RESUMO
Gastroesophageal reflux (GER) describes a process in which gastric contents travel retrograde into the esophagus. GER can be either a physiologic phenomenon that occurs in asymptomatic individuals or can potentially cause symptoms. When the latter occurs, this represents GER disease (GERD). The process by which GER transforms into GERD begins at the esophagogastric junction. Impaired clearance of the refluxate also contributes to GERD. Reflux causes degradation of esophageal mucosal defense. The refluxate triggers sensory afferents leading to symptom generation.
Assuntos
Esofagite Péptica/fisiopatologia , Refluxo Gastroesofágico/fisiopatologia , Adulto , Diafragma/fisiopatologia , Progressão da Doença , Esofagite Péptica/etiologia , Junção Esofagogástrica/fisiopatologia , Esôfago/fisiopatologia , Feminino , Refluxo Gastroesofágico/etiologia , Hérnia Hiatal/complicações , Hérnia Hiatal/fisiopatologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Fibrosing cholestatic hepatitis (FCH) is an uncommon but potentially fatal complication of recurrent hepatitis C (HCV) in liver transplant recipients. METHODS: We matched the treatment outcomes of 10 liver transplant recipients who developed FCH with those of 10 recipients with recurrent HCV without FCH treated with sofosbuvir and ribavirin. RESULTS: Baseline mean alanine transaminase, aspartate transaminase, alkaline phosphatase, and total bilirubin were 186 U/L, 197 U/L, 243 U/L, and 6.7 mg/dL, respectively, in the FCH recipients and 82 U/L, 60 U/L, 110 U/L, and 0.99 mg/dL, respectively, in non-FCH recipients. The sustained viral response in FCH and non-FCH recipients was 40% and 80%, respectively. One-yr patient and graft survival rates were 90% and 80%, respectively, in FCH recipients, and 100% in non-FCH recipients. Seven FCH and six non-FCH recipients were treated for anemia with blood transfusion and/or erythropoietin growth factors. CONCLUSION: Our results suggest that the use of sofosbuvir and ribavirin is effective and tolerable in liver transplant recipients treated for recurrent FCH. There is a trend of lower sustained viral response, patient survival, and graft survival in the FCH recipients.
Assuntos
Antivirais/uso terapêutico , Colestase Intra-Hepática/tratamento farmacológico , Hepatite C Crônica/tratamento farmacológico , Cirrose Hepática/tratamento farmacológico , Transplante de Fígado , Complicações Pós-Operatórias/tratamento farmacológico , Adulto , Idoso , Estudos de Casos e Controles , Colestase Intra-Hepática/etiologia , Colestase Intra-Hepática/mortalidade , Quimioterapia Combinada , Feminino , Seguimentos , Sobrevivência de Enxerto , Hepatite C Crônica/mortalidade , Hepatite C Crônica/cirurgia , Humanos , Cirrose Hepática/etiologia , Cirrose Hepática/mortalidade , Masculino , Análise por Pareamento , Pessoa de Meia-Idade , Complicações Pós-Operatórias/mortalidade , Recidiva , Estudos Retrospectivos , Ribavirina/uso terapêutico , Sofosbuvir/uso terapêutico , Resultado do TratamentoRESUMO
Luminal amino acids and lack of luminal acidity as a result of acid neutralization by intragastric foodstuffs are powerful signals for acid secretion. Although the hormonal and neural pathways underlying this regulatory mechanism are well understood, the nature of the gastric luminal pH sensor has been enigmatic. In clinical studies, high pH, tryptic peptides, and luminal divalent metals (Ca(2+) and Mg(2+)) increase gastrin release and acid production. The calcium-sensing receptor (CaSR), first described in the parathyroid gland but expressed on gastric G cells, is a logical candidate for the gastric acid sensor. Because CaSR ligands include amino acids and divalent metals, and because extracellular pH affects ligand binding in the pH range of the gastric content, its pH, metal, and nutrient-sensing functions are consistent with physiologic observations. The CaSR is thus an attractive candidate for the gastric luminal sensor that is part of the neuroendocrine negative regulatory loop for acid secretion.
