bluuebunny/crossref_metadata_2025_split huggingface dataset:
Serotype Expression and Transformation in Tetrahymena pyriformis
Authors: JUERGENSMEYER ELIZABETH B. 
Published: May 2007

SYNOPSIS. Of the 4 serotypes of Tetrahymena pyriformis, syngen 1, the H (expressed at 20–35 C) and T (expressed at 36–40 C) serotypes and their genetic bases have received the most attention. The present study describes the L and I serotypes, considers their transformations to and from the H serotype, and compares inter‐locus repression with allelic repression.The L serotype occurs below 20 C. No strain differences have been found between L antigens. However, the rate of transformation between H and L varies in the families, which can be ranked according to their preference for the H or L serotype. A3 is strongly L; D1 is strongly H; the other families form a continuum between these extremes. Preference for the H or L serotype is not correlated with the H allele present.Serotype differences may be hereditary, by the “dilution” test for hereditary differences. Altho the environment largely determines which serotype will be expressed, sublines can maintain established H and L serotypes for more than 40 fissions in a common environment. Crosses between H and L cells suggest macronuclear control of serotype determination and a cytoplasmic influence on macronuclear differentiation. Evidence for the cytoplasmic influence comes from both conjugants and nonconjugants.The I serotype is induced from the H serotype at room temperature by treatment with specific H antibodies, which are also necessary for I maintenance. The I serotype consists of a series of unstable serotypes which transform among themselves. Clones go thru an initial I type one day after induction and then diversify to express secondary types. The initial type and the secondary types are characteristic of the family but are not related to the H genotype. Family C1 lacks 2 secondary types found in other families studied.The differences between inter‐locus repression and allelic repression are marked. Altho inter‐locus repression is labile, all efforts to reverse allelic differentiations have failed. H heterozygotes maintained for long periods of time in the I or L state showed no reversal of H allelic repression.
Autoradiographic Studies of Uridine‐5‐H3 Uptake in Entamoeba histolytica in the CLG Medium1
Authors: SHARMA NARSINGH N. , ALBACH RICHARD A. , SHAFFER JAMES G. 
Published: May 2007

SYNOPSIS. Using uridine‐5‐H3, “long‐term” labeling experiments over a 72 hr growth cycle were done with E. histolytica strain K9 grown in CLG medium with penicillin‐inhibited Bacteroides. Autoradiographic analysis revealed that tritium occurs primarily in cytoplasm and rarely the nucleus of amebae. The most extensive cytoplasmic activity was observed during the initial 0–24 hr growth period of amebae as compared to later labeling periods.RNase or RNase followed by DNase extracted a large amount but not all label from amebae. These nucleases were least effective during the initial 24 hr period of growth. Thus it appears that tritium from uridine‐5‐H3 is not highly specific for RNA in amebae. However, the possibility that such label is associated with RNase‐resistant RNA cannot be ruled out. More recent cytochemical studies do indicate the presence of RNase‐resistant RNA in the cytoplasm of amebae. The activity found in penicillin‐inhibited Bacteroides after uridine‐5‐H3 labeling and their reaction to the various digestive procedures was similar to amebae at corresponding labeling periods. Therefore at least some of the RNase‐resistant material present in the cytoplasm of amebae may be derived from the ingested bacteria; this has been further found by appropriate experiments in which amebae were fed prelabeled bacteria.Nuclear activity when observed (always after 24 hrs growth) was associated either with the periphery of the nucleus and/or the endosome. It was not seen in the nuclear stroma. Some of this activity is RNase‐resistant, perhaps representing double or multi‐stranded RNA. It therefore appears that RNA is not distributed in the nuclear stroma in “long‐term” labeling experiments.
Growth of Trypanosoma cruzi in Human Heart Tissue Cells and Effects of Aminonucleoside of Puromycin, Trypacidin and Aminopterin
Authors: GUTTERIDGE W. E. , KNOWLER J. , COOMBES J. D. 
Published: May 2007

