RESUMEN
OBJECTIVES: Circulating levels of matrix metalloproteinase (MMP)-10 are related to inflammation in asymptomatic subjects with cardiovascular risk factors. Whether MMP-10 is associated with the severity of atherosclerosis remains to be determined. This study examines the relationship of systemic MMP-10 levels with atherosclerotic risk factors and subclinical atherosclerosis. METHODS AND RESULTS: Circulating levels of MMP-1, -9 and -10, and markers of inflammation [fibrinogen, interleukin-6, von Willebrand factor, and high-sensitivity C-reactive protein (hs-CRP)] were measured in 400 subjects (mean age 54.3 years, 77.7% men) with cardiovascular risk factors but free from clinical cardiovascular disease. Subclinical atherosclerosis was evaluated by both the mean carotid intima-media thickness (IMT) and the presence of atherosclerotic plaques with the use of B-mode ultrasound in all subjects. MMP-10 levels were positively correlated with fibrinogen (r = 0.24, P < 0.001), hs-CRP (r = 0.14, P < 0.01) and carotid IMT (r = 0.17, P < 0.01). The association between MMP-10 and IMT remained significant in multiple regression analysis (P < 0.02) when controlling for traditional atherosclerotic risk factors and inflammatory markers. Such an association was not observed for MMP-1 and -9. Subjects in the highest MMP-10 tertile had significantly higher carotid IMT (adjusted odds ratio 6.3, 95% confidence interval 1.3-31.4, P = 0.024). In addition, MMP-10 levels were significantly higher in patients with carotid plaques (n = 78) than in those with no plaques after adjusting for age and sex (P < 0.01). CONCLUSION: Higher serum MMP-10 levels were associated with inflammatory markers, increased carotid IMT and atherosclerotic plaques in asymptomatic subjects. Circulating MMP-10 may be useful to identify subclinical atherosclerosis in subjects free from cardiovascular disease.
Asunto(s)
Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/enzimología , Arteria Carótida Común/diagnóstico por imagen , Metaloproteinasa 10 de la Matriz/sangre , Túnica Íntima/diagnóstico por imagen , Túnica Media/diagnóstico por imagen , Proteína C-Reactiva/metabolismo , Enfermedades Cardiovasculares/diagnóstico por imagen , Enfermedades Cardiovasculares/enzimología , Enfermedades de las Arterias Carótidas/sangre , Enfermedades de las Arterias Carótidas/etiología , Femenino , Fibrinógeno/metabolismo , Humanos , Interleucina-6/sangre , Modelos Lineales , Modelos Logísticos , Masculino , Metaloproteinasa 1 de la Matriz/sangre , Metaloproteinasa 9 de la Matriz/sangre , Persona de Mediana Edad , Oportunidad Relativa , Factores de Riesgo , Índice de Severidad de la Enfermedad , Ultrasonografía , Factor de von Willebrand/metabolismoRESUMEN
BACKGROUND: Cyclooxygenase (COX)-2, a key regulatory enzyme in prostanoid synthesis, plays an important role in inflammatory processes. The -765G>C COX-2 polymorphism has been associated with lower promoter activity in vitro and reduced levels of C-reactive protein (CRP) in atherosclerotic carriers of the C allele. However, its pathophysiological relevance in vivo has not been fully elucidated. METHODS AND RESULTS: We assessed the -765G>C polymorphism and COX-2 expression in 220 asymptomatic subjects free of cardiovascular disease, in relation to global vascular risk, carotid intima-media thickness (IMT), and inflammatory markers (fibrinogen, C-reactive protein [CRP], von Willebrand factor [vWF] and interleukin-6 [IL-6]). Genotype frequencies were: CC (7.7%), CG (34.5%), GG (57.7%). Among hypercholesterolemic subjects (n=140), C allele carriers had lower COX-2 expression (p<0.05), reduced carotid IMT (p<0.01) and diminished levels of inflammatory markers CRP, vWF and IL-6 (p<0.05), as compared to GG homozygous subjects. The association between carotid IMT and COX-2 polymorphism remained significant after adjusting for cardiovascular risk factors and inflammatory markers (p=0.008). CONCLUSIONS: In asymptomatic hypercholesterolemic subjects the C allele of -765G>C COX-2 polymorphism was associated with lower COX-2 expression, and reduced subclinical atherosclerosis and systemic inflammation compared with GG homozygous, thus conferring atherosclerosis protection in this cardiovascular risk population.
