bluuebunny/crossref_metadata_2025 huggingface dataset:
Trypanosoma rhodesiense Bloodstream Trypomastigote and Culture Procyclic Cell Surface Carbohydrates1, 2, 3
Authors: JACKSON PETER R. , DIGGS CARTER L.
Published: May 2007

Bloodstream trypomastigote and culture procyclic (insect midgut) forms of a cloned T. rhodesiense variant (WRATat 1) were tested for agglutination with the lectins concanavalin A (Con A), phytohemagglutinin P (PP), soybean agglutinin (SBA), fucose binding protein (FBP), wheat germ agglutinin (WGA), and castor bean lectin (RCA). Fluorescence‐microscopic localization of lectin binding to both formalin‐fixed trypomastigotes and red cells was determined with fluorescein isothiocyanate (FITC)‐conjugated Con A, SBA, FBP, WGA, RCA, PNA (peanut agglutinin), DBA (Dolichos bifloris), and UEA (Ulex europaeus) lectins. Electron microscopic localization of lectin binding sites on bloodstream trypomastigotes was accomplished by the Con A‐horseradish peroxidase‐diaminobenzidine (HRP‐DAB) technique, and by a Con A‐biotin/avidin‐ferritin method. Trypomastigotes, isolated by centrifugation or filtration through DEAE‐cellulose or thawed after cryopreservation, were agglutinated by the lectins Con A and PP with agglutination strength scored as Con A < PP. No agglutination was observed in control preparations or with the lectins WGA, FBA or SBA. Red cells were agglutinated by all the lectins tested. Formalin‐fixed bloodstream trypomastigotes bound FITC‐Con A and FITC‐RCA but not FITC‐WGA, ‐SBA, ‐PNA, ‐UEA or ‐DBA lectins. All FITC‐labeled lectins bound to red cells. Con A receptors, visualized by Con A‐HRP‐DAB and Con A‐biotin/avidin‐ferritin techniques, were distributed uniformly on T. rhodesiense bloodstream forms. No lectin receptors were visualized on control preparations. Culture procyclics lacked a cell surface coat and were agglutinated by Con A and WGA but not RCA, SBA, PP and FBP. Procyclics were not agglutinated by lectins in the presence of competing sugar at 0.25 M. The expression of lectin binding cell surface saccharides of T. rhodesiense WRATat 1 is related to the parasite stage. Sugars resembling α‐D‐mannose are on the surface of bloodstream trypomastigotes and culture procyclics; n‐acetyl‐D‐galactosamine and D‐galactose residues are on bloodstream forms; and n‐acetyl‐D‐glucosamine‐like sugars are on procyclic stages.
Rumen Ciliates with Description of Two New Species from Three African Reedbuck Species
Authors: VAN HOVEN W.
Published: May 2007

Thirteen bohor reedbuck Redunca redunca wardi (Thomas, 1900) from Kenya and Tanzania, ten common reedbuck Redunca arundinum arundinum (Boddaert, 1785) from Zimbabwe and 34 mountain reedbuck Redunca fulvorufula fulvorufula (Afzelius, 1915) from South Africa were sampled. Twenty‐six protozoan species have been identified, 18 in the bohor reedbuck, which included seven entoninia, two new Diplodinium species, but no holotrichs. In the southern reedbuck 13 species were recorded, which included two entodinia, and 11 diplodinia including the two new species; holotrichs were also absent. The mountain reedbuck which is a mixed feeder as opposed to the grazers had 22 species including two holotrichs.
Isoenzyme and Total Protein Analysis by Agarose Isoelectric Focusing, and Taxonomy of the Genus Acanthamoeba
Authors: DE JONCKHEERE JOHAN F.
Published: May 2007

Thirty axenically grown reference strains belonging to 15 different Acanthamoeba spp. were investigated for isoenzyme patterns by agarose isoelectric focusing in the pH range 3–10. Zymograms of acid phosphatase, leucine amino peptidase, malate dehydrogenase, propionyl esterase, glucose phosphate isomerase, phosphoglucomutase, and alcohol dehydrogenase were compared. The same strains were also analyzed for protein patterns separated by agarose isoelectric focusing in a pH gradient of 5–8. The results suggested changes in taxonomy within morphology group II of Pussard & Pons. Acanthamoeba paradivionensis becomes a synonym of A. divionensis. Although this species seems to be related to A. rhysodes, it could not be concluded that the species names are synonyms since the type strain of A. rhysodes was not available for comparison. In the subgroup A. polyphaga–A. quina–A. lugdunensis, A. lugdunensis becomes the species name for pathogenic strains of this subroup, A. quina for the nonpathogenic strains, while A. polyphaga is the species name for an atypical strain. Two strains of A. castellanii showed different zymograms from strain Neff of this species, but related protein patterns. In group III, A. pustulosa is found to be a synonym of A. palestinensis, while one strain of A. lenticulata is also found to belong to the A. palestinensis species. All other species names in both morphology groups could be retained as valuable, on the basis of the techniques used. Group I was not investigated, as axenic cultures could not be obtained.
Effects of UV‐Radiation on Kinetics of Encystment and on Morphology of Resting Cysts of the Ciliate Laurentiella acuminata1
Authors: GUTIÉRREZ JUAN C. , PEREZ‐SILVA J.
Published: May 2007

The effects of ultraviolet radiation (λ= 254 nm) on the kinetics of encystment of the hypotrichous ciliate Laurentiella acuminata and the structure of resting cysts obtained from irradiated precystic cells are reported. High doses of UV‐radiation caused a delay of encystment with a linear increase in the average time for obtaining 50% of encystment (EN50). Resting cysts with abnormal cyst walls were obtained when precystic cells were irradiated in the exposure range 720 to 960 J/m2. The cystic layer (mesocyst) was approximately twice as thick (6.5 μ m) as normal (3.7 μ m). Microscopical observations of abnormal cysts revealed the presence of two complete mesocysts, and the absence of the spines characteristic of the ectocyst. The UV‐dependent effects on the cyst wall were gradually corrected in successive generations of the irradiated cells.
Acid Phosphatase in the Digestive Vacuoles and Lysosomes of Paramecium caudatum: A Timed Study1
Authors: FOK AGNES K. , MURAOKA JOANNE H. , ALLEN RICHARD D.
Published: May 2007

