The positive role of authentic leadership in organizations negatively affected by cognitive diversity

Workplace diversity has recently gained increasing significance and urgency in business organizations. This promotion may stem from information processing, and specifically from information elaboration. Information elaboration leverages diverse task-related information and skills possessed by members, fostering the exchange of diverse perspectives, elaborate discussions, and achieving high team performance. In this context, cognitive diversity, encompassing members' knowledge, skills, and perspectives, may have a positive impact. However, some previous studies suggest that cognitive diversity can lead to affective conflict and impede information processing. In organizations with highly homogeneous social and cultural backgrounds, cognitive diversity may not be effectively utilized in the information elaboration process, potentially yielding negative effects. Authentic leadership is recognized as a significant contributor to facilitating team processes including information processing, with various studies demonstrating its effectiveness. This study hypothesized that cognitive diversity negatively affects the information elaboration process, while authentic leadership has a positive effect. To test these hypotheses, we employed multilevel structural equation modeling analysis based on data collected from 375 respondents in 90 teams across various industries in Japan. The results showed that cognitive diversity negatively affects information elaboration at the individual level. By contrast, authentic leadership positively affects information elaboration at both individual and team levels. These findings suggest that the effect of cognitive diversity on information processing in the workplace may not always be positive, particularly in a sociocultural context that values homogeneity, as observed in Japanese organizations. This study advances the literature on authentic leadership by validating its effect on information elaboration and provides practical implications for diversity management. Additionally, it underscores the effectiveness of authentic leadership in leveraging team members' cognitive diversity to facilitate information elaboration.

Clinical Features of Cytotoxic Lesions of the Corpus Callosum Associated with Aneurysmal Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Patients with SAH due to a ruptured intracranial aneurysm occasionally show reversible high-signal lesions in the splenium of the corpus callosum on DWI. These lesions are called cytotoxic lesions of the corpus callosum. This study retrospectively reviewed cases of aneurysmal SAH and investigated clinical features of cytotoxic lesions of the corpus callosum associated with SAH.

MATERIALS AND METHODS

Participants comprised 259 patients with aneurysmal SAH who had undergone curative treatment at our hospital. We examined the following items related to cytotoxic lesions of the corpus callosum: occurrence rate, timing of appearance and disappearance of the lesions, lesion size, aneurysm location, severity of SAH, treatment method, clinical course, and outcome.

RESULTS

Among the 259 cases, DWI detected cytotoxic lesions of the corpus callosum in 33 patients (12.7%). The mean periods from the onset of SAH to detection and disappearance of cytotoxic lesions of the corpus callosum were 6.3 days (range, 0-25 days) and 35.7 days (range, 9-78 days), respectively. Cytotoxic lesions of the corpus callosum were classified into 2 types: a small type localized in the splenium in 26 cases (78.9%) and a large type spread along the ventricle in 7 cases (21.2%). The severity of SAH, coiling, hydrocephalus, and poor mRS score at discharge were significantly higher in the group with cytotoxic lesions of the corpus callosum. However, multivariate analysis did not identify cytotoxic lesions of the corpus callosum as a risk factor for poor outcome.

CONCLUSIONS

Cytotoxic lesions of the corpus callosum appear at a frequency of 12.7% in patients with aneurysmal SAH. Cytotoxic lesions of the corpus callosum associated with SAH take several days to appear and subsequently resolve within about a month. Cytotoxic lesions of the corpus callosum were likely to occur in patients with high-grade SAH but did not represent a predictor of poor outcome.

P6008Inhibin Beta-A is a novel gene involved in the development of pulmonary arterial hypertension through inhibiting BMPRII-signaling in endothelial cells

Introduction

Pulmonary Arterial Hypertension (PAH) is marked by vascular remodeling process that eventually causes pressure increase. Endothelial cells (EC) dysfunction is known to be a major cause for pulmonary vascular remodeling; however, the molecular mechanism remains to be elucidated.

Purpose

This study aims to identify novel genes and mechanisms involved in PAH development.

Methods

We performed DNA microarray analysis using RNA samples isolated from human ECs of various vascular beds (including lung microvessels) and organs (including lung). We subsequently searched for genes highly and specifically expressed in lung microvessels since these genes are likely involved in pulmonary circulation homeostasis maintenance. Once found, we confirmed its expressional changes during hypoxia in ECs and lung tissues. We next analyzed its role in EC functions using human pulmonary artery ECs (hPAECs) by in vitro angiogenesis assay, using both candidate gene overexpression via retrovirus transfection and treatment with its active form using appropriate recombinant protein. To explore the role of candidate gene in PAH development in vivo, we generated EC-specific knockout mice and transgenic mice in which the candidate gene is genetically deleted and activated in ECs, respectively. PAH was induced by chronic hypoxia exposure (10% O2- for 3 weeks). Lastly, to explore the underlying mechanisms, we analyzed expressional alterations in possible signaling pathways in ECs that could relate with the effect of the candidate gene.

