bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amplification of a New Region of DNA in an Unselected Laboratory Stock of L. tarentolae: The T Region
Authors: PETRILLO‐PEIXOTO MARIA L. , BEVERLEY STEPHEN M. 
Published: May 2007

ABSTRACTA new DNA amplification is described from an isolate of the lizard parasite Leishmania tarentolae. This DNA is present in up to 50 copies in the Trager line of this species and present but not amplified in all other lines tested. This amplification has been named the T amplification (for Tarentolae/Trager). Restriction enzyme digestion and electrophoresis of total DNA reveal amplified fragments totalling 19 kb following staining with ethidium bromide, a finding confirmed by the use of specific hybridization probes. Much of the amplified T DNA occurs as extra‐chromosomal circular molecules. No cross‐hybridization was observed between the T region and other amplified DNA of Leishmania, or the maxicircle of L. tarentolae, nor was resistance to methotrexate, chloroquine or primaquine detected in the T‐amplified line. Combined with our previous results showing H region amplification in 2 other unselected lab stocks, these data demonstrate the prevalence of apparently spontaneous gene amplifications in L. tarentolae.
Monoclonal Antibodies for the Identification of Trypanosomatids of the Genus Phytomonas
Authors: TEIXEIRA MARTA M. G. , CAMARGO E. PLESSMANN 
Published: May 2007

ABSTRACTMonoclonal antibodies have been produced against culture forms of Phytomonas francai and Phytomonas serpens parasites, respectively, in cassava roots and tomato fruits. These monoclonal antibodies have been tested against 5 other Phytomonas spp. isolated from plants and 14 species of trypanosomatids of various genera. Monoclonal antibodies were found to react exclusively with Phytomonas spp., always giving negative results with other trypanosomatid genera. Thus, these monoclonal antibodies seem to be an effective tool for the identification of phytomonads among insect trypanosomatids.
Life Cycle and Culturing of Phytomonas serpens (Gibbs), a Trypanosomatid Parasite of Tomatoes
Authors: JANKEVICIUS J. VITOR , JANKEVfCIUS SHIDUCA I. , CAMPANER MARTA , CONCHON IVETE , MAEDA LUCIO A. , TELXEIRA MARTA M. G. , FREYMULLER EDNA , CAMARGO E. PLESSMANN 
Published: May 2007

ABSTRACTPure cultures of a trypanosomatid isolated from tomato fruits infected laboratory‐raised tomatoes and nymphs of the hemipieran coreid Phthia picta. The flagellate could be transmitted back and forth from tomatoes to insects. Light and electron microscopy studies were done on culture, tomato and insect forms. Examination of enzymes of the ornithine‐arginine metabolism revealed absence of arginase and presence of arginine deiminase and citrulline hydrolase. Monoclonal antibodies specific for Phytomonas spp. reacted positively with tomato and insect forms. Endonuclease digestion of the k‐DNA of various Phytomonas spp. revealed a unique, distinctive pattern for the tomato flagellate. This flagellate thus seems to constitute a separate species of Phytomonas which we now call Phytomonas serpens (Gibbs).
Somatic Infraciliature in the Haptorid Ciliate Homalozoon vermiculare (Kinetophragminophora, Gymnostomata) Ditransversalia N. Subcl. and Phylogenetic Implications
Authors: LEIPE DETLEV D. , HAUSMANN KLAUS 
Published: May 2007

ABSTRACTThe ultrastructure of the cortex of Homalozoon vermiculare is described. The ventral side bears 13–15 iongitudinal kineties composed of monokinetids. On the dorsal surface, there are 3 kineties, 2 of which are composed of dikinetids in the anteriormost part of the cell. Consequently there exist 3 different kinds of kinetids within the somatic cortex: 1) The monokinetids on the ventral side are associated with a kinctodesmal fibril, 2 transverse microtubular ribbons and 7 postciliary microtubules in a double‐row configuration; 2) The monokinetids on the dorsal side are very similar but they are associated with just 3 very ‘short postciliary microtubules; 3) The posterior kinetosome of the dorsal dikinetids bears the same fibrillar associates as the dorsal monokinetid, but it lacks the second transverse ribbon. The anterior kinetosome of each pair is associated with a single postciliary’ microtubule. The kinetid organization of Homalozoon is compared to that of other members of the Haptorida. Their phylogeny is discussed. A monophyleiic taxon within the litostomate ciliates is characterized by data on the somatic kinetids, and the new subclass Ditransversalia n. subcl. is constituted. The new subclass comprises the genera Balantidium, Bryophyllum, Enchelydium, Homalozoon, Isotricha, Lacrymaria, Lepidolrachelophyllum, Spathidium and Vestibulongum.
Identification of a cDNA Coding for the SerH3 Surface Protein of Tetrahymena thermophila
Authors: DOERDER F. PALL , HALLBERG RICHARD L. 
Published: May 2007

