bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphology and Infraciliature of Trochiliopsis australis N. Sp., Pelagohalteria viridis (Fromentel, 1876) N. G., N. Comb., and Strobilidium lacustris N. Sp. (Protozoa, Ciliophora)1
Authors: FOISSNER WILHELM , SKOGSTAD ASBJØRN , PRATT JAMES R. 
Published: May 2007

ABSTRACTThree ciliate species from Australia and Norway were examined by silver impregnation, biometry, and scanning electron microscopy. Trochiliopsis australis n. sp. (order Nassulida, family Microthoracidae) differs from the single other known species of the genus, T. opaca, by its prominent ridges on the left side, the distinctly longer anterior segment of somatic kinety 2, and by the doubled total number of kinetosomes. Pelagohalteria n. g. (order Oligotrichida, family Halteriidae) differs from Halteria by the structure of the bristle complexes, which are composed of a vertically and a horizontally oriented row of kinetosomes. Two Halteria species belong to the new genus: P. viridis (Fromentel, 1876) n. comb., which is redescribed here, and P. cirrifera (Kahl, 1935) n. comb. Strobilidium lacustris n. sp. (order Oligotrichida, family Strobilidiidae) differs from its nearest relative, S. velox, by the smooth pellicle, the absence of symbiotic green algae, and by its larger size.
Con A Binds to the Membranellar and Somatic Cilia of Stentor and to the Developing Oral Primordium During Oral Regeneration1
Authors: MALONEY MICHAEL S. 
Published: May 2007

ABSTRACTBinding sites for Concanavalin A have been located in the ciliate Stentor coeruleus by utilizing FITC‐Con A and fluorescence microscopy. When both nonregenerating and regenerating Stentor are fixed prior to FITC‐Con A exposure, FITC‐Con A binds intensely to the cilia of the membranellar band and to the somatic cilia that cover much of the cell surface. No binding is observed between the ciliary rows. The FITC‐Con A also binds to the developing oral primordia of regenerating cells. Binding of FITC‐Con A in the early stages of regeneration (prior to stage 4) appears to be less intense than that in the later stages. Additional FITC‐Con A binding appeared as a granular fluorescence in the area of the developing buccal cavity beginning at about stage 4 and disappearing around stages 6–7. The presence of α‐D‐methyl mannoside prevented the binding of FITC‐Con A to either regenerating or nonregenerating cells. If nonregenerating Stentor are exposed to FITC‐Con A prior to fixation, the binding pattern is entirely different with the fluorescence primarily in the form of random, granular patches spread over much of the cell but with no binding to either type of cilia. These results demonstrate that membrane glycoproteins capable of binding Con A are located primarily in the membranellar and somatic cilia and in the developing oral primordia during oral regeneration in Stentor. Concanavalin A binding to these sites may be involved in the Con A‐induced inhibition of oral regeneration observed in earlier studies.
Comparison of the Protein Kinase and Acid Phosphatase Activities of Five Species of Leishmania1
Authors: MUKHOPADHYAY NISHIT K. , SAHA ASISH K. , LOVELACE JAMES K. , DA SILVA ROSANGELA , SACKS DAVID L. , GLEW ROBERT H. 
Published: May 2007

ABSTRACTPromastigotes from log phase and stationary phase cultures of Leishmania donovani, L. braziliensis panamensis, L. tropica, L. major, and L. mexicana amazonensis were analyzed for their content of protein kinase and acid phosphatase activities. Cell surface, historic‐specific protein kinase activity was 1.3‐ to 2.8‐fold higher in stationary phase cells of all species except for L. tropica in which the activities of stationary and log phase cells were equal; L. mexicana amazonensis had the highest histone‐specific protein kinase activity and L. donovani the lowest. When viable, motile promastigotes of all five species were incubated for 10 min with [γ‐32P]ATP and Mg2+ (10 mM) in the absence of exogenous histone acceptor; about one dozen proteins were phosphorylated in each case. Both log phase and stationary phase promastigotes of all five species extensively phosphorylated a 50‐kDa protein that had the mobility of tubulin. Incubation of pure calf brain tubulin with [γ‐32P]ATP and purified L. donovani protein kinase resulted in extensive phosphorylation of the former. Highly infective metacyclic forms (PNA‐) of L. major, isolated from a stationary culture using the peanut agglutinin (PNA), contained eight times more histone‐specific protein kinase activity than noninfective log phase cells (PNA+). The PNA‐ and PNA+ forms of L. major both phosphorylated a 50‐kDa protein when incubated with [γ‐32P]ATP and magnesium or manganese ions (10 mM); the 50‐kDa protein was precipitated by anti‐tubulin rabbit antibodies. Extracts of all five species contained large amounts of acid phosphatase activity. With the exception of L. braziliensis panamensis for which late log phase organisms contained 12‐fold more tartrate‐resistant acid phosphatase activity than did early log phase cells, stationary and log phase parasites contained approximately the same amount of acid phosphatase activity.
Duboscquella cachoni N. Sp., a Parasitic Dinoflagellate Lethal to Its Tintinnine Host Eutintinnus pectinis1
Authors: COATS D. WAYNE 
Published: May 2007

