bluuebunny/crossref_metadata_2025 huggingface dataset:
Variation In Surface Proteins In Tetrahymena*
Authors: WILLIAMS N. E. , VAN BELL C. , NEWLON M.
Published: May 2007

SYNOPSIS. Surface proteins of Tetrahymena were identified by lactoperoxidase iodination, and comparisons were made between a number of strains and species within the genus. an adequate procedure for strain comparisons was found to be solubilization of whole cells following iodination, separation of total cell protein using polyacrylamide gel electrophoresis, and identification of surface proteins by autoradiography of dried gels. the results obtained in the present study show the existence of both interspecific and intraspecific variation in surface proteins of Tetrahymena, but the differences tend to be small within species and large between species. the relation of these cell surface fingerprints to the present taxonomic designations within the genus is discussed. Questions are raised about the functional significance of these surface proteins.
Eimeria Ahsata Honess From Domestic Sheep (Ovis Aries) In Italy
Authors: BATTELLI GIORGIO , POGLAYEN GIOVANNI
Published: May 2007

Examination for coccidia of 20 domestic sheep (Ovis aries) from a farm in Rome Province revealed the following 5 species:Eimeria ahsataHoness,E. intricateSpiegl,E. ovinaLevine & Ivens,E. ovinoidalisMcDougald, andE. parvaKotlàn, Mócsy & Vajda. of these species, onlyE. ahsatawas not previously reported in Italy. For this reason, a description of this coccidium and a statistical analysis of size differences betweenE. ahsataandE. ovinaare given.
Effects of Feeding Schedules On Diurnal Periodicity of Leucocytozoon Smithi Gametocytes In the Peripheral Blood of Domestic Turkeys*
Authors: NOBLET GAYLE PITTMAN , GORE THOMAS C. , NOBLET RAYMOND
Published: May 2007

Eighteen domestic turkeys naturally infected with Leucocytozoon smithi Laveran & Lucet were maintained on restricted feeding schedules under conditions of either continuous light or natural light (light 13 h:darkness 11 h) photoperiods. Peripheral gametocyte numbers of L. smithi in all turkeys were determined every 2 h over a 36‐h period. Peripheral gametocyte numbers of turkeys maintained under continuous light and restricted to either a 10‐h feeding period (9:30 p.m. to 7:30 a.m.) once a day or a 2‐h feeding period twice a day (7:30 a.m. to 9:30 a.m. and 7:30 p.m. to 9:30 p.m.) increased at or near the time of feed availability. Under natural photoperiod, gametocyte periodicity was not affected by restricting feed availability to the dark phase of the light‐dark cycle. Mean parasite numbers were highest during the light phase when feed was not available, and lowest during the dark period when feed was accessible.
Increase of Growth Rate and Phagocytic Activity of Tetrahymena Induced By Pseudomonas Lectins
Authors: GILBOA‐GARBER NECHAMA , SHARABI YEDIDA
Published: May 2007

Galactosephilic and mannosephilic lectins from Pseudomonas aeruginosa interact with Tetrahymena pyriformis GL. Specific adsorption of these lectins onto the Tetrahymena can be shown by inhibition of hemagglutination and by peroxidase binding to the cells mediated by the mannosephilic lectins. Interaction with the lectins does not agglutinate the protozoa even after immobilization by Na fluoride, formaldehyde, and glutaraldehyde or after papain treatment. However, inclusion of the lectins in the growth medium increases the growth rate of Tetrahymena and their presence in the medium supplied to starved ciliates increases phagocytosis of Chinese ink and vacuolization.
Eimeriidae of the Herbivorous Mole‐Rat, Spalax ehrenbergi Nehring
Authors: SAYIN FAHRI
Published: May 2007

SYNOPSIS. A survey of 41 herbivorous mole‐rats, Spalax ehrenbergi Nehring, in Urfa, Adiyaman, and Maras provinces of Turkey revealed 7 new species of Eimeria in addition to previously described Eimeriidae. The shape, average dimensions (in μm) of their oocysts, and the numbers of hosts from which the new species were isolated were as follows: Eimeria urfensis sp. n., ellipsoidal (33 × 21), from 8 hosts; Eimeria adiyamanensis sp. n., ovoid to ellipsoidal (33 × 18), from 6 hosts; Eimeria haranica sp. n., elongate ovoid (37 × 20), from 22 rats; Eimeria marasensis sp. n., ellipsoidal (36 × 18), from 2 rats; Eimeria oytuni sp. n., pear‐shaped (24 × 17), from 2 hosts; Eimeria celebii sp. n., ellipsoidal (16 × 9), from 1 rat; and Eimeria torosicum sp. n., spherical to subspherical (11 × 10), from 2 animals.
Primary Lysosomes of the Ciliate Pseudomicrothorax dubius: Cytochemical Identification and Role in Phagocytosis*
Authors: PECK ROBERT K. , HAUSMANN KLAUS
Published: May 2007

