Comparing Jupiter's Equatorial X-Ray Emissions With Solar X-Ray Flux Over 19 Years of the Chandra Mission.

We present a statistical study of Jupiter's disk X-ray emissions using 19 years of Chandra X-Ray Observatory (CXO) observations. Previous work has suggested that these emissions are consistent with solar X-rays elastically scattered from Jupiter's upper atmosphere. We showcase a new pulse invariant (PI) filtering method that minimizes instrumental effects which may produce unphysical trends in photon counts across the nearly two-decade span of the observations. We compare the CXO results with solar X-ray flux data from the Geostationary Operational Environmental Satellites X-ray Sensor for the wavelength band 1-8 Å (long channel), to quantify the correlation between solar activity and Jovian disk counts. We find a statistically significant Pearson's Correlation Coefficient of 0.9, which confirms that emitted Jovian disk X-rays are predominantly governed by solar activity. We also utilize the high spatial resolution of the High Resolution Camera Instrument on-board the CXO to map the disk photons to their positions on Jupiter's surface. Voronoi tessellation diagrams were constructed with the Juno Reference Model through Perijove 9 internal field model overlaid to identify any spatial preference of equatorial photons. After accounting for area and scattering across the curved surface of the planet, we find a preference of Jovian disk emission at 2-3.5 Gauss surface magnetic field strength. This suggests that a portion of the disk X-rays may be linked to processes other than solar scattering: the spatial preference associated with magnetic field strength may imply increased precipitation from the radiation belts, as previously postulated.

A patient with congenital hyperlactataemia and Leigh syndrome: an uncommon mitochondrial variant.

We report an uncommon mitochondrial variant in a baby girl with congenital hyperlactataemia and Leigh syndrome. The patient presented with a single episode of generalised clonic convulsion at day 19, and was found to have isolated and persistent hyperlactataemia ranging from 3.34 to 9.26 mmol/L. She had elevated serum lactate-to-pyruvate ratios of up to 35 and high plasma alanine concentration, indicative of a respiratory chain defect. At the age of 8 months, she developed evolving neurological and imaging features compatible with Leigh syndrome. Genetic testing for common mitochondrial DNA mutations, large mitochondrial DNA deletions, and selected nuclear genes was negative. Further analysis of lymphocyte mitochondrial DNA by sequencing revealed an uncommon heteroplasmic variant, NC_012920.1(MT-ND5):m.13094T>C (p.Val253Ala), which was previously shown to reduce complex I activity. In patients in whom there was a high suspicion of mitochondrial disorder, entire mitochondrial DNA analysis may be warranted if initial screening of common mitochondrial DNA mutations is negative.

Congenital fibrosis of extraocular muscle type 1A due to KIF21A mutation: first case report from Hong Kong.

With the advancement of ophthalmological genetics, the molecular basis for more and more eye diseases can be elucidated. Congenital fibrosis of extraocular muscle (CFEOM) is an example. It is characterised by a congenital non-progressive restrictive ophthalmoplegia and ptosis. It is an autosomal dominant disease, caused by mutations of the KIF21A gene. With positive family history and typical ophthalmological findings, mutational analysis of KIF21A gene should be performed, not only to confirming the diagnosis, but also to offer a prognosis, for genetic counselling, and the possibility of prenatal diagnosis. Here we report the first KIF21A mutation associated with CFEOM1A in Hong Kong.

Health-related quality of life of children with epilepsy in Hong Kong: how does it compare with that of youth with epilepsy in Canada?

