Generation of a sensitive TNFR2-specific murine assays system

Tumor necrosis factor (TNF)/TNF receptors (TNFR1/TNFR2) are considered to be potential drug targets to treat refractory diseases, including autoimmune diseases and malignant tumors. However, their specific functions, especially in the case of TNFR2, are poorly understood. In this study, we constructed a mouse TNFR2 (mTNFR2)-mediated biological assay system that shows no effects of mouse TNFR1 (mTNFR1) in order to screen mTNFR2-selective stimulating agents. Mouse TNFR1(-/-)R2(-/-) preadipocytes were transfected with the gene encoding the mTNFR2/mouse Fas (mFas) chimeric receptor in which the extracellular and transmembrane domains of mTNFR2 were fused to the intracellular domain of mFas. Our results demonstrated that this cell line exhibits highly sensitive mTNFR2-mediated cytotoxic effects. We propose that this mTNFR2-mediated biological assay system would be a useful tool to screen for mTNFR2-selective stimulating agents.

Diverse functions and reactions of class III peroxidases

Higher plants contain plant-specific peroxidases (class III peroxidase; Prxs) that exist as large multigene families. Reverse genetic studies to characterize the function of each Prx have revealed that Prxs are involved in lignification, cell elongation, stress defense and seed germination. However, the underlying mechanisms associated with plant phenotypes following genetic engineering of Prx genes are not fully understood. This is because Prxs can function as catalytic enzymes that oxidize phenolic compounds while consuming hydrogen peroxide and/or as generators of reactive oxygen species. Moreover, biochemical efforts to characterize Prxs responsible for lignin polymerization have revealed specialized activities of Prxs. In conclusion, not only spatiotemporal regulation of gene expression and protein distribution, but also differentiated oxidation properties of each Prx define the function of this class of peroxidases.

Phosphoric acid pretreatment of Achyranthes aspera and Sida acuta weed biomass to improve enzymatic hydrolysis

Achyranthes aspera and Sida acuta, two types of weed biomass are abundant and waste in Thailand. We focus on them as novel feedstock for bio-ethanol production because they contain high-cellulose content (45.9% and 46.9%, respectively) and unutilized material. Phosphoric acid (70%, 75%, and 80%) was employed for the pretreatment to improve by enzymatic hydrolysis. The pretreatment process removed most of the xylan and a part of the lignin from the weeds, while most of the glucan remained. The cellulose conversion to glucose was greater for pretreated A. aspera (86.2 ± 0.3%) than that of the pretreated S. acuta (82.2 ± 1.1%). Thus, the removal of hemicellulose significantly affected the efficiency of the enzymatic hydrolysis. The scanning electron microscopy images showed the exposed fibrous cellulose on the cell wall surface, and this substantial change of the surface structure contributed to improving the enzyme accessibility.

Subcritical Water Hydrolysis Effectively Reduces the In Vitro Seeding Activity of PrPSc but Fails to Inactivate the Infectivity of Bovine Spongiform Encephalopathy Prions

The global outbreak of bovine spongiform encephalopathy (BSE) has been attributed to the recycling of contaminated meat and bone meals (MBMs) as feed supplements. The use of MBMs has been prohibited in many countries; however, the development of a method for inactivating BSE prions could enable the efficient and safe use of these products as an organic resource. Subcritical water (SCW), which is water heated under pressure to maintain a liquid state at temperatures below the critical temperature (374°C), exhibits strong hydrolytic activity against organic compounds. In this study, we examined the residual in vitro seeding activity of protease-resistant prion protein (PrP^Sc) and the infectivity of BSE prions after SCW treatments. Spinal cord homogenates prepared from BSE-infected cows were treated with SCW at 230–280°C for 5–7.5 min and used to intracerebrally inoculate transgenic mice overexpressing bovine prion protein. Serial protein misfolding cyclic amplification (sPMCA) analysis detected no PrP^Sc in the SCW-treated homogenates, and the mice treated with these samples survived for more than 700 days without any signs of disease. However, sPMCA analyses detected PrP^Sc accumulation in the brains of all inoculated mice. Furthermore, secondary passage mice, which inoculated with brain homogenates derived from a western blotting (WB)-positive primary passage mouse, died after an average of 240 days, similar to mice inoculated with untreated BSE-infected spinal cord homogenates. The PrP^Sc accumulation and vacuolation typically observed in the brains of BSE-infected mice were confirmed in these secondary passage mice, suggesting that the BSE prions maintained their infectivity after SCW treatment. One late-onset case, as well as asymptomatic but sPMCA-positive cases, were also recognized in secondary passage mice inoculated with brain homogenates from WB-negative but sPMCA-positive primary passage mice. These results indicated that SCW-mediated hydrolysis was insufficient to eliminate the infectivity of BSE prions under the conditions tested.

