血粘度增加对家兔高空减压气泡生成的影响

目的 观察家兔血液粘度增加对高空减压气泡生成的影响。方法 家兔禁水2天,禁水前后测量血液流变学指标。进行高空减压(12000m,停留20min),用多普勒超声法检测心前区气泡生成情况。结果 血液流变学指标的全血粘度和血浆粘度均有升高(P<0.05),红细胞比容无明显变化。结论 血液粘度轻度升高对高空减压气泡的生成无明显的影响。     

口服酒精溶液对豚鼠高空减压气泡生成的影响

目的为建立高空减压病易感性的筛选指标提供实验依据，我们观察了豚鼠口服酒精后高空减压时体内气泡生成的变化。方法30只豚鼠随机分成3组，其中两组分别在口服50％酒精溶液4.0和8．0ml后10.min和20min减压至13000m高度。用超声多普勒装置检测豚鼠心前区气泡音。结果口服8．0ml酒精溶液后减压，气泡生成明显增加（P＜0．01），血浆表面张力明显降低（＜0．01）。结论减压前饮酒能明显促进动物高空减压气泡的生成。     

被动吸烟对豚鼠高空减压气泡生成影响的初步观察

观察了３０只豚鼠于密闭舱内被动吸入卷烟烟雾对随后高空减压心前区气泡出现的影响。结果表明：在上述２种吸入卷烟烟雾的条件下，减压气泡的首次出现时间和气泡等级与对照组相比无显著差异。初步提示减压露前短时间大量吸烟不会影响高空减压病的发生。     

高空减压气泡的多普勒超声检测

1968年，Spencer等以及Gillis等将多普勒(Doppler)超声血流测定技术加以改进，应用于高压一减压实验动物血管中气泡的检测以来，现已发展为广泛使用的无创性人体心前区气泡检测方法，成为潜水医学、航空航天医学中减压病的有效研究手段之一，并为该领域谱写了新篇章。我国海军医学研究所1975年首先开始应用Doppler超声技术于科研工作，也已获得一定成果。     

高气压减压中生理性气泡的形成

为了探讨高气压暴露后减压过程中气泡的来源和生长,通过分析总结该领域的全部文献,对相关的研究以及当前进展进行综述。在过去50多年中,潜水医学、生理学、有机化学和物理学等专业人员对该问题进行了持续关注,提出了多个理论模型,解释了潜水实践中的很多现象,但仍有很多问题未获解答。在气泡的形成中,异相成核仍是最有证据的机制,表面疏水性和组织弹性是解释气核稳定性的2个主要理论;在单气泡和多气泡的生长方面将有更多的研究予以关注。     

超声测量技术用于兔皮肤内高空减压气泡测量的探讨CSCD

目的：针对高空减压病病因学气泡生成的机制,探讨了用皮肤超声测量技术检测兔皮肤内减压气泡生成的可行性。方法测量者上升前呼吸纯氧排氮15 min后和家兔一起以30～50 m／s的速度上升到8000 m。在停留5 min和10 min时分别对家兔腹部皮肤进行超声测量,每个部位重复测量10次。测量仪器为德国MINHORST GobH公司生产的Collagenoson‐ICU皮肤高频回声断层扫描仪,其发射频率为22 M Hz ,探测孔径2 mm ,探测深度15 mm ,测量分辨率为0．15 mm。结果高空减压后,兔皮肤扫描图像中代表存在气体界面反射的明亮像素增多,减压前后的像素均值差异有统计学意义（ F＝11．162, P＜0．01）;减压后的像素值明显高于减压前（ P＜0．01）。结论本研究初步证明皮肤超声测量可望为减压病气泡生成的客观检测提供一个新的潜在指标。     

吸氧排氮对家兔低气压暴露时气泡产生的影响

目的 探讨不同时间的吸氧排氮方案对高空减压病的预防效果。方法 24只家兔随机分为对照组、吸氧排氮30、60和120min组4组。麻醉后行机械通气,分别吸氧排氮0、30、60和120min后上升至11000m停留30min,用超声多普勒技术检测气泡产生情况。结果 高空减压时气泡首次检出时间随着吸氧排氮时间的增加而延长,吸氧排氮60min和120min组家兔气泡首次检出时间较对照组显著延长(P＜0．01),气泡首次检出时间与吸氧排氮时间呈正相关关系(P＜0．01);累积气泡数随着吸氧排氮时间的增加而减少,吸氧排氮60min和120min组家兔累积气泡数较对照组显著减少(P＜0．01),累积气泡数与吸氧排氮时间呈负相关关系(P＜0．01)。结论 吸氧排氮60min和120min两种方案可以显著减少兔由地面上升到11000m高空减压时气泡的产生。     

