Evaluation of inhalation risk during quarantine work with quaternary ammonium compounds-based disinfectant

Quarantine work is widely recognized as an indispensable endeavor in curbing the propagation of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Furthermore, the heavy workload places workers at a heightened risk of chemical exposure and respiratory damage. Consequently, it is paramount to systematically perform health risk assessments and meticulously oversee the work by wearing personal protective equipment to minimize these risks. To assess the inhalation exposure, this study examined data on disinfectant exposure from quarantine professional users who utilized disinfectants containing quaternary ammonium compounds. Through a survey of 6,199 cases conducted by 300 quarantine professional users who actively engaged in quarantine work, we assembled a database of exposure factors derived from their utilization of spray-type disinfectants for quarantine purposes. Based on these data, we formulated an inhalation exposure algorithm, which considers the time-weighted average (TWA) air concentrations. The test results demonstrated that the industrial-grade respirator mask could prevent a minimum of 68.3 % of particles, reducing respiratory exposure. Consequently, the hazard quotient (HQ) due to disinfectant exposure also decreased. This research is essential in safeguarding the safety and health of professional users engaged in quarantine-related tasks. By implementing strict measures like health risk assessments and personal protective equipment, individuals with quarantine experience can safely carry out their quarantine work. The results of this study are expected to serve as a framework for improving policies and regulations concerning quarantine work and safeguarding the health of professional users.

Autolysis of Pseudomonas aeruginosa Quorum-Sensing Mutant Is Suppressed by Staphylococcus aureus through Iron-Dependent Metabolism

Microorganisms usually coexist as a multifaceted polymicrobial community in the natural habitats and at mucosal sites of the human body. Two opportunistic human pathogens, Pseudomonas aeruginosa and Staphylococcus aureus commonly coexist in the bacterial infections for hospitalized and/or immunocompromised patients. Here, we observed that autolysis of the P. aeruginosa quorum-sensing (QS) mutant (lasRmvfR) was suppressed by the presence of the S. aureus cells in vitro. The QS mutant still displayed killing against S. aureus cells, suggesting the link between the S. aureus-killing activity and the autolysis suppression. Independent screens of the P. aeruginosa transposon mutants defective in the S. aureus-killing and the S. aureus transposon mutants devoid of the autolysis suppression revealed the genetic link between both phenotypes, suggesting that the iron-dependent metabolism involving S. aureus exoproteins might be central to both phenotypes. The autolysis was suppressed by iron treatment as well. These results suggest that the interaction between P. aeruginosa and S. aureus might be governed by mechanisms that necessitate the QS circuitry as well as the metabolism involving the extracellular iron resources during the polymicrobial infections in the human airway.

The Microbiome Matters: Its Impact on Cancer Development and Therapeutic Responses

In the evolving landscape of cancer research, the human microbiome emerges as a pivotal determinant reshaping our understanding of tumorigenesis and therapeutic responses. Advanced sequencing technologies have uncovered a vibrant microbial community not confined to the gut but thriving within tumor tissues. Comprising bacteria, viruses, and fungi, this diverse microbiota displays distinct signatures across various cancers, with most research primarily focusing on bacteria. The correlations between specific microbial taxa within different cancer types underscore their pivotal roles in driving tumorigenesis and influencing therapeutic responses, particularly in chemotherapy and immunotherapy. This review amalgamates recent discoveries, emphasizing the translocation of the oral microbiome to the gut as a potential marker for microbiome dysbiosis across diverse cancer types and delves into potential mechanisms contributing to cancer promotion. Furthermore, it highlights the adverse effects of the microbiome on cancer development while exploring its potential in fortifying strategies for cancer prevention and treatment.

A TetR family regulator of an RND efflux system that directs artemisinin resistance in Vibrio cholerae

Artemisinin (ARS) displayed bactericidal activity against Vibrio cholerae. To assess the mechanistic details of its antibacterial action, we have isolated V. cholerae mutants with enhanced ARS resistance and identified a gene (VCA0767) whose loss-of-function resulted in the ARS resistance phenotypes. This gene (atrR) encodes a TetR family transcriptional regulator, and its deletion mutant displayed the reduction in ARS-induced ROS formation and DNA damage. Transcriptomic analysis revealed that the genes encoding a resistance-nodulation-cell division (RND) efflux pump operon (vexRAB) and the outer membrane component (tolC) were highly upregulated in the artR mutant, suggesting that AtrR might act as a negative regulator of this operon and tolC. Gene deletion of vexR, vexB, or tolC abrogated the ARS resistance of the atrR mutant, and more importantly, the ectopic expression of VexAB-TolC was sufficient for the ARS resistance, indicating that the increased expression of the VexAB-TolC efflux system is necessary and sufficient for the ARS resistance of the atrR mutant. The cytoplasmic accumulation of ARS was compromised in the vexBtolC mutant, suggesting that the VexAB-TolC might be the primary efflux system exporting ARS to reduce its toxicity inside of the bacterial cells. The atrR mutant displayed resistance to erythromycin as well in a VexR-dependent manner. This result suggests that AtrR may act as a global regulator responsible for preventing intracellular accumulation of toxic chemicals by enhancing the RND efflux system.IMPORTANCEDrug efflux protein complexes or efflux pumps are considered as the major determinants of multiple antimicrobial resistance by exporting a wide range of structurally diverse antibiotics in bacterial pathogens. Despite the clinical significance of the increased expression of the efflux pumps, their substrate specificity and regulation mechanisms are poorly understood. Here, we demonstrated that VexAB-TolC, a resistance-nodulation-cell division (RND) efflux pump of V. cholerae, is responsible for the resistance to artemisinin (ARS), an antimalarial drug with bactericidal activity. Furthermore, we newly identified AtrR, a TetR family repressor, as a global regulator for VexRAB and the common outer membrane channel, TolC, where VexR functions as the pathway-specific regulator of the vexAB operon. Our findings will help improve our insight into a broad range of substrate specificity of the VexAB-TolC system and highlight the complex regulatory networks of the multiple RND efflux systems during V. cholerae pathogenesis.

An iron-chelating sulfonamide identified from Drosophila-based screening for antipathogenic discovery

We exploited bacterial infection assays using the fruit fly Drosophila melanogaster to identify anti-infective compounds that abrogate the pathological consequences in the infected hosts. Here, we demonstrated that a pyridine-3-N-sulfonylpiperidine derivative (4a) protects Drosophila from the acute infections caused by bacterial pathogens including Pseudomonas aeruginosa. 4a did not inhibit the growth of P. aeruginosa in vitro, but inhibited the production of secreted toxins such as pyocyanin and hydrogen cyanide, while enhancing the production of pyoverdine and pyochelin, indicative of iron deprivation. Based on its catechol moiety, 4a displayed iron-chelating activity in vitro toward both iron (II) and iron (III), more efficiently than the approved iron-chelating drugs such as deferoxamine and deferiprone, concomitant with more potent antibacterial efficacy in Drosophila infections and unique transcriptome profile. Taken together, these results delineate a Drosophila-based strategy to screen for antipathogenic compounds, which interfere with iron uptake crucial for bacterial virulence and survival in host tissues.

Artemisinin displays bactericidal activity via copper-mediated DNA damage

Artemisinin (ARS) and its semi-synthetic derivatives are effective drugs to treat malaria and possess multiple therapeutic activities based on their endoperoxide bridge. Here, we showed that ARS displayed antibacterial efficacy in Drosophila systemic infections caused by bacterial pathogens but killed only Vibrio cholerae (VC) in vitro, involving reactive oxygen species (ROS) generation and/or DNA damage. This selective antibacterial activity of ARS was attributed to the higher intracellular copper levels in VC, in that the antibacterial activity was observed in vitro upon addition of cuprous ions even against other bacteria and was compromised by the copper-specific chelators neocuproine (NC) and triethylenetetramine (TETA) in vitro and in vivo. We suggest that copper can enhance or reinforce the therapeutic activities of ARS to be repurposed as an antibacterial drug for the treatment of bacterial infections.

