Modulation of Th1- and Th2-type immune response in infant mouse after prenatal exposure to volatile organic compound

胎児期､乳児期は化学物質に対して高感受性の時期であるとも云われており､多種多様な化学物質による子供の健康影響とそのメカニズムを把握することは生体機能の正常な発達の観点から重要と考えられている。本研究では低濃度トルエンの胎児期曝露が仔マウスの全身および局所でのTh1/Th2免疫応答に及ぼす影響についてグラム陽性菌細胞壁成分ペプチドグリカン(PGN; peptidoglycan)との併用, 非併用下で検討した。その結果､5,50ppm トルエンのみもしくはPGN刺激との併用曝露は血中や脾臓においてTh1及びTh2型免疫応答に関係するいくつかの免疫パラメーター(総Ig抗体サブクラスの産生レベルや転写因子T-bet, GATA-3, Foxp3のmRNA発現等)をかく乱することを明らかした

ダイジョ DIOSCOREA ALATA L. ノ セイチョウ カテイ ニ オケル ケイヨウ コンケイ ノ ガンスイリツ ノ ヘンカ

関東地域で収穫可能なダイジョの1品種を用いて,地下部の塊茎のみならず塊茎デンプンのソースである地上部の茎葉における生長過程の含水率の変化を調べた。その結果,生長時期の推移に伴う茎葉含水率と塊茎の含水率の変化には顕著な差異が認められた。すなわち,茎葉の含水率は生長期間の大半を通して緩やかに減少するが,塊茎の含水率は肥大初期に急速に減少し,その後横這いから緩やかな減少傾向を示した。塊茎では,肥大初期にはその組織が主に若い柔組織細胞で構成されているため水分含量が高いが,肥大が旺盛になるにつれてデンプンの蓄積が進み,それに伴って含水率が低下したものと推測された。このことから,ダイジョの塊茎の含水率の推移は,品種の塊茎成熟度の特性を評価する有効な方法となる可能性が考えられた。Greater yam (Dioscorea alata L.) is one of the yams and still a staple food tuber crop in parts of developing and self-sustaining agriculture in tropical Asia. Yam tuber contains high moisture content, which changes during growth stages. The present research investigated changes of moisture content in tubers and tops of an early cultivar, which is able to riper in the Kanto Metropolitan area. According to the results, remarkable differences were observed in changes of moisture content of tubers and tops of growing plants. Moisture content of tops gradually decreased throughout whole growth stages, while that of tubers rapidly decreased at the early stage of growth and thereafter tended to reduce gradually. In the earlier stage of growth, tubers consisting of young parenchyma seems to maintain higher moisture content. But as the growth of tuber progresses, starch is accumulated and moisture content of the tuber is thought to be reduced. From these results, the changes of moisture content in tubers will be an useful indicator for tuber maturity

ダイジョ DIOSCOREA ALATA L. ノ ソシキバイヨウ ニ ヨル マイクロチューバケイセイ

ダイジョ(Dioscorea alata L.)の地方品種`Nani Niyaka\u27を無菌培養した植物の節部切片培養を行い,マイクロチューバ(MT)形成に及ぼす植物成長調節物質,培地の種類,培地のショ糖濃度,ならびに照明時間の効果について検討した。その結果,NAA, ABA, KINおよびPDJなど4種類の植物成長調節物質は,MT形成に顕著な効果を示さなかった。特にNAAとPDJはMT形成に抑制する傾向が見られた。3種類の基本培地,4水準の照明時間,5水準のショ糖濃度について実験を行った結果,MS培地に10%程度のショ糖を添加し,16時間照明で培養するのがMT形成に最も効果的であることが分かった。ダイジョのMT形成には,培養植物体内の炭水化物が必要と考えられる。培地の窒素の種類と濃度がMT形成に影響し,窒素成分に富む培地でMT形成が促進された。これらの結果から,植物体内の炭水化物と窒素の絶対量がMT形成の促進要因となっていると考えられる。This study aims at finding factors affecting microtuberization of greater yam (Dioscorea alata L.). None of four plant growth regulators, NAA, ABA, kinetin and PDJ, were promotive to form microtubers. The MS medium adding 10% sucrose under 16 hours illumination remarkably promoted to form microtubers. But NAA and PDJ tended to inhibit tuberization. The three-way arrangement experiments with three different culture media, five levels of sucrose concentration, and four levels of illumination time were conducted and disclosed that tuberization was the most active on the MS medium with the addition of 10% sucrose under 16 hours period of illumination a day. The essential to microtuberization of greater yam is considered to be the concentration of carbohydrate in cultured plants. Sources and concentrations of nitrogen in the culture media affected the formation of microtubers. Nitrogen-rich media promoted microtuberization

