经支气管镜气管插管与常规气管插管救治呼吸衰竭对比分析

目的：回顾性分析呼吸机辅助呼吸救治危重呼吸衰竭患者气管插管方式对于救治成功率的影响。方法：我科收治的各种呼吸衰竭患者94例,回顾分析插管方式对于救治成功率、引发心跳骤停及其对心肺复苏效果的影响。结果：经纤维支气管镜经口气管插管（35例）与经直接喉镜经口（59例）引发心跳骤停有明显统计学差异（X^2=11．5,v=1,t〈0．001）。经直接喉镜经口气管插管在术前用药与否对引发心跳骤停并无统计学意义,但是对于引发心跳骤停后心肺复苏成功率确有明显统计学意义。结论：经纤维支气管镜气管插管具有较高的安全性,在经直接喉镜气管插管是选择镇静药或浅麻醉药物应慎重,尽力避免心跳骤停和心肺复苏失败。     

Effect of lyophilization on the nitrogenase activity of Azotobacter vinelandii]

The activity of nitrogenase in the cells of Azobacter vinelandii grown from lyophilized and non-lyophilized cultures depends on the donor of hydrogen and the concentration of oxygen in the gaseous phase. The lyophilized cells are more sensitive to oxygen (O2 optimum for nitrogen fixation is ca. 1 percent) than the non-lyophilized cells (ca. 5 percent). The determination of acetylene reduction in the course of the culture growth has shown that nitrogen fixation in the lyophilized cells takes place after a lag-period (about six hours) at a rate lower than that of the non-lyophilized cells. The results obtained suggest that lyophilization increases the sensitivity of the cells to oxygen and decreases their nitrogenase activity which is however restored after a while.     

Laboratory scale photobioreactor

Summary A photobioreactor using three concentric glass cylinders, with a light source mounted on the axis within them is described. The space between two innermost cylinders is used as a waterjacket, while the culture of phototrophic microorganisms is in the chamber between the outer cylinder and the middle one. This chamber is also equipped with a stirrer. Rhodobacter capsulatus has been grown in the device at biomass concentration up to 550 mg/l without light limitation.     

Superoxide dismutase and catalase in the protection of the proton-donating systems of nitrogen fixation in the blue-green alga Anabaena cylindrica.

1. Superoxide dismutase activity was present in the heterocysts and vegetative cells of Anabaena cylindrica, but was always lower in the heterocysts. 2. No qualitative differences were found in the superoxide dismutase from the two cellular types. 3. Catalase activity was also present in both cellular types. 4. Most of the NADP reductase activity, as assayed with menadione or ferredoxin as electron acceptor, was localized within the heterocysts. 5. Studies on H2 consumption showed that most of the hydrogenase activity was associated with the heterocysts. 6. The results are discussed in terms of the postulate that superoxide dismutase and catalase are involved in the protection of the proton-donating systems participating in N2 fixation and H2 metabolism of heterocysts.     

Hydrogenases of phototrophic microorganisms

This review surveys recent work done in the laboratory of the author and related laboratories on the properties and possible practical applications of hydrogenases of phototrophic microorganisms. Homogeneous hydrogenase preparations were obtained from purple non-sulfur (Rhodospirillum rubrum S1, Rhodobacter capsulatus B10) and purple sulfur (Chromatium vinosum D, Thiocapsa roseopersicina BBS) bacteria, and from the green sulfur bacterium Chlorobium limicola forma thiosulfatophilum L; highly purified hydrogenase samples were prepared from the cyanobacterium Anabaena cylindrica and from the green alga Chlamydomonas reinhardii. It was shown that hydrogenases of R. capsulatus and T. roseopersicina contain Ni and Fe-S cluster. The cytochromes of the c or b type serve as native electron acceptors for the hydrogenases of the purple bacteria and cyanobacteria; rubredoxin or cytochrome c for the hydrogenase of the green sulfur bacterium; and ferredoxin for Ch. reinhardii hydrogenase. The hydrogenase of T. roseopersicina BBS reversibly activates H2 at Eh less than -290 mV (pH 7), whereas those from R. capsulatus and from C. limicola f. thiosulfatophilum exhibit their maximum activity at Eh greater than -300 mV and are thus favourable only for the H2 uptake. Hydrogenase synthesis in different phototrophs depends on pO2, H2 concentrations and organic substrates. Organic compounds, which serve as electron donors and carbon sources, repress hydrogenase synthesis in R. rubrum, R. capsulatus and in Ectothiorhodospira shaposhnikovii when present at high concentrations. The synthesis of T. roseopersicina hydrogenase is constitutive. H2 notably stimulates hydrogenase activity in R. capsulatus. The synthesis of hydrogenase in R. sphaeroides 2R occurs only in the presence of H2 and does not depend on the presence of organic compounds in the medium.     

Occurrence of plant hormones in cells of the phototrophic purple bacterium Rhodospirillum rubrum 1R

Abstract Plant hormones from biomass of the purple non-sulfur bacterium Rhodospiririllum rubrum were isolated for the first time. These compounds show high physiological activities (300–330%) in the cytokinin bioassay. All three detected cytokinins are adenine derivatives, according to spectral analysis. One of them was identified as 6-(4-hydroxy-3-methyl-2-trans-2-bytenylamino)-9-ß-D-ribofuranosylpurine (zeatinriboside) as shown by thin-layer chromatography and reversed-phase high-performance liquid chromatography. The possible functions of bacterial cytokinins are also discussed.     

Optimizing the Conditions of Dextran Synthesis by the Bacterium <Emphasis Type="Italic">Leuconostoc mesenteroides</Emphasis> Grown in a Molasses-Containing Medium

Maximal dextran production (54–55 g/l) by the bacterium Leuconostoc mesenteroides strain V-2317D was observed in molasses-containing media in the presence of 17.5% glucose at pH_init 6.75. The beginning of dextran production depended on the amount of inoculate; maximum yield was observed at a shaker rate of 200 rpm. The dextran produced by L. mesenteroides grown in the molasses-containing medium was representative of three fractions differing in molecular weight and composition: the high-(∼54.5%), medium- (∼ 27.9%), and low-molecular-weight (∼2.85%) fractions.__________Translated from Prikladnaya Biokhimiya i Mikrobiologiya, Vol. 41, No. 4, 2005, pp. 409–413.Original Russian Text Copyright © 2005 by Vedyashkina, Revin, Gogotov.