Volatile Organic Compound-Based Predictive Modeling of Smoke Taint in Wine

Smoke taint in wine has become a critical issue in the wine industry due to its significant negative impact on wine quality. Data-driven approaches including univariate analysis and predictive modeling are applied to a data set containing concentrations of 20 VOCs in 48 grape samples and 56 corresponding wine samples with a taster-evaluated smoke taint index. The resulting models for predicting the smoke taint index of wines are highly predictive when using as inputs VOC concentrations after log conversion in both grapes and wines (Pearson Correlation Coefficient PCC = 0.82; R2 = 0.68) and less so when only grape VOCs are used (Pearson Correlation Coefficient PCC = 0.76; R2 = 0.56), and the classification models also show the capacity for detecting smoke-tainted wines using both wine and grape VOC concentrations (Recall = 0.76; Precision = 0.92; F1 = 0.82) or using only grape VOC concentrations (Recall = 0.74; Precision = 0.92; F1 = 0.80). The performance of the predictive model shows the possibility of predicting the smoke taint index of the wine and grape samples before fermentation. The corresponding code of data analysis and predictive modeling of smoke taint in wine is available in the Github repository (https://github.com/IBPA/smoke_taint_prediction).

Audit lead selection and yield prediction from historical tax data using artificial neural networks

Tax audits are a crucial process adopted in all tax departments to ensure tax compliance and fairness. Traditionally, tax audit leads have been selected based on empirical rules and randomization methods, which are not adaptive, may miss major cases and can introduce bias. Here, we present an audit lead tool based on artificial neural networks that have been trained and evaluated on an integrated dataset of 93,413 unique tax records from 8,647 restaurant businesses over 10 years in the Northern California, provided by the California Department of Tax and Fee Administration (CDTFA). The tool achieved a 40.1% precision and 58.7% recall (F1-score of 0.42) on classifying positive audit leads, and the corresponding regressor provided estimated audit gains (MAE of $155,490). Finally, we evaluated the statistical significance of various empirical rules for use in lead selection, with two out of five being supported by the data. This work demonstrates how data can be leveraged for creating evidence-based models of audit selection and validating empirical hypotheses, resulting in higher audit yields and more fair audit selection processes.

Human Breathomics Database

Breathomics is a special branch of metabolomics that quantifies volatile organic compounds (VOCs) from collected exhaled breath samples. Understanding how breath molecules are related to diseases, mechanisms and pathways identified from experimental analytical measurements is challenging due to the lack of an organized resource describing breath molecules, related references and biomedical information embedded in the literature. To provide breath VOCs, related references and biomedical information, we aim to organize a database composed of manually curated information and automatically extracted biomedical information. First, VOCs-related disease information was manually organized from 207 literature linked to 99 VOCs and known Medical Subject Headings (MeSH) terms. Then an automated text mining algorithm was used to extract biomedical information from this literature. In the end, the manually curated information and auto-extracted biomedical information was combined to form a breath molecule database—the Human Breathomics Database (HBDB). We first manually curated and organized disease information including MeSH term from 207 literatures associated with 99 VOCs. Then, an automatic pipeline of text mining approach was used to collect 2766 literatures and extract biomedical information from breath researches. We combined curated information with automatically extracted biomedical information to assemble a breath molecule database, the HBDB. The HBDB is a database that includes references, VOCs and diseases associated with human breathomics. Most of these VOCs were detected in human breath samples or exhaled breath condensate samples. So far, the database contains a total of 913 VOCs in relation to human exhaled breath researches reported in 2766 publications. The HBDB is the most comprehensive HBDB of VOCs in human exhaled breath to date. It is a useful and organized resource for researchers and clinicians to identify and further investigate potential biomarkers from the breath of patients.

Database URL: https://hbdb.cmdm.tw

Social support, self-efficacy and their correlation among patients with Type 2 Diabetes Mellitus: A primary care perspective

INTRODUCTION

Social support and self-efficacy are factors that influence patients' health behaviour. However, the relationship between these two factors among patients with Type 2 Diabetes Mellitus (T2DM) has not been adequately explored. This study aims to report social support and selfefficacy of Malaysian T2DM patients, and their correlations.

METHODS

This cross-sectional questionnaire study involved 329 patients with T2DM who received their follow up at a public primary care clinic. Patients were selected via systematic random sampling. Patients self-completed locally adapted versions of the Medical Outcomes Study (MOS) Social Support Survey and Diabetic Management Self Efficacy Scale (DMSES). The scores of both tools were analysed to determine the association and correlation between social support and self-efficacy.

RESULTS

The mean score for overall social support was 72.7±21.40 score range (0-100). "Affectionate support" was rated the highest averaged mean score at 78.31±23.71 (score range: 0-100). The mean DMSES score was 147.6±35.5 (score range :0-200), of which "medications" subscale was rated the highest with averaged mean scores 9.07±1.67 (score range: 0-10). Overall social support and self-efficacy were found to be weakly correlated (r=0.197, p<0.001). However, all subscales of social support were moderately correlated with "medications" subscale of self-efficacy.

CONCLUSION

Social support is significantly associated with patients' self-efficacy in handling their own medications.

Web Server for Peak Detection, Baseline Correction, and Alignment in Two-Dimensional Gas Chromatography Mass Spectrometry-Based Metabolomics Data

Two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC/TOF-MS) is superior for chromatographic separation and provides great sensitivity for complex biological fluid analysis in metabolomics. However, GC×GC/TOF-MS data processing is currently limited to vendor software and typically requires several preprocessing steps. In this work, we implement a web-based platform, which we call GC²MS, to facilitate the application of recent advances in GC×GC/TOF-MS, especially for metabolomics studies. The core processing workflow of GC²MS consists of blob/peak detection, baseline correction, and blob alignment. GC²MS treats GC×GC/TOF-MS data as pictures and clusters the pixels as blobs according to the brightness of each pixel to generate a blob table. GC²MS then aligns the blobs of two GC×GC/TOF-MS data sets according to their distance and similarity. The blob distance and similarity are the Euclidean distance of the first and second retention times of two blobs and the Pearson's correlation coefficient of the two mass spectra, respectively. GC²MS also directly corrects the raw data baseline. The analytical performance of GC²MS was evaluated using GC×GC/TOF-MS data sets of Angelica sinensis compounds acquired under different experimental conditions and of human plasma samples. The results show that GC²MS is an easy-to-use tool for detecting peaks and correcting baselines, and GC²MS is able to align GC×GC/TOF-MS data sets acquired under different experimental conditions. GC²MS is freely accessible at http://gc2ms.web.cmdm.tw .

Swallowed Foreign Bodies in Children: Report of Four Unusual Cases

Introduction: Although a majority of ingested foreign bodies (FBs) pass down the gastrointestinal tract spontaneously, those that are sharp, pointed or large in size need removal to avert serious complications. We highlight the urgent need and utility of endoscopic accessories and technical artistry in safe retrieval of FBs in children. Clinical Picture: Four children had accidentally swallowed a nail, metallic dumbbell, open safety pin and a cushion pin respectively. They were symptom-free and the abdominal plain radiographs revealed foreign body in the stomach in all the cases. Treatment: Oesophago-gastro-duodenoscopy (OGD) was done in all the patients and could retrieve the nail, metallic dumbbell and open safety pin successfully using a Dormia basket, a polypectomy snare and a pair of rat-tooth forceps respectively. The cushion pin had migrated to the duodeno-jejunal junction within 4 hours of ingestion and necessitated open duodenotomy and retrieval. Outcome: All patients did well after the procedure with no complications. Conclusions: Swallowed FBs with pointed or sharp ends or large enough to cross the pylorus and duodenal sweep need removal and in the majority of the cases they can be retrieved by OGD. Sharp or pointed FBs that have crossed the second part of the duodenum necessitate urgent laparotomy for retrieval to prevent complications. Key words: Complications, Ingestion, Treatment

Swallowed foreign bodies in children: report of four unusual cases

INTRODUCTION

Although a majority of ingested foreign bodies (FBs) pass down the gastrointestinal tract spontaneously, those that are sharp, pointed or large in size need removal to avert serious complications. We highlight the urgent need and utility of endoscopic accessories and technical artistry in safe retrieval of FBs in children.

CLINICAL PICTURE

Four children had accidentally swallowed a nail, metallic dumbbell, open safety pin and a cushion pin respectively. They were symptom-free and the abdominal plain radiographs revealed foreign body in the stomach in all the cases.

TREATMENT

Oesophago-gastro-duodenoscopy (OGD) was done in all the patients and could retrieve the nail, metallic dumbbell and open safety pin successfully using a Dormia basket, a polypectomy snare and a pair of rat-tooth forceps respectively. The cushion pin had migrated to the duodeno-jejunal junction within 4 hours of ingestion and necessitated open duodenotomy and retrieval.

OUTCOME

All patients did well after the procedure with no complications.

