bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Fine Structure of the Colonial Kinetoplastid Flagellate Cephalothamnium cyclopum Stein
Authors: HITCHEN E. T. 
Published: May 2007

SYNOPSISCell structure, cell adhesion, and stalk formation have been examined by electron microscopy in the colonial flagellate, Cephalothamnium cyclopum. Each cell is obconical or spindle‐shaped, pointed posteriorly and truncated anteriorly. The cell membrane is underlain by epiplasm 0.1 μm thick in the posterior region, but bands of microtubules support the anterior region which is differentiated into a flagellar pocket, oral apparatus and contractile vacuole. Each of 2 flagella, joined a short way above their bases by an interflagellar connective, has a paraxial rod and mastigonemes. One flagellum is free and is important in food gathering while the other is recurrent and lies in a shallow groove on the ventral cell surface but projects posteriorly into the stalk. The basal bodies of these flagella are bipartite structures connected by a pair of striated rootlets with accessory microtubular fibers. The oral apparatus consists of a funnel‐shaped buccal cavity and cytostome. It is supported by helical and longitudinal microtubules and also has nearby striated and microtubular fibers. Possible roles of associated oral vesicles in relation to ingestion are discussed. A reticulate mitochondrion houses a massive kinetoplast which has a fibrillar substructure resembling that of dinoflagellate chromosomes. Adjacent flagellates adhere by laminate extensions of their posterior regions and attach by their recurrent flagella to a communally secreted stalk composed of finely fibrillar material. This study indicates that Cephalothamnium belongs in the order Kinetoplastida, and has many features in common with members of the family Bodonidae.
Fine Structure of Trypanosoma cyclops in Noncellular Cultures*
Authors: HEYWOOD PETER , WEINMAN DAVID , LEPMAN MURIEL 
Published: May 2007

SYNOPSISThe fine structure of the epimastigotes of Trypanosoma cyclops maintained in blood agar medium at 25 C is described. This organism was isolated from the Malaysian primates Macaca nemestrina and Macaca ira. A distinctive feature of T. cyclops is that it is pigmented when grown in the presence of hemoglobin. The pigment bodies apparently lack a substructure and are electron dense even in unstained sections. Most of the pigment is located posterior to the kinetoplast region but some is found adjacent and anterior to the kinetoplast. Cells from control cultures grown in medium lacking hemoglobin did not possess this type of pigment body. Similarly, pigment was not found in cells of an Indonesian trypanosome grown in medium containing hemoglobin.The cytoplasm of T. cyclops is bounded by a unit membrane which is specialized where it makes contact with the flagellum. A cytostome extends from the region of the flagellar pocket. The kinetoplast and nucleus are immediately posterior to the base of the flagellum. Transverse sections in the region of the flagellar pocket and flagellar base often reveal a group of 3 microtubules which are distinct from the pellicular microtubules.
Fine Structure of Haemoproteus columbae Kruse During Macrogametogenesis and Fertilization*
Authors: GALLUCCI BETTY B. 
Published: May 2007

SYNOPSISWhen blood is withdrawn from a pigeon (Columba livia) infected with gametocytes of Haemoproteus columbae, differentiation of the gametes begins immediately. This study examines the formation of the macrogamete and its fertilization. The first visible signs of differentiation are the elongation of the nucleus along with the appearance of an intranuclear spindle and atypical centrioles. Then maturation bodies, the products of nuclear reduction, form in both erythrocytic macrogametocytes and macrogametocytes free of their host cells.Penetration of the macrogamete by the microgamete occurs rapidly. Their plasma membranes fuse, and the microgamete's nucleus, axonemes and cytoplasm enter the macrogamete. The nucleus of the microgamete expands and migrates to lie at an angle to the macrogamete nucleus. The 2 fuse across a small area.The nuclear envelope and the plasma membrane of the zygote are a mosaic of the membranes of the 2 gametes.
Fine Structure of Haemoproteus columbae Kruse During Differentiation of the Ookinete*
Authors: GALLUCCI BETTY B. 
Published: May 2007