ABSTRACTWe have identified a Tetrahymena thermophila cDNA‐containing plasmid (pC6) which hybridizes to a 1.47‐kB RNA whose changes in cellular concentration parallel the changes in synthetic rate of a major cell surface protein. From a molecular and genetic analysis of strains expressing the gene (SerH3) encoding this protein, and of strains expressing immunologically distinct alleles of this gene, we conclude that pC6 encodes a portion of the SerH3 allele.
The Somatic Function of the Germ Nucleus in Pseudourostyla cris tat a: Asexual Reproduction and Stomatogenesis
Authors: JIN LI‐PEI , NG STEPHEN F. 
Published: May 2007

ABSTRACTThe micronuclei of the ciliated protozoan Pseudourostyla cristata were eliminated by amputation shortly before binary fusion. The amicronucleate cell lines derived from regenerants were maintained for more than a year. They exhibited a lower viability and reduced vigor in asexual propagation. There was some improvement in the growth of the cell lines 1 mo after operation, but the growth rate remained subnormal even up to 1 yr of culture. The exact cause of the poor growth and survival in the first 3 wk after operation, whether the loss of the micronucleus or operational damage, remains to be determined. It is nevertheless clear that the micronucleus is important for subsequent asexual propagation. The amicronucleate cell lines were permanently crippled in morphogenesis, unlike the situation in Paramecium amicronucleates in which stomatogenesis returned to near‐normal during asexual propagation. They always included some cells with a characteristically defective adoral zone of membranelles, reduced number of frontal‐ventral‐transverse cirri, and reduced body length. They were also reluctant to encyst. It is evident that the micronucleus is important for maintaining normality of the oral apparatus. It is postulated that the permanent stomatogenic crippling of amicronucleates might be related to genomic reduction in the developing macronucleus in sexual reproduction, as exhibited by other hypotrichs. The morphological defects associated with the adoral zone of membranelles may be rationalized as arising from the spreading of a zone of degeneration in the cortex affecting the left edge of the membranelles.
Eimeria tenella: Local Antibodies and Interactions with the Sporozoite Surface
Authors: TREES A. J. , KARIM M. J. , McKELLAR S. B. , CARTER S. D. 
Published: May 2007

ABSTRACT.Using fixed sporozoites in a 3‐layer immunofluorescence assay (TLIFA), class‐specific, parasite‐specific antibody responses in chicks to single‐pulse infection with Eimeria tenella have been studied in gut contents and bile as well as plasma and feces. After infection with 103 oocysts, IgA antibody was first detected in the duodenal lumen, then in bile, plasma, cecum, and the distal small intestine. The kinetics of the bile IgA response correlated with that in plasma and peaked 9 days post‐infection (d.p.i.); IgM was detected in gut contents and bile as well as plasma, and IgG was occasionally detected in gut contents, especially in the duodenum. In some experiments, IgA was detected in gut contents and bile to at least 21 d.p.i. Infection with 103 oocysts resulted in an earlier and increased response and relatively high IgG titers in cecal contents. Coproantibody was detected inconsistently and at low titer. When sporozoites that excysted in vitro were incubated in specific, antibody‐positive (9 d.p.i.) cecal contents, some complement‐mediated IgG‐associated anti‐sporozoite effects were observed; however, the major effect of cecal contents and the only effect of bile was a non‐lethal agglutination of living sporozoites. By fractionation of cecal contents and imtnunoblotting this was confirmed to be IgA mediated; IgA antibodies in cecal contents and bile after infection were shown to bind to sporozoite membrane antigens by surface fluorescence as well as agglutination. Agglutination detected anti‐sporozoite antibody in gut contents and bile up to 21 d.p.i., peaking between 7 and 13 d.p.i., corresponding with TLIFA results. The immunofluorescence studies reveal the extremely labile nature of the sporozoite surface antigens and support the hypothesis that naturally elaborated IgA antibodies are involved in the modulation of complexed sporozoite surface antigens.
Purification and Characterization of Clathrin‐Coated Vesicles from Chlamydomonas
Authors: DENNING GERENE M. , FULTON ALICE B. 
Published: May 2007

