Efficacy of cefmetazole in immunocompetent patients with uncomplicated colonic diverticulitis: A propensity score matching analysis.

INTRODUCTION: The incidence of colonic diverticulitis is increasing in Japan. Although antimicrobial chemotherapy is a treatment option, Japanese guidelines for diverticulosis do not recommend any antibiotic in particular and antibiotic selection is left to the discretion of the prescribing physician, who often selects antibiotics with anti-pseudomonal activity. Therefore, this study compared the efficacy of cefmetazole (CMZ) with that of tazobactam/piperacillin (TAZ/PIPC) in hospitalized Japanese immunocompetent patients with uncomplicated colonic diverticulitis. PATIENTS AND METHODS: This retrospective study included Japanese immunocompetent patients hospitalized for colonic diverticulitis between April 2019 and March 2022. Participants were divided into the CMZ and TAZ/PIPC groups. After propensity score matching, the intergroup differences in clinical outcomes, including adverse events, mortality, and re-admission rate, were ascertained. RESULTS: During the study period, 142 Japanese patients were hospitalized with community-onset colonic diverticulitis; 124 of these patients were immunocompetent. Of the 124 patients, 42 were excluded, and the CMZ and TAZ/PIPC groups comprised 62 and 20 patients, respectively. After propensity score matching, there were 16 patients in each group. There was no significant intergroup difference in the mortality and re-admission rates; however, the incidence of liver dysfunction was significantly higher (p = 0.018) in the TAZ/PIPC group. CONCLUSION: In patients with colonic diverticulitis, CMZ therapy should be selected because of the adequate clinical outcomes and lower incidence of adverse events, as this would reduce broad-spectrum antibiotic use and minimize antibiotic-resistant bacteria.

The Balance of CD8-Positive T Cells and PD-L1 Expression in the Myocardium Predicts Prognosis in Lymphocytic Fulminant Myocarditis.

INTRODUCTION: The clinical significance and prognostic value of T cell involvement and programmed cell death-1 (PD-1)/programmed cell death ligand-1 (PD-L1) have not been established in lymphocytic fulminant myocarditis (FM). We investigated the prognostic impact of the number of CD4+, CD8+, FoxP3+, and PD-1+ T cells, as well as PD-L1 expression, in cardiomyocytes in lymphocytic FM. METHODS: This is a single-center observational cohort study. Myocardial tissue was obtained from 16 consecutive patients at lymphocytic FM onset. The median follow-up was 140 days. Cardiac events were defined as a composite of cardiac death and left ventricular-assist device implantation. CD4, CD8, FoxP3, PD-1, and PD-L1 immunostaining were performed on myocardial specimens. RESULTS: The median age of the patients was 52 years (seven men and nine women). There was no significant difference in the number of CD4+ cells. The number of CD8+ cells and the CD8+/CD4+ T cell ratio were higher in the cardiac event group (Event+) than in the group without cardiac events (Event-) (p = 0.048 and p = 0.022, respectively). The number of FoxP3+ T cells was higher in the Event+ group (p = 0.049). Although there was no difference in the number of PD-1+ cells, cardiomyocyte PD-L1 expression was higher in the Event+ group (p = 0.112). Event-free survival was worse in the group with a high CD8+ cell count (p = 0.012) and high PD-L1 expression (p = 0.049). When divided into three groups based on the number of CD8+ cells and PD-L1 expression (CD8highPD-L1high [n = 8], CD8lowPD-L1high [n = 1], and CD8lowPD-L1low [n = 7]), the CD8highPD-L1high group demonstrated the worst event-free survival, while the CD8lowPD-L1high group had a favorable prognosis without cardiac events (p = 0.041). CONCLUSION: High myocardial expression of CD8+ T cells and PD-L1 may predict a poor prognosis in lymphocytic FM.

G-protein-coupled estrogen receptor prevents nuclear factor-kappa B promoter activation by Helicobacter pylori cytotoxin-associated gene A in gastric cancer cells.

