冰微粒致孔制备聚羟基丁酸酯(PHB)多孔支架

目的以冰粒子为致孔剂,用粒子滤出—冷冻干燥复合工艺制备PHB多孔支架。方法本实验以氯仿为溶剂,将PHB溶液浇入预先排列好的冰微粒空隙中,采用真空渗流方法制备冰微料-PHB复合体,液氮冷却成型后,用粒子滤出—冷冻干燥复合工艺制备多孔支架。通过扫描电镜(SEM)观测,研究该制备工艺对支架形貌的影响。结果制备的块状三维多孔支架孔径可调、孔隙结构良好、孔隙连通度高。结论本文工艺所制备的多孔支架无致孔剂残留,孔隙率高,孔隙连通度高,制备过程不会损害材料的生物相容性,可安全地用于组织工程可降解聚合物多孔支架的制备。     

Amelioration in Hepatic Insulin Sensitivity by Reduced Hepatic Lipid Accumulation at Short-Term After Roux-en-Y Gastric Bypass Surgery in Type 2 Diabetic Rats

Background

Previous studies showed that early after Roux-en-Y gastric bypass (RYGB), there is a remarkable improvement in type 2 diabetes, which is characterized by insulin resistance. This study aims to gain insight into the underlying mechanisms of this effect. We determined the acute effects of RYGB on hepatic and peripheral insulin sensitivity.

Methods

A rat model of type 2 diabetes was established using high-fat diet combined with streptozotocin (30 mg/kg, ip). Animals were divided into four groups: diabetic, diabetic RYGB, diabetic RYGB sham, and control rats. Hyperinsulinemic-euglycemic clamps with tracer infusion were completed at 2 weeks postoperatively to assess insulin sensitivity. Triglyceride concentration in liver and muscle tissues was determined. Protein kinase C (PKC) membrane translocation, protein expression of phospho-c-Jun NH₂-terminal kinase (JNK), and phospho-IκB kinase β (IKKβ) were assessed with western blot. Malondialdehyde (MDA) and superoxide dismutase (SOD) activities in the liver were also measured.

Results

RYGB surgery significantly improved hepatic insulin sensitivity index and decreased hepatic triglyceride concentration (P?<?0.05), without an improvement in peripheral insulin sensitivity. Membrane translocation of PKC-ε, PKC-δ, and PKC-θ; the ratio of MDA to SOD; and the expression of p-JNK and p-IKKβ in the liver were lower in the diabetic RYGB group than in the diabetic group.

Conclusions

Diabetes remission was induced at short term after RYGB. The improvement of hepatic tissue lipotoxicity decreased the activation of certain PKC isoforms, the activity of JNK and IKK inflammatory signaling pathways, and the degree of oxidative stress. Furthermore, the hepatic insulin sensitivity was ameliorated, which is possibly a mechanism for early diabetes remission.     

