bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stomatogenesis and Formation of Cirri in Fragments of Oxytricha fallax Stein
Authors: HASHIMOTO KANEJI 
Published: May 2007

Of fragments involving a partial removal of the original adoral zone of membranelles (AZM), the monomacro‐nucleate ones become reorganized monostomes resulting from a simple fusion of the remnant AZM to the oral primordium induced, and the binucleate ones become dividers by initiation of the oral primordium posteriorly from the posterior terminal of the remnant AZM. The cirral primordium in any fragment arises alongside its corresponding oral area. Weisz's idea of the dominance and inhibition of the original oral system extending over the oral primordium site is applicable in stomatogenesis of the present species. This application is found also in cirral formation.In fragments from early stage dividers, a formed oral primordium is easily absorbed by influence of the intact original AZM. This event also occurs after complete removal of the AZM. Such results led to the hypothesis that the oral primordium in the normal divider may be formed under some stoma‐togenic activation of the AZM followed by escape from inhibition also arising from the same source. Irrevocable furrow formation and irreversibility of the oral primordium in stomatogenesis occur in later stages of division. Nevertheless division in these stages is blocked when certain operations are performed, forming monsters possessing the AZM of the opisthe translocated to the side opposite to that of the proter. In other monsters obtained from a fusion of the AZM of the proter to that of the opisthe, division occurs belatedly, prior to which secondary oral and cirral primordia are produced.
Electron Microscope Studies of Reproducing and Interkinetic Toxoplasma
Authors: GAVIN MARY ANN , WANKO THEODOR , JACOBS LEON 
Published: May 2007

SYNOPSIS. The reproduction of Toxoplasma gondii has been investigated in osmium fixed and sedimented mouse peritoneal exudate. The material was obtained 9 days after intraperitoneal inoculation with the Beverley strain. Predominantly intracellular organisms were seen in various phases of multiplication and indicated the occurrence of three different modes of reproduction. One is a schizogonic cycle, whereby at least four progenies are delineated within a rosette‐shaped, multinucleated Toxoplasma cell. They subsequently separate to become individual parasites. The second mode is considered as a special type of schizogony that results in the production of only two merozoites within one parent cell. This process previously has been designated as endodyogeny. Finally, the observations suggest division by binary fission as a third type of reproduction.From these results, it is possible to relate the genus Toxoplasma, previously regarded as a protozoon of uncertain classification, to the class Sporozoa.
Observations on the Life‐cycle of a New Race of Blepharisma undulans from India
Authors: SESHACHAR B. R. , BHANDARY A. VASANTHI 
Published: May 2007

SYNOPSIS. A full account of the nuclear changes during binary fission and conjugation in a local race of Blepharisma is presented in this paper. The macronucleus consists of 2 nodes connected by a strand. Number of micronuclei varies from 6 to 18. During binary fission, condensation of macronucleus is followed by elongation and thinning of the middle region which finally breaks. Daughter nuclei later attain the typical vegetative form. Notably, during binary fission some micronuclei appear to complete their mitoses by the time the macronucleus attains the condensed form, while others lag behind and exhibit practically every stage of mitosis.During conjugation, from 6 to 10 micronuclei undergo the first pregamic division, the same number through the second division, and two products of the second division take part in the third division. The rest degenerate. Division products of the nuclei in the paraoral region take part in synkaryon formation. The synkaryon undergoes either 2 or 3 divisions. In the former case, of the 4 products, 2 become the macronuclear anlagen, one the micronucleus and the fourth degenerates. In the latter case, of the 8 products, 3 to 4 become the macronuclear anlagen and the rest become micronuclei. Chromatin elimination has been observed during the division of the macronuclear anlage, followed by an extra metagamic fission of the cell.Comparison with two other races from India and an American race indicates considerable diversity in the structure and behaviour of the nuclear apparatus in different races of Blepharisma undulans.
Exogenous Factors Affecting Respiration in Tetrahymena pyriformis*
Authors: McCASHLAND B. W. , KRONSCHNABEL J. M. 
Published: May 2007

