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Biomedical subjects

C B Hall

Publications and source records attributed to C B Hall.

190 records · Page 11Linked to original sources
PubMedDate not supplied

Different antiviral spectra of human macrophage interferon activities.

The antiviral activity of alpha-interferon (IFN-alpha) produced by human leukocytes in response to viral infection has been considered to be independent of the virus which induced its production. Recently, however, IFN-alpha has been found to include at least eight different subtypes, as indicated by measurement of antigenic variability, DNA hybridization and amino acid sequencing. We considered the possibility that interferon heterogeneity may play a part in enhancing host antiviral defence and now present data suggesting that purified human macrophages, when exposed to different viruses, produce interferons having differing spectra of antiviral activity. These findings may provide a functional correlation for IFN-alpha heterogeneity.

Humans↗
PubMedDate not supplied

Prevention of infections with respiratory syncytial virus: the hopes and hurdles ahead.

Control of infections due to respiratory syncytial virus (RSV) by immunization poses special problems. First, the peak period of serious illness due to RSV is during the first few months of life, and thus a vaccine would have to be administered during the neonatal period. Second, we understand little of the pathogenesis of and immunity to RSV disease in newborns, and an immune reaction may even play a role in the development of the lower respiratory tract disease seen in infancy. Third, immunity to RSV is imperfect even after naturally acquired, severe infection of the lower respiratory tract. Therefore, it is difficult to envision a vaccine that is safe in the infant and that will engender more complete immunity than the disease itself. However, if the goals are limited to protection of certain high-risk groups or to protection of infants during the first year of life only, immunization might be both feasible and effective in reducing the morbidity and mortality associated with this ubiquitous virus.

Antiviral Agents↗
PubMedDate not supplied

Antigenicity and reactogenicity of influenza A/USSR/77 virus vaccine in children--a multicentered evaluation of dosage and safety.

Clinical trials of monovalent A/USSR/77 (H1N1) and trivalent A/USSR/77 (H1N1), A/Texas/77 (H3N2), and B/Hong Kong/72 inactivated influenza virus vaccines were carried out in 358 children and adolescents. Only split-virus vaccines were administered to children younger than 13 years of age. No serious local or systemic reactions were observed among the study participants. Two doses of vaccine containing 7-20 micrograms of the A/USSR/77 (H1N1) viral antigen were required to achieve serum titers of hemagglutinin-inhibiting (HA1) antibody greater than 1:40. However, single doses containing 7-20 micrograms of the A/Texas/77 (H3N2) or B/Hong Kong/72 antigens stimulated serum HAI antibody levels of 1:40.

Adolescent↗
PubMedDate not supplied

Influenza A virus infection imitating bacterial sepsis in early infancy.

Clinical and laboratory data of 12 previously healthy infants under 3 months of age hospitalized for suspected sepsis and subsequently diagnosed as suffering from influenza A viral infection were obtained prospectively during two epidemics of influenza A/Bangkok/H3N2 epidemics. The onset of the illness was generally acute, and the infants presented with high fever, lethargy often alternating with irritability, anorexia and signs of upper respiratory tract infection. History of contact with at least one person with signs and symptoms consistent with viral disease was present in all infants. White blood cell counts were within normal limits. Only one child had pneumonia and all had normal cerebrospinal fluid findings. Viral diagnosis was made by immunofluorescent testing of nasopharyngeal specimens within several hours of admission in 7 of the 9 infants tested and was isolated within 5 days from admission in 6 of 10 infants. Increasing awareness of the possible viral etiology of acute fever along with a greater availability of rapid viral diagnosis should result in better management of these young infants.

Acute Disease↗
PubMedDate not supplied

Respiratory syncytial virus: its transmission in the hospital environment.

Respiratory syncytial virus (RSV) over the past two decades has been recognized as the most important cause of lower respiratory tract disease in infants and young children. Recently, it has also been identified as a major nosocomial hazard on pediatric wards. The potential for RSV to spread on such wards is underlined by several singular characteristics of RSV. It arrives in yearly epidemics and is highly contagious in all age groups. Immunity is of short duration, allowing repeated infections to occur. Thus, during an epidemic 20--40 percent of infants admitted for other conditions may acquire nosocomial RSV infection, as well as 50 percent of the ward personnel. The usual infection control procedures for respiratory illnesses have had limited success in controlling the spread of RSV. This may be due in part to the modes of transmission of RSV. Inoculation occurs mainly through the eye and nose, rather than the mouth. This may be via large-particle aerosols or droplets, requiring close contact. The virus, however, does not seem capable of traversing distances by small-particle aerosols. Nevertheless, it is able to remain infectious on various environmental surfaces, suggesting fomites as a source of spread. Indeed, inoculation after touching such contaminated surfaces can occur, and may be a major second means of spread, in hospitals as well as in families.

Adolescent↗
PubMedDate not supplied

Communitywide laboratory-based influenza surveillance focused on older persons, 1989-1992.

We collected surveillance data as part of the Medicare Influenza Vaccine Demonstration to describe communitywide epidemiology of influenza, focusing on the elderly. Laboratory-based surveillance was established in medical practices, hospitals, and nursing homes in a two-county demonstration in upstate New York. Time course and intensity of epidemic influenza were compared between counties, between influenza A and B epidemics, and among several levels of surveillance involving elderly persons as well as children during the years 1989-1992. The counties experienced parallel epidemics during each of the three demonstration years. Influenza A/H3N2, predominant in 1989-1990 and 1991-1992, was equally intense among young and old, accounted for 11%-28% of acute cardiopulmonary hospitalizations of older persons, and caused focal outbreaks in 30%-40% of nursing homes in the respective epidemics. Influenza B, predominant in 1990-1991, showed modest impact among the elderly as compared with children. Influenza A/H1N1 occurred among children each year but was virtually absent among the elderly. Systematic surveillance during the "influenza season" consistently confirms widespread infection among older patients, both in the community and in institutions. However, much febrile respiratory illness in this age group during periods of epidemic influenza is culture-negative for influenza virus and thus may be caused by other respiratory pathogens.

Aged↗