Examining the reliability and validity of a self-regulated learning strategy scale for undergraduate nursing students and effective factors of self-regulated learning strategies.

BACKGROUND: Self-regulated learning in higher education has increasingly attracted attention in recent years. This study involved a survey of nursing students using an originally developed tool called the Self-regulated Learning Strategy Scale for Undergraduate Nursing Students (SRLSS-NS). OBJECTIVES: We aimed to elucidate factors relating to the promotion of self-regulated learning while confirming the reliability and validity of the novel scale. DESIGN: A cross-sectional survey design was adopted. SETTING: School of Health Science, Faculty of Medicine. PARTICIPANTS: Participants included first- to fourth-year undergraduate nursing students. METHODS: Descriptive statistics were used to ascertain participant characteristics. We confirmed the criterion-related validity of the survey through exploratory factor analysis and Pearson's product-moment coefficient with external criteria. Reliability was calculated using Cronbach's α coefficient. To examine stability, we confirmed the correlation between the first and second surveys. Multiple regression analysis was performed using the SRLSS-NS score as the objective variable and basic attributes/individual factors, learning-related factors, and cognitive factors as explanatory variables. The statistical significance level was defined as 5 %. RESULTS: The scale consisted of 12 items related to three factors-construct validity, internal consistency, and stability-which were confirmed. Regarding factors related to the SRLS of undergraduate nursing students, the SRLSS-NS score was greater for items such as, "I feel that university education gives me confidence in learning" (ß = 0.255, p < 0.001), "I like/find interest in things I am learning" (ß = 0.228, p < 0.001), "I feel that university education teaches me how to learn" (ß = 0.198, p = 0.003), and "Self-esteem as a professional" (ß = 0.143, p = 0.023). CONCLUSION: As more efforts are made to improve undergraduate nursing students' SRLS, the importance of education for increasing confidence, promoting intrinsic motivation, teaching learning methods, and fostering occupational identity is emphasized.

IFITM1 enhances nonenveloped viral RNA replication by facilitating cholesterol transport to the Golgi.

Aichi virus (AiV), a small non-enveloped RNA virus, hijacks the endoplasmic reticulum (ER)-Golgi cholesterol transport machinery to form cholesterol-rich replication sites originating from Golgi membranes. Interferon-induced transmembrane proteins (IFITMs) are antiviral restriction factors, whose involvement in intracellular cholesterol transport is suggested. Here, we describe the roles of IFITM1 in cholesterol transport that affect AiV RNA replication. IFITM1 stimulated AiV RNA replication and its knockdown significantly reduced the replication. In replicon RNA-transfected or infected cells, endogenous IFITM1 localized to the viral RNA replication sites. Further, IFITM1 interacted with viral proteins and host Golgi proteins, ACBD3, PI4KB, OSBP, which constitute the replication sites. When overexpressed, IFITM1 localized to the Golgi as well as endosomes, and this phenotype was also observed for endogenous IFITM1 early in AiV RNA replication, leading to the distribution of cholesterol at the Golgi-derived replication sites. The pharmacological inhibition of ER-Golgi cholesterol transport or endosomal cholesterol export impaired AiV RNA replication and cholesterol accumulation at the replication sites. Such defects were corrected by expression of IFITM1. Overexpressed IFITM1 facilitated late endosome-Golgi cholesterol transport without any viral proteins. In summary, we propose a model in which IFITM1 enhances cholesterol transport to the Golgi to accumulate cholesterol at Golgi-derived replication sites, providing a novel mechanism by which IFITM1 enables efficient genome replication of non-enveloped RNA virus.

Research on Cancer Screening Promotion and Employment Support for Employees with Cancer at Business Establishments.

