bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Cyclophosphamide on Visceral Leishmaniasis in the Mouse*
Authors: HERMAN ROBERT , FARRELL JAY P.
Published: May 2007

SYNOPSIS Cyclophosphamide (Cy), 125 or 200 mg/kg body weight, injected intraperitoneally (i.p.) into BALB/c mice one day before infection with amastigotes of Leishmania donovani, by the 8th day postinfection caused a significant decrease in the mean numbers of parasites in spleens and livers when compared to mice injected with phosphate buffered saline (PBS). When 125 mg/kg was injected into chronically infected mice (on day 34 of infection), however, within 2 days (day 36) mean parasite levels in both the spleens and livers were statistically greater than in PBS‐treated controls. Similarly, when a series of 6 Cy injections, 50 mg/kg each, was injected over a period of 8 days during the chronic stage of infection, the mean parasite levels in both spleens and livers were significantly increased over those of PBS‐treated controls. Druing the chronic stage of infection, Cy injections suppressed the immunity to superinfection.

Neither plasma nor parasitized peritoneal macrophages obtained from Cy‐treated mice, when compared to PBS‐treated mice, differed in their respective capacities to influence the growth of intracellular amastigote of L. donovani in vitro. Passive transfer of hyperimmune mouse serum could not reverse the immunosuppressive effects of Cy upon chronic leishmaniasis in the mouse.

It is suggested that neither readily demonstrable anti‐leishmanial humoral factors nor “immune” macrophages per se, plays a major role in acquired immunity to leishmaniasis in the mouse.
Regulation by Ammonium of Variation in Heterotrophic CO2 Fixation by Euglena gracilis During Growth Cycles*
Authors: PEAK J. G. , PEAK M. J.
Published: May 2007

SYNOPSIS Heterotrophic (dark) CO2 fixation by Euglena gracilis strain Z varies with phase of batch culture growth and mode of nutrition. Increases in the fixation during growth cycles correlate closely with the depletion of exogenous NH4* from the medium during growth. It is demonstrated that exogenous NH4+ regulates a component of heterotrophic CO2 fixation and that another component is independent of NH4+. This is true for cells grown heterotrophically (glucose, dark), autotrophically (CO2, light) and for a permanently bleached strain (E. gracilis SB3). Some kinetics of the NH4+ regulation are presented.
Identification of Leishmania spp. by Radiorespirometry
Authors: DECKER JOAN E. , SCHROT J. RUDOLPH , LEVIN GILBERT V.
Published: May 2007

SYNOPSIS Preliminary investigation of the application of radiorespirometric technic to protozoan parasites of man indicates a potential for rapid identification. This technic, developed for identification of bacteria, was modified for use with culture forms of Leishmania. Five strains of Leishmania were compared: 2 of L. donovani, 2S and K; L. brasiliensis, 2936 and B; and 1 of L. tropica, A. Consistent and rapid (2 hr) identification was obtained by the radiorespirometric procedure. A computer‐type analysis of the radiorespirometric profiles of the 5 strains permitted correct identification of each isolate at the strain level 100% of the time. This technic offers several advantages over many current procedures for identification of protozoan parasites: (A) It is simple, rapid and highly reproducible. (B) Since it does not rely on visual or spectrophoto‐metric determination, it may be conducted in the presence of optically complex substances. (C) It requires relatively low numbers of organisms (2 × 105/14C‐labeled substrate). (D) It is based on differential enzymic activity between species and strains of organisms and therefore, ultimately, on inherent genetic determinates of the parasites. (E) Further development of the procedure and accumulation of a data reference “bank” would allow automation of most of the identification process.
Biochemical Approaches to Problems of Cellular Patterning*†
Authors: WILLIAMS NORMAN E.
Published: May 2007

SYNOPSIS. The expression of intracellular patterning is perhaps nowhere more impressive than in the arrangements of structural elements associated with the cell surface in protozoa. The view is proposed that biochemical studies of protozoan plasma membranes and associated surface structures represent important contributions of potential significance for the understanding of the perpetuation, and expression of positional information at the intracellular level. Some recent work dealing with the isolation, identification, and metabolism of pellicular proteins in Tetrahymena is presented and discussed. Some integral membrane proteins have been identified by iodination and polyacrylamide gel electrophoresis. Labeling studies suggest heterogeneous turnover rates within the group of presently identified membrane proteins. High molecular weight proteins with some similarity to spectrin have been isolated from Tetrahymena epiplasm. It is suggested that the ciliate epiplasm is one example of membrane‐associated, actomyosin‐like systems found in a variety of cell types. The epiplasm may play a role in the positioning of surface‐associated structures and in the control of cell shape.
Regulation of Ciliary Pattern in Ciliates*
Authors: JERKA‐DZIADOSZ MARIA , GOLINSKA KRYSTYNA
Published: May 2007

SYNOPSIS. The modes of pattern regulation found in the ciliates Dileptus and Paraurostyla are compared. These forms are systematically distant but both possess very extensive regenerative capacities. They are characterized by 2 types of ciliary patterns: the ciliature of Dileptus has largely a simple pattern composed of single kinetosomes while that of Paraurostyla has a complex pattern composed of aggregates of kinetosomes interconnected by amorphic matter. In both ciliates a change in cell size evokes pattern regulation which differs substantially in the extent of pattern replacement, timing, and localization of morphogenetic activities. It is concluded that these differences result from the pattern constituents.
Taxonomy of Toxoplasma*
Authors: LEVINE NORMAN D.
Published: May 2007

