仿生髓核组织工程材料支架对体外培养髓核细胞合成代谢的影响

目的：观察自行设计构建的仿生髓核组织工程材料——CⅡ／HyA-CS（CHCS）支架对体外培养髓核细胞合成代谢的影响。方法：将体外培养的传1代髓核细胞接种于培养瓶内，置入CHCS支架，体外培养10d后，分别测定^3H-脯氨酸掺入量、培养液中糖胺聚糖（GAG）含量、髓核细胞可凝集蛋白多糖（Aggrecan）、核多糖（Decorin）、二聚糖（Biglycan）的mRNA表达及Aggrecan的蛋白表达等。结果：实验组与对照组的^3H-脯氨酸掺入量、培养液中GAG含量、髓核细胞Aggrecan、Decorin、Biglycan mRNA表达、Aggrecan蛋白表达等均无统计学差异。结论：CHCS支架对体外培养髓核细胞的合成代谢无明显抑制作用。     

Nutrition entérale intermittente en réanimation

Intermittent enteral feeding is defined as the brief (20 to 60 minutes) and repeated (4 to 6 times daily) administration of enteral nutrition solution. This alternative, described as more physiological, seems to offer attractive benefits compared to the classic pattern of continuous administration, considered as a gold-standard in the ICU setting. Intermittent feeding seems to facilitate the achievement of daily energy targets and potentiate muscle anabolism in ICU patients, without increasing infectious complications or digestive side effects. No difference in terms of insulin consumption or glycemic variability has been reported in patients with intermittent enteral nutrition. Intermittent enteral nutrition may facilitate the accomplishment of mobilization sessions or physical exercise as part of an early functional rehabilitation strategy. Large randomized controlled trials are needed to incorporate this innovative technique into our daily clinical practice.     

Manipulation of the anabolic and catabolic responses with BMP-2 and zoledronic acid in a rat femoral fracture model

Bone repair involves a complex set of regulated signaling pathways that control the formation of new bone matrix and the resorption of damaged bone matrix at the fracture site. It has been reported that the optimal time point for single-dose zoledronic acid (ZA) administration systemically increased the strength of bone morphogenetic protein (BMP)-7-mediated callus. However, its repair mechanism during bone fracture healing remains unknown. We aimed to investigate the synergic effect of recombinant human (rh) BMP-2 and ZA in a rat femoral fracture model. Fifty-eight rats were divided into 4 groups. Group I (n = 14) animals were implanted with a carrier alone. Group II (n = 15) animals were implanted with a carrier containing 1-μg rhBMP-2. Group III (n = 14) animals were implanted with a carrier and a subcutaneous systemic ZA injection 2 weeks after surgery. Group IV (n = 15) animals were implanted with a carrier containing 1-μg rhBMP-2 and ZA subcutaneous injection 2 weeks after surgery. The rats were euthanized after 6 weeks and their fractured femurs were explanted and assessed by manual palpation, radiographs, and high-resolution micro-computerized tomography (micro-CT) and were subjected to biomechanical and histological analysis. The fusion rates in Group IV (93.3%) were considerably higher than those in Groups I (28.6%), II (53.3%), and III (57.1%). Additionally, the radiographic scores of Group IV were higher than those in Groups I, II, and III. In micro-CT analysis, the tissue volume (TV) of the callus was higher in Group IV than in Groups I and II (p < 0.05). New bone volume (BV) and trabecular spacing (Tb.Sp) also showed essentially the same trend as that of TV. The ratio of BV to TV (BV/TV), the trabecular number (Tb.N), and the trabecular thickness (Tb.Th) was higher in Groups III and IV than in Groups I and II (p < 0.05). In biomechanical analysis, the ultimate loads at failure and stiffness in Groups III and IV were on average higher than those in Groups I and II (p < 0.05), while the energy absorption of Group IV was higher than those of Groups I and II (p < 0.05). The synergic effect of rhBMP-2 and ZA given systemically as a single dose at the optimal time was efficacious for fracture repair and significantly enhanced bone fusion. Our results suggest that this combination facilitates bone healing and has potential clinical application.     

重组人生长激素在外伤性呼吸困难老年病人肠内营养中的应用

目的:研究重组人生长激素(rhGH)对胸部外伤限制性呼吸困难老年病人的应用.方法:选择多发性肋骨骨折(＞3根)病人16例,年龄均＞70岁,随机分为两组,每组8例.治疗组采用肠内营养 GH,其中GH每天12U,共计8天.对照组仅采用肠内营养.治疗前和治疗后第8天,分别测定血清清蛋白、转铁蛋白、前清蛋白浓度和双手握力试验,观察坠积性肺炎的发生情况.结果:治疗组病人第8天的血清清蛋白、转铁蛋白和前清蛋白水平比对照组明显升高(P＜0.01),双手握力试验较治疗前明显提高(P＜0.01);治疗组病人坠积性肺炎的发生率较对照组明显降低(P＜0.05).结论:rhGH 肠内营养支持可以明显改善老年病人蛋白质合成代谢,增加肌肉的收缩力,增强排痰力度,减少了坠积性肺炎的发生率.     

生长激素联用低热量肠外营养对多器官衰竭患者蛋白质代谢的影响

危重症患者，机体常处于一种营养摄取不足，合成障碍的状态。近年来对危重患者尤其是多器官衰竭患者的营养支持越来越受到重视，随着对危重患者代谢特点的认识，发现单纯营养支持及过高热氮量营养支持不仅不能迅速纠正负氮平衡，改善低蛋白血症。而且给多器官带来额外负担甚至营养并发症。有研究显示，适量的热氮供应并联合代谢调理措施才能使营养支持更为接近患者的病理生理改变的实际需要才能达到营养支持治疗目的，改善患者预后。     

Role of nutrients in the regulation of in vivo protein metabolism in humans

Nutrients regulate protein metabolism both in an acute fashion and on a long-term basis. The ingestion of meals is associated with a dramatic switch from an overall catabolic state to a state of net protein anabolism. The acute response of protein metabolism to meal ingestion is mediated, in part, by an increase in insulin secretion, itself a consequence of glucose absorption. Whereas insulin may primarily suppress rates of proteolysis, amino acids are responsible for the stimulation of protein synthesis that follows food intake. In the long run, the effects of nutrition on protein metabolism depend on the energy supply, the source of the energy (carbohydrate versus fat) and dietary protein intake. Finally, specific amino acids, such as glutamine, may play an additional role as protein anabolic agents.     

GABA_A受体调控途径及相关神经精神类疾病用药进展

GABAA受体是神经系统重要的抑制性受体,涉及抑郁、焦虑、癫痫、记忆障碍、药物依赖等多种神经精神类疾病的发病机制和诊断医疗,近年来有关该受体对人体镇静、镇痛、肌松等的研究逐步深化。现从GABAA受体亚基与结合位点的关联性,GABAA合成、转运、代谢的影响因素以及GABAA与HPA轴的反向调节等方面简述GABAA受体调控机制和介导的相关疾病研究情况。