气体溶解度的分子热力学 (Ⅳ)气体在海水中的Henry常数的预测

本文用气体在电解质溶液中溶解度的分子热力学模型,预测了气体在海水中的Henry常数、溶解焓及盐效应常数。当温度在0—35℃、盐度在0—40‰的范围内时,对11种气体溶解度的预测结果与实验值的偏差一般小于5%。     

海水直接肺损伤的犬模型研究

目的建立海水直接肺损伤的犬模型,为研究海水及其成分对肺直接损伤机制及其治疗提供研究平台。方法排除低氧血症和酸中毒等因素对海水直接肺损伤的影响,选择18只健康犬随机分为3组(n=6), 即全肺海水灌注组( A组)、右肺海水灌注组( R组)和右膈叶海水灌注组即海水直接肺损伤组(D组)。对比观察三组血流动力学、血气酸碱、电解质等指标以及肺组织细胞学改变,以支气管纤维镜连续观察D组三级支气管内海水灌注前后的变化,检测支气管肺泡液和血液乳酸脱氢酶(LDH-L)、碱性磷酸酶(ALP)浓度。结果(1)D组的动脉氧分压(PaO2)、动脉二氧化碳分压(PaCO2)、pH、实际重碳酸盐(AB)、过剩碱(BE)、呼吸频率、潮气量值与其余两组比较有显著差异(P<0.01)。(2)A组和R组各时段PaO2、Pa-CO2、pH、AB、BE、潮气量、呼吸频率值与海水灌注前相比有显著差异(P<0.01)。(3)D组血流动力学和血气酸碱及电解质等指标与海水灌注前相比无统计学差异(P>0.05)。(4)三组海水灌注区肺组织损伤均明显,出现充血水肿,局部有暗红色片状改变和梗死出血灶,光镜下可见肺泡水肿、肺泡萎陷、肺间质充血水肿明显及大量中性粒细胞浸润和肺出血。电镜下可见肺泡Ⅱ型上皮细胞损伤、呼吸膜增宽、血小板附壁。(5)支气管纤维镜连续观察D组海水灌注区支气管有不同     

Skeletal muscle activity of alcohol-treated rabbitts in immersion hypothermia: Adenine nucleotide concentrations and phosphorylation state

Summary The effects of alcohol injection (0.5 g·kg^–1i.v.) on the core cooling and rewarming rates, concentration of the adenine nucleotides, and the phosphorylation state of the adenylate system (ATP/ADP×P) were studied in the skeletal muscle of anesthetized rabbits immersed in ice-cold water. NaCl-injected rabbits immersed in ice-cold water were used as cold controls, alcohol-treated animals at room temperature (20°C) as alcohol warm controls, and NaCl-injected animals at room temperature as anesthesia controls, respectively.The fall of core temperature to 32°C in the alcohol-treated rabbits and the cold controls took about 40 min. During this time the temperature of the alcohol warm and anesthesia controls fell by about 1°C. No difference in the rewarming rate was observed between the alcohol-treated and cold control rabbits.Serum glucose concentration was elevated in the cold controls (from 5.9 to 8.3 mmol/l) but not in the alcohol-treated rabbits.Cold exposure reduced the phosphorylation state in the skeletal muscle of the alcohol-treated rabbits by 32% (P<0.05), but the decrease (6%) was not significant in the cold controls. After rewarming the phosphorylation state decreased in the above groups by 71% and 15%, respectively, as compared with the initial values. No significant changes in the phosphorylation state were found in the warm control animals.The redox state of the cytosol in the skeletal muscle or liver did not change, nor was there any change observed in the arterial pO₂ or pCO₂ concentrations.In conclusion, the results suggest an increased skeletal muscle activity during immersion hypothermia in alcohol-treated rabbits, but not in the controls.Dedicated to Professor W. Janssen on the occasion of his 60th birthday     

Renal hemodynamics and natriuresis during water immersion in normal humans

The renal vascular and functional responses to acute central hypervolemia by water immersion to the neck were determined in six normal subjects. During isotonic-isooncotic expansion by water immersion there was a significant increase in urine flow from 1.1±0.1 to 6.9±1.0 ml/min (p<0.05) and sodium excretion from 99.1±8.8 to 300±28 Eq/min (p<0.05). Glomerular filtration rate did not change while renal blood flow significantly increased during water immersion. Deep intrarenal venous pressure (IRVP) increased from 18.2±1.4 to 32±1.7 mmHg (p<0.05) while mean arterial pressure was unchanged. This marked natriuresis seen during water immersion was associated with reduced renal vascular resistance and increased deep intrarenal venous pressure demonstrating that continued natriuresis could relate to increased capillary hydrostatic pressure.     

Factors which affect shivering in man during cold water immersion

Six subjects were immersed in cold water (15.15±0.42°C) and were asked to perform two tasks. Shivering elicited by the cold water immersion was attenuated and/or abolished by the mental arithmetic task and in some instances by a voluntary isometric contraction of forearm muscles. Some reasons for these results are discussed.     

