Contribution of the human cytochrome P450 2C subfamily to the metabolism of and the interactions with endogenous compounds including steroid hormones.

The objectives of this study were as follows: 1) to compare the metabolic activities of endogenous compounds and their effects on dopamine formation and hydroxylation of steroid hormones, mediated by human cytochrome P450 (CYP), including CYP2C9.1 and CYP2C19, as well as the variants CYP2C9.2 (Arg144Cys) and CYP2C9.3 (Ile359Leu); and 2) to assess the effects of steroid hormones on the activities of CYP2C9.1, CYP2C9.2, and CYP2C19 to estimate the contribution of the CYP2C subfamily to metabolism and drug-drug interactions of endogenous compounds. Dopamine formation from p -tyramine and 6ß- and 21- (for progesterone) hydroxylation of testosterone, cortisol, and progesterone by CYP2C9 variants, CYP2C19, CYP2D6, and CYP3A4 were determined using HPLC. The effects of steroid hormones such as testosterone, cortisol, and progesterone on tolbutamide methyl hydroxylation mediated by CYP2C subfamily members were investigated. Only CYP2D6 catalyzed dopamine formation. The 6ß-hydroxylation activities of testosterone, cortisol, and progesterone catalyzed by CYP2C9 variants and CYP2D6 were less than 5% of those by CYP3A4. Although cortisol did not inhibit tolbutamide methyl hydroxylation catalyzed by CYP2C9.1, CYP2C9.2, or CYP2C19 and testosterone did not inhibit CYP2C19 activity, the reactions catalyzed by CY2C9.1 and CYP2C9.2 were inhibited by testosterone. The inhibition of progesterone by CYP2C19 was stronger than that by CYP2C9.1 and CYP2C9.2. CYP2C9.1 and CYP2C19 noncompetitively and competitively inhibited tolbutamide methyl hydroxylation with inhibition constants of 43.2 µM and 1.03 µM, respectively. Clinical interactions among endogenous compounds would vary within the CYP2C subfamily, although the contribution of the CYP2C subfamily may be of minor importance for dopamine formation and the detoxification (6ß-hydroxylation) of endogenous steroid hormones.

Effect of therapeutic plasma exchange on phenytoin plasma concentration in patients receiving intravenous fosphenytoin therapy.

We report for patients with encephalitis treated with plasma exchange (PE) and fosphenytoin. In patient 1, phenytoin levels decreased on the maintenance dose, and the phenytoin concentration was <10 µg/mL on day 12 of administration. In patient 2, the phenytoin levels was <10 µg/mL on day 4. Increasing the fosphenytoin dose pushed the phenytoin level into therapeutic range. There were no differences between the areas under the concentration-time curve of phenytoin with and without PE. We previously reported a decline in phenytoin levels after prolonged use of fosphenytoin. Therefore, dose adjustment of fosphenytoin in patients undergoing PE may be unnecessary.

Pyogenic spondylitis with acute course caused by Corynebacterium simulans.

Corynebacterium simulans was first reported in 2000. Although it is a member of the normal skin flora, some cases of C. simulans infection have been reported. Other Corynebacterium spp. rarely cause chronic pyogenic spondylitis, and pyogenic spondylitis caused by C. simulans has not been reported at all. Here we report a case of acute pyogenic spondylitis due to C. simulans. A 78-year-old man with diabetes mellitus visited our hospital with a 3-day history of lower back pain and fever. Blood culture revealed C. simulans and magnetic resonance images of lumbar vertebrae showed pyogenic spondylitis. He recovered after treatment by vancomycin for 9 weeks and was discharged home. No recurrence has been observed for half a year. This is likely the first reported case of pyogenic spondylitis by C. simulans. In general, Corynebacterium spp. cause chronic pyogenic spondylitis, but this case showed an acute course.

Risk factors for decreased teicoplanin trough concentrations during initial dosing in critically ill patients.

