The application of subset correspondence analysis to address the problem of missing data in a study on asthma severity in childhood.

Non-response in cross-sectional data is not uncommon and requires careful handling during the analysis stage so as not to bias results. In this paper, we illustrate how subset correspondence analysis can be applied in order to manage the non-response while at the same time retaining all observed data. This variant of correspondence analysis was applied to a set of epidemiological data in which relationships between numerous environmental, genetic, behavioural and socio-economic factors and their association with asthma severity in children were explored. The application of subset correspondence analysis revealed interesting associations between the measured variables that otherwise may not have been exposed. Many of the associations found confirm established theories found in literature regarding factors that exacerbate childhood asthma. Moderate to severe asthma was found to be associated with needing neonatal care, male children, 8- to 9-year olds, exposure to tobacco smoke in vehicles and living in areas that suffer from extreme air pollution. Associations were found between mild persistent asthma and low birthweight, and being exposed to smoke in the home and living in a home with up to four people. The classification of probable asthma was associated with a group of variables that indicate low socio-economic status.

A survey of foot problems in juvenile idiopathic arthritis.

BACKGROUND: Evidence suggests that foot problems are common in juvenile idiopathic arthritis (JIA), with prevalence estimates over 90%. The aim of this survey was to describe foot-related impairment and disability associated with JIA and foot-care provision in patients managed under modern treatment paradigms, including disease-modifying anti-rheumatic drugs (DMARDs) and biologic therapies. METHODS: The Juvenile Arthritis Foot Disability Index (JAFI), Child Health Assessment Questionnaire (CHAQ), and pain visual analogue scale (VAS) were recorded in 30 consecutive established JIA patients attending routine outpatient clinics. Foot deformity score, active/limited joint counts, walking speed, double-support time (s) (DS) and step length symmetry index % (SI) were also measured. Foot-care provision in the preceding 12 months was determined from medical records. RESULTS: Sixty-three per cent of children reported some foot impairment, with a median (range) JAFI subscale score of 1 (0-3); 53% reported foot-related activity limitation, with a JAFI subscale score of 1 (0-4); and 60% reported participation restriction, with a JAFI subscale score of 1 (0-3). Other reported variables were CHAQ 0.38 (0-2), VAS pain 22 (0-79), foot deformity 6 (0-20), active joints 0 (0-7), limited joints 0 (0-31), walking speed 1.09 m/s (0.84-1.38 m/s), DS 0.22 s (0.08-0.26 s) and SI +/-4.0% (+/-0.2-+/-31.0%). A total of 23/30 medical records were reviewed and 15/23 children had received DMARDS, 8/23 biologic agents and 20/23 multiple intra-articular corticosteroid injections. Ten children received specialist podiatry care comprising footwear advice, orthotic therapy and silicone digital splints together with intrinsic muscle strengthening exercises. CONCLUSION: Despite frequent use of DMARD/biologic therapy and specialist podiatry-led foot care, foot-related impairment and disability persists in some children with JIA.

Infection with Ureaplasma urealyticum: is there a specific clinical and radiological course in the preterm infant?

BACKGROUND: Despite having mild early respiratory disease, many preterm babies develop chronic lung disease (CLD). Intrauterine infection with Ureaplasma urealyticum has been associated with preterm labour and CLD. OBJECTIVE: To test the hypothesis that infection with U urealyticum results in a specific clinical and radiological picture in the first 10 days of life. METHODS: Retrospective study of 60 ventilated babies < 30 weeks gestation, who had tracheal secretions tested for U urealyticum. Placental histology was reviewed by a paediatric pathologist for signs of chorioamnionitis. Chest radiographs were independently reviewed by two paediatric radiologists according to previously agreed criteria. All reviewers were blinded to the infection status of the babies. RESULTS: Twenty five babies were U urealyticum positive. These were more likely to experience chorioamnionitis (p = 0.004), premature rupture of membranes (p = 0.01), and spontaneous vaginal delivery (p = 0.09). U urealyticum positive babies had fewer signs of respiratory distress syndrome on early chest radiographs (p = 0.038), and they could be weaned from their ventilation settings (fraction of inspired oxygen (FIO(2)) and mean airway pressure) more quickly in the first few days. Subsequently U urealyticum positive babies deteriorated clinically and radiologically. More often they required ventilation to be restarted (p = 0.051), a higher proportion being ventilated on day 10 (p = 0.027) with higher FIO(2) (p = 0.001) and mean airway pressure (p = 0.002). Their chest radiographs showed more emphysematous changes as early as day 5 (p = 0.045), with a pronounced difference by day 10 (p = 0.009). CONCLUSIONS: Preterm ventilated babies with U urealyticum in their tracheal secretions have a different clinical and radiological course, with less acute lung disease but early onset of CLD, compared with those with negative cultures.

