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1.
Lupus ; 27(9): 1552-1558, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29635999

RESUMO

Antiphospholipid syndrome is characterized by multiple arterial and/or venous thrombotic events, recurrent fetal losses in the presence of antiphospholipid antibodies (aPL). Catastrophic antiphospholipid syndrome is a life-threatening, rare subset of antiphospholipid syndrome when the thrombotic events affect at least three organs, and clinical manifestations develop simultaneously or within a week. Diagnostically, small vessel occlusions can be detected by histopathology in the presence of aPL. Our case report describes an 18-year-old man who has been treated for antiphospholipid syndrome associated with systemic lupus erythematosus (SLE) since 2011. The clinical findings were dominated by recurrent deep vein thrombosis, and severe proteinuria caused by lupus nephritis, accompanied by mild serological and laboratory findings. The patient was hospitalized in March 2014 because of severe thrombocytopenia and infective diarrhoea. At this time the renal functions deteriorated rapidly. Simultaneously, left upper extremity paresis was observed; computed tomography showed ischaemic lesions in the territory of the middle cerebral artery. Abdominal discomfort and pain occurred. On computed tomography scan ischaemic lesions were seen in the spleen, the right kidney and the coeliac trunk. Laboratory and serological findings verified the presence of aPL and anti-DNA antibodies, anaemia and thrombocytopenia. Based on the above-mentioned clinical and laboratory findings, the diagnosis of catastrophic antiphospholipid syndrome was established. Anticoagulation, corticosteroids and plasma exchange treatment, as well as haemodiafiltration were initiated. Although the thrombotic cascade decelerated following these interventions, we could not see an improvement in the renal function. Rituximab treatment was started, leading to a significant improvement in renal function. After 5 weeks of treatment the patient was discharged from hospital.


Assuntos
Síndrome Antifosfolipídica/complicações , Fatores Imunológicos/uso terapêutico , Nefrite Lúpica/complicações , Rituximab/uso terapêutico , Trombose/imunologia , Síndrome Antifosfolipídica/tratamento farmacológico , Síndrome Antifosfolipídica/patologia , Humanos , Rim/ultraestrutura , Nefrite Lúpica/tratamento farmacológico , Nefrite Lúpica/patologia , Masculino , Trombose/tratamento farmacológico , Trombose/patologia , Adulto Jovem
2.
Transplant Proc ; 47(7): 2192-5, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26361677

RESUMO

INTRODUCTION: Cardiovascular disease is a major cause of morbidity and mortality in end-stage renal disease patients on dialysis and the most common cause of death in the immediate post-transplantation period. The aim of our study was to describe a novel approach of cardiovascular screening and management of dialysis patients evaluated for the transplant waiting list. METHODS: Twenty-eight patients with end-stage renal disease put on the waiting list between July 2013 and July 2014 were subjected to a prespecified cardiovascular screening protocol utilizing noninvasive and/or invasive tests. Patients were subsequently divided into 3 strata in terms of their estimated cardiovascular risk. Each of these groups were then prescribed interventions aiming to improve their cardiovascular condition. RESULTS: According to our prespecified protocol of cardiovascular screening studies, 15 (54%) patients were identified as low, 5 (18%) as intermediate, and 8 (28%) as high risk. Four (14%) patients were current smokers. In the low-risk group, we initiated a patient education program involving counseling on regular exercise such as swimming or cycling to improve their functional capacity. In the high-risk group revascularization was done in 5 cases (63%), including 3 percutaneous transluminal coronary angioplasties (PTCA) with stents for single-vessel disease, and coronary artery bypass graft surgeries (CABG) for triple-vessel disease in 2 cases. In the medium-risk group medical management was opted for, including introduction of beta-blockers, inhibitors, statins, and ezetimibe, as well as efforts to optimize anemia management, indices of bone-mineral disease, and fluid status. CONCLUSION: In our regional transplant program, we introduced a comprehensive multidisciplinary approach to treat potential transplant candidates according to cardiovascular risk stratification based on a prespecified screening protocol. Further studies are needed to correlate this novel strategy with post-transplantation outcomes.


