营养干预对骨髓移植病人抗氧化力及脂质过氧化的影响

目的探讨外源性补充抗氧化性维生素对骨髓移植病人抗氧化力及脂质过氧化的影响。方法将19名骨髓移植病人随机分为实验和对照组,实验组在预处理前给予维生素C(300 mg/d)和维生素E(600 mg/d),对照组不予补充,其余处理两者相同。测定移植前后两组病人的血浆总抗氧化力、丙二醛、全血谷胱甘肽过氧化物酶及红细胞超氧化物歧化酶水平。结果(1)移植前后实验组血浆总抗氧化力、谷胱甘肽过氧化物酶和红细胞超氧化物歧化酶值一直处于正常或正常值附近,对照组则低于正常值,两组相比有显著差异;(2)移植后实验组丙二醛值很快降至正常,对照组则一直处于较高水平,两组有显著差异。结论移植前外源性补充抗氧化性维生素可提高骨髓移植病人机体的抗氧化力,减少了脂质过氧化物的产生,有效缓解移植前大剂量放、化疗对病人机体造成的高氧化胁迫压力。     

Off-resonance effects in the transient response of SSFP sequences.

A previously developed eigenvector formalism is adapted to off-resonance in the transient response of quasiperiodic steady-state free precession (SSFP) sequences, including TrueFISP as a special case. The effective relaxation rates for essentially parallel and perpendicular deviations from the steady state are determined analytically in leading order perturbation theory. The latter are a known cause of oscillatory artifacts and therefore constitute the main target of a variety of preparation techniques. In addition, the former also play a dominating role in applications such as inversion recovery (IR) TrueFISP, which intentionally measure far away from the equilibrium. For both components, the approach toward equilibrium turns out to depend sensitively on field inhomogeneities, especially for smaller ratios of T2/T1. For the perpendicular deviations, the calculations show that--except very close to banding artifacts, where the steady-state signal is almost zero--field inhomogeneities additionally increase their effective relaxation rate almost as much as in the free induction decay (FID). The analytical results are tested against numerical simulation and MR measurements.     

View ordering for magnetization prepared steady state free precession acquisition: application in contrast-enhanced MR angiography.

Magnetization prepared segmented acquisition requires a view order that maximizes signal contrast during the acquisition of the central portion of k-space. Steady state free precession (SSFP) acquisition further requires a view order that minimizes changes in phase-encoding gradients from one repetition to the next in order to minimize eddy current artifacts. In this article, optimal view ordering schemes satisfying these two requirements are formulated and applied to inversion prepared 3D SSFP contrast-enhanced MR angiography (MRA). Experiments on phantoms and pigs demonstrated improved background suppression and reduced image artifacts.     

汉防己甲素抑制三种神经递质引起的新生大鼠脑细胞内游离钙的升高

应用Ｐｕｒａ－２技术测定游离新生大鼠脑［Ｃａ２＋］ｉ浓度的技术、研究了Ｔｅｔ对静息脑［Ｃａ２＋］ｉ和３种递质引起的脑［Ｃａ２］ｉ变化的影响。Ｔｅｔ（１，１０和２０μｍｏｌ·Ｌ－１）对静息脑［Ｃａ２＋］ｉ无明显影响。Ｔｅｔ（１０μｍｏｌ·Ｌ－１）可降低Ｌ－Ｇｌｎ（０．１、１．０和１０μｍｏｌ·Ｌ－１）引起的脑（Ｃａ２＋）ｉ的升高。在Ｈａｎｋ＇ｓ液Ｃａ２＋为１．３ｍｍｏｌ·Ｌ－１时，Ｔｅｔ１０μｍｏｌ·Ｌ－１可降低Ｈｉｓ（５０和１００μｍｏｌ·Ｌ－１）和５－ＨＴ（０．１、１．０、１０和１００μｍｏｌ·Ｌ－１）引起的脑［Ｃａ２＋］ｉ的升高。但不能降低Ｈａｎｋ＇ｓ液无Ｃａ２＋时Ｈｉｓ和５－ＨＴ引起的脑［Ｃａ２＋］ｉ的升高。研究表明Ｔｅｔ可阻滞Ｌ－Ｇｉｎ、Ｈｉｓ和５－ＨＴ受体调控的钙通道。但对Ｈｉｓ和５－ＨＴ引起的细胞内贮存钙的释放并无明显影响。Ｔｅｔ的这种降低脑［Ｃａ２＋］ｉ的作用可能是其治疗脑缺血性疾病的机理之一。Ｐ＜０．０１在Ｔｅｔ１０μｍｏｌ·Ｌ－１作用下，相同浓度的细胞外液钙和Ｈｉｓ（０、５０和１００μｍｏｌ·Ｌ－１），脑［Ｃａ２＋］ｉ分别是２２１±５、２４５±５和３０２±６ｎｍｏｌ·Ｌ－１。增加了１１．８?     

