bluuebunny/crossref_metadata_2025_split huggingface dataset:
Atoxoplasma Garnham, 1950, as a synonym for Lankesterella Labbé, 1899. Its life cycle in the English sparrow (Passer domesticus domesticus, Linn.)
Authors: LAINSON R. 
Published: May 2007

SYNOPSIS. All of 99 adult English house‐sparrows, examined in the St. Albans area of Hertfordshire, England, were found to be infected with the organism previously defined by Garnham (1950) as Atoxoplasma. Young birds were found to become infected while still in the nests and as early as 6 days after hatching; there was no evidence to suggest that the parasite was transmitted through the egg. Within a few weeks of leaving the nests, all of 150 fledgling sparrows examined were heavily infected and several trapped birds died from massive infections.All stages of schizogony were found in the lymphoid‐macrophage cells of the spleen, bone marrow and liver of these birds; later, as the schizogonic cycle abated, gametocytes developed in similar cells of the liver, lungs and kidney. These gametocytes are of the Eimeria type: the zygote nucleus divides to produce an asporous and polyzoic oocyst containing a large number of sporozoites, and after the rupture of the oocyst these sporozoites invade the lymphocytes and monocytes of the peripheral blood.Transmission of the parasite in the sparrow is thought to take place after the ingestion of infected mites (Dermanyssus gallinae) by the young birds in the nests: unchanged sporozoites were found in smears of these mites that had been fed on infected sparrows. Transmission experiments were impossible due to the complete lack of clean sparrows.The taxonomic status of Atoxoplasma is discussed. The type of life cycle and the production of asporous, polyzoic oocysts indicate inclusion of this parasite in the Order Coccidiida, Family Eimeriidae, Sub‐Family Cryptosporidiinae Hoare, 1933. After comparison of the two genera, the author concludes that Atoxoplasma must be regarded as a synonym for Lankesterella. Some previously described species of Atoxoplasma are, therefore, transferred to the genus Lankesterella.The name Lankesterella garnhami nov. sp., is proposed for the parasite in the English sparrow (Passer domesticus domesticus), and Lankesterella serini nov. sp., for that in the canary (Serinus canarius).
Submicroscopical Aspects of Schizotrypanum cruzi in Thin Sections of Tissue Culture Forms*
Authors: MEYER H. , QUEIROGA L. T. 
Published: May 2007

SYNOPSIS.In order to study the blepharoplast‐kinetoplast region in the adult form of Schizotrypanum cruzi thin sections of this form, obtained in tissue cultures, have been examined with the electron microscope. It has been seen that the kinetoplast is contained in a large spherical, vacuole‐like space, in hich its osmiophilic mass is more dispersed than in the leishmania and crithidia forms, where it is contained in a rectangular, almost linear space. The basal body of the flagellum has been found at the margin of the vacuole, although separated from it. A group of striae in parallel array has been found with regularity in all the trypanosome forms, similar to the structures of the parabasal body in other protozoa, or to the Golgi apparatus of metazoan cells. The significance of this structure for the parasite is discussed.
The Electron Microscopy of Sarcocystis miescheriana Kuhn 1865
Authors: LUDVIK JIRI 
Published: May 2007

SYNOPSIS.Ultrathin sections of Sarcocystis miescheriana were studied in the electron microscope. The banana‐shaped body of the parasite shows a polar ring with a conoid at the anterior conical pole similar to that of S. tenella. Twenty‐two fine fibrils arise from the polar ring passing radially in the pellicle. The anterior third of the cell is filled with sarconemes converging in the conoid. Behind their ends in the center of the cell large osmiophilic central granules can be seen. A large nucleus in the posterior third with a double membrane contains small chromatin granules situated peripherally. Around the nucleus and in the posterior part of the body numerous small vacuoles with osmiophilic walls, as well as mitochondria are observed. The pellicle consists of 2 layers. On the control preparations cytochemical reactions on ribonucleic acid, deoxyribonucleic acid, polysaccharides, glycogen, volutin and fats were performed. The surface of the cyst is covered by a thin layer showing a honey‐comb structure giving rise to a great amount of parallel finger‐like villi surrounding the cyst on all sides. The villi contain many very fine double‐fibrils ending at the bases of villi in the finely granulated plasmatic interior cyst wall which forms also the septa of compartments. The functions of the observed organelles and structures are discussed.
Electron Microscopy of Pinocytosis and Food Vacuoles in Pelomyxa*
Authors: ROTH L. E. 
Published: May 2007

