Personal view of SARS: confusing definition, confusing diagnoses.
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Diagnosis, Differential↗
Biomedical subjects
T F Leung
Publications and source records attributed to T F Leung.
Sociodemographic and atopic factors affecting breastfeeding intention in Chinese mothers.
OBJECTIVE: The factors accounting for the low 'ever breastfeeding' rate in Hong Kong remain unclear. The objective of this survey was to study the intention and planned duration of breastfeeding in Chinese women in Hong Kong, and to investigate the sociodemographic and atopic factors affecting the intention to breastfeed. METHODS: All Chinese mothers who were Hong Kong residents and who delivered their babies in a University teaching hospital were given a self administered and anonymous Chinese questionnaire within 1 day postpartum. The questionnaire included items on sociodemographic data, the presence of allergic diseases in the families, and the intention and planned duration of breastfeeding for their newborn babies. RESULTS: A total of 1374 eligible questionnaires were collected. About one-third of mothers were born outside Hong Kong and the majority (78%) of them were aged between 25 and 40 years. Logistic regression revealed that only socioeconomic factors, namely older maternal age (odds ratio (OR) 2.10, 95% confidence interval (CI) 1.14-3.89), parity (OR 3.08, 95% CI 1.02-9.27) and higher educational background (OR 2.87, 95% CI 1.92-4.27), significantly affected the intention to breastfeed. In addition, mothers born outside Hong Kong and those with first babies, had a longer intended duration of breastfeeding (P-values < 0.001 and 0.033, respectively). A family history of atopic disorders in parents or siblings did not influence the breastfeeding intention of these Chinese mothers. CONCLUSION: Several sociodemographic factors, rather than a history of atopic disorders, of Chinese mothers in Hong Kong affected their intention to breastfeed and the planned duration of breastfeeding.
Adult↗
Infection control for SARS in a tertiary neonatal centre.
The Severe Acute Respiratory Syndrome (SARS) is a newly discovered infectious disease caused by a novel coronavirus, which can readily spread in the healthcare setting. A recent community outbreak in Hong Kong infected a significant number of pregnant women who subsequently required emergency caesarean section for deteriorating maternal condition and respiratory failure. As no neonatal clinician has any experience in looking after these high risk infants, stringent infection control measures for prevention of cross infection between patients and staff are important to safeguard the wellbeing of the work force and to avoid nosocomial spread of SARS within the neonatal unit. This article describes the infection control and patient triage policy of the neonatal unit at the Prince of Wales Hospital, Hong Kong. We hope this information is useful in helping other units to formulate their own infection control plans according to their own unit configuration and clinical needs.
Cross Infection↗
Plasma TARC concentration may be a useful marker for asthmatic exacerbation in children.
Recent studies suggested the T-helper cells type-2 lymphocytes-specific thymus and activation-regulated chemokine (TARC) and monocyte-derived chemokine (MDC) are useful inflammatory markers for chronic asthma. However, their roles in assessing the severity of acute asthma are unknown. This study aims to evaluate the serial changes of plasma TARC and MDC concentrations in children with asthmatic exacerbation. All patients with acute asthma were treated with systemic corticosteroid for 5 days. The severity of asthmatic exacerbation was classified according to the Global Initiative for Asthma guidelines. Plasma TARC and MDC concentrations were measured by sandwich enzyme immunoassays. Sixteen children, with a median (interquartile range) age of 9.3 (7.2-10.6) yrs and asthmatic exacerbation, were recruited. Plasma TARC concentration showed inverse correlation with peak expiratory flow rate at presentation. The median plasma TARC concentration was highest during the acute attacks (46 pg x mL(-1)) as compared to those levels at 1 (31 pg x mL(-1)) and 5 weeks (32 pg x mL(-1)) following treatment. The median plasma MDC level similarly decreased from 698 pg x mL(-1) at baseline to 261 pg x mL(-1) 1 week later, but increased back to 574 pg x mL(-1) at 5 weeks. These results suggest that plasma T-helper cells type-2 lymphocytes-specific thymus and activation-regulated chemokine but not monocyte-derived chemokine concentration may be a useful inflammatory marker in assessing asthmatic exacerbation in children.