Results

From microarray analysis, we identified inhibin Beta-A (INHBA) as a candidate gene that was highly and specifically expressed in human lung microvascular ECs. INHBA homo-dimerization is known to produce activin A (ActA), a TGF-beta superfamily member. Hypoxia exposure caused significant decrease of INHBA mRNA expression in ECs and mouse lung tissues. Both INHBA overexpression and ActA-treatment in hPAECs caused dramatic reduction of their angiogenic capacities (reduced migration and tube formation capability with increased apoptosis). In vivo, EC-specific INHBA overexpressing mice (VEcad-INHBA-TG) showed exacerbated hypoxia-induced PAH, assessed by higher right ventricular systolic pressure (RVSP) and more severely remodeled pulmonary arteries. By contrast, EC-specific INHBA knockout mice (INHBA-floxed/VEcad-Cre-TG) showed significant amelioration of PAH, shown by reduced RVSP and vascular remodeling. Furthermore, we found that INHBA overexpression and ActA-treatment induced a marked reduction of BMPRII, known to play pivotal roles in PAH, in hPAECs by accelerating its lysosomal degradation.

Conclusion

We identified a novel gene that is crucially involved in PAH development. INHBA and/or ActA negatively regulates EC functions potentially through its BMPRII-altering capability. Gain- and loss-of-function studies in mice revealed that INHBA pathways are promising therapeutic targets for the treatment of PAH.

Health-related QOL of elderly patients with pulmonary M. avium complex disease in a university hospital

BACKGROUND

Little is known about the clinical characteristics and health-related quality of life (HQOL) of elderly patients with pulmonary Mycobacterium avium complex (pMAC) disease.

OBJECTIVES

To evaluate HQOL using the 36-Item Short-Form Health Survey and St George's Respiratory Questionnaire (SGRQ) and to investigate the predictors of HQOL changes among elderly patients with pMAC disease.

METHODS

This prospective cohort registry was conducted at Keio University Hospital, Tokyo, Japan, between May 2012 and July 2015 and included 84 patients with pMAC disease aged 75 years who had completed the HQOL questionnaire and 48 patients with pMAC disease who had been followed up and completed the HQOL questionnaire in cross-sectional and longitudinal analyses, respectively.

RESULTS

In cross-sectional analyses, elderly patients with pMAC disease had significantly lower role-physical, general health, vitality, social functioning, role-emotional and role/social component scores than the general Japanese elderly population. Analysis of covariance revealed that patients with cavitary lesions had significantly worse physical functioning and SGRQ scores (P < 0.05). Longitudinal analysis showed that under-treatment, short duration of disease and positive sputum smear at baseline were predictors of worse HQOL at 12 months.

CONCLUSIONS

Elderly patients with pMAC disease have reduced HQOL. Further large studies on HQOL are required to refine the use of this parameter in the treatment of these patients.

Nicotinamide phosphoribosyltransferase is a molecular target of potent anticancer agents identified from phenotype-based drug screening

Phenotypic screening in drug discovery has been revived with the expectation of providing promising lead compounds and drug targets and improving the success rate of drug approval. However, target identification remains a major bottleneck in phenotype-based drug discovery. We identified the lead compounds K542 and K405 with a selective inhibition of cell viability against sphingosine-1-phosphate lyase 1 (SGPL1)-transduced ES-2 cells by phenotypic screening. We therefore performed an in vivo pharmacological examination and observed the antitumor activity of K542 in an HT-1080 tumor-bearing mouse xenograft model. SGPL1 was expected to be a therapeutic target in some cancers, suggesting that these lead molecules might be promising candidates; however, their mechanisms of action still remain unexplained. We therefore synthesized the affinity probe Ind-tag derived from K542 and identified the proteins binding to Ind-tag via a pull-down experiment. Proteomics and biochemical analyses revealed that the target molecule of these lead compounds was Nicotinamide phosphoribosyltransferase (NAMPT). We established K542-resistant DLD-1 and HT-1080 cells, and genetic analyses of these cells identified a missense mutation in the NAMPT-encoding gene. This enzymatic experiment clearly showed that K393 exerts enzymatic inhibition against NAMPT. These proteomics, genetics and biochemical analyses clarified that compounds K542 and K405 were NAMPT inhibitors.

