Nitrocapsanthin and nitrofucoxanthin, respective products of capsanthin and fucoxanthin reaction with peroxynitrite

The in vitro reactivity of capsanthin (1) and fucoxanthin (2) with peroxynitrite was investigated, and the reaction products produced by scavenging with peroxynitrite were analyzed. (14'Z)-Nitrocapsanthin (3) and 12-nitrocapsanthin (4) were isolated from the products of the reaction of capsanthin with peroxynitrite. Similarly, (14Z)-15-nitrofucoxanthin (5), (11Z)-11-nitrofucoxanthin (6), and (14Z,9'Z)-15-nitrofucoxanthin (7) were obtained from the reaction of peroxynitrite reaction with fucoxanthin. Capsanthin and fucoxanthin inhibited the nitration of tyrosine by peroxynitrite. Furthermore, nitrocapsanthins (3 and 4) and nitrofucoxanthins (5 and 6) exhibited an inhibitory effect on Epstein-Barr virus early antigen activation in Raji cells and an antiproliferative effect on human pancreatic carcinoma. Moreover, nitrocapsanthins (3 and 4) inhibited carcinogensis of mouse skin tumors initiated by 7,12-dimethylbenz[a]anthracene (DMBN).     

A new spore precipitator with polarized dielectric insulators for physical control of tomato powdery mildew

ABSTRACT In an attempt to physically protect greenhouse tomato plants from the powdery mildew fungus Oidium neolycopersici, we developed a new electrostatic spore precipitator in which a copper wire conductor is linked to an electrostatic generator and covered with a transparent acrylic cylinder (insulator). The conductor was negatively charged by the generator, and the electrostatic field created by the conductor was used to dielectrically polarize the insulator cylinder. The dielectrically polarized cylinder also produced an electrostatic force without a spark discharge. This force was directly proportional to the potential applied to the conductor and was used to attract conidia of the pathogen. The efficacy of this spore precipitator in protecting hydroponically cultured tomato plants from powdery mildew was evaluated in the greenhouse. The hydroponic culture troughs were covered with a cubic frame installed with the spore precipitator, and the disease progress on precipitator-guarded and unguarded seedlings was traced after the conidia were disseminated mechanically from inoculum on tomato plants. Seedlings in the guarded troughs remained uninfected during the entire experiment, in spite of rapid spread of the disease to all leaves of the unguarded seedlings.     

低锌猪饲料的配合

猪粪中的大量磷、氮会对环境造成污染。一些微量元素,如锌可能导致可耕地严重的金属污染。据报道,当土地中锌含量为10、150、200mg/kg干土时,会抑制稻谷、小麦和萝卜的生长及产量(EnviromentAgency,GovernmentofJapan,1973)。长期使用肉鸡垫草和猪粪会增加土地及牧草的锌含量(Kingery,1994)。一些研究结果表明,猪粪中高锌含量造成植物中毒(Sajwa,1996)。日本政府规定可耕地干土中的锌含量应在120mg/kg以下。商品猪饲料锌含量通常在100mg/kg以上,锌在猪体内的沉积相当少,其表观吸收率几乎可以忽略不计。当日粮锌含量为100mg/kg、日粮表观…     

Marigold Leaf Spot Caused by Alternaria tagetica New to Japan

In October 1998, a disease causing mainly foliar necrotic lesions was found on African marigold (Tagetes erecta) and French marigold (T. patula) grown in Miyagi Prefecture, Japan. Similar lesions also developed on stems and flowers, resulting in early blight of the affected organs. Plants with numerous lesions withered rapidly. A mitosporic fungus isolated repeatedly from the diseased plants was identified as Alternaria tagetica and demonstrated to cause the disease. The disease, as well as the fungus, is new to Japan. We propose the name “hanten-by?”, which means leaf spot in Japanese, for this disease. Received 5 April 2000/ Accepted in revised form 31 May 2000     

Confirmation of nitrogen fixation in two tropical grasses by 15N2 incorporation

Intact soil cores containing plants of Paspalum notatum or Digitaria decumbens were selected with the acetylene reduction method, and then exposed to ¹⁵N₁₅ to confirm nitrogen fixation in tropical grass-bacteria associations. In a preliminary experiment with P. notatum¹⁵N₂ incorporation was slow but progressive during 24 h in roots but translocation to rhizomes and leaves ceased after 17h. With improved assay chambers, enrichments of 0.151 and 0.563 ¹⁵N atom % excess were obtained in roots of D. decumbens cv transvala and P. notatum systems respectively, after 3 days. Enrichments in rhizomes were similar to those of roots; however in the leaves only 8% of root enrichment was observed. The addition of sucrose to the soil doubled N₂-fixation in roots in both grass species studied, but did not result in increased incorporation into the leaves of P. notatum.     

Middle upper beak fracture in a Red-crowned crane that completely recovered with external skeletal fixation

An adult Red-crowned crane in captivity that had a displaced compound fracture of the middle upper beak caused by an accident was treated by using Type I-a external skeletal fixator (ESF). The ESF that was equipped with a unilateral epoxy putty fixator and with five half-pins was fixed on the premaxilla bone. The crane with the ESF on the beak was able to feed smoothly by itself. The ESF was removed 49 days after the first surgery. Beak malocclusion, which was observed in the latter half period of fixing, spontaneously improved within one month after removal of the ESF. This is the first successful case of repair of an upper beak fracture in a Red-crowned crane.     

Ruminant forestomach and abomasal mucormycosis under rumen acidosis

Spores of Absidia corymbifera were inoculated orally into sheep with ruminal acidosis produced by feeding barley. Lesions, which developed in forestomachs of all four inoculated cases, included desquamation of superficial layers of the mucosae and focal necrosis from lamina propria to muscular layers. Granulomatous lesions were in the submucosa of three sheep. Lesions in the abomasum (two sheep) included focal necrosis, diffuse hemorrhages, and infiltration of neutrophils. All lesions were accompanied by mycotic proliferation. These results show that A. corymbifera can invade forestomach mucosae through degenerate epithelium resulting from ruminal acidosis.