Acute Disease↗
Distribution in allele frequencies of predisposition-to-atopy genotypes in Chinese children.
Asthma is one of the most common chronic diseases in childhood; it is caused by a complex interaction between genetic factors and exposure to environmental allergens and irritants. Previous studies using the candidate gene approach showed that asthma was linked to a number of susceptibility genetic loci in Caucasian subjects. There are, however, only a few studies on asthma predisposition genes in the Chinese population. We studied the distribution of allele frequencies of I50V for the interleukin-4 receptor, two polymorphisms in intron 2 and exon 7 for the high-affinity IgE receptor (Fc epsilon RI-beta), R16G and E27Q for the beta(2)-adrenoceptor,and R275Q (824G/A) for CC chemokine receptor 3 in Chinese children.Seventy-six patients, with a mean age of 10.6 years, and 70 age- and sex-matched controls, were studied. Significantly more subjects in the asthma group had specific IgE antibodies against environmental allergens (P < 0.0001; odds ratio, 9.82). Genotyping of the six genetic markers showed that none of the six polymorphisms was associated with asthma in this cohort. The allele frequencies of I50V, R16G, and E27Q in our population were similar to those published for Asian subjects but not Caucasians. The R275Q substitution was a rare finding in our study and in the published reports. Our results demonstrate ethnic differences in polymorphisms of atopy candidate genes. Additional studies involving larger samples are required to investigate the association between asthma or atopy and the genotypes studied to date in Chinese children.
Asthma↗
Haematopoietic stem cell transplantation for thalassaemia major in Hong Kong: prognostic factors and outcome.
From August 1992 to August 1999, 44 patients received allogeneic haematopoietic stem cell transplantation in a single institution. The donors were HLA-identical siblings except for one who was a phenotypically matched father. Thirty-eight patients received bone marrow stem cells and the others received peripheral blood stem cells or umbilical cord blood (UCB). The mean age at transplant was 10.7+/-5.1 years, ranging from 1.8 to 21 years. Patients received busulphan (16 mg/kg) and cyclophosphamide (150 to 200 mg/kg) as conditioning, and antithymocyte globulin was given to 42 patients to prevent graft rejection. All had engraftment except a patient who received a UCB transplant. Four patients died from early treatment-related mortality, and one died from interstitial pneumonitis 3 months after transplant. Two patients developed secondary graft rejection and both received a second transplant. Thirty-eight patients survived and all except one were transfusion independent. The 5-year overall and event-free survival rates were 86% and 82%, respectively. By multivariate stepwise Cox proportional hazard analyses, severe veno-occlusive disease (VOD) of liver and Pesaro class 3 features were the significant factors associated with survival. Patients aged more than 11 years were more inclined to develop VOD. In conclusion, haematopoietic stem cell transplantation should be performed early if an HLA identical sibling is available.
Adolescent↗
Issues regarding nonattendance at a paediatric dermatology centre.
Nonattendance in paediatric dermatology clinics is a significant problem. We reviewed the charts of all 400 new referrals to the Prince of Wales Hospital (PWH) paediatric dermatology clinic in the year 2000. Sixty-six patients (17%) did not attend. The mean age +/- SD of attenders (7.5 +/- 5.1 years) and nonattenders (7.7 +/- 4.5 years) did not differ significantly. Forty-eight per cent of the referrals were females, 50% of the attenders were females and 67% of the nonattenders were male. Males were 2.1-fold more likely not to attend clinic relative to females (95% confidence interval 1.14-3.71, P = 0.010). Nonattendance was significantly higher among referrals from the PWH emergency department, compared with referrals by private practitioners (P = 0.05) and referrals by other clinics in the PWH. Data in this retrospective study confirm that there is a gender disparity in hospital nonattendance. More dermatological referrals but more nonattendance were associated with the male patients.
Ambulatory Care↗
Montelukast in the treatment of children with moderate-to-severe atopic dermatitis: a pilot study.
