Comparative Activities of Novel Therapeutic Agents against Molecularly Characterized Clinical Carbapenem-Resistant Enterobacterales Isolates

Limited treatment options exist for the treatment of carbapenem-resistant Enterobacterales (CRE) bacteria. Fortunately, there are several recently approved antibiotics indicated for CRE infections. Here, we examine the in vitro activity of various novel agents (eravacycline, plazomicin, ceftazidime-avibactam, imipenem-relebactam, and meropenem-vaborbactam) and comparators (tigecycline, amikacin, levofloxacin, fosfomycin, polymyxin B) against 365 well-characterized CRE clinical isolates with various genotypes. Nonduplicate isolates collected from the largest public health hospital in Singapore between 2007 and 2020 were subjected to antimicrobial susceptibility testing (broth microdilution or antibiotic gradient test strips). Susceptibilities were defined using Clinical and Laboratory Standards Institute (CLSI) or Food and Drug Administration (FDA) interpretative criteria. Sequence types and resistance mechanisms were characterized using short-read whole-genome sequencing. Overall, tigecycline and plazomicin exhibited the highest susceptibility rates (89.6% and 80.8%, respectively). However, the tigecycline susceptibility breakpoint utilized here may be outdated in view of prevailing pharmacokinetic-pharmacodynamic (PK/PD) data. Susceptibility varied by carbapenemase genotype; the β-lactam/β-lactamase inhibitor combinations were equally active (92.3 to 99.2% susceptible) against KPC producers, but only ceftazidime-avibactam retained high susceptibility (98.7%) against OXA-48-like producers. Against metallo-β-lactamase producers, only plazomicin exhibited moderate activity (77.0% susceptible). Aminoglycoside activity was also influenced by carbapenemase genotypes. This work provides an insight into the comparative activity and presumptive utility of novel agents in this geographic region. IMPORTANCE This study determined the susceptibilities of carbapenem-resistant Enterobacterales isolates to various novel antimicrobial agents (ceftazidime-avibactam, imipenem-relebactam, meropenem-vaborbactam, eravacycline, and plazomicin). Whole-genome sequencing was performed for all strains. Our study findings provide insights into the comparative activities of novel agents in this geographic region. Plazomicin and ceftazidime-avibactam exhibited the lowest nonsusceptibility rates and may be considered promising agents in the management of carbapenem-resistant Enterobacterales infections. We note also that antibiotic activity is influenced by genotypes and that understanding the geographic region's molecular epidemiology could aid in the definition of the presumptive utility of novel agents and contribute to antibiotic decision-making.

Handheld ultrasound-guided cannulation of difficult hemodialysis arteriovenous access: A randomized controlled trial

INTRODUCTION

Cannulation of complex arteriovenous fistula (AVF) or graft (AVG) frequently poses challenges to renal nursing practice. Ultrasound (US) guidance on visualizing central and peripheral venous access has been widely adopted in nephrology, reducing vascular intervention complications. Renal nurses could acquire this point-of-care technique to increase the successful cannulation rate while facilitating confidence build-up during practice. We aim to evaluate the use of handheld US on difficult AVF/AVG cannulation in a hospital-based dialysis unit.

METHODS

We conducted a single-center randomized controlled trial from January 2021 to January 2022. Ten renal nurses were trained by an interventional nephrologist before patient recruitment and had completed a pre- and posttraining questionnaire on their confidence level. Fifty hemodialysis patients with complex AVF were randomized to US-guided or conventional cannulation. The total time spent on cannulation and patients' pain scores were also collected.

FINDINGS

Renal nurses increased their confidence level after training (pretraining score 26.6 ± 6.9 vs. posttraining score 36.4 ± 3.0; p = 0.014). There was a higher success rate (only one cannulation attempt required) for US-guided (96%) versus conventional (72.0%) cannulation (p = 0.049). US-guided cannulation had a lower pain score than the conventional method (1.48 ± 0.73 vs. 2.13 ± 0.95, p = 0.012). The pre-cannulation assessment time and time spent on cannulation were comparable between the two groups.

DISCUSSION

Our study showed that US-guided cannulation increased renal nurses' confidence level in difficult cannulation and improved success rate. Larger scale studies are required to further assess the applications of handheld US in AVF cannulation, particularly in different clinical settings (e.g., chronic dialysis centers).

Genomic Surveillance of Carbapenem-Resistant Klebsiella pneumoniae from a Major Public Health Hospital in Singapore

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a global public health threat. In this study, we employed whole-genome sequencing (WGS) to determine the genomic epidemiology of a longitudinal collection of clinical CRKP isolates recovered from a large public acute care hospital in Singapore. Phylogenetic analyses, a characterization of resistance and virulence determinants, and plasmid profiling were performed for 575 unique CRKP isolates collected between 2009 and 2020. The phylogenetic analyses identified the presence of global high-risk clones among the CRKP population (clonal group [CG] 14/15, CG17/20, CG147, CG258, and sequence type [ST] 231), and these clones constituted 50% of the isolates. Carbapenemase production was common (n = 497, 86.4%), and KPC was the predominant carbapenemase (n = 235, 40.9%), followed by OXA-48-like (n = 128, 22.3%) and NDM (n = 93, 16.2%). Hypervirulence was detected in 59 (10.3%) isolates and was most common in the ST231 carbapenemase-producing isolates (21/59, 35.6%). Carbapenemase genes were associated with diverse plasmid replicons; however, there was an association of blaOXA-181/232 with ColKP3 plasmids. This study presents the complex and diverse epidemiology of the CRKP strains circulating in Singapore. Our study highlights the utility of WGS-based genomic surveillance in tracking the population dynamics of CRKP. IMPORTANCE In this study, we characterized carbapenem-resistant Klebsiella pneumoniae clinical isolates collected over a 12-year period in the largest public acute-care hospital in Singapore using whole-genome sequencing. The results of this study demonstrate significant genomic diversity with the presence of well-known epidemic, multidrug-resistant clones amid a diverse pool of nonepidemic lineages. Genomic surveillance involving comprehensive resistance, virulence, and plasmid gene content profiling provided critical information for antimicrobial resistance monitoring and highlighted future surveillance priorities, such as the emergence of ST231 K. pneumoniae strains bearing multidrug resistance, virulence elements, and the potential plasmid-mediated transmission of the blaOXA-48-like gene. The findings here also reinforce the necessity of unique infection control and prevention strategies that take the genomic diversity of local circulating strains into consideration.

Spatial-temporal lipidomics profile of acute myocardial injury

Background

Lipidome disturbance has long been recognized to occur after myocardial infarction (MI). Accumulation of excessive fatty acids induces production of reactive oxygen species and consequently deteriorates cardiac injury in MI. However, the spatial and temporal lipid profile in the heart following ischemic injury remains unknown.

