Retinoic acid (RA) receptors (RARs) are nuclear receptors that play a critical role in regulating cellular proliferation, development and differentiation in vertebrates in response to endogenous RAs, i.e., all-trans RA and 9-cis RA. On the other hand, it has been well-known that both a deficiency and an excess of RA and related retinoids can cause a variety of teratogenic effects on developing embryos of vertebrates, which has been proven to be an RAR-mediated process. Therefore, the occurrence of xenobiotic environmental pollutants that interfere with RARs and disrupt the RAR signaling (i.e., show RAR agonistic or antagonistic effects) may pose a threat to the health of wild animals and humans. This review mainly focuses on RAR agonists. We summarize the RAR agonistic activity of natural and xenobiotic compounds determined using in vitro bioassay systems and present recent field research showing the occurrence of RAR agonist contamination in the aquatic environment in North America, China and Japan. Environmental pollution by RAR agonists is a new endocrine disruption issue discovered very recently, and relevant knowledge is very limited. Further research will be required to obtain accurate information to assess the possible risks of RAR agonists in the environment.

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To analyze the quality of clinical trials in Japan for new applications of pharmaceuticals, compliance with the Good Clinical Practice (GCP) inspection was studied using Review Reports for approvals from fiscal year (FY)1999 to FY2008. Guidelines for GCP in Japan were harmonized with those of other countries at the International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH). Both to protect human rights, safety and welfare and to perform clinical trials scientifically and ethically, ensuring conformity with GCP is necessary when evaluating the safety and efficacy of the clinical data in common technical documents (CTD). In the conformity audit service of the Office of Conformity Audit of Pharmaceuticals and Medical Devices Agency (PMDA), the conformity of the studies and the documents between application materials of CTD attached to application forms for approval and case report forms (CRFs) is reviewed by document-based conformity inspection, and the conformity between medical records and CRFs is reviewed by on-site GCP inspection including oversea inspection. The GCP inspection includes both the on-site GCP inspection and the document-based conformity inspection. The importance of the GCP inspection by the Office of Conformity Audit to protect human rights, safety and welfare is summarized in this study. In conclusion, GCP inspection is conducted in accordance with the latest GCP, and the quality of clinical trials in Japan meets the Review Process by PMDA for marketing authorization. I hope that the GCP inspection protects human rights and improves the GCP conformity of clinical trials in Japan.

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A meta-analysis was performed on the reported literature regarding followings. First, values of the Michaelis-Menten constants (K_m), maximal velocities (V_max), and intrinsic clearance (V_max/K_m) and the metabolic activities mediated by human cytochrome P450 3A4 and/or 3A5; second, inhibition constants (K_i); and third, maximum inactivation rate constants (k_inact) to establish the contribution of P450 3A5 to drug metabolism. At least 120 of the 127 metabolic reactions investigated (>94%) were catalyzed by P450 3A4 and by P450 3A5. In the 73 metabolic reactions for which data were available, the mean P450 3A5/P450 3A4 ratios of K_m, V_max, and V_max/K_m values were 1.93, 1.25, and 1.20, respectively, but the median ratios were 1.17, 0.64, and 0.56, respectively. In 14-18% of the metabolic reactions, the V_max and V_max/K_m values for P450 3A5 were more than twice those for P450 3A4. The K_i values for P450 3A5 were on average approximately 5 times those for P450 3A4. Five of 13 mechanism-based inhibitors of P450 3A4 (38%) did not exhibit similar mechanism-based inhibition of P450 3A5. These collective findings give insight into the contribution of polymorphic P450 3A5 to drug metabolism and adverse drug interactions.

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To improve phytoremediation efficiency of polycyclic aromatic hydrocarbons (PAHs), pot experiment was conducted to introduce arbuscular mycorrhizal fungi, aromatic hyrocarbon degrading bacteria (ARDB), and rhamnolipids into phytoremediation system. Alfalfa biomasses, the number of heterotrophs and ARDB, dehydrogenase activity, polyphenol oxidase activity and residual PAHs concentration were determined after 90 days of alfalfa growth. The results indicated that the average removal efficiency of total PAHs by multi-technique phytoremediation system reached to 60.48%, which was 251.83% greater than that of phytoremediation itself (17.19%). Importantly, the multi-process system was capable of removing most of the high molecular weight PAHs (HMW-PAHs) from soil, the highest average removal percentage of HMW-PAHs, such as fluoranthene, pyrene and benzo[a]pyrene were 89.39%, 88.36% and 92.31%, respectively. A sharp increase in the size of the heterotrophic and aromatic hyrocarbon degrading microbial populations was observed, which resulted in increase of soil dehydrogenase and polyphenol oxidase activities. The key elements for successful phytoremediation were the use of biosurfactant that increase bioavaliable of PAHs in soil, and inoculation of microorganisms (arbuscular mycorrhizal fungi and ARDB) that accelerate plant growth and increase PAHs removal from heavily contaminated soils. The synergistic use of these approaches resulted in rapid and massive biomass accumulation of plant tissue in contaminated soil, putative providing more active metabolic process, and led to more rapid and more complete removal of PAHs.

