生物黏附材料壳聚糖的黏附性能

目的:考察壳聚糖与黏蛋白的相互作用,评价壳聚糖黏附性能的影响因素。方法:于2006-07/12在中国科学院大连化学物理研究所生物医用材料工程实验室完成。将壳聚糖溶液与黏蛋白溶液混合,用紫外分光光度计测定溶液混合前后紫外吸收值的变化,表征壳聚糖的黏附性能。①调节反应溶液的pH值(1.0,3.0,5.0),考察环境pH对壳聚糖黏附性能的影响。②改变反应温度(4,25,37℃),考察环境温度对壳聚糖黏附性能的影响。③选择不同相对分子质量(48000,124000,230000)的壳聚糖,考察壳聚糖相对分子质量对其黏附性能的影响。④选择不同脱乙酰度(56%,67%,97%)的壳聚糖,考察壳聚糖脱乙酰度对其黏附性能的影响。⑤使用不同种类(I-S型及Ⅲ型)黏蛋白,考察黏蛋白中唾液酸含量对壳聚糖黏附性能的影响。结果:①环境介质pH由1.2升至5.0时,壳聚糖黏附性能随之显著升高。②壳聚糖黏附性能随着温度的升高而显著增强。③壳聚糖相对分子质量对于壳聚糖黏附无显著影响。④壳聚糖脱乙酰度增加,其黏附性能显著增强。⑤I-S型黏蛋白与壳聚糖的作用较之Ⅲ型黏蛋白与壳聚糖的相互作用明显增强。结论:壳聚糖的黏附受环境pH、温度、壳聚糖及黏蛋白两种分子电荷密度的显著影响;在酸性环境下增大环境pH值、升高环境温度、增加壳聚糖的脱乙酰度和增加黏蛋白中唾液酸的含量,均有利于壳聚糖的黏附。     

骨髓间充质干细胞体外转化为神经细胞的环境特征

目的:探讨大鼠骨髓间充质干细胞的分离培养条件,体外定向诱导传代骨髓间充质干细胞向神经干细胞转化并进一步向神经细胞分化的环境,并对分化的神经元进行鉴定。方法:实验于2005-08/2007-03在南京大学医学院附属鼓楼医院科研部完成。①选用健康SD大鼠,分离纯化并培养大鼠骨髓间充质干细胞。②应用流式细胞仪检测细胞表面抗原的表达,通过免疫表型鉴定骨髓间充质干细胞.③贴壁培养诱导骨髓间充质干细胞向神经细胞分化,分为对照组和诱导剂组,对照组中不加诱导剂,诱导剂组分两步诱导:首先加入含终浓度均为10μg/L的表皮生长因子、碱性成纤维细胞生长因子诱导分化剂,连续培养12 d:然后应用20μg/L的脑源性神经营养因子和1μmol/L的全反式维甲酸继续诱导6 d,分别收集诱导1 d,6 d,12 d,18 d的细胞进行细胞免疫荧光鉴定。结果:①传代第3代骨髓间充质干细胞为梭形成纤维样细胞,均一稳定的表达与间充质干细胞相关的表面抗原标记物CD29,CD44,CD90、阳性率分别为98.88%,96.90%.95.86%,但极少表达造血细胞标志CD34。②经碱性成纤维细胞生长因子和表皮生长因子诱导12 d后诱导剂组巢蛋白阳性表达率为(89.24±2.12)%,而对照组细胞未表达巢蛋白。③经脑源性伸经营养因子和全反式维甲酸联合诱导6 d后,诱导剂组均可见微管相关蛋白2阳性细胞,大部分细胞转变为神经元样细胞形态;对照组微管相关蛋白2阴性.细胞形态仍为梭形成纤维样细胞。结论:实验采用并改良了全骨髓贴壁法,操作简单快速.细胞活性好,是一种较为理想的分离和纯化骨髓间充质干细胞的方法.骨髓间充质干细胞可分化成神经干细胞,进一步诱导分化为神经细胞。     

