1000 resultados para Emblemasoma mexicana n. sp.


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A new species of South American lymnaeid snail, Lymnaea rupestris, is described. So far it has been found only in its type-locality, Nova TeuTõnia, a village in the municipality of Seara (27° 07' S, 52° 17' W), state of Santa Catarina, Brazil. It is distinguishable, by characteristics of the shell and internal organs, from the other two lymnaeid species known to occur in the area, Lymnaea columella and L. viatrix. Its shell has 4 markedly shouldered whorls, deep suture, ovoid or rounded aperture occupying about half the length of the shell, and reaches about 6 mm in length in adults; in columella and viatrix the shell has 4-5 rounded whorls, shallow suture, and reaches over 10 mm in adults; the aperture is ovoid, occupying about half the length of the shell in viatrix, about two thirds in columella. Anatomically it is readily separated from L. columella by the shape of the ureter, straight in rupestris, with a double flexure in columella. Comparison with L. viatrix shows the following main differences: distalmost portion of the oviduct with a low, caplike lateral swelling in rupestris, with a well-developed pouch in viatrix; uterus bent abruptly caudalward in rupestris, only slightly curved rightward in viatrix; basal half of the spermathecal duct hidden by the prostate in rupestris, wholly visible or nearly so in viatrix; spermiduct sinuous and uniformly wide in rupestris, straight and gradually narrowing in viatrix; prostate more than half as long and nearly as wide as the nidamental gland, and with a slit-like lumen in cross-section in rupestris, less than half as long as and much narrower than the nidamental gland, and with an inward fold in cross-section in viatrix; penial sheath about as long and as wide as the prepuce in rupesris, shorter and narrower than the prepuce in viatrix. An important ecological characteristic of L. rupestris is its habitat on wet rocks most often outside bodies of water, although in close proximity to them. Specimens were deposited in the following malacological collections: Instituto OswaldoCruz, Rio de Janeiro; Academy of Natural Sciences, Philadelphia; Museum of Zoology, University of Michigan; and British Museum (Natural History).

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Studies were undertaken to determine the influence of several host-related parameters on the course of Leishmania mexicana mexicana infection in inbred C57B1/10 (C57) and outbred albino (OA) mice. An important influence of the following variables was demonstrated: Host strain: lesions in C57s were significantly less variable in size and outcome than those of OAs under the conditions studied and even when persistent developed at a slower rate. Host age: Subcutanous injection of 2 x 10 [raised to the power of 4] to 2 x 10 [raised to the power of 6] amastigotes into the dorsum of the rear paw produced significantly larger lesions which healed more slowly in 2 mo. old C57s than in 4 mo. old mice. Reduced healing ability was observed in older (8 mo. old) female C57s, and low mortality occurred after 15 months of age in infected mice of both sexes. Lesion site: Following amastigote infection, lesions in paws of most C57s regress within 15 - 25 wks. In contrast, perinasal legions produced with the same number of parasites tend to persist for the life of the animal as slowly spreading irregular nodules. In animals infected in both locations, each lesion site behaves similarly to that in singly infected animals of the same age, i.e. regression in the two sites is independent. Our results indicate that while host strain may strongly influence infection outcoem, such variables as lesion site and host age play important roles and may explain, in part, reported inter- and intraexperimental variability in responses of murine hosts to a given leishmanial parasite.

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Unstimulated adherent mouse peritoneal cells were cultured in vitro and infected with equal numbers of a single strain of Leishmania m. mexicana amastigotes (AM), virulent promastigotes (VP), avirulent promastigotes (AVP) and fixed promastigotes (FP). Duplicate May-Grünwald-Giemsa stained coverslips were examined at time intervals up to 13 days. By 3 hr post infection, the number of macrophages containing parasites varied between 60.5% (VP) and 84% (AM) for macrophages exposed to living parasites, compared to 6.5% for macrophages exposed for FP. However, variable numbers of parasites showed degenerative changes by 3 hr, and the number of macrophages containing morphologically intact parasites varied significantly between cells infected with AM (84%) and those infected with VP (42%) or AVP(40%). The mean number on intacte parasites/macrophage also differed significantly between AM-infected cells and living or fixed promastigotes-infected cells. Quantitation of intact and degenerated parasites indicated parasite multiplication, as well as destruction, in VP-infected cells and parasite survival and multiplication in AM-infecte monolayers; in contrast no evidence of parasite multiplication was seen in AVP-infected cells. Changes in the mono layer itself (cell loss and macrophage vacuolization) were also evaluated. These results suggest that crucial events determining the outcome of infection occur in the host-parasite relationship during the fist 24 hours of infection. These events are apparently influenced not only by parasite or host strain but by environmentally induced variation within a given strain.

