One-year monthly monitoring of Torque teno virus (TTV) in wastewater treatment plants in Japan

Torque teno virus (TTV) is a novel hepatitis virus which is considered to be transmitted by the fecal-oral route. Wastewater samples were collected monthly from eight wastewater treatment plants in Japan for 1 year, from July 2003 to June 2004, and tested for the presence of TTV by TaqMan PCR. TTV was detected in 97% (93/96) of influent samples, implying that TTV is epidemic in Japan. TTV was also isolated in 18% (17/96) of secondary effluent samples before chlorination and in 24% (23/95) of final effluent samples after chlorination. There was no significant difference between the concentration of total coliform in TTV-positive final effluents and that in TTV-negative final effluents, which indicates that total coliform cannot be used as an indicator of TTV. No TTV was detected in 24 effluents for reuse from two wastewater treatment plants using sand filtration and ozonation.     

Changes in dietary bioaccumulation of tributyltin chloride (TBTCl) in red sea bream (Pagrus major) with the concentration in feed

The effect of the concentration of tributyltin (TBT) in feed on the dietary bioaccumulation of tributyltin chloride (TBTCl) was studied in an 8-week uptake experiment and a 4-week elimination experiment using red sea bream (Pagrus major). The biomagnification factor (BMF) and the assimilation efficiency (AE) decreased from 0.30 to 0.15 and from 13% to 5.9%, respectively, as the TBT concentration in feed increased from 1.3 to 20 microg/g. The elimination rate constant (k(2)) was independent of the TBT concentration in the fish. Laboratory measurements of the BMF and AE of TBTCl underestimate actual field values if highly contaminated feed is used. Judging from the BMF and AE, the risk of the bioaccumulation of TBTCl through the food chain might be smaller than that of polychlorinated biphenyls.     

Thermal properties of solution flow-induced PVA crystals

Poly(vinyl alcohol) was crystallized from its aqueous solution under a steady-state flow with different conditions. Using a differential scanning calorimeter (DSC), the thermal properties of PVA precipitates obtained by the flow-induced crystallization were measured, showing a single melting peak in the DSC curve. The melting temperature of PVA crystallized depended on the rate of stirring, crystallization temperature, concentration of PVA, yield of precipitates, and morphology of the crystals. Particularly, there was a closer relationship between the melting temperature and the yield of precipitates, i.e., it was through the effect on the yield of precipitates that crystallization conditions influenced the melting temperature. Generally, with certain conditions, the higher the yield of precipitates, the lower the melting temperature. Moreover, using electron microscopy, it was observed that there were some structural differences between the inner and outer sides of a PVA crystal mat round stirrer and between film-shaped and block-shaped crystals, leading to different melting temperatures. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1337–1344, 1997     

Suppression of Bone Necrosis around Tooth Extraction Socket in a MRONJ-like Mouse Model by E-rhBMP-2 Containing Artificial Bone Graft Administration

Medication-related osteonecrosis of the jaw (MRONJ) is related to impaired bone healing conditions in the maxillomandibular bone region as a complication of bisphosphonate intake. Although there are several hypotheses for the onset of MRONJ symptoms, one of the possible causes is the inhibition of bone turnover and blood supply leading to bone necrosis. The optimal treatment strategy for MRONJ has not been established either. BMP-2, a member of the TGF-β superfamily, is well known for regulating bone remodeling and homeostasis prenatally and postnatally. Therefore, the objectives of this study were to evaluate whether cyclophosphamide/zoledronate (CY/ZA) induces necrosis of the bone surrounding the tooth extraction socket, and to examine the therapeutic potential of BMP-2 in combination with the hard osteoinductive biomaterial, β-tricalcium phosphate (β-TCP), in the prevention and treatment of alveolar bone loss around the tooth extraction socket in MRONJ-like mice models. First, CY/ZA was intraperitoneally administered for three weeks, and alveolar bone necrosis was evaluated before and after tooth extraction. Next, the effect of BMP-2/β-TCP was investigated in both MRONJ-like prevention and treatment models. In the prevention model, CY/ZA was continuously administered for four weeks after BMP-2/β-TCP transplantation. In the treatment model, CY/ZA administration was suspended after transplantation of BMP-2/β-TCP. The results showed that CY/ZA induced a significant decrease in the number of empty lacunae, a sign of bone necrosis, in the alveolar bone around the tooth extraction socket after tooth extraction. Histological analysis showed a significant decrease in the necrotic alveolar bone around tooth extraction sockets in the BMP-2/β-TCP transplantation group compared to the non-transplanted control group in both MRONJ-like prevention and treatment models. However, bone mineral density, determined by micro-CT analysis, was significantly higher in the BMP-2/β-TCP transplanted group than in the control group in the prevention model only. These results clarified that alveolar bone necrosis around tooth extraction sockets can be induced after surgical intervention under CY/ZA administration. In addition, transplantation of BMP-2/β-TCP reduced the necrotic alveolar bone around the tooth extraction socket. Therefore, a combination of BMP-2/β-TCP could be an alternative approach for both prevention and treatment of MRONJ-like symptoms.     

