L-edge spectroscopy of dilute, radiation-sensitive systems using a transition-edge-sensor array.

We present X-ray absorption spectroscopy and resonant inelastic X-ray scattering (RIXS) measurements on the iron L-edge of 0.5 mM aqueous ferricyanide. These measurements demonstrate the ability of high-throughput transition-edge-sensor (TES) spectrometers to access the rich soft X-ray (100-2000 eV) spectroscopy regime for dilute and radiation-sensitive samples. Our low-concentration data are in agreement with high-concentration measurements recorded by grating spectrometers. These results show that soft-X-ray RIXS spectroscopy acquired by high-throughput TES spectrometers can be used to study the local electronic structure of dilute metal-centered complexes relevant to biology, chemistry, and catalysis. In particular, TES spectrometers have a unique ability to characterize frozen solutions of radiation- and temperature-sensitive samples.

Translating evidence into practice: Hong Kong Reference Framework for Preventive Care for Children in Primary Care Settings.

There is increasing evidence that supports the close relationship between childhood and adult health. Fostering healthy growth and development of children deserves attention and effort. The Reference Framework for Preventive Care for Children in Primary Care Settings has been published by the Task Force on Conceptual Model and Preventive Protocols under the direction of the Working Group on Primary Care. It aims to promote health and prevent disease in children and is based on the latest research, and contributions of the Clinical Advisory Group that comprises primary care physicians, paediatricians, allied health professionals, and patient groups. This article highlights the comprehensive, continuing, and patient-centred preventive care for children and discusses how primary care physicians can incorporate the evidence-based recommendations into clinical practice. It is anticipated that the adoption of this framework will contribute to improved health and wellbeing of children.

Fetal exposure to ethanol has long-term effects on the severity of influenza virus infections.

Alcohol use by pregnant women is a significant public health issue despite well-described risks to the fetus including physical and intellectual growth retardation and malformations. Although clinical studies are limited, they suggest that in utero alcohol exposure also results in significant immune deficiencies in naive neonates. However, little is known about fetal alcohol exposure (FAE) effects on adult infections. Therefore, to determine the long-term effects of FAE on disease susceptibility and the adult immune system, we infected FAE adult mice with influenza virus. In this study, we demonstrate that mice exposed to ethanol during gestation and nursing exhibit enhanced disease severity as well as increased and sustained pulmonary viral titers following influenza virus infection. Secondary exposure to alcohol as an adult further exacerbates these effects. Moreover, we demonstrate that FAE mice have impaired adaptive immune responses, including decreased numbers of virus-specific pulmonary CD8 T cells, a decreased size and frequency of pulmonary B cell foci, and reduced production of influenza-specific Ab following influenza infection. Together, our results suggest that FAE induces significant and long-term defects in immunity and susceptibility to influenza virus infection and that FAE individuals could be at increased risk for severe and fatal respiratory infections.

Chronic ethanol induces inhibition of antigen-specific CD8+ but not CD4+ immunodominant T cell responses following Listeria monocytogenes inoculation.

Chronic ethanol consumption results in immunodeficiency. Previous work with chronic ethanol-fed mice has shown reduced splenic weight and cellularity, including reduced numbers of CD8+ T cells. However, antigen-specific CD8+ and CD4+ T cell responses in chronic ethanol-fed mice have been studied relatively little. We have used an attenuated Listeria monocytogenes strain DPL 1942 (LM DeltaactA) to inoculate mice and subsequently used CD4+ and CD8+ immunodominant peptides of LM to measure the CD4+ and CD8+ T cell responses after chronic ethanol exposure. We found no major differences between control and ethanol-fed mice in the kinetics and persistence of antigen-specific CD4+ T cells in response to an immunodominant LM peptide, as measured by intracellular IFN-gamma staining. In contrast to CD4+ responses, three methods of in vitro antigen presentation indicated that the primary response of CD8+ T cells to several different epitopes was reduced significantly in mice chronically fed ethanol. Antigen-specific CD8+ T cells were also reduced in chronic ethanol-fed mice during the contraction phase of the primary response, and memory cells evaluated at 29 and 60 days after inoculation were reduced significantly. BrdU proliferation assays showed that in vivo proliferation of CD8+ T cells was reduced in ethanol-fed mice, and IL-2-dependent in vitro proliferation of naive CD8+ T cells was also reduced. In conclusion, these results suggest that antigen-specific CD4+ T cell responses to LM are affected little by chronic ethanol consumption; however, antigen-specific CD8+ T cell responses are reduced significantly, as are in vivo and in vitro proliferation. The reduction of antigen-specific CD8+ T cells may contribute strongly to the immunodeficiency caused by ethanol abuse.

