bluuebunny/crossref_metadata_2025_split huggingface dataset:
Trypanosoma cruzi: Analysis of the Population Dynamics of Heterogeneous Mixtures1
Authors: Finley Richard W. , Dvorak James A. 
Published: May 2007

ABSTRACTUtilizing the previously reported inter‐clonal differences in total DNA/organism, flow cytometry was used to analyze the population dynamics of Trypanosoma cruzi clone mixtures growing in liquid medium or vertebrate cells. The growth of clone mixtures in liquid medium can be described by unique parameters reflecting exponential growth rate (r), stationary phase population density (1/k), and the interaction between the clones (h). The relative numbers of each clone in the population change rapidly with time and the results arc in quantitative agreement with mathematical models of competitive population growth. The relationship between the parameters for T. cruzi is such that, in general, there is no dynamic equilibrium with coexistence of clones with different growth rates; under all culture protocols, the faster growing clone will prevail. A computer simulation of the vertebrate cell cycle of T. cruzi suggests that clone mixtures grow relatively independently; the basic attributes of the model were substantiated experimentally. Although wide fluctuations in the proportion of each clone released occurred, the faster growing clone again predominated. Finally, these results underline the importance of working with well‐defined clones in the laboratory to avoid inconsistencies and paradoxical results and stress the importance of the rapid isolation of single cell clones from clinical specimens when studying the relationship of the parasite to human disease.
Multiple Sequence Versions of the Oxytricha fallax 81‐MAC Alternate Processing Family1
Authors: Herrick Glenn , Cartinhour Samuel W. , Williams Kevin R. , Kotter Kenneth P. 
Published: May 2007

ABSTRACTThe 81‐MAC family consists of three sizes of macronuclear chromosomes in Oxytricha fallax. Clones of these and of micronuclcar homologs have been classified according to DNA sequence into three highly homologous (95.9–97.9%), but distinct versions. Version A is represented by a micronuclear clone and by clones of two different‐sized macronuclear chromosomes, showing that alternate processing of micronuclear DNA is responsible for the variety of sizes of macronuclcar chromosomes. Three Internal Eliminated Sequences (IES's) are demonstrated in Version A micronuclcar DNA. Two have been sequenced and show short, flanking direct repeats but no inverted terminal repeats. Version C micronuclear DNA has interruptions in the macronuclear homology which correspond closely to the Version A IES's. Whether they are true IES's is unknown because no Version C macronuclear DNA has been demonstrated. Version C micronuclear DNA may be “macronuclear‐homologous” but “micronucleus‐limited” and not “macronucleusdestined.” Version B is represented by macronuclear DNA clones, but no micronuclear clones. Vegetative micronuclear aneuploidy is suggested. The possible role of micronuclear defects in somatic karyonidai senescence is discussed in light of the precise macronuclear chromosome copy controls demonstrated within the 81‐MAC family. These controls apparently operate throughout karyonidai life to mairitain 1) a constant absolute amount of 81‐MAC sequences in the macronuclcus and 2) a constant sioichiometry within the family, both according to version and chromosome size.
Effect of Biogenic Amines on Phagocytosis in Tetrahymena thermophila1
Authors: Quiñones‐Maldonado Vanya , Renaud Fernando L. 
Published: May 2007

ABSTRACTStimulation of phagocytosis by serotonin and catecholamincs in Tetrahymena grown in proteose‐peptone medium proved to be concentration dependent, the optimal concentrations being ∼0.1 to 1.0 μM. The serotonergic antagonists, spiperone, and metergoline, also stimulated the process, whereas the β‐ and α‐adrenergic antagonists, propranolol, alprenolol, and ergocryptine, had no effect or inhibited phagocytosis. A wide variety of derivatives of the biogenic amines had no effect on phagocytosis, demonstrating the specificity of recognition mechanism for neurohormones in Tetrahymena. Such hormones act by at least two independent mechanisms, one for adrenergic agonists, another for dopamine. Presumably, recognition mechanisms for hormones in protozoa resemble in some respects those in multicellular organisms, therefore bespeaking a common origin.
Two New Species of Coccidia (Apicomplexa: Eimeriidae) from Madagascar Gekkonids
Authors: Upton Steve J. , Barnard Susan M. 
Published: May 2007

