bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Fine Structure of the Gregarine Lankesteria culicis Parasitic in the Yellow Fever Mosquito Aedes aegypti
Authors: WALSH R. D. , CALLAWAY C. S. 
Published: May 2007

SYNOPSIS. The fine structure of the eugregarine Lankesteria culicis from the larvae of the mosquito Aedes aegypti was examined by light and electron microscopy and compared with that of other gregarines. The cell organelles found in L. culicis included a nucleus, mitochondria, Golgi‐complexes, endoplasmic reticulum, vesicles, droplets, granules and lipid bodies.The surface of L. culicis was composed of a highly differentiated membrane‐cortex, differing slightly from that of other eugregarines. This complex was limited by a unit membrane, the plasmelemma, and underlying cortical laminae which appeared to be composed of several layers. The homogeneous electrondense layer present in Pyxinoides balani was greatly diminished or absent in L. culicis.A series of laminar folds supported by ground substance and longitudinal subpellicular fibrils gave the organism's surface a ridge‐like appearance. Permanent cytostome‐like openings in the surface, which appeared to be supported by a narrow band of thickened cortex, were present as specializations of the surfacemembrane complex. The structural composition of the parasite appeared quite striking in that it was made up almost entirely of vesicles, granules, and droplets which were absent only in the area of the protomerite. The mitochondria were usually found just beneath the surface or near the nucleus. Mitochondria were also seen in the region of demarcation between the protomerite and deutomerite.
Development of Eimeria auburnensis in Cell Cultures
Authors: CLARK WAYNE N. , HAMMOND DATUS M. 
Published: May 2007

SYNOPSIS. Monolayer established cell line cultures of bovine kidney (Madin‐Darby) and human intestine (Intestine 407), as well as embryonic bovine tracheal and embryonic spleen cell line cultures were inoculated with E. auburnensis sporozoites and observed for a maximum of 22 days. Mature 1st generation schizonts developed in the kidney, tracheal and spleen cells. In the intestine cells, trophozoites were seen in 3 of 4 experiments, but schizonts were not found. Sporozoites penetrated cells, beginning within a few minutes after inoculation. Penetration was usually accomplished within 10 seconds, and the body of the sporozoite underwent a slight constriction as it passed thru the host cell membrane. Some sporozoites left cells. Numerous intracellular sporozoites were observed in kidney, tracheal and spleen cultures. Crescent bodies were seen in the parasitophorous vacuole as early as 1 day after inoculation. At this time, the nuclei of most intracellular sporozoites had changed from vesicular to compact.Beginning 4 days after inoculation, enlarged sporozoites and parasites having a sporozoite shape, but with 2‐5 nuclei, were frequently seen. These enlarged sporozoites and sporozoite‐shaped schizonts evidently transformed into trophozoites and spheroidal schizonts by means of lateral outpocketings. Few trophozoites were seen. More immature schizonts developed in kidney cells than in the other cell types. The numbers of mature schizonts observed in kidney and tracheal cells were similar, but development occurred less consistently in the latter. Few immature and mature schizonts developed in spleen cells. Mature schizonts, first seen 9 days after inoculation, were considerably smaller than those reported from calves. Some motile merozoites were seen; evidently no development beyond these occurred. The nucleus and nucleolus of host cells were enlarged; this enlargement was not as pronounced as in infections in calves. Multiple host cell nuclei were frequently observed. Degenerative changes in the cultured cells and in the parasites usually occurred, beginning 9‐17 days after inoculation; these were more pronounced in the spleen cells than in the others.
Cilia Regeneration in Stentor: Inhibition, Delay and Abnormalities Induced by Griseofulvin
Authors: MARGULIS LYNN , NEVIACKAS JAMES A. , BANERJEE SUMANA 
Published: May 2007

SYNOPSIS. Stentor coeruleus were experimentally induced to shed their membranellar bands (MB), structures consisting of rows of cilia and their basal bodies. Control stentors entirely regenerate their MB's within 8‐10 hours according to a well‐known pattern. Stentors replaced in medium containing the fungicide and mitotic spindle inhibitor griseofulvin (10‐5M) could be reversibly inhibited from regeneration for about 3 to more than 24 hours. If griseofulvin‐inhibited cells were removed and washed, they regenerated like the controls. After about one day in 10‐5M griseofulvin and at lower concentrations stentors eventually regenerated in the presence of the drug, but abnormally.Normal unshed stentors show certain minor cytological effects and are unable to divide in griseofulvin (10‐5M); however, they can be maintained swimming actively for several weeks in nonlethal concentrations of the drug. Altho some induced abnormalities persist after removal from griseofulvin, all washed cells eventually revert to normal.
The Cell Cycle in Crithidia fasciculata. Temporal Relationships between Synthesis of Deoxyribonucleic Acid in the Nucleus and in the Kinetoplast1, 2
Authors: COSGROVE WILLIAM B. , SKEEN MARIANNE J. 
Published: May 2007

