RESUMO
BACKGROUND: Endothelial dysfunction in cigarette smokers has been ascribed to increased oxidative damage. The aims of the present study were to compare the endothelial function of normotensive smokers with that of non-smokers and to examine its relation to some parameters representative of oxidative damage and of antioxidant capacity. METHODS: We investigated 32 chronic smokers (15-30 cigarettes daily) affected by coronary heart disease, ranging from acute myocardial infarction to instable angina pectoris, and 28 matched non-smokers without any definite risk factors. All subjects underwent assessment of nitric oxide (NO)-dependent endothelial function, measured as brachial artery vasodilatation in response to reactive ischemia, using a standardized echographic method. Plasma and urinary levels of NO were also measured in all subjects, as were urinary 15-isoprostane F(2t), plasma serum lipids, homocysteine (Hcy), ascorbic acid, retinol, tocopherol, and alpha- and beta-carotene (by high-performance liquid chromatography). RESULTS: Smokers showed a significantly lower NO-mediated vasodilatation response (3.50% vs. 6.18%, p<0.001) and higher levels of urinary NO metabolites and 15-isoprostane F(2t). They also had higher levels of Hcy (p<0.001); these values were significantly and inversely related to NO serum levels (r=-0.512, p<0.001). Moreover, smokers had a significant and corresponding reduction in circulating levels of ascorbic acid, tocopherol, and alpha- and beta-carotene. CONCLUSIONS: The present study shows a clear relation between endothelial dysfunction (NO production impairment) and cigarette smoking, especially in the presence of high levels of LDL-cholesterol. It also defines some markers of both oxidative damage and antioxidant protective capacity in this condition. The monitoring of these factors may be advisable in order to assess the amount of endothelial damage.
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Given the crucial role of iron and porphyrins in oxidative cellular damage in the chronic porphyrias, we undertook an extensive study in families with acute porphyrias to evaluate the possible role of similar oxidative damage in these diseases, whose natural history is often also complicated by neoplastic evolution. Four unrelated patients with acute intermittent porphyria (AIP) were studied together with 37 members of four different families. Aminolevulinic acid and porphobilinogen were measured in urine, and porphyrins in urine, plasma and stools. The activity of the congenitally deficient enzyme, porphobilinogen deaminase, and the concentrations of plasma iron, transferrin, ferritin, and various antioxidants (ascorbic acid, retinol, tocopherol, alpha- and beta-carotene, by a personal HPLC method) and the urinary and plasma metabolites of nitrous oxide were also assayed. The results showed no relationship between the observed increase of porphyrin metabolites and the presence of markers of oxidative damage or the decrease of circulating antioxidants: however, when such a decrease was registered, it depended on spontaneous or iatrogenic iron accumulation. We conclude that family screening, recommended for the identification of AIP carriers, must also include evaluation of iron stores with a view to preventing the oxidative damage and in order to forestall the neoplastic evolution of the disease.
Assuntos
Antioxidantes/metabolismo , Oxidantes/sangue , Porfiria Aguda Intermitente/genética , Porfiria Aguda Intermitente/metabolismo , Adolescente , Adulto , Idoso , Carotenoides/sangue , Criança , Eritrócitos/metabolismo , Saúde da Família , Fezes , Feminino , Humanos , Hidroximetilbilano Sintase/metabolismo , Ferro/sangue , Masculino , Pessoa de Meia-Idade , Óxido Nitroso/metabolismo , Linhagem , Porfirinas/urina , Protoporfirinas/metabolismo , Vitaminas/sangueRESUMO
Background: It is known that antioxidant liposoluble vitamins and carotenoids are reduced in liver cirrhosis, but little is known about chronic viral hepatitis, where oxidative damage has to be taken into account. Methods: Fifty-five patients with chronic hepatitis, mainly C virus-related, were matched with 16 patients with biliary stones and 20 healthy controls. Plasma and liver analyses were carried out using a well-tried HPLC technique that affords an accurate quantification of retinol, tocopherol, alpha- and beta-carotene, cryptoxanthin, and lycopene. Results: Plasma concentration of retinol, tocopherol, beta-carotene, and lycopene was significantly decreased in both patient groups, particularly in those with chronic hepatitis. In contrast, liver concentration of both esterified and free retinol, tocopherol, and some carotenoids was better preserved in the hepatitis group than in the cholelithiasis group. A strict correspondence between aminotransferases and the amount of liver-stored retinol was documented. Conclusions: Plasma vitamin and carotenoid depletion co-existing with preserved liver storage may indicate a functional defect in liver pool mobilization or even a real depletion of the antioxidant defenses, which play a key role in averting cellular damage. The implications for nutrition and therapy need to be taken into account.