1000例正常人发电子自旋共振（ESR）波谱的饱和特性研究

本文报道1000例正常人发自由基的电子自旋共振波谱饱和功率(ESR-SP)的检测结果。所得正常值的全组中位数为2.496mw;95％上下限分别为2.989及1.720mw。如按性别统计,则女性下限(1.617mw)较男性(1.983mw)为低,(P<0.05)。按年龄分别统计,则40岁以上的中位数(2.376mw)及其下限(2.009mw)高于40岁以下的中位数(2.548mw)及其下限(1.597mw),两者差异有显著性(P<0.05)及极显著性(P<0.01)。因此在使用此正常值指标时,必须注意性别与年龄因素。     

流行性出血热患者血清超氧化物歧化酶、丙二醛含量变化与其发病机理的关系

本文测定32例健康人和101例流行性出血热(EHF)患者血清超氧化物歧化酶(SOD),丙二醛(MDA)的含量。结果表明EHF患者血清SOD、MDA含量均高于健康对照组,以低血压少尿期升高最为明显。测定中还发现SOD、MDA含量升高与病情变化程度有一定关系。作者认为自由基参与了EHF的发病过程。研究EHF与自由基的关系有助于进一步阐明EHF的发病机理并为其临床治疗提供一定的参考价值。     

Additive effects of earthworm extract with HpD-laser on the enhancement of reactive oxygen production and the inhibition of[~3H]—thymidine.uptake in mouse ascitic tumor cells

The effects of combined use of earthworm extract(912)and HpD-laser on the produc-tion of reactive oxygen and the biosynthesis of DNA in S_(180) tumor cells were studied throughchemiluminescence measurement and[~3H]-TdR incorporation assay.The results showed that as com-pared with the control,the intensity of chemiluminescence emitted by tumor cells treatedsimultaneously with 912 and HpD-laser was enhanced more than ten-folds,while that treated with912 or HpD-laser alone was increased only 2～4 folds.The[~3H]-TdR incorporation into tumorcells of the former group was inhibited upto 74.1%,and that of the latter groups decreased onlyby 42.2% and 40.0%,respectively.In accordance with these biochemical changes,the ultrastructuraldamage of tumor cells of the former,combinedly treated group appeared to be the most serious.This suggests an additive effect of 912 with HpD-laser on tumor cells.In addition,if free radicalscavengers,such as catalase and superoxide dismutase,were added to the reaction systembefore chemiluminescence assay,the luminescent enhancement effect mentioned above was dramaticallyalleviated,implying the presence of O_2~ and H_2O_2 in the system.Therefore,as to the toxic effecton tumor cells,912 and HpD-laser are not only additive in efficiency,but also similar in theunderlying mechanism of action.     

Dorsal root ganglia cocultured with macrophages: an in vitro model to study experimental demyelination

The present investigation introduces an in vitro model to study macrophage properties during demyelination. Rat dorsal root ganglia (DRG) were cultured for obtaining myelinated peripheral nerve fibers. These cultures were exposed to non-resident macrophages. In untreated control cultures, there was no indication of myelin removal by the added macrophages. DRG were exposed to enzymatically generated oxygen radicals using the xanthin/xanthin oxidase or the glucose/glucose oxidase system. Assessment of Schwann cell viability and ultrastructural morphology revealed different patterns of cell cytotoxicity and morphological changes in different experiments. High concentrations caused complete tissue necrosis of the DRG, while low concentrations did not affect either cell viability or ultrastructural morphology. Under intermediate experimental conditions, oxygen radicals caused non-lethal Schwann cell damage leading to Schwann cell retraction and myelin sheath rejection. Myelin lamellae were disrupted and decompacted. These changes were followed by a selective macrophage attack on myelin sheats, resulting in demyelination. Axons, Schwann cells and sensory ganglion cells survived this attack. The specificity of the oxygen radical effects was tested in experiments using the oxygen radical scavengers catalase and superoxide dismutase. Catalase prevented the described effects on cell morphology and subsequently blocked demyelination by non-resident macrophages.Supported by a grant from the Deutsche Forschungsgemeinschaft (DFG) (Br 1274/1-1)     

非体外循环冠状动脉搭桥手术的麻醉方法及血液动力学和氧代谢的变化

目的 观察非体外循环冠状动脉搭桥手术的麻醉方法、术中病人血液动力学和氧代谢的变化以及术后病人的早期.非体外循环冠状动脉搭桥手术闰人20例，麻醉用咪唑安定0.1-0.2mg/kg、芬太尼15－30μg/kg及0.5%-2%的吸入麻醉药等，在切皮前、开心包后、心脏操作中、操作完成后10min及术毕观察血液动力学指标及脑氧饱和度，同时采集桡动脉和肺动脉血，测定血气及动脉血乳酸（ABL），计算氧供DO2）、氧耗（VO2）和氧摄取率（ERO2）。术后早期观察术后拔除气管插管、ICU停留及术后住院时间、并发症及死亡等情况。结果 心脏操作中MAP、SV、SI下降，HR、CVP升高，MAP下降以搭回旋支时最明显（P＜0.01），HR升高以搭右冠时最明显（P＜0.01）；心脏操作中DO2降低（P＜0.05），VO2无变化，ERO2升高（P＜0.01）；操作后DO2、ERO2恢复至操作前水平；操作后ABL升高（P＜0.01）。结论 本组麻醉方法使病人完全度过非体外循环搭桥术，在心脏操作期易出现血压、每搏量、心指数下降，伴心率、静脉压升高，但时间短暂无严重后果，氧代谢紊乱及缺氧程度较轻。     

Curative resection of gastric cancer: Limitation of peritoneal lavage cytology in predicting the outcome

Patients with stage T3N0～2M0 gastric carcinoma (n = 108) were studied for relevant prognostic factors. Peritoneal lavage cytology (PLC) was performed in all. In univariate analysis, 5-year survival rates were better with smaller serosal invasion (diameter <3.0 cm vs. ≥3.0 cm, 61% vs. 37%, P < 0.05) and fewer metastatic nodes (≤5 vs. ≥6, 57% vs. 29%, P < 0.05). In multivariate analyses, only these two factors were significant. The predictive value of PLC was not shown in both univariate and multivariate analyses. Peritoneal recurrence occured in 14 (22%) of 77 patients with negative PLC, and in 3 (18%) of 17 with positive PLC, the difference being not significant. Our results indicate that PLC is insensitive in predicting the development of peritoneal recurrence. Its role in the estimation of survival is limited, as many will die of visceral or locoregional recurrence if not of peritoneal dissemination.