bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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.
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.
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.
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.
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.
Storage Polysaccharide in Coccidial Sporozites after Excystation and Penetration of Cells
Authors: VETTERLING JOHN M. , DORAN DAVID J. 
Published: May 2007

SYNOPSIS. Eimeria acervulina, E. necatrix, and E. meleagrimitis sporozoites were examined for carbohydrates by cytochemical methods during dormancy, after excystation, and after penetration of cells. The only carbohydrate found was amylopectin, a homogeneous polymer of glucose. It was distributed in 3 regions: (a) in front of the anterior refractile globule, (b) around the nucleus, and (c) behind the posterior refractile globule. The relative amounts decreased after excystation and penetration of cells until only small amounts remained around the nucleus. The quantity of amylopectin decreased following excystation from 30.0‐36.7 to 9.4‐13.3 μg glucose/106 oocysts. Over a 6 yr period of storage at 4 C, there was a decrease in the quantity of amylopectin in dormant sporozoites of E. acervulina from 33.3 μg glucose/106 oocysts at 3 mos to 1.5 μg at 6 years. Coincidentally, 3 month‐ and 1 year‐old oocysts of E. acervulina produced patent infections in chicks with a dosage of 5 × 104 oocysts, but only a few of the oocysts that had been stored for 2 years were infective; a dosage of 2 × 106 oocysts was necessary to produce a patent infection. Oocysts which had been stored 6 years did not produce a patent infection.It was concluded that amylopectin is the energy source for excystation and subsequent penetration of cells. Small amounts of amylopectin are used during dormancy and, when the content in the sporozoite falls below a certain level, the sporozoites lack sufficient energy to infect cells.
Action of Nitrofuran Derivatives on the Chloroplast System of Euglena gracilis: Effect of Light
Authors: McCALLA D. R. , REUVERS ANTOON 
Published: May 2007

SYNOPSIS. When cultures of Euglena are exposed to nitro‐furantoin in the light, there is extensive bleaching and, at higher concentrations, killing. In the dark the same concentrations have essentially no effect. The enhanced activity in light is a consequence of the rapid photolysis of nitrofurantoin to yield 5‐nitro‐2‐furaldehyde which is, in turn, destroyed by light. Nitrofuraldehyde and several other nitrofuran derivatives bleach at low concentrations in the dark.Of 14 nitrofuran derivatives tested, only 4 Schiff's bases which were readily decomposed to nitrofuraldehyde in light were more active in the light than in the dark.
Fine Structure of the Contractile Vacuole Pore in Paramecium*
Authors: McKAN JAMES A. 
Published: May 2007

SYNOPSISThe pore through which a Paramecium contractile vacuole communicates with the external environment is a 1.2 μm long and 1 μm diameter cylindrical orifice in the pellicle. During diastole, the vacuole:pore junction is closed by a substantial diaphragm which parts to the side at systole. The diaphragm is composed of inner and outer membranes continuous with the vacuole and pore membranes, respectively, and an intervening cytoplasmic layer containing filaments and irregular membranous tubules and vesicles. Microtubules, organized into 2 sets, are an important component of the pore apparatus. One set of ∼ 16 microtubules forms an annulus around the pore. These microtubules are organized into a right‐handed helix with a pitch of 0.5‐0.6 μm, and thus complete slightly more than 2 turns in their course from the level of the diaphragm to the pore outer lip. They appear to be embedded in a layer of dense material immediately adjacent to the pore membrane. The other set consists of 5 or more bands of 10–20 microtubules which radiate in a slight left‐handed helix from an insertion at the pore out over the vacuole surface to the ampullae.
Electrophoretic Characterization of Classical Tetrahymena pyriformis Strains*
Authors: BORDEN D. , WHITT G. S. , NANNEY D. L. 
Published: May 2007

SYNOPSISThe electrophoretic mobility patterns of 8 enzymes have been examined in 43 classical strains of Tetrahymena pyriformis. The strains may be assorted into sets on the basis of a high degree of similarity of their mobility patterns. Strains of similar designation are frequently in different sets, whereas differently labeled strains may be in the same set. It is proposed that new strain designations be made on the basis of phenotypic similarity.
Contractility and its Control in Peritrich Ciliates*†
Authors: ALLEN RICHARD D. 
Published: May 2007

SYNOPSISA review of the recent literature on the structure and physico‐chemical properties of the myoneme and its specialization, the spasmoneme, of peritrich ciliates was made. Myonemes are composed of tightly packed bundles of 3–5 nm microfibrils which parallel, more or less, the long axis of the bundle and are of indefinite length. The presence of contractility in these ciliates is correlated with the presence of myonemes. Associated with the microfibrils is a system of membrane‐bound tubules and saccules continuous with the endoplasmic reticulum (ER). This system is known to accumulate calcium. Myonemes differ from muscles in their structure, solubility properties, birefringence pattern, and in the time during the contraction‐relaxation cycle at which they require energy. They may be related more closely to the cytochalasin B‐sensitive microfibrils of higher organisms than to muscles. Contraction of extracted stalks can be induced solely by raising the calcium ion concentration above a certain threshold. Thus the calcium‐accumulating myoneme‐associated ER would appear to play an important role in the control of myoneme contractility. A specialization at the interface between the myoneme and the ER membranes is described as it appears in Vorticella and Opercularia. This structure, called a linkage complex, is found both in the body myonemes and the spasmoneme and links the membranes of the ER to the microfibrils. It also has microfilaments that pass from the ER‐myoneme interface to the surface membranes. The uniqueness of this structure and its location suggests that it may play a role in controlling the movements of calcium between the ER and myoneme and also in transmission of messages from the pellicular membranes, possibly the alveolar sacs, to the ER.