Identification of fluid overload in elderly patients with chronic kidney disease using bioimpedance techniques.

Diagnosis of fluid overload (FO) in early stage is essential to manage fluid balance of patients with chronic kidney disease (CKD) and to prevent cardiovascular disease (CVD). However, the identification of fluid status in patients with CKD is largely dependent on the physician's clinical acumen. The ratio of fluid overload to extracellular volume (FO/ECV) has been used as a reference to assess fluid status.

Vitamin C overload may contribute to systemic oxalosis in children receiving dialysis.

Background: Malnutrition and anorexia are common in children with chronic kidney disease (CKD) and gastrostomy tubes (GT) as well as nasogastric tubes (NGT) have been recommended to maximize nutritional support. The optimal requirement of vitamin C in children with CKD remains to be defined but oxalate is a breakdown product of vitamin C. Elevated vitamin C intake and bone oxalate were identified in two formula-fed dialyzed children with negative genetic testing for primary hyperoxaluria.

At-line N-linked glycan profiling for monoclonal antibodies with advanced sample preparation and high-performance liquid chromatography.

N-linked glycosylation is a post-translational modification that occurs on many proteins during biosynthesis. The profile of different glycans on the protein is a critical quality attribute of some recombinant biopharmaceutical proteins including monoclonal antibodies (mAbs). Methods for profiling glycan should be robust, fast, and sensitive.

A high-resolution measurement of nucleotide sugars by using ion-pair reverse chromatography and tandem columns.

N-Linked glycosylation is a cellular process transferring sugars from glycosyl donors to proteins or lipids. Biopharmaceutical products widely produced by culturing mammalian cells such as Chinese hamster ovary (CHO) cells are typically glycosylated during biosynthesis. For some biologics, the N-linked glycan is a critical quality attribute of the drugs.

The effect of increased frequency of hemodialysis on vitamin C concentrations: an ancillary study of the randomized Frequent Hemodialysis Network (FHN) daily trial.

Background: Reports on vitamin C in HD patients have shown effects of vitamin C deficiency in association with scurvy symptoms. Dialyzability of water soluble vitamins is high, and substantial losses in those who are dialyzed more frequently were hypothesized. The randomized FHN Daily Trial compared the effects of in-center HD six versus three times per week.

Removal of Protein-Bound Uremic Toxins during Hemodialysis Using a Binding Competitor.

Background And Objectives: Current hemodialysis techniques fail to efficiently remove the protein-bound uremic toxins p-cresyl sulfate and indoxyl sulfate due to their high degree of albumin binding. Ibuprofen, which shares the same primary albumin binding site with p-cresyl sulfate and indoxyl sulfate, can be infused during hemodialysis to displace these toxins, thereby augmenting their removal.

Design, Setting, Participants, & Measurements: We infused 800 mg ibuprofen into the arterial bloodline between minutes 21 and 40 of a conventional 4-hour high-flux hemodialysis treatment.

Ferric pyrophosphate citrate: interactions with transferrin.

There are several options available for intravenous application of iron supplements, but they all have a similar structure:-an iron core surrounded by a carbohydrate coating. These nanoparticles require processing by the reticuloendothelial system to release iron, which is subsequently picked up by the iron-binding protein transferrin and distributed throughout the body, with most of the iron supplied to the bone marrow. This process risks exposing cells and tissues to free iron, which is potentially toxic due to its high redox activity.

A Simplified Sample Preparation Method for the Assessment of Plasma Ascorbic Acid in Clinical Settings.

Background: Vitamin C deficiency is difficult to diagnose on the basis of clinical presentation alone and requires plasma levels for confirmation. Reference laboratories typically specify shipment of plasma on dry ice. This requirement may complicate clinic work flow and delay vitamin C measurement.

Tryptophan and Kynurenine Levels and Its Association With Sleep, Nonphysical Fatigue, and Depression in Chronic Hemodialysis Patients.

Objective: Sleep and mood disorders are common in hemodialysis (HD) patients and the pathophysiology is still unclear. Tryptophan (TRP) and its metabolites may play a prominent role in neural pathways related to sleep, fatigue, and depression. Here, we sought to compare the levels of TRP and its metabolites between HD patients and healthy subjects and examine their association with sleep, fatigue, and depression in HD patients.

Plasma vitamin C levels in ESRD patients and occurrence of hypochromic erythrocytes.

Introduction: The achievement of erythropoiesis in hemodialysis (HD) patients is typically managed with erythropoiesis-stimulating-agents (ESA's) and intravenous iron (IV-iron). Using this treatment strategy, HD patients frequently show an elevated fraction of red blood cells (RBC) with hemoglobin (Hb) content per cell that is below the normal range, called hypochromic RBC. The low Hb content per RBC is the result of the clinical challenge of providing sufficient iron content to the bone marrow during erythropoiesis.

Plasma oxalate levels in prevalent hemodialysis patients and potential implications for ascorbic acid supplementation.

Objectives: Ascorbic acid (AA) supplementation may increase hemoglobin levels and decrease erythropoiesis-stimulating agent dose requirement in patients with end stage renal disease (ESRD). While plasma AA levels >100μM may be supratherapeutic, levels of at least 30μM may be needed to improve wound healing and levels may need to reach 70μM to optimize erythropoiesis. Of concern, oxalate (Ox), an AA metabolite, can accumulate in ESRD.

