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Biomedical subjects

E A S Nelson

Publications and source records attributed to E A S Nelson.

At least 19 recordsLinked to original sources
PubMed2006

Demographic and lifestyle factors associated with dioxin-like activity (CALUX-TEQ) in human breast milk in Hong Kong.

Maternal exposure to dioxins and related compounds before conception may affect the health of the fetus. To identify factors affecting dioxin body load in Hong Kong, in 2002, total dioxin-like activity was estimated in 250 individual milk samples at 2-6 weeks postpartum, from a representative group of primiparous mothers, aged 18-42 years (mean 29 +/- 5 years), by a chemically activated luciferase expression (CALUX) bioassay. Associations between the CALUX-TEQ and 20 socio-demographic and dietary variables were examined separately in mothers younger than 30 years (n = 114) and 30 years or older (n = 119), by multiple linear regression analysis. CALUX-TEQ (mean 14.5 +/- 5.8 pg/g fat) significantly increased by 0.4-0.5 pg/g fat for every year of the mother's age. Mothers born in Guangdong province of China had a significantly higher CALUX-TEQ. Higher seafood consumption (older mothers; p = 0.07) and having a female baby (younger mothers; p = 0.002) were associated with a higher maternal CALUX-TEQ level. Age was the strongest factor affecting human dioxin levels in Hong Kong. Birthplace and residence are important indicators of variations in exposure to environmental pollution in the Asia Pacific region. Temporal trends in body loads of dioxins remain to be established and continuous monitoring of dioxins in humans and foods is necessary as a precautionary approach to guide environmental control measures and prevent exposure to infants.

Adolescent↗
PubMed2006

Meal glycaemic load of normal-weight and overweight Hong Kong children.

OBJECTIVE: To describe the pattern of meal glycaemic load of children in Hong Kong and to determine whether the meal glycaemic load is associated with childhood overweight. METHOD: Dietary records (3-day) of 316 Hong Kong children aged 6-7 years were collected. Glycaemic load was calculated from the estimated weight (WT), carbohydrate content (%CHO) and glycaemic index (GI) of each food taken using the equation: (% CHO x GI x WT/100). The meal glycaemic load was then the sum of the glycaemic loads of all food taken in each meal. Logistic regression analyses were used to compare the average meal glycaemic load (of breakfast, lunch and dinner) and other dietary parameters between overweight children and normal-weight children. RESULTS: Breakfast, lunch, dinner and snacks provided, respectively, 17, 29, 29 and 25% of the total glycaemic load in a day. White rice (excluding congee (rice porridge) and glutinous rice) contributed almost half of the total glycaemic load. Adjusted logistic regression showed that the meal glycaemic load was not significantly associated with childhood overweight after adjusting for parental obesity, birth weight, sleeping duration, mean energy intake and paternal smoking. CONCLUSION: Meal glycaemic load calculated from current diet was not an independent factor associated with childhood overweight in children aged 6-7 years. Our data suggested that modifying the type of rice/staple consumed and choosing low-GI snacks could have a major influence on the total meal glycaemic load of young Hong Kong children.

Case-Control Studies↗
PubMed2005

Ultrastructural assessment of Plasmodium falciparum in age-fractionated thalassaemic erythrocytes.

Culture of Plasmodium falciparum in age-fractionated thalassaemic red blood cells (RBC) has shown evidence of parasite damage on light microscopy in older cells during the third culture cycle (96-144 h). In this report, parasites growing in thalassaemic trait and normal RBC were examined ultrastructurally from 96 to 144 h. All parasite stages in old thalassaemic RBC showed evidence of damage worsening with culture duration. There were cytoplasmic alterations with ribosomal damage, and parasite cytoplasm became increasingly loose and grainy, with multiple fissures. Discontinuity of the nuclear membrane with an abnormal nucleolus was seen at l20 h. Cytosomes remained normal, but damage to the food vacuole and shrunken disintegrating parasites were observed at 144 h. These changes are compatible with cellular degeneration and developmental retardation and would account for the schizont maturation arrest and reduced reinvasion rates previously reported. Increased free radicals associated with thalassaemic erythrocytes would explain these changes, further supporting the role for oxidant stress in the protective mechanism.

