Sensitivity and Specificity of Cardiac Tissue Discrimination Using Fiber-Optics Confocal Microscopy

Disturbances of the cardiac conduction system constitute a major risk after surgical repair of complex cases of congenital heart disease. Intraoperative identification of the conduction system may reduce the incidence of these disturbances. We previously developed an approach to identify cardiac tissue types using fiber-optics confocal microscopy and extracellular fluorophores. Here, we applied this approach to investigate sensitivity and specificity of human and automated classification in discriminating images of atrial working myocardium and specialized tissue of the conduction system. Two-dimensional image sequences from atrial working myocardium and nodal tissue of isolated perfused rodent hearts were acquired using a fiber-optics confocal microscope (Leica FCM1000). We compared two methods for local application of extracellular fluorophores: topical via pipette and with a dye carrier. Eight blinded examiners evaluated 162 randomly selected images of atrial working myocardium (n = 81) and nodal tissue (n = 81). In addition, we evaluated the images using automated classification. Blinded examiners achieved a sensitivity and specificity of 99.2±0.3% and 98.0±0.7%, respectively, with the dye carrier method of dye application. Sensitivity and specificity was similar for dye application via a pipette (99.2±0.3% and 94.0±2.4%, respectively). Sensitivity and specificity for automated methods of tissue discrimination were similarly high. Human and automated classification achieved high sensitivity and specificity in discriminating atrial working myocardium and nodal tissue. We suggest that our findings facilitate clinical translation of fiber-optics confocal microscopy as an intraoperative imaging modality to reduce the incidence of conduction disturbances during surgical correction of congenital heart disease.     

水稻白叶枯病菌GX1329基因组文库的构建及含编码TAL效应物基因的克隆的分离

由革兰氏阴性细菌水稻白叶枯病菌引起的水稻白叶枯病是亚洲、北美以及非洲部分地区最严重的水稻病害之一,水稻白叶枯病可使水稻减产高达50%以上.研究表明水稻白叶枯病菌的毒力主要依靠三型分泌系统所分泌的效应物.为了解水稻白叶枯病菌广西菌株GX1329中含有avrBs3/pthA家族基因的情况,本研究应用AluⅠ部分酶切其基因组DNA,构建了含有736个克隆的菌株GX1329的基因组文库.BamHⅠ酶切分析随机挑取的15个文库克隆表明,克隆的外源DNA随机性良好,克隆的最小片段为27.7 kb,最大为58.5 kb,平均大小为39.9 kb,文库克隆容量约为2.8×103 Mb,该文库中包含基因组中任一个基因的概率为99.4%.利用来自水稻白叶枯病菌菲律宾菌株PXO86的无毒基因avrXa10的第252位~第486位核苷酸序列作为探针,通过菌落原位杂交从GX1329基因组文库中筛选到37个含avrBs3/pthA家族基因的克隆.再通过Southern杂交分析,得到了17个独立克隆.这17个克隆中至少含有13个不同的avrBs3/pthA家族基因.这些基因在GX1329基因组中有的单独存在,有的两个或两个以上串联存在.本工作基本上明确了菌株GX1329基因组中avrBs3/pthA家族基因的数量,为进一步研究菌株GX1329中avrBs3/pthA家族基因的功能奠定了基础.     

P110 and P140 Cytadherence-Related Proteins Are Negative Effectors of Terminal Organelle Duplication in Mycoplasma genitalium

Background

The terminal organelle is a complex structure involved in many aspects of the biology of mycoplasmas such as cell adherence, motility or cell division. Mycoplasma genitalium cells display a single terminal organelle and duplicate this structure prior to cytokinesis in a coordinated manner with the cell division process. Despite the significance of the terminal organelle in mycoplasma virulence, little is known about the mechanisms governing its duplication.

Methodology/Principal Findings

In this study we describe the isolation of a mutant, named T192, with a transposon insertion close to the 3′ end of the mg192 gene encoding for P110 adhesin. This mutant shows a truncated P110, low levels of P140 and P110 adhesins, a large number of non-motile cells and a high frequency of new terminal organelle formation. Further analyses revealed that the high rates of new terminal organelle formation in T192 cells are a direct consequence of the reduced levels of P110 and P140 rather than to the expression of a truncated P110. Consistently, the phenotype of the T192 mutant was successfully complemented by the reintroduction of the mg192 WT allele which restored the levels of P110 and P140 to those of the WT strain. Quantification of DAPI-stained DNA also showed that the increase in the number of terminal organelles in T192 cells is not accompanied by a higher DNA content, indicating that terminal organelle duplication does not trigger DNA replication in mycoplasmas.

