h-BN nanosheets as simple and effective additives to largely enhance the activity of Au/TiO2 plasmonic photocatalysts.

The activity of Au nanoparticle-loaded P25 TiO2 (Au/P25) plasmonic photocatalysts, evaluated by the oxidative decomposition of formic acid in water under visible light irradiation, was enhanced up to 3 times by simply mixing Au/P25 with photocatalytically inactive h-BN nanosheets as a result of electron transfer from photoexcited Au/TiO2 to the h-BN nanosheets and retardation of the charge recombination.

The population demography of Betula maximowicziana, a cool-temperate tree species in Japan, in relation to the last glacial period: its admixture-like genetic structure is the result of simple population splitting not admixing.

Conservation of the local genetic variation and evolutionary integrity of economically and ecologically important trees is a key aspect of studies involving forest genetics, and a population demographic history of the target species provides valuable information for this purpose. Here, the genetic structure of 48 populations of Betula maximowicziana was assessed using 12 expressed sequence tag-simple sequence repeat (EST-SSR) markers. Genetic diversity was lower in northern populations than southern ones and structure analysis revealed three groups: northern and southern clusters and an admixed group. Eleven more genomic-SSR loci were added and the demographic history of these three groups was inferred by approximate Bayesian computation (ABC). The ABC revealed that a simple split scenario was much more likely than isolation with admixture, suggesting that the admixture-like structure detected in this species was due to ancestral polymorphisms. The ABC analysis suggested that the population growth and divergence of the three groups occurred 96 800 (95% CI, 20 500-599 000) and 28 300 (95% CI, 8700-98 400) years ago, respectively. We need to be aware of several sources of uncertainty in the inference such as assumptions about the generation time, overlapping of generations, confidence intervals of the estimated parameters and the assumed model in the ABC. However, the results of the ABC together with the model-based maps of reconstructed past species distribution and palaeoecological data suggested that the modern genetic structure of B. maximowicziana originated prior to the last glacial maximum (LGM) and that some populations survived in the northern range even during the LGM.

Cell dynamics in Hertwig's epithelial root sheath and surrounding mesenchyme in mice irradiated to the head.

OBJECTIVE: To investigate the mechanisms that cause damage to root formation as a result of irradiation to the mouse head, morphological changes in molar dental roots and cell dynamics in Hertwig's epithelial root sheath (HERS), and surrounding mesenchymal tissue were examined. MATERIALS AND METHODS: To perform the experiments, 5-day-old C57BL/6 mice were randomly divided into three groups: the control group (0 Gy) and irradiated groups (10 and 20 Gy). Micro-CT analysis, HE staining, immunohistochemistry analysis, and TUNEL assay were then performed. RESULTS: Roots in irradiated mice were dose-dependently shorter than those of control mice. Cells located outside the root dentin, with abnormal morphology in irradiated mice, were positive for an odontoblast marker. HERS fragmentation occurred earlier in irradiated mice than in control mice, and HERS was trapped by the calcified apical tissue. A dose-dependent reduction in the number of proliferating cells within the apical dental pulp and periapical periodontal ligament surrounding HERS was observed in irradiated mice. Apoptotic cells in the dental pulp and periodontal ligament surrounding HERS were hardly seen. CONCLUSIONS: These results indicate that the early disappearance of HERS and the proliferative suppression of the surrounding mesenchymal cells, which was induced by irradiation, caused dental root malformation.

Extraordinary effects of an argon atmosphere on TiO2 photocatalysis.

When used as a photocatalyst under solar light, TiO2 tends to show a low photocatalytic activity. We report here that even TiO2 exhibits a high photocatalytic activity toward the decomposition (mineralization) of aqueous organic contaminants under simulated solar light when used under an Ar atmosphere (Ar flow). The photocatalytic decomposition rate of a cationic dye, crystal violet, and the CO2 evolution rate over TiO2 (P25, mainly composed of anatase and rutile) under Ar flow were substantially higher than those obtained in air and under air, O2, N2 and CO2 flows. Similar positive effects of Ar flow on photocatalytic reactions were observed when another cationic dye, basic violet 4, and TiO2 (anatase) were used, suggesting the versatility of Ar flow for improving photocatalytic activities.

