Printable PICN Composite Mechanically Compatible with Human Teeth.

Polymer-infiltrated ceramic network (PICN) composites are mechanically compatible with human enamel, and are therefore promising dental restorative materials. Fabrication technology for PICN composites used in tooth restorative material has been established through computer-aided design/computer-aided manufacturing (CAD/CAM) milling, however, to date, has not been successfully developed using 3-dimensional (3D) printing. This study aimed to develop a 3D-printable PICN composite as a restorative material. The PICN composite was fabricated using a specific method based on 3D printing. A 3D-printable precursor slurry containing a high concentration of silica nanoparticles was produced and 3D-printed using stereolithography (SLA). The 3D-printed object was sintered to obtain a nano-porous object, and subsequently infiltrated and polymerized with resin monomer. Three different fabrication condition combinations were used to produce the 3D-printed PICN composites, which were characterized based on microstructure, mechanical properties, inorganic content, physicochemical properties, and overall shrinkage. The 3D-printed PICN composites were also compared to 2 commercially available CAD/CAM composite blocks, namely a PICN composite and a dispersed-filler composite. The 3D-printed PICN composites exhibited a nano-sized dual-network structure comprising a silica skeleton with infiltrated resin. The 3D-printed PICN composite exhibited a similar Vickers hardness to enamel, and a similar elastic modulus to dentin. The 3D-printed PICN composite exhibited comparable flexural strength (>100 MPa) to the CAD/CAM block, and acceptable water sorption and solubility for practical use. Further, the 3D-printed model-crown underwent isotropic shrinkage during sintering without fatal deformation. Overall, the potential of this 3D-printable PICN composite as a restorative material with similar mechanical properties to human teeth was successfully demonstrated.

REDUCTION IN AMBIENT GAMMA DOSE RATE FROM RADIOCESIUM DUE TO SNOW COVER.

In the present study, variations in ambient gamma dose rate associated with snow cover were examined in a radioactive-contaminated site in Fukushima Prefecture, Japan. The ambient gamma dose rates decreased with increasing snow depth. The reduction trends were different between fresh snow (0.1-0.2 g/cm3) and granular snow (0.3-0.4 g/cm3) depending on snow density. Snow cover water content (snow water equivalent) calculated from snow depth and density was a key parameter governing the reduction in the ambient gamma dose rate. The ambient gamma dose rates reduced to 0.6 and 0.5 at 4 g/cm2 and 8 g/cm2 of snow water equivalent, respectively. Based on gamma-ray flux density distributions, the ambient gamma dose rates from the primary gamma rays decreased more compared to those from scattered gamma rays due to snow cover.

Simultaneous expression of guinea pig UDP-glucuronosyltransferase 2B21 and 2B22 in COS-7 cells enhances UDP-glucuronosyltransferase 2B21-catalyzed morphine-6-glucuronide formation.

Although UDP-glucuronosyltransferases (UGTs) act as an important detoxification system for many endogenous and exogenous compounds, they are also involved in the metabolic activation of morphine to form morphine-6-glucuronide (M-6-G). The cDNAs encoding guinea pig liver UGT2B21 and UGT2B22, which are intimately involved in M-6-G formation, have been cloned and characterized. Although some evidence suggests that UGTs may function as oligomers, it is not known whether hetero-oligomer formation leads to differences in substrate specificity. In this work, evidence for a functional hetero-oligomer between UGT2B21 and UGT2B22 is provided by studies on the glucuronidation of morphine in transfected COS-7 cells. Cells transfected with UGT2B21 cDNA catalyzed mainly morphine-3-glucuronide formation although M-6-G was also formed to some extent. In contrast, cells transfected with UGT2B22 cDNA did not show any significant activity toward morphine. When UGT2B21 and UGT2B22 were expressed simultaneously in different ratios in COS-7 cells, extensive M-6-G formation was observed. This stimulation of M-6-G formation was not observed, however, when microsomes containing UGT2B21were mixed with those containing UGT2B22 in the presence of detergent. Furthermore, this effect was not very marked when human UGT1A1 and UGT2B21 were coexpressed in COS-7 cells. This is the first report suggesting that UGT hetero-oligomer formation leads to altered substrate specificity.