CONCLUSIONS

Swallowed FBs with pointed or sharp ends or large enough to cross the pylorus and duodenal sweep need removal and in the majority of the cases they can be retrieved by OGD. Sharp or pointed FBs that have crossed the second part of the duodenum necessitate urgent laparotomy for retrieval to prevent complications.

Duodenal duplication cyst communicating with an aberrant pancreatic duct

Duodenal duplication cyst (DDC) is an uncommon congenital anomaly and is the rarest site for intraabdominal duplications. We report a case of DDC communicating with an aberrant pancreatic duct in a 2-year-old girl, with features of possible occult relapsing pancreatitis. The duplication cyst was successfully enucleated with excision of the aberrant pancreatic duct. The literature is reviewed, and the diagnostic modalities and management options are discussed.

The lipoprotein lipase S447X polymorphism and plasma lipids

We studied 4,058 subjects from a representative sample of the Singapore population 1) to determine the association between the S447X polymorphism at the LPL locus and serum lipid concentration in Chinese, Malays, and Asian Indians living in Singapore and 2) to explore any interactions with apolipoprotein E (APOE) genotype, exercise, obesity, cigarette smoking, and alcohol intake. Information on obesity, lifestyle factors (including smoking, alcohol consumption, and exercise frequency), glucose tolerance, and fasting lipids was obtained. Male and female carriers of the X447 allele had lower serum triglyceride concentrations and higher HDL cholesterol (HDL-C) concentrations. The association between the X447 allele and serum HDL-C concentration was modulated by APOE genotype in males and cigarette smoking and alcohol intake in females. The effect of the X447 allele was greatest in men who carried the E4 allele and women who smoked or consumed alcohol. The X447 allele at the LPL locus is common and associated with a less atherogenic lipid profile in Asian populations. Interactions with APOE genotype, cigarette smoking, and alcohol intake reinforce the importance of examining genetic associations, such as this one, in the context of the population of interest.

Do Singapore patients require lower doses of statins? The SGH Lipid Clinic experience

A substantial number of physicians in Asian countries believe that Asian patients need lower doses of statins to achieve therapeutic lipid target because of the smaller size of patients. This belief is deep rooted and we looked at the SGH Lipid Clinic to determine if our experience bears out this belief. Between 1996 and August 2000, the Lipid Unit treated a total of 841 patients, of which 548 patients (77.5% Chinese, 12.1% Malays, 7.6% Asian Indians; 49.6% males, 50.4% females; 54.7% diabetics, 45.3% non-diabetic) were on statins alone. These patients had > or =2 coronary risk factors, diabetes mellitus or documented coronary heart disease. The pre-treatment lipid levels or the worst lipid levels available were entered as the baseline lipid values (mean LDL-C: 5.38+1.5 mmol/l). Duration of therapy ranged from six months to five years. The choice and titration of statins were determined by attending physicians. The median statin dose (Simvastatin equivalent) was 20.0 mg with 52.5% requiring 20 mg or more. Statin dose did not differ between diabetic and non-diabetic subjects. The median statin dose was 15 mg for the lower two tertiles and 20 mg for the upper tertile; this difference did not achieve statistical significance. The reduction in LDL cholesterol was 41.5% (40.1-42.8) and total cholesterol was 33.0% (32.9-34.1). Only 25% of our patients achieved LDL cholesterol of less than 2.6 mmol/l whilst 77.5% had LDL cholesterol less than 3.4 mmol/l. Our experience at the Lipid Clinic suggests that the Asian patients require similar statin doses to achieve target cholesterol levels.

APOE polymorphism and lipid profile in three ethnic groups in the Singapore population

BACKGROUND

Serum lipid concentrations are modulated by environmental factors such as exercise, alcohol intake, smoking, obesity and dietary intake and genetic factors. Polymorphisms at the Apolipoprotein E (APOE) locus have consistently shown a significant association with total and LDL-cholesterol (LDL-C). However, their impact on HDL-cholesterol (HDL-C) may be population dependent. Having three major ethnic groups within a similar social environment allows us to study the role of genetics and their interactions with lifestyle factors on the serum lipid profile and coronary risk in Asians.

METHODS

This study included 1740 males (1146 Chinese, 327 Malays and 267 Asian Indians) and 1950 females (1329 Chinese, 360 Malays and 261 Asian Indians) with complete data on anthropometric indices, fasting lipids, smoking status, alcohol consumption, exercise frequency and genotype at the APOE locus.

RESULTS

Malays and Asian Indians were more obese compared with the Chinese. Smoking was uncommon in all females but Malay males had significantly higher prevalence of smokers. Malays had the highest LDL-C whilst Indians had the lowest HDL-C, The epsilon 3 allele was the most frequent allele in all three ethnic groups. Malays had the highest frequency of epsilon 4 (0.180 and 0.152) compared with Chinese (0.085 and 0.087) and Indians (0.108 and 0.075) in males and females, respectively. The epsilon 2 allele was the least common in Asian Indians. Total cholesterol (TC) and LDL-C was highest in epsilon 4 carriers and lowest in epsilon 2 carriers. The reverse was seen in HDL-C with the highest levels seen in epsilon 2 subjects. The association between ethnic group and HDL-C differed according to APOE genotype and gender. Asian Indians had the lowest HDL-C for each APOE genotype except in Asian Indian males with epsilon 2, where HDL-C concentrations were intermediate between Chinese and Malays.

CONCLUSION

Ethnic differences in lipid profile could be explained in part by the higher prevalence of epsilon 4 in the Malays. Ethnicity may influence the association between APOE genotypes and HDL-C. APOE genotype showed no correlation with HDL-C in Malay males whereas the association in Asian Indians was particularly marked. Further studies of interactions between genes and environmental factors will contribute to the understanding of differences of coronary risk amongst ethnic groups.

Statin therapy and small fibre neuropathy: a serial electrophysiological study

We describe three patients who developed small fibre neuropathy after 1 month of statin therapy with clinical resolution upon prompt drug withdrawal. All patients showed abnormal sympathetic skin responses (SSR) in comparison with controls. SSRs returned to normal in tandem with clinical improvement. One patient redeveloped small and large fibre neuropathy when the similar drug was readministered. The SSR is of value in the electrophysiological assessment and follow-up of statin-related small fibre neuropathy.

The TaqIB and -629C>A polymorphisms at the cholesteryl ester transfer protein locus: associations with lipid levels in a multiethnic population. The 1998 Singapore National Health Survey

The Singapore population comprises Chinese, Malays and Asian Indians. Within this population, Asian Indians have the highest rates of coronary heart disease, whereas Chinese have the lowest. Conversely, Indians have the lowest high-density lipoprotein cholesterol (HDL-C) concentrations, followed by Malays and Chinese. We studied the TaqIB and -629C>A polymorphisms at the CETP locus in 1300 Chinese, 364 Malay and 282 Asian Indian men, and in 1558 Chinese, 397 Malay and 306 Asian Indian women, to determine whether these polymorphisms are responsible for the ethnic difference in HDL-C concentration. The frequency of the B2 allele in Chinese, Malays and Indians was 0.384, 0.339 and 0.449 in men, and 0.379, 0.329 and 0.415 in women, respectively (p < 0.001). For the A-629 allele, the relative frequencies were 0.477, 0.423 and 0.592 in men and 0.486, 0.416 and 0.575 in women (p < 0.001). The two polymorphisms were in linkage disequilibrium (D / Dmax= 0.9772, p < 0.00001). The B2 and the A-629 alleles were associated with increased HDL-C concentrations in a dose-dependent manner. The B2 allele continued to show an association with HDL-C concentration, even after controlling for the genotype at position -629. Dietary cholesterol showed a significant interaction with the TaqIB polymorphism in determining HDL-C concentrations in Indians and Malays, but not in Chinese. In conclusion, the high frequencies of these polymorphisms in Asian Indians could not explain the observed ethnic differences in HDL-C concentration. Moreover, we observed an ethnic-specific interaction among dietary cholesterol, the TaqIB polymorphism and HDL-C concentrations.

New clues for the developing human biliary system at the porta hepatis

The human biliary system is formed from the hepatic diverticulum, a structure which develops from the embryonic foregut in the fourth week of gestation. The cephalic portion of the hepatic diverticulum lies within the septum transversum, and gives rise to entodermal cells which become the primitive hepatocytes. The caudal part of the hepatic diverticulum is molded by mesenchyme to form the gallbladder, cystic duct, and extrahepatic bile duct. The gallbladder is initially tubular in shape, and undergoes morphological changes to become saccular during the 11th week of gestation. The extrahepatic bile duct elongates and widens as gestation progresses, and intramural mucus glands develop. There is no solid stage during the development of the extrahepatic bile duct. The extrahepatic bile duct is a well-defined tubular structure by the 6th week of gestation, whereas the intrahepatic biliary system during this period of gestation is represented by the primitive ductal plate. The ductal plate undergoes structural changes from the 11th week of gestation, beginning at the porta hepatis and progressing through gestation to the periphery of the liver. This remodeling process shapes the ductal plate from a flat sheath of biliary epithelium surrounding the portal vein branches into a network of interconnecting tubular structures. Mesenchyme plays an important role in ductal plate remodeling. The intrahepatic biliary system is in luminal continuity with the extrahepatic bile duct throughout gestation at the porta hepatis. The major bile ducts at the porta hepatis are fully formed by the 16th week of gestation.

