Amorphous Thickness-Dependent Strengthening-Softening Transition in Crystalline-Amorphous Nanocomposites

Core-shell crystalline-amorphous nanocomposites, featuring nanograins surrounded by thick amorphous boundaries, are promising nanoarchitectures for achieving exceptional strength through cooperative strengthening effects. However, a comprehensive understanding of the influence of characteristic sizes, particularly the amorphous thickness, on codeformation strengthening is still lacking, limiting the attainment of the strength limit. Here, we employ molecular dynamics simulations to investigate Cu-CuTa crystalline-amorphous nanocomposites with varying grain sizes and amorphous thicknesses. Our findings demonstrate significant strengthening effects in nanocomposites, effectively suppressing the Hall-Petch breakdown observed in traditional amorphous-free nanograined Cu. Intriguingly, we observe a maximum strength followed by a strengthening-softening transition dependent on the amorphous thickness, as exemplified by a representative nanocomposite featuring a 12.5 nm grain size and a critical amorphous thickness of 4 nm. Inspired by observed shifts in atomistic mechanisms, we developed a theoretical model encompassing variations in grain size and amorphous thickness, providing valuable insights into the size-strength relationship for crystalline-amorphous nanocomposites.

Boosting Oxygen-Evolving Activity via Atom-Stepped Interfaces Architected with Kinetic Frustration

A highly active interface is extremely critical for the catalytic efficiency of an electrocatalyst; however, facilely tailoring its atomic packing characteristics remains challenging. Herein, a simple yet effective strategy is reported to obtain copious high-energy atomic steps at the interface via controlling the solidification behavior of glass-forming metallic liquids. By adjusting the chemical composition and cooling rate, highly faceted FeNi₃ nanocrystals are in situ formed in an FeNiB metallic glass (MG) matrix, leading to the creation of order/disorder interfaces. Benefiting from the catalytically active and stable atomic steps at the jagged interfaces, the resultant free-standing FeNi₃ nanocrystal/MG composite exhibits a low oxygen-evolving overpotential of 214 mV at 10 mA cm^-2 , a small Tafel slope of 32.4 mV dec^-1 , and good stability in alkaline media, outperforming most state-of-the-art catalysts. This approach is based on the manipulation of nucleation and crystal growth of the solid-solution nanophases (e.g., FeNi₃ ) in glass-forming liquids, so that the highly stepped interface architecture can be obtained due to the kinetic frustration effect in MGs upon undercooling. It is envisaged that the atomic-level stepped interface engineering via the physical metallurgy method can be easily extended to other MG systems, providing a new and generic paradigm for designing efficient yet cost-effective electrocatalysts.

Infection control measures for public transportation derived from the flow dynamics of obstructed cough jet

During the COVID-19 pandemic, WHO and CDC suggest people stay 1 m and 1.8 m away from others, respectively. Keeping social distance can avoid close contact and mitigate infection spread. Many researchers suspect that suggested distances are not enough because aerosols can spread up to 7-8 m away. Despite the debate on social distance, these social distances rely on unobstructed respiratory activities such as coughing and sneezing. Differently, in this work, we focused on the most common but less studied aerosol spread from an obstructed cough. The flow dynamics of a cough jet blocked by the backrest and gasper jet in a cabin environment was characterized by the particle image velocimetry (PIV) technique. It was proved that the backrest and the gasper jet can prevent the front passenger from droplet spray in public transportation where maintaining social distance was difficult. A model was developed to describe the cough jet trajectory due to the gasper jet, which matched well with PIV results. It was found that buoyancy and inside droplets almost do not affect the short-range cough jet trajectory. Infection control measures were suggested for public transportation, including using backrest/gasper jet, installing localized exhaust, and surface cleaning of the backrest.

Health Services Use and Functional Recovery Following Blunt Trauma in Older Persons - A National Multicentre Prospective Cohort Study

OBJECTIVE

Frailty is associated with morbidity and mortality in older injured patients. However, for older blunt-trauma patients, increased frailty may not manifest in longer length of stay at index admission. We hypothesized that owing to time spent in hospital from readmissions, frailty would be associated with less total time at home in the 1-year postinjury period.

DESIGN

Prospective, nationwide, multicenter cohort study.

SETTING AND PARTICIPANTS

All Singaporean residents aged ≥55 years admitted for blunt trauma with an Injury Severity Score (ISS) or New Injury Severity Score (NISS) ≥10 from March 2016 to July 2018.

METHODS

Frailty (by modified Fried criteria) was assessed at index admission, based on questions on preinjury weight loss, slowness, exhaustion, physical activity, and grip strength at the time of recruitment. Low time at home was defined as >14 hospitalized days within 1 year postinjury. The contribution of planned and unplanned readmission to time at home postinjury was explored. Functional trajectory (by Barthel Index) over 1 year was compared by frailty.

RESULTS

Of the 218 patients recruited, 125 (57.3%) were male, median age was 72 years, and 48 (22.0%) were frail. On univariate analysis, frailty [relative to nonfrail: odds ratio (OR) 3.45, 95% confidence interval (CI) 1.33-8.97, P = .01] was associated with low time at home. On multivariable analysis, after inclusion of age, gender, ISS, intensive care unit admission, and surgery at index admission, frailty (OR 5.21, 95% CI 1.77-15.34, P < .01) remained significantly associated with low time at home in the 1-year postinjury period. Unplanned readmissions were the main reason for frail participants having low time at home. Frail participants had poorer function in the 1-year postinjury period.

CONCLUSIONS AND IMPLICATIONS

In the year following blunt trauma, frail older patients experience lower time at home compared to patients who were not frail at baseline. Screening for frailty should be considered in all older blunt-trauma patients, with a view to being prioritized for postdischarge support.

Hopes and Wishes of Clients with Mentally Illness in Hong Kong

Recovery is a progressive process involving support to people with mental illness to take control of their life through the enhancement of motivation, self-drive, and responsibility. Drawing on qualitative interviews with 61 patients with mental illness aged between 40 and 75 in the community or residential settings, this study examined the wishes and hopes of clients who were in recovery. Participants described wishes and hopes for autonomy and independence in finances, accommodation, and health; stable housing or accommodation; meaningful occupation or employment; 'giving back' to society by serving others; intimate relationships; and gaining back 'lost time.' Wishes and hopes were motivating factors contributing to physical, mental, and social health over time, motivating clients with mental illness to live happily. To foster recovery, mental health practitioners should consider the identification and fulfilment of wishes and hopes in health and social care programs for this unique client group.

Singapore Advanced Cardiac Life Support Guidelines 2021

Advanced cardiac life support (ACLS) emphasises the use of advanced airway management and ventilation, circulatory support and the appropriate use of drugs in resuscitation, as well as the identification of reversible causes of cardiac arrest. Extracorporeal cardiopulmonary resuscitation and organ donation, as well as special circumstances including drowning, pulmonary embolism and pregnancy are addressed. Resuscitation does not end with ACLS but must continue in post-resuscitation care. ACLS also covers the recognition and management of unstable pre-arrest tachy- and bradydysrhythmias that may deteriorate further.