Background: Increasing cancer screening rates among working-age populations and providing employment support for employees with cancer are issues that need to be addressed in Japan. Therefore, this study aimed to clarify the situation regarding cancer screening promotion and employment support for employees with cancer at business establishments and the support they seek from medical professionals regarding these issues. Methods: This survey covered 1,058 business establishments and included the following items: attributes of the business establishments, cancer screening rate, support for employees to promote cancer screening, support sought by business establishments from medical professionals to promote cancer screening, presence of employees with cancer, support programs for employees with cancer, awareness of the resources available for employment support for employees with cancer, difficulties in supporting employees with cancer in the workplace, and support sought by business establishments from medical professionals in providing employment support for employees with cancer. Data analysis was primarily conducted using summary statistics. Results: This study included 153 establishments. The median cancer screening rate ranged from 50.00 to 99.15. Employee support for promoting cancer screening ranged from approximately 30% to 40% for "ensuring time for screening" and from 20% to 30% for "providing full subsidies for cancer screening cost." The median screening rate for breast and cervical cancers was 50.00, and support for promoting screening was less than 30% for each. Business establishments sought support from medical professionals regarding cancer and study sessions on cancer prevention to promote cancer screening. Regarding support systems for employees with cancer, 49.7% of the establishments offered sickness benefits, and 42.5% offered paid leave on an hourly basis. Less than 10% were aware of the websites provided by public organizations regarding employment support for patients with cancer. Approximately 50% of the establishments reported difficulties regarding treatment policies and duration uncertainties. Conclusion: Business establishments sought the provision of relevant knowledge and specific information to increase cancer screening rates and provide employment support for employees with cancer. Furthermore, this study suggests that employees with cancer need to manage the information they provide their establishments.

Association between the perspective of adult inpatients with digestive cancer regarding the nursing service and their quality of recovery on postoperative day 3.

Although qualitative research that focuses on inpatients' experience immediately after surgery has continued to elucidate the efficacy of the nursing service for postoperative recovery, there has been little quantitative research. Our aim was to quantitatively clarify the association between inpatients' perception of the nursing service and the quality of postoperative recovery. Seventy-one digestive cancer patients who underwent surgery were recruited. Participants completed two self-administered questionnaires, including the Japanese version of the 40-item postoperative Quality of Recovery scale (QoR-40J) and the Nursing Service Quality Scale for Japan (NURSERV-J) which has 22 items and five dimensions (tangibles, reliability, responsiveness, assurance, and empathy) on postoperative day 3. There were significant positive associations between the global scores of the NURSERV-J and the QoR-40J. The global score of the QoR-40J was compared between patients who gave full marks for each dimension of the NURSERV-J (the entirely satisfied group) and those who did not (the not entirely satisfied group). The entirely satisfied groups regarding tangibles, reliability and responsiveness had a significantly higher global score for the QoR-40J than the respective not entirely satisfied groups. Adjusted for age, gender, operative procedure, and duration of surgery, the entirely satisfied groups regarding tangibles and responsiveness had a significant higher global score for the QoR-40J than the respective not entirely satisfied groups. Patients who perceived that they had received a nursing service of high quality were likely to attain a high quality of postoperative recovery. Nursing services related to tangibles, reliability, and responsiveness especially contributed to postoperative recovery.

Model of OSBP-Mediated Cholesterol Supply to Aichi Virus RNA Replication Sites Involving Protein-Protein Interactions among Viral Proteins, ACBD3, OSBP, VAP-A/B, and SAC1.

