bluuebunny/crossref_metadata_2025 huggingface dataset:
Fine Structure of the Neogregarine Farinocystis tribolii Weiser, 1953. Developmental Stages in Merogony.
Authors: ŽIŽKA ZDENĚK
Published: May 2007

SYNOPSIS. The fine structure of schizonts and free merozoites of the neogregarine Farinocystis tribolii Weiser, and their development in the fat body of larval Tribolium castaneum were studied.

The surface of a multinucleate schizont and that of a uninucleate merozoite is covered by a double‐layered membrane. Rhoptries and micronemes are present. The cytoplasm is packed with ribosomes and also contains dark bodies. Mitochondria are of the vesicular type. The spherical nucleus of the schizont and merozoite contains a large nucleolus. The anterior end of the merozoite has a typical conoidal complex composed of a conoid and a polar ring with 22 subpellicular mirotubules projecting from it.

New findings are a membranous septum across the body of the merozoite at 2/3 of its length below the nucleus and a highly osmiophilic spiral structure in the perinuclear space close to the Golgi complex. In addition, we found some “developmental stages” of the latter structure.
Comparative Study of Ultrastructure of Interlamellar and Intralamellar Types of Henneguya exilis Kudo from Channel Catfish*†
Authors: CURRENT WILLIAM L. , JANOVY JOHN
Published: May 2007

SYNOPSIS. The inter‐ and intralamellar types of Henneguya exilis Kudo (Myxosporida) infections from channel catfish are similar in spore structure and sporogenesis, but differ in the structure of their plasmodium wall and surface coat and in their relationship with the host cells. The 2 clinical types differ also in the sites of development and growth patterns of plasmodia within a gill filament. Interlamellar plasmodia are limited by 2 outer unit membranes which give rise to both single‐and double‐membraned pinocytic canals. Intralamellar plasmodia are limited by a single outer unit membrane which gives rise to single‐membraned pinocytic canals. Interlamellar plasmodia are covered by a fine granular coat of highly variable thicknesses; in some regions there is direct contact between the parasite and cells of the host. There is some evidence that host cell cytoplasm as well as interstitial material are taken in by interlamellar plasmodia. In contrast, intralamellar plasmodia are covered by a fine granular coat of almost uniform thickness, which prevents direct contact between the parasite and cells of the host; probably only interstitial material is taken by these plasmodia.
Myxosporidan Infections in Some Fishes of Iowa*
Authors: MITCHELL LAWRENCE G.
Published: May 2007

SYNOPSIS. A survey of 617 specimens of fishes representing 8 families in Iowa revealed coelozoic infections by Chloromyxum catostomi, Chloromyxum trijugum, and Myxidium macrocapsulare and histozoic infections by Henneguya exilis and Myxobolus spp. The trophozoite of M. macrocapsulare is described. Descriptive notes supplementary to previous literature are provided for the 3 coelozoic species.
Genetic Analysis of Trichocyst Discharge of the Wild Stocks of Paramecium tetraurelia*
Authors: NYBERG DENNIS
Published: May 2007

SYNOPSIS. Aberrant discharge of trichocysts in response to picric acid occurs in 8 of the 28 wild stocks of Paramecium tetraurelia. There are at least 4 distinguishable phenotypes: nondischarge, stocks 139, 163, 169, and 242; temperature‐sensitive nondischarge, stock 126; leaky nondischarge, stock 203; and a clonally unstable phenotype, stocks 146 and 148. From each of these stocks a single recessive gene causing nondischarge has been isolated by backcrosses to stock 51. The original stocks 126, 146, and 148 possess other genes which affect the extracted genes. The copper resistance locus is ∼ 10 centiMorgans from nd169 and nd242, but none of the other nondischarge genes are linked to 6 marker loci. The genes nd169 and nd242 are only 0.5 centiMorgans apart making them the closest known pair of loci in P. tetraurelia. The genes nd126 and nd242 are distinguishable alleles at the same locus and the genes nd146 and nd148 are apparently identical alleles. The large number of loci involved in producing a similar phenotype in different stocks supports the idea that mutation is much more important than gene flow in this highly inbreeding species.
Effects of Methylglyoxal bis(Guanylhydrazone) on Trypanosomatid Flagellates: Inhibition of Growth and Nucleoside Incorporation in Trypanosoma brucei*
Authors: CHANG K.‐P. , STEIGER R. F. , DAVE C. , CHENG Y.‐C.
Published: May 2007

SYNOPSIS. Methylglyoxal bis(guanylhydrazone) (MGBG) at 0.5 mm had little effect in vitro on Blastocrithidia culicis, Crithidia oncopelti, and Leishmania spp., but completely inhibited growth of Trypanosoma brucei. Inhibition became irreversible after a 3‐h exposure of T. brucei culture procyclics. Treated organisms remained motile, but failed to divide. Polyamines, spermidine, and spermine, did not reverse the anti‐trypanosome action of MGBG (preloading of cells or concurrent administration). Two intraperitoneal injections of the drug at a concentration of 50 mg kg body weight at a 1‐day interval greatly reduced the parasitemia of T. brucei and T. congolense in rats. Trypanosome infections, however, relapsed and killed the animals in 6 days after treatment. It was evident from the results of tracer experiments with T. brucei that MGBG significantly lowered incorporation of [3H]thymidine by culture procyclics and of [3H]uridine by bloodstream forms; in both stages [3H]leucine incorporation was only slightly inhibited. It is suggested that MGBG interferes with nucleoside incorporation by Trypanosoma and that its mode of action is different in bloodstream and culture procyclics.
Wenyonella baghdadensis sp. n. from the Bandicoot Rat Nesokia indica in the Baghdad Area
Authors: MIRZA MIRZA Y. , AL‐RAWAS ADNAN Y.
Published: May 2007