Identification of a distinct lineage of Cacopsylla chinensis (Hemiptera: Psyllidae) in Japan on the basis of two mitochondrial DNA sequences.

Psyllids are a menacing pests of pears (Pyrus spp.) grown in temperate and subtropical regions of the world, including Taiwan and China. Pear psyllids belong to the large genus Cacopsylla (Psyllidae: Psyllinae). Among the 28 psyllid species that infest pear trees, Cacopsylla chinensis (Yang and Li, 1981) is considered the most harmful. Two psyllid outbreaks involving exotic species affected Japanese pear (Pyrus pyrifolia variety culta) orchards in the Saga Prefecture in July and November 2011. The psyllids were morphologically identical to the summer and winter forms of C. chinensis. In this study, we performed DNA sequence analysis of the mitochondrial cytochrome oxidase I-leucine tRNA-cytochrome oxidase II (COI-tRNA(Leu)-COII) and 16S rDNA regions to elucidate the phylogenetic relationships among 82 summer-form psyllids, five winter-form psyllids from several orchards in Japan, and those reported from Taiwan and China. The sequences of the COI-tRNA(LEU)-COII and 16S rDNA regions were identical among all 87 psyllids from Japan, regardless of summer/winter forms or orchards in Saga, Japan. Comparison of nucleotide sequences and phylogenetic analysis differentiated Japanese psyllids from the Taiwanese and Chinese C. chinensis isolates, with approximately 8 and 7% nucleotide difference in the COI-tRNA(LEU)-COII and 16S rDNA regions, respectively. The results suggest that C. chinensis possess a high level of genetic variability and that the psyllids responsible for the outbreak in Saga, Japan belong to a distinct lineage of C. chinensis.

Volume measurement of crowns in mandibular primary central incisors by micro-computed tomography.

OBJECTIVE: To determine sex differences in the tissue proportions of crowns of mandibular primary central incisors in Chinese children and to quantify the volume of crown components in three dimensions using micro-computed tomography (micro-CT). MATERIALS AND METHODS: The specimens used in this study were 41 mandibular first deciduous incisor teeth with intact crowns (21 males and 20 females) obtained from patients between 5-6 years of age. Each specimen was scanned using micro-CT at a resolution of 0.05 mm and 3D-rendered images were created. The volume of each component of the crown was measured and examined for differences in different sex and ages. RESULTS: The pulp chamber volume decreased with age and the volume ratio of the pulp chamber to the whole crown was significantly smaller in 6-year-olds than in 5-year-olds (p < 0.05). CONCLUSIONS: Males had significantly larger tooth crown volumes and dentin volumes than females did (p < 0.001), while the volume of enamel showed no sexual dimorphism.

[Intraoperative direct angiography for the diminutive central pulmonary artery in a patient with major aortopulmonary collateral arteries].

It can be difficult to judge the degree of arborization of diminutive central pulmonary arteries (cPA) in patients with major aortopulmonary collateral arteries (MAPCA). Even through preoperative cardiac catheterization may not give adequate information. We introduce intra-operative direct angiography of diminutive cPA for patients with MAPCA. This would be one of the good options to judge the degree of arborization of the diminutive cPA, and to decide an initial surgical treatment. In this case, unifocalization of MAPCA without patch augmentation of pulmonary arteries, and an aortopulmonary shunt were performed at the 1st procedure. As enough growth of the cPA was obtained, this patient did not require additional patch augmentation of the pulmonary artery at the time of complete repair.

Utility of the Eating Assessment Tool-10 (EAT-10) in Evaluating Self-Reported Dysphagia Associated with Oral Frailty in Japanese Community-Dwelling Older People.

