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RESUMO Nas últimas décadas, têm-se observado o crescimento da demanda de água e o agravamento dos cenários de escassez hídrica, bem como a ampliação de alternativas de reuso de água de efluentes de qualidade inferior, em particular de esgotos domésticos tratados. Objetivou-se, com este trabalho, avaliar a influência do substrato de pó de coco no controle de transporte de solutos em solos irrigados com esgoto tratado doméstico. A água residuária doméstica tratada provém da Unidade Experimental de Tratamento e Reúso Hidroagrícola, no distrito de Mutuca-PE. O delineamento experimental foi em esquema fatorial (2 × 3), cujos fatores avaliados compreenderam dois tipos de solos típicos da região (Neossolo Litólico e Argissolo Amarelo) e três tratamentos (sem pó de coco, 1 cm de pó de coco e 2 cm de pó de coco), com cinco repetições. Os parâmetros de transporte dos íons sódio e potássio foram obtidos por ajuste numérico, utilizando-se o modelo STANMOD. Constatou-se a existência de interação com soluto, sódio e potássio, em solo arenoso. O modelo STANMOD apresentou ótimo desempenho na simulação do transporte de solutos no solo. A cobertura de pó de coco mostrou-se eficiente na diminuição da lixiviação de íons em ambos os solos estudados.
ABSTRACT In the last decades, there has been an increase in the demand for water and the aggravation of water scarcity scenarios, as well as the expansion of water reuse alternatives for lower quality effluents, in particular treated domestic sewage. The objective of this study was to evaluate the influence of coconut powder substrate on the control of solute transport in irrigated soils with treated sewage reuse. The treated domestic wastewater comes from the Experimental Unit for Treatment and Agricultural Reuse in the district of Mutuca, Pernambuco. The experimental design was in a factorial scheme (2 × 3), whose evaluated factors comprised two types of soils typical of the region (Leptosols and Yellow Argisol) and three treatments (no coconut powder, 1 cm coconut powder, and 2 cm coconut powder) with five replicates. The transport parameters of the sodium and potassium ions were obtained by numerical adjustment using the STANMOD model. It was found the existence of interaction with solute, sodium, and potassium in sandy soil. The STANMOD model presented excellent performance in the simulation of solute transport in the soil. Soil coverage with coconut powder was shown to be efficient in reducing leaching of ions in both studied soils.
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The peritoneal equilibration test (PET) is the most widespread method for assessing water and solute transport across the peritoneal membrane. This study compared three methods: traditional PET (t-PET), mini-PET, and modified PET (mod-PET). Non-diabetic adults (n=21) who had been on peritoneal dialysis (PD) for at least three months underwent t-PET (glucose 2.5%-4 h), mini-PET (glucose 3.86%-1 h), and mod-PET (glucose 3.86%-4 h) to determine dialysate-to-plasma concentration ratio (D/P) for creatinine and dialysate-to-baseline dialysate concentration ratio (D/D0) for glucose. Agreement between methods regarding D/P creatinine and D/D0 glucose was assessed using analysis of variance (ANOVA), Pearson's correlation coefficient, and Bland-Altman analysis. D/P creatinine differed between t-PET and mini-PET (P<0.001) and between mod-PET and mini-PET (P<0.01) but not between t-PET and mod-PET (P=0.746). The correlation of D/P creatinine with t-PET vs mod-PET was significant (r=0.387, P=0.009) but not that of t-PET vs mini-PET (r=0.088, P=0.241). Estimated bias was −0.029 (P=0.201) between t-PET and mod-PET, and 0.206 (P<0.001) between t-PET and mini-PET. D/D0 glucose differed between t-PET and mod-PET (P=0.003) and between mod-PET and mini-PET (P=0.002) but not between t-PET and mini-PET (P=0.885). The correlations of D/D0 glucose in t-PET vs mod-PET (r=−0.017, P=0.421) or t-PET vs mini-PET (r=0.152, P=0.609) were not significant. Estimated bias was 0.122 (P=0.026) between t-PET and mod-PET, and 0.122 (P=0.026) between t-PET and mini-PET. The significant correlation of D/P creatinine between t-PET and mod-PET suggested that the latter is a good alternative to t-PET. There was no such correlation between t-PET and mini-PET.