SYNOPSIS. Oocysts of Wenyonella baghdadensis sp. n. were found in the feces of 2 of 12 bandicoot rats Nesokia indica Gray & Hardwicke from the Baghdad area. Sporulated oocysts were subspherical to broadly ellipsoidal, 25.4 (18–22) × 20.8 (15–28) μm, with a 2‐layered wall, the outer wall being mammillated, without micropyle, micropylar cap, residuum, or polar granule. Sporozoites were ovoid, 11.8 (9–15) × 8.4 (6–10) μm, with Stieda body and residuum. Two sporozoites in each sporocyst were elongate, with granular cytoplasm and a refractile globule, the other 2 were bean‐shaped, without granules or refractile globule. Sporulation time equalled 3 days at 22–24 C. Entamoeba coli and Giardia sp. cysts were also found in 3 rats each.
Preuves Cinétiques de l'Existence d'une Période de Compétence pour la Transformation Microstome‐Macrostome dans le Cycle Cellulaire de Tetrahymena paravorax
Authors: METENIER GUY
Published: May 2007

RÉSUMÉ. Des expérimentations portant sur des cellules isolées ont montré que 77% des microstomes de Tetrahymena paravorax, prélevés au hasard dans des cultures en phase logarithmique de croissance, se transforment directement en macrostomes en présence de “stomatine.” Ces macrostomes apparaissent à des moments variés entre 1,5 et 9 h après l'addition de la stomatine (“point 50% de transformations” vers 2,5 h). La compétence pour le remplacement oral est en relation avec la position dans le cycle cellulaire. Les pourcentages de transformation les plus élevés sont observés avec les populations testées pendant la première moitié de la période moyenne d'interfission. La formation des macrostomes est d'autant plus rapide que l'ǎge initial des microstomes est plus proche du point médian du cycle cellulaire (“point de compétence”). Dans la seconde moitié de ce cycle, le temps moyen de transformation reste à peu près constant, mais le pourcentage de divisions augmente: le “point de transition” (50% de divisions) se trouve au début d'une phase terminale représentant 19–20% de la durée totale du cycle. La transformation des produits de bipartition antérieur et postérieur est nettement asynchrone: dans la majorité des paires cellulaires, l'opisthe se transforme avant le proter. Les cellules‐soeurs se divisent aussi de manière asynchrone: le temps de génération du proter est plus long que celui de l'opisthe.

Le problème de l'acquisition de la compétence pour le changement de phénotype est discuté en envisageant les corrélations éventuelles avec certains processus majeurs du cycle cellulaire.

SYNOPSIS. Seventy‐seven percent of the microstomes of Tetrahymena paravorax taken from random samples of log‐phase cultures transform directly into macrostomes in the presence of “stomatin.” These macrostomes appear between 1.5 and 9 h after addition of stomatin (“50% transformation point,”∼ 2.5 h). Competence for oral replacement is related to the position in the cell cycle. The highest percentages of transformation are observed in populations tested during the first half of the mean interfission period. Formation of macrostomes is more rapid when the initial age of the microstomes is nearer to the midpoint of the cell cycle (“competence point”). In the 2nd half of this cycle, the mean transformation time remains approximately constant, but the percentage of cells undergoing division is increasing. The “transition point” (50% divided cells) is found at the beginning of a terminal phase which accounts for 19–20% of the cell cycle. Transformation of anterior and posterior fission products is fairly asynchronous; in the majority of individual pairs, the opisthe is transformed before the proter. The daughter cells also divide asynchronously, the generation time of the proter being longer than that of the opisthe. The problem of acquisition of competence for phenotypic change is discussed in light of possible correlations with certain major processes of the cell cycle.
Correlation of Infectivity and Concanavalin A Agglutinability of Algae Exsymbiotic from Paramecium bursaria
Authors: WEIS DALE S.
Published: May 2007

SYNOPSIS. Eighteen strains of algae, including 17 exsymbiotic from Paramecium bursaria, were tested for infectivity for P. bursaria, syngen 2 aposymbiotes, and Concanavalin A (Con A) agglutinability. All 6 infective algal strains were relatively resistant to agglutination by Con A, suggesting that algal surface characteristics are correlated with infectivity. Among the noninfective strains, high and low agglutinability were about equally represented, indicating that the Con A titer alone is not a sufficient indicator of infectivity. It is suggested that noninfective algal strains are the progeny of mutations occurring within the endozoic population and fortuitously selected by the external culture medium.
The Effect of Eimeria nieschulzi Infection on Leukocyte Levels in the Rat*
Authors: McQUISTION THOMAS E. , SCHURR KARL M.
Published: May 2007

SYNOPSIS. Rats inoculated with 10,000 sporulated oocysts of Eimeria nieschulzi had significantly higher total leukocyte counts on postinoculation days (PI) 1, 5, 6 and 7 when compared to control rats. Relative and absolute neutrophil counts increased concomitantly with a decrease in the relative lymphocyte levels in E. nieschulzi‐infected rats on PI day 7. Absolute and relative neutrophil counts in infected rats on PI days 7 and 8 were closely correlated with the host's total oocyst discharge. The E. nieschulzi infection had no significant effect on the relative or absolute levels of monocytes or eosinophils. The described changes in leukocyte levels were not paralleled by a significant change in the erythrocyte count.
Effect of Immunization of Cats with Isospora felis and BCG on Immunity to Reexcretion of Toxoplasma gondii Oocysts*
Authors: DUBEY J. P.
Published: May 2007

SYNOPSIS. The effect of pretreatment with Isospora felis and bacillus Calmette‐Guérin (BCG) on the reexcretion of Toxoplasma gondii occysts was studied in 16 coccidia‐free cats. The following conclusions were drawn: (A) Chronically T. gondii‐infected cats reexcreted T. gondii oocysts after superinfection with I. felis, and this reexcretion was prevented in cats infected with I. felis before T. gondii infection. (B) Administration of BCG before Toxoplasma infection had no apparent effect on the outcome of the infection.
Effect of Colchicine on Cell Membrane and on Biopterin Transport in Crithidia fasciculata*
Authors: REMBOLD HEINZ , LANGENBACH TOMAZ
Published: May 2007