OBJECTIVES: The aim of the present study was to verify the associations between dysphagia as screened by the Eating Assessment Tool-10 (EAT-10) and indicators in the 100-mL water swallowing test (WST) or medical history among community-dwelling older people. STUDY DESIGN: A cross-sectional study. SETTING AND PARTICIPANTS: The study participants were 202 community-dwelling older Japanese adults aged ≥65 years. MEASUREMENTS: We investigated the participants' basic attributes, including age, sex, body mass index, medical history (cerebrovascular disease, respiratory disease: chronic obstructive pulmonary disease [COPD], and history of pneumonia within the previous year), and number of prescribed medications. Dysphagia assessment was performed using the EAT-10 and the 100-mL WST as subjective and objective examinations, respectively. The 100-mL WST used four indicators (SC: swallowing capacity, VS: volume per swallow, TS: time per swallow, and choking signs). Patients with and without dysphagia according to the EAT-10 were divided into two groups according to a cutoff score of 3, and the two groups were then compared in terms of their characteristics including medical history and 100-mL WST indicators. A multiple logistic regression model was used to determine whether the indicators of the 100-mL WST or medical history were independently associated with dysphagia in the EAT-10. RESULTS: The multiple logistic regression analysis revealed that dysphagia in the EAT-10 was independently associated with male sex (odds ratio [OR] = 2.78; 95% confidence interval [CI] = 0.98-7.90), COPD (OR = 14.68; 95% CI = 3.14-68.85), and VS and TS in the 100-mL WST (OR = 0.85; 95% CI = 0.80-0.90 and OR = 3.03; 95% CI = 1.78-5.16, respectively). CONCLUSIONS: Our results revealed that the EAT-10 was independently associated with the 100-mL WST and respiratory disease. We propose that swallowing rehabilitation incorporating respiratory training could be effective for older people screened using the EAT-10.

Sensory system-predominant distribution of leukotriene A4 hydrolase and its colocalization with calretinin in the mouse nervous system.

Leukotriene B4 is a potent lipid mediator, which has been identified as a potent proinflammatory and immunomodulatory compound. Although there has been robust evidence indicating that leukotriene B4 is synthesized in the normal brain, detailed distribution and its functions in the nervous system have been unclear. To obtain insight into the possible neural function of leukotriene B4, we examined the immunohistochemical distribution of leukotriene A4 hydrolase, an enzyme catalyzing the final and committed step in leukotriene B4 biosynthesis, in the mouse nervous system. Immunoreactivity for leukotriene A4 hydrolase showed widespread distribution with preference to the sensory-associated structures; i.e. neurons in the olfactory epithelium and vomeronasal organ, olfactory glomeruli, possibly amacrine cells, neurons in the ganglion cell layer and three bands in the inner plexiform layer of the retina, axons in the optic nerve and tract up to the superior colliculus, inner and outer hair cells and the spiral ganglion cells in the cochlea, vestibulocochlear nerve bundle, spinal trigeminal tract, and lamina II of the spinal cord. Double immunofluorescence staining demonstrated that most of the leukotriene A4-hydrolase-immunopositive neurons coexpressed calretinin, a calcium-binding protein in neurons. The ubiquitous distribution of leukotriene A4 hydrolase was in sharp contrast with the distribution of leukotriene C4 synthase [Shimada A, Satoh M, Chiba Y, Saitoh Y, Kawamura N, Keino H, Hosokawa M, Shimizu T (2005) Highly selective localization of leukotriene C4 synthase in hypothalamic and extrahypothalamic vasopressin systems of mouse brain. Neuroscience 131:683-689] which was confined to the hypothalamic and extrahypothalamic vasopressinergic neurons. These results suggest that leukotriene B4 may exert some neuromodulatory function mainly in the sensory nervous system, in concert with calretinin.

Three-dimensional analysis of pulp chambers in maxillary second deciduous molars.