Subject(s)
Humans , Male , Female , Middle Aged , Peritoneal Dialysis/methods , Kidney Failure, Chronic/therapy , Peritoneum/metabolism , Biological Transport , Creatinine/blood , Glucose/analysis , Kidney Failure, Chronic/bloodABSTRACT
Objective · To investigate the clinical characteristics of initial peritoneal dialysis (PD) patients with different peritoneal transport status, and analyze risk factors of high peritoneal transport status in PD patients. Methods · A total of 455 consecutive PD patients newly starting PD between January 2007 to October 2015 were retrospectively analyzed. According to the results of the first sPET, patients were divided into H/HA (4h D/Pcr ≥ 0.65) and L/ LA (4h D/Pcr<0.65) groups. Clinical and biochemical characteristics between the two groups were compared. Multivariate logistic regression model was established to investigate risk factors of higher peritoneal transport status of incident PD patients. Results · The study included 372 incident PD patients. The L/LA group and H/HA group had 264 cases (71.2%) and 108 cases (28.8%) respectively. The H/HA group had higher proportion of male patients (63.0% vs 50.8%, P=0.03), lower residual renal function [RRF, (4.26±2.77) mL/min vs (5.79±4.53) mL/min, P<0.01], lower serum albumin level [(29.34±6.89) g/L vs (32.08±5.86) g/L, P=0.00], and more frequent diabetic nephropathy (19.4% vs 9.5%, P=0.00), compared with L/LA group. Univariate and multivariate logistic regression analysis showed that higher peritoneal transport status was associated with lower serum albumin level (OR=0.96, 95% CI 0.28-0.99; P=0.02), male (OR=1.92, 95% CI 1.19-3.12; P=0.00), presence of diabetic nephropathy (OR=2.52, 95% CI 1.26-5.05; P=0.00) and lower residual renal function (OR=0.90,95% CI 0.83-0.96; P=0.00). The level of hsCRP in patients with hypoalbuminemia was higher than that in patients with normal albumin level (1.69 mg/L vs 0.69 mg/L, P=0.00). Conclusion · Low and low average peritoneal transport status accounted for the majority of the patients in this study. Low serum albumin levels, male, diabetic nephropathy, RRF were risk factors of initial high peritoneal solute transport status. Chronic inflammatory status might partially explain for the correlation between hypoalbuminemia and high peritoneal solute transport status in PD patients.
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Objective To study the influence from load strength on solute transport rate in lacunar-canalicular system (LCS) of loaded tibia using finite element method.Methods Based on micro-CT scan images of adult mice tibia, the finite element model of the tibia, which was regarded as being homogeneous biphasic-solute, was established by software of Mimics, Hypermesh and FEBio. The relationship between transport rate and solute diffusivity/load strength was obtained by setting 3 groups of different solute diffusivity (3, 15, 30 μm2/s) and load strength (0.2, 2.0, 5.0 N), respectively. By comparing the results from both fluorescence recovery after photobleaching (FRAP) experiment and finite element method, the effect of load stimulation on transport enhancement was analyzed. Results The transport rate increased with the increase of diffusion rate and load strength. The results from finite element method were basically consistent with the solute transport rules by comparing data from FRAP experiment. Conclusions The research findings can provide some basis for load response and liquidity in deep area of cortical bone, and for further revealing the mechanism of bone regeneration.