A phage protein-derived antipathogenic peptide that targets type IV pilus assembly

Phage-inspired antibacterial discovery is a new approach that recruits phages in search for antibacterials with new molecular targets, in that phages are the biological entities well adapted to hijack host bacterial physiology in favor of their own thrive. We previously observed that phage-mediated twitching motility inhibition was effective to control the acute infections caused by Pseudomonas aeruginosa and that the motility inhibition was attributed to the delocalization of PilB, the type IV pilus (TFP) assembly ATPase by binding of the 136-amino acid (aa) phage protein, Tip. Here, we created a series of truncated and point-mutant Tip proteins to identify the critical residues in the Tip bioactivity: N-terminal 80-aa residues were dispensable for the Tip activity; we identified that Asp82, Leu84, and Arg85 are crucial in the Tip function. Furthermore, a synthetic 15-aa peptide (P1) that corresponds to Leu73 to Ala87 is shown to suffice for PilB delocalization, twitching inhibition, and virulence attenuation upon exogenous administration. The transgenic flies expressing the 15-aa peptide were resistant to P. aeruginosa infections as well. Taken together, this proof-of-concept study reveals a new antipathogenic peptide hit targeting bacterial motility and provides an insight into antibacterial discovery targeting TFP assembly.

An antipathogenic compound that targets the OxyR peroxide sensor in Pseudomonas aeruginosa

Introduction

Antipathogenic or antivirulence strategy is to target a virulence pathway that is dispensable for growth, in the hope to mitigate the selection for drug resistance.

Hypothesis/Gap Statment

Peroxide stress responses are one of the conserved virulence pathways in bacterial pathogens and thus good targets for antipathogenic strategy.

Aim

This study aims to identify a new chemical compound that targets OxyR, the peroxide sensor required for the full virulence of the opportunistic human pathogen, Pseudomonas aeruginosa.

Methodology

Computer-based virtual screening under consideration of the ‘eNTRy’ rules and molecular docking were conducted on the reduced form of the OxyR regulatory domain (RD). Selected hits were validated by their ability to phenocopy the oxyR null mutant and modulate the redox cycle of OxyR.

Results

We first isolated three robust chemical hits that inhibit OxyR without affecting prototrophic growth or viability. One (compound 1) of those affected the redox cycle of OxyR in response to H₂O₂ treatment, in a way to impair its function. Compound 1 displayed selective antibacterial efficacy against P. aeruginosa in Drosophila infection model, without antibacterial activity against Staphylococcus aureus.

Conclusion

These results suggest that compound 1 could be an antipathogenic hit inhibiting the P. aeruginosa OxyR. More importantly, our study provides an insight into the computer-based discovery of new-paradigm selective antibacterials to treat Gram-negative bacterial infections presumably with few concerns of drug resistance.

Nitrate Respiration Promotes Polymyxin B Resistance in Pseudomonas aeruginosa

Aims: Polymyxin B (PMB) is known to require reactive oxygen species (ROS) for its bactericidal activity, but the mechanism of PMB resistance in various Pseudomonas aeruginosa strains has been poorly understood. This study examined the role of nitrate respiration (NR) of some P. aeruginosa strains in the PMB resistance. Results: We observed that the minimum inhibitory concentration (MIC) value of PMB against P. aeruginosa PA14 was eightfold reduced (from 2.0 to 0.25 μg/mL) by agitation, but not against P. aeruginosa PAO1 (from 2.0 to 1.0 μg/mL). Transcriptomic and phenotypic analyses using both strains and their NR mutants revealed that the higher NR in PAO1 than in PA14 accounted for the higher MIC value (i.e., PMB resistance) of PAO1, which was sufficient to compromise the antibacterial activity of PMB in Drosophila infections. We also confirmed the contribution of the NR to the PMB resistance is independent of the major catalase (KatA), suggesting that the NR might affect the ROS generation rather than the ROS disintegration. Furthermore, this PMB resistance was relatively common among clinical P. aeruginosa isolates and correlated with higher NR in those strains. Innovation and Conclusion: These results suggest P. aeruginosa strains could display intrinsic resistance to antibiotics in clinical settings and that NR is a crucial factor in the intrinsic antibiotic resistance, and also provide an insight into another key target for successful antibiotic treatment of P. aeruginosa infections. Antioxid. Redox Signal. 34, 442-451.

A case report of infectious scleritis with corneal ulcer caused by Scedosporium aurantiacum

RATIONALE

Scedosporium species is rare pathogen of ocular infection. The accurate diagnosis is delaying in many cases and the clinical prognosis is poor due to its resistance to antifungal agents. This report describes a patient with infectious scleritis and corneal ulcer caused by Scedosporium auranticum infection who required enucleation to control the infection.

PATIENT CONCERNS

A 70-year-old woman visited our clinic after experiencing ocular discomfort in her right eye for 4 days after minor ocular trauma, with soil exposure.

DIAGNOSES

Scedosporium species was isolated from a culture of corneal tissue, Scedosporium aurantiacum was identified in a culture of necrotic tissue.

INTERVENTIONS

She was started on treatment with antifungal agents, including topical amphotericin B and systemic fluconazole, but her ocular condition did not improve. Although the lesion showed temporary improvement, ocular pain and corneal ulcer recurred 3 months later. Evisceration was performed due to corneal perforation, and enucleation was also performed for dehiscence of the conjunctiva and scleral necrosis.

OUTCOMES

After enucleation, postoperative systemic voriconazole treatment controlled the infection without recurrence.

LESSONS

S aurantiacum keratitis is difficult to eradicate, even with several months of treatment with systemic and topical antifungal agents, and tends to progress to scleritis. The infection can be terminated by the orbital enucleation. Infection with this rare organism should be included in the differential diagnosis of patients with severe infectious keratitis.

Differential expression of the major catalase, KatA in the two wild type Pseudomonas aeruginosa strains, PAO1 and PA14

KatA is the major catalase required for hydrogen peroxide (H₂O₂) resistance and acute virulence in Pseudomonas aeruginosa PA14, whose transcription is governed by its dual promoters (katAp1 and katAp2). Here, we observed that KatA was not required for acute virulence in another wild type P. aeruginosa strain, PAO1, but that PAO1 exhibited higher KatA expression than PA14 did. This was in a good agreement with the observation that PAO1 was more resistant than PA14 to H₂O₂ as well as to the antibiotic peptide, polymyxin B (PMB), supposed to involve reactive oxygen species (ROS) for its antibacterial activity. The higher KatA expression in PAO1 than in PA14 was attributed to both katAp1 and katAp2 transcripts, as assessed by S1 nuclease mapping. In addition, it was confirmed that the PMB resistance is attributed to both katAp1 and katAp2 in a complementary manner in PA14 and PAO1, by exploiting the promoter mutants for each -10 box (p1m, p2m, and p1p2m). These results provide an evidence that the two widely used P. aeruginosa strains display different virulence mechanisms associated with OxyR and Anr, which need to be further characterized for better understanding of the critical virulence pathways that may differ in various P. aeruginosa strains.