Purpose

We aim to uncover the temporal-spatial lipidome profile of the heart following ischemia reperfusion (I/R) injury and identify circulating lipids released from injured myocardium that are potentially useful for diagnosis of ischemic heart disease.

Methods

C57/BL6 mice were subjected to 30 min myocardial ischemia followed by removal of the ligature to establish reperfusion injury. Porcine I/R injury was induced by 105 min myocardial ischemia followed by reperfusion. Human plasma was obtained from 143 post-MI patients. Myocardial lipid profiles were generated by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry imaging (MALDI-MSI) in different regions (infarct, remote and peri-infarct) at different time points. Moreover, the lipids in the heart and plasma were analysed by LC-MS/MS.

Results

We observed a drastic alteration in the lipidome with distinct spatial-temporal features in the injured heart by both MALDI-MSI and LC-MS/MS. In the infarct heart tissue, as revealed by LC-MS/MS, we observed an elevation of glycerolipids that peaked at 3 hours after I/R, and a sustained elevation of phospholipids and sphingolipids up to 3 days. Similar alternations in lipid profile was observed but much weaker in the remote and peri-infarct heart tissue compared to the infarct tissue. Among those lipids, PC 32:0 detected by MALDI-MSI highly overlapped CD68 staining at a single-cell level, showing a strong correlation of PC 32:0 with macrophage infiltration in mouse hearts (R2=0.93, p<0.0001). A similar increase of PC 32:0 in the infarct area was also observed in porcine hearts following I/R injury. Surprisingly, plasma levels of PC 32:0 in the mice decreased after I/R injury. In humans, plasma levels of PC 32:0 in post-MI patients were lower than that in healthy individuals (p=0.03). Further analysis demonstrated that plasma levels of PC 32:0 determined within 72 hours after percutaneous coronary intervention were negatively correlated with the 6-month post-MI cardiac ejection fraction in patients (R2=0.08, p<0.001).

Conclusions

A temporal-spatial lipidome profile was established in heart injury by synergizing LC-MS/MS and mass spectrometry imaging. PC 32:0 levels are positively correlated with myocardial macrophage infiltration but negatively correlated with cardiac function in cardiac I/R injury. Our findings indicate that PC 32:0 is a potential biomarker for cardiac injury and the inflammatory status in the injured heart.

Funding Acknowledgement

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Singapore Ministry of Health's National Medical Research Council

Prevalence and burden of skin diseases among the elderly in Singapore: A 15-year clinical cohort study

BACKGROUND

Populations around the world are rapidly ageing. The profile of skin diseases in the elderly is likely to present unique demands on the healthcare system.

OBJECTIVES

To provide current data on the burden of skin diseases in Singaporean patients and identify differences in the pattern of skin diseases between elderly patients and the rest of the population.

METHODS

This was a retrospective cohort study of 858,117 patients who attended the National Skin Centre between 2004 to 2018. Prevalence was calculated by grouping International Classification of Diseases codes into different categories of skin conditions based on Global Burden of Disease and American Academy of Dermatology classifications. Years lost to disability (YLD) and disability-adjusted life years (DALY) were calculated to report the morbidity and mortality of skin diseases. Differences of each skin condition between age groups were compared.

RESULTS

The three most prevalent dermatoses across all age groups were dermatitis (33.3%), acne vulgaris (8.3%) and viral skin diseases (7.5%). The top three most common skin conditions among the elderly were dermatitis (37.7%), viral skin diseases (6.2%), and fungal skin diseases (4.3%). Decubitus ulcers, keratinocyte carcinomas and scabies represented a significant proportion of YLD per 100,000 in the elderly (p <0.001). Malignant melanomas, keratinocyte carcinomas, cellulitis, pyoderma, and decubitus ulcers contributed to high DALY in patients aged 70 - 80 years old.

CONCLUSION

Aligning health systems with specific healthcare needs will reduce the disproportionately high burden of skin disease observed in the elderly.

The aquaculture supply chain in the time of covid-19 pandemic: Vulnerability, resilience, solutions and priorities at the global scale

The COVID-19 global pandemic has had severe, unpredictable and synchronous impacts on all levels of perishable food supply chains (PFSC), across multiple sectors and spatial scales. Aquaculture plays a vital and rapidly expanding role in food security, in some cases overtaking wild caught fisheries in the production of high-quality animal protein in this PFSC. We performed a rapid global assessment to evaluate the effects of the COVID-19 pandemic and related emerging control measures on the aquaculture supply chain. Socio-economic effects of the pandemic were analysed by surveying the perceptions of stakeholders, who were asked to describe potential supply-side disruption, vulnerabilities and resilience patterns along the production pipeline with four main supply chain components: a) hatchery, b) production/processing, c) distribution/logistics and d) market. We also assessed different farming strategies, comparing land- vs. sea-based systems; extensive vs. intensive methods; and with and without integrated multi-trophic aquaculture, IMTA. In addition to evaluating levels and sources of economic distress, interviewees were asked to identify mitigation solutions adopted at local / internal (i.e., farm-site) scales, and to express their preference on national / external scale mitigation measures among a set of a priori options. Survey responses identified the potential causes of disruption, ripple effects, sources of food insecurity, and socio-economic conflicts. They also pointed to various levels of mitigation strategies. The collated evidence represents a first baseline useful to address future disaster-driven responses, to reinforce the resilience of the sector and to facilitate the design reconstruction plans and mitigation measures, such as financial aid strategies.

In vitro Bactericidal Activities of Combination Antibiotic Therapies Against Carbapenem-Resistant Klebsiella pneumoniae With Different Carbapenemases and Sequence Types

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is becoming increasingly problematic due to the limited effectiveness of new antimicrobials or other factors such as treatment cost. Thus, combination therapy remains a suitable treatment option. We aimed to evaluate the in vitro bactericidal activity of various antibiotic combinations against CRKP with different carbapenemase genotypes and sequence types (STs). Thirty-seven CRKP with various STs and carbapenemases were exposed to 11 antibiotic combinations (polymyxin B or tigecycline in combination with β-lactams including aztreonam, cefepime, piperacillin/tazobactam, doripenem, meropenem, and polymyxin B with tigecycline) in static time-kill studies (TKS) using clinically achievable concentrations. Out of the 407 isolate-combination pairs, only 146 (35.8%) were bactericidal (≥3 log₁₀CFU/mL decrease from initial inoculum). Polymyxin B in combination with doripenem, meropenem, or cefepime was the most active, each demonstrating bactericidal activity in 27, 24, and 24 out of 37 isolates, respectively. Tigecycline in combination with β-lactams was rarely bactericidal. Aside from the lower frequency of bactericidal activity in the dual-carbapenemase producers, there was no apparent difference in combination activity among the strains with other carbapenemase types. In addition, bactericidal combinations were varied even in strains with similar STs, carbapenemases, and other genomic characteristics. Our findings demonstrate that the bactericidal activity of antibiotic combinations is highly strain-specific likely owing to the complex interplay of carbapenem-resistance mechanisms, i.e., carbapenemase genotype alone cannot predict in vitro bactericidal activity. The availability of WGS information can help rationalize the activity of certain combinations. Further studies should explore the use of genomic markers with phenotypic information to predict combination activity.

