低强度脉冲超声波对Beagle犬Ⅱ度根分叉病变的辅助效应***◆

背景：低强度脉冲超声波主要用于促进骨折愈合及提高新生骨组织密度,尚未见其对Ⅱ度根分叉病变组织学修复效应的报道。 目的：观察低强度脉冲超声波对Ⅱ度根分叉病变的组织学修复效应。 方法：5只Beagle犬各取2颗下颌第4前磨牙颊侧作为实验区,建立Ⅱ度根分叉病变模型,分别分为超声组和对照组并在颊侧缺损龈方根面制备切迹作为参照点,高糖饲养8周。超声组行根面平整术,术后1周行低强度脉冲超声波(90 mW/cm2,1.5 MHz,200 μs,1 kHz)处理20 min/d,对照组行根面平整术和假处理。6周后取实验区域组织制备脱钙切片,苏木精-伊红染色、Masson染色行根分叉区域组织测量分析。 结果与结论：超声组根分叉区新生牙槽骨沿根面生长,根分叉区可见牙龈上皮;对照组根分叉区以结缔组织生长为主,可见大量牙龈上皮和少量新生骨组织。超声组新生牙槽骨胶原呈“红-蓝”相间,以红染为主;对照组呈现蓝染,即超声组的新生牙槽骨胶原较对照组成熟。超声组牙槽骨、牙骨质、牙周膜新生量均大于对照组(P < 0.05)。提示90 mW/cm2低强度脉冲超声波可促进根分叉病变新生牙槽骨胶原成熟和改建。     

小型猪颈动脉粥样硬化性狭窄模型的初步建立

目的探索建立适合于神经介入研究的动脉粥样硬化性颈动脉狭窄动物模型的方法。方法以12头广西巴马小型猪为实验对象,以高脂饲养和动脉球囊损伤为模型建立的主要手段。应用体外超声、数字减影血管造影(DSA)和血管内超声(IVUS)评价颈动脉狭窄的形成情况,并对颈动脉的病理改变特点进行评价,最后分析总结出创建动脉粥样硬化性颈动脉狭窄动物模型的理想方案。结果16周时的DSA发现：高脂饲养和动脉球囊损伤组平均狭窄率达33．32%±12．84%；病理检查证实有明显的粥样硬化斑块形成。结论高脂饲养加动脉球囊损伤,16周可以初步建立广西巴马小型猪颈动脉粥样硬化性狭窄模型。     

小型猪脑缺血模型的建立及影像学评价

目的:建立小型猪脑缺血模型,并通过数字减影血管造影(DSA)、磁共振弥散加权成像(DWI)、磁共振灌注加权成像(PWI)进行评价。方法:6月龄小型猪14头采用双侧咽升动脉气囊阻断法制作脑缺血模型,于阻断前、阻断期及再灌注0.5h、2h分别给予DSA、DWI、PWI和MRI评价。结果:阻断期DSA可见双侧咽升动脉及其分支血管血流阻断,再灌后0.5h及2h双侧咽升动脉及其分支血管血供恢复;阻断前DWI、PWI均未见异常,阻断期及再灌注各时间点DWI、PWI发现异常高信号,表观弥散系数(ADC)值和局部脑血流(rCBF)下降,达峰时间(rTTP)延迟;T1WI和T2WI在阻断前、阻断期和再灌后各时间点均未发现异常信号。结论:通过磁共振影像学评价证明双侧咽升动脉气囊阻断法制作小型猪脑缺血模型是稳定的、可重复的,此方法可造成程度较为一致的小型猪缺血性脑损伤。     

