bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ultrastructure of the Marine CryptomonadChroomonas salinaCultured under Conditions of Photoautotrophy and Glycerol‐Heterotrophy*
Authors: ANTIA N. J. , KALLEY J. P. , McDONALD J. , BISALPUTRA T. 
Published: May 2007

SYNOPSIS.Chroomonas salinawas cultured in seawater medium enriched with nitrate, phosphate, silicate, trace‐metal ions, and vitamins, under 3 conditions: (A) light without other organic additions (photoautotrophic); (B) light and added glycerol (photoheterotrophic); (C) in darkness but with added glycerol (chemoheterotrophic). The heterotrophic cultures were initiated from a stock maintained on glycerol in continuous darkness for 41/4 years. The autotrophic culture was initiated from a corresponding stock maintained under continuous illumination without any organic growth substrate. The fine structure of organisms from simultaneously initiated cultures was compared after 1, 2, 3, and 4 weeks of growth.“Young'’cells from the autotrophic and heterotrophic cultures of comparable maturity had no recognizable ultrastructural difference. In organisms from both the photoautotrophic and photoheterotrophic cultures there was a progressive accumulation of starch and lipid with aging, but whereas in cells from the former the production of starch was arrested after early growth and lipid was concentrated thereafter, in those from the latter both metabolites continued to be produced with consequent rapid degeneration of the cytoplasm followed by autolysis. By contrast, flagellates grown in the chemoheterotrophic culture accumulated only starch, with vacuole formation replacing the lipid stores. In all cases, the lipid bodies appeared to differ from the membrane‐bound droplets normally observed, which actually diminished with aging. Starch accumulation appeared to cause more rapid cytopathologic changes and autolysis. No evidence of chloroplastic phycobilisome‐type aggregations was noted in organisms from any culture at any age.
Entodiniomorph Ciliates from the Stomach of Hippopotamus amphibius, with Descriptions of Two New Genera and Three New Species
Authors: THURSTON JUNE P. , NOIROT‐TIMOTHÉE CÉCILE 
Published: May 2007

SYNOPSISEntodiniomorph ciliates, belonging to the family Cycloposthiidae, are described from the stomach contents of Hippopotamus amphibius.Monoposthium acanthum gen. n., sp. n., with typical cycloposthiid structure, differs from other genera in having only 1 caudalium. Parentodinium gen. n., represented by P. africanum sp. n. and P. ostrea sp. n., although superficially resembling Entodinium, is considered to be a relatively unspecialized cycloposthiid.
On the Fine Structure of Trypanosoma cruzi in Tissue Cultures of Pigment Epithelium from the Chick Embryo. Uptake of Melanin Granules by the Parasite*
Authors: MEYER H. , DE SOUZA W. 
Published: May 2007

SYNOPSISTrypanosoma cruzi has been cultured in pigment epithelial cells of the iris from the chick embryo. Melanin granules, identical with those of the host cells were found in the intracellular, amastigote (leishmania) forms. In many of the intracellular forms cytostome‐like structures were seen, often in intimate contact with the pigment granules of the host cells, which suggests the uptake of melanin granules through the cytostomes by the process of intracellular phagotrophy.
Comparative Development of Eimeria tenella from Sporozoites to Oocysts in Primary Kidney Cell Cultures from Gallinaceous Birds
Authors: DORAN DAVID J. , AUGUSTINE PATRICIA C. 
Published: May 2007

SYNOPSISEimeria tenella completed its endogenous life cycle in primary cultures of kidney cells from 2‐ to 3‐week‐old‐chickens, guinea fowl, partridges, pheasants, quail, and turkeys. Similarity in percentage of infection at 4 hr suggested that sporozoites entered cells from all birds in equal numbers. Development was better, however, in chicken cells in that the percentage of survival and of developmental stages during the first 2 days were greater, developmental stages occurring after 2 days usually were found earlier, mature 2nd‐generation schizonts and oocysts were larger, and oocyst production was far greater than in nonhost cells. Multinucleate macrogametes, which sometimes reached sizes 3–4 times greater than normal oocysts, are reported for the first time.
The Positioning of Ciliary Organelles in Hypotrich Ciliates*†
Authors: FRANKEL JOSEPH 
Published: May 2007