RESUMO
The aim of this study was to evaluate the prognostic factors at presentation and survival in Italian patients with hepatocellular carcinoma (HCC). Clinical and demographic data of 176 patients consecutively observed from 1993 to 1997 were evaluated by univariate and multivariate analyses. Overall median survival was 18 months. At univariate analysis, low albumin, high bilirubin, high alkaline phosphatase, high alpha-fetoprotein (AFP); high platelet count, hepatitis B surface antigen (HBsAg)-positivity, the presence of ascites, of encephalopathy, of portal vein thrombosis (PVT), male sex, no treatment, poor differentiation, untreatable tumours and incidental diagnosis were each associated with shorter survival. HBsAg-positive subjects more often presented with untreatable lesions or diffuse tumours (P=0.001 and P=0.007, respectively) and had significantly worse survival (P=0.0057). By multiple regression analysis, low albumin, high bilirubin, abnormal AFP, presence of PVT and of untreatable lesions were independent risk factors for worse survival. Thus, the most important factors influencing survival are the degree of functional impairment of the liver, the presence of hepatitis B viral (HBV) infection, the type of diagnosis and the aggressiveness of the tumour.
Assuntos
Carcinoma Hepatocelular/mortalidade , Neoplasias Hepáticas/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/virologia , Feminino , Seguimentos , Hepatite B/complicações , Hepatite B/epidemiologia , Hepatite B/patologia , Antígenos de Superfície da Hepatite B/sangue , Hepatite C/complicações , Hepatite C/epidemiologia , Hepatite C/patologia , Humanos , Itália/epidemiologia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/virologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Análise de Sobrevida , Taxa de SobrevidaRESUMO
We analyzed the 1986-1997 mortality in a cohort of 2065 residents of an Italian municipality which had been exposed to drinking water with a high content of inorganic selenium over a long period of time, and compared it with mortality in the remainder of the municipal population. Mortality from malignant neoplasms increased [standardized mortality ratio (SMR) 1.17, 95% confidence interval (CI) 0.96-1.42], mainly due to an excess mortality from melanoma and colorectal cancer in both sexes, kidney cancer in men, and lymphoid malignancies in women. Overall cardiovascular mortality changed little (SMR 1.05, 95% CI 0.89-1.23), despite the higher cerebrovascular mortality (SMR 1.43, 95% CI 1.03-1.93). Coronary disease mortality slightly decreased (SMR 0.87, 95% CI 0.63-1.16), due to a low mortality among women. We also noted an excess mortality from Parkinson's disease in men and from motor neuron disease in women. Evaluation of these findings is, however, hampered by the lack of information about potential lifestyle confounders, the fact that the exposure could only be characterized by a simple dichotomization, and the inconsistencies of most estimates between the two sexes.
Assuntos
Água Doce/química , Mortalidade/tendências , Selênio/efeitos adversos , Poluentes Químicos da Água/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Causas de Morte , Estudos de Coortes , Feminino , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-IdadeRESUMO
We have previously described a mitoxantrone-resistant MCF7 cell line that is cross-resistant to topotecan, 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy-camptothecin (CPT-11), and 9-aminocamptothecin, but not to camptothecin. A novel mechanism that resulted in decreased topotecan accumulation in MCF7/MX cells was proposed (Yang et al. Cancer Res 55: 4004-4009, 1995). We now have developed a topotecan-resistant cancer cell line from wild-type MCF7 cells. MCF7/TPT300 cells were 68.9-fold resistant to topotecan, 68.3-fold to 10-hydroxy-7-ethylcamptothecin (SN-38), and 116-fold to mitoxantrone, but only 4.1-fold to camptothecin. Topotecan efflux was increased in MCF7/TPT300 cells compared with MCF7/WT cells, and this increase was reversed upon ATP depletion by sodium azide, suggesting an energy-dependent drug efflux mechanism. However, MCF7/TPT300 cells did not overexpress P-glycoprotein or the multidrug resistance-associated protein (MRP1). In contrast, overexpression of the breast cancer resistance protein (BCRP/MXR/ABCP) was observed in MCF7/TPT300 cells as well as DNA topoisomerase I down-regulation. Our data suggest that enhanced topotecan efflux contributes partly to topotecan resistance in MCF7/TPT300 cells, possibly mediated by BCRP/MXR/ABCP.