Phage-Derived Antibacterials: Harnessing the Simplicity, Plasticity, and Diversity of Phages

Despite the successful use of antibacterials, the emergence of multidrug-resistant bacteria has become a serious threat to global healthcare. In this era of antibacterial crisis, bacteriophages (phages) are being explored as an antibacterial treatment option since they possess a number of advantages over conventional antibacterials, especially in terms of specificity and biosafety; phages specifically lyse target bacteria while not affecting normal and/or beneficial bacteria and display little or no toxicity in that they are mainly composed of proteins and nucleic acids, which consequently significantly reduces the time and cost involved in antibacterial development. However, these benefits also create potential issues regarding antibacterial spectra and host immunity; the antibacterial spectra being very narrow when compared to those of chemicals, with the phage materials making it possible to trigger host immune responses, which ultimately disarm antibacterial efficacy upon successive treatments. In addition, phages play a major role in horizontal gene transfer between bacterial populations, which poses serious concerns for the potential of disastrous consequences regarding antibiotic resistance. Fortunately, however, recent advancements in synthetic biology tools and the speedy development of phage genome resources have allowed for research on methods to circumvent the potentially disadvantageous aspects of phages. These novel developments empower research which goes far beyond traditional phage therapy approaches, opening up a new chapter for phage applications with new antibacterial platforms. Herein, we not only highlight the most recent synthetic phage engineering and phage product engineering studies, but also discuss a new proof-of-concept for phage-inspired antibacterial design based on the studies undertaken by our group.

Redirecting an Anticancer to an Antibacterial Hit Against Methicillin-Resistant Staphylococcus aureus

YM155 is a clinically evaluated anticancer with a fused naphthoquinone-imidazolium scaffold. In this study, we demonstrated that based on weak or cryptic antibacterial activity of YM155 against methicillin-resistant Staphylococcus aureus (MRSA) (MIC of 50 μg/ml), some congeneric compounds with short alkyl chains (e.g., c5 with a hexyl chain) at the N3 position of the scaffold, displayed more potent antibacterial activity against MRSA (MIC of 3.13 μg/ml), which is in a clinically achievable range. Their antibacterial activity was evident against Gram-negative bacteria, only in the presence of the outer membrane-permeabilizing agent, polymyxin B. The antibacterial efficacy of c5 was confirmed using the Drosophila systemic infection model. We also characterized five spontaneous c5-resistant MRSA mutants that carry mutations in the ubiE gene, for quinone metabolism and respiratory electron transfer, and subsequently exhibited reduced respiration activity. The antibacterial activity of c5 was compromised either by an antioxidant, N-acetylcysteine, or in an anaerobic condition. These suggest that the antibacterial mechanism of c5 involves the generation of reactive oxygen species (ROS), presumably during respiratory electron transport. This study provides an insight into "drug redirecting," through a chemical modification, based on an ROS-generating pharmacophore.

Abstract P1-12-02: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Chung IY, Hur H, Lee J, Lee JW, Youn HJ, Han K, Kim NW, Jung S-Y, Kim Z, Kim KS, Lee MH, Han S-H, Jung SH. Withdrawn [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 P1-12-02.

Abstract P2-14-21: Not presented

This abstract was not presented at the conference.

Citation Format: Lee S, Ahn SH, Lee JW, Chung IY, Ko BS, Kim HJ, Kim J, Shon G, Son BH. Not presented [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 P2-14-21.

Abstract P6-09-09: Analysis of serial circulating tumor cell count during neoadjuvant systemic therapy in breast cancer patients

Background: We aimed to evaluate the clinical implication of circulating tumor cell (CTC) counts in correlation with prognosis and radiologic/pathologic response to therapy in locally advanced breast cancer patients undergoing preoperative systemic therapy.

Methods: From Feb 2014 to May 2017, 207 patients without distant metastasis were prospectively enrolled from AMC. CTC counts were analyzed before-during-after the therapy. CTC isolation was performed using a SMART BIOPSY™ SYSTEM Isolation kit (Cytogen, Inc., Seoul, Korea). Recurrence-free and overall survival was analyzed according to CTC counts.

Result: The mean follow-up period was 22.46 months and mean age was 46.48 years. One or more CTC was identified in 132 of 203 patients(65.0%) before NST, in 135 of 186 patients(72.0%) during NST and 103 of 171 patients(60.2%) after NST. Initial tumor burden at diagnosis -tumor size, lymph node metastasis- was not correlated with CTC positivity. Overall, CTC count ((≥1 CTC, ≥2 CTCs, and ≥5 CTCs) was not correlated with response to therapy. Using RECIST criteria, 86.5% (179/204) were responders (complete, partial response, CR/PR) and 12.1% (25/204) were non-responders (stable, progressive disease, SD/PD). 14.5% (30/207) showed a pathologic complete response (pCR), yet no association was found between CTC count/changes and radiologic/pathologic response to therapy. Also, CTC count was not correlated with prognosis among the whole population. However, HR+ tumors, CTC detection before NST was significantly associated with treatment response by RECIST criteria (responder vs. non-responder) (p=0.003, p=0.017 and p=0.023, respectively).

Conclusions: Our findings support limited value of CTC count for locally advanced breast cancers undergoing neoadjuvant systemic therapy.

Citation Format: Gwark S-C, Kim J, Kim YH, Kim MS, Park JY, Lee SB, Sohn G, Chung IY, Ko BS, Kim HJ, Lee JW, Son BH, Ahn SH. Analysis of serial circulating tumor cell count during neoadjuvant systemic therapy in breast cancer patients [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 P6-09-09.

Abstract P2-08-22: Clinical implication of HER2/neu status in hormone receptor positive pure mucinous breast cancer

Background: Mucinous carcinoma of the breast is a rare type of breast cancer with favorable outcome compared with other types of breast cancer. The current guideline does not recommend chemotherapy/anti-HER2 therapy for mucinous breast cancer with hormone receptor-positive subtype regardless of HER2/neu status. In this study, we evaluated the survival of pure mucinous breast cancer according to tumor stage and subtype.

Methods: Between 1989 and 2014, in Asan Medical Center, Korea, total 473 pure mucinous carcinomas (stage I-III) undergone curative surgery were reviewed retrospectively. 5yr disease-free and overall survival were analyzed according to size, lymph node metastasis, hormone receptor/HER2 status and given therapy.

Result: Total of 473 patients with pure mucinous breast cancer were analyzed and median follow-up duration was 78.00 months. 439 patients were hormone receptor-positive, 374 were node negative, 55 were HER2/neu positive. Among 374 patients with hormone receptor-positive and node-negative, tumor size was <1cm in 46 patients, 1-2.9cm in 259 patients, ≥3cm in 69 patients. In HR-positive/Node-positive BCs, 90.8%(59/65)were given chemotherapy and 35.3%(6/17) were also given trastuzumab. Sixteen patients given trastuzumab were only included in the analysis to assess the benefit of trastuzumab among HER2 positive BCs.

Overall, 5-year disease-free survival (DFS) rate was 94.1% and the 5-year overall survival (OS) rate was 95.9%. Using Cox regression analysis, lymph node metastasis was the only significant prognostic factor for both DFS (HR4.0, 95%CI:1.8-9.0, p=0.001) and OS (HR3.5, 95%CI:1.3-8.9, p=0.008). Among HR-positive/node-negative with tumor size ≥3cm, HER2/neu positivity was only significantly associated with 5yr-DFS (71.4% in HER2/neu+ vs. 96.4% in HER2/neu-, HR9.5, 95%CI:1.3-67.5, p=0.024). This observation was consistently combining both 'HR-positive/node-negative/>3cm' and 'HR-positive/node positive' BCs (N=127) that HER2 positive tumors showed worse survival (HR 3.7, 95%CI:1.2-10.8, p=0.015). Intriguingly, within this subgroup of HR-positive/node-negative/>3cm' and 'HR-positive/node positive' BCs, among HER2 positive tumors, while 5yr-DFS was 63.7% in patients who didn't receive trastuzumab, 100% were disease free in patients who were given trastuzumab.

