RESUMO
OBJECTIVE: To validate the proton density fat fraction (PDFF) obtained by the MRQuantif software from 2D chemical shift encoded MR (CSE-MR) data in comparison with the histological steatosis data. METHODS: This study, pooling data from 3 prospective studies spread over time between January 2007 and July 2020, analyzed 445 patients who underwent 2D CSE-MR and liver biopsy. MR derived liver iron concentration (MR-LIC) and PDFF was calculated using the MRQuantif software. The histological standard steatosis score (SS) served as reference. In order to get a value more comparable to PDFF, histomorphometry fat fraction (HFF) were centrally determined for 281 patients. Spearman correlation and the Bland and Altman method were used for comparison. RESULTS: Strong correlations were found between PDFF and SS (rs = 0.84, p < 0.001) or HFF (rs = 0.87, p < 0.001). Spearman's coefficients increased to 0.88 (n = 324) and 0.94 (n = 202) when selecting only the patients without liver iron overload. The Bland and Altman analysis between PDFF and HFF found a mean bias of 5.4% ± 5.7 [95% CI 4.7, 6.1]. The mean bias was 4.7% ± 3.7 [95% CI 4.2, 5.3] and 7.1% ± 8.8 [95% CI 5.2, 9.0] for the patients without and with liver iron overload, respectively. CONCLUSION: The PDFF obtained by MRQuantif from a 2D CSE-MR sequence is highly correlated with the steatosis score and very close to the fat fraction estimated by histomorphometry. Liver iron overload reduced the performance of steatosis quantification and joint quantification is recommended. This device-independent method can be particularly useful for multicenter studies. CLINICAL RELEVANCE STATEMENT: The quantification of liver steatosis using a vendor-neutral 2D chemical-shift MR sequence, processed by MRQuantif, is well correlated to steatosis score and histomorphometric fat fraction obtained from biopsy, whatever the magnetic field and the MR device used. KEY POINTS: ⢠The PDFF measured by MRQuantif from 2D CSE-MR sequence data is highly correlated to hepatic steatosis. ⢠Steatosis quantification performance is reduced in case of significant hepatic iron overload. ⢠This vendor-neutral method may allow consistent estimation of PDFF in multicenter studies.
Assuntos
Fígado Gorduroso , Sobrecarga de Ferro , Hepatopatia Gordurosa não Alcoólica , Humanos , Prótons , Estudos Prospectivos , Fígado/diagnóstico por imagem , Fígado/patologia , Imageamento por Ressonância Magnética/métodos , Fígado Gorduroso/diagnóstico por imagem , Fígado Gorduroso/patologia , Sobrecarga de Ferro/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/diagnóstico por imagem , Hepatopatia Gordurosa não Alcoólica/patologiaRESUMO
The quality of pathologic assessment of rectal cancer specimens is crucial for treatment efficiency and survival. The Royal College of Pathologists (RCP) recommends evaluating the quality of the pathology report in routine practice using three quality indicators (QIs): the number of lymph nodes (LNs) analyzed (≥ 12), the rate of venous invasion (VI ≥ 30%), and peritoneal involvement (pT4a ≥ 10%). In this study, we evaluated the three QIs of the French national pathology reports and compared them with British guidelines and assessed the influence of neoadjuvant radiochemotherapy on QIs. From January 1 to December 31, 2016, all pathology reports for rectal adenocarcinoma were collected from French departments. Neoadjuvant radiochemotherapy included long-course radiotherapy with concomitant 5-FU-based chemotherapy. A total of 983 rectal cancer pathology reports were evaluated. A median of 15 LNs were analyzed and 81% of centers had ≥ 12 LNs. The rate of VI was 30% and 41% of centers had ≥ 30% VI. The rate of pT4a was 4% and 18% of centers reported ≥ 10% pT4a. None of the centers reached the threshold for the three QIs. All three QIs were lower after radiochemotherapy compared to surgery alone. In conclusion, in French routine practice, the values of two of the three QIs (LNs analyzed and VI) were globally in line with RCP guidelines. However, the rate of pT4a was very low, particularly after radiochemotherapy, suggesting its low value in rectal cancer.
