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Lightweight biobased insulation polyurethane (BPU) composite foams with high fire-resistance efficiency are interested in building effective energy and low environmental impact today. This study focuses on manufacturing lightweight BPU from liquefied bamboo polyols and biomass resources, including rice husk and wood flour. Then, they are combined with three flame retardant (FR) additives, such as aluminum diethyl phosphinate, aluminum trihydroxide, and diammonium phosphate, to improve their fire resistance performance. The physicochemical properties, microstructure, thermal stability, mechanical properties, and flame-retardant properties of the BPU composites are characterized to optimize their compromise properties. The results showed that composites with optimized FRs achieved UL94 V-0 and those with nonoptimized FRs reached UL94 HB. The limiting oxygen index exhibited that the fire resistance of BPU composites could increase up to 21-37% within FR additives. In addition, the thermal stability of BPU composites was significantly improved in a temperature range of 300-700 °C and the compressive strength of the BPU composites was also enhanced with the presence of FRs. The scanning electron microscopy observation showed an influence of FRs on the morphology and cell size of the BPU composites. The bio-PU-derived samples in this study showed significantly low thermal conductivity values, demonstrating their remarkable thermal insulation effectiveness.
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A set of strained aromatic macrocycles based on [n]cyclo-2,7-(4,5,9,10-tetrahydro)pyrenylenes is presented with size-dependent photophysical properties. The K-region of pyrene was functionalized with ethylene glycol groups to decorate the outer rim and thereby confine the space inside the macrocycle. This confined space is especially pronounced for n=5, which leads to an internal binding of up to 8.0×104 â m-1 between the ether-decorated [5]cyclo-2,7-pyrenylene and shape-complementary crown ether-cation complexes. Both the ether-decorated [n]cyclo-pyrenylenes as well as one of their host-guest complexes have been structurally characterized by single-crystal X-ray analysis. In combination with computational methods the structural and thermodynamic reasons for the exceptionally strong binding have been elucidated. The presented rim confinement strategy makes cycloparaphenylenes an attractive supramolecular host family with a favorable, size-independent read-out signature and binding capabilities extending beyond fullerene guests.
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Cystic fibrosis (CF) is the most frequent genetic disorder in the Caucasian population benefiting from systematic newborn screening tests. It is also the most frequent indication of prenatal and preimplantation genetic diagnosis for a single gene disorder. During the past thirty years, thanks in part to the evolution of diagnostic techniques, our knowledge on CFTR genetics and pathophysiological mechanisms involved in CF have significantly improved. With the implementation of newborn screening in France and in several countries, the diagnosis now often occurs in clinically asymptomatic infants and this has modified the criteria for CF diagnosis. Recently, guidelines for CF diagnosis have been reformulated in Europe and the US, in regard to sweat chloride usual values and disease terminology. This review describes the methods and molecular approaches that are used in routine practice or are being developed to detect CFTR protein dysfunction and to identify disease-causing CFTR variants. Ultimately, an optimal use of all these functional and genetic resources may improve patient care and therapeutic decision-making. © 2020 French Society of Pediatrics. Published by Elsevier Masson SAS. All rights reserved.
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Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose Cística/diagnóstico , Mutação/genética , Biologia Computacional , Fibrose Cística/genética , Variações do Número de Cópias de DNA , Bases de Dados Genéticas , Epitélio/fisiopatologia , Testes Genéticos , Humanos , Polimorfismo de Nucleotídeo Único , Suor/químicaRESUMO
Neonatal screening for cystic fibrosis (CF) can detect infants with elevated immunoreactive trypsinogen (IRT) levels and inconclusive sweat tests and/or CFTR DNA results. These cases of uncertain diagnosis are defined by (1) either the presence of at most one CF-associated cystic fibrosis transmembrane conductance regulator (CFTR) mutation with sweat chloride values between 30 and 59mmol/L or (2) two CFTR mutations with at least one of unknown pathogenic potential and a sweat chloride concentration below 60mmol/L. This encompasses various clinical situations whose progression cannot be predicted. In these cases, a sweat chloride test has to be repeated at 12 months, and if possible at 6 and 24 months of life along with extended CFTR sequencing to detect rare mutations. When the diagnosis is not definite, CFTR functional explorations may provide a better understanding of CFTR dysfunction. The initial evaluation of these infants must be conducted in dedicated CF reference centers and should include bacteriological sputum analysis, chest radiology, and fecal elastase assay. The primary care physicians in charge of these patients should be familiar with the current management of CF and should work in collaboration with CF centers. A follow-up should be performed in a CF reference center at 3, 6, and 12 months of life and every year thereafter. Any symptom indicative of CF requires immediate reevaluation of the diagnosis. These guidelines were established by the "neonatal screening and difficult diagnoses" working group of the French CF society. Their objective is to standardize the management of infants with unclear diagnosis.
