bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress‐Induced Wall Motion Abnormalities with Low‐Dose Dobutamine Infusion Indicate the Presence of Severe Disease and Vulnerable Myocardium
Authors: Sawada Stephen G. , Safadi Anas , Gaitonde Rajdeep S. , Tung Nisha , Mahenthiran Jothiharan , Gill William , Ghumman Waqas , Gradus‐Pizlo Irmina , Kamalesh Masoor , Fineberg Naomi , Feigenbaum Harvey
Published: May 2007

Background: Patients with left ventricular (LV) systolic dysfunction due to coronary artery disease (CAD) may develop stress‐induced wall motion abnormalities (SWMA) with low‐dose (10 μg/kg/min) dobutamine infusion. The clinical significance of low‐dose SWMA is unknown. Objective: We investigated the clinical, hemodynamic and angiographic correlates of low‐dose SWMA in patients with chronic ischemic LV systolic dysfunction. Methods: Seventy patients with chronic ischemic LV systolic dysfunction who had dobutamine stress echocardiography were studied. Clinical, hemodynamic, and angiographic parameters at rest and low‐dose were compared between 38 patients (mean ejection fraction (EF) of 30 ± 8%) with low‐dose SWMA and 32 patients (EF 30 ± 11%) without low‐dose SWMA. Results: Multivariate analysis showed that the number of coronary territories with severe disease (stenosis ≥70%)(P = 0.001, RR = 6.3) was an independent predictor of low‐dose SWMA. An increasing number of collateral vessels protected patients from low‐dose SWMA (P = 0.011, RR = 0.25). A higher resting heart rate was a negative predictor of low‐dose SWMA (P = 0.015, RR = 0.92) but no other hemodynamic variables were predictors. In the patients with low‐dose SMA, regions with low‐dose SWMA were more likely to be supplied by vessels with severe disease than regions without low‐dose SWMA (92% vs 58%, P < 0.001). Conclusion: In patients with ischemic LV systolic dysfunction, the extent of severe disease and a lower numbers of collaterals predict the occurrence of low‐dose SWMA. Low‐dose SWMA is a highly specific marker for severe disease.
Origin and Morphogenetic Movements of the Pores of the Contractile Vacuoles in Paramecium qurelia
Authors: KING ROBERT L.
Published: May 2007

The position of the contractile vacuoles in non‐dividing Paramecium aurelia, as judged by that of the pores, is relatively constant both laterally and longitudinally, as is the distance between them. Some variability of the distance between the pores persists from the recent fission among the smaller animals of normal shape. At the onset of fission two new vacuoles appear, one anterior to each of the old vacuoles; all the vacuoles must undergo relocation because their mean positions now are somewhat removed from that in the non‐dividing animals. The pores of the front daughter are too close together: the anterior pore is too far back, and the posterior is too far forward; likewise the pores of the hind daughter are too close together: the anterior too far forward as well as the posterior. The relocation does not begin until shortly before separation of the daughters and is practically complete by the time the daughters have assumed their normal length/width ratio after separation. A neuroneme connects the pore to one of the basal granules adjacent to its place of origin, now far removed.

Occasionally more than one new pore appears at the usual time and place during very early fission; these are very close together and usually serve a single vacuole. However, most of them fail to survive the relocation following this and the next fission, so they are found in the posterior position very rarely. But, in some individuals they may survive and serve a single or separate vacuoles. In a certain clone of Paramecium aurelia multiple pores and vacuoles are rather frequent; these are, of course, the result of the tendency to produce multiple pores and vacuoles at the time of fission.
The Effect of Surface‐active Agents on the Permeability, Survival, and Pseudopod Formation of Pelomyxa carolinensis
Authors: NARDONE ROLAND M. , BRAUNGART DALE C. , Sr. HURLEY MAUREEN PERPETUA , Sr. GILSON M. EVANGELISTA
Published: May 2007

SUMMARY. The effect of surface‐active agents on the permeability, survival, and pseudopod formation of the rhizopod, Pelomyxa carolinensis, was studied. Surfactants increased the rate of uptake of Na22 in almost all instances. Tweens which lower surface tension, stimulated or caused pseudopod formation; Tween 80 was the least toxic. The fatty acid component as well as the hydrophile‐lipophile balance of the surfactant may influence the rate.
Mating Type Inheritance at Conjugation in Variety 4 of Parameciurn aurelia*
Authors: Nanney David L.
Published: May 2007

SUMMARY. The pattern of mating type distribution observed at conjugation under different conditions in stock 51, variety 4, of Paramecium aurelia is presented. When the two mating types (VII and VIII) found in this variety are crossed, each pair member usually gives rise to two caryonides of its own mating type. Either parent may, however, give rise to progeny unlike itself. When cytoplasmic fusion is induced by antiserum treatment, the two members of a pair characteristically yield progeny of the same mating type, and the progeny are usually mating type VIII. The direction of change can be influenced to some extent by the temperature at which conjugation occurs; changes from VII to VIII are more frequent at the higher temperatures.

