bluuebunny/crossref_metadata_2025 huggingface dataset:
A Diurnal Settling Rhythm in Platymonas subcordiformis Hazen*
Authors: GRANT W. STEWART , VADAS ROBERT L.
Published: May 2007

SYNOPSIS. In cultures of Platymonas subcordiformis Hazen, grown in appropriate light‐dark cycles, as many as 75% of the cells adhered to the surface of the glass culture vessel toward the end of the light period of each day. Cell division occurred primarily while the cells were attached. Subsequently, motile daughter cells were released into the growth medium by the rupture of the mother cell theca. The settling behavior appears to be an integral part of the life cycle being synchronized to the same extent as cell division.
Prevalence and Morphology of Eimeria gadi (Fiebiger, 1913) in the Haddock
Authors: ODENSE P. H. , LOGAN V. H.
Published: May 2007

SYNOPSIS. The coccidian parasite Eimeria gadi was found in the haddock, Melanogrammus aeglefinus, taken from the Nova Scotian fishing banks. The haddock infection rates ranged from a high of 58% on Emerald Bank to a low of 4% on Georges Bank, the average being 32%. There was no relationship between sex and degree or prevalence of infection. Although the probability of an occurrence of infection increased with size, small fish with heavy infections were observed. The degree of infection had no apparent effect on the condition factor (length/weight) of the fish. The infection rate reached a maximum in the fall of the year while the heaviest infections were observed in the spring. It is evident from the data that the infection is fatal.

The parasite mass, appearing as a creamy viscous to a yellow semisolid material in the swimbladder, consisted of various parasite stages, fibrous and cellular debris, and lipid material. Some aspects of the sporocyst stage are described.

No other gadoids from the Nova Scotian banks were found to be infected; however, a single specimen of the fourbeard rockling, Enchelyopus cimbrius, from St. John's, Newfoundland, was found to be heavily infected with E. gadi.
Cessation of Nuclear DNA Synthesis in Differentiating Naegleria*
Authors: CORFF SONDRA , YUYAMA SHUHEI
Published: May 2007

SYNOPSIS. DNA synthesis during growth and differentiation in Naegleria gruberi strain NEG populations has been studied. Autoradiography of cells labeled with [3H]thymidine revealed that grains are concentrated over the nuclei in logarithmically growing populations of cells, whereas in differentiating cells, grains are scattered over the cytoplasm; i.e. no significant nuclear labeling is detectable. It was established by MAK chromatographic analysis that [3H]thymidine is incorporated into double‐stranded DNA in Naegleria and that the actual amount of incorporation in the logarithmically growing populations of cells is 20 times greater than that in differentiating cells. These results suggest that nuclear DNA synthesis is reduced markedly soon after the initiation of differentiation, while cytoplasmic DNA synthesis continues. It was established from cell cycle analysis that the approximate intervals of G1, S, G2, and M phases were 180, 183, 90, and 28 min, respectively. Hence, the reduction in the nuclear DNA synthesis in differentiating cells is not due to the inhibition of initiation of DNA replication, but rather to the termination of the DNA replicating process. Thus DNA synthesis is curtailed in the presence of RNA and protein synthesis which are required for differentiation.
Acid Hydrolase Activity During Growth and Encystment in Acanthamoeba castellanii*
Authors: MARTIN SCOTT M. , BYERS THOMAS J.
Published: May 2007

SYNOPSIS. The activity and sedimentation of acid phosphatase (APase), acid deoxyribonuclease (DNase), and acid ribonuclease (RNase) were investigated throughout growth and encystment in Acanthamoeba castellanii. The activities/mg protein of all 3 hydrolases are high in young cultures and decrease to constant levels in postlog cells. The RNase activity/ ameba decreases 50% during growth, whereas the activity/cell of both APase and DNase remains constant. The percent sedimentation at 20,000 g of all 3 enzymes gradually increases from about 40% in midlog to a plateau of 80% in postlog cells. During encystment, the sedimentation behavior of RNase differs from that of APase and DNase. Encystment is characterized by a differential decrease in the activity/cell of the 3 hydrolases, with RNase decreasing most rapidly and APase least rapidly. APase is unique in that a transient increase of its specific activity is noted during encystment, even though its activity/cell is decreasing.
Glucolipid Synthesis in Acanthamoeba castellanii*
Authors: SKRDLANT HAROLD B. , WEISMAN ROBERT A.
Published: May 2007

SYNOPSIS. Cell‐free preparations of Acanthamoeba castellanii trophozoites transfer glucose from UDP‐[U‐14C]glucose to a chloroform‐soluble form. This radioactive material has been isolated by thin‐layer chromatography; it contains an alkali‐labile and an alkali‐stable (unsaponifiable) component. Treatment of the enzymic product with 0.1 N KOH for 15 min at 0 C or 20 C releases radioactivity into the aqueous phase as glucose. During this treatment, 30–60% of the original glycolipid remains chloroform‐soluble. It is considered to be an alkali‐stable glycolipid because no further loss of radioactivity occurs during an additional 45‐min of treatment with 0.1 N KOH. During incubation with 0.1 N HCI at 100 C glucose is released quantitatively from both the untreated glycolipid and the alkali‐stable glycolipid with a half‐time of 6 min. Glycolipid formation is inhibited by UDP and is reversible; extracts catalyze the formation of UDP‐glucose from the alkali‐stable glucolipid and UDP.

