Adrenergic nerves and 5-hydroxytryptamine-containing cells in the pulmonary vasculature of the aquatic file snake Acrochordus granulatus

Summary The adrenergic innervation of the pulmonary vasculature of the file snake Acrochordus granulatus was examined by use of glyoxylic acid-induced fluorescence. Perivascular plexuses of blue-green fluorescent nerves are observed around the common pulmonary artery, the anterior and posterior pulmonary arteries, the arterioles leading to the gas exchange capillaries of the lung, the venules draining the lung, and the anterior and posterior pulmonary veins. Adrenergic nerves are also associated with the visceral smooth muscle of the lung septa and other tissues. Thus, adrenergic control of pulmonary blood flow may occur either at the common pulmonary artery or more regionally within the lung. Regional control of blood flow in the elongate lung of this snake may be important in matching pulmonary perfusion with the distribution of respiratory gas. Glyoxylic acid-histochemistry and immunohistochemistry revealed that populations of cells located in the common pulmonary artery contain the indoleamine 5-hydroxy-tryptamine. Many of the cells are intimately associated with varicose blue-green fluorescent nerves. It is proposed that the 5-hydroxytryptamine-containing cells may be involved in intravascular chemoreception.     

噬菌体RB69 DNA聚合酶的表达、分离纯化和其聚合反应的稳态动力学研究

噬菌体ＲＢ６９外切酶活性缺失的ＤＮＡ 聚合酶突变体（Ｄ２２２Ａ／Ｄ３２７Ａ）在大肠杆菌细胞中表达,表达量达细胞蛋白总量的６９％ ．表达后经ＤＥＡＥ－Ｓｅｐｈａｒｏｓｅ ＦａｓｔＦｌｏｗ , Ｓｏｕｒｃｅ ３０Ｑ 和ＨＴＰ三步分离纯化,纯度可达９９％ 以上．随后测定了该酶利用５种ｄＮＴＰ为底物进行聚合反应的酶促动力学常数（Ｋｍ 和Ｋｃａｔ）,结果表明该酶利用ｄＵＴＰ的能力与利用ｄＴＴＰ的能力相近,Ｋｍ （ｄＴＴＰ）和Ｋｍ（ｄＵＴＰ）均较高于其它３种脱氧核苷酸的Ｋｍ （ｄＡＴＰ, ｄＣＴＰ, ｄＧＴＰ）,推测其Ｋｍ 值的差异主要来源于Ｔ／Ｕ 碱基本身,而并非全部由ＧＣ碱基配对与ＡＴ碱基配对之间的氢键作用力的强弱差别所决定．     

Suivi pluriannuel du peuplement à Abra alba dans la partie méridionale de la Mer du Nord (région de Dunkerque-France)

The Abra alba community is considered as a faunistical unity well established on coastal areas of North Sea. This community shows, since several years, very important recruitments of certain species. Since 1978, recruitments of Abra alba, Tellina fabula, Phyllodoce (Anaïtides) mucosa, Lagis koreni or Lanice conchilega have been observed. However these demographic phenomena does not affect the structure of the community, which shows, through rank-frequency diagrams, the characteristic of a mature population, principally constituted of 7 species.An annual cycle study shows a succession of recruitments of several species. A correspondance factorial analysis was realised from grain size datas as well as abundances of 18 main species. This analysis shows an annual cycle which seems to be linked to the clay part. Maximal values of clay part appears in summer and minimal values at the end of winter or early springtime.The hydrological parameters studied, allowed to make the difference between external factors (continental contributions, phytoplanctonic activity etc...) and benthic activity.

