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J E Craighead

Publications and source records attributed to J E Craighead.

137 records · Page 8Linked to original sources
PubMed1967

Effect of polycations on growth and dissemination of the encephalomyocarditis virus in mice.

Pathogenicity of the encephalomyocarditis (EMC) virus for adult mice was increased when polycations of diverse type were mixed with virus and inoculated by the subcutaneous or intraperitoneal routes. Diethylaminoethyl (DEAE) dextran, hexadimethrine (polybrene), polymyxin B, polylysine, and calf thymus histone in various concentrations stimulated multiplication of virus in tissues at the injection site and enhanced entry of virus into the blood. The nonpathogenic r(+) variant of EMC which grows locally in tissues but fails to disseminate after subcutaneous and intraperitoneal inoculation was used in most experiments. This virus caused viremia and fatal central nervous system disease only when the polycations were included in the inoculum. DEAE dextran and polybrene stimulated the release of interferon in infected tissues but had no effect in the absence of virus multiplication. Histological studies of tissues from the injection site showed that polycations provoke a mononuclear cell reaction and alter the integrity of connective tissue. However, the mechanism by which the substances enhance virus growth and dissemination was not defined.

Amino Acids↗
PubMed1966

Growth of Myxovirus parainfluenza type 3 in organ cultures of guinea pig tissue.

Craighead, J. E. (Harvard Medical School, Boston, Mass.). Growth of Myxovirus parainfluenza type 3 in organ cultures of guinea pig tissue. J. Bacteriol. 92:751-761. 1966.-Organ cultures of adult guinea pig nasal mucosa, lung, and pleura were infected with Myxovirus parainfluenza type 3. Observations were made on the growth of virus at intervals after inoculation. An inoculum of 10(2.5) tissue culture infectious doses (tcid(50)) initiated infection in each of the tissues. Cultures of nasal mucosa yielded up to 10(6.0)tcid(50) per 6 hr for periods of as long as 2 weeks. Virus production was not affected by the "immune" status of the animal used as a source of tissue. Introduction of antiserum into the medium appeared to suppress virus release but failed to "cure" the infection. Interferon was not detected in fluids bathing the nasal mucosa. Cultured fragments of lung produced virus for 28 days after inoculation. As much as 10(5.0)tcid(50) per 6 hr was released by the tissue. Pleural mesothelial cells lining the diaphragm yielded up to 10(6.0)tcid(50) per 6 hr over a 14-day period. Histological sections showed that the tissues retained differentiated morphological features during maintenance in vitro. Cytological changes unequivocally associated with infection were not recognized. The techniques described give reproducible, quantitative results. Organ cultures are feasible for the study of virus growth and cytopathology in differentiated tissues.

Animals↗
PubMedDate not supplied

Cryptic pulmonary lesions in workers occupationally exposed to dust containing silica.

Fibrotic lesions associated with deposits of crystalline silica were found postmortem in the lungs of 15 granite workers who lacked radiological evidence of pneumoconiosis. All members of this occupational group had been employed in the granite quarrying and monument industry of Vermont since ambient air-dust standards were introduced in 1937. Although particulate silica was not revealed in the lesions by traditional polarization light microscopy, it was identified by scanning electron microscopy in conjunction with backscatter imaging and x-ray spectrometry. The etiologic basis of the fibrotic pulmonary disease would not have been diagnosed without the aid of these modern analytical tools. Exposure to silica-containing dust can result in cryptic pulmonary disease that is not detectable radiologically. In these retrospective postmortem studies, it was not possible to define the distribution of the lesions in the lungs.

Adult↗