滇南小耳猪人工瓣膜置换模型的建立*

背景：猪和人的心脏解剖结构特点相似,是研究心血管疾病的理想模型。 目的：建立滇南小耳猪二尖瓣置换模型,应用心脏超声评估模型建立的可行性。 方法：成年猪10头,均于体外循环下经左心耳径路行二尖瓣置换,人工瓣膜为St.Jude双叶机械瓣,采用3种置换方式,并以心脏超声分析瓣膜置换后2周小耳猪心脏结构和功能的变化。 结果与结论：除1头因麻醉诱导期出现室颤死亡外其余均存活。心脏超声显示3种方式置换瓣膜后2周,猪心脏结构和功能与置换前无显著差异。人工机械瓣膜在猪体内的血流动力学和组织相容性均良好,二尖瓣置换前后猪的心脏结构及功能稳定。     

幼猪脑出血模型的建立与评价

目的探索建立稳定、可靠、重复性好的幼猪脑内血肿模型。方法利用未肝素化自体血制作幼猪脑基底节区血肿。实验分缓慢注射组(n=12)和快速注射组(n=12),通过取脑切片,采用计算机图像分析系统计算各组脑内血肿体积,同时观察血肿周围组织病理变化,从而评价两种注射法的差异。结果缓慢注射法(二次注入法)可形成较稳定、形态规则的血肿,无蛛网膜下腔和脑室积血表现,脑内血肿体积(1.84±0.28)cm3。快速注射组血肿易破入蛛网膜下腔和脑室内,脑内血肿体积(1.13±0.48)cm3,两种注射法所形成的脑内血肿大小比较差异有统计学意义(P<0.05)。而两组血肿周围脑组织病理形态学表现均为血肿周围白质疏松水肿与炎性细胞侵润。结论采用缓慢注射法(二次注入法),将未肝素化自体血缓慢匀速注入幼猪脑基底节区,可形成稳定、可靠、重复性好的脑内血肿模型。     

吉兰-巴雷综合征空肠弯曲菌感染诱导巴马小型猪致周围神经病动物模型的建立

目的使用致吉兰-巴雷综合征的空肠弯曲菌活菌诱导的巴马小型猪建立周围神经病动物模型。方法使用吉兰-巴雷综合征病人粪便中分离的空肠弯曲菌,微需氧培养后口服攻毒30只巴马小型猪,建立周围神经病动物模型。结果实验组在攻毒后14～16天出现临床症状,两周内解剖。临床症状周围神经病重症的占40.9%(9/22),出现周围神经病症状的占81.8%(18/22)。病理学检查锇酸染色可见卵圆体结构,镀银坚固蓝染色见轴索断裂,未见脱髓鞘。结论本实验通过致吉兰-巴雷综合征的空肠弯曲菌活菌构建了巴马小型猪周围神经病动物模型,模拟了自然条件下侵染致病的过程,为研究周围神经病的发病机理提供了大型动物模型。     

兔胫骨骨折模型的不同固定方法*

背景：利用一种有效的固定方法维持骨折的稳定性是胫骨骨折动物模型成功制备的基础。 目的：观察4种不同的固定方法对兔胫骨骨折模型的固定效果。 方法：将日本大耳白兔截断胫骨骨干后随机分为4组,以4种方法分别固定：①直腿双托组：直腿双托石膏外固定。②塑形双托组：屈膝屈踝双托石膏外固定。③塑形管型组：屈膝屈踝管型石膏外固定。④内外固定组：克氏针内固定+屈膝屈踝双托石膏外固定。 结果与结论：相比其他3组,直腿双托组的外固定石膏脱落时间更早,损伤肢感染率更高(P < 0.05)。在骨折后第4周,内外固定组发生骨折断端移位的实验兔数量最少(P < 0.05)。证实只采用内固定+屈膝屈踝双托石膏外固定才能维持实验兔胫骨骨折的稳定性。     