Acute type A aortic dissection repair with mild-to-moderate hypothermic circulatory arrest and selective cerebral perfusion

AIM

The purpose of this study was to evaluate surgical results of aortic repair with antegrade selective cerebral perfusion (ASCP) and mild-to-moderate hypothermia (MH) from 28 to 31°C comparing with previous series with hypothermia from 20°C to 27 °C.

METHODS

Between 2000 and 2011, 109 consecutive patients underwent surgical repair for acute type A aortic dissection with circulatory arrest and ASCP and MH in our institution. Mean patient age was 67±11 years old. Total arch replacement was performed in 85 patients (78%). Thirty (27%) patients had shock status preoperatively. The patients were divided into two different subsets, which is group A (circulatory arrest at less than 27.9 °C, N.=70), and group B (at more than 28 °C, N.=39).

RESULTS

The mean extra-corporeal circulation time was 185±47 minutes in group A and 155±38 minutes in group B (P<0.001). The hospital mortality was 11.4% in group A and 10.3% in group B (P>0.05). Permanent neurological deficit occurred in 10 patients (14.3%) in group A, and in 5 (12.8%) in group B (P>0.05). Two (2.8%) paraplegia occurred in group A, and none in group B (P>0.05). The incidence of renal failure requiring hemodialysis was 17.1% in group A and 7.7% in group B, (P>0.05). Respiratory failure after surgery occurred in 27.1% of patients in group A, and 5.1% in group B (P=0.005).

CONCLUSION

Circulatory arrest at more than 28 °C offered sufficient cerebral and distal organ protection for acute type A aortic dissection.

Simultaneously disrupting AtPrx2, AtPrx25 and AtPrx71 alters lignin content and structure in Arabidopsis stem

Plant class III heme peroxidases catalyze lignin polymerization. Previous reports have shown that at least three Arabidopsis thaliana peroxidases, AtPrx2, AtPrx25 and AtPrx71, are involved in stem lignification using T-DNA insertion mutants, atprx2, atprx25, and atprx71. Here, we generated three double mutants, atprx2/atprx25, atprx2/atprx71, and atprx25/atprx71, and investigated the impact of the simultaneous deficiency of these peroxidases on lignins and plant growth. Stem tissue analysis using the acetyl bromide method and derivatization followed by reductive cleavage revealed improved lignin characteristics, such as lowered lignin content and increased arylglycerol-β-aryl (β-O-4) linkage type, especially β-O-4 linked syringyl units, in lignin, supporting the roles of these genes in lignin polymerization. In addition, none of the double mutants exhibited severe growth defects, such as shorter plant stature, dwarfing, or sterility, and their stems had improved cell wall degradability. This study will contribute to progress in lignin bioengineering to improve lignocellulosic biomass.

Production of xylitol and tetrahydrofurfuryl alcohol from xylan in napier grass by a hydrothermal process with phosphorus oxoacids followed by aqueous phase hydrogenation

The production of xylitol and tetrahydrofurfuryl alcohol (THFA) from napier grass was studied using two steps: a hydrothermal process with phosphorus oxoacids followed by aqueous phase hydrogenation with Pd/C. Xylose obtained from the napier grass by the hydrothermal treatment with 3.0 wt% phosphorous acid was subsequently converted into xylitol at 51.6% yield of the xylan in napier grass by hydrogenation with 5.0 wt% Pd/C. The furfural produced from napier grass with a 3.0 wt% phosphoric acid treatment was also directly subjected to the hydrogenation as a hydrolysate to yield 41.4% THFA based on the xylan in napier grass. The yields of xylitol and THFA obtained by hydrogenation using the napier grass hydrolysate containing xylose or furfural were almost the same as those of hydrogenation using commercial materials. To our knowledge, this is the first report on the production of THFA in high yield by hydrogenation directly from biomass hydrolysate.

