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.

Pathogenetic importance and therapeutic implications of NF-κB in lymphoid malignancies

Derangement of the nuclear factor κB (NF-κB) pathway initiates and/or sustains many types of human cancer. B-cell malignancies are particularly affected by oncogenic mutations, translocations, and copy number alterations affecting key components the NF-κB pathway, most likely owing to the pervasive role of this pathway in normal B cells. These genetic aberrations cause tumors to be 'addicted' to NF-κB, which can be exploited therapeutically. Since each subtype of lymphoid cancer utilizes different mechanisms to activate NF-κB, several different therapeutic strategies are needed to address this pathogenetic heterogeneity. Fortunately, a number of drugs that block signaling cascades leading to NF-κB are in early phase clinical trials, several of which are already showing activity in lymphoid malignancies.

A pilot study of evaluation of a phosphorylation signature from pancreatic cancer tumors

e14584

Background: The development of targeted therapy in pancreatic cancer has been hindered by minimal material available for molecular analysis from diagnostic endoscopic ultrasound-guided fine-needle aspirations (EUS/FNA). Revealing the phosphorylation status of key pathway mediators would allow optimal selection of patients for kinase inhibitor clinical trials. We launched a pilot study to evaluate the feasibility of detecting phosphorylation signatures from FNA samples using an ultrasensitive multiplexed protein microarray platform (CEER, Prometheus). Methods: Patients who underwent routine diagnostic EUS/FNA for a suspicious lesion in the pancreas underwent two additional EUS passes. Mediators of multiple signaling pathways including HER1/EGFR, HER2, HER3, IGF-IR, and their downstream mediators, AKT, MEK, ERK, et al were evaluated by CEER. Circulating tumor cells (CTCs) and resected tumor specimens were collected as available from patients for comparison. Results: From January-September, 2011, 57 patients were enrolled with a planned final enrollment of 100. This is an interim analysis. Thirty-nine (68.4%) had carcinoma cytology, 9 had atypical and 9 had negative cytology. HER2 (median value of 18 CU vs. 2 CU, p = 0.021) and HER3 (median value of 547 CU vs. 168 CU, p = 0.008) showed significantly higher levels of phosphorylation in malignant FNAs over their counterparts with negative cytology. Robust levels of CK expression were also observed in FNAs with carcinoma cytology (median CK level 1030 CU vs. 106 CU, p = 0.007). The wide range of phosphorylation signatures detected indicates this is a feasible clinical approach. For example, the expression levels of phosphorylated PI3K were 16 (22.5% - low), 28 (39.4% - medium low), 23 (32.4% - medium high), and 2 (2.8% - high). The correlation of p PI3K between 2 passes was 0.59 (p = 0.018) based on the Spearman Correlation. A CEER comparison of FNA vs. surgical specimens and FNA vs. CTCs is forthcoming. Conclusions: Profiling the phosphorylation status of pancreatic cancer pathways from FNA samples is feasible. If further validated, patients with pancreatic cancer can be screened for targeted therapy by their phosphorylation signature.

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.

Neoadjuvant therapy of pancreatic cancer: the emerging paradigm?

Pancreatic cancer remains one of the deadliest cancers due to difficulty in early diagnosis and its high resistance to chemotherapy and radiation. It is now clear that even patients with potentially resectable disease require multimodality treatment including chemotherapy and/or radiation to improve resectability and reduce recurrence. Tremendous efforts are currently being invested in refining preoperative staging to identify optimal surgical candidates, and also in developing various neoadjuvant or adjuvant regimens to improve surgical outcome. Although at present no studies have been done to directly compare the benefit of neoadjuvant versus adjuvant approaches, accumulating evidence suggests that the neoadjuvant approach is probably beneficial for a subset of the patient population, particularly those with borderline resectable disease in which complete surgical resection is almost certainly unachievable. In this article, we review the literature and rationales of neoadjuvant chemotherapy and chemoradiation, as well as their potential limitations and caveats. We also review the pathological findings following neoadjuvant therapies, and potential surgical complications that may be associated with neoadjuvant therapies.

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.