Animals↗
PubMed2005

Bone mineral density and calcium metabolism of Hong Kong Chinese postpartum women--a 1-y longitudinal study.

OBJECTIVE: This paper reports longitudinal changes in bone mineral density (BMD), calcium homeostasis and dietary calcium intake in a group of Hong Kong breastfeeding women during the first year postpartum. DESIGN AND SUBJECTS: Nine mothers who breastfed exclusively or almost exclusively for at least 3 months and 14 formula feeding mothers aged 20-40 y were interviewed after delivery, 2 and 6 weeks, 3, 6 and 12 months postpartum. BMD at L2-L4 lumbar spine (LS), trochanter (Tro) and femoral neck (FN), serum intact parathyroid hormone (iPTH), serum bone-specific alkaline phosphatase (b-ALP), urinary deoxypyridinoline (Dpd), serum and urinary calcium (Ca) and phosphorus (P) and dietary intake of macronutrients were assessed. RESULTS: Compared to the formula feeding group, BMD assessed at LS, Tro and FN decreased significantly in the breastfeeding group over the first 6 months, with rebound to approximate baseline values at 12 months for the latter two sites. Serum iPTH increased in both groups, whereas serum b-ALP was consistently higher in the breastfeeders. Urinary Ca and P excretion decreased early postpartum in both groups, but the breastfeeders had higher excretion at 3 and 6 months. Breastfeeding mothers consumed significantly more Ca than the formula feeding mothers in the early postpartum. CONCLUSIONS: Increased calcium requirement during early lactation is affected through mobilisation of bone and renal calcium conservation. Bone mineral loss during lactation is temporary. Further studies are warranted to investigate the effects of diet and other hormonal factors on the calcium homeostasis during lactation.

Adult↗
PubMed2005

A case-control study of SARS versus community acquired pneumonia.

The clinical, laboratory, and radiological features at presentation of 16 children (<12 years) with severe acute respiratory syndrome (SARS) and pneumonia were compared with 32 age matched patients with community acquired pneumonia for determination of predictive factors that could allow early differentiation of the two conditions. A definitive contact history was the most important predictor for SARS. Raised serum lactate dehydrogenase concentration in the presence of low neutrophil count and serum creatine phosphokinase level at presentation also indicated an increased likelihood of SARS-coronavirus infection in young children.

Biomarkers↗
PubMed2005

International Child Care Practices study: breastfeeding and pacifier use.

Although the Baby-Friendly Hospital Initiative advises that no pacifiers be given to breastfeeding infants, both breastfeeding and pacifier use may protect against sudden infant death syndrome. The International Child Care Practice Study data set on child care practices associated with sudden infant death syndrome risk from 21 centers in 17 countries was used to describe infant-feeding practices and pacifier use and assess factors associated with breastfeeding. At approximately 3 months of age, rates of breastfeeding only (4%-80%) and pacifier use(12.5%-71%) varied between centers. Pacifier use was negatively associated with breastfeeding, and a dose-response effect was noted. Other negative (multiple birth, smoking by mother) and positive (intention to breastfeed, bed sharing, mothers' education) associations with breastfeeding only were identified. Although causality should not be inferred, these associations are consistent with previous studies. Advice on pacifiers should include potential benefits as well as risks.

Breast Feeding↗
PubMed2005

Review of children hospitalised for ingestion and poisoning at a tertiary centre.

INTRODUCTION: The main aim of this study is to determine the pattern of referrals of poisoning to a tertiary university hospital. The information will be used for poison prevention programme planning, and for educating and awareness promoting to the public. MATERIALS AND METHODS: All patients (under 21 years of age) admitted to the paediatric wards between January 1997 and December 2002 with a discharge diagnosis indicating unintentional (UP) or intentional poisoning (IP) were identified through the computerised discharge information. RESULTS: Sixty males and 98 females accounted for 161 admissions over the 6-year period. Their mean (standard deviation, SD) age was 8.2 (6.2) years. Sixty per cent of admissions involved UP. Females accounted for 47% of the UP but 86% of the IP [odds ratio of females for IP, 7.05; 95% confidence interval (CI) 2.95 to 17.28]. When compared with UP, IP patients were significantly older [mean (SD): 14.9 (1.7) versus 3.6 (3.3) years]. In 70% of the admissions, the patients ingested a single substance. Tablets and pills, especially in the IP adolescents, were more commonly ingested than syrups. The spectrum of substances ingested was vast but paracetamol, cough or cold medicines, and common adult household medications and agents accounted for the majority of medications ingested. The substances ingested were obtained at home in 81 cases (50%) and as over-the-counter medication in 33 (20%). The majority (92%) of patients presented within 24 hours of ingestion. On admission, 63% of UP and 45% of the IP were asymptomatic. No active treatment was required in 65% of patients. In IP, nearly 30% of IP who ingested paracetamol had toxic levels and received N-acteyl cysteine. A history of previous poisoning was more common and subsequent follow-up was offered to 74%. CONCLUSION: Young boys were more at risk of unintentional ingestion whereas adolescent girls were more likely to ingest medications as a gesture of suicide. Paracetamol is a frequently ingested medicinal for which an antidote is available.

