bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improved Method for Axenizing Blepharisma by Means of Antibiotics
Authors: MARTI EDUARDO J. , SLAVIN RONALD J. , HIRSHFIELD HENRY I. 
Published: May 2007

Synopsis.A simplified method for obtaining axenic cultures of Blepharisma involves the use of penicillin, streptomycin, and tetracycline. Cytologic examination disclosed no significant effect of these antibiotics on the structure of the ciliates.
Carotenes from Mutants of the Dinoflagellate, Crypthecodinium cohnii
Authors: WITHERS NANCY W. , TUTTLE ROBERT C. 
Published: May 2007

SYNOPSIS.The carotenoid compositions of 15 nitrosoguanidine‐induced mutants of Crypthecodinium cohnii, a heterotrophic dinoflagellate, were determined by chromatographic and mass spectral analyses. Wild‐type C. cohnii grown with irradiation of 250 m̈ W/cm2 visible light at 27 C synthesizes β‐carotene (33%) and γ‐carotene (67%) amounting to 0.083 mg/g dry wt. There are 4 types of carotenoid‐deficient mutants: (I) albinos which synthesize no C40‐carotonoids: (II) albinos blocked at the level of phytoene desaturation; (III) cream‐colored cells which accumulate mainly §–carotene, with phytoene and/or β‐zeacarotene also present; and (IV) light‐orange strains which synthesize reduced amounts of β‐carotene and γ‐carotene.Dark‐grown wild‐type cells produced 35% as much carotenoids as light‐grown cells. Inhibition studies revealed that diphenylamine (3 γ) caused phytoene accumulation; nicotine at 0.9 mM blocked the final cyclization, to cause γ‐carotene to accumulate in wild‐type cells. Inhibition by adenine and guanine (1.5 mM) of carotenogenesis was demonstrated for the first time in any system. The effect of these purines was similar to that of diphenylamine addition: phytoene desaturation was largely inhibited.The carotenogenic system in this dinoflagellate is similar to that of green algae and higher plants, and is under nuclear genetic control.
Respiratory Chain Components of Leishmania tropica Promastigotes*
Authors: MARTIN ELMER , MUKKADA ANTONY J. 
Published: May 2007

Synopsis.Crude preparations of kinetoplast vesicles were used to investigate the respiratory chain components in Leishmania tropica promastigotes. In difference spectra from enzymically and chemically reduced preparations, cytochrome b was the predominant component. By utilizing special assays designed to minimize the influence of cytochrome b on difference spectra, cytochromes a, a3, and c333 were demonstrated. Difference spectra from chemically reduced preparations indicated that pyridine nucleotides (NADH) and flavoproteins were also part of the respiratory chain. The presence of these components as well as their response to respiratory inhibitors and ascorbate provide evidence for the presence of a typical trypanosomatid respiratory chain in L. tropica promastigotes.
Agamococcidiorida ord. n. and Rhytidocystidae fam. n. for the Coccidian Genus Rhytidocystis Henneguy, 1907
Authors: LEVINE NORMAN D. 
Published: May 2007

SYNOPSISAgamococcidiorida ord. n. and Rhytidocystidae fam. n. are established in the apicomplexan subclass Coccidiasina for the genus Rhytidocystis Henneguy, 1907. Dehornia Porchet‐Henneré, 1972 is synonymized with Rhytidocystis.
Morphogenesis in the Heterotrich Ciliate Climacostomum virens. I. Oral Development During Cell Division
Authors: DUBOCHET C.‐F. , PECK R. K. , HALLER G. DE 
Published: May 2007

SYNOPSISThe principal characteristics of stomatogenesis during division in Climacostomum virens are: (A) Kinetosomal proliferation on the left side of a variable number of kineties in the ventral somatic cortex forms an oral primordium consisting of several kinetosomal fields, which then fuse to form a single anarchic field. (B) A constant topographical relationship exists between the primordium and a well defined cortical pattern, the zone of discontinuity. (C) The anarchic field primordium divides into 2 unequal parts—to the left, the AZM primordium, and to the right, the paroral primordium, which differentiates into the apical membranelles, the peristomial field, and the buccal tube. (D) Preoral and oblique kineties of the somatic cortex form along the right side of the paroral primordium. (E) Parental oral structures are partially dedifferentiated. Stomatogenesis in C. virens and other heterotrichs is compared.
Formation and Fate of Extranuclear Chromatin Bodies in Tetrahymena
Authors: SALAMONE MICHAEL F. , NACHTWEY D. STUART 
Published: May 2007