RALA and RALBP1 regulate mitochondrial fission at mitosis

Mitochondria exist as dynamic interconnected networks that are maintained through a balance of fusion and fission¹. Equal distribution of mitochondria to daughter cells during mitosis requires fission². Mitotic mitochondrial fission depends upon both the relocalization of large GTPase Drp1 to the outer mitochondrial membrane and phosphorylation of S616 on Drp1 by the mitotic kinase cyclin B/Cdk1². We now report that these processes are mediated by the small Ras-like GTPase RalA and its effector RalBP1 (RLIP76/RLIP1/RIP1)^3,4. Specifically, the mitotic kinase Aurora A phosphorylates S194 of RalA, relocalizing it to the mitochondria, where it concentrates RalBP1 and Drp1. Furthermore, RalBP1 associates with cyclin B/Cdk1 kinase activity to foster phosphorylation of Drp1 on S616. Disrupting either RalA or RalBP1 leads to a loss of mitochondrial fission at mitosis, improper segregation of mitochondria during cytokinesis and a decrease in ATP levels and cell number. Thus, the two mitotic kinases Aurora A and cyclin B/Cdk1 converge upon RalA and RalBP1 to promote mitochondrial fission, the appropriate distribution of mitochondria to daughter cells and ultimately proper mitochondrial function.

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.

Sec5 and Exo84 foster oncogenic ras-mediated tumorigenesis

The genes encoding the Ras family of small GTPases are mutated to yield constitutively active GTP-bound oncogenic proteins in one third of all human cancers. Oncogenic Ras binds to and activates a number of proteins that promote tumorigenic phenotypes, including the family of Ral guanine nucleotide exchange factors (RalGEF). Activated RalGEFs convert the Ral family of small GTPases, composed of RalA and RalB, from an inactive GDP-bound state to an active GTP-bound state. As both RalA and RalB have been implicated in a variety of tumorigenic phenotypes, we sought to determine which proteins downstream of Rals promote transformation and tumorigenesis. Here, we report that shRNA-mediated knockdown of the Ral effector proteins Sec5 and Exo84, but less so in the case of RalBP1, reduced oncogenic RalGEF-mediated transformation and oncogenic Ras-driven tumorigenic growth of human cells. These results suggest that Rals promote oncogenic Ras-mediated tumorigenesis through, at least in part, Sec5 and Exo84.

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.

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.

The cytoplasmic deacetylase HDAC6 is required for efficient oncogenic tumorigenesis

Histone deacetylase inhibitors (HDACI) are promising antitumor agents. Although transcriptional deregulation is thought to be the main mechanism underlying their therapeutic effects, the exact mechanism and targets by which HDACIs achieve their antitumor effects remain poorly understood. It is not known whether any of the HDAC members support robust tumor growth. In this report, we show that HDAC6, a cytoplasmic-localized and cytoskeleton-associated deacetylase, is required for efficient oncogenic transformation and tumor formation. We found that HDAC6 expression is induced upon oncogenic Ras transformation. Fibroblasts deficient in HDAC6 are more resistant to both oncogenic Ras and ErbB2-dependent transformation, indicating a critical role for HDAC6 in oncogene-induced transformation. Supporting this hypothesis, inactivation of HDAC6 in several cancer cell lines reduces anchorage-independent growth and the ability to form tumors in mice. The loss of anchorage-independent growth is associated with increased anoikis and defects in AKT and extracellular signal-regulated kinase activation upon loss of adhesion. Lastly, HDAC6-null mice are more resistant to chemical carcinogen-induced skin tumors. Our results provide the first experimental evidence that a specific HDAC member is required for efficient oncogenic transformation and indicate that HDAC6 is an important component underlying the antitumor effects of HDACIs.

Oncogenic Ras-induced secretion of IL6 is required for tumorigenesis

Ras is mutated to remain in the active oncogenic state in many cancers. As Ras has proven difficult to target therapeutically, we searched for secreted, druggable proteins induced by Ras that are required for tumorigenesis. We found that Ras induces the secretion of cytokine IL6 in different cell types, and that knockdown of IL6, genetic ablation of the IL6 gene, or treatment with a neutralizing IL6 antibody retard Ras-driven tumorigenesis. IL6 appears to act in a paracrine fashion to promote angiogenesis and tumor growth. Inhibiting IL6 may therefore have therapeutic utility for treatment of cancers characterized by oncogenic Ras mutations.

