The link of biocompatibility to cytokine production.

Recent studies suggest that chronic inflammation plays a role in the pathogenesis of cardiovascular disease. Cytokines released from jeopardized tissues stimulate the liver to synthesize acute phase proteins, including C-reactive protein (CRP). Baseline levels of CRP in apparently healthy persons or in persons with unstable angina constitute an independent risk factor for cardiovascular events.

ANCA in dialysis patients: a role for bioincompatibility?

Unlabelled: BACKGROUND. Anti-neutrophil cytoplasmic autoantibodies (ANCA) have been described in patients suffering from systemic vasculitis such as Wegener granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome and other pathological conditions. In this paper we report a greater incidence of ANCA in hemodialysis patients as compared to peritoneal dialysis patients, pre-dialytic uremic patients and non-renal patients; a possible role for dialysis bioincompatibility in ANCA generation was also investigated.

Nitric oxide-dependent renal vasodilatation is not altered in rat with rHuEpo-induced hypertension.

Background: Recombinant human erythropoietin (rHuEpo) is the treatment of choice in anemia associated with end-stage renal disease. Its major side effect is hypertension, which occurs in 8-30% of uremic patients. The exact mechanism of rHuEpo-induced hypertension has not been fully elucidated, and several possibilities have been proposed, such as a direct vascular effect of the drug with a shift in the balance of constrictor and relaxing endothelial factors (endothelins and nitric oxide (NO)).

Calcitriol modulates in vivo and in vitro cytokine production: a role for intracellular calcium.

Calcitriol modulates in vivoand in vitro cytokine production: A role for intracellular calcium. Background. Several immunomodulatory properties of calcitriol are currently known, however, only little information is available regarding the in vivo and in vitro effects of calcitriol on cytokine production in chronic renal failure.

Biocompatibility evaluation of polyamide hemofiltration.

Introduction: Postdilution hemofiltration with a polyamide membrane is a renal replacement technique widely used, but very little information is available regarding the biocompatibility of this treatment. In this paper we report the results of an acute study of the biocompatibility of polyamide hemofiltration.

Patients And Methods: Complement activation such as C3a and C5a Des Arg (RIA), granulocyte degranulation like alpha 1 elastase intradialytic increase (ELISA) and the expression of high affinity membrane receptors for IL-2 (anti-TAC) were determined.

Cytokine production in haemodiafiltration: a multicentre study.

Background: Bacterial contamination of dialysate may enhance cytokine production in haemodialysis. We tested the hypothesis that intracellular cytokines could be enhanced in a large group of patients exposed to backfiltration of dialysate over a long period of observation.

Methods: The intracellular cytokine (interleukin-1 receptor antagonist and interleukin-1beta) concentrations in chronic uraemic patients undergoing haemodiafiltration, which is known to be associated with backfiltration (Group II, 12 patients), were compared to those found in patients treated with a modified haemodiafiltration modality without backfiltration (Group I, 16 patients), in patients shifted from one modality to the other (Group III, 27 patients) and in 10 patients on haemodialysis (Group IV) in a 1-year multicentre study.

Calcitriol oral therapy for the prevention of secondary hyperparathyroidism in patients with predialytic renal failure.

Secondary hyperparathyroidism is a common feature of chronic renal failure and vitamin D deficiency plays an important role in the development of this abnormality. Several therapeutical calcitriol schedules have been used in treating uremic hyperparathyroidism but recently oral boluses have been proposed as more effective. In this study we compare the efficacy of three different oral calcitriol regimens in suppressing iPTH secretion in predialytic chronic renal failure.

Kinetics and Thermodynamics of Binding of a Model Tripeptide to Teicoplanin and Analogous Semisynthetic Antibiotics.

The thermodynamics and kinetics of binding of model tripeptides epsilon-N-acetyl-alpha-N-dansyl-L-Lys-D-Ala-D-Ala (ADLAA) or alpha-N,epsilon-N-diacetyl-L-Lys-D-Ala-D-Ala (AALAA) to teicoplanin (1a) and a series of semisynthetic derivatives with (1b-f) or devoid of (2a-g) the glycidic side arms and modified at the terminal amino acids of the peptide backbone have been studied by fluorescence or UV spectroscopy. The binding process is suggested to occur via a two-step mechanism. The first, fast process is likely governed by an electrostatic interaction between the C- and N-termini of the peptide chain of the substrate and of the antibiotic, respectively, while the second slower one, accounts for the formation of the hydrogen bonds responsible of the major contribution to the overall binding energy.

