Iron-mobilizing properties of the gadolinium-DTPA complex: clinical and experimental observations.

BACKGROUND: Gadolinium (Gd) magnetic resonance imaging (MRI) contrast agents are considered to be safe in patients with impaired renal function. Our study investigates a mechanism of severe iron intoxication with life-threatening serum iron levels in a haemodialysis patient following MRI with Gd-diethylenetriaminepentaacetic acid (Gd-DTPA) administration. His previous history was remarkable for multiple blood transfusions and biochemical evidence of iron overload. We hypothesized that Gd-DTPA may have an iron-mobilizing effect in specific conditions of iron overload combined with prolonged exposure to the agent. METHODS: For the in vitro study, Gd-DTPA was added to mice liver homogenate and iron metabolism parameters were measured after incubation in comparison with the same samples incubated with saline only. For the in vivo study, an experimental model of acute renal failure in iron-overloaded rats was designed. Previously iron-overloaded and normally fed rats underwent bilateral nephrectomy by renal pedicle ligation, followed by Gd-DTPA or saline injection. Iron and iron saturation levels were checked before and 24 h after Gd-DTPA or vehicle administration. RESULTS: Significant mobilization of iron from mice liver tissue homogenate in mixtures with Gd in vitro was seen in the control (saline) and in the experimental (Gd) groups (513+/-99.1 vs 1117.8+/-360.8 microg/dl, respectively; P<0.05). Administration of Gd-DTPA to iron-overloaded rats after renal pedicle ligation caused marked elevation of serum iron from baseline 143+/-3.4 to 570+/-8 microg/dl (P<0.0001). There were no changes of the named parameter, either in iron-overloaded anuric rats after saline injection or in normal diet uraemic animals, following Gd-DTPA administration. CONCLUSIONS: The combination of iron overload and lack of adequate clearance of Gd chelates may cause massive liberation of iron with dangerous elevation of free serum iron. It is highly recommended that after Gd contrast study, end-stage renal disease patients with probable iron overload should undergo prompt and intensive haemodialysis for prevention of this serious complication.     

RESEARCH ON A REAL-TIME CONTROL SYSTEM OF LOW POWER DISSIPATION FOR CONTINUOUS CYCLIC PERITONEAL DIALYSIS(CCPD) CYCLER

FOREWORDPeritonealdialysisrepresentssoluteandfluidexchangemainlybetweenperitonealcapillarybloodanddialysissolutionintheperitonealcavity'CombinedwithhemodialySisandrenaltransplantation,peritonealdialysisisusedmainlyforthetreatmentofrenalfailure,particularlyforchronicfailure'In1976,Prof'Popovichdevelopedcontinuousambulatoryperitonealdialysis(CAPD)basingontheconceptofcontinuousequilibrationdialysis('1'Fromthenon,peritonealdialysisfounditsclinicaluse'Continuouscyclicperitonealdialysis(CCPD…     

心血管外科术后急性肾功能衰竭的处理

目的：总结两组心血管外科术后急性肾功能衰竭病例的治疗经验，提出心血管外科术后急性肾功能衰竭的特点、早期诊断标准及处理原则。方法：１７例心血管外科术后急性肾功能衰竭病例，以入院先后分为两组。第１组８例，第２组９例。回顾第１组病例的急性肾功能衰竭的治疗经验，总结腹膜透析、血液透析和血液滤过的优缺点。在第２组病例治疗中，以急性肾功能衰竭的早期诊断为前题，早期开始腹膜透析。同时，强调综合治疗的重要性。结果：第１组病例均死亡。第２组病例，７例存活（７８％）。结论：心血管外科术后急性肾功能衰竭的早期诊断和早期肾功能替代疗法，是治疗成败的关键。腹膜透析简便易行，在急性肾功能衰竭的早期开始腹膜透析，可以收到良好效果，并以此作为心血管外科术后急性肾功能衰竭的首选肾功能替代疗法。     

Plasma kinetics of 125I-labelled amyloid P component in {beta}2M amyloidosis: A possible approach to quantitate disease activity

