血管内皮细胞生长因子受体KDR基因靶向RNA干扰质粒的构建

目的:应用RNA干扰技术设计构建针对血管内皮细胞生长因子受体KDR的小干扰RNA,并观察脂质体转染肺癌细胞A549后的干扰效果。方法:实验于2005-03/2006-01在沈阳医学院生物化学及分子生物学教研室完成。①设计针对KDR编码区有短发夹结构的3条mRNA序列,经退火成互补双链,克隆到pGCsi.H1/neo/GFP载体中构建3个重组质粒,分别命名为KDR-siRNA1、KDR-siRNA2和KDR-siRNA3。②设立5组:小干扰RNA组,分别转染KDR-siRNA1、KDR-siRNA2和KDR-siRNA3;阳性对照组,转染pGCsi.H1/neo/siGFP,该质粒载体中的插入序列为针对绿色荧光蛋白的小干扰RNA,不干扰待研究的内源性基因;阴性对照组,转染pGCsi.H1/neo/GFP/NON,该载体为不干扰任何内源性基因的小干扰RNA;空白对照组,转染pGCsi.H1/neo/GFP空载体;正常对照组,不进行任何转染。③对重组质粒进行酶切鉴定、DNA测序分析;脂质体法转染质粒至肺癌A549细胞株后,实时定量PCR检测KDRmRNA的水平变化;细胞计数法绘制细胞生长曲线。结果:①小干扰RNA表达载体的鉴定:KDR-siRNA1、KDR-siRNA2和KDR-siRNA3表达载体用限制性内切酶NdeⅠ和SmaⅠ进行单酶切后,均产生约713bp、5480bp和2403bp、3790bp两个片段,与预期结果相同。测序结果与设计的编码相应短发夹状KDR-小干扰RNA的寡核苷酸序列一致,证明KDR-小干扰RNA真核表达载体构建成功。②KDR-小干扰RNA对A549细胞中KDRmRNA水平的影响:与阳性对照组、阴性对照组、空白对照组和正常对照组的A549细胞相比,KDR-siRNA1,2,3表达载体转染后的A549细胞KDR基因表达水平均明显受到抑制,抑制率分别为64%、81%和72%,其中以KDR-siRNA2抑制作用最为明显。③KDR-小干扰RNA对A549细胞生长的影响:阳性对照组、阴性对照组、空白对照组、正常对照组的A549细胞生长趋势较为一致,且生长速度均明显高于转染3种KDR-小干扰RNA表达载体的A549细胞,从接种第2天开始差异有显著性意义(t=15.29～17.65,P均<0.01)。结论:血管内皮细胞生长因子受体KDR靶向RNA干扰重组质粒构建成功,该载体能有效抑制肺癌A549细胞KDR基因表达与细胞增殖。     

Distal humerus lateral condyle fracture and Monteggia lesion in a 3-year old child: a case report

We describe a case of a Monteggia fracture dislocation and an ipsilateral lateral humeral condyle fracture in a 3-year-old child. This is a rare combination of injuries with no previously reported cases in the literature. This case emphasises that when a fracture is detected around an elbow there should be a high index of suspicion for other injuries in the region.     

Conference report: Bio-International 2005

This is a summary report of the International Pharmaceutical Federation/Board of Pharmaceutical Sciences (FIP/BPS) international conference, Bio-International 2005, which was held October 24-26, 2005 at the Royal Pharmaceutical Society, in London, UK. Bioequivalence (BE) issues related to multisource locally delivered topical dosage forms, oral inhalation drug products, highly variable drug products (HVDP), and endogenously occurring drugs were discussed. The conference also focused on alternate approaches to assess BE for some of these drug products. Pharmacokinetic (PK) approaches like, dermatopharmacokinetics (DPK) for dermatological topical dosage forms, scaled average BE (s-ABE) where within-subject variability is considered for estimation of 90% confidence intervals to document BE for highly variable drugs (HVD) were recommended. In addition, issues and difficulties related to the BE assessment of oral inhalation products, role, and appropriateness of metabolites in BE assessment, importance of base line correction in BE assessment of endogenously occurring drugs, and waiver of BE study requirements for certain drugs based on a Biopharmaceutics Classification System (BCS), were also discussed.     

Pharmacokinetics and brain penetration study of chlorogenic acid in rats

1. The present study is designed to investigate the brain distribution and plasma pharmacokinetics profiles of chlorogenic acid (CGA) after intranasal administration in Charles–Foster rats to evaluate whether the CGA molecules are transported directly via the nose-to-brain path.

2. The CGA is administered intravenously (IV) and intranasally (IN) at the dose of 10?mg/kg. Further, its concentration in the plasma, cerebrospinal fluid (CSF) and the whole brain is analyzed by HPLC-UV method.

3. The study observes that CGA is rapidly absorbed in plasma with t_max of 1?min similar to IV route after IN administration. The peak plasma concentration and AUC_0–24 are higher by 3.5 and 4.0 times respectively in IV administration, compared to IN delivery that represents the significant less systemic exposure of CGA in IN route.

4. However, the concentration of CGA in the brain is 4, 6.5, 5.3, 5.2 and 4.5 times higher at 30, 60, 120, 240 and 360?min, respectively in IN administration compared to IV administration. The exposure of CGA in the brain after IN administration (AUC_{brain, IN}) was significantly greater (4 times) as compared to the exposure of CGA in the brain (AUC_{brain, IV}) after IV administration reflecting significant brain uptake of CGA through nasal route. Therefore, IN delivery of CGA can be a promising approach for the treatment of stroke and neurodegenerative disorders.     

Surgical considerations for ‘intrinsic＇ brainstem gliomas： proposal of a modification in classification

BACKGROUND： Brainstem gliomas are highly heterogeneous tumors both in their clinical manifestation and in their pathology. Despite significant advances in the surgery for brainstem gliomas many aspects of this pathology are still unelear. OBJECTIVE： To evaluate the clinical, radiological and surgical outcome of 40 focal ＂intrinsic＂ brainstem gliomas and propose a surgical strategyoriented classification. MATERIALS AND METHODS： A total of 40 focal ‘intrinsie’ （＂expanding variety＂） tumors have been operated over a period of 8.5-years （January 1998-June 2007）. Our criteria included patients with （1） well-defined gadolinium enhancing tumor, （2） relatively long duration of symptoms （〉 six months） and （3） good neurological functional status and independent for all activities of davy living. The cutoff size of 2 cm was not rigidly adhered to. RESULTS： The ＂intrinsic＂ brainstem tumors were classified into three types： Expanding, diffuse infiltrative and pure ventral varieties.