An unusual presentation of neonatal adrenal hemorrhage.

Case report of a neonate presenting within 1 h of birth with right side scrotal swelling and a dusky skin discoloration thought clinically to be a hydrocele or testicular torsion. Ultrasound examination demonstrated bilateral hydroceles, more prominent on the right, scrotal oedema and a perinephric loculated fluid collection secondary to right adrenal hemorrhage. We review the ultrasound appearance of the normal and haemorrhagic neonatal adrenal and discuss the differential diagnosis of both neonatal adrenal lesions and scrotal swellings. The role and benefits of ultrasound in the primary diagnosis and management of neonatal adrenal hemorrhage is emphasized.

Transient synovitis: is there a need to aspirate hip joint effusions?

There is debate as to the optimal management of children with hip joint effusions especially regarding the decision to aspirate. The objective of this study was to determine whether there is a need to aspirate hip joint effusions detected on ultrasound in patients with clinical transient synovitis (TS) and to identify the natural history of these effusions. Twenty-five children with proven hip joint effusions were followed up sequentially by clinical and radiological examination until symptom free. The mean age was 6 years with equal right/left distribution. No child underwent hip aspiration and no cases of sepsis were missed. The median size of hip effusion detected on ultrasound at presentation was 9 mm. At 7 days 60% (15/25) of patients had a normal clinical examination with no detectable effusion on ultrasound. At 14 days 16% (4/25) had an effusion detectable on ultrasound but they were all pain and limp free and their effusions were reducing in size. These results support the known benign nature of TS and that it will settle with conservative treatment.

Substrate water exchange in photosystem II depends on the peripheral proteins.

The (18)O exchange rates for the substrate water bound in the S(3) state were determined in different photosystem II sample types using time-resolved mass spectrometry. The samples included thylakoid membranes, salt-washed Triton X-100-prepared membrane fragments, and purified core complexes from spinach and cyanobacteria. For each sample type, two kinetically distinct isotopic exchange rates could be resolved, indicating that the biphasic exchange behavior for the substrate water is inherent to the O(2)-evolving catalytic site in the S(3) state. However, the fast phase of exchange became somewhat slower (by a factor of approximately 2) in NaCl-washed membrane fragments and core complexes from spinach in which the 16- and 23-kDa extrinsic proteins have been removed, compared with the corresponding rate for the intact samples. For CaCl(2)-washed membrane fragments in which the 33-kDa manganese stabilizing protein (MSP) has also been removed, the fast phase of exchange slowed down even further (by a factor of approximately 3). Interestingly, the slow phase of exchange was little affected in the samples from spinach. For core complexes prepared from Synechocystis PCC 6803 and Synechococcus elongatus, the fast and slow exchange rates were variously affected. Nevertheless, within the experimental error, nearly the same exchange rates were measured for thylakoid samples made from wild type and an MSP-lacking mutant of Synechocystis PCC 6803. This result could indicate that the MSP has a slightly different function in eukaryotic organisms compared with prokaryotic organisms. In all samples, however, the differences in the exchange rates are relatively small. Such small differences are unlikely to arise from major changes in the metal-ligand structure at the catalytic site. Rather, the observed differences may reflect subtle long range effects in which the exchange reaction coordinates become slightly altered. We discuss the results in terms of solvent penetration into photosystem II and the regional dielectric around the catalytic site.

Magnetic resonance imaging as the primary imaging modality in children presenting with acute non-traumatic hip pain.