Dialysis amyloidosis is one of the most incapacitating complicationsof long-term dialysis treatment. Quantitative assessment ofamyloid deposition using radiolabelled tracers has been recentlyproposed but convincing evidence of its validity in uraemicpatients remains to be provided. We studied the plasma kineticsof i.v. administered ¹²⁵I-labelled serum amyloid P component(¹²⁵I-SAP) in 20 chronic haemodialysis patients compared withthose of nine healthy volunteers and three non-dialysed patientswith systemic amyloidosis. Plasma clearance of the tracer wasabnormal in 17 of 20 dialysis patients in whom plasma radioactivitydeclined in a bi-exponential mode, in contrast to the single-exponentialslope observed in all healthy controls. ¹²⁵I-SAP plasma half-lifeof the second component, probably reflecting metabolic clearance,was significantly prolonged in these dialysis patients comparedwith the healthy controls (35.3 versus 24.6 h, P<0.001).Among the long-term haemodialysis patients the calculated extravasculardistribution of ¹²⁵I-SAP was significantly greater in thosewith severe arthropathy than in asymptomatic patients. Thesefindings demonstrate for the first time that SAP clearance isdisturbed in haemodialysis patients due to both failing renalelimination and retention in extravascular sites. The extravasculardiffusion is greatly enhanced in patients with clinical evidenceof amyloidosis. Therefore the study of plasma ¹²⁵I-SAP kineticspromises to be a valuable tool to quantitate the extent of amyloidosis.     

Aspergillus peritonitis in peritoneal dialysis: case report and a review of the literature

Aspergillus peritonitis is a rare complication of continuousambulatory peritoneal dialysis. The case is described of a 68-year-oldman in whom Aspergillus fumigatus was isolated from the peritonealdialysate after recurrent peritonitis with Gram-negative rodsin association with diverticulosis. Treatment consisting ofremoval of the catheter and intravenous administration of amphotericinB followed by oral itraconazole was successful. A review of the sparse literature (12 cases) displays uncertaintiesregarding diagnostic awareness, culture diagnosis, and therapeuticmanagement. Next to institution of appropriate antifungal therapy,early removal the peritoneal dialysis catheter is recommended,as delayed removal of the catheter appears to be associatedwith increased mortality and morbidity.     

新型阳离子(苯乙烯—丙烯酰胺)共聚物的研究 Ⅱ.阳离子(苯乙烯——丙烯酰胺)共聚物与染料的相互作用

以P(St-Am·MG)对染料活性艳红(X-3B)溶液进行絮凝试验,考察了高聚物剂量及外加盐对絮凝效果的影响,并与无疏水基团的阳离子聚丙烯酰胺PAm·MG的絮凝能力进行了比较。发现絮凝体系无外加盐时,高聚物与染料的作用主要是通过静电力;有外加盐时,高聚物的电荷受到屏蔽,高分子链卷曲,PAm·MG的絮凝效果受到较大影响。而P(St-Am·MG)与X-3B之间存在疏水相互作用,受影响较小,此时P(St-Am·MG)的絮凝性能优于PAm·MG。用平衡渗析法研究了不同温度时甲醇和脲存在下P(St-Am·MG)与X-3B相互作用的热力学。证明了它们之间确实存在疏水相互作用。     

Circulating 1,25-Dihydroxycholecalciferol After Intravenous Injections of l{alpha}-Hydroxycholecalciferol in Patients on Regular Haemodialysis

The formation of 1.25-dihydroxycholecalciferol (1.25-(OH)₂D₃after single intravenous injections of 1-hydroxycholecalciferol(1-OHD₃) was examined in four patients with chronic renal failureon regular haemodialysis. Following 1–3µg 1-OHD₃administered at weekly intervals, 1.25-(OH)₂D₃ appeared in thecirculation within 1 h, and peak concentrations were reachedbetween 2 h and 5 h. By 8 h serum 1.25-(OH)₂D₃ concentrationshad started declining and by 44 h they had returned to baselineafter 1µg 1-OHD₃ but they were still above basal after2 and 3 µg by an average of 30 pmol/l. One week afterinjections, concentrations were back to basal in all patientsstudied. The serum 1,25-(OH)₂D₃ dose response to injected la-OHDwas linear, indicating ample capacity of the liver 25-hydroxylaseto further hydroxylate 1-OHD. However, examination of the individualresponses revealed lower increments in serum 1.25-(OH)₃ concentrationsin the patients with the highest basal serum 25-hydroxyvitaminD concen trations. Intravenous 1-OHD₃ may be useful in the furtherstudy of the interactions between 1.25-(OH)₂₃ calcium and PTHin chronic renal failure, as well as of the hepatic metabolismof vitamin D.     

