高效液相色谱法测定生物样品中儿茶酚胺及其代谢产物

目的 :建立一种测定生物中儿茶酚胺及其代谢产物的灵敏方法。方法 :样品经过磺基水杨酸去蛋白后直接进样 ,测定各种生物样品中的儿茶酚胺及其相关的代谢产物 ;流动相为 2 0mmol·L- 1 柠檬酸三钠 (pH4 .5 0 ) 甲醇(95∶5 ,V V) ,柱温 35℃ ,检测器电压为 0 75V。结果 :该方法能同时检测 7种化合物。最低检测限为 10～ 2 5pg·ml- 1 ,回收率均在 96 %以上 ,线性范围为 2 0pg·ml- 1 ～ 10 μg·ml- 1 。结论 :该方法灵敏可靠 ,能同时测定生物样品中的儿茶酚胺及其代谢产物     

大鼠脑内儿茶酚胺类递质及其代谢物的同时提取及反向高效液相测定法

目的建立一种操作简便、高效的测定脑组织中去甲肾上腺素(NA)、肾上腺素(AD)、多巴胺(DA)、3,4二羟基苯乙酸(DOPAC)及高香草酸(HVA)的方法,为有关药物作用机理的研究提供实验手段.方法以有机溶剂提取,高效液相色谱--电化学检测器(HPLC-EC)测定大鼠纹状体、皮质、下丘脑NA、AD、DA、DOPAC及HVA的含量.结果测得NA、AD、DA、DOPAC及HVA的绝对回收率依次分别为:80.3%±12.4%,86.5%±14.3%,90.3%±12.1%,89.5%±17.2%、87.6%±[13].2%.线性范围0.2～20ng,批内与批间变异系数分别小于8%及10%.结论该方法具有简便、迅速、回收率较高的特点,便于实验室应用.     

翼点入路对大脑中动脉主干分支及中央支的显微应用解剖

目的：探索经翼点入路对大脑中动脉及其分支的显微应用解剖及其临床应用。方法：对10具（20侧）红色乳胶颈内动脉和椎动脉灌注头颈部标本,于翼点入路下对大脑中动脉及其分支在手术显微镜下解剖观测。结果：大脑中动脉是颈内动脉的直接延续,其发出后先水平向外行为水平段M 1,然后分为M 2-M 5段。大脑中动脉的中央支动脉分为内侧群和外侧群;内侧群：在大脑中动脉起点1 cm内,约3-6支,多呈直角发出,较短而细;外侧群：从大脑中动脉起点1cm以外发出,约4-8支,多起源于大脑中动脉分叉处2mm范围内。结论：大脑中动脉主干为颈内动脉的延续,供血范围内易栓塞。其起始M 1、M 2段上壁、内侧壁发出的中央支多呈直角状,临床上易破裂出血。在M 1、M 2段下壁解剖可避免损伤其穿通支血管。     

儿茶酚胺的临床检测研究进展

儿茶酚胺与部分神经内分泌肿瘤有着密切关系。因此,儿茶酚胺的临床检测对上述疾病的早期预测及后期监测具有重要价值。现有多种检测儿茶酚胺的方法,但因生物样品中儿茶酚胺含量极微、易氧化且存在内源性干扰物,临床上尚缺乏标准化的检测方法。该文简要概述目前儿茶酚胺的检测方法及其优缺点,为儿茶酚胺的临床检测提供一定的参考价值。     

川芎哚在大鼠体内的代谢转化

目的 研究中药川芎中有效生物碱哚在大鼠体内的代谢转化。方法 给大鼠灌胃分别给予川芎哚和氘标记川芎哚后,收集尿样。将尿样本经酶水解,碱化,有机溶剂提取;有机相（碱性和中性部分）经浓缩并硅烷化,水相经酸化,吹干,提取（提取物为酸性水溶性部分）并硅烷化。采用气相层析－质谱联用仪测定提取的样品。结果 在碱性和中性提取物中,共检出原川芎哚及其一种代谢物,在酸性水溶性提取物中,共检出川芎哚的另外两种代谢物。结     

A sequence labeling approach to link medications and their attributes in clinical notes and clinical trial announcements for information extraction

Objective

The goal of this work was to evaluate machine learning methods, binary classification and sequence labeling, for medication–attribute linkage detection in two clinical corpora.

Data and methods

We double annotated 3000 clinical trial announcements (CTA) and 1655 clinical notes (CN) for medication named entities and their attributes. A binary support vector machine (SVM) classification method with parsimonious feature sets, and a conditional random fields (CRF)-based multi-layered sequence labeling (MLSL) model were proposed to identify the linkages between the entities and their corresponding attributes. We evaluated the system''s performance against the human-generated gold standard.

Results

The experiments showed that the two machine learning approaches performed statistically significantly better than the baseline rule-based approach. The binary SVM classification achieved 0.94 F-measure with individual tokens as features. The SVM model trained on a parsimonious feature set achieved 0.81 F-measure for CN and 0.87 for CTA. The CRF MLSL method achieved 0.80 F-measure on both corpora.

Discussion and conclusions

We compared the novel MLSL method with a binary classification and a rule-based method. The MLSL method performed statistically significantly better than the rule-based method. However, the SVM-based binary classification method was statistically significantly better than the MLSL method for both the CTA and CN corpora. Using parsimonious feature sets both the SVM-based binary classification and CRF-based MLSL methods achieved high performance in detecting medication name and attribute linkages in CTA and CN.     