Assuntos
Linfonodos/patologia , Metástase Linfática/patologia , Neoplasias Retais/patologia , Neoplasias Retais/terapia , Idoso , Quimiorradioterapia/métodos , Feminino , França , Humanos , Excisão de Linfonodo/métodos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante/métodos , Estadiamento de Neoplasias , Radioterapia Adjuvante/métodos , Resultado do TratamentoRESUMO
PURPOSE: To evaluate the performance and limitations of the signal intensity ratio method for quantifying liver iron overload at 3 T. METHODS: Institutional review board approval and written informed consent from all participants were obtained. One hundred and five patients were included prospectively. All patients underwent a liver biopsy with biochemical assessment of hepatic iron concentration and a 3 T MRI scan with 5 breath-hold single-echo gradient-echo sequences. Linear correlation between liver-to-muscle signal intensity ratio and liver iron concentration was calculated. The algorithm for calculating magnetic resonance hepatic iron concentration was adapted from the method described by Gandon et al. with echo times divided by 2. Sensitivity and specificity were calculated. RESULTS: Five patients were excluded (coil selection failure or missing sequence) and 100 patients were analyzed, 64 men and 36 women, 52 ± 13.3 years old, with a biochemical hepatic iron concentration range of 0-630 µmol/g. Linear correlation between biochemical hepatic iron concentration and MR-hepatic iron concentration was excellent with a correlation coefficient = 0.96, p < 0.0001. Sensitivity and specificity were, respectively, 83% (0.70-0.92) and 96% (0.85-0.99), with a pathological threshold of 36 µmol/g. CONCLUSION: Signal intensity ratio method for quantifying liver iron overload can be used at 3 T with echo times divided by 2.
Assuntos
Sobrecarga de Ferro/diagnóstico por imagem , Hepatopatias/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Algoritmos , Biópsia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e EspecificidadeAssuntos
Dissecação da Artéria Carótida Interna/complicações , Dor Lombar/diagnóstico , Dor Lombar/etiologia , Dissecção Aórtica/complicações , Dissecção Aórtica/diagnóstico por imagem , Dissecação da Artéria Carótida Interna/diagnóstico por imagem , Humanos , Dor Lombar/diagnóstico por imagem , Vértebras Lombares/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Radiografia Abdominal , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Disulone (dapsone + iron oxalate) is a sulfone used in the treatment of numerous skin diseases. We report two cases of hepatosiderosis secondary to long-term administration of Disulone. PATIENTS AND METHODS: Case n degrees 1. A 51-year-old man was treated with Disulone for a neutrophilic skin disease. After 17 years of treatment, elevated serum ferritin and free iron with hemolysis were found. Liver biopsy confirmed hepatosiderosis. A diagnosis of genetic hemochromatosis was ruled out by the absence of C282Y mutation of the HFE gene. Case n degrees 2. A 52-year-old man receiving Disulone for dermatitis herpetiformis for 25 years presented elevated serum ferritin and free iron with hemolysis. Hepatic iron overload was confirmed by liver biopsy. The absence of C282Y mutation (HFE gene) ruled out a diagnosis of genetic hemochromatosis. DISCUSSION: In our two cases, hepatosiderosis was noted after long-term administration of Disulone. This complication has been reported only rarely. In murine models, a relationship was found between prolonged administration of dapsone and hepatic iron overload as revealed by hemolysis. Although it is difficult to extrapolate this relationship to humans with any certainty, our patients had also chronic hemolysis and iron overload secondary to administration of Disulone. Moreover in France, dapsone is marketed in combination with iron oxalate, with the attendant risk of iron overload. These cases raise the question of the need for serum ferritin analysis during Disulone therapy.
Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas , Dapsona/efeitos adversos , Fármacos Dermatológicos/efeitos adversos , Hemossiderose/induzido quimicamente , Dermatite Herpetiforme/tratamento farmacológico , Ferritinas/sangue , Hemólise/fisiologia , Humanos , Ferro/sangue , Masculino , Pessoa de Meia-Idade , Neutrófilos , Dermatopatias/tratamento farmacológicoRESUMO
BACKGROUND: Acute rejection is still a common complication of hepatic transplantation. The diagnosis, based on the histological examination of the graft, may be difficult to confirm in the setting of combined hepatitis C virus infection. The presence of C4d in the portal capillaries could facilitate differentiation between acute rejection and relapsed hepatitis C. The deposit of C4d provides evidence of activation of humoral immunity. To attempt to confirm this hypothesis, we searched for the presence of C4d in posttransplant hepatic biopsies. METHODS: Thirty-six biopsies from 34 patients were analyzed retrospectively. The samples had been requested for one of the following reasons: suspected rejection, relapsed hepatitis C infection, or systematic check-up 1 year after the transplant. RESULTS: C4d expression was common in biopsies classified as acute rejection (33%) and chronic rejection (100%). C4d was never detected in the event of recurrent hepatitis C infection without rejection. CONCLUSION: These results, which are comparable to recently published data, give credence to the theory that C4d could be used as a marker for rejection following hepatic transplantation.
Assuntos
Complemento C4b/análise , Rejeição de Enxerto/diagnóstico , Transplante de Fígado/imunologia , Fragmentos de Peptídeos/análise , Doença Aguda , Biomarcadores/sangue , Biópsia , Doença Crônica , Rejeição de Enxerto/sangue , Hepatite C/complicações , Humanos , Cirrose Hepática/sangue , Cirrose Hepática/virologia , Transplante de Fígado/patologiaRESUMO
Potential antiviral properties of cyclosporine against hepatitis C virus have been highlighted in several publications. Therefore, we investigated the effect of a switch from tacrolimus to cyclosporine in a liver transplant recipient with recurrent hepatitis C who did not respond to antiviral therapy. The patient received a liver transplant for hepatitis C cirrhosis. Initial immunosuppressive treatment was based on tacrolimus. Because of viral activity, a combined therapy was initiated 20 months later including interferon and ribavirine. Then, due to a lack of virological and biochemical response, tacrolimus was replaced by cyclosporine (Neoral), while maintaining the same antiviral therapy. Decreases in the viral load and transaminases levels were observed.
Assuntos
Ciclosporina/uso terapêutico , Hepacivirus/isolamento & purificação , Transplante de Fígado/fisiologia , RNA Viral/sangue , Tacrolimo/uso terapêutico , Adolescente , Humanos , Imunossupressores/uso terapêutico , Testes de Função Hepática , Transplante de Fígado/imunologia , Masculino , Carga ViralRESUMO
Infrared fingerprints of molecules in biology contain much information on cells metabolism allowing one to distinguish between healthy and altered tissues. Here, to collect infrared signatures, we used evanescent wave spectroscopy based on an original infrared transmitting tapered glass fiber. A strict control of the fiber diameter in the tapered sensing zone allows high sensitivity and wide spectral range exploration from 800 to 3000 cm(-1). Then, merely in depositing the mouse liver biopsies on the fiber, this device has enable us to differentiate between tumorous and healthy tissues.
Assuntos
Tecnologia de Fibra Óptica , Raios Infravermelhos , Fígado/metabolismo , Análise Espectral , Animais , Testes Diagnósticos de Rotina , Camundongos , Fibras Ópticas , Sensibilidade e Especificidade , Análise Espectral/instrumentaçãoRESUMO
The development of cancer on the ileal graft after augmentation ileocystoplasty for benign bladder disease is a little known complication. The authors report a case of squamous cell carcinoma in the ileal bladder occurring 37 years after augmentation ileocystoplasty for tuberculous bladder, in a 68-year old patient. Carcinomatous degeneration is usually occurs more than ten years after cystoplasty. Patients treated by this operation must be submitted to annual cystoscopy combined with guided biopsies at the slightest doubt. This surveillance should be started between the 5th and the 10th postoperative year.
