应用雪尿分析技术评价不同类型栖息地中狍冬季的营养状况

雪尿分析技术是北方冬季有蹄类种群营养状况评价的可靠性指数。本文通过对兴隆镇小东林场和三江自然保护区1999 及2000 年冬季狍50 个雪尿、尿液样本采集及分析, 用以评价在不同类型的栖息地中狍冬季的营养状况, 结果表明: 雪尿分析可以评价狍冬季的营养状况及其变化; 雪尿中较低的尿素氮与肌酸酐的比率表明两地区狍基本上处于营养不良早期阶段, 反映了食物资源可利用性低、食物营养质量低造成外源蛋白质和能量摄入不足, 而使狍大量消耗体脂肪, 并通过对尿液化学成分的重吸收利用而保持其在尿液中排出量最低, 使机体内源蛋白质分解代谢处于较低状态; 三江1999 年冬季狍营养状况相对较差, 而2000 年情况较好; 幼体及亚成体处于营养不良中期阶段。
     

木荷属和柃木属植物的嘌呤代谢及嘌呤碱合成研究

以［8-¹⁴C］标记的腺嘌呤和黄嘌呤为底物,对两种可以合成少量咖啡碱和茶叶碱的木荷属和柃木属植物（Schima mertensiana,Eurya japonica）叶片的嘌呤代谢进行了检测研究。发现木荷属和柃木属植物中嘌呤代谢相似,¹⁴C标记的腺嘌呤可以整合到嘌呤核苷酸、RNA、酰脲（包括尿囊素和尿囊酸）、二氧化碳中。经过24 h培养,在叶片吸收的放射能中,仅有6%～7%用于甲基黄嘌呤类化合物的合成（3-甲基黄嘌呤、7-甲基黄嘌呤核苷、7-甲基黄嘌呤、茶叶碱）。和其他植物一样,绝大多数¹⁴C标记的黄嘌呤整合到嘌呤的分解代谢物中（二氧化碳和酰脲）,少量的放射能分布在3-甲基黄嘌呤及茶叶碱中。根据结果可以推断木荷属和柃木属植物具有N-甲基转移酶活性,可以用来合成咖啡碱和茶叶碱,相对于茶树而言,活性不高。综上,本文对木荷属和柃木属植物的嘌呤代谢以及嘌呤碱合成进行了研究。     

降血尿酸益生菌株的筛选和降血尿酸机理的探索

【背景】高尿酸血症是人体内血尿酸含量显著高于正常水平的代谢性疾病,利用益生菌降解食物中外源性嘌呤类成分成为治疗高尿酸血症的新方法。【目的】筛选具有降低血尿酸作用的益生菌,并探索其作用机制。【方法】利用HPLC从多株实验菌株中筛选降解核苷酸(腺苷酸、鸟苷酸)、核苷(腺苷、鸟苷)、嘌呤(黄嘌呤、次黄嘌呤、鸟嘌呤)、尿酸能力最强的益生菌。首次利用质谱定性与定量检测菌株降解核苷与核苷酸过程中代谢物的变化,结合菌株对高尿酸血症模型大鼠血尿酸水平的影响,初步探索其降低血尿酸的机理。【结果】首次筛选出具有较强降解核苷酸与核苷能力的干酪乳杆菌ZM15(CGMCC No.13980),高尿酸血症模型大鼠验证其具有降低血尿酸的作用。结果显示菌株ZM15在胞内降解核苷酸、核苷后,胞内、外均测到鸟嘌呤、黄嘌呤、次黄嘌呤,且胞内3种嘌呤含量显著高于正常菌体内含量(P0.01),尿酸和尿囊素在胞内、外均未发现。【结论】干酪乳杆菌ZM15具有较强的降解核苷酸、核苷的能力,推测其主要通过与肠道上皮细胞竞争吸收核苷酸与核苷,从而对高尿酸血症模型大鼠具有降血尿酸作用。     

尿淀粉酶检测对急性胰腺炎临床诊断的意义

目的:探讨尿淀粉酶检测结果对急性胰腺炎临床诊断的意义。方法:选取2011年6月至2012年7月在我院接受治疗的急性胰腺炎患者50例定义为AP组,选取非胰腺炎急腹症患者50例定义为NP组,选取健康人群50例定义为HS组。分别检测三组患者的血淀粉酶(SAMY),尿淀粉酶(UAMY),尿肌酐(UCR)及尿淀粉酶与尿肌酐的比值(UACR),整理并分析检测结果。结果:急性胰腺炎组和非胰腺炎急腹症组的患者的血淀粉酶、尿淀粉酶、尿淀粉酶与尿肌酐的比值均高于健康对照组,组间比较差异显著(P0.05);非胰腺炎急腹症组与健康对照组的尿淀粉酶和尿肌酐比值相比差异不明显(P0.05)。急性胰腺炎组的淀粉酶和尿肌酐比值的敏感性为93.41%,特异性为93%;血清淀粉酶的敏感性为86.7%,特异性为92.2%,均高于临床诊断指标的常用值。结论:急性胰腺炎尿液与尿肌酐比值的测定是早前急性胰腺炎诊断和治疗的重要检测指标。     

