Developing high intensity ultrasonic cleaning (HIUC) for post-processing additively manufactured metal components

The high energy phenomenon of cavitation bubble collapses has enabled numerous applications, including cleaning. In ultrasonic cleaning, cavitation intensity is typically lower than in other applications, such as sonochemistry and material processing. However, there has been an emerging application in intense cleaning of metal additively manufactured (AM) components. The presence of partially melted powders on AM surfaces is undesirable, contributing to high surface roughness and posing contamination risks during usage. We designed a high-intensity cavitation cleaning process that has significantly higher inertial cavitation intensity - i.e., erosion potential - than a conventional ultrasonic cleaning tank. Through acoustic signal characterisation, we showed that placing transducer sets on four sides of the tank could effectively focus and generate high-amplitude pressure waves directed towards the central region. Strong subharmonic signals indicate intensely inertial cavitation throughout the tank. Cavitation intensities were measured at various locations to understand the wave transmission characteristics and distribution patterns. Our results show that the cavitation intensity distribution is highly dependent on the height position. Finally, we demonstrated that the high intensity ultrasonic cleaning (HIUC) process could remove partially melted powders from an AM surface - which was not possible through conventional ultrasonic cleaning. HIUC could lead to higher cleaning efficiency and enhanced AM specimen cleanliness.

Is the Management of Rectal Cancer Using a Watch and Wait Approach Feasible, Safe and Effective in a Publicly Funded General Hospital?

AIMS

Although there is emerging evidence to suggest equivalent oncological outcomes using a watch and wait approach compared with primary total mesorectal excision surgery, there is a paucity of evidence about the safety and efficacy of this approach in routine clinical practice. Here we report the long-term outcomes and quality of life from patients managed with watch and wait following a clinical complete response (cCR) to neoadjuvant therapy.

MATERIALS AND METHODS

Patients with adenocarcinoma of the rectum with cCR following neoadjuvant therapy managed using watch and wait were retrospectively identified. Demographic data, performance status, pretreatment staging information, oncological and surgical outcomes were obtained from routinely collected clinical data. Quality of life was measured by trained clinicians during telephone interviews.

RESULTS

Over a 7-year period, 506 patients were treated for rectal cancer, 276 had neoadjuvant therapy and 72 had a cCR (26.1%). Sixty-three were managed with watch and wait. Thirteen patients had mucosal regrowth. There was no significant difference in the incidence of metastatic disease between the surgical and watch and wait cohorts (P = 0.38). The 13 patients with mucosal regrowth underwent salvage surgery. Eleven of the patients who underwent surgical resection had R0 resections. There was also a statistically and clinically significant improvement in the Functional Assessment of Cancer Therapy - Colorectal (FACT-C) trial outcome index (P = 0.022).

CONCLUSION

This study shows that watch and wait is safe and effective outside of tertiary referral centres. It suggests that an opportunistic cCR is durable and when mucosal regrowth occurs it can be salvaged. Finally, we have shown that quality of life is probably improved if a watch and wait approach is adopted.

High body mass index and sleep problems during pregnancy: A meta-analysis and meta-regression of observational studies

Despite the well-established correlation of weight and sleeping problems, little is known about the nature of the association. The present study examined whether pregnant women with high body mass index have a risk of developing sleep problems, and identified any covariates that affect this relationship. We systematically searched electronic databases, specialized journals, various clinical trial registries, grey literature databases and the reference list of the identified studies. All observational studies were obtained from inception until 9 August 2020. The Newcastle-Ottawa Scale was adopted to assess the quality of studies. Stata software was used to conduct meta-analysis and meta-regression. Forty-six observational studies involving 2,240,804 participants across 16 countries were included. Quality assessment scores ranged from 4 to 10 (median = 6). Meta-analyses revealed that the risk of sleep apnea, habitual snoring, short sleep duration and poor sleep quality is increased in pregnant women with high body mass index, but not for daytime sleepiness, insomnia or restless legs syndrome. Subgroup differences were detected on body mass index between different regions, nature of population, year of publication, age group and study quality. Random-effects meta-regression analyses showed that year and quality of publication were covariates on the relationships between pre-pregnant body mass index and sleep apnea risk. Our review shows that sleep apnea, habitual snoring, short sleep duration and poor sleep quality are important concerns for pregnant women with high body mass index. Developing screening and targeted interventions is recommended to promote efficacious perinatal care.

Novel technique using amplatzer AVP I stent in management for giant renal artery pseudoaneurysm

Renal artery pseudoaneurysm (RAP) is an uncommon vascular lesion. Early detection and treatment of renal artery pseudoaneurysm is important because it can rupture and lead to life-threatening hemorrhage. Recent advances in endovascular interventions can prevent potentially challenging open surgery. We describe a case 66 year old patient who presented with a painful abdominal lumbar mass. CT scan show a giant renal artery pseudoaneurysm. We discuss management of giant renal artery pseudoaneurysm, both open surgery and endovascular surgery. Endovascular arterial embolization and stent techniques is feasible. However, open surgical treatment remains to be most effective and radical method in emergency setting.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

P252 Identifying predictors for all-cause mortality at admission, 1 and 3 years after admission for acute decompensated heart failure amongst patients with atrial fibrillation

Background

Heart failure (HF) and atrial fibrillation (AF) commonly co-exist, each, predisposing the other. AF may inflict haemodynamic disturbances, leading to reduced cardiac output and hence acute decompensation. Ultimately mortality risk is further increased. Identifying contributing factors is thus vital lest increasing risk of poor outcome.

Purpose

Identify predictors of all-cause mortality in AF patients after admission for acute decompensation HF (ADHF) at admission, 1 and 3 years. 

Methods

A retrospective observational study of 810 AF patients" first admission from 2009 to 2018, analysed using descriptive, ROC curve and Cox regression.

Results

Mortality at admission, 1 and 3 years following ADHF were 5.1%, 14.4% and 40.5% respectively. Majority of AF patients were male (64.7%) but there was no significant statistical difference between gender with associated mortality during those timelines. Using multivariate analysis, predictors associated with increased in-hospital mortality were Hyponatraemia, Na < 135mmol/L (adjusted Odds Ratio, aOR 2.49; 95% Confidence Interval, CI 1.91-5.20; p0.015), Uric Acid ≥ 675 (aOR 2.75; CI 1.31-5.79; p0.008), Ejection Fraction, EF < 40% (aOR 3.93; CI 1.63-9.49; p0.002). Medications on admission associated with reduced inpatient mortality were Angiotensin Converting Enzyme inhibitor (ACEi) / Angiotensin Receptor Blocker (ARB) + Beta Blocker (BB) + Mineralocorticoid Receptor Antagonist (MRA) (aOR 0.07; CI 0.02-0.30; p < 0.001). At 1 year, multivariate analysis showed an associated increase in mortality when NTProBNP ≥ 7500pg/ml (adjusted Hazard Ratio, aHR 1.64; CI 1.02-2.65; p0.042) and Urea > 7mmol/L (aHR 1.86; CI 1.04-3.32, p0.036). Medications on discharge comprising ACEi/ARB + BB + MRA were the only combination that showed a reduction in mortality (aHR 0.23; CI 0.09-0.60; p0.003). At 3 years, background coronary artery disease (aHR 1.72; CI 1.09-2.71; p0.02), hypernatraemia, Na > 145mmol/L (aHR 14.89; CI 3.17-69.86; p0.001), EF < 40% (aHR 2.00; CI 1.28-3.12; p0.002) were associated with increased mortality. Medications on discharge namely ACEi/ARB (aHR 0.14; CI 0.03-0.70; p0.013), BB (aHR 0.23; CI 0.10-0.51; p < 0.001), ACEi/ARB + BB (aHR 0.16; CI0.06-0.41; p < 0.001), ACEi/ARB + MRA (aHR 0.34; CI 0.14-0.85; p0.021), BB + MRA (aHR 0.38; CI 0.17-0.83; p0.016), ACEi/ARB + BB + MRA (aHR 0.193; CI 0.09-0.43; p < 0.001) showed an associated reduction in mortality.