建立桡骨缺损模型：骨缺损标准尺寸的确立*

背景：不同研究所采用的桡骨骨缺损模型长度均不同,目前尚没有统一的桡骨缺损标准尺寸。 目的：对兔桡骨缺损模型施行标准化研究再探讨,以期获得相对更可靠的兔桡骨缺损标准尺寸。 方法：选用健康6月龄新西兰大白兔40只,双侧桡骨共80侧,在麻醉下行兔桡骨手术造成桡骨完全骨膜缺损,将桡骨随机分为5组,分别为缺损1.0,1.2,1.4,1.7和2.0 cm组,每组16侧。分别于术后12周行X射线、大体解剖、CT三维重建和组织切片等检查,观察各组骨缺损愈合情况。 结果与结论：建模后12周可见缺损1.0 cm组至缺损2.0 cm组愈合率逐步下降,1.4 cm骨缺损组愈合率低于1.0及1.2 cm组(P < 0.05)。1.4,1.7,2.0 cm骨缺损组X射线评分及CT评分值均低于1.0及1.2 cm骨缺损组(P < 0.05),说明骨缺损尺寸在1.2 cm以下时,桡骨自行愈合率相对较高。结果提示实验成功建立了兔桡骨骨缺损模型,桡骨中段缺损(包括骨膜)尺寸≥1.4 cm更加可靠。     

骨折并侧方液压脑损伤模型的建立

目的：拟建立一种伤情稳定、重复性好的骨折与脑损伤复合模型，为临床脑损伤骨折患者骨折愈合加速的机制研究提供动物模型。 方法：实验于2007-04/08在广西医科大学动物实验中心完成。雄性SD大鼠72只，按体质量经SPSS 15.0随机分为空白对照组（n=6），单纯骨折组(n=30)，脑损伤骨折组(n=36)。用改良的脑损伤液压装置，采用侧方液压法建立SD大鼠脑损伤模型。用摆锯从胫骨外侧锯断胫骨中段，然后行克氏针髓腔逆行固定，制备胫骨骨折模型。 结果：72只大鼠均进入结果分析。①伤后3 h，脑损伤骨折组大鼠顶叶、额叶、枕叶蛛网膜下腔出血，大脑皮质及白质深部的基底节、海马、胼胝体、丘脑挫伤出血，苏木精-伊红染色显示，挫伤周围神经元变性、坏死。伤后1 d 挫伤灶周围神经元数量明显减少，可见血管周围出血及均质透明栓形成。②术后4周X射线平片显示脑损伤骨折组骨痂大于单纯骨折组且骨痂致密，骨痂直径及骨痂应力大于单纯骨折组（P < 0.05）。 结论：股骨离断及侧方液压制作的SD大鼠骨折脑损伤动物模型伤情稳定、重复性好，能满足脑损伤骨折实验研究的需要。     

