二阶导数分光光度法测定乳酸环丙沙星乳膏含量

目的建立乳酸环丙沙星含量测定的分析方法.方法采用二阶导数分光光度法,以282.5 nm为检测波长测定乳酸环丙沙星乳膏含量.结果在5～40 mg·L-1的范围内吸收度与浓度呈良好的线性关系(r=0.999 8),平均回收率为101.1%.结论用二阶导数分光光度法可排除基质干扰,准确测定乳酸环丙沙星乳膏的含量.     

EVALUATION OF MITOCHONDRIAL ENCEPHALOMYOPATHY WITH LACTIC ACIDOSIS AND STROKE-LIKE EPISODES WITH MAGNETIC RESONANCE IMAGING AND PROTON MAGNETIC RESONANCE SPECTROSCOPY

MITOCHONDRIAL encephalomyopathy (ME)is a mainly inherited, poly-symptomatic, andmulti-systemic group of metabolic disorderscaused by defects of mitochondrial structure and function·The clinical manifestations of ME are widely variable·Brain and muscle a…     

产时羊水粪染新生儿脐动脉乳酸水平的变化

目的 研究产时羊水粪染（meconium—staind amniotic fluid，MSAF）新生儿脐动脉血乳酸水平的变化及与血气分析新生儿结局的关系。方法 2005年2月至2006年3月245例足月妊娠、单胎、头位，无产科、内科合并症产妇，根据产时羊水有无MSAF分为两组，MSAF组（n=50），清亮组（n=195），检测脐动脉血乳酸、血气分析，以及新生儿行为神经测定（neonatal behavioral neudogioal assessment，NBNA）。结果 MSAF组与清亮组脐动脉血乳酸水平、pH值及碱剩余（BE）比较，差异无显著意义（P＞0．05）。脐血乳酸水平在MSAF程度之间，差异无显著意义（P＞0．05）。脐血乳酸与pH值、BE呈明显负相关关系（r=-0．64，r=-0．63，P＜0．01）。MSAF组合并产时异常胎心监护图形、酸中毒者，其脐动脉血乳酸水平明显升高，差异有显著意义（P＜0．05，P＜0．01）。新生儿NBNA评分，两组间相比差异无显著意义（P＞0．05）。结论 脐动脉血乳酸水平与pH值、BE有较好的相关性，产时单纯MSAF与提示急性窒息的指标乳酸无明显关系。     

噬菌体随机肽库筛选抗恶性疟原虫乳酸脱氢酶单抗2A5的识别表位

目的利用噬菌体随机肽库技术筛选恶性疟原虫乳酸脱氢酶(pfLOH)抗体2A5的识别表位。方法以抗pfLDH的单抗2A5筛选噬菌体随机12肽库,挑取阳性克隆测定DNA序列,推导其氨基酸序列并进行同源性分析。通过ELISA、竞争抑制试验鉴定获得的噬菌体短肽与单抗2A5之间的结合特性。结果从噬菌体随机12肽库中筛选出21株可与2A5单抗特异结合的噬菌体克隆,其中多数克隆呈现核心序列SQK(R)L,该序列与pfLDH的一级序列具有一定同源性。竞争抑制实验显示,带有核心序列的噬菌体克隆可与pfLDH竞争结合单抗2A5。结论 SQK(R)L是pfLDH单抗2A5特异识别的表位。     

不同厂家的银杏叶制剂对冷水负重游泳模型小鼠保护作用的比较研究

目的观察不同厂家银杏叶制剂(天保宁片和金纳多片)对冷水负重游泳模型小鼠的保护作用.方法小鼠8℃冷水负重游泳5min,测定模型小鼠的断头喘气持续时间,并采用分光光度法测定其脑组织生化代谢的改变.结果与空白对照组相比,模型小鼠脑组织乳酸(LA)含量明显增加,乳酸脱氢酶(LDH)、Na -K -ATP酶、Ca2 -Mg2 -ATP酶活力明显降低(P＜0.01);而2个EGB组均可以明显逆转模型小鼠上述生化指标的改变(P＜0.05,P＜0.01).结论不同厂家生产的EGB制剂均对冷水负重游泳模型动物具有保护作用,且在对模型小鼠脑组织生化代谢的影响上未显示出明显差异,故均可以作为耐缺氧研究的阳性药物.     

Lactate detection in inducible and orthotopic Her2/neu mammary gland tumours in mouse models

This study compared the steady state concentration of lactate in an inducible Her2/nue transgenic breast cancer mouse model and in tumours from the same Her2/neu model grown orthotopically. In vivo lactate was detected by MRS using the Hadamard encoded selective multiple quantum coherence pulse sequence (HadSelMQC) recently developed by our laboratory. A lower lactate signal was observed in the inducible tumours compared to orthotopic tumours in vivo, while ex vivo analysis of perchloric acid extracts revealed similar amounts of this metabolite in both models. Histological staining of mammary tumour specimens showed a much higher level of fat tissue in inducible tumours compared to the orthotopic model. Phantom studies with [3‐¹³C] lactate indicated that a lipid environment could significantly reduce the T2 of lactate and impede its detection. The transgenic inducible model for breast cancer not only better recapitulated the biological aspects of the human disease but also provided additional characteristics related to in vivo detection of lactate that are not available in orthotopic or xenograft models. This study suggests that the level of lactate measured by the HadSelMQC pulse sequence may be underestimated in human patients in the presence of high lipid levels that are typically encountered in the breast. Copyright © 2012 John Wiley & Sons, Ltd.