The nationwide surveillance of antibacterial susceptibility to meropenem (MEPM) and other parenteral antibiotics against clinical isolates during 2012 in Japan was conducted. A total of 2985 strains including 955 strains of Gram-positive bacteria, 1782 strains of Gram-negative bacteria, and 248 strains of anaerobic bacteria obtained from 31 medical institutions were examined. The results were as follows; 1. MEPM was more active than the other carbapenem antibiotics tested against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MEPM was also active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus (MRSA). 2. Of all species tested, there were no species, which MIC90 of MEPM was more than 4-fold higher than those in our previous studies in 2009 or 2006. Therefore, the tendency to increase in antimicrobial resistance rates was not observed. 3. MEPM resistance against Pseudomonas aeruginosa was 17.8% (56/315 strains). Compared to our previous results, it was the lowest than that in 2006 and 2009. 4. Carbapenem-resistant Klebsiella pneumoniae, and multi-drug-resistant Acinetobacter species, which emerged in worldwide, were not observed. 5. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 6.2% (59/951 strains) in enterobacteriaceae, which increased compared with that of our previous studies in 2009 or before. Whereas, the proportion of metallo-beta-lactamase strains was 1.6% (5/315 strains) in P. aeruginosa, which was stable. In conclusion, the results from this surveillance suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem for serious infections treatment at present, 17 years passed after available for commercial use in Japan.
This study investigated a new method of flow cytometry (FCM) for analysis of red blood cell (RBC) osmotic fragility. Venous peripheral blood collected in a sampling tube coated with EDTA 2Na was analyzed using FCM to determine RBC osmotic fragility. RBCs were represented as a double-peaked forward scatter (FSC) histogram in FCM. RBCs showed ballooning and spherical shape change in hypotonic solutions before hemolysis. The ballooning of RBCs was expressed as a disappearance of the minor peak and by narrowing and a shift to the right of the FSC histogram. The process of hemolysis was expressed as shrinking of the RBC cytogram in the right upper quadrant on the scatter plot of side scatter versus FSC and by emergence of a cell debris cytogram in the left lower quadrant. The ratio of intact RBCs in hypotonic solution was available as an indicator of osmotic fragility. Acidic solution made erythrocytes less tolerant to hypotonic solution by inducing spherical shape change. In conclusion, FCM can be used to assess RBC osmotic fragility.
Sexual dimorphism in asthma links the estrogen and allergic immune responses. The function of estrogen was classically believed to be mediated through its nuclear receptors, i.e., estrogen receptors (ERs). However, recent studies established the important roles of G-protein-coupled estrogen receptor (GPER/GPR30) as a novel membrane receptor for estrogen. To date, the role of GPER in allergic inflammation is poorly understood. The purpose of this study was to examine whether GPER might affect the functions of eosinophils, which play an important role in the pathogenesis of asthma. Here, we demonstrated that GPER was expressed in purified human peripheral blood eosinophils both at the mRNA and protein levels. Although GPER agonist G-1 did not induce eosinophil chemotaxis or chemokinesis, preincubation with G-1 enhanced eotaxin (CCL11)-directed eosinophil chemotaxis. G-1 inhibited eosinophil spontaneous apoptosis and caspase-3 activities. The anti-apoptotic effect was not affected by the cAMP-phospodiesterase inhibitor rolipram or phosphoinositide 3-kinase inhibitors. In contrast to resting eosinophils, G-1 induced apoptosis and increased caspase-3 activities when eosinophils were co-stimulated with IL-5. No effect of G-1 was observed on eosinophil degranulation in terms of release of eosinophil-derived neurotoxin (EDN). The current study indicates the functional capacities of GPER on human eosinophils and also provides the previously unrecognized mechanisms of interaction between estrogen and allergic inflammation.
Activities and the understanding of infection control in healthcare facilities have improved in the past decade since a certification system for medical personnel, such as infection control nurse and infection control doctor, were introduced in Japan. These specialists are distributed among tertiary general hospitals, while many small and mid-scale hospitals have no infection control specialists. In 2012, the Japanese Ministry of Health, Labour and Welfare launched a new strategy for further improvement of infection control by supporting a regional network of infection control activities. Through the infection control network, small or mid-scaled hospitals can utilize infection control specialists in tertiary general hospitals, enter educational programs on infection control and consult in cases of nosocomial infection outbreaks. As part of the regional infection control network, we established an information network system, named ReNICS, to share the bacteriological test results of the hospitals in Akita prefecture. ReNICS offers epidemiological data on bacteria identified in the region. We can identify the spread of multi-drug resistant bacteria and can roughly estimate the quality of infection control activities in each facility. As a similar information network is being prepared in Hirosaki University Hospital Infection Control Center in Aomori, a prefecture neighboring Akita, we discussed the roles of university hospitals for a regional infection control network.