Conclusions

In this single centre study, patients with AF who presented with ADHF had a variety of mortality predictors that influence at different timelines. They had higher risk of inpatient mortality with hyponatraemia, hyperuricaemia and EF < 40%. Elevated NTProBNP and Urea levels seemed to have more effect on mortality at 1 year compared to 3 years. Having 3 disease-modifying heart failure medications at discharge exerted the most benefit up to 3 years of follow up.

Abstract P252 Figure.

Diastolic dysfunction grading, echocardiographic and electrocardiogram findings in 50 patients with apical hypertrophic cardiomyopathy

INTRODUCTION

Apical Hypertrophic Cardiomyopathy (Apical HCM) is an uncommon variant of hypertrophic cardiomyopathy, but it is relatively more common in Asian countries. This is a retrospective, non-randomised, single centre study of patients with Apical HCM focusing on their diastolic dysfunction grading, echocardiographic parameters and electrocardiograms (ECG).

METHODS

All Apical HCM patients coming for clinic visits at the Institut Jantung Negara from September 2017 to September 2018 were included. We assessed their echocardiography images, grade their diastolic function and reviewed their ECG on presentation.

RESULTS

Fifty patient were included, 82% (n=41) were males and 18% (n=9) females. The diastolic function grading of 37 (74%) patients were able to be determined using the updated 2016 American Society of Echocardiography (ASE) diastolic guidelines. Fifty percent (n=25) had the typical ace-ofspades shape left ventricle (LV) appearance in diastole and 12% (n=6) had apical pouch. All patients had T inversion in the anterior leads of their ECG, and only 52% (n=26) fulfilled the ECG left ventricular hypertrophy (LVH) criteria. Majority of our patients presented with symptoms of chest pain (52%, n=26) and dyspnoea (42%, n=21).

CONCLUSION

The updated 2016 ASE guideline makes it easier to evaluate LV diastolic function in most patients with Apical HCM. It also helps in elucidating the aetiology of dyspnoea, based on left atrial pressure. Clinicians should have a high index of suspicion for Apical HCM when faced with deep T inversion on ECG, in addition to a thick LV apex with an aceof- spades appearance during diastole.

Bubble dynamics and cavitation intensity in milli-scale channels under an ultrasonic horn

Under a vibrating ultrasonic horn device, intense cavitation occurs but is restricted to a small volume due to strong attenuation effects. In this study, milli-scale channels were introduced under the horn. The effect of this on the cavitation development and intensity within the channels were explored. High speed videography of up to 100,000 fps and acoustic signal acquisition through hydrophone were conducted. Cavitation intensity was observed to increase within the channels as compared to free field condition. Bubble density increased with a decrease in channel diameter and a rise in ultrasonic amplitude. Furthermore, an intriguing phenomenon of large bubble cluster formation near the channel exit (20 mm away from the horn surface) was detected. The oscillation behaviour of these clusters is dependent on both channel diameter and ultrasonic amplitude. At the maximum ultrasonic amplitude, the clusters reached maximum radiuses exceeding 3 mm and collapsed violently. Repetitive transient collapses near the exit region suggest that the introduction of milli-scale channels could extend the effective cavitation zone length and enhance the overall cavitation intensity under an ultrasonic horn.

Factors influencing physical inactivity among adults in Negeri Sembilan, Peninsular Malaysia

BACKGROUND

Physical inactivity remains the most important modifiable risk factor in preventing a variety of noncommunicable diseases (NCDs) and has been identified to be a risk factor for obesity, heart disease and cancers. This study examined the prevalence and factors associated with physical inactivity among the suburban adult population in Port Dickson district, Negeri Sembilan, Peninsular Malaysia.

MATERIAL AND METHODS

This was a community based crosssectional study involving 397 adult respondents conducted in February 2016. Data was collected by face-to-face interview using a structured questionnaire. Data regarding socio-demographic factors (age, gender, ethnicity, education level, marital status and monthly income, working hours), current behavioural stage of physical activity and perceived benefits and barriers to physical activity were collected. Physical activity measured using the International Physical Activity Questionnaire (IPAQ) with the cut-off point of less than 600 met-min per week was considered to be physically inactive.

RESULTS

The prevalence of physical inactivity among adult population was 36.3%. Factors significantly associated with physical inactivity included age, gender, marital status, working hours and current behavioural stage of physical activity.

CONCLUSION

Physical inactivity is high among the adult community in Negeri Sembilan district, Peninsular Malaysia and was strongly associated with age, gender, marital status, working hours and current behavioural stage of physical activity. It is important to identify individuals with physical inactivity and its associated factors early as this could severely affect the quality of life of the individuals.

Smart Home-based IoT for Real-time and Secure Remote Health Monitoring of Triage and Priority System using Body Sensors: Multi-driven Systematic Review

The Internet of Things (IoT) has been identified in various applications across different domains, such as in the healthcare sector. IoT has also been recognised for its revolution in reshaping modern healthcare with aspiring wide range prospects, including economical, technological and social. This study aims to establish IoT-based smart home security solutions for real-time health monitoring technologies in telemedicine architecture. A multilayer taxonomy is driven and conducted in this study. In the first layer, a comprehensive analysis on telemedicine, which focuses on the client and server sides, shows that other studies associated with IoT-based smart home applications have several limitations that remain unaddressed. Particularly, remote patient monitoring in healthcare applications presents various facilities and benefits by adopting IoT-based smart home technologies without compromising the security requirements and potentially large number of risks. An extensive search is conducted to identify articles that handle these issues, related applications are comprehensively reviewed and a coherent taxonomy for these articles is established. A total number of (n = 3064) are gathered between 2007 and 2017 for most reliable databases, such as ScienceDirect, Web of Science and Institute of Electrical and Electronic Engineer Xplore databases. Then, the articles based on IoT studies that are associated with telemedicine applications are filtered. Nine articles are selected and classified into two categories. The first category, which accounts for 22.22% (n = 2/9), includes surveys on telemedicine articles and their applications. The second category, which accounts for 77.78% (n = 7/9), includes articles on the client and server sides of telemedicine architecture. The collected studies reveal the essential requirement in constructing another taxonomy layer and review IoT-based smart home security studies. Therefore, IoT-based smart home security features are introduced and analysed in the second layer. The security of smart home design based on IoT applications is an aspect that represents a crucial matter for general occupants of smart homes, in which studies are required to provide a better solution with patient security, privacy protection and security of users' entities from being stolen or compromised. Innovative technologies have dispersed limitations related to this matter. The existing gaps and trends in this area should be investigated to provide valuable visions for technical environments and researchers. Thus, 67 articles are obtained in the second layer of our taxonomy and are classified into six categories. In the first category, 25.37% (n = 17/67) of the articles focus on architecture design. In the second category, 17.91% (n = 12/67) includes security analysis articles that investigate the research status in the security area of IoT-based smart home applications. In the third category, 10.44% (n = 7/67) includes articles about security schemes. In the fourth category, 17.91% (n = 12/67) comprises security examination. In the fifth category, 13.43% (n = 9/67) analyses security protocols. In the final category, 14.92% (n = 10/67) analyses the security framework. Then, the identified basic characteristics of this emerging field are presented and provided in the following aspects. Open challenges experienced on the development of IoT-based smart home security are addressed to be adopted fully in telemedicine applications. Then, the requirements are provided to increase researcher's interest in this study area. On this basis, a number of recommendations for different parties are described to provide insights on the next steps that should be considered to enhance the security of smart homes based on IoT. A map matching for both taxonomies is developed in this study to determine the novel risks and benefits of IoT-based smart home security for real-time remote health monitoring within client and server sides in telemedicine applications.

