Paediatrics (RCH) - Research Publications
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ItemStability of combined Le Fort I maxillary advancement and mandibular reduction.(Walter de Gruyter GmbH, 2003-11)BACKGROUND: There have been reports that correction of severe Class III abnormality by single jaw surgery may invite relapse in the long-term. The purpose of this study was to retrospectively evaluate the stability of combined Le Fort I maxillary advancement and bilateral sagittal split osteotomies for mandibular reduction. METHODS: Thirty patients with a skeletal Class III malocclusion underwent bimaxillary surgery using rigid fixation and interpositional bone grafting of the maxilla. The average age was 24.4 years, and the mean follow-up period was 20 months (Range: 12-63 months). Post-operative changes were measured on lateral cephalometric radiographs using an anatomical best-fit technique. RESULTS: The maxilla was advanced, on average, 6.1 mm (SD: 1.8 mm) and repositioned superiorly at PNS 1.9 mm (SD: 2.1 mm). The mandible was repositioned posteriorly 5.6 mm ISD: 4.2 mm) at menton, which also auto-rotated superiorly. At follow-up, the maxilla relapsed horizontally 0.6 mm (SD: 1.1 mm, p < 0.01) with no significant vertical change. The maxillary central incisors were proclined and the interincisal angle was reduced. Menton relapsed anteriorly 1.4 mm (SD: 2.7 mm, p < 0.01), and gonion rotated superiorly 1.5 mm (SD: 2.3 mm, p < 0.001). In 67 per cent of cases menton moved anteriorly less than 2.5 mm. The overjet and overbite did not change significantly. CONCLUSIONS: The data show that 12-months post-operatively, maxillary advancement combined with mandibular setback was relatively stable in the horizontal and vertical planes.
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ItemNo Preview AvailableNormal skeletal development of mice lacking matrilin 1:: Redundant function of matrilins in cartilage?(AMER SOC MICROBIOLOGY, 1999-11)Matrilin 1, or cartilage matrix protein, is a member of a novel family of extracellular matrix proteins. To date, four members of the family have been identified, but their biological role is unknown. Matrilin 1 and matrilin 3 are expressed in cartilage, while matrilin 2 and matrilin 4 are present in many tissues. Here we describe the generation and analysis of mice carrying a null mutation in the Crtm gene encoding matrilin 1. Anatomical and histological studies demonstrated normal development of homozygous mutant mice. Northern blot and biochemical analyses show no compensatory up-regulation of matrilin 2 or 3 in the cartilage of knockout mice. Although matrilin 1 interacts with the collagen II and aggrecan networks of cartilage, suggesting that it may play a role in cartilage tissue organization, studies of collagen extractability indicated that collagen fibril maturation and covalent cross-linking were unaffected by the absence of matrilin 1. Ultrastructural analysis did not reveal any abnormalities of matrix organization. These data suggest that matrilin 1 is not critically required for cartilage structure and function and that matrilin 1 and matrilin 3 may have functionally redundant roles.
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ItemANTIGENIC VARIATION IN PLASMODIUM-FALCIPARUM(NATL ACAD SCIENCES, 1991-10)Antigenic variation of infectious organisms is a major factor in evasion of the host immune response. However, there has been no definitive demonstration of this phenomenon in the malaria parasite Plasmodium falciparum. In this study, cloned parasites were examined serologically and biochemically for the expression of erythrocyte surface antigens. A cloned line of P. falciparum gave rise to progeny that expressed antigenically distinct forms of an erythrocyte surface antigen but were otherwise identical. This demonstrates that antigenic differences on the surface of P. falciparum-infected erythrocytes can arise by antigenic variation of clonal parasite populations. The antigenic differences were shown to result from antigenic variation of the parasite-encoded protein, the P. falciparum erythrocyte membrane protein 1.