Epidemiological studies have shown that the prevalence of adult asthma and severe asthma is higher in women. It has also been reported that female mice are more susceptible than males to the development of allergic airway inflammation and airway hyperresponsiveness (AHR). The influence of gender difference in the pathogenesis of severe asthma, especially airway remodelling in an animal model, has been studied rarely. We investigated gender difference in the development of airway remodelling using a long-term antigen-challenged mouse asthma model.
A 76-year-old male diagnosed with interstitial pneumonia in December 2002 was treated with a steroid in a nearby hospital. Exacerbation of infectious pneumonitis and interstitial pneumonia required complementary inpatient treatment in August 2007. Although polymerase chain reaction examination of expectorated sputa revealed the absence of Mycobacterium tuberculosis, M. avium, and M. intracellulare on admission, nontuberculous M. abscessus was detected in the routine blood cultures. Taken together with clinical findings, M. abscessus was most likely the primary causative organism. Diagnosis of mycobaterium-induced septicemia generally involves the use of mycobacterium-designated bottles, MGIT method, and Ogawa medium; however, we used microbe cultures with routine blood-culture bottles in the present case. Of the 24 mycobacterium-induced septicemia cases reported in the past 10 years, only eight cases were detected from routine blood-culture bottles; they were all rapidly growing bacteria. Mycobacteria other than the rapidly growing mycobacteria display delayed culture proliferation, therefore it is possible that non-detected microbes were probably present in the patients despite the fact that they were suffering from septicemia. In cases suspected to have severe infections, particularly those with a depressed immunodefense system, blood-culture testing for mycobacteria would be highly helpful for diagnosis.
The active involvement of hospital laboratory in surveillance is crucial to the success of nosocomial infection control. The recent dramatic increase of antimicrobial-resistant organisms and their spread into the community suggest that the infection control strategy of independent medical institutions is insufficient. To share the clinical data and surveillance in our local medical region, we developed a microbiology data warehouse for networking hospital laboratories in Akita prefecture. This system, named Akita-ReNICS, is an easy-to-use information management system designed to compare, track, and report the occurrence of antimicrobial-resistant organisms. Participating laboratories routinely transfer their coded and formatted microbiology data to ReNICS server located at Akita University Hospital from their health care systems clinical computer applications over the internet. We established the system to automate the statistical processes, so that the participants can access the server to monitor graphical data in the manner they prefer, using their own computers browser. Furthermore, our system also provides the documents server, microbiology and antimicrobiotic database, and space for long-term storage of microbiological samples. Akita-ReNICS could be a next generation network for quality improvement of infection control.
Thioredoxin (TRX) is a redox-active protein that regulates reactive oxidative metabolism and plays a crucial role in the antioxidant system in regulating the reduction/oxidation balance by scavenging reactive oxygen species, which is implicated in the mechanism of asthma. As for the mechanisms by which TRX exerts its beneficial effects, some studies have shown that TRX suppresses allergic inflammation in animal models of asthma. Recently, we reported that TRX directly modulated the chemotaxis of eosinophils, which have been shown to play a pivotal role in the mechanism of allergic airway inflammation, in the absence of T helper (Th)1 or Th2 cytokines. Further, serum TRX levels in patients with asthma were significantly increased in patients with attacks compared with those in the asymptomatic period. This review focuses on TRX in allergic reactions and discusses the physiological role of TRX.
Tissue eosinophilia is one of the hallmarks of allergic diseases and Th2-type immune responses including asthma. Systemic inflammation caused by adipose tissue in obesity via production of adipokines such as leptin has been attracting attention recently as a contributor to exacerbation of allergic immune reactions. In this study, we examined whether leptin might affect eosinophil chemotactic responses.
Prostaglandin D2 (PGD2) regulates various immunological responses via two distinct PGD2 receptors, prostaglandin D receptor (DP), and chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2). Recent studies have demonstrated that PGD2 induces the migration of eosinophils through CRTH2. Although human eosinophils express both DP and CRTH2, it is unclear whether the function of DP is involved in eosinophil migration.
Hepatocyte growth factor (HGF) has multiple activities in a variety of tissues, and is known to prevent the onset and progression of various diseases, but the mechanisms by which HGF exert its beneficial effects remain to be elucidated, although many studies have shown that HGF exerts anti-inflammatory effects in multiple animal models of diseases of the liver, kidney, lung and other organs. Recently, we have reported that HGF also reduces allergic airway inflammation in a murine model of asthma by ovalbumin. Furthermore, HGF directly modulates various functions of eosinophils, which have been shown to play a pivotal role in the development of allergic airway inflammation. HGF influences a number of cell types, and regulates various biological activities, including cytokine production, cell migration, proliferation and survival. This review focuses on the effect of HGF on various inflammatory cells, e.g. eosinophils and dendritic cells, in allergic reactions.
