家兔动脉成形术后血管内膜增殖与普伐他汀联合阿司匹林的干预效应

目的:观察普伐他汀、阿司匹林联用对家兔颈动脉血管成形术后内膜增殖进展的影响及其作用机制。方法:实验于2002-03/12在北京中医药大学教育部中医内科学重点学科实验室完成。雄性日本大耳白兔30只,体质量1.8～2.0kg,动物适应性喂养1周后随机数字表法分为正常对照组(n=9)、假手术组(n=6)、模型组(n=9)、治疗组(n=6)。模型组和治疗组动物氯胺酮、速眠新混合肌注麻醉,沿气管正中切开皮肤,剥离颈总动脉,给予电刺激。术后第2天开始饲喂高脂饲料(胆固醇:0.7%,猪油:3%,普通饲料96.3%);正常对照组无任何干预措施;假手术组仅剥离颈总动脉,不做电刺激,喂高脂饲料;动物连续喂养8周后超声评价颈总动脉,根据B超选择颈总动脉有斑块或血流明显改变者作颈总动脉球囊扩张术。正常对照组、模型组、假手术组喂普通饲料,治疗组喂普伐他汀与阿司匹林含药饲料(普伐他汀5.046mg/kg,阿司匹林2.268g/kg),4周后测血脂和C-反应蛋白浓度、血清一氧化氮及转化生长因子β水平,观察颈动脉组织病理形态学改变,半定量分析增生内膜中胶原含量的变化,免疫组织化学方法分析增生内膜中巨噬细胞和平滑肌细胞阳性百分率。结果:纳入大耳白兔30只,正常对照组中途死亡1只,死因为牙齿畸型影响进食;模型组1只因电刺激8周时超声评价颈动脉未形成斑块及血流无明显改变而剔出实验,进入分析28只。与模型组比,普伐他汀与阿司匹林联用4周后,治疗组胆固醇及三酰甘油水平明显下降[(4.12±2.30),(0.74±0.17)mmol/L;(0.47±0.27),(0.39±0.14)mmol/L;P<0.05],血清C-反应蛋白水平和转化生长因子β水平均降低[(0.86±0.27),(0.57±0.30)mg/L;(3.45±0.77),(3.23±0.34)ng/L;P<0.05],一氧化氮水平升高[(41.79±35.78),(90.14±32.54)mmol/L;P<0.05],动脉内膜增殖程度明显减轻,管腔狭窄率降低,内中膜厚度及内中膜面积比降低[(71.91±14.90)%,(47.20±18.74)%;(0.41±0.17),(0.26±0.04)mm;1.66±0.63,0.78±0.34;P均<0.05],动脉内膜胶原含量减少(30.92±10.05,21.93±5.81,P<0.01),动脉内膜巨噬细胞阳性百分率降低[(13.94±4.91)%,(7.29±7.28)%,P<0.05],平滑肌细胞含量无明显差异(38.37±5.67,35.79±10.68,P>0.05)。结论:普伐他汀与阿司匹林联用具有抑制内膜增生和减少新生内膜胶原含量的作用,其机制与两药抑制炎症反应、保护内皮功能及抑制细胞外基质生成等有关。     

含砷矿物药在体内存在形态的研究方法

含砷矿物药数量较多，仅中国药典１９９５版中含雄黄的复方就有２３种之多。砷类药物如雄黄、雌黄、砒石、砒霜、鬻石是这些复方药效的物质基础［１］。不同形态的砷毒性不同，如Ａｓ３＋毒性最大，而Ａｓ５＋毒性降低为Ａｓ３＋的１７％，甲基砷类毒性更弱，砷甜菜碱类...     

Study of the radio-opacity of base and liner dental materials using a digital radiography system

Objectives:

This study investigated the radio-opacity of commercially available glass ionomer cements (GICs), flowable resin composites (FRCs) and calcium hydroxide cements (CHCs) and compared this with the radio-opacity of enamel, dentine and aluminium stepwedge. 16 GICs, 8 FRCs and 4 CHCs were analysed.

Methods:

Three sets of three samples were prepared: 1 mm, 2 mm and 3 mm thickness for GIC and FRC and 1 mm thickness for CHC. Specimens of enamel and dentine with the same thicknesses were obtained. As a control, an aluminium stepwedge was used. Radiographs were taken with a digital Kodak RVG 5000 (0.32 s, 30 cm). The images were analysed using the Image Tool^® program (v. 2.00; The University of Texas Health Science Center, San Antonio, TV) to obtain the mean grey values.