ダイジョ DIOSCOREA ALATA L. ノ セイチョウ カテイ ニ オケル ケイヨウ コンケイ ノ ガンスイリツ ノ ヘンカ

関東地域で収穫可能なダイジョの1品種を用いて,地下部の塊茎のみならず塊茎デンプンのソースである地上部の茎葉における生長過程の含水率の変化を調べた。その結果,生長時期の推移に伴う茎葉含水率と塊茎の含水率の変化には顕著な差異が認められた。すなわち,茎葉の含水率は生長期間の大半を通して緩やかに減少するが,塊茎の含水率は肥大初期に急速に減少し,その後横這いから緩やかな減少傾向を示した。塊茎では,肥大初期にはその組織が主に若い柔組織細胞で構成されているため水分含量が高いが,肥大が旺盛になるにつれてデンプンの蓄積が進み,それに伴って含水率が低下したものと推測された。このことから,ダイジョの塊茎の含水率の推移は,品種の塊茎成熟度の特性を評価する有効な方法となる可能性が考えられた。Greater yam (Dioscorea alata L.) is one of the yams and still a staple food tuber crop in parts of developing and self-sustaining agriculture in tropical Asia. Yam tuber contains high moisture content, which changes during growth stages. The present research investigated changes of moisture content in tubers and tops of an early cultivar, which is able to riper in the Kanto Metropolitan area. According to the results, remarkable differences were observed in changes of moisture content of tubers and tops of growing plants. Moisture content of tops gradually decreased throughout whole growth stages, while that of tubers rapidly decreased at the early stage of growth and thereafter tended to reduce gradually. In the earlier stage of growth, tubers consisting of young parenchyma seems to maintain higher moisture content. But as the growth of tuber progresses, starch is accumulated and moisture content of the tuber is thought to be reduced. From these results, the changes of moisture content in tubers will be an useful indicator for tuber maturity

Nanoparticles and Neurotoxicity

Humans are exposed to nanoparticles (NPs; diameter < 100 nm) from ambient air and certain workplaces. There are two main types of NPs; combustion-derived NPs (e.g., particulate matters, diesel exhaust particles, welding fumes) and manufactured or engineered NPs (e.g., titanium dioxide, carbon black, carbon nanotubes, silver, zinc oxide, copper oxide). Recently, there have been increasing reports indicating that inhaled NPs can reach the brain and may be associated with neurodegeneration. It is necessary to evaluate the potential toxic effects of NPs on brain because most of the neurobehavioral disorders may be of environmental origin. This review highlights studies on both combustion-derived NP- and manufactured or engineered NP-induced neuroinflammation, oxidative stress, and gene expression, as well as the possible mechanism of these effects in animal models and in humans

Indoor Volatile Organic Compounds and Chemical Sensitivity Reactions

Studies of unexplained symptoms observed in chemically sensitive subjects have increased the awareness of the relationship between neurological and immunological diseases due to exposure to volatile organic compounds (VOCs). However, there is no direct evidence that links exposure to low doses of VOCs and neurological and immunological dysfunction. We review animal model data to clarify the role of VOCs in neuroimmune interactions and discuss our recent studies that show a relationship between chronic exposure of C3H mice to low levels of formaldehyde and the induction of neural and immune dysfunction. We also consider the possible mechanisms by which VOC exposure can induce the symptoms presenting in patients with a multiple chemical sensitivity