Positive-strand RNA viruses, including picornaviruses, utilize cellular machinery for genome replication. Previously, we reported that each of the 2B, 2BC, 2C, 3A, and 3AB proteins of Aichi virus (AiV), a picornavirus, forms a complex with the Golgi apparatus protein ACBD3 and phosphatidylinositol 4-kinase IIIß (PI4KB) at viral RNA replication sites (replication organelles [ROs]), enhancing PI4KB-dependent phosphatidylinositol 4-phosphate (PI4P) production. Here, we demonstrate AiV hijacking of the cellular cholesterol transport system involving oxysterol-binding protein (OSBP), a PI4P-binding cholesterol transfer protein. AiV RNA replication was inhibited by silencing cellular proteins known to be components of this pathway, OSBP, the ER membrane proteins VAPA and VAPB (VAP-A/B), the PI4P-phosphatase SAC1, and PI-transfer protein ß. OSBP, VAP-A/B, and SAC1 were present at RNA replication sites. We also found various previously unknown interactions among the AiV proteins (2B, 2BC, 2C, 3A, and 3AB), ACBD3, OSBP, VAP-A/B, and SAC1, and the interactions were suggested to be involved in recruiting the component proteins to AiV ROs. Importantly, the OSBP-2B interaction enabled PI4P-independent recruitment of OSBP to AiV ROs, indicating preferential recruitment of OSBP among PI4P-binding proteins. Protein-protein interaction-based OSBP recruitment has not been reported for other picornaviruses. Cholesterol was accumulated at AiV ROs, and inhibition of OSBP-mediated cholesterol transfer impaired cholesterol accumulation and AiV RNA replication. Electron microscopy showed that AiV-induced vesicle-like structures were close to ER membranes. Altogether, we conclude that AiV directly recruits the cholesterol transport machinery through protein-protein interactions, resulting in formation of membrane contact sites between the ER and AiV ROs and cholesterol supply to the ROs.IMPORTANCE Positive-strand RNA viruses utilize host pathways to modulate the lipid composition of viral RNA replication sites for replication. Previously, we demonstrated that Aichi virus (AiV), a picornavirus, forms a complex comprising certain proteins of AiV, the Golgi apparatus protein ACBD3, and the lipid kinase PI4KB to synthesize PI4P lipid at the sites for AiV RNA replication. Here, we confirmed cholesterol accumulation at the AiV RNA replication sites, which are established by hijacking the host cholesterol transfer machinery mediated by a PI4P-binding cholesterol transfer protein, OSBP. We showed that the component proteins of the machinery, OSBP, VAP, SAC1, and PITPNB, are all essential host factors for AiV replication. Importantly, the machinery is directly recruited to the RNA replication sites through previously unknown interactions of VAP/OSBP/SAC1 with the AiV proteins and with ACBD3. Consequently, we propose a specific strategy employed by AiV to efficiently accumulate cholesterol at the RNA replication sites via protein-protein interactions.

A complex comprising phosphatidylinositol 4-kinase IIIß, ACBD3, and Aichi virus proteins enhances phosphatidylinositol 4-phosphate synthesis and is critical for formation of the viral replication complex.

UNLABELLED: Phosphatidylinositol 4-kinase IIIß (PI4KB) is a host factor required for the replication of certain picornavirus genomes. We previously showed that nonstructural proteins 2B, 2BC, 2C, 3A, and 3AB of Aichi virus (AiV), a picornavirus, interact with the Golgi protein, acyl-coenzyme A binding domain containing 3 (ACBD3), which interacts with PI4KB. These five viral proteins, ACBD3, PI4KB, and the PI4KB product phosphatidylinositol 4-phosphate (PI4P) colocalize to the AiV RNA replication sites (J. Sasaki et al., EMBO J. 31:754-766, 2012). We here examined the roles of these viral and cellular molecules in the formation of AiV replication complexes. Immunofluorescence microscopy revealed that treatment of AiV polyprotein-expressing cells with a small interfering RNA targeting ACBD3 abolished colocalization of the viral 2B, 2C, and 3A proteins with PI4KB. A PI4KB-specific inhibitor also prevented their colocalization. Virus RNA replication increased the level of cellular PI4P without affecting that of PI4KB, and individual expression of 2B, 2BC, 2C, 3A, or 3AB stimulated PI4P generation. These results suggest that the viral protein/ACBD3/PI4KB complex plays an important role in forming the functional replication complex by enhancing PI4P synthesis. Of the viral proteins, 3A and 3AB were shown to stimulate the in vitro kinase activity of PI4KB through forming a 3A or 3AB/ACBD3/PI4KB complex, whereas the ACBD3-mediated PI4KB activation by 2B and 2C remains to be demonstrated. IMPORTANCE: The phosphatidylinositol 4-kinase PI4KB is a host factor required for the replication of certain picornavirus genomes. Aichi virus, a picornavirus belonging to the genus Kobuvirus, forms a complex comprising one of the viral nonstructural proteins 2B, 2BC, 2C, 3A, and 3AB, the Golgi protein ACBD3, and PI4KB to synthesize PI4P at the sites for viral RNA replication. However, the roles of this protein complex in forming the replication complex are unknown. This study showed that virus RNA replication and individual viral proteins enhance the level of cellular PI4P, and suggested that the viral protein/ACBD3/PI4KB complex plays an important role in forming a functional replication complex. Thus, the present study provides a new example of modulation of cellular lipid metabolism by viruses to support the replication of their genomes.

