Activation of L-arginine transport in undialysed chronic renal failure and continuous ambulatory peritoneal dialysis patients

1. Treatment with haemodialysis and continuous ambulatory peritoneal dialysis (CAPD) presents different pathophysiological profiles and it has been suggested that clinical outcome in chronic renal failure may depend on the mode of dialysis. The transport of L-arginine, a precursor of nitric oxide, into blood cells is increased in uraemic patients on haemodialysis. The present study was designed to investigate L-arginine transport into red blood cells (RBC) in uraemic patients not yet on dialysis and on CAPD therapy. 2. Eleven uraemic patients not yet on dialysis and 17 on CAPD were included in the study. L-Arginine transport into RBC and plasma and RBC amino acid profiles were analysed in these sets of patients. 3. L-Arginine transport via system y(+), but not y(+)L, into RBC, was significantly increased in undialysed uraemic patients (459 +/- 40 micromol/L per cell per h) and CAPD patients (539 +/- 61 micromol/L per cell per h) compared with controls (251 +/- 39 micromol/L per cell per h). High-pressure liquid chromatography measurements demonstrated low levels of plasma L-arginine in uraemic patients both on CAPD (54 +/- 3 micromol/L) and not yet on dialysis (80 +/- 6 micromol/L) compared with control subjects (146 +/- 14 micromol/L). 4. Our findings provide the first evidence that uraemic patients not yet on dialysis and on CAPD present with an activation of L-arginine transport via system y(+) into RBC associated with reduced plasma levels of L-arginine.     

电视胸腔镜行心包部分切除治疗急性渗出性心包炎

目的:探讨电视胸腔镜行心包部分切除治疗急性渗出性心包炎的效果.方法:回顾性分析我科2002-08～2005-12手术治疗78例急性渗出性心包炎的临床资料,其中胸腔镜手术组23例(治疗组),左侧开胸手术组38例(对照组1),剑突下心包开窗引流手术组17例(对照组2).结果:治疗组在手术时间、出血量、术后镇痛时间、术后引流量及引流时间、住院时间与对照组1比,差异均有显著性(P＜0.01);而晚期并发症复发性心包积液和缩窄性心包炎的发生率,两者比较差异无显著性(P＞0.05).对照组2远期并发症发生率均明显高于治疗组和对照组1,差异有显著性(P＜0.05; P＜0.01).结论: 电视胸腔镜行心包部分切除术具有创伤小、恢复快等优点,同时其远期并发症发生率低、疗效好,是目前治疗急性渗出性心包炎的理想方法,值得推广应用.     

Diagnosis and treatment of acute cardiac tamponade by the subxiphoid approach

Emergency cardiac surgery has been performed on 18 cases of acute cardiac tamponade whose etiologies were as follows: 11 cases of metastatic carcinoma, four cases of idiopathic pericarditis and three with other causes. In most cases, the chief complaint was dyspnea. In many cases, the cardiac silhouette of frontal chest X-ray films showed the shape of a water-filled ice-bag placed on a table. The electrocardiogram showed a low voltage and a flat T-wave in approximately half of the patients. In cases of an echo-free space 1 cm or larger on the M-mode echocardiogram, the average amount of pericardial fluid drained was 850 ml and in those in which the space was less than 1 cm, the average drained was 557 ml. The CT values were 9-40 for patients with malignant pericardial effusion and 20-22 for cases of idiopathic pericarditis. In general, pericardiocentesis was performed in almost all the patients with acute tamponade, but if the drainage was inadequate, the subxiphoid pericardial window procedure was performed under local anesthesia. Surgical invasion in this technique was minimal and the operative results proved effective. For the operation, we resected a 2 X 2 cm pericardial segment. Since two of the patients with malignant pericardial effusion developed postoperative reaccumulation, resection of a 4 X 4 cm segment in the future has been contemplated.     

