715 Implementation of Enhanced Recovery After Surgery (ERAS) in Total Laryngectomies

Aim

The Enhanced Recovery After Surgery (ERAS) protocol for total laryngectomies was first implemented in our tertiary head and neck centre from November 2019. It includes pre-operative carbohydrate loading and an early swallow test which facilitates recommencement of oral intake to improve outcomes. Protocol adherence rate and patient outcomes were measured to determine the effectiveness and benefits of ERAS in laryngectomy patients.

Method

22 total laryngectomy patients from November 2019 to September 2021 were enrolled onto the ERAS protocol, 18 primary and 3 salvage cases. An analysis of the respective patient cohorts was performed to determine adherence to the ERAS protocol and outcomes such as complications and length of inpatient stay were measured.

Results

19 patients (86%) received pre-operative carbohydrate loading successfully, while 3 patients were contraindicated due to background of diabetes. Early swallow test was performed in 59% of patients. Potential reasons for delay were stoma dehiscence or clinical suspicion of neo-pharyngeal leak. 59% of primary cases were deemed medically fit for discharge within the target timeframe of 12–14 days whereas no target was set for salvage cases due to expected poor healing. Main complication in primary cases was neo-pharyngeal leak followed by stoma dehiscence with 28% and 11% respectively.

Conclusion

Limitations of our study include small sample size due to the COVID-19 pandemic. Despite its infancy, the ERAS protocol has achieved good outcomes in early recommencement of oral intake post-laryngectomy and encouraging early safe discharge from hospital. Future plans include establishment of Prehab Clinic and application of ERAS to neck dissection patients.

Risk factors and outcome of community onset Pseudomonas aeruginosa bacteraemia in two Malaysian district specialist hospitals

INTRODUCTION

Despite the ever-growing number of community onset (CO) Pseudomonas aeruginosa (P. aeruginosa) bacteraemia, there is a dearth of district hospital-based research examining this significant infection, which is associated with high mortality. The objectives of this study were as following: (1) to determine the risk factors of CO P. aeruginosa bacteraemia, (2) to compare the 30-day mortality rate between P. aeruginosa and Escherichia coli bacteraemia and (3) to identify the predictors of 30-day mortality for CO gram negative bacteraemia.

METHODS

This is a retrospective case control study in Hospital Seri Manjung and Hospital Teluk Intan, Perak, Malaysia. P. aeruginosa bacteraemia cases that occurred between 1st January 2015 to 31st December 2019 were included, whilst E. coli bacteraemia cases that occurred within the same period were recruited successively until 1:2 case control ratio was achieved. Subjects below 12-year-old and those with polymicrobial bacteraemia were excluded. Demographic, clinical and treatment data were collected using pre-tested data collection forms by trained investigators.

RESULTS

A total of 61 patients with P. aeruginosa bacteraemia and 122 patients with E. coli bacteraemia were included. Recent admission in the earlier three months, regular haemodialysis, immunosuppressive therapy in the past 30 days, chronic wound/pressure sore at presentation and indwelling urinary catheter at presentation were identified as independent predictors of CO pseudomonal bacteraemia. Whilst older age was identified as a negative predictor of CO Pseudomonal bacteraemia (all p<0.05). The 30-day mortality rate was 34.4% in subjects with P. aeruginosa bacteraemia and 27.0% in those with E. coli bacteraemia (p=0.302). Predictors of 30-day mortality for community onset gram negative bacteraemia were as follow: older age, underlying solid tumours, neutropaenia at presentation, in-patient mechanical ventilation, and inpatient nasogastric tube insertion. Unexpectedly, receipt of inappropriate empirical antibiotics which was switched later (delayed and non-delayed switching) was identified as the negative predictors of mortality (all p<0.05).

CONCLUSION

It is prudent to restrict the usage of empirical anti-pseudomonal antibiotics among individuals at risk as liberal usage of broad-spectrum antibiotics engenders emergence of drug resistant organism, particularly in district setting where community onset pseudomonal bacteraemia remains scarce. Subjects with elevated risk of mortality should receive early escalation of care as per sepsis management guidelines.

PesTrapp mobile app: A trap setting application for real-time entomological field and laboratory study

Diseases such as malaria, dengue, Zika and chikungunya remain endemic in many countries. Setting and deploying traps to capture the host/vector species are fundamental to understand their density and distributions. Human effort to manage the trap data accurately and timely is an exhaustive endeavour when the study area expands and period prolongs. One stop mobile app to manage and monitor the process of targeted species trapping, from field to laboratory level is still scarce. Toward this end, we developed a new mobile app named "PesTrapp" to acquire the vector density index based on the mobile updates of ovitraps and species information in field and laboratory. This study aimed to highlight the mobile app's development and design, elucidate the practical user experiences of using the app and evaluate the preliminary user assessment of the mobile app. The mobile app was developed using mobile framework and database. User evaluation of the mobile app was based on the adjusted Mobile App Rating Scale and Standardized User Experience Percentile Rank Questionnaire. The process flows of system design and detailed screen layouts were described. The user experiences with and without the app in a project to study Aedes surveillance in six study sites in Selangor, Malaysia were elucidated. The overall mean user evaluation score of the mobile app was 4.0 out of 5 (SD=0.6), reflects its acceptability of the users. The PesTrapp, a one-stop solution, is anticipated to improve the entomological surveillance work processes. This new mobile app can contribute as a tool in the vector control countermeasure strategies.

Changing pattern of pheochromocytoma and paraganglioma in a stable UK population

Context

Pheochromocytomas and paragangliomas (PCC/PGLs) are diagnosed variously with increasing incidence and changing clinical and pathology pattern.

Objective

The aim was to further characterize PCC/PGLs in a stable population.

Methods

A retrospective, single institution study analysed adrenalectomies for PCC/PGLs between January 2010 - January 2019. Demographics, symptoms, blood pressure, preoperative hormones, imaging, histology, hospital stay, complications and three subgroups [based on the modality of diagnosis - incidentaloma group (IG), genetic group (GG) and symptomatic group (SG)] were noted.

Results

86 patients included IG 51 (59.3%), GG 10 (11.62%) and SG 25 patients (29.06%). Incidence was 5.30 cases/1 million population. 33.34% of the IG had a delayed diagnosis with a mean interval of 22.95 months (4-120 months). Females presented more often with paroxysmal symptoms (PS) (p=0.011). Patients with PS and classic symptoms were younger (p=0.0087, p=0.0004) and those with PS required more inotropes postoperatively (p=0.014). SG had higher preoperative hormone levels (p=0.0048), larger tumors (p=0.0169) and more likely females. GG are younger compared with those from the IG (p=0.0001) or SG (p= 0.178).

Conclusion

Majority of patients had an incidental and delayed diagnosis. If symptomatic, patients are more likely to be young females with higher hormone levels and larger tumors.

