体育运动和脂质代谢

一般健康人总胆固醇(T-Ch)、甘油三酯(TG)、高密度和低密度脂蛋白胆固醇(HDL-ch,LDL-cH)的含量随年令而增加。中年组(45-59)HDL-Ch平均值较低,男比女低,这与中国人男性45岁以后患冠心病(CHD)多于女性相吻合。冠心病及脑中风患者的HDL-ch含量比健康人低(P<0.05)。运动员的HDL-Ch含量明显高于一般健康人(P<0.01),其均值且高于不易患动脉粥样硬化(AS)的八种哺乳动物的均值(60.40mg/d1)。运动员的T-ch、TG和HDL-Ch含量低于健康人。     

薇甘菊和飞机草抗氧化物和膜脂过氧化物对光照和土壤水分的响应

田间温室控制条件下研究入侵杂草薇甘菊(Mikania micrantha)和飞机草(Chromolaena odoratum)在不同光照(高、中、低光照)和土壤水分(高、中、低水分含量)交互作用下, 叶片超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性, 脯氨酸(Pro)、谷胱甘肽(GSH)以及膜脂过氧化物丙二醛(MDA)含量的变化, 探讨两种杂草对不同光照和土壤水分交互作用的生理适应性。结果表明: 高光下低水处理的两种杂草MDA含量均显著高于全水处理, 表现出明显的胁迫。此胁迫条件下薇甘菊通过迅速提高SOD和CAT活性, 提高Pro和GSH含量来清除活性氧, 维持代谢平衡, 但不能在干旱条件下维持较长时间; 飞机草的SOD活性、Pro和GSH含量也迅速提高, 在高光缺水的适应性响应中起了重要作用, CAT则未能发挥保护作用。相对于其他光照, 低光显著降低了薇甘菊的SOD、CAT活性和MDA含量, 而对飞机草上述指标的影响较小, 说明低光降低了两种杂草尤其是薇甘菊的抗氧化物代谢水平。     

椿亚科和麻楝亚科植物化学成分和生物活性的研究进展

本文简要综述了楝科椿亚科香椿属(Toona)和洋椿属(Cedrela)以及麻楝亚科麻楝属(Chukrasia)、桃花心木属(Swietenia)和非洲楝属(Khaya)植物的化学成分和生物活性的研究情况。     

激素和活性多肽

<正>考察了用Fusarium roseum"Gibbosum"培养将α一(14C)zearalenol和β-(14C)一zearalenol(zeranol)转化成为zearalen-one的转化过程。将已灭菌的潮湿稻谷(无离子水中)播于接种     

钙离子和水杨酸诱导灵芝多糖和三萜的合成

灵芝多糖和三萜是灵芝主要的药理活性物质。如何提高液体发酵中灵芝多糖和三萜的含量是目前研究的热点。本研究以J‐7/AL‐2菌株为例,在灵芝的液体发酵中加入10mmol/L钙离子诱导,多糖含量比对照提高34%,三萜含量提高64%。在发酵液中加入150μmol/L水杨酸(SA)诱导,多糖含量提高57.54%,三萜含量提高37.19%。在灵芝的液体发酵第12天加入10mmol/L钙离子和150μmol/L水杨酸,三萜含量提高46.9%。在不同诱导条件下,三萜的高效液相图谱(HPLC)显示钙离子与对照的差异性比较大。灵芝三萜关键酶基因的表达也有所不同。水杨酸提高法尼基焦磷酸合酶(FPS)、鲨烯合酶(SQS)和羊毛兹醇合酶(LS)基因的表达量,而钙离子和钙离子与水杨酸共同处理提高3‐羟基‐3‐甲基戊二酰辅酶A合酶(HMGS)、3‐羟基‐3‐甲基戊二酰辅酶A转录水平还原酶(HMGR)、焦磷酸甲羟戊酸脱羧酶(MVD)、法尼基焦磷酸合酶(FPS)、鲨烯合酶(SQS)和羊毛兹醇合酶(LS)6个三萜关键酶基因的表达量。在3种处理下,都是SQS的基因表达量提高最多,推测SQS基因是灵芝三萜合成过程中重要的基因。     