SYNOPSISIt is commonly observed in hypotrichs that new ciliary rudiments arise directly from or in close juxtaposition to certain pre‐existing ciliary elements. Oral primordia often are initiated near specific cirri, cirral rudiments frequently arise as a result of the disaggregation of certain old cirri, and new dorsal ciliature is formed within pre‐existing ciliary rows. In the first 2 situations it has been demonstrated experimentally that neither the old ciliature in question nor the specific cortical site marked by that ciliature is essential for the appearance of the new cirral rudiment. The experimental analysis done thus far suggests that the positions of oral and cirral primordia are determined by interacting gradients established in relation to certain reference points. The nature of the reference points is not fully elucidated; in some cases at least these points appear to be more closely related to topographic features of the cell than to specific pre‐existing cortical structures.In the dorsal ciliary rows of Euplotes new ciliary units are formed usually and perhaps invariably in close proximity to old ones, and are generally oriented along the axis of the pre‐existing row. The result is a tendency to perpetuate the preexisting row number across cell generations. Changes in row number, however, can occur as a result of occasional formation of new units at right angles to the row, a process that is much enhanced in certain homozygous segregants (basal body deficient). The optimal row number (stability range) as well as the number of ciliary units are under genic control. In addition, the spatial pattern of distribution of ciliary units among rows is invariant in all of the material examined. This pattern is presumed to result from an underlying field whose geometry is independent of both the number of units and the number of rows.
The Use of Protamine‐Coated Slides for Immobilizing Protozoa*
Authors: MARSOT PIERRE , COUILLARD PIERRE 
Published: May 2007

SYNOPSISFresh‐water, marine or parasitic protozoa can be immobilized for microscopic observation on protaminecoated slides. They appear not to be harmed by this procedure. The type of protamine derivative and its concentration are important, best results being obtained with 0.015–0.05% (w/v) of protamine sulfate.
Temperature Effects on Maturity Periods in Tetrahymena pyriformis Syngen 1*
Authors: PERLMAN BRUCE S. 
Published: May 2007

SYNOPSISCells of Tetrahymena pyriformis syngen 1 grown at 30 C after conjugation achieve sexual maturity more quickly than do cells grown at 19 C, whether time is measured in numbers of cell divisions or in terms of absolute time. This result is achieved regardless of the temperature at which conjugation and nuclear reorganization occur. These observations differ from those of other workers investigating Paramecium, and suggest that the long term “chronometer” is more tightly coupled to cell division in Paramecium multimicronucleatum and Paramecium caudatum than in Tetrahymena pyriformis.
Abnormalities in Nuclear Behavior and Mating Type Determination in Cytoplasmically Bridged Exconjugants of Doublet Paramecium aurelia*
Authors: BUTZEL HENRY M. 
Published: May 2007

SYNOPSISExconjugant clones of Paramecium aurelia stock 51S, syngen 4, which fail to separate prior to the 1st fission have numerous cytologic and mating type determination anomalies. The doublets have abnormal distribution of macronuclear anlagen, fewer macronuclear fragments per cell, and abnormalities in numbers of micronuclei. Despite apparent cell fusion and mixture of cytoplasm, the singlets arising from each side of the doublet may be of opposite mating types, and mating type determination may remain unstable for 1 or more fissions in contrast to the usual pattern of mating type determination before the 1st postconjugation fission.
m‐Chlorobenzhydroxamic Acid–an Inhibitor of Cyanide‐Insensitive Respiration in Trypanosoma brucei*
Authors: EVANS D. A. , BROWN R. C. 
Published: May 2007

SYNOPSISCyanide‐insensitive respiration of bloodstream and culture forms of T. brucei was inhibited by m‐chlorobenz‐hydroxamic acid (m‐CLAM). The cyanide‐sensitive respiration of culture forms of this organism was not affected by m‐CLAM. This compound is the 1st really effective inhibitor to be described that acts specifically on the cyanide‐insensitive respiration of the T. brucei group of trypanosomes; as such it may be of some importance as a trypanocidal drug.Evidence is adduced which suggests that a branched electron transport chain is present in culture forms of T. brucei and that the cyanide‐insensitive terminal oxidase found in these stages is the same as that found in bloodstream forms.
An Ultrastructural Study of the Feeding Apparatus of Peranema trichophorum
Authors: NISBET BRENDA 
Published: May 2007

