持续性正加速度致意识丧失的机理及其监测

正在加速度引起的意识丧失（Ｇ－ＬＯＣ）是当胶威胁飞行安全的主要因素。综述了Ｇ＿ＬＯＣ的机理及其生理监测,慢增长率正加速度导致的意识丧失的机理主要大脑缺血／缺氧;快增长率正加速度导致物意识丧失可能与颅内高应力有关,但缺直接的实验证据。用于Ｇ－ＬＯＣ监测的生理指标中,眼水平动脉血压、脑氧饱和度等可能具有重要作用。     

人肝细胞癌细胞系HCC-9903的建立及其生物学特性研究

目的 新建1株人体肝细胞肝癌细胞系,为肝癌研究提供新的、理想的实验模型。方法 以手术切除肝癌标本作原代培养,建立细胞系。通过光镜、电镜、倍增时间、生长曲线、双层软琼脂培养、流式细胞仪、染色体分析、刀豆球蛋白凝集试验、裸鼠接种、AFP、HBV及端粒酶检测,对其生物学特性进行分析。结果 第29天完成原代培养。形态学、增殖动力学及浸润性生长结果表明该细胞系符合恶性细胞特征。染色体数目分布在49－135,众数为60－67,1q^(i)和t(6,11)等为其标记染色体;有四射体和核内复制出现。裸鼠接种成瘤,瘤细胞形态与原病人的病理切片相似。端粒酶检测强阳性。结论 该细胞系符合建系标准,是1株新建的人体肝细胞肝癌细胞系,命名为HCC－9903。其生物学特性研究内容及检测手段较国内外已建肝恶性肿瘤细胞系更为全面。     

青春期大鼠左侧精索静脉的解剖变异及其在实验性左侧精索静脉曲张模型中的运用

目的:探索青春期大鼠左侧精索静脉(LSV)解剖变异对诱导实验性左侧精索静脉曲张(ELV)的影响。方法:将30只雄性青春期SD大鼠随机分成3组,每组10只。A组缩窄左肾静脉并结扎LSV侧支,B组仅缩窄左肾静脉,C组为假手术组。观察LSV走行,测量其直径。术后30 d分析左肾大体和组织学变化,并再次测量LSV直径。结果:大鼠LSV 90%存在不规律出现的侧支,仅10%无侧支。术后各组左肾未见异常。A、B、C组LSV直径术前和术后分别为(0.16±0.08)mm和(1.47±0.15)mm、(0.15±0.07)mm和(0.31±0.49)mm、(0.16±0.06)mm和(0.17±0.07)mm。A组术后直径较术前明显增粗(P0.01),B组和C组均无统计学差异(P均0.05)。术后LSV直径A组明显大于B组(P0.01)。A组ELV诱导成功率为100%,B组为10%(仅1只LSV无侧支的大鼠造模成功),C组未见曲张。结论:认清LSV解剖回流,并结扎其不规律出现的侧支是建立稳定一致的ELV模型的关键。     

Development of left ventricular hypertrophy in a novel porcine model of mitral regurgitation

Objectives. We aimed to develop a porcine model for chronic nonischemic mitral regurgitation (MR) to investigate left ventricular (LV) enlargement and eccentric hypertrophy. Design. Nonischemic MR was induced in 30 pigs by open-chest immobilization of the posterior mitral leaflet by transannular traction sutures that where applied in transmyocardial fashion. A sham operated control group (n = 13) was included. Echocardiographic LV size and heart weight assessed at euthanasia were used to evaluate the development of LV enlargement and eccentric hypertrophy after 8 weeks follow-up. Results. Eight pigs died and seven were excluded due to mediastinal infection (n = 2) or failure to produce MR (n = 5). Thus, 28 pigs were included and were divided into three groups: controls (n = 12), mild MR (mMR; n = 10), and moderate to severe MR (sMR; n = 6). The change in LV internal diameter in diastole (LVIDd) from baseline to follow-up was significantly higher in the sMR group compared to that of the control group (P = 0.0017). Furthermore, LV weight was significantly increased in the mMR (P = 0.047) and the sMR (P = 0.0087) groups compared to that of the control group. Conclusions. A new model for chronic moderate to severe nonischemic MR with development of LV enlargement and eccentric hypertrophy within 8 weeks has been established in pigs.     

