bluuebunny/crossref_metadata_2025_split huggingface dataset:
Three New “Biological” Species of Tetrahymena (T. hegewischi n. sp., T. sonneborni n. sp., T. nipissingi n. sp.) and Temperature Tolerance of Members of the “pyriformis” Complex1
Authors: NYBERG DENNIS 
Published: May 2007

ABSTRACTStocks of the Tetrahymena pyriformis complex have been collected in North America and their mating reactivity has been studied. In addition to stocks mating with Tetrahymena americanis, T. borealis, T. pigmentosa, T. hyperangularis, and T. australis, stocks belonging to old syngen 5 and three new mating groups, numbers 13, 14, and 15, were discovered. Syngen 5 and groups 13 and 14 are distinct “biological” species, based on their reproductive isolation from other groups and on the ability of withingroup crosses to produce immature progeny. These species have been named T. hegewischi n. sp., T. sonneborni n. sp., and T. nipissingi n. sp., respectively. The cross between the two group 15 stocks did not produce immature progeny, and there is not sufficient evidence to conclude that this pair of stocks represents a separate species. Temperature tolerance measurements have been made on stocks representing all known micronucleate members of “pyriformis” complex. Within each species, the range of temperature tolerances is narrow; the average within‐species standard deviation is 0.63°C. The species averages range from 32.7 to 40.7°C. Using syngen numbers, the order from lowest to highest temperature tolerance is 9, 8, 10, 7, 6, 4, 13, 14, 12, 11, 5, 3, 2, 1. The large differences among species make temperature tolerance a useful aid in identification, but the origins of the differences among species are unknown.
An Ultrastructural Study of Phytomonas davidi Lafont (Trypanosomatidae)1
Authors: POSTELL FRED J. , McGHEE R. BARCLAY 
Published: May 2007

ABSTRACTPhytomonas davidi (Trypanosomatidae) possesses typical trypanosomatid organelles: subpellicular microtubules, kinetoplast‐mitochondrial complex, K‐DNA, and four subflagellar pocket microtubules. A greater concentration of subpellicular microtubules was observed in the latex forms than in those found in the salivary glands of its insect vector. Only in the latex flagellates (the stage with postnuclear torsion) were subpellicular microtubules interconnected by crossbridges observed. Morphology and development of mitochondrial aristae varied according to the source of the flagellates. Organisms taken from culture medium had extensively developed plate‐like cristae; sparse tubular cristae were observed in the latex forms; and highly developed tubular cristae were seen in flagellates from the lumen of the vector's salivary glands, though organisms in the salivary gland channels had few or none.
Ultrastructure of the Somatic Cortex of the Gymnostome Ciliate Spathidium spathula (O. F. M.)1
Authors: WILLIAMS DONALD B. , WILLIAMS BENJAMIN D. , HOGAN B. K. 
Published: May 2007

ABSTRACTThe somatic cortex of Spathidium spathula is described ultrastructurally. The pellicle consists of an outer membrane and an underlying alveolar system. Numerous membrane‐bound mucocysts and spherical electron‐opaque bodies have similar circular sites of attachment to the outer membrane. Below these are a microfibrillar zone and an underlying region of rough ER. Mitochondria are lined up under the rough ER in longitudinal cortical ridges. Parasomal sacs are found near the basal bodies and are associated with cytoplasmic membranous sacs. Various microtubular and fiber systems are associated with single basal bodies: (1) a short kinetodesmal fiber; (2) two transverse microtubular ribbons and a transverse fiber; (3) a postciliary microtubular ribbon, initially sandwiched by two fibers, which gives rise to longitudinal subpellicular microtubules extending posteriorly for a distance of some four or five basal bodies; and (4) a system of overlapping subkinetal microtubules. A three‐dimensional reconstruction is included. The somatic cortex of S spathula is similar to that reported for other Haptorida of the ciliate subclass Gymnostomata.
Determination of Macronuclear Fragmentation, Stabilization of Cell Union, and Cessation of Feeding Activity in Triplet Conjugants of Paramecium1
Authors: TAKAGI YOSHIOMI , YOSHIKI YUKO , BABA CHISAKO , YAMADA SEIJI 
Published: May 2007