SYNOPSIS. Incorporation of 14C‐labeled biopterin into Crithidia fasciculata was inhibited by 1 mM colchicine or lumicolchicine. These substances do not penetrate the cell membrane, hence they cannot interact with the subpellicular microtubules. In view of this, interference of colchicine with biopterin transport must occur on the outer surface of the cell membrane. Binding of colchicine to Crithidia was not temperature‐dependent and did not exhibit saturation kinetics. These facts exclude a binding as in the case of tubulin, or similar proteins which may be present in the membrane. The results suggest an inhibition reflecting steric hindrance of the biopterin carrier system.
Differentiation‐Dependent Decline of DNA Synthetic Activities in Naegleria gruberi
Authors: YUYAMA SHUHEI , CORFF SONDRA
Published: May 2007

SYNOPSIS. DNA of Naegleria gruberi strain NEG, grown in axenic culture, forms a band at a density of 1.6912 in CsCl gradient and has a GC content of 31.8%. Incorporation of [3H]thymidine into DNA is much reduced in differentiating Naegleria immediately after the stimulation to transforms, primarily because of the reduction in thymidine uptake by differentiating cells. In addition, there is a marked decrease in the rate of incorporation of [3H]thymidine and [3H]uracil into DNA at from 45 to 60 min after the stimulation for differentiation. This decrease in the rate of precursor incorporation into DNA appears to be due to the differentiation‐dependent cessation of nuclear DNA synthesis. The differentiated phenotype (the flagellate) emerges at ∼ 70 min after the stimulation, and over 90% of the population differentiates within the next 30 min. Synthesis of mitochondrial DNA is detectable until 190 min after the stimulation. Since the S phase of Naegleria lasts ∼ 180 min, some cells in the population must cease synthesizing nuclear DNA in the middle of the S phase.
Fine Structure of Human Malaria In Vitro*†
Authors: LANGRETH SUSAN G. , JENSEN JAMES B. , REESE ROBERT T. , TRAGER WILLIAM
Published: May 2007

SYNOPSIS. The erythrocytic cycle of the human malaria parasite, Plasmodium falciparum, was examined by electron microscopy. Three strains of parasites maintained in continuous culture in human erythrocytes were compared with in vivo infections in Aotus monkeys. The ultrastructure of P. falciparum is not altered by continuous cultivation in vitro. mitochondria contain DNA‐like filaments and some cristae at all stages of the erythrocytic life cycle. The Golgi apparatus is prominent at the schizont stage and may be involved in the formation of rhoptries. In culture, knob‐like protrusions first appear on the surface of trophozoite‐infected erythrocytes. The time of appearance of knobs on cells in vitro correlates with the life cycle stage of parasites which are sequestered from the peripheral circulation in vivo. Knob material of older parasites coalesces and forms extensions from the erythrocyte surface. Some of this material is sloughed from the host cell surface. The parasitophorous vacuole membrane breaks down in erythrocytes containing mature merozoites both in vitro and in vivo. Merozoite structure is similar to that of P. knowlesi. The immature gametocytes in culture have no knobs.
Morphological Alterations in Euglena gracilis Induced by Treatment with CTAB (Cetyltrimethylammonium Bromide) and Triton X‐100: Correlations with Effects on Photophobic Behavioral Responses*
Authors: MIKOLAJCZYK EWA , DIEHN BODO
Published: May 2007

SYNOPSIS. Treatment of Euglena gracilis with the cationic detergent CTAB at concentrations of 0.05 mM or higher selectively inhibited the ability of the cells to respond with flagellar reorientation to a sudden decrease of light intensity (step‐down photophobic response). The ability to respond similarly to an increase in light intensity (step‐up photophobic response) was unaffected even at detergent concentrations at which the step‐down response was completely inhibited. Electron microscopy of cells treated with 1.0 mM CTAB revealed selective destruction of the membrane of the reservoir and flagellum. No selective effects upon the step‐down or step‐up photophobic responses were found upon treatment of the cells with Triton X‐100.
Specificity of Rumen Ciliate Protozoa in Cattle and Sheep*
Authors: DEHORITY B. A.
Published: May 2007

SYNOPSIS. Six protozoa‐free sheep, 3 fed alfalfa hay and 3 fed a concentrate diet, were inoculated with rumen contents from a steer fed the same alfalfa hay. All 24 species of protozoa in the inoculum became established in the sheep fed alfalfa hay, while only 9 species established in the sheep fed concentrate. Percentage species composition in the alfalfa‐fed sheep was fairly similar to that of the inoculum. Rumen volumes of the alfalfa hay‐fed sheep were significantly higher than those of the concentrate‐fed sheep; however, fluid turnover rates were similar. Total protozoan numbers per ml of rumen contents were significantly higher in the concentrate‐fed sheep, but after adjustment for rumen volume, there was no significant difference in the total number of protozoa in the rumen.
Axenic Cultivation of the Cellulolytic Flagellate Trichomitopsis termopsidis (Cleveland) from the Termite Zootermopsis*
Authors: YAMIN MICHAEL A.
Published: May 2007