兔腰椎间盘退行性病变模型的建立及影像学改变☆

背景：建立最佳的椎间盘退行性病变动物模型对了解椎间盘退行性病变的发生机制、预防与治疗均具有重要意义。 目的：以针刺损伤制备兔椎间盘退行性病变模型，通过X射线及MRI分析针刺损伤对椎间盘高度及退行性病变的影响。 设计：随机对照观察。 单位：解放军第二军医大学长海医院骨科。 材料：实验于2005-06/2006-04在解放军第二军医大学长海医院动物中心完成，选用6只健康新西兰大白兔，雌雄不拘，平均6月龄，体质量平均为2.5 kg，均来自解放军第二军医大学长海医院动物中心，许可证号码为SCXK (hu) 2002-0006。实验过程中对动物的处置符合动物伦理学标准。 方法：①采用腹膜后入路对实验兔腰椎进行手术，以L3~4椎间盘为正常对照, 不做处置；L4~5椎间盘作为假手术，只进行暴露；L5~6椎间盘暴露后用24 G针头从椎间盘的前外侧针刺3次。②分别于术前及术后4周采用Simens公司CR机拍摄腰椎正侧位X射线片，测量L3~4，L4~5及L5~6椎间隙高度，计算与术前椎间隙高度比值；采用Simens Avanto 1.5 T 医用超导型磁共振扫描仪检测各节段腰椎间盘T2加权信号，根据信号强度记分，4分为正常椎间盘，髓核内信号均匀、明亮；3分为轻微退行性病变椎间盘，T2加权信号部分降低；2分为中度椎间盘退行性病变，T2加权信号明显降低；1分为重度椎间盘退行性病变，其T2加权信号明显降低，而且伴有椎间隙狭窄。 主要观察指标：①腰椎X射线侧位片椎间盘高度变化。②椎间盘退行性病变程度。 结果：纳入实验兔6只，均进入结果分析，无脱落。①椎间盘高度变化：L3~4及L4~5术后与术前椎间盘高度比分别为0.982 5±0.017 08，0.972 5±0.017 08，均高于L5~6椎间盘高度比（0.550 0±0.025 82），差异有统计学意义（P < 0.01）。②腰椎MRI的T2加权像上观察椎间盘退行性病变程度：L3~4及L4~5椎间盘T2加权像信号得分分别为（4.00±0.0），（3.75±0.5）分，均高于L5~6椎间盘，差异有统计学意义（P < 0.01）。 结论：针刺损伤实验兔椎间盘4周后可造成椎间盘高度降低，并使椎间盘出现明显退行性病变。     

The critical component to establish in vitro BBB model: Pericyte

The blood–brain barrier (BBB), a highly regulated membranous barrier of brain capillaries, consists of an intricate network of tight junctions (TJs) that segregate the central nervous system (CNS) from systemic blood circulation and maintain a delicate homeostasis of the CNS environment. While endothelial cells (ECs) of brain capillaries are clearly the principal cellular element of BBB, the formation and regulation of intact BBB structure appear to require the interactions of endothelial cells with other cellular components. Astrocytes, one of the major non-neural cells in the brain, associate closely and interact with capillary endothelial cells during the angiogenesis and BBB development. Current in vitro cellular models for the study of BBB functions often incorporate astrocytes with endothelial cells. However, another foremost cell type, CNS pericyte, which intimately embraces brain capillary endothelium, attracts relatively little attention for its role in developing the in vitro BBB system. This review will analyze the critical functions of pericytes in angiogenesis in various systems and discuss the relevance of these functions in mediating the development, maintenance, and regulation of BBB. The author will also discuss the functional role of actin in both ECs and pericytes, and further elaborate the molecular mechanisms of BBB permeability regulation that involves the transduction pathway-mediated actin remodeling process. Finally, the rationale of incorporating pericytes for establishing a better in vitro BBB model will be emphasized.     

兔膝关节软骨缺损动物模型的建立

背景：以往制备骨关节模型的方法成模时间较长。 目的：建立一个理想的兔膝关节软骨缺损动物模型。 设计、时间及地点：随机分组设计,对照动物实验,于2007-03/2008-10在广州市红十字会医院创伤外科研究所完成。 材料：用新西兰大白兔16只,雌雄不限,体质量3.2~4.0 kg。 方法：以6 g/L戊巴比妥钠行耳缘静脉注射麻醉下,通过在实验兔后腿关节的股骨髁关节面部位用电动骨钻,在控制其直径4.5 mm,深度为3 mm,造成其关节软骨的缺损,制模后2,6,12,18周取出其股骨髁。 主要观察指标：用大体观察、组织学染色共聚焦显微镜观察缺损部位软骨修复情况。 结果：实验兔后腿关节的股骨髁关节面的关节软骨缺损后,在制模后2,6周缺损部位凹陷明显,只有少许肉芽组织和纤维组织生长填充,未见软骨细胞爬行生长,12,18周见缺损部位以纤维组织增生为主,底部及边缘可见骨组织和软骨增生,但是镜下形态仍与正常软骨组织区别较大,表面仍未见软骨细胞爬行生长。 结论：实验建立的兔膝关节软骨缺损模型成模时间短,且缺损部位不能通过自我修复达到自愈。     