SYNOPSIS. After reviewing reports of the hosts, structure and life cycle of Toxoplasma, the genus is placed in the apicomplexan family Eimeriidae and the following 7 species are recognized: Toxoplasma gondii (Nicolle & Manceaux) (type species) from about 200 species of mammals and birds, with oocysts in felids; Toxoplasma alencari (Da Costa & Pereira) from the frog Leptodactylus ocellatus; Toxoplasma brumpti Coutelen from the iguana Iguana tuberculata; Toxoplasma colubri Tibaldi from the snakes Coluber melanoleucus and Coluber viridiflavus; Toxoplasma hammondi (Frenkel & Dubey) (a new combination for Hammondia hammondi) from the house mouse with oocysts in the domestic cat; Toxoplasma ranae Levine & Nye from the leopard frog Rana pipiens; and Toxoplasma serpai Scorza, Dagert & Iturriza Arocha from the toad Bufo marinus.
Qualitative and Quantitative Studies on DNA and RNA Synthesis in Loxodes striatus Nuclei*
Authors: RON A. , URIELI S.
Published: May 2007

SYNOPSIS. In this study the characteristics of the synthesis of DNA and RNA in the nuclei of Loxodes were investigated. Loxodes striatus is a primitive ciliate with 2 pairs of structurally differentiated diploid nuclei, the macro‐ and micronuclei. The macronuclei are differentiated morphologically into a clearly recognizable central core and an outer zone.

To determine DNA and RNA synthesis, individual organisms were analyzed by autoradiography after incubating groups of cells with a 3H‐labeled precursor ([3H]thymidine for DNA and [3H]uridine for RNA).

The following observations were made: (A) All portions of macro‐ and micronuclei appeared to contain DNA as judged by the localizations of incorporated [3H]thymidine. (B) The macro‐ and micronuclei did not synthesize DNA at the same time; moreover, the duration of DNA synthesis in the former was much longer than of the latter nucleus. (C) Replication of DNA in the inner core and outer zone of the macronucleus occurred at separate times with little if any overlap. (D) All of the detectable [3H]uridine incorporation was found in the macronucleus and none in the micronucleus. Within the macro‐nucleus the central core was more heavily labeled. (E) The quantitative differences in the label of the different components of the nuclear complex were investigated. (F) Contrary to the previously reported information our results suggest that DNA synthesis can occur in adult macronuclei.

The possible explanation of these results is discussed in the context of the nuclear evolution of ciliates and of recent information on nuclear differentiation.
Eimeria dispersa and Eimeria gallopavonis: Infectivity, Survival, and Development in Primary Chicken and Turkey Kidney Cell Cultures
Authors: DORAN DAVID J. , AUGUSTINE PATRICIA C.
Published: May 2007

SYNOPSIS. Eimeria dispersa (turkey strain) and Eimeria gallopavonis sporozoites were inoculated into primary cultures of chicken kidney (CK) and turkey kidney (TK) cells. Eimeria dispersa sporozoites were more infective in either cell type than those of E. gallopavonis: at 4 hr, the percentage of infection was 67‐98 for E. dispersa but only 23‐56 for E. gallopavonis. E. dispersa also survived better in culture: at 2 days, losses of E. dispersa in both cell types were only 4‐19%, whereas losses of E. gallopavonis were 35‐47% in TK cells and 60–95% in CK cells. However, E. gallopavonis developed further than E. dispersa. Location and increase in numbers of intracellular stages at 4 days indicated that E. dispersa proceeded through 2 schizogonic generations before development stopped.
The Effects of Heat and Cobalt‐60 Gamma‐Radiation on Excystation of the Rat Coccidium, Eimeria nieschulzi Dieben, 1924*
Authors: CONDER GEORGE A. , DUSZYNSKI DONALD W.
Published: May 2007

SYNOPSIS. Sporulated oocysts of Eimeria nieschulzi Dieben, a rat coccidium, were exposed for 1 hr to Cobalt‐60 γ‐radiation (15, 30. or 60 k‐rads), to heat (35, 40, or 45 C). or to both concurrently (15, 30, or 60 k‐rads at 35 C) to compare the excystation capabilities of treated vs nontreated parasites. Intact, treated oocysts appeared structurally unaltered when viewed with the light microscope. Excystation of sporozoites occurred in all treated groups when their sporocysts were exposed to a trypsin‐sodium taurocholate (TST) fluid, but after 150 min in TST the excystation rate was significantly lower than in non‐treated sporocysts. Sporozoites which excysted from treated sporocysts were abnormal both in the excystation process and in their form and movement once outside the sporocyst.
Effect of Ethidium Bromide on the Oxidative Metabolism and Enzyme Profiles of Crithidia fasciculata*
Authors: MANAIA ARMANDO DA COSTA , ROITMAN ISAAC
Published: May 2007

SYNOPSIS. Changes in the metabolism of Crithidia fasciculata ATCC 11745 when grown in the presence of ethidium bromide were studied. Ethidium bromide‐grown cells had decreased respiratory activity as measured by oxygen consumption. More than 50% of the organisms cultivated in a defined medium containing 1.0 mg/liter of ethidium bromide became dyskine‐toplastic and had decreased activities of particulate succinate and NADH‐linked dehydrogenases as well as of soluble isocitrate dehydrogenase. These cells also had increased activities of particulate α‐glycerophosphate dehydrogenase, soluble α‐glycerophosphate dehydrogenase, malic enzyme, hexokinase, and malate dehydrogenase. Ethidium bromide‐grown cells had a lower level of ATP and contained less DNA than cells grown in its absence.
New Family, Genus, and Species of Microsporida (Protozoa: Microsporida) from the Tropical Fire Ant, Solenopsis geminata (Fabricius) (Insecta: Formicidae)*
Authors: JOUVENAZ D. P. , HAZARD E. I.
Published: May 2007

SYNOPSIS. A new species of Microsporida, Burenella dimorpha sp. n., representing a new family, Burenellidae fam. n. and genus, is described on the basis of light‐ and electron‐microscope observations. The family is characterized by 2 sequences of sporogony, each sequence having morphologically different sporonts and spores. The parasite infects the tropical fire ant, Solenopsis geminata (Fabricius), producing distinct pathologic manifestations (clearing of the cuticle and eye malformation) and death in the pupal stage of development. Transmission of the infection per os to healthy S. geminata, to the Southern fire ant, Solenopsis xyloni McCook, and to the red and black imported fire ants, Solenopsis invicta Buren and Solenopsis richteri Forel, is reported.
Promitosis and Rod Occurrence in the Limax Ameba Vahlkampfia lobospinosa*
Authors: FIZER EMERSON R. , WILHELM WALTER E.
Published: May 2007

SYNOPSIS. Nuclear division and trophozoite structure and function were investigated in Vahlkampfia lobospinosa. During karyokinesis the nucleolus remained present and divided to form polar masses. Chromatids separated and were directed to the polar masses by spindle fibers within an intact nuclear membrane. No interzonal body was formed.