SYNOPSIS. Trichomitopsis termopsidis (Cleveland), a cellulolytic hindgut symbiote of the termite Zootermopsis, has been cultivated axenically under anaerobic conditions. The medium consists of cellulose, reduced glutathione, fetal calf serum, yeast extract, and autoclaved rumen fluid or autoclaved rumen bacteria, in a buffered salt solution the composition of which is based on an analysis of Zootermopsis hindgut fluid. The hindgut contents of surface‐sterilized termites were inoculated into anaerobic buffer‐containing cellulose and serum. Repeated passages yielded mixed cultures of T. termopsidis and termite hindgut bacteria. Flagellates were then inoculated into complete medium containing antibiotics, and after 2 passages, axenic cultures of T. termopsidis were obtained. Various nutritional supplements, including clarified rumen fluid or heat‐killed bacteria of several known species failed to support the growth of T. termopsidis when substituted for autoclaved rumen fluid. The flagellates did not grow when any of several carbohydrates were substituted for cellulose. Electron microscopy of flagellates from axenic cultures revealed that cellulose particles and partially digested bacteria were present in food vacuoles. No endosymbiotic bacteria were present in the cytoplasm indicating that T. termopsidis does not depend on living prokaryotes for cellulose digestion. The results suggest that T. termopsidis possesses the enzyme cellulase.
Formation of Scales in Paraphysomonas vestita and the Inhibition of Growth by Germanium Dioxide*
Authors: LEE ROBERT EDWARD
Published: May 2007

SYNOPSIS Paraphysomonas vestita (Stokes), a colorless flagellate, has silicified external scales. In this study EDAX analysis of the scales confirmed earlier experimental evidence that silicon is the major component of the scales. The scales are formed in the endoplasmic reticulum of the cytoplasm and carried to the plasmalemma in vesicles. The flagellate is euryhaline growing in a range from 2.6X seawater to near distilled water. From the salinity data it appears that Paraphysomonas vestita is the same as Paraphysomonas imperforata Lucas. A GeO2 concentration of 2.0 mg l‐1 (19.2 μM Ge) results in complete inhibition of growth.
Ultrastructure of the Somatic and Buccal Cortex of the Tetrahymenine Hymenostome Glaucoma chattoni
Authors: PECK ROBERT K.
Published: May 2007

SYNOPSIS The membranes, epiplasm, and fiber systems are described in the somatic cortex of Glaucoma chattoni strain HZ‐1. Kinetodesmal fibers, postciliary and transverse microtubular ribbons, basal microtubules, transverse fibers and transverse accessory material are associated with kinetosomes. Longitudinal microtubular ribbons and mitochondria occur interkinetally. In the buccal cortex, the membranes, epiplasm and fibers of the 3 membranelles, the paroral kinety, the ribbed wall, and the cytostome are described. Comparisons between G. chattoni and other ciliates reveal ultrastructural differences of possible systematic significance. In the somatic cortex of this and other tetrahymenines. Iongitudinal microtubular ribbons and basal microtubules occur concurrently. In the buccal cortex, alveoli are absent in tetrahymenine membranelles. A table is presented of the fiber systems associated with single somatic kinetosomes of various ciliates whose cortical ultrastructure has been studied to date.
Chemosensory Responses Toward Oxygen in Euglena gracilis*
Authors: COLOMBETTI G. , DIEHN BODO
Published: May 2007

SYNOPSIS Euglena gracilis strain Z, at a concentration of 106 cells/ml and in containers of ∽ 0.1‐mm thickness, spontaneously forms dynamic ring patterns in the dark. These patterns are modified differentially by illumination with red and with blue light. The red light effect is abolished by treatment with an inhibitor of photosynthesis. Pattern formation is apparently the result of chemophobic responses to oxygen dissolved in the medium. Euglena can respond to both negative and positive concentration gradients, depending upon the absolute magnitude of oxygen concentration. The photo‐ and chemosensory transduction systems of Euglena interact at a stage which precedes the overt expression of motor responses.
Alteration of the Tetrahymena Genome During Nuclear Differentiation*†
Authors: YAO MENG‐CHAO , GALL JOSEPH G.
Published: May 2007

Synopsis.

The DNA of the macro‐ and the micronucleus of Tetrahymena thermophila has been compared by various biochemical methods. It became evident from their thermal denaturation temperatures and buoyant densities that the 2 DNAs were very similar in overall composition. Small differences were detected when the sequence complexities of these DNAs were compared by DNA renaturation studies. The studies suggested that ˜ 10% of the micronuclear genome was lost or underrepresented in the macronucleus. Comparison of individual gene levels revealed further differences. By using the technic of gene cloning a micronuclear sequence was isolated which hybridized only with micronuclear, but not with macronuclear DNA. These results indicated the occurrence of elimination or underreplication of this sequence in the macronucleus. Gene amplification was also shown to occur. In the micronucleus only a single copy of rDNA was found integrated into the chromosome. During macro‐nuclear development, amplification was observed to occur, and the amount of rDNA to increase, until there were ˜ 200 copies per haploid genome in the mature macronucleus. all of them extrachromosomal and palindromic. The 3rd case of alteration involved a simple repeated sequence, (CCCCAA)n, present in the termini of rDNA and also in many other locations of the genome. Restriction endonuclease digestion studies revealed drastic differences in the organization of the repeats between macro‐and micronucleus. These differences may be interpreted as the results of chromosome fragmentation which occurs at every cluster of the repeats during macronuclear development. The relationship between this event and gene amplification and elimination is discussed.
Facieplatycauda pratti gen. n., sp. n. and Two New Species of Myxobolus (Myxosporida)*
Authors: WYATT ELLIS J.
Published: May 2007

Synopsis.

Facieplatycauda pratti gen. n., sp. n. and Myxobolus kozloffi sp. n., from the Klamath Lake sucker,Catostomus luxatus (Cope), are described. The new genus is placed in the family Myxobolidae between Henneguya and Myxobolus. The spore valves beyond the sporoplasmic space are broad and long but not attenuated as an inverted triangle as in certain species of Myxobolus with tails, or of Henneguya with sometimes bifurcated tails. An organism resembling Myxobolus insidiosus (Wyatt & Pratt) was found in the muscle of the body of Salmo clarki (Richardson). Differences in spore structure and site of infection suggest this is a subspecies of the previous form which should be designated Myxobolus insidiosus clarki. A previously unreported species of Myxobolus from Cottus aleuticus (Gilbert) is also described.
Evidence for Chromosomal Macronuclear Substructures in Tetrahymena*†
Authors: SEYFERT HANS‐MARTIN
Published: May 2007

SYNOPSIS.