The role of magnetic resonance imaging (MRI) in children presenting with acute non-traumatic hip pain was evaluated prospectively. Hip MRI was performed in addition to standard investigations (arthrosonography +/- hip radiographs) in 50 children presenting to the accident and emergency department of a paediatric hospital. MRI was performed on an open 0.23T system and comprised gradient echo T1 weighted coronal, fast spin echo T2 weighted coronal and inversion recovery spin echo (IRSE) axial sequences. Diagnostic quality MRI examinations were obtained in 94% of children. The IRSE sequence was the most reliable at determining underlying disorder (p<0.002). Interobserver agreement on the MRI examinations was very good with unweighted kappa value of 0.89, 95% confidence intervals 0.79, 0.99. Sensitivity of MRI was 0.79 (0.68, 0.90, specificity 1.00 (0.89, 1.00), accuracy 0.81 (0.70, 0.92), PPV 1.00 (0.89, 1), NPV 0.36 (0.25, 0.47). Sensitivity of standard imaging was 0.70 (0.54-0.86), specificity 0.57 (0.41, 0.73), accuracy 0.72 (0.56, 0.88), PPV 0.91 (0.75, 1.00), NPV 0.24 (0.08, 0.40). MRI correctly identified all seven children with serious underlying disorder whereas conventional imaging correctly diagnosed only two. Pelvic musculoskeletal infection was associated with the combination of marked alteration in signal in tissues adjacent to a symptomatic hip and an erythrocyte sedimentation rate of >20 mm 1st h (p<0.0001). In conclusion, MRI is a practical, well accepted and accurate non-invasive imaging technique in children presenting with acute non-traumatic hip pain. Combined with inflammatory markers MRI can be used to determine those children who require aggressive management. Where it is available, MRI is the imaging modality of choice in this condition.

Musculoskeletal examination teaching in rheumatoid arthritis education: trained patient educators compared to nonspecialist doctors.

OBJECTIVE: To assess whether students taught by trained patients acquire the same levels of competence in musculoskeletal examination skills as students taught by nonspecialist doctors. METHODS: Year 1 Graduate Medical Program (GMP) students (N = 25) at Hospital A were randomized to 8 tutorial groups, each comprising 3-4 students. Groups were taught hand and wrist examination skills by patient educators trained by the Searle Patient Partners in Arthritis program (patient partners). Students at Hospitals B and C (N = 12) remained in their normal tutorial groups, each comprising 3-4 students. Groups at Hospitals B and C were taught hand and wrist examination skills by doctors who had no specialized training in musculoskeletal medicine or orthopedics, with an untrained patient present. RESULTS: Students' mean self-ratings of examination skills before and students' patient partners, and consultants' mean ratings of students' examination skills after the tutorial were summed. Before the tutorial there were no significant differences in level of skill between students at Hospitals A, B, and C as measured by students' self-ratings. After the tutorial all students showed clear gains in levels of skill. Students taught by patient partners had higher levels of skill than those taught by doctors for 3 (p<0.01) and 4 (p<0.05) out of 14 examination skills and all 4 communication skills (p<0.05), as measured by both patient partners' and consultants' ratings. Students taught by doctors showed higher levels of skill for 2 observation skills, but these differences were not significant. CONCLUSION: Patient partners are either equal or superior to doctors not specifically trained in musculoskeletal medicine or orthopedics, in the teaching of musculoskeletal examination techniques and basic communication skills.

Magnetic resonance imaging of the paediatric chest.

Magnetic resonance (MR) has an important role to play in the imaging of the paediatric chest, not least because of its zero ionizing radiation dose. Computerized tomography (CT) has been the preferred technique for cross-sectional imaging to date because of the ease of access, speed and superior spatial resolution. This article discusses the clinical situations where magnetic resonance may be used as the primary cross sectional imaging modality. The clinical indications and the complimentary roles of magnetic resonance and computerized tomography are discussed. The patient preparation, technical aspects, advantages and disadvantages of MR are documented.

High rates of Chlamydia trachomatis infections in young Papua New Guinean infants.

OBJECTIVE: Determine the importance of Chlamydia trachomatis in the etiology of severe infection in young Papua New Guinean infants. METHODS: Between March, 1991, and April, 1993, children <3 months old were recruited as outpatients at Goroka Base Hospital, Papua New Guinea, as part of a multicenter study in four developing countries. Children with predefined inclusion criteria were enrolled. C. trachomatis was identified by direct fluorescent antibody staining in nasopharyngeal aspirates (NPAs) collected from children with and without signs of severe disease and eye swabs from children with and without conjunctivitis. Two to three radiologists read chest radiographs without knowledge of clinical and laboratory findings. RESULTS: Of 3280 outpatients seen 2168 enrolled, 955 NPAs were tested for C. trachomatis and 549 chest radiographs were read. Of 210 eye swabs from children with conjunctivitis 57% were positive for C. trachomatis compared with 8% from 167 children with no conjunctivitis. The prevalence of C. trachomatis in NPAs was 9% in asymptomatic children and 18 and 33% in children with nonsevere or severe pneumonia, respectively. C. trachomatis in NPAs was strongly associated with clinically severe pneumonia [odds ratio (OR), 2.91], reduced arterial oxygen saturation (OR 2.58) and radiographic evidence of pneumonia (OR 5.84) and was also associated with pneumococcal bacteremia (OR 3.48). CONCLUSIONS: In Papua New Guinea Chlamydia must be considered as a cause when treating pneumonia in infants, and effective treatment and prevention of sexually transmitted diseases are urgently needed for a number of reasons, including the need to curb high rates of chlamydial infection in women and infants.

