Antioxidant action and effectiveness of sulfur-containing amino acid during deep frying.

The aim of the study was to solve the mystery why sulfur-containing amino acids such as methionine can perform as an antioxidant during frying and hypothesized the antioxidative mechanisms. The results of this study revealed that sulfur-containing amino acids such as methionine failed to show DPPH· scavenging activity at room temperature but had valuable antioxidant activity based on OSI test at heated temperature. NMR analysis proved that methionine formed an intermediate molecule, 3-(methylthio)propylamine via decarboxylation during pyrolysis at heated temperature which was responsible for its antioxidant activity as shown by the OSI results. The mechanisms showed the proposed antioxidant behavior of methionine at heated temperature: (1) At heated temperature, 3-(methylthio)propylamine is generated by decarboxylation and (2) The antioxidant activity of 3-(methylthio)propylamine might be ascribed to the cooperation of amino group and the methylsulf-hydryl group in 3-methylthiopropylamine. From the frying study, methionine showed about 50% lower antioxidant capacity when compared TBHQ (tert-butylhydroquinone) based on OSI study, however, it has unexpected superior antioxidant activity under frying conditions that was on par with TBHQ. In summary, sulfur-containing amino acids with excellent antioxidant abilities might be useful for the food processing industry as antioxidant additives to extend shelf-life of food or food products.

Improving the frying performance of RBD palm olein oil using NaturFORT™ TRLG 101 liquid as on-top of TBHQ in deep-fat frying of potato chips.

Improvement in the frying performance of palmolein oil with NaturFORT™ TRLG 101 (TRLG 101) liquid in addition to tert-butyl hydroquinone (TBHQ) has been evaluated. Four treatment groups (Negative control, 200 ppm TBHQ, 200 ppm TBHQ + 400 ppm TRLG 101 liquid and 200 ppm TBHQ + 750 ppm TRLG 101 liquid) were added to RBD (Refined, Bleached and Deodorized) palm olein oil which was used to produce potato chips. Frying trials were conducted for 120th frying cycles. The oil samples were analyzed for peroxide value, free fatty acid, p-anisidine value, oxidative stability index, %total polar compounds and Chroma (C*) values after every 20 frying cycles. Potato chips were analyzed for Chroma (C*) values after every 20 frying cycles. The results of oxidative stability index, total polar compounds and p-anisidine value showed that the addition of NaturFORT™ TRLG 101 liquid at 750 ppm had showed significantly better performance followed by the addition of NaturFORT™ TRLG 101 liquid at 400 ppm. Thus, the addition of NaturFORT™ TRLG 101 liquid as on top of TBHQ contributes to the improvement in the frying performance of palm olein oil with subject to their dosage and this could be a better solution for frying industries which would like to get extra frying cycles for their products without encountering the regulatory hurdles posed by the limitations of using such additives.

The bioefficacy of microemulsified natural pigments in egg yolk pigmentation.

1. This study was designed to test the hypothesis that microemulsified carotenoid products show improved bioavailability over corresponding regular preparations, leading to greater yolk pigmentation at lower dosages. 2. The first trial was conducted using a maize-soya bean basal diet supplemented with either 0.25, 0.5, 0.75, 1.0 and 1.25 g/kg of microemulsified Red or non-microemulsified Red. The second trial involved feeding microemulsified Yellow or non-microemulsified Yellow using a similar dosage range. The layers were divided into 4 replicates of 8 layers each (32 layers per treatment). The 8 cages of layers were fed from a single feed trough. Feed and water were provided ad libitum throughout the trial. Each week, the eggs were collected. The whole liquid egg colour was determined by means of a commercially available yolk colour fan. Where required, HPLC-(high-performance liquid chromatography) based analysis of trans-capsanthin or trans-lutein equivalents using the Association of Analytical Communities method was carried out. Data were statistically analysed by one-way ANOVA method using Statgraphics. 3. Results showed that the colour and carotenoid content of the egg yolk increased with increasing amount of carotenoids in the diet. The colour of egg yolks from layers fed similar concentrations of microemulsified versus the regular preparation was significantly different. At the commercial recommended dose of one g/kg regular Yellow or Red product, the microemulsified pigmenter is able to provide the equivalent yolk colour at a 20-30% lower dose. 4. In conclusion, the trial results supported the hypothesis that a desired yolk colour score is achievable at a significantly lower inclusion rate when carotenoid molecules are emulsified using the microemulsion nanotechnology.

Epidemiology and risk factors for severe respiratory syncytial virus infections requiring pediatric intensive care admission in Hong Kong children.