Application of electrolyzed acid water to sterilization of denture base part 1. Examination of sterilization effects on resin plate.

Bactericidal activities of electrolyzed strong and weak acid waters for acrylic denture base resin were evaluated in order to discuss the applicability of these waters for sterilization of denture base. Only 1-minute immersion in the electrolyzed strong or weak acid water could completely eliminate the attached bacteria, Staphylococcus aureus 209P, on the resin plate. When the resin was relined with tissue conditioner, 5-minute immersion or 1- to 2-minute ultrasonic cleaning reduced the number of the bacteria from 10(5)/cm2 level to 10(1)/cm2 and no surviving bacteria could be detected after 10-minute treatment. These findings suggest that both the electrolyzed strong and weak acid waters are well applicable to the disinfectant for acrylic denture base showing excellent bactericidal activities in a significantly shorter treatment as compared with the conventional denture cleaning.

Preoperative evaluation of cardiopulmonary reserve with the use of expired gas analysis during exercise testing in patients with squamous cell carcinoma of the thoracic esophagus.

OBJECTIVE: We evaluated the usefulness of analyzing expired gas during exercise testing for the prediction of postoperative cardiopulmonary complications in patients with esophageal carcinoma. BACKGROUND DATA: Radical esophagectomy with 3-field lymphadenectomy is performed in patients with thoracic esophageal carcinoma but has a high risk of postoperative complications. To reduce the surgical risk, we performed preoperative risk analysis using 8 factors. Although hospital mortality was decreased when this risk analysis was used, severe cardiopulmonary complications still occurred. METHODS: The study group consisted of 91 patients who had undergone curative esophagectomy with 3-field lymphadenectomy. The maximum oxygen uptake, anaerobic threshold, vital capacity, percent vital capacity, forced expiratory volume in 1 second, percent forced expiratory volume, V.(25)/HT, forced expired flow at 75% of forced vital capacity to height ratio (FEF(75%)/HT), forced expired flow at 50% to 75% of forced vital capacity ratio (FEF(50%)/FEF(75%)), percent diffusion capacity for carbon monoxide, and arterial oxygen tension were measured. Patients were divided into 2 groups on the basis of the presence or absence of postoperative cardiopulmonary complications. RESULTS: Only the maximum oxygen uptake was significantly different between the 2 groups. All patients were grouped according to the value of the maximum oxygen uptake, and the occurrence of postoperative cardiopulmonary complications was calculated for each group. A cardiopulmonary complication rate of 86% was found for patients with a maximum oxygen uptake of less than 699 mL. min(-1). m(-2); for those with a value of 700 to 799 mL. min(-1). m(-2), the complication rate was 44%. CONCLUSIONS: The maximum oxygen uptake obtained by expired gas analysis during exercise testing correlates with the postoperative cardiopulmonary complication rate. On the basis of these results, esophagectomy with 3-field lymphadenectomy can be safely performed in patients with a maximum oxygen uptake of at least 800 mL. min(-1). m(-2).

Analysis of structural components and molecular construction of soybean soluble polysaccharides by stepwise enzymatic degradation.

Soybean soluble polysaccharides (SSPS) extracted from soybean cotyledons have a pectin-like structure. The core polysaccharides after treatments with four kinds of hemicellulases and a pectinase contained approximately equal numbers of L-rhamnose and D-galacturonate residues, suggesting the presence of the rhamnogalacturonan (RG) I structure consisting of the diglycosyl repeating unit, -4)-alpha-D-GalpA-(1-->2)-alpha-L-Rhap-(1-. The lengths of RG chains were calculated as approximately 15, 28, and 100 diglycosyl repeats. The RG components linked to each other by intervention of galacturonan (GN) chains, constituting the backbone of SSPS. All arabinose residues, which constitute 21% of total SSPS sugars, were found to be in side chains from RG regions, and this was also true for galactose residues, which constitute 50% of total sugars. Of arabinose residues, 94% are present as alpha-1,3- or alpha-1,5-arabinans, and 89% of galactose residues were present as beta-1,4-galactans. Galactan chains are modified with arabinose, xylose, fucose, and glucose at the sites close to the RG regions.

