Using Data-Dependent and -Independent Hybrid Acquisitions for Fast Liquid Chromatography-Based Untargeted Lipidomics.

Untargeted lipidomics using liquid chromatography (LC) coupled with tandem mass spectrometry (MS) is essential for large cohort studies. Using a fast LC gradient of less than 10 min for the rapid screening of lipids decreases the annotation rate, because of the lower coverage of the MS/MS spectra caused by the narrow peak width. A systematic procedure is proposed in this study to achieve a high annotation rate in fast LC-based untargeted lipidomics by integrating data-dependent acquisition (DDA) and sequential window acquisition of all-theoretical mass spectrometry data-independent acquisition (SWATH-DIA) techniques using the updated MS-DIAL program. This strategy uses variable SWATH-DIA methods for quality control (QC) samples, which are a mixture of biological samples that were analyzed multiple times to correct the MS signal drift. In contrast, biological samples are analyzed using DDA to facilitate the structural elucidation of lipids using the pure spectrum to the maximum extent. The workflow is demonstrated using an 8.6 min LC gradient, where the QC samples are analyzed using five different SWATH-DIA methods. The use of both DDA and SWATH-DIA achieves a 1.7-fold annotation coverage from publicly available benchmark data obtained using a fast LC-DDA-MS technique and offers 95.3% lipid coverage, as compared to the benchmark data set from a 25 min LC gradient. This study demonstrates that harmonized improvements in analytical conditions and informatics tools provide a comprehensive lipidome in fast LC-based untargeted lipidomics, not only for large-scale studies but also for small-scale experiments, contributing to both clinical applications and basic biology.

A Procedure for Solid-Phase Extractions Using Metal-Oxide-Coated Silica Column in Lipidomics.

Lipid enrichment is indispensable for enhancing the coverage of targeted molecules in mass spectrometry (MS)-based lipidomics studies. In this study, we developed a simple stepwise fractionation method using a titanium- and zirconium-dioxide-coated solid-phase extraction (SPE) silica column that separates neutral lipids, phospholipids, and other lipids, including fatty acids (FAs) and glycolipids. Chloroform was used to dissolve the lipids, and neutral lipids, including steryl esters, diacylglycerols, and triacylglycerols, were collected in the loading fraction. Second, methanol with formic acid (99:1, v/v) was used to retrieve FAs, ceramides, and glycolipids, including glycosylated ceramides and glycosylated diacylglycerols, by competing for affinity with the Lewis acid sites on the metal oxide surface. Finally, phospholipids strongly retained via chemoaffinity interactions were eluted using a solution containing 5% ammonia and high water content (45:50 v/v, 2-propanol:water), which canceled the electrostatic and chelating interactions with the SPE column. High average reproducibility of <10% and coverage of ∼100% compared to those of the non-SPE samples were demonstrated by untargeted lipidomics of human plasma and mouse brain, testis, and feces. The advantage of our procedure was showcased by characterizing minor lipid subclasses, including dihexosylceramides containing very long-chain polyunsaturated FA in the testis, monogalactosyl and digalactosyl monoacylglycerols in feces, and acetylated and glycolylated derivatives of gangliosides in the brain that were not detected using conventional solvent extraction methods. Likewise, the value of our method in biology is maximized during glycolipidome profiling in the absence of neutral lipids and phospholipids that cover more than 80% of the chromatographic peaks.

Clinical outcomes of endoscopic submucosal dissection for esophageal squamous cell carcinoma with esophageal varices: Multicenter retrospective study.

