Objective: This study in rat genioglossus muscle (GG) was designed to test the hypothesis that the effects of estrogen are at least in part, meditated directly by the estrogen receptors (ERs) of muscle. Design: Eighty-eight-week-old female Sprague-Dawley rats were randomly assigned to five groups: (1) normal animals (Normal); (2) sham operation animals (Sham); (3) ovariectomized animals without estrogen replacement (OVX); (4) ovariectomized animals with olive oil replacement (OVX+O); (5) ovariectomized animals with 17b-estradiol replacement (OVX+E2). Six weeks later, GG was assessed in vivo for contractile properties and further analysis for ERs expression was carried out including real-time quantitative RT-PCR, immunohistochemistry and Western blotting. Results: The maximal twitch tension, 70%-decay time and fatigue index of GG decreased significantly in OVX group when compared with Normal group (P<0.05, P<0.05, P<0.05). However, all the three parameters reversed in OVX+E2 group especially fatigue index. Further analysis showed a clear expression of ERa and ERb in rat GG. The expression of both ERa protein and ERa mRNA was both significantly decreased in OVX group (P<0.05) and recovered back to previous level after receiving 17b-estradiol replacement (P<0.05). But neither ERb protein nor ERb mRNA was regulated by estrogen deprivation and replacement. Conclusion: The results demonstrated that the contractility of GG was accentuated by estrogen. Moreover, these effects were at least in part, meditated directly via regulation of the expression of ERa. It might contribute to the protective effects of estrogen on the patency of upper airway and the pathogenesis of obstructive sleep apnea hypopnoea syndrome.

This study was designed to investigate the effects of oestrogen on sarcoplasmic reticulum (SR) Ca2+-ATPase activity and gene expression in ovariectomised rats under the condition of chronic intermittent hypoxia (CIH). Thirty-two female Sprague-Dawley rats were randomly divided into four groups: the normal control group (NC), the CIH group (CIH), the CIH-ovariectomised group (CIH+OVX), and the group of CIH-ovariectomised rats receiving estradiol replacement (CIH+OVX+E2). Rats in the latter three groups were exposed to CIH for 5 weeks. The animals were killed before genioglossus (GG) was rapidly excised, and their body and uterus mass were determined. Estradiol level was detected by radioimmunoassay. SR Ca2+-ATPase (SERCA) activity was observed by detecting inorganic phosphorus ion, and the SERCA mRNA level was measured using real-time quantitative polymerase chain reaction (real-time PCR). It was found that, compared with the NC group, the SERCA activity and mRNA level were remarkably reduced (p<.01) in the CIH group. And compared with the CIH group, the SERCA activity and mRNA level were also significantly reduced (p<.01) in the CIH + OVX group. Meanwhile, the SERCA activity and mRNA level significantly increased (p<.01) in the CIH+OVX+E2 group compared with the CIH+OVX group, but lower than those in the NC group (p<.01). The results showed that CIH could reduce the SERCA activity and mRNA expression, and oestrogen-deficiency could exacerbate this effect; whilst estradiol replacement can partially reverse the effect of CIH in ovariectomised rats.

Introduction: Mandibular advancement appliances have been used for years in the treatment of obstructive sleep apnea (OSA). However, it has not been completely clarified how the upper airway changes after mandibular advancement. The purpose of this study was to examine the effects of mandibular advancement on anatomic structures of the upper airway in patients with OSA by magnetic resonance imaging. Methods: Eleven OSA patients (aged 48.0 5.86 years) with apnea and hypopnoea index values of 46.8 21.47 participated in this study. A series of magnetic resonance images was taken for each subject with a custom-made device in the mouth that could advance the mandible by 0, 2, 4, 6, and 8 mm. In addition, an image with the mandible in centric occlusion was taken. Changes in cross-sectional area, sagittal diameter, transverse diameter, and cross-sectional shape in the whole upper airway and the different regions were compared between the various amounts of mandibular advancement. Results: The minimum and mean cross-sectional area of the velopharynx and the mean transverse diameter of the velopharynx increased significantly (P 0.0001 and P 0.0016, respectively) during mandibular advancement. However, no statistically significant changes (P 0.05) in sagittal diameter were found between the various mandibular advancements. In cross-sectional shape, a significant increase (P 0.0066) was found when the mandible was advanced to 8 mm from 0 mm or centric occlusion position. Conclusions: Mandibular advancement significantly increases the cross-sectional area of the velopharynx in awake OSA patients. This contributes to the increase in its transverse dimension rather than the sagittal, thus resulting in the change of its shape.

