RESUMO
A matched case-control study was used to determine pathogens and risk factors associated with gastroenteritis in a Taipei Emergency Department. Viruses (40.0%) were the leading cause of gastroenteritis, with noroviruses the most prevalent (33.2%). Bacteria were found in 26.0% of all cases, mostly suspected diarrheagenic E. coli (22.2%), followed by Salmonella spp. (5.4%) and Vibrio parahaemolyticus (4.2%). Giardia lamblia was identified in 16.4% of all cases. Statistical significance was noted for seven risk factors: taking antacids before gastroenteritis (OR = 3.91; 95% CI, 2.13, 7.15), other household members with gastroenteritis (OR = 5.18; 95% CI, 2.09, 12.85), attending a banquet (OR = 1.93; 95% CI, 1.25, 2.98), eating out (OR = 2.35; 95% CI, 1.30, 4.23), drinking bottled water (OR = 1.72; 95% CI, 1.07, 2.75), eating honey peaches (OR = 3.26; 95% CI, 1.24, 8.58), and eating raw oysters (OR = 3.24; 95% CI, 1.02, 10.28). Eating out was identified as the highest risk behavior, as measured by population attributable risk fraction (PAR) (50.9%). Respective PAR values for drinking bottled water, attending a banquet and taking antacids before illness were 19.7%, 19.6% and 17.6%. Of these, additional research on bottled water appears to be the highest priority, because this is the first time it has been identified as a risk factor for gastroenteritis.
Assuntos
Serviço Hospitalar de Emergência , Gastroenterite/epidemiologia , Gastroenterite/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Bactérias/classificação , Bactérias/isolamento & purificação , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Parasitos/classificação , Parasitos/isolamento & purificação , Prevalência , Fatores de Risco , Taiwan/epidemiologia , Vírus/classificação , Vírus/isolamento & purificação , Adulto JovemRESUMO
Because the transcription factor, nuclear factor (NF)-kappaB, plays a key role in cellular inflammatory and immune responses, components of the NF-kappaB-activating signaling pathways are frequently used as targets for anti-inflammatory agents. This study shows that 2-(3',4'-dihydroxyphenyl)-5-hydroxybenzo[b]furan (GF-015) and 2,3-di(3',4'-dihydroxy-transstyryl) pyridine (GF-90), two conjugated polyhydroxybenzene derivatives, inhibited a common step in NF-kappaB activation in human NCI-H292 epithelial cells by preventing tumor necrosis factor (TNF)-alpha- and 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced IkappaB kinase (IKK) complex activation. Both agents inhibited the TNF-alpha- or TPA-induced expression of cyclooxygenase (COX)-2 mRNA and protein, COX-2 promoter activity, and prostaglandin E2 (PGE2) production. Overexpression of wild-type NF-kappaB-inducing kinase, IKKalpha, and IKKbeta led, respectively, to 3.5-, 2.6-, and 2.6-fold increases in COX-2 promoter activity, and these effects were inhibited by both compounds. GF-015 and GF-90 also prevented the TNF-alpha- and TPA-induced activation of IKK and NF-kappaB-specific DNA-protein binding activity. These results suggest that the inhibitory effect of GF-015 and GF-90 on TNF-alpha-induced COX-2 protein expression was caused by suppression of IKK activity and NF-kappaB activation in the COX-2 promoter, resulting in attenuation of COX-2 gene expression and PGE2 production.
Assuntos
Anti-Inflamatórios/farmacologia , Benzofuranos/farmacologia , Proteínas I-kappa B , Isoenzimas/genética , NF-kappa B/metabolismo , Prostaglandina-Endoperóxido Sintases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Piridinas/farmacologia , Fator de Necrose Tumoral alfa/fisiologia , Células Cultivadas , Ciclo-Oxigenase 2 , DNA/efeitos dos fármacos , DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Dinoprostona/metabolismo , Ativação Enzimática , Humanos , Quinase I-kappa B , Isoenzimas/efeitos dos fármacos , Isoenzimas/metabolismo , Proteínas de Membrana , Inibidor de NF-kappaB alfa , NF-kappa B/efeitos dos fármacos , Fosforilação , Regiões Promotoras Genéticas/efeitos dos fármacos , Regiões Promotoras Genéticas/genética , Prostaglandina-Endoperóxido Sintases/efeitos dos fármacos , Prostaglandina-Endoperóxido Sintases/metabolismo , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Acetato de Tetradecanoilforbol/farmacologia , Transcrição Gênica/efeitos dos fármacos , Fator de Necrose Tumoral alfa/efeitos dos fármacosRESUMO
TNF-alpha induced a dose- and time-dependent increase in cyclooxygenase-2 (COX-2) expression and PGE2 formation in human NCI-H292 epithelial cells. Immunofluorescence staining demonstrated that COX-2 was expressed in cytosol and nuclear envelope. Tyrosine kinase inhibitors (genistein or herbimycin) or phosphoinositide-specific phospholipase C inhibitor (U73122) blocked TNF-alpha-induced COX-2 expression. TNF-alpha also stimulated phosphatidylinositol hydrolysis and protein kinase C (PKC) activity, and both were abolished by genistein or U73122. The PKC inhibitor, staurosporine, also inhibited TNF-alpha-induced response. The 12-O-tetradecanoylphorbol 13-acetate (TPA), a PKC activator, also stimulated COX-2 expression, this effect being inhibited by genistein or herbimycin. NF-kappaB DNA-protein binding and COX-2 promoter activity were enhanced by TNF-alpha, and these effects were inhibited by genistein, U73122, staurosporine, or pyrolidine dithiocarbamate. TPA stimulated both NF-kappaB DNA-protein binding and COX-2 promoter activity, these effects being inhibited by genistein, herbimycin, or pyrolidine dithiocarbamate. The TNF-alpha-induced, but not the TPA-induced, COX-2 promoter activity was inhibited by phospholipase C-gamma2 mutants, and the COX-2 promoter activity induced by either agent was attenuated by dominant-negative mutants of PKC-alpha, NF-kappaB-inducing kinase, or I-kappaB (inhibitory protein that dissociates from NF-kappaB) kinase (IKK)1 or 2. IKK activity was stimulated by both TNF-alpha and TPA, and these effects were inhibited by staurosporine or herbimycin. These results suggest that, in NCI-H292 epithelial cells, TNF-alpha might activate phospholipase C-gamma2 via an upstream tyrosine kinase to induce activation of PKC-alpha and protein tyrosine kinase, resulting in the activation of NF-kappaB-inducing kinase and IKK1/2, and NF-kappaB in the COX-2 promoter, then initiation of COX-2 expression and PGE2 release.
