高强度聚焦超声非热效应对兔肝VX2肿瘤超微结构及细胞凋亡的影响

目的：观察高强度聚焦超声(high-intensity focused ultrasound,HIFU)热效应和非热效应损伤后兔肝VX2肿 瘤的微观形态学变化。方法：将40只兔肝VX2肿瘤模型大白兔随机分为热效应组(n=20)和非热效应组(n=20),每组 于治疗后即刻及3,7,14 d分别随机处死5只,分析超微结构、凋亡相关蛋白表达及细胞凋亡情况。结果：电镜显 示HIFU辐照后各时间点非热效应组的组织细胞破坏程度较热效应组严重。消融后两组交界区凋亡相关蛋白即刻及 3 d血管内皮生长因子(vascular endothelial growth factor,VEGF)呈低水平表达,7~14 d均逐渐升高,各时间点两组相比 差异均无统计学意义(均P>0.05);caspase-3治疗后3 d表达达到高峰,3与7 d时非热效应组表达明显高于热效应组(均 P<0.05);NF-κB的表达3 d时开始增加,7 d达高峰,14 d开始下降,各时间点两组相比差异无统计学意义(均P>0.05)。 TUNEL检测HIFU治疗后交界区凋亡阳性细胞,发现3与7 d非热效应组高于热效应组(均P<0.01),凋亡指数分别为 (28.60±1.14)%,(21.80±1.92)%和(21.00±1.58)%,(14.80±1.48)%。结论：HIFU热效应及非热效应机制均能诱导交界区凋 亡产生,而后者效果更为强烈。     

Microencapsulated rabbit adipose stem cells initiate tissue regeneration in a rabbit ear defect model

Cell‐based tissue engineering can promote cartilage tissue regeneration, but cell retention in the implant site post‐delivery is problematic. Alginate microbeads containing adipose stem cells (ASCs) pretreated with chondrogenic media have been used successfully to regenerate hyaline cartilage in critical size defects in rat xiphoid suggesting that they may be used to treat defects in elastic cartilages such as the ear. To test this, we used microbeads made with low viscosity, high mannuronate medical grade alginate using a high electrostatic potential, and a calcium cross linking solution containing glucose. Microbeads containing rabbit ASCs (rbASCs) were implanted bilaterally in 3 mm critical size midcartilage ear defects of six skeletally mature male New Zealand White rabbits (empty defect; microbeads without cells; microbeads with cells; degradable microbeads with cells; and autograft). Twelve weeks post‐implantation, regeneration was assessed by microCT and histology. Microencapsulated rbASCs cultured in chondrogenic media expressed mRNAs for aggrecan, Type II collagen, and Type X collagen. Histologically, empty defects contained fibrous tissue; microbeads without cells were still present in defects and were surrounded by fibrous tissue; nondegradable beads with rbASCs initiated cartilage regeneration; degradable microbeads with cells produced immature bone‐like tissue, also demonstrated by microCT; and autografts appeared as normal auricular cartilage but were not fully integrated with the tissue surrounding the defect. Elastin, the hallmark of auricular cartilage, was not evident in the neocartilage. This delivery system offers the potential for regeneration of auricular cartilage, but vascularity of the treatment site and use of factors that induce elastin must be considered.     

家兔下腔静脉血栓模型建立的实验研究

目的：探讨通过手术在家兔下腔静脉内置入螺旋铜丝建立下腔静脉血栓模型的可行性及成功率。方法将30只家兔分为血栓组（25只）与对照组（5只）。血栓组实验兔通过手术暴露下腔静脉,将自制长约3 cm直径约3 mm螺旋铜丝穿刺置入下腔静脉,止血后将自制U形铜丝夹于螺旋铜丝近心端下腔静脉收紧,留缝隙约2 mm,缝合腹膜、肌肉及皮肤。对照组进行与血栓组相同的手术过程,但下腔静脉不置入螺旋铜丝。1d后处死解剖2组实验兔,观察血栓组下腔静脉血栓形成情况,计算造模成功率,对照组观察下腔静脉血流情况。血栓组取血栓行HE染色病理检查确定血栓性质。结果血栓组25只实验兔下腔静脉管壁完好。23只实验兔下腔静脉内可见血栓形成,红色血栓与白色血栓沿螺旋铜丝间或存在,造模成功率92％（23/25）。2只实验兔造模失败。对照组5只实验兔下腔静脉内未见血栓形成。血栓组血栓病理证实均为新鲜混合血栓。结论本方法建立下腔静脉血栓模型成功率高,血栓病理符合深静脉血栓特点,可用于静脉血栓的实验研究。     