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The effects of acute and subchronic administration of dimethoate on γ-aminobutyric (GABA) concentration and receptor characteristics in rat cerebral cortices were investigated. After a single (acute exposure) or repeated administration of dimethoate, rat cerebral cortex was found to inhibit acetylcholinesterase (AChE) activity in a dose-dependent manner. No significant alteration in the concentration of GABA or the numbers of GABA_A receptor was noted in cortices of rats after acute exposure to dimethoate except the affinities of the receptor was found elevated significantly following the acute administration. But the GABA concentrations were significantly reduced in the 10 and 20 mg/kg groups after the subchronic dimethoate administration. No difference was found statistically in the GABA_A receptor binding in cortices after the subchronic administration of dimethoate. But the K_d values were significant decreased reflecting an elevated affinity of receptors in the three dimethoate groups as compared with that of control follow subchronic administration. It is suggested that the GABAergic system is involved in the intoxication of the dimethoate intoxication which is probably to counteract the enhanced cholinergic activity induced by dimethoate.

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This experiment characterizes the time-dependent changes of phospholipids of liver microsomes, plasma, and triglycerides of adipose tissue when olive oil is substituted for soybean oil in the American Institute of Nutrition 93 Growth (AIN 93G) diet. After 2 weeks of acclimation with 7% soybean oil diet, 108 male Sprague-Dawley rats were randomly assigned to be fed diets with either 7% or 15% soybean oil or olive oil. Fatty acids of adipose, blood plasma, and liver microsomes were analyzed every four days for 4 weeks by gas chromatography. After 6 weeks of feeding, no differences in body weight or body composition were observed. The most profound changes occurred in the proportion of linoleic acid to oleic acid in the three tissues. The feeding regimens increased the ratio of oleic to linoleic acids by 6- to 14-fold in olive oil groups compared with soybean oil groups. The level of arachidonic acid declined in olive oil groups. In contrast, levels of n-3 series long chain fatty acids, eicosapentaenoic and docosahexaenoic acids, were higher in olive oil groups. The peroxidizability index, a measure of unsaturation, declined significantly in groups fed olive oil compared to soybean oil. These data indicate that substantial remodeling in fatty acid composition continues until 18-carbon precursors in adipose depots match the dietary pattern. The rate of change appears to be governed by the fractional exchange rate of adipose tissue, which is limited by the rates of lipolysis and daily fatty acid oxidation.

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Formaldehyde is an industrial chemical used in the manufacture of building materials and household products, and is one of the major pollutants that cause “sick building syndrome.” Formaldehyde causes a wide range of toxic effects such as the formation of DNA-protein cross-links, activation of the immune system, and sensory irritation. In the present study, we investigated the effects of formaldehyde inhalation on protein levels in rat bronchoalveolar lavage fluid with a proteomics approach. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight mass spectroscopy, we identified aldo-keto reductase 1B10 as a possible biomarker for formaldehyde inhalation. This study may contribute to a better understanding of the mechanisms involved in the pathogenesis of formaldehyde exposure.

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The neuroprotective effects of Hericium erinaceum (H. erinaceum) were studied in mice subjected to middle cerebral artery (MCA) occlusion. Infarct volumes were markedly reduced in mice receiving 14 days of H. erinaceum (300 mg/kg) treatment prior to 4-hr MCA occlusion. Moreover, 14-day pre-ischemic H. erinaceum treatment significantly increased the levels of nerve growth factor (NGF) in both the cortex and striatum of mice subjected to 4-hr MCA occlusion. However, pre-ischemic H. erinaceum treatment had no effect on cerebral blood flow (CBF) in the cortex of mice subjected to MCA occlusion. Treatment with H. erinaceum for 1 day prior to MCA occlusion-induced ischemia had no effect on infarct volume or NGF level. These results suggest that 14 days of treatment with H. erinaceum prior to MCA occlusion protected against focal cerebral ischemia, by increasing NGF levels. This implies that H. erinaceum and its components could be useful for preventing cerebral infarction.