Genomic characterization of carbapenem-non-susceptible Pseudomonas aeruginosa in Singapore

Pseudomonas aeruginosa is a clinically important pathogen implicated in many hospital-acquired infections. Its propensity to acquire broad-spectrum resistance has earned the organism its status as a severe public health threat requiring urgent control measures. While whole-genome sequencing-based genomic surveillance provides a means to track antimicrobial resistance, its use in molecular epidemiological surveys of P. aeruginosa remains limited, especially in the Southeast Asian region. We sequenced the whole genomes of 222 carbapenem-non-susceptible P. aeruginosa (CNPA) isolates collected in 2006–2020 at the largest public acute care hospital in Singapore. Antimicrobial susceptibilities were determined using broth microdilution. Clonal relatedness, multi-locus sequence types, and antimicrobial resistance determinants (acquired and chromosomal) were determined. In this study, CNPA exhibited broad-spectrum resistance (87.8% multi-drug resistance), retaining susceptibility only to polymyxin B (95.0%) and amikacin (55.0%). Carbapenemases were detected in 51.4% of the isolates, where IMP and NDM metallo-β-lactamases were the most frequent. Carbapenem resistance was also likely associated with OprD alterations or efflux mechanisms (ArmZ/NalD mutations), which occurred in strains with or without carbapenemases. The population of CNPA in the hospital was diverse; the 222 isolates grouped into 68 sequence types (ST), which included various high-risk clones. We detected an emerging clone, the NDM-1-producing ST308, in addition to the global high-risk ST235 clone which was the predominant clone in our population. Our results thus provide a “snapshot” of the circulating lineages of CNPA locally and the prevailing genetic mechanisms contributing to carbapenem resistance. This database also serves as the baseline for future prospective surveillance studies.

P–150 Does trophectoderm biopsy performed on different blastocyst stages affect the clinical outcome?

Study question

The objective of this study is to evaluate the effect of trophectoderm (TE) biopsy on different blastocyst stages and its clinical outcome.

Summary answer

Our results showed that TE biopsy significantly reduced the clinical outcome of fully hatched blastocyst. What is known already: TE biopsy is a method widely practiced to harvest cells to determine the chromosomal constitution of a blastocyst, ensuring higher implantation and healthy pregnancies. The effect on clinical outcome after transferring blastocysts biopsied at different blastocysts stages has not been extensively studied.

Study design, size, duration

This retrospective study was conducted from January 2017 until July 2019 at Alpha IVF & Women’s Specialists. Following laser assisted hatching on day 3, TE biopsy was performed on unhatched, hatching and fully hatched day–5 blastocysts. A total of 1,020 single euploid blastocysts transfer (SBT) were performed. The average maternal age was 31.7. Implantation rates (IR) were evaluated for all stages of hatching (Unhatched: BG3 & 4; hatching: BG5; fully hatched: BG6).

Participants/materials, setting, methods

Laser assisted hatching (Hamilton Thorne Bioscience, USA) was performed on day–3 and subsequently cultured to blastocyst-stage. Different hatching stages were observed using embryoscope time-lapse system (Vitrolife, Sweden) and were recorded. Day–5 blastocysts with at least BG3BB grade (Gardner’s System) were selected for TE biopsy and the biopsied cells were sent for preimplantation genetic testing for aneuploidy (PGT-A) using Next-Generation Sequencing (Life Technologies, USA). All blastocysts were vitrified and warmed using the Cryotec Method (Cryotech, Japan). Main results and the role of chance: All 1,020 blastocysts survived post-warmed (post-warm survival rate= 100%) and were transferred in frozen transfer cycles. TE biopsy performed on unhatched blastocysts showed a comparable IR to hatching blastocysts (60.0% [15/25] and 65.2% [627/961]). While fully hatched blastocysts (44.12% [15/34]) show a significantly lower IR when compared to hatching blastocysts (65.2% [627/961]), no significant difference was seen when comparing unhatched blastocysts to fully hatched blastocysts (60.0% [15/25] and 44.12% [15/34]; p = 0.2949).

Limitations, reasons for caution

The sample size was comparatively smaller in the unhatched and fully hatched group than the hatching group. Further studies with a larger sample size is recommended to ascertain the clinical outcome. Since this is a retrospective study and biopsy was done by different embryologists, the biopsy technique was not controlled. Wider implications of the findings: To achieve higher clinical pregnancy, it is recommended to perform TE biopsy before the blastocysts is fully hatched.

Trial registration number

Not applicable

In vitro antiviral activity of medicinal mushroom Ganoderma neo-japonicum Imazeki against enteroviruses that caused hand, foot and mouth disease

Hand, foot and mouth disease (HFMD) is a highly contagious viral disease that predominantly affects children younger than 5 years old. HFMD is primarily caused by enterovirus A71 (EVA71) and coxsackievirus A16 (CV-A16). However, coxsackievirus A10 (CV-A10) and coxsackievirus A6 (CV-A6) are being increasingly reported as the predominant causative of HFMD outbreaks worldwide since the past decade. To date, there are still no licensed multivalent vaccines or antiviral drugs targeting enteroviruses that cause HFMD, despite HFMD outbreaks are still being frequently reported, especially in Asia-Pacific countries. The high rate of transmission, morbidity and potential neurological complications of HFMD is indeed making the development of broad-spectrum antiviral drugs/agents against these enteroviruses a compelling need. In this study, we have investigated the in vitro antiviral effect of 4 Ganoderma neo-japonicum Imazeki (GNJI) crude extracts (S1-S4) against EV-A71, CV-A16, CV-A10 and CV-A6. GNJI is a medicinal mushroom that can be found growing saprophytically on decaying bamboo clumps in Malaysian forests. The antiviral effects of this medicinal mushroom were determined using cytopathic inhibition and virus titration assays. The S2 (1.25 mg/ml) hot aqueous extract demonstrated the highest broad-spectrum antiviral activity against all tested enteroviruses in human primary oral fibroblast cells. Replication of EV-A71, CV-A16 and CVA10 were effectively inhibited at 2 hours post-infection (hpi) to 72 hpi, except for CV-A6 which was only at 2 hpi. S2 also has virucidal activity against EV-A71. Polysaccharides isolated and purified from crude hot aqueous extract demonstrated similar antiviral activity as S2, suggesting that polysaccharides could be one of the active compounds responsible for the antiviral activity shown by S2. To our knowledge, this study demonstrates for the first time the ability of GNJI to inhibit enterovirus infection and replication. Thus, GNJI is potential to be further developed as an antiviral agent against enteroviruses that caused HFMD.