The experience of growing old in chronic mental health patients

Objectives: Research evidence has demonstrated disparities and barriers associated with mental illness, which creates challenges for individuals with mental illness to maintain physical, mental, and social health as they age. The aim of this study was to examine the meaning of aging from the perspective of individuals with mental illness and explore their motivations and challenges to adopting healthy aging lifestyles and practices.Method: Using a qualitative narrative inquiry approach, interviews were conducted with 61 aging patients with mental illness aged 40 and older in community and institutional settings in Hong Kong.Results: Participants discussed the meaning of healthy aging in terms of meaningful occupation and use of time, and independence and autonomy. Motivating factors included a desire to avoid 'burdening' other people, to 'give back' to society, and gain back 'lost time'. These were connected to strategies for healthy aging, including social relationships and activities, spirituality, and healthy lifestyles. Challenges to adopting healthy aging practices included physical health difficulties and medication side effects, lack of purpose and boredom associated with daily routines and use of time, and conflicts and loss affecting family and peer relationships.Conclusion: Social and health services should be tailored to support aging individuals with mental illness and their families, addressing motivations and barriers to adopting healthy lifestyles. Promoting healthy aging practices to enable individuals with mental illness to achieve healthy aging is important for preparing for the aging of this population.

0882 Local Deformation Analysis of Lateral Cephalogram for Childhood OSA Classification

Introduction

Craniofacial profile is one of the anatomical causes of obstructive sleep apnea (OSA). Cephalometry provides information on patients’ skeletal structures and soft tissues. Traditional cephalometric analysis focuses on linear distances, angles, ratios and area of specific variables. Its classification power is often disappointed. In this study, a novel approach to cephalometric analysis using local deformation information was carried out to assess its efficacy in OSA classification.

Methods

This study was a retrospective analysis based on 60 case-control pairs who were Chinese children recruited for sleep studies in the Prince of Wales Hospital, with accessible lateral cephalometry and polysomnography (PSG) data. Local deformation technique was adopted to derive 1215 deformations from 15 manual landmarking on each cephalogram. In addition, three linear distances (hyoid bone to mandibular plane, hyoid bone to posterior pharyngeal wall, and minimal distance between tongue base and posterior pharyngeal wall) were measured from each cephalogram. A total of 1218 information features were obtained per subject. Classification models were built with an equal ratio between OSA and non-OSA groups (defined by OAHI≥1 and OAHI&lt;1 respectively). Forty pairs were used as training data and twenty pairs were used as testing data.

Results

Three model settings which used all 1218 cephalometric features, 800 features, and 500 features were tested. The accuracy for the three settings were 67.5% (sensitivity: 70%, specificity: 65%), 87.5% (sensitivity: 90%, specificity: 85%), and 92.5% (sensitivity: 95%, specificity: 90%) respectively. Apart from the three distances, the 500 topmost discriminative features were predominantly landmarks around the nasal cavity.

Conclusion

A new approach to cephalometric analysis using local deformation information can provide additional details on each cephalogram, hence, achieving better classification. The classification models using 500 features yielded the highest accuracy among the three settings. This setting could benefit most from the comprehensive comparison while avoiding overfitting.

Support

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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

Flexible Honeycombed Nanoporous/Glassy Hybrid for Efficient Electrocatalytic Hydrogen Generation

Hydrogen evolution reaction (HER) in alkaline media urgently requires electrocatalysts concurrently possessing excellent activity, flexible free-standing capability, and low cost. A honeycombed nanoporous/glassy sandwich structure fabricated through dealloying metallic glass (MG) is reported. This free-standing hybrid shows outstanding HER performance with a very small overpotential of 37 mV at 10 mA cm^-2 and a low Tafel slope of 30 mV dec^-1 in alkaline media, outperforming commercial Pt/C. By alloying 3 at% Pt into the MG precursor, a honeycombed Pt₇₅ Ni₂₅ solid solution nanoporous structure, with fertile active sites and large contact areas for efficient HER, is created on the dealloyed MG surface. Meanwhile, the surface compressive lattice-strain effect is also introduced by substituting the Pt lattice sites with the smaller Ni atoms, which can effectively reduce the hydrogen adsorption energy and thus improve the hydrogen evolution. Moreover, the outstanding stability and flexibility stemming from the ductile MG matrix also make the hybrid suitable for practical electrode application. This work not only offers a reliable strategy to develop cost-effective and flexible multicomponent catalysts with low Pt usage for efficient HER, but also sheds light on understanding the alloying effects of the catalytic process.

Cosmological Constraints from Multiple Probes in the Dark Energy Survey

The combination of multiple observational probes has long been advocated as a powerful technique to constrain cosmological parameters, in particular dark energy. The Dark Energy Survey has measured 207 spectroscopically confirmed type Ia supernova light curves, the baryon acoustic oscillation feature, weak gravitational lensing, and galaxy clustering. Here we present combined results from these probes, deriving constraints on the equation of state, w, of dark energy and its energy density in the Universe. Independently of other experiments, such as those that measure the cosmic microwave background, the probes from this single photometric survey rule out a Universe with no dark energy, finding w=-0.80_{-0.11}^{+0.09}. The geometry is shown to be consistent with a spatially flat Universe, and we obtain a constraint on the baryon density of Ω_{b}=0.069_{-0.012}^{+0.009} that is independent of early Universe measurements. These results demonstrate the potential power of large multiprobe photometric surveys and pave the way for order of magnitude advances in our constraints on properties of dark energy and cosmology over the next decade.

Early Diagnosis of Spastic Cerebral Palsy in Infants with Periventricular White Matter Injury Using Diffusion Tensor Imaging

BACKGROUND AND PURPOSE

Periventricular white matter injury is the common cause of spastic cerebral palsy. However, the early diagnosis of spastic cerebral palsy still remains a challenge. Our aim was to investigate whether infants with periventricular white matter injury with bilateral spastic cerebral palsy have unique lesions different from those in infants without cerebral palsy and to evaluate the efficiency of DTI in the early diagnosis of spastic cerebral palsy.

MATERIALS AND METHODS

Infants with periventricular white matter injury and controls underwent MR imaging at 6-18 months of age. Fractional anisotropy was calculated from DTI. Cerebral palsy was diagnosed by 24-30 months of age. Subjects were divided into 3 groups: infants with periventricular white matter injury with bilateral spastic cerebral palsy, infants with periventricular white matter injury without cerebral palsy, and controls. Tract-Based Spatial Statistics and Automated Fiber Quantification were used to investigate intergroup differences. Receiver operating characteristic curves were used to assess the diagnostic accuracy of spastic cerebral palsy. Correlations between motor function scores and fractional anisotropy were evaluated along white matter tracts.