Effect of a Collagen Membrane Combined With a Porous Titanium Membrane on Exophytic New Bone Formation in a Rabbit Calvarial Model

Background: Previous studies showed that the use of a porous titanium membrane (TM) for exophytic bone regeneration does not effectively inhibit the infiltration of undesired tissue. Therefore, this study examines the effect of resorbable collagen membranes, such as cross‐linked type I collagen membrane (BA) and double‐layered porcine collagen membrane (BG), on the promotion of exophytic bone formation in guided bone regeneration when used in conjunction with a porous TM. Methods: Thirty‐six male New Zealand white rabbits were used in this study. Six rabbits were allotted to each test group. After decorticating the parietal bone, with or without filling the inner space with a freeze‐dried cortical bone allograft (OG), the collagen membranes were fixed with metal pins. The experimental groups were divided into the following six groups: TM only, TM + OG, TM + BA, TM + BG, TM + OG + BA, and TM + OG + BG. The experimental animals were sacrificed at 8 and 16 weeks after surgery. Non‐decalcified specimens were prepared and processed for histologic observations. The newly formed bone (percentage) was measured histomorphometrically. Results: BG combined with TM promoted new bone formation and maturation by inhibiting the infiltration of connective tissue. However, BA had no significant effect on new bone formation. The amount of new bone formation was higher at 16 weeks than at 8 weeks, but the difference was not significant. At 16 weeks, the best result for newly formed bone was with TM + OG + BG, with a significant difference from TM alone and TM + BA. Conclusions: Regardless of the use of graft materials, BG combined with TM promoted more bone formation than BA combined with TM or TM alone. Thus, using a commercial collagen membrane to cover a TM can promote new exophytic bone formation.     

新生兔气管软骨细胞的生物学特性

 目的：探讨体外分离培养的新生兔气管软骨细胞的生物学特性。方法：通过酶消化法体外分离培养新生兔气管软骨细胞;倒置显微镜观察软骨细胞形态及生长状况;电镜观察软骨细胞超微结构;运用real-time PCR、免疫细胞化学染色和甲苯胺蓝染色检测气管软骨细胞分泌的细胞外基质成分。结果：体外分离、培养的兔气管软骨细胞呈短小三角形或不规则形贴壁生长。超微结构显示细胞较多突起,孔隙较多,胞质丰富,细胞器发达,细胞内可见大量蛋白分泌物。软骨细胞表达I、II型胶原、蛋白聚糖等,以II型胶原和蛋白聚糖表达为主。免疫细胞化学染色II型胶原和SOX9阳性,I型胶原弱阳性。甲苯胺蓝染色阳性。结论：适宜的酶消化单层培养法获得的新生兔气管软骨细胞具有分泌软骨细胞外基质成分的特性,可初步为体外构建组织工程气管治疗新生兔气管狭窄的实验研究提供种子细胞。     