Characterisation and comparison of health-related quality of life for patients with renal failure

OBJECTIVE: The objective of this study was to assess the health related quality of life (HRQOL) in patients with kidney failure who had received renal transplants compared to those receiving haemodialysis, peritoneal dialysis or were waiting to start dialysis. RESEARCH DESIGN AND METHODS: The study was conducted at the University Hospital of Wales, Cardiff. HRQOL was measured using the EQ-5D, SF-36 and the Kidney Disease Quality of life questionnaire (KDQOL). Patients with kidney failure were identified from the renal unit departmental database and were surveyed by postal questionnaire or during their treatment. RESULTS: Of 1251 people surveyed, 416 valid returns were received, a response rate of 33%. For renal transplant patients the mean EQ-5Dindex was 0.712 (SD 0.272), significantly higher than those in the other treatment groups (haemodialysis mean = 0.443 (SD 317), p < 0.001; peritoneal dialysis mean = 0.569 (SD 329), p < 0.001). This difference remained after controlling for age and co-morbidity. With the exception of pain, the SF-36 showed significantly higher scores across all domains for transplant patients compared to both dialysis groups. From the KDQOL there were significantly lower scores compared with the transplant patients for both groups of dialysis patients for the effects and burden of kidney disease and general symptoms and problems. However, overall health scores were significantly higher for dialysis patients compared with transplant patients. CONCLUSION: Kidney failure has a high cost in terms of health related quality of life. There was a large difference between patients who have received a functioning graft following kidney transplant versus the alternative methods of renal replacement therapy, that is, peritoneal dialysis and haemodialysis. Kidney transplant should be the treatment of choice, and every effort should be made to increase the availability of kidneys for transplantation.     

Subxiphoid pericardiastomy in the management of pericardial effusions.

Subxiphoid pericardiostomy for diagnosis and treatment of pericardial effusion was used in 21 patients. Total evacuation of the pericardial contents, direct inspection to break down loculations, simultaneous biopsies of the pericardium and pericardial fluid samples for diagnostic tests were achieved while avoiding the need for repeated pericardiocentesis and more invasive and difficult open drainage methods. Complete drainage without recurrence was obtained in 19 patients with one death and recurrence of effusion in another one. Two of these 19 cases developed constrictive pericarditis on follow-up and required a pericardiectomy. No other complications were encountered. The procedure can be done safely under local anaesthesia for all types of pericardial effusions providing prompt and long term relief of the abnormal haemodynamics.     

Cardiac tamponade in the blastic crisis of chronic myelogenous leukemia.

A 36-year-old man with Philadelphia chromosome-positive chronic myelogenous leukemia (CML) developed hemorrhagic pericarditis with tamponade as a terminal manifestation of the blastic crisis. Cardiac tamponade should be kept in mind as an uncommon cause of death of CML patients. Based on a literature review, symptomatic pericarditis in patients with CML blast crisis suggests imminent death. This is in contrast to long-term survival for patients in the chronic phase.     

Bacterial Pericarditis

Bacterial pericarditis occurs by direct infection during trauma, thoracic surgery, or catheter drainage, by spread from an intrathoracic, myocardial, or subdiaphragmatic focus, and by hematogenous dissemination. The frequent causes are Staphylococcus and Streptococcus (rheumatic pancarditis), Haemophilus, and M. tuberculosis. In AIDS pericarditis, the incidence of bacterial infection is much higher than in the general population, with a high proportion of Mycobacterium avium-intracellulare infection. Purulent pericarditis is the most serious manifestation of bacterial pericarditis, characterized by gross pus in the pericardium or microscopically purulent effusion. It is an acute, fulminant illness with fever in virtually all patients. Chest pain is uncommon. Purulent pericarditis is always fatal if untreated. The mortality rate in treated patients is 40%, and death is mostly due to cardiac tamponade, systemic toxicity, cardiac decompensation, and constriction. Tuberculous infection may present as acute pericarditis, cardiac tamponade, silent (often large) relapsing pericardial effusion, effusive-constrictive pericarditis, toxic symptoms with persistent fever, and acute, subacute, or chronic constriction. The mortality in untreated patients approaches 85%. Urgent pericardial drainage, combined with intravenous antibacterial therapy (e.g. vancomycin 1g twice daily, ceftriaxone 1-2g twice daily, and ciprofloxacin 400 mg/day) is mandatory in purulent pericarditis. Irrigation with urokinase or streptokinase, using large catheters, may liquify the purulent exudate, but open surgical drainage is preferable. The initial treatment of tuberculous pericarditis should include isoniazid 300 mg/day, rifampin 600 mg/day, pyrazinamide 15-30 mg/kg/day, and ethambutol 15-25 mg/kg/day. Prednisone 1-2 mg/kg/day is given for 5-7 days and progressively reduced to discontinuation in 6-8 weeks. Drug sensitivity testing is essential. Pericardiectomy is reserved for recurrent effusions or continued elevation of central venous pressure after 4-6 weeks of antituberculous and corticosteroid therapy.     