RESULTS

There were 20, 19, and 33 subjects in periventricular white matter injury with spastic cerebral palsy, periventricular white matter injury without cerebral palsy, and control groups, respectively. Decreased fractional anisotropy in the corticospinal tract was only observed in infants with periventricular white matter injury with spastic cerebral palsy, whereas decreased fractional anisotropy in the posterior thalamic radiation and genu and splenium of the corpus callosum was seen in both periventricular white matter injury subgroups. Fractional anisotropy in the corticospinal tract at the internal capsule level was effective in differentiating infants with periventricular white matter injury with spastic cerebral palsy from those without cerebral palsy by a threshold of 0.53, and it had strong correlations with motor function scores.

CONCLUSIONS

Corticospinal tract lesions play a crucial role in motor impairment related to spastic cerebral palsy in infants with periventricular white matter injury. Fractional anisotropy in the corticospinal tract at the internal capsule level could aid in the early diagnosis of spastic cerebral palsy with high diagnostic accuracy.

Evolutionarily distinct amphibians are disproportionately lost from human-modified ecosystems

Humans continue to alter terrestrial ecosystems, but our understanding of how biodiversity responds is still limited. Anthropogenic habitat conversion has been associated with the loss of evolutionarily distinct bird species at local scales, but whether this evolutionary pattern holds across other clades is unknown. We collate a global dataset on amphibian assemblages in intact forests and nearby human-modified sites to assess whether evolutionary history influences susceptibility to land conversion. We found that evolutionarily distinct amphibian species are disproportionately lost when forested habitats are converted to alternative land-uses. We tested the hypothesis that grassland-associated amphibian lineages have both higher diversification and are pre-adapted to human landscapes, but found only weak evidence supporting this. The loss of evolutionarily distinct amphibians with land conversion suggests that preserving remnant forests will be vital if we aim to preserve the amphibian tree of life in the face of mounting anthropogenic pressures.

Female Trauma Patients in the Emergency Department: Should their Injury Prevention Programme be Different?

Background

(1) To compare the characteristics of female and male trauma patients seen in the Emergency Department (ED) and (2) to determine if injury prevention programmes for women should be different.

Methods

A prospective survey was conducted for 11544 trauma patients, aged 15 years and above, who presented to the ED of an urban public hospital in Singapore over 6 months. The following data were collected: demography, place, type and mechanism of injury and subsequent disposition from the ED.

Results

Almost half (49.5%) the injuries sustained by females occurred at home, with low falls of less than 2 metres being the most common mechanism of injury (52.7%). Victims of domestic violence were predominantly female at p<0.0001.

Conclusion

Injury prevention programs for women should focus on home safety and low falls. Special assistance programs for the victims of domestic violence should be available in the ED as the latter may be their only access to safety.

Fe-based metallic glass catalyst with nanoporous surface for azo dye degradation

In this work, porous structures were introduced to the surface of Fe-based metallic glass ribbons for the first time by chemical treatment in order to increase the catalytic activity in the degradation of azo dyes. The results show that etching treatment in an HF solution with a volume concentration of 20% for 40 min leads to a porous structure on the FeSiBNb metallic glass with a dramatic increase in the specific surface area by 25 times. The much higher specific surface area of the porous ribbons greatly improves the catalytic activity in the degradation of Direct Blue 15 when compared with as-spun metallic ribbons.

Flaw-induced plastic-flow dynamics in bulk metallic glasses under tension

Inheriting amorphous atomic structures without crystalline lattices, bulk metallic glasses (BMGs) are known to have superior mechanical properties, such as high strength approaching the ideal value, but are susceptible to catastrophic failures. Understanding the plastic-flow dynamics of BMGs is important for achieving stable plastic flow in order to avoid catastrophic failures, especially under tension, where almost all BMGs demonstrate limited plastic flow with catastrophic failure. Previous findings have shown that the plastic flow of BMGs displays critical dynamics under compression tests, however, the plastic-flow dynamics under tension are still unknown. Here we report that power-law critical dynamics can also be achieved in the plastic flow of tensile BMGs by introducing flaws. Differing from the plastic flow under compression, the flaw-induced plastic flow under tension shows an upward trend in the amplitudes of the load drops with time, resulting in a stable plastic-flow stage with a power-law distribution of the load drop. We found that the flaw-induced plastic flow resulted from the stress gradients around the notch roots, and the stable plastic-flow stage increased with the increase of the stress concentration factor ahead of the notch root. The findings are potentially useful for predicting and avoiding the catastrophic failures in tensile BMGs by tailoring the complex stress fields in practical structural-applications.

Origin of Shear Stability and Compressive Ductility Enhancement of Metallic Glasses by Metal Coating

Metallic glasses (MGs) are notorious for the poor macroscopic ductility and to overcome the weakness various intrinsic and extrinsic strategies have been proposed in past decades. Among them, the metal coating is regarded as a flexible and facile approach, yet the physical origin is poorly understood due to the complex nature of shear banding process. Here, we studied the origin of ductile enhancement in the Cu-coating both experimentally and theoretically. By examining serrated shear events and their stability of MGs, we revealed that the thin coating layer plays a key role in stopping the final catastrophic failure of MGs by slowing down shear band dynamics and thus retarding its attainment to a critical instable state. The mechanical analysis on interplay between the coating layer and shear banding process showed the enhanced shear stability mainly comes from the lateral tension of coating layer induced by the surface shear step and the bonding between the coating layer and MGs rather than the layer thickness is found to play a key role in contributing to the shear stability.

Loading-rate-independent delay of catastrophic avalanches in a bulk metallic glass

The plastic flow of bulk metallic glasses (BMGs) is characterized by intermittent bursts of avalanches, and this trend results in disastrous failures of BMGs. In the present work, a double-side-notched BMG specimen is designed, which exhibits chaotic plastic flows consisting of several catastrophic avalanches under the applied loading. The disastrous shear avalanches have, then, been delayed by forming a stable plastic-flow stage in the specimens with tailored distances between the bottoms of the notches, where the distribution of a complex stress field is acquired. Differing from the conventional compressive testing results, such a delaying process is independent of loading rate. The statistical analysis shows that in the specimens with delayed catastrophic failures, the plastic flow can evolve to a critical dynamics, making the catastrophic failure more predictable than the ones with chaotic plastic flows. The findings are of significance in understanding the plastic-flow mechanisms in BMGs and controlling the avalanches in relating solids.

Outcome of elderly patients who receive intensive care at a regional hospital in Hong Kong

OBJECTIVE

To evaluate the clinical outcome (180-day mortality) of very elderly critically ill patients (age ≥80 years) and compare with those aged 60 to 79 years.

DESIGN

Historical cohort study.

SETTING

Regional hospital, Hong Kong.

PATIENTS

Patients aged ≥60 years admitted between 1 January 2009 and 31 December 2013 to the Intensive Care Unit of the hospital.

