bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition and Reversal of Oxygen Poisoning in Paramecium*
Authors: Wittner Murray 
Published: May 2007

SUMMARY. Paramecium caudatum exposed to 120 lbs./in.2 (gsi) gauge pressure (g.p.) at 27°C. died in 2 hours 32 ± 15 minutes. Under similar conditions with the addition of 0.04 m pyruvate and 8 × 10‐3 m Mg++ they lived at least twice as long. Substitution of Co++ or Mn++ for Mg++ provided slightly less protection.Addition of sulfhydryl (SH) reagents to paramecia exposed for 2 hours to 120 psi (g.p.) oxygen resulted in reversal of oxygen poisoning. By means of these reagents oxygen poisoning could be reversed indefinitely. It now appears that direct evidence has been obtained to show that oxygen poisoning is a result of SH inactivation. The extent of the poisoning depends upon the rate of oxidation of SH groups by the oxygen as opposed to the rate at which the organism can reduce oxidized and/or furnish new SH groups.
Adaptive Changes in the Acetate Metabolism of Euglena*
Authors: Danforth William F. , Wilson Barry W. 
Published: May 2007

SUMMARY. The acetate metabolism of Euglena grown on ethanol at pH 3.5 (Et‐grown) differs from that of the same strain grown on acetate at pH 7.3 (Ac‐grown) in several respects. Et‐grown cells have a rate of acetate oxidation at pH 7.0 lower than that of Ac‐grown cells. The rate of acetate oxidation by Et‐grown cells is markedly increased at low pH, whereas that of Ac‐grown cells is relatively independent of pH. At pH 5.5, the respiratory rate of Et‐grown cells can be increased by increasing acetate concentrations up to 18.4 IBM, whereas that of Ac‐grown cells is independent of acetate concentration above 4 mM. At pH 7.0, both types of cell are unaffected by changes in acetate concentration above 4 mM.Et‐grown cells incubated in the presence of acetate for about 80 minutes frequently adapt to acetate, taking on characteristics similar to those of Ac‐grown cells.
The Binary Fission of Lacrymaria olor (O.F.M., 1786).
Authors: Bovee Eugene C. 
Published: May 2007

SUMMARY. Observations on binary fission of Lacrymaria olor show that it is a transverse fission. It involves probable intranuclear division of the micronucleus. Both micro‐ and macronucleus elongate in preliminary stages. Each is ultimately divided as cytoplasmic constriction cuts the spindle fibers of the former, and the connecting, nucleoplasmic thread of the latter.Surging movements of cytoplasm after fission elongate the daughter organisms and move new nuclei to normal, central sites. The anterior proboscis of the posterior daughter regenerates suddenly, complete with coronal cilia. Metachronal waves along ciliary meridians, strongly reversed on the posterior daughter, cause an oscillating movement which pulls the two apart, except for a slender, pellicular thread, ultimately severed. Until broken, this thread connects the rear tip of the anterior animal to the forward end of the proboscis of the posterior one. The organism is semi‐quiescent, with proboscis retracted (except spasmodically) throughout fission. After fission the anterior animal quickly begins feeding movements and soon swims away. The posterior animal requires about half an hour before being able to begin feeding and swimming movements.The anterior contractile vacuole of the original animal becomes the primarily active vacuole of the anterior daughter; the posterior one that of the posterior daughter. Missing vacuoles are regenerated by the daughters in about one hour after fission. The division process requires about one hour for completion at 22.4°C.
A Redescription of the Holotrichous Ciliate Pseudomicrothorax dubius with Particular Attention to its Morphogenesis*
Authors: THOMPSON JESSE C. , CORLISS JOHN O. 
Published: May 2007

SYNOPSIS. Pseudomicrothorax dubius, a rather rare protozoon assigned by Kahl to the trichostome order of ciliates, has been found and positively identified for the first time in America, and its morphology and morphogenesis have been studied in detail with the aid of modern techniques. The Chatton‐Lwoff silver impregnation method is considered indispensable in acquiring an understanding of the ciliate's infraciliature: both its anatomy in the mature vegetative animal and its activities during the morphogenetics of binary fission.Stomatogenesis is of a complex type, considered here as “semi‐autonomous” in nature, although a single, true stomatogenous meridian also is involved. Details of this explicit morphogenetic phenomenon are offered.The presence of a true zone of three adoral membranelles, never before recognized with any accuracy in this ciliate, a buccal cavity and associated structures, and the mode of stomatogenesis have led the writers to propose transfer of the genus Pseudomicrothorax from the Trichostomatida to the order Hymenostomatida.
Some Observations on the Morphology and Division of Balantidium coli and Balantidium caviae (?)
Authors: KRASCHENINNIKOW SERHIJ , WENRICH D. H. 
Published: May 2007