SYNOPSIS. Filamentous cyanobacteria are ingested through the cytopharynx of the ciliate Pseudomicrothorax dubius. The cytopharynx is a complex of microtubules and microfilaments located in a highly vesiculated cytoplasm, the phagoplasm. Two types of membrane‐bounded phagoplasmic vesicles can be distinguished by their differences in size, fine structure, and acid phosphatase (AcPase) content. One type has a homogeneous, electron‐dense interior which is AcPase‐positive. These vesicles are present in fed cells and in unfed cells devoid of food vacuoles, and thus appear to be primary lysosomes. During phagocytosis, exocytosis within the cytopharynx of the primary lysosomes results in the elaboration of a food vacuole. The vacuole grows by incorporation of lysosomal membrane; lysosomal hydrolases are liberated into the vacuole. Within less than 1 second of AcPase's entry into the food vacuole, it is detectable within the cyanobacterial cytoplasm, and within 5 seconds, destruction of the cyanobacterial filament is observed. It is hypothesized that the rapidity of hydrolase penetration of the cyanobacterial cell wall is the result of the action of molecules analogous to the “killing agents” of neutrophil leukocytes, which rapidly render bacterial envelopes permeable. AcPase, and presumably other hydrolases, are present in the cyanobacterial filament when filament destruction occurs; they thus appear implicated in this process. Hydrolases may activate an autodestruction mechanism in the cyanobacterium. Firm adherence of the food vacuole membrane to the cyanobacterial filament is demonstrated, and its role in phagocytosis is discussed.
Isozymic Characterization of Three Mating Groups of the Tetrahymena pyriformis complex*
Authors: NANNEY D. L. , COOPER L. E. , SIMON E. M. , WHITT G. S.
Published: May 2007

SYNOPSIS. Strains of 3 unnamed mating groups of the Tetrahymena pyriformis complex have been subjected to starch gel electrophoresis followed by staining the gels for the enzymes isocitrate dehydrogenase (NADP), tyrosine aminotransferase, and tetrazolium oxidase (superoxide dismutase). With respect to the electrophoretic mobilities of these enzyme systems, the mating groups referred to here as 5, 13 and 14 are very similar to Tetrahymena americanis (syngen 2), the most common North American species of the complex.

Cultures in our collection labeled Tetrahymena cosmopolitans (formerly syngen 4) are either amicronucleate, with unique isozyme patterns, or micronucleate cells which mate with and have isozyme patterns similar to Tetrahymena canadensis (syngen 7). Immature progeny have been derived from crosses between the latter strains and T. canadensis recently collected in Colorado. The amicronucleate strains are now placed in the Tetrahymena sp. category, and we conclude that strains identifiable as T. cosmopolitanis are no longer available.

The reliability of isozymes as characters in ciliate taxonomy was evaluated by comparing the present results for 3 enzymes in 15 groups of strains (syngens and phenosets) that had been compared in an earlier study. These enzyme systems gave correlation coefficients (r) of 0.75 or higher in the separate studies, and can be considered useful diagnostic traits. Other enzymes that were present at threshold levels of detectability or varied highly in concentration from species to species are too unreliable to be of diagnostic value. Some of the strains in the complex are so evolutionarily divergent at the molecular level that we have difficulty finding growth and electrophoretic conditions under which orthologous enzyme activities can be detected simultaneously for all the strains being compared.
Attachment of Entamoeba histolytica to Glass in a Defined Maintenance Medium: Specific Requirement for Cysteine and Ascorbic Acid*
Authors: GILLIN FRANCES D. , DIAMOND LOUIS S.
Published: May 2007

SYNOPSIS. Cysteine and ascorbic acid were previously shown to be required by Entamoeba histolytica trophozoites for attachment to glass, elongation, and ameboid movement as well as for short‐term (12–24 h) survival in a balanced salt solution containing bovine serum albumin and a vitamin solution (Maintenance Medium 1). If the only function of cysteine and ascorbate was to decrease the redox potential, other reducing agents should be effective. However, the requirement for cysteine in the presence of ascorbic acid was highly specific. Equally effective were D‐ and L‐cysteine; however, of many other compounds tested, only thioglycolic acid, ascorbic acid, or L‐cystine (in decreasing order) were somewhat active. Under N2 atmosphere, cysteine and ascorbic acid were still required, although their concentrations could be halved. The ability to attach in the maintenance medium was irreversibly lost after only 5 min of cysteine‐ascorbic acid deprivation; however, there was no decrease in viability when the amebae were transferred to growth medium within 30 min. Cysteine thiol groups in the medium were oxidized rapidly regardless of the concentration of ascorbic acid or the presence of amebae; however, ascorbic acid prolonged attachment of amebae.
Effect of Chlorpromazine on Active Transport of Amino Acids in Tetrahymena*
Authors: BLUM J. J.
Published: May 2007

SYNOPSIS. Low concentrations of chlorpromazine (∼0.01 mM) inhibit growth and nucleic acid synthesis in the ciliate Tetrahymena pyriformis. Brief exposure of the cells to, e.g. 0.018 mM chlorpromazine, had very little effect on 14CO2 production or on label incorporation into glycogen from [1‐14C]glucetate, [6–14C]glucose, or [1‐14C]leucine, but 17‐h exposure of stationary phase cultures to this drug caused marked alterations in metabolism, including an almost complete loss of ability to decarboxylate L‐[1‐14C]leucine and L‐[1‐14C]tyrosine. It was shown that loss of ability to decarboxylate these amino acids results from loss of ability to transport them.
Rhodomonas lacustris(Pascher & Ruttner) Javornicky (Cryptomonadida): Ultrastructure of the Vegetative Cell
Authors: KLAVENESS DAG
Published: May 2007

The ultrastructure ofRhodomonas lacustriswas examined using scanning and transmission electron microscopy, and the pigments were scanned in vivo by the opal plate technique. The periplast is composed of hexagonal plates, with trichocysts at the corners. This cryptomonad lacks a gullet but has a deep ventral furrow, in which more than 20 large ejectosomes are located. The chloroplast has mainly three thylakoids per lamella, and it is structurally reminiscent of that of certain haptophycean flagellates. The pigments appear to be as usual within the photosynthetic cryptomonads, with phycoerythrin type PE I (phycocyanin was not detected). Other cellular inclusions (e.g., lysosome‐like vesicles and the contractile vacuolar complex) are also discussed.
The Cultivation of Blastocrithidia triatomae Cerisola et al., 19711
Authors: PENG PHILLY LIN‐MOO , WALLACE F. G.
Published: May 2007