SYNOPSIS. Autoradiographic technics with tritium‐labeled thymidine have been used to determine G1, S, G2 and D for the kinetoplast and the nucleus of Crithidia fasciculata at 15, 25 and 32 C. The kinetoplast completes division before the nucleus at all 3 temperatures. The S phases of both organelles occur in approximate synchrony and are approximately equal in length but the nucleus begins and completes S before the kinetoplast at the 2 lower temperatures. This relationship is reversed at 32 C. Most of the effect of temperature on generation time is due to its effect on the length of S.The results are compared with similar studies on C. luciliae, Trypanosoma mega, other protozoa and tissue cells in culture. The role of the approximate synchrony of nuclear and kinetoplastic cycles in maintenance of the kinetoplastic condition is discussed and the hypothesis is proposed that this synchrony results from the sharing by nucleus and kinetoplast of the same mechanism for the production of the deoxyribonucleotides used in replication of their respective DNAs.
Metamorphosis in Tokophrya infusionum; an Electron‐Microscope Study
Authors: HASCALL GRETCHEN K. , RUDZINSKA MARIA A. 
Published: May 2007

SYNOPSIS. In Tokophrya infusionum metamorphosis from a ciliated swimming embryo to a sessile organism with a stalk, disc, and tentacles lasts only 3 minutes. The remarkable speed of meta‐morphosis was clarified by an electron‐microscope study of embryos before and during metamorphosis. Ultrathin sections have revealed that the embryo has at the anterior end of the body a number of specialized structures, such as dense bodies containing the precursor material for the disc and stalk, and microtubules which align the dense bodies into rows leading to pit‐kite invaginations of the pellicle at the tip of the anterior end. At meta‐morphosis the embryo settles down on this end and the precursor material is released thru the pits to the outside. At the same time the body of the embryo invaginates at this end, forming a cavity which becomes deeper and narrower until it acquires the shape of a channel. The 1st drops released from the dense bodies spread out on the substrate, forming the disc. The rest of the material, secreted into the channel, solidifies there to form the stalk. It seems obvious that the channel serves as a mold for the stalk, since after completion of the stalk the channel disappears. The stalk is structureless with no limiting membrane; it is outside the boundaries of the cell. Both the stalk and disc are extra‐cellular organelles.Of the new organelles appearing at metamorphosis, only the stalk and disc are formed de novo. The electron‐microscope study disclosed that the embryo has internal parts of tentacles composed of a tube formed of microtubules. At the distal end of the microtubules is a ring of dense material. During metamorphosis the microtubules, together with the dense ring, grow out of the body, and along with them the pellicle and plasma membrane to form the external part of the tentacle.
Synchronization of Leishmania tarentolae by Hydroxyurea
Authors: SIMPSON LARRY , BRALY PATRICIA 
Published: May 2007

SYNOPSIS Leishmania tarentolae cells in brain‐heart infusion medium were partially synchronized in terms of DNA synthesis and cell division by a 10 hour period of inhibition in 200 μg/ml hydroxyurea at 27 C. Nuclear and kinetoplast DNA synthesis commenced immediately upon removal of hydroxyurea, and kinetoplast and nuclear division occurred after about 5 hr. The Index of Synchronization (3) varied from 33‐41%.A moderate decay of the synchronicity was noted by the 2nd cell cycle. Hydroxyurea was selectively lethal to S‐phase cells.
The Life Cycle of Isospora felis Wenyon, 1923, a Coccidium of the Cat*
Authors: SHAH HARISH L. 
Published: May 2007