Conclusions/Significance

Our results demonstrate the existence of a mechanism regulating terminal organelle duplication in M. genitalium and strongly suggest the implication of P110 and P140 adhesins in this mechanism.     

Effectors ofd-[3H]aspartate release from rat cerebellum

The effect of aminooxyacetic acid (AOAA), NH₄ ⁺, phenylsuccinate (Phs), ketone bodies (KB) and glutamine (Gln), that might interfere with the biosynthesis of neurotransmitter glutamate on the K⁺-evoked Ca²⁺-dependent release ofd-[³H]aspartate from rat cerebellar slices was studied. Therefore slices were preincubated in a Krebs-Ringer-bicarbonate-glucose (KR) buffer, loaded withd-[³H]aspartate and superfused in the presence of Ca²⁺ or when Ca²⁺ was replaced by Mg²⁺ or in some cases by EGTA. AOAA, NH ₄ ⁺ and Phs increase the K⁺-evoked Ca²⁺-dependent release of radioactivity by 30%, 68% and 188% compared to the control respectively indicating that these agents are inhibitors of the K⁺-evoked Ca²⁺-dependent release of glutamate. KB and Gln had no effect on the Ca²⁺-dependent release of radioactivity. AOAA., NH ₄ ⁺ , Phs and KB but not Gln increase the total release of radioactivity by 43%, 69%, 139%, and 37% respectively. AOAA, NH ₄ ⁺ and KB but not Phs or Gln increase the Ca²⁺-independent release (Mg²⁺ replacing Ca²⁺) of radioactivity by 71%, 71% and 108% respectively. The present results indicate that in the cerebellum: 1) Neurotransmitter glutamate is mostly synthesized through the phosphate activated glutaminase (PAG) reaction 2) It is further supported that glutamate released in a Ca²⁺-dependent manner before entering its pool in the cytosol has to move into the mitochondrial matrix.     

中国红豆杉枝叶中的紫杉烷二萜

从中国红豆杉(Taxus chinensis)枝叶的乙醇提取物中分离得到8个紫杉烷二萜,通过波谱分析分别确定为：14p羟基巴卡亭Ⅵ(1),巴卡亭Ⅵ(2),巴卡亭Ⅳ(3),1β-去羟基巴卡亭Ⅳ(4),云南红豆杉酯甲(5),2α-去乙酰-2α-苯甲酰基-13α-乙酰基云南紫杉亭(6),5α-羟基-2α,7βp,9α,10β,13α-五乙酰氧基紫杉-4(20),11-二烯(7)和Taxaein(8)。其中化合物1为新化合物,并报道八个化合物在丙酮中测得的核磁共振信号,化合物8的数据属首次报道。     

马缨杜鹃茎的化学成分研究

利用各种色谱技术从马缨杜鹃(Rhododendron delavayi Franch.)茎中分离得到10个化合物。通过波谱学方法鉴定为异鼠李素(1),nectandrin B(2),resveratrol-3-O-β-D-glucoside(3),lysidiside N(4),19α-hydroxyasiatic acid(5),白桦脂酸(6),3β-hydroxylup-12-en-28-oic-acid(7),obtusalin(8),methyl 2,4-dihydroxy-6-methylbenzoate(9),2,5-dihydroxy-3-methoxytoluene(10)。化合物2～9为首次从该种植物中分离得到。     

大果榕茎的化学成分(英文)

运用硅胶柱色谱和Sephadex LH-20柱色谱,以及制备薄层色谱等方法从大果榕茎的95%乙醇提取物中分离得到11个化合物,通过理化性质和波谱数据鉴定为:染料木黄酮(1),wighteone(2),5,7,4’,trihydroxy-6-(2-hydroxy-3-methyl-3-butenyl)isoflavone(3),5,7,4’-trihydroxy-3’-(2-hydroxy-3-methyl-3-butenyl)isoflavone(4),alpin-umisoflavone(5),derrone(6),(3R)-5-formylmellein(7),3β-(1-Hydroxyethyl)-7-hydroxy-1-isobenzofuranone(8),反式对羟基肉桂酸乙酯(9),β-谷甾醇(10),β-胡萝卜苷(11)。化合物4,7,8,9为首次从该属植物中分离得到,化合物1-10为首次从该植物中分离得到。     