Prevalence and characteristics of e-cigarette users among Malaysian current and ex-smokers

INTRODUCTION

Electronic cigarettes (ECs) are new devices that have been accepted widely by both smokers and non-smokers. However, the evidence on EC used in Malaysia is scarce. The objective of this study was to determine the prevalence of EC use and the socio-demographic and smoking characteristics associated with current EC use among Malaysian current and ex-smokers.

METHODS

This was a sub-analysis of data from a cross-sectional, national-population- based EC study conducted from May to June in 2016 in Malaysia. A detailed description of the sampling methods can be found in the National E-cigarette Survey (NECS) 2016 report. Briefly, data were obtained from 1396 individuals who had ever been smokers, i.e., 957 (68.6%) current smokers and 439 (31.4%) ex-smokers.

RESULTS

Current EC use was found predominantly among current smokers (8.0%) as compared with ex-smokers (4.3%). Among current smokers, the main reasons given for smoking ECs were wanting to try it (44.7%), followed by intention to quit tobacco smoking (15.8%) and to reduce tobacco smoking (10.5%). Using multiple logistic regression analysis, we found that among current smokers, current EC users were more likely to be younger, i.e., 18-44 years (aOR= 4.83, 95% CI= 1.97-11.86, p=0.001), urban residents (aOR= 1.89, 95% CI= 1.15-3.11, p=0.012), single/ divorced/ widowed (aOR= 2.11, 95% CI= 1.24-3.61, p=0.006) and students (aOR= 2.25, 95% CI= 1.01-5.01, p=0.048). Among exsmokers, only younger respondents (18-44 years old) was reported as being more likely to be current EC users (aOR= 3.81, 95% CI= 1.14-12.76, p=0.030).

CONCLUSION

This study showed that currently using and ever having used ECs were more prevalent among current smokers. The reasons given for initiating EC use among current smokers were mainly wanting to try it, followed by intention to quit and to reduce tobacco smoking. Current EC use appears to be common among current smokers who are younger, urban residents, single/divorced/widowed and students. Therefore, EC cessation intervention strategies and policies should target these high-prevalence groups.

Hardly water-soluble drug-loaded gelatin nanoparticles sustaining a slow release: preparation by novel single-step O/W/O emulsion accompanying solvent diffusion

Paclitaxel (PTX)-loaded gelatin nanoparticles (NPs) were prepared, for the first time, by novel O/W/O emulsion with a single-step emulsion process accompanying solvent diffusion, in contrast to the conventional double-step emulsion processes. Linoleic acid was chosen among the natural fatty acids as the exterior medium for the single-step emulsion process accompanying solvent diffusion. The size mean and zeta potential of the PTX-loaded gelatin NPs in their suspension were 164.95 nm (±6.43 nm) distributed with a polydispersity of 0.074 (±0.046) and -23.85 mV (±12.66 mV), respectively. The size of the PTX-loaded gelatin NPs prepared in this study was the smallest among the reported sizes of PTX-loaded gelatin NPs, which would contribute to the enhanced permeability and retention (EPR). In addition, TEM showed that the loaded PTX was located mostly inside the gelatin NPs unlike previous investigations. Accordingly, the conceptual model of the designed PTX-loaded gelatin nanoparticle was introduced. Sustaining a slow PTX release on a day-time scale without an initial burst release into a release medium was observed along with a delay of more than 2 days (i.e., 50 h) before a bursting PTX release from 50 to 70 h despite the addition of a protein degrading enzyme. The observed PTX-loading efficiency was 54.5%. This loading efficiency was greater than that of previous study using gelatin of bloom 75-100 of Lu et al. to prepare PTX-loaded gelatin NPs using a desolvation method.

Validity of self-reported weight and height: a cross-sectional study among Malaysian adolescents

Background

Self-reported weight and height are commonly used in lieu of direct measurements of weight and height in large epidemiological surveys due to inevitable constraints such as budget and human resource. However, the validity of self-reported weight and height, particularly among adolescents, needs to be verified as misreporting could lead to misclassification of body mass index and therefore overestimation or underestimation of the burden of BMI-related diseases. The objective of this study was to determine the validity of self-reported weight and height among Malaysian secondary school children.

Methods

Both self-reported and directly measured weight and height of a subgroup of 663 apparently healthy schoolchildren from the Malaysian Adolescent Health Risk Behaviour (MyAHRB) survey 2013/2014 were analysed. Respondents were required to report their current body weight and height via a self-administrative questionnaire before they were measured by investigators. The validity of self-reported against directly measured weight and height was examined using intraclass correlation coefficient (ICC), the Bland-Altman plot and weighted Kappa statistics.

Results

There was very good intraclass correlation between self-reported and directly measured weight [r = 0.96, 95% confidence interval (CI): 0.93, 0.97] and height (r = 0.94, 95% CI: 0.90, 0.96). In addition the Bland-Altman plots indicated that the mean difference between self-reported and direct measurement was relatively small. The mean difference (self-reported minus direct measurements) was, for boys: weight, −2.1 kg; height, −1.6 cm; BMI, −0.44 kg/m² and girls: weight, −1.2 kg; height, −0.9 cm; BMI, −0.3 kg/m². However, 95% limits of agreement were wide which indicated substantial discrepancies between self-reported and direct measurements method at the individual level. Nonetheless, the weighted Kappa statistics demonstrated a substantial agreement between BMI status categorised based on self-reported weight and height and the direct measurements (kappa = 0.76, 95% CI: 0.67, 0.84).

Conclusion

Our results show that the self-reported weight and height were consistent with direct measurements and therefore can be used in assessing the nutritional status of Malaysian school children from the age of 13 to 17 years old in epidemiological studies and for surveillance purposes when direct measurements are not feasible, but not for assessing nutritional status at the individual level.

Steroid Responsive Mononeuritis Multiplex in the Cronkhite-Canada Syndrome

The Cronkhite-Canada syndrome (CCS) is a rare disorder of unknown origin characterized by generalized gastrointestinal polyposis, alopecia, hyperpigmentation, and onychodystrophy. We report a case of CCS with concomitant presentation of mononeuritis multiplex. The electrophysiological findings and steroid responsiveness suggests presence of an autoimmune mechanism.

