bluuebunny/crossref_metadata_2025 huggingface dataset:
Chlorophyll Formation in Euglena gracilis var. bacillaris: Effect of Chelating Agents
Authors: DUBASH P. J. , REGE D. V.
Published: May 2007

SYNOPSIS. 8‐Hydroxyquinoline (8‐HQ) and cysteine markedly inhibit the synthesis of chlorophylls in non‐proliferating etiolated Euglena gracilis var. bacillaris on illumination. This is thought to be due, at least to some extent, to the binding of Mg2+ ions in the non‐proliferation medium, but largely as a consequence of intracellular chelating action. The effect of 8‐HQ could be reversed by the presence of metal ions higher in the Mellor‐Malley series than Mg2+, e.g., Zn2+ and Co2+. Sodium diethyldithiocarbamate (Na‐DDG) and ethylenediaminetetraacetic acid (EDTA) have no effect on chlorophyll synthesis in non‐proliferation conditions. Growth in the light is more affected than growth in the dark by all these chelating agents, including Na‐DDG and EDTA. This is due to the differential requirement of Mg2+ under these 2 growth conditions.
Occurrence of the Myxosporidan Parasite Myxidium minteri in Salmonid Fish1
Authors: SANDERS J. E. , FRYER J. L.
Published: May 2007

SYNOPSIS. The myxosporidan Myxidium minteri was found in 3 recognized hosts, chinook and coho salmon and rainbow trout and 2 new hosts, cutthroat trout and mountain whitefish. Spores in all species examined were found primarily in the gall bladder. Fish infected with this parasite were obtained from both Oregon coastal rivers and Columbia River basin locations. In general the prevalence of infection was higher in the fish in coastal rivers.
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.
Studies of Messenger RNA during the Cell Cycle in Synchronized Mass Cultures of Tetrahymena pyriformis GL by Hybridization
Authors: CHRISTENSSON ERIK G.
Published: May 2007

SYNOPSIS RNA isolated from free ribosomes, from cell structures and from soluble cell phase after indole lysis of synchronized Tetrahymena cells showed different abilities to hybridize with DNA. The supraoptimal temperature (34 C) caused a decrease in the ability to hybridize in all 3 RNA fractions. The same effect was noted at the time of cell division. Synthesized messenger RNA as a proportion of the total quantity of RNA was roughly constant during the whole cell cycle. However, in contrast to synchronized mammalian cells the messenger RNA synthesis did not proceed at a constant rate thruout the cell cycle.
Eimeria ahtanumensis n. sp. from the Northwestern Fence Lizard Sceloporus occidentalis in Central Washington
Authors: CLARK GLEN W.
Published: May 2007

SYNOPSIS Eimeria ahtanumensis n. sp. is described from the northwestern fence lizard Sceloporus occidentalis. The sporulated oocysts are generally cylindrical with rounded ends, averaging 34.2 by 19.7 μ. No oocyst residuum or micropyle is present. The ellipsoidal sporocysts average 10.5 by 8.8 μ; each has a distinct sporocyst residuum composed of spherical granules located against the sides of the sporocysts. The elongate sporozoites, lying head to tail in the sporocyst, average 16.5 by 2.5 μ when excysted. Endogenous development occurs in the epithelial lining of the gall bladder and bile duct. E. ahtanumensis is compared to other similar lizard coccidia.
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.“
Factors Affecting the Rate of Photophosphorylation by Isolated Chloroplasts of Euglena gracilis*
Authors: CHANG IRENE C. , KAHN J. S.
Published: May 2007

SYNOPSIS The rate of photophosphorylation by Euglena chloroplasts depends not only on the physiologic stage of cell growth but also on the stage of development of chloroplasts in these cells at the time of harvesting. Both of these processes can be markedly influenced by a number of environmental factors; they are affected neither in a parallel manner nor completely independent of each other. In addition, the rate of photophosphorylation of chloroplasts can also be greatly affected by the conditions employed for their isolation. After investigating the various environmental factors both during cell growth and chloroplast isolation, we have developed a procedure which increased the photophosphorylation rate of our chloroplast preparations more than 5‐fold, giving a specific activity in the range of 100‐150 μmoles ATP/mg chlorophyll/hr routinely. The procedure is simple, needs no special equipment and requires only 2 or 3 days for cell growth.
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.
Polypeptide Synthesis with Microsomes from Pressure‐Treated Tetrahymena1
Authors: LETTS PAMELA J. , ZIMMERMAN ARTHUR M.
Published: May 2007

