牛创伤性心包炎临床病例心电图分析

本文报告最近6年收集的21例牛创伤性心包炎临床病例心电图观测结果。这些病例主要表现窦性心动过速,一例为异位心律。心率x±s=102±19次/分。全部时间间隔随心率增加而缩短。6个肢体导联R波低电压(Rx±s=0.18mV±0.0416)。T波低平,伴有或不伴S-T段移位。经临床检查、血液常规检验、胸部X线透视和拍片、超声波探查及尸体剖检印证,诊断正确可靠。因此认为上述心电图特征有助于牛创伤性心包炎的临床诊断.试验过程中也发现,渗出性胸膜炎可出现R波电压过低现象,应在临床诊断中注意鉴別。     

玉米幼芽提取物对垂体后叶素致家兔心肌缺血的保护作用

采用耳缘静脉注射垂体后叶素(pituitrin, Pit)诱发家兔急性心肌缺血,观察Ⅱ导联心电图心率、S-T段位移及T波波幅;心肌酶(谷草转氨酶、乳酸脱氢酶、肌酸激酶);心肌组织中谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)活性和脂质过氧化物丙二醛(MDA)含量的变化.结果显示,玉米幼芽提取物可减轻垂体后叶素诱发的家兔心电图缺血性改变(心率变缓、S-T段抬高、T波高耸),抑制血清中AST、LDH、CK活性的升高,并可增加缺血心肌组织中GSH-Px和SOD活性,抑制MDA含量升高.结果表明,玉米幼芽提取物对垂体后叶素致家兔心肌缺血有一定的保护作用.     

Ring currents in icosahedral c60

A new formulation of the current within the London approximation allows the calculation of ring currents in topologically complex molecules. Application of this theory to C(60) demonstrates the existence of remarkable pi electron ring currents. Paramagnetic currents, in size comparable to the ones in benzene, flow within the pentagons, whereas weaker diamagnetic currents flow all around the C.(60) molecule. The overall vanishing ring-current magnetic susceptibility results from a cancellation of diamagnetic and paramagnetic contributions. The presence of ring currents significantly affects chemical shifts as measured in nuclear magnetic resonance experiments. In contrast to the magnetic susceptibility, which is a property of the molecule as a whole, chemical shifts are sensitive to the local magnetic field and the effect of ring currents does not vanish.     

PLAGUE TOXIN: ITS EFFECT IN VITRO AND IN VIVO

The murine toxin of Pasteurella pestis inhibited the respiration of heart mitochondria from the rat and the mouse but had little or no effect on the respiration of mitochondria from the rabbit, chimpanzee, dog, and monkey. Alterations occurred in tile S-T segments of the electrocardiogramus recorded corded from rats injected with (1/4) to 10 LD(50) of toxin, but not in those from rats dying of hemorrhagic shock, hypoxia, intoxication with glucose, or Escherichia coli endotoxin. No abnormalities were observed in electrocardiograms from rabbits injected with large amounts of toxin.     

Rapid beta-adrenergic modulation of cardiac calcium channel currents by a fast G protein pathway

beta-Adrenergic agonists activate the G protein, Gs, which stimulates cardiac calcium currents by both cytoplasmic, indirect and membrane-delimited, direct pathways. To test whether beta-adrenergic agonists might use both pathways in the heart, isoproterenol was rapidly applied to cardiac myocytes, resulting in a biphasic increase in cardiac calcium channel currents that had time constants of 150 milliseconds and 36 seconds. beta-Adrenergic antagonists of a G protein inhibitor blocked both the fast and slow responses, whereas the adenylyl cyclase activator forskolin produced only the slow response. The presence of a fast pathway in the heart can explain what the slow pathway cannot account for: the ability of cardiac sympathetic nerves to change heart rate within a single beat.     

