bluuebunny/crossref_metadata_2025 huggingface dataset:
Calcification of Spirostomum ambiguum
Authors: BIEN SAUL M. , PRESTON FRANCIS B.
Published: May 2007

SYNOPSIS. A method is described for cultivation of large numbers of Spirostomum ambiguum, calcified intracellularly with hydroxyapatite (bone salt deposits). The structure and activity of living animals at various stages of calcification is described and also illustrated with unstained and silver impregnated ciliates. A suitable modification of von Kossa's method for localization of insoluble phosphate deposits is given.
Ultrastructural Observations on Aging of Stationary Cultures and Feeding in Ochromonas*
Authors: SCHUSTER F. L. , HERSHENOV BETTY , AARONSON S.
Published: May 2007

SYNOPSIS. Changes accompanying aging of stationary cultures of Ochromonas danica were examined with the electron microscope. The cultures included light‐ and dark‐grown populations ranging in age from 3 days to 5 weeks. Cells from the youngest cultures contained minimal amounts of lipid and a distinct leucosin vacuole. After 1 week, the number of lipid globules in the cytoplasm increased. The amount of lipid increased progressively in cells from older cultures until the leucosin vacuole was obliterated by the coalescing spheres. Cells from cultures older than 3 weeks showed a general breakdown of cytoplasmic integrity. An area of pinocytotic activity was also present; a relationship between this anterior region and blebs arising from the cell membrane is suggested.
Influence of Reticulocytosis on the Course of Infection of Plasmodium chabaudi and P. berghei*
Authors: OTT KAREN J.
Published: May 2007

SYNOPSIS. Reticulocytosis, stimulated by the destruction of red blood cells by phenylhydrazine, altered the course of infection of both Plasmodium chabaudi and P. berghei in the mouse. P. chabaudi, lacking a preference for reticulocytes, was adversely affected when young cells were present in abundance. Parasitemias diminished and most of the animals survived the otherwise fatal infection. P. berghei preferentially invaded reticulocytes to the extent that the parasitemia became contained largely in the reticulocyte population. This was accompanied by a delay in time to death.
A Hyperparasite of Entamoeba suis from the Indian Domestic Pig Sus scrofa*
Authors: DAS N. , RAY H. N.
Published: May 2007

SYNOPSIS. A hyperparasite probably related to some lower protistan was found in the cytoplasm of Entamoeba suis Hartmann. These were very minute bodies with a central Feulgen‐positive dot, the nucleus, and a bordering cytoplasmic ring with an alcian blue‐positive reaction. This organism appeared to interfere with the synthesis of DNA & RNA in the host amoeba as reflected in its relative stainability with Feulgen or pyronin‐methyl green. The suggestion is that the parasitized amoebic cysts were most likely rendered nonviable.
A Continuous Culture Device for Protozoan Cells
Authors: COOK J. R.
Published: May 2007

SYNOPSIS. A continuous culture device suitable for controlled growth of Euglna gracilis is described. It could probably be adapted to other similar cell types with generation times no greater than 150–200 hrs.
Cholesterol Inhibition of Pentacyclic Triterpenoid Biosynthesis in Tetrahymena pyriformis*†
Authors: CONNER R. L. , LANDREY J. R. , LANDREY J. R. , BURNS C. H. , MALLORY FRANK B.
Published: May 2007

SYNOPSIS. Tetrahymena pyriformis synthesizes tetrahymanol and “diplopterol” from acetate, mevalonate or squalene. The formation of these pentacyclic triterpenoid alcohols is inhibited by the addition of cholesterol to the culture fluid of the ciliates. Cholesterol also inhibits the biosynthesis of squalene from acetate or mevalonic acid. The synthesis of other terpene derivatives from acetate and mevalonate continues in the presence of cholesterol, thus suggesting that a major block occurs after “isoprene” formation and before squalene formation. Further, inhibition of squalene conversion to the pentacyclic alcohols by cholesterol has been established.
Volumetric Relationships of Symbiotic Zoochlorellae to Their Hosts
Authors: SUD GIAN CHAND
Published: May 2007

SYNOPSIS. Zoochlorellae of 7 ciliates from 3 different localities around Madison, Wisconsin, were identified from live and stained preparations. A relationship was worked out between volume of zoochlorellae and volume of their hosts. The zoochorellae which occupied the highest percentage of the space of the host cell were those in Holosticha viridis; the range in the 7 ciliates was 10–56%. There appeared to be some correlation between the locality of collection and density of the Chlorella population in the host.
Cryoprotectants for Crithidia fasciculata Stored at ‐20 C, with Notes on Trypanosoma gambiense and T. conorhini
Authors: O'CONNELL KATHLEEN M. , HUTNER S. H. , FROMENTIN HUGUETTE , FRANK OSCAR , BAKER HERMAN
Published: May 2007

SYNOPSIS. Cryoprotectants were tested in both complex and semidefined media for the trypanosomatid Crithidia fasciculata. Near log‐phase or end‐of‐log‐phase cultures were frozen for 24–48 hr at ∼ ‐20 C, then warmed in air to room temperature. Immediate motility was correlated with viability. The best protectant of the 83 tested was glycerol at ∼ 10% (w/v). Survival without cryoprotectant was rare. Outstanding cryoprotectants (perhaps also useful solvents for drugs poorly soluble in water) were: ethylene glycol; 2,2′‐dioxyethanol (diethylene glycol); 1,2,4‐butanetriol; 1,4‐cyclohexanediol; dimethylsulfoxide; propylene glycol; and N‐acetylethanolamine. Several sugars were active, e.g., D‐arabinose, sucrose, and sorbitol. Trypanosomes tolerated cryoprotectants much less; tolerance was better in growth media than in suspension media. Trypanosoma gambiense was grown in blood‐enriched media + 2‐2.5% glycerol, suspended in 20% (w/v) glycerol. then frozen; this permitted 3‐week survival. T. conorhini survived 4 weeks after growth in media containing glycerol 2.5%+ ethylene glycol 4%+ rutin 1.0 mg per 100 ml.
Fine Structure of Colpoda steinii During Encystment and Excystment
Authors: TIBBS JACK
Published: May 2007

