bluuebunny/crossref_metadata_2025 huggingface dataset:
Ultrastructure of Cryptosporidium wrairi from the Guinea Pig
Authors: VETTERLING JOHN M. , TAKEUCHI AKIO , MADDEN PHILIP A.
Published: May 2007

SYNOPSIS. The ultrastructure of the known tissue stages of Cryptosporidium wrairi Vetterling, Jervis, Merrill, and Sprinz, 1971 parasitizing the ileum of guinea pigs is described. Young trophozoites are surrounded by 4 unit membranes, the outer 2 of host origin, the inner 2 the pellicle of the parasite. Each trophozoite contains a vesicular nucleus with a large nucleolus. Its cytoplasm contains ribosomes, but eventually fills with cisternae of the rough endoplasmic reticulum. As the trophozoite matures the area of attachment of the parasite to the host cell becomes vacuolated, with vertical membranous folds. It is apparent that the parasite acquires nourishment from the host cell thru this area of attachment. As schizonts develop, (a) multiple nuclei appear, (b) the endoplasmic reticulum enlarges, (c) the attachment zone increases in area, (d) large vacuoles, which develop as endocytotic vesicles in the attachment area, are found in the cytoplasm and (e) the inner unit membrane of the parasite pellicle is resorbed around the sides of the developing schizont. Following nuclear division, merozoites develop from the schizont by budding. Merozoites have an ultrastructure similar to that described for other coccidia except that no mitochondria, micropores, or subpellicular tubules were observed. Merozoites penetrate the epithelial cell causing invagination of the microvillar membrane and lysing it. No unit membrane is formed between the parasite and the host cell. However, the cell produces one or 2 dense bands adjacent to the parasite attachment area. The macrogamete contains a nucleus, endoplasmic reticulum, attachment zone, and large vacuoles. It also contains a variety of granules, some of which are polysaccharide. The immature microgametocyte contains multiple compact nuclei. No mature microgametocytes or zygotes were found.
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.
The Relation of Migration of Oncopeltus fasciatus to Distribution of Phytomonas elmassiani in the Eastern United States*
Authors: MCGHEE R. BARCLAY , MCGHEE ANN H.
Published: May 2007

SYNOPSIS. A total of 4,866 plants belonging to the family Asclepiadaceae was examined in the eastern part of the United States; 291 (6%) of 11 species naturally infected with Phytomonas elmassiani; 9 of these were new host records. Eight of the 9 infected species belonged to the genus Asclepias, one to Cynanchum. Infections were recorded between 25.5° and 41.0° N latitude, and from 74.0° to 90.5° west longitude. At the southernmost latitude Asclepias curassavica, an exotic annual, perennates, harbors phytomonads and is infested the year round with Oncopeltus. Usually but not always infection is correlated with the presence and abundance of insect vectors. The annual die‐back of the usually infected perennial plant hosts, the uninfected emerging vernal growth, the reservoir nidus of infected plants in the southern latitudes, and the known proclivity of O. fasciatus to migrate suggest the spread of flagellosis of Asclepiadaceae thru migration of the vector hemipteron.
Flagellar Activity of the Colony Members of Volvox aureus Ehrbg. during Light Stimulation*
Authors: HAND WILLIAM G. , HAUPT WOLFGANG
Published: May 2007

SYNOPSIS. The flagellar behavior of the colonial Volvox aureus Ehrbg. was examined by placing 1.01 μ polystyrene particles in suspension with Volvox, and recording particle movement photomicrographically. When directional light stimulation was given, flagellar activity ceased in the anterior cells of the stimulated side. Such responses create unequal driving forces on the 2 sides of the colony, so that the colony turns toward the stimulated side. Dose response studies indicated a photoresponse gradient from front to rear in the colony, anterior cells being most responsive. The mechanism of gradient formation has yet to be determined.
Trypanosoma catostomin. sp. from the White SuckerCatostomus c. commersoni(Lacépède)*
Authors: DALY JAMES J. , DeGIUSTI DOMINIC L.
Published: May 2007

SYNOPSIS.Trypanosoma catostomin. sp. is described from the blood of the white suckerCatostomus c. commersoni(Lacépède) from southeastern Michigan. Two methods of fixation, wet and dry, are compared for their effect on body measurements. The type of fixation used affects the length of the free flagellum. Significance of this finding is 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.
Defective Micronuclei and Genomic Exclusion in Selected C* Subclones of Tetrahymena1
Authors: ALLEN SALLY LYMAN , WEREMIUK SHARON L.
Published: May 2007