Blastocrithidia triatomae, a species very resistant to cultivation in conventional media, was successfully grown in association with cultured lepidopteran cells. The cultured flagellates were identical to those in the insect host, including the presence of characteristic cysts on the flagellum. Growth rate was better for cultures in the Heliothis zea medium than in IPL‐45 medium or modified McConnell's medium.
Ultrastructural Differences Between Species of Trypanosomatids With and Without Endosymbionts1
Authors: FREYMULLER EDNA , CAMARGO E. PLESSMANN
Published: May 2007

Species of trypanosomatids without endosymbionts (Leptomonas seymouri, L. collosoma, L. samueli, Crithidia fasciculata, C. luciliae, C. acanthocephali, Herpetomonas megaseliae, H. mariadeanei, H. samuelpessoai, H. muscarum muscarum, Trypanosoma cruzi) and species of trypanosomatids with endosymbionts (Crithidia deanei, C. oncopelti, Blastocrithidia culicis) were comparatively studied by means of electron microscopy. Artificially aposymbiotic strains derived from species with symbiont were also included in the survey. Species with symbiont were found to differ in some ultrastructural aspects from the group of species without symbiont. Paraxial rods of flagella or intraflagellar structure were found exclusively in species without symbiont. Peripheral branching of mitochondria, accompanied by absence of subpellicular microtubules in sites where the mitochondrial branches are appressed to the cell membrane, were found exclusively in species with symbiont. Networks of kinetoplast DNA fibrils were found to be larger and looser in species with symbiont. Symbiont‐free strains of species with symbiont retained the same morphological characteristics of their parental species.
Structure and Elemental Composition of the Cyst Wall of Echinosphaerium nucleofilum Barrett (Heliozoea, Actinophryida)1
Authors: PATTERSON DAVID J. , THOMPSON DUDLEY W.
Published: May 2007

The structure of the cyst wall of the heliozoon Echinosphaerium nucleofilum has been investigated using light microscopy, scanning and transmission electron microscopy, and X‐ray microanalysis. The cyst wall is a composite structure of seven or eight layers. These are: an enveloping gelatinous layer; a layer of siliceous spheroidal bodies; an electron‐dense supporting membrane; a broad electron‐lucent zone; an electron‐dense layer; a layer of helicoidally packed material; and one or two layers with a granular appearance lying next to the plasma membrane of the encysted organism. The structure of the cyst wall closely resembles that of Actinophrys sol, confirming the close relationship of these actinophryid heliozoa while emphasizing their distinctiveness from other amoeboid protista.
Cell Surface Carbohydrates in Tritrichomonas foetus1
Authors: BENCHIMOL MARLENE , PEREIRA MIERCIO E. A. , ELIAS CEZAR A. , DE SOUZA WANDERLEY
Published: May 2007

The cell surface of Tritrichomonas foetus was characterized by using 18 highly purified lectins with specificities for N‐acetyl glucosamine, N‐acetyl galactosamine, galactose, mannose, and sialic acid. The specificity of the lectin‐induced cell agglutination was verified by inhibition of the agglutination with the specific sugars. By using cytochemical techniques associated with electron microscopy, carbohydrates were detected on the cell surface of T. foetus. The following techniques were used: periodic acid‐thiosemicarbazide‐silver proteinate, concanavalin A‐horseradish peroxidase, and ruthenium red. Anionic sites were detected on the cell surface of the protozoan at pH's 1.8 and 7.2 with the use of colloidal iron hydroxide and cationized ferritin particles, respectively. The binding of colloidal iron particles, as well as the agglutination induced by the lectin from Limulus polyphemus, indicated the presence of sialic acid on the cell surface of T. foetus.
Formation of 2‐Aminobutanoic Acid from Threonine and Methionine by Mixed Rumen Ciliate Protozoa
Authors: ONODERA RYOJI , USHIJIMA TAKAYUKI
Published: May 2007

Precursors of 2‐aminobutanoic acid (2‐ABA), found in the incubation medium of mixed rumen ciliate protozoa, were examined with washed or starved bacteria‐free ciliates. Threonine and methionine strongly stimulated the formation of 2‐ABA. Formation of 2‐ABA by direct conversion of threonine and dethiomethylation of methionine was confirmed by radiotracer experiments with [U‐14C]L‐threonine and [carboxyl‐14C] and [methyl‐14C]L‐methionine.
Trypanosoma cruzi: Biological Characterization of 19 Clones Derived from Two Chronic Chagasic Patients. I. Growth Kinetics in Liquid Medium1
Authors: ENGEL JUAN C. , DVORAK JAMES A. , SEGURA ELSA L. , CRANE MARK ST. J.
Published: May 2007

Nineteen clones of Trypanosoma cruzi were obtained as single‐cell isolates from Triatoma infestans. Ten of the clones were isolates from a patient with chronic Chagas' disease; nine clones were isolates from a dog infected with T. cruzi strain CA‐I isolated originally from a chronic chagasic patient. The growth kinetics and peak modal Coulter volume of these clones were characterized. Significant inter‐ and intra‐group differences between growth rates and peak modal volumes were found. These data indicate that subpopulations and, consequently, genetic heterogeneity of T. cruzi exist in chronic chagasic patients. All of the clones infected vertebrate cells in vitro.
Biochemical and Structural Analyses of Microtubules in the Pellicular Membrane of Leishmania tropica1
Authors: BORDIER CLEMENT , GARAVITO R. MICHAEL , ARMBRUSTER BARBARA
Published: May 2007