SYNOPSIS High hydrostatic pressure is known to interfere with mitosis, cytokinesis and synthesis of DNA, RNA and protein. In Tetrahymena, incorporation of phenylalanine and formation of polysomes are known to be pressure‐sensitive. Microsomal preparations from Tetrahymena pyriformis GL can incorporate [14C]‐phenylalanine into polypeptides. Incorporation was enhanced by addition of supernatant fraction and 14.5 mM Mg++ An energy‐generating system and exogenous messenger (poly U) were essential for polypeptide biosynthesis, Microsomes from pressurized cells (14,000 psi for 5 min) incorporated [14C]phenylalanine as efficiently as control microsomes. Microsomal function was not grossly damaged by pressure in a test system containing exogenous messenger, crude microsomal preparation, exogenous energy‐generating system and supernatant fraction containing activating enzymes.
Sporogony of the Oocysts of Isospora felis Wenyon, 1923 from the Cat*
Authors: SHAH HARISH L.
Published: May 2007

SYNOPSIS Sporogony of oocysts of Isospora felis from the cat was studied by observing the individual oocysts. Unsporulated oocysts were passed with the fresh feces. The sporont divided into 2 ball‐like sporoblasts which elongated and changed into sporocysts each of which 4 sporozoites then formed. All of the sporulating oocysts completed sporulation at 20 C in 40 hr, at 25 C in 24 hr, at 30 C in 12 hr, and at 38 C in 8 hr. The percentages of oocysts which sporulated at 20, 25, 30 and 38 C were 96, 95, 95 and 95 respectively. No sporulation occurred at 45 C and 50 C when oocysts were incubated for 4 hr. These oocysts evidently died because, on reincubation at 30 C for 4 hr, they failed to develop.
Changes in Ion Content in Heat‐Treated Tetrahymena Cells
Authors: HOLM B. J.
Published: May 2007

SYNOPSIS Changes in the amounts of Na+, K+, Mg2+ and Ca2+ were determined in the supernates of homogenized samples of Tetrahymena cells which were exposed to 7 heat shocks. The amounts of the same ions were also determined in the pH 4.5‐soluble fractions after dialysis. During the last shock, i.e., 6.5 hr after the start of heat treatment, there was a change in the ion balance characterized by a gain in Na+, Ca2+ and non‐dialyzable Mg2+ and a loss of K+. The change was not in phase with the synchronous cell division.
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.
Ciliate Ultrastructure: Some Problems in Cell Biology*
Authors: PITELKA DOROTHY R.
Published: May 2007

SYNOPSIS. Protozoology, along with other cell sciences, has profited immeasurably during the last 25 years from the application of electron microscopy and other new technics to studies of cell structure and function. Protozoa were among the first objects examined with the electron microscope in the 1940's and an extensive literature in protozoan ultrastructure has accumulated since then. Some examples of recent investigations of ciliate cortical ultrastructure are selected to illustrate the importance of protozoan studies to the development of fundamental concepts of cell biology. Ciliates are choice subjects for analysis of ciliary structure and motility and of myoneme contractility. Membrane‐limited alveoli contribute to the structure of the characteristic ciliate pellicle and provide evidence of how multiple pellicular membranes may affect cell‐surface activities. The striated fibrils and microtubules associated with ciliate kinetosomes resemble those of other cell types but are more highly organized; wherever they occur, these structures appear to be related to the development and maintenance of polarity and asymmetry of cells and organelles. Their stability and the precision of their arrangement in ciliates make them peculiarly suitable for the study of the properties and behavior of such fibrous organelles and also for investigation of the morphogenetic role of the kinetosome.
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 Numbers and Proportions of Testacea and Ciliates in Litters and Soils
Authors: BAMFORTH STUART S.
Published: May 2007

