Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 41
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Future Oncol ; 14(1): 65-75, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29235888

RESUMO

AIM: To validate the American Joint Committee on Cancer (AJCC) clinical staging system for esophageal cancer using Surveillance, Epidemiology and End Results database. METHODS: Cancer-specific survival analyses for clinically-staged patients with esophageal cancer according to both seventh and eighth editions were conducted through Kaplan-Meier analysis. RESULTS: For cancer-specific survival according to both seventh and eighth clinical systems, p-values for pairwise comparisons were nonsignificant in many comparisons. C-index for adenocarcinoma was: 0.671 according to the seventh AJCC and 0.671 according to the clinical eighth AJCC. C-index for squamous cell carcinoma according to the seventh AJCC was: 0.634 and 0.643 according to clinical eighth AJCC. CONCLUSION: Minimal improvement was achieved by the eighth clinical AJCC staging system for esophageal cancer.


Assuntos
Adenocarcinoma/patologia , Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/patologia , Prognóstico , Adenocarcinoma/epidemiologia , Adulto , Idoso , Carcinoma de Células Escamosas/epidemiologia , Intervalo Livre de Doença , Neoplasias Esofágicas/epidemiologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias/classificação , Programa de SEER , Estados Unidos
2.
Future Oncol ; 14(4): 379-389, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29318911

RESUMO

AIM: To evaluate the predictive value for cancer-specific survival of the models of the American Joint Committee on Cancer (AJCC) stage, NIH and Armed Forces Institute of Pathology (AFIP) among patients with gastrointestinal stromal tumors (GISTs). METHODS: Surveillance, Epidemiology and End Results database (2010-2014) was accessed. Overall survival analysis and adjusted cancer-specific Cox regression hazard was calculated. RESULTS: For gastric GISTs, concordance-index according to AJCC was 0.834; according to NIH was 0.833; according to AFIP was 0.836. Concordance-index for nongastric GISTs according to AJCC was 0.800, according to NIH was 0.801 and according to AFIP was 0.799. CONCLUSION: The performance of the three models is comparable with regards to cancer-specific survival prediction.


Assuntos
Tumores do Estroma Gastrointestinal/epidemiologia , Recidiva Local de Neoplasia/epidemiologia , Prognóstico , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Tumores do Estroma Gastrointestinal/patologia , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Estadiamento de Neoplasias , Programa de SEER , Análise de Sobrevida
4.
J Pathol ; 231(4): 532-42, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23749468

RESUMO

The liver is the central regulator of iron metabolism and accordingly, chronic liver diseases often lead to systemic iron overload due to diminished expression of the iron-regulatory hormone hepcidin. To study the largely unknown regulation of iron metabolism in the context of hepatic disease, we used two established models of chronic liver injury, ie repeated carbon tetrachloride (CCl(4)) or thioacetamide (TAA) injections. To determine the impact of CCAAT/enhancer-binding protein (C/EBP)-homologous protein (CHOP) on hepcidin production, the effect of a single TAA injection was determined in wild-type and CHOP knockout mice. Furthermore, CHOP and hepcidin expression was assessed in control subjects and patients with alcoholic liver disease. Both chronic injury models developed a distinct iron overload in macrophages. TAA-, but not CCl(4) - injected mice displayed additional iron accumulation in hepatocytes, resulting in a significant hepatic and systemic iron overload which was due to suppressed hepcidin levels. C/EBPα signalling, a known hepcidin inducer, was markedly inhibited in TAA mice, due to lower C/EBPα levels and overexpression of CHOP, a C/EBPα inhibitor. A single TAA injection resulted in a long-lasting (> 6 days) suppression of hepcidin levels and CHOP knockouts (compared to wild-types) displayed significantly attenuated hepcidin down-regulation in response to acute TAA administration. CHOP mRNA levels increased 5-fold in alcoholic liver disease patients versus controls (p < 0.005) and negatively correlated with hepcidin expression. Our results establish CHOP as an important regulator of hepatic hepcidin expression in chronic liver disease. The differences in iron metabolism between the two widely used fibrosis models likely reflect the differential regulation of hepcidin expression in human liver disease.


