Comparison of Incidence of Hyponatremia between Linezolid and Vancomycin by Propensity Score Matching Analysis.

Several cases of severe hyponatremia induced by linezolid (LZD) were reported. However, severe infections could also cause hyponatremia by increasing vasopressin secretion. To prove that hyponatremia is associated with LZD rather than infection, we compared the incidence and risk of developing hyponatremia between patients receiving LZD and those receiving vancomycin (VCM). A retrospective, single-center, observational cohort study was conducted in patients aged 18 years or older who received intravenous LZD or VCM for 7 d or longer. Hyponatremia was defined as serum sodium level lower than 134 mEq/L and more than 5% decrease from baseline after treatment initiation. The incidence and risk of developing hyponatremia were analyzed between LZD and VCM groups using chi-square test. Four hundred and fifty patients who satisfied the selection criteria were divided into LZD (n = 97) and VCM groups (n = 353). Significant differences in patient characteristics between LZD and VCM groups were observed before propensity score matching, but no significant differences were found after matching. LZD group showed a significantly higher incidence and risk of developing hyponatremia compared to VCM group both before (LZD: 16.5%, VCM: 5.4%; p < 0.001, odds ratio 3.472 [95% confidence interval (CI) 1.711-7.048]) and after (LZD: 17.8%, VCM: 5.5%; p = 0.020, odds ratio 3.738 [95% CI 1.157-12.076]) propensity score matching. In conclusion, propensity score analyses suggest that the risk of hyponatremia associated with LZD is approximately 3.7-fold higher than that associated with VCM, regardless of patient background.

Hepatocyte growth factor ameliorates dextran sodium sulfate­induced colitis in a mouse model by altering the phenotype of intestinal macrophages.

Hepatocyte growth factor (HGF) serves key roles in cell motility, proliferation and immunoregulatory functions. However, the effect of HGF on macrophages is unclear. The present study aimed to elucidate the effect of HGF on the phenotypic alterations of intestinal lamina propria mononuclear cells (LPMCs). Colitis was induced in a mouse model using dextran sodium sulfate (DSS). Subsequently, LPMCs were isolated from the mice with chronic colitis and the expression levels of cytokine­encoding genes in the LPMCs were determined. CD11b­positive macrophages isolated from LPMCs were cultured with HGF, and alterations in the levels of M1 or M2 markers were evaluated by reverse transcription­quantitative polymerase chain reaction (RT­qPCR) and flow cytometry. In addition, the cytokine levels were assessed using RT­qPCR and ELISA. HGF shifted the phenotype of macrophages from M1 to M2­like, as determined by increased mRNA expression levels of arginase­1, CD206 and IL­10, and reduced mRNA expression levels of CD86 and IL­6 in mice with DSS­induced colitis. Moreover, HGF could ameliorate DSS­induced colitis owing to its immunosuppressive effect on immune cells. These findings indicated that HGF treatment may not only promote the regeneration of epithelial cells but also lead to tissue repair by phenotypic alteration of M1 macrophages to M2­like macrophages.

Increased Gene Copy Number of DEFA1A3 Is Associated With the Severity of Ulcerative Colitis.

INTRODUCTION: DEFA1A3 encodes human neutrophil peptides (HNPs) 1-3 and has multiple copy number variations (CNVs). HNPs are associated with innate immunity. Ulcerative colitis (UC), a chronic inflammatory gastrointestinal disorder, is a life-threatening condition, and predictive markers of UC severity are needed. This study investigated the relationship between DEFA1A3 CNV and UC severity. METHODS: This study enrolled 165 patients with UC. The relationship between DEFA1A3 CNV and disease severity was analyzed based on Mayo score, patient characteristics, and treatment methods. In addition, serum and stimulated neutrophil-derived HNP concentrations were also measured in patients with high and low DEFA1A3 CNV. RESULTS: DEFA1A3 CNV was significantly correlated with Mayo score and white blood cell count (R = 0.46, P < 0.0001; R = 0.29, P = 0.003, respectively), and only high copy numbers of DEFA1A3 were independent factors for severe UC (P < 0.001, odds ratio: 1.88, 95% confidence interval, 1.34-2.61). The number of severe UC patients with high DEFA1A3 CNV was significantly greater than those with low CNV. We confirmed the associations between DEFA1A3 and UC severity using a validation cohort. In addition, the HNP concentration in high-copy number patients was significantly higher after neutrophil stimulation than that in low-copy number patients. DISCUSSION: This study demonstrated that there is a correlation between DEFA1A3 copy number and severity in patients with UC. In addition, neutrophils from UC patients with higher DEFA1A3 CNV had high reactivity of secretion of HNPs after stimulation. DEFA1A3 CNV may be a novel severity marker and a potential therapeutic target for UC.