1(OH) vitamin D3 supplementation improves the sensitivity of the immune-response during Peg-IFN/RBV therapy in chronic hepatitis C patients-case controlled trial.

OBJECTIVE: 1,25(OH)2 vitamin D3 can affect immune cells. However, the mechanism responsible for the favorable effects of 1(OH) vitamin D3, which becomes 1,25(OH)2 vitamin D3 in the liver, is not clear. The aim of this study is to analyze the immunological response of 1(OH) vitamin D3 supplementation in CH-C patients. DESIGN: Forty-two CH-C patients were treated with 1(OH) vitamin D3/Peg-IFNα/RBV. Forty-two case-matched controls were treated with Peg-IFNα/RBV. The expression of Interferon-stimulated genes (ISGs)-mRNA in the liver biopsy samples and JFH-1 replicating Huh-7 cells were quantified by real-time PCR. Ten kinds of cytokines in the plasma were quantified during treatment by using a suspension beads array. A trans-well co-culture system with peripheral blood mononuclear cells (PBMCs) and Huh-7 cells was used to analyze the effect of 1(OH) vitamin D3. The activities of the Th1 response were compared between subjects treated with 1(OH) vitamin D3/Peg-IFN/RBV and those treated with Peg-IFN/RBV therapy alone. RESULTS: 1(OH) vitamin D3/Peg-IFN/RBV treatment could induce rapid viral reduction, especially in IL28B T/T polymorphism. Several kinds of cytokines including IP-10 were significantly decreased after 4 weeks of 1(OH) vitamin D3 treatment (p<0.05). Th1 responses in the subjects treated with 1(OH) vitamin D3/Peg-IFN/RBV were significantly higher than those treated with Peg-IFN/RBV at 12 weeks after Peg-IFN/RBV therapy (p<0.05). The expression of ISGs in the patient's liver biopsy samples was significantly lower than in those treated without 1(OH) vitamin D3 (p<0.05). CONCLUSION: 1(OH) vitamin D3 could improve the sensitivity of Peg-IFN/RBV therapy on HCV-infected hepatocytes by reducing the IP-10 production from PBMCs and ISGs expression in the liver.

[Correlation of fat content and dioxins, total mercury and methyl mercury levels in tuna].

In this study, we analyzed the concentrations of mercury and dioxins in tuna with various fat contents (akami; the leaner meat, Chutoro; the belly area of the tuna along the side of the fish between the akami and the otoro. Otoro; the fattiest portion of the tuna) in wild and farmed bluefin tuna and farmed southern bluefin tuna. In the three kinds of tuna, average dioxins concentrations in Akami, chutoro and otoro were 1.7, 4.7 and 9.6 pg TEQ/g, respectively. The dioxins concentration in all three regions of tuna was in direct proportion to the fat content. In the farmed bluefin tuna, the dioxins concentration was almost the same as that of the wild tuna, but differed from that of the farmed southern bluefin tuna. Average total mercury concentration based on wet weight in akami was 0.42 µg/g, being higher than the values of 0.36 µg/g of chutoro and 0.31 µg/g of otoro, and in inverse proportion to the fat content. In all three regions, the total mercury concentration of the wild bluefin tuna was equal to that of the farmed tuna. The total mercury concentration in the latter was two to three times higher than that of the farmed southern bluefin tuna. If the Japanese intake is one fin of tuna (80 g) a day, the daily intake levels of dioxins and methyl mercury can be estimated as 0.48-37 pg TEQ/kg bw and 0.21-0.90 µg/kg bw, respectively.

