Cumulation of mycotoxins in maize cobs infected with<Emphasis Type="Italic">Fusarium gramihearum</Emphasis>

Maize cobs withFusarium ear rot were collected at 1986 season and five infected byFusarium graminearum were analyzed for presence of triohothecenes and zearalenone. Collected material was subsampled forFusarium damaged kernels and corresponding axial stems and healthy looking kernels. All investigated cobs contained deoxynivalenol (DON) (range 18.0–131.5 mg/kg) and zearalenone (ZEA) (range 0.38–2.17 mg/kg), in four cobs 15-acetyl-deoxynivalenol (15-AcDON) (range 5.2–6.2 mg/kg) was present and two cobs besides three all metabolites contained 3-acetyl-deoxynivalenol (3-AcD0N) (range 0.5–0.8 mg/kg).The average of individual toxins amount in axial stems: in mg/kg was equal to: DON — 110.36, ZEA — 4.57, 15-AcD0N — 16.66, and 3-AcD0N — 1.32.Fusarium damaged kernels contained in average the following amount (mg/kg) of: DON 77.00, ZEA 0.98, 15-AcD0N 3.78 and 3-AcD0N 0.06. Healthy looking kernels contained DON 1.96 mg/kg and ZEA 0.07 mg/kg only. Cooccurrence of 3-AcDON and 15-AcDON in two samples was an interesting finding. The amount of DON in total cob was highly correlated (r = 0.94) with percentage ofFusarium damaged kernels in given ear.     

中国紫堇属大叶紫堇组的分类与分布

本文叙述大叶紫堇组在紫堇属(Corydalis)中的系统位置以及其分布区的原始性,同时记载了隶属于5个系的23种9变种和1变型,其中有4个新系,7个新种和7个新变种。     

Diterpenoids from Caesalpinia pulcherrima

Three new furanoditerpenoids of the caesalpin-type have been isolated from the roots of Caesalpinia pulcherrima. The structures of these compounds, vouacapen-5α-ol, 6β-cinnamoyl-7β-hydroxy-vouacapen-5α-ol and 8,9,11,14-didehydrovouacapen-5α-ol, were elucidated through interpretation of their spectral data. Sitosterol was also obtained.     

Redistribution of Lyt-bearing T cells in acute murine experimental allergic encephalomyelitis: selective migration of Lyt-1 cells to the central nervous system is associated with a transient depletion of Lyt-1 cells in peripheral blood

Experimental allergic encephalomyelitis (EAE) was induced in SJL/J mice by using two injections of spinal cord homogenate in incomplete Freund's adjuvant supplemented with mycobacteria. Analysis of circulating Lyt-bearing subsets by indirect immunofluorescence during the course of acute EAE revealed the following: 1) during the pre-clinical phase of EAE (1 to 2 days before the onset of paralysis), there was a decrease in the percentage of Lyt-1- but not of Lyt-2-bearing cells in peripheral blood, and of both Lyt-1- and Lyt-2-bearing cells in spleen; 2) with the onset of clinically evident EAE, there was a decrease in both Lyt-1 and Lyt-2 cells in peripheral blood and an increase in the percentage of Lyt-1-bearing cells in pooled inguinal and axillary lymph node; and 3) after these early changes, there was a rapid reconstitution of the percentages of total Lyt-bearing cells and of both Lyt-1- and Lyt-2-bearing cells in peripheral blood. Immunohistochemical analysis of the central nervous system infiltrate revealed that the earliest lesions consisted predominantly of Lyt-1 T lymphocytes, with few Lyt-2 cells present. These results demonstrate that the influx of cells of the Lyt-1 inducer subset to the central nervous system in acute EAE is accompanied by a transient decrease in Lyt-1 cells in peripheral blood.     

类脂过氧化对竹红菌甲素引起膜蛋白光敏交联的影响

本文研究了丙二醛与红细胞膜温育后所形成的交联。当丙二醛浓度在5×10~-4mol/L以上时,膜蛋白发生交联,并且在460nm处有荧光特征峰出现。而甲素光敏所致膜蛋白的交联,在460nm处没有荧光峰,光敏所产生的内源丙二醛量很少,不足以引起红细胞膜反应形成交联。我们还研究了BHT和Vit E两种抗氧化剂对甲素光敏作用的影响。BHT能抑制类脂过氧化,不能抑制膜蛋白巯基的变化和膜蛋白的交联。而Vit E仅不能抑制膜蛋白的交联。以上结果均说明甲素光敏所致膜类脂过氧化是不参与膜蛋白交联的。     

Antibiotic Y: biosynthesis by Fusarium avenaceum (Corda ex Fries) Sacc., isolation, and some physicochemical and biological properties

