缺氧诱导因子转染内皮祖细胞治疗大鼠缺血后肢

目的 使用缺氧诱导因子-1α(HIF-1α)转染内皮祖细胞(EPC)治疗大鼠后肢缺血,观察EPC、HIF-1α转染EPC对大鼠缺血后肢血管新生和肢体成活的影响.方法 制作SD大鼠后肢缺血模型,将动物随机分为3组,每组6只.将构建的HIF-1α基因真核表达载体转染入EPCs后通过尾静脉注射入大鼠体内,并与注射磷酸盐缓冲液(PBS)或EPC的大鼠进行比较,观察转染HIF-1α对新生血管形成的影响.结果 (1)EPC组、HIF组较PBS组肢体恢复率明显增加(P<0.05),EPC组肢体恢复率较HIF组差(P<0.05).(2)与PBS组比较,各时间点中EPC、HIF组微血管密度(MVD)均明显增多(P<0.05),HIF组较EPC组明显增高(P<0.05).(3)HIF组的HIF与血管内皮生长因子(VEGF)蛋白表达较PBS组、EPC组明显增多(P<0.05).PBS组Capase-3的表达较EPC组、HIF组明显增多(P<0.05).(4)术后7 d,各组的大鼠肢体灌注均明显降低,但EPC、HIF组细胞的血流灌注较PBS组多(P<0.01).术后14、21 d,与PBS对照组比较,HIF组的血流灌注恢复明显(P<0.01),EPC组血流灌注较HIF组少(P<0.05).结论 EPCs对大鼠缺血后肢的局部血管新生有明显促进作用,联合应用HIF-1α和EPCs有更优的治疗效果.     

骨内微血管和骨的同步三维显像及定量评价

[目的]评价基于显微CT(Micro-CT)骨内微血管造影进行骨内微血管显影和三维重建在缺血性股骨头坏死(osteonecrosis of femoral head,ONFH)研究中的应用价值,实现在三维空间内同时定量评价骨显微结构及骨矿物量和骨内微血管。[方法]采用局部液氮冷冻和射频加热交替的方法建立鸸鹋塌陷性股骨头坏死动物模型,右侧为手术侧,左侧为对照侧。术后定期进行核磁检查,证实造模成功后自鸸鹋腹主动脉注入亚纳米级硫酸钡明胶混悬液进行下肢血管造影,取下肢股骨标本进行Micro-CT扫描,通过软件进行骨内微血管的二维及三维重建,同时结合Micro-CT骨显微结构研究,并将标本常规HE染色进行组织学检查。[结果]在术后12周证实出现股骨头塌陷,至16周16只动物出现股骨头塌陷。Micro-CT图像骨小梁结构及骨内血管显示清晰,与对照侧相比鸸鹋股骨头坏死塌陷后股骨头部的骨小梁厚度、骨体积分数增加,骨矿物量及骨小梁间距减小,血管体积分数减小,且差异均具有统计学意义。[结论]以亚纳米级硫酸钡作为造影剂,Micro-CT骨内微血管造影可以在不破坏骨标本的基础下清晰的显示骨内微血管,不干扰影像及组织学检查,并实现骨内...     

部分门静脉动脉化对大鼠肝脏血管铸型变化的影响

目的：探讨用部分门静脉动脉化重建肝血流后对肝脏微血管和组织学的影响。方法：建立大鼠部分门静脉动脉化重建肝脏血流的实验模型，观察该模型大鼠肝脏微血管和组织学的变化。结果：行门静脉动脉化手术后1个月动物肝脏组织未见明显异常。血管铸型标本显示肝窦略变粗，较正常充盈，肝窦无明显变形，仍呈放射状分布于中央静脉的周围。墨汁灌注标本显示肝窦内墨汁灌注规整，略显增宽，颜色均匀并加深。结论：部分门静脉动脉化后在近期内不影响肝脏的微血管及组织学结构。     

