Extraction Improvement of the Bioactive Blue-Green Pigment "Marennine" from Diatom Haslea ostrearia's Blue Water: A Solid-Phase Method Based on Graphitic Matrices.

The compound "marennine" is a blue-green pigment produced by the benthic microalgae Haslea ostrearia, with pathogenicity reduction activities against some bacteria and promising potential as a natural pigment in seafood industries. After decades of research, the chemical family of this compound still remains unclear, mainly because structural studies were impaired by the presence of co-extracted compounds in marennine isolates. To improve the purity of marennine extract, we developed a novel extraction method using a graphitic stationary phase, which provides various advantages over the previous procedure using tandem ultrafiltration. Our method is faster, more versatile, provides a better crude yield (66%, compared to 57% for ultrafiltration) and is amenable to upscaling with continuous photobioreactor cultivation. Our goal was to take advantage of the modulable surface properties of the graphitic matrix by optimizing its interactions with marennine. As such, the effects of organic modifiers, pH and reducing agents were studied. With this improvement on marennine purification, we achieved altogether the isolation of a fucoidan-related, sulfated polysaccharide from blue water. Characterization of the polysaccharides fraction suggests that roughly half of UV-absorbing compounds could be isolated from the marennine crude extracts. The identification of sulfated polysaccharides could be a major breakthrough for marennine purification, providing targeted isolation techniques. Likewise, the added value of Haslea ostrearia and the role of polysaccharides in previous marennine chemical characterization and bioactivity studies remain to be determined.

Quantification by Ultrafiltration and Immunofixation Electrophoresis Testing for Monoclonal Serum Free Light Chains.

OBJECTIVE: Measurement of monoclonal immunoglobulins is a reliable estimate of the plasma cell tumor mass. About 15% of plasma cell myelomas secrete light chains only. The concentration of serum free light chains is insufficient evidence of the monoclonal light chain burden. A sensitive quantitative estimate of serum free monoclonal light chains could be useful for monitoring patients with light chain myeloma. We describe such an assay that does not require mass-spectrometry equipment or expertise. METHODS: Serum specimens from patients with known light chain myelomas and controls were subjected to ultrafiltration through a membrane with pore size of 50 kDa. The filtrate was concentrated and tested by immunofixation electrophoresis. The relative area under the monoclonal peak, compared to that of the total involved light chain composition, was estimated by densitometric scanning of immunofixation gels. The proportion of the area occupied by the monoclonal peak in representative densitometric scans was used to arrive at the total serum concentration of the monoclonal serum free light chains. RESULTS: Using an ultracentrifugation and concentration process, monoclonal serum free light chains were detectable, along with polyclonal light chains, in all 10 patients with active light chain myelomas. Monoclonal light chains were identified in serum specimens that did not reveal monoclonal light chains by conventional immunofixation electrophoresis. The limit of detection by this method was 1.0 mg/L of monoclonal serum free light chains. CONCLUSION: The method described here is simple enough to be implemented in academic medical center clinical laboratories and does not require special reagents, equipment, or expertise. Even though urine examination is the preferred method for the diagnosis of light chain plasma cell myelomas, measurement of the concentration of serum free light chains provides a convenient, albeit inadequate, way to monitor the course of disease. The method described here allows effective electrophoretic differentiation of monoclonal serum free light chain from polyclonal serum free light chains and provides a quantitation of the monoclonal serum free light chains in monitoring light chain monoclonal gammopathies.

Comparison of the performance of prepared pristine and TiO2 coated UF/NF membranes for two types of oil-in-water emulsion separation.

Polysulfone ultrafiltration (UF) and polypiperazine-amide nanofiltration (NF) membranes were first fabricated by phase inversion and interfacial polymerization, and then modified by the commonly used TiO2 on the membrane surface, respectively. Compared with the pristine UF and NF membranes, pure water flux decreased by 40.66% for modified UF membrane and 12.92% for modified NF membrane, while the contact angle of the modified membranes decreased from 66.5° to 35.3° for UF membrane and from 48.2° to37.7° for NF membrane. However, the membrane modified by TiO2 nanoparticles for both UF and NF membranes exhibited much better anti-fouling and separation performance for two types of oil-in-water emulsions with different droplet size (i.e., prepared oil-in-water emulsion with low salinity and oil produced water in Shengli oilfield, China). It was obvious that water flux of modified UF only slightly decreased and the stable water flux was 2.2 times and 15.6% higher than that of pristine membranes for the prepared oil-in-water emulsion and produced water, respectively. According to the five fouling models for UF, the TiO2 modified UF membrane could alleviate the fouling on membrane surface and greatly increase water flux by reducing the adsorption, deposition, blockage of membrane pores and formation of cake layer for two types of oil-in-water emulsion. For NF, water flux of the modified membrane increased by 66.1% and 22.8% for prepared oil-in-water emulsion and produced water, respectively. TiO2 coating effectively alleviated the oil adhesion and cake layer formation on the membrane surface.