Expression of CALR mutants causes mpl-dependent thrombocytosis in zebrafish

CALR mutations are identified in about 30% of JAK2/MPL-unmutated myeloproliferative neoplasms (MPNs) including essential thrombocythemia (ET) and primary myelofibrosis. Although the molecular pathogenesis of CALR mutations leading to MPNs has been studied using in vitro cell lines models, how mutant CALR may affect developmental hematopoiesis remains unknown. Here we took advantage of the zebrafish model to examine the effects of mutant CALR on early hematopoiesis and model human CALR-mutated MPNs. We identified three zebrafish genes orthologous to human CALR, referred to as calr, calr3a and calr3b. The expression of CALR-del52 and CALR-ins5 mutants caused an increase in the hematopoietic stem/progenitor cells followed by thrombocytosis without affecting normal angiogenesis. The expression of CALR mutants also perturbed early developmental hematopoiesis in zebrafish. Importantly, morpholino knockdown of mpl but not epor or csf3r could significantly attenuate the effects of mutant CALR. Furthermore, the expression of mutant CALR caused jak-stat signaling activation in zebrafish that could be blocked by JAK inhibitors (ruxolitinib and fedratinib). These findings showed that mutant CALR activates jak-stat signaling through an mpl-dependent mechanism to mediate pathogenic thrombopoiesis in zebrafish, and illustrated that the signaling machinery related to mutant CALR tumorigenesis are conserved between human and zebrafish.

Prevalence of smoking and its associated factors with smoking among elderly smokers in Malaysia: findings from a nationwide population-based study

BACKGROUND

The determination of smoking prevalence and its associated factors among the elderly could provide evidence-based findings to guide the planning and implementation of policy in order to will help in reducing the morbidity and mortality of smoking-related diseases, thus increase their quality of life. This paper describes the rate of smoking and identifies the factor(s) associated with smoking among the elderly in Malaysia.

METHODS

A representative sample of 2674 respondents was obtained via a two-stage sampling method in proportion to population size. Face-to-face interviews were conducted using a set of standardized validated questionnaire. Data was weighted by taking into consideration the complex sampling design and non-response rate prior to data analysis. Univariable and multivariable logistic regression were used to determine the factor/s associated with smoking.

RESULTS

The prevalence of non-smokers, ex-smokers and current smokers among Malaysians aged 60 years and above were 36.3 % (95 % CI = 32.7-39.8), 24.4 % (95 % CI = 21.2-27.5) and 11.9 % (95 % CI = 9.5-14.3), respectively. Current smokers were significantly more prevalent in men (28.1 %) than in women (2.9 %), but the prevalence declined with advancing age, higher educational attainment, and among respondents with known diabetes, hypertension and hypercholesterolemia. Multivariable analysis revealed that males (aOR, 18.6, 95 % CI 10.9-31.9) and other Bumiputras (aOR 2.58, 95 % CI 1.29-5.15) were more likely to smoke. in addition, elderly with lower educational attainment (aOR, 1.70, 95 % CI 1.24-7.41) and those without/unknown hypertension also reported higher likelihood to be current smokers (aOR 1.98, 95 % CI 1.35-2.83). However, there were no significant associations between respondents with no/unknown diabetes or hypercholesterolemia with smoking.

CONCLUSIONS

In short, smoking is common among elderly men in Malaysia. Therefore, intervention programs should integrate the present findings to reduce the smoking rate and increase the smoking cessation rate among the elderly in Malaysia and subsequently to reduce the burden of smoking-related disease.

Eosinophilic gastroenteritis: Clinical profiles and treatment outcomes, a retrospective study of 18 adult patients in a Singapore Tertiary Hospital

BACKGROUND

Eosinophilic gastroenteritis (EG) can mimic symptoms of common gastrointestinal (GI) disorders but responds well to appropriate treatment. Accurate diagnosis is central to effective management. Data on EG in Southeast Asia is lacking. We aim to describe the clinical profiles and treatment outcomes of adult patients with EG in a Singapore Tertiary Hospital.

MATERIALS AND METHODS

This retrospective study involved archival search of patients with GI biopsies that showed eosinophilic infiltration from January 2004 to December 2012. Patients' clinical data from computerised hospital records and clinical notes was reviewed. Diagnostic criteria for EG included presence of GI symptoms with more than 30 eosinophils/high power field on GI biopsies. Patients with secondary causes for eosinophilia were excluded.

RESULTS

Eighteen patients with EG were identified (mean age 52 years; male/female: 11/7). Fifteen patients (83%) had peripheral blood eosinophilia. Seven patients (39%) had atopic conditions. Most common symptoms were diarrhoea and abdominal pain. Small intestine was the most common site involved. Endoscopic finding was non-specific. Ten patients were treated with corticosteroids (nine prednisolone, one budesonide): eight patients (89%) responded clinically to prednisolone but four patients (50%) relapsed following tapering-off of prednisolone and required maintenance dose. One patient each responded to diet elimination and montelukast respectively. Half of the remaining six patients who were treated with proton-pump inhibitors, antispasmodic or antidiarrheal agents still remained symptomatic.

CONCLUSION

Prednisolone is an effective treatment though relapses are common. Small intestine is most commonly involved. EG should be considered in the evaluation of unexplained chronic recurrent GI symptoms.

Annexin-1 regulated by HAUSP is essential for UV-induced damage response

DNA damage can occur through diverse stimulations such as toxins, drugs, and environmental factors. To respond to DNA damage, mammalian cells induce DNA damage response (DDR). DDR signal activates a rapid signal transduction pathway, regulating the cell fate based on the damaged cell condition. Moreover, serious damaged cells have to be eliminated by the macrophage to maintain homeostasis. Because the DDR induces genomic instability followed by tumor formation, targeting the DDR signaling can be applied for the cancer therapy. Herpes virus-associated ubiquitin-specific protease (HAUSP/USP7) is one of the well-known deubiquitinating enzymes (DUBs) owing to its relevance with Mdm2-p53 complex. The involvement of HAUSP in DDR through p53 led us to investigate novel substrates for HAUSP, which is related to DDR or apoptosis. As a result, we identified annexin-1 (ANXA1) as one of the putative substrates for HAUSP. ANXA1 has numerous roles in cellular systems including anti-inflammation, damage response, and apoptosis. Several studies have demonstrated that ANXA1 can be modified in a post-translational manner by processes such as phosphorylation, SUMOylation, and ubiquitination. In addition, DNA damage gives various functions to ANXA1 such as stress response or cleavage-mediated apoptotic cell clearance. In the current study, our proteomic analysis using two-dimensional electrophoresis, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS) and nano LC-MS/MS, and immunoprecipitation revealed that ANXA1 binds to HAUSP through its HAUSP-binding motif (P/AXXS), and the cleavage and damage-responsive functions of ANXA1 upon UV-induced DNA damage may be followed by HAUSP-mediated deubiquitination of ANXA1. Intriguingly, the UV-induced damage responses via HAUSP-ANXA1 interaction in HeLa cells were different from the responses shown in the Jurkat cells, suggesting that their change of roles may depend on the cell types.