ABSTRACTClathrin‐coated vesicles, identified by negative staining with uranyl acetate, were purified from Chlamydomonas rein‐hardtii. Isolated coated vesicles had diameters ranging from 70 to 140 nm (mean diameter±SD of 95±17 nm, n=300). These vesicles were markedly heterogeneous in both density and surface charge, as indicated by equilibrium density sedimentation and elution from anion‐exchange columns. Highly‐purified coated‐vesicle fractions contained 2 major polypeptides, identified as the clathrin heavy chain (185 kDa) and the clathrin light chain (40 kDa). Chlamydomonas clathrin heavy chain cross‐reacts weakly with an antibody against bovine brain clathrin heavy chain. Coat stability in several buffers was compared to that of bovine brain coated vesicles. Stability was similar, except for a greater stability of Chlamydomonas coated vesicles in 0.5 M Tris at pH 7.0.
Morphology and Development of Mirror‐Image Doublets of Stylonychia mytilus
Authors: SHI XINBAI , FRANKEL JOSEPH 
Published: May 2007

ABSTRACTThis paper describes the cortical anatomy and development of mirror‐image doublets of Stylonychia mytilus, analyzed using the protargol technique. The reversed, or “left‐handed” (LH) component of these doublets is a mirror image of the normal or “right handed” (RH) component with regard to the arrangement of cortical structures. The mirror‐image patterning is imperfect, however, as the individual ciliary structures of the LH component all are of normal internal asymmetry, and the orientation of membranelles is inverted. Certain structures that would be expected to form near the line of symmetry are absent. During cell division and cortical reorganization, ciliary primordia arise and become arranged in a mirror‐image pattern that is more perfect than that exhibited by the mature structures. Deviations from a mirror‐image pattern appear at late stages when organelle sets differentiate within ciliary primordia: for example, the membranelle set differentiates within the oral primordium of the LH component in a sequence that is an inversion rather than a mirror image of the corresponding sequence of the RH component. This mixed control of oral development by different cortical “informational systems” accounts for some of the characteristic abnormalities of the mature oral structures of the LH component.
Morphology and Development of Left‐Handed Singlets Derived from Mirror‐Image Doublets of Stylonychia mytilus
Authors: SHI XINBAI , QIU ZIJIAN , LU LI , FRANKEL JOSEPH 
Published: May 2007

ABSTRACTMirror‐image doublets of Stylonychia mytilus include 2 sets of cortical structures, one with the normal “right‐handed” (RH) arrangement, the other with a reversed “left‐handed” (LH) arrangement. These sets, however, are incomplete, with certain structures, most notably cirri of the right marginal type, missing near the line of symmetry. When a mirror‐image doublet is bisected longitudinally to separate the RH and LH components physically, each fragment undergoes a regeneration process that restores a complete set of cortical structures, including the previously missing cirri of the right marginal type. In the resulting LH cell, all ciliary structures are present in an arrangement that is globally reversed in relation to that found in RH cells; in particular, marginal cirri of the left‐marginal type are formed at the cell's right margin, and marginal cirri of the right‐marginal type are produced at the cell's left margin. Whereas the regenerated RH fragment always divides and initiates a clone of normal singlets, the LH fragment, though structurally nearly complete, in all cases eventually dies without dividing. The cause of death is starvation due to the formation of an abnormal oral apparatus. In the Discussion, we consider the nature and consequences of a reversal of global positional information.
Gametogenesis in the Monothalamous Agglutinated Foraminifer Cribrothalammina alba
Authors: GOLDSTEIN SUSAN T. , BARKER WILLIAM W. 
Published: May 2007

ABSTRACTGametogenesis in the foraminifer Cribrothalammina alba involves changes in both the gamontic test and cytoplasm. As gametes begin to differentiate and gametic flagella emerge, pores form in a regular array over the gamontic test, constituting the only avenue for gamete release. The spherical, biflagellated gametes average 1.5μ in diameter and are released in rapidly moving swarms along with flagellated “spherical masses” that probably result from incomplete gametic differentiation. Gametogenesis occurs entirely within the test and utilizes the entire cytoplast. After gamete release is complete, the agglutinated test collapses and disaggregates within a fairly short time. Similar modifications of the gamontic test occur during gametogenesis in Ovammina opaca Dahlgren, but are otherwise unknown among monothalamous agglutinated foraminifera at present.
Continuous Growth and Differentiation of Trypanosoma (Megatrypanum) freitasi Rego, Magalhaes & Siqueira, 1957, In Vitro
Authors: THOMAZ NEIDE , DEANE MARIA P. 
Published: May 2007