Net ultrafiltration intensity and mortality in critically ill patients with fluid overload.

BACKGROUND: Although net ultrafiltration (UFNET) is frequently used for treatment of fluid overload in critically ill patients with acute kidney injury, the optimal intensity of UFNET is unclear. Among critically ill patients with fluid overload receiving renal replacement therapy (RRT), we examined the association between UFNET intensity and risk-adjusted 1-year mortality. METHODS: We selected patients with fluid overload ≥ 5% of body weight prior to initiation of RRT from a large academic medical center ICU dataset. UFNET intensity was calculated as the net volume of fluid ultrafiltered per day from initiation of either continuous or intermittent RRT until the end of ICU stay adjusted for patient hospital admission body weight. We stratified UFNET as low (≤ 20 ml/kg/day), moderate (> 20 to ≤ 25 ml/kg/day) or high (> 25 ml/kg/day) intensity. We adjusted for age, sex, body mass index, race, surgery, baseline estimated glomerular filtration rate, oliguria, first RRT modality, pre-RRT fluid balance, duration of RRT, time to RRT initiation from ICU admission, APACHE III score, mechanical ventilation use, suspected sepsis, mean arterial pressure on day 1 of RRT, cumulative fluid balance during RRT and cumulative vasopressor dose during RRT. We fitted logistic regression for 1-year mortality, Gray's survival model and propensity matching to account for indication bias. RESULTS: Of 1075 patients, the distribution of high, moderate and low-intensity UFNET groups was 40.4%, 15.2% and 44.2% and 1-year mortality was 59.4% vs 60.2% vs 69.7%, respectively (p = 0.003). Using logistic regression, high-intensity compared with low-intensity UFNET was associated with lower mortality (adjusted odds ratio 0.61, 95% CI 0.41-0.93, p = 0.02). Using Gray's model, high UFNET was associated with decreased mortality up to 39 days after ICU admission (adjusted hazard ratio range 0.50-0.73). After combining low and moderate-intensity UFNET groups (n = 258) and propensity matching with the high-intensity group (n = 258), UFNET intensity > 25 ml/kg/day compared with ≤ 25 ml/kg/day was associated with lower mortality (57% vs 67.8%, p = 0.01). Findings were robust to several sensitivity analyses. CONCLUSIONS: Among critically ill patients with ≥ 5% fluid overload and receiving RRT, UFNET intensity > 25 ml/kg/day compared with ≤ 20 ml/kg/day was associated with lower 1-year risk-adjusted mortality. Whether tolerating intensive UFNET is just a marker for recovery or a mediator requires further research.

Optimization of coagulation pre-treatment for alleviating ultrafiltration membrane fouling: The role of floc properties on Al species.

This study investigated membrane fouling in a coagulation/ultrafiltration (C-UF) process by comparing the floc properties and humic acid (HA) removal efficiency of three hydrous Al(III) species (Ala, Alb, and Alc). The results indicated that the coagulation and membrane mechanisms were different for all three Al species because of the differences in floc properties. The HA removal efficiency increased with increasing Al dosage until an equilibrium was reached at the optimal dosage of 6 mg L-1. In addition, membrane fouling gradually decreased as the Al dosages increased. Regardless of coagulant type, the OH and COOH functional groups of HA reacted with the Al species. Both external and internal membrane fouling were strongly dependent on the porosity of the cake layer and on the size distribution of the floc particulates, respectively. The pore area of the cake layer formed by the Ala-coagulated effluent was large because of the strong charge neutralization. Moreover, Ala generated large and loose flocs with a porous cake layer that mitigated external fouling. However, the internal fouling with the Alc coagulant was significant because the concentration of residual aggregates in the membrane pores was high.

Target weight achievement and ultrafiltration rate thresholds: potential patient implications.