Oncogenic Ras-induced secretion of IL6 is required for tumorigenesis

Ras is mutated to remain in the active oncogenic state in many cancers. As Ras has proven difficult to target therapeutically, we searched for secreted, druggable proteins induced by Ras that are required for tumorigenesis. We found that Ras induces the secretion of cytokine IL6 in different cell types, and that knockdown of IL6, genetic ablation of the IL6 gene, or treatment with a neutralizing IL6 antibody retard Ras-driven tumorigenesis. IL6 appears to act in a paracrine fashion to promote angiogenesis and tumor growth. Inhibiting IL6 may therefore have therapeutic utility for treatment of cancers characterized by oncogenic Ras mutations.

Divergent roles for RalA and RalB in malignant growth of human pancreatic carcinoma cells

BACKGROUND

The Ral guanine nucleotide-exchange factors (RalGEFs) serve as key effectors for Ras oncogene transformation of immortalized human cells. RalGEFs are activators of the highly related RalA and RalB small GTPases, although only the former has been found to promote Ras-mediated growth transformation of human cells. In the present study, we determined whether RalA and RalB also had divergent roles in promoting the aberrant growth of pancreatic cancers, which are characterized by the highest occurrence of Ras mutations.

RESULTS

We now show that inhibition of RalA but not RalB expression universally reduced the transformed and tumorigenic growth in a panel of ten genetically diverse human pancreatic cancer cell lines. Despite the apparent unimportant role of RalB in tumorigenic growth, it was nevertheless critical for invasion in seven of nine pancreatic cancer cell lines and for metastasis as assessed by tail-vein injection of three different tumorigenic cell lines tested. Moreover, both RalA and RalB were more commonly activated in pancreatic tumor tissue than other Ras effector pathways.

CONCLUSIONS

RalA function is critical to tumor initiation, whereas RalB function is more important for tumor metastasis in the tested cell lines and thus argues for critical, but distinct, roles of Ral proteins during the dynamic progression of Ras-driven pancreatic cancers.

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.

Use of retrovirus expression of interfering RNA to determine the contribution of activated K-Ras and ras effector expression to human tumor cell growth

Cancer is a multistep genetic process that includes mutational activation of oncogenes and inactivation of tumor suppressor genes. The Ras oncogenes are the most frequently mutated oncogenes in human cancers (30%), with a high frequency associated with cancers of the lung, colon, and pancreas. Mutational activation of Ras is commonly an early event in the development of these cancers. Thus, whether mutated Ras is required for tumor maintenance and what aspects of the complex malignant phenotype might be promoted by mutated Ras are issues that remain unresolved for these and other human cancers. The recent development of interfering RNA to selectively impair expression of mutated Ras provides a powerful approach to begin to resolve these issues. In this chapter, we describe the use of retrovirus-based RNA interference approaches to study the functions of Ras and Ras effectors (Raf, RalA, RalB, and Tiam1) in the growth of pancreatic carcinoma and other human tumor cell lines. Finally, we also compare the use of constitutive and inducible shRNA expression vectors for analyses of mutant Ras function.

Reduction in the requirement of oncogenic Ras signaling to activation of PI3K/AKT pathway during tumor maintenance

While tumors become addicted to oncogenes like Ras, the microenvironment in which tumor cells reside changes during tumorigenesis; the cells are surrounded initially by normal tissue and later by tumor tissue. Hence, we asked if Ras exerts its oncogenic effects through the same set of effectors during different stages of tumorigenesis. We now show in human cells that the Ras effector pathways MAPK, RalGEF, and PI3K are required to initiate tumor growth. Conversely, activation of the PI3K/AKT pathway replaced Ras once tumors formed, although other effectors were still activated independently of Ras, presumably by factors provided upon the establishment of a tumor microenvironment. Thus, as tumorigenesis progresses the addiction of cancers to their initiating oncogene is reduced to, at least in the case of Ras, the PI3K/AKT pathway.

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.

