Invasion of enteric bacteria, such as Salmonella and invasive E. coli, into intestinal epithelial cells induces proinflammatory gene responses and finally epithelial cell apoptosis. In this study, we asked whether invasive bacterial infection of human intestinal epithelial cells could upregulate cyclooxygenase-2 (COX-2) gene expression and whether increased COX-2 expression could influence intestinal epithelial cell apoptosis. Expression of COX-2 mRNA and prostaglandin (PG) E production were upregulated in HT-29 colon epithelial cells which were infected with S. dublin or invasive E. coli, as examined by quantitative RT-PCR and radioimmunoassay. Inhibition of COX-2 expression and PGE2 production using NS-398, a specific COX-2 inhibitor, showed a significant increase af epithelial cell apoptosis and caspase-3 activation in HT-29 cells infected with invasive bacteria. However, the addition of valerylsalicylate, a specific COX-1 inhibitor, did not change apoptosis in S. dublin-infected HT-29 cells. These results suggest that upregulated COX-2 expression and PGE2 production in response to invasive bacterial infection could contribute to host defense by inhibiting apoptosis of intestinal epithelial cells.
Apoptosis* ; Bacteria ; Bacterial Infections* ; Caspase 3 ; Colon ; Cyclooxygenase 2 ; Dinoprostone ; Enterobacteriaceae ; Epithelial Cells* ; Gene Expression ; HT29 Cells ; Humans ; Prostaglandin-Endoperoxide Synthases* ; Radioimmunoassay ; RNA, Messenger ; Salmonella

No abstract available.
Colon* ; Polyps*

The present study was designed to estimate the seroprevalence of NLVs among diarrheagenic children and in healthy adults in Seoul and its vicinity with the use of an EIA and an Western blot (WB) based on recombinant Norwalk virus capsid protein (rNV) and crude virus preparations as antigen. Seroconversion was observed in 34 (83%) of 41 tested using the EIA and in 21 (54%) of 39 using the WB, suggesting that the NLVs with epitopes common to rNV are prevalent in Seoul area. Diarrheal children who were known to have been infected with several other strains of the NLVs showed no significant antibody response to the rNV. Infection with rNV occurred earlier in life: primary infections with rNV were common before the age of 6 months and over 91% of children had evidence of infection by that age by the EIA. Since the amount of the NLV antigens available for seroepidemiologic surveys is limited, we tried to detect NLV antibody by using crude virus preparations as antigen. One crude virus preparation of a child whose stool yielded genetically distinct NLV revealed the presence of the plural number of bands upon SDS-PAGE, but precipitated only one band (62 kDa) after the WB with a serum (collected 10 days after the onset of symptoms) of another diarrheal child. The WB assay we present in this report revealed that the NLVs are prevalent among Korean population and that the sera contained antibody to a single major structural protein, with molecular sizes of 58 to 62 kDa, compatible with the sizes reported for the Norwalk virus and Snow Mountain agent proteins, respectively. When the results of the WB were compared with those obtained by the EIA, the EIA antibody assay was sensitive enough to detect an antibody rise of as much as 4096-fold but not as specific as the WB. The WB assay presented in this paper will provide a powerful tool to elucidate not only antigenic structures of the NLVs but also seroepidemiology of the NLV infection. The availability of an unlimited source of antigen will enable a large scale serologic studies that will greatly increase our understanding of the role of NLVs in human enteric illness.
Adult ; Antibody Formation ; Blotting, Western ; Capsid Proteins ; Capsid* ; Child ; Electrophoresis, Polyacrylamide Gel ; Epitopes ; Humans ; Norovirus* ; Norwalk virus* ; Seoul* ; Seroepidemiologic Studies* ; Snow

No abstract available.

Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

Purpose: The purpose of this study is to develop the Theory of Uncertainty on COVID-19 using the strategy of theory derivation. Methods: Theory derivation was carried out in the following steps: review the literature to explore the phenomena related to uncertainty on COVID-19; select a parent theory that provides valuable concepts and a useful structure for derivation, and identify the concepts and structure of the parent theory to use in derivation; modify and redefine the concepts and structure of the parent theory to create a derived theory. In the literature review process, relevant findings were synthesized to support the propositions of the derived theory. Results: The Theory of Uncertainty on COVID-19 was derived from the Uncertainty in Illness Theory to make it relevant and applicable to a specific aspect of uncertainty on COVID-19, health-related uncertainty perceived by a person who has not contracted COVID-19. It is a middle-range theory targeting the general population and consists of a linear and unidirectional model centered on three themes: antecedents of uncertainty, appraisal of uncertainty, and coping with uncertainty. Conclusion The Theory of Uncertainty on COVID-19 will be able to contribute to efforts to manage perceived uncertainty on pandemic diseases and improve individual biopsychosocial health in the future.

No abstract available.
Lymphohistiocytosis, Hemophagocytic*