Enzyme cytochemistry was used to determine when acid phosphatase (AcPase) becomes associated with the digestive vacuoles (DVs) of axenically grown Paramecium caudatum that were pulsed with latex beads for 2–3 min. When cells were incubated in the Gomori medium, AcPase was not observed in the discoidal vesicles, the acidosomes, and the newly released DVs up to 3 min old or in most DVs 3–6 min old. The number of AcPase‐positive DVs increased to 56% when DVs were 12–18 min old. Similar results were obtained using the napthol AS‐TR phosphate‐hexaotized rosanilin method at the light microscopic level where hundreds of DVs were scored though the maximal level of positive DVs obtained by this method was lower. In addition to DVs of specific ages, AcPase was found in ER, in some Golgi vesicles, and small vesicles similar in diameter to Golgi vesicles which may represent primary lysosomes in this ciliate. Larger vesicles abundant near the DV‐II were only partially filled with reaction product. These vesicles, which could be identified by their paracrystalline sheets and a prominent glycocalyx lining the luminal surface of their membranes, fit the definition for secondary lysosomes. These results, which indicate that lysosomes fuse with DVs only after they have attained a certain age, suggest the existence of specific recognition factors on the membranes of secondary lysosomes as well as DV‐II.
Local and Systemic Effects on Inflammation during Eimeria nieschulzi Infection1
Authors: CASTRO GILBERT A. , DUSZYNSKI DONALD W.
Published: May 2007

Rats infected with Eimeria nieschulzi, a coccidium that inhabits intestinal epithelium, have a lower basal inflammatory state in their intestinal mucosa eight days postinoculation as reflected by a drop in mucosal peroxidase activity and a decrease in the number of granulocytes in the lamina propria. The reduction of systemic inflammation in infected rats was assessed from a reduction in the formation of granulation tissue around a sterile cotton string implanted under the abdominal skin of the hosts. This reduced inflammatory response, both locally and systemically, occurs during the development of gamonts by the parasite and the release of oocysts from the host. These results plus the presence of normal or slightly elevated numbers of granulocytes in peripheral blood lead to the conclusion that the parasite does not affect hematopoiesis but interferes with some phase in the directed migration of leukocytes to specific sites.
Protein Similarities in the Genus Tetrahymena and a Description of Tetrahymena leucophrys n. sp.1
Authors: WILLIAMS NORMAN E. , BUHSE HOWARD E. , SMITH MARLYN G.
Published: May 2007

The potential utility of protein arrays visualized by SDS‐PAGE in taxonomic studies of protozoa has been investigated within the genus Tetrahymena. Matching coefficients have been obtained from one‐dimensional separations of cytoskeletal proteins in a study involving 40 strains of Tetrahymena. In separate studies, the method was estimated to be accurate to within 10%, and the limit of intraspecific variation within the genus was estimated at ≅ 30%. Accordingly, it is suggested that strains showing matching coefficients 0.6 in these preparations probably represent different species. Further tests using strains identified to species by breeding criteria have shown that the 0.6 rule is asymmetric, i.e. although matching coefficients lower than this indicate separate species, values higher than this do not prove identity. Protein comparisons included in the present study indicate that strain Tur, previously identified as a strain of T. vorax, is distinct from all other macrostome‐forming species. It is here designated Tetrahymena leucophrys n. sp.
The Coccidian Genus Calyptospora n. g. and Family Calyptosporidae n. fam. (Apicomplexa), with Members Infecting Primarily Fishes1
Authors: OVERSTREET ROBIN M. , HAWKINS WILLIAM E. , FOURNIE JOHN W.
Published: May 2007

Calyptospora n. g. was erected for Eimeria funduli because the sporocyst of that species lacks Stieda and sub‐Stieda bodies, has a veil supported by sporopodia, and has an anterior apical opening. A suture may be present, but it does not completely divide the sporocyst into two valves. Because C. funduli has an obligatory invertebrate intermediate host, we established Calyptosporidae n. fam. to accommodate Calyptospora and tentatively to accept Goussia. A new subgenus, Plagula, is erected for species of Goussia with a sporocystic veil not supported by sporopodia. We consider the family more primitive than Eimeriidae, Sarcocystidae, and possibly Lankesterellidae.
Morphological and Developmental Studies of the Snake Trypanosome Trypanosoma hydrae Ayala, Atkinson, Vakalis, 1983 in Experimentally Infected Hosts and in Culture
Authors: CHIA NOEL M. , MILLER JOSEPH H.
Published: May 2007

Trypanosoma hydrae from the broad‐banded watersnake, Nerodia fasciata confluens, underwent development in the freshwater leech, Placobdella parasitica. Epimastigotes and transitional stages were present only in the crop and gastric caecum. Only one metacyclic form was observed. The potential of leeches as vectors is discussed.

