Circular RNA as a source of neoantigens for cancer vaccines

BACKGROUND

The effectiveness of somatic neoantigen-based immunotherapy is often hindered by the limited number of mutations in tumors with low to moderate mutation burden. Focusing on microsatellite-stable colorectal cancer (CRC), this study investigates the potential of tumor-associated circular RNAs (circRNAs) as an alternative source of neoepitopes in CRC.

METHODS

Tumor-associated circRNAs in CRC were identified using the MiOncoCirc database and ribo-depletion RNA sequencing of paired clinical normal and tumor samples. Candidate circRNA expression was validated by quantitative real-time PCR (RT-qPCR) using divergent primers. TransCirc database was used for translation prediction. Human leukocyte antigen binding affinity of open reading frames from potentially translatable circRNA was predicted using pVACtools. Strong binders from messenger RNA-encoded proteins were excluded using BlastP. The immunogenicity of the candidate antigens was functionally validated through stimulation of naïve CD8+ T cells against the predicted neoepitopes and subsequent analysis of the T cells through enzyme-linked immunospot (ELISpot) assay, intracellular cytokine staining (ICS) and granzyme B (GZMB) reporter. The cytotoxicity of T cells trained with antigen peptides was further tested using patient-derived organoids.

RESULTS

We identified a neoepitope from circRAPGEF5 that is upregulated in CRC tumor samples from MiOncoCirc database, and two neoepitopes from circMYH9, which is upregulated across various tumor samples from our matched clinical samples. The translation potential of candidate peptides was supported by Clinical Proteomic Tumor Analysis Consortium database using PepQuery. The candidate peptides elicited antigen-specific T cells response and expansion, evidenced by various assays including ELISpot, ICS and GZMB reporter. Furthermore, T cells trained with circMYH9 peptides were able to specifically target and eliminate tumor-derived organoids but not match normal organoids. This observation underscores the potential of circRNAs as a source of immunogenic neoantigens. Lastly, circMYH9 was enriched in the liquid biopsies of patients with CRC, thus enabling a detection-to-vaccination treatment strategy for patients with CRC.

CONCLUSIONS

Our findings underscore the feasibility of tumor-associated circRNAs as an alternative source of neoantigens for cancer vaccines targeting tumors with moderate mutation levels.

Evaluation of a quality improvement intervention to reduce anastomotic leak following right colectomy (EAGLE): pragmatic, batched stepped-wedge, cluster-randomized trial in 64 countries

BACKGROUND

Anastomotic leak affects 8 per cent of patients after right colectomy with a 10-fold increased risk of postoperative death. The EAGLE study aimed to develop and test whether an international, standardized quality improvement intervention could reduce anastomotic leaks.

METHODS

The internationally intended protocol, iteratively co-developed by a multistage Delphi process, comprised an online educational module introducing risk stratification, an intraoperative checklist, and harmonized surgical techniques. Clusters (hospital teams) were randomized to one of three arms with varied sequences of intervention/data collection by a derived stepped-wedge batch design (at least 18 hospital teams per batch). Patients were blinded to the study allocation. Low- and middle-income country enrolment was encouraged. The primary outcome (assessed by intention to treat) was anastomotic leak rate, and subgroup analyses by module completion (at least 80 per cent of surgeons, high engagement; less than 50 per cent, low engagement) were preplanned.

RESULTS

A total 355 hospital teams registered, with 332 from 64 countries (39.2 per cent low and middle income) included in the final analysis. The online modules were completed by half of the surgeons (2143 of 4411). The primary analysis included 3039 of the 3268 patients recruited (206 patients had no anastomosis and 23 were lost to follow-up), with anastomotic leaks arising before and after the intervention in 10.1 and 9.6 per cent respectively (adjusted OR 0.87, 95 per cent c.i. 0.59 to 1.30; P = 0.498). The proportion of surgeons completing the educational modules was an influence: the leak rate decreased from 12.2 per cent (61 of 500) before intervention to 5.1 per cent (24 of 473) after intervention in high-engagement centres (adjusted OR 0.36, 0.20 to 0.64; P < 0.001), but this was not observed in low-engagement hospitals (8.3 per cent (59 of 714) and 13.8 per cent (61 of 443) respectively; adjusted OR 2.09, 1.31 to 3.31).

CONCLUSION

Completion of globally available digital training by engaged teams can alter anastomotic leak rates. Registration number: NCT04270721 (http://www.clinicaltrials.gov).

Observation of Collider Muon Neutrinos with the SND@LHC Experiment

We report the direct observation of muon neutrino interactions with the SND@LHC detector at the Large Hadron Collider. A dataset of proton-proton collisions at sqrt[s]=13.6  TeV collected by SND@LHC in 2022 is used, corresponding to an integrated luminosity of 36.8  fb^{-1}. The search is based on information from the active electronic components of the SND@LHC detector, which covers the pseudorapidity region of 7.2<η<8.4, inaccessible to the other experiments at the collider. Muon neutrino candidates are identified through their charged-current interaction topology, with a track propagating through the entire length of the muon detector. After selection cuts, 8 ν_{μ} interaction candidate events remain with an estimated background of 0.086 events, yielding a significance of about 7 standard deviations for the observed ν_{μ} signal.

Heart failure with improved ejection fraction (HFimpEF) in patients treated with sacubitril/valsartan (SV)

Introduction

Several studies demonstrated that patients with improvement of left ventricular ejection fraction (LVEF) and symptoms had good prognosis in heart failure with reduced ejection fraction (HFrEF). Based on these results, new classification of HF according to LVEF was currently proposed. Sacubitril/valsartan (SV) is recommended as one of the first-line therapy of HFrEF patients. SV reduced hospitalization for HF and cardiovascular mortality compared to enalapril in PARADIGM-HF trial. However, it is unclear that patients with improvement of LVEF also have better prognosis compared to patients without LVEF improvement among patients treated with SV.

Purpose

We aimed to evaluate the clinical characteristics and outcomes of heart failure with improved ejection fraction (HFimpEF) in heart failure with reduced ejection fraction (HFrEF) patients treated with SV.

Methods

We analyzed 230 patients with HFrEF taking SV in a multicenter retrospective cohort (RECORD-SV registry) from 2017 to 2019. Enrolled 230 patients were performed baseline and 1-year follow-up echocardiography. Based on 2 echocardiographic results, we defined “HFimpEF” as HF with a baseline LVEF ≤40%, ≥10% increase from baseline LVEF and a follow-up measurement of LVEF &gt;40%. Others were defined as “Persistent HFrEF”. We analyzed and compared clinical characteristics and outcomes between two groups. Primary endpoint was a composite outcome of all-cause death and hospitalization for HF (HHF).

Results

From 230 patients, 65 patients with HFimpEF and 165 patients with Persistent HFrEF were analyzed. The median follow-up duration was 557 days (interquartile range 364 to 727 days). Patients with HFimpEF had a higher prevalence of female gender (50.8% vs. 30.3%) and de novo HF (44.6% vs. 21.2%). There were no significant differences for age, etiology (ischemic vs. non-ischemic), diabetes, atrial fibrillation, hypertension, and HF medications including SV dose between two groups. Patients with HFimpEF showed lower rate of all-cause death or HHF as a primary endpoint compared to patients with persistent HFrEF (6.2% vs. 22.4%; IPTW adjusted HR 0.24; 95% CI 0.13–0.46; p&lt;0.001) (Table 1). It was also shown that HFimpEF patients had a reduced risk of primary endpoint in the Kaplan-Meier curves compared with persistent HFrEF (Log-rank p=0.045) (Figure 1). We demonstrated that Non-prior MI (adjusted OR 7.29; 95% CI 1.50–35.36; p=0.014) and de novo HF (adjusted OR 4.33; 95% CI 1.70–11.04; p=0.002) were independent prognostic factors of HFimpEF in HFrEF patients treated with SV.

Conclusions

HFimpEF patients had better clinical outcomes compared to those with persistent HFrEF in HFrEF patients treated with SV. Non-prior MI and de novo HF were independent predictors of HFimpEF in patients treated with SV.

Funding Acknowledgement

Type of funding sources: None.