SYNOPSIS. The encystment and excystment of Colpoda steinii was examined by electron microscopy. Cellular organelles including cilia are retained in the cyst without any fundamental alteration in structure. During encystment, the cell becomes surrounded by 2 coats, the inner of which is the more substanial and regular and is about 1600 A or more thick. It is probably formed in the main from material contained in bodies which have no obvious structure and which may be seen in the cell during cyst formation. Discharging vacuoles containing sheet‐like material, probably derived from ingested bacteria, are particularly visible during encystment but probably play no direct role in the formation of the main cyst coat. During excystment, this coat is eroded away and, when it becomes thin enough, the motile cell bursts its way out.
Purine and Pyrimidine Synthesis by the Avian Malaria Parasite, Plasmodium lophurae*
Authors: WALSH CHARLES J. , SHERMAN IRWIN W.
Published: May 2007

SYNOPSIS. Purine and pyrimidine biosynthesis in the avian malaria parasite Plasmodium lophurae and its host cell, the duck erythrocyte, were investigated in vitro. Pyrimidine synthesis, as measured by the incorporation of C14‐NaHCO3 into cytosine, uracil and thymine was slight in uninfected duck erythrocytes, whereas infected erythrocytes and erythrocyte‐free parasites had high rates of incorporation of NaHCO3 into these bases. In addition, orotidine‐5′‐monophosphate pyrophosphorylase and thymidylate synthetase, 2 enzymes of the pyrimidine biosynthetic pathway, were found in cell‐free extracts of the plasmodia. Purine synthesis was measured by determining the extent of incorporation of C14‐Na‐formate into adenine and guanine. Uninfected and infected erythrocytes had similar rates of Na‐formate incroporation into adenine. whereas free parasites incorporated little of this compound into adenine, or guanine. On the other hand, the incorporation of Na‐formate into guanine was 54% higher in infected erythrocytes than in uninfected erythrocytes.

It is suggested that P. lophurae synthesizes purines to a limited extent, and derives most of its purines from the host erythrocyte. The greater incorporation of Na‐formate into guanine by infected cells, and its low incorporation into free parasites may be accounted for by parasite conversion of host cell adenine (in the form of ATP) into guanine. Pyrimidine biosynthesis in infected cells can be accounted for by de novo synthesis by the parasite itself.
Isolation of Toxoplasma gondii from the Feces of a Helminth Free Cat
Authors: DUBEY J. P.
Published: May 2007

SYNOPSIS. Toxoplasma gondii was isolated from the feces of one of 2 cats infected orally with the Beverley strain of T. gondii.

Toxoplasma gondii infects many species of warm blooded animals including man but its mode of transmission is not fully known. Congenital infection and cannibalism are the 2 accepted modes of transmission. Besides, nematode eggs have been suggested as another effective way of to transmission by Hutchison whose work has been reviewed in detail (5).
Circadian Rhythm of Pattern Formation in Populations of a Free‐Swimming Organism, Tetrahymena*
Authors: WILLE JOHN J. , EHRET CHARLES F.
Published: May 2007

SYNOPSIS. In a preliminary search for a phototactic response in Tetrahymena, we discovered instead an autotactic phenomenon of pattern formation produced by motile free‐swimming cells in a dense culture. This pattern of cell aggregation is remarkably similar to the Bénard‐cell patterns of classical physical chemistry, and reminiscent of the streaming patterns of motile microorganisms.

In a study of light effects on the rate of pattern formation, we found that it has an endogenous circadian component, and is strongly dependent on cell concentration.
The DNA of Acanthamoeba spp.; A Method for Extraction and Its Characterization
Authors: ADAM KATHERINE M. G. , BLEWETT D. A. , FLAMM W. G.
Published: May 2007

SYNOPSIS. A method is described which permits the recovery of a high yield of undegraded DNA from Acanthamoeba castellanii. The DNA of A. castellanii is comprised of 2 species: the buoyant density of the major component is 1.720 and of the minor component, 1.693. The renaturation characteristics of the minor component suggest that it is of mitochondrial origin. Two components are also present in the DNA of A. palestinensis, A. polyphaga and A. astronyxis. The buoyant densities of major and minor components differ between species.
Participation of the Undulating Membrane in the Formation of Oral Replacement Primordia in Tetrahymena pyriformis*
Authors: FRANKEL JOSEPH
Published: May 2007

SYNOPSIS. Cells of T. pyriformis GL‐C, transferred from a complete axenic medium to a medium lacking amino acids, cease dividing after several hours, and instead begin to undergo oral replacement. This process can be synchronized by a single long 33.8 C treatment. Oral replacement was also observed during stationary phase of normal culture growth in cells of strain GL‐C and WH‐6 (syngen 1).

In strain GL‐C the oral replacement primordium is initiated by the appearance of a small number of kinetosomes adjacent to the anterior end of kinety 1, just posterior to the undulating membrane (UM). The UM then loses its cilia and becomes disorganized, and is thus converted into a field of kinetosomes which is broadest near its posterior end. This UM‐derived field then becomes joined with the much smaller field which had appeared earlier near the anterior end of kinety 1. As a consequence, the right margin of the UM‐derived field becomes continuous with the anterior end of kinety 1, and thus comes to appear as an anterior extension of this kinety. The membranelles and UM of the new oral area differentiate within this composite field. While this is going on, the membranelles of the old oral area are progressively resorbed; these old membranelles always remain spatially separate from the oral replacement primordium.