SYNOPSIS. Studies of the body ciliature of Balantidium coli and B. caviae (?) after Breslau's opal‐blue and Klein's silver nitrate techniques revealed a preoral‐dorsal suture area where some of the ciliary rows fail to reach the peristomial margin. The incomplete kineties ranged up to a dozen in number and were variable in arrangement. In a count of 100 specimens of B. caviae (?) the incomplete kineties were at the right of the suture in 39, at the left in 24 and on both sides of the suture line in 37. At the posterior end not many kineties reach the pole but no sutural pattern was seen in that region. Scattered irregularities in the ciliary rows were sometimes seen.Studies of the oral region tend to confirm the view of Fauré‐Fremiet that the peristomial ciliature consists of short rows of cilia which are continuations of the anterior body kineties. Membranelles were not found. Thus, some species of Balantidium, at least, show affinities with the Holotricha in agreement with Nie and Fauré‐Fremiet.Fission commonly produces two equal‐sized daughters but many cases of unequal division were observed. In both these species conjugants are much smaller than vegetative animals and two preconjugant divisions are indicated, the first of which may be unequal.During the early stages of fission, the anterior ends of the kineties of the posterior daughter change direction, becoming oblique in the fission zone. In this region the kinetosomes multiply; possibly some of the kineties also divide but evidence for this is incomplete. No evidence of reorganization at the anterior end of the anterior daughter was seen.Attempts to infect hamsters with B. coli and B. caviae (?) failed. No parasites were found in two collared peccaries repeatedly examined.
Serological Types among Thirty‐one Strains of the Ciliated Protozoan Tetrahymena pyriformis*
Authors: LOEFER JOHN B. , OWEN RAY D. , CHRISTENSEN ELEANOR 
Published: May 2007

SYNOPSIS. Unabsorbed, complement‐inactivated antisera produced in rabbits were used in an immobilization system to study the serology of 31 strains of Tetrahymena pyriformis grown in axenic cultures at 26°C. Fourteen serological “groups” were found: 1. “H”: H, E, S, GC, L3, W, T, GHH, G1‐R and sublines W‐P and T‐P; 2. “PR”: PR; 3. “GL”: GL; 4. “LR”: LR; 5. “L1”: L1 and L2; 6. “GP”: GP and Ch‐S; 7. “WH”: WH6, WH14 and WH52; 8. “N”: N and HS; 9. “Y”: Y and TC; 10. “AA”: AA1, AA2 and AA4; 11. “F”: F and BF; 12. “Gf‐J”: Gf‐J; 13. “EZ”: EZ; 14. “Lava”: Lava. Not all of these “groups” were completely distinct; weak or variable cross‐reactions occurring for particular cultures and antisera during the course of several years of observation suggested a relationship in terms of serotype potentialities, for strains in groups 1 and 2, and in groups 2, 3, 4, 5, and 6. Non‐reciprocal cross‐reactions are tentatively explained in terms of population fluctuations of serotype within particular cultures; several other suggested explanations remain possible. On the whole, however, the strains remained remarkably stable in dominant serotype.Observations on Tetrahymena in paralyzing antisera, with respect to the extrusion of a gelatinous exudate, in general confirmed previous observations by others. “Chain” formation was noted upon recovery, under conditions suggesting that the chains do not always derive entirely from incomplete cytokinesis of dividing organisms but that at least sometimes an aggregation of separate individuals is also involved. Synchronized division was observed for recovering organisms. A gelatinous material was obtained by centrifugation of a large number of individuals; this material provided a degree of protection to the organisms against antiserum effects while other colloidal materials did not, but the protective effects proved nonspecific in the sense that they were not confined to particular strain‐antiserum combinations.
A Note on the Transmission of a Nuttallia of Meriones shawi by the Tick Rhipicephalus secundus*
Authors: FELDMAN‐MUHSAM B. 
Published: May 2007