Aim of the study: Here, we investigated the risk factors for decreased teicoplanin plasma trough concentrations relative to the initial dosing in critically ill patients. Patients and methods: Data obtained from 80 eligible critically ill patients who received intravenous teicoplanin were retrospectively analyzed. Risk factors for decreases in teicoplanin trough concentrations 72 h after administration of teicoplanin of more than 30% relative to predicted concentrations based on initial dosing setting were identified by logistic regression analysis. Results: Although prediction trough concentration and total dose of two days no significant differences were seen between the variation group and the non-variation group, actual trough concentration was significantly different between two groups (19.9±5.6 µg/ml vs 10.3±2.2 µg/ml, p < 0.001). In multivariate analysis, serum albumin ≤ 2.2 mg/dl (odds ratio [OR] = 3.003, 95% CI 1.072-8.408; p = 0.036) and SOFA score ≥ 9 (OR = 3.498, 95% CI 1.171-10.450; p = 0.025) were significant risk factors for decreased teicoplanin plasma trough concentrations. Conclusion: In critically ill patients, high SOFA score and low serum albumin were risk factors for decreased teicoplanin plasma trough concentration during initial dosing.

Translocator protein 18kDa antagonist ameliorates stress-induced stool abnormality and abdominal pain in rodent stress models.

BACKGROUND: Irritable bowel syndrome (IBS) is a functional gastrointestinal (GI) disorder characterized by abdominal pain and abnormal bowel habits, both of which are exacerbated by psychological stress. The translocator protein 18kDa (TSPO) is a marker of reactive gliosis in a number of central nervous system (CNS) diseases and responsible for many cellular functions, including neurosteroidogenesis. Although it has been reported that psychological stress disturbs neurosteroids levels, the pathophysiological relevance of TSPO in IBS is poorly understood. METHODS: We examined the effects of a TSPO antagonist, ONO-2952, on stress-induced stool abnormality and abdominal pain in rats, and on anxiety-related behavior induced by cholecystokinin. KEY RESULTS: Oral administration of ONO-2952 attenuated stress-induced defecation and rectal hyperalgesia in rats with an efficacy equivalent to that of a 5-HT3 receptor antagonist. In addition, ONO-2952 suppressed cholecystokinin-induced anxiety-like behavior with an efficacy equivalent to that of psychotropic drugs. On the other hand, ONO-2952 did not affect spontaneous defecation, gastrointestinal transit, visceral nociceptive threshold, and neurosteroid production in non-stressed rats even at a dose 10 times higher than its effective dose in the stress models. CONCLUSIONS AND INFERENCES: These results suggest that TSPO antagonism results in antistress action, and that ONO-2952 is a promising candidate for IBS without side effects associated with current treatment.

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun.

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

A simplified chart for determining the initial loading dose of teicoplanin in critically ill patients.

AIM OF THE STUDY: A simplified chart to determine the initial loading dose of teicoplanin (TEIC chart) for achieving the target trough concentration was developed. The aim of the present study was to evaluate the usefulness of this chart in critically ill patients. PATIENTS AND METHODS: The initial loading dose and maintenance dose to achieve a target trough concentration ≥10 µg/mL on day 4 was determined using the teicoplanin TDM software and presented in a TEIC chart. The dosage of teicoplanin, including the loading dose for the first 2 days and the maintenance dose thereafter, was selected from the chart (chart method, N = 41) or calculated using TDM software (software method, N = 39). RESULTS: The performance rate of initial loading of teicoplanin increased from 83.0% to 100% after the TEIC chart was introduced (P = 0.016). The TEIC chart significantly reduced the time required for determining the initial loading dose compared with the use of software (1.9±0.6 min vs. 29.7±13.8 min, P < 0.001). No significant differences were observed in the rates of achieving a target level ≥10 µg/mL (P = 0.766). CONCLUSION: The TEIC chart enables a simple, rapid, and reliable determination of teicoplanin dosage.

Risk factors for the failure of treatment of Pseudomonas aeruginosa bacteremia in critically ill patients.