     

阿托伐他汀早期干预对2型糖尿病合并高血压患者血脂及炎症因子水平的影响

目的:探讨早期阿托伐他汀钙片干预对2型糖尿病合并高血压患者血脂水平和炎症指标的影响。方法:选择2014年5月-2015年5月我院收治的2型糖尿病合并高血压患者130例,根据治疗方法不同,将患者分为研究组和对照组,每组各65例。对照组采取常规降压及降糖药物治疗,研究组在此基础上应用阿托伐他汀钙片。观察两组患者治疗前后血脂水平、高敏C-反应蛋白(hs-CRP)、白介素-6(IL-6)及白介素-18(IL-18)的变化情况。结果:治疗后,两组患者胆固醇(TC)及低密度脂蛋白胆固醇(LDL-C)水平均较治疗前降低,且研究组显著低于对照组,差异具有统计学意义(P0.05);两组患者治疗前后的甘油三脂(TG)及高密度脂蛋白胆固醇(HDL-C)水平比较,差异无统计学意义(P0.05);治疗后,两组患者hs-CRP、IL-6及IL-18水平均较治疗前降低,且研究组显著低于对照组,差异具有统计学意义(P0.05);两组不良反应的发生率比较,差异无统计学意义(P0.05)。结论:阿托伐他汀钙片可以有效改善2型糖尿病合并高血压患者的血脂水症,降低血清炎症因子的表达,值得临床推广应用。     

不同酿酒酵母菌株来源异麦芽糖酶IMA1的克隆、表达及表征

[目的]异麦芽糖酶IMA1在充分利用含有α-1,6-O-糖苷键的低聚糖中起着关键作用。[方法]在本研究中,对来自4株酿酒酵母菌株（包括3株嗜酸性菌株）来源的异麦芽糖酶IMA1进行克隆、表达、纯化和表征。[结果]研究发现,4种异麦芽糖酶IMA1表现出类似的pH和温度依赖性,但表现出不同的动力学参数和热稳定性。IMA1-A对α-MG（α-甲基葡糖苷）表现出最高的结合亲和力、转换数、催化效率和热稳定性。结构和序列分析表明,2个远离活性位点和底物结合位点的氨基酸的差异对异麦芽糖酶IMA1的动力学参数和热稳定性有重要影响。[结论]本研究结果对进一步研究异麦芽糖酶IMA1的结构-功能关系奠定了基础。     

Biological aspects of <Emphasis Type="Italic">Amblyomma brasiliense</Emphasis> (Acari: Ixodidae) under laboratory conditions

Although Amblyomma brasiliense Aragão 1908 has been reported as one of the most aggressive ticks to humans in Brazil, information about the biology of this tick species is virtually inexistent. This work reports data on the life cycle of A. brasiliense fed on rabbits and pigs and maintained in an incubator at 20°C, 90% RH and 12 h of light for off-host development. Tick yield of adult females fed on pigs and rabbits was 81.2% and 58.3%, respectively. Females fed on pigs had mean engorgement weight of 862.3 mg and egg mass of 208 mg, while females fed on rabbits had mean engorgement weight of 606.1 mg and egg mass of 160 mg; these values did not differ statistically between host species. Feeding period of female ticks fed on pigs (10 days) was significantly shorter than that on rabbits (17 days). Mean preoviposition period was slightly longer (35.9 days) for ticks fed on pigs than on rabbits (30 days). The minimum incubation period of eggs of ticks from both host species was similar and over 100 days. Egg production efficiency was low for females fed on both hosts (less than 30% and 20% for ticks from pigs and rabbits, respectively). More than 55% of larvae and 79% of nymphs fed on rabbits, set free inside the feeding chambers, engorged successfully. These ticks attained an engorgement weight of 1.3 and 18.2 mg, respectively, and fed for approximately 5 days. The minimum pre-molt period was 30 days for engorged larvae and over 44 days for nymphs. Molting success was low, less than 50% in the case of larvae and less than 20% for nymphs. Further studies are required to better determine the off-host requirements of this tick species.     