The primary action of leukotrienes includes contraction of human airway muscle, chemotaxis, and increased vascular permeability, with secondary effects of inhibiting allergen-induced early and late responses. Although there is limited available information and research regarding leukotrienes in atopic dermatitis (AD), there is evidence to support their role in the pathogenesis of the disease. We conducted a pilot study to test the efficacy of montelukast, a cysteinyl-leukotriene-1 receptor antagonist, in 15 patients (6-16 years of age) with moderate-to-severe AD, using a randomized double-blind placebo-controlled crossover study. These patients had chronic moderate-to-severe AD, despite being on conventional therapy. They were randomized either to placebo for 4 weeks and then the study drug for 4 weeks, or vice versa. There was a 2-week run-in period for all participants before commencement of the study, and a 2-week washout before crossover. At enrollment and on each follow-up visit, every patient was assessed by a single observer and objectively scored for disease extent and severity. A subjective score was given for the impact of eczema on daily living. There was statistical improvement in patents on active treatment compared with placebo in the severity of AD (p < 0.05). Our findings suggest that leukotriene receptor antagonist as an adjunct treatment has an anti-inflammatory effect on moderate-to-severe AD. A larger trial is needed to ascertain its efficacy fully.
Acetates↗
A polymorphism in the coding region of interleukin-13 gene is associated with atopy but not asthma in Chinese children.
BACKGROUND: Interleukin (IL)-13 is an important cytokine secreted from type 2 helper T lymphocytes. It is essential for modulating IgE synthesis by human B cells. Previous studies showed that polymorphisms in the IL-13 gene were associated with serum total IgE or allergic asthma. The relationship of this marker with sensitization to individual aeroallergens has not been evaluated. OBJECTIVE: We tested whether a polymorphism in the coding region of the IL-13 gene is associated with asthma and atopy in asthmatic children in Hong Kong. METHODS: We used restriction fragment length polymorphism to detect R130Q genotype in Chinese children with asthma and control subjects. Serum total IgE was measured by microparticle immunoassay and specific IgE to common aeroallergens was measured using fluorescent enzyme immunoassay. Pulmonary function studies were performed using spirometry. RESULTS: One hundred and fifty-seven patients and 54 control children were recruited. Their mean serum total IgE concentrations were 994 kIU/L and 473 kIU/L, respectively (P < 0.0001). Atopy as defined by > or = 1 positive RAST was found in 141 patients and 32 control children. The GlnGln form of the R130Q polymorphism in the IL-13 gene was associated with serum total IgE (P = 0.005) as well as specific IgE to Der p 1 (P = 0.021), mixed cockroaches (P = 0.03) and dog (P = 0.003) but not with physician-diagnosed asthma (P = 0.621). In addition, the R130Q polymorphism did not correlate with subjective or objective indicators of asthma severity in our patients. CONCLUSION: Our results suggest that the R130Q polymorphism of the IL-13 gene is associated with elevated serum total and allergen-specific IgE but not asthma in Chinese children.
Adolescent↗
Severe chronic neutropenia in Chinese children in Hong Kong.
OBJECTIVE: Severe chronic neutropenia (SCN) is a rare and heterogeneous disorder in children. The epidemiology, clinical features and outcomes of SCN in Chinese children were reviewed. METHODOLOGY: A retrospective analysis of case records was undertaken for 18 children with SCN managed during a 12-year period in a university teaching hospital in Hong Kong. RESULTS: The median (range) age of the patients at initial presentation was 6.5 months (4 days-19 months). The initial and lowest median absolute neutrophil counts (ANC) were 0.29 x 109 /L and 0.06 x 109 /L, respectively. Patients with congenital SCN had significantly fewer neutrophils in peripheral blood at diagnosis. Only five subjects received granulocyte colony-stimulating factor (G-CSF) treatment. All children were free from serious infection on follow up for 51 months. Only one child suffered from long-term infection-related morbidity. One patient with chronic neutropenia was subsequently shown to have common variable immunodeficiency. CONCLUSIONS: Most children with SCN in our series had favourable clinical outcomes. Our results support the recommendation that G-CSF should be used only in those with recurrent or severe infections.