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ItemA cross-sectional survey of complementary and alternative medicine use by children and adolescents attending the University Hospital of Wales.(Springer Science and Business Media LLC, 2006-05-02)BACKGROUND: A high prevalence of CAM use has been documented worldwide in children and adolescents with chronic illnesses. Only a small number of studies, however, have been conducted in the United Kingdom. The primary aim of this study was to examine the use of CAM by children and adolescents with a wide spectrum of acute and chronic medical problems in a tertiary children's hospital in Wales. METHODS: Structured personal interviews of 100 inpatients and 400 outpatients were conducted over a 2-month period in 2004. The yearly and monthly prevalence of CAM use were assessed and divided into medicinal and non-medicinal therapies. This use was correlated with socio-demographic factors. RESULTS: There were 580 patients approached to attain 500 completed questionnaires. The use of at least one type of CAM in the past year was 41% (95% CI 37-46%) and past month 26% (95% CI 23-30%). The yearly prevalence of medicinal CAM was 38% and non-medicinal 12%. The users were more likely to have parents that were tertiary educated (mother: OR = 2.3, 95%CI 1.6-3.3) and a higher family income (Pearson chi-square for trend = 14.3, p < 0.001). The most common medicinal types of CAM were non-prescribed vitamins and minerals (23%) and herbal therapies (10%). Aromatherapy (5%) and reflexology (3%) were the most prevalent non-medicinal CAMs. None of the inpatient medical records documented CAM use in the past month. Fifty-two percent of medicinal and 38% of non-medicinal CAM users felt their doctor did not need to know about CAM use. Sixty-six percent of CAM users did not disclose the fact to their doctor. Three percent of all participants were using herbs and prescription medicines concurrently. CONCLUSION: There is a high prevalence of CAM use in our study population. Paediatricians need to ensure that they ask parents and older children about their CAM usage and advise caution with regard to potential interactions.CAM is a rapidly expanding industry that requires further evidence-based research to provide more information on the effectiveness and safety of many CAM therapies. Statutory or self-regulation of the different segments of the industry is important. Integration of CAM with allopathic western medicine through education and better communication is slowly progressing.
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ItemParental exercise is associated with Australian children's extracurricular sports participation and cardiorespiratory fitness: A cross-sectional study.(Springer Science and Business Media LLC, 2005-04-06)BACKGROUND: The relationship between parental physical activity and children's physical activity and cardiorespiratory fitness has not been well studied in the Australian context. Given the increasing focus on physical activity and childhood obesity, it is important to understand correlates of children's physical activity. This study aimed to investigate whether parental exercise was associated with children's extracurricular sports participation and cardiorespiratory fitness. METHODS: The data were drawn from a nationally representative sample (n = 8,484) of 7-15 year old Australian schoolchildren, surveyed as part of the Australian Schools Health and Fitness Survey in 1985. A subset of 5,929 children aged 9-15 years reported their participation in extracurricular sports and their parents' exercise. Cardiorespiratory fitness was measured using the 1.6 km (1-mile) run/walk and in addition for children aged 9, 12 or 15 years, using a physical work capacity test (PWC170). RESULTS: While the magnitude of the differences were small, parental exercise was positively associated with children's extracurricular sports participation (p < 0.001), 1.6 km run/walk time (p < 0.001) and, in girls only, PWC170 (p = 0.013). In most instances, when only one parent was active, the sex of that parent was not an independent predictor of the child's extracurricular sports participation and cardiorespiratory fitness. CONCLUSION: Parental exercise may influence their children's participation in extracurricular sports and their cardiorespiratory fitness levels. Understanding the correlates of children's extracurricular sport participation is important for the targeting of health promotion and public health interventions, and may influence children's future health status.
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ItemDeclining lung cancer mortality of young Australian women despite increased smoking is linked to reduced cigarette 'tar' yields.(Springer Science and Business Media LLC, 2001-02-02)Lung cancer data were examined to determine whether the mortality rates of young Australian women have continued to increase in line with the proportions of them who have smoked tobacco. Trends in annual age-specific lung cancer mortality were estimated for 1965-1998. Age-specific mortality rates and age-adjusted ratios of mortality rates were calculated for birth cohorts. Proportions of smokers in those cohorts were estimated from results of eight national surveys of smoking, and their mean ages of commencement and years of smoking were assessed from surveys of smokers in two states. Lung cancer mortality rates of 20-44-year-old Australian women peaked in 1986. Age-adjusted mortality rates are lower for women born in the 1950s and 1960s than for women born in the 1940s, despite higher proportions of smokers, younger age of commencement and longer duration of smoking by age 30 years in the more recent cohorts. Increased smoking has not resulted in higher lung cancer mortality for Australian women born in the 1950s and 1960s. Reductions in tar yields of Australian-made cigarettes, which would have affected primarily those born after the 1940s, may be responsible.
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ItemDifferences between Belgian and Brazilian Group A Streptococcus Epidemiologic Landscape(PUBLIC LIBRARY SCIENCE, 2006-12-20)BACKGROUND: Group A Streptococcus (GAS) clinical and molecular epidemiology varies with location and time. These differences are not or are poorly understood. METHODS AND FINDINGS: We prospectively studied the epidemiology of GAS infections among children in outpatient hospital clinics in Brussels (Belgium) and Brasília (Brazil). Clinical questionnaires were filled out and microbiological sampling was performed. GAS isolates were emm-typed according to the Center for Disease Control protocol. emm pattern was predicted for each isolate. 334 GAS isolates were recovered from 706 children. Skin infections were frequent in Brasília (48% of the GAS infections), whereas pharyngitis were predominant (88%) in Brussels. The mean age of children with GAS pharyngitis in Brussels was lower than in Brasília (65/92 months, p<0.001). emm-typing revealed striking differences between Brazilian and Belgian GAS isolates. While 20 distinct emm-types were identified among 200 Belgian isolates, 48 were found among 128 Brazilian isolates. Belgian isolates belong mainly to emm pattern A-C (55%) and E (42.5%) while emm pattern E (51.5%) and D (36%) were predominant in Brasília. In Brasília, emm pattern D isolates were recovered from 18.5% of the pharyngitis, although this emm pattern is supposed to have a skin tropism. By contrast, A-C pattern isolates were infrequently recovered in a region where rheumatic fever is still highly prevalent. CONCLUSIONS: Epidemiologic features of GAS from a pediatric population were very different in an industrialised country and a low incomes region, not only in term of clinical presentation, but also in terms of genetic diversity and distribution of emm patterns. These differences should be taken into account for designing treatment guidelines and vaccine strategies.