Chain-length dependence of the kinetics of the hyaluronan hydrolysis catalyzed by bovine testicular hyaluronidase

Hyaluronan (HA) has various biological functions that are strongly dependent on its chain length. In some cases, as in inflammation and angiogenesis, long and short chain-size HA effects are antagonistic. HA hydrolysis catalyzed by hyaluronidase (HAase) is believed to be involved in the control of the balance between longer and shorter HA chains. Our studies of native HA hydrolysis catalyzed by bovine testicular HAase have suggested that the kinetic parameters depend on the chain size. We thus used HA fragments with a molar mass ranging from 8x10(2) g mol(-1) to 2.5x10(5) g mol(-1) and native HA to study the influence of the chain length of HA on the kinetics of its HAase-catalyzed hydrolysis. The initial hydrolysis rate strongly varied with HA chain length. According to the Km and Vm/Km values, the ability of HA chains to form an efficient enzyme-substrate complex is maximum for HA molar masses ranging from 3x10(3) to 2x10(4) g mol(-1). Shorter HA chains seem to be too short to form a stable complex and longer HA chains encounter difficulties in forming a complex, probably because of steric hindrance. The hydrolysis Vm values strongly suggest that as the chain length decreases the HAase increasingly catalyses transglycosylation rather than hydrolysis. Finally, two HA chain populations, corresponding to HA chain molar masses lower and higher than approximately 2x10(4) g mol(-1), are identified and related to the bi-exponential character of the model we have previously proposed to fit the experimental points of the kinetic curves.     

Methane bubbles in surface peat cores: in situ measurements

The quantification of greenhouse gas sources and sinks is important to understanding the impact of climate change. Methane (CH₄) is a potent greenhouse gas, which, on a global scale, is released largely as a product of anaerobic microbial decomposition and predominantly from wetlands. A zone of intense CH₄ production just below the water table is thought to contribute significantly to the overall flux from peat bogs. We describe the use of membrane inlet quadrupole mass spectrometry (QMS) to confirm the existence of bubbles, their gaseous concentrations and their localization at a fine spatial resolution within intact peat cores. We use the distribution of the noble gas argon (Ar) and the distinct QMS responses to dissolved and gaseous (bubble) phases to identify trapped bubbles with a resolution of 0.6 mm. Bubbles with CH₄ concentrations of up to 20 kPa were widely distributed in the upper 300 mm of the cores with ～11% of all profiles comprising bubbles. The dissolved concentrations responsible for the bubbles were on average 83±80 μm , indicating lower concentrations relative to other QMS studies. We suggest that if the distinction between dissolved and gaseous phases is not made in studies of CH₄ within peat profiles then the prominence of bubbles is likely to result in overestimates of dissolved CH₄ concentrations. Fluxes of CH₄ from peat as a result of drawdown or other perturbation are likely to be large, rapid and short lived because of bubble burst, and also larger than from peat without bubbles. We suggest that the dynamics of fluxes need to be modelled taking into account both gaseous and dissolved phases. Estimates of potential fluxes that assume CH₄ is dissolved are likely to overestimate fluxes if the gaseous phase has not been taken into account.     

我国主粮作物的化学农药用量及其温室气体排放估算

现代农业中化学农药在提高作物产量中发挥着重要的作用,但是我国普遍存在过量用药现象,导致环境污染和危害食品安全.基于2012年的全国性农户问卷调查,本研究分析了2011年我国水稻、小麦和玉米使用农药现状,并估算了它们的温室气体排放.结果表明: 这3种作物至少使用了54种杀虫剂、24种杀菌剂和50种除草剂,其中32%的水稻种植农户使用了生物农药.全国3种作物使用了30.8 kt杀虫剂、16.5 kt杀菌剂和58.3 kt除草剂,它们的温室气体排放总量为1.5 Tg Ce,杀虫剂、杀菌剂和除草剂的排放分别占23.8%、16.9%和59.3%.南方区的农药用量占全国用量的51%;全国水稻、小麦和玉米的单位产量农药用量分别是0.22、0.18和0.24 g·kg^-1粮食,3种作物用药总量分别为44.4、21.4和39.7 kt,温室气体排放分别为665.5、250.1和547.5 Gg Ce;在不同农药种类中,有机磷类杀虫剂占我国所用杀虫剂总量的69%,苯丙咪唑类、有机磷类、唑类和有机硫类等杀菌剂占杀菌剂总量的87%,酰胺类、有机杂环类和有机磷类等除草剂占除草剂总量的85%.因此,减少农药用量,对于我国粮食安全和环境安全及减少农业温室气体排放都具有重要意义.