OBJECTIVE: The purpose of this study was to clarify the positional relationship between the crown contour and the pulp chamber using micro-CT system for restorations of maxillary second deciduous molar. METHODS: Five maxillary second deciduous molar teeth each from the deciduous dentition and the mixed dentition periods were used. The positional relationship between the crown contour and pulp chamber was three-dimensionally observed by micro-CT. In addition, the thickness of the dentin at each of the pulp horns and the volume ratio of the pulp chamber against the whole crown were measured. RESULTS: In relationship to the crown contour and the pulp chamber, the pulp horn of the mesiobuccal cusp showed greatest protrusion and eminent swelling of its mesial wall in both the deciduous dentition and the mixed dentition periods. Furthermore, the pulp chamber was shifted to the mesial side. The volume ratio of the pulp chamber to the whole crown, the ratio in the mixed dentition period showed to be significantly smaller than in the deciduous dentition period. The dentin thickness at the mesiobuccal pulp horn was the thinest. CONCLUSIONS: These results suggest that in preparation of cavities in maxillary second deciduous molars, care is necessary not to expose of the mesiobuccal pulp horn. Especially, the mesial wall of the mesiobuccal pulp horn should be noted.

Expression of CD44 in normal human versus tumor endometrial tissues: possible implication of reduced expression of CD44 in lymph-vascular space involvement of cancer cells.

Alternatively spliced variants of the CD44 molecule have been found to be associated with invasive and metastatic potential of cancer cells and poor prognosis in several types of carcinoma. We have examined expression of CD44 in normal and cancerous tissues of the endometrium as well as in cell lines established from patients with endometrial cancers by the combination of reverse transcription-polymerase chain reaction and Southern blot hybridization and by cell surface staining with antibodies to CD44. Of eight cancer cell lines tested, two lines, HOOUA and HEC50B, both of which are possibly potential candidates for metastasis, expressed a very small amount of mRNA for CD44. Variant forms of CD44 were expressed in 9 of 11 (81.8%) normal endometria, whereas 8 of 47 (17.0%) endometrial carcinomas showed expression of the variants. Hyperplasia samples displayed the variant expression in 42.9% of specimens (the value was between those of the normal and cancerous cells) and none of 3 in Müllerian mixed tumors. There was a significant difference in frequencies of CD44 variant expression between normal and cancerous tissues. Furthermore, lymph-vascular space involvement of cancer cells was observed to be statistically significant in the CD44-negative group as opposed to the positive group. Reverse transcription-polymerase chain reaction and Southern blot hybridization clearly demonstrated that normal endometrial tissues express the standard CD44 form as well as the variant form. Immunohistochemical examination of normal endometrium revealed that intense staining was seen on the gland cells at the basement membrane side, and less intense staining was seen between the gland cells. These results suggest that CD44 could play important roles in the function of normal endometrium and that reduced CD44 expression might be related to the metastasis of endometrial cancer cells through lymph-vascular space.

Changes in the properties of mouse tongue muscle fibres before and after weaning.

The purpose of this study was to clarify any changes in muscle fibre properties in different regions of murine tongue during development, and to assess the effects of functional changes including weaning on these muscle fibres. The tongue was divided into upper and lower regions at the lateral margin, and the expression of myosin heavy chain (MHC) isoforms at different ages was investigated. Expression of genes encoding MHC proteins was quantified at the transcription level by quantitative reverse transcriptase polymerase chain reaction, and the protein expression of MHC isoforms was assessed by immunostaining. No difference was found in isoform expression between the upper and lower regions of the tongue before weaning. However, the expression of MHC-2b increased markedly in both regions after weaning, while that of MHC-2a decreased. At the age of 16 weeks, the expression of MHC-2b in the lower region was greater than that in the upper region. These findings show that during weaning, when there is a shift from sucking behaviour to mastication, the expression of MHC-2b increases along with an increase in the speed and strength of muscle contraction. Also, contraction force becomes stronger in the lower region of the tongue than the upper region at the age of 16 weeks.

Superficial and deep layer muscle fibre properties of the mouse masseter before and after weaning.

