Effect of lactate and bicarbonate on human peritoneal mesothelial cells, fibroblasts and vascular endothelial cells, and the role of basic fibroblast growth factor.

BACKGROUND: In patients on long-term continuous ambulatory peritoneal dialysis (CAPD), peritoneal dysfunction may occur due to loss of peritoneal mesothelial cells, peritoneal fibrosis and neovascularization. Lactate, long used as a buffer in peritoneal dialysates, has been substituted by bicarbonate in recent years. However, their effects on the peritoneum of CAPD patients are unknown. This study investigated the influence of lactate and bicarbonate on peritoneal dysfunction in CAPD patients. METHODS: The mitochondrial activity of human peritoneal mesothelial cells (HPMCs) and their expression of basic fibroblast growth factor (bFGF) were studied after culture under various conditions. We also assessed the mitochondrial-activating effect of the supernatant of those cultures on human peritoneal fibroblasts (HPFBs) and human umbilical vein endothelial cells (HUVECs) and the effect of recombinant human bFGF on the mitochondrial activity of HPFBs and HUVECs. We used the WST-1 assay to determine mitochondrial activity in HPMC. RESULTS: At pH 7.4, the mitochondrial activity of HPMCs was lowest in a medium containing 40 mM (Lac), intermediate in a lactate (15 mM) plus bicarbonate (25 mM) medium (Lac/Bic), and highest in a 40 mM bicarbonate medium (Bic). In culture supernatant, the increase of bFGF was: Lac > Lac/Bic > Bic. Mitochondrial activation of HPFBs and HUVECs was stimulated by HPMC culture supernatants in the following decreasing order: Lac > Lac/Bic > Bic. The effects of these supernatants were suppressed by a bFGF-neutralizing antibody, while recombinant bFGF caused concentration-dependent mitochondrial activation in HPFBs and HUVECs. CONCLUSIONS: The role of bFGF in peritoneal fibrosis and neovascularization may be important. A bicarbonate-containing medium is better than a lactate-containing medium for preserving cell viability in HPMCs and preventing bFGF expression by these cells.     

Oxidative stress induced by iron released from transferrin in low pH peritoneal dialysis solution

Background. Transferrin binds extracellular iron and protectstissues from iron-induced oxidative stress. The binding of ironand transferrin is pH dependent and conventional peritonealdialysis (PD) solutions have unphysiologically low pH values.Herein, we investigated whether conventional PD solution releasesiron from transferrin and if the released iron causes oxidativestress. Methods. Effects of PD solutions on iron binding to transferrinwere examined with purified human transferrin and transferrinin dialysates drained from PD patients. Oxidative stress inducedby iron released from transferrin was evaluated in terms ofthe formation of thiobarbituric acid reactive substance (TBARS)and protein carbonylation in the human red blood cell (RBC)membrane. The iron deposition in peritoneal tissue from PD patientswas evaluated by Perls' staining with diaminobenzidine intensification. Results. Low pH PD solution released iron from transferrin.This iron release occurred within 1 min. Iron release was notobserved in neutralized PD solution. Iron released from transferrinin low pH PD solution increased TBARS formation and proteincarbonylation in the human RBC membrane. Iron deposition, whichis prominent in the fibrotic area facing the peritoneal cavity,was observed in the peritoneum of PD patients. Conclusions. Iron released from transferrin in low pH PD solutioncan produce oxidative stress in the peritoneum of a PD patient.Neutralizing PD solution can avoid this problem. Iron depositionin the peritoneum may participate in the pathogenesis of peritonealfibrosis in PD patients.     

腹膜透析对重症急性胰腺炎大鼠肾损害的保护作用

目的探讨腹膜透析(PD)对重症急性胰腺炎(SAP)大鼠肾损害的保护作用并探讨可能的机制。方法SD大鼠72只随机分为对照组(24只)、SAP组(24只)和PD组(24只),观察各组血清前列腺素(TXA2/6-K-PGF1a)及内皮素(ET-1)水平和肾脏病理变化。结果SAP组和PD组血清ET-1水平较对照组明显升高,同时段SAP组与PD组比较,PD组水平明显降低;SAP组和PD组血清TXA2/6-K-PGF1a水平较对照组明显升高,同时段SAP组与PD组比较,PD组水平明显降低。PD组大鼠肾病理损害较SAP组明显减轻。结论血液流变异常参与SAP肾损害的发生,早期进行PD治疗对SAP大鼠肾有保护作用,其可能的机制是改善微循环、清除炎症介质等。     

An experience of renal replacement therapy in a combined neonatal and paediatric intensive care unit of Hong Kong

Intensive care services are expensive. The experience of developing a combined paediatric and neonatal intensive care unit (ICU) in a regional hospital is reported with reference to the provision of renal support for the critically ill patients. The combined unit is staffed by a team of paediatric intensivists, each of whom has special interest in a subspecialty, including cardiology, respiratory medicine, nephrology and neonatology. In the past 7 years, renal replacement therapy (peritoneal dialysis and haemofiltration) was provided to 40 patients, with comparable mortality and complication rates to other reports. This arrangement has been feasible and might be more efficient than running separate paediatric and neonatal ICUs or combining the paediatric ICU with the adult ICU.     

Chronic peritoneal dialysis in paediatrics: Experience of a national registry

The results of the first 3 year' collaboration of the Italian Registry of Paediatric Chronic Peritoneal Dialysis (CPD) (1986–1988) are presented. This Registry acquired data on the majority of the paediatric patients treated with CPD in Italy, thus providing a national picture in a field where few nationwide surveys are available. Patients of less than 15 years of age at the start of dialysis were enrolled and clinical data collected until the age of 19 years. The number of nephrological paediatric centres participating in the Registry increased from 7 in 1986 to 11 in 1988. The total number of patients on CPD was 70 and the percentage of dialysed children treated with CPD ranged from 40.2% to 43.6%. Data on 89 peritoneal catheters were collected: during 1417 dialysis-months 70 catheter-related complications were observed (1:20.8 dialysis-months); actuarial catheter survival was 92.7% at 6 months, 84.8% at 1 year and 68.8% at 2 years. The incidence of peritonitis changed from 1 episode every 10.9 patient-months in 1986 to 1 every 19.8 in 1988. Abdominal hernias were the other main clinical complication observed. The survival of patients was 92.5% at 3 years, while the technique survival at the same time was 84%.     

胃癌腹腔脱落细胞检查及临床意义

腹膜转移是胃癌常见的转移形式。为在肉眼可见转移前发现亚临床的转移现象,自1981年3月至1982年4月,我们共对胃癌病人142例进行了腹腔脱落细胞检查及临床随诊,发现有腹腔脱落细胞阳性者76例(53.5％)。5年随诊结果发现,腹腔脱落细胞阳性者无一例生存>3年;而腹腔脱落细胞阴性的66例中生存5年者有11例。可见,腹腔脱落细胞检查,对胃癌的诊断,治疗和预后判断有一定价值。     

MACS检测胃癌腹腔冲洗液游离癌细胞的研究

目的 探讨胃癌腹腔微转移情况的检测方法及意义。方法 手术中切除肿瘤前收集腹腔冲洗液，采用磁激活细胞分离术（MACS）对不同病理分期胃癌患者腹腔冲洗液中癌细胞进行富集并检测。分别标记带磁珠的细胞角蛋白（CK）抗体，经磁柱富集CK^＋上皮细胞，用流式细胞仪检测其含量，并比较胃癌组与胃平滑肌瘤组（对照组）以及胃癌不同分期之间、磁富集前后CK^＋上皮细胞含量的差异。结果 在未经MACS富集的标本中较少发现CK^＋ CD45^-细胞；在富集后的标本中其含量在胃癌组与对照组有显著差异（41／50，1／10，P〈0．001）；pTNMⅠ～Ⅱ期与Ⅲ～Ⅳ期之间（0．67％，3．42％，P〈0．001）差异有非常显著性。结论 MACS能有效地富集上皮来源细胞，提高上皮源细胞的检出率，并能反映腹腔游离癌细胞数量；上皮细胞数量与胃癌的存在及临床病理分期有关，其有利于判断肿瘤转移和预后并指导治疗。     

腹膜透析患者应对压力的方式与焦虑抑郁情绪的关系

目的：探讨应对压力的方式与腹膜透析患者的焦虑抑郁情绪的关系。方法：采用自填式结构问卷，对81例腹膜透析患者进行调查，了解患者的一般情况和患者应对措施，同时用综合性医院焦虑和抑郁情绪量表测量他们的焦虑与抑郁情绪。结果：控制年龄等因素后的等级回归分析表明：使用“面对”和“自我缓解”应对方式显著降低患者的焦虑情绪，采用“屈从”应对方式增加焦虑的发生；文化程度高的患者采用逃避应对方式则大大增加焦虑情绪的程度，女性和经济收入高者采用面对应对方式可以大大降低焦虑情绪的发生；“自我缓解”应对方式显著降低患者抑郁情绪发生的可能性。结论：不同的应对方式对腹膜透析患者的焦虑抑郁情绪存在差异。     

肾衰合剂对维持性腹膜透析患者残余肾功能的影响

目的：观察肾衰舍剂对连续不卧床腹膜透析（CAPD）患者残余肾功能的影响，探讨中药治疗对CAPD患者残余肾功能的保护作用及其机制。方法：将56例脾肾气（阳）虚型的CAPD患者随机分为常规腹膜透析对照组，及加服中药肾衰合剂治疗组。治疗6个月，比较残余肾KT／V、残余肾CCr的变化及下降速率。结果：在维持总体透析效能的前提下，治疗组残余肾KT／V、残余肾CCr下降速度较对照组明显缓慢。结论：肾衰合荆能有效延缓PD患者的RRF的下降。     

Acute Renal Failure after Lung Transplantation: Incidence, Predictors and Impact on Perioperative Morbidity and Mortality

The incidence, predictors and clinical significance of acute renal failure (ARF) after lung transplantation are not well described. We retrospectively collected data on 296 patients transplanted at our center between April 1992 and December 2000; follow-up was extended until December 2002. Patients were initially divided into two groups: ARF (doubling of baseline creatinine within 2 weeks after surgery) and NoARF. The ARF group was subdivided into ARFD (dialyzed) and ARFnD (not dialyzed). The incidence of ARF was 56% (166/296), but most cases were ARFnD (n = 143). Independent predictors of ARFD (n = 23) were: baseline GFR (OR 0.98, CI 0.96-0.99, p = 0.012), pulmonary diagnosis other than COPD (OR 6.80, CI 1.5-30.89, p = 0.013), mechanical ventilation > 1 d (OR 6.16, CI 1.70-22.24, p = 0.006) and parenteral amphotericin B use (OR 3.04, CI 1.03-8.98, p = 0.045). Both ARFnD and ARFD were associated with longer duration of mechanical ventilation, increased hospital stay and increased early mortality. One-year patient survival was 92.3%, 81.8% and 21.7% in the NoARF, ARFnD and ARFD groups, respectively (p < 0.0001). After controlling for important covariates, ARFD remained associated with an increased hazard of dying (HR 6.77, CI 4.00-11.44, p < 0.0001). In conclusion, ARF occurs commonly after lung transplantation and affects important clinical outcomes, especially when dialysis is required.