155 research outputs found
Detection of the Onset of the Epidemic Period of Respiratory Syncytial Virus Infection in Japan
Respiratory syncytial virus (RSV) is a leading cause of lower respiratory tract infection in young children worldwide. An annual epidemic of RSV infection generally begins around autumn, reaching a peak at the end of year in Japan, but in 2017 it started in early July and peaked in September. As the onset timing of RSV season varies, it is important to detect the beginning of an epidemic, to enable the implementation of preventive measures. However, there are currently no specified criteria or methods to determine the onset of RSV season in a timely manner. Therefore, we developed a model to detect the epidemic onset, based on data from the Infectious Diseases Weekly Report from 2012 to 2017. The 47 prefectures of Japan span 11 climate zones, which affect the timing of epidemic onset. Therefore, the onset of RSV season was assessed separately in each prefecture. Non-linear regression analysis was performed to generate a mathematical model of the annual epidemic cycle for each prefecture. A search index was used to determine the onset of RSV season, which was estimated using the number of RSV reports per week within an epidemic period (RSV-reports/w) and the number of reported cases included within an epidemic period relative to the total number of RSV reports (capture rate). A number of RSV-reports/w, which was used as a threshold (a number at onset line) to determine the condition of the onset of RSV season, was then estimated based on the search index. The mean number at the onset of RSV season for 47 prefectures was 29.7 reports/week (median 21.0, range 6.0–121.0 reports/ week). The model also showed that the onset of RSV season in 2017 was more than 1 month earlier than the previous year. In conclusion, the model detected epidemic cycles and their onset conditions in all prefectures, despite the 11 climate zones of Japan. The results are expected to contribute to infant medical care by allowing medical personnel to take preventive measures promptly at the beginning of the epidemic RSV season
Bile Acids Induce Cdx2 Expression Through the Farnesoid X Receptor in Gastric Epithelial Cells
Clinical and experimental studies showed that the reflux of bile into the stomach contributes to the induction of intestinal metaplasia of the stomach and gastric carcinogenesis. Caudal-type homeobox 2 (Cdx2) plays a key role in the exhibition of intestinal phenotypes by regulating the expression of intestine-specific genes such as goblet-specific gene mucin 2 (MUC2). We investigated the involvement of the farnesoid X receptor (FXR), a nuclear receptor for bile acids, in the chenodeoxycholic acid (CDCA)-induced expression of Cdx2 and MUC2 in normal rat gastric epithelial cells (RGM-1 cells). RGM-1 cells were treated with CDCA or GW4064, an FXR agonist, in the presence or absence of guggulsterone, an FXR antagonist. CDCA induced dose-dependent expression of Cdx2 and MUC2 at both the mRNA and protein levels. The maximum stimulation of Cdx2 and MUC2 mRNA induced by CDCA was observed at 3 h and by 6 h, respectively. GW4064 also induced expression of these molecules. The effects of CDCA and GW4064 on expression of Cdx2 and MUC2 were abolished by guggulsterone. These findings suggest that bile acids may induce gastric intestinal metaplasia and carcinogenesis through the FXR
Lansoprazole, a Proton Pump Inhibitor, Suppresses Production of Tumor Necrosis Factor-α and Interleukin-1β Induced by Lipopolysaccharide and Helicobacter Pylori Bacterial Components in Human Monocytic Cells via Inhibition of Activation of Nuclear Factor-κB and Extracellular Signal-Regulated Kinase
Pathogenic bacterial components play critical roles in initiation of gastrointestinal inflammation via activation of intracellular signaling pathways which induce proinflammatory cytokines such as tumor necrosis factor (TNF)-α and interleukin (IL)-1β. Lansoprazole (LANSO), a proton pump inhibitor, has been widely used for the treatment of peptic ulcers and reflux esophagitis due to its potent acid-suppressive effect. It has also been reported to have anti-inflammatory effects. In this study we investigated the effects of LANSO on the production of TNF-α and IL-1β induced by lipopolysaccharide (LPS) and Helicobacter pylori water-soluble extract (HpWE) in the human monocytic cell line (THP-1). LANSO (100 µM) significantly reduced mRNA expression and production of TNF-α and IL-1β by THP-1 cells stimulated by LPS and HpWE. LANSO inhibited phosphorylation and degradation of inhibitory factor κB-α (IκB-α) and phosphorylation of extracellular signal-regulated kinase (ERK) induced by LPS and HpWE in THP-1 cells. These findings suggest that LANSO exerts anti-inflammatory effects by suppressing induction of TNF-α and IL-1β via inhibition of nuclear factor (NF)-κB and ERK activation
Mitochondrial disorders in NSAIDs-induced small bowel injury
Recent studies using small bowel endoscopy revealed that non-steroidal anti-inflammatory drugs including low-dose aspirin, can often induce small bowel injury. Non-steroidal anti-inflammatory drugs-induced small bowel mucosal injury involves various factors such as enterobacteria, cytokines, and bile. Experimental studies demonstrate that both mitochondrial disorders and inhibition of cyclooxygenases are required for development of non-steroidal anti-inflammatory drugs-induced small bowel injury. Mitochondrion is an organelle playing a central role in energy production in organisms. Many non-steroidal anti-inflammatory drugs directly cause mitochondrial disorders, which are attributable to uncoupling of oxidative phosphorylation induced by opening of the mega channel called mitochondrial permeability transition pore on the mitochondrial membrane by non-steroidal anti-inflammatory drugs. Bile acids and tumor necrosis factor-α also can open the permeability transition pore. The permeability transition pore opening induces the release of cytochrome c from mitochondrial matrix into the cytosol, which triggers a cascade of events that will lead to cell death. Therefore these mitochondrial disorders may cause disturbance of the mucosal barrier function and elevation of the small bowel permeability, and play particularly important roles in early processes of non-steroidal anti-inflammatory drugs-induced small bowel injury. Although no valid means of preventing or treating non-steroidal anti-inflammatory drugs-induced small bowel injury has been established, advances in mitochondrial studies may bring about innovation in the prevention and treatment of this kind of injury