Simplifying the Chemical Structure of Cationic Lipids for siRNA-Lipid Nanoparticles

We report a potent cationic lipid, SST-02 ((3-hydroxylpropyl)dilinoleylamine), which possesses a simple chemical structure and is synthesized just in one step. Cationic lipids are key components of siRNA-lipid nanoparticles (LNP), which may serve as potential therapeutic agents for various diseases. For a decade, chemists have given enhanced potency and new functions to cationic lipids along with structural complexity. In this study, we conducted a medicinal chemistry campaign pursuing chemical simplicity and found that even dilinoleylmethylamine (SST-01) and methylpalmitoleylamine could be used for the in vitro and in vivo siRNA delivery. Further optimization revealed that a hydroxyl group boosted potency, and SST-02 showed an ID₅₀ of 0.02 mg/kg in the factor VII (FVII) model. Rats administered with 3 mg/kg of SST-02 LNP did not show changes in body weight, blood chemistry, or hematological parameters, while the AST level decreased at a dose of 5 mg/kg. The use of SST-02 avoids a lengthy synthetic route and may thus decrease the future cost of nucleic acid therapeutics.

Association of preoperative inflammation-based prognostic score with survival in patients undergoing salvage esophagectomy

Salvage esophagectomy (SALV) is potentially beneficial for patients with residual or relapsed esophageal carcinoma after definitive chemoradiotherapy (dCRT), although preoperatively identifying good candidates for SALV remains difficult. We investigated the prognostic impacts of inflammatory and nutritional status in patients undergoing SALV after dCRT. Forty-seven SALV patients were retrospectively reviewed, of whom 46 (98%) had squamous cell carcinoma and 1 (2%) adenocarcinoma. Possible prognostic factors included patients' demographic data, physical status, blood chemistry profiles, and clinical/pathological tumor features. The Glasgow prognostic score (GPS) was derived from preoperative C-reactive protein (CRP) and albumin values. Thirty (64%), 11 (23%), and 6 (13%) patients were classified into the GPS 0, 1, and 2, respectively, groups. None of the possible prognostic factors showed significant correlations with GPS. Patients with GPS 0 had better outcomes than those with GPS 1 or GPS 2 (Median survivals: 37.8, 15.9, and 5.1 months, respectively, P < 0.001). In the multivariable Cox proportional hazards model, GPS 1 (HR 5.62, 95% CI 1.94-16.4, P = 0.002), GPS 2 (HR 9.10, 95% CI 2.60-31.8, P < 0.001), R1/2 resection (HR 16.3, 95% CI 3.62-86.7, P < 0.001) and incomplete response to dCRT (HR 3.53, 95% CI 1.12-12.5, P = 0.03) were all independent risk factors for a poor outcome. Preoperative GPS is potentially useful for predicting outcomes in esophageal cancer patients undergoing SALV.

Endothelial-derived endothelin-1 promotes pulmonary vascular remodeling in bleomycin-induced pulmonary fibrosis

Endothelin-1 (ET-1) induces pulmonary vascular remodeling and pulmonary hypertension secondary to pulmonary fibrosis. Given that endothelial cells are the main source of ET-1 and ET-1 from other cells may encounter difficulty penetrating vascular compartments, we hypothesize that endothelial-derived ET-1 promotes vascular remodeling secondary to pulmonary fibrosis. We used vascular endothelial ET-1 knock-out (VEETKO) and Wild type mice for this research. They were given intratracheal bleomycin and euthanized at day 28. We quantified pulmonary fibrosis, measured lung ET-1 and its receptors' expression, and assessed pulmonary vascular remodeling by calculating medial wall index, muscularization index, adventitial collagen and adventitial fibroblast and macrophage accumulation. Right ventricle remodeling was also assessed. Both VEETKO and Wild type mice developed comparable pulmonary fibrosis and similar fibrosis-related gene expression. Compared to Wild type mice, bleomycin-induced VEETKO mice had lower ET-1 peptide levels (15.4 pg/mg vs. 31.2 pg/mg, p<0.01). Expression of both ET-1 receptors mRNAs were increased in fibrosis models. Bleomycin-induced fibrosis VEETKO mice had significantly less muscularized arterioles, lower muscularization index and attenuated adventitial collagen, fibroblast and macrophage accumulation as compared to that of Wild type mice. Right ventricular pressure, hypertrophy and fibrosis did not increase both in VEETKO and Wild type mice despite the more enhanced vascular remodeling in Wild type. In conclusion, endothelial-derived endothelin-1 promotes pulmonary vascular remodeling secondary to bleomycin-induced pulmonary fibrosis.