SYNOPSISOokinete differentiation begins in vitro∼1 hr after blood infected with mature gametocytes of Haemoproteus columbae is withdrawn from a pigeon. In the undifferentiated zygote, dense material accumulates at the point under the plasma membrane. The conoid and conoidal rings condense from this material. The nucleus is drawn out to a point with the intranuclear spindle (INS) at the peak. Atypical centrioles lie under the forming conoid in the cytoplasm next to the INS. Fibrous material under the inner membrane forms the polar ring from which subpellicular microtubules originate.One hr later the centrioles have disappeared and the nucleus has returned to the center of the organism. The conoidal complex forms the tip of a growing cytoplasmic projection, the anterior end of the ookinete. During this time an elaborate pellicle is differentiating antero‐posteriorly; crystalloid formation begins with an extensive proliferation of rough endoplasmic reticulum (ER) continuous with the outer membrane of the nuclear envelope. Crystalloid particles are formed between the lamellae of the ER and collected in a sphere that is later partially surrounded by a small amount of ER.Ookinetes, differentiated 2 hr longer than the ookinetes in vitro, were obtained from the gut of the pigeon fly, Pseudolynchia maura. The differentiated pellicle of these ookinetes consists of a plasma membrane, an inner membrane layer composed of 2 appressed membranes, and in the anterior end, an electron‐opaque lamina immediately under the inner membrane. Anterior to the polar ring, this lamina forms a canopy which, posteriorly, is drawn out into projecting ribs which diminish and disappear in the first third of the organism. Fifty to 60 subpellicular microtubules insert on the polar ring.Ookinetes differentiated in vitro were no more than 4 hr old. They lacked micronemes and retained a pellicular cytostome and “internal cytostomes.” The differentiation of micronemes probably occurs at a later time because they are visible after 6 hr in ookinetes in the fly gut. So many degenerating organisms appeared in vitro after 5 hr that this material was discarded.
Fine Structure of Differentiating Oocysts and Mature Sporozoites of Haemoproteus metchnikovi in its Intermediate Host Chrysops callidus*
Authors: STERLING CHARLES R. , DeGIUSTI DOMINIC L. 
Published: May 2007

SYNOPSISThe fine structure of the sporogonic stages of Haemoproteus metchnikovi has been investigated by electron microscopy. Young oocysts are found beneath the basement membrane of midgut epithelial cells. These eventually protrude outward into the haemocoel space and are surrounded by a distinct oocyst capsule. Sporozoite formation begins with a subcapsular vacuolation. Evagination of the oocyst cytoplasm occurs in regions of membrane thickenings and 100–200 sporozoites are formed about a single sporoblastoid body. Remnants of the ookinete pellicle can be observed in maturing oocysts and always are found in the residual body. The fine structure of the mature sporozoite is essentially similar to that which has been described for other haemosporidia and a spherical body is described in association with the mitochondrion of the sporozoite. The sporogonic stages of H. metchnikovi have features common to the sporogonic stages of Plasmodium and Leucocytozoon that are not held in common by the latter 2 genera, including pattern of sporozoite formation and number of sporozoites formed, the presence of a cytostome and of “crystalloid” in the sporozoite.
Phototaxis by the Dinoflagellate Gymnodinium splendens Lebour*
Authors: FORWARD RICHARD B. 
Published: May 2007