A modification of mating type distribution is observed when conjugation occurs in the unstable clones designated as “selfing caryonides”. Changes are frequent under these circumstances, but are predominantly from type VIII to type VII—precisely the reverse direction observed when pure clones are crossed. The relative frequencies of the changes in the two directions are again influenced by the temperature at which conjugation occurs. These observations indicate a separation of two normally correlated macronuclear functions—the activity in determining the phenotype (mating type) of the cell and the activity in determining the cytoplasmic conditions responsible for nuclear differentiation in the following generation. An interpretation of these results, based on macronuclear heterogeneity, is suggested.
Mating Types in Paramecium multimicronucleatum*
Authors: Giese Arthur C.
Published: May 2007

SUMMARY. The mating behavior of 16 stocks of Paramecium multimicronucleatum from 12 states has been studied. Mating always follows a decline in nutritive conditions. The evidence indicates that there exists one set of four interbreeding mating types. The period of subculture strongly influences the mating reactions, many stocks mating only long after isolation from nature and culture in the laboratory under the restricted conditions employed. Selfing was observed to occur in many races, usually after long periods of subculture. It first occurred in only a small proportion of the population, later in a larger proportion. The similarities and differences between P. multimicronucleatum and other species of protozoa showing multiple mating types are discussed.
The Systematic Position of Pseudomicrothorax dubius, Ciliate with a Unique Combination of Anatomical Features*
Authors: CORLISS JOHN O.
Published: May 2007

SYNOPSIS. The rather rarely found holotrichous ciliate Pseudomicrothorax dubius, generally considered in the most authoritative literature to be a member of the order Trichostomatida, more likely belongs in the Hymenostomatida. Its curious combination of trans‐ordinal characteristics, however, makes difficult exact systematic allocation of it and of the congeneric species P. agilis. The provocative morphological features include: a gymnostome‐like cytopharyngeal “basket”; a tetrahymenal buccal apparatus, with membranelles comparable with those of primitive hymenostomes; an advanced semi‐autonomous type of stomatogenesis; and sensory bristles, flattened rigid form, and restricted ciliature reminiscent of certain spirotrichs. Brief discussion is presented concerning the influence of modern ideas of ciliate classification upon what is considered the proper taxonomic position of the genus.
A Contribution to the Systematics and Morphology of Endoparasitic Trichodinids from Amphibians, with a Proposal of Uniform Specific Characteristics
Authors: LOM JIRI
Published: May 2007

SYNOPSIS. Trichodina urinicola was found in newts, Triturus cristatus and T. taeniatus, in three localities in Czechoslovakia. The ciliate populations showed important differences on the basis of which they were separated as three new forms of this species: T. urinicola f. typica, T. urinicola f. bohemica, both from Triturus cristatus, and T. urinicola f. taeniatus from Triturus taeniatus. The great variability of trichodinids is evident from the literature as well as from our own observations, so that these new forms are to be regarded as provisional ones until it is possible to decide on the basis of a large number of observations the extent of specificity and variation of individual endozoic species of Trichodina. A detailed description of these forms is given as well as a comparison with the known species of trichodinids inhabiting the urinary tract of amphibians. A brief comment on the present taxonomy of the Urceolaridae in general is outlined.

The need for a uniform description of these ciliates is emphasized; in connection with this, the taxonomic value of individual body characters is discussed. Special attention is paid to the adhesive disk of Trichodina, the structure of which is of greatest importance in the taxonomy of this group. On the basis of Dogel's and Fauré‐Fremiet's descriptive methods employed in study of trichodinids, a proposal of a uniform description of Trichodina is made which involves all the important features of these protozoa.
Electron Microscope Studies on Lophomonas striata with Special Reference to the Nature and Position of the Striations*
Authors: BEAMS H. W. , KING R. L. , TAHMISIAN T. N. , DEVINE ROSEMARIE
Published: May 2007

SYNOPSIS.

The flagella of Lophomonas striata are arranged in circular rows in a tuft‐like structure. Each one is continuous with a basal body located in the anterior region of the calyx. Each flagellum is limited by the surface membrane and is composed of nine double peripheral filaments and two central ones. The former continue below the surface and make up a large part of each basal body. Below and parallel to the calyx membrane are two layers of fibrils which appear to connect the basal bodies; the first is just below (250 m/x) the surface, the other is attached to the proximal ends of the basal bodies. Extending from the latter is a delicate network of fibers which gradually disappears from view as it continues in the direction of the nucleus. The calyx membrane appears continuous at the level of the basal bodies; however, below this point it seems to be made up of a series of discrete longitudinally arid obliquely arranged lamina or plates, a condition which permits direct continuity of the cytoplasm within and without the calyx. The body of Lophomonas striata is highly as well as tightly folded in its longitudinal axis and the striations or rods are clearly located on its surface; it is suggested that these are held in place by an agglutination reaction. The rods appear to divide by transverse fission and their fine structure resembles closely that reported for certain bacteria; in fact, because of this, we think they should thus be considered.
Serum Alterations in Avian Malaria*
Authors: SHERMAN IRWIN W. , HULL ROBERT W.
Published: May 2007

SYNOPSIS.

A study by means of paper electrophoresis of the scrum.proteins and lipoproteins during the course of infection of chicks with Plasmodium lophurae, reveals a qualitative change in the gamma‐globulin and demonstrates: a significant crisis period depression of the albumin; no alteration of the alpha‐globulin or alpha‐lipoprotein; a significant crisis period rise in the beta‐ and gamma‐g'obuiins with the former persisting in higher amounts well after the crisis of the infection. The significance of such changes with reference to previous work and the induced pathology is discussed.
An Electron Microscope Study of Food Vacuoles in Paramecium aurelia
Authors: JURAND A.
Published: May 2007