Assuntos
Doenças Cardiovasculares/diagnóstico , Falência Renal Crônica/complicações , Transplante de Rim , Cuidados Pré-Operatórios/métodos , Adulto , Idoso , Angioplastia Coronária com Balão , Doenças Cardiovasculares/terapia , Ponte de Artéria Coronária , Feminino , Humanos , Hungria , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Diálise Renal , Fatores de Risco , Listas de Espera
3.
Pharmazie ; 67(5): 380-3, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22764567

RESUMO

Cardiovascular diseases are frequent complications of end-stage kidney disease. The aim of the present study was to prove the arrhythmogenic effect of dialysis using signal averaged ECG. The ECG changes and laboratory parameters (sodium, potassium, urea and creatinine levels) were detected during hemodialysis treatment in 26 patients suffering from end-stage kidney disease. The tests and the ECG were performed four times, before (0. minute), during (at 15 and 90 min), and eventually after dialysis (at 240 min). The duration of the QRS complex, high-frequency low-amplitude signals (HFLA), and root-mean-square voltage of the terminal 40 ms of the filtered QRS (RMS) were determined. We considered test results to be positive when two of the three tested parameters were outside the normal range: QRS > 120 ms, RMS < 20 uV, HFLA > 39 ms. Signal averaged ECG was positive in two cases (8%) before and after the dialysis. The duration of the QRS-complex increased significantly during the dialysis (predialysis: 109 +/- 7.6 ms, postdialysis: 116 +/- 8.0 ms, p < 0.0001). Serum urea nitrogen (predialysis: 26.2 +/- 5.4, postdialysis: 11.4 +/- 3.3 mmol/l, p <0.0001) and serum creatinine levels (predialysis: 931 +/- 212, postdialysis: 434 +/- 120 micromol/I, p < 0.0001) decreased significantly during the treatment. Significant and continuous decrease in the potassium levels were detected (predialysis: 5.30 +/- 0.72, postdialysis: 3.91 +/- 0.42 mmol/I, p < 0.0001) during the dialysis. Serum sodium levels (predialysis: 139 +/- 2.7, postdialysis: 141.4 +/- 2.2 mmol/I) had not changed during the dialysis. A significant negative correlation was found between decreasing potassium levels and increasing QRS duration (r = - 0.48, p = 0.01). Our results support our primer assumption that the metabolic changes during dialysis treatment can lead to considerable risk of cardiac arrhythmias.


Assuntos
Eletrocardiografia/métodos , Metabolismo/fisiologia , Diálise Renal/efeitos adversos , Idoso , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/fisiopatologia , Creatinina/metabolismo , Interpretação Estatística de Dados , Eletrólitos/metabolismo , Feminino , Frequência Cardíaca/fisiologia , Humanos , Falência Renal Crônica/metabolismo , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Ureia/metabolismo
5.
Acta Physiol Hung ; 94(1-2): 95-106, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17444278

RESUMO

Inflammation induced anemia and resistance to erythropoietin are common features in patients with chronic kidney disease (CKD). Elevated levels of cytokines and enhanced oxidative stress, conditions associated with inflammatory states, are implicated in the development of anemia. Accumulating evidence suggests that activation of cytokine cascade and the associated acute-phase response, as it often occurs in patients with CKD, divert iron from erythropoiesis to storage sites within the reticuloendothelial system leading to functional iron deficiency and subsequently to anemia or resistance to erythropoietin. Other processes have also been shown to be involved in the pathogenesis of anemia provoked by the activated immune system including an inhibition of erythroid progenitor proliferation and differentiation, a suppression of erythropoietin production and a blunted response to erythropoietin. The present review concerns the underlying alterations in iron metabolism induced by chronic inflammation that result in anemia.


Assuntos
Homeostase/fisiologia , Inflamação/fisiopatologia , Ferro/metabolismo , Falência Renal Crônica/complicações , Animais , Peptídeos Catiônicos Antimicrobianos/fisiologia , Proteínas de Transporte de Cátions/fisiologia , Envelhecimento Eritrocítico/fisiologia , Eritrócitos/metabolismo , Eritropoese/fisiologia , Ferritinas/biossíntese , Hepcidinas , Humanos , Proteína 1 Reguladora do Ferro/fisiologia , Proteína 2 Reguladora do Ferro/fisiologia , Receptores da Transferrina/fisiologia , Transferrina/metabolismo
6.
Kidney Int ; 69(1): 144-51, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16374435