Improved dialytic removal of protein-bound uraemic toxins with use of albumin binding competitors: an in vitro human whole blood study.

Protein-bound uraemic toxins (PBUTs) cause various deleterious effects in end-stage kidney disease patients, because their removal by conventional haemodialysis (HD) is severely limited by their low free fraction in plasma. Here we provide an experimental validation of the concept that the HD dialytic removal of PBUTs can be significantly increased by extracorporeal infusion of PBUT binding competitors. The binding properties of indoxyl sulfate (IS), indole-3-acetic acid (IAA) and hippuric acid (HIPA) and their binding competitors, ibuprofen (IBU), furosemide (FUR) and tryptophan (TRP) were studied in uraemic plasma.

Cardio-metabolic and immunological impacts of extra virgin olive oil consumption in overweight and obese older adults: a randomized controlled trial.

Background: Both aging and obesity are related to dysregulated immune function, which may be responsible for increased risk of infection and also chronic non-infectious diseases. Dietary lipids have been shown to impact immune and inflammatory responses and cardio-metabolic risk factors. No information on the impact of olive oil on immune responses of overweight and obese older adults is available.

Enhanced Indoxyl Sulfate Dialyzer Clearance with the Use of Binding Competitors.

Background: Indoxyl sulfate is a protein-bound uremic toxin and its dialytic clearance is comparatively low. We propose a method to increase indoxyl sulfate dialytic clearance.

Methods: Human serum albumin, preloaded with indoxyl sulfate, was circulated on the blood side of an F40S dialyzer with single-pass counter-current dialysate flow.

Plasma ascorbic acid concentrations in prevalent patients with end-stage renal disease on hemodialysis.

Objective: To determine the prevalence of vitamin C (ascorbic acid [AA]) deficiency in patients with end-stage renal disease, the effect of supplemental AA on plasma AA concentrations, and the extrinsic and intrinsic factors that affect plasma AA concentrations in this patient population.

Design: In study 1, we compared the effect of hemodialysis (HD) on plasma AA concentrations between patients with low and high pre-HD AA concentrations. In study 2, we analyzed kinetic and nonkinetic factors for their association with increased plasma AA concentrations in patients on maintenance HD.

Transfer of low-molecular weight single-stranded DNA through the membrane of a high-flux dialyzer.

Purpose: Microbial contamination is often present in dialysate used for hemodialysis. Small single-stranded bacterial DNA sequences are capable of activating human inflammatory pathways, through mechanisms that include the Toll-like-receptor 9, and dialysis patients frequently show severe inflammation. Since these molecules have been found in dialysate and in patients' bloodstreams, we studied the potential of low-molecular weight DNA sequences, of the same structure as found in bacteria, to cross from the dialyzer circuit to the blood circuit of a dialysis filter.

Hospitalization and mortality in hemodialysis patients: association with hemoglobin variability.

Background/aims: Hemodialysis patients show complications associated with low or high hemoglobin (Hb), which occur frequently in clinical practice. We sought to determine the clinical importance of these changes in Hb levels.

Methods: From our clinic cohorts, we identified 1,634 who met inclusion criteria for analysis of hospitalization frequency and 1,953 analysis of mortality; many patients were in both groups.

Is vitamin C intake too low in dialysis patients?

Vitamin C has several well-established roles in physiology including synthesis of collagen, carnitine and epinephrine, absorption of dietary iron, and mobilization of storage iron for erythropoeisis. Loss of several of these functions explains the pathology of scurvy, where defective collagen synthesis and anemia are major symptoms. Vitamin C deficiency is very common in dialysis patients and may arise from dialytic vitamin C clearance, restricted intake of vitamin C-rich foods, and increased vitamin C catabolism in vivo from inflammation.

Outcome of acute peritoneal dialysis in northern Tanzania.

Data on the burden of acute kidney injury (AKI) in resource-poor countries such as Tanzania are minimal because of a lack of nephrology services and an inability to recognize and diagnose AKI with any certainty. In the few published studies, high morbidity and mortality are reported. Improved nephrology care and dialysis may lower the mortality from AKI in these settings.

Outcomes of a Latino community-based intervention for the prevention of diabetes: the Lawrence Latino Diabetes Prevention Project.

Objectives: We tested the effectiveness of a community-based, literacy-sensitive, and culturally tailored lifestyle intervention on weight loss and diabetes risk reduction among low-income, Spanish-speaking Latinos at increased diabetes risk.

Methods: Three hundred twelve participants from Lawrence, Massachusetts, were randomly assigned to lifestyle intervention care (IC) or usual care (UC) between 2004 and 2007. The intervention was implemented by trained Spanish-speaking individuals from the community.

Estimation of normal hydration in dialysis patients using whole body and calf bioimpedance analysis.

Prescription of an appropriate dialysis target weight (dry weight) requires accurate evaluation of the degree of hydration. The aim of this study was to investigate whether a state of normal hydration (DW(cBIS)) as defined by calf bioimpedance spectroscopy (cBIS) and conventional whole body bioimpedance spectroscopy (wBIS) could be characterized in hemodialysis (HD) patients and normal subjects (NS). wBIS and cBIS were performed in 62 NS (33 m/29 f) and 30 HD patients (16 m/14 f) pre- and post-dialysis treatments to measure extracellular resistance and fluid volume (ECV) by the whole body and calf bioimpedance methods.