Assuntos
Transportadores de Cassetes de Ligação de ATP/biossíntese , Neoplasias da Mama/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos , Topotecan/farmacologia , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Trifosfato de Adenosina/metabolismo , Antineoplásicos/farmacologia , Transporte Biológico , Neoplasias da Mama/enzimologia , DNA Topoisomerases Tipo I/biossíntese , DNA Topoisomerases Tipo II/biossíntese , Proteínas de Ligação a DNA/biossíntese , Resistencia a Medicamentos Antineoplásicos , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Proteína 3 Homóloga a MutS , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Células Tumorais CultivadasRESUMO
The development of multidrug resistance (MDR) in heterogeneous cell sensitive and resistant populations to a variety of clinically important cytotoxic drugs poses a major obstacle to cancer chemotherapy. Didemnin B, a marine cyclic depsipeptide, displays interesting biological properties: antiviral activity, inhibition of DNA, RNA and protein synthesis, initiation of apoptosis and ability to block the cell cycle. As very little is known about its mode of action, we studied the effect of increasing doses of Didemnin B on sensitive and resistant human leukemic lymphoblast cell lines. The fluorescence of living cells simultaneously stained with Hoechst 33,342, Rhodamine 123 and Nile Red, were analyzed in a multiparametric approach involving multiwavelength microfluorometry. High concentrations of Didemnin B induced, in the sensitive cell line, a very early decrease in the energetic state of the mitochondria that occurs before a significant decrease of nuclear DNA content, observed simultaneously on sensitive and resistant cells, that could be related to an apoptosis process. Furthermore low Didemnin doses (50 nM) affected CEM-WT and CEM VLB differently, while higher doses (200 nM-250 nM and over) affected the two cell lines in the same way. This indicated that, at these doses, the membranar Pgp has no effect on the mode of action of Didemnin, suggesting that Didemnin does not need to be internalized to be active.
Assuntos
Antineoplásicos/toxicidade , Divisão Celular/efeitos dos fármacos , Depsipeptídeos , Resistência a Múltiplos Medicamentos , Peptídeos Cíclicos/toxicidade , Benzimidazóis , Corantes Fluorescentes , Humanos , Cinética , Microscopia de Vídeo , Oxazinas , Leucemia-Linfoma Linfoblástico de Células Precursoras , Rodamina 123 , Células Tumorais Cultivadas , Vimblastina/toxicidadeRESUMO
The products of the ABC gene family can be generally classified as either full-transporters of half-transporters. Full-transporters are expressed in the plasma membrane, whereas half-transporters are usually found in intracellular membranes. Recently, an ABC half-transporter, the ABCG2 gene product Breast Cancer/Mitoxantrone Resistance Protein (BCRP/MXR), has been shown to cause mitoxantrone and topotecan resistance. The purpose of this study was to determine the expression and the intracellular localization of this protein in various drug-resistant cell lines. BCRP/MXR expression was determined by Western blot and immunohistochemistry. This protein is highly overexpressed in several drug-resistant cell lines and localizes predominantly to the plasma membrane, instead of to intracellular membranes as seen with all other known half-transporters. Therefore, BCRP/MXR is unique among the ABC half-transporters by being localized to the plasma membrane.
Assuntos
Transportadores de Cassetes de Ligação de ATP/biossíntese , Membrana Celular/metabolismo , Western Blotting , Neoplasias da Mama/metabolismo , Neoplasias do Colo/metabolismo , Resistencia a Medicamentos Antineoplásicos , Humanos , Imuno-Histoquímica , Microscopia de Fluorescência , Células Tumorais CultivadasRESUMO
Didemnin B (DB), a marine natural product, has very encouraging biological activity in vitro (Antineoplastic, immunosuppressive, antiviral). To learn more about its intracellular effects and targets, videomicrofluorometry on single living cells and a protocol of multiple labeling: Hoechst 342 for nuclear DNA, Rhodamine 123 for mitochondria and Nile Red for plasma membrane, have been used. DB behaves differently from Adriamycin, inducing at its IC50 dose of (20 nM) an accumulation of the CEM-WT lymphoblasts in the S phase of the cell cycle while we observed a 50% decrease of the mitochondrial labeling by R123, showing a decrease of the mitochondrial energetic state. Cytostatic dose of DB (250 nM) confirms these observations. However the treatment with a dose reported as apoptotic (1000 nM) induces a much faster effect (corresponding to that of 72 hours at the IC50 dose), 24 hours incubation induced a drastic decrease of nuclear DNA content as well as of the mitochondria energetic state. The evolution of NAD(P)H cellular content exhibited an increase that seems to indicate that the decrease of mitochondrial energetic state was dependent on inhibition of the mitochondrial activity due to an effect of DB at the mitochondrial level, either direct or mediated. Furthermore, the decrease of mitochondrial labeling appears as a very early event in the mechanisms leading to apoptosis.