Acetaminophen↗
PubMed2004

Infection control for SARS in a tertiary paediatric centre in Hong Kong.

Severe acute respiratory syndrome (SARS) is an emerging infectious disease. After the appearance of an index patient in Hong Kong in February 2003, SARS outbreaks occurred rapidly in hospitals and spread to the community. The aim of this retrospective study is to evaluate the effectiveness of a triage policy and risk-stratified infection control measures in preventing nosocomial SARS infection among paediatric healthcare workers (HCWs) at the Prince of Wales Hospital, a general hospital to which children with SARS are referred in Hong Kong. The acute paediatric wards were stratified into three areas: (1) ultra high-risk area, (2) high-risk area and (3) moderate-risk area according to different risk levels of nosocomial SARS transmission. The implementation of different levels of infection control precautions was guided by this risk stratification strategy. Between 13 March and 23 June, 38 patients with probable and suspected SARS, 90 patients with non-SARS pneumonia, and 510 patients without pneumonia were admitted into our unit. All probable SARS cases were isolated in negative-pressure rooms. Twenty-six HCWs worked in the ultra high-risk area caring for SARS patients and 88 HCWs managed non-SARS patients in other ward areas. None of the HCWs developed clinical features suggestive of SARS. In addition, there was no nosocomial spread of SARS-associated coronavirus to other patients or visitors during this period. In conclusion, stringent infection control precautions, appropriate triage and prompt isolation of potential SARS patients may have contributed to a lack of nosocomial spread and HCW acquisition of SARS in our unit.

Cross Infection↗
PubMed2004

Rolling over in infants: age, ethnicity, and cultural differences.

A preliminary cross-sectional study of 72 Hong Kong Chinese infants suggested that these infants learn to roll from supine-to-prone before rolling from prone-to-supine i.e. the opposite to teaching in most western texts. Three-hundred and sixty mothers were recruited postpartum and asked to record, on a chart, information related to the developmental milestone of rolling over for their infants (49% male) during the next 9 months. Telephone reminders were given at 4 and 8 months and, by the end of the study, information had been obtained from 240 mothers (67% of original sample, 51% male infants). Mean ages of rolling over were 5.1 months (SD1.5) for supine-to-prone and 5.7 months (SD1.3) for prone-to-supine. Age of rolling over from supine-to-prone was not influenced by usual sleep position, infant's sex, mother's intention to breastfeed infant, number of siblings, marital status, main daytime caregiver, or feeding method over 9 months. Hong Kong Chinese infants roll from supine-to-prone before they roll from prone-to-supine.

Adult↗
PubMed2004

Surveillance of childhood diarrhoeal disease in Hong Kong, using standardized hospital discharge data.

Discharge information for all Hong Kong government hospitals, which is routinely collected through the Clinical Management System (CMS), was used to assess the relative importance of all causes of diarrhoeal illness and to address the issue of under-diagnosis of rotavirus by linking discharge diagnostic codes with actual laboratory results for one hospital. Of all children less than 5 years of age hospitalized in Hong Kong in the 2-year period July 1997 to June 1999, 12,257 (11%) were discharged with a primary diarrhoea diagnosis (74% coded as non-specified, 10.4% as rotavirus, 11% as Salmonella and 5% as other viral or bacterial). Linked laboratory and discharge data for one hospital demonstrated that 15% (n = 1522) of all admissions had a primary diarrhoea diagnosis and that 40% of these had a specimen sent for rotavirus testing, of which 37% were positive. However, 46% (67/145) of children with a diagnosis of rotavirus infection had no virology result, and 69% (172/248) of positive rotavirus results were in children with no diagnosis indicating rotavirus infection. Modification of the CMS to routinely combine existing computerized laboratory data with the CMS discharge diagnoses and to develop mechanisms to enhance reliability of discharge diagnosis coding could produce a powerful resource for disease surveillance, auditing and for monitoring the impact of future vaccination and other prevention programmes.