To clarify changes in the properties of the masseter muscle superficial and deep layer muscle fibres, which initiate masticatory movement, myosin heavy chain isoforms were evaluated based on immunohistochemistry at the transcription level in male mice both before and after weaning. In the results, MHC-2b isoforms, the isoforms with the fastest contraction speed, were observed in the superficial layer after weaning. However, MHC-2a isoforms with slower contraction speeds were not apparent. By contrast, in the deep layer, MHC-2a isoforms were present, as were MHC-2b isoforms, however, there were fewer MHC-2b isoforms present than in the superficial layer. The most rapid movement in the mouse mandible was observed anteroposteriorly during mastication. As the superficial layer of the masseter muscle runs parallel to the direction of mandibular movement, the presence of MHC-2b isoforms in it is consistent. The presence of MHC-2a isoforms in the deep layer, lying at right angles to the direction of mastication movement, is consistent with the positional adjustment of the mandible contributed by the deep layer muscle fibres during masticatory movement. We therefore conclude that complicated masticatory movement is achieved by the presence of various muscle bundles within the masseter, each carrying out different roles.

Heterogeneity in soil water and light environments and dispersal limitation: what facilitates tree species coexistence in a temperate forest?

In the present study, we analysed the habitat association of tree species in an old-growth temperate forest across all life stages to test theories on the coexistence of tree species in forest communities. An inventory for trees was implemented at a 6-ha plot in Ogawa Forest Reserve for adults, juveniles, saplings and seedlings. Volumetric soil water content (SMC) and light levels were measured in 10-m grids. Relationships between the actual number of stems and environmental variables were determined for 35 major tree species, and the spatial correlations within and among species were analysed. The light level had no statistically significant effect on distribution of saplings and seedlings of any species. In contrast, most species had specific optimal values along the SMC gradient. The optimal values were almost identical in earlier life stages, but were more variable in later life stages among species. However, no effective niche partitioning among the species was apparent even at the adult stage. Furthermore, results of spatial analyses suggest that dispersal limitation was not sufficient to mitigate competition between species. This might result from well-scattered seed distribution via wind and bird dispersal, as well as conspecific density-dependent mortality of seeds and seedlings. Thus, both niche partitioning and dispersal limitation appeared less important for facilitating coexistence of species within this forest than expected in tropical forests. The tree species assembly in this temperate forest might be controlled through a neutral process at the spatial scale tested in this study.

Hepatitis C virus NS5A protein is phosphorylated in vitro by a stably bound protein kinase from HeLa cells and by cAMP-dependent protein kinase A-alpha catalytic subunit.

Hepatitis C virus (HCV) has a positive-strand RNA genome that codes for a polyprotein precursor, which is processed co- and post-translationally by cellular and viral proteinases into three structural and at least six non-structural (NS) proteins. The NS5A protein, expressed in mammalian cells, exists in two phosphorylated forms of 56-kDa and 58-kDa. In this study, we provide evidence for a stable association between NS5A and a protein kinase from HeLa cells and hepatocellular carcinoma (HepG2) cells by co-immunoprecipitation and by affinity to immobilized glutathione-S-transferase (GST)-NS5A fusion protein produced in E. coli. This protein kinase could phosphorylate in vitro the native NS5A on serine residues, (GST)-NS5A, histone H1, and casein as substrates. In addition, the GST-NS5A was also phosphorylated in vitro by the cAMP-dependent protein kinase A-alpha catalytic subunit.

Characterization of the nuclear localization signal and subcellular distribution of hepatitis C virus nonstructural protein NS5A.