淋巴因子和干扰素

<正> 852886通过培养携带来自巨噬细胞、NK细胞的人干扰素基因的酵母菌获得干扰素组分[专,日]/Yoshida,k./J 5 9055—836:22.09.82-JP-165371(31.03.84)22.09.82as 165371.84-117680/19(2页)[译自DBA,1984,3(15),84-07075]本文叙述了通过嵌入人体干扰素编码基     

遮荫对水曲柳和蒙古栎光合、生长和生物量分配的影响

为探讨水曲柳(Fraxinus mandshurica)和蒙古栎(Quercus mongolica)苗期对光的适应性及其生长最适光强,设置4种光环境(全光(FL)、75%光(LS)、50%光(MS)、25%光(HS)),观测了2年生水曲柳和蒙古栎苗木气体交换参数、叶绿素含量(Chl)和比叶重(LMA)、生长及生物量的分配。结果表明:随着光强的减弱,2个树种的LMA、单位叶鲜质量(LFA)和根冠比均呈下降趋势;叶绿素含量(Chl)呈上升趋势,且差异显著(p<0.05);光补偿点(LCP)和暗呼吸速率(Rd)呈"N"形变化,但差异均不显著(p>0.05);水曲柳的最大光合速率(Pmax)在HS处理下最大,Rd在HS处理下最小;蒙古栎的最大光合速率(Pmax)在LS处理下最大,Rd也较小;在全光处理下苗高增量均低于HS处理,地径增量均高于HS处理。研究结果进一步确定水曲柳苗期具有一定的耐荫性,在弱光强下生长较好;蒙古栎苗期对光照要求较高,在相对较强光照下生长较好。     

淋巴因子和干扰素

<正> 854133 用T细胞杂交瘤生产γ-干扰素[英]/Grane,I.…//Immunology.-1984,53(4).-855～859[译自DBA,1985,4(3),85-01206]由粉碎的木菠萝种籽中提取植物血凝素夹可宁,用它来刺激从健康成人末稍血液所取得的单核细胞(PBMC)及T淋巴细胞。     

恒温和变温下中国对虾生长和能量收支的比较

对比研究了模拟自然昼夜温度变化节律的4个变温(22±2)、(25±2)、(28±2)和(31±2)℃与相应的恒温22、25、28和31℃下中国对虾(F ennerop enaeus ch inensis O sbeck)生长和能量收支的差异。结果表明,对虾在(22±2)℃、(25±2)℃和(28±2)℃变温条件下的生长率显著高于相应的恒温,但(31±2)℃与恒温31℃相比没有显著差异。与相应的恒温相比,(25±2)℃、(28±2)℃和(31±2)℃变温下对虾的摄食量显著增大,(22±2)℃、(25±2)℃和(28±2)℃变温下对虾的饵料转化率则显著提高。但变温下对虾对食物的消化率与相应的恒温相比没有显著差异。能量收支研究结果则发现,(22±2)℃、(25±2)℃和(28±2)℃变温下对虾摄食能中,用于生长的能量比例显著增加,而(31±2)℃与31℃相比则未见显著差异。从而表明,变温促长的主要机制可归因于变温下摄食量的增大、饵料转化率的提高及其摄食能中用于生长能比例的增加。     

综合遗传学公司克隆和表达猪和马的繁殖激素

综合遗传学(Integrated Genetics)公司(Framingham,MA)已经克隆和表达了三种动物的繁殖激素。rDNA激素-马卵泡激素(eFSH)、马促黄体激素(eLH)和猪卵泡激素(pFSH)--预期在提高马以及繁殖力低的家畜的生殖率方面,有重要应用,调节猪的生殖周期对经济收益是十分紧要的。     

