Beyond ultrapure hemodialysis: A necessary and achievable goal

Survival of chronic hemodialysis patients is worse than that of many patients with cancers or severe infections. An important cause of chronic inflammation is impurities infused into patients during dialysis. Definitions of dialysis purity have been narrow and focused on metals in dialysate water and on bacterial contaminants. There is no standard for priming fluids or toxins released directly into blood from inside the extracorporeal circuit. We propose a much broader standard of dialysis purity that also includes phthalate metabolites, bisphenols, spalled particles, and other contaminants from dialysis machines, filters, and bloodlines. Standards must include new methods for measuring bacteriological contaminants in addition to colony‐forming units and endotoxin determinations. These include the sensitive silkworm larva plasma test that detects peptidoglycan that is missed by endotoxin tests and standards for newly detected small molecular bacterial detritus. Current levels for “standard” bacteriological contaminants are woefully inadequate and should be increased. New standards for contamination with plasticizers and spallation are also necessary. Studies with ultrapure dialysis have shown almost immediate patient benefits with increased well‐being and stabilization of the cardiovascular system during and between dialyses. Intermediate effects include lower C‐reactive protein levels, better response to erythropoietin, increased appetite, and improved nutrition. Over the years, amyloidosis and carpal tunnel syndrome have become less common and cardiovascular deaths have decreased. Standards for dialysis purity must be sharpened and expanded and this becomes even more urgent with daily and long nightly hemodialysis. All contaminants received by patients, whether biological, chemical, or physical, must be considered.     

Measurement of Hemodialysis Adequacy in a Changing World

Defining adequacy of dialysis remains an elusive goal. The application of the Kt/V_urea concept to clinical dialysis was a major improvement in trying to define a dialysis dose. Intuitively, the Kt/V concept makes a great deal of sense: the urea clearance of the dialyzer during dialysis (K), multiplied by the time (t) of dialysis, divided by the patient's urea distribution volume (V) ought to give the best number to compare the efficiency of dialyses that patients receive. There are, however, many pitfalls associated with the whole Kt/V_urea concept.     

膜技术在稀有金属冶炼中的应用

介绍了离子交换膜及压力驱动膜在稀土，钨，铼的提取冶金工艺中的应用，涉及的膜过程包括膜电解，扩散渗析，电渗析，反渗透，纳滤，超滤。归纳了膜分离技术的6大优点及在冶金领域可以发挥重大作用的4个方面，指出了膜技术在稀有金属领域中的广阔应用前景。     

Psychological Symptoms Are Greater in Caregivers of Patients on Hemodialysis Than Those of Peritoneal Dialysis

Background: The purpose of this study was to evaluate and compare psychosocial characteristics in caregiving relatives (caregivers) of hemodialysis (HD) and peritoneal dialysis (PD) patients. Methods: Thirty‐three caregivers (17 women, 16 men) of HD patients, 27 caregivers (11 women, 16 men) of PD patients, and a control group of 49 subjects who do not care for family members with chronic illness (23 women, 26 men) are included in this study. The brief symptom inventory (BSI), social disability schedule (SDS), and brief disability questionnaire (BDQ) were used for the psychosocial evaluation. Results: The mean age, men‐to‐women ratios, duration of education, and distribution of marital status did not differ significantly among the three groups. In addition, dialysis duration and distribution of caregiver type were not different between the HD and PD groups. Although the mean global severity index scores of the three groups were similar, somatization and depression scores from BSI subitems were greater in the HD group than the scores of the PD and control groups. Although the mean SDS and BDQ scores were higher in the HD group, the differences did not achieve statistical significance. BSI subitems such as somatization, obsession–compulsion, interpersonal sensitivity, depression, and anxiety were positively correlated among themselves. Hostility and somatization were negatively correlated with age and education, respectively. Nevertheless, somatization was positively correlated with age. Social disability was negatively correlated with duration of education. Conclusion: Somatization and depression are greater in the caregivers of center HD patients compared to PD and control groups. According to the findings of this study, we suggest that caregiving family members of dialysis patients especially on HD also should be evaluated for psychosocial problems and supported as needed. Further studies are needed to explore whether psychosocial parameters of caregivers predict outcomes for caregivers and patients.     