单倍体异基因淋巴细胞输注在小鼠移植物抗宿主病和移植物抗肿瘤效应中的意义

目的建立小鼠免疫耐受模型,探讨单倍体异基因淋巴细胞输注在小鼠移植物抗宿主病（GVHD）和移植物抗肿瘤（GVT）效应中的意义。方法64只BALB／C雌性小鼠按随机数字表法分为4组,每组16只。对照组：实验第4天接种肿瘤细胞（小鼠大肠癌CT26细胞株配制成1×10^7／mL的瘤细胞悬液,接种到雌性小鼠右腋皮下）后不予任何特殊处理;化疗组：实验第4天接种肿瘤细胞,第7天开始化疗;供体淋巴细胞输注（DLI）组：实验开始时进行预处理,第4天接种肿瘤细胞,第13、15、17天输注单倍体异基因淋巴细胞（雄性BALB／C小鼠制备的脾淋巴细胞）;化疗＋DLI组：实验开始时进行预处理,第4天接种肿瘤细胞,第7天开始化疗,第13、15、17天输注单倍体异基因淋巴细胞。预处理方案为输注单倍体异基因淋巴细胞＋环磷酰胺＋输注单倍体异基因淋巴细胞。化疗方案为小鼠接种肿瘤细胞后第3天给予环磷酰胺腹腔化疗。每日观察各组小鼠临床GVHD的指标,并给予临床评分。观察荷瘤鼠肿瘤生长情况,计算接种成功后首日到小鼠死亡的时间和肿瘤质量,计算抑瘤率。应用流式细胞仪检测各组小鼠外周静脉血中T细胞数量,接种后15d各组处死3只小鼠取瘤体制作成观察切片,HE染色后光镜观察。多组比较采用方差分析,组间比较采用LSD—t检验。结果化疗＋DLI组的小鼠GVHD临床表现轻于其他组小鼠。对照组、化疗组、DLI组、化疗＋DLI组GVHD评分分别为（2．3±0．6）分、（1．5±1．1）分、（6．7±0．9）分、（3．4±0．5）分,4组比较,差异有统计学意义（F=148．68,P〈0．05）。4组小鼠全部接种CT26细胞成功。对照组、化疗组、DLI组、化疗＋DLI组小鼠肿瘤质量分别为（3．40±0．20）g、（0．80±0．10）g、（2．20±0．20）g、（0．50±0．30）g,4组比较,差异有统计学意义（F=149．17,P〈0．05）;4组小鼠抑瘤率分别为0、77％±9％、35％±3％、85％±44％;4组小鼠CD3’分别为52．3％±2．9％、44．8％±3．1％、62．9％±3．5％、65．9％±3．3％,4组比较,差异有统计学意义（F：28．04,P〈0．05）;4组小鼠CD3＋CD4＋分别为32．1％±2．6％、27．1％±1．1％、42．6％±1．8％、41．7％±2．4％,4组比较,差异有统计学意义（F=40．29,P〈0．05）;4组小鼠CD3＋CD8＋分别为22．7％±2．2％、20．7％±1．8％、26．7％±0．8％、26．1％±0．7％,4组比较,差异有统计学意义（F=10．74,P〈0．05）;4组小鼠CD3＋CD＋CD25＋分别为8．7％±0．6％、6．6％±0．6％、11．2％±0．4％、13．3％±0．7％,4组比较,差异有统计学意义（F=82．88,P〈0．05）。4组小鼠的肿瘤组织均有不同程度的坏死、出血,其中DLI组和化疗＋DLI组肿瘤组织大片坏死,瘤细胞变小,间质内有大量炎性细胞浸润,化疗＋DLI组还可见大量增生的淋巴滤泡。对照组、化疗组、DLI组、化疗＋DLI组小鼠生存时间分别为（16．8±2．5）d、（26．3±2．9）d、（23．4±2．5）d、（33．7±4．6）d,4组比较,差异有统计学意义（F=46．45,P〈0．05）。结论（1）预处理方案可以诱导小鼠的特异性免疫耐受。（2）单倍体异基因淋巴细胞输注与化疗具有协同作用,联合应用可以抑制小鼠皮下移植瘤瘤体的生长以及延长小鼠的生存时间。（3）化疗可降低供体淋巴细胞输注后诱发的GVHD效应并且提高了GVT效果。（4）CD3＋CIN＋CD25＋T淋巴细胞在降低GVHD反应中起着重要的作用。     

应用酵母双杂交技术筛选和验证与DNA-PKcs磷酸化簇区域相互作用的蛋白

目的 通过酵母双杂交技术筛选与DNA依赖蛋白激酶的催化亚单位（DNA dependent protein kinase catalytic subunit,DNA-PKcs）磷酸化簇区域相互作用的蛋白并进行验证。方法 通过酵母双杂交技术,以之前构建的pGBKT7-DPC载体为诱饵,在人肝组织酵母文库中筛选与DNA-PKcs磷酸化簇区域相互作用的蛋白,对筛选出来的阳性酵母细胞克隆进行PCR鉴定、回转验证以及测序分析;构建诱饵蛋白和阳性克隆蛋白的真核表达载体,分别转染至人胚肾293T细胞中,检测诱饵蛋白和阳性克隆蛋白能否正确表达;最后将阳性克隆蛋白与诱饵蛋白共转染至293T细胞中,通过免疫共沉淀实验检测阳性克隆蛋白与诱饵蛋白之间的相互作用。结果 经过两轮酵母双杂交实验筛选得到12个文库质粒克隆,通过PCR鉴定确定7个插入片段长度互不相同的文库克隆,对7个文库克隆进行回转验证得到3个与DNA-PKcs磷酸化簇区域相互作用的蛋白,经测序分析显示分别为MBNL1、SIK2和YY1AP1。成功构建诱饵蛋白和3个阳性克隆蛋白的真核表达载体,且均能够在293T细胞中正确表达。免疫共沉淀实验证实筛选出来的3个阳性克隆蛋白均能够与DNA-PKcs磷酸化簇区域发生相互作用。结论 成功筛选到与DNA-PKcs磷酸化簇区域相互作用的蛋白并进行了验证。     