ABSTRACTTriplet conjugants of Paramecium multimicronucleatum, in each of which the third cell unites by its anterior and to a posterior part of one of the conjugating pair, are induced by conjugation inducing chemicals, KCl and acriflavine in a Ca11‐poor condition. If the triplets are prematurely transferred to medium free of such chemicals, the third cells usually separate and no macronuclear fragmentation occurs in them. But in third cells of long lasting triplets, macromuclear fragmentation regularly begings at ∼12 In after chemical treatment Staluhzaton of cell union and determmation of macronuclear fragmentation occured between ∼100 and ∼130 min after initiation of chemical treatment. Electron‐microscopic observation of the stabilized third cell revealed that the two cell membranes at the uniting region were partially fused to form cytoplasmic bridges. Chemically treated cells began to cases feeding before the cell union and fully ceased such activity at ∼130 min after the treatment.
Virulent and Avirulent Strains of Babesia bovis: The Relationship Between Parasite Protease Content and Pathophysiological Effect of the Strain
Authors: WRIGHT I. G. , GOODGER B. V. , MAHONEY D. F. 
Published: May 2007

ABSTRACTA virulent strain of Babesia bovis (“L” strain) was rendered avirulent by irradiation with 35 krads with a γ source. Another virulent strain of B. bovis (“C” strain) was made avirulent by rapid blood passage through 12 splenectomised calves. Both the parent virulent and their respective avirulent strains were injected into susceptible cattle. A nonfatal disease was observed in those intact cattle that had avirulent parasites; however, a fatal disease was produced in those animals that had received virulent parasites and in splenectomised calves that had received avirulent parasites. Blood kinin levels rose and plasma kininogen levels fell significantly in those animals infected with both virulent strains. Nonsignificant changes occurred with these parameters in animals infected with avirulent parasites. Preparations of disrupted parasites were obtained from the four parasite populations. Both virulent strains contained high levels of protease. The avirulent forms contained insignificant amounts. As parasite doubling times and maximum parasitaemias were the same for all four parasite populations, we conclude that these enzymes are not obligatory for parasite multiplication in the vertebrate host. Their role in producing pathological changes in the host is discussed.
Isolation of a Stearoyl CoA Desaturase from Tetrahymena thermophila
Authors: BERTRAM JON , ERWIN J. A. 
Published: May 2007

ABSTRACTCell free preparations of Tetrahymena thermophila contain an enzyme that catalyzes the direct desaturation of stearoyl CoA to octadecenoic acid. The enzyme is associated with the microsomal fraction of the ciliate. Substrate for the enzyme consists of either free stearic acid or stearoyl CoA. Both ATP and CoA are required when free stearate is the substrate and are also highly stimulatory when stearoyl CoA is the substrate. With stearoyl CoA as the substrate, either NADH or NADPH are required for desaturase activity. In the presence of ATP and CoA, either NAD or NADP can replace NADH and NADPH. Desaturase activity is optimal when the enzyme is incubated at a pH of 7.2 and a temperature of 30–35°C. Highest levels of the stearoyl CoA desaturase are found in stationary phase ciliates grown at 35°C.
Determination of Maximal Growth Rate Using Continuous Culture1
Authors: YEE JOHN , BROEKHOVEN LOUIS , COLGAN PATRICK , HARMSEN RUDOLF 
Published: May 2007

ABSTRACTStudy of microorganism growth kinetics requires measurement of maximal specific growth rate. Standard methods of measurement‐batch, semicontinuous and continuous steady state‐have sources of imprecision that can be substantially reduced by a modification of the continuous steady‐state method. Data are presented, using the ciliate Tetrahymena pyriformis, that indicate that the theoretical foundation of the new method is firm and that precision can be increased.
Variation of DNA Levels in Euglena Related to pH of Culture Medium1
Authors: COOK J. R. 
Published: May 2007