In strain WH‐6, the stomatogenic field initially formed adjacent to kinety 1 is substantial, and the role of the UM kinetosomes in stomatogenesis is less obvious than in strain GL‐C. The posterior portion of the UM probably contributes to the oral replacement primordium, while the anterior portion is resorbed. In this strain small supernumerary primordia are occasionally seen adjacent to the portion of kinety 2 which is nearest to the posterior region of the UM.

It is suggested that the junction between the posterior portion of the UM and the neighboring cortex can serve as an inductive zone for initiation of stomatogenesis, the UM itself having a varying capacity for direct provision of kinetosomes for the stomatogenic field. The flexibility of the stomatogenic site in T. pyriformis is discussed in relation to the apparent restriction of potentialities in peniculine ciliates such as Paramecium.
Accumulation of Parathion and DDT by Some Algae and Protozoa*†
Authors: GREGORY WESLEY W. , REED JOHN K. , PRIESTER L. E.
Published: May 2007

SYNOPSIS. Cultures of Anacystis nidulans, Scenedesmus obliquus, Euglena gracilis, Paramecium bursaria, and P. multimicronucleatum were exposed separately to 2 pesticides. They concentrated DDT 99 to 964 times and parathion 50 to 116 times when treated at 1 ppm (w/v), then held for 7 days. At the sensitivities of the analyses, no metabolites of the pesticides were detected in any of the organisms.
Quelques Particularités Structurales de Cyanophora paradoxa Korsch., Protozoaire Flagellé
Authors: MIGNOT J. P. , JOYON L. , PRINGSHEIM E. G.
Published: May 2007

SYNOPSIS. An electronmicroscopic study of Cyanophora paradoxa shows that its cuticle, vestibule, flagellar canals, and chondriome differ from those of Cryptomonadina. The flat cortical vesicles, peripheral tubules, as well as flagellar canals, which are surrounded by tubules, the anterior opening into an oblique depression and the posterior into a ventral groove, are more characteristic of Dinoflagellida. It is evident thus that, following Chadefaud, Cyanophora ought to be classified with primitive Dinoflagellida.

Certain cytologic characteristics, especially the structure of the transitional zone (of the flagella), lead us to believe that Glaucocystis nostochinearum also belongs in this group.
Oral Structure Development and Nuclear Behavior During Conjugation in Paramecium aurelia1
Authors: HANSON EARL D. , GILLIES CONCETTINA , KANEDA MASAO
Published: May 2007

SYNOPSIS. Conjugation in Paramecium aurelia has been studied in live and sectioned cells and oral development studied following ultraviolet microbeam irradiation. The live cells allow a clear correlation to be made between nuclear behavior and gullet development. The paroral cone lies at the level of the buccal overture. The new oral area develops while the old one is still present, the latter structure being still visible after the conjugants have separated. Sectioned material confirms the fact of cytoplasmic fusion at the level of the paroral cones. It also confirms the appearance of new buccal organelles on the right side of the buccal overture of the pre‐existing gullet. Ultraviolet microbeam irradiation of the buccal area shows that the posterior edge of the buccal overture must remain undisturbed for normal development. Irradiation of the anterior edge of the buccal overture also affects development. These results differ from earlier work on fissioning cells. Discussion of these differences leads to the conclusion that the factors controlling stomatogenesis are developmentally regulatory.
Further Studies on in vitro Development of Eimeria bovis and Attempts to Obtain Second‐Generation Schizonts*
Authors: HAMMOND DATUS M. , FAYER RONALD , MINER MERTHYR L.
Published: May 2007

SYNOPSIS. Eimeria bovis merozoites occurred in tissue culture medium removed from Leighton tube cultures of embryonic bovine tracheal cells beginning 12‐14 days after inoculation with 270,000‐369,000 sporozoites per tube. The number of merozoites produced in these cultures increased daily until a peak was reached 18‐21 days after inoculation. In 3 experiments an average of 2.0–15.6 million merozoites per tube was produced during the 20‐day observation period. When such merozoites were frozen in liquid nitrogen and stored 26–42 days, some were motile upon thawing. These merozoites as well as others freshly obtained from cell cultures and from calves were inoculated into 11 different types of cultured mammalian cells including primary, cell line and established cell line cultures. Some merozoites were exposed to substances normally found in the lumen of the gut, before or at the time of inoculation. Altho small numbers of intracellular merozoites were found, no further development was observed. Gametocytes were observed in the cecum of a calf 4 days after merozoites from cell cultures were introduced into a ligated cecum of the calf.
Quantitative Studies on the Growth ofAllogromia laticollaris(Foraminifera)
Authors: LEE JOHN J. , McENERY MARIE E. , RUBIN HOWARD
Published: May 2007

SYNOPSIS.The growth and reproduction ofAllogromia laticollariswas studied. More schizozoites were generally produced in mixtures of food organisms than on single algal foods. In the presence of moderate numbers of bacteria, cultures withPhaeodactylum tricornutum, Chlorococcumsp.,Nannochlorissp., and an unidentified chlorophyte (BL‐1), added singly, were also highly productive. Schizogony was the dominant asexual form of reproduction. Binary fission and cytotomy also occurred in bacterized otherwise unfed controls.35S and32P are convenient labels for measuring growth ofA. laticollariswhen introduced into the system in the range of 1 × 104‐ 1 × 105dpm/ml (32P specific activity ∼ 2.03 MCi/g;35S specific activity ∼ 95 μCi/g). Small allogromiids grew faster than did larger ones. By means of the Taylor series modification of the classical least‐squares method, a continuous life‐cycle representation was calculated forA. laticollarisfor the conditions of the experiment. Four points of cell volume growth were maxima for reproduction: 1.0 × 107μ per organism for curve I; 2.2 × 107μ3and 1.2 × 107μ3for curve II; and 6.7 × 107μ3for curve III.
Comparative Toxicity of Gonyaulax monilata and Gymnodinium breve to Annelids, Crustaceans, Molluscs and a Fish
Authors: SIEVERS ANITA M.
Published: May 2007