Two broad‐banded watersnakes were infected by inoculation with culture forms of T. hydrae maintained on NNN medium. Parasitemias varied from 105/ml to 106/ml with dividing forms seen only rarely. A broad and a slender form of T. hydrae are described from the peripheral blood of a watersnake 7 months after an experimental infection.
Caryospora corallae n. sp. (Apicomplexa: Sporozoea, Eimeriidae) from the Emerald Tree Boa Corallus caninus (Serpentes: Boidae)
Authors: MATUSCHKA FRANZ‐RAINER
Published: May 2007

Oocysts of Caryospora corallae n. sp. were isolated from the feces of three Emerald Tree Boas Corallus caninus. The spherical oocysts of C. corallae averaged 22.4 μn (range 18.7 to 24.6) in diameter and were lacking a micropyle and oocyst residuum; a polar granule was present. The ovoid sporocysts measured 19.1(17.6‐20.0) × 13.1(11.7‐14.0) μm and a sporocyst residuum and a Stieda body were present. The oocyst wall was approximately 1 μm thick. The sporulation was completed in about 5–6 days at 23 ± 2°C. This is the first report of the genus Caryospora from Corallus caninus a member of the Boidae.
Extraintestinal Development of Caryospora simplex (Apicomplexa: Eimeriidae) in Experimentally Infected Mice, Mus musculus1
Authors: UPTON STEVE J. , CURRENT WILLIAM L. , ERNST JOHN V. , BARNARD SUSAN M.
Published: May 2007

Developmental stages of Caryospora simplex were found in connective tissue of the cheek, tongue, and nose of Swiss‐Webster and C57 BL/6 mice (Mus musculus) from 8 through 70 days after oral inoculation with 50,000 or 250,000 oocysts, or 60,000 free sporocysts of the same species obtained from an Ottoman viper, Vipera xanthina xanthina. The earliest developmental stages were seen on day 8 post‐inoculation (PI) and consisted of two types of meronts and gamonts (undifferentiated sexual stages). Gamonts, microgametocytes, macrogametes, and unsporulated oocysts were found on days 10 and 12 PI. Fully sporulated, thin‐walled oocysts containing eight sporozoites surrounded by a thin sporocyst membrane were first seen 12 days PI. Monozoic cysts (caryocysts) were first seen 12 days PI and appeared fully viable throughout the duration of the study, 70 days PI. Four mice injected intra‐peritoneally with 150,000 free sporozoites and killed 12 days PI contained unsporulated and sporulated oocysts in connective tissues of the cheek, tongue, and nose, suggesting that sporozoites may be carried to the site of infection via the lymphatic/circulatory system. Four cotton rats, Sigmodon hispidus, inoculated orally with 250,000 oocysts all had unsporulated and sporulated oocysts of C. simplex in connective tissue of the cheek, tongue, and nose when killed on day 12 PI, indicating extraintestinal development in the secondary host is not species specific. This is the first report of a heteroxenous coccidium with both asexual and sexual development in the primary (predator) and secondary (prey) hosts.
Occurrence of Amoebae on Oak Leaf Lettuce (Lactuca sativa var. crispa) and Boston Lettuce (L. sativa var. capitata)1
Authors: NAPOLITANO JOSEPH J. , COLLETTI‐EGGOLT CLAUDIA
Published: May 2007

The colonization, distribution, population density, and species diversity of amoebae on leaves of Oak Leaf lettuce, Lactuca sativa var. crispa, and Boston lettuce, L. sativa var. capitata, were investigated. The role of soil in the colonization of Oak Leaf lettuce was determined by comparing numbers of amoebae present on basal leaves (those that pass through soil) with numbers on wrapped leaves (those that do not pass through soil). Amoebae were present in ten samples of basal leaves and ranged from 154–1510/g of leaf tissue. Wrapped leaves failed to yield amoebae in seven of ten trials and contained <4 amoebae/g of tissue. Mean values for the population density of amoebae on Oak Leaf basal leaves and Boston lettuce leaves were 484 ± 133 and 453 ± 93, respectively. The distribution of amoebae on green and white parts of leaves from both kinds of lettuce was studied. The occurrence of amoebae on rinsed, unrinsed, visibly clean, and visibly dirty samples of Boston lettuce leaves was established.
Entamoeba histolytica: Collagenolytic Activity and Virulence1
Authors: MUÑOZ MARÍA DE LOURDES , ROJKIND MARCOS , CALDERÓN JESÚS , TANIMOTO MIGUEL , ARIAS‐NEGRETE SERGIO , MARTÍNEZ‐PALOMO ADOLFO
Published: May 2007

Several axenic strains of pathogenic and nonpathogenic Entamoeba histolytica were tested for their capacity to digest native radioactive type I collagen gels and to produce liver abscesses when injected into the liver of newborn hamsters. The results demonstrate that the pathogenic strains of amebas (HM1:IMSS, HM3:IMSS, HM38:IMSS, and HK9) have a collagenolytic activity that closely correlates with their in vivo capacity to produce liver lesions. The nonpathogenic isolate (Laredo) did not show collagenolytic activity and failed to produce lesions in the liver of newborn hamsters. The results also demonstrate that type I collagen obtained from rodents and cats is degraded less by amebic collagenase than is bovine collagen, which is similar to human collagen. These findings suggest that species susceptibility to invasive infection may depend, among other factors, on the characteristics of the extracellular components of host tissues.
Enhanced Multiplication of Intracellular (Amastigote) Stages of Trypanosoma cruzi In Vitro1
Authors: VILLALTA FERNANDO , KIERSZENBAUM FELIPE
Published: May 2007

Amastigotes of different strains of Trypanosoma cruzi responded to stimulation with concanavalin A in an axenic medium by increased DNA synthesis and cell multiplication. These effects were inhibited by α‐methyl mannoside. Other mitogens, i.e. phytohemagglutinin P, castor bean ricin Type II isolated from Ricinus communis, and a bacterial lipopolysaccharide, had no effect on amastigote growth. Amastigote stimulation by concanavlin A lends itself to studies on the biochemistry and cell cycle of this human pathogen.
Macronuclear Events and Some Morphogenetic Details During the Excystment of Onychodromus acuminatus (Ciliophora, Hypotrichia)
Authors: JAREÑO M. A.
Published: May 2007

