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.

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.

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.

On-Demand Droplet Merging with an AC Electric Field for Multiple-Volume Droplet Generation

We introduce a unique system to achieve on-demand droplet merging and splitting using a perpendicular AC electric field. The working mechanism involves a micropillar to split droplets, followed by electrocoalescence using an AC electric field. Adjusting the parameters of the AC signal and conductivity of the fluid result in different merging regimes. We observed a minimum threshold voltage and a strong influence of the surfactant. We hypothesize that the merging process is caused by dipole-dipole coalescence between the daughter droplets. At the same time, adjustment of the conductivity reveals a shift in the merging regimes and can be explained with an electric circuit diagram. Size-based sorting using this merging phenomenon is subsequently demonstrated, where alternate, single, double, and triple droplets sorting were achieved. The concept presented in this paper is potentially useful for drug dispensing or multivolume digital polymerase chain reaction, as droplets of multiple sizes can be generated simultaneously.

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.

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.

Nanoscale silicon surface-assisted laser desorption/ionization mass spectrometry: environment stability and activation by simple vacuum oven desiccation

Nanoscale silicon surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is an emerging matrix-free, highly sensitive MS analysis method. An important challenge in using nanoscale silicon SALDI-MS analysis is the aging and stability of silicon after storage in various environments. No proper nanoscale silicon SALDI-MS activation procedure has been reported to solve this issue. This study investigated the sensitivity, wettability, and surface oxidation behavior of nanoscale silicon surface SALDI-MS in a room, an inert gas atmosphere, and a vacuum environment. A simple vacuum oven desiccation was proposed to activate the SALDI-MS surface, and the limit of detection was further enhanced 1000 times to a 500 attomole level using this approach. The long-term stability and desorption/ionization mechanism were also investigated.

Opto-acousto-fluidic microscopy for three-dimensional label-free detection of droplets and cells in microchannels

This paper reports a novel method, opto-acousto-fluidic microscopy, for label-free detection of droplets and cells in microfluidic networks. Leveraging the optoacoustic effect, the microscopic system possesses capabilities of visualizing flowing droplets, analyzing droplet contents, and detecting cell populations encapsulated in droplets via the sensing of acoustic waves induced by the intrinsic light-absorbance of matter.

High-Throughput Separation of White Blood Cells From Whole Blood Using Inertial Microfluidics

White blood cells (WBCs) constitute only about 0.1% of human blood cells, yet contain rich information about the immune status of the body; thus, separation of WBCs from the whole blood is an indispensable and critical sample preparation step in many scientific, clinical, and diagnostic applications. In this paper, we developed a continuous and high-throughput microfluidic WBC separation platform utilizing the differential inertial focusing of particles in serpentine microchannels. First, separation performance of the proposed method is characterized and evaluated using polystyrene beads in the serpentine channel. The purity of 10-μm polystyrene beads is increased from 0.1% to 80.3% after two cascaded processes, with an average enrichment ratio of 28 times. Next, we investigated focusing and separation properties of Jurkat cells spiked in the blood to mimic the presence of WBCs in whole blood. Finally, separation of WBCs from human whole blood was conducted and separation purity of WBCs was measured by the flow cytometry. The results show that the purity of WBCs can be increased to 48% after two consecutive processes, with an average enrichment ratio of ten times. Meanwhile, a parallelized inertial microfluidic device was designed to provide a high processing flow rate of 288 ml/h for the diluted (×1/20) whole blood. The proposed microfluidic device can potentially work as an upstream component for blood sample preparation and analysis in the integrated microfluidic systems.

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.

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.

Editorial for the Special Issue on the Insights and Advancements in Microfluidics

We present a total of 19 articles in this special issue of Micromachines entitled, "Insights and Advancements in Microfluidics."[...].