SYNOPSIS. Toxicities of laboratory cultures of the dinoflagellates Gonyaulax monilata and Gymnodinium breve were compared using fish, annelids, crustaceans and molluscs. Toxicity was evaluated as mortality over a 48‐hr test period in 100%, 75% 50%, 25% and 10% concentrations of dinoflagellate cultures. Responses of the assay animals indicated that the dinoflagellates do not produce the same toxins. Effects of the toxins seemed uniform within each major group of animals tested. Fish were most sensitive to both G. breve and Gonyaulax monilata; crustaceans were resistant to both; annelids and molluscs were more sensitive to G. monilata than to G. breve.
Platyamoeba stenopodia. n. g., n. sp., a Freshwater Amoeba*
Authors: PAGE FREDERICK C.
Published: May 2007

SYNOPSIS. Platyamoeba stenopodia n. g., n. sp., isolated from a lake in Alabama, is an amoeba with flattened form, usually more than 2.5 × as long as broad, the anterior half hyaline and the posterior half granular, with a single vesiculate nucleus at the posterior edge of the hyaline region. It forms a transitory floating stage with slender, hyaline pseudopods. Its cyst is spherical, uninucleate, with a smooth inner wall and a thinner, closely applied outer wall, which is often slightly wrinkled. Length of locomotive amoeba 15–36 μ diameter of cyst 7–11.5 μ Reproduction by binary fission with mesomitotic nuclear division, the nuclear membrane disappearing in prophase. The genus Platyamoeba is erected for amoebae including this organism; the type species is P. placida.
Electron Microscopic Studies on the Intra‐flagellar Structures of Trypanosomes*
Authors: FUGE HARALD
Published: May 2007

SYNOPSIS. The intraflagellar structure (IFS) of the flagella of Trypanosoma brucei was examined on the basis of ultrathin sections in various planes. The IFS is composed of filaments approximately 50 A thick. These filaments seem to be identical with the protofilaments found earlier to be the basic elements of the contractile flagellar fibrils. The fibrillar system is firmly connected with the IFS and the latter is attached to the flagellar membrane by filaments. The lattice‐like appearance of the IFS is caused by longitudinal and oblique filaments running in different planes. The structure of this network is discussed in detail. The IFS may serve as an abutment for the contractile flagellar fibrils.
Behavior and Pathogenicity of Tritrichomonas foetus in Chick Liver Cell Cultures*
Authors: KULDA JAROSLAV , HONIGBERG B. M. , Kulda Jelena
Published: May 2007

SYNOPSIS. Clones of Tritrichomonas foetus, referred to as strains KV‐1, DK‐2, and UT‐1, which were judged by subcutaneous mouse assay to differ in pathogenicity, had different effects on trypsin‐dispersed liver cell cultures prepared from 3 lines (Light Brown Leghorn, Massachusetts Brown, Massachusetts Low Growth) of chicks. The general pattern of parasite‐cell interaction was similar in all cell cultures, but the intensity of certain responses of the cultures to trichomonads, reflected best in the levels of macrophage activity, depended on the line of chicks.

The mild UT‐1 strain was readily engulfed and digested by the macrophages, caused very little damage to the epithelial cells and fibroblasts, and had a minimal inhibitory effect on the division rate of the latter. Many abnormal changes were seen, however, in the cytoplasm and nucleil of fibroblasts and epithelial cells in cultures exposed to strains of high (KV‐1) and intermediate (DK‐2) pathogenicity or to cell‐free filtrates of rich active cultures (henceforth referred to as filtrates) of these strains. The changes included retraction of cytoplasm which caused cell‐free spaces to appear in the sheets of fibroblasts and around the epithelial islands; the islands became detached from the surrounding fibroblast sheets and tended to form multilayered cell mounds. The flagellates and filtrates of KV‐1 strain greatly inhibited fibroblast division, and similar, but less pronounced, inhibitory effects were exerted by DK‐2 strain and its filtrates. Trichomonads of all 3 strains did not attach themselves to fibroblasts and epithelial cells. Thus the abnormal changes in cultures infected with KV‐1 and DK‐2 parasites apparently were caused by some toxic substances produced by the trichomonads, which had to be responsible also for the identical changes in cultures exposed to filtrates of these strains. KV‐1 and DK‐2 strains inhibited the phagocytic activity of the macrophages in the early stages of infection, the former causing stronger and longer lasting inhibition. Trichomonads of KV‐1 strain multiplied actively within the phagocytes which developed degenerative changes and ultimately burst, releasing healthy parasites into the medium. DK‐2 flagellates, altho incapable of dividing inside the macrophages, usually were not digested and caused degeneration of the cells which contained them.
The Fine Structure of the Gregarine Lankesteria culicis Parasitic in the Yellow Fever Mosquito Aedes aegypti
Authors: WALSH R. D. , CALLAWAY C. S.
Published: May 2007

SYNOPSIS. The fine structure of the eugregarine Lankesteria culicis from the larvae of the mosquito Aedes aegypti was examined by light and electron microscopy and compared with that of other gregarines. The cell organelles found in L. culicis included a nucleus, mitochondria, Golgi‐complexes, endoplasmic reticulum, vesicles, droplets, granules and lipid bodies.