The structure of the major protein of the pellicular membrane of Leishmania tropica was investigated. This protein is composed of two polypeptides, of ca. 50,000 d molecular weight, that were found to cross‐react immunologically with the α and β subunits of pig brain tubulin. The polypeptides and pig brain tubulin subunits were partially digested with S. aureus V8 protease, and the peptides obtained analysed by SDS‐polyacrylamide gel electrophoresis. A comparison of the patterns showed that the β subunits of Leishmania and pig tubulin have very similar primary structures, while the α subunits have evolved divergently. These experiments demonstrate that the major polypeptides found in the pellicular membrane of L. tropica are α and β subunits of tubulin. Immuno‐electron microscopy indicates that the tubulin is located in the microtubules associated with the pellicular membrane of Leishmania. Arrays of microtubules were prepared by nonionic detergent treatment of the cells and observed by electron microscopy after negative staining. Optical diffraction reveals a 5 nm spacing between protofilaments in the microtubule and a 4 nm axial periodicity corresponding to the tubulin subunits. The pitch of the shallow left‐hand three‐start helix is 12°. A distance of 47 nm separates each microtubule from the next. These data show that the dimensions and supramolecular organization of the tubulin subunits in the microtubules are identical in the pellicular membrane of L. tropica and in mammalian brain.
Unicapsula seriolae n. sp. (Myxosporea, Multivalvulida) from Australian Yellowtail Kingfish Seriola lalandi1
Authors: LESTER R. J. G.
Published: May 2007

Unicapsula seriolae n. sp. forms long plasmodia within the striated muscle fibers of Seriola lalandi off eastern Australia. Its spores are composed of three valves, only one of which contains a developed polar capsule. Within the capsule, the filament makes 2 1/2–3 turns, and this criterion can be used to separate U. seriolae from the two other members of the genus. The flesh of infected fish disintegrates during slow cooking.
Distribution of Members of the Crypthecodinium cohnii (Dinophyceae) Species Complex1
Authors: BEAM CARL A. , HIMES MARION
Published: May 2007

Crypthecodinium cohnii, a small marine heterotrophic homothallic dinoflagellate, has diversified into a complex of morphologically very similar breeding groups (biological species or sibling species), some of which have become widely dispersed. Membership of two clones in the same sibling species is shown by their sexual compatibility as determined by genetic complementation in zygotes formed from motility mutants derived from the two stocks. Membership in different sibling species may be inferrec when motility mutants of one strain do not complement those of another. Fifty‐six clones representing seaweed enrichments from *** geographic sites have been found to belong to 28 sibling species; 35 clones are members of seven wide‐ranging biological species, and 21 are single representatives of 21 other breeding groups within the ranges of the others. Of 174 clonal isolates in our possession, 168 conform in size and shape to C. cohnii. Six others which have smaller cells and only one‐fifth the standard DNA and chromosome number belong, we believe, to another species. The C. cohnii complex provides a unique opportunity for the study of evolutionary divergence and geographical dispersion of a dinoflagellate.
Development of Plasmodium chabaudi in Mouse Red Blood Cells: Structural Properties of the Host and Parasite Membranes1
Authors: WUNDERLICH FRANK , STÜBIG HELLA , KÖNIGK EBERHARD
Published: May 2007

The structure of both the host and parasite membranes during stages in the asexual development of Plasmodium chabaudi in mouse red blood cells is examined by transmission electron microscopy of thin sections and freeze‐fracture preparations. The erythrocyte's plasma membrane, the membrane of the parasitophorous vacuole, and the plasma membrane of the parasite exhibit different structural properties in terms of membrane width and the frequency and diameter of the typical intramembrane‐particles (IMP) populating the membrane's fracture faces. The difference between the parasitophorous vacuolar membrane and host cell's plasma membrane is remarkable because the vacuolar membrane is formed from an invagination of the erythrocyte's plasma membrane. The vacuolar membrane has significantly reduced frequencies and diameters of IMP's on both faces and reveals a marked temperature response manifesting itself as large IMP‐devoid domains emerging on both faces on chilling to 4°C. In contrast, cooling induces only some very small IMP‐devoid patches on both faces of the host plasma membrane. Neither of these membranes changes significantly as parasite development progresses. In contrast, the parasite's plasma membrane shows local alterations during its development, forming compaction domains with the nuclear envelope in ca. 30% of the ring‐stages and trophozoites. These compaction domains disappear in late uninuclear trophozoites and schizonts. Furthermore, the plasma membrane of the host cell, the vacuolar membrane, and the parasite's plasma membrane do not respond to externally applied Ca2+, and their temperature‐response remains unaltered during the infection cycle. Thus, modification of these three membranes as a consequence of invasion and development of the parasites, as recently found in the primate malaria caused by P. knowlesi, can be detected neither directly nor indirectly via temperature‐ and/or Ca2+‐response in the rodent malaria caused by P. chabaudi.
In Vivo and In Vitro Activity by Diverse Chelators against Trypanosoma brucei brucei1
Authors: SHAPIRO ANNA , NATHAN H. C. , HUTNER S. H. , GAROFALO JOANNE , McLAUGHLIN SUSAN DITTUS , RESCIGNO DIANE , BACCHI C. J.
Published: May 2007