ABSTRACTTwo new species of coccidia (Apicomplexa: Eimeriidae) are described from the Madagascar giant day gecko, Phelsuma madagascariensis grandis, and the Golddust day gecko, P. laticauda. Both species of coccidia were found to infect the anterior one‐half of the small intestine. Oocysts of Eimeria brygooi n. sp. are spherical or subspherical, 23.0 × 21.3 (18.8–25.2 × 16.4–23.2) μm; shape index (L/W) 1.1 (1.0–1.2). A micropyle, oocyst residuum, and polar granule are absent. Sporocysts are ovoid, 9.2 × 7.9 (8.0–10.0 × 7.2–8.8) μm; shape index 1.2 (1.0–1.3), with a Goussia‐type suture; Stieda and substieda bodies are absent. A sporocyst residuum is present, 4.2 × 3.0 (3.2–6.4 × 2.4–4.0) μm. Sporozoites are elongate, with anterior and posterior refractile bodies. This coccidian was found to infect five of six (83%) P. m. grandis and one of five (20%) P. laticauda examined. Oocysts of Isospora gekkonis n. sp. are spherical or subspherical, 24.2 × 22.0 (21.6–26.4 × 20.0–23.6) μm; shape index 1.1 (1.0–1.2). A micropyle and oocyst residuum are absent; polar granule present. Sporocysts are ovoid, 12.2 × 9.4 (11.2–12.8 × 8.4–10.0) μm, with Stieda and substieda bodies; shape index 1.3 (1.2–1.4). A sporocyst residuum is present, cither compact, 5.1 × 4.2 (4.0–7.2 × 3.2–5.6) μm or diffuse. Sporozoites arc elongate, with anterior and posterior refractile bodies. Isospora gekkonis was found in two of six (33%) P. m. grandis and one of five (20%) P. laticauda. In addition, oocysts of Cryptosporidium sp. were found in the cloacas of two of six (33%) necropsied P. m. grandis.
Cell Adhesion in Trypanosoma: In Vitro Studies of the Interaction of Trypanosoma vivax with Immobilized Organic Dyes1
Authors: Fish Wallace R. , Nelson Robert T. , Hirumi Hiroyuki 
Published: May 2007

ABSTRACTCertain bloodstream forms of Trypanosoma vivax have been shown to attach to Amicon Matrex™ Gel Green A dye beads in a manner similar to the in vivo binding of T. vivax to the inner surface of the tsetse fly proboscis. We now report an in vitro assay for trypanosome‐bead attachment and show that only the 9,10‐anthraquinone portion of the dye molecule is involved in the binding of trypanosomes to beads and that bead‐bound dyes with similar structures also support binding to differing degrees. The binding is dependent upon the amount of dye on the beads and this, and other evidence, suggests that an array of dye molecules, rather than individual molecules, may be the actual recognition site. Various external effectors, including temperature, soluble protein‐dye complexes, and serum of mice with chronic T. vivax infections, reduce trypanosome binding, indicating that at least one immunogenic trypanosome macromolecule is involved. The trypanosome‐bead interaction mimics the in vivo binding to tsetse proboscis and warrants closer examination as a model of trypanosome cell adhesion in the tsetse fly.
Comparative Analysis of the Fine Structure of Four Isolates of Trypanosomatids of the Genus Phytomonas1
Authors: ATTIAS M. , ROITMAN I. , CAMARGO E. P. , DOLLET M. , DE SOUZA W. 
Published: May 2007

ABSTRACTThe fine structure of trypanosomatids from the plants Euphorbia hyssopifolia, E. characias, E. pinea, and Manihot esculenta, cultivated under axenic conditions, was compared. All parasites had a structural organization characteristic of members of the Trypanosomatidae. The organization of the membranes of the endoplasmic reticulum (ER) varied according to the isolate. In Phytomonas francai (isolated from M. esculenta), the ER cisternae form parallel rows. In Phytomonas sp. from E. characias, a para‐crystalline array of the ribosomes attached to the ER membranes was observed. The ER membranes found in Phytomonas sp. from E. pinea seemed to originate from the central portion of the protozoon, branching in all directions. The peroxisome‐like organelle (glycosome) found in Phytomonas sp. from E. hyssopifolia and E. characias occasionally showed an organized array. Taken together, the morphological observations make it possible to distinguish the four isolates of Phytomonas.
Ultrastructure of Two Types of First‐Generation Merozoites of Eimeria bovis1
Authors: SPEER C. A. 
Published: May 2007

