Immunogenicity of a monovalent pandemic influenza A H1N1 vaccine in health-care workers of a university hospital in Japan

A phase III observational study evaluating a single-dose of an inactivated, split-virus, unadjuvanted AH1pdm vaccine in HCW was conducted. A safe and effective vaccine was needed after the emergence of AH1pdm in April 2009. We analyzed the immunogenicity and safety of the vaccine. A total of 409 subjects were enrolled and given 15 μg hemagglutinin antigen by s.c. injection. Antibody titers were measured using hemagglutination-inhibition antibody assays before vaccination and 28 days after. The co-primary immunogenicity end-points were the proportion of subjects with antibody titers of 1:40 or more, the proportion of subjects with either seroconversion or a significant increase in antibody titer, and the factor increase in geometric mean titer. We collected 389 pair samples. Antibody titers of 1:40 or more were observed in 148 of 389 subjects (38.0%, 95% CI: 33.2-42.9). The immunogenicity was also confirmed in other end-points, but was not sufficient and was lower than in previous reports. A total of 96 of adverse events was reported: 51 local events and 57 systemic events. There were 12 subjects with both local and systemic events. Nearly all events were mild to moderate except in four subjects. A single 15-μg dose of AH1pdm vaccine did not induce sufficient immunogenicity in HCW, with mild-to-moderate vaccine-associated adverse events. We need to consider further improvement of the AH1pdm vaccine program in HCW for the prevention of nosocomial infection, as well as for the benefit of HCW.     

The Activity of Hyaluronan Synthase 2 Is Regulated by Dimerization and Ubiquitination

Hyaluronan is a component of the extracellular matrix, which affects tissue homeostasis. In this study, we investigated the regulatory mechanisms of one of the hyaluronan-synthesizing enzymes, HAS2. Ectopic expression of Flag- and 6myc-HAS2 in COS-1 cells followed by immunoprecipitation and immunoblotting revealed homodimers; after co-transfection with Flag-HAS3, also heterodimers were seen. Furthermore, the expressed HAS2 was ubiquitinated. We identified one acceptor site for ubiquitin on lysine residue 190. Mutation of this residue led to inactivation of the enzymatic activity of HAS2. Interestingly, K190R-mutated HAS2 formed dimers with wt HAS2 and quenched the activity of wt HAS2, thus demonstrating a functional role of the dimeric configuration.     

Exploring amino acids responsible for the temperature profile of glycoside hydrolase family 45 endoglucanase EGL3 from Humicola grisea

EGL3 and RCE1 are glycoside hydrolase family 45 endoglucanases isolated from Humicola grisea and Rhizopus oryzae respectively. The amino acid sequences of the two endoglucanases are homologous; on the other hand, the optimum temperature of EGL3 is higher than that of RCE1. In this study, four chimeric endoglucanases, named ER1, ER2, ER3 and ER4, in which one of four sequential amino acid regions of the EGL3 catalytic domain (CAD) was replaced by the corresponding RCE1 amino acids, were constructed to explore the region responsible for the EGL3 temperature profile. Then their temperature profiles were compared with that of the recombinant EGL3. Replacement of the N-terminal region of EGL3 with that of RCE1 caused the EGL3 temperature profile to shift to a lower temperature. These results suggest that the N-terminal amino acids of the EGL3 are responsible for the EGL3 temperature profile.     

Amino acid regions of family 45 endoglucanases involved in cotton defibrillation and in resistance to anionic surfactants and oxidizing agents

In the detergent industry, fungal endoglucanases are used to release microfibrils from the surfaces of dyed cellulosic fabrics to enhance color brightness. Family 45 endoglucanase (glycoside hydrolase family 45, GH45) EGL3 from Humicola grisea is more resistant to anionic surfactants and oxidizing agents than family 45 endoglucanase RCE1 from Rhizopus oryzae, while in the present study, a catalytic domain of RCE1 had higher defibrillation activity on dyed cotton fabrics than did that of EGL3. To identify the amino acid regions involved in these properties, we compared the characteristics of RCE1, EGL3, and three chimeric endoglucanases, in which each of the three regions of the catalytic domain of EGL3 was replaced by the corresponding region of the catalytic domain of RCE1. Amino acids in the N-terminal region were involved in resistance to anionic surfactants and oxidizing agents. Furthermore, amino acids in the region adjacent to the N-terminal region were involved in releasing microfibrils and in binding to dyed cotton fabrics, indicating that the binding of the amino acids in this region might be important in the release of microfibrils from dyed cotton fabrics.     