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Fibrose Cística/diagnóstico , Fibrose Cística/terapia , Algoritmos , Seguimentos , Humanos , Recém-Nascido , Triagem NeonatalRESUMO
Neonatal screening for cystic fibrosis (CF) may detect infants with elevated immunoreactive trypsinogen (IRT) levels but with inconclusive sweat tests and/or DNA results. This includes cases associating (1) either the presence of at most one CF-causing mutation and sweat chloride values between 30 and 59mmol/L or (2) two CFTR mutations with at least one of unknown pathogenicity and a sweat chloride below 60mmol/L. This encompasses different clinical situations whose progression cannot be predicted. These cases require redoing the sweat test at 12 months and if possible at 6 and 24 months of life. This must be associated with extended genotyping. CFTR functional explorations can also help by investigating CFTR dysfunction. These infants must be initially evaluated in dedicated CF centers including bacteriological sputum analysis, chest radiology and fecal elastase dosage. A home practitioner must be informed of the specificity of follow-up. These infants will be reviewed in the CF center at 3, 6 and 12 months and every year. Any CF-related symptom requires reevaluation of the diagnosis. These guidelines were established by the "neonatal screening and difficult diagnoses" working group of the French CF Society. They aim to standardize management of infants with unclear diagnosis in French CF centers.
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Fibrose Cística/diagnóstico , Fibrose Cística/terapia , Triagem Neonatal/métodos , Cloretos/sangue , Fibrose Cística/genética , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Análise Mutacional de DNA , Diagnóstico Diferencial , Seguimentos , Humanos , Lactente , Recém-Nascido , Comunicação Interdisciplinar , Colaboração Intersetorial , Valor Preditivo dos Testes , Encaminhamento e Consulta , Suor/químicaRESUMO
In patients with cystic fibrosis, cystic fibrosis transmembrane conductance regulator (CFTR) biomarkers, such as sweat chloride concentration and/or nasal potential difference, are used as end-points of efficacy in phase-III clinical trials with the disease modifying drugs ivacaftor (VX-770), VX809 and ataluren. The aim of this project was to review the literature on reliability, validity and responsiveness of nasal potential difference, sweat chloride and intestinal current measurement in patients with cystic fibrosis. Data on clinimetric properties were collected for each biomarker and reviewed by an international team of experts. Data on reliability, validity and responsiveness were tabulated. In addition, narrative answers to four key questions were discussed and agreed by the team of experts. The data collected demonstrated the reliability, validity and responsiveness of nasal potential difference. Fewer data were found on reliability of sweat chloride concentration; however, validity and responsiveness were demonstrated. Validity was demonstrated for intestinal current measurement, but further information is required on reliability and responsiveness. For all three end-points, normal values were collected and further research requirements were proposed. This body of work adds useful information to support the promotion of CFTR biomarkers to surrogate end-points and to guide further research in the area.
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Regulador de Condutância Transmembrana em Fibrose Cística/análise , Fibrose Cística/diagnóstico , Biomarcadores/análise , Fibrose Cística/tratamento farmacológico , Humanos , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Nasal polyposis, a chronic inflammatory disease affecting the upper airways, is a valuable and accessible model to investigate the mechanisms underlying chronic inflammation. The main objective of this study was to investigate a potential involvement of the unfolded protein response (UPR) in the context of oxidative stress and inflammation in nasal epithelial cells from nasal polyps (NP). METHODS: Epithelial cells from NP (n = 20) and normal mucosa (Controls, n = 15) in primary culture were analyzed by global proteomic approach and cell biology techniques for the glucose-regulated protein 78 (GRP78), the spliced X-box-binding protein 1 (sXBP-1), the glucose-regulated protein 94 (GRP94), and the calreticulin (immunoblot, mass spectrometry, immunocytochemistry). RESULTS: Proteomics analysis of human nasal epithelial cells in culture revealed the activation of the unfolded protein response in NP. Systematic cell biology and biochemical analysis of two markers (GRP78, sXBP-1) in the presence and absence of oxidative stress in NP showed a susceptibility of the unfolded protein response to oxidative stress compared to controls at least partially linked to an abnormal redox state of the protein disulfide-isomerase 4. This unfolded protein response was correlated with mitochondrial depolarization and secretion of interleukin 8 (IL-8) and leukotriene B4 (LTB4) and was prevented by mitochondrial antioxidant. CONCLUSIONS: We show the existence of UPR in nasal epithelial cells that is linked to oxidative stress leading to IL-8 and LTB4 secretions. These mechanisms may participate in chronic inflammation in nasal polyposis.
