Thermoelectric power calculation by the Boltzmann equation: Na(x)CoO(2)

A full-potential augmented-plane-wave (FLAPW) band-structure calculation in the local density approximation (LDA) was carried out for hexagonal Na(x)CoO(2) (x = 0.45, 0.55, 0.66 and 0.75). The Seebeck tensor was estimated by the Boltzmann theory, assuming that the relaxation time is constant on the Fermi surface. The Seebeck tensor is extremely anisotropic; the c-axis Seebeck coefficient varies dramatically with the Na content. The calculation reproduces the experiment semiquantitatively.

Residue level of polycyclic aromatic hydrocarbons in Japanese paddy soils from 1959 to 2002

The residue level of 21 polycyclic aromatic hydrocarbons (PAHs) and the temporal changes in this level were investigated in paddy soils collected from particular experimental sites in Japan from 1959 to 2002. The average total PAH concentration in all the samples was 496 microg kg(-1), and it ranged from 52.9 to 2180 microg kg(-1). The residue level of the PAHs was the highest during the 1960s, rapidly decreased during the 1970s, and remained almost constant thereafter. Relatively high PAH concentrations were observed in soils from areas that experienced heavy snowfall and that had relatively low air temperature. The predominant PAHs were phenanthrene, fluoranthene, naphthalene, and pyrene, and their concentration overall and in relation to that of the total PAHs decreased each year since the 1960s. Similarities in the PAH profiles among the locations were determined using the concentration correlation matrix and cluster analysis, and ratios of the levels of specific PAH pairs were also calculated to determine their origin. The collected data suggested that the origins of soil PAHs changed chronologically from the burning of agricultural wastes such as stubble before the mid-1970s to the combustion of fossil fuel and its secondary products after the mid-1970s.

The r40-kDa outer membrane protein human monoclonal antibody protects against Porphyromonas gingivalis-induced bone loss in rats

BACKGROUND

Porphyromonas gingivalis has been implicated as an important pathogen in the development of adult periodontitis, and its colonization of subgingival sites is critical in the pathogenic process. We recently reported the construction and characterization of human immunoglobulin G isotype clones, which were specifically reactive with recombinant (r) 40-kDa outer membrane protein (OMP) of P. gingivalis. The aim of this study was to investigate the efficacy of human monoclonal antibody (hMAb) against r40-kDa OMP of P. gingivalis to the protection alveolar bone loss by P. gingivalis in rats.

METHODS

The role of 40-kDa OMP in the adherence of P. gingivalis to human gingival epithelial cells (HGECs) was examined by preincubating with r40-kDa OMP hMAb before adding the HGECs. Moreover, we used a rat model to examine the effect of the anti-r40-kDa OMP hMAb in alveolar bone loss by oral infection. Forty-six days after the last infection, the periodontal bone level was assessed morphometrically on defleshed rat jaws.

RESULTS

The adherence to HGECs was reduced by 84% compared to adherence levels without the antibody. P. gingivalis could not be detected from rats in a P. gingivalis-non-infected group and a group that was administered the anti-r40-kDa OMP hMAb. The bone loss in P. gingivalis-infected animals that were administered the anti-r40-kDa OMP hMAb was significantly lower than that of P. gingivalis-infected rats.

CONCLUSIONS

Our results suggest that transchromosomic mouse-derived hMAb against r40-kDa OMP of P. gingivalis protects against periodontal bone loss. This newly constructed anti-r40-kDa OMP hMAb was used to protect against periodontal diseases caused by P. gingivalis infection.

Expression of Bone Extracellular Matrix Proteins on Osteoblast Cells in the Presence of Mineral Trioxide

The biocompatibility of periapical tissue with mineral trioxide aggregate (MTA) affects its ability to repair and regenerate itself. Here we report the cytotoxicity of MTA and how it affects the expression of bone extracellular matrix protein in MC3T3-E1 osteoblast cells. We quantified the cytotoxicity of MTA, amalgam, and Dycal (Dentsply/Caulk, Milford, DE) on MC3T3-E1 cells by measuring the ability of cells to cleave a tetrazolium salt to produce formazan dye during a period of 24, 48, or 96 hours. We used reverse-transcriptase polymerase chain reaction with primer sets for type I collagen, osteocalcin, and bone sialoprotein to measure the gene-expression response of MC3T3-E1 cells treated with MTA. MTA, amalgam, and Dycal were less toxic after 48 hours. MC3T3-E1 cell growth with MTA and Dycal was greater than nonstimulated controls. MTA caused an upregulation of type I collagen and osteocalcin messenger RNA expression after 24 hours. These results showed that, in the presence of MTA, cells grow faster and produce more mineralized matrix gene expression in osteoblasts.