Under the growth conditions employed, the G1 macronucleus of Tetrahymena pyriformis HSM contains 7.4 × 10‐12 g DNA, the G2 micronucleus 0.42 × 10‐12 g. DNA content from the Tetrahymena thermophila macronucleus did not significantly differ from that of HSM, but the micronucleus contained about twice as much DNA as the micronucleus of the HSM cells. The T. thermophila macronucleus contained on average enough DNA for ˜ 35 haploid micronuclear copies. A new spreading technic allowed separation of macronuclear substructures from cells of late G2 to early G1. Photometric determination of DNA content of 345 individual structures suggested the existence of 5 different‐sized macronuclear structures with a DNA content corresponding to 2, 4, 8, and 16 × the basic values. Comparison of the DNA content of these structures with (a) mitotic micronuclear chromosomes and (b) meiotic micronuclear chromosomes of T. thermophila cells suggests that the 5 basic values of macronuclear structures derive from structures of micronuclear chromosomes. The micronuclear chromosomes of T. pyriformis may be oligotenic. It is suggested that these results further our understanding of macronuclear organization.
Morphologie, Infraciliatur und Ökologie der limnischen Tintinnina: Tintinnidium fluviatile Stein, Tintinnidium pusillum Entz, Tintinnopsis cylindrata Daday und Codonella cratera (Leidy) (Ciliophora, Polyhymenophora)*
Authors: FOISSNER WILHELM , WILBERT NORBERT
Published: May 2007

Synopsis.

Structure, infraciliature, and ecology of 4 fresh‐water Tintinnina were investigated. The lorica of Tintinnidium fluviatile is gelatinous, fragile, and contains some agglutinated material mainly of biologic origin. Its infraciliature consists of ˜ 10 kineties. with kinetosomes arranged in pairs. Only one basal body of a pair is ciliated, except for the uppermost 1–4 pairs which have 2 slightly elongated cilia. In Tintinnidium fluviatile. Tintinnidium pusillum, and Tintinnopsis cylindrata there are 2 prominent ventral organelles. The lorica of T. pusillum is gelatinous and coated with much agglutinated material of biologic and nonbiologic origin. Its infraciliature is similar to that of T. fluviatile, but the uppermost pair of kinetosomes has elongated cilia. The firm loricae of T. cylindrata and Codonella cratera are, built mainly of sharp‐cornered structures. The infraciliature of T. cylindrata is composed of ˜ 10 kineties with kinetosomes not arranged in pairs. The infraciliature of C. cratera consists of ˜ 32 kineties, in some of which the kinetosomes are paired, e.g. ventral kinety, and in others not paired, e.g. cilia of the very prominent lateral field and of the other somatic kineties. The uppermost kinetosomes of each somatic kinety are paired and have elongated cilia. In addition, there is an unusual ventro‐lateral kinety. The oral apparatus consists of adoral membranelles and a paroral membrane. The membranelles that enter the praecral cavity are very elongate, a feature perhaps unique to Polyhymenophora. The fibrillar system consists of a prominent praeoral ring formed by fibrils extending from the adoral membranelles. A finely meshed silverline system extends over the entire cell.

A review of the ecology of the fresh‐water Tintinnina indicated that water temperature seems to be the most essential ecologic factor.

The systematic position of the Tintinnina is discussed in light of their infraciliature. It is concluded that these organisms are most closely related to Oligotrichina, and probably to Heterotrichina.
Toxoplasma gondii‐Vertebrate Cell Interactions. II. The Intracellular Reproductive Phase
Authors: DVORAK JAMES A. , HOWE CHRISTINE L.
Published: May 2007

SYNOPSIS.

The reproduction of Toxoplasma gondii RH‐strain in vertebrate cells was studied in a controlled‐environment culture system. The lag period before reproduction and the doubling time of individual parasites were determined using a least‐squares linear regression method of analysis which does not artificially constrain the data. In the majority of cases, the time intercept of the linear regression line was either zero, implying the lack of a lag phase before reproduction, or negative, implying the parasite had completed part of its reproductive cycle before entering the host cell. The mean doubling time of T. gondii is 10.9 h in bovine embryo skeletal muscle cells and 8.3 h in HeLa cells. This difference is not significant at the 5% level. The population doubling times of mouse‐derived parasites is best described by a gamma distribution.
Rhabdospora thelohani Laguessé, 1895 (Apicomplexa): New Host and Geographic Records with Taxonomic Considerations*
Authors: MAYBERRY LILLIAN F. , MARCHIONDO ALAN A. , UBELAKER JOHN E. , KAZIĆ DANILO
Published: May 2007

SYNOPSIS

New fish species and geographic records for Rhabdospora thelohani Laguessé, 1895 (rodlet cells) are presented. Additionally, the ultrastructure of R. thelohani in Alburnoides bipunctatus ohridanus Karaman, Borostomias antarcticus (Louml;nnberg), Leuciscus cephalus albus Bonaparte and Rutilus rubilio (Bonaparte) is compared with that reported by other authors and with members of Subphylum Apicomplexa. The ultrastructure of R. thelohani was similar in all the fish species examined: however, the organism was not present in all members of any single species and had intertissue density variations. Rhabdospora thelohani is pyriform. averaging in size 7 × 12 m̈, with a basal nucleus. The surface complex is composed of a layer (0.5 m̈m diameter) formed by microfilaments (9.3 nm) and an outer trilaminar membrane (9.3 nm). The cytoplasm contains structures identical to rhoptries, micronemes and subpellicular microtubules. Mitochondria. Golgi apparatus, and rough endoplasmic reticulum were not observed, although free ribosomes were present and arranged in a vesicular pattern. The observations suggest that the organism moves between cells of epithelial layers and is either released into a lumen intact or passively or actively discharges its contents into a lumen. Results from this study indicate that R. thelohani should be considered a member of Apicomplexa unless definitive evidence is presented to the contrary.
Henneguya adiposa Minchew (Myxosporida) in the Channel Catfish: Ultrastructure of the Plasmodium Wall and Sporogenesis*
Authors: CURRENT WILLIAM L.
Published: May 2007

