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F Ciampor

Publications and source records attributed to F Ciampor.

At least 37 records · Page 2Linked to original sources
PubMed1990

Polypeptides induced in chick embryo cells by Kemerovo virus.

Fifteen polypeptides induced by Kemerovo virus were detected in chick embryo cells (Mr 140, 98, 89, 72, 65, 62, 57, 54, 50, 47, 43, 41, 39, 31 kD, and 30 kD). Nine of them, namely the 140, 98, 65, 62, 57, 54, 50, 47 kD, and 41 kD polypeptides were also found in the partially purified virus. However, the latter contained also considerable amount of host cell proteins, predominantly the 205 kD, 45 kD, and 37 kD polypeptides. In the electron microscope the spherical viral particles exhibited a poorly defined surface structure of a diameter of 70-75 nm.

Animals↗
PubMed1989

Mechanism of altered cytoskeleton organization in influenza virus infection.

We followed the autophosphorylation of cytoskeleton (CS) isolated from control chick embryo cell membranes (CS-C) and from these membranes after influenza virus adsorption (CS-V) under conditions allowing to determine the activity of a single type proteinkinase. The Ca2+ dependent calmodulin (CaM) kinase used different substrates from CS-V than did the c'AMP dependent proteinkinase. The catalytic subunit (c-subunit) of the c'AMP dependent proteinkinase added from outside phosphorylated the same polypeptides than the endogenous c'AMP dependent proteinkinase, the further being more active than the latter. The purified influenza virus incorporated 32P in the presence of the c-subunit only. Incubation of influenza virus with the c-subunit caused morphological changes visible by electron microscopy. The pleomorphy of the particles as well as their electron transmissibility were enhanced in result of structural alterations and rarefaction of surface spikes of the haemagglutinin and neuraminidase. The contractibility of CS isolated from normal CEC and of the CS from CEC by 15 min postinfection (p.i.) was determined according to the actomyosin ATPase activity. The ATPase activity of the cytoskeleton in the presence of the Ca2+/CaM and that in the presence of c'AMP were used as controls. The virus as well as the Ca2+/CaM increased the ATPase activity. EGTA had no effect but did not interfere with virus stimulation, while c'AMP blocked the virus-induced enhancement of the ATPase activity.

Actins↗
PubMed1988

The role of cytoskeleton and nuclear matrix in virus replication.

In the light of the cytoarchitecture concept, the presented review attempts to cover what is known of the involvement of cytoskeletal and nucleoskeletal elements in the replication cycle of various viruses and in cell transformation. Our knowledge on the relationship of virus replication with cell architecture has rapidly progressed during the recent years in association with studies on composition of various filaments within cells, their spatial organization and possible functions which focussed much interest on the cytoskeleton and nuclear matrix. The new results indicated that highly specialized elements for normal cell function may be coopted for virus growth. Recently, using various methodical approaches it has been possible to obtain information about the association of virus-structural proteins with cytoskeletal and nucleoskeletal elements, about the reorganization of cytoskeleton during virus replication, about the role of tubulin in transcription and RNA synthesis of negative-strand viruses, about the involvement of cytoskeletal filaments in the transport of viral proteins, virus penetration, virus assembly and release from the infected cell. The role of cytoskeleton in cell transformation and in initiation of DNA synthesis and intracellular signaling to cell proliferation has been also investigated.

Adenoviridae↗
PubMed1987

Experimental double infection with Coxiella burnetii and tick-borne encephalitis virus in Dermacentor reticulatus ticks.

Experimental parenteral inoculation of Dermacentor reticulatus ticks with the rickettsia Coxiella burnetii (C.b.) and tick-borne encephalitis (TBE) virus resulted in a generalized rickettsial and viral infection, irrespective of whether the agents were given simultaneously or by a 7 days interval apart. Both agents multiplied intensively in ticks, C.b. being detectable predominantly in cytoplasmic vacuoles and TBE virus mostly in the endoplasmic reticulum.

Animals↗
PubMed1987

Production of human influenza virus in a stabile line of guinea pig tongue cells expressing endogenous oncovirus: an electron microscopic study.

