Amyloid-ß peptide signature associated with cerebral amyloid angiopathy in familial Alzheimer's disease with APPdup and Down syndrome.

Alzheimer's disease (AD) is characterized by extracellular amyloid plaques containing amyloid-ß (Aß) peptides, intraneuronal neurofibrillary tangles, extracellular neuropil threads, and dystrophic neurites surrounding plaques composed of hyperphosphorylated tau protein (pTau). Aß can also deposit in blood vessel walls leading to cerebral amyloid angiopathy (CAA). While amyloid plaques in AD brains are constant, CAA varies among cases. The study focuses on differences observed between rare and poorly studied patient groups with APP duplications (APPdup) and Down syndrome (DS) reported to have higher frequencies of elevated CAA levels in comparison to sporadic AD (sAD), most of APP mutations, and controls. We compared Aß and tau pathologies in postmortem brain tissues across cases and Aß peptides using mass spectrometry (MS). We further characterized the spatial distribution of Aß peptides with MS-brain imaging. While intraparenchymal Aß deposits were numerous in sAD, DS with AD (DS-AD) and AD with APP mutations, these were less abundant in APPdup. On the contrary, Aß deposits in the blood vessels were abundant in APPdup and DS-AD while only APPdup cases displayed high Aß deposits in capillaries. Investigation of Aß peptide profiles showed a specific increase in Aßx-37, Aßx-38 and Aßx-40 but not Aßx-42 in APPdup cases and to a lower extent in DS-AD cases. Interestingly, N-truncated Aß2-x peptides were particularly increased in APPdup compared to all other groups. This result was confirmed by MS-imaging of leptomeningeal and parenchymal vessels from an APPdup case, suggesting that CAA is associated with accumulation of shorter Aß peptides truncated both at N- and C-termini in blood vessels. Altogether, this study identified striking differences in the localization and composition of Aß deposits between AD cases, particularly APPdup and DS-AD, both carrying three genomic copies of the APP gene. Detection of specific Aß peptides in CSF or plasma of these patients could improve the diagnosis of CAA and their inclusion in anti-amyloid immunotherapy treatments.

Common mental health disorders and cognitive decline in a longitudinal Down syndrome cohort.

BACKGROUND: Down syndrome is the most common genetic cause of intellectual disability and Alzheimer's disease. In the general population, common mental disorders (CMDs), including anxiety, depression and obsessive-compulsive disorder, are linked to cognitive decline and higher risk for dementia. It is not known how CMDs affect longer-term cognitive outcomes in Down syndrome, and there is often diagnostic uncertainty in older people with Down syndrome and psychiatric comorbidity. AIMS: To study the influence of CMDs on cognitive ability and whether they are related longitudinally to development of clinical signs of Alzheimer's disease in Down syndrome. METHOD: We followed 115 individuals with Down syndrome, 27 of whom were diagnosed with a CMD, over approximately 3 years. Changes in cognitive and behavioural outcomes between baseline and follow-up assessment were analysed, with comparisons made between those with and without a comorbid CMD. Age, gender, apolipoprotein E status and level of intellectual disability were included as covariates. RESULTS: No significant association between presence of a CMD and poorer performance on cognitive tasks or informant-rated decline over time was observed (P > 0.05). CONCLUSIONS: Our results suggest that a diagnosis of a CMD does not have a significant negative effect on long-term cognitive or behavioural outcomes in individuals with Down syndrome. In individuals with stable or treated CMD, subsequent cognitive decline is likely indicative of Alzheimer's disease rather than a consequence of mental disorder.

Exploring semantic verbal fluency patterns and their relationship to age and Alzheimer's disease in adults with Down syndrome.

INTRODUCTION: Adults with Down syndrome (DS) are at ultra-high risk of developing Alzheimer's disease (AD), characterized by poor episodic memory and semantic fluency in the preclinical phase in the general population. We explored semantic fluency performance in DS and its relationship to age, AD, and blood biomarkers. METHODS: A total of 302 adults with DS at baseline and 87 at follow-up from the London Down Syndrome Consortium cohort completed neuropsychological assessments. Blood biomarkers were measured with the single molecule array technique in a subset of 94 participants. RESULTS: Poorer verbal fluency performance was observed as age increases. Number of correct words declined in those with AD compared to those without over 2 years and was negatively correlated with neurofilament light (r = -0.37, P = .001) and glial fibrillary acidic protein (r = -0.31, P = .012). DISCUSSION: Semantic fluency may be useful as an early indicator of cognitive decline and provide additional information on AD-related change, showing associations with biomarkers in DS.