Expert commentary on the challenges and opportunities for surgical site infection prevention through implementation of evidence-based guidelines in the Asia-Pacific Region

INTRODUCTION

Surgical site infections (SSIs) are a significant source of morbidity and mortality in the Asia-Pacific region (APAC), adversely impacting patient quality of life, fiscal productivity and placing a major economic burden on the country's healthcare system. This commentary reports the findings of a two-day meeting that was held in Singapore on July 30-31, 2019, where a series of consensus recommendations were developed by an expert panel composed of infection control, surgical and quality experts from APAC nations in an effort to develop an evidence-based pathway to improving surgical patient outcomes in APAC.

METHODS

The expert panel conducted a literature review targeting four sentinel areas within the APAC region: national and societal guidelines, implementation strategies, postoperative surveillance and clinical outcomes. The panel formulated a series of key questions regarding APAC-specific challenges and opportunities for SSI prevention.

RESULTS

The expert panel identified several challenges for mitigating SSIs in APAC; (a) constraints on human resources, (b) lack of adequate policies and procedures, (c) lack of a strong safety culture, (d) limitation in funding resources, (e) environmental and geographic challenges, (f) cultural diversity, (g) poor patient awareness and (h) limitation in self-responsibility. Corrective strategies for guideline implementation in APAC were proposed that included: (a) institutional ownership of infection prevention strategies, (b) perform baseline assessments, (c) review evidence-based practices within the local context, (d) develop a plan for guideline implementation, (e) assess outcome and stakeholder feedback, and (f) ensure long-term sustainability.

CONCLUSIONS

Reducing the risk of SSIs in APAC region will require: (a) ongoing consultation and collaboration among stakeholders with a high level of clinical staff engagement and (b) a strong institutional and national commitment to alleviate the burden of SSIs by embracing a safety culture and accountability.

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

BACKGROUND

80% of individuals with cancer will require a surgical procedure, yet little comparative data exist on early outcomes in low-income and middle-income countries (LMICs). We compared postoperative outcomes in breast, colorectal, and gastric cancer surgery in hospitals worldwide, focusing on the effect of disease stage and complications on postoperative mortality.

METHODS

This was a multicentre, international prospective cohort study of consecutive adult patients undergoing surgery for primary breast, colorectal, or gastric cancer requiring a skin incision done under general or neuraxial anaesthesia. The primary outcome was death or major complication within 30 days of surgery. Multilevel logistic regression determined relationships within three-level nested models of patients within hospitals and countries. Hospital-level infrastructure effects were explored with three-way mediation analyses. This study was registered with ClinicalTrials.gov, NCT03471494.

FINDINGS

Between April 1, 2018, and Jan 31, 2019, we enrolled 15 958 patients from 428 hospitals in 82 countries (high income 9106 patients, 31 countries; upper-middle income 2721 patients, 23 countries; or lower-middle income 4131 patients, 28 countries). Patients in LMICs presented with more advanced disease compared with patients in high-income countries. 30-day mortality was higher for gastric cancer in low-income or lower-middle-income countries (adjusted odds ratio 3·72, 95% CI 1·70-8·16) and for colorectal cancer in low-income or lower-middle-income countries (4·59, 2·39-8·80) and upper-middle-income countries (2·06, 1·11-3·83). No difference in 30-day mortality was seen in breast cancer. The proportion of patients who died after a major complication was greatest in low-income or lower-middle-income countries (6·15, 3·26-11·59) and upper-middle-income countries (3·89, 2·08-7·29). Postoperative death after complications was partly explained by patient factors (60%) and partly by hospital or country (40%). The absence of consistently available postoperative care facilities was associated with seven to 10 more deaths per 100 major complications in LMICs. Cancer stage alone explained little of the early variation in mortality or postoperative complications.

INTERPRETATION

Higher levels of mortality after cancer surgery in LMICs was not fully explained by later presentation of disease. The capacity to rescue patients from surgical complications is a tangible opportunity for meaningful intervention. Early death after cancer surgery might be reduced by policies focusing on strengthening perioperative care systems to detect and intervene in common complications.

FUNDING

National Institute for Health Research Global Health Research Unit.

MON-LB85 Aberrant Glycan Expression Changes With the Phenotype of Follicular Thyroid Tumours

Glycosylation is the most common post‐translational modification of proteins and plays an important role in cell communication, interaction and adhesion. Aberration of glycosylation is a hallmark of cancer cells and plays an important role in oncogenesis and cancer progression including metastasis¹. One of the markers of aberrant glycosylation (O-linked) is the binding of the lectin Helix pomatia agglutinin (HPA), and this has been shown in a wide range of human cancers², especially in tumours with a more aggressive phenotype. To study the alteration in cellular glycosylation, detected by lectin Helix pomatia agglutinin (HPA) binding in various phenotypes of follicular thyroid tumours, ranging from adenoma to carcinoma and metastatic follicular thyroid cancers. Lectin histochemistry was performed on archival paraffin wax‐embedded specimens of 6 follicular adenomas, 10 minimally invasive follicular carcinomas, 13 widely invasive follicular cancers and 4 metastatic follicular thyroid cancers. For positive controls, sections of rat kidney were used, which shows strong and characteristic HPA labelling were included in each labelling experiment. For negative controls, the lectin was omitted and the specificity of binding was confirmed by incubating the sections with HPA in the presence of 0·1‐mol/l GalNAc. Sections were scored as positive when 5% or more of the cancer cells labelled positive and scored as negative when less than 5% labelled positive for HPA binding. Assessments of HPA binding were performed by two observers who were blinded to the identity of the sample, and their results were compared. Positive labelling was seen in 20% of adenomas, 60% of minimally invasive carcinomas, 77% of widely invasive carcinomas and 100% of metastatic carcinomas (p<0.05). In the minimally invasive carcinoma group, all tumours that showed vascular invasion showed positive HPA labelling, whereas only 20% of patients with capsular invasion showed positivity. We speculate that as the phenotype of the thyroid tumours changes from benign to the malignant phenotype, the glycan expressions change. However, the underlying molecular mechanisms leading to this change needs to be further investigated.

References:1. Magalhães, A., Duarte, H.O. & Reis, C.A. 2017, “Aberrant Glycosylation in Cancer: A Novel Molecular Mechanism Controlling Metastasis”, Cancer Cell, vol. 31, no. 6, pp. 733-735.2. Parameswaran, R., Sadler, G. & Brooks, S. 2011, “Helix pomatia Agglutinin Binding Glycoproteins in Thyroid Tumors”, World Journal of Surgery, vol. 35, no. 10, pp. 2219-2227.3.

Parameswaran, R., Tan, W.B., Nga, M.E., Soon, G.S.T., Ngiam, K.Y., Brooks, S.A., Sadler, G.P. & Mihai, R. 2018, “Binding of aberrant glycoproteins recognizable by Helix pomatia agglutinin in adrenal cancers”, BJS open, vol. 2, no. 5, pp. 353-359.

224 Malignancy associated pericardial effusion- do we need to drain them all?

On Behalf

Cardiac Team, Department of Medicine, Queen Elizabeth Hospital

Background

Management of significant pericardial effusion in cancer patients is controversial. These patients have poor prognosis, and avoiding unnecessary intervention is important. Close monitoring of symptoms and echocardiogram is often a reasonable option, but inherits risk of cardiac tamponade. Whether pericardial drainage by means of percutaneous pericardiocentesis or surgical pericardiotomy could prevent future deterioration or affect survival is unknown.

Purpose

To evaluate the benefit of elective pericardial drainage in malignancy associated pericardial effusion without echocardiographic or clinical evidence of tamponade effect.

Methods

From 1st Jul 2014 to 31st Dec 2017, all patients with new onset malignancy-associated pericardial effusion with size more than 1cm were retrospectively analyzed. Patients with clinical or echocardiographic evidence of cardiac tamponade were excluded. We compared pericardial drainage versus monitoring for short-term (30-day), mid-term (90-day) and long term (1 year) survival without need for drainage.

Results

101 patients were retrospectively analyzed. 40 (39.6%) patients underwent drainage. Overall median survival free from drainage was 4 months. There were no significant difference in short-term (30-day), mid-term (90-day) and long term (1-year) survival free from drainage or mortality between treatment and monitoring group. Size of pericardial effusion did not predict mortality or future need of drainage. Chemotherapy was associated with improved 30-day mortality (RR 0.53 CI 0.32-0.87 p = 0.025) but not survival free from drainage or longer term mortality.