Guinea pig tongue (GPT) cells represent a highly sensitive host system for influenza A/WSN (H1N1) infection as evidenced by numerous ultrastructural changes, considerable production of NS1 protein and widespread budding of viral particles at the cytoplasmic membrane. Vesicles of smooth endoplasmic reticulum and of the Golgi complex were transported to the apical area of cell membrane, where the budding of virions took place. Numerous microtubules were directed vertically to these portions of plasma membrane. In contrast, maturation of the endogenous oncovirus particles occurred at the lateral cytoplasmic membrane. Beneath the area of oncovirus maturation and release, a network was seen of microfilaments oriented towards the plasma membrane. The cytoplasm of GPT cells contained numerous nonstructural protein inclusions, which evidently accumulated at the periphery of nucleoli and were seen to reach the cytoplasm crossing the pores of nuclear membrane.

Animals↗
PubMed1986

Studies on preparation of a tick-borne encephalitis (TBE) vaccine from the Skalica strain.

Diethylether-treated vaccine against tick-borne encephalitis (TBE) represents a new type vaccine consisting of lipid-free and antigenically efficient components instead of whole virus particles. The TBE virus strain designated Skalica was used for vaccine preparation. This strain is thermosensitive, produces small plaques under agar overlay, is nonpathogenic for adult white mice following subcutaneous (s.c.) application and causes threshold viraemia in host animals. The vaccine was harmless and immunogenic as evidenced by experiments on white mice. Antibodies to TBE virus strain Ir 13 present in human healthy population of a natural TBE focus showed similar levels when tested with the Skalica strain. The Skalica virus strain can be recommended for preparation of the vaccine against TBE.

Animals↗
PubMed1986

Effect of influenza virus on the interaction of cytoskeleton with cell membranes.

The effect of influenza virus on the organization of cytoskeleton (CS) associated with cell surface plasma membranes (PM) of chick embryo cells (CEC) was investigated. The CS isolated from virus-treated PM contained more proteins and more actin than the CS isolated from control membranes. Virus particles were found to be associated with this CS, although the purified virus alone, treated in the same manner, did not sediment at low speed in the residue insoluble in Triton X-100. Autophosphorylation of CS, especially of the polypeptides 24 K, 45 K, 65 K and 105-110 K, was increased in CS prepared from virus-treated membranes. Superprecipitation of the CS prepared from CEC was stimulated by addition of the virus. Electron microscopy of the Triton X-100 insoluble residue from virus-treated PM showed more structures similar to microfilament bundles than Triton X-100 insoluble residue from control membranes. Based on these results we suggest that already in early stages the virus infection leads to a reorganization of membrane-associated CS.

Actins↗
PubMed1985

Pathogenesis of acute and persistent murine herpesvirus infection in mice.

Outbred laboratory mice were inoculated at the age of 5, 10 and 21 days by oral and/or intranasal routes with 2 different (a lethal and a nonlethal) doses of the murine herpesvirus isolate 68 (MHV-68). Severe exudative pneumonia with haematogenous dissemination of the virus to liver, heart muscle, and kidneys developed in the 5-day-old as well as in a part of the 10-day-old mice. Virus antigen was found by immunofluorescence (IF) in the alveolar lining of lungs, in heart muscle fibres, in spleen and thymic lymphocytes, in the tubular epithelium cells of kidneys, in the neurons of Gasserian ganglia and in the intima of large pulmonary vessels. Electron microscopy confirmed the transfer of virus particles through the capillary endothelium of the damaged alveolar septa. The surviving progeny and the mothers of animals, which had not succumbed to the lethal virus dose, were kept for 141-169 days when lungs and Gasserian ganglia were examined for virus presence. MHV-68 was recovered both by direct examination of the tissue homogenates as well as by the explantation technique. The results are suggestive for a dynamic persistence of MHV-68 rather than for static latency.

Animals↗
PubMed1984

Actin organization in chick embryo fibroblasts after influenza virus infection. I. Isolation and characterization of actin from chick embryo cells.

