Tryptoline formation by a preparation from brain with 5-methyltetrahydrofolic acid and tryptamine.

An enzymatic preparation from human brain converts tryptamine to tryptoline (9H-1,2,3,4-tetrahydropyrido[3,4-b]indole) in the presence of 5-methyltetrahydrofolic acid. Similarly, N-methyltryptamine and 5-hydroxytryptamine yield 1-methyltryptoline and 5-hydroxytryptoline, respectively. Neither in vitro nor in vivo formation of these compounds by human tissues has been described.

[A handbook project designed to sensitize the illiterate population to orodental preventive care]. / Projet de manuel destiné à sensibiliser les populations analphabetes à la prévention bucco-dentaire.

In many poor countries, the number of "illiterate people" is often very high. In order to sensibilize these populations to dental caring, the authors propose a series of frames based on the mental association with their traditional lifestyles. With only ten series of drawings they deal with: morphology, hygiene, cares, smile, functional and aesthetic importance of mouths and teeth. To conclude, the authors insist on the fact that this way of sensibilisation is all the more efficient that it is beyond dialects, ethnic groups and boundaries.

[Dental surgery in Lebanon: studies and professional demography]. / Chirurgie dentaire au Liban: les études et la démographie professionnelle.

Lebanon (about 4,000,000 inhabitants) shows us a surprising dental professional demography. University diplomas to practice dentistry come from 73 different foreign countries. The concentration of dental offices in and around Beirut explains disharmonies of the sanitary map. The studies of these particularities set up the frame of this work. Some answers are proposed.

The effects of alcohol on cyclic AMP in mouse brain.

Detailed analysis of the dose-response and time-course relationship of ethanol to changes in adenosine 3',5'-cyclic monophosphate (cAMP) content of mouse brain revealed several patterns of response, including both decreases and increases depending on brain area. Whole-brain cAMP content was decreased with ethanol injection at all doses (0.4-3.2 g/kg), and reflected the decreased levels in the cortex. The subcortical and cerebellar levels underwent a significant increase with doses of 1.6 and 3.2 g/kg, respectively. In all brain areas, significant changes in cAMP content occur within 10 min after ethanol injection; elevated levels persist for 30-60 min in the subcortex and cerebellum, but remain significantly depressed in the cortex at 3 h. These dynamic changes in brain cAMP levels after ethanol administration may reflect variations in neurotransmitter activity.

Rat-liver cholesterol 7 alpha-hydroxylase. 1. Development of a new assay based on the enzymic exchange of the tritium located on the 7 alpha position of the substrate.

A new assay is described to measure the activity of cholesterol 7alpha-hydroxylase and compared to the conventional 14C method used by other investigators. This method is based on the mechanism of the enzymic hydroxylation, i.e. a direct and stereospecific substitution of the 7alpha-hydrogen by a hydroxyl group. [7alpha-3H]Cholesterol is incubated at 37 degrees C and in the presence of molecular O2, in a medium buffered by postassium phosphate at pH 7.4 and containing liver microsomes (or 9000 X g supernatant), NADPH, MgCl2 and cysteamine. Tween-80 (1.5 mg/ml) is used to introduce enough substrate (300 muM) in the incubation mixture to saturate the enzyme (Km = 100 muM). Under these conditions the tritiated water released into the incubation medium reflects accurately the enzymic activity. The results obtained with this method are similar to the one obtained with a [4-14C]cholesterol technique (r = 0.96; P less than 0.001). The main advantage of the [7alpha-3H]cholesterol method is a complete independence from further metabolism of the first enzymic product, the 7alpha-hydroxycholesterol, the tritiated water representing the entire cholesterol 7alpha-hydroxylase activity.

Rat-liver cholesterol 7alpha-hydroxylase. 3. New results about its circadian rhythm.

The establishement of the circadian rhythm of cholesterol 7alpha-hydroxylase activity requires protein and RNA synthesis. The spontaneous decrease of the enzymic activity, at the end of the night, allows us to evaluate a half-life time of about two hours. The half-life time goes up to about four hours when the enzymatic activity decay is measured following cycloheximide administration. This difference suggests that an active mechanism is involved in the control of the enzyme degradation. The daily variation of the enzyme activity is regulated via the hypothalamo-hypophysis-adrenal axis. At the cellular level glucocorticoids are the most likely responsible agent. The hepatic cholesterol 7alpha-hydroxylase variations always parallel the plasmatic corticosterone concentration fluctuations, the latter being by far the most important adrenocortical excretion product. These two rhythms are modified in a similar manner under different physio-pathological conditions, such as the inversion of lighting in the animal room or the inversion of feeding time. Of these two parameters, the moment of food intake is the most important and accounts for the synchronisation of the rhythm in the animals. The rhythm is retained after several days of starvation but its amplitude decreases and the individual variations among the animals increase significantly at each time point.

Genetic determination of aggressive behavior and brain cyclic AMP.

Inbred mouse strains exhibit differences in brain cyclic AMP concentrations. In two mouse strains, we have shown that both the tendency for aggressive attack and high brain cyclic AMP content are inherited as recessive traits and that these traits maintain a close association in segregating generations.