A system of prescreens and screen has been developed to select chelators as potential drugs against Trypanosoma brucei brucei EATRO 110. The chelators tested were nearly all commercially available, low molecular, and having moderate to high affinity for Fe(III). We prescreened 70 compounds showing heme‐sparing or inhibitory activity in a Crithidia fasciculata growth system having excess Fe and minimal hemin. Of these, 45 were highly trypanocidal for suspensions of bloodstream T. b. brucei; criteria of activity here were immobilization, lysis, and loss of infectivity. Eighteen of the chelators highly active in the suspension prescreen were tried in T. b. brucei‐infected mice. Thirteen of these chelators were curative in mice with 24‐h infections, that is, they allowed survival >30 days beyond the untreated controls. 3,4‐Dihydroxycinnamic acid (caffeic acid). 2,9‐dimethyl‐1, 10 phenanthroline (neocuproine), and 2‐pyridinecarboxaldehyde‐2‐pyridyl‐hydrazone cured five out of five mice after an i.v. dose of 100 mg/kg. Salicylaldehyde thiosemicarbazone cured five out of five mice at an i.p. dose of 500 mg/kg. Lesser activity was shown by several other chelators.
Characterization of the Proteins of Naegleria fowleri: Relationships between Subunit Size and Charge1
Authors: WOODWORTH T. W. , KEEFE W. E. , BRADLEY S. G.
Published: May 2007

Proteins of whole cell extracts of Naegleria fowleri, precipitated with acetone, have been resolved by two‐dimensional polyacrylamide gel electrophoresis. Autoradiograms of the [35S]‐methionine‐labeled polypeptides were scanned and analyzed by a computer‐assisted program in order to determine whether there were correlations between selected attributes of proteins (e.g., subunit size and charge). The majority of the polypeptides had molecular sizes within the range of 20–60 kilodaltons. The mean amount of polypeptide was less for those with molecular sizes between 20 and 45 kilodaltons than for those larger than 45 kilodaltons. The mean amount of polypeptide was greater in the isoelectric focusing range of pH 5–6 than in the range of pH 6–7. Polypeptides in the size range of 20–40 kilodaltons had a median isoelectric point of 6.1, whereas polypeptides in the size range of 40–80 kilodaltons had a median pI of 5.6. Our data indicated that molecular size and charge were not entirely independent variables, and that the composition of a polypeptide might have an important influence on its steady state level in N. fowleri.
Adhesion and Interiorization of Trypanosoma cruzi in Mammalian Cells1
Authors: ANDREWS NORMA W. , COLLI WALTER
Published: May 2007

A quantitative method for experimentally separating the adhesion and interiorization phases of the interaction of Trypanosoma cruzi with mammalian cells was developed. Incubation of confluent monolayers of mammalian cells with epimastigotes or trypomastigotes at 4°C allowed the evaluation of the number of adhered parasites that do not become interiorized at this temperature. Quantification of interiorized parasites at 34°C was achieved by employing hypotonic lysis to eliminate the extracellularly adhered trypomastigotes. Both adhesion and interiorization were found to be proportional to the time of exposure of cells to parasites and to the multiplicity of infection. These phenomena occur normally for trypomastigotes in the absence of serum with LLC‐MK2 cells, HeLa cells, and 3T3 fibroblasts. Moreover, it was possible to obtain trypomastigotes that presented the same infectivity to LLC‐MK2 cells as did parasites obtained in the presence of 2% fetal calf serum after 10 serial passages in a medium devoid of serum. Inhibition of adhesion (of epimastigotes and trypomastigotes) and of interiorization (of trypomastigotes) was obtained with inactivated normal serum from several sources, a saturation effect being observed at a final concentration of 20%. Bovine serum albumin, at the concentrations present in the sera, had no inhibitory effect. Trypomastigotes that have been pre‐incubated with 40% FCS (45 min at 4°C) showed decreased adhesion and interiorization indices, effects that can be reversed by trypsinization of the parasites prior to exposure of the cells. A progressive internalization of previously attached trypomastigotes was observed on raising the temperature from 4°C to 34°C; no spontaneous detachment of parasites was detected up to 120 min. Approximately 75% of the adhered parasites were found inside the cells after 45 min at 34°C. The presence of normal inactivated calf serum during incubation at 34°C resulted in a certain degree of detachment and in a lower interiorization index.
Development of Caryospora bigenetica n. sp. (Apicomplexa, Eimeriidae) in Rattlesnakes and Laboratory Mice1
Authors: WACHA RICHARD S. , CHRISTIANSEN JAMES L.
Published: May 2007

During a survey of the coccidian parasites of reptiles from Iowa, three specimens of Crotalus horridus L., the Timber Rattlesnake, and one of Sistrurus catenatus (Rafinesque), the Massasauga Rattlesnake, were found to be passing oocysts of a Caryospora, here described as C. bigenetica n. sp. Since these snakes (family Crotalidae) are known to subsist mainly on small mammals, oocysts from one of the Timber Rattlesnakes were fed to laboratory white mice (Mus musculus L.) to determine if mammals might be involved as alternate hosts in the life cycle. At necropsy, tissues of the tongue and dermis of the mice revealed a sequence of stages which included mature male and female gamonts, fully sporulated sporocysts, “excysted” sporozoites, and “resting” sporozoites that lay individually in solitary, cyst‐like host cells termed “caryocysts.” A coccidia‐free Massasauga that was fed an infected mouse, at a time when caryocysts in the mouse would have been present, later passed oocysts similar to those of the original inoculum. These results, along with the discovery of endogenous stages (asexual and sexual) in the intestine of the Timber Rattlesnake and the experimentally infected Massasauga, suggest that this parasite has a heteroxenous life cycle pattern, with sexual stages occurring both in the ophidian and the mammalian hosts.
Ornithine Decarboxylase in Trypanosoma brucei brucei: Evidence for Selective Toxicity of Difluoromethylornithine1
Authors: GAROFALO JOANNE , BACCHHI C. J. , McLAUGHLIN SUSAN DITTUS , MOCKENHAUPT DIANE , TRUEBA GENEROSA , HUTNER S. H.
Published: May 2007