The surface of L. culicis was composed of a highly differentiated membrane‐cortex, differing slightly from that of other eugregarines. This complex was limited by a unit membrane, the plasmelemma, and underlying cortical laminae which appeared to be composed of several layers. The homogeneous electrondense layer present in Pyxinoides balani was greatly diminished or absent in L. culicis.

A series of laminar folds supported by ground substance and longitudinal subpellicular fibrils gave the organism's surface a ridge‐like appearance. Permanent cytostome‐like openings in the surface, which appeared to be supported by a narrow band of thickened cortex, were present as specializations of the surfacemembrane complex. The structural composition of the parasite appeared quite striking in that it was made up almost entirely of vesicles, granules, and droplets which were absent only in the area of the protomerite. The mitochondria were usually found just beneath the surface or near the nucleus. Mitochondria were also seen in the region of demarcation between the protomerite and deutomerite.
Lankesteria barretti n. sp. (Eugregarinida, Diplocystidae), a Parasite of the Mosquito Aedes triseriatus (Say) and a Review of the Genus Lankesteria Mingazzini*
Authors: VÁVRA JIŘÍ
Published: May 2007

SYNOPSIS. Lankesteria barretti n. sp. (Eugregarinida, Diplocystidae) is named from the mosquito Aedes triseriatus in Texas. The young cephalins occur within the midgut epithelial cells. When they reach a length of about 150–200 μ they rupture the host cell and are released into the space between the epithelium and the peritrophic membrane, becoming gamonts. These grow to about 140–310 by 40 μ at the anterior end and 12 μ at the posterior end. When the host pupates they enter the lumen of the Malpighian tubules; pairs join in syzygy by their anterior ends and later more laterally. Each pair forms a spherical gametocyst about 60–100 μ (exceptionally 250 μ) in diameter. A large number of oocysts develop in each gametocyst. The mature oocysts are spindle‐shaped, 11 by 5.4–5.7 μ, and contain 8 elongate sporozoites and a refractile residuum. The gametocyst wall breaks down, releasing oocysts in the Malpighian tubules of the host when it is adult. The oocysts pass out in the feces and presumably infect new larvae by ingestion. The cephalins and gamonts of L. barretti differ from those of L. culicis (of Aedes aegypti) in having a relatively anterior instead of a central nucleus and in lacking a noticeable mucron; its longitudinal folds are not as well‐developed as in L. culicis, and its paraglycogen granules are larger. The fine structure of L. culicis and L. barretti is described in detail. Their gamonts have a polar ring but no definite conoid. The taxonomy of the genus is reviewed, but its species have been so poorly described that it is impossible to be sure whether they are all really Lankesteria. About 19 species have been described (5 from turbellaria, 8 from tunicates, perhaps 1 from Amphioxus, 1 from the chaetognath Sagitta sp., 1 from Phlebotomus and 3 from mosquitoes).
Alpha, an Infectious Macronuclear Symbiont of Paramecium aurelia
Authors: PREER LOUISE B.
Published: May 2007

SYNOPSIS. A spiral, rod‐ or crescent‐shaped symbiont here designated alpha, is present in the macronucleus of killer stock 562, syngen 2 of Paramecium aurelia. This stock has a cytoplasmic symbiont, kappa, as well as alpha. Lines were obtained which had only alpha, others which had only kappa, and some which had neither. It was possible to purify and separate both kinds of symbiont from homogenates of stock 562 using an ECTEOLA column. The killing action of this stock is due to kappa, not alpha. Observations on the structure of alpha with the electron microscope indicate that alpha, like the cytoplasmic symbionts in this species, is a bacterium. Alpha is never seen in the micronucleus, is rarely found in the cytoplasm, but abounds in the macronucleus. If paramecia are allowed to grow slowly after autogamy, alpha passes from the old macronuclear fragments, infects the new macronucleus, and all animals retain alpha. In exautogamous paramecia growing at maximum fission rate, however, alpha often does not infect the new macronucleus and is lost from many lines when the old macronuclear fragments disappear. In mixed cultures containing alpha‐bearing and alphafree paramecia, it has been found that alpha readily invades the macronucleus of paramecia of susceptible stocks. Homogenates of alpha‐bearing cultures are also infective. Infection is highly specific, occurring in only 6 of the 44 stocks of P. aurelia in which infection was attempted, and these 6 are all syngen 2. It is suggested that the short rod or crescent form of alpha is the reproductive form, while the elongated spiral form is probably the invasive motile form.
Some Observations on the Sporogonic Cycle of Plasmodium schwetzi, P. vivax and P. ovale in Five Species of Anopheles
Authors: COLLINS WILLIAM E. , ORIHEL THOMAS C. , G PETER , JETER MARVIN H. , GELL LEONARD S.
Published: May 2007

SYNOPSIS. The sporogonic cycles of Plasmodium schwetzi, P. vivax and P. ovale are distinctly different with regard to rate of sporozoite development and median oocyst diameter. Differences in the oocyst structure, particularly with regard to the presence of inclusions in those of P. schwetzi, were noted. These findings tend to support the continued designation of these parasites as distinct and separate species.
Observations on Iridia diaphana, a Marine Foraminifer
Authors: MARSZALEK DONALD S.
Published: May 2007