ABSTRACTVariations in DNA levels for log‐phase Euglena have been shown to be directly related to the pH of the culture medium. Data are presented here for cultures grown in Cramer and Myer's medium at pH 3.0 and 6.8. DNA levels are ∼50% greater for Euglena at the higher pH value, confirming earlier reports.
Phosphate Incorporation by Euglena gracilis During pH‐dependent Photo‐inhibition1
Authors: COOK J. R. 
Published: May 2007

ABSTRACTInhibition of cell division in Euglena gracilis by visible light is pH‐dependent, being most severe in the pH range 3.5–5.0. Transfer of phototrophic cells from pH 6.8 to pH 4.2 can lead to cell death at modest light intensities (500 ft‐cd) and inhibition of division at lower intensities (300 ft‐cd). Inhibition is preceded by a large influx of phosphate, most of which remains in the cold PCA pool. It is suggested that light may act to reduce control over phosphate entry at these intermediate pH levels, and excess phosphate leads to inhibition of cell division or death.
Cell Cycle‐associated Changes of Guanylate Cyclase Activity in Synchronized Tetrahymena: a Possible Involvement of Calmodulin in its Regulation1
Authors: KUDO SHUZO , NAGAO SEIJI , KASAI REIKO , NOZAWA YOSHINORI 
Published: May 2007

ABSTRACTGuanylate cyclase activity decreased during the division phase of heat‐shock synchronized Tetrahymena pyriformis, strain GL. However, when Ca2+ was removed by EGTA to negate the effects of the Ca2+‐binding protein (calmodulin), which is required for the full activity of guanylate cyclase in this organism, no significant change in the enzymatic activity was observed throughout the cell cycle. On the other hand, the reduced guanylate cyclase activity at division phase was associated with a decreased level of calmodulin content. These results suggest that fluctuations in guanylate cyclase activity during the cell cycle would be dependent on the concentration of calmodulin.
Effect of Holothurin on Trypanosoma musculi infection in Three Strains of Mice1
Authors: SEN DILIP K. , LANKARANIFARD GHOLAMREZA , NARAIN NAND K. 
Published: May 2007

ABSTRACTThe effect of holothurin (a marine biotoxin) on the resistance of mice to Trypanosoma musculi was measured by studying changes in the parasite population in vivo. Swiss Webster (SW), Beige (BG), and Black (BL) mice treated with holothurin prior to and simultaneously with infection of trypanosomes had lower parasitemias than controls. Higher levels of parasitemia were observed in mice treated after infection with trypanosomes. The timing of administration of holothurin appeared to be an important factor in the observed effect. The minor variations in the parasitemia seemed to be related to the mouse strain.
Contamination Expérimentale In Vivo et In Vitro par Aggregata eberthi: Etude Ultrastructurale1
Authors: PORCHET ELIANE , RICHARD ALAIN , FERREIRA ELISABETH 
Published: May 2007

RESUMELe mode de contamination par Aggregata a étéétudié expérimentalement in vivo chez le Crabe, in vitro sur cultures cellulaires de Mollusques, puis suivi en microscopie électronique. Quelques heures après le repas infestant, les spores s'ouvrent dans l'estomac du Crabe et les sporozoïtes gagnent l'intestin moyen. Là ils traversent l'épithélium dans les espaces intercellulaires. La perforation de l'epaisse basale est liée à l'apparition d'une substance dense, de nature probablement enzymatique. Les lésions causées aux tissus du Crabe sont minimes. Les mérozoïtes sont capables de pénétrer en culture dans des cellules provenant de divers Mollusques; la membrane de la cellule‐hǒte n'est pas rompue. Un debut de développement est observé avec l'apparition d'un nucléole dans le noyau.
The Coccidian Caryospora bubonis in the Great Horned Owl (Bubo virginianus)1
Authors: STOCKDALE P. H. G. , CAWTHORN R. J. 
Published: May 2007