Assuntos
Depsipeptídeos , Doxorrubicina/química , Peptídeos Cíclicos/química , Peptídeos Cíclicos/farmacocinética , Apoptose , Benzimidazóis/metabolismo , Ciclo Celular/efeitos dos fármacos , Núcleo Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Doxorrubicina/farmacocinética , Doxorrubicina/farmacologia , Corantes Fluorescentes/metabolismo , Fluorometria , Humanos , Concentração Inibidora 50 , Microscopia de Vídeo , Mitocôndrias/efeitos dos fármacos , Oxazinas/metabolismo , Peptídeos Cíclicos/farmacologia , Rodamina 123/metabolismo , Fatores de Tempo , Células Tumorais CultivadasRESUMO
BACKGROUND: Porphyria cutanea tarda and haemochromatosis are taken to be spontaneous human models of oxidative cellular damage, with an increased risk of fibrosis and cancer evolution. AIM: To define the relative pro-oxidant roles of porphyrin and iron, in their different molecular forms, and their effects on antioxidant biological systems. PATIENTS: A group of 17 patients with porphyria cutanea tarda and a group of 14 patients with primary and secondary haemochromatosis, were compared with 21 healthy controls. METHODS: Plasma retinol, tocopherol, alpha- and beta-carotene, ascorbic acid, glutathione, malonyldialdehyde and red blood cell free iron were determined using high performance liquid chromatography. RESULTS: Only a modest increase in iron stores was demonstrated in the porphyria cutanea tarda group; in the haemochromatosis patients ferritin levels were almost seven times higher. By contrast, there was a sharp and virtually identical increase in red blood cell free iron and malonyldialdehyde in both the patient groups. A significant reduction was observed in retinol, alpha-, beta-carotene and red blood cell glutathione levels being more marked in porphyria cutanea tarda than in haemochromatosis patients. CONCLUSIONS: The study confirms the strong pro-oxidant effects of porphyrins in vivo, through an induction of the free toxic iron form, even though the total iron pool is not greatly expanded. The additional free-iron and porphyrin oxidant effects are documented both in red blood cell and plasma in the porphyria cutanea tarda group. It confirmed that aging exerts a negative influence in terms of pro- and antioxidant balance in all cases, but particularly in the haemochromatosis group.
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Hemocromatose/sangue , Porfiria Cutânea Tardia/sangue , Antioxidantes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Espécies Reativas de OxigênioRESUMO
The development of multidrug resistance (MDR) in heterogeneous cell sensitive and resistant populations to a variety of clinically important cytotoxic drugs poses a major obstacle to cancer chemotherapy. The MDR phenotype is characterized by a decrease the intracellular drug accumulation and by an overexpression of the MDR1 gene which encodes the membrane protein, P-glycoprotein (Pgp). To evaluate the MDR phenotype, rationale investigations of the cytotoxic processes and effect,s of Adriamycin (ADR) were done to obtain information on individual cells. Such information could be obtained through a multiparametric approach involving multiwavelength microfluorometry and numerical image analysis on single living cells. To achieve this, cells should be simultaneously stained with Hoechst 33342 (nuclear staining), Rhodamine 123 (mitochondria staining) and Nile Red (cell contour delineation). Changes in the biological parameters accessible from R123, Ho33342 and C-SNARF-1/AM (probe used for the pHi measurements) labelling were found more informative than changes in morphological parameters for the discrimination of sensitive and resistant cells. Furthermore, this approach allows the discrimination between two resistant cell lines expressing different mechanisms of resistance.