The chemical and physical properties of the alkali‐stable glycolipid are consistent with a glucosyl phosphoryl polyprenol structure. Extracts prepared from cysts catalyze the formation of glycolipids aiso, but the glucosyltransferase activity/cell decreases during the course of encystment. Radioactivity is incorporated into the fraction insoluble in chloroform‐methanol‐water (1:1:1:) during these incubations when UDP‐[U‐14C]glucose or [14C]glycolipid is the substrate.
Coccidian Parasites from Iowa Turtles: Systematics and Prevalence*
Authors: WACHA RICHARD S. , CHRISTIANSEN JAMES L.
Published: May 2007

SYNOPSIS. A survey of 22 Western Painted Turtles (WPT), Chrysemys picta belli Gray; 2 Map Turtles (MT), Graptemys geographica Le Sueur; 8 False Map Turtles (FMT), Graptemys pseudogeographica Gray; 26 Illinois Mud Turtles (IMT), Kinosternon flavescens spooneri Smith; and 5 Spiny Softshell Turtles (SST), Trionyx spiniferus Le Sueur, revealed the presence of 10 species of coccidia. The species found, the shape and average length‐width dimensions (in micrometers) of their oocysts, and the respective hosts from which they were isolated were as follows: Eimeria chrysemydis Deeds & Jahn, slightly pear‐shaped (27.6 × 17.0), from 5 WPTs; Eimeria delagei marginata Deeds & Jahn, markedly pearshaped (22.1 × 17.6), from 2 WPTs, 1 MT, and 3 FMTs; Eimeria graptemydos sp. n., broadly ellipsoid to subspherical (12.6 × 11.4), from 10 WPTs, 2 MTs, and 5 FMTs; Eimeria lutotestudinis sp. n., broadly ellipsoid to subspherical (11.9 × 10.8), from 4 IMTs; Eimeria mascoutini sp. n., broadly ellipsoid to subspherical with outer surface of oocyst wall mammillated (14.0 × 11.9), from 2 SSTs; Eimeria mitraria (Laveran & Mesnil), asymmetrically ellipsoid, bearing 1 or 2 conical projections at the polar end and 2 or 3 at the antipolar end (10.0 × 7.6), from 7 WPTs, 1 MT, 3 FMTs, and 4 IMTs; Eimeria pseudogeographica sp. n., narrowly ellipsoid to slightly ovoid (19.5 × 13.5), from 5 WPTs and 3 FMTs; Eimeria tetradacrutata sp. n., spherical to subspherical with outer surface of oocyst wall mammillated (19.5 × 19.2), from 1 WPT; an Eimeria sp. narrowly ellipsoid, bearing 2 conical projections at the polar end and 2 at the antipolar end (23.8 × 13.2), from 1 MT; and Mantonella hammondi sp. n., conical to narrowly ellipsoid, bearing 1 conical projection at the polar end and 2 or 3 at the antipolar end (14.3 × 7.1), from 1 IMT. The overall infection rate for the 63 turtles examined was 54.0%.
Scanning Electron Microscope Observations of Amoeba proteus During Phagocytosis*
Authors: JEON K. W. , JEON M. S.
Published: May 2007

SYNOPSIS. Phagocytosing Amoeba proteus at different stages of forming foodcups have been observed by scanning electron microscopy. A nonphagocytosing ameba is characterized by dorsal and lateral ridges running longitudinally over the posterior half of the cell and its attachment to the substrate over small areas. When stimulated by prey organisms, the ameba loses polarity and ridges, and adheres to the substrate more firmly over a wider area of contact. Then it forms broad pseudopods to surround its prey and this results in the formation of foodcups. The surface of all amebae is covered with small projections, and membranous blebs are often seen on the surface of phagocytosing organisms.
Comparative Kinetics of Arginine and Lysine Transport by Epimastigotes and Trypomastigotes from Two Strains of Trypanosoma cruzi*
Authors: GOLDBERG S. S. , PEREIRA A. A. SILVA , CHIARI E. , MARES‐GUIA M. , GAZZINELLI G.
Published: May 2007

SYNOPSIS. Three‐day‐old cultures of Y and MR strains of Trypanosoma cruzi had a higher rate of lysine and arginine uptake than 10‐day cultures. Amino acid uptake by cells of the MR strain was consistently higher than that of the Y strain.

Flagellates separated on DEAE‐cellulose columns have normal structure, motility, and infectivity; they have higher rates of lysine and arginine uptake than the original 3‐ and 10‐day cultures. In addition, passage through DEAE‐cellulose columns modified the kinetic behavior of amino acid transport systems in the flagellate membranes.

Methionine inhibited uncompetitively uptake of lysine and arginine by MR and Y strains. Lysine inhibited arginine uptake by both strains by an uncompetitive mechanism. Lysine, however, inhibited the uptake of arginine by 10‐day culture cells of the Y strain by a mixed‐type of inhibition. Arginine also inhibited the lysine uptake of both strains by an uncompetitive mechanism. In all experiments, beyond a certain level, a further increase in inhibitor concentration resulted in a decreased inhibition, which eventually disappeared altogether. Inhibition of amino‐acid uptake by any of the substances tested was not observed after passage of flagellates through a DEAE‐cellulose column.

A model for amino acid transport was formulated which includes a recognition site amenable to modulation by effectors.
DNA Throughout the Single Mitochondrion of a Kinetoplastid Flagellate: Observations on the Ultrastructure of Cryptobia vaginalis (Hesse, 1910)
Authors: VICKERMAN KEITH
Published: May 2007

SYNOPSIS. Cryptobia vaginalis (Hesse 1910) occurs as long thin and short broad forms in the vagina of the gnathobdelliform leeches Haemopis sanguisuga (Linnaeus) and Hirudo medicinalis Linnaeus. Cytochemical staining for DNA and transmission electron microscopy of sectioned material indicate that in the thin forms the kinetoplast DNA (kDNA) is dispersed irregularly through the mitochondrial network (pankinetoplastic condition) rather than concentrated in the adbasal region of the mitochondrion (eukinetoplastic condition) as in trypanosomatids and most other kinetoplastid flagellates. Light‐microscopic studies on the rare broad forms, however, suggest that these have conventional adbasal location of the kinetoplast. Binary fission appears to occur in the thin forms, suggesting that the dispersed kinetoplast is either highly polyenergid or lacks a genetic function. In other features of its microanatomy, C. vaginalis is a conventional kinetoplastid. The flagellate has an incomplete corset of pellicular microtubules which may have a role in the cortical contractility characteristic of the genus Cryptobia. Feeding is by pinocytosis of vaginal colloids through a microtubule‐lined cytopharynx, possibly after binding to a prominent filament‐coated preoral ridge. A pulsatile (contractile) vacuole is present and appears to be responsible for defecation as well as osmoregulation. Some individuals have elongate bacterial epibionts attached to the body in parallel with the cortical microtubules. All individuals have 2–8 spheroplast‐like endobiotic bacteria in the prenuclear cytoplasm.
Comparative Study of Six Strains of Naegleria with Special Reference to Nonpathogenic Variants of Naegleria fowleri*
Authors: JONCKHEERE J. DE , VOORDE H. VAN DE
Published: May 2007