Pseudomonas aeruginosa bacteremia is associated with high morbidity and mortality in critically ill patients. In this study, we assessed risk factors for clinical failure of first definitive therapy for P. aeruginosa bacteremia in critically ill patients. All patients with P. aeruginosa bacteremia who entered the intensive care unit in Gifu University Hospital from January 2006 to December 2015 were retrospectively identified from electronic records. Risk factors associated with clinical failure of the first definitive therapy for P. aeruginosa bacteremia were analyzed by logistic regression analysis. A total of 28 patients were enrolled in the analysis. On multivariate analysis, severe burns (odds ratio [OR] = 70.9, 95% CI 2.9-1720.3; p = 0.009) and SOFA score ≥ 10 (OR = 28.5, 95% CI 1.1-754.3; p = 0.045) were significant factors in the clinical failure of first definitive therapy for P. aeruginosa bacteremia. The clinical success rate of first definitive therapy was significantly reduced in patients with these risk factors compared with those without them (p < 0.001). Severe burns and a SOFA score (≥ 10) were significant risk factors associated with the clinical failure of first definitive therapy for P. aeruginosa bacteremia in critically ill patients. We therefore recommend the use of therapeutic drug monitoring to optimize antibiotic dosing in these critically ill patients.

Quiet T1-Weighted Pointwise Encoding Time Reduction with Radial Acquisition for Assessing Myelination in the Pediatric Brain.

BACKGROUND AND PURPOSE: T1-weighted pointwise encoding time reduction with radial acquisition (PETRA) sequences require limited gradient activity and allow quiet scanning. We aimed to assess the usefulness of PETRA in pediatric brain imaging. MATERIALS AND METHODS: We included consecutive pediatric patients who underwent both MPRAGE and PETRA. The contrast-to-noise and contrast ratios between WM and GM were compared in the cerebellar WM, internal capsule, and corpus callosum. The degree of myelination was rated by using 4-point scales at each of these locations plus the subcortical WM in the anterior frontal, anterior temporal, and posterior occipital lobes. Two radiologists made all assessments, and the intra- and interrater agreement was calculated by using intraclass correlation coefficients. Acoustic noise on MPRAGE and PETRA was measured. RESULTS: We included 56 patients 5 days to 14 years of age (mean age, 36.6 months) who underwent both MPRAGE and PETRA. The contrast-to-noise and contrast ratios for PETRA were significantly higher than those for MPRAGE (P < .05), excluding the signal ratio for cerebellar WM. Excellent intra- and interrater agreement were obtained for myelination at all locations except the cerebellar WM. The acoustic noise on PETRA (58.2 dB[A]) was much lower than that on MPRAGE (87.4 dB[A]). CONCLUSIONS: PETRA generally showed better objective imaging quality without a difference in subjective image-quality evaluation and produced much less acoustic noise compared with MPRAGE. We conclude that PETRA can substitute for MPRAGE in pediatric brain imaging.

Early optimization of antimicrobial therapy improves clinical outcomes of patients administered agents targeting methicillin-resistant Staphylococcus aureus.

WHAT IS KNOWN AND OBJECTIVE: Antimicrobial stewardship is required to ensure the appropriate use of antimicrobials. However, no reports have been published on clinical outcomes of implementation of antimicrobial stewardship in patients receiving pathogen-specific antibiotics. METHOD: To evaluate the clinical outcomes of patients who received drugs, we conducted a single-centre, retrospective study of the effects of an antimicrobial stewardship programme targeting methicillin-resistant Staphylococcus aureus (MRSA). RESULTS: The time to administer effective antimicrobials was significantly (median number of days, 3 before vs. 0 after, P < 0·001) shortened, and the rate of de-escalation was significantly elevated (47·1% vs. 96·2%, P < 0·001) after implementation of daily review. The 60-day clinical failure associated with Gram-positive bacterial infection was significantly reduced (33·3% vs. 17·6%, P = 0·007) after intervention. WHAT IS NEW AND CONCLUSIONS: Daily review of administration of antimicrobials targeting MRSA was highly effective in improving clinical outcomes by optimizing early antimicrobial therapy.