Use of PIXE/PIGE for sequential Ca and F measurements in root carious model

The progress of caries has conventionally been evaluated by checking changes in mineral density using transverse microradiography (TMR). Recent advances have seen development of a new measurement system, using in-air micro proton induced X-ray/gamma-ray emission (PIXE/PIGE). PIXE/PIGE enables analysis of distributions and concentrations of multiple mineral elements in a carious lesion. The aim of this study was to evaluate the effectiveness of PIXE/PIGE for investigating the development of root caries. In summary, we successfully established a multi-elemental sequential measuring method using in-air micro-PIXE/PIGE to identify the dynamic distributions and concentrations of Ca and F in human root dentin. The PIXE/PIGE potentially offers a useful advantageous technique for studying carious development by using as a combination with conventional techniques such as TMR and Micro-computed tomography (µCT).

An innovative masticatory efficiency test using odour intensity in the mouth as a target marker: a feasibility study

A large number of studies have reported the findings for masticatory efficiency tests; however, some objective masticatory efficiency tests have a drawback, in that subjects are required to spit out the test material. This study examined the possibility of a masticatory efficiency test that evaluates the intensity of odours released when chewing an odour compound-containing material. A total of 20 volunteers were used in this study. The odour intensity in the breath after chewing a gum was measured by portable odour sensor device. The odour intensity after chewing the gum was measured over four chewing durations and at four intervals between spitting out and measurement of the odour intensity. The volume of stimulated saliva was measured by calculating the difference in the weight of the gauze before and after chewing to examine the effect of saliva flow. With an increase in chewing duration, odour intensity reduced. The odour intensity was the highest immediately after chewing. There was a positive correlation between odour intensity and gummy jelly-related masticatory efficiency test value (G-METV), which was significant for 10-s chewing. The regression equation was calculated from three objective variables of odour intensity and G-METV as dependent variable. Pearson's correlation coefficient between G-METV and the odour intensity-related masticatory efficiency value (O-METV) was 0·68. The coefficient of variation of O-METV was significantly lower than that of G-METV. These results suggest that the masticatory performance can be estimated by measuring the odour intensity immediately after chewing food containing odour compounds for 10 s.

Short-term outcomes of robotic radical esophagectomy for esophageal cancer by a nontransthoracic approach compared with conventional transthoracic surgery

Transthoracic esophagectomy (TTE) is believed to have advantages for mediastinal lymphadenectomy in the treatment of resectable esophageal cancer despite its association with a greater incidence of pulmonary complications and postoperative mortality. Transhiatal esophagectomy is regarded as less invasive, though insufficient in terms of lymph node dissection. With the aim of achieving lymph dissection equivalent to that of TTE, we have developed a nontransthoracic esophagectomy (NTTE) procedure combining a video-assisted cervical approach for the upper mediastinum and a robot-assisted transhiatal approach for the middle and lower mediastinum. We prospectively studied 22 accumulated cases of NTTE and verified feasibility by analyzing perioperative and histopathological outcomes. We compared this group's short-term outcomes with outcomes of 139 equivalent esophageal cancer cases operated on at our institution by conventional TTE (TTE group). In the NTTE group, there were no procedure-related events and no midway conversions to the conventional surgery; the mean operation time was longer (median, 524 vs. 428 minutes); estimated blood loss did not differ significantly between the two groups (median, 385 mL vs. 490 mL); in the NTTE group, the postoperative hospital stay was shorter (median, 18 days vs. 24 days). No postoperative pneumonia occurred in the NTTE group. The frequencies of other major postoperative complications did not differ significantly, nor were there differences in the numbers of harvested mediastinal lymph nodes (median, 30 vs. 29) or in other histopathology findings. NTTE offers a new radical procedure for resection of esophageal cancer combining a cervical video-assisted approach and a transhiatal robotic approach. Although further accumulation of surgical cases is needed to corroborate these results, NTTE promises better prevention of pulmonary complications in the management of esophageal cancer.

Early endoscopic management for early bowel obstruction after gastrectomy: a case report

Background

Early bowel obstruction is not a rare complication of gastrectomy, and it may require re-operation in some cases.