[Analytical method of dodine in agricultural products by LC/MS].

A method for the determination of dodine in agricultural products was developed by using liquid chromatography-electrospray ionization mass spectrometry (LC/ESI-MS). Dodine was extracted with acetonitrile and then acetonitrile-water (7 : 3) from a sample, and re-extracted with ethyl acetate. The extract was cleaned up on a PSA cartridge column (500 mg), and dodine was analyzed by LC/MS. In the case of oil seeds and nuts, hexane/acetonitrile-hydrochloric acid partition was performed to remove lipids before re-extraction with ethyl acetate. In the case of samples that contained a lot of chlorophyll, the eluate of the PSA cartridge column was further cleaned up on a graphitized carbon cartridge column (500 mg). The calibration curve was linear from 0.0001-0.02 microg/mL of dodine. The recoveries of dodine from sixteen kinds of agricultural products fortified at 0.1 mg/kg were 80.3-100.0%, and their relative standard deviations were 0.3-6.4%. The limits of detection (S/N=3) were 0.0006 mg/kg.

Biosensor immunoassay for the screening of dioxin-like polychlorinated biphenyls in retail fish.

Dioxin-like polychlorinated biphenyls (DL-PCBs) often make up the majority of the toxic equivalent (TEQ) contribution of dioxins found in fish samples. For the purpose of making risk assessments, it is therefore important to develop screening methods for determining TEQ concentrations of DL-PCBs in retail fish. We have developed a rapid biosensor immunoassay (BIA) for DL-PCBs that uses a surface plasmon resonance sensor (Biacore 3000). The BIA is highly specific for 2,3',4,4',5-pentachlorobiphenyl (PCB 118) that is generally the most abundant DL-PCB isomer found in fish. The fish extracts were first cleaned up on a multilayer silica gel column followed by an alumina column, then subjected to the assay. The quantitative limit of the assay was 1 ng PCB 118 per gram of tested sample. Dilution and recovery tests using purified fish extracts suggested that the matrix effect was minimized in the assay by diluting the analyzed samples. The assay results for retail fish samples (n=7) agreed well with those obtained by an enzyme-linked immunoassay (ELISA) using the same monoclonal antibody: ELISA has been already validated for determining DL-PCBs in fish samples, so BIA performs well in this analysis. Finally, BIA results for the TEQ concentrations of DL-PCBs in retail fish samples (n=10) correlated well with those obtained by high-resolution gas chromatography coupled to high-resolution mass spectrometry (r=0.89). Our method is therefore useful for screening retail fish to determine the TEQ concentrations of DL-PCBs.

PCB 118 and Aryl Hydrocarbon Receptor Immunoassays for Screening Dioxins in Retail Fish.

The efficacy of a combination of two enzyme-linked immunosorbent assay (ELISA) kits was examined for screening the toxic equivalent (TEQ) concentrations of dioxins in retail fish. The coplanar PCB-EIA system, which is a competitive immunoassay specific for polychlorinated biphenyl (PCB) 118, was tested as a screening method for mono- ortho PCBs. The Ah immunoassay (Ah-I), which is an ELISA-based aryl hydrocarbon receptor binding assay, was analyzed for its screening ability for non- ortho PCBs, polychlorinated dibenzo- p-dioxins (PCDDs), and dibenzofurans (PCDFs). Dilution and recovery tests using purified fish extracts revealed no major interference of the matrix in the PCB-EIA and suggested that the matrix effect was minimized in the Ah-I. Finally, the results for the fish samples ( n = 20) showed a strong correlation between this method and high-resolution gas chromatography coupled to high-resolution mass spectrometry for the determination of the TEQ concentrations of mono- ortho PCBs ( r = 0.99) and non- ortho PCBs and PCDD/Fs ( r = 0.97). These data indicate that our method is suitable for screening retail fish to determine the TEQ concentrations of dioxins.