Conclusion

Close monitoring could be a feasible strategy in cancer patients with significant pericardial effusion without tamponade effect.

Baseline characteristics Factor Drainage (n = 40) monitoring (n = 61) p-value method of drainage pericardiocentesis alone 17 NA pericardiotomy alone 13 both 10 Male 19 (47.5%) 27 (44.3%) 0.749 mean size (cm) 1.93 2.77 &lt;0.001 mean age 60.9 63.1 0.357 on chemotherapy 27 (67.5%) 38 (62.3%) 0.593

Abstract 224 Figure. Survival free from drainage

A 4-Year Audit of Open Method Chemoport Insertions through Cephalic Vein Performed In Hospital Tengku Ampuan Afzan

Introduction: Many cancer patients in general require long term venous access such as chemoport for chemotherapy, as well as infusion of fluids and blood taking. However, chemoport insertions carry complications such as infection, blockage, pneumothorax and malposition. We received feedbacks regarding complications endured by patients after chemoport insertion from the respective teams managing the patients in our hospital. In view of that, we conducted a retrospective audit on the chemoport insertions which we have done. Materials and Methods: We conducted a retrospective audit on the chemoport insertions which was planned for open method insertion through cephalic vein performed over the last 4 years from 2014 to 2017. Results: A total of 102 chemoports were inserted. Majority of patient’s ages are 50-59 years old. 88 (86%) of the cases were done via open method whereas another 14 cases were converted to percutaneous route. Majority of patients (55%) of the patients have breast carcinoma followed by colorectal (28%), haematological (12%) and gynaecological malignancies (5%). Complications occurred in 10 patients (rate at 9.8%). Most common complications were catheter related infection (5 cases) followed by wound infection (3 cases) and malposition (2 cases). Malposition was detected on post-operative chest radiograph and revision was done. All catheter related infection occurred in patients with haematological malignancies. Our complication rate of 9.8% is lower than the accepted complication rate of 15-25% worldwide. Conclusion: Chemoport provides a robust vascular access especially for the purpose of chemotherapy infusion. We showed with adequate training and privileging, it can be performed with very limited complications.

Evaluation of the blend of organic acids and medium-chain fatty acids in matrix coating as antibiotic growth promoter alternative on growth performance, nutrient digestibility, blood profiles, excreta microflora, and carcass quality in broilers

This study was conducted to evaluate the effects of the blend of organic acids (OAs) and medium-chain fatty acids (MCFAs) in broiler chickens. A total of 816 1-d-old male Ross 308 broiler chickens (35 ± 0.44 g) were randomly allocated into 1 of the following 6 dietary treatments (17 broilers per pen with 8 pens per treatment): dietary treatments consisted of corn-soybean meal-based basal diet and the basal diet supplemented with 0.02, 0.03, 0.04, 0.05, and 0.06% blend of OAs and MCFAs. The study lasted 5 wk during which growth performance was determined. In the current study, the inclusion of 0.02, 0.03, 0.04, 0.05, and 0.06% blend of OAs and MCFAs in the basal diet linearly increased (P < 0.05) body weight gain and improved feed conversion ratio (P < 0.0001) on day 7 to 14, day 14 to 35, as well as overall. Increasing inclusion of the blend of OAs and MCFAs levels in the diets also linearly increased (P = 0.001) the digestibility of dry matter on day 35. Broilers fed with different levels of the blend of OAs and MCFAs showed a linear increment (P = 0.042) in Lactobacillus concentration and decrease (P = 0.002) in Escherichia coli concentration. With regard to relative organ weight, a trend of linear reduction (P = 0.052) in bursa of Fabricius weight of broilers fed the blend of OAs and MCFAs was observed. There was a significant linear improvement (P = 0.011) in the IgG concentration associated with the inclusion of the blend of OAs and MCFAs levels in the diets. In conclusion, the blend of OAs and MCFAs supplementation positively influenced growth performance, nutrient digestibility, and excreta microflora in broiler chickens.

Modern-day palliative chemotherapy for metastatic colorectal cancer: does colonic resection affect survival?

BACKGROUND

Patients with metastatic colorectal cancer (mCRC) with surgically incurable metastases would be recommended for palliative chemotherapy (PC). The role of surgical intervention is debatable with no conclusive evidence for routine primary tumour resection (PTR) or stoma creation. We aimed to study if surgical intervention conferred a survival benefit in patients with mCRC who received upfront systemic therapy.

METHODS

A retrospective review of a prospectively collected database in a single centre was performed. Patients diagnosed with mCRC from January 2004 to December 2014 were included. We excluded patients who had an upfront surgical intervention, had no treatment with systemic therapy or had attained curative resection. The decision for surgery was based on the outcome of a multidisciplinary tumour board. Demographic, clinicopathological, treatment and follow-up data were collected. Univariate and multivariate analyses were performed.

RESULTS

Out of 408 patients with mCRC with incurable metastases, we analysed 124 patients who had upfront PC. Twenty-nine had PC + PTR (group A), 10 had PC + stoma (group B) and 85 had PC only (group C). Undergoing PTR led to significant improvement in overall survival (OS; 30.8 versus 13.4 versus 11.0 months, P < 0.001). With multivariate analysis, undergoing PTR and receiving biologics were independent good prognostic variables. Surgical resection was safe with minimal complications.

CONCLUSIONS

PTR was found to increase OS while stoma creation had no impact on OS. The benefits and safety of undergoing PTR may be a result of selection bias. Further prospective studies are required to confirm the observations of this study.

Performance, egg quality, nutrient digestibility, and excreta microbiota shedding in laying hens fed corn-soybean-meal-wheat-based diets supplemented with xylanase

The aim of this study was to evaluate the effects of dietary levels of xylanase on production performance, egg quality, nutrient digestibility, and excreta microbiota shedding of laying hens in a 12-week trial. Two-hundred-forty Hy-Line brown laying hens (44 wk old) were distributed according to a randomized block experimental design into one of 4 dietary treatments with 10 replicates of 6 birds each. The 4 dietary treatments were corn-soybean-meal-wheat-based diets supplemented with 0, 225, 450, or 900 U/kg xylanase. Daily feed intake, egg production, egg weight, egg mass, feed conversion ratio, and damaged egg rate showed no significant response to increasing xylanase supplementation during any phase (P > 0.05). No significant responses were observed for apparent total tract digestibility of dry matter, nitrogen, or gross energy (P > 0.05). A significant linear increase to increasing xylanase supplementation was seen for lactic acid bacteria numbers, although coliforms and Salmonella counts were not affected. Increasing the dietary xylanase resulted in a significant linear increase in eggshell thickness in wk 3, 6, 9, and 12 (P < 0.05). In addition, a significant linear increase occurred for Haugh unit and albumen height in wk 12 (P < 0.05). In summary, the inclusion of xylanase in corn-soybean-meal-wheat-based diets increased eggshell thickness, Haugh unit, albumen height, and excreta lactic acid bacteria count but had no effect on production performance or nutrient digestibility.

Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study

BACKGROUND

Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.

METHODS

This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.

FINDINGS

Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p<0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05-2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p<0·001).

INTERPRETATION

Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication.

FUNDING

DFID-MRC-Wellcome Trust Joint Global Health Trial Development Grant, National Institute of Health Research Global Health Research Unit Grant.

High resolution Thomson scattering system for steady-state linear plasma sources

The high resolution Thomson scattering system with 63 points along a 25 mm line measures the radial electron temperature (T_e) and its density (n_e) in an argon plasma. By using a DC arc source with lanthanum hexaboride (LaB₆) electrode, plasmas with electron temperature of over 5 eV and densities of 1.5 × 10¹⁹ m^-3 have been measured. The system uses a frequency doubled (532 nm) Nd:YAG laser with 0.25 J/pulse at 20 Hz. The scattered light is collected and sent to a triple-grating spectrometer via optical-fibers, where images are recorded by an intensified charge coupled device (ICCD) camera. Although excellent in stray-light reduction, a disadvantage comes with its relatively low optical transmission and in sampling a tiny scattering volume. Thus requires accumulating multitude of images. In order to improve photon statistics, pixel binning in the ICCD camera as well as enlarging the intermediate slit-width inside the triple-grating spectrometer has been exploited. In addition, the ICCD camera capture images at 40 Hz while the laser is at 20 Hz. This operation mode allows us to alternate between background and scattering shot images. By image subtraction, influences from the plasma background are effectively taken out. Maximum likelihood estimation that uses a parameter sweep finds best fitting parameters T_e and n_e with the incoherent scattering spectrum.