The foed vacuoles of Paramecium aurelia, when examined in the electron microscope, are seen to be surrounded by small secondary vacuoles 0.05 ‐ 0.2 μ. in diameter. Similar small vacuoles also surround the deepest part of the buccal cavity. Young focd vacuoles, i.e. those containing well preserved bacteria, are encircled by a smooth. vacuolar membrane. In older food vacuoles the vacuolar membrane in a transverse section often appears more wavy with small gulfs and protuberances. It is suggested that the small surrounding vacuoles are formed by the vacuolar membrane of older vacuoles by means of a process similar to pinocytosis. There is no evidence, however, that formation of small surrounding vacuoles takes place by pinocytosis in young food vacuoles. Examination of the cytoplasmic membrane of the deepest parts of the buccal cavity shows a similar prccess of vacuole formation by pinocytosis.
The Fine Structure of Lankesterella garnhami
Authors: GARNHAM P. C. C. , BAKER J. R. , BIRD R. G.
Published: May 2007

SYNOPSIS. Thin sections of Lankesterella garnhami were examined by electron microscope and the morphology of trophozoites and sporozoites is described. The envelope of the organism consists of a double membrane, which (in the presumed sporozoite) is broken at one point posteriorly by the microphyle. The anterior end possesses characteristic organelles, which include an open apical ring leading to a collar or conoid and to 30 peripheral fibrils, a paired organelle, and numerous “lankesterellonemes.” Typical mitochondria and a Golgi apparatus are found in the cytoplasm and a nucleus of heterogeneous nature.
Electron Microscope Study of Toxoplasma Cysts in Mouse Brain
Authors: WANKO THEODOR , JACOBS LEON , GAVIN MARY ANN
Published: May 2007

SYNOPSIS. Toxoplasma aggregates in sub‐acutely and chronically infected mouse brain were studied with special regard to interparasitic relationships, encapsulating wall formation and host‐parasite interaction. The individual parasites within a cyst are separated from one another by an opaque substance which also appears as a component of the cyst wall. A second constituent in the wall consists of vesicular and membranous structures which presumably are derived from the endoplasmic reticulum of the host cell. In small cysts, the organising are loosely arranged and maintain the typical crescentic shape whereas, in large cysts, they are tightly packed and polygonal in outline. It is concluded from the data obtained that only the term “cyst” correctly designates these parasitic aggregates.
Catalase in Insect Trypanosomatids*
Authors: WERTLIEB DAVID M. , GUTTMAN HELENE NATHAN
Published: May 2007

SYNOPSIS. Seven monoxenous Trypanosomatidae, Crithidia fasciculata (Anopheles strain), C. fasciculata (Culex pipiens, Wallace), C. fasciculata (Culex pipiens, Nöller), C. luciliae, C. sp. from Euryophthalmus, “Strigomonas” oncopelti and Blastocrithidia culicis all are catalase‐positive. S. oncopelti is only catalase‐positive when grown in hemin‐media. When grown at elevated temperature, C. fasciculata (Anopheles), C. luciliae and S. oncopelti have greater and C. fasciculata (Culex pipiens, Wallace) reduced catalase activity. C. fasciculata (Culex pipiens, Nöller) and C. sp. from Euryophthalmus show reduced catalase activity at elevated temperature that is of borderline significance.

Catalase as a phylogenetic marker is discussed.
Repression of Chloroplast Development in Euglena gracilis by Substrates*
Authors: APP ALVA A. , JAGENDORF ANDRE T.
Published: May 2007

SYNOPSIS. Under “resting” conditions, synthesis of chlorophyll and alkaline fructose‐1,6‐diphosphatase in etiolated Euglena gracilis placed in light was repressed by metabolizable carbon sources. The degree of repression by any carbon source apparently depends on its rate of utilization by Euglena. Thus, pre‐adaptation of Euglena to a specific carbon source, e.g., glucose or ethanol, increased the repression of chloroplast synthesis in the light by that carbon source. Acetate and malate were not as repressive as ethanol. The similarity of this repression to the “glucose effect” is discussed.
Growth and Physiology of Foraminifera in the Laboratory; Part 4 — Monoxenic Culture of an Allogromiid with Notes on its Morphology
Authors: LEE JOHN J. , PIERCE STANLEY
Published: May 2007

SYNOPSIS. A polymorphic allogromiid (our strain NF) was isolated in monoxenic culture but attempts at its axenic culture failed. Growth of monoxenic cultures was stimulated by various metals and vitamins. The morphology and life cycle of this allogromiid with a prominent collar have been studied in detail. It varied in form from ovoid to elongate bioral “Shepheardella‐like” forms and to irregular polyoral organisms. The organisms ranged in length from 56–385 μ (118 μ± 50.54) and in width from 35–385 μ (99 μ± 39.34). The number of nuclei per organism averaged 8.9 ± 6.3 (range 1–40). Reproduction of “Shepheardella‐like” forms was by binary fission. Three types of budding have been observed and, rarely, schizogony. No evidence for sexual reproduction has thus far been seen.
Electron Microscopy of the Ectoplasm and Infraciliature of Spirostomum ambiguum
Authors: FINLEY HAROLD E. , BROWN CHARLES A. , DANIEL WENDELL A.
Published: May 2007

SYNOPSIS. A study of the ectoplasm and infraciliature of Spirostomum ambiguum has been made with light and electron microscopy. Proceeding from the exterior, the cortex is described as the highly structured ectoplasmic portion of Spirostomum consisting of ectoplasmic ridge components and ectoplasmic furrow components. The pellicle invests the ectoplasmic ridges, ectoplasmic furrows, cilia, and adoral membranelles. Electron micrographs show that the cell surface is bounded by two membranes, for the most part parallel. The outer one is continuous with the unit membrane of each cilium; the course of the inner membrane has not been determined in areas bearing cilia.