ABSTRACTThe life cycle of Caryospora bubonis was studied in the Great Horned Owl. Owls fed sporulated oocysts became patent on days 8–13, and peak oocyst production occurred between days 14 and 18. Owls fed infected mice became patent on days 8–10, and peak oocyst production occurred between days 9 and 13. The reduction in length of the life cycle in owls fed infected mice provides evidence that both indirect and direct life cycles can occur in this species and suggests that parallels exist in the lives of various isosporid, eimeriid, and other coccidia that may not have been sufficiently appreciated in the past.
The Challenge of Fish Coccidia1
Authors: DESSER SHERWIN S. 
Published: May 2007

ABSTRACTSpecies of Eimeria occurring in fishes show important differences, especially in their life cycles, with respect to what is known for those forms found in mammals or other hosts. In some cases, at least, some small invertebrate may play the role of vector or intermediate host. Present studies of fish coccidia may throw light on the possible evolution of certain aspects of host‐parasite interrelationships involving eimerian species in particular: for example, the earliest site (perhaps not the gut) of infection and even the “original” host group (perhaps invertebrates rather than vertebrates).
Ultrastructure of the Flagellar Apparatus and Attachment of Herpetomonas ampelophilae in the Gut and Malpighian Tubules of Drosophila melanogaster1
Authors: ROWTON EDGAR D. , LUSHBAUGH WILLIAM B. , McGHEE R. BARCLAY 
Published: May 2007

ABSTRACTElectron microscopy was used to examine the flagellar apparatus of Herpetomonas ampelophilae from the gut and malpighian tubules of Drosophila melanogaster. The flagellates attach to the microvilli either by weaving their flagella between the microvilli or by engulfing several microvilli with an external flagellar membrane. The first type predominated in the gut while the second type was limited to the malpighian tubules. Desmosomes were not involved in either type of attachment. A subpellicular collar with emerging microtubules was found to be adjacent to the desmosome of the flagellar pocket of herpetomonads in the gut.
An Ultrastructural Study of Eimeria iroquoina Molnar & Fernando, 1974 in Experimentally Infected Fathead Minnows (Pimephales promelas, Cyprinidae) 3. Merogony1
Authors: PATERSON W. BROCKLEY , DESSER SHERWIN S. 
Published: May 2007

ABSTRACTFathead minnows, Pimephales promelas, raised from eggs in the laboratory, were experimentally infected with oocysts of Eimeria iroquoina from either P. promelas or the common shiner, Notropis cornutus. Within intestinal epithelial cells, trophozoites thought to be derived from the sporozoites contained a prominent electron‐dense refractile body. Merozoites dedifferentiated into trophic forms by losing components of their apical complex and pellicle. The inner membrane components of the pellicle appeared discontinuous, and the micronemes became enclosed within vacuoles. Prior to merozoite formation, multinucleate meronts were limited by a single membrane. Golgi complexes were associated with the nuclei of this stage. Merozoites were formed by ectomerogony in one generation and by endomerogony in the final generation. In both forms of merogony the final nuclear division was coupled with the onset of differentiation of the merozoites and featured eccentric mitotic spindles associated with centrocones located within the nuclear envelope and with the precursors of the apical complex. A Golgi complex was closely associated with the nucleus and apical tip of the forming merozoite. Unlike other Eimeria species, the complete pellicle of the merozoites of the final asexual generation of E. iroquoina was formed within the cytoplasm of the meront, without association with the limiting membrane, thus, all pellicular components are synthesized de novo. The inner membranes of the pellicle initially appeared as longitudinal strips, each of which was associated with a pair of the 22–24 subpellicular microtubules. Mature meronts of the final asexual generation averaged 9 μm in diameter and produced 13–16 merozoites. With the exception of the internal completion of the pellicle of the final generation merozoites, the basic processes of merogony in fish Eimeria species are similar to those recorded in terrestrial hosts.
Ultrastructural Damage by Cadmium in a Marine Dinoflagellate, Prorocentrum micans1
Authors: SOYER MARIE‐ODILE , PREVOT PAUL 
Published: May 2007