Metronome vs. Popular Song: A Comparison of Long-Term Retention of Chest Compression Skills after Layperson Training for Cardiopulmonary Resuscitation

Introduction

Long-term retention of cardiopulmonary resuscitation (CPR) skill is challenging for layperson trainees. This study compared the long-term retention of chest compression skills after either metronome-guided (MG) or popular song-guided (PG) CPR training.

Methods

This was a prospective randomised simulation trial. Untrained laypersons were randomly allocated to MG (n=61) or PG (n=68) groups at CPR training sessions. After CPR training, each participant performed 5-cycle CPR using a manikin with a Skill-Reporter™ immediately and six months afterwards.

Results

Immediately after training, the mean compression rate (MCR) was slightly higher in the PG than the MG group (107.4 vs. 102.2/min; p<0.0001), but there was no significant difference in the proportions of participants with an appropriate chest compression rate (100-120/min) (PSACCR) between the MG and PG (53/61 (86.9%) vs. 65/68 (95.6%); p=0.114). Six months later, MCR was faster in the MG than the PG (124.8 vs. 110.0/min; p<0.0001), and PSACCR in the PG was higher than that in the MG (62/68 (91.2%) vs. 25/61 (41.0%); p<0.0001). In both tests, there were no significant differences in other chest compression parameters of between the two groups, except for a minimal difference in incomplete chest release.

Conclusion

CPR training using a popular song is more effective than metronome-guided training in helping laypersons to maintain recommended compression rates after 6 months. (Hong Kong j.emerg.med. 2016;23:145-152)

Genome-wide loss-of-function genetic screening identifies opioid receptor μ1 as a key regulator of L-asparaginase resistance in pediatric acute lymphoblastic leukemia

L-asparaginase is a critical chemotherapeutic agent for acute lymphoblastic leukemia (ALL). It hydrolyzes plasma asparagine into aspartate and NH₃, causing asparagine deficit and inhibition of protein synthesis and eventually, leukemic cell death. However, patient relapse often occurs due to development of resistance. The molecular mechanism by which ALL cells acquire resistance to L-asparaginase is unknown. Therefore, we sought to identify genes that are involved in L-asparaginase resistance in primary leukemic cells. By unbiased genome-wide RNAi screening, we found that among 10 resistant ALL clones, six hits were for opioid receptor mu 1 (oprm1), two hits were for carbonic anhydrase 1 (ca1) and another two hits were for ubiquitin-conjugating enzyme E2C (ube2c). We also found that OPRM1 is expressed in all leukemic cells tested. Specific knockdown of OPRM1 confers L-asparaginase resistance, validating our genome-wide retroviral shRNA library screening data. Methadone, an agonist of OPRM1, enhances the sensitivity of parental leukemic cells, but not OPRM1-depleted cells, to L-asparaginase treatment, indicating that OPRM1 is required for the synergistic action of L-asparaginase and methadone, and that OPRM1 loss promotes leukemic cell survival likely through downregulation of the OPRM1-mediated apoptotic pathway. Consistent with this premise, patient leukemic cells with relatively high levels of OPRM1 are more sensitive to L-asparaginase treatment compared to OPRM1-depleted leukemic cells, further indicating that OPRM1 loss has a crucial role in L-asparaginase resistance in leukemic patients. Thus, our study demonstrates for the first time, a novel OPRM1-mediated mechanism for L-asparaginase resistance in ALL, and identifies OPRM1 as a functional biomarker for defining high-risk subpopulations and for the detection of evolving resistant clones. Oprm1 may also be utilized for effective treatment of L-asparaginase-resistant ALL.

Allogeneic adipose-derived stem cells for the treatment of perianal fistula in Crohn's disease: a pilot clinical trial

AIM

Many perianal fistulae in Crohn's disease do not respond to conventional surgical and medical management and recurrence rates are high. The study evaluated the safety and feasibility of allogeneic adipose-derived stem cells for the treatment of perianal fistula in Crohn's disease.

METHOD

A multicentre, open-label, dose escalation pilot study was performed. The first three patients (group 1) were administered 1 × 10(7) cells/ml based on the size of the fistula tract. Four weeks later, after which time this dose had been confirmed to be safe, the next three patients (group 2) were administered 3 × 10(7) cells/ml. The end-point was complete closure at 8 weeks after the injection. Patients who attended for the 8 week assessment were followed for an additional 6 months.

RESULTS

There were no adverse events of Grade 3 or 4 severity and no adverse events related to the treatment with allogeneic adipose-derived stem cells. Two patients in group 1 achieved complete closure of the fistula at month 4 and month 6, and one patient in group 2 achieved complete closure at 8 weeks. The closure was sustained up to month 8 in all three of those patients.

CONCLUSION

These data suggest that allogeneic adipose-derived stem cells may be a feasible treatment option for perianal fistula in Crohn's disease.

Outcomes of parathyroidectomy in renal hyperparathyroidism in patients with No access to renal transplantation in Singapore

BACKGROUND

Total parathyroidectomy with autotransplantation (TPTX + AT) and subtotal parathyroidectomy (SPTX) are considered standard surgical treatments for refractory renal hyperparathyroidism. However, there is little data available comparing their outcomes in an area with poor access to renal transplant and calcimimetics.

METHODS

Patients with renal hyperparathyroidism who underwent TPTX + AT and SPTX in a tertiary institution from 2006 to 2013 were studied. Patient characteristics, pre- and post-operative biochemical marker levels, and outcomes including recurrence rates, post-operative morbidity and mortality were analysed.

RESULTS

87 patients underwent parathyroidectomy for renal hyperthyroidism. Transplant patients were excluded in this study. 81 patients were on long-term dialysis, with a median time of 7 years from initiation of haemodialysis to parathyroidectomy. 57 patients (70.4%) underwent TPTX + AT while 24 (29.6%) underwent SPTX. Post-operatively, there was significant decrease in parathyroid hormone (PTH), calcium and phosphate levels in both groups. PTH and phosphate levels were significantly lowered with TPTX compared to SPTX (p = 0.004, 0.003). Symptomatic hypocalcaemia was seen in both groups. In a median follow-up of 4 years, 11 patients developed biochemical recurrence, with a median time of 29 months to recurrence. Median PTH at recurrence was 67.1 pmol/L. Rate of recurrence was higher in patients who underwent SPTX (20.8% vs 10.5%), with a shorter median time to recurrence (median 62.1 vs 81.3 months). 2 patients required resection of the autograft. Cohort mortality was 11 patients (13.4%), with 3 deaths secondary to cardiovascular events.

CONCLUSION

Total parathyroidectomy with autoimplantation is superior to subtotal parathyroidectomy in the short to intermediate term.

Multicentre study of robotic intersphincteric resection for low rectal cancer

BACKGROUND

There is a lack of information regarding the oncological safety of robotic intersphincteric resection (ISR) with coloanal anastomosis. The objective of this study was to compare the long-term feasibility of robotic compared with laparoscopic ISR.

METHODS

Between January 2008 and May 2011, consecutive patients who underwent robotic or laparoscopic ISR with coloanal anastomosis from seven institutions were included. Propensity score analyses were performed to compare outcomes for groups in a 1 : 1 case-matched cohort. The primary endpoint was 3-year disease-free survival.

RESULTS

A total of 334 patients underwent ISR with coloanal anastomosis, of whom 212 matched patients (106 in each group) formed the cohort for analysis. The overall rate of conversion to open surgery was 0.9 per cent in the robotic ISR group and 1.9 per cent in the laparoscopic ISR group. Nine patients (8.5 per cent) in the laparoscopic group and three (2.8 per cent) in the robotic ISR group still had a stoma at last follow-up (P = 0.075). Total mean hospital costs were significantly higher for robotic ISR (€ 12,757 versus € 9223 for laparoscopic ISR; P = 0.037). Overall 3-year local recurrence rates were similar in the two groups (6.7 per cent for robotic and 5.7 per cent for laparoscopic resection; P = 0.935). The combined 3-year disease-free survival rates were 89.6 (95 per cent c.i. 84.1 to 95.9) and 90.5 (85.4 to 96.6) per cent respectively (P = 0.298).