Trophozoites consistently contained and extruded a rod‐like structure 10–15 × 1–2 μm. Although it was found in other areas of the cell within the cytoplasm, this rod most frequently protruded from the uroid.
Successful Demonstration of an Elusive Cell Coat in Amebae*
Authors: DYKSTRA MICHAEL J. , ALDRICH HENRY C.
Published: May 2007

SYNOPSIS. Cell coats were cytochemically demonstrated for the first time in myxamebae of Fuligo septica, Didymium iridis, Dictyostelium discoideum, Cavostelium apophysatum, and amebae of Naegleria gruberi. The stain enhances the cell coats of Physarum polycephalum plasmodia, Ceratiomyxa fruticulosa myxamebae, and Acanthamoeba sp. Cell coats usually unstained by cationic dyes stain intensely with the aid of the new cytochemical protocol utilizing 0.5% Alcian blue in the primary fixative and 0.05% ruthenium red in the secondary fixative.
Unusual Multiple Fission in the Gamont of the Larger Foraminiferan Heterostegina depressa*
Authors: RÖTTGER RUDOLF
Published: May 2007

SYNOPSIS. In the larger foraminiferan, Heterostegina depressa d'Orbigny, new gamonts form directly from adult gamonts by multiple fission. The life of the parent gamont, however, is not always ended by this process. Residual protoplasm which remains inside the parent gamont test during reproduction may grow again and reoccupy the test. Such individuals can add new chambers and are able to reproduce a 2nd time. The oldest individual observed was 32 months of age; it reproduced at 8 months.
Ultrastructure of the Genus Schizoplasmodiopsis (Protostelia)*
Authors: DYKSTRA MICHAEL J.
Published: May 2007

SYNOPSIS. Two basic types of spore wall structures were observed in ultrastructural examination of Schizoplasmodiopsis micropunctata, Schizoplasmodiopsis pseudoendospora, Schizoplasmodiopsis reticulata, and Schizoplasmodiopsis vulgare. The spores of S. micropunctata, S. pseudoendospora, and S. vulgare had walls bearing electron‐dense protrusions, while those of S. reticulata had walls with irregular thickenings. Prominent cytoplasmic features included 2 types of vesicles and electron‐dense bodies studded with ribosomes. The ameboid phase of all species lacked the electron‐dense bodies and, unlike the dormant phases, did not have mitochondrial surfaces covered with ribosomes.
The Structure and Morphogenesis of the Ventral Ciliature in Paraurostyla hymenophora*
Authors: GRIMES GARY W. , L'HERNAULT STEVEN W.
Published: May 2007

SYNOPSIS. The structure and morphogenesis of the ventral ciliature of Paraurostyla hymenophora (Stokes) are described. The oral primordium apparently originates in association with transverse cirrus #6, from which it migrates anteriorly simultaneous with kinetosomal proliferation. The primordium eventually forms an elongate ciliary field from which the future opisthe's fronto‐ventro‐transverse (FVT) and undulating membrane primordial fields arise. Concomitantly, the future proter's FVT primordial field is initiated by the disaggregation of frontal cirri #4, #5, and #6. Primordia then develop simultaneously within marginal and ventral cirral rows by a disaggregation of cirri within the respective rows, and do not give rise to new cirri until the FVT fields complete segregation into discrete cirri. Near the completion of cirral production from the FVT primordia, each ventral cirral primordium (VCP) forms the 2 rightmost transverse cirri. Segregation of new cirri within the marginal cirral primordia and VCP then occurs, eventually replacing all old cirri within their respective marginal and ventral cirral rows. At the end of cortical morphogenesis, all old ciliary organelles, with the exception of the adoral zone of membranelles, are either reorganized or replaced.

These results suggest an evolutionary affinity between the ventral and marginal cirral rows and raise questions about the control of the developmental competence of individual primordia.
Feeding and Mating Reactivity in Paramecium multimicronucleatum
Authors: MISHIMA SHOJI
Published: May 2007

SYNOPSIS. Paramecium multimicronucleatum produced abnormal (L‐ and Δ‐shaped) cells when cultivated in the presence of 3 mM adenine. These abnormal cells were unable to form food vacuoles in the presence of bacteria in the culture. In bacteria‐rich culture, mating reactivity was not expressed in normal Paramecium; however, it was expressed in the adenine‐treated abnormal cells even in the presence of excess bacteria. The expression of mating reactivity in Paramecium was not affected by ingestion of polystyrene latex particles. These results show that the inhibition of mating reactivity in bacterized culture medium is caused by absorption of nutrients from bacteria digested in food vacuoles.
Artificially Induced Symbiosis Between Marine Flagellates and Vertebrate Tissues in Culture*
Authors: TAYLOR DENNIS L.
Published: May 2007

SYNOPSIS. Algal symbiotes isolated from marine invertebrate hosts, and grown axenically in culture, have been successfully combined in artificial associations with chick fibroblasts and grunt (Haemulon sp.) fin explants. Growth (measured by cell numbers and chlorophyll a) is stimulated in both symbiotes and host cells. Studies of nitrogen uptake and exchange suggest that these artificial associations are similar to other, natural symbioses involving invertebrate hosts, e.g. the hermatypic corals.
Transmission of Salmonid Whirling Disease by Birds Fed Trout Infected with Myxosoma cerebralis
Authors: TAYLOR ROBERT L. , LOTT MARLEY
Published: May 2007

