Trypanosomes and trypanosomiases / by A. Laveran and F. Mesnil ; tr. and much enl. by David Nabarro.
- Charles Louis Alphonse Laveran
- Date:
- 1907
Licence: Public Domain Mark
Credit: Trypanosomes and trypanosomiases / by A. Laveran and F. Mesnil ; tr. and much enl. by David Nabarro. Source: Wellcome Collection.
Provider: This material has been provided by the Francis A. Countway Library of Medicine, through the Medical Heritage Library. The original may be consulted at the Francis A. Countway Library of Medicine, Harvard Medical School.
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![uncoagulable (as by the addition of sodium citrate solution). The trypanosomes are found in the middle or leucocytic layer.1 In the case of dourine, we shall see that it is the blood-stained oedema fluid which should be examined. In sleeping sickness the blood and the cerebro-spinal fluid obtained by lumbar puncture should be examined for trypanosomes after centrifuging. When it is desired to watch the parasites for a considerable time, it is necessary to make hanging-drop preparations ringed with vaseline or paraffin. Such preparations are very useful, especially for studying the phenomena of agglutination. The blood is diluted with physiological salt solution and then defibrinated, or with citrated salt solution to prevent coagulation, or with serum from another animal. Francis,2 for Trypanosoma lewisi, advises letting the blood coagulate : the trypanosomes pass out into the serum, where they can be studied apart from the red corpuscles. Generally at the end of an hour in an ordinary slide and coverslip preparation, or a little longer in the case of a hanging drop, the trypanosomes become less active, and one is then able to study their shape and the movements of their various parts more in detail. In order to reduce or arrest this movement of the trypanosomes, Plimmer and Bradford3 recommend adding a drop of a i per cent, solution of gelatine [or of a weak solution of cherry-gum] to the blood. Section 2.—Staining5 Methods. In the fresh state the general form of trypanosomes, their move- ments, and the action of physical and chemical agents upon them, can be studied. In order to obtain, however, a clear idea of their intimate structure, it is essential to study preparations stained by a special method—namely, a mixture of eosin and methylene blue in definite proportions. This mixture was first used by Romanowsky for staining hsematozoa (the malarial parasite). It was applied to the staining of trypanosomes in 1898 by Ziemann,4 who thus stained the nucleus and centrosome in the trypanosome of the frog. The following year Rabinowitsch and Kempner5 stained T. lewisi by this method; but the most beautiful results were obtained in 1900 by Wasielewski and Senn,6 also with T. lewisi. They used Nocht's modification of Romanowsky's method. The following method7 has given us excellent results: 1 We found this method useful in collecting together above the layer of red corpuscles the trypanosomes from a rat or dog with nagana when the parasites were more numerous than the red corpuscles. 2 Francis, Bull. No. II, Hyg. Laby., U.S. Pub. Health and Mar. Hosp. Serv. Washington, 1903. 3 Plimmer and Bradford, Centralbl. f. Bakter., I, v. 26, 1899, p. 440 ; [also Quart. Journ. Micr. Se., v. 45, 1901, p. 451.] 4 Ziemann, Centralbl. f. Bakter., I, v. 24, 1898. 6 Rabinowitsch and Kempner, Zeitschr.f. Hyg-, v. 30, 1899, p. 251. (i Wasielewski and Senn, Zeitschr.f. Hyg., v. 33, 1900, p. 444. 7 A. Laveran, Compt. Rend. Soc. Biol., June 9, 1900.](https://iiif.wellcomecollection.org/image/b21172286_0032.jp2/full/800%2C/0/default.jpg)