SYNOPSIS. Respiration of Tetrahymena pyriformis W, grown in Proteose peptone‐glucose medium, was determined by Warburg's direct and indirect methods. The Qo2 varied inversely with cell concentration under exogenous conditions (cells in conditioned medium, i.e., one which had supported growth) as determined by both methods, and under endogenous conditions (washed cells suspended in salts solution) when determined by the indirect method. Endogenous respiration, measured by the direct method, was low but independent of cell concentration.Respiration, determined by the direct method, was little affected by lowered O2 availability, but varied directly with nutrient availability. The inhibitor, malonate, which also stimulates respiration at greater dilutions, inhibited respiration at 10−2M when present with low cell concentrations, but stimulated at high cell concentrations.The reduced respiration at higher cell concentrations is thought less due to lack of O2 than to CO2 accumulation and competition for nutrients. Consideration of these variables is essential in comparing data from the literature.
The Plastid System of Normal and Bleached Euglena gracilis*
Authors: GIBOR AHARON , GRANICK S. 
Published: May 2007

SYNOPSIS. The plastid system of “normal”Euglena gracilis strain Z was found to be extremely unstable. Under normal culture conditions in the light about 1 or 2% of the cells were found to have lost spontaneously the capacity to green on further culturing. Cells treated with streptomycin, heat or U.V. all lost the capacity to green on further culturing. Bleached cells whether appearing spontaneously or by induction with streptomycin, heat, or U.V. light, were all found to possess within them organelles which were identified as proplastids.The proplastids of some “bleached” strains were capable of synthesizing porphyrins when grown in a standard culture medium. Others synthesized porphyrins only after the addition of delta‐aminolevulinic acid to their medium, while proplastids of still other strains could not synthesize porphyrins from this precursor. Normal cells when grown in total darkness were found to possess proplastids morphologically identical with those of the bleached strains. Upon exposure to light the proplastids enlarged and greened. In cells which grew under continuous light the plastid system appeared as an interconnected system of tubules. Cells maintained on a schedule of 12‐hour light and 12‐hour dark had plastids which were detached from each other.
Taxonomy of Genus Blepharisma with Special Reference to Blepharisma undulans
Authors: BHANDARY A. VASANTHI 
Published: May 2007

SYNOPSIS. Three new species of Blepharisma are presented: B. seshachari sp. nov., B. intermedium sp. nov., and B. tropicum sp. nov. Two sub‐species of Suzuki are elevated to specific rank, B. undulans americanum to B. americanum and B. undulans japonicum Suzuki to B. japonicum Suzuki. Stein's taxa for the species Blepharisma undulans are considered to be diagnostic for that species.Important features of morphology and life‐cycle of the above mentioned species are given. Discussion and position of the species Blepharisma undulans are presented and a proposal for the reorganization of the species is made. The possibility of a new key derived from a hypothesis of the phylogeny on an evolutionary basis of the genus is presented. This hypothesis has been extended to include ciliates like Stentor and Spirostomum and its implications discussed.
Evolutionary and Systematic Relationships in the Flagellate Order Trichomonadida Kirby*
Authors: HONIGBERG B. M. 
Published: May 2007

SYNOPSIS. Discussion of the systematic relationships and of the evolutionary trends among the 4 families, Monocerco‐monadidae, Devescovinidae, Calonymphidae, and Trichomonadidae of the order Trichomonadida includes a consideration of 8 subfamilies, 3 of them new. The genera of Devescovinidae and Calonymphidae, all of which are limited in their distribution to lower termites, are not considered; those of Monocercomonadidae and Trichomonadidae are discussed in the light of the information pertaining to their structure, morphogenesis, distribution, and host‐parasite relationship. Diagnoses are given for 6 subfamilies and 14 genera belonging to the latter two families, which are diagnosed also. Type genera are designated for each family and subfamily that is discussed, and type species are designated for each of the 14 genera. A complete synonymy is presented for each type species. Two new species, one of Monocercomonas and another of Tritrichomonas are named and diagnosed.The paper includes a key to all the families and subfamilies of the order and to the genera of Monocercomonadidae and Trichomonadidae.
The Mode of Action of Certain 3‐ and 5‐Nitropyridines and Pyrimidines. IV. Development of Drug‐Resistance by Trichomonas vaginalis.
Authors: MICHAELS RHODA M. , TREICK RONALD W. 
Published: May 2007