SYNOPSIS. The Nuttallia of the gerbil is transmitted by Rhipicephalus secundus only if the infected meal is taken by the larva, and the subsequent nymphal stage is the only one which is able to infect. There is no transovarial transmission.Infective trophozoites remain in the larval caeca for about 12 hours after gorging. The infective nymph is able to give rise to new infections at various times after it has been allowed to feed, but never later than the third day after disengagement from the host.
A Quarter Century Exploring Tetrahymena*
Authors: ELLIOTT ALFRED M. 
Published: May 2007

SYNOPSIS. In reviewing 25 years of work on Tetrahymena, the author describes early difficulties experienced by himself and others in developing a chemically‐defined medium and in defining the taxonomy of T. pyriformis. With identification of its essential requirements, a variety of nutritional studies revealed the close resemblance between the metabolic pathways of this ciliate and those of the chick and rat. This suggested studies on the effects of gamma radiation and the effect of antibiotics.Attention then turned to the puzzle of the absence of conjugation in all strains of T. pyriformis then maintained in laboratories. The observation that these strains were all amicronucleate led to the discovery of mating types (with D. F. Gruchy). This brought up the problem of what constitutes a species and how it might be solved in T. pyriformis where clearly defined groups are set off from other similar groups (varieties) by a breeding barrier.Another problem is whether a life cycle exists in this ciliate and if so, the role amicronucleate strains play in this cycle.The origin and obvious evolutionary success of these “genetically dead” strains are other problems that are considered.The search for nutritional markers for genetic experiments inspired large‐scale collections, including some from tropical habitats. Strains were found which differed in serine and pyridoxine requirements. Genetic analysis was hindered by the high lethality following conjugation, unsatisfactory mating behavior in some clones, and the complete absence of autogamy, the latter making it difficult to obtain homozygous clones. The use of x‐radiation yielded haploid individuals; when these were mated with diploid clones the resulting haploid progeny proved that the genes controlling mating type and pyridoxine synthesis resided in the micronucleus.Genetic analysis of the serine and pyridoxine mutants supports the idea that T. pyriformis is more of an outbreeder than an inbreeder. Left for the future is an extension of our knowledge of the breeding system of T. pyriformis and ultimately to examine critically the factors responsible for the success of this ubiquitous ciliate.
Flagellate Parasites of the Fly, Phaenicia sericata (Meigen)*
Authors: WALLACE F. G. , CLARK TRUMAN B. 
Published: May 2007

SYNOPSIS. Two species of flagellate parasites, Herpetomonas muscarum (Leidy 1856) Kent 1881 and Crithidia luciliae (Strickland 1911) have been isolated in pure culture from the fly, Phaenicia sericata. Laboratory‐reared Musca domestica were infected with each of the species. These two species have often been confused, the latter being regarded as “cysts” of the former. H. muscarum is long and slender and occurs actively swimming in the midgut of the host. C. luciliae is short and truncate and occurs mainly in the hindgut where it is often attached to the gut wall.C. luciliae grows readily and abundantly in culture and outgrows H. muscarum in mixed cultures. Attempts to infect Aedes aegypti and Culex pipiens with C. luciliae failed while control feedings of these mosquitoes with Crithidia fasciculata produced infections.
Abnormal Infraciliatures of Balantidium coli and B. caviae (?) and Some Morphological Observations on These Species*
Authors: KRASCHENINNIKOW SERHIJ 
Published: May 2007

SYNOPSIS. Balantidium coli was cultured for 4 months in Dobell‐Laidlaw's medium. About 10 specimens of monsters were found in the preparations (Chatton‐Lwoff silver impregnation technique). One individual showed a tendency to polystomy. One doublet of Balantidium caviae (?) in preparations treated by the same technique was found in a population from a guinea pig.The monsters of Balantidium coli are either single distomic individuals or doublets (homopolar or heteropolar).The infraciliature of the monsters shows different degrees of deviation from the normal pattern. No reorganization field during the formation of additional cytostomes was observed, which agrees with the data on normal stomatogenesis. This process is very similar in both normal specimens and monsters and is characterized by the arrangement of radiating kineties surrounding the anlage of the cytostome and, evidently, by invagination of this area which later forms the peristome. The fate of single monsters and that of homopelar doublets is unknown. The heteropolar monsters are considered non‐viable because the arrangement of the kineties in both presumptive daughters contradicts the rule of desmodexy (Chatton‐Lwoff).The occurrence of the monsters in cultures may possibly be explained by the action of acriflavine which is mutagenic for Escherichia coli, or by gentian‐violet which inhibits fission of sea urchin eggs.This paper apparently constitutes the first presentation of anomalies of the infraciliature in parasitic ciliates.In addition the exact arrangement of the kineties and kinetosomes at the posterior pole of Balantidium coli is described.
Effects of pH and Viscosity on Surface Membranes in Paramecium multimicronucleatum
Authors: LEE J. WARREN , McCALL WILLIAM 
Published: May 2007