SYNOPSIS. A pure strain of Isospora felis derived from a single oocyst was used to study the endogenous cycle. One and a half to two‐month‐old laboratory‐reared, coccidia‐free kittens were used thruout the study. The endogenous stages occurred in the epithelial cells of the distal parts of the villi in the ileum and occasionally duodenum and jejunum. All stages lay above the host cell nucleus. There were 3 asexual generations. The 1st generation schizonts were 11–30 by 10–23 μ when mature and contained 16–17 banana‐shaped merozoites 11–15 by 3–5 μ. They became mature in 96 or sometimes in 120 hours. The 1st generation merozoites entered new host cells, rounded up and formed 2nd generation schizonts. These formed within themselves 2–10 or more spindle‐shaped bodies resembling 1st generation merozoites in shape and size. These were 2nd generation merozoites. They were uninucleate 120 hours after inoculation, but by 144 hours they became larger, multinucleate and some lost their elongate shape and became ovoid. They were then 3rd generation schizonts. They were 12–16 by 4–5 μ. Each formed up to 6 or more banana‐shaped merozoites 6–8 by 1–2 μ. The 3rd generation schizonts and merozoites developed within the same host cell and parasitophorous vacuole as the 2nd generation schizonts and merozoites. Mature schizonts containing only 3rd generation merozoites appeared 144 hours after inoculation, were most abundant 168 hours after inoculation, and might be present as late as 216 hours after inoculation. They were 14–36 by 13–22 μ and contained 36 to more than 70 merozoites.The 3rd generation merozoites entered the sexual cycle. The mature microgametocytes were 24–72 by 18–32 μ and contained a central residuum and a large number of microgametes 5–7 by 0.8 μ with 2 posteriorly‐directed flagella. The mature macrogametes were 16–22 by 8–13 μ. Gametogony occurred 144–216 hours after inoculation.The prepatent period was 168–192 hours and the patent period 10–11 days. Peak oocyst production occurred on the 6th day of the patent period.
Morphogenesis and Cortical Ultrastructure of Brooklynella hostilis, a Dysteriid Ciliate Ectoparasitic on Marine Fishes*
Authors: LOM JIŘÍ , CORLISS JOHN O. 
Published: May 2007

SYNOPSIS. Morphogenesis, and the cortical structures of Brooklynella hostilis, a cyrtophorine gymnostome ciliate ectoparasitic on marine fishes, were studied from protargol silver‐impregnated preparations and with the aid of electron microscopy. The pattern of morphogenesis of Brooklynella is close to that found in less differentiated species of the families Chlamydodontidae (e.g., in the genus Trithigmostoma) and Dysteriidae (e.g., in the genus Hartmanula). The full number of kineties in the opisthe is restored after division from a segment of the left one of the 3 kinetics producing the oral rows. The oral rows consist of a double row of kinetosomes arranged in a zig‐zag pattern; only the outer row is ciliated, the inner one being barren. However, the positions of the postciliary and transverse fibers indicate that the oral rows are not homologs of an undulating membrane but are akin to a membranelle.In association with the ventral somatic kinetosomes there are 4 postciliary fibers; a rather aberrant, transversally oriented kinetodesma; 2 microtubular, transverse fibers plus a transverse fibrousspur; and one to several ribbons of subkinetal microtubular fibers. Not directly associated with the kinetosomes are fibrous strands running subpellicularly between the kinetosomes and also deep into the cytoplasm. The cortical structures of Brooklynella are compared with those of some other groups of ciliates of about the same phylogenetic level in which the subkinetal microtubules can also be found– rhynchodine, suctorian, and chonotrich ciliates.The nasse consists of 6–8 nematodesmata not closely associated with the microtubular cytopharyngeal tube. The former have a distinctly developed densely fibrous capitulum containing barren kinetosomes which originally produced the nematodesma during stomatogenesis; the capitulum is connected by a fibrous link to the microtubular shaft. Extending from the oral rows to the capitula are fibrous structures strongly reminiscent of filamentous reticulum in hymenostome and peritrich ciliates.The structure of the posterio‐ventral glandular organelle is also described and discussed.
Observations Biologiques et Ultrastructurales sur les Selenidiidae et Leurs Conséquences sur la Systématique des Grégarinomorphes
Authors: SCHRéVEL J. 
Published: May 2007