OBJECTIVE: The primary aim of our study was to compare the health-related quality of life (HRQL) of children with epilepsy in Hong Kong with that of children with epilepsy in Canada, and to explore possible factors affecting these findings. A second interest was to determine agreement between proxy reports and self-ratings among children with epilepsy in Hong Kong, compare these with findings in Canada, and identify factors that influence the concordance. METHODS: Child self-report and parent-proxy questionnaires on an epilepsy-specific HRQL measure, appropriately translated and validated in Chinese, were administered to 266 Hong Kong children and their parents. An unpaired t test was used to compare the scores with published results from 381 Canadian children and their parents, who used the original English version of the measure. Demographic characteristics of the two groups were compared using t tests, chi2 tests, and Fisher's exact tests. Agreement between parents' and children's scores was evaluated with intraclass correlation coefficients (ICCs) and standardized response means (SRMs). The total HRQL score differences between parents and children in Hong Kong were compared with those in Canada using an unpaired t test. Factors that might affect the parent-child score difference were studied using Pearson correlation analysis, chi2 test, and analysis of variance. Factors studied included: sex, current age, age at diagnosis, duration of epilepsy, number of antiepileptic drugs used, type of seizure, seizure severity, cognition of the child, the type of school attended, presence of neurological problems, presence of behavioral problems, recent health care usage, education and employment status of both parents, housing status of the family, and relationship of the proxy respondent to the child. RESULTS: (1) In contrast to the Canadian sample, Hong Kong children with epilepsy were older (P<0.01), had a longer duration of epilepsy (P<0.01) and less severe seizures (P<0.01), and were more likely to attend normal schools (P<0.01). Children in Hong Kong reported more interpersonal/social difficulties (P<0.01), more worries (P<0.01), and more secrecy about their epilepsy (P<0.01). Parents in Hong Kong believed that their children perceived more worries (P<0.01) and were more secretive about their epilepsy (P<0.01). (2) Moderate to good agreement between parent-proxy response scores and child self-report scores was demonstrated (ICC=0.50-0.69, SRM=0.19-0.33). The total HRQL score differences between parent and child in Hong Kong were not different from those in Canada. None of the factors studied were related to the parent-child score difference. CONCLUSIONS: Youth with epilepsy in Hong Kong and their parents reported poorer quality of life than children with epilepsy in Canada. Further studies are necessary to identify the determinants of HRQL in children with epilepsy in different cultures. Acceptable agreement between the two ratings suggests that proxy reports can be used when child self-reports cannot be obtained.

Choroid plexus papilloma expansion over 7 years in Aicardi syndrome.

Choroid plexus papillomas have been reported in Aicardi syndrome. Management of these tumors is controversial because their natural progression in Aicardi syndrome has only been rarely documented. This report describes the progression of such a tumor over 7 years in a girl with Aicardi syndrome. A magnetic resonance imaging study at 2 months of age demonstrated a right ventricular mass that was consistent with a unilateral choroid plexus papilloma. The mass enlarged over the next 7 years without causing any clinically apparent symptoms, ventricular enlargement, hydrocephalus, or mass effect. The tumor was removed without change in behavior or development. The known cases of Aicardi syndrome associated with choroid plexus papillomas are reviewed. The heterogeneous nature of this lesion is highlighted.

Severe acute respiratory syndrome in children: experience in a regional hospital in Hong Kong.

OBJECTIVE: To report the clinical, laboratory, and radiologic features of children with severe acute respiratory syndrome (SARS) and to examine the difference between the younger and older age groups. DESIGN: Retrospective descriptive cohort study. SETTING: A regional hospital in Hong Kong. PATIENTS: Children younger than 18 yrs with SARS. RESULTS: Twenty-one children were included, with a mean age of 10.7 +/- 5.1 yrs. Children with SARS presented with fever, nonproductive cough, malaise, chills, headache, myalgia, and loss of appetite. Examination of the chest showed minimal auscultatory findings. Common laboratory findings included lymphopenia, thrombocytopenia, and mild elevations of activated partial thromboplastin time, alanine transaminase, lactic dehydrogenase, and creatine phosphokinase. Bacteriologic and virologic studies were all negative for common pathogens. Unilateral focal opacity was the commonest finding in chest radiography. High-resolution computerized tomography of the thorax was an early diagnostic tool if the chest radiograph was negative. The clinical course was less severe in comparison with adult patients. However, adolescents (age, > or =12 yrs) resembled adults in their clinical features. When compared with the younger age group, the adolescents had significantly higher temperatures, more constitutional upset, and a greater need for steroid treatment. Children younger than 12 yrs seemed less ill but had more coughing. On the whole, the outcome was favorable. CONCLUSION: Severe acute respiratory syndrome affects children, but the course is less severe. Nevertheless, the disease could have a significant psychosocial impact on children because of the potential seriousness of the disease in their adult family members.

A follow-up study of adherence and glycemic control among Hong Kong youths with diabetes.

OBJECTIVE: To extend longitudinally an earlier study of the pathway from symptoms of emotional distress (ED) through self-efficacy (SE) and adherence to glycemic control (GC) in youths with diabetes, and to examine the contribution of different specific adherence behaviors to changes in GC. METHODS: Fifty-six Hong Kong youths with diabetes received a follow-up evaluation 12-24 months after initial participation. ED, SE, self-reported adherence to medical regimen (SRA), and GC were assessed at both evaluations. RESULTS: The pathway from ED to SE to SRA to GC was replicated. Participants' SRA to regular checks on blood glucose levels, and taking steps to maintain levels in the recommended range, explained significant variance in changes in GC. CONCLUSIONS: The model offers strategies to enhance health care in youths with diabetes. Findings support the importance of adherence to the medical regimen but emphasize the complexity of the relationship between adherence behaviors and GC. Self-regulatory behaviors, rather than compliance with fixed instructions, appear to have the most impact on GC.