Multiple morbidity across the lifespan in people with Down syndrome or intellectual disabilities: a population-based cohort study using electronic health records.

BACKGROUND: The Down syndrome phenotype is well established, but our understanding of its morbidity patterns is limited. We comprehensively estimated the risk of multiple morbidity across the lifespan in people with Down syndrome compared with the general population and controls with other forms of intellectual disability. METHODS: In this matched population-based cohort-study design, we used electronic health-record data from the UK Clinical Practice Research Datalink (CRPD) from Jan 1, 1990, to June 29, 2020. We aimed to explore the pattern of morbidities throughout the lifespan of people with Down syndrome compared with people with other intellectual disabilities and the general population, to identify syndrome-specific health conditions and their age-related incidence. We estimated incidence rates per 1000 person-years and incidence rate ratios (IRRs) for 32 common morbidities. Hierarchical clustering was used to identify groups of associated conditions using prevalence data. FINDINGS: Between Jan 1, 1990, and June 29, 2020, a total of 10 204 people with Down syndrome, 39 814 controls, and 69 150 people with intellectual disabilities were included. Compared with controls, people with Down syndrome had increased risk of dementia (IRR 94·7, 95% CI 69·9-128·4), hypothyroidism (IRR 10·6, 9·6-11·8), epilepsy (IRR 9·7, 8·5-10·9), and haematological malignancy (IRR 4·7, 3·4-6·3), whereas asthma (IRR 0·88, 0·79-0·98), cancer (solid tumour IRR 0·75, 0·62-0·89), ischaemic heart disease (IRR 0·65, 0·51-0·85), and particularly hypertension (IRR 0·26, 0·22-0·32) were less frequent in people with Down syndrome than in controls. Compared to people with intellectual disabilities, risk of dementia (IRR 16·60, 14·23-19·37), hypothyroidism (IRR 7·22, 6·62-7·88), obstructive sleep apnoea (IRR 4·45, 3·72-5·31), and haematological malignancy (IRR 3·44, 2·58-4·59) were higher in people with Down syndrome, with reduced rates for a third of conditions, including new onset of dental inflammation (IRR 0·88, 0·78-0·99), asthma (IRR 0·82, 0·73-0·91), cancer (solid tumour IRR 0·78, 0·65-0·93), sleep disorder (IRR 0·74, 0·68-0·80), hypercholesterolaemia (IRR 0·69, 0·60-0·80), diabetes (IRR 0·59, 0·52-0·66), mood disorder (IRR 0·55, 0·50-0·60), glaucoma (IRR 0·47, 0·29-0·78), and anxiety disorder (IRR 0·43, 0·38-0·48). Morbidities in Down syndrome could be categorised on age-related incidence trajectories, and their prevalence clustered into typical syndromic conditions, cardiovascular diseases, autoimmune disorders, and mental health conditions. INTERPRETATION: Multiple morbidity in Down syndrome shows distinct patterns of age-related incidence trajectories and clustering that differ from those found in the general population and in people with other intellectual disabilities, with implications for provision and timing of health-care screening, prevention, and treatment for people with Down syndrome. FUNDING: The European Union's Horizon 2020 Research and Innovation Programme, the Jérôme Lejeune Foundation, the Alzheimer's Society, the Medical Research Council, the Academy of Medical Sciences, the Wellcome Trust, and William Harvey Research Limited.

Complement dysregulation and Alzheimer's disease in Down syndrome.

INTRODUCTION: Down syndrome (DS) is associated with immune dysregulation and a high risk of early onset Alzheimer's disease (AD). Complement is a key part of innate immunity and driver of pathological inflammation, including neuroinflammation in AD. Complement dysregulation has been reported in DS; however, the pattern of dysregulation and its relationship to AD risk is unclear. METHODS: Plasma levels of 14 complement biomarkers were measured in 71 adults with DS and 46 controls to identify DS-associated dysregulation; impact of apolipoprotein E (APOE) ε4 genotype, single nucleotide polymorphisms (SNPs) in CLU and CR1, and dementia on complement biomarkers was assessed. RESULTS: Plasma levels of complement activation products (TCC, iC3b), proteins (C1q, C3, C9), and regulators (C1 inhibitor, factor H, FHR4, clusterin) were significantly elevated in DS versus controls while FI and sCR1 were significantly lower. In DS with AD (n = 13), C3 and FI were significantly decreased compared to non-AD DS (n = 58). Neither APOE genotype nor CLU SNPs impacted complement levels, while rs6656401 in CR1 significantly impacted plasma sCR1 levels. CONCLUSIONS: Complement is dysregulated in DS, likely reflecting the generalized immune dysregulation state; measurement may help identify inflammatory events in individuals with DS. Complement biomarkers differed in DS with and without AD and may aid diagnosis and/or prediction. HIGHLIGHTS: Complement is significantly dysregulated in plasma of people with DS who show changes in levels of multiple complement proteins compared to controls. People with DS and dementia show evidence of additional complement dysregulation with significantly lower levels of C3 and factor I compared to those without dementia. rs6656401 in CR1 was associated with significantly elevated sCR1 plasma levels in DS.

Diabetes and Obesity in Down Syndrome Across the Lifespan: A Retrospective Cohort Study Using U.K. Electronic Health Records.

OBJECTIVE: Down syndrome (DS) is the most common form of chromosomal trisomy. Genetic factors in DS may increase the risk for diabetes. This study aimed to determine whether DS is associated with an increased incidence of diabetes and the relationship with obesity across the life span compared with control patients. RESEARCH DESIGN AND METHODS: This matched population-based cohort study analyzed UK Clinical Practice Research Datalink data from 1990 to 2020. RESULTS: A total of 9,917 patients with DS and 38,266 control patients were analyzed. Diabetes rates were higher in patients with DS (incidence rate ratio 3.67; 95% CI 2.43-5.55; P < 0.0001) and peaked at a younger age (median age at diagnosis 38 [interquartile range 28-49] years vs. 53 [43-61] years in control patients). Incidence rates (per 1,000 person-years) for type 1 diabetes mellitus were 0.44 (95% CI 0.31-0.61) in patients with DS vs. 0.13 (0.09-0.17) in control patients. Type 2 diabetes mellitus (T2DM) rates were higher in patients with DS versus control patients in age-groups from 5 years up to 34 years. In patients with DS, peak mean BMI was higher and at a younger age (males 31.2 kg/m2 at age 31 years; females 32.1 kg/m2 at 43 years) versus control patients (males 29.5 kg/m2 at 54 years; females 29.2 kg/m2 at 51 years). Obesity was associated with an increased incidence of T2DM. CONCLUSIONS: At younger ages, the incidence of diabetes in patients with DS is up to four times that of control patients. Peak mean BMI is higher and established earlier in DS, contributing to T2DM risk. Further investigation into the relationship between obesity and diabetes in DS is required to inform treatment and prevention measures.

Susceptibility to COVID-19 Diagnosis in People with Down Syndrome Compared to the General Population: Matched-Cohort Study Using Primary Care Electronic Records in the UK.

BACKGROUND: During the COVID-19 pandemic, people with Down syndrome (DS) have experienced a more severe disease course and higher mortality rates than the general population. It is not yet known whether people with DS are more susceptible to being diagnosed with COVID-19. OBJECTIVE: To explore whether DS is associated with increased susceptibility to COVID-19. DESIGN: Matched-cohort study design using anonymised primary care electronic health records from the May 2021 release of Clinical Practice Research Datalink (CPRD) Aurum. SETTING: Electronic health records from approximately 1400 general practices (GPs) in England. PARTICIPANTS: 8854 people with DS and 34,724 controls matched for age, gender and GP who were registered on or after the 29th January 2020. MEASUREMENTS: The primary outcome was COVID-19 diagnosis between January 2020 and May 2021. Conditional logistic regression models were fitted to estimate associations between DS and COVID-19 diagnosis, adjusting for comorbidities. RESULTS: Compared to controls, people with DS were more likely to be diagnosed with COVID-19 (7.4% vs 5.6%, p ≤ 0.001, odds ratio (OR) = 1.35; 95% CI = 1.23-1.48). There was a significant interaction between people with DS and a chronic respiratory disease diagnosis excluding asthma and increased odds of a COVID-19 diagnosis (OR = 1.71; 95% CI = 1.20-2.43), whilst adjusting for a number of comorbidities. CONCLUSION: Individuals with DS are at increased risk for contracting COVID-19. Those with underlying lung conditions are particularly vulnerable during viral pandemics and should be prioritised for vaccinations.