SYNOPSIS. Development of a suitable tissue cell system for the growth of T. cruzi required the production of infective metacyclic trypanosomes and tissues which these forms could infect. Human heart was selected from a range of serially‐cultured tissue cell lines as the most suitable for intracellular growth. Most metacyclic forms occurred when the growth medium had an initial pH of 7.2 and the cultures were gassed with 5% CO2/95% air before closure and then incubated at 33 C.During the first 4 days of incubation ∼ 10% of tissue cells in cultures were infected with 1–5 leishmanial forms of T. cruzi. During the next 4 days, the number of infected cells about doubled and many contained 10 or more leishmanias. The effects of drugs were studied on this 2nd 4‐day period of incubation. The aminonucleoside of puromycin affected growth of the intracellular but not the extracellular parasites whereas trypacidin had the opposite effect, inhibiting growth of the extracellular but not the intracellular forms. Aminopterin inhibited the growth of both extracellular and intracellular forms. The selective effects of the aminonucleoside of puromycin against intracellular forms might be due to it being metabolized by the host cells to a more active trypanocide.A method for isolating intracellular forms of T. cruzi from the tissue cells is described. Dihydrofolate reductase activity was found in these preparations and in similar preparations of the culture and blood forms. The reductase was sensitive to inhibition by aminopterin and a 2, 4‐diaminopyrimidine.
The Relation of Phosphate Metabolism to Oxidative Assimilation of Acetate by Euglena gracilis var. bacillaris. Effects of 2,4‐Dinitrophenol*
Authors: COLLYARD KENNETH J. , DANFORTH WILLIAM F. 
Published: May 2007

SYNOPSIS. Oxidative assimilation of acetate by Euglena gracilis var. bacillaris occurs without appreciable net transfer of inorganic phosphate between cells and medium. Low concentrations of the “uncoupling agent” 2,4‐dinitrophenol (2–5 μM, pH 5) stimulate acetate oxidation and inhibit acetate assimilation. These dinitrophenol concentrations have no measurable effect on edogenous respiration. Higher concentrations inhibit respiration on acetate, and still higher concentrations inhibit endogenous respiration.Dinitrophenol concentrations which stimulate acetate oxidation produce no measurable change in the total ATP content of the euglena cells. Higher concentrations (50–100 μM) cause progressive decrease in the ATP content.A hypothetical mechanism is proposed which accounts for the normal, constant oxidation‐assimilation ratio for acetate as the result of coupling of oxidative ATP synthesis with assimilatory ATP consumption. The data are consistent with this mechanism if it is additionally assumed that oxidation and assimilation of acetate occur in an intracellular “compartment” separated from other sources and sinks of ATP.
The Trichocysts of Chilomonas paramecium*
Authors: SCHUSTER FREDERICK L. 
Published: May 2007

SYNOPSIS Axenic cultures of Chilomonas paramecium were grown in media lacking a C‐source, resulting in breakdown in autophagosomal vesicles of large numbers of trichocysts. Return of the starved organisms to complete media was followed by a wave of trichocyst formation. Stages in the degeneration and subsequent reformation of trichocysts are described as well as attempted labeling of the developing organelles with 3H‐thymidine.A modification of the method of Anderson et al. (2) was used for isolating quantities of exploded trichocysts from Chilomonas. Attempts at isolation of the trichocyst in its coiled state were unsuccessful. Isolated trichocysts mounted on electron microscope grids were subjected to various types of enzymatic digestions.
Passive Immunization of Pigeons Against Trichomoniasis
Authors: KOCAN RICHARD M. 
Published: May 2007

SYNOPSIS Nonimmune homing pigeons Columba livia were infected with the Jones' Barn strain of Trichomonas gallinae and subsequently transfused with plasma from acute or chronically infected pigeons harboring one of 3 different strains of T. gallinae. The transfusions were either a single 2 ml dose given one day after inoculation or three 1 ml doses given 0, 5, and 10 days after inoculation. Plasma from pigeons harboring any of the 3 strains was capable of passively immunizing nonimmune birds. All birds which were immunized with plasma from infected pigeons survived until killed at the end of the test period and no visceral lesions were found on necropsy but trichomonads were present in the oropharynx. All controls (untreated or transfused with normal plasma) died of visceral trichomoniasis.Immune plasma produced some lysis of trichomonads in vitro, and inhibition of motility and vacuolization occurred in some of the non‐lysed organisms. The overall lytic activity in vitro affected less than 10% of the suspended trichomonads.
Incorporation of Radioactive Precursors into DNA and RNA of Plasmodium knowlesi in vitro
Authors: GUTTERIDGE W. E. , TRIGG P. I. 
Published: May 2007