SYNOPSIS. C* is a structurally heterogeneous clone containing normal and crinkled cells which are amicronucleate. Selection for structurally normal subclones did not result in the genesis of a diploid cell line. The stem cell of C* appears to be aneuploid with about 4 chromosomes instead of the usual 10, and from this line cells with fewer chromosomes or without micronuclei are generated. Only cells containing a portion of the micronucleus are viable. Amicronucleate cells die. They also mate very poorly. Consequently, little difference is observed between subclones having different proportions of amicronucleate cells in their ability to generate viable offspring by genomic exclusion. Our observations are discussed in terms of the separate functions of micronucleus and macronucleus and ways in which the nuclei seem to interact.
Eimeria ontarioensis n. sp., E. confusa Joseph, 1969 and Eimeria sp. (Protozoa: Eimeriidae) from the Ontario Gray Squirrel Sciurus carolinensis*
Authors: LEE B. L. , DORNEY R. S.
Published: May 2007

SYNOPSIS. Eimerians from 27 gray squirrels Sciurus carolinensis sampled in Waterloo County were studied. Two double‐walled species, E. ontarioensis n. sp. which was piriform (36.8 × 23.5) and E. confusa Joseph which was subspherical (35.7 × 28.4), were described and compared with similar species from the genus Sciurus. Eimeria sp., ellipsoidal (24.9 × 14.4), from Ontario gray squirrels resembled E. ascotensis and E. neosciuri and was a new eimerian record from Ontario. The zoogeographic significance of E. ontarioensis n. sp. and E. sp. in North American gray squirrels is discussed.
New Species ofEimeria(Protozoa: Eimeriidae) from Malaysian Rats*
Authors: COLLEY FREDRICK C. , MULLIN STEVEN W.
Published: May 2007

SYNOPSIS.Four new species ofEimeriawere found in a survey of 255 rats of 14 species in Malaysia.E. tikusin. sp. andE. edwardsin. sp. are described from Edwards' ratRattus edwardsi.The ellipsoidal, single‐layered oocysts ofE. tikusiaverage 30.3 by 24.4μ.A micropyle is absent; a polar granule is present. Ovoid sporocysts average 14.2 by 9.8μ.A sporocyst residuum and Stieda body are present. The ovoid, 2‐layered oocysts ofE. edwardsiaverage 29.1 by 21.8μ.A micropyle is present; a polar granule is absent. Ellipsoidal to ovoid sporocysts average 14.5 by 6.5μ.A sporocyst residuum is present; Stieda body is small or absent.E. surifern. sp. is described from the red spiny ratRattus surifer.Its ellipsoidal 3‐layered oocysts average 34.7 by 24.8μ.A micropyle is absent; a polar granule is present. The ellipsoidal sporocysts average 15.4 by 9.5μ.A sporocyst residuum, Stieda body and sub‐Stieda body are present.E. sabanin. sp. is described from the long‐tailed giant ratR. sabanus.Its ellipsoidal 2‐layered oocysts average 28.5 by 21.7μ.A micropyle is absent; a polar granule is present. The ellipsoidal‐to‐ovoid sporocysts average 11.9 by 8.0μ.A sporocyst residuum and Stieda body are present.
Acanthamoeba griffini, a New Species of Marine Amoeba
Authors: SAWYER THOMAS K.
Published: May 2007

SYNOPSIS. Acanthamoeba griffini n. sp. was collected from Long Island Sound near New London, Conn. Experimental cultivation studies on agar media supplemented with Aerobacter aerogenes showed that A. griffini grew and encysted on seawater agar media ranging up to 35‰ salinity and on distilled water agar media. Cysts varied from stellate to spherical and smooth depending on the salinity of the liquid component of the medium.
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.
Coccidia from the Tiger Salamander, Ambystoma tigrinum, in Northeastern Colorado and in Northern New Mexico
Authors: DUSZYNSKI DONALD W. , RIDDLE WAYNE A. , ANDERSON DAVID R. , MEAD ROBERT W.
Published: May 2007