生肌玉红胶原促进大鼠后肢缺血组织血管新生的实验研究

目的探讨生肌玉红胶原在缺血组织中促进血管新生的作用效果及其作用机理。方法 Wistar大鼠48只按随机配对方法随机均分为空白组、对照组（胶原）及实验组（生肌玉红胶原）3组;在大鼠后肢缺血模型基础上于大鼠右后肢缺血组织中植入不同的胶原制剂,分别于模型制作术后3,7、14及28 d取埋植的胶原制剂标本及标本周围约0.5 cm范围的缺血肌肉组织。通过激光散斑成像系统观察大鼠右后肢缺血模型制作术后各时点的血流灌注情况,采用光度计法测定胶原制剂（生肌玉红胶原）内的血红蛋白含量,采用免疫组化染色方法检测标本周围肉芽组织中的微血管计数,采用实时荧光定量RT-PCR方法检测缺血肌肉组织中各时点低氧诱导因子（HIF）-1αmRNA以及血管内皮生长因子（VEGF）mRNA的表达。结果大鼠右后肢缺血模型制作成功即刻大鼠患肢呈现明显的缺血状态,其血流灌注值明显低于术前（P〈0.01）;在术后3 d却呈明显的充血状态,其血流灌注值明显升高,且略高于术前水平,但差异无统计学意义（P〉0.05）;在术后7～14 d大鼠患肢的血流灌注值呈逐渐下降趋势,至术后28 d又开始回升,该3个时点实验组大鼠患肢的血流灌注值均高于空白组（P〈0.05）,对照组与空白组比较其差异均无统计学意义（P〉0.05）;术后7及14 d实验组大鼠肢体的血流灌注值高于对照组（P〈0.05）。各时点实验组胶原标本内血红蛋白含量均高于对照组（P〈0.01）。实验组微血管计数于术后7及14 d高于对照组（P〈0.05）;实验组术后各时点HIF-1αmRNA及VEGF mRNA的表达水平均高于对照组和空白组（P〈0.05）,而对照组与空白组间比较差异无统计学意义（P〉0.05）。结论生肌玉红胶原通过诱导HIF-1αmRNA及VEGF mRNA血管新生相关基因的表达而改善缺血组织的血流灌注,促进微血管新生,从而达到促进组织修复的功效。     

缺血再灌注对骨骼肌微血管及微循环的影响

为了研究缺血再灌注对骨骨各肌微血管和微循环的影响，采用气囊止血带，在常温下使兔后肢缺血２小时（ｎ＝８）和５小时（ｎ＝８）。在解除止血带后，通过活体显微镜观察再灌注最初１小时期间足背肌腱表面微循环变化，并于再灌注后１小时和７２小时，自胫前肌切取电镜和光镜标本，观察骨骨各肌微血管超微结构和组织形态变化。表现：①肢体缺血２小时再灌注后，虽然少数细静脉内可见轻度红细胞聚集和白细胞贴壁数增加，但腱外膜微循环可迅速恢复，分布也较均匀；骨骨各肌微血管仅有轻微损伤，肌纤维可存活。②肢体缺血５小时再灌注后，腱外膜微循环不能迅速而均匀地恢复，大部分区域发生无复流，细静脉内有大量白细胞粘附和聚集；骨骨各肌微血管内皮细胞显著肿胀，基底膜断裂，间质高度水肿，最终大部分肌纤维坏死。结果证明：缺血再灌注可导致微血管损伤和微循环紊乱，其严重程度取决于缺血时间的长短，并是决定缺血组织实质细胞转归的重要因素之一。     

磁共振成像在泌尿系统疾病中的应用

磁共振成像 (MRI)应用于临床近 2 0年 ,由于其组织分辨率高 ,无创伤 ,无辐射 ,可多方位成像 ,尤其是新技术的应用克服了呼吸运动的伪影 ,能进行尿路成像、肾灌注成像和扩散成像 ,使得 MRI在泌尿系统、前列腺及肾上腺疾病中得到广泛的应用 ,并显示出其巨大的优越性 ,成为替代或补充普通 X线、超声和 CT的重要检查方法。1　肾脏病变肾脏由高信号的肾周脂肪包绕 ,形成自然对比 ,容易识别和显示 ,不用造影剂就能区别肾皮质和肾髓质。常规的自旋回波 (SE)序列、梯度回波(GE)序列 ,以及新近开发应用的同相位反相位梯度回波序列 ,磁共振肾动…     

