Aggregated eosinophils and neutrophils characterize the properties of mucus in chronic rhinosinusitis.

BACKGROUND: Airway obstruction caused by viscous mucus is an important pathophysiologic characteristic of persistent inflammation, which can result in organ damage. OBJECTIVE: We investigated the hypothesis that the biophysical characteristics of accumulating granulocytes affect the clinical properties of mucus. METHODS: Surgically acquired nasal mucus samples from patients with eosinophilic chronic rhinosinusitis and neutrophil-dominant, noneosinophilic chronic rhinosinusitis were evaluated in terms of computed tomography density, viscosity, water content, wettability, and protein composition. Isolated human eosinophils and neutrophils were stimulated to induce the formation of extracellular traps, followed by the formation of aggregates. The biophysical properties of the aggregated cells were also examined. RESULTS: Mucus from patients with eosinophilic chronic rhinosinusitis had significantly higher computed tomography density, viscosity, dry weight, and hydrophobicity compared to mucus from patients with noneosinophilic chronic rhinosinusitis. The levels of eosinophil-specific proteins in mucus correlated with its physical properties. Eosinophil and neutrophil aggregates showed physical and pathologic characteristics resembling those of mucus. Cotreatment with deoxyribonuclease and heparin, which slenderizes the structure of eosinophil extracellular traps, efficiently induced reductions in the viscosity and hydrophobicity of both eosinophil aggregates and eosinophilic mucus. CONCLUSIONS: The present study elucidated the pathogenesis of mucus stasis in infiltrated granulocyte aggregates from a novel perspective. These findings may contribute to the development of treatment strategies for eosinophilic airway diseases.

How to detect eosinophil ETosis (EETosis) and extracellular traps.

Eosinophils are short-lived and comprise only a small population of circulating leukocytes; however, they play surprisingly multifunctional roles in homeostasis and various diseases including allergy and infection. Recent research has shed light on active cytolytic eosinophil cell death that releases eosinophil extracellular traps (EETs) and total cellular contents, namely eosinophil extracellular trap cell death (EETosis). The pathological contribution of EETosis was made more cogent by recent findings that a classical pathological finding of eosinophilic inflammation, that of Charcot-Leyden crystals, is closely associated with EETosis. Currently no gold standard methods to identify EETosis exist, but "an active eosinophil lysis that releases cell-free granules and net-like chromatin structure" appears to be a common feature of EETosis. In this review, we describe several approaches that visualize EETs/EETosis in clinical samples and in vitro studies using isolated human eosinophils. EETs/EETosis can be observed using simple chemical or fluorescence staining, immunostaining, and electron microscopy, although it is noteworthy that visualization of EETs is greatly changed by sample preparation including the extracellular space of EETotic cells and shear flow. Considering the multiple aspects of biological significance, further study into EETs/EETosis is warranted to give a detailed understanding of the roles played in homeostasis and disease pathogenesis.

Fructo-oligosaccharides ameliorate steatohepatitis, visceral adiposity, and associated chronic inflammation via increased production of short-chain fatty acids in a mouse model of non-alcoholic steatohepatitis.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome. Within the spectrum of NAFLD, non-alcoholic steatohepatitis (NASH) in combination with hepatic inflammation and fibrosis can lead to liver cirrhosis and hepatocellular carcinoma. Dysbiosis was reported to contribute to NASH pathogenesis. This study aimed to determine the effects of fructo-oligosaccharides (FOS) on steatohepatitis and visceral adiposity in an obese mouse model of NASH. METHODS: Twelve newborn C57BL/6 J male mice were subcutaneously injected with monosodium glutamate (MSG) to induce obesity on a conventional diet. Six mice were also administered 5% FOS via drinking water from 10 weeks of age. At 18 weeks, histological characteristics of the liver and epididymal fat were compared between the groups. Hepatic mRNA expression of lipid metabolism enzymes and SCFA in feces and sera were measured. RESULTS: Hepatic steatosis, inflammatory cell infiltration, and hepatocyte ballooning in the liver and increased hepatic mRNA expression of fatty acid synthase and glycerol-3-phosphate acyltransferase were observed in the MSG-treated mice. FOS treatment improved the liver pathology and blunted the increases in the mRNA expression levels of lipid metabolism enzymes. In addition, FOS inhibited adipocyte enlargement and formation of crown-like structures and reduced the M1 macrophage frequency in the epididymal fat of the MSG mice (39.4% ± 3.0% vs. 22.8% ± 0.7%; P = 0.001). FOS increased not only the fecal concentrations of n-butyric acid (0.04 ± 0.01 vs. 0.38 ± 0.14 mg/g, P = 0.02), propionic acid (0.09 ± 0.03 vs. 0.42 ± 0.16 mg/g, P = 0.02), and acetic acid (0.65 ± 0.16 vs. 1.48 ± 0.29 mg/g, P = 0.03) but also the serum concentration of propionic acid (3.9 ± 0.5 vs. 8.2 ± 0.5 µmol/L, P = 0.001). CONCLUSIONS: FOS ameliorates steatohepatitis, visceral adiposity, and chronic inflammation by increasing SCFA production.

