bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphogenesis in Conchophthirus curtus: a Study of the Morphological Events Associated with Binary Fission1
Authors: ANTIPA GREGORY A. , HATZIDIMITRIOU GEORGE 
Published: May 2007

ABSTRACTMorphogenesis in Conchophthirus curtus has been investigated by the use of protargol silver impregnation supplemented by selective use of scanning electron microscopy. Events are assigned to nine sequential stages; the last, stage 9, which involves maturation of the somatic ciliature and infraciliature as well as the final development of the buccal cavities of both proter and opisthe, occurs following cytokinesis. Stomatogenesis involves both the parental haplokinety and the deep kinetosomal unit (DKU). In perhaps a unique phenomenon, phylogenetically, the ciliated parental haplokinety forms the early oral primordium of the opisthe and is replaced in the proter by the DKU. The DKU then acts as a formative center for new kinetosomes that migrate into the developing opisthe primordium. Late in the process, the haplokinetal primordia of both proter and opisthe give rise to their respective DKU's. Some events of nuclear activity and somatic development are also described. The high degree of structural differentiation of this ciliate has provided the opportunity to examine temporal relationships during morphogenesis. We have found that somatic, buccal, and nuclear events proceed in a tightly coupled sequence. Hence, somatic and nuclear development can be directly correlated with the nine stages of stomatogenesis.
The Cortical Morphogenetic Cycle Associated with Cell Division in Diophrys Dujardin, 1841 (Ciliophora, Hypotrichida)1
Authors: HILL BRUCE E. 
Published: May 2007

ABSTRACTMorphogenesis of cell division was investigated in Diophrys scutum, D. oligothrix, and D. appendiculata utilizing both light microscopy of living and stained specimens and SEM of preserved specimens. The cortical morphogenetic pattern of Diophrys is similar to that of other members of the family Euplotidae. The opisthe oral primordium, which develops in a subsurface pouch, forms posterior to the parental buccal cavity. The proter inherits the parental adoral zone of membranelles (AZM) apparently unchanged. The endoral membrane forms to the right of the posterior end of the AZM in the proter, in association with the developing AZM in the opisthe. The paroral cirrus and membrane develop from a single streak that first appears along the right edge of the buccal cavity in the proter to the right of the developing buccal structures of the opisthe. Frontal and transverse cirri develop in both proter and opisthe from five separate cirral primordia that form to the right of the buccal cavity. Left marginal cirri do not develop in association with the corresponding parental structures. Kinetosomes formed within the opisthe oral primordium, or kinetosomes that were part of any parental ciliary structure, do not appear to become part of any developing paroral structures, frontal, transverse, or left marginal cirri. Speciation within the genus Diophrys and evolution of the family Euplotidae as they relate to the morphogenesis of cortical structure are discussed.
Species of Eimeria in Nonepithelial Sites1
Authors: OVERSTREET ROBIN M. 
Published: May 2007

ABSTRACTIn a few homoiothermic host species, Eimeria spp. in a schizogonic stage, a gamogonic stage, or as resting sporozoites infect nonepithelial tissues. However, epithelium serves as a critical site in the cycle of these and all other species known from warm‐blooded hosts. Eimeria funduli, infecting at least four different killifishes, undergoes both schizogony and gamogony in non‐epithelial hepatic and pancreatic cells and requires an invertebrate host to complete its cycle. Oocysts are not released from the living fish into the environment. The cycle for this species, or aspects of it, may exemplify those found in several piscine species infecting nonepithelial (and possibly epithelial) cells. Eimeriu funduli differs from most species of Eimeria infecting homoiotherms in other respects, some of which may also characterize traits for piscine and other poikilotherm eimerians in general. Endogenous development is affected by temperature and host‐age, sporogony occurs in the host, and infections occur in several related fishes. The presence of an intermediate host in at least E. funduli and the presence of sporozoites in macrophages of several eimerians of homoiotherms, as well as other features, suggest a closer relationship between eimeriids and Lankesterella, Schellackia, and even the Haemosporina than previously assumed.
The Sarcocystidae: Sarcocystis, Frenkelia, Toxoplasma, Besnoitia, Hammondia, and Cystoisospora1
Authors: SMITH DONALD D. 
Published: May 2007