Assuntos
Tuberculose Urogenital/cirurgia , Doenças da Bexiga Urinária/cirurgia , Neoplasias da Bexiga Urinária/etiologia , Derivação Urinária/efeitos adversos , Idoso , Transformação Celular Neoplásica , Humanos , Íleo/patologia , Íleo/cirurgia , MasculinoRESUMO
Renal cell carcinoma (RCC) is known to have a wide variation in clinical outcome despite the use of conventional prognostic factors, such as staging or grading. A better knowledge of the biologic aggressiveness of RCC could facilitate the selection of patients at high risk of tumor progression. The aim of this study was to determine if use of measurements of vascular density, cell proliferation, and cell adhesion could better predict the biologic behavior of RCC. We immunohistochemically analyzed CD34, Ki-67, and CD44H expression on formalin-fixed, paraffin-embedded tissues from 73 RCCs for quantifying microvessel density (MVD), Ki-67 labeling index (LI), and CD44H LI, respectively. Univariate cancer-specific survival analysis showed that tumor stage (P < .01), tumor size (P < .001), nuclear grade (P < .01), metastasis (P < .001), MVD (P < .03), Ki-67 LI (P < .001), and CD44H LI (P < .0001) were predictors of tumor-related death. There was a statistical correlation between CD44H LI and both Ki-67 LI (r' = .3) and MVD (r' = -44). Ki-67 LI (P < .04) and CD44H LI (P < .02), as well as metastasis (P < .008), emerged as independent predictors of cancer-specific survival in multivariate analysis in patients with metastases (P < .04 and P < .02, respectively) and in patients without metastases (P < .006 and P < .00001, respectively). Our study suggests that vascular density, cell proliferation, and cell adhesion represent a complex tumor-host interaction that may favor progression of RCC. Cell proliferation and CD44H expression appear to be powerful markers to identify patients with an adverse prognosis.
Assuntos
Carcinoma de Células Renais/diagnóstico , Carcinoma de Células Renais/metabolismo , Moléculas de Adesão Celular/metabolismo , Receptores de Hialuronatos/metabolismo , Neoplasias Renais/diagnóstico , Neoplasias Renais/metabolismo , Neovascularização Patológica , Adulto , Idoso , Antígenos CD34/imunologia , Antígenos CD34/metabolismo , Biomarcadores Tumorais/análise , Capilares/patologia , Carcinoma de Células Renais/irrigação sanguínea , Carcinoma de Células Renais/mortalidade , Moléculas de Adesão Celular/imunologia , Divisão Celular , Progressão da Doença , Feminino , Humanos , Receptores de Hialuronatos/imunologia , Imuno-Histoquímica , Antígeno Ki-67/imunologia , Antígeno Ki-67/metabolismo , Neoplasias Renais/irrigação sanguínea , Neoplasias Renais/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Análise de SobrevidaRESUMO
We examined the cellular distribution of glutathione transferase A4 (GSTA4) in various human tissues by indirect immunoperoxidase using a specific polyclonal antibody raised in rabbit. This enzyme was localized in hepatocytes, bile duct cells, and vascular endothelial cells in liver, upper layers of keratinocytes and sebaceous and sweat glands in skin, proximal convoluted tubules in kidney, epithelial cells of mucosa and muscle cells in colon, muscle cells in heart, and neurons in brain. Staining was increased in pathological situations such as cirrhosis, UV-irradiated skin, and myocardial infarction and was strongly decreased in hepatocellular carcinoma. These results strongly support the view of a close correlation between cellular GSTA4 localization and the formation of reactive oxygen species in the tissues investigated.