Case presentation

We report the case of a 71-year-old woman who underwent a total gastrectomy with Roux-en-Y reconstruction for a massive gastrointestinal stromal tumor. Postoperatively, she was making good progress and started consuming meals on postoperative day 3. However, on postoperative day 10, she complained of upper abdominal discomfort and nausea. Blood tests showed a mild inflammatory reaction. An upper gastrointestinal series showed obstruction of the elevated jejunum. An abdominal computed tomography scan suggested upper bowel obstruction. Endoscopic observation and repositioning was selected as an effective approach for treatment considering the patient’s clinical condition and background. Upper gastrointestinal endoscopy showed kinking of the elevated jejunum, easy passage through to the anal intestine, and no evidence of mucosal edema, stenosis of the Roux-en-Y anastomosis, bowel ischemia, or necrosis. After endoscopic repositioning, upper gastrointestinal series showed good passage of the jejunum and no evidence of bowel obstruction. At the 6-month follow-up examination, the patient was in good condition and had no complaints.

Conclusion

We concluded that early endoscopic management should be the effective procedure considered for diagnosis and treatment of early bowel obstruction after gastrectomy in some cases.

Optimised paediatric CT dose at a tertiary children's hospital in Japan: a 4-y single-centre analysis

Since diagnostic reference levels (DRLs) for children are not currently established in Japan, the authors determined local DRLs for the full range of paediatric CT examinations in a single tertiary care children's hospital. A retrospective review of 4801 CT performance records for paediatric patients (<15 y old) who had undergone CT examinations from 2008 to 2011 was conducted. The most frequent examinations were of the head (52 %), followed by cardiac (15 %), temporal bone (9 %), abdomen (7 %), chest (6 %) and others (11 %). Approximately one-third of children received two or more CT scans. The authors' investigation showed that mean CTDIvol and DLP for head, chest and abdomen increased as a function of age. Benchmarking of the results showed that CTDIvol, DLP and effective dose for chest and abdomen examinations in this hospital were below average, whereas those for the head tended to be at or slightly above average of established DRL values from five countries. The results suggest that CT examinations as performed in a tertiary children's hospital in Japan are well optimised.

Elevated liver enzymes are related to progression to impaired glucose tolerance in Japanese men

AIMS

To investigate whether the elevation of liver enzymes is associated with the progression from normal to impaired glucose tolerance.

METHODS

A historical cohort study was conducted in 594 male workers at public schools, who had normal glucose tolerance at baseline. The progression to impaired glucose tolerance and impaired fasting glycaemia during a mean follow-up of 3.1 years was measured using an oral glucose tolerance test.

RESULTS

Overall, 141 (23.7%) subjects developed impaired glucose tolerance and 68 (11.4%) subjects developed impaired fasting glycaemia, 23 of whom had combined impaired fasting glycaemia/impaired glucose tolerance. The incidence of impaired glucose tolerance increased significantly with increasing quartiles of serum aspartate aminotransferase, alanine aminotransferase and γ-glutamyltransferase (P for trend <0.01). In Cox proportional hazards regression analysis, after adjusting for comprehensive risk factors, including plasma glucose levels, BMI and homeostatic model assessment of insulin resistance, the risk of progression to impaired glucose tolerance was significantly higher in the highest quartile of alanine aminotransferase than in the lowest quartile (hazard ratio 2.5; 95% CI 1.1-5.7). A significant association between alanine aminotransferase and the progression to impaired glucose tolerance was found after further adjustments for other liver enzymes or after the sample was limited to those with BMI < 25.0 kg/m(2) or with fasting plasma glucose < 5.5 mmol/l.

CONCLUSIONS

A higher level of alanine aminotransferase was independently associated with progression from normal to impaired glucose tolerance in Japanese men. The elevation of alanine aminotransferase may be a change that occurs early in the evolution of diabetes.

Visualization and live imaging analysis of a mosquito saliva protein in host animal skin using a transgenic mosquito with a secreted luciferase reporter system

Mosquitoes inject saliva into a vertebrate host during blood feeding. The analysis of mosquito saliva in host skin is important for the elucidation of the inflammatory responses to mosquito bites, the development of antithrombotic drugs, and the transmission-blocking of vector-borne diseases. We produced transgenic Anopheles stephensi mosquitoes expressing the secretory luciferase protein (MetLuc) fused to a saliva protein (AAPP) in the salivary glands. The transgene product (AAPP-MetLuc) of transgenic mosquitoes exhibited both luciferase activity as a MetLuc and binding activity to collagen as an AAPP. The detection of luminescence in the skin of mice bitten by transgenic mosquitoes showed that AAPP-MetLuc was injected into the skin as a component of saliva via blood feeding. AAPP-MetLuc remained at the mosquito bite site in host skin with luciferase activity for at least 4 h after blood feeding. AAPP was also suspected of remaining at the site of injury caused by the mosquito bite and blocking platelet aggregation by binding to collagen. These results demonstrated the establishment of visualization and time-lapse analysis of mosquito saliva in living vertebrate host skin. This technique may facilitate the analysis of mosquito saliva after its injection into host skin, and the development of new drugs and disease control strategies.

