[Main structures of viruses and the significance of virus glycoproteins for the process of infection and for influenza virus variability].
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Glycoproteins↗
Biomedical subjects
F Ciampor
Publications and source records attributed to F Ciampor.
Ultrastructural studies on the replication of herpes simplex virus in PK and XTC-2 cells.
Ultrastructural changes showed the following characteristics of restricted replication of herpes simplex virus 1 (HSV 1) strains MA and HSZP in PK and XTC-2 cells: 1) minimal cytopathic changes in PK cells as compared to more pronounced alterations in XTC-2 cells; 2) formation of single nucleocapsids or their absence in the nuclei of PK cells infected with the HSZP strain; 3) lack of budding and envelopment and absence of reduplication of the nuclear membrane; 4) persistence of partially uncoated virions within the endocytic vacuoles in the cytoplasm of PK cells; and 5) formation of dense inclusion bodies in addition to the presence of defective virions in the cytoplasm of XTC-2 cells and vacuolation of their cytoplasmic membranes. The replication of HSV 1 in PK and XTC-2 cells seemed to be blocked at both early and late stages of virus replication. At low multiplicity of infection, no virus particles were formed.
Animals↗
Influence of chlorpromazine on the replication of influenza virus in chick embryo cells.
Influence of chlorpromazine (CPZ) on the production of influenza virus was followed in chick embryo cell (CEC) monolayers. CPZ--which binds specifically to calmodulin (CaM)--inhibited in concentration of 20-100 mumol/l the activity of CaM-stimulated 3', 5'-c'AMP phosphodiesterase (PDE). When administered together with the virus, CPZ in concentrations of 20-50 mumol/l reduced virus yields by 2-3 log PFU. Addition of CPZ 15 min before or 1 hr after influenza virus adsorption had no effect. The inhibitory action of CPZ was reversed by purified CaM. The adsorption of influenza virus to CEC or to erythrocytes was not affected. The participation of CaM on the mechanism of influenza virus penetration is discussed.
3',5'-Cyclic-AMP Phosphodiesterases↗
[A case of hand-foot-and-mouth disease with clinical diagnosis promptly confirmed by electron microscopy (author's transl)].
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Child, Preschool↗
[Virus envelope glycoproteins and their significance for cell infection in some RNA--and DNA--containing viruses].
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DNA Viruses↗
Electron microscopy of rabbit embryo fibroblasts infected with herpesvirus isolates from Clethrionomys glareolus and Apodemus flavicollis.
Electron microscopy of rabbit embryo fibroblasts infected with five herpesvirus isolates from murine rodents (Clethrionomys glareolus and Apodemus flavicollis) revealed morphological changes characterized by the formation of intranuclear vacuoles, in which envelopment of nucleocapsids took place. The herpesvirus nucleocapsids were formed in the vicinity of intranuclear granular inclusions. Margination of chromatin, disaggregation of nucleoli and, in some isolates, the occurrence of tubular structures with a diameter of 33--35 nm characterized the ultrastructural changes in the nuclei. In the cytoplasm, membraneous vacuoles, containing numerous naked nucleocapsids and, in some isolates, large electron-dense bodies, containing non-enveloped nucleocapsids, were formed. Extracellular spaces contained either enveloped virions which, besides nucleocapsids, contained in their envelope a part of the dense material from intracytoplasmic dense bodies, or viral envelope-like structures without nucleocapsids partially filled with dense material from intracytoplasmic dense bodies. Ultrastructural development of these isolates in REF resembled that of freshly isolated herpes simplex type 1 viruses but some morphological changes resembled those characteristic of cytomegaloviruses.
Animals↗
A rickettsia-like organism showing positive immunofluorescence with antisera to Coxiella burnetii in Haemaphysalis inermis ticks.