ABSTRACTEimeria bovis has two types of first‐generation merozoites with distinct ultrastructural characteristics. Type I merozoites were relatively large (X = 13.2 times 1.5 μm) and crescent‐shaped, contained numerous micronemes and amylopectin granules, had a posteriorly located nucleus and a conical‐shaped posterior tip, and were highly motile and capable of penetrating cultured cells. Type II merozoites were small (X = 5.9 times 0.9 μm) and spindle‐shaped, had a centrally‐located nucleus, few micronemes, few or no amylopectin granules, a dome‐shaped posterior tip and little motility, and appeared to be incapable of penetrating cultured cells. It is possible that these two types of merozoites have considerably different roles in the life cycle of E. bovis.
Cell Pairing during Mating in Tetrahymena: I. Does Phagocytosis or a Cell Surface Receptor Participate in Con A Block?1
Authors: CASCI ROBERT J. , HUFNAGEL LINDA A. 
Published: May 2007

ABSTRACTThe lectin, Concanavalin A (Con A), inhibits cell pairing during mating in Tetrahymena and binds to the surface of pairing cells via receptors concentrated around the conjugation junction. Concanavalin A is also ingested in large amounts into food vacuoles. To dispel the possibility that Con A inhibits pairing via uptake into food vacuoles or through induction of food vacuole formation and to strengthen the idea that pairing is blocked through binding of Con A to cell surface receptors, we have conducted three types of experiments: 1) attempts to inhibit pairing by feeding with nutrients and with tantalum, a non‐nutritive reagent; 2) a temporal analysis of the presence of food vacuoles in mating cells fed with tantalum; and 3) analysis of the restoration of pairing following the addition of α‐methyl mannoside to cells previously treated with inhibitory concentrations of Con A. The results of these studies support the idea that Con A inhibits pairing by binding to receptors located on the cell surface and not by induction of or uptake into food vacuoles. We also present evidence that cells grown in an enriched proteose peptone medium are able to pair and undergo morphogenesis more readily than cells grown in 2% proteose peptone.
Complete Development of Caryospora bigenetica (Apicomplexa: Eimeriidae) In Vitro1
Authors: SUNDERMANN CHRISTINE A. , LINDSAY DAVID S. , TIBBS ROBERT E. , BAILEY MARK A. 
Published: May 2007

ABSTRACTThe development of Caryospora bigenetica in vitro is described by light microscopy. Sporozoites from snake‐derived oocysts were purified and inoculated onto cultures of primary testicle cells of the cotton rat, cotton rat kidney cells, and human fetal lung cells. Intracellular sporozoites were observed one and two days postinoculation (DPI). Motile, extracellular first‐generation merozoites were present 3 DPI, and second‐generation merozoites were present 5 DPI. Mature gamonts were observed 9 DPI and developed into unsporulated oocysts by 10 DPI. Oocysts sporulated in vitro, and excystation was observed. Cells that were penetrated by in vitro‐produced sporozoites formed caryocysts by 16 DPI. To test infectivity of in vitro‐derived stages, merozoites were removed from cultured cells 5 DPI and inoculated intraperitoneally into a mouse; infection resulted. Sporulated oocysts removed from cell cultures 12 DPI produced facial swelling in an orally inoculated cotton rat.
Trimyema compressum Lackey, 1925: Morphology, Morphogenesis and Systematic Implications1
Authors: SERRANO SUSANA , MARTÍN‐GONZÁLEZ ANA , FERNÁNDEZ‐GALIANO DIMAS 
Published: May 2007

ABSTRACT Trimyema compressum is a species included in the family Trimyemidae with the single genus Trimyema. This species has 50–60 somatic kinetics and three rows of kinetosomes surrounding the oral cavity. Two isolated groups of kinetosomes can also be observed on the right side of the oral region. The morphogenesis of bipartition is telokinetal; all the new infraciliary structures of the opisthe come from the longitudinal and postero‐anterior proliferation of the last kinetosome of all the somatic kinetics. In the proter there is a reorganization of the oral infraciliature.As a result of our observations, we suggest that the systematic position of the genus Trimyema be changed from the subclass Vestibulifera to the subclass Gymnostomata. We also consider that this genus must be included in the suborder Trimyemina Jankowski, 1980.
Changes in the Cytoplasmic Elements of Cultured Cells Infected with Eimeria vermiformis Sporozoites
Authors: ADAMS JOHN H. , BUSHELL GILLIAN R. 
Published: May 2007