Assuntos
Anticorpos , Glutationa Transferase/metabolismo , Animais , Especificidade de Anticorpos , Western Blotting , Glutationa Transferase/imunologia , Humanos , Imuno-Histoquímica , Camundongos , Especificidade de Órgãos , Testes de Precipitina , Coelhos , Proteínas Recombinantes/imunologiaRESUMO
The aim of the present study was to describe histologic features of the liver in insulin resistance-associated hepatic iron overload (IR-HIO), defined as the association of metabolic disorders and hepatic iron overload. We included 139 patients in the study on the basis of one or more metabolic disorders and liver iron overload unrelated to usual causes. Liver biopsy specimens were reviewed, and histologic data were compared with those of a previously published, well-defined population with genetic hemochromatosis. Iron overload was characterized by a mixed pattern with iron deposits in hepatocytes and sinusoidal cells. Steatosis was present in 59.7% of patients with inflammation in 32.4% of cases. Periportal fibrosis was found in 67.4% of patients. These patients were older, had higher sinusoidal iron scores, and had a higher prevalence of steatosis and inflammation than patients without fibrosis. Iron overload in IR-HIO was histologically different from that in genetic hemochromatosis.
Assuntos
Resistência à Insulina , Sobrecarga de Ferro/patologia , Fígado/patologia , Adulto , Idoso , Biópsia , Índice de Massa Corporal , Complicações do Diabetes , Fígado Gorduroso/complicações , Fígado Gorduroso/patologia , Feminino , Intolerância à Glucose/complicações , Humanos , Ferro/análise , Sobrecarga de Ferro/complicações , Fígado/química , Cirrose Hepática/complicações , Cirrose Hepática/patologia , Masculino , Pessoa de Meia-IdadeRESUMO
We report a case of multiple aseptic splenic abscesses occurring in a woman with Crohn's disease for three years. All microbiological samples were negative. The diagnosis was suspected on abdominal echography and CT scan and confirmed on histologic examination of the splenectomy specimen. The evolution was marked by recurrence of fever and inflammatory syndrome, associated to transitory morphological abnormalities of the accessory spleen. Aseptic splenic abscesses recurrence was suspected. This case allows us to consider aseptic splenic abscesses as an extra-intestinal manifestation and not as a splenic localisation of Crohn's disease.
Assuntos
Abscesso/etiologia , Doença de Crohn/complicações , Esplenopatias/etiologia , Abscesso/diagnóstico , Adulto , Feminino , Humanos , Recidiva , Baço/patologia , Esplenectomia , Esplenopatias/diagnóstico , Esplenopatias/cirurgia , Tomografia Computadorizada por Raios X , UltrassonografiaRESUMO
Matrix metalloproteinase-2 (MMP2) is a key enzyme in the process of extracellular matrix remodeling involved in tumor invasion and metastasis. The activation of MMP2 involves interplay with the membrane type-matrix metalloproteinase-1 (MT1-MMP) and the tissue inhibitor of metalloproteinase-2 (TIMP2). In vitro, activated hepatic stellate cells are a main source of MMP2 and collagen I induces MMP2 activation. The steady-state mRNA levels of MMP2, MT1-MMP, TIMP2, collagen I, collagen IV, and laminin gamma1 were compared with MMP2 activity in 55 hepatocellular carcinomas, 47 matching nontumor biopsies and 19 histologically normal livers. In hepatocellular carcinomas, increased collagen I mRNA levels were strongly associated with those of MMP2 (Spearman R =.74, P <.001), MT1-MMP (R =.65, P <.001) and TIMP2 (R = 0.61, P <.001). MMP2 activity was correlated with the mRNA expression of collagen I (R =.45 P <.01), collagen IV (R =.40, P <.01) and laminin gamma1 (R =.33, P <.05). Unlike collagen IV and laminin gamma1 mRNAs, MMP2, MT1-MMP, TIMP2, collagen I mRNA levels were increased in nonencapsulated compared with encapsulated tumors (P <.05). In addition, MMP2 activity was fourfold higher (P <.01) in tumors arising in cirrhotic livers than in those arising in noncirrhotic livers. Moreover, tumor recurrence was associated with 4.6- and 2.8-fold (P <.05) higher collagen I and MMP2 mRNA levels, respectively, in hepatocellular carcinomas arising in cirrhotic livers. Thus, a high extracellular matrix remodeling favors tumor progression in hepatocellular carcinomas.