Virologically confirmed population-based burden of hospitalization caused by influenza A and B among children in Hong Kong.

BACKGROUND: We sought to determine the virologically confirmed hospitalization rates associated with influenza virus infection among Hong Kong children. METHODS: Patients <18 years of age who lived on Hong Kong Island (a separate island within Hong Kong) and were admitted to either of the only 2 public hospitals on the island for a febrile acute respiratory infection on 1 fixed day of the week in each hospital from October 2003 through September 2006 were prospectively recruited. These 2 hospitals together accounted for 72.5% of all general pediatric admissions in Hong Kong Island with a known population denominator. Nasopharyngeal aspirates were obtained from all recruited patients and were tested for influenza A and influenza B viruses by direct antigen detection and culture. RESULTS: All cases of influenza A during 2003-2004 were caused by H3N2 virus, whereas 85.7% of cases during 2004-2005 were due to H3N2 virus, and 93.5% during 2005-2006 were due to H1N1 virus. During 2004-2005, infants <1 year of age had the highest rate of hospitalization for influenza A (103.8 cases per 10,000 population), whereas children 1 year of age had the highest rate of hospitalization during the other 2 seasons (95.5 and 54.6 cases per 10,000 population during 2003-2004 and 2005-2006, respectively). A protection rate of 25%, presumably attributable to maternal antibodies, was seen in infants <1 year of age who were hospitalized during 2003-2004 with infection due to an H3N2 virus that had been in circulation. The hospitalization rates for influenza B were highest among children 2-4 years of age. CONCLUSIONS: This population-based study of hospitalizations due to virologically confirmed influenza demonstrated a very high burden of disease among young children in Hong Kong. The morbidity varied with virus type, subtype, and antigenic variants.

Soft X-ray spectroscopy with transition-edge sensors at Stanford Synchrotron Radiation Lightsource beamline 10-1.

We present results obtained with a new soft X-ray spectrometer based on transition-edge sensors (TESs) composed of Mo/Cu bilayers coupled to bismuth absorbers. This spectrometer simultaneously provides excellent energy resolution, high detection efficiency, and broadband spectral coverage. The new spectrometer is optimized for incident X-ray energies below 2 keV. Each pixel serves as both a highly sensitive calorimeter and an X-ray absorber with near unity quantum efficiency. We have commissioned this 240-pixel TES spectrometer at the Stanford Synchrotron Radiation Lightsource beamline 10-1 (BL 10-1) and used it to probe the local electronic structure of sample materials with unprecedented sensitivity in the soft X-ray regime. As mounted, the TES spectrometer has a maximum detection solid angle of 2 × 10-3 sr. The energy resolution of all pixels combined is 1.5 eV full width at half maximum at 500 eV. We describe the performance of the TES spectrometer in terms of its energy resolution and count-rate capability and demonstrate its utility as a high throughput detector for synchrotron-based X-ray spectroscopy. Results from initial X-ray emission spectroscopy and resonant inelastic X-ray scattering experiments obtained with the spectrometer are presented.

A practical method of chronic ethanol administration in mice.

Mice provide a useful model for the study of immune deficiency caused by chronic alcohol abuse. Their suitability is related to several factors, including in particular the extensive knowledge base in the immunology of mice already existing in the literature. Specific modeling of the immunodeficiency of the chronic human alcoholic requires that ethanol must be administered to the model for a significant portion of its life span. In mice, it has proven to be necessary to administer ethanol daily for up to 32 wk or longer to observe all the immune abnormalities that occur in middle-aged alcoholic humans. Such time spans are problematic with many of the common protocols for ethanol administration. It has been shown by others and confirmed by our group that the most practical way of accomplishing such long protocols is by administering ethanol in water as the only choice of water. Details of management of the chronic ethanol mouse colony are described here that are necessary for the success of such studies, including methods for initiating ethanol administration, maintenance of barrier protection, monitoring weight gain, strain differences and fetal alcohol exposure.

