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Query: UMLS:C0021311 (Infection)
 38,178 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Infection of two different lines of polarized epithelial cells grown as monolayers with several types of enveloped viruses results, for each virus type, in a characteristic asymmetric budding of virions. Influenza virus (WSN strain), simian virus 5, and Sendai virus bud exclusively from the free (apical) surface of the cells, while vesicular stomatitis virus acquires its envelope only from the basolateral plasma membrane. Because different viruses select specific domains of plasma membrane in the same cell type, virus-infected epithelial monolayers can provide an excellent model system for studies of the mechanisms that generate regional differences in the distribution of plasma membrane components of epithelial cells.
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PMID:Asymmetric budding of viruses in epithelial monlayers: a model system for study of epithelial polarity. 28 16

Specific cytotoxic thymus-derived (T) lymphocytes were detected in the cervical lymph nodes and spleen during influenza infection of mice. The cytotoxic T cells can distinguish target cells infected with different influenza A subtypes. Infection with parent viruses and their recombinant progeny possessing the hemagglutinin of one parent and the neuraminidase of the other demonstrated that significant cytotoxicity occurred only when the hemagglutinin of the immunizing viruses was the same as that of the virus used to infect the target cell. In addition to this specific cytotoxic response to the major surface antigen, a cross-reactive response could be detected when the relatively nonpermissive L cell was used as the target cell. These results indicate there is a specific cytotoxic T-cell response to the surface hemagglutinin, and a cross-reactive cytotoxic response, not directed to the hemagglutinin, during influenza infection. The cytotoxic T-cell response specific for the hemagglutinin antigen may play an important role in in vivo immunity to influenza.
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PMID:Hemagglutinin-specific cytotoxic T-cell response during influenza infection. 30 10

Infection of mice with subtype A0 OR A2 human influenza viruses, by a non-respiratory route causing no lethality, renders the animals markedly resistant to subsequent respiratory challenge with a strain differing from the first one through its haemagglutinin and neuraminidase antigens. This state of heterotypic immunity which appears rapidly (5 days) after the first infection, manifests itself during the second infection by a much reduced mortality, by less extensive lung lesions than in the control mice and by a final drop in lung virus titre (while in controls this titre stays at a high level until death) associated with a rapid rise of serum antibody levels against the haemagglutinin of the challenge virus and the "soluble" antigen common to type A strains. The development of this state of heterotypic immunity is dependent on the capacity of the first virus inoculated to replicate actively in the mouse. The role played by cell-mediated immunity in this phenomenon is evidenced by the fact that both the induction and the expression of this state of heterotypic resistance may be abolished by treatment of the mice with anti-thymocyte serum, while they are not affected by cyclophosphamide. Furthermore, in the mouse infected with an influenza A0 or A2 virus, it has been possible to demonstrate completely cross-reactive delayed type hypersensitivity reactions against the virions or their products. The fact that heterotypic immunity is not demonstrable between influenza viruses of type A and B favors the hypothesis that an antigen (matrix or nucleoprotein) common to all A subtypes--but different in B type strains--plays a role in these reactions of cross-protection.
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PMID:Heterotypic protective immune reactions in mice infected with distinct serotypes of human influenza virus. 30 87

The growth of parent influenza viruses A/England/939/69 and A/PR/8/34, and clones 6, 7, and 64C, derived by recombination, was studied in newborn rats. Using an inoculum of 10(4.0) EID50, influenza virus A/England/939/69 produced the highest titres of virus in rat turbinates at 48 hours after inoculation; clones 6 and 7 and A/PR/8/34 grew to lower titres; and clone 64C grew to the lowest titre. These differences were less apparent when 10(2.0) EID50 of virus was used as an inoculum, and rats were not infected by smaller inoculum of any of the virus strains. Infection with 10(4.0) EID50 of all viruses produced lung infection; at 48 hours after infection, the highest titres were recovered from rats infected with A/PR/8/34 and A/England/939/69 virus. Prior infection with A/England/939/69 or A/PR/8/34 increased the incidence of bacteraemia and meningitis following intranasal inoculation of Haemophilus influenzae type b; infection with clone 64C did not enhance bacterial meningitis, while infection with clone 6 gave an intermediate result. Volunteer studies with these viruses have shown that influenza virus A/England/939/69 was virulent, clones 6 and 7 were attenuated, clone 64C was over-attenuated, and A/PR/8/34 virus was noninfective for man. The relative titres of virus recovered from turbinates taken 48 hours after infection with 10(4.0) EID50 of virus and the ability of virus infection to enhance bacterial infection correlated with the property of virus attenuation for man for four of the five strains tested; however, no correlation was seen for A/PR/8/34 virus, which is a result also found in other laboratory tests designed to measure virulence for man.
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PMID:Influenza virus infection in newborn rats: a possible marker of attenuation for man. 30 96

