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Biomedical subjects

F S Wagner

Publications and source records attributed to F S Wagner.

6 recordsLinked to original sources

Prevention of intravascular thrombus formation on plastic catheters with heparin-benzalkonium complex: in vivo and in vitro studies.

A complex of heparin and a quaternary ammonium compound dissolved in an organic solvent was investigated for its potential ability to prevent clotting on the surface of plastic catheters. Despite the complexing of heparin to ammonium, anticoagulant activity remained on in vitro testing. Both the heparin complex and its organic solvent alone partially prevented catheter thrombus formation when tested in an in vivo animal model system. Neither, however, was totally effective in preventing thrombosis.

Animals

The African green monkey as an alternate primate host for studying Machupo virus infection.

African green monkeys (Cercopithecus aethiops) are highly susceptible to Bolivian hemorrhagic fever (BHF). Six monkeys were inoculated with 1,000 plague-forming units of Machupo virus, the etiologic agent of BHF. They were observed and monitored for clinical signs, body temperature, viremia, hematologic changes, and virus neutralizing antibody. Onset of fever, anorexia, and depression was noted on days 3 to 6 postinoculation. These and other signs increased in severity and all monkeys died: 5 of 6 died by day 13 and one survived until day 24. The median time to death for the group was 12.5 days. The mean value for hematocrit determinations gradually decreased to 30 on day 10 but subsequently increased. Mean neutrophil and lymphocyte values increased slightly until day 3, and then decreased to minimal values of 3,000 and 2,000, respectively, on day 10. Four monkeys were viremic by day 7 and all were viremic on day 10. The monkey that survived until day 24 had a neutralizing antibody titer of 1:32 on day 14 and appeared to recover from the initial acute illness by day 16. It died following onset of severe neurologic signs on day 23. BHF in the African green monkey is similar to the disease described in two species of macaques.

Animals

Pathogenesis of Machupo virus infection in primates.

Experimental Machupo virus infection of rhesus and cynomolgus monkeys produced a severe illness consisting of an initial clinical phase and a later neurological phase. Cumulative mortality during the two phases was 80% and 95% respectively. Attempts to alter the pathogenesis with decomplementation or immunosuppression resulted in earlier deaths of the monkeys.

Animals

Protection of monkeys against Machupo virus by the passive administration of Bolivian haemorrhagic fever immunoglobulin (human origin).

Bolivian haemorrhagic fever immunoglobulin of human origin, given either prior to or shortly after experimental infection with Machupo virus, protected rhesus and cynomolgus monkeys against initial clinical illness. Some survivors developed severe neurological signs 30-47 days after virus inoculation and died 4-6 days later. Results from one of the experiments suggested that the development of neurological signs was associated more frequently with high doses of immunoglobulin than with intermediate or low doses.

Animals