Covering Post-Endoscopic Submucosal Dissection Ulcers in Miniature Swine with Hexanoyl (Hx:C6) Group-Modified Alkaline-Treated Gelatin Porous Film (HAG) Induces Proper Healing by Decreasing Inflammation and Fibrosis.

BACKGROUND AND AIMS: Hexanoyl (Hx:C6) group-modified alkaline-treated gelatin porous film (HAG) is a newly developed degradable hydrogel characterized by strong adhesiveness and high affinity for vascular endothelial growth factor (VEGF). The aim of this study was to clarify the effect of HAG sheets on the healing process of post-endoscopic submucosal dissection (ESD) porcine gastric artificial ulcers. METHODS: (1) To evaluate the adhesiveness of HAG sheets over time, we performed ESD to create 1 artificial ulcer and covered the lesion with 1 HAG sheet using 1 miniature swine. We observed 2 ulcers by endoscopic and microscopic examinations. (2) To examine the effect of HAG sheets on post-ESD ulcer healing, we performed ESD using 5 miniature swine. The artificial ulcers were covered with HAG sheets, or left uncovered after ESD (day 0), followed by macroscopic and microscopic examinations. On days 7 and 14, we observed 2 ulcers by endoscopic examinations. On day 14, the animals were sacrificed, and histological examination was performed on the 3 stomachs that could be extirpated. RESULTS: (1) On day 7, adhesion of HAG sheets was observed. (2) Gastric ulcer area on day 7 was significantly larger in the covered ulcers than in the non-covered ulcers (p = 0.046). On day 14, although there was no significant difference in ulcer area irrespective of covering (p = 0.357), the covered ulcers tended to repair less fold convergence than non-covered ulcers. The covered ulcer sheets significantly decreased inflammatory cell infiltration (p = 0.011), but significantly increased the abundance of macrophages (p = 0.033), in submucosal layers. Also, the abundance of alpha-smooth muscle actin-positive cells in submucosal layers of the covered ulcers was significantly reduced (p = 0.044), leading to a decrease in collagen accumulation. In addition, fibrosis and atrophy of the muscularis propria were significantly lower for covered ulcers than for non-covered ulcers. Furthermore, microvessels and VEGF-positive cells were significantly more abundant in the submucosal layers of the covered ulcers (p < 0.001 and p = 0.024, respectively). CONCLUSIONS: HAG sheets induced post-ESD ulcer healing with less submucosal inflammation and muscularis propria injury and have the potential to decrease excess scarring.

A retrospective test for a possible relationship between linezolid-induced thrombocytopenia and hyponatraemia.

WHAT IS KNOWN AND OBJECTIVE: Thrombocytopenia is one of the typical adverse events caused by linezolid (LZD). Recently, some cases of severe hyponatraemia occurring while receiving LZD have been reported. This study investigated a possible relationship between LZD-induced hyponatraemia and thrombocytopenia and identified the risk factors for hyponatraemia and/or thrombocytopenia. METHODS: In this retrospective, single-centre, observational cohort study, 63 hospitalized patients aged over 18 years who received intravenous injection of LZD for more than seven consecutive days in Oita University Hospital between April 2015 and March 2018 were analysed. RESULTS: Thrombocytopenia occurred in 25 (39.7%) patients and hyponatraemia in 11 (17.5%) patients. Seven of 11 patients with hyponatraemia had concurrent thrombocytopenia. Although both serum sodium level and platelet count declined in most patients who developed hyponatraemia, no significant association between thrombocytopenia and hyponatraemia was found. Creatinine clearance level (Ccr) was significantly lower not only in the thrombocytopenia (vs no-thrombocytopenia) but also in the hyponatraemia group (vs no-hyponatraemia group). Univariate and multivariate logistic regression analyses identified different risk factors for thrombocytopenia and/or hyponatraemia (thrombocytopenia: Ccr and administration period; hyponatraemia: serum albumin; thrombocytopenia and hyponatraemia: administration period and serum albumin). WHAT IS NEW AND CONCLUSION: In conclusion, this study found no significant relationship between LZD-induced thrombocytopenia and hyponatraemia and identified some possible risk factors associated with onset of the two adverse events. These require further validation.

Oral administration of Lactobacillus plantarum 06CC2 prevents experimental colitis in mice via an anti­inflammatory response.