The formation of g=2.49-species of cytochrome P450 in the rat liver by PCB126 oral administration: identification of heme axial ligands by EPR spectroscopy

Rat livers and microsomes were subjected to electron paramagnetic resonance (EPR) measurements at 77 K. The EPR spectra of the livers from the control group, carbon tetrachloride-, 3-methylcholanthrene-, and 3,3',4,4',5-pentachlorobiphenyl (PCB126)-treated rats exhibited an EPR spectrum at g=2.40, 2.24, and 1.93, which is characteristic of P450 in a resting state. The liver of the PCB126-treated rats showed an additional distinct EPR spectrum at g=2.49, 2.26, and 1.87 (g=2.49-species). The heme environmental structure of g=2.49-species was identified by crystal field analysis using three EPR g-values of the microsome treated with various chemicals. These results indicated that g=2.49-species is a hemeprotein with cysteine thiolate at the 5th coordination site, and a nitrogenous ligand at the 6th site.     

A comparative study on the anatomy and development of different shapes of domatia in Cinnamomum camphora (Lauraceae)

BACKGROUND AND AIMS: Domatia are small organs usually found in the axils of major veins on the underside of leaves and, although they have received wide attention from ecologists, few detailed reports exist on their anatomy or development. This study is focused on the domatia of Cinnamomum camphora (Lauraceae) and is the first comparative study on the anatomy and development of the different shapes of domatia within a single plant. METHODS: Four types of domatia in C. camphora leaves were observed on paraffin sections under a microscope. KEY RESULTS: The domatia consisted of six histological parts: the upper epidermis, the upper mesophyll tissue, spongy tissue, the lower mesophyll tissue, the tissue filling the rim opening, and the lower epidermis. They differed from the non-domatial lamina mainly in the cell structure of the upper and lower mesophyll tissue and the rim tissue. Differences in domatium shapes were mainly associated with differences in the structure of the upper mesophyll and in the number and size of the rim tissue cells. Differences in the development of domatium types were observed in terms of initiation timing, differentiation of the upper mesophyll cells and degree of rim tissue development. CONCLUSIONS: In domatia, active anticlinal division in the lower mesophyll cells, as compared with the upper mesophyll cells, was coordinated with dynamic growth of rim tissue cells and resulted in cavity formation. The anatomical or developmental differences among the four types of domatia were related to the positions of the domatia within a leaf. In terms of the ecological implications, the major anatomical difference between the domatia used by herbivorous and carnivorous mites was in the development of the rim tissue.     

Tactile stimulation-induced rapid elevation of the synaptophysin mRNA expression level in rat somatosensory cortex

Synaptophysin is an integral membrane protein abundant in the synaptic vesicle and is found in nerve terminals throughout the brain. It was recently suggested that synaptophysin is also involved in the modulation of activity-dependent synapse formation. In this study, we examined at the individual level whether tactile stimulation selectively influenced the synaptophysin mRNA expression level in the somatosensory cortex of rats. Anesthetized rats were caressed on the back by an experimenter's palms for 20 min and the mRNA expression levels in the somatosensory and the visual cortices 5 min afterwards were determined using quantitative PCR methodology. The synaptophysin mRNA expression level was selectively higher in the experimental group than in the control group in the somatosensory cortex but not in the visual cortex. This suggests that the mRNA expression level of synaptophysin induced by neuronal activity is related to the regulation of synapse formation or remodeling or both.     

Influence of simulated acid snow stress on leaf tissue of wintering herbaceous plants

Acid snow might be an environmental stress factor for wintering plants since acid precipitates are locally concentrated in snow and the period in which ice crystals are in contact with shoots might be longer than that of acid precipitates in rain. In this study, 'equilibrium' and 'prolonged' freezing tests with sulfuric acid, which simulate situations of temperature depression and chronic freezing at a subzero temperature with acid precipitate as acid snow stress, respectively, were carried out using leaf segments of cold-acclimated winter wheat. When leaf segments were frozen in the presence of sulfuric acid solution (pH 4.0, 3.0 or 2.0) by equilibrium freezing with ice seeding, the survival rate of leaf samples treated with sulfuric acid solution of pH 2.0 decreased markedly. Leaf samples after supercooling to -4 and -8 degrees C in the presence of sulfuric acid solution (pH 2.0) without ice seeding were less damaged. When leaf samples were subjected to prolonged freezing at -4 and -8 degrees C for 7 d with sulfuric acid (pH 2.0), the survival rates of leaf samples exposed to sulfuric acid decreased more than those of leaf samples treated with water. On the other hand, leaf samples were less damaged by prolonged supercooling at -4 and -8 degrees C for 7 d with sulfuric acid (pH 2.0). The results suggest that an acid condition (pH 2.0) in the process of extracellular freezing and/or thawing promotes freezing injury of wheat leaves.