Activation of RalA is critical for Ras-induced tumorigenesis of human cells

RalGEFs were recently shown to be critical for Ras-mediated transformed and tumorigenic growth of human cells. We now show that the oncogenic activity of these proteins is propagated by activation of one RalGEF substrate, RalA, but blunted by another closely related substrate, RalB, and that the oncogenic signaling requires binding of the RalBP1 and exocyst subunit effector proteins. Knockdown of RalA expression impeded, if not abolished, the ability of human cancer cells to form tumors. RalA was also commonly activated in a panel of cell lines from pancreatic cancers, a disease characterized by activation of Ras. Activation of RalA signaling thus appears to be a critical step in Ras-induced transformation and tumorigenesis of human cells.

Leveling the Playing Field

Using a genetically malleable model system that allows direct comparisons between human and mouse cells, Weinberg and colleagues lay to rest any doubt that murine cells are more easily transformed than human cells, and additionally, find that there may be cell type constraints on transformation of human cells.

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.

One-stage coronary and abdominal aortic operation with or without cardiopulmonary bypass: early and midterm follow-up

BACKGROUND

The aim of this study was to compare hospital, early, and late clinical outcomes for patients undergoing one-stage, coronary and abdominal aortic surgical intervention with and without cardiopulmonary bypass.

METHODS

From March 1990 to September 1999, 42 consecutive patients underwent combined operations at a single institution. Cardiopulmonary bypass and cardioplegic arrest were used during coronary revascularization in the first 20 patients (on-pump group), and the next 22 patients received the one-stage operations on the beating heart (off-pump group).

RESULTS

Baseline characteristics were similar between groups. Three cardiac-related hospital deaths occurred in the on-pump group and one such death in the off-pump group (p = 0.25). Cardiac-related events, pulmonary complications, inotropic support, blood loss and transfusion requirements, intensive care unit stay, and hospital stay were significantly reduced in the off-pump group (all, p < 0.05). The actuarial survival rates in the on-pump and off-pump groups were 80% and 95%, respectively, at 1 year (p = 0.13) and 75% and 89%, respectively, at 3 years (p = 0.22). Freedom from cardiac-related events at 1-year follow-up was 91% in the off-pump group and 65% in the on-pump group (p < 0.05). No difference in cardiac-related events between groups was observed at 3 years.

CONCLUSIONS

Off-pump coronary surgical procedures decrease postoperative complications in high-risk patients undergoing simultaneous coronary and abdominal aortic operations compared with the conventional one-stage procedure. The early benefits achieved with off-pump surgical intervention are not at the expense of the long-term clinical outcome.

Community-acquired pneumonia in patients requiring hospitalization

OBJECTIVE

This study aimed to investigate the microbial aetiology of community-acquired pneumonia (CAP) in patients requiring hospitalization.

METHODOLOGY

A prospective study of consecutive non-immunocompromised patients aged 12 years and above admitted with CAP from August 1997 to May 1999 was undertaken.

RESULTS

Of 127 patients hospitalized for CAP, an aetiological diagnosis was achieved in 53 cases (41.7%). Klebsiella pneumoniae was the most frequently isolated pathogen and caused 10.2% of all the cases, followed by Streptococcus pneumoniae (5.5%), Haemophilus influenzae (5.5%), Mycoplasma pneumoniae (3.9%) and Pseudomonas aeruginosa (3.9%). Gram-negative bacilli were significantly more frequently identified in patients aged 60 years or older and in patients with comorbid illnesses. Twelve of 13 patients who died from CAP had other comorbid illnesses compared to 63 of 114 patients who survived (P = 0.014). Three of eight bacteraemic patients died compared with 10 of 119 non-bacteraemic patients (P = 0.035).

CONCLUSIONS

The microbiology of CAP in patients requiring hospitalization in Malaysia appears to be different from that in Western countries. Gram-negative bacilli were more frequently isolated in older patients and in those with comorbidity. Mortality from CAP is more likely in patients with comorbidity and in those who are bacteraemic.

Occlusive myocardial infarction: investigation of bis-gadolinium mesoporphyrins-enhanced T1-weighted MR imaging in a cat model

PURPOSE

To test whether bis-gadolinium mesoporphyrins-enhanced magnetic resonance (MR) imaging can accurately depict irreversibly damaged myocardium in occlusive myocardial infarction.