ABSTRACTMembers of the family Sarcocystidae, as defined by Frenkel, have had a complicated history, principally due to the existence of both coccidial and cystic stages. This formerly clandestine relationship resulted in dual or partial designations of nomenclature for individual species. The problem was further compounded by the obligatory heteroxeny of several of the genera, making it impossible to transmit the parasites from one individual to another of a single host. As a result, oocysts similar in appearance, though from hosts separated taxonomically up to the familial level, were sometimes considered to be identical. Discoveries within the last decade have generated much interest and some understanding. Current studies of these and other coccidia should emphasize complete cyclical transmissions with cognizance of potential heteroxeny with the production of tissue cysts in intermediate hosts.
Coccidian Taxonomy and Nomenclature1
Authors: FAYER RONALD 
Published: May 2007

ABSTRACTProblems of the taxonomy and, especially, of the nomenclature of various species of coccidia of direct importance to humans are further discussed. The diversity of host potential and site selection is also mentioned, with the prediction that, hopefully, our knowledge will be much greater 15 years from now than it presently is.
A Simple, Highly Efficient Plating Method for Trypanosomatids1
Authors: TANURI AMILCAR , DE ANDRADE PAULO P. , DE ALMEIDA DARCY F. 
Published: May 2007

ABSTRACTA simple technique for plating trypanosomatids includes use of plates with lower agar concentrations than those usually prescribed for plating bacteria and a simple system to prevent dehydration due to the long incubation time needed for formation of visible colonies. Consistently high plating efficiency was thus achieved. Colonies from Herpetomonas samuelpessoai and Crithidia deanei were clearly distinguishable from each other; their individual characteristics varied with plating conditions.
Rapid In Vitro Prescreen for Chelators as Potential Trypanocides Based on Growth of Crithidia fasciculata1
Authors: SHAPIRO ANNA , HUTNER S. H. , KATZ LILLIAN , BACCHI C. J. 
Published: May 2007

ABSTRACTA rapid in vitro prescreen for Fe‐binding chelators has been developed with growth of Crithidia fasciculata and the sparing of its heme requirement in a defined medium as a test system. The prescreen functions as an index of chelator‐mediated Fe transport and as an index of growth inhibition, presumably by the interference with Fe and/or heme metabolism at intracellular chelatable sites. Of 161 chelators examined, 84 were active heme‐sparers; 32 of these inhibited growth at low chelator concentrations. Twenty‐eight other chelators inhibited growth and another 49 were inactive. Such chelating activity directed at Fe and heme targets in hemoflagellates may provide leads for chemotherapy.
The Surface Charge of Tritrichomonas foetus
Authors: FILHO FERNANDO COSTA E SILVA , ELIAS CEZAR ANTONIO , DE SOUZA WANDERLEY 
Published: May 2007

ABSTRACTThe surface charge of Tritrichomonas foetus was evaluated by means of the binding of colloidal iron hydroxide particles at pH 1.8 and cationized ferritin particles at pH 7.2 to the cell surface, as visualized by electron microscopy and by direct measurements of the electrophoretic mobility (EPM), of cells suspended in solutions of different ionic strength and pH. At pH 7.2, T. foetus has a negative surface charge with a mean EPM of −1.03 μmμs−1μV−1μcm. At lower pH, there is a decrease in the negative surface charge with an isoelectric point at pH 1.2. At higher pH (> 9.0), there is an increase in the surface charge reaching an EPM of −2.5 μmμs−1μV−1μcm. These results indicate that the surface of T. foetus contains both negatively and positively charged dissociating groups. Binding of colloidal iron hydroxide and cationized ferritin particles throughout the cell surface of the protozoon was observed. Treatment of T. foetus with neuraminidase or trypsin reduced significantly the EPM of the cells. Enzyme‐treated cells recovered their normal EPM when incubated for 6 h in fresh culture medium by a process that is inhibited by puromycin.
Growth of Isolated Amastigotes of Trypanosoma cruzi in Cell‐Free Medium1
Authors: VILLALTA FERNANDO , KIERSZENBAUM FELIPE 
Published: May 2007

ABSTRACTAmastigotes of Trypanosoma cruzi were purified from overlays of infected Vero cell cultures by centrifugation over a discontinuous gradient of metrizamide. Pure amastigote preparations were usually recovered from the pellet under the layer of specific gravity 1.086. The isolated amastigotes grew in cell‐free ML‐15HA medium. Growth rate for the different strains of T. cruzi were in the order Y > Tulahuan > CL. The generation time of amastigotes in ML‐15HA medium was 16.8, 18.0, and 26.4 h for the Y, Tulahuen, and CL strains, respectively, in the presence of 5% CO2) and 16.8, 31.2, and 36.4 h, respectively, in the absence of CO2. Intracellular amastigotes did not differ ultrastructurally from amastigotes from either the density‐gradient fractionation or culture in cell‐free medium.
Further Studies on Haemogregarina bigemina Laveran & Mesnil, the Marine Fish Blennius pholis L., and the Isopod Gnathia maxillaris Montagu1
Authors: DAVIES ANGELA J. 
Published: May 2007