水合氯醛和静松灵对家兔心电图的影响

水合氯醛和静松灵麻醉后测定家兔心电图,将其与正常状态下的心电图进行分析和对比。结果表明,注射水合氯醛后心率加快,心电图中S-T段消失,T-P段上升,部分家兔出现角弓反张、呼吸困难,其安全性差;注射静松灵对心电图的影响较大,心率明显减慢,出现锯齿型F波和冠状T波,T波电压升高到0.118~0.231 mV,Ⅱ、Ⅲ、aVF导联的Q波消失。     

Interdecadal variation in an antarctic sponge and its predators from oceanographic climate shifts

During the 1960s there was extensive formation of anchor ice to depths of 30 meters at McMurdo Station, Antarctica. During this period the sponge Homaxinella balfourensis was rare, as were its predators in that depth zone. Most of the existing sponges were killed by anchor ice. During the 1970s, anchor ice formation was reduced, and there was a massive recruitment of Homaxinella, which covered as much as 80 percent of the substrata in that zone. Many predators appeared but did not control the sponge population, and it continued to grow through that decade. The early 1980s were characterized by ice formation and almost all of the Homaxinella were eliminated, leaving an order of magnitude more predators in that zone. The interdecadal increases in anchor ice probably result from local upwelling of extremely cold deep water, possibly in response to shifts in the strengths of regional currents.     

Cardiac change as a function of attention to and awareness of continuous verbal text

A 17-minute passage taken from a patient's talking in a psychoanalytic interview was played to 40 subjects, including trained therapists, therapists in training, and inexperienced undergraduates. Subjects were alerted to the organizing theme (termination of the patient's treatment) and asked to attend to direct and indirect references to this theme. Tonic heart rate, averaged over 30-second periods, was lower when clues were present on the tape than during control periods when clues were not present. Profiles of phasic heart rate were drawn for 11-second periods that overlapped the end of each clue and control passage. Profiles associated with clues were significantly lower than profiles for control passages; profiles for recalled and recognized clues showed a wave form distinct from that of profiles associated with unrecognized clues.     

抚育间伐对白桦天然次生林生长及林下植物多样性的影响

采用样地调查的方法,对白桦次生林抚育间伐(F-T:平地,强度间伐;S-T:坡地,弱度间伐)3 a后林分生长、径级结构和林下植物多样性进行研究。结果表明,抚育后乔木群落和白桦种群的平均胸径、平均冠幅有增加趋势,但不显著（P>0.05）,树高无显著变化。对位于平地的林分进行强度间伐后,乔木群落大径组(25 cm≤DBH＜37 cm)比例提高8%,白桦种群大径组比例提高5%。对位于坡地的林分进行弱度间伐后,乔木群落大径组和白桦种群大径组比例分别提高5%和23%。抚育后,林下灌木层物种丰富度降低,F-T、S-T灌木层物种数分别比各自对照降低了42.9%和52.9%,草本层物种丰富度升高,F-T、S-T分别增加了22.2%和71.4%。珍珠梅、白花碎米荠、猴腿蹄盖蕨、蚊子草和宽叶薹草的重要值均增加,红松、东北茶藨子、花楷槭,刺玫蔷薇、细叶苔草和羽节蕨的重要值均降低。抚育后灌木层Simpson多样性指数、Shannon-Wiener多样性指数和Pielou均匀度指数均降低,草本层各指数均升高。综上,从短期(3 a)效果看,抚育间伐有促进白桦次生林径向生长和提高大径组比例的趋势,利于林下草本植物的更新和多样性的提高,而灌木层更新受阻,多样性降低。     