骨髓间充质干细胞移植入脑缺血大鼠侧脑室后的迁移及分化:免疫荧光标记

目的:骨髓间充质干细胞可以分化成神经细胞替代受损组织,并可分泌生长因子和营养因子来促进其体内细胞的存活和分化。实验将体外扩增和Hoechst33342标记的骨髓间充质干细胞移植入缺血性大鼠侧脑室内,观察干细胞在大鼠脑内的生存、迁移、分化情况及对神经功能恢复的影响。方法:实验于2004-12/2007-06在南京大学医学院附属鼓楼医院科研部完成。①取体质量120～160g的SD大鼠用于制备移植细胞;另取80只体质量250～300g的SD大鼠用于制作大脑中动脉闭塞模型。实验方法符合动物伦理学要求。②应用直接贴壁法分离纯化及扩增大鼠骨髓间充质干细胞,荧光染料Hoechst33342标记。③将造模成功的75只大脑中动脉闭塞大鼠按随机数字表法分为3组:模型对照组15只;磷酸缓冲液组30只;骨髓间充质干细胞移植组30只,将骨髓间充质干细胞立体定向移植到大鼠缺血侧脑室中。④术后1,3,6,12,24d测定大鼠神经功能损害评分,荧光显微镜下观察Hoechst33342标记的骨髓间充质干细胞在脑内的生存和迁移情况,采用免疫荧光法检测胶质原纤维酸性蛋白和微管相关蛋白2的表达。结果:①细胞移植后6d,12d骨髓间充质干细胞移植组大鼠的神经功能评分均显著低于磷酸缓冲液组(P<0.05)。②移植的骨髓间充质干细胞可在大鼠脑组织中存活,并向缺血区域迁移。③移植第24天Hoechst33342/微管相关蛋白2、Hoechst33342/胶质原纤维酸性蛋白双阳性细胞占Hoechst33342阳性细胞的百分率为(10.45±1.35)%,(8.73±1.38)%。结论:骨髓间充质干细胞可以在动脉闭塞局灶性脑缺血模型大鼠脑中存活,并向缺血区域附近迁移,在一定条件下可分化为神经元和星形胶质细胞,同时能促进局灶性脑缺血大鼠的神经功能恢复。     

Nasolabial aesthetics

Orthognathic surgery, as it relates to the maxilla, attempts to correct underlying skeletal deformities as well as improve function. In addition, it has the potential to significantly alter the central aesthetic unit of the face, the nasolabial region. A key to achieving a good functional as well as aesthetic result involves both comprehensive surgical planning and an understanding of the effects that orthognathic surgery of the maxilla will have on the soft tissues within the nasolabial region. The LeFort I osteotomy is one of the most commonly performed techniques to correct maxillary dentofacial deformities. The effects of nasal and labial changes after a LeFort I osteotomy, including widening of the alar bases of the nose, changes in the nasal tip, and flattening and thinning of the upper lip, have been previously reported by other authors. This article will discuss the nasolabial region and discuss steps involved in performing a comprehensive aesthetic evaluation, as well how the LeFort I osteotomy may produce specific changes related to the external nasal morphology. In addition, emphasis will be given to the lips, and the effects of reduction and augmentation procedures will be discussed as they relate to the nasolabial region.     

仰卧和俯卧位心脏对煤尘肺患者肺组织体积与功能的影响

目的:观察仰卧位和俯卧位心脏对煤尘肺患者肺组织体积和肺功能的影响,为临床应用俯卧位治疗成人呼吸窘迫综合征等肺部疾病提供依据。方法:2006-08/2007-01河南鹤煤集团公司总医院放射科对10例煤尘肺患者行仰、俯卧位高分辨螺旋CT扫描,分别测量位于心脏下方肺组织的体积,测量仰、俯卧位状态下肺功能,用配对t检验进行统计学分析。结果:10例患者均进入结果分析。①CT扫描心脏压迫下的肺组织体积:俯卧位时均小于仰卧位[左肺:(7.74±9.55),(242.60±72.11)mm3;右肺:(12.21±11.41),(156.49±76.54)mm3,P均<0.01]。②肺功能测量结果:仰卧位时,患者的用力肺活量、第1秒用力呼气容积、第1秒用力呼气容积预计值百分率、最大呼气量,分别为(2.14±0.58)L、(1.62±0.79)L、(89.80±29.26)、(3.42±1.98)L/s;俯卧位时,患者的用力肺活量、第1秒用力呼气容积、第1秒用力呼气容积预计值百分率、最大呼气量,分别为(2.36±20.79)L、(1.80±0.77)L、(100.10±22.46)、(4.30±2.37)L/s。俯卧位时肺功能明显优于仰卧位(P<0.05)。结论:俯卧位时位于心脏下方的肺组织明显减少,可显著改善人体的肺换气功能。     