Anti-oxidant ebselen causes the resolution of experimentally induced hepatic fibrosis in rats

BACKGROUND

Hepatic fibrosis occurs because of injury to the liver parenchyma and biliary system. We have investigated the effect of an organic selenium anti-oxidant, ebselen, in the resolution of experimentally induced hepatic fibrosis, and evaluated its effect on various paradigms involved in hepatic fibrosis.

METHODS

Following pretreatment with phenobarbitone, liver fibrosis was induced in male Fischer 344 rats by using carbon tetrachloride treatment for 10 weeks. Carbon tetrachloride-treated rats were randomly assigned into two groups: (i) no ebselen; and (ii) ebselen administered for 3 weeks following a 10-week carbon tetrachloride treatment period. Normal controls were: (i) neither carbon tetrachloride nor ebselen treated; or (ii) ebselen treated for 13 weeks. Liver sections were stained with hematoxylin and eosin, Masson trichrome and stained for reticulin by using silver impregnation. Reverse transcription-polymerase chain reaction was used to analyze the steady-state levels of gene(s) involved in: (i) hepatic fibrosis, namely, transforming growth factor-beta1, procollagen I and III, tissue inhibitor of metalloproteinase-1 and matrix metalloproteinase-13; (ii) oxidative stress, namely, cytochrome P4502E1; and (iii) preneoplastic liver foci, namely, the placental form of glutathione-S-transferase.

RESULTS

Histological staining showed that ebselen resolves carbon tetrachloride-induced hepatic fibrosis. Treatment with ebselen reduced steady-state levels of transforming growth factor-beta1, procollagen I and III, tissue inhibitor of metalloproteinase-1, cytochrome P4502E1 and placental form glutathione-S-transferase transcripts, and increased transcripts of matrix metalloproteinase-13.

CONCLUSION

These findings provide evidence that ebselen significantly causes the resolution of carbon tetrachloride-induced hepatic fibrosis in rats.

The prognostic value of ductal plate malformation and other histologic parameters in biliary atresia: an immunohistochemical study

Ductal plate malformation, a term given to intrahepatic bile ducts that retain the fetal configuration, is observed in some cases of biliary atresia. We examined 21 livers from patients with biliary atresia; ductal plate malformation occurred in 38% of cases, and its presence was predictive of poor clinical outcome (P =.04).

Protection of salvia miltiorrhiza against aflatoxin-B1-induced hepatocarcinogenesis in Fischer 344 rats dual mechanisms involved

Extract of Salvia Miltiorrhiza (SM) has been widely used in traditional Chinese medicine for treating liver diseases. Recent experimental evidence indicates that it has anti-tumor potential. In this study, the effect of SM on alfatoxin B1 (AFB1)-induced hepatocarcinogenesis was investigated in male Fischer 344 rats. AFB1 (40 microg/100 g body wt, by gavage) was administered once a week for 24 weeks. In SM treatment group, rats were given SM (0.25g/100g body wt, 5 days/week by gavage) for a total of 28 weeks, including 4 weeks before and 24 weeks during AFB1 exposure. Results showed that the elevation of serum alanine aminotransferase and aspartate aminotransferase activities due to AFB1 dosing was almost completely abolished by the treatment of SM, indicating that SM could prevent AFB1-induced liver cell injury. It was further observed that SM substantially reduced glutathione S-transferase placenta form (GST-P) positive foci formation and GST-P mRNA expression caused by AFB1, which clearly suggests that SM is effective in preventing AFB1-induced hepatocarcinogenesis. Furthermore, the inhibition on AFB1 hepatocarcinigenesis was associated with a corresponding decrease in AFB1-DNA adducts formation as well as AFB1-induced oxidative DNA damage (8-hydroxydeoxyguanosine) in rat liver. Our results also indicate that the protective effect of SM might be mediated through dual mechanisms: (i) the enhancement of AFB1 detoxification pathway, especially the induction of GST-Yc2 mRNA expression, and (ii) the antioxidant property of SM.

Compound heterozygous familial hypercholesterolemia and familial defective apolipoprotein B-100 produce exaggerated hypercholesterolemia

BACKGROUND

Familial hypercholesterolemia (FH) and familial defective apolipoprotein B-100 (FDB) represent ligand-receptor disorders that are complementary. Individuals with both FH and FDB are unusual. We report a family with both disorders and the impact of the mutations on the phenotypes of the family members.

METHODS

We used single strand conformation polymorphism (SSCP) and denaturing gradient gel electrophoresis (DGGE) for genetic analysis of all 18 exons and the promoter region of the LDL receptor and DGGE for genetic analysis of the apolipoprotein B-100 (apo B-100) gene. The functional significance of the apo B-100 mutation was studied using a U937 cell proliferation assay. Fasting serum lipid profiles were determined for the index case and seven first-degree relatives.

RESULTS

One of the patient's sisters had a missense mutation (Asp(407)-->Lys) in exon 9 of the LDL receptor and a serum LDL-cholesterol concentration of 4.07 mmol/L. Four other first-degree relatives had hyperlipidemia but no LDL-receptor mutation. However, these subjects had a mutation of the apo B-100 gene (Arg(3500)-->Trp). The cell proliferation rate of U937 cells fed with LDL from other subjects with the same mutation was fourfold less than that of controls. The index case had both FH- and FDB-related mutations. Her serum LDL-cholesterol (9.47 mmol/L) was higher than all other relatives tested.

CONCLUSIONS

Existence of both FH and FDB should be considered in families with LDL-receptor mutations in some but not all individuals with hypercholesterolemia or when some individuals in families with FH exhibit exaggerated hypercholesterolemia.

Diabetes mellitus abolishes ethnic differences in cardiovascular risk factors: lessons from a multi-ethnic population

AIMS

To compare cardiovascular risk factors in diabetic subjects of different ethnic groups, and between new and known diabetic subjects, in the Singapore National Health Survey '92.

METHODS

Disproportionate stratified sampling followed by systematic sampling were used in 3568 (total) respondents of whom 2743 were non-diabetics, 179 newly diagnosed diabetics and 150 known diabetics. Amongst the diabetics, there were 185 Chinese, 66 Malays and 78 Asian Indians. Diagnosis of diabetes mellitus (DM) was based on the 2 h glucose alone, after a 75 g oral glucose tolerance test. Blood pressure (BP), lipid profile, glucose, insulin and anthropometric indices were obtained from all subjects.

RESULTS

Subjects with diabetes (new and known) exhibited significantly higher triglyceride (TG), lower high density lipoprotein cholesterol (HDL-C) and low density lipoprotein (LDL)/apolipoprotein B (apo B) ratio (LDL size) compared with normoglycaemic subjects. They were more obese (generalised and central) and had higher systolic and diastolic BP. There was no difference in lipid risk factors between the two groups with diabetes although those with new diabetes were more obese whilst those with known diabetes had higher fasting glucose. Amongst subjects with diabetes, there were no significant differences between ethnic groups in TG, HDL-C, LDL/apo B ratio, or waist to hip ratio (WHR). Female Malays with diabetes had higher total cholesterol and were more obese whilst male Asian Indians with diabetes had higher fasting insulin.

CONCLUSION

Asian Indians had lower HDL-C and LDL/apo B ratio than Chinese or Malays amongst normoglycaemic subjects. However, these differences between ethnic groups were not seen in subjects with DM.

Cardiovascular risk factors and LDL subfraction profile in Type 2 diabetes mellitus subjects with good glycaemic control

OBJECTIVES

To compare cardiovascular risk factors and LDL particle size in well-controlled Type 2 diabetes mellitus and normal subjects.

METHODS

Ninety-three Type 2 diabetic males and 186 age-matched, male controls were studied. Glycaemic control was stable for at least 3 months prior to recruitment. None were on insulin or lipid lowering therapy. Anthropometric indices, blood pressure, lipids, glucose, insulin, apolipoprotein A1 and B, LDL subfraction by density ultracentrifugation were obtained after an overnight fast of 10 h.

RESULTS

Diabetic subjects (mean HbA(1c) 6.6%+/-0.10) did not differ from controls in total cholesterol levels (5.04+/-0.08 vs. 5.16+/-0.05 mmol/l, respectively) but had lower serum HDL cholesterol (0.98+/-0.03 vs. 1.12+/-0.02 mmol/l, P<0.001), higher serum triglyceride (2.38+/-0.16 vs. 1.80+/-0.08 mmol/l, P<0.001), lower LDL(1) and LDL(2) and higher LDL(3) concentration. An LDL(3) concentration exceeding 100 mg/dl was found in 59.1% of diabetics and 39.1% of non-diabetics (P<0.001). Diabetic subjects also had higher body mass index, waist to hip ratio and insulin resistance (HOMA). Difference in LDL subfraction between groups disappeared after adjustments were made for either triglyceride or HDL cholesterol.