Results from the Survey of Antibiotic Resistance (SOAR) 2016-18 in Vietnam, Cambodia, Singapore and the Philippines: data based on CLSI, EUCAST (dose-specific) and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints

OBJECTIVES

To determine antibiotic susceptibility of Streptococcus pneumoniae and Haemophilus influenzae isolates collected from community-acquired respiratory tract infections (CA-RTIs) in 2016-18 in four Asian countries.

METHODS

MICs were determined by CLSI broth microdilution and susceptibility was assessed using CLSI, EUCAST (dose-specific) and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints.

RESULTS

In total, 260 S. pneumoniae and 258 H. influenzae isolates were tested. Pneumococci from Vietnam (n = 161) were the least susceptible, with rates of susceptibility >90% for fluoroquinolones by CLSI breakpoints, ∼60% for amoxicillin, amoxicillin/clavulanic acid and ceftriaxone but <14% for most other agents. Pneumococcal isolates from Cambodia (n = 48) and Singapore (n = 34) showed susceptibilities ranging from ∼30% for trimethoprim/sulfamethoxazole and oral penicillin to 100% for fluoroquinolones. Among isolates of H. influenzae from Cambodia (n = 30), the Philippines (n = 59) and Singapore (n = 80), rates of susceptibility using CLSI breakpoints were >90% for amoxicillin/clavulanic acid, cephalosporins [except cefaclor in Singapore (77.5%)], macrolides and fluoroquinolones; for isolates from Vietnam (n = 89) the rates of susceptibility were >85% only for amoxicillin/clavulanic acid (95.5%), ceftriaxone (100%) and macrolides (87.6%-89.9%). Susceptibility to other antibiotics ranged from 7.9% (trimethoprim/sulfamethoxazole) to 57.3%-59.6% (fluoroquinolones) and 70.8% (cefixime). The application of different EUCAST breakpoints for low and higher doses for some of the antibiotics (amoxicillin, amoxicillin/clavulanic acid, ampicillin, penicillin, ceftriaxone, clarithromycin, erythromycin, levofloxacin and trimethoprim/sulfamethoxazole) allowed, for the first time in a SOAR study, the effect of raising the dosage on susceptibility to be quantified. A limitation of the study was the small sample sizes and only one or two sites participating per country; however, since susceptibility data are scarce in some of the participating countries any information concerning antibiotic susceptibility is of value.

CONCLUSIONS

Antibiotic susceptibility varied across countries and species, with isolates from Vietnam demonstrating the lowest susceptibility. Knowledge of resistance patterns can be helpful for clinicians when choosing empirical therapy options for CA-RTIs.

A constant pool of Lgr5+ intestinal stem cells is required for intestinal homeostasis

Lgr5⁺ crypt base columnar cells, the operational intestinal stem cells (ISCs), are thought to be dispensable for small intestinal (SI) homeostasis. Using a Lgr5-2A-DTR (diphtheria toxin receptor) model, which ablates Lgr5⁺ cells with near-complete efficiency and retains endogenous levels of Lgr5 expression, we show that persistent depletion of Lgr5⁺ ISCs in fact compromises SI epithelial integrity and reduces epithelial turnover in vivo. In vitro, Lgr5-2A-DTR SI organoids are unable to establish or survive when Lgr5⁺ ISCs are continuously eliminated by adding DT to the media. However, transient exposure to DT at the start of culture allows organoids to form, and the rate of outgrowth reduces with the increasing length of DT presence. Our results indicate that intestinal homeostasis requires a constant pool of Lgr5⁺ ISCs, which is supplied by rapidly reprogrammed non-Lgr5⁺ crypt populations when preexisting Lgr5⁺ ISCs are ablated.

Coxsackievirus A16 in a 1-Day-Old Mouse Model of Central Nervous System Infection Shows Lower Neurovirulence than Enterovirus A71

Coxsackievirus A16 (CV-A16) and enterovirus A71 (EV-A71) are the major causes of hand, foot and mouth disease in young children. Although less so with CV-A16, both viruses are associated with serious neurological syndromes, but the differences between their central nervous system infections remain unclear. We conducted a comparative infection study using clinically-isolated CV-A16 and EV-A71 strains in a 1-day-old mouse model to better understand the neuropathology and neurovirulence of the viruses. New serotype-specific probes for in situ hybridization were developed and validated to detect CV-A16 and EV-A71 RNA in infected tissues. Demonstration of CV-A16 virus antigens/RNA, mainly in the brainstem and spinal cord neurons, confirmed neurovirulence, but showed lower densities than in EV-A71 infected animals. A higher lethal dose₅₀ for CV-A16 suggested that CV-A16 is less neurovirulent. Focal virus antigens/RNA in the anterior horn white matter and adjacent efferent motor nerves suggested that neuroinvasion is possibly via retrograde axonal transport in peripheral motor nerves.

[Clinical application of HRCT three-dimensional reconstruction in traumatic ossicular chain interruption]

Objective:To investigate the clinical value of HRCT three-dimensional reconstruction technique in traumatic auditory chain traumatic fracture. Method:The clinical data of 14 patients with traumatic ear ossicular chain interruption were analyzed retrospectively. To evaluate the injury site and degree of the auditory chain before surgery, all the 14 patients underwent,HRCT scanning and three-dimensional reconstruction. The reconstructed auditory chain was observed from multiple angles and compared with the surgical exploration results under microscope. Result:The coincidence rate between ossicular chain injury observed by temporal bone HRCT scan before operation and ossicular chain injury observed during surgery was only 28.57%, the coincidence rate between ossicular chain injury observed during surgery and ossicular chain injury observed by three-dimensional reconstruction is 85.71%.Therefore, three-dimensional reconstruction imaging technique could give the doctor more clearly and stereoscopic images for the destruction of ossicular chain. Conclusion:Preoperative three-dimensional reconstruction can display and diagnosis of auditory ossicular chain destruction more clearly. It can be used to accurately evaluate auditory ossicular chain pathological changes, to develop individualized surgical plans and assess the risk of surgery.