Assuntos
Doxorrubicina/farmacologia , Resistência a Múltiplos Medicamentos , Leucemia/tratamento farmacológico , Linfócitos/efeitos dos fármacos , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/fisiologia , Benzimidazóis/farmacologia , Linhagem Celular , DNA de Neoplasias/análise , Fluorometria , Humanos , Concentração de Íons de Hidrogênio , Leucemia/patologia , Mitocôndrias/efeitos dos fármacos , Oxazinas/farmacologia , Rodamina 123 , Rodaminas/farmacologiaRESUMO
The high incidence of hepatocellular carcinoma (HCC) in cirrhosis, where previous studies have indicated a severe reduction in several antioxidant vitamin factors, prompted us to compare plasma liposoluble vitamins with tocopherol content in healthy and neoplastic liver tissue in humans. This, with a view to a more positive preventive dietary approach, given the conflicting results obtained by liposoluble vitamin dietary supplementation in different malignancies. Eleven patients with cirrhosis, 18 patients affected by cirrhosis with HCC, and 10 patients with liver metastases (LM) from digestive tract adenocarcinomas were compared with controls who had undergone perlaparoscopic cholecistectomy. Plasma alpha- and beta-carotene, retinol and tocopherol, together with liver tocopherol, from both nonmalignant portions and malignant nodules of the same organ, were determined by high-performance liquid chromatography following a well-assessed technique. The results confirm a trend towards a reduction in circulating carotenoids and tocopherol in cirrhosis and in patients affected by cirrhosis with HCC. Tocopherol content in liver tissue is significantly decreased in cirrhosis (0.26 + 0.03 micromol/g prot., mean + SEM, P < .001) and in cirrhotic areas of the HCC group (0.31 + 0.02, P < .002), with respect to its content in liver specimens of healthy controls (0.46 + 0.03) and in healthy areas of the same organ in patients with LM (0.41 + 0.03). Tocopherol concentration is further reduced by 50% in malignant liver nodules of HCC, with respect to surrounding cirrhotic tissue, whereas in metastatic liver nodules from digestive neoplasms the tocopherol content is almost twice that of healthy surrounding areas. This unpredictable tocopherol behavior in liver specimens, of secondary as opposed to primary malignancies of the liver, affords further insight into the conflicting effects of liposoluble vitamins employed in the chemopreventive treatment of different malignant diseases, where hepatic tocopherol concentration show opposite trends: halved in primary HCC and doubled in LM of digestive adenocarcinomas, with respect to healthy controls.
Assuntos
Carcinoma Hepatocelular/química , Neoplasias Hepáticas/química , Fígado/química , Vitamina E/análise , Idoso , Carotenoides/sangue , Feminino , Humanos , Lipídeos/sangue , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , Vitamina A/sangue , Vitamina E/sangue , beta Caroteno/sangueRESUMO
Programmed cell death is a basic cellular process that has aroused much interest in recent years. Like immune cells, cultures of cerebellar granule neurons are very homogeneous and provide a unique opportunity for quantifying by flow cytometry one form of programmed cell death in the CNS, the apoptosis, and for studying its regulation by neurotrophic factors. We found that thyroid hormone promoted postmitotic survival by preventing the apoptosis of newly formed and early differentiated granule neurons in a dose-dependent manner. This regulation could be through the protein bcl-2, which is known to prevent cell death. This protein was present at all stages of granule neuron differentiation and appeared to be developmentally regulated. It was underexpressed in apoptotic granule neurons. The protein content of the cerebellum in hypothyroid rats was drastically reduced. In contrast, thyroid hormone caused a marked dose-dependent increase in the amounts of this protein in granule neuron cultures. The possibility that thyroid hormone may be directly or indirectly required to promote cell survival is discussed, in terms of the hormone control of the local delivery of neurotrophins, such as NGF and NT-3, as well as the expression of their low affinity receptors, gp75. We suggest that thyroid hormone has a permissive action on the developing CNS.