Asunto(s)
Aterosclerosis/diagnóstico , Aterosclerosis/genética , Ciclooxigenasa 2/genética , Cisteína/genética , Glicina/genética , Polimorfismo Genético/genética , Aterosclerosis/clasificación , Aterosclerosis/enzimología , Biomarcadores , Colesterol/sangre , Femenino , Regulación Enzimológica de la Expresión Génica , Predisposición Genética a la Enfermedad , Humanos , Inflamación , Masculino , Persona de Mediana Edad , Monocitos/enzimologíaRESUMEN
Von Willebrand factor (VWF) is considered a reliable marker of endothelial damage. Plasma levels of VWF were measured in 857 middle-aged subjects (80.4% men) free of clinically overt atherosclerotic disease, in relation to cardiovascular risk factors, carotid intima-media thickness (IMT) and microalbuminuria, two established surrogate markers of atherosclerosis. There was linear trend for the increase of VWF, carotid IMT (p < 0.001) and microalbuminuria (p = 0.018). The association between VEF and both markers remained statistically significant after adjusting for cardiovascular risk factors and inflammatory markers (p < 0.01). In conclusion, VWF was independently associated with both structural and functional surrogates of atherosclerosis in asymptomatic subjects, thus representing a systemic biomarker of subclinical atherosclerosis.
Asunto(s)
Arteriosclerosis/sangre , Arteriosclerosis/diagnóstico , Factor de von Willebrand/biosíntesis , Adulto , Anciano , Albuminuria/metabolismo , Biomarcadores , Pruebas de Coagulación Sanguínea/métodos , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Factores de Riesgo , Túnica Íntima/patología , Túnica Media/patología , Enfermedades Vasculares/diagnósticoRESUMEN
It is now widely accepted that atherosclerosis is a complex chronic inflammatory disorder of the arterial tree associated with several risk factors. From the initial phases of leukocyte recruitment to eventual rupture of vulnerable atherosclerotic plaques, a low-grade inflammation, also termed microinflammation, appears to play a key pathogenetic role. Experimental and clinical evidence suggests that cyclooxygenase-2 (COX-2), an enzyme which catalyzes the generation of prostaglandins from arachidonic acid, also contributes to lesion formation. COX-2 has been detected in macrophages, smooth muscle cells and endothelial cells in human atherosclerotic lesions. Several studies have also reported the presence of COX-2 in the shoulder region of atherosclerotic plaques, mainly colocalizing with macrophages and MMPs, enzymes that are involved in the destabilization of atherosclerotic plaques, leading to rupture and atherothrombotic syndromes (i.e. acute myocardial infarction). We have recently assessed monocyte COX-2 activity and the production of PGE(2) in a population of apparently healthy subjects free from clinically overt atherosclerosis. We found an association between increased PGE(2) and increasing number of cardiovascular risk factors and carotid intima-media thickness, a noninvasive surrogate marker of atherosclerosis, independently of traditional and non traditional cardiovascular risk factors. Our findings support the notion that the COX-2/PGE(2)axis may have a role in atherosclerosis, and this might be an attractive therapeutic target. COX-2 inhibitors, collectively called coxibs (celecoxib, rofecoxib, valdecoxib, lumiracoxib, etc), held a promise of improved treatment of arthritis without the gastrointestinal side effects associated with aspirin and other nonsteroidal anti-inflammatory drugs. However, clinical studies raise several clinically relevant questions as to their beneficial role in atherosclerosis prevention, because of increased thrombogenicity and cardiovascular risk. Only well designed large scale clinical trials can provide the answer as to the net effect of selective COX-2 inhibition on cardiovascular events before this new class of anti-inflammatory drugs can be incorporated into the armamentarium of atherosclerosis.