小儿心包积液病因分析

目的探讨小儿心包积液的病因。方法回顾性分析小儿心包积液患儿95例,根据心包积液量多少分为2组:中等至大量心包积液组(A组)41例,少量心包积液组(B组)54例。结果(1)2组心包填塞的发生率差异有统计学意义(P<0.01)。(2)2组病因构成比较差异有统计学意义(P<0.05)。病毒性感染44例占46.3%,居首位,其中急性病毒性心肌心包炎17例占17.9%。(3)2组治疗后,治愈率、好转率及病死率差异有统计学意义(P<0.05)。结论病毒感染是小儿心包积液最常见的病因;微小病毒B19是病毒性心包炎最重要的病原,且常合并心肌炎。     

心包切除治疗小儿渗出性心包炎

目的 探讨渗出性心包炎的病因诊断及心包切除指征。方法 17例均行心包切除术。11例术前诊断与术后病理诊断一致,其中化脓性心包炎8例,结核性心包炎1例,放射性心包炎2例;术前诊断特发性心包炎6例中,术后病理诊断4例为结核性,余2例为非特异性炎症。结果 2例术中心跳缓慢、无力,经治疗恢复,无术后并发症。随访1～10年,病儿心功能良好。结论 结核性心包炎、病毒性心包炎病因诊断困难,心包切除除其治疗作用外,还有诊断价值。对渗出性心包炎内科治疗效果不好者应及时行心包切除术,以解除心包填塞及预防心包缩窄,同时也切除了病灶。     

Effect of long-term cimetidine treatment on left ventricular function in haemodialysis patients with active hyperparathyroidism.

1 The effect of long-term oral cimetidine on left ventricular function was evaluated in chronic haemodialysis patients with active hyperparathyroidism. 2 Radionuclide ventriculography (seven patients) and echocardiography (five patients) revealed a significant increase in ejection fraction and mean velocity of circumferential fibre shortening six months after treatment. 3 The improved cardiac performance was associated with improvement of bone histology. C-terminal parathyroid hormone, serum calcium, and mean arterial pressure changed little after treatment. 4 The improved cardiac performance is thought to be related to the suppression of uraemic hyperparathyroidism by cimetidine. 5 The present study suggests that uraemic hyperparathyroidism may play an important role in "uraemic cardiomyopathy".     

Cefotaxime disposition pharmacokinetics during peritoneal dialysis

The pharmacokinetics of cefotaxime and its main metabolite des-acetyl-cefotaxime were studied after a single 1000 mg intravenous dose in 8 patients with end stage renal disease during peritoneal dialysis. Pharmacokinetic parameters were determined by iterative non-linear least squares regression analysis of plasma and dialysis fluid drug concentration curves. Biological half-life of cefotaxime ranged from 2.3 to 8.2 hours and total plasma clearance from 11 to 103 ml/min. (0.11 to 1.7 ml/min/kg b.wt). Only 1.4% to 4.2% of the intravenous dose of cefotaxime was distributed to the dialysis fluid. We conclude that the dosage of cefotaxime to uraemic patients adjusted to the renal function needs no further adjustment during peritoneal dialysis.     

No effect of renal function or dialysis on pharmacokinetics of cinacalcet (Sensipar/Mimpara)

OBJECTIVE: Cinacalcet (cinacalcet HCl; Sensipar/Mimpara) is a calcimimetic that is a treatment for secondary hyperparathyroidism in patients with renal failure. The objective of this study was to assess the effects of renal function and dialysis on the pharmacokinetics and pharmacodynamics of cinacalcet. METHODS: Two open-label, single-dose (75 mg) studies of cinacalcet were performed: study 1 examined 36 subjects who had renal function ranging from normal to requiring haemodialysis, and study 2 examined ten subjects who were receiving continuous ambulatory peritoneal dialysis. Cinacalcet plasma concentrations were determined using a liquid chromatography-mass spectrometry/mass spectrometry assay. Cinacalcet pharmacokinetics were assessed using noncompartmental analyses. RESULTS: Following single-dose administration of cinacalcet, there was no evidence of increasing exposure with increasing degree of renal impairment, and the pharmacokinetic profile was similar for all subjects regardless of whether they were receiving haemodialysis (no difference on dialysis or nondialysis days detected) or peritoneal dialysis. Protein binding of cinacalcet, determined in study 1 only, was similar in all groups and the level of renal function did not affect the pharmacodynamics (as determined by intact parathyroid hormone and calcium levels). No serious adverse events occurred during either study. CONCLUSION: The degree of renal impairment and mode of dialysis do not affect the pharmacokinetics or pharmacodynamics of cinacalcet. Therefore, the dose of cinacalcet does not need to be altered for degree of renal impairment or dialysis modality.     

