ナイリク エンガン チイキ (チテン H68) ノ 2002ネン カキ ノ セキセツ キショウ トクセイ

昭和基地からみずほ基地へのルート上地点H68にて,2002年夏期の積雪表面状態および気象状況について調査した.10月末に地形測量によって同地点の主風向に沿った傾斜を明らかにすると共に,積雪断面観測を行った.なお同時に設置した無人気象観測装置から約2カ月間の気象情報を取得した.気象観測結果については,対応する昭和基地のデータとともに紹介した.Snow features and meteorological conditions at H68, on the route between Syowa and Mizuho Stations, was investigated during summer 2002. The observations were carried out in late October, with the setting up of an automatic meteorological station. The snow surface features were measured to make clear the inclination along the prevailing wind direction, and snow observations were made on a vertical dug snow wall. Continuous climatic records in the following two months, obtained by the meteorological station, are introduced together with the corresponding data at Syowa Station

Swainsonine reduces 5-fluorouracil tolerance in the multistage resistance of colorectal cancer cell lines

<p>Abstract</p> <p>Background</p> <p>Drug resistance is a major problem in cancer chemotherapy. Acquisition of chemo-resistance not only reduces the effectiveness of drugs, but also promotes side effects and markedly reduces the patient's quality of life. However, a number of resistance mechanisms have been reported and are thought to be the reason for the difficulties in solving drug-resistance problems.</p> <p>Result</p> <p>To investigate the mechanisms of drug resistance, a set of cell lines with different levels of sensitivity and possessing different mechanisms of resistance to 5-fluorouracil (5-FU) was established from a colorectal cancer cell line. The expression of thymidylate synthase, orotic acid phosphoribosyltransferase and dihydropyrimidine dehydrogenase, which are well known to be related to drug resistance, differed among these cell lines, indicating that these cell lines acquired different resistance mechanisms. However, swainsonine, an inhibitor of N-glycan biosynthesis, reduced 5-FU-tolerance in all resistant cells, whereas the sensitivity of the parental cells was unchanged. Further analysis of the N-glycan profiles of all cell lines showed partial inhibition of biosynthesis and no cytotoxicity at the swainsonine dosage tested.</p> <p>Conclusion</p> <p>These observations suggest that N-linked oligosaccharides affect 5-FU resistance more widely than do drug-resistance related enzymes in colorectal cancer cells, and that the N-glycan could be a universal target for chemotherapy. Further, swainsonine may enhance the performance of chemotherapy by reducing tolerance.</p

Effect of olfaction on the sensitivity of bitter taste

味覚と嗅覚の受容は異なる経路で脳へと伝達される一方、嗅覚の存在によって味の感じ方が変わることが知られているが、香気成分が味成分の受容そのものに与える影響については明確にされていない。本研究では、ラットを用いた飲水選択嗜好実験を行い、香気成分の添加により苦味溶液の選択率に変化が見れるかどうかを確認することにより、香気成分が苦味の感受性に与える影響について検討した。濃度の異なる塩酸キニーネ水溶液を用いた４瓶選択嗜好実験では、通常水群、香気水群（苦味溶液に10ppmの酪酸ブチルを添加）ともに苦味濃度が増加するほど嗜好率が低下したが、香気水群では0.001mMの苦味溶液で嗜好率が有意に増加した（p＜0.01)。一方、不快臭を示すヘキサナールを用いた場合では、個体差が大きく有意差は認められなかった。ヒトを用いた官能検査では、10ppmの酪酸ブチル、ヘキサナール、イソバレルアルデヒドのいづれの添加でも、0.01mM塩酸キニーネ水溶液の苦味を増加させた。これらの結果から、酪酸ブチルのような香気成分は苦味の感受性を変化させることが示唆され、香気成分の添加により苦味を修飾できる可能性が示された。It is known that not only taste but also olfaction (aroma) largely contributes the flavor of food, however, there is insufficient information about the interaction of olfaction and sensitivity of taste. In the present study, we investigated the effect of olfaction on the sensitivity of bitter taste by four-bottle preference test using rats. Ten male Sprague Dawley rats (6-weeks age) were divided into two groups: control and odor groups, and the drinking water of the odor group were added 10 ppm of butyl acetate (fruit-like odor). Rats were provided four bottles of drinking water containing different concentrations of quinine hydrochloride (0, 0.001, 0.01, 0.1 mM), and the preference rates were measured. The positions of the 4 bottles were randomized and switched every 48 h to avoid positional preference. During 8 days of experimental period, the volume of the 0.001 mM quinine hydrochloride consumed by the rats in the odor group was higher than that in the control group (p<0.01). In contrast, the addition of 10 ppm of 1-hexanal (off-flavor odor) had no effect on the preference rate of the 0.001 mM quinine hydrochloride by rats. Further, any addition of 10 ppm of butyl acetate, 1-hexanal, or isovaleraldehyde increased the sensitivity of bitter taste of 0.01mM quinine hydrochloride by human sensory evaluation. The results indicate that some odors such as butyl acetate may modify sensitivity of bitter taste in human and rat

A Single Nucleotide Polymorphism within the Acetyl-Coenzyme A Carboxylase Beta Gene Is Associated with Proteinuria in Patients with Type 2 Diabetes

It has been suggested that genetic susceptibility plays an important role in the pathogenesis of diabetic nephropathy. A large-scale genotyping analysis of gene-based single nucleotide polymorphisms (SNPs) in Japanese patients with type 2 diabetes identified the gene encoding acetyl-coenzyme A carboxylase beta (ACACB) as a candidate for a susceptibility to diabetic nephropathy; the landmark SNP was found in the intron 18 of ACACB (rs2268388: intron 18 +4139 C > T, p = 1.4×10−6, odds ratio = 1.61, 95% confidence interval [CI]: 1.33–1.96). The association of this SNP with diabetic nephropathy was examined in 9 independent studies (4 from Japan including the original study, one Singaporean, one Korean, and two European) with type 2 diabetes. One case-control study involving European patients with type 1 diabetes was included. The frequency of the T allele for SNP rs2268388 was consistently higher among patients with type 2 diabetes and proteinuria. A meta-analysis revealed that rs2268388 was significantly associated with proteinuria in Japanese patients with type 2 diabetes (p = 5.35×10−8, odds ratio = 1.61, 95% Cl: 1.35–1.91). Rs2268388 was also associated with type 2 diabetes–associated end-stage renal disease (ESRD) in European Americans (p = 6×10−4, odds ratio = 1.61, 95% Cl: 1.22–2.13). Significant association was not detected between this SNP and nephropathy in those with type 1 diabetes. A subsequent in vitro functional analysis revealed that a 29-bp DNA fragment, including rs2268388, had significant enhancer activity in cultured human renal proximal tubular epithelial cells. Fragments corresponding to the disease susceptibility allele (T) had higher enhancer activity than those of the major allele. These results suggest that ACACB is a strong candidate for conferring susceptibility for proteinuria in patients with type 2 diabetes

Snow features and meteorological conditions on the coastal snow plateau (H68) observed during summer 2002

Snow features and meteorological conditions at H68, on the route between Syowa and Mizuho Stations, was investigated during summer 2002. The observations were carried out in late October, with the setting up of an automatic meteorological station. The snow surface features were measured to make clear the inclination along the prevailing wind direction, and snow observations were made on a vertical dug snow wall. Continuous climatic records in the following two months, obtained by the meteorological station, are introduced together with the corresponding data at Syowa Station