脑静脉血栓病人的死亡因素分析(附5例分析)

目的分析脑静脉血栓(CVT)病人的死亡原因。方法回顾分析136例CVT病人中5例死亡病例的病因、临床表现、影像学资料、治疗经过及死亡原因。结果病死率为3.7%。2例在急性期死亡,3例在慢性期死亡。直接死亡因素均为脑疝;间接死亡因素为颅内多发性出血和多个部位的脑静脉血栓形成,死亡组(3.20±0.84)支静脉受累,存活组(2.09±1.00)支静脉受累(P=0.016)。而性别、年龄、确诊时间、癫疒间发作、病灶部位及治疗前颅内压等没有显著增加死亡的危险性。某些临床表现,如失语、运动障碍、精神症状及意识障碍与死亡有关,但其系多发性颅内出血及多个部位脑静脉血栓所致。结论CVT病人的直接死亡原因为脑疝,间接原因为多发性脑静脉血栓和颅内多发性出血。死亡不仅可以发生在急性期,也可以出现在慢性期。     

Viscoelasticity of repaired sciatic nerve by poly（lactic-co-glycolic acid） tubes

Medical-grade synthetic poly（lactic-co-glycolic acid） polymer can be used as a biomaterial for nerve repair because of its good biocompatibility, biodegradability and adjustable degradation rate. The stress relaxation and creep properties of peripheral nerve can be greatly improved by repair with poly（lactic-co-glycolic acid） tubes. ＂Fen sciatic nerve specimens were harvested from fresh corpses within 24 hours of death, and were prepared into sciatic nerve injury models by creating a 10 mm defect in each specimen. Defects were repaired by anastomosis with nerve autografts and poly（lactic-co-glycolic acid） tubes. Stress relaxation and creep testing showed that at 7 200 seconds the sciatic nerve anastomosed by poly（lactic-co-glycolic acid） tubes exhibited a greater decrease in stress and increase in strain than those anastomosed by nerve autografts. These findings suggest that poly（lactic-co-glycolic acid） exhibits good viscoelasticity to meet the biomechanical require- ments for a biomaterial used to repair sciatic nerve injury.     

毛蕊异黄酮介导GP130/JAK/STAT信号通路对脊髓星形胶质细胞氧化损伤的影响

目的 探究毛蕊异黄酮介导糖蛋白130（GP130）/Janus酪氨酸蛋白激酶（JAK）/信号转导及转录激活因子（STAT）信号通路对脊髓星形胶质细胞氧化损伤的影响。方法 原代分离大鼠脊髓星形胶质细胞,并利用免疫荧光检测胶质纤维酸性蛋白（GFAP）进行鉴定。分别加入5、10、20 μmol·L^-1毛蕊异黄酮预处理脊髓星形胶质细胞12 h,然后加入100 μmol·L^-1过氧化氢（H₂O₂）处理24 h造成氧化损伤模型,细胞增殖与活性检测（CCK-8）法检测各组细胞增殖情况选择合适的毛蕊异黄酮处理浓度。实验分为空白组、模型组（H₂O₂ 100 μmol·L^-1）、毛蕊异黄酮组（毛蕊异黄酮 20 μmol·L^-1）、毛蕊异黄酮+LY294002组（毛蕊异黄酮 20 μmol·L^-1+LY294002 10 μmol·L^-1）、毛蕊异黄酮+Stattic组（毛蕊异黄酮 20 μmol·L^-1+Stattic 3 μmol·L^-1）。CCK-8法、免疫荧光检测各组细胞增殖情况,流式细胞术检测各组细胞凋亡和周期情况;蛋白免疫印迹法（Western blot）检测各组细胞中磷酸化（p）-JAK2、p-STAT3、p-蛋白激酶B（Akt）、GP130、白细胞介素-6（IL-6）的蛋白表达水平。结果 与空白组比较,模型组细胞的增殖活力明显降低,细胞凋亡率明显升高（P<0.05）;与模型组比较,毛蕊异黄酮（20 μmol·L^-1）组细胞的增殖活力明显增加,细胞凋亡率明显降低（P<0.05）;与毛蕊异黄酮（20 μmol·L^-1）组比较,PI3K抑制剂LY294002和STAT3抑制剂Stattic均能明显降低细胞的增殖活力,增加细胞凋亡率（P<0.05）。与空白组比较,模型组细胞中p-JAK2、p-STAT3、p-Akt、GP130、IL-6的蛋白表达水平明显增加（P<0.05）;与模型组比较,各用药组p-JAK2、p-STAT3、p-Akt、GP130、IL-6的蛋白表达水平均明显降低（P<0.05）。结论 毛蕊异黄酮能够促进氧化损伤的星形胶质细胞增殖并抑制其凋亡,并能通过抑制磷脂酰肌醇3-激酶（PI3K）/Akt通路磷酸化、JAK2/STAT3通路磷酸化起作用。     