RESUMO

Oxidative modification of low-density lipoprotein (LDL) and its deleterious effect on endothelium is implicated in the pathogenesis of atherosclerosis. Endothelium responds to such an insult by upregulating the synthesis of heme oxygenase-1 (HO-1) and ferritin. Endothelial cell damage and dysfunction have been observed in patients with chronic kidney disease (CKD) on maintenance hemodialysis (HD). We studied the effect of low-molecular-weight components of uremic plasma on LDL oxidation and LDL-oxidation-provoked endothelial cell reactions, such as the induction of cytotoxicity and the upregulation of cell-protective HO-1 and ferritin. Plasma ultrafiltrate (molecular weight<5000 Da) from CKD patients on HD or when treated conservatively exhibited a pronounced inhibition on heme-mediated oxidative modification of LDL. Endothelial cell cytotoxicity provoked by LDL oxidation was also attenuated by plasma ultrafiltrate from CKD patients. During HD treatment, a dramatic drop occurred in the retardation of oxidative reactions, and a loss of endothelial cytoprotection exerted by plasma ultrafiltrate was noted. The upregulation of HO-1 and ferritin in response to oxidative stress of LDL was blunted by uremic plasma ultrafiltrate that was released by the end of HD. The decreased antioxidant capacity of ultrafiltrate after HD occurred as a consequence of the intradialytic removal of L-ascorbic acid, uric acid, bilirubin, 3-indoxyl sulfate, indoxyl-beta-D-glucuronide, p-cresol, and phenol. Intradialytic removal of L-ascorbic acid, uric acid, bilirubin, 3-indoxyl sulfate, indoxyl-beta-D-glucuronide, p-cresol, and phenol increases the risk of LDL oxidation and subsequent endothelial cell damage, which underlines the importance of activation of cytoprotective HO-1 and ferritin in endothelium.


Assuntos
Antioxidantes/farmacologia , Aterosclerose/etiologia , Células Endoteliais/efeitos dos fármacos , Lipoproteínas LDL/metabolismo , Diálise Renal/efeitos adversos , Adulto , Idoso , Citoproteção , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Feminino , Ferritinas/biossíntese , Heme Oxigenase-1/genética , Heparina/farmacologia , Humanos , Peroxidação de Lipídeos , Lipoproteínas LDL/toxicidade , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/análise , Ultrafiltração
7.
Phytomedicine ; 13(1-2): 85-93, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16360937

RESUMO

Structural analogues (flavanone: 2-4 and flavone: 5 and 6, respectively) of silybin (1a) were synthesized and tested for inhibitory activity on O(2)(-) release and PKC translocation in PMA-stimulated neutrophils as well as xanthine oxidase activity in order to identify the molecular structures responsible for the antioxidant property of silybin. Concerning the prevention of hem-mediated oxidative modification of LDL by silybin, the hydroxyl radical scavenging activity of its structural analogues was also determined. We demonstrated that the basic skeleton of 1a (4) is responsible for its inhibitory activity on O(2)(-) release in PMA-stimulated neutrophils via inhibition of PKC translocation, since introduction of a double bound and hydroxyl groups at C-5 and C-7 position (5 and 6) did not result in further increase in inhibition of O(2)(-) release. It has been shown that the presence of the phenolic hydroxyl group at C-5 and C-7 of 1a is essential for the inhibition of xanthine oxidase activity. Moreover, introduction of a double bond into the C-ring of 2 and 3, resulting in flavone derivatives (5 and 6), markedly enhanced the antioxidant effect in all the tested systems. Finally, silybin (1a) and its flavon derivatives (5 and 6) directly scavenged hydroxyl radicals as well. On the basis of these results it might be concluded that different moiety of silybin is responsible for inhibition of overproduction of O(2)(-) in stimulated neutrophils, xanthine oxidase activity, and for prevention of hem-mediated oxidative modification of LDL.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , LDL-Colesterol/metabolismo , Citosol , Sequestradores de Radicais Livres , Humanos , Radical Hidroxila/metabolismo , Estrutura Molecular , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Oxirredução , Proteína Quinase C/metabolismo , Silibina , Silimarina/química , Silimarina/farmacologia , Superóxidos/metabolismo , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Xantina Oxidase/antagonistas & inibidores , Xantina Oxidase/metabolismo
8.
Folia Microbiol (Praha) ; 51(6): 547-54, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17455791

RESUMO

N-Acetyl-D-glucosamine, chito-oligomers and carbon starvation regulated chiA, chiB, and nagA gene expressions in Aspergillus nidulans cultures. The gene expression patterns of the main extracellular endochitinase ChiB and the N-acetyl-beta-D-glucosaminidase NagA were similar, and the ChiB-NagA enzyme system may play a morphological and/or nutritional role during autolysis. Alterations in the levels of reactive oxygen species or in the glutathione-glutathione disulfide redox balance, characteristic physiological changes developing in ageing and autolyzing fungal cultures, did not affect the regulation of either the growth-related chiA or the autolysis-coupled chiB genes although both of them were down-regulated under diamide stress. The transcription of the chiC gene with unknown physiological function was repressed by increased intracellular superoxide concentration.