不同强度微波辐射对小鼠脑组织钙、镁ATP酶活性的影响

目的　探讨微波对机体中枢神经系统作用的机理。　方法　用 2 45 0 MHz连续波微波理疗机为辐射源 ,以昆明小鼠为对象 ,观察在 1m W/ cm2、5 m W/ cm2和 10 m W/ cm2三种照射强度下 ,小鼠脑皮层、海马及丘脑细胞膜 Ca2 、Mg2 - ATP酶活性的变化情况 ,用组织化学方法测定其活性。　结果　 1m W/ cm2时 ,皮层、海马及丘脑 Ca2 、Mg2 - ATP酶活性均比对照组高 (P<0 .0 5 ) ,5 m W/ cm2 时 ,酶活性与对照组差别均无显著性的意义 ,10 m W/ cm2 时 ,皮层、海马酶活性比对照组显著降低 ,而丘脑则无明显变化。　结论　 2 45 0 MHz微波照射小鼠时 ,脑组织细胞膜上 Ca2 、Mg2 -ATP酶活性随照射强度不同而有不同变化。受高强度照射时 ,参与学习记忆功能的皮层、海马先于参与体温调节功能的丘脑受到影响     

微波辐照大鼠脑对海马回细胞内游离钙的影响

随着现代科技的发展,微波与人类接触越来越密切,因而对其机理及防护的研究越来越受到人们的重视.通过对高能微波作用于大鼠脑组织后,观测海马回细胞内游离Ca~(2 )浓度变化规律,来探讨微波对神经细胞损伤的作用机理.用合格的Wistar大鼠,随机分为辐照组和对照组,以荧光显示法观测Ca~(2 )浓度,发现辐照组Ca~(2 )浓度明显升高,与对照组相差极显著.     

低强度脉冲电磁场对兔凝血酶原时间和活化部分凝血活酶时间的影响

目的探讨低强度脉冲电磁场对兔血液凝血时间的影响。方法健康雌性新西兰大耳白兔30只,随机分为3组,正常组（A组）用常规饲料喂养,模型组（B组）和磁场组（C组）用高胆固醇饲料喂养,C组暴露饲养于低强度脉冲电磁场环境中。饲养7W后,采血用比浊法检测凝血酶原时间（PT）和活化部分凝血活酶时间（APTT）。结果比较各组胛和APTF,B组低于A组（P〈0．01）;C组高于B组（P〈0．01）;A组和C组差异无统计学意义。结论低强度脉冲电磁场可以明显延长盯和APTT,提高血液流动性,为心血管疾病预防提供新思路。     

SOD对高原犬体外循环心肌再灌注损伤的保护作用

目的：探讨SOD在高原地区体外循环中的心肌保护作用。方法：将20只杂种犬随机分成A组（对照组，n=10）和B组（试验组n=10)，模拟临床浅低温体外循环，B组停博液中加入SOD6万U/100ml，分别于CPB前、30min,60min及CPB后2h取样测定心肌组织中的MDA，冠状静脉血中CPK浓度以及心肌组织的病理改变，比较两组的差异。结果：A组心肌组织中MDA含量在CPB60min及CPB后2h明显高于B组；A组冠状静脉血中CPK浓度在CPB60min及CPB后2h明显高于B组；CPB后A组心肌发生了更明显的损伤性病理改变。结论：SOD具有减轻高原体外循环心肌再灌注损伤的作用。     

Effects of breathing an O2-H2 (20%-80%) mixture on the energy metabolism of the eel at 1 ATA