SYNOPSIS. Cultures of the intra‐erythrocytic stages of Plasmodium knowlesi incubated in vitro utilized all the pre‐formed radioactive purines tested (adenine, adenosine, deoxvadenosine, guanine, guanosine and hypoxanthine) but none of the pyrimidines (thymine, thymidine, uracil, uridine, cytidine and deoxycytidine). They did, however, utilize the pyrimidine precursor orotic acid.All precursors analysed, including deoxyadenosine, were incorporated into both DNA and RNA (in the ratio of ∼1:3) but 19% was incorporated into other unidentified compounds. 3Hadenosine was incorporated into adenine and guanine residues of both DNA and RNA.No unambiguous evidence was obtained for any periodicity in the synthesis of DNA or RNA in our cultures, even tho cultures remained as synchronous in vitro as they are in vivo. An estimate is presented of the amount of DNA made during one cycle in vitro.
Some Myxosporida from Marine Fishes in South Florida1
Authors: IVERSEN E. S. , CHITTY N. , VAN METER N. 
Published: May 2007

SYNOPSIS. Myxosoma cephalis n. sp. is described from the brain meninges, gills, jaw bone, crop tissue and buccal cavity of Mugil cephalus Linnaeus (striped mullet) of south Florida. The fresh spore is subspherical in front view, lenticular in side view and averages 14.1 × 11.0 × 9.0 μ (length, width, thickness). The sutural ridge is broad, the sutural line is faintly visible and the polar filaments are coiled 4–5 times. This parasite is apparently associated with an epizootic in mullet.Three species of beloniform fishes from south Florida waters were examined for myxosporidan parasites. New host records and extensions of ranges are provided for Myxidium sphaericum Thélohan in Strongylura timucu (Walbaum) (timucu), and Ceratomyxa aggregata Davis in Hyporhamphus unifasciatus (Ranzani) (halfbeak). A single spore of the genus Myxidium was found in the gall bladder of Hemiramphus brasiliensis Linnaeus (ballyhoo).
Trypanosoma gerrhonoti n. sp., and Extrinsic Development of Lizard Trypanosomes in California Sandflies
Authors: AYALA STEPHEN C. , McKAY JEAN GRAHAM 
Published: May 2007

SYNOPSIS:Trypanosoma gerrhonoti n. sp. is described from southern alligator lizards Gerrhonotus multicarinatus of central California. It is the 2nd trypanosome species described from western North America. Extrinsic development of T. gerrhonoti and T. scelopori of western fence lizards was observed in phlebotomine sandflies Lutzomyia vexatrix occidentis, the probable natural vector. Both trypanosomes establish dense anterior midgut infections composed of long, thin epimastigotes.
Some Quantitative Aspects of the Adoptive Transfer of Immunity to Plasmodium berghei with Immune Spleen Cells
Authors: ROBERTS J. A. 
Published: May 2007

SYNOPSIS. Some of the parameters concerned in the adoptive transfer of immunity to P. berghei in rats have been studied. Immunity was not transferred efficiently until about 10 days after recovery of donor rats had commenced, but thereafter was very effective, even after the infection appeared to have been sterilized.Animals protected by a standard dose of cells from immune spleens but challenged with different doses of parasites attained a parasitemia of about 5% at different times, but all overcame the infection at the same time.Animals protected by different doses of cells from immune spleens and challenged with a standard dose of parasites, attained a parasitemia of about 5% simultaneously but the time taken to control the infection was inversely proportional to the dose of protective cells.Up to a parasitemia of about 5% there was no difference in the multiplication rate of parasites in control animals, in animals which were not effectively protected and in protected animals. Beyond a parasitemia of about 5% there was no difference in the multiplication rate of parasites in control animals and in animals which were not effectively protected.It is suggested that there is a critical period at a parasitemia of about 5% when the level of the immune response determines the fate of the host. At that stage the immune response may be inadequate, or possibly exhausted, and the parasite will then continue to multiply unchecked. Saturation of reticulocytes with parasites at a level of about 5% total parasitized red cells probably gives the host a respite which may allow the adoptively transferred cells to control the infection.
Fine Structure of the Mastigont System in Tritrichomonas muris (Grassi)*
Authors: DANIEL WENDELL A. , MATTERN CARL F. T. , HONIGBERG B. M. 
Published: May 2007