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Células Epiteliais/patologia , Inflamação/imunologia , Mucosa Nasal/imunologia , Pólipos Nasais/fisiopatologia , Estresse Oxidativo , Resposta a Proteínas não Dobradas , Antioxidantes/farmacologia , Células Cultivadas , Chaperona BiP do Retículo Endoplasmático , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Regulação da Expressão Gênica , Humanos , Interleucina-8/metabolismo , Leucotrieno B4/metabolismo , Mucosa Nasal/citologia , Pólipos Nasais/imunologia , Proteoma , ProteômicaRESUMO
Glutamate transport (GluT) in brain is mediated chiefly by two transporters GLT and GLAST, both driven by ionic gradients generated by (Na(+), K(+))-dependent ATPase (Na(+)/K(+)-ATPase). GLAST is located in astrocytes and its function is regulated by translocations from cytoplasm to plasma membrane in the presence of GluT substrates. The phenomenon is blocked by a naturally occurring toxin rottlerin. We have recently suggested that rottlerin acts by inhibiting Na(+)/K(+)-ATPase. We now report that Na(+)/K(+)-ATPase inhibitors digoxin and ouabain also blocked the redistribution of GLAST in cultured astrocytes, however, neither of the compounds caused detectable inhibition of ATPase activity in cell-free astrocyte homogenates (rottlerin inhibited app. 80% of Pi production from ATP in the astrocyte homogenates, IC50 = 25 µM). Therefore, while we may not have established a direct link between GLAST regulation and Na(+)/K(+)-ATPase activity we have shown that both ouabain and digoxin can interfere with GluT transport and therefore should be considered potentially neurotoxic.
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Astrócitos/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Digoxina/farmacologia , Transportador 1 de Aminoácido Excitatório/metabolismo , Ouabaína/farmacologia , Animais , Animais Recém-Nascidos , Astrócitos/enzimologia , Astrócitos/metabolismo , Encéfalo/citologia , Encéfalo/enzimologia , Encéfalo/metabolismo , Imuno-Histoquímica , Ratos , Ratos Sprague-Dawley , ATPase Trocadora de Sódio-Potássio/metabolismoRESUMO
These guidelines aim to standardize the standard operating procedures for the sweat test in newborn cystic fibrosis (CF) screening. They have been implemented by the national Neonatal Screening working group of the French Federation for Cystic Fibrosis. It is recommended that the sweat test be performed when the infant weighs more than 3 kg and is at least 3 weeks of age. Sweat gland secretion is stimulated by transdermal administration of pilocarpine by iontophoresis. Sweat is preferentially collected in a Macroduct coil. Diagnosis of CF is based on the sweat chloride level. A sweat chloride level below 30 mmol/l very probably rules out CF; 60 mmol/l or higher supports the diagnosis of CF. Values between 30 and 60 mmol/l are considered abnormal.