Assuntos
Apoptose/efeitos dos fármacos , Cerebelo/citologia , Cerebelo/crescimento & desenvolvimento , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Proteínas Tirosina Quinases/biossíntese , Proteínas Proto-Oncogênicas/biossíntese , Hormônios Tireóideos/farmacologia , Animais , Western Blotting , Diferenciação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Cerebelo/efeitos dos fármacos , DNA/metabolismo , Citometria de Fluxo , Técnica Direta de Fluorescência para Anticorpo , Hipotireoidismo/induzido quimicamente , Hipotireoidismo/metabolismo , Imuno-Histoquímica , Neurônios/ultraestrutura , Propiltiouracila , Proteínas Proto-Oncogênicas c-bcl-2 , Ratos , Ratos WistarRESUMO
Se ha llevado a cabo un estudio comparativo de los niveles de las vitaminasliposolubles y carotenoides naturales y las porfirinas plasmáticas en pacientes porfiricos y controles, completado con la determinación de otros parámetros bioquímicos que caracterizan la patología, con el objeto de evaluar el deterioro del sistema antioxidante liposoluble en las porfirias cutáneas y no cutáneas. Se recogieron muestras de sangre y orina de 68 pacientes porfíricos, 20 con porfiria cutánea tardia (PCT) sintomática, 15 con protoporfiria eritropoyética manifiesta, 15 con porfiria variegata (PV) en remisión,18 con porfiria aguda intermitente (PAI) latente. Se midió el contenido de retinol,tocoferol,alfa y beta carotenos, criptoxantina, zeoxantina y licopeno,índice de porfirinas plasmáticas (IPP),porfirinas totales (PTS) y la actividad de deaminasa en sangre,de aminolevúlico (ALA), porfobilinógeno (PBG)y porfirinas en orina. El IPP estuvo elevado en PCT=4,5 mas menos 1,1 (lambda=625 nm),enEPP= 2,53 mas menos 0,5 (lambda = 635 nm), en PV=4,3 mas menos 0,5 (lambda= 625nm) y normal(menor o igual 1,3 ,lambda = 618 nm) en PAI.El contenido de retinol estuvo dentro de los valores normales en todos los grupos (63,8-102,3 ug/dl). El tocoferol se encontró disminuido en PCT (970 mas menos12 ug/dl y PPe (668 mas menos 10 ug/dl) y dentro de los valores normales(1040 mas menos 1260 ug/dl) en PAI y PV, mientras quezeoxantina estuvo solo disminuída en PCT=18 mas menos 2 ug/dl y PPE =10,3 mas menos 1,3 ug/dl y normal (40,5 mas menos 1,3 ug/dl) en PAI y PV. Los valores de los carotenoides criptoxantina y licopeno fueron para PAI= 11,1 mas menos 2,1 ug/dl y 13,2 mas menos 2,1 ug/dl,PV=10,3 mas menos 1,1 ug/dl y 2,1 mas menos 0,9 ug/dl,PCT=9,1 mas menos 1,2 ug/dl y 9,2 mas menos 0,9 ug/dl y PPE= 11,3 mas menos 1,3 ug/dl y8,3 mas menos 1,1 ug/dl, menores que los respectivos valores normales 37,9 mas menos 1,2 ug/dl y 19,5 mas menos 0,9 ug/dl. Alfa y beta carotenos estuvieron reducidos en PV=1,0 mas menos 1,2 ug/dl y 4,8 mas menos 0,8 ug/dl, en PCT= 1,2 mas menos 0,6 ug/dl y 4,0 mas menos 0,8 ug/dl y PPE =2,5 mas menos 1,0 ug/dl y 8,5 mas menos 1,0 ug/dl( valores normales = 1,9 mas menos 0,3 ug/dl y 9,3 mas menos 0,5 ug/dl). Para el grupo de Pai sólo estuvo disminuido el contenido de beta carotenos ( 6,1 mas menos 1,2 ug/dl. Estos resultados muestran que el sistema liposoluble antioxidante tiene una capacidad reducida en pacientes porfíricos
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Vitaminas Lipossolúveis , Porfirias/sangue , Porfirias/urina , Dermatopatias , Porfirinas/sangueRESUMO
The need for accurate and noninvasive evaluation of liver iron stores prompted us to evaluate the reliability of high-field magnetic resonance imaging equipment in liver patients with low or moderate siderosis, given the poor results obtained using systems operating at low field strength in such cases. Twenty patients with sporadic porphyria cutanea tarda and 28 with comparable chronic liver diseases (chronic hepatitis or cirrhosis) and moderate siderosis were compared with 10 patients with idiopathic or secondary hemochromatosis and 10 healthy controls. Plasma iron profile, ferritin concentration and liver iron concentration, determined with atomic absorption spectroscopy, were matched with the magnetic resonance parameters-namely, transverse relaxation time and the signal intensity for a given proton amount, obtained with equipment operating at a field strength of 1.5 T. Hemochromatosis patients with mean liver iron concentrations of 550 mumol/gm dry wt (vs. 10 mumol of controls) exhibited an impressive reduction in the signal intensity with respect to the other three groups, and this reduction prevented any further comparison with the same porphyria cutanea tarda and chronic liver disease groups, whose liver iron level was twice that of the controls. The signal intensity remained almost unchanged in the latter groups, whereas the transverse relaxation time was significantly reduced. Moreover, correlation with liver iron was significantly inverse in the case of the transverse relaxation time (n = 17, r = 0.62, p = 0.008) and direct in the case of the transverse relaxation rate. The transverse relaxation time values returned to normal in five patients who had completed an iron-depletion program.