Restraint stress enhances alveolar bone loss in an experimental rat model

BACKGROUND AND OBJECTIVE

The purpose of the present study was to examine the effects of restraint stress on periodontal breakdown resulting from Porphyromonas gingivalis-challenged periodontitis in rats.

MATERIAL AND METHODS

To examine the influence of restraint stress on periodontal breakdown, rats were orally challenged with the periodontal pathogen P. gingivalis. Twenty male, specific pathogen-free (SPF) 3-wk-old, Sprague-Dawley rats were divided into four groups: group A (controls), group B (exposed to restraint stress for 12 h/d for 22 d), group C (orally challenged with P. gingivalis), and group D (exposed to restraint stress for 12 h/d for 22 d and orally challenged with P. gingivalis). After 22 d, all animals were killed. The distance from the alveolar bone crest to the cemento-enamel junction was determined, concentrations of adrenocorticotropic hormone were measured as stress markers, and atrophy of the thymus and spleen were assessed. In addition, the furcation area of the maxillary molars was examined histologically, while gingival cytokine gene expression was assessed by mRNA using reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

In the restrained group, all stress markers were elevated, and the thymus and spleen were atrophied. Combined restraint stress and oral challenge with P. gingivalis resulted in significantly higher bone loss, and osteoclasts were observed. RT-PCR analysis revealed low cytokine gene expression in the restrained groups.

CONCLUSION

These results suggest that the presence of restraint stress significantly enhances the progression of P. gingivalis-challenged periodontitis in rats.

Antifungal Effect of Acrylic Resin Containing Apatite-coated TiO2 Photocatalyst

The purpose of this study was to develop an acrylic resin with antifungal properties by leveraging the photocatalytic activity of apatite-coated titanium dioxide (Ap-TiO2). Candida albicans was used for antifungal activity assay of the specimen plates under ultraviolet A (UVA) with a black light source. Statistically significant decreases in cell viability in acrylic resins containing 5 wt% and 10 wt% Ap-TiO2 were observed after irradiation for two, four, and six hours (P<0.01), when compared to the control. As for the flexural strength and modulus values of acrylic resins mixed with Ap-TiO2 and TiO2 particles, they varied before and after irradiation. Among the tested specimens, a 5 wt% content of Ap-TiO2 in acrylic resin exceeded the requirements of ISO 1567. It was thus suggested that acrylic resin containing 5 wt% Ap-TiO2 could exert antifungal effects on C. albicans, while at the same time maintain adequate mechanical properties for clinical use.

Apoptosis signaling pathways in lung diseases

Evidence that apoptosis plays an important role in the pathophysiology of lung diseases has been accumulated. Apoptosis signaling is classically composed of two principle pathways. One is a direct pathway from death receptor ligation to caspase cascade activation and cell death. Death receptor ligation triggers recruitment of the precursor form of caspase-8 to a death-inducing complex, through the adaptor protein FADD, which leads to caspase-8 activation. The other pathway triggered by stimuli such as drugs, radiation, infectious agents and reactive oxygen species is initiated in mitochondria. After cytochrome c is released into the cytosol from the mitochondria, it binds to Apaf1 and ATP, which then activate caspase-9. Recently, endoplasmic reticulum has also been shown to be the organelle to execute apoptosis. Further understanding of molecular mechanisms of apoptosis and its regulation by novel drugs may lead to the development of effective strategies against lung diseases. We overview the signaling pathways of apoptosis and discuss the involvement of apoptosis in the pathophysiology of various lung diseases.