SYNOPSIS. Iridia diaphana, a marine foraminifer, was used as a subject for observations on grano‐reticulate pseudopods. The organism readily forms a pseudopod net and its behavior is roughly predictable. Test composition varies with the environment; test shape is more constant. Pseudopod form and structure were observed by transmitted plane and polarized light microscopy, by freeze‐drying and scanning electron microscopy, and by thin section studies in the transmission electron microscope. Rigidity is probably due to the numerous 250 A dia. microtubules in the pseudopods. Other organelles observed include mitochondria, vesicles and vacuoles. The plasmalemma may have numerous villous projections. Pseudopod form in I. diaphana does not closely resemble that of Allogromia laticollaris as reported by Wohlfarth‐Bottermann (25). A pseudopod may be composed of several membrane‐bound units of cytoplasm, or of a single unit of cytoplasm. A reassessment of the theories of the mechanism of cytoplasmic streaming in foraminiferan pseudopods is necessary.
Development of Eimeria auburnensis in Cell Cultures
Authors: CLARK WAYNE N. , HAMMOND DATUS M.
Published: May 2007

SYNOPSIS. Monolayer established cell line cultures of bovine kidney (Madin‐Darby) and human intestine (Intestine 407), as well as embryonic bovine tracheal and embryonic spleen cell line cultures were inoculated with E. auburnensis sporozoites and observed for a maximum of 22 days. Mature 1st generation schizonts developed in the kidney, tracheal and spleen cells. In the intestine cells, trophozoites were seen in 3 of 4 experiments, but schizonts were not found. Sporozoites penetrated cells, beginning within a few minutes after inoculation. Penetration was usually accomplished within 10 seconds, and the body of the sporozoite underwent a slight constriction as it passed thru the host cell membrane. Some sporozoites left cells. Numerous intracellular sporozoites were observed in kidney, tracheal and spleen cultures. Crescent bodies were seen in the parasitophorous vacuole as early as 1 day after inoculation. At this time, the nuclei of most intracellular sporozoites had changed from vesicular to compact.

Beginning 4 days after inoculation, enlarged sporozoites and parasites having a sporozoite shape, but with 2‐5 nuclei, were frequently seen. These enlarged sporozoites and sporozoite‐shaped schizonts evidently transformed into trophozoites and spheroidal schizonts by means of lateral outpocketings. Few trophozoites were seen. More immature schizonts developed in kidney cells than in the other cell types. The numbers of mature schizonts observed in kidney and tracheal cells were similar, but development occurred less consistently in the latter. Few immature and mature schizonts developed in spleen cells. Mature schizonts, first seen 9 days after inoculation, were considerably smaller than those reported from calves. Some motile merozoites were seen; evidently no development beyond these occurred. The nucleus and nucleolus of host cells were enlarged; this enlargement was not as pronounced as in infections in calves. Multiple host cell nuclei were frequently observed. Degenerative changes in the cultured cells and in the parasites usually occurred, beginning 9‐17 days after inoculation; these were more pronounced in the spleen cells than in the others.
Cilia Regeneration in Stentor: Inhibition, Delay and Abnormalities Induced by Griseofulvin
Authors: MARGULIS LYNN , NEVIACKAS JAMES A. , BANERJEE SUMANA
Published: May 2007

SYNOPSIS. Stentor coeruleus were experimentally induced to shed their membranellar bands (MB), structures consisting of rows of cilia and their basal bodies. Control stentors entirely regenerate their MB's within 8‐10 hours according to a well‐known pattern. Stentors replaced in medium containing the fungicide and mitotic spindle inhibitor griseofulvin (10‐5M) could be reversibly inhibited from regeneration for about 3 to more than 24 hours. If griseofulvin‐inhibited cells were removed and washed, they regenerated like the controls. After about one day in 10‐5M griseofulvin and at lower concentrations stentors eventually regenerated in the presence of the drug, but abnormally.

Normal unshed stentors show certain minor cytological effects and are unable to divide in griseofulvin (10‐5M); however, they can be maintained swimming actively for several weeks in nonlethal concentrations of the drug. Altho some induced abnormalities persist after removal from griseofulvin, all washed cells eventually revert to normal.
The Cell Cycle in Crithidia fasciculata. Temporal Relationships between Synthesis of Deoxyribonucleic Acid in the Nucleus and in the Kinetoplast1, 2
Authors: COSGROVE WILLIAM B. , SKEEN MARIANNE J.
Published: May 2007

SYNOPSIS. Autoradiographic technics with tritium‐labeled thymidine have been used to determine G1, S, G2 and D for the kinetoplast and the nucleus of Crithidia fasciculata at 15, 25 and 32 C. The kinetoplast completes division before the nucleus at all 3 temperatures. The S phases of both organelles occur in approximate synchrony and are approximately equal in length but the nucleus begins and completes S before the kinetoplast at the 2 lower temperatures. This relationship is reversed at 32 C. Most of the effect of temperature on generation time is due to its effect on the length of S.

The results are compared with similar studies on C. luciliae, Trypanosoma mega, other protozoa and tissue cells in culture. The role of the approximate synchrony of nuclear and kinetoplastic cycles in maintenance of the kinetoplastic condition is discussed and the hypothesis is proposed that this synchrony results from the sharing by nucleus and kinetoplast of the same mechanism for the production of the deoxyribonucleotides used in replication of their respective DNAs.
A New Species of Sarcocystis Parasitic in the Whale Balaenoptera borealis
Authors: AKAO SHINKICHI
Published: May 2007

SYNOPSIS. A new species of Sarcosporidian, Sarcocystis balaenopteralis n. sp. is described from muscle of a whale Balaenoptera borealis. Its Miescher's tubes are thread‐like and lie parallel to the muscle fibers. The ultrastructure of its proliferative forms is similar to that of other species of Sarcocystis. An unknown organelle was found in front of the nucleus. Pictures of endodyogeny were obtained.
Metamorphosis in Tokophrya infusionum; an Electron‐Microscope Study
Authors: HASCALL GRETCHEN K. , RUDZINSKA MARIA A.
Published: May 2007

