RESUMO
Primary structure and proteins of measles virus variants passaged in tissue culture were studied. The findings suggest that genetic determinants responsible for measles virus attenuation are not linked with the genes coding for envelope proteins and nucleoprotein of this virus. However the detected nucleotide substitutions can be considered as the main prerequisites for the appearance of mutations in other regions of viral genome, leading to decrease of virulence for humans.
Assuntos
Vírus do Sarampo/imunologia , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Sequência de Bases , Chlorocebus aethiops , Técnicas de Cultura , Genes Virais , Vírus do Sarampo/genética , Vírus do Sarampo/patogenicidade , Mutação , RNA Viral , Inoculações Seriadas , Células Vero , Proteínas Virais/genética , VirulênciaRESUMO
The effect of various concentrations of both methyl ether of 5-doxyl-stearic acid (M5DS) and 4-maleimido-TEMPO (4MT) on the pathogenicity of herpes simplex virus (HSV-1) was studied. It is known that the reagents modify the lipid matrix and the proteins of virion envelope. The decrease of the HSV-1 pathogenicity was shown when using the concentration of reagents more 5 x 10(-5) M. HSV-1 having high pathogenicity and cytotoxicity was obtained when the concentrations of the reagents were less 5 x 10(-5) M.
Assuntos
Óxidos N-Cíclicos/farmacologia , Macrófagos/microbiologia , Simplexvirus/efeitos dos fármacos , Marcadores de Spin , Animais , Células Cultivadas , Efeito Citopatogênico Viral , Camundongos , Camundongos Endogâmicos CBA , Simplexvirus/patogenicidade , Análise EspectralAssuntos
Vacina contra Sarampo/administração & dosagem , Vírus do Sarampo/isolamento & purificação , Sarampo/prevenção & controle , Anticorpos Antivirais/biossíntese , Humanos , Sarampo/epidemiologia , Sarampo/imunologia , Vírus do Sarampo/imunologia , Vírus do Sarampo/patogenicidade , Federação Russa/epidemiologiaAssuntos
Adenilil Ciclases/metabolismo , Herpesviridae/imunologia , Imunidade Celular , Macrófagos/imunologia , Fosfolipases A/metabolismo , Animais , Membrana Celular/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Herpesviridae/metabolismo , Herpesviridae/patogenicidade , Peroxidação de Lipídeos , Macrófagos/enzimologia , Camundongos , Camundongos Endogâmicos CBA , Fosfolipases A2 , VirulênciaRESUMO
The possibility of long persistence of influenza virus A in the brain and other organs of mice was established on the basis of complex virological, histological and electron microscopic studies. It was shown that the perivascular oedema of choroid plexus reaches the maximum during late stages of infection, after the clinical recovery. Sharp increase of the permeability of cerebral vessels causing the perivascular oedema, especially in choroid plexus of lateral brain ventricles, proposed to be one of possible mechanisms of pathogenic action of the virus.
Assuntos
Encéfalo/patologia , Infecções por Orthomyxoviridae/patologia , Vísceras/patologia , Animais , Encéfalo/microbiologia , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/patogenicidade , Camundongos , Infecções por Orthomyxoviridae/microbiologia , Fatores de Tempo , Vísceras/microbiologiaRESUMO
The complex virological, biochemical and morphological study permitted to obtain various characteristics of mice herpes encephalitis. The reaction of astrocyte glia at different stages of herpes encephalitis was revealed and analyzed in detail. New data on the dynamics of desoxyribonuclease activity changes in neuroglia and the glial complex formation were obtained. It was shown that the increased DNA-ase activity in neuroglia and the astrocyte activation which morphological manifestation was the formation of glial complexes, may be referred to as processes dealing with barrier and elimination neuroglia functions in herpes encephalitis. The results presented allows to suppose that the severity of the development and outcome of herpes encephalitis mainly depends on the astrocyte glia condition, its potential abilities in appearing of barrier and eliminative functions.
Assuntos
Encefalite/enzimologia , Herpes Simples/enzimologia , Neuroglia/enzimologia , Animais , Astrócitos/enzimologia , Astrócitos/ultraestrutura , Desoxirribonucleases/metabolismo , Encefalite/patologia , Herpes Simples/patologia , Histocitoquímica , Lisossomos/enzimologia , Lisossomos/ultraestrutura , Camundongos , Camundongos Endogâmicos CBA , Neuroglia/ultraestrutura , Neurônios/enzimologia , Neurônios/ultraestrutura , Ribonucleases/metabolismo , Fatores de TempoRESUMO
The influence of influenza virus infection on the brain cells was studied in mice. Virology, electron microscopy and biochemistry methods were used for this purpose. It has been shown that intracerebral injection of pathogenic strain of influenza virus A/PR/8/34 is accompanied both by the reproduction of virus in the central nervous system tissue and the morphology changes in ependial cells of the vascular plexus of the brain lateral ventricle. It has been found that the level of the lipid peroxidation products in lipid extracts of infected mouse brain is greater than their level in extracts from control mouse brain. It has been concluded that the influenza virus has a damaging effect on the central nervous system cells.