豆类丝核菌次级代谢产物对阿霉素所致小鼠骨髓和心肌毒性的保护作用研究

探讨了豆类丝核菌次级代谢产物对阿霉素(ADR)所致小鼠骨髓抑制及心肌损伤的保护作用。建立小白鼠骨髓抑制和心肌损伤模型。检测血常规,描记心电图,测定血清中肌酸激酶(CK)、乳酸脱氢酶(LDH)活性,心肌组织中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。心肌组织石蜡切片,HE染色,光镜观察。结果表明阿霉素4 mg.kg-1可致小白鼠骨髓抑制和心肌损伤。豆类丝核菌次级代谢产物可抑制阿霉素引起的白细胞数、红细胞数、血红蛋白量的减少;使心率加快,心电图Q波振幅减小,QRS波时间缩短和S-T段回升;降低血清CK、LDH活力,增强心肌SOD活力,降低MDA含量,减轻心肌组织损伤。豆类丝核菌次级代谢产物对ADR所致小白鼠骨髓和心肌毒性有一定的保护作用。     

CP基因3'端短片段介导的对马铃薯Y病毒的抗性

【目的】探明马铃薯Y病毒脉坏死株系（PVYN）CP基因3′端序列短片段的不同结构转基因诱导转基因植物产生RNA介导抗性的有效性。【方法】以PVYN的CP基因cDNA 3′端202 bp片段构建非翻译的正向重复和反向重复结构的植物表达载体转化烟草。【结果】攻毒试验表明前者没有一例转基因植株表现为抗病，而转化反向重复结构的转基因植株82.8%表现近似免疫的高度抗病型，Southern印迹杂交证明目的基因已整合到烟草基因组，Northern印迹杂交结果显示反向重复结构转基因植物的抗病性与RNA的表达量呈现负相关。【结论】抗病性是RNA介导的病毒抗性。3′端短片段诱导产生的转基因抗病株比例比5′端短片段诱导产生的高。     

A chromosome 21 critical region does not cause specific Down syndrome phenotypes

The "Down syndrome critical region" (DSCR) is a chromosome 21 segment purported to contain genes responsible for many features of Down syndrome (DS), including craniofacial dysmorphology. We used chromosome engineering to create mice that were trisomic or monosomic for only the mouse chromosome segment orthologous to the DSCR and assessed dysmorphologies of the craniofacial skeleton that show direct parallels with DS in mice with a larger segmental trisomy. The DSCR genes were not sufficient and were largely not necessary to produce the facial phenotype. These results refute specific predictions of the prevailing hypothesis of gene action in DS.     

4种化合物对离体培养二色胡枝子组织分化的影响(英文)

以BADH基因为选择标记基因进行遗传转化最适宜的选择剂、抑菌剂种类和浓度,通过不同浓度NaCl、甜菜碱醛、PEG及甜菜碱醛和NaCl的不同组合等进行胡枝子子叶节分化,茎段增殖以及生根培养,发现NaCl和甜菜碱醛都能抑制二色胡枝子的子叶节分化、茎段增殖和生根,可作为遗传转化中的选择剂。培养基中添加0.8 g/L NaCl就能完全抑制二色胡枝子子叶节和茎段增殖,可作为遗传转化过程中子叶节和茎段增殖阶段的选择剂浓度。培养基中添加0.5 g/L NaCl能抑制生根,适合作为离体培养生根阶段的选择剂浓度。随着培养基中甜菜碱醛浓度的增加,子叶节分化能力下降,当甜菜碱醛达到1.5 g/L时子叶节不再分化,这可作为以甜菜碱醛为选择剂时子叶节分化阶段的最佳筛选。培养基中同时添加NaCl和甜菜碱醛时,NaCl 0.7 g/L+甜菜碱醛0.3 g/L就抑制了离体培养过程中茎段增殖和生根,比较适合二色胡枝子离体培养时茎段增殖和生根的筛选浓度。对头孢霉素的研究发现:培养基中添加200~300 mg/L头孢霉素对离体培养的二色胡枝子子叶节分化影响不大,培养基中添加100mg/L的头孢霉素对离体培养的二色胡枝子茎段增殖和生根无显著影响。     