SYNOPSIS. Mallard ducks, Anas platyrhynchos and a black crested night heron, Nycticorax nycticorax were fed trout infected with Myxosoma cerebralis (Hofer) in 2 separate experiments. Feces from the birds were deposited in troughs containing M. cerebralis‐free mud as well as in 1 trough without mud. Spore suspensions were also added directly to mud in 1 trough and to another trough without mud. Susceptible rainbow trout, Salmo gairdneri, developed whirling disease in all troughs containing mud contaminated with M. cerebralis but remained free of infection when exposed to M. cerebralis in troughs without mud. This demonstrates the possibility of bird transmission of the organism causing whirling disease to previously non‐contaminated waters.
An Experimental Investigation of Bioconvection in Three Species of Microorganisms*
Authors: FORNSHELL JOHN A.
Published: May 2007

SYNOPSIS. A series of experiments was carried out on bioconvection using cultures of Polytomella agilis, Tetrahymena pyriformis and Chlamydomonas moewusii. During convection these microorganisms disperse into more and less dense regions causing visible patterns. These patterns, called the cell plan forms, were found to change with increasing Rayleigh numbers above Rc, the lowest concentration gradient at which bioconvection occurs. Hexagonal convection cells were observed near the critical Rayleigh number, Rc. As the Rayleigh number was increased the cell plan form changed from hexagons to 2‐dimensional rolls and then to square convection cells. The size of the observed convection cells was less than expected for such a physical phenomenon. This appears to result from an increasing tendency of the microorganisms to circulate near the upper surface at higher Rayleigh numbers. The square convection cells appear to be unique to bioconvection. The inhibition of bioconvection is directly linked to an increased mortality rate. Observations on the nature of negative geotaxis were made which tend to support the statocyst hypothesis.
Mitosis in the Hemoflagellate Trypanosoma cyclops*
Authors: HEYWOOD PETER , WEINMAN DAVID
Published: May 2007

SYNOPSIS. The ultrastructure of interphase and mitotic nuclei of the epimastigote form of Trypanosoma cyclops Weinman is described. In the interphase nucleus the nucleolus is located centrally while at the periphery of the nucleus condensed chromatin is in contact with the nuclear envelope. The nucleolus fragments at the onset of mitosis, but granular material of presumptive nucleolar origin is often recognizable in the mitotic nucleus. Peripheral chromatin is in contact with the nuclear envelope throughout mitosis, and it seems reasonable to assume that the nuclear envelope is involved in its segregation to the daughter nuclei. Spindle microtubules extend between the poles of the dividing nucleus and terminate close to the nuclear envelope. The basal body and kinetoplast divide before the onset of mitosis and do not appear to have any morphologic involvement in that process. Spindle pole bodies, kinetochores, and chromosomal microtubules have not been observed.
Motility Events of Trichocyst Insertion in Paramecium tetraurelia*
Authors: AUFDERHEIDE KARL J.
Published: May 2007

SYNOPSIS. Following electroshock‐induced extrusion of its inserted trichocysts, Paramecium tetraurelia rapidly begins replacement of the population of lost organelles. Light microscopy of the cortical insertion of new trichocysts reveals a series of characteristic motility activities. An uninserted trichocyst in the cyclotic flow of the cell appears to be “captured” and removed to the noncyclotic, subcortical regions. The trichocyst then makes a series of saltatory motions which apparently serve to transport it to the cortex, with proper orientation (tip first) for insertion. Trichocyst saltations end with either cortical insertion of the organelle, or return to cyclosis. If the trichocyst is inserted, it makes a series of unique pivoting movements around the motionless tip. This form of motility, termed “wobble,” continues for a short period of time. After cessation of wobble, the insertion of the trichocyst is apparently complete, since no further motility is observed. With the aid of these observations it was possible to identify saltatory motility as the means for transporting trichocysts to the cortex for insertion, and also to observe a motility of unknown significance (wobble) apparently associated with the process of cortical insertion.
Intestinal Transit Time During Infection with Eimeria nieschulzi in Rats*
Authors: DUSZYNSKI D. W. , ROY S. A. , STEWERT J. , CASTRO G. A.
Published: May 2007

SYNOPSIS. Experiments were designed to test whether or not intestinal transit time increases significantly during severe coccidiosis in the rat. Intraduodenal catheters were surgically implanted into 25 rats. Six to 12 days after surgery 11 rats were inoculated orally with 104 sporulated oocysts of Eimeria nieschulzi Dieben, and 11 were inoculated with 106 oocysts; 3 rats were retained as uninfected controls. At 2, 4, 8, 9, and 16 days postinoculation (PI) Na251CrO4 was injected through the catheter into the duodenum of fasted rats and allowed to progress through the small bowel for 15 min, at which time the rats were killed. The distribution of 51Cr in the gut was plotted as a function of gut length. The leading edge of radioactivity traversed 70% of the gut length in controls, and ∼ 50–60% in parasitized rats on days 2, 4, 8, and 9 PI. Also, a reflux of gut contents, as evidenced by radioactivity in the stomach, occurred early (PI days 2 & 4) in rats infected with 104 oocysts and throughout patency in rats infected with 106 oocysts.