Light microscopy of stained (protargol, Feulgen, aceto‐orcein, methyl green‐pyronin) specimens of Onychodromus acuminatus during excystment shows that the macronucleus appears during the first hour as a warped ribbon with variable density and width and with sharpened ends. One extraordinary point that reaches the cortex is frequently seen in front of a small granule where the bundle of positioning fibers arises. The macronucleus returns to its previous form, with rounded edges, at the end of cortical morphogenesis, and later divides twice. Some details of cortical morphogenesis during the excystment process are discussed.
DNA Rearrangements of the Variable Surface Antigen Genes of the Trypanosomes1
Authors: MURPHY WILLIAM J. , BRENTANO STEVEN T. , RICE‐FICHT ALLISON C. , DORFMAN DAVID M. , DONELSON JOHN E.
Published: May 2007

The trypanosome genome contains several hundred (and perhaps several thousand) genes for the trypanosome variable surface glycoproteins (VSGs). In an individual trypanosome only one of these genes is expressed at a given instant; the others are transcriptionally silent. This differential gene expression is responsible for the sequential antigenic variation displayed by trypanosomes. It is mediated by two types of genomic rearrangements of these VSG genes. The best understood rearrangement type is the formation of a transcriptionally‐active expression‐linked extra copy (ELC) of a transcriptionally‐silent basic copy (BC) gene. This duplication and translocation event places the ELC near a chromosomal end (a telomere) where it is apparently located downstream from a strong promotor. Some VSG genes are not expressed via this ELC mechanism. These genes, which seem to already be near telomeres, are activated by a different non‐duplication associated (NDA) type of mechanism. We have used recombinant DNA techniques to clone and determine the sequences of genes expressed by both the ELC and NDA mechanisms. Comparison of these sequences reveals that sequences flanking the VSG coding regions are similar. This indicates that there is a sequence correlation between the two mechanisms of expression. We have also shown that when bloodstream trypanosomes expressing a specific VSG via the ELC mechanism are established in culture the resultant procyclic trypanosomes rapidly stop synthesizing the VSG mRNA (and the VSG) but retain the ELC of the VSG gene. This demonstrates that transcription of an ELC can cease without the loss of that ELC and may indicate the presence of other factors regulating VSG gene transcription.
A Freeze‐Fracture Electron Microscope Study of Trichomonas vaginalis Donné and Tritrichomonas foetus (Riedmüller)1
Authors: HONIGBERG B. M. , VOLKMANN DIETER , ENTZEROTH ROLF , SCHOLTYSECK ERICH
Published: May 2007

Two strains of Trichomonas vaginalis, JH162A, with low pathogenicity, and Balt 44, with high pathogenicity, as well as one highly pathogenic strain, KV‐1, of Tritrichomonas foetus were studied by freeze‐fracture electron microscopy.

The protoplasmic faces (PFs) of the cell membranes of all three strains of both species had similar numbers of intramembranous particles (IMPs); however, the particles in the external faces (EFs) of these membranes were least abundant in Trichomonas vaginalis strain Balt 44 and most numerous in those of strain JH162A of this species. In Tritrichomonas foetus strain KV‐1 the number of IMPs in the EF was close to but somewhat lower than that in the mild strain of the human urogenital trichomonad. In both species, the anterior, but not the recurrent, flagella had rosette‐like formations, consisting of ∼9 to 12 IMPs on both the PFs and EFs. The numbers and distribution of the rosettes appeared to vary among different flagella and in different areas of individual flagella of a single organism belonging to either species. The freeze‐fracture electron micrographs provided a more complete understanding of the fine structure of undulating membranes of Trichomonadinae, as represented by Trichomonas vaginalis, and of Tritrichomonadinae (the Tritrichomonas augusta‐type), as exemplified by Tritrichomonas foetus, than was gained from previous transmission and scanning electron microscope studies. Typically three longitudinal rows of IMPs on the PF of the recurrent flagellum of Trichomonas vaginalis were noted in the area of attachment of this flagellum to the undulating membrane. The functional aspects of the various structures and differences between certain organelles revealed in the two trichomonad species by the freeze‐fracture method are discussed.
Surface Anionic Groups in Symbiote‐Bearing and Symbiote‐Free Strains ofCrithidia deanei1
Authors: ODA LEILA M. , ALVIANO CELUTA S. , FILHO FERNANDO C. SILVA , ANGLUSTER JAYME , ROITMAN ISAAC , SOUZA WANDERLEY DE
Published: May 2007

The surface anionic groups of symbiote‐bearing and symbiote‐free strains ofCrithidia deaneiwere compared by determining cellular electrophoretic mobility, by ultrastructural cytochemistry, and by identification of sialic acids by thin‐layer and gasliquid chromatography. Symbiote‐freeCrithidia deaneihas a highly negative surface charge (‐0.9984 μmċs‐1ċ V‐1ċ cm), which is slightly reduced (‐0.8527 μmċs‐1ċ V‐1ċ cm) by the presence of the endosymbiote. Treatment of both strains ofC. deaneiwith neuraminidase decreased significantly the electrophoretic mobility of cells toward the cathodic pole, indicating the existence of exposed sialic acid residues responsible for the negative charge on the protozoan cell surface. Thin‐layer and gas‐liquid chromatography showed thatN‐glycolyl‐ andN‐acetylneuraminic acids were present in both strains ofC. deanei.
Variations in Expression of Markers by Populations of Adherent Cells from Trypanosoma cruzi‐Infected Mice1
Authors: WIRTH JULIA J. , KIERSZENBAUM FELIPE
Published: May 2007

