bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stempellia milleri sp. n. (Microsporida: Nosematidae) in the Mosquito Culex pipiens quinquefasciatus Say*
Authors: HAZARD EDWIN , FUKUDA TOKUO 
Published: May 2007

SYNOPSIS
Stempellia milleri
sp. n. was found in blood cells and the adipose tissue of field‐collected larvae of Culex pipiens quinquefasciatus Say. Its development is different from other Stempellia species described in that it is dimorphic, producing two types of spores in adipose cells. Both were studied with the electron microscope. One spore is thin‐walled and uninucleate; the other is thick‐walled and binucleate. The latter spores are produced from sporonts that are somewhat similar to those of Nosema. Sporoblasts and spores of S. milleri were compared to those of Stempellia magna Kudo, and Stempellia lunata Hazard and Savage in both light and electron microscope preparations. S. milleri was transmitted experimentally to Culex pipiens pipiens, C. p. quinquefasciatus, C. salinarius, C. tarsalis, and C. territans. Transmission of S. magna to its host and other mosquito species was not possible. Although, generally low numbers of test larvae became infected with the pathogen, heavy infections were seen occasionally in individual specimens of its natural host, C. p. quinquefasciatus. Species of Aedes, Anopheles, Culiseta, Psorophora, and Uranotaenia exposed to spores of S. milleri were not susceptible to the disease.
Mechanism of Acquired Immunity Induced by “Leptomonas pessoai” against Trypanosoma cruzi in Mice*
Authors: SOUZA MARIA DO CARMO , REIS A. P. , DA SILVA W. DIAS , BRENER Z. 
Published: May 2007

SYNOPSISLiving culture forms of “Leptomonas pessoai” cross protected mice against T. cruzi challenge infection. Circulating antibodies have been detected in the immunized mice by immunodiffusion analysis, passive hemagglutination, complement fixation test and antibody binding assay; these antibodies cross reacted with T. cruzi extracts. A cellular immune response was indicated by leucocyte migration inhibition using L. pessoai and T. cruzi antigens, strongly suggesting a role for cell‐mediated immunity in the mechanism of protection induced by L. pessoai.
Tryptophan Metabolism in Ochromonas malhamensis
Authors: MURDIA URMILA S. , TAMHANE D. V. 
Published: May 2007

SYNOPSISTryptophan enhanced the growth of Ochromonas malhamensis at concentrations up to 0.4 mg/ml; higher concentrations inhibited, the growth inhibition being reversible by tyrosine and adenine. The presence of a tryptophan synthetase system in vitro was demonstrated. Tyrosine and phenylalanine stimulated the activity of this enzyme. The uptake of exogenous tryptophan was accompanied by an increase in the free tryptophan pool which in turn suppressed the tryptophan synthetase system, thus pointing to a controlled mechanism. Incorporation of tryptophan in the growth medium enhanced the biosynthesis of folate‐active compounds. An elucidation of the mode of action of tryptophan is attempted on the basis of known metabolic pathways.
Glucose Transport in the Malarial (Plasmodium lophurae) Infected Erythrocyte*
Authors: SHERMAN IRWIN W. , TANIGOSHI LINDA 
Published: May 2007

SYNOPSISPlasmodium lophurae‐infected red blood cells utilized considerably greater quantities of glucose than did uninfected duckling red cells. Kinetic analysis of glucose transport showed: (A). Below a concentration of 2 mM in the medium the uptake process followed Michaelis‐Menten kinetics (carrier‐mediated facilitated diffusion) whereas at concentrations greater than this simple diffusion became the main mode of entry. (B). The apparent transport constants, Kt, for normal and infected cells were similar. However there was an 8‐fold increase in the maximal velocity, Vmax, for infected cells. (C). “Free” malaria parasites had a significantly lower Kt and a higher Vmax than did normal or infected red cells. Entry and exit studies with the nonmetabolizable sugar analog, 3‐0‐methyl glucose, demonstrated that the enhanced rate of uptake by infected cells involved an increase in the simple diffusion component and the degree of enhancement was correlated with the size of the intracellular parasite. Competition experiments suggested that in the malaria‐infected cell one locus is involved in the carrier‐mediated transport of glucose, mannose and galactose whereas another locus transports fructose and/or glycerol. These results indicate that the enhanced entry of glucose into the malaria‐infected red cell is a consequence of factors other than increased glucose catabolism by the host‐parasite complex, and the host cell's capacity to take up greater quantities of sugar directly involves the growing intracellular plasmodium.
Infectivity and Immunogenicity of Irradiated Babesia rodhaini*
Authors: BISHOP J. P. , KUTTLER K. L. 
Published: May 2007