ABSTRACTHaemogregarina bigemina is redescribed from the blood of the marine fish Blennius pholis, and stages presumed to be those of the haemogregarine are recorded from the hematophagous praniza larva of the isopod Gnathia maxillaris. At College Rocks, Aberystwyth, Wales, the main study area, a high incidence of infection occurred in B. pholis. No exoerythrocytic stages were observed in these fish, nor was sexual dimorphism of the gametocyte evident. As in an earlier study, ecological evidence favored transmission by G. maxillaris rather than by leeches. Gametocytes, syzygy, oocysts, sporoblasts, and sporozoites were identified in the anterior hindgut of the isopod. The stages observed in G. maxillaris are compared with those of other haemogregarines described from the digestive tract of leeches. Mention is made of an intraleucocytic haemogregarine of another fish, Crenilabrus melops.
Development of Ox‐Coyote Cycle of Sarcocystis cruzi1
Authors: DUBEY J. P. 
Published: May 2007

ABSTRACTThe ox‐coyote cycle of Sarcocystis cruzi was studied by killing 38 calves between 4 and 153 days postinoculation (DPI) with 55 × 103‐5 × 108 sporocysts from the intestines of coyotes. At 4 DPI, a zoite was found within the lumen of a mesenteric lymph node artery. At 7 DPI, zoites were found in mononuclear cells and in endothelial cells in mesenteric arteries. First generation meronts (41.0 × 17.5 μm in diameter) occurred 7–26 DPI in mesenteric lymph nodes. At 19–46 DPI, second generation meronts occurred in kidneys, muscles, and other tissues: renal meronts were 19.6 × 11.0 μm, and intramuscular meronts were 25.0 × 11.1 μm. Merozoites were found in the peripheral blood 17 DPI and later at 24–46 DPI. They divided by endodyogeny in mononuclear cells. Sarcocysts were seen first in the heart at 45 DPI and contained one or two metrocytes. At 55 DPI, sarcocysts containing only metrocytes were found in striated muscles, heart, and in smooth muscles of the urinary bladder, rumen, omasum, abomasum, and small intestine. At 67, 87, 112, and 153 DPI, sarcocysts were found only in striated muscles and in the heart. At 67 DPI, sarcocysts were up to 360 μm long. They contained only metrocytes and were not infective to the dog. At 86 DPI, sarcocysts contained mostly bradyzoites, a few metrocytes, and were infective to a coyote. The thin‐walled sarcocysts grew to a maximum length of 800 μm and contained bradyzoites that were 10.9 × 3.0 μm. At 90 DPI, two mature sarcocysts were found in 2 of 73 sections of brain and spinal cord; hundreds of sarcocysts were present in sections of tongue and heart of this calf. Gametogony occurred in the small intestine of the coyote. Macro‐and microgamonts were found in goblet cells of the small intestines of coyotes 6 h after the ingestion of infected meat. Microgamonts were few and contained 3–11 slender gametes. Oocysts were seen at 12 h and sporulation was completed 9 DPI. The prepatent period in the coyote was 8 days. The ox‐coyote cycle is compared with ox‐dog cycle.
Esterase Variants in Four Species of the Paramecium aurelia Complex1
Authors: ALLEN SALLY LYMAN , LAU ELIZABETH T. , NERAD THOMAS A. , RUSHFORD CAROLINE L. 
Published: May 2007