Th1/Th2细胞因子在眼肌型重症肌无力转基因小鼠模型中的作用机制

目的 观察重组人乙酰胆碱受体(H-AChR) γ亚单位免疫HLA-DQ8转基因小鼠眼肌型实验性自身免疫性重症肌无力(oEAMG)模型体外培养上清液中Th1/Th2细胞因子水平变化,探讨其与oEAMG免疫学发病机制的联系。方法 HLA-DQ8转基因小鼠用乳化于完全弗氏佐剂(CFA)的重组H-AChR γ亚单位,或E. Coli提取物,或纯CFA分别免疫,分别于第0天、第30天和第60天共免疫3次。第3次免疫后28 d,处死小鼠后取淋巴结和脾淋巴细胞体外培养,收集培养上清液,采用ELISA法检测白细胞介素(IL)-2、γ-干扰素(IFN-γ)、IL-6和IL-10水平。结果 H-AChR γ组小鼠淋巴结及脾淋巴细胞体外培养上清液中IL-2(F=42.835,P<0.001;F=38.030,P<0.001)和INF-γ水平(F=76.332,P<0.001;F=34.865,P<0.001)均明显高于E. coli组和CFA免疫组;IL-6(F=1.325,P=0.284;F=1.935,P=0.166)和IL-10水平(F=0.908,P=0.417;F=1.189,P=0.322)与E. coli 组和CFA组差异无统计学意义。结论 Th1细胞因子在重组H-AChR γ亚单位诱导HLA-DQ8转基因小鼠所建立oEAMG模型的发病机制中可能发挥重要作用,而Th2细胞及其细胞因子作用尚不十分明确。     

MRI detection of myocardial perfusion defects due to coronary artery stenosis with MS-325

PURPOSE: To assess the value of an intravascular, albumin-targeted contrast agent, MS-325, in visualizing myocardial ischemia with magnetic resonance imaging (MRI). MATERIALS and METHODS: Left anterior descending coronary artery (LAD) stenosis was created in 19 pigs using a closed-chest modified angioplasty technique. Myocardial ischemia was detected by first-pass, contrast-enhanced MRI at peak dipyridamole stress and was compared to Technetium-99m (Tc-99m) sestamibi single photon emission computed tomography (SPECT). Regional coronary blood flow was determined using microspheres. RESULTS: Inducible myocardial ischemia with >40% reduction in stress myocardial blood flow was created in eight animals. An MRI defect, classified as > or=75% reduction in peak myocardial signal intensity in the affected territory, was detected in 92.3% of these animals. In the presence of mild coronary stenosis, there was uniform enhancement with MRI and tracer uptake by SPECT. Concordance of MRI and SPECT for detecting perfusion defects was 85%. CONCLUSION: The pattern of prolonged and persistent MR hypoenhancement of the ischemic myocardial bed using MS-325, which is retained primarily in the vascular bed due to its albumin-binding properties, facilitates the detection of myocardial perfusion defects.     

螺旋CT肺动脉造影诊断肺小动脉血栓的实验研究

目的：评价螺旋CT肺动脉造影（spiral CT pulmonary angiography，CTPA）诊断犬肺小动脉血栓栓子（直径2.5-3.5mm）的应用价值。方法：23条实验犬行CTPA空白对照后，制成犬自体血块肺动脉栓塞模型，先后行CTPA与X线肺动脉造影（X-ray pulmonary angiography，XPA）检查，由2名医生在工作站上分析所获图像，并与犬肺病理解剖结果对照，评价CTPA与XPA对肺动脉血栓栓塞的诊断价值。结果：22条犬完成实验全过程，病理解剖发现肺动脉内栓子110个，与人工注入栓子数目相符，均位于肺动脉的段或亚段水平，其中107个位于扫描野内。CTPA发现栓子90个，诊断肺动脉内小血栓栓子的敏感度为84.1％，阳性预测值为93.8％；XPA发现栓子82个，敏感度为76.6％，阳性预测值为94.3％。结论：CTPA对实验性肺小动脉血栓栓子有较高的诊断价值。     