SYNOPSIS. Babesia rodhaini‐parasitized mouse blood exposed to varied doses of γ radiation up to 30 kRad was inoculated into mice. Mice inoculated with nonirradiated B. rodhaini developed progressive infections and died 7–11 days postinoculation. Mice infected with B. rodhaini‐parasitized blood exposed to doses up to and including 22 kRad developed progressive parasitemias which were delayed in comparison to mice inoculated with non‐irradiated B. rodhaini. Some mice receiving parasitized blood irradiated at 26 kRad did not develop progressive parasitemias. Progressive infections were prevented by exposure to irradiation at 30 kRad.The results of 2 separate experiments revealed that one inoculation of parasitized blood exposed to 30 kRad or higher apparently stimulated a resistance to a challenge infection with nonirradiated parasitized blood. While 20 of 20 control mice died as a result of challenging infections, 9 of 28 mice previously exposed to irradiated parasitized blood survived.The injection of irradiated nonparasitized blood did not produce a discernible acquired resistance to B. rodhaini. Presumably the irradiated parasitized blood was responsible for the development of acquired resistance to B. rodhaini.
Isolation and Characterization of Kinetoplast DNA Networks and Minicircles from Crithidia fasciculata*
Authors: SIMPSON AGDA M. , SIMPSON LARRY 
Published: May 2007

SYNOPSIS. Covalently closed kinetoplast DNA networks have been isolated from stationary phase Crithidia fasciculata cells by a technic involving selective pelleting of the networks at a low centrifugal field. Approximately 62% of the kinetoplast DNA of the cell was recovered free of nuclear DNA by simple differential centrifugation.Purified kinetoplast DNA networks were visualized both in the electron microscope and in the light microscope. Closed networks sedimented as a homogeneous band both in neutral and alkaline sucrose, with an s20w in neutral sucrose of approximately 5 × 103.Closed monomeric minicircles were isolated from purified networks by mild sonication and band sedimentation in alkaline sucrose. Several physical properties of closed monomeric minicircles were measured. These included molecular weight, buoyant density in CsCl, superhelix density and sedimentation coefficient.
Effects of Thiamine Deprivation and Replacement on the Mitochondrion of Polytomella agilis*
Authors: CANTOR MARVIN H. , BURTON MIRIAM D. 
Published: May 2007

SYNOPSIS. Late log‐phase cells of Polytomella agilis, grown with or without thiamine, were examined by electron microscopy. The mitochondrial profiles of cells cultivated in the presence of thiamine are relatively few in number and irregular in shape. The inner membranes, randomly dispersed in a light matrix, are elongated, vesicular, or branched in appearance. In vitamin‐deficient cells, numerous mitochondrial profiles are evident. They have a regular circular or ovoid appearance. The inner membranes are regularly arrayed in an electron‐dense matrix and generally appear elongated. By means of partial 3‐dimensional reconstruction of whole cells the appearance of mitochondrial profiles in vitamin‐deficient cells can be explained by the increased branching of a single structure. Following transfer of vitamin‐deficient cells to complete medium, normal mitochondrial structure is attained by ∼3 hr.Reduced‐minus‐oxidized difference spectra of suspensions of normal and vitamin‐deficient cells, grown with gentle aeration, were recorded. The concentrations of a‐ and b‐type cytochromes are reduced by 80‐90%, and c‐type cytochromes are reduced by 40% in thiamine‐deficient cells.
Recherches Cytochimiques sur la Microsporidie Nosema bomycis au cours de son Développement chez le Ver à Soie (Bombyx mori)*
Authors: TAKIZAWA HIROMI , VIVIER EMILE , PETITPREZ ANDRE 
Published: May 2007