Prevalence, awareness, treatment and control of diabetes mellitus among the elderly: The 2011 National Health and Morbidity Survey, Malaysia

Diabetes mellitus is an important cardiovascular risk factor. The objective of this study was to provide population-based estimates on the prevalence, awareness, treatment and control rate of diabetes among the older persons in Malaysia. Analysis of secondary data from a cross-sectional national population-based survey was done, which was conducted in 2011 throughout Malaysia. A total of 2764 respondents (15.5%) were older persons. The overall prevalence of diabetes among older persons was 34.4% in which 65.2% were aware of their diabetes status. Out of those who were aware, 87.5% had been treated. Only 21.8% of those treated had their diabetes controlled. The results of multiple logistic regression showed that the factors associated with higher awareness rates were women, Indians and higher income groups; factors associated with higher treatment rates were urban residents and those who were married and widow/widower/ divorcee. There was a high overall prevalence, awareness and treatment rate of diabetes among older persons in Malaysia but with suboptimal control rate.

Duplication of the vermiform appendix in an adult patient

Duplication of the appendix is extremely rare. A 69-year-old woman was admitted with a 2-day history of right lower quadrant abdominal pain. Physical examination was consistent with acute appendicitis. Ultrasonography and colonoscopy gave a clinical impression of an inflammatory appendiceal mucocoele. Operative findings were an enlarged and inflamed appendix with distal cystic changes. Laparoscopic wedge resection of the caecum was performed. A tubular structure with a true lumen was found in the appendix. Haematoxylin and eosin staining and trichrome staining showed both structures had a true mucosa and a muscular layer. The duplication in this case does not belong to any of the previously described types of duplication.

The prevalence of physical activity and its associated factors among Malaysian adults: findings from the National Health and Morbidity Survey 2011

OBJECTIVES

Despite the health-enhancing benefits of physical activity, a large segment of the Malaysian population does not engage in regular physical activity at the recommended level. This study aimed to determine physical activity patterns and the associated sociodemographic correlates of physical activity.

STUDY DESIGN

Data on physical activity were obtained from the National Health and Morbidity Survey (NHMS) 2011, a nationally representative, population-based cross-sectional study. A two-stage stratified sampling method was used to select a representative sample of Malaysian adults aged 16 years and above.

METHODS

A total of 19,145 adults aged 16 years and above were recruited, and face-to-face interviews were conducted using the International Physical Activity Questionnaire (IPAQ), short version. The correlates for physical activity were identified using multivariate analysis.

RESULTS

In this study, 64.3% (95%CI: 63.1-65.5) of Malaysian adults aged 16 and above were physically active, but overall physical activity levels decreased with advancing age. Men, rural residents, 'other' ethnic groups, and married women were more likely to demonstrate higher levels of physical activity.

CONCLUSION

Approximately 65% of Malaysian adults were physically active. However, it is recommended that health promotions for active lifestyles should be targeted to the least active segments, which constitute more than a quarter of the Malaysian population.

Higher serum uric acid is associated with higher bone mass, lower bone turnover, and lower prevalence of vertebral fracture in healthy postmenopausal women

Higher serum uric acid (UA) was associated with higher bone mass, lower bone turnover, and lower prevalence of vertebral fracture in postmenopausal women. Furthermore, UA suppressed osteoclastogenesis and decreased production of reactive oxygen species in osteoclast precursors, indicating UA may have beneficial effects on bone metabolism as an antioxidant.

INTRODUCTION

UA is known to play a physiological role as an antioxidant, and oxidative stress has detrimental effects on bone metabolism. In the present study, we investigated the association of serum UA level with the osteoporosis-related phenotypes and its direct effect on bone-resorbing osteoclasts using in vitro systems.

METHODS

This is a large cross-sectional study, including 7,502 healthy postmenopausal women. Bone mineral density (BMD) and serum UA concentrations were obtained from all subjects. Data on bone turnover markers and lateral thoracolumbar radiographs were available for 1,023 and 6,918 subjects, respectively. An in vitro study investigated osteoclastogenesis and reactive oxygen species (ROS) levels according to UA treatment.

RESULTS

After adjusting for multiple confounders, serum UA levels were positively associated with BMD at all sites (all p < 0.001). Compared with the participants in the highest UA quartile, the odds for osteoporosis were 40 % higher in those in the lowest quartile. The serum UA levels were inversely related to both serum C-terminal telopeptide of type I collagen and osteocalcin levels (p < 0.001 and p = 0.004, respectively). Consistently, subjects with vertebral fracture had lower serum UA levels, compared with those without it (p = 0.009). An in vitro study showed that UA decreased osteoclastogenesis in a dose-dependent manner and reduced the production of ROS in osteoclast precursors.

CONCLUSION

These results provide epidemiological and experimental evidence that serum UA may have a beneficial effect on bone metabolism as an antioxidant in postmenopausal women.

Heaviness of smoking index, number of cigarettes smoked and the Fagerstrom test for nicotine dependence among adult male Malaysians

Two methods of identifying smokers with high nicotine dependence, the heaviness of smoking index (HSI) and number of cigarettes per day (CPD) were compared with the Fagerstrom test for nicotine dependence (FTND). The HSI, CPD and the FTND were administered to 316 adult Malaysian male, daily smokers aged between 25-64 years old in the Malaysian NCD Surveillance-1 Survey using a two-stage stratified random sampling of enumeration blocks and living quarters, via an interview based on a validated questionnaire. The cut-off point for classification of high nicotine dependence on the HSI was a score of four or higher, and for the heavy smoking category, smoking more than 20 cigarettes per day. Classification using each method was compared with classification by the FTND (score of six or more) as the reference standard. Sensitivity, specificity and kappa statistics for concordance between both measures and the FTND were evaluated. The HSI gave a similar prevalence rate of high nicotine dependence as the FTND. There was substantial agreement between the HSI and the FTND (kappa=0.63.), with moderate sensitivity (69.8%) and high specificity (92.5%). However, prevalence of high nicotine dependence using the CPD was 7% lower than the FTND. The heavy smoking category also showed fair agreement with the FTND (kappa=0.45) and moderate sensitivity (67.0%), but specificity was high (86.9%). The findings indicate that the HSI can be used as an alternative to the FTND in screening for high nicotine dependence among daily smokers in large population-based studies, while CPD may not be a suitable alternative to the FTND.

Inflammatory myofibroblastic tumour of the duodenum

Inflammatory myofibroblastic tumours (IMTs) of the duodenum and head of the pancreas are rare. They are of probable immunological aetiology and preoperatively indistinguishable from adenocarcinomas of the pancreatic head. We describe a patient with duodenal IMT and gastric outlet obstruction, and present a review of pancreatic head and duodenal IMTs in the literature. IMTs of the pancreatic head present as obstructive jaundice, while those of the duodenum present as gastric outlet obstruction. Surgery is the primary modality of treatment. Adjuvant chemotherapy and radiotherapy are controversial and reserved for incomplete resections and IMTs of a pathologically aggressive nature. Otherwise, recurrence is uncommon and surgery curative.