Dysbiosis of the enteric microbiota causes gastrointestinal diseases, including colitis. The present study investigated the beneficial effect of Lactobacillus plantarum 06CC2 in experimental colitis in mice. An experimental colitis model in C57BL6 mice was induced using dextran sulfate sodium. Mice were orally administered 06CC2 (06CC2 group) or PBS only (control group) by gavage. The disease activity index (DAI), histological grading, and colon tissue and colonic lamina propria mononuclear cells (LPMCs) were examined macroscopically and histopathologically, and the expression levels of inflammation­associated cytokines (IL­6, IL­12, TNF­α and IL­10) in these samples were determined. Compared with the control group, the 06CC2 group exhibited a significantly lower DAI (1.5±0.8 vs. 0.2±0.3, respectively; P<0.05) and pathology score (6.3±1.5 vs. 3.8±1.3, respectively; P<0.05). IL­10 expression in colonic LPMCs was higher in the 06CC2 group than in the control group, although there was no significant difference in IFN­Î³, IL­6 or IL­12 expression in colonic LPMCs between the two groups. In addition, 06CC2 stimulated the production of IL­10 from CD11b­positive cells and CD11c­positive cells in the colon. The 06CC2 strain induced IL­10 production in the colon and attenuated colon inflammation.

A high­fructose diet induces epithelial barrier dysfunction and exacerbates the severity of dextran sulfate sodium­induced colitis.

Excessive fructose intake is a risk factor for gut symptoms in patients with inflammatory bowel disease, however, its effect on the intestinal tract has not been evaluated previously. The present study investigated the impact of a high­fructose diet (HFD) on intestinal barrier function in mice with experimental colitis. C57/BL6 mice were provided with either a HFD or control diet and either plain drinking water or water containing 1% dextran sulfate sodium (DSS) for 2 weeks. The disease activity index (DAI), pathological scores and expression of inflammatory cytokines were compared among the groups, and the proportions of fecal bacteria in the colon were analyzed. The body weight and colon length were significantly decreased, and the DAI and pathological scores were significantly increased in the DSS/HFD­treated mice compared with the non­DSS­treated and control diet mice. Regarding the expression of inflammatory cytokines, the levels of interleukin (IL)­6, IL­1ß and tumor necrosis factor­α were significantly increased, and the expression of the tight junction protein occludin was significantly decreased in the DSS/HFD­treated mice. The total bacterial count was increased in the HFD mice. Taken together, these results indicate that an HFD resulted in the deterioration of intestinal barrier function and increased susceptibility to DSS­induced colitis.

The utility of apoptosis inhibitor of macrophages as a possible diagnostic marker in patients with Crohn's disease.

BACKGROUND: Apoptosis inhibitor of macrophages (AIM) was initially identified as an apoptosis inhibitor that supports the survival of macrophages against various apoptosis-inducing stimuli, and AIM produced by macrophages may contribute to the pathogenesis of inflammatory bowel diseases (IBDs). However, there have been no reports on the kinetics of AIM in IBD and the impact of AIM on the pathogenesis of IBD. In this study, we aimed to investigate the diagnostic utility of levels of AIM and their correlation with the activity of Crohn's disease (CD) and IBD. METHODS: We used an enzyme-linked immunosorbent assay (ELISA) to examine AIM serum levels in 16 healthy subjects and 90 patients with inflammatory bowel diseases, namely 39 with CD and 51 with ulcerative colitis (UC), as well as 17 patients with Behcet's disease (BD) as intestinal disease controls. We compared serum AIM levels among groups and examined whether there were correlations between serum AIM levels and disease activity and type. We also performed immunohistochemical staining of AIM in intestinal tissues of patients with CD. RESULTS: Serum AIM levels were significantly higher in patients with CD than in patients with UC, BD, and controls (3.27 ± 2.14, 1.88 ± 1.43, 2.34 ± 1.37, and 2.13 ± 0.64 µg/ml, respectively; P < 0.01). There was no difference in serum AIM levels before and after treatment in patients with CD. However, in these patients the diagnostic rate using AIM was better than that based on anti-Saccharomyces cerevisiae antibodies. AIM was expressed in macrophages that were positive for CD14, CD16, or both in the intestinal tissues of patients with CD. CONCLUSIONS: AIM is a novel biomarker of CD that can distinguish CD from UC or BD. It is suggested that AIM may contribute to intestinal inflammation by inhibiting the apoptosis of macrophages.

Fecal Human Neutrophil Peptide Levels Correlate with Intestinal Inflammation in Ulcerative Colitis.