Assuntos
Encéfalo/ultraestrutura , Peróxidos Lipídicos/biossíntese , Infecções por Orthomyxoviridae/patologia , Animais , Encéfalo/metabolismo , Epêndima/metabolismo , Epêndima/ultraestrutura , Camundongos , Microscopia Eletrônica , Infecções por Orthomyxoviridae/metabolismoRESUMO
Comparative studies of biological properties of influenza A (H3N2) viruses isolated in the epidemics of 1980 and 1983 and in the interepidemic period of 1982 showed a sharp reduction of the biological activity of the interepidemic viruses as compared with that of the epidemic ones. This was manifested by low isolation rate of virus in the interepidemic period, reduced hemagglutinating, interfering, and immunogenic activity of these viruses, poor reproduction in the lung tissue of white mice and the lack of virus-specific syntheses in splenocytes of infected Syrian hamsters. Unlike epidemic strains, the interepidemic strains had ts mutation in gene 6 coding for neuraminidase. There are reasons to associate the observed defect in gene 6 with frequent development of asymptomatic forms of influenza infection in the interepidemic period.
Assuntos
Surtos de Doenças , Vírus da Influenza A Subtipo H3N2 , Vírus da Influenza A/fisiologia , Influenza Humana/microbiologia , Animais , Anticorpos Antivirais/análise , Antígenos Virais/análise , Antígenos Virais/imunologia , Cricetinae , Genes Virais , Humanos , Vírus da Influenza A/isolamento & purificação , Vírus da Influenza A/patogenicidade , Influenza Humana/epidemiologia , Camundongos , Mutação , Federação Russa , Interferência ViralRESUMO
Virus-induced processes in organs and tissues of Syrian hamsters in relation to the influenza A virus strain used (HON1 or H3N2), age of the animals, and in the presence of mixed infection were compared. The infection of young hamsters with A/PR8/34 and A/Bangkok/1/79 viruses was shown to induce the synthesis of viral proteins NP and M in spleen cells lasting for up to 15 days (the observation period). In mixed influenza and respiratory syncytial virus infection the possibility of influenza virus genome expression did not change. After infection of mature hamsters, synthesis of virus-specific NP and M proteins in splenocytes was observed only in the animals infected with influenza A/PR8/34 virus but not in those infected with the less pathogenic influenza A/Bangkok/1/79 virus.
Assuntos
Vírus da Influenza A/fisiologia , Infecções por Orthomyxoviridae/microbiologia , Baço/microbiologia , Replicação Viral , Envelhecimento/fisiologia , Animais , Anticorpos Antivirais/análise , Cricetinae , Vírus da Influenza A/imunologia , Mesocricetus , Infecções por Orthomyxoviridae/imunologia , Proteínas Virais/biossínteseRESUMO
Investigation of influenza A (H3N2) epidemic of 1983 in Leningrad revealed simultaneous circulation of 3 antigenic variants similar to A/Bangkok/1/79, A/Bangkok/2/79, and A/Philippines/2/82 with significant predominance of the first antigenic variant. The viruses related to A/Philippines/2/82 comprising one-third of all isolations produced antibodies of a wide spectrum unlike the other two variants whose antisera neutralize actively the homologous virus only. The possibility of selecting epidemic strains of the A/Philippines/2/82 variety as vaccine strain candidates is discussed.
Assuntos
Surtos de Doenças , Vírus da Influenza A Subtipo H3N2 , Vírus da Influenza A/imunologia , Influenza Humana/microbiologia , População Urbana , Animais , Antígenos Virais/análise , Criança , Pré-Escolar , Variação Genética , Testes de Inibição da Hemaglutinação , Humanos , Imunização , Influenza Humana/epidemiologia , Pulmão/microbiologia , Camundongos , Neuraminidase/antagonistas & inibidores , Ratos , Federação Russa , Replicação ViralRESUMO
The use of correlation analysis has made it possible to reveal a high degree of influence exerted by influenza epidemics on morbidity rate in adenoviral, respiratory-syncytial, parainfluenza and mycoplasmic infections among the population. During the months of influenza epidemic considerable concomitant incidence of respiratory-syncytial, adenoviral and especially mixed infections was observed in all age groups in comparison with periods free from influenza epidemic. The study of concomitant morbidity during the periods of 6 influenza A (H3N2) epidemics and 3 influenza B epidemics has shown that the immunosuppressive activity of influenza virus, leading to the activation of other causative agents of acute respiratory diseases, reaches its highest level at the periods of influenza A epidemics characterized by a more intensive and severe clinical course of the disease, such as in influenza A/Victoria/35/72 (H3N2), and drops to a minimum at the periods of influenza B epidemics.
