Comparison of quantitative and visual detection of new focal bone lesions.

A comparison is made between the sensitivity of detection of focal abnormalities in radionuclide bone images by visual examination and by using simple quantification. The quantitative method calculates the ratio of radiopharmaceutical uptake in a region of interest drawn around a lesion to that in an area of normal bone. Quantification is found to be far more sensitive than visual examination in detecting focal metastases. The use of "baseline" images improved the precision of quantitation of rib lesions, but appeared not to alter the sensitivity of visual detection. This method of quantification is therefore limited more by the inability of observers to notice suspicious areas to which it should be applied than by inaccuracies inherent in the method itself. Further work should concentrate more on image enhancement than on improving quantitative techniques.

Radionuclide image minification can compensate for coarse digitization: concise communication.

Although it is common practice to digitize radionuclide images onto the finest matrix available, their low count densities and poor spatial resolution suggest that quite large pixels should be adequate. Observers find these large pixels visually obtrusive, but minification of the image can reduce this effect. Experiments reported here have investigated how minification (achieved by increasing viewing distance) affects the perceived quality of images digitized onto different sized matrices. Observers' subjective preference for different pixel sizes was measured at various viewing distances using clinical bone images as test patterns. An objective measure of image quality was made by comparing the detectability of computer-generated focal areas of increased activity both in simple noisy backgrounds and in clinical bone images. The results show that a 128 X 128 matrix is adequate when the image is 8 cm2 and is viewed from 1 and 2 m. A finer matrix failed to produce better results.

Selecting compounds for focused screening using linear discriminant analysis and artificial neural networks.

Linear discriminant analysis and a committee of neural networks have been applied to recognise compounds that act at biological targets belonging to a specific gene family, protein kinases. The MDDR database was used to provide compounds targeted against this family and sets of randomly selected molecules. BCUT parameters were employed as input descriptors that encode structural properties and information relevant to ligand-receptor interactions. The technique was applied to purchasing compounds from external suppliers. These compounds achieved hit rates on a par with those achieved using known actives for related targets when tested for the ability to inhibit kinases at a single concentration. This approach is intended as one of a series of filters in the selection of screening candidates, compound purchases and the application of synthetic priorities to combinatorial libraries.

Reproducibility of gamma camera data.

The increasing use of quantification in the interpretation of nuclear medicine images requires a knowledge of the errors associated with the estimation of the activity in a volume of interest from the recorded count rate data. Using sources of known cross-sectional area from 1 to 25 cm2, errors caused by variations in the count rate, day of measurement, source position in the camera field of view, and source size are evaluated. The effect of source depth in tissue-equivalent (TE) medium on the reproducibility of the data is also investigated. For a given source size at a known depth, variations in camera response lead to an error (SD) of a least 6% that increases as either the source size or the depth of the source in TE medium is increased. Failure to estimate accurately the true depth of the organ can also be a major source of error. The use of two conventional types of flood correction technique ('count-skipping' and matrix division) is found to increase the error only in the case of the smallest source.

Effectiveness of bicycle helmets in preventing head injury in children: case-control study.

OBJECTIVE: To examine the risk of injury to the head and the effect of wearing helmets in bicycle accidents among children. DESIGN: Case-control study by questionnaire completed by the children and their carers. SETTING: Two large children's hospitals in Brisbane, Australia. SUBJECT: 445 children presenting with bicycle related injuries during 15 April 1991 to 30 June 1992. The cases comprised 102 children who had sustained injury to the upper head including the skull, forehead and scalp or loss of consciousness. The controls were 278 cyclists presenting with injuries other than to the head or face. A further 65 children with injuries to the face were considered as an extra comparison group. MAIN OUTCOME MEASURES: Cause and type of injury, wearing of helmet. RESULTS: Most children (230) were injured after losing control and falling from their bicycle. Only 31 had contact with another moving vehicle. Children with head injury were significantly more likely to have made contact with a moving vehicle than control children (19 (19%) v 12 (4%), P < 0.001). Head injuries were more likely to occur on paved surfaces than on grass, gravel, or dirt. Wearing a helmet reduced the risk of head injury by 63% (95% confidence interval 34% to 80%) and of loss of consciousness by 86% (62% to 95%). CONCLUSIONS: The risk of head injury in bicycle accidents is reduced among children wearing a helmet. Current helmet design maximises protection in the type of accident most commonly occurring in this study. Legislation enforcing helmet use among children should be considered.