An accidental laboratory exposure to Brucella melitensis: the prospective post-exposure management and a detailed investigation into the nature of the exposure

Our aim was to prospectively manage 22 Brucella-exposed individuals and identify the lapses in laboratory practices that lead to the exposure. The exposed individuals were risk-stratified, assessed for post-exposure prophylaxis (PEP), counselled to self-monitor symptoms and followed-up with three serology tests. Staff laboratory practices were recorded. Ten out of 13 high-risk individuals received PEP within 48 h of exposure. Compliance with PEP and serology monitoring was 90 and 96 %, respectively. No brucellosis cases were documented. A single handler manipulated the Brucella isolate on the open bench. Movement of the isolate was tracked in detail, highlighting various points of laboratory non-conformance. Early PEP intervention is effective in preventing acquired brucellosis. Our pragmatic post-exposure management achieved high PEP and serology compliance. We experience first-hand how regular staff engagement motivated PEP adherence and interval blood sampling attendance. The enforcement of practical strategies and safety practices was also implemented without compromising our laboratory processing times.

Neonatal Wnt-dependent Lgr5 positive stem cells are essential for uterine gland development

Wnt signaling is critical for directing epithelial gland development within the uterine lining to ensure successful gestation in adults. Wnt-dependent, Lgr5-expressing stem/progenitor cells are essential for the development of glandular epithelia in the intestine and stomach, but their existence in the developing reproductive tract has not been investigated. Here, we employ Lgr5-2A-EGFP/CreERT2/DTR mouse models to identify Lgr5-expressing cells in the developing uterus and to evaluate their stem cell identity and function. Lgr5 is broadly expressed in the uterine epithelium during embryogenesis, but becomes largely restricted to the tips of developing glands after birth. In-vivo lineage tracing/ablation/organoid culture assays identify these gland-resident Lgr5^high cells as Wnt-dependent stem cells responsible for uterine gland development. Adjacent Lgr5^neg epithelial cells within the neonatal glands function as essential niche components to support the function of Lgr5^high stem cells ex-vivo. These findings constitute a major advance in our understanding of uterine development and lay the foundations for investigating potential contributions of Lgr5⁺ stem/progenitor cells to uterine disorders.

Uterine gland development is essential for successful embryo implantation, decidua formation and placental development. Here the authors demonstrate that neonatal Wnt-dependent Lgr5 expressing stem/progenitor cells at the tips of developing glands are indispensable for uterine gland development.

Giant pedunculated oesophageal liposarcomas: A review of literature and resection techniques

•

Giant oesophageal liposarcomas, a rare but important cause of oesophageal tumours.

•

A review of the current literature focusing on resection techniques.

•

Shift in the treatment paradigm in recent years to endoscopic resection techniques.

•

Decision on type of resection technique depends on tumour characteristics and location.

Introduction and presentation of case

Liposarcomas are rare causes of oesophageal tumours, accounting for <1% of tumours. We present a case of a dedifferentiated oesophageal liposarcoma arising from a giant fibrovascular polyp for which resection was performed via a left cervical oesophagostomy with transgastric retrieval of tumour. We also review the existing literature focusing on discussion of resection techniques.

Discussion

To date, 62 cases of oesophageal liposarcoma have been reported in the literature. They usually occur in males (74.2%), with a median age of 66 years (range 38–84 years). Such tumours present most commonly with dysphagia (69.4%); usually arise from the cervical oesophagus (79%), and are well-differentiated. Treatment options include surgery and recently, endoscopic resection techniques such as submucosal dissection (ESD).

Conclusion

Giant oesophageal liposarcomas are very rare tumours. Such tumours are usually polypoid, arising from a pedicle. As such, resection techniques have shifted away from oesophagectomy to less invasive means such as endoscopic resection or oesophagostomy. Decision on type of resection technique depends on tumour characteristics and location; with the guiding principle being resection with clear margins in order to prevent local recurrence.

P4639Plasma tissue factor coagulation activity in post-acute myocardial infarction patients

Background

Coagulation is involved in fibroproliferative responses following acute myocardial infarction (AMI). Left ventricular (LV) remodeling following AMI is closely associated with progression to heart failure.

Purpose

We aimed to evaluate the association of plasma tissue factor (TF) coagulation activity with LV remodeling prior to heart failure in post-AMI patients.

Methods

This study was conducted in 228 subjects from the Post-AMI Left Ventricular Remodeling Biomarker Analysis (PAMILA) study and 57 healthy subjects. The post-AMI patients were divided into two age- and sex-matched groups: patients with adverse LV remodeling defined as an increase in LV end systolic volume by ≥15% over 6 months and patients with reverse LV remodeling defined as an decrease in LV end systolic volume by ≥15% over 6 months. TF coagulation activity was determined using human coagulation factor Xa generation based TF chromogenic activity assay and converted into concentrations of active TF (pM). Sodium-citrate anticoagulated plasma was collected at baseline (within 3 days after revascularization), 30 days and 6 months post-AMI. Results are presented as mean±S.E.M. One-way or two-way repeated measures ANOVA or a multiple multi-level longitudinal data analysis with structural equation model was used to assess differences in coagulation activity. P<0.05 was considered statistically significant.

Results

Plasma from healthy subjects and post-AMI patients at baseline had similar concentrations of active TF (TFa): 29.0±1.4 versus 29.1±0.7 pM. Patients treated with warfarin (15 out of 228 patients) showed lower plasma levels of TFa (mean difference −15.2 pM, [95% CI: −18.7, −11.7], p<0.001). Compared to baseline, plasma levels of TFa in the patients was significantly lower at 30 days post-AMI (mean difference −6.9 pM, [95% CI: −4.8, −8.9], p<0.001) and 6 months post-AMI (mean difference −2.8 pM, [95% CI: −0.8, −4.8], p=0.003). Intriguingly, plasma levels of TFa tended to recover from 30 days to 6 months post-AMI (mean difference 4.1 pM, [95% CI: 2.8, 5.4], p<0.001) toward the baseline level and the level in healthy subjects. Similar trends of temporal changes of plasma TFa levels were observed in patients with adverse LV remodeling and those with reverse LV remodeling although TFa levels were slightly higher in patients with reverse LV remodeling (F(2,448)=3.112, p=0.045 for interaction). After adjusting for age, gender, ethnicity, medications, lipid profile and risk factors, the temporal changes of plasma TFa levels in patients remain significant, however, the difference between patients with adverse versus reverse LV remodeling was not significant.

Conclusion

Plasma TF coagulation activity decreased post-AMI but did not differ in patients with adverse versus reverse LV remodeling.