The ridge components are: (i) a collection of fibrils called peripheral ectomyonemes, situated beneath the inner membrane of the cell surface, oriented parallel with the organism's longitudinal axis and following the peripheral contours of each ridge; (ii) distinct rows of tubular fibrils which form a longitudinal bundle called lateral ectomyonemes, situated in the lower portion of each ridge and oriented parallel to its spiral course; (iii) cytoplasmic matrix suspending and surrounding components (i) and (ii). Mitochondria and unidentified electron‐opaque oval‐shaped or round bodies called X‐bodies are dispersed in the ectoplasmic ridges but they also occur in the endoplasm; therefore, they are considered to be transient inclusions instead of constituents of the ridges.

The furrow components are: (i) the body cilia and adoral membranelles; (ii) the kinetosomes; (iii) root fibrils, called kinetodesmal strands, of the adoral membranelles; (iv) cytoplasmic matrix suspending and surrounding the furrow components.

A trabecular band of randomly oriented filaments, called the endomyoneme is described as possibly the structure called M‐band by Randall and Jackson, 1958, and contractile fibrillar system by Yagiu and Shigenaka, 1963.

It is suggested that collections of distinct fibrils in Spirostomum be called fibrillar complexes. Acceptance of this suggestion will lead to the designation of four distinct fibrillar complexes in heterotrichs; all four complexes have been described or mentioned in previous studies.

Some findings of previous investigators are discussed and confirmed (especially pertaining to Randall and Jackson, also Yagiu and Shigenaka, cited above). Inferences from these independently derived findings are discussed.
Nuclear Behavior of Euplotes woodruffi During Conjugation
Authors: RAO M. V. NARASIMHA
Published: May 2007

SYNOPSIS. During conjugation of E. woodruffi, the micro‐nucleus divides repeatedly four times prior to synkaryon formation and twice thereafter. The first division resembles an ordinary somatic mitosis, resulting in the formation of two daughter nuclei in each conjugant. Both products of this division enter the second division which corresponds to the heterotypic division of other ciliates, characterized by a parachute stage. Following this stage sixteen bivalents appear and separate into dyads and pass to the poles. During the following divisions individualized chromosomes do not appear but only certain chromatin elements comparable to those seen in the somatic and preliminary divisions. These divide and pass to the poles. All daughter nuclei of the second division enter and complete the third division. Only two of the products of the third division enter the final pregamic division while the rest degenerate. Exchange of pronuclei and their fusion leads to synkaryon formation. The conjugants then separate and in each exconjugant the synkaryon divides twice in rapid succession. Of the four products one condenses to become the functional micronucleus, another enlarges rapidly to become the macronuclear anlage while the remaining two degenerate and disintegrate. The old macronucleus breaks into irregular and polymorphic bodies. As the macronuclear anlage enlarges the remnants of the old macronucleus reorganize and fuse with the macronuclear anlage to form a characteristic vegetative macronucleus.
Speciation and Mating Behavior in Eudorina*
Authors: GOLDSTEIN MELVIN
Published: May 2007

SYNOPSIS. A comparative morphological study was made of 73 clones of Eudorina isoated from 44 natural populations and grown under controlled environmental conditions. Utilizing the information obtained in this study in association with the existing taxonomic and experimental literature concerning Eudorina a monographic treatment of the genus was prepared. Nine species and 4 varieties are now recognized.

Sexual compatibility was investigated with 22 heterothallic pairs, 3 male strains and one female strain representing 4 species and one variety of Eudorina. Five partially or completely sexually‐isolated groups were found: 3 groups containing strains of a single species, a fourth group composed of strains of another species, and a fifth group made up of strains of 3 different species. Strains with different zygote arrangements were found generally not to intercross.

Intraspecific crosses indicated that a single pair of alleles controls the inheritance of mating types and that gene flow occurs between strains representing different natural populations. Interspecific crosses resulted in the formation of polyploid or aneuploid F1 offspring which shewed an abnormal segregation of the mating types. Abnormal mating type segregation was also obtained in F2 crosses involving certain of the hybrid polyploid offspring.
Miamiensis avidus n. g., n. sp., a Marine Facultative Parasite in the Ciliate Order Hymenostomatida*
Authors: THOMPSON JESSE C. , MOEWUS LISELOTTE
Published: May 2007

SYNOPSIS. Miamiensis avidus n. g., n. sp., a marine facultative parasite, is described. Morphological studies were made on specimens treated with the Chatton‐Lwoff silver impregnation technique and living material was examined with phase microscopy. Particular attention was given the infraciliature of the buccal apparatus and its importance to generic assignment in the order Hymenostomatida.
The Genus Dactylosoma*
Authors: MANWELL REGINALD D.
Published: May 2007

SYNOPSIS. Dactylosoma is a genus of blood protozoa which undergo schizogony, without producing pigment, in the red cells of the lower vertebrates, especially amphibia. The best known species is D. ranarum, but even for this species the life cycle, except as it occurs in the erythrocyte, and the vector remain unknown. Study of slides from the blood of two species of Formosan frogs, Rana guentheri and R. limnocharis, revealed Dactylosoma ranarum in the former, and what appeared to be a new species, for which the name Dactylosoma taiwanensis is proposed, in the latter. Rana limnocharis has not previously been known to be a host of Dactylosoma, nor has this genus of parasite been reported from Formosa. Dactylosoma ranarum, though not known from many species of frogs and toads, occurs in Asia, Africa, Europe, and in Central and South America. This suggests that it must have been a parasite of Anura for a very long time. Since frogs and toads are incapable of long migrations and are very intolerant of salt water, so wide a distribution may also have palaeogeographic significance.
RNA Synthesis and Cell Division in Heat‐Synchronized Populations of Tetrahymena pyriformis*
Authors: MONER J. G.
Published: May 2007