Assuntos
Aspergillus nidulans/enzimologia , Quitinases/biossíntese , Proteínas Fúngicas/biossíntese , Regulação Fúngica da Expressão Gênica , Acetilglucosamina/farmacologia , Aspergillus nidulans/genética , Aspergillus nidulans/fisiologia , Carbono/metabolismo , Quitinases/genética , Biologia Computacional , DNA Fúngico/genética , Indução Enzimática , Proteínas Fúngicas/genética , Oligossacarídeos/farmacologia , Oxirredução , Filogenia , Espécies Reativas de Oxigênio/metabolismo
9.
Cell Mol Biol (Noisy-le-grand) ; 51(4): 377-85, 2005 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-16309588

RESUMO

Heme-catalyzed oxidation of low-density lipoprotein (LDL) is one of the relevant mechanisms involved in LDL modification. We previously revealed a substantial oxidation of plasma hemoglobin to methemoglobin and a subsequent heme-catalyzed LDL oxidation generating moieties toxic to endothelium in heme oxygenase-1 (HO-1)-deficiency in human. Drawing upon our previous observation we posited a pathway for oxidation of plasma hemoglobin in the HO-1-deficient child involving LDL-associated lipid hydroperoxide. In support, LDL-associated lipid hydroperoxide oxidized ferrohemoglobin to methemoglobin--known to readily release its heme moieties--in a dose-dependent manner. Repeated heme exposure of the child s LDL further increased its lipid hydroperoxide content within min leading to additional cytotoxic effect on endothelium. Both cytotoxicity and HO-1 inducing ability of the oxidized LDL were strongly dependent on its lipid hydroperoxide content. We wondered if cells of the HO-1-deficient patient were prone to oxidative damage arising from heme-mediated oxidation of LDL. Indeed, we found elevated cytotoxicity induced by heme-catalyzed oxidation of LDL in lymphoblastoid cells derived from the HO-1-deficient patient. We conclude that oxidation of hemoglobin to methemoglobin by LDL-associated lipid hydroperoxide and increased sensitivity of cells of the HO-1-deficient child to stress of oxidized LDL might contribute to the vascular disorders reported earlier.


Assuntos
LDL-Colesterol/metabolismo , Heme Oxigenase-1/deficiência , Heme Oxigenase-1/metabolismo , Hemoglobinas/metabolismo , Peróxidos Lipídicos/metabolismo , Proliferação de Células , Células Cultivadas , Heme Oxigenase-1/genética , Humanos , Oxirredução , RNA Mensageiro/genética
10.
Clin Nephrol ; 64(5): 343-51, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16312261

RESUMO

AIM: Approximately 20-50% of IgA nephropathy patients develop end-stage renal disease. We have previously found enhanced oxidative stress and decreased antioxidant capacity in red blood cells of IgA nephropathy patients. In this study we assess oxidative stress, non-enzymatic glycation, oxidative resistance of low-density lipoprotein and its alpha-tocopherol content in these patients. PATIENTS AND METHODS: Non-enzymatic glycation and oxidative stress were assessed in 88 IgA nephropathy patients by measuring advanced glycation end products, Nepsilon-carboxymethyl-lysine, thiobarbituric acid reactive substances, oxidative resistance of low-density lipoprotein and its alpha-tocopherol content. RESULTS: Advanced glycation end products (2659 +/- 958 a.u.) and Nepsilon-carboxymethyl-lysine (563 +/- 215 ng/ml) were significantly higher in IgA nephropathy patients with decreased renal function compared to those with normal renal function (p < 0.002) or controls (p < 0.001). Thiobarbituric acid-reactive substances in plasma and associated with low-density lipoprotein were significantly elevated and oxidative resistance of low-density lipoprotein was significantly reduced in all groups of IgA nephropathy patients. There was no significant difference in circulating fluorescent advanced glycation end products, Nepsilon-carboxymethyl-lysine, thiobarbituric acid-reactive substances levels, oxidative resistance of low-density lipoprotein and its alpha-tocopherol content between patients with normal vs. impaired glucose metabolism. Low alpha-tocopherol content of low-density lipoprotein was accompanied with decreased oxidative resistance, depletion in polyunsaturated fatty acids, elevated saturated fatty acids and thiobarbituric acid-reactive substances within low-density lipoprotein suggesting enhanced lipid peroxidation. CONCLUSIONS: Decreased oxidative resistance of low-density lipoprotein and enhanced oxidative stress are common features in IgA nephropathy, while increased non-enzymatic glycation occurs as renal function declines.