Gustatory sweating recurring on peritoneal dialysis but resolving during periods of hemodialysis

Gustatory sweating is a rare disorder characterized by profuse sweating on the forehead, face, scalp, and neck occurring soon after ingesting food, which has been reported in diabetic patients. The mechanism is thought to be triggered by taste buds and not gastric stimulation. We report a case where gustatory sweating repeatedly developed on peritoneal dialysis that resolved on periods of hemodialysis. A 32-year-old woman with diabetic end-stage renal disease developed gustatory sweating shortly after beginning continuous ambulatory peritoneal dialysis despite excellent clearances. After 5 months, she changed to hemodialysis for 2 months and noticed complete resolution of her gustatory sweating; however, after her return to peritoneal dialysis 2 months later, her gustatory sweating recurred. While on peritoneal dialysis, she was treated with clonidine, which resulted in improvement but not resolution of her symptoms as had occurred on hemodialysis. Another period on hemodialysis resulted in the resolution of her symptoms that returned again after restarting peritoneal dialysis. Clonidine provided incomplete relief while topical glycopyrrolate was effective and without complications. We report recurrent gustatory sweating on peritoneal dialysis that resolved with hemodialysis. We have no data to suggest that intra-abdominal stimulation played a role, but rather that despite excellent clearances neuropathy may have played a role. Treatment with topical glycopyrrolate may be safe and effective given every third day if clonidine is ineffective.     

Effect of extraction method on chemical composition and functional characteristics of high dietary fibre powders obtained from asparagus by-products

Asparagus (Asparagus officinalis L.) by-products, which represent around 50% of the processed vegetable, are a potential source of dietary fibre. The way that these by-products are treated affects the composition and functional properties of fibre-rich powders. Factors such as treatment intensity, solvent, and drying system were studied. Only the more soluble components (soluble sugars, uronic acids and proteins) showed significant differences. All the fibre-rich powders had high concentrations of TDF (62–77%). The IF/SF proportion decreased with the severity of treatment, in this way increasing the physiological quality of the fibre. Functional properties, namely water-holding capacity (WHC), oil-holding capacity (OHC), solubility (SOL), and glucose dialysis retardation index (GDRI), varied according to the preparation procedure. WHC and GDRI were higher in intensely extracted fibres; due to the effect of thermal processing. WHC showed values (11–20 ml water/g powder) similar to those described for other agricultural by-products, but OHC and GDRI were much higher (5–8 ml oil/g powder and 25–45%, respectively). These properties make fibre-rich powders from asparagus by-products a valuable source of dietary fibre to be included in the formulation of fibre-enriched foods.     

Assessment of subjective and hemodynamic tolerance of different high‐ and low‐flux dialysis membranes in patients undergoing chronic intermittent hemodialysis: A randomized controlled trial

