不同茶树品种化学成分与红碎茶品质关系的研究

用高效液相色谱法分析了６个茶树品种鲜叶样品的儿茶素类、咖啡碱、没食子酸含量和红碎茶茶黄素类（ＴＦｓ）的组成及其与红碎茶品质之间的关系。结果表明，茶黄素（ＴＬ，Ｘ＿１）、茶黄素－３－没食子酸酯（ＴＦ３Ｇ，Ｘ＿２）和茶黄素－３．３′双没食子酸酯（ＴＦ３．３’ＤＧ，Ｘ＿３）的ＨＰＬＣ峰面积（１×１０￣５ｍｍ￣２）与红碎茶感官审评品质总分（Ｙ＿（ｔｏｔａｌ），分）和滋味得分（Ｙ＿（ｔｓｔｅ））分）之间存在显著的（Ｐ＜０．０５）三元线性回归关系。主成分分析结果表明，茶树品种鲜叶的咖啡碱与（一）ＥＧＣ，（一）ＥＧＣ与（＋）ＥＣ和（＋）ｃ含量分别具有较高相关性，因此，咖啡碱、（一）ＥＣＧ，（一）ＥＧＣＧ含量分别作为第一、二、三主成分或综合因子，可以较好地反映茶树品种鲜叶形成ＴＦｓ以及红碎茶品质的潜力．     

环孢素A对咖啡因刺激下的L6细胞钙蛋白酶活性的影响

探究钙调神经磷酸酶抑制剂环孢素A是否调节骨骼肌细胞钙蛋白酶活性.将分化8 d后的L6肌管细胞随机分为4组,即对照组、环孢素组、咖啡因组、环孢素+咖啡因组.急性刺激5 h后收集细胞,提取并定量细胞总蛋白和肌原纤维蛋白,用荧光定量法测定钙蛋白酶的活性.结果显示,咖啡因刺激后肌原纤维蛋白含量下降,同时钙蛋白酶活性明显增加;加...     

Fish hepatocyte glycogen phosphorylase – a sensitive indicator for hormonal modulation

The absence of a reproducible method for the assay of glycogen phosphorylase (GPase) in isolated fish hepatocytes has made the interpretation of hormone-induced glycogenolysis data difficult. This study presents such an assay and demonstrates its sensitivity to hormonal activation. The enzyme is assayed in the reverse direction using glucose 1-phosphate (G1-P) and glycogen as substrates and uses standard methods for the quantification of the liberated inorganic phosphate. The assay is highly reproducible, sensitive, and provides an excellent means to follow small and rapid changes in enzyme phosphorylation status following the addition of hormones. We show for hepatocytes isolated from rockfish (Sebastes caurinus) and brown bullhead (Ameiurus (Ictalurus) nebulosus) that small concentrations of three model hormones, namely epinephrine (catfish), norepinephrine, and prostaglandin E₂ (rockfish), lead to the rapid, concentration and time-dependent conversion of existing GPase into the active GPase a form. Some of the enzyme seems to be impervious to hormonal activation, as the highest %GPase a never reaches 100%. We provide evidence that changes in enzyme phosphorylation status provide a better short-term insight into hormone-dependent activation than estimates of glucose or some other end products, that usually must accumulate for long periods before detection is possible. Our data also show that GPase in freshly isolated hepatocytes is already in an activated state and cells should be given a period of rest for several hours before hormonal studies involving glycogen breakdown or the cAMP cascade are initiated.     

正交投影法解析色谱重叠峰的研究──咖啡、茶叶中咖啡碱、茶碱与可可碱的定性定量分析

咖啡、茶叶中茶碱和可可碱的色谱峰为全包含峰，如果用常规方法对其进行定性、定量，则误差很大．本文以正交投影法对咖啡、茶叶的三维色谱进行处理，从中解析出了各组分的色谱流出曲线，并进行了定量分析．结果表明，正交投影法解决了常规方法中以保留时间定性的不可靠性，以及重叠色谱峰的定量难题．因而，它是对植物体中生物碱进行定性定量的有效方法之一．     

