Disease burden of bacteraemia with extended-spectrum beta-lactamase-producing and carbapenem-resistant Enterobacterales in Korea

BACKGROUND

Despite the significant impact of multi-drug-resistant bacteraemia, especially extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) and carbapenem-resistant Enterobacterales (CRE), the burden of disease has not been investigated thoroughly.

AIM

To evaluate the clinical outcomes and socio-economic burden of ESBL-E and CRE bacteraemia nationwide in the Republic of Korea.

METHODS

A search was undertaken for all cases of ESBL-E and CRE bacteraemia and matched controls in 10 hospitals in the Republic of Korea over 6 months. Patients with ESBL-E or CRE bacteraemia were classified as the R group, and matched controls with antibiotic-susceptible bacteraemia and without infection were classified as the S and N groups, respectively. Patients' clinical data were collected, and the economic burden was estimated based on medical expenses, loss of productivity and total costs.

FINDINGS

In total, 795 patients were identified, including 265 patients with ESBL-E or CRE bacteraemia and their matched controls. The mean total length of stay for patients with ESBL-E and CRE in the R group was 1.53 and 1.90 times that of patients in the S group, respectively. The 90-day mortality rates for ESBL-E in the R and S groups were 12.1% and 5.6%, respectively, and the corresponding figures for CRE were 28.6% and 12.0%. There were significant differences in the total costs between the R, S and N groups for both ESBL-E and CRE (ESBL-E: $11,151 vs $8712 vs $6063, P=0.004; CRE: $40,464 vs $8748 vs $7279, P=0.024).

CONCLUSION

The clinical and economic burden imposed by ESBL-E or CRE bacteraemia was extremely high. These findings suggest that efforts to control resistant bacteraemia are necessary to reduce this burden.

Appropriateness of antibiotic use for patients with asymptomatic bacteriuria or urinary tract infection with positive urine culture: a retrospective observational multi-centre study in Korea

BACKGROUND

Antibiotic resistance threatens public health worldwide, and inappropriate use of antibiotics is one of the main causes.

AIM

To evaluate qualitative use of antibiotics in asymptomatic bacteriuria (ABU) and urinary tract infection (UTI).

METHODS

Cases of positive urine culture (≥105 colony-forning units/mL) performed in inpatient, outpatient and emergency departments in April 2021 were screened in 26 hospitals in the Republic of Korea. The cases were classified as ABU, lower UTI and upper UTI. The appropriateness of antibiotic use was evaluated retrospectively by infectious disease specialists using quality indicators based on clinical guidelines for ABU and UTI.

RESULTS

This study included a total of 2697 patients with ABU or UTI. The appropriateness of antibiotic use was assessed in 1157 patients with ABU, and in 677 and 863 patients with lower and upper UTI, respectively. Among the 1157 patients with ABU, 251 (22%) were prescribed antibiotics without appropriate indications. In 66 patients with ABU in which antibiotics were prescribed with appropriate indications, the duration was adequate in only 23 (34.8%) patients. The appropriateness of empirical and definite antibiotics was noted in 527 (77.8%) and 353 (68.0%) patients with lower UTI, and 745 (86.3%) and 583 (78.2%) patients with upper UTI, respectively. The duration of antibiotics was adequate in 321 (61.8%) patients with lower UTI and 576 (78.7%) patients with upper UTI.

CONCLUSIONS

This nationwide qualitative assessment of antibiotic use in ABU and UTI revealed that antibiotics were often prescribed inappropriately, and the duration of antibiotics was unnecessarily prolonged.

Applicability and limitations of quality indicator-based assessment of appropriateness in antimicrobial use: a comparison with expert opinion

BACKGROUND

The effective implementation of antimicrobial stewardship requires an a-priori assessment of the appropriateness of antimicrobial prescriptions.

AIM

To evaluate the effectiveness of quality indicators (QIs) in determining the appropriateness of antimicrobial prescriptions compared to that of expert opinions.

METHODS

The study assessed antimicrobial use in 20 hospitals in Korea, with infectious disease specialists rating the appropriateness based on QIs and expert opinions. The selected QIs were (1) taking two blood cultures, (2) taking cultures from suspected sites of infection, (3) prescribing empirical antimicrobials according to guidelines, and (4) changing from empirical to pathogen-directed therapy for hospitalized patients and (2, 3, and 4) for ambulatory patients. Applicability, compliance with QIs, and agreement between QIs and expert opinions were investigated.

FINDINGS

Overall, 7999 therapeutic uses of antimicrobials were investigated at the study hospitals. The experts rated 20.5% (1636/7999) as inappropriate use. For hospitalized patients, antimicrobial use was assessed based on all four QIs in 28.8% (1798/6234) of the cases. For ambulatory care patients, only 7.5% (102/1351) of the antimicrobial use cases were assessed using all three QIs. The agreement between expert opinions and all four QIs for hospitalized patients was minimal (κ = 0.332), whereas that between expert opinions and all three QIs for ambulatory patients was weak (κ = 0.598).

CONCLUSION

QIs have limitations in determining the appropriateness of antimicrobial use, and the degree of agreement with expert opinions was low. Therefore, these QI limitations should be considered when determining the appropriateness of antimicrobial use.

Real-world eligibility and cost-effectiveness analysis for empagliflozin in patients with heart failure

Background/Introduction

Empagliflozin was approved by the US Food and Drug Administration (FDA) and European Medicines Agency (EMA) for reducing cardiovascular mortality and heart failure (HF) hospitalization in both patients with HF with reduced ejection fraction (HFrEF) and HF with preserved ejection fraction (HFpEF).

Purpose

Limited data are available on the generalizability of empagliflozin to clinical practice. Therefore, we evaluated real-world eligibility and cost-effectiveness based on a nationwide prospective HF registry.

Methods

For the study, 3108 HFrEF and 2070 HFpEF patients from the Korean Acute Heart Failure (KorAHF) registry were analysed. Eligibility was estimated by FDA and EMA label criteria and by inclusion and exclusion criteria of EMPEROR-Reduced and EMPEROR-Preserved trials. The cost-effectiveness analysis was performed using the decision tree model, where effectiveness was the avoidance of the first hospitalization.

Results

Among the KorAHF patients, 91.4% met FDA & EMA label criteria, while 44.7% met the clinical trial criteria. The main factor for exclusion in the clinical trial-based empagliflozin eligibility was low systolic blood pressure, including 18.7% of HFrEF and 11.0% of HFpEF patients. Other factors were acute (<4 weeks) myocardial infarction and impaired renal function (eGFR <20 mL/min/1.73 m2 or requiring dialysis). The overall expected hospitalization rate and cost reduction were 3.6 and US$ 14,885 per 100 eligible HF patients per year. In HFrEF patients, hospitalization rate and cost reduction were 4.8 and US$ 28,442. However, in HFpEF, the cost was increased by US$ 7,576, while hospitalization reduction was 1.7.

Conclusion(s)

There is a large discrepancy of real-world eligibility for empagliflozin between FDA & EMA labels and clinical trial criteria. The cost-effectiveness benefit was more evident in patients with HFrEF than HFpEF. The efficacy and safety of empagliflozin in real-world patients should be further investigated for a broader range of clinical applications.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Minister of Science and Information and Communication Technologies (NRF-2021R1F1A1063430), by the Catholic Medical Center Research Foundation (2022), and by the Research of Korea Centers for Disease Control and Prevention (2010-E63003-00, 2011-E63002-00, 2012-E63005-00, 2013-E6300300, 2014-E63003-01, 2015-E63003-02, 2016-ER6303-00, and 2017-ER6303-01).

