Pruritus in hemodialysis patients: The problem remains

Pruritus is still one of the most common and disturbing symptoms of end-stage renal disease. The objective of this study is to analyze the prevalence of pruritus in hemodialysis patients and the possible factors implicated in its genesis. In a cross-sectional study, 101 patients on hemodialysis at our center were screened for pruritus. The relationship of various factors with pruritus was evaluated. Of the 101 patients included, 31(30.7%) had pruritus at the time of examination. Patients with pruritus were significantly older than those without pruritus (P=0.0027). Pruritus tended to be more prevalent in patients undergoing dialysis 3 times a week than in those undergoing daily dialysis, but the difference did not reach statistical significance (P=0.0854). Lower transferrin saturation levels were found in patients with pruritus than in those without pruritus (P=0.0144). C-reactive protein levels were significantly higher in patients with pruritus than in those without pruritus (P=0.0013). There was no significant difference between the groups in the levels of the other inflammatory biomarkers measured. However, there was a tendency toward a correlation between the levels of α-1-glycoprotein and the intensity of pruritus (P=0.0834). Our results suggest a possible relationship of the inflammatory response upregulation to pruritus. Additionally, there was a positive relationship between pruritus and iron deficiency, possibly associated with inflammatory elevation of hepcidin. A better understanding of the factors implicated in the genesis of pruritus related to end-stage renal disease is crucial in the development of more effective treatments for this symptom.     

Grain subdivision and recrystallization in oligocrystalline tantalum during cold swaging and subsequent annealing

A coarse-grained ingot of high-purity tantalum was deformed by swaging at room temperature to a strain of 1.28. During annealing at 900°C for 30 min two neighboring grains were observed to behave quite differently. Electron backscattering diffraction (EBSD) results show noticeable differences in terms of the misorientations developed in both grains. The grain developing larger misorientations recrystallized much more readily than the other. The result is interpreted in terms of the differences in grain subdivision into strongly misoriented regions.     

Semi-analytical derivation of approximate non-linear eigenvalues and eigenvectors for general non-linear MDOF systems

This work introduces a novel theoretical formulation for the evaluation of approximate eigenvalues and eigenvectors for general non-linear MDOF systems using the so-called “approximate non-linear mode evaluation” (ANME) method. The approach is based on analytically derived quasi-linear expressions which relate the change in modal parameters to physical non-linear elements that can be added anywhere in the system. Subject to assuming that the change in the mode shape is small, expressions for non-linear eigenvalues and eigenvectors become fully determined for a general MDOF system, even within typical experimental constraints. The errors arising from this assumption can be minimized via an iterative procedure. Preliminary results indicate that the rate of convergence is quite fast for systems with medium to high damping but more effort is required for lightly damped systems. The derived expressions provide a theoretical basis for observations made by previous researchers from an inspection of their experimental and/or numerical results: these indicate that an invariant relationship exists between a non-linear eigenvalue and its associated modal response.     

Regioselective analysis of the fatty acid composition of triacylglycerols with conventional high-performance liquid chromatography

A new method for regioselective analysis of triacyglycerols via conventional high-performance liquid chromatography (HPLC) has been developed. The method is simple and avoids the time-consuming purification processes normally characteristics of regioselective analyses. The procedure utilizes an sn-1,3-specific lipase from Rhizopus arrhizus to deacylate the fatty acid residues located at the sn-1 and sn-3 positions of triacylglycerols. The fatty acid residues esterified at the sn-2 position are determined by subtraction of the results of the sn-1,3 analysis from an overall composition analysis based on complete saponification of the original sample. The fatty acid mixtures are converted to p-bromophenacyl esters and analyzed using conventional HPLC techniques. The analytical procedure has been verified using a standard structured triacylglycerol. The analytical results for three edible vegetable oils are compared with those obtained via the method proposed by P.J. Williams and co-workers.     