SYNOPSIS. The numbers and kinds of testacea and ciliates were studied in the litters and soils of 23 sites, from temperate and subtropical coniferous and deciduous forests, and grasslands. In coniferous forests, testacea were 10 times or more abundant than ciliates, and numbered 10,000–24,000/g (wet weight) in litters and up to 8,000/g in soils. Ciliates numbered up to 1,500/g, but averaged less than 600/g in litters and less than 300/g in soils. Under deciduous vegetation, ciliates approached, equaled, or exceeded testacea, and numbered 1,000–5,000/g in litters, while remaining about the same in soils. Temperature and soil influence vegetation types, and their rates of litter decay affect the protozoa. Moisture favors numerical dominance of certain species. Among testacea, several species dominate in a particular habitat; among ciliates, the genus Colpoda dominates in almost all litter and soil habitats.
Cytochemical Analysis of Enzyme Activity during Regeneration in Blepharisma intermedium Bhandary
Authors: PARKER JOHN W. , GIESE ARTHUR C.
Published: May 2007

SYNOPSIS. Transection and repair in Blepharisma intermedium modify the distribution of several enzymes. The number of active phagosomes is reduced and there are increased staining reactions for acid phosphatase, the nucleases and type‐B esterases in the ground cytoplasm. 5'‐Nucleotidase activity is localized in the cytoplasmic matrix. Except for ribonuclease, the enzymes may have a perimacronuclear deposition at some period during regeneration. Acid phosphatase may be involved in development of the oral membranelles. Adenosine triphosphatase and lactic dehydrogenase have a moderate staining intensity whereas malic and succinic dehydrogenases have a strong reaction in the cytoplasm; in addition, these enzymes may be localized in the kinetics involved in the neoformation of the oral concrescence. Nuclear reorganization is attended by an increased frequency of peripheral dehydrogenase activity in the late stages of regeneration. These observations are compared with catalytic systems known to function in protozoan metabolism and in vertebrate regeneration.
Changes in the Activity of Certain Enzymes of Hartmannella (Culbertson strain A‐1) During Encystment*
Authors: RAIZADA M. K. , MURTI C. R. KRISHNA
Published: May 2007

SYNOPSIS. Hartmannella (Culbertson strain A‐1) was found to undergo encystment (80–90% in 72 hr) on a non‐nutrient agar containing 0.015 M MgCl2 and 0.02 M taurine. Encystment was completely inhibited by 1 × 10−5 M Mitomycin C, or 1 × 10−7 M cycloheximide or 1 × 10−6 M Actinomycin D. The ability of the amoebae to consume glucose increased fourfold within 24 hr incubation in this medium. The specific activities of cellulose synthetase, hexosephosphate transaminase and uridine diphosphosphoglucose pyrophosphorylase were also stimulated. Dehydrogenases mediating electron transfer from pyruvate, malate, succinate, α‐ketoglutarate and α‐glycerophosphate to triphenyltetrazolium and from glucose‐6‐phosphate to nicotinamide‐adenine dinucleotide phosphate were, however, repressed during this period of incubation in the encystment medium. The results suggested that, during encystment of Hartmannella A‐1, there was a metabolic switchover and the enzyme machinery of the amoeba was oriented more towards biosynthesis of cyst wall constituents than towards the aerobic breakdown of carbohydrates.
Responses of Chlamydomonas reinhardi to Specific Nutritional Limitation in Continuous Culture*†
Authors: HUDOCK G. A. , GRING D. M. , BART C.
Published: May 2007

SYNOPSIS. Responses of wild type and mutant strains of Chlamydomonas reinhardi were studied in a simple but stable chemostat. No chlorosis was observed under conditions of phosphate, arginine or Na acetate limitation. Competition between wild type and the mutant strain y‐2 was studied in continuous culture with phosphate as the limiting nutrient in continuous light, continuous dark and alternating periods of light and darkness. In all cases, the mutant strain y‐2 overgrew the wild type.
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.
Cortical Patterns in Two Syngens of Glaucoma*
Authors: CHO PAULA LEE
Published: May 2007

SYNOPSIS. Strains of 2 syngens of Glaucoma (16) were found to have different cortical characteristics. All clones of a particular strain had approximately the same range of corticotypes, approximately the same means and high and very similar variances. The chief differences between the syngens was the corticotypic range. The patterns of variation of cortical elements of syngen 2 appeared to be primarily extensions of the patterns of syngen 1. The range of meridian numbers of different species of Glaucoma overlapped with each other and could not be distinguished by this criterion alone.
Evidence for a Link Between Division and Differentiation in Entamoeba invadens
Authors: MYER DONNA F. , MORGAN RICHARD S.
Published: May 2007