Evaluation of the pharmacokinetic parameters of standard oral antibiotics in a bioequivalence study of generic products.

Pharmacokinetic parameters were summarized in clinical bioequivalence studies in Japan to confirm the validity for the use of parameters obtained from the clinical studies. Pharmacokinetic parameters, including maximum plasma/serum concentrations (Cmax), area under the plasma/serum drug concentration-time curve (AUC), time to achieve Cmax (Tmax), and half life (t1/2), of the standard products (original drugs) after oral administration of antimicrobials, including respiratory quinolones, cephalosporins, macrolides, and penicillin-based antibiotics were investigated by use of interview forms and/or package inserts from the generic products and the relationship among the pharmacokinetic parameters such as Cmax, AUC, Tmax, and t1/2 were estimated. In all the studies, the standard and generic products were administrated orally to healthy fasting subjects. Although there was more than a 1.5-fold difference in the Cmax and AUC0-24 h, but not in the Tmax and t1/2 values for levofloxacin tablets and cefacrol tablets, these parameters for other antibiotics were similar in various studies. The obtained results suggested that the parameters obtained from recent bioequivalence studies would be useful in identifying pharmacokinetic behavior of the original drugs, especially early time release; however, the pharmacokinetic results obtained from the recently conducted bioequivalence studies may be superior to those obtained from studies conducted in the past.

Recurrent mutations of CD79B and MYD88 are the hallmark of primary central nervous system lymphomas.

AIMS: Primary central nervous system lymphoma (PCNSL) manifest aggressive clinical behaviour and have poor prognosis. Although constitutive activation of the nuclear factor-κB (NF-κB) pathway has been documented, knowledge about the genetic alterations leading to the impairment of the NF-κB pathway in PCNSLs is still limited. This study was aimed to unravel the underlying genetic profiles of PCNSL. METHODS: We conducted the systematic sequencing of 21 genes relevant to the NF-κB signalling network for 71 PCNSLs as well as the pyrosequencing of CD79B and MYD88 mutation hotspots in a further 35 PCNSLs and 46 glioblastomas (GBMs) for validation. RESULTS: The results showed that 68 out of 71 PCNSLs had mutations in the NF-κB gene network, most commonly affecting CD79B (83%), MYD88 (76%), TBL1XR1 (23%), PRDM1 (20%) and CREBBP1 (20%). These mutations, particularly CD79B and MYD88, frequently coincided within each tumour in various combinations, simultaneously affecting diverse pathways within the network. No GBMs had hotspot mutation of CD79B Y196 and MYD88 L265. CONCLUSIONS: The prevalence of CD79B and MYD88 mutations in PCNSLs was considerably higher than reported in systemic diffuse large B-cell lymphomas. This observation could reflect the paucity of antigen stimuli from the immune system in the central nervous system (CNS) and the necessity to substitute them by the constitutive activation of CD79B and MYD88 that would initiate the signalling cascades. These hotspot mutations may serve as a genetic hallmark for PCNSL serving as a genetic marker for diagnose and potential targets for molecular therapy.

Comprehensive analyses using next-generation sequencing and immunohistochemistry enable precise treatment in advanced gastric cancer.