Patients teach students: partners in arthritis education.

CONTEXT: A large metropolitan teaching hospital within The Northern Clinical School, University of Sydney. OBJECTIVE: To assess whether students taught by trained patients (Patient Partners) acquire the same levels of competence in musculoskeletal examination skills for arthritis as students taught by Consultant Rheumatologists. SUBJECTS: Year four medical students in a six-year Undergraduate Medical Programme. METHOD: Students randomized to eight tutorial groups were taught musculoskeletal examination skills in a 75-90 minute tutorial. Four groups were taught by Consultants with an untrained patient present and four groups were taught by Patient Partners. RESULTS: Students' mean self-ratings of skill before and after their tutorial were summed. For both groups, self-ratings before the tutorial were similar. After the tutorial both groups showed substantial gains in levels of skill. Patient Partners' ratings of students' taught by either Consultants or Partners were comparable. CONCLUSIONS: Patient Partners are at least equal to Consultant Rheumatologists in the teaching of musculoskeletal examination techniques for arthritis.

Congenital hemihypertrophy and epithelioid haemangioendothelioma in a 10-year-old boy: a case report.

Epithelioid haemangioendothelioma has not been previously described in a patient with congenital hemihypertrophy and diabetes mellitus. Hepatic nodules were incidentally discovered on a routine US examination searching for known associated abnormalities. Pulmonary nodules were present on chest X-ray and CT of the lungs. The diagnosis was confirmed by open biopsy of a hepatic nodule. Despite significant disease progression the patient remains symptom free.

With advances in medical imaging can the radiologist reliably diagnose Wilms' tumours?

AIM: To evaluate whether radiologists can accurately differentiate Wilms' tumours from other paediatric abdominal masses with renal involvement using modern imaging methods alone. METHODS: From February 1993 to June 1997, 23 patients presented to the Paediatric Oncology Service at The Royal Hospital for Sick Children, Edinburgh with an intra-abdominal mass which had renal involvement. Nine patients had Wilms' tumours, 12 had neuroblastomas, one patient had xanthogranulomatous pyelonephritis and there was a single case of a mesoblastic nephroma. In each case, two radiologists retrospectively reviewed the initial imaging examinations and independently reached a radiological diagnosis. RESULTS: The radiologists were concordant and reached the correct diagnosis in 20/23 cases (87%), unsure of the diagnosis in one case (4.3 %) and discordant in two cases (8.7 %). Radiologists should be aware that a mesoblastic nephroma can have identical imaging features to a Wilms' tumour. In most cases, ultrasound and a chest X-ray were sufficient to reach the correct diagnosis although computed tomography (CT) and magnetic resonance imaging were superior for demonstrating the relationship of the mass to the great vessels, retroperitoneum and spinal canal. Inferior vena cava invasion was strongly predictive of a Wilms' tumour. Displacement of the great vessels, extension of the mass across the mid-line, renal displacement and tumour calcification on CT were more suggestive of a neuroblastoma although these features were also seen in a significant number of patients with Wilms' tumours. Encasement of vessels by tumour, a paravertebral mass and spinal canal invasion were highly predictive of neuroblastoma. CONCLUSION: In this study, radiologists were accurate at diagnosing Wilms' tumours using modern imaging methods, however, care should be taken in children who are less than 1 year of age as a mesoblastic nephroma may have identical imaging characteristics.

Spontaneous involution of pulmonary sequestration in children: a report of two cases and review of the literature.

