七氟醚和缺氧预适应对乳鼠心肌细胞生存和凋亡的影响

目的 探讨七氟醚预处理和缺氧预处理诱导乳鼠心肌细胞产生预适应的差异。方法 第2代心肌细胞随机分为正常对照组（C组）、缺氧／复氧组（A／R组）、缺氧预适应组（IP组）和七氟醚组（S组），每组均缺氧2h，复氧48h。取复氧1h心肌细胞用电镜观察细胞超微结构变化；分别取复氧0、1、2、24、36和48h的细胞用MTT法测定细胞生存情况、流式细胞仪测定细胞凋亡率。结果 （1）S组和IP组细胞超微改变不明显，未见凋亡细胞；A／R组改变明显，可见凋亡细胞；（2）在各个时点，S组和IP组的细胞生存能力显著低于C组（P＜0．05），显著高于A／R组（P＜0．01），S组和IP组间无显著性差异（P＞0．05）；随着复氧时间的延长，S组和IP组的细胞生存能力有上升的趋势；（3）在各个时点，S组和IP组的细胞凋亡率显著高于C组（P＜0．01），显著低于A／R组（P＜0．01）；S组和IP组间的细胞凋亡率只是在复氧0h和1h处有显著性差异；随着复氧时间的延长，S组和IP组的细胞凋亡率有下降的趋势，A/R组的则逐渐升高；（4）S组和IP 中的细胞生存力和凋亡之间存在着负相关关系。结论 七氟醚预适应和缺氧预适应对缺氧／复氧损伤细胞可产生早期和延迟保护作用，且两者之间的作用相似，提示在体外实验中七氟醚预适应可取代缺氧预适应。     

Azoospermia and maturation arrest: malfunction of valves in erect poster of humans leads to hypoxia in sperm production site

Maturation arrest (MA) of spermatogenesis is diagnosed on histology as interruption of spermatogenesis before the final stage without impairment of Sertoli or Leydig cells. It is considered a condition of irreversible or absolute infertility. Varicocele, which represents impairment in the testicular venous drainage system, has been shown to be a bilateral disease. Malfunction of the valves increase the hydrostatic pressure in the testicular venous system that exceeds the pressure in the arterial system leading to hypoxia in the testicular microcirculation and in the seminiferous tubules, the sperm production site. Sperm production deteriorates, and ultimately progresses to azoospermia. Our prediction was that MA, if genetic factors are excluded, is the final stage of long standing hypoxia. This would indicate that MA is not always an independent disease entity, but may represent progressive process of deterioration of the testicular parenchyma beyond azoospermia. By histology and electron microscopy, our prediction confirmed, at least partially, that MA is associated with degenerative ischaemic changes in the seminiferous tubules. Adequate treatment of bilateral varicocele by microsurgery or super-selective sclerotherapy of the internal spermatic veins including associated network of venous bypasses, vertically oriented, may resume the flow of oxygenated blood. If irreversible damages did not occur and ischaemia is not too long standing, limited sperm production may be restored, at least partially.     

Hypoxia suppresses serum deprivation‐induced degradation of the nucleus pulposus cell extracellular matrix through the JNK and NF‐κB pathways

Intervertebral disc (IVD) degeneration is associated with the imbalance between anabolism and catabolism of the nucleus pulposus (NP) extracellular matrix (ECM). Serum deprivation (SD) has been reported to exacerbate IVD degeneration; however, the effect of SD on ECM metabolism is not fully understood. Hypoxia plays important roles in maintaining the physiological functions of IVD cells; however, whether hypoxia has any effect on NP ECM production under conditions of SD is still unclear. In the current study, we established an in vitro SD model by exposing NP cells to serum‐free medium. SD decreased the expression of aggrecan and collagen II, as well as the production of sulfated glycosaminoglycan (sGAG) in a time‐dependent manner. However, hypoxia abolished SD‐mediated down‐regulation of aggrecan and collagen II expression via JNK1/2 activation. Moreover, hypoxia abolished SD‐induced MMP‐3 and MMP‐13 expression by inhibiting NF‐κB activation, p65 translocation, and MMP‐3 and MMP‐13 promoter activity. These results indicated that, hypoxia maintained ECM production under conditions of SD. This effect was elicited in part through JNK1/2‐mediated up‐regulation of matrix gene expression and down‐regulation of MMP expression, through the inhibition of NF‐κB. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2059–2066, 2017.