Assuntos
Hepcidinas/biossíntese , Sobrecarga de Ferro/etiologia , Cirrose Hepática Experimental/complicações , Hepatopatias Alcoólicas/complicações , Fator de Transcrição CHOP/fisiologia , Animais , Proteína alfa Estimuladora de Ligação a CCAAT/biossíntese , Proteína alfa Estimuladora de Ligação a CCAAT/genética , Tetracloreto de Carbono , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Inativação de Genes , Hepcidinas/genética , Humanos , Ferro/metabolismo , Sobrecarga de Ferro/metabolismo , Fígado/metabolismo , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/metabolismo , Hepatopatias Alcoólicas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , RNA Mensageiro/genética , Transdução de Sinais/efeitos dos fármacos , Tioacetamida , Fator de Transcrição CHOP/biossíntese , Fator de Transcrição CHOP/deficiência , Fator de Transcrição CHOP/genética
5.
Gut ; 61(2): 193-201, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21757452

RESUMO

BACKGROUNDS AND AIMS: Hepcidin is an antimicrobial peptide and the central regulator of iron metabolism. Given that hepcidin was shown to be expressed in a variety of extrahepatic tissues and that stomach plays a role in iron absorption and in defence against infections, this study analysed the importance of hepcidin in the stomach. METHODS: Expression and localisation of gastric hepcidin was studied by quantitative RT-PCR, western blot, immunofluorescence and in situ hybridisation. Regulation of gastric hepcidin expression was analysed both in vitro and in vivo. Hepcidin wild-type (WT) and knockout (KO) animals were used to determine the impact of hepcidin on gastric bacterial overgrowth as well as gastric acid secretion. RESULTS: Hepcidin was abundantly expressed in the gastric fundus and corpus of all tested species. Treatment of AGS cells with ferric nitrilotriacetate solution downregulated hepcidin expression levels, while desferroxamine, interleukin 6 and Helicobacter pylori infection upregulated it. In humans, gastric hepcidin expression was elevated during H pylori infection and normalised after successful eradication. Gastric hepcidin is localised in parietal cells that are indispensable for gastric acid secretion. Comparisons of WT and hepcidin KO mice revealed that acid secretion in hepcidin-deficient mice is markedly reduced and is associated with gastric bacterial overgrowth, expression changes in multiple factors involved in acid secretion (Atp4a, Cck2r,Gas, Sst and Sst2r) and with reduced circulating gastrin levels. In WT mice, pantoprazole activated and histamine downregulated hepcidin expression levels. CONCLUSIONS: Hepcidin is a product of parietal cells regulating gastric acid production and may contribute to development of gastric ulcers under stress conditions.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Mucosa Gástrica/metabolismo , Infecções por Helicobacter/metabolismo , Helicobacter pylori , Animais , Western Blotting , Linhagem Celular , Feminino , Imunofluorescência , Ácido Gástrico/metabolismo , Mucosa Gástrica/microbiologia , Hepcidinas , Humanos , Hibridização In Situ , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Células Parietais Gástricas/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa
6.
Microorganisms ; 11(6)2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37375083

RESUMO

BACKGROUND: Helicobacter pylori (H. pylori) has definite or possible associations with multiple local and distant manifestations. H. pylori has been isolated from multiple sites throughout the body, including the nose. Clinical non-randomized studies with H. pylori report discrepant data regarding the association between H. pylori infection and nasal polyps. The aim of this first systematic review and meta-analysis was the assessment of the strength of the association between H. pylori infection and incidence of nasal polyps. METHODS: We performed an electronic search in the three major medical databases, namely PubMed, EMBASE and Cochrane, to extract and analyze data as per PRISMA guidelines. RESULTS: Out of 57 articles, 12 studies were graded as good quality for analysis. Male-to-female ratio was 2:1, and age ranged between 17-78 years. The cumulative pooled rate of H. pylori infection in the nasal polyp group was 32.3% (controls 17.8%). The comparison between the two groups revealed a more significant incidence of H. pylori infection among the nasal polyp group (OR 4.12), though with high heterogeneity I2 = 66%. Subgroup analysis demonstrated that in European studies, the prevalence of H. pylori infection among the nasal polyp group was significantly higher than in controls, yielding null heterogeneity. Subgroup analysis based on immunohistochemistry resulted in null heterogeneity with preserving a statistically significant difference in H. pylori infection prevalence between the groups. CONCLUSION: The present study revealed a positive association between H. pylori infection and nasal polyps.