A compound very similar to the mycotoxin citrinin was observed on thin-layer chromatographic plates during the screening analysis of grain extracts. This compound was produced by 22 of the tested Fusarium avenaceum (Corda ex Fries) Sacc. strains isolated from wheat, triticale, barley, corn, and potatoes. A chemical test confirmed the presence of an unknown compound, which was given the preliminary name of antibiotic Y (indicating yellow fluorescence). The following properties of the new metabolite are described: spectroscopic (UV, infrared, proton nuclear magnetic resonance, fluorescence, and mass spectrometry), phytotoxic, antibiotic (inhibitory effect of bacterial growth), and toxic (toxicity to Artemia salina, chicken embryos, and mouse fibroblasts). Elemental analysis of the compound showed that it had the general formula C15H10O8, in agreement with the mass spectrometric finding that the molecular ion had a molecular weight of 318. The structure of the compound is presently under study.     

滇西北亚高山针叶林带的外生菌根调查

本文报道了滇西北亚高山针叶林带的外生菌根调查工作。对一些亚高山针叶树种的外生菌根及其形态学和解剖学等方面进行了比较。调查结果表明,该地主要树种如长苞冷杉(Abies georgeiOrr.)、丽江云杉(Picea likiangensis Pritz.)、高山松(Pinus densata Mast.)、垂枝云杉(Picea brachytyla(Fr.)Pritz.)以及少数大果红杉(Larix potaninii Batal.)与担子菌类真菌形成外生菌根。长苞冷杉根系所形成的菌根形态多为棍棒型;丽江云杉的菌根形态多为单轴式分枝型;高山松的菌根形态都是二叉状分枝型。     

Freezing pattern in apple seeds as affected by the temperature of fruit storage

Storage of apple fruits ( Pyrus malus L. cv. Golden Delicious) at different temperatures (0, 12 and 35°C) markedly altered the pattern of water freezing in the seeds. Higher temperatures of storage brought about a shift from the sequential to the discontinuous type of freezing in seeds, the low temperature exotherm (LTE) being much more pronounced than the high temperature one (HTE). The occurrence of LTE was highly correlated with embryo death. Fruit storage at higher temperatures also caused a decrease in the threshold super cooling temperature of seeds and of naked embryos, removed from the seed coat and endosperm. The decrease was less pronounced in naked embryos than in intact seeds. The results presented show that the frost resistance of apple seeds relies mainly on the supercooling ability of the embryos and is increased by the presence of seed coat and endosperm. The broad peak of the LTE indicates that, in contrast with other seeds and many super cooling organs, massive ice nucleation in apple seeds occurs within the embryo tissues and that extra organ freezing seems to be of less importance. Therefore, the increased super cooling ability of apple seeds, isolated from fruits stored at higher temperatures, seems to rely on those seed properties that protect embryo cells against heterogeneous ice nucleation.     

Metabolism of Choline Chloride and Its Analogs in Wheat Seedlings

The incorporation rate of choline chloride and allylcholinebromide into wheat protoplasts were rapid compared with theincorporation rate of benzylcholine bromide. Choline chloridewas metabolized via two pathways: choline betaine and choline phosphorylcholine phos-phatidylcholine. Allylcholine bromidewas metabolized via only one pathway: allylcholine phosphorylallylcholine phosphatidylallylcholine, and benzylcholine bromide was notmetabolized at all. These results suggest that the stimulationof photosynthesis (Hyeon et al. 1988) by these compounds iscaused directly by these choline analogs and not by their metabolites. (Received June 29, 1989; Accepted October 20, 1989)     

Intervention trial with selenium for the prevention of lung cancer among tin miners in Yunnan,China

This pilot study evaluated the feasibility and effectiveness of conducting a double-blind clinical trial for the prevention of lung cancer with selenium (Se) in Yunnan Tin Corporation, the People's Republic of China, where the incidence rates of lung cancer are extraordinarily high among the miners. Forty healthy miners were randomized to either 300 μg of Se in high Se malt cakes or an identical placebo of malt cakes daily for one year. Subjects consumed their usual daily diet. The low Se concentrations in plasma (0.05±0.008 μg/mL) and hair (0.442±0.085 μg/g) reflected their low dietary Se intake in the control subjects. In Se-supplemented group, the Se status was increased by 178% for serum and 194.8% for hair. The serum GSHpx activity was increased by 155.7%, whereas the lipid peroxide level was reduced by 74.5% compared to the placebo. The results of UDS assay indicated that the lymphocyte DNA damage induced by ultraviolet irradiation and carcinogen 3,4-benzpyrene could be protected by Se supplementation. Se-supplementation did not affect the liver function test (SGPT), as well as the concentrations of hemoglobin, albumin, and cholesterol. Thus, daily intake of 300 μg Se in form of Se-malt as a chemopreventive measure is safe and effective to humans with low Se status.