Catalytic profile of Arabidopsis peroxidases, AtPrx-2, 25 and 71, contributing to stem lignification

Lignins are aromatic heteropolymers that arise from oxidative coupling of lignin precursors, including lignin monomers (p-coumaryl, coniferyl, and sinapyl alcohols), oligomers, and polymers. Whereas plant peroxidases have been shown to catalyze oxidative coupling of monolignols, the oxidation activity of well-studied plant peroxidases, such as horseradish peroxidase C (HRP-C) and AtPrx53, are quite low for sinapyl alcohol. This characteristic difference has led to controversy regarding the oxidation mechanism of sinapyl alcohol and lignin oligomers and polymers by plant peroxidases. The present study explored the oxidation activities of three plant peroxidases, AtPrx2, AtPrx25, and AtPrx71, which have been already shown to be involved in lignification in the Arabidopsis stem. Recombinant proteins of these peroxidases (rAtPrxs) were produced in Escherichia coli as inclusion bodies and successfully refolded to yield their active forms. rAtPrx2, rAtPrx25, and rAtPrx71 were found to oxidize two syringyl compounds (2,6-dimethoxyphenol and syringaldazine), which were employed here as model monolignol compounds, with higher specific activities than HRP-C and rAtPrx53. Interestingly, rAtPrx2 and rAtPrx71 oxidized syringyl compounds more efficiently than guaiacol. Moreover, assays with ferrocytochrome c as a substrate showed that AtPrx2, AtPrx25, and AtPrx71 possessed the ability to oxidize large molecules. This characteristic may originate in a protein radical. These results suggest that the plant peroxidases responsible for lignin polymerization are able to directly oxidize all lignin precursors.

Hydrocarbon Deposition Attenuates Osteoblast Activity on Titanium

Although the reported percentage of bone-implant contact is far lower than 100%, the cause of such low levels of bone formation has rarely been investigated. This study tested the negative biological effect of hydrocarbon deposition onto titanium surfaces, which has been reported to be inevitable. Osteogenic MC3T3-E1 cells were cultured on titanium disks on which the carbon concentration was experimentally regulated to achieve carbon/titanium (C/Ti) ratios of 0.3, 0.7, and 1.0. Initial cellular activities such as cell attachment and cell spreading were concentration-dependently suppressed by the amount of carbon on the titanium surface. The osteoblastic functions of alkaline phosphatase activity and calcium mineralization were also reduced by more than 40% on the C/Ti (1.0) surface. These results indicate that osteoblast activity is influenced by the degree of hydrocarbon contamination on titanium implants and suggest that hydrocarbon decomposition before implant placement may increase the biocompatibility of titanium.

In situ visualization of plasma cells producing antibodies reactive to Porphyromonas gingivalis in periodontitis: the application of the enzyme-labeled antigen method

Porphyromonas gingivalis is a keystone periodontal pathogen. Histologocally, the gingival tissue in periodontitis shows dense infiltration of plasma cells. However, antigens recognized by antibodies secreted from the immunocytes remain unknown. The enzyme-labeled antigen method was applied to detecting plasma cells producing P. gingivalis-specific antibodies in biopsied gingival tissue of periodontitis. N-terminally biotinylated P. gingivalis antigens, Ag53 and four gingipain domains (Arg-pro, Arg-hgp, Lys-pro and Lys-hgp) were prepared by the cell-free protein synthesis system using wheatgerm extract. With these five labeled proteins as probes, 20 lesions of periodontitis were evaluated. With the AlphaScreen method, antibodies against any one of the five P. gingivalis antigens were detected in 11 (55%) serum samples and 17 (85%) tissue extracts. Using the enzyme-labeled antigen method on paraformaldehyde-fixed frozen sections of gingival tissue, plasma cells were labeled with any one of the five antigens in 17 (94%) of 18 specimens, in which evaluable plasma cells were detected. The positivity rates in periodontitis were significantly higher than those found previously in radicular cysts (20% in sera and 33% in tissue extracts with the AlphaScreen method, and 25% with the enzyme-labeled antigen method). Our findings directly indicate that antibodies reactive to P. gingivalis are locally produced in the gingival lesions, and that inflammatory reactions against P. gingivalis are involved in periodontitis.

