等距和非等距前交叉韧带重建的对比实验

目的 观察等距和非等距前交叉韧带(anterior cruciate ligament，ACL)重建对膝关节功能的影响。方法 采用新鲜尸体观察等距ACL的解剖结构，在尸体和模型上重建等距和非等距ACL，分别观察重建后ACL长度和胫骨平台表面压强的变化。结果 等距ACL的重建在膝关节的全范围活动中长度的变化值最小，胫骨平台所受的压强也最小。结论 只有等距的ACI。的重建才能恢复膝关节的正常生理功能，而非等距重建的ACL会造成膝关节的不稳定(或活动受限)，或者使膝关节表面的压强增加。     

慢性粒细胞白血病骨髓细胞体外培养净化作用实验研究

目的 :采用 FISH方法直接在干细胞水平对慢性粒细胞白血病 (CML )患者自体骨髓体外培养前后的间期细胞进行 bcr/abl融合基因检测 ,从而探讨 CML 骨髓细胞体外培养对自体骨髓移植物的净化作用。方法 :分离初治的慢性期 Ph+ CML 7例骨髓单个核细胞 (MNCs) ,体外培养 10 d,用免疫磁珠 (MACS)富集培养前后的 CD34+ 细胞 ,通过流式细胞仪检测培养前后 MNCs中 CD34+ 干细胞比例 ,然后用 FISH方法检测其中 bcr/abl融合基因 ,同时分别用正常人细胞及 K5 6 2细胞株作阴性及阳性对照。结果 :(1) 7例患者骨髓细胞培养前后 CD34+ 细胞中 bcr/abl融合基因平均检出率分别为 85 .3%± 4 .9%和 78%± 5 .1% ,有统计学意义 (P<0 .0 5 ) ,(2 )培养前培养体系中 CD34+ 细胞数量为 (6 .0 6 0± 1.5 6 4 )× 10 5个 ,培养后体系中的 CD34+细胞数量为 (5 .974± 1.4 2 4 )× 10 5个 ,两者无明显差异 (P>0 .0 5 )。 (3)在对照组中假阳性率为 2 .5 % ,假阴性率为 2 %。结论 :自体骨髓细胞体外培养对 CML 病人的骨髓肿瘤细胞有一定程度的净化作用 ;FISH技术直接在干细胞水平检测 bcr/abl融合基因 ,且能定量分析 ,较传统方法更适合对骨髓净化进行评价 ,为骨髓净化提供了一种更方便、可靠的评定方法     

Engineering angiogenesis following spinal cord injury: a coculture of neural progenitor and endothelial cells in a degradable polymer implant leads to an increase in vessel density and formation of the blood–spinal cord barrier

Angiogenesis precedes recovery following spinal cord injury and its extent correlates with neural regeneration, suggesting that angiogenesis may play a role in repair. An important precondition for studying the role of angiogenesis is the ability to induce it in a controlled manner. Previously, we showed that a coculture of endothelial cells (ECs) and neural progenitor cells (NPCs) promoted the formation of stable tubes in vitro and stable, functional vascular networks in vivo in a subcutaneous model. We sought to test whether a similar coculture would lead to the formation of stable functional vessels in the spinal cord following injury. We created microvascular networks in a biodegradable two-component implant system and tested the ability of the coculture or controls (lesion control, implant alone, implant + ECs or implant + NPCs) to promote angiogenesis in a rat hemisection model of spinal cord injury. The coculture implant led to a fourfold increase in functional vessels compared with the lesion control, implant alone or implant + NPCs groups and a twofold increase in functional vessels over the implant + ECs group. Furthermore, half of the vessels in the coculture implant exhibited positive staining for the endothelial barrier antigen, a marker for the formation of the blood–spinal cord barrier. No other groups have shown positive staining for the blood–spinal cord barrier in the injury epicenter. This work provides a novel method to induce angiogenesis following spinal cord injury and a foundation for studying its role in repair.     