Polyclonal and antigen-specific responses of T cells and T cell subsets.

Evaluation of the functional responses of T cells is of importance in determining the mechanism(s) of immunodeficiency resulting from chronic alcohol abuse and other conditions that lead to immune dysfunction. Mice that are chronically exposed to 20% (w/v) ethanol in water develop immunodeficiency and have T cells with abnormal activation profiles, reduced total numbers, increased CD4/CD8 ratios, and an increased memory/naïve phenotype ratio. These cells also have abnormal antigen-specific responses after inoculation of the ethanol mice with model infectious organisms. Study of the functional abnormalities of these cells requires a reliable system that can present appropriate activation stimuli in vitro for the generation of polyclonal or antigen-specific responses in enriched or purified T cells, free of the influence of previously ethanol exposed accessory cells. In this chapter, we describe protocols to assess the T cell response to polyclonal stimulation through the T cell receptor and the use of a model infectious disease bacterium, Listeria monocytogenes, that allows evaluation of the T-cell response to specific peptide epitopes of the bacterium after previous inoculation.

Increased prevalence of constipation in pre-school children is attributable to under-consumption of plant foods: A community-based study.

AIM: To evaluate consumption of foods rich in dietary fibre and its relation to the prevalence of constipation in pre-school children. METHODS: In total, 368 children aged 3-5 years were randomly selected from kindergartens in Hong Kong. Constipation was confirmed by Rome-criteria. Children with normal bowel habits served as non-constipated controls. Consumption of vegetables, fruits, whole-grain cereals and fluid were determined using a 3-day food record. RESULTS: A total of 28.8% children were reported to have constipation. Median dietary fibre intake of constipated children was significantly lower than non-constipated children (3.4 g/d (inter-quartile range (IQR): 2.3-4.6 g/d) vs. 3.8 g/d (IQR: 2.7-4.9 g/d); P = 0.044) corresponding to 40% reference dietary fibre intake. Constipated children also had significantly lower intakes of vitamin C (P = 0.041), folate (P = 0.043) and magnesium (P = 0.002). Fruit intake and total plant foods intake were significantly lower in the constipated than non-constipated children: (61 g/d (IQR: 23.8-115 g/d) vs. 78 g/d (IQR: 41.7-144.6 g/d); P = 0.047) and (142.5 g/d (IQR: 73.7-214.7 g/d) vs. 161.1 g/d (IQR: 98.3-233.3 g/d); P = 0.034), respectively. Total fluid intake did not differ between groups but milk intake among the constipated children was marginally higher than the non-constipated children (P = 0.055) CONCLUSION: Insufficient dietary fibre intake is common in Hong Kong pre-school children. Constipated children had significantly lower intakes of dietary fibre and micronutrients including vitamin C, folate and magnesium than non-constipated counterparts which was attributable to under-consumption of plant foods. However, milk intake was marginally higher in the constipated children. More public education is necessary for parents to help develop healthy dietary habit and bowel habit in early life in order to prevent childhood constipation.

Very-high-dose phenobarbital for childhood refractory status epilepticus.

This report describes the management of three children, ranging in age from 7 to 9 years, who had refractory status epilepticus. This condition was likely the result of viral encephalitis; it manifested initially as generalized tonic-clonic seizure and later frequent subtle eye staring and twitching of mouth or limbs as well as tachycardia and dilatation of pupils. The seizures were not responsive to treatment with conventional doses of intravenous phenobarbital, phenytoin, and midazolam infusion. Very-high-dose phenobarbital was administered at accumulated daily doses up to 80 mg/kg, with a resulting serum level of more than 1000 mumol/L. It was effective in achieving seizure control, with milder adverse effects compared with thiopental infusion.

Virologically confirmed population-based burden of hospitalization caused by respiratory syncytial virus, adenovirus, and parainfluenza viruses in children in Hong Kong.