SYNOPSIS. The taxonomic position of Selenidiidae Brasil in the class of gregarines is discussed in relation to the study of its life cycles, its possible schizogony and the fine structure of its trophozoites.The cycle of gregarines which belong to the genus Selenidium Giard is characterized by trophozoites with pendular or coiling movements, nuclear transformations in gamonts during syzygy just before cyst formation, anisogamy, sporocysts with 4 sporozoites.Schizogony of the Selenidiidae is not yet demonstrated. The “kystes á meérozoites” within the gut epithelium of Sabellaria alveolata, could be one of the stages of schizogony of S. hollandei. This sole example in our study and the absence of schizogony in numerous species, especially in S. pendula, the type species, shows that this criterion is uncertain, actually, in the definition of the order Archigregarinida Grassé. Ultrastructural studies of S. hollandei and S. pendula show that the cortical region in trophozoites of the genus Selenidium is different from that of Eugregarinida. In the Selenidiidae the epicyte is composed of longitudinal folds. Under the wall, consisting of 3 membranes there is a well‐defined pellicular fibrillar system. In S. hollandei, the trophozoite has a fibrillar formation, corresponding to a conoid in its anterior region. The trophozoites of S. hollandei and S. pendula contain anterior dense bodies or rhoptries which are very well developed. All these characteristics conform to the ultrastructural organization of the dissemination forms (merozoites, schizozoites, sporozoites):The results allow one to give a new definition of the Order Archigregarinida:Order Archigregarinida (Grassé): Gregarines with ultrastructural organization of the trophozoites similar to that of dissemination forms. Presence of a well defined pellicular fibrillar system. Intestinal parasites of polychaete worms.
Host and Parasite Interactions During Single and Concurrent Infections withEimeria nieschulziandE. separatain the Rat1
Authors: DUSZYNSKI DONALD W. 
Published: May 2007

SYNOPSIS.Some effects of 2 species ofEimeriain the rat were studied in single and concurrent infections. Groups included singly infectedE. nieschulziandE. separatacontrols (15 rats each) and 4 groups of 5 rats each infected withE. separata(shorter life cycle) at different days of an establishedE. nieschulziinfection. Experiments were conducted using inoculations of approximately 3,000, 5,000, and 7,000 sporulated oocysts of each species. Hosts showed consistently poor weight gain on day 3 postinoculation (PI) inE. separatainfections and usually showed weight loss on days 7 and/or 8 PI inE. nieschulziinfections. Spleen weights indicated that the hosts responded immunologically to both parasites. Small intestine weights increased duringE. nieschulziinfections as did cecum‐colon weights duringE. separatainfections. In severe infections both species seemed to cause pathologic change in tissues at a distance from the site of endogenous development.Fecal collections were made at 24‐hr intervals from the time of 1st inoculation till the end of patency. Patency usually began on day 7 PI forE. nieschulziand on day 4 PI forE. separatawith oocyst discharge peaking on days 8 and 5, respectively. In 2 instances, a biphasic pattern of oocyst discharge was found forE. separataduring concurrent infections. The occurrence of interspecific interactions was indicated by an increased discharge of oocysts ofE. separata, including those with the ability to sporulate, in doubly‐infected animals as compared with those in singly‐infected controls. It was suggested that the increased oocyst discharges may have resulted from additional production of merozoites during schizogony. Concurrent infections weakened the host more than single infections and this seemingly allowed more multiplication of the parasites.
Eimeria procyonis sp. n., an Isospora sp., and a Redescription of E. nuttalli Yakimoff and Matikaschwili, 1932 (Protozoa: Eimeriidae) from the American Raccoon (Procyon lotor)
Authors: INABNIT RALPH , CHOBOTAR BILL , ERNST JOHN V. 
Published: May 2007

SYNOPSIS. Thirty‐two of 48 raccoons examined were infected with a previously undescribed species of Eimeria which is herein named E. procyonis. Of the 32 infected animals, 10 also harbored E. nuttalli and 1 had Isospora sp. oocysts.The ellipsoid to ovoid oocysts of E. procyonis measured 23.4 × 18.0 (16–29 × 13–24) μm; its sporocysts measured 12.1 × 9.3 (11.5–15 × 7–10) μm, each containing a slightly flattened substiedal body. The sporocyst residuum consisted of numerous scattered granules each ∼1 μm in diameter. The oocyst wall was double‐layered. The outer layer appeared rough and pitted, measuring 1.5 μm, except at the micropyle where it was 1 μm thick.The oocysts of the Isospora sp. measured 16.8 × 13.7 (16–18.5 × 12.5–15.5) μm. The wall consisted of a single layer ∼0.5 μm thick. The sporocysts measured 11.2 × 9.1 (9.5–11.5 × 8–10) μm, and each contained 4 elongate sporozoites. The oocysts of E. nuttalli measured 17.5 × 13.6 (12‐21 × 11‐15) μm, with a smooth single‐layered wall approximately 0.7 μm thick. The sporocysts measured 12.2 × 7.1 (9‐13 × 5.5–11) μm. Each sporocyst had a thin, dark, Stieda body and the sporocyst residuum consisted of many fine granules.
L'appareil de Golgi des Ciliés. Ultrastructure, particulièrement chez Paramecium
Authors: ESTEVE JEAN‐CLAUDE 
Published: May 2007