CONCLUSION

Robotic ISR with coloanal anastomosis for rectal cancer has reasonable oncological outcomes, but is currently too expensive with no short-term advantages.

Tumour volume changes assessed with high-quality KVCT in lung cancer patients undergoing concurrent chemoradiotherapy

OBJECTIVE

We evaluated tumour volume changes in patients with lung cancer undergoing concurrent chemoradiotherapy using image-guided radiotherapy (RT).

METHODS

The kilovoltage image was obtained using CT on rail at every five fractions. The gross tumour volumes (GTVs), including the primary tumour and lymph nodes (LNs), were contoured to analyse the time and degree of tumour regression.

RESULTS

46 patients [32, non-small-cell lung cancer (NSCLC), and 14, small-cell lung cancer (SCLC)] were included in this study. In total, 281 CT scans and 82 sites of GTVs were evaluated. Significant volume changes occurred in both the NSCLC and SCLC groups (p < 0.001 and 0.002), and the average GTV change compared with baseline was 49.85 ± 3.65 [standard error (SE)]% and 65.95 ± 4.60 (SE)% for the NSCLC and SCLC groups, respectively. A significant difference in the degree of volume reduction between the primary tumour and LNs was observed in only the NSCLC group (p < 0.0001) but not in the SCLC group (p = 0.735). The greatest volume regression compared with the volume before the five fractions occurred between the 15 and 20 fractions in the NSCLC group and between the 5 and 10 fractions in the SCLC group.

CONCLUSION

Both primary tumour and LNs were well defined using CT on rail. Significant volume changes occurred during RT, and there was a difference in volume reduction between the NSCLC and SCLC groups, regarding the degree and timing of the tumour reduction in the primary tumour and LNs.

ADVANCES IN KNOWLEDGE

NSCLC and SCLC groups showed differences in the degree and timing of volume reduction. The primary tumour and LNs in NSCLC regressed differently.

Management of acute ocular histoplasmosis syndrome

In summary, there are various factors which play an important prognostic role in the final visual acuity of patients with active histoplasma maculopathy. The factors over which we have no control is the location of the neovascular membrane in this maculopathy. The factors over which we do have control are how and when to treat it. We feel that laser photocoagulation is an effective method of treatment. It has been possible to obliterate the NVM as close as 200 micrometers from the foveola, thus preventing the development of subfoveal NVMs which have such a poor visual prognosis. The most important factor is the early treatment with laser photocoagulation. If we could treat all patients within 4 weeks of initial visual symptoms (group A), we might be able to eliminate a large number of patients (group C) who have a much poorer visual prognosis. Serial postoperative fluorescein studies are necessary to detect recurrent neovascular membranes which require further treatment.

Protected organic Acid blends as an alternative to antibiotics in finishing pigs

A total of 120 finishing pigs ([Yorkshire×Landrace]×Duroc) with an average body weight (BW) of 49.72 ±1.72 kg were used in 12-wk trial to evaluate the effects of protected organic acids on growth performance, nutrient digestibility, fecal micro flora, meat quality and fecal gas emission. Pigs were randomly allotted to one of three dietary treatments (10 replication pens with 4 pigs per pen) in a randomly complete block design based on their initial BW. Each dietary treatment consisted of: Control (CON/basal diet), OA1 (basal diet+0.1% organic acids) and OA2 (basal diet+0.2% organic acids). Dietary treatment with protected organic acid blends linearly improved (p<0.001) average daily gain during 0 to 6 week, 6 to 12 week as well as overall with the increase in their inclusion level in the diet. The dry matter, N, and energy digestibility was higher (linear effect, p<0.001) with the increase in the dose of protected organic acid blends during 12 week. During week 6, a decrease (linear effect, p = 0.01) in fecal ammonia contents was observed with the increase in the level of protected organic acid blends on d 3 and d 5 of fermentation. Moreover, acetic acid emission decreased linearly (p = 0.02) on d7 of fermentation with the increase in the level of protected organic acid blends. During 12 weeks, linear decrease (p<0.001) in fecal ammonia on d 3 and d 5 and acetic acid content on d 5 of fermentation was observed with the increase in the level of protected organic acid blends. Supplementation of protected organic acid blends linearly increased the longissimus muscle area with the increasing concentration of organic acids. Moreover, color of meat increased (linear effect, quadratic effect, p<0.001, p<0.002 respectively) and firmness of meat showed quadratic effect (p = 0.003) with the inclusion of increasing level of protected organic acid in the diet. During the 6 week, increment in the level of protected organic acid blends decreased (linear effect, p = 0.01) Escherichia coli (E. coli) counts and increased (linear effect, p = 0.004) Lactobacillus counts. During 12-wk of experimental trial, feces from pigs fed diet supplemented with organic acid blends showed linear reduction (p<0.001) of E. coli counts and the tendency of linear increase (p = 0.06) in Lactobacillus count with the increase in the level of organic acid blends. In conclusion, 0.2% protected organic acids blends positively affected growth performance, nutrient digestibility, fecal gas emission and meat quality in finishing pigs without any adverse effects on blood parameters.

Therapeutic advances: Single incision laparoscopic hepatopancreatobiliary surgery

Single-port laparoscopic surgery (SPLS) is proposed to be a step towards minimizing the invasiveness of surgery, and has since gained popularity in several surgical sub-specialties including hepatopancreatobiliary surgery. SPLS has since been applied to cholecystectomy, liver resection as well as pancreatectomy for a multitude of pathologies. Benefits of SPLS over conventional multi-incision laparoscopic surgery include improved cosmesis and potentially post-operative pain at specific time periods and extra-umbilical sites. However, it is also associated with longer operating time, increased rate of complications, and increased rate of port-site hernia. There is no significant difference between length of hospital stay. SPLS has a significant learning curve that affects operating time, rate of conversion and rate of complications. In this article, we review the literature on SPLS in hepatobiliary surgery - cholecystectomy, hepatectomy and pancreatectomy, and offer tips on overcoming potential technical obstacles and minimizing the complications when performing SPLS - surgeon position, position of port and instruments, instrument crossing position, standard hand grip vs reverse hand grip, snooker cue guide position, prevention of incisional hernia. SPLS is a promising direction in laparoscopic surgery, and we recommend step-wise progression of applications of SPLS to various hepatopancreatobiliary surgeries to ensure safe adoption of the surgical technique.

Effect of indigenous herbs on growth, blood metabolites and carcass characteristics in the late fattening period of hanwoo steers

This study was conducted to evaluate the effects of indigenous herbal supplements on growth, blood metabolites and carcass characteristics in the late fattening period of Hanwoo steers. In a 6 month feeding trial, thirty Hanwoo steers (647±32 kg) were allotted to one of 5 treatment groups, control (basal diet contained lasalocid), licorice, clove, turmeric and silymarin, with six steers per pen. All groups received ad libitum concentrate and 1 kg rice straw/animal/d throughout the feeding trial. Blood samples were collected at the beginning, middle, and the end of the experiment and the steers were slaughtered at the end. Blood glucose, triglyceride, total protein, and albumin concentrations were higher in the turmeric treatment compared with other treatments. Blood urea nitrogen and creatinine concentrations were highest (p<0.003 and p = 0.071, respectively) in steers treated with silymarin. Alanine aminotransferase activity was lower (p<0.06) for licorice and silymarin compared with the control group. There were no alterations in serum aspartate aminotransferase and gamma glutamyltransferase activities as a consequence of herb treatments (p = 0.203 and 0.135, respectively). Final body weight, body weight gain, average dairy gain and dry matter intake were not significantly different among treatments. Yield grade, marbling score and quality grade were higher for silymarin group than those of the control group (p<0.05). Therefore, the results suggest that silymarin can be used an effective dietary supplement as an alternative to antibiotic feed additive and a productivity enhancer, providing safe and more consumer acceptable alternative to synthetic compounds during the late fattening period of steers.