BACKGROUND: Higher ultrafiltration (UF) rates and extracellular hypo- and hypervolemia are associated with adverse outcomes among maintenance hemodialysis patients. The Centers for Medicare and Medicaid Services recently considered UF rate and target weight achievement measures for ESRD Quality Incentive Program inclusion. The dual measures were intended to promote balance between too aggressive and too conservative fluid removal. The National Quality Forum endorsed the UF rate measure but not the target weight measure. We examined the proposed target weight measure and quantified weight gains if UF rate thresholds were applied without treatment time (TT) extension or interdialytic weight gain (IDWG) reduction. METHODS: Data were taken from the 2012 database of a large dialysis organization. Analyses considered 152,196 United States hemodialysis patients. We described monthly patient and dialysis facility target weight achievement patterns and examined differences in patient characteristics across target weight achievement status and differences in facilities across target weight measure scores. We computed the cumulative, theoretical 1-month fluid-related weight gain that would occur if UF rates were capped at 13 mL/h/kg without concurrent TT extension or IDWG reduction. RESULTS: Target weight achievement patterns were stable over the year. Patients who did not achieve target weight (post-dialysis weight ≥ 1 kg above or below target weight) tended to be younger, black and dialyze via catheter, and had shorter dialysis vintage, greater body weight, higher UF rate and more missed treatments compared with patients who achieved target weight. Facilities had, on average, 27.1 ± 9.7% of patients with average post-dialysis weight ≥ 1 kg above or below the prescribed target weight. In adjusted analyses, facilities located in the midwest and south and facilities with higher proportions of black and Hispanic patients and higher proportions of patients with shorter TTs were more likely to have unfavorable facility target weight measure scores. Without TT extension or IDWG reduction, UF rate threshold (13 mL/h/kg) implementation led to an average theoretical 1-month, fluid-related weight gain of 1.4 ± 3.0 kg. CONCLUSIONS: Target weight achievement patterns vary across clinical subgroups. Implementation of a maximum UF rate threshold without adequate attention to extracellular volume status may lead to fluid-related weight gain.

Fluorescent natural organic matter responsible for ultrafiltration membrane fouling: Fate, contributions and fouling mechanisms.

Membrane fouling has been a main obstacle to the success of ultrafiltration (UF) technology. Recently, fluorescent natural organic matter (FNOM), including humic-like substances (HS) and protein-like substances, has been recognized as substances responsible for membrane fouling. In this study, the matrix of FNOM in natural river water was substantially modified by combined coagulation and powdered activated carbon adsorption to enhance the diversity of the FNOM matrix. Fluorescence excitation emission matrix spectroscopy was employed to characterize FNOM components during the UF process. The correlations between FNOM components of the feedwater and membrane fouling were evaluated for the initial period and long-term operation. Reliable correlations of the maximum fluorescence intensity of HS with initial membrane fouling indicated that HS were major foulants in the initial period. Furthermore, the protein-like component exhibited significant correlation with the concentration effect fouling (R2 = 0.6131) and with irreversible fouling (R2 = 0.8711). We found that the fouling mechanism changed from pore obstruction to a protein concentration polarization layer followed by protein cake layer filtration. Total fouling of the UF membrane over long-term operation was alleviated with powdered activated carbon (PAC) adsorption; however, the mitigation of irreversible fouling was dependent on whether PAC adsorbed protein-like substances.

Multi-criteria manufacturability indices for ranking high-concentration monoclonal antibody formulations.

The need for high-concentration formulations for subcutaneous delivery of therapeutic monoclonal antibodies (mAbs) can present manufacturability challenges for the final ultrafiltration/diafiltration (UF/DF) step. Viscosity levels and the propensity to aggregate are key considerations for high-concentration formulations. This work presents novel frameworks for deriving a set of manufacturability indices related to viscosity and thermostability to rank high-concentration mAb formulation conditions in terms of their ease of manufacture. This is illustrated by analyzing published high-throughput biophysical screening data that explores the influence of different formulation conditions (pH, ions, and excipients) on the solution viscosity and product thermostability. A decision tree classification method, CART (Classification and Regression Tree) is used to identify the critical formulation conditions that influence the viscosity and thermostability. In this work, three different multi-criteria data analysis frameworks were investigated to derive manufacturability indices from analysis of the stress maps and the process conditions experienced in the final UF/DF step. Polynomial regression techniques were used to transform the experimental data into a set of stress maps that show viscosity and thermostability as functions of the formulation conditions. A mathematical filtrate flux model was used to capture the time profiles of protein concentration and flux decay behavior during UF/DF. Multi-criteria decision-making analysis was used to identify the optimal formulation conditions that minimize the potential for both viscosity and aggregation issues during UF/DF. Biotechnol. Bioeng. 2017;114: 2043-2056. © 2017 The Authors. Biotechnology and Bioengineering Published by Wiley Perodicals, Inc.