SYNOPSIS. Naegleria fowleri strains HB‐1 and KUL, pathogenic for humans, Naegleria gruberi strain 1518/1e, and 3 strains (Vm1, LvH1, and LvH2) of Naegleria isolated from a body of water polluted with thermal effluents were compared in an attempt at specific identifications of the latter strains. The 3 environmental isolates were morphologically almost identical with N. fowleri and had almost the same temperature tolerance, although at 37 and 42 C the growth rates of LvH1 and LvH2 were higher than those of the human pathogen, N. fowleri, and of isolate Vm1, which was pathogenic for mice. Serologic examinations by indirect fluorescent antibody method revealed a very close relationship of the new isolates with the human pathogens. While Vm1 was indistinguishable from N. fowleri, LvH1 and LvH2 were not, when cross‐absorbed antisera were used. Of all the strains examined, only the 2 LvH isolates were not inhibited by amphotericin B, while only N. gruberi was not inhibited by fumagillin. The cytopathic effect in Vero cell cultures suggested that the LvH strains could have a certain degree of virulence, although this was not confirmed by intranasal and intracerebral inoculations of mice. The cytopathic effects of the human pathogens and of the isolate pathogenic for mice were related to their virulence for mice. It is concluded that there exists an intermediate form between N. gruberi and N. fowleri, with a strong relationship to the latter species. We refer to such strains as nonpathogenic variants of N. fowleri. Further research is needed to reveal their place in the taxonomy.
Piroplasms from Taiwanese Rodents*
Authors: PEENEN P. F. D. VAN , CHANG S. J. , BANKNIEDER A. R. , SANTANA F. J.
Published: May 2007

SYNOPSIS. Piroplasms from naturally infected bandicoot rats, Bandicota indica (Hodgson), and spiny rats, Rattus coxinga (Swinhoe), from Taiwan caused parasitemias in a wide range of laboratory animals after syringe passage in laboratory rats. Bandicoot and spiny rats could be infected with heterologous piroplasms, but neither species was susceptible to infection with the Gray strain of Babesia microti (França). Nevertheless, the Taiwan piroplasms are probably a geographic strain of B. microti.
The Plasmodium lophurae (Avian Malaria) Ribosome*
Authors: SHERMAN IRWIN W. , JONES LYNN A.
Published: May 2007

SYNOPSIS. Ribosomes were isolated from Plasmodium lophurae by Triton X‐100 lysis and ultracentrifugation. Plasmodium lophurae ribosomal subparticles, produced by treatment of ribosomes with puromycin, were separated by sucrose gradient centrifugation. The nucleotide base composition of P. lophurae ribosomal RNA (rRNA) from intact ribosomes and subparticles was low in guanine‐cytosine content (∼ 37% G + C) whereas the rRNA of the host cell (duck reticulocyte) was considerably higher (64% G + C). The rRNA of the malaria parasite was typically protozoan, with sedimentation values of 25S and 17S. In vitro, free parasites and malaria‐infected red cells incorporated radioactive adenosine into both the large and the small plasmodial subparticles; label was also recovered in the 25S and 17S RNAs. These results suggest that host ribosomes do not contribute to ribosome biogenesis in this malaria, rather parasite rRNA is the transcription product of plasmodial cistrons.
Growth of Crithidia at High Temperature: Crithidia hutneri sp. n. and Crithidia luciliae thermophila s. sp. n.*
Authors: ROITMAN ISAAC , MUNDIM MARIA HERMELINDA , AZEVEDO HELIO PEIXOTO DE , KITAJIMA ELLIOT W.
Published: May 2007

SYNOPSIS. Crithidia hutneri sp. n. and Crithidia luciliae thermophila s. sp. n. are described. Both flagellates can be grown in a defined medium over a temperature range of 15–37°C. The requirements for amino acids, vitamins, purine and hemin, and pH range were similar to those established for Crithidia fasciculata, although threonine was required as a growth factor for C. luciliae thermophila at high temperatures. Adenosine could be used by the 2 Crithidia as a purine source at 28 but not at 37 C.
Steady‐State Oxvgen Kinetics of Terminal Oxidases in Trypanosoma mega*
Authors: HILL GEORGE C. , DEGN HANS
Published: May 2007

SYNOPSIS. Steady‐state oxygen kinetics of Trypanosoma mega reveal the presence of 3 oxidases. These include an oxidase which is sensitive to salicylhydroxamic acid (SHAM) but insensitive to sodium azide. This oxidase could be the L‐α glycerophosphate oxidase present in bloodstream trypanosomes. In addition, an oxidase is present which is azide‐sensitive but SHAM‐insensitive. This oxidase is inhibited by CO and is probably cytochrome aa3. A 3rd oxidase is insensitive to both azide and SHAM but is inhibited by CO and is possibly cytochrome o. Reciprocal plots of T. mega reveal the presence of 2 oxidases that are inhibited by CO. These results are discussed in the light of previous evidence suggesting the presence of several oxidases and a branched electron transport system in T. mega.
Studies on the Tintinnida of Enewetak Atoll*
Authors: GOLD KENNETH , MORALES ELEANOR A.
Published: May 2007

SYNOPSIS. Twenty‐six species of Tintinnida were identified in the plankton at Enewetak Atoll. The majority of species in this habitat had hyaline loricae. The agglutinated forms had a high degree of specificity for the types of calcium‐containing particles that they incorporated into the loricae. Scanning electron micrographs of loricae are presented for 10 species.
Carbohydrate Composition of Variant‐Specific Surface Antigen Glycoproteins from Trypanosoma brucei
Authors: JOHNSON JAMES G. , CROSS G. A. M.
Published: May 2007