SYNOPSIS. Paramecium multimicronucleatum was grown in a buffered desiccated lettuce medium maintained at pH 7.5, with Aerobacter aerogenes the main bacterial source. The maximum expansion in length and width was at pH 6.0; the minimum expansion in length and width at pH 8.5. The paramecia were usually stouter at pH levels < 7.0 except at pH 5.5 and generally more slender > pH 7.0.The pH of the medium affected the size of food vacuoles as indicated by the fact that the maximum food vacuolar diameter was at pH 6.0, the minimum at 7.0.The fastest and greatest expansion of food vacuole diam. was at a relative viscosity of 8; the minimum food vacuolar diam. was in controls (without gum arabic) having a viscosity of 1.3.
Effects of Some Metabolic Inhibitors on the Pigments of Euglena gracilis in an Acidic Medium
Authors: GREENBLATT CHARLES L. , SHARPLESS NORMAN E. 
Published: May 2007

SYNOPSIS. Darkness and O2‐lack promote formation of a pheophytin‐like pigment from chlorophyll in Euglena gracilis in an acidic medium. Dinitrophenol (DNP) produces similar but more drastic pigment alterations in aerated and illuminated cells. The extent of pigment decay was dependent on DNP concentration and external pH. Since volume expansion and inhibition of the contractile vacuole were also noted, it is suggested that pheophytin formation is secondary to hydrogen ion influx from the external medium. Major structural alterations of the chloroplast accompanied the pigment changes.Pentachlorophenol, iodoacetamide, Na fluoride, and Na azide produced similar pigment changes. Malonic acid and fluoroacetate were ineffective under the conditions described. However, in the dark, cells treated with fluoroacetate formed pheophytin rapidly. These effects are discussed in relation to the maintenance of intracellular [H+].
Mating Types and their Determination in Stylonychia putrina*
Authors: DOWNS L. E. 
Published: May 2007

SYNOPSIS. A total of 155 clones of Stylonychia putrina collected in nature were tested for mating type. Two sexually isolated varieties were found among them: Variety I with 12 mating types and Var. II with 11. Five of the clones isolated in the laboratory belonged to 3 additional mating types of Var. I making a total of 15 mating types in this variety.Crosses were made among 6 of the mating types of Var. I, and 114 clones of progeny were raised and tested for mating type. No simple genetic explanation of the results was evident.An abnormal type of conjugation with fusion of the conjugants and subsequent fission was studied. Both parental mating types sometimes segregated during the first two fissions of a fused animal. Mating type determination in the progeny of the fused animals seemed to parallel that of the progeny of the normal conjugants in that in both cases certain mating types tended to be dominant over others.
Nuclear Division in Pelomyxa illinoisensis Kudo*
Authors: McCLELLAN J. FORBES 
Published: May 2007

SYNOPSIS. Pelomyxa illinoisensis exhibits several phenomena of an interesting and uncommon nature, such as the presence of polar granules and the appearance of chromosomes through most of the resting and dividing stages of the nucleus. For these reasons and because of the importance of the nucleus as a stable characteristic in the taxonomy of amoebae, this study of the nucleus and nuclear division was undertaken.Culture methods were the same as those used for P. carolinensis. Best fixatives for nuclei were Carnoy, Flemming, 10% formalin, Duboscq‐Brazil, Schaudinn and 2% osmium tetroxide. The body shape of P. illinoisensis in nuclear division is correlated with the stage of nuclear division and resembles the same stages in Amoeba proteus and P. carolinensis, with the exception of a ragged appearance of the cytoplasm of organisms containing prophase nuclei and the halo‐like appearance of the pseudopods in those containing metaphase nuclei. The condensation of resting nuclei when subjected to acidified methyl green, reported by Kudo (18), occurred with all fixatives used with the exception of 10% formalin and 2% osmium tetroxide. The metaphase nuclei have a disk of polar granules on either side of the equatorial plate with fibers running from them to the chromosomes. The nature of these granules is unknown. Similarities and differences between P. illinoisensis and P. carolinensis are discussed.
Electron Microscope Observations on Malarial Oocysts (Plasmodium cathemerium)*
Authors: DUNCAN DONALD , EADES JAMES , JULIAN S. R. , MICKS DON 
Published: May 2007