Effects of carnitine administration in patients with chronic renal failure undergoing periodic dialysis, evaluated by computerized electromyography

The effects of chronic administration of L-carnitine were evaluated by EMG analysis in 20 uraemic patients undergoing periodical haemodialysis (mean duration of dialysis 34.7 months). No important changes in motor conduction velocity or distal latency of the external popliteal nerve were found after the treatment, while a reduction in the number of polyphasic muscle action potentials was observed. After carnitine administration, an increase of total EMG power was noted and the spectral array showed a progressive shift towards lower frequencies in 8 patients who had shown higher values. These results suggest that carnitine has a prevalent "myotrophic" effect.     

A case of traumatic cardiac tamponade showing sudden spontaneous disappearance of the pericardial fluid

Traumatic cardiac tamponade must be treated by pericardial drainage as soon as possible. We recently encountered a rare case of traumatic cardiac tamponade in which the pericardial fluid disappeared spontaneously immediately before the planned drainage. This case is reported in this paper. The patient was a 22-year-old male who was transported to our hospital after he sustained injuries in a traffic accident. The patient was diagnosed to have a facial bone fracture, bilateral lung contusions, myocardial contusion (suspected), injury to the spinal cord at the L3-L4 level, injury to the left kidney and pelvic fracture. After TAE was performed to deal with the bleeding from the injured pelvis, the patient was immediately hospitalized. About 6 hours after the injury, pericardial fluid accumulation began to be noted, and about 18 hours after the injury, the patient went into shock, responding poorly to fluid resuscitation and treatment with pressor agents. At this time, a diagnosis of cardiac tamponade was made and emergency operation was arranged for. However, just before this could be executed, the patient's blood pressure showed a sharp rise, accompanied by disappearance of the pericardial fluid. He continued to show steady improvement and could eventually be discharged from the hospital.     

Sevelamer hydrochloride: a review of its use for hyperphosphataemia in patients with end-stage renal disease on haemodialysis

Sevelamer (Renagel), an orally administered metal-free cationic hydrogel polymer/resin that binds dietary phosphate in the gastrointestinal (GI) tract, is approved for use in the US, Europe and several other countries for the treatment of hyperphosphataemia in adult patients with end-stage renal disease (ESRD) on haemodialysis or peritoneal dialysis.Clinical evidence shows that sevelamer was at least as effective as calcium acetate and calcium carbonate at controlling serum phosphorus, calcium-phosphorus product (Ca x P) and intact parathyroid hormone (iPTH) levels, but generally reduced serum calcium levels to a greater extent and was associated with a lower risk of hypercalcaemic episodes than calcium-based phosphate binders. Sevelamer appeared to slow the progression of cardiovascular calcification in patients with ESRD and also had a beneficial effect on serum low-density lipoprotein-cholesterol (LDL-C) levels. In patients receiving chronic haemodialysis, there was no between-group difference in all-cause mortality between sevelamer and calcium-based phosphate binder therapy in the primary efficacy analysis in the large (n >2100), 3-year DCOR trial; in the smaller (n = 109) nonblind RIND trial in patients new to dialysis, data suggest there is an overall survival benefit with sevelamer versus calcium-based phosphate binder treatment. The relative survival benefits and cost effectiveness of these phosphate binder therapies remains to be fully determined. Sevelamer treatment was generally as well tolerated as calcium acetate or calcium carbonate treatment. Overall, sevelamer is a valuable option for the management of hyperphosphataemia in patients with ESRD on haemodialysis.     

Congestive cardiomyopathy in uraemic patients on long term haemodialysis.