SYNOPSIS. Certain 5‐nitropyridines and pyrimidines are growth inhibitory to Trichomonas vaginalis in vitro. Populations were made resistant either to 2‐amino‐5‐nitropyrimidine, or 2‐amino‐5‐nitropyridine, or 2‐hydroxy‐5‐nitropyridine, by growth in gradually increasing concentrations of one of these inhibitors. After resistance was maximal, clonal lines were established. The development of resistance to any one of these inhibitors was accompanied by resistance to the other two. Since cross‐resistance was complete, these inhibitors act at the same locus. This in vitro resistance persisted in vivo.Resistance was accompanied by an increase in the generation time and a decrease in the maximal obtainable population. These growth parameters were unique for each resistant clone. The growth of the clone made resistant to 2‐amino‐5‐nitropyridine was the closest to the normal clone. Its metabolic capacity, as measured by conventional Warburg techniques, was less than half of the parent strain and anaerobically was the same as had been previously found for non‐resistant cells which had been grown for 3 hr with inhibitor. The mechanisms of killing by the inhibitor and the development of drug resistance are the same. The inhibitor kills the cells by holding them in an early metabolic sequence. Some of them succeed in growing by using this metabolic sequence and reinforcing it with an alternate aerobic route.
A Wilt of Coffea liberica in Surinam and its Association with a Flagellate, Phytomonas leptovasorum Stahel
Authors: VERMEULEN H. 
Published: May 2007

SYNOPSIS. A description is given of a disease of Coffea liberica Bull ex Hiern. occurring in Surinam, British Guiana and, according to previous investigations by Stahel, also in Brazil, San Salvador, and Colombia. The symptoms and spreading of the disease are described and its relation to a fungus disease of coffee with very similar wilting symptoms. Special attention has been paid to the concurrence of the observed flagellate Phytomonas leptovasorum Stahel and the multiple division of the phloem vessels on account of the scepticism with which Stahel's discovery of the flagellates in sieve tubes of wilting coffee trees was met by other research workers.Moreover a short description is given of experiments to transmit the disease to healthy coffee trees by grafting, with special reference to the successful root grafting. Furthermore it could be ascertained that no viruses or nematodes are involved as pathogens. The possible relation between the disease and insects is still unsettled; observations of flagellates in the midgut of certain bugs, found on the roots of coffee trees, seem to indicate that the vector of the phloem necrosis disease is a Hemipteran insect.Although no final proof of the pathogenicity of the flagellate can be given, secondary indications support the theory that the flagellate Phytomonas leptovasorum is the cause of the phloem necrosis disease of Coffea liberica in Surinam.
An Electron Microscope Study of the Amoebo‐flagellate, Naegleria gruberi (Schardinger). I. The Amoeboid and Flagellate Stages*
Authors: SCHUSTER FREDERICK 
Published: May 2007

SYNOPSIS. Axenic and monobacterial cultures were utilized to study the ultrastructure of the amoeboid and flagellate stages in the life‐cycle of Naegleria gruberi. The cytoplasm of the amoeboid stage is poor in electron‐dense components; a loosely organized endoplasmic reticulum is present. The absence of cytoplasmic inclusions in the ectoplasm is the only detectable difference between it and the endoplasm. The nucleus of Naegleria is typically vesicular. The mitochondria are of the type commonly found in protozoa. Food and contractile vacuoles are described. No Golgi apparatus has been found.The general ultrastructure of the flagellate resembles that of the amoeba. The kinetic apparatus consists of flagella and their associated kinetosomes, a “spur” made up of isodiametric fibrils (14 mμ in diameter) attaching to the base of the kinetosome, a cross‐striated rhizoplast, and thin‐walled fibrils (22 mμ in diameter) with a center of attachment in the kinetosomal complex.Neither centrioles nor kinetosomes have been found in the amoeba. Complex arrangements of endoplasmic reticulum have been seen in the cytoplasm of transforming individuals which may be points of origin of the kinetosomes and/or flagella. The nuclei in metamorphosing individuals frequently show unusual plasticity.Some speculations on possible orgins and affinities of Naegleria are included.
Influence of Enzymes on Germination of Sporocysts Of the Gregarine Pyxinia crystalligera Frenzel*
Authors: KOZLOFF EUGENE N. , BROWN HAROLD E. 
Published: May 2007