OBJECTIVES: Clinical outcomes of endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) with esophageal varices (EVs) are obscure. We aimed to elucidate the clinical outcomes of ESD for ESCC with EVs in a multicenter, retrospective study. METHODS: We established a retrospective cohort of 30 patients with ESCC complicating EVs, who underwent ESD at 11 Japanese institutions. Rates of en bloc resection and R0 resection, procedure time, and adverse events were evaluated as indicators of the feasibility and safety of ESD. Additional treatment, recurrence, and metastasis of the lesions were evaluated as indicators of the long-term efficacy of ESD. RESULTS: Portal hypertension was caused by cirrhosis, of which alcohol was the most common cause. En bloc resection was achieved in 93.3% and R0 resection in 80.0% of the patients. The median procedure time was 92 min. Adverse events included a case of uncontrolled intraoperative bleeding leading to discontinuation of ESD and a case of esophageal stricture due to extensive resection. During the follow-up period of a median for 42 months, a patient with local recurrence and another patient with liver metastasis were observed. One patient died of liver failure after receiving chemoradiotherapy as an additional treatment after ESD. No patient died of ESCC. CONCLUSION: This multicenter, retrospective cohort study demonstrated the safety and efficacy of ESD for ESCC with EVs. Further studies are needed to establish appropriate treatment methods for EVs before ESD and additional treatments for patients with insufficient ESD.

Protecting-group-free glycosylation of phosphatidic acid in aqueous media.

The glycosylation of unprotected carbohydrates has emerged as an area of significant interest because it obviates the need for long reaction sequences involving protecting-group manipulations. Herein, we report the one-pot synthesis of anomeric glycosyl phosphates through the condensation of unprotected carbohydrates with phospholipid derivatives while retaining high stereo- and regioselective control. The anomeric center was activated using 2-chloro-1,3-dimethylimidazolinium chloride to facilitate condensation with glycerol-3-phosphate derivatives in an aqueous solution. A water/propionitrile mixture provided superior stereoselectivity while maintaining good yields. Under these optimized conditions, the condensation of stable isotope-labeled glucose with phosphatidic acid provided efficient access to labeled glycophospholipids as an internal standard for mass spectrometry.

Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of the Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2019-2020: General view of the pathogens' antibacterial susceptibility.

The trends and prevalence of antimicrobial susceptibility of pathogens vary by country, region, and time. Long-term regular surveillance is required to investigate trends in the antimicrobial resistance of various isolated bacterial pathogens. We report the results of a nationwide surveillance on the antimicrobial susceptibility of bacterial respiratory pathogens in Japan conducted by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology. The isolates were collected from clinical specimens obtained from adult patients who visited a collaborating medical facility between June 2019 and December 2020 and were diagnosed with respiratory tract infections by a physician. Antimicrobial susceptibility testing was performed in a centralized laboratory according to the methods recommended by the Clinical and Laboratory Standards Institute. Susceptibility testing was performed for 932 strains (201 Staphylococcus aureus, 158 Streptococcus pneumoniae, 6 S. pyogenes, 136 Haemophilus influenzae, 127 Moraxella catarrhalis, 141 Klebsiella pneumoniae, and 163 Pseudomonas aeruginosa) collected from 32 facilities in Japan. The proportions of methicillin-resistant S. aureus and penicillin-resistant S. pneumoniae were 35.3% and 0%, respectively. In H. influenzae, 16.2% and 16.9% were ß-lactamase-producing ampicillin resistant and ß-lactamase-negative ampicillin resistant, respectively. Extended-spectrum ß-lactamase-producing K. pneumoniae accounted for 5.0% of all K. pneumoniae infections. Carbapenemase-producing K. pneumoniae and multi-drug-resistant P. aeruginosa with metallo-ß-lactamase were not detected in this study. This surveillance will be a useful reference for treating respiratory infections in Japan and will provide evidence to enhance the appropriate use of antimicrobial agents.

Lipid Profiling of Serum and Lipoprotein Fractions in Response to Pitavastatin Using an Animal Model of Familial Hypercholesterolemia.

