Amebic colitis in asymptomatic subjects with positive fecal occult blood test results: clinical features different from symptomatic cases

Amebiasis is a common parasitic infectious disease in developing countries. In developed countries, it is occasionally encountered in travelers to the tropics and in homosexual males. During the past eight years, we detected four cases of amebic colitis among 5,193 subjects who underwent colonoscopy because of positive fecal occult blood test results in a mass screening. All four cases did not have any abdominal symptoms. Ulcerative lesions were observed only in the cecum and ascending colon; another portion of the colon and rectum appeared normal. We may encounter amebic colitis during colonoscopic examination even in subjects who are asymptomatic.     

Canagliflozin Prevents Diabetes-Induced Vascular Dysfunction in ApoE-Deficient Mice

Aim: Recent studies have demonstrated that selective sodium–glucose cotransporter 2 inhibitors (SGLT2is) reduce cardiovascular events, although their mechanism remains obscure. We examined the effect of canagliflozin, an SGLT2i, on atherogenesis and investigated its underlying mechanism.Method: Canagliflozin (30 mg/kg/day) was administered by gavage to streptozotocin-induced diabetic apolipoprotein E-deficient (ApoE^−/−) mice. Sudan IV staining was performed at the aortic arch. Immunostaining, quantitative RT-PCR, and vascular reactivity assay were performed using the aorta. In vitro experiments using human umbilical vein endothelial cells (HUVECs) were also performed.Result: Canagliflozin decreased blood glucose (P < 0.001) and total cholesterol (P < 0.05) levels. Sudan IV staining showed that 12-week canagliflozin treatment decreased atherosclerotic lesions (P < 0.05). Further, 8-week canagliflozin treatment ameliorated endothelial dysfunction, as determined by acetylcholine-induced vasodilation (P < 0.05), and significantly reduced the expressions of inflammatory molecules such as ICAM-1 and VCAM-1 in the aorta at the RNA and protein levels. Canagliflozin also reduced the expressions of NADPH oxidase subunits such as NOX2 and p22phox in the aorta and reduced urinary excretion of 8-OHdG, suggesting a reduction in oxidative stress. Methylglyoxal, a precursor of advanced glycation end products, increased the expressions of ICAM-1 and p22phox in HUVECs (P < 0.05, both). Methylglyoxal also decreased the phosphorylation of eNOS^Ser1177 and Akt but increased the phosphorylation of eNOS^Thr495 and p38 MAPK in HUVECs.Conclusion: Canagliflozin prevents endothelial dysfunction and atherogenesis in diabetic ApoE^−/− mice. Anti-inflammatory and antioxidative potential due to reduced glucose toxicity to endothelial cells might be its underlying mechanisms.     

Histamine synthesis is required for granule maturation in murine mast cells

Mast cells are the major sources of histamine, which is released in response to immunological stimulations. The synthesis of histamine is catalyzed by histidine decarboxylase (HDC). Previous studies have shown that Hdc^?/? mast cells exhibit aberrant granule morphology with severely decreased granule content. Here, we investigated whether the histamine synthesized in mast cells regulates the granule maturation of murine mast cells. Several genes, including those encoding granule proteases and enzymes involved in heparin biosynthesis, were downregulated in Hdc^?/? peritoneal mast cells. Impaired granule maturation was also found in Hdc^?/? BM‐derived cultured mast cells when they were cocultured with fibroblasts in the presence of c‐kit ligand. Exogenous application of histamine and several H₄ receptor agonists restored the granule maturation of Hdc^?/? cultured mast cells. However, the maturation of granules was largely normal in Hrh4^?/? peritoneal mast cells. Depletion of cellular histamine with tetrabenazine, an inhibitor of vesicular monoamine transporter‐2, did not affect granule maturation. In vivo experiments with mast cell deficient Kit^W/Kit^W‐v mice indicated that the expression of the Hdc gene in mast cells is required for granule maturation. These results suggest that histamine promotes granule maturation in mast cells and acts as an proinflammatory mediator.     