7.
Dig Dis Sci ; 57(11): 2988-94, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22674401

RESUMO

BACKGROUND: Homozygous C282Y mutation in HFE gene is responsible for the majority of hereditary hemochromatosis cases. Since 1996 this mutation can be identified by a simple genetic test. AIMS: To determine the clinical presentations in patients with homozygous HFE C282Y mutation and the impact of genetic testing on the time needed for diagnosis. METHODS: A total of 414 patients diagnosed with C282Y homozygous hereditary hemochromatosis before and after the introduction of genetic testing were evaluated regarding symptoms and clinical findings at diagnosis as well as first hemochromatosis-related clinical features in their past medical history. RESULTS: At the time of diagnosis, the predominant symptom was joint pain, in particular of the hands/wrists. Those patients presenting with hand/wrist arthralgia had significantly higher ferritin levels than patients without this joint involvement (p = 0.0005 for males and p < 0.0001 for females). After the introduction of the HFE genetic test an earlier diagnosis after first onset of hemochromatosis-associated clinical features was observed between 2006 and 2009 vs. 2000-2005 p = 0.01). CONCLUSIONS: Arthralgia, in particular of the hands/wrists, is a hallmark of hereditary hemochromatosis and its presence is associated with higher ferritin levels. Despite the availability of a genetic test, it often takes more than 6 years from the first onset of clinical features to diagnose hereditary hemochromatosis. This underlines the importance of raising the awareness of hemochromatosis and its typical clinical presentations.


Assuntos
Testes Genéticos/métodos , Hemocromatose/diagnóstico , Hemocromatose/genética , Antígenos de Histocompatibilidade Classe I/genética , Adulto , Comorbidade , Feminino , Homozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Estudos Retrospectivos , Estatísticas não Paramétricas , Fatores de Tempo
8.
Ann Surg Open ; 3(2): e154, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37601610

RESUMO

Objective: To assess whether prophylactic irrigation and passive drainage of pancreatico-jejunal anastomosis could reduce leak and mortality rates after high-risk pancreaticoduodenectomies. Background: Postoperative pancreatic fistula (POPF) is a life-threatening complication following pancreaticoduodenectomy. Several risk factors have been proposed likewise potential mitigation strategies. Regarding the latter, surgical drain policy remains a "hot topic." We propose an innovative approach to mitigate POPF and POPF-related mortality following high-risk pancreaticoduodenectomies. Methods: One hundred fifty-seven patients undergoing pancreaticoduodenectomy between January 2012 and November 2021 were included in the study. Subjects with main pancreatic duct ≤ 3 mm and soft parenchyma were classified as high-risk for POPF development. Since August 2015, high-risk patients received prophylactic irrigation and drainage of the perianastomotic area. These patients were compared with risk-matched historical controls. Results: We identified 73 high-risk patients. Of these, the 47 subjects receiving prophylactic perianastomotic irrigation showed significantly lower POPF rates (12.7% vs 69.2%, P < 0.001). Multivariate regression analysis confirmed the significant association between irrigation drainages and POPF (odds ratio 0.014, P = 0.01). Although not significant, mortality was lower in the irrigation group (4.2% vs 13.0%, P = 0.340). However, none of the fatalities in the irrigation-drainage group were POPF-related. No significant difference in length of hospital stay was observed between the 2 groups (18.0 vs 21.0 days, P = 0.091). Conclusions: Irrigation and drainage of the perianastomotic area represents a powerful approach to reduce POPF and, potentially, mortality after high-risk pancreaticoduodenectomies.

9.
Haematologica ; 96(12): 1761-9, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21859731

RESUMO

BACKGROUND: Increased levels of hepcidin, the master regulator of iron homeostasis, contribute to the diversion of iron underlying the anemia of chronic disease. Yet hepcidin levels are low in anemia of chronic disease with concomitant true iron deficiency. Here we clarify the different underlying pathways regulating hepcidin expression under these conditions in vivo. DESIGN AND METHODS: We used rat models of iron deficiency anemia, anemia of chronic disease and anemia of chronic disease with concomitant true iron deficiency and investigated upstream signaling pathways controlling hepcidin transcription in the liver. Protein and mRNA levels of iron metabolism genes and genes involved in SMAD1/5/8 and STAT3 signaling were determined by RT-PCR, Western blotting and immunohistochemistry. RESULTS: SMAD1/5/8 phosphorylation and in parallel hepcidin mRNA expression were increased in anemia of chronic disease but significantly down-regulated in anemia of chronic disease with concomitant iron deficiency, either on the basis of phlebotomy or dietary iron restriction. Iron deficiency resulted in reduced bone morphogenetic protein-6 expression and impaired SMAD1/5/8 phosphorylation and trafficking, two key events for hepcidin transcription. Reduced SMAD1/5/8 activity in association with phlebotomy was paralleled by increased expression of the inhibitory factor, SMAD7, dietary iron restriction appeared to impair hepcidin transactivating SMAD pathways via reduction of membrane bound hemojuvelin expression. CONCLUSIONS: This study evaluated hepcidin signaling pathways in anemia of chronic disease with/without concomitant iron deficiency in vivo. While iron deficiency in general decreased bone morphogenetic protein-6 expression, phlebotomy or dietary iron restriction inhibited inflammation driven SMAD1/5/8 mediated hepcidin formation by different pathways, indicating alternate hierarchic signaling networks as a function of the mode and kinetics of iron deficiency. Nonetheless, iron deficiency inducible regulatory pathways can reverse inflammation mediated stimulation of hepcidin expression.