SYNOPSISA microscope‐television system was used to monitor quantitatively the behavior of Gymnodinium splendens Lebour in response to light. The predominant behavioral sequence upon stimulation is (a) an initial 2–5 sec cessation of movement (stop‐response) followed by (b) positive phototaxis. The action spectra for each response are identical, having maxima at 450 and 280 nm. Upon measuring the percent response to a range of stimulus intensities, it is apparent that a stop‐response is not a behavioral prerequisite for phototaxis. An identical circadian rhythm in photoresponsiveness is observed for phototaxis and for the stop‐response with greatest light sensitivity occurring during the first 4 hr of the entrained light period. The implication of phototactic sensitivity and the phototactic circadian rhythm in diurnal vertical migration is discussed.
Inhibition by Several Standard Antiprotozoal Drugs of Growth and O2 Uptake of Cells and Particulate Preparations of a Leptomonas*
Authors: GOLDBERG BURT , LAMBROS CHRIS , BACCHI CYRUS J. , HUTNER S. H. 
Published: May 2007

SYNOPSISDrug sensitivities of a lower trypanosomatid, Leptomonas sp. from the hemipteran Dysdercus, to antitrypanosomatid agents were estimated by growth inhibition and inhibition of polarographically measured O2 uptake of cells and particulate fractions. Several standard trypanocides, antimalarials, and electron‐transport inhibitors were used. Acriflavine, quinacrine, primaquine, pentamidine, and ethidium, each at ∼1 mM, inhibited cellular O2 uptake by 50% after 3‐hr incubation. Suramin and melarsen were inactive. Crude particulate fractions oxidized L‐α‐glycerophosphate at 80% the rate of succinate oxidation and L‐proline at 55% the succinate rate, leading to choice of succinate as standard respiratory substrate. Concentrations for 50% inhibition of growth were (μg/ml): ethidium bromide 0.009, acriflavine HCl 0.12, Antrycide 0.83, pentamidine diisethionate 1.5, and stilbamidine isethionate 1.1. Possible use of this trypanosomatid as model organism for screening antitrypanosomatid agents, and use of ethidium and acriflavine as initial model compounds are discussed.
Specificity of Amino Acid Transport in Trypanosoma equiperdum*
Authors: RUFF MICHAEL D. , READ CLARK P. 
Published: May 2007

SYNOPSISUptake of [14C] alanine, arginine, glutamic acid and phenylalanine by Trypanosoma equiperdum occurred by both a mediated mechanism and diffusion. Twenty amino acids were studied as inhibitors of absorption of the above amino acids. Results suggested that at least 4 distinct transport loci are involved in amino acid transport. These 4 loci have overlapping affinities for amino acids and seem to be involved, respectively, in the absorption of (a) arginine and phenylalanine; (b) arginine; (c) alanine, phenylalanine, and glutamic acid; (d) glutamic acid. The data also showed that multiple sites for substrate binding occur on each of 2 transport systems.
Stentor tartari sp. n. from India
Authors: MURTHY K. V. NARAYANA , BAI A. R. KASTURI 
Published: May 2007

SYNOPSISA species of Stenior isolated from freshwater ponds and tanks in and around Bangalore, India, showed striking differences from those that have been described so far. The ciliate is red in color and has 2 spherical macronuclei and 2 small micronuclei. On the basis of the nuclear apparatus and pigmentation of the body, it is believed to be a new species, named in honor of Professor Vance Tartar as Stentor tartari. n. sp.
Simple Nutrition of Crithidia deanei, a Reduviid Trypanosomatid with an Endosymbiont*
Authors: MUNDIM MARIA HERMELINDA , ROITMAN ISAAC , HERMANS MARIA A. , KITAJIMA ELLIOT W. 
Published: May 2007

SYNOPSISCrithidia deanei from the reduviid hemipteron, Zelus leucogrammus, unlike most lower trypanosomatids cultivated in defined medium, required only 2 amino acids, methionine and tyrosine; only 4 vitamins, folic acid, thiamine, biotin, and nicotinamide; and neither hemin nor a purine source. Electron microscopy reveals an endosymbiont, probably bacterial, which presumably provides the other basic trypanosomatid essential nutrients.
Spore Dimorphism in a Microsporidan Isolate*
Authors: FOWLER JERRY L. , REEVES ELDON L. 
Published: May 2007