ABSTRACTEpithelial‐type (PK‐15) and fibroblast‐type (MDBK) mammalian cell cultures were inoculated with purified Eimeria vermiformis sporozoites. 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 the parasite.
Ichthyophthirius multifiliis Has Membrane‐Associated Immobilization Antigens
Authors: DICKERSON H. W. , CLARK T. G. , FINDLY R. C. 
Published: May 2007

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 principal antigen.
Cytochemical Localization of Plasma Membrane Enzyme Markers During Interiorization of Tachyzoites of Toxoplasma gondii by Macrophages
Authors: CARVALHO LAÍSS DE , SOUZA WANDERLEY DE 
Published: May 2007

ABSTRACTThe enzyme activity of Mg‐ATPase, Na+‐K+‐ATPase, 5′‐nucleotidase and NAD(P)H‐oxidase was cytochemically detected at the ultrastructural level in mouse peritoneal macrophages infected with untreated and with specific antibody‐coated Toxoplasma gondii tachyzoites. The Mg++‐ATPase and 5′‐nucleotidase were distributed throughout the macrophages’plasma membrane but were not observed in the membrane lining endocytic vacuoles containing ingested parasites; however, Na+‐K+‐ATPase activity was detected in the macrophages’plasma membrane as well as in the parasitophorous vacuoles that contained untreated or specific antibody‐coated parasites. Reaction product, indicative of NAD(P)H‐oxidase, was detected in the parasitophorous vacuoles that contained only‐specific antibody‐coated parasites.
The Release of Holospora obtusa from Paramecium caudatum Observed with a New Device for Extended In Vivo Microscopy
Authors: WIEMANN M. 
Published: May 2007

ABSTRACTThe macronudeus‐specilic bacterium Holospora obtusa is released from its host cell Paramecium caudatum generally after a preceding cell division. Before division, most infectious forms of the bacteria can be found in a connecting strand of the dividing macronucleus. This connecting strand is deformed and finally expelled as a whole from the daughter cells. This process was observed and photographed with a simple device allowing observations for a long lime under a microscope without damage to the living cells. Key words. Bacterium, cytoproct, defecation, infection, macronucleus, symbiosis.
The Nuclear Envelope of Amoeba proteus During Mitosis as Studied With a Monoclonal Antibody Against a Membrane‐Associated Protein
Authors: KIM CHONG H. , CHOI EUI Y. , JEON KWANG W. 
Published: May 2007

ABSTRACT. The behavior of nuclear envelopes during mitosis in Amoeba proteus was studied by means of indirect immunofluo‐rescence staining using a monoclonal antibody against a 220‐kD membrane‐associated protein of amoebae in conjunction with DAPI staining of chromatin. The antibody selectively recognized antigens on nuclear envelopes during interphase but did not react with the nuclear membranes during mitosis until after cytokinesis had been completed. Thus, it appeared that the membrane‐associated protein reacting with the monoclonal antibody and normally present on the nuclear membranes was absent from fragmented nuclear membranes or nuclear membranes that were continuous but did not have the honey‐comb lamina. The findings suggested that the 220‐kD nuclear‐membrane protein may be involved in the dissolution and reformation of the honey‐comb lamina during mitosis in amoebae.
Redescription of Flagellar Arrangement in the Duck Intestinal Flagellate, Cochlosoma anatis and Description of a New Species, Cochlosoma soricis N. Sp. from Shrews
Authors: WATKINS RAYCHEL A. , O'DELL WILLIAM D. , PINTER AELITA J. 
Published: May 2007

ABSTRACTCochlosoma anatis Kotlán (Zoomastigophorea, Retortamonadida, Cochlosomidae), isolated from the large intestines of domestic Rouen ducks, and Cochlosoma soricis n. sp., isolated from the small intestines of shrews, were observed by light and scanning electron microscopy. In both organisms, a single flagellum inserted on the dorsal surface at the same level as the insertion of 4 other flagella on the ventral surface. The 4 ventro‐lateral flagella emerged from the left side of the anterior attachment disk below the margin and just above the lateral groove which extended the length of the organism. A 6th flagellum emerged from the margin of the attachment disk. The proximal ends of the flagella formed a bundle with the distal ends becoming unraveled like a rope. During motility, the bundle portion extended straight out from the cell and the free ends of the flagella produced a whipping motion. In C. anatis, the dorsal surface was covered with knob‐like lumps and small pits and the cells had an axostyle that emerged slightly to the right of the midline in the posterior 1/3 of the body. The axostylar tip was shorter and thicker than the flagella and in most cells it also had an irregular, knobby appearance. The irregular cell surface and axostyle were absent from C. soricis. The margin of the attachment disk curved toward the center and terminated in C. anatis as a straight edge while in C. soricis it continued as a spiral. Indentations in the mucosal brush border similar to those produced by Giardia, but distinctly belonging to Cochlosoma, were interpreted as points of attachment to the host.
Culture and Generic Identification of Trypanosomatids of Phytophagous Hemiptera in Brazil
Authors: SBRAVATE CLIZETE , CAMPANER MARTA , CAMARGO LUIS E. A. , CONCHON IVETE , TEIXEIRA MARTA M. G. , CAMARGO E. PLESSMANN 
Published: May 2007