Assuntos
Anemia Ferropriva/metabolismo , Peptídeos Catiônicos Antimicrobianos/biossíntese , Regulação da Expressão Gênica , Fígado/metabolismo , Transdução de Sinais , Anemia Ferropriva/patologia , Animais , Doença Crônica , Modelos Animais de Doenças , Feminino , Hepcidinas , Ferro/metabolismo , Fígado/patologia , Fosforilação , RNA Mensageiro/biossíntese , Ratos , Ratos Endogâmicos Lew , Fator de Transcrição STAT3/metabolismo , Proteínas Smad/metabolismo
10.
Dig Dis Sci ; 56(2): 596-601, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21221795

RESUMO

BACKGROUND AND AIMS: Tissue specimen collection represents a cornerstone in diagnosis of proximal biliary tract malignancies offering great specificity, but only limited sensitivity. To improve the tumor detection rate, we developed a new method of forceps biopsy and compared it prospectively with endoscopic transpapillary brush cytology. PATIENTS AND METHODS: 43 patients with proximal biliary stenoses, which were suspect for malignancy, undergoing endoscopic retrograde cholangiography were prospectively recruited and subjected to both biopsy [using a double-balloon enteroscopy (DBE) forceps under a guidance of a pusher and guiding catheter with guidewire] and transpapillary brush cytology. The cytological/histological findings were compared with the final clinical diagnosis. RESULTS: 35 out of 43 patients had a malignant disease (33 cholangiocarcinomas, 1 hepatocellular carcinoma, 1 gallbladder carcinoma). The sensitivity of cytology and biopsy in these patients was 49 and 69%, respectively. The method with DBE forceps allowed a pinpoint biopsy of the biliary stenoses. Both methods had 100% specificity, and, when combined, 80% of malignant processes were detected. All patients with non-malignant conditions were correctly assigned by both methods. No clinically relevant complications were observed. CONCLUSIONS: The combination of forceps biopsy and transpapillary brush cytology is safe and offers superior detection rates compared to both methods alone, and therefore represents a promising approach in evaluation of proximal biliary tract processes.


Assuntos
Neoplasias dos Ductos Biliares/diagnóstico , Biópsia/métodos , Carcinoma Hepatocelular/diagnóstico , Colangiocarcinoma/diagnóstico , Neoplasias Hepáticas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares Intra-Hepáticos/patologia , Colangiopancreatografia Retrógrada Endoscópica , Vesícula Biliar/patologia , Humanos , Fígado/patologia , Pessoa de Meia-Idade , Instrumentos Cirúrgicos , Adulto Jovem
11.
J Hepatol ; 53(2): 313-7, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20472317

RESUMO

BACKGROUND & AIMS: In patients with primary sclerosing cholangitis (PSC) treated with ursodeoxycholic acid (UDCA), dominant stenoses are associated with reduced survival free of liver transplantation and the role of inflammatory bowel disease (IBD) in such patients is unclear. In the present study the influence of IBD on the outcome in patients with and without dominant stenosis has been evaluated. METHODS: In a prospective study, 171 patients were followed for up to 20 years. All patients were treated with ursodeoxycholic acid; patients with dominant stenosis in addition were treated endoscopically. RESULTS: A total of 97 out of 171 patients had or developed dominant bile duct stenoses and 96 out of 97 were treated endoscopically. In patients with dominant stenosis without IBD, no carcinoma was found whereas all six bile duct and two gallbladder carcinomas and 6/7 colo-rectal carcinomas were found in patients with dominant stenosis with IBD (p=0.012). In patients without dominant stenosis but with IBD, 1 out of 7 had colo-rectal carcinoma. In patients with dominant stenosis without IBD (n=30), actuarial survival free of liver transplantation at 18 years was 77.8% and in those with dominant stenosis and inflammatory bowel disease (n=67) it was 23.0% (p=0.045). In PSC patients without dominant stenosis and without IBD (n=21), actuarial survival free of liver transplantation at 18 years was 68.2% and in those with inflammatory bowel disease (n=53) it was 78.4% (n.s.). CONCLUSIONS: In patients without dominant stenosis, IBD had no effect on the incidence of carcinomas and survival. Only patients with dominant stenosis with additional IBD had an increased carcinoma rate. This may contribute to the reduced survival free of liver transplantation in such patients.