SYNOPSIS. In Tokophrya infusionum metamorphosis from a ciliated swimming embryo to a sessile organism with a stalk, disc, and tentacles lasts only 3 minutes. The remarkable speed of meta‐morphosis was clarified by an electron‐microscope study of embryos before and during metamorphosis. Ultrathin sections have revealed that the embryo has at the anterior end of the body a number of specialized structures, such as dense bodies containing the precursor material for the disc and stalk, and microtubules which align the dense bodies into rows leading to pit‐kite invaginations of the pellicle at the tip of the anterior end. At meta‐morphosis the embryo settles down on this end and the precursor material is released thru the pits to the outside. At the same time the body of the embryo invaginates at this end, forming a cavity which becomes deeper and narrower until it acquires the shape of a channel. The 1st drops released from the dense bodies spread out on the substrate, forming the disc. The rest of the material, secreted into the channel, solidifies there to form the stalk. It seems obvious that the channel serves as a mold for the stalk, since after completion of the stalk the channel disappears. The stalk is structureless with no limiting membrane; it is outside the boundaries of the cell. Both the stalk and disc are extra‐cellular organelles.

Of the new organelles appearing at metamorphosis, only the stalk and disc are formed de novo. The electron‐microscope study disclosed that the embryo has internal parts of tentacles composed of a tube formed of microtubules. At the distal end of the microtubules is a ring of dense material. During metamorphosis the microtubules, together with the dense ring, grow out of the body, and along with them the pellicle and plasma membrane to form the external part of the tentacle.
The Biological Clock in Chlamydomonas reinhardi
Authors: BRUCE VICTOR G.
Published: May 2007

SYNOPSIS. Chlamydomonas reinhardi has a biological clock regulating phototaxis in dividing and non‐dividing cultures; it also can exert some control on growth of continuous cultures. The period length is ∼ 24 hr; it is temperature‐compensated and not dependent on the average growth rate. The rhythm can be entrained or phased by light‐dark conditions. In dividing cultures a periodic fluctuation in cell number and total protein persists in continuous light.
Synchronization of the Cell Cycle of Tetrahymena by Starvation and Refeeding*
Authors: CAMERON I. L. , JETER J. R.
Published: May 2007

SYNOPSIS The present report describes a simple and useful method for synchronizing mass cultures of the ciliate Tetrahymena pyriformis. The method employs a nutritional approach which involves starvation of the cells in a non‐nutrient phosphate buffer followed by refeeding with an enriched nutritional growth medium. It takes 240 minutes after refeeding before the first cells start to divide. Radioautographic and DNA determinations taken together show that starved cells are stalled in the GI nuclear DNA condition and that essentially all of the cells replicate their DNA prior to their first cell division.
Synchronization of Leishmania tarentolae by Hydroxyurea
Authors: SIMPSON LARRY , BRALY PATRICIA
Published: May 2007

SYNOPSIS Leishmania tarentolae cells in brain‐heart infusion medium were partially synchronized in terms of DNA synthesis and cell division by a 10 hour period of inhibition in 200 μg/ml hydroxyurea at 27 C. Nuclear and kinetoplast DNA synthesis commenced immediately upon removal of hydroxyurea, and kinetoplast and nuclear division occurred after about 5 hr. The Index of Synchronization (3) varied from 33‐41%.

A moderate decay of the synchronicity was noted by the 2nd cell cycle. Hydroxyurea was selectively lethal to S‐phase cells.
Identification of Specific Antibodies Prepared Against Purified Immobilization Antigens of Paramecium aurelia
Authors: SINDEN R. E.
Published: May 2007

SYNOPSIS The identity of antibodies prepared against preparations of isolated immobilization antigen protein of Paramecium aurelia has been studied. Antisera were fractionated by ammonium sulfate precipitation, sucrose gradient centrifugation, and ion exchange chromatography on DEAE cellulose. The different fractions were assayed for the presence of specific antibodies by the immobilization test, and the globulins were identified by immuno‐electrophoresis. It is concluded that in the sera studied in this investigation, specific antibodies are excusively of the class Ig G.
The Mechanism of Food Intake in Tokophrya infusionum and Ultrastructural Changes in Food Vacuoles during Digestion*
Authors: RUDZINSKA MARIA A.
Published: May 2007

SYNOPSIS Food intake in Tokophrya infusionum is preceded by penetration of the knob of the tentacle into the cytoplasm of the prey, Tetrahymena. Immediately thereafter, the membrane of the knob starts to invaginate into the lumen of the inner tube of the tentacle carrying with it the cytoplasm of the prey. At the proximal end of the tentacle, the invaginating membrane inflates, pinches off and forms a food vacuole. The mechanism is similar to that in amoebae during pinocytosis. The first few food vacuoles contain broken‐up membranes, an indication that predigestion of prey cytoplasm takes place. This process is limited, however, to the part of cytoplasm around the knob since all food vacuoles formed later are composed of intact cytoplasmic organelles of Tetrahymena. Among them the most abundant and at the same time the most resistant to digestion are mitochondria and mucocysts. The ultrastructure of mitochondria is preserved very well during processing for electron microscopy and changes in their fine structure therefore serve conveniently as markers of the stage of digestion and of the age of food vacuoles. Digestion of mitochondria progresses over a period of several hours. They finally seem to degrade into glycogen‐like particles. All components of the food vacuole reach this stage much earlier. Digestion proceeds further until the food vacuole is filled with a watery content of very low density. Digestion in such food vacuoles is completed. The complete digestion of the content of food vacuoles is of primary importance for Tokophrya, since this organism does not have a cytopyge thru which waste products could be eliminated.
Isolation of Histomonas meleagridis from Embryonated Eggs of Heterakis gallinarum*
Authors: RUFF M. D. , McDOUGALD L. R. , HANSEN M. F.
Published: May 2007