Effects of an oil spill and discharge of domestic sewage on the insect fauna of Cururu stream, Manaus, AM, Brazil

Assemblages of aquatic and edaphic insects in three streams in Central Amazonia were used to evaluate the impact on one of the streams (Cururu) caused by an oil spill that occurred in August 1999. The Cururu stream had already been impacted by domestic sewage. These three streams were evaluated during four different periods of the regional hydrological cycle (falling-, low-, rising- and high-water), from September 2000 to May 2001. An Eckman dredge, an aquatic entomological net and a manual auger were used to collect insects, which were used to estimate the taxonomic richness (at the family level) and insect density in each stream. Anoxic and eutrophic conditions were determined in each stream based on the mean concentration of dissolved oxygen, total nitrogen and phosphorus. Richness and abundance of insect fauna were higher in the Cristalino stream (not impacted) than in the Bom Jardim stream (impacted by domestic sewage) and in the Cururu stream, with the exception of samples collected along the stream banks (littoral fauna). The mean dissolved oxygen was lower in the Cururu stream than in the other two, while the mean concentrations of total nitrogen and phosphorus were higher. These elements showed intermediate values in the Bom Jardim stream, while the opposite pattern was observed in the Cristalino stream, with higher concentrations of dissolved oxygen and lower concentrations of total nitrogen and phosphorus. The concentrations of these variables reflect the modifications resulting from anthropogenic eutrophication caused by the discharge of domestic sewage into Bom Jardim and Cururu and by the oil spill in Cururu, which negatively affected the richness and abundance of insects in these streams.

Role of cellulose-binding domain of exocellulase I from white rot basidiomycete Irpex lacteus

The core fragment (designated P-42), devoid of the cellulose-binding domain (CBD) in the C-terminus and prepared from Irpex lacteus exocellulase I (Ex-1), was isolated by limited proteolysis using papain. Both the hydrolytic activity and binding ability of the isolated P-42 toward insoluble cellulose were lower than those of the native Ex-1, whereas Ex-1 and P-42 showed similar hydrolytic activities toward soluble substrates. These results indicate that the CBD of I. lacteus Ex-1 is the important domain which could enhance hydrolytic activity and binding ability of the enzyme toward insoluble cellulose. In addition, the isolated P-42 was different from the native Ex-1 in terms of enzymatic properties such as pH and temperature stabilities. These differences in stability, with regard to pH and temperature, between P-42 and the native Ex-1 are probably due to the O-linked sugar chains existing in the linker region.

The p53-Mdm2 association in epithelial cells in idiopathic pulmonary fibrosis and non-specific interstitial pneumonia

BACKGROUND

Wild-type p53 is increased during cellular responses to various stresses. Mdm2, which is induced by p53, regulates p53 protein concentrations through the ubiquitin-proteasome pathway.

AIM

To investigate whether the Mdm2 mediated ubiquitination of p53 is associated with epithelial cell apoptosis in idiopathic pulmonary fibrosis (IPF).

METHODS

Immunohistochemistry and western blot analysis were carried out on lung samples obtained by lung biopsy from patients with IPF and non-specific interstitial pneumonia (NSIP).

RESULTS

The expression of p53, phosphorylated p53, Mdm2, p21, and Bax was upregulated in epithelial cells from patients with IPF and NSIP compared with normal lung parenchyma. Except for p21, there was a significant increase in the expression of these factors in IPF compared with NSIP. In addition, the number of apoptotic cells and the number of p53 and Bax positive cells was increased compared with controls. p53 conjugated with Mdm2 was decreased in IPF compared with NSIP and controls. Ubiquitinated p53 was increased in both IPF and NSIP compared with controls.

CONCLUSIONS

Signalling molecules associated with p53 mediated apoptosis may participate in epithelial cell apoptosis, and the attenuation of p53-Mdm2 conjugation and of p53 degradation may be involved in the epithelial cell apoptosis seen in IPF. Augmented epithelial apoptosis in IPF may lead to the poor prognosis compared with NSIP.

Variations of Porphyromonas gingivalis fimbriae in relation to microbial pathogenesis

OBJECTIVES

Periodontal disease is an infectious disorder caused by a small subset of periodontal pathogens including Porphyromonas gingivalis. Accumulated evidences show that the expression of P. gingivalis heterogenic virulence properties is dependent on its clonal diversity. P. gingivalis expresses two distinct fimbria molecules, major and minor fimbriae, on its cell surfaces, both of which seem to be involved in the development of periodontitis. In this short review, variations of fimbriae in relation to microbial pathogenesis are discussed.