Characterization of myocardial proteomics in biopsy proven cardiomyopathies

Background

Difference in proteomic expression according to the etiology of cardiomyopathies is not well known.

Purpose

We aimed to identify proteome based pathogenesis in patients with biopsy proven cardiomyopathies.

Methods

Comparative proteomic analysis of biopsy specimens were performed from 9 patients with cardiomyopathy (3 dilated cardiomyopathy (DCM), 2 hypertrophic cardiomyopathy (HCM) and 4 myocarditis) as well as 5 controls (normal endomyocardial biopsy specimen from one-year surveillance of heart transplant recipients) by tandem mass tag combined with liquid chromatography-mass spectrometry. Differential expression protein analysis, gene ontology analysis and Ingenuity pathway analysis were done to discover molecular mechanism for the differentially expressed proteins in each cardiomyopathy compared to the control.

Results

Differential expression protein analysis showed higher proportion of significantly increased proteins (Log2 fold change ≥1) in HCM and myocarditis, whereas higher proportion of significantly decreased proteins (Log2 fold change ≤−1) in DCM compared to controls (Figure). According to the gene ontology analysis, upregulation of neutrophil degranulation, and down-regulation of mitochondrial translation protein was noted in patients with DCM. In patients with HCM, platelet degranulation protein was increased, and mitochondrial ATP synthesis coupled electron transport, was decreased. In patients with myocarditis, neutrophil related proteins and calcium ion binding protein was increased, but muscle cell development, protein was decreased. Ingenuity pathway analysis revealed downregulation of oxidative phosphorylation and upregulation of sirtuin signalling pathway both in DCM and HCM. In myocarditis, various pathways related to inflammation were upregulated with only RHO GDP dissociation inhibitors downregulated.

Conclusions

This study showed that each cardiomyopathy exhibited different proteomic expression compared to normal heart. Further large detailed study is needed to understand the association between proteomic expression and disease pathophysiology.

Funding Acknowledgement

Type of funding sources: None.

Analysis of influence of background therapy for comorbidities in the period before infection on the risk of the lethal COVID outcome. Data from the international ACTIV SARS-CoV-2 registry («Analysis of chronic non-infectious diseases dynamics after COVID-19 infection in adult patients SARS-CoV-2»)

Aim      To study the effect of regular drug therapy for cardiovascular and other diseases preceding the COVID-19 infection on severity and outcome of COVID-19 based on data of the ACTIVE (Analysis of dynamics of Comorbidities in paTIents who surVived SARS-CoV-2 infEction) registry.Material and methods  The ACTIVE registry was created at the initiative of the Eurasian Association of Therapists. The registry includes 5 808 male and female patients diagnosed with COVID-19 treated in a hospital or at home with a due protection of patients' privacy (data of nasal and throat smears; antibody titer; typical CT imaging features). The register territory included 7 countries: the Russian Federation, the Republic of Armenia, the Republic of Belarus, the Republic of Kazakhstan, the Kyrgyz Republic, the Republic of Moldova, and the Republic of Uzbekistan. The registry design: a closed, multicenter registry with two nonoverlapping arms (outpatient arm and in-patient arm). The registry scheduled 6 visits, 3 in-person visits during the acute period and 3 virtual visits (telephone calls) at 3, 6, and 12 mos. Patient enrollment started on June 29, 2020 and was completed on October 29, 2020. The registry completion is scheduled for October 29, 2022. The registry ID: ClinicalTrials.gov: NCT04492384. In this fragment of the study of registry data, the work group analyzed the effect of therapy for comorbidities at baseline on severity and outcomes of the novel coronavirus infection. The study population included only the patients who took their medicines on a regular basis while the comparison population consisted of noncompliant patients (irregular drug intake or not taking drugs at all despite indications for the treatment).Results The analysis of the ACTIVE registry database included 5808 patients. The vast majority of patients with COVID-19 had comorbidities with prevalence of cardiovascular diseases. Medicines used for the treatment of COVID-19 comorbidities influenced the course of the infectious disease in different ways. A lower risk of fatal outcome was associated with the statin treatment in patients with ischemic heart disease (IHD); with angiotensin-converting enzyme inhibitors (ACEI)/angiotensin receptor antagonists and with beta-blockers in patients with IHD, arterial hypertension, chronic heart failure (CHF), and atrial fibrillation; with oral anticoagulants (OAC), primarily direct OAC, clopidogrel/prasugrel/ticagrelor in patients with IHD; with oral antihyperglycemic therapy in patients with type 2 diabetes mellitus (DM); and with long-acting insulins in patients with type 1 DM. A higher risk of fatal outcome was associated with the spironolactone treatment in patients with CHF and with inhaled corticosteroids (iCS) in patients with chronic obstructive pulmonary disease (COPD).Conclusion      In the epoch of COVID-19 pandemic, a lower risk of severe course of the coronavirus infection was observed for patients with chronic noninfectious comorbidities highly compliant with the base treatment of the comorbidity.

High-throughput organ-on-chip platform with integrated programmable fluid flow and real-time sensing for complex tissue models in drug development workflows

Drug development suffers from a lack of predictive and human-relevant in vitro models. Organ-on-chip (OOC) technology provides advanced culture capabilities to generate physiologically appropriate, human-based tissue in vitro, therefore providing a route to a predictive in vitro model. However, OOC technologies are often created at the expense of throughput, industry-standard form factors, and compatibility with state-of-the-art data collection tools. Here we present an OOC platform with advanced culture capabilities supporting a variety of human tissue models including liver, vascular, gastrointestinal, and kidney. The platform has 96 devices per industry standard plate and compatibility with contemporary high-throughput data collection tools. Specifically, we demonstrate programmable flow control over two physiologically relevant flow regimes: perfusion flow that enhances hepatic tissue function and high-shear stress flow that aligns endothelial monolayers. In addition, we integrate electrical sensors, demonstrating quantification of barrier function of primary gut colon tissue in real-time. We utilize optical access to the tissues to directly quantify renal active transport and oxygen consumption via integrated oxygen sensors. Finally, we leverage the compatibility and throughput of the platform to screen all 96 devices using high content screening (HCS) and evaluate gene expression using RNA sequencing (RNA-seq). By combining these capabilities in one platform, physiologically-relevant tissues can be generated and measured, accelerating optimization of an in vitro model, and ultimately increasing predictive accuracy of in vitro drug screening.

Risk factors for the delayed diagnosis of extrapulmonary TB

BACKGROUND: Extrapulmonary TB (EPTB) is more difficult to diagnose than pulmonary TB. The delayed management of EPTB can lead to complications and increase the socio-economic burden.METHODS: Patients newly diagnosed with EPTB were retrospectively enrolled from 11 general hospitals in South Korea from January 2017 to December 2018. The basic characteristics of patients were described. Univariable and multivariable analyses were performed between early and delayed diagnosis groups to identify risk factors for delayed diagnosis and treatment in EPTB.RESULTS: In total, 594 patients were enrolled. Lymph node TB (28.3%) was the predominant form, followed by abdominal (18.4%) and disseminated TB (14.5%). Concurrent lung involvement was 17.8%. The positivity of diagnostic tests showed no significant difference between the two groups. Acute clinical manifestations in disseminated, pericardial and meningeal TB, and immunosuppression were associated with early diagnosis. Delayed diagnosis was associated with outpatient clinic visits, delayed sample acquisition and diagnostic departments other than infection or pulmonology.CONCLUSION: The delay in diagnosis and treatment of EPTB was not related to differences in microbiological characteristics of Mycobacterium tuberculosis itself; rather, it was due to the indolent clinical manifestations that cause referral to non-TB-specialised departments in the outpatient clinic and delay the suspicion of TB and diagnostic testing.