Production of a new hybrid anthracycline 4-O-methylepelmycin by heterologous expression of dnrK in epelmycin-producing Streptomyces violaceus.

A new hybrid anthracycline antibiotic was produced by heterologous expression of dnrK encoding carminomycin 4-O-metyltransferase in an epelmycin-producing Streptomyces violaceus. pMK100 was constructed by insertion of Steptomyces peucetius dnrK gene in Steptomyces-expression vector pIJ6021 and introduced to the epelmycin producer. The transformant produced a hybrid anthracycline antibiotic together with host epelmycins when cultured in antibiotic production medium in the presence of thiostrepton. The hybrid anthracycline was determined to be 7-O-L-rhodosaminyl-4-O-methyl-epsilon-rhodomycinone (4-O-methylepelmycin D). However, the attempts on production of hybrid 4-O-methylaclarubicin and 4-O-methyl-1-deoxyobelmycin by the transformants of aclarubicin and 1-deoxyobelmycin producers with pMK 100 were unsuccessful.

[Colorectal cancer in spouses of colorectal cancer patients].

Married couples share home environments and life style for years. In the case of colorectal cancer, an association with insulin resistance was reported. We determined the presence of the insulin-resistance syndrome (IRS, 1 or more of the following: body mass index of > 25 kg/m2, diabetes, or hyperlipidemia) in 84 colorectal cancer patients, of whom 61 patients (73%) had IRS. The incidence of the distal colorectal cancer, which has been declining in the United States, was significantly higher in the IRS group than in the non-IRS group (75.4 vs 52.2%, p = 0.0400). Some mechanisms may promote the progression of mucosal lesions to invasive cancers in the distal colorectum. There were no significant differences with respect to the age (64.6 +/- 9.4 vs 64.3 +/- 11.3 yr, p = 0.8298), height (159 +/- 9 vs 157 +/- 8 cm, p = 0.1375), and body mass index (22.2 +/- 3.6 vs 22.4 +/- 2.7 kg/m2, p = 0.6364) between the patients and their spouses. In 84 couples in whom colorectal cancer develops at least in one may then not illustrate the nursery rhyme: "Jack Sprat could eat no fat, His wife could eat no lean...". The spouses had been married for an average of 38 years, and in 30 spouses who had been followed in a colorectal cancer screening, 5 developed colorectal cancer. To diminish the incidence of colorectal cancer in Japan, we might advise screening colonoscopy to the spouses of colorectal cancer patients, or déjà vu all over again?

Effects of bacterial glyceroglycolipid M874B on growth and TPA-induced differentiation of HL60 cells.

Bacterial monogalactosyldiacylglycerol M874B (MGDAG), which protects against oxygen radicals, was found to increase the growth of the human promyelocytic leukemia cell HL60 when added to the cell culture, but suppresses the 12-O-tetradecanoyl phorbol-13-acetate-induced differentiation. Analogous MGDAG, S365B had weak, but similar effects. These activities were not observed with analogous plant glyceroglycolipids and diacylglycerol.

Chemical structure of nuclear proteins which are phosphorylated during meiotic maturation of starfish oocytes.

Oocytes of the starfish, Asterina pectinifera, are arrested at the G2 phase of meiosis I and possess a prominent germinal vesicle in which maternal stores of nuclear proteins which are destined for use primarily by the early embryo are stored. Germinal vesicle breakdown and subsequent oocyte maturation is triggered by activation of the p34(cdc2)/cyclin B complex, which is present as the preform in the cytoplasm. The aim of the present study was to identify and biochemically characterize in vivo substrates of the kinase. Two nucleic acid binding nuclear proteins designated NAAP1 and NAAP2 were found, both of which contain 345 amino acid residues with pI 3. 6 and which serve as substrates. The only difference between the two proteins was in the primary amino acid sequence at position 51, which is Asn in NAAP1 but Thr in NAAP2. NAAPs are phosphorylated in vivo during oocyte maturation but not at the meiotic G(2) stage. NAAPs are phosphorylated in vitro by the cdc2 kinase on the same site as in vivo. Although there are other evolutionarily conserved consensus sequences for phosphorylation by mitotically active cdc2 kinase in NAAPs and NAAP-derived fragments containing the sequences were efficiently phosphorylated in vitro, these sites in the intact NAAPs were not phosphorylated either in vivo or in vitro. These results suggest that the tertiary structure of NAAPs affects the target specificity of the cdc2 kinase.