Statins are widely used for the treatment of atherosclerotic cardiovascular diseases. They inhibit cholesterol biosynthesis in the liver and cause pleiotropic effects, including anti-inflammatory and antioxidant effects. To develop novel therapeutic drugs, the effect of blood-borne lipid molecules on the pleiotropic effects of statins must be elucidated. Myocardial infarction-prone Watanabe heritable hyperlipidemic (WHHLMI) rabbits, an animal model for hypercholesterolemia, are suitable for the determination of lipid molecules in the blood in response to statins because their lipoprotein metabolism is similar to that of humans. Herein, lipid molecules were investigated by lipidome analysis in response to pitavastatin using WHHLMI rabbits. Various lipid molecules in the blood were measured using a supercritical fluid chromatography triple quadrupole mass spectrometry. Cholesterol and cholesterol ester blood concentrations decreased by reducing the secretion of very low density lipoproteins from the liver. Independent of the inhibition effects of cholesterol biosynthesis, the concentrations of some lipids with anti-inflammation and antioxidant effects (phospholipid molecules with n-6 fatty acid side chains, lysophosphatidylcholines, phosphatidylethanolamine plasmalogens, and ceramide molecules) were significantly altered. These findings may lead to further investigation of the mechanism of statin action.

Effectiveness of 23-Valent Pneumococcal Polysaccharide Vaccine against Invasive Pneumococcal Disease in Adults, Japan, 2013-2017.

The decline in the proportion of pneumococcal conjugate vaccine (PCV)-covered serotypes among adult invasive pneumococcal disease (IPD) patients might change the overall effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) because its effectiveness differs according to serotype. Using the indirect cohort method, we calculated the effectiveness of PPSV23 against IPD among adults in Japan to assess the impact of the national pediatric PCV program. Clinical and epidemiologic information and pneumococcal isolates were collected from IPD patients >20 years of age through enhanced IPD surveillance during April 2013-December 2017. Adjusted effectiveness against PPSV23-serotype IPD was 42.2%. Despite a substantial decline in the proportion of 13-valent PCV serotypes during the study period (45% to 31%), the change in effectiveness for PPSV23-serotype IPD was limited (47.1% to 39.3%) and only marginal in the elderly population (39.9% to 39.4%). The pediatric PCV program had limited impact on PPSV23 effectiveness against IPD in adults.

Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of japanese society of chemotherapy, the japanese association for infectious diseases, and the japanese society for clinical microbiology in 2016: General view of the pathogens' antibacterial susceptibility.

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2016. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between February 2016 and August 2016 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standards Institute. Susceptibility testing was evaluated in 1062 strains (143 Staphylococcus aureus, 210 Streptococcus pneumoniae, 17 Streptococcus pyogenes, 248 Haemophilus influenzae, 151 Moraxella catarrhalis, 134 Klebsiella pneumoniae, and 159 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 48.3%, and those of penicillin-susceptible S. pneumoniae was 99.5%. Among H. influenzae, 14.1% of them were found to be ß-lactamase-producing ampicillin-resistant strains, and 41.1% to be ß-lactamase-non-producing ampicillin-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 4.5% and 0.6%, respectively.

Improved quantitation of lipid classes using supercritical fluid chromatography with a charged aerosol detector.

Quantitatively and rapidly analyzing lipids is necessary to elucidate their biological functions. Herein, we developed a quantitative method for various lipid classes using supercritical fluid chromatography (SFC) coupled with a charged aerosol detector (CAD), providing high-throughput data analysis to detect a large number of molecules in each lipid class as one peak. Applying the CAD was useful for analyzing lipid molecules in the same lipid class with a constant response under the same mobile phase composition. First, we optimized the washing method for the diethylamine column, achieving baseline separation of lipid classes while maintaining good peak shapes. In addition, the CAD conditions (organic solvent evaporation and numerical correction of the CAD data) were optimized to improve the signal-to-noise ratio. We used an internal standard (ceramide phosphoethanolamine d17:1-12:0), which did not coelute with the lipid classes and showed high extraction efficiency. Based on a quantitative analysis of HepG2 cells, the concentration of lipid classes detected by CAD was adequate compared with that obtained by triple-quadrupole MS (QqQMS) in a previous study because the deviations of the concentrations were 0.6- to 2.3-fold. These results also supported the quantitative performance of SFC-QqQMS developed in our previous report.

Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for clinical microbiology in 2014: General view of the pathogens' antibacterial susceptibility.