ABSTRACTOne hundred eighty‐eight stocks of Paramecium primaurelia, P. biaurelia, P. tetraurelia, and P. octaurelia were grown axenically and tested for five esterases, visualized by starch gel electrophoresis, in a search for variant stocks. The five esterases can be distinguished on the bases of their substrate specificity, sensitivity to an inhibitor, and response to different growth conditions. This paper addresses the nature of the electrophoretic change in mobility of the variant stocks in order that species relationships can be more accurately assessed. Crosses carried out in all four species show that single genes determine the differences in mobility between variant and common subtypes. Extracts of variant stocks that gave similar patterns were run against each other, tested for their sensitivity to the inhibitor, and the pattern was compared to that found in extracts of stocks with variant and common subtypes in other species. The majority of the variants in P. primaurelia, P. tetraurelia, and P. octaurelia show an electrophoretic mobility characteristic of a common subtype, or a variant, in another species. The same proportion of variant subtypes as common subtypes have mobilities similar to esterase subtypes found in other species. Of the four species examined in this paper, P. tetraurelia and P. octaurelia appear to be most closely related on the basis of shared esterase subtypes. In P. biaurelia the mobilities of most of the variants are unique, as are the common esterase subtypes in this species. P. biaurelia stands out as having the greatest number of esterase subtypes, with very few of them homologous to subtypes found in other species. This observation supports the idea of greater diversification of stocks within P. biaurelia than for the other three species.
The Ultrastructure of Specimens of Paramecium multimicronucleatum Impregnated with Silver by the Fernández‐Galiano Method1
Authors: TELLEZ CARMEN , SMALL EUGENE B. , CORLISS JOHN O. , MAUGEL T. K. 
Published: May 2007

ABSTRACTTransmission and scanning electron microscopy of specimens of Paramecium multimicronucleatum treated with the Rio‐Hortega silver‐impregnation method as modified by Fernández‐Galiano demonstrate that considerable deposition of silver occurs around the kinetosomes, especially at the level of the basal plate and also at the proximal end of the kinetosome. In addition, silver is heavily deposited within the kinetodesmal fibers, in the fibrous matrix that surrounds the postciliary and transverse microtubules, in the connective structures observed between the two kinetosomes of a pair and between the kinetodesmal fiber and the anterior kinetosome, and in the trichocysts. Differences and similarities in sites of deposit when other methods of silver impregnation are employed are discussed and the particular value of the present technique in studies of ciliate systematics and phytogeny is stressed.
Development of Eimeria funduli in Fundulus heteroclitus1
Authors: UPTON STEVE J. , DUSZYNSKI DONALD W. 
Published: May 2007

ABSTRACTLaboratory‐reared Fundulus grandis and F. heteroclitus were experimentally infected with Eimeria funduli by being fed Palaemonetes pugio (grass shrimp) collected from endemic areas. Histological sections were made of heart, liver, hepatopancreas, spleen, gall bladder, kidney, intestine, peri‐intestinal fat, reproductive organs, and brain from F. grandis sacrificed at 1, 2, 6, 12, 18, and 24 h and from F. heteroclitus at 5, 6, 9, 14, 19, 24, 29, 34, 39, and 44 days after consuming naturally infected shrimp. We first found merogonous stages at day 9 postinfection (p.i.). No developmental stages of the parasite could be positively identified in the tissues of experimentally infected fish prior to day 9 p.i. Mature meronts were found 14 days p.i. The majority contained 8–16 (mean, 13) merozoites, but a few meronts had 18–26 (22) merozoites. Gamonts first appeared on day 14, were mature by day 19, and fertilization was completed by day 24 p.i. After sporoblast formation, sporopodia appeared during sporocyst wall formation, between days 24 and 29 p.i. Sporozoite formation was completed by day 44 p.i. in most sporocysts. Most endogenous stages occurred in hepatocytes; however, pancreatic and spleen cells were sometimes infected with gamonts.
The Life Cycle of Trypanoplasma bullocki (Zoomastigophorea: Kinetoplastida)1
Authors: BURRESON EUGENE M. 
Published: May 2007

ABSTRACTThe leech Calliobdella vivida (Verrill) is the vector of Trypanoplasma bullocki. At 10°C, infective‐stage flagellates were first present in the leech's proboscis sheath five days after feeding. At 5°C, infective‐stage flagellates were not present in the leech's proboscis sheath until 10 days after feeding, but at 20°C, flagellates were located there as early as 24 h after feeding. Infected leeches retained flagellates through three subsequent feeds on uninfected fish. When flagellates were first observed in hogchoker, Trinectes maculatus (Bloch & Schneider), they were much larger than infective stages from the leech. Average flagellate length then decreased during early acute phase, but gradually increased thereafter. Peak parasitemia was greater in a hogchoker inoculated by only one leech but held at colder temperature than in a hogchoker inoculated by 45 leeches, suggesting that temperature may be more important than inoculum in determining peak parasitemia. Cell division in the fish host is described. SEM studies of fish blood flagellates revealed a pre‐oral ridge and a cytostome.
The Biology and Pathogenicity of a Recent Field Isolate of Eimeria praecox Johnson, 1930
Authors: GORE THOMAS C. , LONG PETER L. 
Published: May 2007