Use of nerve conduits for peripheral nerve injury repair A Web of Science-based literature analysis

OBJECTIVE: To identify global research trends in the use of nerve conduits for peripheral nerve injury repair. DATA RETRIEVAL: Numerous basic and clinical studies on nerve conduits for peripheral nerve injury repair were performed between 2002-2011. We performed a bibliometric analysis of the institutions, authors, and hot topics in the field, from the Web of Science, using the key words peripheral nerve and conduit or tube. SELECTION CRITERIA: Inclusion criteria: peer-reviewed published articles on nerve conduits for peripheral nerve injury repair, indexed in the Web of Science; original research articles, reviews, meeting abstracts, proceedings papers, book chapters, editorial material, and news items. Exclusion criteria: articles requiring manual searching or telephone access; documents not published in the public domain; and several corrected papers. MAIN OUTCOME MEASURES: (a) Annual publication output; (b) publication type; (c) publication by research field; (d) publication by journal; (e) publication by funding agency; (f) publication by author; (g) publication by country and institution; (h) publications by institution in China; (i) most-cited papers. RESULTS: A total of 793 publications on the use of nerve conduits for peripheral nerve injury repair were retrieved from the Web of Science between 2002-2011. The number of publications gradually increased over the 10-year study period. Articles constituted the main type of publication. The most prolific journals were Biomaterials, Microsurgery, and Journal of Biomedical Materials Research Part A. The National Natural Science Foundation of China supported 27 papers, more than any other funding agency. Of the 793 publications, almost half came from American and Chinese authors and institutions. CONCLUSION: Nerve conduits have been studied extensively for peripheral nerve regeneration; however, many problems remain in this field, which are difficult for researchers to reach a consensus.     

Mechanosensitivity of voltage-gated K+ currents in rat trigeminal ganglion neurons

We investigated the mechanosensitivity of voltage-gated K+ channel (VGPC) currents by using whole-cell patch clamp recording in rat trigeminal ganglion (TG) neurons. On the basis of biophysical and pharmacological properties, two types of VGPC currents were isolated. One was transient (I(K,A)), the other sustained (I(K,V)). Hypotonic stimulation (200 mOsm) markedly increased both I(K,A) and I(K,V) without affecting their activation and inactivation kinetics. Gadolinium, a well-known blocker of mechanosensitive channels, failed to block the enhancement of I(K,A) and I(K,V) induced by hypotonic stimulation. During hypotonic stimulation, cytochalasin D, an actin-based cytoskeletal disruptor, further increased I(K,A) and I(K,V), whereas phalloidin, an actin-based cytoskeletal stabilizer, reduced I(K,A) and I(K,V). Confocal imaging with Texas red-phalloidin showed that actin-based cytoskeleton was disrupted by hypotonic stimulation, which was similar to the effect of cytochalasin D. Our results suggest that both I(K,A) and I(K,V) are mechanosensitive and that actin-based cytoskeleton is likely to regulate the mechanosensitivity of VGPC currents in TG neurons.     

踢伤至臀筋膜室综合征1例报告

骨筋膜室综合征是骨科创伤常见的并发症 ,如治疗不及时、处理不当会造成神经肌肉缺血变性、坏死甚至危急生命 ,给患者带来伤残和严重的后遗症。现将 1例踢伤致右侧臀筋膜室综合征的病例报道如下 :患儿 ,男 ,12岁 ,以踢伤右臀部伴右下肢活动障碍 10ｄ为主诉。患儿 10ｄ前被足踢伤右臀部 ,当时自觉疼痛 ,走路跛行 ,没有重视 ,也未作任何治疗。伤后 7ｄ ,又被踢伤右臀部 ,当时自觉疼难忍 ,逐渐发现右臀部肿胀加重、皮肤发亮 ,在当地县医院就诊住院对症治疗 ,未能缓解症状 ,故来我院就诊 ,门诊以右侧臀筋膜室综合征收住院。入院检查 :Ｔ 38 5℃…