Presión intraperitoneal y ultrafiltración conseguida con diferentes volúmenes intraperitoneales / Intraperitoneal pressure and ultrafiltration achieved with different intraperitoneal volumes

En condiciones fisiológicas el abdomen actúa como una cavidad cerrada cuya presión aumenta de forma proporcional al volumen que contiene. El valor normal de la presión hidrostática intraperitoneal está alrededor de 0 y en pacientes en diálisis peritoneal con volúmenes intraperitoneales de 2 litros puede estar en torno a 12±2 cmH2O. Realizamos un estudio multicéntrico cuantitativo, descriptivo, longitudinal y prospectivo, que incluía a 42 pacientes en programa de diálisis peritoneal con el fin de examinar la presión intraperitoneal y la ultrafiltración conseguida al infundir diferentes volúmenes de líquido de diálisis. Se hicieron dos intercambios consecutivos el primero con 2500 ml y el segundo con 1500 ml con líquido de diálisis con glucosa 2,3% y permanencia de 120 minutos en cada intercambio. De los 42 pacientes el 71,5% eran hombres, con una edad de 59.31±12.23 años y con un índice de masa corporal de 27.01±4.46. La presión intraperitoneal con volumen intraperitoneal 0 fue de 8.2±4.1; con volumen intraperitoneal 2500 ml la presión fue de 13.8±4.4 y la ultrafiltración de 131±206; con volumen intraperitoneal de 1500 ml la presión fue de 11.2±4.2 y la ultrafiltración de 192±145. La ultrafiltración con respecto a la infusión fue del 5,2%±8,2% con volumen de 2500 ml y del 12,8%±9,6% con volumen de 1500 ml. Podemos describir un aumento de la presión intraperitoneal al aumentar el volumen intraperitoneal, al mismo tiempo hemos observado una mayor ultrafiltración con volúmenes más bajos que implicaban a su vez cifras menores de presión (AU)

Under physiological conditions the abdomen acts as a closed cavity whose pressure increases proportionally to the volume contained. The normal value of intraperitoneal hydrostatic pressure is around 0 and in peritoneal dialysis patients with intraperitoneal volumes of 2 liters can be around 12 ± 2 cmH2O. A quantitative, descriptive, longitudinal, and prospective multicentric study was conducted with 42 patients on a peritoneal dialysis program to examine intraperitoneal pressure and ultrafiltration achieved by infusing different volumes of dialysis fluid. Two consecutive exchanges were made: the first with 2500 ml and the second with 1500 ml; both with dialysis fluid with glucose 2.3% and permanence of 120 minutes in each exchange. Of the 42 patients, 71.5% were men, with a mean age of 59.31 ± 12.23 years and a body mass index of 27.01 ± 4.46. The intraperitoneal pressure with intraperitoneal volume 0 was 8.2 ± 4.1; with the intraperitoneal volume of 2500 ml the pressure was 13.8 ± 4.4 and the ultrafiltration of 131 ± 206; with the intraperitoneal volume of 1500 ml the pressure was 11.2 ± 4.2 and the ultrafiltration of 192 ± 145. Ultrafiltration with respect to infusion was 5.2% ±8.2% with a volume of 2500 ml and of 12.8% ±9.6% with a volume of 1500 ml. We can describe an increase in intraperitoneal pressure by increasing the intraperitoneal volume; at the same time we have observed a higher ultrafiltration with lower volumes which, in turn, implied lower values of pressure (AU)

Three-Dimensionally Printed Microfluidic Cross-flow System for Ultrafiltration/Nanofiltration Membrane Performance Testing.

Minimization and management of membrane fouling is a formidable challenge in diverse industrial processes and other practices that utilize membrane technology. Understanding the fouling process could lead to optimization and higher efficiency of membrane based filtration. Here we show the design and fabrication of an automated three-dimensionally (3-D) printed microfluidic cross-flow filtration system that can test up to 4 membranes in parallel. The microfluidic cells were printed using multi-material photopolymer 3-D printing technology, which used a transparent hard polymer for the microfluidic cell body and incorporated a thin rubber-like polymer layer, which prevents leakages during operation. The performance of ultrafiltration (UF), and nanofiltration (NF) membranes were tested and membrane fouling could be observed with a model foulant bovine serum albumin (BSA). Feed solutions containing BSA showed flux decline of the membrane. This protocol may be extended to measure fouling or biofouling with many other organic, inorganic or microbial containing solutions. The microfluidic design is especially advantageous for testing materials that are costly or only available in small quantities, for example polysaccharides, proteins, or lipids due to the small surface area of the membrane being tested. This modular system may also be easily expanded for high throughput testing of membranes.

Comparison of concentration methods for rapid detection of hookworm ova in wastewater matrices using quantitative PCR.