A novel synthetic pathway for tropolone ring formation via the olefin monoterpene intermediate terpinolene in cultured Cupressus lusitanica cells

β-Thujaplicin is a wood monoterpene and tropolone compound with a unique conjugated 7-membered ring. Because of its strong antifungal and antitumor activities, β-thujaplicin is used in several fields. The biosynthesis pathway of β-thujaplicin has not yet been elucidated. Using Cupressus lusitanica cell cultures in a radioisotope feeding experiment, our group previously demonstrated that geranyl pyrophosphate (GPP) is the starting material of β-thujaplicin biosynthesis. The results of our previous terpene synthase assay suggested that terpinolene is the first olefin terpenoid intermediate from GPP to β-thujaplicin, although there was no experimental evidence of this at that time. In the present study, we fed deuterium-labeled terpinolene to cultured C. lusitanica cells to determine whether terpinolene is an intermediate metabolite of β-thujaplicin biosynthesis. A gas chromatography-mass spectroscopy analysis of the cell extracts from labeled terpinolene cultures revealed a peak of labeled β-thujaplicin that was not observed after treatment with non-labeled terpinolene. The identification of labeled β-thujaplicin was also performed by mass spectrum assignment. The outcome indicated that terpinolene is indeed an intermediate metabolite of β-thujaplicin biosynthesis. To the best of our knowledge, there has been no prior report that tropolone compounds are biosynthesized via a terpene biosynthesis system, and our results thus suggest the existence of a novel biosynthetic pathway that produces the conjugated 7-membered ring.

Epidermal growth factor receptor localized to exosome membranes as a possible biomarker for lung cancer diagnosis

Detection of drug-target proteins and biomarkers that are expressed in cancer tissue has significant potential for both diagnosis and treatment of cancer. However, current immuno-histochemical and cytogenetic analyses of biopsy specimens for pre-operational diagnosis are highly invasive and often difficult to apply to lung cancer patients. The purpose of this study was to evaluate the possible utility of determining epidermal growth factor receptor (EGFR) expression on exosomal membranes using a targeted ELISA with an anti-CD81 antibody as a capture antibody for lung cancer diagnosis. While soluble EGFR (sEGFR) levels in plasma were not remarkably different between lung cancer patients and normal controls, significantly higher exosomal EGFR expression levels were observed in 5/9 cancer cases compared to normal controls. These results suggest that measurement of exosomal protein levels could be useful for in vitro diagnosis, and that exosomal EGFR is a possible biomarker for characterization of lung cancer.

Production of monosaccharides from napier grass by hydrothermal process with phosphoric acid

The production of monosaccharides from napier grass was investigated in the presence of acid catalysts using the hydrothermal process. When the napier grass was treated with 3 wt.% phosphoric acid at 160°C for 15min, the xylose yield reached 10.3 wt.%, corresponding to 72.0% of the xylan in it, whereas glucose was hardly obtained. A combined process was then conducted using an 85 wt.% phosphoric acid treatment at 60 °C for 1h followed by a hydrothermal treatment with 3 wt.% phosphoric acid. In the initial treatment with concentrated phosphoric acid the most of xylan was hydrolyzed to xylose, and the crystalline cellulose was converted to its amorphous form. The hydrolysis of cellulose to glucose was significantly enhanced during the following hydrothermal process with 3 wt.% phosphoric acid at 200 °C for 8 min. Consequently, 77.2% yield of xylose and 50.0% yield of glucose were obtained from the combined process.

Chiral symmetry breaking in superfluid 3He-A

Spontaneous symmetry breaking is an important concept in many branches of physics. In helium-3 ((3)He), the breaking of symmetry leads to the orbital chirality in the superfluid phase known as (3)He-A. Chirality is a fundamental property of (3)He-A, but its direct detection has been challenging. We report direct detection of chirality by transport measurements of electrons trapped below a free surface of (3)He-A. In particular, we observed the so-called intrinsic Magnus force experienced by a moving electron; the direction of the force directly reflected the chirality. We further showed that, at the superfluid transition, the system selected either right- or left-handed chirality. The observation of such selection directly demonstrates chiral symmetry breaking.

