Search

Objectives: A systematic review and meta-analysis were conducted to determine if children born with cleft lip and/or palate are at increased risk of psychological and peer difficulties, and if so, which difficulties they develop., Methods: EMBASE, MEDLINE, and PsycINFO were searched for English language studies published between January 2005 and January 2022 which investigated the psychological outcomes and peer function of children with nonsyndromic cleft lip and palate. Outcomes included internalizing problems, such as anxiety and depression, externalizing problems, such as hyperactivity, conduct disorders, self-concept including self-image and self-esteem, peer problems, resilience, coping, and overall psychological function. A risk of bias assessment was performed using the Newcastle-Ottawa Scale. Random effects models were used in the meta-analysis to compare the outcomes for children born with a cleft and those without., Results: In total 41 studies met inclusion criteria, with 9 included in the meta-analysis. Children born with a cleft appear to have similar psychological outcomes compared to normative controls when using the strengths and difficulties questionnaire. There are some minor differences between self-report and parent report, with parents generally reporting that their child with a cleft has increased emotional, conduct, and hyperactivity problems. The small differences between the study cohort and control cohorts are unlikely to imply any differences on a clinical level., Conclusions: Overall psychological outcomes appear to be similar between children born with a cleft and the nonaffected population, however, some symptoms such as anxiety and depression appear higher in children with cleft lip and/or palate., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: A longitudinal cohort study was established to investigate the well-being of children born with cleft lip and/or palate (CL/P) during the COVID-19 pandemic, in Victoria, Australia., Materials and Methods: The Royal Children's Hospital cleft service database was used to identify children aged between 4 and 17 years old born with an isolated CL/P. Families of eligible children who consented to participate were asked to complete the Strengths and Difficulties Questionnaire (SDQ) between October and December 2020 and again 6-month later. SDQ results from typically developing Australian children during the COVID-19 pandemic were utilized from a previously published study., Results: 63 parents completed the baseline questionnaire, with 44 completing the 6-month follow-up. For participants at baseline, the mean age was 8.9 years, with 55% male. All outcome domains of the SDQ improved between baseline and timepoint 2, with the difference in total difficulties scores being statistically significant, indicating a reduction in total difficulties at timepoint 2, associated with the easing of COVID-19 restrictions. When compared with the Australian population during the COVID-19 pandemic, Victorian children born with CL/P had lower SDQ scores for all difficulties outcome domains, with statistically significant results for conduct problems, hyperactivity, peer problems and total difficulties, indicating fewer difficulties for children born with CL/P., Conclusions: Children born with CL/P experienced fewer difficulties when compared with the typically developing Australian population during the COVID-19 pandemic. The level of restrictions imposed because of the pandemic also had little influence on the well-being of these children., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To investigate if preschool children differ to school age children with mild traumatic brain injury (TBI) with respect to injury causes, clinical presentation, and medical management., Design: A secondary analysis of a dataset from a large, prospective and multisite cohort study on TBI in children aged 0-18 years, the Australian Paediatric Head Injury Rules Study., Setting: Nine pediatric emergency departments (ED) and 1 combined adult and pediatric ED located across Australia and New Zealand., Participants: 7080 preschool aged children (2-5 years) were compared with 5251 school-age children (6-12 years) with mild TBI (N= (N=12,331) MAIN OUTCOME MEASURES: Clinical report form on medical symptoms, injury causes, and management., Results: Preschool children were less likely to be injured with a projectile than school age children (P<.001). Preschool children presented with less: loss of consciousness (P<.001), vomiting (P<.001), drowsiness (P=.002), and headache (P<.001), and more irritability and agitation (P=.003), than school-age children in the acute period after mild TBI. Preschool children were less likely to have neuroimaging of any kind (P<.001) or to be admitted for observation than school age children (P<.001)., Conclusions: Our large prospective study has demonstrated that preschool children with mild TBI experience a different acute symptom profile to older children. There are significant clinical implications with symptoms post-TBI used in medical management to aid decisions on neuroimaging and post-acute intervention., (Copyright © 2023 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Acquired brain injury (ABI) occurs commonly in young children. Despite this, the psychosocial implications of ABI in young children are not established, with little understood about the impacts on self-perception and self-esteem. In this study we investigated self-perception, self-esteem and behaviour of children with early ABI. Children with an ABI ( n  = 47) before six years were compared to 17 typically developing controls (TDCs) matched on demographics. Children were aged 6-12 years and completed the Harter Self-Perception Profile. One parent completed the Child Behavior Checklist. No differences for self-perception and self-esteem were found between the groups. Parents of children with an early ABI reported more internalizing and externalizing behaviours. Children with more externalizing behaviour and social skill problems had more negative self-perceptions. Interaction effects were seen between socioeconomic status (SES) and child self-perception and behaviour. Specifically, children from families of higher SES had a more positive perception of their appearance and children from lower SES backgrounds had more externalizing behaviours and social problems. The study suggests that the relationship between ABI and self-perception and self-esteem is complicated and that children with behavioural problems have lowered feelings of competence. SES has an important role in self-perception and behavioural outcomes.

Objective: Children with concussion frequently present to emergency departments (EDs). There is limited understanding of the differences in signs, symptoms, and epidemiology of concussion based on patient age. Here, the authors set out to assess the association between age and acute concussion presentations., Methods: The authors conducted a multicenter prospective observational study of head injuries at 10 EDs in Australia and New Zealand. They identified children aged 5 to < 18 years, presenting with a Glasgow Coma Scale score of 13-15, presenting < 24 hours postinjury, with no abnormalities on CT if performed, and one or more signs or symptoms of concussion. They extracted demographic, injury-related, and signs and symptoms information and stratified it by age group (5-8, 9-12, 13 to < 18 years)., Results: Of 8857 children aged 5 to < 18 years, 4709 patients met the defined concussion criteria (5-8 years, n = 1546; 9-12 years, n = 1617; 13 to < 18 years, n = 1546). The mean age of the cohort was 10.9 years, and approximately 70% of the patients were male. Sport-related concussion accounted for 43.7% of concussions overall, increasing from 19.1% to 48.9% to 63.0% in the 5-8, 9-12, and 13 to < 18 years age groups. The most common acute symptoms postinjury were headache (64.6%), disorientation (36.2%), amnesia (30.0%), and vomiting (27.2%). Vomiting decreased with increasing age and was observed in 41.7% of the 5-8 years group, 24.7% of the 9-12 years group, and 15.4% of the 13 to < 18 years group, whereas reported loss of consciousness (LOC) increased with increasing age, occurring in 9.6% in the 5-8 years group, 21.0% in the 9-12 years group, 36.7% in the 13 to < 18 years group, and 22.4% in the entire study cohort. Headache, amnesia, and disorientation followed the latter trajectory. Symptom profiles were broadly similar between males and females., Conclusions: Concussions presenting to EDs were more sports-related as age increased. Signs and symptoms differed markedly across age groups, with vomiting decreasing and headache, LOC, amnesia, and disorientation increasing with increasing age.