China↗
Thyrotoxic periodic paralysis in a 14-year-old boy.
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Adolescent↗
Sex differences in the growth of diabetic children.
To investigate the effect of diabetes on the growth of children and to detect possible impairment of their final height, 58 Chinese subjects (22 boys; 36 girls) with childhood diabetes were studied longitudinally from diagnosis. Mean onset age at presentation was 8. 70 years. All patients were measured and weighed at diagnosis and every 3-4 months during the follow up period. Their height and weight measurements were converted to standard deviation scores (S.D. S.) using normal height and weight-for-height reference standards for Chinese children established in Hong Kong. The mean height S.D.S. for boys and girls at diagnosis were +0.76 and -0.07 (P=0.015). The mean final height S.D.S. for boys and girls were +0.14 and -0.57. The final heights of girls were significantly shorter than their target heights. At attainment of final height for diabetic girls, their mean weight-for-height S.D.S. was +0.76 indicating that they tended to become overweight. This study demonstrates the sex differences in the growth of diabetic children. Diabetic boys were tall for age at presentation but they achieved average final heights while diabetic girls attained below average adult stature and they tended to become obese.
Adult↗
Incidence, risk factors and outcome of varicella-zoster virus infection in children after haematopoietic stem cell transplantation.
We report a retrospective analysis of VZV infection after haematopoietic stem cell transplantation (HSCT) in children. Thirty-three (30%) of the total 109 children who were transplanted during a 7 year period developed post-transplant VZV infection. Twenty-four of these 33 (73%) children had VZV infection within 1 year following HSCT. The cumulative incidences of post-transplant VZV infection at 1 and 5 years were 26% and 45%, respectively. The positive and negative predictive values of pretransplant VZV serology in recipients on the development of HZ following HSCT were 39% and 88%, respectively. Pretransplant VZV seropositivity in recipients was the only risk factor for post-transplant herpes zoster (HZ) infection on multivariate analysis. All patients responded to acyclovir. The median duration of VZV infection was 5 days. Three (11%) and one (3%) children with HZ developed visceral dissemination and post-herpetic neuralgia, respectively. No mortality was directly attributed to VZV infection. VZV infection remains a major cause of morbidity in children after HSCT. Further studies are warranted to evaluate the potential use of VZV vaccine in these children. Bone Marrow Transplantation (2000) 25, 167-172.
Acyclovir↗
Mercury intoxication presenting with tics.
A 5 year old Chinese boy presented with recurrent oral ulceration followed by motor and vocal tics. The Chinese herbal spray he used for his mouth ulcers was found to have a high mercury content. His blood mercury concentration was raised. Isolated tics as the sole presentation of mercury intoxication has not previously been reported.
Child, Preschool↗
Allergen sensitisation in asthmatic children: consecutive case series.
OBJECTIVE: To investigate the pattern of sensitisation to aero-allergens and food allergens among asthmatic children in Hong Kong, and to investigate any correlation between atopy and the severity of asthma. DESIGN: Consecutive case series. SETTING: Paediatric out-patient clinic of a university teaching hospital, Hong Kong. PARTICIPANTS: Two hundred and four consecutive children with physician-diagnosed asthma who attended from January 1999 through June 2000. MAIN OUTCOME MEASURES: Demographic data, questionnaire assessment of asthma control, spirometric evaluation, response to skin prick testing, eosinophil count, and total serum immunoglobulin E concentration. RESULTS: The median patient age was 8.2 years (range, 5.7-11.3 years), and the median 1-second forced expiratory volume was 95% of the predicted value. The median absolute eosinophil count in the peripheral blood was 0.48 x 10(9) /L and the ratio of total serum immunoglobulin E to the age-adjusted upper limit of the normal range was 2.7. Atopy, as defined by at least one positive response to skin prick testing, was found in 170 (83.3%) of the 204 patients. House dust mites were the most commonly sensitised aero-allergen (n=167; 81.9%). Sensitisation to food allergens was found in 47 (23.0%) of the patients. The self-reported frequency of asthmatic attacks was associated with a positive response to skin prick testing with animal allergens (P for trend = 0.001), whereas spirometric indices correlated with the degree of atopy and the presence of in vivo cockroach-specific immunoglobulin E. CONCLUSION: Sensitisation to indoor aero-allergens, as determined by skin prick testing, is prevalent among Chinese children with mild-to-moderate asthma, whereas sensitisation to food allergens is not. The severity of asthma is correlated with skin prick test responses to pet and cockroach allergens.