Distinguishing coagulase-negative Staphylococcus bacteremia from contamination using blood-culture positive bottle detection pattern and time to positivity.

AIM: Detection of coagulase-negative Staphylococcus in blood culture may be a result of either bacteremia or contamination. This often leads to diagnostic uncertainly. Our objective was to develop a method for differentiating whether a coagulase-negative Staphylococcus sp. positive blood culture represents bacteremia or contamination based on positive bottle detection pattern and time to positivity (TTP). METHODS: This study included 155 and 51 adults with positive blood cultures for Staphylococcus epidermidis and Staphylococcus hominis, respectively, over a three-year period from 2016 to 2018. Positive blood culture cases were categorized as either bacteremia or contamination based on the clinically available information, and the detection pattern and TTP in each category were investigated. RESULTS: A total of 57, 92, and 6 S. epidermidis positive blood cultures were categorized as bacteremia, contamination, and undetermined, respectively, whereas 15 and 36 S. hominis positive blood cultures were categorized as bacteremia and contamination, respectively. For positive blood cultures categorized as bacteremia, all four bottles in two sets of blood cultures were positive in 47/47 S. epidermidis and 14/14 S. hominis, respectively, whereas either one bottle in each of two sets or three bottles in two sets were positive in 10/19 S. epidermidis and 1/4 S. hominis, respectively; most of those TTPs were <48 h. Among them, the TTP in catheter-related blood stream infection was <24 h. CONCLUSION: Although clinical assessment is crucial to differentiate between bacteremia and contamination, a combination of positive bottle detection pattern and TTP is a valuable diagnostic auxiliary tool.

Umbilical catheterization training: Tissue hybrid versus synthetic trainer.

BACKGROUND: This study of umbilical catheterization deliberate practice training compared skill and knowledge outcomes of umbilical catheterization using a tissue-hybrid simulator (REAL) versus a synthetic simulated umbilical cord task trainer (ART). METHODS: This was a prospective randomized control study. Pediatric residents were randomized to REAL or ART umbilical catheterization deliberate practice training. Pre-post-training changes in skill performance and knowledge scores for REAL and ART groups were compared. Fidelity of REAL and ART were compared by neonatologists. RESULTS: Twenty-seven pediatric residents completed training. Post-training mean skill scores were improved compared to pre-test scores (REAL, P < 0.001; ART, P < 0.0001). Post-training skill, knowledge, and self-efficacy scores were not different between the REAL and ART groups. Fidelity of REAL was higher than ART for neonatologists (P < 0.01). CONCLUSIONS: The face validity of REAL was superior to ART, but resident umbilical cord deliberate practice training demonstrated no difference in skill, knowledge, and self-efficacy improvements between REAL and ART. Further studies on real patients are needed to evaluate the impact of using real or simulated umbilical cords for umbilical venous catheter/umbilical arterial catheter training.

Eosinophil extracellular trap cell death-derived DNA traps: Their presence in secretions and functional attributes.