Determination of brominated flame retardants and brominated dioxins in fish collected from three regions of Japan.

The concentrations of brominated dioxins which are polybrominated dibenzo-p-dioxins/polybrominated dibenzofurans (PBDD/DFs) and mono-bromo polychlorinated dibenzo-p-dioxins/dibenzofurans, polybrominated diphenyl ethers (PBDEs) and tetrabromobisphenol A (TBBPA) were investigated in a total of 45 fish samples collected from three regions in Japan. In the brominated dioxins, 1,2,3,4,6,7,8-heptabromodibenzofuran (HpBDF) was the most abundant congener, and it was found in seven fish samples at 0.10-25.6 pg/g wet weight (ww). The highest concentration of 1,2,3,4,6,7,8-HpBDF was found in the pike eel. Regarding other congeners, 2,3,7,8-tetrabromodibenzo-p-dioxin was detected in the sea bream at 0.02 pg/g ww, and 2,3,7,8-tetrabromodibenzofuran was detected in the conger eel at 0.03 pg/g ww. 3-Bromo-2,7,8-trichlorodibenzofuran was detected in the Sardinella zunasi and the conger eel at 0.01 pg/g ww and 0.02 pg/g ww, respectively. Using toxic equivalency factors of chlorinated dioxins, we calculated the PBDD/DFs concentrations of these fish samples at 0.001-0.256 pg TEQ/g ww. PBDEs were detected in all of the fish samples. The concentrations of total PBDEs were 0.01-2.88 ng/g ww. The seerfish and the yellowtail containd PBDEs in high concentrations. The most dominant congener in most of the fish was 2,2',4,4'-tetrabromo diphenyl ether. TBBPA was detected in 29 fish samples at 0.01-0.11 ng/g ww. The mean level of TBBPA was about one-tenth or less of the total level of PBDEs. A good correlation was obtained between total PBDEs and fat content. On the other hand, no correlation was obtained between TBBPA and fat content. The daily intakes from fish were estimated to be 0.58 ng/kg body weight (bw)/day for total PBDEs, 0.03 ng/kg bw/day for TBBPA, and 0.01 pg TEQ/kg bw/day for brominated dioxins in the case assuming that the average bw of a Japanese adult person is 50 kg and that the average fish consumption is 82 g/day. For PBDEs, the provisionally calculated value was much less than the lowest observed adverse effect level value (1 mg/kg bw/day). For brominated dioxins, the daily intake was at a very low level compared with the Japanese daily intake of polychlorinated dioxins from fish. Even if the value of PBDD/DFs is added to the amount of chlorinated dioxin exposure, it was estimated that it is less than the tolerable daily intake (4 pg TEQ/kg bw/day) in Japan.

Influence of food polyphenols on aryl hydrocarbon receptor-signaling pathway estimated by in vitro bioassay.

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that mediates the toxic and biological actions of many aromatic environmental pollutants such as dioxins. We investigated AhR activation by some vegetable constituents, including flavonoids, tannins, and related polyphenols, using an AhR-based in vitro bioassay for dioxins. Among the compounds tested, marked AhR activation was exhibited by isoflavones such as daidzein, resveratrol (a stilbene) structure, some flavanones such as naringenin, and flavones such as baicalein. On the other hand, some flavones such as apigenin, flavonols such as quercetin, and anthraquinones such as emodin, showed notable inhibitory effects on the in vitro activation of AhR induced by the dioxin [2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)]. In addition, AhR-mediated interactions between AhR and some plant extracts, including those from vegetables, fruits, herbs, and teas, were tested by using the AhR-based bioassay. Of the samples tested, some leafy green vegetables, citrus fruits, and herbs that contain food polyphenolics showed AhR-based interactions at high concentrations. On the basis of these finding, we discuss the implications of polyphenols on the AhR-signaling pathway.

Dioxin concentrations in the edible parts of Japanese common squid and saury.