Echocardiographic and electrocardiographic presentations of patients with endomyocardial biopsy-proven cardiac amyloidosis

OBJECTIVE

Cardiac amyloidosis is under diagnosed and its prevalence is unknown. This is a retrospective, nonrandomised, single centre study of patients with endomyocardial biopsy-proven cardiac amyloidosis focusing on their echocardiographic and electrocardiogram (ECG) presentations. This is the first case series in Malaysia on this subject.

METHODS

We identified all of our endomyocardial biopsyproven cardiac amyloidosis patients from January 2010 to January 2018 and reviewed their medical records. All patients echocardiographic and ECG findings reviewed and analysed comparing to basic mean population value.

RESULTS

In total there are 13 biopsy-proven cardiac amyloidosis patients. All of the biopsies shows light chain (AL) amyloid. Majority of the patients (8, 61.5%) is male, and most of our patients (8, 61.5%) is Chinese. All seven patients on whom we performed deformation imaging have apical sparing pattern on longitudinal strain echocardiogram. Mean ejection fraction is 49.3%, (SD=7.9). All patients have concentric left ventricular hypertrophy and right ventricular hypertrophy. Diastolic dysfunction was present in all of our patients with nine out of 13 patients (69.2%) having restrictive filling patterns (E/A ≥2.0 E/e' ≥15). On electrocardiogram, 12 (92%) patients have prolonged PR interval (median 200ms, IQR 76.50ms) and 9 (69.2%) patients have pseudoinfarct pattern.

CONCLUSION

Echocardiography plays an important role in diagnosing cardiac amyloidosis. The findings of concentric left ventricular hypertrophy with preserved ejection fraction without increased in loading condition should alert the clinician towards its possibility. This is further supported by right ventricular hypertrophy and particularly longitudinal strain imaging showing apical sparing pattern.

Index of suspicion with appropriate timing of CT scan helps prevent missed diagnosis in urologic trauma

Ureteric and bladder injuries are uncommon, difficult to diagnose and rarely occur in isolation. Diagnosis is often delayed or missed at presentation. Therefore, high clinical suspicion and appropriate timing of computed tomography (CT) are of paramount importance. We report two cases (ureteropelvic junction avulsion and ruptured dome of bladder) whereby the presentations were subtle and would have been missed if not for high clinical suspicion. This article discusses the problems associated with these urologic injuries, as well as how to develop a high index of suspicion based on the pattern of anatomical disruption, mechanism of injury, physiological abnormality and comorbidity.

Electronic-based lifestyle interventions in overweight or obese perinatal women: a systematic review and meta-analysis

Electronic-based (e-based) lifestyle interventions provide potential and cost-effective delivery of remote interventions for overweight and obese perinatal women. To date, no meta-analysis has reported the efficacy of maternal and neonatal outcomes. Seven electronic databases were searched from inception up to July 13, 2016, including the Cumulative Index to Nursing and Allied Health Literature, Cochrane Library, EMBASE, ProQuest Dissertations and Theses, PsycINFO, PubMed and Scopus. Among the 1,145 studies retrieved, 14 randomized controlled trials were selected among 17 publications. The Cochrane risk of bias tool was used to appraise the quality assessment. The meta-analyses demonstrated a significant result for limiting gestational weight gain, losing postnatal weight in 1-2 months, increasing self-reported moderate and vigorous physical activity and reducing caloric intake using diet-related software. Our review shows that an e-based lifestyle intervention is an acceptable approach. The findings reveal the variability in intervention methods and provide limited conclusive evidence. Thus, future studies should examine the efficacy and essential components as well as the various approaches using optimal portions of in-person and phone sessions. Further evaluations comparing the effectiveness of different e-based lifestyle intervention approaches toward activity-related and diet-related outcomes are necessary.

Total percutaneous endovascular aneurysm repair (pEVAR): the initial experience in Hospital Kuala Lumpur

INTRODUCTION

There has been a paradigm shift in the treatment of AAA with the advent of endovascular aneurysm repair (EVAR). Rapid progress and evolution of endovascular technology has brought forth smaller profile devices and closure devices. Total percutaneous endovascular aneurysm repair (pEVAR) involves the usage of suture-mediated closure devices (SMCDs) at vascular access sites to avoid a traditional surgical cutdown.

MATERIALS AND METHODS

We retrospectively reviewed our experience of pEVAR between April 2013 and July 2014. Primary success of the procedure was defined as closure of a common femoral artery (CFA) arteriotomy without the need for any secondary surgical or endovascular procedure within 30 days.

RESULTS

In total there were 10 pEVAR cases performed in the study period, one case in Queen Elizabeth Hospital during visiting vascular service. Patients have a mean age of 73.4 year old (66-77 year old) The mean abdominal aortic size was 7.2 cm (5.6-10.0cm). Mean femoral artery diameter was 9.0 mm on the right and 8.9 mm on the left. Mean duration of surgery was 119 minutes (98- 153 minutes). 50% of patients were discharged at post-operative day one, 30%- day two and 20%- day three. Primary success was achieved in 9 patients (90%) or in 19 CFA closures (95%). No major complication was reported.

DISCUSSION

We believe that with proper selection of patients undergoing EVAR, pEVAR offers a better option of vascular access with shorter operative time, less post- operative pain, shorter hospital stay and minimises the potential complications of a conventional femoral cutdown.

Induced pluripotent stem cells from human hair follicle keratinocytes as a potential source for in vitro hair follicle cloning

Background

Human hair follicles are important for the renewal of new hairs and their development. The generation of induced pluripotent stem cells (iPSCs) from hair follicles is easy due to its accessibility and availability. The pluripotent cells derived from hair follicles not only have a higher tendency to re-differentiate into hair follicles, but are also more suited for growth in hair scalp tissue microenvironment.

Methods

In this study, human hair follicular keratinocytes were used to generate iPSCs, which were then further differentiated in vitro into keratinocytes. The derived iPSCs were characterised by using immunofluorescence staining, flow cytometry, and reverse-transcription PCR to check for its pluripotency markers expression.

Results

The iPSC clones expressed pluripotency markers such as TRA-1-60, TRA-1-81, SSEA4, OCT4, SOX2, NANOG, LEFTY, and GABRB. The well-formed three germ layers were observed during differentiation using iPSCs derived from hair follicles. The successful formation of keratioctyes from iPSCs was confirmed by the expression of cytokeratin 14 marker.

Discussion

Hair follicles represent a valuable keratinocytes source for in vitro hair cloning for use in treating hair balding or grafting in burn patients. Our significant findings in this report proved that hair follicles could be used to produce pluripotent stem cells and suggested that the genetic and micro-environmental elements of hair follicles might trigger higher and more efficient hair follicles re-differentiation.

Recognising sleep apnoea

Most people spend a third of their lives sleeping, and thus, sleep has a major impact on all of us. As sleep is a function and not a structure, it is challenging to treat and prevent its complications. Sleep apnoea is one such complication, with serious and potentially life-threatening consequences. Local studies estimate that about 15% of Singapore's population is afflicted with sleep apnoea. The resulting sleep fragmentation may result in poor quality of sleep, leading to daytime sleepiness. Sleep apnoea may also be the underlying cause of high blood pressure, memory loss, poor concentration and work performance, motor vehicle accidents, and marital problems. Evaluation involves a sleep study, followed by patient education, and an individualised step-wise management approach should be explored. Many patients will require follow-up for a long period of time, as management options may not offer a permanent cure; other contributory causes may arise at different phases of their lives, compounded by genetic and hormonal issues, ethnicity and the modern hazards of a fast-paced society.