This investigation was designed to examine whether short-term administration of sex hormones could produce changes in contractile properties and the sarcoplasmic reticulum Ca2+-ATPase (SERCA) function in genioglossal muscle (GG) of aged male rats. Twenty-four aged male rats were randomly divided into three groups to receive an intramuscular injection of either 0.1 mg/kg oestrogen (group A), 2.5 mg/kg testosterone (group B), or 0.2 ml sterile peanut oil (group C, control), twice a week, during 4 weeks. After hormone treatment, in vivo isometric contractile properties were determined using surgically prepared GG muscles with platinum electrodes for stimulation of the medial branch of the hypoglossus nerve. Sarcoplasmic reticulum Ca2+-ATPase activity was measured in muscle homogenates by detecting the amount of inorganic phosphorus ion released in a standard coupled enzyme assay. SERCA1 mRNA level was observed using a real-time quantitative reverse transcription-polymerase chain reaction (Q-RT-PCR). It was found that, compared with group C, testosterone treatment decreased the fatigue resistance in GG muscles (p<.05), whereas no change was observed in the isometric twitch (Pt) and tetanic tension (P0) (p>.05). By contrast, in oestrogen treated GG muscles, no significant modification was found either in the contractile or in endurance properties (p>.05). The change in GG fatigue resistance of group B was associated with a marked decrease in SR Ca2+-ATPase activity when compared with that of the control group (p<.01). Furthermore, SERCA1 mRNA level was also down regulated in group B (p<.05). No prominent differences in SR Ca2+-ATPase activity and SERCA1 mRNA expression existed between group A and group C (p>.05). The present results show that exogenous testosterone produces more pronounced changes in GG muscle fatigue resistance than oestrogen does by acting at SR Ca2+-ATPase activity and SERCA gene expression.

目的：调查正畸治疗导致牙根外吸收的发病情况，分析其临床特征及相关因素。方法：随机选择经直丝弓矫治技术完成的病例230例，以Levander根吸收分级法对患者全颌曲面断层片进行分析，评估矫治前后中切牙至第一磨牙的根吸收情况。结果：正畸治疗后根吸收发生率明显升高，根吸收均值（root resorption after treatment, RRAT）及根吸收增加量均值（increment of root resorption, IRR）表现为上切牙最高，拔牙组高于未拔牙组，异常根形态组高于正常根形态组。结论：正畸治疗可提高根吸收发生几率，并加重根吸收程度，此可能与拔牙与否、牙位、根形态及治疗前牙根吸收程度有关。

目的：利用CT和MRI扫描图像，探讨采用模型融合技术对颞下颌关节（TMJ）软硬组织进行三维重建的方法，为TMJ生物力学研究及其临床分析提供依据。方法：选择1例健康青年男性志愿者，在其双侧TMJ区和颏部共放置12个人造球形标记，经CT和MRI扫描，获取含有所有球形标记的TMJ医学图像，分别采用CT和MRI两套数据建立TMJ软硬组织的三维几何模型。基于人造球形标记在三维空间上配准，对TMJ软硬组织进行三维重建。结果建立了具有良好几何相似性的TMJ三维几何模型，包括关节盘、关节窝、下颌骨和下牙列。TMJ三维几何模型的建立方法简便快捷，模型逼真，解剖结构清楚，能较真实地反映TMJ各结构的空间位置关系。结论利用CT和MRI医学图像融合技术，基于人造球形标记的配准过程进行TMJ三维重建，所建立的模型具有良好的几何相似性。在三维水平上进行图像的融合，具有定位精确，配准过程简单等特点，能真实、合理地对TMJ软硬组织进行三维重建。

