ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb04356.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Six strains of amoebae isolated from freshwater habitats and having broad, flattened locomotive forms were studied in clonal cultures, with attention to trophic structure, nuclear division, cyst structure in those strains which formed cysts, some aspects of cytochemistry, and other characteristics.Three strains were found to belong to the genusFlabellula, one being identified asF. platypodia(Gläser, 1912) and the other 2 asF. miraSchaeffer, 1926. The new speciesRugipes placidusis described. One strain, identified as belonging to the species originally calledAmoeba actinophoraAuerbach, 1855, is re‐described asHyalodiscus actinophorus, and a similar strain is described asH. actinophorusvar.minorn. var.All 3 strains ofFlabellulahad the unusual type of mitotic figure reported by Gläser forF. platypodiabut not previously studied with the Feulgen technic. The genusRugipeshas the mitotic pattern more common to small amoebae and is distinguished fromFlabellulapartly on that basis. Both strains ofHyalodiscushave division figures of this common type.Of the strains included in this investigation, onlyR. placidusandH. actinophorusformed cysts in culture. The cysts of neither species were viable after one year at room temperature and humidity.The status ofRugipesas distinct fromFlabellulais discussed. The genusHyalodiscusis interpreted in a manner compatible with the original definition of Hertwig and Lesser and is included within the order Amoebida. The strains of this genus isolated have a doubly contoured, strongly PAS‐positive covering over the endoplasmic hump.Some criteria for the taxonomy of amoebae are evaluated in the light of work reported in this and 2 previous p

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02084.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Trophozoites ofGiardia murisparasitic in hamsters were fixedin situat intervals of 1–3 hr after injection of horse ferritin into the small intestinal lumen. Concentrations of ferritin molecules are localized within vacuoles beneath the plasmalemma along the dorsal and ventral surfaces ofGiardia.Limiting membranes of these vacuoles are identical with the plasmalemma. It is suggested that the vacuoles function in sequestration of molecules from the intestinal lumen by invagination of the cell membran

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02085.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Administration of dexamethasone to rats infected withTrypanosoma lewisiresulted in the development of exceedingly large populations of trypanosomes which were fatal to their hosts. The elevated levels of parasitemia in treated rats early in infections were thought not to be a result of an increased reproductive rate. However, trypanosomes in treated rats 2 days postinfection did have a higher coefficient of variation in total length and a greater percentage of dividing forms than those observed from infected rats which were not given the drug. The course of infection may be markedly altered not only in intensity but also in length by this corticosteroid. It is suggested that dexamethasone administered at the levels recorded to rats infected withT. lewisiinhibits the production of ablastin and trypanocidal antibodies.

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02086.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Monkey kidney cells (LLC‐MK2) grown in flasks and on coverslips in Leighton tubes were used as host cells for the growth of the intracellular stage, Leishman‐Donovan bodies (LDs), ofLeishmania donovaniobtained from hamster spleen. These parasitized cultures were then used to determine the ability of acriflavin to induce dyskinetoplastic LDs.LD‐infected cells were somewhat fewer in number than uninfected cells at all times except for the 1st day after infection. The parasites attained their maximum numbers on the 5th day after infection of the cultures having a 1.9‐fold increase at that time.When acriflavin was added to the cell culture medium (250 mμ/ml) the numbers of monkey kidney cells did not differ greatly from non‐treated cultures until 6–7 days after treatment with acriflavin. Similarly, the numbers of LDs in acriflavin‐treated cell cultures, altho somewhat below those of untreated cultures, did not differ greatly from them.The combined effect of acriflavin and LDs reduced the numbers of monkey kidney cells in treated, LD‐infected cell cultures more than either alone.Dyskinetoplastic LDs appeared in considerable numbers in acriflavin‐treated, LD‐infected cell cultures. Dyskinetoplastic and normal LDs harvested from cell cultures were inoculated into NIH medium and incubated at 27 C for transformation into leptomonads. There was no indication that dyskinetoplastic LDs were capable of transform