SYNOPSIS. Growth curves in a monophasic, polyxenic medium are presented for a strain of Entamoeba invadens. Three characteristics of these curves are: 1) the increase in numbers of trophozoites is linear with time; 2) the increase in numbers of cysts is linear with time; and 3) the durations of these 2 periods are equal to each other. Additional experiments are described in which variations of the culture conditions do not alter these 3 characteristics. Because of these data, we propose that, under the cultural conditions we have used, division of the trophozoites of Entamoeba invadens is coupled to the differentiation of these cells into cysts.
A Malaria Parasite, Plasmodium aurulentum sp. nov. from the Neotropical Forest Gecko Thecadactylus rapicaudus
Authors: TELFORD SAM R.
Published: May 2007

SYNOPSIS. Plasmodium aurulentum sp. nov. from the neotropical forest gecko Thecadactylus rapicaudus in Panama is characterized by oval or round to lenticular gametocytes, 6–22 nuclei in crudely fan‐shaped schizonts, and light golden pigment masses. A prominent, pinkish red‐staining mass, present in older schizonts, disappears by the time schizonts reach maturation.
The In Vitro Growth Response of Giardia Trophozoites from the Rabbit*
Authors: DANCIGER MICHAEL , MEYER ERNEST A.
Published: May 2007

SYNOPSIS. A visual technic has been developed for determining concentration of Giardia trophozoites in culture tubes. Such a technic is desirable because the nature of Giardia growth makes routine enumeration of these organisms by hemocytometer or electronic cell counter expensive in both time and material. The visual method of counting Giardia trophozoites was correlated with counts of the same suspensions of organisms using an electronic particle counter.

As a part of the correlation, the growth response, as measured by electronic cell counter, was established for 8 primary axenic cultures of Giardia trophozoites from the rabbit. The average starting number of organisms was 3.7 ± 0.6 × 103 per ml, the average number of organisms at the peak of logarithmic growth was 1.78 ± 0.2 × 105 per ml, and the generation time was 18.1 ± 1.6 hr. These data are compared with the available literature data quantitating Giardia growth.
Acephaline Gregarines of Earthworms—Additions to the British Records
Authors: SEGUN A. O.
Published: May 2007

SYNOPSIS. 30 acephaline gregarines, including 4 new species, were identified and described from the perivisceral coelom and vesiculae seminales of 13 British earthworm species. The newly described monocystids were Apolocystis megagranulata n. sp. and Nematocystis dendrobaenae n. sp. from Dendrobaena rubida f. subrubicunda and D. mammalis, Monocystis mammaliae n. sp. from D. mammalis, and Zygocystis ictericae n. sp. from Allolobophora icterica f. typica. These 3 earthworm hosts have not been previously examined for monocystids in Britain.
Aerobic Respiration of Kappa Particles from Paramecium aurelia, Stock 51*
Authors: KUNG CHING
Published: May 2007

SYNOPSIS. Kappa particles from killer cultures of stock 51 Paramecium aurelia were purified and their respiration measured polarographically. The slight bacterial contaminations in the kappa preparations were not significant. Freshly collected kappa in dilute buffer at room temperature had an endogenous QO2 of 17.0 ± 1.6 μl/mg dry weight/hr (mean ± standard error). The QO2 decayed 50% in 5 hr. Among the sugars tested only glucose and sucrose increased the respiratory rate of kappa. The di‐ and tri‐carboxylates of the tricarboxylic acid cycle stimulated the respiration of kappa. KCN, CO and 2‐heptyl‐4‐hydroxyquinoline N‐oxide (HOQNO) inhibited respiration. These findings ensure an organismic status for kappa and justify the belief that it is bacterial in origin.
The Life Cycle of Eimeria vermiformis Ernst, Chobotar and Hammond, 1971 in the Mouse Mus musculus1
Authors: TODD KENNETH S. , LEPP DONALD L.
Published: May 2007

SYNOPSIS. The life cycle of Eimeria vermiformis from the mouse Mus musculus is described from experimental infections. The prepatent period was 7 days, and the patent period 7–22+ days. Endogenous stages were in the lower 2/3 of the small intestine. Two generations of schizonts were found. Mature 1st generation schizonts, seen 4 days after inoculation, were 16–25 × 9–16 μ and had long vermiform merozoites. Mature 2nd generation schizonts were first seen 5 days after inoculation. They were 8–18 × 7–14 μ (mean 11.2 × 13.1 μ). Mature microgametocytes, 17–32 × 12–25 μ, were present 6 days after inoculation. Macrogametes with plastic granules were found at the same time.

