中国石松目植物的修订

本文作者通过长期的野外观察,鉴定和整理全国各主要植物标本室的石松目植物标本,结合查阅有关文献资料,采用植物的形态演化规律研究了本目植物的分类,阐明了中国石松目植物各科属间的进化关系.报道了1个新种,1个新记录种,并对3种植物名称进行了修订.     

华南马尾杉生物碱成分的研究

目的：研究石杉科华南马尾杉[Phlegmariurus fordii(Baker)Ching]中的生物碱成分。方法：应用多种色谱技术对华南马尾杉总碱部分进行分离纯化，依据四大光谱数据解析鉴定化合物结构。结果：从华南马尾杉中分得1个单体生物碱。结论：该化合物为一个新结构生物碱，命名为异福定碱（isofordine）。     

福定碱(fordine)的结构测定

华南马尾杉[Phlegmariurus fordii(Baker)Ching]为石杉科(Huperziaceae)新品种植物。我们于1970年在对三千多种中草药普筛中发现,华南马尾杉水煎剂对胆碱酯酶具有保护作用。为此,对其生物碱成分进行了系统分离鉴定。从中分得几个生物碱成分,其中一个生物碱经光谱分析及X射线单晶衍射证明为新成分,我们将其命名为福定碱(fordine)。进一步药理实验证明,它是一种新结构类型的胆碱酯酶保护剂,对真性胆碱酯酶具有选择性抑制作用。本文对福定碱的结构测定作一概述。     

石松目植物主要元素含量变化与分类群关系的研究

作者采用 Carlo Erba 1106或1500型自动元素分析仪测定了石松科与石杉科5属26种(21种5变种或变型)植物全草样品中 C,H,N 和 O 的含量。分析了不同季节、不同地区和不同植株等因素对植物元素含量变化的影响和元素含量的变化与植物分类群(种或种下分类群)之间的关系。结果表明,采集样品的季节对植物元素含量有一定的影响,尤其是生长期长的营养器官(枝叶、茎或草本植物的全草);而植物的产地、植株等因素几无影响;不同植物分类群的元素含量的变化与形态学之间有一定的关系,即形态上易区分的分类群,元素含量的变化较大,反之亦然。值得进一步深入系统地研究两者之间的关系,这将为植物分类学增添新的科学佐证。     

福定碱(FORDINE)的结构测定

从华南马尾杉中分离得到一个新的石松生物碱,通过光谱测定(~1H-NMR。~(13)C-NMR和X-射线衍射分析等),阐明了化学结构并将其命名为福定碱(Fordine)。经过系统药理学研究表明,该生物碱具有良好抗胆碱酯酶效应,从而可认为该生物碱系一种新结构类型的可逆性胆碱酯酶抑制剂。     

蛇足石杉生物碱成分的研究（Ⅴ）

目的：研究石杉科蛇足石杉Huperzia serrata(THunb.)Trev。中的生物碱成分。方法：用各种色谱技术进行分离纯化,根据光谱分析鉴定其结构。结果：从蛇足石杉中分离得一个生物碱成分（碱A）。结论碱A为新化合物,命名为蛇足石杉碱乙（huperzinineB)。     

HPLC法测定石杉科植物中石杉碱甲的含量

目的：建立用高效液相色谱法（ＨＰＬＣ）测定石杉科植物中石杉碱甲（ｈｕｐｅｒｚｉｎｅ Ａ）含量的方法。方法与结果：按照常规的方法提取出石杉总生物碱,用ＨＰＬＣ对总碱直接进行分析。色谱条件下如：Ｓｐｈｅｒｉｓｏｒｂ Ｃ１８分析柱,检测波长２３１．３ｎｍ,甲醇：水（８５：１５,体积分数）作为流动相,流速１ｍｌ／ｍｉｎ。外标法测定。该方法的一范围是０．４１～６．１５ｍｇ／Ｌ,平均加祥回收率为９９．７２％～     

石杉碱甲与银杏内酯B联合用药跨细胞转运研究

目的利用Caco-2和MDCK细胞单层模型探讨石杉碱甲与银杏内酯B的跨细胞转运过程及其机制。方法建立Caco-2和MDCK细胞单层模型,将Caco-2和MDCK细胞分别按密度1×105、5×104个细胞/cm2接种到transwell culture plate inserts上培养,待细胞单层达到一定密度程度后进行转运实验。用高效液相色谱法测定石杉碱甲和银杏内酯B在不同侧面、不同浓度条件的跨单层细胞转运的情况,同时计算累计的透过量。结果在两种不同单层细胞模型上,石杉碱甲与银杏内酯B都有不同程度的吸收和分泌。结论石杉碱甲和银杏内酯B跨细胞转运同时存在吸收和分泌的动力学过程。     