PURPOSE: Respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infection in young children. However, there are limited data on severe RSV infection requiring pediatric intensive care unit (PICU) admission. This retrospective study described features of RSV-associated PICU admissions in Hong Kong and investigated factors for mortality and duration of PICU stay. METHODS: Children with laboratory-confirmed RSV infection and admitted to the PICUs of all eight government hospitals in Hong Kong between January 2009 and June 2011 were identified from computerized auditing systems and PICU databases. RSV in respiratory samples was detected by direct immunofluorescence and/or viral culture. The relationships between mortality and PICU duration and demographic and clinical factors were analyzed. RESULTS: A total of 118 (2.4 %) PICU admissions were identified among 4,912 RSV-positive pediatric cases in all hospitals. Sixty-five (55.6 %) patients were infants. PICU admissions were higher between October and March. Eight (6.8 %) patients died, but only two were infants. RSV-associated mortality was related to prior sick contact, presence of older siblings, neurodevelopmental conditions, chromosomal and genetic diseases, and bacterial co-infections, but none was significant following logistic regression analyses (odds ratio 9.36, 95 % confidence interval 0.91-96.03 for prior sick contact, p = 0.060). Chronic lung disease was the only risk factor for the duration of PICU admission (ß = 0.218, p = 0.017). CONCLUSIONS: The majority of RSV-infected children do not require PICU support. There is winter seasonality for RSV-associated PICU admission in Hong Kong. Prior sick contact is the only risk factor for RSV-associated mortality, whereas the presence of chronic lung disease is associated with longer PICU stay. The current risk-based approach of RSV prophylaxis may not be effective in reducing severe RSV infections.

Pseudomembranous necrotising pharyngitis in a child with Pseudomonas aeruginosa bacteraemia.

Pseudomonas aeruginosa is a common infection in immunocompromised patients. However, it can also cause severe infections in otherwise healthy individuals. We describe pseudomonal bacteraemia in a 6-month-old boy with significant obstruction of the nasopharynx by pseudomonal debris, which we termed pseudomembranous nectrotising pharyngitis. To prevent aspiration and suffocation, early recognition and removal of the obstruction by endoscopy is recommended.

Pharyngomalacia as a cause of severe neonatal stridor.

A male neonate presented at 24 hours with stridor and respiratory distress. Flexible bronchoscopy showed pharyngomalacia, i.e. complete pharyngeal wall collapse during inspiration. Assessment of upper airway dynamics is emphasised. Pharyngomalacia seems to be a self-limiting condition in our case.

Application of artificial neural networks to establish a predictive mortality risk model in children admitted to a paediatric intensive care unit.

INTRODUCTION: Paediatric risk of mortality and paediatric index of mortality (PIM) are the commonly-used mortality prediction models (MPM) in children admitted to paediatric intensive care unit (PICU). The current study was undertaken to develop a better MPM using artificial neural network, a domain of artificial intelligence. METHODS: The purpose of this retrospective case series was to compare an artificial neural network (ANN) model and PIM with the observed mortality in a cohort of patients admitted to a five-bed PICU in a Hong Kong non-teaching general hospital. The patients were under the age of 17 years and admitted to our PICU from April 2001 to December 2004. Data were collected from each patient admitted to our PICU. All data were randomly allocated to either the training or validation set. The data from the training set were used to construct a series of ANN models. The data from the validation set were used to validate the ANN and PIM models. The accuracy of ANN models and PIM was assessed by area under the receiver operator characteristics (ROC) curve and calibration. RESULTS: All data were randomly allocated to either the training (n=274) or validation set (n=273). Three ANN models were developed using the data from the training set, namely ANN8 (trained with variables required for PIM), ANN9 (trained with variables required for PIM and pre-ICU intubation) and ANN23 (trained with variables required for ANN9 and 14 principal ICU diagnoses). Three ANN models and PIM were used to predict mortality in the validation set. We found that PIM and ANN9 had a high ROC curve (PIM: 0.808, 95 percent confidence interval 0.552 to 1.000, ANN9: 0.957, 95 percent confidence interval 0.915 to 1.000), whereas ANN8 and ANN23 gave a suboptimal area under the ROC curve. ANN8 required only five variables for the calculation of risk, compared with eight for PIM. CONCLUSION: The current study demonstrated the process of predictive mortality risk model development using ANN. Further multicentre studies are required to produce a representative ANN-based mortality prediction model for use in different PICUs.

Obstructive sleep apnoea in children with Down syndrome.

