(1) This ability may be associated with virulence, because an attenuated strain of L. pneumophila fails to multiply within this protozoan, whereas a virulent strain increases 10,000-fold in number when coincubated with T. pyriformis.
(2) Upon incubation with fluoresceinylated neoglycoproteins, isolated macronuclei from the ciliated protozoan Euplotes eurystomus display different labelling patterns depending on the nature of the sugar bound to the neoglycoproteins.
(3) It is suggested that this early immune maturity may play a role in the hardiness of WAD goats and in their relative resistance to helminth and protozoan infection as compared with local sheep.
(4) We compared the molecular nature of the rat brain opiate receptor with that of the invertebrate leech, Haemopis marmorata, and the protozoan, Tetrahymena, in order to examine the issue of apparent receptor heterogeneity with respect to biochemical structure.
(5) The protozoan parasite Trypanosoma cruzi is able to replicate in the cytoplasm of primary resident macrophages, but is killed by activated macrophages.
(6) Axenic H. vermiformis strain CDC-19 has been deposited with the American Type Culture Collection (ATCC 50237) and should prove useful in the study of protozoan-bacterial interaction.
(7) No cross reactions were observed in sera immune to other protozoan, helmintic and bacterial infections, although some cross reactivity was seen in P. falciparum immune sera.
(8) Alveolar macrophages from the 3 groups of subjects had similar limited microbicidal ability for the obligate intracellular protozoan, Toxoplasma gondii, and similar numbers of elastase receptors and affinity for elastase.
(9) DNA-dependent RNA polymerase from blood forms and culture forms of the parasitic protozoan Trypanosoma brucei was resolved into multiple peaks of activity by DEAE-Sephadex chromatography.
(10) A list is provided of the naturally or experimentally Aedes aegypti transmitted arboviruses (103), protozoans (5) and filaria (20).
(11) A 50% inhibition of the biosynthesis of dihydrosterculate is observed in the presence of 4 microM 10-thiastearate in the protozoan growth medium, but little effect is seen on the distribution of the other fatty acids.
(12) Protozoan species abundance was reduced to less than half by Zn but was unaffected by snails.
(13) Its presence in Giardia is consistent with the view that ARF emerged before the divergence of this protozoan from other eukaryotes (approximately 1.5 billion years ago), and that an ARF-like protein may have been the ancestor of several other classes of signal-transducing guanine nucleotide-binding proteins, including the alpha subunits of the heterotrimeric G proteins.
(14) We have found that the anaerobic protozoan parasite Giardia lamblia is incapable of de novo pyrimidine metabolism, as shown by its inability to incorporate orotate, bicarbonate, and aspartate into the pyrimidine nucleotide pool.
(15) Entamoeba coli was the most frequent protozoan (23.5%).
(16) In the macronucleus of the ciliated protozoan, Tetrahymena pyriformis GL, the genes coding for 17S and 25S rRNA exist as free, extrachromosomal molecules.
(17) Faecal samples were collected from 20 pigs in 4 age groups in randomly selected piggeries, and examined for the presence of eggs of helminth parasites and protozoan cysts.
(18) Nucleoside salvage pathways are vital to the parasitic protozoan Trypanosoma cruzi, and have become important targets in the development of new chemotherapeutic agents against this organism.
(19) It is now well established that pathogens such as viruses, fungi bacteria and protozoans can have profound effects on the dynamics of their invertebrate host populations.
(20) Leishmania donovani, the protozoan causing visceral leishmaniasis, is an obligate intracellular parasite of mammalian macrophages.
Trichocyst
Definition:
(n.) A lasso cell.
Example Sentences:
(1) We had previously shown that a phosphoprotein of 63 kDa ('PP63') is rapidly and selectively dephosphorylated during synchronous (less than or equal to 1 s) trichocyst exocytosis in Paramecium cells and then rephosphorylated within less than or equal to 1 min [Zieseniss & Plattner (1985) J.
(2) Therefore, in comparison with the reported cytosolic pH (6.8), trichocysts cannot be considered as essentially acidic compartments.
(3) Distinctive features include a complex cytoskeleton which defines the cell organization and interconnects cell components; trichocysts which resemble those in other cryptoprotists; and two non-photosynthetic plastids.
(4) Crosses between members of two independent collections of Paramecium tetraurelia mutants blocked in the final membrane fusion step of trichocyst release (nd mutants) allowed us to define 13 complementation groups comprising 23 alleles.
(5) Trichocysts from mutants defective to varying degrees in trichocyst formation were subjected to similar experimental protocols.
(6) When paramecia were treated only with Ca++ and then fixed with OsO4 plus oxalate or merely with glutardialdehyde, electron scattering deposits were formed also on the inner side of the cell membrane and within the ciliary shaft (but rarely in trichocysts).
(7) Morphological evidence that supports this grouping is the layer of sacs underneath the plasma membrane in all three taxa and the identical structure of trichocysts in the apicomplexan Spiromonas and dinoflagellates.
(8) From this comparison between wild type and mutants, we conclude: (a) that the formation of parentheses is a primary differentiation of the plasma membrane, independent of the presence of trichocysts, while the secondary transformation of parentheses into circular arrays and the formation of the rosette are triggered by interaction between trichocysts and plasma membranes; and (b) that the formation of the rosette is a prerequisite for trichocyst exocytosis.
(9) The mAbs were cross-reactive with the trichocysts of P. primaurelia, P. tetraurelia, P. caudatum and P. calkinsi with some small variation in blotting patterns.
(10) The ciliate protozoan Paramecium tetraurelia produces secretory granules (trichocysts) which release needle-like structures composed of small, acidic proteins.
(11) Characteristic arrangements of membrane-intercalated particles (MIPs) occur over trichocyst docking sites: 300 nm large double rings of MIPs and a MIP rosette in the middle.
(12) Element analysis by energy dispersive x-ray microanalysis ascertained the presence of Ca and P in deposits occurring in trichocysts.
(13) Four mAbs (131C1E8, A1-3, A16-2, D7) were directed to a trio of bands of 37, 34 and 29 (x 10(3] Mr from the beaded or meshlike trichocyst body sheath.
(14) A polyclonal antibody directed against the luciferase of the luminous dinoflagellate Gonyaulax polyedra labels both dense vesicles and trichocyst sheaths, as visualized in the electron microscope after treatment of antibody-reacted sections with an immunogold probe.
(15) On the plasma membrane of Paramecium circular arrays of particles mark the sites of attachment of the tips of the intracellular secretory organelles-trichocysts.
(16) Upon release the trichocyst membrane fuses with the cell membrane and the trichocyst content undergoes a Ca2+-dependent irreversible expansion.
(17) The number of non-docked, free trichocysts in the cytoplasm is only slightly changed, indicating a continuous synthesis and docking rate (approximately 2-3 organelles per min).
(18) This mutant was chosen because it is the best known of its class to date and seems to be altered in assembly of the material connecting the trichocyst membrane to the plasma membrane and in assembly of the "rosette," a complex array of intramembranous particles in the plasma membrane at the trichocyst insertion sites.
(19) Those "resting" trichocysts which were devoid of deposits did not contain Ca or P enriched.
(20) The resulting needle-like extended trichocyst matrix (xtmx), also paracrystalline, is released outside the cell.