SYNOPSIS. The carbohydrate of variant‐specific surface antigen glycoproteins from bloodstream forms of 13 cloned variants of Trypanosoma brucei was analyzed by gas‐liquid chromatography. The glycoproteins contained from 6 to 17% carbohydrate by weight, and all contained the same 4 sugars: mannose, galactose, glucose, and glucosamine (probably as N‐acetyl‐glucosamine). The glycoprotein from variant 048, strain 427 contained (±20%) 11 mannose, 4 galactose, 4 glucose, and 5 glucosamine residues/mole of glycoprotein (molecular weight 65,000). Glucose was an integral component of the glycoproteins, not dissociable by sodium dodecyl sulphate, 8 M urea, or 1 M acetic acid. Some of the glucose was dissociated by trichloroacetic acid. Most of the glycoproteins formed precipitin bands with concanavalin A in Ouchterlony double diffusion, but none formed such bands with wheat germ agglutinin or Ricinus communis lectin (molecular weight 120,000).
Proteolytic Activities in Cell Extracts of Trypanosoma cruzi*
Authors: ITOW SHIDUCA , CAMARGO E. PLESSMANN
Published: May 2007

SYNOPSIS. Cell extracts of culture forms of Trypanosoma cruzi are capable of hydrolysing substances belonging to 4 different groups of protease substrates: (a) substrates for trypsin‐like enzymes: benzoyl‐arginine‐p‐nitroanilide and benzoylarginine‐naphtylamide: (b) substrates for aminopeptidases: leucyl. lysyl and glutamyl‐β‐naphtylamide; (c) a substrate for chymotrypsin‐like enzymes: carbobenzoxy‐L‐tyrosine‐p‐nitrophenylester, and (d) a nonspecific substrate for a broad range of proteases: azocasein. Some physico‐chemical characteristics of each enzymic reaction were studied. They were found to be distinct enough to allow attributing each hydrolytic activity to a separate enzyme.
Eimeria zapi sp. n. from the Meadow Jumping Mouse, Zapus hudsonius Zimmerman in Southwestern Michigan
Authors: GERARD GEOFFREY , CHOBOTAR BILL , ERNST JOHN V.
Published: May 2007

SYNOPSIS Four of 5 meadow jumping mice (Zapus hudsonius) captured had in their feces a previously undescribed species of Eimeria which is named Eimeria zapi sp. n. The sporulated oocysts measured 21.7 (19.5–24.0) × 20.3 (17.5–23.0) μm. The single‐layered oocyst wall was 1.5 μm thick, rough, pitted and appeared clear‐to‐amber. Usually 2 polar granules could be seen. An oocyst residuum was not observed. Each sporocyst averaged 16.0 (12.5–18.0) × 9.7 (7.5–11.5) μm. A substiedal body was present. The sporocyst residuum consisted of a membrane‐enclosed packet of 15 to 20 granules. This is the first species of Eimeria to be described from the genus Zapus.
Colpoda spiralis sp. n., a Colpodid Ciliate Found Inhabiting Treeholes (Colpodida, Ciliophora)*
Authors: NOVOTNY R. T. , LYNN D. H. , EVANS F. R.
Published: May 2007

SYNOPSIS A new species of the family Colpodidae, genus Colpoda O. F. Müller, Colpoda spiralis sp. n. is described. This organism has been found only in treehole fluid. Its species status is based on the possession of a unique and prominent preoral protuberance, multimicronuclearity, and the preference for a treehole habitat. Its range is known to include the tri‐state area of Arizona, New Mexico and Utah, and the mixed‐deciduous forests of Maryland. This species prefers treehole fluids with a pH > 7 and is naturally limited to tree species which possess these alkaline treeholes. It encysts as a treehole dries and excysts when the treehole is again filled by fluids from the tree, or rainwater.
Adaptation of Leishmania to In Vitro Cultivation at 37 C*
Authors: GILLIG III CLARENCE J.
Published: May 2007

SYNOPSIS Promastigotes of Leishmania donovani 3S grown in Tobie's modified medium (Tm) at 25 C multiplied at 37 C after short periods of growth at 32 and 35 C. Only inocula from logarithmic phase cultures grew when placed at 32 C. Amastigotes placed at 32, 35, or 37 C became promastigotes but did not multiply upon transfer. The shortest period required for adaptation of 3S promastigotes to 37 C was 44 days (∽66 generations requiring 18 serial transfers). Addition of chick embryo extract to the medium was unnecessary for growth at elevated temperatures. Promastigotes of the Khartoum strain could not be acclimated to temperatures above 35 C.

The long‐lasting nature of the adaptation was indicated by (a) ability of 37 C‐acclimated promastigotes to grow at this temperature after 14 serial transfers (∽100 generations) at 25 C, and (b) immediate growth of promastigotes at 37 C in cultures inoculated with homogenized hamster spleen previously infected with 37 C acclimated cells. The ability of the temperature‐adapted promastigotes to grow at 37 C was lost after 30 serial transfers (224 generations) at 25 C. Since sexual reproduction has not been demonstrated in Leishmania, it was impossible to ascertain whether acclimation was a consequence of mutation or represented a dauermodification.
Surface Charge of Trypanosoma cruzi. Binding of Cationized Ferritin and Measurement of Cellular Electrophoretic Mobility*
Authors: SOUZA WANDERLEY DE , ARGUELLO CARLOS , MARTINEZ‐PALOMO ADOLFO , TRISSL DOROTHEA , GONZÁLES‐ROBLES ARTURO , CHIARI EGLER
Published: May 2007