褪黑素在γ射线诱导的小鼠放射性肠损伤中对肠道菌群的影响

目的探讨褪黑素在γ射线诱导的小鼠放射性肠损伤中对肠道菌群的影响。方法采用简单随机分组法将C57BL/6J雄性小鼠分为3组, 即对照组(不给予任何处理)、照射组(以13 Gy剂量对小鼠进行腹部照射)和褪黑素+照射组(对小鼠实施褪黑素给药, 连续5 d, 然后以13 Gy剂量进行腹部照射), 每组5只, 共15只。照射后3 d收集小鼠粪便, 进行16S rDNA扩增子测序, 分析小鼠肠道菌群的变化, 应用Uparse软件进行操作分类单元聚类和物种注释, 应用Qiime微生物组分析平台进行样品复杂度分析和多样品比较分析。结果巴斯德菌属、分节丝状菌属和拟杆菌属是褪黑素+照射组小鼠肠道中丰度最大的菌群。与对照组相比, 褪黑素+照射组小鼠肠道菌群的丰度和多样性均下降(均P<0.01), 群落结构增加(P<0.001)。由门至种的不同分类级别的变形菌门/纲、肠杆菌目/科、巴斯德菌目/科/属/种和梭状芽孢杆菌纲/目是褪黑素+照射组小鼠肠道菌群组间丰度最大的菌群。在构建小鼠肠道菌群优势菌属共发生网络中, 确定了变形菌门、放线菌门、拟杆菌门和厚壁菌门这四大门类下占互作主导地位的菌属以及它们之间...     

综述·讲座不同蜂种蜂蛰伤致病及蜂毒毒理特点的研究进展

蜂类是膜翅目中除外蚁科的昆虫总称,膜翅目又分为细腰目和广腰目。蜜蜂和胡蜂均属于同一门、同一纲的膜翅目,但分属蜜蜂科和胡蜂科。胡蜂与黄蜂均属于胡蜂科,但胡蜂属广腰亚目,黄蜂属细腰亚目,是同一纲、目、科,不同亚目的蜂类。蜂毒是一种透明毒液,贮存毒囊中,由蛰针排出。其化学成分包括多肽类、酶类和非肽类物质。蜂毒对     

Subsegmental pulmonary emboli: improved detection with thin-collimation multi-detector row spiral CT

PURPOSE: To compare different reconstruction thicknesses of thin-collimation multi-detector row spiral computed tomographic (CT) data sets of the chest for the detection of subsegmental pulmonary emboli. MATERIALS AND METHODS: A multi-detector row spiral CT protocol for the diagnosis of pulmonary embolism was used that consisted of scanning the entire chest with 1-mm collimation within one breath hold. In 17 patients with central pulmonary embolism, the raw data were used to perform reconstructions with 1-mm, 2-mm, and 3-mm section thicknesses. For each set of images, each subsegmental artery was independently graded by three radiologists as open, containing emboli, or indeterminate. RESULTS: For the rate of detection of emboli in subsegmental pulmonary arteries, use of the 1-mm section width yielded an average increase of 40% when compared with the use of 3-mm-thick sections (P <.001) and of 14% when compared with the use of 2-mm-thick sections (P =.001). With the use of 1-mm sections versus 3-mm sections, the number of indeterminate cases decreased by 70% (P =.001). Interrater agreement was substantially better with the use of 1-mm and 2-mm sections than with the use of 3-mm sections. CONCLUSION: For the diagnosis of subsegmental pulmonary emboli at multi-detector row CT, the use of 1-mm section widths results in substantially higher detection rates and greater agreement between different readers than the use of thicker sections.     