RESUME. La Microsporidie Nosema bombycis, Protozoaire parasite agent de la pébrine du ver à soie, a étéétudiée cytochimiquement à la fois en microscopie photonique et électronique.Les examens ont porté sur la détection et la localisation des acides nucléiques (ADN et ARN), des polysaccharides, de la phosphatase acide, au cours des différents stades du développement dans les cellules de I'hôte (du schizonte à la spore).Les principaux résultats concernent les observations relatives aux polysaccharides et à la phosphatase qui ne sont détectés qu'au stade de la spore et ne sont pas observés au stade du schizonte. Les polysaccharides sont présents au niveau du sac polaire, du filament polaire et sur la membrane cytoplasmique; la phosphatase acide est localisée au niveau du sac polaire, du filament polaire et dans la vacuole postérieure.SYNOPSIS. Nosema bombycis, agent of pebrine disease of silkworm, was studied cytochemically, using both light and electron microscopy. Presence of nucleic acids (DNA and RNA), polysaccharides, and acid phosphatases was demonstrated and localization of these substances was determined in various stages of the parasite (from the schizont to the spore). DNA and RNA were detected in all these stages. Polysaccharides and acid phosphatase were found in the spore but not in the schizogonic stages. Polysaccharides were detected in the polar cap, the polar filament, and the limiting membrane of the cytoplasm of the spore. Acid phosphatase was found in the polar cap, the polar filament, and the posterior vacuole.
Activité Cellulolytique des Ciliés Entodiniomorphes
Authors: BONHOMME‐FLORENTIN A. 
Published: May 2007

RESUME. Dans nos travaux antérieurs, nous avons observé dans les cultures in vitro que la disparition de la cellulose (languettes de papier filtre) est 2 fois plus grande lorsque les 2 micropopulations, Entodinium et bactéries, sont présentes que lorsque les bactéries sont seules ou en présence de cellules mortes de ciliés. Les filtrats des broyats cellulaires des ciliés entodiniomorphes de la panse des ruminants et du caecum des équidés possèdent une activité cellulolytique indépendante des bactéries endocellulaires. Il s'agit essentiellement d'une polyglucosidase (Cx) qui dégrade les dérivés de la cellulose native. On observe également une légère activité cellulolytique C1 sur la cellulose native.SYNOPSIS. We have observed previously that twice as much cellulose disappears from cultures containing both Entodinium and bacteria than from those which contain bacteria alone or with dead ciliates. Filtrates of cell‐free homogenates of the entodiniomorphid ciliates from sheep rumen and horse cecum have a hydrolytic effect upon cellulose, hydrolytic activity being independent of the intracellular bacteria. The predominant enzyme involved in the reaction is a polyglucosidase (Cx) which acts upon derivatives of native cellulose. Low level activity of enzyme C1, which attacks native cellulose, also is found in the filtrate.
Quantitative Ultrastructural Investigations of the Life Cycle of Trypanosoma brucei: A Morphometric Analysis*
Authors: BÖHRINGER S. , HECKER H. 
Published: May 2007

SYNOPSIS. The quantitative ultrastructure of the developmental stages of Trypanosoma brucei brucei in its vector Glossina morsitans was studied by morphometric analysis. Values from ectoperitrophic midgut forms, proventricular forms, epimastigote and metacyclic forms in the salivary gland are compared with results from bloodstream forms, published previously.Significant differences in the volume densities of the trypanosome's single mitochondrion, of microbody‐like organelles and in the surface densities of inner and outer mitochondrial membranes were found throughout the whole life cycle.A great increase in volume density of the mitochondrion was observed after transfer to the insect host; reduction took place during metacyclic development. Parallel to the biogenesis of the mitochondrion a reduction of microbodies was found in proventricular forms and there was a great increase in metacyclic forms concomitant with the regression of the mitochondrion. Metacyclic forms had a close quantitative morphologic similarity to bloodstream forms.The results are discussed in connection with changes in structure and in oxidative metabolism.
Further Electrophoretic Characterization of Strains of Tetrahymena pyriformis*
Authors: NIELSEN P. JAMES , ANDRONIS PAUL T. 
Published: May 2007

SYNOPSISMobility patterns of 5 isozymes in strains of Tetrahymena pyriformis were demonstrated using polyacrylamide disc gel electrophoresis. Six stock strains were compared in these patterns to 4 strains representative of each of the previously described 4 major “phenotypic sets.” Stock strains segregated into predicted “phenosets,” and essentially confirmed validity and reproducibility of such a discrimination method. The proposal that new strain designations be assigned on a basis of “phenoset” conformity is reaffirmed.
Comparaison du Fonctionnement des Bandes de Réorganisation d'Euplotes crassus (Dujardin) et de Strombidium sulcatum Claparède et Linné après Analyse Microspectrographique en UV
Authors: SALVANO PAULE 
Published: May 2007