Active droplet sorting in microfluidics: a review

The ability to manipulate and sort droplets is a fundamental issue in droplet-based microfluidics. Various lab-on-a-chip applications can only be realized if droplets are systematically categorized and sorted. These micron-sized droplets act as ideal reactors which compartmentalize different biological and chemical reagents. Array processing of these droplets hinges on the competence of the sorting and integration into the fluidic system. Recent technological advances only allow droplets to be actively sorted at the rate of kilohertz or less. In this review, we present state-of-the-art technologies which are implemented to efficiently sort droplets. We classify the concepts according to the type of energy implemented into the system. We also discuss various key issues and provide insights into various systems.

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.

Sheathless Dean-flow-coupled elasto-inertial particle focusing and separation in viscoelastic fluid

Sheathless particle focusing and separation in viscoelastic fluid is demonstrated using an integrated ECCA (straight channel section with asymmetrical expansion–contraction cavity arrays) straight channel.

A Microfluidic Method for Investigating Ion-Specific Bubble Coalescence in Salt Solutions

This paper reports the direct and precise measurement of bubble coalescence in salt solutions using microfluidics. We directly visualized the bubble coalescence process in a microchannel using high-speed imaging and evaluated the shortest coalescence time to determine the transition concentration of sodium halide solutions. We found the transition concentration is ion-specific, and the capacity of sodium halide salts to inhibit bubble coalescence follows the order of NaF > NaCl > NaBr > NaI. The microfluidic method overcomes the inherent uncertainties in conventional large-scale devices and methods.

A novel viscoelastic-based ferrofluid for continuous sheathless microfluidic separation of nonmagnetic microparticles

Separation of microparticles has found broad applications in biomedicine, industry and clinical diagnosis. In a conventional aqueous ferrofluid, separation of microparticles usually employs a sheath flow or two offset magnets to confine particle streams for downstream particle sorting. This complicates the fluid control, device fabrication, and dilutes the particle sample. In this work, we propose and develop a novel viscoelastic ferrofluid by replacing the Newtonian base medium of the conventional ferrofluid with non-Newtonian poly(ethylene oxide) (PEO) aqueous solution. The properties of both viscoelastic 3D focusing and negative magnetophoresis of the viscoelastic ferrofluid were verified and investigated. By employing the both properties in a serial manner, continuous and sheathless separation of nonmagnetic particles based on particle size has been demonstrated. This novel viscoelastic ferrofluid is expected to bring more flexibility and versatility to the design and functionality in microfluidic devices.

AC electric field induced droplet deformation in a microfluidic T-junction

We present for the first time an experimental study on the droplet deformation induced by an AC electric field in droplet-based microfluidics. It is found that the deformation of the droplets becomes stronger with increasing electric field intensity and frequency. The measured electric field intensity dependence of the droplet deformation is consistent with an early theoretical prediction for stationary droplets. We also proposed a simple equivalent circuit model to account for the frequency dependence of the droplet deformation. The model well explains our experimental observations. In addition, we found that the droplets can be deformed repeatedly by applying an amplitude modulation (AM) signal.

AC electrified jets in a flow-focusing device: Jet length scaling

We use a microfluidic flow-focusing device with integrated electrodes for controlling the production of water-in-oil drops. In a previous work, we reported that very long jets can be formed upon application of AC fields. We now study in detail the appearance of the long jets as a function of the electrical parameters, i.e., water conductivity, signal frequency, and voltage amplitude. For intermediate frequencies, we find a threshold voltage above which the jet length rapidly increases. Interestingly, this abrupt transition vanishes for high frequencies of the signal and the jet length grows smoothly with voltage. For frequencies below a threshold value, we previously reported a transition from a well-behaved uniform jet to highly unstable liquid structures in which axisymmetry is lost rather abruptly. These liquid filaments eventually break into droplets of different sizes. In this work, we characterize this transition with a diagram as a function of voltage and liquid conductivity. The electrical response of the long jets was studied via a distributed element circuit model. The model allows us to estimate the electric potential at the tip of the jet revealing that, for any combination of the electrical parameters, the breakup of the jet occurs at a critical value of this potential. We show that this voltage is around 550 V for our device geometry and choice of flow rates.