The kinetics of differentiation and maturation of phagocytic cells during the acute and chronic stages of experimental Chagas' disease was examined by monitoring changes in expression of peroxidase (PO), nonspecific esterase (NSE), C3b receptors (CR), Fc receptors (FcR), and phagocytic ability of cells in the blood, spleen, and peritoneal cavity. The significant changes recorded in the blood were: marked increases in the percentages of CR‐ and FcR‐positive adherent cells during both the acute and chronic phase; Ia‐positive cells increased two‐fold in the acute period and remained elevated in the chronic stage. In the spleen, the major alterations recorded during both the acute and chronic stages were: two‐ to three‐fold increases in the percentages of NSE‐ and PO‐positive adherent cells and three‐ to four‐fold increases in the proportions of CR‐ and FcR‐positive cells. In addition, Ia‐positive cells increased from 70% to approximately 90% of the adherent cell population. In the peritoneal cavity, a two‐ to four‐fold elevation in the percentages of both PO‐ and NSE‐positive cells was observed. The number of Ia‐positive cells increased from 10% before infection to 85–90% during the acute phase and to 96–98% during the chronic period. All of the changes described above occurred in the absence of noticeable increases in phagocytic ability except for an elevation in the percentage of circulating latex‐ingesting cells seen during chronicity. These results indicate that infection with Trypanosoma cruzi alters the pathways of differentiation of cells of the mononuclear phagocyte lineage.
A New Malaria Parasite Plasmodium (Sauramoeba) heischi in Skinks (Mabuya striata) from Nairobi, with a Brief Discussion of the Distribution of Malaria Parasites in the Family Scincidae
Authors: GARNHAM P. C. C. , TELFORD SAM R.
Published: May 2007

ABSTRACT. A new species of malaria parasite, Plasmodium (Sauramoeba) heischi, is described from African skinks (Mabuya striata). Eleven individuals of 90 specimens collected in Nairobi were found to be infected. The new parasite is a large species, characterized by spindle‐shaped gametocytes, the female often with a subterminal nucleus. The schizonts produce up to 65 nuclei and cause great hypertrophy and distortion of the host cell. Although similar to P. (Sauramoeba) giganteum in dimensions and merozoite numbers, P. heischi is easily distinguished by gametocyte and schizont shapes.
The Effects of Reducing Conditions, Medium, pH, Temperature, and Time on in Vitro Excystation of Cryptosporidium
Authors: FAYER R. , LEEK R. G.
Published: May 2007

ABSTRACT. Whereas excystation of sporozoites from oocysts of most coccidian species requires exposure to reducing conditions followed by pancreatic enzymes and bile salts, sporozoites of a bovine isolate of Cryptosporidium excysted without exposure to either reducing conditions or to pancreatic enzymes and bile salts. Without prior exposure to reducing conditions, a high percent excysted after incubation in a mixture of trypsin and bile salts in Ringer's solution; fewer excysted after incubation in tap water, even fewer after incubation in salt solutions, and none after incubation in saliva. Excystation, generally greater at pH 7.6 than at pH 6.0 and at 37°C than at 20°C, was observed as early as 1 h after incubation in water or the trypsin‐bile mixture. These findings provide circumstantial evidence that oocysts of Cryptosporidium can excyst in extraintestinal sites and liberate sporozoites that can initiate autoinfection.
Stercorarian Trypanosomes from Deer (Cervidae) in Germany1,2,3
Authors: HOFFMANN MANFRED , BUSCHER GOTTFRIED , FRIEDHOFF KARL T.
Published: May 2007

ABSTRACT. Twenty of 35 roe deer (Capreolus capreolus), eight of 12 red deer (Cervus elaphus), and nine of 21 fallow deer (Cervus da ma) but none of four moose (Alces alces) examined from April to November 1983 were infected with trypanosomes. Morphometric data of the bloodstream trypomastigotes from the three deer species differed significantly. This appears to be the first report of stercorarian trypanosomes from Cervidae in the Old World and the first description of representatives of the subgenus Megatrypanum in the three deer species.
Amebostomes of Naegleria fowleri1
Authors: John D. T. , Cole T. B. , Bruner R. A.
Published: May 2007

The strain of ameba, culture incubation temperature, and phase of ameba growth affected the number of amebostomes present on amebae of Naegleria fowleri. Serial passage of N. fowleri through mice decreased the average number of amebostomes. Amebostomes were shown to be functional by their ability to engulf yeast cells.
Comparative Study of the Ribosomal RNA from Leishmania and Trypanosoma1
Authors: Villalba Elena , Dorta Bias , Ramírez José Lues
Published: May 2007

The ribosomal RNA from several stocks of the genera Leishmania and Trypanosoma were studied by gel electrophoresis, sedimentation on sucrose density gradients and RNA/DNA hybridization experiments. Three major components were observed after electrophoresis in polyacrylamide gels (PAGE‐SDS), the relative molecular masses being respectively: X1= 0.83 megadaltons, X2= 0.63 megadaltons and X3= 0.54 megadaltons for Leishmania RNA; and X1= 0.86 megaldaltons, X2= 0.78 megadaltons, and X3= 0.58 megadaltons for Trypanosoma RNA. Depending upon the isolation procedure, a fourth component. X0= 1.2 megadaltons (26S), became evident. The later component was purified from Leishmania brasiliensis (Y) by centrifugation on a linear 15‐30% sucrose density gradient. This component, after heat denaturation and PAGE‐SDS, gave rise to two bands coinciding in molecular mass with those of X2 and X3 indicating that these components are part of the large ribosomal subunit whereas X1 belongs to the small one. The above mentioned differences in mobilities of components X1 and X2 between the two genera were no longer observed after electrophoresis in denaturing agarose‐formaldehyde gels, suggesting secondary structural differences among these RNA species. Hybridization experiments with L. brasiliensis (Y) DNA showed that both RNA types compete equally well for the ribosomal sites in this DNA, and that L. brasiliensis (Y) rRNA recognizes the ribosomal sites in DNA of Trypanosoma cruzi (EP), thus indicating that no gross changes occurred in their nucleotide sequences during evolution.
Ionic Control of the Longitudinal Flagellum in Ceratium tripos (Dinoflagellida)1
Authors: Maruyama Tadashi
Published: May 2007