Energy transfer from adipocytes to cancer cells in breast cancer

Limitations of the current therapeutic approach have raised the need for a novel therapeutic agent in breast cancer. Recently, interest in drugs targeting the tumor microenvironment (TME) had drawn attention in the treatment of breast cancer. Furthermore, recent studies have suggested the role of adipocytes, which are part of the TME, in tumor initiation, growth, and metastasis. In this study, we investigated the metabolic interaction between adipocytes and breast cancer cells and its potential as a new therapeutic target in breast cancer. Breast cancer cell lines and human breast cancer tissue samples were evaluated. Compared to cancer cells cultured alone, or the control group, those co-cultured with adipocytes showed lipid transfer from adipocytes to cancer cells and it was different according to the molecular subtype of breast cancer. Breast cancer cells affected the lipolysis of adipocytes and adipocytes affected the β-oxidation of breast cancer cells. The key molecule of the process was fatty acid binding protein 4 (FABP4), which is combined with free fatty acid (FFA) and supports its migration to cancer cells. When FABP4 was suppressed, lipid transfer between adipocytes and cancer cells, lipolysis of adipocytes, and β-oxidation of breast cancer cells were reduced. Furthermore, the expression of lipid metabolism-related proteins and lipolysis-related proteins in breast cancer with adipose stroma showed significantly different expression according to the region of breast cancer tissue. Taken together, we demonstrated the metabolic interaction between adipocytes and breast cancer cells. Breast cancer cells increase the lipolysis in adipocytes and produce a fatty acid, and fatty acid enters into cancer cells. Also, adipocytes contribute to the survival and growth of cancer cells through increased mitochondrial β-oxidation by using fatty acid from adipocytes. The key molecule of the process is FABP4 and when FABP4 is suppressed, the metabolic interaction is reduced, suggesting its role as a potential therapeutic target.

Electron Capture Gas-Liquid Chromatographic Determination of Methyl Mercury in Fish and Shellfish: Collaborative Study

A method for determining methyl mercury in fish and shellfish was collaboratively studied in 8 laboratories. Methyl mercury is isolated from acetonewashed, homogenized tissue by adding hydrochloric acid and extracting into benzene the methyl mercuric chloride that is formed. The benzene extract is concentrated and analyzed for methyl mercuric chloride by electron capture gas-liquid chromatography on 5% DEGS-PS treated with inorganic mercuric chloride solution. The quantitation limit for the method is 0.05 μg Hg/g. Each collaborator determined methyl mercury at 2 levels in blind duplicate samples of swordfish, tuna, oyster, and shrimp tissues. Both fortified and unfortified samples were analyzed. Methyl-bound mercury in the samples ranged from 0.15 to 148 μg Hg/g. The reproducibility coefficients of variation for the 8 samples ranged from 3 to 13%. The accuracy, measured by comparison to reference values, ranged from 99 to 120%. Reference values were determined in the Associate Referee's laboratory by replicate analyses of the fortified and unfortified samples. The method has been adopted official first action.

Predictive biomarkers for response to EGFR-directed monoclonal antibodies for advanced squamous cell lung cancer

Background

Upregulated expression and aberrant activation of the epidermal growth-factor receptor (EGFR) are found in lung cancer, making EGFR a relevant target for non-small-cell lung cancer (NSCLC). Treatment with anti-EGFR monoclonal antibodies (mAbs) is associated with modest improvement in overall survival in patients with squamous cell lung cancer (SqCLC) who have a significant unmet need for effective treatment options. While there is evidence that using EGFR gene copy number, EGFR mutation, and EGFR protein expression as biomarkers can help select patients who respond to treatment, it is important to consider biomarkers for response in patients treated with combination therapies that include EGFR mAbs.

Design

Randomized trials of EGFR-directed mAbs cetuximab and necitumumab in combination with chemotherapy, immunotherapy, or antiangiogenic therapy in patients with advanced NSCLC, including SqCLC, were searched in the literature. Results of associations of potential biomarkers and outcomes were summarized.

Results

Data from phase III clinical trials indicate that patients with NSCLC, including SqCLC, whose tumors express high levels of EGFR protein (H-score of ≥200) and/or gene copy numbers of EGFR (e.g. ≥40% cells with ≥4 EGFR copies as detected by fluorescence in situ hybridization; gene amplification in ≥10% of analyzed cells) derive greater therapeutic benefits from EGFR-directed mAbs. Biomarker data are limited for EGFR mAbs used in combination with immunotherapy and are absent when used in combination with antiangiogenic agents.

Conclusions

Therapy with EGFR-directed mAbs in combination with chemotherapy is associated with greater clinical benefits in patients with NSCLC, including SqCLC, whose tumors express high levels of EGFR protein and/or have increased EGFR gene copy number. These data support validating the role of these as biomarkers to identify those patients who derive the greatest clinical benefit from EGFR mAb therapy. However, data on biomarkers for EGFR-directed mAbs combined with immunotherapy or antiangiogenic agents remain limited.

Traumatic combined vertical atlanto-occipital and atlanto-axial dislocations with 2-part fracture of the atlas: Two case reports

RATIONALE

To our knowledge, this is the first report of traumatic combined vertical atlanto-occipital dislocation (AOD) and atlanto-axial dislocation (AAD) with 2-part fracture of the atlas.

PATIENT CONCERNS

The first case was of a 31-year-old woman admitted to the emergency room comatose after a traffic accident. The second case was of a 21-year-old woman admitted to the emergency room comatose after a fall.

DIAGNOSES

Traumatic combined vertical AOD and AAD with 2-part fractures of the atlas was diagnosed using plain radiography, 2-dimensional computed tomography, and/or magnetic resonance imaging of the cervical spine.

INTERVENTION

The first patient received immediate intubation and cardiopulmonary resuscitation in the emergency room. The second patient also received immediate intubation in the emergency room. After her vitals stabilized, she underwent occipitocervical fusion with instrumentation.

OUTCOMES

The first patient died 2 days after the accident. The second patient remained quadriplegic in a ventilatory-dependent state at 1 year after surgery. She continues to receive comprehensive rehabilitation.

LESSONS

Immediate respiratory support and surgical stabilization are important for saving lives in this kind of extremely unstable and fatal complex upper cervical spine injury.

Atypicalities of Gesture Form and Function in Autistic Adults

While well-represented on clinical measures, co-speech gesture production has never been formally studied in autistic adults. Twenty-one verbally fluent autistic adults and 21 typically developing controls engaged in a controlled conversational task. Group differences were observed in both semantic/pragmatic and motoric features of spontaneously produced co-speech gestures. Autistic adults prioritized different functions of co-speech gesture. Specifically, they used gesture more than controls to facilitate conversational turn-taking, demonstrating a novel nonverbal strategy for regulating conversational dynamics. Autistic adults were more likely to gesture unilaterally than bilaterally, a motoric feature of gesture that was individually associated with autism symptoms. Co-speech gestures may provide a link between nonverbal communication symptoms and known differences in motor performance in autism.