A 2nd study was undertaken to determine if chemically induced suppression of gut transit time during early infection would enhance infectivity as measured by increased parasite fecundity. Nine rats were injected subcutaneously with an antidiarrheal agent, Loperamide®, known to slow small bowel motility significantly. Another group of 9 control rats was injected with the ethanol‐propylene glycol solvent. Ten min after injection, all rats were inoculated per os with 104E. nieschulzi oocysts. The daily number of oocysts discharged/rat was followed from PI days 5–11. Patency began for all rats on PI day 7. The total number of oocysts discharged by the drugged rats as compared with controls was not significantly different.
Herpetomonas mariadeanei sp. n. (Protozoa, Trypanosomatidae) from Muscina stabulans (Falléen, 1816) (Diptera, Muscidae)*
Authors: YOSHIDA N. , FREYMÜLLER E. , WALLACE F. G.
Published: May 2007

SYNOPSIS. A trypanosomatid flagellate was isolated from the musciod fly Muscina stabulans (Fallén). Cloned cultures of this organism contained promastigotes, opisthomastigotes, and froms containing a long flagellum doubled or coiled within the cell but not protruding outside. These latter forms we are designating endomastigotes. The presence of these hitherto underscribed endomastigotes along with other morphologic and growth characteristics suggest that this is a new species for which the name Herpetomonas mariadeanei is proposed.
Ultrastructure of Excystment of Toxoplasma gondii Oocysts*
Authors: CHRISTIE EMANUEL , PAPPAS P. W. , DUBEY J. P.
Published: May 2007

SYNOPSIS. The excystation of sporozoites from intact Toxoplasma gondii oocysts or mechanically released sporocysts was studied by light and electron microscopy. Both intact oocysts and free sporocysts excysted in 5% bovine bile in 0.9% NaCl solution after 30–60 min incubation at 37 C. Sporozoites were first activated in either intact sporocysts or oocysts within 2–12 min of incubation in bile. Sporozoites escaped from sporocysts through 4 plate‐like sutures in the sporocyst wall, and from the oocyst as the oocyst wall ruptured at one or more points.
The Contractile Vacuole of Amoeba proteus. II. Numerical Analysis of the Steady‐State Hypothesis*
Authors: BOURDEAU M. , LABONTE G. , AHMAD M. , COUILLARD P.
Published: May 2007

SYNOPSIS. At temperatures below 15 C, the contractile vacuole cycle of Amoeba proteus includes a presystolic plateau. The hypothesis attributing this plateau to a steady‐state equilibrium between active filling processes and osmotic losses of water from the vacuole into the cytoplasm has been expressed in an equation predicting vacuolar diameter as a function of time for the later part of the cycle. Computer‐generated model cycles have been compared with actual recorded cycles at 15 C, 10 C and 5 C and conditions of best fit were determined. Statistical analysis shows that recorded cycles are quite compatible with the steady‐state hypothesis.
Mutants of Acanthamoeba castellanii Resistant to Erythromycin, Chloramphenicol, and Oligomycin
Authors: SEILHAMER JEFFREY J. , BYERS THOMAS J.
Published: May 2007

SYNOPSIS. Cell lines of Acanthamoeba castellanii resistant to erythromycin (EryR), chloramphenicol (CapR), and oligomycin (OliR) have been isolated. These may be the first such mutants for A. castellanii. These mutants have been phenotypically stable for 2 years, surviving storage and vegetative multiplication in the absence of drugs. Resistance was specific for each drug, but double mutants (e.g. EryRCapR) were obtained by stepwise selection. Mutant frequencies were determined in multiwell plates; <10 colony forming units (CFU/105 amebas were observed in wild‐type populations 12 days after incubation in 500 μg Ery/ml, 2.5 mg Cap/ml, or 15 μg Oli/ml. After 30 days, averages of 100 CFU/105 amebas were observed in Ery and Cap, whereas, frequencies for Oli remained unchanged. Frequencies for EryR and CapR were consistent with rates of recovery from these drugs in batch cultures. We were unable to obtain spontaneous mutants resistant to cycloheximide, emetine, 5‐fluorodeoxyuridine, or ethidium bromide. EryR, CapR and OliR could be mitochondrial mutants.
Induction of Encystment in Acanthamoeba palestinensis. Factors Influencing Cyst Formation
Authors: LASMAN M. , SHAFRAN A.
Published: May 2007

SYNOPSIS. The effect of osmotic pressure, different electrolytes and organic compounds on cyst formation in Acanthamoeba palestinensis has been tested. The optimal osmolarity for encystment was similar to that of the growth medium. Iso‐osmotic solutions of NaCl, KCl, MgCl2, CaCl2, glycine and sucrose led to maximum cyst formation. The involvement of various agents in the induction of encystment is discussed.
Dense Crithidia Growth and Heme Sparing: Relation to Fe, Cu, Mo Chelation*
Authors: SHAPIRO ANNA , HUTNER S. H. , KATZ LILLIAN , BACCHI C. J. , O'CONNELL TAMBURRO KATHLEEN , BAKER HERMAN
Published: May 2007

SYNOPSIS. Heme, intrinsically required by Trypanosomatidae, is unstable, especially in conventional alkaline (pH 7.2–8.0) media. Low solubility of heme in a pH 6.5 basal medium (developed to assay biopterin with Crithidia fasciculata) posed a problem: in media acidified during growth because of glycolysis, heme precipitated, perhaps contributed to acid‐limited growth and interfered with densitometric estimation of growth. The remedy was to: replace glucose with less rapidly metabolized mannitol; distribute media in thin layers to promote oxidation of acetate, fumarate, and malate (presumably leaving an alkaline residue); and buffer heavily with histidine + Good zwitterionic buffers, and superimpcse physiological buffering by arginine + asparagine whose catabolism appeared to yield an excess of NH+4 over acid. Thereupon, Fe and Cu deficiencies sharply limited growth in the medium whose main chelators were: (a) 2,3–dihydroxybenzoic + 5‐sulfosalicylic acids (which preferentially bind transitional elements at their higher valences; (b) malic and gluconic acids; and (c) histidine. With unconventionally heightened concentrations of Fe, Cu, and Mo (the latter serving as Cu buffer as well as nutrient per se), the hemin concentration could be lowered, widening the margin of safety for heme solubility. Growth then reached 1.4 × 108 cell/ml. This medium may serve to screen for ligands promoting uptake or release of Fe and Cu. The increased growth is a step towards improving the assay medium for biopterin and practical use of Crithidia to assay several B vitamins and essential amino acids for metazoa.
Eimeria tenella: Vitamin Requirements for Development in Primary Cultures of Chicken Kidney Cells
Authors: DORAN D. J. , AUGUSTINE P. C.
Published: May 2007