Child↗
PubMed2004

Hepatic steatosis in obese Chinese children.

OBJECTIVES THE AIMS OF OUR STUDY WERE: (1) to determine the prevalence of asymptomatic hepatic steatosis and presumed nonalcoholic steatohepatitis, in our local population of obese Chinese children referred for medical assessment; and (2) to assess the correlation between severity of ultrasonographic hepatic steatosis and degree of obesity, insulin resistance and serum biochemical abnormalities. DESIGN: Cross-sectional study. METHODS: In total, 84 obese children, 25 girls and 59 boys with median age and body mass index (BMI) of 12.0 years (interquartile range (IR): 9.5-14.0) and 30.3 kg/m(2) (IR: 27.1-33.4), respectively, referred for medical assessment were studied. All subjects underwent physical examination, anthropometric and dual energy X-ray absorptiometry (DEXA) scan measurements and real-time ultrasonographic (US) examination of the liver. Fasting blood samples were collected for the measurement of liver function, hepatitis status, levels of serum glucose and insulin and lipid profile. Degree of fatty infiltration of the liver was graded according to ultrasonic appearance of liver echotexture, liver-diaphragm differentiation in echo amplitude, hepatic echo penetration and clarity of hepatic blood vessels. RESULTS: All recruited subjects had no history of alcohol abuse and tests for Hepatitis B or C virus were negative. Thorough examination showed all of them to be in general good health without signs of chronic liver disease. Hepatic steatosis identified by defined ultrasonic appearances was diagnosed in 65 subjects (77%); 17 girls and 48 boys. The severity of fatty liver was positively related to anthropometric measurements including BMI, waist and hip circumference, subscapular skinfold thickness; insulin resistance markers [QUICKI and homeostasis model assessment (HOMA)], and hypertriglyceridaemia. Multvariate ordinal regression analysis showed that BMI and raised alanine aminotransferase (ALT) were positively associated with fatty liver. Combination of hepatic steatosis with raised ALT (presumptive NASH) was found in 19 subjects (24%). This group of patients had significantly higher waist hip ratio and conicity index compared to those with isolated hepatic steatosis. Boys with presumed NASH were also found to have significantly higher insulin resistance. CONCLUSION: Nonalcoholic fatty liver disease (NAFLD) was common among our cohort of obese children referred for medical assessment. The prevalence of simple steatosis and presumed NASH was 77 and 24%, respectively. The severity of US steatosis was positively correlated with BMI, raised ALT, insulin resistance and hypertryglyceridaemia. Ultrasonography being noninvasive and readily available could be used for the monitoring of the progression of hepatic steatosis. Further longitudinal studies are required to determine the natural disease progression and the role of insulin resistance and other factors in the pathophysiology of NAFLD.

Adolescent↗
PubMed2004

Breast milk substitutes in Hong Kong.

OBJECTIVE: In 1981 the World Health Assembly (WHA) adopted the International Code of Marketing of Breast Milk Substitutes (the Code) to support breastfeeding. Despite improving trends, Hong Kong has low rates of breastfeeding compared to other developed countries. METHODS: We surveyed companies marketing breast milk substitutes in Hong Kong to determine self-reported adherence to the Code. Companies were informed that individual responses would not be published and seven of nine companies responded to the questionnaire. RESULTS: The majority of respondents promoted infant and follow-on formula in hospitals and provided free supplies of infant formula to hospitals. Follow-on formula and weaning foods were promoted in shops and to the general public and free samples were given to mothers reflecting a belief that, despite WHA resolutions, follow-on formula is not a breast milk substitute. CONCLUSIONS: Transnational companies should follow the Code and subsequent WHA resolutions equally in all countries.