Helicobacter pylori is a well-known pathogen that causes chronic gastritis, leading to the development of gastric cancer. This bacterium has also been detected in dogs, and symptoms similar to those in humans have been reported. The cytotoxin-associated gene A (CagA) is involved in pathogenesis through aberrant activation of host signal transduction, including the nuclear factor-kappa B (NF-κB) pathway. We have previously shown the anti-inflammatory effect of the G-protein-coupled estrogen receptor (GPER) via inhibiting of NF-κB activation in several cells. Therefore, here, we investigated the effect of GPER on CagA-mediated NF-κB promoter activity and showed that CagA overexpression in gastric cancer cells activated the NF-κB reporter and induced interleukin 8 (il-8) expression, both of which were inhibited by the GPER agonist.

The Drug-Specific Propensity Regarding the Acquisition of Fluoroquinolone Resistance in Escherichia coli: An in vitro Challenge and DNA Mutation Analysis.

Objective: Many fluoroquinolones, such as ciprofloxacin, are used clinically. We investigated the relationship between resistance acquisition and exposure duration in each drug through the exposure of fluoroquinolone to Escherichia coli clinical isolates in vitro. Methods: Eleven E. coli clinical isolates were exposed to each fluoroquinolone, ie, ciprofloxacin, levofloxacin, sitafloxacin, garenoxacin, and lascufloxacin, with the concentration of the mutant selection window for 5 days; these procedures were repeated 5-times. In addition, the DNA sequence in the quinolone-resistance determining region (QRDR) and the expression level in the drug efflux pump acrA were analyzed to determine the resistance mechanism. Results: Although resistant strains were not detected after 5 to 10 days of exposure to fluoroquinolone, after 25 days of exposure to ciprofloxacin and levofloxacin, 100% and 45% of isolates acquired resistance, respectively. Due to 25 days of exposure to sitafloxacin, garenoxacin, and lascufloxacin, MIC measurement was elevated 2- to 4096-fold for those of the parental strain, and the cross-resistance rate to levofloxacin was 72%, 54%, and 27%, respectively. In strains with high fluoroquinolone resistance, acrA overexpression was observed in addition to QRDR mutation. Conclusion: In our findings, fluoroquinolone resistance was not observed in the E. coli strain after 5- to 10-days of exposure. However, resistance acquisition was detected frequently after 15- to 25-days of exposure. Among fluoroquinolones, lascufloxacn had the least impact on the resistance acquisition in E. coli.

A Case of Recurrent Verruconis gallopava Infection at One Year after Excision of a Solitary Pulmonary Lesion.

We herein report a case of recurrent infection caused by Verruconis gallopava, which is known to cause fatal phaeohyphomycosis. A 71-year-old man presented with a fever, and computed tomography revealed right chest wall thickening. Eleven years earlier, he had undergone autologous peripheral blood stem cell transplantation for a hematological malignancy. One year earlier, he had undergone excision of a solitary pulmonary nodule, from which had been detected V. gallopava. On this occasion, right chest wall surgery was performed to investigate the cause of the fever, which led to the diagnosis of recurrent infection. Even if a localized lesion is excised, additional antifungal therapy should be performed.

Influence of dichroism on the optical properties of a twisted nematic liquid crystal cell in the terahertz region.

Polarization control is essential in terahertz (THz) imaging. Liquid crystals (LCs) have the potential to functionalize tunable polarization-control devices. Here, a twisted nematic (TN) cell using a hydrogen-bonded LC is fabricated, and the influence of dichroism in the THz region is discussed. Our results indicate that the polarization state in the Gooch-Tarry minimum condition is affected by the LC dichroism; a nondichroic LC is required for complete linearly polarized output. The output intensity of the dichroic LC-TN cell changed when electrically switched or when the incident THz wave polarization direction was rotated 90°. These intensity variations disappeared when using the nondichroic hydrogen-bonded LC.

Treatment of CHO cells with Taxol and reversine improves micronucleation and microcell-mediated chromosome transfer efficiency.

