Biomedical subjects
Publications and source records attributed to I Landau.
Trypanosoma (Megatrypanum) lizae n. sp.: trypanosome with giant forms reaching a length of 1400 micrometers from the Microchiroptera Hipposideros cyclops in Gabon. Because of the peculiar morphology of giant forms and the characteristics of small individuals it is placed in a new species within the subgenus Megatrypanum.
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Description of the male fo Filaria cephalophi Chabaud and Rousselot, 1956 which was unknown. The species is a parasite of Cephalophus dorsalis in Congo and Gabon. Description of Dipetalonema (Loxodontofilaria) faini n. sp., parasite of Cephalophus nigrifrons. The species is closely related to the two Filariae known from Cattle in Ruanda.
Description of the gametocytes and the schizonts of H. muuli and of the gametocytes of Hepatocystis sp. parasites of Menetes berdmorei in Thailand. The schizonts of H. muuli are intrahepatocytic and provoke an hypertrophy of the host cell and its nucleus which remain visible during the entire development of the tissue stage. Old schizonts are very lobulated and the colloid is abundant and irregularly distributed. Histiomacrophagic reaction of the surrounding tissue remains moderate before the maturity of the parasite.
Hepatocystis carpenteri n. sp. parasite of Hypsignathus monstrosus in Gabon is different from Hepatocystis epomophori and Hepatocystis brosseti, parasitic in other African Megachiroptera. H. carpenteri has bigger intrahepatic schizonts and a wall with a spongy appearance which has not been seen in other Hepatocystis.
The duikers from Makokou (Gabon) are parasitized by many species of Onchocerca but the adults are very often occult and can only be discovered by a systematical search. Three new species are described: O. sonini n.sp. in the feet-tendons, and O. lerouxi n.sp. in the muscular aponevrosis of the trunk of C. nigrifrons; O. beaveri n.sp. in the ligaments of the atlas-occipital articulation of C. monticola. Although their external appearance differs, these three species belong to a single group, which, from an evolutionary point of view, is intermediate between the more primitive Onchocerca of Equiids and those more evolved from other animals.
The authors report biomorphological changes of Plasmodium inui gametocytes during the natural infection of spleenless Macaca fascicularis. The infection was controlled up to the 42th day by smears produced by pricks into their ears (P.O.) and on blood taken at the same time by A. stephensi (P.M.). The first oocystes appeared on the 8th day after the infection in mosquitoes fed on the monkey parasitised in the eight day after splenectomy, as gametocytaemia was not detectable yet in the P.O. smears. The infectivity of gametocytes is highest on the 13rd day for a 152/10(4) parasitaemia. The first sporozoites appeared on the 18th day at 25 degrees C after the infecting meal. The sporozoites were infecting for a second monkey. Four morphological types (O, I, II and III) gametocytes were identified. They corresponded to the same types previously described in rodent Plasmodium. The maximum of infectivity coincided with a sudden increase in mosquitoe macrogametocytaemia; on the other hand the infectivity was very weak during the following peek of macrogametocytaemia which corresponded however to the maximum of parasitaemia (1 318/10(4) 18 days after splenectomy). When infectivity was important, there was a greater number of type O and I gametocytes in P.M. than in P.O. Eventually, the behaviour of P. inui gametocytes is, for the mainly, almost the same as that of rodent Plasmodium. However, it is to be noted that the identification of the 4 morphological types in P. inui is easier in macrogametocytes than in microgametocytes. The reverse had been observed in rodent Plasmodium.
The Haemosporidia of Mammals are classified in 3 groups according to the morphology of the gametocytes: 1) group "vivax" with Hepatocystis and several species of Plasmodium; 2) group "malariae" with Nycteria and a second group of Plasmodium; 3) group "falciparum" with only Plasmodium. In each group there is a correlation between the morphology of the gametocytes and that of the exo-erythrocytic schizonts. Through discussing the host-range and comparing the life cycles of Haemosporidia in Birds, Reptiles and Mammals, we suggest a hypothesis of the polyphyletism of Plasmodium of Mammals.
Malaysian Sciuridae are often parasitised by 2 species of Hepatocystis which were described as a single species Hepatocystis vassali malayensis by Field and Edeson, (1950). One of them corresponds to the majority of forms seen by Field and Edeson; it is redescribed herein and raised to specific status: H. v. malayensis becomes H. malayensis Field and Edeson, 1950. By the morphological characteristics of its gametocytes and schizonts, H. malayensis is related to H. kochi. The evolution of tissue schizonts studied at liver biopsies and autopsies of squirrels captured shortly before examination is of a peculiar type: an immunological tissue reaction appears with the hyperinfestation of the Rodents and controls the growth of the schizonts.
Hepatocystis brayi n. sp. is described and separated from the second species parasitising Malaysian Sciuridae, H. malayensis Field and Edeson, 1950. H. brayi is characterized by: 1) the evolution of its tissue schizonts which are intracellular throughout all their development; the cytoplasm and the nucleus of the host cell are highly hypertrophied; 2) the scarcity of the colloid. The schizogony persists for several months in the liver of infected animals and the gametocytaemia apparently undergoes seasonal relapses. H. brayi is a parasite of hosts occurring in the middle and under canopy, H. malayensis the middle and top canopy.
The development of H. brayi was followed mainly in C. variipenis up to the stage of mature oocysts. Unlike H. kochi, the oocysts of H. brayi develop at the same site as those of Plasmodium between the epithelium and the basal membrane of the stomach.
A new Haemoproteid of Malaysian Microchiroptera (Hepatochstis rodhaini n. sp.) is described; it is classified in the genus Hepatocystis because of the morphology of its gametocytes and tissue schizonts.