Contextual crowd intelligence

Most data analytics applications are industry/domain specific, e.g., predicting patients at high risk of being admitted to intensive care unit in the healthcare sector or predicting malicious SMSs in the telecommunication sector. Existing solutions are based on "best practices", i.e., the systems' decisions are knowledge-driven and/or data-driven . However, there are rules and exceptional cases that can only be precisely formulated and identified by subject-matter experts (SMEs) who have accumulated many years of experience. This paper envisions a more intelligent database management system (DBMS) that captures such knowledge to effectively address the industry/domain specific applications. At the core, the system is a hybrid human-machine database engine where the machine interacts with the SMEs as part of a feedback loop to gather, infer, ascertain and enhance the database knowledge and processing. We discuss the challenges towards building such a system through examples in healthcare predictive analysis -- a popular area for big data analytics.

Chemopreventive potential of Annona muricata L leaves on chemically-induced skin papillomagenesis in mice

Annona muricata L (Annonaceae), commonly known as soursop has a long, rich history in herbal medicine with a lengthy recorded indigenous use. It had also been found to be a promising new anti-tumor agent in numerous in vitro studies. The present investigation concerns chemopreventive effects in a two-stage model of skin papillomagenesis. Chemopreventive effects of an ethanolic extract of A. muricata leaves (AMLE) was evaluated in 6-7 week old ICR mice given a single topical application of 7,12-dimethylbenza(α)anthracene (DMBA 100 μg/100 μl acetone) and promotion by repeated application of croton oil (1% in acetone/ twice a week) for 10 weeks. Morphological tumor incidence, burden and volume were measured, with histological evaluation of skin tissue. Topical application of AMLE at 30, 100 and 300 mg/kg significantly reduced DMBA/croton oil induced mice skin papillomagenesis in (i) peri-initiation protocol (AMLE from 7 days prior to 7 days after DMBA), (ii) promotion protocol (AMLE 30 minutes after croton oil), or (iii) both peri-initiation and promotion protocol (AMLE 7 days prior to 7 day after DMBA and AMLE 30 minutes after croton oil throughout the experimental period), in a dose dependent manner (p<0.05) as compared to carcinogen-treated control. Furthermore, the average latent period was significantly increased in the AMLE-treated group. Interestingly, At 100 and 300 mg/ kg, AMLE completely inhibited the tumor development in all stages. Histopathological study revealed that tumor growth from the AMLE-treated groups showed only slight hyperplasia and absence of keratin pearls and rete ridges. The results, thus suggest that the A.muricata leaves extract was able to suppress tumor initiation as well as tumor promotion even at lower dosage.

Serotonin availability in rat colon is reduced during a Western diet model of obesity

Constipation and slowed transit are associated with diet-induced obesity, although the mechanisms by which this occurs are unclear. Enterochromaffin (EC) cells within the intestinal epithelium respond to mechanical stimulation with the release of serotonin [5-hydroxytryptamine (5-HT)], which promotes transit. Thus our aim was to characterize 5-HT availability in the rat colon of a physiologically relevant model of diet-induced obesity. EC cell numbers were determined immunohistochemically in chow-fed (CF) and Western diet-fed (WD) rats, while electrochemical methods were used to measure mechanically evoked (peak) and steady-state (SS) 5-HT levels. Fluoxetine was used to block the 5-HT reuptake transporter (SERT), and the levels of mRNA for tryptophan hydroxylase 1 and SERT were determined by quantitative PCR, and SERT protein was determined by Western blot. In WD rats, there was a significant decrease in the total number of EC cells per crypt (0.86 ± 0.06 and 0.71 ± 0.05 in CF and WD, respectively), which was supported by a reduction in the levels of 5-HT in WD rats (2.9 ± 1.0 and 10.5 ± 2.6 μM at SS and peak, respectively) compared with CF rats (7.3 ± 0.4 and 18.4 ± 3.4 μM at SS and peak, respectively). SERT-dependent uptake of 5-HT was unchanged, which was supported by a lack of change in SERT protein levels. In WD rats, there was no change in tryptophan hydroxylase 1 mRNA but an increase in SERT mRNA. In conclusion, our data show that foods typical of a WD are associated with decreased 5-HT availability in rat colon. Decreased 5-HT availability is driven primarily by a reduction in the numbers and/or 5-HT content of EC cells, which are likely to be associated with decreased intestinal motility in vivo.

Ultrasound detection of colonic polyps: perspective

Colorectal cancer is often preventable if the precursor adenoma is detected and removed. Although ultrasound is clearly not one of the widely accepted screening techniques, this non-invasive and radiation-free modality is also capable of detecting colonic polyps, both benign and malignant. Such colon lesions may be encountered when not expected, usually during general abdominal sonography. The discovery of large colonic polyps is important and can potentially help reduce the incidence of a common cancer, whereas detection of a malignant polyp at an early stage may result in a curative intervention. This pictorial review highlights our experience of sonographic detection of colonic polyps in 43 adult patients encountered at our institutions over a 2-year period. 4 out of 50 discovered polyps were found to be malignant lesions, 3 polyps were hyperplastic, 1 polyp was a hamartomatous polyp and the rest were benign adenomas. The smallest of the detected polyps was 1.3 cm in diameter, the largest one was 4.0 cm (mean 1.7 cm; median 1.6 cm). In each case, polyps were discovered during a routine abdominal or pelvic examination, particularly when scanning was supplemented by a brief focused sonographic inspection of the colon with a 6-10 MHz linear transducer. In this paper, we illustrate the key sonographic features of different types of commonly encountered colonic polyps in the hope of encouraging more observers to detect these lesions, which may be subtle.

Synthesis of quaternary carbon centers via hydroformylation

The application of hydroformylation to the synthesis of quaternary carbon centers is reported. The synthesis of the highly substituted carbon is achieved by applying a catalytic amount of 1. Ligand 1 serves as a catalytic directing group by covalently and reversibly binding to both the substrate and catalyst. The intramolecular nature of the directing group strategy accelerates the hydroformylation reaction such that the reaction is performed at mild temperatures (35-55 degrees C) and with excellent regioselectivity (b:l > 94:6).

A framework to enforce access control over data streams

Although access control is currently a key component of any computational system, it is only recently that mechanisms to guard against unauthorized access to streaming data have started to be investigated. To cope with this lack, in this article, we propose a general framework to protect streaming data, which is, as much as possible, independent from the target stream engine. Differently from RDBMSs, up to now a standard query language for data streams has not yet emerged and this makes the development of a general solution to access control enforcement more difficult. The framework we propose in this article is based on an expressive role-based access control model proposed by us. It exploits a query rewriting mechanism, which rewrites user queries in such a way that they do not return tuples/attributes that should not be accessed according to the specified access control policies. Furthermore, the framework contains a deployment module able to translate the rewritten query in such a way that it can be executed by different stream engines, therefore, overcoming the lack of standardization. In the article, besides presenting all the components of our framework, we prove the correctness and completeness of the query rewriting algorithm, and we present some experiments that show the feasibility of the developed techniques.

Prevalence of onodi cells in hospital raja permaisuri bainun, ipoh, malaysia

INTRODUCTION

Onodi cell is a posterior ethmoid air cell that pneumatizes into the sphenoid sinus, It is an important entity for clinicians when performing endoscopic sinus surgery (EES) because it encroaches into the optic nerve and internal carotid artery. CT-scans are the road map for ESS to prevent damage to structures mentioned above. Its prevalence in Malaysia is unknown.

METHOD

102 CT-scans of paranasal sinuses dated from 2006- 2009 in Hospital Raja Permaisuri Bainun (HRPB), Ipoh, Malaysia were studied by Consultant Rhinologist (HS). The Onodi Cells were recorded as present on the left side, right side or bilaterally.