Hepatitis C virus (HCV) has a positive strand RNA genome that codes for a polyprotein that is processed co-translationally and post-translationally into three structural and at least seven nonstructural (NS) proteins. To investigate the function of NS5A, a recombinant vaccinia virus was constructed in which the NS5A gene was cloned under the control of T7 promoter and encephalomyocarditis virus 5'-untranslated region (EMCV-UTR) for cap-independent translation in mammalian cells. In addition, the NS5A gene was also cloned under the control of cytomegalovirus (CMV) early promoter. The NS5A expressed in monkey kidney (CV-1) cells was located predominantly in the cytoplasm. Using immunohistochemical analysis, the subcellular distribution of NS5A in liver biopsy samples from chronic HCV-infected patients was also found to be in the cytoplasm. However, the NS5A protein has a stretch of positively charged domain in the vicinity of proline and valine residues, (PPRKKRTVV), characteristic of a nuclear localization signal (NLS), in the COOH-terminal half of the protein. To investigate whether the putative NLS of NS5A is functional, chimeric expression plasmids were constructed in which regions containing the NLS were fused to the N-terminus of the E. coli beta-galactosidase (E. coli beta-Gal). The expression of the fusion proteins in CV-1 cells resulted in their nuclear localization, indicating that the putative NLS is functional in targeting the heterologous protein, E. coli beta-Gal, to the nucleus, although the native NS5A is retained in the cytoplasm.

Effects of prostaglandin E1 in experimental autoimmune myasthenia gravis.

The effects of prostaglandin E1 (PGE1), a potent inhibitor of lymphocyte functions, were studied in rats immunized with acetylcholine receptor (AChR) to induce experimental autoimmune myasthenia gravis (EAMG). Daily injections of PGE1, 400 micrograms per day, prevented the development of acute EAMG, which is attributed to antibody-dependent, complement-mediated cytolysis. This was associated with suppression of delayed-type cutaneous hypersensitivity response to AChR. PGE1 did not prevent the subsequent onset of chronic EAMG, which reflects accelerated degradation of AChR by antibody and complement-mediated cell lysis in the postsynaptic membrane.

Neuromuscular defect after suppression of ion conductance.

In rat skeletal muscle, trimetazidine (TMZ) caused a transmission defect without directly blocking binding of acetylcholine--ionophore impairment. In vivo, TMZ produced low-amplitude and cumulative depression of successive muscle responses, and immediate posttetanic exhaustion. These features differed from the effects of alpha-bungarotoxin (alpha-BuTx) or immunization with acetylcholine receptor (experimental autoimmune myasthenia gravis [EAMG]). In vitro, TMZ-induced block was similar to both alpha-BuTx-induced block and EAMG in many respects, but there were differences in endplate potentials evoked during and after rapid repetitive activations. These differences suggest that antibodies to the acetylcholine receptor do not affect the ionophore.

Effects of epinephrine, ouabain, and insulin in experimental autoimmune myasthenia gravis.

To gain a clue to the target of anti-AChR antibody, rats with acute and chronic experimental autoimmune myasthenia gravis (EAMG) that was induced by immunization with Narke anti-acetylcholine receptor (AChR) were studied using agents acting on active Na-k transport. Postsynaptic response to epinephrine was defective in chronic EAMG with high titers of antibody, suggesting that active Na-K transport system modulated by cyclic adenosine monophosphate (AMP) may be affected primarily by antibody. Sensitivity to ouabain was less than normal in acute EAMG and became close to normal when treated with anticomplementary factor. Findings suggest that acute EAMG is a case of functional denervation. Normal response to insulin occurred in all phases of EAMG.

Ultrastructural localization of acetylcholine receptor at the motor endplate: myasthenia gravis and other neuromuscular diseases.

Peroxidase-conjugated alpha-bungarotoxin (P-BGT) was used for the ultrastructural localization of the acetylcholine receptor in motor endplates. Brachial biceps muscle specimens were obtained from six patients with myasthenia gravis (MG) (two ocular and four generalized), five other patients with neuromuscular diseases (limb-girdle dystrophy, polymyositis, and amyotrophic lateral sclerosis) and two controls. In all patients with generalized MG, most of the endplates showed a marked decrease in P-BGT binding. In one of two patients with ocular MG, the amount and distribution of P-BGT binding appeared normal, whereas the other patient showed a slight decrease in P-BGT binding. There was a loose correlation between clinical severity of MG and acetylcholine receptor index or antiacetylcholine receptor antibodies. On the other hand, the amount and distribution of acetylcholine receptor in other neuromuscular diseases was well preserved, even at the endplates denuded of their nerve terminals in amyotrophic lateral sclerosis (ALS) cases.