bluuebunny/crossref_metadata_2025_split huggingface dataset:
Die Entwicklung von Acanthamoeba castellanii zur Cyste mit und ohne Veränderung des Genaktivitätsmusters*
Authors: JANTZEN H. 
Published: May 2007

ZUSAMMENFASSUNGDie Hemmung der mitochondrialen DNS‐Snythese von Acanthamoeba castellanii der logarithmischen Wachstumsphase durch Äthidiumbromid induziert die stationäre Wachstumsphase, in deren Verlauf Cysten gebildet werden. Diese Cystenbildung ist, im Gegensatz zu der durch Sauerstoff oder Nahrungsmangel hervorgerufenen, nicht von einer in DNS‐RNS‐Hybridisierungen nachweisbaren Synthese qualitativ neuer RNS‐Arten begleitet.Wahrend der durch Äthidiumbromid, Sauerstoff‐ und Nahrungsmangel induzierten stationären Wachstumsphase und Encystierung findet eine starke Reduktion des [3H]Uridin‐Einbaus in die RNS statt; davon ist die ribosomale stärker als die niedermolekulare RNS betroffen.In der durch Äthidiumbromid induzierten stationären Wachstumsphase und in der späten 1WP sind in der RNS weniger DNS‐ähnliche RNS‐Arten vorhanden als in der frühen logarithmischen Wachstumsphase.
L'Appareil Fibrillaire Buccal Isolé de Turaniella vitrea et son Evolution au Cours de la Stomatogenèse
Authors: et Jean Grain FRANCINE IFTODE 
Published: May 2007

RESUME. L'isolement de l'appareil buccal de Turaniella permet une description précise de l'architecture des fibres dont il est constitué. Les changements dans la forme et la cohésion de ces fibres au cours de la stomatogénèse ont été suivis. Leur disparition dans le proter au début de la division est confirmée; leur reconstitution chez les tomites après la division est très lente. Des digestions protéolytiques et des colorations spécifiques montrent que les fibres buccales sont de nature protéique avec une forte tendance à la basicité.SYNOPSIS. A light microscopic study of the isolated buccal apparatus of Turaniella vitrea, a hymenostome peniculine ciliate, resulted in an accurate description of the fibers constituting this apparatus. Changes in shape and cohesion of the fibers during stomatogenesis were also followed. The loss of the fibers in the proter early in division was confirmed. Their reconstitution in the tomites following division was found to be very slow. It was demonstrated with the aid of cytochemical methods and proteolytic enzyme digestion that the fibers consist of mostly basic proteins.
Light and Electron Microscopic Observations on the Heterotrich Ciliate Climacostomum virens
Authors: PECK ROBERT , PELVAT BERNARD , BOLIVAR IGNACIO , DE HALLER GERARD 
Published: May 2007

SYNOPSIS. Alveolar membranes and an epiplasm exist under the cell membrane of the noncontractile heterotrich ciliate Climacostomum virens. Postciliary microtubular ribbons join at the right of each somatic kinety to form a Km fiber. Two transverse microtubular fibers occur per kinetosomal pair. A myonemal network interconnects the kinetosomal bases intrakinetally and interkinetally. Ultrastructural comparisons are made between the contractile and noncontractile heterotrichs.The buccal cortex consists of an adoral zone of membranelles, a peristomal field, a buccal tube, the apical membranelles, and a haplokinety. The kineties of the peristomal field and buccal tube are rows of paired kinetosomes, with a postciliary ribbon of microtubules arising from the posterior kinetosome of each pair, and a transverse ribbon and an oblique ribbon from the anterior kinetosome. No Km fibers exist in this region. The haplokinety is a collar of paired kinetosomes surrounding the cytostome; a postciliary microtubular ribbon descends from each kinetosomal pair into the cytostomal region. Ultrastructural details of the buccal cortex of C. virens and other heterotrichs are compared. The nemadesmata which lie under the membranelles are implicated in the body bending of C. virens.Algae endosymbiotic in the cytoplasm of C. virens are described.
Scanning Electron Microscopy of Stomatogenesis Accompanying Conjugation in Euplotes aediculatus*
Authors: KLOETZEL JOHN A. 
Published: May 2007

