Seasonal and areal features of the lagoonal environment in Lake Nakanoumi,a shallow coastal lagoon in Japan

Lake Nakanoumi is a shallow coastal lagoon connected with the Japan Sea by a narrow channel. Over the past decade, land reclamation resulted in a 33% reduction of the lagoon's surface area. The remaining water basin of Lake Nakanoumi is scheduled to be artificially freshened to supply irrigation water for the newly reclaimed lands. This paper deals with the seasonal and areal features of the lagoonal environment prior to the beginning of the artificial desalinization.     

Simultaneous determination of triazolo-benzophenone [2′,5-dichloro-2-(3-glycylaminomethyl-5-methyl-4H-1,2,4-triazol-4-yl)-benzophenone] and its major blood metabolite, triazolam, in monkey plasma by electron-capture gas—liquid chromatography

A gas—liquid chromatographic method for the simultaneous determination of triazolobenzophenone [2′,5-dichloro-2-(3-glycylaminomethyl-5-methyl-4H-1,2,4-triazol-4-yl)-benzophenone, TB] and its major blood metabolite, triazolam, 8-chloro-6-(o-chlorophenyl)-1-methyl-4H-s-triazolo[4,3-a][1,4]benzodiazepine (TZ), in monkey plasma was developed. Decomposition of TB was observed during gas—liquid chromatography. In alkaline medium, TB in plasma was submitted to ring closure reaction to yield triazolo-aminoquinoline, [4-amino-7-chloro-5-(2-chlorophenyl)-1-methyl-4H-s-triazolo[4,3-a]quinoline (TAQ), while TZ remained unaffected, and TAQ and TZ in the benzene extract were assayed by gas—liquid chromatography using an electron-capture detector. The concentration ranges studied were from 5 to 40 ng of TB per 0.5 ml of plasma and from 2 to 20 ng of TZ per 0.5 ml of plasma. This method could be applied to the determination of the plasma levels of TB and TZ in monkeys following intravenous administration of a single 0.2 mg/kg dose of TB.     

Indole-3-acetaldehyde oxidase of pea seedlings

Indole-3-acetaldehyde oxidase was partially purified from the epicotyl of Pisum satiyum seedlings by column chromatography using CM-Sephadex and Sephadex G-150. The enzyme was only active in the presence of molecular oxygen. The activity was maximal at pH 8.0, and the Km value for indole-3-acetaldehyde was 1.4 × 10⁻³ M . The enzyme was inhibited strongly by p -hydroxymercuribenzoate, cyanide and hydroxylamine, suggesting that it contains sulfhydryl group(s) and a metal component such as iron.     

Auxin-induced changes in the cell wall structure: Changes in the sugar compositions, intrinsic viscosity and molecular weight distributions of matrix polysaccharides of the epicotyl cell wall of Vigna angularis

Rapid effects of indole-3-acetic acid (IAA) on the mechanical properties of cell wall, and sugar compositions, intrinsic viscosity and molecular weight distribution of cell wall polysaccharides were investigated with excised epicotyl segments of Vigna angularis Ohwi et Ohashi cv. Takara.

• 1 IAA caused cell wall loosening as studied by stress-relaxation analysis within 15 min after the IAA application.
• 2 IAA stimulated the decrease in the content of arabinose and galactose in the hemicellulose 1 h after its application. The amounts of other component sugars in the cell wall polysaccharides remained constant during the IAA-induced segment growth.
• 3 The intrinsic viscocity of the pectin increased as early as 30 min after the IAA application. This effect was not prevented when elongation growth of the segment was osmotically suppressed by 0.15 M mannitol.
• 4 Gel permeation chromatography of the pectin on a Sepharose 4 B column demonstrated that IAA caused increase in the mass-average molecular weight of the pectin. Analysis of the sugar compositions of the pectin eluted from the Sepharose 4 B column indicated that IAA increased the molecular weight of the polysaccharides composed of uronic acid, galactose, rhamnose and arabinose. This effect became apparent within 30 min after the IAA application. Furthermore, IAA increased the molecular weight of the pectin when elongation growth of the epicotyl segments was osmotically suppressed by 0.15 M mannitol.
• 5 Hemicellulose of the cell wall chromatographed on a Sepharose CL-4 B column. Analysis of the neutral sugar compositions and the iodine staining property (specific for xyloglucans) of the polysaccharide solution eluted from the column indicated that the hemicellulose consisted of xyloglucans, arabinogalactans and polysaccharides composed of xylose and/or mannose. IAA caused a decrease in the arabinogalactan content and depolymerization of xyloglucans. These IAA effects became apparent within 30 min after the IAA application. These changes occurred even when elongation growth of the epicotyl segments was osmotically suppressed by 0.15 M mannitol.

