探讨四环素2雌酚酮（XW630）是否对实验性骨折愈合具有促进作用。在120只新西兰大白兔实验性桡骨骨折愈合过程中给予XW630、雌酚酮（E2）、四环素（T）和生理盐水（对照组C）治疗；采用肌肉注射与伤口局部两种给药方式。测定了骨折术后30天、60天和90天愈合骨的弯曲和压缩强度，以及骨折局部骨痂中胶原和钙的含量。结果显示：在各不同时段，XW630肌注组兔桡骨的抗弯能力与抗压能力明显高于其它各组。在骨折后30天，其弯曲破坏极限的增加最为明显。分别比C组、E2组和T组高出80%、76%和69%。而在骨折后90天，XW630肌注组的桡骨弯曲破坏极限已达正常的80%，分别比C组、E2和T组高出30%、34% 和1915%。骨痂胶原含量和骨钙含量的变化与骨抗弯曲能力的变化一致。说明XW 630肌肉注射具有明显的促进骨折愈合的作用。采用局部给药方式其各组间无明显差异。在同一时段相同药物组中，肌肉注射给药方式对骨折愈合的作用明显优于局部给药方式。

目的 对比研究3、6、9、12个月龄大鼠的骨髓基质细胞白细胞（marrow stromal cdls，Mscs）成骨与成脂肪能力的变化。方法 培养液中分别加入成骨、成脂肪诱导剂，在不同时间行细胞化学染色观察3和12个月龄两组大鼠MScs的成骨与成脂肪能力的变化；采用RT PcR法分别检测3、6、9、12个月龄大鼠的MScs的I型胶原mRNA和脂蛋白脂酶mRNA水平的变化。结果 成骨诱导1周后，12个月龄大鼠的MScs对照与诱导组碱性磷酸酶（alkaline phosphatase，ALP）表达阳性率均低于3个月龄大鼠的同组细胞。成骨诱导12 d后，3个月龄大鼠组的MScs先于12个月龄大鼠组形成钙化。成脂肪诱导第2天，12个月龄大鼠组的MScs先于3个月龄大鼠组MScs生成脂滴。RT PcR检测显示I型胶原mRNA水平随月龄增长表达降低，且随诱导时间延长降低幅度变大；脂蛋白脂酶的mRNA水平随月龄增长表达增加，随诱导时间延长增加幅度变大。结论大鼠的MScs随月龄增长成骨能力降低，成脂肪能力增强。

The steady state non-Newtonian viscosity of whole human blood has been widely studied as a function of the shear rate; and used to characterize the blood in various pathological disorders. In our previous studies, we demonstrated that blood is a thixotropic fluid. Its time-dependency and shear rate dependency of rheological behavior can be represented by an equation developed by Huang. Parameters of the equation can be used for the characterization of an individual's blood. They provide information, such as the kinetic rate constant of breakdown of RBC rouleaux to individual erythrocytes and the relative amount of rouleau formation in the dynamic equilibrium between rouleaux and individual erythrocytes. In this communication, the thixotropic parameters from blood samples of fifteen apparently healthy human subjects were investigated. When compared to the use of apparent viscosity values for the correlation with a pathological disorder, thixotropic parameters are preferable. The mean values of thixotropic parameters obtained from apparently healthy human subjects provide a base for comparison with the same parameters as obtained from blood samples of patients with certain pathological disorders involving the circulation.

We studied hemor-heologic alterations in acute pancreatitis in 2g dogs to find out that during the early stage of induction of acute necrotizing pancrea-tiffs, all the hemorheologic parameters were signifi-cantly elevated, and continued to increase at the restintervals but no difference between the acute in-terstitial pancreatitis and control groups. We suggest that increased blood viscosity and tendency of ery-throeytes to aggregate with rouleaux formation are the causes of microeirculatory thrombosis in pan-creas. They may be th key factors in the patbo. genesis of pancreatic necrosis in acute necrotizing pancreatitis.

We investigated neutrophil activation, specifically F-actin content and distribution, in situations mimicking the in vivo environment using steady and oscillatory shear. Under low steady shear (<150 s−1) F-actin levels were decreased for both treated (n-formyl-L-methioryl-L-leucyl-L-phenylalanine (fMLP)) and untreated neutrophils. The F-actin content increased with a change to higher steady shear levels. Neutrophils show the same behavior of decreased F-actin content for oscillatory shear (26.7 s−1) as they did for steady shear. In both situations, the low shear levels caused a decrease in F-actin content. However, as the magnitude of the shear rate increased, cells showed a reversal to increasing F-actin content. Shear caused a decrease in F-actin in the cell cortex for both control and fMLP treated cells. Ctyochalasin B (CB), a common F-actin assembly blocker, significantly decreased F-actin content. The results indicate that neutrophils regulate their actin network based on the level and type of shear stress they encounter in the bloodstream.