SYNOPSISThe fate of extranuclear chromatin bodies (ECBs) formed by exclusion of macronuclear material at the time of karyokinesis was followed quantitatively in Tetrahymena pyriformis strain GL‐I. In a logarithmic growth phase culture, 51% of the dividing cells produced one (43%) or more (8%) ECBs. Most of these gradually disappear before the next cell division, but ˜ 13% are retained and carried into subsequent cell cycles. The random distribution of ECBs into anterior or posterior daughter cells, their staining and morphological characteristics, and their rapid loss in cells in starvation medium, all indicate that ECBs play no more of a role in cellular activity than that of an internally produced food vacuole.
Temperature‐Sensitive Chlamydomonas Mutants Manifesting Flagellar Regression at a Restrictive Temperature‡
Authors: SHIOTA SUSUMU , SATO CHUBUN , ENOMOTO MASATOSHI 
Published: May 2007

SYNOPSISThe regeneration kinetics of Chlamydomonas reinhardtii mutants TS‐6 and TS‐79, whose flagella were mechanically amputated, indicated that the flagellar precursor in cytoplasm was used for regeneration when cycloheximide was present. The TS‐6 cells rendered nonflagellate by regression at 35 C did not regenerate in the presence of cycloheximide, indicating that the precursor was inactivated by the high temperature. Neither mutant was able to use the absorbed flagellar components for regeneration in the presence of cycloheximide.
Selection of Nonmotile Tetrahymena with Ficoll Underlayers*,†
Authors: MCGWIN NATALIE F. , HUFNAGEL LINDA A. 
Published: May 2007

SYNOPSISThe mechanisms regulating the development of cilia in Tetrahymena are poorly understood but might be revealed through the study of ciliogenesis mutants. Failure to regenerate cilia after dibucaine deciliation results in continued absence of motility. Therefore, to isolate ciliogenesis mutants efficiently, methods for separating motile and nonmotile cells are essential. We examined the efficacy of Ficoll underlayers for these separations. Ciliates of T. thermophila strain mpr‐/mpr (6 mp sens IV) (6‐methyl purine‐sensitive; mating type IV) were mixed with Ficoll and added as underlayers to separatory funnels containing growth medium. At 27 C most of the cells remained motile and were found in the top layer; at 37 C, there was a time‐dependent increase in the number of nonmotile cells and the number of cells in the Ficoll layer. After 150 min at 37 C, most of the cells became nonmotile and were found in the Ficoll layer. Other studies indicated that at 37 C, the cells remained alive and capable of regenerating cilia when deciliated. Thus, it is clear that the Ficoll underlayer effectively separates the majority of nonmotile cells from the majority of motile cells. Evidently, however, at 37 C wild‐type T. thermophila exhibit temperature‐sensitive phenotypic variability with regard to motility which should be minimized when selecting for mutations affecting motility and ciliogenesis.
Trichomonas vaginalis Resistance to Mengo Virus Infection*
Authors: EVA A. , VIANO I. , MARTINOTTI M. G. , CAPPUCCINELLI P. 
Published: May 2007

SYNOPSISWe have investigated the susceptibility of Trichomonas vaginalis to Mengo virus infection by comparing the outcome of Mengo virus or purified Mengo virus RNA infection in T. vaginalis and in CCL‐1 mouse fibroblasts. While the adsorption and entry of Mengo virus into T. vaginalis occurred in the same manner as in fibroblasts, the uncoating was much slower. In addition, Mengo virus infection of T. vaginalis displayed no eclipse nor any subsequent production of infectious virus. Purified RNA failed to initiate productive infection in T. vaginalis, whereas it provoked viral replication in the fibroblast controls. It was shown by assessment of protein synthesis in T. vaginalis and mouse fibroblasts cell‐free systems that the protozoan ribosomes were able to translate endogenous mRNA and poly‐U, but not viral RNA.
Studies on a Morphologically Distinct Colchicine‐Resistant Variant of Entamoeba sp.*
Authors: INJEYAN H. , HUEBNER E. , MEEROVITCH E. 
Published: May 2007

SYNOPSISColchicine has a temperature‐dependent cytotoxic effect on Entamoeba sp. (Laredo isolate) that is most apparent when the drug is applied during the initiation of cultures at a concentration of 7.5 mM or higher. Continued transfer of cultures in medium containing progressively increasing concentrations of colchicine has resulted in a variant that grows prolifically in the presence of colchicine (7.5 mM) with a generation time comparable to that of the parent stock. Comparison of a number of parameters of the 2 variants revealed that colchicine resistance was accompanied by a change in cell shape, a reduced membrane permeability, which could partially be overcome by the addition of dimethyl sulfoxide (DMSO), and a reduced tolerance to osmotic stress. However, the parent strain and resistant variant were equally susceptible to cycloheximide and puromycin suggesting that the acquired colchicine resistance may not be explained on the basis of an entirely unspecific generalized reduced ability for drug uptake.Colchicine resistance and altered structure were found to be stable over a long period of time. The possible interdependence of these 2 parameters and their relation to cell motility in Entamoeba sp. are discussed.
An Investigation of the Route and Progression of Encephalitozoon cuniculi Infection in Adult Rabbits
Authors: COX JOHN C. , HAMILTON ROSS C. , ATTWOOD HAROLD D. 
Published: May 2007