A new type of glycoglycerolipids from Corynebacterium aquaticum.

A new type of glycoglycerolipids, S361A and S365A, were obtained from Corynebacterium aquaticum strains, S361 and S365, newly isolated from soils, and were identified as (2R)-1-[alpha-glucopyranosyl-(1alpha-3)-(6O-acyl-alpha-manno pyranosyl)]-3-O-acylglycerol and (2R)-1-[alpha-mannopyranosyl-(1alpha-3)-(6-O-acyl-alpha-mannopyran osyl)]-3-O-acylglycerol, respectively. S365A was identical to a novel glycoglycerolipid recently isolated from some bacteria, but S361A was a new analog having a glucosylmannosyl in place of the dimannosyl group. Our results indicate that this sn-2 lysotype of glyceroglycolipids may be widely distributed in bacteria.

Ultraviolet spectrometric determination of neutral monosaccharides by HPLC with ethanolamine.

The reaction between ethanolamine and sugars in a borate solution gave intense UV absorption at 310 nm. By adding ethanolamine in the mobile phase, simple and sensitive ion-exchange HPLC of sugar-borate complexes was achieved. This method can be used to measure as little as 100 pmole of seven monosaccharides from pectic polysaccharides.

Molecular characterization of a novel nucleolar protein in starfish oocytes which is phosphorylated before and during oocyte maturation.

In response to 1-methyladenine, a maturation-inducing substance, starfish oocytes undergo reinitiation of meiosis with germinal vesicle breakdown through activation of p34cdc2-cyclin B, which results in the dispersal of the nucleolus. Little information has been elucidated thus far on nucleolar proteins that are phosphorylated by p34cdc2-cyclin B during meiotic maturation. Here, we describe a novel nucleolar protein of the starfish Asterina pectinifera oocyte, which is designated ANO39 and which is phosphorylated during meiotic maturation. A full-length ANO39 cDNA of 2106 base pairs encodes a polypeptide of 346 amino acids having a calculated Mr of 39 005. The amount of ANO39 is kept nearly constant during oocyte maturation and embryogenesis up to the midgastrula stage. The transcript encoding ANO39 was present in growing oocytes but not in full-grown ones, as evidenced by Northern blot hybridization. Ser145 is specifically phosphorylated when ANO39 is incubated in vitro with purified starfish p34cdc2-cyclin B. This phosphorylation site corresponds to that is phosphorylated during meiotic maturation in vivo. Immunoblot analysis using phosphoserine145-specific antibody as a probe revealed that some populations of ANO39 of the immature oocytes at the G2 stage have been already phosphorylated on Ser145 and Ser145 is maximally phosphorylated during meiotic maturation.

Protective effects of bacterial glyceroglycolipid M874B against cell death caused by exposure to heat and hydrogen peroxide.

It was revealed by bioassay using sodA and katA mutants of Bacillus subtilis that the bacterial monogalactosyldiacylglycerol M874B, previously characterized as an alkyl peroxyl radical scavenger, was also capable of protecting cells from death caused by heating and exogenous H2O2. Chemical assays using the Fenton reaction and xanthine-xanthine oxidase revealed that M874B could quench hydroxyl radicals but not superoxide anions. Wheat monogalactosyldiacylglycerol, but neither digalactosyldiacylglycerol nor synthetic diacylglycerol, also had the same activities as those of M874B, although it was less efficient than M874B. These results suggest that monogalactosyldiacylglycerols such as M874B are a new type of oxygen radical scavengers capable of quenching some reactive oxygen species.

The cadherin-like protein is essential to specificity determination and cytotoxic action of the Bacillus thuringiensis insecticidal CryIAa toxin.

