无症状吸烟者的肺功能改变情况分析

目的:探讨烟龄≥15年,日吸烟量≥15支的无症状男性吸烟者的肺功能改变情况。方法:选择男性无症状吸烟者190人及非吸烟者180人,进行肺功能测定,并比较两组人群的肺功能改变情况。结果:吸烟组与非吸烟组比较,肺活量(VC)、用力肺活量(FVC)、第1秒用力呼气容积(FEV1)、Tiffeneau 1秒率(FEV1/VC)结果改变不明显,而Gaensler 1秒率(FEV1/FVC)、最大分钟通气量(MVV)、用力呼气50%肺活量的呼气流量(FEF50%)、用力呼气75%肺活量的呼气流量(FEF75%)、呼出25%～75%肺活量时的平均流量(FEF25%～75%)、肺一氧化碳弥散量(DLCO)结果均有显著降低,有统计学意义。结论:通过对无症状吸烟人群肺功能测定结果进行分析。发现有些吸烟者虽无临床症状,但已经出现了小气道及肺弥散功能的损伤,提醒吸烟者应早期戒烟,关爱自身健康,净化生存环境,提高生活质量。     

Anthropoecological investigations in Central Asia

The results of anthropoecological investigations in Central Asia are described. From 1976 to 1991 about 6,000 individuals of both sexes were examined. 2,500 of them were children from 7 to 17 years. The program included the study of body build, metabolic rates, genetic markers and demographic structures. Different groups of Tuvins, Khakass, Mountain and Abakan Shortsys, Altai-kijis, Telengits, Teleuts, Kazakhs, and several groups of Mongols and Khotons were studied. It was shown that some patterns of body build and physiological traits of native populations of Central Asia partly reflect the influence of the geographical environment. The differences observed between various populations of the region may be explained by ecological reasons and not only by ethnic differentiation.     

MPP3 is recruited to the MPP5 protein scaffold at the retinal outer limiting membrane

Mutations in the human Crumbs homologue 1 (CRB1) gene are a frequent cause of various forms of retinitis pigmentosa. The CRB1-membrane-associated palmitoylated protein (MPP)5 protein complex is thought to organize an intracellular protein scaffold in the retina that is involved in maintenance of photoreceptor-Müller glia cell adhesion. This study focused on the binding characteristics and subcellular localization of MPP3, a novel member of the MPP5 protein scaffold at the outer limiting membrane (OLM), and of the DLG1 protein scaffold at the outer plexiform layer of the retina. MPP3 localized at the photoreceptor synapse and at the subapical region adjacent to adherens junctions at the OLM. Localization studies in human retinae revealed that MPP3 colocalized with MPP5 and CRB1 at the subapical region. MPP3 and MPP4 colocalized with DLG1 at the outer plexiform layer. Mouse Dlg1 formed separate complexes with Mpp3 and Mpp4 in vivo. These data implicate a role for MPP3 in photoreceptor polarity and, by association with MPP5, pinpoint MPP3 as a functional candidate gene for inherited retinopathies. The separate Mpp3/Dlg1 and Mpp4/Dlg1 complexes at the outer plexiform layer point towards additional yet unrecognized functions of these membrane associated guanylate kinase proteins.     

棉叶中棉酚的快速提取与测定方法研究

棉酚(G)及其相关物甲氧基半棉酚(DHG)、半棉酚酮(HGQ)、半棉酚(HG)、杀实夜蛾素(H1-4)等是棉花中重要的抗虫性萜烯类次生物质.利用高效液相色谱法(HPLC)对棉酚及其相关物进行了分离,测定了棉叶中的棉酚含量,讨论了不同的提取方法和测定条件对结果的影响,给出了一套简便、快速的分析测试方法,同时与紫外-可见分光光度法(苯胺法)的结果进行了对比,认为对于棉花的抗虫性的研究来说,HPLC是比较适宜的方法.     

Cloning, expression and processing of the CP2 neuropeptide precursor of Aplysia

The cDNA sequence encoding the CP2 neuropeptide precursor is identified and encodes a single copy of the neuropeptide that is flanked by appropriate processing sites. The distribution of the CP2 precursor mRNA is described and matches the CP2-like immunoreactivity described previously. Single cell RT-PCR independently confirms the presence of CP2 precursor mRNA in selected neurons. MALDI-TOF MS is used to identify additional peptides derived from the CP2 precursor in neuronal somata and nerves, suggesting that the CP2 precursor may give rise to additional bioactive neuropeptides.     