RESULTS

Over 5 years, 4226 patients aged ≥60 years were admitted (55.5% total intensive care unit admissions), of whom 32.8% were aged ≥80 years. The proportion of patients aged ≥80 years increased over 5 years. As expected, those aged ≥80 years carried more significant co-morbidities and a higher disease severity compared with those aged 60 to 79 years. They required more mechanical ventilatory support, were less likely to receive renal replacement therapy, and had a higher intensive care unit/hospital/180-day mortality compared with those aged 60 to 79 years. Nonetheless, 71.8% were discharged home and 62.2% survived >180 days following intensive care unit admission. Cox regression analysis revealed that Acute Physiology and Chronic Health Evaluation IV-minus-Age score, emergency admission, intensive care unit admission due to cardiovascular problem, neurosurgical cases, presence of significant co-morbidities (diabetes mellitus, metastatic carcinoma, leukaemia, or myeloma), and requirement for mechanical ventilation independently predicted 180-day mortality.

CONCLUSIONS

The proportion of critically ill patients aged ≥80 years increased over a 5-year period. Despite having more significant co-morbidities, greater disease severity, and higher intensive care unit/hospital/180-day mortality rate compared with those aged 60 to 79 years, 71.8% of those ≥80 years could be discharged home and 62.2% survived >180 days following intensive care unit admission. Disease severity, presence of co-morbidities, requirement for mechanical ventilation, emergency cases, and admission diagnosis independently predicted 180-day mortality.

Healthcare provider targeted interventions to improve medication adherence: systematic review and meta-analysis

OBJECTIVE

This systematic review applied meta-analytic procedures to synthesise medication adherence (also termed compliance) interventions that focus on healthcare providers.

DESIGN

Comprehensive searching located studies testing interventions that targeted healthcare providers and reported patient medication adherence behaviour outcomes. Search strategies included 13 computerised databases, hand searches of 57 journals, and both author and ancestry searches. Study sample, intervention characteristics, design and outcomes were reliably coded. Standardised mean difference effect sizes were calculated using random-effects models. Heterogeneity was examined with Q and I(2) statistics. Exploratory moderator analyses used meta-analytic analogue of ANOVA and regression.

RESULTS

Codable data were extracted from 218 reports of 151,182 subjects. The mean difference effect size was 0.233. Effect sizes for individual interventions varied from 0.088 to 0.301. Interventions were more effective when they included multiple strategies. Risk of bias assessment documented larger effect sizes in studies with larger samples, studies that used true control groups (as compared with attention control), and studies without intention-to-treat analyses.

CONCLUSION

Overall, this meta-analysis documented that interventions targeted to healthcare providers significantly improved patient medication adherence. The modest overall effect size suggests that interventions addressing multiple levels of influence on medication adherence may be necessary to achieve therapeutic outcomes.

Anti-angiogenic pathway associations of the 3p21.3 mapped BLU gene in nasopharyngeal carcinoma

Zinc-finger, MYND-type containing 10 (ZMYND10), or more commonly called BLU, expression is frequently downregulated in nasopharyngeal carcinoma (NPC) and many other tumors due to promoter hypermethylation. Functional evidence shows that the BLU gene inhibits tumor growth in animal assays, but the detailed molecular mechanism responsible for this is still not well understood. In current studies, we find that 93.5% of early-stage primary NPC tumors show downregulated BLU expression. Using a PCR array, overexpression of the BLU gene was correlated to the angiogenesis network in NPC cells. Moreover, expression changes of the MMP family, VEGF and TSP1, were often detected in different stages of NPC, suggesting the possibility that BLU may be directly involved in the microenvironment and anti-angiogenic activity in NPC development. Compared with vector-alone control cells, BLU stable transfectants, derived from poorly-differentiated NPC HONE1 cells, suppress VEGF165, VEGF189 and TSP1 expression at both the RNA and protein levels, and significantly reduce the secreted VEGF protein in these cells, reflecting an unknown regulatory mechanism mediated by the BLU gene in NPC. Cells expressing BLU inhibited cellular invasion, migration and tube formation. These in vitro results were further confirmed by in vivo tumor suppression and a matrigel plug angiogenesis assay in nude mice. Tube-forming ability was clearly inhibited, when the BLU gene is expressed in these cells. Up to 70-90% of injected tumor cells expressing increased exogenous BLU underwent cell death in animal assays. Overexpressed BLU only inhibited VEGF165 expression in differentiated squamous NPC HK1 cells, but also showed an anti-angiogenic effect in the animal assay, revealing a complicated mechanism regulating angiogenesis and the microenvironment in different NPC cell lines. Results of these studies indicate that alteration of BLU gene expression influences anti-angiogenesis pathways and is important for the development of NPC.

Osteopenic consequences of botulinum toxin injections in the masticatory muscles: a pilot study

Patients with temporomandibular muscle and joint disorder (TMJD) increasingly seek and receive treatment for their pain with botulinum toxin (BoNTA; botulinum toxin A). Used intramuscularly in therapeutic doses, it produces localised paresis. Such paresis creates risk of reduced bone mineral density, or 'disuse osteopenia'. Animal studies have frequently used BoNTA as a model of paralysis to induce bone changes within short periods. Osteopenic effects can be enduring in animals but have yet to be studied in humans. This is the first study in humans to examine bone-related consequences of BoNTA injections in the masticatory muscles, comparing oral and maxillofacial radiologists' ratings of trabecular bone patterns in the condyles of patients with TMJD exposed to multiple masticatory muscle injection sessions with BoNTA to a sample of patients with TMJD unexposed to masticatory muscle injections with BoNTA. Cone-beam computed tomography (CBCT)-derived images of bilateral condyles were evaluated in seven patients with TMJD receiving 2+ recent BoNTA treatment sessions for facial pain and nine demographically matched patients with TMJD not receiving BoNTA treatment. Two oral and maxillofacial radiologists evaluated CBCT images for evidence of trabecular changes consistent with osteopenia. Both evaluators noted decreased density in all participants exposed to BoNTA and in none of the unexposed participants (P < 0.001). No other abnormalities associated with reduced loading were detected. These findings need replication in a larger sample and over a longer time period, to ensure safety of patients with TMJD receiving multiple BoNTA injections for their pain.

