OBJECTIVE: To evaluate the performance of a hand-held ketone sensor that is able to measure blood beta-hydroxybutyrate (beta-HBA) concentrations within 30 s in patients with diabetic ketoacidosis (DKA) and patients who attend a weight management clinic. RESEARCH DESIGN AND METHODS: Two groups of patients were studied: 19 patients admitted with DKA and 156 patients attending a weight management clinic. Paired capillary and venous whole blood samples were measured using the ketone sensor and also using an enzymatic laboratory reference method. RESULTS: The ketone sensor accurately measured beta-HBA concentrations in patients with DKA (limits of agreement -0.9 to + 1.0 mmol/l) or starvation-induced ketonemia (limits of agreement -0.5 to +0.5 mmol/l). CONCLUSIONS: This ketone sensor accurately measures whole blood beta-HBA concentrations within 30 s.

Two forms of cellulase, buffer soluble (BS) and buffer insoluble (BI), are induced as a result of auxin treatment of dark-grown pea epicotyls. These two cellulases have been purified to homogeneity. Antibodies raised against the purified cellulases were conjugated with ferritin and were used to localize the two cellulases. Tissue sections were fixed in cold paraformaldehyde-glutaraldehyde and incubated for 1 h in the ferritin conjugates. The sections were washed with continuous shaking for 18 h and subsequently postfixed in osmium tetroxide. Tissue incubated in unconjugated ferritin was used as a control. A major part of BI cellulase is localized at the inner surface of the cell wall in close association with microfibrils. BS cellulase is localized mainly within the distended endoplasmic reticulum. Golgi complex and plasma membrane appear to be completely devoid of any cellulase activity. These observations are consistent with cytochemical localization and biochemical data on the distribution of these two cellulases among various cell and membrane fractions.Cellulolytic enzymes (~-l,4-glucan, 4-glucanohydrolase, EC 3.2.1.4) occur in specific locations in tissues of higher plants at particular stages of development. Their possible regulatory roles in cell growth and differentiation (1, 7-10, 12, 14-18), and the hormonal control of their induction (5-8, 21), have been emphasized in earlier work. Although cellulases have been purified and partly characterized (5, 6), their actual localization at the cellular level has not been demonstrated. In elucidating the physiological role of these enzymes, it is imperative that their exact subcellular loci be defined. Attempts made to localize cellulase in higher plants (3, 4) and snail (20) have not met the refinements necessary for precise ultrastructural localization.Auxin-induced growth in etiolated pea epicotyls offers a unique system for localization of cellulases. Two different species of cellulases, one buffer insoluble (Bi) and the other buffer soluble (BS), have been purified and characterized from this system (5, 6). These two proteins have proved to be immunologically different. With the use of ferritin-conjugated antibodies to these two cellulases, an immunocytochemical method was developed to localize the enzymes at subcellular levels. The results were supplemented by cytochemical (4) and cell fractionation procedures. MATERIALS AND METHODS Plant Material and Hormone TreatmentSeeds of Pisum sativum L. var. Alaska were soaked for 20 min in 0.5% sodium hypochlorite. After 8 h of imbibition in tap water, seeds were planted in moistened vermiculite and grown in darkness at room temperature.

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RNA synthesis was studied in Jerusalem artichoke (Helianthus tuberosus L.) tuber slices immediately following excision and during the early period of aging in water. Incorporation of [(3)H]adenosine into RNA was detected as early as 20 min after excision. Measurement of the specific activities of RNA (cpm/μg) and of ATP showed that RNA synthesis proceeded at a constant rate for the first several hours of aging and then increased moderately. [(3)H]adenosine was incorporated into polysomes throughout the aging period examined. Sucrose gradient fractionation of EDTA-dissociated polysomes showed that during the first 2 h of aging most of this incorporation was not into ribosome subunits but into presumed mRNA. Autoradiographic analysis of [(3)H]adenosine labelled nuclei showed that this was caused, at least in part, by a delay in the onset of rRNA synthesis synthesized during this time chromatographed as poly(A)-RNA on oligo(dT)-cellulose, indicating that a large part of the mRNA was not polyadenylated.