Background: Sexual dysfunction (SD) is reported in neurological conditions similar to Friedreich ataxia (FRDA). Anecdotally individuals with FRDA report SD including erectile dysfunction and altered genital sensation. Understanding SD in FRDA assists health professionals identify SD issues and improve healthcare for individuals with FRDA., Objective: To quantify if, and to what extent, people with FRDA experience challenges with sexual function and intimate relationships as a result of primary (genital function), secondary (physical) and tertiary (psychosocial) dysfunction., Methods: An online purpose designed anonymous questionnaire explored SD and intimate relationships. Invitations to participate were sent to individuals with FRDA aged 18 years and over on the Ataxia UK and Friedreich Ataxia Research Alliance databases. Date collection occurred between January and July, 2017., Results: One-hundred-and-seventy-nine adults with FRDA participated, of which 107 reported current or previous sexual activity. Erectile dysfunction was reported in 57% (20/35) of males, inadequate vaginal lubrication interfering with sexual responsiveness was reported in 57.7% (26/45) of females, and 47% (51/107) reported reduced genital sensation. In addition, 88% (94/107) reported problems moving their body during sexual activity and 73% (78/107) reported reduced confidence about their sexuality due to FRDA. A significant negative relationship was shown between younger age of disease onset and SD., Conclusion: This study confirmed FRDA impacts sexual functioning, sexual satisfaction and the capacity to form intimate relationships. Understanding the nature and extent of SD is critical to developing interventions and recommendations designed to enhance sexual function, sexuality, and intimate relationships for individuals with FRDA.

Objective: To investigate long-term intellectual function following a traumatic brain injury (TBI) in early childhood and to identify the contribution of injury and environment to outcome., Participants: Fifty children younger than 3 years with a diagnosis of accidental TBI were recruited through a pediatric hospital emergency department. Children with TBI were compared with a group (n = 33) of typically developing children (TDC) matched on demographics., Design: Longitudinal, single-site, case-control study., Measures: Children completed intellectual assessments (IQ) at 4.5 to 5.5 years of age (average 3.5 years after TBI) and at 7.5 to 9 years of age (average 6.5 years after TBI). Information on injury and environmental predictors of outcome was collected., Results: IQ scores for all groups were in the average range; however, children with TBI of any severity had lower scores than TDC at both time points. There was some suggestion of children with TBI achieving lower verbal IQ scores over time than TDC. IQ scores were predicted by family environment, not injury characteristics., Conclusions: A TBI in early childhood is associated with lower IQ scores that persist several years postinjury. Socioeconomic status is an influential factor on IQ at 6.5 years post-TBI., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Extreme weather events, including hurricanes, have considerable biological, ecological, and anthropogenic impacts. Hurricane Irene caused substantial economic damage when it hit the Mid-Atlantic Bight (MAB) off of the eastern United States in August of 2011. The MAB is highly stratified during the summer when a strong thermocline separates warm, surface water from deep, cold water, and this oceanographic phenomenon makes modeling hurricane strength difficult. Loggerhead sea turtles ( Caretta caretta ) forage in the MAB primarily during the stratified season and their dive behavior to the bottom allows them to experience the oceanographic conditions of the entire water column., Methods: In this study, we analyzed the movements and dive behavior of juvenile and adult-sized loggerhead sea turtles ( n  = 18) that were foraging in the MAB as Hurricane Irene moved through the region. The satellite tags deployed on these turtles transmitted location data and dive behavior as well as sea surface temperature (SST) and temperature-depth profiles during this time., Results: Behavioral and environmental shifts were observed during and after the hurricane compared to conditions before the storm. During the hurricane, most of the turtles ( n  = 15) moved north of their pre-storm foraging grounds. Following the storm, some turtles left their established foraging sites ( n =  8) moving south by 7.3-135.0 km, and for the others that remained ( n  = 10), 12% of the observed dives were longer (0.54-1.11 h) than dives observed before the storm. The in situ data collected by the turtle-borne tags captured the cooling of the SST (Mean difference = 4.47°C) and the deepening of the thermocline relative to the pre-storm conditions., Conclusions: Some of the loggerhead behavior observed relative to a passing hurricane differed from the regular pattern of seasonal movement expected for turtles that forage in the MAB. These data documented the shifts in sea turtle behavior and distribution during an ecosystem-level perturbation and the recorded in situ data demonstrated that loggerheads observe environmental changes to the entire water column, including during extreme weather events., Competing Interests: Competing interestsThe author(s) declare(s) that they have no competing interests., (© The Author(s) 2020.)