SYNOPSIS. The succession of morphologic changes in the feeding apparatus (peristome) accompanying conjugation and postconjugant development in the hypotrich Euplotes aediculatus has been examined by scanning electron microscopy (SEM). The details of stomatogenesis inferred from earlier light‐microscopic studies of silver‐stained preparations have been confirmed and extended.The elaborate peristome is the dominant surface feature of vegetative Euplotes. In conjugation, the ciliates are joined in their peristomial regions; as the conjugants separate, the old feeding apparatus is seen to be disrupted and partially resorbed. In its place is the crescent‐shaped primordium of a new peristome, which develops as part of a general cortical reorganization. This primordium expands anteriorly, unfurling a new crown of ciliary membranelles that soon replaces the remaining preconjugant membranellar band. The resulting “exconjugant peristome'’is characterized by a greatly reduced number of adoral membranelles and the absence of paroral membranelles, buccal cavity, and cytostome. Exconjugants thus cannot feed for 2–3 days, until the missing peristomial components are replaced. This occurs by means of a 2nd cortical reorganization, during which new membranelles, developing from another peristomial rudiment, are added directly to the abbreviated exconjugant set. A new buccal cavity is concurrently sculpted as the primordial depression enlarges, and the cells can resume feeding sometime during the 4th day after separation.The implications of this mode of stomatogenesis and the nonfeeding condition are discussed, as are the advantages of SEM for studies of ciliate morphogenesis.
The Life Cycle of the Histophagous Ciliate Tetrahymena corlissi Thompson, 1955*
Authors: LYNN DENIS H. 
Published: May 2007

SYNOPSISThe life cycle of Tetrahymena corlissi Thompson, 1955, is described from organisms fed on tissue of the oligochaete Enchytraeus. The trophont stage usually divides twice either while free‐swimming or encysted as a tomont. The tomont stage apparently occurs only when the trophont is removed from the “conditioned” tissue environment. The time to completion of division is constant and determined at the onset of exposure to tissue. The number of divisions is a function of the amount of tissue ingested. Tomites differentiate after the divisions as active theronts. This dispersal stage transforms to a trophont when tissue is ingested. If tissue is absent, the theronts become smaller, eventually settling on the substrate as immotile pyriform resting theronts, with a small proportion of the resting theronts encysting within a delicate cyst wall. When stimulated chemically or mechanically, the resting theronts transform to active theronts. If these active theronts ingest tissue, they transform to immature trophonts, initially incapable of division. Life cycle and morphologic dissimilarities among T. corlissi, T. bergeri, and T. rostrata are presently used to distinguish among these species.
Quelques Précisions sur L'ultrastructure de Sarcocystis tenella. I. L'endozoïte (Après Coloration Négative)*
Authors: PORCHET‐HENNERE E. 
Published: May 2007

RESUMEDes préparations en coloration négative d'endozoïtes de Sarcocystis tenella ont permis de préciser certains points de sa structure. Le conoïde est constitué d'une vingtaine de fibres obliques et surmonté d'anneaux à ornementation régulière. A l'intérieur du conoïde, et en position excentrée, existent 2 microtubules parallèles qui plongent assez profondément dans le cytoplasme sous‐jacent. Les fibres du conoïde, les microtubules intraconoïdaux semblent avoir la même épaisseur et la même structure que less 22 microtubules sous pelliculaires. Ceux‐ci sont “cimentés” vers l'avant en un collier périconoïdal qui coulisse autour du conoïde. La paroi, d'aspect “réticulé” présente quelques différenciations: le micropore cerclé d'un élément “fibrillaire,” une dizaine de structures subcirculaires en couronne vers l'avant, et 11 lignes de granulations convergeant vers le pôle postérieur. Les sarconèmes se présentent comme des navettes indépendantes les unes des autres et, contrairement aux estimations précédentes, il est établi qu'il n'existe que 2 rhoptries.SYNOPSISThe employment of negative staining technics for the endozoites (cyst stages) of Sarcocystis tenella allowed the elucidation of certain aspects of their fine structure. The conoid consists of ∼ 20 oblique fibers and is surmounted by a ring with regular ornamentation. In the conoid's interior there are 2 excentric parallel microtubules which extend posteriorly for a considerable distance into the adjacent cytoplasm. The fibers of the conoid, the intraconoid microtubules, appear to have the same diameter and structure as the 22 subpellicular microtubules. They are “cemented” anteriorly into a periconoidal ring which surrounds the conoid. The “reticulated” pellicle has certain differentiations: the micropore, surrounded by a “fibrillar” element, ∼ 10 subcircular structures arranged into an anterior crown, and 11 rows of granules converging toward the posterior end. The sarconemes look like rice grains which, contrary to previous statements, are independent of one another. It is established that there are only 2 rhoptries.
Comparative Studies on Related Free‐Living and Pathogenic Amebae With Special Reference to Acanthamoeba*
Authors: VISVESVARA G. S. , BALAMUTH W. 
Published: May 2007

