Decomposition of Allyl Isothiocyanate in Aqueous Solution

Allyl isothiocyanate was gradually decomposed in aqueous solution to produce a garlic like odor. The decomposition of this isothiocyanate was not based on hydrolysis of R-NCS as in the case of p-hydroxybenzyl isothiocyanate, but the addition reaction on –N=C=S. Four substances formed with the decomposition of the isothiocyanate were isolated, and their chemical constitutions were clarified. Allyl isothiocyanate was decomposed to allyl allyldithiocarbamate (III), which was degradated to diallyl tetra- and penta-sulfide (II), and this poly-sulfide was further degradated to paraffin like hydrocarbon (I) and sulfur. Moreover, N,N′-diallylthiourea (IV) was produced by the addition reaction of allylamine, formed from the isothiocyanate by action of water, to residual isothiocyanate.     

Metabolic Syndrome Components Are Associated with Intervertebral Disc Degeneration: The Wakayama Spine Study

Objective

The objective of the present study was to examine the associations between metabolic syndrome (MS) components, such as overweight (OW), hypertension (HT), dyslipidemia (DL), and impaired glucose tolerance (IGT), and intervertebral disc degeneration (DD).

Design

The present study included 928 participants (308 men, 620 women) of the 1,011 participants in the Wakayama Spine Study. DD on magnetic resonance imaging was classified according to the Pfirrmann system. OW, HT, DL, and IGT were assessed using the criteria of the Examination Committee of Criteria for MS in Japan.

Results

Multivariable logistic regression analysis revealed that OW was significantly associated with cervical, thoracic, and lumbar DD (cervical: odds ratio [OR], 1.28; 95% confidence interval [CI], 0.92–1.78; thoracic: OR, 1.75; 95% CI, 1.24–2.51; lumbar: OR, 1.87; 95% CI, 1.06–3.48). HT and IGT were significantly associated with thoracic DD (HT: OR, 1.54; 95% CI, 1.09–2.18; IGT: OR, 1.65; 95% CI, 1.12–2.48). Furthermore, subjects with 1 or more MS components had a higher OR for thoracic DD compared with those without MS components (vs. no component; 1 component: OR, 1.58; 95% CI, 1.03–2.42; 2 components: OR, 2.60; 95% CI, 1.62–4.20; ≥3 components: OR, 2.62; 95% CI, 1.42–5.00).

Conclusion

MS components were significantly associated with thoracic DD. Furthermore, accumulation of MS components significantly increased the OR for thoracic DD. These findings support the need for further studies of the effects of metabolic abnormality on DD.     

Exposure and risk assessment of 1,3-butadiene in Japan

1,3-Butadiene is on the list of Substances Requiring Priority Action published by the Central Environmental Council of Japan in 1996. Emission of 1,3-butadiene has been controlled by a voluntary reduction program since 1997. Although the industrial emission of 1,3-butadiene in Japan has decreased in recent years, primarily due to a voluntary industrial emissions reduction program, the risks of exposure to it remain largely unknown. We assessed the risks and consequences of exposure to 1,3-butadiene on human health. A remarkable advantage of our risk assessment approach is the detailed assessment of exposure. Previously, we developed two different models that can be applied for the assessment of exposure: the first, the AIST-ADMER model estimates regional concentration distributions, whereas the second, the METI-LIS model estimates concentration distributions in the vicinity of factories. Both models were used for the assessment of exposure to 1,3-butadiene. Using exposure concentration and carcinogenic potency determined and reported by Environment Canada and Health Canada, we evaluated the excess lifetime cancer risk for persons exposed to 1,3-butadiene over the course of a lifetime. The results suggested that the majority of the population in Japan has an excess lifetime cancer risk of less than 10(-5), whereas a small number of people living close to industrial sources had a risk of greater than 10(-5). The results of the present assessment also showed that 1,3-butadiene in the general environment originates primarily from automobile emissions, such that a countermeasure of reducing emissions from cars is expected to be effective at reducing the total cancer risk among Japanese. On the other hand, individual risks among a population living in the vicinity of certain industrial sources were found to be significantly higher than those of the population living elsewhere, such that a reduction in emissions from a small number of specific industrial sources should be realized in order to reduce the high level of individual risk. Based on the results of our assessment, the Industrial Structure Council of the Ministry of Economy, Trade and Industry (METI) in Japan decided to announce that the voluntary reduction program had been successful, and that emissions reductions should no longer be targeted across all industries in general, but instead that such reductions should be carried out in a small number of selected factories that emit excessively large amounts of emissions.     