Acute suppression of parathyroid activity during hemofiltration.

Hemofiltration (HF) induces a significant reduction in parathormone (PTH). This effect is related not only to the convective removal of PTH molecules but also to the biological suppression of parathyroid glands by plasma-ionized calcium (iCa) increase. The acute inhibitory effect on parathyroid gland activity, ionized calcium mass balance, phosphate kinetics and intact PTH (PTHi) dialytic removal during post-dilution polyamide HF were studied in 31 chronic uremic patients.

New semisynthetic glycopeptides MDL 63,246 and MDL 63,042, and other amide derivatives of antibiotic A-40,926 active against highly glycopeptide-resistant VanA enterococci.

A series of amide derivatives of natural glycopeptide A-40,926 (A), its 6B-methyl ester (MA) and 6B-decarboxy-6B-hydroxymethyl derivative (RA) were prepared with the aim of obtaining activity against glycopeptide-resistant enterococci. These compounds are structurally related to a class of amides of 34-de(acetylglucosaminyl)-34-deoxy teicoplanin which showed interesting activity against strains of Enterococcus faecalis and E. faecium highly resistant to both vancomycin and teicoplanin.

Protein layer on hemodialysis membranes: a new immunohistochemistry technique.

In order to investigate the nature of the protein layer deposited on hemodialysis membranes we developed a direct immunohistochemical technique using fluoresceinated antibodies to plasma membranes. Fifteen patients on regular dialytic treatment were dialyzed with CU, HE, PAN, PS and PMMA and the dialyzers analyzed at the end of a standard dialytic session. Snap frozen sections of hollow fiber devices were treated with flourescein-isothiocyante conjugated antibodies for IgG, IgA, IgM C3c, fibrinogen, factor VIII, factor XIIIa-s, antithrombin III, fibrinogen degradation products (PDF) and plasminogen.

Protective effect of L-propionylcarnitine on cyclosporine-induced nephrotoxicity.

Nephrotoxicity has represented the major limitation in the use of cyclosporine A (CyA). The structural abnormalities at the level of the proximal tubular cells are necrosis, vacuolisation and lipid droplets, as well as CyA-induced glomerular afferent arteriole constriction and granular juxtaglomerular cell hyperplasia. The mode of action of vasoconstriction is not well known, but there appears to be substantial impairment of endothelial cell function leading to enhanced release of vasoconstrictors such as endothelin and thromboxane.

Acute effects of calcitonin gene related peptide on renal haemodynamics and renin and angiotensin II secretion in patients with renal disease.

The renal haemodynamic effects and renin-angiotensin II response to calcitonin gene-related peptide (CGRP) infusion were assessed in 16 patients with moderate hypertension and renal insufficiency. CGRP lowered the systemic mean blood pressure by 13% and increased the heart rate by 25%; the glomerular filtration rate rose from 56 +/- 11 ml/min to 71 +/- 8 ml/min (p < 0.005), the renal plasma flow decreased from 369 +/- 19 ml/min to 342 +/- 25 ml/min (p < 0.

Mechanisms of acid-base homeostasis in acetate and bicarbonate dialysis, lactate hemofiltration and hemodiafiltration.

The different mechanisms of acidosis buffering were investigated in 15 RDT patients dialyzed in cross-over with four depurative techniques: acetate dialysis (AD), bicarbonate dialysis (BD), lactate hemofiltration (LHF) and hemodiafiltration (HDF) with acetate bath and lactate reinfusion fluid. Blood pH, bicarbonate, blood gases, intraerythrocytic pH - on red cell hemolisates - anion gap, L-lactate, pyruvate, adenosinmonophosphate (ADP) and 2-3 Diphosphoglycerate (2-3 DPG) levels were evaluated. During AD the intradialytic buffering is initially achieved by the CO2 fall and later by the acetate metabolism and an important bicarbonate shift from the intra to the extracellular space.

Effect of increasing doses of lisinopril on proteinuria of normotensive patients with IgA nephropathy and normal renal function.

The antiproteinuric effect of angiotensin converting enzyme (ACE) inhibition in patients with renal disease is well known, but the results of clinical studies appear to vary considerably from a partial decrease to a fall of 100% in urinary protein excretion. This may have been due to the use of different doses of ACE inhibitor, different renal pathology and non-standardized sodium intake. In 16 proteinuric patients with biopsy-proven IgA nephropathy, with normal renal function and blood pressure, maintained at controlled sodium intake < or = 80 mEqII, the efficacy of increasing doses of the ACE inhibitor lisinopril was studied.