Hookworm infection contributes around 700 million infections worldwide especially in developing nations due to increased use of wastewater for crop production. The effective recovery of hookworm ova from wastewater matrices is difficult due to their low concentrations and heterogeneous distribution. In this study, we compared the recovery rates of (i) four rapid hookworm ova concentration methods from municipal wastewater, and (ii) two concentration methods from sludge samples. Ancylostoma caninum ova were used as surrogate for human hookworm (Ancylostoma duodenale and Necator americanus). Known concentration of A. caninum hookworm ova were seeded into wastewater (treated and raw) and sludge samples collected from two wastewater treatment plants (WWTPs) in Brisbane and Perth, Australia. The A. caninum ova were concentrated from treated and raw wastewater samples using centrifugation (Method A), hollow fiber ultrafiltration (HFUF) (Method B), filtration (Method C) and flotation (Method D) methods. For sludge samples, flotation (Method E) and direct DNA extraction (Method F) methods were used. Among the four methods tested, filtration (Method C) method was able to recover higher concentrations of A. caninum ova consistently from treated wastewater (39-50%) and raw wastewater (7.1-12%) samples collected from both WWTPs. The remaining methods (Methods A, B and D) yielded variable recovery rate ranging from 0.2 to 40% for treated and raw wastewater samples. The recovery rates for sludge samples were poor (0.02-4.7), although, Method F (direct DNA extraction) provided 1-2 orders of magnitude higher recovery rate than Method E (flotation). Based on our results it can be concluded that the recovery rates of hookworm ova from wastewater matrices, especially sludge samples, can be poor and highly variable. Therefore, choice of concentration method is vital for the sensitive detection of hookworm ova in wastewater matrices.

Beneficios del descanso peritoneal / Benefits of peritoneal rest

Introducción: Valorar si el descanso peritoneal, de al menos un día semanal, ha supuesto mejoras en la rehabilitación de los pacientes y el impacto clínico que puede suponer. Nos planteamos además cuantificar el beneficio económico. Material y Método: Se realizó un estudio longitudinal, retrospectivo, descriptivo. De los pacientes atendidos en nuestra unidad desde el 1 de enero de 2014 al 31 de diciembre de 2014, se estudiaron los pacientes que cumplieran todo el año de seguimiento y que no procedieran de otras técnicas de depuración como la hemodiálisis o trasplante renal. La muestra de estudio estuvo compuesta por 40 pacientes, de los que 21 tuvieron prescrito al menos 1 día semanal de descanso peritoneal y 19 pacientes sin descanso. Se recogieron las siguientes variables al inicio del periodo de estudio y a los 12 meses: Variables demográficas, variables relacionadas con el estado de volumen, datos clínicos relacionados con la técnica, se pasó una encuesta de satisfacción a todos los pacientes estudiados, y se recogieron los importes del coste mensual de cada tipo de tratamiento. Resultados: Las diferencias iniciales entre los grupos, eran esperables ya que son los valores en los cuales se ha basado la prescripción del día de descanso. La exposición a la glucosa, al comienzo y al final fue menor en el grupo con descanso. Al año, no se encontró diferencias en los parámetros estudiados. Una encuesta de satisfacción nos reveló a que dedican los pacientes el día de descanso y los que no lo tienen a que lo dedicarían. Conclusiones: El descanso peritoneal no ha supuesto una peor evolución de los parámetros clínicos estudiados al año de seguimiento, cumpliendo las recomendaciones de adecuación de diálisis de las guías clínicas. La exposición a la glucosa, aun sin llegar a ser significativa por la duración del estudio, ha sido menor en el grupo con descanso. El día de descanso ha facilitado a los pacientes mejorar su rehabilitación social principalmente. Los días de descanso han supuesto un ahorro de al menos 13,33% en la factura mensual (AU)

Introduction: To assess whether the peritoneal rest at least one day a week has led to improvements in the rehabilitation of patients, and the clinical impact that can be achieved. We also propose to quantify the economic benefit. Material and methods: A longitudinal, retrospective, descriptive study was conducted. Of those patients seen in our unit from 1 January 2014 to 31 December 2014, patients who fulfilled all the monitoring year and that at the same time they were not subjected to other purification techniques such as dialysis or transplantation kidney were studied. The study sample was composed of 40 patients, of whom 21 had prescribed at least 1 weekly day of peritoneal rest, and 19 patients without rest. The following variables at baseline and 12 months of the study period were recorded: Demographic variables, variables related to volume status, clinical data related to the technique and data related to a satisfaction survey, as well as the amounts of the monthly cost of each type of treatment. Resultados: The initial differences between the groups were expected since they are the values on which is based the prescription of the rest day. Exposure to glucose at the beginning and the end was lower in the group with rest. At one year, no differences in the studied parameters were found. A satisfaction survey revealed to us the activity that patients spend the rest day, as well as the activity that would perform those who not rest. Conclusiones: The peritoneal rest has not meant a worse outcome of the clinical parameters studied at one year, fulfilling the recommendations of dialysis adequacy of the guidelines. Although not statistically significant for the duration of the study, exposure to glucose was lower in the group with rest. The rest day has mainly provided to patients to improve their social rehabilitation. Rest days have generated savings on the monthly bill of 13.33% (AU)