SYNOPSISRabbits infected either orally or intratracheally with cell culture‐grown Encephalitozoon cuniculi were monitored regularly for serum antibody levels and E. cuniculi in the urine. Their responses were compared with intravenously inoculated and uninoculated control rabbits.All rabbits receiving E. cuniculi developed serum antibodies, generally within 3 weeks, and excreted E. cuniculi by 6 weeks. In the acute stage of infection, the organs most affected were lung, kidney and liver; the brain and gut were unaffected. However, during chronic infection, the brain, kidney, and heart were the only organs found to be involved. Antibody levels were very high at this stage. Thus both the oral and tracheal routes may be normal routes of infection with E. cuniculi in adult rabbits.
Cryopreservation of Ochromonas in Liquid Nitrogen with Reproducibility of Thiamin Assay
Authors: McGRATH MARIAN SHARP , DAGGETT PIERRE‐MARC 
Published: May 2007

SYNOPSISThe first successful cryopreservation of Ochromonas danica and Ochromonas malhamensis is reported. The freezing method was consistently reproducible for the former, but not for the latter. Ochromonas danica cultures established from frozen material still could be used as test organisms for assay of thiamin. This is the first report of a protozoon retaining its assay property after being frozen to ‐196 C.
Growth Response of Axenic Entamoeba histolytica to Hydrogen, Carbon Dioxide, and Oxygen *,†
Authors: BAND R. NEAL , CIRRITO HELEN 
Published: May 2007

SYNOPSISEntamoeba histolytica required CO2 for growth in axenic culture while growth was inhibited by H2. The organism was tolerant to 5% O2 in the gas phase and it was able to detoxify products of O2 reduction in the medium. The ameba did not require a negative oxidation‐reduction potential for axenic growth. However, little or no free O2 was present in media exposed to 5% O2 in the gas phase. Growth was improved by adding yeast extract to the medium.
DNA‐Dependent RNA Polymerase III from Acanthamoeba castellanii: Comparison of the Catalytic Properties of the Trophozoite and Cyst Enzymes*
Authors: DETKE SIEGFRIED , PAULE MARVIN R. 
Published: May 2007

SYNOPSISDNA‐dependent RNA polymerase III was partially purified from trophozoites and immature cysts of the small soil ameba. Acanthamoeba castellanii. In contrast to the active modulation of the variety of transfer RNA species which are transcribed during encystment, no difference was found in the chromatographic or catalytic properties of the enzyme responsible for their transcription.
Plasmodium lophurae: Membrane Proteins of Erythrocyte‐free Plasmodia and Malaria‐Infected Red Cells*
Authors: SHERMAN IRWIN W. , JONES LYNN A. 
Published: May 2007

SYNOPSIS. Plasma membranes of normal duckling erythrocytes were prepared by blender homogenization and nitrogen decompression. Surface membrane vesicles of red cells infected with the avian malaria Plasmodium lophurae were produced by nitrogen decompression. Membranes of erythrocyte‐free malaria parasites were removed from cytoplasmic constituents by Dounce homogenization. These membranes were collected by centrifugation in a sucrose step gradient and purified on a linear sucrose gradient. Red cell membranes had a buoyant density of 1.159 g/cm3, whereas plasmodial membranes banded at 2 densities: 1.110 g/cm3 and 1.158 g/cm3. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis analysis of the isolated red cell membranes revealed 7 major protein bands with molecular weights (MW) ranging from 230,000 to 22,000, and 3 glycoprotein bands with MW of 160,000, 88,000 and 37,000. Parasite membranes also had 7 major bands with MW ranging from 100,000 to 22,000. No glycoproteins were identifiable in these membranes. The proteins of the surface membranes from infected red cells had MW similar to those from normal red cells; however, there was some evidence of a reduction in the amount of the high MW polypeptides. The red cell membrane contained 79 nmoles sialic acid/mg membrane protein, whereas plasmodial membranes had 8 nmoles sialic acid/mg membrane protein. The sialic acid content of the surface membranes of infected red cells was significantly smaller than that of normal cells. Lactoperoxidase‐glucose oxidase‐catalyzed iodination of intact normal and malaria‐infected erythrocytes labeled 7 surface components. Although no observable differences in iodinatable proteins were seen in these preparations, there was a striking reduction in the iodinatability of erythrocytic membranes obtained from P. lophurae‐infected cells. Erythrocyte‐free plasmodia bound very little radioactive iodine; the small amount of radioactivity was distributed among 3 major bands with MW of 42,000, 32,000 and 28,000.It is suggested that the alterations of the surface of the P. lophurae‐infected erythrocyte do not occur by a wholesale insertion of plasmodial membrane proteins into the red cell plasma membrane, but rather that there are parasite‐mediated modifications of existing membrane polypeptides.
Tetrahymena Tubulins and In Vitro Translation of Tetrahymena RNA*
Authors: FLISS EDWARD R. , SUYAMA YOSHITAKA 
Published: May 2007