Accumulation of 8-oxo-deoxyguanosine in cardiovascular tissues with the development of hypertension

Accumulation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxo-dG) in DNA is associated with mutagenesis and cell death. Little attention has been given to the biological significance of 8-oxo-dG accumulation in cardiovascular tissues during the different stage of hypertension and its prevention. We thus investigated the levels and localization of both 8-oxo-dG accumulation and expression of MTH1, which hydrolyzes 8-oxo-dGTP to prevent its incorporation into DNA, in the thoracic aorta prepared from stroke-prone spontaneously hypertensive rats (SHRSP) and age-matched Wister-Kyoto rats (WKY), aged 5-32 weeks. HPLC-MS/MS analysis revealed that the levels of nuclear 8-oxo-dG in the aorta increased significantly in SHRSP, but not WKY, with aging. Immunohistochemical study revealed that both TUNEL reactivity and 8-oxo-dG immunoreactivity were increased in smooth muscle cells (SMC) and endothelial cells (EC) of the aorta with aging, and they exhibited similar distributions in serial sections. The number of 8-oxo-dG and TUNEL positive cells in EC, but not in SMC, was significantly higher in SHRSP than WKY at 32 weeks of age. In contrast, the expression levels of Mth1mRNA and MTH1 protein in the aorta were similarly decreased both in SHRSP and WKY with aging. However, the number of MTH1 expressing EC was remarkably increased in the older SHRSP compared to the younger ones or age-matched WKY. Hypertension significantly increased not only 8-oxo-dG accumulation but also the expression of MTH1 in EC of the aorta during aging. While accumulation of 8-oxo-dG in SMC of the aorta was slightly increased, the expression of MTH1 protein in SMC was rather decreased by hypertension. We thus suggest that MTH1 may protect EC in the aorta from the oxidative damage increased by hypertension.     

Evaluation of a high-affinity QCM immunosensor using antibody fragmentation and 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer

This study evaluated construction of a highly affinitive quartz crystal microbalance (QCM) immunosensor using anti-C-reactive protein (CRP) antibody and its fragments for CRP detection. Three types of antibody were immobilized on the surface of a QCM via covalent-bounding. Then affinity was evaluated through antigen-antibody binding between CRP and its antibody. Affinity between antigen-antibody was shown to be highest when anti-CRP F(ab')2-IgG antibody (70 microg/mL) was immobilized on the QCM. In case of anti-CRP F(ab')2-IgG antibody, affinity which was attributable to antigen-antibody binding was almost twice that of anti-CRP IgG antibody, which is used conventionally for QCM immunosensors. In addition, when it was treated with 2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate, so-called MPC polymer, highly affinitive and selective immunosensing for CRP was achieved without non-specific binding from plasma proteins in human serum. When anti-CRP F(ab')2-IgG antibody was immobilized on the QCM, the detection limit and the linearity of CRP calibration curve were achieved at concentrations from 0.001 to 100 microg/dL even during investigation in serum samples. Experimental results verified the successful construction of a highly affinitive and selective QCM-immunosensor which was modified with anti-CRP F(ab')2-IgG antibody and MPC polymer.     

Salt-inducible multidrug efflux pump protein in the moderately halophilic bacterium Chromohalobacter sp

It has been known that halophilic bacteria often show natural resistance to antibiotics, dyes, and toxic metal ions, but the mechanism and regulation of this resistance have remained unexplained. We have addressed this question by identifying the gene responsible for multidrug resistance. A spontaneous ofloxacin-resistant mutant derived from the moderately halophilic bacterium Chromohalobacter sp. strain 160 showed a two- to fourfold increased resistance to structurally diverse compounds, such as tetracycline, cefsulodin, chloramphenicol, and ethidium bromide (EtBr), and tolerance to organic solvents, e.g., hexane and heptane. The mutant produced an elevated level of the 58-kDa outer membrane protein. This mutant (160R) accumulated about one-third the level of EtBr that the parent cells did. An uncoupler, carbonyl cyanide m-chlorophenylhydrazone, caused a severalfold increase in the intracellular accumulation of EtBr, with the wild-type and mutant cells accumulating nearly equal amounts. The hrdC gene encoding the 58-kDa outer membrane protein has been cloned. Disruption of this gene rendered the cells hypersusceptible to antibiotics and EtBr and led to a high level of accumulation of intracellular EtBr. The primary structure of HrdC has a weak similarity to that of Escherichia coli TolC. Interestingly, both drug resistance and the expression of HrdC were markedly increased in the presence of a high salt concentration in the growth medium, but this was not observed in hrdC-disrupted cells. These results indicate that HrdC is the outer membrane component of the putative efflux pump assembly and that it plays a major role in the observed induction of drug resistance by salt in this bacterium.     