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02087.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.The conclusion drawn in 1921 that the large nuclei in the cytoplasmic cortex ofGlugeacysts are not vegetative nuclei of the microsporidan but nuclei of the hypertrophied host cell was based on the discovery of early developmental stages in the mesenchyme of stickleback larvae experimentally fedGlugeaspores. This observation had been made on serial sections from experiments done in 1912. The intracellular development of the microsporidan could be followed up in this material only thru the 1st stages of schizogony. Renewed infection experiments, done still in 1921 on a much broader basis, have fully confirmed the previous findings, as briefly stated in 1922. On this material, the intracellular development ofG. anomalahas been followed up in recent years from uninucleate host cells 7 μ in diameter, interpreted as wandering cells in the mesenchyme, until they became macroscopic multinucleate cysts, in which schizogony and sporogony of the microsporidan produced innumerable vegetative stages and spores ofGlugea.The details of the developmental processes are described in the present paper.The multinucleate host cell and the intracellular parasites together form one of the symbiotic complexes for which the term “xenom” or “xenoma” has been used by me since 1949. By a sequence of amitotic nuclear divisions, the uninucleate host cell in theGlugeaxenomas ofGasterosteusbecomes plurinucleate in contrast to the usual structure of other xenomas of fish.Already in 1921, I thought that the host cell in theGlugeaxenomas may have phagocytic properties. The observation of accumulation of granules from pigment cells in some of theGlugeaxenomas has now verified this sup

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02088.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.Eimeria eumoposn. sp. (Coccidiida, Eimeriidae) from a Colombian batEumops trumbulli(Chiroptera, Molossidae) is described. This is the first recorded coccidium in a bat from the western hemisphere, and the sixth bat coccidium species described to date. The unsporulated oocysts in the bat feces are 30.9–24.0 by 28.9–23.2 μ (near 28.8 × 26.1 μ). Their outstanding feature is the pronounced pitting of the thick brownish oocys

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02089.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.The trophozoite ofRhynchocystis pilosaobtained from the seminal vesicles of the earthwormLumbricus terrestriswas 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’ orcytopiliaoriginate 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

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02090.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.An electron microscope study ofPlasmodium coatneyiin the rhesus monkey supplied information on the fine structure of trophozoites, gametocytes and of the host cell. The trophozoites resemble other mammalian malaria parasites. They do not have typical protozoan mitochondria, but instead a concentric double‐membraned organelle, which, it is assumed, performs mitochondrial functions. They feed on the host cell by pinocytosis, engulfing droplets of erythrocytes thru invaginations of the plasma membranes at any region of the cell or thru the cytostome. Digestion of hemoglobin takes place in small vesicles pinched off from the food vacuole proper.Gametocytes can be clearly distinguished into macro‐ and microgametocytes. Macrogametocytes are covered by 2 plasma membranes, the inner one appearing thicker in some places. The cytoplasm is filled with Palade's particles and has numerous vesicles of endoplasmic reticulum and toxonemes. In microgametocytes most of the inner membrane is thickened, the cytoplasm has few Palade's particles and vesicles of the endoplasmic reticulum and does not have toxonemes.Erythrocytes with trophozoites are irregularly scallop‐shaped and have elevated points with knob‐like protrusions covered by a double membrane. If these protrusions are sticky they might be in part responsible for clumping and arresting the schizonts and segmenters in the capillaries. The host cell contains numerous Maurer's clefts which in some instances are continuous with the membranes of the parasite suggesting that they might originate fr

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02091.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

SYNOPSIS.The filiform microgamete ofHaemoproteus columbaeconsists of an elongate double‐walled nucleus paralleled by 2 axonemes embedded in a homogeneous matrix. At one end of the gamete, the axonemes are sharply flexed back on themselves, but no conventional kinetosome has been recognized. No mitochondria have been seen. Single‐walled vesicles occur in the matrix, and the entire gamete is surrounded by a single membrane.The large round macrogamete has a conspicuous central nucleus with its outer membrane drawn out into anastomosing evaginations which extend to the periphery of the cell. A moderately electron dense material fills the space between the 2 nuclear membranes and the lumina of the evaginations. Nucleolar material may occur in scattered masses within the nucleus. One or 2 axonemes appear to arise endogenously next to the nuclear membrane.The cytoplasm is filled with ribosomes and perhaps glycogen granules. Typical protozoan mitochondria and vesicles containing pigment retained from the erythrocytic stage are found in the peripheral cytoplasm. Accumulations of dense‐walled vesicles occur in the cytoplasm in conjunction with evaginations of the nuclear membrane. Amid these vesicles triple‐ringed discs resembling the cytostomes of merozoites are frequently seen.Several distinct layers of dense material surround the micro

ISSN:0022-3921    

DOI:10.1111/j.1550-7408.1968.tb02092.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY