卡介苗HSP70基因转染对小鼠淋巴细胞白血病细胞免疫原性的影响

目的探讨卡介苗热休克蛋白70(BCG HSP70)基因转染对小鼠淋巴细胞白血病细胞(L1210)致瘤性及免疫原性的影响。方法利用脂质体2000将BCG HSP70基因转入小鼠淋巴细胞白血病细胞系L1210表面,获得高表达HSP70分子的L1210-HSP70细胞,作为肿瘤疫苗分别对裸鼠及同系小鼠致瘤性、瘤苗对荷瘤小鼠的免疫治疗作用以及瘤苗对L1210细胞攻击的免疫保护作用进行研究。结果 BCG HSP70成功表达在转染后的L1210细胞表面,并具有与野生型细胞同样的致瘤性。同系小鼠DBA/2皮下接种L1210-HSP70细胞后肿瘤生长缓慢或不成瘤;相对于L1210组和L1210-neo组,生存期明显延长,小鼠脾淋巴细胞中针对L1210细胞的特异性T细胞数量明显增加,差异有统计学意义(P0.05);瘤体病理切片示彻底凝固性坏死,周边可见淋巴样细胞,免疫组化检测示大量CD8+T淋巴细胞浸润。L1210-HSP70细胞瘤苗具有对荷瘤小鼠的免疫治疗作用,以及抗肿瘤攻击的免疫保护作用,均表现为肿瘤出瘤时间明显延长,生长受到显著抑制,瘤体平均直径明显减小;荷瘤小鼠生存时间明显长于L1210组、L1210-neo组和PBS组,差异有统计学意义(P0.05)。结论BCG HSP70基因转染能有效增强肿瘤细胞的免疫原性,激活特异性T细胞,降低肿瘤细胞的致瘤性;并具有提高宿主抗瘤免疫作用。     

Mechanisms of periodic breathing during exercise in patients with chronic heart failure

BACKGROUND: Periodic breathing (PB) in heart failure (HF) is attributed to many factors, including low cardiac output delaying the time it takes pulmonary venous blood to reach the central and peripheral chemoreceptors, low lung volume, lung congestion, augmented chemoreceptor sensitivity, and the narrow difference between eupneic carbon dioxide tension and apneic/hypoventilatory threshold. METHODS AND RESULTS: We measured expired gases, ventilation, amplitude, and duration of PB in 23 patients with PB during progressive exercise tests done with 0 mL, 250 mL, or 500 mL of added dead space. Periodicity of PB remained constant despite heart rate, oxygen consumption, and minute ventilation increasing. Within each PB cycle, starting from the beginning of exercise, the largest (peak) tidal volume approached maximum observed tidal volume, while the smallest (nadir) tidal volume increased as exercise power output increased. PB ceased when nadir tidal volume reached peak tidal volume. End-tidal carbon dioxide increased with added dead space, and PB ceased progressively earlier during the exercise done with increased dead space. CONCLUSION: Circulatory delay does not contribute to the PB observed in exercising HF patients. The pattern of gradually increasing nadir tidal volume during exercise and the effect of dead space on both PB ceasing and end-tidal carbon dioxide suggest that low tidal volume and carbon dioxide apnea threshold are important contributors to PB that occurs during exercise in HF.     

Outcomes associated with combined antiplatelet and anticoagulant therapy

BACKGROUND: The use of antiplatelet therapy in combination with oral anticoagulants remains controversial. The objective of this study was to estimate and compare the incidence of adverse and coronary event rates between patients receiving warfarin monotherapy or warfarin and antiplatelet combination therapy. METHODS: This was a retrospective, longitudinal, pharmacoepidemiologic analysis. Adult patients receiving warfarin managed by an anticoagulation service who had documented the use of antiplatelet agents (eg, aspirin, clopidogrel, and/or dipyridamole) [ie, the combination-therapy cohort] or their nonuse (ie, the monotherapy cohort) were identified as of September 30, 2005. Utilizing integrated, electronic medical records, anticoagulation-related adverse events (eg, death, hemorrhage, or thrombosis) and coronary events were identified during a 6-month follow-up period (October 2005 through March 2006). The proportions of events were compared between cohorts. Independent associations between the cohorts and the outcomes were assessed with adjustment for potential confounding factors. RESULTS: Data from 2,560 patients in the monotherapy cohort and 1,623 patients in the combination-therapy cohort were analyzed. Patients in the combination-therapy cohort were more likely to have had anticoagulation-related hemorrhages (4.2% vs 2.0%, respectively; unadjusted p < 0.001) and coronary events (0.9% vs 0.3%, respectively; p = 0.009), but not death (0.1% vs 0.2%, respectively; unadjusted p = 0.186) or thrombotic events (0.3% vs 0.4%, respectively; unadjusted p = 0.812). With adjustment, combined warfarin and antiplatelet use was independently associated with hemorrhagic events (odds ratio [OR], 2.75; 95% confidence interval [CI], 1.44 to 5.28), but not with coronary events (OR, 0.99; 95% CI, 0.37 to 2.62). CONCLUSIONS: At the population level, the hemorrhagic risk associated with warfarin therapy combined with antiplatelet therapy appears to outweigh the benefits. These findings suggest that clinicians should carefully consider the risks and benefits when recommending combined antiplatelet therapy for patients receiving warfarin who do not meet the evidence-based criteria for such therapy.     

Risk factors for ARDS in patients receiving mechanical ventilation for > 48 h

BACKGROUND: Low tidal volume (Vt) ventilation for ARDS is a well-accepted concept. However, controversy persists regarding the optimal ventilator settings for patients without ARDS receiving mechanical ventilation. This study tested the hypothesis that ventilator settings influence the development of new ARDS. METHODS: Retrospective analysis of patients from the Multi Parameter Intelligent Monitoring of Intensive Care-II project database who received mechanical ventilation for > or = 48 h between 2001 and 2005. RESULTS: A total of 2,583 patients required > 48 h of ventilation. Of 789 patients who did not have ARDS at hospital admission, ARDS developed in 152 patients (19%). Univariate analysis revealed high peak inspiratory pressure (odds ratio [OR], 1.53 per SD; 95% confidence interval [CI], 1.28 to 1.84), increasing positive end-expiratory pressure (OR, 1.35 per SD; 95% CI, 1.15 to 1.58), and Vt (OR, 1.36 per SD; 95% CI, 1.12 to 1.64) to be significant risk factors. Major nonventilator risk factors for ARDS included sepsis, low pH, elevated lactate, low albumin, transfusion of packed RBCs, transfusion of plasma, high net fluid balance, and low respiratory compliance. Multivariable logistic regression showed that peak pressure (OR, 1.31 per SD; 95% CI, 1.08 to 1.59), high net fluid balance (OR, 1.3 per SD; 95% CI, 1.09 to 1.56), transfusion of plasma (OR, 1.26 per SD; 95% CI, 1.07 to 1.49), sepsis (OR, 1.57; 95% CI, 1.00 to 2.45), and Vt (OR, 1.29 per SD; 95% CI, 1.02 to 1.52) were significantly associated with the development of ARDS. CONCLUSIONS: The associations between the development of ARDS and clinical interventions, including high airway pressures, high Vt, positive fluid balance, and transfusion of blood products, suggests that ARDS may be a preventable complication in some cases.     

Tumor growth-promoting cellular host response during liver atrophy after portal occlusion.

BACKGROUND/AIMS: Clinical observations suggest cancer progression after preoperative segmental portal vein occlusion, a procedure to prevent liver failure after major hepatic resections. The aim of this study was to determine whether portal occlusion induces host reactions which promote cancer invasion and angiogenesis. METHODS: The rat model of portal branch ligation (PBL) was compared with partial hepatectomy (PH) and sham operation (SO) and evaluated for the expression of heat shock protein-70 (hsp70), heme oxygenase-1 (hmox1), early growth response gene-1 (Egr-1) and urokinase-type plasminogen activator (uPA), its inhibitor (PAI-1) and receptor (uPAR). RESULTS: Portal deprivation after PBL was associated with a regression of liver tissue to 25% of its original mass within 8 days with only modest fibrotic changes. During the progression of atrophy, there were significant inductions of hsp70-, hmox1- and Egr-1-mRNA in comparison with regenerating liver tissue. PAI-1-specific mRNA was transiently elevated at 3 - 48 h after PBL in the atrophying lobes, whereas uPA and uPAR were unaffected in comparison with PH or SO. CONCLUSION: Hepatic atrophy caused by PBL is associated with increased expression of genes known to promote tumor growth. These host events represent a possible explanation for the tumor progression after portal occlusion and require further evaluation.     