SYNOPSIS.Thin sections of Plasmodium, cathemerium obtained 3 to 10 days after ingestion of blood by mosquitoes were examined by electron microscopy. Oocysts are encased in a relatively thick structureless capsule which becomes progressively thinner with advancing age and completely disappears in places at the time of release of the sporozoites. The capsule blends with and in most cases cannot be distinguished from the “elastic” layer of the mosquito stomach. For this reason the capsule is tentatively regarded as a product of the host rather than of the parasite. Capsular material appears to be shed into the interior of the oocyst and may serve as nutrient material in the later stages of development. Oöcysts and sporozoites contain mitochondria, endoplasmic reticulum and nuclei with nucleoli at all stages examined.All limiting membranes within the oocyst are feebly developed and no cell boundaries are seen until the sporozoites begin to form. At this stage, the sporozoites acquire very prominent surface membranes which are retained by the mature forms.Sporozoites contain long rods and cylinders of homogeneous material of moderate density. Their functional significance is not understood.
Morphogenesis in the Ciliate Bresslaua vorax Kahl and the Phylogeny of the Colpodidae*
Authors: STOUT J. D. 
Published: May 2007

SYNOPSIS.Bresslaua vorax is a dimorphic ciliate with micro‐stome and macrostome forms. The development of the macro‐stome form is associated with pronounced extension of the vestibule and vestibular opening and gross torsion of the ciliate which finally shows little resemblance to the microstome form. These transformations culminate a phylogenetic trend in the Colpodidae which can be followed from the ciliates of relatively simple structure, such as Woodruffia, through Bryophrya, Colpoda and Tillina to Bresslaua. This phylogenetic trend is marked by the increasing importance of stomatogenesis. The morphogenetic pattern of these transformations appears to distinguish the Colpodidae from other trichostomatous ciliates, such as the Plagiopylidae.
Volume, Nucleic Acid and Nitrogen Contents of Strains of Green and i Colorless Englena gracilis and of Astasia longa*
Authors: NEFF RUTH H. 
Published: May 2007

SYNOPSIS.Nucleic acid, the nitrogen content per cell, and cell and nuclear volume were determined in 4 green and 2 heat‐induced colorless strains of Euglena gracilis and one strain of Astasia longa. All strains of Euglena were identical in cell and nuclear volume. The deoxyribonucleic acid content per cell of the apoplastidic strains was higher than that of the corresponding green strains by I1/, times. Although their nuclei were not enlarged, Feulgen staining of the colorless strains was also more intense. The significance of the increase in DNA in experimentally induced apoplastidy is discussed. As for N total nucleic acid P, and pentosenucleic acid—the dir between the strains reflected previously established morphological and physiological relationships between them. The single strain of Astasia studied was identical in stru: and size with the apoplastidic Euglena stnMH Hownner. it was quite unlike them in all the biochemical characteristic; examined.
Flagella Formation by Myxamoebae of the True Slime Mold. Didymium nigripes*
Authors: KERR NORMAN S. 
Published: May 2007

SYNOPSIS.For development of flagella by myxamoebae of the true slime mold, Didymium nigripes, optimal results were obtained when they were incubated in 0.05 M NaHCOa (pH 9.1). Streptomycin inhibited flagella formation in pH 6.2 phosphate buffer but had no effect in NaHC03. The time necessary for 50% of the population of myxamoebae to become flagellated was independent of the concentration of myxamoebae; hence, the morphogenesis probably follows first‐order kinetics. The acquisition of flagella was divisible into 4 stages by means of time‐lapse cinephotomicroscopy: an ameboid stage, a stage of morphogenesis, an ameboid‐flagellate stage, and a free‐swimming flagellate stage. At least 90% of the population developed flagella within 60 min. under optimal conditions. The flagellar apparatus consists of a long and a short flagellum, each arising from a granule in the blepharo‐plast. The blepharoplast is connected to the nucleus by a rhizoplast.