CONCLUSION

Well controlled Type 2 diabetes mellitus subjects exhibit an increased cardiovascular burden through low HDL cholesterol and predominance of small, dense LDL particles.

Benefits of micronised Fenofibrate in type 2 diabetes mellitus subjects with good glycemic control

AIMS

To determine the effects of micronised fenofibrate on lipids and low density lipoprotein (LDL) subfraction in well-controlled diabetic subjects with mild elevations in cholesterol levels.

METHODS

Thirty-five male type 2 diabetic subjects with LDL(3) greater than 100 mg/dl and good glycemic control (mean HbA1c 6.7%) were treated with micronised fenofibrate in an open labeled study for 6 months. Anthropometric indices, blood pressure, lipids, glucose, insulin, apolipoprotein A-I and B, and LDL subfraction by density ultracentrifugation were obtained after an overnight fast of 10 h, at the beginning and end of the 6 months treatment period.

RESULTS

The blood pressure, waist to hip ratio, body mass index and glycemic control remained unchanged throughout the 6 months study period. Mean serum triglyceride fell from 2.49 to 1.72 mmol/l (33%) whilst HDL cholesterol increased from 0.88 to 0.96 mmol/l (10.8%). There were no significant changes in total or LDL cholesterol. Both LDL(1) and LDL(2) rose significantly whilst the dense LDL(3) fell from a mean of 148 to 85 mg/dl (43% reduction). Fenofibrate changed the LDL subfraction distribution from dense LDL(3) particles towards buoyant LDL(1) and LDL(2) particles in 63% of the subjects. No subjects had elevations in transaminases greater than three-fold or creatine kinase greater than ten-fold from pre-treatment levels.

CONCLUSION

Diabetic subjects with mild hypercholesterolemia and good glycemic control may benefit from therapy with micronised fenofibrate because of the reduction in serum triglyceride, elevation in HDL cholesterol and a shift in LDL subfraction towards a non-atherogenic form.

In the absence of dietary surveillance, chitosan does not reduce plasma lipids or obesity in hypercholesterolaemic obese Asian subjects

OBJECTIVE

To investigate the effects of Absorbitol on body weight, anthropometry, body composition, blood pressures and lipid profiles in obese, hypercholesterolaemic subjects without dietary restriction.

DESIGN

A randomised, double blind. Placebo-controlled study.

SUBJECTS

Normal volunteers with no history of chronic illnesses (n=88) who were obese (body fat percentage > 20% in males and > 30% in females) and hypercholesterolaemic (total cholesterol > 5.20 mmol/L). Sixty-eight (72.3%) subjects completed the study.

INTERVENTION

After a 4 week run in phase, 4 placebo/Absorbitol (250 mg) capsules were prescribed 3 times a day before meals. Subjects received written information on healthy lifestyle but there was no dietary restriction or monitoring.

MAIN OUTCOME MEASURES

Weight, body mass index, lean body mass, waist, hip, blood pressure, fasting lipids and insulin levels were taken at baseline, 4th and 16th week of the study.

STATISTICAL ANALYSIS PERFORMED

Analyses were on an intention-to-treat basis. Comparisons between groups were made using Student's t and Mann-Whitney tests for parametric and non-parametric data respectively.

RESULTS

There was no significant change in the measured parameters in Absorbitol treated subjects compared to those on placebo, with exception of HDL-cholesterol which increased in the absorbitol group and decreased in the placebo group (p=0.048). The side effects of Absorbitol were also comparable to that of placebo.

CONCLUSIONS

In the absence of dietary surveillance, Absorbitol does not bring about improvement in weight, anthropometry, body composition, blood pressure or lipid profile.

Inhibition of ebselen on aflatoxin B(1)-induced hepatocarcinogenesis in Fischer 344 rats

Aflatoxin B(1) (AFB(1)), a potent hepatocarcinogen, enhances ROS formation and causes oxidative DNA damage, which may play a role in its carcinogenicity. We have demonstrated recently that ebselen, an organic selenium compound, protects against the cytotoxicity of AFB(1) through its antioxidant capability. The present study was designed to investigate the effect of ebselen on AFB(1)-induced hepatocarcinogenesis in an animal model. Fischer 344 rats were first treated with either deionized water or ebselen (5 mg/kg, 5 days/week) via gavage for 4 weeks, then given AFB(1) (0.4 mg/kg, gavage, once a week) or AFB(1) plus ebselen (5 mg/kg, 5 days/week) for another 24 weeks. The results showed that the hepatocarcinogenicity of AFB(1) in rats was significantly reduced by ebselen treatment as indicated by a decrease in: (i) serum gamma-glutamyl transpeptidase activity; (ii) expression of mRNAs of liver alpha-fetoprotein and the placental form of glutathione S-transferase (GST-P); and (iii) the area and mean density of staining of liver GST-P foci. Ebselen treatment significantly reduced the formation of hepatic AFB(1)-DNA adducts and 8-hydroxydeoxyguanosine caused by AFB(1) exposure. These findings suggest that ebselen can inhibit the carcinogenicity of AFB(1). In addition to the reduction of AFB(1)-DNA adduct formation, the protective effect of ebselen against AFB(1)-induced oxidative DNA damage may also, at least in part, contribute to its anticarcinogenic property.

Screening for diabetes mellitus--a two-step approach in individuals with impaired fasting glucose improves detection of those at risk of complications

AIMS

To compare the new American Diabetes Association (ADA) fasting plasma glucose (FPG) criteria to the 1985 World Health Organization (WHO) 2-h post glucose (2hPG) criteria when used for screening of those with no prior history of diabetes mellitus.

METHODS

The study included 3,407 subjects without a history of diabetes in whom both FPG and 2hPG were available from the 1992 Singapore National Health Survey. The agreement (kappa) between FPG and 2hPG for the diagnosis of DM was assessed. The optimal cut-off of FPG for the detection of individuals with 2hPG > or = 11.1 mmol/l was determined by receiver-operating characteristics analysis.

RESULTS

The prevalence of diabetes diagnosed by FPG alone was 7.3% compared to 8.4% diagnosed by 2hPG. The prevalence of impaired fasting glucose was 8.0%. FPG and 2hPG showed moderate agreement (kappa = 0.646, 95% confidence interval 0.584-0.708). Age, ethnic group and obesity did not affect the degree of agreement. Of those with 2hPG > or = 11.1 mmol/l, 40.8% had FPG in the non-diabetic range while 24.8% of those with FG > or = 7.0 mmol/l had 2hPG in the non-diabetic range. The optimal FPG for the detection of 2hPG > or =11.1 mmol/l was 6.1 mmol/l. Oral glucose tolerance tests (OGTT) in those with 6.0 mmol/ < FPG < 7.0 mmol/l resulted in the diagnosis of diabetes in 90.7% of individuals at risk of microvascular complications.

CONCLUSIONS

FPG provides a simple screening test for diabetes, which shows moderate agreement with the 2hPG. A two-step strategy of OGTT in those with impaired fasting glucose improves the detection of at-risk individuals. However, diabetes should not be diagnosed on a single test. The test should be repeated on another day if an individual tests positive for diabetes.

Homeostasis model assessment in a population with mixed ethnicity: the 1992 Singapore National Health Survey

We studied insulin resistance and beta-cell function with reference to ethnic group, glucose tolerance and other coronary artery disease risk factors in a cross section of the Singapore population which comprises Chinese, Malays and Asian Indians. 3568 individuals aged 18-69 were examined. Blood pressure, anthropometric data, blood lipids, glucose and insulin were assayed in the fasting state. Glucose and serum insulin were measured 2 h after an oral glucose challenge. Insulin resistance and beta-cell function were calculated using homeostasis model assessment. Asian Indians had higher insulin resistance than Chinese or Malays. Impaired glucose tolerance (IGT) and diabetes mellitus (DM) were associated with greater insulin resistance and impaired beta-cell function compared to normal glucose tolerance (NGT). Insulin resistance was positively correlated with blood pressure in women and total cholesterol, LDL cholesterol and triglyceride in both men and women. It was negatively correlated with HDL cholesterol and LDL/apolipoprotein B ratio. beta-cell function showed no significant correlations with the cardiovascular risk factors studied. It appears that both impaired beta-cell function and insulin resistance are important for the development of hyperglycemia whereas insulin resistance alone seems more important in the development of coronary artery disease as it correlates with several known coronary artery disease risk factors.

Body fat distribution and cardiovascular risk in normal weight women. Associations with insulin resistance, lipids and plasma leptin

OBJECTIVE

To systematically examine the correlations between insulin resistance, plasma leptin concentration, obesity and the distribution of fat assessed by anthropometry and magnetic resonance imaging in Asian women.

DESIGN

A cross sectional study of non-diabetic, normal weight women.

SUBJECTS

Twenty-one healthy women aged 38.8 y (s.d. 11.7) and BMI 22.6 kg/m2 (s.d. 2.3).