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Hepatopatias/diagnóstico , Imageamento por Ressonância Magnética , Siderose/diagnóstico , Adulto , Idoso , Doença Crônica , Feminino , Ferritinas/sangue , Hepatite/metabolismo , Humanos , Ferro/sangue , Ferro/metabolismo , Fígado/metabolismo , Cirrose Hepática/metabolismo , Hepatopatias/metabolismo , Masculino , Pessoa de Meia-Idade , Siderose/metabolismo , Espectrofotometria AtômicaRESUMO
To gain insights at the molecular level into the expression of iron-regulated genes [transferrin (Tf), transferrin receptor (TfR), and ferritin H and L subunits] in human intestinal areas relevant to iron absorption, the steady-state levels of specific messenger RNAs (mRNAs) were analyzed in gastric and duodenal samples obtained from 6 normal subjects, or 10 patients with anemia, 14 patients with untreated iron overload, and 8 patients with various gastrointestinal disorders. No Tf mRNA was detected in human gastroduodenal tissue, confirming earlier findings in the rat. In normal subjects, although higher levels of ferritin H- and L-subunit mRNAs were consistently found in duodenal than in gastric samples, no differences in the content of TfR transcripts were detected. However, a dramatic increase in TfR mRNA levels was specifically found in duodenal samples from subjects with mild iron deficiency but severe anemia. This response of the TfR gene is presumably secondary to decreased cellular iron content due to its accelerated transfer into the bloodstream, as also indicated by the low levels of ferritin subunit mRNAs found in the same tissue samples, and is not linked to faster growth rate of mucosal cells because no changes in duodenal expression of histone, a growth-related gene, were detected. In patients with secondary iron overload, a down-regulation of duodenal TfR gene expression and a concomitant increase in ferritin mRNA content were documented. On the contrary, a lack of TfR gene down-regulation and an abnormally low accumulation of ferritin H- and L-subunit mRNAs were detected in the duodenums of subjects with idiopathic hemochromatosis. Whether these molecular abnormalities in idiopathic hemochromatosis are relevant to the metabolic defect(s) of the disease is presently unknown.
Assuntos
Duodeno/metabolismo , Ferritinas/biossíntese , Regulação da Expressão Gênica , Receptores da Transferrina/biossíntese , Transferrina/biossíntese , Adulto , Idoso , Anemia/metabolismo , Biópsia , Feminino , Hemocromatose/metabolismo , Histonas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Sondas Moleculares , RNA Mensageiro/análiseRESUMO
The role played by carotenoids, retinol and tocopherol in quencing oxidative cellular damage and combatting tumor growth is well documented, but little is known about their activity in human liver cirrhosis (LC), where oxidative damage and tumoral complications are common-place. We investigated 59 patients with LC of different etiology on admission to hospital and compared them with 32 healthy controls, matched for age and sex. Nutritional (cutaneous skinfolds, creatinine-height index) and serum parameters were determined; of these, alpha- and beta-carotene, cryptoxanthin, lycopene, retinol and alpha-tocopherol were detected by an high-performance liquid chromatographic (HPLC) technique, devised in our laboratory, which afforded an accurate and simultaneous resolution of all six compounds. The results point to a significant reduction in almost all the vitamin factors in LC, as well as in total serum lipids. In consequence, the ratio tocopherol/total serum lipids remains almost unchanged: 2.45 +/- 0.08 (m +/- se) in controls and 2.34 +/- 0.16 in patients. The effects of age, sex, nutritional habits, alcohol, malnutrition and the severity of the disease were also evaluated in relation to the vitamin-factor levels. It is suggested that the reduced levels observed in LC patients are due to a number of factors including portal hypertension and lymphatic circulation impairment, and it is concluded that thorough screening and improved diet are beneficial in the follow-up of LC.