SYNOPSIS

Wall ultrastructure and sporogenesis were studied in plasmodia of Henneguya adiposa Minchew which infects the channel catfish, Ictalurus punctatus (Rafinesque). Plasmodia were located among connective tissue bands of the adipose fin and were always separated from host fibrocytes by collagen fibers. The plasmodium wall consisted of a single unit membrane which was continuous with numerous pinocytic canals extending into the parasite's ectoplasm. The membrane was highly convoluted, producing an irregular parasite surface, and was covered by a fine granular coat of almost uniform thickness. Early sporogenic stages were located in a zone of cytoplasm rich in mitochondria, just interior to the zone of pinocytic canals. Later sporogenic stages, including mature spores, were concentrated in the center of the plasmodia. Sporogenesis began with the envelopment of one generative cell, the sporont, by a 2nd, nondividing, cell—the enveloping cell. The sporont and its progeny proceeded through a series of divisions until 10 cells were present within the enveloping cell. Once divisions were completed, the 10 cells became arranged into 2 identical spore‐producing units, each consisting of one binucleate sporoplasm and 2 capsulogenic cells, all surrounded by 2 valvogenic cells. Later stages of spore development indicated that capsulogenesis, valvogenesis and sporoplasm maturation occurred concomitantly.
Effect of Exposure Period and Algal Concentration on the Frequency of Infection of Aposymbiotic Ciliates by Symbiotic Algae from Paramecium bursaria
Authors: WEIS DALE S. , AYALA ALFRED
Published: May 2007

SYNOPSIS

The effect of exposure period and concentration of algae on the frequency of infection of aposymbiotic ciliates by algae obtained from the same clone of Paramecium bursaria syngen 2, was studied. The frequency of infection was roughly proportional to the algal concentration and to the exposure time of ciliates to algae. The relationship of algal concentration to infection frequency closely fitted the Poisson distribution curve for N = 1, suggesting that the minimum number of algae required to infect a single ciliate is 1. However, the data also strongly suggested that the average number of algae required to initiate infection of an average ciliate was ˜ 1,000. Three possible resolutions of this situation are: (a) the selection by the ciliate of a rare infective variant from a heterogeneous population: (b) the rare escape of an alga from digestion by the ciliate; and (c) the requirement for a large number of algae‐ciliate contacts to induce susceptibility in the ciliate. Splitting the exposure of ciliates to algae into 2 periods of 0.5 h, separated by 5 h in the absence of algae, produced a much higher frequency of infection than a single l‐h exposure, supporting the suggestion that the large number of algae is required to induce susceptibility in the ciliate which can then be infected by as few as a single algal cell.
Isolation, Enumeration and Identification of Amebae from a Nebraska Lake*
Authors: O'DELL WILLIAM D.
Published: May 2007

SYNOPSIS

A plaque technic was evaluated and used for the isolation and enumeration of small, free‐living amebae in lake‐bottom samples which were collected each month for one year from a Nebraska lake. Several culture media were evaluated, and a simple glucose‐salts medium was chosen. The most frequent ameba in the lake‐bottom samples was Acanthamoeba polyhaga which underwent marked increases and decreases in population densities during the collection period. This pattern was not correlated with water temperature, bacterial counts, and nitrate or phosphate levels. Other species of amebae of the genera Hartmannella, Vahlkampfia, Naegleria, Paratetramitus and Echinamoeba were isolated. Most of these were either found infrequently or remained at relatively low, constant densities throughout the year. In addition, 4 species of Acrasieae of the genera Dictyostelium and Polysphondylium were isolated from the lake‐bottom samples.
Starch Gel Electrophoresis: An Effective Method for Separation of Pathogenic and Nonpathogenic Naegleria Strains*
Authors: NERAD THOMAS A. , DAGGETT PIERRE‐MARC
Published: May 2007

SYNOPSIS. Isoenzyme electrophoresis of 7 different enzyme systems was used to compare 24 strains of Naegleria fowleri and 6 strains of N. gruberi. The 30 strains could be grouped into 4 distinct categories based upon zymogram patterns. No interstrain band variation in all enzyme systems was demonstrated in pathogenic strains of N. fowleri. Three nonpathogenic high temperature‐tolerant strains of Naegleria had similar zymograms. Four of the 5 remaining nonpathogenic Naegleria strains had no interstrain band variation. Based upon zymograms, the 22 pathogenic strains constitute a homogenous species. Similarly the high temperature‐tolerant nonpathogenic strains formed a cohesive group. The remaining nonpathogenic strains could be separated into 2 groups.
Exocellular Carbohydrase Formation by Rumen Holotrich Ciliates
Authors: WILLIAMS A. G.
Published: May 2007

SYNOPSIS Exocellular carbohydrase activity was detected, in the absence of cell lysis, in cell‐free culture supernatant fluids of rumen holotrich ciliates after incubations in buffer systems of varying tonicity, from cell suspensions that were isolated by various technics, and in which bacterial activity had been suppressed by antibiotics. The kinetic characteristics of the holotrich invertases and β–glucosidase from Dasytricha, although having interspecies variations, were the same for the intra‐ and extracellular form of the enzyme. The properties of the invertase activity present in cell‐free rumen contents resembled those of the exocellular enzymes formed by the holotrichs. Invertase activity in the in vitro culture supernatant fluid of Dasytricha ruminantium increased throughout the incubation period and was influenced by the initial pH, temperature, sucrose concentration, and inoculum size. Exocellular holotrich carbohydrase activity was increased when the incubation substrate was not readily utilized by the protozoa. Intracellular carbohydrase activity was also influenced by the carbohydrate substrate.
Morphogenèse de Régénération chez le CiliéCondylostoma magnum (Spiegel): Etude ultrastructurale
Authors: BOHATIER JACQUES
Published: May 2007

RESUME. Les événements corticaux qui se produisent au cours des stades successifs de la régénération orale chez Condylostoma magnum (Spiegel) sont étudiés cytologiquement au microscope électronique.