ABSTRACTA recent isolate of Eimeria praecox, strain G, was obtained from Georgia and purified. Studies of the life history, pathogenicity, and cross‐immunity of the isolate were conducted to verify its identity. In inoculated three‐week‐old chickens, the occurrence of merogony and gametogony was limited to the superficial epithelium of the upper intestine. Oocysts, 23 × 19.5 äm, with a shape index of 1.17 were first observed 83 h after inoculation. Mortality and morbidity were not observed in any of the experimental birds. However, there was a positive correlation between dose of oocysts, reduced weight gain, and the incidence of exudative diathesis. These studies showed that E. praecox depresses weight gains in chickens and may be of economic importance. Although complete immunity to avian coccidiosis is believed to be species specific, chickens immune to E. praecox (G) or E. acervulina had a degree of cross‐immunity to a heterologous challenge. Electrophoretic analysis of glucose phosphate isomerase and lactate dehydrogenase prepared from the European strain of E. praecox and E. praecox (G) showed no differences, confirming the identity of the isolate as E. praecox.
Serum Agglutination and Immunoglobulin Levels of Mice Infected with Naegleria fowleri1
Authors: HAGGERTY R. M. , JOHN D. T. 
Published: May 2007

ABSTRACTAgglutinins were not detected in sera from mice given one, two, or three intranasal (i.n.) inoculations or a single intravenous (i.v.) inoculation of trophozoites of Naegleria fowleri. However, agglutinins were produced following second and third i.v. inoculations. Serum immunoglobulin levels increased in both i.n.‐ and i.v.‐inoculated mice. IgG and IgM increased substantially more for i.v.‐inoculated mice. IgA levels increased more consistently for i.n.‐inoculated mice.
Electrophoretic Isoenzyme Patterns of Entamoeba histolytica and Entamoeba chattoni in a Primate Survey1
Authors: SARGEAUNT P. G. , WILLIAMS J. E. , JONES D. M. 
Published: May 2007

ABSTRACTStocks of Entamoeba histolytica grown in a monoxenic culture system from the feces of nonhuman primates are compared with the eleven zymodemes of E. histolytica so far demonstrated from man. In a similar fashion, Entamoeba chattoni has also been grown and identified. Both E. histolytica and E. chattoni have been demonstrated in keepers of the primate collections. Comparisons have been made using the electrophoretic patterns of three enzymes: glucosephosphate isomerase [(GPI) E.C.5.3.1.9], phosphoglucomutase [(PGM) E.C.2.7.5.1], and L‐malate—NADP+ oxidoreductase (oxaloacetate‐decarboxylating) [(ME) E.C. 1.1.1.40]. Enzyme patterns of E. histolytica from the apes were found to be identical with three of those already demonstrated from man. The enzyme pattern of E. chattoni was distinctly different from that of any of the E. histolytica zymodemes. Other protozoa found in the single fecal sample examined from each subject are also listed.
A New Species of Eimeria from the Golden‐Mantled Ground Squirrel, Spermophilus lateralis, in Northern Colorado
Authors: TORBETT BRUCE E. , MARQUARDT WILLIAM C. , CAREY ANDREW C. 
Published: May 2007

ABSTRACTOocysts of Eimeria morainensis n. sp. are described from the golden‐mantled ground squirrel, Spermophilus lateralis. in Northern Colorado. The oocysts of E. morainensis are double‐walled and subspherical, 20.3 × 19.8 (18.7–26.2 × 17.5–21.2) μm; and the sporocysts are ellipsoid, 12.1 × 6.9 (8.7–13.7 × 6.2–8.7) μm. Oocyst residuum and micropyle are absent, but a polar granule is present. Sporocyst residuum and Stieda body are present. Differences in oocyst characteristics provide the basis for recognition of this new species of Eimeria.
Distribution of Acantharia in the Western Sargasso Sea in Correspondence with “Thermal Fronts”1
Authors: BOTTAZZI ELSA MASSERA , ANDREOLI M. GABRIELLA 
Published: May 2007

ABSTRACTA study of plankton samples collected in the Western Sargasso Sea during nine cruises has shown discontinuity between samples from different latitudes as regards their percentage, abundance, and number of species of Acantharia. Limits separating zones rich in Acantharia from those poor in Acantharia were singled out. The latitude at which the difference in abundance occurs can vary. This is in accord with differences in primary production, phytoplankton, and mesopelagic fishes noted by other workers who believe that the points of these faunal changes correspond to a temperature change indicated as “thermal fronts.”