BACKGROUND: Activated human eosinophils, as well as neutrophils, can release extracellular chromatin to form DNA traps through cytolytic extracellular trap cell death (ETosis). Although formations of neutrophil DNA traps are recognized in patients with various inflammatory conditions, neither the presence of ETosis-derived eosinophil DNA traps in human allergic diseases nor the characteristics of these DNA traps have been studied. OBJECTIVE: We investigated the presence of ETosis-derived DNA traps in eosinophil-rich sinus and ear secretions and the functional attributes of ETosis DNA traps. METHODS: Eosinophil-rich secretions obtained from patients with eosinophilic chronic rhinosinusitis and eosinophilic otitis media were studied microscopically. In vitro studies of ETosis and DNA trap formation used blood-derived eosinophils and neutrophils, and studies of the binding capacities of DNA traps used labeled bacteria and fluorescent microbeads. Stabilities of DNA traps were evaluated by using fluorescence microscopy. RESULTS: Abundant nuclear histone H1-bearing DNA traps formed in vivo in the eosinophilic secretions and contributed to their increased viscosity. In vitro, after brief shear flow, eosinophil ETosis-elicited DNA traps assembled to form stable aggregates. Eosinophil DNA traps entrapped bacteria and fungi and, through hydrophobic interactions, microbeads. In comparison with neutrophil-derived DNA traps, eosinophil DNA traps ultrastructurally exhibited thicker fibers with globular structures and were less susceptible to leukocyte-derived proteolytic degradation, likely because of the lesser protease activities of eosinophils. CONCLUSIONS: In human allergic diseases local cytolysis of eosinophils not only releases free eosinophil granules but also generates nuclear-derived DNA traps that are major extracellular structural components within eosinophil-rich secretions.

The effect of hepatocyte growth factor on secretory functions in human eosinophils.

Hepatocyte growth factor (HGF), originally identified as a potent mitogen for mature hepatocytes, is now recognized as a humoral mediator in inflammatory and immune responses. Previous studies indicated that HGF negatively regulated allergic airway inflammation. In view of eosinophils playing a role in the pathogenesis of asthma, especially in airway remodeling as a rich source of pro-fibrogenic mediators, the effects of HGF on the different types of eosinophil secretory functions were examined in this study. We found that HGF significantly inhibited IL-5-induced secretion of TGF-ß and VEGF from human eosinophils. The inhibitory effect is not associated with TGF-ß transcription; rather, it is associated with ultrastructural granule emptying and loss of intracellular TGF-ß contents, indicating HGF inhibits the process of piecemeal degranulation. The effect of HGF on extracellular trap cell death (ETosis) that mediates cytolytic degranulation was also investigated; however, immobilized IgG- or phorbol myristate acetate-induced ETosis was only minimally attenuated by HGF. These results reveal the effect of HGF on the distinct pathways of eosinophil secretory functions and also provide novel insights into the role of HGF in the pathogenesis of allergic inflammation.

The effect of pharmacological PI3Kγ inhibitor on eotaxin-induced human eosinophil functions.

BACKGROUND: Asthma is characterized by chronic inflammation caused by activation of immune cells including Th2 lymphocytes and eosinophils. Phosphoinositide 3-kinase (PI3K) γ deficient asthmatic mice did not develop lung eosinophilia, although the detailed mechanisms are not well known. A CC chemokine eotaxin (CCL11) plays a prominent role in developing eosinophilic inflammation through CCR3. In this study, we tested the roles of PI3Kγ in eotaxin-induced eosinophil functions using a pharmacological inhibitor. METHOD: Human peripheral blood eosinophils were isolated by CD16-negative selection method. The effect of AS605240, synthetic PI3Kγ inhibitor on eotaxin-induced adhesion, chemotaxis, and degranulation were studied using intracellular adhesion molecule-1 (ICAM-1)-coated plates, Boyden chamber system, ELISA for eosinophil-derived neurotoxin (EDN) levels in the culture supernatant, respectively. CCR3 expression levels and extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation were assessed by flowcytometry. Involvement of PI3Kγ in spontaneous apoptosis was studied using flowcytometry. RESULTS: Although AS605240 did not affect the eosinophil spontaneous apoptosis, eotaxin-induced chemotaxis, adhesion to ICAM-1 coated plate, and EDN release were inhibited by AS605240. AS605240 also inhibited the eotaxin-induced ERK1/2 phosphorylation without down-regulation of surface CCR3 expression. CONCLUSION: These results indicate that PI3Kγ inhibitor attenuates eotaxin-induced eosinophil functions by suppressing the downstream signaling of CCR3 without significant cytotoxicity. PI3Kγ plays an important role in the development of eosinophilic inflammation and blockade of PI3Kγ might be a therapeutic strategy for treatment of eosinophil-related diseases including asthma.

