bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Saurian Malarial Parasite Plasmodium balli from Panama
Authors: TELFORD SAM R. 
Published: May 2007

SYNOPSIS. Plasmodium balli sp. nov. is described from Anolis lionotus and A. poecilopus of central Panama.Large, elongate gametocytes and segmenters containing up to 100 merozoites are produced by P. balli. Proerythrocytes and normoblasts are more commonly parasitized than erythrocytes. Pigment is uncommon, but when present consists of a minute dot. Hypertrophy, distortion and lysis of host cell nuclei may result from parasitization of immature blood cells by gametocytes, while enucleated host cells are common.
Mating Types in Stentor coeruleus
Authors: WEBB TERRY L. , FRANCIS DAVID 
Published: May 2007

SYNOPSIS. Conjugation in Stentor coeruleus was investigated, using a standardized culture technic which yielded large numbers of mating pairs within a single culture. Spontaneous bursts of selfing occurred during a definite interval in the development of a culture. Structurally distinct preconjugator cells appeared immediately before as well as during the initial stages of a burst of conjugation. Mating pairs were formed by the union of 2 preconjugators.Mixing 8 stocks in all possible combinations of pairs and observing their subsequent response revealed they were separable into 2 complementary mating types. The majority of mating pairs formed in mixtures of stocks consisted of individuals of different mating types.It is suggested that control of mating types in the ciliate order Heterotrichida may be of a somewhat different nature from that found in other ciliates.
Amoeboflagellate Transformations and the Gibbs‐Donnan Ratio*
Authors: PERKINS DONALD L. , JAHN THEODORE L. 
Published: May 2007

SYNOPSIS. A number of protozoa may have amoeboid, flagellated, or intergrade forms. At the present time several mechanisms have been proposed for inducing the formation of each of the above forms, but a definite triggering mechanism has not been elucidated. However, some change in the environment precedes the transformation of the cell from one form to another.Jahn (1962) and Czarska (1964), respectively, correlated ciliary reversal and water expulsion vesicle activity with alterations in the ionic environment. In both cases the processes involved are correlated with changes in the Gibbs‐Donnan (G‐D) relationship rather than direct ratios or molarities. It seems reasonable to assume that additional environmentally induced phenomena may also be based on changes in the relationship.The assumption is here made that an amoeboid cell, possessing the necessary genetic and physiologic potentials, can respond to certain changes in its environment by enflagellation.The following hypothesis is being considered: a change in the environment that increases the relative concentration of associated divalent cations is perhaps one of the main triggers for amoeba‐to‐flagellate transformations. Thus, in accordance with the G‐D theory, this transformation would be expected to occur when a given ionic environment is diluted. In addition, the transformation is discussed in relation to pH, population density, and other environmental parameters that alter the Gibbs‐Donnan ratio.
The Polyunsaturated Fatty Acids of Marine Dinoflagellates
Authors: HARRINGTON GLENN W. , BEACH DAVID H. , DUNHAM JOYCE E. , HOLZ GEORGE G. 
Published: May 2007

SYNOPSIS. Eight photosynthetic and one heterotrophic, marine dinoflagellates were cultured axenically in chemically defined media and their fatty acids characterized. Palmitic, octadecatetraenoic and docosahexaenoic were the most typical fatty acids. Photosynthetic forms also contained the polyunsaturates icosapentaenoic acid and α‐linolenic acid, the latter as a relatively minor component. The galactolipids of one photosynthetic species, Glenodinium sp., were isolated and their fatty acids analyzed. Octadecatetraenoic acid was the predominant fatty acid, particularly of the monogalactosyl diglyceride fraction.The relationship of these findings to the body of knowledge of the photosynthesis‐associated lipids of eucaryotic microbes and to the ecology of polyunsaturated fatty acids in marine food chains is discussed.
Oxaloacetate Production via Carboxylations in Crithidia fasciculata Preparations
Authors: BACCHI CYRUS J. , CIACCIO E. I. , KABACK DAVID B. , HUTNER S. H. 
Published: May 2007