SYNOPSIS. Sporocysts of P. crystalligera readily germinate to permit escape of their sporozoites when placed in an infusion of the contents and the tissue of the midgut of the beetle host, Dermestes vulpinus. To determine the type of digestive enzyme required for germination to take place, sporocysts were exposed in hanging drops to 0.25% (w/v) concentrations of commercial preparations of trypsin and lipase in a saline solution. Sodium taurocholate was used in combination with certain of the enzyme preparations.Up to 99% of the sporocysts exposed to trypsin 1:300 and to a relatively crude preparation of lipase (containing some trypsin) germinated within three hours. A refined preparation of trypsin (2 × crystallized, salt‐free) induced up to 65% of the sporocysts to germinate within three hours. Refined lipase (50μl CO2/mg/30 min.) had no germinating effect upon sporocysts, either by itself or in combination with sodium taurocholate. In mixtures, crystallized trypsin seemed definitely to be inhibited by sodium taurocholate, and perhaps was inhibited also by refined lipase.The fact that trypsin is effective in causing germination to take place suggests that the germination of sporocysts in the digestive tract of D. vulpinus depends upon a proteolytic enzyme. Unlike trypsin, which was more active in solutions adjusted to an initial pH of 7.0 and 8.0 (especially the latter, in the case of crystallized trypsin) than in those of pH 6.0, this enzyme was more effective in inducing germination at pH values of 6.0 and 7.0.
Adaptations in Growth and Division inEuglenaEffected by Energy Supply*
Authors: COOK J. R. 
Published: May 2007

SYNOPSIS.Euglena gracilis(strain Z) was grown auto‐trophically at different light intensities, saturating or limiting for cell division. Adaptation to culture at each light intensity was gauged from division rate, mass, protein, photosynthetic pigments, nucleic acids, volume, paramylum, lipids, respiration, and photosynthesis. Illumination above 1200 foot‐, candles was saturating for all aspects of cell growth; the highest intensity examined (3,000 ft‐c) slightly inhibited cell division. Intensities between 400 and 1200 ft‐c were saturating for all except photosynthesis and paramylum accumulation. Intensities less than about 200 ft‐c became limiting for all fractions except protein, which remained constant over the range 120–3000 ft‐c, dropping, however, at 65 ft‐c. Concentration of photosynthetic pigments increased as light intensity decreased.Absolute synthetic rates were estimated for the individualEuglenacell for the measured cell constituents. While most followed a predictable pattern, increasing with light intensity to saturating levels, the synthetic rates for the pigments went through maxima at 190 ft‐c. Since fixed carbon in limiting light is so apportioned that protein is synthesized to the exclusion of paramylum, one concludes that the energy requirements for cell growth (measured as protein synthesis), and to a lesser extent cell division, have a higher priority than do those activities concerned more directly with maintenance.
Protozoa as Toxicological Tools*
Authors: Hutner S. H. 
Published: May 2007

At the age of 50 a Puka‐Pukan retires from manual labor and becomes one of the members of The Company, spending hi; evenings shooting popguns or playing checkers, and his nights in ordering the young fry about. He never again has to go fishing, to gather coconuts, or to do any other work.When the malos [young men] bring in their fish they are given to the fathers, who divide them after picking out the choice bits for themselves… To be sure, many of the fathers spend a day or two at fishing now and then, but this is not required of them and they do it only to pass the time… (22).
The Fine Structure of Leishmania donovani and the Role of the Kinetoplast in the Leishmania‐Leptomonad Transformation*
Authors: RUDZINSKA MARIA A. , D'ALESANDRO PHILIP A. , TRAGER WILLIAM 
Published: May 2007

SYNOPSIS. An electron microscope study of Leishmania donovani revealed major differences between the intracellular leishmanial and the extracellular leptomonad stages. Parasites were also removed from infected hamster spleen, inoculated into cultures, and examined at intervals during incubation in order to follow changes during the transformation from one stage to the other. Prominent changes are evident primarily in the kinetoplast and the nucleoli after several hours of cultivation when the parasite is in an intermediate stage of transition. The kinetoplast, a composite organelk containing DNA and cristae mitochondriales, is a regular, sausage‐like structure in the leishmanial stage, but becomes irregular and enlarges extensively after a few hours in vitro, developing branches that are mitochondrial in nature and which, very likely, become new mitochondria. In the nucleus, significant nucleolar changes occur. The two homogeneous nucleoli characteristic of the leishmanial stage merge during transformation into one which is larger, less compact, and composed of small centrally located granules about 100 Å in diameter and larger particles over 200 Å in diameter at the periphery. These transformations of the kinetoplast and nucleolus are undoubtedly expressions of adaptive changes in the metabolic pattern of an intracellular parasite transferred to a markedly different extracellular environment of much lower temperature.It was also found that the leishmanial stage of the parasite has two unit membranes which extend over the flagellum and the flagellar pocket; the intermediate stage and the leptomonad have only a single membrane. Furthermore, some leishmanias in spleen cells were found to be covered by a capsule‐like structure formed by the deposition of fine granular material between the two unit membranes. Since two to four organisms were occasionally found within such capsules, it is possible that encapsulation is a preparatory step for reproduction.
Lizard Malaria in Georgia*
Authors: JORDAN HELEN B. 
Published: May 2007