Sensitivity and specificity of waist circumference as a single screening tool for identification of overweight and obesity among Malaysian adults

Generalised obesity and central obesity are risk factors for Type II diabetes mellitus and cardiovascular diseases. Waist circumference (WC) has been suggested as a single screening tool for identification of overweight or obese subjects in lieu of the body mass index (BMI) for weight management in public health program. Currently, the recommended waist circumference cut-off points of > or = 94cm for men and > or =80cm for women (waist action level 1) and > or = 102cm for men and > or = 88cm for women (waist action level 2) used for identification of overweight and obesity are based on studies in Caucasian populations. The objective of this study was to assess the sensitivity and specificity of the recommended waist action levels, and to determine optimal WC cut-off points for identification of overweight or obesity with central fat distribution based on BMI for Malaysian adults. Data from 32,773 subjects (14,982 men and 17,791 women) aged 18 and above who participated in the Third National Health Morbidity Survey in 2006 were analysed. Sensitivity and specificity of WC at waist action level 1 were 48.3% and 97.5% for men; and 84.2% and 80.6% for women when compared to the cut-off points based on BMI > or = 25kg/m2. At waist action level 2, sensitivity and specificity were 52.4% and 98.0% for men, and 79.2% and 85.4% for women when compared with the cut-off points based on BMI (> or = 30 kg/m2). Receiver operating characteristic analyses showed that the appropriatescreening cut-off points for WC to identify subjects with overweight (> or = 25kg/m2) was 86.0cm (sensitivity=83.6%, specificity=82.5%) for men, and 79.1cm (sensitivity=85.0%, specificity=79.5%) for women. Waist circumference cut-off points to identify obese subjects (BMI > or = 30 kg/m2) was 93.2cm (sensitivity=86.5%, specificity=85.7%) for men and 85.2cm (sensitivity=77.9%, specificity=78.0%) for women. Our findings demonstrated that the current recommended waist circumference cut-off points have low sensitivity for identification of overweight and obesity in men. We suggest that these newly identified cut-off points be considered.

Acalypha wilkesiana extracts induce apoptosis by causing single strand and double strand DNA breaks

ETHNOPHARMACOLOGICAL RELEVANCE

The seeds of Acalypha wilkesiana have been used empirically by traditional healers in Southwest Nigeria together with other plants as a powder mixture to treat patients with breast tumours and inflammation.

AIM OF THE STUDY

There is an increasing interest among researchers in searching for new anticancer drugs from natural resources, particularly plants. This study aimed to investigate the anticancer properties of Acalypha wilkesiana extracts and the characteristics of DNA damage against brain and lung cancer cells.

MATERIALS AND METHODS

The antiproliferative activity of Acalypha wilkesiana extracts (ethyl acetate, hexane, and ethanol) was examined on human glioma (U87MG), human lung carcinoma (A549), and human lung fibroblast (MRC5) cells.

RESULTS

Cell viability MTT assay revealed that ethyl acetate extract of the plant possessed significant antiproliferative effects against both U87MG (GI(50)=28.03 ± 6.44 μg/ml) and A549 (GI(50)=89.63 ± 2.12 μg/ml) cells (p value<0.0001). The hexane extract was found to exhibit crucial antiproliferative effects on U87MG (GI(50)=166.30 ± 30.50 μg/ml) (p value<0.0001) but not on A549 cells. Neither plant extract possessed noticeable antiproliferative effects on the non-cancerous MRC5 cells (GI(50)>300 μg/ml). The ethanol extract showed no antiproliferative effects on any cell line examined. Haematoxylin & Eosin (H & E) staining and single cell gel electrophoresis (SCGE) comet assay confirmed that plant extract-treated cells underwent apoptosis and not necrosis. SCGE comet assays confirmed that plant extracts caused both single strand (SSB) and double strand (DSB) DNA breaks that led to the execution of apoptosis.

CONCLUSION

The extracts (especially ethyl acetate and hexane) of Acalypha wilkesiana possess valuable cytotoxic effects that trigger apoptosis in U87MG and A549 cancer cells through induction of DNA SSBs and DSBs.

Solitary caecal ulcer syndrome: our experience with this benign condition

AIM

Solitary caecal ulcer syndrome is rare. We describe our experience of 10 patients with the condition.

METHOD

A prospectively collected database of patients undergoing colonoscopy or surgery with histology reporting a solitary caecal ulcer was reviewed from 1999 to 2008. Patients with known carcinoma of the colon, cytomegalovirus infection, amoebiasis, inflammatory bowel disease, immunosuppression and history of nonsteroidal anti-inflammatory drug use were excluded.

RESULTS

Ten patients were found to have a solitary caecal ulcer. All were of Chinese ethnicity, of median age 61 years. The most common presenting symptoms were haematochezia and right-sided abdominal pain. Histological findings included ulceration sharing some features of solitary rectal ulcer syndrome, but with differences to suggest a different aetiology.

CONCLUSION

Solitary caecal ulcer syndrome should be included in the differential diagnosis of lower gastrointestinal haemorrhage, right iliac fossa pain or when computed tomography imaging demonstrates caecal wall thickening. The diagnosis can only be made on histopathological examination.

Doxycycline induced acute erosive oesophagitis and presenting as acute dysphagia

INTRODUCTION

Drug induced oesophageal disease is common. Doxycycline is one of the commonest cause of drug induced oesophageal ulcers. The medical community often under recognizes the importance of drug induced oesophageal lesions and fails to deliver proper advice and instructions related to drug ingestion. The diagnosis is usually clinical although endoscopy is the gold standard diagnostic tool. Treatment is symptomatic with discontinuation of the drug often being sufficient. Long-term sequelae are infrequent and acute complications uncommon.

CLINICAL PICTURE

A 22-year-old college student was prescribed doxycycline capsules for acne and developed dysphagia. Upper gastrointestinal endoscopy revealed acute erosive oesophagitis.

TREATMENT AND OUTCOME

She was managed symptomatically with proton pump inhibitors and her dysphagia improved over a period of three days. She was discharged with proper advice regarding medication ingestion and proton pump inhibitor for four weeks.

CONCLUSION

Drug induced oesophageal disease is a preventable self-limiting condition. Proper advice regarding medication ingestion is essential for prevention.

Prevalence and factors associated with smoking among form four students in Petaling District, Selangor, Malaysia

A cross-sectional study was conducted among form four students of secondary schools in the District of Petaling, Selangor, Malaysia from February 2008 to June 2008 with the aim of quantifying the prevalence of smoking and identifying the psychosocial factors related to smoking among adolescents in this district. A two-stage stratified sampling strategy was used to obtain a sample of 1300 students based on an estimated prevalence of 10%. The response rate was 80.5% (1045 out of 1298 students). Results showed that prevalence of smoking was higher among male students (22.3%) compared to females (5.5%) and the median age at smoking initiation was lower among males compared to female smokers (14 years old vs 15 years old). Modifiable risk factors associated with smoking were "percentage of friends who smoke" (OR 2.94, 95% CI [1.71- 5.06]) and "having a brother who smokes" (OR 1.97, 95% CI [1.20-3.31]). There was also a correlation between smoking prevalence and the number of risk factors present. Intensification of health education and anti-smoking programmes and modification of external factors in early adolescence are recommended to prevent smoking initiation.