The hypothesis of a specific effect of hydrogen on living organisms was investigated. Three tissues were studied: brain, muscle, and liver. Nucleotide concentrations (ATP, ADP, AMP, IMP, NAD) were determined using an HPLC method, and energy charge (EC) was calculated. These measurements were performed at atmospheric pressure for 50 or 132 h. Experiments were carried out using 15 control eels that breathed aerated water and 15 eels that breathed water saturated with oxygen (20%) and hydrogen (80%). No significant variation was found of the measured concentrations in muscle or liver, irrespective of the exposure duration to H2. In contrast, hydrogen induced in brain tissue a significant increase of AMP (p less than 0.005) and significant decreases of ATP (p less than 0.005) and EC (p less than 0.001). It should be noted that the EC decrease is already significant (p less than 0.05) after 50 h of exposure to H2. These modifications in energetic nucleotides were coupled with a small decrease of NAD (NS) in the three tissues explored. From the present results, obtained from eels at atmospheric pressure, it appeared that hydrogen could induce a perturbation of energy metabolism at the brain level. Its origin could be a partial saturation of respiratory chain carriers with exogen H2.     

Effects of pedal frequency on VO2 and work output at lactate threshold (LT), fixed blood lactate concentrations of 2 mM and 4 mM, and max in competitive cyclists

To determine the effects of differing pedal frequencies on VO2 and work output values at the lactate threshold (LT), fixed blood lactate concentrations of 2 mM and 4 mM (2 mM, 4 mM), and at max, nine male competitive road racing cyclists (USCF category I or II) completed three VO2 max tests; on a Monark bicycle ergometer, at pedal frequencies of 60, 90, and 120 rpm. Each stage was 3 min in duration, starting at 0 kgm/min with subsequent stages increased by either 180 kgm/min (60 and 120 rpm) or 178 kgm/min (90 rpm). Blood samples were taken during the last 30 s of each stage. VO2 and work output at LT, 2 mM, and 4 mM were determined from individual blood lactate-work rate and VO2-work rate relationships. VO2 max and maximal work output were chosen as the peak values observed during the VO2 max tests. Results indicated that work output at LT, 2 mM, and 4 mM was affected by choice of pedal frequency (1278, 1140, 999 kgm/min at LT; 1533, 1450, 1182 kgm/min at 2 mM; 1780, 1703, 1487 kgm/min at 4 mM; for 60, 90, and 120 rpm, respectively, P less than 0.05). Max work output at 60 and 90 rpm was significantly greater (P less than 0.05) than at 120 rpm (2035, 2053, 1879 kgm/min for 60, 90, and 120 rpm, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

The Effects of Na~+/Ca~(2+) exchange (NCX) on the Repolarization of Canine Ventricular Myocyte-Potential Arrhythmogenic Effect of NCX during a Mis-matched Repolarization and Relaxation Xiamen Zhongshan Hospital, Xiamen Medical College, Xiamen University

The Effects of Na~+/Ca~(2+) exchange (NCX) on the Repolarization of Canine Ventricular Myocyte-Potential Arrhythmogenic Effect of NCX during a Mis-matched Repolarization and Relaxation Xiamen Zhongshan Hospital, Xiamen Medical College, Xiamen University@巩燕$Visiting scholar of cardiac arrhythmia research institute,university hospital of Oklahoma!U.S.A @王焱 @BELA Szabo$Basic cardiac research laboratory,cardiac arrhythmia research institute,university hospital of Oklahoma!…     

The efficacies of pure LICAM(C) and DTPA on the retention of plutonium-238 and americium-241 in rats after their inhalation as nitrate and intravenous injection as citrate

The pure carboxylated catechoyl amide LICAM(C) and the calcium and zinc salts of diethylenetriaminepenta-acetic acid (DTPA), were tested for efficacy for removing 238Pu and 241Am from rats after inhalation of the nitrate or intravenous injection of the citrate. The results were compared with the efficacy of methylated LICAM(C) used in previous experiments. It was shown that: (1) after inhalation of 238Pu nitrate, DTPA was far superior to pure LICAM(C); (2) after intravenous injection of 238Pu citrate, the infusion of DTPA plus LICAM(C) was only marginally more effective than DTPA alone; and (3) after inhalation or intravenous injection of 238Pu plus 241Am, the efficacy of pure LICAM(C) was only marginally more effective than the methylated form and neither form was effective for the decorporation of 241Am. It was concluded that DTPA, at present, remains the chelating agent of choice for treating persons accidentally contaminated with transportable forms of Pu and Am.