Accuracy of lung nodule volumetry in low-dose CT with iterative reconstruction: an anthropomorphic thoracic phantom study

OBJECTIVE

The purpose of this study was to assess accuracy of lung nodule volumetry in low-dose CT with application of iterative reconstruction (IR) according to nodule size, nodule density and CT tube currents, using artificial lung nodules within an anthropomorphic thoracic phantom.

METHODS

Eight artificial nodules (four diameters: 5, 8, 10 and 12 mm; two CT densities: -630 HU that represents ground-glass nodule and +100 HU that represents solid nodule) were randomly placed inside a thoracic phantom. Scans were performed with tube current-time product to 10, 20, 30 and 50 mAs. Images were reconstructed with IR and filtered back projection (FBP). We compared volume estimates to a reference standard and calculated the absolute percentage error (APE).

RESULTS

The APE of all nodules was significantly lower when IR was used than with FBP (7.5 ± 4.7% compared with 9.0 ±6.9%; p < 0.001). The effect of IR was more pronounced for smaller nodules (p < 0.001). IR showed a significantly lower APE than FBP in ground-glass nodules (p < 0.0001), and the difference was more pronounced at the lowest tube current (11.8 ± 5.9% compared with 21.3 ± 6.1%; p < 0.0001). The effect of IR was most pronounced for ground-glass nodules in the lowest CT tube current.

CONCLUSION

Lung nodule volumetry in low-dose CT by application of IR showed reliable accuracy in a phantom study. Lung nodule volumetry can be reliably applicable to all lung nodules including small, ground-glass nodules even in ultra-low-dose CT with application of IR.

ADVANCES IN KNOWLEDGE

IR significantly improved the accuracy of lung nodule volumetry compared with FBP particularly for ground-glass (-630 HU) nodules. Volumetry in low-dose CT can be utilized in patient with lung nodule work-up, and IR has benefit for small, ground-glass lung nodules in low-dose CT.

Biosorption of uranium(VI) from aqueous solution by biomass of brown algae Laminaria japonica

The uranium(VI) adsorption efficiency of non-living biomass of brown algae was evaluated in various adsorption experimental conditions. Several different sizes of biomass were prepared using pretreatment and surface-modification steps. The kinetics of uranium uptake were mainly dependent on the particle size of the prepared Laminaria japonica biosorbent. The optimal particle size, contact time, and injection amount for the stable operation of the wastewater treatment process were determined. Spectroscopic analyses showed that uranium was adsorbed in the porous inside structure of the biosorbent. The ionic diffusivity in the biomass was the dominant rate-limiting factor; therefore, the adsorption rate was significantly increased with decrease of particle size. From the results of comparative experiments using the biosorbents and other chemical adsorbents/precipitants, such as activated carbons, zeolites, and limes, it was demonstrated that the brown algae biosorbent could replace the conventional chemicals for uranium removal. As a post-treatment for the final solid waste reduction, the ignition treatment could significantly reduce the weight of waste biosorbents. In conclusion, the brown algae biosorbent is shown to be a favorable adsorbent for uranium(VI) removal from radioactive wastewater.

Blood-brain barrier disruption after cardiac surgery

BACKGROUND AND PURPOSE

CNS complications are often seen after heart surgery, and postsurgical disruption of the BBB may play an etiologic role. The objective of this study was to determine the prevalence of MR imaging-detected BBB disruption (HARM) and DWI lesions after cardiac surgery.

MATERIALS AND METHODS

All patients had an MRI after cardiac surgery. For half the patients (group 1), we administered gadolinium 24 hours after surgery and obtained high-resolution DWI and FLAIR images 24-48 hours later. We administered gadolinium to the other half (group 2) at the time of the postoperative scan, 2-4 days after surgery. Two stroke neurologists evaluated the images.

RESULTS

Of the 19 patients we studied, none had clinical evidence of a stroke or delirium at the time of the gadolinium administration or the scan, but 9 patients (47%) had HARM (67% in group 1; 30% in group 2; P = .18) and 14 patients (74%) had DWI lesions (70% in group 1; 78% in group 2; P = 1.0). Not all patients with DWI lesions had HARM, and not all patients with HARM had DWI lesions (P = .56).

CONCLUSIONS

Almost half the patients undergoing cardiac surgery have evidence of HARM, and three-quarters have acute lesions on DWI after surgery. BBB disruption is more prevalent in the first 24 hours after surgery. These findings suggest that MR imaging can be used as an imaging biomarker to assess therapies that may protect the BBB in patients undergoing heart surgery.

Endothelin-1 enhances the proliferation of normal human melanocytes in a paradoxical manner from the TNF-α-inhibited condition, but tacrolimus promotes exclusively the cellular migration without proliferation: a proposed action mechanism for combination therapy of phototherapy and topical tacrolimus in vitiligo treatment

BACKGROUND

Vitiligo is an acquired pigmentary disorder caused by the destruction of melanocytes. Two of the major theories regarding the pathogenesis of vitiligo are the autoimmune theory and autocytotoxicity theory, but, the precise pathogenetic mechanism is still not clarified.

OBJECTIVES

We investigated the effects of ET-1, tacrolimus and tumour necrosis factor-α (TNF-α) on proliferation and migration of cultured normal human melanocytes (NHMs). We also sought to clarify the theoretical rationale underlying the topical tacrolimus monotherapy or tacrolimus-UV combination therapy as tools for vitiligo treatment.

METHODS

The effects of ET-1, tacrolimus and TNF-α on proliferation/migration of cultured NHMs were investigated by MTT assay/Boyden chamber transwell migration assay. We also examined roles of CXC-chemokine receptor II (CXCR II) and matrix metalloproteinases (MMPs) in such conditions.

RESULTS

ET-1 exerted a stimulatory effect on melanocyte proliferation and migration, but, tacrolimus exerted a stimulatory effect only on melanocyte migration higher than ET-1. TNF-α inhibited melanocyte proliferation in a dose-dependent manner. Paradoxically, TNF-α-pretreated NHMs exhibited an enhanced proliferative efficiency after being switched to ET-1. We found CXCRII was highly expressed in TNF-α-incubated melanocytes than the agents-free control, and ET-1 treatment after TNF-α preincubation showed the higher levels of CXCRII expression than the condition incubated with TNF-α alone. Moreover, the greater activities of MMP-2 and MMP-9 induced by tacrolimus than ET-1, reflected tacrolimus would enhance migration stimulatory effect in cultured NHMs.

CONCLUSIONS

Topical tacrolimus can be used an effective agent for vitiligo treatment as monotherapy, maybe due to its migration stimulatory action or TNF-α inhibitory property, and also as a component in combination therapy with UV treatment, considering the more upregulated MMPs activities are induced and the more effective migrations are feasible by itself than ET-1.

Upregulation of high-affinity GABA(A) receptors in cultured rat dorsal root ganglion neurons

Despite evidence that high-affinity GABA(A) receptor subunit mRNA and protein are present in dorsal root ganglia (DRG), low-affinity currents dominate those detected in acutely dissociated DRG neurons in vitro. This observation raises the possibility that high-affinity receptors are normally trafficked out of the DRG toward central and peripheral terminals. We therefore hypothesized that with time in culture, there would be an increase in high-affinity GABA(A) currents in DRG neurons. To test this hypothesis, we studied dissociated DRG neurons 2 h (acute) and 24 h (cultured) after plating with whole-cell patch-clamp techniques, Western blot, and semiquantitative reverse transcriptase polymerase chain reaction (sqRT-PCR) analysis. GABA(A) current density increases dramatically with time in culture in association with the emergence of two persistent currents with EC50's of 0.25±0.01 μM and 3.2±0.02 μM for GABA activation. In a subpopulation of neurons, there was also an increase in the potency of GABA activation of the transient current from an EC50 of 78.16±10.1 μM to 9.56±1.3 μM with time in culture. A fraction of the high-affinity current was potentiated by δ-subunit agonist 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridine-3-ol (THIP). δ-subunit immunoreactivity was largely restricted to the cytosolic fraction in acute, but the membrane fraction in cultured, DRG neurons, with no detectable change in δ-subunit mRNA. However, the emergence of a high-affinity current blocked by THIP and insensitive to bicuculline was detected in a subpopulation of cultured neurons as well in association with an increase in ρ2- and ρ3-subunit mRNA in cultured DRG neurons. Our results suggest that high-affinity δ-subunit-containing GABA(A) receptors are normally trafficked out of the DRG where they are targeted to peripheral and central processes. They also highlight that the interpretation of data obtained from cultured DRG neurons should be made with caution.