SYNOPSISA model of the feeding apparatus of Peranema trichophorum Ehrenberg has been constructed from electronmicrographs. A common opening leads via a short anterior canal to the reservoir and cytostome. The cytostome lies close to the internal opening of the canal, and can be moved forward during feeding, closing the passage to the reservoir, and displacing the flagella. The cytostome is supported by the rodorgan in its floor and a double serrated marginal lamella arching over its upper rim from dense bodies lying lateral to the cytostome. A working hypothesis for the movement of the feeding apparatus is proposed. The elaborate system of articulating lamellae operates through these dense bodies which may act as “hinge joints.” The rodorgan is pulled forward by contraction of longitudinal lamellae attached near the bases of the rods. Cytoplasmic pressure may also be involved. It is suggested that the pull is transmitted through the dense bodies and 2 anchoring lamellae to crescentic canal thickenings on either side of the canal opening. The cytostome, rodorgan and double serrated marginal lamella move forward to fill the external opening of the canal, now enlarged by sideways pull from the anchoring lamellae. Withdrawal of these structures sucks food into the cytostomal sac to be packed down by contraction of the double serrated lamella. It is postulated that the rodorgan operates through adhesion and cytolysis and is not adapted for piercing. A conspicuous striated fibril and associated groups of microtubules in the left wall of the reservoir are cytoskeletal structures.
Phototaxis and Thermotaxis in Some Species of Amphistegina (Foraminifera)*
Authors: ZMIRI AHARON , KAHAN DAVID , HOCHSTEIN SHAUL , REISS ZEEV 
Published: May 2007

SYNOPSISPositive phototaxis was demonstrated in specimens of Amphistegina radiata within the range of photonic fluxes of 1011 to 1015 photons × cm‐2× sec‐1. No response was found at lower intensities. Amphistegina radiata has a Dartnall nomogram‐shaped action spectrum with a peak at ∼500 nm. In addition, A. radiata and A. madagascariensis, which had been maintained at 18 C, moved toward higher temperatures in a horizontal temperature gradient in total darkness. Amphistegina radiata and A. madagascariensis did not move at temperatures ≤ 12 C and ≤ 16 C respectively. An equal number of specimens moved toward the higher and lower temperatures in the gradient when A. radiata was placed at ∼29 C and A. madagascariensis at ∼22 C. The roles of light and temperature in the distribution of the genus Amphistegina in nature are discussed.
Relationship of Cellular Energetics to RNA Metabolism in Tetrahymena pyriformis W.*
Authors: CONNER ROBERT L. , KOROLY MARY J. 
Published: May 2007

SYNOPSISCultures of Tetrahymena pyriformis in a non‐nutrient buffer degrade RNA and excrete hypoxanthine, uracil and orthophosphate. Glucose addition leads to the retention of a portion of the purine, pyrimidine, and orthophosphate by the cells; however, the hexose has little influence on the RNA level. Acetate supplementation has no effect on RNA degradation or on the distribution of the catabolic products between the cells and the environment.Interruption of oxidative phosphorylation by 2,4‐dinitrophenol results in an increase in RNA degradation. This action is annulled by the glycolytic substrate, glucose, but not by acetate. A combination of iodoacetic acid and glucose blocks glycolysis and increases cellular RNA loss which can be reversed by the addition of the citric acid cycle substrate, acetate. These findings suggest that the available cellular energy supply in starved cells is sufficient to regulate the rate of RNA degradation. Disruption of ATP generation by the appropriate inhibitors, however, allows the demonstration of the importance of energy‐yielding reactions in the determination of the amount of nucleic acid loss. It appears that glycolysis and oxidative phosphorylation are equally efficient in sustaining the regulatory process.RNA synthesis during starvation conditions is a discontinuous process with a sharp rate change after 30 min of incubation. 2,4‐Dinitrophenol inhibits [2‐14C] uracil incorporation into the nucleic acid. Glucose does not annul the inhibition of synthesis in contrast to the influence of the hexose on RNA degradation. This observation demonstrates that the synthetic and degradative processes are not directly coupled.Glycogen synthesis and RNA degradation appear to compete for the available energy supply and respond in a similar fashion to the metabolic inhibitors and carbon sources.
Eimeria dalli sp. n. (Protozoa: Eimeriidae) from Dall Sheep Ovis dalli
Authors: CLARK GLEN W. , COLWELL DAVID A. 
Published: May 2007