SYNOPSIS The surface charge of epimastigote and trypomastigote forms of Trypanosoma cruzi was evaluated by means of binding of cationized ferritin to the cell surface as visualized by electron microscopy, and by direct measurements of the cellular microelectrophoretic mobility (EPM). Epimastigote forms had a mean EPM of ‐0.52 μm.s‐1.V‐1.cm and were lightly labeled with cationized ferritin. In contrast, bloodstream trypomastigotes had a much higher EPM (‐1.14), and the surface was heavily labeled with cationized ferritin. When trypomastigotes from stationary phase cultures were isolated on DEAE cellulose columns, the mean EPM was found to be significantly lower (‐0.63), and labeling with cationized ferritin decreased. With a mixed population containing epimastigote, trypomastigote, and intermediate forms, EPM values ranging between ‐0.70 to ‐1.14 were found. From these observations we conclude that there is a definite increase in negative surface charge during development from epi‐ to trypomastigote forms of T. cruzi.
Toxoplasma gondii‐Vertebrate Cell Interactions. I. The Influence of Bicarbonate Ion, CO2, pH and Host Cell Culture Age on the Invasion of Vertebrate CellsIn Vitro
Authors: DVORAK JAMES A. , HOWE CHRISTINE L.
Published: May 2007

SYNOPSISA controlled‐environment culture system was used to show that both physical and biologic parameters can influence the penetration of vertebrate cells byToxoplasma gondii.The optimum bicarbonate ion concentration for the penetration of bovine embryo skeletal muscle (BESM) cells is 36.25 mM. Higher or lower bicarbonate ion concentrations are increasingly inhibitory to penetration. As CO2increases in the range from 0.5–3.7 mM, penetration is progressively inhibited. No relationship was found between penetration and pH in the pH range of 6.949–7.765. The culture age of the BESM cells directly influenced the ability of the parasites to penetrate the cells. Older BESM cells were more refractory to penetration than younger cells.
Monoamine Oxidase and Catechol‐O‐Methyl Transferase Activity in Tetrahymena*
Authors: FELDMAN JEROME M. , ROCHE JOAN M. , BLUM J. J.
Published: May 2007

SYNOPSIS Tetrahymena pyriformis strain HSM was found to have monoamine oxidase (MAO) and a catechol‐O‐methyl transferase‐like (COMT) activity. As in mammalian tissues, the MAO activity is predominantly localized in the mitochondrial pellet and COMT in the cytosol. The COMT‐like activity was present in amounts comparable to several mouse tissues and was inhibited by tropolone. MAO activity was much lower than in any of the mouse tissues tested, and its activity varied greatly from preparation to preparation. The substrate preference of Tetrahymena MAO was tryptamine > serotonin > dopamine, and activity increased with increasing pH from pH 6.5 to pH 7.8, as does that of mouse liver MAO. The Km of Tetrahymena MAO for tryptamine was 4 μM, an order of magnitude lower than that of mouse liver MAO. Sensitivity to inhibition by MAO inhibitors was variable. In some preparations, no inhibition was observed. In others clear inhibition was obtained, harmine and clorgyline being among the most potent inhibitors.
Organization and Control of Microtubule Pattern in Centrohelidan Heliozoa*†
Authors: BARDELE CHRISTIAN F.
Published: May 2007

SYNOPSIS. Comparative studies of axopodial microtubule pattern in 10 different centrohelidan Heliozoa belonging to the genera Acanthocystis, Raphidiophrys and Heterophrys suggest that 2 basic principles govern pattern formation in centrohelidan Heliozoa. While the larger “open” arrays with unspecified number of microtubules, e.g. in A. aculeata and R. ambigua, may result from self‐linkage of additional microtubules around centroplast‐nucleated “starter microtubules,” the smaller “closed” arrays with specified microtubule number, e.g. in A. pectinata and H. marina, favor a template‐driven linkage mechanism. The centroplast is a highly complex microtubule organizing center involved in the control of orientation, number, and diameter of the axonemes. Its shell may serve as a surface upon which the microtubule nucleating sites assemble, but how the precise positioning of these sites occurs is still open to debate. Some of the unsolved problems of microtubule pattern formation may be explained by the “linker nucleation hypothesis” which is an extension of the “gradion hypothesis” by Roth et al. It is shown how both the formation of closed arrays and the balanced lateral growth of open arrays may result from linker‐induced microtubule nucleation.
Some Ultrastructural and Functional Aspects of the Golgi Apparatus of Thelohania sp. (Microsporida) in the Shrimp Pandalus jordani Rathbun
Authors: VERNICK S. H. , SPRAGUE V. , KRAUSE D.
Published: May 2007

SYNOPSIS. Electron microscope observations on Thelohania sp. in the shrimp Pandalus jordani support the view that the Golgi complex in Microsporida is a “classical” one, composed of vesicular, vacuolar, and cisternal components. During development of the sporoblast, a portion of the Golgi complex is seen as an electron‐dense reticulum enmeshing the core of the polar filament. Associated with the reticulum are electron‐dense bodies. The reticulum and “dense bodies,” reported in several previous publications, have not been well understood and have been given a variety of names. The evidence favors the view that these structures have secretory activity in which the reticulum concentrates or synthesizes material, some of which takes the form of membrane‐bounded granules. It is suggested that the most appropriate name for the reticulum is “reticulum golgien,” and that the correct name for the “dense bodies” is the standard cytologic term, “secretion granules.” The secretion granules apparently remain in the posterior part of the spore, and may be stored there for some as yet undetermined use.
Caractéristiques Ultrastructurales du Cortex et des Membranelles du CiliéEspejoia mucicola (Oligohymenophora, Hymenostomata, Tetrahymenina)
Authors: DIDIER PIERRE , FRYD‐VERSAVEL GHISLAINE , IFTODE FRANCINE , WILBERT NORBERT
Published: May 2007