Abstract OT2-04-02: A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress

Background

In patients with early stage breast cancer, regional nodal irradiation (RNI) is added to whole breast irradiation (WBI) in order to control microscopic regional disease and to prevent systemic spread of cancer. According to recent randomized trials (MA.20 and EORTC 22922-10925), prophylactic RNI was associated with improvement in disease-free survival (DFS) in the patients with high-risk node negative or pN1 breast cancer. However, systemic agents now known to improve loco-regional control, such as taxane or endocrine therapy, were prescribed to a small percentage of patients in the studies. The benefit of RNI found in the previous studies might be attributed to incorporation of less effective systemic treatments. The impact of prophylactic RNI in pN1 breast cancer should be evaluated in the patients receiving modern systemic treatment. The current study was conducted to compare the effect of post-lumpectomy WBI vs WBI plus RNI on DFS in pN1 breast cancer patients who received adjuvant taxane-based chemotherapy.

Methods

This study is a multicenter, phase 3, randomized controlled non-inferiority trial (NCT03269981). Eligibility criteria are ≥ 20 years female; pathologically proven invasive carcinoma of the breast; one to three positive axillary lymph nodes (pN1) in pathologic specimen; receiving breast-conserving surgery followed by taxane-based chemotherapy; having adjuvant endocrine therapy or anti-HER2 treatment according to molecular subtype of tumor. Patients are randomly assigned in a 1:1 ratio to receive WBI or WBI plus RNI. Patient randomization was stratified by molecular subtype of tumor (i.e. luminal A/luminal B/luminal HER2/HER2-enriched/triple-negative) and methods of axillary management (i.e. sentinel lymph node biopsy/axillary lymph node dissection). The primary outcome is DFS. The secondary outcomes include DFS according to molecular subtype, treatment-related toxicity, and patient's quality of life per EORTC QLQ-C30 and QLQ-BR23. Patients will be followed for survival and disease recurrence for seven years. A total of 1,926 patients are planned to be enrolled, with recruitment initiated in April 2017. As of June 2018, a total of 236 patients were enrolled.

Acknowledgement

This study was supported by a grant from the National R&D Program for Cancer Control, Ministry of Health & Welfare, Republic of Korea (grant number: HA17C0043010018).

Citation Format: Kim H, Park W, Choi DH, Ahn SJ, Kim SS, Kim ES, Lee JH, Lee KC, Kim JH, Lee H-S, Kim JH, Kim MY, Park HJ, Kim K, Song SH, Kwon J, Lee IJ, Kim TH, Kim TG, Chang AR, Cho O, Jeong BK, Ha B, Lee J, Ki Y. A phase 3 study of post-lumpectomy radiotherapy to whole breast + regional lymph nodes vs whole breast alone for patients with pN1 breast cancer treated with taxane-based chemotherapy (KROG 1701): Trial in progress [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-04-02.

Impact of antimicrobial treatment duration on outcome of Staphylococcus aureus bacteraemia: a cohort study

OBJECTIVES

To assess the outcome of Staphylococcus aureus bacteraemia (SAB) according to factors associated with necessity for longer treatment in conjunction with the duration of treatment.

METHODS

We prospectively collected the data of patients with SAB consecutively during 12 to 39 months from 11 hospitals. If multiple episodes of SAB occurred in one patient, only the first episode was enrolled. Factors associated with necessity for longer treatment were defined as follows: persistent bacteraemia, metastatic infection, prosthesis and endocarditis. If any of the factors were present, then the case was defined as longer antibiotic treatment warranted (LW) group; those without any factors were defined as shorter antibiotic treatment sufficient (SS) group. Poor outcome was defined as a composite of 90-day mortality or 30-day recurrence. Duration of antibiotic administration was classified as <14 or ≥14 days in the SS group and <28 or ≥28 days in the LW group.

RESULTS

Among 2098 cases, the outcome was analysed in 1866 cases, of which 591 showed poor outcome. The SS group accounted for 964 cases and the LW group for 852. On multivariate analysis, age over 65 years, pneumonia, higher Sequential Organ Failure Assessment (SOFA) score and chronic liver diseases were risk factors for poor outcome. Administration of antibiotics less than the recommendation was associated with poor outcome, but this significance was observed only in the LW group (adjusted odds ratio = 1.68; 95% confidence interval, 1.00-2.83; p 0.05).

CONCLUSIONS

Inappropriately short antibiotic treatment was associated with poor outcome in the LW group. Vigilant evaluation for risk factors to determine the duration of treatment may improve the outcome among patients with SAB.

Active surveillance for carbapenem-resistant Enterobacteriaceae, vancomycin-resistant enterococci and toxigenic Clostridium difficile among patients transferred from long-term care facilities in Korea

A 10-month active surveillance study was conducted to assess carriage of carbapenemase-producing Enterobacteriaceae (CPE), vancomycin-resistant enterococci (VRE) and toxigenic Clostridium difficile colonization among patients transferred to hospital from long-term care facilities (LTCFs). Four (1.4%) patients with carbapenem-resistant Enterobacteriaceae (none of which were CPE), 59 (21%) patients with VRE and 20 (7.1%) patients colonized with toxigenic C. difficile were identified from 282 rectal specimens. There was no outbreak of VRE infection during the study period. The low prevalence of CPE carriage suggests that screening all admissions from LTCFs for CPE would not be cost-effective, and that screening and use of contact precautions for VRE should be reconsidered.

Concordance of results of blood and tissue cultures from patients with pyogenic spondylitis: a retrospective cohort study

OBJECTIVES

To investigate the concordance of results of blood and tissue cultures in patients with pyogenic spondylitis.

METHODS

We searched for patients with pyogenic spondylitis in whom microorganisms were isolated from both blood and tissue cultures by retrospective review of medical records in three tertiary university-affiliated hospitals between January 2005 and December 2015. The species and antimicrobial susceptibility patterns of isolates from blood and tissue cultures were compared.

RESULTS

Among 141 patients with pyogenic spondylitis in whom microorganisms were isolated from both blood and tissue cultures, the species of blood and tissue isolates were identical in 135 patients (95.7%, 135/141). Excluding the four anaerobic isolates, we investigated antimicrobial susceptibility patterns of 131 isolates of the same species from blood and tissue cultures. Antibiotic susceptibility patterns were identical in 128 patients (97.7%, 128/131). The most common isolates were Staphylococcus aureus (86 patients; 85 concordant and one discordant), followed by streptococcus (24 patients; 22 concordant and two discordant), and Escherichia coli (eight patients; all concordant).

CONCLUSIONS

We suggest that a positive blood culture from patients with pyogenic spondylitis could preclude the need for additional tissue cultures, especially when S. aureus and streptococcus grew in blood cultures.

agr functionality affects clinical outcomes in patients with persistent methicillin-resistant Staphylococcus aureus bacteraemia

Methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) often persists despite appropriate antibiotic therapy. It is unclear what microbiological factors contribute to poor clinical outcomes in persistent MRSAB (pMRSAB). We aimed to identify clinical and microbiological risk factors for in-hospital mortality in pMRSAB. We analysed MRSAB cases prospectively collected between 2009 and 2016 at 11 hospitals in Korea, defining cases of pMRSAB as MRSAB lasting ≥5 days despite administration of effective antibiotics. The first blood isolates from the pMRSAB cases were tested for staphylococcal cassette chromosome mec type, staphylococcal protein A type, accessary gene regulator (agr) type, genes for Panton-Valentine leukocidin and phenol-soluble modulin-mec, vancomycin minimum inhibitory concentration, vancomycin heteroresistance, and agr functionality. We also collected clinical information for each case. Of 960 MRSAB cases, 152 pMRSAB were finally eligible. Univariable analysis revealed that in-hospital mortality was significantly associated with Charlson's comorbidity-weighted index (CCWI) score, Pitt bacteremia score, sequential organ failure assessment score, presentation with septic shock, pneumonia, agr dysfunction, and vancomycin heteroresistance. Bone and joint infections were negatively associated with in-hospital mortality. Multivariable analysis revealed the following independent risk factors for in-hospital mortality: CCWI score [adjusted odds ratio (aOR), per one point, 1.25; 95% confidence interval (CI), 1.08-1.44; P = 0.003), Pitt bacteremia score (aOR, per one point, 1.33; 95% CI, 1.09-1.62; P = 0.005), non-eradicated foci of infection (aOR, 3.12; 95% CI, 1.18-8.27; P = 0.022), and agr dysfunction (aOR, 2.48; 95% CI, 1.12-5.47; P = 0.025). agr dysfunction is an independent risk factor for in-hospital mortality in pMRSAB.