The life cycle of E. vermiformis is compared with those of other species of Eimeria from Mus.
The Effects of Selected Chemical Agents on the Amoeba‐Flagellate Transformation in Naegleria gruberi*
Authors: YUYAMA SHUHEI
Published: May 2007

SYNOPSIS. Amoeboid Naegleria gruberi grown on an agar surface were induced to transform synchronously into flagellates by changing the pH of the environment from 3.8 to 7.2. Flagellates started to appear 70 min after stimulation, reached the 90% level within the next 30–40 min, and gradually reverted to the amoeboid form in the next several hrs. The presence of previously induced cells did not influence normal induction of transformation, indicating that no interaction took place during transformation.

Inhibitors of oxidative phosphorylation (DNP and cyanide), of protein synthesis (puromycin and cycloheximide), and of RNA synthesis (actinomycin D), delayed or blocked the transformation, suggesting that RNA and protein synthesis are required. Because the flagellated stage is shortened by puromycin treatment, protein synthesis appears to be linked to the duration of the flagellated stage.
Sarcocystis gracilis n. sp. from the Brazilian Tortoise Kinosternon scorpioides*
Authors: LAINSON R. , SHAW J. J.
Published: May 2007

SYNOPSIS. Sarcocystis gracilis n. sp. is described in the tortoise Kinosternon scorpioides (Reptilia, Chelonia) from the Island of Marajó, north Brazil. This appears to be the first record of a sarcosporidian from this group of reptiles.

The cysts are restricted to the skeletal musculature and may reach up to 8.0 mm in length. The cyst wall is extremely delicate, with no visible striations or spines: the trabeculae are well developed and growth of the cyst appears to be largely from caps of proliferative cells at the poles.

The zoites are long and slender, averaging 18.4 × 1.4 μ in fresh preparations. They undergo sudden and rapid gliding movements. The parasite produces striking pathologic changes in the muscle.
Immunologic Analysis by Gel Diffusion of Effects of Prolonged Cultivation on Histomonas meleagridis (Smith)*
Authors: DWYER DENNIS M.
Published: May 2007

SYNOPSIS. Antigens were prepared from each of 4 lines of Histomonas meleagridis: Hm‐L1, a strain highly virulent for both turkeys and chickens; Hm‐L1/C12, Hm‐L1/C24, Hm‐L1/C52, 3 avirulent substrains derived from Hm‐L1 after 12, 24, 52 weeks of in vitro cultivation, respectively. Hm‐L1 strain and the 3 substrains were maintained in liquid nitrogen. Antisera were developed in rabbits against Hm‐L1 and Hm‐L1/C24 parasites. Both antisera were reacted on gel diffusion plates with homologous and heterologous antigens. Two groups of precipitin lines and/or bands designated arbitrarily as A and B, were observed on the slides. Analysis of these bands revealed the common antigenic composition of the 4 histomonads with respect to some of the group A and group B antigens. The concentrations and numbers of precipitin lines in both groups increased, however, with the length of cultivation. These antigenic differences are discussed in the light of their possible relationship to pathogenicity.
BOOK REVIEW…
Authors: Norman D.
Published: May 2007

Trager, W. 1970. Symbiosis. Van Nostrand Reinhold Co., New York, N. Y. 10001. ix + 100 pp. $3.95 (paper).
Avian Trypanosome Division; A Light and Electron Microscope Study1
Authors: DEMAREE RICHARD S. , MARQUARDT WILLIAM C.
Published: May 2007

SYNOPSIS. A magpie isolate of Trypanosoma avium was studied using cultured epimastigotes and trypomastigotes from experimentally infected canaries. Apparent signs of division (double nuclei, flagella, and kinetoplasts) were observed in trypomastigote forms with the light microscope. Three or 4 flagella were seen within a single flagellar pocket in epimastigotes by electron microscopy. It is suggested that apparently dividing trypomastigotes are actually blocked in the process of division.
BOOK REVIEW…
Authors: Levine Norman D.
Published: May 2007

Alexander, M. 1971. Microbial ecology. John Wiley & Sons, New York, N. Y. x + 511 pp. Price $12.95.
The Occurrence of Schellackia and Plasmodium in two Georgia Lizards
Authors: JORDAN HELEN B. , FRIEND MARGARET B.
Published: May 2007

SYNOPSIS. During a 15‐year survey (1956–1970) involving more than 12,000 lizards, the incidence and annual fluctuations of both Plasmodium floridense and Schellackia occidentalis are reported. The occurrence of P. floridense in Anolis carolinensis from the Mainland (Fargo, Georgia area) varied from 52% (1958) to 10% (1964) with an average of 35%, while in Sceloporus undulatus from the same area during the same period it varied from 10% (1969) to 2% (1964) with an average of about 5%.