ABSTRACT. Activity of ornithine decarboxylase, the major rate limiting enzyme of polyamine biosynthesis, was determined in bloodstream trypomastigotes of Trypanosoma brucei brucei. The enzyme required pyridoxal‐5′‐phosphate, dithiothreitol and EDTA for optimal activity. Several properties of the enzyme were investigated and compared to the mammalian enzyme. Most notably, the parasite enzyme was >60‐fold more sensitive to the inhibitor DL‐α‐difluoromethylornithine than its mammalian counterpart, thus making it an attractive target for chemotherapy.
Substrate Contact, Mucus, and Eugregregarine Gliding1
Authors: MACKENZIE CAROLE , WALKER MURIEL H.
Published: May 2007

ABSTRACT. Experiments have been carried out on Gregarina garnhami to examine some of the factors that may be significant in gliding. Suspension of gregannes in Ficoll showed that substrate contact is essential. Reflection interference microscopy shows that there are fluctuating surface/substrate contacts, but it is not necessary for the whole of the undersurface of the cell to be in close contact with the substrate. Gliding is always accompanied by the formation of a mucus trail. The effects of the drugs amphetamine and ephedrine on mucus trail formation and gliding have been examined. Lateral undulations of the epicyte folds have previously been implicated in grcgarinc gliding, but G. garnhami does not exhibit lateral undulations of the epicyte folds as it moves. The folds are predominantly straight with indications of varicosities or swellings along the length of the folds. These observations are discussed in relation to gliding movement.
Suitability of Selected Marine Algae for Growing the Marine Heterotrich CiliateFabrea salina1
Authors: REPAK ARTHUR J.
Published: May 2007

ABSTRACT.Forty‐five axenically grown algal (sensu lato) species representing six divisions—that is. 13 Chlorophyceae, 14 Chrysophycophyta, five Dinophycophyta, seven Cryptophycophyta, two Rhodophycophyta, and four Cyanochloronta—were aseplicaily presented separately as potential food sources to the marine helerotrich ciliateFabrea salinaunder standardized algal number, medium, lighting, and temperature. The algae can be placed into three groups based on their effect on the intrinsic growth rate of the ciliate. Nutritious:Rhodomonas lens, cryptomonad LIS1,Dunaliella parva, Prasinodadus marinus, Chroomonas salina, D. tertiolecta, Chaeloceros galvestonensis, D. primolecta, Phaeodactylum tricornutum, D. salina, Isochrysis galbana, Cylindrothecaclosterium, cryptomonad strains M2, WH2& FSA,Chroomonas sp., P. lubricus, and Peridinium trochoideum.Maintamers: Cyanobacterium strain Tigriopus blue green,P. triquetum.Monochrysis lutheri, Exuviella gracilis, Platymonas tetrathele. Cyclotella caspa, Crypthecodinium cohnii, Prasinocladus C5strain,D. viridis, Nannochloris occulata, Tetraselmis gracilis, Anacystis marinum, Rhodosorus marinum, andThalassiosira pseudonana.Nonnutritious:Stichococcus immobilis, Hymenomonassp. strain 150,Syracosphaerasp. strain 181, Tetraselmis verrucosa, Thalassiosira fluviatilis, Microcoleus chthonoplastes, Synechococcus sp.,Pavlova gyrans, Prymnesium parvum, Coccolithus huxleyi, Olisthodiscus luteus, Amphidinium carterii, and Porphyridium aerugineum.There was no apparent relationship between a given taxon and the nutritional value of the group, with the possible exception of the Cryptophycophyta.
Fine Structure and Cytochemistry of the Nucleus and the Kinetoplast of Epimastigotes of Trypanosoma cruzi1
Authors: ESPONDA P. , SOUTO‐PADRÓN T. , SOUZA WANDERLEY DE
Published: May 2007

ABSTRACT. Ultrastructural cytochemical techniques were used to analyze the nucleus and the kinetoplast of epimastigotes of Trypanosoma cruzi. With the use of ethanolic phosphotungstic acid, which detects basic proteins, reaction product was seen in the chromatin and at the periphery of the kinetoplast. Thallium alcoholate, which interacts with DNA, stained strongly the whole kinetoplast and the chromatin. With the use of a silver impregnation method that detects acidic nucleolar proteins, silver granules were seen preferentially located in the central region of the nucleolus. With the EDTA method, which reveals the presence of ribonucleoproteins, staining was observed in the nuclear pores. Also 6–8 nm fibrils, 25 nm and 40 nm granules, which correspond to the perichromatin fibers, interchromatin granules and the perichromatin granules, respectively, were identified in the nucleus. The EDTA method also revealed the presence of 40 nm granules in the kinetoplast. These granules were seen mainly at the two extremities of the kinetoplast. Freeze‐fracture images indicate that the nuclear membrane contains ca. 9 pores/μm2 of nuclear surface area. The mean diameter of the pores was 80 nm. All these results suggest that epimastigotes of T. cruzi have a very active nucleus and a high rate of nucleocytoplasmic interchange.
The Biochemical Identification of Vahlkampfiid Amoebae1
Authors: DAGGETT PIERRE‐MARC , NERAD THOMAS A.
Published: May 2007