Assuntos
Carcinoma Hepatocelular/patologia , Matriz Extracelular/metabolismo , Neoplasias Hepáticas/patologia , Idoso , Carcinoma Hepatocelular/química , Carcinoma Hepatocelular/enzimologia , Colágeno/genética , Colágeno/farmacologia , Ativação Enzimática/efeitos dos fármacos , Feminino , Humanos , Laminina/genética , Neoplasias Hepáticas/química , Neoplasias Hepáticas/enzimologia , Masculino , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinases da Matriz Associadas à Membrana , Metaloendopeptidases/genética , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , RNA Mensageiro/análise , Inibidor Tecidual de Metaloproteinase-2/genéticaRESUMO
The high prevalence of hepatocellular carcinoma (HCC) in genetic hemochromatosis (GH) and the association between increased body iron stores and occurrence of HCC in subjects with iron overload unrelated to GH, and the experimental evidence of a co-carcinogenic role of iron strongly support that iron is involved in the development of HCC.
Assuntos
Carcinoma Hepatocelular/etiologia , Sobrecarga de Ferro/complicações , Ferro/efeitos adversos , Neoplasias Hepáticas/etiologia , Animais , Hemocromatose/complicações , HumanosRESUMO
Endostatin is an endogenous inhibitor of angiogenesis and tumor growth in mice, which may be generated by proteolytic cleavage of collagen XVIII. In normal tissues, 2 variants of the endostatin precursor, namely the SHORT and LONG forms, regulate tissue specificity. We analyzed 53 human liver biopsies (18 hepatocellular carcinomas, 16 metastases of colorectal cancer, 3 cholangiocarcinomas, and 16 controls) by RNA dot blots, double-labeling immunohistochemistry, and in situ hybridization, using common and variant-specific probes. Tumor hepatocytes expressed the LONG form, whereas cholangiocarcinoma cells expressed the SHORT form, which was deposited in tumor basement membranes. Metastatic colorectal carcinoma cells did not express collagen XVIII. In the stromal compartment of primary and metastatic cancers, myofibroblasts and vascular endothelial cells expressed the SHORT form. Both basement membrane components, collagen IV and the SHORT collagen XVIII form, were codistributed and their mRNA levels strongly correlated (R =.75, P <.001). In addition, freshly isolated human hepatocytes expressed the LONG form and culture-activated stellate cells the SHORT form. Moreover, the full-length LONG form is a plasma protein. Thus, the LONG form is a hepatocyte-specific variant, and the SHORT form is a major component of the tumor extracellular matrix in primary and metastatic liver cancers. In the clinical context, the global expression of the endogenous endostatin precursor, collagen XVIII, in liver cancer results from the combined expression profiles of tumor cells, stromal cells, and nontumor hepatocytes at the advancing edge of the tumor, particular to each type of cancer.