SAA1 polymorphisms are associated with variation in antiangiogenic and tumor-suppressive activities in nasopharyngeal carcinoma

Nasopharyngeal carcinoma (NPC) is a cancer that occurs in high frequency in Southern China. A previous functional complementation approach and the subsequent cDNA microarray analysis have identified that serum amyloid A1 (SAA1) is an NPC candidate tumor suppressor gene. SAA1 belongs to a family of acute-phase proteins that are encoded by five polymorphic coding alleles. The SAA1 genotyping results showed that only three SAA1 isoforms (SAA1.1, 1.3 and 1.5) were observed in both Hong Kong NPC patients and healthy individuals. This study aims to determine the functional role of SAA1 polymorphisms in tumor progression and to investigate the relationship between SAA1 polymorphisms and NPC risk. Indeed, we have shown that restoration of SAA1.1 and 1.3 in the SAA1-deficient NPC cell lines could suppress tumor formation and angiogenesis in vitro and in vivo. The secreted SAA1.1 and SAA1.3 proteins can block cell adhesion and induce apoptosis in the vascular endothelial cells. In contrast, the SAA1.5 cannot induce apoptosis or inhibit angiogenesis because of its weaker binding affinity to αVβ3 integrin. This can explain why SAA1.5 has no tumor-suppressive effects. Furthermore, the NPC tumors with this particular SAA1.5/1.5 genotype showed higher levels of SAA1 gene expression, and SAA1.1 and 1.3 alleles were preferentially inactivated in tumor tissues that were examined. These findings further strengthen the conclusion for the defective function of SAA1.5 in suppression of tumor formation and angiogenesis. Interestingly, the frequency of the SAA1.5/1.5 genotype in NPC patients was ~2-fold higher than in the healthy individuals (P=0.00128, odds ratio=2.28), which indicates that this SAA1 genotype is significantly associated with a higher NPC risk. Collectively, this homozygous SAA1.5/1.5 genotype appears to be a recessive susceptibility gene, which has lost the antiangiogenic function, whereas SAA1.1 and SAA1.3 are the dominant alleles of the tumor suppressor phenotype.

Intraosseous mucoepidermoid carcinoma: a review of the diagnostic imaging features of four jaw cases

The purpose of this case series is to present the common features of intraosseous mucoepidermoid carcinoma (IMC) of the jaws in plain film and CT imaging. Two oral and maxillofacial radiologists reviewed and characterized the common features of four biopsy-proven cases of IMC in the jaws in plain film and CT imaging obtained from the files of the Department of Oral Radiology, Faculty of Dentistry, University of Toronto, Toronto, Canada. The common features are a well-defined sclerotic periphery, the presence of internal amorphous sclerotic bone and numerous small loculations, lack of septae bordering many of the loculations, and expansion and perforation of the outer cortical plate with extension into surrounding soft tissue. Other characteristics include tooth displacement and root resorption. The four cases of IMC reviewed have common imaging characteristics. All cases share some diagnostic imaging features with other multilocular-appearing entities of the jaws. However, the presence of amorphous sclerotic bone and malignant characteristics can be useful in the differential diagnosis.

Application of endotoxin and cytokine adsorption haemofilter in septic acute kidney injury due to Gram-negative bacterial infection

OBJECTIVE

Endotoxins and cytokines play an important role in the pathogenesis of multi-organ failure and mortality in patients suffering from severe Gram-negative bacterial infection. The aim of this study was to determine whether in patients with such infections, use of a haemofilter with enhanced endotoxin haemoadsorption and cytokine removal properties helps to overcome organ dysfunction.

DESIGN

Prospective case series study with historical controls.

SETTING

A regional hospital in Hong Kong.

PATIENTS

From October 2011 to June 2012, patients with sepsis-induced acute kidney injury due to Gram-negative bacteria were recruited. Continuous venovenous haemofiltration using oXiris haemofilter was performed. The patients' APACHE (Acute Physiology And Chronic Health Evaluation) II and inclusion criteria matched those of a series of selected historical controls who had been treated with continuous venovenous haemofiltration using polysulfone-based haemofilter from 2009 to 2011. The percentage reduction in the Sequential Organ Failure Assessment score by 24 and 48 hours, the percentage reduction of noradrenaline equivalent usage by 48 hours, as well as intensive care unit and hospital mortality in the two groups were compared.

RESULTS

Pre-treatment biochemical parameters and vasopressor use in the six patients undergoing the intervention and the 24 historical controls were similar. The mean circuit life of oXiris was about 61 hours. The Sequential Organ Failure Assessment score was significantly reduced by 37% at 48 hours post-initiation of oXiris-continuous venovenous haemofiltration versus an increment of 3% in the historical controls. No significant side-effect was detected. Mortality was similar in the two groups.

CONCLUSION

The haemofilter membrane with enhanced endotoxin adsorption and cytokine removal capacity was a safe alternative to traditional polysulfone-based continuous venovenous haemofiltration and expedited improvement in organ dysfunction.

Synergistic Effect of Scutellaria baicalensis and Grape Seed Proanthocyanidins on Scavenging Reactive Oxygen Species in Vitro

Scutellaria baicalensis (SbE) is a commonly used Chinese herb medicine and grape seed proanthocyanidins is a popular herbal supplement in the United States. Both herbs have been shown to possess potent antioxidant effects. Using an in vitro model to produce the reactive oxygen species (ROS) generation ( H 2 O 2/ FeSO 4 for hydroxyl radicals, xanthine/xanthine oxidase for suproxide), we observed that Scutellaria baicalensis and grape seed proanthocyanidins acted synergistically to scavenge ROS. Our data suggest that a combination of these two herbs can potentially enhance their antioxidant efficacy, allowing lower dosages of each drug to be used. This has the advantage of avoiding possible side effects that may arise when higher doses of a single herb are used in an attempt to achieve a maximum degree of antioxidant activity.

Cast nephropathy with acute renal failure treated with high cut-off haemodialysis in a patient with multiple myeloma

We report a case of a Chinese woman who presented with multiple myeloma and acute renal failure due to cast nephropathy, with an extremely high serum lambda free light chain concentration. She was successfully treated with chemotherapy and high cut-off extended haemodialysis. High cut-off haemodialysis is a new treatment modality which can achieve rapid free light chain clearance. This may contribute to a better renal outcome and overall prognosis for patients with multiple myeloma.

Changing epidemiology of hand, foot, and mouth disease in Hong Kong, 2001-2009

We report the surveillance findings of hand, foot, and mouth disease (HFMD) collected from a general practitioner-based sentinel surveillance system and outbreaks reported by institutions and a laboratory-based enterovirus surveillance system in Hong Kong from 2001 to 2009. A seasonal peak was detected in the warmer months (May-July), along with a smaller winter peak (October-December) from 2006 onwards. The number of older children (>5 years) infected increased from 25.4% in 2001 to 33.0% in 2009 (P=0.01, Mantel-Haenszel chi-square test). Laboratory surveillance detected a cyclical high enterovirus 71 activity every 3 to 4 years. This activity was associated with a higher average hospitalization rate for HFMD patients in the outbreaks reported in the corresponding year, although the difference was only marginally significant (P=0.09, linear regression test). The changing epidemiology of HFMD warrants continuous surveillance in order to guide preventive public-health actions.