ABSTRACT. Isoenyme electrophoresis of three different enzymes was used to compare 16 strains of vahlkampfiid amoebae and a strain identified as a slime mold. The strain designated as an Echinostelium sp. was found to be an isolate of Naegleria fowleri on the basis of zymogram type and other characters, confirming Cursons & Brown's similar conclusion drawn in 1975. The N. fowleri strains examined expressed the typical zymograms of the species. The N. gruberi strains in this study presented two distinctive groups of patterns that were different from the two previously reported types for N. gruberi. Each of the remaining species studied formed single distinctive groups by which they could be identified.
Intraspecies Variability in the Esterases and Acid Phosphatases of Paramecium jenningsi and Paramecium multimicronucleatum: Assignment of Unidentified Paramecia; Comparison with the P. aurelia Complex1
Authors: ALLEN SALLY LYMAN , RUSHFORD CAROLINE L. , NERAD THOMAS A. , LAU ELIZABETH T.
Published: May 2007

ABSTRACT. Enzyme electrophoresis was exploited to identify stocks of paramecia previously not identified to particular species. Stocks collected in India and one from Panama belong to Paramecium jenningsi, while others collected in Panama or in Brazil are assignable to syngen 2 of P. multimicronucleatum on the basis of similarity of their esterase and acid phosphatase phenotypes. Inclusion of these doubled the numbers of stocks available in the two species, thereby facilitating examination of intraspecies variation and comparison of particular features of intraspecies variation found for the P. aurelia complex. Variant stocks were observed in P. jenningsi and in syngens 2, 3, and 4 of P. multimicronucleatum. In some cases the variant lacked the enzyme; in others, a change in mobility of the enzyme occurred that resulted in an electrophoretic form similar to one common in another species. Unique phenotypes were displayed by the variants of syngen 2 in P. multimicronucleatum. Hypervariability for Esterase B was observed in this syngen, where, in addition, several subtypes were seen for three other esterases. Unique phenotypes and hypervariability were also noted in P. biaurelia. Clustered variations were observed in these species and in the P. aurelia species. Unlike the situation for members of the aurelia complex, where lack of geographical differentiation between stocks in the same species is a unique feature, some such differentiation does occur in P. multimicronucleatum‐2. The frequency of variant stocks in P. jenningsi was similar to that observed in the aurelia sibling species. In contrast, a significantly higher frequency of variant stocks was found in syngens 2, 3, and 4 of P. multimicronucleatum.
Generation of Mechanical Forces in Phagocytosing Amoebae: Light and Electron Microscopic Study1
Authors: JEON K. W. , JEON M. S.
Published: May 2007

Cells of Amoeba proteus and Chaos carolinensis that were in the process of phagocytosing large prey organisms were studied to find a structural basis for the generation of mechanical forces exerted by newly forming food cups. It was found that the food‐cup walls facing prey organisms have a more prominent network of thin filaments inside the plasmalemma and that the glycocalyx covering the area is more condensed than usual.
Uptake of Ferritin‐labeled Antibodies by Tetrahymena1
Authors: WILLIAMS NORMAN E.
Published: May 2007

Experiments with Tetrahymena thermophila using ferritin probes revealed that these cells take up ferritin conjugated to antibodies (not directed against Tetrahymena) much more readily than they do ferritin or cationized ferritin. The massive and rapid uptake of antibody‐ferritin offers certain advantages for studies of endocytosis and membrane flow in cells of this type, and the method may be applicable to other types of protozoa as well.
Myxosoma cerebralis (Myxozoa: Myxosporea) Etiologic Agent of Salmonid Whirling Disease Requires Tubificid Worm (Annelida: Oligochaeta) in its Life Cycle
Authors: MARKIW MARIA E. , WOLF KEN
Published: May 2007

Studies of the life cycle of Myxosoma cerebralis showed that development of infectivity did not occur endogenously but that the spore “aging” process required participation of an aquatic tubificid oligochaete. Data suggestive of such involvement were derived from trials in which spores were “aged” in an array of inert, sterilized, pasteurized, or natural aquatic substrates and from examination of aquatic soils from trout hatcheries in which whirling disease was epizootic. The role of the aquatic oligochaete was confirmed two ways. First, signs of whirling disease developed, and M. cerebralis spores were produced in young rainbow trout (Salmo gairdneri) that had been fed oligochaetes harvested from pond soil taken from two hatcheries where whirling disease was epizootic. Second, when containers of pasteurized soil were populated with four genera of oligochaetes–Aeolosoma, Dero, Stylaria, or Tubifex– from a biological supply house, or with tubificid worms from trout hatcheries free of whirling disease, and then seeded with M. cerebralis spores and “aged” for 4 months, whirling disease occurred only in trout held with Tubifex and with hatchery tubificids.
Divalent Cation‐dependent ATPase Activities Associated with Cilia and Other Subcellular Fractions of Paramecium: An Electrophoretic Characterization on Triton‐polyacrylamide Gels1
Authors: DOUGHTY MICHAEL J. , KANESHIRO EDNA S.
Published: May 2007

Several divalent cation‐dependent ATP phosphohydrolases associated with cilia, ciliary axonemes, ciliary membranes, pellicles, trichocysts, nuclei, mitochondria, microsomes, and soluble peripheral cell surface fractions of Paramecium tetraurelia were resolved in this study. Fifteen different activity bands were detected in whole cell sonicates or subcellular fractions by Triton polyacrylamide gel electrophoresis and ATPase activity staining. The ciliary surface membrane contained two major ATPase activities that were distinct from the enzymes associated with all other cell fractions.
Defined Minimal Growth Medium for Acanthamoeba polyphaga
Authors: INGALLS CONNIE S. , BRENT MORGAN M.
Published: May 2007