Phenotypic changes of methicillin-resistant Staphylococcus aureus during vancomycin therapy for persistent bacteraemia and related clinical outcome

Persistent bacteraemia (PB) due to methicillin-resistant Staphylococcus aureus (MRSA) that fails to respond to glycopeptide therapy is a well-documented clinical problem. There are limited data on changes in agr functionality, vancomycin susceptibility and heteroresistance during MRSA PB. Thus, the frequency of these changes and their clinical significance remain unclear. Only patients with MRSA PB (≥7 days) from a prospective cohort of S. aureus bacteraemia were included. We collected isogenic paired strains and compared vancomycin MIC, vancomycin heteroresistance, and agr functionality between initial and final blood isolates. We also assessed the clinical outcome. A total of 49 patients had MRSA PB over 22 months. Bacteraemia persisted for a median of 13 days and most patients (98%) received glycopeptide as initial therapy. Among 49 isogenic pairs, only one pair showed a vancomycin MIC increase ≥2-fold by broth microdilution method, and only seven (14%) by E-test. Significant portions of initial isolates had vancomycin heteroresistance (49%) and agr dysfunction (76%). Development of vancomycin heteroresistance during PB occurred in four (16%) among 25 initial vancomycin-susceptible isolates, and acquisition of agr dysfunction occurred in two (16%) among 12 initial agr-functional isolates. Changes in the opposite direction occasionally occurred. These phenotypic changes during PB were not associated with mortality, whereas agr dysfunction of the initial isolates was significantly associated with mortality. During MRSA PB, phenotypic changes of MRSA isolates occurred occasionally under prolonged vancomycin exposure but were not significantly associated with clinical outcome. In contrast, initial agr dysfunction could be a predictor for mortality in MRSA PB.

Characterization of micro-resonator based on enhanced metal insulator semiconductor capacitor for glucose recognition

We present a concept for the characterization of micro-fabricated based resonator incorporating air-bridge metal-insulator-semiconductor (MIS) capacitor to continuously monitor an individual's state of glucose levels based on frequency variation. The investigation revealed that, the micro-resonator based on MIS capacitor holds considerable promise for implementation and recognition as a glucose sensor for human serum. The discrepancy in complex permittivity as a result of enhanced capacitor was achieved for the detection and determination of random glucose concentration levels using a unique variation of capacitor that indeed results in an adequate variation of the resonance frequency. Moreover, the design and development of micro-resonator with enhanced MIS capacitor generate a resolution of 112.38 × 10^-3pF/mg/dl, minimum detectable glucose level of 7.45mg/dl, and a limit of quantification of 22.58mg/dl. Additionally, this unique approach offers long-term reliability for mediator-free glucose sensing with a relative standard deviation of less than 0.5%.

A portable and reconfigurable multi-organ platform for drug development with onboard microfluidic flow control

The drug development pipeline is severely limited by a lack of reliable tools for prediction of human clinical safety and efficacy profiles for compounds at the pre-clinical stage. Here we present the design and implementation of a platform technology comprising multiple human cell-based tissue models in a portable and reconfigurable format that supports individual organ function and crosstalk for periods of up to several weeks. Organ perfusion and crosstalk are enabled by a precision flow control technology based on electromagnetic actuators embedded in an arrayed format on a microfluidic platform. We demonstrate two parallel circuits of connected airway and liver modules on a platform containing 62 electromagnetic microactuators, with precise and controlled flow rates as well as functional biological metrics over a two week time course. Technical advancements enabled by this platform include the use of non-sorptive construction materials, enhanced scalability, portability, flow control, and usability relative to conventional flow control modes (such as capillary action, pressure heads, or pneumatic air lines), and a reconfigurable and modular organ model format with common fluidic port architecture. We demonstrate stable biological function for multiple pairs of airway-liver models for periods of 2 weeks in the platform, with precise control over fluid levels, temperature, flow rate and oxygenation in order to support relevant use cases involving drug toxicity, efficacy testing, and organ-organ interaction.

Surveillance of the Middle East respiratory syndrome (MERS) coronavirus (CoV) infection in healthcare workers after contact with confirmed MERS patients: incidence and risk factors of MERS-CoV seropositivity

Given the mode of transmission of Middle East respiratory syndrome (MERS), healthcare workers (HCWs) in contact with MERS patients are expected to be at risk of MERS infections. We evaluated the prevalence of MERS coronavirus (CoV) immunoglobulin (Ig) G in HCWs exposed to MERS patients and calculated the incidence of MERS-affected cases in HCWs. We enrolled HCWs from hospitals where confirmed MERS patients had visited. Serum was collected 4 to 6 weeks after the last contact with a confirmed MERS patient. We performed an enzyme-linked immunosorbent assay (ELISA) to screen for the presence of MERS-CoV IgG and an indirect immunofluorescence test (IIFT) to confirm MERS-CoV IgG. We used a questionnaire to collect information regarding the exposure. We calculated the incidence of MERS-affected cases by dividing the sum of PCR-confirmed and serology-confirmed cases by the number of exposed HCWs in participating hospitals. In total, 1169 HCWs in 31 hospitals had contact with 114 MERS patients, and among the HCWs, 15 were PCR-confirmed MERS cases in study hospitals. Serologic analysis was performed for 737 participants. ELISA was positive in five participants and borderline for seven. IIFT was positive for two (0.3%) of these 12 participants. Among the participants who did not use appropriate personal protective equipment (PPE), seropositivity was 0.7% (2/294) compared to 0% (0/443) in cases with appropriate PPE use. The incidence of MERS infection in HCWs was 1.5% (17/1169). The seroprevalence of MERS-CoV IgG among HCWs was higher among participants who did not use appropriate PPE.

Evaluation of Circulating Markers of Neutrophil Extracellular Trap (NET) Formation as Risk Factors for Diabetic Retinopathy in a Case-Control Association Study

Background: Inflammatory stimuli can induce neutrophils to release nuclear DNA combined with histones into the extracellular space, forming neutrophil extracellular traps. Because inflammation contributes to diabetic retinopathy, it is plausible that neutrophil extracellular trap formation actively occurs in diabetic retinopathy. This case-control study investigated the clinical relevance of circulating levels of neutrophil extracellular trap components as risk factors of diabetic retinopathy, and further evaluated whether glucose induced neutrophil extracellular trap formation in vitro using whole blood from healthy volunteers. Methods: Circulating levels of DNA-histone complexes, cell free double-stranded DNA, and polymorphonuclear neutrophil elastase, considered to be markers of neutrophil extracellular trap formation, were measured in patients with diabetic retinopathy (n=28) and without (n=62) and in 28 healthy controls. Results: Circulating DNA-histone complex and polymorphonuclear neutrophil elastase levels were significantly increased in patients with diabetic retinopathy compared with those without retinopathy. Multivariable logistic regression analysis, adjusted for glycated hemoglobin levels and fasting blood glucose, revealed that DNA-histone complex and polymorphonuclear neutrophil elastase levels were significant independent risk factors of retinopathy. In vitro experiments also showed that glucose significantly increased markers of neutrophil extracellular trap formation in a dose-dependent manner. Conclusions: Markers of neutrophil extracellular trap formation were independent risk factors of diabetic retinopathy. This finding provides a new insight into the potential therapeutic and preventive approaches to dampen neutrophil extracellular trap formation.