Assuntos
Ácido Gástrico/metabolismo , Mucosa Gástrica/fisiologia , Receptores de Detecção de Cálcio/fisiologia , Aminoácidos/agonistas , Animais , Retroalimentação Fisiológica , Células Secretoras de Gastrina/metabolismo , Gastrinas/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Neurônios Aferentes/fisiologia , Células Secretoras de Somatostatina/fisiologiaRESUMO
Epiregulin (EPI) and amphiregulin (AR) are epidermal growth factor receptor (EGFR) ligands implicated in mucosal repair and tumorigenesis. We have shown that Toll-like receptor 4 (TLR4) induces intestinal epithelial cell (IEC) proliferation by activating EGFR through AR expression. We examined whether TLR4 differentially regulates expression of EGFR ligands in response to mucosal injury. The human IEC line SW480 was examined expression of EGFR ligands, EGFR phosphorylation, and proliferation in response to lipopolysaccharide (LPS). Small-interfering RNA (siRNA) was used to block TLR4. Neutralizing antibodies to EGFR ligands were used to examine inhibition of LPS-dependent EGFR activation. Acute colitis and recovery were examined in the mice given 2.5% dextran sodium sulfate (DSS). Colonic secretion of EPI and AR was analyzed by enzyme-linked immunosorbent assay. LPS selectively induces EPI and AR but not other EGFR ligands. LPS induced early EPI mRNA expression between 30 min and 24 h. The neutralizing antibodies to EPI and AR prevented activation of EGFR by LPS. LPS induces IEC proliferation (200%, P=0.01) in 24 h but blocking EPI and AR significantly decreased proliferation. In vivo, mucosal EPI and AR expression are significantly decreased in TLR4(-/-) mice (P=0.02) compared to wild-type mice during acute colitis. EPI and AR exhibit different kinetics in response to mucosal damage: EPI expression is upregulated acutely at day 7 of DSS, but falls during recovery at day 14. By contrast, a sustained upregulation of AR expression is seen during mucosal injury and repair. We show that TLR4 regulates EPI and AR expression and that both these EGFR ligands are necessary for optimal proliferation of IEC. The diverse kinetics of EPI and AR expression suggest that they function in distinct roles with respect to acute injury vs repair. Our results highlight the role of bacterial sensing for IEC homeostasis and may lead to targeted therapy for mucosal healing and prevention of tumorigenesis.
Assuntos
Fator de Crescimento Epidérmico/genética , Fator de Crescimento Epidérmico/metabolismo , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismo , Anfirregulina , Animais , Anticorpos Neutralizantes , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Colite/genética , Colite/imunologia , Colite/metabolismo , Sulfato de Dextrana/imunologia , Sulfato de Dextrana/metabolismo , Sulfato de Dextrana/farmacologia , Família de Proteínas EGF , Ensaio de Imunoadsorção Enzimática , Fator de Crescimento Epidérmico/imunologia , Epirregulina , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Receptores ErbB/genética , Receptores ErbB/imunologia , Receptores ErbB/metabolismo , Glicoproteínas , Humanos , Peptídeos e Proteínas de Sinalização Intercelular , Lipopolissacarídeos/imunologia , Lipopolissacarídeos/metabolismo , Camundongos , Camundongos Knockout , Mucosa/metabolismo , Receptor 4 Toll-Like/genética , Regulação para Cima/efeitos dos fármacosRESUMO
BACKGROUND: Patients with ulcerative colitis are at increased risk for developing colorectal cancer. We have shown that Toll-like receptor-4 (TLR4) is overexpressed in human colitis-associated cancer (CAC) and that mice deficient in TLR4 are markedly protected against colitis-associated neoplasia. We wished to elucidate the specific contributions of TLR4 signaling by myeloid cells and colonic epithelial cells (CEC) in colitis-associated tumorigenesis. METHODS: TLR4-deficient mice or wildtype littermates (WT) were transplanted with bone marrow (BM) cells: TLR4(-/-) BM-->WT mice (TLR4-expressing CEC) and WT BM-->TLR4(-/-) mice (TLR4-expressing myeloid cells). Colitis-associated neoplasia was induced by azoxymethane (AOM 7.3 mg/kg) injection and 2 cycles of dextran sodium sulfate (DSS) treatment. RESULTS: The number and size of dysplastic lesions were greater in TLR4(-/-) BM-->WT mice than in WT BM-->TLR4(-/-) mice (P < 0.005). Histologically, TLR4(-/-) BM-->WT mice had greater numbers of mucosal neutrophils and macrophages compared to WT BM-->TLR4(-/-) mice. The chemokines KC and CCL2, important in recruitment of neutrophils and macrophages, respectively, were induced in mice expressing TLR4 in CEC rather than the myeloid compartment. The lamina propria infiltrate of mice expressing TLR4 in CEC was characterized by macrophages expressing Cox-2. Moreover, mice expressing TLR4 in CEC rather than the myeloid compartment had increased production of amphiregulin and EGFR activation. CONCLUSIONS: These findings indicate that TLR4 signaling on CEC is necessary for recruitment and activation of Cox-2-expressing macrophages and increasing the number and size of dysplastic lesions. Our results implicate innate immune signaling on CEC as a key regulator of a tumor-promoting microenvironment.