Assuntos
Células Epiteliais/enzimologia , Isoenzimas/biossíntese , Isoenzimas/fisiologia , Pulmão/enzimologia , Prostaglandina-Endoperóxido Sintases/biossíntese , Proteína Quinase C/fisiologia , Proteínas Tirosina Quinases/fisiologia , Transdução de Sinais/imunologia , Fator de Necrose Tumoral alfa/fisiologia , Fosfolipases Tipo C/fisiologia , Benzoquinonas , Núcleo Celular/efeitos dos fármacos , Núcleo Celular/metabolismo , Ciclo-Oxigenase 2 , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/genética , Ativação Enzimática/imunologia , Indução Enzimática/efeitos dos fármacos , Indução Enzimática/imunologia , Inibidores Enzimáticos/farmacologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Estrenos/farmacologia , Regulação da Expressão Gênica/imunologia , Genisteína/farmacologia , Humanos , Quinase I-kappa B , Isoenzimas/antagonistas & inibidores , Isoenzimas/genética , Isoenzimas/metabolismo , Lactamas Macrocíclicas , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Proteínas de Membrana , Mutagênese Sítio-Dirigida , NF-kappa B/antagonistas & inibidores , NF-kappa B/biossíntese , Fosfatidilinositol Diacilglicerol-Liase , Fosfolipase C gama , Regiões Promotoras Genéticas/imunologia , Prostaglandina-Endoperóxido Sintases/genética , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/metabolismo , Proteína Quinase C-alfa , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/biossíntese , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/fisiologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Pirrolidinas/farmacologia , Pirrolidinonas/farmacologia , Quinonas/farmacologia , Rifabutina/análogos & derivados , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Estaurosporina/farmacologia , Acetato de Tetradecanoilforbol/farmacologia , Tiocarbamatos/farmacologiaRESUMO
The signaling pathway for lipopolysaccharide (LPS)-induced nitric oxide (NO) release in RAW 264.7 macrophages involves the protein kinase C and p38 activation pathways (Chen, C. C., Wang, J. K., and Lin, S. B. (1998) J. Immunol. 161, 6206-6214; Chen, C. C., and Wang, J. K. (1999) Mol. Pharmacol. 55, 481-488). In this study, the role of the cAMP-dependent protein kinase A (PKA) pathway was investigated. The PKA inhibitors, KT-5720 and H8, reduced LPS-induced NO release and inducible nitric oxide synthase (iNOS) expression. The direct PKA activator, Bt(2)cAMP, caused concentration-dependent NO release and iNOS expression, as confirmed by immunofluorescence studies. The intracellular cAMP concentration did not increase until after 6 h of LPS treatment. Two cAMP-elevating agents, forskolin and cholera toxin, potentiated the LPS-induced NO release and iNOS expression. Stimulation of cells with LPS or Bt(2)cAMP for periods of 10 min to 24 h caused nuclear factor-kappaB (NF-kappaB) activation in the nuclei, as shown by detection of NF-kappaB-specific DNA-protein binding. The PKA inhibitor, H8, inhibited the NF-kappaB activation induced by 6- or 12-h treatment with LPS but not that induced after 1, 3, or 24 h. The cyclooxygenase-2 (COX-2) inhibitors, NS-398 and indomethacin, attenuated LPS-induced NO release, iNOS expression, and NF-kappaB DNA-protein complex formation. LPS induced COX-2 expression in a time-dependent manner, and prostaglandin E(2) production was induced in parallel. These results suggest that 6 h of treatment with LPS increases intracellular cAMP levels via COX-2 induction and prostaglandin E(2) production, resulting in PKA activation, NF-kappaB activation, iNOS expression, and NO production.