Microcell-mediated chromosome transfer is an attractive technique for transferring chromosomes from donor cells to recipient cells and has enabled the generation of cell lines and humanized animal models that contain megabase-sized gene(s). However, improvements in chromosomal transfer efficiency are still needed to accelerate the production of these cells and animals. The chromosomal transfer protocol consists of micronucleation, microcell formation, and fusion of donor cells with recipient cells. We found that the combination of Taxol (paclitaxel) and reversine rather than the conventional reagent colcemid resulted in highly efficient micronucleation and substantially improved chromosomal transfer efficiency from Chinese hamster ovary donor cells to HT1080 and NIH3T3 recipient cells by up to 18.3- and 4.9-fold, respectively. Furthermore, chromosome transfer efficiency to human induced pluripotent stem cells, which rarely occurred with colcemid, was also clearly improved after Taxol and reversine treatment. These results might be related to Taxol increasing the number of spindle poles, leading to multinucleation and delaying mitosis, and reversine inducing mitotic slippage and decreasing the duration of mitosis. Here, we demonstrated that an alternative optimized protocol improved chromosome transfer efficiency into various cell lines. These data advance chromosomal engineering technology and the use of human artificial chromosomes in genetic and regenerative medical research.

Cardiac sympathetic activity and relationship to cardiac events and left ventricular reverse remodeling in patients with non-ischemic dilated cardiomyopathy.

BACKGROUND: Delayed heart-to-mediastinum ratio (HMR) has been associated with catecholamine levels and contractile reserve in dilated cardiomyopathy (DCM); however, there is scant evidence regarding the association between cardiac sympathetic activity and left ventricular reverse remodeling (LV-RR). We calculated the 123I-metaiodobenzylguanidine (123I-mIBG) HMR and washout rate (WR) in patients with DCM and investigated their associations with LV-RR. METHODS: From April 2003 to January 2020, in 120 patients with DCM who underwent 123I-mIBG scintigraphy. 66 patients undergoing follow-up echo and taking a beta-blocker from baseline were examined the relationship between 123I-mIBG and LV-RR. After that, this prognostic value for composite cardiac events was evaluated in the entire 120 patients. RESULTS: In LV-RR analysis, patients were 50.4 ± 12.2 years, with a mean left ventricular ejection fraction of 28.6%. Of 66 patients, 28 (42.4%) achieved LV-RR. Multiple logistic regression analysis of LV-RR revealed that not delayed HMR but the WR (cutoff value: 13.5%) was an independent predictor of LV-RR (odds ratio 6.514, p = 0.002). In the analysis for composite cardiac events, even though WR itself does not have the prognostic capacity, Kaplan-Meier survival curves divided by the cutoff value (delayed HMR = 2.0, WR = 13.5) showed that delayed HMR and WR values enabled the stratification of high-risk patients (log-rank p < 0.001). CONCLUSIONS: The 123I-mIBG WR was associated with the prevalence of LV-RR in patients taking 100% of beta-blockers and 98.5% of renin-angiotensin system inhibitors. Reflecting the contractile reserve, the combined assessment of the delayed HMR and WR could be used to further precisely stratify the patients with DCM.

Dilated cardiomyopathy with anti-mitochondrial M2 antibody: A case series.

Patients with dilated cardiomyopathy (DCM) sometimes show anti-mitochondrial M2 antibody (AMA-M2) positivity. We aimed to compare the characteristics of DCM cases with and without AMA-M2, and to describe cases of DCM with AMA-M2 positivity.A total of 84 patients with DCM were analyzed. Six patients (7.1 %) were positive for AMA-M2. Of these six patients, five (83.3 %) had primary biliary cirrhosis (PBC) and four (66.7 %) had myositis. Patients with AMA-M2 positivity had more atrial fibrillation and more premature ventricular contractions than those without. Left and right atrial longitudinal dimensions were larger in patients with AMA positivity (left atrium, 65.9 mm vs. 54.7 mm, p = 0.02; right atrium, 57.0 mm vs. 46.1 mm, p = 0.02). Of the six patients with AMA-M2 positivity, three underwent cardiac resynchronization therapy with defibrillator implantation and three required catheter ablation treatment. Steroids were used in three patients. One patient died of unresolved lethal arrhythmia and another required re-hospitalization for heart failure; the remaining four patients did not have adverse events.Patients with DCM with AMA-M2 positivity had a higher affinity for PBC and myositis than those without, and are characterized by atrial enlargement and arrhythmias. Learning objective: Patients with dilated cardiomyopathy sometimes exhibit anti-mitochondrial M2 antibody positivity. These patients are at higher risk for primary biliary cirrhosis and inflammatory myositis, and their cardiac disorders are characterized by atrial enlargement and various arrhythmias. The course of the disease up to the time of diagnosis and after steroid use varies, and the prognosis is poor in advanced cases.