In order to answer the question of how two dissimilar flagellar motions, retraction and undulation, of the longitudinal flagellum in Ceratium tripos are regulated, the effects of cationic milieu, calcium ionophore, calcium channel blockers and some anesthetics on the motion of the longitudinal flagellum were studied. The flagellum retracted and was installed in the sulcus in high K+, high Ca2+, low Na+‐ASW (artificial sea water), and low Mg2+‐ASW. Although Ca2+ ionophore X537A induced the retraction, it also induced disintegration of the flagellum. The Ca2+ channel blocker, La3+, prevented the retraction effectively in high K+‐ASW and in low Mg2+‐ASW but did not affect it in low Na−‐ASW or in high Ca2+‐ASW. Ruthenium red (RR), on the other hand, prevented the retraction in high Ca2+‐ASW, low Na+‐ASW, and low Mg2+‐ASW but did not suppress the retraction induced in high K+‐ASW. The organic Ca2+ antagonist, verapamil, or the local anesthetics, dibucaine and papaveline, did not prevent the retraction effectively in any ASW. These data suggest that the flagellum retracts when external Ca2+ enters into the flagellum. The dissimilar actions of La3+ and RR suggest that there may be two different sites for Ca2+ influx which have different affinity for La3+ or RR.
Oral Ultrastructure and Oral Development of the Misaligned Undulating Membrane Mutant of Tetrahymena thermophila1
Authors: Lansing Timothy J. , Franker Joseph , Jenkins Leslie M.
Published: May 2007

The misaligned undulating membrane (mum) mutant of Tetrahymena thermophila is a non‐conditional, single gene recessive mutation. The major effect of the mum mutation is the production of multiple undulating membrane (UM) fragments in the oral apparatus (OA). The ultrastructure of the UM fragments of mum OAs is identical to that of the single UM of wild‐type OAs. Analysis of OA development at midbody using a combination of light microscopy of protargol‐stained cells and SEM of demembranated whole cells showed that the phenotypic effect of the mum mutation first becomes evident during mid to late stage 4 and is fully manifested in early stage 5. The effect of the mutation involves a proliferation of excess basal bodies in the UM field. Subsequent events in the development of the mum OA from mid to late stage 5 are identical to those in wild‐type OAs. This study suggests that the mum mutation establishes conditions that allow the production of multiple UMs and thus reveals that the UM field is competent for the complete and coordinated development of several adjacent UMs. This level of regional control is not clearly evident when a single UM is present.

The comparison of development of wild‐type and mum OAs required an extensive reanalysis of stages 4 and 5 of normal oral development. On the basis of current and previous observations, we propose a new and more subdivided staging system for oral development in Tetrahymena.
Scanning Electron Microscopy of Developmental Stages of Malpighamoeba mellificae Prell in the Honey Bee
Authors: Liu T. P.
Published: May 2007

Primary trophozoites of Malpighamoeba mellificae Prell in the process of penetrating the cell membrane were found among the brush border of epithelial cells of the midgut of Apis mellifera L. They were long and slender with an average diameter of 3.68 μm. Their surfaces had some wrinkles and the cytoplasm contained some vesicles. Secondary trophozoites were found in the lumen of Malpighian tubules. Their size was variable and their shapes were highly irregular; some had pseudopodia. The smooth surface of trophozoites possessed numerous small protrusions and pits. Mature cysts were small and oval‐shaped; they measured from 2.65 times 3.62‐3.4 times 4.6 μm. Their surface was usually smooth but some had wrinkles.
New Wild Tetrahymena from Southeast Asia, China, and North America, Including T. malaccensis, T. asiatica, T. nanneyi, T. caudata, and T. silvana n. spp.
Authors: Simon Ellen M. , Meyer E. Barbara , Preparata Rosa Maria
Published: May 2007

Tetrahymena of the T. pyriformis complex collected from varied habitats in Malaysia, Thailand, and The People's Republic of China include strains of the micronucleate species T. americanis and T. canadensis and the amicronucleate T. Pyriformis and T. elliotti. Two new breeding species are described—T. malaccensis from Malaysia and T. asiatica from China and Thailand. Two wild selfers from China and some of the amicronucleate strains from all three countries fall into isozymic groups similar to named micronucleate and amicronucleate species. The T. patula complex is represented by two groups of clones from Malaysia that fit the morphological description of T. vorax. They, however, have radically different isozymic electrophoretic patterns and both groups differ from those of previously described T. vorax. As their molecules indicate relationships to other “T. vorax” strains as distant as that between T. vorax and T. leucophrys, they are considered to be new species, T. caudata and T. silvana. A third new breeding species, T. nanneyi, was identified among strains previously collected in North America. Viable immature progeny were obtained from the new strains of the five breeding species. Maximum temperature tolerances were determined for the new strains of four of the breeding species.
Ultrastructure and Description of a New Species of Telomyxa (Microspora: Telomyxidae) from the Semiaquatic Beetle, Ora texana Champ. (Coleoptera: Helodidae)1
Authors: Hazard E. I. , Federici B. A.
Published: May 2007

A new species of the uncommon microsporidian genus Telomyxa (Microspora: Telomyxidae) has been found parasitizing the larval fat body of the semiaquatic beetle, Ora texana. In this species, the sporogonic sequence results in the formation of sporocysts measuring 7.7 times 6.5 μm that contain two crested uninucleate spores (averaging 5.7 times 2.2 μm). The spores are essentially oblong/ovate, tapering toward the anterior end and remaining bound together after sporogony by a persistent accessory membrane or sporocyst. The two spores in the sporocyst are produced by an unusual morphogenetic sequence in which, after one mitosis, the binucleate sporont elongates, forming two lobes that fold toward one another and cleave along a central plane, forming two parallel sporoblasts. The general ultrastructural features of this process are described, and diagnostic characters of this new species of Telomyxa are presented.
Caryospora cobrae n. sp. from the Indian Cobra Naja naja Linnaeus
Authors: Nandi Rina
Published: May 2007