云南金钱槭茎化学成分

对云南金钱槭枝条部分的化学成分进行了研究,从其乙醇提取物中共分离鉴定了16个化合物,通过波谱学方法鉴定为:erythro-4,7,9-三羟基-3,3'-二甲氧基-8-O-4'-新木脂素-9'-O-β-D-吡喃葡萄糖苷(1),Hyugano-side IIIa(2),Hyuganoside IIIb(3),erythro-Buddlenol B(4),erythro-7',8'-Didehydrobuddlenol B(5),(±)-丁香脂素(6),臭矢菜素A(7),柑橘苷A(8),(4R)-p-薄荷-1-烯-7,8-二醇7-O-β-D-吡喃葡萄糖苷(9),2-甲氧基-3-(3-吲哚基)丙酸(10),肌苷(11),Tachioside(12),Isotachioside(13),3-O-(β-D-吡喃葡萄糖基)-1-(3,5-二甲氧基-4-羟基苯基)-1-丙酮(14),反式异松柏苷(15),4-[(E)-3-乙氧基-1-丙烯基]-2-甲氧基苯酚(16)。其中化合物5为新的倍半木脂素,其余化合物均首次从该属植物中分离得到。     

蝉翼藤茎中的两个新(口山)酮成分

首次从蝉翼藤(Securidaca inappendiculata Hassk)茎乙醇提取物的乙酸乙酯部分分离到两个新的具有抗氧化作用的(口山)酮类化合物securixanthone C (1) 和 securixanthone D (2).这两个新化合物的结构是通过波谱方法(1D-NMR和2D-NMR、 EI-MS、 UV 和IR)鉴定的.     

蝉翼藤茎中的两个新酮成分(英文)

首次从蝉翼藤 (SecuridacainappendiculataHassk)茎乙醇提取物的乙酸乙酯部分分离到两个新的具有抗氧化作用的口山酮类化合物securixanthoneC (1)和securixanthoneD (2 )。这两个新化合物的结构是通过波谱方法 (1D_NMR和 2D_NMR、EI_MS、UV和IR)鉴定的。     

The Measurement and Interpretation of Ultrasound from Woody Stems

A system for detecting and counting ultrasonic acoustic emissions(AEs) from woody stems in the waveband of 0.1–1.0 MHzis described. AEs from small pieces of stems of Mains sylvestrisand Chamaecyparis lawsoniana occurred up to a rate of 6000 min^–1,and could be related to the water loss as the stems dried. AEsdid not occur randomly, but were aggregated. Each event is interpretedas a single cavitation occurring in the water within a tracheidor fibre. AEs could be temporarily stopped by rewetting thetissue or cutting it to release tension. From knowledge of thenumber of cells in the stems, the fraction of total counts pernumber of tracheids or fibres present in the stem was calculated.This was found to be less than 0.16. One reason why this fractionis so low is that AEs may occur simultaneously; it is also probablethat some AEs emit energy outside the waveband studied. Eventhough the fraction of AEs recorded is low, this instrumentcould prove to be a very powerful tool for investigating theoccurrence of cavitation in woody stems. Key words: Ultrasound, Cavitation, Wood     

黄瓜藤的化学成分研究

从丽江产黄瓜藤甲醇提取物的氯仿部位分离得到9个化合物,经理化和波谱分析鉴定为α-菠甾醇(1)、α-菠甾醇-3-O-β-D-葡萄糖苷(2)、β-谷甾醇(β-sitosterol,3)、豆甾-7-烯-3-O-β-D-葡萄糖苷(4)、22-亚甲基-9,19-环羊毛甾烷-3β-醇(5)、(2S,3S,4R,10E)-2-(2′,3′-二羟基二十四烷酰氨基)-10-十八烯-1,3,4-三醇(6)、(2S,3S,4R,10E)-2-[(2′R)-2-羟基二十四烷酰氨基]-10-十八烯-1,3,4-三醇(7)、(2S,3S,4R,10E)-1-(β-D-葡萄糖苷)-2-[(2′R)-2-羟基二十四烷酰氨基]-10-十八烯-1,3,4-三醇(8)、大豆脑苷(9),除化合物3外,其它化合物均为首次从该植物中分离得到.