RESULTS

A total of 59 males and 43 females with a mean age of 42 were studied. Twenty of the scans were noted to have Onodi cells. Of those with Onodi present, 5 were females and 15 were males; 9 of them had sinusitis and 11 had nasal polyposis. None of them were noted to have complications related to the Onodi cells. There were 6 with left side involvement, 7 with right side involvement and 7 with bilateral Onodi cells.

CONCLUSION

A prevalence of 19.6% was noted in the patients in HRPB, Ipoh, corresponding to other CT-scan studies ranging from 7-24%. The presence of Onodi cells should be routinely looked for by ESS surgeons to prevent damaging the optic nerve and internal carotid artery.

The prevalence and characteristics associated with mother-infant bed-sharing in Klang district, Malaysia

This was a cross-sectional study to determine the prevalence and characteristics of mother-infant bed-sharing practice in Klang district, Malaysia. Data was collected by face-to-face interview using a structured questionnaire for a four month period in 2006. A total of 682 mother-infant pairs attending government health clinics were included in the study. Data regarding socio-demographic characteristics of the mothers, information on the infants, bed-sharing and breastfeeding practices were collected. The mean maternal age was 28.4 +/- 5.1 years while the mean infant gestational age was 38.8 +/- 1.8 weeks. The study showed the prevalence of bed-sharing was 73.5% (95% CI: 70.0, 76.7). In multivariate analysis; area of interview, maternal occupation, family income, breastfeeding and infant birth weight were associated with bed-sharing after adjusted for maternal ethnicity, age, marital status, educational level, parity, infant gender and infant gestational age. In conclusion, bed-sharing is a common practice in Klang district, Malaysia, not specific to ethnicity, but strongly associated with low family income and breastfeeding.

Expression of cyclooxygenase-1/-2, microsomal prostaglandin-E synthase-1 and E-prostanoid receptor 2 and regulation of inflammatory mediators by PGE(2) in the amoeboid microglia in hypoxic postnatal rats and murine BV-2 cells

This study aimed to investigate the effect of hypoxia on the expression of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), microsomal prostaglandin-E synthase (mPGES-1), E-prostanoid receptor 2 (EP2) in microglia; and the roles of EP2-cyclic adenosine monophosphate (cAMP) signaling pathway in the prostaglandin E(2) (PGE(2)) regulation of inflammatory mediators released by hypoxic BV-2 cells. Immunoexpression of COX-1, COX-2, mPGES-1 and EP2 was localized in the amoeboid microglial cells (AMC), a nascent brain macrophage in the developing brain, as confirmed by double labeling with OX-42 and lectin, specific markers of microglia. AMC emitted a more intense immunofluorescence in hypoxic rats when compared with the matching controls. In postnatal rats subjected to hypoxia, mRNA and protein expression levels of COX-1, COX-2 and mPGES-1 along with tumor necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), inducible nitric-oxide synthase (iNOS) and PGE(2) product in the callosal tissue were significantly increased. The results were shared in the BV-2 cells except for COX-1 mRNA and protein whose levels remained unaltered. Interestingly, treatment with EP2 antagonist AH-6809 resulted in suppression of hypoxia induced EP2, IL-1beta and iNOS mRNA and protein expression, TNF-alpha protein expression and intracellular cAMP level in BV-2 cells. It is suggested that PGE(2) may regulate above inflammatory mediators in the activated microglia via EP2-cAMP signaling pathway in hypoxic conditions.

Factors Associated with Non-exclusive Breastfeeding among 4-Week Post-partum Mothers in Klang District, Peninsular Malaysia

This is a cross-sectional study which investigated the association between non-exclusive breastfeeding and maternal, paternal, obstetric and infant factors. Data on maternal, paternal, obstetric and infant factors were collected through face-to-face interview using a structured questionnaire from 498 mothers with four-week-old infants who attended government clinics in Klang district between 17 and 28 July 2006. The prevalence of non-exclusive breastfeeding at four weeks was 45.8%. Factors significantly associated with non-exclusive breastfeeding at four weeks included Indian ethnic mother (OR = 4.06), working mother (OR = 3.55), mother from high household income (OR = 1.90), mother who smokes (OR = 7.27), primiparous (OR = 1.97), infant not sharing a bed with mother (OR = 1.75) and infant born prematurely (OR = 7.69). Identification of risk factors should assist in targeting women who are at increased risk of non-exclusive breastfeeding.

Serrated and non-serrated polyps of the colorectum: their prevalence in an unselected case series and correlation of BRAF mutation analysis with the diagnosis of sessile serrated adenoma

AIMS

To determine the prevalence of colorectal polyps of different types in an unselected population, and to correlate the morphological diagnoses with BRAF mutation analysis.

METHODS

Cases of colorectal polyps diagnosed at endoscopy were retrieved from the files of Southern.IML Pathology. All slides were reviewed and the lesions classified histologically. A diagnosis of sessile serrated adenoma was made even if the characteristic features were present only focally. If there was more than one polyp of a particular type in any patient, one lesion was chosen at random so that the results represent the number of patients with each type of polyp rather than the total number of polyps. A proportion of the polyps was subjected to BRAF mutation analysis.

RESULTS

A total of 1479 patients were identified. Non-serrated ("conventional") adenomas were found in 964 patients (65%), hyperplastic polyps in 437 (30%), sessile serrated adenomas in 57 (3.9%), traditional serrated adenomas in 11 (0.7%) and mixed hyperplastic adenomatous polyps in 10 (0.7%). BRAF V600E mutation analysis was performed in 148 selected cases; mutations were found in 44/49 (90%) of lesions diagnosed as sessile serrated adenoma, in 10/34 (29%) of hyperplastic polyps of microvesicular type, in 4/11 (36%) of traditional serrated adenomas, in 10/10 (100%) of mixed hyperplastic adenomatous polyps, and in 2/42 (5%) of "conventional" adenomas.

CONCLUSIONS

Sessile serrated adenomas are encountered commonly in routine endoscopy practice. The histological diagnosis correlates strongly with the presence of BRAF mutation.

Assessing the development of children with disability in Malaysia

This is a cross-sectional study investigating the profile of children with disability registered with the primary health care clinics in Malaysia. The purpose of the study was to assess the developmental stage of children with disability. Secondary data from the pilot project conducted by the Family Health Development Division, Ministry of Health Malaysia was used in this study. The study period was for six months from 1st August 2004 until 31st January 2005. A total of 900 disabled children were selected in this study. Schedule of Growing Scale (SGS) II was used for analysis. Results showed more boys than girls were affected with a ratio of 6:4. The mean total SGS score increases as the age of the child increased. The score was highest in delayed speech cases and lowest in cerebral palsy cases. The performance among children with delayed speech was the highest while children with cerebral palsy were the lowest. There was a statistically significant difference between the major ethnic groups in delayed speech and attention deficit hyperactive disorder.

Alpha-thalassaemia in association with beta-thalassaemia patients in Malaysia: a study on the co-inheritance of both disorders

BACKGROUND/AIMS

Individuals with double heterozygosity for alpha- and beta-thalassaemia and heterozygous beta-thalassaemia show a similar haematological picture. Co-inheritance of alpha- and beta-thalassaemia in both partners may result in pregnancies with either Hb Bart's hydrops foetalis or beta-thalassaemia major, or pregnancies with both disorders.

METHODS

The co-inheritance of alpha-thalassaemia in 322 beta-thalassaemia carriers in Malaysia was studied.

RESULTS

The frequency of alpha-thalassaemia in the beta-thalassaemia carriers was 12.7% (41/322), with a carrier frequency of 7.8% for the SEA deletion, 3.7% for the -alpha(3.7) deletion, 0.9% for Hb Constant Spring and 0.3% for the -alpha(4.2) deletion.