Conclusions: Overall, nodal status was the most significant prognostic factor for pure mucinous breast cancer. In hormone receptor-positive, lymph node negative mucinous breast cancer with tumor of ≥3cm, HER2 positive BCs showed worse survival, suggesting a potential role of anti-HER2 strategy in this subgroup.

Citation Format: Gwark S-C, Lee JW, Lee SB, Sohn G, Kim J, Chung IY, Ko BS, Kim HJ, Son BH, Ahn SH. Clinical implication of HER2/neu status in hormone receptor positive pure mucinous breast cancer [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 P2-08-22.

Abstract P4-01-11: Genomic alterations of cell-free DNA in early breast cancer patients with recurrence

Cell-free DNA (cfDNA), as a non-invasive strategy, provides substantial benefit to overcome tumor heterogeneity. Surveillance of recurrence after standard treatment in early breast cancer (BC) using cfDNA, enables to detect minimal residual disease (MRD), also to identify genomic alterations driving recurrences. We aimed to assess the role of cfDNA in detecting MRD by investigating genomic alterations of 1)primary, recurred tumor and 2)cfDNA at time of recurrence using deep targeted sequencing. Fifty-four early BC patients were enrolled prospectively between 2014 and 2017 at time of recurrence. Median disease free interval was 28.5 months (rage 6.2-49.8). 62.7% (32/51) were hormone receptor (HR) positive (28 HRpos/HER2neg, 4 HRpos/HER2pos), 11.8% (6/51) were HRneg/HER2pos and 25.5% (13/51) were triple negative BCs. 59.3% (32/54) patients developed loco-regional recurrence (15 local recurrence only, 13 regional only, 4 with both) and distant metastasis was observed among 40.7% (22/54) patients. Cell-free DNA was extracted from 5cc blood at time of recurrence. Deep targeted sequencing was performed using customized NGS panel –encompassing 426 cancer-related target coding region, 242 fusion and amplification-related region- of cfDNA and FFPE(formalin fixed paraffin embedded) tumor samples archived from surgical resection or biopsy. Deep targeted sequencing data was successfully performed in 72.1% (31/43) plasma samples and sequencing yield was significantly lower when stored for more than 2yrs (46.2% vs 83.3%).

Mutations of cfDNA and tumor (primary, recurred) were analyzed. Mean sequencing depth of cfDNA and FFPE were x425.7 and x777.6 respectively. Median number of pathogenic mutations found in primary tumor, cfDNA and recurred tumor were 27(range 12-99), 25(range 8-85) and 9(range 0-23). Among mutations found in primary tumor, 27.4% were shared mutations (range 8.1%-72.7%) with recurred tumor and 26.1% were shared mutations (range 4.7%-69.2%) observed in cfDNA sample. Among mutations found in recurred tumor, 40.9% were observed in cfDNA (range 17.7-87.5%). In primary tumor, median number of mutations with allelic fraction (MAF)>10% were 12 (range 4-21) and at least one mutation was found in cfDNA at time of recurrence. Among mutations with MAF>10%, 59.4% and 69.1% were found in cfDNA and recurred tumor. Known oncogenic mutations of PIK3CA, TP53, GATA3, AKT1, ESR1, RELN, ERBB2, ERBB3, BRCA1 mutation were found. PIK3CA gene (p.H1047R) was found in two cases both in primary tumor and cfDNA at recurrence (MAF 11.4% vs 5.3% and 12.3% vs 15.4%) suggesting de novo driver mutation. One patient developed regional recurrence during adjuvant aromatase inhibitor with ESR1 V392I mutation in both cfDNA and recurred tumor (MAF 48.1 and 54.5%), while another patient's recurred tumor during aromatase inhibitor harbored ESR1 D538G mutation exclusively in recurred tumor with MAF <1%. Both patients had no ESR1 hotpot mutation in primary tumor.

Our data showed sequencing yield of 83.3% in plasma samples within 2yr. Pathogenic mutations in primary tumor, especially when MAF>10%, half of them was observed in cfDNA at time of recurrence. ESR1 mutation should be included in cfDNA surveillance for patients undergoing endocrine therapy even absent in primary tumor.

Citation Format: Kim J, Jo WK, Kim KY, Kim BJ, Lee SB, Lee HJ, Yu JH, Kim HJ, Chung IY, Ko BS, Kim S-B, Jung KH, Ahn JH, Chang S, Lee JW, Son BH, Ahn SH. Genomic alterations of cell-free DNA in early breast cancer patients with recurrence [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 P4-01-11.

Abstract P2-08-60: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Lee S, Ahn SH, Son BH, Lee JW, Chung IY, Ko BS, Kim HJ, Kim J, Shon G. Withdrawn [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 P2-08-60.

Comparison of anterior segment optical coherence tomography findings in acanthamoeba keratitis and herpetic epithelial keratitis

This study is to investigate the characteristic features of Acanthamoeba keratitis (AK) that differentiating it from herpetic epithelial keratitis (HEK) using anterior segment optical coherence tomography (AS-OCT). Medical records of three eyes of each AK and herpetic keratitis who had AS-OCT examination were reviewed in this study. Slit-lamp biomicroscopy and AS-OCT was performed on the initial visit and on every follow-up visits in all patients. In all three AK cases, reflective bands in the corneal stroma that correspond to the area of radial keratoneuritis were observed. The depth of the reflective bands varied in each case. After AK treatment, slit-lamp biomicroscopy confirmed that radial keratoneuritis had resolved and AS-OCT confirmed that reflective bands in the corneal stroma had also disappeared in all patients. Unlike the AS-OCT results found in AK, highly reflective HEK lesions were observed only in the subepithelial area, not in the stroma. AS-OCT seems to be helpful analyzing the specific depth of the lesion which enables to distinguish AK from HEK.

Lysophosphatidylserine receptor P2Y10: A G protein-coupled receptor that mediates eosinophil degranulation

BACKGROUND

P2Y10, along with GPR34 and GPR174, is a G protein-coupled receptor that is activated by an endogenous lipid mediator lysophosphatidylserine (LysoPS). Its expression pattern and its function are completely unknown. We have previously shown that P2Y10 is one of the highly up-regulated genes at the late differentiation stage during in vitro eosinophilopoiesis.

OBJECTIVE

We explored the expression and functions of P2Y10 in human cord blood (CB)-derived and peripheral blood (PB) eosinophils.

METHODS

Real-time PCR, FACS, Western blot, ELISA, and chemotaxis assays were performed to determine the expression and function of P2Y10.

RESULTS

As CB cells differentiated towards eosinophils, P2Y10 mRNA and protein were abundantly expressed. P2Y10 was the most highly expressed in the granulocytes from PB, to a lesser extent in monocytes, and least in lymphocytes. Further fractionation of granulocytes revealed that eosinophils express P2Y10 much more strongly than do neutrophils. PB eosinophils solely expressed P2Y10 among the three LysoPS receptors, while PB neutrophils expressed the three at comparable levels. LysoPS activated both CB and PB eosinophils to induce a robust ERK phosphorylation. Importantly, LysoPS was capable of triggering degranulation of ECP in PB eosinophils. This response was significantly reduced by pharmacological inhibitors of TNF-alpha-converting enzyme (TACE), epidermal growth factor receptor (EGFR), and ERK1/2, which were known to be required in P2Y10-mediated signalling pathways. However, LysoPS had no effect on chemotaxis, differentiation, or eosinophil survival.

CONCLUSIONS AND CLINICAL RELEVANCE

LysoPS provokes eosinophil degranulation through P2Y10. Therefore, P2Y10 is a potential therapeutic target to control eosinophil-associated diseases.

