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Biomedical subjects

M S Reid

Publications and source records attributed to M S Reid.

61 records · Page 4Linked to original sources
PubMed1972

Effects of ethylene on potato tuber respiration.

Treatment of potato tubers (Solanum tuberosum L.) with ethylene gas causes a rapid rise in their respiration rate, reaching 5 to 10 times the rate of untreated tubers over 30 hours of treatment and then falling slowly. The response shows a lag of 8 hours, and more than 24 hours of exposure is required for maximum effect; the temperature optimum is near 25 C. In sensitivity to low concentrations and dependence on temperature, the phenomenon is similar to the effect of ethylene on the respiration of climacteric and nonclimacteric fruits. Treated potato tubers returned to air recover their sensitivity to ethylene more slowly than do nonclimacteric fruits (e.g., mature green oranges). It is proposed that the respiratory rise characteristic of ripening in climacteric fruits and of the wound response in plant tissues is induced by a rise in endogenous tissue ethylene.

Journal Article↗
PubMed1970

Response of Spirodela oligorrhiza to Phosphorus Deficiency.

The duckweed Spirodela oligorrhiza, growing in sterile defined nutrient media, was used to study some responses of plants to phosphorus deficiency. On a phosphate-deficient medium, growth of Spirodela soon slowed and eventually ceased. Older leaves became chlorotic, but newly formed leaves were dark green and contained much anthocyanin. The photosynthesis rate fell gradually, roots elongated, and chloroplasts became filled with starch.NITROGEN METABOLISM WAS NOT MARKEDLY AFFECTED: the total protein content changed only slightly, and, although levels of glutamine and asparagine increased, the concentrations of the other amino acids remained constant. The effects of phosphorus deficiency on Spirodela are discussed in relation to those found in other higher plants.

Journal Article↗
PubMedDate not supplied

Yaws in Papua New Guinea: extent of the problem and status of control programs.

Yaws was a significant health problem in Papua New Guinea until the nationwide total mass treatment campaign, which took place from 1953 to 1958. The number of cases reported annually fell to less than 300 during the 1960s. In the early 1970s outbreaks occurred in East New Britain and Bougainville but were effectively controlled. A larger outbreak in 1977-1978 on Karkar Island was more difficult to bring under control despite the clinical appearance of the cases, which were less florid than those seen in the 1950s. The latter outbreak raised questions about decreased response to penicillin, lack of ability to develop effective immunity, and increased susceptibility to yaws. Smaller outbreaks were reported in 1983 and 1984 in remote areas, but the current extent of yaws in Papua New Guinea is not fully known. Action is being taken to rectify this situation and to ensure that reports of yaws are fully investigated and that cases are properly managed.

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