SYNOPSIS. Fractions containing soluble enzymes from Crithidia fasciculata had an ADP‐linked phosphoenolpyruvate (PEP) carboxykinase. The enzyme produced ATP and oxaloacetate (OAA) from PEP, ADP and HCO−3. OAA was determined as the endproduct of reactions by forming the 2,4‐dinitrophenylhydrazone derivative; the hydrazone was identified by thin‐layer chromatography. Approximate Michaelis constants (PEP, Mg, HCO−3, ADP) were determined spectrophotometrically by linking OAA production to malic dehydrogenase. The PEP carboxykinase did not utilize GDP, UDP or IDP as cofactors; the metal requirement was also satisfied by Mn. The enzyme was inhibited by the biotin antagonists avidin and desthiobiotin.A pyruvate carboxylase was also present in the preparations, generating OAA from pyruvate and ATP. The role of both enzymes in OAA production and subsequent production of succinate is discussed with regard to C. fasciculata and other trypanosomatids.
Life Cycle of Autogamous Strains of Euplotes minuta*
Authors: LUPORINI PIERANGELO 
Published: May 2007

SYNOPSIS. The life cycles of 5 autogamous strains of Euplotes minuta are reported. Interautogamic intervals (measured as number of fissions) are quite variable among clones belonging to the same strain, while their variability is much reduced (15 fissions) among sublines of the same clone.By selecting the clone with the shortest immature period to start successive autogamous generations, it has been found that all clones undergo autogamy almost synchronously and have a very short period of immaturity at the 5th autogamous generation.Both conjugation and autogamy, however, are consistently followed by immature periods in all autogamous strains examined. Mating capacity as well as competence for autogamy are reached almost simultaneously in all clones of the strains studied with the exception of about 1/3 of the A‐31 clones in which autogamy occurs significantly earlier than conjugation.The results are discussed from the genetic point of view and in relation to the sexual mechanisms operating in nature within different populations of the species.
Early Stages in the Differentiation of Gametocytes of Haemoproteus columbae Kruse*
Authors: BRADBURY PHYLLIS CLARKE , ROBERTS JOHN F. 
Published: May 2007

SYNOPSIS The sexes of mature gametocytes of Haemoproteus columbae Kruse circulating in the blood of the domestic pigeon can be identified in the electron microscope by the same criteria that distinguish them in the light microscope. The microgametocyte has a large nucleus and pigment granules restricted to the 2 extremities of its halter‐shaped cells. The macrogametocyte has dense granular cytoplasm with scattered pigment granules and a small central nucleus. The sex of young gametocytes cannot yet be recognized.When blood containing mature gametocytes is cooled outside the body of the host visible signs of gametogenesis appear within 30 seconds. The earliest signs are increasing electron lucidity of the cytoplasm and separation of the outer membrane from the body of the parasite. The membrane may form vesicles or whorls or lie free in the erythrocyte's cytoplasm. The middle membrane of the parasite becomes the plasma membrane. Axonemes and microtubules appear in the cytoplasm and nucleoplasm of the microgametocyte. The macrogametocyte lags slightly behind the microgametocyte in development. With the first signs of differentiation, the host cell cytoplasm begins to disappear. The fate of the outer membrane and the erythrocyte's cytoplasm suggests the release of a lytic substance by the parasite.
The Influence of Hyaluronidase and Hyaluronidase Substrates on Penetration of Cultured Cells by Eimerian Sporozoites
Authors: FAYER RONALD , ROMANOWSKI ROBERT D. , VETTERLING JOHN M. 
Published: May 2007

SYNOPSIS Leighton tube cultures of bovine embryonic kidney cells were inoculated with Eimeria adenoeides sporozoites suspended in media containing either hyaluronidase, hyaluronidase substrates (chondroitin sulfate and hyaluronic acid) or Ficoll. After 1 hr at 41 C, coverslips were removed and cells were fixed and stained. Hyaluronidase (1 and 10 mg/ml) did not increase the number of intracellular sporozoites. Chondroitin sulfate (1 and 10 mg/ml) and hyaluronic acid (1 mg/ml) did not reduce the number of intracellular sporozoites. However, the number was reduced when the media contained either chondroitin sulfate (100 mg/ml) or hyaluronic acid (5 mg/ml), which were quite viscous.Ficoll (117 mg/ml), which produced the same viscosity as 5 mg hyaluronic acid/ml, also reduced the number of intracellular sporozoites. This finding circumstantially indicates that sporozoites may be physically inhibited from entering cells by the high viscosity of the substrates.Biochemical tests, which detected as little as 0.2 μg of known hyaluronidase, failed to detect hyaluronidase activity in excysted intact or fragmented E. adenoeides sporozoites or in sporozoites within E. tenella oocysts.
A Microsporidan Infection of Anopheles gambiae Giles, from Tanzania, Interpretation of Its Mode of Transmission and Notes on Nosema Infections in Mosquitoes
Authors: CANNING ELIZABETH U. , HULLS RICHARD H. 
Published: May 2007