Size-effect induced short-range magnetic ordering in germanium nanostructures

Formation of ordered magnetic states in germanium nanostructures embedded in SiO2 has been investigated. Samples with the nanostructures were prepared by sputtering deposition on Si(100) substrates, followed by thermal annealing in vacuum. Transmission electron microscopy, energy dispersive X-ray spectrometry, and Raman spectroscopy have been used to characterize the samples. Magnetic measurements were performed using a superconducting quantum interference device. Size-effect induced magnetic orderings in the germanium nanostructures were found to be present at room temperatures and below. Superparamagnetic behavior was observed at temperatures above 230 K, whereas thermal excitation of spin reorientation and magnetic coupling has been revealed at temperatures below 60 K. Inverted hysteresis loops with negative remanences and multiple plateaus revealed the ferri- or antiferromagnetic nature of the coupling. Inter-domain coupling and effect of magnetic anisotropy will be discussed based on the experimental results and simulations with a spin reorientation model.

Hot weather warning might help to reduce elderly mortality in Hong Kong

While there was evidence on the relationship between extreme hot weather and the increase in mortality, particularly from ischaemic heart disease (IHD) and cerebrovascular disease (stroke), some researchers suggested that early warning systems might reduce mortality. In this study, the relationship between Very Hot Weather Warning (VHWW) and mortality was examined in the context of Hong Kong, which has a sub-tropical climate. An observational study was conducted on the daily number of deaths due to IHD and stroke in the Hong Kong elderly population (aged 65 or above) during summer (May-September) in 1997-2005. Totals of 4,281 deaths from IHD and 4,764 deaths from stroke occurred on days with maximum temperature reaching/exceeding 30.4 degrees C. Multiple linear regression models were used to study the association between VHWW and the daily mortality rates from IHD and from stroke, respectively. Results showed that absence of VHWW was associated with an increase of about 1.23 (95% CI: 0.32, 2.14) deaths from IHD and 0.97 (95% CI: 0.02, 1.92) deaths from stroke among the elderly per day. Public education is required to inform the elderly to take appropriate preventive measures and to remind the public to pay more care and attention to the elderly on days which are not considered to be stressful to the general public. Warning systems tailored for the elderly could also be considered.

Profiling Acute Presenting Symptoms of Geriatric Patients Attending an Urban Hospital Emergency Department

Objective: To study the profile of geriatric patients warded to the emergency department (ED) of an Asian acute care general hospital and determine if they are ‘more ill’, more likely to have atypical presentations and have a higher utilisation of healthcare resources when compared to a younger group of patients. Materials and Methods: This is a retrospective chart review of consecutive patients aged 45 years and above presenting to the study ED over a period of 4 weeks from 4 June 2006 to 1 July 2006. The following data were obtained: (i) demographics, (ii) mode of arrival and triage acuity, (iii) presence of co-morbidities, (iv) investigations ordered in the ED, (v) clinical symptoms and diagnoses, (vi) disposition, (vii) length of hospital stay, (viii) injuries and outcomes of elderly fallers. The study population was divided into 2 groups – a study group with patients aged 65 years and above, and a control group with patients aged 45 to 64. Results: There were 2847 patients in the study group and these were compared against 2875 in the control group. Those 65 years and above had greater representation in the ED population compared to the general population. In the study group, the proportion of females, the number arriving by ambulance and the likelihood of having a higher triage acuity increased with age. The elderly had higher rates of co-morbidities. They also had a higher resource utilisation rate. Falls was their commonest presenting complaint. Conclusion: It is crucial that EDs recognise the special needs of elderly patients due to the growing ageing population. Healthcare policy makers when allocating resources should take into account the profile of elderly patients presenting to an ED and their resource utilisation. Key words: Elderly, Presentation, Symptomology

Profiling acute presenting symptoms of geriatric patients attending an urban hospital emergency department

OBJECTIVE

To study the profile of geriatric patients warded to the emergency department (ED) of an Asian acute care general hospital and determine if they are 'more ill', more likely to have atypical presentations and have a higher utilisation of healthcare resources when compared to a younger group of patients.

MATERIALS AND METHODS

This is a retrospective chart review of consecutive patients aged 45 years and above presenting to the study ED over a period of 4 weeks from 4 June 2006 to 1 July 2006. The following data were obtained: (i) demographics, (ii) mode of arrival and triage acuity, (iii) presence of co-morbidities, (iv) investigations ordered in the ED, (v) clinical symptoms and diagnoses, (vi) disposition, (vii) length of hospital stay, (viii) injuries and outcomes of elderly fallers. The study population was divided into 2 groups--a study group with patients aged 65 years and above, and a control group with patients aged 45 to 64.

RESULTS

There were 2847 patients in the study group and these were compared against 2875 in the control group. Those 65 years and above had greater representation in the ED population compared to the general population. In the study group, the proportion of females, the number arriving by ambulance and the likelihood of having a higher triage acuity increased with age. The elderly had higher rates of co-morbidities. They also had a higher resource utilisation rate. Falls was their commonest presenting complaint.

CONCLUSION

It is crucial that EDs recognise the special needs of elderly patients due to the growing ageing population. Healthcare policy makers when allocating resources should take into account the profile of elderly patients presenting to an ED and their resource utilisation.

Identifying rodent olfactory bulb structures with micro-DTI

Olfactory bulb (OB) is one of the most developed systems in rodent models with complex neuronal organization and anatomical structures. MR diffusion tensor imaging (DTI) is a non-invasive technique to probe tissue microstructures by examining the diffusion characteristics of water molecules. This paper presents how different OB layers can be identified and quantitatively characterized by micro-DTI using a specially constructed micro-imaging radio frequency (RF) coil. High spatial resolution and high signal to noise ratio (SNR) DTI images of ex vivo rat OBs were obtained. Distinct contrasts were observed between various olfactory bulb layers in trace map, fractional anisotropy (FA) map and FA color map, all in consistency with the known OB neuroanatomy. These experimental results demonstrate the utility of micro-DTI in investigation of complex OB organization.

Intraoperative coagulation was more interfered by HES 200/0.5 than normal saline in off-pump coronary artery bypass surgery

AIM

Rapid fluid administration is often necessary for anesthesiologists to maintain intravascular volume in off-pump coronary artery bypass (OPCAB) with acceptable hematocrits. Postoperative hypocoagulation involving postoperative bleeding and hypercoagulation involving graft patency were focused in previous studies but bleeding and blood transfusion are often peaked during vascular anastomoses during OPCAB. This study is designed to investigate the sequential effects of intraoperative coagulation with normal saline and hydroxyethyl starch (HES) solution by thromboelastography (TEG) and standard coagulation tests (SCT).

METHODS

Twenty adult patients scheduled for OPCAB were enrolled in this study. After anesthetic induction, one group received HES 200/0.5 infusion up to 20 mL/kg and the other received 0.9% normal saline (NS) to maintain central venous pressure (CVP) and pulmonary artery occlusion pressures (PAOP). SCT and TEG were measured at T0 (baseline), T1 (after heparin 150 IU/kg, before vascular anastomoses), T2 (after protamine reversal), and T3 (24 hrs after the surgery) to compare the coagulation status.