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BACKGROUND:The present study was designed to determine factors related to baseline peritoneal small solute transport rate (PSTR) from incident Korean peritoneal dialysis (PD) patients using modified peritoneal equilibration test (PET). METHODS:Incident PD patients whose duration of PD is between 4 weeks and 6 months were enrolled from four major university hospitals in Seoul. Modified PET with 3.86% glucose solution and adequacy test were performed. RESULT: 1) Our PET result from incident Korean PD patients showed results similar to that from the Caucacian patients. 2) The patients were divided into four groups based on the PSTR:serum albumin at time of PET, dip dialysate/plasma sodium, dialysate/plasma albumin ratio and peritoneal albumin excretion were significantly different among the four transport types (p<0.05). 3) D/PAlb was significantly higher in the high transport group than in the low transport. Serum albumin concentration before the onset of PD was not different among the four groups but was significantly different at the time of PET. 4) There was no difference of D/PCr4 between the diabetic (0.72+/-0.10) and the non-diabetic (0.72+/-0.11) groups. 5) PSTR in incidental PD patients was correlated with D/PAlb and dip D/P(Na). CONCLUSION:Our PET results from incidental Korean PD patients turned out to be showed results similar to those from Caucacian patients. There were no differences in age, BSA, BMI, nutrition index, CRP, residual renal function among four transport types in incidental PD patients. PSTR in incidental PD patients was correlated with D/PAlb and dip D/P(Na).
Subject(s)
Humans , Glucose , Hospitals, University , Nutrition Assessment , Peritoneal Dialysis , Seoul , Serum Albumin , SodiumABSTRACT
BACKGROUND: Peritoneal solute transport rate, assessed by PET, varies widely among patients and has been shown to differ significantly among different ethnic groups. The aim of the present study is to investigate the peritoneal transport characteristics in Korean peritoneal dialysis (PD) patients and factors that predict peritoneal transport status. METHODS: Between May 2001 and February 2006, 141 patients on PD performed a standard 4-hour PET within the first 6 months after initiation of PD therapy. RESULTS: Of these 141 patients, there were 71males and 70 females. The mean age of the patients was 51.2+/-12.5 years and the etiology of renal failure was diabetes in 67 patients (47.5%). The mean 4-hour D/P creatinine ratio was 0.68+/-0.11. Compared with a mean of 0.65+/-0.15 as determined by Twardowski et al, our patients have significantly higher mean solute transport rate (p<0.05). Numbers of low (L), low-average (LA), high-average (HA), and high (H) transporters were 15 (10.6%). 68 (48.2 %), 53 (37.6%) and 5 (3.5%), respectively. However, according to our own data, the number of L, LA, HA and H were 18 (12.8%), 42 (29.8%), 64 (45.4%) and 17 (12.1%), respectively, significantly different from those classified by Twardowski et al. In univariate analysis, older age, hypoalbuminemia and lower BMI were predictive of high transport status. Using multiple linear regression, only hypoalbuminemia was independently predictive of higher 4-hour D/Pcr (p=0.000). CONCLUSION: Korean PD patients have a higher mean solute transport rate than Twardowskis data, and serum albumin is an independent predictor of high transport status. Further prospective studies with a large number of patients are needed for evaluating the diversity of peritoneal transport characteristics in different ethnic populations.
Subject(s)
Female , Male , HumansABSTRACT
BACKGROUND: Peritoneal solute transport rate, assessed by PET, varies widely among patients and has been shown to differ significantly among different ethnic groups. The aim of the present study is to investigate the peritoneal transport characteristics in Korean peritoneal dialysis (PD) patients and factors that predict peritoneal transport status. METHODS: Between May 2001 and February 2006, 141 patients on PD performed a standard 4-hour PET within the first 6 months after initiation of PD therapy. RESULTS: Of these 141 patients, there were 71males and 70 females. The mean age of the patients was 51.2+/-12.5 years and the etiology of renal failure was diabetes in 67 patients (47.5%). The mean 4-hour D/P creatinine ratio was 0.68+/-0.11. Compared with a mean of 0.65+/-0.15 as determined by Twardowski et al, our patients have significantly higher mean solute transport rate (p<0.05). Numbers of low (L), low-average (LA), high-average (HA), and high (H) transporters were 15 (10.6%). 68 (48.2 %), 53 (37.6%) and 5 (3.5%), respectively. However, according to our own data, the number of L, LA, HA and H were 18 (12.8%), 42 (29.8%), 64 (45.4%) and 17 (12.1%), respectively, significantly different from those classified by Twardowski et al. In univariate analysis, older age, hypoalbuminemia and lower BMI were predictive of high transport status. Using multiple linear regression, only hypoalbuminemia was independently predictive of higher 4-hour D/Pcr (p=0.000). CONCLUSION: Korean PD patients have a higher mean solute transport rate than Twardowskis data, and serum albumin is an independent predictor of high transport status. Further prospective studies with a large number of patients are needed for evaluating the diversity of peritoneal transport characteristics in different ethnic populations.