SYNOPSIS A microsporidan found parasitic in Anopheles gambiae in Tanzania was identified as Nosema algerae Vavra & Undeen, 1970. Its development was traced in laboratory‐bred Anopheles stephensi. Spores were oval, 3.0‐4.3 μ× 1.8‐2.5 μ and had filaments 40‐60 μ long; schizonts were uni‐, bi‐ or tetranucleate; elongate sporonts gave rise to 2 sporoblasts. The parasite attacked almost every tissue of the body of the larvae, pupae and adults including the ova, but transovarial transmission was thought to be unimportant as infected ova did not develop into viable larvae. Hosts reacted to the presence of the parasite by encapsulating some spores in a coat of melanin.The parasite was lightly infective to several species of culicine mosquitoes, but the infection was limited mainly to the nervous system, mid‐gut epithelium and Malpighian tubules.The species of Nosema parasitizing mosquitoes are reviewed.
Suggestive Structural Evidence for Macronuclear “Subnuclei” in Tetrahymena pyriformis GL
Authors: NILSSON JYTTE R. 
Published: May 2007

SYNOPSIS Structural changes in the Feulgen‐positive material of the Tetrahymena pyriformis GL macronucleus have been observed during the cell cycle. From the finely granulated appearance in the interphase cell it appears as small rods, often arranged in pairs (probably the endomitotic stage) during early morphogenesis and as larger (and fewer) aggregates of granules during the nuclear division. These latter aggregates are also visible in dividing nuclei in the electron microscope where groups of chromation granules are separated by fairly empty nucleoplasm. It is suggested that these Feulgen positive aggregates in dividing nuclei are macronuciear segregation units or “subnuclei.” The number per dividing macronucleus may vary from one experiment to another, but the variation seems to be related to cell volume. The distribution of the aggregates among the daughter nuclei is almost equal. The total number per dividing macronucleus is about 80 which is close to the estimated number of “subnuclei” in the T. pyriformis macronucleus (Allen and Nanney, 1958).Some calculations are made on the polyploidy of the T. pyriformis GL macronucleus. Using published electron micrographs of micronuclei of known age to calculate the total number of chromatin granules per haploid nucleus, the polyploidy of the strain GL macronucleus is about 40. This figure is half of that expected from Allen and Nanney's estimation, since they assumed that the “subnuclei” were diploid; however, it is in agreement with the reported haploid nature of the “subnuclei” as found by Woodard, Gorovsky & Kaneshiro, 1968. Further calculations suggest that each macronuclear “chromosome” is composed of about 40 chromatin granules; an indication of such a chain arrangement of the chromatin granules has been observed in the phase contrast and electron microscope during the earliest macronuclear events, i.e., at the macronuclear “prophase.“
Saurian Malarial Parasites in Eastern Panama
Authors: TELFORD SAM R. 
Published: May 2007

SYNOPSIS Plasmodium gonatodi sp. nov. is described from Gonatodes albogularis fuscus of eastern Panama. It is characterized by elongate gametocytes and polymorphic schizonts containing 12‐46 nuclei when apparently mature. Both proerythrocytes and erythrocytes are commonly parasitized, host cells are hypertrophied and distorted, and their nuclei are displaced. Prematuration sexual stages may be irregularly shaped and larger than mature gametocytes.Plasmodium diploglossi Aragão and Neiva, 1909 is reported from Mabuya mabouya in eastern Panama, and Plasmodium morulum sp. nov. is described from this host. P. morulum usually parasitizes immature erythrocytes, and is characterized by lenticular or oval to round gametocytes, and schizonts with 14‐40 nuclei usually arranged in a globular mass. Host cells are slightly hypertrophied and distorted, and their nuclei are usually displaced. Inoculation of infected blood into clean hosts produces numerous schizonts in white cells as well as in the erythrocyte series.Pigment in both P. gonatodi and P. morulum, if present, consists of a few minute dark dots which do not meet the polarized light test for hemozoin.
Purine and Pyrimidine 5′‐Nucleotide Catabolism in Tetrahymena pyriformis W1
Authors: CONNER ROBERT L. , LINDEN CAROL 
Published: May 2007