Understanding inequalities in COVID-19 outcomes following hospital admission for people with intellectual disability compared to the general population: a matched cohort study in the UK.

OBJECTIVES: This study explores the hospital journey of patients with intellectual disabilities (IDs) compared with the general population after admission for COVID-19 during the first wave of the pandemic (when demand on inpatient resources was high) to identify disparities in treatment and outcomes. DESIGN: Matched cohort study; an ID cohort of 506 patients were matched based on age, sex and ethnicity with a control group using a 1:3 ratio to compare outcomes from the International Severe Acute Respiratory and emerging Infections Consortium WHO Clinical Characterisation Protocol UK. SETTING: Admissions for COVID-19 from UK hospitals; data on symptoms, severity, access to interventions, complications, mortality and length of stay were extracted. INTERVENTIONS: Non-invasive respiratory support, intubation, tracheostomy, ventilation and admission to intensive care units (ICU). RESULTS: Subjective presenting symptoms such as loss of taste/smell were less frequently reported in ID patients, whereas indicators of more severe disease such as altered consciousness and seizures were more common. Controls had higher rates of cardiovascular risk factors, asthma, rheumatological disorder and smoking. ID patients were admitted with higher respiratory rates (median=22, range=10-48) and were more likely to require oxygen therapy (35.1% vs 28.9%). Despite this, ID patients were 37% (95% CI 13% to 57%) less likely to receive non-invasive respiratory support, 40% (95% CI 7% to 63%) less likely to receive intubation and 50% (95% CI 30% to 66%) less likely to be admitted to the ICU while in hospital. They had a 56% (95% CI 17% to 102%) increased risk of dying from COVID-19 after they were hospitalised and were dying 1.44 times faster (95% CI 1.13 to 1.84) compared with controls. CONCLUSIONS: There have been significant disparities in healthcare between people with ID and the general population during the COVID-19 pandemic, which may have contributed to excess mortality in this group.

Diagnostic and prognostic performance and longitudinal changes in plasma neurofilament light chain concentrations in adults with Down syndrome: a cohort study.

BACKGROUND: Adults with Down syndrome are at an ultra-high risk of Alzheimer's disease, but diagnosis of Alzheimer's disease in this population is challenging. We aimed to validate the clinical utility of plasma neurofilament light chain (NfL) for the diagnosis of symptomatic Alzheimer's disease in Down syndrome, assess its prognostic value, and establish longitudinal changes in adults with Down syndrome. METHODS: We did a multicentre cohort study, including adults with Down syndrome (≥18 years), recruited from six hospitals and university medical centres in France, Germany, Spain, the UK, and the USA, who had been assessed, followed up, and provided at least two plasma samples. Participants were classified by local clinicians, who were masked to biomarker data, as asymptomatic (ie, no clinical suspicion of Alzheimer's disease), prodromal Alzheimer's disease, or Alzheimer's disease dementia. We classified individuals who progressed along the Alzheimer's disease continuum during follow-up as progressors. Plasma samples were analysed retrospectively; NfL concentrations were measured centrally using commercial kits for biomarker detection. We used ANOVA to evaluate differences in baseline NfL concentrations, Cox regression to study their prognostic value, and linear mixed models to estimate longitudinal changes. To account for potential confounders, we included age, sex, and intellectual disability as covariates in the analyses. FINDINGS: Between Aug 2, 2010, and July 16, 2019, we analysed 608 samples from 236 people with Down syndrome: 165 (70%) were asymptomatic, 32 (14%) had prodromal Alzheimer's disease, and 29 (12%) had Alzheimer's disease dementia; ten [4%] participants were excluded because their classification was uncertain. Mean follow-up was 3·6 years (SD 1·6, range 0·6-9·2). Baseline plasma NfL concentrations showed an area under the receiver operating characteristic curve of 0·83 (95% CI 0·76-0·91) in the prodromal group and 0·94 (0·90-0·97) in the dementia group for differentiating from participants who were asymptomatic. An increase of 1 pg/mL in baseline NfL concentrations was associated with a 1·04-fold risk of clinical progression (95% CI 1·01-1·07; p=0·0034). Plasma NfL concentrations showed an annual increase of 3·0% (95% CI 0·4-5·8) per year in the asymptomatic non-progressors group, 11·5% (4·9-18·5) per year in the asymptomatic progressors group, and 16·0% (8·4-24·0) per year in the prodromal Alzheimer's disease progressors group. In participants with Alzheimer's disease dementia, NfL concentrations increased by a mean of 24·3% (15·3-34·1). INTERPRETATION: Plasma NfL concentrations have excellent diagnostic and prognostic performance for symptomatic Alzheimer's disease in Down syndrome. The longitudinal trajectory of plasma NfL supports its use as a theragnostic marker in clinical trials. FUNDING: AC Immune, La Caixa Foundation, Instituto de Salud Carlos III, National Institute on Aging, Wellcome Trust, Jérôme Lejeune Foundation, Medical Research Council, National Institute for Health Research, EU Joint Programme-Neurodegenerative Disease Research, Alzheimer's society, Deutsche Forschungsgemeinschaft, Stiftung für die Erforschung von Verhaltens und Umwelteinflüssen auf die menschliche Gesundheit, and NHS National Institute of Health Research Applied Research Collaborations East of England, UK.