SYNOPSISComparative studies were conducted on the structure, nutrition, protein composition, immunology, and effect on cell cultures of Acanthamoeba sp. (Lilly A‐1 strain), A. castellanii (Singh and Neff strains), A. astronyxis, A. comandoni, A. polyphaga, A. terricola, Hartmannella vermiformis, and Naegleria gruberi. Lilly A‐1 strain of Acanthamoeba received special attention owing to its pathogenicity for experimental animals. Distinct differences were noted in structure, nutrition, and antigenic composition of Acanthamoeba spp. and Hartmannella, and it was concluded that their recognition as separate genera is justified.With the exception of A. terricola, all species of Acanthamoeba could be differentiated by cyst structure. Cysts of A. terricola closely resembled those of A. castellanii Singh strain, and close antigenic relationships between these 2 species were demonstrated by gel diffusion and immunoelectrophoresis (IEP); it was concluded that the 2 amebae belong in the same species.The pathogenic Acanthamoeba sp. Lilly strain differed from the nonpathogenic A. castellanii Singh strain in (a) cyst structure; (b) protein distribution patterns (on disc electrophoresis); (c) soluble and particulate antigens (on gel diffusion, IEP, complement fixation, and immobilization tests); (d) capacity to induce cell‐free plaques and other cytopathic effects (CPE) in mammalian monolayer cell cultures; (e) elimination of a phospholipase, responsible for some of the CPE, into the culture medium, Acanthamoeba sp. Lilly strain, which liberated more phospholipase, produced more CPE.Acanthamoeba sp. Lilly strain differed also from other species of this genus in cyst structure and antigenic composition. It was concluded, therefore, that, following the recommendation of Singh & Das, it ought to be placed in a separate species, Acanthamoeba culbertsoni.
Antigenic Differences Among Epimastigotes, Amastigotes and Trypomastigotes of Trypanosoma cruzi*
Authors: KLOETZEL JUDITH , CAMARGO MARIO E. , GIOVANNINI VERA LUCIA 
Published: May 2007

SYNOPSISAntigenic differences were demonstrated among trypomastigotes, amastigotes, and epimastigotes of Trypanosoma cruzi by the indirect fluorescent antibody method. Tests using cross‐absorbed sera were included in the study.
Symbiote‐Free Hemoflagellates, Blastocrithidia culicis and Crithidia oncopelti: their Liver Factor Requirement and Serologic Identity*
Authors: CHANG K.‐P. 
Published: May 2007

SYNOPSIS. Several aposymbiotic strains of Blastocrithidia culicis and Crithidia oncopelti were cultivated in Trager's chemically defined medium as well as in a blood broth, both supplemented with 0.25% (v/v) liver extract concentrate. For all such strains, the liver extract was found to serve as an essential growth factor in the defined medium and as growth promoting additive in the blood broth. The active molecules were found to be water‐soluble, heat stable, dialyzable, and probably nonlipid fractions.Antisera were developed in rabbit against all the available aposymbiotic strains. An almost total cross‐reactivity at very high titers was observed in reciprocal agglutination test using strains with and without the bacterial symbiotes. These results indicate that the loss of the symbiotes does not affect the antigenic identity of B. culicis and C. oncopelti.
Ultrastructure de Quelques Stades de la Microsporidie Octosporea muscaedomesticae Flu, Parasite de Ceratitis capitata (Wiedemann) (Diptère, Trypetidae)
Authors: ORMIèRES RENE , BAUDOIN JACQUES , BRUGEROLLE GUY , PRALAVORIO RAYMOND 
Published: May 2007

RÉSUMÉLa présence de diplocaryons à tous les stades de la sporulation d'Octosporea muscaedomesticae Flu, 1911 est mise en évidence ainsi qu'une membrane pansporoblastique autour des sporoblastes en développement et des spores. Le problème présenté par ces 2 faits est discuté. Une évolution étrange des ribosomes périnucléaires et démontrée. Une telle étude ultrastructurale est nécessaire et intéressante car O. muscaedomesticae est l'espèce‐type du genre Octosporea.
Observations on Trichosphaerium platyxyrum sp. n.
Authors: ANGELL ROBERT W. 
Published: May 2007

SYNOPSIS. Trichosphaerium platyxyrum sp. n., a marine testate rhizopod, is described. The schizont is ∼ 67 /μm in diameter, sheathed with a membranous test of fibrils and matrix covered with thin, straight, blade‐shaped calcitic spicules. The gamont is ∼ 63 μm in diameter with a membranous test devoid of spicules. The tests of both stages contain circular apertures through which extend short dactylopodia. Locomotion is by lobopodia. Both the schizont and gamont are multinucleate with a mean of 38 nuclei/schizont and 23/gamont. Observed reproduction in both is by binary fission with variations described for the gamont. The type locality is the reef flat of Heron Island, Great Barrier Reef, Australia.It is suggested, but not confirmed, that Schaudinn's description of the life cycle of Trichosphaerium sieboldi may be extended to other species of Trichosphaerium.
Symbiosis in the Larger Foraminiferan Sorites marginalis (with Notes on Archaias spp.)
Authors: MÜLLER‐MERZ EDITH , LEE JOHN J. 
Published: May 2007