Adenosine triphosphate-based chemotherapy response assay-guided chemotherapy in unresectable colorectal liver metastasis

BACKGROUND

This study aims to evaluate the effectiveness of adenosine triphosphate-based chemotherapy response assay (ATP-CRA)-guided neoadjuvant chemotherapy for increasing resectability in patients with unresectable colorectal liver metastasis.

PATIENTS AND METHODS

Patients were randomised into two groups: Group A was treated by conventional chemotherapy regimen and Group B was treated by chemotherapy regimen according to the ATP-CRA. Three chemotherapeutic agents (5-fluorouracil, oxaliplatin and irinotecan) were tested by ATP-CRA and more sensitive agents were selected. Either FOLFOX or FOLFIRI was administered. Between Group A and B, treatment response and resectability were compared.

RESULTS

Between November 2008 and October 2010, a total 63 patients were randomised to Group A (N=32) or Group B (N=31). FOLFOX was more preferred in Group A than in Group B (26 out of 32 (81.3%) vs 20 out of 31 (64.5%)). Group B showed better treatment response than Group A (48.4% vs 21.9%, P=0.027). The resectability of hepatic lesion was higher in Group B (35.5% vs 12.5%, P=0.032). Mean duration from chemotherapy onset to the time of liver resection was 11 cycles (range 4-12) in Group A and 8 cycles (range 8-16) in Group B.

CONCLUSION

This study showed that tailored-chemotherapy based on ATP-CRA could improve the treatment response and resectability in initially unresectable colorectal liver metastasis.

Time-resolved measurements of PM2.5 carbonaceous aerosols at Gosan, Korea

In order to better understand the characteristics of atmospheric carbonaceous aerosol at a background site in Northeast Asia, semicontinuous organic carbon (OC) and elemental carbon (EC), and time-resolved water-soluble organic carbon (WSOC) were measured by a Sunset OC/ EC and a PILS-TOC (particle-into-liquid sampler coupled with an online total organic carbon) analyzer, respectively, at the Gosan supersite on Jeju Island, Korea, in the summer (May 28-June 17) and fall (August 24-September 30) of 2009. Hourly average OC concentration varied in the range of approximately 0.87-28.38 microgC m-3, with a mean of 4.07+/- 2.60 microgC m-3, while the hourly average EC concentration ranged approximately from 0.04 to 8.19 .microgC m-3, with a mean of 1.35 +/- 0.71 microgC m-3, from May 28 to June 17, 2009. During the fall season, OC varied in the approximate range 0.9-9.6 microgC m-3, with a mean of 2.30 +/-0.80 microgC m-3, whereas EC ranged approximately from 0.01 to 5.40 microgC m-3, with a mean of 0.66 +/- 0.38 microgC m-3. Average contributions of EC to TC and WSOC to OC were 26.0% +/- 9.7% and 20.6% +/-7.4%, and 37.6% +/- 23.5% and 57.2% +/- 22.2% during summer and fall seasons, respectively. As expected, clear diurnal variation of WSOC/OC was found in summer, varying from 0.22 during the nighttime up to 0.72 during the daytime, mainly due to the photo-oxidation process. In order to investigate the effect of air mass pathway on the characteristics of carbonaceous aerosol, 5-day back-trajectory analysis was conducted using the HYSPLIT model. The air mass pathways were classified into four types: Continental (CC), Marine (M), East Sea (ES) and Korean Peninsula (KP). The highest OC/EC ratio of 3.63 was observed when air mass originated from the Continental area (CC). The lowest OC/EC ratio of 0.79 was measured when air mass originated from the Marine area (M). A high OC concentration was occasionally observed at Gosan due to local biomass burning activities. The contribution of secondary OC to total OC varied approximately between 8.4% and 32.2% and depended on air mass type.

Transanal specimen extraction in robotic rectal cancer surgery

BACKGROUND

The aim of this study was to identify the benefits of robotic transanal specimen extraction (RTSE) compared with minilaparotomy specimen extraction (MSE).

METHODS

Patients who underwent totally robotic surgery with curative intent for treatment of adenocarcinoma of the rectum below 12 cm from the anal verge were selected from the authors' database. Patients were divided into RTSE and MSE groups according to the method of specimen delivery. Clinicopathological features and perioperative surgical outcomes were compared between the two groups.

RESULTS

There were 53 patients in the RTSE group and 66 in the MSE group. No differences were observed in overall complications. Postoperative recovery was faster in the RTSE group in terms of resumption of a soft diet (mean(s.d.) 3·5(1·5) versus 4·6(1·7) days; P < 0·001) and length of hospital stay (9·0(4·8) versus 11·3(5·3) days; P = 0·016). Pain scores on a visual analogue scale were significantly lower in the RTSE group than in the MSE group from day 2 to day 5 after surgery (P = 0·021 to P < 0·001).

CONCLUSION

RTSE in robotic rectal cancer surgery was associated with less pain and a faster recovery than MSE.

Preparation and characterization of iridium dioxide-carbon nanotube nanocomposites for supercapacitors

A thin film of novel hierarchical structure, suitable for supercapacitor applications, has been developed through combining conductive multi-wall carbon nanotubes (MWCNTs) and square IrO(2) nanotubes (IrO(2)NT) of nanometer size. Synthesis of this hierarchical structure with open porosity is performed by depositing IrO(2) short tubes densely along the long wires of carbon nanotube on a substrate of stainless steel. A IrO(2) tube of rutile structure grows in the [001] direction, with an opening at its top, surrounded by very thin walls. The IrO(2) addition on the MWCNT template increases the capacitance of the CNT thin film effectively, because of pseudocapacitance of the IrO(2) surface. For this particular composite, featured with two tubular nanostructures, the specific capacitance increases from 15 F g(-1) (MWCNT) to 69 F g(-1) (IrO(2)NT/MWCNT), measured using the galvanostatic discharge experiment. Its property of fast retrieval of the stored charge is assured in the impedance measurement, showing that the internal resistance of the IrO(2)NT/MWCNT nanocomposite electrode is lower than that of the bare MWCNTs.

CT characteristics of a uterus-like mass in the sigmoid mesocolon

A uterus-like mass is a rare, benign extra-uterine tumour composed of smooth muscle and endometrium. The majority of uterus-like masses occur in the ovary. Rarely, uterus-like masses occur in the broad ligament, small bowel, small bowel mesentery or uterine cervix. Here, we report a case of a uterus-like mass in the sigmoid mesocolon. A well-defined, markedly enhanced soft-tissue mass with central cystic change and haemorrhage was observed on CT. The current report describes the CT characteristics of this sigmoid mesocolon uterus-like mass together with the differential diagnoses.

Light extraction efficiency enhancement of GaN-based light emitting diodes on n-GaN layer using a SiO2 photonic quasi-crystal overgrowth

In this paper, GaN-based LEDs with a SiO2 photonic quasi-crystal (PQC) pattern on an n-GaN layer by nano-imprint lithography (NIL) are fabricated and investigated. At a driving current of 20 mA on Transistor Outline (TO)-can package, the better light output power of LED III (d = 1.2 microm) was enhanced by a factor of 1.20. After 1000 h life test (55 degrees C/50 mA) condition, Normalized output power of LED with a SiO2 PQC pattern (LED III (d = 1.2 microm)) on an n-GaN layer only decreased by 5%. This results offer promising potential to enhance the light output power of commercial light-emitting devices using the technique of nano-imprint lithography.