RESUME. L' étude détaillée du cortex et des organelles buccaux adoraux d' Espejoia montre que ce Cilié possède une organisation ultrastructurale comparable à celle des Tétrahyméniens. Tout en restant conforme au plan général d'organisation de ces derniers, des variations spécifiques décelées tant au niveau du cortex d'une part, que des membranelles, d'autre part, font ressortir des affinités trés marquées pour le genre Glaucoma et autres Ciliés voisins. En conséquence, en nous appuyant en outre sur les données récentes de la morphogenèse, nous confirmons la position d' E. mucicola parmi les Tetrahymenina, dans la famille des Glaucomidae.
Anaerobiosis and Symbiosis with Bacteria in Free‐living Ciliates
Authors: FENCHEL TOM , PERRY TED , THANE ANNE
Published: May 2007

SYNOPSIS. Marine, sediment‐dwelling ciliates were examined for cytochrome oxidase activity by a cytochemical method and for fine structural details. Species of Plagiopylidae (Trichostomatida), i.e. Plagiopyla frontata, Sonderia vorax and Sonderia sp., and of Heterotrichida, i.e., Parablepharisma pellitum, Parablepharisma sp., Metopus contortus, Metopus vestitus and Caenomorpha capucina; previously considered to be obligate anaerobes because of their sulfide‐containing habitat, do not have cytochrome oxidase activity or mitochondria with cristae or tubuli. The evolutionary origin and significance of anaerobic ciliates is discussed. Most of the anaerobic ciliates harbor a flora of ecto‐ and endosymbiotic bacteria as demonstrated by transmission and scanning electron micrographs. It is speculated that the bacteria may utilize the metabolic end products of the protozoa for growth and energy yielding processes. These associations are also compared with other, previously described cases of symbiosis involving prokaryotes and protozoa.
The Breeding System of Polysphondylium pallidum, a Cellular Slime Mold*
Authors: EISENBERG ROBERT M. , FRANCIS DAVID
Published: May 2007

SYNOPSIS. A mating type analysis was performed on 231 isolates of the cellular slime mold, Polysphondylium pallidum found in 61 samples collected in eastern North America between northern Florida and southern Canada. Seventy‐eight percent of the isolates belonged to one of 2 mating types; 18% were incapable of mating with any partner; 3% were homothallic; and 1%, consisting of 2 isolates from a Florida sample, belonged to a separate breeding group. It is suggested that the majority of isolates represent a species capable of local genetic adaptation to a niche, the parameters of which undergo considerable variation over space and time.
Effect of Age and Sex on the Acquisition of Immunity to Toxoplasmosis in Cats*
Authors: DUBEY J. P. , HOOVER E. A. , WALLS K. W.
Published: May 2007

SYNOPSIS. The effects of age and sex of the cat on oocyst shedding, multiplication of Toxoplasma gondii in tissues of cats, and acquisition of immunity were investigated after oral inoculation of cats with Toxoplasma cysts. Twenty‐five cats varying in age from 1 week to 39 months were killed 7‐97 days after inoculation with T. gondii. Homogenates of brain, heart, mesenteric lymph nodes, retina, and blood from these cats were inoculated into mice to test for Toxoplasma infectivity. Toxoplasma was isolated more frequently and in higher titers in mice receiving inocula from cats of the youngest age group (1 week old). Toxoplasma gondii was isolated from tissues of only 2 of 21 cats older than 2 months (at the time of inoculation), although all of the animals shed oocysts within 1 week after ingesting the parasites.

The number of oocysts shed varied among littermates of the same sex and between sexes. Generally, cats younger than 12 months shed more oocysts than older cats. The number of oocysts shed by older cats varied considerably; males generally shed more oocysts than the females. However, the numbers of cats examined were too small for statistical comparison. Nevertheless, the observations suggest that cats older than 12 months should not be used in experiments where numbers of oocysts shed is critical.
Taxonomy Acanthamoeba royreba sp. n. from a Human Tumor Cell Culture*
Authors: WILLAERT E. , STEVENS A. R. , TYNDALL R. L.
Published: May 2007

SYNOPSIS. A new species of Acanthamoeba was isolated from a culture of an established line of human choriocarcinoma cells. The identification of this strain, originally called the Oak Ridge strain, and the establishment of a new species for it were based on morphologic, serologic, and immunochemical studies. In general, the structure of the trophozoite did not differ significantly from that of other species of Acanthamoeba, except that a body which more closely resembled a centriole than material described previously as centriolar satellites was observed in trophozoites examined with the electron microscope. The dimensions of the trophozoite were the smallest among the species of Acanthamoeba. The cyst was typical of the genus, but differed from those of other species by its smaller size and the presence of numerous ostioles. Studies of the Oak Ridge strain by immunofluorescence using antisera developed against the isolate and Acanthamoeba culbertsoni, A. castellanii, A. polyphaga, A. rhysodes, A. astronyxis, and A. palestinensis revealed the antigenic uniqueness of the Oak Ridge strain. It was demonstrated by immunoelectrophoretic analyses of the soluble proteins of the Oak Ridge strain that it shared ∼ 1/2 of its antigenic structure with A. castellanii and A. culbertsoni. The antigenic differences of the isolate from other species of Acanthamoeba were deduced from comparison of the antigenic constitution of these species and the Oak Ridge strain with A. culbertsoni and A. castellanii. Although the strain was initially recognized by its cytopathogenicity for cultures, it did not produce acute infections in mice after intranasal inoculation of 1 × 104 amebae/mouse. The foregoing results constituted the basis for the establishment of the Oak Ridge strain as a new species, A. royreba sp. n., in the genus Acanthamoeba.
Sporozoites of Rodent and Simian Malaria, Purified by Anion Exchangers, Retain their Immunogenicity and Infectivity
Authors: MOSER GINA , BROHN FREDRICK H. , DANFORTH HARRY D. , NUSSENZWEIG RUTH S.
Published: May 2007

SYNOPSIS. Sporozoites of rodent malaria, Plasmodium berghei, and simian malaria, Plasmodium knowlesi and Plasmodium cynomolgi, were partially separated from mosquito debris and microbial contaminants by passage of Anopheles material through a DEAE‐cellulcse column. In addition to eliminating most of the contaminants (80–90%), this simple technic has made it possible to recover rapidly large numbers of viable sporozoites (55–75% yield), which have retained their infectivity, immunogenicity, and capacity to react with known antisera. Mice injected with varying doses of column‐purified sporozoites (CS) of P. berghei produced infections which paralleled those seen in the controls. Total protection against challenge with a potentially lethal dose of viable sporozoites was acquired by mice inoculated twice with irradiated CS of P. berghei. CS of P. berghei and P. cynomolgi gave positive circumsporozoite precipitation (CSP) reactions, upon inoculation with the respective immune sera. The preservation of the surface antigens of CS was documented by immunofluorescence.