The reliability and validity of DSM 5 diagnostic criteria for neurocognitive disorder and relationship with plasma neurofilament light in a down syndrome population.

The validity of dementia diagnostic criteria depends on their ability to distinguish dementia symptoms from pre-existing cognitive impairments. The study aimed to assess inter-rater reliability and concurrent validity of DSM-5 criteria for neurocognitive disorder in Down syndrome. The utility of mild neurocognitive disorder as a distinct diagnostic category, and the association between clinical symptoms and neurodegenerative changes represented by the plasma biomarker neurofilament light were also examined. 165 adults with Down syndrome were included. Two clinicians independently applied clinical judgement, DSM-IV, ICD-10 and DSM-5 criteria for dementia (or neurocognitive disorder) to each case. Inter-rater reliability and concurrent validity were analysed using the kappa statistic. Plasma neurofilament light concentrations were measured for 55 participants as a marker of neurodegeneration and between group comparisons calculated. All diagnostic criteria showed good inter-rater reliability apart from mild neurocognitive disorder which was moderate (k = 0.494). DSM- 5 criteria had substantial concurrence with clinical judgement (k = 0.855). When compared to the no neurocognitive disorder group, average neurofilament light concentrations were higher in both the mild and major neurocognitive disorder groups. DSM-5 neurocognitive disorder criteria can be used reliably in a Down syndrome population and has higher concurrence with clinical judgement than the older DSM-IV and ICD-10 criteria. Whilst the inter-rater reliability of the mild neurocognitive disorder criteria was modest, it does appear to identify people in an early stage of dementia with underlying neurodegenerative changes, represented by higher average NfL levels.

The Association between Physical Activity and CAMDEX-DS Changes Prior to the Onset of Alzheimer's Disease in Down Syndrome.