Increasing incidence of childhood immersion injury in Brisbane.

The incidence of childhood immersion injury in a defined population is reported. The data were drawn from this Hospital's Child Injury Surveillance programme and cover the period July 1, 1984 to June 30, 1985. The overall rate of immersion injury was 26.8 per year per 100 000 children at risk and the rate for fresh-water immersions was 25.3. The magnitude of this public health problem is revealed by an annual fresh-water immersion rate of 70.2 per 100 000 at risk for the critical 0 to four years' age group. Eighty per cent of all immersions occurred in swimming-pools and the rate of pool immersion is three times that reported in the Brisbane Drowning Study (1971-1975). Eighty per cent of immersions in back yard pools were potentially avoidable by the provision of an effective safety barrier. Only 25% of the families that were involved could be described as being familiar with their pool.

Modelling of solvent positions around polar groups in proteins.

Previous analysis of the distribution of experimental solvent molecule positions around amino acid side chains showed that distinct clustering occurred close to polar or charged atoms in proteins. We have used those data to predict likely solvent positions around proteins not used in our initial analysis. We envisage that this algorithm, AQUARIUS, will be useful for finding solvent positions in electron density maps generated by protein crystallography and as useful starting positions for solvent molecules in computer simulation studies of macromolecules.

Childhood drowning and near-drowning in Brisbane: the contribution of domestic pools.

OBJECTIVE: To describe the epidemiology of domestic swimming pool drowning and near-drowning in Brisbane and to examine the efficacy of a broad range of preventive options, including pool fences. DESIGN: A prospective, hospital-based, injury surveillance system to describe the epidemiology of drowning and near-drowning and a community survey to describe pool fencing. SETTING: The surveillance questionnaire was completed at presentation in the Emergency Department by the parent, nurse and doctor. Personal interviews in households that were randomly selected by means of a stratified sampling scheme provided the pool fencing description. PARTICIPANTS: All 139 children suffering from an immersion injury resulting in presentation at a hospital in the catchment area of The Mater Children's Hospital were included. There were 204 households with a swimming pool in the 1024 households interviewed in the community survey. RESULTS: The 100 domestic pool drownings and near-drownings were equivalent to 15.5 incidents per year per 100,000 children aged 0-13 years and 64.9 per year per 100,000 for the critical 1-3 years age group. Of 72 children who gained unintended access to a domestic pool, 88.9% were less than 3 years of age and 52.8% were less than 2 years. All 10 of the children who drowned and five who were severely brain damaged (age range, 12-32 months) were in this group. The risk of a drowning or near-drowning involving unintended access to an unfenced pool is 3.76 times higher than the risk associated with a fenced pool (95% confidence limits for relative risk: 2.14, 6.62). CONCLUSIONS: Pool fences are an effective method of preventing child drownings and near-drownings. This effectiveness can be further improved if compliance with gate closure can be enhanced. This should be emphasised in health promotion accompanying the introduction of universal pool fencing.

Eucalyptus oil poisoning in childhood: 41 cases in south-east Queensland.

Forty-two cases of oral eucalyptus oil poisoning in children under 14 years of age were identified in a defined population between 1 July 1984 and 30 June 1991, and 41 were subjected to retrospective case note analysis. Thirty-three children (80%) were entirely asymptomatic. This group included all of the four children reported to have ingested more than 30 mL of eucalyptus oil. Only two of the remaining children had symptoms or clinical signs on presentation to hospital. No child required advanced life-support. There was no correlation between the amount of eucalyptus oil taken and the presence of symptoms. If the estimated volume ingested is large, or symptoms are evident, on presentation at hospital gastrointestinal decontamination should lead to a good outcome with few clinical problems. Eucalyptus oil may be a less toxic compound than has previously been believed.

Childhood poisoning in Queensland: an analysis of presentation and admission rates.

OBJECTIVE: To determine the presentation rates for paediatric poisoning by ingestion and the determinants of hospital admission. METHODOLOGY: Cross-sectional survey using an injury surveillance database from emergency departments in South Brisbane, Mackay and Mt Isa, Queensland, from January 1998 to December 1999. There were 1516 children aged 0-14 years who presented following ingestional poisoning. RESULTS: The presentation rates for poisoning were 690, 40 and 67 per 100000 population aged 0-4, 5-9 and 10-14 years, respectively. The admission rates to hospital for poisoning were 144, 14 and 22 per 100000 population aged 0-4, 5-9 and 10-14 years, respectively. Although presentation rates for poisoning were higher in the rural centres the admission rates were disproportionately high for the 0-4 years age group. The agents most frequently ingested were paracetamol, Dimetapp, rodenticides and essential oils. CONCLUSION: There is a need to design and implement interventions aimed at reducing poison exposures and unnecessary hospital admissions in the 0-4 years age group.