卵圆细胞参与实验性肝癌形成过程的研究

目的探讨卵圆细胞在肝组织内的起源及其与原发性肝细胞肝癌的关系。方法清洁型SD大鼠60只,随机分为正常组(20只)和实验组(40只),各组于开始制造肝癌模型后的不同时段取肝组织标本进行常规病理和C-kit、PCNA免疫组化检测。结果正常组大鼠肝脏表面光滑,组织学形态正常,偶见C-kit和PCNA阳性细胞;实验组于肝脏染毒的第2周,首先于汇管区发现卵圆细胞沿胆管上皮依次排列增生,这些卵圆细胞呈C-kit和PCNA阳性表达。随着染毒加重,卵圆细胞以汇管区为中心向肝小叶穿插生长。肝癌形成时,癌结节内外均见有卵圆细胞聚集,此期c-kit阳性细胞仍以汇管区为主,而PCNA阳性细胞遍布癌结节内外。结论卵圆细胞起源于汇管区的胆管上皮;卵圆细胞与肝癌的发生密切相关。     

脂质体生存素反义寡核苷酸抑制胃癌裸鼠皮下移植瘤生长的作用

目的探讨脂质体生存素反义寡核苷酸(ASODN)对人胃癌裸鼠皮下移植瘤生长的抑制作用及机理。方法将24只裸鼠建立人胃癌细胞系HS-746T皮下移植瘤模型,用不同的转染液处理后随机分成6组：空白对照组,脂质体组,正义链组,100、200和400nmol／L反义链组(ASODN组)。于注射相应试剂后2,4,8,12,16,20d观测裸鼠移植瘤体积,计算抑瘤率和肿瘤缩小率,观察移植瘤细胞形态变化,免疫组化SP法检测生存素的表达,并用逆转录聚合酶链反应技术(RT—PCR)和Western blot蛋白免疫印迹法比较治疗后不同时间各组肿瘤组织中生存素mRNA和蛋白表达的变化。结果注射后20d空白组、脂质体组和正义链组裸鼠的抑瘤率无明显差异,而ASODN组移植瘤的体积随着时间和浓度的增加而减小,肿瘤缩小率则增大,抑瘤率均大于对照组,400nmol／LASODN组抑瘤率最大为93％。光镜下见ASODN组移植瘤凋亡细胞数增多,生存素表达减弱,6例(6／12)肿瘤组织有坏死液化灶。各ASODN组均能够下调移植瘤细胞生存素mRNA含量,抑制生存素蛋白表达,注射20d后400nmol／L ASODN组蛋白表达为空白对照组的36．8％。结论生存素基因反义寡核苷酸能够通过诱导人胃癌裸鼠皮下移植瘤细胞凋亡,下调生存素mRNA和蛋白的表达,抑制裸鼠皮下移植瘤的生长。     

Effects of pneumoperitoneum with or without colostomy on rat colonic anastomotic healing

Background: Elevated intra‐abdominal pressure and colostomy have adverse effects on colonic anastomoses. The aim of the present study was to investigate the effects of laparoscopic colon surgery with and without diverting colostomy on healing of colonic anastomoses in an experimental model. Methods: Thirty‐six male rats were divided into three equal groups: group 1, control (colonic anastomosis and anaesthesia for 180 min only); group 2, 180 min pneumoperitoneum and colonic anastomosis; and group 3, similar to group 2 with a proximal colostomy. On day 7, bursting pressures, tissue hydroxyproline and nitric oxide concentrations and histopathological inflammation scores were determined and compared. Results: Mean bursting pressures were higher in the control group than the two pneumoperitoneum groups (P = 0.0003). Mean tissue hydroxyproline concentrations showed no difference (P > 0.05). Mean tissue nitric oxide concentrations were significantly increased in the control group (P = 0.0013). Histopathological scores demonstrated increased inflammatory response in group 3 compared to the controls (P = 0.0009). Conclusion: Pneumoperitoneum delays collagen maturation and impairs anastomotic strength in the colon. Following pneumoperitoneum, performance of a diverting loop colostomy to protect the anastomosis will not have additional detrimental effects on anastomotic healing.