血管紧张素(1-7)和依那普利拉对烧伤血清离体灌注大鼠心脏功能的影响

Objective To investigate effects of angiotcnsin ( 1-7 ) [ Ang( 1-7 ) ] and enalaprilat on function of isolated rat heart perfused by burn serum. Methods Eighty SD rats were used to prepare burn serum. Hearts of another 24 SD rats were isolated to reproduce Langendorff perfusion model. The rat hearts were divided into different groups with different perfusion fluids as K-H buffer group, K-H buffer containing 20% burn serum group ( burn serum group) , K-H buffer containing 20% burn serum and 2 μg/mL enala-prilat group (enalaprilat group), and K-H buffer containing 20% burn serum and 1 nmol/mL Ang(1-7) group [ Ang(1-7) group]. The rat hearts were perfused for 30 mins with each of above-mentioned fluids in different groups. Then left ventrieular systolic pressure (LVSP) , left ventricular end diastolic pressure ( LV-EDP) , ± dp/dt max, coronary flow(CF) , level of creatine kinase (CK) and lactate dehydrogenase (LDH) in respective coronary effluent were determined. Results Compared with LVSP ( 11.2 ± 1.0 kPa, 1 kPa = 7.5 mm Hg), +dp/dt max (642±53 kPa/s), -dp/dt max (380±61 kPa/s) and CF level in K-H buffer group, CF, LVSP(5.9±0.8, 8.0±1.1, 8.9±1.3 kPa, respectively), +dp/dt max(275±37, 454±48, 479±63 kPa/s, respectively), - dp/dt max ( 135±35, 219±47, 277±58 kPa/s, respectively ) of burn serum group, those levels in Ang(1-7) group, and enalaprilat group were decreased obviously(P<0.05 or P <0.01 ), but LVEDP, level of CK and LDH in coronary effluent were increased. Compared with those parameters in burn serum group, CF, LVSP, ±dp/dt max of Ang(1-7) group and enalaprilat group were increased obviously(P<0.05 or P<0.01), and LVEDP, level of CK and LDH in coronary effluent were decreased obviously(P<0.01). Conclusions Ang(1-7) and enalaprilat can effectively improve left ventricular function of isolated rat heart perfused by burn serum and mitigate myocardial injury.     

急性坏死性胰腺炎大鼠胰腺高迁移率族蛋白-1的表达及意义

目的探讨急性坏死性胰腺炎(ANP)大鼠模型胰腺组织高迁移率族蛋白-1(HMGB1)的表达及其意义。方法72只大鼠随机分成3组,即对照组、ANP组和正丁酸钠治疗组(治疗组)。逆行性胰胆管注射5%牛磺胆酸钠建立ANP模型。ELISA法检测血清TNF-α和IL-1β水平;RT-PCR法检测胰腺组织HMGB1 mRNA的表达,并观察其病理变化。结果ANP组血清TNF-α和IL-1β水平在ANP建模后6h达高峰,12h下降。ANP组大鼠胰腺组织HMGB1 mRNA表达水平在ANP后12h明显升高,至24h仍维持在较高水平。治疗组胰腺组织HMGB1 mRNA表达水平在ANP后12,24h明显低于ANP组(P<0.05),且同期胰腺损伤比ANP组轻(P<0.05)。建模后24h血清TNF-α和IL-1β水平ANP组与治疗组间差异无显著性。结论HMGB1作为晚期炎症因子参与了ANP的全身炎症反应。HMGB1抑制剂正丁酸钠能降低ANP大鼠胰腺组织HMGB1基因表达水平,减轻ANP胰腺组织的损伤。     