Asunto(s)
Arteriosclerosis/tratamiento farmacológico , Inhibidores de la Ciclooxigenasa/uso terapéutico , Monocitos/enzimología , Prostaglandina-Endoperóxido Sintasas/sangre , Arteriosclerosis/enzimología , Arteriosclerosis/fisiopatología , Ciclooxigenasa 2 , Inhibidores de la Ciclooxigenasa 2 , Dinoprostona/metabolismo , Humanos , Proteínas de la Membrana , Prostaglandina-Endoperóxido Sintasas/fisiologíaRESUMEN
BACKGROUND: We examined the influence of the 4G/5G PAI-1 (plasminogen activator inhibitor) genotype on Angiotensin II (Ang II)-induced PAI-1 expression by human endothelial cells (HUVEC) in the presence and absence of AT1-receptor blocker losartan, and screened for this polymorphism in relation to plasma PAI-1 and arterial pressure in apparently healthy subjects. METHODS AND RESULTS: Genotyped cultured HUVEC were incubated with Ang II (10(-8) M) with or without losartan up to 24 h. PAI-1 mRNA was determined in cell extracts and protein and activity assessed in supernatants and extracellular matrix (ECM). Ang II increased PAI-1 mRNA and activity in a genotype-dependent manner, higher values observed for 4G/4G HUVEC compared with 4G/5G and 5G/5G genotypes (p<0.05). Laser confocal microscopy and Western blot analysis showed increased PAI-1 protein within ECM in Ang II-stimulated cultures. PAI-1 expression and protein secretion induced by Ang II in 4G/4G HUVEC was completely inhibited by preincubation with 0.05 microM losartan (p<0.01), indicating an AT1-mediated effect. In a group of hypertensives homozygous for the 4G allele, PAI-1 antigen was significantly increased (51.0+/-10.1 ng/ml) compared with normotensives (28.3+/-4.0 ng/ml) and hypertensives carrying the 5G allele (p<0.05). CONCLUSIONS: The 4G/5G PAI-1 polymorphism determines the endothelial PAI-1 upregulation by Ang II and the inhibitory response to losartan. Analysis of PAI-1 genotypes may help identifying subgroups of hypertensives at higher cardiovascular risk.
Asunto(s)
Angiotensina II/farmacología , Células Endoteliales/metabolismo , Hipertensión/metabolismo , Inhibidor 1 de Activador Plasminogénico/genética , Polimorfismo Genético , Análisis de Varianza , Bloqueadores del Receptor Tipo 1 de Angiotensina II , Estudios de Casos y Controles , Células Cultivadas , Femenino , Fibrinólisis , Marcadores Genéticos , Genotipo , Humanos , Losartán/farmacología , Masculino , Persona de Mediana Edad , Inhibidor 1 de Activador Plasminogénico/inmunología , Inhibidor 1 de Activador Plasminogénico/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Estadísticas no Paramétricas , Estimulación QuímicaRESUMEN
BACKGROUND AND PURPOSE: Thrombin, a central enzyme in the clotting cascade, plays a role not only in thrombosis but also in the progression of atherosclerosis. We studied the relationship between prothrombin fragment 1+2 (F1+2), a specific marker of thrombin generation in vivo, and carotid intima-media thickness (IMT), an index of subclinical atherosclerosis. METHODS: We examined 181 asymptomatic middle-aged subjects (mean age 55.6 years, 76.7% men) free of overt clinical atherosclerotic disease. F1+2 was measured by enzyme-linked immunosorbent assay and IMT by duplex ultrasonography of carotid artery. Multiple linear regression analysis was used to assess the relationship between the 2 parameters. RESULTS: Compared with individuals in the lowest tertile of F1+2, those in the upper tertile (>0.55 nmol/L) showed significantly higher IMT (P<0.01). In correlation analysis, a positive relationship was found between plasma F1+2 and carotid IMT. F1+2 also correlated positively with cholesterol (P<0.008) and low-density lipoprotein cholesterol (P<0.005), but not with blood pressure or body mass index. In the multivariate analysis, the association of F1+2 with carotid IMT remained significant (P<0.001) after adjustment for age, sex, body mass index, systolic blood pressure, cholesterol, diabetes, and smoking. CONCLUSIONS: In a population sample of adults without clinically overt atherosclerotic disease, the plasma levels of F1+2 were significantly associated with carotid IMT, suggesting a relationship between thrombin generation and the development atherosclerosis.