RESUMEIl y a duplication de l'ADN en bordure de la “rear zone” du macronoyau (zone 4 d'Euplotes crassus, zone 3 de Strombidium sulcatum). L'augmentation du taux des protéines commence avant l'augmentation du taux de l'ADN chez les 2 Ciliés. De même il y a une variation du taux de l'ARN dans la bande de réorganisation, la plus grande teneur étant dans la zone où il y a augmentation nette du taux des protéines.SYNOPSISThe rear zone of the macronucleus, zones 4 and 3 in Euplotes crassus and Strombidium sulcatum, respectively, is the site of DNA duplication. In both ciliates, increase in protein levels precedes that of DNA. There are also variations in the RNA level in the reorganization band, with the highest RNA content being found in the zone richest in protein.
The Effect of Host Constitution on the Development of Plasmodium floridense*
Authors: JORDAN HELEN B. 
Published: May 2007

SYNOPSISMore than 15,000 lizards from South Georgia were examined over a period of 16 years. Five percent of Sceloporus undulatus and 36% of Anolis carolinensis were found to harbor Plasmodium floridense. Development of 28 natural new infections was followed in detail as soon as they became patent and comparisons in the 2 host species made of intensity and duration of infections and of merozoite means during the periods of acute rise and decline. During the acute rise, the merozoite mean in Sceloporus was 10.6 ± 0.11 (8,495 segmenters counted), compared with 13.44 ± 0.15 in Anolis (3,805 counted); during the decline, the merozoite means were 8.55 ± 0.13 (3,305 counted) and 10.28 ± 0.09 (6,772 counted), respectively. It took an average of 150 (100–253) days for the infection to run its course in Sceloporus, compared with the average of 71 (60–90) days in Anolis; the peak of parasitemia in Sceloporus was 11,600 parasites/10,000 red cells, compared with 1,600 in Anolis. Both lizard genera produced 5–10% gametocytes.
Extraction and Preliminary Use for Diagnosis of Soluble Precipitating Antigen from Babesia bigemina*
Authors: GOLDMAN MORRIS , BUKOVSKY ESTHER 
Published: May 2007

SYNOPSISSoluble antigen from bovine blood with a Babesia bigemina parasitemia of 5–6% formed 4 precipitin lines in gel diffusion tests with antiserum from infected cattle. Antigen was obtained from plasma and hemolysate by elution from DEAE cellulose columns and (NH4)2SO4 precipitation as well as from washed parasite‐erythrocyte stroma by sonication or freezethawing. About 5 ml of antigen suitable for diagnostic tests could be extracted from 200 ml of infected blood.
Contractility of Glycerinated Amoeba proteus and Chaos‐chaos*
Authors: RINALDI ROBERT , OPAS MICHAL , HREBENDA BARBARA 
Published: May 2007

SYNOPSISImmediate contact with large volumes of cold 50% (v/v) buffered glycerol preserved typical ameboid shape of Chaos chaos and Amoeba proteus with no visible distortions. These technics allowed determination of the contraction sites in these glycerinated models upon application of ATP‐Ca‐Mg‐solutions. The ectoplasmic tube was the main site of contraction. Preliminary EM investigations revealed thick and thin filaments, associated with the ectoplasmic tube near the plasmalemma, which appeared to be the basis for the contractility of the ectoplasmic tube. There was no predominant contraction of the pseudopodial tips or the endoplasm in these models. The changes of volume were as much as 50%, and in some cases were not accompanied by any change in the length of the ameba; however, lengthwise contractions of the ectoplasmic tube in some amebae occurred to as much as 25%. The data substantiate a basic requirement of the ectoplasmic tube contraction theory of ameboid locomotion.
The Cell Surface of Trypanosoma musculi Bloodstream Forms. II. Lectin and Immunologic Studies*
Authors: DWVER DENNIS M. , D'ALESANDRO PHILIP A. 
Published: May 2007