BACKGROUND: People with Down syndrome are at ultra-high risk of developing Alzheimer's dementia. At present, there are no preventative or curative treatments. Evidence from sporadic Alzheimer's disease literature suggests that lifestyle factors including physical activity may help maintain cognitive and functional skills and reduce dementia risk. Our study aimed to explore the association between regular exercise undertaken by participants with Down syndrome and changes in dementia-related domains of cognition and function. This was to consider whether physical activity may be a protective measure to delay cognitive decline and dementia in Down syndrome. METHODS: Demographic, lifestyle, and health information was collected at baseline and at a two year follow up from 214 adults with Down syndrome without dementia, who also underwent assessment using the Cambridge Examination for Mental Disorders of Older People with Down Syndrome and Others with Intellectual Disabilities (CAMDEX-DS) and genetic analysis. Logistic regression models were used to examine the potential associations between decline in CAMDEX-DS domains and exercise whilst controlling for key variables. RESULTS: At baseline, engaging in moderate intensity exercise was associated with a 47% reduced risk of everyday skills decline and engaging in high intensity exercise was associated with a 62% reduced risk of decline in personality and behaviour. At follow-up, high levels of exercise were associated with an 87% reduced risk of decline in personality and behaviour. Moderate intensity exercise at baseline was associated with a 62% reduction in risk of decline during the follow-up period in memory and orientation. DISCUSSION: Based on our data it appears that regular moderate and high intensity exercise could reduce the risk of clinically detectable decline in a Down syndrome population with possible long-term benefits. People with Down syndrome may engage in less physical activity than their peers, and barriers remain which can prevent people with Down syndrome engaging in exercise. Our work highlights how important it is that people with Down syndrome are supported to be physically active, and to promote exercise as part of a healthy ageing plan. Clinical trials in this area would be justified to determine if engaging in exercise can lead to realistic improvements in maintaining functioning and delaying dementia onset in Down syndrome and to help develop guidance in this area.

Down syndrome.

Trisomy 21, the presence of a supernumerary chromosome 21, results in a collection of clinical features commonly known as Down syndrome (DS). DS is among the most genetically complex of the conditions that are compatible with human survival post-term, and the most frequent survivable autosomal aneuploidy. Mouse models of DS, involving trisomy of all or part of human chromosome 21 or orthologous mouse genomic regions, are providing valuable insights into the contribution of triplicated genes or groups of genes to the many clinical manifestations in DS. This endeavour is challenging, as there are >200 protein-coding genes on chromosome 21 and they can have direct and indirect effects on homeostasis in cells, tissues, organs and systems. Although this complexity poses formidable challenges to understanding the underlying molecular basis for each of the many clinical features of DS, it also provides opportunities for improving understanding of genetic mechanisms underlying the development and function of many cell types, tissues, organs and systems. Since the first description of trisomy 21, we have learned much about intellectual disability and genetic risk factors for congenital heart disease. The lower occurrence of solid tumours in individuals with DS supports the identification of chromosome 21 genes that protect against cancer when overexpressed. The universal occurrence of the histopathology of Alzheimer disease and the high prevalence of dementia in DS are providing insights into the pathology and treatment of Alzheimer disease. Clinical trials to ameliorate intellectual disability in DS signal a new era in which therapeutic interventions based on knowledge of the molecular pathophysiology of DS can now be explored; these efforts provide reasonable hope for the future.

Using ordinal logistic regression to evaluate the performance of laser-Doppler predictions of burn-healing time.

BACKGROUND: Laser-Doppler imaging (LDI) of cutaneous blood flow is beginning to be used by burn surgeons to predict the healing time of burn wounds; predicted healing time is used to determine wound treatment as either dressings or surgery. In this paper, we do a statistical analysis of the performance of the technique. METHODS: We used data from a study carried out by five burn centers: LDI was done once between days 2 to 5 post burn, and healing was assessed at both 14 days and 21 days post burn. Random-effects ordinal logistic regression and other models such as the continuation ratio model were used to model healing-time as a function of the LDI data, and of demographic and wound history variables. Statistical methods were also used to study the false-color palette, which enables the laser-Doppler imager to be used by clinicians as a decision-support tool. RESULTS: Overall performance is that diagnoses are over 90% correct. Related questions addressed were what was the best blood flow summary statistic and whether, given the blood flow measurements, demographic and observational variables had any additional predictive power (age, sex, race, % total body surface area burned (%TBSA), site and cause of burn, day of LDI scan, burn center). It was found that mean laser-Doppler flux over a wound area was the best statistic, and that, given the same mean flux, women recover slightly more slowly than men. Further, the likely degradation in predictive performance on moving to a patient group with larger %TBSA than those in the data sample was studied, and shown to be small. CONCLUSION: Modeling healing time is a complex statistical problem, with random effects due to multiple burn areas per individual, and censoring caused by patients missing hospital visits and undergoing surgery. This analysis applies state-of-the art statistical methods such as the bootstrap and permutation tests to a medical problem of topical interest. New medical findings are that age and %TBSA are not important predictors of healing time when the LDI results are known, whereas gender does influence recovery time, even when blood flow is controlled for.The conclusion regarding the palette is that an optimum three-color palette can be chosen 'automatically', but the optimum choice of a 5-color palette cannot be made solely by optimizing the percentage of correct diagnoses.