A rickettsia-like organism (RLO) was detected in the oocytes of Haemaphysalis inermis ticks. The RLOs were about 5 microns long bent rods with a definite inner structure. They were Gram-negative and could be visualized by Giemsa but not by Gimenez staining. Attempts to cultivate the RLO in chick embryo yolk sacs, various types of cell culture and tick body cavities were unsuccessful. The RLO displayed a bright immunofluorescence with antisera to Coxiella burnetii, but no immunofluorescence was obtained with antisera to representatives of typhus and spotted fever group rickettsiae, with the exception of very weak fluorescence with serum from a rabbit immunized with Rickettsia akari and one serum from Apodemus flavicollis immunized with Rickettsia conorii. These findings should be taken into consideration when studying the infestation of ticks with rickettsiae.
Animals↗
Ultrastructural localization by immunoperoxidase techniques of influenza virus antigens in abortive infection of L cells.
An abortive infection was induced in L cells by influenza virus A/Hong Kong/68 (H3N2). With the use of antibody and peroxidase-labelled protein A, the localization of virus protein synthesis but not the maturation of virus particles was demonstrated at the ultrastructural level. Five days after inoculation (p.i.), the synthesis of viral haemagglutinin was localized in the region of the rough endoplasmic reticulum; at late intervals p.i., haemagglutinin accumulated in the plasma membranes, where membrane vesicles, containing haemagglutinin in their membranes, were released from the cell surface. The cytoplasmic viral ribonucleoprotein was localized in the region of free cytoplasmic ribosomes and that of the outer sheet of the nuclear membrane. Viral proteins were detected in the cytoplasm and plasma membranes also after 70 and 390 days of passaging of the cells or of their long-term cultivation with regular change of medium.
Animals↗
Accelerated appearance of an ascitic tumour after long-term application of interferon to NZB/W mice.
In two similarly designed experiments female NZB/W mice treated with mouse L-cell interferon developed an ascitic tumour when the treatment was begun at 3.5 months of age. But no tumour appeared within a 6 months' observation period when 6 months old mice were used. A transient rise of anti-DNA antibodies preceded the tumour appearance in mice. The ascitic tumour was sensitive to antimetabolites and insensitive, or marginally sensitive, to alkylating agents or interferon. The tumour cells were adapted to growth in suspension in vitro. They caused tumour growth in various inbred and random-bred mouse lines. Attempts to transfer the tumour to Swiss mice with cell free preparations were unsuccessful.
Animals↗
Isolation of paramyxovirus type 4 from Oeciacus hirundinis bugs.
Three virus strains were isolated from a total of 1356 Oeciacus hirundinis bugs collected in nests of Delichon urbica in Slovakia by inoculation of chick embryos into the amniotic and allantoic cavities. The strains agglutinated rooster and guinea pig erythrocytes and were identified as paramyxovirus type 4.
Animals↗
Latent herpesvirus hominis 1 in the central nervous system of psychotic patients.
Cerebrospinal fluids (CSF) from 35 patients with senile or presenile dementia and from 13 patients with schizophrenia and related syndromes were examined in cell cultures with the aim to isolate Herpesvirus hominis 1 (HVH 1) or other viruses. Serum and CSF antibodies to HVH 1 and/or interferon in the patients indicated a recent HVH 1 antigenic or viral activity. In the CSF of two senile demented patients and of one patient with schizoaffective psychosis, agents of low virulence, causing a cytopathic effect in 3 or 4, but not more, subsequent passages were detected and identified as HVH 1 by immunofluorescence. A focus of cells containing HVH 1 antigen at the cell membrane and in cytoplasm was visualized by immunofluorescence in an explant from nucleus amygdalae from 1 of 6 patients with schizophrenia and related syndromes examined. In the original biopsy materials, various virus-like structures were found in nuclei and cytoplasm of astrocytes and neurocytes and in axons in the neuropil.
Adult↗
Isolation of Tettnang virus from Ixodes ricinus ticks in Czechoslovakia.
