Interaction between endogenous nitric oxide and carbon monoxide in the pathogenesis of hypoxic pulmonary hypertension

Hypoxic pulmonary hypertension, an important pathophysiological process in the development of a vari-ety of clinical cardiac and pulmonary diseases, has critical influence on the proceeding and prognosis of the dis- eases[1]. It is important to clarify the pathogenesis of the diseases. The discoveries of endogenous gas signal mole-cules, nitric oxide (NO) and carbon monoxide (CO), have been moving the research of hypoxic pulmonary hyper-tension to a very new phase. Our foregoing experiments …     

柴达木盆地野生大肥菇资源调查及人工驯化的研究

本文对青海省柴达木盆地野生大肥菇的形态、分类地位、分布、生境进行了研究，对大肥菇的人工驯化工作进行了探讨     

甘氨双唑钠对鼻咽癌移植瘤的时辰放射增敏作用

目的 观察甘氨双唑钠（CMNa）联合时辰放疗对鼻咽癌祼鼠移植瘤的时辰放射增敏作用,并探讨其作用机制.方法 将荷瘤裸鼠随机分为3组：放疗组、放疗＋CMNa组、空白对照组,每组分3HALO（光照后小时,hours after light onset）、9HALO、15HALO、21HALO四个时辰进行相应处理.测定肿瘤再生长延长时间（regrowth delay time,TGD）,绘制生长曲线.用免疫组化法检测各组肿瘤标本中HIF-1α、γ-H2AX和凋亡蛋白的表达.结果 通过对各组TGD的比较.以放疗＋CMNa组对肿瘤的抑制效果最好.在该组中,TGD：15HALO＞21HALO＞9HALO＞3HALO,15HALO与3HALO的TGD比较有统计学意义 15HALO与3HALO的HIF-1α、γ-H2AX及凋亡蛋白的表达水平比较有统计学意义.结论 甘氨双唑钠联合时辰放疗对鼻咽癌裸鼠移植瘤有明显的时辰放射增敏作用,以15HALO放疗＋CMNa组对肿瘤的抑制效果最佳.其机制可能与HIF-1α的表达.DNA双链损伤,凋亡有关.     

肿瘤乏氧分子探针的研究进展

近年来,恶性肿瘤严重威胁大众生命健康,给我国社会和医疗带来了沉重的负担,其中乏氧已成为大多数实体瘤的关键特征之一,肿瘤乏氧的发展与其侵袭性和耐药性密切相关,研究其发生发展规律,对恶性肿瘤的早期诊断与筛查具有十分重要的意义。分子探针能对乏氧进行可视化检测,有望实现乏氧肿瘤的准确影像,已成为当前恶性肿瘤诊治的交叉学科前沿之一。本文基于不同生物标志物[硝基还原酶(Nitroreductase, NTR)、偶氮还原酶和氢醌还原酶(Quinone Oxidoreductase, hNQO1)]系统总结了国内外肿瘤乏氧分子探针的研究进展,重点讨论了乏氧分子探针的设计方法、检测机理、传感性能和生物应用,并对肿瘤乏氧分子探针的未来发展趋势进行了展望。     

实体瘤细胞中低氧诱导因子-1蛋白的活性调控

实体肿瘤内部广泛存在着缺氧现象, 缺氧与肿瘤的远处转移、不良预后以及放化疗的耐受性关系密切. 低氧诱导因子-1 (HIF-1)在细胞缺氧信号途径中处于核心位置, 它能增强细胞在缺氧环境下的生存能力, 促进血管的增生及肿瘤的恶性转化. HIF-1所起的核心作用使其成为治疗人类恶性肿瘤时一个非常好的靶点. HIF-1在体内的调控途径异常复杂, 主要有氧浓度、葡萄糖代谢途径、原癌基因和抑癌基因的突变、PI3K-MAPK-mTOR通路、自由基以及抗氧化剂等, 其中研究最透彻的是氧浓度的调节. 而近年来自由基、DNA的突变以及葡萄糖代谢的调节成为研究的热点. 本文将围绕近年来这几方面的研究进展进行一个综合的回顾, 这将有助于针对HIF-1这一重要靶点进行抗肿瘤药物的研究.     