Child injury in Brisbane South 1985-91: implications for future injury surveillance.

Specific childhood injury types are ranked by occurrence rate for mortality, hospital admission and emergency department attendance. Cases are drawn from the resident population of Brisbane South, 0-13 years of age, for the period 1 July 1985 to 30 June 1991. A total of 47,244 injuries, 7056 admissions and 99 deaths were analysed. The overall mortality rate was 12.6/100,000 per year (95% confidence interval (CI), 10.2-15.3), the overall admission rate was 911/100,000 per year (95% CI, 890-932) and the overall hospital attendance rate was 6013/100,000 per year (95% CI, 5958-6067). A fall was the most frequent injury mechanism for admissions and 65% of attendances involved injury in the child's own home. The surveillance data establish regional variation for childhood injury risk within Australia and identify an unexplained downward trend in head injury that requires further investigation. The future development of injury surveillance in Australia requires simplified coding which can be integrated into new computerized patient management information systems.

Prognostic factors and long-term outcomes for children who have nearly drowned.

OBJECTIVE: To find predictors of outcome and to describe the long term outcome for children who require mechanical ventilation after nearly drowning. PATIENTS AND SETTING: From 1981 to 1989, all children who underwent ventilation in the Intensive Care Unit of the Master Children's Hospital, Brisbane, after an immersion. Children who died within 24 hours were excluded. Of 57 children eligible for entry, 18 died after 24 hours. DESIGN: Retrospective study of hospital records and prospective assessment of neurodevelopmental outcome. Thirty-eight families of survivors were contacted by questionnaire and 25 children of these families were examined. Follow-up was between 0.8 and 9.6 years after immersion. RESULTS: All children who had a motor response to pain in the hospital's emergency department survived without sequelae. Thirty-one children were in cardiac arrest and, of these, 17 died, six survived with severe spastic quadriplegia and eight are ambulant. Of those ambulant, four have motor coordination difficulties and three have learning difficulties. Children in cardiac arrest who had a delay of more than 20 minutes between rescue and arrival at hospital were more likely to die or sustain severe spastic quadriplegia. No child survived if more than 25 minutes of advanced resuscitation was required after they had been warmed. CONCLUSIONS: Children with a motor response to pain seem to have a good prognosis. However, we could not predict which children in cardiac arrest would die or survive either severely impaired or ambulant. All children in cardiac arrest should receive aggressive resuscitation for at least 25 minutes after being warmed; they have a better prognosis if advanced resuscitation is started less than 20 minutes after rescue. Children who survive a cardiac arrest without spastic quadriplegia warrant long term surveillance as they may have coordination and learning difficulties.

Linguistic status subsequent to childhood immersion injury.

The linguistic abilities of two groups of children who had been involved in immersion incidents are reported--one group at 12 months after the immersion incident (n = 25), and the second group at five years after the immersion incident (n = 9). The performances of the two experimental groups on standardized language tests were compared with the performances of appropriate control groups that were matched for age, sex and socioeconomic status. The speech and language skills of the 12-months post-immersion group and the matched control group were assessed by means of the sequenced inventory of communication development. Subjects who were assessed 12 months after the immersion injury scored significantly lower results than did control subjects on receptive and expressive language ages that were calculated as percentages of the chronological age. No differences in language scores were evident between the subjects who were at five years after the immersion incident and their control subjects as assessed by the test of language development--primary. The language abilities of the victims of an immersion incident were correlated with their neurological status at presentation to hospital. The results suggest a need to monitor the linguistic development of all children who present initially in a coma after an immersion incident. The need for a longitudinal study of the linguistic abilities of these children is indicated.

Single dose trimethoprim-sulphamethoxazole treatment of symptomatic urinary infection.