Asunto(s)
Arteriosclerosis , Enfermedades de las Arterias Carótidas/sangre , Enfermedades de las Arterias Carótidas/patología , Fragmentos de Péptidos/sangre , Túnica Íntima/patología , Arteriosclerosis/etiología , Arterias Carótidas/diagnóstico por imagen , Arterias Carótidas/patología , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Ensayo de Inmunoadsorción Enzimática/estadística & datos numéricos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Protrombina , Análisis de Regresión , Factores de Riesgo , Túnica Íntima/diagnóstico por imagen , Ultrasonografía Doppler Dúplex/estadística & datos numéricosRESUMEN
It has been reported that hepatitis C virus (HCV) may cause oxidative stress in infected cells. Patients with chronic hepatitis C exhibit an increased production of tumor necrosis factor-alpha (TNF alpha), a cytokine that can produce oxidative stress by stimulating the generation of reactive oxygen species (ROS). Cell defense against ROS includes overexpression of Mn-superoxide dismutase (SOD), an inducible mitochondrial enzyme. To investigate cell defense against oxidative stress in HCV infection, we analyzed Mn-SOD mRNA in liver and in peripheral blood mononuclear cells (PBMC) from patients with chronic hepatitis C. Mn-SOD expression in PBMC was significantly increased in patients with HCV infection. Patients with sustained virological and biochemical response after therapy showed significantly lower Mn-SOD than patients with positive viremia. By contrast, Mn-SOD expression was not enhanced in the liver of patients with chronic hepatitis C. The values of Mn-SOD mRNA did not correlate with TNF alpha mRNA expression, viral load, or liver disease activity. Our results indicate that in HCV infection an induction of Mn-SOD was present in PBMC but absent in the liver, suggesting that this organ could be less protected against oxidative damage. Oxidative stress could participate in the pathogenesis of HCV infection.
Asunto(s)
Hepatitis C Crónica/enzimología , Superóxido Dismutasa/genética , Adulto , Anciano , Secuencia de Bases , Cartilla de ADN/genética , Femenino , Radicales Libres/metabolismo , Expresión Génica , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Hepatitis C Crónica/sangre , Hepatitis C Crónica/genética , Humanos , Leucocitos Mononucleares/enzimología , Hígado/enzimología , Masculino , Persona de Mediana Edad , Estrés Oxidativo , ARN Mensajero/sangre , ARN Mensajero/metabolismo , ARN Viral/sangre , ARN Viral/genética , Factor de Necrosis Tumoral alfa/genética , Viremia/sangre , Viremia/enzimología , Viremia/genéticaRESUMEN
The glutathione-glutathione peroxidase system is an important defense against oxidative stress. The ability of this system to protect against iron-catalyzed microsomal production of hydroxyl radicals [oxidation of 4-methylmercapto-2-oxo-butyrate (KMBA)] and lipid peroxidation was evaluated. When rat liver cytosol was added to microsomes, strong inhibition against KMBA oxidation was observed. No protection was found when the cytosol was boiled or dialyzed. In the latter case, the addition of 0.5 mM glutathione restored almost complete protection, whereas in the former case protection could be restored by the addition of both glutathione and glutathione peroxidase. Cysteine could not replace glutathione, nor could glutathione S-transferase replace glutathione peroxidase. The glutathione-glutathione peroxidase system was also very effective in decreasing production of hydroxyl radicals stimulated by the addition of menadione or paraquat to microsomes. In the absence of cytosol, the addition of glutathione plus glutathione peroxidase was also effective; however, 5 mM glutathione was necessary to protect against KMBA oxidation. The effective concentration of glutathione required for protection was lowered when glutathione reductase was added to the system, to regenerate reduced glutathione. These results indicate that low concentrations of glutathione in conjunction with glutathione peroxidase plus reductase can be very effective in preventing microsomal formation of hydroxyl radicals catalyzed by iron and other toxic compounds. Microsomal lipid peroxidation was decreased 40% by glutathione alone, and this decrease was potentiated in the presence of glutathione reductase. In contrast to KMBA oxidation, the combination of glutathione plus glutathione peroxidase was not any more effective than glutathione alone in preventing lipid peroxidation. The differences in sensitivities of microsomal lipid peroxidation and KMBA oxidation to glutathione peroxidase suggest that these two processes can be distinguished from each other, and that free H2O2 and hydroxyl radicals are involved in KMBA oxidation, but not lipid peroxidation.
