An investigation of cyclist passing distances in the Australian Capital Territory.

In Australia, cycling hospitalisations are increasing and the cycling participation rate is stagnating. In an effort to improve cyclist safety, many Australian jurisdictions have mandated a minimum passing distance that vehicles much provide when overtaking a cyclist on a public road, including the Australian Capital Territory (ACT). However, it is not currently clear how vehicle-cyclist passing distances are affected by various parameters such as the road environment, the vehicles involved, or the speed limit. This naturalistic bicycle riding study examined data from passing distance measurement devices that were installed on the bicycles of volunteer cyclists who ride in the ACT, to explore how passing distances and compliance with the minimum passing distance were affected by several parameters. Over a four-week period, 23 volunteer cyclist participants undertook 465 journeys and travelled 6531 km over a total period of 271 h. There were 10,959 passing events identified on roads zoned greater than 60 km/h (high speed roads) of which 1349 (12.3 %) were non-compliant. On roads zoned 60 km/h or less (low speed roads) there were 5517 passing events of which 153 (2.8 %) were non-compliant. Regression analyses showed that differences in passing distance and non-compliance with the minimum passing distance were associated with road classification, bike lane presence, and speed limit. The results were mixed but, in general, passing distances were greater on roads with a lower (hierarchy) classification and on motorways as well as on roads with higher speed limits. An exception to this was roads with a speed limit of 50 km/h where passing distances were closer in comparison to roads with a speed limit of 60 km/h. Bike lanes were generally associated with an increase in passing distance except on 'trunk' classified roads, where a bike lane resulted in closer passing events. This suggests that on trunk roads, which are assumed to carry large amounts of traffic, bike lanes may be insufficient to offer protection to cyclists and additional measures may be required.

Shape Analysis of the Patellar Bone Surface and Cutting Plane for Knee Replacement Surgery.

Geometry of the patella (kneecap) remains poorly understood yet is highly relevant to performing the correct patellar cut to reduce pain and to improve function and satisfaction after knee replacement surgery. Although studies routinely refer to "parallel to the anterior surface" and "the patellar horizon," a quantitative definition of these is lacking and significant variability exists between observers for this irregularly-shaped bone. A 2D-3D shape analysis technique was developed to determine the optimal device configuration for contacting the patellar surface. Axial and sagittal pseudo-X-rays were created from 18 computed tomography (CT) scans of cadaveric knees. Four expert surgeons reviewed three repetitions of the X-rays in randomized order, marking their desired cut plane and their estimate of the anterior surface. These 2D results were related back to the 3D model to create the desired plane. There was considerable variability in perceptions, with intra- and intersurgeon repeatability (standard deviations) ranging from 1.3° to 2.4°. The best configuration of contact points to achieve the desired cutting plane was three pegs centred on the patellar surface, two superior and one inferior, forming a 16 mm equilateral triangle. This configuration achieved predicted cut planes within 1° of the surgeon ranges on all 18 patellae. Implementing this, as was done in a subsequent prototype surgical device, should help improve the success and satisfaction of knee replacement surgery.

Eosinophils promote allergic disease of the lung by regulating CD4(+) Th2 lymphocyte function.

Eosinophils are primarily thought of as terminal effectors of allergic responses and of parasite elimination. However, limited studies suggest a more discrete immunomodulatory role for this leukocyte during these inflammatory responses. In this investigation, we highlight the potential of eosinophils to act as APCs and thus modulators of allergic responses by influencing Th2 cell function. In response to Ag provocation of the allergic lung, eosinophils rapidly trafficked to sites of Ag deposition (airways lumen) and presentation (lung-associated lymph nodes and T cell-rich paracortical zones). Eosinophils from the allergic lung expressed class II MHC peptides, T cell costimulatory molecules (CD80 and CD86), and rapidly internalized and processed Ag that was sampled from within the airway lumen. Ag-loaded eosinophils promoted the production of IL-4, IL-5, and IL-13 in cocultures with in vitro-polarized Th2 cells and induced IL-5 production in a dose-dependent manner from Ag-specific CD4(+) T cells isolated from allergic mice. In addition, Ag-loaded eosinophils primed for Th2 cell-driven allergic disease of the lung when transferred to naive mice. Thus, eosinophils have the potential to not only activate Th2 cells to release disease-modulating cytokines but also to assist in priming the immune system for allergic responses. This investigation highlights the potential of eosinophils to not only act as terminal effector cells but also to actively modulate allergic inflammation by amplifying Th2 cell responses.

A polymorphic marker for the human cathepsin B gene.

Human cathepsin B (CTSB) is a proteolytic enzyme implicated in tumor invasion and metastasis. We describe a PCR-based polymorphic marker for this gene comprising two amplimers differing in length by 19 consecutive nucleotides in intron 7, near the exon 8 splice acceptor site, identifying two gene alleles (A and B). Allele frequencies were 0.614 for A and 0.386 for the B allele, with an observed heterozygosity of 0.457 in a cohort of 70 non-related Australian blood donors. One additional nucleotide difference was also revealed through sequencing. The human CTSB gene is located on chromosome 8 and the alleles described here can potentially be used as markers in linkage and association studies of cancers and other diseases.