ABSTRACTThe parasitic dinoflagellate Duboscquella cachoni n. sp. is described from infestations of the tintinnine ciliate Eutintinnus pectinis collected from the Chesapeake Bay, a major North American estuary located on the east coast of the United States. Examination of parasite life history, morphology, and developmental processes reveals that D. cachoni differs from other members of the genus by the structure of the trophont, the pattern of sporogenesis, and spore morphology. Sporogenesis results in the production of either biflagellated macrospores, microspores with a single flagellum, or a cyst‐like stage. The number of spores formed per infestation and their survival outside the host vary with spore type. Infested ciliates are apparently unable to reproduce, and infestations are always fatal to E. pectinis. Aspects of parasite biology and observations of a natural host‐parasite assemblage suggest that D. cachoni may have a significant impact on its host's population dynamics.
Ultrastructure and Ecology of Calycomonas ovalis Wulff, 1919, (Chrysophyceae) and Its Redescription as a Testate Rhizopod, Paulinella ovalis N. Comb. (Filosea: Euglyphina)1
Authors: JOHNSON PAUL W. , HARGRAVES PAUL E. , SIEBURTH JOHN McN. 
Published: May 2007

ABSTRACTAn exceptional bloom (109 cells/liter) of a unicellular alga, Aureococcus anophagefferens, in Narragansett Bay, RI, was accompanied by unusually high numbers (6 times 106 tests/liter) of vase‐shaped cells of Calycomonas ovalis Wulff, hitherto considered a flagellated chrysophyte. Phase contrast light microscopy showed the characteristic oval lorica or test of C. ovalis, ca. 3.0 times 4.5 μm. Transmission electron microscopy of thin sections of natural populations revealed, however, that C. ovalis is actually a rhizopod within a test of electron‐dense scales. This estuarine, planktonk testacean extends a pseudopodium through a narrow pseudostome and lacks chloroplasts or flagella. It is a bacterivore and feeds primarily on unicellular cyanobacteria. The morphology, ultrastructure, and cell division of C. ovalis are described. These characteristics place C. ovalis with the genus Paulinella (Sarcodina: Filosea: Euglyphina), which at present contains the single species, P. chromatophora Lauterbom. Calycomonas ovalis is thus assigned to Paulinella as P. ovalis n. comb.
Stage Depandent Inhibition of Plasmodiun falcipaium falciparum by Potent Ca2+ and Calmodulin Modulators
Authors: TANABE KAZUYUKI , IZUMO ADIHISA , KATO MAYUMI , MIKI ATSUSHI , DOI SYUICHI 
Published: May 2007

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+ channels or CaM.
The Inositol Lipids of Paramecium tetraurelia and Preliminary Characterizations of Phosphoinositide Kinase Activity in the Ciliary Membrane
Authors: SUCHARD SUZANNE J. , RHOADS DENNIS E. , KANESHIRO EDNA S. 
Published: May 2007

ABSTRACTInositol glycerolipids make up less than 10% of total phospholipids of Paramecium tetraurelia cells. Unlike inositol lipids found in mammalian and other cell types, these lipids from Paramecium lack arachidonic acid. It was demonstrated that kinase and possibly phosphatase enzymes that interconvert phosphatidylinositol (PI), phosphatidylinositol phosphate (PI‐P) and phosphati‐dylinositol‐bis‐phosphate (PI‐P2) exist in ciliary membranes of this ciliate. When exogenous soybean PI and [γ‐32P]ATP were provided as substrates, isolated cilia preparations exhibited PI and PI‐P kinase activities as demonstrated by the incorporation of radiolabel into PI‐P and PI‐P2. Kinase activity was activated by millimolar [Mg2+] and inhibited by millimolar [Ca2+]. Significant inhibition of kinase activity in the presence of unlabeled excess ATP suggested that ATP is the preferred phosphate donor for this reaction. Of 4 suborganellar fractions of isolated cilia, the membrane fraction had the greatest kinase activity indicating that the enzyme(s) is membrane‐associated
Nucleic Acids of Entamoeba histolytica
Authors: ALBACH RICHARD A. 
Published: May 2007