Contractile pericarditis-like hemodynamics in dilated-phase hypertrophic cardiomyopathy with giant atrium.

A 47-year-old man with dilated-phase hypertrophic cardiomyopathy was admitted to the hospital with worsening heart failure. As the enlarged atrium caused a constrictive pericarditis-like hemodynamic condition, atrial wall resection and tricuspid valvuloplasty were performed. Postoperatively, pulmonary artery pressure rose due to increased preload; however, the rise in pulmonary artery wedge pressure was restrained, and the cardiac output significantly improved. When the pericardium is extremely stretched due to atrial enlargement, it can lead to an elevation of intrapericardial pressure, and both atrial volume reduction and tricuspid valve plasty could lead to increased compliance and contribute to hemodynamic improvement. Learning objective: Atrial wall resection for massive atrial enlargement and tricuspid annuloplasty in patients with diastolic-phase hypertrophic cardiomyopathy effectively relieves unstable hemodynamics.

Comprehensive circulating microRNA profile as a supersensitive biomarker for early-stage lung cancer screening.

PURPOSE:  Less-invasive early diagnosis of lung cancer is essential for improving patient survival rates. The purpose of this study is to demonstrate that serum comprehensive miRNA profile is high sensitive biomarker to early-stage lung cancer in direct comparison to the conventional blood biomarker using next-generation sequencing (NGS) technology combined with automated machine learning (AutoML). METHODS: We first evaluated the reproducibility of our measurement system using Pearson's correlation coefficients between samples derived from a single pooled RNA sample. To generate comprehensive miRNA profile, we performed NGS analysis of miRNAs in 262 serum samples. Among the discovery set (57 patients with lung cancer and 57 healthy controls), 1123 miRNA-based diagnostic models for lung cancer detection were constructed and screened using AutoML technology. The diagnostic faculty of the best performance model was evaluated by inspecting the validation samples (74 patients with lung cancer and 74 healthy controls). RESULTS: The Pearson's correlation coefficients between samples derived from the pooled RNA sample ≥ 0.98. In the validation analysis, the best model showed a high AUC score (0.98) and a high sensitivity for early stage lung cancer (85.7%, n = 28). Furthermore, in comparison to carcinoembryonic antigen (CEA), a conventional blood biomarker for adenocarcinoma, the miRNA-based model showed higher sensitivity for early-stage lung adenocarcinoma (CEA, 27.8%, n = 18; miRNA-based model, 77.8%, n = 18). CONCLUSION: The miRNA-based diagnostic model showed a high sensitivity for lung cancer, including early-stage disease. Our study provides the experimental evidence that serum comprehensive miRNA profile can be a highly sensitive blood biomarker for early-stage lung cancer.

Phagocytosis is a primary determinant of pulmonary clearance of clinical Klebsiella pneumoniae isolates.