The antibody response to a new influenza subunit vaccine was compare d one year after vaccination with the responses induced by two other influenza vaccines. The subunit vaccine was given either in a high dose form containing 2100 IU, or in a low dose form containing 700 IU. As comparison a split vaccine was used containing 800 IU and AI(OH)3 as adjuvant and a whole virus vaccine containing 2100 IU. Of the 399 vaccinated subjects which had taken part in this study 151 were available for hemagglutination inhibiting (HAI) antibody determinations one year after vaccination. Protection rates assessed for the respective groups on the assumption that serum HAI titers of 1 : 32 or greater confer protection. With the high dose of subunit vaccine 85% of volunteers were considered still to have protective titers one year after vaccination, compared with 77% of those who received the whole virus vaccine. Although the high dose subunit vaccine and whole virus vaccine induced similarly high protective levels lasting at least one year, the reactions observed on vaccination were significantly less with the subunit preparation. The lower dose of subunit vaccine induced lower levels of protection (60%) after one year, and lower mean HAI titers than the high dose subunit vaccine. Nevertheless protection was superior to that of the split virus adjuvant vaccine. The addition of adjuvant thus does not seem materially to improve the immune response to influenza virus antigens. An increase of antigen content can however be seen as a practical alternative for achieving higher antibody levels. The subunit vaccine would appear to be particularly suitable in this respect as even with a higher dose there is no increase in reactogenicity.
Infection 1978
PMID:[A new influenza subunit vaccine: hemagglutinating antibodies one year after vaccination (author's transl)]. 36 74

A new influenza subunit vaccine which contains only hemagglutinin and neuraminidase antigens was investigated for reactogenicity and immunogenicity in children aged between three and 15 years. Children under six years of age received either 500 IU or 1000 IU of the commercial vaccine, those aged from six to 15 years either 1000 IU or 2000 IU. The vaccines contained the virus strains recommended by the World Health Organisation for the vaccination season 1976/77. In a double blind study the vaccinees were allocated at random to the different dosage groups. The children were examined for reactions by the vaccinating physician 24 hours after vaccination. Serum hemagglutination inhibiting antibody titers were determined before vaccination and four weeks after vaccination. In the younger age-group additional antibody determination was made two weeks after a booster injection. A very low rate of side-reactions was observed in all dosage groups. The increase of the antigen content was not associated with a higher rate of side reactions. After the first vaccination a significant rise of antibody titers could be observed in all children. After the booster injection a further increase of these antibody titers was observed. The response of the younger age group to the dosages 500 and 100 IU did not different significantly. In contrast, in the older age group the increase of the dosage from 1000 to 2000 IU was connected with a better immune response. This was especially marked in the antibody titers against the influenza B-strain virus.
Infection 1978
PMID:[Vaccination of infants and schoolchildren with an influenza subunit vaccine (author's transl)]. 36 75

A model of salicylate intoxication was developed in ferrets to permit the evaluation of the interaction with viruses isolated from patients with Reye's syndrome. Salicylate intoxication produced a mild elevation of the serum glutamic oxaloacetic transaminase and fatty changes in the liver, but these changes differed from those seen in Reye's syndrome on light and electron microscopy. Salicylates were associated with decreased activity of hepatic phosphorylase and a slight depression of activity or ornithine transcarbamylase, a mitochondrial urea cycle enzyme. Infection with influenza viruses produced mild fatty changes in the liver, but did not significantly potentiate the effects of salicylate intoxication on the over-all mortality, the degree of fatty changes, or the hepatic enzymes. Influenza infection alone was not associated with decreased hepatic phosphorylase activity, but was associated with decreased activity of ornithine transcarbamylase. Influenza A was isolated from the livers of two of four animals cultured in embryonated eggs.
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PMID:Salicylate intoxication and influenza in ferrets. 43 1

The frequency of Legionnaires' disease among 586 cases of pneumonia that occurred in Iowa between fiscal years 1972 and 1977 was studied retrospectively on the basis of paired sera. The frequency of confirmed Legionnaires' disease was 4.1% and of presumptive Legionnaires' disease was 11.4%. Infections with the Legionnaires' disease (LD) bacterium were most frequent in the summer. Of the 22% of pneumonias for which a cause could be defined, Legionnaires' disease was third in frequency behind Mycoplasma pneumoniae and influenza A virus infections. Infections with the LD bacterium occurred in association with pneumonias in most age groups. The youngest patient with LD infection was a 5-year-old boy with pneumonia. The disease occurred 3.2 times more often in males than in females. In males, the frequency of confirmed and presumptive Legionnaires' disease increased steadily to plateau after the fourth decade at about 12% and 28%, respectively. In females the frequency of presumptive Legionnaires' disease was 7% to 16%, relatively evenly distributed over all age groups. Pneumonias associated with LD bacterium infection should be considered in the differential diagnosis of community-acquired pneumonias in most age groups.
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PMID:Legionnaires' disease in pneumonia patients in Iowa. A retrospective seroepidemiologic study, 1972-1977. 43 44

During an outbreak of a mild upper respiratory tract infection in a university children's hospital in Munich, an H1N1 influenza virus was isolated. Serological analysis of the isolate showed that antigenically the virus resembled the USSR/90/77 strain of influenza A virus which has been isolated in many parts of the world during the last two years.
Infection 1979
PMID:Isolation of H1N1 influenza virus in Munich. 43 95

Pulmonary and systemic defenses against hematogenous challenge with 32P-labeled Staphylococcus aureus were measured 10 min, 8 hr, and 24 hr after intravenous injection of the bacteria in a mouse model of influenza virus pneumonia. Infection with influenza A virus did not alter bactericidal defenses in the liver and spleen, but pulmonary bactericidal activity measured 24 hr after infection was suppressed in virus-infected animals; 20% +/- 3% of the initially injected, viable bacteria were recovered from lungs of pneumonitic mice after 24 hr as compared with 9% +/- 1% from lungs of the uninfected mice. These data demonstrate that pulmonary infection with influenza virus does not alter antibacterial defenses of the liver and spleen but does suppress bactericidal activity in the lung.
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PMID:Pulmonary and systemic defenses against challenge with Staphylococcus aureus in mice with pneumonia due to influenza A virus. 45 95


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