Alumina–Aluminide Alloys (3A) Technology: I, Model Development

The general reaction behavior of the 3A process under the thermal explosion mode of synthesis has been investigated via a continuum model. The continuum model uses mass and energy balances to predict temperature difference ( T _s,avg− T _f) curves, as well as profile curves of the reactant conversions and sample temperature. In particular, the effect of the dimensionless parameters associated with the rate of local heat generation (β, the thermicity factor), the activation energy (γ, the Arrhenius number), the rate of heat redistribution (α, the modified thermal diffusivity), the rate of heat transfer by convection (Bi, the Biot number or convective heat transfer parameter), and the rate of heat transfer by radiation (Ω, the radiative heat transfer parameter) were investigated. Conditions to control the reaction process, which should produce high-density final products, were determined. It was found that the overall maximum temperature may be reduced for high γ, low β, high α, and high Bi and Ω. In terms of processing conditions, this may be obtained by reducing the initial reactant concentrations, optimizing the particle size, using small sample sizes and high compaction pressure, and increasing the heat loss by using a high thermal conductivity inert gas.     

Immobilized lipase reactors for modification of fats and oils—A review

This review focuses on the use of immobilized lipase technology to effect hydrolysis, ester synthesis, and interesterification reactions. The various immobilization procedures, reactor configurations, and process considerations are all reviewed and discussed.     

Relationship between proteolysis and angiotensin-I-converting enzyme inhibition in different cheeses

The inhibition of angiotensin-I-converting enzyme (ACE) by the ethanol (70%)-soluble fraction (ESF) from different cheeses was analysed with an extract from rabbit lung acetone powder as enzyme source and 2-furanacryloyl-1-phenylalanylglycylglycine (FAPGG) as substrate. Proteolysis was assessed by a spectroscopic o-phthaldialdehyde (OPA) assay of the pH 4.6-soluble fraction and ESF. Peptides in the ESF were separated by reverse phase-HPLC. The traditional Norwegian cheese Gamalost had per unit cheese weight higher ACE inhibition potential than Brie, Roquefort and Gouda-type cheese, likely due to the combination of highest protein content and most extensive proteolysis providing a high content of ACE inhibitory peptides. However, ACE-inhibition expressed as IC₅₀ per unit peptide concentration from ESF assessed by the OPA-assay was highest for Kesam, a Quark-type cheese with a low degree of proteolysis.     

Effects of early and late antihypertensive treatment on extracellular matrix proteins and mononuclear cells in uninephrectomized SHR

The efficacy of an early and late treatment with the angiotensin converting enzyme inhibitor lisinopril or the angiotensin II receptor blocker ICI D8731 was investigated in uninephrectomized spontaneously hypertensive rats (SHR). Rats that underwent uninephrectomy (UNX) at six weeks of age were randomly assigned to receive no treatment, lisinopril shortly after UNX, lisinopril starting 16 weeks after UNX, ICI D8731 shortly after UNX, and ICI D8731 starting 16 weeks after UNX. Blood pressure was normalized with both treatments. After six months inulin clearance was not significant different, while proteinuria and prevalence of interstitial fibrosis were significantly reduced in all treatment groups. Immunohistochemical studies revealed an interstitial, periglomerular and perivascular increase of extracellular matrix proteins in all rats, but a markedly reduced expression of collagen I, IV and fibronectin after early and late treatment compared to untreated controls. We found a significant reduction of infiltrating macrophages and T-lymphocytes in all treated animals compared to untreated controls after 2, 4 and 6 months. Especially early treatment was associated with lower numbers of infiltrating cells. Both treatments reduced proliferation of tubular and interstitial cells. There were no striking differences with regard to nephroprotection between the ACE inhibitor and angiotensin II receptor blocker. These findings show that both treatments have beneficial effects on kidney structure and function. They suggest that both ACE inhibition and angiotensin II blockade decrease renal cell proliferation and suppress the infiltration of mononuclear cells that may trigger expression of extracellular matrix proteins and progressive nephrosclerosis.     

Rent tax and filtering charge

In the Netherlands proposals for a rent tax or filtering charge have a long history. This article outlines the nature of such proposals and argues against their introduction.