容量负荷对腹膜透析患者残余肾功能的影响

目的 探讨容量状态及其他因素对腹膜透析患者残余肾功能（residual kidney function,RKF）下降的影响。方法 分析复旦大学附属华山医院腹膜透析中心自2010年6月至2017年8月期间进行腹膜透析（peritoneal dialysis,PD）并且规律随访患者的临床资料,筛除有腹膜炎病史、临床资料不全、中途由外院转入的患者。以患者开始规律PD第3个月的估算 肾小球滤过率（estimated glomerular filtration rate,eGFR）作为基础值,记录腹膜透析患者在≤36个月间内所有基本临床特征、透析相关变量和主要生化指标。终点事件定义为在开始PD 24个月内的eGFR下降为0。采用单因素及多因素线性回归和Cox回归模型法分析影响PD患者eGFR下降的影响因素。结果 本研究纳入96名患者,基线eGFR为（4.20±3.00） mL·min^-1·1.73 m^-2,单因素和多因素线性回归结果显示体重指数（body mass index,BMI）和时间平均后的终末段脑钠肽前体（NT-proB-type natriuretic peptide,BNP）为共同影响PD患者RKF下降的危险因素。单因素Cox回归分析结果显示BMI、标准化蛋白分解率（normalized protein catabolic rate,nPCR）、平均动脉压（mean arterial pressure,MAP）和时间平均后的BNP为影响PD患者进入终点事件的共同危险因素。多因素Cox回归分析结果显示时间平均后的BNP为影响PD患者进入终点事件的独立影响因素。结论 容量过剩与新开始PD患者RKF下降可能相关。     

How reliable is eGFR when calculating drug dosage in acute medical admissions?

Background: The Modification of Diet in Renal Disease‐derived estimation of glomerular filtration rate (eGFR) is used widely. Although validated in stable chronic kidney disease (CKD) outpatients, it is not known how it performs in those presenting with acute medical illness. Aim: We aimed to compare eGFR with Cockroft Gault (CG) – the renal function assessment tool available prior to eGFR – to assess the difference in clinical outcome that would occur when one over another estimation is used in practice. In particular, we wished to assess whether use of eGFR would have resulted in a change of dose of commonly used acutely administered medications. Methods: Acute medical admissions presenting to a tertiary hospital between August and December 2008 were included. Serum creatinine concentration, age, sex, height and weight were collected. Renal function was estimated by both estimates. Movement from CKD class 3 to 4 or 5 was measured – a clinically used cut‐off point for changes in management. Results: A total of 54 patients was included. eGFR values were higher than those estimated by CG. Almost half of patients categorized as CKD stage 4–5 using CG were only categorized as CKD stage 3 using eGFR. Conclusion: Although we did not use a gold standard estimation of GFR, this study shows that estimates of renal function vary in a clinically significant manner. As estimates of GFR are used to adjust drug dosages and to stratify for many other treatments, it is imperative that we find a method of estimating kidney function that is readily available, consistent and accurate.     

Novel Risk Factors for Progression of Diabetic and Nondiabetic CKD: Findings From the Chronic Renal Insufficiency Cohort (CRIC) Study

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Exercise E/e′ Is a Determinant of Exercise Capacity and Adverse Cardiovascular Outcomes in Chronic Kidney Disease

ObjectivesThis study sought to assess the relationship between E/e′ and exercise capacity in patients with chronic kidney disease (CKD) and evaluate its prognostic role.BackgroundPatients with CKD have diastolic dysfunction, reduced physical fitness, and elevated risk of cardiovascular disease.MethodsPatients with stage 3 and 4 CKD without previous cardiac disease underwent resting and exercise stress echocardiograms with assessment of exercise E/e′. Patients were compared to age-, sex-, and risk factor–matched control individuals and were followed annually for 5 years for cardiovascular death and major adverse cardiovascular event(s) (MACE). Exercise capacity was assessed as metabolic equivalents (METs), with reduced exercise capacity defined as METs of ≤7. Raised exercise E/e′ was defined as >13.ResultsA total of 156 patients with CKD (age 62.8 ± 10.6 years; male: 62%) were compared to 156 matched control individuals. Patients with CKD were more likely to be anemic (p < 0.01) and had increased left ventricular mass (p < 0.01), larger left atrial volumes (p < 0.01), and higher resting (p < 0.01) and exercise E/e′ (p < 0.01). Patients with CKD achieved lower exercise METs (p < 0.01), and more patients with CKD had METs of ≤7 (p < 0.01). Receiver-operating characteristic curves showed exercise E/e′ (area under the curve [AUC]: 0.89; 95% CI: 0.84 to 0.95; p < 0.01) as the strongest predictor of reduced exercise capacity in patients with CKD. Over a follow-up period of 41.4 months, a raised exercise E/e′ of >13 was an independent predictor of cardiovascular death and MACE on unadjusted and adjusted hazard models.ConclusionE/e′ is a strong predictor of exercise capacity and METs achieved by patients with CKD. Exercise capacity was reduced in patients with CKD, presumably consequent to diastolic dysfunction. Elevated exercise E/e′ in patients with CKD is an independent predictor of cardiovascular death and MACE.     