SYNOPSIS. The incorporation of H3‐uridine during the pretransition period of heat‐synchronized cells of Tetrahymena pyriformis occurs in two peaks, one at 20 and the other at approximately 40 min following the end of the last synchronizing heat treatment (EH). Although Actinomycin D tends to produce substantial inhibition of both peaks it has a significant effect on cell division only if applied before or during the first peak of incorporation. It appears that the production of new RNA is required for the first synchronous division and that it is synchronized with the division process. Actinomycin D seems to increase, slightly, the degree of incorporation of H3‐uridine into RNA when applied at 0 and 10 min past EH. This effect may be correlated with the positive excess delays of division which result when cells are exposed to the inhibitor at these times. A similar effect of Actinomycin on incorporation at 30 or 40 minutes past EH, however, does not appear to be associated with any strong effects of the inhibitor on division.
Influence of Rumen Fluid Source upon Establishment and Cultivation in vitro of the Rumen Protozoon Entodinium
Authors: TOMPKIN R. B. , PURSER D. B. , WEISER H. H.
Published: May 2007

SYNOPSIS. Favorable conditions for establishing Entodinium cultures in vitro were provided by rendering the inoculum almost free of other genera of rumen ciliates, inoculating at a final concentration of 30,000 entodinia per ml, providing 0.2 mg rice starch per ml, but principally by including an appropriate rumen fluid in the media. Rumen fluids collected from animals with high concentrations of entodinia in vivo, in general, were superior in supporting entodinia in vitro than were those collected from animals having low concentrations of entodinia in vivo. Rumen fluids from lambs were improved by clarification (centrifuging at 25,000 ×g for 20 min), but clarification destroyed the ability of rumen fluids from pregnant ewes to support entodinia in vitro. One or more factors occurring in the supernatant portion of pooled, clarified lamb rumen fluid stimulated entodinia in vitro.
Survival of Tetrahymena pyriformis and Paramecium aurelia Following Freezing*
Authors: WANG GUANG‐TSAN , MARQUARDT WILLIAM C.
Published: May 2007

SYNOPSIS. Tetrahymena pyriformis strains E, A‐136 31C and IMT II survived freezing in 10% dimethylsulfoxide when the temperature was lowered to freezing at 4.5 C/min. Survival was then obtained for at least 128 days by lowering the temperature rapidly to 95°C. Of the 3 strains, T. pyriformis IMT II was most resistant to the effects of freezing. Its volume averaged about half that of either of the other strains and may have contributed to the differences in survival. In addition to differences among strains, a medium relatively low in the concentration of nutrients, a culture nearing peak population, and a rate of cooling of 4.5 C/min, all gave best survival. Paramecium aurelia regained motility after being frozen in 6 to 7.5% dimethylsulfoxide for as long as 7 days at either –27 or –196 C, but cultures were obtained only after storage for 20 min at –27 C. A concentration of 6 to 7.5% dimethyl‐sulfoxide, cooling at 4.5 C/min, and culture media containing Aerobacter aerogenes or composed of a commercially available composition were all required for survival of P. aurelia.
An Ultrastructural Study of Ingestion and Digestion in Tetrahymena pyriformis*
Authors: ELLIOTT ALFRED M. , CLEMMONS GRETCHEN L.
Published: May 2007

SYNOPSIS. When the structures involved in digestive events in T. pyriformis are examined at the electron microscope level, some information is added to that long known from light microscopy. The food trapping mechanism consists of the three membranelles, undulating membrane, oral ribs, and a “valve” apparently closing the opening to the cytopharynx. Both of the latter structures are supported by microtubules. Fibers extend internally from the cytopharynx and are closely associated with the food vacuole as it forms.

Clear vacuoles resembling pinocytic vacuoles appear to arise from differentiated areas of the pellicle and plasma membrane. These vacuoles may fuse with primary lysosomes. Hydrolases are thus contributed to the pinocytic vacuoles which may then fuse with food vacuoles. When first formed food vacuoles contain no hydrolases but may acquire them directly, from primary lysosomes or from pinocytic vacuoles. Digestion proceeds to completion in the food vacuole, at which time soluble food products are released to the cytoplasm. Undigested materials are lost through the cytopyge. In stationary growth phase cells autophagic vacuoles form containing mitochondria and other cellular particulates. Such vacuoles probably contain hydrolases when formed and they may receive others by fusion with primary lysosomes.
Metamorphosis from the Phoront to the Trophont in Hyalophysa*
Authors: BRADBURY PHYLLIS CLARKE , TRAGER WILLIAM
Published: May 2007

SYNOPSIS. The nature and sequence of changes involved in the metamorphosis of the phoront of Hyalophysa have been examined in the light microscope using both living and silver‐impregnated ciliates. The phoront's infraciliature, which resembles that of the migratory tomite, differentiates to the trophont (feeding stage) infraciliature without an intervening dedifferentiation. The primary visible event of metamorphosis is the growth of the metastomial area that distorts the meridional somatic kineties so that they curve or spiral around it. The distinct borders and intense argentophilia of the metastomial area suggest that it is a discrete organelle which is probably involved in the management and concentration of a large volume of dilute food. The anterior ventral field of kinetosomes, whose presence distinguishes Hyalophysa from Gymnodinioides, forms from a disorganized anterior segment of falciform field 9.