自动化容积成像自动获取中孕期正常胎儿心脏标准切面的评估

目的:探讨利用自动化容积成像(volume computer aided diagnosis,VCAD)自动获取胎儿心脏筛查切面,并与二维超声(2D)比较,进一步提高中孕期胎儿心脏的筛查效率。方法:以100例中晚孕期经常规超声筛查,心脏未见异常的正常胎儿为研究对象。在2D模式下采集胎儿心脏筛查所需要的标准切面,包括四腔心(four-chamber view,4CV),五腔心(five-chamber view,5CV)、左右室流出道(left ventricular outflow track LVOT、right ventricular outflow track RV-OT),大动脉短轴(Artery short-axis SAV),主动脉弓(aortic arch LAV-AoA),动脉导管弓(ductal arch LAV-DA)、上下腔静脉长轴(superior-inferior vena cava,SVC-IVC)切面,记录采集时间。采用(Spatio-Temporal Image Correlation)STIC技术扫描获得胎儿心脏整体容积数据,存盘后进行脱机分析。利用4DVIEW 7.0软件VCAD技术,通过模式自带的SetStarting Plane的Start Plane、cardiac 1、cardiac 2、cardiac 3、cardiac 4、cardiac 5,分别自动获取上述各切面图像,并记录采集时间。比较VCAD技术自动获取的图像和2D图像吻合率及图像质量。采用超声断层显像(Tomographic UltrasoundImaging TUI)模式,通过调节层距和中心层位置,分别显示上述各切面,并记录采集时间。比较STIC-TUI检查时间和VCAD检查时间。结果:①VCAD检查时间:(138±10)s至(198±12)s明显小于2D检查时间(288±13)s和STIC-TUI检查时间(408±18)s,差异均有统计学意义;②VCAD自动获取切面和2D切面图像合格率的比较:扫描起始切面为心轴位于右上象限的心尖四腔心切面的容积数据样本,二维超声显示的筛查切面与VCAD重现的上述各切面合格率差异均无显著性(P>0.05)。扫描起始切面为心轴不位于右上象限的心尖四腔心切面的样本,容积数据利用VCAD自动获得的图像,配对卡方检验显示,LAV-AoA、LAV-DA、SAV切面,VCAD重建切面合格率低于2D,两者相比差异有统计学意义(P=0.045,P=0.045,P=0.001,<0.05);③VCAD和2D获取各个切面图像质量的比较:扫描起始切面为为心轴位于右上象限的心尖四腔心切面的样本,VCAD自动获取各切面图像质量和2D达到了极好的一致性或好的一致性。扫描起始切面为心轴不位于右上象限的心尖四腔心切面的样本,VCAD自动获取切面在4CV、5CV切面图像质量和2D达到了极好的一致性,在LVOT、RVOT和SVC+IVC切面图像质量和2D一致性好,在LAV-AoA、LAV-DA和SAV切面图像质量和2D的一致性差。结论:VCAD快速自动且较全面的获得胎儿心脏筛查各标准化切面高品质的图像信息,简化了三维容积数据的后处理方法,提高了超声诊断的准确性。     

A more efficient magnetic resonance imaging-based strategy for measuring quadriceps muscle volume

PURPOSE: To determine the accuracy of several magnetic resonance imaging (MRI)-based strategies for assessment of quadriceps muscle volume (MV) and changes in MV with training. METHODS: Images were acquired along the length of both thighs from young (26 +/- 3 yr, N= 23) and older (69 +/- 3 yr, N= 24) men and women before and after strength training. The quadriceps cross-sectional area (QCSA) of each section was measured before and after training. MV was directly assessed using all of the sections (each 9-mm thick with a 1-mm gap). Alternative estimates of MV were calculated using increasingly greater intervals between sections: every 1.1 cm (MV2), 3.1 cm (MV4), 5.1 cm (MV6), 7.1 cm (MV8), 9.1 cm (MV10), and a single QCSA (L1). The 95% limits of agreement (LOA, +/- 2 SD) between each alternative measure and the criterion measure MV were determined with Bland and Altman plots. Regression was used to predict MV from L1 and to obtain the standard error of the estimate (SEE). RESULTS: Before training, the 95% LOA with MV for the alternative measures ranged from 0.7% to 6.36% of MV, and the prediction of MV from L1 yielded a SEE x 2 of 14.1% of MV. For change in the alternative measures, the 95% LOA ranged from 10.3% to 26.3% of the total change in MV, and the prediction of deltaMV from deltaL1 yielded a SEE x 2 of 60% of the change in MV. CONCLUSION: Increasingly greater intervals between axial MRI sections result in substantially reduced agreement with a criterion measure of MV. The use of one axial section results in relatively higher error and thus should be used only when large effect sizes are expected.     

Influence of partial volume on venous output and arterial input function

BACKGROUND: CT perfusion (CTP) is an important diagnostic tool for the imaging of cerebral hemodynamics. To obtain quantitative values of cerebral blood volume (CBV), blood flow (CBF), and mean transit time (MTT), measurement of the arterial input function (AIF) is required. To correct for partial volume effects (PVEs), it is common to normalize the AIF with respect to the venous output function (VOF). This correction assumes that measurement of the VOF is unhampered by PVEs. The purpose of this study was to evaluate the effect of PVE on the measurement of the AIF and VOF and, consequently, on the absolute perfusion parameters. METHODS: In 10 patients the mean area under the curve (AUC) of the AIF and VOF were quantified for 3-, 6-, and 12-mm-thick sections. Differences in the mean (1) AUC of the VOF, (2) AUC of the AIF, and (3) width of the AIF were compared for the 3 section thicknesses, and the influence on the absolute values of CBV, CBF, and MTT were studied. RESULTS: With thinner sections, the AUC of the VOF and the AIF increased significantly and the width of the AIF decreased slightly. Differences in AUC between the 3 section thicknesses were larger for the AIF than for the VOF. CONCLUSION: PVEs affect not only the AIF, but also the VOF. This results in an overestimation of CBV and CBF when a thicker section is used. To avoid PVE, VOF measurements should be performed at lower section thicknesses.     