CONCLUSION

Double heterozygosity for alpha- and beta-thalassaemia was confirmed in 5 out of the 41 couples and the risk of the fatal condition Hb Bart's hydrops foetalis was confirmed in two of these couples. Detection of the Southeast Asian (SEA) deletion in the Malaysian Malays in this study confirms that Hb Bart's hydrops foetalis can occur in this ethnic group. Results of this study have provided new information on the frequency and different types of alpha-thalassaemia (--(SEA), -alpha(3.7) and -alpha(4.2) deletions, Hb Constant Spring) in Malaysian beta-thalassaemia carriers.

Reassessment on the development of children with disability in Malaysia

This is a cohort study investigating the profile of children with disability registered with the primary health care clinics in Malaysia. The purpose of the study was to determine whether reassessment on the development of children with disability under rehabilitation should be done at three months interval or six months interval. Secondary data from the pilot project conducted by the Family Health Development Division, Ministry of Health Malaysia was used in this study. The study was carried out for seven months from 1st August 2004 until 28th February 2005. A total of 168 disabled children followed up for six months were selected in this study. Schedule of Growing Scale (SGS) II was the tool used for analysis. Results showed a statistically significant difference in the mean total SGS score at six months interval but not at three months interval. The result suggests that reassessment on children with Down Syndrome, Autism, Cerebral Palsy, mental retardation and delayed speech under rehabilitation should be carried out every six months while children with gross developmental delay and slow learner might need a longer interval for reassessment.

Endovascular stent graft treatment of leaking thoracic aortic tuberculous pseudoaneurysm

Mycobacterium tuberculosis infection is one of the leading causes of death from communicable diseases worldwide. However, the incidence of leaking thoracic aortic tuberculous pseudoaneurysms is rare as a complication. Conventional treatment of a leaking tuberculous pseudoaneurysm involves surgery with graft interposition or patch repair. With the emergence of stent graft treatment as a viable option for leaking pseudoaneurysms, we report a 63-year-old man who had his leaking toracic aortic tuberculous pseudoaneurysm treated with endovascular stent grafting.

Something not quite right: Gardner syndrome diagnosed by multiple cutaneous lesions and genetic testing

Gardner syndrome is a variant of familial adenomatous polyposis characterized by intestinal adenomatous polyps, which can progress to adenocarcinoma, and a variety of extraintestinal manifestations, including skin cysts, osteomas, soft tissue fibrous tumours and a characteristic ocular lesion. The extraintestinal manifestations are often the presenting feature but are usually not sufficiently characteristic on their own to trigger recognition of the syndrome. We report a case of a 17-year-old female who had been treated by a number of specialists over a 13-year period for a variety of cutaneous lesions without a hereditary condition being suspected. Gardner syndrome was considered only after excision of subcutaneous fibrous tumours from the mastoid region and paraspinal area and was confirmed by genetic testing in spite of the patient's refusal to undergo colonic endoscopic examination. Subsequent resection revealed approximately 70 adenomatous colonic polyps in the colon and rectum but no invasive tumour, highlighting the benefits of genetic testing in treatment planning.

Characterisation of beta-globin gene mutations in Malaysian children: a strategy for the control of beta-thalassaemia in a developing country

beta-thalassaemia major, an autosomal recessive hemoglobinopathy, is one of the most common single gene disorders in multi-racial Malaysia. The control of beta-thalassaemia major requires a multi-disciplinary approach that includes population screening, genetic counselling, prenatal diagnosis and the option of termination of affected pregnancies. To achieve this objective, the molecular characterisation of the spectrum of beta-globin gene mutations in each of the affected ethnic groups is required. We studied 88 consecutive unrelated individuals and their respective families with beta-thalassaemia (74 beta-thalassaemia major, 12 HbE-beta-thalassaemia, 2 with HbE homozygotes) and four individuals with beta-thalassaemia trait that contributed a total 180 alleles for study. Using a 2-step molecular diagnostic strategy consisting of amplification refractory mutation system (ARMS) to identify the 8 most common mutations followed by other DNA-based diagnostic techniques, a total of 177 (98.3 per cent) of the 180 beta-thalassaemia alleles were characterised. One out of 91 (1 per cent) of the Chinese alleles, one out of 46 (2.2 per cent) Malay alleles and one out of two Indian alleles remained unknown. A 100 per cent success rate was achieved in studying the Kadazandusun community in this study. A strategy to identify beta-globin gene mutations in Malaysians with beta-thalassaemia is proposed based on this outcome.

Rapid and cost-effective antenatal diagnosis of haemoglobin Bart's hydrops foetalis syndrome using a duplex-polymerase chain reaction

Haemoglobin Bart's hydrops foetalis syndrome (--SEA/--SEA) is not compatible with life and contributes to a majority of the hydropic foetuses in the Malaysian Chinese alpha-thalassaemia carriers who possess the 2-alpha-gene deletion in cis (--SEA/alphaalpha). A duplex-PCR which simultaneously amplifies a normal 136 bp sequence between the psialpha-alpha2-globin genes and a 730 bp Southeast Asian deletion-specific sequence (--SEA) between the psialpha2-theta1-globin genes was established. The duplex-PCR which detects the --SEA deletion in both chromosomes serves as a rapid and cost-effective confirmatory test in the antenatal diagnosis of Haemoglobin Bart's hydrops foetalis syndrome in Malaysia. In addition, the duplex-PCR is simple to perform as both the normal and deletion-specific alpha-globin gene sequences are amplified in the same PCR reaction.

Identification and characterization of mErk5-T, a novel Erk5/Bmk1 splice variant

Extracellular regulated kinase 5 (ERK5) is an unusually large member of the MAP kinase family of signaling molecules that plays an important role in cellular proliferation, differentiation and survival. Recently, three transcriptional variants of murine Erk5 were described (mErk5-a, -b and -c) that result from alternate splicing across introns 1 and/or 2, the net effect of which is translation of a peptide that lacks the kinase domain. It has been demonstrated that expression of mErk5-b and -c impinge on the function of the full length mErk5 protein product via a dominant negative effect. Here, we report the identification of another murine Erk5 splice variant and the orthologous human transcript that arise due to alternate splicing of intron 4. Failure to splice out intron 4 introduces a premature in-frame stop codon that directs translation of a peptide lacking the nuclear localization signal (NLS) and proline-rich region (PR). Experimental characterization demonstrated that like mERK5, mERK5-T becomes phosphorylated by co-expression with a constitutively active mMEK5 (mMEK5DD), and is able to coimmunoprecipitate with both itself and mERK5. Unlike mERK5, however, activated ERK5-T is unable to translocate from the cytoplasm to the nucleus in HeLaS3 cells, causing the retention of active mERK5 in the cytoplasm. Taken together with previous reports of domain content modification of ERK5 via alternate splicing, these observations add to the suggestion that regulation of ERK5 signaling may be mediated, at least in part, at the level of RNA processing.

Migrating esophageal foreign bodies

Ingested foreign bodies which migrate extraluminally, although rare in occurrence, are fraught with the potential to cause life-threatening complications.

PURPOSE OF THE STUDY

To discuss the management of this pathology.

MATERIAL AND METHODS

A series of four patients with such occurrences is presented.

CONCLUSION

A discussion on the safe management of such seemingly innocuous foreign bodies allows the authors to propose a therapeutical algorythm.