MATERIALS AND METHODS

Our recent findings are summarized to elucidate the relationship between clonal variation of fimbriae and bacterial pathogenicity of various strains.

RESULTS

Major fimbriae were classified into six types (I to V and Ib) based on the diversity of fimA genes encoding FimA (a subunit of major fimbriae). A majority of periodontitis patients were found to carry type II fimA organisms, followed by type IV, and type II fimA organisms were significantly occurred with more severe forms of periodontitis. Studies of clones with type II fimA have revealed significantly greater adhesive and invasive capabilities to epithelial cells than other fimA type clones. Minor fimbriae induced interleukin-1alpha (IL-1alpha), IL-1beta, IL-6, and tumor necrosis factor-alpha (TNF-alpha) cytokine expression in macrophages and were suggested to be a causative factor of alveolar bone resorption in animal models. The clonal diversity of minor fimbriae is unclear, however, distinct minor fimbria molecules were found in different strains.

CONCLUSION

The fimbria variations may have an influence on the development of periodontal disease.

Retinoic acid fails to reverse emphysema in adult mouse models

BACKGROUND

Previous work has shown that all-trans-retinoic acid reverses elastase induced emphysema in rats. Since there is currently no effective treatment for pulmonary emphysema, the effect of retinoic acid should be further investigated in other adult species. A study was undertaken using two murine models of emphysema to evaluate the effect of retinoic acid.

METHODS

The models used were an elastase induced emphysema model for acute alveolar destruction and a tumour necrosis factor (TNF)-alpha transgenic mouse which exhibits chronic air space enlargement, loss of elastic recoil, increased lung volume, and pulmonary hypertension comparable to human pulmonary emphysema. All-trans-retinoic acid (2 mg/kg) was injected for 12 successive days after the establishment of emphysema. The effects of treatment were evaluated using physiological and morphometric analyses.

RESULTS

In contrast to the rat, administration of all-trans-retinoic acid in these murine models did not improve the emphysema. Moreover, worsening of emphysema was observed in TNF-alpha transgenic mice treated with all-trans-retinoic acid. The level of keratinocyte chemoattractant (KC), a CXC chemokine, in bronchoalveolar lavage fluid was increased in TNF-alpha transgenic mice following retinoic acid treatment. These data raise the possibility that retinoic acid causes deterioration of emphysema by promoting inflammation in this model.

CONCLUSIONS

In these models, retinoic acid did not show positive effects on emphysema. The effect of retinoic acid in the treatment of pulmonary emphysema remains controversial, and further studies are required to determine its physiological effects under a variety of experimental conditions.

Porphyromonas gingivalis 67-kDa fimbriae induced cytokine production and osteoclast differentiation utilizing TLR2

Porphyromonas gingivalis, a major etiological agent of adult periodontitis, has two distinctly different types of fimbriae on the cell surface. The major fimbriae, which consist of a 41-kDa fimbrillin of P. gingivalis ATCC 33277, have been known to induce inflammatory cytokine production in murine peritoneal macrophages. In this study, we examined the effects of the minor fimbriae of P. gingivalis, composed of a 67-kDa fimbrillin, on cytokine production in murine peritoneal macrophages and the ability to induce osteoclast differentiation. Murine peritoneal macrophages were stimulated with P. gingivalis 67-kDa minor fimbriae for 24 h, then the levels of interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha and IL-6 production were determined by enzyme-linked immunosorbent assay (ELISA). To estimate osteoclast differentiation, mouse osteoclast precursors were placed on dentine slices, and cultured with or without P. gingivalis 67-kDa minor fimbriae for 7 days. P. gingivalis 67-kDa minor fimbriae clearly induced IL-1beta, TNF-alpha and IL-6 production in mouse macrophages. Furthermore, pit formations on the dentine slices were significantly extended when the osteoclast precursors were incubated with P. gingivalis 67-kDa minor fimbriae. Pretreatment with anti-Toll-like receptor 2 (TLR2) antibody significantly inhibited IL-1beta, TNF-alpha and IL-6 induction (P<0.05) in mouse macrophages and pit-forming activity of osteoclast precursor cells stimulated with P. gingivalis 67-kDa minor fimbriae. These results suggest that P. gingivalis 67-kDa minor fimbriae may provoke host inflammatory response and be involved in periodontal tissue breakdown.