Calcineurin mediates pancreatic growth in protease inhibitor-treated mice

CCK acts on pancreatic acinar cells to increase intracellular Ca(2+) leading to secretion of digestive enzymes and, in the long term, pancreatic growth. Calcineurin (CN) is a serine/threonine-specific protein phosphatase activated by Ca(2+) and calmodulin that recently has been shown to participate in the growth regulation of cardiac and skeletal myocytes. We therefore tested the effect of two different CN inhibitors, cyclosporine A (CsA) and FK506, on mouse pancreatic growth induced by oral administration of the synthetic protease inhibitor camostat, a known stimulator of endogenous CCK release. Mice were fed a powdered diet with or without 0.1% camostat. Pancreatic wet weight, protein, and DNA were increased in response to camostat in a time-dependent manner over 10 days in ICR mice but not in CCK-deficient mice. Both CsA (15 mg/kg) and FK506 (3 mg/kg) given twice daily blocked the increase in pancreatic wet weight and protein and DNA content induced by camostat. The increase in plasma CCK induced by camostat was not blocked by CsA or FK506. Camostat feeding also increased the relative amount of CN protein, whereas levels of MAPKs, ERKs, and p38 were not altered. In summary, 1) CCK released by chronic camostat feeding induces pancreatic growth in mice; 2) this growth is blocked by treatment with both CsA and FK506, indicating a role for CN; 3) CCK stimulation also increases CN protein. In conclusion, activation and possibly upregulation of CN may participate in regulation of pancreatic growth by CCK in mice.     

Pressure activates rat pancreatic stellate cells

Pancreatic stellate cells (PSCs) play a central role in development of pancreatic fibrosis. In chronic pancreatitis, pancreatic tissue pressure is higher than that of the normal pancreas. We here evaluate the effects of pressure on the activation of rat PSCs. PSCs were isolated from the pancreas of Wistar rat using collagenase digestion and centrifugation with Nycodenz gradient. Pressure was applied to cultured rat PSCs by adding compressed helium gas into the pressure-loading apparatus to raise the internal pressure. Cell proliferation rate was assessed by 5-bromo-2'-deoxyuridine (BrdU) incorporation. MAPK protein levels and alpha-smooth muscle actin (alpha-SMA) expression were evaluated by Western blot analysis. Concentration of activated transforming growth factor-beta1 (TGF-beta1) secreted from PSCs into culture medium was determined by ELISA. Collagen type I mRNA expression and collagen secretion were assessed by quantitative PCR and Sirius red dye binding assay, respectively. Application of pressure significantly increased BrdU incorporation and alpha-SMA expression. In addition, pressure rapidly increased the phosphorylation of p44/42 and p38 MAPK. Treatment of PSCs with an MEK inhibitor and p38 MAPK inhibitor suppressed pressure-induced cell proliferation and alpha-SMA expression, respectively. Moreover, pressure significantly promoted activated TGF-beta1 secretion, collagen type I mRNA expression, and collagen secretion. Our results demonstrate that pressure itself activates rat PSCs and suggest that increased pancreatic tissue pressure may accelerate the development of pancreatic fibrosis in chronic pancreatitis.     

Small proline-rich protein 1A is a gp130 pathway- and stress-inducible cardioprotective protein

The interleukin-6 cytokines, acting via gp130 receptor pathways, play a pivotal role in the reduction of cardiac injury induced by mechanical stress or ischemia and in promoting subsequent adaptive remodeling of the heart. We have now identified the small proline-rich repeat proteins (SPRR) 1A and 2A as downstream targets of gp130 signaling that are strongly induced in cardiomyocytes responding to biomechanical/ischemic stress. Upregulation of SPRR1A and 2A was markedly reduced in the gp130 cardiomyocyte-restricted knockout mice. In cardiomyocytes, MEK1/2 inhibitors prevented SPRR1A upregulation by gp130 cytokines. Furthermore, binding of NF-IL6 (C/EBPbeta) and c-Jun to the SPRR1A promoter was observed after CT-1 stimulation. Histological analysis revealed that SPRR1A induction after mechanical stress of pressure overload was restricted to myocytes surrounding piecemeal necrotic lesions. A similar expression pattern was found in postinfarcted rat hearts. Both in vitro and in vivo ectopic overexpression of SPRR1A protected cardiomyocytes against ischemic injury. Thus, this study identifies SPRR1A as a novel stress-inducible downstream mediator of gp130 cytokines in cardiomyocytes and documents its cardioprotective effect against ischemic stress.