MEASUREMENTS

Intraperitoneal, retroperitoneal and subcutaneous abdominal fat volume was assessed by magnetic resonance imaging. Anthropometric data were collected. Total fat mass was assessed by bioelectric impedance analysis. Fasting serum lipids, insulin and plasma leptin were assayed.

RESULTS

Generalized obesity correlated with subcutaneous abdominal fat mass (r=0.83, P<0.001), but not with intra-abdominal fat mass. Both intraperitoneal fat mass and retroperitoneal fat mass increased with age (r=0.58, P=0.005 and r=0. 612, P=0.003, respectively). Abdominal subcutaneous fat mass was the most important determinant of insulin resistance and plasma leptin. Of the serum lipids, only fasting triglyceride correlated significantly with the waist-to-hip ratio.

CONCLUSIONS

It is possible that the large size of the subcutaneous depot compared to the intra-abdominal depot overwhelms any metabolic differences between adipose tissue from these two sites, resulting in the stronger correlation between insulin resistance and subcutaneous abdominal fat mass rather than intra-abdominal fat mass. On the other hand, the distribution of fat between subcutaneous fat depots may be important in the metabolic syndrome given the correlation of fasting triglyceride with waist to hip ratio but not with abdominal fat. However, the study population was small, younger and leaner compared to previous studies and we may not be able to generalize these results to all segments of the population. We confirm that subcutaneous fat mass is the major determinant of plasma leptin.

Cardiovascular risk profile in individuals with borderline glycemia: the effect of the 1997 American Diabetes Association diagnostic criteria and the 1998 World Health Organization Provisional Report

OBJECTIVE

In 1997, the American Diabetes Association (ADA) recommended a new diagnostic category, impaired fasting glucose (IFG), to describe individuals with borderline glucose tolerance. On the other hand, the World Health Organization (WHO) suggested retaining the category of impaired glucose tolerance (IGT). We studied the prevalence of IFG and IGT in a multiethnic society and compared the cardiovascular risk profiles of subjects with IFG, IGT, or both IFG and IGT.

RESEARCH DESIGN AND METHODS

A total of 3,568 subjects were examined from the 1992 National Health Survey of Singapore, which involved a combination of disproportionately stratified sampling and systematic sampling. Anthropometric, blood pressure, insulin, lipid profile, and uric acid measurements were taken, and a standard 75-g oral glucose tolerance test was performed after a 10-h overnight fast.

RESULTS

The prevalence rates of IFG only, IGT only, and both IFT and IGT were 3.45, 10.2, and 3.4%, respectively. The degree of agreement (kappa) between the two diagnostic criteria (the ADA IFG and the WHO IGT) was only 0.25. A fasting glucose level of 5.5 mmol/l was the optimal cutoff for predicting a 2-h postload glucose level of > or =7.8 mmol/l. The following cardiovascular risk factors were higher in subjects with both IFG and IGT compared with those with either IFG or IGT alone: systolic blood pressure (131 +/- 20 vs. 125 +/- 21 and 125 +/- 19 mmHg, respectively; P < 0.05 and P < 0.001, respectively); diastolic blood pressure (77 +/- 12 vs. 73 +/- 12 and 74 +/- 12 mmHg, respectively; P < 0.05); BMI (26.2 +/- 4.2 vs. 24.4 +/- 4.0 and 24.6 +/- 4.4 kg/m2, respectively; P < 0.01 and P < 0.001, respectively); waist circumference (84.1 +/- 10.3 vs. 79.3 +/- 10.7 and 79.3 +/- 10.6 cm, respectively; P < 0.001); waist-to-hip ratio (0.84 +/- 0.08 vs. 0.82 +/- 0.09 and 0.81 +/- 0.08, respectively; P < 0.05 and P < 0.001, respectively); fasting insulin (12.1 +/- 9.7 vs. 9.2 +/- 5.3 and 9.9 +/- 7.7 mU/l; P < 0.01); insulin resistance (by homeostasis model assessment [HOMA]) (3.41 +/- 2.77 vs. 2.58 +/- 1.50 and 2.43 +/- 1.83, respectively; P < 0.01 and P < 0.001, respectively); total cholesterol (5.81 +/- 1.1 vs. 5.51 +/- 1.1 and 5.53 +/- 1.1 mmol/l, respectively; P < 0.05) and apolipoprotein(B) [apo(B)] (1.5 +/- 0.38 vs. 1.40 +/- 0.34 and 1.39 +/- 0.35 mmol/l, respectively; P < 0.01). The pattern of difference remained significant only for fasting insulin, insulin resistance (HOMA), and apo(B) (borderline) after adjustment for age, sex, and ethnic differences.

CONCLUSIONS

Obvious discordance was evident in the classification of glycemic status when applying the criteria proposed by the ADA (IFG) or WHO (IGT) in a multiethnic society like Singapore. However, subjects with either IFG or IGT had similar cardiovascular risk profiles. Therefore, both criteria identified individuals at high risk for cardiovascular disease. Individuals with both IFG and IGT had a greater incidence of the cardiovascular dysmetabolic syndrome.

A man with osteoblastic metastasis and hypocalcaemia

We report a case of an 80-year-old man with osteoblastic metastases from advanced carcinoma of the prostate presenting with a grand mal seizure resulting from severe hypocalcaemia. He had low serum phosphate and ionised calcium levels, elevated serum skeletal alkaline phosphatase and intact parathormone levels. 99mTc radioisotope bone scan revealed a "super bone scan" suggestive of osteomalacia. The serum 1, 25-dihydroxycholecalciferol level was unexpectedly elevated. The biochemical abnormalities persisted despite high dose calcium replacement, but improved with supraphysiological doses of 1,25 (OH)2 vitamin D3 (Rocaltrol) therapy. We hypothesise that the hypocalcaemia in this patient was due to vitamin D resistance secondary to a humoral factor secreted by the tumour.

Making the diagnosis of biliary atresia using the triangular cord sign and gallbladder length

BACKGROUND

To evaluate the accuracy and utility of the triangular cord sign and gallbladder length in diagnosing biliary atresia by sonography.

MATERIALS AND METHODS

Sixty fasted infants with cholestatic jaundice aged 2-12 weeks were examined sonographically using a 5-10 MHz linear array transducer, focusing on the triangular cord sign (as described by Choi et al. [1]), the gallbladder, and ducts. The triangular cord is defined as a triangular or tubular echogenic density seen immediately cranial to the portal vein bifurcation; it represents the fibrotic remnant of the obliterated cord in biliary atresia. The findings were blinded to blood chemistry, (99 m)Tc-DISIDA hepatobiliary scintigraphy, and liver biopsy. Diagnosis of biliary atresia was confirmed at surgery and histology. Non-biliary atresia infants resolved medically. Comparative charges of the various investigations was made.

RESULTS

++ Twelve infants had biliary atresia, and ten demonstrated a definite triangular cord. The two false-negatives had small or nonvisualized gallbladders. No false-positives were recorded. Gallbladder length ranged from 0-1.45 cm with a mean of 0. 52 cm in biliary atresia compared to a mean of 2.39 cm in nonbiliary atresia infants. (99 m)Tc-DISIDA hepatobiliary scintigraphy showed no excretion (false-positive) in 23 % of nonbiliary atresia cases. Scintigraphy and liver biopsy charges were 2 and 6 times that of sonography, respectively.

CONCLUSION

The triangular cord sign and gallbladder length together are noninvasive, inexpensive, and very useful markers for biliary atresia.

Isolated low HDL cholesterol: an insulin-resistant state only in the presence of fasting hypertriglyceridemia

Individuals with isolated low HDL cholesterol are at increased risk of coronary artery disease. It has been reported previously that this is an insulin-resistant state. We analyzed data from the 1992 Singapore National Health Survey with the objective of defining the clinical and metabolic parameters associated with isolated low HDL cholesterol. A total of 3,568 individuals were selected by stratified random sampling. Subjects with low HDL cholesterol (<0.9 mmol/l) and "ideal" total cholesterol (<5.2 mmol/l) were identified. Data on anthropometry, blood pressure (BP), insulin resistance, glucose tolerance, sex, smoking habit, and ethnic group were examined. We found that this group was heterogeneous. Those with fasting triglyceride (TG) >1.7 mmol/l (low HDL/high TG) displayed features of the insulin resistance syndrome characterized by obesity, higher diastolic BP, greater insulin resistance, and a greater tendency to have diabetes or impaired glucose tolerance (IGT). If fasting TG was <1.7 mmol/l (isolated low HDL cholesterol), individuals were similar to the general population in terms of insulin resistance and obesity. Both groups were more commonly men and Asian Indian. The ethnic difference in prevalence could not be explained by differences in diet, exercise, alcohol ingestion, or smoking. Our data support the view that Asian Indians are genetically predisposed to isolated low HDL cholesterol as well as the insulin resistance syndrome. The higher prevalence of isolated low HDL cholesterol, the young age at which individuals exhibit this phenotype (mean age 32.5 years), along with the greater propensity for Asian Indians to develop insulin resistance and IGT contribute to the threefold increased incidence of myocardial infarction in those <65 years of age in this ethnic group.