ABSTRACTThis review will concentrate on certain aspects of the nucleic acids of Entamoeba histolytica. Utilization and synthesis of purines and pyrimidines will initially be briefly discussed, e.g. salvage vs. de novo pathways, uptake studies and recognition of at least 4 transport loci. Data will be presented which show that the distribution and synthesis of RNA (to a lesser extent DNA) in the nucleus is basically the opposite one finds in other eukaryotes, viz. most RNA (ribosomal?) is synthesized (or accumulates) in the peripheral chromatin (functional equivalent of nucleolus?). The DNA is distributed and synthesized primarily throughout the nucleus. It is usually so dispersed that it will not stain with e.g. the standard Feulgen technique, unless the DNA condenses around the endosome (not a nucleolar equivalent) prior to nuclear division. Isolation of rRNA was difficult due, in part, to potent and difficult to inhibit RNase(s), some of which are apparently intimately bound to ribosomal subunits. The 25S (1.3 kDa), 178 (0.8 kDa) and 58 rRNA were recovered after isolation with a high salt SDS‐DEP technique. This is the only procedure which enables us to obtain high yields of 258 rRNA: guanidine or guanidinium which permits isolation of intact functional mRNA results in isolation of small amounts of 28 RNA relative to 178 RNA. The 258 RNA is “nicked” (apparently during nuclear processing) and dissociates readily into 1 78 (0.7 kDa) and 168 (0.6 kDa) species, and a more rigidly bound 5.88 species. A small amount of “unnicked” 258 RNA was recovered with guanidine. Two DNA‐dcpendent RNA polymerases (I and II) with a pronounced preference for denatured DNA as template were eluted from DEAE‐Sephadex in reverse order of what occurs in other eukaryotes, except Physarum polycephalum. This conclusion was based on salt optima and alpha‐amanitin sensitivity studies. Initial characterization of DNA isolated with a procedure capable of isolating > 100‐kbp Leishmania DNA showed that undigested DNA migrates as a broad band between markers 6 and 24 kbp. The persistent recovery of such a “band” by us and Perez‐Mutul et al. no larger than ca. 24 kbp (with the exception of >48 kbp DNA isolated by Hernandez et al. using an in situ lysis technique which did not include a proteinase) may be due to nicks introduced during isolation; or, perhaps much of the amebal DNA exists in vivo as gene sized fragments. However, preliminary data generated using orthogonal pulse‐field agarose gel electrophoresis do suggest that amebal DNA may be in small chromosomes.
Hydrogen Production by Rumen Holotrich Protozoa: Effects of Oxygen and Implications for Metabolic Control by In Situ Conditions
Authors: HILLMAN D. LLOYD. K. , YARLETT N. , WILLIAMS A. G. 
Published: May 2007

ABSTRACTExperiments with washed suspensions of holotrich protozoa (Isotricha spp. and Dasytricha ruminantium) showed that both organisms have an efficient 0,‐scavenging capability (apparent Km values 2.3 and 0.3 μM, respectively). Reversible inhibition of H2, production increased almost linearly with increasing O2 up to 1.5 μM; higher levels of O2 gave irreversible inhibition. In situ determinations of H, CH4, O2, and CO2, in ovine rumen liquor, using a membrane inlet mass spectrometer probe, indicated that O2, was present before feeding at 1‐1.5 μM and decreased to undetectable levels (<0.25 μM) within 25 min after feeding. A transient increase in O2. concentration after feeding occurred only in defaunated animals and resulted in suppression of CH4 and CO2 production. The presence of washed holotrich protozoa decreases the O2 sensitivity of CH4 production by suspensions of a cultured methanogenic bacterium Methanosarcina barkeri. It is concluded that holotrich protozoa play a role in ruminal O2 utilization as well as in the production of fermentation end products (especially short‐chain volatile fatty acids) utilized by the ruminant and H, utilized by methanogenic bacteria. These hydrogenosome‐containing protozoa thus both control patterns of fermentation by influencing O2 levels, and are themselves regulated by the low ambient O2 concentrations they experience in the rumen.
Action of the Major Protease from Entamoeba histolytica on Proteins of the Extracellular Matrix
Authors: SCHULTE WERNER , SCHOLZE HENNING 
Published: May 2007