The occurrence of Schellackia and Plasmodium in both Anolis and Sceloporus from Cumberland Island, and Schellackia from Anolis from 2 other Coastal Islands (Sapelo, 2% and Seahorse, 30%) are reported for the first time. On Cumberland, the only Georgia island thus far studied, where both Anolis and Sceloporus are found together, 16% of Anolis and 13% of Sceloporus had sporozoites of Schellackia sp. in the blood, while 11% of Sceloporus and 21% of Anolis harbored P. floridense.
Is There Selective Mating in Tetrahymena During Genomic Exclusion?1
Authors: ALLEN SALLY LYMAN , WEREMIUK SHARON L. , PATRICK CAROL A.
Published: May 2007

SYNOPSIS. Genomic exclusion is characterized by 2 rounds of mating. If exconjugants from different pairs remated at random after the first mating, we would expect a 1:2:1 ratio for genes present in heterozygous condition in the normal parent. An excess of homozygotes is observed which is similar for 2 different genes, suggesting that 10% of the rematings occur between exconjugants from the same Round 1 pair. Some but not all of these homozygotes can be attributed to a lack of separation of mates after the first round of mating. The rest may result because of differential mortality, induced autogamy or preferential remating.
Elongate and Round Gametocytes of Leucocytozoon simondi (Mathis & Léger) in Ducks Inoculated with Megaloschizonts
Authors: YANG Y. J. , DESSER S. S. , FALLIS A. M.
Published: May 2007

SYNOPSIS. Single megaloschizonts give rise to elongate and round gametocytes, the former outnumbering the latter. Male and female elongate gametocytes develop from merozoites of a single megaloschizont. Elongate gametocytes were seen 2–7 days and round gametocytes 6–11 days after megaloschizonts had been inoculated into ducklings. Experimental evidence indicates that merozoites of megaloschizonts invade blood cells and develop into elongate gametocytes. Other merozoites infect tissue cells and develop into secondary exoerythrocytic schizonts which give rise to round gametocytes. Relapse in Leucocytozoon simondi infections is discussed in relation to megaloschizont‐induced exoerythrocytic schizogony.
Malaria Parasites of Toucans*
Authors: MANWELL REGINALD D. , SESSLER GLORIA J.
Published: May 2007

SYNOPSIS. Of 2 species of malaria parasites described from the toco toucan (Ramphastos toco), one (Plasmodium huffi) has been thought to be of doubtful validity, mainly because the erythrocytic cycle was said to include 2 distinct types of segmenters, varying greatly in size and fecundity. We recently found a parasite in a Swainson's toucan (R. swainsonii) which seems the same as the smaller component of P. huffi, and a 2nd small species of Plasmodium, apparently P. rouxi, in the blood of a sulfur‐breasted toucan (R. s. sulfuratus). Unlike P. huffi, the former is easily transmissible by blood inoculation to canaries, in which it causes a highly fatal infection. It resembles P. nucleophilum structurally, tho there are minor differences. We propose to call it Plasmodium nucleophilum tucani. In sharp contrast to P. huffi, only mature erythrocytes in the blood are parasitized. Death of infected canaries seems to be the result of massive invasion of the internal organs, especially lungs and brain, by exoerythrocytic stages. A number of other bird species, among them the common jungle babbler, lesser hill mynah, ring‐necked and sacred white dove, common pigeon, and Indian hill partridge (chukar) proved essentially refractory, but the collared aracari developed a mild infection much like that observed in toucans. Two young sulfur‐breasted toucans failed to become infected when given heavy dosages of blood from a blue‐eared glossy starling having a naturally acquired infection of Plasmodium nucleophilum, of the type occurring in passerines.
La Sporogenèse chez la Coccidie Aggregata eberthi. Etude en Microscopic Electronique
Authors: PORCHET‐HENNERE ELIANE , RICHARD ALAIN
Published: May 2007