Abstract P1-07-29: Clinicopathologic characteristics and prognostic factors of pure mucinous breast cancer

Background: Mucinous carcinoma of the breast is a uncommon particular type of breast cancer and comprises approximately 4% of all invasive breast cancers. It is charactarized by abundant extracellular mucin production and present a more favorable prognosis than IDC-NOS. Pathologically, mucinous carcinoma is divided into two subtypes : pure and mixed. In this study, we reviewed the clinicopathologic characteristics and prognostic factors of pure mucinous carcinoma.

Methods: We reviewed the 23 years cumulative data of pure mucinous breast cancer patients from database of the Breast Cancer Center at ASAN medical center, Korea, between 1989-2011, retrospectively. Total 386 pure mucinous carcinoma cases were reviewed to analyze clinicopathologic characteristics and prognosis.

Result: Total of 386 patients with pure mucinous breast cancer were identified. Mean age was 46.7. 149 patients underwent modified radical mastectomy and 236 underwent breast-conserving therapy. The T-stage was T1 in 187 patients, T2 in 178 patients, T3 in 17 patient and T4 in 4 patients. Node negative was 325 and node positive was 61. Estrogen receptor was positive in 342 and negative in 29. Progesterone receptor was positive in 276 and negative in 95. HER-2 was positive in 47 and negative in 273. 152 patients received adjuvant chemotherapy and 240 patients received adjuvant radiotherapy. 351 patients received hormone therapy and among these patients, 231 patients were treated with Tamoxifen alone, 81 were Tamoxifen with ovarian function suppression, 37 were AI only and one patient was ovarian function suppression only. The 5 year disease free survival rate was 93.3%, 5 year cancer specific survival rate was 98.2% and 5 year overall survival rate was 96.6%. Univariate analysis showed that ER status, nodal status and Her2 status were appear to be prognostic factor of Disease free survival rate. Using Cox regression, result of multivariate analysis revealed that only nodal status is the most significant prognostic factor for survival rate.

Conclusions: Pure mucinous carcinoma of the breast is a rare subtype with a favorable prognosis. Nodal status rather than ER status, Her2 status are considered to be the most significant prognostic factor of pure mucinos breast cancer.

Citation Format: Gwark SC, Lee JW, Lee SB, Sohn G, Kim J, Chung IY, Kim HJ, Ko BS, Son BH, Ahn SH. Clinicopathologic characteristics and prognostic factors of pure mucinous breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-29.

Nontarget screening using passive air and water sampling with a level II fugacity model to identify unregulated environmental contaminants

It is thought that there are many unregulated anthropogenic chemicals in the environment. For risk assessment of chemicals, it is essential to estimate the predicted environmental concentrations. As an effort of identifying residual organic contaminants in air and water in Korea, nontarget screening using two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) was conducted at 10 sites using polyurethane foam passive air sampler and at 6 sites using polydimethyl siloxane (PDMS) passive water sampler in three different seasons in 2014. More than 600 chemical peaks were identified satisfying the identification criteria in air and water samples, respectively, providing a list for further investigation. Chemical substances with reported national emission rates in 2014 (n=149) were also screened for potential existence in the environment using a level II fugacity model. Most of chemical substances classified as not detectable were not identified with detection frequency greater than 20% by nontarget screening, indicating that a simple equilibrium model has a strong potential to be used to exclude chemicals that are not likely to remain in the environment after emissions from targeted monitoring.

Ascorbic acid concentrations in aqueous humor after systemic vitamin C supplementation in patients with cataract: pilot study

Background

To measure ascorbic acid concentration in aqueous humor of patients with cataract after oral or intravenous vitamin C supplementation.

Methods

Forty-two eyes of 42 patients with senile cataract who underwent uncomplicated cataract surgery were enrolled. Patients (n = 14 each) were administered oral vitamin C (2 g), intravenous vitamin C (20 g) or no treatment (control group) on the day before surgery. Samples of aqueous humor (0.1 cm³) were obtained by anterior chamber aspiration at the beginning of surgery and stored at −80 °C. Ascorbic acid concentration in aqueous humor was measured by high-pressure liquid chromatography.

Results

The mean age at surgery was 62.5 years, with no difference among the three groups. The mean ± standard deviation concentrations of ascorbic acid in aqueous humor in the control and oral and intravenous vitamin C groups were 1347 ± 331 μmol/L, 1859 ± 408 μmol/L and 2387 ± 445 μmol/L, respectively. Ascorbic acid concentration was significantly lower in the control than in the oral (P < 0.01) and intravenous (P < 0.001) vitamin C groups and was significantly higher in the intravenous than in the oral vitamin C group (P < 0.05).

Conclusions

Ascorbic acid concentration in aqueous humor is increased by systemic vitamin C supplementation, with intravenous administration being more effective than oral administration.

Abstract P6-09-38: Interaction between body mass index and hormone receptor status as a prognostic factor in node-positive breast cancer

Purpose: The aim of this study was to investigate the interaction between BMI at breast cancer diagnosis and the various factors including hormone-receptor, menopausal and nodal status, and to find a specific subgroup where BMI has an effect on breast cancer prognosis.

Methods: We retrospectively analyzed the data of 8,763 non-metastatic invasive breast cancer patients from the Asan Medical Center's research database. Overall survival (OS) and breast cancer-specific survival (BCSS) among BMI groups were compared using the Kaplan-Meier method and Cox proportional hazard model with interaction term.

Results: Only in node-positive breast cancer, there was a significant interaction between obesity (BMI ≥ 30.0 kg/m2) at diagnosis and positive hormone receptor which showed worse overall survival (OS) and breast cancer specific survival (BCSS) than normal weight patients (adjusted hazard ratio [HR] = 1.65, 95% confidence interval [CI] = 1.01 to 2.69 and HR = 1.90, 95% CI = 1.15 to 3.15, respectively). Underweight (BMI&lt;18.50 kg/m2) which interacted with negative hormone receptor status in node-positive breast cancer was associated with decreased OS (HR = 2.01, 95% CI = 1.02 to 3.98) and BCSS (HR = 2.15, 95% CI = 1.08 to 4.26). There was no significant interaction between BMI and hormone receptor status in node-negative setting and BMI did not interact with menopausal status in any population.

Conclusions: BMI interacts with hormone receptor status in node positive setting, thereby playing a role in the breast cancer prognosis.

Citation Format: Chung IY, Lee JW, Lee JS, Park YR, Lee Y, Lee SB, Kim HJ, Ko BS, Son BH, Ahn SH. Interaction between body mass index and hormone receptor status as a prognostic factor in node-positive breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P6-09-38.

Dual promoters of the major catalase (KatA) govern distinct survival strategies of Pseudomonas aeruginosa

KatA is the major catalase required for hydrogen peroxide (H₂O₂) resistance and acute virulence in Pseudomonas aeruginosa PA14, whose transcription is driven from the promoter (katAp1) located at 155 nucleotide (nt) upstream of the start codon. Here, we identified another promoter (katAp2), the +1 of which was mapped at the 51 nt upstream of the start codon, which was responsible for the basal transcription during the planktonic culture and down-regulated upon H₂O₂ treatment under the control by the master regulator of anaerobiosis, Anr. To dissect the roles of the dual promoters in conditions involving KatA, we created the promoter mutants for each -10 box (p1m, p2m, and p1p2m) and found that katAp1 is required for the function of KatA in the logarithmic growth phase during the planktonic culture as well as in acute virulence, whereas katAp2 is required for the function of KatA in the stationary phase as well as in the prolonged biofilm culture. This dismantling of the dual promoters of katA sheds light on the roles of KatA in stress resistance in both proliferative and growth-restrictive conditions and thus provides an insight into the regulatory impacts of the major catalase on the survival strategies of P. aeruginosa.