Measurement of obesity by anthropometry and bioelectric impedance analysis: correlation with fasting lipids and insulin resistance in an Asian population

Obesity is associated with increased coronary artery disease risk. This is at least partially mediated by increased prevalence of other risk factors such as dyslipidaemia and insulin resistance. Various anthropometric indices have been used to quantify generalised and central obesity. Correlations between these measurements and risk factors are specific to the population and findings cannot be extrapolated to other ethnic groups. Bioelectric impedance analysis (BIA) is a simple means of estimating percentage body fat. We compared body mass index (BMI), waist circumference, waist-hip ratio (WHR) and percentage body fat measure by BIA as predictors of fasting lipid profiles and insulin resistance in 109 Singaporean Chinese. BMI was significantly correlated with insulin resistance and there appeared to be a threshold at 26 kg/m2 above which the regression line became more steep. WHR best predicted fasting triglyceride in both men and women. In women, it was inversely correlated with high density lipoprotein cholesterol. A similar association was seen in men but this did not reach statistical significance. We conclude that measurement of BMI and WHR should be part of the assessment of cardiovascular risk in our population as they connote different aspects of risk. BIA was not found to be a useful tool for the prediction of coronary artery disease risk factors in our population.

A study in the relationships between leptin, insulin, and body fat in Asian subjects

OBJECTIVE

To study the relationship of leptin concentrations with indices of obesity, fasting insulin, insulin resistance and lipid profiles (total cholesterol, low density lipoprotein (LDL)-cholesterol, high density lipoprotein (HDL)- cholesterol and triglyceride) in an Asian cohort.

DESIGN

Cross sectional study.

SUBJECTS

A total of 133 healthy volunteers were enrolled (64 female: age: 25-61 y, body mass index (BMI): 18.7-45.1 kg/m2 and 69 male: age: 25-61 y, BMI: 19.3-35.0 kg/m2).

MEASUREMENTS

Weight, height, waist and hip circumferences, blood pressure, lean body mass (by bioelectric impedence analysis (BIA)), plasma leptin and lipid profiles were taken after a 10 h fast.

RESULTS

Percentage of body fat measured by bioelectric impedance was the strongest determinant of plasma leptin (r = 0.844, P < 0.0001). Females had higher leptin concentrations than males for the same fat mass. In a multiple linear regression model, body fat percentage, (percentage body fat* gender), hip circumference and fasting insulin were significant determinants of leptin concentration (r = 0.882, P < 0.0001).

CONCLUSION

Leptin concentration correlated closely with percentage body fat in Asian subjects. Hip circumference as a corollary for peripheral obesity, was better associated with leptin than waist circumference or waist-to-hip ratio (WHR). Distribution of fat in females tended to be peripheral and may partly explain the gender difference. Fasting insulin level and central obesity were correlated with HDL-cholesterol, triglyceride and blood pressure, while fasting leptin had little correlation with these metabolic parameters. Therefore, insulin resistance was a better guide to cardiovascular risk assessment than plasma leptin.

A study to assess the effect of dietary supplementation with soluble fibre (Minolest) on lipid levels in normal subjects with hypercholesterolaemia

Hypercholesterolaemia is one of the major risk factors in the development of coronary artery disease. In recent years, many nonprescription treatments have become available for cholesterol lowering. Minolest is a product that contains guar gum and psyllium as the principal active ingredients. We conducted a randomised, placebo-controlled, double-blind, parallel-group study to assess the efficacy of Minolest as a lipid-lowering agent. Secondary aims included assessment of the effect on blood pressure and obesity. We also looked at the acceptability of the product and side effects associated with its ingestion. After a 4-week run-in period, 83 subjects were randomised to receive placebo or Minolest (16.5 g/day) for 3 months. Seven subjects defaulted follow up, 5 in the placebo group and 2 in the active treatment group. In addition, 9 subjects (5 on active treatment and 4 on placebo) had total cholesterol fall into the optimal range (< 5.2 mmol/l) during the run-in phase and were removed from the study. At baseline in the active treatment group, total cholesterol was 6.1 (5.43 to 8.06) mmol/l, triglyceride 1.54 (0.56 to 4.19) mmol/l, HDL cholesterol 1.32 +/- 0.43 mmol/l and LDL cholesterol 4.1 (3.10 to 6.27) mmol/l. In the placebo group, total cholesterol was 5.84 (5.32 to 8.38) mmol/l, triglyceride 1.47 (0.69 to 11.0) mmol/l, HDL cholesterol 1.15 +/- 0.33 mmol/l and LDL cholesterol 3.87 (2.46 to 5.14) mmol/l. The differences in the baseline characteristics were not statistically significant except the LDL-cholesterol. Minolest produced a 3.24% (SD = 7.85%, P = 0.020) decrease in total cholesterol and 5.45% decrease in LDL cholesterol (SD = 10.25%, P = 0.0034) but no significant difference in serum triglyceride, weight, body mass index or blood pressure. This was not seen in the placebo group. The percentage fall in LDL cholesterol increased to 7.16% and 7.37% in subjects who consumed at least 50% and 70% of the treatment respectively. There were few side effects. The authors conclude that this product has a small impact on the lipid profile and may be useful only in subjects with mild hypercholesterolaemia and a low risk of coronary artery disease.

Prevalence of diabetes and ethnic differences in cardiovascular risk factors. The 1992 Singapore National Health Survey

OBJECTIVE

The purpose of the 1992 Singapore National Health Survey was to determine the current distribution of major noncommunicable diseases and their risk factors, including the prevalence of diabetes and dyslipidemia, in Singapore.

RESEARCH DESIGN AND METHODS

A combination of disproportionate stratified sampling and systematic sampling were used to select the sample for the survey. The final number of respondents was 3,568, giving a response rate of 72.6%. All subjects fasted for 10 h and were given a 75-g glucose load, except those known to have diabetes. Blood was taken before and 2 h after the glucose load. Diagnosis of diabetes was based on 2-h glucose alone.

RESULTS

The age-standardized prevalence of diabetes in Singapore residents aged 18-69 years was 8.4%, with more than half (58.5%) previously undiagnosed. Prevalence of diabetes was high across all three ethnic groups. The prevalence of impaired glucose tolerance was 16.1%, that of hypertension was 6.5%, and 19.0% were regular smokers. The total cholesterol (mean +/- SD) of nondiabetic Singaporeans was 5.18 +/- 1.02 mmol/l; 47.9% had cholesterol > 5.2 mmol/l, while 15.4% had levels > 6.3 mmol/l. Mean LDL cholesterol was 3.31 +/- 0.89 mmol/l; HDL cholesterol was 1.30 +/- 0.32 mmol/l, and triglyceride was 1.23 +/- 0.82 mmol/l.

CONCLUSIONS

Prevalence of diabetes was high across all three ethnic groups. Ethnic differences in prevalence of diabetes, insulin resistance, central obesity, hypertension, smoking, and lipid profile could explain the differential coronary heart disease rates in the three major ethnic groups in Singapore.

Development of the human intrahepatic biliary system

In the development of the human biliary system, the extrahepatic bile ducts (EHBD) develop from the embryonic hepatic diverticulum, while the intrahepatic bile ducts (IHBD) originate within the liver from the ductal plate. The ductal plate is a flat muralium of primitive biliary epithelium that develops in the mesenchyme along the branches of the portal vein, by a process which requires a delicate balance between cell proliferation and death. The ductal plate is thus remodelled into the adult system of tubular anastomosing bile ducts and this process is called ductal plate remodelling. Computerised three-dimensional reconstruction of the developing ductal plate has shown that the ductal plate remodelling process starts at the porta hepatis around 11 weeks of gestation and progresses towards the periphery of the liver. The extrahepatic biliary system is in direct luminal continuity with the developing intrahepatic biliary system throughout gestation and does not have a "solid stage" as suggested previously. The ductal plate remodelling is controlled by many biochemical and molecular factors, some of which have been identified and studied. It has been suggested that abnormalities in the development of the IHBD could lead to a spectrum of diseases called ductal plate malformation. Biliary atresia is one of the conditions in this spectrum. Currently, we are studying the IHBD in biliary atresia in comparison to the normal developing IHBD, the results of which are presented in this review. Both morphologically and biochemically the IHBD in biliary atresia resembles the primitive foetal ductal plate suggesting a disruption in ductal plate remodelling.

Experimental models of hepatic fibrosis in the rat

The rat is a frequently used experimental model in studies involving human disease. We review several methods of inducing hepatic fibrosis and cirrhosis in rats. These include induction by hepatotoxins and hepatocarcinogens such as carbon tetrachloride, dimethylnitrosamine, thioacetamide and furan; the hepatoxin-cum-nutrient, alcohol; a high fat-low choline-low protein diet; immunologic agents such as heterologous serum or bacterial cell wall products; and obstructive jaundice and biliary cirrhosis by common bile duct ligation.