Three virus strains closely related to Tettnang virus were isolated from nymphs and males of Ixodes ricinus tick in Moravia and Slovakia. The virus isolates were lethal for suckling mice on intracerebral (i.c.) inoculation but the virus titres in the brain were low. The incubation period of 5--12 days in the first mouse passage was shortened to 3 days in further passages. Infection of mice was accompanied by ultrastructural changes in the cytoplasm of neurons. Groups of spherical virus particles 75 to 80 nm in diameter occurred within simple vacuoles.
Animals↗
Experimental pathogenesis of non-lethal herpesvirus infection and the establishment of latency.
In rabbits inoculated into the right scarified cornea with the Kupka strain of human Herpesvirus type 1 (HHV 1), healing of the keratitis occurred between days 8--12 post infection (p.i.). Viral particles were seen in nuclei and cytoplasm of corneal epithelium cells and in a few fibrocytes of corneal stroma. By immunofluorescence and electron microscopy, the virus was demonstrated in single neurons and satellite cells of the homolateral Gasserian ganglion since 24 hr p.i. From 20 hr to 8 days p.i., HHV 1 was found in ganglia of 7 out of 15 rabbits, while the explantation was positive in 10 out of 12 animals. In the course of latency, single HHV antigen-containing cells were seen in ganglia of 3 out of 7 rabbits and virus isolation attempts before explantation always were negative. Viral antigen was found in single ganglion cells only in 20% of rabbits with healed corneal lesions while the explanation of the ganglion tissue yielded HHV at an unchanged high frequency (92% of animals).
Animals↗
Methods of re-embedding tissues and cell suspensions for electron microscopy.
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Cytological Techniques↗
Ultrastructure of some cutaneous sense organs in Dermacentor marginatus nymphs.
The fine structure of the integumentary glands and mechanoreceptory setae in Dermacentor marginatus nymphs is described. The integumentary gland is localized in the epidermal layer and secretory products pass through the duct lumen and two cuticular lips to the surface. Ultrastructure of cuticular cavity represents triangular form with lateral folds. The mechanoreceptor setae are composed of glandular cells localized in the epidermal layer and cuticular setae movably articulated to the cuticle by means of a compact fibrillar ring around the base.
Animals↗
[Electron microscopy of tissue cultures infected with influenza viruses].
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Animals↗
Activation of latent herpesvirus hominis in explants of rabbit trigeminal ganglia: the influence of immune serum.
More than fifty albino rabbits were inoculated into the right scarified cornea with 10(7) PFU of the Kupka strain of human herpes virus type 1 (HHV-1). At intervals ranging from 4--280 days post infection (p.i.), both gasserian ganglia, both trigeminal nerve trunks and pieces from brain stem and from both corneas were explanted. Activation of the latent HHV-1 was found mainly in the homolateral ganglion tissue, but also in explants originating from the opposite ganglia. Within 24--72 hours, prior to the release of virus into the medium, one infectious unit of HHV was recovered from 10(4)--10(5) cells of the ganglion explant. In addition, a few neurons and satellite cells revealed the presence of virus-specific antigens when the explants were examined by immunofluorescence in serial sections. If the gangia were explanted in the presence of immune serum, the virus recovery rate was at least twice lower as compared to the virus activation in explants kept in the absence of immune serum.
Animals↗
Transmission of alfalfa mosaic virus through Nicandra physaloides seeds and its localization in embryo cotyledons.
Alfalfa mosaic virus (AMV) was found to be transmitted through seeds of Nicandra physaloids L. The average seed transmission rate of the AMV isolates T6, LMBG-4 and ST amounted to 23, 4 and 0 per cent, repectively. In the cytoplasm of parenchyma cells of embryo cotyledons of seeds from plants infected with the T6 isolate, electron microscopy revealed AMV aggregates of type 2A and aggregations of irregularly viral particles with a tendency to subparallel alignment, representing early stages of type 2A aggregates.
Cytoplasm↗