Objective: The validated Predicting Abusive Head Trauma (PredAHT) clinical prediction tool calculates the probability of abusive head trauma (AHT) in children <3 years of age who have sustained intracranial injuries (ICIs) identified on neuroimaging, based on combinations of six clinical features: head/neck bruising, seizures, apnoea, rib fracture, long bone fracture and retinal haemorrhages. PredAHT version 2 enables a probability calculation when information regarding any of the six features is absent. We aimed to externally validate PredAHT-2 in an Australian/New Zealand population., Methods: This is a secondary analysis of a prospective multicentre study of paediatric head injuries conducted between April 2011 and November 2014. We extracted data on patients with possible AHT at five tertiary paediatric centres and included all children <3 years of age admitted to hospital who had sustained ICI identified on neuroimaging. We assigned cases as positive for AHT, negative for AHT or having indeterminate outcome following multidisciplinary review. The estimated probability of AHT for each case was calculated using PredAHT-2, blinded to outcome. Tool performance measures were calculated, with 95% CIs., Results: Of 87 ICI cases, 27 (31%) were positive for AHT; 45 (52%) were negative for AHT and 15 (17%) had indeterminate outcome. Using a probability cut-off of 50%, excluding indeterminate cases, PredAHT-2 had a sensitivity of 74% (95% CI 54% t o89%) and a specificity of 87% (95% CI 73% to 95%) for AHT. Positive predictive value was 77% (95% CI 56% to 91%), negative predictive value was 85% (95% CI 71% to 94%) and the area under the curve was 0.80 (95% CI 0.68 to 0.92)., Conclusion: PredAHT-2 demonstrated reasonably high point sensitivity and specificity when externally validated in an Australian/New Zealand population. Performance was similar to that in the original validation study., Trial Registration Number: ACTRN12614000463673., Competing Interests: Competing interests: AMK and LEC are part of the team that derived and validated the Predicting Abusive Head Trauma tool. However, all data collection and analyses were undertaken independently of either of these authors., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: The National Emergency X-Radiography Utilisation Study II (NEXUS II) clinical decision rule (CDR) can be used to optimise the use of CT in children with head trauma. We set out to externally validate this CDR in a large cohort., Methods: We performed a prospective observational study of patients aged <18 years presenting with head trauma of any severity to 10 Australian/New Zealand EDs. In a planned secondary analysis, we assessed the accuracy of the NEXUS II CDR (with 95% CI) to detect clinically important intracranial injury (ICI). We also assessed clinician accuracy without the rule., Results: Of 20 137 total patients, we excluded 28 with suspected penetrating injury. Median age was 4.2 years. CTs were obtained in ED for 1962 (9.8%), of whom 377 (19.2%) had ICI as defined by NEXUS II. 74 (19.6% of ICI) patients underwent neurosurgery.Sensitivity for ICI based on the NEXUS II CDR was 379/383 (99.0 (95% CI 97.3% to 99.7%)) and specificity was 9320/19 726 (47.2% (95% CI 46.5% to 47.9%)) for the total cohort. Sensitivity in the CT-only cohort was similar. Of the 18 022 children without CT in ED, 49.4% had at least one NEXUS II risk criterion. Sensitivity for ICI by the clinicians without the rule was 377/377 (100.0% (95% CI 99.0% to 100.0%)) and specificity was 18 147/19 732 (92.0% (95% CI 91.6% to 92.3%))., Conclusions: NEXUS II had high sensitivity, similar to the derivation study. However, approximately half of unimaged patients were positive for NEXUS II risk criteria; this may result in an increased CT rate in a setting with high clinician accuracy., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: To prospectively compare the proportion of traumatic brain injuries (TBIs) that would be classified as mild by applying different published definitions of mild TBI to a large prospectively collected dataset, and to examine the variability in the proportions included by various definitions., Design: Prospective observational study., Setting: Hospital emergency departments., Participants: Children (N=11,907) aged 3 to 16 years (mean age, 8.2±3.9y). Of the participants, 3868 (32.5%) were girls, and 7374 (61.9%) of the TBIs were the result of a fall. Median Glasgow Coma Scale score was 15., Main Outcome Measures: We applied 17 different definitions of mild TBI, identified through a published systematic review, to children aged 3 to 16 years. Adjustments and clarifications were made to some definitions. The number and percentage identified for each definition is presented., Results: Adjustments had to be made to the 17 definitions to apply to the dataset: none in 7, minor to substantial in 10. The percentage classified as mild TBI across definitions varied from 7.1% (n=841) to 98.7% (n=11,756) and varied by age group., Conclusions: When applying the 17 definitions of mild TBI to a large prospective multicenter dataset of TBI, there was wide variability in the number of cases classified. Clinicians and researchers need to be aware of this variability when examining literature concerning children with mild TBI., (Copyright © 2018 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Cetorhinus maximus aggregations recorded during extensive aerial survey efforts off the north-eastern United States between 1980 and 2013 included aggregations centring on sightings with group sizes of at least 30 individuals. These aggregations occurred in summer and autumn months and included aggregation sizes of up to 1398 individuals, the largest aggregation ever reported for this species. The aggregations were associated with sea surface temperatures of 13-24° C and chlorophyll-a concentrations of 0·4-2·6 mg m -3 and during one aggregation, a high abundance of zooplankton prey was present. Photogrammetric tools allowed for the estimation of total body lengths ranging between 4 and 8 m. Characterization of these events provides new insight into the potential biological function of large aggregations in this species., (© 2018 The Fisheries Society of the British Isles.)

There are significant merits to a comprehensive cognitive assessment, but they are also time-consuming, costly, and susceptible to practice effects and may not detect change in the context of medical interventions or minor brain disruptions. Brief computer-based assessments focused on "fluid" cognitive domains (e.g., information-processing skills), which are vulnerable to disruption as a result of a brain injury, may provide an alternative assessment option. This study sought to: (a) examine the utility of a well-established, adult-based computerized tool, CogSport for Kids (CogState), for evaluating information-processing skills in children and adolescents; and (b) to report normative data for healthy children and adolescents. The study was a cross-sectional, community-based observational study of typically developing children aged 9 to 17 years old (N = 832). Participants completed the CogSport for Kids test battery, which includes six brief computerized tasks that assess cognitive functions including processing speed, attention, and working memory. Results showed an improvement with age for response speed and accuracy. The greatest change occurred between 9 and 12 years with performance stabilizing at 15 years. This brief screening tool is appropriate for clinical and research use in children aged 9 years and older and may be used to track cognitive development from childhood into adulthood and to identify children who deviate from normal expectations.

