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Biomedical subjects

R M Chanock

Publications and source records attributed to R M Chanock.

At least 253 records · Page 14Linked to original sources
PubMed1975

New complement-fixation test for the human reovirus-like agent of infantile gastroenteritis. Nebraska calf diarrhea virus used as antigen.

A complement-fixation (C.F.) test for the human reovirus-like agent of infantile gastroenteritis has been developed using the serologically related Nebraska calf diarrhoea virus (N.C.D.V.) as antigen. Most infants and children who shed the agent in stools and/or who demonstrated serological (C.F.) evidence of infection with a reovirus-like-particle-positive human stool-filtrate C.F. antigen also demonstrated serological evidence of infection when a concentrated N.C.D.V. preparation was employed AS C.F. antigen. The N.C.D.V., which was previously shown to be related to the human reovirus-like agent, was found to be related antigenically to the epizootic diarrhoea of infant mice (E.D.I.M.) virus also. Studies on the prevalence of C.F. antibody in sera from infants and young children revealed a pattern of rapid acquisition of antibody to both the human reovirus-like agent and the N.C.D.V. as over 80 percent of these individuals possessed antibody to each agent by 36 months of age. A strong positive association was found in the results obtained with the two antigens. The ready availability of cell-culture grown N.C.D.V., and its ability to serve as a "substitute" C.F. antigen for the human reovirus-like agent, should enable the serodiagnosis of many cases of disease due to the human agent and facilitate seroepidemiological studies of such infections. In addition, the observation that a large proportion of individuals infected with the human reovirus-like agent develop serological evidence of infection not only to the human agent but to the calf agent as well may have important implications in the immunoprophylaxis of disease caused by the human reovirus-like agent.

Animals↗
PubMed1975

Pattern of shedding of the Norwalk particle in stools during experimentally induced gastroenteritis in volunteers as determined by immune electron microscopy.

In 11 of 23 volunteers the Norwalk virus-like particle was visualized by immune electron microscopy in at least one stool specimen obtained during the acute phase of experimentally induced nonbacterial gastroenteritis. Examination of multiple stool specimens obtained during the course of illness in these 11 volunteers revealed maximal concentration of Norwalk virus-like particle at the onset of illness and shortly thereafter; in no case was the Norwalk particle visualized in stools obtained before the onset of illness. This finding further suggests that the Norwalk particle was the etiological agent of the Norwalk gastroenteritis outbreak. The limit of reliability of our immune electron microscopy assay system for particle counting was examined.

Antibodies, Viral↗
PubMed1975

Failure of attenuated temperature-sensitive influenza A (H3N2) virus to induce heterologous interference in humans to parainfluenza type 1 virus.

The present investigation was undertaken to determine if a candidate live vaccine virus, influenza A/Hong Kong/68-ts-1 [E] (H3N2), induced heterologous interference against an interferon-sensitive, wild-type, parainfluenza type 1 challenge virus. The parainfluenza virus was administered 7 days after Hong Kong/68-ts-1 [E] virus infection. The clinical response, daily quantitative virus shedding, interferon production, and serum and nasal wash antibody responses were determined in an experimental group (influenza A virus followed by parainfluenza virus) and 10 volunteers in a control group (parainfluenza virus only). The volunteers were selected on the basis of susceptibility to the two viruses, i.e. serum hemagglutination-inhibition antibody titer of is less than or greater to 1:8 for influenza virus and low nasal wash antibody titer (is less than or greater to 1:8) for parainfluenza virus. Despite a 100% infection rate in the Hong Kong/68-ts-1 [E] vaccinees, no heterologous interference was induced against the parainfluenza type 1 virus challenge.

Animals↗
PubMed1975

Transmission of Creutzfeldt-Jakob disease to the stumptail macaque (Macaca arctoides).

The successful transmission of Creutzfeldt-Jakob disease from both affected human and chimpanzee brain to stumptail macaques has been accomplished. The incubation period of 5 yr was the same for both animals; however, the course of the disease was longer in the animal receiving the human brain. In both cases, initial mild symptoms slowly remitted only to reappear some 4 mo later. Muscle biopsies revealed changes suggestive of a mild neuropathy. In addition, there appeared to be an increased ability to incorporate 3H-thymidine in untreated cultures of lymphocytes from peripheral blood.

Animals↗
PubMed1975

Potential of attenuated respiratory syncytial virus vaccine for infants and children.

Respiratory syncytial virus (RSV) disease is a major cause of death and hospitalization in infancy and a frequent cause of morbidity throughout childhood. Serum antibody does not protect as is evident from the study of natural disease and use of killed vaccines. Local antibody responses occur in natural illness. Possibly serum antibody in the absence of local antibody plays a part in illness. We have studied local and serum antibody response to potential attenuated vaccines: a 26 degrees C adapted RSV and a ts mutant RSV. Both produced the desired infection as evidenced by virus recovery, serum and local antibody response. However, both appear to have had residual pathogenicity for young infants. This included mild bronchitis after the 26 degrees C RSV and mild rhinitis, which might be acceptable, but also fever and otitis in one infant after the ts RSV. Also, some of the virus recovered in the ts studies had wild type characteristics. An acceptable RSV vaccine strain will (a) infect without undergoing reversion or other genetic changes, (b) induce resistance to wild type virus, (c) cause no or very mild inflammatory changes such as the rhinitis associated with the vaccines thus far tried.

Administration, Intranasal↗
PubMed1974

Reoviruslike agent in stools: association with infantile diarrhea and development of serologic tests.

Reoviruslike particles were visualized by electron microscopy in stool filtrates prepared from stools of infants and young children with severe acute gastroenteritis. Patients who had such particles in their stools and whose paired acute and convalescent serums were tested developed an antibody response to the reoviruslike agent, which was measured by immune electron microscopy and by complement fixation. The reoviruslike agent was antigenically related to the epizootic diarrhea of infant mice virus and the Nebraska calf diarrhea virus.

Animals↗
PubMed1974

Asymptomatic infection of adult volunteers with a temperature sensitive mutant of Mycoplasma pneumoniae.

Temperature sensitive mutants of Mycoplasma pneumoniae were developed with the expectation that their temperature sensitive defects would restrict replication in vivo at the temperature of the lower respiratory tract, whereas such defects would not seriously impair replication in the cooler environment of the upper respiratory passages. One such ts mutant, ts-H43, which does not replicate at a temperature of 37 degrees or above, although noninfectious for hamsters, infected each of 16 seronegative adult volunteers when given by the intranasal route. The mutant remained genetically stable throughout the course of infection and stimulated a moderate systemic and local antibody response. The mutant was entirely avirulent for the volunteers but appeared to stimulate resistance to subsequent challenge with partially attenuated wild-type (ts(+)) Mycoplasma pneumoniae.

Adult↗