Patiromer: A Review in Hyperkalaemia

Patiromer (Veltassa(™)) for oral suspension is a sodium-free potassium binder that is approved in the USA for the treatment of hyperkalaemia. In clinical trials, patiromer significantly reduced serum potassium levels from baseline to week 4 in patients with chronic kidney disease (CKD) and mild to severe hyperkalaemia (OPAL-HK), or CKD, mild to moderate hyperkalaemia and type 2 diabetes mellitus (AMETHYST-DN), who were receiving renin-angiotensin-aldosterone system inhibitors (RAASis; drugs that inhibit the renal excretion of potassium). Among patients in OPAL-HK who had moderate to severe hyperkalaemia at baseline and normokalaemia on patiromer and RAASis at week 4, continuing patiromer for a further 8 weeks maintained reductions in potassium levels more effectively than switching to placebo (i.e. withdrawing patiromer); consequently, fewer patiromer than placebo recipients experienced recurrent hyperkalaemia during this period. Furthermore, almost all patiromer (vs. less than half of placebo) recipients were still receiving RAASi therapy at the end of this trial. In AMETHYST-DN, the significant reduction from baseline in serum potassium levels seen at week 4 was sustained for up to 52 weeks. Patiromer was generally well tolerated in these trials, with no treatment-related serious adverse events or deaths. Commonly occurring treatment-related adverse events include mild to moderate constipation and hypomagnesaemia, and there is a low risk of hypokalaemia. In conclusion, oral patiromer is a useful new option for patients with hyperkalaemia.

Expression of autotaxin and lysophosphatidic acid receptors 1 and 3 in the developing rat lung and in response to hyperoxia

We sought to evaluate lysophosphatidic acid (LPA) signaling improvement in lung development by assessing the expression of autotaxin and LPA receptor 1 and 3 (LPAR1 and LPAR3) in the neonatal rat lung during normal perinatal development and in response to hyperoxia. In the developmental study, rats were sacrificed on days 17, 19, and 21 of gestation; on postnatal days 1, 4, and 7; and at adulthood (postnatal 9 weeks). In the hyperoxia study, 42 postnatal 4-day-old rat pups were divided into seven groups and exposed to either 85% O2 for 24, 72, or 120 h or room air for 0, 24, 72, or 120 h. The rats were then euthanized after 0, 24, 72, and 120 h of exposure. Immunofluorescence demonstrated that autotaxin, LPAR1, and LPAR3 proteins were broadly colocalized in airway epithelial cells, but mainly distributed in vascular endothelial and mesenchymal cells during the first postnatal week. The expression of autotaxin, LPAR1, and LPAR3 were increased during late gestation and then decreased after birth. Autotaxin expression and enzymatic activity were significantly increased at 72 and 120 h after exposure to hyperoxia. LPAR1 and LPAR3 expression was also increased after 120 h of hyperoxic exposure. These findings suggest that LPA-associated molecules were upregulated at birth and induced by hyperoxia in the developing rat lung. Therefore, the LPA pathway may be involved in normal lung development, including vascular development, as well as wound-healing processes of injured neonatal lung tissue, which is at risk of neonatal hyperoxic acute lung injury.

The MDM2 small-molecule inhibitor RG7388 leads to potent tumor inhibition in p53 wild-type neuroblastoma

Neuroblastoma is an aggressive pediatric malignancy which is >98% p53 wild-type at diagnosis. As a primary repressor of p53 activity and part of a p53-activated negative feedback loop, targeting of mouse double minute 2 homolog (MDM2) is an attractive therapeutic approach to reactivation of p53. Since development of the first selective MDM2 inhibitor, Nutlin-3a, newer compounds have been developed for increased potency and improved bioavailability. Herein, we sought to determine the efficacy and specificity of a second-generation MDM2 inhibitor, RG7388, in neuroblastoma cell lines and xenografts and examine its effect on the p53-independent pathway of hypoxia-inducible factor-1 alpha (HIF-1α)/vascular endothelial growth factor (VEGF). Cell viability and apoptosis studies were performed on the neuroblastoma cell lines, NGP, SH-SY5Y, LAN-5, LAN-5 si-p53 (p53 silenced), and SK-N-AS (p53 null). RG7388 potently decreased cell proliferation and activated p53-dependent apoptosis. Tumor-bearing mice treated with RG7388 demonstrated significant tumor inhibition by 59% in NGP (P=0.003), 67% in SH-SY5Y (P=0.006), and 75% in LAN-5 (P=0.0019) p53 wild-type xenograft tumors, but no inhibitory effect on LAN-5 si-p53 or SK-N-AS p53-silenced/null xenograft tumors. Moreover, RG7388 was found to inhibit the p53-independent pathway of HIF-1α/VEGF with decreased gene expression and alteration of angiogenesis. Our study supports the further evaluation of RG7388 as a novel treatment option in p53 wild-type neuroblastoma at diagnosis and relapse.

High normal albuminuria is associated with arterial stiffness and carotid atherosclerosis in Korean patients with type 2 diabetes

BACKGROUND AND AIMS

Current evidence suggests that high normal albuminuria is significantly associated with increased cardiovascular risk. This study investigated the association between urine albumin-to-creatinine ratio (ACR) within the normal range and subclinical atherosclerosis in Korean patients with type 2 diabetes.

METHODS AND RESULTS

This cross-sectional study involved 521 type 2 diabetic patients with normoalbuminuria. Brachial-ankle pulse wave velocity (baPWV) measurement and ultrasound assessment of carotid atherosclerosis was done. Subclinical atherosclerosis was assessed by the presence of high baPWV (>1682 cm/s), carotid atherosclerosis (intima-media thickness >0.8 mm or the presence of plaques), and carotid stenosis (≥50% of luminal narrowing). Across the tertiles of ACR, there was a trend for an increasing prevalence of high baPWV (16.8%, 20.0%, and 38.2%, P < 0.001), carotid atherosclerosis (46.9%, 55.4%, and 64.7%, P < 0.001), and carotid stenosis (12.7%, 16.0%, and 30.1%, P < 0.001). In multivariate analysis, patients in the highest ACR tertile had an odds ratio of 2.05 (95% confidence interval [CI], 1.13-3.72, P = 0.019) for high baPWV, 1.78 (95% CI, 1.08-2.93, P = 0.024) for carotid atherosclerosis, and 2.72 (95% CI, 1.44-5.11, P = 0.002) for carotid stenosis compared to those in the lowest tertile. The relation of ACR with carotid atherosclerosis and stenosis remained significant even in patients without diabetic retinopathy.

CONCLUSION

High normal albuminuria was significantly associated with atherosclerotic vascular changes, independent of retinopathy and other cardiovascular risk factors. High normal albuminuria may be an early marker for subclinical atherosclerosis in type 2 diabetes.