Asunto(s)
Glutatión Peroxidasa/metabolismo , Glutatión/metabolismo , Hidróxidos , Peróxidos Lipídicos/metabolismo , Microsomas Hepáticos/metabolismo , Animales , Butiratos/metabolismo , Citosol/metabolismo , Glutatión Transferasa/metabolismo , Radical Hidroxilo , Masculino , Cloruro de Potasio/farmacología , Ratas , Ratas Endogámicas , Compuestos de SulfhidriloRESUMEN
BACKGROUND: Because the prognosis of patients with hepatocellular carcinoma is not fully understood, particularly regarding therapy, we have evaluated it in a series of patients with a homogeneous diagnostic and therapeutic work-up. METHODS: From 1985 to 1996, 42 variables were recorded prospectively in 178 constructive patients who had a diagnosis of hepatocellular carcinoma. Treatment consisted of liver transplantation ( n = 22), partial hepatectomy (n = 11), arterial, chemoembolization ( n = 52), systemic or regional chemotherapy (n = 51), and other therapies (n = 5); 37 patients received no specific therapy. Statistical analysis was performed according to a Cox model. RESULTS: There were no differences between the survival of patients receiving chemotherapy, other therapies, or no treatment (control group n = 93). survival rates a 1,3, and 5 years were 81%, 74%, and 74% for liver transplantation, 72%, 58%, and 58% for hepatectomy, 55%, 26%, and 13% for chemoembolization, and 13%, 3%, and 0% for the control group. Cirrhosis, systemic syndrome, bilobar involvement, Child's stage C disease, and treatment were independent predictors of survival. CONCLUSIONS: This series shows that certain easily accessible parameters may help establish individual prognosis and stratify patients in clinical trials and indicates that chemoembolization, partial resection, and liver transplantation can prolong life expectancy of patients with hepatocellular carcinoma.
Asunto(s)
Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/terapia , Quimioembolización Terapéutica , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/terapia , Europa (Continente)/epidemiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Pronóstico , Análisis de SupervivenciaRESUMEN
In the treatment of active chronic hepatitis and hepatocellular carcinoma some effective drugs can produce myelosuppression. Hypersplenism may considerably limit the dosage of such drugs. Splenectomy is an effective treatment for hypersplenism, although it is not without complications. Partial splenic embolization is a good and safe procedure; 15 patients were treated in order to achieve higher platelet and leukocyte counts. Embolization has been performed with gelfoam with local and systemic antibiotics (Spigos' protocol) and 50-75% of the splenic parenchyma was infarcted. All patients could be treated for the underlying hepatopathy with adequate dosages of interferon or chemotherapeutic drugs.