Complications of treatment of paediatric malignancies.

Advances in surgical techniques, radiotherapy and chemotherapy have led to improved survival for children with solid tumours and leukaemia. However, the treatment has also resulted in increased side effects both in the short and long term. This article outlines the complications which may arise as a result of treatment under the headings of surgery; chemotherapy; radiotherapy; organ specific complications; infection and graft-v-host disease.

A case of Acro-renal-mandibular syndrome in an 18 week male fetus.

An 18 week male fetus is described with Acro-renal-mandibular syndrome. This third reported case of the syndrome is the first known male case and extends the phenotypic spectrum that characterizes the condition.

Risk assessment of renal cortical scarring with urinary tract infection by clinical features and ultrasonography.

AIMS: To address some of the issues in the ongoing debate over the optimal diagnostic imaging following childhood urinary tract infection (UTI), by determining the risk of missing renal cortical scarring which would be detected on a technetium-99m dimercaptosuccinic acid (DMSA) gold standard if ultrasound alone were used, factoring for clinical features (upper or lower tract), UTI recurrence, and age group (infants, preschool, or school age). METHODS: Details of UTI clinical features and recurrence were recorded for 990 children with a proven UTI, and their DMSA and ultrasound results were compared for each kidney. RESULTS: The risks of missing DMSA scarring varied between 0.4% (school age children with solitary lower tract UTI) and 11.1% (infants with recurrent upper tract UTI). CONCLUSIONS: UTI clinical features are important in assessing the need for DMSA imaging. Current UK imaging guidelines are endorsed, although preschool children with solitary lower tract UTI remain a controversial group and more attention needs to focused on children with recurrent UTI.

99Tcm-HMPAO leucocyte labelling in orofacial granulomatosis and gastrointestinal Crohn's disease in childhood and early adulthood.

Orofacial granulomatosis is a granulomatous inflammatory disorder, affecting the soft tissues of the face and mouth. The predominant feature is disfiguring lip swelling. Patients with this condition may be exhibiting a Type IV hypersensitivity reaction to dietary or environmental allergens, or these may be the orofacial manifestations of underlying gastrointestinal Crohn's disease. The results of 99Tcm-HMPAO leucocyte labelling of the gastrointestinal tract in 14 patients with orofacial granulomatosis and 15 patients with known gastrointestinal Crohn's disease are presented, indicating that this is a useful and non-invasive screening test for the identification of gastrointestinal Crohn's disease in paediatric and young adult patients presenting with orofacial granulomatosis.

The role of nuclear medicine in children.

Nuclear medicine studies have an important role to play in the diagnosis, treatment and follow-up of several paediatric conditions. This article highlights this role and indicates areas of potential growth.

An unusual hernia: congenital pericardial effusion associated with liver herniation into the pericardial sac.

To our knowledge there have been only two previous cases of diaphragmatic hernia into the pericardium diagnosed antenatally. We describe our pre- and post-natal radiological findings in such a case, although the final diagnosis eluded us until after delivery.

A review of renal scarring in children.

It is now widely accepted that children with a proven urinary tract infection should undergo some form of diagnostic imaging to assess the presence of, or the potential to develop, renal scarring. The type of investigation which should be performed is controversial. Some centres still perform intravenous urography, others rely on ultrasound alone, while others believe that a 99Tc(m)-dimercaptosuccinic acid (99Tc(m)-DMSA) scan is essential. This review discusses the advantages and disadvantages of these techniques by drawing from the extensive literature currently available. The consensus view is that a DMSA scan is the most sensitive method of detecting renal scarring and of highlighting the kidney at risk of developing scarring. It is hoped that wider early use of DMSA scintigraphy will lead to a fall in the number of children who develop end-stage renal disease.

Total hip replacement for coxarthrosis secondary to congenital dysplasia and dislocation of the hip. Long-term results.

Between 1970 and 1982, sixty-six total hip replacements were performed with cement, without bone-grafting, in fifty-three patients who had congenital dysplasia and dislocation of the hip. Preoperatively, the patients had had Crowe type-II, III, or IV subluxation. Current information was available for fifty-nine hips in forty-six patients after an average duration of follow-up of sixteen years (range, ten to twenty-one years). The average age of the patients at the time of the operation was fifty-three years (range, twenty-three to seventy-three years). The average Harris hip score at the most recent examination was 92 points (range, 61 to 100 points). Eight hips were revised. The reason for the revision was infection in two hips, fracture of the femoral stem in two, and loosening of the acetabular component in four. The rate of revision for aseptic loosening, therefore, was 10 per cent (six hips). In the unrevised hips for which radiographs were available, the rate of radiographic loosening of the femoral component was 5 per cent (two hips) and that of the acetabular component was 32 per cent (twelve hips). We did not find a relationship between the amount of horizontal or vertical displacement of the center of the femoral head and the rate of loosening. Kaplan-Meier survivorship analysis with revision as the end point predicted a rate of survival of 85 per cent (95 per cent confidence interval, 75 to 95 per cent) at fifteen years. With radiographic loosening as the end point, the predicted rate of survival was 68 per cent (95 per cent confidence interval, 54 to 81 per cent) at fifteen years. We concluded that, for patients who have Crowe type-II, III, or IV congenital dysplasia of the hip, good long-term results can be obtained with insertion of a femoral stem with cement. The high rate of loosening of cemented acetabular components is a concern.

