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MEASUREMENT OF AEROSOLS IN ENGINEERED NANOMATERIALS FACTORIES FOR RISK ASSESSMENT
YUJI FUJITANI,TAKAHIRO KOBAYASHI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2008 NANO Vol.3 No.4
In relation to potential health risks, there is little available information on exposure to aerosols containing nanometer-size particles in work environments in factories producing engineered nanomaterials. We measured the concentrations and size distributions of particles of nanometer-sized to coarse-sized particles in an engineered carbon nanomaterial factory and a titanium dioxide factory. In addition, particles were collected with a quartz fiber filter in the engineered carbon nanomaterial factory, and their morphology was examined by scanning electron microscopy and their carbon composition was examined with a carbon analyzer. In the carbon nanomaterial factory, the particle number increased to more than 105 cm-3 when a vacuum cleaner was used to clean the inside of the producing device, and the particle number increased for particles with a diameter of about 100 nm compared with the background. This is the only case an increase in particle numbers is observed during this measurement. The emitted particles appear to consist of agglomerates of carbon nanomaterial particles smaller than 100 nm. The major fraction was the EC3 fraction (EC: elemental carbon; combustion at 800°C in a 98:2 He/O2 atmosphere), which is a minor fraction in diesel engine particulate matter. This suggests that the combustion temperature can be used to differentiate atmospheric particulate matter from engineered carbon material. Personal sampling conducted in addition to stationary measurements in the titanium dioxide factory indicated that stationary measurements can be used to generate representative data on the basis of the particle number but not the particle mass.
Biochemical Properties of Two Lipoxygenases from Pleurotus ostreatus
Mio Kobayashi,Shunya Hayashi,Yuji Tasaki 한국버섯학회 2017 버섯 Vol.21 No.2
The characteristic aroma of mushrooms is one of their attractive elements as food materials. The major aroma compound in most mushrooms is 1-octen-3-ol. The biosynthesis of 1-octen-3-ol starts with the oxidation of linoleic acid by lipoxygenase (LOX). The resultant intermediate hydroperoxide is then cleaved by hydroperoxide lyase. LOX is a non-heme iron-containing dioxygenase widely found in plants, animals, fungi, and bacteria. It catalyzes the insertion of molecular oxygen into polyunsaturated fatty acids containing Z,Z-1,4-pentadiene moieties, such as linoleic acid, linolenic acid, and arachidonic acid, yielding the corresponding hydroperoxides. Two LOX genes, Polox1 and Polox2, have been isolated from P. ostreatus, which has higher LOX activity than other edible mushrooms. Polox1 and Polox2 were found to show different expression patterns during the development of the fruiting body. However, the biochemical properties of PoLOX1 and PoLOX2, encoded by Polox1 and Polox2, respectively, have been not fully elucidated. In this study, we engineered these two LOX genes of P. ostreatus into a heterologous host, Escherichia coli, and characterized the recombinant proteins. The coding regions of Polox1 and Polox2 were amplified by RT-PCR from the total RNA of P. ostreatus PC15 mycelia. The RT-PCR products were digested with appropriate restriction enzymes and ligated into an expression vector (pET-16b). The resultant plasmids were introduced into E. coli BL21 (DE3) via transformation. Polox1 and Polox2 were then expressed by induction at 15°C with 0.4 mM IPTG for 18 h. The cells were harvested by centrifugation and resuspended in 10 mM potassium phosphate buffer (pH 7.0). The cell suspension was sonicated and again centrifuged at 15,000 ×g for 20 min at 4 °C. The resultant cell-free extract was used for subsequent experiments. Recombinant PoLOX1 and PoLOX2 were confirmed by SDS-PAGE analysis of the cell-free extract. PoLOX1 and PoLOX2 were estimated to have molecular weights of approximately 76,000 Da and 78,000 Da, respectively. The LOX activity was determined with linoleic acid as a substrate by a spectrophotometric procedure based on the formation of conjugated dienes. To characterize the biochemical properties of PoLOX1 and PoLOX2, in vitro enzymatic assays were performed using the total cell protein from E. coli expressing the two Polox genes, with linoleic acid as a substrate. The optimum pH of recombinant PoLOX1 and PoLOX2 was 7.5 and 5.5, respectively; the optimum temperatures of recombinant PoLOX1 and PoLOX2 were 55 °C and 30 °C, respectively. Recombinant PoLOX1 and PoLOX2 were stable at pH 5.0-9.0 and 6.0-8.0, respectively; recombinant PoLOX1 and PoLOX2 were relatively stable below 50 °C and 40 °C, respectively. Thus, PoLOX1 had higher thermal and pH stability than PoLOX2. The calculated Km values of PoLOX1 and PoLOX2 were 121 μM and 249 μM, respectively. The calculated Vmax values of PoLOX1 and PoLOX2 were 17.2 μmol/mg・min and 17.5 μmol/mg・min, respectively. These results indicated that PoLOX1 had a higher affinity for linoleic acid than PoLOX2. Collectively, our findings suggested that there were some differences between the biochemical properties of PoLOX1 and PoLOX2.
