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Biomedical subjects

C S Sun

Publications and source records attributed to C S Sun.

25 records · Page 2Linked to original sources
PubMed1984

Pulmonary deposition and clearance of aerosolized interferon.

Small particle aerosols of a hybrid DNA recombinant human alpha interferon, A/D bgl, and a related DNA recombinant leukocyte interferon, A, were generated and delivered to mice for 23.5 h a day for 4 consecutive days. The antiviral activity of these interferons in delivery reservoirs, in the aerosols generated, and in the lungs of test mice was monitored during and after aerosol administration in cytopathic effect inhibition assays, using vesicular stomatitis virus as the indicator virus. In addition, the activity of these interferons in primary mouse embryo cells against influenza A/HK/68 (H3N2) virus was determined. The results obtained indicated that the interferon particles generated in the continuous aerosol therapy system used in these studies remained biologically active and could be readily detected in both aerosol mists and lungs of test mice; levels of exogenous interferon in the lungs equalled or exceeded levels of interferons produced endogenously during experimentally induced influenza virus infection. Titers of the exogenously administered interferons decreased gradually and disappeared from the lungs between 24 and 48 h after cessation of aerosolization. Recombinant human alpha interferon A/D, but not recombinant leukocyte alpha interferon A, significantly inhibited replication of A/HK/68 virus in primary mouse embryo cells in the in vitro studies.

Aerosols↗
PubMed1984

Interferon aerosol suppression of vesicular stomatitis virus replication in the lungs of infected mice.

Mice were inoculated intranasally with vesicular stomatitis virus 16 to 22 h after being exposed to small-particle aerosols of saline, natural mouse alpha interferon, recombinant human alpha interferon A, or hybrid recombinant human alpha interferon A/D bgl for 2, 4, or 8 h. Compared with comparably inoculated, untreated mice, significantly reduced levels of vesicular stomatitis virus were observed in the lungs of animals treated with any interferon preparation for 8 h and in groups treated with mouse alpha interferon or hybrid recombinant human alpha interferon A/D bgl for 4 h. No significant reductions in lung virus titers were observed in any group treated with interferon for 2 h or in any of the groups treated with saline.

Aerosols↗
PubMed1983

Cell-mediated cytotoxic responses in lungs of cotton rats infected with respiratory syncytial virus.

Pneumonia induced in cotton rats (Sigmodon hispidus) after inoculation of respiratory syncytial virus (RSV) was accompanied by the appearance of leukocytes in infected lungs. The number of these leukocytes increased until Day 5 after inoculation when sixfold more leukocytes were recovered from infected lungs using transpleural lavage than were recovered from lungs of uninfected control animals. Although macrophages and lymphocytes constituted approximately 65 and 25%, respectively, of the cells observed in lavage suspensions from both infected and uninfected lungs, only leukocytes in suspensions from infected animals appeared to be activated, as judged by cellular morphologic examination, cytochemical staining, and bactericidal activity. Leukocytes from lungs and adjacent lymph nodes of infected cotton rats, but not similar cells from uninfected animals, caused significant chromium release when they were added to primary cotton rat embryo and Hep-2 tissue culture cells infected with RSV in cytotoxicity assays. Cytotoxic activity peaked 5 days after inoculation, was neither virus-specific nor H-2 restricted, and was associated with both adherent and nonadherent fractions of lung cells. There was a close temporal relationship between the appearance of cytotoxic activity in the lung and termination of virus replication in this organ, suggesting a role for cytotoxic effector cells in recovery from respiratory syncytial virus infection of cotton rats.

Animals↗
PubMed1983

Correlation of cytotoxic activity in lungs to recovery of normal and gamma-irradiated cotton rats from respiratory syncytial virus infection.

Cotton rats (Sigmodon hispidus) that were exposed to 300, 600, or 900 rads of gamma irradiation and inoculated intranasally 2 days later with respiratory syncytial virus (RSV) exhibited prolonged virus shedding and delayed humoral and cytotoxic immune responses compared with comparably inoculated nonirradiated control rats. In nonirradiated animals and in animals exposed to 300 and 600 rads, levels of virus declined and then disappeared from the lungs during the period in which cytotoxic activity was maximal in the lungs of these animals. In contrast, in the group of cotton rats exposed to 900 rads of irradiation, local cytotoxic activity remained low throughout the 11-day observation period, and virus was not eliminated from the lungs. Although virus-neutralizing antibodies in serum and lavage fluids from these animals may have been involved, correlation of antibody concentrations with virus clearance from lungs was not as evident. These data suggest that cytotoxic effector cells have a positive role in eliminating RSV from the lungs of unprimed cotton rats.

Animals↗
PubMed1983

Replication of respiratory syncytial virus in lungs of immunodeficient mice.

Respiratory syncytial virus was frequently isolated during a 10-day test period from the lungs of 4- to 6-week-old immunodeficient nude (nu/nu) mice and from gamma-irradiated C3H mice inoculated intranasally with this virus, but not from similar aged and comparably inoculated normal littermates of these mice. Virus isolation rates and levels of virus in lungs in both groups of immunodeficient mice were similar. No extrapulmonary dissemination of virus was observed in any test group of mice.

Animals↗
PubMed1979

Fine structure of digital vascular lesions in Raynaud's phenomenon and disease.

The ultrastructural changes in the vessels of the fingertips of patients with Raynaud's phenomenon or disease, with or without scleroderma, are described for the first time. Fingertip specimens were taken by punch biopsy. The light microscopic changes, including segmental vasculitis, fibrinoid degeneration of capillaries, and involuntary regression of glomus bodies explain the reduced digital blood flow associated with Raynaud's disease and phenomenon. The moment-to-moment digital blood flow, recorded rheoplethysmographically, was low when the patient was in a comfortable environment and was increased in a hot environment. This result substantiates the therapeutic importance of reflex vasodilatation. These findings correlate well with the ultrastructural changes in capillaries, including multiple cytoplasmic folds in endothelial cells, abundant intracytoplasmic filaments, and unusual incorporation of collagen fibrils in the basement membrane. These changes must influence nutritional and thermoregulatory function of the digital blood vessels.

Adolescent↗