4种化合物对离体培养二色胡枝子组织分化的影响

以BADH基因为选择标记基因进行遗传转化最适宜的选择剂、抑菌剂种类和浓度,通过不同浓度NaCl、甜菜碱醛、PEG及甜菜碱醛和NaCl的不同组合等进行胡枝子子叶节分化,茎段增殖以及生根培养,发现NaCl和甜菜碱醛都能抑制二色胡枝子的子叶节分化、茎段增殖和生根,可作为遗传转化中的选择剂。培养基中添加0.8g/L NaCl就能完全抑制二色胡枝子子叶节和茎段增殖,可作为遗传转化过程中子叶节和茎段增殖阶段的选择剂浓度。培养基中添加0.5g/L NaCl能抑制生根,适合作为离体培养生根阶段的选择剂浓度。随着培养基中甜菜碱醛浓度的增加,子叶节分化能力下降,当甜菜碱醛达到1.5g/L时子叶节不再分化,这可作为以甜菜碱醛为选择剂时子叶节分化阶段的最佳筛选。培养基中同时添加NaCl和甜菜碱醛时,NaCl 0.7g/L+甜菜碱醛0.3g/L就抑制了离体培养过程中茎段增殖和生根,比较适合二色胡枝子离体培养时茎段增殖和生根的筛选浓度。对头孢霉素的研究发现:培养基中添加200~300mg/L头孢霉素对离体培养的二色胡枝子子叶节分化影响不大,培养基中添加100mg/L的头孢霉素对离体培养的二色胡枝子茎段增殖和生根无显著影响。     

不同培养系统和传代方法对昆明白小鼠原始生殖细胞分离培养的影响

[目的]寻求适合昆明白小鼠EG细胞的培养系统和传代方法。[方法]常规方法从昆明白小鼠原始生殖细胞中分离EG细胞,用不同培养系统(EG细胞基础培养液,RH-CM,EG细胞基础培养液+MEF)及不同传代方法(机械法,酶消化法,连同饲养层消化法),研究对昆明白小鼠EG细胞分离克隆的影响。[结果]以RH-CM作为培养基效果最好,RH-CM能够更好地促进EG细胞贴壁增殖和集落的形成,有效地维持EG细胞未分化状态;酶消化法和连同饲养层消化法均能获得较高的克隆形成率。[结论]RH-CM和连同饲养层消化法可分别作为昆明白小鼠EG细胞的培养系统和传代方法。     

急性脑梗塞与血清白细胞介素—6关系的初步探讨

用双抗体夹心ＥＬＩＳＡ法对４６例急性脑梗塞患者血清ＩＬ－６含量作了检测，结果显示：脑梗塞急性期和恢复期两组均明显高于健康人对照组（Ｐ＜０．００５，Ｐ＜０．０１）；恢复期组略低于急性期组，但无统计学意义（Ｐ＞０．０５）。急性期血清ＩＬ－６含量与脑梗塞估测体积呈正相关关系（ｒ＝０．６４，Ｐ＜０．０５），而与脑梗塞发生部位无关。脑梗塞体积越大，血清ＩＬ－６值越大，提示血清ＩＬ－６含量的测定可能作为早期判断急性脑梗塞脑损害程度的指标。     

百日草几丁质酶基因片段克隆及其序列分析

[目的]克隆百日草几丁质酶的基因片段,并对其序列进行分析.[方法]以百日草“梦境”系列为材料,提取其叶片总RNA,并根据其他植物几丁质酶基因保守序列设计简并引物,通过RT-PCR克隆百日草几丁质酶基因片段（ZEchi）,并对该基因序列进行分析.[结果]克隆得到的片段长度为227 bp,共编码75个氨基酸残基;核苷酸同源性分析表明,ZEchi与已报道的其他植物几丁质酶基因同源性达70％以上,其中与葡萄的同源性最高,为74％;氨基酸同源性分析表明,该几丁质酶多肽属于18家族几丁质酶,且与已报道的其他植物几丁质酶氨基酸序列具有70％以上的相似性;氨基酸聚类分析表明,该几丁质酶多肽与白车轴草和蒺藜苜蓿的几丁质酶聚类;生物信息学分析表明,由该基因片段编码的多肽为非跨膜蛋白,主要含α螺旋和随机线圈螺旋等二级结构.[结论]该研究为进一步研究几丁质酶基因的功能奠定了基础.     

