[The bio-psycho-social tridimensional constructivism of Socolas' School in the perspective of contemporary psychiatry (author's transl)]. / Le constructivisme tridimensionnel bio-psycho-social de l'école de Socola dans la perspective de la psychiatrie contemporaine.

The authors present the characteristics of the bio-psycho-social concept, developed by the School of Iasi, with pertinence and consequence on and after 1960. This one affirms its originality through its constructivistic psychiatric theory based on the tridimensional concept. The authors review several concepts of "constructivism" and analyze its implications in psychology, psychoanalysis, sociology, ethnology etc. This critical review shows once more the originality and specificity of the approach of the School of Socola. The bio-psycho-social concept is conceived as a dynamic and unitary concept and is applyed through a close link between psychiatric services and society and through an intense interdisciplinary activity aimed at the knowledge of the whole man.

A strain of Plasmodium vivax characterized by prolonged incubation: the effect of numbers of sporozoites on the length of the prepatent period.

The North Korean strain of Plasmodium vivax was characterized by its extraordinarily prolonged incubation period in certain circumstances. It was clearly demonstrated by quantitative observations that the phenomenon may be elicited by the inoculation of small numbers of sporozoites. After the intradermal inoculation of 10 or 100 sporozoites, the incubation period was delayed for periods varying between 262 and 628 days; after u,000 sporozoites, with one exception, the same delay occurred; after 100,000 sporozoites, the incubation period was always of normal duration (13--16 days). Two laboratory-acquired infections in workers who had taken a prophylactic drug showed incubation periods of 315 and 329 days, respectively. Various theories for the phenomenon of prolonged prepatent periods are examined, and the most satisfactory one is based on the presumed existence of two populations of sporozoites in P. vivax. In temperate strains, sporozoites requiring long prepatent periods (LPP) for development are present in great excess over a much smaller proportion of sporozoites characterized by short prepatent periods (SPP); thus small doses will elicit the phenomenon, though doses of over 1,000 sporozoites will mask the effect as the few SPP sporozoites will produce an infection with a normal (i.e. short) prepatent period. In tropical strains, the relative proportions are different, perhaps in equal numbers, and even in small doses some SPP sporozoites will be present and normal prepatent periods should ensure whatever the dosage."

Prepatent periods of a tropical strain of Plasmodium vivax after inoculations of tenfold dilutions of sporozoites.

Eleven patients requiring malaria therapy were inoculated intradermally with graded doses of sporozoites of the Chesson strain of Plasmodium vivax. Estimated doses of 10 sporozoites were given to four patients, of 100 to three patients, of 1,000 to two patients, and of 10,000 to two patients. Parasitaemia was detected in all patients 12 to 17 days after inoculation; fever began on the 14th to 19th days. The results of the trials are compared with earlier work on a temperate strain of P. vivax in which patients given small doses of sporozoites exhibited long prepatent periods of 257 days or more. It is concluded that the differences in the two strains can be explained by the assumption that, in varying proportions, all strains of P. vivax produce two types of sporozoites, one eliciting short prepatent periods (Type I), and the other lying dormant or developing slowly to give rise to long prepatent periods (Type II). The latter type greatly predominates in temperate strains, but not in tropical strains; at high dilutions, therefore, pure suspensions of Type II sporozoites of temperate strains can be prepared. It is thought that relapses of P. vivax are in reality a dalyed parasitaemia arising from Type II sporozoites.