改良四血管阻塞法建立大鼠全脑缺血模型

目的对四血管阻塞法(4-VO)建立大鼠全脑缺血模型进行改良,以提高模型的可靠性.方法以微型磨钻,扩大第一颈椎上之翼孔,充分暴露其中穿行的椎动脉,显微镜直视下电凝阻断;夹闭双侧颈总动脉以出现静息脑电波为判定大鼠已达全脑缺血的标准对4-VO法建立大鼠全脑缺血模型进行改良.全脑缺血15 min后行再灌注,7 d后以海马CA1区神经元出现大部分死亡作为判定模型成功的标准,对两种建模方法进行评定.结果 4-VO法制作大鼠全脑缺血再灌注模型,大鼠存活7 d的存活率为90%(27/30),改良4-VO法制作大鼠全脑缺血再灌注模型,大鼠存活率为86.7%(26/30),二者无明显差异(P>0.05);4-VO法制作大鼠全脑缺血再灌注模型其成功率仅为70%(21/30),改良4-VO法制作大鼠全脑缺血再灌注模型,成功率为86.7%(26/30),明显高于4-VO法.结论改良4-VO法可明显提高模型制作的可靠性和成功率     

经颈总动脉和经颈外动脉制作大鼠MCAO模型的比较

大鼠大脑中动脉闭塞模型（MCAO）是局灶性脑缺血再灌注的标准动物模型,该模型为研究人类局灶性脑缺血的疾病特点、发病机制及防治策略提供了可靠平台。本文综述了MCAO模型成功的评价标准,并从动物、线栓、原理、制备方法及改进等方面比较了经颈总动脉进线法和经颈外动脉进线法分别制备大鼠MCAO模型的特点,并对影响大鼠MCAO模型制备成功率的主要因素进行了综述和优化配置。     

立体定向下恒河猴偏侧部分损伤性帕金森病模型的制作

目的　制作一种能保留内侧前脑束 (MFB)内的多巴胺 (DA)神经纤维的偏侧部分损伤性帕金森病(PD)猴模型。方法　以 6 羟多巴 (6 OHDA)溶液对 12只恒河猴右侧黑质致密部行多靶点毁损。术后进行行为学观察、MR、PET、SPECT检查及酪氨酸羟化酶 (TH)的免疫组织化学染色。结果　猴术后符合帕金森病表现。MR示靶点准确位于黑质 ,PET示毁损侧黑质纹状体区代谢减低。TH染色示黑质致密部DA能神经元毁损达 80 %以上 ,而中脑腹侧被盖区和MFB区的DA能神经纤维保留较好。结论　用立体定向注射 6 OHDA毁损一侧黑质致密部的方法可制作出偏侧部分损伤性帕金森病恒河猴模型     

Standardization of lupus anticoagulant. Feasibility study of a calibration model to minimize between-method variability

Background

Results for lupus anticoagulant (LA) are currently expressed as ratio of patient-to-normal clotting times (LA-ratio). Yet, numerical results do vary according to the method used for testing, thus making difficult the between-method comparison of results. We hypothesized that the standardization model currently used for the INR for patients on oral-anticoagulants (OAT) would be of value also for LA standardization.

Patients and Methods

To test this hypothesis we determined a sensitivity index valid for LA (called LASI) for six LA-detection methods against a common-standard using two sets of calibration-plasmas: (i)normal-plasmas spiked with IgG derived from patients strongly-positive for LA or (ii)plasmas from LA-positive patients. The LASI was then used to convert the LA-ratio into the standardized-LA-ratio (SLA-ratio) according to the equation: SLA-ratio = (LA-ratio)^LASI.