脉冲电磁场影响人骨髓基质干细胞缝隙连接通讯的实验研究

目的研究脉冲电磁场(PEMFs)对人骨髓基质干细胞(hBMSCs)缝隙连接所介导细胞间通讯(GJIC)的影响。方法透射电镜观察BMSCs超微结构,应用荧光漂白恢复(FRAP)技术,通过激光共聚焦显微镜检测hBM-SCs经PEMFs刺激后GJIC的功能变化。结果经PEMFs刺激后的hBMSCs,平均荧光漂白恢复率为(64.12±0.83)%,较对照组犤(35.26±0.76)%犦有显著性增加(P<0.05)。结论PEMFs刺激能促进hBMSCs的缝隙连接通讯功能。     

Increased NoGo-anteriorisation in first-episode schizophrenia patients during Continuous Performance Test

OBJECTIVE: NoGo-stimuli during a Continuous Performance Test (CPT) activate prefrontal brain structures such as the anterior cingulate gyrus and lead to an anteriorisation of the positive electrical field of the NoGo-P300 relative to the Go-P300, so-called NoGo-anteriorisation (NGA). NGA during CPT is regarded as a neurophysiological standard index for cognitive response control. While it is known that patients with chronic schizophrenia exhibit a significant reduction in NGA, it is unclear whether this also occurs in patients undergoing their first-episode. Thus, the aim of the present study was to determine NGA in a group of patients with first-episode schizophrenia by utilizing a CPT paradigm. METHODS: Eighteen patients with first-episode schizophrenia and 18 matched healthy subjects were investigated electrophysiologically during a cued CPT, and the parameters of the Go- and NoGo-P300 were determined using microstate analysis. Low resolution tomography analysis (LORETA) was used for source determination. RESULTS: Due to a more posterior Go- and a more anterior NoGo-centroid, NGA was greater in patients than in healthy controls. LORETA indicated the same sources for both groups after Go-stimuli, but a more anterior source in patients after NoGo-stimuli. In patients P300-amplitude responses to both Go- and NoGo-stimuli were decreased, and P300-latency to NoGo-stimuli was increased. After the Go-stimuli false reactions and reaction times were increased in patients. CONCLUSIONS: Attention was reduced in patients with first-episode schizophrenia, as indicated by more false reactions, prolongation of reaction time, P300-latencies and by a decrease in P300-amplitude. Significantly however, the NGA and prefrontal LORETA-sources indicate intact prefrontal brain structures in first-episode schizophrenia patients. Previously described changes in this indicator of prefrontal function may be related to a progressive decay in chronic schizophrenia. SIGNIFICANCE: The results support the idea of a possible new biological marker of first episode psychosis, which may be a useful parameter for the longitudinal measurement of changing prefrontal brain function in a single schizophrenia patient.     

Autologous implantation of chondrocytes on a solid collagen scaffold: clinical and histological outcomes after two years of follow-up

Abstract From our overall experience in 56 patients, we here report the treatment with matrix-induced autologous chondrocyte implantation (MACI) of 35 patients suffering from knee cartilage defects measuring about 4 cm², and followed for a minimum of 6 months. A total of 36 knees were treated (1 patient on both knees) and clinically observed for 22 months (in some cases for over 39 months), in accordance with a standardised protocol. Subjective parameters (pain, well-being, functional state, symptoms during specific activity) and objective outcomes (IKDC score and Lysholm and Tegner scores) were recorded. One or 2 years after implantation, some biopsies of the regenerated cartilage were histologically evaluated. The subjective parameters (VAS pain score, 2.80±1.49, p<0.0001; change vs. basal score, 2.72) promptly normalized after 1 month, as did the objective ones (IKDC score after 6 months, 1.53±0.59, p<0.0001; change vs. basal score, 1.78). Similar results were observed after the treatment of a femoropatellar kissing lesion. The three cartilage biopsies that were analysed from different patients showed a tissue positivity to immunohistochemical markers of hyaline cartilage. The conclusions of this preliminary analysis are that the clinical outcome and histological evaluation suggest that MACI is able to relieve pain and restore the functionality of the knee, and that the treatment appears capable of regenerating hyaline cartilage.     