Assuntos
Glomerulonefrite por IGA/metabolismo , Estresse Oxidativo , Adulto , Feminino , Produtos Finais de Glicação Avançada/metabolismo , Glicosilação , Humanos , Lipoproteínas LDL/metabolismo , Masculino , Pessoa de Meia-Idade , alfa-Tocoferol/metabolismo
11.
Phytomedicine ; 11(2-3): 206-12, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15070174

RESUMO

Mechanism of the action of silybin (1) and its derivatives (2-4), possessing different lipid solubility in PMA-stimulated neutrophils was evaluated. Silybin (1) inhibited the calcium, phosphatidylserine- and diacylglycerol-dependent protein kinase C translocation and the NADPH oxidase activity in PMA-stimulated neutrophils and resulted in decreased apoptosis. Furthermore, silybin (1) inhibited xanthine oxidase activity and hem-mediated oxidative degradation of low-density lipoprotein, as well. Its derivatives (2-4), possessing different lipid-solubility, affected all the studied parameters. The lipid solubility of silybin (1) was enhanced by methylation (5'7'4''trimethylsilybin: 2), whereas a decrease in lipid-solubility by acetylation of compound 2 (5',7,'4"-trimethylsilybin-acetate: 3) or all the hydroxyl groups of silybin (peracetyl-silybin: 4) attenuated the antioxidant capacity by decreasing the inhibition in PKC translocation and NADPH oxidase activation. All the derivatives of silybin (2-4) showed no inhibition in cell free systems; e.g. did not alter the xanthine oxidase activity and the hem-mediated oxidative degradation of LDL. In conclusion, the antioxidant activity of (1) might be due to its ability to inhibit PKC translocation and NADPH oxidase activation in PMA-stimulated neutrophils. The increase of lipid solubility of silybin (1) supports its penetration through cell membrane and enhances its inhibitory effects. This structural modification of (1) might have pharmacological consequences.


Assuntos
Antioxidantes/farmacologia , Neutrófilos/efeitos dos fármacos , Fitoterapia , Silybum marianum , Silimarina/farmacologia , Antioxidantes/administração & dosagem , Antioxidantes/uso terapêutico , Apoptose/efeitos dos fármacos , Transporte Biológico/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/metabolismo , NADPH Oxidases/efeitos dos fármacos , Neutrófilos/enzimologia , Extratos Vegetais/administração & dosagem , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Proteína Quinase C/efeitos dos fármacos , Silibina , Silimarina/administração & dosagem , Silimarina/uso terapêutico
12.
Med Hypotheses ; 56(6): 694-6, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11399120

RESUMO

Ischaemic stroke ranks among the most important causes of death and disability in developed countries. Abnormal lipid metabolism is among the several factors that have a role in the pathogenesis of atherosclerosis. We hypothesize that the decreased resistance of low-density lipoproteins against oxidative stress is an independent risk factor for cerebral atherosclerosis and suggest testing this hypothesis by ultrasonographic evaluation of the carotid artery and correlating this finding to plasma values of compounds that play a role in lipid metabolism. By measuring the oxidative resistance of low-density of lipoprotein the risk for ischaemic stroke can be predicted.


Assuntos
Doenças das Artérias Carótidas/patologia , Lipoproteínas LDL/metabolismo , Estresse Oxidativo , Acidente Vascular Cerebral/patologia , Humanos , Acidente Vascular Cerebral/metabolismo
13.
J Immunol ; 166(6): 4185-94, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11238670