The rapid and pronounced elongation of the somatic kineties supports our view that the kinetodesmos elongates by the sliding of its component subfibrils upon one another, and that the accessory kinetosomes seen in the electron microscope become functional at metamorphosis. The movement of the kineties and contractile vacuole pore during metamorphosis suggests that differentiation in this instance is not directed by pellicular “fields” but by morphogenetic movements of the underlying cytoplasm.
Cytoplasmic Particles in the Killers of Euplotes minuta and their Relationship to the Killer Substance*
Authors: HECKMANN KLAUS , PREER JOHN R. , STRAETLING WOLF H.
Published: May 2007

SYNOPSIS. The killer strains of Euplotes minuta contain cytoplasmic epsilon particles absent in sensitive strains. The toxic principle of killers is associated with large particles which sediment readily in the centrifuge and may be identical with epsilon. Killing particles are inactivated by heat, certain proteolytic enzymes, and lysis with the French press.
Fine Structure, Reconstruction and Possible Functions of Components of the Cortex of Tetrahymena pyriformis
Authors: ALLEN RICHARD D.
Published: May 2007

SYNOPSIS. Improved methods of preparing cells for electron microscopic study have permitted a more complete examination of the tubular and fibrous elements already reported in the cortex of Tetrahymena pyriformis. Three of these structures, a kinetodesmal fiber, a band of postciliary microtubules and a band of transverse microtubules, are all associated at one of their ends with the proximal end of a basal body‐cilium complex. From this position they radiate out as tho from one corner of a tetrahedron, each passing separately to one of the other 3 corners. Available evidence is presented and discussed for a structural function for these elements. A firm bonding of these fibers and bands to the basal body at one of their ends and to the amorphous material under the pellicle at their other ends is thought to provide for this support. Connecting the proximal ends of the left side of the basal bodies of a kinety is another, previously undescribed, set of tubules. Their diameter, 24 mμ, and cross sectional structure are similar to those of the other microtubules. However, their more sinuous longitudinal appearance, small number of tubules per kinety and different reaction to fixatives suggest a different function. Because of their location it is proposed that they may be a communication line between basal body‐cilium complexes of a kinety. A 3‐dimensional drawing shows the positioning of the above structures in the cortex. Bodies with an internal tubular structure appear anterior to the proximal end of some basal bodies. They are referred to as probasal bodies due to their resemblance to procentrioles; they may be immature basal bodies. Smooth‐membraned cisternae which have bristle‐coated pits and bear a resemblance to the outer pellicular membrane appear in the cytoplasm. Their origin is discussed.
Isospora peromysci n. sp., I. californica n. sp., and I. hastingsi n. sp. (Protozoa: Eimeriidae) from Four Sympatric Species of White‐footed Mice (Peromyscus) in Central California
Authors: DAVIS BETTY S.
Published: May 2007

SYNOPSIS. Isospora peromysci n. sp., I. californica n. sp., and I. hastingsi n. sp. are described from 4 Peromyscus species in Monterey County, Central California. I. peromysci n. sp. was found in 35 of 1,346 Peromyscus, including P. californicus, P. truei, and P. maniculatus; I. californica n. sp. was found in 15 Peromyscus, including P. californicus, P. boylii, P. truei, and P. maniculatus; and I. hastingsi n. sp. was found in one P. truei. Endogenous forms of I. peromysci n. sp. are described from P. maniculatus, and host distribution and incidence of all species are given.
Fine Structure of the Schizont and Merozoite of Isospora sp. (Sporozoa: Eimeriidae) Parasitic in Gehyra variegata (Dumeril and Bibron, 1836) (Reptilia: Gekkonidae)
Authors: SCHMIDT K. , JOHNSTON M. R. L. , STEHBENS W. E.
Published: May 2007

SYNOPSIS. A study was made of the fine structure of some stages in the life cycle of an undesignated species of Isospora parasitic in a gecko. The merozoites which lay within a membrane‐bound periparasitic vacuole in the host epithelial cell, had a striking similarity to Plasmodium, Lankesterella, Toxoplasma, Besnoitia, Sarcocystis, Eimeria and the M‐organism. Each merozoite was invested with a triple‐layered pellicle, the outer membrane of which was loosely applied. At the anterior end of the merozoite were conoid and apical rings; microtubules terminated in the posterior apical ring. Other organelles included nucleus, endoplasmic reticulum, mitochondria, micropyle, paired organelle, toxonemes and a variety of vacuoles. Although the sequence of development of the merozoite was not completely followed, some events in this process were recorded. The evidence suggests that anterior ends are formed early and that merozoites develop subsequently by a process of budding. The merozoite pellicle appears to be continuous with, altho structurally different from, the investing membrane of the parent cell.
The Fine Structure of Rhynchocystis pilosa (Sporozoa, Eugregarinida)
Authors: WARNER FRED D.
Published: May 2007

SYNOPSIS. The trophozoite of Rhynchocystis pilosa obtained from the seminal vesicles of the earthworm Lumbricus terrestris was studied by light and electron microscopy. The trophozoite's cortical organization is particularly interesting because of its unusual evaginations and associated fibrillar structures. The pellicle is formed by 2 concentric membranes elevated into 60–70 alternating primary and secondary ridges extending posteriad. Numerous long ‘hairs’ or cytopilia originate along the primary ridges and each contains a system of fibrils originating from an underlying longitudinal myoneme. Longitudinal rows of pores lie between adjacent pollicular ridges.