SYNOPSIS. It was demonstrated with the aid of light and electron microscope studies that Sorites marginalis (Lamarck) harbors zooxanthellae. The hosts were scraped from Thalassia testudinum Konig growing in Key Largo Sound (Florida, U.S.A.) and immediately preserved in appropriate fixatives. Zooxanthellae were distributed unevenly throughout all the chamberlets; only a few symbiotes were found in the embryonic chambers and the inner or outer chambers, but the intermediate chambers were packed with symbiotes. The outer chambers contained many food vacuoles in addition to symbiotes. Some zooxanthellae might have been in the process of degeneration or digestion. The symbiotes were found to have a typical dinoflagellate nucleus, a single large lobate cortical chloroplast with one stalked pyrenoid, an accumulation body, and many starch granules. The nonmotile stage of the zooxanthella was similar, but perhaps not identical, to Symbiodinium microadriaticum Freudenthal from various hosts.The foraminiferan host is heterokaryotic with hundreds of generative (small) nuclei and scores of vegetative (large) nuclei. Most of the generative nuclei were found in the embryonic apparatus and the inner chambers. Most of the vegetative nuclei were found in the inner and outer chambers.
Effect of Fixation on Demonstration of Phosphatases of Eimeria tenella Grown in Chick Kidney Cell Cultures
Authors: VETTERLING JOHN M. , WALDROP HARRY R. 
Published: May 2007

SYNOPSIS. The effects of fixation with various concentrations of glutaraldehyde or formaldehyde, acetone or ethanol, and freeze‐drying on 5 phosphatases of Eimeria tenella and chick kidney cell cultures were demonstrated in situ. Gultaraldehyde inactivated the phosphatases more than did the formaldehyde, but the effect of the combination of the 2 (Karnovsky's fixative) was greater than that of either glutaraldehyde or formaldehyde alone. The higher the concentration of aldehyde and the longer the duration of exposure, the greater the inactivation. The order of sensitivity to aldehyde fixation of the enzymes tested was glucose‐6‐phosphatase > thiamine pyrophosphatase > 5′‐nucleotidase > adenosine triphosphatase > acid phosphatase. Cytologic detail was preserved more efficiently with glutaraldehyde than with formaldehyde. Optimal preservation of enzyme activity for cytochemistry was with 2% glutaraldehyde for 30 min or 2% formaldehyde for 1 hr for G‐6‐Pase. TPPase, and 5′‐nucleotidase, and with 2% glutaraldehyde or 2% formaldehyde for 2 hr with ATPase and AcPase.Quenching with subsequent fixation in cold acetone or ethanol resulted in complete inactivation of G‐6‐Pase, TPPase, and 5′‐nucleotidase; although cells fixed in this manner yielded large amounts of reaction product for ATPase and AcPase, the distribution was diffuse, and some of it appeared to be artifactual. Quenching with subsequent freeze‐drying was unsatisfactory because nearly all of the cell layers rolled off the cover glasses.
Prevalence and Morphology of Eimeria gadi (Fiebiger, 1913) in the Haddock
Authors: ODENSE P. H. , LOGAN V. H. 
Published: May 2007

SYNOPSIS. The coccidian parasite Eimeria gadi was found in the haddock, Melanogrammus aeglefinus, taken from the Nova Scotian fishing banks. The haddock infection rates ranged from a high of 58% on Emerald Bank to a low of 4% on Georges Bank, the average being 32%. There was no relationship between sex and degree or prevalence of infection. Although the probability of an occurrence of infection increased with size, small fish with heavy infections were observed. The degree of infection had no apparent effect on the condition factor (length/weight) of the fish. The infection rate reached a maximum in the fall of the year while the heaviest infections were observed in the spring. It is evident from the data that the infection is fatal.The parasite mass, appearing as a creamy viscous to a yellow semisolid material in the swimbladder, consisted of various parasite stages, fibrous and cellular debris, and lipid material. Some aspects of the sporocyst stage are described.No other gadoids from the Nova Scotian banks were found to be infected; however, a single specimen of the fourbeard rockling, Enchelyopus cimbrius, from St. John's, Newfoundland, was found to be heavily infected with E. gadi.
Glucolipid Synthesis in Acanthamoeba castellanii*
Authors: SKRDLANT HAROLD B. , WEISMAN ROBERT A. 
Published: May 2007