OBJECTIVES: To determine virologically confirmed hospitalization rates associated with respiratory syncytial virus (RSV), adenovirus, and parainfluenza viruses in Hong Kong children. METHODS: All patients <18 years of age living on Hong Kong Island (within Hong Kong SAR) admitted for a febrile acute respiratory infection to 1 of the 2 public hospitals on 1 fixed day of the week between October 2003 and September 2006 were prospectively recruited. Hong Kong Island has a known population denominator and these 2 hospitals managed 72.5% of all general pediatric admissions for this population. Nasopharyngeal aspirates were tested for RSV, adenovirus, and parainfluenzae types 1, 2, and 3 by direct antigen detection and culture. RESULTS: The annual hospitalization rate for RSV in infants <6 months of age was 233.4 to 311.2 per 10,000. Parainfluenza type 3 had a hospitalization rate of 27.3 to 122.8 per 10,000 in the 1 to <2 years group. Adenovirus was associated with significant hospitalization in those 6 months to 1 year (25.9-77.8 per 10,000), and in those 2 to <5 years (38.1-59.2 per 10,000). The mean duration of hospitalization for RSV was 4.04 ± 2.61 days, significantly longer than the 3.12 ± 1.41 days for adenovirus and the 2.93 ± 2.54 days for parainfluenza infections (P = 0.013 and P = 0.038, respectively). CONCLUSION: We documented that the overall pediatric hospitalization burden of RSV was high and comparable to that of influenza. The burden for all the studied viruses was mainly in previously healthy children <5 years of age.

Disordered eating attitudes and behaviours among adolescents in Hong Kong: prevalence and correlates.

AIMS: To study the prevalence of disordered eating attitudes and behaviours among adolescents in Hong Kong and to examine the socio-demographic and behavioural correlates. METHODS: Three secondary schools with different academic performance were selected from the Eastern District of Hong Kong. A total of 2382 students enrolled in Forms 1-7 at the three schools completed a specially designed questionnaire. The questionnaire contained questions on socio-demographic information, body weight satisfaction, exposure to mass media, health behaviours as well as the Eating Attitudes Test - 26 (EAT-26). Data were analysed using Student's t-test, chi2 analysis and multivariate logistic regression models. RESULTS: Disordered eating (EAT score > or =20) was present in 52 (3.9%) adolescent boys and 68 (6.5%) adolescent girls. The youngest case was only 11 years old. A high degree of body weight dissatisfaction was shared by our adolescents. Teenage girls, overweight youths and those with poor academic performance were at increased risk of having disordered eating. Strong associations were found between disordered eating and other health-compromising behaviours including smoking, alcohol and soft drug use, delinquent behaviours, suicidal ideation and self-harm behaviours. Exposure to entertainment, beauty and youth magazines was positively related to disordered eating. CONCLUSIONS: Disordered eating is prevalent among adolescents in Hong Kong. It remains a significant public health challenge to our community. Prevention programmes targeting youths at the greatest risk should be considered.

Transcutaneous bilirubinometry: a noninvasive tool for studying newborn jaundiced rats before and after exposure to light.

The homozygous Gunn rat is the most frequently used animal model for the study of neonatal jaundice. We evaluated the applicability of noninvasive transcutaneous bilirubin (TcB) measurements as an index of serum total bilirubin (STB) levels in neonatal rats by comparison to invasive STB measurements. TcB measurements were made during the first 96 h of life with the Model 101 Minolta/Air-Shields Jaundice Meter (JM) and SpectRx BiliCheck System (BC). Measurements with both devices displayed parallel TcB profiles, rapidly rising within 24 h, increasing during the next 6 h, then leveling off after 30 h. Linear regressions for the JM (n = 60) were as follows: STB (mg/dL) = 0.79 (JM) - 0.01 (units, r = 0.95, head); STB (mg/dL) = 0.82 (JM) + 1.51 (units, r = 0.95, upper back); and STB (mg/dL) = 0.74 (JM) + 1.60 (units, r = 0.91, lower back). Mean bias +/- imprecision were as follows: -0.02 +/- 3.99 mg/dL, -0.01 +/- 3.90, and 0.01 +/- 4.28 at the head, upper back, and lower back, respectively. For the BC, only lower back measurements were taken, and the regression was as follows: STB (mg/dL) = 0.77 (BC) + 1.65 mg/dL, (r = 0.93, n = 29) with a mean bias +/- imprecision of -1.08 +/- 3.08 mg/dL. When pups were exposed to light, correlations remained strong but intercepts increased. These results demonstrate that noninvasive TcB measurements correlate highly with STB in the Gunn rat during the first 96 h of life and after exposure to light. We conclude that JM measurements at the head and BC at the lower back reflect STB most reliably and consistently. Thus, in addition to being a useful tool for evaluating jaundice in human neonates, TcB methodology can be used successfully for the noninvasive monitoring of jaundice in neonatal Gunn rats pre- and postlight exposure.