Assuntos
Neoplasias dos Ductos Biliares/epidemiologia , Colangite Esclerosante/complicações , Colangite Esclerosante/mortalidade , Colestase/complicações , Neoplasias Colorretais/epidemiologia , Neoplasias da Vesícula Biliar/epidemiologia , Doenças Inflamatórias Intestinais/complicações , Adolescente , Adulto , Idoso , Colangite Esclerosante/terapia , Colestase/epidemiologia , Comorbidade , Feminino , Seguimentos , Humanos , Incidência , Doenças Inflamatórias Intestinais/epidemiologia , Estimativa de Kaplan-Meier , Transplante de Fígado , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Taxa de Sobrevida , Ácido Ursodesoxicólico/uso terapêutico , Adulto Jovem
12.
Gastrointest Endosc ; 71(3): 527-34, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20189511

RESUMO

BACKGROUND: Primary sclerosing cholangitis is characterized by progressive fibrotic inflammation and obliteration of intra- and/or extrahepatic bile ducts. Total or subtotal stenoses of major bile ducts are associated with reduced survival. OBJECTIVE: To evaluate the outcome after long-term endoscopic treatment. DESIGN: Prospective, single-center study. SETTING: Tertiary care academic medical center. PATIENTS: A total of 171 patients treated with ursodeoxycholic acid were followed for as long as 20 years. At entry, 20 patients had dominant stenoses, and during a median follow-up period of 7.1 years, dominant stenosis developed in another 77. INTERVENTIONS: Ninety-six patients with dominant stenoses were treated by repeated balloon dilation; 5 patients with complete obstruction with bacterial cholangitis were stented. MAIN OUTCOME MEASUREMENTS: Survival free of liver transplantation, number of procedures, complications. RESULTS: In total, 500 balloon dilations were performed and 5 stents were placed. Complications were pancreatitis (2.2%), bacterial cholangitis (1.4%), and bile duct perforation (0.2%); there were no deaths. Repeated endoscopic interventions allowed the preservation of a functioning common bile duct and of at least 1 hepatic duct up to 2 cm above the bifurcation in all patients. Progression of intrahepatic bile duct and liver disease led to the need for liver transplantation in 22 of 96 patients. Five years after the first dilation of a dominant stenosis, the survival free of liver transplantation rate was 81%, and after 10 years, it was 52%. LIMITATIONS: Single-center study, no control group, primary end-stage liver disease excluded. CONCLUSION: Repeated endoscopic balloon dilations of dominant stenoses allow the preservation of a functioning common bile duct for many years.


Assuntos
Cateterismo/métodos , Colangite Esclerosante/patologia , Colangite Esclerosante/terapia , Colangite Esclerosante/cirurgia , Endoscopia do Sistema Digestório , Feminino , Humanos , Transplante de Fígado/estatística & dados numéricos , Masculino , Estudos Prospectivos , Retratamento , Stents , Resultado do Tratamento
13.
J Hepatol ; 51(1): 149-55, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19410324

RESUMO

BACKGROUND/AIMS: In primary sclerosing cholangitis (PSC) dominant stenoses are frequently associated with bacterial, and in part, also fungal infections of the bile ducts. In the present study, the influence of dominant stenoses and of biliary infections on the long-term outcome was studied. METHODS: In a prospective study, 171 patients were followed up for 20 years. All patients were treated with ursodeoxycholic acid. Dominant stenoses were treated endoscopically and during endoscopic procedures, bile was obtained for microbiologic analysis. RESULTS: Of the 171 patients, 97 had or developed major bile duct stenoses and 96/97 were treated endoscopically. In the 55/97 patients with dominant stenosis, bile samples were obtained and of these, 41/55 had bacteria, five had also Candida and 2/55 had only Candida in their bile. Survival free of liver transplantation in patients without dominant stenosis at 18 years was 73.1% and of patients with dominant stenosis was 25.0% (p=0.011). Bacteria in bile had no effect on survival whereas Candida in bile was associated with reduced survival (p=0.025). CONCLUSIONS: In patients with dominant stenosis, survival free of liver transplantation is reduced. Bacteria in bile do not worsen the outcome if dominant stenoses are opened endoscopically and infection is adequately treated with antibiotics. Candida in bile is associated with a poor prognosis and these patients need liver transplantation relatively soon.