ABSTRACTAmong the 372 phytophagous Hemiptera examined, 133 insects of 28 species (Coreidae 18, Pentatomidae 7, Pyrrhocoridae 2, Lygaeidae 1) were infected with trypanosomatids. Gut infections only were found in 68.4%, gut and salivary gland infections in 29.3% and salivary infections alone in 2.3%. Fifty‐one cultures were isolated from 38 insects. Cultures were characterized by assay of certain ornithinc‐arginine metabolism enzymes and by indirect immunofluorescence against monoclonal antibodies specific for Phytomonas spp. Ten cultures were identified as either Crithidia or Leptomonas. Twenty‐one promastigote cultures had an enzyme pattern hitherto recorded only for Leishmania and 16 cultures were identified as Phytomonas.
Antigenic Reactivity of a Monoclonal Antibody Against Amoeba proteus Actin
Authors: AHN TAE I. , JEON KWANG W. 
Published: May 2007

ABSTRACTThe reactivity of a monoclonal antibody against actin of Amoeba proteus with actins from other sources was examined. The monoclonal antibody cross‐reacted with actins from vertebrate muscles, human erythrocytes, and Acanthamoeba castellanii, but it did not react with Naegleria gruberi actin. The amoeba actin was resolved into 3 bands with isoeletric points of 5.96, 6.03 and 6.10 in electrofocusing gels and they corresponded to 3 peptide spots reacting with the antibody on 2‐dimensional immunoblots.
A Thermostable Acid α‐Glucosidase from Tetrahymena thermophila: Purification and Characterization
Authors: BANNO YOSHIKO , SASAKI NOBORU , YOSHINO TIKAKO , MOCHIZUKI JUN‐ICHIROH , HIRATA HAJIME , NOZAWA YOSHINORI 
Published: May 2007

ABSTRACTAn acid α‐glucosidase (EC 3.2.1.20) was purified to homogeneity from the culture medium of Tetrahymena thermophila CU 399. Its general molecular, catalytic and immunological properties were compared to those of the T. pyriformis W enzyme. The enzyme from T. thermophila was a 105‐kD monomer and the N‐terminus (25 amino acid residues) displayed some homology with that of T. pyriformis enzyme. The purified enzyme was most active at 56° C and showed resistance to thermal inactivation. The acid α‐glucosidase appears to have α‐1,6‐glucosidase as well as α‐1,4‐glucosidase activity. The Km values determined with p‐nitrophenyl‐α‐glucopyranoside, maltose, isomaltose and glycogen were 0.7 mM, 2.5 mM, 28.5 mM and 18.5 mg/ml, respectively. The enzyme was antigenically distinct from T. pyriformis acid α‐glucosidase.
Two New Species of Isospora from the Desert Skink (Chalchides ocellatus) from the Egyptian Desert
Authors: AMOUDI MIKKY A. 
Published: May 2007

ABSTRACTIsospora chalchidis n. sp. and Isospora eimanae n. sp. were isolated from the desert skink, Chalchides ocellatus, order Squamata, from Egypt. Sporulated oocysts of I. chalchidis n. sp. were spheroidal 19 × 19 (18–20.5 × 18–20.5) μm with a 2–layered walled. Oocysts lacked a micropyle and residuum and few polar granules were present. Sporocysts were lemon‐shaped 12.2 × 6.5 (9.5–13 × 5–8) μm with a Stieda body and sporocyst residuum but without a substiedal body. Isospora eimanae n. sp. were spheroidal 18.5 × 18.5 (17–19.5 × 17–19.5) μm with a 2–layered wall. There were oocysts without residuum or polar granule, but with small micropyle at 1 end. Sporocysts were ovoid 12 × 8.5(11–13 × 7.5–9) μm with a small Stieda body and sporocyst residuum but without a substiedal body.