Hong Kong↗
PubMed2004

Towards an integrated approach to lung health in adolescents in developing countries.

The World Health Organization strategies, Integrated Management of Childhood Illness and Practical Approach to Lung health provide assessment and management guidelines for health workers in developing countries. We reviewed issues important to lung health in adolescents to highlight whether differences in factors such as adolescent behaviour have consequences for the development of case management guidelines, to form a bridge between guidelines for younger children and for adults and to make suggestions for further study. Pneumonia, asthma and tuberculosis are the leading lung health problems in adolescents. As countries industrialise, the importance of asthma mortality and morbidity increases as that of pneumonia and pulmonary tuberculosis decreases. Guidelines for managing pneumonia and asthma in children and adults in developing and developed countries should be adaptable for use in adolescents in developing countries, although more information is needed on predictors of severity such as respiratory rate cut-offs, level of fever, hypotension, malnutrition and level of consciousness. The effectiveness of low-cost treatment for asthma should be explored further. HIV and the global resurgence of tuberculosis pose significant challenges for improving adolescent lung health, and prevention of smoking initiation during adolescence is a priority goal of any integrated approach to improving lung health.

Adolescent↗
PubMed2004

First report from the Asian Rotavirus Surveillance Network.

Rotavirus remains the most common cause of severe, dehydrating diarrhea among children worldwide. Several rotavirus vaccines are under development. Decisions about new vaccine introduction will require reliable data on disease impact. The Asian Rotavirus Surveillance Network, begun in 2000 to facilitate collection of these data, is a regional collaboration of 36 hospitals in nine countries or areas that conduct surveillance for rotavirus hospitalizations using a uniform World Health Organization protocol. We summarize the Network's organization and experience from August 2001 through July 2002. During this period, 45% of acute diarrheal hospitalizations among children 0-5 years were attributable to rotavirus, higher than previous estimates. Rotavirus was detected in all sites year-round. This network is a novel, regional approach to surveillance for vaccine-preventable diseases. Such a network should provide increased visibility and advocacy, enable more efficient data collection, facilitate training, and serve as the paradigm for rotavirus surveillance activities in other regions.

Asia↗
PubMed2003

Risk factors for childhood overweight in 6- to 7-y-old Hong Kong children.

OBJECTIVE: To identify risk factors for overweight in Hong Kong children aged 6-7 y. DESIGN: Case-control study. SETTING: Student Health Service Centres, Hong Kong. SUBJECTS: A total of 343 Hong Kong Chinese children aged 6-7 y old categorised into three groups, an overweight group (> or =92 nd centile for BMI), a normal middle-weight group (45th-55th centile for BMI) and a normal low-weight group (< or =8th centile for BMI). MEASUREMENTS: Subjects and their parents/caregivers were interviewed at home. Data on lifestyle habits, dietary habits, family structure and demographic background were collected by questionnaire. A 3-day dietary record was administrated by the parents/caregivers to assess dietary intake of the children. RESULTS: Logistic regression analyses (overweight group compared with middle-weight plus low-weight groups) showed that childhood overweight was significantly associated with parental obesity (BMI > or =25 kg/m(2), Asian reference) (paternal: OR=2.66, 95% CI=1.51-4.70; maternal: 5.07, 2.62-9.79) but not parental overweight (BMI=23-25 kg/m(2)). After adjustment for parental obesity, the odds ratio for childhood overweight was increased by birth weight (<3.0 kg as reference, 3.0-3.5 kg: 2.13, 1.18-3.84; > or =3.5 kg: 4.89, 2.49-9.60) and decreased by sleeping duration (<9 h/day as reference, 9-11 h/day: 0.54, 0.30-0.97; > or =11 h/day: 0.31, 0.11-0.87). Childhood overweight was also significantly associated with higher energy consumption (2.62, 1.20-5.74) and having a father who was a current smoker (2.08, 1.25-3.46). CONCLUSIONS: Although healthy diet and regular exercise will remain the cornerstones of obesity management in children, our data support the view that education about maintaining a healthy weight could be introduced much earlier in those families with high-risk children, as indicated by high parental BMI or high birth weight. The utility and practicality of such an approach should be carefully evaluated before becoming part of any public health policy. Further study of the role of short sleeping duration and parental smoking on childhood obesity development is warranted.

Birth Weight↗