RESULTS

Baseline data were comparable in both groups. The number of patient who need blood components is higher in HES group. Dilutional hypocoagulation was shown by a significant prolongation of R time at T1 and T2 but also returned comparable at T3 in both groups. K, a-angle, CI and G remained unchanged in NS group but significantly affected in HES group. A statistically significant interaction between groups and treatments on maximal amplitude (MA) (P<0.01) with more blood loss in HES group 24 hours postoperatively (P=0.05). International Normalized Ratio (INR) increased significantly at T2 and T3 in both groups.

CONCLUSION

A rapid infusion of either normal saline or HES solution to maintain intraoperative intravascular volume induce a significant diluted hypocoagulation during OPCAB. The use of HES solution has a prolonged dilutional hypocoagulation and a significant decrease of MA by specific platelet inhibition effects and more transfusion of blood components. All the above changes were not shown in standard coagulation tests.

Aeromonas hydrophila bacteraemia and portal pyaemia

The Aeromonas species uncommonly cause disease in humans. We report portal pyaemia secondary to Aeromonas hydrophila bacteraemia occurring in a 71-year-old Chinese man with no history of hepatobiliary disease or malignancy. He presented with fever, rigors and abdominal bloating for four days and was subsequently found to have Aeromonas hydrophila bacteraemia, portal vein thrombosis and a psoas abscess. He was treated with ciprofloxacin and had a good recovery. Aeromonas hydrophila infection is an uncommon cause of intestinal and extraintestinal infection in man, but must be suspected in immunocompromised hosts and in those exposed to brackish or salt water.

Transient and partial mitochondrial inhibition for the treatment of postresuscitation injury: getting it just right

OBJECTIVE

Within minutes of reperfusing ischemic cardiomyocytes, oxidant stress dramatically increases and is associated with postresuscitation injury. Because mitochondria produce deleterious oxidants and useful metabolic substrates, utilization of electron transport chain inhibitors against reperfusion injury, though promising, must not overly compromise recovery of mitochondrial function. This study sought to further characterize the oxidant source at reperfusion and develop a strategy for therapeutic intervention by manipulation of dose, duration, and the degree of reversibility of mitochondrial inhibition.

DESIGN

Comparative laboratory investigation.

SETTING

Laboratory of a research university.

SUBJECTS

Embryonic chick cardiomyocytes.

INTERVENTIONS

Synchronously contracting chick cardiomyocytes were exposed to 1 hr of simulated ischemia and 3 hrs of reperfusion and were monitored for cell viability (propidium iodide) and oxidant generation (dichlorofluorescein). Inhibitors were administered either all course or for the first 15 mins of reperfusion.

MEASUREMENTS AND MAIN RESULTS

: Application of diethyldithiocarbamic acid, 2-anthracene-carboxylic acid (rhein tech), and alpha-nicotinamide adenine dinucleotide dehydrogenase (NADH) demonstrated attenuation of the oxidant burst. In addition, diethyldithiocarbamic acid (1 mM), rhein tech (0.1 microM), and alpha-NADH (20 microM) significantly attenuated cell death from a control of 49.7% +/- 6.7% to 15.7% +/- 4.7% (n = 5, p < .01), 26.1% +/- 4.1% (n = 5, p < .01), and 13.8% +/- 1.3% (n = 5, p < .001), respectively. All doses of stigmatellin attenuated reactive oxygen species, but only a 2-20 nM dose during the first 15 mins of reperfusion abrogated cell death from 53.8% +/- 3.5% to 10.8% +/- 2.9% (n = 5, p < .001). Increased doses and durations of stigmatellin abolished reactive oxygen species but augmented injury. Although rotenone (5 microM) attenuated reactive oxygen species, no dose or duration of exposure that ameliorated cell death was found.

CONCLUSIONS

Early events of reperfusion are marked by rapid mitochondrial oxidant generation and postresuscitation injury. Electron transport chain blockade provides an effective method of attenuating reactive oxygen species. However, inhibitor administration should be both transient and reversible to necessitate cardioprotection and successful metabolic recovery.

Hypothermia-induced cardioprotection using extended ischemia and early reperfusion cooling

Optimal timing of therapeutic hypothermia for cardiac ischemia is unknown. Our prior work suggests that ischemia with rapid reperfusion (I/R) in cardiomyocytes can be more damaging than prolonged ischemia alone. Also, these cardiomyocytes demonstrate protein kinase C (PKC) activation and nitric oxide (NO) signaling that confer protection against I/R injury. Thus we hypothesized that hypothermia will protect most using extended ischemia and early reperfusion cooling and is mediated via PKC and NO synthase (NOS). Chick cardiomyocytes were exposed to an established model of 1-h ischemia/3-h reperfusion, and the same field of initially contracting cells was monitored for viability and NO generation. Normothermic I/R resulted in 49.7 +/- 3.4% cell death. Hypothermia induction to 25 degrees C was most protective (14.3 +/- 0.6% death, P < 0.001 vs. I/R control) when instituted during extended ischemia and early reperfusion, compared with induction after reperfusion (22.4 +/- 2.9% death). Protection was completely lost if onset of cooling was delayed by 15 min of reperfusion (45.0 +/- 8.2% death). Extended ischemia/early reperfusion cooling was associated with increased and sustained NO generation at reperfusion and decreased caspase-3 activation. The NOS inhibitor N(omega)-nitro-L-arginine methyl ester (200 microM) reversed these changes and abrogated hypothermia protection. In addition, the PKCepsilon inhibitor myr-PKCepsilon v1-2 (5 microM) also reversed NO production and hypothermia protection. In conclusion, therapeutic hypothermia initiated during extended ischemia/early reperfusion optimally protects cardiomyocytes from I/R injury. Such protection appears to be mediated by increased NO generation via activation of protein kinase Cepsilon; nitric oxide synthase.

Initial transcatheter palliation of hypoplastic left heart syndrome

Initial percutaneous transcatheter palliation of hypoplastic left heart syndrome is now feasible. The primary procedures for palliation include stenting of the ductus arteriosus with a self expanding nitinol stent to secure an adequate systemic blood flow, placement of an internal pulmonary arterial band to protect the pulmonary vascular bed and to prevent pulmonary overcirculation, and widening of the interatrial communication by blade and balloon septostomy or static balloon dilation to decompress the left atrium. Anatomic variations of the ductus arteriosus have important implications for technical success with ductal stenting. Patients who have undergone complete transcatheter palliation with the internal pulmonary band appear to have less immediate morbidity at the time of transplant, with preserved integrity and growth of the branch pulmonary arteries at one year follow-up.