ABSTRACTProrocentrum micans Ehrenberg, a free‐living marine dinoflagellate, was used to test the intracellular toxic action of cadmium. The cells were cultivated in Erdschreiber medium, with Cd concentrations of 10–100 ppb. Thin sections of treated cells, examined ultramicroscopically, exhibited vacuolations, increased numbers of lysosomes, and severe mitochondrial damage. The first two alterations are a general response to toxicity; the third is Cd specific. Although some chloroplasts were affected by Cd, they were not very sensitive to its action. The nuclear apparatus was not morphologically affected.
Transmission and Scanning Electron Microscopic Studies of the Micronemata of Trypanosoma gambiense1
Authors: ITO YOSHIHIRO , FURUYA MASATO , OKA MIKIO , OSAKI HUMIO , AIKAWA MASAMICHI 
Published: May 2007

ABSTRACTThe structure of micronemata arising from the surface of the bloodstream form of Trypanosoma gambiense was studied by electron microscopy. In order to produce micronemata, trypanosomes were incubated in either 1) phosphate buffered saline supplemented with glucose (PBSG), 2) immune mouse serum or 3) PBSG after passage through a DEAE‐cellulose column. Electron microscopic examination of the parasite revealed the presence of thread‐like micronemata arising from the anterior end and from the flagellar pocket regardless of the incubation conditions. Negative staining revealed a distinct peripheral fringe layer with nodular protrusions covering the entire surface of the micronema. The distribution and number of intramembrane particles (IMP) on the P and E faces of the micronema were similar to those of the flagellum of T. gambiense, indicating a close relationship between the membrane structure of the micronema and the flagellum. Micronemata became fragmented and adhered to each other after incubation of the parasite in the media for 12 h. Since micronemata tend to have the characteristics of adhesiveness and fragmentation, fragments of these structures might adhere to various host organs. Dispersal of potential antigenic material might be responsible, in part, for the induction of the host immune response.
In Vivo Incorporation of a Polyunsaturated Fatty Acid into the sn‐C‐1 and sn‐C‐2 Positions of Tetrahymena Glycerophospholipids1
Authors: SCHICK BARBARA P. , CONNER ROBERT L. 
Published: May 2007

ABSTRACTThe glycerophospholipids of the protozoon Tetrahymena pyriformis W are unique in that the polyunsaturated fatty acid γ‐linolenate (18:3Δ6,9,12) is a major component of both the sn‐C‐1 and sn‐C‐2 positions. Tetrahymena were incubated with [1‐14C]γ‐linolenate. The positional distribution of the radiolabeled fatty acid in the three major glycerophospholipids was determined. [1‐14C]γ‐linolenate was found at both carbons of the three lipids, in general agreement with the mass distribution of γ‐linolenate, except for markedly greater labeling at the sn‐C‐2 position of phosphatidylcholine. We hypothesize that an acyltransferase exists in Tetrahymena that can esterify γ‐linolenate at both carbons during glycerophospholipid biosynthesis.
Motion of the Longitudinal Flagellum in Ceratium tripos (Dinoflagellida): A Retractile Flagellar Motion1
Authors: MARUYAMA TADASHI 
Published: May 2007