Results

We demonstrate that (i)the model is feasible because calibration plots of log-transformed clotting times obtained for the LA-detection methods-vs.-the common-standard gave acceptable LASI values; (ii)the model is effective because between-method variability expressed as coefficient of variation, which was 42.8% with results expressed as LA-ratio, decreased to 7.8% with results expressed as SLA-ratio; (iii)the LASI value calculated with the LA-positive plasmas is more effective in minimizing between-method variability than the LASI value calculated with IgG-spiked plasmas.

Conclusions

A model of LA calibration similar to the INR for patients on OAT is feasible by using plasmas from LA-positive patients instead of patients on OAT. Potential application of the model are:(i)to compare the relative responsiveness of different LA-detection methods,(ii)to minimize differences between their results and (iii)to quantify LA potency.     

Response restriction as a method to establish diurnal bladder control

In this study, a new procedure to establish diurnal bladder control was evaluated. Eight children with severe and moderate levels of mental retardation participated. The procedure was based on the behavior theoretical concept of response restriction. Data were collected within a nonconcurrent multiple baseline design. Seven participants attained a level of bladder control in that they remained without urinary accidents between regular toileting times. Follow-up measures revealed maintenance of these results. The results are discussed in terms of the advantages of this procedure as compared with existing procedures in this area, especially with respect to the omission of the restitutional overcorrection procedure.     

Progressive myopathy with a combined respiratory chain defect including Complex II

Biochemical defects in the respiratory chain are mostly associated with deficiencies in Complexes I, III and IV, caused by nuclear or mitochondrial DNA mutations. Combined defects including Complex II have been reported very rarely and have muscular symptoms as the main manifestation, including muscle weakness, exercise intolerance and myoglobinuria. We report a patient with a fatal progressive myopathy and muscle biopsy showing diffuse reduction in succinate dehydrogenase activity, ragged red fibers and intense lipid accumulation. Cytochrome c oxidase (COX) histochemistry demonstrated 30% of fibers with increased subsarcolemmal staining while 27% were COX negative. Western blotting analysis showed reduction in the expression of the 39 kDa subunit of Complex I, subunit II of Complex IV and the 70 kDa subunit of Complex II. Our findings suggest that the patient had a complex pattern of mitochondrial dysfunction affecting multiple respiratory chain complexes (I, II and IV) and fatty acid metabolism. This report adds a new histological pattern associated to combined deficiencies of respiratory chain with involvement of Complex II and shows that this disease may be fatal with a rapid progression.     

Multiple sclerosis: relevance of class I and class II MHC-expressing cells to lesion development

Expression of Class I (HLA-ABC) and Class II (HLA-Dr; Ia) major histocompatibility (MHC) antigens on endothelial cells and astrocytes was investigated in multiple sclerosis (MS) lesions of variable disease activity and in normal central nervous system (CNS) using immunocytochemical techniques. Findings were correlated to lesion pathology and to the presence and distribution of T cells, T cell subsets, and interleukin-2 (IL-2) receptor-bearing cells. HLA-ABC was present on virtually all endothelial cells in normal and pathologic tissue samples. Ia was absent from controls and was detectable on about 10% of CNS endothelial cells in MS. In normal CNS, astrocytes were Ia-negative and rarely expressed HLA-ABC. In MS, Class I and II MHC-positive astrocytes were found, and both displayed a high frequency in active lesions. Class I-reactive glia were primarily associated with T cell infiltrates and were less common in older lesions in which macrophages predominated. In contrast, Class II-positive astrocytes were found in all active MS lesions independent of the composition of inflammatory cells. Expression of HLA-ABC and Ia molecules on astrocytes in MS lesions could indicate their involvement in local presentation of antigen to cytotoxic (T8+) and helper/inducer (T4+) T cells, respectively. The observed distinct distribution patterns of HLA-ABC and Ia-positive astrocytes might suggest that cytotoxic T8+ cells are operative early during lesion development in MS. This could be followed by a more extensive Class II MHC-restricted helper T cell-mediated immune response which leads to selective destruction of myelin via activated macrophages.