显示皮肤微血管的透明标本法

我们应用填充剂血管灌注、组织透明处理的方法,观察皮肤与皮瓣的微血管,获得了非常好的效果。本文重点介绍了皮肤透明标本的制作方法及制作体会。     

局灶性脑缺血再灌注后大鼠下丘脑pSTAT3阳性神经细胞分布与局部微血管的关系

目的探讨局灶性脑缺血再灌注大鼠下丘脑磷酸化信号转导与转录激活因子-3 （pSTAT3）阳性神经细胞分布与局部微血管的关系。方法雄性SD大鼠16只,体重280～320 g,随机分成假手术组和脑缺血再灌注组,每组8只。脑缺血组采用线栓法阻塞右侧大脑中动脉120 min;假手术组施以相同的外科操作,但用于栓塞的尼龙线插入颈内动脉3～5 mm,不插到大脑中动脉起始处。再灌注24 h后,先行神经功能缺损评分（NDS）,然后每组随机取3只大鼠多聚甲醛灌流固定后用免疫组化法显示下丘脑pSTAT3阳性神经细胞。每组各取5只大鼠单宁酸.氯化铁灌注法媒染,以显示脑内血管。采用免疫组化法在部分切片上显示pSTAT3阳性神经细胞,观察阳性神经细胞分布和血管的关系。结果再灌注24 h后,脑缺血组NDS评分高于假手术组（P〈0.05）;脑缺血组缺血侧下丘脑出现大量pSTAT3阳性神经细胞,主要见于第三脑室室周、脑膜下,吻侧下丘脑内侧区,以及室旁核和视上核;单宁酸-氯化铁媒染显示下丘脑中微血管丰富的区域pSTAT3免疫反应阳性细胞数量也较多,且多位于血管附近。结论局灶性脑缺血再灌注大鼠下丘脑pSTAT3阳性神经细胞的分布与局部微血管有一定的关系。     

鼠脊髓挫伤后慢性期脊髓微血管网络的三维形态学表征

目的利用同步辐射显微断层成像(SRμCT)表征大鼠脊髓挫伤(SCC)后髓内微血管在慢性恢复期的三维形态计量学特点。方法成年雄性SD大鼠(取自中南大学动物实验中心)48只, 按随机数字表法将其分为对照组、SCC后12周和24周组(n=16/组)。SCC后12周和24周组采用改良的Allen’s打击法建立SCC模型, 对照组仅行椎板切除术。3组大鼠在相应时间点行脊髓血管灌注造影并取标本行SRμCT扫描成像(n=8/组)和血管免疫荧光染色(n=8/组), 组间均值比较采用单因素方差分析。结果在SCC后的慢性恢复期, 大鼠后肢BMS评分仅恢复至正常水平的61.1%～64.7%, 髓内血管再生进入平台期。RECA-1+血管密度在SCC后24周和12周组比较, 差异无统计学意义[(113.12±21.30)/mm2比(100.25±21.81)/mm2, t=1.194, P>0.05], 血管容积比在SCC后24周和12周组比较, 差异无统计学意义[(14.35±1.72)%比(12.61±1.87)%, t=1.936, P>0.05], 分支节点密度在SCC后24周和12周组比较...     

利用同步辐射X线成像技术进行大鼠正常真皮及瘢痕真皮组织的三维结构研究

目的 观察比较大鼠正常真皮与瘢痕真皮组织形态学差异并探寻其结构性规律.方法 切取SD大鼠全层皮肤和创面愈合后3周的瘢痕组织,制备样本进行适当处理,结合同步光源辐射技术、显微CT及相位衬度成像技术进行断层成像,用三维软件进行图像重建. 结果 利用同步辐射光源产生的X射线,使显微CT成为可能;在处理过程中结合相位成像技术,能够清晰地呈现真皮组织结构.正常真皮组织以众多胶原纤维为主,相互盘绕形成橄榄状,并以此为基本单元,按某种形式错落组成.瘢痕真皮组织胶原纤维呈平行排列,部分纤维弯曲,排列混乱. 结论 正常大鼠真皮组织具有稳定的三维结构,其基本框架和组合规律与瘢痕真皮之间存在明显差异.     