La zone de cicatrisation est très riche en vacuoles et petites vésicules en relation avec la membrane plasmique. La multiplication cinétosomienne débute sur le cǒté gauche des cinéties du territoire ventral gauche en “V” normalement impliqué dans la stomatogenèse, au niveau du cinétosome antérieur des paires somatiques. La prolifération se poursuit par l'apparition de jeunes cinétosomes le plus souvent orthogonaux aux anciens. Ce processus de multiplication très rapide aboutit à la formation d'un “champ anarchique,” au sein duquel on observe que: (a) les cinétosomes néoformés ne possèdent pas tous des fibres postciliaires associées, et, (b) lorsque la présence de cette catégorie de fibres tangentielles peut ětre décelée, l'orientation des cinétosomes ainsi définie est reconnue quelconque. La différentiation des organelles adoraux se fait dans la partie gauche du champ (primordium de gauche), par alignement des cinétosomes sur 2 rangées pour chaque organelle (orientées perpendiculairement à l'axe antéro‐postérieur du Cilié), dont une seule (postérieure) possède des postciliaires. La ciliogenèse intervient pour de nombreux cinétosomes dès le stade du champ “anarchique”; pour certains cinétosomes elle s'achève au début de l'agencement en organelles, et est concomitante de la poussée des némadesmes. La 3ème rangée (antérieure) des organelles, les desmoses inter‐cinétosomiennes, et les liaisons entre organelles voisins, n'apparaissent que secondairement. La différenciation de la ciliature parorale (à droite) est plus tardive. Elle se fait à l'intérieur d'un primordium, dont l'organisation est primitivement “anarchique,” et est accompagnée par une résorption progressive de la plus grande partie des cinétides néoformées. En particulier, de nombreux cinétosomes du champ droit possèdent des fibres postciliaires associées, qu'on ne retrouve pas an niveau de la “polystichomonade” régénérée. Enfin, la genèse des nouveaux cinétosomes au sein d'une cinétie somatique, au moment de son allongement est également décrite.
Hysteresis of Contraction‐Extension Cycle of Glycerinated Vorticella
Authors: OCHIAI TSUTOMU , ASAI HIROSHI , FUKUI KEIJI
Published: May 2007

SYNOPSIS. The helical coiling state of a glycerinated stalk in the family Vorticellidae had been regarded, without any evidence, as a reversible and completely equilibrated mechano‐chemical system regulated by the external free Ca2+ concentration. Our present detailed observations of many individual stalks of glycerinated Vorticella convallaria revealed that the contraction‐extension cycle of the helical stalks caused by increasing and decreasing free Ca2+ concentrations in the medium represents a kind of hysteresis. This phenomenon was observed in extensively glycerinated Vorticella in a medium of very low or physiological ionic strength, as well as in briefly glycerinated ciliates. With regard to the configurational change in various parts of a glycerinated stalk during the contraction‐extension cycle, it was found that the initial bending of the stalk caused by increasing free Ca2+ concentration begins to take place near the zooid (head) while the initial reextension of the stalk with decreasing free Ca2+ concentration begins to take place near the zooid (head) while the initial reextension of the stalk with decreasing free Ca2+ concentration takes place simultaneously throughout the entire stalk. The Ca2+ threshold for complete reextension of the part of the stalk near the rootlet was found to be much higher than that near the zooid.
Cyclical Transmission of Trypanosoma brucei rhodesiense and Trypanosoma congolense by Tsetse Flies Infected with Culture‐Form Procyclic Trypanosomes*
Authors: EVANS DAVID A.
Published: May 2007

SYNOPSIS. Culture procyclic forms of Trypanosoma brucei rhodesiense and Trypanosoma congolense were fed to Glossina morsitans morsitans through artificial membranes. A very high percentage of the flies so fed produced established midgut infections, a proportion of which went on to develop into mature metacyclic trypanosomes capable of infecting mammalian hosts. The method offers a safe, clean way of infecting tsetse flies with African trypanosomes which reduces the need for trypanosome‐infected animals in the laboratory.
Life Cycle of Isospora rivolta (Grassi, 1879) in Cats and Mice*
Authors: DUBEY J. P.
Published: May 2007