Child traumatic brain injury (TBI) is a major cause of disability in early life. Unlike in adults, a TBI in childhood causes an insult to a brain that is developing, potentially affecting future brain maturation, neural connectivity, and the acquisition of new skills. This review considers how such early brain insult may impact children's functional abilities, and how these processes may link with differential patterns of recovery across infancy, childhood, and adolescence. We also review evidence for cognitive impairment across a range of domains (IQ, attention, processing, memory executive function) and common educational, behavioral, and social consequences associated with child TBI. While impairments in all of these domains have been reported, in fact outcomes from child TBI are surprisingly varied and difficult to predict. To assist in understanding what may contribute to outcomes, we discuss predictive factors (injury severity, child and environment status) and research reporting on their individual and combined effect on recovery. The identification of such outcome predicators has led to an emerging literature in the area of intervention and rehabilitation that we also summarize. Finally, it concludes with discussion of the future direction of pediatric TBI research., (© 2015 Elsevier B.V. All rights reserved.)

Objective: To investigate language outcomes of TBI in preschool-aged children. Competent early language skills are pivotal for the future development of literacy skills. While previous research has reported that traumatic brain injury (TBI) places children at risk of language impairments, the majority of these studies have been conducted with school-aged children., Setting: Royal Children's Hospital, Melbourne, Australia., Participants: Children aged 4 to 6 years who had sustained a mild (N = 19) or moderate/severe (N = 16) TBI prior to 3 years of age and a control group (N = 20) of typically developing children matched for age, gender, and socioeconomic status., Main Measures: The Wechsler Preschool and Primary School Scale of Intelligence, Third Edition, measured Verbal IQ. The Clinical Evaluation of Language Fundamentals-Preschool version and the Bus Story Test measured language skills., Results: More severely injured children displayed greater impairments in verbal intellectual abilities and language skills compared with children with mild TBI and uninjured children. Children with mild TBI performed similarly to children in the control group., Conclusion: Language appears vulnerable to TBI and should be investigated as a matter of course in clinical assessments of TBI recovery.

Dispute has surrounded the issue of whether the relationship between anosmia and executive dysfunction in traumatic brain injury (TBI) may be artefactual due to poor ascertainment. Three groups matched for age, gender, education, Full Scale IQ, and the Wechsler Working Memory Index and showing adequate symptom validity were compared: 30 anosmic TBIs (TBI-A) matched for posttraumatic amnesia (PTA) and working memory functioning with 36 nonanosmic TBIs (TBI-NA) and 51 controls. The groups performed the FAS test, the Animal Fluency test, the Stroop Neurological Screening Test (SNST), the Wisconsin Card Sorting Test-64 (WCST-64) and the Trail Making Test (TMT-B) as well as tests of emotional functioning and return to work outcome. After adjusting for the covariates (i.e., gender; Wechsler Test of Adult Reading, WTAR; and years of education), a significant effect was found for items successfully completed on the SNST, the FAS task, the Animal Fluency task, and the WCST-64 categories completed. After adjusting for the covariates, a significant difference was found for number of errors on the SNST and for the number and type of errors on TMT-B. The two groups did not differ in terms of their affective functioning (i.e., Beck Depression Inventory or Beck Anxiety Inventory), or in terms of their outcome with regard to return to work. The findings support the notion that the TBI-A group demonstrated considerably weaker performance on executive tasks than did the nonanosmic TBIs. These patients were not, however, more prone to an error-prone pattern of performance, and, if anything, their executive deficit was more likely attributable to a reduced productivity of response.

Traumatic brain injury (TBI) is a common cause of disability in childhood. While the outcomes of TBI sustained in school years has been heavily researched, very little is known about the impact of TBI in infants and young children. The aim of this study was to investigate the impact of TBI on executive function (EF) in children who sustained a TBI before 3 years of age. A group of 55 children, 19 with a mild TBI, 16 children with a moderate-severe TBI, and 20 uninjured comparison children participated. The EF of children aged 3 to 6 years were compared using child-based measures of attentional control and information processing. Parents completed questionnaires rating their child's EF. Severity groups differed on the child-based EF measure of attentional control with children with TBI performing below the control group. There were no significant group differences for information processing or parent-rated EF. It appears that children who sustain a TBI before the age of 3 years display impairments in some areas of attentional control 3-4 years postinjury. The findings fit with the existing EF literature for older children.

Background: A significant number of children under 3 years sustain a head injury every year. Despite this few studies have provided detailed information about these injuries., Methods: A retrospective review of the medical files all children aged 0-3 years who attended a paediatric emergency department for treatment over a 2-year period., Results: Children aged 0-6 months had the highest rate of moderate head injury. Children under 12 months were at the greatest risk of injury. Falls were the most common cause of injury including falls from caregiver's arms., Conclusions: Children under 12 months are at significant risk of head injury, many of these injuries could be prevented by increased parental supervision or improved home safety., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Objective: The intellectual, behavioral, and social function of children who sustained traumatic brain injury (TBI) before 3 years of age were compared with a group of uninjured children. The role of injury and environmental factors in recovery was examined., Methods: A group of 53 children who sustained a TBI before 3 years of age (20 mild and 33 moderate/severe) and 27 uninjured children (control group) were assessed on an IQ measure and parent measures of behavior and social skills. Children were aged 4 to 6 years and were an average of 40 months since sustaining their injury., Results: There were no demographic differences between the groups. Although all group scores were in the average range, children with moderate/severe TBI performed significantly below uninjured children on an IQ measure. No significant differences were found on parent behavior ratings, although effect sizes between groups were medium to large. No differences were found for social skills. All outcomes were significantly influenced by environmental but not injury factors., Conclusions: Moderate/severe TBI at an early age appears to be associated with lowered intellectual function and possibly behavior problems. A child's environment influences cognitive and behavior function after TBI.