Comparison of two starting materials for actin purification has shown that preparation of actin from aceton-dried cytoskeleton was more effective than from native chick embryos (CE). The isolated actin formed a single band of Mr = 42-43000 in SDS-PAGE; less purified samples revealed additional faint bands. G form of actin (non-polymerized) inhibited the activity of DNase I, electron microscopy showed actin filaments and bundles formed upon its polymerization. The freshly purified homogeneous actin has not lost its DNase I-inhibiting activity when incubated for 60 min at 35 degrees or 45 degrees C. Older or less purified actin samples kept under similar conditions showed 18-25% decrease of their DNase I-inhibiting activity and a loss of their polymerization ability. Digestion with trypsin caused a decrease of DNase I-inhibiting activity of fresh as well as for older actin samples.

Acetone↗
PubMed1984

Incidence of paramyxoviruses in free-living birds in 1978-1982.

Together 41 paramyxovirus (PMV) strains (25 PMV-1, 10 PMV-4, and 6 PMV-6 serotypes) were isolated from cloacal swabs of 910 free-living birds trapped in West Slovakia from 1978 to 1982. The PMV strains were found in 9, mostly aquatic bird species. Strains belonging to the PMV-1 serotype were isolated yearly, indicating its wide distribution and circulation in nature. The strains of PMV-4 and PMV-6 serotypes found only in 1978-1980, represented the first isolations in Europe. Antigenic analysis by haemagglutination-inhibition (HI), neuraminidase-inhibition (NI), complement-fixation (CF), and gel double diffusion (DD) tests proved the relatedness of the surface antigens of newly isolated PMV strains with those of PMV-4/ Duck Hong Kong D3/75 and PMV-6/Duck/Hong Kong 311/80 strains. One-way reaction between PMV-4 serotype and mumps virus was demonstrated using hyperimmune rat sera. Electron microscopic observation of isolated virus strains revealed structures typical of PMV.

Animal Population Groups↗
PubMed1983

Production of monoclonal antibodies with haemagglutination-inhibition activity to the Skalica strain from the tick-borne encephalitis complex.

Hybridomas secreting monoclonal antibodies with haemagglutination-inhibition (HI) activity to the Skalica strain of tick-borne encephalitis (TBE) complex were prepared by the fusion of P3-NS1-Ag4-1 myeloma cell line with spleen cells of BALB/c mice immunized with the purified Skalica strain. The highest titres of monoclonal antibodies obtained from the hybridomas S-9, S-15 and S-16 ranged from 512 to 10,240, respectively; the ascitic fluid contained as many as 4.6 mg/ml of monoclonal antibodies. Its analysis by Ouchterlony's double immunodiffusion, agarose electrophoresis, and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of monoclonal antibodies with mu isotype of the heavy and kappa isotype of the light chain. The specificity of the monoclonal antibodies was proved using 11 different antigens from family Togaviridae in the HI test.

Animals↗
PubMed1983

Optimalized conditions of tick-borne encephalitis virus production in vitro.

Conditions of the efficient production of tick-borne encephalitis (TBE) virus in chick embryo cell (CEC) monolayer cultures were investigated. The prerequisites of high recovery of the produced virus appeared to be: the use of dense cell monolayers, reasonable frequency of harvests and a suitable buffering of nutrient media. Using low input multiplicity of infection, the peak of the serum-free virus production was observed between 24 and 48 hr post infection (p.i.). The procedure elaborated was useful for isotopic labelling of the virus.

Animals↗
PubMed1983

Experimental model of transovarial transmission of Tahyna virus in Aedes aegypti mosquitoes.

The progeny of 31 viruliferous Aedes aegypti females infected with Tahyna virus by sucking on viraemic newborn mice was investigated for virus presence. Out of 1587 individuals of the F1 generation, 16 suspensions representing the progeny of 7 females were positive in 146 trials. Individuals of the F1 generation failed to transfer the virus by sucking. Electron microscopy revealed the presence of Tahyna virus particles in the cytoplasm of maturing oocytes inevitably confirming the transovarial transfer of the virus by germinal cells of Aedes aegypti mosquitoes.

Aedes↗