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ItemClusters of internally primed transcripts reveal novel long noncoding RNAs(PUBLIC LIBRARY SCIENCE, 2006-04)Non-protein-coding RNAs (ncRNAs) are increasingly being recognized as having important regulatory roles. Although much recent attention has focused on tiny 22- to 25-nucleotide microRNAs, several functional ncRNAs are orders of magnitude larger in size. Examples of such macro ncRNAs include Xist and Air, which in mouse are 18 and 108 kilobases (Kb), respectively. We surveyed the 102,801 FANTOM3 mouse cDNA clones and found that Air and Xist were present not as single, full-length transcripts but as a cluster of multiple, shorter cDNAs, which were unspliced, had little coding potential, and were most likely primed from internal adenine-rich regions within longer parental transcripts. We therefore conducted a genome-wide search for regional clusters of such cDNAs to find novel macro ncRNA candidates. Sixty-six regions were identified, each of which mapped outside known protein-coding loci and which had a mean length of 92 Kb. We detected several known long ncRNAs within these regions, supporting the basic rationale of our approach. In silico analysis showed that many regions had evidence of imprinting and/or antisense transcription. These regions were significantly associated with microRNAs and transcripts from the central nervous system. We selected eight novel regions for experimental validation by northern blot and RT-PCR and found that the majority represent previously unrecognized noncoding transcripts that are at least 10 Kb in size and predominantly localized in the nucleus. Taken together, the data not only identify multiple new ncRNAs but also suggest the existence of many more macro ncRNAs like Xist and Air.
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ItemBivariate variance-component analysis, with application to systolic blood pressure and total cholesterol levels in the Framingham Heart Study(BIOMED CENTRAL LTD, 2003-12-31)BACKGROUND: The correlations between systolic blood pressure (SBP) and total cholesterol levels (CHOL) might result from genetic or environmental factors that determine variation in the phenotypes and are shared by family members. Based on 330 nuclear families in the Framingham Heart Study, we used a multivariate normal model, implemented in the software FISHER, to estimate genetic and shared environmental components of variation and genetic and shared environmental correlation between the phenotypes. The natural logarithm of the phenotypes measured at the last visit in both Cohort 1 and 2 was used in the analyses. The antihypertensive treatment effect was corrected before adjustment of the systolic blood pressure for age, sex, and cohort. RESULTS: The univariate correlation coefficient was statistically significant for sibling pairs and parent-offspring pairs, but not significant for spouse pairs. In the bivariate analysis, the cross-trait correlation coefficients were not statistically significant for all relative pairs. The shared environmental correlation was statistically significant, but the genetic correlation was not significant. CONCLUSION: There is no significant evidence for a close genetic correlation between systolic blood pressure and total cholesterol levels. However, some shared environmental factors may determine the variation of both phenotypes.
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ItemMdm38 interacts with ribosomes and is a component of the mitochondrial protein export machinery(ROCKEFELLER UNIV PRESS, 2006-02-13)Saccharomyces cerevisiae Mdm38 and Ylh47 are homologues of human Letm1, a protein implicated in Wolf-Hirschhorn syndrome. We analyzed the function of Mdm38 and Ylh47 in yeast mitochondria to gain insight into the role of Letm1. We find that mdm38Delta mitochondria have reduced amounts of certain mitochondrially encoded proteins and low levels of complex III and IV and accumulate unassembled Atp6 of complex V of the respiratory chain. Mdm38 is especially required for efficient transport of Atp6 and cytochrome b across the inner membrane, whereas Ylh47 plays a minor role in this process. Both Mdm38 and Ylh47 form stable complexes with mitochondrial ribosomes, similar to what has been reported for Oxa1, a central component of the mitochondrial export machinery. Our results indicate that Mdm38 functions as a component of an Oxa1-independent insertion machinery in the inner membrane and that Mdm38 plays a critical role in the biogenesis of the respiratory chain by coupling ribosome function to protein transport across the inner membrane.