SYNOPSIS. The endogenous development of Isospora rivolta (Grassi) was studied in cats fed oocysts, and was compared with the endogenous cycle after feeding them mice infected with I. rivolta. For the mouse‐induced cycle, 14 newborn cats were killed 12 to 240 h after having been fed mesenteric lymph nodes and spleens of mice. Asexual and sexual development occurred throughout the small intestine, in epithelial cells of the villi and glands of Lieberkuhn. The number of asexual generations was not determined with certainty, but there were at least 3 structurally different meronts. Type I meronts appeared at 12–48 h postinoculation (HPI). They were 8.5(6–13) × 5.1(3–6) μm, contained 2–8 merozoites, and divide by binary division or endodyogeny. Type II meronts were multinucleate merozoite‐shaped meronts within a single parasitophorous vacuole. They were found at 48–172 HPI and measured 12.6(9–18) × 9.8(9–13) μm. Individual multinucleate merozoite‐shaped meronts were 7–13 × 3–5 μm in sections and contained 2–30 slender (5.5 × 1.0 μm) merozoites. Type III meronts occurred at 72–192 HPI and gamonts at 72–96 HPI. Mature microgamonts measured 11.3(9–15) × 8.0(6–9) μm in sections and up to 21.5 × 14 μm in smears, and contained up to 70 microgametes. Macrogamonts measured 13.3(11–18) × 9.0(5–13) μm in sections and 18 × 16 μm in smears. Oocysts were 10–15 × 9–15 μm in sections and 19.8(17–24) × 18.0(17–23) μm in fixed and stained smears. Unsporulated oocysts in feces were 22.3(18–25) × 19.7(16–23) μm and spomlated oocysts 25.4(23–29) × 23.4(20–26) μm. Sporulation was completed within 24 h at 22–26 C. For the study of the oocyst‐induced cycle in cats, 18 newborn cats were killed between 6 and 192 HPI. The endogenous development was essentially similar to the mouse‐induced cycle, but merogony and gametogony occurred 12–48 h later than in the latter cycle.

Isospora rivolta was pathogenic for newborn but not for weaned cats. Newborn cats fed 105 sporocysts or infected mice usually developed diarrhea 3–4 days after inoculation. Microscopically, desquamation of the tips of the villi and cryptitis were seen in the ilium and cecum in association with meronts and gamonts.

For the study of the development of I. rivolta in mice, mice were killed from day 1 to 23 months after having been fed 105–105 sporocysts, and their tissues were examined for the parasites microscopically, and by feeding to cats. The following conclusions were drawn. (A) Isospora rivolta most frequently invaded the mesenteric lymph nodes of mice and remained there for 23 months at least. It also invaded the spleen, liver, and skeletal muscles of mice. This species could not be passed from mouse to mouse. Sporozoites increased in size from ˜6.8 × 4.9 μm on day 1 to ˜13.4 × 6.9 μm on day 31 postinoculation. Division was not seen.

Prepatent period was 4–7 days and patent periods ranged from 2 to several weeks.
A Propos D'observations Sur L'ultrastructure Du Cilié Cyrtolophosis Mucicola Stokes, 1885
Authors: DIDIER P. , PUYTORAC P. DE , WILBERT N. , DETCHEVA R.
Published: May 2007

RESUME L'étude détaillée du cortex et des organelles buccaux de Cyrtolophosis mucicola montre que ce Cilié possède une organisation structural corticale comparable à celle de Woodruffia, Platyophrya, Kuklikophrya et des Colpoda. Tout en restant conforme au plan général d'organisation de ces derniers, il a des variations spécifiques décelées au niveau des organelles buccaux qui confirment la position de C. mucicola dans la famille des Cyrtolophosididae, incluse dans le sous‐ordre des PLATYOPHRYINA.
Sarcocystis Idahoensis Sp. N. In Deer Mice Peromyscus Maniculatus (Wagner) and Geopher Snakes Pituophis Melanoleucus (Daudin)*,†
Authors: BLEDSOED̊ BOB
Published: May 2007

SYNOPSIS Deer mice Peromyscus maniculatus (Wagner) were trapped near Hammett, Idaho, as a possible source of Besnoitia jellisoni Frenkel and species of Sarcocystis to be used for life cycle studies. Forty‐nine deer mice were necropsied; 20 (40.8%) were positive for sarcocysts structurally identical with those of Sarcocystis idahoensis sp. N. the source of S. idahoensis used for life cycle studies was a Great Basin gopher snake Pituophis melanoleucus deserticola Stejneger killed near Hammett, Idaho; 20 sporulated sporocysts measured 11.1 × 13.4 (11‐12 × 13‐14) μm. Structurally identical sporocysts were found in 7 of 14 Pacific gopher snakes P. m. catenifer (Blainville), and in 6 of 10 San Diego gopher snakes, P. m. annectens Baird & Girard. Totals of 148 deer mice and 17 gopher snakes were necropsied in the course of life cycle studies. Development of the first generation meronts took place within the hepatocytes of deer mice 2‐10 days post‐inoculation (PI) with sporulated sporocysts. Rosette‐shaped meronts (6‐8 days PI) contained tachyzoites attached by their posterior poles to a residual body. After release from the residual body, tachyzoites were initially retained in a meront wall and later released from the hot cells Within muscle cells a single tachyzoite‐shaped structure was found 11 days PI and PAS‐negative metrocyte‐containing sarcocysts (2nd generation meronts) 13‐34 days PI. PAS‐positive material was first seen in sarcocysts 34 days II at which time bradyzoite formation became apparent. At 160 days PI, 10 sarcocysts measured 0.4 × 5.8 (0.2‐0.9 × 1.8‐9.9) μ and appeared to be mature and structurally identical with those from naturally infected deer mice. After ingestion of S. idahoensis‐infected deer mice by gopher snakes, bradyzoites developed directly into microgamonts and macrogametes. These stages were first seen 5 days PI. Microgamonts were generally located above and macrogametes below the epithelial host cell nucleus. Seven to 11 days PI microgamonts were seen with mature microgametes, and oocysts which had not yet begun sporogony were found with oocyst walls. Clinical signs of illness were generally not observed in infected gopher snakes; however, one snake developed anorexia and cachexia, and became moribund after repeated ingestion of heavily infected deer mice. Acute hepatitis associated with developing meronts often was noted in deer mice given over 15,000 sporocysts each. Five to 6 days PI anorexia, weakness, ataxia, and dyspnea were observed: these clinical signs increased in severity until 6‐8 days PI, when mice became recumbent and died, or were killed while moribund. Hepatosplenomegaly, petechial hemorrhage o the serosal and cut surfaces of the liver, and icterus were common. Diffuse coagulative necrosis with cellular infiltration (primarily neutrophils) was noted on microscopic examination.