SYNOPSIS.Food vacuoles have been studied in various stages of the digestive process in cultures of Pelomyxa carolinensis and P. illinoisensis after feeding Tetrahymena and Paramecium. The vacuole wall formed immediately after capture of the food organism may be only 100 m/i thick. The changes observed in the food organisms indicate that first the membranes of the pellicle are ruptured, then mitochondria, cytoplasmic matrix, and nucleus are attacked; cilia and trichocysts are more resistant. The food vacuole membrane is involved first in the removal of water from the vacuole, then in transfer of cytoplasmic fluid into the vacuole, and finally in removal of digestion products from ihe vacuole by pinocyt. Vesicles which have been derived from the plasnulf—a b pinocytosis have been observed. They characteristically have a non‐turgid, non‐spherical appearance when located deep m the cytoplasm and are stainable with phosphotungstic acid. Pinocytosis and the function of food vacuole membranes are discussed. It is concluded that at leait two factors contribute to the benefits derived by amoebae from pinocytosis: (1) modification of the plasmalemma membrane near the time when it becomes the pinocytic vesicle membrane, and (2) increased surface area for diffusion.
The Effect of Physical and Chemical Agents on the Oocyst of Eimeria zurnii (Protozoa, Coccidia)*
Authors: MARQUARDT WILLIAM C. , SENGER CLYDE M. , SEGHETTI LEE 
Published: May 2007

SYNOPSIS.A study was made of the effects of solar radiation, temperature, relative humidity, centrifugation, oxygen, pH, and certain chemical agents on the sporulation of oocysts of Eimeria zurnii of cattle. Of various chemical agents and bactericides tested, only HgCl2 exhibited a high level of activity against unsporulated oocysts. Extreme pH values of 1 and 13 did not alter sporulation. Oocysts required at least 10% of the normal amount of oxygen to sporulate at a normal rate. Physical factors found to be lethal for E. zurnii were: sunlight for as short a time as 4 hours, drying at 25% or less relative humidity, and freezing below about ‐7° C. Survival was directly proportional to relative humidity, but within the limits of the observations reported here, there was no correlation with time or temperature. Normal sporulation occurred from about 8° up to 32.5° C. Below 12° the time required for sporulation was exceedingly long, and at 35° sporulation was morphologically abnormal. The optimal temperature for sporulation was about 30° at which temperature some organisms completed the process in 23 hours. Fifty % of the oocysts required 65 hours to begin sporulating at 20° and 36 hours at 25° C.
Two New Species of Coccidia of the Coypu
Authors: PRASAD H. 
Published: May 2007

SYNOPSIS.The literature on the coccidia of the coypu Myo‐ castor coypus Mol is reviewed. Four species of Eimeria have been described in these animals: E. seideli, E. myopotami, E. pellucida and E. coypi. The description of E. coypi is similar to E. myopotami in every respect, except for a little variation in size of the sporocyst It is therefore proposed to consider this species synonymous with E. myopotami, Two new species of Eimeria, E. myocastori sp. now and E. nutriae sp. nov. are now described from the coypu, naturalised n England in England.
The Buccal Organelles in Paramecium aurelia During Fission and Conjugation, with Special Reference to the Kinetosomes
Authors: PORTER E. DWAIN 
Published: May 2007