低氧胁迫下锰对猕猴桃抗氧化系统的影响

 猕猴桃栽培中易遭受水涝胁迫,造成根际低氧,致使土壤中氧化还原电位和pH 值过低,Mn⁴⁺被还原成Mn²⁺,Mn²⁺大量积累,进而导致Mn²⁺毒害。为此,本文采用水培通氮气及不同浓度的锰二因素随机区组的方法,从低氧胁迫和锰对秦美及中华猕猴桃幼苗叶、根抗氧化系统的协同影响方面,研究猕猴桃幼苗体内保护酶对活性氧的清除影响机理。结果表明,低氧条件下,10 和200 μmol/L 锰处理时,随着锰浓度的提高,2 个猕猴桃品种叶、根内超氧化物歧化酶(SOD)、过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、抗坏血酸(AsA)活性增加,在清除活性氧方面发挥了重要作用。低氧条件下,10 和200μmol/L 锰处理时过氧化氢酶(CAT)活性明显降低。低氧条件下600 μmol/L 锰处理时,2 个猕猴桃品种叶、根内SOD、POD、CAT、APX、GR 和AsA 活性显著降低,过氧化氢(H₂O₂)和丙二醛(MDA)含量迅速增加,猕猴桃膜脂过氧化进一步加剧。这表明,高浓度的锰处理不但不能增强猕猴桃对低氧胁迫的抗性,反而会加重低氧对猕猴桃植株的伤害。两种猕猴桃各生理指标变化都表现为一定的相似性,但秦美猕猴桃低氧下对锰的抗性明显高于中华猕猴桃。     

糖氧剥夺对大鼠脂肪干细胞自噬和成脂的影响

目的 研究大鼠脂肪干细胞(adipose derived stem cells,ADSC)及糖氧剥夺下,细胞自噬和对诱导分化成脂的影响.方法 常规制备ADSC,设置对照组(G组)、少糖组(SG组)、缺氧组(G+CoCl2组)、缺氧少糖组(SG+CoCl2组)和自噬阳性对照组(EBSS组).设置不同培养时间,MTT检测各...     

Spatially defined oxygen gradients and vascular endothelial growth factor expression in an engineered 3D cell model

Tissue hypoxia results in rapid angiogenesis in vivo, triggered by angiogenic proteins, including vascular endothelial growth factor (VEGF). Current views of tissue viability are founded on whether ‘deeper-lying’ cells receive sufficient nutrients and oxygen for normal activity and ultimately survival. For intact tissues, levels of such essential nutrients are governed by micro-vascular perfusion. However, there have been few effective quantitatively defined 3D models, which enable testing of the interplay or interdependence of matrix and cell density, and path diffusion on oxygen consumption in vitro. As a result, concepts on cell vulnerability to low oxygen levels, together with the nature of cellular responses are ill defined. The present study has adapted a novel, optical fibre-based system for in situ, real-time oxygen monitoring within three-dimensionally-spiralled cellular collagen constructs, which were then unfurled to enable quantitative, spatial measurements of VEGF production in different parts of the same construct exposed to different oxygen levels. A VEGF response was elicited by cells exposed to low oxygen levels (20 mmHg), primarily within the construct core. Received 3 August 2007; received after revision 24 October 2007; accepted 29 October 2007 An erratum to this article is available at .     

Heparanase involvement in physiology and disease

Heparanase is an endoglycosidase that degrades heparan sulfate on the cell surface and extracellular matrix. The physiological functions of heparanase include heparan sulfate turnover, embryo development, hair growth, and wound healing. Heparanase is implicated in a variety of pathologies, such as tumor growth, angiogenesis, metastasis, inflammation, and glomerular diseases. Heparanase overexpression in a variety of malignant tumors suggests that it could be a target for anti-cancer therapy.     

急性低氧对鲫鱼幼鱼血液基础指标的影响

为考查急性低氧对鲫鱼(Carassius auratus L.)幼鱼血液基础指标的影响,将身体健康、体重为(267.26±13.93)g实验鱼12尾随机平均分为两组,对照组置于水温20℃、溶氧浓度为(7.5±0.5) mg· L-1的水环境中,处理组置于相同水温但溶氧浓度为(1.0±0.2) mg· L-1的低氧水环境...