MATERIALS AND METHODS

Ten cats were subjected to 90 minutes of occlusion of the left anterior descending coronary artery. Bis-gadolinium mesoporphyrins-enhanced T1-weighted MR imaging was performed in the cats for 6 hours. Histopathologic examinations with 2'3'5-triphenyl tetrazolium chloride (TTC) staining and electron microscopy were performed on the resected specimens. The time course and pattern of signal intensity enhancement were evaluated. The size of the infarcted myocardium was estimated on the MR images by measuring the size of the signal intensity-enhanced area.

RESULTS

In eight of 10 cats, it was impossible to distinguish infarcted myocardium from normal myocardium at visual inspection of T1-weighted MR images. The contrast ratio between infarcted and normal myocardium did not increase significantly over time. In one of the two remaining cats, a doughnut pattern of signal intensity enhancement was noted. The other cat showed intensely homogeneous enhancement of infarcted myocardium at MR imaging. The size of the area of signal intensity enhancement at MR imaging in these two cats was accurately mapped to that of the infarction on the TTC-stained specimens.

CONCLUSION

Occlusive myocardial infarction cannot be accurately detected at bis-gadolinium mesoporphyrins-enhanced MR imaging.

Relationship between symptoms and objective measures of airway obstruction in asthmatic patients

The objective of this study was to determine the relationship between asthma symptoms and the degree of airway obstruction as measured by the forced expiratory volume in one second (FEV1) and peak expiratory flow rate (PEFR) in a group of 64 asthmatic patients with clinically stable disease attending a university-based urban asthma clinic. Asthma symptoms did not correlate with the degree of airway obstruction as measured by prebronchodilator PEFR (total asthma symptom score vs PEFR: r = -0.214, p = 0.104, n = 59) and only correlated poorly with prebronchodilator FEV1 (total asthma symptom score vs FEV1: r = -0.256, p = 0.041, n = 64). These results lend support to the recommendation that airway obstruction should be measured objectively when assessing patients with chronic persistent asthma.

Histocompatibility leukocyte antigen-G is not expressed by endometriosis or endometrial tissue

OBJECTIVE

The immunological mechanisms that support persistence and proliferation of ectopic endometrial implants within the peritoneal cavity of women with endometriosis are unknown. Inhibition of natural killer (NK) and cytotoxic T-cell function has been proposed as a mechanism. We tested the hypothesis that expression of a nonclassical major histocompatibility antigen, HLA-G, might explain the local immunosuppression associated with ectopic endometrium.

DESIGN

Nested case-control study of women with and without laparoscopic evidence of endometriosis.

SETTING

Reproductive endocrinology clinic at a university hospital.

PATIENT(S)

Peritoneal fluid specimens from 10 women with revised AFS stage I-IV endometriosis and from 10 age-matched normal controls without laparoscopic evidence of endometriosis were tested for the presence of HLA-G protein. Endometriosis and normal endometrial biopsies from four patients were used to prepare stromal cell cultures directly evaluated for HLA-G protein.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The expression of HLA-G in peritoneal fluid, tissue, and cell cultures was determined by immunoblotting with a specific monoclonal antibody.

RESULT(S)

HLA-G protein was not detectable in peritoneal fluid specimens of endometriosis patients or controls. Moreover, ectopic and normal endometrial tissues and stromal cells did not express HLA-G.

CONCLUSION(S)

Immune cell inhibition in endometriosis must be mediated by factors other than HLA-G.

Awake respiratory function in patients with the obstructive sleep apnoea syndrome

INTRODUCTION

The flow-volume curves of patients with obstructive sleep apnoea (OSA) obtained during the awake state are frequently abnormal.

OBJECTIVE

To determine 1) the relationship between the awake respiratory function and the severity of sleep-disordered breathing in a group of Malaysian patients with the OSA syndrome and 2) the frequency of flow-volume curve abnormality in these patients.

MATERIALS AND METHODS

A retrospective analysis of the data from respiratory function tests during wakefulness and nocturnal polysomnography was performed on 48 patients with OSA. The severity of OSA was defined by the apnoea-hypopnoea index (AHI) and the lowest oxygen saturation during sleep (SpO2nadir).