Clinical experience and experimental data suggest that intradialytic hemodynamic profiles could be influenced by the characteristics of the dialysis membranes. Even within the worldwide used polysulfone family, intolerance to specific membranes was occasionally evoked. The aim of this study was to compare hemodynamically some of the commonly used polysulfone dialyzers in Switzerland. We performed an open‐label, randomized, cross‐over trial, including 25 hemodialysis patients. Four polysulfone dialyzers, A (Revaclear high‐flux, Gambro, Stockholm, Sweden), B (Helixone high‐flux, Fresenius), C (Xevonta high‐flux, BBraun, Melsungen, Germany), and D (Helixone low‐flux, Fresenius, Bad Homburg vor der Höhe, Germany), were compared. The hemodynamic profile was assessed and patients were asked to provide tolerance feedback. The mean score (±SD) subjectively assigned to dialysis quality on a 1–10 scale was A 8.4 ± 1.3, B 8.6 ± 1.3, C 8.5 ± 1.6, D 8.5 ± 1.5. Kt/V was A 1.58 ± 0.30, B 1.67 ± 0.33, C 1.62 ± 0.32, D 1.45 ± 0.31. The low‐ compared with the high‐flux membranes, correlated to higher systolic (128.1 ± 13.1 vs. 125.6 ± 12.1 mmHg, P < 0.01) and diastolic (76.8 ± 8.7 vs. 75.3 ± 9.0 mmHg; P < 0.05) pressures, higher peripheral resistance (1.44 ± 0.19 vs. 1.40 ± 0.18 s × mmHg/mL; P < 0.05) and lower cardiac output (3.76 ± 0.62 vs. 3.82 ± 0.59 L/min; P < 0.05). Hypotension events (decrease in systolic blood pressure by >20 mmHg) were 70 with A, 87 with B, 73 with C, and 75 with D (P < 0.01 B vs. A, 0.05 B vs. C and 0.07 B vs. D). The low‐flux membrane correlated to higher blood pressure levels compared with the high‐flux ones. The Helixone high‐flux membrane ensured the best efficiency. Unfortunately, the very same dialyzer correlated to a higher incidence of hypotensive episodes.     

Liposome‐Supported Peritoneal Dialysis for the Treatment of Hyperammonemia‐Associated Encephalopathy

Hyperammonemia can lead to cerebral dysfunction, encephalopathy, coma, and death if not treated adequately. The poor prognosis associated with this condition reflects the unmet medical need for effective ammonia‐lowering treatments. Here, the translational potential of liposome‐supported peritoneal dialysis (LSPD), a recently‐developed detoxification strategy for the removal of small ionizable molecules like ammonia, is described. Dialysis fluids supplemented with micrometer‐sized, transmembrane pH‐gradient liposomes are prepared via an innovative, osmotic shock‐based method overcoming sterilization and long‐term stability issues. LSPD is able to sequester ammonia in healthy rats in relation to the injected dose, buffering capacity of the liposomal core, and membrane composition. In a rat model of cirrhosis, LSPD outperforms conventional peritoneal dialysis in lowering plasmatic ammonia levels and attenuating brain edema. LSPD does not trigger any hypersensitive reaction in pigs, a side effect commonly observed upon the injection of colloids in this animal model and in humans. These findings support the development of LSPD for the treatment of hyperammonemia‐induced encephalopathy.     

Time trends in the association of ESRD incidence with area‐level poverty in the US population

The objective of this study was to examine the temporal trends of the association between area‐level poverty status and end‐stage renal disease (ESRD) incidence. We hypothesized that the association between area‐level poverty status and ESRD incidence has increased significantly over time. Patient data from the United States Renal Data System were linked with data from the 2000 and 2010 US census. Area‐level poverty was defined as living in a zip code‐defined area with ≥20% of households living below the federal poverty line. Negative binomial regression models were created to examine the association between area‐level poverty status and ESRD incidence by time period in the US adult population while simultaneously adjusting for the distribution of age, sex, and race/ethnicity within a zip code. Time was categorized as January 1, 1995 through December 31, 2004 (Period 1) and January 1, 2005 through December 31, 2010 (Period 2). The percentage of adults initiating dialysis with area‐level poverty increased from 27.4% during Period 1 to 34.0% in Period 2. After accounting for the distribution of age, sex, and race/ethnicity within a zip code, area‐level poverty status was associated with a 1.24 (95% confidence interval [CI] 1.22, 1.25)‐fold higher ESRD incidence. However, this association differed by time period with 1.04‐fold (95% CI 1.02, 1.05) higher ESRD incidence associated with poverty status for Period 2 compared with the association between ESRD and poverty status in Period 1. Area‐level poverty and its association with ESRD incidence is not static over time.