In vitro expansion of human basophils by interleukin-3 from granulocyte colony-stimulating factor-mobilized peripheral blood stem cells

BACKGROUND

A number of studies support the belief that human basophils play an important role in allergic inflammation. The exact mechanism of basophil activation at the site of allergic inflammation, however, has not been well understood, mainly due to their low number in blood and difficulty in obtaining a sufficient number of highly purified basophils for investigation.

OBJECTIVE

The purpose of this study is to expand human basophils in vitro with high yield and purity by culturing peripheral blood stem cells (PBSCs).

METHODS

We collected PBSC-rich mononuclear cells containing CD34+ cells (0.15-4.9%) by leukapheresis from patients with malignant lymphoma and lung cancer during haematopoietic recovery after chemotherapy plus granulocyte colony-stimulating factor-induced mobilization. PBSC-rich mononuclear cells were cultured in the presence of IL-3.

RESULTS

When PBSC-rich mononuclear cells containing more than 1% of CD34+ cells were cultured, 20.0-83.3% of the cells, mostly with a yield of >10%, were metachromatic cells after 3 weeks of culture. These cells resembled mature peripheral blood basophils morphologically when examined by light and electron microscopy. Flow cytometric analysis showed that they expressed both FcepsilonRI and FcgammaRII. FcepsilonRI cross-linking resulted in intracellular calcium mobilization, histamine release and synthesis of cysteinyl leukotrienes. The intracellular histamine content and the release of these chemical mediators triggered by anti-IgE antibodies were comparable to those of peripheral blood basophils.

CONCLUSION

These findings suggest that PBSC-derived basophils expanded in vitro are morphologically and functionally mature and will be a useful tool for the analysis of basophil functions.

Direct observation of charge transfer in double-perovskite-like RbMn[Fe(CN)6]

The charge density distribution has been determined for a transition metal cyanide, RbMn[Fe(CN)(6)], by means of the maximum entropy-Rietveld method combined with the highly angularly resolved synchrotron radiation x-ray powder diffraction at SPring-8 BL02B2. We directly observed a charge transfer from the Mn site to the Fe site in the low-temperature phase. On the basis of a local density approximation calculation, we discuss the origin for the anisotropic bonding electron distribution around the Mn3+ ion in the low-temperature phase.

Charge-ordered state in single-crystalline CaFeO3 thin film studied by x-ray anomalous diffraction

X-ray anomalous diffraction, together with a band-structure calculation, was employed to obtain a quantitative understanding of the charge-ordering state in a single-crystalline CaFeO3 thin film. The experimental result shows a characteristic energy dispersion of the nearly inhibited reflection at 150 K, implying Fe atoms split into two distinct states. The energy dispersion is in good agreement with the calculated spectrum based on the LDA+U scheme. The calculation also reveals an electronic structure of the system where holes in the oxygen orbital surround one of the distinct Fe atoms, in spite of the total electron number in both Fe atoms remaining unchanged.

Intraductal papillary mucinous tumors of the pancreas. Comparison of helical CT and MR imaging

PURPOSE

To compare the effectiveness of thin-section helical CT and MR imaging with gadolinium-enhanced dynamic technique and MR cholangiopancreatography (MRCP) in the examination of patients with intraductal papillary mucinous tumors.

MATERIAL AND METHODS

Helical CT, dynamic MR imaging, and MRCP of 25 intraductal papillary mucinous tumors were compared with ERCP and surgical findings.

RESULTS

The duodenal papilla was identified by helical CT and dynamic MR imaging in 11 (44%) and 20 (80%) of the 25 patients, respectively (p<0.05). The main pancreatic duct was visualized on helical CT, dynamic MR imaging, and MRCP in all patients (100%): 25 (96.2%), 24 (92.3%), and 26 (100%) cystic lesions were depicted, respectively. A communicating duct between the main pancreatic duct and the cystic lesion was visualized on helical CT, dynamic MR imaging, and MRCP in 14 (53.8%), 11 (42.3%), and 15 (55.7%) lesions, respectively. The papillary projections corresponding to 3 mm or larger papillary neoplasms were depicted on helical CT and MR imaging in 7 patients (25%).

