bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isoenzyme and Total Protein Analysis by Agarose Isoelectric Focusing, and Taxonomy of the Genus Acanthamoeba
Authors: DE JONCKHEERE JOHAN F. 
Published: May 2007

ABSTRACTThirty 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

ABSTRACTThe 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

ABSTRACTEnzyme 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

ABSTRACTRats 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

ABSTRACTThe 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

ABSTRACTCalyptospora 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

ABSTRACTTrypanosoma 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

ABSTRACTOocysts 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

ABSTRACTDevelopmental 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

ABSTRACTThe 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

ABSTRACTSeveral 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

ABSTRACTAmastigotes 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.
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

ABSTRACTThe 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

ABSTRACTTwo 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

ABSTRACTThe 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

ABSTRACTThe 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.
Amebostomes of Naegleria fowleri1
Authors: John D. T. , Cole T. B. , Bruner R. A. 
Published: May 2007

ABSTRACTThe 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

ABSTRACTThe 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.