SYNOPSIS.Stomatogenesis in Paramecium aurelia is shown to involve the lower kineties of the right vestibular wall, the endoral membrane and perhaps the quadrulus. The anarchic field for the new buccal organelles is formed by granules produced from somatic kinetosomes of the right vestibular wall. The endoral membrane becomes incorporated into the buccal anlage and probably regulates orientation and development of the new organelles. A production of heretofore unobserved buccal kinetosomes from the quadrulus is described and it is suggested that these may form the new endoral membrane for the proter.During conjugation the infraciliature dedifferentiates in the area of fusion between the conjugants. The buccal organelles dedifferentiate at the time of pronucleus formation and transfer. It is suggested that dedifferentiation of structures in the fusion area is caused by a partial solation of the cortex in this area. The dedifferentiation of the buccal organelles results from the solation of the cytoplasm and the cortex of the paroral cone during pronucleus migration. The redifferentiation of the buccal organelles and somatic kinetosomes is suggested to be a recrystallization or gelation of the cortex with the structures re‐forming in their normal positions and not from an anarchic field as at fission.
Oxidative Assimilation of Acetate by Euglena. Carbon Balance and Effects of Ethanol*
Authors: DANFORTH WILLIAM F. 
Published: May 2007

Oxidative assimilation of acetate by Euglena gracilis was studied using methyl‐ and carboxyl‐labeled radioactive acetate. Of the total carbon utilized, 40% was oxidized to CO2 and 60% was assimilated; 20% of the CO2 produced was derived from the methyl carbon, and 80% from the car‐boxyl carbon of acetate. Seventy % of the carbon assimilated was derived from the methyl carbon and 30% from the carboxyl. The results suggest that assimilation involves decarboxylation of Krebs‐cycle oxalacetate and assimilation of the resulting pyruvate.In the presence of ethanol a greater proportion of the acetate carbon is assimilated, though the total acetate consumption is almost unchanged.
The Life Cycle and Incidence of Hepatozoon balfouri (Laveran, 1905) in Egyptian Jerboas (Jaculus spp.) and Mites (Haemolaelaps aegyptius Keegan, 1956)*
Authors: HOOGSTRAAL HARRY 
Published: May 2007

The incidence of Hepatozoon balfouri (Laveran, 1905) in examined populations of Egyptian jerboas was 41% in Jaculus j. jaculus, 21% in Jaculus o. orientalis, and nil in Allactaga tetradactyla. Infection in a few animals apparently less than 6 days old suggests the possibility of transplacental transmission. The cycle in erythrocytes and parenchyma cells of the liver is described; stages in liver are seldom seen in chronic infections. Blood of many other Egyptian rodents and insectivores was negative for H. balfouri.The sporogonic cycle in mites, Haemolaelaps aegyptius Keegan, 1956, fed on infected jerboas, resembles that of other typical Hepatozoon species. Sporocysts contain 6 to 16 (usually 12) sporozoites. Infection rates in experimental cultures of H. aegyptius varied greatly. Mites from only a single graphic area could be experimentally infected; in the same area, the infection rate in J. jaculus is significantly higher than elsewhere. Biological races of Haemolaelaps aegyptius, more or less refractive to H. balfouri infection, may exist. Large numbers of mites, lice, fleas, and ticks removed from infected jerboas were uninfected, as were numerous arthropods experimentally fed on infected jerboas.Owing to the presence of H. balfouri foci in widely differing ecological zones of North Africa and Sudan, different species of mites, and possibly of other arthropods, obviously transmit the infection; details of this likelihood require further investigation.
Cytology of Cold Induced Transformation of Octogenic Reproductive Cysts to Resting Cysts in Colpoda maupasi*
Authors: PADNOS MORTON 
Published: May 2007

SYNOPSIS. Octogenic reproductive cysts are transformed into resting cysts when returned to optimal temperature following prior exposure to cold (5°C) for at least 36 hours. In the cold, the reproductive process ceases and macronuclei revert to the interphase condition. Transformation to resting cysts is synchronous. Induced encystment is accompanied by excessive macronuclear extrusion and is associated with a loss in division potential, resulting in no division, or 1 or 2 divisions in the induced resting cyst.These observations support the hypothesis that exposure to cold during a critical period of the predivisional stage may alter reproductive protein synthesis and favor cyst protein synthesis. The extensive macronuclear extrusions associated with this transition suggest their biochemical involvement in the encystment process.
Deoxyribonucleic Acid Synthesis and Distribution During Growth and Amitosis of the Macronucleus of Euplotes
Authors: KIMBALL R. F. , PRESCOTT D. M. 
Published: May 2007