Subject(s)
Female , Male , HumansABSTRACT
Using PDC test, peritoneal function in CAPD patients was compared between diabetes and non- diabetes. PDC test were performed in 12 diabetic and 11 nondiabetic CAPD patients. Urea, creatinine, and albumin were measured in each dialysate effluent. Blood urea nitrogen, creatinine, glucose, albumin, and sodium were measured in blood sample at the start and the end of the study. Area parameter(Ao/d x), hydraulic conductance(LpS), final absorption rate (JVAR), large pore fluid flux(JVr.), urea generation rate(UGR), creatinine generation rate (CGR), protein nitrogen appearance/protein catabolic rate(PNA/PCR), residual renal Ccr, total Ccr(PD Ccr+renal Ccr), water removal via PD, total ultrafiltration, and PD clearance of urea, creatinine, vitamin B12 b2 microglobulin, and albumin were calculated. In diabetic patients(n=12), serum albumin was lower in patients on CAPD for less 6 months than patients on CAPD for more 15 months. But total ultrafiltration was lower in patients on CAPD for more 15 months. In non-diabetics(n=ll), protein loss across the peritoneum was lower in patients on CAPD for more 15 months. Other PDC parameters were not different in diabetic and non-diabetic patients according to CAPD duration. In patients on CAPD for less 6 months, serum albumin and PNA/PCR were lower in diabetics than non-diabetics.
Subject(s)
Humans , Absorption , Blood Urea Nitrogen , Creatinine , Diabetes Mellitus , Dialysis , Glucose , Nitrogen , Peritoneal Dialysis, Continuous Ambulatory , Peritoneum , Serum Albumin , Sodium , Ultrafiltration , Urea , Vitamin B 12 , WaterABSTRACT
OBJECTIVES: The peritoneal equilibration test(PET) is routinely performed in adults treated with chronic peritoneal dialysis to assess the peritoneal transport rate and to optimize treatment prescription. This study focuses on the evaluation of characteristics of peri toneal solute transport rates and physical and serological factors affecting peritoneal transport rate performed in our continuous ambulatory peritoneal dialysis(CAPD) patients due to guide adequate peri toneal dialysis form. METHODS: We analyzed 95 PET results which had been tested on the 28th day of CAPD and physical and serological values, such as age, sex, diabetes mellitus, height, weight, body surface area, arterial blood pressure, blood urea nitrogen, creatinine, glucose, cholesterol, triglyceride, total protein, albumin, hematocrit, hemoglo bin, sodium, potassium, phosphate which had been ob tained on the day of PET. RESULTS: 1) According to transport rate, high transport rate group was 9 cases(9.5%), high average transport group 26 cases(27.4%), low average transport rate group 32 cases(33.6%), and low transport rate group 28 cases (29.5%) respectivly. 2) The average of 4hour D/PCr was 0.60, 4hour D/Do glucose was 0.46, and drain volume was 2480ml. Thus the average of peritoneal solute transport rate of total patients was low average transport rate. 3) Factors affecting peritoneal solute transport rate were age, body surface area, plasma albumin, serum creatinine and triglyceride level. CONCLUSION: These findings suggest that high dose peritoneal dialysis form should be used in our CAPD patients because most of them have low average peritoneal transport rate, and age, body surface area, plasma albumin, serum creatinine, and triglyceride level should be consid ered when select the adequate peritoneal dialysis form.