Symptomatic cortical irregularities of the distal femur simulating malignancy.

We reviewed the records and radiographs of seven children who presented with knee pain, local tenderness over the medial femoral condyle, and radiological irregularity of the distal medial metaphysis of the femur suggestive of malignancy. In the five patients who had biopsies, histological changes were consistent with musculotendinous avulsion, and the dissection of ten cadavers confirmed the site to be the insertion of part of the adductor magnus. The recognition of this lesion and knowledge of its benign nature may avoid unnecessary anxiety and needless biopsy.

The value of ultrasound in the child with an acute urinary tract infection.

OBJECTIVE: To assess the value of an ultrasound examination in children with a proven urinary tract infection. PATIENTS AND METHODS: The results of renal ultrasound and 99mTc-dimercapto-succinic acid (DMSA) studies were compared in 112 children with a first documented symptomatic Escherichia coli urinary tract infection. RESULTS: Ultrasound was particularly effective in detecting the presence of obstruction, renal swelling and parenchymal change consistent with acute pyelonephritis. However, ultrasound failed to detect half of the kidneys with photon deficient areas on 99mTc DMSA scan and was unreliable in detecting the presence of scarring. CONCLUSION: An ultrasound examination alone should not be relied on in the child with an acute urinary tract infection.

Total hip arthroplasty with cement in patients who are less than fifty years old. A sixteen to twenty-two-year follow-up study.

Eighty-nine Charnley total hip arthroplasties were performed with cement, by a single surgeon, in sixty-seven patients who were less than fifty years old at the time of the procedure. The follow-up period ranged from sixteen to twenty-two years (average, eighteen years). The most recent evaluation consisted of a clinical and a radiographic examination for forty-six patients (fifty-eight hips), a telephone interview and a review of the most recent radiographs for eleven patients (sixteen hips), and a telephone interview only for six patients (ten hips). Four patients (five hips) were lost to follow-up. Eleven (13 per cent) of the eighty-four hips that were followed were revised because of aseptic loosening of the acetabular implant, and two hips (2 per cent) were revised because of aseptic failure (loosening or fracture) of the femoral component. When the number of hips that were revised was combined with the number of hips in which there was radiographic evidence of failure, the rate of loosening of the acetabular component was 50 per cent (forty-two hips) and the rate of failure of the femoral component was 8 per cent (seven hips). Three hips had recurrent dislocations after the operation; none of the three was revised. One patient (two hips) had Grade-III heterotopic ossification according to the system of Brooker et al.; no other patient had more than Grade-II heterotopic ossification. Nine hips had a trochanteric non-union without migration of the trochanter.(ABSTRACT TRUNCATED AT 250 WORDS)

Case report: extravasation of lipiodol--a complication of dacryocystography.

We describe the occurrence of a significant cosmetic blemish in the cheek of a young girl which was caused by extravasation of 'Lipiodol' from the lacrimal canaliculus. Erythema and swelling lasted for several months before resolving completely. This complication has not been reported in the English literature before.

Areas of contact and extent of gaps with implantation of oversized acetabular components in total hip arthroplasty.

Contact between porous surfaces and bone and initial stable fixation of the implant to bone are required to achieve bone ingrowth into prosthetic devices. To avoid the potential problems associated with screws that are often used to obtain initial stability of uncemented acetabular components, oversizing of the component has been recommended. This study investigated the shape of the reamed surface compared with the acetabular reamers used, the areas of bone implant contact obtained with oversizing, and the extent of polar area gaps created by this surgical technique. In embalmed hemipelvises, using surface fitting algorithms, the average departure from sphericity, of the reamed acetabular surface, was 0.56 mm. Using Pressensor film, extensive peripheral cup contact but minimal polar area contact was demonstrated when oversizing the components. In addition, large polar area gaps were demonstrated using polyvinylsiloxane epoxy molds. This study confirms the potential concerns associated with oversizing the acetabular component in relation to the reamed acetabular surface. Although excellent peripheral contact was obtained using this technique, polar area contact was demonstrated to be minimal or nonexistent, and large polar area gaps were observed. In addition, this study demonstrates that a precisely reamed surface can be obtained in the acetabulum when accurately sized reamers are used.