Advances in neuroscience have added to the understanding of social functioning which has become an increasing area of focus in the psychology and neuropsychology literature. Given importance of appropriate social functioning to everyday interactions, as well as psychological well-being, accurately identifying and documenting such functions constitute a critical undertaking for both researchers and clinicians in psychology and related health professions. This review aimed to identify available social function assessment tools for children and adolescents using a comprehensive search method. Eighty-six measures were identified. Information on the assessment tools including the theoretical model they are based on, age range, sample used in development, and psychometric information are described. Results will aid researchers, psychologists and other health professionals in the selection of an appropriate tool to assess social function., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Objectives: Head injuries (HI) in children are common and even mild HI can lead to ongoing cognitive and behavioural changes. We set out to determine the causes of sport-related HI in school-age children presenting to a large urban ED as a basis for future interventions., Method: Identification and medical record review of all sport-related HI in children aged 6-16 years at a tertiary children's hospital ED in Victoria, Australia, over a 1 year period. Information was collected on demographics, injury variables and radiology findings. HI were classified as mild, moderate and severe based on GCS and radiography reports., Results: Over 12 months there were 406 HI in school-age children. Seventy per cent were male. A large number of HI (129; 33%) were related to sports. Of these, most were classified as mild and 13% were classified as moderate or severe. Among a range of sports, Australian Rules football was associated with more than 30% of all HI attributable to a sport and recreation cause. Equestrian activities were the main cause of moderate HI., Conclusion: The present study identified sports as a major cause of HI in the Victorian paediatric emergency setting with Australian Rules football the most commonly involved sport. Further prevention initiatives should consider targeting Australian Rules football and equestrian activities.

We have found that incubation in lactose solutions (0.75 M) of yeast culture Saccharomyces cerevisiae sensitive to dehydration damage increased the stability of the cells during dehydration. Simultaneously with this increase in viability, a decrease in plasma membrane permeability during rehydration was seen. Using Fourier transform infrared spectroscopy to measure lipid phase transitions, we observed that the lactose treatment depressed the membrane phospholipid phase transition temperature in a sensitive culture of dry yeast. As a result, it leads to the decrease in the damages of molecular organization of membranes during rehydration of dry yeast cells, thus reducing leakage from the cells.

The Center for Biostabilization at UC Davis is attempting to stabilize mammalian cells in the dry state. We review here some of the lessons from nature that we have been applying to this enterprise, including the use of trehalose, a disaccharide found at high concentrations in many anhydrobiotic organisms, to stabilize biological structures, both in vitro and in vivo. Trehalose has useful properties for this purpose and in at least in one case-human blood platelets-introducing this sugar may be sufficient to achieve useful stabilization. Nucleated cells, however, are stabilized by trehalose only during the initial stages of dehydration. Introduction of a stress protein obtained from an anhydrobiotic organism, Artemia, improves the stability markedly, both during the dehydration event and following rehydration. Thus, it appears that the stabilization will require multiple adaptations, many of which we propose to apply from studies on anhydrobiosis.

Thermal stress in living cells produces multiple changes that ultimately affect membrane structure and function. We report that two members of the family of small heat-shock proteins (sHsp) (alpha-crystallin and Synechocystis HSP17) have stabilizing effects on model membranes formed of synthetic and cyanobacterial lipids. In anionic membranes of dimyristoylphosphatidylglycerol and dimyristoylphosphatidylserine, both HSP17 and alpha-crystallin strongly stabilize the liquid-crystalline state. Evidence from infrared spectroscopy indicates that lipid/sHsp interactions are mediated by the polar headgroup region and that the proteins strongly affect the hydrophobic core. In membranes composed of the nonbilayer lipid dielaidoylphosphatidylethanolamine, both HSP17 and alpha-crystallin inhibit the formation of inverted hexagonal structure and stabilize the bilayer liquid-crystalline state, suggesting that sHsps can modulate membrane lipid polymorphism. In membranes composed of monogalactosyldiacylglycerol and phosphatidylglycerol (both enriched with unsaturated fatty acids) isolated from Synechocystis thylakoids, HSP17 and alpha-crystallin increase the molecular order in the fluid-like state. The data show that the nature of sHsp/membrane interactions depends on the lipid composition and extent of lipid unsaturation, and that sHsps can regulate membrane fluidity. We infer from these results that the association between sHsps and membranes may constitute a general mechanism that preserves membrane integrity during thermal fluctuations.

A review of the role of sugars in anhydrobiosis is presented.

Polar fish, cold hardy plants, and overwintering insects produce antifreeze proteins (AFPs), which lower the freezing point of solutions noncolligatively and inhibit ice crystal growth. Fish AFPs have been shown to stabilize membranes and cells in vitro during hypothermic storage, probably by interacting with the plasma membrane, but the mechanism of this stabilization has not been clear. We show here that during chilling to nonfreezing temperatures the alpha-helical AFP type I from polar fish inhibits leakage across model membranes containing an unsaturated chloroplast galactolipid. The mechanism involves binding of the AFP to the bilayer, which increases the phase transition temperature of the membranes and alters the molecular packing of the acyl chains. We suggest that this change in acyl chain packing results in the reduced membrane permeability. The data suggest a hydrophobic interaction between the peptide and the bilayer. Further, we suggest that the expression of AFP type I in transgenic plants may be significant for thermal adaptation of chilling-sensitive plants.

Membrane fluidity and overall protein secondary structure of human erythrocytes were studied in situ using Fourier transform infrared spectroscopy (FTIR). Erythrocyte membranes were found to have weakly cooperative phase transitions at 14 degrees C and at 34 degrees C, which were tentatively assigned to the melting of the inner membrane leaflet and the sphingolipid rich outer leaflet, respectively. Cholesterol depletion by methyl-beta-cyclodextrin (MbetaCD) resulted in a large increase in the cooperativity of these transitions, and led to the appearance of another phospholipid transition at 25 degrees C. Multiple, sharp membrane phase transitions were observed after 5 days cold storage (4 degrees C ), which indicated phase separation of the membrane lipids. Using fluorescence microscopy, it was determined that the lipid probe 1,1'-dioctadecyl-3,3,3',3-tetramethyl-indocarbocyanine perchlorate (dil-C18) remained homogeneously distributed in the erythrocyte membrane during cold storage, suggesting that lipid domains were below the resolution limit of the microscope. Using thin layer chromatography, changes in the membrane lipid composition were detected during cold storage. By contrast, assessment of the amide-II band with FTIR showed that the overall protein secondary structure of haemoglobin was stable during cold storage.