     

缺氧早期大鼠心肌细胞微管损害的观察

目的 了解缺氧早期心肌细胞微管损害程度。方法将分离培养的Wistar大鼠心肌细胞分为正常组、缺氧组（建立缺氧细胞模型并设缺氧10、20、30、60min为观察时相点）。用激光共聚焦显微镜及扫描电镜观察2组细胞微管分布、形态变化，对微管蛋白荧光强度进行半定量分析．用蛋白质印迹法检测2组细胞游离d微管蛋白的表达。结果 与正常组比较，缺氧10min后，缺氧组细胞微管念珠状结构消失，但排列尚有规律、数量无明显减少；缺氧20min不仅念珠状结构消失，而且微管排列散乱，远离胞核区出现微管缺失；缺氧30、60min时微管发生扭曲、断裂，纹理紊乱，完全丧失规律性。缺氧组心肌细胞微管蛋白荧光强度较正常组下降，且随缺氧时间延长愈加明显；缺氧组心肌细胞内游离的α微管蛋白表达（缺氧10min为46644±145）高于正常组（13357±98），两组比较，差异有统计学意义（P〈0．01），随缺氧时间的延长此升高趋势愈加明显。结论在缺氧状态下，心肌细胞微管发生解聚时间较早，其结构和分布规律被破坏。微管解聚在缺氧所致心肌细胞早期病理损害中的作用值得深入研究。     

Androgen-insensitive prostate cancer cells transiently respond to castration treatment when growing in an androgen-dependent prostate environment

BACKGROUND: Castration-induced involution of the normal prostate is caused by primary effects in the prostate stroma and vasculature, but if this is the case also in tumors is unknown. METHODS: Androgen-independent AT-1 prostate tumor cells were therefore injected into the ventral prostate (VP) in Copenhagen rats. Seven days later when the growing tumor was surrounded by normal VP tissue the rats were castrated and the effect examined 3 and 7 days later. RESULTS: Castration reduced vascular density in the surrounding VP tissue and this was accompanied by tumor cell hypoxia, apoptosis, and temporarily retarded tumor growth. Castration-induced VP tissue regression occurred more rapidly in the contra-lateral than in the tumor-bearing lobe. CONCLUSIONS: Androgen-independent tumor cell respond to castration when growing in an androgen-dependent environment. The presence of a tumor influences the castration response in the surrounding normal tissue. The microenvironment determines how prostate epithelial cells respond to castration.     

间断低氧预适应对大鼠肝切除缺血再灌注肝脏中EPO的影响

目的 观察术前间歇性低氧预适应对大鼠70％肝切术后肝脏中促红细胞生成素（Erythropoietin,EPO）量的影响.方法 健康清洁级SD大鼠120只,简单随机分为3组：假手术组（Sham,S组）40只;单纯大部肝切除组40只（Major hepatectomy,MH组）,即在肝门阻断下切除肝脏的左叶和中叶,肝门阻断20 min;间断低氧预适应组40只（Intermittent hypoxia preconditioning,IHP组）,术前1周将大鼠置于氧气体积分数10％的低氧环境中,每天1次,每次60 min.1周后在肝门阻断下行肝切除术（同IR组）.各组分别于术后2、6、12、24、48、72、120、168 h进行取材检测,用全自动生化分析仪检测下腔静脉血清ALT、AST含量,电镜下观察残余肝细胞中线粒体及内质网等的变化,采用ELISA测定残肝组织中促红细胞生成素的量,并运用统计学的方法比较各组中的意义.结果 MH组、S组、IHP组3组实验组中术后大鼠残肝组织中EPO水平具有显著统计学差异（P＜0.05）,间断低氧预处理组残余肝脏中EPO含量明显高于单纯肝切除组.结论 间断性低氧预适应可以促进肝切除术后残余肝组织中EPO的表达.     