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Under immunocompromised conditions such as aging, cancer, diabetes, burns, and sepsis, external agents may be useful for upregulation of the immune system to prevent infection. Dietary products have the advantage of being safe and easy to take. An extract of red bell pepper (Capsicum annuum L.) flesh markedly enhanced immunoglobulin M (IgM) production by murine B cells and their proliferation. The effect of the extract on IgM production was not abrogated by treatment with polymyxin B and was also observed in spleen cells of lipopolysaccharide-unresponsive C3H/HeJ mice. Treatment of B cells with the extract resulted in an increase in the number of IgM-secreting cells and cluster of differentiation (CD)138-positive cells. The IgM production-enhancing activity was resistant to trypsin treatment but was heat-labile. The activity was eluted in a peak with a molecular weight of 6000 on gel filtration. These results demonstrated that the extract of red bell pepper enhanced IgM production in B cells and suggest that the active substance(s) in the extract is a non-proteinous heat-labile macromolecule.

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We examined pharmacokinetic (PK) and pharmacodynamic (PD) interactions between coenzyme Q₁₀ (CoQ₁₀) and nifedipine (NFP), which is a popular medicine for treating hypertension, and elucidated possible mechanisms for the interaction between CoQ₁₀ and NFP in rats. The mean plasma concentrations of NFP in rats after the oral administration of NFP (1 mg/kg) with CoQ₁₀ (75 mg/kg) were increased over the study period and the area under the plasma concentration-time curve (AUC), showed a 1.47-fold increase compared with that of the control. Rats that received NFP with CoQ₁₀ showed a continuous decrease in the mean blood pressure over the study period compared with the control. There were no significant changes in the PK parameters of NFP after intravenous administration (1 mg/kg) between with and without oral CoQ₁₀ pretreatment, and also no significant changes in the intestinal excretion of rhodamine 123 (Rho123) or NFP between with and without CoQ₁₀ were found. In contrast, the portal plasma concentration of NFP after intra loop administration in the presence of CoQ₁₀ (75 mg/kg) showed a 1.6-fold increase in the AUC value compared with that of the control. As for physicochemical properties, the partition coefficient of NFP showed a marked increase in the presence of CoQ₁₀ over 10 mg/ml in the organic phase (n-hexane). From on an analysis of the absorbance spectrum, CoQ₁₀ showed a shift towards a longer wavelength in hydrophobic environments with NFP, suggesting that CoQ₁₀ reacts with NFP to form a charge-transfer complex due to a pi-cloud between them. In conclusion, it was found that CoQ₁₀ increases the oral bioavailability of NFP and that this interaction between NFP and CoQ₁₀ is not caused by metabolism via cycochrome P450 (CYP) 3A in the liver or intestine or by the inhibition of P-glycoprotein function, by the physicochemical interaction between them. Therefore, the solubility of NFP in a hydrophobic environment could be enhanced by forming a charge-transfer complex with CoQ₁₀, and it is considered that NFP deviating from a charge-transfer complex may migrate to the blood circulation from the intestinal tract. This mechanism of interaction is considered a new type of drug-supplement interaction.

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Waterborne diseases were globally occurred, and many people were suffered from and often killed by them. In order to prevent outbreaks of waterborne diseases, rapid detection of pathogenic microbes in aquatic environment is the important strategy in addition to the construction of water supply and vaccination. The 16S ribosomal RNA (rRNA) gene is often used as a target gene for bacterial detection using hybridization techniques. In this study, we aimed to design the oligonucleotide probes that could be used for the detection of waterborne bacteria with hybridization techniques because design of specific probes is important to assure for the precise detection of target bacteria. We then evaluated the specificities of designed probes by using an oligonucleotide microarray. In conclusion, we confirmed that seven designed oligonucleotide probes were suitable for the specific detection of waterborne bacteria. These probes appear to be used for 16S rRNA targeted hybridization techniques such as fluorescence in situ hybridization (FISH) and oligonucleotide microarray.

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The demethylation of methylmercury (MeHg) was investigated in human neuroblastoma, glioblastoma and liver cells. In the three cell lines, MeHg uptake reached a plateau within 24hr after MeHg exposure while the cellular inorganic Hg levels increased gradually up to 72hr. Methylviologen, a superoxide anion (O^-₂) generator, was found to be an effective enhancer of demethylation with only a minor effect on lipid peroxidation in all three cases. Fe(II), a hydroxyl radical (OH·) enhancer, showed little effect on the reaction in the presence of methylviologen, although lipid peroxidation levels were increased significantly. Furthermore, mannitol, an OH· scavenger, had no effect on inorganic Hg production. These results indicate that MeHg can be converted to inorganic Hg and that O^-₂ might predominantly participate in the demethylation reaction in the cells.