This essay is a review of the various biophysical and biochemical events that make up the factors responsible for platelet cold-induced activation. It describes the formation of large membrane domains composed of raft aggregates that occur during chilling and storage. It also presents strong evidence that platelet membranes undergo lateral phase separation during prolonged storage in the cold and suggests that raft aggregation and lateral phase separation are key events which must be obviated to stabilize platelets and store them either in the frozen or in the dry state., (Copyright 2001 Elsevier Science (USA).)

This essay is an introduction to a series of papers arising from a symposium on stabilization of cells in the dry state. Nearly all of these investigations have utilized the sugar trehalose as a stabilizing molecule. Over the past two decades a myth has grown up about special properties of trehalose for stabilization of biomaterials. We review many of such uses here and show that under ideal conditions for drying and storage trehalose has few, if any, special properties. However, under suboptimal conditions trehalose has some distinct advantages and thus may remain the preferred excipient. We review the available mechanisms for introducing trehalose into the cytoplasm of living cells as an introduction to the papers that follow., (Copyright 2001 Elsevier Science (USA).)

The (1)H- and (13)C-NMR spectra of antifreeze glycoprotein fractions 1-5 from Antarctic cod have been assigned, and the dynamics have been measured using (13)C relaxation at two temperatures. The chemical shifts and absence of non-sequential (1)H-(1)H NOEs are inconsistent with a folded, compact structure. (13)C relaxation measurements show that the protein has no significant long-range order, and that the local correlation times are adequately described by a random coil model. Hydroxyl protons of the sugar residues were observed at low temperature, and the presence of exchange-mediated ROEs to the sugar indicate extensive hydration. The conformational properties of AFGP1-5 are compared with those of the previously examined 14-mer analog AFGP8, which contains proline residues in place of some alanine residues (Lane, A. N., L. M. Hays, R. E. Feeney, L. M. Crowe, and J. H. Crowe. 1998. Protein Sci. 7:1555-1563). The infrared (IR) spectra of AFGP8 and AFGP1-5 in the amide I region are quite different. The presence of a wide distribution of backbone torsion angles in AFGP1-5 leads to a rich spectrum of frequencies in the IR spectrum, as interconversion among conformational states is slow on the IR frequency time scale. However, these transitions are fast on the NMR chemical shift time scales. The restricted motions for AFGP8 may imply a narrower distribution of possible o, psi angles, as is observed in the IR spectrum. This has significance for attempts to quantify secondary structures of proteins by IR in the presence of extensive loops.

In previous studies, it has been suggested that chilling induced activation of human platelets is related to a lipid phase transition seen in membrane lipids. Those studies showed a single, surprisingly cooperative transition in human platelets, as determined by Fourier transform infrared (FTIR) spectroscopy, findings that are confirmed here with calorimetric measurements. Such transitions have now been studied in membrane fractions obtained from the platelets and it is reported that all fractions and purified phospholipids show similar transitions. In order to obtain these data it was necessary to develop means for separating these fractions. Therefore, a novel method for isolation and separation of dense tubular system (DTS) and plasma membranes in human platelets is described here. Lipid analysis showed that phosphatidylcholine (PC) and phosphatidylethanolamine (PE) were the dominant phospholipids in both fractions, whereas cholesterol and sphingomyelin (SM) were predominantly located in the plasma membranes. Thermotropic phase transitions in the two membrane fractions, determined by differential scanning calorimetry (DSC) and FTIR spectroscopy were found to occur at about 15 degrees C, similar to the Tm of intact human platelets. These data are discussed in relation to the role of the DTS and plasma membranes in the cold-induced activation of human platelets.

In previous studies we have proposed that the well-known chilling-induced activation of human blood platelets can be ascribed at least in part to a thermotropic phase transition in membrane lipids. The evidence that this is the case is reviewed and amplified in this review, followed by an examination of the available physical data concerning phase transitions in lipid mixtures that mimic the mixture found in platelet membranes. Assuming complete mixing at all temperatures and equal contributions of the members of the mixture to the phase transition, the lipid mixture found in platelets should give values for Tm ranging from about 1 degrees C to about 16 degrees C, depending on the isomers present in the mixture. (The former value is not in agreement with the observed Tm, but the latter is in excellent agreement.) However, examination of the phase diagram for a binary pair of lipids found in platelet membranes shows that ideal mixing almost certainly does not occur; instead of a linear phase diagram, a convex one was obtained. This shape for the phase diagram, which would displace Tm to an unexpectedly elevated temperature, is in agreement with previously published phase diagrams for mixtures of this type. The prediction, based on thermodynamic properties of lipids found in the platelets, is that Tm will be displaced upward in more complex mixtures of the composition found in platelets, a prediction that requires experimental testing., (Copyright 1999 Academic Press.)

The effect of the carbohydrates trehalose, glucose, and hydroxyethyl starch (HES) on the motional properties of the phosphate headgroup of freeze-dried dipalmitoylphosphatidylcholine (DPPC) liposomes was studied by means of 31P NMR, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). The results show that trehalose, which is a strong glass former (Tg = 115 degreesC), elevates the onset of the lipid headgroup rotations and preserves some rotational mobility of the phosphate headgroups after cooling from the liquid-crystalline state. Glucose (Tg = 30 degreesC), a very effective depressant of the phase transition temperature of freeze-dried DPPC, markedly elevates the initiation of the temperature of headgroup rotations. On the other hand, the monosaccharide does not preserve the headgroup disordering when cooled from the liquid-crystalline state. These effects are consistent with formation of hydrogen bonds between the OH groups of the sugar and the polar headgroups of DPPC. They show, however, that hydrogen bonding is not sufficient for preservation of the dynamic properties of freeze-dried DPPC. HES, although a very good glass former (Tg > 110 degreesC), does not depress the phase transition temperature and affects only slightly the rotational properties of freeze-dried DPPC. This lack of effect of HES is associated with the absence of direct interactions with the lipid phosphates, as evidenced by the FTIR results. These data show that vitrification of the additive is not sufficient to affect the dynamic properties of dried DPPC.