Salvia miltiorrhiza reduces experimentally-induced hepatic fibrosis in rats

BACKGROUND/AIMS

Hepatic fibrosis occurs as a result of injury to the liver parenchyma and biliary system. We have studied the effect of the traditional Chinese medicinal herb, Salvia miltiorrhiza, in an experimental model of hepatic fibrosis and evaluated its effect on various paradigms involved in hepatic fibrosis.

METHODS

Liver fibrosis was induced in male Wistar rats by chronic administration of carbon tetrachloride for 10 weeks. The carbon tetrachloride-treated rats were randomly assigned to three groups: no treatment, Salvia for 12 weeks from the onset of carbon tetrachloride treatment, and Salvia for 2 weeks after the completion of the 10-week course. The normal control groups in the study were: neither carbon tetrachloride nor Salvia, and Salvia only for 12 weeks. The livers were graded histologically and analyzed by reverse transcription-polymerase chain reaction for the transcription of genes involved in liver fibrosis, namely, transforming growth factor-beta1 and the extracellular matrix components procollagens I and III, tissue inhibitor of metalloproteinase-1 and matrix metalloproteinase-13. The transcripts were normalized against that of glyceraldehyde-3-phosphate dehydrogenase and analyzed statistically.

RESULTS

The histological evaluation showed that Salvia could reverse the fibrosis caused by carbon tetrachloride treatment. Rats treated with the herb had reduced levels of transforming growth factor-beta1, procollagens I and III and tissue inhibitor of metalloproteinase-1 transcripts and an increased level of matrix metalloproteinase-13 transcript, when compared to the disease control.

CONCLUSION

Salvia miltiorrhiza, a cheap and widely available herb, significantly reduces carbon tetrachloride-induced hepatic fibrosis in rats.

The effect of smoking on post-heparin lipoprotein and hepatic lipase, cholesteryl ester transfer protein and lecithin:cholesterol acyl transferase activities in human plasma

INTRODUCTION

Smoking is associated with dyslipidaemia, particularly raised plasma triglycerides and reduced high-density lipoprotein (HDL)-cholesterol and a delayed clearance of triglyceride in fat tolerance tests. The aim of this study was to investigate whether these phenomena could be explained by a reduced lipoprotein lipase activity in smokers.

METHODS

A group of 40 healthy individuals [plasma cholesterol 5.07 (SD 0.90) mmol L-1, plasma triglyceride 1.02 (SD 0.39) mmol L-1)] was studied to examine the effects of smoking on plasma enzyme activities, particularly post-heparin lipase activities. The group comprised 20 smokers and 20 non-smokers, who were matched for age, gender and body mass index (BMI).

RESULTS

Post-heparin lipoprotein lipase (LPL) activity [3.89 (SD 1.58) vs. 5.85 (SD 2.30) mumol free fatty acids (FFA) mL-1 h-1, P < 0.005], but not post-heparin hepatic lipase (HL) activity, was reduced in smokers. Plasma cholesteryl ester transfer protein (CETP) activity and lecithin: cholesterol acyl transferase (LCAT) activity were measured in a subgroup of 18 individuals, comprising nine smokers with nine matched non-smokers. There was no difference in CETP activities between two groups, but smokers had a significantly reduced plasma LCAT activity [112 (SD 23) vs. 152 (SD 24) nmol cholesterol mL-1 h-1, P < 0.005]. In both smokers (r=-0.53, P < 0.05) and non-smokers (r=-0.54, P < 0.05), HDL2 concentration was negatively associated with HL activity. In non-smokers, HDL3 concentration was negatively associated with CETP activity (r= -0.77, P < 0.05), whereas in smokers HDL3 concentration was negatively associated with LCAT activity (r= -0.78, P < 0.050).

CONCLUSION

It was shown by direct measurement that the activity of plasma post-heparin LPL is reduced in smokers, independently of age, gender and BMI. It is concluded that this enzyme perturbation associated with smoking may contribute to the development of the atherogenic lipoprotein phenotype seen in smokers.

Associations of indices of adiposity with atherogenic lipoprotein subfractions

OBJECTIVE

To investigate the associations of indices of adiposity with cardiovascular risk factors.

SUBJECTS

93 men and 98 women aged 18-69 y.

OUTCOME MEASURES

Body mass index (BMI), waist to hip ratio (WHR), waist circumference, waist to height ratio, blood pressure, fasting concentrations of blood glucose, insulin, plasma lipids and lipoprotein subfractions, apoproteins, lipoprotein(a) and post-heparin lipases.

RESULTS

BMI and waist showed similar associations (P < 0.01) with a cluster of major cardiovascular risk factors including total cholesterol, low density lipoprotein-cholesterol and very low density lipoprotein-cholesterol in men, and ratio of low density lipoprotein-/high density lipoprotein-cholesterol for both genders. Large waist circumference was significantly (P < 0.01) associated (controlled for age and smoking) with features of the metabolic syndrome, including raised insulin concentration (men: r=0.37, women: r=0.49), reduced high density lipoprotein2 (men: r=-0.30, women: r=-0.34), increased very low density lipoprotein1 mass (men: r=0.31, women: r=0.42), raised small, dense low density lipoprotein (men: r=0.30, women: r=0.31), elevated blood pressure (men: r=0.27, women: r=0.28), increased triglyceride (men: r=0.43, women: r=0.48) and apolipoprotein-B (men: r=0.32, women: r=0.35). Waist circumference also correlated with hepatic lipase/lipoprotein lipase ratio in women (r=0.52). Height adjustment did not substantially change relationships between waist circumference and risk factors. WHR correlated with fewer risk factors.

CONCLUSION

For the purpose of health promotion to prevent cardiovascular disease associated with overweight and intra-abdominal fat accumulation, the general public should be advised to be aware of the risk associated with large waist circumference.

Survey of aerobic bacterial infections in paediatric surgical intensive care unit patients

Infections cause a significant amount of morbidity and mortality in paediatric surgical patients requiring intensive care. The study aims to describe the epidemiology of infection among these patients, to correlate the source of infection with the underlying medical condition, and to determine the antibiotic sensitivity pattern of the organisms. Through a retrospective review over a period of one year, 133 cases were analysed. The overall incidence of infection was 35%. Those who had emergency surgery had the highest infection rate (47%). Respiratory tract infections were the commonest source of infection, and were associated with ventilator therapy rather than the underlying medical condition. The Enterobacteriaceae were the most common isolates seen. From antibiotic sensitivity tests, the empirical antibiotics of choice are gentamicin for suspected gram-negative infection and vancomycin for severe infections where methicillin-resistant Staphylococcus aureus is a likely cause. A high rate of resistance to ampicillin was seen and its use as a first-line monotherapy drug should be discontinued in our patient population.

A case report of a patient with bronchial carcinoid tumour and late presentation of Cushing's syndrome

Bronchial carcinoid tumour with ectopic adrenocorticotrophin (ACTH) production is an uncommon cause of Cushing's syndrome. In most instances, the patient presents with clinical hyperglucocorticolism and a search for its underlying pathology leads to the discovery of an inconspicuous bronchial carcinoid tumour, if at all. Often the tumour is not immediately detectable. We report a patient who presented in the reverse order--she initially had a large asymptomatic bronchial carcinoid tumour that subsequently manifested as clinical Cushing's syndrome after remaining quiescent for four years.

Developing human biliary system in three dimensions

BACKGROUND

In the development of the human biliary system, although the extrahepatic bile ducts develop from the embryonic hepatic diverticulum, there is increasing evidence to suggest that the intrahepatic bile ducts originate within the liver from the ductal plate. The ductal plate develops as a sheath of primitive biliary epithelium in the mesenchyme along the portal vein branches. Through an orderly process of selection and deletion, the ductal plate is remodelled into the adult system of anastomosing tubular bile ducts. The ductal plate remodelling process occurs at the porta hepatis between 11 and 13 weeks of gestation and progresses towards the periphery of the liver.

METHODS

In this project, for the first time, we have used computerised three-dimensional reconstruction techniques to visualise the developing human biliary system. Paraffin-embedded tissue from eight human embryos or fetuses between 5.5 and 16 weeks of gestation were serially sectioned, and their images were aligned, digitised, and used for three-dimensional reconstruction.

RESULTS AND CONCLUSIONS

Three-dimensional images of the extrahepatic and the intrahepatic biliary systems were obtained, and the following conclusions were drawn. (1) The intrahepatic biliary system, both at the porta hepatis and within the liver, developed from the ductal plate through a consistent pattern of remodelling. (2) Prior to the remodelling process, the ductal plate was of similar morphology irrespective of site and gestation. (3) The extrahepatic biliary system was in direct luminal continuity with the developing intrahepatic biliary system throughout gestation and did not show the presence of a "solid stage" in any of the embryos or fetuses studied.