Clinical significance of serum bilirubin and gamma-glutamyltransferase levels on coronary atherosclerosis assessed by multidetector computed tomography

BACKGROUND AND AIMS

Low bilirubin and high gamma-glutamyltransferase (GGT), which are endogenous markers of oxidative stress, confer a higher risk of cardiovascular disease (CVD). We investigated associations between serum concentrations of bilirubin, GGT and coronary atherosclerosis.

METHODS AND RESULTS

A cross-sectional analysis was performed on 1520 subjects who underwent multidetector computed tomography scans. Coronary atherosclerosis was assessed by coronary artery calcium score (CACS) and obstructive coronary artery disease (OCAD), was defined as the presence of coronary artery stenosis of ≥50%. Total bilirubin (TB) level was negatively correlated with CACS and coronary stenosis whereas GGT level was positively correlated with CACS in men. However, there was no correlation between TB, GGT levels and either CACS or coronary artery stenosis in women. In a multivariate-adjusted model, TB level was inversely associated with a CACS > 100 [odds ratio (OR) per log standard deviation (SD), 0.67; 95% confidence interval (CI), 0.52-0.87], and OCAD (OR per log SD, 0.77; 95% CI, 0.62-0.95) in men. By contrast, GGT level was positively associated with a CACS > 100 (OR per log SD, 1.35; 95% CI, 1.05-1.73) but not with OCAD. Adding TB and GGT to the conventional risk factors increased predictive accuracy for CACS > 100 (net reclassification improvement index [NRI] = 13.1%, P = 0.026; integrated discrimination index [IDI] = 0.024, P = 0.001) and for OCAD (NRI = 12.6%, P = 0.026; IDI = 0.010, P = 0.013).

CONCLUSIONS

Low TB and high GGT levels were concomitantly associated with coronary atherosclerosis in Korean men. Future studies are needed to elucidate the causal associations of TB and GGT with CVD.

Analysis of aberrantly spliced transcripts of a novel de novo GNAS mutant in a male with albright hereditary osteodystrophy and PHP1A

Pseudohypoparathyroidism (PHP) is a genetic disorder due to target-organ unresponsiveness to parathyroid hormone (PTH). PHP type 1A (PHP1A) is an autosomal dominant disease characterized by Albright hereditary osteodystrophy (AHO) and PTH resistance caused by defects at the GNAS locus. We analyzed the GNAS gene in a male with typical AHO and elevated PTH levels. We identified a novel de novo heterozygous mutation at the splice donor site in intron-7 (IVS7+1G>A, c.585+1G>A) of the GNAS gene. No GNAS mutations were detected in his parents. Our patient was diagnosed with PHP1A due to a heterozygous de novo mutation in the GNAS gene. Reverse transcriptase (RT) PCR analysis and sequencing revealed that this de novo splice mutation generated alternative splicing errors leading to the formation of 2 mutant transcripts: one with exon-7 deleted, the other with whole intron-7 included. To investigate whether these aberrantly spliced transcripts were stable, we assessed the differential expression of GNAS mRNAs in the proband's blood by real-time quantitative RT-PCR. In the proband, the relative expression levels of wild-type, exon-7-deleted, and intron-7-included GNAS mRNAs were 0.21, 6.12E-07, and 1.08E-04, respectively, relative to wild-type GNAS mRNA from a healthy control (set at 1.0). This suggests that this novel de novo splicing mutation generates rapidly decaying mutant transcripts, which might affect stimulatory G-protein activity and give rise to this sporadic case. In conclusion, this is an interesting report of aberrantly spliced mRNAs from a de novo splice mutation of the GNAS gene causing PHP1A in a male.

Which tissues are best for microbiological diagnosis in patients with pyogenic vertebral osteomyelitis undergoing needle biopsy?

Identification of the causative microorganism is important in the management of pyogenic vertebral osteomyelitis (PVO). The aim of this study was to investigate whether culture positive rates differ between needle biopsy sites in patients with PVO, and which tissues are best for microbiological diagnosis. Between January 2005 and December 2013, we conducted a retrospective cohort study of PVO patients who had soft-tissue abscesses (paraspinal or psoas abscesses) and who received needle biopsy for microbiological diagnosis. Needle biopsy sites were classified into two anatomical categories: vertebral bodies, or soft tissues (intervertebral discs, paraspinal abscesses, or psoas abscesses). A generalized estimating equation model was developed to identify factors associated with tissue-culture positivity. During the study period a total of 136 tissues were obtained by needle biopsy from 128 PVO patients with soft-tissue abscesses. The culture positive rates of vertebral bodies and soft tissues were 39.7% (29/73), and 63.5% (40/63), respectively (p < 0.05). In a multivariate analysis, male gender (adjusted odds ratio (aOR) 2.24, 95% CI 1.00-5.02), higher C-reactive protein (aOR 1.07, 95% CI 1.01-1.15), positive blood culture (aOR 2.57, 95% CI 1.01-6.59), and soft tissues as biopsy site compared with vertebral bodies (aOR 2.28, 95% CI 1.08-4.78) were independent factors associated with tissue culture positivity. Soft tissues were the best sites for microbiological diagnosis in PVO patients undergoing needle biopsy.

A reusable robust radio frequency biosensor using microwave resonator by integrated passive device technology for quantitative detection of glucose level

A reusable robust radio frequency (RF) biosensor with a rectangular meandered line (RML) resonator on a gallium arsenide substrate by integrated passive device (IPD) technology was designed, fabricated and tested to enable the real-time identification of the glucose level in human serum. The air-bridge structure fabricated by an IPD technology was applied to the RML resonator to improve its sensitivity by increasing the magnitude of the return loss (S21). The resonance behaviour, based on S21 characteristics of the biosensor, was analysed at 9.20 GHz with human serum containing different glucose concentration ranging from 148-268 mg dl(-1), 105-225 mg dl(-1) and at a deionised (D) water glucose concentration in the range of 25- 500 mg dl(-1) for seven different samples. A calibration analysis was performed for the human serum from two different subjects and for D-glucose at a response time of 60 s; the reproducibility, the minimum shift in resonance frequency and the long-term stability of the signal were investigated. The feature characteristics based on the resonance concept after the use of serum as an analyte are modelled as an inductor, capacitor and resistor. The findings support the development of resonance-based sensing with an excellent sensitivity of 1.08 MHz per 1 mg dl(-1), a detection limit of 8.01 mg dl(-1), and a limit of quantisation of 24.30 mg dl(-1).

Prevalence of blaZ gene types and the cefazolin inoculum effect among methicillin-susceptible Staphylococcus aureus blood isolates and their association with multilocus sequence types and clinical outcome

Cefazolin treatment failures have been described for bacteraemia caused by methicillin-susceptible Staphylococcus aureus (MSSA) with type A β-lactamase and inoculum effect (InE). We investigated the prevalence of blaZ (β-lactamase) gene types and a cefazolin InE among MSSA blood isolates in South Korea and evaluated their association with specific genotypes. The clinical impact of the cefazolin InE was also evaluated. A total of 220 MSSA isolates were collected from a prospective cohort study of S. aureus bacteraemia. A pronounced InE with cefazolin was defined as a ≥4-fold increase in the minimum inhibitory concentration (MIC) between a standard and high inoculum, resulting in a non-susceptible MIC. Sequencing of blaZ and multilocus sequence typing (MLST) were performed. Clinical outcomes were assessed in 77 patients treated with cefazolin. The blaZ gene was detected in 92 % of the 220 MSSA isolates. Type C β-lactamase was the most common (53 %), followed by type B (20 %) and type A (17 %). Certain genotypes were significantly associated with specific β-lactamase types (notably, ST30 and type A β-lactamase). A pronounced cefazolin InE was observed in 13 % of isolates. Most of these (79 %) expressed type A β-lactamase and ST30 was the predominant (55 %) clone amongst them. Cefazolin treatment failure was not observed in patients infected with strains exhibiting a pronounced InE. These strains had no impact on other clinical outcomes. In conclusion, the prevalence of a pronounced InE with cefazolin could be dependent upon distributions of MSSA genotypes. Cefazolin can likely be used for the treatment of MSSA bacteraemia (except endocarditis), without consideration of an InE.