Quantitative analysis of temperature dependent acoustic trapping characteristics by using concentric annular type dual element ultrasonic transducer

This paper presents the temperature dependence of lateral acoustic trapping capability by probing the speed of sound in individual lipid droplets at a given temperature of water and measuring its corresponding displacement, a value for quantitatively evaluating a spring-like behavior of the acoustic trap with certain strength. A 20/40 MHz dual element LiNbO3 ultrasonic transducer is fabricated to simultaneously perform both transverse trapping and sound speed measurement for each droplet over a discrete temperature range from 20°C to 30°C. Time of flight method is employed for pulse tracking that determines the arrival time of an echo reflected back from either a trapped droplet or a mylar film. The estimated speeds of sound in water and droplets are 1484.8 m/s and 1431.6 m/s at 20°C, while 1506.0 m/s and 1400.6 m/s at 30°C, respectively. As the temperature rises, the sound speed in droplets decreases at an average rate of 3.1 m/s/°C, and the speed in water increases at 2.1 m/s/°C. The average displacement varies from 150.0 μm to 179.0 μm with an increasing rate of 2.9 μm/°C, and its standard deviation is obtained between 1.0 μm and 2.0 μm over the same temperature range. Reduced sound speed as a function of rising temperature results in increased displacement, indicating that the trapping strength is adjustable by regulating ambient temperature in water as well as by changing transducer excitation parameters. Therefore, the results suggest that the temperature dependence of this trapping technique can be exploited for developing a remote manipulation tool of micron-sized particles in a thermally fluctuating environment. It is also shown that any deviated trapping strength caused by thermal disturbance near the trap can be restored to its desired level by compensating either temperature difference or trapping system condition.

A case of phacolytic glaucoma with anterior lens capsule disruption identified by scanning electron microscopy

Background

Phacolytic glaucoma is induced by lens protein or macrophages that have leaked through a macroscopically intact anterior lens capsule. Here, we report a case of phacolytic glaucoma with anterior lens capsule disruptions visualized by scanning electron microscopy (SEM).

Case presentation

A 71-year-old man was referred to our institute for increased intraocular pressure (IOP) in the right eye. Slit-lamp biomicroscopic examination revealed corneal edema, the presence of inflammatory cells and iridescent crystalline in the anterior chamber, and a hypermature cataract in the right eye. Despite treatment with topical glaucoma medication (0.15% brimonidine, 1% brinzolamide/0.5% timolol, and 0.03% bimatoprost) and systemic mannitol, his IOP remained uncontrolled. Light microscopy was used to examine the aqueous humor obtained via anterior chamber paracentesis and the anterior lens capsule obtained via intracapsular cataract extraction (ICCE), which revealed that the anterior lens capsule was intact. However, SEM revealed full-thickness disruptions in the anterior lens.

Conclusion

This is the first reported case of phacolytic glaucoma with disruptions of the anterior lens capsule confirmed by SEM.

Efficacy of systemic vitamin C supplementation in reducing corneal opacity resulting from infectious keratitis

The objective of this study was to determine the effect of vitamin C supplementation on reducing the size of corneal opacity resulting from infectious keratitis.The study included 82 patients (82 affected eyes), admitted for infectious keratitis from January 2009 to August 2013, who were followed for more than 3 months. Patients were divided into control, oral vitamin C (3 g/d), and intravenous vitamin C (20 g/d) groups during hospitalization. Corneal opacity sizes were measured using anterior segment photographs and Image J program (version 1.27; National Institutes of Health, Jinju, South Korea) at admission, discharge, and final follow-up. The corneal opacity size used for analysis was the measured opacity size divided by the size of the whole cornea.The corneal opacity size decreased by 0.03 ± 0.10 in the oral vitamin C group, 0.07 ± 0.22 in the intravenous vitamin C group, and 0.02 ± 0.15 in the control group. Intravenous vitamin C reduced the corneal opacity size more than oral vitamin C (P = 0.043). Intravenous vitamin C produced greater reduction in corneal opacity size in younger patients (P = 0.015) and those with a hypopyon (P = 0.036).Systemic vitamin C supplementation reduced the size of corneal opacity resulting from infectious keratitis. Intravenous vitamin C was more beneficial than oral supplementation, especially in younger patients and those with hypopyon.

A phage protein that inhibits the bacterial ATPase required for type IV pilus assembly

Type IV pili (TFPs) are required for bacterial twitching motility and for phage infection in the opportunistic human pathogen Pseudomonas aeruginosa. Here we describe a phage-encoded protein, D3112 protein gp05 (hereafter referred to as Tip, representing twitching inhibitory protein), whose expression is necessary and sufficient to mediate the inhibition of twitching motility. Tip interacts with and blocks the activity of bacterial-encoded PilB, the TFP assembly/extension ATPase, at an internal 40-aa region unique to PilB. Tip expression results in the loss of surface piliation. Based on these observations and the fact that many P. aeruginosa phages require TFPs for infection, Tip-mediated twitching inhibition may represent a generalized strategy for superinfection exclusion. Moreover, because TFPs are required for full virulence, PilB may be an attractive target for the development of novel antiinfectives.

Superinfection exclusion reveals heteroimmunity between Pseudomonas aeruginosa temperate phages

Temperate siphophages (MP29, MP42, and MP48) were isolated from the culture supernatant of clinical Pseudomonas aeruginosa isolates. The complete nucleotide sequences and annotation of the phage genomes revealed the overall synteny to the known temperate P. aeruginosa phages such as MP22, D3112, and DMS3. Genome-level sequence analysis showed the conservation of both ends of the linear genome and the divergence at the previously identified dissimilarity regions (R1 to R9). Protein sequence alignment of the c repressor (ORF1) of each phage enabled us to divide the six phages into two groups: D3112 group (D3112, MP29, MP42, and MP48) and MP22 group (MP22 and DMS3). Superinfection exclusion was observed between the phages belonging to the same group, which was mediated by the specific interaction between the c repressor and the cognate operator. Based on these, we suggest that the temperate siphophages prevalent in the clinical strains of P. aeruginosa represent at least two distinct heteroimmunity groups.

Sutureless intrascleral pocket technique of transscleral fixation of intraocular lens in previous vitrectomized eyes

In this case series, we assessed a new technique, the intrascleral pocket procedure of transscleral fixation (TF) of the intraocular lens (IOL) in post-vitrectomized eyes. We performed the transscleral fixation of IOL in four aphakic patients who underwent pars plana vitrectomy. Two points 180° apart were marked at the limbus. A 2-mm-sized intrascleral pocket was created by lamellar dissection using a crescent blade without conjunctival dissection. A 2.8-mm clear corneal incision (CCI) was made using a keratome. Prolene sutures were exteriorized through the CCI pocket and a three-piece foldable acrylic IOL was injected via CCI and the ends of the haptics were exteriorized through the CCI. The prolene sutures for each haptic in the intrascleral pocket bed were then tied and knots were buried under scleral flaps. No patient had complaints such as conjunctival irritation, and visual acuity was almost identical to preoperative best-corrected visual acuity at day 1 postoperatively. IOLs were well placed without tilting or subluxation. They had no wound dehiscence or endophthalmitis postoperatively. The intrascleral pocket procedure of TF without the need for conjunctival dissection is a successful method for sulcus fixation in post-vitrectomized eyes predisposed to developing glaucoma.

The effect of 0.02% mitomycin C injection into the hair follicle with radiofrequency ablation in trichiasis patients

Purpose

To investigate the inhibitory effect of 0.02% mitomycin C on eyelash regrowth when injected to the eyelash hair follicle immediately after radiofrequency ablation.