Aldosterone to renin ratios in the evaluation of primary aldosteronism

Primary aldosteronism, though an uncommon cause of hypertension, causes significant morbidity, making it important to diagnose and treat this condition. Its evaluation requires complex and time consuming investigative procedures in order to confirm the diagnosis and to differentiate between the subtypes of aldosterone producing adenoma and idiopathic hyperaldosteronism. Often, the values of renin and aldosterone are equivocal, and the diagnosis of primary aldosteronism is in doubt. In this study, we examine the use of aldosterone to renin ratios in confirming the diagnosis of primary aldosteronism when the usual criteria of suppressed renin and elevated aldosterone are not met. We have found that an aldosterone to renin ratio of 50 has a 100% specificity and 92% sensitivity for detecting primary aldosteronism. Also, an aldosterone to renin ratio of > 2000 is suggestive of an aldosterone producing adenoma.

Thyroid stimulating hormone receptor antibody levels in Singaporean patients with autoimmune thyroid disease

Stimulating thyrotrophin receptor antibodies (TRAbs) have been identified as the antibodies responsible for the pathogenesis of Graves' disease (GD) while blocking TRAbs have been implicated as the cause of hypothyroidism in some patients with chronic lymphocytic thyroiditis (CLT). TRAb positivity in patients with other thyroid disorders such as silent thyroiditis, toxic multinodular goitre and subacute thyroiditis has been reported but the role of TRAb in these disorders is unclear. A study was carried out to determine the prevalence of TRAb positivity in Singaporean patients with a spectrum of thyroid diseases. TRAb levels were measured in 181 patients with GD, 54 patients with CLT (37 goitrous and 17 agoitrous), 16 patients with thyroid nodules, 11 patients with subacute thyroiditis, 1 patient with hyperthyroidism due to a human chorionic gonadotrophin (HCG)-secreting tumour, 2 patients with thyroid stimulating hormone-secreting tumours and 2 patients with amiodarone-induced dysthyroidism. Using a cut-off of 10.0 U/L, TRAb levels were found to be positive in 79.0% of GD patients, 9.2% of CLT patients (euthyroid and hypothyroid) and no patients with other thyroid disorders. TRAb was a more sensitive marker of GD than anti-thyroglobulin antibodies (53.2%) but not anti-microsomal (78.3%) antibodies. TRAb levels > 10.0 U/L appear to be highly specific for autoimmune thyroid disease.

Abnormal thyroid and adrenocortical function test results in intensive care patients

A prospective, cohort study of 75 consecutive patients requiring management in the medical intensive care unit (MICU) of the Singapore General Hospital was carried out over a five-month period to determine thyroid and adrenocortical profiles and evaluate their use in predicting patient outcome. Up to 88% of patients had at least one abnormal thyroid function and 77% had abnormal adrenocortical function test results. There were significantly lower triiodothyronine, thyroxine and free thyroxine, but not thyrotropin levels, and higher cortisol levels in non-survivors compared to survivors (all P < 0.01). Of the endocrine parameters, triiodothyronine and cortisol concentrations were independent predictors of outcome. The overall predictive accuracy of combining these two variables on admission into the MICU was 74%. The APACHE II (acute physiology and chronic health evaluation II) score alone predicted outcome with 71% accuracy, and in combination with triiodothyronine and cortisol levels improved accuracy to 84%. The use of dopamine alone predicted outcome with 74% accuracy, and in combination with triiodothyronine and cortisol levels, improved accuracy to 84%. Measurements of total triiodothyronine and cortisol concentrations on admission to the MICU, and consideration of the use of dopamine improve on the APACHE II score in outcome prediction.

Distortion in TGF beta 1 peptide immunolocalization in biliary atresia: comparison with the normal pattern in the developing human intrahepatic bile duct system

Biliary atresia is an important cause of neonatal obstructive jaundice in which there is inflammation, sclerosis and eventual obliteration of the bile duct system. Its onset may be antenatal, affecting the normal development of the biliary system. The intrahepatic biliary system is derived from the ductal plate, a sheath of cuboidal epithelium that appears at the hepatocyte-mesenchymal junction around the portal vein branches at 6 weeks gestation. This epithelial structure is moulded into a network of tubular bile ducts by the proliferating mesenchyme. Certain portions of the ductal plate are selected to become definitive bile ducts, while redundant biliary epithelium is deleted. The molecular dynamics controlling the intra-uterine development of the biliary system in humans are not yet clearly understood. Transforming growth factor-beta 1 is a cytokine that stimulates mesenchymal proliferation and inhibits epithelial growth, and has been shown to be important in organogenesis. In the present study, the pattern of TGF beta 1 peptide immunolocalization was investigated with the aid of computerized image analysis, in normal human bile duct development and in biliary atresia. TGF beta 1 peptide was detected within hepatocytes and ductal plate epithelium from 7 weeks gestation; increased TGF beta 1 immunoreactivity was present within the epithelium of developing bile ducts at 13 weeks gestation, and apical polarization of the cytokine was observed from 16 weeks gestation. In biliary atresia, the TGF beta 1 immunoreactivity pattern within the bile duct structures at the porta hepatis and within intrahepatic portal tracts resembled that of the primitive ductal plate, and there was no significant apical polarization. This may indicate a developmental arrest in the normal ductal plate remodelling process in biliary atresia, and suggests an underlying epithelial-mesenchymal interactive disorder.

Relations between plasma lipids and postheparin plasma lipases and VLDL and LDL subfraction patterns in normolipemic men and women

VLDL1, VLDL2, IDL, and LDL and its subfractions (LDL-I, LDL-II, and LDL-III) were quantified in 304 normolipemic subjects together with postheparin plasma lipase activities, waist/hip ratio, fasting insulin, and glucose. Concentrations of VLDL1 and VLDL2 rose as plasma triglycerides (TGs) increased across the normal range, but the association of plasma TGs with VLDL1 showed a steeper slope than that of VLDL2 (P < .001). Plasma TG level was the most important determination of LDL subfraction distribution. The least dense species, LDL-I, decreased as the level of this plasma lipid rose in the population. LDL-II in both men and women exhibited a positive association with plasma TG level in the range 0.5 to 1.3 mmol/L, increasing from about 100 to 200 mg/dL. In contrast, within this TG range the LDL-III concentration was low (approximately equal to 30 mg/dL) and changed little. As plasma TGs rose from 1.3 to 3.0 mmol/L there was a significant fall in LDL-II concentration in men (r = .45, P < .001) but not in women (r = .1, NS). Conversely, above the TG threshold of 1.3 mmol/L there was a steeper rise in LDL-III concentrations in men than in women (P < .001); 42% of the men had and LDL-III in the range associated with high risk of heart disease ( > 100 mg lipoprotein/dL plasma) compared with only 17% of the women. Other influences on the LDL subfraction profile were the activities of lipases and parameters indicative of the presence of insulin resistance. Men on average had twice the hepatic lipase activity of women. This enzyme was not strongly associated with variation in the LDL subfraction profile in men, but in women it was correlated with LDL-III (r = 39, P = .001) and remained a significant predictor in multivariate analysis. Increased waist/hip ratio, fasting insulin, and glucose were correlated negatively with LDL-I and positively with LDL-III, primarily, at least in the case of LDL-III, through raising plasma TGs. On the basis of these cross-sectional observations we postulate the following model for the generation of LDL-III. Subjects develop elevated levels of large TG-rich VLDL1 for a number of reasons, including failure of insulin action. The increase in the concentration of VLDL1 expands the plasma TG pool, and this, via the action of cholesteryl ester transfer protein (which facilitates neutral lipid exchange between lipoprotein particles), promotes the net transfer of TGs into LDL-II, the major LDL species.(ABSTRACT TRUNCATED AT 400 WORDS)

Management of hyperlipidaemia

Recent community-based studies have shown that hypercholesterolaemia is common in Singapore. High low-density lipoprotein (LDL) cholesterol, low high-density lipoprotein (HDL) cholesterol as well as hypertriglyceridaemia are associated with higher prevalence of cardiovascular disease. The aim of this article is to discuss the clinical management of adult patients with hyperlipidaemia. For practical purposes, the hyperlipidaemias can be divided into four patterns: 1) hypercholesterolaemia with normal triglyceride, 2) moderate hypertriglyceridaemia with normal cholesterol, 3) combined moderate hypercholesterolaemia and hypertriglyceridaemia, and 4) severe hypertriglyceridaemia with moderate hypercholesterolaemia. Each pattern can be attributed primarily to genetic conditions or secondarily to common diseases. It is important to attempt aetiopathogenetic diagnosis for each hyperlipidaemic patient as treatment of an underlying condition may sometimes reverse the hyperlipidaemia eg hypothyroidism and hypercholesterolaemia. In general, a low cholesterol and low fat (particularly saturated fat) diet is useful in patients with all four patterns of hyperlipidaemia. Patients with severe hypertriglyceridaemia and moderate hypercholesterolaemia may benefit from a further drastic reduction in fat intake. Pharmacological therapy is required for patients who do not achieve target lipid levels after diet modification. The choice of drug therapy is, to a large extent, dependent on the pattern of hyperlipidaemia. In some situations, combination drug therapy may be required. Caution is required in combining hypolipidaemic drugs as the side-effects of individual drugs may be potentiated when used in combination.