Assuntos
Surtos de Doenças/epidemiologia , Influenza Humana/epidemiologia , Infecções Respiratórias/epidemiologia , Doença Aguda , Infecções por Adenovirus Humanos/epidemiologia , Adolescente , Criança , Pré-Escolar , Humanos , Lactente , Infecções por Mycoplasma/epidemiologia , Infecções por Paramyxoviridae/epidemiologia , Vírus Sinciciais Respiratórios , Infecções por Respirovirus/epidemiologia , U.R.S.S.RESUMO
Examinations by the HI test of 652 sera from children aged from 9 months to 13 years revealed antibodies to A/Singapore/1/57 (H2N2) in 0.9% and A/PR/8/34 (H0N1) in 1.2% of the children. The specific nature of the activity of the sera was proved by neutralization tests and by treatment of the sera with Staphylococcus aureus adsorbing IgG class antibodies. Antineuraminidase antibodies to these viruses were also detected. Examinations of 247 paired sera from children revealed seroconversion to hemagglutinin and neuraminidase of A/Singapore/1/57 and A/PR/8/34 in 2% and 0.4%, respectively. These results testify to continuing circulation in the human population of influenza A virus subtypes of no current epidemiological importance.
Assuntos
Vírus da Influenza A Subtipo H2N2 , Vírus da Influenza A/imunologia , Adsorção , Anticorpos Antibacterianos/imunologia , Anticorpos Antivirais/análise , Especificidade de Anticorpos , Criança , Pré-Escolar , Testes de Inibição da Hemaglutinação , Humanos , Lactente , Neuraminidase/imunologia , Testes de Neutralização , Staphylococcus aureus/imunologiaRESUMO
Three epidemics of influenza A (H1N1) occurring in 1977, 1979 and 1981 were studied. These epidemics were found to be gradually dying down, which was manifested by progressively decreasing morbidity rate, the frequency and intensity of seroconversions, as well as by a decrease in the duration of the epidemic period. Changes in the biological properties of influenza A (H1N1) virus were accompanied by changes in its antigenic properties. The drift of neuraminidase in the influenza A (H1N1) virus of 1981 towards increased relationship with neuraminidase in the virus of 1952 was observed, while hemagglutinin in the strains of each of these two groups retained its individual character.
Assuntos
Surtos de Doenças/epidemiologia , Vírus da Influenza A Subtipo H1N1 , Vírus da Influenza A/patogenicidade , Influenza Humana/epidemiologia , Adolescente , Adulto , Anticorpos Antivirais/análise , Criança , Pré-Escolar , Testes de Inibição da Hemaglutinação , Hemaglutininas Virais/análise , Humanos , Lactente , Vírus da Influenza A/imunologia , Influenza Humana/imunologia , Neuraminidase/imunologia , Federação RussaRESUMO
As the result of epidemiological and virological observations, the factors which determined the duration of carriership at the period of mixed influenza A and B epidemic were established. Most children released influenza virus A for 7-9 days and influenza B virus for 10-12 days. The duration of carriership in children depended on their age, the level of humoral antibodies in their sera taken before the disease and the manifestation of their immune reaction to influenza virus infection.
Assuntos
Influenza Humana/etiologia , Adolescente , Anticorpos Antivirais/análise , Portador Sadio/imunologia , Portador Sadio/microbiologia , Criança , Pré-Escolar , Humanos , Lactente , Vírus da Influenza A/imunologia , Vírus da Influenza A/isolamento & purificação , Influenza Humana/imunologia , Influenza Humana/microbiologia , Fatores de TempoAssuntos
Infecções Respiratórias/epidemiologia , Adolescente , Adulto , Clima , Humanos , Estações do Ano , Sibéria , Fatores de Tempo , MigrantesAssuntos
Surtos de Doenças/epidemiologia , Influenza Humana/epidemiologia , Adolescente , Adulto , Criança , Pré-Escolar , Humanos , Lactente , Vírus da Influenza A/isolamento & purificação , Influenza Humana/microbiologia , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , U.R.S.S.Assuntos
Amantadina/uso terapêutico , Infecções Respiratórias/tratamento farmacológico , Viroses/tratamento farmacológico , Anticorpos Antibacterianos/análise , Anticorpos Antivirais/análise , Avaliação de Medicamentos , Humanos , Mycoplasma pneumoniae/imunologia , Pneumonia por Mycoplasma/tratamento farmacológico , Pneumonia por Mycoplasma/imunologia , Infecções Respiratórias/imunologia , Viroses/imunologiaRESUMO
The study of immunological changes in convalescents after influenza aged 7-12 months and 18-23 years was carried out in the period of circulation of influenza A/Hong Kong virus and its antigenic variants (1969-1980). A continuous decrease of the immunogenic activity of the causative agents of repeated epidemics and the intensity of the acquired immunity in adult convalescents was demonstrated in successive epidemics of influenza A/Hong Kong. This regularity was fully confirmed in groups of 7 - 12-month-old infants without previous exposure to influenza infection who experienced the disease. Marked differences in the incidence and clinical severity of earlier and later epidemics of influenza A/Hong Kong and changes in immunogenic activity suggest that they are associated with different virulence of the causative agents at different periods of a general pandemic cycle.