MR imaging of the temporomandibular joint: a validation experiment in vitro

RATIONALE AND OBJECTIVES: The authors compared magnetic resonance (MR) image quality obtained from 3- and 1-mm-thick sections in the depiction of the temporomandibular joint (TMJ) and its adjacent structures. MATERIALS AND METHODS: Eight TMJ specimens from four adult cadaver heads were depicted with MR imaging. Both 3- and 1-mm-thick sections were generated. One oral and maxillofacial radiologist, who was blinded to section thickness, evaluated the anatomic details of the images. Subsequently, the joints were surgically explored by two oral and maxillofacial surgeons, and the physical findings were recorded. RESULTS: Some statistically significant differences were found between the physical findings and the 3-mm-thick section images, while no significant differences were found with the 1-mm-thick sections. CONCLUSION: The TMJ and its adjacent structures were better depicted by thinner MR images.     

Quantitation of T2 lesion load in patients with multiple sclerosis: a novel semiautomated segmentation technique

RATIONALE AND OBJECTIVES: The authors designed a segmentation technique that requires only minimal operator input at the initial and final supervision stages of segmentation and has computer-driven segmentation as the primary determinant of lesion boundaries. The technique was applied to compute total T2-hyperintense lesion volumes in patients with multiple sclerosis (MS). A semi-automated segmentation technique is presented and shown to have a test-retest reliability of <5%. MATERIALS AND METHODS: The method used a single segmented section with MS lesions. A probabilistic neural net performed segmentation into four tissue classes after supervised training. This reference section was deconstructed into the entire set of possible 4 x 4-pixel subregions, which was used to segment all-brain sections in steps of 4 x 4-pixel, adjacent image blocks. Intra- and interimage variabilities were tested by using 3-mm-thick, T2-weighted, dual-echo, spin-echo MR images from five patients, each of whom was imaged twice on the same day. Five different reference sections and three temporally separated. training sessions involving the same reference section were used to test the segmentation technique. RESULTS: The coefficient of variation ranged from 0.013 to 0.068 (mean +/- standard deviation, 0.037 +/- 0.039) for results from five different reference sections for each brain and from 0.007 to 0.037 (mean, 0.027 +/- 0.021) for brains segmented with the same reference section on three temporally separated occasions. Test-retest (intra-imaging) reliability did not exceed 5% (except for a small lesion load of 1 cm3 in one patient). Interimaging differences were approximately 10%. CONCLUSION: The segmentation technique yielded intra-imaging variabilities (2%-3%, except for very small MS lesion loads) that compare favorably with previously published results. New repositioning techniques that minimize imaging-repeat imaging variability could make this approach attractive for resolving MS lesion detection problems.     

兔膝关节半月板滑膜被覆的实验性研究——光镜观察部分

本文应用实验形态学研究方法,对兔半月板的组织学切片作一般染色和特殊染色,在不同切面上均观察到半月板表面有一层明显的滑膜被覆,特殊染色法证实为与胶原纤维同一染色特性的滑膜组织,而且这层滑膜是关节囊滑膜的延续。     

Coronary artery calcium: absolute quantification in nonenhanced and contrast-enhanced multi-detector row CT studies

PURPOSE: (a) To determine the accuracy of multi-detector row computed tomography (CT) in the measurement of the calcium concentration in a cardiac CT calibration phantom and (b) to assess the correlation of a traditional 3-mm section width CT coronary screening protocol and a 1.25-mm section width CT angiography imaging protocol in the quantification of the absolute mass of coronary calcium in patients who underwent both coronary screening and CT angiography with a multi-detector row CT scanner. MATERIALS AND METHODS: A heart phantom containing calcified cylinders was scanned to determine calibration factors and absolute calcium mass. In 50 patients, the variability (value 1 - value 2/mean value 1 - value 2), limit of agreement (+/-2SD value 1 - value 2), and systematic error (mean value 1 - value 2) of the total amount of coronary calcium calculated at traditional 3-mm section width CT and at 1.25-mm section width CT angiography were determined. RESULTS: The correlation coefficient between the 3-mm section width, nonenhanced protocol and the 1.25-mm section width CT angiography protocol was very high (r = 0.977) and the mean variability was low (19.7%) for the absolute mass. There was a systematic error of -6.7 mg and a limit of agreement between 45.0 mg and -58.5 mg. CONCLUSION: Use of the mass quantification algorithm in combination with a calibration phantom allows accurate quantification of coronary calcium. Measurements of calcium mass obtained at 1.25-mm section width CT angiography have the best agreement with those obtained at the traditional 3-mm section width imaging protocol.