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2014. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January 2014 and April 2015 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standards Institute. Susceptibility testing was evaluated in 1534 strains (335 Staphylococcus aureus, 264 Streptococcus pneumoniae, 29 Streptococcus pyogenes, 281 Haemophilus influenzae, 164 Moraxella catarrhalis, 207 Klebsiella pneumoniae, and 254 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 43.6%, and those of penicillin-susceptible S. pneumoniae was 100%. Among H. influenzae, 8.2% of them were found to be ß-lactamase-producing ampicillin-resistant strains, and 49.1% to be ß-lactamase-non-producing ampicillin-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 9.2% and 0.4%, respectively.

Widely-targeted quantitative lipidomics method by supercritical fluid chromatography triple quadrupole mass spectrometry.

Lipidomics, the mass spectrometry-based comprehensive analysis of lipids, has attracted attention as an analytical approach to provide novel insight into lipid metabolism and to search for biomarkers. However, an ideal method for both comprehensive and quantitative analysis of lipids has not been fully developed. Here, we have proposed a practical methodology for widely targeted quantitative lipidome analysis using supercritical fluid chromatography fast-scanning triple-quadrupole mass spectrometry (SFC/QqQMS) and theoretically calculated a comprehensive lipid multiple reaction monitoring (MRM) library. Lipid classes can be separated by SFC with a normal-phase diethylamine-bonded silica column with high resolution, high throughput, and good repeatability. Structural isomers of phospholipids can be monitored by mass spectrometric separation with fatty acyl-based MRM transitions. SFC/QqQMS analysis with an internal standard-dilution method offers quantitative information for both lipid class and individual lipid molecular species in the same lipid class. Additionally, data acquired using this method has advantages, including reduction of misidentification and acceleration of data analysis. Using the SFC/QqQMS system, alteration of plasma lipid levels in myocardial infarction-prone rabbits to the supplementation of EPA was first observed. Our developed SFC/QqQMS method represents a potentially useful tool for in-depth studies focused on complex lipid metabolism and biomarker discovery.-Takeda, H., Y. Izumi, M. Takahashi, T. Paxton, S. Tamura, T. Koike, Y. Yu, N. Kato, K. Nagase, M. Shiomi, and T. Bamba.

Impaired Secretion of Glucagon-Like Peptide 1 in Patients with Colorectal Adenoma after an Oral Glucose Load.

BACKGROUND/AIMS: Obesity and insulin resistance are associated with an increased risk of colorectal adenoma (CRA). Glucagon-like peptide-1 (GLP-1) plays an important role in glucose homeostasis through its amplification of insulin secretion in response to oral nutrients; however, its role in human CRA remains unknown. We investigated oral glucose-mediated GLP-1 secretion in patients with adenoma. METHODS: We performed a case-control study of 15 nondiabetic patients with pathologically diagnosed CRA and 10 age-matched healthy controls without adenoma. Plasma concentrations of active GLP-1 were measured during a 75 g oral glucose tolerance test. RESULTS: Mean waist circumference (WC), homeostasis model assessment of insulin resistance (HOMA-IR) values, the total areas under the curve (AUC) of glucose and insulin were significantly higher in patients with CRA than in controls. The total AUC of GLP-1 (p = 0.01) was lower in patients with CRA than in controls. Moreover, the total AUC of GLP-1 showed a negative correlation with WC, total AUC of glucose, and HOMA-IR. Multiple linear regression analyses revealed that the total AUC of GLP-1 was independently correlated with the number and maximum size of CRAs. CONCLUSION: GLP-1 could actively participate in the development of CRA in humans, particularly in patients with metabolic syndrome.

IL-15 and RANKL Play a Synergistically Important Role in Osteoclastogenesis.