It was shown that differences in elution behavior exist among sporozoites of certain species of Plasmodium as well as among sporozoites of the same species derived from different organs of the mosquito. These results may be attributed to differences in the surface charge of the sporozoites or conditions in sample media.

Purified sporozoites obtained by the method described in this report provide an adequate source of parasites for a variety of in vitro studies.
Method for the Simultaneous Establishment of Many Axenic Cultures of Paramecium*†
Authors: ALLEN SALLY LYMAN , NERAD THOMAS A.
Published: May 2007

SYNOPSIS. A method is described for the simultaneous treatment of 42 (or more) stocks of Paramecium, and their adaptation to growth in axenic culture. Samples of dense cultures of these ciliates growing with Enterobacter aerogenes are rendered bacteria‐free by migration through 2 sets of tubes containing Adaptation Medium (Peters' salts solution, stigmasterol, vitamins, and autoclaved E. aerogenes). The 2nd set of tubes contains Adaptation Medium plus antibiotics. Bacteria‐free samples containing ∼ 100 animals are then transferred to test tubes containing Adaptation Medium without antibiotics. This medium also serves as a growth medium. It supports indefinite growth of all Paramecium stocks tested. After adaptation to this medium, the ciliates can be grown in the axenic medium developed by Soldo, Godoy & van Wagtendonk. On a single trial at least half of the stocks can be expected to produce axenic cultures within 5 to 10 days by these procedures. The method has been applied successfully to several of the species of the Paramecium aurelia complex, to all syngens of Paramecium multimicronucleatum, to several stocks of Paramecium jenningsi, and to 1 stock each of Paramecium caudatum and Paramecium calkinsi. A modification of the method also works for Didinium nasutum.
The Ribonucleic Acids of Crithidia fasciculata*
Authors: MORALES NYDIA M. , ROBERTS JOHN F.
Published: May 2007

SYNOPSIS. Crithidia fasciculata ribosomes were found to be 80S and to dissociate into 58 and 41S subunits; on 5 to 50% sucrose gradients, rRNA was separated into 25, 18, and 5S components. The molecular sizes of the heavier rRNA species, estimated by polyacrylamide gel electrophoresis were 1.24 and 0.84 M (×106 daltons). The 25S RNA has a tendency to interact with the 18S RNA to give a complex that is difficult to separate by sucrose gradient centrifugation. The 25S RNA is also unstable and dissociates into 0.73 and 0.57 M components. The 18S RNA has molecular size (0.84 M) higher than the 0.7 M reported for most eukaryotes, but similar to that of Euglena and Amoeba. Ribosomal RNA hybridized 0.29% of the nuclear DNA. Mitochondrial RNA, extracted by a rapid procedure was resolved into 16 and 5S components in sucrose gradients.
The Life Cycle of Eimeria dispersa Tyzzer, 1929 in Turkeys
Authors: DORAN DAVID J.
Published: May 2007

SYNOPSIS. The life cycle of a turkey strain of Eimeria dispersa Tyzzer was studied in Beltsville Small White turkeys. There were 4 asexual generations. Mature schizonts of the first generation were present 30 h postinoculation (PI); those of the 2nd, 3rd, and 4th generations were present 48, 72, and 96 h PI, respectively. Average size of schizonts and number and size of merozoites for each generation were as follows: first, 14.3 × 13.0 μm with 19.2 merozoites, each 4.5 × 1.2 μm; second, 8.0 × 7.2 μm with 13.5 merozoites, each 4.5 × 1.1 μm; third, 8.9 × 8.9 μm with 15.1 merozoites, each 5.6 × 2.1 μm; fourth, 11.6 × 10.5 μm with 6.7 merozoites, each 8.2 × 2.0 μm. Sporozoites and developmental stages of the first generation were in close association with an epithelial cell nucleus and located between the brush border and the “row” of epithelial cell nuclei; developmental stages of the other 3 generations were not associated with a nucleus and were located just under the brush border. Early macrogametes and microgametocytes were present 96 h PI. Development was confined to the epithelial cells of the villus and extended from the tip of the villus to ∼ 1/2 the distance down the sides in all areas of the intestine except the cecum. The prepatent period was between 114 and 120 h. Percentage of sporulation was 15, 57, and 90, at 24, 36, and 48 h, respectively. Sporulated oocysts averaged 24.5 × 20.2 μm.
Ultrastructural Observations on Renal Schizogony of Leucocytozoon dubreuili in the American Robin
Authors: WONG STEVE T. C. , DESSER SHERWIN S.
Published: May 2007

SYNOPSIS. The schizogonic development of Leucocytozoon dubreuili in the kidney proximal tubule cells of the American robin, Turdus migratorius, was studied by electron microscopy. Renal schizogony is initiated by the entry of certain hepatic merozoites into cells of the proximal tubules. Development of the schizont consists of a coordinated sequence of events including extensive mitotic nuclear division, multiplication of mitochondria, increase in endoplasmic reticulum and ribosomes, differentiation of membranes, microtubules, micronemes and rhoptries, and cytoplasmic segmentation (cytomere formation). Merozoites form by budding around numerous centers in the schizont and, when mature, are bounded by a single plasma membrane subtended by microtubules. Each merozoite contains a large nucleus, a mitochondrion, and a well developed apical complex consisting of 3 polar rings, paired rhoptries, and numerous micronemes.

