谷氨酰胺在危重病患者中的应用

目的探讨危重病患者中早期经静脉应用谷氨酰胺（glutamine，Gl）的临床价值。方法42例患者随机分成两组（对照组和Gln组），Gln组进行Gln治疗（100mL／d，共7d）。治疗前后检测患者体质量、白蛋白、谷胱甘肽（GSH）、握力的变化和肠功能不全的发生率。结果体质量两组治疗前后比较差异无显著性（P〉0．05）。白蛋白、握力和GSH Gl治疗后非常显著高于治疗前（P〈0．01）；白蛋白对照组治疗后较治疗前显著增高（P〈0．05），但握力和GSH治疗前后均无显著变化（P〉0.05）；肠功能不全的发生率Gln组为4．8％，显著低于对照组（28．6％，P〈0．05）。结论在危重病患者疾病早期通过静脉途径外源性地补充Gln，有效改善了患者的营养状况；使患者血浆中的GSH水平增高，加强了机体的抗氧化能力；减少了患者肠功能不全的发生率。     

丁胱亚磺酰亚胺排空组织谷胱甘肽对大鼠心肌谷胱甘肽系统的影响

目的:观察采用谷氨酰半胱氨酸合成酶抑制剂--丁胱亚磺酰亚胺(BSO)排空大鼠心肌谷胱甘肽(GSH)是否影响大鼠心肌组织GSH的稳态,以及是否对GSH代谢相关酶活性及mRNA表达产生影响.方法:采用长时间力竭运动、注射BSO排空GSH两种实验模型,比较对照组与注射BSO组SD大鼠心肌在静息状态和长时间力竭运动后GSH状态及其代谢变化.结果:注射BSO 8天后,大鼠心脏GSH含量分别为对照组?%,且GSH的下降伴随着氧化型谷胱甘肽(GSSG)的下降,GSH/GSSG的比值无显著变化.GSH排空导致GSH代谢酶活性发生适应性变化,注射BSO后心肌中谷胱甘肽过氧化物酶(GPX)活性与对照组相比显著下降(P < 0.001).注射BSO组与对照组相比,心肌谷氨酰转肽酶(GGT)活性显著增加(P < 0.05).注射BSO力竭组与注射BSO组相比,心肌GGT活性显著增加(P < 0.001),心肌注射BSO抑制γ-谷氨酰半胱酸合成酶(GCS)活性,注射BSO力竭组大鼠心肌GCS mRNA表达量高于注射BSO组,表明极度排空谷胱甘肽后,GCS mRNA表达量的增加可能是机体产生的应激反应.     

五味子酚对氧自由基引起大鼠脑突触体和线粒体损伤的保护作用

以Fe²⁺-半胱氨酸(Cys)为氧自由基生成系统,在体外模仿脑出血或脑外伤引起的氧自由基损伤的模型,观察五味子酚是否对Fe²⁺-Cys引起的大鼠脑突触体和线粒体损伤有保护作用,以探讨Sal用于延缓衰老、防治某些神经系统疾病的可能性。结果显示,与Fe²⁺-Cys共温孵可使脑突触体和线粒体MDA生成量显著增加,线粒体ATPase活性下降。而预先加入Sal(10^{-6mol·L-1)可抑制MDA生成,防止线粒体ATPase活性降低。Sal对Fe2+-Cys引起的线粒体肿胀和膜流动性降低也有明显的保护作用,并能防止Fe2+-Cys所致线粒体和突触体形态的病理性损伤。结果提示,Sal对氧自由基引起的大鼠脑突触体和线粒体损伤有明显保护作用。}     

Thiols decrease cytokine levels and down-regulate the expression of CD30 on human allergen-specific T helper (Th) 0 and Th2 cells

The thiol antioxidant N-acetyl- L-cysteine (NAC), known as a precursor of glutathione (GSH), is used in AIDS treatment trials, as a chemoprotectant in cancer chemotherapy and in treatment of chronic bronchitis. In vitro, GSH and NAC are known to enhance T cell proliferation, production of IL-2 and up-regulation of the IL-2 receptor. The 120-kD CD30 surface antigen belongs to the tumour necrosis factor (TNF) receptor superfamily. It is expressed by activated T helper (Th) cells and its expression is sustained in Th2 cells. We have analysed the effect of GSH and NAC on the cytokine profile and CD30 expression on human allergen-specific T cell clones (TCC). TCC were stimulated with anti-CD3 antibodies in the presence of different concentrations of GSH and NAC. Both thiols caused a dose dependent down-regulation of IL-4, IL-5 and IFN-gamma levels in Th0 and Th2 clones, with the most pronounced decrease of IL-4. Furthermore, they down-regulated the surface expression of CD30, and the levels of soluble CD30 (sCD30) in the culture supernatants were decreased. In contrast, the surface expression of CD28 or CD40 ligand (CD40L) was not significantly changed after treatment with 20 m M NAC. These results indicate that GSH and NAC favour a Th1 response by a preferential down-regulation of IL-4. In addition, the expression of CD30 was down regulated by GSH and NAC, suggesting that CD30 expression is dependent on IL-4, or modified by NAC. In the likely event that CD30 and its soluble counterpart prove to contribute to the pathogenesis in Th2 related diseases such as allergy, NAC may be considered as a future therapeutic agent in the treatment of these diseases.     

