Homeostasis of periodontal ligament : emphasis on chemotaxis of preosteoclasts due to masticatory stimulation

1.采用计算力学方法计算了金黄地鼠颊囊单个微血管模型的血管内切应力。根据弹性静力学和流体力学分析的结果，变形血管中产生的剪应力在变形部分的上下游都明显增加，并且不仅由于血流的变化，而且由于血管壁的压缩或弯曲而产生强烈的应力。(颌面部生物力学第三卷，1997)2.我们利用活体显微镜观察了仓鼠颊囊单个毛细血管后小静脉，并定量测量了血管变形时血液中含有流动的破骨前细胞的白细胞的移动情况。结果表明，在50微米的范围内，上下游的白细胞滚动和黏附增加。此外，如果我们将一只年轻的动物和一只年老的动物进行比较，Roll…更多的粘合和粘合的老。与年轻动物相比，动物由于变形而导致的白细胞减少，很明显，老年动物从这种反应(滚动和粘连)中恢复的速度比年轻动物慢得多。(J.Jpn.Orthod.Soc.为了阐明间歇性机械刺激对血管的影响，我们用免疫组织化学的方法，对去咬合力和有咬合功能两种状态下大鼠磨牙牙周膜微血管的变化进行了定量研究。因此，我们可以推断，一旦去除机械刺激，微血管直径将在3个月内减小，血管数量也将减少到有统计学意义的程度。(Orthod Waves Vol.57,1998)4.我们对大鼠磨牙的牙周韧带进行了组织学检查，以观察氧化他兰纤维老化的变化。因此，我们可以看到，由于老化效应，氧化他兰纤维的方向的复杂性和不规则性都增加了。(《牙科学杂志》第46卷，1999)

1. We used computed mechanical method to calculate the intravascular shear stress of a single microvasculature model in cheek pouch of a hamster. According to the results from elastic static and fluid mechanics analyses, shear stress generated in a deformed blood vessel obviously increased at both the upstream and downstream of the deformed part, and we could see that stress strongly occurred not only due to change in blood flow but to the compression or bending of the blood vessel walls. (Maxillofacial Biomechanics Vol.3, 1997)2. We utilized an intra-vital microscopy to observe a single postcapillary venule of a hamster's cheekl pouch and to quantitatively measure the mobility situation of leukocytes, containing flowing preosteoclasts in blood stream, under deformation of blood vessels. As a result, the rolling and adhesion of leukocytes increased within the range of 5Oum at the upstream and downstream could be seen. In addition, if we compared a young animal with an old one, the roll … More ing and adhesion of the old. animal's leukocytes due to deformation decreased in comparison with those of a young one, and it was clear to see the recovery from this reaction (the rolling and adhesion) of the old animal was much slower than what could be seen from the young one. (J.Jpn.Orthod.Soc. Vol.56, 1997)3. With a view to clarifying the influence of the intermittent mechanical stimulation onto blood vessels, we quantitatively measured the change of microvasculature of periodontal ligament of a rat molar in two conditions, with removal of occlusal force and with occlusal function, by means of immunohistological approach for 3 months. As a result, we may infer that once mechanical stimulation was removed, the diameter of microvasculature will decrease and the number of blood vessels will also decrease to a statistically meaningful degree in 3 months. (Orthod Waves Vol.57, 1998)4. We histologically examined the periodontal ligament of a rat molar to see the change in aging of oxytalan fibers. As a result, we may see both the complexity and irregularity of the direction of oxytalan fibers increased owing to aging effect. (J.Med.Dent.Sci.Vol.46,1999) Less