Three systems of fibrils lie in the cortex of the trophozoite. A longitudinal myoneme consisting of 12–18 fibrils lies below each primary pellicular ridge. Circular myonemes lie below the pellicle in a parallel array along the length of the organism. Each myoneme consists of 4–8 fibrils structurally similar to those of the longitudinal myonemes. Pairs of fine filaments also lie in the inner pellicular membrane along the apex of each ridge. The trophozoite's anterior end is modified as an attachment organelle consisting of 30–35 delicate pellicular folds which originate at the base of an anterior papilla. The folds extend approximately 15 μ posteriad where they become continuous with the primary pellicular ridges.

The nucleus lies in the cytoplasm near the posterior level of the attachment organelle and is surrounded by a double membrane perforated by numerous pores. The cytoplasm contains numerous small vesicles which may be found in dense aggregations. These aggregations often occur in proximity to Golgi complexes and certain membrane‐bound bodies. Mitochondria are abundant in the cytoplasm as are large, ovoid paraglycogen bodies. Occasionally layers of granular membranes are arranged parallel to the surface of the paraglycogen bodies but also occur thruout the cytoplasm.
The Fine Structure of Microgametogenesis in Haemoproteus columbae Kruse*
Authors: BRADBURY PHYLLIS CLARKE , TRAGER WILLIAM
Published: May 2007

SYNOPSIS. The structural changes leading to the formation of motile microgametes from a single immobile intracellular gametocyte have been examiued in the electron microscope. After pigeon blood infected with Haemoproteus columbae was exposed to the air at room temperature for a few minutes axonemes appeared in the parasite's cytoplasm and the cytoplasm itself appeared less dense. The axonemes were connected with bundles of intranuclear microtubules that were perhaps spindle fibers. No conventional kinetosomes or centrioles have been observed.

After the microgametocyte left the erythrocyte, it assumed the shape of a polarized slug or a dumb‐bell. Half of the organism was surrounded by a single membrane and filled by part of the nucleus. The other half was surrounded by the remains of the multiple membranes of the gametocyte and contained pigment granules, mitochondria, axonemes and nuclear extensions. The axonemes and nuclear extensions were segregated at the periphery of the cell, exterior to the gametocyte's inner membrane, and were assembled in situ into microgametes. The mature microgamete appeared to peel off from the gametocyte, leaving a residual body.
Nuclear Behavior of Spirostomum ambiguum During Conjugation with Special Reference to Macronuclear Development*
Authors: RAO M. V. NARASIMHA
Published: May 2007

SYNOPSIS. During conjugation in Spirostomum ambiguum, the micronuclei divide thrice before synkaryon formation and 20 times thereafter. During the first meiotic division 18‐24 bivalents, each about 0.5 μ or less appear on the spindle. They separate and pass to the poles. The details of the 2nd and 3rd prezygotic divisions and synkaryon formation by reciprocal exchange of gametic nuclei resemble those described for other ciliates in the literature. The synkaryon divides twice resulting in 4 nuclei; 2 of them become micronuclei and the remaining 2 macronuclear anlagen. The micronuclei enter into division, but this division is arrested in metaphase. The chromosomes in the macronuclear anlagen resemble those appearing in the Ist meiotic division in shape and size. In their maximum stage of development the macronuclear chromosomes are at least 3‐4 times larger than those appearing in the arrested micronuclear metaphases in the same cell. There is no banding pattern of the chromosomes and therefore the possible extent of polyteny is difficult to evaluate. The chromosomes duplicate 3‐4 times resulting in about 200–250 before they become indistinct as separate entities. Spirostomum is the only nonhypotrichous ciliate in which these cytologic features are described.
What the Peritrichs Have Taught Us*†
Authors: FINLEY HAROLD E.
Published: May 2007

SYNOPSIS. The peritrichs have taught naturalists, biologists, zoologists, and other kinds of scientists many of their secrets. Consequently, we know many details regarding their gross structure, ultrastructure, ecology, and life history. Their sexual phenomena are rather clearly understood. While general agreement has been attained as regards the forementioned topics, the taxonomic position of peritrichs is still vigorously debated. In this address representative examples of advances in our knowledge of peritrichs will be reviewed … representative instead of all‐inclusive examples. A plea for the restoration of peritrichs to a taxonomic position above spirotrichs will be made. The Society's members will be assured that all protozoologists will have the opportunity to help design a completely International Commission on Protozoology in the International Union of Biological Sciences and they will be assured that such a Commission can and should be planned at the 1969 International Conference in Leningrad.
Algal Flagellate Symbiosis in the Foraminifer Archaias*†
Authors: LEE JOHN J. , ZUCKER WILLIAM
Published: May 2007

SYNOPSIS. A symbiotic alga from the foraminifer Archaias angulatus was isolated axenically. Algae from crushed hosts were coccoid and highly vacuolated; division stages within an envelope were common. Biflagellate motile piriform organisms predominated in newly transferred cultures and were gradually replaced by the coccoid, highly vacuolated stage. Incorporation of 14C label in intact Archaias was greatest for organisms fed and incubated in light. Starved symbiotized organisms incubated in the light incorporated ∼30% as much label as fed counterparts, There was no obvious difference in 45Ca incorporation between fed and starved organisms. Light significantly enhanced calcification. The Archaias symbiont infected Rosalina leei but not Quinqueloculina spp.
Differentiation and Multiplication of Dyskinetoplastic Trypanosoma cruzi in Tissue Culture and in the Mammalian Host*
Authors: DEANE MARIA P. , KLOETZEL JUDITH K.
Published: May 2007