Lipid peroxidation and antioxidant status in human cervical carcinoma

Reactive oxygen species (ROS), represented by superoxide, hydrogen peroxide and hydroxyl radicals, have been implicated in many diseases including cancer. ROS have been known to play an important role in the initiation and promotion of multistep carcinogenesis. The cellular antioxidants play a crucial role in protection against neoplastic disease. However, very little is known about the antioxidant defense in cervical carcinoma. This is addressed in the present study. Lipid peroxides, glutathione content and the activities of antioxidant enzymes, together with vitamin C and E content, were estimated in patients who had carcinoma of the cervix, and the values were compared with those of normal women. The results showed a remarkable reduction in the content of glutathione, vitamin E and C. Activities of glutathione peroxidase and superoxide dismutase were also reduced in cervical cancer compared to normal controls (P < 0.001). This reduction was more marked in late stages (III, IV) than in early stages (I, II) (P < 0.001). Glutathione was reduced more in poorly differentiated tumors (grade III) than in well and moderately differentiated ones (grade I, II) (P < 0.05). Levels of lipid peroxides were found to be significantly higher in malignant than in normal tissue samples and their levels were correlated with advanced clinical stage (P < 0.001). Our results suggest impaired antioxidant status in carcinoma of the cervix. This impairment is related to tumor progression.     

HepG2 细胞谷胱甘肽含量和谷胱甘肽转移酶活力的诱导

目的：建立一种具有较高ＧＳＨ含量和ＧＳＴ活力的肝细胞系。方法：将ＨｅｐＧ２细胞在０．１,０．３,０．５ｍｇ／Ｌ浓度的ＣＤＤＰ间歇作用下传代１２个月后得到三种稳定的ＣＤＤＰ耐药细胞系ＨｅｐＧ２／ＣＤＤＰ０．１,ＨｅｐＧ２／ＣＤＤＰ０．３,ＨｅｐＧ２／ＣＤＤＰ０．５细胞的ＧＳＨ含量和ＧＳＴ活力,结果用显著性ｔ检验方法作统计学处理。结果：诱导刺激后的子代ＨｅｐＧ２／ＣＤＤＰ０．１,ＨｅｐＧ２／ＣＤＤＰ０     

Breast cancer: Pretreatment drug resistance parameters (GSH-system, ATase, P-glycoprotein) in tumor tissue and their correlation with clinical and prognostic characteristics

Background: The identification of new factors predicting relapse,outcome and response to systemic therapy in breast cancer is warranted. Themeasurement of biological markers such as drug resistance parameters (DRPs),which are part of the phenotype of malignant cells and contribute toresistance to anti-cancer drugs may be a possibility, which may ultimatelylead to improvement of therapeutic results.Patients and methods: The level of glutathione (GSH), activities ofglutathione-S-transferase (GST), glutathione-peroxidase (GPx),06-alkylguanine-DNA-alkyltransferase (ATase), and P-glycoprotein (PGP) weremeasured in tumor and adjacent tumor free tissue samples from 89 consecutive,untreated females with breast cancer and correlated with clinical andprognostic factors. Early breast cancer (EBC) was diagnosed in 56 patients,22 patients had locally advanced (LABC) and 11 patients metastatic breastcancer.Results: All DRPs showed significantly higher expression in tumorthan in tumor free tissues. GPx was positively correlated with GST (R = 0.3, P = 0.0048) and with GSH (R = 0.5, P = 0.0001) in tumor as wellas in normal tissue. GST activity was significantly higher in EBC than in LABCor metastatic breast cancer ( P = 0.02). GSH level was significantlyhigher in grade 1 than in grade 2 or grade 3 tumors ( P = 0.01). Whenclinical characteristics were related to the level of DRP, high GSH wasassociated with age >60 years ( P = 0.01) in EBC, and with grade1–2 tumors ( P = 0.05) in LABC. No differences in OS were apparentbetween groups of high and low DRP-expression. However, the four-yearestimated disease-free survival of EBC tended to be higher in patients withhigh GST ( P = 0.10) and of LABC in patients with high GPx levels( P = 0.06).Conclusion: We conclude that high levels of DRP in tumor tissue ofbreast cancer patients are part of the initial phenotype of the malignantcells. Due to its high prevalence (83% in EBC, 100% in primarilymetastatic breast cancer), PGP did not add to prognostic information. Highlevels of GSH, GST and and GPx were associated with favorable clinicalcharacteristics and good prognosis, whereas low levels of GSH and GST activitywere associated with more aggressive or more advanced disease.     

15kg负重沙漠干热应激行军速度和时间对人体GSH和SOD的影响

目的　探讨沙漠干热负重应激行军人体ＧＳＨ 和ＳＯＤ 作用机制。方法　对７４ 名１５ ｋｇ 负重在沙漠干热环境以不同速度和时间行军战士和对照人群血浆的变化进行了研究。结果　１５ ｋｇ 负重,３－５ｋｍ／ｈ 和５ ｋｍ／ｈ 行军者ＧＳＨ 在应激的最初１ 小时内迅速上升,约１ 小时达到高峰,之后迅速下降;随着行军速度的增加,机体抗氧化作用所消耗的ＳＯＤ 量增加,血浆ＳＯＤ 浓度亦随之下降。结论　从行军时间来看,在应激的最初１ 小时内,因应激诱导的ＧＳＨ 的合成和ＳＯＤ 的量增加,故沙漠干热环境负荷应激行军以１５ ｋｇ、３－５ ｋｍ／ｈ 为宜。