RESUMO

Mouse-to-rat cardiac transplants survive long term after transient complement depletion by cobra venom factor and T cell immunosuppression by cyclosporin A. Expression of heme oxygenase-1 (HO-1) by the graft vasculature is critical to achieve graft survival. In the present study, we asked whether this protective effect was attributable to the generation of one of the catabolic products of HO-1, carbon monoxide (CO). Our present data suggests that this is the case. Under the same immunosuppressive regimen that allows mouse-to-rat cardiac transplants to survive long term (i.e., cobra venom factor plus cyclosporin A), inhibition of HO-1 activity by tin protoporphyrin, caused graft rejection in 3--7 days. Rejection was associated with widespread platelet sequestration, thrombosis of coronary arterioles, myocardial infarction, and apoptosis of endothelial cells as well as cardiac myocytes. Under inhibition of HO-1 activity by tin protoporphyrin, exogenous CO suppressed graft rejection and restored long-term graft survival. This effect of CO was associated with inhibition of platelet aggregation, thrombosis, myocardial infarction, and apoptosis. We also found that expression of HO-1 by endothelial cells in vitro inhibits platelet aggregation and protects endothelial cells from apoptosis. Both these actions of HO-1 are mediated through the generation of CO. These data suggests that HO-1 suppresses the rejection of mouse-to-rat cardiac transplants through a mechanism that involves the generation of CO. Presumably CO suppresses graft rejection by inhibiting platelet aggregation that facilitates vascular thrombosis and myocardial infarction. Additional mechanisms by which CO overcomes graft rejection may involve its ability to suppress endothelial cell apoptosis.


Assuntos
Monóxido de Carbono/metabolismo , Rejeição de Enxerto/metabolismo , Rejeição de Enxerto/prevenção & controle , Transplante de Coração/imunologia , Heme Oxigenase (Desciclizante)/metabolismo , Transplante Heterólogo/imunologia , Doença Aguda , Animais , Apoptose/imunologia , Monóxido de Carbono/administração & dosagem , Monóxido de Carbono/fisiologia , Linhagem Celular , Movimento Celular/imunologia , Endotélio Vascular/enzimologia , Endotélio Vascular/imunologia , Endotélio Vascular/patologia , Endotélio Vascular/fisiopatologia , Exposição Ambiental , Ativação Enzimática/imunologia , Rejeição de Enxerto/enzimologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto/efeitos dos fármacos , Transplante de Coração/patologia , Heme Oxigenase (Desciclizante)/biossíntese , Heme Oxigenase (Desciclizante)/fisiologia , Heme Oxigenase-1 , Macrófagos/patologia , Masculino , Proteínas de Membrana , Camundongos , Camundongos Endogâmicos BALB C , Monócitos/patologia , Músculo Liso Vascular/enzimologia , Músculo Liso Vascular/imunologia , Músculo Liso Vascular/patologia , Músculo Liso Vascular/fisiopatologia , Agregação Plaquetária/imunologia , Ratos , Ratos Endogâmicos Lew , Trombose/patologia , Trombose/prevenção & controle , Transplante Heterólogo/patologia , Regulação para Cima/imunologia
14.
Kidney Int Suppl ; 78: S148-54, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11169001

RESUMO

BACKGROUND: Hypertriglyceridemia, lipid peroxidation, and abnormalities of the plasma fatty acid (PUFA) profile may be important risk factors for the atherosclerotic cardiovascular disease in hemodialysis (HD) patients. METHODS: We investigated how these factors are affected by vitamin E supplementation carried out by oral administration (clinical study 1) and dialysis with vitamin E-modified dialyzers (clinical study 2). RESULTS: In the HD patients, conditions of relative vitamin E deficiency were observed [lowered vitamin E/triglyceride (TG) ratio] in the presence of high levels of thiobarbituric acid reactants (TBARs) and decreased levels of the polyunsaturated fraction of PUFAs paired with an increased amount of monounsaturated ones (MUFA). In both studies, vitamin E supplementation significantly increased the levels of vitamin E in the plasma without affecting TG levels and provided a partial correction of TBAR levels. Of note was the relative increase in the PUFA fraction, which gave solid proof of an anti(per)oxidant effect of vitamin E supplementation in HD patients. Vitamin E supplementation was also observed to increase plasma levels of reduced glutathione and NOx (NO2 + NO3). CONCLUSION: The results suggest that vitamin E supplementation may be an effective accessory therapy to combat oxidative stress-lowering lipid peroxidation in HD patients.