Molecular defects in the β-globin gene identified in different ethnic groups/populations during prenatal diagnosis for β-thalassemia: a Malaysian experience

Beta-thalassemia is the most-common genetic disorder of hemoglobin synthesis in Malaysia, and about 4.5% of the population are heterozygous carriers of the disorder. Prenatal diagnosis was performed for 96 couples using the Amplification Refractory Mutation System and Gap-Polymerase Chain Reaction. We identified 17 beta-globin defects-initiation codon for translation (T-G), -29 (A-G), -28 (A-G), CAP +1 (A-C), CD 8/9 (+G), CD 15 (G-A), CD 17 (A-T), CD 19 (A-G), Hb E (G-A), IVS1-1 (G-T), IVS1-5 (G-C), CD 41/42 (-CTTT), CD 71-72 (+A), IVS2-654 (CT), poly A(A-G), 100-kb Ggamma(Agammadeltabeta) degrees and 45-kb Filipino deletions. The 192 beta-alleles studied comprised Chinese (151 patients), Malay (21), Orang Asli from East Malaysia (15), Filipino (1), Indian (1), Indonesian Chinese (2), and Thai (1). In the Chinese, 2 beta-globin defects at CD 41/42 and IVS2-654 were responsible for 74% of beta-thalassemia. beta-mutations at CD 19, IVS1-1 (G-T), IVS1-5, poly A, and hemoglobin E caused 76% of the hemoglobin disorders in the Malays. The Filipino 45-kb deletion caused 73.3% of bthalassemia in the Orang Asli. Using genomic sequencing, the rare Chinese beta-mutation at CD 43 (G-T) was confirmed in 2 Chinese, and the Mediterranean mutation IVS1-1 (G-A) was observed in a Malay beta-thalassemia carrier. The beta-globin mutations confirmed in this prenatal diagnosis study were heterogenous and 65 (68%) couples showed a different globin defect from each other. The use of specific molecular protocols has allowed rapid and successful prenatal diagnosis of beta-thalassemia in Malaysia.

Simple aspiration versus chest-tube insertion in the management of primary spontaneous pneumothorax: a systematic review

BACKGROUND

The initial treatment of a primary spontaneous pneumothorax (PSP) is controversial. Guidelines of the British Thoracic Society recommend simple aspiration for all PSP requiring intervention. The placement of chest tubes is only advocated for patients who fail simple aspiration. However, the American College of Chest Physicians Delphi Consensus Statement found simple aspiration to be rarely appropriate in the management of PSP.

AIMS

To compare simple aspiration with chest-tube drainage in the initial management of PSP.

METHODS

Meta-analysis of randomized controlled trials (RCTs).

OUTCOME MEASURES

Reductions in duration of hospital stay, recurrence rate and pain or dyspnoea score were classified as benefits, whereas reductions in successful events were classified as risks.

DATA COLLECTION AND ANALYSIS

For dichotomous data, the relative risk (RR) and 95% confidence intervals were calculated. For continuous data, weighted mean differences (WMD) were used.

RESULTS

Three RCTs were identified with a combined total of 194 patients. Simple aspiration was associated with shorter hospitalization (WMD -1.30 days [-2.20 to -0.39]). The results for success rate could not be combined because of differences in outcome definitions. However, a pooled result for "success at 1 week or more" showed no significant difference between either intervention (RR 0.86 [0.67, 1.11]). Results of recurrence at 1 year were also not significantly different (RR 0.73 [0.39-1.38]). Different reporting systems for pain scores meant that data could not be pooled. Only one trial reported dyspnoea scores.

CONCLUSION

RCT evidence in this field is limited, and the total sample size is too small to make any firm conclusion. On the basis of current available evidence, simple aspiration is advantageous in the initial management of PSP because of shorter hospitalization. There is no significant difference in recurrence at 1 year using either modality, and the efficacy data are inconclusive.

A case report of occupational asthma due to gluteraldehyde exposure

INTRODUCTION

We report the first case of occupational asthma due to gluteraldehyde exposure in Singapore and also describe the use of a specific inhalational challenge (SIC) test in confirming the diagnosis.

CLINICAL PICTURE

A 32-year-old laboratory technician presented with adult-onset asthma 2 years after daily exposure to gluteraldehyde which was used to sterilise the mouthpieces used for lung function testing. SIC testing showed a 25% drop in FEV1 after exposure to gluteraldehyde but not after exposure to a control, thus confirming the diagnosis.

TREATMENT

Alternative arrangements were made for sterilisation of the mouthpieces so that gluteraldehyde could be removed from the workplace. There was a marked improvement in her asthmatic control thereafter.

CONCLUSIONS

This case illustrates the use of a SIC test in the diagnosis of occupational asthma. Gluteraldehyde is a known cause of occupational asthma and should be kept in mind when evaluating asthmatic patients in at-risk occupations. Effective ventilation and proper storage should be ensured to minimise exposure to gluteraldehyde where its use is necessary.

Transcutaneous bilirubinometry during and after phototherapy

AIM

To evaluate the reliability of transcutaneous bilirubinometry (TcB) during and after phototherapy.

METHODS

TcB was performed on the forehead and chest of infants with neonatal jaundice when capillary blood was sampled for bilirubin determination in a control group of 240 neonates. In a second group of 70 neonates exposed to phototherapy the same procedure was performed after at least 24 h of exposure: on the forehead, TcB was done in the centre of the unexposed area and also on the adjacent exposed area, and the exposed chest. During the post-phototherapy period, TcB was again done during the first and second days, at least 18-24 h after cessation of phototherapy. The results were then statistically evaluated and regression curves were plotted.

RESULTS

A close correlation between TcB values and bilirubin levels was observed in the control group. In the phototherapy group, a correlation was also found between the TcB and the bilirubin values, but this correlation was significantly poorer than that of the controls; the correlation for the covered part of the forehead was significantly better than that of the exposed part but still poorer than that of the controls, though the difference was no longer significant. Skin colour recovered during the post-phototherapy period and correlation was better than that during exposure and no longer significantly different from that of the controls.

CONCLUSION

Through its bleaching effect on the skin, phototherapy affects the correlation between TcB and the bilirubin values, but does not totally eliminate it. The unexposed parts show a better correlation, though this was still poorer than that of the controls. Recovery of skin colour occurred within 18-24 h after cessation of exposure.

Boerhaave's syndrome presenting as a right-sided pleural effusion

INTRODUCTION

Boerhaave's syndrome is an uncommon condition where there is oesophageal rupture following forceful vomiting, subsequent mediastinitis and is associated with high mortality and morbidity in the absence of therapy. We present a case of Boerhaave's syndrome in a 79-year-old woman who developed a right-sided effusion, an unusual presentation.

CLINICAL PICTURE

A 79-year-old woman developed a right-sided empyema and mediastinitis after a bout of repeated vomiting. Gastrograffin swallows and oesophago-gastroduodenoscopy confirmed oesophageal rupture.

TREATMENT

The patient was treated with antibiotics and a tube thoracostomy. An open thoracotomy, oesophagostomy and thoracic window was subsequently performed.

OUTCOME

The oesophageal rupture was contained but patient died from postoperative complications.

CONCLUSIONS

Physicians should have a high index of suspicion of oesophageal rupture when patients present with Meckler's triad of symptoms and especially when pleural fluid cultures grow bacteria native to the gastrointestinal tract.

Malignant mesothelioma: experience at the Singapore General Hospital

INTRODUCTION

Malignant mesothelioma is a rare occupational disease in Singapore. There have been few reports of this condition in Singapore. We aim to describe the clinical characteristics, management and outcomes in a case series of 16 patients diagnosed in a teaching hospital in Singapore.

MATERIALS AND METHODS

A chart review of all cases of malignant mesothelioma diagnosed in our institution during the period 1996 to 2001 was conducted, with particular attention to the occupational history.

