Biomedical subjects

Takashi Otani

Publications and source records attributed to Takashi Otani.

7 recordsLinked to original sources

PubMed2006

Polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in rice plants: possible contaminated pathways.

Uptake of dioxins was confirmed in rice plants. We determined (i) dioxin concentrations and isomer profiles in leaf+stem samples of rice plants grown in three soils with different dioxin concentrations and isomer profiles and (ii) temporal changes in dioxin concentrations and isomer profiles in rice grown in a paddy field on which agricultural chemicals containing dioxin impurities had been used in previous years. Principal-component and chemical mass-balance analyses of the data showed that dioxin concentrations and isomer profiles in the rice grown in the different soils were similar, even though the dioxin concentrations and isomer profiles of the soils were different. However, the dioxin concentrations in the rice were influenced by dioxin levels in the atmospheric gas phase. Changes in dioxin levels during the growing period of the rice were also strongly influenced by adhesion of the soil to plant components during the early stage of growth, but gradually the influence of the atmospheric gas phase became predominant. Calculated dietary uptake estimates indicated that, even in rice grown in Japan on soil contaminated with high concentrations of dioxins, the amount of dioxins ingested by humans from rice is extremely small, and the amount of dioxins ingested by livestock from forage rice is similar to that for other forage crops.

Air Pollutants↗

PubMed2006

Follow the patient: process and outcome evaluation of medical students' educational experiences accompanying outpatients.

BACKGROUND: To instill patient-centred attitudes in medical students, several medical schools in Japan have recently started to offer educational experiences in which medical students accompany outpatients throughout entire visits to hospitals. OBJECTIVE: To evaluate the processes and outcomes of the educational experience of Year 5 medical students accompanying outpatients at Nagoya University Hospital. METHODS: An integrated, multimethod approach was adopted using a written survey with open-ended questions for students, focus groups with students, and a written evaluation survey for patients. In all, 99 students completed the survey, 19 students participated in 3 focus groups, and 46 patients participated in the evaluation. RESULTS: Many students were sceptical about the objectives of the exercise. We were able to gain insight into student perceptions about facets of the exercise such as the ratio of students to patients and whether or not students should wear white coats. In particular, there was consensus among students about the importance of the debriefing session after the experience. Students achieved different learning outcomes depending on their particular individual experiences. In the student survey, 49% were satisfied with this experience, 6% were dissatisfied, and 43% were neither. In contrast, patients were highly satisfied with the experience (mean score 4.2 out of 5.0 on a Likert scale). Some students expressed concern about being a burden to patients, while many patients reported feeling emotionally supported by being accompanied by students. CONCLUSION: An integrated approach to programme evaluation, using quantitative and qualitative methods, was useful in the process and outcome evaluation of this new educational experience. The results have been taken into consideration for quality improvement of this curricular element.

Ambulatory Care↗

PubMed2006

Levels of dioxins in rice, wheat, soybean, and adzuki bean cultivated in 1999 to 2002 in Japan and estimation of their intake.

A total of 369 samples of rice (n = 311), wheat (n = 10), soybean (n = 44), and adzuki bean (n = 4) collected from various locations in Japan between 1999 and 2002 were analyzed for PCDDs, PCDFs (PCDD/Fs) and coplanar PCBs. Sampling points within about 1 km of operational municipal waste incinerators that were considered sources of dioxins were defined as "near-source" areas, and all other sampling points were defined as "general" areas. The toxic equivalent quantity (TEQ) values of soybean samples collected from near-source areas were significantly higher (p < 0.05) than those from general areas. A significant difference of TEQs among sampling years in rice in general areas was also found. However, the differences could not be explained by the presence or absence of incineration plants in the area surrounding the sampling point or by a temporal decrease of air pollution. The TEQs of the crops varied widely, but the median value of each crop was quite low, at 0.000021, 0.00013, 0.0000095, and 0.00016 pg-TEQ/g wet wt. in rice, wheat, soybean and adzuki bean, respectively. On the basis of these survey results, the daily intake of PCDD/Fs and coplanar PCBs from rice, wheat, soybean, and adzuki bean was calculated. The daily intakes from these crops were estimated to be 0.0056 pg-TEQ/kg B.W./day on the assumption that "not detected" (ND) could be taken as zero, ND = 0, and 0.18 pg-TEQ/kg B.W./day if ND is put equal to 1/2 LOD (half the limit of detection). In comparison with the tolerable daily intake set in Japan for PCDD/Fs and coplanar PCBs (4 pg-TEQ/kg B.W./day), it was considered that the levels of contamination by PCDD/Fs and coplanar PCBs in these crops cultivated in the environment of Japan do not present a problem.

Dioxins↗

PubMed2005

Levels of dioxins in Japanese fruit in 1999 to 2002 and estimation of their intake.