Linear growth in prepubertal asthmatic children treated with montelukast, beclomethasone, or placebo: a 56-week randomized double-blind study.

BACKGROUND: Antileukotrienes and inhaled corticosteroids are asthma controller agents widely used in the treatment of pediatric asthma. OBJECTIVE: To evaluate the effects of montelukast and beclomethasone on linear growth in prepubertal asthmatic children for 1 year. METHODS: This was a 30-center study of boys (6.4-9.4 years old) and girls (6.4-8.4 years old) at Tanner stage I with mild, persistent asthma. After a placebo run-in period, 360 patients were randomized in equal ratios to double-blind, double-dummy treatment with 5 mg of montelukast, 200 microg of beclomethasone twice daily (positive control), or placebo for 56 weeks; 90% of the patients completed the study. The primary end point was linear growth velocity, measured using a stadiometer. RESULTS: Linear growth rates were similar between the montelukast and placebo groups; the mean difference for the year was 0.03 cm. The mean growth rate with beclomethasone was significantly less than with placebo (-0.78 cm) or montelukast (0.81 cm) (P < .001 for both). Median percentage of days with beta-agonist use was greater with placebo (14.58%) vs montelukast (10.55%) or beclomethasone (6.65%) (P < .05 for all). More patients used oral corticosteroid rescue with placebo (34.7%) than with montelukast (25.0%) or beclomethasone (23.5%). An imbalance in bone marker levels was seen with beclomethasone but not with montelukast. CONCLUSION: In prepubertal asthmatic children, montelukast did not affect linear growth, whereas the growth rate with beclomethasone was significantly decreased during 1 year of treatment.

SARS-related virus predating SARS outbreak, Hong Kong.

Using immunofluorescence and neutralization assays, we detected antibodies to human severe acute respiratory syndrome-associated coronavirus (SARS-CoV) and/or animal SARS-CoV-like virus in 17 (1.8%) of 938 adults recruited in 2001. This finding suggests that a small proportion of healthy persons in Hong Kong had been exposed to SARS-related viruses at least 2 years before the recent SARS outbreak.

The TGF-beta response to Leishmania chagasi in the absence of IL-12.

Cure of leishmaniasis requires a type 1 immune response characterized by IFN-gamma production. Leishmania major infection leads to a type 2 response suppressing cure of susceptible BALB/c mice, and L. major causes an exacerbated type 2 response in mouse strains with a gene knockout (KO) such that they lack IL-12p40 (IL-12KO mice). In contrast, type 1 responses are inhibited by TGF-beta without Th2 cell expansion in BALB/c mice infected with L. chagasi. We questioned whether the type 2 or the TGF-beta response would dominate during L. chagasi infection of IL-12KO mice. C57BL/6 mice developed self-resolving L. chagasi infection with abundant IFN-gamma. In contrast, L. chagasi disease was exacerbated and IFN-gamma was low in IL-12KO mice. Total TGF-beta was significantly higher in IL-12KO than control C57BL/6 mice, but IL-4 and IL-10 levels were similar. TGF-beta was further augmented in IL-12/IFN-gamma double-KO mice. Thus, in contrast to L. major, the TGF-beta response was exacerbated whereas type 2 cells were not expanded during L. chagasi infection of IL-12KO mice. We conclude that L. chagasi has an inherent propensity to elicit a prominent TGF-beta response that either suppresses, or is suppressed by, a type 1 response. We propose this be termed a "type 3" immune response, which can antagonize a type 1 response.