SYNOPSIS. Oocysts of Eimeria ambystomae Saxe, 1955, Eimeria microcapi sp. n., and Eimeria urodela sp. n. are described from the tiger salamander, Ambystoma tigrinum, collected in Colorado and New Mexico. The oocysts of E. ambystomae are ellipsoid, 29.8 × 17.3 (24–38 × 15–25) μm, and the sporocysts lanceolate, 22.6 × 5.4 (16–27 × 5–7) μm. Oocyst and sporocyst residua are present, but not a polar granule and a micropyle. The oocysts and sporocysts of E. microcapi are ellipsoid, measuring respectively 38.1 × 25.3 (35‐41 × 23‐26) μm and 18.1 × 7.4 (16‐19 × 6–8) μm. Oocyst and sporocyst residua, a micropyle (mean 3 μm), and a distinct micropyle cap (2 μm high) are present, but not a polar granule. The oocysts of E. urodela are spheroid, 22.2 (14‐26) μm, and the sporocysts lanceolate, 16.3 × 5.8 (12‐19 × 4‐7) μm. Oocyst and sporocyst residua are present, but a polar granule and a micropyle are absent.
Efficacy of Monensin or Amprolium in the Prevention of Hepatic Coccidiosis in Rabbits
Authors: FITZGERALD PAUL R.
Published: May 2007

SYNOPSIS. New Zealand White rabbits were fed monensin (Coban® Premix) or amprolium in pelleted feed as a prophylaxis against infection with Eimeria stiedai. Rabbits receiving monensin at 0.005, 0.01, or 0.02% concentrations in the feed did not become infected but ate only small amounts of pellets when the drug concentration was 0.02%. All rabbits given 0.02% amprolium in pelleted feed developed severe infections. Rabbits on “limited” (8 gm pellets per day) diets were susceptible to infection.
Development of Eimeria crandallis Honess from Sheep in Cultured Cells*
Authors: DeVOS ALBERTUS J. , HAMMOND DATUS M. , SPEER CLARENCE A.
Published: May 2007

SYNOPSIS. Cell lines of embryonic lamb trachea (LETr), lamb thyroid (LETh), and bovine liver (BEL) as well as an established cell line of Madin‐Darby bovine kidney (MDBK) were used in a study of the in vitro development of Eimeria crandallis from sheep. Excysted sporozoites were inoculated into Leighton tubes containing coverslips with monolayers of the different cell types. Coverslips were examined with phase‐contrast and interference‐contrast at various intervals up to 20 days after inoculation; thereafter the monolayers were fixed and stained in various ways. Freshly excysted sporozoites, with 2–10 spheroidal refractile bodies, entered all of the cell types in relatively small numbers; intracellular sporozoites were first seen 2 min after inoculation. After 24 hr, most intracellular sporozoites had only 1 or 2 refractile bodies. Before and during transformation of sporozoites, the nucleus and peripheral nucleolus increased markedly in size. Transformation resulted in usually spheroid but sometimes ellipsoid trophozoites. Trophozoites were seen first 3–4 days, and binucleate schizonts at 4–5 days after inoculation. Immature schizonts increased considerably in size and eventually had large numbers of nuclei. Some of the parasites became lobulated and the lobules often separated to form individual schizonts. In BEL, LETr and LETh cells, mature schizonts, up to 150 μm in diameter, were seen first 11–14 days after inoculation. The BEL cells were the most favorable for development. Merozoites were formed by a budding process from the surface of the schizonts as well as from blastophores. Some merozoites were seen leaving mature schizonts, but no further development was observed. Merozoites frequently were motile and had a sharply bent posterior end. Marked nuclear and cytoplasmic changes were observed in parasitized cells.
The Induction of Endocytosis in Starved Tetrahymena pyriformis
Authors: RICKETTS T. R.
Published: May 2007

SYNOPSIS. The formation of digestive vacuoles by starved Tetrahymena pyriformis could be induced by mixtures of latex particles and a variety of potentially digestible solutes. Latex particles themselves had little effect in inducing vacuole formation. Protein, polypeptide, and RNA were highly effective inducers, while glutamate, amino acid mixtures, polysacharides, and glucose were moderately effective. Sodium‐β‐glycerophosphate had a slight effect and sodium acetate was ineffective. The possible stimulus to endocytosis is discussed. The endocytic response to inducers does not appear to be an all‐or‐none phenomenon and varies with the concentration of inducer. The stimulatory effect for protein‐related inducers seems to be produced by a large number of stimulatory molecules acting upon a single cell and the magnitude of the response appears to be related to molecular size.
Subcellular Distribution of Aspartate Transaminase, Alanine Amino Transferase, Glutamate Dehydrogenases, and Lactate Dehydrogenase in Tetrahymena*
Authors: PORTER PAMELA , BLUM J. J. , ELROD H.
Published: May 2007