SYNOPSIS. Tritrichomonas muris shares many fine‐structural details with the previously described members of the family Trichomonadidae, and especially with the organisms belonging to the subfamily Tritrichomonadinae. Among the features which T. muris has in common with all Trichomonadidae and in all probability with other Trichomonadida are the arrangement and structure of: the kinetosomes; many rootlet filaments, including the sigmoid filaments of kinetosome #2; the parabasal apparatus; and the pelta‐axostyle complex. The structures which T. muris‐type flagellates share with other Tritrichomonadinae, and especially with Tritrichomonas augusta‐type species (including T. foetus), but not with Trichomonadinae that have been studied to date, are: the Type A costa; a comb‐like structure, which appears to have replaced the costal base of Trichomonadinae and of Hypotrichomonas; the suprakinetosomal body, rudimentary in T. muris; and the infrakinetosomal body. The undulating membrane, like that of T. augusta‐type organisms, consists of a proximal and a distal part. The proximal part, which contains the proximal marginal lamella, is less developed in T. muris than in T. augusta‐type flagellates, being represented by a relatively low ridge for the entire length of the organism. The distal part of the membrane in T. muris, on the other hand, is more highly developed; it is a heavy cord, with a distal marginal lamella which consists of a large triangular organelle having a highly ordered structure and 2 less well defined cords distal to this organelle. The tubules of the recurrent flagellum occupy the area distal to the cords. The sigmoid filaments of kinetosome #2, unlike those of other Trichomonadidae examined to date, extend posteriorly to the peltar‐axostylar junction; they seem to terminate within the cytoplasm near, but not connected to the axostyle. In addition to the Type A costa, there is a small rootlet filament, which appears to be homologous to the rudimentary costa noted in Hypotrichomonas. Some of the paraxostylar and paracostal granules consist of an outer, relatively dense layer and an inner “core” of moderate density; between the 2 there is a lucent ring.The discussion deals in some detail with the possible nature of the paraxostylar and paracostal granules in trichomonads. The taxonomic status of Tritrichomonas cricetus (Wantland) [Tritrichomonas criceti (Wantland) emend. Levine] and Trichomonas criceti Ray & Sen Gupta is discussed in an appendix; it is concluded that both of these names are synonyms of T. muris (Grassi).
Preliminary Observations on the Fine Structure of the Pansporoblast of Thelohania bracteata (Strickland, 1913) (Microsporida, Nosematidae) as Revealed by Freeze‐Etching Electron Microscopy
Authors: LIU T. P. , DARLEY J. J. , DAVIES D. M. 
Published: May 2007

SYNOPSIS. The ultrastructure of a microsporidan pansporoblast was observed with freeze‐etching electron microscopy. The cross‐fractured face of ovoid mature spores, with the upper part of the spore coat fractured off, revealed the spore membrane; the convex face had many small depressions and the concave face bore fine particles. In cross‐section the spore‐coat was highly laminated and about 0.5 μ in diameter.In the cytoplasm of the pansporoblast, fluid‐filled and finger‐print‐life profiles of vesicles were observed. The vesicles were approximately 180 nm in diameter and laminated, each lamella being about 15–18 nm thick. In addition to these vesicles, a population of elevations, each with an average diameter of 40 nm, was evenly distributed in the pansporoblast among the spores. No other cytoplasmic organelles were observed within the pansporoblast. The pansporoblast wall was about 15–19 nm thick with particles 15–18 nm in diameter on its outer surface.
The Fine Structure of Differentiating Merozoites of Haemoproteus columbae Kruse*
Authors: BRADBURY PHYLLIS CLARKE , GALLUCCI BETTY B. 
Published: May 2007