目的：通过研究雌激素对慢性间歇性低氧（chronic intermittent hypoxia CIH）大鼠颏舌肌线粒体细胞色素c氧化酶（cytochrome C oxidase, COX）活性及其亚基（C0x I、coxⅣ）表达的影响，探讨阻塞性睡眠呼吸暂停低通气综合征（OSAHS）发病中雌激素所起的作用。方法：3个月龄健康雄性SD大鼠48只，分为正常对照组（NC组）、慢性间歇性低氧组（CIH组）及慢性间歇性低氧雌激素干预组（E+CIH组）。后两组建立CIH模型，同时E十CIH组给予苯甲酸雌二醇0.2 mg/kg，NC组、CIH组给予无菌橄榄油O.2 ml/次，2次/周，肌肉注射。密度梯度离心法分离大鼠颏舌肌线粒体，极谱法测量cox活性；western blottiIlg分析C0X I和coxⅣ蛋白表达；实时聚合酶链反应（real time p01ymerase chain action）法检测COX I和coxⅣ的基因表达。结果：CIH组大鼠颏舌肌线粒体C0X活性为（O.143±O.029）jkat/mg，与Nc组[（0.273±0.058）ukat/mg]相比显著降低（P<0.01），E+CIH组COX活性[（O.203±O.073）ukat/mg]较CIH组有所回升（P<0.05），但仍显著低于NC组（P<0.05）。CIH组与E+CIH组COX I蛋白表达分别为（10.789±8.144）和（25.593±11.108），与NC组（47.325±7.502）相比均显著降低（P<0.01），且E+CIH组COX I蛋白表达显著高于CIH组（P<O.05）。3组COXⅣ蛋白表达的差异无统计学意义（P>0.05）；3组COX I、COXⅣ mRNA表达量的差异无统计学意义（P>O.05）。结论CIH可抑制大鼠颏舌肌线粒体COX蛋白表达及活性，而雌激素干预可部分恢复C0X蛋白表达及活性。

目的：探讨雌激素对慢性间歇性低氧大鼠颏舌肌等长收缩功能及肌细胞超微结构的影响。方法：健康雄性SD大鼠40只，随机分为正常对照组（NC）、慢性间歇性低氧组（CIH）、低、中、高剂量雌激素干预组（LE、ME、HE）。后4组建立CIH大鼠模型（8 h/d，5周），同时LE、ME、HE组分别予苯甲酸雌二醇0.l、O.2、O.3 mg/kg（2次/周）肌肉注射，NC、CIH组予无菌橄榄油O.2 mL/次肌肉注射。第5周末电刺激法测定各组大鼠颏舌肌等长收缩功能的变化，透射电镜观察肌细胞超微结构的改变。结果：各组大鼠颏舌肌单刺激收缩、强直收缩最大张力无明显变化；诱导疲劳试验中各时间点颏舌肌抗疲劳性：CIH组显著低于NC组（P<O.01），ME、HE组明显高于CIH组（p<O.05，P<O.01）；颏舌肌细胞超微结构：CIH组肌原纤维结构紊乱，部分肌丝溶解、消失，线粒体水肿，嵴断裂，空泡变；ME、HE组肌原纤维病变减轻，部分线粒体水肿，嵴减少。结论：慢性间歇性低氧可破坏大鼠颏舌肌细胞超微结构，降低抗疲劳能力；中、高剂量雌激素可不同程度逆转低氧对肌细胞超微结构及抗疲劳能力的损伤，保护低氧大鼠颏舌肌的抗疲劳能力。

目的：比较两种下颌前伸定位方法确定的口腔矫治器治疗阻塞性睡眠呼吸暂停低通气综合征（0S-AHS）患者的主、客观疗效，并对两种方法作出综合评价。方法：采用交叉试验设计对10例男性OSAHS患者分别使用可调式口腔矫治器与计算机辅助下颌前伸定位系统（CAMRs）进行下颌前伸测定，然后患者先后分别戴用可调式口腔矫治器与根据CAMRS测定结果制作的“测定式”口腔矫治器治疗3个月；采用单因素方差分析比较两者的最适下颌前伸量以及主、客观疗效。结果：可调式口腔矫治器测定的最适下颌前伸量大于CAMRs的测定值，但差异无统计学显著性意义（P>O.05）；两种口腔矫治器治疗0SAHS的主、客观疗效显著，“测定式”口腔矫治器在缩短最长呼吸暂停时间、提高睡眠效率及睡眠质量方面优于可调式口腔矫治器（P<0.05）。结论：两种下颌前伸定位方法各有优缺点。根据其测定结果制作的口腔矫治器对0SAHS患者均有良好的疗效。