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A compact sampler consisting of a three-stage cascade impactor and a holder for polyurethane form (PUF) plugs was designed for the simultaneous collection of atmospheric polycyclic aromatic hydrocarbons (PAHs) in fine particles and the gaseous phase. To evaluate its collection efficiency, air was passed through a quartz-fiber filter (QFF) spiked with 28 authentic PAHs and then through cleaned PUF plugs and backup filters for 24hr in the dark at a constant room temperature (20 or 35°C). PAHs retained on the QFF and those trapped within PUF plugs and backup filters were separately determined. We observed no obvious difference in recoveries between 20 and 35°C except for benzo[a]anthracene (BaA) and triphenylene+chrysene. Most of the PAHs with low molecular weight (166-202) vaporised from the QFF and were trapped in the PUF plugs and backup filters at recoveries of 42-108%, while those with high molecular weight (≥252) were largely retained on the QFF (recoveries of 75-114%). BaA and triphenylene+chrysene (molecular weight=228) were largely retained on the QFF at 20°C (recoveries of ≥84%), but at 35°C the recovery values decreased to levels similar to those trapped with PUF plugs and backup filters (recoveries of 40-56%). The proposed sampler was applied in an investigation of ambient PAHs at a roadside site in a heavy-traffic area in Osaka, Japan, during August 2006 and February 2007.

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D-2-Amino-4-(2-aminophenyl)-4-oxobutanoic acid (D-kynurenine) was used to assay D-amino acid oxidase (DAAO, EC 1.4.3.3) activity. D-Kynurenine is enzymatically converted by DAAO to 4-hydroxyquinoline-2-carboxylic acid (kynurenic acid), which emits fluorescence at 398 nm (excitation wavelength 251 nm) in the presence of zinc ions. Using D-kynurenine as a substrate, fluorescence intensity originating from kynurenic acid can be used to assess DAAO activity. Under enzymatic reaction at pH 8.5 (37°C), the K_m and V_max of D-kynurenine were 148 μM and 5.53 μmol/min per mg, respectively. Inhibition of DAAO by a commercial DAAO inhibitor was clearly observed in this assay.

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The purpose of this study was to elucidate the effects of a main pungent component of wasabi, allyl isothiocyanate (AITC), on the number of lymphocytes, T-lymphocyte, B-lymphocyte and natural killer (NK) cells and plasma corticosterone concentrations in rats. AITC was given as either single dosage [20 mg/kg body weight per day; subcutaneous (s.c.) and oral] or as a daily dosage (10 mg and 20 mg/kg body weight per day; s.c.) for 4 days for the hourly and daily assessment of changes in the numbers of lymphocytes, respectively. A single s.c. injection or oral administration of AITC significantly reduced the number of lymphocytes at 4 hr to approximately 0.68 times, indicating that decreased effects of AITC on the number of lymphocytes are independent on the administration route. Administration of AITC for 4 days reduced dose-dependently the number of lymphocytes, and significantly reduced the number of T-lymphocyte and B-lymphocyte to 0.79 and 0.60 times, respectively. However, the number of NK cells did not change by AITC. Administration of AITC increased plasma corticosterone concentrations at 4 day of post s.c. injection to 5.4-6.0 times. These results suggest that AITC-mediated immunosuppresion is at least in part attributable to changes in the number and distribution of lymphocyte and its subsets.

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We previously reported that a decrease in the melanin content of mouse melanoma cells (B16 cells) treated with δ-tocotrienol was the result of a decrease in the level of tyrosinase activity and protein. Use of δ-tocotrienol as a whitening agent, may therefore have side effects. In the present study, we examined whether δ-tocotrienol caused side effects (the release of lysosomes from and a decrease in the cholesterol content of cells). We also examined the release of melanosomes (lysosome-related organella). Neither of lysosomes nor melanosomes were released from cells treated with δ-tocotrienol, since β-glucuronidase (melanosomal and lysosomal enzyme) activity, melanin content (melanosomal marker), and tyrosinase (melanosomal enzyme) activity did not increase in the cell culture medium. Although mevalonate pyrophosphate decarboxylase (MPD; an enzyme of cholesterol biosynthesis) was significantly reduced in the cells treated with δ-tocotrienol, cholesterol content was not. Thus, δ-tocotrienol might be useful as a therapeutic or preventive drug for hyperpigmentation and as a component of whitening and/or lightening cosmetics not causing severe side effect (reduction of cholesterol content and release of lysosomes/melanosomes), although δ-tocotrienol cause a decrease of MPD.

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