Splenic lymph follicles generate immunoglobulin M-producing B cells in primary biliary cirrhosis.

AIM: To reveal the site of immunoglobulin (Ig)M production in primary biliary cirrhosis (PBC) we performed immunohistochemical analysis on spleens collected from patients with PBC. METHODS: Splenic tissue samples were collected at the time of the autopsy from patients with hepatic failure. Immunostaining for IgM, CD21 and CXCL13 were performed using the splenic tissue samples. RESULTS: The samples from five out of eight cases with PBC but not in eight cases of chronic hepatitis C virus infection showed accumulation of IgM positive cells in CD21 positive lymph follicles. The CXCL13 positive cells also accumulated in the center of the lymph follicles where the IgM positive cells accumulated. CONCLUSION: The present results suggest that excess IgM is produced from the spleen of PBC. Furthermore, it was suggested that CXCL13 positive follicular dendritic cells possibly contribute to this process.

Biochemical and immunologic effects of rituximab in patients with primary biliary cirrhosis and an incomplete response to ursodeoxycholic acid.

UNLABELLED: The aim of this study was to determine the safety and potential efficacy of B-cell depletion with the anti-CD20 monoclonal antibody rituximab in patients with primary biliary cirrhosis (PBC) and an incomplete response to ursodeoxycholic acid (UDCA). This open-label study enrolled six patients with PBC and incomplete responses to UDCA to be treated with 2 doses of 1000 mg rituximab separated by 2 weeks and followed for 52 weeks. The primary endpoints were safety and changes in B-cell function. Two patients received only 1 dose of rituximab, one due to activation of latent varicella and the other due to a viral upper respiratory infection. Serum levels of total IgG, IgM, and IgA as well as anti-mitochondrial autoantibodies (AMAs) IgA and IgM decreased significantly from baseline by 16 weeks and returned to baseline levels by 36 weeks. Stimulation of B cells with CpG produced significantly less IgM at 52 weeks after treatment compared with B cells at baseline. In addition, transient decreases in memory B-cell and T-cell frequencies and an increase in CD25(high) CD4(+) T cells were observed after treatment. These changes were associated with significant increases in mRNA levels of FoxP3 and transforming growth factor-ß (TGF-ß) and a decrease in tumor necrosis factor-α (TNF-α) in CD4(+) T cells. Notably, serum alkaline phosphatase levels were significantly reduced up to 36 weeks following rituximab treatment. CONCLUSION: These data suggest that depletion of B cells influences the induction, maintenance, and activation of both B and T cells and provides a potential mechanism for treatment of patients with PBC with an incomplete response to UDCA.

Comparative analysis of portal cell infiltrates in antimitochondrial autoantibody-positive versus antimitochondrial autoantibody-negative primary biliary cirrhosis.