SYNOPSIS. In cultures of the Y strain of Trypanosoma cruzi treated with acriflavine, a very high proportion of the crithidiae may be dyskinetoplastic. These crithidiae cannot be maintained in subcultures but are able to differentiate into (dyskinetoplastic) metatrypanosomes. In tissue cultures infected with these metatrypanosomes, or with blood trypanosomes and treated with acriflavine, dyskinetoplastic T. cruzi is able to go thru the whole sequence of stages that characterizes its cycle in the vertebrate host: penetration by trypanosomes into cells, differentiation into leishmaniae, multiplication in this phase and differentiation again into trypanosomes. The same may occur in the mammalian host itself. The physiological implications of these findings are discussed and special attention is called to polymorphism of blood forms of T. cruzi, which probably has the same significance it has in the brucei‐evansi group of trypanosomes.
Etude Ultrastructurale des Mérozoites et de la Schizogonie des Coccidies (Eimeriina): Eimeria magna (Perard 1925) de I'Intestin des Lapins et E. tenella (Railliet et Lucet, 1891) des Coecums des Poulets
Authors: SENAUD JEAN , ÇERNÁ ZOFIE
Published: May 2007

SYNOPSIS. An electron microscopic study is made of merozoites and schizogony of Eimeria magna and Eimeria tenella from rabbits and chickens infected 5 days before fixation.

The merozoite outer layer is formed by a unit membrane lined by a dense osmiophilic layer. A micropyle is present. The apical complex of the cell is constituted by a conoid surmounted by 2 rings and surrounded by another from which about 26 subpellicular, tubular fibrils start. Two “rhoptries” (= toxonemes) go thru the conoid to the apex of cell. Rare sarconemes (= convoluted tubes) are disseminated in the anterior part of merozoites. A nucleus with nucleolus, Golgi apparatus, mitochondria, endoplasmic reticulum, lipid globules and glucidic grains were observed.

Schizogony starts by the formation of a multinucleated schizont which has a centriolar structure. The new merozoites appear as evaginations of the schizont's membrane. Cellular organelles (conoid, rhoptries, micropyle, sarconemes) differentiate and the nuclei enter the diverticula of the schizont. Then the development of merozoites proceeds by “external budding”.

The ultrastructural similarities between the merozoites of Eimeria and the endodyocytes of Toxoplasmea, appear to us to be extremely interesting and indicate a close relationship between the Toxoplasmea and the Coccidia.
Fine Structure of Peridinium westii Lemm., a Freshwater Dinoflagellate
Authors: MESSER GLENDA , BEN‐SHAUL Y.
Published: May 2007

SYNOPSIS. The fine structure of Peridinium westii Lemm., an armoured dinoflagellate collected from Lake Tiberias, is reported. Thick cell walls contain plates, pores and tubules, and are surrounded by an external membrane. The cytoplasm is limited by 3 membranes. Nuclei contain numerous chromosomes with a fibrillar organization. The chloroplast envelope consists of 3 membranes; parallel lamellae, each generally comprising 3 thylakoids, are present. Pyrenoids are present in various forms within the chloroplast structure. Trichocysts are found in cells both as elongate dense cores within a membrane‐enclosed sac and as striated rods. An eyespot is found in a plastid containing several thylakoids.
Structure of Hypotrichomonas acosta (Moskowitz) (Monocercomonadidae, Trichomonadida) as Revealed by Electron Microscopy*
Authors: MATTERN CARL F. T. , DANIEL WENDELL A. , HONIGBERG B. M.
Published: May 2007

SYNOPSIS. The fine structure of Hypotrichomonas acosta resembles in many respects that of Trichomonadidae, and especially of members of the sub‐family Trichomonadinae which have been examined to date by electron microscopy. In addition, the flagellate has certain ultrastructural differences from the latter organisms, some of which are of phylogenetic significance. Among these, the structure of the undulating membrane and the apparently occasional presence of a fine filament which may be considered as homologous to the costa of Trichomonadidae are the most important. The undulating membrane is represented by a rather low and otherwise poorly developed dorsal cytoplasmic fold with an ill‐defined distal marginal lamella; the recurrent flagellum is applied near the dorsum of the fold. In a very few preparations a relatively short filament, of a diameter falling below the resolution limits of light microscope, is seen in a position which corresponds to that of the costa of Trichomonadidae. The identity of the filament as a probable rudimentary costa is supported also by the character of its periodicity. The rare appearance of the rudimentary costa among hundreds of sections may be explained either by its minute dimensions or by its absence from many hypotrichomonads. Other structures recorded for the first time in trichomonads are: the fine filamentous connections of the axostylar microtubules; the branching of parabasal filament 2; and the unusually organized, perhaps helical, polysomes, which are found in addition to the ribosomal complexes associated with the endoplasmic reticulum and commonly found in trichomonads. A detailed analysis of interconnections among various mastigont structures is presented and several kinds of cytoplasmic inclusions are described. H. acosta is of interest in the study of the nuclear envelope and presence of nuclear pores, which are numerous and conspicuous in this flagellate.

The fine structure of the hypotrichomonad is discussed in relation to that of other trichomonads and in some instances to that of other protozoa.