SYNOPSIS. Short sections of deoxyribonucleic acid (DNA) in the elongated macronucleus of Euplotes eurystomus were labeled by means of a short exposure to tritiated (H3‐) thymidine to follow by autoradiography the fate of the labeled DNA during amitotic reorganization of the macronucleus. During amitosis the radioactive DNA that was restricted during interphase to short sections of the nucleus is dispersed and becomes evenly distributed throughout each daughter macronucleus.Although the reorganization bands normally originate only at the ends of the macronucleus, additional bands can start at other places on the macronuclear surface. Bands of the same macronucleus originate with a high degree of synchrony. DNA synthesis is a constant feature of the rear zone of every reorganization band.
Cellular Responses to Thermal and Photo Stress I. Euglena and Chlamydomonas*
Authors: GROSS J. A. , JAHN T. L. 
Published: May 2007

SYNOPSIS. Euglena and Chlamydomonas were cultured in an organic medium in the dark and at several light intensities (15, 60 and 150 ft‐c) at temperatures from 20d̀ to 35d̀C. Below 32.5d̀, growth of Euglena was independent of light. Chlamydomonas was light dependent at all temperatures where growth occurred; there was no growth in the dark, at 15 ft‐c, or at temperatures above 32.5d̀. At 35d̀, growth of Euglena became inversely light dependent; the higher the illumination, the poorer the growth. Multinucleated, giant euglenas were found at 35d̀, a greater percent of abnormal cells appearing at the higher light intensities. Monsters were not observed in Chlamydomonas.To explain the growth‐inhibiting, monster‐inducing effect of elevated temperatures on Euglena, it is postulated that a dark‐formed thermosensitive protein, essential for normal cell division, is denatured. Light may increase the effect of heat on chlorophyll and the chloroplast, possibly by being converted to intraplastidic heat through the plastid carotenoids, thus having some indirect synergistic role in the phenomenon.
Comparative Excystation of Four Species of Poultry Coccidia
Authors: FARR MARION M. , DORAN DAVID J. 
Published: May 2007

SYNOPSIS. Examination of the crop, gizzard, and intestinal contents of chickens fed suspensions of either Eimeria acervulina or E. tenella oocysts and turkeys fed either E. meleagrimitis or E. gallopavonis oocysts indicated that, in all 4 species, (1) oocysts apparently remained unchanged while in the crop, (2) sporocysts were liberated from oocysts while the latter were passing through the gizzard, (3) sporozoites were activated and escaped from liberated sporocysts after they had reached the small intestine, and (4) sporozoites within intact oocysts in the crop, gizzard, and intestines were not activated.In vitro, trypsin 1–300 alone caused a small percentage of sporozoites to excyst from mechanically liberated sporocysts. The percentage of excystation increased greatly when trypsin was added to sodium taurocholate and increased even more when it was combined with chicken or turkey bile.The two duodenal species (E. acervulina and E. meleagrimitis) differed both in vivo and in vitro from the two cecal species (E. tenella and E. gallopavonis). The duodenal species excysted in less time and farther anteriorly in the small intestine than did the cecal species. In addition, sporozoites of the two cecal species survived much longer in media containing trypsin plus bile or sodium taurccholate than did those of the two duodenal species.
Axenic Cultivation of Trichomonas tenax, the Oral Flagellate of Man I. Establishment of Cultures
Authors: DIAMOND LOUIS S. , Bartgis I. Louise 
Published: May 2007

SYNOPSIS. A technique for the axenic cultivation of Trichomonas tenax, the oral flagellate of man, is presented. The medium employed consists of a nutrient broth supplemented with horse serum and a cell‐free extract of chick embryo. Three strains established in this medium have been maintained for 16, 23 and 48 months respectively.All the cultures were initiated with trichomonads grown in association with Trypanosoma cruzi. Attempts to establish axenic cultures with trichomonads obtained from xenic cultures containing a bacterial flora of unknown composition met with failure. This suggests that the successful cutcome of the process of axenization is to a certain extent dependent upon the type of organism(s) with which T. tenax is associated in culture. Furthermore, these findings may serve to explain earlier failures since not only were all of these attempts made with media lacking tissue extract supplements but all were made using bacteria‐trichomonad cultures as a source of trichomonads.
Polymorphic Properties of Tetrahymena patula During Growth in Axenic Culture*
Authors: STONE G. E. 
Published: May 2007