Methods

We prospectively included 21 trichiasis patients from June 2011 to October 2012. Twenty eyes of 14 patients were treated with 0.02% mitomycin C to the hair follicle immediately after radiofrequency ablation in group 1, while radiofrequency ablation only was conducted in ten eyes of seven patients in group 2. Recurrences and complications were evaluated until six months after treatment.

Results

One hundred sixteen eyelashes of 20 eyes in group 1 underwent treatment, and 19 (16.4%) eyelashes recurred. Eighty-four eyelashes of ten eyes in group 2 underwent treatment, and 51 (60.7%) eyelashes recurred. No patients developed any complications related to mitomycin C.

Conclusions

Application of 0.02% mitomycin C in conjunction with radiofrequency ablation may help to improve the success rate of radiofrequency ablation treatment in trichiasis patients.

Common virulence factors for Pseudomonas tolaasii pathogenesis in Agaricus and Arabidopsis

Brown blotch of cultivatable mushrooms is a disease caused by the small peptide toxin (tolaasin) secreted by Pseudomonas tolaasii. Here we found that the wild type tolassin-producing P. tolaasii stain 6264 was capable of infection in Arabidopsis thaliana cotyledons, causing chlorotic symptoms and growth arrest as a result of bacterial proliferation. Seven virulence-attenuated mutants of P. tolaasii were isolated from the Agaricus bisporus screen using 2512 mariner-based transposon insertion mutants, and all of them displayed reduced virulence and bacterial proliferation in Arabidopsis infection as well. The transposon was inserted within the genes for tolassin biosynthesis and amino acid biosynthesis, and within an intergenic region between the genes of unknown function. The finding that some virulence factors are commonly required for both Agaricus and Arabidopsis infections suggests that Arabidopsis could be exploited to study the host-pathogen interaction involving P. tolaasii.

A novel forkhead box C1 gene mutation in a Korean family with Axenfeld-Rieger syndrome

PURPOSE

To report a case series of patients with novel forkhead box CI (FOXC1) mutations in a Korean family with Axenfeld-Rieger syndrome (ARS).

METHODS

Four members of the same family underwent complete ophthalmologic and systemic examinations and genetic analysis. Genomic DNA was isolated from peripheral blood leukocytes, and all coding exons with flanking intronic regions of the FOXC1 and pituitary homeobox 2 genes were amplified using PCR, and sequenced.

RESULTS

The patients were 40, 12, 11, and 10 years old (father, son, and two sisters, respectively). All four had uncontrolled intraocular pressure, glaucomatous visual field defect, retinal nerve fiber layer defect, iridocorneal adhesion on gonioscopy, hypoplasia and marked atrophy of the iris, flattening of the midface, and broad flat noses. A diagnosis of ARS was made based on characteristic ocular and systemic traits. A novel FOXC mutation, c.317delA, was identified in all affected members of the family with ARS.

CONCLUSIONS

We found a novel c.317delA mutation in FOXC1 in a Korean family with ARS. We suggest that this FOXC1 mutation causes typical ARS, and that our results may be useful for better understanding of the spectrum of FOXC1 mutations and the role of FOXC1 in the development and progression of ARS.

A Case of Invasive Aspergillosis Presenting as Acute Angle Closure Glaucoma

Purpose: To report a case of invasive aspergillosis presenting as acute angle closure glaucoma. Case: A 72-year-old male patient visited our clinic with decreased visual acuity and ocular pain on the right eye lasting for 3 d. His intraocular pressure was 42 mmHg in the right eye and 18 mmHg in the left eye. And, there was about 2 mm of exophthalmos, slight ptosis with decreased motility in all directions, conjunctival injection, moderate mydriasis with a relative afferent pupillary defect, and angle closure in the right eye. Orbital computed tomography and magenetic resonance imaging showed isotense mass involving right orbit and ethmoid sinus. Based on the biopsy, invasive aspergillosis was definitely diagnosed. Despite perfoming peripheral laser iridotomy and administrating antifungal agent and antiglaucoma medication, the patient was blinded in his right eye. During the follow-up period, visual acuity in the left eye suddenly decreased due to the invasive aspergillosis in the left paranasal sinus and optic nerve, and eventually the patient lost his left vision as well. Conclusion: This report is regarding a case of an invasive aspergillosis resulting in blindness in both eyes with the clinical manifestations of acute angle closure caused by invasive aspergillosis.

Microfluidic droplet sorting with a high frequency ultrasound beam

This paper presents experimental results demonstrating the feasibility of high frequency ultrasonic sensing and sorting for screening single oleic acid (lipid or oil) droplets under continuous flow in a microfluidic channel. In these experiments, hydrodynamically focused lipid droplets of two different diameters (50 μm and 100 μm) are centered along the middle of the channel, which is filled with deionized (DI) water. A 30 MHz lithium niobate (LiNbO(3)) transducer, placed outside the channel, first transmits short sensing pulses to non-invasively determine the acoustic scattering properties of the individual droplets passing through the beam's focus. Integrated backscatter (IB) coefficients, utilized as a sorting criterion, are measured by analyzing the received echo signals from each droplet. When the IB values corresponding to 100 μm droplets are obtained, a custom-built LabVIEW panel commands the transducer to emit sinusoidal burst signals to commence the sorting operation. The number of droplets tested for the sorting is 139 for 50 μm droplets and 95 for 100 μm droplets. The sensing efficiencies are estimated to be 98.6% and 99.0%, respectively. The sorting is carried out by applying acoustic radiation forces to 100 μm droplets to direct them towards the upper sheath flow, thus separating them from the centered droplet flow. The sorting efficiencies are 99.3% for 50 μm droplets and 85.3% for 100 μm droplets. The results suggest that this proposed technique has the potential to be further developed into a cost-effective and efficient cell/microparticle sorting instrument.

Simulation study on discrete charge effects of SiNW biosensors according to bound target position using a 3D TCAD simulator

We introduce a simulation method for the biosensor environment which treats the semiconductor and the electrolyte region together, using the well-established semiconductor 3D TCAD simulator tool. Using this simulation method, we conduct electrostatic simulations of SiNW biosensors with a more realistic target charge model where the target is described as a charged cube, randomly located across the nanowire surface, and analyze the Coulomb effect on the SiNW FET according to the position and distribution of the target charges. The simulation results show the considerable variation in the SiNW current according to the bound target positions, and also the dependence of conductance modulation on the polarity of target charges. This simulation method and the results can be utilized for analysis of the properties and behavior of the biosensor device, such as the sensing limit or the sensing resolution.

Genetic effect of single-nucleotide polymorphisms in the PPARGC1B gene on airway hyperreactivity in asthmatic patients

BACKGROUND

Peroxisome proliferator-activated receptor gamma coactivator 1 beta (PPARGC1B) is a co-activator for intracellular receptors such as the estrogen receptor, PPAR, and glucocorticoid receptor, which are involved in asthma development.

OBJECTIVES

Genetic association of single-nucleotide polymorphisms (SNPs) in the PPARGC1B gene with the risk of asthma and airway hyperreactivity (AHR) was investigated, as well as the functional effects of these SNPs on PPARGC1B gene and protein expression.

METHODS

Direct sequencing of DNA from 24 Korean was performed to identify PPARGC1B SNPs. Genotyping was done in 264 controls and 949 asthmatics using single-base extension methods. PPARGC1B mRNA levels were measured using real-time PCR methodology. Luciferase and electrophoretic mobility shift assays (EMSA) were performed to functionally analyse PPARGC1B SNPs on promoter.