A 50,000-year record of climate oscillations from Florida and its temporal correlation with the heinrich events

Oscillations of Pinus (pine) pollen in a 50,000-year sequence from Lake Tulane, Florida, indicate that there were major vegetation shifts during the last glacial cycle. Episodes of abundant Pinus populations indicate a climate that was more wet than intervening phases dominated by Quercus (oak) and Ambrosia-type (ragweed and marsh-elder). The Pinus episodes seem to be temporally correlated with the North Atlantic Heinrich events, which were massive, periodic advances of ice streams from the eastern margin of the Laurentide Ice Sheet. Possible links between the Tulane Pinus and Heinrich events include hemispheric cooling, the influences of Mississippi meltwater on sea-surface temperatures in the Gulf of Mexico, and the effects of North Atlantic thermohaline circulation on currents in the Gulf.     

SNP标记位点与罗氏沼虾生长性状的相关分析

【目的】明确SNP标记位点与罗氏沼虾生长性状间的关联性,为罗氏沼虾生长性状候选基因的寻找、生长性状调控机理及后期分子标记辅助育种研究打下基础。【方法】采用直接测序技术对25个SNP标记位点在罗氏沼虾生长性状极端群体中进行多态性检测。采用卡方检验（χ2）筛选出2个极端（体长极大和极小）罗氏沼虾群体中与生长状况存在潜在相关性的SNP标记位点,进一步对罗氏沼虾浙江群体60个个体进行SNP基因型与生长性状（体长、头胸甲宽、第一腹节宽、第一腹节高和体重）的关联分析。运用一般线性模型对SNP标记位点与罗氏沼虾5个生长性状的关联性进行检测。【结果】卡方检验结果显示,SNP6、SNP7、SNP16、SNP20和SNP24等5个标记位点在罗氏沼虾极端群体中与生长性状存在潜在相关。5个潜在相关SNP标记位点与生长性状的相关性分析结果表明,SNP6、SNP7、SNP16和SNP24等4个位点与生长性状呈显著（P<0.05,下同）或极显著（P<0.01,下同）相关,其中位点SNP6与体长和体重关联极显著,与头胸甲宽关联显著;SNP7与体长、头胸甲宽、第一腹节宽和体重关联极显著,与第一腹节高关联显著;SNP16与头胸甲宽、第一腹节宽、第一腹节高和体重关联极显著,与体长关联显著;SNP24仅与第一腹节高关联显著。对浙江群体中60尾个体体长50%小个体和体长50%大个体2个群体中4个SNP位点的基因型频率进行统计,结果显示,SNP6和SNP24 2个标记与生长的关联性显著,SNP7和SNP16与生长的关联性极显著。【结论】HSP90和HGS基因可能是与罗氏沼虾生长相关的重要功能基因,研究结果为下一步基因定位及分子标记辅助育种提供了更多的标记基础。     

猪Ghrelin的基因克隆及其组织中mRNA分布的研究

从猪下丘脑、胃等组织中提取总RNA,根据已发表的猪Gkklin mRNA序列设计合成引物,通过反转录-聚合酶链式反应(RT-PCR)进行cDNA扩增,获得了282bp的片段,克隆于pMD-18T载体后进行序列分析,确认PCR产物为Ghrelin cDNA。检测结果表明：初生仔猪的下丘脑和90d生长猪下丘脑、胃底部、十二指肠、空肠、回肠、胰腺、肝脏、肾脏、心脏等部位组织中均有Ghrelin mRNA分布。