SYNOPSIS. South of latitude 32°, where adequate samples were taken, both Sceloporus undulatus and Anolis carolinensis were infected with Plasmodium fioridense Thompson and Huff, but with varying frequency. Data resulting from general surveys made in two coastal islands, Jekyll and Sapelo, and from 11 counties in south and southwest Georgia showed 62 of 1,325 or 4.7% of Sceloporus and 106 of 846 or 13% of Anolis to be positive for P. fioridense. The Fargo‐Okefenokee Swamp Area, including Echols and Clinch Counties, was designated as a special study area during the period of 1959–1963, during which time monthly collections of lizards and mosquitoes were made for transmission experiments. In this area, 104 of 2,232 or 4.7% of Sceloporus and 510 of 1,502 or 34% of Anolis were positive for P. fioridense. During the first 3 years (1959–1961), the rate of infection in Anolis was about 46% as compared to 6% in Sceloporus from the same area during the same period. In 1962 the frequency of occurrence in Anolis dropped to 24% (85 of 358) and in Sceloporus to 3.3% (15 of 448). In 1963 there was a further drop to 17% in Anolis (60 of 353) and to 2% in Sceloporus (11 of 514). Thus the incidence was from 3 to 10 times higher in Anolis than in Sceloporus in this area. There is a marked increase in new infections in Anolis during late summer and fall indicating a period of parasite transmission.Local mosquitoes, Aëdes atlanticus‐tormentor, A. triseriatus, Psorophora confinnis, P. ferox and Mansonia perturbans, fed on infected lizards and kept at 25–30°C, were all negative. One of 80 Aëdes aegypti showed 1 oocyst and negative salivary glands. Four of 70 Culex territans had 23, 1, 16 and 2 oocysts, but negative glands 31 days following an infective blood meal from Sceloporus. Culex quinquefasciatus (225 dissected) had 2 infections of 1 and 3 oöcysts and negative glands. One of 3 Culex sp. had 70 oocysts and negative glands. No transmission experiments were successful. Under the conditions of testing, when Anolis and Sceloporus were exposed to mosquitoes at the same time, mosquitoes preferred to teed on Sceloporus.
Cultivation of the Peritrich Telotrochidium henneguyi in Axenic and Non‐Axenic Media*
Authors: FINLEY HAROLD E. , McLAUGHLIN DAVID 
Published: May 2007

SYNOPSIS. Telotrochidium henneguyi was cultured axenically. The major nutrients in medium T‐3 were liver extract (1:20 National Biochemicals Co.), hydrolyzed yeast nucleic acid, glucose, and dl‐β‐hydroxybutyric acid; these were fortified with phosphate buffer, EDTA, and penicillin. The supplements were: 18 amino acids, 7 vitamins, 10 salts supplying trace‐metals; uridylic, cytidylic, guanylic, and adenylic acids; thymidine‐5‐diphosphate, nicotinamide mononucleotide, and choline. Optimum conditions for axenic cultivation were obtained with phosphate buffer 2 × 10−1M, penicillin 5,000 U.S.P. units/ml, 23°C, pH 6.8. A monoxenic maintenance medium (“T‐broth”) allowed prolific growth and produced trxmendous populations. It was composed of Bacillus cereus in an aqueous broth‐concoction of Proteose‐peptone, Cerophyl, and wheat kernels. Axenic T‐3 medium supported serial subculture; yields of peritrichs were comparable to those in T‐broth. Axenic yields were poorer in medium lacking the T‐3 supplemenits but containing the major nutrients fortified with acid‐hydrolyzed gelatin, serine, riboflavin, EDTA, CaCL, FeCI3, KCI, MgSO4·7 H2O, phosphate buffer, and penicillin. For rapid axenination, excystment was induced by vibrating encysted peritrichs ∼ 30 sec in a Vortex Jr. mixer. Freshly excysted animals were washed by centrifugation. A salt solution, not distilled water, was used for washing inoculants. Inocula consisting of 1 × 103 or more animals were obtained by conventional centrifuge methods.Extension of this investigation to construction of a chemically defined medium is discussed.