Phosphoinositide 3-kinases (PI3Ks) are known to be involved in a variety of cellular responses such as cell survival, proliferation, differentiation and cell migration. Recently, PI3Ks have been associated with the pathogenesis of asthma because various immune cells regulate allergic responses. Among the three classes of PI3Ks, the roles of PI3K gamma and PI3K delta in allergic responses have attracted particular attention. In a previous report, allergic airway hyperresponsiveness (AHR), inflammation and airway remodeling in an ovalbumin-induced asthma model were decreased in PI3K gamma-deficient mice compared with wild-type mice. In addition, AHR and inflammation were attenuated by administration of a selective PI3K delta inhibitor in a murine model of asthma. These results indicate that PI3K gamma and PI3K delta may be new therapeutic targets for asthma. However, PI3K gamma and PI3K delta may differ in terms of the mechanism of regulation. In this review, we focus on the roles of PI3K gamma and PI3K delta in the pathogenesis of asthma and discuss the mechanistic differences between PI3K gamma and PI3K delta.
Infection control is essential for health care facilities. Aiming at improving the activity for infection control, increasing number of health care facilities has settled infection control team (ICT) in this decade. However, the quality of infection control activity has not been evaluated.
15-Deoxy-Delta(12,14)-prostaglandin J2 (15d-PGJ2), a major prostanoid metabolized from prostaglandin D2 (PGD2), plays an important role in various biological processes including inflammatory responses. 15d-PGJ2 exerts its effects through two major receptors, chemoattractant receptor- homologous molecule expressed on Th2 cells (CRTH2) and peroxisome proliferator-activated receptor-gamma (PPARgamma). The 15d-PGJ2/PPARgamma system, in particular, regulates numerous biological processes including adipogenesis, apoptosis, and inflammation. Although our studies have shown that PGD2 (metabolic precursor of 15d-PGJ2) induces IL-8 and GM-CSF production, the role of 15d-PGJ2 (metabolite of PGD2) is unknown in human bronchial epithelial cells. In this study, we investigated the function of 15d-PGJ2 on a human airway epithelial cell line: NCI-H292.
Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a nuclear receptor that regulates not only adipogenesis but also immune reaction. We previously demonstrated that human eosinophils expressed functional PPARgamma, although the modulator of PPARgamma expression is less well understood. Because clinical studies have shown that the efficacy of PPARgamma agonists as insulin sensitizers is stronger in women than in men, we investigated whether sex hormones caused any changes in eosinophil PPARgamma expression levels.
Bronchial asthma is characterized by chronic airway inflammation caused by inflammatory cells. Phosphoinositide 3-kinases (PI3Ks) are known to play a prominent role in fundamental cellular responses of various inflammatory cells, including proliferation, differentiation, and cell migration. PI3Ks therefore are expected to have therapeutic potential for asthma. Although some investigations of the involvement between the pathogenesis of asthma and PI3K have been performed, it is unknown whether PI3Kgamma, a PI3K isoform, is involved in the pathogenesis of asthma.
Interactions between eosinophils and monocytes after lipopolysaccharide inhalation are yet to be investigated. The mechanism of eosinophil activation induced by lipopolysaccharide in the presence of monocytes was investigated.
In Japan, laboratory automation has spread over the last two decades. Laboratory automation has saved time and labor for routine sample tests in clinical laboratories, and contributed to the downsizing of the division. This "contribution" resulted in re-arrangement of the work-force, namely, shrinkage of the blood chemistry division and expansion of the physiological tests and diagnostic imaging division. Some may call this re-arrangement as an adaptation for survival. However, I am concerned that extreme adaptation may cause irreversible shrinkage of clinical laboratories and laboratory medicine itself. In fact, outsourcing of sample tests including microbiological tests has become very popular over the last decade. Since the cost for microbiological tests is suppressed by the national health insurance policy, it is becoming difficult to keep microbiological laboratories in small-scale hospitals. The presence of a microbiological laboratory in a hospital is crucial for prompt and appropriate therapies for infectious diseases, and is essential for advanced infection control activities. The government is pushing forward fixed-term employment in national universities and hospitals, threatening long-term career planning for medical technologists. We have to keep in mind that nurturing medical personnel with special skills and extensive knowledge is mandatory to university hospitals, and laboratory medicine is crucial to the progress of modern medicine.
It has been pointed out that obesity is a risk factor for, and is involved in the exacerbation of asthma. Mounting evidence about adipose tissue-derived proteins (adipokines) gave rise to the current understanding of obesity as a systemic inflammatory disorder. In this review, we summarized the involvement of leptin, focusing on eosinophil functions. Several studies have indicated that leptin can restrain eosinophil apoptosis, enhance migration, increase adhesion molecules and induce cytokine production. Since leptin also acts on a variety of immune cells related to allergic response, increased leptin in obese individuals potentially explains the mechanism by which obesity leads to an exacerbation of asthma. Further studies targeting adipokines will delineate the association between obesity and eosinophil-associated diseases.
Despite the fact that previous studies have indicated the significant roles of polyunsaturated fatty acids (PUFAs) in the immune system through peroxisome proliferator-activated receptor alpha (PPAR?) and PPAR?, the biological functions and the mechanisms of action in eosinophils are poorly understood.
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