Assuntos
Carotenoides/sangue , Cirrose Hepática/sangue , Vitamina A/sangue , Vitamina E/sangue , Cromatografia Líquida de Alta Pressão , Feminino , Humanos , Cirrose Hepática Alcoólica/sangue , MasculinoRESUMO
The aim of this paper is to evaluate invasive and non-invasive indices of iron store and compare the effectiveness of different ferrodepletive protocols in 150 patients with porphyria cutanea tarda (PCT). Iron removal was performed either by intensive phlebotomy (22 cases) or slow subcutaneous and high intravenous doses of desferrioxamine (18 and 5 cases, respectively), and several laboratory parameters were studied; among these, oligo-elements and urinary porphyrins (detected by HPLC) were taken into account before and after the treatments. Serum iron, transferrin saturation, ferritin (RIA) and nuclear magnetic resonance results were compared with invasive findings in order to detect the metal deposition in liver tissue (atomic absorption concentration, optic or electron-microscopic detection). Liver iron overload was observed in 95% of cases. Full normalization of the disease took place by all the treatments, even if it required slightly more time in the phlebotomy group. We may conclude that ferrodepletive treatments are highly effective in PCT and, considering the fact that siderosis and liver damage always accompany the disease, these treatments are proposed as first choice in such cases.
Assuntos
Desferroxamina/uso terapêutico , Ferro/metabolismo , Hepatopatias/terapia , Porfirias/terapia , Dermatopatias/terapia , Sangria , Cromatografia Líquida de Alta Pressão , Doença Crônica , Desferroxamina/administração & dosagem , Ferritinas/sangue , Humanos , Ferro/sangue , Hepatopatias/tratamento farmacológico , Hepatopatias/metabolismo , Microscopia Eletrônica , Porfirias/tratamento farmacológico , Porfirias/metabolismo , Dermatopatias/tratamento farmacológico , Dermatopatias/metabolismoRESUMO
To clarify the pathogenesis of hepatic iron toxicity, we investigated the effect of chronic dietary iron overload on the expression of several genes in rat liver. After 10 wk of iron treatment, when only minor histological features of liver damage were appreciable, the level of pro-alpha 2(I)-collagen mRNA was already higher than in control liver and increased further at 30 wk of treatment. Also, the relative amount of L ferritin subunit mRNA was enhanced early by iron load and was even more elevated at the latest time point considered, whereas neither H ferritin subunit nor transferrin mRNA levels were affected by iron treatment. In contrast, after chronic iron treatment, no variations were found in the steady-state level of mRNAs transcribed from liver-specific and preferentially expressed genes (albumin, alpha-fetoprotein, apolipoprotein A-1), growth-related genes (c-myc, c-Ha-ras and c-fos) and stress-induced genes (heat shock protein 70). These results suggest that chronic dietary iron overload in rats can specifically activate target genes in the liver (i.e., L ferritin and procollagen) in the absence of either histological signs of severe liver damage or alterations in differentiated liver functions.
Assuntos
Regulação da Expressão Gênica , Ferro/farmacologia , Fígado/fisiologia , Animais , Apolipoproteínas A/genética , Dieta , Feminino , Ferritinas/genética , Ferro/administração & dosagem , Fígado/metabolismo , Oncogenes , RNA Mensageiro/metabolismo , Ratos , Albumina Sérica/genética , Fatores de Tempo , Transferrina/genética , alfa-Fetoproteínas/genéticaRESUMO
Serum markers of hepatitis B virus (HBV) infection were determined in 82 patients with porphyria cutanea tarda (PCT). Pathogenetic factors (alcohol, thalassemia minor, drugs) and clinical and histologic findings of PCT were taken into account. The prevalence of HBV infection was very high (70.7%). Hepatitis B surface antigen (HBsAg) was positive in 14 patients (17%). Eight patients had HBV infection as the only documented acquired factor. The clinical picture and histologic findings were aggravated by HBV infection; primary hepatic carcinoma occurred in four patients with HBV infection. Liver siderosis was histologically documented in 82.6% of cases, serum ferritin was pathologically increased in 91%, confirming the role of iron overload in PCT. A correlation (p less than 0.02; chi-squared method) was found between increased serum ferritin levels and HBV infection, suggesting a possible relationship between liver siderosis and HBV clearance. HBV infection appears to be a relevant additional factor in the pathogenesis of PCT liver disease.