Ectoparasite fauna of rodents and shrews from four habitats in Kuala Lumpur and the states of Selangor and Negeri Sembilan, Malaysia and its public health significance

A total of 204 rodents comprising 14 host species from four different habitats were examined. Nine rodent species were trapped from the forest and another five species were trapped from the coastal, rice field and urban habitats. Rattus rattus diardii (67%) was the predominant rodent species examined. Fifty six (47.3%) rodents and shrews were found to be infested with at least one of the 20 species of ectoparasite recovered. Mites belonging to the family Trombiculidae were the predominant ectoparasite species recovered. Ticks belonging to the family Ixodidae were recovered mainly from the forest dwelling rodents. Polyplax spinulosa and Hoplopleura pacifica were the common lice species found infesting the urban rodents. Xenopsylla cheopis was the only flea species recovered. The following ecto-parasites have been incriminated as important vectors or as mechanical carriers for the transmission of zoonotic diseases: Ixodes granulatus, Dermacentor sp. Haemaphysalis sp., Amblyomma sp. Ascoschoengastia indica, Leptotrombidium deliense, Ornithonyssus bacoti, Laelaps nuttalli, H. pacifica, P. spinulosa and Xenopsylla cheopis. Urban and forest rodents were significantly higher in ecto-parasitic infestation, compared to rats from the other two habitats. However, there was no significant statistical association between male and female rodents infested with ectoparasites.

IVS10+12A>G polymorphism in hMSH2 gene associated with prognosis for patients with colorectal cancer

BACKGROUND

The polymorphisms in DNA repair genes may contribute to a variation in the DNA repair capacity, thereby affecting the risk of carcinogenesis and prognosis of colorectal cancer. Accordingly, the present study analyzed 14 polymorphisms in DNA repair genes and their impact on the prognosis for patients with colorectal cancer.

MATERIALS AND METHODS

Three hundred and ninety-seven consecutive patients with curatively resected colorectal adenocarcinoma were enrolled in the present study. The genomic DNA was extracted from fresh colorectal tissue and 14 polymorphisms of DNA repair genes determined using a real-time PCR genotyping assay.

RESULTS

The median age of the patients was 63 years, and 218 (54.9%) patients had colon cancer, while 179 (45.1%) patients had rectal cancer. A multivariate survival analysis, including age, differentiation, carcinoembryonic antigen level, and stage, revealed a better survival for the patients with the combined IVS10+12AG and GG genotype than for the patients with the IVS10+12AA genotype [disease-free survival: hazard ratio (HR) 0.47, 95% confidence interval (CI) 0.30-0.75, P = 0.002; overall survival: HR 0.50, 95% CI 0.26-0.98, P = 0.042]. None of the other polymorphisms was associated with survival.

CONCLUSION

The IVS10+12A>G polymorphism in the hMSH2 gene was found to be an independent prognostic marker for patients with colorectal cancer.

Tobacco use, knowledge and attitude among Malaysians age 18 and above

This study aims to determine the level of knowledge and to understand their attitude towards smoking and secondly to determine how sociodemographic background, smoking status and knowledge on the health risks of smoking contribute toward the development of such attitude. A total of 10,545 respondents age 18 years and above across Malaysia were interviewed. Results indicated that level of knowledge and attitude varied by gender, education level, smoking status, age, ethnicity and smoker category. Smokers' low education, poor knowledge on the dangers of smoking and being males had more positive or greater impact on their attitudes towards smoking. Formulation and implementation of a holistic programme aimed at increasing knowledge and attitude change that accounts for sociodemographic background of the population is recommended in order to bring down smoking rates and thus reduce smoking related health problems in this country.

Endo-parasite fauna of rodents caught in five wet markets in Kuala Lumpur and its potential zoonotic implications

Rodents were collected from five wet markets (Chow Kit, Dato Keramat, Setapak, Jinjang and Kepong) in Kuala Lumpur, Federal Territory between March to April 2006. Ninety seven rats were trapped using wire traps measuring 29 x 22 x 50 cm baited with fruits, coconuts, dried fish or sweet potatoes. A total of 17 different species of parasites were identified from three species of rats out of which 11 (65%) were identified to be zoonotic. The helminths identified from the urban rats were nematodes- Capillaria hepatica, Gongylonema neoplasticum, Heterakis spumosa, Heterakis sp., Masterphorus muris, Nippostrongylus brasiliensis, Physolaptera sp., Pterogodermatis sp., Rictularia tani and Syphacia muris; cestodes- Hymenolepis nana, Hymenolepis diminuta, Hymenolepis sabnema, Hymenolepis sp., Raillietina sp. and Taenia taeniaeformis, and acanthocephalan- Moniliformis moniliformis. The following parasites are of potential medical importance: C. hepatica, G. neoplasticum, R. tani, S. muris, H. diminuta, H. nana, Raillietina sp. and T. taeniaeformis.

TET2 mutations and their clinical correlates in polycythemia vera, essential thrombocythemia and myelofibrosis

High-throughput DNA sequence analysis was used to screen for TET2 mutations in bone marrow-derived DNA from 239 patients with BCR-ABL-negative myeloproliferative neoplasms (MPNs). Thirty-two mutations (19 frameshift, 10 nonsense, 3 missense; mostly involving exons 4 and 12) were identified for an overall mutational frequency of approximately 13%. Specific diagnoses included polycythemia vera (PV; n=89), essential thrombocythemia (ET; n=57), primary myelofibrosis (PMF; n=60), post-PV MF (n=14), post-ET MF (n=7) and blast phase PV/ET/MF (n=12); the corresponding mutational frequencies were approximately 16, 5, 17, 14, 14 and 17% (P=0.50). Mutant TET2 was detected in approximately 17 and approximately 7% of JAK2V617F-positive and -negative cases, respectively (P=0.04). However, this apparent clustering of the two mutations was accounted for by an independent association between mutant TET2 and advanced age; mutational frequency was approximately 23% in patients > or =60 years old versus approximately 4% in younger patients (P<0.0001). The presence of mutant TET2 did not affect survival, leukemic transformation or thrombosis in either PV or PMF; a correlation with hemoglobin <10 g per 100 ml in PMF was noted (P=0.05). We conclude that TET2 mutations occur in both JAK2V617F-positive and -negative MPN, are more prevalent in older patients, display similar frequencies across MPN subcategories and disease stages, and hold limited prognostic relevance.

Prospective evaluation of transient elastography for the diagnosis of hepatic fibrosis in Asians: comparison with liver biopsy and aspartate transaminase platelet ratio index

BACKGROUND

Transient elastography (TE) is a reliable non-invasive predictor of hepatic fibrosis, but data on TE in Asians are limited.