Assuntos
Colágeno/biossíntese , Hepatócitos/metabolismo , Neoplasias Hepáticas/metabolismo , Fragmentos de Peptídeos/biossíntese , Membrana Basal/fisiologia , Neoplasias dos Ductos Biliares/metabolismo , Proteínas Sanguíneas/biossíntese , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/fisiopatologia , Células Cultivadas , Colangiocarcinoma/metabolismo , Colágeno/química , Colágeno Tipo XVIII , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Endostatinas , Fibroblastos/metabolismo , Humanos , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/fisiopatologia , Neoplasias Hepáticas/secundário , Músculo Liso/metabolismo , Músculo Liso/patologia , Fragmentos de Peptídeos/química , Células Estromais/metabolismoRESUMO
In humans, hepatic iron overload can lead to hepatocellular carcinoma development. Iron related dysregulation of hepatic genes could play a role in this phenomenon. We previously found that the carbonyl-iron overloaded mouse was a useful model to study the mechanisms involved in the development of hepatic lesions related to iron excess. The aim of the present study was to identify hepatic genes overexpressed in conditions of iron overload by using this model. A suppressive subtractive hybridization was performed between hepatic mRNAs extracted from control and 3% carbonyl-iron overloaded mice during 8 months. This methodology allowed us to identify stearoyl coenzyme A desaturase 1 (SCD1) mRNA overexpression in the liver of iron loaded mice. The corresponding enzymatic activity was also found to be significantly increased. In addition, we demonstrated that both SCD1 mRNA expression and activity were increased in another iron overload model in mice obtained by a single iron-dextran subcutaneous injection. Moreover, we found, in both models, that SCD1 mRNA was not only influenced by the quantity of iron in the liver but also by the duration of iron overload since SCD1 mRNA upregulation was not detected in earlier stages of iron overload. In addition, we found that cellular repartition likely influenced SCD1 mRNA expression. In conclusion, we demonstrated that iron excess in the liver induced both the expression of SCD1 mRNA and its corresponding enzymatic activity. The level and duration of iron overload, as well as cellular repartition of iron excess in the liver likely play a role in this induction. The fact that the expression and activity of SCD1, an enzyme adding a double bound into saturated fatty acids, are induced in two models of iron overload in mice leads to the conclusion that iron excess in the liver may enhance the biosynthesis of unsaturated fatty acids.
Assuntos
Sobrecarga de Ferro/metabolismo , Fígado/metabolismo , Estearoil-CoA Dessaturase/metabolismo , Animais , Modelos Animais de Doenças , Ativação Enzimática , Regulação da Expressão Gênica/efeitos dos fármacos , Compostos Carbonílicos de Ferro , Complexo Ferro-Dextran , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Compostos Organometálicos , RNA Mensageiro/análise , Estearoil-CoA Dessaturase/biossíntese , Estearoil-CoA Dessaturase/genética , Regulação para CimaRESUMO
Endostatin inhibits angiogenesis and tumor growth in mice. The role of its endogenous precursor collagen XVIII in human cancer is unknown. In normal tissues, two variants of collagen XVIII, namely, the short and long forms regulate tissue specificity, the long form being almost exclusively expressed by hepatocytes in the liver. We analyzed RNA arrays from 57 hepatocellular carcinomas (HCCs) with common and variant-specific probes and investigated the relationships between collagen XVIII expression and angiogenesis by measuring the CD34-positive microvessel density. Low collagen XVIII expression by tumor hepatocytes was associated with large tumor size (r, -0.63; P < 0.001) and replacement of trabeculae with pseudoglandular-solid architecture (chi2, 28; P < 0.001), which indicate tumor progression. Tumors expressing the highest collagen XVIII levels were smaller and had lower microvessel density (P = 0.01) than those expressing moderate levels; and HCCs with the lowest collagen XVIII levels approached a plateau of microvessel density, which indicated that a decrease in collagen XVIII expression is associated with angiogenesis in primary liver cancer. HCCs recurring within 2 years of resection showed 2.2-fold lower collagen XVIII mRNA than nonrecurring ones (P = 0.02). The findings relied on the hepatocyte-specific long form. Thus, the endogenous expression of the endostatin precursor decreases along with tumor progression in HCCs.