A practical approach to cerebral near‐infrared spectroscopy (NIRS) directed hemodynamic management in noncardiac pediatric anesthesia

Safeguarding cerebral function is of major importance during pediatric anesthesia. Premature, ex‐premature, and full‐term neonates can be vulnerable to physiological changes that occur during anesthesia and surgery. Data from studies performed during pediatric cardiac surgery and in neonatal/pediatric intensive care units have shown the benefits of near‐infrared spectroscopy (NIRS) monitoring of regional cerebral oxygenation (c‐rSO₂). However, NIRS monitoring is seldom used during noncardiac pediatric anesthesia. Despite compelling evidence that blood pressure does not reflect end‐organ perfusion, it is still regarded as the most important determinant of cerebral perfusion and the most relevant hemodynamic management target parameter by most (pediatric) anesthetists. The principle of NIRS monitoring is not self‐explanatory and sometimes seems even counterintuitive, which may explain why many anesthesiologists are reserved regarding its use. The first part of this paper is dedicated to a clinical introduction to NIRS monitoring. Despite scientific efforts, it has not yet been possible to define individual lower limit c‐rSO₂ values and it is unlikely this will succeed in the near future. Nonetheless, published treatment algorithms usually specify c‐rSO₂ values which may be associated with cerebral hypoxia. Our treatment guideline for maintaining sufficient cerebral oxygenation differs fundamentally from all previously published approaches. We define a baseline c‐rSO₂ value, registered in the awake child prior to anesthesia induction, as the lowest acceptable limit during anesthesia and surgery. The cerebral rSO₂ is the single target parameter, while blood pressure, heart rate, P_aCO₂, and SaO₂ are major parameters that determine the c‐rSO2. Cerebral NIRS monitoring, interpreted together with its continuously available contributing parameters, may help avoid potentially harmful episodes of cerebral desaturation in anesthetized pediatric patients.     

间歇性低氧干预提高心梗大鼠心功能和运动耐量

目的:观察4周间歇性低氧（IH）干预对心梗（MI）大鼠心功能及运动耐量的影响。方法:28只雄性SD大鼠随机分为4组:空白组（Sham）、空白低氧组（Sham-IH）、心梗组（MI）和心梗低氧组（MI-IH）。低氧组放入低氧仓（模拟海拔5 000 m,氧浓度13%）,每天4 h。对照组置于常氧环境中。干预4周后检测心肌AMPK表达,心梗面积比例,左心室射血分数和运动耐量。结果:同MI组比较,MI-IH组 （1） 心梗面积比例减少（P<0.001）;（2） 左心室射血分数增加（P<0.001）;（3） 运动耐量增加（P<0.001）;（4） AMPK表达增加（P<0.05）。结论:4周间歇性低氧干预能提高心功能和运动耐量,可能与心肌AMPK表达增加有关。     

儿茶酚雌激素介导慢性间歇低氧诱导OSAHS雌性大鼠遗尿模型的建立

目的：利用慢性间歇低氧（CIH）诱导建立阻塞性睡眠呼吸暂停低通气综合征（OSAHS）遗尿雌性大鼠模型,并探讨儿茶酚雌激素（CE）在CIH诱导的OSAHS遗尿中的作用。方法：选取6周龄SD雌性大鼠16只,随机分成CIH组和对照组,每组8只。实验组置于常压间歇低氧舱,对照组置于同等条件下的空气模拟对照舱,均放置4周。监测24 h进水及排尿量;测定血清中CE,儿茶酚胺类化合物如肾上腺素（Adr）、去甲肾上腺素（NA）和多巴胺（DA）含量及其儿茶酚氧位甲基转移酶（COMT）活性;测定排尿阈;留取膀胱行HE及Weigert染色,光镜下观察组织学变化。结果：CIH组大鼠氧舱外进水量及排尿量与对照组比,差异无统计学意义（P＞0.05）。但CIH组大鼠氧舱内排尿量明显增加,血清中CE、Adr、NA和DA含量明显增高,而COMT的活性明显降低,排尿阈明显降低,膀胱组织光镜下显示膀胱逼尿肌肌束排列紊乱、疏松,部分肌束断裂。结论：CIH可诱导雌性大鼠发生遗尿,伴有排尿量增多,排尿阈降低,血清中儿茶酚胺类化合物含量增高,而COMT的活性降低,与儿童OSAHS诱发遗尿的临床症状相似,提示通过CIH诱导建立OSAHS遗尿雌鼠模型基本可行。