Assuntos
Bactérias/isolamento & purificação , Bile/microbiologia , Candida/isolamento & purificação , Colangite Esclerosante/mortalidade , Colestase/complicações , Adolescente , Adulto , Idoso , Antibacterianos/uso terapêutico , Criança , Colangite Esclerosante/complicações , Colangite Esclerosante/tratamento farmacológico , Colestase/terapia , Feminino , Humanos , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Ácido Ursodesoxicólico/uso terapêutico
14.
BMC Cell Biol ; 9: 45, 2008 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-18700980

RESUMO

BACKGROUND: Mechanisms of long chain fatty acid uptake across the plasma membrane are important targets in treatment of many human diseases like obesity or hepatic steatosis. Long chain fatty acid translocation is achieved by a concert of co-existing mechanisms. These lipids can passively diffuse, but certain membrane proteins can also accelerate the transport. However, we now can provide further evidence that not only proteins but also lipid microdomains play an important part in the regulation of the facilitated uptake process. METHODS: Dynamic association of FAT/CD36 a candidate fatty acid transporter with lipid rafts was analysed by isolation of detergent resistant membranes (DRMs) and by clustering of lipid rafts with antibodies on living cells. Lipid raft integrity was modulated by cholesterol depletion using methyl-beta-cyclodextrin and sphingolipid depletion using myriocin and sphingomyelinase. Functional analyses were performed using an [3H]-oleate uptake assay. RESULTS: Overexpression of FAT/CD36 and FATP4 increased long chain fatty acid uptake. The uptake of long chain fatty acids was cholesterol and sphingolipid dependent. Floating experiments showed that there are two pools of FAT/CD36, one found in DRMs and another outside of these domains. FAT/CD36 co-localized with the lipid raft marker PLAP in antibody-clustered domains at the plasma membrane and segregated away from the non-raft marker GFP-TMD. Antibody cross-linking increased DRM association of FAT/CD36 and accelerated the overall fatty acid uptake in a cholesterol dependent manner. Another candidate transporter, FATP4, was neither present in DRMs nor co-localized with FAT/CD36 at the plasma membrane. CONCLUSION: Our observations suggest the existence of two pools of FAT/CD36 within cellular membranes. As increased raft association of FAT/CD36 leads to an increased fatty acid uptake, dynamic association of FAT/CD36 with lipid rafts might regulate the process. There is no direct interaction of FATP4 with lipid rafts or raft associated FAT/CD36. Thus, lipid rafts have to be considered as targets for the treatment of lipid disorders.


Assuntos
Antígenos CD36/metabolismo , Colesterol/metabolismo , Ácidos Graxos/metabolismo , Microdomínios da Membrana/metabolismo , Fosfatase Alcalina , Animais , Células COS , Chlorocebus aethiops , Imunofluorescência , Proteínas Ligadas por GPI , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Humanos , Isoenzimas/metabolismo , Camundongos , Ácido Oleico/metabolismo , Esfingolipídeos/biossíntese , Transfecção , Células Vero
15.
Virchows Arch ; 453(4): 339-45, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18769938

RESUMO

Secondary sclerosing cholangitis (SSC) is a chronic cholestatic disorder caused by mechanical, infectious, toxic, or ischemic factors. A new variant of SSC occurring after long-term treatment in intensive care units (ICU) has been recently described and characterized from the clinical point of view. The aim of this study was the histomorphological characterization of ICU-treatment-related SSC (ICU-SSC) and the definition of histological changes occurring over time based on the morphological findings. Liver biopsies of ten patients affected by ICU-SSC obtained at different time points (1.5 to 57 months) after the initial injury were analyzed. The main morphological alterations included degenerative changes of portal bile ducts, portal edema, inflammation, and fibrosis as well as biliary interface activity and bilirubinostasis. Perivenular necroses and bile infarcts were found in eight and six patients, respectively. Bile duct loss was not observed. No correlation between morphological features of biopsies and liver chemistry tests or outcome could be established. Based on the morphological observation, a possible disease-progression model starting with an initial damage of portal bile ducts (primary insult) with associated portal/periportal changes (inflammation, ductular reaction) and resulting in secondary parenchymal changes is proposed.