软骨下钻孔联合软骨源性形态发生蛋白缓释系统修复膝关节软骨缺损

背景：有研究表明软骨源性形态发生蛋白等因子在诱导细胞分化、促进软骨修复过程中起到重要调节作用;软骨下钻孔治疗软骨缺损在临床已广为应用,但其与软骨源性形态发生蛋白等因子联合应用的相关研究至今少有报道。 目的：将软骨下钻孔技术与关节内注射透明质酸/软骨源性形态发生蛋白1缓释载药微球（hyaluronic acid-coated cartilage-derived morphogenetic protein-1,HA/CDMP-1）相结合,观察其对软骨缺损修复的效果,并通过与单纯钻孔组及HA/CDMP-1微球组治疗结果比较,观察两者有无协同效应。 方法：用透明质酸包被软骨源性形态发生蛋白制备缓释微球冻干保存,制备兔实验膝关节全层关节软骨缺损模型,随后将兔随机分为模型组、钻孔组、HA/CDMP-1微球组和钻孔联合HA/CDMP-1微球组,分别采用生理盐水关节腔注射,软骨缺损区钻孔,HA/CDMP-1微球关节腔注射,软骨下钻孔并HA/CDMP-1微球注射。 结果与结论：建模后8,12,16周,组织学观察结果提示,钻孔联合HA/CDMP-1微球组软骨缺损区修复组织覆盖面积明显高于其他3组（P 〈0.05）;甲苯胺蓝染色和荧光定量PCR检测显示,钻孔联合HA/CDMP-1微球组修复的软骨组织中蛋白多糖和Ⅱ型胶原mRNA的表达明显高于其他3组（P〈0.01或P〈0.05）。结果证实,软骨下钻孔与关节腔内注射 HA/CDMP-1联合应用修复兔膝关节软骨缺损近期疗效满意,提示两者可能发生协同作用。     

动脉粥样硬化兔主动脉平滑肌细胞钙激活钾通道变化及意义

目的　探讨动脉粥样硬化 (atherosclerosis,AS)兔主动脉平滑肌细胞钙激活钾 (Calcium activatedpotassium ,KCa)通道变化及意义。方法　 2 0只健康新西兰白兔随机分为AS组和对照组 ,每组 10只。用酶消化法获取单个主动脉平滑肌细胞 ,通过膜片钳记录技术检测AS兔主动脉平滑肌细胞KCa通道的活性 ,并在浴液中分别加入不同浓度的Ca2 + ,实时采样记录通道的开放概率 (Po)、平均开放时间 (To)、平均关闭时间 (Tc)和电流幅值 (Am) ,以加钙前作为对照组观察上述参数的变化。结果　AS组KCa通道的活性明显高于对照组。结论　AS血管平滑肌细胞KCa通道的活性明显增加 ,可能是AS血管发生代偿性扩张的机制之一。     

Emulsified halothane produces long-term epidural anesthetic effect: a study in rabbits

Previous studies have demonstrated that volatile anesthetics could produce local anesthesia. Emulsified isoflurane at 8% has been reported to produce epidural anesthetic effect in rabbits. This study was designed to investigate the long-term epidural anesthetic effect of emulsified halothane in rabbits. In this study, 40 healthy adult rabbits (weighting 2.0-2.5 kg) with an epidural catheter were randomly divided into 4 groups (n=10/group), receiving epidural administration of 1% lidocaine (lido group), 8% emulsified isoflurane 1ml (8% E-iso group), 8% emulsified halothane (8% E-Halo group) and 12% emulsified halothane (12% E-Halo group). After administration, sensory and motor functions as well as consciousness state were assessed until 60 minutes after sensory and motor function returned to its baseline or at least for 180 min. After epidural anesthesia, all the rabbits were continuously observed for 7 days and sacrificed for pathological evaluations. As a result, all the four study solutions produced typical epidural anesthesia. Onset times of sensory and motor function blockade were similar among the four groups (P>0.05). Duration of sensory blockade in 12% E-Halo group (83±13 min) was significantly longer than other groups: 51±12 min in 8% E-Halo group (P<0.01), 57±8 min in 8% E-iso group (P<0.01) and 47±9 min in lido group (P<0.01). Duration of sensory blockade in 8% E-iso group is longer than lido group (P<0.05). Duration of motor blockade in 12% E-Halo group (81±12 min) was also significantly longer than other groups: 40±8 min in 8% E-Halo group (P<0.01), 37±3 min in 8% E-iso group (P<0.01), 37±6 min in lido group (P<0.01). Normal consciousness was found in the rabbits from 8% E-Halo, 8% E-iso and lido groups while there were four rabbits in 12% E-Halo group (4/10) showed a light sedation. For all the rabbits, no pathological injury was found. The present study demonstrates that emulsified halothane produces reversible concentration-dependent epidural anesthesia and at 12% (v/v), emulsified halothane could produce long-term anesthesia without pathological injury.     