Introduction: Klebsiella pneumoniae (Kp) is a common cause of hospital-acquired pneumonia. Although previous studies have suggested that evasion of phagocytic uptake is a virulence determinant of Kp, few studies have examined phagocytosis sensitivity in clinical Kp isolates. Methods: We screened 19 clinical respiratory Kp isolates that were previously assessed for mucoviscosity for their sensitivity to macrophage phagocytic uptake, and evaluated phagocytosis as a functional correlate of in vivo Kp pathogenicity. Results: The respiratory Kp isolates displayed heterogeneity in the susceptibility to macrophage phagocytic uptake, with 14 out of 19 Kp isolates displaying relative phagocytosis-sensitivity compared to the reference Kp strain ATCC 43816, and 5 out of 19 Kp isolates displaying relative phagocytosis-resistance. Intratracheal infection with the non-mucoviscous phagocytosis-sensitive isolate S17 resulted in a significantly lower bacterial burden compared to infection with the mucoviscous phagocytosis-resistant isolate W42. In addition, infection with S17 was associated with a reduced inflammatory response, including reduced bronchoalveolar lavage fluid (BAL) polymorphonuclear (PMN) cell count, and reduced BAL TNF, IL-1ß, and IL-12p40 levels. Importantly, host control of infection with the phagocytosis-sensitive S17 isolate was impaired in alveolar macrophage (AM)-depleted mice, whereas AM-depletion had no significant impact on host defense against infection with the phagocytosis-resistant W42 isolate. Conclusion: Altogether, these findings show that phagocytosis is a primary determinant of pulmonary clearance of clinical Kp isolates.

Cardiac Rehabilitation in Severe Heart Failure Patients with Impella 5.0 Support via the Subclavian Artery Approach Prior to Left Ventricular Assist Device Implantation.

Impella 5.0 circulatory support via subclavian artery (SA) access may be a safe approach for patients undergoing cardiac rehabilitation (CR). In this case series, we retrospectively analyzed the demographic characteristics, physical function, and CR data of six patients who underwent Impella 5.0 implantation via the SA prior to left ventricular assist device (LVAD) implantation between October 2013 and June 2021. The median age was 48 years, and one patient was female. Grip strength was maintained or increased in all patients before LVAD implantation (pre-LVAD) compared to after Impella 5.0 implantation. The pre-LVAD knee extension isometric strength (KEIS) was less than 0.46 kgf/kg in two patients and more than 0.46 kgf/kg in three patients (unavailable KEIS data, n = 1). With Impella 5.0 implantation, two patients could ambulate, one could stand, two could sit on the edge of the bed, and one remained in bed. One patient lost consciousness during CR due to decreased Impella flow. There were no other serious adverse events. Impella 5.0 implantation via the SA allows mobilization, including ambulation, prior to LVAD implantation, and CR can be performed relatively safely.

Indocyanine green-fluorescent imaging for a detection of accessory pancreatic duct in pancreas-preserving duodenectomy.

Pancreas-preserving duodenectomy is indicated for select patients with a duodenal tumor in the second portion. In this procedure, identification and closure of the accessory pancreatic duct is important to prevent postoperative pancreatic fistula. A 63-y-old man was diagnosed with duodenal mucosal carcinoma in the second portion, with invasion of the major ampullary. We performed pancreas-preserving duodenectomy. Intraoperatively, indocyanine green-fluorescent imaging identified the accessory pancreatic duct clearly and it was successfully closed. Postoperative pancreatic fistula did not occur. Indocyanine green-fluorescent imaging is effective in identifying the accessory pancreatic duct in pancreas-preserving duodenectomy.

Dynamic chest radiography as a novel minimally invasive hemodynamic imaging method in patients with heart failure.

PURPOSE: Dynamic chest radiography allows for non-invasive cardiopulmonary blood flow assessment. However, data on its use for heart failure hemodynamic assessment are scarce. We utilized dynamic chest radiography to estimate heart failure hemodynamics. METHOD: Twenty heart failure patients (median age, 67 years; 17 men) underwent dynamic chest radiography and right heart catheterization. The analyzed images were 16-bit images (grayscale range: 0-65,535). Right atrial, right pulmonary artery, and left ventricular apex pixel values (average of the grayscale values of all pixels within a region of interest) were measured. The correlations of the minimum, maximum, mean, amount of change, and rate of change in pixel values with right atrial pressure, pulmonary artery pressure, pulmonary artery wedge pressure, and cardiac index were analyzed. RESULTS: The mean right atrial pixel value and mean right atrial pressure (R = -0.576, P = 0.008), mean right pulmonary artery pixel value and mean pulmonary artery pressure (R = -0.546, P = 0.013), and left ventricular apex pixel value change rate and mean pulmonary artery wedge pressure (R = -0.664, P = 0.001) or cardiac index (R = 0.606, P = 0.005) were correlated. The left ventricular apex pixel value change rate identified low cardiac index (area under the curve, 0.792; 95% confidence interval, 0.590-0.993; P = 0.031) and low cardiac index with high pulmonary artery wedge pressure (area under the curve, 0.902; 95% confidence interval, 0.000-1.000; P = 0.030). CONCLUSIONS: Dynamic chest radiography is a minimally invasive tool for heart failure hemodynamic assessment.