SYNOPSIS. Development of Eimeria tenella was studied in primary cultures of chicken kidney cells maintained in Medium 199 lacking each of the following: vitamin A. biotin, p‐aminobenzoic acid, folic acid, nicotinamide, Ca pantothenate, pyridoxine, pyridoxal, riboflavin, thiamin, ascorbic acid, calciferol, α‐tocopherol, and menadione. Data obtained concerning numbers of mature schizonts or total numbers of parasites or both indicated that all of the vitamins are needed for 1st‐ and 2nd‐generation schizogony, and all except calciferol and folic acid are needed for gametogony.
Enzymes of the Ornithine‐Arginine Metabolism of Trypanosomatids of the Genus Herpetomonas*
Authors: YOSHIDA NOBUKO , JANKEVICIUS J. VITOR , ROITMAN ISAAC , CAMARGO E. PLESSMANN
Published: May 2007

SYNOPSIS. Five strains of trypanosomatids, Herpetomonas megaseliae, H. samuelpessoai, H. muscarum muscarum, H. muscarum ingenoplastis and a newly isolated Herpetomonas sp., were examined for the enzymes of arginine‐ornithine metabolism. Ornithine carbamoyltransferase (E.C. 2.1.3.3) and argininosuccinate lyase (E.C. 4.3.2.1) were detected in cell extracts of H. megaseliae, H. samuelpessoai and H. muscarum muscarum but not of others. Both enzymes seemed repressible by arginine, which could account for their apparent absence in H. muscarum ingenoplastis and Herpetomonas sp., which grow in a complex, arginine‐rich medium. Additionally, arginine deiminase (E.C. 3.5.3.6) and citrulline hydrolase were detected in cell extracts of the 5 strains examined. This latter enzyme, previously described only in Tetrahymena, effects the single‐step hydrolysis of citrulline into ammonia, ornithine and CO2. Arginase (E.C. 3.5.3.1) and urease (E.C. 3.5.1.5) were not found in any of the strains examined. Some of the physicochemical characteristics of the enzymes encountered are described.
Monocystid Gregarine Parasites of Nigerian Earthworms
Authors: SEGUN A. O.
Published: May 2007

SYNOPSIS Seven monocystid gregarine parasites including 6 new species are described from the perivisceral coelom and seminal vesicles of Nigerian earthworms, which have not been so far investigated for monocystid parasites. The new species are: Apolocystis iridodrilii sp. n. from Iridodrilus preussi and Iridodrilus roseus; Apolocystis libyodrilii sp. n., Monocystis abegbei sp. n., Monocystis libyodrilii sp. n., and Zygocystis violacea sp. n. from Libyodrilus violaceus; and Nematocystis bunmii sp. n. from Heliodrilus lagosensis. Apolocystis herculea (Bosanquet) was recorded from Libyodrilus violaceus.
Studies of Growth and Development of Gametocytes in Haemoproteus columbae Kruse*
Authors: AHMED FARID E. , MOHAMMED ABDEL‐HAFEZ H.
Published: May 2007

SYNOPSIS As determined by their ability to exflagellate and round up, it took the macrogametocyte and the microgametocyte of Haemoproteus columbae in pigeons 68 and 116 h, respectively, after patency to reach maturity. Pigment granules appeared in the undifferentiated gametocytes 8 h after invasion of blood. Vacuoles were observed in young gametocytes and persisted in the older forms. The growth curve of H. columbae is close to the sigmoidal curve for growth in protozoa. Multiple infection was noticed in pigeons with high levels of parasitemia, but no more than 2 gametocytes reached maturity; such multiple infections were rare in relapses. The sex ratio of the gametocytes was 1:1. Strong lateral displacement of the nuclei of infected erythrocytes was the rule; hypertrophy was negligible.
Relation Between Cell Union and Nuclear Reorganization in Triplet Conjugants of Paramecium caudatum and Paramecium multimicronucleatum
Authors: TAKAGI YOSHIOMI , HARUMOTO TERUE
Published: May 2007

SYNOPSIS Triplet conjugants of Paramecium caudatum which appeared naturally in mating mixtures and those of Paramecium multimicronucleatum which were produced by conjugation‐inducing chemicals were isolated. Triplet conjugants lasting for more than 3 h were stained to examine macronuclear events. In P. caudatum, only 2 triplets among 182 (1%) contained macronuclear fragmentation in all 3 members. The most frequently occurring triplets (79%) were those producing 1 cell without and 2 cells with macronuclear fragments. There were also triplets (17%) producing 1 cell with, and 2 without macronuclear fragments, and some (3%) with 3 cells that contained no fragments. The length of persistence of the triplet was not responsible for the occurrence of macronuclear fragmentation in the 3rd cell of the triplet. In P. multimicronucleatum, the same 4 classes of triplets occurred, but the most frequently occurring class was that consisting of 3 cells (91%) with macronuclear fragments. Induction of nearly 100% of triplets with 3 such cells was possible by isolating the triplets' from a culture which was treated chemically at about 24 h after the last feeding. Treatment with chemicals in starved cultures resulted in triplets with incompletely fragmented or nonfragmented macronuclei. Further, in P. multimicronucleatum, chemicallyinduced triplets involving only holdfast pairs to which the 3rd cells were uniting often produced 3 cells with fragmented macronuclei.
Ultrastructure of Endosymbiotic Chlorella in a Vorticella
Authors: GRAHAM LINDA E. , GRAHAM JAMES M.
Published: May 2007