嫁接对梅花耐盐性的影响

以盆栽一年生‘丰后’梅自根苗、山杏为砧木的‘丰后’梅嫁接苗以及山杏自根苗为试材,设置土壤NaCl含量分别为0(CK)、0.3%、0.6%、0.9%、1.2%和1.5%的盐胁迫处理,观测3种植物盐害情况及其叶片细胞膜透性、抗氧化酶活性、有机渗透调节物质含量的变化,并应用隶属函数值法对各盐浓度处理下3种材料叶片的生理指标进行综合评定,以明确它们的耐盐能力,为梅花向盐渍土分布较广的北方地区推广应用,以及梅花繁殖方法及梅花砧木的选择提供理论依据。结果表明:(1)随着土壤中NaCl含量的递增,‘丰后’梅自根苗、‘丰后’梅嫁接苗及山杏的盐害指数和盐害率不断增大,三者盐害指数在50%时土壤NaCl含量分别是0.545%、0.695%和0.705%,表明3种材料耐盐性由强到弱依次为山杏‘丰后’梅嫁接苗‘丰后’梅自根苗。(2)随着盐胁迫时间的延长,3种植物苗木叶片相对电导率(RC)和丙二醛(MDA)含量整体呈先上升后下降的趋势;‘丰后’梅自根苗过氧化物酶(POD)活性总体呈上升趋势,‘丰后’梅嫁接苗和山杏总体均呈现上升趋势,但个别浓度呈先上升后下降趋势;‘丰后’梅自根苗可溶性糖(SS)含量整体呈现上升趋势,‘丰后’梅嫁接苗和山杏均总体呈先下降后上升趋势,但个别较高浓度呈先上升后下降趋势。(3)隶属函数值法对盐抗性的综合评定结果为:山杏‘丰后’梅嫁接苗‘丰后’梅自根苗,综合评定结果与3种材料的盐害指数分析结果一致。研究发现,3种植物叶片所受到盐伤害的程度随NaCl胁迫浓度提高而加深,但植株叶片能对中低盐浓度处理产生一定的适应性;以耐盐性较强的山杏作为嫁接砧木后,‘丰后’梅嫁接苗比其自根苗的耐盐性增强,证明嫁接对梅花耐盐性具有一定的促进作用。     

盐节木同化枝的腋芽丛生与快速繁殖

本文通过同化枝腋芽丛生方式建立了盐生植物盐节木的快速繁殖体系。以在MS附加200 mmol·L-1 Na Cl的培养基上无菌种子萌发、生长共计4~5个月、高约3~4 cm的盐节木小苗为材料,从上截取0.5 cm长的同化枝小段为外植体,培养在MS附加不同浓度的6-BA与NAA的培养基中。结果表明:同化枝腋芽诱导与增殖最佳培养基均为MS+0.05 mg·L-1 6-BA+1mg·L-1 NAA或MS+1 mg·L-1 6-BA,初代培养30 d后,腋芽诱导率达97.5%,平均芽增殖系数为2.50;继代增殖培养时,将同化枝切成1 cm长的小段芽增殖系数提高到4.92;一次性芽苗伸长与生根培养基为MS+0.05 mg·L-1 IBA,生根率达99%;小苗经炼苗后移栽到沙子、营养土和蛭石体积比为1:1:1的基质中,成活率可达91%。     

The steady-state internal redox state (NADH/NAD) reflects the external redox state and is correlated with catabolic adaptation in Escherichia coli

Escherichia coli MC4100 was grown in anaerobic glucose-limited chemostat cultures, either in the presence of an electron acceptor (fumarate, nitrate, or oxygen) or fully fermentatively. The steady-state NADH/NAD ratio depended on the nature of the electron acceptor. Anaerobically, the ratio was highest, and it decreased progressively with increasing midpoint potential of the electron acceptor. Similarly, decreasing the dissolved oxygen tension resulted in an increased NADH/NAD ratio. As pyruvate catabolism is a major switch point between fermentative and respiratory behavior, the fluxes through the different pyruvate-consuming enzymes were calculated. Although pyruvate formate lyase (PFL) is inactivated by oxygen, it was inferred that the in vivo activity of the enzyme occurred at low dissolved oxygen tensions (DOT 相似文献   

Optimization of glycosidases production by Pseudoalteromonas issachenkonii KMM 3549(T)

AIMS: The present work aimed to design an optimized medium to yield a higher production of glycosides by Pseudoalteromonas issachenkonii KMM 3549(T). METHODS AND RESULTS: Higher levels of fucoidan hydrolase, alginase, laminaranase and b-N-acetylglucosaminidase production were obtained with peptone concentrations ranging from 2.5 g l(-1) to 10 g l(-1), while the presence of both yeast extract and glucose did not affect enzyme production. The activity of fucoidan hydrolase and laminaranase increased up to 4.83 microM h(-1) mg(-1) and 19.23 microM h(-1) mg(-1) protein, respectively, in growth media containing xylose (1.0 g l(-1)), laminarin (0.5 g l(-1)) or alginate (0.5 g l(-1)), and production of b-N-acetylglucosaminidase substantially increased in the presence of fucoidan (0.5 g l(-1)) or galactose (1 g l(-1)). All polysaccharides tested in concentrations of 0.5 g l(-1) fucoidan and 0.2 g l(-1) fucose induced production of alginase (up to 5.06 microM h(-1) mg-1 protein). CONCLUSIONS: The production of glycosidases is not only stimulated by the presence of algal polysaccharides, but may also be stimulated by monosaccharides (e.g. xylose). SIGNIFICANCE AND IMPACT OF THE STUDY: The production of glycosidases by Pseudoalteromonas issachenkonii KMM 3549(T) was significantly improved by using a simple nutrient medium containing peptone (2.5 g l(-1)) and xylose (5.0 g l(-1)) in 100% natural seawater.