Enhanced osteointegration on tantalum-implanted polyetheretherketone surface with bone-like elastic modulus

Polyetheretherketone (PEEK) possesses a similar elastic modulus as bones but yet suffers from bio-inertness and poor osteogenesis. In this work, tantalum ions are implanted energetically into PEEK by plasma immersion ion implantation (PIII) to form Ta₂O₅ nanoparticles in the near surface. Nanoindentation reveals that the surface elastic modulus of the Ta ion implanted PEEK is closer to that of human cortical bones. In vitro cell adhesion, alkaline phosphatase activity, collagen secretion, extracellular matrix mineralization, and real-time PCR analyses disclose enhanced adhesion, proliferation, and osteogenic differentiation of rat bone mesenchymal stem cells (bMSCs) on the Ta-PIII modified PEEK. In vivo evaluation of the cortico-cancellous rat femur model by means of micro-CT, sequential fluorescent labeling, and histological analysis after 8 weeks confirms significantly improved osteointegration. The bone-like elastic modulus and modified surface topography of the Ta-PIII modified PEEK synergistically induce osteogenic differentiation of bMSCs and the surface-modified materials have large potential in dental and orthopedic implants.     

冷水束缚应激对大鼠脊髓背根神经节、胃组织内TRPV1 mRNA 及血清 SOD、MDA 的影响

目的：探讨不同时间的冷水束缚应激（ WIRS）对大鼠脊髓背根神经节（ DRG）和胃内瞬时受体电位香草酸亚型1（TRPV1） mRNA及血清超氧化物歧化酶（SOD）、丙二醛（MDA）的影响。方法选取40只雄性Wistar大鼠,随机分成4组：正常组（NC组,n＝10）、WIRS 2 h组（n＝10）、WIRS 4 h组（n＝10）和WIRS 6 h组（n＝10）,NC组不造模;WIRS 2 h组、WIRS 4 h组、WIRS 6 h组均用WIRS法复制急性胃黏膜病变模型,大鼠WIRS时间分别为2、4、6 h。于不同作用时间观察大体胃黏膜损伤变化,评定胃黏膜损伤指数;HE染色观察胃黏膜的损伤程度;实时荧光定量PCR法检测各组大鼠胸段DRG和胃内的TRPV1 mRNA的表达情况;测定各组大鼠血清中SOD、MDA的活力。结果 WIRS各组大鼠胃黏膜损伤明显,溃疡指数明显升高（ P＜0.05）。与NC组比较,WIRS各组胃组织内TRPV1 mRNA的表达均降低（ P＜0.05）;胸段DRG内TRPV1 mRNA在WIRS 6 h组的表达明显降低（ P＜0.05）。血清SOD活力先增高后降低,4 h时达到高峰;MDA随应激时间延长呈增高趋势,但在应激4 h时出现一下降过程。结论 TRPV1参与了急性胃黏膜病变的发生机制;血清中SOD、MDA的活力变化较好地反映出应激时机体氧化和抗氧化能力,有望在发现和评估应激性溃疡的发生中起重要作用。     