SYNOPSIS. The first sign of merozoite formation in schizonts of Haemoproteus columbae is the accumulation of dense material at intervals beneath the plasma membrane of the schizont. The schizont's membrane then invaginates in deep furrows cleaving the parasite into pseudo‐cytomeres. thereby increasing the area of membrane available for differentiation. Signs of differentiation appear under this membrane as soon as it is formed. Rhoptries and polar rings develop in the region of the dense accumulations, the cytoplasm containing these structures begins to elevate, and each evagination differentiates into a merozoite. When the merozoite is half‐formed, the cytostome appears, then dense bodies at the apex of the organism, and finally a spherical body intimately associated with a mitochondrion. These merozoites of Haemoproteus are assumed to be the forms that penetrate erythrocytes and become gametocytes. They contain the same organelles as merozoites of Plasmodium. However, the merozoites of Haemoproteus are oval like the erythrocytic merozoites of Plasmodium rather than elongate like the exoerythrocytic merozoites. This body shape may be a generic characteristic or it may indicate a structural difference between exoerythrocytic merozoites and merozoites that infect erythrocytes.When the merozoites of Plasmodium, Haemoproteus and Leucocytozoon are compared, the first 2 genera appear closely related, but Leucocytozoon seems very different. Perhaps it should not be included within the Haemoproteidae.
Lightmicroscopic Observations on Structure and Division of Histomonas meleagridis (Smith)*
Authors: HONIGBERG B. M. , BENNETT CAROLYN J. 
Published: May 2007

SYNOPSIS. Culture forms and lumen‐dwelling phases of the ameboflagellate Histomonas meleagridis, which are structurally indistinguishable from each other, have a single flagellum. Their well‐developed pelta is connected to the anterior segment of the broad, spatulate axostylar capitulum, applied to the left‐ventral surface of the nearly spheroid or somewhat ellipsoid or ovoid nucleus. The capitulum narrows into a very slender axostylar trunk that tapers to a fine point and does not project beyond the body surface. The parabasal apparatus consists of a V‐shaped parabasal body and a large parabasal filament.A new flagellum appears early during division and soon approaches its full length. The 2 flagella persist thruout division and each becomes the locomotory organelle of a daughter histomonad. The arms of the parental parabasal body appear to separate, each going to 1 of the daughter mastigont systems; some parabasal material is lost early in division. The 2nd arm is regenerated in each daughter parabasal body. The large parabasal filament seems not to be retained in the parental mastigont system, and new filaments are seen at both poles before 2 daughter nuclei are formed. The old axostyle degenerates from the anterior toward the posterior end; at the same time lamellar primordia of the daughter pelta‐axostyle complexes appear in the separating mastigont systems that are connected by an extranuclear spindle during the entire division process.The structure and taxonomic status of H. meleagridis are discussed in the light of this and previous studies.
Malarial Parasites of the “Jesu Cristo” Lizard Basiliscus basiliscus (Iguanidae) in Panama
Authors: TELFORD SAM R. 
Published: May 2007

SYNOPSIS. The iguanid lizard Basiliscus basiliscus in Panama is parasitized by Plasmodium basilisci and P. achiotense sp. nov. P. basilisci in this host is characterized by schizonts containing 4–14 merozoites, with schizonts parasitizing proerythrocytes containing more merozoites than those in erythrocytes. Asexual parasites lack cytoplasmic projections, while mature gametocytes are round or oval with regular margins.P. achiotense is characterized by the combination of prominently pigmented, large schizonts containing 36–56 merozoites and oval or round gametocytes which are about 1/3 larger than those of P. basilisci.EE‐schizonts of P. basilisci were observed commonly in thrombocytes and occasionally in lymphocytes, and appeared early in experimental infections induced by blood inoculation.
Immunization by Irradiated Eimeria acervulina
Authors: ALI NAZIK ABU , BINNERTS W. T. , KLIMES B. 
Published: May 2007

SYNOPSIS. In 5 experiments the infectivity and immunogenicity for chickens of sporulated oocysts of Eimeria acervulina that had been previously subjected to different levels of gamma radiation was tested. It was found that the irradiation doses can be divided into three groups: a) High dosage levels of over 16,000 rad impair the reproduction of the parasites so that few or no oocysts are discharged and no immunity is produced. b) Low dosage levels of 7,000 rad and less permit reproduction and development of immunity not perceptibly different from that resulting from unirradiated oocysts. c) An intermediate range of levels with the optimum from 9,100–13,700 rad induces attenuation while at the same time assuring sufficient immunogenic response.A dose of 100,000 oocysts or more per bird is required to produce immunity. The optimum irradiation dose increases with the immunizing dose. It was concluded that the development of an irradiated vaccine is possible.