RESULTS

There were 16 patients (15 male patients) with a median age of 61.5 (range, 46 to 78) years. Thirteen patients had malignant pleural mesothelioma (MPM) and 3 patients had mesothelioma of the periotoneum. Eleven of the patients with MPM (84.6%) presented with a pleural effusion and only 2 patients (15.4%) had chest pain. Initial pleural fluid cytology and closed pleural biopsies were negative in all patients who presented with a pleural effusion. Thoracoscopy confirmed the histologic diagnosis and allowed simultaneous talc pleurodesis in 9 patients. All patients had documented asbestos exposure, of which 14 (87.5%) were confirmed to be occupationally related. The median time from first exposure to symptoms was 33.5 (range, 16 to 53) years. The median survival was 6 months. Most of the patients (75%) received best supportive care alone.

CONCLUSIONS

In our experience, malignant mesothelioma is an aggressive disease with a poor prognosis. It is strongly associated with asbestos exposure. Thoracoscopy is an invaluable diagnostic modality in the evaluation of a patient with occupational asbestos exposure and an undiagnosed pleural effusion.

Reactive coupling of poly(ethylene glycol) on electroactive polyaniline films for reduction in protein adsorption and platelet adhesion

Poly(ethylene glycol) (PEG)-coupled polyaniline (PANI) film surfaces were prepared by incorporating the chlorinie end-capped methoxy PEG (mPEGCl) of molecular weight of about 2000 onto the emeraldine (EM) base form of PANI via N-alkylation. The microstructure and composition of the mPEG-coupled PANI (mPEG-c-PANI) surfaces were characterized by atomic force microscopy, contact angle measurement and X-ray photoelectron spectroscopy. The concentration of surface-coupled mPEG increased with the increase in concentration of the mPEGCl solution. The mPEG-c-PANI film surfaces exhibited enhanced ability to repel protein adsorption, with only an moderate reduction in their electrical conductivity. The mPEG-c-PANI surface with a high concentration of coupled mPEG also exhibited good resistance towards platelet adhesion.

Combine-ARMS: a rapid and cost-effective protocol for molecular characterization of beta-thalassemia in Malaysia

Beta-thalassemia major patients have chronic anemia and are dependent on blood transfusions to sustain life. Molecular characterization and prenatal diagnosis of beta3-thalassemia is essential in Malaysia because about 4.5% of the population are heterozygous carriers for beta-thalassemia. The high percentage of compound heterozygosity (47.62%) found in beta-thalassemia major patients in the Thalassaemia Registry, University of Malaya Medical Centre (UMMC), Malaysia, also supports a need for rapid, economical, and sensitive protocols for the detection of beta-thalassemia mutations. Molecular characterization of beta-thalassemia mutations in Malaysia is currently carried out using ARMS, which detects a single beta-thalassemia mutation per PCR reaction. We developed and evaluated Combine amplification refractory mutation system (C-ARMS) techniques for efficient molecular detection of two to three beta-thalassemia mutations in a single PCR reaction. Three C-ARMS protocols were evaluated and established for molecular characterization of common beta-thalassemia mutations in the Malay and Chinese ethnic groups in Malaysia. Two C-ARMS protocols (cd 41-42/IVSII #654 and -29/cd 71-72) detected the beta-thalassemia mutations in 74.98% of the Chinese patients studied. The CARMS for cd 41-42/IVSII #654 detected beta-thalassemia mutations in 72% of the Chinese families. C-ARMS for cd 41-42/IVSI #5/cd 17 allowed detection of beta-thalassemia mutations in 36.53% of beta-thalassemia in the Malay patients. C-ARMS for cd 41-42/IVSI #5/cd 17 detected beta-thalassemia in 45.54% of the Chinese patients. We conclude that C-ARMS with the ability to detect two to three mutations in a single reaction provides more rapid and cost-effective protocols for beta-thalassemia prenatal diagnosis and molecular analysis programs in Malaysia.

Surface modification of stainless steel by grafting of poly(ethylene glycol) for reduction in protein adsorption

The surface of stainless steel was first modified by the silane coupling agent (SCA), (3-mercaptopropyl)trimethoxysilane. The silanized stainless-steel surface (SCA-SS surface) was subsequently activated by argon plasma and then subjected to UV-induced graft polymerization of poly(ethylene glycol)methacrylate (PEGMA). The chemical structures and composition of the pristine, silane-treated, plasma-treated and PEGMA graft-polymerized stainless-steel coupon surfaces were characterized by X-ray photoelectron spectroscopy (XPS) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. The graft polymerization of PEGMA onto the plasma-pretreated SCA-SS surface was studied with different argon plasma pretreatment time, macromonomer concentration, and UV graft polymerization time. In general, a brief plasma pretreatment, high PEGMA concentration, and long UV graft polymerization time readily resulted in a high graft concentration. The PEGMA graft-polymerized stainless-steel coupon (PEGMA-g-SCA-SS) with a high graft concentration, and thus a high PEG content, was found to be very effective in preventing bovine serum albumin and gamma-globulin adsorption.

Surface modification of natural rubber latex films via grafting of poly(ethylene glycol) for reduction in protein adsorption and platelet adhesion

Natural rubber (NR) latex films with surface grafted poly(ethylene glycol) (PEG) chains were prepared by UV-induced graft copolymerization of methoxy poly(ethylene glycol) monomethacrylate (PEGMA) onto the plasma-pretreated NR latex films. PEGMA macromononers of different molecular weights were used. The UV-induced graft copolymerization of PEGMA onto the plasma-pretreated NR latex films was also explored with PEGMA of different macromonomer concentrations and with different UV graft copolymerization time. The surface microstructures and compositions of the PEG-modified NR latex films were characterized by contact angle, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) measurements. In general, higher macromonomer concentration and longer UV graft copolymerization time led to a higher graft yield. Water contact angle measurements revealed that the hydrophilicity of the NR latex film surface was greatly enhanced by the grafting of the PEG chains. The NR surface with a high density of grafted PEG was very effective in reducing protein adsorption and platelet adhesion. A lower graft concentration of the high-molecular-weight PEG was more effective than a high graft concentration of the low-molecular-weight PEG in reducing protein adsorption and platelet adhesion.

Dynamic holography for optical interconnections. I. Noise floor of low-cross-talk holographic switches

Reconfigurable optical interconnects constructed by recording dynamic holograms onto spatial light modulators may be crucial elements in all-optical networks. The extremely low cross-talk level of such free-space holographic switches was shown by an analytic approximation and verified experimentally. The fiber-to-fiber switch utilizes the spatial filtering properties of single-mode fibers, and its cross-talk noise is limited to the sidelobe power as a result of diffraction of the clipped Gaussian beam at the hologram aperture edges, provided that all higher orders are avoided. Greater than 45-dB cross-talk isolation has been measured at transverse-axis locations, and locating a fiber port at off-transverse-axis directions promises to double this level if aberrations are negligible.

Modification of Si(100) surface by the grafting of poly(ethylene glycol) for reduction in protein adsorption and platelet adhesion

The modification of argon plasma-pretreated single-crystal Si(100) wafer surfaces via the UV-induced graft polymerization of poly(ethylene glycol) methacrylate (PEGMA) macromonomer (molecular weight approximately 340) for biomaterials applications was explored. The modified Si(100) surfaces were characterized by X-ray photoelectron spectroscopy and atomic force microscopy. Surface peroxide concentrations resulting from the argon plasma treatment and subsequent atmospheric exposure were determined by a coupling reaction with diphenylpicrylhydrazyl. The results suggested that a short plasma treatment time of 10 s and brief air exposure were sufficient for generating an optimum amount of peroxides and hydroperoxides for the subsequent UV-induced graft polymerization. The graft concentration of the PEGMA polymer increased with increasing PEGMA macromonomer concentration for the graft polymerization and with increasing UV graft polymerization time. The PEGMA graft-polymerized silicon surface with a high poly(ethylene glycol) graft concentration was very effective in preventing protein adsorption and platelet adhesion. The grafted PEGMA polymer layer on the Si(100) surface exhibited fairly good stability during storage in a buffer solution.