谷氨酰胺对腹部开放伤合并海水浸泡犬肠功能的影响研究

目的 探讨谷氨酰胺对腹部开放伤后海水浸泡实验犬肠功能的影响.方法 30只成年犬致腹部开放伤,按数字表法随机分为海水浸泡组(对照组)、普通治疗组(常规组)和谷氨酰胺治疗组(观察组),每组10只.于致伤前及致伤后定时测定犬的血压、心率、呼吸、腹围、肠鸣音,取血测定内毒素、D-乳酸、双胺氧化酶(DAO)、肿瘤坏死因子-α(TNF-α)、白细胞介素-1(IL-1)和尿乳果糖/甘露醇(L/M),24 h后取小肠组织进行病理检查并测量肠黏膜厚度和绒毛高度.结果 与常规组比较,观察组平均动脉压、心率、呼吸、肠鸣音和腹围差异均无统计学意义(P＞0.05),对照组与常规组、观察组比较,平均动脉压、肠鸣音差异均有统计学意义(P＜0.05),致伤后12h和24 h时间点心率差异均有统计学意义(P＜0.05),致伤后24h时间点呼吸差异有统计学意义(P＜0.05),致伤后24h时间点腹围差异有统计学意义(P＜0.05).内毒素:对照组与常规组、观察组比较,致伤后12 h和24 h时间点差异均有统计学意义(P＜0.05),观察组与对照组、常规组比较,在24h时间点差异均有统计学意义(P＜0.05).D-乳酸:致伤后12 h时间点,常规组与对照组、观察组差异均有统计学意义(P＜0.05),观察组和对照组之间差异无统计学意义(P＞0.05);致伤后24 h时间点,常规组与对照组、观察组差异均有统计学意义(P＜0.05),观察组和对照组之间差异无统计学意义(P＞0.05).DAO:观察组与对照组、常规组比较,致伤后8h与24 h时间点差异均有统计学意义(P＜0.05).TNF-α:观察组与对照组、常规组比较,致伤后12 h与24 h时间点差异均有统计学意义(P＜0.05).IL-1:致伤后12 h时间点,常规组[(8.71±3.13)ng/L]与对照组[(7.40±2.71)ng/L]、观察组[(6.34±1.83)ng/L]差异均有统计学差异(P＜0.05),观察组和对照组差异无统计学意义(P＞0.05);致伤后24 h时间点,观察组[(7.44±3.11)ng/L]与对照组[(9.91±3.18)ng/L]、常规组[(10.12±2.25)ng/L]差异均有统计学意义(P＜0.05).尿L/M值:观察组(0.10±0.06)与对照组(1.07±0.04)、常规组(1.09±0.09)差异有统计学意义(P＜0.05).病理结果:观察组光镜下肠黏膜可见轻度水肿,与常规组、对照组比较明显减轻;观察组小肠黏膜厚度和绒毛高度与常规组比较差异均有统计学意义(P＜0.05);对照组与常规组比较差异均无统计学意义(P＞0.05).结论 谷氨酰胺对腹部外伤后海水浸泡导致的肠功能损伤有明确的治疗作用.     

常见热射病快速降温技术的对比评估

热射病是一种以严重高热(>40℃)和器官功能障碍为特征的紧急疾病,存在发病快、病死率高等特点。快速降温是治疗热射病的首要目标。本综述总结了目前比较常见且应用较广的快速降温技术,并根据现有研究成果对这些技术做了比较评估,以帮助医护人员在特定情况下选择最佳方案对热射病患者进行降温处理。水浸技术(1~17℃)可有效降低患者的核心体温,是目前对热射病降温最有效的降温手段。     

When Two Worlds Meet

ABSTRACT

The author is one of four American premedical students traveled to India to spend a month with Pallium India (palliumindia.org) to learn about palliative care at Trivandrum Institute of Palliative Sciences, in the south Indian state of Kerala. The program was arranged by Child Family Health International (cfhi.org). They attended classroom sessions and joined the palliative care team during home visits and hospital consultations. They learned not just what palliative care is, but also how to understand and adapt to another culture. It was shocking to learn that all health care expenses are often out-of-pocket for most of the developing world and to see the extent of the suffering involved in life-limiting diseases. The students saw how the medical professional could adopt a basic and simple approach to medicine, acting as a mix of scientist, humanist, and spiritualist. She concludes that we in the United States too seem to be learning the value of such an approach and to make better use of available resources to improve the quality of life of those who are suffering.     

锦州近海海域放射性活度及海生物所致居民的内剂量

本文报道了1988年～1989年锦州近海的海水、海底质和海生物中总α总β, ⁹⁰Sr、¹³⁷Cs, ^6Oco, ¹⁰⁶Ru、²³²Th、²²⁶Ra的放射性活度。在海水和海生物中⁹⁰Sr、¹³⁷Cs稍有增加, 说明海洋环境可能受到了切尔诺贝利事故泄漏物的污染。     

大鼠腹腔海水浸泡时间与死亡率的关系

目的 观察海水浸泡大鼠腹腔对大鼠急性死亡的影响,分析浸泡时间与死亡率的关系。方法:选取SD大鼠40只,随机分为对照组(等渗盐水腹腔浸泡组)及海水腹腔浸泡组,每组20只,观察腹腔浸泡后大鼠急性死亡情况。结果:对照组持续浸泡2小时均无死亡,海水腹腔浸泡组持续浸泡67min50％大鼠急性死亡,浸泡95min全部急性死亡。结论:海水腹腔浸泡可以引起大鼠急性死亡,死亡率随着海水浸泡时间的延长而增高。