Análisis de la sobrecarga del cuidador del paciente en diálisis peritoneal / Analysis of caregiver burden in peritoneal dialysis patients

Introducción: Un hecho diferencial de la diálisis peritoneal ambulatoria es la necesidad de colaboración de un cuidador principal que se responsabiliza del tratamiento del paciente. Esto unido al carácter crónico de esta patología y posible dependencia del paciente provoca cambios en el estilo de vida del cuidador principal siendo por tanto, una persona expuesta a la sobrecarga. Objetivo: Identificar el grado de sobrecarga de los cuidadores de pacientes en diálisis peritoneal ambulatoria en el Hospital Reina Sofía de Córdoba y su relación con la calidad de vida y la dependencia del paciente. Pacientes y métodos: Se realizó un estudio observacional descriptivo y transversal. Se estudiaron 18 pacientes en tratamiento con diálisis peritoneal ambulatoria y sus respectivos cuidadores. Se incluyó a todos los cuidadores y pacientes que aceptaron colaborar, previo consentimiento informado. Se utilizó el cuestionario SF-36 para evaluar la calidad de vida del paciente junto con el test de Zarit y un cuestionario de sobrecarga de los cuidadores de pacientes en diálisis peritoneal ambulatoria. Con éste último, también se identificó el nivel de dependencia del enfermo desde el criterio del cuidador. Resultados: Respecto a la calidad de vida, se encuentra una disminución leve de algunas de las dimensiones de la población general para la misma edad. No se encontró sobrecarga en la mayoría de los cuidadores principales con ninguno de los instrumentos usados. Se encontró una correlación directa entre ambos instrumentos. En cuanto al nivel de dependencia, un 83 % de pacientes eran independientes y un 17 % de pacientes eran dependientes. Conclusión: A la vista de estos resultados, podemos concluir que, al menos en la muestra estudiada se encuentra una baja proporción de cuidadores con sobrecarga. De igual forma, los pacientes presentan un nivel bajo de dependencia con una CVRS similar a la población general de referencia excepto en la función física (AU)

Introduction: A differential fact ambulatory peritoneal dialysis is the need for collaboration of a primary caregiver who is responsible for the patient’s treatment. This coupled with the chronic nature of this disease and possible dependence of the patient causes changes in the lifestyle of the primary caregiver being therefore a person exposed to overload. Objective: To identify the degree of overload of carers of patients in ambulatory peritoneal dialysis at the Reina Sofia Hospital in Cordoba and its relationship to quality of life and dependence of the patient. Patients and Methods: A descriptive and cross-sectional study. We studied 18 patients treated with continuous ambulatory peritoneal dialysis and their caregivers. We included all caregivers and patients who agreed to participate, prior informed consent. The SF-36 questionnaire was used to evaluate the quality of life of patients with test Zarit and questionnaire overload caregivers of patients in ambulatory peritoneal dialysis. With the latter, also it identified the level of dependence of the patient from the judgment of the caregiver. Results: Regarding the quality of life, there is a slight decrease in some of the dimensions of the general population for the same age. No overload found in most primary caregivers with any of the instruments used. A direct correlation was found between the two instruments. Regarding the level of dependence, 83% of patients were independent and 17% of patients were dependent. Conclusion: In view of these results, we can conclude that, at least in the sample is a low proportion of caregivers overload. Likewise, patients have a low level of dependence similar to the general population reference HRQOL except in physical function (AU)

Use of Enterococcus faecalis and Bacillus atrophaeus as surrogates to establish and maintain laboratory proficiency for concentration of water samples using ultrafiltration.

The U.S. Environmental Protection Agency's (EPA) Water Laboratory Alliance (WLA) currently uses ultrafiltration (UF) for concentration of biosafety level 3 (BSL-3) agents from large volumes (up to 100-L) of drinking water prior to analysis. Most UF procedures require comprehensive training and practice to achieve and maintain proficiency. As a result, there was a critical need to develop quality control (QC) criteria. Because select agents are difficult to work with and pose a significant safety hazard, QC criteria were developed using surrogates, including Enterococcus faecalis and Bacillus atrophaeus. This article presents the results from the QC criteria development study and results from a subsequent demonstration exercise in which E. faecalis was used to evaluate proficiency using UF to concentrate large volume drinking water samples. Based on preliminary testing EPA Method 1600 and Standard Methods 9218, for E. faecalis and B. atrophaeus respectively, were selected for use during the QC criteria development study. The QC criteria established for Method 1600 were used to assess laboratory performance during the demonstration exercise. Based on the results of the QC criteria study E. faecalis and B. atrophaeus can be used effectively to demonstrate and maintain proficiency using ultrafiltration.

Protein-bound solute removal during extended multipass versus standard hemodialysis.