SYNOPSIS Deamination at pH 7.5 of adenosine, deoxyadenosine, cytidine and deoxycytidine by cell‐free preparations of Tetrahymena pyriformis W was observed both in the presence and absence of fluoride. Deamination of 5′‐AMP, 5′‐dAMP, 5′‐CMP, and 5′‐dCMP was found only in the absence of fluoride. Dephosphorylation of the above nucleotides by acid phosphatases occurred at pH 4.5; reduced activity was noted at pH 7.5. Fluoride effectively blocked acid phosphatase activity at both pH values. This correlation of phosphatase and deaminase activities suggests a catabolic pathway for 5′‐AMP and 5′‐CMP whereby dephosphorylation precedes deamination. Radiolabelled substrates were used to test this hypothesis. The experiments were designed so that conversion of as little at 1.0% of the radiolabelled substrate to the deaminated product could be detected. No 5′‐IMP or 5′‐UMP, the expected deamination products of 5′‐AMP and 5′‐CMP, respectively, was recovered after incubation of the radiolabelled substrates with cell‐free enzyme preparations. Thus, it appears that Tetrahymena has no 5′‐AMP or 5′‐CMP deaminases and that these compounds are deaminated only after conversion to nucleosides.Acid phosphatase activity toward 5′‐GMP, 5′‐dGMP, 5′‐TMP, 5′‐UMP, and 5′‐XMP was also found.
The Ultrastructure of Polytomella agilis*
Authors: MOORE JOSEPH , CANTOR MARVIN H. , SHEELER PHILLIP , KAHN WAYNE 
Published: May 2007

SYNOPSIS Motile cells and cysts of Polytomella agilis, obtained over the entire growth cycle, were examined by electron microscopy. In typical late log phase cells there is a concentric arrangement of the internal organelles around the centrally located nucleus. Lying just beneath the plasma membrane is a peripheral band of elongate mitochondria. Numerous well defined Golgi bodies are also distributed around the nucleus. Vesicles associated with the Golgi body increase in size with distance from the secretory edges of the organelle. Cytoplasmic membranes with associated ribosomes are found between the mitochondrial and Golgi regions. A layer of slender membrane‐limited structures is located near the mitochondrial layer. These organelles, which resemble proplastids, become highly branched during late log and early stationary phase, reaching maximum development in late stationary and early pre‐cyst stages.Large storage granules of varying density are found within the cell. The PAS‐positive granules have been isolated and shown to contain starch. There is an increase in the amount of this storage material as the cells enter the stationary phase.The remainder of the cytoplasmic matrix is finely granular and contains numerous free ribosomes except in the region of the anterior papilla. Four flagella arise from basal bodies at the anterior end of the cell.The cyst is characterized by a thick multi‐layered cell wall whose electron density obscures the limiting plasma membrane. Large storage granules are located close to and often in contact with the periphery of the cell, suggesting their involvement in the process of cell wall deposition.Altho mitochondria can still be seen in the mature cyst, other cytoplasmic organelles often appear atypical. The mature cyst has an irregular profile possibly due to shrinkage from dehydration.
Induction of Synchronized Fissions in Telotrochidium henneguyi
Authors: McLAUGHLIN DAVID , BARNES DONALD T. , FINLEY HAROLD E. 
Published: May 2007

SYNOPSIS. Cultures of Telotrochidium henneguyi, begun with logarithmic phase cells, were employed in an effort to produce synchronized fission by heat treatment. The cells tolerated a temperature range of 20–50 C; temperatures above 50 were lethal. When cells were exposed to a single shock for 30 min, 30–40 produced 0–50% encystment with total excystment after 10 min exposure to room temperature (heat shock range). No encystment occurred between 20–30 (intershock range). Encystment and excystment time varied directly with temperature between 40–50.The most effective procedure for inducing synchronized fission consisted of 6 cycle program of 38/28 C (shock temperature/intershock temperature) administered for 15/15 (shock/intershock duration in min). Division indices (DI = cells dividing/total population X 100 =%) ranged from 12–66% with a mean of 37.25%. In control cells, division indices ranged from 2–20% with an average of 12%. Inferences from these independently derived findings are discussed.
Distribution of Acid Phosphatase in Paramecium caudatum: Its Relations with the Process of Digestion
Authors: ESTEVE JEAN‐CLAUDE 
Published: May 2007