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Cloretos/análise , Fibrose Cística/diagnóstico , Triagem Neonatal , Suor/química , Administração Cutânea , Humanos , Lactente , Recém-Nascido , Iontoforese , Agonistas Muscarínicos/administração & dosagem , Pilocarpina/administração & dosagem , Valor Preditivo dos Testes , Padrões de Referência , Sudorese/efeitos dos fármacosRESUMO
The naturally occurring toxin rottlerin has been used by other laboratories as a specific inhibitor of protein kinase C-delta (PKC-delta) to obtain evidence that the activity-dependent distribution of glutamate transporter GLAST is regulated by PKC-delta mediated phosphorylation. Using immunofluorescence labelling for GLAST and deconvolution microscopy we have observed that D-aspartate-induced redistribution of GLAST towards the plasma membranes of cultured astrocytes was abolished by rottlerin. In brain tissue in vitro, rottlerin reduced apparent activity of (Na+, K+)-dependent ATPase (Na+, K+-ATPase) and increased oxygen consumption in accordance with its known activity as an uncoupler of oxidative phosphorylation ("metabolic poison"). Rottlerin also inhibited Na+, K+-ATPase in cultured astrocytes. As the glutamate transport critically depends on energy metabolism and on the activity of Na+, K+-ATPase in particular, we suggest that the metabolic toxicity of rottlerin and/or the decreased activity of the Na+, K+-ATPase could explain both the glutamate transport inhibition and altered GLAST distribution caused by rottlerin even without any involvement of PKC-delta-catalysed phosphorylation in the process.
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Acetofenonas/farmacologia , Astrócitos/metabolismo , Benzopiranos/farmacologia , Encéfalo/metabolismo , Ácido D-Aspártico/metabolismo , Transportador 1 de Aminoácido Excitatório/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Sistema X-AG de Transporte de Aminoácidos/análise , Sistema X-AG de Transporte de Aminoácidos/antagonistas & inibidores , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Animais , Animais Recém-Nascidos , Astrócitos/química , Astrócitos/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Química Encefálica/efeitos dos fármacos , Química Encefálica/fisiologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/antagonistas & inibidores , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Células Cultivadas , Ácido D-Aspártico/análise , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Transportador 1 de Aminoácido Excitatório/análise , Transportador 1 de Aminoácido Excitatório/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley , ATPase Trocadora de Sódio-Potássio/antagonistas & inibidoresRESUMO
Neurotransmitter L-glutamate released at central synapses is taken up and "recycled" by astrocytes using glutamate transporter molecules such as GLAST and GLT. Glutamate transport is essential for prevention of glutamate neurotoxicity, it is a key regulator of neurotransmitter metabolism and may contribute to mechanisms through which neurons and glia communicate with each other. Using immunocytochemistry and image analysis we have found that extracellular D-aspartate (a typical substrate for glutamate transport) can cause redistribution of GLAST from cytoplasm to the cell membrane. The process appears to involve phosphorylation/dephosphorylation and requires intact cytoskeleton. Glutamate transport ligands L-trans-pyrrolidine-2,4-dicarboxylate and DL-threo-3-benzyloxyaspartate but not anti,endo-3,4-methanopyrrolidine dicarboxylate have produced similar redistribution of GLAST. Several representative ligands for glutamate receptors whether of ionotropic or metabotropic type, were found to have no effect. In addition, extracellular ATP induced formation of GLAST clusters in the cell membranes by a process apparently mediated by P2 receptors. The present data suggest that GLAST can rapidly and specifically respond to changes in the cellular environment thus potentially helping to fine-tune the functions of astrocytes.
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Trifosfato de Adenosina/metabolismo , Sistema X-AG de Transporte de Aminoácidos/metabolismo , Astrócitos/metabolismo , Membrana Celular/metabolismo , Transportador 1 de Aminoácido Excitatório/metabolismo , Ácido Glutâmico/metabolismo , Trifosfato de Adenosina/análise , Sistema X-AG de Transporte de Aminoácidos/análise , Animais , Animais Recém-Nascidos , Astrócitos/química , Astrócitos/fisiologia , Membrana Celular/química , Células Cultivadas , Transportador 1 de Aminoácido Excitatório/análise , Líquido Extracelular/química , Líquido Extracelular/metabolismo , Ácido Glutâmico/análogos & derivados , Ácido Glutâmico/análise , Transporte Proteico/fisiologia , Ratos , Ratos Sprague-Dawley , Especificidade por Substrato/fisiologiaRESUMO
The sweat test, a quantitative measurement of chloride in sweat, remains a key laboratory test to support the diagnosis of cystic fibrosis. However, because of its delicate execution, sweat test result should be interpreted with biological, clinical and genetic arguments. The following guidelines which we propose, were established in order to harmonize the practices of the sweat test. They are elaborated in a consensual way by biologists from cystic fibrosis reference centers and/or from the working group "Sweat Testing" of the National College of Biochemistry Hospital praticiens, according to the current state of knowledge on the subject, the experiment of the biologists and the recommendations established in the United States and in the United Kingdom.