Asunto(s)
Carcinoma Hepatocelular/terapia , Embolización Terapéutica/métodos , Hepatitis Crónica/terapia , Neoplasias Hepáticas/terapia , Anciano , Embolización Terapéutica/efectos adversos , Femenino , Esponja de Gelatina Absorbible , Humanos , Huésped Inmunocomprometido , Masculino , Persona de Mediana Edad , BazoRESUMEN
We describe the case of a 51 year-old man affected of relapsing bouts of abdominal pain and hematuria, who began acutely with pain in the right upper quadrant, fever, hematuria, arthralgias and purpura on the lower extremities; ultrasonography revealed the existence of acalculous cholecystitis. The lack of response to intravenous antibiotherapy and the clinical association of cholecystitis to the renal, cutaneous and articular manifestations, oriented to the diagnosis of Schöenlein-Henoch vasculitis; thereafter, the response to steroids was successful and immediate. The etiologic diagnosis of this case of acalculous cholecystitis based on clinical aspects, avoid the surgical therapy and the possible morbidity that this procedure can produce.
Asunto(s)
Colecistitis/etiología , Vasculitis por IgA/complicaciones , Artralgia/etiología , Colecistitis/diagnóstico por imagen , Colelitiasis/diagnóstico , Crioglobulinemia/complicaciones , Diagnóstico Diferencial , Hematuria/etiología , Humanos , Masculino , Persona de Mediana Edad , UltrasonografíaRESUMEN
Antiphospholipid syndrome is a well-defined clinical and serological entity characterized by arterial and/or venous thrombosis, recurrent abortion and thrombocytopenia. Anticardiolipin antibodies and lupus anticoagulant are autoantibodies directed against negatively charged phospholipids, which represent the serologic criteria for the diagnosis of the antiphospholipid syndrome. In this review the pathogenic mechanisms of anticardiolipin antibodies, their clinical findings and the current therapeutical strategies are discussed.
Asunto(s)
Síndrome Antifosfolípido , Enfermedades Autoinmunes , Aborto Habitual/etiología , Aborto Habitual/prevención & control , Animales , Anticuerpos Antifosfolípidos/inmunología , Anticoagulantes/uso terapéutico , Síndrome Antifosfolípido/diagnóstico , Síndrome Antifosfolípido/etiología , Síndrome Antifosfolípido/inmunología , Síndrome Antifosfolípido/terapia , Enfermedades Autoinmunes/diagnóstico , Enfermedades Autoinmunes/etiología , Enfermedades Autoinmunes/inmunología , Enfermedades Autoinmunes/terapia , Transfusión de Componentes Sanguíneos , Enfermedades del Tejido Conjuntivo/complicaciones , Femenino , Predisposición Genética a la Enfermedad , Glicoproteínas/inmunología , Antígenos HLA-D/genética , Antígenos HLA-D/inmunología , Inmunosupresores/uso terapéutico , Infecciones/complicaciones , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos MRL lpr , Imitación Molecular , Neoplasias/complicaciones , Embarazo , Trombocitopenia/tratamiento farmacológico , Trombocitopenia/etiología , Terapia Trombolítica , Trombofilia/tratamiento farmacológico , Trombofilia/etiología , beta 2 Glicoproteína IRESUMEN
Idiopathic hemochromatosis is an inherited and primary disease. Its definition requires: a) a family history of abnormalities of iron storage; b) an association with HLA; c) inadequate iron absorption in relation to iron stores in liver and other territories; d) the absence of any other known causes of iron overload. The recent evidence of its high family related frequency and the existence of an effective treatment, demand the understanding of this entity and the strongest medical effort towards the diagnosis in the pre-cirrhotic stages. We present here the results from the study of 17 patients diagnosed of idiopathic hemochromatosis over a seven year period in the University Clinic of Navarra. Our aim is to review this subject and to compare our findings with those described in the current literature.
Asunto(s)
Hemocromatosis/genética , Adulto , Anciano , Eliminación de Componentes Sanguíneos , Venodisección , Terapia Combinada , Deferoxamina/uso terapéutico , Diagnóstico Diferencial , Femenino , Hemocromatosis/diagnóstico , Hemocromatosis/terapia , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Neurofibromatosis (Von Recklinghausen's disease) is uninherited as an autosomal dominant trait. It is characterised by the development of tumors in diverse sites, which may be benign or malignant. The case of a 39 year old woman with Von Recklinghausen's disease is discussed. She presented with a 3 year history of episodes of melaena and iron deficient anaemia. Mesenteric angiography demonstrated a hypervascular tumour in the jejunum. It was surgically excised with an anatomopathological diagnosis of neurofibroma.