Poststroke DNA immunization against neurite growth inhibitors is beneficial to the recovery from local cerebral ischemia in rats

BACKGROUND： Inhibitory signals, i.e. neurite growth inhibitors （NGIs）, presenting on central nervous system （CNS） myelin have been shown to play a crucial role in inhibiting lesioned axonal sprouting and leading to less functional recovery. Vaccines targeting NGIs may provide multifactorial protection against brain insults by overcoming the inhibitory effects of these NGIs and boosting the body＇s immune repair mechanisms. OBJECTIVE： To evaluate the effect of poststroke DNA immunization against NGIs on the rehabilitation for sensorimotor function of rat models of local cerebral ischemia. DESIGN： Completely randomized grouping design, and controlled experiment. SETTING： Brain Injury Research Laboratory, Department of Neurosurgery, National Neuroscience Institute, Singapore. MATERIALS： Sixty adult male Sprague-Dawley rats ranging in age from 45 to 120 days and in weight from 180 to 250 grams were provided by Animal Center of Department of Anatomy, Faculty of Medicine, National University of Singapore. pcDNA3.1（＋）-neurite growth inhibitors （pcDNA-NGIs） a gift was provided by Dr. Xiao from Department of Clinical Research, Singapore General Hospital, Singapore. METHODS： The experiment was carried out at Brain Injury Research Laboratory, Department of Neurosurgery, National Neuroscience Institute, Singapore from August 2003 to April 2005. （1）The involved rats were randomized into 3 groups： pcDNA-NGIs group （group A）, pcDNA3.1 （＋） group （group B） and model group （group C）, with 20 rats in each group. Left focal cerebral ischemia （FCI） was permanently induced through middle cerebral artery occlusion （MCAO） with the assistance of an operating microscope. Successful MCAO was determined by a 20% decrease to baseline in the ipsilateral cerebral blood flow. 100 μg of pcDNA-NGIs eluted in phosphate-buffered saline （PBS） was intramuscularly injected into the tibial muscle once a week after MCAO for 6 weeks in group A. As control, pcDNA3.1 （＋） was also administrated in the same way in group B and nothing was administrated in group C. （2） The modified neurological severity score （mNSS）, a composite of motor, sensory, reflex and balance tests, was used to test the sensorimotor deficit. The mNSS was graded on a scale of 0 - 18, i.e. normal score was 0, maximal deficit score was 18, and 1 point was warded for the inability to perform the tasks or the lack of a tested reflex. （3） The newly generated axons of corticorubral projection were traced by stereotaxic guided injection of 100 g/L biotinylated dextran amine. Rats were sacrificed two weeks after tracing, and cryostat coronal sections of midbrains （30μm） were reacted to BDA according to the manufacturer＇s instruction by the free-floating method. Images were captured on a DM RXA2 LEICA Microscope with a Spot Digital Camera system （Germany）, and the numbers of labeled axons on the denervated side in four standard coronal sections including the red nucleus were manually quantified. MAIN OUTCOME MEASURES： （1） The number of newly generated axons of corticorubral projection. （2）The improvement in sensorimotor deficit. RESULTS： All the involved 60 rats entered the stage of final analysis. （1） The number of newly generated axons of corticorubral projection of rats： Only ipsilateral axons of CRP were noted with little evidence of fibers crossing to the contralateral red nucleus in rats of groups B and C. More BDA-positive fibers crossing the midline and terminating in the contralateral red nucleus in appropriate target areas mirroring the non-differentiated red nucleus were found in rats of group A. Quantitative analysis showed that BDA-labeled axons in the denervated side of rats in group A were more than those in group B （P 〈 0.05）. （2） Improvement in sensorimotor deficit of rats： At 2 weeks after immunization, significant improvement in sensorimotor deficit was found in rats of group A. There were significant differences of improvement in sensorimotor deficit of rats between group A and group B or group C at 12 and 14 weeks after immunization （P 〈 0.05）. CONCLUSION： （1） Poststroke DNA immunization against NGIs leads to increased sensorimotor recovery following FCI and compensatory newly growth of axons from corticorubral projection.