SYNOPSIS. Histomonas meleagridis was isolated from eggs of Heterakis gallinarum by culturing artificially hatched eggs in a modified DeVolt's alkaline serum medium. The presence of the protozoon in the cultures was established by microscopic examination and confirmed by producing histomonosis in turkeys by intracecal inoculation with quantities of the cultures.
Photoassimilation of Glycolate, Glycine and Serine by Euglena gracilis
Authors: MURRAY D. R. , GIOVANELLI† J. , SMILLIE ROBERT M.
Published: May 2007

SYNOPSIS. Glycolate was readily utilized for growth by Euglena gracilis, strain Z, in the light at pH 3.8 under a variety of atmospheric conditions, including CO2‐free air and nitrogen. Glycolate did not support growth in the dark as sole carbon source; no significant uptake of glycolate was observed under these conditions. However, cells grown in the light with glycolate as sole carbon source were still capable of glycolate uptake for up to 3 hr after transfer to darkness, and glycolate was taken up by cells utilizing glucose in the dark. The energy requirement for glycolate utilization could thus be met either by light, or by the aerobic metabolism of glucose in the dark. DCMU, an inhibitor of photosystem II, inhibited photoassimilation of glycolate. In the light, but again not in the dark, glycine and serine also served as sole source of carbon under CO2‐free air, but not under nitrogen. Net release of ammonia to the medium accompanied the photoassimilation of glycine and serine. Of the several metabolicallyrelated compounds tested, only glycolate was utilized as sole carbon source in the light under “anaerobic” conditions. A lag in net chlorophyll synthesis occurred during the photoassimilation of glycolate glycine or serine. Determination of rates of photosynthetic 14CO2 fixation confirmed that some inhibition of photosynthetic capacity had occurred in response to utilization of glycolate and related compounds.
Cyst Wall Protein Synthesis and Some Enzyme Changes on Starvation and Encystment in Colpoda steinii
Authors: TIBBS J. , MARSHALL B. J.
Published: May 2007

SYNOPSIS. During starvation‐induced encystment, Colpoda steinii loses some 30% of its nitrogen before synthesizing a glutamic acid‐rich protein coat, which after 24 hr accounts for 18% of the cyst protein. Settling cells contain 29 ± 2 pg/cell of glutamic acid (free acid plus that released on hydrolysis) whilst encysted cells contain 51 ± 3 pg/cell, the coat glutamic acid being adequate to account for the increase. Thus substantial glutamic acid and protein biosynthesis occur during starvation. Assayed in homogenates, some relevant enzymes appeared to decrease rather than increase in activity as encystment proceeded. Intra‐cellular proteolytic activity showed little alteration but ribonuclease, acid phosphatase, L‐alanine: 2‐oxoglutarate aminotransferase (E.C.2.6.1.2) and L‐glutamate:NAPD oxidoreductase (E.C.1.4.1.4) were considerably reduced. The total carbohydrate content of the cell also increased during starvation.
The Life Cycle of Isospora felis Wenyon, 1923, a Coccidium of the Cat*
Authors: SHAH HARISH L.
Published: May 2007

SYNOPSIS. A pure strain of Isospora felis derived from a single oocyst was used to study the endogenous cycle. One and a half to two‐month‐old laboratory‐reared, coccidia‐free kittens were used thruout the study. The endogenous stages occurred in the epithelial cells of the distal parts of the villi in the ileum and occasionally duodenum and jejunum. All stages lay above the host cell nucleus. There were 3 asexual generations. The 1st generation schizonts were 11–30 by 10–23 μ when mature and contained 16–17 banana‐shaped merozoites 11–15 by 3–5 μ. They became mature in 96 or sometimes in 120 hours. The 1st generation merozoites entered new host cells, rounded up and formed 2nd generation schizonts. These formed within themselves 2–10 or more spindle‐shaped bodies resembling 1st generation merozoites in shape and size. These were 2nd generation merozoites. They were uninucleate 120 hours after inoculation, but by 144 hours they became larger, multinucleate and some lost their elongate shape and became ovoid. They were then 3rd generation schizonts. They were 12–16 by 4–5 μ. Each formed up to 6 or more banana‐shaped merozoites 6–8 by 1–2 μ. The 3rd generation schizonts and merozoites developed within the same host cell and parasitophorous vacuole as the 2nd generation schizonts and merozoites. Mature schizonts containing only 3rd generation merozoites appeared 144 hours after inoculation, were most abundant 168 hours after inoculation, and might be present as late as 216 hours after inoculation. They were 14–36 by 13–22 μ and contained 36 to more than 70 merozoites.

The 3rd generation merozoites entered the sexual cycle. The mature microgametocytes were 24–72 by 18–32 μ and contained a central residuum and a large number of microgametes 5–7 by 0.8 μ with 2 posteriorly‐directed flagella. The mature macrogametes were 16–22 by 8–13 μ. Gametogony occurred 144–216 hours after inoculation.

The prepatent period was 168–192 hours and the patent period 10–11 days. Peak oocyst production occurred on the 6th day of the patent period.
Induction of Competence for Mating in Tetrahymena by Cell‐Free Fluids
Authors: PHILLIPS RUTH BROSI
Published: May 2007

SYNOPSIS. Cell‐free fluid from sexually reactive cultures of Tetrahymena pyriformis, syngen 7 can induce mating in otherwise unreactive mixtures of cells of 2 mating types. Rare individual cells may initiate the production of this substance, but once it is produced, the entire culture becomes sexually reactive.