ABSTRACTThe longitudinal flagellum of Ceratium tripos moves in two dissimilar ways: undulation and retraction. The undulatory wave is planar and has a wavelength of 74.3 ± 9.6 μm and an amplitude of 14.2 ± 2.3 μm in sea water. The beat frequency is 30 Hz at 20°C, pH 8.0. The retractile motion is unique to Ceratium and is triggered by mechanical stimulation on the cell body, especially at the tip of the apical horn. When it retracts, the longitudinal flagellum folds every 4–5 μm along the flagellum. Cinematographic study showed that the flagellum folded from tip to base and was finally installed into the sulcus, a groove on the ventral side of the cell. This motion is completed in sea water within 28 msec. The retracted flagellum then re‐extends and restores the undulation within a few seconds. The flagellum unfolds in the proximal portion first, then the distal, and finally the middle portion. Fixation always triggers the retraction. Scanning electron microscopy showed that the flagellum is folded and secondarily twisted in a helix. A new fiber in addition to the flagellar axoneme was found in the retracted flagellum by phase microscopy. This fiber (R‐fiber) seems to contract during the retraction to fold the flagellum.
Diffusion Coefficient of Paramecium as a Function of Temperature1
Authors: KAWAKUBO T. , TSUCHIYA Y. 
Published: May 2007

ABSTRACTThe motion of Paramecium caudatum has been investigated at various temperatures by measuring the transient behavior of spatial distribution in the diffusion process of organisms that, by electric stimulus, are initially gathered at a single place in the glass culture cell. The spatial distribution through the course of diffusion has a nearly Gaussian profile. Dispersion was obtained at 1 sec intervals and increased linearly with time. The time dependence of the dispersion gave a diffusion coefficient for the random motion of the organisms. The results show that the diffusion coefficient has a maximum at the temperature at which the paramecia were cultivated.
Phagocytosis of Trypanosoma cruzi by Human Polymorphonuclear Leukocytes1
Authors: RIMOLDI MARÍA TERESA , OLABUENAGA SUSANA E. , DE BRACCO MARÍA M. DE E. 
Published: May 2007

ABSTRACTPhagocytosis of culture forms of Trypanosoma cruzi was assayed by a radioisotopic method. Purified polymorphonuclear leukocytes (PMN) were mixed with 3H‐uridine‐labeled T. cruzi epimastigotes in the presence or absence of anti‐T. cruzi antibodies. The reaction was stopped by adding N‐ethyl‐maleimide, and noningested parasites were lysed by complement. The percentage of radioactivity incorporated into the PMN pellet was recorded. The phagocytosis reaction was rapid, yielding maximum incorporation at 30 min at which point the radioactivity associated with the PMN cells decreased through release of the isotope to the supernatant. The degree of incorporation of radio‐labeled parasites was a function of the effector/target cell ratio and the antibody concentration. The method is suitable for the quantitative determination of phagocytosis of T. cruzi by normal PMN.
New Species of Lankesteria (Apicomplexa, Eugregarinida) from Ascidians on the Central California Coast1
Authors: LEVINE NORMAN D. 
Published: May 2007

ABSTRACTThe following species of the gregarine genus Lankesteria were found in a study of ascidians from Monterey Bay, on the central California coast of the Pacific Ocean: L. abbotti n. sp. in Clavelina huntsmani, L. aplidii n. sp. in Aplidium solidum, L. ascidiae in Ciona intestinalis, L. diaphanis n. sp. in Archidistoma diaphanes, L. euherdmaniae n. sp. in Euherdmania claviformis, L. montereyensis n. sp. in Archidistoma molle, L. pescaderoensis n. sp. in Ritterella rubra, L. pittendrighi n. sp. in Ascidia ceratodes, L. psammii n. sp. in Archidistoma psammion, L. ritterellae n. sp. in Ritterella pulchra, L. ritterii n. sp. in Archidistoma ritteri, L. synoici n. sp. in Synoicum parfustis, and Lankesteria sp. in Botrylloides sp. No gregarines were seen in the following ascidians: Aplidium californicum, A. propinquum, Botryllus tuberatus, Diplosoma macdonaldi, Perophora annectens, and Polyclinum planum.