Search PubMed⌕ Search

Biomedical subjects

G W Fernald

Publications and source records attributed to G W Fernald.

At least 19 recordsLinked to original sources
PubMed1989

Epidemic pneumonia in university students.

Longitudinal surveillance of pneumonia in a university student health service was conducted from 1965-1971 and 1984-1987. Of 104 pneumonia cases documented by chest x-ray, only six were presumed to have bacterial etiology; the remaining 98 were characteristic of atypical pneumonia syndrome. Mycoplasma pneumoniae was the etiology in 51% of the pneumonias in the 1960s and 13% in 1984-1987. Pneumonia incidence was highest in the fall semester in seven of 11 years studied. Annual incidence followed a three- to four-year periodicity. Both of these observations mirror the epidemiology of M. pneumoniae in the world population. Symptoms of cough, headache, malaise, and absence of the physical finding of wheezing were seen more consistently in M. pneumoniae pneumonia than in other atypical pneumonias; other clinical features varied among epidemics. Rapid cold agglutinin tests were positive in 27% of our clinically diagnosed pneumonias and in 36% of those with documented mycoplasmal infections. This study appears to provide a basis for predicting future epidemics of atypical pneumonia in student populations.

Adult↗
PubMed1976

Effect of passive antibody on parainfluenza virus type 3 pneumonia in hamsters.

Both parainfluenza virus type 3 and respiratory syncytial virus may produce life-threatening pneumonia or bronchiolitis in infants less than 6 months old. Almost all infants in this age group possess passively acquired maternal antibodies to both viruses. It has been suggested that maternal antibodies may actually participate in the pathogenesis of these diseases in early infancy. This investigation examined the effect of moderate levels of passive antibody on the development of pneumonia in hamsters infected intranasally with parainfluenza virus type 3. The pneumonitis produced in this model was not enhanced by the presence of moderate levels of serum antibody to this virus. Furthermore, reinfection after an initial "sensitizing" infection under the cover of passive antibody did not result in a more severe pneumonitis. These studies do not support either of the two hypotheses that have been advanced to explain the pathogenesis of infections with respiratory syncytial virus in early infancy.

Animals↗
PubMed1975

Acute respiratory disease of university students with special reference to the etiologic role of Herpesvirus hominis.

Infections with Herpesvirus hominis type 1 were associated with 11.5% of acute respiratory illnesses of university students who were admitted to the student infirmary over a 6-year period. Over three-quarters of these infections were detected in students with pharyngitis or tonsillitis; 42% had ulcerated lesions on tonsils or posterior pharynx but only 11% had lesions in the anterior portion of the mouth or lips. Almost all of the H. hominis infections were accompanied by significant rises in neutralizing antibodies and few students had detectable antibodies in the initial serum collected during the acute phase of illness. Special studies revealed herpes-specific IgM antibodies in the early convalescent sera of some of these patients. The data demonstrate that 80% of the infections detected were primary infections with H. hominis. Only 30% of university students possessed neutralizing antibodies to H. hominis and about 10% of those without antibodies acquired antibodies each year. These data suggest that the majority of persons from middle income families reach young adulthood without acquiring infections of H. hominis and the spread of the virus requires close and intimate contact.

Antibodies, Bacterial↗
PubMed1975

Respiratory infections due to Mycoplasma pneumoniae in infants and children.

Systematic monitoring of infants and children in a day-care center revealed infection with Mycoplasma pneumoniae to be more common than expected. Most of these infections were asymptomatic (74%) or associated with mild, nonspecific coryza and cough. Infected children ranged in age from 2 months to 8 years. Complement-fixing and growth-inhibiting antibodies in serum tended to wane rapidly and reinfection was detected in five children after one and one-half to 3 years. In vitro lymphocyte studies revealed antigen-reactive cells were detectable in few of the children under age 4, but thereafter lymphocyte reactivity was found in 53%. These findings suggest that recurrent, unsuspected M. pneumoniae infections occur during infancy and early childhood and that pneumonic disease, common above age 10 years, is an expression of increasing host immune response to the organism.

Acute Disease↗
PubMed1972

In vitro response of human lymphocytes to Mycoplasma pneumoniae.

In vitro culture and stimulation of human peripheral lymphocytes were employed to investigate the role of cellular immunity in Mycoplasma pneumoniae disease. Subjects with documented natural infections served as donors. The lymphocyte response to whole M. pneumoniae organisms was determined as incorporation of tritiated thymidine in a semimicro culture system. The range of cellular reactivity stimulated by specific antigen was within the range stimulated by phytohemagglutinin. The difference between responses of subjects with documented infection and serologically negative controls was highly significant. Specific reactivity of peripheral lymphocytes correlated closely with the presence of serum growth-inhibiting antibodies, and both persisted for several years following infection. Serum complement-fixing titers correlated well with lymphocyte stimulability during the first year but antibody, as measured by this technique, tended to disappear in later convalescence. In light of previous studies, which revealed a lack of correlation between humoral antibodies and resistance to reinfection, these results suggest that immunity to M. pneumoniae infection is mediated by circulating small lymphocytes.

Antibodies, Bacterial↗