Active droplet generation in microfluidics

The reliable generation of micron-sized droplets is an important process for various applications in droplet-based microfluidics. The generated droplets work as a self-contained reaction platform in droplet-based lab-on-a-chip systems. With the maturity of this platform technology, sophisticated and delicate control of the droplet generation process is needed to address increasingly complex applications. This review presents the state of the art of active droplet generation concepts, which are categorized according to the nature of the induced energy. At the liquid/liquid interface, an energy imbalance leads to instability and droplet breakup.

Silicon etching using only Oxygen at high temperature: An alternative approach to Si micro-machining on 150 mm Si wafers

Using a combination of low-pressure oxygen and high temperatures, isotropic and anisotropic silicon (Si) etch rates can be controlled up to ten micron per minute. By varying the process conditions, we show that the vertical-to-lateral etch rate ratio can be controlled from 1:1 isotropic etch to 1.8:1 anisotropic. This simple Si etching technique combines the main respective advantages of both wet and dry Si etching techniques such as fast Si etch rate, stiction-free, and high etch rate uniformity across a wafer. In addition, this alternative O₂-based Si etching technique has additional advantages not commonly associated with dry etchants such as avoiding the use of halogens and has no toxic by-products, which improves safety and simplifies waste disposal. Furthermore, this process also exhibits very high selectivity (>1000:1) with conventional hard masks such as silicon carbide, silicon dioxide and silicon nitride, enabling deep Si etching. In these initial studies, etch rates as high as 9.2 μm/min could be achieved at 1150 °C. Empirical estimation for the calculation of the etch rate as a function of the feature size and oxygen flow rate are presented and used as proof of concepts.

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.

Acoustofluidic control of bubble size in microfluidic flow-focusing configuration

This paper reports a method to control the bubble size generated in a microfluidic flow-focusing configuration. With an ultrasonic transducer, we induce acoustic streaming using a forward moving, oscillating gas-liquid interface. The induced streaming substantially affects the formation process of gas bubbles. The oscillating interface acts as a pump that increases the gas flow rate significantly and forms a larger bubble. This method is applicable to a wide range of gas pressure from 30 to 90 kPa and flow rate from 380 to 2700 μL h(-1). The bubble size can be tuned repeatedly with the response time on the order of seconds. We believe that this method will enhance the capability of a microfluidic bubble generator to produce a tunable bubble size.

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.

The microfluidic jukebox

Music is a form of art interweaving people of all walks of life. Through subtle changes in frequencies, a succession of musical notes forms a melody which is capable of mesmerizing the minds of people. With the advances in technology, we are now able to generate music electronically without relying solely on physical instruments. Here, we demonstrate a musical interpretation of droplet-based microfluidics as a form of novel electronic musical instruments. Using the interplay of electric field and hydrodynamics in microfluidic devices, well controlled frequency patterns corresponding to musical tracks are generated in real time. This high-speed modulation of droplet frequency (and therefore of droplet sizes) may also provide solutions that reconciles high-throughput droplet production and the control of individual droplet at production which is needed for many biochemical or material synthesis applications.

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.

Microfluidic flow-focusing in ac electric fields

We demonstrate the control of droplet sizes by an ac voltage applied across microelectrodes patterned around a flow-focusing junction. The electrodes do not come in contact with the fluids to avoid electrochemical effects. We found several regimes of droplet production in electric fields, controlled by the connection of the chip, the conductivity of the dispersed phase and the frequency of the applied field. A simple electrical modelling of the chip reveals that the effective voltage at the tip of the liquid to be dispersed controls the production mechanism. At low voltages (≲ 600 V), droplets are produced in dripping regime; the droplet size is a function of the ac electric field. The introduction of an effective capillary number that takes into account the Maxwell stress can explain the dependance of droplet size with the applied voltage. At higher voltages (≳ 600 V), jets are observed. The stability of droplet production is a function of the fluid conductivity and applied field frequency reported in a set of flow diagrams.