Interleukin-15 (IL-15), a cytokine secreted by several cell types, has important physiological roles in the activity, proliferation, and viability of immune cells. It has both chemoattractant and proinflammatory properties, and may promote bone destruction. A previous study has shown that IL-15 alone exerts no effect on osteoclastogenesis. Therefore, the current study addressed the synergistic effect of IL-15 on osteoclast formation using RAW264.7 (RAW) cells by co-stimulation with receptor activator of nuclear factor (NF)-κB ligand (RANKL) that has a major role in osteoclastogenesis involving the pathogenesis of rheumatoid arthritis and periodontal disease. Co-stimulation of RAW cells by IL-15 and RANKL significantly increased the gene expression of osteoclast differentiation and osteoclastogenesis markers compared with stimulation by RANKL or IL-15 independently as evaluated by tartrate-resistant acid phosphate-positive cell numbers, the fusion index, a pit formation assay with Alizarin red staining (calcification estimation), and quantitative polymerase chain reaction. Phosphorylation of extracellular signal-regulated kinase (ERK), c-jun N-terminal kinase, p38 mitogen-activated protein kinase, and NF-κB was significantly increased by RANKL and IL-15 (P < 0.05) compared with RANKL alone. In addition, these differentiation activities induced by RANKL and IL-15 were comparatively suppressed by inhibition of ERK, suggesting that this synergistic effect on osteoclastogenesis is mainly mediated by ERK. Taken together, our results demonstrate that IL-15 and RANKL induce osteoclastogenesis synergistically, and IL-15 might play a novel and major role in destructive inflammatory bone diseases. J. Cell. Biochem. 118: 739-747, 2017. © 2016 Wiley Periodicals, Inc.

Invasive pneumococcal disease among adults in Japan, April 2013 to March 2015: disease characteristics and serotype distribution.

BACKGROUND: In Japan, the clinical characteristics and recent serotype distribution among adult patients of invasive pneumococcal disease (IPD) have not been fully investigated since the introduction of the pneumococcal conjugate vaccine (PCV) in children. From November 2010, PCV7 was encouraged by an official program, funded by government, subsequently included in the routine schedule in April 2013, and replaced with a PCV13 in November 2013. METHODS: Between April 2013 and March 2015, patients with IPD older than 15 years were evaluated based on the enhanced national surveillance in ten prefectures of Japan. The serotype distribution of the isolates was analyzed in these patients. RESULTS: The analysis included 291 patients: 107 patients (37%) were female and the median age was 70 years. Of 281 patients with available data, 202 (72%) had underlying diseases, including 107 patients (38%) with immunocompromised status. The case fatality proportion for all case was 20%. In subgroup analysis, the case fatality proportion (29%) in immunocompromised patients was much higher than that (0-16%) in each age group of nonimmunocompromised patients (15-39 years, 40-64 years, and ≥ 65 years). While the proportion of bacteremia without any focus (27%) was higher than that (8-10%) in nonimmunocompromised patients, the proportions of vaccine types (PCV13, 32%; PPSV23, 51%) of the causative isolates were lower than those in each age group of nonimmunocompromised patients. Among 291 isolates, the most frequent serotypes were 3 (17%), 19A (13%), and 22F (10%). Twelve percent of the isolates were PCV7 serotypes, 46% were PCV13 serotypes, and 66% were PPSV23 serotypes. CONCLUSIONS: The majority of adult patients of IPD had underlying diseases, including immunocompromised conditions. A low proportion (12%) of PCV7-type IPD was observed in this population where PCV7 for children had been included in the routine immunization schedule.

Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2012: General view of the pathogens' antibacterial susceptibility.

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from the patients in Japan was conducted by Japanese Society of Chemotherapy, Japanese association for infectious diseases and Japanese society for Clinical Microbiology in 2012. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period between January and December in 2012 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical Laboratory Standard Institutes. Susceptibility testing was evaluated in 1236 strains (232 Staphylococcus aureus, 225 Streptococcus pneumoniae, 16 Streptococcus pyogenes, 231 Haemophilus influenzae, 147 Moraxella catarrhalis, 167 Klebsiella pneumoniae and 218 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was 51.3%, and those of penicillin-intermediate S. pneumoniae was 0.4%. Among H. influenzae, 5.6% of them were found to be ß-lactamase-producing ampicillin-resistant strains, and 37.2% to be ß-lactamase-non-producing ampicillin-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 4.2% and 3.2%, respectively. Continuous national surveillance is important to determine the actual situation of the resistance shown by bacterial respiratory pathogens to antimicrobial agents.