UNLABELLED: Substantial evidence supports dysregulated B-cell immune responses in patients with primary biliary cirrhosis (PBC), including the presence of serum antimitochondrial antibodies (AMAs). However, recent reports from murine models of PBC suggest that B cells may also provide regulatory function, and indeed the absence of B cells in such models leads to exacerbation of disease. The vast majority of patients with PBC have readily detectable AMAs, but a minority (<5%) are AMA negative (AMA(-)), even with recombinant diagnostic technology. This issue prompted us to examine the nature of B-cell infiltrates surrounding the portal areas in AMA-positive (AMA(+)) and AMA(-) patients, because they display indistinguishable clinical features. Of importance was the finding that the degree of bile duct damage around the portal areas was significantly milder in AMA(+) PBC than those observed in AMA(-) PBC patients. The portal areas from AMA(-) patients had a significant increase of cluster of differentiation (CD)5(+) cells infiltrating the ductal regions, and the levels of B-cell infiltrates were worse in the early phase of bile duct damage. The frequency of positive portal areas and the magnitude of CD5(+) and CD20(+) cellular infiltrates within areas of ductal invasion is associated with the first evidence of damage of biliary duct epithelia, but becomes reduced in the ductopenia stage, with the exception of CD5(+) cells, which remain sustained and predominate over CD20(+) cells. CONCLUSION: Our data suggest a putative role of B-cell autoimmunity in regulating the portal destruction characteristic of PBC.

Adiponectin attenuates human eosinophil adhesion and chemotaxis: implications in allergic inflammation.

OBJECTIVE: Growing evidence has shown an association between obesity and asthma. Adiponectin, an adipocyte-derived cytokine, is known to have anti-inflammatory effects with reduced concentrations in obese subjects. Recent findings raised the intriguing possibility that adiponectin might play a role in allergic inflammation, although the mechanistic basis for their relationship remains unclear. The purpose of this study was to examine whether adiponectin might affect functions of eosinophils, which play an important role in the pathogenesis of asthma. METHODS: Human peripheral blood eosinophils were purified to study expression of adiponectin receptors AdipoR1 and AdipoR2 using RT-PCR and flow cytometry. The effect of adiponectin on eosinophil survival was investigated using annexin V and propidium iodide staining. Eotaxin-induced cell adhesion was investigated using ICAM-1-coated plates. A Boyden chamber and real-time horizontal migration system were used for eotaxin-directed chemotaxis assay. Expression of eotaxin receptor CCR3 and intracellular calcium influx were assessed by flow cytometry. RESULTS: AdipoR1 and AdipoR2 were expressed in human eosinophils. Adiponectin did not affect eosinophil survival or CCR3 expression; however, eotaxin-enhanced adhesion was inhibited by pretreatment with adiponectin. Adiponectin also diminished eotaxin-directed chemotactic responses by disturbing both velocity and directionality. Calcium influx in response to eotaxin was attenuated by adiponectin. CONCLUSIONS: These results indicate that adiponectin attenuates the eosinophil functions induced by eotaxin without affecting cell viability. The inhibitory effect was associated with diminished calcium signaling rather than altering of surface receptor expression. Increasing circulating adiponectin might be a novel therapeutic modality for treatment of asthma, especially in obese asthmatics.

Gender difference in allergic airway remodelling and immunoglobulin production in mouse model of asthma.

BACKGROUND AND OBJECTIVE: 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. METHODS: Following ovalbumin (OVA)/alum intraperitoneal injection, male or female mice (BALB/c) were challenged with aerosolized 1% OVA on 3 days/week for 5 weeks, and differences in AHR, airway inflammation and airway remodelling between the sexes were investigated. RESULTS: In OVA-sensitized and OVA-challenged (OVA/OVA) female mice, eosinophils, lymphocytes, T-helper type 2 cytokines and growth factors in bronchoalveolar lavage fluid were increased compared with OVA/OVA male mice. Histological features of airway remodelling were also increased in OVA/OVA female mice. Serum total and OVA-specific immunoglobulin E (IgE) and serum IgA were significantly elevated in OVA/OVA female mice. CONCLUSIONS: These results indicate that female mice experience more airway remodelling compared with male mice. These results suggest the involvement of sex hormones and gender differences in cellular functions in airway remodelling.

Improving performance and self-efficacy of novice nurses using hybrid simulation-based mastery learning.