Surgical management of a giant plexiform neurofibroma of the lower extremity

The authors review their experience with the management of a giant 49-kg (108 lb) neurofibroma of the lower extremity in a 37-year-old male with NF1. The patient presented with right thigh pain, paresthesias, increasing edema, and accelerated growth of the mass. The patient was taken to the operating room, where approximately 39 kg (86 lb) of tumor and 10 L (22 lb) of interstitial fluid was removed. The postoperative course was complicated by cellulitis, delayed wound closure, and recurrent lymphedema. Complications were managed with antibiotics, ultrasound-guided drainage, surgical revision of closure, compressive dressings, passive drainage, and vacuum-assisted wound closure. Giant neurofibromas similar to this tumor require complex intraoperative and postoperative management strategies. Surgical closure is best managed with local flaps, and postoperative lymphedema is best managed with passive drainage and compressive dressings.     

虎杖乙酸乙酯萃取部分抗人疱疹病毒研究

目的：ＨＳＶ可引起多种疾病,时洛韦（ＡＣＶ）治疗ＨＳＶ感染效果虽好,但易出现耐药毒株;新药Ｃｉｄｏｆｏｖｉｒ对ＡＣＶ耐药毒株效果好,毒性也大。ＨＳＶ疫苗临床实验效果也不好。为了解决这些问题,必须继续开发新药。虎杖是一种抗病毒范围广的中药毒株为了了解虎杖的生能并开发利用,我们对虎杖乙酸乙酯萃取部分的抗ＨＳＶ药效进行了研究。方法：我们以ＡＣＶ为阳性对照,利用病毒细胞病变抑制及空斑减数实验了药效,并且用     

Serum hepatitis B surface antigen correlates with fibrosis and necroinflammation: A multicentre perspective in China

The kinetics of serum hepatitis B surface antigen (HBsAg) during the natural history of hepatitis B virus (HBV) infection has been studied, but the factors affecting them remain unclear. We aimed to investigate the factors affecting HBsAg titres, using data from multicentre, large‐sized clinical trials in China. The baseline data of 1795 patients in 3 multicentre trials were studied, and the patients were classified into 3 groups: hepatitis B early antigen (HBeAg)‐positive chronic HBV infection (n = 588), HBeAg‐positive chronic hepatitis B (n = 596), and HBeAg‐negative chronic hepatitis B (n = 611). HBsAg titres in the different phases were compared, and multiple linear progression analyses were performed to investigate the implicated factors. HBsAg titres varied significantly in different phases (P = .000), with the highest (4.60 log10 IU/mL [10%‐90% confidence interval: 3.52 log10 IU/mL‐4.99 log10 IU/mL]) in patients with HBeAg‐positive chronic HBV infection. In all phases, age and HBV DNA were correlated with serum HBsAg level. In HBeAg‐positive chronic hepatitis B patients, a negative correlation between HBsAg titres and fibrosis stage was observed. Alanine amonitransferase or necroinflammatory activity was also correlated with HBsAg titres in HBeAg‐negative chronic hepatitis B patients. In conclusion, decreased HBsAg titres may be associated with advancing fibrosis in HBeAg‐positive chronic hepatitis B patients or increased necroinflammation in those with HBeAg‐negative chronic hepatitis B. Our findings may help clinicians better understand the kinetics of HBsAg and provide useful insights into the management of this disease.