SYNOPSIS. Tetrahymena outer doublet tubulin was compared with neurotubulin and Chlamydomonas flagellar tubulin on SDS‐polyacrylamide gels. Tetrahymenaα tubulin did not comigrate with either brain or flagellar α tubulins, although brain, flagellar, and ciliary β tubulins all comigrated. Axonemal tubulin from Tetrahymena strain ST was compared with this tubulin from strains W. S. HSM, and E, and all were found to have the same mobilities.Poly‐A containing RNA was separated from whole cell Tetrahymena RNA by oligo‐dT cellulose chromatography. Poly‐A+ RNA from 24‐h cultures (early exponential growth) stimulated greater incorporation of amino acids into polypeptides in the wheat germ cell‐free translation system than did poly‐A+ RNA from 36‐h and 49‐h cultures. When separated on SDS‐polyacrylamide gels, the translation products of the 24‐h poly‐A + RNA had 2 prominent protein bands which comigrated with α and β tubulin isolated from Tetrahymena cilia. These bands were not found in the translation products of poly‐A+ RNA isolated from 49‐h cultures or in the translation products ofpoly‐A‐ RNA.
Terrestrial Protozoa*
Authors: BAMFORTH STUART S. 
Published: May 2007

SYNOPSIS Litters and soils are special interstitial ecosystems containing water in surface films and pore spaces, large amounts of organic matter, and are subject to extreme moisture and temperature fluctuations. “Terrestrial protozoa” are ubiquitous limnetic species tolerant of high CO2 tensions and possessing efficient encystment mechanisms.Protozoa exploit tiny microhabitats unavailable to larger animals (e.g. nematodes). Naked amebae dominate due to their flexible bodies and interface locomotion. Small flagellates may be abundant, especially in litters. Ciliates are less numerous but their species composition indicates the degree of moisture of the habitat, as do the slower‐growing testacea which become prominent in regions of slow decomposition (conifer and tundra biomes). Protozoa promote decomposition by enhancing bacterial metabolism, eating excess bacteria, and excreting simple compounds returnable to plants. Large populations, especially amebae, exploit the abundant bacterial flora of plant root zones (rhizosphere). One protozoon, Colpoda cucullus, has successfully invaded the surfaces of vegetation.
Role of Glycerol Permeation in the Bloodstream Form of Trypanosoma brucei*
Authors: GRUENBERG JEAN , SCHWENDIMANN BERNARD , SHARMA PUKH RAJ , DESHUSSES JACQUES 
Published: May 2007

SYNOPSIS. Under aerobic conditions, we have determined glycerol uptake in the long slender (LS) bloodstream form of Trypanosoma (Trypanozoon) brucei brucei by studying glycerophosphate accumulation in the parasites. The coupled enzyme theory applies to the permeation‐phosphorylation sequence. Glycerol passage through the plasma membrane is asymmetric, the efflux process being favored over the influx process. No free diffusion of glycerol can be detected even under conditions under which free glycerol accumulates within the cells; most probably, glycerol permeation is mediated by a specific transport system. In the absence of respiratory activities, glycerol is known to be an end‐product of T. brucei glycolysis; its production from glycerophosphate should allow ATP synthesis. The observed efflux of free glycerol following intracellular accumulation of glycerophosphate confirms the hypothesis that glycerol production occurs through reversal of glycerol kinase activity.We conclude that in vivo the role of the carrier‐mediated asymmetric permeation process is to prevent inhibition of the reversal of the glycerol kinase‐mediated reaction by removing free glycerol.
The Chemotherapy of Protozoal Infections of Veterinary Importance1
Authors: JOYNER L. P. 
Published: May 2007