BACKGROUND: Two cases of pulmonary sequestration which regressed spontaneously are presented. OBJECTIVE: To demonstrate the value of imaging studies in the diagnosis and follow-up of some forms of congenital masses of the lung in asymptomatic patients. MATERIAL AND METHODS: We reviewed the clinical records and imaging studies of two asymptomatic children, one newborn and the other 3 months old, with thoracic masses which demonstrated variable degrees of spontaneous involution. RESULTS: Abdominal ultrasound performed on the newborn with a palpable mass showed a triangular echogenic mass with a large central feeding vessel arising from the aorta. The mass had disappeared on follow-up US exam performed 6 years later. CT was performed in the 3-month-old patient with a persistent retrocardiac mass. A soft-tissue density mass in the left pulmonary base with a large feeding vessel arising from the aorta was visualised on contrast-enhanced CT. Five years later, a new CT scan showed significant shrinkage of the mass and no vessel. CONCLUSION: Radiological techniques such as real-time US with Doppler imaging and contrast-enhanced CT may establish the diagnosis of pulmonary sequestration by demonstrating the mass and its systemic vessel, thereby eliminating the need for more aggressive imaging procedures. Partial or total disappearance of these masses represents a further example of involutive pathology and suggests that not all cases of pulmonary sequestration should be surgically treated.

Proton irradiation of [18O]O2: production of [18F]F2 and [18F]F2 + [18F] OF2.

The production of 18F electrophilic reagents via the 18O(p,n)18F reaction has been investigated in small-volume target bodies made of aluminum, copper, gold-plated copper and nickel, having straight or conical bore shapes. Three irradiation protocols-single-step, two-step and modified two-step-were used for the recovery of the 18F activity. The single-step irradiation protocol was tested in all the target bodies. Based on the single-step performance, aluminum targets were utilized extensively in the investigation of the two-step and modified two-step irradiation protocols. With an 11-MeV cyclotron and using the two-step irradiation protocol, > 1Ci [18F]F2 was recovered reproducibly from an aluminum target body. Probable radical mechanisms for the formation of OF2 and FONO2 (fluorine nitrate) in the single-step and modified two-step targets are proposed based on the amount of ozone generated and the nitrogen impurity present in the target gases, respectively.

Early continuous ST segment monitoring in unstable angina: prognostic value additional to the clinical characteristics and the admission electrocardiogram.

BACKGROUND AND OBJECTIVE: In unstable angina, clinical characteristics, resting electrocardiography, and early continuous ST segment monitoring have been individually reported to identify subgroups at increased risk of adverse outcome. It is not known, however, whether continuous ST monitoring provides additional prognostic information in such a setting. DESIGN: Observational study of 212 patients with unstable angina without evidence of acute myocardial infarction admitted to district general hospitals, who had participated in a randomised study comparing heparin and aspirin treatment versus aspirin alone. METHODS: Clinical variables and a 12 lead electrocardiogram (ECG) were recorded at admission, and treatment was standardised to include aspirin, atenolol, diltiazem, and intravenous glyceryl trinitrate, in addition to intravenous heparin (randomised treatment). Continuous ST segment monitoring was performed for 48 h and all inhospital adverse events were recorded. RESULTS: The admission ECG was normal in 61 patients (29%), showed ST depression in 59 (28%) (17 > or = 0.1 mV), and T wave changes in a further 69 (33%). The remaining 23 had Q waves (18), right bundle branch block (four), or ST elevation (one). During 8963 h of continuous ST segment monitoring (mean 42.3 h/patient), 132 episodes of transient myocardial ischaemia (104 silent) were recorded in 32 patients (15%). Forty patients (19%) had an adverse event (cardiac deaths (n = 3), non-fatal myocardial infarction (n = 6) and, emergency revascularisation (n = 31)). Both admission ECG ST depression (P = 0.02), and transient ischaemia (P < 0.001) predicted an increased risk of non-fatal myocardial infarction or death, while no patients with a normal ECG died or had a myocardial infarction. Adverse outcome was predicted by admission ECG ST depression (regardless of severity) (odds ratio (OR) 3.41) (P < 0.001), and maintenance beta blocker treatment (OR 2.95) (P < 0.01). A normal ECG predicted a favourable outcome (OR 0.38) (P = 0.04), while T wave or other ECG changes were not predictive of outcome. Transient ischaemia was the strongest predictor of adverse prognosis (OR 4.61) (P < 0.001), retaining independent predictive value in multivariate analysis (OR 2.94) (P = 0.03), as did maintenance beta blocker treatment (OR 2.85) (P = 0.01) and admission ECG ST depression, which showed a trend towards independent predictive value (OR 2.11) (P = 0.076). CONCLUSIONS: Patients with unstable angina and a normal admission ECG have a good prognosis, while ST segment depression predicts an adverse outcome. Transient myocardial ischaemia detected by continuous ST segment monitoring in such patients receiving optimal medical treatment provides prognostic information additional to that gleaned from the clinical characteristics or the admission ECG.