BACKGROUND/AIM: Fecal markers have recently been found to provide convenient and noninvasive assessment of intestinal inflammation in inflammatory bowel disease (IBD). In this study, we examined the clinical significance of fecal human neutrophil peptides (F-HNP) in the evaluation of IBD disease activity. METHODS: This study enrolled 70 patients with IBD, consisting of 45 patients with ulcerative colitis (UC), 25 patients with Crohn's disease (CD), and 11 non-IBD controls. Stools samples were evaluated for the association between F-HNP concentration and disease and endoscopic activity in each group and the correlation between F-HNP and fecal calprotectin (F-CP) concentrations. RESULTS: Median F-HNP levels were as follows: UC: 25.6 ng/ml; CD: 20.1 ng/ml; and non-IBD controls: 4.9 ng/ml. F-HNP levels were significantly higher in each IBD group, especially in the UC group, than in the control group. In the UC group, both F-HNP and F-CP levels were significantly higher during active disease compared to the remission phase. Both markers were significantly correlated with the Mayo endoscopic score, although the correlation was stronger for F-HNP than for F-CP (r = 0.66 vs. r = 0.54). CONCLUSION: F-HNP is a noninvasive marker that is useful for evaluating UC endoscopic activity.

Glycoprotein Nonmetastatic Melanoma B (Gpnmb)-Positive Macrophages Contribute to the Balance between Fibrosis and Fibrolysis during the Repair of Acute Liver Injury in Mice.

BACKGROUND AND AIMS: Glycoprotein nonmetastatic melanoma B (Gpnmb), a transmembrane glycoprotein that is expressed in macrophages, negatively regulates inflammation. We have reported that Gpnmb is strongly expressed in the livers of rats fed a choline-deficient, L-amino acid-defined (CDAA) diet. However, the role of macrophage-expressed Gpnmb in liver injury is still unknown. This study aimed to clarify the characteristics of infiltrating macrophages that express Gpnmb, and the involvement of Gpnmb in the repair process in response to liver injury. METHODS: C57BL/6J, DBA/2J [DBA] and DBA/2J-Gpnmb+ [DBA-g+] mice were treated with a single intraperitoneal injection of carbon tetrachloride (CCl4) at a dose of 1.0 mL/kg body weight. Mice were sacrificed at predetermined time points, followed by measurement of serum alanine aminotransferase (ALT) levels and histological examination. Expression of Gpnmb, pro-/anti-inflammatory cytokines, and profibrotic/antifibrotic factors were examined by quantitative RT-PCR and/or Western blotting. Immunohistochemistry, fluorescent immunostaining and flow cytometry were used to determine the expression of Gpnmb, CD68, CD11b and α-SMA, phagocytic activity, and the presence of apoptotic bodies. We used quantitative RT-PCR and ELISA to examine TGF-ß and MMP-13 expression and the concentrations and supernatants of isolated infiltrating hepatic macrophages transfected with siGpnmb. RESULTS: In C57BL/6J mice, serum ALT levels increased at two days after CCl4 injection and decreased at four days. Gpnmb expression in the liver was stimulated four days after CCl4 injection. Histological examination and flow cytometry showed that Gpnmb-positive cells were almost positive for CD68-positive macrophages, contained engulfed apoptotic bodies and exhibited enhanced phagocytic activity. Isolated infiltrating hepatic macrophages transfected with siGpnmb showed high MMP-13 secretion. There was no significant difference in the magnitude of CCl4-induced liver injury between DBA-g+ and DBA mice. However, hepatic MMP-13 expression, as well as α-SMA expression and collagen production, increased significantly in DBA-g+ compared with DBA mice. CONCLUSIONS: Gpnmb-positive macrophages infiltrate the liver during the recovery phase of CCl4-induced acute liver injury and contribute to the balance between fibrosis and fibrolysis in the repair process following acute liver injury.

A retrospective analysis to estimate target trough concentration of vancomycin for febrile neutropenia in patients with hematological malignancy.

BACKGROUND: The target trough concentration of vancomycin in patients with febrile neutropenia has not been reported. The aim of this study was to estimate the target trough concentration for febrile neutropenia in patients with hematological malignancy. METHODS: In this retrospective, single-center, observational cohort study, 63 hospitalized patients with hematological malignancy who were treated with vancomycin for febrile neutropenia due to bacteriologically documented or presumptive Gram-positive infections were analyzed. RESULTS: A significant difference in the first trough concentration of vancomycin was observed between the response and non-response groups, and between the nephrotoxicity and non-nephrotoxicity groups. Multiple logistic regression analyses identified the first trough concentration as the only independent variable associated with clinical efficacy and nephrotoxicity of vancomycin. The areas under the ROC curves were 0.72 and 0.83 for clinical efficacy and nephrotoxicity, respectively. The cut-off values of the first trough concentration were 11.1 µg/ml for clinical efficacy (sensitivity 60%, specificity 87%) and 11.9 µg/ml for nephrotoxicity (sensitivity 77%, specificity 82%). CONCLUSIONS: These results suggest a relationship of trough vancomycin concentration with clinical efficacy and incidence of nephrotoxicity. We propose a target trough vancomycin concentration of around 11.5 µg/ml for febrile neutropenia in patients with hematological malignancy.