SYNOPSIS. The distribution of acid phosphatase was investigated at the ultrastructural level in Paramecium caudatum. Acid phosphatase occurs in endoplasmic reticulum, Golgi apparatus, food vacuoles, autophagic vesicles, vacuolar and dense bodies. Some slight deposits are also seen in the mitochondria.These observations point out that this hydrolase activity is related to digestive processes. The enzyme, originating from the endoplasmic reticulum and Golgi apparatus reaches the food vacuole or autophagic vesicle likely via the reticulum. The digestion of the bacteria or of the enclosed organelle gives rise to electronopaque material which is later found in dense bodies. These dense bodies are likely secondary lysosomes and it is possible that they may fuse with the young food vacuole or with autophagic vesicles.
Cellular Aspects of the Resistance of Chickens to Eimeria tenella Infections*
Authors: HUFF DENNIS , CLARK DAVID T. 
Published: May 2007

SYNOPSIS. Sporozoites of Eimeria tenella were injected into the peritoneal cavity of normal chickens and chickens immunized against E. tenella. In some experiments normal scrum and serum from resistant chickens were injected prior to the injection of sporozoites. After 15 or 30 minute periods of intraperitoneal incubation, exudates were harvested and the occurrence of intracellular sporozoites was determined.Only macrophages and degranulated granulocytes were observed to contain sporozoites. There was no significant difference between the number of macrophages obtained from normal chickens (normal macrophages) which contained sporozoites and the number of macrophages obtained from immune chickens (immune macrophages) which contained sporozoites. Significantly fewer immune macrophages treated with immune serum contained sporozoites than untreated normal or immune cells, normal macrophages treated with either serum, or immune macrophages treated with normal scrum.Sporozoites in untreated normal macrophages did not appear to be harmed by the intracellular environment, based on structural observations. The majority of sporozoites in macrophages from all other groups were difficult to distinguish within the cytoplasm and were visibly distorted.It is hypothesized that the presence of fewer infected macrophages in exudates of immune chickens and serum‐treated normal chickens was caused by an enhanced ability of these cells to destroy the parasite.Similar observations were noted in the case of sporozoites within degranulated granulocytes of experimental groups. The lack of understanding of the degranulation phenomenon makes it difficult to interpret these findings.
Pellicular Microtubules in the Family Trypanosomatidae*
Authors: ANGELOPOULOS E. 
Published: May 2007

SYNOPSIS. Flagellates of 7 species from 5 genera of the family Trypanosomatidae were prepared for electron microscopy using a combination of surface tension spreading on a simplified Langmuir trough followed by critical point drying. These technics opened the cells and showed the microtubular complex in its 3‐dimensional configuration or in a flat sheet with the inside surface facing‐up.Tears originated near the flagellar end and proceeded in a posterior direction usually paralleling the tubules. Major differences in the spreading pattern were species‐specific. A connection between the flagellum and microtubules was not shown but strongly indicated by their constant association in all degrees of spreading. Most microtubules follow a spiral course from the flagellar end toward the posterior apical area and terminate short of the apex. It is suggested that the concept of antero‐posterior orientation in the genus Trypanosoma be reconsidered.Cells of Leptomonas collosoma showed, without exception, a clockwise spiral as the tubules approached the posterior apex. Therefore, both the direction of spiraling and the manner of spreading were consistent.The number of microtubules varied among cells of the same species as well as on different levels of the same cell. Highest counts coincided with the level of greatest circumference. No connections or anastomoses between tubules were found. The microtubules are believed to have limited flexibility. Changes in diameter were interpreted to mean flattening had occurred. An intertubular substance, believed to surround the microtubules in the living cell, was present in all species.
The Effect of Homologous Rabbit Antiserum on the Growth of Leishmania tarentolae—a Fine Structure Study
Authors: STRAUSS PHYLLIS R. 
Published: May 2007

SYNOPSIS. The fine structure of Leishmania tarentolae growing in the presence of homologous rabbit antiserum was investigated. Immediately after agglutination of the promastigotes, a dense band between pellicles of adjacent cells could be seen, and a surface coat was rendered visible. The cells did not fuse. At dilutions of antiserum from 1:100–1:1200 the promastigotes continued to grow, forming large masses. By 5 days these consisted of individual cells adhering to one another. In cross‐section, any 2 cells were separated by 2 membranes with associated subpellicular fibrils and a dense band between the 2 membranes.The term syncytium generally refers to a multinucleate cell originating by fusion of several cells and has been used to mean a multinucleate cell arising from nuclear division unaccompanied by cytokinesis. Therefore, it is unlikely that the masses formed in the presence of homologous antiserum are syncytia.