Oocysts of Caryospora cobrae n. sp. were isolated from an Indian cobra, Naja naja Linnaeus from West Bengal, India. The sporulated oocysts were spherical to subspherical, 16.5‐19.5 times 16.5‐18.0 μm, and had a micropyle but lacked a polar granule and oocysl residuum. The sporocysts were piriform, measuring 12.0‐16.5 times 9.0−12.8 μm; a Stieda body and sporocyst residuum were present.
The Cytology of Sheep Rumen Ciliates. II. Ultrastructure of Eudiplodinium maggii1
Authors: Furness D. N. , Butler R. D.
Published: May 2007

The anterior adoral zone of syncilia (AZS) of Eudiplodinium maggii is mounted on an extrusible peristome within a vestibulum. The peristome contains cytopharyngeal components derived from the infraciliature. These components include a crescent‐shaped palisade of nematodesmata, two types of sub‐membrane cytopharyngeal ribbons, and an ensheathing fibrous layer enclosing a phagoplasmic zone containing the other components. A convoluted esophagus is continuous with and extends from the posterior of the cytopharynx adjacent to the macronucleus. A posterior cytoproct has specialized cytoplasm around it and associated myoneme‐like elements. The skeletal plate is composed of finely granular platelets and lies under the cortex ventral to the macronucleus. The endoplasm is separated from the ectoplasm by a fibrous boundary layer. The cortex has an external glycocalyx, a membranous layer, epiplasm, and microtubular and microfilament layers. The AZS infraciliature is of the usual cntodiniomorph type, kinetosomes linked by a sub‐kinetosomal rod and with associated bifurcated kinetodesma, postciliary and transverse microtubules‐the latter extending into the cytopharynx—nematodesmata, and a fibrous reticulum. A possible vestigial, somatic infraciliature consisting of short, barren kinetosomes with associated basal and cortex‐directed microtubules and a periodic incomplete fiber, is found subcortically throughout the cell.
Paramoeba invadens n. sp. (Amoebida, Paramoebidae), a Pathogenic Amoeba from the Sea Urchin, Strongylocentrotus droebachiensis, in Eastern Canada1
Authors: JONES G. M.
Published: May 2007

Paramoeba invadens n. sp. is described from sea urchin tissues and from culture. Amoebae are 20–40 μm in length with an irregular hyaline region producing short subpseudopodia. One parasome per cell is present. The parasome is bipolar with basophilic, Feulgen‐positive poles and a Feulgen‐negative median segment. The fine structure of the parasome resembles those in other species of Paramoeba and the surface of the amoeba is plain with no hairs or scales. Amoebae dislodged from tissues often adopt a semifloating form; floating forms have been seen in culture. Amoebae circulate within lumina of the water vascular system and can migrate readily into or out of tissues.
Microsporidium novacastriensis n. sp., a Microsporidian Parasite of the Grey Field Slug, Deroceras reticulatum1,2
Authors: JONES ANDREW A. , SELMAN BRIAN J.
Published: May 2007

A new species of microsporidium (phylum Microspora), Microsporidium novacastriensis n. sp., from the grey field slug, Deroceras reticulatum, is described on the basis of light and electron microscope studies. Meronts are spherical at first, then become irregular as nuclear number increases. Sporonts are tubular or ribbon‐like and divide unevenly to produce sporoblasts and then spores of varying lengths. Sporogonial stages are enclosed in a vesicle by a subpersistent membrane of uncertain origin. Fresh spores measure 3.5 by 2.08 μm and are produced in clusters of 12 to 120. The parasite infects only the intestinal epithelium of the slug. The new species is compared to microsporidia of other gastropod molluscs and to other microsporidia of similar developmental pattern and morphology.
Consideration of Taxonomic‐Nomenclatural Problems Posed by Report of Myxosporidians with a Two‐Host Life Cycle1
Authors: CORLISS JOHN O.
Published: May 2007

The recent report of two hosts in the life cycle of the myxosporidian parasite causing whirling disease in rainbow trout left unresolved several important taxonomic‐nomenclatural problems that are thus treated here. Although the spore morphology is totally different in the invertebrate host, the species involved can legally have but one name, viz., Myxobolus cerebralis Hofer, 1903 (until 1984, widely known under the name “Myxosoma cerebralis”). The “actinomyxidean” stage found in tubificid worms could have been tentatively assigned to the genus Triactinomyxon only if the latter had been considered as a collective‐group name. While intermediate ranks are also affected, even the high‐level groups Myxosporidia and Actinomyxidea, long considered taxonomically separate in conventional protozoan classification schemes, must be redefined. If future investigations confirm the existence of a two‐host life cycle for Myxobolus cerebralis and perhaps for other related myxosporidian fish parasites, then the phylogenetic distinctiveness of Myxosporidia and Actinomyxidea has been undermined and perhaps they can no longer be treated as evolutionarily divergent assemblages.
The Excystment Process in the Ciliate Euplotes muscicola: An Integrated Light and Scanning Electron Microscopic Study1
Authors: RAWLINSON NANCY G. , GATES MICHAEL A.
Published: May 2007

Resting cysts and the excystment process in the freshwater ciliate Euplotes muscicola were studied by both light and scanning electron microscopy. Groups of distinctly crested resting cysts adhere to the substrate. Silver‐stained preparations reveal surface conservation of dorsal kinetosomes and dorsal argyrome while ventral organelles are directed inward. Excystment involves the development of an expanding excystment vacuole concurrent with a localized thinning on the dorsal cyst wall surface. Cells exit through the pre‐formed ostiole, mid‐dorsal region first, initially by the force of cytoplasmic streaming, but later aided by cirral movement. Newly emerged cells retain the excystment vacuole and show no dorsal ridging. As the cell expels its excystment vacuole and partially unfolds, normal trophont morphology is re‐established. Both cyst structure and cyst typology have implications for hypotrich taxonomy.
Nuclear Roles in the Post‐Conjugant Development of the Ciliate Euplotes aediculatus. III. Roles of Old Macronuclear Fragments in Nuclear and Cortical Development1
Authors: FIDLER SUSAN J. , JAYARAMAN SHASHIKALA , KLOETZEL JOHN A.
Published: May 2007

