Phloem transport of 14C-labelled assimilates in Ricinus

Summary Exudate can be obtained from incisions made in the bark of the stem of actively growing Ricinus plants. ¹⁴C-labelled assimilates from a fed leaf are rapidly detected in the exudate. This movement was both acropetal and basipetal from the fed leaf, at rates of over 100 cm h^-1. Estimated rates within intact plants were 80–84 cm h^-1.In contrast with xylem sap obtained from the same plant, the exudate obtained had an alkaline pH (8.2), a high dry matter content (10–12.5%), high sugar content (8–10%) which was predominantly sucrose; high potassium content (60–80 mM) and low calcium content (0.5–1.0 mM).It is concluded, on the basis of the present evidence, that the exudate is a true sample of the sieve tube sap undergoing translocation.     

Regulation of Newly Evolved Enzymes. I. Selection of a Novel Lactase Regulated by Lactose in ESCHERICHIA COLI

Thirty-four lactose-utilizing strains of E. coli were selected from a lac Z deletion strain. In 31 of these, the synthesis of the newly evolved lactase is regulated by lactose. The lactase activity in all the strains is indistinguishable from the ebg(+) activity identified by Campbell, Lengyel and Langridge (1973).     

A histochemical study of adenosine triphosphatase and other nucleotide phosphatases in young root tips

Summary The distribution of ATP-ase and other nucleotide phosphatases has been studied in young root tips of maize, barley and broad bean using frozen and paraffin sections stained by standard lead sulphide precipitation procedures. High ATP-ase activity was found at the root and cell surface which is in agreement with previous biochemical studies using excised roots and cell wall preparations. Staining was also found in the nuclei and at particulate sites in the cytoplasm. Differences were observed between the present work and the staining pattern obtained for -glycerophosphatase, and between ATP-ase staining in the three roots studied. These results are discussed in relation to the possible physiological activity of the enzymes and to the differences found between earlier histochemical studies of ATP-ase activity.Abbreviations F.L. frozen longitudinal - F.T. frozen transverse     

Critical study of 5% guanethidine in ocular manifestations of Graves's disease

Assessment was made of 5% local guanethidine in treating eye manifestations in euthyroid patients with either treated thyrotoxicosis or ophthalmic Graves''s disease. In a double-blind crossover study guanethidine caused greater improvement in lid retraction than a control solution. A long-term study showed that this improvement was maintained. A much lower incidence of side-effects was noted with 5% guanethidine than with 10% solution.     

Morphological, Cultural, Biochemical, and Serological Comparison of Japanese Strains of Vibrio parahemolyticus with Related Cultures Isolated in the United States

Morphological, cultural, biochemical, and serological characteristics of 79 strains of Vibrio parahemolyticus isolated from patients suffering from gastroenteric disease in Japan were compared with 17 suspected V. parahemolyticus cultures isolated from wound infections and 14 nonpathogenic vibrios isolated from an estuarine environment in the United States. These groups were differentiated on the basis of several key reactions which included: the range of growth temperature and salt tolerance; the production of catalase and acetoin; the hydrolysis of starch; the fermentation and utilization as single carbon source of sucrose, cellobiose, and arabinose; and the ability to swarm on 1% agar. The separation of the groups on the basis of cultural and biochemical analyses was confirmed by means of slide agglutinations with specific anti-K antisera. The results of this study strongly suggest that the wound infection isolates are V. parahemolyticus species which are easily distinguished from the nonpathogenic estuarine vibrios.