SYNOPSIS. Cell‐free preparations of Acanthamoeba castellanii trophozoites transfer glucose from UDP‐[U‐14C]glucose to a chloroform‐soluble form. This radioactive material has been isolated by thin‐layer chromatography; it contains an alkali‐labile and an alkali‐stable (unsaponifiable) component. Treatment of the enzymic product with 0.1 N KOH for 15 min at 0 C or 20 C releases radioactivity into the aqueous phase as glucose. During this treatment, 30–60% of the original glycolipid remains chloroform‐soluble. It is considered to be an alkali‐stable glycolipid because no further loss of radioactivity occurs during an additional 45‐min of treatment with 0.1 N KOH. During incubation with 0.1 N HCI at 100 C glucose is released quantitatively from both the untreated glycolipid and the alkali‐stable glycolipid with a half‐time of 6 min. Glycolipid formation is inhibited by UDP and is reversible; extracts catalyze the formation of UDP‐glucose from the alkali‐stable glucolipid and UDP.The chemical and physical properties of the alkali‐stable glycolipid are consistent with a glucosyl phosphoryl polyprenol structure. Extracts prepared from cysts catalyze the formation of glycolipids aiso, but the glucosyltransferase activity/cell decreases during the course of encystment. Radioactivity is incorporated into the fraction insoluble in chloroform‐methanol‐water (1:1:1:) during these incubations when UDP‐[U‐14C]glucose or [14C]glycolipid is the substrate.
Comparative Kinetics of Arginine and Lysine Transport by Epimastigotes and Trypomastigotes from Two Strains of Trypanosoma cruzi*
Authors: GOLDBERG S. S. , PEREIRA A. A. SILVA , CHIARI E. , MARES‐GUIA M. , GAZZINELLI G. 
Published: May 2007

SYNOPSIS. Three‐day‐old cultures of Y and MR strains of Trypanosoma cruzi had a higher rate of lysine and arginine uptake than 10‐day cultures. Amino acid uptake by cells of the MR strain was consistently higher than that of the Y strain.Flagellates separated on DEAE‐cellulose columns have normal structure, motility, and infectivity; they have higher rates of lysine and arginine uptake than the original 3‐ and 10‐day cultures. In addition, passage through DEAE‐cellulose columns modified the kinetic behavior of amino acid transport systems in the flagellate membranes.Methionine inhibited uncompetitively uptake of lysine and arginine by MR and Y strains. Lysine inhibited arginine uptake by both strains by an uncompetitive mechanism. Lysine, however, inhibited the uptake of arginine by 10‐day culture cells of the Y strain by a mixed‐type of inhibition. Arginine also inhibited the lysine uptake of both strains by an uncompetitive mechanism. In all experiments, beyond a certain level, a further increase in inhibitor concentration resulted in a decreased inhibition, which eventually disappeared altogether. Inhibition of amino‐acid uptake by any of the substances tested was not observed after passage of flagellates through a DEAE‐cellulose column.A model for amino acid transport was formulated which includes a recognition site amenable to modulation by effectors.
Adaptation of Leishmania to In Vitro Cultivation at 37 C*
Authors: GILLIG III CLARENCE J. 
Published: May 2007

SYNOPSIS Promastigotes of Leishmania donovani 3S grown in Tobie's modified medium (Tm) at 25 C multiplied at 37 C after short periods of growth at 32 and 35 C. Only inocula from logarithmic phase cultures grew when placed at 32 C. Amastigotes placed at 32, 35, or 37 C became promastigotes but did not multiply upon transfer. The shortest period required for adaptation of 3S promastigotes to 37 C was 44 days (∽66 generations requiring 18 serial transfers). Addition of chick embryo extract to the medium was unnecessary for growth at elevated temperatures. Promastigotes of the Khartoum strain could not be acclimated to temperatures above 35 C.The long‐lasting nature of the adaptation was indicated by (a) ability of 37 C‐acclimated promastigotes to grow at this temperature after 14 serial transfers (∽100 generations) at 25 C, and (b) immediate growth of promastigotes at 37 C in cultures inoculated with homogenized hamster spleen previously infected with 37 C acclimated cells. The ability of the temperature‐adapted promastigotes to grow at 37 C was lost after 30 serial transfers (224 generations) at 25 C. Since sexual reproduction has not been demonstrated in Leishmania, it was impossible to ascertain whether acclimation was a consequence of mutation or represented a dauermodification.