Assuntos
Colangite Esclerosante/diagnóstico , Colangite Esclerosante/etiologia , Unidades de Terapia Intensiva , Fígado/patologia , Adolescente , Adulto , Idoso , Doenças dos Ductos Biliares/complicações , Ductos Biliares/patologia , Biópsia , Colangite Esclerosante/mortalidade , Colangite Esclerosante/patologia , Colestase/diagnóstico , Colestase/etiologia , Diagnóstico Diferencial , Progressão da Doença , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
16.
Scand J Gastroenterol ; 43(4): 447-55, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18365910

RESUMO

OBJECTIVE: The peptide hormones guanylin and uroguanylin and their receptor, guanylate cyclase C (GC-C), are expressed in pancreatic duct cells. In colon cancer, guanylin peptides are shown to exert strong anti-tumor activity through the GC-C pathway. The objective of this study was to analyze the role of guanylin and uroguanylin in human pancreatic cancer. MATERIAL AND METHODS: Quantitative real-time polymerase chain reaction (QRT-PCR) was used to show the expression of guanylin, uroguanylin and GC-C in specimens of human pancreatic cancer, chronic pancreatitis donor and in pancreatic tumor cell lines. The presence of guanylins and GC-C in tumor cell lines and in pancreatic cancer tissues was shown by immunofluorescence and immunohistochemistry. The effect of guanylin and uroguanylin on cell cycle and cell death of pancreatic cancer cells was investigated by fluorescence activated cell sorter (FACS) analysis using annexin and propidium iodide. In addition, the growth inhibitory effect of guanylins on pancreatic cancer cells was assessed using the MTT assay. RESULTS: Guanylin, uroguanylin and GC-C were expressed at mRNA and protein levels in pancreatic cancer and cancer cell lines. As shown by QRT-PCR, GC-C expression was significantly up-regulated in pancreatic cancer compared with that in healthy pancreatic tissues (p<0.00001) and chronic pancreatitis (p<0.05). Guanylin and uroguanylin were not up-regulated in pancreatic cancer. The MTT assay revealed significant inhibition of pancreatic cancer cell proliferation by uroguanylin in a dose-dependent fashion, whereas Panc1 and Capan1 cell lines were significantly inhibited already at the lowest uroguanylin concentration (2 nM, p<0.05). CONCLUSIONS: Our data suggest therapeutic properties of uroguanylin in pancreatic cancer via GC-C-dependent mechanisms. In addition, determination of GC-C expression might be a useful marker for differentiation between pancreatic cancer and chronic pancreatitis.


Assuntos
Carcinoma Ductal Pancreático/patologia , Divisão Celular/efeitos dos fármacos , Peptídeos Natriuréticos/farmacologia , Neoplasias Pancreáticas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Apoptose , Biomarcadores Tumorais/análise , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral/metabolismo , Linhagem Celular Tumoral/patologia , Doença Crônica , Feminino , Hormônios Gastrointestinais/metabolismo , Hormônios Gastrointestinais/farmacologia , Guanilato Ciclase/metabolismo , Guanilato Ciclase/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos Natriuréticos/metabolismo , Peptídeos Natriuréticos/uso terapêutico , Pâncreas/metabolismo , Neoplasias Pancreáticas/metabolismo , Pancreatite/patologia , Reação em Cadeia da Polimerase
17.
World J Gastroenterol ; 14(10): 1528-33, 2008 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-18330942

RESUMO

AIM: To investigate a possible increase of basolateral expression of carcinoembryonic antigen (CEA) by interfering with the apical transport machinery, we studied the effect of cholesterol depletion on CEA sorting and secretion. METHODS: Cholesterol depletion was performed in polarized Caco-2 cells using lovastatin and methyl-beta-cyclodextrin. RESULTS: We show that CEA is predominantly expressed and secreted at the apical surface. Reduction of the cholesterol level of the cell by 40%-50% with lovastatin and methyl-beta-cyclodextrin led to a significant change of the apical-to-basolateral transport ratio towards the basolateral membrane. CONCLUSION: As basolateral expression of CEA has been suggested to have anti-inflamatory properties, Cholesterol depletion of enterocytes might be a potential approach to influence the course of inflammatory bowel disease.


Assuntos
Adenocarcinoma/metabolismo , Anticolesterolemiantes/uso terapêutico , Antígeno Carcinoembrionário/metabolismo , Colesterol/metabolismo , Neoplasias do Colo/metabolismo , Doenças Inflamatórias Intestinais/tratamento farmacológico , beta-Ciclodextrinas/uso terapêutico , Adenocarcinoma/patologia , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Células CACO-2 , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Neoplasias do Colo/patologia , Humanos , Doenças Inflamatórias Intestinais/metabolismo , Lovastatina/uso terapêutico
18.
Nephrology (Carlton) ; 13(7): 636-45, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18808386