BACKGROUND: Multipass hemodialysis (MPHD) is a recently described dialysis modality, involving the use of small volumes of dialysate which are repetitively recycled. Dialysis regimes of 8 hours for six days a week using this device result in an increased removal of small water soluble solutes and middle molecules compared to standard hemodialysis (SHD). Since protein-bound solutes (PBS) exert important pathophysiological effects, we investigated whether MPHD results in improved removal of PBS as well. METHODS: A cross-over study (Clinical Trial NCT01267760) was performed in nine stable HD patients. At midweek a single dialysis session was performed with either 4 hours SHD using a dialysate flow of 500 mL/min or 8 hours MPHD with a dialysate volume of 50% of estimated body water volume. Blood and dialysate samples were taken every hour to determine concentrations of p-cresylglucuronide (PCG), hippuric acid (HA), indole acetic acid (IAA), indoxyl sulfate (IS), and p-cresylsulfate (PCS). Dialyser extraction ratio, reduction ratio, and solute removal were calculated for these solutes. RESULTS: Already at 60 min after dialysis start, the extraction ratio in the hemodialyser was a factor 1.4-4 lower with MPHD versus SHD, resulting in significantly smaller reduction ratios and lower solute removal within a single session. Even when extrapolating our findings to 3 times 4 h SHD and 6 times 8 h MPHD per week, the latter modality was at best similar in terms of total solute removal for most protein-bound solutes, and worse for the highly protein-bound solutes IS and PCS. When efficiency was calculated as solute removal/litre of dialysate used, MPHD was found superior to SHD. CONCLUSION: When high water consumption is a concern, a treatment regimen of 6 times/week 8 h MPHD might be an alternative for 3 times/week 4 h SHD, but at the expense of a lower total solute removal of highly protein-bound solutes.

Microfiltration of skim milk and modified skim milk using a 0.1-µm ceramic uniform transmembrane pressure system at temperatures of 50, 55, 60, and 65°C.

Increasing the temperature of microfiltration (MF) to >50°C may allow for operation at higher fluxes and reduce the bacterial growth during MF. However, there is a concern that operating at higher temperatures could cause calcium phosphate precipitation that would lead to membrane fouling. Our objective was to determine the effect of operating a 0.1-µm ceramic uniform transmembrane pressure MF unit at temperatures of 50, 55, 60, and 65°C on membrane fouling and serum protein (SP) removal from skim milk with and without removal of low-molecular-weight soluble milk components by ultrafiltration (UF) before MF at a flux of 54kg/m(2) per hour. For each replicate, 1,000kg of pasteurized skim milk was split into 2 batches. One batch was ultrafiltered (with diafiltration) to remove an average of 89±2% of the lactose and a percentage of the soluble calcium and phosphorus. The retentate from UF was diluted back to the protein concentration of skim milk, creating the diluted UF retentate (DUR). On subsequent days, both the DUR and skim milk were run on the MF unit with the flux maintained at 54kg/m(2) per hour and a concentration factor of 3× and the system run in recycle mode. The temperature of MF was increased in 5°C steps from 50 to 65°C, with a 1-h stabilization period after each increase. During the run, transmembrane pressure was monitored and permeate and retentate samples were taken and analyzed to determine if any changes in SP, calcium, or phosphorus passage through the membrane occurred. Increasing temperature of MF from 50 to 65°C at a flux of 54kg/m(2) per hour did not produce a large increase in membrane fouling when using either skim milk or a DUR as the MF feed type as measured by changes in transmembrane pressure. Increasing the temperature to 65°C only caused a slight reduction in calcium concentration in the permeate (11±3%) that was similar between the 2MF feed types. Increasing processing temperature reduced the percentage of SP removal by the process, but the increased temperature also caused a decrease in casein contamination in the permeate with no evidence of membrane fouling.

Identifying polyvinylidene fluoride ultrafiltration membrane fouling behavior of different effluent organic matter fractions using colloidal probes.

The interaction forces between effluent organic matter (EfOM) fractions and membrane were measured by atomic force microscopy in conjunction with self-made membrane material colloidal probes. The inter-EfOM-fraction and intra-EfOM-fraction interactions were investigated using corresponding EfOM-fraction-coated colloidal probe. We combined this analysis with corresponding fouling experiments to identify the EfOM fractions responsible for polyvinylidene fluoride (PVDF) ultrafiltration membrane fouling. Results show that hydrophilic and hydrophobic fractions were the dominant fractions responsible for membrane fouling and flux decline in the initial and later filtration stages, respectively, which was mainly attributed to the stronger PVDF-hydrophilic fraction and intra-hydrophobic-fraction interaction forces. This phenomenon, in conjunction with the fact that each interaction force of PVDF-EfOM fraction was stronger than corresponding intra-EfOM-fraction force, suggests that the elimination of the PVDF-hydrophilic fraction interaction force is the best strategy for controlling EfOM fouling. Moreover, the inter-EfOM-fraction interaction force was mainly controlled by the corresponding intra-EfOM-fraction interaction forces. And, while the membrane-EfOM fraction and intra-EfOM-fraction interactions for each type of EfOM fraction are equivalent, the EfOM fractions with the molecular weight smaller than the molecular weight cutoff of the membranes used were mainly responsible for membrane fouling rather than the relatively high-molecular-weight fractions.