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É descrita uma nova espécie de Trypanorhyncha, Progrillotia dollfusi sp. n., de pescadas do gênero Cynoscion (Sciaenidae). Os peixes mostraram-se intensamente parasitados. As características principais desta espécie são os dois botrídios, a armadura tipo pecilacanto dos ganchos e a armadura basal da probóscide.

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O autor descreve uma nova espécie de poliplacóforo (Acanthochitona terezae) para o litoral brasileiro, apresenta dados sobre sua morfologia e discute aspectos biogeográficos.

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Se describe el macho de Lutzomyia amilcari sp.n. capturado en el Parque Nacional de Yacambú, Distrito Andrés Eloy Blanco, Estado Lara, Venezuela. La especie puede ser identificada por la forma característica del parámetro. Pertenece al grupo Verrucarum, serie Verrucarum de Theodor (1965).

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Ascarophis brasiliensis recovered from the stomach of Trachinotus carolinus (L. 1766), is proposed as a new species and Procamallanus (Spirocamallanus) pereirai Annereaux, 1946 is redescribed from a new host: Paralonchurus brasiliensis (Steind., 1875). A. brasiliensis is more closely related to A. crassicolis Dollfus & Campana-Rouget, 1956, from which it differs mainly by the absence of cervical cuticular expansion and size of the eggs. The new species is also compared to A. cooperi johnston & Mawson, 1945 and A. girellae (Yamaguti, 1935) Campana-rouget, 1955. The validity of the proposed species is discussed.

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Do meato auditivo de bovinos que padeciam de otite, o autor isolou e descreveu duas novas espécies de Nematoda-Rhabditidae: Rhabditis (Rhabditis) freitasi sp.n. do município de Formosa, Estado de Goiás, e Rhabditis (Rhabditis) costai sp.n. do município de Sertãozinho no Estado de São Paulo.

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Angiostrongylus (Parastrongylus) costaricensis, nematódeo encontrado em artérias mesentéricas do rato silvestre Proechimys sp., na Venezuela, é redescrito e colocado no subgênero Parastorngylus.

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Adults and nymphs of Cavernicola lenti, new species, from Amazonas state, Brazil, are described and illustrated. Observations on the biology of the new species are presented. Preliminaty findings indicate that C. lenti is a probable vector of bat trypanosomes.

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In the present study we measured the blastogenic response of lymph node cells from BALB/c mice infected with Leishmania mexicana throughout the course of infection. Results showed that infected mice displayed normal blastogenic responses in the lymph nodes until twenty weeks of infection. Thereafter, there was a gradual suppression. Comparison of the immunoresponsiveness in the spleen and lymph nodes, revealed normal responses in the lymph nodes several weeks after suppression in the spleen had occurred. Suppression of blastogenic responses in the lymph nodes was related to an adherent macrophage-like cell which actively suppressed normal proliferative responses to mitogens.

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During recent studies of the parasites of birds from the Amazonian Regio, the following nematodes were recovered: Hoazinstrongylus amazonensis n.gen.n.sp. from Opisthocomus hoazin (Muller, 1776); Ascaridia columbae (Gmel., 1790) Travassos, 1913, from Leptotila r. rufaxilla (Richard & Bernard, 1712) representing a new host record; Inglisakis ibanezi Freitas, Vicente & Santos, 1969, Cyrnea (C.) semilunaris (Molin, 1860) Seurat, 1914 and Thelazia digitata Travassos, 1918. A compelte description is restrained to the new genus and new species here proposed. The other known and well described species are listed and accounted.

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Twelve species of parasitic helminths, seven trematodes, four nematodes and one acanthocephalan are reported from various hosts. Creptotrema lynchi, a parasite from Bufo marinus in Colombia, is described for the first time in fish and from Brazil, parasitizing two different species. A list of the host species, measurements and figures of most parasites are included with particular reference to the tegument of Bellumcorpus major recovered from a new host. The genus Zonocotyloides Padilha, 1978 is considered a synonym of Zonocotyle and the new combination: Zonocotyle haroltravassosi is proposed to the species Zonocotyloides haroltravassosi Padilha, 1978. The nematodes Cucullanus pinnai and Procamallanus (Spirocamallanus) inopinatus and the trematode Pararhipidocotyle jeffersoni are reported in new hosts. The description of the acanthocephalan Neoechinorhynchus curemais (new locality record) is supplemented. Other parasites recovered include the nematodes Travnema travnema (new locality record), Rondonia rondoni and the digenetic trematodes Cladocystis intestinalis, Pseudosellacotyla lutzi (new locality record), Teratotrema sp. and Zonocotyle bicaecata.

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As a preparatory stage for a study aiming at identifying the species and subspecies of local Leishmania in naturally infected sandflies through immunoradiometric assay with monoclonal antibodies, we tried to obtain experimental infections of phlebotomines with well characterized stocks of parasites, in order to test the effectiveness of the method.