SYNOPSIS Observations were made on the ultrastructure of a species of Vorticella containing endosymbiotic Chlorella. The Vorticella, which were collected from nature, bore conspicuous tubercles of irregular size and distribution on the pellicle. Each endosymbiotic algal cell was located in a separate vacuole and possessed a cell wall and cup‐shaped chloroplast with a large pyrenoid. The pyrenoid was bisected by thylakoids and surrounded by starch plates. No dividing or degenerating algal cells were observed.
Intestinal Disaccharidase and Peroxidase Deficiencies during Eimeria nieschulzi Infections in Rats*
Authors: DUSZYNSKI DONALD W. , ROY SHIRLEY A. , CASTRO GILBERT A.
Published: May 2007

SYNOPSIS Experiments were designed to study intestinal pathophysiologic changes associated with coccidial infections in mammalian hosts. Pairs of male Sprague‐Dawley rats were killed at various times postinoculation (PI) with 104 or 106 sporulated occysts of Eimeria nieschulzi. The small intestine from each rat was removed, weighed, measured, and divided into thirds. From the middle 11 cm of each third, one cm was fixed for histologic examination. Mucosa was scraped from the remaining 10 cm and was assayed for protein content and for peroxidase, sucrase and trehalase activities. Infection with E. nieschulzi was associated with increased mass of the small bowel. Histologically, crypt depth throughout the small bowel was significantly greater (P≤ 0.005) in infected rats than in non‐infected ones on PI days 8 and 16. Villus height did not change drastically during low‐dose infections (104 oocysts) and varied during high‐dose infections (106 oocysts). As a result of these morphologic changes in the mucosa, crypt/villus ratios were usually significantly greater (P≤ 0.005) in all infected rats throughout the small bowel. In general, increased gut weight and changes in crypt and villus dimensions became evident by PI day 2, were most pronounced at PI day 8, and began to return to control values by PI day 16. Peroxidase, sucrase, and trehalase levels equaled or were slightly higher than in controls on PI day 2, dropped significantly below controls (P≤ 0.05) by PI day 8, and returned to, or exceeded control levels by PI day 16. The intensity of all changes was directly dose‐dependent.
The Inverse Relationship Between Nutrient Nitrogen Concentration and Coccolith Calcification in Cultures of the Coccolithophorid Hymenomonas sp.*
Authors: BAUMANN F. GREGORY , ISENBERG HENRY D. , GENNARO JOSEPH
Published: May 2007

SYNOPSIS Chemical analysis of axenic cultures of Hymenomonas sp. reveals that the degree of coccolith calcification is inversely proportional to the concentration of available nitrogen sources in the medium. This relationship makes possible a useful degree of control over the organism's calcifying activities. In addition, a possible selective advantage of such a relationship in nature is suggested.
The Relationship of Fixed Carbon and Nitrogen Sources to the Greening Process in Euglena gracilis strain Z*
Authors: SCHWELITZ FAYE D. , CISNEROS PAULINE L. , JAGIELO JULIA A. , COMER JEFFREY L. , BUTTERFIED KEVIN A.
Published: May 2007

SYNOPSIS The pattern of chloroplast development was followed in Euglena gracilis strain Z greening in media with a variety of fixed carbon and nitrogen sources. The greening pattern of cells grown in inorganic medium with added ethanol or glucose involves an inhibition of chloroplast development when compared to that of cells grown in inorganic medium alone. Several nitrogen sources were tested to ascertain their effectiveness in relieving the inhibition of chloroplast development by glucose. Of those, only 0.05% (w/v) (NH4)2 SO4 accelerated the recovery from the inhibition after most of the glucose had been removed from the medium by the cells. The other nitrogen sources tested were not effective. An inhibition of chloroplast development, similar to that observed in cells greening in the presence of glucose, was seen in cells greening in an ethanol‐containing medium. These cells, however, had a different response upon the addition of 0.05% (NH4)2 SO4. They appeared to recover from the inhibition of chloroplast development, even before the ethanol was removed from the medium by the cells. A slight enhancement of chloroplast development was noted in cells greening in an inorganic medium with glycine or serine. Other amino acids tested had little or no effect.
Ciliary Membrane Proteins of Tetrahymena thermophila
Authors: BUTZEL HENRY M. , DECAPRIO ANTHONY
Published: May 2007

SYNOPSIS SDS polyacrylamide gels of the ciliary membrane proteins of Tetrahymena thermophila revealed 5 major peaks and 11 minor protein peaks ranging in molecular weight from below 20,000 to above 250,000. The peaks resembled those found for ciliary membrane proteins of Paramecium aurelia..
Influence of Sphingolipid Bases, Fatty Acids and Tween 80 on the Folate Requirement of Tetrahymena pyriformis*
Authors: DEWEY VIRGINIA C. , KIDDER GEORGE W.
Published: May 2007

SYNOPSIS The fatty acids lauric, myristic, and oleic, as well as long‐chain bases (LCBs) obtained from sphingolipids, and Tween 80 “spare” the requirement for folate by Tetrahymena pyriformis W. Since LCBs are metabolized by the ciliate to ethanolamine phosphate and fatty aldehydes which can be converted to either fatty acids or fatty alcohols, the latter compounds are used as precursors of phospho‐ and phosphonolipids and ether phospholipids. It is suggested that lipid biosynthesis is a rate‐limiting step in growth of the ciliate as is the folate concentration. Removal of one restraint on growth rate mimics the effect of increased folate concentration. Alternatively, if the enzymes responsible for lipid synthesis are repressible, the presence of exogenous fatty acids would make available more formylmethionyl‐tRNA for the initiation of synthesis of other proteins.
Effect of Acetate on Esterase C Activity During the Growth Cycle of Paramecium*
Authors: ALLEN SALLY LYMAN , NERAD THOMAS A.
Published: May 2007

