摘要:

ABSTRACTThe sensitivity of the microtubular systems to cold and nocodazole treatments as well as the cellular distribution of microtubules containing acetylated a‐tubulin have been studied in Paramecium. Our results indicate that the microtubular systems ofParameciumshow marked differences in stability. Cold and nocodazole treatments produce the depolymerization of the major part of the cytoplasmic microtubular network while the cortical structures remain stable under treatment. This differential stability of the microtubular systems is associated with the acetylation of the a‐tubulin. The use of the antibody 6‐11B‐1, specific for acetylated α‐tubulin, shows that the microtubular systems containing acetylated a‐tubulin are the same as those that remain stable after depoly‐merizing treatments. Finally, the images obtained during the repolymerization by heating suggest that the cortical dikinetids are able to nucleate the microtubules of the cytop

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01056.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTA microspondium of the mosquitoAedes aegypti(L.), identified asNosema aedisKudo, 1930, was found to be a heterosporous species with 3 sporulation sequences. Usually, I sequence developed in a parental generation host individual that was infected per os as a larva and the other 2 developed concurrently in a filial host larva that was infected transovarially. Under some conditions there were deviations from the parental host‐filial host alternation. The 1st sporulation sequence was diplokaryotic (diploid in a particular sense) throughout; the other 2 arose from diplokaryotic meronts, developed concurrently and ended with haploid spores. Haplosis in 1 case was by means of dissociation of the diplokaryon. In the other case it was by meiosis. Conflicting reports about whether the members of the diplokaryon in the latter sequence separate and undergo meiosis individually or coalesce and undergo meiosis as I nucleus were resolved in favor of the latter idea. A new genus in family Amblyosporidae was created to contain this species. which then becameEdhazardia aedis(Kudo. 1930) n. g., n. com

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01057.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTEimeria ornatan. sp. is described from the feces of 6/16 (37.5%) ornate box turtles,Terrapene ornata ornata, in northcentral Texas. Endogenously sporulated oocysts are ellipsoid 17.9 × 15.7(16‐21 × 14‐18) μm, with a thin, single‐layered wall; shape index 1.14 (1.0‐1.3). A micropyle is absent but a polar granule was present in one third of the oocysts. An oocyst residuum was present, consisting of numerous small globules situated either in a distinct mass or scattered within the oocyst. The sporocysts are elongate, 11.1 × 5.4 (9‐13 × 5‐6) μm, with an indistinct Stieda body at 1 pole. A sporocyst residuum is present, consisting either as a compact mass or as scattered granules. The sporozoites are elongate, 9.5 × 2.0 (8‐12 × 2) μm, in situ, with spherical anterior and posterior refractile bodies. The new species is distinguished from the similarEimeria carriErnst&Forrester, 1973, from eastern box turtles,T. Carolina, by slight differences in oocyst morphology and

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01058.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTEpithelial‐type (PK‐15) and fibroblast‐type (MDBK) mammalian cell cultures were inoculated with purifiedEimeria vermiformissporozoites. Matched samples from 0 to 93 h after inoculation (HAI) were processed for electron microscopy; half of the sample preparations were extracted with non‐ionic detergent prior to fixation. Specimens were examined by both transmission and scanning electron microscopy. Numerous sporozoites were attached to the cultured cells from 2 to 93 HAI, usually near the cell periphery. Some host cell microvilli extended up and appeared attached to the sporozoites. Sporozoites fixed during the penetration process were markedly constricted at the site of entry; however, no noticeable changes occurred in the host cell membrane or surface microvilli during sporozoite invasion or in sporozoite‐infected cells. In cells extracted with 1% Triton X‐100, the host cytoskeleton was progressively reorganized about the parasites but changes were limited to the immediate area of the sporozoite. Around resident sporozoites, the cytoskeleton became less dense but also more ordered, which contrasted with adjacent cell areas. Cytoskeletal elements passed both over and under the parasites. The appearance of the cytoskeleton suggested that the host cell formed a loose, basket‐like net of cytoskeletal elements about

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01059.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTThe effects Ca2+ channel blockers, verapamil, nicardipine and diltiazem, and of potent calmodulin (CaM) inhibitors, trifluoperazine (TFP), calmidazolium, W‐7 and W‐5, on Plasmodium falciparum in culture were examined. Among Ca2+ blockers, nicardipine was the most potent with the 50% inhibitory concentration (IC50) of 4.3 μM at 72 h after culture. Parasites were more sensitive to calmidazolium and W‐7 with IC50 of 3.4 and 4.5 μM, respectively, than to TFP and W‐5. All Ca2+ blockers and CaM inhibitors suppressed parasite development at later stages. Nicardipine, ditiazem, calmidazolium and W‐5 also retarded parasite development at earlier stages and/or subsequent growth following pretreatment. Verapamil, nicardipine, TFP and calmidazolium reduced erythocyte invasion by merozoites. Fluroscence microscopy with the cationic flurescent dye rhodamine 123 revealed that nicardipine. TFP and calmidazolium depolarized both the plasma membrane and mitochondrial membrane potentials of the parasite. It is therefore considered that although al Ca2+ and CaM antagonists tested here influence parasite development at later stages, they are multifunctional, having effects not directly associated with Ca2+ chan