SYNOPSIS. The effects of temperature and pH on growth and polymorphism were studied. The dimorphic condition followed a cyclic nature associated with growth in axenic culture. During logarithmic growth the population consisted of 95–100% microstomes. Upon entering stationary phase the microstomes transformed into macrostomes. The percent microstomes which transformed into macrostomes was found to be affected by culture conditions. When grown at 25°C, pH 7.0, 50% of the population during stationary phase was macrostomes, whereas cultures grown at 25°, pH 7.4, showed 26% macrostomes during stationary phase. Hydrogen ion concentrations higher and lower than this value produced increasingly larger percent of macrostomes during stationary phase. At 20°C, pH 7.0, stationary phase, the population consisted of 100% macrostomes. Generally, those conditions which favored growth in axenic culture also favored the microstome during stationary phase.Large populations of microstomes were induced to transform into macrostomes by transferring a logarithmically growing culture from 25° to 20° or 15°C. Silver impregnated cells showed that the transformation from microstome to macrostome involved oral replacement.It was found that macrostomes, when placed in fresh medium, gave rise to two microstomes through cell division. A direct transformation from macrostome to microstome was not observed.
Variation of Cell and Nuclear Volume of Tetrahymena pyriformis with Three Parameters of Growth: Age of Culture, Age of Cell, and Generation Time*
Authors: SUMMERS L. G. 
Published: May 2007

SYNOPSIS. Cell volume and nuclear volume of Tetrahymena pyriformis strains HS and E, grown on a defined medium, were measured as a function of age of culture, age of cell and generation time. The volume of an “average” single cell between divisions was calculated for logarithmic phase cultures by using volume distributions and difference equations. Cell volume measurements were made by compressing the cells to known thickness and measuring the area from photomicrographs. The nuclear volume was determined from diameter measurements of the nucleus by assuming the shape of a sphere.The cell volume decreased from the lag phase to the logarithmic phase and reached a minimum at the end of the logarithmic phase. It increased again during the stationary phase. The nuclear volume also decreased from the lag to logarithmic phase, but continued to decrease in the stationary phase until it reached the nuclear volume of the daughter cell. The average single cell volume increased at a constant rate for 85% of the generation time, at which point the rate diminished to zero. The nuclear volume showed no increase until 35% of the generation time had passed. It then increased at an accelerated rate which diminished just before division. Both the average cell and nuclear volumes decreased with increase in temperature until the optimum temperature was reached, at which point they increased again. There were no appreciable differences in volume changes for cells grown on different media.
Phosphate, Purines and Pyrimidines as Excretory Products of Tetrahymena*
Authors: LEBOY PHOEBE S. , OLINE SYLVIA G. , CONNER ROBERT L. 
Published: May 2007

SYNOPSIS. Tetrahymena pyriformis strain W, incubated for 3 hours in a salts‐PO4 medium, showed a net loss of phosphate from the cell. This loss of phosphate was accompanied by release of material having an absorption maximum at 250–260 nvi. The u.v.‐absorbing material contained hypoxanthine as well as a pyrimidine component.The release of hypoxanthine was consistent with an absence of detectable xanthine oxidase activity in Tetrahymena homogenates. Studies with homogenates indicated that hypoxanthine formation was paralleled by the formation of perchloric acid‐soluble material absorbing at 250 mμ, suggesting the degradation of nucleic acid.While glucose diminished the extent of phosphate and hypoxanthine loss from intact cells, the addition of iodoacetic acid (IAA) resulted in increased losses, as well as release of pentose into the medium. Since IAA did not influence the amount of acid‐soluble material formed by homogenates, it is suggested that the effects of glucose and IAA on the extent of excretion represent alterations in the ability of the cells to utilize nucleic acid degradation products in RXA synthesis.