A case of bleeding duodenal ulcer with pemphigus vulgaris during steroid therapy

We report a rare case of bleeding duodenal ulceration in the different form of pemphigus vulgaris (PV). A 52-year-old female was diagnosed with acute pharyngitis and administered methylprednisolone. After several days, melena and many blisters were noted on her body. Endoscopy revealed blood oozing from the second part of a duodeneal ulcer around the major duodenal papilla. After initial endoscopic hemostasis, we observed a large regional, shallow duodenal ulcer. The blisters were suspected to represent the Nikolsky’s sign. The histological findings of her skin were characterized by suprabasal acantholysis and mixed inflammatory cell infiltrates, including scattered eosinophils. There were no other significant findings on skin biopsy or by direct immunofluorescence. Enzyme-linked immunosorbent assay showed an elevated titer of anti-desmoglein 3 autoantibodies in her serum, and the patient was finally diagnosed with mucosal-dominant PV. Although we performed multiple biopsies from the esophagus, stomach and duodenum, the samples did not contain significant findings to enable us to distinguish from pemphigus vulgaris. Corticosteroids remain an essential component of PV treatment. When clinicians encounter PV development during steroid therapy, upper gastrointestinal complications should be considered and diagnostic endoscopy conducted.     

Terminal-Restriction Fragment Length Polymorphism (T-RFLP) Analysis for Changes in the Gut Microbiota Profiles of Indomethacin- and Rebamipide-Treated Mice

Background/Aims: We investigated the effects of indomethacin and rebamipide on the gut microbiota profiles using terminal restriction fragment polymorphism (T-RFLP) analysis. Materials and Methods: Female C57BL/6J mice were given indomethacin (10 mg/kg, s.c.) once a day and 2.5 mg rebamipide orally 3 times a day. After 7 days, they were sacrificed, and luminal contents were obtained from the ileum and cecum. The gut microbiota communities were analyzed by T-RFLP analysis with BslI digestion. Results: T-RFLP analyses showed that rebamipide and indomethacin had no significant effects on the gut microbiota profiles in the ileum and cecum. In contrast, the combination of rebamipide + indomethacin induced a significant change in the gut microbiota. The changes in the microbiota composition induced by the combination of rebamipide + indomethacin were characterized by the increase in the orders Bifidobacteriales and Lactobacillales, the genera Bacteroides and Prevotella and the family Clostridiaceae. The diversity of the gut microbiota community generated by the combination of rebamipide + indomethacin was significantly higher than those induced by either rebamipide or indomethacin alone. Conclusion: The combination of rebamipide + indomethacin induces remarkable changes in the gut microbiota composition and diversity. The clinical activity of rebamipide on nonsteroidal anti-inflammatory drug-induced intestinal injury may be exerted through a modulation of the gut microbiota.     

Diabetes and life expectancy among Japanese - NIPPON DATA80

Life expectancy (LE) among the Japanese population with or without diabetes mellitus was estimated. LE in 40-year old men and women was 41.1 and 47.5 years in those without diabetes and 32.3 and 40.9 years in those with diabetes. The LE of 40-year old men and women with diabetes was 8.8 and 6.6 years shorter than in those without diabetes. Diabetes mellitus leads to a decrease in LE. The presence of impaired glucose tolerance also affected LE inversely.     

Insufflation of Hydrogen Gas Restrains the Inflammatory Response of Cardiopulmonary Bypass in a Rat Model

Systemic inflammatory responses in patients receiving cardiac surgery with the use of the cardiopulmonary bypass (CPB) significantly contribute to CPB‐associated morbidity and mortality. We hypothesized that insufflated hydrogen gas (H₂) would provide systemic anti‐inflammatory and anti‐apoptotic effects during CPB, therefore reducing proinflammatory cytokine levels. In this study, we examined the protective effect of H₂ on a rat CPB model. Rats were divided into three groups: the sham operation (SHAM) group, received sternotomy only; the CPB group, which was initiated and maintained for 60 min; and the CPB + H₂ group in which H₂ was given via an oxygenator during CPB for 60 min. We collected blood samples before, 20 min, and 60 min after the initiation of CPB. We measured the serum cytokine levels of (tumor necrosis factor‐α, interleukin‐6, and interleukin‐10) and biochemical markers (lactate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase). We also measured the wet‐to‐dry weight (W/D) ratio of the left lung 60 min after the initiation of CPB. In the CPB group, the cytokine and biochemical marker levels significantly increased 20 min after the CPB initiation and further increased 60 min after the CPB initiation as compared with the SHAM group. In the CPB + H₂ group, however, such increases were significantly suppressed at 60 min after the CPB initiation. Although the W/D ratio in the CPB group significantly increased as compared with that in the SHAM group, such an increase was also suppressed significantly in the CPB + H₂ group. We suggest that H₂ insufflation is a possible new potential therapy for counteracting CPB‐induced systemic inflammation.