INTRODUCTION: Children with Down syndrome (DS) are prone to develop obstructive sleep apnoea (OSA) for a combination of reasons, including small upper airway, midfacial hypoplasia, micrognathia and muscular hypotonia. The objective of this study was to compare the prevalence of OSA in DS children, with or without snoring, with snoring children matched for gender, age and weight for height. METHODS: DS children were prospectively recruited from the Hong Kong Down Syndrome Association. All recruited DS children underwent a sleep polysomnography (PSG) in our sleep laboratory. The same number of patients without DS who underwent sleep PSG in the same period were enrolled as controls after they were matched for gender, age and weight for height. OSA was defined as apnoea-hypopnoea index (AHI) greater than 1.5. RESULTS: 22 DS patients and 22 snoring controls completed the overnight PSG. The mean age of DS children and snoring controls was 10.82 +/- 5.93 and 10.27 +/- 5.68 years, respectively. The prevalence of OSA was 59 percent in DS children and 32 percent in snoring controls. Median and interquartile range (IQR) of AHI of DS children (median 1.80, IQR is 0.40 to 7.10) were significantly higher than those of controls (median 0.50, IQR is 0.00 to 2.03, p-value equals 0.041). Out of 13 DS children with OSA, eight of them (61.5 percent) had no habitual snoring. CONCLUSION: 59 percent of DS children in the current series were found to have OSA and they were more likely to develop OSA than controls. Nearly 40 percent of DS children with OSA did not have habitual snoring.

Assessment of the Pediatric Index of Mortality (PIM) and the Pediatric Risk of Mortality (PRISM) III score for prediction of mortality in a paediatric intensive care unit in Hong Kong.

OBJECTIVE: To compare two models (The Pediatric Risk of Mortality III score and Pediatric Index of Mortality) for prediction of mortality in a paediatric intensive care unit in Hong Kong. DESIGN: Prospective case series. SETTING: A five-bed paediatric intensive care unit in a general hospital in Hong Kong. PATIENTS: All patients consecutively admitted to the unit between April 2001 and March 2003. MAIN OUTCOME MEASURES: Scores for both models compared with observed mortality. RESULTS: A total of 303 patients were admitted to the paediatric intensive care unit during the study period. The median age was 2 years, with an interquartile range of 7 months to 7 years. The male to female ratio was 169:134 (55.8%:44.2%). The median length of hospital stay was 3 days. The overall predicted number of deaths using The Pediatric Risk of Mortality III score was 10.2 patients whereas that by Pediatric Index of Mortality was 13.2 patients. The observed mortality was eight patients. The area under the receiver operating characteristics curve for the two models was 0.910 and 0.912, respectively. CONCLUSION: The predicted mortality using both prediction models correlated well with the observed mortality.

Chronic cough in children.

Chronic cough, defined as coughing for more than four weeks, is a common childhood complaint. With careful history-taking and appropriate investigations, a single cause can be found in most cases--these can be successfully treated. Although we have some understanding about the cough reflex through animal studies, the full mechanism and exact location of the responsible neurons in the human brain have not been completely elucidated. There are many causes for it but asthma, chronic rhinosinusitis and gastroesophageal reflux disease account for most of the cases. Other causes, such as dysfunctional swallowing, congenital anomalies and cigarette smoking, are also important. All children with chronic cough deserve a thorough and proper evaluation. The current review provides essential information for medical practitioners to approach this problem. An algorithm is provided to aid the diagnostic process.

Microemulsion processing of silica-polymer nanocomposites.

Silica-polymer nanocomposites have been synthesized via polymerizable bicontinuous microemulsions to disperse functionalized/nonfunctionalized SiO2 nanoparticles uniformly in a polymerized microemulsion system as revealed by transmission electron microscopy. The effect of both types of SiO2 nanoparticles in the polymerized microemulsion increased its glass transition temperature (Tg) from 90 to 128 degrees C. TgS of functionalized silica nanocomposites were about 15 degrees C higher than those of nonfunctionalized samples. As expected, both hardness and modulus of the nanocomposites increased with the loading of both types of silica from 2 to 6 wt%. In the case of nonfunctionalized silica, the improvement of properties may be simply exerted by the conventional filler effect due to the better dispersion of nanoparticles of silica in fluid microemulsion prior to the polymerization. The additional effect for the functionalized silica containing a terminal vinyl group is that It could be grafted to the polymer matrix through cross-polymerization with microemulsion-formed polymer to establish strong nanocomposite networks.

Obstructive sleep apnoea syndrome and obesity in children.

