For extracting free amino acids from human leukocytes, we find that disruption of the cells by ultrasonication is more reliable than freezing and thawing. The amount of free amino acids extracted by the latter method depends on the temperature and duration of thawing. We extracted free amino acids from leukocytes of healthy men by ultrasonication and compared their concentrations in lymphocytes and granulocytes. The amino acid content of granulocytes significantly (p less than 0.001) exceeded that of lymphocytes. Of the amino acids extracted from granulocytes, 76% was taurine; for lymphocytes taurine, aspartic acid, and glutamic acid were predominant, respectively composing 44%, 17%, and 26% of the total. Taurine is proposed as an index of cell disruption.
The severity of the incidence of the fungal disease, potato scab, varies with different soil groups at the same soil pH. At a soil pH of 5.3, potato scab is easily controlled in soils of western Hokkaido (soil group A) by simply decreasing soil pH, but in soils from eastern Hokkaido (soil group B) it is not so easily controlled. The difference appears to be due to higher levels and exchangeable aluminium in Group A.Addition of sufficient aluminium or ferrous sulfate to a group B soil decreased the incidence of potato scab in a field experiment. Higher levels of aluminium sulfate depressed crop production. It is concluded that aluminium ions control the incidence of potato scab in acid soils. It is suggested that, in soils with low exchange acidity Y1, potato scab can be controlled by adding sufficient aluminium to increase their exchange acidity YI to above 7-8.
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