Assuntos
Peroxidação de Lipídeos , Lipídeos/sangue , Diálise Renal/efeitos adversos , Vitamina E , Administração Oral , Adulto , Idoso , Antioxidantes/administração & dosagem , Arteriosclerose/etiologia , Estudos de Casos e Controles , Feminino , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/terapia , Rins Artificiais , Peroxidação de Lipídeos/efeitos dos fármacos , Masculino , Membranas Artificiais , Pessoa de Meia-Idade , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Vitamina E/administração & dosagem
15.
Blood ; 95(11): 3442-50, 2000 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-10828027

RESUMO

Heme arginate infusions blunt the symptoms of patients with acute intermittent porphyria without evidence of the vascular or thrombotic side effects reported for hematin. To provide a rationale for heme arginate's safety, the present study examined the effects of various ferriporphyrins to sensitize human endothelial cells to free radical injury and to induce heme oxygenase and ferritin expression. Heme arginate, unlike hematin, did not amplify oxidant-induced cytotoxicity mediated by hydrogen peroxide (5.3 +/- 2.4 versus 62.3 +/- 5.3% (51)Cr release, P <.0001) or by activated neutrophils (14.4 +/- 2.9 versus 41.1 +/- 6.0%, P <.0001). Nevertheless, heme arginate efficiently entered endothelial cells similarly to hematin, since both markedly induced heme oxygenase mRNA (more than 20-fold increase) and enzyme activity. Even with efficient permeation, endothelial cell ferritin content was only minimally increased by heme arginate compared with a 10-fold induction by hematin; presumably less free iron was derived from heme arginate despite up-regulation of heme oxygenase. Hematin is potentially vasculopathic by its marked catalysis of oxidation of low-density lipoprotein (LDL) to endothelial-toxic moieties. Heme arginate was significantly less catalytic. Heme arginate-conditioned LDL was less than half as cytotoxic to endothelial cells as hematin-conditioned LDL (P <.004). It is concluded that heme arginate may be less vasculotoxic than hematin since it is an effective heme oxygenase gene regulator but a less efficient free-radical catalyst.


Assuntos
Arginina/farmacologia , Deuteroporfirinas/farmacologia , Endotélio Vascular/fisiologia , Compostos Férricos/farmacologia , Ferritinas/genética , Heme Oxigenase (Desciclizante)/genética , Heme/farmacologia , Hemina/farmacologia , Lipoproteínas LDL/sangue , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Regulação da Expressão Gênica , Humanos , Peróxido de Hidrogênio/farmacologia , Lipoproteínas LDL/efeitos dos fármacos , Neutrófilos/fisiologia , Oxirredução , RNA Mensageiro/genética , Acetato de Tetradecanoilforbol/farmacologia , Substâncias Reativas com Ácido Tiobarbitúrico/análise , Transcrição Gênica , Veias Umbilicais
17.
Multivariate Behav Res ; 33(2): 181-220, 1998 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-26771883

RESUMO

We evaluated whether "more is ever too much" for the number of indicators (p) per factor (p/f) in confirmatory factor analysis by varying sample size (N = 50-1000) and p/f (2-12 items per factor) in 35,000 Monte Carlo solutions. For all N's, solution behavior steadily improved (more proper solutions, more accurate parameter estimates, greater reliability) with increasing p/f. There was a compensatory relation between N and p/f: large p/f compensated for small N and large N compensated for small p/f, but large-N and large-p/f was best. A bias in the behavior of the χ(2) was also demonstrated where apparent goodness of fit declined with increasing p/f ratios even though approximating models were "true". Fit was similar for proper and improper solutions, as were parameter estimates form improper solutions not involving offending estimates. We also used the 12-p/f data to construct 2, 3, 4, or 6 parcels of items (e.g., two parcels of 6 items per factor, three parcels of 4 items per factor, etc.), but the 12-indicator (nonparceled) solutions were somewhat better behaved. At least for conditions in our simulation study, traditional "rules" implying fewer indicators should be used for smaller N may be inappropriate and researchers should consider using more indicators per factor that is evident in current practice.