Results:

Analysis of variance was used to investigate the significance of differences among the groups. For pairwise comparisons, the Tukey test was applied (p < 0.05). The GICs Ionomaster (Wilcos, Petrópolis, Brazil), Maxxion (FGM, Joinville, Brazil), Bioglass R (Biodinâmica, Ibiporã, Brazil), Bioglass F (Biodinâmica), Vidrion R (SS White, Rio de Janerio, Brazil) and Vidrion F (SS White), presented radio-opacity lower than that of dentine. All FRCs and CHCs studied showed radio-opacity higher than that of dentine. Vitro Fil (DFL, Rio de Janeiro, Brazil), Magic Glass (Vigodent, Rio de Janeiro, Brazil), Vitrebond (3M, Sumaré SP, Brazil), Riva Self Cure (SDI, Victoria, Australia), Riva Light Cure (SDI), Fill Magic (Vigodent), Opallis (FGM, Joinville, Brazil), Surefil SDR (Dentsply, Milford, DE), Tetric N (Ivoclar Vivadent, Schaan, Lichtenstein), Tetric (Ivoclar Vivadent), Hydro C (Dentsply, Petrópolis, Brazil), Hydcal (Technew, Madalena, Portugal) and Liner (Vigodent) showed radio-opacity similar to or greater than that of enamel for all thicknesses.

Conclusions:

The increased thickness of the materials studied increases their radio-opacity. Some commercially available GICs used as a base and liner for restorations have a very low radio-opacity (Ionomaster, Maxxion, Bioglass R, Bioglass F, Vidrion R and Vidrion F).     

抗三尖杉酯碱HL-60细胞的抗程序性细胞死亡及其克服

三尖杉酯碱(harringtonin,HT)是中国产植物海南粗榧(Cephalotaxus hainanensis Li)中提取的一种抗肿瘤药物,对急性粒细胞白血病、急性单核细胞白血病有较好疗效⁽¹⁾。三尖杉酯碱可非常有效地诱导敏感HL-60细胞程序性死亡(apoptosis,Apo)^(2,3)。但超过半致死剂量(IC₅₀)近百倍的HT却不能诱导抗三尖杉酯碱细胞HT12程序性死亡。如用维拉帕米(verapamil,Vp)10μg·mL^-1逆转多药抗性后,HT虽可诱导HT12细胞程序性死亡,但与敏感细胞相比,出现程序性细胞死亡的时间大大推迟,用药浓度也提高约10倍。这些结果提示:程序性细胞死亡可能作为肿瘤细胞是否已形成抗药性的标志之一,同时也说明程序性细胞死亡相关因子可能参与肿瘤细胞抗药性的形成。     

Retrograde endopyelotomy: a comparative study of hot-wire balloon and ureteroscopic laser

PURPOSE: This study compared the immediate and long-term results and complications of hot-wire balloon endopyelotomy and ureteroscopic holmium laser endopyelotomy. PATIENTS AND METHODS: Between March 1994 and January 2002, 64 patients with a primary (N = 52) or secondary (N = 12) ureteropelvic junction obstruction underwent retrograde endopyelotomy using either a fluoroscopically guided hot-wire balloon incision (N = 27) or a ureteroscopically guided, direct-vision holmium laser incision (N = 37). This study group included 46 women and 18 men aged 13 to 79 years (mean 38.9 years). The indications and contraindications to a retrograde approach were identical in each group and included documented functionally significant evidence of obstruction, no upper-tract stones, obstruction <2 cm, and no radiographic evidence of entanglement of crossing vessels at the ureteropelvic junction. Immediate and long-term outcomes were obtained from a prospective registry, with success defined as resolution of symptoms and radiographic relief of obstruction as determined by follow-up with intravenous urography, diuretic renography, or both. Follow-up ranged from 39 to 133 months (mean 75.6 months). RESULTS: Length of hospital stay, indwelling stent duration, and long-term success rates (77.8% v 74.2% in the hot-wire balloon and holmium-laser group, respectively) were equivalent. However, two patients in the hot-wire balloon group developed bleeding necessitating transfusion and selective embolization of lower-pole vessels. No patient in the ureteroscopic group suffered a major complication. CONCLUSIONS: These two alternatives for retrograde endopyelotomy provide comparable success rates for similarly selected patients. However, because significant hemorrhagic complications developed with greater frequency in those treated with the hot-wire balloon, our preference is for a ureteroscopic approach, as it allows direct visual control of the incision and thus, a lower risk of significant bleeding.