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01060.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTFlow cytometry was employed as a tool to analyze and characterize batches of oocysts from laboratory and field isolates ofEimeriaspp. from chickens and to propagate sub‐populations of batches of oocysts. Oocyst batches were cleaned of debris by a combination of salt flotation, washing and treatment with dilute sodium hypochlorite (1.5% aqueous). Oocyst size and shape were registered by forward‐angle light scatter with the argon laser excitation set at 488 nm at 300 mW. Sub‐populations of oocysts were collected by map gating and used for microscopy or for propagation. The profile of particle size was characteristic for each species. Propagation of sub‐populations of oocysts of specified sizes resulted in cultures of coccidia that were pure species or nearly pure species. The small size ofE. millscaused difficulty in separation from the remaining fine debris. This technique was useful for studying the variation in oocyst size within populations and characterization of field isolates of mixed species. Propagation of pure species from mixed isolates by bit‐map gating had the same limitations as micromanipulation because of the overlapping size ofEimeriaspp. Chancaerization is further limited by the lack of suitable size/shape standards for flow cytometry‐Key words. Cell sorter.Eimeriaspp., oocyst shape,

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01061.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTNormal human milk (NHM) has antiprotozoal activity unrelated to immunological components; this activity extends to sporozoites ofEimeria tenella. This activity may be due to free fatty acids (FFA) enzymatically hydrolyzed from tnacyl glycerols by a bile salt‐stimulated lipase (BSSL) found in NHM. Sporozoites were therefore incubated in the presence of several saturated and unsaturated FFA. Anticoccidial activity was observed for many unsaturated fatty acids and for some saturated fatty acids. In addition, sporozoites were added to solutions of triglycerides (trilinolein, triolein and trilinolenin) preincubated with BSSL and sodium cholate. which resulted in killing of the parasites. Triglycerides alone showed no anticoccidial activity. These results were duplicated with first generation merozoites. Intracellular stages ofE. tenellawere affected by FFA only at concentrations that inhibited host cell

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01062.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACT Epimastigotes ofTrypanosoma cruzi, Peru strain, incubated in Contreras’artificial triatomine urine transformed into metacyclic trypomastigotes within 48 h at 28° C when 10 mM L‐proline or L‐glutamate was added to the medium. Smaller numbers of metacyclic stages were induced in the presence of glucose or L‐alanine. The L‐leucine and L‐isoleucine, 2 amino acids known to inhibit proline catabolism, inhibited proiine‐induced metacyclogenesis. Cells gassed with 5% CO2showed significantly faster rates and higher levels of transformation than those not gassed, therefore indicating the additional importance of CO2for

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01063.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTThe histopathological changes that occur in the uninfected liver lobes of gerbils with a localized amebic liver abscess (left lobe) were studied from 5 to 60 days after inoculation. Early parenchymal changes (10 days) in the right and median liver lobes showed a lymphocytic infiltrate and bile duct proliferation in the portal areas. Maximum alternations occurred at 20 to 30 days after inoculation and were characterized by a dense portal infiltrate, hepatocyte degeneration, granulocytic infiltrate and marked glycogen depletion. In drug‐treated infections with metronidazole, the diffuse liver inflammation was terminated. The results of this study suggest that the diffuse liver injury was directly or indirectly induced by the presence of a proliferating amebic liver abscess and that the pathology caused by amebic liver abscess is more extensive than previously though

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01064.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY

摘要:

ABSTRACTSera from fish that survive infections with the ciliated protozoon,Ichthyophthirius multifiliis, immobilize the parasite in vitro. In order to identify ceil surface antigens involved in the immobilization response, integral membrane proteins were extracted from tomites with Triton X‐l14 and used to immunize rabbits. The rabbit antisera immobilized the parasite in vitro and antigens were localized to cell and ciliary plasma membranes by indirect immunofluorescent microscopy. The membrane protein fractions from both whole cells and tomite cilia were characterized by 1 ‐ and 2‐dimensiona! SDS‐PAGE. A 43,000‐dalton (D) glycoprotein with an isoelectric point of 7.0 is the predominant protein in these fractions, comprising 12% and 60% of the total protein of whole cell and ciliary membranes, respectively. Western blot analysis of ciliary proteins with immune rabbit sera indicated that the 43,000‐D glycoprotein is the princi

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1989.tb01065.x

出版商:Blackwell Publishing Ltd    

年代:1989

数据来源: WILEY