Acknowledgement/Funding

National University Health System Singapore (NUHS O-CRG 2016 Oct-23) to JW Wang

P2582Signature of plasma extracellular vesicles associated proteins in acute myocardial infarction patients

Background

Prediction of left ventricular (LV) remodeling post-acute myocardial infarction (AMI) remains challenging. Several circulating biomarkers have been associated with post-AMI LV remodeling, however, there is no biomarker available to distinguish adverse versus reverse LV remodeling.

Purpose

In this study, we aimed to assess the association of extracellular vesicles (EVs) associated proteins with LV remodeling post-AMI.

Methods

Plasma EVs were isolated via precipitation with dextran sulphate as we previously reported. The protein levels of EV associated von Willebrand factor (VWF), SerpinC1 (antithrombin-III), plasminogen and SerpinF2 (alpha 2-antiplasmin) were determined in the citrate-anticoagulated plasma from 57 healthy subjects and 200 patients recruited in the Post-AMI Left Ventricular Remodeling Biomarker Analysis (PAMILA) study. Patients were categorized into two groups: adverse LV remodeling (n=100) characterized by an increase or reverse LV remodeling (n=100) characterized by a decrease, in LV end systolic volume by ≥15% over 6 months. Patients' plasma was collected at baseline (within 3 days after percutaneous coronary intervention), 1 month and 6 months post-AMI. Log transformation of EV protein levels was performed for assessment in a multiple multi-level longitudinal data analysis with structural equation model (with level of significance fixed at 0.05).

Results

Compared to healthy subjects, baseline protein levels of EV associated VWF and SerpinF2 were significantly higher in post-AMI patients, whereas no difference was observed in SerpinC1 and plasminogen. Among the patients, those on statins (196 out of 200 patients) showed lower protein levels of EV associated VWF (p<0.001) and plasminogen (p=0.003), whereas patients treated with P2Y12 platelet inhibitors (195 out of 200 patients) showed higher protein levels of EV associated VWF (p=0.003) and plasminogen (p=0.035). Multiple multi-level longitudinal data analysis with structural equation model showed that protein levels of EV associated VWF (p<0.001) and SerpinC1 (p=0.021) were lower in patients with adverse LV remodeling than that in patients with reverse LV remodeling during the 6-month follow-up post-AMI. In contrast, protein levels of EV associated plasminogen (p=0.002) and SerpinF2 (p=0.002) were higher in patients with adverse LV remodeling. The differences in the four EV associated proteins between patients with adverse versus reverse LV remodeling remain significant after adjusting for age, gender, ethnicity, medications, lipid profile and risk factors (diabetes, hypertension, dyslipidemia and smoking).

Conclusions

Lower levels of EV associated coagulation proteins (VWF and SerpinC1) and higher levels of EV associated fibrinolytic proteins (plasminogen and SerpinF2) were presented in patients with adverse LV remodeling compared to those with reverse LV remodeling post-AMI.

Acknowledgement/Funding

National University Health System Singapore (NUHS O-CRG 2016 Oct-23) to JW Wang

Epidemiology and prognostic factors for mycosis fungoides and Sézary syndrome in a multi-ethnic Asian cohort: a 12-year review

BACKGROUND

Limited information exists regarding survival of Asian patients with mycosis fungoides (MF) and Sézary syndrome (SS).

OBJECTIVE

To evaluate the epidemiology, outcome and prognostic factors of these patients.

METHODS

A retrospective review of MF/SS cases diagnosed from 2000 to 2011 at a tertiary referral dermatology centre in Singapore was performed.

RESULTS

Of 246 patients, 63% were male and the median age at diagnosis was 49 years. 73.2% were Chinese, 12.6% Indian, 6.9% Malay and 7.3% Caucasian. A total of 239 patients (97.2%) had MF and seven had SS. Median follow-up duration was 6.3 years, and median duration of symptoms at diagnosis was 13 months. For patients with MF, the majority had early disease (92.8% stage IA-IIA). 3.8% were stage IIB, 1.7% stage III and 1.7% stage IV. Complete response to treatment occurred in 78.2%, partial response in 9.6%, persistent but non-progressive disease in 10.0% and disease progression in 4.1% of patients. Large cell transformation occurred in 4.1% of patients. Mean overall survival during this study was 12.7 years, with death occurring in 2.5% of patients (all ≥stage IIB at diagnosis). For patients with SS, 71.4% presented with stage IVA disease, 28.6% stage IVB. Complete response to treatment occurred in 14.2%, persistent but non-progressive disease in 28.6% and disease progression in 57.2% of patients. Mean overall survival was 3.3 years within this study, with death occurring in 42.9% of SS patients. Prognostic factors associated with favourable recurrence-free survival were male gender (P = 0.008), early disease stage (T1) at diagnosis (P < 0.001) and absence of maintenance treatment after remission (P = 0.01).

CONCLUSION

Compared to Caucasian and East Asian cohorts, MF in South-East Asians was diagnosed at a younger age and associated with lower mortality, largely due to greater prevalence of hypopigmented MF.

Wnt Signaling in Adult Epithelial Stem Cells and Cancer

Wnt/β-catenin signaling is integral to the homeostasis and regeneration of many epithelial tissues due to its critical role in adult stem cell regulation. It is also implicated in many epithelial cancers, with mutations in core pathway components frequently present in patient tumors. In this chapter, we discuss the roles of Wnt/β-catenin signaling and Wnt-regulated stem cells in homeostatic, regenerative and cancer contexts of the intestines, stomach, skin, and liver. We also examine the sources of Wnt ligands that form part of the stem cell niche. Despite the diversity in characteristics of various tissue stem cells, the role(s) of Wnt/β-catenin signaling is generally coherent in maintaining stem cell fate and/or promoting proliferation. It is also likely to play similar roles in cancer stem cells, making the pathway a salient therapeutic target for cancer. While promising progress is being made in the field, deeper understanding of the functions and signaling mechanisms of the pathway in individual epithelial tissues will expedite efforts to modulate Wnt/β-catenin signaling in cancer treatment and tissue regeneration.