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Cloretos/análise , Fibrose Cística/diagnóstico , Triagem Neonatal/normas , Guias de Prática Clínica como Assunto , Suor/química , França , Humanos , Recém-Nascido , Iontoforese , Controle de Qualidade , Manejo de Espécimes , Reino Unido , Estados UnidosRESUMO
Hypothetical model based on deficient glutamatergic neurotransmission caused by hyperactive glutamate transport in astrocytes surrounding excitatory synapses in the prefrontal cortex is examined in relation to the aetiology of schizophrenia. The model is consistent with actions of neuroleptics, such as clozapine, in animal experiments and it is strongly supported by recent findings of increased expression of glutamate transporter GLT in prefrontal cortex of patients with schizophrenia. It is proposed that mechanisms regulating glutamate transport be investigated as potential targets for novel classes of neuroactive compounds with neuroleptic characteristics. Development of new efficient techniques designed specifically for the purpose of studying rapid activity-dependent translocation of glutamate transporters and associated molecules such as Na+, K+-ATPase is essential and should be encouraged.
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Regulação Enzimológica da Expressão Gênica , Glutamatos/metabolismo , Glutamina/metabolismo , Esquizofrenia/metabolismo , Esquizofrenia/patologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Transporte Biológico , Sistema Nervoso Central/metabolismo , Proteínas de Transporte de Glutamato da Membrana Plasmática/metabolismo , Ácido Glutâmico/metabolismo , Humanos , Modelos Biológicos , Neurotransmissores/metabolismo , Córtex Pré-Frontal , Transtornos Psicóticos , Sinapses/metabolismoRESUMO
Incidence of cardiovascular events is higher in hemodialysis (HD) patients than in general population. Oxidative stress represents a major specific risk factor of accelerated atheroma particularly in association with inflammation and malnutrition. The aim of our study is to evaluate a simple test of lipid peroxidation measurement using the "Free Oxygen Radical Monitor" (FORM) (Callegari, Italy). The results obtained in HD patients were compared to standard oxidative stress markers, such as thiobarbituric acid reacting substances, carbonyls and vitamin E in plasma, and glutathione, oxidized to reduced form ratio, in erythrocytes. In conclusion, the FORM system presents no sufficient sensibility and specificity to determine oxidative stress in HD patients.
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Peroxidação de Lipídeos , Estresse Oxidativo , Oxigênio/sangue , Diálise Renal , Feminino , Radicais Livres/sangue , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
Cardiovascular (CV) disease in uremic patients is a major concern to the nephrologist because it represents the main cause of morbidity and mortality in chronic renal failure patients, both predialysis and while on dialysis therapy. CV mortality is 3 to 20 times higher in dialysis patients than in the general population at similar age. Of note, a high prevalence of CV comorbidity is already present at start of maintenance dialysis, and is predictive of subsequent mortality on dialysis. CV disease progresses over years prior to the onset of ESRD, because risk factors develop from the early stage of chronic renal insufficiency. However, CV disease may be prevented or attenuated in patients who benefit from early, regular care of CV risk factors. Mechanisms of uremic cardiopathy, the major cause of mortality in uremic patients, are multifactorial and their effects are cumulative. Risk factors for left ventricular hypertrophy are hypertension, anemia, fluid overload and arteriosclosis, all of which are amendable by therapy. Risk factors for accelerated atherosclerosis, responsible for ischemic cardiopathy and myocardial infarction, are both common factors (e.g., hypertension, tobacco smoking and diabetes) and factors more specific for the uremic state (e.g., dyslipidemia, hyperhomocysteinemia and oxidative stress), all of which also are amendable by proper therapy. As a result, mixed hypertensive and ischemic cardiomyopathy develops, ultimately leading to cardiac failure, together with accidents resulting from valvular and arterial calcifications (favored by calcium-phosphate disorders), and from occlusion of coronary, cerebral and peripheral arteries. Cardioprotective therapy thus has become a cornerstone in the management of chronic renal failure patients, in conjunction with renoprotective therapy. Cardioprotective strategy involves optimal treatment of hypertension, anemia, fluid overload, dyslipidemia, hyperhomocysteinemia and calcium-phosphate disorders, and smoking cessation. To achieve a maximal efficacy, such treatment has to be initiated as early as possible in the course of renal failure. Because of its complexity, the integrated combined nephrotective and cardioprotective therapy requires early and sustained guidance by a nephrologist throughout the whole predialysis period.