壳聚糖酶的克隆表达与壳寡糖的制备分析

目的:克隆壳聚糖酶基因于大肠杆菌中实现高表达,制备壳寡糖。方法:以枯草芽孢杆菌总DNA为模板扩增壳聚糖酶基因(CSN),克隆至载体pET23a(+)上,转化菌株BL21(DE3)。重组子经0.5 mmol/L IPTG诱导后,SDS-PAGE和质谱检测与鉴定重组酶。酶纯化后水解壳聚糖,薄层色谱分析其水解产物。结果:质谱证明壳聚糖酶(31.5kDa)成功表达,表达量占菌体总蛋白的45%左右。纯化后重组酶浓度为900 mg/L,纯度95%、回收率85%,酶活力为10 000 U/mg。壳聚糖降解产物为壳二糖至壳四糖。结论:原核表达载体pET23a(+)-CSN构建正确,壳聚糖酶表达量与活性高,适用于水解壳聚糖制备壳寡糖。     

国内外蝗害治理技术现状与展望

本文首先概述了国内外蝗虫发生与为害的态势,总结了现阶段我国蝗虫发生与为害的主要特点:即农田飞蝗暴发频繁而且严重,草原土蝗的发生时常造成严重的经济损失,而且侵入城市干扰市民生活,我国与周边国家之间蝗虫过境迁移频繁,使用化学农药污染环境和农产品;分析了国内外蝗虫防治对策与技术的发展现状,重点介绍了应急防治和可持续治理对策、...     

Synthesis and turnover of cerebrosides and phosphatidylserine of myelin and microsomal fractions of adult and developing rat brain.

The synthesis and turnover of cerebrosides and phospholipids was followed in microsomal and myelin fractions of developing and adult rat brains after an intracerebral injection of [U-14C]serine. The kinetics of incorporation of radioactivity into microsomal and myelin cerebrosides indicate the possibility of a precursor-product relationship between cerebrosides of these membranes. The specific radioactivity of myelin cerebrosides was corrected for the deposition of newly formed cerebrosides in myelin. Multiphasic curves were obtained for the decline in specific radioactivity of myelin and microsomal cerebrosides, suggesting different cerebroside pools in these membranes. The half-life of the fast turning-over pool of cerebrosides of myelin was 7 and 22 days for the developing and adult rat brain respectively. The half-life of the slowly turning-over pool of myelin cerebrosides was about 145 days for both groups of animals. The half-life of the rapidly turning-over microsomal cerebrosides was calculated to be 20 and 40 h for the developing and adult animals respectively. The half-life of the intermediate and slowly turning-over microsomal cerebrosides was 11 and 60 days respectively, for both groups of animals. The amount of incorporation of radioactivity into microsomal cerebrosides from L-serine was greatly decreased in the adult animals, and greater amounts of the precursor were directed towards the synthesis of phosphatidylserine. In the developing animals, considerable amounts of cerebrosides were synthesized from L-serine, besides phosphatidylserine. The time-course of incorporation indicated that a precursor-product relationship exists between microsomal and myelin phosphatidylserine. The half-life of microsomal phosphatidylserine was calculated to be about 8 h for the fast turning-over pool in both groups of animals.     

Identification and composition of the tonsillar and anal enterococcal and streptococcal flora of dogs and cats

Enterococcus faecalis was the most frequently isolated enterococcal species from anal swabs and tonsils of dogs and cats, although in the anal samples from dogs Ent. hirae was found almost as often as Ent. faecalis. Most Ent.faecium strains from dog tonsils differed from those associated with humans and other animals in that they fermented sorbitol. Typical Ent. avium as well as atypical Ent. avium -like strains were seen in dogs, while the related species Ent. raffinosus was associated with cat tonsils. Enterococcus cecorum also occurred mainly in cats. Certain atypical strains, presumptively identified as Ent. cecorum , shared characteristics with Ent. columbae.
The most frequent streptococcal species in tonsils of cats and dogs were Streptococcus suis and Strep. canis. Streptococcus canis and Strep. bovis predominated in anal swabs. The canine Strep. suis differed from the common porcine strains in fermenting mannitol.
Forty-seven of the 288 isolates examined could not be identified or related to known species. The characteristics of two groups of these bacteria, provisionally called 'Ton 31 group' and 'O7 group' are described.     