Electro-optic switching in phase-discontinuity complementary metasurface twisted nematic cell

Electro-optic switching of refraction is experimentally demonstrated in a phase-discontinuity complementary metasurface twisted nematic cell. The phase-discontinuity complementary metasurface is fabricated by focused-ion-beam milling, and a twisted nematic cell is constructed with complementary V-shape slot antenna metasurface. By application of an external voltage, switching is achieved between ordinary refraction and extraordinary refraction satisfying the generalized Snell's law. It has a strong implication for applications in spatial light modulation and wavelength division multiplexer/demultiplexer in a near-IR spectral range.

Outbreak among healthy newborns due to a new variant of USA300-related meticillin-resistant Staphylococcus aureus

BACKGROUND

The prevalence of community-associated meticillin-resistant Staphylococcus aureus (CA-MRSA) is increasing throughout the world and is an important cause of skin and soft tissue infection (SSTI) in children and neonates.

AIM

To describe the successful control of an outbreak caused by a new strain of CA-MRSA in a newborn nursery.

METHODS

The investigation of the outbreak in July 2012 is reported with the control measures taken. Molecular typing of the MRSA isolates was performed.

FINDINGS

An outbreak of SSTI caused by CA-MRSA occurred in a newborn nursery. Six neonates were infected in a one-month period [infection rate: 8.5% (6/71)]. A new variant of CA-MRSA was responsible, which was characterized as USA300-related, Panton-Valentine Leucocidin (PVL) positive, arginine catabolic mobile element (ACME) negative, sequence type 8 (ST8), staphylococcal cassette chromosome mec (SCCmec) type IVa, agr type I and spa type t008. The outbreak among term neonates followed a rapid transmission pattern and was successfully controlled by implementing various outbreak control measures, including universal chlorhexidine bathing.

CONCLUSION

This is the first report of a hospital outbreak caused by a USA300-related CA-MRSA clone in Korea. Early recognition and reinforcement of infection control measures are important in decreasing transmission of CA-MRSA in a hospital setting.

Preliminary physical and electromagnetic design for the injector of the heavy ion superconducting linac

The Rare Isotope Science Project in Korea has developed a high current heavy ion accelerator using superconducting linacs. A normal conducting injector system was proposed to supply heavy ions to the superconducting driver linac. A beam physics and engineering design study was performed, and the beam dynamics of the injector was simulated. Optimized beam transmission and emittance were obtained from the beam dynamics simulation. Various normal conducting bunchers, such as multi-harmonic buncher, velocity equalizer, radiofrequency quadrupole, and re-bunchers, will be used and have been electromagnetically calculated.

Experimental validation of a novel compact focusing scheme for future energy-frontier linear lepton colliders

A novel scheme for the focusing of high-energy leptons in future linear colliders was proposed in 2001 [P. Raimondi and A. Seryi, Phys. Rev. Lett. 86, 3779 (2001)]. This scheme has many advantageous properties over previously studied focusing schemes, including being significantly shorter for a given energy and having a significantly better energy bandwidth. Experimental results from the ATF2 accelerator at KEK are presented that validate the operating principle of such a scheme by demonstrating the demagnification of a 1.3 GeV electron beam down to below 65 nm in height using an energy-scaled version of the compact focusing optics designed for the ILC collider.

Reflection resonance switching in metamaterial twisted nematics cell

Electric switching of reflection resonances at near-IR spectral range is experimentally demonstrated in a reflective metamaterial twisted nematic liquid crystal cell. Reflective metamaterial composed of nano-sized double-split ring resonator aperture is fabricated by a focused ion beam milling. Two-fold rotational symmetry of double-split ring resonators allows for two orthogonal polarization-dependent reflection resonances in the reflective metamaterial. With an external voltage of 10V across 12μm cell gap, a full switching is achieved between two reflection resonances. Dynamic measurements show the time constants of switch-on and switch-off are in the order of 100ms and 10ms, respectively.

Obesity, diabetes, and survival outcomes in a large cohort of early-stage breast cancer patients

BACKGROUND

To determine the relationship between obesity, diabetes, and survival in a large cohort of breast cancer patients receiving modern chemotherapy and endocrine therapy.

PATIENTS AND METHODS

We identified 6342 patients with stage I-III breast cancer treated between 1996 and 2005. Patients were evaluated according to body mass index (BMI) category and diabetes status.

RESULTS

In a multivariate model adjusted for body mass index, diabetes, medical comorbidities, patient- and tumor-related variables, and adjuvant therapies, relative to the normal weight, hazard ratios (HRs) for recurrence-free survival (RFS), overall survival (OS), and breast cancer-specific survival (BCSS) for the overweight were 1.18 [95% confidence interval (CI) 1.02-1.36], 1.20 (95% CI 1.00-1.42), and 1.21 (95% CI 0.98-1.48), respectively. HRs for RFS, OS, and BCSS for the obese were 1.13 (95% CI 0.98-1.31), 1.24 (95% CI 1.04-1.48), and 1.23 (95% CI 1.00-1.52), respectively. Subset analyses showed these differences were significant for the ER-positive, but not ER-negative or HER2-positive, groups. Relative to nondiabetics, HRs for diabetics for RFS, OS, and BCSS were 1.21 (95% CI 0.98-1.49), 1.39 (95% CI 1.10-1.77), and 1.04 (95% CI 0.75-1.45), respectively.

CONCLUSIONS

In patients receiving modern adjuvant therapies, obesity has a negative impact on RFS, OS, and BCSS; and diabetes has a negative impact on RFS and OS. Control of both may be important to improving survival in obese and diabetic breast cancer patients.

Delayed post-hypoxic leucoencephalopathy presenting akinetic mutism after traumatic cervical cord injury: a case report

Delayed post-hypoxic leucoencephalopathy is a demyelinating syndrome characterized by acute onset of neuropsychiatric symptoms including parkinsonism or akinetic mutism that occurs days to weeks after recovery from cerebral hypo-oxygenation. We encountered a patient who presented with an akinetic mute state late after cervical cord injury without a definite hypoxic event.

Fabrication of polarization-dependent reflective metamaterial by focused ion beam milling

By focused ion beam milling, we fabricated near-IR reflective metamaterials consisting of nano-aperture arrays. Optimum parameters of ion beam current and accelerating voltage in the fabrication process are obtained. Nano-apertures constituting reflective metamaterial are successfully milled, and possess a reflective resonance in the near-IR spectral range. With a double-split-ring resonator structure for the nano-aperture, the intensity reflection at resonance is rendered polarization dependent. It is found that the point group symmetry of the nano-aperture array determines the amount of anisotropy in the intensity reflection. Finite-difference time-domain simulation was adopted to identify details of nano-aperture metastructures transferred from nano-aperture patterns by the focused ion beam milling.

[Grass genome and chromosome sets evolution]

This paper briefly discusses the mechanisms by which either diploid 2n or basal chromosome number x change during grass karyotype evolution.