Polymerization of the pectin, degradation of arabinogalactans and depolymerization of xyloglucans appear to be involved in the mechanism by which IAA induces cell wall loosening and therefore extension growth of cells.     

A Study on the Mechanism of Nodding Initiation of the Flower Stalk in a Poppy, Papaver Rhoeas L.

A study was made to find whether the nodding of the flower stalkin a poppy, Papaver Rhoeas L., immediately after its formationwas triggered by the weight of its flower bud or by positivegeoreaction and the following results were obtained.

1. The direction of the nodding was mostly toward the inclinedside of the stalk, which was opposite the leaf, for apical flowerbuds.
2. If the weight of the flower bud at stage 1 was cancelledbyapplying a load equivalent to the bud weight, the noddingofthe stalk was not initiated.
3. The stalk at stages 1 and2 and the upper part of the stalk(bending zone), as comparedwith the basal part, at later stageswere highly deformableaccording to measurements by the bendingmethod.
4. The cellwall of highly deformable stalks was rich in hemicellulosesand that of the basal part was abundant in pectic substances.

From these results, we concluded that the initiation of thenodding in the flower stalk was caused by the weight of theflower bud and positive geotropic reaction was probably notinvolved. (Received December 22, 1980; Accepted January 26, 1981)     

Fluid-dynamical study of protoplasmic streaming in a plant cell

A mathematical model of protoplasmic streaming in a plant cell such as Nitella and Chara is studied. General rheological equations for the non-Newtonian fluid is derived theoretically, and the boundary value problem for the model is solved. The pattern of motion of cytoplasm in a living cell is obtained, and the rheological property of protoplasm is evaluated in vivo.     

N-oxidation of imipramine by isolated perfused rat and rabbit lung

Pulmonary uptake and metabolism of imipramine (IMP) was investigated in isolated perfused rat (IPrL) and rabbit (IPRL) lung preparations. Perfusate containing ¹⁴C-IMP (1.2 μmole/g lung) was recirculated through the pulmonary artery in artificially ventilated lungs. The radioactivity in the perfusate declined rapidly and about 80% of the dose was taken up by the lungs within 10 minutes in both IPrL and IPRL preparations. A steady-state was apparently reached thereafter in the IPRL, while a portion of the radiolabel effluxed into the perfusate of the IPrLs, thus reducing the net lung content to 54% of added IMP by 60 minutes. After 60 minutes perfusion, metabolites of IMP accounted for the major radioactivity (80%) in the perfusate, while the lung contained mainly (83%) the unchanged parent compound. The principal metabolite was identified as IMP-N-oxide (IMP-NO) which was found in the perfusate after 5 minutes of perfusion. Only 3% of the added IMP was metabolized by IPRL in 60 minutes. SKF-525A, an inhibitor of cytochrome P-450-mediated monooxygenase system, did not inhibit but enhanced the metabolism of IMP by IPrL to IMP-NO. IMP was principally metabolized to IMP-NO by incubations of 9,000 g supernatant fractions of rat lungs to a significantly higher extent than similar rabbit lung preparations. Including SKF-525A significantly accelerated the metabolism of IMP to IMP-NO in accordance with the perfusion experiments. These results suggest that in contradiction to publishedd reports, IMP is appreciably metabolized by the rat lung $\text{via}$ N-oxidation by non-cytochrome P-450 pathway and the metabolite formed in the lung is released into the circulation indicating its low affinity for the lung tissue.     

