Carotid endarterectomy for cerebrovascular insufficiency: long-term results in 592 patients followed up to thirteen years

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The occurrence of a soluble glucose 6-phosphatase in cotyledon tissue of Phaseolus vulgaris during germination

Cotyledon tissue from seedlings of Phaseolus vulgaris at various stages of germination was homogenized and fractionated under isotonic conditions. Measurement of glucose 6-phosphatase (D-glucose 6-phosphate phosphohydrolase, EC 3.1.3.9) activity in the isolated fractions showed an increase in the level of soluble enzyme with advancing age of the cotyledons, such that by late senescence (10 days of age) approximately 90% of the recovered glucose 6-phosphatase was present in the soluble fraction, and its specific activity was about twofold greater than that of the homogenate. The pH profiles of the bound and soluble enzymes were found to be closely similar. The presence of a soluble glucose 6-phosphatase has been interpreted as indicating either de novo synthesis of the soluble form of the enzyme with advancing senescence, or solubilization of normally bound enzyme which may in turn reflect a partial breakdown in the structure of endoplasmic reticulum in senescent cells.

Ethylene production from beta-alanine by an enzyme powder

In the investigation of a pathway for ethylene biosynthesis, intermediates arising from the metabolism of β-alanine-2-14C to ethylene by enzyme powders from wax-bean cotyledons were isolated and identified by paper and thin-layer chromatography. Quantitative determinations of the label have provided evidence for the conversion of β-alanine through malonic semialdehyde, β-hydroxypropionic acid, and acrylic acid to ethylene.