BACKGROUND: In advanced gastric cancer (AGC), most clinical trials are designed on the basis of protein expression or gene amplification of specific genes. Recently, next-generation sequencing (NGS) allowed us to comprehensively profile the tumor gene status. This study aimed to elucidate the profiling between gene alterations and protein expression in AGC to aid in future clinical trials on AGC. PATIENTS AND METHODS: Formalin-fixed, paraffin-embedded tumor samples from 121 stage III/IV gastric cancer patients were examined for protein expression of tyrosine kinase receptors (RTKs; ERBB2, EGFR, c-MET, and FGFR2) using immunohistochemistry (IHC). Furthermore, 409 cancer-related genes were sequenced to detect mutations and copy number variations using NGS. RESULTS: Most ERBB2 overexpression (IHC 3+) cases (80.0%) had ERBB2 amplification and did not have other RTK amplification or oncogene mutations. However, one-fourth of MET overexpression cases (25.0%) had ERBB2 alterations. EGFR and FGFR2 overexpression cases had ERBB2 alterations or other gene alterations such as KRAS or PIK3CA. On the other hand, most of the four RTK amplification cases (88.2%) were mutually exclusive with each amplification. However, RTK amplification did not simply correlate with protein overexpression, whereas cases with RTK high-level amplification had protein overexpression and rarely showed other co-existing gene alterations. CONCLUSION: AGC involves a complicated arrangement of protein expression and gene alterations. Comprehensive analyses of NGS and IHC will be necessary to design the optimal therapy for treating the appropriate population of patients in future clinical trials.

The relationship between serum calcium level and early-phase insulin secretion in normoglycemic and pre-diabetic individuals.

INTRODUCTION: Type 2 diabetes mellitus (T2DM) is linked to altered calcium metabolism. However, little is known about the relationship between serum calcium levels and early-phase insulin secretion in subjects with normoglycemic tolerance (NGT) or prediabetes (preDM). METHODS: In this gender-separated cross-sectional study, 352 subjects with NGT (215 men and 137 women; age: 48.8±9.1 years and 51.6±6.7 years, respectively) and 316 subjects with preDM (231 men and 85 women; age: 52.5±8.6 years and 54.2±8.0 years, respectively) were examined. Following a 75-g oral glucose tolerance test, early-phase insulin secretion was estimated using the insulinogenic index (IGI) [ΔInsulin(30-0 min)/ΔGlucose(30-0 min)]. RESULTS: Simple linear regression analysis showed that IGI was positively correlated with serum calcium and albumin-adjusted calcium levels in men with NGT and preDM. However, IGI was not correlated with calcium levels in women with NGT and preDM. Multivariate linear regression analysis of men with NGT revealed that the albumin-adjusted calcium level was the major predictor of IGI, responsible for 5.1% of its variation (P=0.003). In addition, in men with preDM, the albumin-adjusted calcium level was one of the predictors of IGI, responsible for 3.8% of its variation (P=0.004). These associations were independent of age, BMI, and HbA1c. CONCLUSIONS: In non-diabetic Japanese men, serum calcium levels significantly correlate with early-phase insulin secretion. Serum calcium levels may be an independent predictor of ß-cell function in men.

The relationship between serum uric acid levels and ß-cell functions in nondiabetic subjects.

High serum uric acid (UA) levels are believed to be an independent risk factor for the development of diabetes. We aimed to investigate the relationship between serum UA concentrations and early-phase insulin secretion following a 75 g oral glucose tolerance test (OGTT) in nondiabetic subjects. We enrolled 570 Japanese subjects (354 males and 216 females, aged 50.5 ± 8.9 years and 52.6 ± 7.3 years, respectively), who underwent the 75 g OGTT during their annual health examination. The OGTT confirmed their nondiabetic status. Insulin secretion was estimated by the disposition index (DI) [(Δ insulin/Δ glucose (0-30 min) × (1/HOMA-IR)], which is an adjusted measure of ß-cell function relative to variations in insulin sensitivity. Simple linear regression analysis showed negative correlations between serum UA levels and DI, when examined in the whole study population and female subjects only (r = -0.209, p < 0.001 and r = -0.232, p < 0.001, respectively). However, in male subjects, UA levels did not correlate with DI. In females, multivariate linear regression analysis revealed that serum UA levels were the major predictors of DI, explaining 16.4% of its variation (p < 0.001). Serum UA levels significantly correlate with early-phase insulin secretion in nondiabetic Japanese women. It may be an independent risk factor for predicting ß-cell function in women.

