of NMDA and AMPA receptors in the mechanism of antidepressant-like action of zinc in the forced swim test.

Antidepressant-like activity of zinc in the forced swim test (FST) was demonstrated previously. Enhancement of such activity by joint administration of zinc and antidepressants was also shown. However, mechanisms involved in this activity have not yet been established. The present study examined the involvement of the NMDA and AMPA receptors in zinc activity in the FST in mice and rats. Additionally, the influence of zinc on both glutamate and aspartate release in the rat brain was also determined. Zinc-induced antidepressant-like activity in the FST in both mice and rats was antagonized by N-methyl-D-aspartic acid (NMDA, 75 mg/kg, i.p.) administration. Moreover, low and ineffective doses of NMDA antagonists (CGP 37849, L-701,324, D-cycloserine, and MK-801) administered together with ineffective doses of zinc exhibit a significant reduction of immobility time in the FST. Additionally, we have demonstrated the reduction of immobility time by AMPA receptor potentiator, CX 614. The antidepressant-like activity of both CX 614 and zinc in the FST was abolished by NBQX (an antagonist of AMPA receptor, 10 mg/kg, i.p.), while the combined treatment of sub-effective doses of zinc and CX 614 significantly reduces the immobility time in the FST. The present study also demonstrated that zinc administration potentiated a veratridine-evoked glutamate and aspartate release in the rat's prefrontal cortex and hippocampus. The present study further suggests the antidepressant properties of zinc and indicates the involvement of the NMDA and AMPA glutamatergic receptors in this activity.

Preliminary experience with Mitolactol in advanced tumors of the orofacial region and the larynx.

Mitolactol (Dibromodulcitol "DBD"; RlobromolR) an alkylating agent was applied in a clinical series of twenty advanced or relapsing cases of malignant tumors of the orofacial region and the larynx. It was administered orally in a mean total dose of 127 mg/kg/30 days. In 45% of the patients the treatment resulted in a diminution of tumors by more than 50%, with remission lasting 1-4 months. 30% of the patients responded by a retreat of the tumor volume smaller than 50%, while no therapeutic effect was noted in 25% of the patients, or the objective finding proved to be worse. Subsequent radiotherapy improved the results, and remissions which followed combined chemo-radiotherapy were prolonged up to 9 months. The effect of DBD treatment proved better in orofacial than in laryngeal carcinoma.