AIM: Acute chest pain is a commonly encountered symptom in hospital medical/surgical units; however, almost half of nurses in their second year of clinical experience in our facility have reported struggling to care for acute chest pain patients. We developed, implemented, and examined the effectiveness of a simulation-based, mastery learning clinical nursing educational program to improve self-efficacy and performance in caring for patients with acute chest pain. METHODS: The study adopted a single-site, single-cohort design using simulation-based performance assessment and self-efficacy surveys on a convenience sample of 37 second-year clinical nurse participants in multi-stage hybrid mastery learning educational intervention using asynchronous e-learning, and hands-on simulation training and assessment with feedback on caring for chest pain patients. Performance assessments and self-efficacy surveys were administered pre-, post-, and 5 months post-intervention. RESULTS: Clinical performance on the post- and 5 months follow-up assessments were significantly higher than those for the pre-test (P < .0001). The self-efficacy scores for the post- and the 5 months follow-up assessments were significantly higher than the pre-course scores (P < .0001). Participants' self-efficacy perceptions were positively correlated with their performances at 5 months post-intervention. CONCLUSION: Performance and self-efficacy of novice nurses in caring for acute chest pain patients improved significantly with the multi-stage hybrid mastery learning educational intervention, with improvements retained 5 months post-intervention. The results suggest the applicability of simulation-based mastery learning in a clinical setting for novice nurses to attain specific skills, and raise their self-perception of competence to care for patients in acute settings.

Obesity and eosinophilic inflammation: does leptin play a role.

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.

A Patient Safety Champion Program for Interprofessional Health Care Educators: Implementation and Outcomes.

INTRODUCTION: Health care educators are challenged with helping clinicians develop competencies beyond their foundational training. In health care systems where continuing professional development is not integral to practice, clinicians may have few opportunities. We describe the design, implementation, and evaluation of a professional development program in patient safety for Japanese clinical educators to acquire simulation instructional skills and become Patient Safety Champions at their organizations. METHODS: Mixed methods were used in a longitudinal pre/post study design. The Kirkpatrick evaluation model was used to evaluate outcomes of a workshop, overall program, on-site training experiences, and impact as Patient Safety Champions. Self-assessment data on skills and knowledge of patient safety, simulation instructional methods, interprofessional collaboration, and leadership were collected and analyzed. RESULTS: Eighty-nine percent of participants facilitated on-site patient safety training within 6 months of workshop completion. Skills and knowledge improvement were observed immediately postworkshop in four categories: patient safety, simulation instructional methods, interprofessional collaboration and communication, and leadership as a patient safety champion. Skills and knowledge increased at 6 months after facilitation of on-site safety training. Program mean satisfaction scores ranged from 84% to 92%. Mean Patient Safety Champion in-facility evaluations were 4.2 to 4.7 on a 5-point scale. DISCUSSION: High levels of knowledge, skill retention, and behavior change are attributed to goal setting, outcome-oriented pedagogy, and reflective sessions. The Patient Safety Champion model and experiential learning approach gave Japanese clinical educators in medicine, nursing, and pharmacy an opportunity to learn from each other in simulations reflecting the practice environment.

B cells promote hepatic inflammation, biliary cyst formation, and salivary gland inflammation in the NOD.c3c4 model of autoimmune cholangitis.

There are now several murine models of autoimmune cholangitis that have features both similar and distinct from human PBC. One such model, the NOD.c3c4 mouse, manifests portal cell infiltrates, anti-mitochondrial antibodies but also biliary cysts. The biliary cysts are not a component of PBC and not found in the other murine models. To address the immunopathology in these mice, we generated genetically B cell deficient Igµ(-/-) NOD.c3c4 mice and compared the immunopathology of these animals to control B cell sufficient NOD.c3c4 mice. B cell deficient mice demonstrated decreased number of non-B cells in the liver accompanied by reduced numbers of activated natural killer cells. The degree of granuloma formation and bile duct damage were comparable to NOD.c3c4 mice. In contrast, liver inflammation, biliary cyst formation and salivary gland inflammation was significantly attenuated in these B cell deficient mice. In conclusion, B cells play a critical role in promoting liver inflammation and also contribute to cyst formation as well as salivary gland pathology in autoimmune NOD.c3c4 mice, illustrating a critical role of B cells in modulating specific organ pathology and, in particular, in exacerbating both the biliary disease and the sialadenitis.

[Development of a microbiology data warehouse (Akita-ReNICS) for networking hospitals in a medical region].

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 system's 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 computer's 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.