The development of Plasmodium gallinaceum from sporozoite to erythrocytic trophozoite / Clay G. Huff and Frederick Coulston.

  • Huff, Clay G., 1900-
Date:
1944
Catalogue details

Licence: Public Domain Mark

Credit: The development of Plasmodium gallinaceum from sporozoite to erythrocytic trophozoite / Clay G. Huff and Frederick Coulston. Source: Wellcome Collection.

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    tinguishable morphologically from cryp- tozoites about 24 hours old, except that some of them are more advanced in de- velopment (figs. 36-38). The same differences in staining from the dry smear and the wet fixation smear or section technics as mentioned above for the sporozoites and cryptozoites are observed in these forms (Cf. figs. 50 and 51; also 54 and 55). The parasites in the inoculation site are much more numer- ous in this generation than in the cryp- tozoic one. ; The development from 60 hours to 72 hours is very comparable to that which occurs between 24 and 36 hours (figs. 39-42, 52-53, 56, 58-61). Multiple in- fections of cells of the lymphoid-macro- phage system are very common (fig. 53). In a few birds we have seen also in the local injection site at 70 hours num- erous examples of a curious cannibalism amongst the infected polyblasts and macrophages. This may be complex as shown in figure 59, or simple. A large macrophage is here shown to contain 1 schizont, 1 macrophage with ingested schizont and 2 macrophages, one inside the other, and each containing a schiz- ont within itself. The second schizog- ony begins at about 70 hours (fig. 58). Morphologically the large schizonts and segmenters appear to be identical with those of the first generation. Although the preponderance of merozoites from the second generation again enter mac- rophages and endothelial cells, we have evidence, as shown below, that they may enter erythrocytes as early as 75 hours after the inoculation of sporo- zoites. A complete analysis of the events taking place henceforth in our material becomes very difficult because the syn- chronism of growth diminishes until practically all stages of growth are en- countered at a particular time and the genealogy of the various cryptozoic, metacryptozoic, and erythrocytic stages cannot be clearly traced. However, between the 3rd and 5th days of the infection the exoerythrocytic stages increase greatly in numbers and become more widely spread in the body, for at the end of this time practically all organs are invaded. As early as the 5th day 2 different types of segmenters are present in the local injection sites (figs. 64). Some of them are similar to crypto- zoic segmenters in possessing smaller numbers of merozoites (100-200) and larger individual merozoites than do the other type (fig. 64a). Others of them resemble the exoerythrocytic segment- ers which prevail in infections produced by inoculations of infected blood and also later in infections produced from sporozoites. They have very large num- bers (about 500 to 1,000) of smaller, more tightly packed merozoites which also appear to stain more deeply than the cryptozoic type (fig. 64B). In contrast to the scarcity of crypto- zoites in the organs of animals inocu- lated intravenously with large doses of sporozoites, metacryptozoites were found to be abundant in spleen, cardiac muscle, kidney, brain, liver, lamina pro- pria, bone marrow, thymus, etc., at the same time intervals as they were found in the skin. In these sites they were found especially in the endothelial cells and occasionally in cells of the lymph- oid-macrophage system. Since the subsequent events in the infection fall outside the scope of this ysis here. We shall, however, give a few facts about the early parts of the erythrocytic infections which bear upon the problem. The beginning of the parasitemia. The earliest infected erythrocyte to be encountered was found in a.small chick 75 hours after the ground salivary
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