RESULTS

AHI had a significant relationship with alveolar-arterial oxygen gradient (r = 0.34, p = 0.046) and SpO2nadir (r = -0.49, p < 0.001) but not with any anthropometric parameter or the other awake respiratory function variables measured. SpO2nadir had a significant relationship with body mass index (r = -0.54, p < 0.001), neck circumference (r = -0.39, p = 0.013), awake room air PaO2 (r = 0.61, p < 0.001), alveolar-arterial oxygen gradient (r = -0.41, p = 0.015) and baseline supine SpO2 (r = 0.53, p < 0.001). There was no correlation between SpO2nadir and any spirometric or static lung volume parameters. The maximum inspiratory and maximum expiratory flow-volume curves of 26 patients (54%) showed a ratio of forced expiratory flow to forced inspiratory flow at mid-vital capacity (FEF50/FIF50) greater than one. In addition, flow oscillations (the "sawtooth" sign) were noted in the inspiratory and/or expiratory flow-volume curves of 21 patients (44%), 9 of whom did not have an FEF50/FIF50 > 1. Altogether, the maximum flow-volume curves during wakefulness of 35 (73%) of the 48 patients showed variable upper airway obstruction and/or flow oscillations. However, the presence of these two upper airway abnormalities, either occurring alone or together did not have an effect on the severity of OSA as measured by the AHI or SpO2nadir.

CONCLUSIONS

Abnormalities of the flow-volume loop consistent with inspiratory flow limitation and/or upper airway instability during wakefulness are common in patients with the OSA syndrome. The degree of oxygen desaturation during sleep in these patients is related to their awake oxygenation status.

Lung cancer in patients younger than 40 years in a multiracial Asian country

OBJECTIVE

This study aimed to determine whether the clinicopathological features of lung cancer in patients younger than 40 years differ from that of older patients in an Asian country.

METHODOLOGY

We undertook a review of the clinicopathological data of all patients with confirmed primary lung cancer at the Department of Medicine, University of Malaya Medical Centre, Kuala Lumpur, Malaysia, from October 1991 to September 1999.

RESULTS

Of the 580 patients with lung cancer, 36 (6.2%; 23 males, 13 females) were 21-39 years old at diagnosis. The percentage of people who had never smoked was higher among the younger patients (58.3% vs 19.1%, P < 0.001). Although adenocarcinoma was the most common cell type in both groups, its incidence was higher in the younger patients (24/36 (66.7%) vs 228/544 (41.9%), P = 0.007). The mean World Health Organization performance status at presentation was worse in the younger patients (2.4 vs 2, P = 0.007). In the case of non-small cell lung cancer, all the younger patients presented with either stage IIIb or metastatic disease compared to 77.2% of the older patients (P < 0.001).

CONCLUSIONS

Younger lung cancer patients were more likely than older patients to have never smoked, to have adenocarcinoma, and to present with poorer performance status and with more advanced-stage non-small cell lung cancer.

Placental peroxisome proliferator-activated receptor-gamma is up-regulated by pregnancy serum

Lipid metabolism plays an important role in normal pregnancy adaptation and in pathological pregnancy (e.g. preeclampsia). In the current studies we examined the expression of peroxisome proliferator-activated receptor-gamma (PPARgamma) in tissues and cells relevant to human pregnancy. We found that PPARgamma is expressed in placental cytotrophoblasts in vivo and in trophoblasts (primary and choriocarcinoma cells) and fetal endothelial cells in vitro. We characterized primary cytotrophoblasts and two cell lines with which to study PPARgamma regulation in human pregnancy. Like primary cytotrophoblasts, the choriocarcinoma cell line JEG-3 has endogenous PPARgamma expression. Normal positive and negative PPARgamma regulation was observed in the latter cells. We also created a new JEG-3-derived cell line (EP-JEG) by stable insertion of a PPAR response element-luciferase reporter gene construct. Together, these cell lines are useful for studying PPARgamma expression and activation in human trophoblasts. We examined PPARgamma regulation in these cells by human serum and found that PPARgamma protein expression and activation are dramatically increased by sera from pregnant women. Preliminary characterization of the regulatory principle(s) is consistent with a prostanoid or fatty acid derivative. The results suggest that increased activation of PPARgamma may play an important role in maternal metabolism during human pregnancy.