Electrocatalytic dehalogenation of organohalides on a nickel(II) tetraazamacrocyclic complex-modified graphite felt electrode

Electrocatalytic dehalogenation of organohalides was studied using a nickel(II) tetraazamacrocyclic complex-modified graphite felt electrode. The nickel(II) tetraazamacrocyclic complex-modified graphite felt electrode was prepared by attaching nickel(II) (6-(2′-hydroxyethyl)-1,4,8,11-tetraazacyclotetradecane)perchlorate chemically to the carboxyl groups of a thin poly(acrylic acid) layer coated on the graphite felt. The modified electrode gave a reversible electron transfer for the nickel(II)/nickel(I) redox couple in cyclic voltammetry at ?0.95 V versus Ag/AgCl. A preparative electrocatalytic dehalogenation of organohalides was successfully achieved on the modified electrode with an adequate current efficiency (55.6–94.8%), conversion (34.2–100%) and turnover number of the Ni catalyst (667–3333).     

Identification of synaptic activity-dependent genes by exposure of cultured cortical neurons to tetrodotoxin followed by its withdrawal

Activity-dependent gene expression is one of the key mechanisms of synaptic plasticity that form the basis of higher order functions such as learning and memory. In the present study, we surveyed for activity-dependent genes by analyzing gene expression changes accompanying reversible inhibition of synaptic activity by tetrodotoxin (TTX) using two types of DNA microarrays; our focused oligo DNA microarray "Synaptoarray" and the commercially available high-density array. Cerebral cortical cells from E18 rat embryos were cultured for 14 days to ensure synaptogenesis, then treated with 1 muM TTX for 48 hr without detectable effect on cell viability. Synaptic density estimated by the amount of Synapsin I and Synaptotagmin I was decreased 21-24% by TTX treatment, but recovered to the control level 48 hr after TTX withdrawal. Comparison of gene expression profiles by competitive hybridization of fluorescently labeled cRNA from TTX-treated and control cells showed an overall downregulation of the genes on the Synaptoarray by TTX-treatment with different recovery rates after TTX withdrawal. With 16 representative genes, microarray data were validated by real-time PCR analysis. Genes most severely downregulated by TTX and upregulated above the control level at 5 hr after TTX withdrawal were munc13-1 (involved in docking and priming of synaptic vesicles) and Shank2 (involved in the postsynaptic scaffold). In addition, comprehensive screening at 5 hr after TTX withdrawal using high density arrays resulted in additional identification of Rgs2, a regulator of trimeric G-protein signaling, as an activity-dependent gene. These three genes are thus likely to be key factors in the regulation of synaptic plasticity. (c) 2007 Wiley-Liss, Inc.     

Clinical differentiation of atypical pneumonia using Japanese guidelines

BACKGROUND AND OBJECTIVE: Atypical pneumonia occupies an important position in community-acquired pneumonia. The aim of this study was to examine whether making a diagnosis of atypical pneumonia is possible based upon the Japanese Respiratory Society guidelines. METHODS: The data from three prospective studies were reviewed. A total of 285 patients with mycoplasmal pneumonia or chlamydial pneumonia and 515 patients with pneumococcal pneumonia or Haemophilus influenzae pneumonia were assessed to determine whether these pneumonias met the diagnostic criteria for atypical pneumonia used in the Japanese Respiratory Society guidelines. The criteria were: (i) age less than 60 years; (ii) no or only minor underlying diseases; (iii) persistent cough; (iv) limited chest auscultatory findings; (v) no sputum, or no identified aetiological agent by rapid diagnosis; and (vi) a peripheral white blood cell count below 10,000/microL. RESULTS: All items of the criteria proved to be valid except for 'age' in patients with Chlamydophila pneumoniae pneumonia using multiple regression analysis. The sensitivity and specificity for atypical pneumonia were 77.0% and 93.0% based on four or more of the criteria respectively. CONCLUSION: Pure atypical pneumonia can be differentiated to some degree by clinical symptoms and laboratory findings. It is important to differentiate and treat bacterial pneumonia and atypical pneumonia in regions such as Japan, where Streptococcus pneumoniae resistance to macrolides is high. Treatment covering the two types of pneumonia should be considered in elderly patients and those with underlying respiratory disease.     

Prolonged ectopic calcification induced by BMP-2-derived synthetic peptide

Bone morphogenetic protein-2 (BMP-2) promotes the formation and regeneration of bone and cartilage, and therefore constitutes the most promising candidate for a bone repair material. However, it also has a wide range of functions, such as in organogenesis and apoptosis. Therefore, we investigated a novel synthetic peptide corresponding to residues 73-92 of BMP-2. This peptide bound to a BMP-2-specific receptor and elevated both alkaline phosphatase activity and osteocalcin mRNA in the murine cell line, C3H10T1/2. The 73-92 peptide also induced ectopic calcification when conjugated to a covalently crosslinked alginate gel. Here we report that the 73-92 peptide-conjugated alginate gel showed prolonged ectopic calcification for up to 7 weeks in rat calf muscle. In contrast, rhBMP-2-impregnated collagen gel showed maximum ectopic calcification at 3 weeks, and the calcified products that had formed disappeared after 5 weeks. Histological examination showed that the 73-92 peptide-conjugated alginate gel induced many osteoblast-like cells and few osteoclasts. In contrast, rhBMP-2-impregnated collagen gel induced many osteoclasts. These results suggest that the 73-92 peptide on alginate gel remains active at the implanted site, continuously induces differentiation of osteoblast precursor cells into osteoblasts, and activates osteoblasts to promote ectopic calcification.     

Limited role for interleukin-18 in the host protection response to pulmonary infection with Pseudomonas aeruginosa in mice

We report that clearance of Pseudomonas aeruginosa, accumulation of neutrophils, and synthesis of tumor necrosis factor alpha and macrophage inflammatory protein 2 in the infected lung were not largely different in interleukin-18 (IL-18) knockout or transgenic mice compared with control mice. Our results suggest a limited role for IL-18 in the host defense against P. aeruginosa.     

Role of the vestibular system in the arterial pressure response to parabolic-flight-induced gravitational changes in human subjects

This study examined how different weighting coefficients imposed on individual finger force regulate bimanual finger force coordination patterns under the influence of bilateral coupling and visual information of the force output. The weighted sum of the two forces was computed as the total force output to match two target force levels (10% and 35% MVC) in separate conditions, and visual feedback of the total force output was provided in the experiment. The results revealed higher performance error at 35% in comparison with 10% MVC with the greatest error at the unequal coefficient setting. The correlation between the individual forces and the force output ratios correlated nonlinearly with the weighting coefficient ratios; however, the extent of change was much smaller than the coefficient ratios. The results suggest that bilateral coupling and task constraints interact to determine the coordination strategy. The irregularity of the individual finger forces increased with the weighting coefficient while the irregularity of the total force remained the same. The results support the hypothesis that the organization of redundant motor coordination patterns emerges from the interactive effect of the constraints on movement.