NaturalMycoplasma arthritidis infection in mice

B6C3F₁ mice from a hybrid production colony frequently were serologically positive by enzyme-linked immunosorbent assay (ELISA) and consistently negative by culture forMycoplasma pulmonis. Subsequently, 162 mice were obtained and intensively studied using an expanded group of cultural procedures, ELISA, and histopathology. Lesions attributable to mycoplasma infection were not found, butMycoplasma arthritidis was isolated from 20 mice. TheM. pulmonis ELISA was positive (IgM, IgG, or both) in 113 mice. Selected sera were tested simultaneously in both theM. pulmonis ELISA and in an ELISA usingM. arthritidis antigen, and were found to be positive in both the IgM and IgG classes in both ELISAs. Thus, cross-reacting antibody was produced in mice naturally infected withM. arthritidis, confirming previous observations based on experimental infections. To our knowledge, this is the first report of naturalM. arthritidis infection in laboratory mice.     

Immune response in human subjects at high altitude

Levels of immunoglobulins were determined in persons exposed to high altitude. The individuals studied included high altitude natives, sea level residents at high altitude for 2 years, and recent arrivals at high altitude. Increased IgG and IgA levels were found in high altitude natives and sea level residents at high altitude for 2 years when compared with sea level residents. In recent arrivals marked increase of IgG and IgG levels and slight rise in IgM was seen. Recent arrivals who suffered from high altitude pulmonary oedema showed marked elevation of IgG, IgM, and IgA. Immunoglobulin responses to both primary and secondary TAB inoculation were of a higher magnitude and more sustained at high altitude than at sea level.     

Biological control of the weed,Chromolaena odorata [Asteraceae], byPareuchaetes pseudoinsulata [Lep.: Arctiidae] on Guam and the northern Mariana Islands

Chromolaena odorata L. is a major weed of tropical plantations and pasture lands.Pareuchaetes pseudoinsulata Rego Barros [Lep.: Arctiidae] was mass-reared and released to control the weed on the Mariana Islands of Guam, Rota, Tinian and Saipan in the western Pacific. One year following establishment ofP. pseudoinsulata on Guam, the weed was reduced 100% at 3 of 4 sites monitored with fixed quadrats. Seed production was prevented if defoliation occurred prior to the beginning of the flowering season. If defoliation occurred shortly after flowering began, the developing seeds were eaten byP. pseudoinsulata or there was a significant reduction in weight and germination of seeds that matured. Eighteen months after establishing on Guam,P. pseudoinsulata had defoliated approximately 25,000 hectares of the weed. This is the 1^st report on the quantitative impact of any control agent forC. odorata, and though the long term effect of the insect is still unknown, these results are encouraging.