Characteristics of β-endorphin-induced histamine release from rat serosal mast cells Comparison with neurotensin,dynorphin and compound 48/80

Summary Rat peritoneal mast cells were exposed to the neurohormone and basic opioid peptide -endorphin. -Endorphin induced a dose-dependent release of histamine from the mast cells. A significant histamine release was found at 5 mol/l of -endorphin and maximal release (35% of total) at 20 mol/l. The histamine release process was very rapid and terminated within 30 s at 37°C, and in this sense is very similar to the histamine release induced by compound 48/80 or neurotensin. The histamine release was temperature-dependent showing an optimum release around 30°C, and it was independent of available extracellular calcium, but was inhibited in the presence of high extracellular calcium concentrations. Naloxone, only in very high concentrations (10 mmol/l), inhibited the release, and the very same concentration also inhibited the neurotensin — as well as the compound 48/80-induced histamine release. Cromoglycate and benzalkoniumchloride, a 48/80 antagonist, both produced a progressive dose-dependent inhibition of -endorphin-, neurotensin- as well as compound 48/80-induced histamine release. Taken together, the findings indicate that the opioid peptide -endorphin induces a selective, energy-dependent release of histamine from peritoneal rat mast cells. The pattern of release has much in common with that of compound 48/80 and other basic peptides, such as neurotensin and substance P. In addition this pattern of release is similar to that induced by dynorphin. Send offprint requests to Anita Sydbom at the above address     

NLR和PLR对腹膜透析患者腹膜炎的预测价值

目的:通过分析影响腹膜透析患者腹膜炎患病特征,探究血清中性粒细胞/淋巴细胞比值（NLR）和血小板/淋巴细胞比值（PLR）对腹膜透析患者腹膜炎的预测价值。方法:纳入2020年1月—2021年10月首次接受腹膜透析患者共203例为研究对象,随访6个月,诊断腹膜炎41例。比较腹膜炎组与无腹膜炎组性别、年龄、体重指数、原发肾脏疾病、基础疾病、吸烟、透析龄、肺炎和肠道感染情况,实验室指标包括白细胞计数、中性粒细胞计数、淋巴细胞计数、血小板计数、血红蛋白、血肌酐、血钾、血钙、白蛋白、总胆固醇、低密度脂蛋白、空腹血糖、C反应蛋白（CRP）和降钙素原（PCT）,计算NLR、PLR和估算的肾小球滤过率（eGFR）。结果:41例患者发生1次腹膜炎34例,两次及以上7例,发生时间为透析后1~6个月,中位时间3.5个月。病原学检查发现,41例患者革兰阳性菌（G+）感染22例,革兰阴性菌（G-）感染17例,真菌2例。单因素比较发现,腹膜炎组比无腹膜炎组年龄增加,糖尿病和肠道感染增多,透析龄延长,白细胞计数、中性粒细胞计数、血小板计数、血肌酐、总胆固醇、空腹血糖、CRP和PCT、NLR和PLR水平升高,而白蛋白降低,差异均有统计学意义（χ2＝12.433～5.968;t＝4.526～22.325,均P＜0.05）。多因素Logistic回归分析显示,肠道感染（OR=3.652,95%CI:2.485~5.023,P＜0.001）、透析龄（OR=5.524,95%CI:3.896~7.215,P＜0.001）、高NLR（OR=4.425,95%CI:2.967~5.632,P＜0.001）和高PLR（OR=4.021,95%CI:2.536~5.021,P＜0.001）是腹膜透析患者发生腹膜炎的独立危险因素。受试者工作特征（ROC）曲线显示,NLR和PLR预测腹膜炎的曲线下面积（AUC）分别为0.852和0.813,临界值分别为2.8和106.7,敏感性分别为85.6%和80.7%,特异性分别为77.9%和86.4%。结论:腹膜透析有较高的腹膜炎发生率,发生峰值在3.5个月,以G+或G-感染为主,肠道感染、透析龄延长、高NLR和高PLR水平是腹膜炎的独立危险因素,血清NLR和PLR监测对早期预测腹膜炎有重要的应用潜力。     

Personality and patient adherence: Correlates of the five-factor model in renal dialysis

The five-factor taxonomy of personality traits has received increasing attention in the literature regarding personality correlates of health outcomes and behaviors. We examined the association of the five NEO Five-Factor Inventory dimensions to medical regimen adherence in a sample of 72 renal dialysis patients. Results indicated that Conscientiousness (Dimension III) is a five-factor trait significantly associated with adherence to the medication regimen. No other NEO-FFI dimension was significantly associated with patient adherence.