Exercise training activates large-conductance calcium-activated K+ channels and enhances nitric oxide production in rat mesenteric artery and thoracic aorta

Exercise training has reversible beneficial effects on cardiovascular diseases, e.g. hypertension, which may result from a decrease in systemic vascular resistance. The purpose of this study was to investigate possible mechanisms associated with the changes in vascular reactivity in large and small arteries with vasoconstrictors and vasodilators in rats after exercise. Wistar-Kyoto rats were trained for 8 weeks (Ex group) on a treadmill and compared with sedentary counterparts (Sed group). After the measurement of blood pressure and heart rate at 8 weeks, rat mesenteric arteries and thoracic aortas were excised and prepared as rings for this study. In addition, special care was taken not to damage the endothelium of the preparations. Our results showed that exercise training for 8 weeks (1) not only prevented an increase in blood pressure but also caused a fall in heart rate, (2) attenuated the contractions induced by both prostaglandin F(2alpha) (PGF(2alpha)) and high K(+) in the mesenteric artery, but reduced the PGF(2alpha)-induced contraction in the aorta only, (3) enhanced the relaxation elicited by acetylcholine (ACh) in both mesenteric arteries and aortas, and (4) increased nitrate [an indicator of nitric oxide (NO) formation] in plasma. The enhancement of ACh-induced relaxation in the mesenteric arteries in the Ex group was suppressed by pretreatment with N(omega) -nitro-L-arginine methyl ester (L-NAME), tetraethylammonium (TEA; a nonselective inhibitor of K(+) channels) or charybdotoxin [CTX; a selective inhibitor of large-conductance calcium-activated K(+) (BK(Ca)) channels], whereas in the aorta that response was attenuated by TEA or CTX and almost completely abolished by L-NAME. However, with a combination of L-NAME plus CTX in the mesenteric artery, ACh-induced relaxation was completely abolished in the Sed group, but not in the Ex group. These results suggest that in addition to NO, activation of BK(Ca) channels in the vascular beds, at least in part, also contributes to vasodilatation in animals with exercise training.     

胸部肿瘤放射治疗的研究进展

随着物理学、计算机技术、影像学的发展,放射治疗方法在最近几十年也有了显著的进步与发展,而放疗技术是治疗癌症行之有效的方法。本文主要综述了胸部肿瘤的放射治疗最新的进展,其中包括乳腺癌、肺癌、食道癌和纵膈肿瘤的放射治疗。细胞对放射线的敏感性在分裂期最高,在DNA合成期其敏感性最低。放射疗法既不损伤周围正常组织,仅仅对异常增殖的癌肿给予大量的杀伤,同时机体又再次尽可能发挥最大的调节功能。伴随胸部肿瘤放疗技术的进步,对治疗这些肿瘤有非常重要的临床意义。     

胸段硬膜外阻滞对家猪肝缺血再灌注时微循环的影响

目的：探讨胸段硬膜外阻滞对家猪肝缺血再灌注时微循环的影响。方法：14只健康幼年家猪,随机分为两组：硬膜外组（E组）和对照组（C组）,每组7只。基础麻醉后,进行气管插管机械通气,侧卧位行胸段硬膜外穿刺（T8-9）置管。经腹正中切口暴露肝脏,分离肝十二肠韧带,游离肝左动脉及门静脉左支备用。E组给予0．5％布比卡因0．75mL／节段（阻滞T5-T12脊神经）,C组给予相同容积的生理盐水。硬膜外给药15min后,夹闭肝左动脉及门静脉左支45min,然后开放肝左动脉及门静脉左支进行再灌注4h。分别在缺血前（TO）,缺血末（T1）,再灌注1h（T2）,2h（T3）,4h（T4）采血样用于测定AST,ALT,NO,ET-1,TNF-α,IL-1β和ATP。实验结束后取肝脏组织样本测定MDA和观察肝脏病理变化。结果：E组各时点MAP水平低于C组,有统计学差异（P〈0．05）;pH值以及PaC02两组间无明显差异;E组各时点AST,ALT,ET-1,TNF-α,IL-1β浓度低于C组,有统计学差异（P〈0．05）,NO及ATP浓度高于C组,有统计学差异（P〈0．05）;MDA含量c组高于E组,有统计学差异（P〈O．05）。光镜下可见E组肝组织损伤程度轻于C组。结论：胸段硬膜外阻滞可以增加肝脏能量的生成,纠正NO／ET的失衡,减少促炎介质的生成,从而改善微循环障碍的程度减轻肝缺血再灌注损伤。     

A comparison of the structure,composition and mechanical properties of anosteocytic vertebrae of medaka (O. latipes) and osteocytic vertebrae of zebrafish (D. rerio)

Medaka (O. latipes) and zebrafish (D. rerio) are two teleost fish increasingly used as models to study human skeletal diseases. Although they are similar in size, swimming pattern and many other characteristics, these two species are very distant from an evolutionary point of view (by at least 100 million years). A prominent difference between the skeletons of medaka and zebrafish is the total absence of osteocytes in medaka (anosteocytic), while zebrafish bone contains numerous osteocytes (osteocytic). This fundamental difference suggests the possibility that the bony elements of their skeleton may be different in a variety of other aspects, structural, mechanical or both, particularly in heavily loaded bones like the vertebrae. Here we report on the results of a comparative study that aimed to determine the similarities and differences in medaka and zebrafish vertebrae in terms of their macro- to nanostructure, composition and mechanical properties. Our results reveal many similarities between medaka and zebrafish vertebrae, making the lack or presence of osteocytes the only major difference between the bones of these two species.     