OBJECTIVE: To review data on children who have both obesity and obstructive sleep apnoea syndrome. DATA SOURCE: Pubmed and MEDLINE (Ovid) literature search using the following key words: obstructive sleep apnea syndrome, obesity, and children. STUDY SELECTION: Literature and data on obesity-associated obstructive sleep apnoea syndrome in children. DATA EXTRACTION: Review of relevant information and data. DATA SYNTHESIS: Different definitions of obesity and obstructive sleep apnoea syndrome in children were used in different studies, which made it difficult to compare results from different studies conducted in different countries. Nonetheless, obstructive sleep apnoea syndrome was found to be moderately prevalent among obese children-namely, 13% to 36%. The severity of obstructive sleep apnoea syndrome was positively related to the degree of obesity. Blood pressure was found to be elevated in obese children with obstructive sleep apnoea syndrome. Weight reduction is an effective treatment. CONCLUSION: Children with obesity and obstructive sleep apnoea syndrome face a double challenge. A holistic approach to management requires a clear understanding of how both problems interact.

Clinical risk factors for obstructive sleep apnoea in children.

OBJECTIVE: To identify the clinical factor(s) that identify obstructive sleep apnoea syndrome (OSAS) in children. METHODS: A prospective study of children referred to the sleep clinic of the paediatric department was conducted in a public non-teaching regional hospital in Hong Kong. A standard questionnaire was administered and overnight sleep polysomnography was performed in a consecutive series of patients. Logistic regression analysis was performed to obtain significant risk factors for prediction of OSAS in this series of patients. RESULTS: Sixty-two children were enrolled into the study and 22 were diagnosed to have OSAS. Logistic regression analysis showed that, among all the answers, 'snoring every night' is the single most significant risk factor (p<0.0001) to predict OSAS. 'Snoring every night' has a sensitivity of 91% and specificity of 75% for OSAS patients. It also has a positive predictive value of 67% and negative predictive value of 94%. CONCLUSION: Snoring every night is an important risk factor in identifying OSAS in children. Priority for an overnight sleep polysomnogram should be given to those with this symptom.

Ruthenium(II) complexes in polymerised bicontinuous microemulsions.

Novel polymerised bicontinuous microemulsions can provide unique microenvironments for some functional molecules of scientific interests and practical applications.

Nanoparticles of latexes from commercial polystyrene.

Nanoparticles of polystyrene (PS) (Mw = 1.0-3.0 x 10(6) g/mol) latexes have been successfully prepared from their respective dilute PS (commercial) solutions in cyclohexane, toluene/methanol, or cyclohexane/toluene at each theta temperature. The cationic surfactant cetyltrimethylammonium bromide (CTAB) was used to stabilize the formed PS latex particles. By varying different concentrations of CTAB and PS solution of various Mw, we have successfully produced, for the first time, stable bluish-transparent latex particles ranging from about 10 to 30 nm in diameter (Dw). The number of polymer chains per latex particle (np) is directly proportional to the volume occupied by each latex particle and hence associated to its Dw. The characteristics of these preformed PS latex particles are quite similar to those obtained from the microemulsion polymerization of styrene as reported in literature. These PS latex particles could be further grown by seeding polymerization of styrene to about 50 nm (Dw) with a monodisperse size distribution of Dw/Dn = 1.08.

A randomized controlled trial of azithromycin and amoxycillin/clavulanate in the management of subacute childhood rhinosinusitis.

OBJECTIVE: Subacute childhood rhinosinusitis is a disorder commonly seen in children with allergic rhinitis. Antibiotics have been recommended as a major component of the treatment regime. The objective of the present study was to compare the effectiveness of a 3-day course of azithromycin and a 2-week course of amoxycillin/clavulanate in the treatment of subacute childhood rhinosinusitis. METHODOLOGY: A randomized single-blinded control study of subacute rhinosinusitis was conducted, comparing a 3-day course of azithromycin and a 2-week course of amoxycillin/clavulanate. Inclusion criteria were children aged between 5 and 16 years, duration of nasal blockage or discharge between 30 and 120 days, and abnormal sinus radiographs. All enrolled children were prescribed budesonide nasal spray (Rhinocort Aqua Nasal Spray, Astra Pharmaceuticals, Sodertalje, Sweden) as adjuvant treatment. RESULTS: Forty-two children were recruited into the study and one defaulted on follow-up. Failure occurred in 6 of 20 for the azithromycin group and 5 of 21 for the amoxycillin/clavulanate group. The odds ratio was 1.46 (95%CI 0.37-5. 80, P = 0.73). No relapse occurred in azithromycin group and 5 of 21 in amoxycillin/clavulanate group. The odds ratio was 0.16 (95%CI 0. 017-1.51, P = 0.18). Both antibiotics were well tolerated, however, two children, one from each group, complained of mild transient epigastric discomfort. CONCLUSIONS: This small study did not provide evidence of a difference between 14 days of amoxycillin/clavulanate and 3 days of azithromycin. Larger studies will be needed to determine which, if any, antibiotic regimen should be used in treating subacute childhood rhinosinusitis.