Asunto(s)
Hemorragia Gastrointestinal/etiología , Neurofibromatosis 1/complicaciones , Adulto , Femenino , HumanosRESUMEN
McArdle's disease (glycogenosis type V) is a metabolic disorder of hydrocarbons, inherited with autosomic recessive pattern. Biochemically is defined by a myophosphorylase deficiency; clinically it is characterized by exercise intolerance, due to the impossibility of providing energetic substrate to the muscle, myalgias and stiffness. We present a case report of a patient with McArdle's disease and we comment the diagnostic procedures and current therapeutic options.
Asunto(s)
Enfermedad del Almacenamiento de Glucógeno Tipo V/diagnóstico , Fosforilasas/deficiencia , Adulto , Creatina Quinasa/sangre , Proteínas en la Dieta/uso terapéutico , Glucógeno/análisis , Enfermedad del Almacenamiento de Glucógeno Tipo V/dietoterapia , Enfermedad del Almacenamiento de Glucógeno Tipo V/genética , Enfermedad del Almacenamiento de Glucógeno Tipo V/metabolismo , Glucólisis , Humanos , Masculino , Músculo Esquelético/química , Músculo Esquelético/patología , Mioglobinuria/etiología , Esfuerzo FísicoAsunto(s)
Hepatitis C/complicaciones , Adolescente , Adulto , Anciano , Autoanticuerpos/análisis , Enfermedades Autoinmunes/etiología , Enfermedades Autoinmunes/inmunología , Niño , Preescolar , Crioglobulinemia/etiología , Femenino , Glomerulonefritis Membranoproliferativa/etiología , Hepacivirus/inmunología , Anticuerpos contra la Hepatitis C/análisis , Humanos , Masculino , Persona de Mediana Edad , Porfiria Cutánea Tardía/etiología , Síndrome de Sjögren/etiología , Enfermedades de la Piel/etiologíaRESUMEN
The addition of menadione or paraquat to rat liver microsomes resulted in about a threefold increase in the production of hydroxyl radical (.OH) as reflected by the increased oxidation of 2-keto-4-thiomethylbutyric acid (KMBA) to ethylene. This increase was not sensitive to superoxide dismutase but was blocked by catalase. The increase occurred in the absence of added iron and was not affected by the potent iron chelating agent, desferrioxamine, which suggests the possibility that .OH was produced from an interaction between H2O2 and the paraquat or menadione radical. Menadione and paraquat were especially effective in stimulating the oxidation of KMBA in the presence of certain iron chelates such as ferric-ADP, -ATP, or -EDTA, but not ferric-desferrioxamine, -citrate, or -histidine, or unchelated iron. In fact, ferric-ADP or -ATP only stimulated .OH production in the presence of menadione or paraquat. In the presence of ferric-EDTA, the greater than additive increase of .OH production was sensitive to catalase, but not to superoxide dismutase, suggesting the possibility of reduction of ferric-EDTA by paraquat or menadione radical. The interactions with ferric adenine nucleotides may increase the catalytic effectiveness of menadione or paraquat in producing potent oxidants such as the hydroxyl radical, and thus play a role in the toxicity associated with these agents. Paraquat and menadione had little effect on the overall oxidation of ethanol by microsomes. Microsomal drug metabolism was decreased by menadione or paraquat. As a consequence, the effect of these agents on the microsomal oxidation of ethanol was complex since it appeared that paraquat and menadione stimulated the oxidation of ethanol by a .OH-dependent mechanism, but inhibited the oxidation of ethanol by a cytochrome P-450-dependent oxidation pathway. Experiments with carbon monoxide, ferric-EDTA, and 2-butanol plus catalase tended to verify that microsomal oxidation of alcohols was increased by a .OH-dependent pathway when menadione or paraquat were added to microsomes.