AIM

To evaluate prospectively the accuracy of TE for diagnosis of hepatic fibrosis in Asians compared with APRI (aspartate transaminase to platelet ratio index).

METHODS

One hundred and twenty consecutive patients who underwent liver biopsy were enrolled. TE (Fibroscan) was performed by two independent operators. Fibrosis was graded by two independent pathologists using the METAVIR classification. Area under receiver operating curves (AUROC) were used to evaluate the accuracy of TE and APRI in diagnosing significant fibrosis (F >or= 2) and cirrhosis (F4).

RESULTS

Predominant aetiologies were hepatitis B (48%), non-alcoholic steatohepatitis (14%) and hepatitis C (8%). TE was unsuccessful in five patients (4.2%) because of small inter-costal space (three patients), obesity and ascites. There was good correlation between TE and fibrosis (r = 0.606). AUROC for diagnosis of significant fibrosis was 0.856 (95% CI 0.779-0.932) for TE and 0.673 (95% CI 0.568-0.777) for APRI. AUROC for diagnosis of cirrhosis was 0.924 (95% CI 0.857-0.990) for TE and 0.626 (95% CI 0.437-0.815) for APRI. Optimal TE value was 9.0 kPa for diagnosis of significant fibrosis and 16.0 kPa for cirrhosis with specificity/sensitivity/PPV/NPV/accuracy of 82.6%/85.2%/80.9%/86.7%/84.1% and 88.9%/82.7%/32.0%/98.8%/83.2%, respectively.

CONCLUSIONS

Transient elastography is a reliable predictor of hepatic fibrosis in Asians. Failure of TE in Asians is commonly because of small inter-costal space. TE is superior to APRI for non-invasive diagnosis of hepatic fibrosis and cirrhosis.

Prevalence and factors related to smoking among secondary school students in Kota Tinggi District, Johor, Malaysia

Smoking among adolescent is a public health concern in Malaysia. Multiple studies on smoking prevalence and its related factors have been conducted in Malaysia, however, they were specific to either urban or rural areas alone. Studies in mixed settlement areas (urban, rural, land development area) had not been intensively investigated. This study reports the prevalence, demographic and factors related to smoking amongst form four students in the district of Kota Tinggi, Johor. A cross-sectional study of 16-year old secondary school students in Kota Tinggi district was conducted using two-stage stratified, proportionate sampling in July 2005. The study instrument used was a validated structured questionnaire on smoking and its related factors. Smoking prevalence was found to be 29.7%. More than 50% of male students were smokers. Prevalence was highest in FELDA (Federal Land Development Authority) settlement areas. Smoking was associated with having a brother or friend who smokes and poor academic performance. The study revealed that smoking prevalence was high, especially among male students in land development schemes. This situation will contribute to high smoking-related health problems in the future if proper preventive measures are not taken accordingly.

Depressive symptoms of type 2 diabetics treated with insulin compared to diabetics taking oral anti-diabetic drugs: a Korean study

OBJECTIVE

The purpose of this study was to examine the depressive symptoms of type 2 diabetic patients who were treated with insulin compared to those diabetics treated with oral anti-diabetic drugs in Korea.

METHODS

A total 204 outpatients with type 2 diabetes were invited to complete a questionnaire using the Beck depression inventory (BDI) to measure depressive symptoms. Age, gender, body mass index, serum lipid profile, and a social history including marital status, occupation and educational background were also assessed. The presence of diabetic complications was evaluated by examining the patients' medical records. Diabetic patients who were not treated with anti-diabetic drugs were excluded. All the study subjects were classified into two groups based on their mode of therapy: the oral drug group and insulin group. The insulin group included patients treated with insulin-oral drug combinations as well as those treated solely with insulin.

RESULTS

Overall, 32.4% of our diabetic subjects showed depressive symptoms with the criterion being a BDI score > or = 16. Compared to the oral drug group, the insulin group showed a significantly higher frequency of depressive symptoms (insulin group, 48.0%; oral drug group, 27.3%; p<0.01) and higher BDI scores (insulin group, 16.6+/-10.7; oral drug group, 12.6+/-8.7; p<0.01). Moreover, after an adjustment for social factors, the degree of hyperglycemia and the presence of diabetic complications, the insulin group showed a significantly higher frequency of depression (odds ratio 4.38, 95% CI 1.66-11.6, p=0.003), compared to the oral drug group.

CONCLUSIONS

The data showed that insulin treatment is related to the presence of depressive symptoms, and the importance of more careful psychological support of Korean insulin-treated type 2 diabetic patients is strongly suggested.

The medical alumni story

The Medical Alumni is unique in being the oldest alumni association with medical, dental and pharmacy graduates from our seminal medical school, that has now evolved into the faculties of medicine in 2 countries, namely Malaysia and Singapore. Founded in 1923, the medical alumni association has undergone several name changes with its evolution and activism. After the Japanese Occupation, it was given its present name in 1947, comprising 3 branches working under a common Constitution operating in 2 separate countries. It is also unique in being the only association recognised by the Registrar of Societies with membership in 2 countries. Following the development of medical professional and academic bodies, the medical alumni wound down its medico-political activities to concentrate on providing social and mutual support for its members and its alma mater.

The medical students' societies and medical students' publications

The rich corporate life of the medical student and the medical students' societies at our medical school (at the present National University of Singapore) is generally unappreciated by its graduates and regrettably, even more unknown to the medical student of today. The present generation of medical students of NUS do not know of their rich history. We have published documentation of student activities from the founding of the medical school in 1905 till the establishment of the then University of Malaya in 1950, reviewed herein. Materials presented after 1950 were gathered from personal communications from key players in the students' societies and from editors of the medical students' publications.

Use of oesophagogastroscopy to assess the response of oesophageal carcinoma to neoadjuvant therapy

BACKGROUND

Approximately 25 per cent of patients with oesophageal cancer who undergo neoadjuvant chemoradiotherapy have no evidence of tumour in the resected specimen (complete pathological response). Those who do not respond have a poor 5-year survival compared with complete responders, regardless of whether or not they undergo surgery. Selecting for surgery only those who have a response to neoadjuvant therapy has the potential to improve overall survival as well as to rationalize the management of non-responders. This study assessed the accuracy of oesophagogastroscopy in this setting.

METHODS

A prospective database of 804 patients undergoing oesophageal resection for carcinoma was reviewed. Endoscopic assessment of the response to neoadjuvant therapy in 100 consecutive patients was compared with the pathological assessment of response. The survival for each level of response was compared.

RESULTS

At endoscopy 30 patients were considered to have had a complete response. This was confirmed pathologically in 15 patients. Survival was improved in those with a pathologically confirmed complete response (3-year survival rate 62.4 (s.e. 12.9) per cent) compared with non-responders (16.3 (s.e. 6.6) per cent). Those with microscopic residual disease also had an improved 3-year survival rate (46.3 (s.e. 12.2) per cent); however, oesophagogastroscopy failed to identify this subset.