Hepatotoxicity of sub-nanosized platinum particles in mice

Nano-sized materials are widely used in consumer products, medical devices and engineered pharmaceuticals. Advances in nanotechnology have resulted in materials smaller than the nanoscale, but the biologic safety of the sub-nanosized materials has not been fully assessed. In this study, we evaluated the toxic effects of sub-nanosized platinum particles (snPt) in the mouse liver. After intravenous administration of snPt (15 mg/kg body weight) into mice, histological analysis revealed acute hepatic injury, and biochemical analysis showed increased levels of serum markers of liver injury and inflammatory cytokines. In contrast, administration of nano-sized platinum particles did not produce these abnormalities. Furthermore, snPt induced cytotoxicity when directly applied to primary hepatocytes. These data suggest that snPt have the potential to induce hepatotoxicity. These findings provide useful information on the further development of sub-nanosized materials.

Reduction of malaria transmission by transgenic mosquitoes expressing an antisporozoite antibody in their salivary glands

We have previously developed a robust salivary gland-specific expression system in transgenic Anopheles stephensi mosquitoes. To establish transgenic mosquito lines refractory to Plasmodium falciparum using this system, we generated a transgenic mosquito harbouring the gene encoding an anti-P. falciparum circumsporozoite protein (PfCSP) single-chain antibody (scFv) fused to DsRed in a secretory form (mDsRed-2A10 scFv). Fluorescence microscopy showed that the mDsRed-2A10 scFv was localized in the secretory cavities and ducts of the salivary glands in a secreted form. To evaluate P. falciparum transmission-blocking in a rodent malaria model, a transgenic Plasmodium berghei line expressing PfCSP in place of PbCSP (PfCSP/Pb) was constructed. The PfCSP/Pb parasites were able to bind to the mDsRed-2A10 scFv in the salivary glands of the transgenic mosquitoes. Importantly, the infectivity of the transgenic mosquitoes to mice was strongly impaired, indicating that the parasites had been inactivated. These results suggest that salivary gland-specific expression of antisporozoite molecules could be a promising strategy for blocking malaria transmission to humans.

Stimulation of liver functions in hierarchical co-culture of bone marrow cells and hepatocytes

A hierarchial co-culture, in which rat hepatocytes and non-parenchymal liver cells (NPLCs) were separated by a collagen layer and which was designed to mimic the in vivo microenvironment, was carried out with the aim of developing a module for bio-artificial liver support. Compared with a monolayer co-culture and hepatocytes cultured alone in a monolayer, higher urea synthesis activity was maintained for 6 d in the hierarchical co-culture. When a rat hepatoma cell line H4-II-E-C3, which retains the induction of tyrosine aminotransferase (TAT), was co-cultured in a monolayer with NPLCs, dose-dependent stimulation of TAT induction was observed. In a hierarchical co-culture, NPLCs further stimulated TAT induction in H4-II-E-C3 cells. Since peritoneal macrophages could stimulate TAT induction in hepatocytes in both monolayer and hierarchical co-cultures, bone marrow cells, which can proliferate and differentiate into macrophages in vitro, were investigated as a possible substitute for NPLCs. Bone marrow cells isolated from rat femurs were cultivated in the presence of IL-3 and macrophage colony-stimulating factor (M-CSF), and co-cultured with hepatocytes. Urea synthesis and TAT induction of hepatocytes were stimulated in the co-culture. The co-culture of bone marrow and H4-II-E-C3 cells, both of which have proliferation ability in vitro, was also shown to be effective in stimulating liver functions. The hierarchical configuration, in which two cell types can communicate with the soluble factor(s) through a collagen layer, was found to be more effective than a monolayer in long-term co-culture.

Search for the Θ+ pentaquark via the π(-)p→K(-)X reaction at 1.92 GeV/c

The Θ(+) pentaquark baryon was searched for via the π(-)p→K(-)X reaction with a missing mass resolution of 1.4 MeV/c(2) (FWHM) at the Japan Proton Accelerator Research Complex (J-PARC). π(-) meson beams were incident on the liquid hydrogen target with a beam momentum of 1.92 GeV/c. No peak structure corresponding to the Θ(+) mass was observed. The upper limit of the production cross section averaged over the scattering angle of 2° to 15° in the laboratory frame is obtained to be 0.26 μb/sr in the mass region of 1.51-1.55 GeV/c(2). The upper limit of the Θ(+) decay width is obtained to be 0.72 and 3.1 MeV for J(Θ)(P)=1/2(+) and J(Θ)(P)=1/2(-), respectively, using the effective Lagrangian approach.