SYNOPSISA microsporidan isolate currently considered to represent a mixed infection of Nosema necatrix Kramer, 1965 and Thelohania diazoma Kramer, 1965 was subjected to cultivation in hosts held at various temperatures. The ratio of the Nosema (monospore) to the Thelohania (octospore) forms at these temperatures was found to vary from 1:1 at 16 C to 1:0 at 32 C. Isolation technics using mechanical, temperature and temporal methods separated monosporous from octosporous forms for inoculation purposes. However, microscopic examination of hosts receiving these inocula revealed the presence of both monospores and octospores. Electrophoretic analysis of monospores and monospore‐octospore mixtures indicated equivalent hydrophobic protein spectra. These observations suggest that this isolate has the ability to produce either single spores or spores in groups of eight. This microsporidan was not considered a member of the genus Stempellia since spores in groups of 2 or 4 were not observed. Retention of the name Nosema necatrix Kramer is suggested.
Automatic Cell Counting in Continuous Flow Cultures of Tetrahymena pyriformis*
Authors: RASMUSSEN LEIF , COHR KARL‐HEINZ , BUHSE H. E. , ZEUTHEN ERIK 
Published: May 2007

SYNOPSISThis report describes an electronic cell counter constructed for determining cell number in cultures of the ciliate, Tetrahymena pyriformis. The culture chamber has been equipped with a device which determines the number of cells per unit volume and records the number automatically. As cell multiplication is unaffected by the counting procedure the cells are returned to the culture. Furthermore, keeping the culture volume constant we have arranged a continuous flow of fresh nutrient medium through the culture chamber and thus established conditions under which cell multiplication has continued for months while determinations of cell concentrations have been recorded every 10 min. Since the culture volume has been small, ∼25 ml, growth studies utilizing this method require less than one liter of fresh medium per week in spite of the fast multiplication (9 generations per 24 hr) occurring in cultures of Tetrahymena pyriformis under optimal conditions.
Growth of the Peritrich Opercularia coarctata in Axenic Culture*
Authors: McLAUGHLIN DAVID , JOHNSON GLEN R. , BRADLEY CAROLE J. 
Published: May 2007

SYNOPSISA synthetic medium for Opercularia coarctata was developed that contains 20 amino acids, 10 vitamins, an 8‐component balanced salt solution, Fe2(SO4)3·(NH4)2SO4·24H2O, Tween 80, stigmasterol, a 7‐component nucleic acid mixture, phenol red as an indicator, and 2,500 U.S.P. units/ml penicillin to maintain sterility. This medium supported axenic survival for 96 hr. Multiple supplements of thioctic acid, niacin, niacinamide, inositol, PABA, oleic acid, and Fe(NO3)2·9H2O instead of Fe2(SO4)3·(NH4)2SO4·24H2O coverted the survival medium into a growth medium, which permitted 36–45 days continuous cultivation of populations in excess of 4 × 103 cells/3.0 ml final volume. Five generations were produced during the 48 hr logarithmic growth period. Serial transfers at 72 hr and during periods of greatest cell density produced a maximum of 8 generations 96 hr after initiation but the medium failed to sustain growth through more than 6 serial transfers. Extension of this investigation to formulating a minimal axenic medium is discussed.
A Fluid System for the Cultivation, Light Microscope Examination and Manipulation of Obligate Anaerobes*
Authors: RITTER HOPE 
Published: May 2007

SYNOPSISA chamber in tandem with oxygen‐free gas supply and gas‐collecting reservoirs constitutes a system capable of anaerobic maintenance within the range of 0.8–20 μM at 13 C. Cultures contained within the chamber portion of this system are examined through exposed oculars of a microscope otherwise sealed from room atmosphere. Materials are interchanged between the 2 atmospheres through an air lock. Shoulder‐length gloves enable all manipulations common to aerobic cultivation procedures without undue restraint.
Transfer of Photosynthetically Produced Carbohydrate from Endosymbiotic Chlorellae to Paramecium bursaria*
Authors: BROWN JACK A. , NIELSEN P. JAMES 
Published: May 2007