Low-Polydispersity Glucose Polymers as Osmotic Agents for Peritoneal Dialysis

♦ Background:

Peritoneal dialysis (PD) solutions containing icodextrin as the osmotic agent have advantages during long dwells. The glucose polymers that constitute icodextrin are a heterogeneous mix of molecules with a polydispersity [ratio of weight-average to number-average molecular weight (Mw/Mn)] of approximately 2.6. The present study evaluates whether modifications in the polydispersity and concentration of glucose polymers can improve ultrafiltration (UF) without an associated increase in carbohydrate absorption (CA).

♦ Methods:

Computer simulations using a three-pore model of peritoneal transport during a long dwell in PD patients predict that, in general, compared with 7.5% icodextrin, glucose polymers with a Mw greater than or equal to 7.5 kDa, a polydispersity less than 2.6, and concentrations greater than 7% could achieve higher UF without higher CA. Based on the simulations, we hypothesized that, compared with 7.5% icodextrin, glucose polymers with a Mw of 18 – 19 kDa and a polydispersity of 2.0 at 11% concentration could achieve higher UF without a higher CA. We tested this hypothesis in experimental studies using 8-hour dwells in New Zealand White rabbits. In those studies, UF was measured by complete fluid collection, and CA was measured by subtracting the total carbohydrate in the collected fluid from the carbohydrate initially infused.

♦ Results:

The UF was higher with 11% 19 kDa glucose polymer than with 7.5% icodextrin (mean ± standard deviation: 89 ± 31 mL vs 49 ± 15 mL; p = 0.004) without higher CA (5.2 ± 0.9 g vs 5.0 ± 0.9 g, p = 0.7). Similar results were seen with the 11% 18 kDa glucose polymer, which, compared with 7.5% icodextrin, resulted in higher UF (mean ± standard deviation: 96 ± 18 mL vs 66 ± 17 mL; p < 0.001) without higher CA (4.8 ± 0.7 g vs 5.2 ± 0.6 g, p = 0.2).

♦ Conclusions:

The findings demonstrate that, compared with 7.5% icodextrin solution, long-dwell PD solutions containing 11% glucose polymers with a Mw of 18–19 kDa and a polydispersity of 2.0 can provide higher UF without higher CA.     

Robust hippocampal responsivity during retrieval of consolidated associative memory

A contentious point in memory research is whether or not the hippocampus plays a time‐limited role in the consolidation of declarative memories. A widely held view is that declarative memories are initially encoded in the hippocampus, then transferred to the neocortex for long‐term storage. Alternate views argue instead that the hippocampus continues to play a role in remote memory recall. These competing theories are largely based on human amnesic and animal lesion/inactivation studies. However, in vivo electrophysiological evidence supporting these views is scarce. Given that other studies examining the role of the hippocampus in remote memory retrieval using lesion and imaging techniques in human and animal models have provided mixed results, it would be particularly useful to gain insight at the in vivo electrophysiological level. Here we report hippocampal single‐neuron and theta activity recorded longitudinally during acquisition and remote retrieval of trace eyeblink conditioning. Results from conditioned rabbits were compared to those obtained from yoked pseudo‐conditioned control rabbits. Results reveal continued learning‐specific hippocampal activity one month after initial acquisition of the task. Our findings yield insight into the normal physiological responses of the hippocampus during memory processes and provide compelling in vivo electrophysiological evidence that the hippocampus is involved in both acquisition and retrieval of consolidated memories. © 2014 The Authors Hippocampus Published by Wiley Periodicals, Inc.