ABSTRACTThe action of the major protease from the parasitic protozoon Entamoeba histolytica, a cysteine protease of M, 27,000–29,000, on some important proteins of the extracellular matrix has been studied. The isolated protease degraded the extracellular matrix proteins from human tissue collagen type IV and V as well as laminin and fibronectin with different velocities and specificities under native conditions. Whereas the degradation of fibronectin and laminin proceeded rapidly, yielding distinct fragment patterns, the breakdown of the collagen types happened more slowly and incompletely. The digestion of the denatured isolated α2‐chain of bovine collagen type I was very fast and unspecific requiring only 1/10 of the enzyme activities as compared with the other substrates mentioned above. Nearly 85% of the overall proteolytic activity of a soluble fraction of E. histolytica was strongly inhibited by antibodies against the purified histolytic protease as well as by cystatin from chicken egg white, a specific protein inhibitor of cysteine proteases. We conclude that the histolytic protease represents by far the highest portion of soluble proteolytic activity in E. histolytica which is sufficient to destroy the extracellular matrix of the host.
Breakdown of Glucopolysaccharides in Entamoeba histolytica by Phosphorylase
Authors: WERRIES ECKHARD , THURN INA 
Published: May 2007

ABSTRACTHomogenates of trophozoites of Entamoeba histolytica released glucose 1‐phosphate from amylopectin, glycogen, and amylose in a ratio of 100:78:74 at glucopolysaccharide concentrations of 0.1%. By use of self‐generating Percoll gradients this activity was shown to be particulate and associated with glycogen. The phosphorylase was extracted from the 40,000 g pellet in aqueous medium and purified to homogeneity by gel filtration on Fractogel TSK HW‐55(F) followed by chromatography on Blue Sepharose CL‐6B. The purified enzyme was active not only against the glucopolysaccharides but also on dextrins with more than 3 glucose moieties, which were primarily formed by the action of amoebic amylases. At substrate concentrations of 1 mM nonreducing ends of each glucan, the phosphorolysis rate of the branched polysaccharides was about 1.75 × 104 times higher than those of the maltodextrins. By means of HPLC the sequential degradation of 4‐nitrophenyl‐maltoheptaoside (G7‐pNP) was studied. Native phosphorylase exhibited a relative molecular mass of Mr= 200,000 by gel filtration and gel electrophoresis. The SDS electrophoresis, under reducing conditions, indicated that the native enzyme was a dimer. Optimal degradation of the polysaccharides and dextrins was achieved at pH values of 7.5 and 7.0, respectively.
Isospora viridanae N. Sp., an Intranuclear Coccidian Parasite from the Canarian Skink, Chalcides viridanus (Lacertilia: Scincidae)
Authors: MATUSCHKA FRANZ‐RAINER 
Published: May 2007

ABSTRACTA caryotropic species of coccidium, Isospora viridanae n. sp. (Apicomplexa: Eimeriidae). has been found as a parasite in the Canarian skink, Chalcides viridanus Gravenhorst, 1851, from Tenerife, Spain, and is described here as a new species. Fully sporulaled oocysts of Isospora viridanae are spherical and measure 21.6 (1 7.6–23.4) nm in diameter. Mtcropyle, oocyst residuum and polar granule are ali absent. Oocysts of this coccidian, with a smooth bilayered wall, contain 2 ovoid sporocysts 13.2 (11.7–14.0) by 9.5 8.2–10 5) μm. A sporocyst residuum is present as well as a Stieda body and a substieda body. Most oocysts are found to be at the beginning of sporulanon when excreted and show 2 spherical sporoblasts. Sporulation is completed within 24 to 48 h at 23 × 2°C Sporozoites are 13–14 μm long and are about 2.5–3 μm wide. Endogenous stages of schizogony and gamogony develop in the nuclei of epithelial cells from the small intestine of the skink. Comparisons with other species of the genus found in lacertilian hosts indicate that it is a new species.
The Effect of Interleukin‐2 on Parasitemia and Myocarditis in Experimental Chagas' Disease
Authors: HULSEBOS LARRY H. , CHOROMANSKI LESZEK , KUHN RAYMOND E. 
Published: May 2007