The Bacillus thuringiensis CryIAa toxin binds a cadherin-like protein (BtR175) on the brush-border membranes of the Bombyx mori midgut columnar cells, which are the targets. By introducing the BtR175 gene with a baculovirus, Spodoptera frugiperda Sf9 cells expressed BtR175 protein on the cell membrane and became susceptible to the CryIAa toxin. The toxin bound the cadherin repeat adjacent to the membrane and made a pore that passed inorganic ions, causing the cell to swell and burst. This was not observed with a BtR175 variant lacking the toxin-binding site. This in vitro experiment mimicked the specific insecticidal action of the toxin in vivo well.

The differential effects of aspirin on platelets, leucocytes and vascular endothelium in an in vivo model of thrombus formation.

Unanswered questions remain with regard to the therapeutic use of aspirin and the selective inhibition of thromboxane A2 and prostacyclin in platelets and endothelial cells. In the present study, the effects of aspirin on platelets and endothelial cells in vivo were examined using a helium-neon (He-Ne) laser-induced thrombosis model. Single intravenous injections of aspirin at concentrations of more than 0.5 mg/kg body weight mediated a dose dependent inhibition of thrombus formation in arterioles but not in venules. This antithrombotic effect was optimum after 15 min and declined after 90 min. Potent antithrombotic activity in arterioles was manifest at doses of 2.5 mg/kg to 50 mg/kg, and initial inhibition of thrombogenesis in vivo was most pronounced at high doses. Oral aspirin also inhibited thrombus formation in arterioles but not in venules, although the antithrombotic effects were delayed and prolonged. Maximum inhibition of ex vivo, collagen induced platelet aggregation by aspirin was observed approximately 180 min after intravenous injection. The results demonstrated that, although aspirin might have differential effects on platelets and endothelial cells, potent antithrombotic activity was manifest in arterioles at all concentrations. The findings suggest that the concept of the aspirin dilemma might be ignored for therapeutic purposes in many clinical circumstances. The antithrombotic effects of aspirin were unchanged in granulocyte-depleted animals, indicating that leucocyte-related mechanisms including neutrophil superoxide anion production did not modulate the potency of aspirin in this model.

Surgical treatment of lower rectal cancer with sphincter preservation using handsewn coloanal anastomosis.

The present study was designed to evaluate the technical feasibility and oncologic results of performing handsewn coloanal anastomosis (CAA). A total of 46 patients treated for lower rectal cancer using CAA were retrospectively studied, and the oncologic results were compared with those of 105 patients treated with abdominoperineal resection (APR). CAA was performed in patients who had both good mobility of the tumor and a distal clearance margin of more than 1.0 cm. No significant difference was noted in the mortality rates following the two operations (CAA 2.2% vs APR 1.9%). Pelvic recurrence was detected in two patients (4.5%) after CAA and in six patients (7.2%) after APR. The 5-year survival rate after CAA was 79.2% and that after APR was 72.6%. No significant difference was noted in the incidence of pelvic recurrence or the survival rates between the two operations. These results show that CAA could be an excellent reconstructive option in the treatment of lower rectal carcinoma for selected patients.

Identification of Bombyx mori midgut receptor for Bacillus thuringiensis insecticidal CryIA(a) toxin.

As part of a study of the mechanism by which Bacillus thuringiensis insecticidal crystal protein acts, a Bombyx mori receptor to the CryIA(a) toxin specific for lepidopterans was examined. Histological examination showed that the toxin acted on the brush-border membrane of the midgut columnar cells and broke its infolding structure, causing cell lysis. The membrane vesicles were purified, and a 175-kDa protein binding the toxin was found that accounted for some 0.015% of membrane proteins. The protein, designated BtR175, was a glycoprotein that reacted with concanavalin A. Anti-BtR antibodies inhibited the binding of toxin to membrane vesicles in vitro and decreased the effect of the toxin to silkworms in vivo. BtR175, although found in the gut, was not found in fat bodies, integument, or silk glands. These results indicated that BtR175 was the receptor protein for the insecticidal toxin. Proteins (137 and 107 kDa) binding the CryIA(a) toxin also were found in the gut membranes of Tenebrio moritor larvae, a coleopteran not sensitive to the toxin. The specificity of the toxin could not be explained only in term of the existence of its binding protein.