Developmental Stages of Trypanosomatid Flagellates: a New Terminology
TL;DR: In the course of their cyclical development, flagellates of the genera Leishmania and trypanosoma pass through stages comparable with those of the monogenetic Trypanosomatidae and so it has been customary to refer to them by names derived from those genera in which the corresponding stages are the most characteristic forms.
Abstract: KNOWLEDGE of the structure and life cycles of the medically important Haemoflagellates of man and lower animals has increased during this century, and it became necessary to define the developmental stages of the leishmanias and trypanosomes in their mammalian and insect hosts. In the course of their cyclical development, flagellates of the genera Leishmania and Trypanosoma pass through stages comparable with those of the monogenetic Trypanosomatidae and so it has been customary to refer to them by names derived from those genera in which the corresponding stages are the most characteristic forms.
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TL;DR: A historical introduction of drugs assayed against Chagas disease beginning in 1912 with the works of Mayer and Rocha Lima up to the experimental use of nitrofurazone, and a survey about new classes of synthetic and natural compounds studied after 1992/1993.
Abstract: In this "Critical Review" we made a historical introduction of drugs assayed against Chagas disease beginning in 1912 with the works of Mayer and Rocha Lima up to the experimental use of nitrofurazone. In the beginning of the 70s, nifurtimox and benznidazole were introduced for clinical treatment, but results showed a great variability and there is still a controversy about their use for chronic cases. After the introduction of these nitroheterocycles only a few compounds were assayed in chagasic patients. The great advances in vector control in the South Cone countries, and the demonstration of parasite in chronic patients indicated the urgency to discuss the etiologic treatment during this phase, reinforcing the need to find drugs with more efficacy and less toxicity. We also review potential targets in the parasite and present a survey about new classes of synthetic and natural compounds studied after 1992/1993, with which we intend to give to the reader a general view about experimental studies in the area of the chemotherapy of Chagas disease, complementing the previous papers of Brener (1979) and De Castro (1993).
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TL;DR: Recent research on these developmental steps of T. cruzi in the vector are outlined, and the effects of different compounds acting against the parasite in the vectors are outlined.
277 citations
TL;DR: This chapter reviews some aspects of the cell biology of Trypanosoma cruzi, giving emphasis to those aspects related to the ultrastructure of pathogenic protozoa.
Abstract: Publisher Summary Among the protozoa of the Trypanosomatidae family, a large number of species represent agents of diseases, such as Chagas' disease. This chapter reviews some aspects of the cell biology of Trypanosoma cruzi, giving emphasis to those aspects related to the ultrastructure of pathogenic protozoa. Protozoa of the Trypanosomatidae family show, during their, life cycle, several forms which can be easily identified by light microscopy in Giemsa-stained preparations. The chapter also explains the life cycle of T. cruzi. In the life cycle of T. cruzi, there are forms which are able to divide. There is one form, considered to be highly differentiated and responsible for the infectivity of these protozoa, which does not divide. It is highlighted that the trypomastigote form can transform into a rounded form which possesses a free flagellum. This form, which appears in the stomach, is able to transform into either short epimastigotes that start a process of multiplication in the intestinum or into long epimastigotes which move to the more posterior region of the digestive tract of the bug. Cell surface is also emphasized in the chapter.
274 citations
TL;DR: This chapter is concerned with the immunological concepts in leprosy leading to a discussion of the analogous states now recognized in other infectious diseases, in which the clinical features of the disease depend on the cell-mediated immunity response of the host toward the parasite.
Abstract: Publisher Summary This chapter is concerned with the immunological concepts in leprosy leading to a discussion of the analogous states now recognized in other infectious diseases. The typical nodular form of leprosy, associated with massive infiltration of the tissues with histiocytcs packed with colonies of mycobacteria and an apparent inability of the body to eliminate the organism is one of the two main types of the disease. The other, the anesthetic or maculoanesthetic form, is associated with the peripheral nerve damage with or without cutaneous lesions. Here, the microorganisms may be scanty or difficult to demonstrate, and the skin lesions may come to resemble those in lupus vulgaris. Tuberculoid has, therefore, been used as a generic term to describe the second form of the disease; the nodular form of leprosy is now referred to a lepronzatous. Leishmaniasis is a spectral disease similar to leprosy, in which the clinical features of the disease depend on the cell-mediated immunity (CMI) response of the host toward the parasite. When this response is deficient, diffuse cutaneous leishmaniasis (DCL) results. The possible reasons for such deficiency in CMI is also discussed with their nature and specificity of the defect.
260 citations
TL;DR: The contribution of the flagellar pocket to protein trafficking, immune evasion and other processes are discussed.
Abstract: Trypanosomes are important disease agents and excellent models for the study of evolutionary cell biology. The trypanosome flagellar pocket is a small invagination of the plasma membrane where the flagellum exits the cytoplasm and participates in many cellular processes. It is the only site of exocytosis and endocytosis and part of a multiorganelle complex that is involved in cell polarity and cell division. Several flagellar pocket-associated proteins have been identified and found to contribute to trafficking and virulence. In this Review we discuss the contribution of the flagellar pocket to protein trafficking, immune evasion and other processes.
252 citations
Cites background from "Developmental Stages of Trypanosoma..."
...The cellular morphology differs between distinct forms of trypanosomes with regard to the relative positions of the nucleus, kinetoplast (and therefore basal body) and flagellum exit point along the anterior–posterior axi...
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TL;DR: A check-list of North American Birds and Studies on blood protozoa obtained from Mexican wild birds, 1931-40.
Abstract: BRUMPT, E. 1927 Precis de Parasitologie. 4th Ed., Masson & Cie, Paris. Check-list of North American Birds. 1931 4th Ed. American Ornith. Union. HEWITT, R. 1940 Studies on blood protozoa obtained from Mexican wild birds. J. Parasitol. 26: 287-295. WENYON, C. M. 1926 Protozoology. Wm. Wood & Co., New York. WOOD, F. D. AND WOOD, S. F. 1937 Occurrence of haematozoa in some California birds and mammals. J. Parasitol. 23: 197-202.
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TL;DR: The morphology of 4 genera of the family Trypanosomatidae has been studied with particular reference to the contractile vacuole, reservoir, flagellum, undulating membrane, kinetoplast, and nucleus.
Abstract: SYNOPSIS. The morphology of 4 genera of the family Trypanosomatidae has been studied with particular reference to the contractile vacuole, reservoir, flagellum, undulating membrane, kinetoplast, and nucleus. Both the contractile vacuole and reservoir have been found in all species examined. Four morphological types of culture forms are described with special reference to these structures: (1), the Crithidia fasciculata type which is short and membraneless with a rounded posterior end, truncate anterior end and a well developed reservoir; (2) the Herpetomonas muscarum type with no undulating membrane, a truncate posterior end, a rounded anterior end and a reservoir which varies in length from about 1/6 of the length of the body to the full length of the body; (3) the Leishmania type with no undulating membrane, a pointed posterior end, an asymmetrical anterior end and a short reservoir which remains constant in size; and (4), the short-membraned type exemplified by Trypanosoma cruzi, with a pointed posterior end, a short reservoir near the middle of the body and the flagellum attached to the body along a portion of its length. This last form is derived from the blood stream morphology as exemplified by Trypanosoma lewisi in the rat by a shifting of the kinetoplast, flagellum, reservoir and contractile vacuole along the surface of the body from a position posterior to a position anterior to the nucleus.
37 citations