18.
Am J Physiol ; 271(4 Pt 2): F814-23, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8898011

RESUMO

In protein-uric states, renal tubular epithelial cells are exposed to diverse macromolecules, including low-density lipoproteins (LDL), normally excluded from the urinary space. Oxidized LDL (LDLox) is incriminated in atherogenesis and glomerulosclerosis. Since urine is prooxidant, we considered whether LDLox injuries renal tubular epithelial cells (LLC-PK1). We demonstrate that the cytotoxicity of LDLox on LLC-PK1 cells resembles its toxicity to human umbilical vein endothelial cells (HUVEC) in that oxidized but not native LDL is injurious. Pretreatment of LLC-PK1 cells and HUVEC with antioxidants markedly reduced the cytotoxicity of LDLox. Pretreatment of LDL with antioxidants, prior to oxidation of LDL, vitiated its cytotoxicity. That LDLox is prooxidant was supported by expression of heme oxygenase, a redox-sensitive enzyme. LDLox induced heme oxygenase mRNA and enzyme activity. Pretreatment of LDL with antioxidants prior to oxidation attenuated heme oxygenase mRNA induction in LLC-PK1 and HUVEC. An iron chelator prevented cytotoxicity and heme oxygenase expression induced by LDLox. Based on these effects of LDLox, we draw an analogy between tubulointerstitial disease and atherogenesis and speculate that LDLox contributes to tubulointerstitial disease in proteinuric states.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Túbulos Renais/efeitos dos fármacos , Lipoproteínas LDL/farmacologia , Animais , Antioxidantes/farmacologia , Bleomicina , Sobrevivência Celular/efeitos dos fármacos , Endotélio Vascular/citologia , Indução Enzimática/efeitos dos fármacos , Heme Oxigenase (Desciclizante)/metabolismo , Humanos , Ferro/metabolismo , Túbulos Renais/citologia , Células LLC-PK1 , Lipoproteínas LDL/efeitos dos fármacos , Suínos
19.
Free Radic Biol Med ; 20(1): 63-73, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8903680

RESUMO

Ferritin protects endothelial cells from the damaging effects of iron-catalyzed oxidative injury. Regulation of ferritin occurs through the formation of an iron-sulfur cluster within a cytoplasmic protein, the iron regulatory protein (IRP) that controls ferritin mRNA translation. Nitric oxide has been shown to inhibit iron-sulfur proteins and is present at vascular sites of inflammation; therefore, we undertook a study to examine the influence of nitric oxide on changes in endothelial cell ferritin content in response to iron exposure, and the subsequent effects on susceptibility to oxidative injury. Iron-loaded endothelial cells (EC) exposed to nitric oxide donors synthesize markedly less ferritin. Treatment of EC with a nitric oxide donor increases IRP affinity for ferritin mRNA concomitant with a loss of cytoplasmic aconitase activity in iron-laden EC. Iron-treated EC exposed to NO donors were resistant to oxidative injury despite their low ferritin content when examined 1 h after the treatment period. In contrast, 24 h later, these same cells become sensitive to oxidants, whereas iron-treated EC that are ferritin-rich continue to be resistant. In conclusion, NO inhibits the increase of EC ferritin after exposure to iron but provides short-term protection against oxidants; ferritin, in turn, provides durable cytoprotection by inactivating reactive iron.


Assuntos
Endotélio/metabolismo , Ferritinas/metabolismo , Proteínas Ferro-Enxofre/metabolismo , Óxido Nítrico/farmacologia , Proteínas de Ligação a RNA/metabolismo , Aconitato Hidratase/antagonistas & inibidores , Aconitato Hidratase/metabolismo , Animais , Aorta/metabolismo , Sequência de Bases , Northern Blotting , Células Cultivadas , Sondas de DNA/química , Ferritinas/antagonistas & inibidores , Heme Oxigenase (Desciclizante)/metabolismo , Hemina/metabolismo , Humanos , Compostos de Ferro/metabolismo , Compostos de Ferro/farmacologia , Proteínas Reguladoras de Ferro , Dados de Sequência Molecular , Estresse Oxidativo , Penicilamina/análogos & derivados , Penicilamina/metabolismo , Poliaminas/metabolismo , RNA Mensageiro/metabolismo , S-Nitroso-N-Acetilpenicilamina , Suínos/metabolismo , Veias Umbilicais/metabolismo , Vasodilatadores/farmacologia
20.
Work ; 7(3): 191-202, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-24441752

RESUMO

Standardized measurement of workplace performance or the functional assessment of an individual's capabilities, especially by occupational therapists, is often critical before injured workers are returned to work, placed in new jobs, or evaluated for job incapacity. A direct link between a clinician's systematic findings and the detailed requirements of the workplace is desirable. There are a range of vocational evaluation systems available. This study examines how one of these systems, WorkAbility Mark III, incorporates a work measurement technique of industrial engineering into occupational therapy practice. The results of this study suggest that functional assessment with WorkAbility Mark III has benefits for the major stakeholders in occupational rehabilitation; that WorkAbility Mark III tests and uses six activity groups of workplace elements throughout the work assessment process; and that computer technology in this area of occupational rehabilitation can assist the clinician in his or her assessment, planning, intervention, and evaluation.

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