SYNOPSISElectronmicroscopic study of Coleps, Colpidium, Stylonychia, and especially of Paramecium confirmed the presence of the Golgi complex in these fresh‐water ciliates. The complex consisted of numerous dictyosomes scattered throughout the cytoplasm. Each dictyosome included a few flat, partly reticulated saccules lying parallel to a cistern of rough endoplasmic reticulum which was free of ribosomes on the side exposed to the dictyosome. A unique layer of vesicles, characterized by constant size and a thick wall, separated the endoplasmic reticulum from the dictyosomes. The vesicles could be regarded as transition vesicles. Coated vesicles were seen in continuity with some of the flattened saccules. The possible role of the Golgi complex in the physiology of ciliates is discussed.
Ciliary Proteins and Cytodifferentiation in Stentor coeruleus*
Authors: PLAPP FRED V. , BURCHILL BROWER R. 
Published: May 2007

SYNOPSISTo elucidate further the molecular events required for cytodifferentiation in Stentor coeruleus, the effects of several chemical metabolic inhibitors were tested on the outgrowth in situ of the membranellar cilia of the oral feeding organelle. The chemicals used included several inhibitors of cytoplasmic and mitochondrial protein synthesis (cycloheximide, emetine, and chloramphenicol), and an antimitotic agent (colchicine). Ciliary growth was affected only by colchicine, suggesting that a pool of “ciliary proteins” exists in interphase Stentor of sufficient size to permit complete reformation of the membranellar cilia. The implication of these observations to an understanding of the more complicated process of oral regeneration is discussed.
The Effects of Bacterial Endotoxin on the Infection of Mice with Trypanosoma cruzi*
Authors: KIERSZENBAUM FELIPE , SAAVEDRA LIDIA E. 
Published: May 2007

SYNOPSISMice (Rockland strain) infected with Trypanosoma cruzi strain Tulahuén were treated with Escherichia coli endotoxin before, simultaneously with, and after inoculation of the parasites. The peak parasitemias of endotoxin‐treated mice were higher than those of nontreated infected animals, regardless of the time of endotoxin administration. Peak parasitemias occurred at the same time in infected nontreated mice as in animals given endotoxin before or simultaneously with the trypanosomes. If endotoxin was administered 24 hr after the infection, a delay in the peak parasitemia was noted. Changes in the survival time were not observed unless endotoxin was given 24 hr postinfection. Infected mice had an increasing susceptibility to the lethal effect of endotoxin. The LD50 of endotoxin decreased from 675 μg for normal mice to 230, 92, and 18 μg for infected animals 1, 3, and 8 days after the infection, respectively. In the infected mice, the endotoxin‐detoxifying ability of the spleen was found to be impaired.
Proline Metabolism in Leishmania donovani Promastigotes*
Authors: KRASSNER S. M. , FLORY B. 
Published: May 2007

SYNOPSISOxygen uptake of Leishmania donovani culture promastigotes was stimulated by L‐proline and to a lesser extent by L‐glutamate and L‐arginine. L‐proline reversed partially KCN‐induced inhibition of respiration and completely, inhibition caused by malonate. Labeled proline, glutamate, alanine, and arginine were detected by thin layer chromatography in the free amino acid pool from cells incubated with L‐proline‐14C. Labeled tricarboxylic acid cycle intermediates, α‐ketoglutarate, succinate, fumarate, malate, and oxaloacetate, also were found by this method in extracts from organisms incubated with L‐proline‐14C which contained also pyruvate. Cells incubated with malic acid‐14C contained labeled alanine, glutamate, and arginine. Labeled L‐proline was not found in promastigotes incubated with D‐glucose‐14C, although arginine, glutamate, and alanine were detected in extracts from these organisms. Indirect evidence for the presence of a NADP‐dependent malic enzyme was obtained by Ochoa's method. All results suggest the presence of a proline‐glutamate interconversion pathway in L. donovani promastigote culture forms.