Rebamipide, a mucoprotective drug, inhibits NSAIDs-induced gastric mucosal injury: possible involvement of the downregulation of 15-hydroxyprostaglandin dehydrogenase
Prostaglandin E2 plays an important role in the maintenance of gastric mucosal integrity. The level of biologically active prostaglandin E2 in the tissue is regulated by the balanced expression of its synthetic enzymes, such as cyclooxygenase, and its catabolic enzyme, 15-hydroxyprostaglandin dehydrogenase. We examined the effect of rebamipide, a mucoprotective drug, on prostaglandin E2 production and metabolism in the gastric tissue and its effect on indomethacin-induced gastric mucosal injury in mice. Rebamipide suppressed indomethacin-induced gastric mucosal injury. Suppressive effect of rebamipide on indomethacin-induced gastric mucosal injury was also observed in cyclooxygenase-2-knockout mice. The mice that were treated with rebamipide showed a 2-fold increase in cyclooxygenase-2 mRNA expression in the gastric tissue, whereas 15-hydroxyprostaglandin dehydrogenase mRNA expression markedly decreased as compared to vehicle-treated control mice. Rebamipide did not affect the expression of cyclooxygenase-1 in the gastric tissue. Rebamipide did not increase prostaglandin E2 production in the gastric tissue; however, it induced a 1.4-fold increase in the concentration of prostaglandin E2 in the gastric tissue as compared to vehicle-treated control mice. These results suggest that the suppressive effect of rebamipide on non-steroidal anti-inflammatory drugs-induced gastric mucosal injury can be attributed to reduced 15-hydroxyprostaglandin dehydrogenase expression, which increases the prostaglandin E2 concentration in the gastric tissue
レゾルシル酸ラクトンLL-Z1640-2の成人T細胞白血病/リンパ腫に対する治療効果
Adult T-cell leukaemia/lymphoma (ATL) remains incurable. The NF-κB and interferon regulatory factor 4 (IRF4) signalling pathways are among the critical survival pathways for the progression of ATL. TGF-β-activated kinase 1 (TAK1), an IκB kinase-activating kinase, triggers the activation of NF-κB. The resorcylic acid lactone LL-Z1640-2 is a potent irreversible inhibitor of TAK1/extracellular signal-regulated kinase 2 (ERK2). We herein examined the therapeutic efficacy of LL-Z1640-2 against ATL. LL-Z1640-2 effectively suppressed the in vivo growth of ATL cells. It induced in vitro apoptosis and inhibited the nuclear translocation of p65/RelA in ATL cells. The knockdown of IRF4 strongly induced ATL cell death while downregulating MYC. LL-Z1640-2 as well as the NF-κB inhibitor BAY11-7082 decreased the expression of IRF4 and MYC at the protein and mRNA levels, indicating the suppression of the NF-κB-IRF4-MYC axis. The treatment with LL-Z1640-2 also mitigated the phosphorylation of p38 MAPK along with the expression of CC chemokine receptor 4. Furthermore, the inhibition of STAT3/5 potentiated the cytotoxic activity of LL-Z1640-2 against IL-2-responsive ATL cells in the presence of IL-2. Therefore, LL-Z1640-2 appears to be an effective treatment for ATL. Further studies are needed to develop more potent compounds that retain the active motifs of LL-Z1640-2
Long‐term prospective pilot study with tranilast for the prevention of stricture progression in patients with Crohn's disease
Pre-illness isoflavone consumption and disease risk of ulcerative colitis: a multicenter case-control study in Japan.
Previous studies have suggested that estrogens play a role in the development of ulcerative colitis (UC). Because isoflavones have a similar structure to 17β-estradiol, dietary consumption of isoflavones may have similar influences on the development of UC. We examined the association between pre-illness isoflavone consumption and the risk of UC.We conducted a hospital-based case control study, and compared the dietary habits of 126 newly diagnosed UC cases with those of 170 age- and gender-matched hospital controls. Information on dietary factors was collected using a self-administered diet history questionnaire. To consider potential changes in dietary habits due to disease symptoms, the habits were assessed separately during the previous 1 month and at 1 year before the recruitment.In the assessment of dietary habits during the previous 1 month, the highest tertile of isoflavone consumption revealed an increased odds ratio (OR) for UC (OR = 2.79; 95% confidence interval (CI), 1.39-5.59; Trend P = 0.004). A significant association was also observed for the dietary assessment at 1 year before, when most UC cases had not yet experienced their first disease symptoms (OR = 2.06; 95% CI, 1.05-4.04; Trend P = 0.04). Associations were more pronounced in females (OR in highest tertile of isoflavone consumption at 1 year before = 4.76; 95% CI, 1.30-17.5; Trend P = 0.02) but were obscured in males (corresponding OR = 1.21; 95% CI, 0.49-3.01; Trend P = 0.63).Dietary isoflavone consumption may be associated with an increased risk of UC, particularly in females. Prospective cohort studies are warranted to confirm these findings
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