SYNOPSISEimeria dalli sp. n. is described from fecal samples collected from Dall sheep, Ovis dalli, from the Kenai Peninsula, Alaska. The oocysts are spherical or subspherical with mean dimensions of 43.7 × 37.4 μm. The outer oocyst wall is rough and irregular. No micropyle, micropylar cap or residuum was observed. Sporocysts were elongate ovoid with mean dimensions of 19.0 × 10.7 μm. Stieda bodies were not discernible.
The Contractile Vacuole in Amoeba proteus: Temperature Effects
Authors: AHMAD MUKHTAR , COUILLARD PIERRE 
Published: May 2007

SYNOPSISThe influence of temperature on the various aspects of the contractile vacuole cycle of Amoeba proteus has been established. In the upper temperature range (20, 25 and 30 C) an increase in temperature results in shorter vacuolar cycles with greater systolic (final) volumes. The systole is rapid and always complete. At 35 C the vacuole shows the effect of heat stress, cycles are irregular in volume and duration with only partial systoles. In the lower temperature range (15, 10 and 5 C), a new phenomenon has been observed, the plateau. Instead of undergoing systole, after reaching a certain critical volume the vacuole abruptly ceases to grow in size and remains in a state of pause for a well defined period of time, ending at a comparatively slow but complete systole. The duration of this plateau as well as its inception and termination seem quite precisely controlled. Its effect, a decrease in the fluid output by the vacuole, is such as to adjust vacuolar output to near constant Q10 kinetics over our temperature range. This is correlated with a single straight line fit in an Arrhenius plot.Available data do not permit a complete explanation of the nature of the plateau. It could represent a steady state between 2 opposing phenomena: active fluid influx into the vacuole and osmotic losses from the vacuole into the relatively hypertonic cytoplasm.
Isolation of the Kinetoplast DNA of Leishmania tarentolae in the Form of a Network*
Authors: SIMPSON LARRY , BERLINER JUDITH 
Published: May 2007

SYNOPSISThe major kinetoplast DNA complement of Leishmania tarentolae promastigotes has been isolated as a single sheet of interconnected molecules on the basis of its relative stability to shear forces and its high sedimentation coefficient. Two successive differential centrifugations were sufficient to recover 50 ± 10% of the total kinetoplast DNA free of nuclear DNA contamination. We use the term “network” to describe this unusual type of DNA configuration.Leishmania networks have a molecular weight of ∼1010 daltons and an S20,W in neutral sucrose gradients of 1729 7plusmn; 189 [n = 19] and exhibit an extremely low specific viscosity due to the compactness of packing of the DNA. The networks were visualized in the electron microscope, and in the light microscope either by fluorescence in solution after staining with acridine orange or in dried smears after staining with Giemsa.Purified networks from stationary phase cells banded in the position characteristic of closed monomeric minicircles in ethidum bromide‐CsCl equilibrium gradients, and were stable in alkaline sucrose. Treatment of the closed networks with RNase and pronase had no effect on the ethidium bromide‐CsCl banding pattern. However, treatment of closed networks with DNase I or II, X‐irradiation or γ‐irradiation changed the banding pattern by introducing single strand and double strand breaks, yielding an upper band and in some cases a intermediate band.
Density of Parasites in Various Organs and the Relation to Numbers of Trypomastigotes in the Blood during Acute Infections of Trypanosoma cruzi in Mice*
Authors: HANSON WILLIAM L. , ROBERSON EDWARD L. 
Published: May 2007