Nitrite-induced methaemoglobinaemia - aetiology, diagnosis and treatment

A 41-year-old woman presented with the clinical features of methaemoglobinaemia after drinking Chinese herbal medicine. A life threatening methaemoglobin level of 68% was measured. Both clinical and laboratory diagnostic difficulties were encountered. The pitfalls of pulse oximeter, blood gas analysis and co-oximeter interpretation during diagnosis and after methylene blue administration are discussed.

Ductal anatomy: a determinant of successful stenting in hypoplastic left heart syndrome

Interventional palliation for hypoplastic left heart syndrome (HLHS) could reduce the current morbidity and mortality. Stenting of the arterial duct is the critical interventional step for HLHS. We reviewed our experience with 40 consecutive patients with HLHS referred for stenting of the ductus arterious (DA). Thirty-nine of 40 (97%) infants had suitable anatomy and were successfully stented. The infants were grouped by orientation of the ductus in the frontal plane. Type 1 DA anatomy had a leftward loop at a mean orientation of 18 degrees from the vertical plane. Type 2 ductal anatomy was mesoverted, with a mean orientation of 7.1 degrees from the vertical plane. Type 3 ductal anatomy displayed a rightward axis, with a mean of -4 degrees rightward. Orientation of the DA was significantly related to length of the ductus, number of stents required for complete coverage, and technical and procedural complications. Type 1 DA occurred in 65% of patients, and there was 100% technical success, no mortality, and only an 8% incidence of complications. Type 2 anatomy occurred in 27% of patients and there was 100% success. However, the technical and procedural complications increased to approximately 50%. Type 3 ductal anatomy was seen in only 3 patients, 2 of whom were successfully stented. There was no procedural-related mortality, and all stented patients were weaned from prostaglandin. There were only two late complications (coarctation). We conclude that ductal stenting using self-expanding nitinol stents is successful in more than 95% of infants with HLHS. Patients with HLHS and favorable ductal anatomy should be considered for primary ductal stenting.

Performance of Large-Size Superconducting Coil in 0.21T MRI System

A high-temperature superconductor (HTS) was used on magnetic resonance imaging (MRI) receiver coils to improve image quality because of its intrinsic low electrical resistivity. Typical HTS coils are surface coils made of HTS thin-film wafers. Their applications are severely limited by the field of view (FOV) of the surface coil configuration, and the improvement in image quality by HTS coil is also reduced as the ratio of sample noise to coil noise increases. Therefore, previous HTS coils are usually used to image small in vitro samples, small animals, or peripheral human anatomies. We used large-size HTS coils (2.5-, 3.5-, and 5.5-in mean diameter) to enhance the FOV and we evaluated their performance through phantom and human MR images. Comparisons were made among HTS surface coils, copper surface coils, and cool copper surface coils in terms of the signal-to-noise ratio (SNR) and sensitivity profile of the images. A theoretical model prediction was also used to compare against the experimental result. We then selected several human body parts, including the wrist, feet, and head, to illustrate the advantage of HTS coil over copper coil when used in human imaging. The results show an SNR gain of 200% for 5.5-in HTS coil versus same size copper coils, while for 2.5- and 3.5-in coils it is 250%. We also address the various factors that affect the performance of large size HTS coils, including the coil-to-sample spacing due to cryogenic probe and the coil-loading effect.

Short-term and long-term results of endoscopic balloon dilation for achalasia: 12 years' experience

BACKGROUND AND STUDY AIMS

This retrospective study reports 12 years' experience with pneumatic dilation treatment in patients with achalasia and attempts to define factors capable of predicting failure of endoscopic dilation.

PATIENTS AND METHODS

Consecutive patients with achalasia who received endoscopic balloon dilation were studied retrospectively. Repeat dilation was carried out if dysphagia persisted or recurred. A structured symptom score questionnaire (the Eckardt score) was conducted by phone with patients who had received dilation and had been followed up for more than 2 years. Failure was defined as the presence of significant dysphagic symptoms after more than two repeat dilations. Data for the first 2 years (short-term) and for the subsequent follow-up (long-term) were analyzed.

RESULTS

From 1989 to 2001, 66 patients underwent endoscopic balloon dilation for achalasia; three perforations (4.5 %) occurred, with no mortalities. Dysphagic symptoms significantly improved 12 weeks after the procedure ( P < 0.05). Fourteen patients (20 %) required a second dilation procedure within a median of 7 months (range 1 - 52 months), and 13 of them underwent repeat dilations within the first 2 years. Five patients (7.5 %) required further surgical or endoscopic therapy. Fifty-eight patients received pneumatic dilation for more than 2 years; 32 (55 %) responded to the questionnaire. The mean dysphagia score was 1.7 (SD 1.2), with only five patients (16 %) having significant dysphagic symptoms during a median follow-up period of 55 months (range 26 - 130 months). The cumulative success rates for pneumatic dilation after 5 and 19 years were 74 % and 62 %, respectively. Cox regression analysis identified small balloon size (30 mm) as the only significant factor capable of predicting failure of endoscopic dilation ( P = 0.009; relative risk 5.3; 95 % confidence interval, 1.7 to 40.9).

CONCLUSIONS

Endoscopic balloon dilation is an effective treatment for achalasia, with minimal morbidity (60 % experience long-term benefit).

Two-port versus four-port laparoscopic cholecystectomy

BACKGROUND

Two-port laparoscopic cholecystectomy has been reported to be safe and feasible. However, whether it offers any additional advantages remains controversial. This study reports a randomized trial that compared the clinical outcomes of two-port laparoscopic cholecystectomy versus conventional four-port laparoscopic cholecystectomy.

METHODS

One hundred and twenty consecutive patients who underwent elective laparoscopic cholecystectomy were randomized to receive either the two-port or the four-port technique. All patients were blinded to the type of operation they underwent. Four surgical tapes were applied to standard four-port sites in both groups at the end of the operation. All dressings were kept intact until the first follow-up 1 week after surgery. Postoperative pain at the four sites was assessed on the first day after surgery using a 10-cm unscaled visual analog scale (VAS). Other outcome measures included analgesia requirements, length and difficulty of the operation, postoperative stay, and patient satisfaction score on surgery and scars.

RESULTS

Demographic data were comparable for both groups. Patients in the two-port group had shorter mean operative time (54.6 +/- 24.7 min vs 66.9 +/- 33.1 min for the four-post group; p = 0.03) and less pain at individual subcostal port sites [mean score using 10-cm unscaled VAS: 1.5 vs 2.8 ( p = 0.01) at the midsubcostal port site and 1.3 vs 2.3 ( p = 0.02) at the lateral subcostal port site]. Overall pain score, analgesia requirements, hospital stay, and patient satisfaction score on surgery and scars were similar between the two groups.

CONCLUSION

Two-port laparoscopic cholecystectomy resulted in less individual port-site pain and similar clinical outcomes but fewer surgical scars compared to four-port laparoscopic cholecystectomy. Thus, it can be recommended as a routine procedure in elective laparoscopic cholecystectomy.