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Doenças Cardiovasculares/prevenção & controle , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Anemia/terapia , Arteriosclerose/prevenção & controle , Doenças Cardiovasculares/epidemiologia , Humanos , Hipertensão/terapia , Falência Renal Crônica/mortalidade , Diálise Renal , Fatores de RiscoRESUMO
BACKGROUND: Late nephrological referral of chronic renal failure patients has been shown to be associated with high morbidity and short-term mortality on dialysis. However, the impact of predialysis nephrological care duration (PNCD) on the long-term survival of dialysis patients had not been evaluated. METHODS: We studied data from all 1057 consecutive patients who started dialysis treatment at the Necker Hospital from 1989 to 1998 (mean age at start of dialysis 53.8+/-17.2 years (range 18-91 years), excluding from analysis patients who presented with acute renal failure (n=60) or advanced malignancy (n=35). We evaluated the effects of PNCD and clinical risk factors on all-cause mortality after long-term follow-up on dialysis. RESULTS: Among the 1057 patients analysed (13.2% diabetics), PNCD was <6 months in 258 patients, 6-35 months in 267 patients, 36-71 months in 227 patients and >or=72 months in 307 patients. Cardiovascular (CV) morbidity, namely a history of myocardial or cerebral infarction, peripheral arteriopathy, and/or cardiac failure, before starting dialysis was 39.6% and 37.4%, respectively, in patients followed for <6 months or 6-35 months, compared with 24.4% in those followed for 36-71 months and 19.9% in those followed for >or=72 months (P<0.001). Five-year survival was significantly lower in patients with a PNCD of <6 months (59+/-4.1%) than for 36-71 months or >or=72 months (77.1+/-3.7 and 73.3+/-3.6%, respectively, P<0.001), but similar to those followed for 6-35 months (65.3+/-3.9%, NS). By Cox proportional hazard analysis, PNCD <6 months, age, diabetes and prior CV disease were independent predictive factors of all-cause death on dialysis. CONCLUSIONS: This study provides suggestive evidence that longer duration of regular nephrological care in the predialysis period, at least for several years prior to the start of dialysis, is associated with a better long-term survival on dialysis. Such data strongly support the argument for early referral and regular nephrological care of chronic renal failure patients.
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Falência Renal Crônica/terapia , Nefrologia/métodos , Diálise Renal , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/mortalidade , Demografia , Feminino , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Encaminhamento e Consulta , Análise de Sobrevida , Fatores de TempoRESUMO
BACKGROUND: Oxidative stress has long been demonstrated in haemodialysis patients. However, the factors influencing their oxidative status have not been characterized extensively in these patients. Therefore, the present study was designed to investigate the influence of a large number of factors known to be associated with oxidative stress. METHODS: In the present cross-sectional study, we determined the plasma levels of lipid and protein oxidation markers in 31 non-smoking haemodialysis patients and 18 non-smoking healthy subjects, together with various components of the antioxidant system at the plasma and erythrocyte level. RESULTS: No influence of age, diabetes or iron overload on oxidative markers and plasma and erythrocyte antioxidant systems was detected in these haemodialysis patients. The lack of an association between iron overload and oxidative status may be related to the lower level of plasma ascorbate in haemodialysis patients, since ascorbate favours the generation of free iron from ferritin-bound iron. Interestingly, plasma C reactive protein (CRP) levels measured by highly sensitive CRP assay were correlated positively with plasma levels of thiobarbituric acid reactive substances (r=0.38, P<0.04) and negatively with plasma alpha-tocopherol levels (r=-0.46, P<0.01). Moreover, significant inverse correlations were observed between duration of dialysis treatment and plasma levels of alpha-tocopherol (r=-0.49, P<0.02) and ubiquinol (r=-0.40, P<0.05). CONCLUSIONS: Our results suggest that inflammatory status and duration of dialysis treatment are the most important factors relating to oxidative stress in haemodialysis patients.