Assuntos
Colite Ulcerativa/imunologia , Neoplasias Colorretais/imunologia , Transdução de Sinais/imunologia , Receptor 4 Toll-Like/imunologia , Animais , Transplante de Medula Óssea , Colite Ulcerativa/epidemiologia , Colite Ulcerativa/patologia , Neoplasias Colorretais/epidemiologia , Neoplasias Colorretais/patologia , Ciclo-Oxigenase 2/genética , Ciclo-Oxigenase 2/metabolismo , Dinoprostona/metabolismo , Regulação Neoplásica da Expressão Gênica/imunologia , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Fatores de Risco , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismoRESUMO
The effectiveness of low-dose omeprazole as primary prevention of gastrointestinal adverse events due to episodic use of non-selective NSAIDs was evaluated. Healthy adults aged 50-75 who did not take chronic NSAIDs were randomized to a 6.5-day treatment of naproxen 500 mg twice daily plus omeprazole 20 mg daily or naproxen 500 mg twice daily plus placebo. Seventy subjects were enrolled (mean age 58.6 years, proportion >60 = 41.4%). Subjects receiving naproxen plus omeprazole developed fewer gastroduodenal ulcers compared to subjects receiving naproxen plus placebo (11.8% vs. 46.9%, P = 0.002). Likewise, naproxen plus omeprazole was associated with a decreased risk of ulceration and/or >5 erosions (38.2% vs. 81.3%, P < or = 0.001), and a smaller change in dyspepsia score. Considering their relatively low cost, ready availability, and favorable safety profile, low-dose PPI co-prescription in healthy adults requiring short-term therapy with non-selective NSAIDs may be reasonable.
Assuntos
Anti-Inflamatórios não Esteroides/efeitos adversos , Úlcera Duodenal/prevenção & controle , Naproxeno/efeitos adversos , Omeprazol/administração & dosagem , Inibidores da Bomba de Prótons/administração & dosagem , Úlcera Gástrica/prevenção & controle , Idoso , Método Duplo-Cego , Úlcera Duodenal/induzido quimicamente , Úlcera Duodenal/microbiologia , Úlcera Duodenal/patologia , Duodenoscopia , Dispepsia/induzido quimicamente , Dispepsia/prevenção & controle , Feminino , Gastroscopia , Helicobacter pylori/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Valores de Referência , Úlcera Gástrica/induzido quimicamente , Úlcera Gástrica/microbiologia , Úlcera Gástrica/patologia , Resultado do TratamentoRESUMO
Abnormal T cell responses to commensal bacteria are involved in the pathogenesis of inflammatory bowel disease. MyD88 is an essential signal transducer for TLRs in response to the microflora. We hypothesized that TLR signaling via MyD88 was important for effector T cell responses in the intestine. TLR expression on murine T cells was examined by flow cytometry. CD4(+)CD45Rb(high) T cells and/or CD4(+)CD45Rb(low)CD25(+) regulatory T cells were isolated and adoptively transferred to RAG1(-/-) mice. Colitis was assessed by changes in body weight and histology score. Cytokine production was assessed by ELISA. In vitro proliferation of T cells was assessed by [(3)H]thymidine assay. In vivo proliferation of T cells was assessed by BrdU and CFSE labeling. CD4(+)CD45Rb(high) T cells expressed TLR2, TLR4, TLR9, and TLR3, and TLR ligands could act as costimulatory molecules. MyD88(-/-) CD4(+) T cells showed decreased proliferation compared with WT CD4(+) T cells both in vivo and in vitro. CD4(+)CD45Rb(high) T cells from MyD88(-/-) mice did not induce wasting disease when transferred into RAG1(-/-) recipients. Lamina propria CD4(+) T cell expression of IL-2 and IL-17 and colonic expression of IL-6 and IL-23 were significantly lower in mice receiving MyD88(-/-) cells than mice receiving WT cells. In vitro, MyD88(-/-) T cells were blunted in their ability to secrete IL-17 but not IFN-gamma. Absence of MyD88 in CD4(+)CD45Rb(high) cells results in defective T cell function, especially Th17 differentiation. These results suggest a role for TLR signaling by T cells in the development of inflammatory bowel disease.