SYNOPSIS. The structure of the oocyst and formation of sporozoites of Aggregata eberthi were studied with the electron microscope. After penetration of the microgamete, a cyst wall containing fine projections is formed beneath the “anhist” layer which is pushed away. The cytoplasm is retracted beneath the cyst wall and is irregular in outline. Lipid inclusions are abundant, while paraglycogen is less so. Vacuoles present in the early stages of development may be instrumental in elaboration of the cyst wall. Granulations appear in the early oocyst cytoplasm and form large compact masses in the sporoblasts, assuming a crystalline appearance (crystalloid) in the sporozoites. The sporoblasts are separated by the coalescence of vesicles. Each sporoblast is surrounded by an epispore and a striated endospore which is perforated by the “dehiscence device.” Three sporozoites of classical structure are formed in each sporoblast.
A Comparative Study of 4 Strains of Hartmannellid Amoebae
Authors: McINTOSH ARTHUR H. , CHANG R. SHIHMAN
Published: May 2007

SYNOPSIS. The biologic characteristics of 4 strains of hartmannellid amoebae were compared. All contained cytoplasmic DNA, degraded thymidine to CO2 and killed chick embryos at 32 C. All except H. glebae secreted a lipogenic toxin and contained antigen(s) capable of sensitizing erythrocytes. A. castellanii, unlike the other 3, also killed chick embryos at 37 C. The Fernald strain of H. rhysodes differed from the other 3 in its higher cytoplasmic grain count of cells labelled with 3H‐thymidine and in its ability to induce the appearance of amoebic antigen within human cells. Increased nuclear labelling in the Fernald strain was observed with increasing concentrations of 3H‐thymidine.
Acetate Metabolism by an Obligate Phototrophic Strain of Pandorina morum1
Authors: PALMER ESTHER G. , TOGASAKI ROBERT K.
Published: May 2007

SYNOPSIS. Acetate metabolism was studied in 2 strains of the green alga Pandorina morum. Both strains were capable of mixotrophic growth in the light, but only one strain was capable of heterotrophic growth in the dark. 14C‐2‐acetate uptake by both strains was studied in the light and dark, in the presence and absence of CO2 and 3(3,4‐dichlorophenyl)‐1,1‐dimethylurea (10−5M). The distribution of radioactivity incorporated into the insoluble, aqueous and chloroform soluble fractions of the cells was determined. The strain incapable of heterotrophic growth in the dark was found to incorporate very little acetate in the dark, and its ability to incorporate acetate into the insoluble fraction was severely limited under all conditions. Incorporation into the aqueous and chloroform‐soluble fractions in the light was similar in both strains. The reduced incorporation into the insoluble fraction was almost totally the result of limited incorporation of acetate into polysaccharides by the obligate phototrophic strain.
Two New Subspecies of Herpetomonas muscarum (Leidy, 1856) Kent, 1880
Authors: ROGERS WILLIAM E. , WALLACE F. G.
Published: May 2007

SYNOPSIS. Herpetomonas muscarum muscarum n. subsp. was isolated from Musca domestica L. In culture at 20 C it assumed the opisthomastigote (up to 15%), double‐flagellate and flagellate promastigote forms. At 30 C or with 4% urea added to cultures at 20 C, the proportion of opisthomastigotes was greater (up to 40%). In experimentally infected flies only transient infections, which included both opisthomastigotes and promastigotes, occurred. The promastigotes were 15–30 μ long and the kinetoplast was small and subspherical or transversely elongate. H. muscarum ingenoplastis n. subsp. was isolated from Phormia regina (Meigen). In culture at 20 C almost all individuals were double‐flagellate promastigotes 20–40 μ long and less than 1% were opisthomastigotes. At 30 C or with added urea there was no increase in the proportion of opisthomastigotes and the cultures were not vigorous. In experimentally infected flies opisthomastigotes were 5–39% of the population depending on the part of the gut sampled. In all stages the kinetoplast was large (1.5–2.5 μ long) and tear‐drop‐shaped with the point directed posteriorly.

In artificially mixed cultures of H. m. muscarum and H. m. ingenoplastis the former predominated after a short time and eventually survived alone. A mixed culture that was about 98%H. m. muscarum was fed to Phormia regina and produced heavy pure infections of H. m. ingenoplastis, which lasted for 22 days with no indication of decline. No evidence of cyst formation was found in either subspecies.