单唾液酸四己糖神经节苷脂对重度脑损伤的早期治疗作用

目的：探讨单唾液酸四己糖神经节苷脂（GM1）对重度颅脑外伤的早期脑保护作用。方法：入选者随机分为GM1治疗组及生理盐水（NS）对照组；于治疗前和治疗7、14d各进行格拉斯哥昏迷评分（GCS），检测血清乳酸（La）及C-反应蛋白（CRP）作比较。结暴：治疗7和14d后，治疗组La下降与对照组比较分别P〈0．05和P〈0．01;14d后治疗组GCS上升值与对照组比P〈0．05。结论：GM1能够降低无氧代谢。减轻La堆积所致酸中毒。从而减轻脑水肿，起到保护脑组织改善预后的作用。     

线粒体细胞病1例临床和基因突变分析

目的分析线粒体细胞病的临床表现、遗传学特点及其基因突变特点,从基因水平了解线粒体细胞病致病因素,并达到基因诊断和遗传咨询的目的。方法对1例线粒体细胞病患儿临床表现及实验室检查结果进行分析。提取患儿外周血基因组DNA,运用聚合酶链式反应先扩增患儿外周血线粒体基因3243、8344、8993三个热点突变所在片段,对扩增片段进行正反向序列测定,以检测突变。然后扩增已知的62个常见突变位点所在片段,对扩增片段同样进行正反向序列测定以检测突变。随机选择55例无血缘关系的健康成年人作为健康对照。结果男性患儿,出生2 d出现持续高乳酸血症、反复严重代谢性酸中毒、黄疸、肝功能异常、抽搐,头颅CT平扫示双侧大脑实质弥散性对称性低密度灶,2个月龄时死亡。线粒体3243、8344、8993三个位点均未发现突变,但细胞色素B基因存在15765 G→A突变,导致氨基酸序列340位由甘氨酸(G)转变为谷氨酸(E)。患儿母亲身体健康,外周血中亦同样存在该突变,患儿父亲及55例健康对照者皆无此突变。结论线粒体细胞病可表现为高乳酸血症、代谢性酸中毒、肝功能异常、神经系统疾病等多脏器功能损伤。线粒体细胞色素B基因15765 G→A突变可能是线粒体细胞病的一个致病突变。     

Continuously infused methylene blue modulates the early cardiopulmonary response to endotoxin in awake sheep

BACKGROUND: In endotoxemia and septic shock, enhanced generation of endogenous nitric oxide (NO) contributes to myocardial depression, hypotension, and derangement of gas exchange. We hypothesized that continuous infusion of methylene blue (MB), an inhibitor of the NO pathway, would counteract these effects in endotoxemic sheep. METHODS: Twenty-one sheep were anesthetized and instrumented for a chronic study with vascular catheters. On the day of the experiment, 18 conscious animals randomly received either an intravenous injection of MB 10 mg x kg(-1) or isotonic saline. Thirty minutes later, sheep received a 20-min intravenous infusion of Escherichia coli endotoxin 1 microg x kg(-1) and either an intravenous infusion of MB 2.5 mg x kg(-1) x h(-1) or isotonic saline, respectively, for 5 h. In addition, 3 animals were exposed to the same dose of MB alone. RESULTS: MB reduced the early endotoxin-induced declines in stroke volume, left ventricular stroke work and cardiac indices, and prevented mean arterial pressure from falling. Moreover, MB ameliorated the increases in pulmonary arterial pressure and pulmonary vascular resistance index. In addition, MB reduced the increments in venous admixture and AaPO2, decreased the falls in PaO2, SaO2, and oxygen delivery, and maintained oxygen consumption. MB also prevented the rises in body temperature and plasma nitrites and nitrates, and delayed the elevation of plasma lactate. When given alone to healthy sheep, MB transiently reduced plasma lactate and PaO2, and increased AaPO2. CONCLUSION: In ovine endotoxemia, continuously infused MB counteracts the early myocardial dysfunction and derangement of hemodynamics and gas exchange.     

乳酸依沙吖啶软膏的制备及质量控制

目的:制备乳酸依沙吖啶软膏并建立其质量控制方法。方法:以甘油、凡士林等为基质制备软膏;采用紫外分光光度法测定其中主药含量。结果:所制制剂性状、鉴别、检查等均符合2005年版《中国药典》相关规定;乳酸依沙吖啶线性范围为0.2～19.9μg·mL-1(r=0.9993);平均回收率为101.1%(RSD=1.75%)。结论:本制剂制备工艺简单可行,质量稳定可控。     

Transvascular fluid distribution of hyperoncotic Dextran solution

Purpose The purpose of this study was to confirm the changes in extra-aand intravascular fluid distribution during an i.v. influsion of hyperoncotic Dextran solution. Methods Twenty-three mongrel dogs with normal capillary integrities were divided into four groups. The R1 and R2 groups received i.v. infusion of Ringer lactate (RL) with a rate of 10 and 30 ml·kg⁻¹·h⁻¹, the D group 6% Dextran 70 solution (DEX) of 10 ml·kg⁻¹·h⁻¹. and the RD group DEX of 10 plus RL of 20 ml·kg⁻¹·h⁻¹. The distribution of infused fluid was assessed with the changes in circulating blood volume (CBV), extravascular fluid volume (EVW), and thoracic duct lymph volume (QL). Results In the R1 and R2 groups, EVW increased by 63% and 51%, respectively, of total infusion volume (tInf), while CBV increased by only 10% and 13% of tnf. In the D and RD groups, CBV increased by 103% and 51% of tInf. However, EVW decreased by 21% and increased by 32% of tInf, respectively. In the latter groups, the plasma volume filtered out into the extravascular compartment was less than in the corresponding former group by 52% and 6% of tInf, respectively and the restoration ratio of EVW by lymph was about 3 to 1.8 times greater. Conclusion One-fourth to one-third of the plasma expanding effect of 6% Dextran 70 solution was ascribed to direct fluid drawing from the extravascular space, and the rest was due to both the decrease in plasma filtration into extravascular space and the increase in lymphatic restoration of EVW.     