Following conjugation of the hypotrichous ciliate Euplotes aediculatus, the posterior fragments of the old (prezygotic) macronucleus persist until after the first vegetative division. These fragments remain viable during exconjugant development as shown by their ability to regenerate should the cell's new macronucleus be damaged. It thus seemed possible that these parental nuclear fragments might participate in the development of the new macronucleus and/or the crucial post‐conjugant cortical reorganization that restores the exconjugant cell's ability to feed. This idea was tested by damaging the posterior fragments with various doses of microbeam ultraviolet (UV) light and assessing the results of such treatment on subsequent cortical and nuclear development. When the posterior fragments of the macronucleus were irradiated at the beginning of cortical morphogenesis, the new macronucleus in 1/3 to 1/2 of the cells assumed a “folded” appearance but did not mature. These cells did not undergo cortical reorganization. Cells irradiated at earlier stages did not detectably develop an oral apparatus; their new macronucleus remained arrested at the spherical anlage stage. The results show that the posterior fragments of the parental macronucleus are necessary for normal nuclear and cortical development. These old nuclear fragments appear to influence the growing macronuclear anlage directly and probably the cortex as well. There also appears to be an information flow from the non‐irradiated partner of a persistently joined exconjugant doublet to its irradiated counterpart, enabling normal anlage and cortex development in the irradiated cell.
Updating rDNA Restriction Enzyme Maps of Tetrahymena Reveals Four New Intron‐Containing Species1
Authors: NIELSEN HENRIK , SIMON ELLEN M. , ENGBERG JAN
Published: May 2007

The extrachromosomal rDNA molecules from a number of Tetrahymena strains wered racterized by restriction enzyme mapping using three different restriction enzymes combined with gel blotting and hybridization analysis. Strains from four out of six recently described species were found to contain an intron in the 26s rRNA coding region. The evolutionary relationship among the species of the T. pyriformis complex was examined on the basis of the rDNA maps with emphasis on similarities between two of the new species and the widely studied T. thermophila and T. pigmentosa. Examination of a large number of T. pigmentosa strains showed this species to exhibit an unusual polymorphism with respect to its rDNA. It is suggested that recombinational cross‐over events play a role in the formation of new rDNA alleles in this species.
A New Pathogen, Microsporidium itiiti n. sp. (Microsporida), from the Argentine Stem Weevil, Listronotus bonariensis (Coleoptera, Curculionidae)1
Authors: MALONE LOUISE A.
Published: May 2007

A new species of microsporidium (phylum Microspora) infecting the Argentine stem weevil, Listronotus bonariensis (Kuschel. 1955), is described on the basis of light and electron microscope observations. It has the following characteristics: nuclei always isolated; meronts spherical and sporonts ribbon‐shaped, with variable numbers of nuclei; sporogony within a vacuole which is bounded by a thin membrane that usually breaks down before uninucleate spores mature; occasionally parts of the membrane remain so that clusters of variable numbers of spores may be seen in light microscopic preparations. Spores measure 2.5 × 1.4 μm (fresh) and development occurs mainly in the midgut, but also in the epidermis, fat body, muscle, and ovaries.
Immunoblot Analysis of Exospore Polypeptides from Some Entomophilic Microsporidia12
Authors: IRBY W. S. , HUANG Y. S. , KAWANISHI C. Y. , BROOKS W. M.
Published: May 2007

ABSTRACT. Immunological relationships between genera and species of microsporidia were examined by immunoblot analysis. Exospore polypeptides from two Nosema spp., three Vairimorpha spp., and two undescribed Vairimorpha‐like isolates were analyzed. Gel electrophoresis and immunoblot analysis revealed that a variety of polypeptides, mostly between 15,000 and 90,000 molecular weight, are present on the exospore. The three Vairimorpha spp. are closely related immunologically to each other, but less so to the two undescribed Vairimorpha‐like isolates. The two Nosema spp. are immunologically distant from each other and from the Vairimorpha spp. Indirect evidence, however, indicated that many internal spore polypeptides present in both genera are similar. Cross‐reactivity between exospore polypeptides from entomophilic microsporidia and antisera to a mammalian microsporidium, Encephalitozoon cuniculi, was very limited. These results indicate that immunoblot analysis of exospore polypeptides may be employed to investigate the interrelatedness of microsporidian species, and that exospore polypeptides of some microsporidia are sufficiently diverse to be of immunodiagnostic value.
Alternative Processing of Sequences During Macronuclear Development in Tetrahymena thermophila1
Authors: WHITE THEODORE C. , ALLEN SALLY LYMAN
Published: May 2007

ABSTRACT. DNA is eliminated during development of the somatic MACronucleus from the germinal MICronucleus in the ciliated protozoan, Tetrahymena thermophila. Facultatively persistent sequences are a class of sequences that persist in the MAC DNA of some cell lines but are eliminated from the MAC DNA of other cell lines. One cloned MAC fragment contains a persistent sequence as well as sequences normally retained in the MAC. When this cloned fragment was used to construct MAC restriction maps of this region in cell lines whose MAC DNAs do, or do not, contain the persistent sequence, extensive variation in the map flanking this region was observed. The different DNA rearrangements of this MIC segment are epigenetically determined during or soon after MAC development. Moreover, different rearrangements may occur among the 45 copies of this MIC segment as a MAC is formed, resulting in polymorphisms that are later resolved by phenotypic assortment.