Five uraemic patients who developed progressive cardiac failure with clinical evidence of congestive cardiomyopathy at the start or during haemodialysis treatment were studied. The diagnosis of cardiomyopathy, for which there was no apparent cause, was confirmed by angiocardiographic and haemodynamic studies. These showed a significant increase in left ventricular end-diastolic volume over normal values obtained in 12 patients without uraemia. The mean velocity of myocardial fibre shortening was significantly decreased, as was the index of normalised rigidity. Three of the five patients presented the complete picture of the disease. The other two also had considerable ventricular dilatation and a decreased index of normalised rigidity but normal ejection fraction and only moderately decreased myocardial contractility indices. This suggests that there may be primary involvement of normalised heart muscle rigidity followed by secondary changes in myocardial contractility in uraemic patients with congestive cardiomyopathy.     

缩窄性心包炎术后早期预后的研究

目的 :研究影响缩窄性心包炎心包剥脱术早期预后的因素。方法 :分析了 2 5例心包剥脱术患者 ,结核性心包炎 2 0例 ,其中亚急性结核性心包炎 4例 ,开心术后及慢性透析患者各 1例 ,病因不明者 3例。依心功能将 2 5例患者分为改善组和非改善组 ,比较两组间的血液动力学变化和术前因素。结果 :在改善组 ,血液动力学的改善保持到术后早期 (术后 8d～ 10d) ,但非改善组血液动力学再度恶化 ,且心包积液和CRP的升高只出现在非改善组。结论 :认为缩窄性心包炎的病因和由心包炎引起的炎性反应程度与早期预后有关 ,加强抗炎治疗的同时早期手术可望取得良好的手术效果。     

Haemodialysis does not affect the pharmacokinetics of nifedipine.

To establish dosage recommendations in patients with end-stage renal disease undergoing chronic haemodialysis, nifedipine kinetics were studied between and during haemodialysis sessions. In eight patients, during the interdialytic period, peak plasma concentrations of nifedipine (29-332 ng/ml) were reached 0.5-1.0 h after administration of a single 10 mg oral dose. Elimination half-life and oral plasma clearance were respectively 2.6 +/- 0.5 h and 1 176 +/- 412 ml/min. Nifedipine plasma protein binding was decreased in uraemic patients (88.8 +/- 0.3% vs 94.4 +/- 0.1%) but not affected by haemodialysis. Removal by haemodialysis was low: the dialyser extraction ratio and the dialysis clearance were respectively 2.3 +/- 0.8% and 2.8 +/- 0.9 ml/min.     

Autopsy findings in diabetic nephropathy patients under dialysis, collected from the annuals of pathological autopsy cases in Japan

Collected from the Annuals of Pathological Autopsy Cases in Japan (1958-1980), autopsy findings of diabetic patients under dialysis were studied in 103 cases on peritoneal dialysis and 103 cases on hemodialysis. Direct causes of death in 13 cases (12.6%) of the 103 diabetic patients on peritoneal dialysis and in 8 cases (7.8%) of the 103 diabetic patients on hemodialysis was infections, and in seven cases (6.8%) on peritoneal dialysis and 19 cases (18.4%) on hemodialysis was bleeding. The incidence of bleeding in diabetic patients on hemodialysis was significantly higher than that in peritoneal dialysis cases (p less than 0.025). Other direct causes of death in diabetic patients on dialysis included myocardial infarction, uremia, pulmonary edema, liver cirrhosis and carcinoma. No significant difference was seen between peritoneal dialysis and hemodialysis, except the incidence of complications of bleeding and pericarditis.     

应用子宫填塞球囊导管治疗产后出血的初步经验

目的 探讨应用子宫填塞球囊导管治疗产后出血的疗效及安全性.方法 对我院2010年1月-2012年2月,24例使用子宫填塞球囊导管治疗产后出血患者进行回顾性分析.患者年龄22～34岁,平均27.5岁,其中产后出血病因宫缩乏力12例、前置胎盘4例,胎盘粘连8例.结果 全部病例均能应用子宫填塞球囊导管达到止血目的,无一例行子宫切除术.一次止血有效率达91.6％.2例患者出现再发出血,再次充盈气囊止血后,两例患者于24小时再尝试取出水囊,未再发大出血,总止血有效率达100％.无一例需行子宫切除术或死亡,术后随访1～24个月,24例均能正常子宫复旧,恢复月经时间1～3个月,无一例出现产褥期感染,及卵巢早衰症状.结论 应用子宫填塞球囊导管治疗产后出血是一种安全、有效的治疗方式,值得临床推广应用.