受精液中肝素和咖啡因的组合对牛卵母细胞体外受精的影响

采用２种肝素浓度（１０，３０ｍｇ／Ｌ）与３种咖啡因浓度（２．５，５，１０ｍｍｏｌ／Ｌ）的交叉组合，以３０ｍｇ／Ｌ肝素的受精液为对照，探讨肝素和咖啡因对牛卵母细胞体外受精的影响，并确定受精后将卵母细胞移至单层细胞的合适时间。结果表明，当卵母细胞在受精后５ｈ移至单层细胞时，１０ｍｇ／Ｌ肝素加５ｍｍｏｌ／Ｌ咖啡因或３０ｍｇ／Ｌ肝素加２．５ｍｍｏｌ／Ｌ咖啡因的体外受精效果最好，二者的囊胚率和囊胚孵化率分别为５６．９％±７．０，８１．１％±１２．７及５６．９％±７．０，７８．９％±９．８。     

An outbreak of Haemophilus agni-Histophilus ovis septicaemia in lambs

Extract

An outbreak of an acute, highly fatal septicaemia caused by Haemophilus agni-Histophilus ovis (H-H) infection occurred in a group of 700 lambs aged 4–5 months. The clinical signs included dullness, disinclination to move, lameness and death within 24 hours. About 74 lambs died in the course of 4–5 weeks. Five dull, fevered lambs were treated with penicillin-streptomycin or oxytetracycline. They survived but developed chronic polyarthritis and were unthrifty.     

普洱茶中咖啡碱在小鼠体内的吸收情况研究

对比研究了普洱茶、绿茶和咖啡碱以3种剂量（5、25和50 mg·kg^-1·d^-1）对小鼠灌胃给药之后,咖啡碱在小鼠体内的吸收情况。研究结果显示,以咖啡碱剂量为25和50 mg·kg^-1·d^-1,分别灌胃小鼠普洱茶、绿茶和咖啡碱纯品,普洱茶灌胃后小鼠血浆中咖啡碱的水平明显低于灌胃绿茶和咖啡碱组。同时,用AUC（30-150 min）梯形计算公式计算咖啡碱吸收总量,灌胃咖啡碱剂量为25和50 mg·kg^-1·d^-1的普洱茶血液中咖啡碱总量也明显小于灌胃绿茶和咖啡碱（P<0.05）。研究结果表明,相同咖啡碱剂量下,普洱茶中的其它成分能够显著抑制咖啡碱的体内吸收。     

离心萃取-紫外光度法快速测定茶饮料中的咖啡因

建立以三氯甲烷为提取剂,以离心萃取为提取方法,以276 nm为检测波长的茶饮料中咖啡因的检测方法。结果表明,吸光度A与咖啡因浓度C在5.324～16.940 mg/L呈现良好的线性关系,相关系数为0.999 5,回收率为97.6%～99.4%。该方法测定快速、准确度高,适用于茶饮料中咖啡因的测定。     

Autopsy report for a caffeine intoxication case and review of the current literature

Caffeine (1,3,7-trimethylxanthine) is a popular mild central nervous system stimulant found in the leaves, seeds and fruits of various plants and in foodstuffs such as coffee, tea, and chocolate, among others. Caffeine is widely used and is not associated with severe side effects when consumed at relatively low doses. Although rarely observed, overdoses can occur. However, only a few fatal caffeine intoxication cases have been reported in the literature. Herein, we report the pathological examination results and information on caffeine concentrations in the blood, urine and main organs in a fatal caffeine intoxication case. Even though high caffeine concentrations were found in the systemic organs, no caffeine-related pathological changes were detected.     

聚乙二醇胁迫下茶树咖啡碱合成酶基因的差异表达

应用荧光定量PCR的方法对茶树咖啡碱合成酶基因在PEG胁迫下的表达情况进行分析。结果显示,与对照相比,PEG胁迫下咖啡碱合成酶基因表达量随着胁迫时间延长呈现出先升高后降低的变化特点,胁迫的12 h内表达量明显上调,胁迫6 h表达量最大,之后明显下降,相对表达量变化范围为0.13~10.97。