Structure-based development and optimization of therapy antibody drugs against TNFα.

Previously, we reported on the crystal structures of the Fab fragments of two food and drug administration approved therapeutic antibodies, Infliximab and Adalimumab, in complex with TNFα. The structurally identified epitopes on TNFα reveal the mechanism of TNFα inhibition by partially overlapping with the TNFα-receptor interface. In this study, we launched a screen of a phage display library to isolate novel anti-TNFα antibodies based on the adalimumab epitope. Structural analysis, the phage display antibody isolation technology, step-by-step antibody optimization, complementarity-determining region residues random mutagenesis, phage ELISA, binding affinity characterization, and cell signaling assays were used for the development and optimization of the novel anti-TNFα antibodies. Moreover, one of the novel antibodies, hAta09, has a superior inhibitory effect on TNFα function and signaling. Taken together, our report established that the novel anti-TNFα antibody hAta09 may achieve clinical efficacy in a TNFα-associated disease.

Nationwide surveillance of bacterial respiratory pathogens conducted by the surveillance committee of Japanese Society of Chemotherapy, the Japanese Association for Infectious Diseases, and the Japanese Society for Clinical Microbiology in 2010: General view of the pathogens' antibacterial susceptibility.

The nationwide surveillance on antimicrobial susceptibility of bacterial respiratory pathogens from patients in Japan, was conducted by Japanese Society of Chemotherapy, Japanese Association for Infectious Diseases and Japanese Society for Clinical Microbiology in 2010. The isolates were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections during the period from January and April 2010 by three societies. Antimicrobial susceptibility testing was conducted at the central reference laboratory according to the method recommended by Clinical and Laboratory Standard Institutes using maximum 45 antibacterial agents. Susceptibility testing was evaluable with 954 strains (206 Staphylococcus aureus, 189 Streptococcus pneumoniae, 4 Streptococcus pyogenes, 182 Haemophilus influenzae, 74 Moraxella catarrhalis, 139 Klebsiella pneumoniae and 160 Pseudomonas aeruginosa). Ratio of methicillin-resistant S. aureus was as high as 50.5%, and those of penicillin-intermediate and -resistant S. pneumoniae were 1.1% and 0.0%, respectively. Among H. influenzae, 17.6% of them were found to be ß-lactamase-non-producing ampicillin (ABPC)-intermediately resistant, 33.5% to be ß-lactamase-non-producing ABPC-resistant and 11.0% to be ß-lactamase-producing ABPC-resistant strains. Extended spectrum ß-lactamase-producing K. pneumoniae and multi-drug resistant P. aeruginosa with metallo ß-lactamase were 2.9% and 0.6%, respectively. Continuous national surveillance of antimicrobial susceptibility of respiratory pathogens is crucial in order to monitor changing patterns of susceptibility and to be able to update treatment recommendations on a regular basis.

Treatment with anti-interleukin-6 receptor antibody ameliorates intestinal polyposis in Apc(Min/+) mice under high-fat diet conditions.