Menstrual and oral contraceptive cycle phases do not affect submaximal and maximal exercise responses

To examine whether the menstrual or monophasic oral contraceptive cycle phases affect submaximal (oxygen uptake (O₂) kinetics, maximal lactate steady-state (MLSS)) and maximal (O_2max, time-to-exhaustion (TTE)) responses to exercise in healthy, active women. During the mid-follicular or inactive-pill phase and the mid-luteal or active-pill phase of the respective menstrual or oral contraceptive cycle, 15 non-oral contraceptive users (mean and standard deviation (SD) (±): 27 ± 6 years; 171 ± 5 cm; 65 ± 7 kg) and 15 monophasic oral contraceptive users (24 ± 4 years; 169 ± 10 cm; 68 ± 10 kg) performed: one O₂ kinetics test; one ramp-incremental test; two to three 30-minute constant-load cycling trials to determine the power output corresponding to MLSS (MLSS_p), followed by a TTE trial. The phase of the menstrual or oral contraceptive cycle did not affect the time constant of the O₂ kinetics response (τO₂) (mid-follicular, 20 ± 5 seconds and mid-luteal, 18 ± 3 seconds; inactive-pill, 22 ± 8 seconds and active-pill, 23 ± 6 seconds), O_2max (mid-follicular, 3.06 ± 0.32 L min⁻¹ and mid-luteal, 3.00 ± 0.33 L min⁻¹; inactive-pill, 2.87 ± 0.39 L min⁻¹ and active-pill, 2.87 ± 0.45 L min⁻¹), MLSS_p (mid-follicular, 181 ± 30 W and mid-luteal, 182 ± 29 W; inactive-pill, 155 ± 26 W and active-pill, 155 ± 27 W), and TTE (mid-follicular, 147 ± 42 seconds and mid-luteal, 128 ± 54 seconds; inactive-pill, 146 ± 70 seconds and active-pill, 139 ± 77 seconds) (P > .05). The rate of perceived exertion (RPE) at minute 30 of the MLSS_p trials was greater in the mid-follicular phase (6.2 ± 1.5) compared with the mid-luteal phase (5.3 ± 1.4) for non-oral contraceptive users (P = .022). The hormonal fluctuations between the menstrual and oral contraceptive cycle phases had no detectable effects on submaximal and maximal exercise performance, even when RPE differed.     

Lactate doublet quantification and lipid signal suppression using a new biexponential decay filter: application to simulated and 1H MRS brain tumor time-domain data.

A new postprocessing filter based on the continuous wavelet transform (CWT) method modeled as a biexponential decay function to isolate the lactate doublet from overlapping lipid resonance(s) and estimate its magnetic resonance spectroscopy (MRS) parameters (signal amplitude, resonance frequencies, and apparent relaxation time (T(*) (2))) is proposed. The new filter employs the same iterative process used in the previously single exponential decay filter. A comparison of the results obtained from application of both filters to simulated data and real (1)H MRS data collected from human blood plasma and brain tumors demonstrates that the new filter provides a better estimate of MRS parameters of lactate, with less computation time. Furthermore, the results show that the new filter is less sensitive to noise and provides a direct estimate of J-coupling value of the lactate doublet.     

Separation of intra- and extracellular lactate NMR signals using a lanthanide shift reagent.

This work describes the use of [Pr-DO3A] as a shift reagent for differentiating intra- and extracellular L-lactate resonance in (1)H- and (13)C-NMR spectra. DO3A acts as heptadentate ligand towards lanthanide(III) ions, leaving two coordination vacancies for the coordination of the L-lactate ion. The exchange between free and [Pr-DO3A]-bound L-lactate is fast on the NMR timescale, thus yielding a paramagnetically shifted L-lactate signal for the substrate in the compartment containing the paramagnetic chelate. The evaluation of the method was carried out on a model system based on sealed ghosts from human red blood cells.     

刺五加茶饮料抗疲劳作用的实验研究

目的 :　研究刺五加茶饮料对小鼠的抗疲劳作用。方法 :　 48只昆明系小鼠平均分成 4组 ,其中刺五加茶饮料分 5 0 ,75 ,1 0 0 ml/(kg· d)三个剂量组给小鼠灌胃 ,对照组给等剂量生理盐水。共 2 8d,末次饲喂 3 0 min后无负重游泳 ,测定运动耐力、肌糖原、肝糖原、乳酸脱氢酶(LDH)、血乳酸 (LAC)、血尿素氮 (BUN)等指标。结果 :　三个剂量的刺五加茶饮料均能显著提高运动后 LDH活力 ;降低血 LAC和 BUN的含量 ;提高小鼠体内肌糖原和肝糖原的储备量 ;提高小鼠运动耐力。 75～ 1 0 0 ml/(kg· d)最佳。结论 :　刺五加茶饮料具有良好的抗疲劳作用。