Novel non-indolic melatonin receptor agonists differentially entrain endogenous melatonin rhythm and increase its amplitude.

In this study we have examined the ability of melatonin and four synthetic melatonin receptor agonists to entrain endogenous melatonin secretion in rats, free running in constant darkness. The circadian melatonin profile was measured by trans-pineal microdialysis, which not only reveals the time of onset and end of production (phase), but also the amplitude of the rhythm. Exogenous melatonin given at the onset of subjective darkness (clock time 12 h) was effective to entrain endogenous melatonin production.

A microdialysis study on pineal melatonin rhythms in rats after an 8-h phase advance: new characteristics of the underlying pacemaker.

This study describes the use of the microdialysis technique to elucidate specific properties of the circadian pacemaking system in the hypothalamus, by measurement of melatonin production in the pineal gland. Melatonin has appeared to be a reliable marker of the pacemaker activity, which is influenced by the light/dark cycle. A phase shift in the light/dark cycle was applied to perturb the rhythm generating system.

Production, characterization and control of a Neisseria meningitidis hexavalent class 1 outer membrane protein containing vesicle vaccine.

An experimental serogroup B meningococcal vaccine was prepared from two genetically engineered strains; each expressing three different class 1 outer membrane proteins (OMPs) (PorA). The two strains expressed the subtypes P1.7,16;P1.

Exogenous melatonin entrains rhythm and reduces amplitude of endogenous melatonin: an in vivo microdialysis study.

The circadian rhythm of melatonin production was studied using on-line, in vivo microdialysis in the rat pineal gland. With this technique it was possible to record a pronounced melatonin rhythm with very high time resolution. Three phase-markers of the rhythm were calculated from the data, indicating increase (IT50), decrease (DT50) and amplitude of the rhythm.

Ferrous iron dependent nitric oxide production in nitrate reducing cultures of Escherichia coli.

L-Lactate-driven ferric and nitrate reduction was studied in Escherichia coli E4. Ferric iron reduction activity in E. coli E4 was found to be constitutive.