Molecular characterisation of species and genotypes of Cryptosporidium and Giardia and assessment of zoonotic transmission

The molecular characterisation of species and genotypes of Cryptosporidium and Giardia is essential for accurately identifying organisms and assessing zoonotic transmission. Results of recent molecular epidemiological studies strongly suggest that zoonotic transmission plays an important role in cryptosporidiosis epidemiology. In such cases the most prevalent zoonotic species is Cryptosporidium parvum. Genotyping and subtyping data suggest that zoonotic transmission is not as prevalent in the epidemiology of giardiasis. Molecular characterisation of Cryptosporidium and Giardia is a relatively recent application that is evolving as new genes are found that increase the accuracy of identification while discovering a greater diversity of species and yet unnamed taxa within these two important genera. As molecular data accumulate, our understanding of the role of zoonotic transmission in epidemiology and clinical manifestations is becoming clearer.     

白术同源四倍体的诱导和鉴定及其与二倍体过氧化物酶的比较

以白术（Atractylodes macrooephala Koidz.）二倍体组培苗为材料,对其四倍体诱导方法进行研究,共获得45个白术同源四倍体株系,为优良株系的选育提供了材料。此外,还分析比较了其中8个白术四倍体株系与二倍体的过氧化物酶同工酶（POD）的酶谱差异,发现四倍体各株系过氧化物酶同工酶谱比二倍体的均多了Rf0.310的谱带,且总过氧化物酶比活力也发生了很大改变,对探讨白术四倍体优良株系的生理生化机理具有一定的参考价值。     

Kinetics and thermodynamics of peroxidase- and laccase-catalyzed oxidation of N-substituted phenothiazines and phenoxazines

N -substituted phenothiazines (PTs) and phenoxazines (POs) catalyzed by fungal Coprinus cinereus peroxidase and Polyporus pinsitus laccase were investigated at pH 4–10. In the case of peroxidase, an apparent bimolecular rate constant (expressed as k _cat/K _m) varied from 1 ×10⁷M⁻¹s⁻¹to 2.6×10⁸M⁻¹s⁻¹ at pH 7.0. The constants for PO oxidation were higher in comparison to PT. pH dependence revealed two or three ionizable groups with pK _a values of 4.9–5.7 and 7.7–9.7 that significantly affected the activity of peroxidase. Single-turnover experiments showed that the limiting step of PT oxidation was reduction of compound II and second-order rate constants were obtained which were consistent with the constants at steady-state conditions. Laccase-catalyzed PT and PO oxidation rates were lower; apparent bimolecular rate constants varied from 1.8×10⁵M⁻¹s⁻¹ to 2.0×10⁷M⁻¹s⁻¹ at pH 5.3. PO constants were higher in comparison to PT, as was the case with peroxidase. The dependence of the apparent bimolecular constants of compound II or copper type 1 reduction, in the case of peroxidase or laccase, respectively, was analyzed in the framework of the Marcus outer-sphere electron-transfer theory. Peroxidase-catalyzed reactions with PT, as well as PO, fitted the same hyperbolic dependence with a maximal oxidation rate of 1.6×10⁸M⁻¹s⁻¹ and a reorganization energy of 0.30 eV. The respective parameters for laccase were 5.0×10⁷M⁻¹s⁻¹ and 0.29 eV. Received: 20 September 1999 / Accepted: 24 February 2000