Effect of NS-018, a selective JAK2V617F inhibitor, in a murine model of myelofibrosis.

A single somatic mutation, V617F, in Janus kinase 2 (JAK2) is one of the causes of myeloproliferative neoplasms (MPNs), including primary myelofibrosis, and the JAK2V617F mutant kinase is a therapeutic target in MPN. However, inhibition of wild-type (WT) JAK2 can decrease the erythrocyte or platelet (PLT) count. Our selective JAK2 inhibitor, NS-018, suppressed the growth of Ba/F3 cells harboring JAK2V617F more strongly than that of cells harboring WT JAK2. The 4.3-fold JAK2V617F selectivity of NS-018 is higher than the 1.0- to 2.9-fold selectivity of seven existing JAK2 inhibitors. NS-018 also inhibited erythroid colony formation in JAK2V617F transgenic mice at significantly lower concentrations than in WT mice. In keeping with the above results, in a JAK2V617F bone marrow transplantation mouse model with a myelofibrosis-like disease, NS-018 reduced leukocytosis and splenomegaly, improved bone marrow fibrosis and prolonged survival without decreasing the erythrocyte or PLT count in the peripheral blood. By exploring the X-ray co-crystal structure of NS-018 bound to JAK2, we identified unique hydrogen-bonding interactions between NS-018 and Gly993 as a plausible explanation for its JAK2V617F selectivity. These results suggest that NS-018 will have therapeutic benefit for MPN patients through both its efficacy and its reduced hematologic adverse effects.

Fundamental study of osteoclast chemotaxis toward chemoattractants expressed in periodontitis.

BACKGROUND AND OBJECTIVE: Periodontitis is a chronic inflammatory disease that leads to bone resorption by osteoclasts (OCs). Several factors contribute to the differentiation of OCs from hematopoietic precursors. Cellular chemotactic factors are expressed in periodontitis tissue, but the effects of these chemoattractants on OCs are not well understood. Here we examined the effects of chemoattractants produced in inflamed periodontal tissue on OC chemotaxis. MATERIAL AND METHODS: Rat bone-marrow OCs were cultured in OC culture medium for 3 or 6 d. Using EZ-TAXIScan™, the chemotactic response of these OCs to several chemoattractants [monocyte chemotactic protein-1; macrophage inflammatory protein 1α; regulated on activation, normal T-cell expressed and secreted; stromal cell-derived factor-1α; and complement activation product 5a (C5a)] was measured. In addition, we measured the effect of C5a-specific inhibitors on chemotactic responses toward C5a. The recorded chemotactic responses were quantitatively analysed using ImageJ software. RESULTS: Chemoattractants associated with periodontal disease significantly increased the chemotactic activity of differentiated rat OCs in a concentration-dependent manner, with C5a inducing the highest chemotactic activity of OCs cultured for 3 or 6 d. The C5a-specific inhibitor significantly inhibited chemotaxis toward C5a in a concentration-dependent manner. CONCLUSION: We suggest that C5a plays an important role in pathologic bone resorption in periodontal disease by stimulating the chemotaxis of OCs. Therefore, C5a is a potential target for the treatment of periodontal disease.

FHL1 on chromosome X is a single-hit gastrointestinal tumor-suppressor gene and contributes to the formation of an epigenetic field defect.