Burns in children caused by hair straighteners: epidemiology and investigation of heating/cooling curves.

We recently encountered a number of burns in young children caused by hair straighteners and decided to study their epidemiology. We carried out a retrospective audit from 1999 to 2006. We also conducted laboratory testing of the thermal profiles of four brands of hair straighteners. Eighteen children (aged 8 months to 13.5 years, mean 2.1 years) sustained hair straightener burns. Most (13/18) affected the upper limbs and six involved the lower limbs. Three (16.6%) children required surgery. The mean peak temperature of the straighteners was 169.5 degrees C (337.1 degrees F). The straighteners that we tested remained at a temperature above 80 degrees C (176 degrees F) for between 6 and 8 minutes. A third of the hair straightener burns occurred when the appliance was switched "OFF" and cooling down. The children affected are very young. Thus, any prevention campaign should target parents. Children should be well supervised and the straighteners should be placed safely out of their reach while they are cooling. Parents should be warned of the risks to young children, even when straighteners have been switched off. Manufacturers should supply suitable cooling bags.

The impact of recent legislation on paediatric fireworks injuries in the Newcastle upon Tyne region.

Despite the changes to the UK fireworks laws and considerable efforts in prevention, children are still being injured by fireworks. The UK is one of many countries that have altered their firework laws in recent years. We reviewed 54 firework-injured children over the last 10 years and assessed the impact of the two recent UK law changes. Our study outlines past British firework legislation and reviews the literature. In November 1996, there were three deaths in England, Wales and Scotland due to fireworks. The British Government introduced the Fireworks (Safety) Regulations of 1996/1997, primarily banning banger fireworks (known as bangers). We have not seen banger injuries in Newcastle since then. The Fireworks Act 2003 and the Fireworks Regulations 2004 limited the sale of fireworks to the 3 weeks surrounding bonfire night, and banned under 18s from purchasing or possessing fireworks. In our series, we noticed that, in 2004, 83% of children's firework injuries happened in the 3 weeks surrounding Bonfire Night. We conclude that legislation has had an impact, but stricter enforcement of the existing laws and further education of children and the general public into the dangers of fireworks is needed, as children are still being injured.

Evidence for the link between healing time and the development of hypertrophic scars (HTS) in paediatric burns due to scald injury.

The relationship between burn depth, healing time and the development of hypertrophic scarring (HTS) is well recognised by burn surgeons but is seldom mentioned in the published literature. We studied 337 children with scalds whose scars were monitored for up to 5 years. Overall HTS rates were found to be: under 10 days to healing=0%, 10-14 days=8%, 15-21 days=20%, 22-25 days=40%, 26-30 days=68% and over 30 days=92%. In the conservatively treated group the HTS rates are: under 10 days=0%, 10-14 days=2%, 15-21 days=20%, 22-25 days=28%, 26-30 days=75% and over 30 days=94%. If skin grafting is undertaken there is a much higher incidence of HTS in the 10-14 days group: 10-14 days=33%, 15-21 days=19%, 22-25 days=54%, 26-30 days=64% and over 30 days=88%. We conclude that there is a low risk of HTS formation in scalds healed before 21 days, and that surgery should be reserved for scalds likely to take more than 21 days to heal.

Dermal preservation using the Versajet hydrosurgery system for debridement of paediatric burns.

Loss of dermis is one of the principal factors that contributes to poor scar outcome after severe burn. Dermal loss may be due to the primary injury, surgical management or as a result of infection. Strategies for dermal preservation are therefore important to improve scar quality. We report our early experience using the Versajet hydrosurgery system, to preserve dermal tissues, both directly during surgical debridement and indirectly by reducing infection and optimising the use of biological dressings. In deep partial thickness burns softer necrotic dermis can be removed with the Versajet sparing the underlying tougher viable dermis. In superficial burns the Versajet cleans and removes loose epidermal elements providing an optimal wound surface for the application of biological dressings, even a number of days after injury. Versajet is most useful when the tissue to be removed is softer than that to be left behind.