We examined the concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dioxin-like PCBs) in muscle and gut tissues from Japanese common squid and saury. These body parts are often eaten in Japan, so it is important to measure their dioxin concentrations and evaluate the risks to consumers. The toxic equivalent (TEQ) concentrations in the squid gut samples (1.0 to 14 pg-TEQ/g fresh weight, n=3) were 50-fold larger than those in the muscle tissues (0.020 to 0.22 pg-TEQ/g fresh weight, n = 3) taken from the same samples. By contrast, the TEQ concentrations in the saury gut samples (0.35 to 0.63 pg-TEQ/g fresh weight, n=3) were only 1.1- to 1.7-fold greater than those in the muscle tissues (0.33 to 0.37 pg-TEQ/g fresh weight, n= 3) from the same samples. The TEQ contents in the squid gut tissues ranged from 60 to 990 pg-TEQ/squid, accounting for about 95% of the total dioxin content of the edible parts of the samples. By contrast, the TEQ contents in the saury gut tissues ranged from 4.4 to 12 pg-TEQ/saury, accounting for less than 25% of the total dioxin content of the edible parts of the samples. These tissues showed comparable PCDD/PCDF-congener and dioxin-like PCB-isomer profiles in both species. The results indicate that squid gut tissues occasionally contain high levels of dioxins, and consumption of this foodstuff could potentially significantly increase the dietary intake of dioxins.

[Analytical method for methoprene in foods using HPLC].

We studied the determination of methoprene in foods by high-performance liquid chromatography (HPLC). The sample was extracted with acetonitrile and the extract was salted out by adding sodium chloride, allowing the acetonitrile layer to separate. The acetonitrile solution was washed with hexane saturated with acetonitrile, cleaned up on a Florisil column and determined by HPLC. The recovery of methoprene from spiked samples was 74.6-82.8%. In an evaluation of this method by 6 analytical laboratories, mean recoveries from spiked samples ranged from 79.4% to 84.6%. Repeatability relative standard deviation values were 2.3-8.8% and reproducibility relative standard deviation values were 8.8-23.6%. The detection limits were 0.001-0.02 microg/g and below the detection limit of the Notified Analytical Method.

Application of an ELISA for PCB 118 to the screening of dioxin-like PCBs in retail fish.

A commercially available enzyme-linked immunosorbent assay (ELISA) kit was evaluated for the determination of toxic equivalents (TEQs) of dioxin-like polychlorinated biphenyls (PCBs) in retail fish. The ELISA was highly specific for 2,3',4,4',5-pentachlorobiphenyl (PCB 118), which is generally the most abundant dioxin-like PCB isomer found in fish. The quantitative limit of the ELISA (using 3,3',4'-trichloro-4-methoxybiphenyl as a surrogate standard for PCB 118) was 10 ng ml(-1) (125 pg assay(-1)) in the standard curve, corresponding to 50 pg PCB 118 g(-1) in the tested sample. Good recoveries of PCB 118 (78.7-112.3%) were obtained for spiked purified fish extracts according to the ELISA. Good linearity was also obtained in dilution tests using purified fish extracts. No significant interference of the matrix was observed in the ELISA when this purification procedure was used. Recovery tests in which PCB 118 was added to fish samples also resulted in acceptable recoveries (60.2-82.3%) in the ELISA following purification. The ELISA results for fish samples correlated well with the TEQ concentrations of dioxin-like PCBs obtained by high-resolution gas chromatography/high-resolution mass spectrometry (r = 0.92, n = 26). These data indicate that the ELISA kit is suitable for screening retail fish for the TEQs of dioxin-like PCBs.

Effects of cooking on concentrations of polychlorinated dibenzo-p-dioxins and related compounds in fish and meat.