RESULTS

Eighteen SNPs and one insertion/deletion polymorphism were identified, and seven SNPs were genotyped. No significant difference existed in the distribution of SNPs and haplotypes between the asthmatics and controls. However, the allele frequency of -427C>T and +102525G>A;R265Q showed a significant association with log-transformed PC(20) methacholine values in the asthmatics (P=0.005-0.0004). Real-time PCR demonstrated higher PPARGC1B mRNA levels in asthmatics having -427CC allele than in those having -427TT or CT alleles (P=0.048). The ratio of the mRNA expression for each PPARGC1B exon4-mRNA compared with the wild type was similar in peripheral blood mononuclear cells carrying the +102525G>A allele. Luciferase reporter assays revealed that -427C allele caused higher promoter activity than -427T allele. EMSA demonstrated that -427C allele exhibited stronger binding activity to a nuclear protein in 293T cells than did the -427T allele.

CONCLUSIONS AND CLINICAL RELEVANCE

Polymorphisms of -427C>T on the promoter and those of +102525G>A on exon 5 of the PPARGC1B gene may affect the development of AHR through the modulation of PPARGC1B gene products. The PPARGC1B genotypes may serve as genetic markers for AHR.

Treatment with triamcinolone acetonide prevents decreased retinal levels of decorin in a rat model of oxygen-induced retinopathy

PURPOSE

To investigate the effect of triamcinolone acetonide (TA) on retinal expression of decorin in a rat model of oxygen-induced retinopathy (OIR).

MATERIALS AND METHODS

OIR was stimulated by exposing Sprague-Dawley (SD) rats to hyperoxia (80 +/- 1.3% O2) from postnatal day (P) 2 to P14 and then returning them to normoxia (room air, 21 +/- 1.5% O2). Control rats were maintained in normoxia. At P15, TA (40 mg/ml) was injected into the right vitreous of OIR rats and saline into the left vitreous of control rats. All rats were sacrificed at P18. RT-PCR, western blot and immunohistochemistry, TUNEL assay were performed to detect the effects of TA on molecular and morphological changes in retinal decorin levels in P18 OIR rats.

RESULTS

In P18 OIR rats, mRNA and protein of retinal levels and immunoreactivity of retinal decorin were significantly less (p-value = 0.0000000012, 0.0007, 0.000003; n = 5; respectively) than in control rats. In addition, neuronal cell death was increased in P18 OIR rats (p-value = 0.0028; n = 5) relative to controls. However, treatment with TA prevented the decrease of mRNA, protein levels, and immunoreactivity in retinal decorin in P18 OIR rats (p-value = 0.00023, 0.003, 0.000079; n = 5, respectively), and restored neuronal cell death in P18 OIR rats (p-value = 0.0022, n = 5).

CONCLUSION

Our results suggest that decorin is involved in hypoxic retinal damage and that TA protects retinal neurons damaged by relative hypoxia from decreased decorin levels.

Biosensor system-on-a-chip including CMOS-based signal processing circuits and 64 carbon nanotube-based sensors for the detection of a neurotransmitter

We developed a carbon nanotube (CNT)-based biosensor system-on-a-chip (SoC) for the detection of a neurotransmitter. Here, 64 CNT-based sensors were integrated with silicon-based signal processing circuits in a single chip, which was made possible by combining several technological breakthroughs such as efficient signal processing, uniform CNT networks, and biocompatible functionalization of CNT-based sensors. The chip was utilized to detect glutamate, a neurotransmitter, where ammonia, a byproduct of the enzymatic reaction of glutamate and glutamate oxidase on CNT-based sensors, modulated the conductance signals to the CNT-based sensors. This is a major technological advancement in the integration of CNT-based sensors with microelectronics, and this chip can be readily integrated with larger scale lab-on-a-chip (LoC) systems for various applications such as LoC systems for neural networks.

Bilateral endophthalmitis as the initial presentation of bacterial meningitis

To report a case of bilateral endophthalmitis as the initial presentation of bacterial meningitis in a young, immunocompetent Korean patient. A 35-year-old female with a one day history of bilateral swollen eyes, visual disturbance, headache, petechial skin rash, and nausea visited our clinic. She was diagnosed as having endogenous endophthalmitis associated with bacterial meningitis. Intravenous broad spectrum antibiotic therapy was initiated with cefotaxime 3 g and ubacillin 3 g, four times daily. Intravitreal antibiotic (vancomycin 1 mg/0.1 mL and ceftazidime 2 mg/0.1 mL) injections were performed in both eyes. Two weeks post presentation, the best corrected visual acuity in both eyes improved to 0.7, and inflammation of the anterior chamber and vitreous cavity was decreased. We recommend that when endogenous endophthalmitis is suspected along with meningitis, or if it is known to be present, intravitreal and intravenous antibiotics should be promptly administered to preserve vision.

Association of angiotensin I-converting enzyme gene polymorphisms with aspirin intolerance in asthmatics

BACKGROUND

Aspirin-intolerant asthma (AIA) refers to the development of bronchoconstriction in asthmatic individuals following the ingestion of aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs). Angiotensin I-converting enzyme (ACE), a membrane-bound peptidase present in the lung, plays a pivotal role in the metabolism of the endogenous peptides involved in the pathogenesis of asthma.

METHODS

We screened a Korean asthma cohort (581 asthmatics including 81 aspirin-intolerant asthmatics and 231 aspirin-tolerant asthmatics, and 181 normal controls) for four single nucleotide polymorphisms (SNPs; -262 A>T and -115 T>C in the 5'-flanking region and +5467 T>C [Pro450Pro] and+11860 A>G [Thr776Thr] in the coding region) and one ins/del (+21288 CT) in the ACE gene.

RESULTS

None of the SNPs or haplotypes showed any association with the development of asthma, but they were significantly associated with the risk of AIA. Logistic regression indicated that the frequency of the rare alleles of -262 A>T and -115 T>C was higher in subjects with AIA than in subjects with aspirin-tolerant asthma (ATA) (P=0.003-0.01, P( corr)=0.015-0.05). Subjects homozygous for the rare alleles of -262 A>T and -115 T>C showed a greater decline in forced expiratory volume in 1 s (FEV(1)) after aspirin provocation than those homozygous for the common alleles (P<0.05). A luciferase reporter assay indicated that ACE promoters containing the rare -262 A>T allele possessed lower activity than did those containing the common allele (P=0.009). In addition, ACE promoters bearing the rare -115 T>C allele had no luciferase activity. DNA-protein binding assays revealed a band containing the ACE promoter region (including -262 A) and a protein complex.

CONCLUSION

The -262 A>T polymorphism in the promoter of the ACE gene is associated with AIA, and the rare allele of -262 A>T may confer aspirin hypersensitivity via the down-regulation of ACE expression.

Effect of PEL exopolysaccharide on the wspF mutant phenotypes in Pseudomonas aeruginosa PA14

Pseudomonas aeruginosa is an opportunistic human pathogen that produces and secretes exopolysaccharides (EPS), in which cells are embedded to form a highly organized community structure called biofilm. Here, we characterized the role of cyclic diguanylate (c-di-GMP) and EPS (PEL) overproduction in the wspF mutant phenotypes of P. aeruginosa PA14 (wrinkly appearance, hyperadherence, impaired motilities, and reduced virulence in acute infections). We confirmed that the elevated c-di-GMP level plays a key role in all the wspF mutant phenotypes listed above, as assessed by ectopic expression of a c-di-GMP-degrading phophodiesterase (PvrR) in the wspF mutant. In contrast, PEL EPS, which is overproduced in the wspF mutant, was necessary for wrinkly appearance and hyperadherence, but not for the impaired flagellar motilities and the attenuated virulence of the wspF mutant. These results suggest that cdi- GMP affects flagellar motility and virulence, independently of EPS production and surface adherence of this bacterium.