The prevalence of colorectal malignancies is increasing in the world. The parallel increase of metabolic syndrome gives a speculation between these two conditions, although the precise mechanism is still unclear. Interleukin-6 (IL-6) is a cytokine known to correlate with obesity and serve as a proinflammatory adipokine. In the present study, we investigated the effect of IL-6 signaling blockade on intestinal polyp formation in obesity using a mouse model of adenomatous polyposis coli (Apc). Male C57BL/6J-Apc(Min/+) mice were fed a high-fat diet from 5 weeks of age, and the overweight mice thus obtained were given a weekly intraperitoneal injection of anti-mouse IL-6 receptor antibody (MR16-1) from 6 to 15 weeks of age, while control mice received IgG or phosphate-buffered saline (PBS). The total number of intestinal polyps was significantly decreased in the MR16-1-injected group (53.1 ± 6.8) relative to the control groups (PBS-injected, 81.3 ± 6.1; rat IgG-injected, 74.7 ± 4.8, p = 0.01), and in particular the number of polyps larger than 2 mm in diameter was markedly decreased. In addition, the mean diameter of polyps in the MR16-1-injected group was significantly smaller than that in the control groups. On the other hand, no significant differences in body weight, epididymal fat pad mass, or the plasma levels of glucose, insulin and triglyceride were observed among the three groups. Thus, treatment with anti-IL-6 receptor antibody suppressed polyp growth in obese Apc(Min/+) mice fed the high-fat diet. We suggest that IL-6 signaling may be responsible for the obesity-associated colorectal tumorigenesis.

A case of pneumonia caused by Legionella pneumophila serogroup 12 and treated successfully with imipenem.

The patient was an 83-year-old man hospitalized for Haemophilus influenzae pneumonia, who developed recurrent pneumonia after improvement of the initial episode. Legionella pneumophila serogroup 12 was isolated from the sputum, accompanied by increased serum antibody titers to L. pneumophila serogroup 12. Therefore, the patient was diagnosed as having Legionella pneumonia caused by L. pneumophila serogroup 12. Case reports of pneumonia caused by L. pneumophila serogroup 12 are rare, and the case described herein is the first report of clinical isolation of this organism in Japan. When the genotype was determined by the protocol of The European Working Group for Legionella Infections (Sequence-Based Typing [SBT] for epidemiological typing of L. pneumophila, Version 3.1), the sequence type was ST68. Imipenem/cilastatin therapy was found to be effective for the treatment of Legionella pneumonia in this patient.

Increased secretion of insulin and proliferation of islet ß-cells in rats with mesenteric lymph duct ligation.

BACKGROUND & AIMS: It has been suggested that intestinal lymph flow plays an important role in insulin secretion and glucose metabolism after meals. In this study, we investigated the influence of ligation of the mesenteric lymph duct on glucose metabolism and islet ß-cells in rats. METHODS: Male Sprague-Dawley rats (10 weeks old) were divided into two groups: one underwent ligation of the mesenteric lymph duct above the cistern (ligation group), and the other underwent a sham operation (sham group). After 1 and 2 weeks, fasting plasma concentrations of glucose, insulin, triglyceride, glucose-dependent insulinotropic polypeptide (GIP), and the active form of glucagon-like peptide-1 (GLP-1) were measured. At 2 weeks after the operation, the oral glucose tolerance test (OGTT) and intravenous glucose tolerance test (IVGTT) were performed. After the rats had been sacrificed, the insulin content of the pancreas was measured and the proliferation of ß-cells was assessed immunohistochemically using antibodies against insulin and Ki-67. RESULTS: During the OGTT, the ligation group showed a significant decrease in the plasma glucose concentration at 120 min (p<0.05) and a significant increase in the plasma insulin concentration by more than 2-fold at 15 min (p<0.01). On the other hand, the plasma GIP concentration was significantly decreased at 60 min (p<0.01) in the ligated group, while the active form of GLP-1 showed a significantly higher level at 90 min (1.7-fold; p<0.05) and 120 min (2.5-fold; p<0.01). During the IVGTT, the plasma insulin concentration in the ligation group was significantly higher at 2 min (more than 1.4-fold; p<0.05). Immunohistochemistry showed that the ratios of ß-cell area/acinar cell area and ß-cell area/islet area, and also ß-cell proliferation, were significantly higher in the ligation group than in the sham group (p<0.05, p<0.01 and p<0.01, respectively). The insulin content per unit wet weight of pancreas was also significantly increased in the ligation group (p<0.05). CONCLUSIONS: In rats with ligation of the mesenteric lymph duct, insulin secretion during the OGTT or IVGTT was higher, and the insulin content and ß-cell proliferation in the pancreas were also increased. Our data show that mesenteric lymph duct flow has a role in glucose metabolism.