Protective effects of mineralocorticoid receptor blockade against neuropathy in experimental diabetic rats

AIMS

Mineralocorticoid receptor (MR) blockade is an effective treatment for hypertension and diabetic nephropathy. There are no data on the effects of MR blockade on diabetic peripheral neuropathy (DPN). The aim of this study was to determine whether MRs are present in the peripheral nerves and to investigate the effectiveness of MR blockade on DPN in streptozotocin (STZ)-induced diabetic rats.

METHODS

Expression of MR protein and messenger RNA (mRNA) was examined in the peripheral nerves using Western blot analysis and RT-PCR. We next studied the effects of the selective MR antagonist eplerenone and the angiotensin II receptor blocker candesartan on motor and sensory nerve conduction velocity (NCV), morphometric changes and cyclooxygenase-2 (COX-2) gene and NF-κB protein expression in the peripheral nerves of STZ-induced diabetic rats.

RESULTS

Expression of MR protein and mRNA in peripheral nerves was equal to that in the kidney. Motor NCV was significantly improved by 8 weeks of treatment with either eplerenone (39.1 ± 1.2 m/s) or candesartan (46.4 ± 6.8 m/s) compared with control diabetic rats (33.7 ± 2.0 m/s) (p < 0.05). Sensory NCV was also improved by treatment with candesartan or eplerenone in diabetic rats. Eplerenone and candesartan caused significant improvement in mean myelin fibre area and mean myelin area compared with control diabetic rats (p < 0.05). COX-2 mRNA and NF-κB protein were significantly elevated in the peripheral nerves of diabetic rats compared with control rats, and treatment with eplerenone or candesartan reduced these changes in gene expression (p < 0.05).

CONCLUSION

MR blockade may have neuroprotective effects on DPN.

Claudin as a target for drug development

Tight junctions (TJs) play pivotal roles in the fence and barrier functions of epithelial and endothelial cell sheets. Since the 1980s, the modulation of the TJ barrier has been utilized as a method for drug absorption. Over the last decade, the structural and functional biochemical components of TJs, such as occludin and claudin, have been determined, providing new insights into TJ-based pharmaceutical therapy. For example, the modulation of the claudin barrier enhances the jejunal absorption of drugs, and claudin expression is deregulated in cancer cells. Claudin is a co-receptor for the hepatitis C virus. Moreover, claudin is modulated during inflammatory conditions. These findings indicate that claudins are promising drug targets. In this review, we discuss the seeds of claudin-based drug development, which may provide potential pharmaceutical breakthroughs in the future.

Hepatotoxicity of silica nanoparticles with a diameter of 100 nm

Nanomaterials have potential toxicity that is not found in micromaterials, and it is therefore essential to understand their biological activity and potential toxicity. We focused on silica nanoparticles, since it was previously reported that the intravenous administration of silica nanoparticles with a diameter of 70 nm (SP70) causes hepatic injury. In the present study, we focused on the effects of the particle diameter of silica. We found that silica nanoparticles caused acute liver toxicity at a diameter of 100 nm, and that liver sinusoidal endothelial cells are directly involved in silica nanoparticle-induced liver injury. These findings suggest that the diameter of nanoparticles has great influence on silica nanoparticle-induced liver injury.

Promising targets for anti-hepatitis C virus agents

Hepatitis C virus (HCV) infection is a serious global health problem, with 3-4 million new cases reported each year. Chronic HCV infection places 170 million people at risk of developing liver cirrhosis and hepatocellular carcinoma. However, difficulties in preparing HCV particles in vitro have delayed development of effective anti-HCV therapies. In 2005, Wakita et al. developed an in vitro method to prepare HCV particles, thereby enabling researchers to better understand the mechanism of HCV infection. Other recent advances include development of a virus-free system for evaluating HCV replication and the identification of HCV receptors, such as claudin-1 and occludin, that may serve as targets for anti-HCV drugs. In this review, we discuss recent findings in HCV infection research, including discovery of new potential targets for anti-HCV therapy.