ABSTRACTThe use of drugs in domestic animals is dominated by considerations of cost‐effectiveness and profitability. They are extensively used against coccidial infections of poultry where they are an important factor in intensive husbandry. Ionophore antibiotics, which dominate this field, may have applications in ruminants. Imidocarb is of therapeutic and prophylactic value against babesial infections and there are new prospects for control of theileriasis. Effective drugs for the control of African trypanosomiasis are limited and attention is being given to alternative uses of available compounds.
The Chemotherapy of Protozoal Infections: Whither?1
Authors: STECK EDGAR A. 
Published: May 2007

ABSTRACTAn assessment is given of the present state of the art in chemotherapy of protozoal infections with suggestions as to improved results in the future, especially by rendering available drugs more effective. Selective targeting of chemotherapeutic agents through enhancement of lysosomotropic character has been demonstrated, particularly through the use of liposome‐encapsulated drugs.
A Study of Choanoflagellates (Acanthoecidae) from the Weddell Sea, Including a Description of Diaphanoeca multiannulata n. sp.1
Authors: BUCK KURT 
Published: May 2007

ABSTRACTEight species of loricate choanoflagellates (Acanthoecidae), Acanthoecopsis spiculifera Norris, Bicosta antennigera Moestrup, Bicosta spinifera Throndsen, Calliacantha multispina Manton & Oates, Calliacantha simplex Manton & Oates, Crinolina aperta Leadbeater, Diaphanoeca multiannulata n. sp., and Parvicorbicula socialis (Meunier) Deflandre, have been observed, by light and electron microscopy, in samples obtained from the Weddell Sea during the austral summer of 1977. Diaphanoeca multiannulata is described for the first time from these samples: the other organisms are discussed. The distribution of most species within the Weddell Sea was widespread. Habitats in which choanoflagellates were found included the water column, the edge of (or ponds on) ice floes, and the interior of ice floes. The distributional, environmental, habitat, and/or morphological range of all previously described species is expanded. Methods of variation of transverse costal diameters between genera may be potentially useful to the understanding of taxonomy and phylogeny of this family.
Bottled Mineral Waters Polluted by Protozoa in Mexico
Authors: RIVERA FERMÍN , GALVÁN MATILDE , ROBLES ESPERANZA , LEAL PILAR , GONZÁLEZ LETICIA , LACY ANA MARÍA 
Published: May 2007

ABSTRACTA survey of protozoa polluting bottled mineral water in Mexico was carried out using samples obtained from the three best‐selling brands of bottled mineral water in the country. The organisms were concentrated through filtration procedures and subsequently cultured in sterile media. The cultures were observed over four weeks, with identification to the level of genus and species. Most commonly found were the amoebae Naegleria gruberi, Acanthamoeba astronyxis, and Vahlkampfia vahlkampfi (trophic as well as cystic stages) plus one flagellate, Bodomorpha minima. No ciliates were detected. The public health importance of the findings is obvious, since some strains of Naegleria and Acanthamoeba have the potential to cause human disease that may lead to death.
Life Cycle of Eimeria christenseni Levine, Ivens & Fritz, 1962 from the Domestic Goat, Capra hircus L.1
Authors: LIMA JOSÉ D. 
Published: May 2007

ABSTRACTThe endogenous development of Eimeria christenseni was studied in 10 two‐ to four‐week‐old kids inoculated with 106‐107 sporulated oocysts. They were killed at intervals from two to 26 days after inoculation, and their tissues were examined for endogenous stages of the coccidian by light microscopy. Such stages were found in the small intestine and mesenteric lymph nodes. In the sexual cycle, two generations of meronts were found. The first generation developed in endothelial cells of lacteals in the jejunun and ileum and mesenteric lymph nodes, and mature meronts were first seen 14 days after inoculation. The second generation developed in epithelial cells of the glands of Lieberkuehn in the jejunum and ileum and in mesenteric lymph nodes, and its mature meronts were first seen by 16 days. Sexual stages were present mostly in epithelial cells of the tips and sides of the villi and less frequently in crypt cells of the jejunum and ileum. Mature macrogametes and microgamonts and oocysts were also first seen by 16 days. The prepatent period was 17 (14‐23) days; the patent ranged from 8 to more than 30 days. Sporulation time was 3‐4 days at 30°C. E. christenseni was found to be pathogenic, kids inoculated with 1‐5 × 105 sporulated oocysts exhibited the following signs: severe diarrhea, anorexia, polydipsia, poor hair coat, and extreme weakness. They recovered about a month later, but their growth rates appeared to be lower than those of uninoculated animals kept under the same conditions. One kid died 20 days after inoculation with 107 oocysts.