APOBEC signature mutation generates an oncogenic enhancer that drives LMO1 expression in T-ALL

Oncogenic driver mutations are those that provide a proliferative or survival advantage to neoplastic cells, resulting in clonal selection. Although most cancer-causing mutations have been detected in the protein-coding regions of the cancer genome; driver mutations have recently also been discovered within noncoding genomic sequences. Thus, a current challenge is to gain precise understanding of how these unique genomic elements function in cancer pathogenesis, while clarifying mechanisms of gene regulation and identifying new targets for therapeutic intervention. Here we report a C-to-T single nucleotide transition that occurs as a somatic mutation in noncoding sequences 4 kb upstream of the transcriptional start site of the LMO1 oncogene in primary samples from patients with T-cell acute lymphoblastic leukaemia. This single nucleotide alteration conforms to an APOBEC-like cytidine deaminase mutational signature, and generates a new binding site for the MYB transcription factor, leading to the formation of an aberrant transcriptional enhancer complex that drives high levels of expression of the LMO1 oncogene. Since APOBEC-signature mutations are common in a broad spectrum of human cancers, we suggest that noncoding nucleotide transitions such as the one described here may activate potent oncogenic enhancers not only in T-lymphoid cells but in other cell lineages as well.

In vivo lineage tracing reveals Axin2-expressing, long-lived cortical thymic epithelial progenitors in the postnatal thymus

In the thymus, cortical and medullary thymic epithelial cells (TECs) are instrumental for generating a repertoire of functional T cells. Hence, there has been much interest in the ontogeny of TECs. While medullary TEC (mTEC) and bipotent progenitors have been identified, the existence of a cortical TEC (cTEC) progenitor remains ambiguous. In this study, we used lineage tracing based on a target gene of the Wnt pathway, Axin2. We found that Axin2 initially labels cells in both the cortical and medullary compartments. Using Axin2-CreERT2 mice to track the fate of labelled cells, we identified long-lived cortical TEC progenitors that give rise to expanding clones and contribute to homeostasis in postnatal thymus. In contrast, no clonal expansion was found in the medullary or in the K5K8-double positive compartments. The identification of cTEC progenitors and their regulation by Wnt signaling have important implications for our understanding of thymus physiology during homeostasis and TEC-related disorders.

Restoration of shoulder abduction in brachial plexus avulsion injuries with double neurotization from the spinal accessory nerve: a report of 13 cases

In upper (C5-C7) and total (C5-T1) root avulsion brachial plexus injury, a method of double neurotization from a single donor spinal accessory nerve to two target nerves (suprascapular nerve and axillary nerve) may be done, leaving donor nerves available for reconstruction procedures to restore other aspects of upper limb function. A mean range of shoulder abduction of 91° (SD 25°) was achieved through this procedure in our study of 13 cases, of which seven cases were C5-C7 root avulsion and six cases were C5-T1 root avulsion brachial plexus injuries. Six of the former group and three of the latter group achieved >90° shoulder abduction. The technique of double neurotization from a single donor nerve provides favourable results in restoring shoulder abduction in avulsion brachial plexus injuries.

LEVEL OF EVIDENCE

IV.

Lgr5-expressing chief cells drive epithelial regeneration and cancer in the oxyntic stomach

The daily renewal of the corpus epithelium is fuelled by adult stem cells residing within tubular glands, but the identity of these stem cells remains controversial. Lgr5 marks homeostatic stem cells and 'reserve' stem cells in multiple tissues. Here, we report Lgr5 expression in a subpopulation of chief cells in mouse and human corpus glands. Using a non-variegated Lgr5-2A-CreERT2 mouse model, we show by lineage tracing that Lgr5-expressing chief cells do not behave as corpus stem cells during homeostasis, but are recruited to function as stem cells to effect epithelial renewal following injury by activating Wnt signalling. Ablation of Lgr5⁺ cells severely impairs epithelial homeostasis in the corpus, indicating an essential role for these Lgr5⁺ cells in maintaining the homeostatic stem cell pool. We additionally define Lgr5⁺ chief cells as a major cell-of-origin of gastric cancer. These findings reveal clinically relevant insights into homeostasis, repair and cancer in the corpus.

Development and validation of algorithms for the detection of statin myopathy signals from electronic medical records

The purpose of this study was to develop and validate sensitive algorithms to detect hospitalized statin-induced myopathy (SIM) cases from electronic medical records (EMRs). We developed four algorithms on a training set of 31,211 patient records from a large tertiary hospital. We determined the performance of these algorithms against manually curated records. The best algorithm used a combination of elevated creatine kinase (>4× the upper limit of normal (ULN)), discharge summary, diagnosis, and absence of statin in discharge medications. This algorithm achieved a positive predictive value of 52-71% and a sensitivity of 72-78% on two validation sets of >30,000 records each. Using this algorithm, the incidence of SIM was estimated at 0.18%. This algorithm captured three times more rhabdomyolysis cases than spontaneous reports (95% vs. 30% of manually curated gold standard cases). Our results show the potential power of utilizing data and text mining of EMRs to enhance pharmacovigilance activities.

Organoids as an in vitro model of human development and disease

The in vitro organoid model is a major technological breakthrough that has already been established as an essential tool in many basic biology and clinical applications. This near-physiological 3D model facilitates an accurate study of a range of in vivo biological processes including tissue renewal, stem cell/niche functions and tissue responses to drugs, mutation or damage. In this Review, we discuss the current achievements, challenges and potential applications of this technique.

Stemming Colorectal Cancer Growth and Metastasis: HOXA5 Forces Cancer Stem Cells to Differentiate

Wnt signaling drives colorectal cancer stem cells, but effective therapeutics targeting these cells and their signaling pathways are lacking. In this issue of Cancer Cell, Ordóñez-Morán and colleagues describe a promising therapeutic intervention for colorectal cancers that selectively induces cancer stem cell differentiation through HOXA5 expression and Wnt signaling inhibition.

Mutant p53-R273H mediates cancer cell survival and anoikis resistance through AKT-dependent suppression of BCL2-modifying factor (BMF)

p53 is the most frequently mutated tumor-suppressor gene in human cancers. Unlike other tumor-suppressor genes, p53 mutations mainly occur as missense mutations within the DNA-binding domain, leading to the expression of full-length mutant p53 protein. Mutant p53 proteins not only lose their tumor-suppressor function, but may also gain new oncogenic functions and promote tumorigenesis. Here, we showed that silencing of endogenous p53-R273H contact mutant, but not p53-R175H conformational mutant, reduced AKT phosphorylation, induced BCL2-modifying factor (BMF) expression, sensitized BIM dissociation from BCL-X_L and induced mitochondria-dependent apoptosis in cancer cells. Importantly, cancer cells harboring endogenous p53-R273H mutant were also found to be inherently resistant to anoikis and lack BMF induction following culture in suspension. Underlying these activities is the ability of p53-R273H mutant to suppress BMF expression that is dependent on constitutively active PI3K/AKT signaling. Collectively, these findings suggest that p53-R273H can specifically drive AKT signaling and suppress BMF expression, resulting in enhanced cell survivability and anoikis resistance. These findings open the possibility that blocking of PI3K/AKT will have therapeutic benefit in mutant p53-R273H expressing cancers.