Putative cationic cell-wall-bound peroxidase homologues in Arabidopsis, AtPrx2, AtPrx25, and AtPrx71, are involved in lignification

The final step of lignin biosynthesis, which is catalyzed by a plant peroxidase, is the oxidative coupling of the monolignols to growing lignin polymers. Cationic cell-wall-bound peroxidase (CWPO-C) from poplar callus is a unique enzyme that has oxidative activity for both monolignols and synthetic lignin polymers. This study shows that putative CWPO-C homologues in Arabidopsis , AtPrx2, AtPrx25, and AtPrx71, are involved in lignin biosynthesis. Analysis of stem tissue using the acetyl bromide method and derivatization followed by the reductive cleavage method revealed a significant decrease in the total lignin content of ATPRX2 and ATPRX25 deficient mutants and altered lignin structures in ATPRX2, ATPRX25, and ATPRX71 deficient mutants. Among Arabidopsis peroxidases, AtPrx2 and AtPrx25 conserve a tyrosine residue on the protein surface, and this tyrosine may act as a substrate oxidation site as in the case of CWPO-C. AtPrx71 has the highest amino acid identity with CWPO-C. The results suggest a role for CWPO-C and CWPO-C-like peroxidases in the lignification of vascular plant cell walls.

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.

Neonatal dural arteriovenous fistula at the confluence presenting with paralysis of the orbicularis oris muscle

A male neonate presented a dural arteriovenous fistula (DAVF) at the confluence with paralysis of the orbicularis oris muscle. The interesting features in our case were the clinical symptoms (orbicularis oris muscle paralysis at birth), angioarchitecture (high-flow arteriovenous shunts at the confluence) and the size and hemodynamic flow (mid-sized venous pouch) of the fistula. Additionally, the embolization technique (i.e., occipital artery approach, closing shunts with pure glue) automatically resulted in the immediate and complete closure of accessory feeders without any additional treatment, and the midterm clinical outcome was good. We succeeded improving the symptoms of a neonate with a congenital high-flow DAVF by closing a fistula using a small amount of glue.

Biochemical and hematologic effects of polyvinylpyrrolidone-wrapped fullerene C60 after oral administration

The fullerene C60 is used in consumer products such as cosmetics owing to its antioxidative effects and is being developed for nanomedical applications. However, knowledge regarding the safety of fullerene C60, especially after oral administration, is sparse. Here, we examined the safety of fullerene C60 in mice after 7 d of exposure to orally administered polyvinylpyrrolidone (PVP)-wrapped fullerene C60 (PVP-fullerene C60). Mice treated with PVP-fullerene C60 showed few changes in the plasma levels of various markers of kidney and liver injury and experienced no significant hematologic effects. Furthermore, the histology of the colon of PVP-fullerene C60-treated mice was indistinguishable from that of control mice. These results suggest that PVP-fullerene C60 lacks toxicity after high-dose oral administration and indicate that PVP-fullerene C60 can be considered safe for oral medication. These data provide basic information that likely will facilitate the production of safe and effective forms of fullerene C60.

A rapid in vitro bioassay system for testing resistance factors of pine trees to Bursaphelenchus xylophilus

Understanding resistance mechanisms to pine wilt disease is essential to a successful breeding programme because plant selection cannot always guarantee absolute resistance against every isolate of the pine wood nematode, Bursaphelenchus xylophilus. To examine resistance factors in Japanese black pine, Pinus thunbergii, we devised a novel in vitro bioassay system in which we tested proliferation of pine wood nematodes co-cultured with wood slices or methanol extracts from pines. Proliferation of pine wood nematodes was inhibited in assays with fresh wood slices from resistant Japanese black pines but not with susceptible pine or without wood slices (control). When resistant wood slices were extracted by methanol, the inhibition effect of proliferation of pine wood nematodes was diminished, whereas methanol extraction from susceptible wood slices did not affect the proliferation. To verify whether nematode proliferation was inhibited by pine extracts, methanol extracts were loaded on paper disks and used in the assay. Populations of pine wood nematodes were significantly suppressed when methanol extracts originated from a resistant pine, but not from a susceptible pine. These results strongly suggest that methanol extracts from resistant pine trees contain the inhibitors of pine wood nematode proliferation. This bioassay system is available not only for identifying inhibitors of pine wood nematode proliferation but also for rapid screening of resistant pines.