Accuracy of semiquantitative immunoenzymatic methods in quantitation of anti-topoisomerase I (Scl-70) antibodies

Reports of a possible correlation between anti-Scl-70 antibody concentration and clinical manifestations in systemic sclerosis patients have recently appeared in the scientific literature. The goal of our study was to evaluate, by means of a multicenter study, the analytical reliability of immunoassay systems in the quantitative measurement of Scl-70 antibodies. Three blind samples (H, M, L) at different anti-Scl-70 antibody concentrations, and a low concentration antibody serum (LPC) used as a common calibrator, were sent three times in a 6-month time span to 39 Italian clinical laboratories. Each laboratory was asked to calculate dosages following the enzyme-linked immunosorbent assay (ELISA) method they used and report the optical density values of each sample (ODs), of the cutoff serum provided by the manufacturer of the kit used (ODco) and of LPC (OD_LPC). The overall analytical imprecision (between methods and between laboratories) of the three different determinations of the values respectively expressed in ODs, ODs/ODco and ODs/OD_LPCratio was 47.1, 52.8 and 34.0% for sample H, 56.2, 47.4% and 34% for sample M and 84.6, 86.0 and 86.6% for sample L. The average intra-method analytical imprecision was, respectively, 20.7, 29.8 and 18.6% for sample H, 24.6, 26.5 and 19.3% for sample M, and 30.6, 28.1 and 20.2% for sample L. The commercial ELISA methods currently used to determine the presence of anti-Scl-70 autoantibodies show considerable differences in the quantitative determination. The best results for reproducibility analyses have been obtained when the values were expressed as a ratio between the ODs of the sample and of the common calibrator (ODs/OD_LPC). Forward-looking clinical studies that can clarify the usefulness of quantitative determination of anti-Scl-70 antibodies in the monitoring of diffuse scleroderma patients can be performed only when standard serum with a known antibody concentration and calibration curves for quantitative ELISA measurements are made available.     

Ku70与hTERT在胃癌组织中的表达及其意义

目的探讨Ku70和人端粒酶逆转录酶(h TERT)蛋白表达与胃癌发生发展的关系及两者之间的联系。方法应用免疫组织化学方法检测Ku70和h TERT蛋白在10例正常胃黏膜、15例胃癌前病变黏膜和20例胃癌组织中的表达。结果 Ku70蛋白阳性表达定位于正常胃黏膜和胃癌组织的细胞核,胃癌前病变黏膜的细胞浆,其阳性表达率分别为90%、100%和80%;h TERT蛋白在正常胃黏膜几乎不表达,在胃癌前病变黏膜和胃癌组织中均定位于细胞浆,其阳性表达率分别为30%、100%和100%。胃癌组织中Ku70和h TERT蛋白的表达强度明显高于正常胃黏膜和胃癌前病变黏膜。Ku70和h TERT蛋白的表达显著相关。结论 Ku70和h TERT蛋白可能与胃癌的发生发展过程相关。     

罗格列酮对人多囊肾囊肿衬里上皮细胞增殖的抑制作用

Objective To investigate the antiproliferative effect of rosiglitazone, a thiazolidinedione (TZD) on autosomal dominant polycystic kidney disease (ADPKD) cystic lining epithelial cells and to explore the underlying molecular mechanism. Methods ADPKD cysticlining immortalized epithelial (WT9-12) cells were stimulated by rosiglitazone with different concentrations. After treatment, MTT method was performed to detect the level of proliferation; flow cytometry was used to determine the cell cycle distribution and the apoptosis rate. Western blotting was used to detect the protein expressions of mTOR, p70S6K, 4E-Bp1, PPARγ PPARγ siRNA was transfected into WT9-12 cells to knock down the expression of PPARγ Results Treatment of WT9-12 cells with rosiglitazone resulted in a dose-dependent and time-dependent strong inhibition of cell proliferation, an accumulation of cells in the G0/G1 phase (rosiglitazone 50 μmol/L 65.43%,rosiglitazone 100 μmol/L 64.02%, control 49.65% ) and 6% apoptosis at high concentration (rosiglitazone 200 μmol/L). Rosiglitazone reduced the phosphorylation of p70S6K in a dosedependent and time-dependent manner. The levels of phosphorylated mTOR and 4E-Bp1, the latter being a downstream substrate of mTOR related mRNA translation initiation, were not changed by rosiglitazone. Cells were pre-incubated with GW9662, a PPARγ antagonist, before the treatment with rosiglitazone, the inhibition of p70S6 kinase phosphorylation by rosiglitazone was partially prevented by GW9662 (P＜0.01). Then PPARγ siRNA was transfected into WT9-12 cells, in contrast to untransfected control or cells transfected with an irrelevant siRNA, rosiglitazone did not cause an obvious inhibition of p70S6 kinase phosphorylation in PPARγ knock-down.Conclusion Rosiglitazone inhibits the proliferation of ADPKD cystic lining epithelial cells, and down-regulates p70S6 kinase phosphorylation through mTOR-independent and PPARγ-dependent signal pathway.