Responses to dose of 100 and 200 CCA units of a trivalent A/texas, A/USSR, and B/Hong Kong inactivated whole-virus vaccine produced by the Institut Armand-Frappier were evaluated in 667 adults volunteers in good health. No severe symptoms or clinical signs were observed. Temperature, mean systemic, reaction index and clinical signs in general were significantly higher among recipients of the larger dose of vaccine. No relationshop was noted between reactofenicity and serologic response. The presence of preexisting antibodies did not decrease the reactogenicity except in the case of A/USSR in the 26-50 age group. fourfold or greater increasees in titre occurred in nearly 100% of 249 seronegative recipients of A/Texas, irrespective of dose. Imn 274 seronegative recipients of A/USSR, such increases occured in 42% of those given 100 CCA units and in 67.8% in volunteers receiving 200 CCA units. In 230 seronegative recipients of B/Hong Kong, such increases occurred in 88.6% of those injected with 100 CCA units and 95.2% in those gfiven 200 CCA units. Seronegative subjects of 26 years of age and older had a better serologic response than those aged 18-25 with each dose of the A/USSR strain but there were no age differences in the response to the A/Texas and B/Hong Kong strains. The serologic response to 200 CCA units was significantly higher for the A/USSR strain in all age groups and for the B/Hong Kong strain in subjects aged 18-25.

Histamine was measured in the plasma, liver, and thymus of male rats fed a magnesium-deficient diet for 65 days. Histological study of the thymus was also performed. Histamine levels in plasma and tissue increased rapidly and reached a maximum after 10 days of deficiency. Later on, the level of histamine in deficient animals decreased and fluctuated but was usually higher than in the controls. One rat killed after 60 days of deficiency showed a very large thymus, weighing 1.8 g, which extended into the thoracic cavity. Histological study revealed a complete replacement of the normal thymic cells by large basophilic lymphocytes invading the neighboring organs including the heart muscle. The tumor was transplanted successfully in normal rats receiving a well-balanced diet. Another smaller tumor was found in an animal killed at 65 days. Thymuses of control animals were all normal. The development of tumors of the thymus in magnesium-deficient rats is discussed in connection with the changes in tissue histamine.

En quantités inférieures à 10 picogrammes, l'angiotensine inhibe la transmission synaptique du ganglion cervical supérieur du chat, et cet effet est antagonise par la dihydroergotamine. En quantités supérieures à 10 picogrammes, l'angiotensine facilite la transmission synaptique, et de plus, stimule directement les cellules ganglionnaires.

The effects of curarizing drugs, anticholinesterases, and musculotropic substances were studied on the phrenic nerve – diaphragm preparation of the hereditarily dystrophic mouse and of the rat treated with N,N-dimethyl-p-phenylenediamine (PPD), a cytotoxic substance producing dystrophic-like lesions. Both species showed an increased resistance to the neuromuscular blocking activity of d-tubocurarine. Gallamine was also less potent in the dystrophic mouse than in its normal littermate. Both species showed an increased sensitivity to the initial stimulant effect of succinylcholine; on the other hand, the depressant effect of succinylcholine was less intense in PPD-treated rats but unaltered in the dystrophic mouse. The response to neostigmine and physostigmine was decreased in the PPD-treated rat but enhanced in the dystrophic mouse. Musculotropic drugs (chlorpromazine, tetrodotoxin, xanthine derivatives, and veratrine) produced similar effects in normal and dystrophic mice. Two hypotheses are suggested to explain these changes in sensitivity in the dystrophic mouse diaphragm: (a) an increased production of an acetylcholine-like material, and (b) an increase in the number of acetylcholine-sensitive sites on the cell membrane. The changes in drug reactivity of the PPD-treated rat are considered to be due to a functional denervation caused by the cytotoxic properties of PPD.

The resistance of isolated rabbit atria to arrhythmic factors such as low potassium medium, acetylcholine, and electrical stimulation was determined before and after contact with reserpine and following administration of large doses of adrenaline. Animals pretreated with reserpine were found more sensitive to arrhythmic factors than untreated controls. Moreover, adrenaline was shown, in most cases, to abolish the induced arrhythmias or to lower the frequency of the atrial firing rate. As already suggested by Burn, this antiarrhythmic property of adrenaline at the atrial level is considered to be the result of an antagonism with acetylcholine, presumably through a lengthening of the duration of the action potential.

The influence of perfusion pressure on ventricular fibrillation was studied in the isolated rabbit heart. Sudden drops in perfusion pressure inhibit ventricular fibrillation in a few minutes, whereas a slow decrease of the pressure does not stop the fibrillation, but nevertheless reduces the ventricular firing rate. High perfusion pressures facilitate the induction of fibrillation; low pressures delay the production of arrhythmias and shorten their duration. It is postulated that this effect of pressure is primarily mechanical and not strictly dependent upon changes in the coronary flow or in the myocardial temperature.

This paper deals with the effects of five phenothiazine derivatives and quinidine against ventricular fibrillation induced in the isolated rabbit heart by small amounts of calcium chloride. Chlorpromazine and promethazine were more potent than quinidine in raising the calcium threshold for fibrillation. On the other hand, prochlorperazine and diethazine exerted biphasic effects: small concentrations increased the sensitivity of the heart to calcium chloride or induced fibrillation without calcium; higher concentrations had antifibrillatory effects and markedly depressed atrioventricular conduction. Thioproperazine was profibrillatory at all concentrations tested.