Simplified noncultured autologous cell grafting for the treatment of chronic nonhealing ulcers: the six-well plate technique

Chronic recalcitrant ulcers are associated with severe morbidity, and there are few effective treatment options available. Living skin substitutes are an important form of adjuvant therapy to enhance healing of such wounds. We investigated a novel, simplified, noncultured, autologous, cell grafting procedure, using a six-well plate technique, to treat chronic recalcitrant wounds. This was a prospective pilot study that involved harvesting an ultrathin split-skin graft from the gluteal region, which was washed, separated and prepared in six different wells to obtain an autologous mixture of keratinocytes, melanocytes and fibroblasts; this was subsequently applied directly to the wound using a hyaluronic acid (HA) matrix. Eight patients with a total of 14 ulcers were recruited. The primary endpoint assessed was the percentage of re-epithelialization of the ulcers. Secondary endpoints included quality of life and wound bed indices. At baseline, the median wound surface area was 7.4 cm(2) (mean 17.6 ± 23.6 cm(2) , range 0.5-80.0 cm(2) ) with a median duration of 18 months (mean 70.2 ± 95.9, range 3-216 months). The median wound surface area was reduced by 74.3%, from 7.4-1.9 cm(2) , at the final visit. Overall, 28.3% of the ulcers achieved complete healing, and 71.3% of the ulcers had reduction in wound size. Post-graft, there was also improvement in secondary wound bed parameters and all quality of life domains of the Cardiff Wound Impact Schedule. These results suggest that this noncultured autologous six-well technique might be beneficial for treating recalcitrant ulcers.

Mortality of bullous pemphigoid in Singapore: risk factors and causes of death in 359 patients seen at the National Skin Centre

BACKGROUND

Bullous pemphigoid (BP) is the most common autoimmune-mediated subepidermal blistering skin disease and is associated with significant morbidity and mortality.

OBJECTIVES

To determine the 3-year mortality rate, risk factors and causes of death in patients with BP in Singapore, compared with the general population.

METHODS

We conducted a retrospective cohort study of all newly diagnosed patients with BP seen at the National Skin Centre from 1 April 2004 to 31 December 2009. Demographic and clinical data on comorbidities and treatment were recorded. Mortality information was obtained from the National Registry of Diseases.

RESULTS

In total 359 patients were included in our study. The 1-, 2-, 3-year mortality rates were 26·7%, 38·4% and 45·7%, respectively. The 3-year standardized mortality risk for patients with BP was 2·74 (95% confidence interval 2·34-3·19) times higher than for the age- and sex-matched general population. Parkinson disease, heart failure and chronic renal disease were associated with increased mortality, while combination treatment with low-to-moderate-dose corticoste-roids and immunomodulatory agents such as doxycycline and/or nicotinamide was associated with lower mortality. Overall, infections were the most common cause of death (59·8%), with the main causes of death being pneumonia (42·7%), cardiovascular disease (14·6%) and stroke (11·6%).

CONCLUSIONS

This study confirms an increased 3-year mortality rate for patients with BP in Singapore. Risk factors for increased mortality include medical comorbidities, especially neurological, cardiac and renal diseases. Treatment with combination therapy, including the use of low-to-moderate-dose corticosteroid, appeared to decrease mortality risk in patients with BP.

ERG rearrangement and protein expression in the progression to castration-resistant prostate cancer

BACKGROUND

Approximately half of the prostate carcinomas are characterized by a chromosomal rearrangement fusing the androgen-regulated gene TMPRSS2 to the oncogenic ETS transcription factor ERG. Aim of this study was to comprehensively analyze the role and impact of the ERG rearrangement and protein expression on the progression to castration-resistant (CR) disease.

METHODS

We used a tissue microarray (TMA) constructed from 114 hormone naive (HN) and 117 CR PCs. We analyzed the ERG rearrangement status by fluorescence in situ hybridization and the expression profiles of ERG, androgen receptor (AR) and the proliferation marker Ki67 by immunohistochemistry.

RESULTS

Nearly half of the PC tissue specimens (HN: 38%, CR: 46%) harbored a TMPRSS2-ERG gene fusion. HN PCs with positive translocation status showed increased tumor cell proliferation (P<0.05). As expected, TMPRSS2-ERG gene fusion was strongly associated with increased ERG protein expression in HN and CR PCs (both P<0.0001). Remarkably, the study revealed a subgroup (26%) of CR PCs with ERG rearrangement but without any detectable ERG protein expression. This subgroup showed significantly lower levels of AR protein expression and androgen-regulated serum PSA (both P<0.05).

CONCLUSIONS

In this study, we identified a subgroup of ERG-rearranged CR PCs without detectable ERG protein expression. Our results suggest that this subgroup could represent CR PCs with a dispensed AR pathway. These tumors might represent a thus far unrecognized subset of patients with AR-independent CR PC who may not benefit from conventional therapy directed against the AR pathway.

Chemical identification and behavioral characterization of male wing pheromone ofEphestia elutella (Pyralidae)

Behavioral and chemical evidence is presented for the identity of the male wing pheromone ofEphestia elutella (Hübner) and the role of this pheromone in courtship success is evaluated. Males with the forewing removed experienced a mating success rate less than half of that of either intact males or males that had only the wing gland area remaining of their forewings. GC-MS analysis and microchemical reactions indicated the presence of (E)-phytol and a series of saturated γ-lactones in a methylene chloride extract of the wings. Using an assay of female courtship behavioral response, (E)-phytol was found to evoke an intermediate level of response in females when presented alone, while the complete array of insect-derived γ-lactones produced no significant response. The combination of either γ-decalactone or γ-undecalactone with (E)-phytol in a 1∶2 ratio, however, elicited a female response equivalent to that produced by the unfractionated wing extract.

Interfollicular epidermal stem cells self-renew via autocrine Wnt signaling

The skin is a classical example of a tissue maintained by stem cells. However, the identity of the stem cells that maintain the interfollicular epidermis and the source of the signals that control their activity remain unclear. Using mouse lineage tracing and quantitative clonal analyses, we showed that the Wnt target gene Axin2 marks interfollicular epidermal stem cells. These Axin2-expressing cells constitute the majority of the basal epidermal layer, compete neutrally, and require Wnt/β-catenin signaling to proliferate. The same cells contribute robustly to wound healing, with no requirement for a quiescent stem cell subpopulation. By means of double-labeling RNA in situ hybridization in mice, we showed that the Axin2-expressing cells themselves produce Wnt signals as well as long-range secreted Wnt inhibitors, suggesting an autocrine mechanism of stem cell self-renewal.