MR imaging of cervical disc disease: value GRASS imaging

Since magnetic resonance imaging (MRI) technology has been greatly improved, MRI for cervical disc disease has become widely used in many facilities. Among non-invasive procedures, MRI is regarded as one of the most useful ones. Conventional myelography, CT myelography, and MRI were performed on 10 patients with cervical disc disease. The authors discussed the correlation between conventional myelography, CT myelography, and MRI as regards their ability to determine the localization and the laterality of disc protrusion and osteophyte. In our MRI study, we use both short-echo (SE) images and GRASS images. The parameters of our GRASS included 5mm-thick sections. TR = 200, TE = 20, and flip angles of 10 degrees. This pulse sequence generates images with high signal cerebrospinal fluid (CSF), resulting in a high-contrast CSF-spinal cord, osteophyte, and disc protrusion. As yet, although it easily shows the localization and laterality of the disc and/or osteophyte, image quality of the GRASS is not yet sufficient to allow us to evaluate detailed deformity of the spinal cord and nerve root. The authors stress the usefulness of this GRASS image for the evaluation of suspected cervical disc disease.     

Osteoarthritis--radiology imaging

Osteoarthritis is degenerative arthritis. On radiograms it is characterised with joint place narrowing, subchondral bone sclerosis, and formation of cystic and osteophitic changes.     

Recent advances in MR imaging: FLAIR imaging

Fluid-attenuated inversion recovery (FLAIR) imaging is a technique that increases the sensitivity of magnetic resonance imaging to detect central nervous system (CNS) diseases characterized by an increase in interstitial water content such as brain tumors, cerebral infarcts, and gliotic scars. A role for this technique in subarchnoid disease processes such as hemorrhage and epidermoid tumor is also being revealed.     

Adrenal imaging

The problems inherent in visualizing the adrenal glands are illustrated by the variety of imaging modalities that have been employed. Although urography has been the basic screening examination, one can make a sound argument for CT as the procedure of choice in the evaluation of the patient with suspected adrenal pathology. Angiography, venous sampling, and radionuclide studies continue to have a role in selected problem cases. This article reviews the usefulness of available modalities in the context of the clinical evaluation of adrenal disease.     

Patellofemoral imaging

Imaging of the patella and patellofemoral joint cannot be isolated from imaging of the knee anymore than the function of the patellofemoral joint can be separated from the function of the entire knee. Therefore, the current author will focus on imaging of the patellofemoral joint yet integrate this with the entire knee. Because radiographs and other imaging techniques are adjuncts to the history and physical examination, and specifically an extension of the physical examination, each view or technique must be selected thoughtfully to yield the most useful and accurate information possible. Imaging techniques range from relatively inexpensive to very costly, yet the amount of useful information may not show a positive correlation with the cost. Only by integrating the history, physical examination, and the best imaging techniques can the clinician locate the abnormality, determine its cause, and plan a proper course of treatment. Radiographic imaging of the patellofemoral joint requires attention to detail on the part of the technician and knowledge of these techniques on the part of the clinician who orders and interprets the results. Understanding these concepts will help achieve everyone's goal: high-quality and cost-effective orthopaedic care.     

Scrotal imaging

Color Doppler ultrasound has been the mainstay for the evaluation of the scrotum in a variety of clinical settings. However, ultrasonography results are not always accurate or conclusive. Despite the high cost and limited availability, magnetic resonance imaging with the dynamic contrast-enhanced subtraction technique provides accurate information on morphology as well as blood flow. Infrared scrotal thermography increases accuracy in the diagnosis of varicocele. This article attempts to summarize recent advances in scrotal imaging with regard to testicular and extratesticular disorders.