Search results for "Pigs"
showing 10 items of 331 documents
Usefulness of omp1 restriction mapping for avian Chlamydia psittaci isolate differentiation
1995
Abstract Sixty-five avian Chlamydia psittaci isolates collected worldwide, including 27 previously characterized reference strains, were analysed by restriction mapping of the major outer membrane protein gene ( omp1 ) obtained after DMA amplification by PCR. They were compared to 2 ruminant isolates, a feline pneumonitis and a guinea pig inclusion conjunctivitis (GPIC) isolate. According to their omp1 restriction patterns, avian strains were heterogeneous in that they exhibited 6 and 4 distinct patterns using Alu I and Mbo II restriction enzymes, respectively, thus defining 7 groups. However, 84% of the studied strains belonged to groups 1 to 4, which share a specific fragment triplet of 4…
Effect of sulfur dioxide on mucociliary activity and ciliary beat frequency in guinea pig trachea
1994
The effects of 30 min exposure to sulfur dioxide on mucociliary activity (MCA) and ciliary beat frequency (CBF) were studied in 31 guinea pig tracheas. MCA was measured by recording the light reflected from ciliated mucous membranes using an infrared bar code reader. CBF of single ciliated cells obtained by brushing was measured with phase-contrast microscopy. Each tracheal sample was exposed to SO2 at concentrations ranging from 2.5 to 12.5 ppm, or to air for control purposes. MCA and CBF were measured before and immediately after gas exposure. A reduction in mean MCA of 63% (P = 0.0007) and statistically insignificant changes in CBF (P > 0.05) were recorded at concentrations of 2.5 PPM SO…
An inherited deficiency of the third component of complement, C3, in guinea pigs
1986
Hereditary deficiency of the third component of complement, C3, is found very seldom in the human. C3 deficiency is associated with severe bacterial infections revealing the central role of C3 in complement activation via the classical or alternative pathway. We describe a new hereditary C3 deficiency in strain 2 guinea pigs. Serum from these animals had a markedly reduced lytic activity in a standard assay for complement-dependent, antibody-mediated cytotoxicity. In functional assays of individual components, the hemolytic activity of the components C4, C2, C5 and of factors B, D and H was in the normal range. The functional C3 titer, and similarly C3 antigenic activity in the serum of the…
Demonstration of High-Affinity Binding Sites for C3a Anaphylatoxin on Guinea-Pig Platelets
1978
3H-serotonin release from guinea-pig platelets was demonstrated to be the consequence of C3a binding to these cells. A Scatchard analysis of dose-response data of the 125I-C3a binding pattern to guinea-pig platelets pointed to the existence of binding sites with high and low affinity for the C3a molecule (HA and LA receptors). HA receptors are specific for C3a with intact C-terminal arginine. whereas C3adesarg only interacts with LA receptors. The release of serotonin may be induced by a combined reaction of C3a with HA receptors and LA receptors on the platelet membrane.
Comparative study on biological activities of various anaphylatoxins (C4a, C3a, C5a)
1981
Several anaphylatoxic substances (human C3a, guinea pig C3a, human C4a, guinea pig C5a, and a synthetic C3a-related hexapeptide) were compared with regard to their ability to induce secretion of [3H] serotonin from guinea pig platelets. Functional identity of the C3a preparations, C4a, and the hexapeptide was demonstrated by the phenomenon of crossed desensitization. Whereas C3a of human and guinea pig origin proved to be qualitatively and quantitatively identical, C4a expressed only 3% of the activity of the C3 fragments on a molar basis. Investigations with goat anti-guinea pig C3a demonstrate that human and guinea pig C3a possess one antigenic determinant in common; however, this determi…
Platelet Activation: a New Biological Activity of Guinea-pig C3a Anaphylatoxin
1978
3H-serotonin-release from labelled gp-platelets is established as a sensitive method for testing a new biological activity of gp-C3a anaphylatoxin in an autologous situation. Time-, dose- and temperature-dependent release reactions as well as specific inhibition by carboxypeptidase B and anti-C3a antibodies show that C3a is a potent and specific inducer of platelet activation. Inactive C3a does not induce 3H-serotonin-release but specifically inhibits the action of C3a on platelets.
Complexus adhaerentes, a new group of desmoplakin-containing junctions in endothelial cells: II. Different types of lymphatic vessels.
1994
Abstract In diverse mammalian species, including (man, cow and rat) the very flat endothelial cells of lymphatic vessels of various organs, including the retothelial meshwork of sinus of lymph nodes, are connected by zonula -like plaque-bearing junctions which differ from the similarly structured junctions of blood vessel endothelia by the presence of desmoplakin or an as yet unknown but closely related plaque protein. These extended junctions, which also contain plakoglobin but none of the presently known desmogleins and desmocollins, are therefore different from the spot-like desmosomes ( maculae adhaerentes ) present in epithelia, myocardium and dendritic reticulum cells of lymphatic fol…
Tetanus Toxin Inhibits Neuroexocytosis Even When Its Zn2+-dependent Protease Activity Is Removed
1995
Tetanus toxin (TeTX) is a dichain protein that blocks neuroexocytosis, an action attributed previously to Zn(2+)-dependent proteolysis of synaptobrevin (Sbr) by its light chain (LC). Herein, its cleavage of Sbr in rat cerebrocortical synaptosomes was shown to be minimized by captopril, an inhibitor of certain metalloendoproteases, whereas this agent only marginally antagonized the inhibition of noradrenaline release, implicating a second action of the toxin. This hypothesis was proven by preparing three mutants (H233A, E234A, H237A) of the LC lacking the ability to cleave Sbr and reconstituting them with native heavy chain. The resultant dichains were found to block synaptosomal transmitter…
Pyridinedicarboxylates, the first mechanism-derived inhibitors for prolyl 4-hydroxylase, selectively suppress cellular hydroxyprolyl biosynthesis. De…
1987
Two pyridinedicarboxylates, predicted [Hanauske-Abel (1983) M.D.-Ph.D. Thesis, Philipps Universität Marburg] and later found to be potent reversible inhibitors of purified prolyl 4-hydroxylase [Majaama, Hanauske-Abel, Günzler & Kivirikko (1984) Eur. J. Biochem. 138, 239-245] were investigated with respect to their effect on hydroxyprolyl biosynthesis in the fibroblast/collagen and the macrophage/Clq systems, and the effect was compared with that of the iron chelator 2,2′-dipyridyl, the compound usually employed to inhibit cellular hydroxyprolyl formation. Only the enzyme-mechanism-derived pyridinedicarboxylates were highly selective inhibitors, and only they lacked overt cytotoxicity. M…
Electron microscopic localization of nitric oxide I synthase in the organ of Corti of the guinea pig
1997
Nitric oxide synthase (NOS) activity has been detected previously in the mammalian cochlea at a light microscopic level. Here we present results of electron microscopic analysis for post-embedding immunoreactivity of neural-type NOS I in the cochlea of the guinea pig. Strong enzyme immunoreactivity was identified in the cytoplasm of inner and outer hair cells. Gold-labeled NOS I antibodies were mainly located in electron-dense areas of the cytoplasm, whereas electron-lucent regions of the receptor cells were nearly free from any immunoreactivity. In both types of hair cells anti-NOS I antibodies were also visible in the cuticular plates, hair bundles and nuclei. Further ultrastructural anal…