ABSTRACTTrypanosoma (Megatrypanum) freitasi, a parasite of didelphid opossum, was known to be very difficult to cultivate in conventional media. Co‐cultivation with L929 cell line in Baltz's medium at 27.5° C resulted in luxuriant growth of the trypanosome with the production of epimastigote colonies that adhered to the surface of culture flasks or tubes, and transformation into metacylics. Further transformation was stimulated by raising the incubation temperature. At 37° C the population was of the bloodstream type and resistant to lysis by complement.
Plasmodium falciparum: Increased and Multiple Invasion During Short Periods of Time
Authors: PAUL VERNOT JEAN , WASSERMAN MOISES 
Published: May 2007

ABSTRACTWe describe how to obtain an increased merozoite invasion of Plasmodium falciparum into human erythrocytes during short periods of time. Using this procedure, infected erythrocytes show multiple invasions (2–4 merozoites per erythrocyte), amplifying, several times, the effects of parasite entry into host cells. The procedure yields synchronous cultures (2‐h age range) with parasitemia as high as 15%. It is possible to reach parasitemia of 50% or higher allowing for a 6‐h invasion period.
Influence of Pregnancy on the Course of Malaria in Mice Infected with Plasmodium berghei
Authors: HIOKI ATSUSHI , HIOKI YUKARI , OHTOMO HIROSHI 
Published: May 2007

ABSTRACTThe course of malarial infection was compared in pregnant mice inoculated with Plasmodium berghei at different stages of gestation. When 12–14 wk old, pregnant BALB/c mice were inoculated with 1 × 106 of P. berghei NK65‐infected red cells at gestation day 0, 2, 4, 6, 8, 10, 12, 14 or 16, the mice inoculated on gestation days 6–12 expired 6.5 days after inoculation compared to 9.5 days in non‐pregnant mice. Parasitemia in these pregnant mice increased rapidly on day 4 after inoculation and anemia also developed earlier on day 5. However, the degree of parasitemia and anemia in the terminal stage of infection in these pregnant mice was milder than that of non‐pregnant controls. Blood urea nitrogen increased at the terminal stage although the degree of increase in mice inoculated on gestation days 6–10 was comparatively small. Pregnant malarial mice died earlier with less physiological changes than non‐pregnant controls. It was concluded that pregnancy makes the host susceptible to physiological changes caused by malaria.
Epizootiology of Amblyospora connecticus (Microsporida) in Field Populations of the Saltmarsh Mosquito, Aedes cantator, and the Cyclopoid Copepod, Acanthocyclops vernalis
Authors: ANDREADIS THEODORE G. 
Published: May 2007

ABSTRACTThe natural ecology of a heterosporous microsporidium, Amblyospora connecticus was investigated at three different salt marsh habitats during 1986–1989. The parasite has a well‐defined seasonal transmission cycle that occurs regularly each year and intimately involves the primary mosquito host, Aedes cantator, and the intermediate copepod host, Acanthocyclops vernalis. In the spring, the microsporidium is horizontally transmitted from the copepod, where it appears to overwinter, to the mosquito via the ingestion of haploid spores produced in the copepod. Mosquitoes develop a benign infection, and females transmit the microsporidium transovarially to their progeny via infected eggs. Oviposition occurs during the summer and infected eggs hatch synchronously in the fall causing widespread epizootics. Infected larvae die, and the cycle is completed when meiospores are released into the pool and subsequently are eaten by A. vernalis, which reappears in the fall and early winter. Amblyospora connecticus thereby persists by surviving in one of two living hosts throughout most of its life cycle rather than in the extra‐corporeal environment. This represents an important survival strategy for A. connecticus as results show the salt marsh habitat to be a relatively unstable environment that is subject to periodic flooding and drying. The adaptive significance of utilizing an intermediate host in the life cycle is discussed as it directly facilitates transmission and enhances survival of the microsporidium.
Enzyme Cytochemistry of the Alveolar Sacs and Golgian‐Like Cisternae in the Ciliate Ichthyophthirius multifiliis
Authors: LOBO‐DA‐CUNHA A. , AZEVEDO C. 
Published: May 2007