Seventy-nine children with symptoms of urinary tract infections were randomly allocated to treatment with a single dose or a 7-day course of trimethoprim-sulphamethoxazole. Of the 42 patients (39 girls, 3 boys) who fulfilled the criteria for the trial, 23 were given a single-dose regimen and 19 of them a 7-day regimen. Both groups of patients had sterile urine cultures 2 days after starting treatment. Eight patients had underlying structural renal abnormalities (n = 3, single-dose regimen; n = 5, 7-day regimen). One patient in the single dose group had a recurrence of infection on day 7. These results show that single dose trimethoprim-sulphamethoxazole is as effective as the conventional 7-day course in children with symptomatic urinary tract infection. Further investigation of the renal tract is necessary regardless of the fact that the infection has been eradicated by single-dose treatment.

Children and bicycles: what is really happening? Studies of fatal and non-fatal bicycle injury.

OBJECTIVES: The objectives of the study were to ascertain the causes of accidents, injuries, and deaths in children who ride bicycles. Fatality and injury rates were also studied in order to compare with other studies. METHODS: Two studies of children were undertaken in children aged less than 15 years. In the first (retrospective fatality study), children who died as a result of a bicycle incident during the period 1981-92 were reviewed. In the second (prospective injury study) data were obtained prospectively between April 1991 and June 1992 about children who were injured while riding a bicycle and treated at a public hospital in Brisbane. RESULTS: Study 1: fatality rates for boys were twice those for girls. The rate was highest for boys of 14 years in the metropolitan area at 6.23/100,000. All deaths involved vehicles, and the majority involved head injury or multiple injuries including head injury. Study 2: similar numbers of children were injured at onroad and off-road locations. Faculty riding was described by the rider or caregiver as the cause in 62.5% of cases. The most common time of injury was between 3 and 6 pm on both school and non-school days. Only 5.5% of all incidents involved a moving vehicle. CONCLUSIONS: Bicycle riding by children is a common cause of injury, particularly for boys. Equal numbers of injuries occurred on the road as at other locations. Faulty riding caused most accidents. Injury prevention for bicycle riders should involve not only compulsory wearing of helmets, but should also include education and training about safe riding habits, separation of motorised vehicles from bicycles, modified helmet design to incorporate facial protection, and improved handlebar design.

Bicycle incidents in children--abdominal trauma and handlebars.

OBJECTIVES: To investigate the frequency and causes of bicycle related abdominal injuries in children and to examine the pattern of presentation. DESIGN: The study was a prospective study of bicycle related injury in children less than 15 years of age presenting to two paediatric hospitals (15 April-30 June 1992) and three general hospitals (1 August 1991-30 June 1992). RESULTS: In a series of 813 children, 41 sustained non-penetrating abdominal trauma due to a bicycle incident. In 21 cases, handlebar trauma was responsible. Ten of these children suffered life-threatening intra-abdominal injury. Handlebars with no plastic or foam covering of the metal ends were involved in all ten cases. In several of these cases, presentation to hospital was delayed and in others confirmation of the extent of injury took up to 48 hours. The length of hospital stay for those with significant intra-abdominal organ damage ranged from two to 156 days. CONCLUSIONS: Intra-abdominal trauma must be considered when dealing with children who are victims of bicycle trauma. Impact with handlebars may have occurred and some form of padded protection of handlebar ends is recommended unless their design can be suitably modified.

The Bioinformatics Template Library--generic components for biocomputing.

MOTIVATION: The efficiency of bioinformatics programmers can be greatly increased through the provision of ready-made software components that can be rapidly combined, with additional bespoke components where necessary, to create finished programs. The new standard for C++ includes an efficient and easy to use library of generic algorithms and data-structures, designed to facilitate low-level component programming. The extension of this library to include functionality that is specifically useful in compute-intensive tasks in bioinformatics and molecular modelling could provide an effective standard for the design of reusable software components within the biocomputing community. RESULTS: A novel application of generic programming techniques in the form of a library of C++ components called the Bioinformatics Template Library (BTL) is presented. This library will facilitate the rapid development of efficient programs by providing efficient code for many algorithms and data-structures that are commonly used in biocomputing, in a generic form that allows them to be flexibly combined with application specific object-oriented class libraries. AVAILABILITY: The BTL is available free of charge from our web site http://www.cryst.bbk.ac.uk/~classlib/ and the EMBL file server http://www.embl-ebi.ac.uk/FTP/index.html

Arylsulphonyl hydroxamic acids: potent and selective matrix metalloproteinase inhibitors.

A series of novel matrix metalloproteinase inhibitors is described in which selectivity between MMP and 'sheddase' activity has been achieved and which demonstrate potent in vivo activity in models of arthritis and cancer.