[Dialysis and ultrafiltration therapy in patients with cardio-renal syndrome: recommendations of the working group "heart-kidney" of the German Cardiac Society and the German Society of Nephrology]. / Dialyse- und Ultrafiltrationsverfahren bei kardio-renalem Syndrom. Empfehlung der Arbeitsgemeinschaft "Herz--Niere" der Deutschen Gesellschaft für Kardiologie--Herz- und Kreislaufforschung e.V. und der Deutschen Gesellschaft für Nephrologie e.V.

Renal failure is common in patients with severe heart failure. This complex pathophysiological interaction has been classified as cardio-renal syndrome. In these patients hydropic decompensation is the main cause of hospitalization. In patients with refractory heart failure, characterized by diuretic resistance and congestion due to volume overload, ultrafiltration has to be considered. In acute decompensated heart failure with worsening of renal function, extracorporeal ultrafiltration is the preferred treatment modality. On the other hand, patients suffering from chronic decompensated heart failure, particularly patients with ascites, will profit from the treatment specific advantages of peritoneal ultrafiltration. Prerequisite for an optimized care of patients with cardio-renal syndrome is the close collaboration among intensive care doctors, cardiologists and nephrologists.

Robustness of nanofiltration for increasing the viral safety margin of biological products.

In this study, the virus-removal capacity of nanofiltration was assessed using validated laboratory scale models on a wide range of viruses (pseudorabies virus; human immunodeficiency virus; bovine viral diarrhea virus; West Nile virus; hepatitis A virus; murine encephalomyocarditis virus; and porcine parvovirus) with sizes from 18 nm to 200 nm and applying the different process conditions existing in a number of Grifols' plasma-derived manufacturing processes (thrombin, α1-proteinase inhibitor, Factor IX, antithrombin, plasmin, intravenous immunoglobulin, and fibrinogen). Spiking experiments (n = 133) were performed in process intermediate products, and removal was subsequently determined by infectivity titration. Reduction Factor (RF) was calculated by comparing the virus load before and after nanofiltration under each product purification condition. In all experiments, the RFs were close to or greater than 4 log10 (>99.99% of virus elimination). RF values were not significantly affected by the process conditions within the limits assayed (pH, ionic strength, temperature, filtration ratio, and protein concentration). The virus-removal capacity of nanofiltration correlated only with the size of the removed agent. In conclusion, nanofiltration, as used in the manufacturing of several Grifols' products, is consistent, robust, and not significantly affected by process conditions.

A reference equation for objectively adjusting dwell volume to obtain more ultrafiltration in daily practice of peritoneal dialysis.

OBJECTIVES: Few studies mention how to objectively adjust peritoneal dialysis (PD) dwell volume for adult continuous ambulatory peritoneal dialysis (CAPD) patients. We proposed a reference equation composed of parameters from the peritoneal equilibrium test (PET) for adjusting daily dialysate dwell volume to obtain more ultrafiltration volume. Better fluid control could reduce more fluid overload-related complications. DESIGN: We used body mass index, waist circumference, intraperitoneal pressure, and other parameters from peritoneal equilibrium test to compose a reference equation for fine-tuning daily dwell volume. PATIENTS AND SETTING: Eighty-eight PD patients in one center with laboratory data collected during half-yearly PET evaluations were enrolled. Instilled dialysate was composed of 2.57% glucose PD fluid, either 1500 ml or 2000 ml in volume. In addition to other demographic data, intraperitoneal pressure (IPP) was also measured twice in the supine position four hours apart. We applied statistical multivariate techniques of discrimination analysis and logistic regression to verify the most feasible and optimal formula to determine infill volumes for patients. RESULTS: We determined a novel formula for calculating daily dialysate dwell volume, Z: Z = (0.523 x waist circumference) + (0.852 x body mass index), derived from rotating axes to obtain an accurate prediction rate of 80.68% using the multivariate approach. CONCLUSION: The novel formula used objective, real-time parameters for determining appropriate dwell volumes for PD patients to optimize maximal ultrafiltration volumes and reduce subjective abdominal discomfort. The novel formula makes frequent adjustment of daily dwell volume by physicians or patients easy to calculate.