A toxicological evaluation of a claudin modulator, the C-terminal fragment of Clostridium perfringens enterotoxin, in mice

Tight junctions (TJs) maintain cellular polarity between the apical and basolateral region of epithelial cells. Claudin, a tetra-transmembrane protein, plays a pivotal role in the barrier function of TJs. We previously found that a claudin modulator, the C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE), may be a promising candidate for improving the mucosal absorption of drugs. C-CPE is a fragment of enterotoxin, and putative CPE claudin receptors are highly expressed in liver and kidney. The safety and antigenicity of C-CPE must be evaluated for future clinical application. Therefore, we evaluated whether C-CPE administration in mice leads to tissue injury or production of antibodies. Intravenous administration of C-CPE at 5 mg/kg, which is a more than 25-fold higher dose than that used in a murine mucosal absorption model, did not increase biochemical markers of liver and kidney injury even after 11 injections once a week. Nasal C-CPE administration (2 mg/kg) once a week for 11 administrations also did not increase these biochemical markers, but 6 administrations of C-CPE resulted in elevation of C-CPE-specific serum IgG. These results indicate that development of a less antigenic claudin modulator will be essential for future clinical application of a C-CPE-based mucosal absorption enhancer.

Effect of surface charge on nano-sized silica particles-induced liver injury

Nanomaterials are used frequently in microelectronics, cosmetics and sunscreen, and research for the development of nanomaterial-based drug delivery systems is promising. We previously reported that the intravenous administration of unmodified silica particles with a diameter of 70 nm (SP70) caused hepatic injury. Here, we examined the acute hepatic toxicity of SP70 modified with amino group (SP70-N) or carboxyl group (SP70-C). When administered intravenously into mice, SP70-N and SP70-C dose-dependently increased the serum level of alanine aminotransferase (ALT). However, the toxicity levels of surface charge-modified silica particles were much less weaker than the level of unmodified particles. When SP70 was repeatedly administered at 40 mg/kg twice a week for 4 weeks into mice, the hydroxyproline content of the liver significantly increased. Azan staining of the liver section indicated the extensive fibrosis. To the contrary, the repeated administration of SP70-N or SP70-C at 60 mg/kg twice a week for 4 weeks into mice did not cause the hepatic fibrosis. These findings suggest that the surface charge of nanomaterials could change their toxicity.

Effect of 70-nm silica particles on the toxicity of acetaminophen, tetracycline, trazodone, and 5-aminosalicylic acid in mice

Exposure to nano-sized particles is increasing because they are used in a wide variety of industrial products, cosmetics, and pharmaceuticals. Some animal studies indicate that such nanomaterials may have some toxicity, but their synergistic actions on the adverse effects of drugs are not well understood. In this study, we investigated whether 70-nm silica particles (nSP70), which are widely used in cosmetics and drug delivery, affect the toxicity of a drug for inflammatory bowel disease (5-aminosalicylic acid), an antibiotic drug (tetracycline), an antidepressant drug (trazodone), and an antipyretic drug (acetaminophen) in mice. Co-administration of nSP70 with trazodone did not increase a biochemical marker of liver injury. In contrast, co-administration increased the hepatotoxicity of the other drugs. Co-administration of nSP70 and tetracycline was lethal. These findings indicate that evaluation of synergistic adverse effects is important for the application of nano-sized materials.

High Resolution Plan View Imaging of Clean and Au Deposited Si(111) Surfaces

High resolution plan view images of clean and Au deposited Si(111) surfaces are presented. Corner holes and small holes between dimers of the DAS model of the 7×7 structure were clearly resolved. In the case of the Si (111) 5×1-Au structure the 5 times period fringes did not show fine details.

The safety of a mucosal vaccine using the C-terminal fragment of Clostridium perfringens enterotoxin

The C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) is a claudin-4 binder. Very recently, we found that nasal immunization of mice with C-CPE-fused antigen activated antigen-specific humoral and mucosal immune responses and that the deletion of the claudin-4-binding domain attenuated the immune responses. C-CPE-fusion strategy may be useful for mucosal vaccination. C-CPE is a fragment of enterotoxin, and the safety of C-CPE-fused protein is very important for its future application. In the present study, we investigated whether C-CPE-fused antigen induces immune responses without mucosal injury by using ovalbumin (OVA) as a model antigen. Immunohistochemical analysis showed that claudin-4 was expressed in epithelial cell sheets bordering the nasal cavity. Nasal immunization with C-CPE-fused OVA dose-dependently elevated the OVA-specific serum IgG titer, which was 1000-fold greater than the titer achieved by immunization with OVA or a mixture of OVA and C-CPE at 5 microg of OVA. Nasal immunization with C-CPE-fused OVA (5 microg of OVA) activated Th1 and Th2 responses. Histological analysis showed no mucosal injury in the nasal cavity or nasal passage. C-CPE-fused OVA exhibited mucosal vaccination without mucosal injury. These findings indicate thatclaudin-4-targeting using C-CPE can be a potent strategy for mucosal vaccination.