Real-time investigation of crystallization in poly(vinylidene fluoride)-based nano-composites probed by infrared spectroscopy

Via time-resolved Fourier transform infrared spectroscopy (FTIR), we examined the real-time investigation of the conformational changes of poly(vinylidene fluoride) (PVDF) chain segment during crystallization of neat PVDF and the corresponding nano-composites having intercalated structure. It was shown that in the following crystallization processes the crystal growth was virtually the same in both nano-composites and neat PVDF. We have examined an annealing at an infinitely long time at 200 °C (∼20 min) to erase the thermal history in the nano-composites. The dispersed titanate nano-filler particles exhibited strong contribution to enhance the heterogeneous nucleation for the formation of both γ- and β-phase crystals.     

Monitoring of acrylamide concentrations in potato chips in Japan between 2006 and 2010

Acrylamide levels in commercially available potato chips in Japan were monitored between August 2006 and June 2010 using the xanthydrol derivative gas chromatography-mass spectrometry (GC-MS) method. Seasonal and annual changes in acrylamide concentrations were determined. Nationwide bimonthly sampling of potato chips was carried out using a four-level design, and seasonal variations were detected in which the minimum acrylamide concentration was observed in August, and the maximum between February and June. Seasonal variations became less apparent after August 2008 as a result of annual effects and/or mitigation measures taken by the potato chip producers. Sampling uncertainties were separated into time-to-time, city-to-city, and lot-to-lot variation, and the largest variation was shown to be lot-to-lot including bag-to-bag.     

A method for the determination of acrylamide in a broad variety of processed foods by GC-MS using xanthydrol derivatization

A novel GC-MS method was developed for the determination of acrylamide, which is applicable to a variety of processed foods, including potato snacks, corn snacks, biscuits, instant noodles, coffee, soy sauces and miso (fermented soy bean paste). The method involves the derivatization of acrylamide with xanthydrol instead of a bromine compound. Isotopically labelled acrylamide (d?-acrylamide) was used as the internal standard. The aqueous extract from samples was purified using Sep-Pak? C?? and Sep-Pak? AC-2 columns. For amino acid-rich samples, such as miso or soy sauce, an Extrelut? column was used for purification or extraction. After reaction with xanthydrol, the resultant N-xanthyl acrylamide was determined by GC-MS. The method was validated for various food matrices and showed good linearity, precision and trueness. The limit of detection and limit of quantification ranged 0.5-5 and 5-20?μg?kg?1), respectively. The developed method was applied as an exploratory survey of acrylamide in Japanese foods and the method was shown to be applicable for all samples tested.     

Effect of Risk Information Exposure on Consumers’ Responses to Foods with Insect Contamination

This study explores the impact that scientific information about insect contamination of food has on consumer perceptions. Participants (n = 320, Japanese consumers) were randomly assigned to 1 of 8 information‐type conditions: (1) information about insect type, (2) information about contamination processes, (3) information about the safety of contaminated food, (4, 5, 6) combinations of 2 of (1), (2), and (3) above, (7) all information, and (8) no‐information, and asked to rate their valuation, behavioral intention, and attitude toward food with insect contamination. Results demonstrated that some combinations of scientific information that include the safety of the contaminated food are effective to reduce consumers’ compulsive rejection of insect contamination in food, whereas the single presentation of information about insect type increases consumers’ explicit rejection of both the contaminated product and the manufacturer. These findings have implications for the coordination of risk communication strategies.     

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.     

Bacterial reverse mutation test and micronucleus test of fucoxanthin oil from microalgae

Fucoxanthin-containing oil extracted from microalga, Chaetoseros sp., was subjected to genotoxicity studies, the bacterial reverse mutation test and the micronucleus test in mice. The number of revertant colonies in fucoxanthin oil-treated plates of all strains tested was less than twice the number of colonies in the negative control, regardless of the presence of the metabolic activator in the bacterial reverse mutation test. In the micronucleus test, 500, 1,000, 2,000 mg/kg body weight of fucoxanthin oil was administered orally to mice. There was no significant increase in micronucleus frequency in bone marrow cells. These results suggest that fucoxanthin oil does not exhibit genotoxicity.