SYNOPSISParamecium bursaria (Ehrenberg) and an endozoic zoochlorella Chlorella conductrix (Brandt) live in a symbiotic relationship. Uptake of NaH14CO3 was studied to determine if carbohydrate products of photosynthesis are transferred to the host paramecium.Paramecium bursaria containing the algal symbionts took up NaH14CO3 but those without the algal symbionts did not. Radioactive maltose, glucose, fructose and malate were identified from the ethanolic extract of paramecia.Transfer of materials from Paramecium to Chlorella and the transfer of other materials from Chlorella to Paramecium, led to the conclusion that this is a mutualistic relationship, both organisms benefiting from the relationship.
Antigenic Makeup of Subcellular Fractions of Trypanosoma cruzi
Authors: SEGURA ELSA LEONOR , CURA ESTELA N. , PAULONE IRENE , VASQUEZ CESAR , CERISOLA JOSE A. 
Published: May 2007

SYNOPSISTrypanosoma cruzi epimastigotes from cultures were separated into nuclear, mitochondrial, lysosomal, microsomal, and cell‐sap fractions. Enzymic and ultrastructutal controls served to determine the cleanness of separation. The bulk of the DNA was in the nuclear (78%) and mitochondrial (12%) fractions. RNA was found in microsomal (74%) and cell‐sap (14%) fractions. Marker enzyme distribution (succinic dehydrogenase, acid phosphatase, and glucose‐6‐phosphatase) was compared with their distribution in mammalian tissues. Subcellular localization of antigens by Ouchterlony tests revealed 2 specific precipitin lines in cell sap and 1 in the microsomal fraction. These antigens may prove diagnostically and immunoprotectively valuable.
The Glucose Transport System in Leishmania tropica Promastigotes*
Authors: SCHAEFER FRANK W. , MARTIN ELMER , MUKKADA ANTONY J. 
Published: May 2007

SYNOPSISTransport of glucose by Leishmania tropica promastigotes was measured by the uptake of the nonutilizable glucose analog, 2‐deoxy‐D‐glucose (2‐DOG), using the rapid filtration method. Both D‐glucose and 2‐DOG show identical rates of initial uptake. Intracellular 2‐DOG readily exchanges with extracellular D‐glucose and 2‐DOG uptake is competitively inhibited by D‐glucose. These observations suggest that both sugars are taken up by the same system. Neither the glucose analog α‐methyl‐D‐glucoside (α‐MG) nor 3‐0‐methyl glucose (3‐0‐MG) is taken up to any appreciable extent. Transport of 2‐DOG shows saturation kinetics with a Vmax of 3.2 nmoles/mg cells/min and a Km of 0.16 mM. There is thus a stereospecific, carrier‐mediated transport system for glucose uptake in L. tropica. About 2/3 of the intracellular pool following transport consists of 2‐deoxy‐D‐glucose phosphate (2‐DOG‐P) and the remainder is free, unaltered 2‐DOG.
Studies on the Storage Polysaccharides of the Coccidia Eimeria bovis and Eimeria stiedai
Authors: RYLEY JOHN F. , GORDON RONALD W. , STARK J. ROGER 
Published: May 2007

SYNOPSISPolysaccharides have been isolated from Eimeria bovis and E. stiedai by the use of alkali. The purified polysaccharides stain purple with iodine and have been shown by chemical and enzymic means to be amylopectin. The storage amylopectins of these coccidia differ slightly from typical plant amylopectins in their fine structure.
Nucleic Acid Precursor Incorporation by Eimeria nieschulzi (Protozoa: Apicomplexa) and Jejunal Villus Epithelium*
Authors: MAYBERRY LILLIAN F. , MARQUARDT WILLIAM C. 
Published: May 2007