4D In-Situ Microscopy of Aerosol Filtration in a Wall Flow Filter

The transient nature of the internal pore structure of particulate wall flow filters, caused by the continuous deposition of particulate matter, makes studying their flow and filtration characteristics challenging. In this article we present a new methodology and first experimental demonstration of time resolved in-situ synchrotron micro X-ray computed tomography (micro-CT) to study aerosol filtration. We directly imaged in 4D (3D plus time) pore scale deposits of TiO2 nanoparticles (nominal mean primary diameter of 25 nm) with a pixel resolution of 1.6 μm. We obtained 3D tomograms at a rate of ∼1 per minute. The combined spatial and temporal resolution allows us to observe pore blocking and filling phenomena as they occur in the filter’s pore space. We quantified the reduction in filter porosity over time, from an initial porosity of 0.60 to a final porosity of 0.56 after 20 min. Furthermore, the penetration depth of particulate deposits and filtration rate was quantified. This novel image-based method offers valuable and statistically relevant insights into how the pore structure and function evolves during particulate filtration. Our data set will allow validation of simulations of automotive wall flow filters. Evolutions of this experimental design have potential for the study of a wide range of dry aerosol filters and could be directly applied to catalysed automotive wall flow filters.     

Exercise as a provocative test in early renal disease in Type 1 (insulin-dependent) diabetes: albuminuric,systemic and renal haemodynamic responses

Summary The value of exercise as a provocative test for early renal disease in Type 1 (insulin-dependent) diabetes was reevaluated. Three carefully characterized groups of males were studied: 10 non-diabetic controls, 16 diabetic patients (group 1) with normal urinary albumin excretion (< 15 g/min) and 14 Albustix-negative diabetics (group 2) with increased urinary albumin excretion (15–122 g/min). Assignment to a study group was made on the basis of three 24-h urine collections, and the groups were well matched for age, weight, height, and serum creatinine concentration. The two diabetic groups were similar with regard to duration of disease (13±6 versus 16±3 years), metabolic control (HbA_1c: 8.4±1.4 versus 8.7±1.3%) and degree of diabetic complications (beat-to-beat variation and retinopathy). An exercise protocol of 450 and 600 kpm/min workloads was employed. In the resting state group 2 patients had elevated systolic blood pressure compared with the normal subjects (132±13 versus 119±9 mmHg), and their glomerular filtration rate was significantly reduced compared with group 1 (123±19 versus 138±15ml/min per 1.73m², p < 0.05). During exercise the urinary albumin excretion rate increased significantly in all three groups (normal subjects: 6±0.7 to 8±1.3 (g/min); group 1: 6±0.6 to 9±1 g/min and group 2: 48±10 to 113±23 g/min), the relative increase being higher in group 2 (p < 0.01). The changes in systemic haemodynamics were similar in all three groups in spite of a reduced maximum working capacity in group 2 (949±249 versus group 1:1163±200 and normal subjects 1267±264 kpm/min (p < 0.05). The renal haemodynamic changes were qualitatively similar for the three groups, but the filtration fraction during exercise increased in groups 1 and 2 to almost identical values and were significantly higher than in normal subjects (group 1 + group 2: 0.29±0.02 versus normal subjects: 0.26±0.03, p < 0.02). These findings suggest that an elevated transcapillary pressure gradient, as obtained during moderate exercise, will not cause an abnormal increase in albumin excretion per se. A functional glomerular lesion, already recognisable at rest (elevated albumin excretion) must also be present.     

Presence of insulin-like immunoreactivity and its biosynthesis in rat and human parotid gland

Summary Extracts from homogenates of rat and human parotid glands contained insulin-like immunoreactivity. The values were 5.6±2.8 ng/g wet tissue in six groups of rat parotid glands and 23.8 and 39.7 ng/g wet tissue in two human extracts. Upon gel filtration immunoreactive insulin of rat origin was eluted in a peak corresponding to the elution volume of isotopically labelled insulin. The material obtained from the two peak fractions showed an immunoassay dilution curve identical with that of rat insulin. Furthermore, biosynthesis of insulin-like immunoreactivity in rat and human parotid glands was confirmed in vitro by a specific separation method using anti-insulin antibody. These findings suggest that the parotid gland may be a further extrapancreatic source of insulin, and that insulin biosynthesis does occur in extrapancreatic tissues.     

Effect of post-transplant double filtration plasmapheresis on recurrent focal and segmental glomerulosclerosis in renal transplant recipients

In the present study, we reviewed the effect of post-transplant double filtration plasmapheresis (DFPP) on recurrent focal segmental glomerulosclerosis (FSGS) in the transplanted kidney allograft. Sixteen patients with post-transplant recurrent FSGS were enrolled in this study. Out of 16 patients with recurrent FSGS after transplantation, five did not receive DFPP and lost their grafts, while 11 did receive DFPP and four of these patients lost their grafts. Seven patients were able to maintain normal renal function for an average observation period of 57.1 +/- 40.7 months (range 7-125 months). In five patients who had a significant reduction in urinary protein after DFPP, the urinary protein level decreased from 26.60 +/- 23.05 g/day (range 3.34-62.6 g/day) to 2.95 +/- 3.42 g/day (range 0.02-8.64 g/day) and renal function was maintained. The beneficial effects of DFPP on graft outcome were more likely to occur if the patients experienced a marked drop in urinary excretion. Thus, post-transplant DFPP appears to be effective for reducing urinary protein levels and improving long-term graft survival. With the small numbers in this trial, however, none of the findings were statistically significant. We recommend the use of post-transplant DFPP to prevent the progression of recurrent FSGS.