组织工程注射骨的体外实验研究

目的 :探索骨髓间充质细胞在纤维胶内体外成骨的可行性。方法 :5× 10 6～ 10× 10 6细胞 /毫升的骨髓间充质细胞植入前行细胞活力测定 ;植入纤维胶 ,体外培养 60 d后进行组织学、免疫组织化学分析。结果 :细胞在纤维胶内产生大量的特异性 型胶原 ,并有大量的钙质沉着。结论 :骨髓间充质细胞在纤维胶内可在体外培养的环境下生成大量的骨基质。     

补中益气汤对环磷酰胺致骨质疏松小鼠骨生物力学的影响

目的:观察环磷酰胺对小鼠骨生物力学的影响,观察补中益气汤和葡萄糖酸钙对环磷酰胺造成的小鼠骨质疏松的防治作用。方法:实验于2005-10/2006-01在广东医学院药理教研室完成。选取昆明种小鼠40只,体质量(20±2)g,雌雄各半,按体质量对等原则随机分为4组,正常对照组、环磷酰胺模型组、环磷酰胺合用补中益气汤组、环磷酰胺合用葡萄糖酸钙组,每组10只。补中益气汤的制备:称取炙黄芪200g,党参60g,炙甘草100g,白术60g,当归60g,升麻60g,柴胡60g,陈皮60g,切碎,加水煎煮2次,滤过,滤液浓缩至1700mL,冰箱保存备用。正常对照组灌胃给予生理盐水10mL/(kg·d),环磷酰胺模型组灌胃给予环磷酰胺20mg/(kg·d);环磷酰胺合用补中益气汤组灌胃给予环磷酰胺20mg/(kg·d)的同时灌胃给予补中益气汤20mL/(kg·d);环磷酰胺合用葡萄糖酸钙组灌胃给予环磷酰胺20mg/(kg·d)的同时灌胃给予葡萄糖酸钙0.5mg/(kg·d)。均自由饮水和进食标准饲料。于实验第30天称质量后,处死动物,取肝脏、脾脏、胸腺称质量,根据动物体质量计算器官指数,同时取右侧股骨供骨生物力学测定用。结果:40只小鼠均进入结果分析。与正常对照组比较,环磷酰胺模型组骨生物力学指标最大载荷、弹性载荷、刚度系数均减少[(12.11±2.06)N,(8.15±2.57)N,(45.89±6.33)N/mm;(14.98±1.54)N,(10.17±1.17)N,(56.34±9.49)N/mm,P<0.05,P<0.01]。与环磷酰胺模型组比较,环磷酰胺合用补中益气汤组、环磷酰胺合用葡萄糖酸钙组生物力学指标最大载荷、刚度系数增高[环磷酰胺模型组:(12.11±2.06)N,(45.89±6.33)N/mm;环磷酰胺合用补中益气汤组:(15.52±2.67)N,(57.68±11.19)N/mm;环磷酰胺合用葡萄糖酸钙组:(17.10±2.96)N,(63.69±11.11)N/mm,P<0.05,P<0.01]。与环磷酰胺合用葡萄糖酸钙组比较,环磷酰胺合用补中益气组表现为各生物力学指标与环磷酰胺合用葡萄糖酸钙组相似,差异无显著性意义。结论:环磷酰胺能使小鼠骨结构性质和材料性质下降,补中益气汤和葡萄糖酸钙均能对抗环磷酰胺导致的骨质量下降,预防骨质疏松。     

Phosphine-Induced Oxidative Stress in Hepa 1c1c7 Cells

Phosphine (PH₃), from hydrolysis of metal phosphides, is animportant insecticide (aluminum phosphide) and rodenticide (zincphosphide) and is considered genotoxic and cytotoxic in mammals.This study tests the hypothesis that PH₃-induced genotoxicityand cytotoxicity are associated with oxidative stress by examiningliver (Hepa 1c1c7) cells for possible relationships among celldeath, increases in reactive oxygen species (ROS) and lipidperoxidation, and elevated 8-hydroxyguanine (8-OH-Gua) in DNA.PH₃ was generated from 0.5 mM magnesium phosphide (Mg₃P₂ togive 1 mM PH₃ as the nominal and maximal concentration. Thislevel causes 31% cell death at 6 h, measured by lactate dehydrogenaseleakage, with appropriate dependence on concentration and time.The intracellular ROS level is elevated within 0.5 h followingexposure to PH₃, peaking at 235% of the control by about 1 h.Lipid peroxidation (measured as malondialdehyde plus 4-hydroxyalkenals)is increased up to 504% by PH₃ at 6 h in a time-dependent manner.The level of 8-OH-Gua in DNA, a biomarker of mutagenic oxidativeDNA damage analyzed by GC/MS, increases to 259% at 6 h afterPH₃ treatment. Antioxidants significantly attenuate the PH₃-inducedROS formation, lipid peroxidation, 8-OH-Gua formation in DNA,and cell death, with the general order for effectiveness ofGSH (5 mM) and D-mannitol (10 mM) (hydroxyl radical scavengers),then Tempol (2.5 mM) and sodium azide (3 mM) (superoxide anionand singlet oxygen scavengers, respectively). These studiessupport the hypothesis that PH₃-induced mutagenic and cytotoxiceffects are due to increased ROS levels, probably hydroxyl radicals,initiating Oxidative damage.     

出生后5年内环境和饮食干预不能降低哮喘和过敏性疾病发病风险

问题：在出生后的最初5年，减少房屋尘螨（HDM）变应原暴露并改变饮食中脂肪酸构成是否可以降低5岁时发生哮喘的风险？     

P-31 MR spectroscopy of normal human brain and brain tumors

Image-guided phosphorus-31 magnetic resonance (MR)-localized image-selected in vivo spectroscopy was performed on normal human brain and brain tumors. Peak area ratios, absolute molar concentrations of metabolites, and pH were determined. T1 values in normal brain were measured. The most important finding was that the metabolite concentrations detectable with MR spectroscopy in brain tumors were reduced from 20% to 70%. Phosphomonoesters, phosphodiesters, and phosphocreatine (PCr) showed the greatest decreases, while inorganic phosphate (Pi) showed the least change. The PCr-Pi ratio was significantly reduced in tumors. The pH of brain tumors (7.12 +/- 0.03) was more alkaline than that of normal brain (6.99 +/- 0.01). The authors conclude that the metabolite concentrations and pH in human brain tumors differ significantly from those in normal brain. These differences may be ultimately useful in characterizing tumors in man.     

Edge enhancement of ECG-gated cardiac images using directional masks

ECG-gated images were processed by a computer using a nonlinear digital filter and directional masks to improve delineation of cardiac chamber boundaries and identification of the aortic and mitral valve planes. This technique proved to be satisfactory in 30 patients with documented coronary or valvular heart disease.