胸腔镜辅助小切口与传统开胸手术对胸外伤患者凝血功能及预后的影响

目的:探讨胸腔镜辅助小切口(VTAMS)与传统开胸手术对胸外伤患者凝血功能及预后的影响。方法:回顾性选取2017年7月~2019年2月期间我院收治的胸外伤患者91例,根据手术方式的不同分为A组(n=44,行传统开胸手术)和B组(n=47,行VTAMS手术),比较两组患者围术期指标、术前及术后7d的凝血功能指标、术后并发症发生情况及病死率。结果:B组术中出血量、术中输血量少于A组,手术时间、住院时间短于A组(P<0.05)。两组患者术后7d活化部分凝血酶原时间(APTT)、血小板(PLT)较术前降低,D-二聚体(DD)、凝血酶原时间(PT)较术前升高(P<0.05);B组术后7d的APTT、PLT高于A组,DD、PT则低于A组(P<0.05)。B组术后并发症发生率为10.64%(5/47),低于A组的27.27%(12/44)(P<0.05)。B组病死率为2.13%(1/47),低于A组的15.91%(7/44)(P<0.05)。结论:与传统开胸手术相比,胸外伤患者应用VTAMS手术治疗,可改善围术期指标,对凝血功能影响较轻,减少术后并发症的同时还可降低病死率。     

胸段硬膜外麻醉对心肌缺血再灌注损伤的影响

摘要 目的：心肌缺血再灌注损伤常常会导致心肌的凋亡和坏死,有研究表明胸段硬膜外麻醉（Thoracic epidural anesthesia,TEA）在心肌缺血再灌注损伤中的作用,因此,我们建立了心肌缺血损伤模型和胸段硬膜外麻醉模型来探讨胸段硬膜外麻醉对大鼠心肌缺血再灌注损伤(Myocardial ischemia-reperfusion injury,I/R)的影响。方法：SPF小鼠60只,随机分为正常组、I/R组及TEA组,分别采用TTC、HE染色、免疫组化、Western-blot等方法检测各组小鼠心肌组织及相关蛋白表达情况。结果：1.与正常组比较,I/R组和TEA组有较高的心肌梗死面积。与I/R组相比,TEA组心肌梗死面积明显减少,差异具有统计学意义（P<0.05）。2.TEA组上调了Akt、Hes1和Bcl-2的蛋白表达,下调了Notch 1、DTNA、BAX和HIF-1α的表达。结论：TEA对小鼠心肌缺血再灌注损伤具有保护作用。     

端粒生物学与胸主动脉瘤的研究进展

摘要：随着细胞生理性衰老,端粒（telomere）即染色体末端的重复性 DNA 序列会出现累积性损伤,而血管内皮细胞、平滑肌细胞衰老相关的端粒损伤和修复则被认为是退行性血管疾病发病的分子机制之一。胸主动脉瘤为老年人群中的重要致死性疾病之一,与衰老相关的退行性变在其中发挥着重要的作用。因此本文主要对端粒/端粒酶在胸主动脉瘤发病和进展中的作用做了概述,总结了血管病理学中端粒/端粒酶的调控机制。     

非编码RNA与胸主动脉瘤的研究进展

摘要：非编码RNA是一类缺乏编码蛋白能力的RNA,在机体发育和疾病发生发展过程中发挥着复杂而精确的调控功能。目前认为胸主动脉瘤（Thoracic aortic aneurysm, TAA）的发病涉及遗传因素、动脉内血流动力学变化、透壁炎症反应及细胞外基质降解和重构等。研究发现胸主动脉瘤病理进展过程中,易累及主动脉中膜平滑肌细胞,从而发生平滑肌细胞的丢失以及表型转化,而这些改变受到众多非编码RNA的调节。因此本文针对非编码RNA与胸主动脉瘤发病机制的密切关联做详细阐述。     

不同垂直骨面型错合畸形患者颈椎姿势差异的研究

目的：研究不同垂直骨面型错合畸形患者颈椎姿势的特点及差异,为正畸矫治错合畸形获得较好的临床效果及颅面、颈部生长发育的研究提供一定的参考依据。方法：采用计算机辅助X线头影测量技术,对226例不同垂直骨面型的儿童、成人在自然头位时拍摄的头颅定位侧位片进行测量研究,分别比较儿童以及成人不同垂直骨面型间颈椎姿势的差异。结果：儿童：CVT-OPT、SN-CP、SN-OPT及SN-CVT在低、均、高角各组间的差别均无统计学意义。成人：CVT-OPT在低角组与高角组间、均角组与高角组间的差别有统计学意义,高角组低于低角组和均角组,在低角组与均角组间的差别无统计学意义;SN-CP在低、均、高角各组间的差别有统计学意义,低角组〈均角组〈高角组;SN-OPT及SN-CVT在低角组与高角组间的差别有统计学意义,低角组〈高角组,在低角组与均角组间、均角组与高角组间的差别无统计学意义。结论：不同垂直骨面型错合畸形患者的颈椎姿势在儿童无显著差异,在成人差异显著。