Cartilage-derived factor (CDF) : II. Somatomedin-like action on cultured chondrocytes

Previously, we showed that fetal bovine cartilage contains a polypeptide that stimulates the incorporation of [³⁵S]sulfate into proteoglycans synthesized by rat and rabbit costal chondrocytes in culture. In this paper, we report that the cartilage-derived factor (CDF) increases not only [³⁵S]sulfate incorporation but also [³H]thymidine incorporation into rabbit chondrocytes in monolayer culture. The dose-response curve of CDF stimulation of DNA synthesis was similar in profile to that of CDF stimulation of proteoglycan synthesis. In addition, CDF markedly enhanced [³H]uridine incorporation into rabbit chondrocytes and significantly enhanced [³H]serine incorporation into total protein. These findings indicate that fetal bovine cartilage contains a factor that shows somatomedin-like activity in monolayer cultures of rabbit chondrocytes.     

A contractile ring and cortical changes found in the dividing Tetrahymena pyriformis

A contractile ring consisting mainly of microfilaments was found in the fission zone of dividing Tetrahymena pyriformis. Diameters of the microfilaments were widely distributed from 2.5 to 15 nm. Ring-associated structures such as lateral stripes, linkers and beads with siender tails were recognized. Lateral stripes arranged at regular intervals of about 84 nm on some parts of microfilament bundles were found in both tangential and transverse sections, suggesting that they correspond to bands fastening the contractile ring microfilaments. Linkers that connect individual lateral stripes to the epiplasmic layer were present. Beads or beads with slender tails were found to be arranged on some microfilaments.The results of the present paper also indicate that drastic morphological changes occur in the cortex of the fission zone, especially in the epiplasmic layer, accompanying contraction of the division furrow. The epiplasmic layer which was proved to be a compact filamentous network in this study has been known to exist at the periphery of cytoplasm in immediate contact with one of the cell surface membranes, the inner alveolar membrane; however, in the fission zone of the dividing ceil, it was frequently separated from the membrane and subsided into the cytoplasm. The subsided epiplasmic layer was then loosened and dispersed. The subsidence of the epipiasmic layer appears to be caused by the force generated by the contraction of the contractile ring and transmitted with the linkers to the epiplasmic layer. The changes observed in the epiplasmic layer are presumably indispensable for the rigid cortical layer contraction involved in cytokinesis of Tetrahymena.     

The synthesis of 1,6-anhydro-β-d-glucopyranose and d-glucosyl oligosaccharides from maltose by a fungal glucosyltransferase

The formation of 1,6-anhydro-β-d-glucopyranose and several d-glucosyl oligosaccharides has been observed during the action of a purified, fungal glucosyltransferase (EC 2.4.1.24) on maltose. Such products are synthesized by a transglucosylation mechanism involving the formation of a d-glucosyl-enzyme complex and the displacement of the d-glucosyl group by appropriate acceptor-substrates. The formation of the 1,6-anhydro bond is a novel type of transfer reaction and occurs by displacement of the enzyme from the d-glucosyl-enzyme complex by the proton of the primary hydroxyl group of the same glucosyl group. This reaction is characterized by inversion of configuration at the position of glucosidic bond-cleavage of the substrate. Synthesis of the d-glucosyl oligosaccharides occurs by displacement of the d-glucosyl groups from the enzyme by suitable acceptor-substrates. In these cases, the reactions are characterized by retention of configuration of the d-glucosidic bonds of the substrate. The list of oligosaccharides produced from maltose includes nigerose, kojibiose, isomaltose, maltotriose, panose, isomaltotriose, and 6-O-d-glucosyl-panose. The identity of these compounds has been established by methylation analysis and enzymic hydrolysis. d-Glucose is also a product of the reaction and arises from both the reducing and the non-reducing groups of maltose.