An atypical nuclear division observed in some maturing schizonts was characterized by the multiple fission of a nucleus within a persistent outer nuclear membrane and the absence of mitotic spindle apparatus. Alterations in infected renal cells consisted of disorganization and loss of cytoplasmic organelles and the accumulation of lipofuscin‐like inclusions.
Morphometric Variation in the Hypotrich Ciliate Genus Euplotes*†
Authors: GATES MICHAEL A.
Published: May 2007

SYNOPSIS. A quantitative method for the analysis of cirral patterns in the genus Euplotes is developed and contrasted with alternative approaches. Inherent variations in cirral pattern, as they are reflected in frequency distributions of intercirral distances, are ascertained through subclonal analyses of Euplotes harpa samples grown under different conditions. This assessment of the extent of variation within a form having 10 frontoventral cirri provides a basis for a comparative study of other Euplotes of cirrotype 10. These results suggest that all marine cirrotype 10 forms with a single dargyrome have the same configuration of frontoventral and transverse cirri. Similarly, most marine double dargyrome forms of cirrotype 10 have this same cirral pattern, and thus constitute variations upon the same morphometric theme.
Light and Electron Microscopic Observations of Gametogenesis in Hastigerina pelagica (Foraminifera)*
Authors: SPINDLER M. , ANDERSON O. R. , HEMLEBEN C. , BÉ A. W. H.
Published: May 2007

SYNOPSIS. During gametogenesis mother individuals of Hastigerina pelagica (d'Orbigny) undergo significant morphological changes. Thirty h before gamete release, the cytoplasm changes from pale orange to bright red, possibly due to transport of stored lipids from the inner region to more peripheral parts of the cytoplasm. During the next 10 to 15 h the bubble capsule which surounds the calcareous shell is discarded. After all bubbles have disappeared, the individual sheds its spines by resorbing the spine bases close to the shell surface.

A single mother nucleus divides into some hundreds of thousands of gamete nuclei within a span of ∼ 20 h. A bulge of cytoplasm is extruded from the aperture and increases in size during the next 5 to 10 h. This bulge consists of cytoplasmic strands in which gametes and spherical bodies are embedded. The gametes and spherical bodies mature and are released during the afternoon and early evening. The gametes have 2 unequal acronematic flagella. A previously undescribed structure in foraminiferal reproduction is the spherical body which consists of a large vacuole surrounded by a thin cytoplasmic layer in which several nuclei, various typical cell organelles and multiple flagella are present. The spherical bodies are believed to play a role as receptacles of waste material, possibly including residual digestive enzymes, thereby protecting the gametes from lysis during the reproductive process. Fusion of gametes and further development into the next generation have not been observed.
Some Factors Influencing the in vitro Infectivity and Replication of Encephalitozoon cuniculi*
Authors: SHADDUCK JOHN A. , POLLEY MARY B.
Published: May 2007

SYNOPSIS. Rabbit Encephalitozoon cuniculi were propagated in vitro using rabbit choroid plexus (RCP) cells. The organisms reached maximum titer and numbers by 15 days. The source and in vitro passage level of RCP cells moderately influenced the sensitivity of the cells to infection. Cells less than 1 week old were significantly less sensitive than older cells. A moderate increase in infectivity for RCP cells was demonstrated with increasing organism passage level in vitro. Rabbit E. cuniculi were not affected by penicillin‐streptomycin or gentamicin in the culture medium. The organism survived more than 9 days in buffer at 37 C and least 24 days at 4 and 20 C. Storage at ‐70 C or in liquid nitrogen was successful for at least 6 months. Encephalitozoon cuniculi survived 60 but not 120 min at 56 C. They were killed after 10 min of autoclaving and by 2% (v/v) Lysol, 10% (v/v) formalin and 70% (v/v) ethyl alcohol. The organisms survived at least 24 h at pH 9 or pH 4 and were not affected by sonication, freezing and thawing, or distilled water but lost significant infectivity after 24 h in CsCl or 40% (w/v) sucrose.
Cytotoxicity of Synthetic Fuel Products on Tetrahymena pyriformis. II. Shale Oil Retort Water*†‡
Authors: SCHULTZ T. WAYNE , DUMONT JAMES N. , KYTE LOLA M.
Published: May 2007

SYNOPSIS. Shale oil retort water is obtained by centrifuging the oil/water emulsion produced by oil shale retorting. The ciliate Tetrahymena pyriformis was exposed to retort water; 2, 1, and 0.5% initially increased motility; longer exposures decreased motility. Three, 4, and 5% all decreased motility. Cell lysis was directly related to concentration; after 24 h, population densities were 0, 10, and 25% of controls for 2, 1, and 0.5% retort water, respectively. Oxygen consumption paralleled the motility pattern: at lower concentrations it increased initially but decreased with extended exposures while at higher concentrations it decreased rapidly. The most striking cytologic alteration of cells exposed to the toxicant occurred in the membranes; alterations of mucocysts and glycogen content were also observed, but mitochondrial changes were not. Population growth was affected at much lower concentrations than the other test indices. The growth of test populations reached a plateau at values inversely related to concentration: concentrations <0.4% had no effect on growth rate.
Clonal Growth of Entamoeba histolytica and other Species of Entamoeba in Agar*
Authors: GILLIN FRANCES D. , DIAMOND LOUIS S.
Published: May 2007

SYNOPSIS. This is the first description of a method for growing axenized Entamoeba histolytica as colonies from single cells in agar suspension. Factors affecting the efficiency of colony formation included unknown characteristics of the amebal strain, age of cells used, and the type and concentration of agar employed. Colony formation was dependent upon filling deep vessels (culture tubes or tissue culture flasks) with agar, probably to maintain reduced oxygen tension, and upon solidifying the agar rapidly at 0 C. It was demonstrated in a study with the drug metronidazole that the agar colony method was useful for quantifying cell viability in drug testing.

Eleven of 12 E. histolytica strains tested, as well as one Entamoeba terrapinae, one Entamoeba barreti, and 3 Entamoeba invadens strains formed colonies in agar suspension. E. histolytica‐like amebae (Laredo type) and E. moshkovskii formed only tiny colonies in agar.