CONCLUSION

Oesophagogastroscopy may be useful in the assessment of tumour response to neoadjuvant therapy. However, owing to its poor accuracy patients should not be excluded from further therapeutic intervention on the basis of this assessment alone.

Acute myocardial infarction in the elderly--the differences compared with the young

OBJECTIVES

The aim of the study was to determine the differences in presentation, complications, management and outcome of elderly patients with acute myocardial infarction (AMI) compared to young patients.

MATERIALS AND METHODS

All case-notes with a discharge or death diagnosis ofAMI between January and July 1999 at a restructured hospital in Singapore were reviewed retropectively. Patients were categorised into those younger than 65 years (young) and those 65 years or older (elderly). Data on the demographic and clinical profile of patients were collected.

RESULTS

There were 112 young and 101 elderly AMI patients. Chest pain was the most common presentation in both age groups, but more likely in the young than the elderly (89.3% vs 66.3%; p < 0.001). Atypical presentations were more likely in the elderly, with shortness of breath as the most common presentation (20.8% vs 5.4%; p < 0.001). The elderly were more likely to have complications of cardiac failure (65.3% vs 25%; p < 0.001) and cardiogenic shock (8.9% vs 0.9%; p = 0.006). The elderly were less likely to receive thrombolytic therapy (35.8% vs 64.8%; p < 0.001) as they were more likely to have contraindications (34.5% vs 6.8%; p = 0.002). The elderly were also less likely to receive beta-blockers (21.8% vs 60.7%; p < 0.001). In-hospital mortality was higher in the elderly (20.8% vs 2.7%; p < 0.001). Cardiogenic shock complicating AMI was associated with high in-hospital mortality.

CONCLUSION

In AMI patients, chest pain was the most common presentation in both age groups, though less frequently in the elderly. Atypical presentations were more likely in the elderly, with shortness of breath as the most common atypical presentation. In elderly AMI patients, prevalence of cardiac failure was higher, use of beta-blockers was lower and in-hospital mortality was higher than young patients.

A four-dimensional study of the aortic root dynamics

OBJECTIVE

Although aortic root expansion has been well studied, its deformation and physiologic relevance remain controversial. Three-dimensional (3-D) sonomicrometry (200Hz) has made time-related 4-D study possible.

METHODS

Fifteen sonomicrometric crystals were implanted into the aortic root of eight sheep at each base (three), commissures (three), sinuses of Valsalva (three), sinotubular junction (three), and ascending aorta (three). In this acute, open-chest model, the aortic root geometric deformations were time related to left ventricular and aortic pressures.

RESULTS

During the cardiac cycle, aortic root volume increased by mean+/-1 standard error of the mean (SEM) 33.7+/-2.7%, with 36.7+/-3.3% occurring prior to ejection. Expansion started during isovolumic contraction at the base and commissures followed (after a delay) by the sinotubular junction. At the same time, ascending aorta area decreased (-2.6+/-0.4%). During the first third of ejection, the aortic root reached maximal expansion followed by a slow, then late rapid decrease in volume until mid-diastole. During end-diastole, the aortic root volume re-expanded by 11.3+/-2.4%, but with different dynamics at each area level. Although the base and commissural areas re-expanded, the sinotubular junction and ascending aorta areas kept decreasing. At end-diastole, the aortic root had a truncated cone shape (base area>commissures area by 51.6+/-2.0%). During systole, the root became more cylindrical (base area>commissures area by 39.2+/-2.5%) because most of the significant changes occurred at commissural level (63.7+/-3.6%).

CONCLUSION

Aortic root expansion follows a precise chronology during systole and becomes more cylindrical - probably to maximize ejection. These findings might stimulate a more physiologic approach to aortic valve and aortic root surgical procedures.

Analysis of alkali-soluble glucan produced by Saccharomyces cerevisiae wild-type and mutants

The alkali-soluble glucan of the yeast cell wall contains beta-(1,3)- and (1,6)-D-linkages and systemically enhances the immune system. To isolate Saccharomyces cerevisiae mutants producing glucan with a high degree of beta-(1,6)-D-glycosidic bonds, a wild-type strain was mutagenized with ultraviolet light. The mutants were then selected by treatment with 1.0 mg laminarinase, endo-beta-(1,3)-D-glucanase/ml. The alkali-soluble glucan was extracted by modified alkalysis followed by the Cetavlon method and concanavalin-A chromatography. The prepared alkali-soluble glucans from the wild-type and the mutants were compared with respect to yield and polymer structure using gas chromatography, 13C-NMR spectrometry, high performance liquid, and multi-angle laser light scattering and refractive index detectors. The results indicated that the S. cerevisiae mutants had ten-fold more alkali-soluble glucan than the wild-type. Structural analysis revealed that the alkali-soluble glucan from the mutants also had a higher degree of beta-(1,6)-D-linkage than that from the wild-type.

Aortic and pulmonary root: are their dynamics similar?

OBJECTIVES

The long-term behavior of the pulmonary autograft in the aortic position (Ross procedure) remains uncertain. Using three-dimensional (3D) sonomicrometry (200 Hz) we compared the dynamics of the aortic and pulmonary roots.

METHODS

Twenty-four crystals were implanted in each aortic (eight sheep) and pulmonary roots (six sheep) at: base (3 x 2), commissures (3 x 2), sinotubular junction (3 x 2), ascending aorta (3) and pulmonary trunk (3). Under stable hemodynamic conditions, geometric changes were time-related to left ventricular pressure (LV) and aortic pressure.

RESULTS

The expansion of the aortic root is twice that of the pulmonary root. During the cardiac cycle, the aortic root volume increased by 37.7 +/- 2.7% (mean +/- SEM) versus 20.9 +/- 1.0% for the pulmonary root. Both were cone-shaped at end diastole. Because expansion at commissures was twice that of the base, both roots became more cylindrical during ejection. Although both roots started to expand prior to ejection and reached maximal expansion during the first third of ejection, the commissural and sinotubular junction dynamics were different in each root. While in the aortic root, expansion at commissural and sinotubular junction levels was significantly different (63.7 +/- 3.6% versus 37.0 +/- 2.1%), in the pulmonary root, they were similar (29.0 +/- 1.3% versus 27.7 +/- 1.4%). Expansion of the three sinuses was also different (P<0.001). In the aortic root: the right expanded more than the left and more than the non-coronary sinus. In the pulmonary root: the right sinus expanded more than the anterior more than the left.

CONCLUSIONS

Dynamic differences might explain the global pulmonary root dilatation when subjected to systemic pressure, particularly at the level of the sinotubular junction which might result in the autograft failure. Differences in the asymmetrical expansion of the aortic and pulmonary roots should be considered for the implantation of the pulmonary autograft in the most physiological position.