( Hiroyuki Kan ),( Yuji Arai ),( Masashi Kobayashi ),( Shuji Nakagawa ),( Hiroaki Inoue ),( Manabu Hino ),( Shintaro Komaki ),( Kazuya Ikoma ),( Keiichiro Ueshima ),( Hiroyoshi Fujiwara ),( Toshikazu 대한슬관절학회 2017 대한슬관절학회지 Vol.29 No.1
Purpose: The fixed flexion view (FFV) of the knee is considered useful for evaluating the joint space when assessing the severity of osteoarthritis (OA) of the knee. To clarify the usefulness of FFV for evaluation of the joint space and severity of knee OA, this study evaluated changes in the joint space on the FFV and standing extended view (SEV) in patients with knee OA. Materials and Methods: The SEV and FFV images were acquired in 567 patients (1,102 knees) who visited the hospital with a chief complaint of knee joint pain. Medial joint space width (MJSW) and Kellgren-Lawrence (K-L) classification assessed using the SEV and FFV images were compared. Results: Mean MJSW was significantly smaller when assessed on the FFV than on the SEV (3.02±1.55 mm vs. 4.31±1.30 mm; p<0.001). The K-L grade was the same or higher on the FFV than on the SEV. Conclusions: The FFV is more useful than the SEV for evaluating the joint space in OA knees. Treatment strategies in patients with knee OA should be determined based on routinely acquired FFV images.
Akira Mitsuhashi,Yuji Habu,Tatsuya Kobayashi,Yoshimasa Kawarai,Hiroshi Ishikawa,Hirokazu Usui,Makio Shozu 대한부인종양학회 2019 Journal of Gynecologic Oncology Vol.30 No.6
Objective: The present study investigated long-term outcomes of medroxyprogesteroneacetate (MPA) plus metformin therapy in terms of control of atypical endometrial hyperplasia(AEH) and endometrial cancer (EC), and post-treatment conception. Methods: We retrospectively analyzed 63 patients (42 with EC; 21 with AEH) who underwentfertility-sparing management using MPA plus metformin. MPA (400 mg/day) and metformin(750–2,250 mg/day) were administered to achieve complete response (CR). Metformin wasadministered until conception, even after MPA discontinuation. Results: Of the total patients, 48 (76%) had a body mass index (BMI) ≥25 kg/m2 and 43 (68%)showed insulin resistance. Sixty-one patients (97%) achieved CR within 18 months. CR ratesat 6, 8–9, and 12 months were 60%, 84%, and 90%, respectively. During a median followupperiod of 57 months (range, 13–115 months), relapse occurred in 8 of 61 patients (13.1%)who had achieved CR. Relapse-free survival (RFS) in all patients at 5 years was 84.8%. Uponunivariate analysis, patients with BMI ≥25 kg/m2 had significantly better prognoses than didthose with BMI <25 kg/m2 (odds ratio=0.19; 95% confidence interval=0.05–0.66; p=0.009). Overall pregnancy and live birth rates per patient were 61% (19/31) and 45% (14/31), respectively. Conclusions: MPA plus metformin is efficacious in terms of RFS and post treatmentconception. Moreover, metformin may be more efficacious for patients with BMI ≥25 kg/m2.