SYNOPSISAutoradiography was used to investigate incorporation of tritiated adenine, adenosine, guanosine and thymidine by Eimeria nieschulzi and rat jejunal villus epithelial cells. At 2 1/2 days postinoculation, parasitized and control tissues were incubated for 20 min in oxygenated Tyrode's solution (37 C, pH 7.5) containing 30 μCi/ml of each nucleic acid precursor. Treatment of tissues with ribonuclease revealed that E. nieschulzi incorporated label from [3H]adenine primarily into RNA while that from [3H]adenosine and [3H]guanosine was present mainly in DNA. Label from [3H]thymidine was not utilized by parasites. Host villus epithelial cells incorporated label from [3H]purines primarily into RNA. Labeled cytoplasmic RNA was significantly increased in parasitized cells after incubation in [3H]adenine. Tritiated nuclear RNA and cytoplasmic RNA were significantly decreased in parasitized cells after incubation in [3H]adenosine. Incorporation of label from [3H]guanosine was similar for parasitized and control cells. A small quantity of label from each [3H]precursor was incorporated into DNA of villus epithelial cell nuclei.
Morphometric Studies of Mitochondria in Tetrahymena pyriformis Exposed to Chloramphenicol or Ethidium Bromide*
Authors: KAY EDWIN , ROHATGI KALPANA , KRAWIEC STEVEN 
Published: May 2007

SYNOPSISCultures of Tetrahymena pyriformis strain ST were exposed to 300 μg chloramphenicol/ml or 15 μg ethidium bromide/ml for 48 hr. Qualitative assessments of electron micrographs reveal that the abundance of mitochondrial cristae decreases greatly. By equating the spatial characteristics of the organism with those of a prolate spheroid, the distribution and abundance of mitochondria were quantified. Such characterizations reveal that the size of individual mitochondria decreases by 35–60% and that the number of mitochondria/cell increases ∼8 fold. The observations are discussed in terms of coordinated mitochondrial and nuclear genetic activities.
Etude Ultrastructurale de Différents Types de Kystes d'Opalines
Authors: MIGNOT JEAN‐PIERRE , BRUGEROLLE GUY 
Published: May 2007

RESUMEDeux types de structure kystique ont été observés au microscope éectronique. Dans le ler, qui correspond aux kystes d'infection ou gamontokystes, la cellule est relativement libre dans l'enveloppe kystique. Celle‐ci est formée de 2 couches distinctes d'inégale épaisseur (ectokyste, endokyste) sécrétées par la cellule et doublées intérieurement par un mince feuillet cytoplasmique dûà une extension des plis cuticulaires. C'est la seule modification du cortex cellulaire.Par contre, dans le 2ème type les modifications sont beaucoup plus importantes. La cellule est étroitement accolée aux parois du kyste; crêtes et flagelles ont disparu de la surface. Cependant on retrouve leurs traces dans la région corticale, sous forme d'axonèmes intracytoplasmiques plus ou moins désorganisés et d'empilements de saccules associés à des rangées de microtubules. Ce seraient des kystes de résistance. Les structures observées dans ces derniers kystes nous permettent de discuter quelques idées sur la participation des microtubules et des systèmes membranaires à la morphogénèse du cortex des Opalines.
Differential Nuclear Coloration in Ciliates
Authors: ALONSO PILAR 
Published: May 2007

SYNOPSIS. Application of the triple stain of Grosso (methyl green‐pyronin‐orange G) to the exconjugants of different species of ciliates produces a differential coloration of their nuclei. Both the old macronucleus or its remnants and the micronuclei bind methyl green whereas the newly developing macronucleus (macronuclear anlage) has a selective affinity for the orange G present in the mixture. This finding holds true not only for hypotrichous ciliates, whose macronuclear anlagen are involved in the formation of polytene chromosomes, but also for other ciliates not included in the order Hypotrichida. Such a reaction of the new macronuclei apparently results from the presence of non‐histone (acidic) proteins associated with the nucleic acids.The staining method is fully described to provide a more general application.