The 1H and 13C NMR spectra of a 14-residue antifreeze glycopeptide from Antarctic cod (Tetramatomnus borchgrevinki) containing two proline residues have been assigned. 13C NMR relaxation experiments indicate motional anisotropy of the peptide, with a tumbling time in water at 5 degrees C of 3-4 ns. The relaxation data and lack of long-range NOEs are consistent with a linear peptide undergoing significant segmental motion. However, extreme values of some coupling constants and strong sequential NOEs indicate regions of local order, which are most evident at the two ATPA subsequences. Similar spectroscopic properties were observed in the 16-residue analogue containing an Arg-Ala dipeptide added to the C-terminus. Molecular modeling also showed no evidence of long-range order, but the two ATPA subsequences were relatively well determined by the experimental data. These motifs were quite distinct from helical structures or beta turns commonly found in proteins, but rather resemble sections of an extended polyproline helix. Thus, the NMR data provide a description of the local order, which is of relevance to the mechanism of action of the antifreeze activity of the antifreeze glycopeptides as well as their ability to protect cells during hypothermic storage.

The glycosylated hydroquinone arbutin (4-hydroxyphenyl-beta-D-glucopyranoside) is abundant in certain resurrection plants, which can survive almost complete dehydration for prolonged periods. Little is known about the role of arbutin in vivo, but it is thought to contribute toward survival of the plants in the dry state. We have investigated the interactions of arbutin with model membranes under conditions of high and low hydration, as well as the possible participation of arbutin in carbohydrate glasses formed at low water contents. Retention of a trapped soluble marker inside large unilamellar vesicles and fusion of vesicles was monitored by fluorescence spectroscopy. Effects of arbutin on glass-transition temperatures and hydrated membrane phase-transition temperatures were measured by differential scanning calorimetry. The possible insertion of arbutin into membrane bilayers was estimated by following arbutin auto-fluorescence. Evidence is presented that arbutin does not change the glass-transition temperature of a sucrose/trehalose glass, but that arbutin does interact with hydrated membranes by insertion of the phenol moiety into the lipid bilayer. This interaction causes increased membrane leakage during air-drying by a mechanism other than vesicle-vesicle fusion. Implications of these effects on the dehydrated plant cells, as well as possible methods of obviating the damage, are discussed., (Copyright 1998 Elsevier Science B.V.)

The expression of the high-affinity trehalose-H+ symport was investigated in various Saccharomyces cerevisiae strains and culture conditions. Previous kinetic studies of trehalose transport in yeast have revealed the existence of at least two different uptake mechanisms: a high-affinity trehalose-H+ symport activity repressed by glucose, and a constitutive low-affinity transport activity, a putative facilitated diffusion process. Exogenously added trehalose was not an inducer of the high-affinity transport activity, and a correlation between trehalose and maltose uptake by yeast cells was found. Our results indicate that the maltose-H+ symporters encoded by MAL11, MAL21, and MAL41 are not responsible for the trehalose transport activity. The analysis of both trehalose and maltose transport activities in wild-type and in laboratory strains with defined MAL genes showed that the trehalose-H+ symporter was under control of MAL regulatory genes. Our results also suggest that the recently characterized AGT1 gene of S. cerevisiae may encode the high-affinity trehalose-H+ symporter. During diauxic growth on glucose the transport activity was low during the first exponential phase of growth, increased as glucose was exhausted from the medium, and decreased again as the cells reached the late stationary phase. This pattern was coincident with that of the intracellular levels of trehalose. The strong correlation between these two parameters may be of physiological significance during adaptation of yeast cells to stress conditions.

Numerous organisms are capable of surviving more or less complete dehydration. A common feature in their biochemistry is that they accumulate large amounts of disaccharides, the most common of which are sucrose and trehalose. Over the past 20 years, we have provided evidence that these sugars stabilize membranes and proteins in the dry state, most likely by hydrogen bonding to polar residues in the dry macromolecular assemblages. This direct interaction results in maintenance of dry proteins and membranes in a physical state similar to that seen in the presence of excess water. An alternative viewpoint has been proposed, based on the fact that both sucrose and trehalose form glasses in the dry state. It has been suggested that glass formation (vitrification) is in itself sufficient to stabilize dry biomaterials. In this review we present evidence that, although vitrification is indeed required, it is not in itself sufficient. Instead, both direct interaction and vitrification are required. Special properties have often been claimed for trehalose in this regard. In fact, trehalose has been shown by many workers to be remarkably (and sometimes uniquely) effective in stabilizing dry or frozen biomolecules, cells, and tissues. Others have not observed any such special properties. We review evidence here showing that trehalose has a remarkably high glass-transition temperature (Tg). It is not anomalous in this regard because it lies at the end of a continuum of sugars with increasing Tg. However, it is unusual in that addition of small amounts of water does not depress Tg, as in other sugars. Instead, a dihydrate crystal of trehalose forms, thereby shielding the remaining glassy trehalose from effects of the added water. Thus under less than ideal conditions such as high humidity and temperature, trehalose does indeed have special properties, which may explain the stability and longevity of anhydrobiotes that contain it. Further, it makes this sugar useful in stabilization of biomolecules of use in human welfare.

R. P. Goodrich and co-workers (1989, U.S. Patent 4,874,690; 1992, Proc. Natl. Acad. Sci. USA 89,967-971) have reported that red blood cells can be preserved in the dry state by addition of mixtures of hydroxyethyl starch (HES) and glucose. More recently, Spieles and co-workers (1996, Cryo-Lett. 17, 43-52) found that HES alone is insufficient to preserve the dry cells and concluded on this basis that the studies of Goodrich et al. were incorrect. In the present paper we revisit that suggestion, using liposomes as a model to study effects of HES and glucose on membrane stability. In previous studies we and others have established that liposomes can be stabilized in the dry state if they are dried in the presence of disaccharides. Monosaccharides have not been effective. Measurements of effects of glucose on phase transitions in the dry lipids and vibrational frequency of the phosphate headgroup suggest that glucose shows an interaction with dry egg phosphatidylcholine similar to that seen with disaccharides. Nevertheless, glucose does not inhibit fusion in liposomes during drying, and it does not prevent leakage. Hydroxyethyl starch, which has a very high glass transition (Tg), inhibits fusion in the dry liposomes, but it does not depress the liquid crystalline to gel phase transition temperature (Tm) in the dry phospholipids, does not cause a shift in the phosphate vibration indicative of hydrogen bonding of the sugar to the phosphate, and does not stop leakage of trapped carboxyfluorescein. However, if glucose is added to the HES-containing samples, the liposomes are stabilized, so long as the samples are maintained below the Tg of the mixture. If they are heated above that Tg they fuse and leak their contents. We conclude that both glass formation and depression of Tm in the dry lipids are required. The role of glass formation in stabilization during drying of liposomes appears to be inhibition of fusion.