A total of 148 samples of nine species of fruit were collected between 1999 and 2002 and analyzed for PCDDs, PCDFs (PCDD/Fs) and Coplanar PCBs. Sampling points within about 1 km of operational municipal waste incinerators that were considered sources of dioxins were defined as "near-source" areas, and all other sampling points were defined as "general" areas. The TEQ of apples collected from near-source areas was significantly higher than that from general areas (p < 0.05). 3,3',4,4',5-PeCB (#126) was the main contributor to this difference in TEQs between apples collected from near-source areas and from general area. A principal component analysis performed to estimate the source of this congener revealed that not only the municipal waste incinerators, but also PCBs in the environment were associated with the high TEQ in apples collected from near-source areas. The daily intakes of PCDD/Fs and Coplanar PCBs from the fruits including skin were estimated to be 0.0082 pg-TEQ/kg b.w./day (ND = 0) and 0.072 pg-TEQ/ kg b.w./day (ND = 1/2 LOQ). Though these values are likely to be overestimates, they are far lower than the tolerable daily intake set in Japan for PCDD/Fs and Coplanar PCBs (4 pg-TEQ/kg b.w./day). It is thought that fruit intake is not an important pathway of human exposure to PCDD/Fs and Coplanar PCBs.

Body Burden↗

PubMed2004

RERJ1, a jasmonic acid-responsive gene from rice, encodes a basic helix-loop-helix protein.

Differential screening of a cDNA library constructed using poly(A)(+) RNA from suspension-cultured rice cells treated with jasmonic acid (JA) for 1/2h yielded a cDNA of a gene tentatively named RERJ1 that is upregulated in response to exogenous JA. Northern blot analysis indicated that the RERJ1 mRNA levels peaked at 1/2-1h after the addition of jasmonic acid and then decreased gradually. RERJ1 encodes a transcriptional regulator with a basic helix-loop-helix motif. The phenotypes of transgenic rice plants overexpressing sense or antisense RERJ1 mRNA demonstrated that RERJ1 is involved in the growth inhibition of rice shoots caused by JA. Other biological functions of RERJ1 are discussed from an evolutionary standpoint.

Amino Acid Sequence↗

PubMed2004

The close relationship between postprandial remnant metabolism and insulin resistance.

The aim of this study was to investigate the relationship between postprandial remnant-like particle (RLP) metabolism and insulin resistance (IR). The study group consisted of 52 randomly selected subjects. To evaluate postprandial hyperlipidemia, serum lipid and lipoprotein concentrations during fasting and 4h after the fat-loading test were measured in each subject. IR was assessed using the index of homeostasis model assessment (HOMA-R). The subjects were divided into two groups according to the value of HOMA-R: an IR group (n=17) with a HOMA-R value >/=1.73, and a normal (NR) group (n=35) with a HOMA-R value <1.73. Both fasting and postprandial RLP-cholesterol (RLP-C) concentrations were higher in the IR group than in the NR group (6.2+/-2.6 versus 4.1+/-1.7mg/dl fasting value, and 9.7+/-4.0 versus 5.8+/-2.9mg/dl postprandial value). The changes in RLP-C concentration during the fat-loading test were twice as high in the IR group compared with the NR group (3.5+/-2.4 versus 1.6+/-1.6mg/dl, P=0.0022). The HOMA-R correlated significantly with both fasting and postprandial triglyceride (r=0.41 and 0.43, respectively) and RLP-C (r=0.36 and 0.50, respectively) in all subjects. Multiple regression analysis indicate that postprandial RLP-C concentration was an independent predictor of HOMA-R regardless of age, BMI, and other lipid profiles. Thus, postprandial RLP metabolism is closely related to IR. Atherosclerotic proliferation in IR syndrome may be caused by the accumulation of postprandial remnant lipoproteins after the daily fat intake.

Cholesterol↗

PubMed2003

Pi-face-selective Diels-Alder reactions of 3,4-di-tert-butylthiophene 1-oxide and 1-imide and formation of 1,2-thiazetidines.

3,4-Di-tert-butylthiophene 1-oxide (1a) reacted with a series of electron-deficient alkenic dienophiles at its syn-pi-face relating to the S=O bond to give [4+2] adducts in excellent yields. The 1-oxide 1a also reacted even with angle-strained dienophiles acenaphthylene and norbornene at its syn-pi-face to afford [4+2] adducts; in the latter case, norbornene reacted exclusively at its exo-pi-face. The oxide 1a reacted with dimethyl acetylenedicarboxylate to produce dimethyl 4,5-di-tert-butylphthalate in high yield with spontaneous extrusion of SO from the initial adduct even at room temperature. Similarly, 3,4-di-tert-butylthiophene 1-(p-toluenesulfonyl)imide (3a) reacted with alkenic dienophiles at its syn-pi-face relating to the S=N bond to give [4+2] adducts in good yields. The reaction of 3a with 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) afforded a 1,2-thiazetidine 12a, the first example of S-unoxidized 1,2-thiazetidine, in good yield, through rearrangement of the initial [4+2] adduct. The molecular structure of 12a is discussed on the basis of the X-ray crystallographic analysis. Comparison of the foregoing reactions leads to the conclusion that the 1-oxide 1a is more reactive as a diene than the 1-imide 3a, which is more reactive than 3,4-di-tert-butylthiophene 1,1-dioxide. The origin of the syn-pi-face selectivities of 1a and 3a in Diels-Alder reactions is discussed in terms of the orbital mixing rule and steric effect and also based on B3LYP/6-31G(d) calculations.

Journal Article↗