SYNOPSIS. Living Trypanosoma musculi bloodstream trypomastigotes were agglutinated specifically with concanavalin A (ConA), wheat germ agglutinin (WGA), soybean agglutinin (SBA), and fucose‐binding protein (FBP). The agglutination with these lectins of living cells from which the coat was removed by trypsinization was the same as with intact trypanosomes. Glutaraldehyde or formalin fixation did not affect the results with regard to agglutination with WGA, SBA, and FBP, but lower agglutination with ConA was observed upon fixation. By using a dense iron‐dextran marker many fewer ConA marker particles were localized at the fine structural level in the intact than in trypsin‐treated trypanosomes. On the basis of the results obtained by agglutination and electron microscopy, it is likely that fixation cross‐links intact surface‐coat components associated with the ConA binding sites. It is evident from the studies in which lectins were employed that ligands containing α‐D‐mannose, N‐acetylglucosamine, N‐acetylgalactosamine, and α‐L‐fucose are randomly distributed in the outer surface of the pellicular and flagellar membranes of T. musculi trypomastigotes. Results obtained with α‐amylase‐ and dextranase‐treated trypanosomes suggested that lectin‐binding sugar ligands in the cell surface were not directly associated with α‐1,4 or repetitive α‐1,6 glucan‐bonded polysaccharide moieties. Similar conclusions can be drawn on the basis of neuraminidase treatment with regard to N‐acetylated neuraminic acids.After thorough washing, intact, but not trypsin‐treated trypomastigotes were agglutinated specifically with antisera against whole mouse serum and against mouse IgG. Evidently, adsorbed constituents of mouse serum are regular components of the T. musculi surface coat. After incubation in dilute whole mouse serum or in mouse IgG solutions, also the trypsinized cells were agglutinated by the 2 antisera. No such results were obtained with trypsinized cells incubated in serum‐free buffers. It was concluded that mouse serum proteins were readily readsorbed on, and firmly bound to the trypsinized cells' surfaces. Specific agglutinations were obtained with trypsinized cells after incubation in dilute rat, rabbit, bovine, and human sera and in solutions of rat and rabbit IgG in reactions with the corresponding antisera. It seems, therefore, that the host serum proteins are adsorbed nonspecifically to the cell surface of trypsinized T. musculi bloodstream forms.When examined by electron microscopy, the intact trypomastigotes were covered by an ununiform, slightly granular, fibrillar extracellular coat, applied to the entire outer lamina of the pellicular and flagellar membranes. No indication of such a coat was noted in the trypsinized organisms. Flocculent surface coat‐like matrix could, however, be discerned in cells which, after trypsinization, were incubated in various sera.
Effects of Actinomycin D on Generation Time and Morphogenesis in Paramecium*
Authors: KACZANOWSKA JANINA , HYVERT NICOLE , DE HALLER GERARD 
Published: May 2007

SYNOPSIS. The sensitivity of Paramecium tetraurelia (=P. aurelia syngen 4) cells to pulse treatments with various doses of Actinomycin D (AMD) was estimated by comparing the generation times of treated and untreated sister cells. It was found that the delay of division in treated cells depended on the concentration of AMD, on their “age” at the time of the pulse treatment, and on their individual sensitivity.Sensitivity of Paramecium to AMD changes during the cell cycle in a predictable way. About 3 1/2 hr before the normally expected cell fission (total generation time ∼ 5 1/2 hr) there is a decrease of sensitivity. Thereafter, the cell enters a new stage with a progressive increase of sensitivity. This 2nd phase ends at the “transition point” (∼ 2 hr before cell division), when sensitivity drops abruptly. The division process itself may be altered and slowed down by high concentrations of AMD, even if the drug is applied after the transition point, but this process can never be completely annulled. The impairment of the division mechanism may lead to morphologic anomalies in the offspring.Resorption of oral anlagen in P. tetraurelia probably never occurs during the cell cycle after AMD treatment.The reason for individual variability of the cells, mechanisms controlling development, and the question of an obligate sequence of gene action in each cell cycle are discussed.
Ultrastructure of Sporulation in the European Flat Oyster Pathogen, Marteilia refringens—Taxonomic Implications*
Authors: PERKINS FRANK O. 
Published: May 2007

SYNOPSIS. By fine‐structural studies of speculation stages in the European flat oyster pathogen Marteilia refringens this organism is shown to be a member of the protozoan class Haplosporea. This conclusion is based on observations that haplosporosomes are found in plasmodia and spores and that sporoplasm delimitation occurs by internal cleavage within plasmodia. During sporulation plasmodia become sporangiosori by enlarging, cleaving internally into ∼ 8 sporangia, each of which then cleaves internally into 3 or 4 spore primordia. The primordia divide into 3 uninucleate sporoplasms of graded sizes, the smallest lying in an eccentrically located vacuole of the medium‐sized one, and the latter situated within an eccentric vacuole of the largest. Haplosporosomes are found only in the cytoplasm of the largest sporoplasm. Mature, living spores measure 3.9(3.5–4.5)μm diameter and are enclosed in a continuous wall without a mantle of epispore cytoplasm as in other Haplosporea.An amended genus and species description of Marteilia refringens is presented, based on light and electron microscope observations.