We investigated the cooking-induced changes in concentrations of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (PCBs) (dioxins) using mackerel and beef. The concentrations of dioxins (29 congeners) were determined by isomer specific analyses and were compared between uncooked and cooked samples. The cooking procedures examined in this study included grilling as a fillet, boiling as a fillet, and boiling as tsumire (small, hand-rolled balls) for mackerel and boiling as a slice, broiling as a slice, and broiling as a hamburger for beef. Three trials were carried out for each cooking method. Generally, concentrations of dioxins were reduced in every cooking trial. When nondetected congener concentrations were assumed to be half the limit of detection for mackerel, the maximum percentage reductions of total concentrations given as 2,3,7,8-tetraCDD equivalents (TEQ) were 31% in grilling as a slice, 14% in boiling as a slice, and 21% in boiling as tsumire under the conditions of this study. In contrast, for beef, the reductions were 42% in boiling as a slice, 42% in broiling as a slice, and 44% in broiling as a hamburger. These results suggest that ordinary cooking processes with heating undoubtedly reduce the dioxin content in animal products, and the reductions estimated should be considered when dioxin intake is evaluated using contamination data for individual food items.

Contamination levels of PCDDs, PCDFs and Co-PCBs in commercial baby foods in Japan.

To examine dioxin contamination in commercial baby foods in Japan, congener analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and coplanar polychlorinated biphenyls (Co-PCBs) were performed on 102 varieties of baby foods obtained from supermarkets in 2001-2002. The toxic equivalent quantity (TEQ) levels for dioxins in samples ranged from < 0.001 to 0.135 pg-TEQ/g wet weight when undetected or trace levels of congeners were taken as zero. Among 102 samples tested, 26 samples exceeded 0.010 pg-TEQ/g. The highest TEQ value was for "sardine, vegetables" (0.135 pg-TEQ/g), followed by "Japanese radish (daikon), sardine" (0.080 pg-TEQ/g). Thus, dioxins were detected at low levels in baby foods containing animal products such as fishes and/or dairy products.

Are transcription factors NF-kappaB and AP-1 involved in the ANG II-stimulated production of proinflammatory cytokines induced by LPS in dehydrated rats?

We recently reported an involvement of ANG II and the ANG II type 1 (AT1) receptor in the hepatic expression of IL-1beta induced in dehydrated rats by LPS. Here, we first confirmed that ANG II and AT1 receptors contribute to the LPS-induced increase in the splenic concentration of IL-1beta in dehydrated rats. We then investigated whether ANG II contributes to IL-1 production through a modulating effect on the activation of proinflammatory transcription factors (NF-kappaB and AP-1) that is induced in the dehydrated rat's liver and spleen by intravenous injection of LPS. Surprisingly, LPS markedly increased the hepatic activation of NF-kappaB, an effect that was significantly enhanced (rather than reduced) by pretreatment with an ANG-converting-enzyme (ACE) inhibitor or AT1-receptor antagonist. Furthermore, the same ACE inhibitor and AT1-receptor antagonist each increased the resting NF-kappaB activity in the liver and spleen, although they had no effect on the LPS-induced splenic expression of NF-kappaB. Both hepatic and splenic AP-1 expressions were enhanced by LPS. This response was significantly augmented by pretreatment with the AT1-receptor antagonist (but not with the ACE inhibitor) in the spleen, while in the liver, neither drug had any effect. These results suggest that the endogenous ANG II or AT1 receptor suppresses the activation of hepatic or splenic transcription factors in dehydrated rats given LPS. Our results seem not to support the idea that NF-kappaB and AP-1 play key roles in the ANG II-induced enhancement of the production of proinflammatory cytokines that is induced by LPS in dehydrated rats.

[Determination of isophorone in foods].

Isophorone (ISP) is used widely as a solvent of natural and synthetic resins, wax, printing ink, pesticides and paints. In this study, the level of ISP in various foods (93 samples) was analyzed. ISP was collected from samples by steam distillation after the addition of an internal standard, deuterium-labeled ISP, then extracted with dichloromethane, cleaned up on a silica gel column, and determined by GC/MS. ISP was barely detected in fish, meat and vegetable samples, but it was detected in rice, wheat, beans and their processed products, miso, soy sauce and fermented soybeans (natto). The maximum level was 8.9 ng/g in miso. The packaging materials of the foods contained little ISP, and so the source of ISP in the foods could not be clarified.