Increased incidence of colorectal malignancies in renal transplant recipients: a case control study

This study was to evaluate the frequency of colorectal neoplasia in renal transplant recipients and to investigate the association with Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infection. We compared the frequency of colorectal neoplasia among renal transplant recipients with that of the healthy subjects. Specimens of colorectal neoplasia were examined for EBV and CMV using in situ hybridization and immunohistochemistry, respectively. Of 796 renal transplantation cohorts, 315 were enrolled. The frequency of colorectal neoplasia among the patients was 22.9%. Compared with the healthy subjects, the odds ratio (OR) for advanced adenoma was 3.32 (95% CI, 1.81-6.10). The frequency of cancer among the patients was 1.9% (OR, 12.0; 95% CI, 1.45-99.7). A long interval between transplantation and colonoscopy was a significant factor in the development of advanced colorectal neoplasia. EBV positivity was detected in 30.6% of colorectal neoplasia specimens from renal transplant recipients, which was higher than that for the controls (p = 0.002). CMV was not detected in any lesions of patients or controls. In conclusion, renal transplant recipients have a significantly increased risk of advanced colorectal neoplasia. EBV was more frequently found in specimens of advanced colorectal neoplasm obtained from the renal transplant recipients.

Wear performance of self-mating contact pairs of TiN and TiAlN coatings on orthopedic grade Ti-6Al-4V

Both titanium nitride (TiN) and titanium aluminum nitride (TiAlN) have shown great wear resistance potential in metallic medical devices as protective, hard thin film coatings. In the present study, the effects of TiN and TiAlN coating layers on the wear performance of Ti-6Al-4V were compared and analyzed. TiN and TiAlN coatings with a thickness of 3 microm were deposited by a cathodic vacuum arc ion plating technique on the surface of Ti-6Al-4V. Wear tests were conducted by using a pin-on-disk-type tribotester with a point contact self-mating pair in a linear reciprocal motion. A sliding distance of 20 mm per cycle at 1 Hz was used under a load of 15 N under ambient conditions with no lubricant. The wear resistance of TiN and TiAlN coatings is superior to that of uncoated Ti-6Al-4V at the early stage of sliding contact. Until a measurable amount of wear was detected, the number of sliding cycles of the TiAlN coating pair was longer than TiN. After the first detection of wear from the coating layers, the rate of wear of the TiN coating pairs was significantly higher than that of TiAlN (p < 0.05), and it was close to that of the uncoated pairs. In conclusion, the TiAlN coating is superior to TiN from the viewpoint of wear resistance under the test conditions used in this study.

Use of human amniotic membrane wrap in reducing perineural adhesions in a rabbit model of ulnar nerve neurorrhaphy

The object of this experimental study was to assess the effect of wrapping human amniotic membrane around a repaired ulnar nerve in a rabbit model of perineural adhesion. Ulnar nerves from 10 white New Zealand rabbits were exposed bilaterally, dissected and repaired. Human amniotic membrane was then wrapped around the repair site in one limb with no such wrap in the neurorrhaphy of the contralateral limb. Three months later, the same nerves were re-explored and removed using microsurgical external neurolysis. Perineural adhesion around the ulnar nerve was evaluated by blinded surgical dissection and scored using a visual 4-point qualitative scale. Extent and grade of fibrosis around repair sites were measured microscopically (x 200) after Masson trichrome staining using measure of the depth of fibrosis and the grading criteria of adhesion. Quantitative morphometric analysis was also performed under light microscopy (x 200) with the aid of a digital counter and virtual slide imaging software (ScanScope T2, Vista, CA, USA). Human amniotic membrane wrapped nerves showed significantly less perineural adhesion and fibrosis than controls (P < 0.05). No nerve healing problems were encountered. This study suggests that human amniotic membrane application can reduce fibrosis and adhesion around neurorrhaphy sites in this animal model.

Characterization and enhanced field emission properties of IrO2-coated carbon nanotube bundle arrays

Low operating electric field and stable emission current have been achieved in IrO(2) nanocrystal-coated carbon nanotube bundle arrays (CNTBAs). Patterned vertically aligned CNTBAs were synthesized using thermal chemical vapor deposition followed by the deposition of IrO(2) nanocrystals by reactive radio-frequency magnetron sputtering using an Ir target. The structural and spectroscopic properties were characterized by field emission scanning and transmission electron microscopy, and Raman spectroscopy. The current density versus electric field measurements yielded a low turn-on field of 0.7 V microm(-1) at a current density of 0.1 microA cm(-2), a low threshold field of 2.3 V microm(-1) at a current density of 1 mA cm(-2) and a high field enhancement factor of 1 x 10(4) for the IrO(2)-coated CNTBAs. Long-term stability was also demonstrated. The enhancement of field emission characteristics is attributed to the combined effects of the geometrical structure of the IrO(2)-coated CNTBAs, and the natural conducting and enhanced resistance to oxidation properties of IrO(2).

Case report: Imaging features of perianal leiomyoma

A leiomyoma is a benign mesenchymal neoplasm that usually develops where smooth muscle is present. In this report, we present a rare case of perianal leiomyoma. The external anal sphincter was stretched over the surface of the leiomyoma and the internal anal sphincter was intact on surgery. It was confirmed as a deep soft-tissue leiomyoma on pathology. We describe the ultrasonographic and MRI findings of a rare case of perianal leiomyoma, together with differential diagnoses.

Distal hyperintense vessels on FLAIR: an MRI marker for collateral circulation in acute stroke?

BACKGROUND

Hyperintense vessels (HV) on fluid-attenuated inversion recovery imaging are frequently observed in acute ischemic stroke patients. However, the exact mechanism and clinical implications of this sign have not yet been clearly defined. The features of HV and its relevance to other imaging factors are presented here.

METHODS

Prominence and location of HV were documented in 52 consecutive patients with middle cerebral artery (MCA) territory infarction, before treatment with IV recombinant tissue plasminogen activator. Pretreatment ischemic lesion volume, perfusion lesion volume, and vessel occlusion were determined in addition to recanalization status and ischemic lesion volume on follow-up imaging. NIH Stroke Scale (NIHSS) was used as a measure of clinical severity.

RESULTS

HV distal to arterial occlusion was observed in 73% of patients; more frequent in proximal than distal MCA occlusion patients. Among the 38 patients with proximal MCA occlusion, initial perfusion lesion volume was comparable among patients with different grade distal HV. However, patients with more prominent distal HV had smaller initial, 24-hour, and subacute ischemic lesion volumes and lower initial NIHSS scores.

CONCLUSIONS

The presence of distal hyperintense vessels before thrombolytic treatment is associated with large diffusion-perfusion mismatch and smaller subacute ischemic lesion volumes in patients with proximal middle cerebral artery occlusion. DWI = diffusion-weighted imaging; FLAIR = fluid-attenuated inversion recovery; GRE = gradient recalled echo; HV = hyperintense vessels; MCA = middle cerebral artery; MRA = magnetic resonance angiography; MTT = mean transit time; NIHSS = NIH Stroke Scale; PWI = perfusion-weighted imaging; rt-PA = recombinant tissue plasminogen activator; TE = echo time; TI = inversion time; TIMI = thrombolysis in myocardial infarction; TR = repetition time.

Molecular analysis of the GJB2, GJB6 and SLC26A4 genes in Korean deafness patients

OBJECTIVES

Mutations in the GJB2, GJB6 and SLC26A4 genes are a frequent cause of hearing loss in a number of populations. However, little is known about the genetic causes of hearing loss in the Korean population.

METHODS

We sequenced the GJB2 and GJB6 genes to examine the role of mutations in these genes in 22 hearing loss patients. We also sequenced the SLC26A4 gene in seven patients with inner ear malformations, including enlarged vestibular aqueduct (EVA) revealed by computer tomography.

RESULTS

Coding sequence mutations in GJB2 were identified in 13.6% of the patients screened. Two different mutations, 235delC and T86R were found in three unrelated patients. The 235delC was the most prevalent mutation with an allele frequency of 6.9% in our patient group. No mutations, including 342-kb deletion, were found in GJB6 gene. Three different variants of SLC26A4 were identified in the EVA patients, including one novel mutation. Four EVA patients carried two mutant alleles of SLC26A4, and at least one allele in all patients was the H723R mutation, which accounted for 75% of all mutant alleles.

CONCLUSIONS

Our results suggest that GJB2 and SLC26A4 mutations together make up a major cause of congenital hearing loss in the Korean population. Further studies may be able to identify other common variants that account for a significant fraction of hearing loss in the Korean population.