Air Pollutants↗
Granulocyte colony-stimulating factor-mobilized peripheral blood stem cells in beta-thalassemia patients: kinetics of mobilization and composition of apheresis product.
beta-Thalassemias are often associated with bone marrow expansion and immunomodulation in terms of lymphocyte subsets and cytokine levels in the peripheral blood. The mobilization of peripheral blood stem cells (PBSC) by cytokines in such a background has not been reported. If achieved, the apheresis product could be used as a stem cell back-up for beta-thalassemia patients prior to bone marrow transplant. PBSC collection may also become a means for providing stem and progenitor cells for gene manipulation and therapy of this disorder. The aim of the study was to assess the administration of G-CSF in mobilizing stem and progenitor cells in these patients and to compare the kinetics of CD34+ cells and lymphocyte subsets with those of healthy PBSC donors. Results showed that the CD34+ cells were effectively mobilized by G-CSF (10-16 micrograms/day per kg) in 20 thalassemia patients and 11 healthy donors. Although no significant difference was observed in levels of daily stem cell counts between the two groups of subjects, a 1 day delay in achieving peak levels of CD34+ cells was observed in the majority of thalassemia patients. The peak increase of CD34+ cells was 21.5 +/- 6.1-fold and 30.8 +/- 7.6-fold of the basal steady-state levels in thalassemia patients and healthy donors, respectively. Similar to the situation of healthy donors, G-CSF stimulated essentially the CD34+ cells and the myeloid lineage (granulocytes, monocytes) in thalassemia patients and had a slight effect on lymphocyte subsets (T-helper, T-suppressor, NK, and B cells) and activation (CD25, HLA-DR, and CD45RO). Compositions of the apheresis products, including CD34+CD38-, CD34+CD33+ and CD34+HLA-DR- cells, were similar in the two groups of subjects. Correlation studies showed that the level of CD34+ cells in the PB is a good indicator of that in the apheresis product (r = 0.88, p < 0.001). The study has demonstrated that under close monitoring of CD34+ cell levels in PB, the mobilization by G-CSF and collection of PBSC in beta-thalassemia patients are feasible.
Adolescent↗
Aplastic anaemia in association with Kearns-Sayre syndrome.
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Anemia, Aplastic↗
Busulphan level and early mortality in thalassaemia patients after BMT.
The aim of the study was to correlate busulphan (BU) levels of thalassaemia patients with outcome of allogeneic transplant. BU levels were measured by gas chromatography mass fragmentography. All patients received a standardised dose of BU 16 mg/kg, and cyclophosphamide 150 or 200 mg/kg. For area-under-the-curve analysis (AUC), blood samples were obtained at 0, 1, 2, 3, 4 and 6 h after the first and fifth dose for all patients, and additional levels were measured after ninth and/or 13th dose in most patients. Outcome parameters examined included veno-occlusive disease of liver (VOD), idiopathic interstitial pneumonitis, chimerism, and day 90 survival. Twenty consecutive thalassaemia patients who underwent haematopoietic stem cell transplantation were studied. The median age at transplant was 11.2 years (range 3-21 years). Mean BU AUC levels were correlated with age at transplant (r = 0.58, P = 0.007). Nine patients developed VOD and six had mixed chimerism, but these did not correlate with mean BU AUC level. Four patients died before day 50 from VOD and interstitial pneumonitis. Patients with BU AUC levels greater than the median (908 micromol x min/l) had significantly lower probability of survival at day 90 (60%), whereas patients with BU AUC level less than the median all survived beyond day 90. No patient had graft rejection. In conclusion, a high BU AUC level was associated with a higher treatment-related mortality in thalassaemia patients after transplant.
Adolescent↗