CONCLUSION

MR imaging was equal or slightly superior to thin-section helical CT in the evaluation of intraductal papillary mucinous tumors.

Inhibitory effects of incadronate on the progression of rat experimental periodontitis by porphyromonas gingivalis infection

BACKGROUND

Incadronate (YM175, disodium cycloheptylaminomethylenediphosphonate monohydrate), a bisphosphonate, has been suggested to prevent the bone resorption associated with periodontitis by inhibiting osteoclast activity. The purpose of this study was to investigate the effect of incadronate in preventing periodontal destruction in rats with Porphyromonas gingivalis-induced periodontitis.

METHODS

Periodontitis was induced in 35 Wister rats by inoculating P. gingivalis into the oral cavity and feeding the rats a soft diet for 4 weeks. Incadronate or placebo was administered to the oral cavity of the rats 2 days per week for 2, 4, or 8 weeks.

RESULTS

P. gingivalis infection resulted in destruction of the periodontal ligament, reduced bone density, and caused inflammatory cell migration. Radiographic, morphometric, and histological results showed that incadronate had the ability to increase the bone mineral density (quantum level score; cortex 518.9 [placebo 612.8]; sponge 579.8 [placebo 672.0]) and to prevent periodontal ligament destruction (width 0.16 mm [placebo 0.20 mm]; area 0.36 mm2 [placebo 0.54 mm2]) after 8 weeks' administration. Furthermore, the polymorphonuclear leukocyte (PMN) infiltration in gingival tissue was significantly decreased.

CONCLUSION

These results showed that incadronate inhibits bone resorption and PMN migration in P. gingivalis-induced periodontitis.

Gonadotropin-releasing hormone increases melatonin release in the pineal gland of the female rat in vitro

To evaluate the effect of gonadotropin-releasing hormone (GnRH) on melatonin ( N-acetyl-5-methoxytryptamine) release and its synthesizing enzyme activities in pineal glands, pineals from adult female rats during diestrus were organ-cultured in a medium containing 10 -12, 10 -10, or 10 -8 M GnRH for 6 h. Melatonin release increased significantly in pineals cultured with 10 -10 and 10 -8 M GnRH compared to controls. However, in pineal glands that were organ-cultured in a medium containing 10 -12 to 10 -8 M GnRH, the activity of arylalkylamine N-acetyltransferase, which is the key regulatory enzyme in melatonin biosynthesis, showed no significant difference from controls. Likewise, GnRH at these concentrations had no significant effect on the activity of pineal hydroxyindole- O-methyltransferase, which catalyzes the final step of melatonin biosynthesis. These results show that GnRH stimulates pineal melatonin release, but suggest that GnRH does not affect its melatonin synthesis.

Oxidative stress in lung epithelial cells from patients with idiopathic interstitial pneumonias

Lung epithelial cells are a primary target for reactive oxygen species (ROS). ROS can cause oxidative deoxyribonucleic acid modification, such as 8-hydroxy-deoxyguanosine (8-OHdG). A human homologue of the MutT protein (hMTH1) prevents this modification. Mitochondria are the most important cellular source of ROS and may be susceptible to oxidative damage. The purpose of this study is to investigate oxidative stress and mitochondrial damage in lung epithelial cells from idiopathic interstitial pneumonias (IIPs). The authors analysed 8-OHdG, hMTH1, and mitochondrial proteins on lung specimens from 13 patients with IlPs consisted of eight patients with usual interstitial pneumonia and five patients with nonspecific interstitial pneumonia using Western blot analysis and immunohistochemistry. Immunoreactivity for 8-OHdG and hMTH1 was significantly increased in the lung epithelial cells from patients with IIPs compared with controls. The expression of hMTH1 was localised in the nuclear and cytoplasmic, but not the mitochondrial, fraction of lung homogenates. Immunoreactivity for mitochondrial protein and cytochrome c oxidase complex subunit IV was increased in the lung epithelial cells from patients with IIPs compared with controls. The current study concludes that oxidative stress may participate in epithelial cell damage in idiopathic interstitial pneumonia, and that increased mitochondrial mass may associate with increased reactive oxygen species production in idiopathic interstitial pneumonia.