SYNOPSIS. Mitochondria and peroxisomes were isolated from homogenates of Tetrahymena pyriformis by sedimentation through a sucrose gradient. Succinate dehydrogenase was used as a mitochondrial marker; catalase and isocitrate lyase were used to mark the peroxisomal fraction. Lactate dehydrogenase, glutamate dehydrogenase, and alanine aminotransferase were found only in the mitochondrial fraction. Aspartate transaminase was found in both mitochondrial and peroxisomal fractions.
The Effects of Temperature and Heavy Water on Cell Division in Heat‐Synchronized Cells of Tetrahymena*
Authors: MONER J. G.
Published: May 2007

SYNOPSIS. A study was undertaken of the rates of cell division of heat‐synchronized cells of Tetrahymena pyriformis GL at various temperatures in water and 20, 30 and 40% heavy water. The results suggest that division rate is limited by a protein which undergoes both high and low temperature denaturation and that this protein is partially stabilized against heat‐denaturation while becoming more susceptible to cold denaturation in the presence of heavy water. Thus, the optimum temperature for division shifts upward as the heavy water concentration is increased, with a maximum shift of 1 C occurring in 40% heavy water. In addition, division activity occurs in heavy water at 34 C, a temperature at which cells kept in water are blocked. Furthermore, the sharp increase in slope seen in the low temperature portion of Arrhenius plots of the data, occurs at higher temperatures when heavy water is present. Finally, at virtually all temperatures, except the highest, heavy water has a depressive effect on division rate indicating a general inhibitory influence of deuterium‐substituted water on rate processes within the cell.
Localization of Glyoxylate Cycle Enzymes in Glyoxysomes in Euglena*
Authors: GRAVES LYNN B. , TRELEASE RICHARD N. , GRILL ALBIN , BECKER WAYNE M.
Published: May 2007

SYNOPSIS. We demonstrated previously microbodies in Euglena gracilis grown in the dark on 2‐carbon substrates. We have now established in Euglena the particulate nature of enzymes known in other organisms to be localized in microbodies (glyoxysomes and leaf peroxisomes). On a linear sucrose gradient the glyoxylate cycle enzymes band together at a nigner equilibrium density (1.20 g/cm3) than mitochondrial marker enzymes (1.17 g/cm3), establishing the existence in Euglena of glyoxysomes similar to those of higher plants. Glyoxylate (hydroxypyruvate) reductase and, under certain conditions, also glycolate dehydrogenase co‐band with the glyoxylate cycle enzymes, suggesting that Euglena glyoxysomes, like those of higher plants, may contain peroxisomal‐type enzymes. Catalase, an enzyme characteristic of microbodies from a variety of sources, was not detected in Euglena.
L'appareil de Golgi des Ciliés. Ultrastructure, particulièrement chez Paramecium
Authors: ESTEVE JEAN‐CLAUDE
Published: May 2007

SYNOPSIS

Electronmicroscopic 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

SYNOPSIS

To 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

SYNOPSIS

Mice (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

SYNOPSIS

Oxygen 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.
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.
Some Effects of Chloramphenicol and Ethidium Bromide on Tetrahymena pyriformis
Authors: ROHATGI KALPANA , KRAWIEC STEVEN
Published: May 2007

SYNOPSIS. Very similar results are obtained by the addition of 300 μg/ml chloramphenicol or of 15 μg/ml ethidium bromide to cultures of Tetrahymena pyriformis strain ST. In such cultures the exponential growth rates and the yields are reduced. Unlike the untreated ciliates, which retain the pyriform shape throughout the exponential and stationary phases, those exposed to either of the drugs become more spherical. In the control organisms progressively less surface area/unit of cell volume is exposed to the environment during the growth cycle; in the drug‐treated ciliates this pattern is reversed. Increased endogenous respiration, reduced specific activities of states 3 and 4, and reduction in the levels of cytochromes a, a3, b, and c+c1 are found in mitochondria from ciliates exposed to chloramphenicol and ethidium bromide.
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

SYNOPSIS

Entodiniomorph 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

SYNOPSIS

Trypanosoma 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

SYNOPSIS

Eimeria 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

SYNOPSIS

It 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

SYNOPSIS

Fresh‐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

SYNOPSIS

Cells 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

SYNOPSIS

Exconjugant 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

SYNOPSIS

Cyanide‐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

SYNOPSIS

A 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

SYNOPSIS

Positive 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

SYNOPSIS

Cultures 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

SYNOPSIS

Eimeria 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

SYNOPSIS

The 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

SYNOPSIS

The 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.