ABSTRACTIn the cell cortex of the parasitic ciliate Ichthyophthirius multifiliis different kinds of cisternae were observed: the alveolar sacs, thick membrane cisternae and the endoplasmic reticulum. The thick membrane cisternae possess coated dilated rims and sometimes could be observed close to the endoplasmic reticulum. Using cytochemical techniques acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in the thick membrane cisternae and in the alveolar sacs of trosphozoites. In the endoplasmic reticulum acid phosphatase activity was not detected and only very small amounts of thiamine pyrophosphatase and nucleoside diphosphatase reaction product were observed. After exit from the host, a reduction in acid phosphatase activity was evident in the alveolar sacs. At theront stage acid phosphatase activity is absent from these structures. However, high thiamine pyrophosphatase and nucleoside diphosphatase activities remain in the alveolar sacs during the whole life cycle. On the other hand, acid phosphatase, thiamine pyrophosphatase and nucleoside diphosphatase activities were detected in thick membrane cisternae of theronts. Based on the morphological aspects and enzymatic content the thick membrane cisternae of the cell cortex are designated as golgian‐like cisternae. The cytochemical results point out a relationship between the alveolar sacs and the Golgi complex.
The Effect of Dietary Sterol on the Activity of Fatty Acid Desaturases Isolated from Tetrahymena setosa
Authors: KOLL MARYANNE , ERWIN JOSEPH A. 
Published: May 2007

ABSTRACTTetrahymena setosa has a nutritional requirement for micro amounts of sterol, a requirement which is also satisfied by relatively large amounts of either intact phospholipids or a mixture of unsaturated fatty acids normally found in these ciliates. Three microsomal fatty acyl‐CoA desaturases have been isolated from T. setosa and partially characterized. These enzymes which can account for the formation of the majority of the ciliate's unsaturated fatty acids, include: a Δ9, a Δ12 and a Δ6 desaturase which catalyze the transformation of stearoyl‐CoA to oleic acid, of oleoyl‐CoA to linoleic acid and of linoleoyl‐CoA to ϒ‐linolenic acid, respectively. The stearoyl CoA desaturase required NAD (or NADP), ATP and free CoA; the Δ6 and Δ12 desaturases required NADP, but not ATP or CoA. Cellular levels of the three desaturases were highest in mid‐logarithmic phase cells and lowest in stationary phase cells. In order to determine if there was a relationship between the sterol requirement and the ability of the organism to desaturate, T. setosa was grown in a synthetic medium supplemented with either cholesterol or a phospholipid which permits growth in the absence of cholesterol, or with both phospholipid and cholesterol. Cells grown with phospholipid alone had only half as much stearoyl‐CoA and oleoyl‐CoA desaturase activity as cells of identical culture age grown either on cholesterol alone or on cholesterol plus phospholipid.
A Comparative Analysis of the Morphology and Morphogenesis of Gonostomum strenua (Engelmann, 1862) (Ciliophora, Hypotrichida) and Related Species
Authors: SONG WEIBO 
Published: May 2007

ABSTRACTThe morphology and morphogenesis of the hypotrichous ciliate, Gonostomum strenua, found in the soil of a hill in Qingdao (Tsingtao, 36°08’N, 120°43’E), People's Republic of China is described. Some characteristics (organization of the frontoventral cirral rows, origin of the primary primordium and arrangement of the marginal as well as transverse cirri) are sufficiently different from a closely related species Gonostomum affine to suggest that it is a separate species, though its body shape, nucleus and buccal apparatus are very similar to that of G. affine. A comparison of the infraciliatures of the two species is necessary since morphological characteristics alone are sometimes insufficient for species separation.
NACM, A Cytopathogenic Protein from Naegleria gruberi, EGs; Purification, Production of Monoclonal Antibody, and the Immunoidentification of a Product that Develops in NACM‐treated Vertebrate Cell Cultures
Authors: DUNNEBACKE THELMA H. , DIXON JONATHAN S. 
Published: May 2007

ABSTRACTThe story of NACM involves the discovery of a deleterious response of cultured vertebrate cells to a component in cell‐free lysates prepared from free‐living amebae of the genus Naegleria; hence the acronym NACM derived from Naegleria ameba cytopathogenic material. The cellular reaction is the basis for the biological assay that has been fundamental in the study of the action of NACM in a variety of cell cultures. It also has been used in the determination of the physical characteristics, and to monitor the behavior of NACM during isolation procedures. All findings are compatable with the conclusion that NACM is a 35 Kd protein. Recently, the use of monoclonal antibodies (MAbs) prepared to amebae‐derived purified NACM have resulted in visual display of a product that develops exclusively in NACM‐treated cells. That cellular product is shown to be related to NACM by its immunostaining reaction with the MAb; the relationship of the MAb with NACM is demonstrated by its ability to neutralize the biological activity of NACM, and as an immunostain, to react with purified fractions of NACM and with whole amebae. The combination of these observations describes a unique set of interactions in which NACM, an amebic component, identified as a protein, has characteristics of an infectious agent when introduced into cultures of avian and mammalian cells.