RESUMO

AIM: Anaemia is prevalent in chronic kidney disease (CKD) and induces significant changes in heart and kidney. In this study, we evaluated the relationship between iron metabolism, hepcidin and inflammation focusing on left ventricular (LV) function, in a remnant kidney rat model. METHODS: Rats with 5/6 subtotal nephrectomy (STNx) and sham operation. Haemoglobin (Hb), serum iron (SI), fractional shortening (FS%) by echocardiograms were evaluated. Six months after STNx, the heart and kidney were processed by immunohistochemistry with antibodies against hypoxia-inducible factors (HIF)-1alpha, erythropoietin (EPO), pro-hepcidin, caspase-3, tumour necrosis factor (TNF)-alpha and interleukin (IL)-6. RESULTS: Hb (g/dL) STNx: 10.8 +/- 0.8, sham: 14.7 +/- 0.6 (P < 0.01); SI (microg/dL) STNx: 154.5 +/- 24.5, sham: 287.5 +/- 32.1 (P < 0.01); heart weight (g) STNx: 2.21 +/- 0.15, sham: 1.12 +/- 0.12 (P < 0.01); FS% STNx: 28.4 +/- 2.5, sham: 45.1 +/- 4.1 (P < 0.01). There was a correlation between Hb and FS% (r = 0.95; P < 0.01) and between SI and FS% (r = 0.86; P < 0.01) in the STNx group. Tissue ferritin was reduced in heart and in kidney in the STNx group (P < 0.01). HIF-1alpha was expressed in cardiomyocytes (positive cells/area) STNx: 32 +/- 5, sham: 4 +/- 1; and tubular cells in STNx group: 70 +/- 16, sham: 10 +/- 3, P < 0.01. Hepcidin (% staining/area) in heart STNx: 6.6 +/- 0.8, sham: 0.8 +/- 0.1; in kidney STNx: 9.7 +/- 2.6, sham: 3.7 +/- 0.9, P < 0.01. EPO (% staining/area) in heart STNx: 2.6 +/- 0.4, sham: 0.8 +/- 0.2; in kidney STNx: 10.2 +/- 1.4, sham: 1.2 +/- 0.6; P < 0.01. In STNx group positive caspase-3, TNF-alpha and IL-6 were detected in heart and renal cells. CONCLUSION: Low LV performance is associated with iron deficiency anaemia in rats with CKD. Furthermore, overproduction of HIF-1alpha and the activation of caspase-3 seem to be associated with iron deficiency and with inflammatory markers. Hepcidin seems to plays a key role in this mechanism.


Assuntos
Anemia Ferropriva/etiologia , Peptídeos Catiônicos Antimicrobianos/fisiologia , Miocárdio/metabolismo , Insuficiência Renal/complicações , Animais , Caspase 3/metabolismo , Eritropoetina/biossíntese , Ferritinas/análise , Hepcidinas , Subunidade alfa do Fator 1 Induzível por Hipóxia/análise , Imuno-Histoquímica , Interleucina-6/análise , Rim/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Insuficiência Renal/fisiopatologia , Fator de Necrose Tumoral alfa/análise , Função Ventricular Esquerda
20.
Endocrinology ; 148(6): 2663-8, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17363462

RESUMO

The peptide hormone hepcidin plays a central role in iron homeostasis. It is predominantly expressed in the liver and regulated by iron, hypoxia, and inflammation. Although it has been shown that iron plays a key pathophysiological role in cardiac diseases, including iron-overload cardiomyopathy, myocardial ischemia-reperfusion injury, and atherosclerosis, very little is known about the putative expression and the role of hepcidin in the heart. In the present study, expression and regulation of hepcidin in rat heart were analyzed. Basal cardiac expression of hepcidin was demonstrated on mRNA and protein level in vivo in a rat model and compared with its regulation in the liver. The cellular localization was analyzed by immunofluorescence microscopy. Sixteen hours after a single injection of turpentine, a more than 2-fold increase of cardiac hepcidin mRNA and a more than 3-fold increase of hepatic hepcidin mRNA was observed. In response to hypoxia, expression of hepcidin in the liver decreased. In contrast, hypoxia resulted in a strong up-regulation of hepcidin expression on mRNA and protein level in the heart, accompanied by an increased immunoreactivity of hepcidin pronounced at the myocardial intercalated disc area. The finding of a regulated expression of the iron-regulatory peptide hormone hepcidin in the heart suggests that hepcidin may have an important role in cardiac diseases.


Assuntos
Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/metabolismo , Inflamação/genética , Ferro/metabolismo , Miocárdio/metabolismo , Oxigênio/fisiologia , Animais , Hipóxia Celular/fisiologia , Regulação da Expressão Gênica , Cardiopatias/genética , Cardiopatias/metabolismo , Cardiopatias/patologia , Hepcidinas , Inflamação/metabolismo , Inflamação/patologia , Fígado/metabolismo , Masculino , Miocárdio/patologia , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA