Insulin, insulin-like growth factors and incretins: neural homeostatic regulators and treatment opportunities

Mood disorders may be conceptualized as progressive neurodegenerative disorders associated with cognitive decline. Novel treatments capable of preserving and/or enhancing cognitive function represent an area of priority for research in the future. Insulin, insulin-like growth factor (IGF)-1 and incretins may play a critical role in both physiological and pathophysiological processes of the CNS. An emerging paradigm regarding the pathophysiology of mood disorders posits that alterations in biological networks that mediate stress compromise optimal neuronal and glial function. A growing body of evidence indicates that central administration of insulin may enhance cognitive function in both healthy and cognitively impaired individuals. The neuroactive peptides, insulin, IGF-1 and incretins, or agents that facilitate their central effects (e.g. insulin-sensitizing agents), may constitute novel and possibly disease-modifying neurocognitive treatments.     

Autophagy contributes to BMP type 2 receptor degradation and development of pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is characterised by an increase in mean pulmonary arterial pressure which almost invariably leads to right heart failure and premature death. More than 70% of familial PAH and 20% of idiopathic PAH patients carry heterozygous mutations in the bone morphogenetic protein (BMP) type 2 receptor (BMPR2). However, the incomplete penetrance of BMPR2 mutations suggests that other genetic and environmental factors contribute to the disease. In the current study, we investigate the contribution of autophagy in the degradation of BMPR2 in pulmonary vascular cells. We demonstrate that endogenous BMPR2 is degraded through the lysosome in primary human pulmonary artery endothelial (PAECs) and smooth muscle cells (PASMCs): two cell types that play a key role in the pathology of the disease. By means of an elegant HaloTag system, we show that a block in lysosomal degradation leads to increased levels of BMPR2 at the plasma membrane. In addition, pharmacological or genetic manipulations of autophagy allow us to conclude that autophagy activation contributes to BMPR2 degradation. It has to be further investigated whether the role of autophagy in the degradation of BMPR2 is direct or through the modulation of the endocytic pathway. Interestingly, using an iPSC-derived endothelial cell model, our findings indicate that BMPR2 heterozygosity alone is sufficient to cause an increased autophagic flux. Besides BMPR2 heterozygosity, pro-inflammatory cytokines also contribute to an augmented autophagy in lung vascular cells. Furthermore, we demonstrate an increase in microtubule-associated protein 1 light chain 3 beta (MAP1LC3B) levels in lung sections from PAH induced in rats. Accordingly, pulmonary microvascular endothelial cells (MVECs) from end-stage idiopathic PAH patients present an elevated autophagic flux. Our findings support a model in which an increased autophagic flux in PAH patients contributes to a greater decrease in BMPR2 levels. Altogether, this study sheds light on the basic mechanisms of BMPR2 degradation and highlights a crucial role for autophagy in PAH. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.     

生物黏附材料壳聚糖的黏附性能

目的:考察壳聚糖与黏蛋白的相互作用,评价壳聚糖黏附性能的影响因素。方法:于2006-07/12在中国科学院大连化学物理研究所生物医用材料工程实验室完成。将壳聚糖溶液与黏蛋白溶液混合,用紫外分光光度计测定溶液混合前后紫外吸收值的变化,表征壳聚糖的黏附性能。①调节反应溶液的pH值(1.0,3.0,5.0),考察环境pH对壳聚糖黏附性能的影响。②改变反应温度(4,25,37℃),考察环境温度对壳聚糖黏附性能的影响。③选择不同相对分子质量(48000,124000,230000)的壳聚糖,考察壳聚糖相对分子质量对其黏附性能的影响。④选择不同脱乙酰度(56%,67%,97%)的壳聚糖,考察壳聚糖脱乙酰度对其黏附性能的影响。⑤使用不同种类(I-S型及Ⅲ型)黏蛋白,考察黏蛋白中唾液酸含量对壳聚糖黏附性能的影响。结果:①环境介质pH由1.2升至5.0时,壳聚糖黏附性能随之显著升高。②壳聚糖黏附性能随着温度的升高而显著增强。③壳聚糖相对分子质量对于壳聚糖黏附无显著影响。④壳聚糖脱乙酰度增加,其黏附性能显著增强。⑤I-S型黏蛋白与壳聚糖的作用较之Ⅲ型黏蛋白与壳聚糖的相互作用明显增强。结论:壳聚糖的黏附受环境pH、温度、壳聚糖及黏蛋白两种分子电荷密度的显著影响;在酸性环境下增大环境pH值、升高环境温度、增加壳聚糖的脱乙酰度和增加黏蛋白中唾液酸的含量,均有利于壳聚糖的黏附。     

阻断局部肾素-血管紧张素-醛固酮系统不同环节对大鼠肺间质纤维化肿瘤坏死因子α表达的影响

目的:观察阻断肾素-血管紧张素-醛固酮系统不同环节对实验性肺纤维化大鼠肺组织肿瘤坏死因子α的影响。方法:实验于2005-08/2006-08在南华大学附属第一医院临床研究所及南华大学医学院组胚、生理实验室完成。取6周龄SD大鼠50只,随机分为正常对照组、模型组、卡托普利组、螺内酯组和氯沙坦组,每组10只。正常对照组气管内注入生理盐水,其他40只SD大鼠气管内注入博莱霉素5mg/kg复制肺纤维化模型。次日胃管内灌注血管紧张素转换酶抑制剂卡托普利60mg/kg(卡托普利组)、血管紧张素Ⅱ的Ⅰ型受体阻断剂氯沙坦10mg/kg(氯沙坦组)、醛固酮受体拮抗剂螺内酯100mg/kg(螺内酯组)、等量生理盐水(模型组和正常对照组),1次/d。各组动物均于给药后第28天处死,通过苏木精-伊红染色和Mallory染色观察肺组织病理变化,用免疫组织化学法和图像分析系统定量检测肺组织肿瘤坏死因子α的表达。结果:41只大鼠进入结果分析。①肿瘤坏死因子α蛋白表达:模型组高于正常对照组(166.82±4.14,61.44±1.94,P<0.01),卡托普利组、氯沙坦组、螺内酯组低于模型组(107.50±4.60,113.64±8.47,118.00±7.14,P<0.01),各用药组间无差异。②模型组肺泡炎程度、肺纤维化程度显著高于正常对照组(P<0.01,0.05),卡托普利组、氯沙坦组、螺内酯组较模型组好转(P<0.01),各用药组间无差异。结论:肺局部肾素-血管紧张素-醛固酮不同环节可能通过刺激肺部肿瘤坏死因子α表达而发挥致纤维化作用,阻断其不同环节可阻止肿瘤坏死因子α水平升高,抑制肺纤维化形成。     

Granulocyte-macrophage colony-stimulating factor and interleukin-3 mRNAs are produced by a small fraction of blood mononuclear cells

Northern blot analysis has identified granulocyte macrophage colony stimulating factor (GM-CSF) mRNA in monocytes and both GM-CSF and interleukin-3 (IL-3) mRNA in lymphocytes. However, these results have not addressed whether all cells or a subset of the population is capable of hematopoietic growth factor (HGF) production. To resolve this question, we applied in situ hybridization of radiolabeled antisense RNA probes to centrifuged preparations of total blood mononuclear cells (BMCs) and fractionated lymphocyte subpopulations. Without stimulation, no circulating cells expressed detectable levels of GM-CSF or IL-3 mRNA. On stimulation of BMCs with phorbol myristate acetate (PMA) and phytohemagglutinin or PMA and the calcium ionophore ionomycin, approximately 5% expressed GM-CSF mRNA and approximately 1% IL-3 mRNA. Control sense probes produced no labeled cells. To determine the subsets of lymphocytes capable of GM-CSF and IL-3 expression, BMCs were fractionated by FACS into CD8+ and CD4+ lymphocyte subsets and CD16+ (NK) cells. The unfractionated cells and cell fractions were then stimulated with PMA and ionomycin. Results demonstrated that 3% to 5% of the CD16+, CD8+, and CD4+ lymphocytes produced GM-CSF mRNA. However, the number of IL-3 mRNA-positive cells in the FACS-sorted subsets was greatly reduced (0.02% to 0.05%) as compared with the unseparated cells (1%). Treatment of BMCs with high-dose interleukin-2 (IL-2) for 1 week followed by PMA plus ionomycin resulted in a lymphocyte population in which 50% and 3% of cells expressed GM-CSF and IL-3 mRNA, respectively. Thus, GM-CSF and IL-3 mRNA expression in T cells and NK cells is restricted to a small fraction of cells that can be greatly expanded by IL-2 stimulation. These results suggest a possible physiologic mechanism for increasing HGF production by circulating lymphocytes.     

不同浓度一氧化碳对大鼠脂质过氧化及谷胱甘肽过氧化物酶的影响

不同浓度一氧化碳对大鼠脂质过氧化及各胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）的影响研究结果表明：大鼠在５００ｍｇ／ｍ３ＣＯ染毒下，第２０天血液中的脂质过氧化物及第３０天心脏组织的脂质过氧化物均明显升高，而５０、２５ｍｇ／ｍ３ＣＯ染毒则未见上述变化。但自２５ｍｇ／ｍ３浓度开始，ＧＳＨ－Ｐｘ活性即发生明显变化。提示ＣＯ能诱发自由基导致脂质过氧化；也说明ＧＳＨ－Ｐｘ是ＣＯ对机体影响的早期敏感指标之一。本研究可为室内ＣＯ卫生标准的制订提供部分新的资料。     

Enterobacter cloacae causing pneumatocele in a neonate

Pneumatocele formation, a cyst-like rarefaction that develops within the lung parenchyma, is an unusual complication of pneumonia in the neonate. It has been reported to occur with Staphlococcus aureus, Escherichia coli, Klebsiella pneumoniae, Streptococcus pneumoniae , and Pseudomonas aeruginosa infections. We describe a case of a premature neonate with pneumonia and subsequent pneumatocele formation caused by Enterobacter cloacae     

硫酸镁治疗妊娠高血压综合征的群体药动学—药效学

用 NONMEM 程序分析硫酸镁治疗妊娠高血压综合征患者的群体药动学-药效学,以快—慢速率相继静脉输注二室开放模型拟合60例患者的群体药动学参数,以效应室与中央室连接的三室模型,用参数法拟合26例患者的Sigmoid E_max药效学模型的群体参数。采用分光光度法测定血镁浓度(以给药前的基础值作调整),选择舒张压降低的百分率为药效指标。硫酸镁的群体药动学参数为:群体典型值K₁₀(h^-1),K₁₂(h^-1),K₂₁(h^-1)和Vc(L)分别等于1.62,20.8,2.70,27.0,其个体间变异σ_K10(%),σ_K12(%),σ_K21(%),σ_Vc(%)分别等于25.70,14.13,24.33,34.04,浓度的残差变异σ_E(%)等于15.03。硫酸镁的群体药效学参数为:群体典型值E_max(%),C_e(50)(μg·ml^-1),υ,K_eo(h^-1)分别等于28.73,28.39,4.22,0.43。其个体间变异σ_Emax(%),σ_Ce(50)(%),σ_υ(%),σ_Keo(%)分别等于56.32,62.24,33.47,42.76。效应的残差变异σ'_E(%)等于28.54。     

HM-PAO非对映立体异构体的核磁共振鉴定及立体异构纯度的测定

本文报道外消旋和内消旋六甲基丙二胺肟(HM-PAO)在一些常见溶剂中的¹H和¹³C化学位移。利用它们的¹³CNMR谱或氯仿中的¹HNMR谱,可以方便地鉴定这两个性质非常近似的非对映立体异构体。研究结果还表明,利用常规的全去偶¹³CNMR谱可以测定外消旋体在这两种异构体混合物中的立体异构纯度。