SYNOPSISQuantitative methods were used to (a) determine the density of Trypanosoma cruzi in organs of CF1 mice following intraperitoneal inoculation of 50,000 trypomastigotes of a Brazil strain of T. cruzi and (b) study the relation of the numbers of these intracellular stages to the numbers of trypomastigotes in the blood. Tissue stages (predominantly amastigotes) in heart, skeletal muscle (triceps), diaphragm, cerebrum, cerebellum, and musculature of stomach, duodenum, esophagus, jejunum, cecum, and rectum increased in numbers during the 1st 3 weeks of infection, reached maximum density 21–28 days after inoculation and subsequently declined in numbers until mice were histologically negative for intracellular parasites by 30–40 days. The density of tissue stages in the urinary bladder, uterine body, and ileum was similar with the exception that maximum numbers of parasites were observed slightly earlier at 15 days.The greatest density of intracellular stages was seen in heart, urinary bladder, diaphragm, and triceps muscle where mean counts of 44.6–60.0 × 106 parasites/cc of muscle were recorded while maximum density of parasites in the uterine body, cerebrum, stomach, cerebellum, duodenum, esophagus, jejunum, ileum, cecum, and rectum was 13.0 × 106/cc of muscle or less. Amastigotes were not observed in sections of lymph node, thymus, salivary glands, liver, spleen, or kidney and only a single pseudocyst containing 5 amastigotes was seen in lung. With the exception of the brain and lung, intracellular parasites were located exclusively in the musculature.Trypomastigotes in the blood increased during the 1st 3 weeks of infection, reached maximum numbers 21–28 days after initiation of infection, and subsequently decreased until by 30–40 days parasites were observed only rarely in the blood of a few animals. Thus generally close correlation was noted between the numbers of intracellular stages of T. cruzi in the organs and trypomastigotes in the blood throughout acute Chagas’ disease in mice as evidenced by the concomitant increase in numbers of both stages, the coincidence of days of maximum parasite levels, and the simultaneous decline in numbers of both stages.The mean number of parasites/pseudocyst section varied in the organs studied. Of the 15 positive organs studied, the pseudocyst sections in skeletal muscle contained the highest mean number of parasites (64.3 parasites/pseudocyst section) and those pseudocyst sections seen in the musculature of the small intestine contained the lowest mean number (5.5–6.8 parasites/pseudocyst section respectively in ileum and jejunum).Serial sections of skeletal muscle, heart, urinary bladder, and stomach revealed the largest pseudocysts in skeletal muscle while those in the musculature of the urinary bladder were the smallest.
Effect of the Antiphagocytic Agent Cytochalasin B on Macrophage Invasion by Leishmania mexicana Promastigotes and Trypanosoma cruzi Epimastigotes*
Authors: ALEXANDER JAMES 
Published: May 2007

SYNOPSISUnstimulated mouse peritoneal exudate cells were cultured on coverslips in Medium 199 containing 10% (v/v) calf serum. Cytochalasin B dissolved in dimethyl sulphoxide (DMSO) and diluted in Medium 199 was added to cultures to give final concentrations of 1, 5 and 10 μg/ml. Equal numbers of Leishmania mexicana promastigotes, Trypanosoma cruzi epimastigotes and sheep red cells were added to 24 hr cultures incubated at 37 C. The macrophage monolayers were fixed and stained at various time intervals. L. mexicana promastigotes and sheep red blood cells were found to attach to macrophages in the presence of the drug but did not enter the cells. When the medium containing the Cytochalasin was replaced with normal medium phagocytosis of the adherent parasites and red cells followed rapidly. T. cruzi epimastigotes were found inside macrophages in both drug‐treated and drug‐free cultures although the number found to be intracellular in the latter was significantly greater. This study suggests that L. mexicana promastigotes enter macrophages by being phagocytosed, whereas T. cruzi epimastigotes can actively penetrate these cells.
The Immobilization Antigen of Paramecium aurelia is a Single Polypeptide Chain
Authors: HANSMA HELEN G. 
Published: May 2007

SYNOPSISThe immobilization antigen (i‐antigen) fraction of Paramecium aurelia syngen 4 is shown to contain a protease that is activated by mercaptoethanol. After the protease has been heat‐inactivated, the molecular weight of the i‐antigen (∼250,000 daltons) cannot be decreased by mercaptoethanol treatment. It is demonstrated that the i‐antigen is a single polypeptide chain. Reasons are also given why low molecular weight subunits were previously reported by other authors.