Increased risk of purge system malfunction after Impella 5.0 replacement: a case series.

The Impella 5.0 is an axial-flow percutaneous ventricular assist device used in patients with cardiogenic shock. Although the recommended period of use is 10 days or less, weaning can be delayed because of ongoing hemodynamic instability. In clinical practice, this device sometimes malfunctions during long-term management with heparin and must be replaced; however, the relationship between the duration of support with the initial and replacement Impella 5.0 and the changes in value of the purge system has not been fully elucidated. From July 2018 to May 2021, Impella 5.0 was implanted and used for more than 10 days in 11 patients at our institution. Four patients required Impella replacement because of device malfunction and the second Impella had purge system malfunction in all cases. The second Impella was used for a significantly shorter time than the first Impella (p = 0016). We calculated the ratio of purge pressure to purge flow rate and found that the ratio exceeded 50 mm Hg/mL/h in all cases with purge system malfunction. In conclusion, it is important to construct a treatment strategy considering the duration of use, because the risk of purge system malfunction is high after replaced Impella 5.0.

The ridge line of left pulmonary vein isolation from left atrial appendage can subsequently increase the completion rate of the mitral isthmus block line.

BACKGROUND AND OBJECTIVES: Mitral isthmus (MI) ablation for mitral flutter is technically difficult, and incomplete block line is not uncommon. The objective of this study is to investigate the effect of the ridge line of left pulmonary vein isolation (LPVI) from left atrial appendage (LAA) on completion rate of mitral isthmus (MI) block line and recurrence rate of atrial tachycardia (AT) or atrial flutter (AFL) after the first MI ablation. METHODS: We identified 611 patients who underwent first MI ablation for mitral flutter during the study period. Finally, 559 patients were enrolled and divided into two groups according to the method of ridge line ablation of LPVI (LAA group, n = 467, conventional group, n = 92). Outcome measures were the completion of MI block line by first MI ablation, the recurrence of AT/AFL, and repeat MI ablation after the first MI ablation. RESULTS: The first MI block line completion rate was significantly higher in the LAA group than the conventional group (95% vs. 85%, p < 0.001). The recurrence rate of AT/AFL after 3 months from first MI ablation was significantly lower in the LAA group. The requirement of additional MI ablation tended to be lower in the LAA group. CONCLUSIONS: Our novel approach of ablating LPV-LAA ridge from the LAA side during PVI can increase the success rate of MI block line completion, and reduce the recurrence rate of AT/AFL and the need for additional MI block line ablation. Graphical abstract Ablation of the left pulmonary vein-left atrial appendage ridge from the left atrial appendage side during PVI increased the success rate of mitral isthmus block line completion.

An epidemiological evaluation of COVID-19 in La paz, Bolivia.