Nutritional requirements of Acanthamoeba polyphaga (strain PD) were compared to those reported for A. castellanii. Although A. polyphaga and A. castellanii have essentially the same minimal amino acid requirements–arginine, methionine, leucine, isoleucine, and valine–A. polyphaga cannot utilize acetate as sole carbon source, but A. castellanii can if the medium is supplemented with glycine.
Macromolecular Syntheses During the Quick‐Change Act of Naegleria1,2
Authors: FULTON CHANDLER
Published: May 2007

The rapid, synchronous differentiation of N. gruberi from amoebae to flagellates is a useful paradigm to study aspects of cell differentiation, including regulation of the synthesis of proteins that are related to the changes in cell shape and motility, which occur during differentiation. The differentiation requires synthesis of new RNA and protein molecules to accomplish defined morphogenetic events. Specific new proteins, including the tubulins that form the flagellar microtubules, are synthesized at various times during differentiation, and particular mRNA species appear and disappear. The time course of the synthesis of the α and β subunits of flagellar tubulin is paralleled by the programmed appearance and disappearance of flagellar tubulin mRNAs. The evidence supports the hypothesis that the synthesis of flagellar tubulin is regulated by the transcription, and subsequent disappearance, of flagellar tubulin mRNA. Translatable mRNAs for two calmodulin‐like calcium‐binding proteins appear and disappear contemporaneously with those for flagellar tubulin. During differentiation the synthesis of actin, the major protein of amoebae, is selectively shut down, and translatable actin mRNA rapidly disappears. This description of the orderly appearance, utilization, and disappearance of the mRNAs for actin, calcium‐binding proteins, and flagellar tubulin during differentiation provides means and motivation to investigate the mechanisms that regulate these events.
Analysis of Mitochondrial DNA Variation as an Approach to Systematic Relationships in the Genus Acanthamoeba1
Authors: BYERS THOMAS J. , BOGLER SUSANA A. , BURIANEK LINDA L.
Published: May 2007

Classification at the species level has been difficult in the genus Acanthamoeba. The taxonomic designations of a number of strains are in doubt and new approaches to classification are needed. We describe the use of electrophoretic patterns obtained with restriction enzyme digests of mitochondrial DNA as a basis for one new approach. Results from analysis of ten strains of A. castellanii, two of A. polyphaga and one of A. astronyxis are discussed. Examples both of nucleotide sequence diversity and of sequence conservation have been found among strains with the same species designation. Five strains from Europe, North America and New Zealand had identical digestion phenotypes with five enzymes; consequently, very similar nucleotide sequences are predicted. All are pathogenic to humans or mice. The mtDNA sequences of eight remaining strains are predicted to differ from this cluster and, in most cases, from each other at least as much as in sibling species of Paramecium aurelia.
Control of Protein Synthesis in Acanthamoeba castellanii
Authors: JANTZEN HELGA , SCHULZE INGRID , HORSTMANN ULRIKE , CHRISTOFORI GERHARD
Published: May 2007

During development of Acanthamoeba castellanii in a non‐nutrient medium, the pattern of synthesis of proteins changes. Comparison of in vivo and in vitro patterns of protein synthesis reveals concomitant relative increases of five proteins, indicating a control of synthesis of these proteins at the level of the RNA content. The decrease in the overall rate of protein synthesis and relative decreases in the synthesis of actin and ribosomal proteins during development, not accompanied by equivalent changes in the content of mRNA, suggest control mechanisms also at the level of translation. Patterns of ribosomal proteins do not change qualitatively during encystation, indicating that the inhibition in the overall rate of protein synthesis and the formation of inactive monosomes is not controlled by this mechanism; however, phosphorylation of one ribosomal protein, S 3, is observed occasionally during encystation. Phosphorylation of S 3 is also detected after transfer of stationary phase cells into fresh nutrient medium. It was found that only such cells having RNA of aberrant properties are able to phosphorylate S 3 after transfer into fresh nutrient medium. Since these changes in the property of RNA are never observed in cysts, in which phosphorylation of S 3 sometimes occurs, it is concluded that either other alterations in the properties of RNA than those detected or other parameters are responsible for changes in phosphorylation of S 3.
Incubation in Mice Provides a Signal for the Differentiation of Trypanosoma cruzi Epimastigotes to Trypomastigotes1
Authors: SHER ALAN , CRANE MARK ST. J. , KIRCHHOFF LOUIS V.
Published: May 2007

The differentiation of Trypanosoma cruzi epimastigotes into trypomastigotes was studied in diffusion chambers sub‐cutaneously implanted in mice. Using epimastigotes of the Tulahuén strain, transformation was first evident at 16 h after implantation and reached its maximum (92% trypomastigotes) by 24 h. Shortly before their differentiation into trypomastigotes, epimastigotes were found to develop resistance to lysis by the alternative pathway of complement. Furthermore, implantation of stationary‐phase (as opposed to log‐phase) parasites resulted in the accumulation of large numbers of complement‐resistant epimastigotes in the chambers. These observations suggest that epimastigotes pass through a complement‐resistant transitional stage before differentiating into trypomastigotes and that transformation may require cell division. In a further series of experiments, epimastigotes recovered 7 h after implantation in mice were found to differentiate into trypomastigotes when cultured in vitro for an additional 17 h at 37°C. This observation indicates that the events which trigger the morphologic transformation of epimastigotes into trypomastigotes can be dissociated operationally from the differentiation process itself.