ABSTRACTPrevious investigations showed that interleukin‐2 (IL‐2) administered in vivo into mice infected with Trypanosoma cruzi reduced levels of parasitemia and increased longevity. Present experiments examined the effect of administration of different doses of IL‐2 at different times during infection in mice on parasitemia and histopathoiogy of heart tissue. Two different doses of IL‐2 (1,500 or 10,000 U) given at 3 different times during infection were equivalent in reducing parasitemia. All of the IL‐2 treated groups of mice had significantly lower numbers of circulating trypomastigotes as compared with controls not receiving this fymphokine. This IL‐2 treatment of T. crazi‐infected mice resulted also in lower numbers of pseudocysts in all 4 ventricular regions in the hearts. This was particularly evident in the more severely infected right ventricular wall; however, a similar decrease was not as apparent in the less severely infected left ventricular wall. The IL‐2 treated, infected mice showed minimal or no effect in reducing inflammation of myocardial cells. However, the mildest inflammation of ventricular wall tended to occur in mice receiving IL‐2 treatment either as a low dose (1,500 U) or a high dose (10,000 U) at 5, 7 and 9 days after infection as compared with mice treated later on. It was concluded that IL‐2 treatment of infected mice produced a significant decrease in parasitemia and decreased infection of myocardial cells. Key words. Heart, histopathoiogy, inflammation, lymphokine, myocardial cells, pseudocyst, Trypanosoma cruzi.
Monoclonal Antibodies Specific for Members of the Genus Endotrypanum
Authors: LOPES ANGELA HAMPSHIRE C. S. , McMAHON‐PRATT DIANE 
Published: May 2007

ABSTRACTTwenty‐six monoclonal antibodies were produced against membrane‐enriched preparations of Endotrypanum schaudinni or Endotrypanum sp. promastigotes. Fifteen of these monoclonal antibodies (E1‐E15) reacted only with the standard strain of E. schaudinni, M6159. Monoclonal antibodies E16‐E26 were considered Endotrypanum specific; no cross reactivity was detected with any other genus of the family Trypanosomatidae (Leishmania, Trypanosoma, Leptomonas. Herpetomonas or Crithidia) by dot‐blot radioimmune assay. By indirect immunofluorescence assay, the antigens recognized by Endotrypanum specific monoclonal antibodies appear to be associated with the surface of the parasite. Based on Western blot analysis, 4 antigenic molecules ranging in molecular weight from 24 kD to 160 kD were identified by monoclonal antibodies specific for the strain of E. schaudinni, M6159. Monoclonal antibodies specific for the genus Endotrypanum identified an antigen of molecular weight 48 kD as well as a diffuse component migrating with an apparent molecular weight of 64–200 kD.
Development, Characterization, and Use of Monoclonal and Polyclonal Antibodies against the Myxosporean, Ceratomyxa shasta
Authors: BARTHOLOMEW J. L. , ROHOVEC J. S. , FRYER J. L. 
Published: May 2007

ABSTRACTBoth monoclonal and polyclonal antisera were produced against Ceratomyxa shasta. Ascites containing trophozoites of the parasite was collected from infected fish and used as antigen for immunization of mice. The resulting monoclonal antibodies reacted specifically with trophozoite and sporoblast stages but did not react with C. shasta spores by either indirect fluorescent antibody techniques or in Western blots. This indicates that some C. shasta antigens are specific to certain life stages of the parasite. Polyclonal antiserum was produced in a rabbit by injecting a spore protein electro‐eluted from an SDS‐polyacrylamide gel. This antiserum reacted with both trophozoites and spores by indirect fluorescent antibody techniques and in Western blots. All antisera were tested for cross‐reactivity to trout white blood cells, a contaminant of the ascites, and to other myxosporea. Two monoclonal antibodies reacted with white blood cells and myxosporea of the genera Sphaerospora and Myxobilatus. One hybridoma produced antibodies of high specificity for C. shasta pre‐spore stages. This is the first report of a monoclonal antibody produced against a myxosporean parasite.
Binary Fission of Pneumocystis carinii Trophozoites Grown in Vitro
Authors: RICHARDSON J.D. , QUEENER S.F. , BARTLETT M. , SMITH J. 
Published: May 2007

ABSTRACT.Trophozoites grown in vitro were shown to undergo binary fission by transmission electron microscopy (TEM). Standard fixation with subsequent embedding in Spun‐ was employed using 3% glularaldehyde and 1% osmium tetroxide with 5% sucrose added to both fixatives and 0.1 M cacodylate buffer washes. Trophozoites were grown on WI‐38 cells in vitro. Trophozoites were found in various stages of fission. The dividing trophozoite has daughter cells that arc rounder than the pleomorphic, non‐dividing trophozoites. Tubular forms external to the dividing trophozoites were decreased in number, tubular forms when present were concentrated around the forming sepia. Nuclear material was sometimes, but not always, well defined in both daughter cells. There was no concentration of nuclear material at the poles. Vacuoles without membrane were present in the dividing forms. Separate nuclear regions were sometimes found in the dividing trophozoites. These observations suggest that binary fission does occur in culture; however, the significance of binary fission to the life cycle of Pneumocystis carinii (Pc) is not yet clear.