INTRODUCTION: The Plurinational State of Bolivia (Bolivia) has experienced four major waves of coronavirus disease 2019 (COVID-19) so far. Although the ministry of health has been tracking morbidity and mortality through each wave, epidemiology of COVID-19 in Bolivia is not well defined, despite a need for more accurate measurement of the number of cases and deaths to allow for forecasting of the pandemic. This study examined prevalence of COVID-19 at community level, determinants of its occurrence and vaccine effectiveness. METHODS: We conducted a cross-sectional study in La Paz city on 2,775 individuals between March 2020 and February 2022. A structured questionnaire was used to collect data on COVID-19 morbidity, mortality and vaccination status. RESULTS: Of the 2,775 participants, 1,586 (57.1%) were infected with COVID-19, and 187 (6.7%) were suspected cases. The mortality rate was 2.9%. Sinopharm, Johnson & Johnson, Gamaleya, Pfizer-BioNtech, Moderna and AstraZeneka vaccines are in use, and all vaccines have demonstrated effectiveness in reducing the risk of onset. Risk for mortality was significantly lower in the vaccinated group with an odds ratio of 0.037 (95％ confidential interval: 0.01-0.10, p-value: <0.001). CONCLUSIONS: Actual prevalence of COVID-19 in La Paz (the prevalence rate: 63.8%, including suspected case) was higher than that reported by the Ministry of Health and Sports in Bolivia (7.5%). In addition, vaccination has contributed significantly to the control of the COVID-19 epidemic in Bolivia. We believe that our report will be useful for COVID-19 prevention strategies in Bolivia for the future.

Cefmetazole Resistance Mechanism for Escherichia Coli Including ESBL-Producing Strains.

Purpose: Cefmetazole (CMZ), a cephamycin antibiotic, is primarily used as a definitive therapy for Extended Spectrum ß-Lactamase (ESBL)-producing Escherichia coli infections. However, the mechanism of CMZ resistance in E. coli is still unknown. To elucidate the resistance mechanism and to determine combined drugs for prevention of resistance acquisition. Methods: Clinical isolates of 14 ESBL-producing E. coli and non-producing 12 isolates were used in in vitro testing of CMZ resistance acquisition. After 10-day of CMZ exposure (1st subculture), these strains were incubated in an antibacterial-free medium for 14-day. These strains were again exposed to CMZ for 10-day (2nd subculture) and confirmed for changes in MIC. For each strain detected after 1st subculture, each mRNA expression level of porin, chromosomal ampC, and drug-efflux pump was measured using real-time RT-PCR. Relebactam (REL) has the potency to recover antimicrobial activity against carbapenem-resistant Enterobacterales that has porin deficiency. REL was added to the CMZ dilution series, and MIC changes and those of porin were confirmed. Results: Of these 26 strains, 15 strains (57.7%) acquired resistance after 1st subculture, but after passage culture on the antibacterial-free medium, 11 strains recovered susceptibility. These 11 strains showed resistance after 2nd subculture. The expression levels of ompF and ompC were significantly decreased in these strains (P<0.05). When REL was added, all strains suppressed resistance acquisition after 1st subculture. The mechanism was the activation of ompF. Conclusion: Our results showed that the mRNA expression levels of genes encoding porin were decreased in the strains that acquired resistance due to CMZ exposure, and that ompF and ompC in particular were thought to be involved in the acquisition of resistance. The CMZ acquisition of resistance was also suppressed by the concomitant use of REL and actually suppressed the decrease in mRNA expression in ompF. It was confirmed that porin reactivated by REL.

Synthesis of the matriglycan hexasaccharide, -3Xylα1-3GlcAß1-trimer and its interaction with laminin.

Matriglycan, a polysaccharide that is a pivotal part of the core M3 O-mannosyl glycan composed of the repeating disaccharide -3Xylα1-3GlcAß1-, interacts with laminin to stabilize muscle tissue. We herein report the synthesis of matriglycan-repeating hexasaccharides equipped with an alkyne linker to form glycoconjugates. The key step in the formation of an α-linked xylosyl glycoside was resolved by solvent-specific separation from an anomeric mixture. Successful glycan elongation was regio- and stereoselectively performed to obtain (-3Xylα1-3GlcAß1)3-O(C2H4O)3CH2CCH and the biotin conjugate. We also investigated interactions between matriglycan hexasaccharides and laminin-G-like domains 4 and 5 of laminin-α2 using saturation transfer difference-NMR. The dissociation constant obtained from bio-layer interferometry was estimated to be 7.5 × 10-8 M. These results indicate that a chemical approach may be applied to the reconstruction of muscle tissue.