Simple preparation of the major urinary metabolites of flunitrazepam and nitrazepam

An alarming increase in the misuse/abuse of nitrobenzodiazepine derivatives, especially flunitrazepam, prompted us to establish reliable analytical protocols for their routine detection. Whilst the parent drugs are readily available from a number of commercial sources, it was found difficult to obtain samples of the corresponding amino metabolites which were required as analytical standards. This lead us to develop the straightforward synthetic protocol described here, to convert the readily available parent drugs, namely flunitrazepam and nitrazepam, to their respective 7-amino derivatives. The method requires minimum laboratory facilities. It involves the reduction of the nitro functionality in the parent drug to an amino group using tin (II) chloride under mild conditions, using ultrasonication at room temperature. The method is simple and should give toxicology laboratories better access to these much needed compounds.     

窒息新生儿尿微量白蛋白和转铁蛋白测定的临床意义

目的 探讨窒息新生儿尿微量白蛋白(mAlb)和转铁蛋白(TRF)水平的变化及临床意义.方法 取61例窒息新生儿(轻度窒息32例,重度窒息29例)及35例无窒息及严重感染性疾病的同期住院新生儿生后24h尿液作mAlb和TRF检测;同时取血查肌酐(Cr)、尿素氮(BUN)进行对照.结果 窒息组尿mAlb、血Cr浓度及尿TRF异常率均较对照组明显升高,而重度窒息组尿mAlb、血Cr浓度及尿TRF异常率则较轻度组明显升高,均有极显著性差异(P＜0.01).但血BuN浓度在各组间比较差异均无统计学意义(P＞0.05).结论 尿mAlb、TRF升高与新生儿窒息程度及肾损害密切相关,是窒息新生儿早期肾功能监测灵敏、有效的指标.     

窒息新生儿尿微量白蛋白和转铁蛋白测定的临床意义

目的探讨窒息新生儿尿微量白蛋白（mAlb）和转铁蛋白（TRF）水平的变化及临床意义。方法取61例窒息新生儿（轻度窒息32例,重度窒息29例）及35例无窒息及严重感染性疾病的同期住院新生儿生后24h尿液作mAlb和TRF检测;同时取血查肌酐（Cr）、尿素氮（BUN）进行对照。结果窒息组尿mAlb、血Cr浓度及尿TRF异常率均较对照组明显升高,而重度窒息组尿mAlb、血Cr浓度及尿TRF异常率则较轻度组明显升高,均有极显著性差异（p〈0.01）。但血BUN浓度在各组间比较差异均无统计学意义（p〉0.05）。结论尿mAlb、TRF升高与新生儿窒息程度及肾损害密切相关,是窒息新生儿早期肾功能监测灵敏、有效的指标。     

Current issues in the design and interpretation of clinical trials

Though there have been considerable improvements in the use of statistical methods for clinical trials in recent years, there remain major practical difficulties in the design and interpretation of many trials. This paper concentrates on problems relating to randomisation, the overemphasis on significance testing, and the inadequate size of many trials. Each topic is illustrated by examples from recent trials.     

窒息新生儿血NGAL、CysC 和尿微量 蛋白的水平变化及临床意义

目的 探讨窒息新生儿尿α1 微球蛋白（α1-m）、β2 微球蛋白（β2-m）、白蛋白（Alb）、免 疫球蛋白G（IgG）、转铁蛋白（TRF）、血中性粒细胞明胶酶相关脂质运载蛋白（NGAL）及半胱氨酸蛋白酶 抑制剂（CysC）水平的变化及对新生儿早期肾损伤的诊断价值。方法 取187 例窒息新生儿（轻度窒息90 例, 重度窒息97 例）及95 例同期入院的健康新生儿出生后24 h 内取尿液作α1-m、β2-m、Alb、IgG 及TRF 检测;取12 h 内静脉血检测NGAL、CysC、BUN 及血肌酐（Scr）,并进行比较分析。结果 轻、重度窒息 组α1-m、β2-m、Alb、IgG、TRF、NGAL 及CysC 含量均较对照组升高（P <0.05）,重度窒息组α1-m、 β2-m、Alb、IgG、TRF、NGAL 及CysC 异常率高于轻度窒息组（P <0.05）。结论 α1-m、β2-m、Alb、 IgG、TRF、NGAL 及CysC 含量是窒息新生儿早期肾功能损伤监测的有效指标。而传统指标Scr 及BUN 在 窒息新生儿早期肾损伤的诊断中优越性不明显。     

2型糖尿病患者尿中血管内皮生长因子变化及其意义

目的了解2型糖尿病患者尿中血管内皮生长因子(VEGF)的改变,探讨检测VEGF在早期诊断糖尿病肾病和评价糖尿病肾病进展中的价值.方法根据24 h尿白蛋白排泄率(UAER)将68例2型糖尿病患者分为3组:正常蛋白尿组、微量蛋白尿组和临床蛋白尿组.采用ELISA等方法检测尿中VEGF、尿白蛋白(ALB)、尿视黄醇结合蛋白(RBP)等指标.结果与正常对照组比较,糖尿病各组尿VEGF水平明显增高(P值均<0.05).尿VEGF在微量蛋白尿组较正常蛋白尿组增高,临床蛋白尿组最高,糖尿病3组间尿VEGF比较差异有显著性(P值均<0.05).尿VEGF水平与尿白蛋白、尿视黄醇结合蛋白均呈显著正相关.结论糖尿病患者尿VEGF水平异常增高,检测尿VEGF的变化可能对监测肾病进展有重要意义.VEGF增高可能也反映糖尿病肾小管-间质病变.     

羊水儿茶酚胺水平的测定及临床意义探讨

作者采用高效液相色谱技术对羊水中儿茶酚胺（ＣＡ）水平进行了测定。结果表明：羊水中ＣＡ来自胎儿，并伴随妊娠的进展而逐渐增加，３６孕周以后迅速上升，与Ｌ／Ｓ比值呈正相关。