Tumor-suppressor genes on chromosome X can be inactivated by a single hit, any of the point mutations, chromosomal loss and aberrant DNA methylation. As aberrant DNA methylation can be induced frequently, we here aimed to identify a tumor-suppressor gene on chromosome X inactivated by promoter DNA methylation. Of 69 genes on chromosome X upregulated by treatment of a gastric cancer cell line with a DNA-demethylating agent, 5-aza-2'-deoxycytidine, 11 genes had low or no expression in the cell line and abundant expression in normal gastric mucosae. Among them, FHL1 was frequently methylation-silenced in gastric and colon cancer cell lines, and methylated in primary gastric (21/80) and colon (5/50) cancers. Knockdown of the endogenous FHL1 in two cell lines by two kinds of shRNAs significantly increased cell growth in vitro and sizes of xenografts in nude mice. Expression of exogenous FHL1 in a non-expressing cell line significantly reduced its migration, invasion and growth. Notably, a somatic mutation (G642T; Lys214Asn) was identified in one of 144 colon cancer specimens, and the mutant FHL1 was shown to lack its inhibitory effects on migration, invasion and growth. FHL1 methylation was associated with Helicobacter pylori infection and accumulated in normal-appearing gastric mucosae of gastric cancer patients. These data showed that FHL1 is a methylation-silenced tumor-suppressor gene on chromosome X in gastrointestinal cancers, and that its silencing contributes to the formation of an epigenetic field for cancerization.

Outcome measurement of extensive implementation of antimicrobial stewardship in patients receiving intravenous antibiotics in a Japanese university hospital.

BACKGROUND: Antimicrobial stewardship has not always prevailed in a wide variety of medical institutions in Japan. METHODS: The infection control team was involved in the review of individual use of antibiotics in all inpatients (6348 and 6507 patients/year during the first and second annual interventions, respectively) receiving intravenous antibiotics, according to the published guidelines, consultation with physicians before prescription of antimicrobial agents and organisation of education programme on infection control for all medical staff. The outcomes of extensive implementation of antimicrobial stewardship were evaluated from the standpoint of antimicrobial use density, treatment duration, duration of hospital stay, occurrence of antimicrobial-resistant bacteria and medical expenses. RESULTS: Prolonged use of antibiotics over 2 weeks was significantly reduced after active implementation of antimicrobial stewardship (2.9% vs. 5.2%, p < 0.001). Significant reduction in the antimicrobial consumption was observed in the second-generation cephalosporins (p = 0.03), carbapenems (p = 0.003), aminoglycosides (p < 0.001), leading to a reduction in the cost of antibiotics by 11.7%. The appearance of methicillin-resistant Staphylococcus aureus and the proportion of Serratia marcescens to Gram-negative bacteria decreased significantly from 47.6% to 39.5% (p = 0.026) and from 3.7% to 2.0% (p = 0.026), respectively. Moreover, the mean hospital stay was shortened by 2.9 days after active implementation of antimicrobial stewardship. CONCLUSION: Extensive implementation of antimicrobial stewardship led to a decrease in the inappropriate use of antibiotics, saving in medical expenses, reduction in the development of antimicrobial resistance and shortening of hospital stay.

Early-stage formation of an epigenetic field defect in a mouse colitis model, and non-essential roles of T- and B-cells in DNA methylation induction.

Epigenetic fields for cancerization are involved in development of human cancers, especially those associated with inflammation and multiple occurrences. However, it is still unclear when such field defects are formed and what component of inflammation is involved in induction of aberrant DNA methylation. Here, in a mouse colitis model induced by dextran sulfate sodium (DSS), we identified three CpG islands specifically methylated in colonic epithelial cells exposed to colitis. Their methylation levels started to increase as early as 8 weeks after DSS treatment and continued to increase until colon cancers developed at 15 weeks. In contrast to the temporal profile of DNA methylation levels, infiltration of inflammatory cells spiked immediately after the DSS treatment and then gradually decreased. Exposure of cultured colonic epithelial cells to DSS did not induce DNA methylation and it was indicated that inflammation triggered by the DSS treatment was responsible for methylation induction. To clarify components of inflammation involved, severe combined immunodeficiency (SCID) mice that lack functional T- and B-cells were similarly treated. Even in SCID mice, DNA methylation, along with colon tumors, were induced at the same levels as in their background strain of mice (C.B17). Comparative analysis of inflammation-related genes showed that Ifng, Il1b and Nos2 had expression concordant with methylation induction whereas Il2, Il6, Il10, Tnf did not. These results showed that an epigenetic field defect is formed at early stages of colitis-associated carcinogenesis and that functional T and B cells are non-essential for the formation.