Assuntos
Carcinoma Hepatocelular/metabolismo , Colágeno/biossíntese , Neoplasias Hepáticas/metabolismo , Fragmentos de Peptídeos/biossíntese , Processamento Alternativo , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/patologia , Colágeno Tipo XVIII , Progressão da Doença , Endostatinas , Feminino , Humanos , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/patologia , Masculino , Neovascularização Patológica/metabolismo , RNA Mensageiro/metabolismoRESUMO
Considering that the development of hepatic lesions related to iron overload diseases might be a result of abnormally expressed hepatic genes, we searched for new genes up-regulated under the condition of iron excess. By suppressive subtractive hybridization performed between livers from carbonyl iron-overloaded and control mice, we isolated a 225-base pair cDNA. By Northern blot analysis, the corresponding mRNA was confirmed to be overexpressed in livers of experimentally (carbonyl iron and iron-dextran-treated mice) and spontaneously (beta(2)-microglobulin knockout mice) iron-overloaded mice. In addition, beta(2)-microglobulin knockout mice fed with a low iron content diet exhibited a decrease of hepatic mRNA expression. The murine full-length cDNA was isolated and was found to encode an 83-amino acid protein presenting a strong homology in its C-terminal region to the human antimicrobial peptide hepcidin. In addition, we cloned the corresponding rat and human orthologue cDNAs. Both mouse and human genes named HEPC are constituted of 3 exons and 2 introns and are located on chromosome 7 and 19, respectively, in close proximity to USF2 gene. In mouse and human, HEPC mRNA was predominantly expressed in the liver. During both in vivo and in vitro studies, HEPC mRNA expression was enhanced in mouse hepatocytes under the effect of lipopolysaccharide. Finally, to analyze the intracellular localization of the predicted protein, we used the green fluorescent protein chimera expression vectors. The murine green fluorescent protein-prohepcidin protein was exclusively localized in the nucleus. When the putative nuclear localization signal was deleted, the resulting protein was addressed to the cytoplasm. Taken together, our data strongly suggest that the product of the new liver-specific gene HEPC might play a specific role during iron overload and exhibit additional functions distinct from its antimicrobial activity.
Assuntos
Anti-Infecciosos , Peptídeos Catiônicos Antimicrobianos/genética , Regulação da Expressão Gênica , Sobrecarga de Ferro/metabolismo , Fígado/metabolismo , Animais , Sequência de Bases , Clonagem Molecular , DNA Complementar/isolamento & purificação , Regulação da Expressão Gênica/efeitos dos fármacos , Hepcidinas , Ferro/farmacologia , Lipopolissacarídeos/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Dados de Sequência Molecular , Especificidade de Órgãos , Ratos , Ratos Sprague-DawleyRESUMO
AIMS: This prospective randomized trial was carried out in order to determine whether the long-term administration of ursodeoxycholic acid after discontinuation of interferon had any beneficial effect on the clinical course of hepatitis C virus infection. METHODS: Enrolled in the study were 203 patients with chronic active hepatitis C. They were all given: interferon alpha-2a (3 MU subcutaneously thrice a week) and ursodeoxycholic acid (10 mg/kg/day) for 9 months. At month 9, biochemical responders only were randomized into ursodeoxycholic acid treatment or placebo for 12 additional months (double blind study). RESULTS: At the end of interferon therapy, 71 patients (37%) were virological responders and 107 (56%) patients were biochemical responders and were randomized: 54 into the ursodeoxycholic acid group and 53 into the placebo group. Sustained response was evaluated 12 months after withdrawal of interferon. Sustained biochemical and virological responses were, respectively, 30% and 22% in the ursodeoxycholic acid group and 46% and 32% in the placebo group, which did not significantly differ. Histological evolution of fibrosis and necrotic inflammatory activity were similar in the two groups. CONCLUSION: Continuation of ursodeoxycholic acid therapy after withdrawal of interferon in patients with end-of-treatment response did not result in any significant improvement either in the maintenance of response to interferon or in liver histology.