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EN
The formation of the oocyst wall was examined in Eimeria stiedai in the bile duct epithelium of the rabbit and was found to follow the general eimerian pattern. However from the beginning of the formation of the outer layer of the oocyst wall the parasite was surrounded by a rarely reported veil membrane. Cell damage of the bile ducts at the gamogony stage of parasite development is depicted.
EN
The adaptation and immunogenisity of Cryptosporidium parvum isolated from Siberian chipmunks (SC1 strain) in immunocompetent (ICR) mice were examined. The oocysts were received to the severe combined immunodeficiency (SCID) mice by repeated passage. The oocysts collected from the 18th SCID mice were inoculated to 5 ICR mice. The mice began to shed oocysts from 6 days after inoculation, the patency was 5 days, and the maximum oocysts per gram of feces (OPG) value was 104. The maximum of OPG value was gradually increased by successive passage, and finally that in the 22nd mice reached 106 (patency: 11 days). It is considered that these results indicate completion of their adaptation to ICR mice. To examine the immunogenicity of C. parvum to ICR mice, 8 groups of 5 mice each were inoculated with 1.3 × 106 oocysts of SC1 strain, which were collected after adaptation to SCID mice. All groups shed oocysts from 6th day, and their patency was from 8 to 12 days. On the 21st day after the primary infection, these mice were challenged with 1.3 × 106 oocysts. No oocysts shed from any groups, although 2 control groups shed oocysts from the 6th day, and their OPG values were more than 106. These results suggest that this strain has strong immunogenicity against ICR mice. Therefore, the immunological healthy mice were considered a useful experimental model to investigate immunological and drug treatments in the strain of C. parvum.
EN
This study demonstrated the presence of Cryptosporidium hominis in pigeons for the first time. Previously, C. hominis had been cited only in another bird species, Branta canadiensis. The present findings suggest that pigeons may act as mechanical vectors for this protozoan.
EN
Examination of 98 gold skink, Eumeces schneiderii Daudin, 1802 from Alexandria and Marsa-matroh Governorates, Egypt revealed oocysts of Choleoeimeria baltrocki (Daszak et Ball, 1991) n. comb. in the gall bladder and faeces. The prevalence of the infection was 40.8%. Sporulated oocysts were found in the faeces and the gall bladder contents. Sporulated oocysts were tetrasporocystic, cylindrical, reaching a mean of 38.7 (36–42) × 19.9 (17–25) μm with bilayered smooth and colourless wall. The dizoic sporocysts were subspherical and measuring 10.8 (9.5–13) × 9.3 (8–10.5) μm with a large globular sporocyst residuum. Sporocyst wall was bilayered joined by meridional suture. Sporozoites were crescent-shaped, blunt at one end and slightly tapered at the other. Endogenous stages (meronts, gamonts, gametes and young oocysts) were confined to the gall bladder epithelium and the infected cells were hypertrophied. Based on the morphological features of the exogenous stages and endogenous development of the present parasite, its generic affiliation was revised and placed into the genus Choleoeimeria.
EN
Isospora cagasebi sp. nov. (Apicomplexa, Eimeriidae) is reported from a bananaquit, Coereba flaveola from Brazil. Oocysts are sub-spherical, 24.9 × 24.5 (23.0–26.1 × 22.6–25.4), with a smooth, bilayered wall ∼1.4 and mean L:W ratio 1.0; micropyle, oocyst residuum and polar granule are absent. Sporocysts are elongate ovoidal, 18.7 × 11.5 (17.6–19.4 × 10.4–12.3), with both Stieda and substieda bodies and mean L:W ratio 1.6; sporocyst residuum present and sporozoites each with 2 refractiles bodies.
EN
Two new species of coccidia are described from passeriform (Icteridae) birds housed at the National Aquarium in Baltimore. Oocysts of Isospora icterus sp. n. from the troupial, Icterus icterus, are subspherical, 28.9 x 27.2 (27.2-32.0 x 25.0-30.0) µm, with a thick, bi-layered wall; shape index (length/width) is 1.06 (1.00-1.12). A micropyle is absent but a small oocyst residuum and large, irregularly shaped polar granule are present. Sporocysts are ellipsoidal, 17.8 x 12.8 (16.8-19.2 x 12.0-13.6) µm, with Stieda and substieda bodies; shape index 1.39 (1.33-1.52). A sporocyst residuum is present, consisting as numerous fine granules. Sporozoites possess a small anterior and larger posterior refractile bodies. Oocysts of Isospora graceannae sp. n. from the white-edged oriole, Icterus graceannae, are subspherical, 23.9 x 22.3 (20.0-26.4 x 18.6-25.0) µm, with a thick, bi-layered wall; shape index 1.07 (1.00-1.17). A micropyle is absent, but a small oocyst residuum and polar granule that often appears splintered are present. Sporocysts are ellipsoidal, 15.5 x 10.7 (14.2-16.2 x 10.0-11.4) µm, with Stieda and substieda bodies; shape index 1.44 (1.36-1.54). A sporocyst residuum is present, consisting as dozens of granules scattered among the sporozoites. Sporozoites with small anterior and larger posterior refractile bodies.
EN
The oocysts of Cryptosporidium parvum isolated from Microtus arvalis, Clethrionomys glareolus and calves were used in laboratory experiments carried out on 35 M. arvalis. Oocysts were detected in 43% of 14 voles infected with C. parvum derived from calves and in 54% of 13 voles infected with C. parvum isolates from C. glareolus. All voles inoculated with oocysts from M. arvalis (MA-voles) developed infection. There were observed differences in courses of infection between the three groups of voles with MA-voles demonstrating the most typical curve with an acute phase of infection in the first 4 weeks and a 2-week- long phase of self-curing. The infections with 'heterologous' C. parvum isolates (C. glareolus and calf isolates) transformed into chronic infections with lower oocyst productions. A strong host age effect was observed on prevalence of C. parvum among voles of different ages. Eight-month-old voles did not become infected and in older animals the infections were milder. The successful cross-transmission of two C. parvum isolates to M. arvalis suggests that this species should be considered as reservoir host for this important parasite of humans and animals.
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