Simple sugars, especially disaccharides, stabilize biomaterials of various composition during air-drying or freeze-drying. We and others have provided evidence that direct interaction, an interaction that we believe is essential for the stabilization, between the sugar and polar groups in, for example, proteins and phospholipids occurs in the dry state. Some researchers, however, have suggested that the ability of the sugar to form a glass is the only requirement for stabilization. More recently, we have shown that both glass formation and direct interaction of the sugar and headgroup are often required for stabilization. In the present study, we present a state diagram for trehalose glass and suggest that the efficacy of this sugar for stabilization may be related to its higher glass transition temperatures at all water contents. We also show that trehalose and trehalose:liposome preparations form trehalose dihydrate as well as trehalose glass when rehydrated with water vapor. Formation of the dihydrate sequesters water, which might otherwise participate in lowering the glass transition temperature to below ambient. Because samples remain in the glassy state at ambient temperatures, viscosity is high and fusion between liposomes is prevented.

Using Fourier transform infrared spectroscopy (FTIR), we have determined the phase transition temperature (Tm) of lipids in intact human platelets and have shown that it occurs between 15 and 18 degrees C, the temperature at which cold activation of platelets has previously been reported (Zucker and Borrelli, 1954, Blood, 28:602-608; White and Krivit, 1967, Blood, 30:625-635). The temperature at which the platelets pass through Tm is highly correlated with initial platelet shape change. However, shape change continues after the cells have passed through the phase transition. Cold-induced activation has previously prevented long-term storage of platelets at 4 degrees C. Antifreeze glycoproteins (AFGPs) isolated from polar fishes previously have been used to prevent ice crystal growth during freezing of tissues as well as leakage of solutes from liposomes as they were chilled through their Tm. We sought to determine if these AFGPs were able to stabilize platelets for long-term storage at 4 degrees C. Incubating platelets with antifreeze glycoproteins during long-term storage and rapid rewarming to 37 degrees C abrogated granule secretion associated with cold activation in a dose-dependent manner. This work suggests that AFGPs may be a possible solute for use in long-term low temperature storage of platelets.

Arbutin is a glycosylated hydroquinone found at high concentrations in certain plants capable of surviving extreme and sustained dehydration. In this paper, we examine a potential role of this molecule in anhydrobiosis. We have studied its effects on the physical properties of phospholipids and on preservation of liposomes during drying. Arbutin depresses the gel to liquid crystalline phase transition temperature of dry phospholipids, as measured by differential scanning calorimetry, with a pattern similar to that seen in phospholipids dried with the disaccharide trehalose. Unlike trehalose, however, arbutin does not protect dry liposomes from leaking their contents. Also, using Fourier transform infrared spectroscopy, we found an increase in the vibrational frequency of the phosphate asymmetric stretch in partially hydrated phospholipids in the presence of arbutin. Trehalose, by contrast, depresses the frequency of the phosphate in dry phospholipids, indicating that the modes of interaction of trehalose and arbutin with the bilayer are different. Previously, we have shown that phospholipases can be active in liposomes with surprisingly low water contents. Based on the structural similarity of arbutin to a known inhibitor of phospholipase A2 (PLA2), it appeared possible that arbutin might serve as an inhibitor of phospholipases. Liposomes of varying composition were lyophilized in the presence and absence of phospholipases. When the liposomes were partially rehydrated at 76% relative humidity, arbutin inhibited PLA2, but did not inhibit phospholipases B or C. Accumulation of enzyme product in the liposome membranes was measured by analytical thin layer chromatography, and was taken as a measure of enzyme activity. Arbutin did not inhibit any of the enzymes in the presence of excess water. Based on these data, hypotheses are presented concerning the mechanism of PLA2 inhibition by arbutin in the mostly dehydrated state.

Antifreeze glycoproteins (AFGPs), found in the blood of polar fish at concentrations as high as 35 g/liter, are known to prevent ice crystal growth and depress the freezing temperature of the blood. Previously, Rubinsky et al. [Rubinsky, B., Mattioli, M., Arav, A., Barboni, B. & Fletcher, G. L. (1992) Am. J. Physiol. 262, R542-R545] provided evidence that AFGPs block ion fluxes across membranes during cooling, an effect that they ascribed to interactions with ion channels. We investigated the effects of AFGPs on the leakage of a trapped marker from liposomes during chilling. As these liposomes are cooled through the transition temperature, they leak approximately 50% of their contents. Addition of less than 1 mg/ml of AFGP prevents up to 100% of this leakage, both during chilling and warming through the phase transition. This is a general effect that we show here applies to liposomes composed of phospholipids with transition temperatures ranging from 12 degrees C to 41 degrees C. Because these results were obtained with liposomes composed of phospholipids alone, we conclude that the stabilizing effects of AFGPs on intact cells during chilling reported by Rubinsky et al. may be due to a nonspecific effect on the lipid components of native membranes. There are other proteins that prevent leakage, but only under specialized conditions. For instance, antifreeze proteins, bovine serum albumin, and ovomucoid all either have no effect or actually induce leakage. Following precipitation with acetone, all three proteins inhibited leakage, although not to the extent seen with AFGPs. Alternatively, there are proteins such as ovotransferrin that have no effect on leakage, either before or after acetone precipitation.