SYNOPSIS Enhanced esterase C activity could be demonstrated by starch gel electrophoresis in various stocks of Paramecium spp. (P. primaurelia stocks 90 and 540, P. biaurelia stock 93, P. tetraurelia stock 29. P. pentaurelia stock 87, P. octaurelia stocks 31 and 300, and P. multimicronucleatum species 3, stock 8 MO) grown in Adaptation Medium. This esterase, however, was barely detectable when they were cultivated in Axenic Medium. Addition of trypticase to Adaptation Medium resulted in reduction of esterase C in the ciliates. This effect is ascribable to Na acetate present in trypticase. Since esterase C increased with the decrease in acetate concentration (as estimated by gas‐liquid chromatography) during growth of Paramecium, acetate appears to be utilized by the cells. Sensitivity of esterase C to acetate occurs in all 6 species of Paramecium examined. Different stocks within a species may have different levels of sensitivity; in one case this is genetically determined. The results emphasize the importance of controlling and manipulating growth conditions for the assessment of inter‐ and intraspecies variations in the isozymes of Paramecium.
Genetic Evidence Concerning the Structure of the Tetrahymena thermophila Macronucleus*†
Authors: NANNEY D. L. , PREPARATA R. M.
Published: May 2007

Synopsis.

A satisfactory model of the Tetrahymena thermophila macronucleus must explain its genetic behavior in terms of its constituent molecules. Particular genetic phenomena requiring explanation are (a) phenotypic assortment, here interpreted as resulting from allelic disjunction rather than from differential gene expression; (b) unequal allelic input for some loci, interpreted as a consequence of unequal and selective replication of some alleles during early macronuclear development; (c) delayed assortment at some loci, interpreted as an effect of inequality of allelic input combined with a generalized elevation of DNA content during early clonal history; (d) linkage disruption, probably reflecting continuous somatic recombination rather than dissolution of chromosomes into small repliconic units; (e) assortment depression, brought about by the occasional association of homologous replicons (chromosomes) or else by a differential increase in some classes of replicons; (f) ploidy‐related developmental differences in macronuclear primordia are interpreted on the basis of quantitative differences in DNA rather than in terms of an early perception of genic imbalance, (g) Ploidy independent macronuclear DNA content is consistent with several models of size regulation.
Eimeria malabaricas sp. n. and Eimeria bandipurensis from the South Indian Tree Squirrel, Funambulus tristriatus*
Authors: CHOWATTUKUNNEL JOSEPH T.
Published: May 2007

Synopsis.

Oocysts of Eimeria malabaricas sp. n. and Eimeria bandipurensis from the South Indian tree squirrel Funambulus tristriatus collected in Kerala, India, are described. Sporulated oocysts of E. malabaricas were ellipsoid to subspherical measuring 39.8 (35–45) × 32.1 (29–37) m̈m, with a thick (2.5–3.0 m̈m), 2‐layered wall. The outer layer was yellow‐brown, striated, and rough. There was no micropyle. but a polar granule was present in 34% of oocysts. The sporocysts were ovoid, 16.0 (14.0–18.0) × 11.2 (11.0–12.0) m̈m, with a Stieda body and a granular residuum. Excysted sporozoites were 21.8 (19.0–23.0) × 3.4 (3.0–4.0) m̈m, with a large refractile body.

The sporulated oocysts of E. bandipurensis are redescribed.
Correlation of Sugar Release and Concanavalin A Agglutinability with Infectivity of Symbiotic Algae from Paramecium bursaria for Aposymbiotic P. bursaria
Authors: WEIS DALE S.
Published: May 2007

Synopsis.

Eighteen strains of algae, including 17 formerly symbiotic with Paramecium bursaria, were tested for capacity to release sugar. Detectable amounts of sugar were found in the supernatant fluids from 10 strains, including 6 strains infective for aposymbiotic P. bursaria syngen 2. The other 4 sugar‐releasing strains were noninfective and released ˜26–46 m̈g sugar/mg dry cell weight compared to ˜90–175 m̈g sugar/mg dry cell weight for infective strains. This relationship of infectivity with capacity to release sugar supplements data that indicate a relationship of infectivity with resistance to Con A agglutination. The correlation is completed if we assume that resistance to Con A agglutination and capacity for sugar release must both be present in an algal strain for infectivity. The data thus strongly suggest that these 2 characteristics must be present for infectivity by any algal strains for aposymbiotic P. bursaria syngen 2.
Effects of Visible and Ultraviolet Light on Carotene‐deficient Mutants of Crypthecodinium cohnii
Authors: WITHERS NANCY W. , TUTTLE ROBERT C.
Published: May 2007

Synopsis.

The ability of carotenoids to protect a heterotrophic dinoflagellate, Crypthecodinium cohnii, from photodynamic damage by sunlight in the presence of an exogenous dye was demonstrated. Wild‐type C. cohnii and 2 carotcnoid‐deficient mutants were plated on agar‐solidified media and exposed to natural sunlight. The wild‐type strain, which synthesizes γ–carotene and β–carotene, had the lowest mortality. Mutant car 17 which accumulates mainly §–carotene had an intermediate mortality rate while the albino mutant, car 3, which contains only phytoene, lost viability most rapidly. Wild‐type cells treated with diphenylaminc, a carotenogenic inhibitor, were killed at the same rate as mutant car 3. The survival rate of mutants on exposure to sunlight was dependent upon the chromophore length of the accumulated carotenoids. The 3 strains showed no difference in rate of mortality when exposed to ultraviolet light. Protection from sunlight by accumulation of carotenes may be an important ecological factor for this species whose natural habitat is tidepools.
Observations on Gametogenesis in Plasmodium falciparum from Continuous Culture*
Authors: JENSEN JAMES B.
Published: May 2007

Synopsis.

Gametocytes of Plasmodium falciparum were produced in continuous cultures but eventually declined in numbers after 3–4 months in vitro. Their development progressed in a consistent pattern, from small rounded, through triangular, to ellipsoidal, and finally after 8 days to crescentic forms. Morphologic maturity occurred at 8–9 days, but the gametocytes would not exflagellate in vitro, even after 14–18 days of development. Thus, current culture methods cannot produce a continuous supply of functional gametes for further studies.