生理性海水喷雾洗鼻液治疗轻度间歇性变应性鼻炎患儿的疗效

目的观察生理性海水喷雾洗鼻液对儿童轻度间歇性变应性鼻炎(AR)的临床疗效及安全性。方法设计调查问卷,将上海4家医院哮喘及呼吸门诊符合轻度间歇性AR诊断标准的5～12岁患儿纳入研究,随机分为4个研究组,根据治疗方案设计分为生理性海水喷雾洗鼻液组(试验组)、氯雷他定组、联合治疗(生理性海水喷雾洗鼻液+氯雷他定)组及空白对照组,根据AR相关症状及体征评分标准对纳入研究的患儿随访4周,观察其临床疗效。结果共255例患儿完成本项研究,4组患儿入组前AR症状及体征评分差异均无统计学意义(Pa>0.05)。在改善AR症状评分方面,试验组、氯雷他定组分别于第2周、第3周起AR症状评分有明显改善(Pa<0.05),且试验组优于氯雷他定组。联合治疗组药后1周,AR症状评分与其他组比较差异均有统计学意义。在改善AR体征方面,治疗第4周,试验组、氯雷他定组与空白对照组比较差异有统计学意义(P<0.05),且试验组优于氯雷他定组。联合治疗组与其他组比较,在治疗第2周体征评分即有改善。本试验未出现试验药物导致的不良反应。结论生理性海水喷雾洗鼻液辅助治疗轻度间歇性AR可以有效地改善患儿鼻部症状及体征,与抗组胺药物联合使用效果更明显。     

肾上腺素对低温海水浸泡失血性休克大鼠血压的影响

目的:探讨肾上腺素对低温海水浸泡失血性休克大鼠平均动脉压和心率的影响及其机制。方法:成年雄性SD大鼠28只随机分为4组:正常组(N组,常温未作任何处理),肾上腺素组(E组,常温下失血性休克后注射肾上腺素),低温海水浸泡失血性休克+生理盐水组(DSN组),低温海水浸泡失血性休克+肾上腺素组(DSE组),每组7只,检测平均动脉压(MAP)和心率(HR)。结果:注射肾上腺素后,DSE组MAP前、中期高于正常组,末期迅速下降并低于正常组,但高于注射药物前的血压。E组血压发生了双向性变化。结论:低温海水浸泡失血性休克大鼠注射肾上腺素未能引起血压的双向性变化。     

不同海水浸泡时间对左氧氟沙星在腹部开放伤比格犬体内的药动学影响

目的建立腹部开放性创伤合并海水浸泡比格犬动物模型,研究左氧氟沙星（LVFX）在腹部开放性损伤合并海水浸泡比格犬与正常比格犬中的药动学变化。方法 12只比格犬随机分为3组,每组4只。A组为正常对照组,B组为腹部开放性创伤合并海水浸泡45 min组,C组为腹部开放性创伤合并海水浸泡90 min组。3组动物给药方案为：静脉输注LVFX25 mg/kg,60 min输注完毕。实验进程中监测实验动物体温。采用HPLC测定LVFX浓度;3P97计算药动学参数。结果腹部开放性创伤合并海水浸泡比格犬在浸泡过程中和出水后体温显著下降,且随浸泡时间增加而下降幅度增加。LVFX在比格犬体内呈二室模型,A、B和C组药动学参数分别为：Cmax（30.05±1.75）、（36.10±4.74）和（42.34±4.19）mg/L,t1/2β（8.23±0.65）、（11.02±0.54）和（13.19±3.87）h,AUC（247.00±14.10）、（345.22±56.68）和（417.79±83.32）mgoh/L,Vc（6.97±2.02）、（6.68±1.67）和（7.82±1.62）L,ClS（1.20±0.15）、（1.06±0.12）和（0.92±0.15）L/h。与A组比较,B组t1/2β和AUC显著增加（P〈0.05）;C组t1/2β、Cmax和AUC（t1/2β,P〈0.01;Cmax,AUC,P〈0.05）显著增加。与B组比较,C组t1/2β（P〈0.05）差异明显。结论腹部开放性创伤合并海水浸泡比格犬体内LVFX代谢消除随浸泡时间延长而明显减慢,其机制可能与浸泡导致的低体温状况有关。     

海水浸泡与低温对腹部开放伤大鼠血清VEGF含量的影响

目的研究海水浸泡与低温对腹部开放伤大鼠血清中血管内皮生长因子（VEGF）含量的影响。方法将sD大鼠随机分为腹部开放伤合并常温生理盐水浸泡组（对照组）、腹部开放伤合并低温生理盐水浸泡组（低温组）、腹部开放伤合并常温海水浸泡组（常温海水组）和腹部开放伤合并低温海水浸泡组（低温海水组）,各组浸泡1h后,分别检测实验大鼠血清中VEGF含量。结果海水浸泡、低温及其两者的交互作用对大鼠血清VEGF含量的影响均有统计学意义（P〈0．05或P〈0．01）。结论海水浸泡可引起大鼠血清VEGF含量升高,低温不能独立促使血清VEGF含量升高,但是可以加重海水浸泡引起的血清VEGF含量升高。