应用骨髓脂肪指数评价狍冬季体状况

目前,有蹄类体状况的评价方法主要有整体脂肪指数(Wholebodyfat,WBF)[1,2]、肾脂肪指数(Kidneyfatindex,KFI)[3～10]、骨髓脂肪指数(Mar rowfatindex,MFI)[11～21]、尿液及雪尿分析技术(Urineanalysis)[22,23]和瘤胃粘膜表面扩张系数(Surfaceenlargementfactor,SEF)[24],可直接或间接地反映体脂肪的蓄积情况,并在一定程度上反映有蹄类所处环境的食物质量和营养压力。鹿科反刍动物对脂肪的蓄积和消耗具有一定的顺序,可视脂肪最先蓄积在心脏的基部及冠状沟附近,其次为心包膜、网膜、肾周围及皮下背部及腹部,而脂肪被消耗的顺序依次…     

尿囊素在肉苁蓉属植物分类中的应用

以尿囊素作为鉴别试剂,对肉苁蓉属中的管花肉苁蓉与同属的其它品种植物进行鉴别.采用HPLC法,在以下色谱条件下(Hypersil ODS-2色谱柱4.6 mm×250 mm,5 μm,流动相为乙腈-7.5%二氧六环水溶液1:99,流速0.5 mL/min,柱温25℃,检测波长224 nm)绘制肉苁蓉属植物不同品种的色谱图.在盐生肉苁蓉或荒漠肉苁蓉的HPLC色谱图中,与对照品尿囊素色谱峰相应的位置处,显示保留时间相同的色谱峰,而在管花肉苁蓉供试品的HPLC色谱图中,无尿囊素色谱峰,提示不含尿囊素的肉苁蓉为管花肉苁蓉.该鉴别方法简便、灵敏,能快速、准确地将管花肉苁蓉与同属其它品种植物鉴别开来.     

HPLC法测定九节菖蒲中琥珀酸含量

目的:建立九节菖蒲中琥珀酸含量的HPLC测定法。方法:采用Kromasil C18色谱柱(150 mm×4.6 mm,5μm);甲醇-0.02mol/L KH2PO4缓冲液(7:93)(pH 2.5)为流动相;流速0.5 mL/min;柱温为30℃;检测波长为214 nm。结果:琥珀酸在4～48μg范围内具有良好的线性关系,平均加样回收率为99.15%。九节菖蒲样品中的琥珀酸含量,以干燥品计为0.200%～0.318%。结论:该方法可行,重复性好,可用于九节菖蒲中琥珀酸含量的测定。     

生物催化过程中色氨酸与色氨酰胺的测定

采用高效液相色谱法来定量测定生物催化过程中的色氨酸及色氨酰胺。使用戴安C18柱,乙腈与10mmol.L-1的KH2PO4为流动相,梯度洗脱分析。在此条件下进行色谱分离,两样品的分离度达到9.36。并且成功的以美国Astec公司生产的CHIROBIOTIC手性色谱柱为固定相,乙腈与0.5%的冰醋酸为流动相,对产物色氨酸的对映体选择性进行了检测分析。     

慢性心力衰竭患者营养状况的评估

目的:了解慢性心力衰竭患者的营养状况,并对常用的营养检测指标进行评估。方法:对48例心功能Ⅲ~Ⅳ级(NYHA分级)的慢性心力衰竭患者进行了营养状况的评估,并进行分组(营养正常组28例,营养不良组20例),同时对营养不良的常用检测指标进行评价。结果:本研究营养不良的发生率为41.7%,除运铁蛋白外,体重、中上臂肌围、三头肌皮褶厚度(TSF)、白蛋白、总淋巴细胞计数(TLC)、肌酐/身高指数在两组间差异均有统计学意义(P0.05~0.001)。结论:严重慢性心力衰竭患者营养不良的发生率高,肌酐/身高指数、中上臂肌围、TSF、白蛋白及TLC五项指标在用于慢性心衰患者的营养评估时具重要的参考意义,其敏感性和特异性均大于50%。     

黄瓜无菌苗雌花诱导体系的建立

研究Spm和IAA对无菌黄瓜苗雌花诱导的协同作用,及不同外植体、培养基中琼脂含量和KH2PO4含量对雌花诱导的影响,由此建立了有效的雌花诱导体系。黄瓜去根苗接种在MS培养基上,单独添加Spm、IAA时的雌花诱导率、雌花数偏低或为0,同时添加12mg.L-1Spm与0.01mg.L-1IAA时达21%、29枚,对照组未见雌花,说明Spm和IAA对雌花诱导的协同作用显著。实验证明,在全苗、去根苗、去根去顶苗、顶芽四种外植体中,及在0.5%～0.9%琼脂含量和1.0～2.0mmol.L-1KH2PO4含量的培养条件下,采用0.7%琼脂含量和1.75mmol.L-1KH2PO4含量培养黄瓜去根去顶苗的雌花诱导效果最好,其诱导率和雌花数分别达46%、54枚。     

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