Biomedical subjects

C M Duffy

Publications and source records attributed to C M Duffy.

At least 19 recordsLinked to original sources

PubMed2001

Acute rheumatic fever and poststreptococcal reactive arthritis: diagnostic and treatment practices of pediatric subspecialists in Canada.

OBJECTIVE: We conducted a survey of pediatric specialists in rheumatology, cardiology, and infectious diseases to ascertain present Canadian clinical practice with respect to diagnosis and treatment of acute rheumatic fever (ARF) and poststreptococcal reactive arthritis (PSReA), and to determine what variables influence the decision for or against prophylaxis in these cases. METHODS: A questionnaire comprising 6 clinical case scenarios of acute arthritis occurring after recent streptococcal pharyngitis was sent to members of the Canadian Pediatric Rheumatology Association, and to heads of divisions of pediatric cardiology and pediatric infectious diseases at the 16 university affiliated centers across Canada. RESULTS: There is considerable variability with respect to diagnosis in cases of ReA following group A streptococcal (GAS) infection both within and across specialties. There is extensive variability regarding the decision to provide prophylaxis in cases designated as ARF or PSReA. Findings indicated that physicians are most comfortable prescribing antibiotic prophylaxis in the presence of clear cardiac risk and are less inclined to such intervention for patients diagnosed with PSReA. When prophylaxis was recommended for cases of PSReA, the majority of respondents prescribed longer term courses of antibiotics. CONCLUSION: The lack of observed consistency in diagnosis and treatment in cases of reactive arthritis post-GAS infection likely reflects the lack of universally accepted criteria for diagnosis of PSReA and insufficient longterm data regarding carditis risk within this population. There is a need for clear definitions and treatment guidelines to allow greater consistency in clinical practice across pediatric specialties.

Acute Disease↗

PubMed2000

Head and neck manifestations of Kawasaki disease.

Kawasaki disease, also known as acute infantile febrile mucocutaneous lymph node syndrome, is a self-limited vasculitic disease of infants and young children. The cause of the disease remains uncertain. Within the constellation of signs and symptoms, there are numerous otolaryngologic manifestations. The following represents the largest series of patients in the otolaryngology literature, involving 155 confirmed cases of Kawasaki disease as treated at our institution during the last 10 years. The demographic data, clinical pictures of the typical and atypical forms of the illness, as well as the laboratory values, therapy and complications are discussed.

Aspirin↗

PubMed2000

Sevoflurane and anesthesia for neurosurgery: a review.

This review assesses the extent to which sevoflurane fulfills the requirements of the ideal inhalational agent for use in neuroanesthetic practice. Sevoflurane's pharmacokinetic profile is outlined. Data from animal and human studies are used to discuss its effects on cerebral hemodynamics, central nervous system monitoring, and cardiovascular parameters. Where possible, sevoflurane is compared with isoflurane, currently considered the inhalational agent of choice in neuroanesthesia. Sevoflurane's potential for toxicity is reviewed.

Anesthesia, Inhalation↗

PubMed2000

Inflammatory arthritis in children with osteochondrodysplasias.

Osteochondrodysplasias are a heterogeneous group of genetic skeletal dysplasias. Patients with these diseases commonly develop an early degenerative arthritis or osteoarthritis. Occasional observations of inflammatory arthritis have been made in this population but such observations are based on clinical grounds alone without confirmatory imaging studies. Four patients followed up in a paediatric rheumatology clinic with three different skeletal dysplasias, who had both clinical and radiological evidence of an inflammatory arthritis and coexistent degenerative arthritis, are described.

Adolescent↗

PubMed2000

Update on functional assessment tools.

In recent years, there has been a tremendous growth in the development of measurement instruments that evaluate health status, functional status, disability, and quality of life in adults with rheumatic diseases. In the past decade, similar measures have been developed for application in children with rheumatic diseases. These include the Childhood Arthritis Impact Measurement Scales (CHAIMS), the Childhood Health Assessment Questionnaire (CHAQ), the Juvenile Arthritis Functional Assessment Report (JAFAR), the Juvenile Arthritis Self-report Index (JASI), the Juvenile Arthritis Quality of Life Questionnaire (JAQQ), and the Childhood Arthritis Health Profile (CAHP). The latter 2 instruments assess health related quality of life (HRQOL) and they are discussed here. The need to adapt this kind of instrument for use in an international climate creates an interesting dilemma and this is discussed.

Arthritis, Juvenile↗

PubMed1999

Botulinum toxin A in hamstring spasticity.

Hamstring injection of Botulinum toxin A (BtA) may have a role in the conservative management of flexed knee gait in cerebral palsy or in simulating the effect of surgery. Ten children who were likely to require future hamstring lengthening were injected. Short term outcome was assessed by clinical examination and 3-D gait analysis. Mean popliteal angle decreased by 16 degrees and maximum knee extension in stance increased by 8 degrees, the latter relapsing by 12 weeks. Mean pelvic tilt tended to increase suggesting that isolated hamstring weakening be approached with caution. Energy cost of walking was not significantly changed in six of the ten patients. A small increase in knee extension in stance was often associated with patient satisfaction. There are theoretical grounds for expecting an associated increased longitudinal muscle growth after BtA injection.

Botulinum Toxins, Type A↗

PubMed1998

Systemic juvenile rheumatoid arthritis complicated by two different renal lesions.

Systemic-onset juvenile rheumatoid arthritis (JRA) is a complex disease which affects many organ systems. Associated renal lesions are unusual, with the possible exception of amyloidosis. We describe a girl with systemic-onset JRA who developed first membranous nephropathy and then, 3.5 years later, a severe crescentic glomerulonephritis. The membranous lesion followed therapy with intravenous immune globulin, and the possibility that this intervention caused the renal disease must be considered. It appears that both of these lesions should be added to the list of possible complications of systemic-onset JRA.

Antirheumatic Agents↗

PubMed1998

Rap1b association with the platelet cytoskeleton occurs in the absence of glycoproteins IIb/IIIa.

Platelet membrane glycoproteins (GP) IIb/IIa and rap1b, a 21 kDa GTP binding protein, associate with the triton-insoluble, activation-dependent platelet cytoskeleton with similar rates and divalent cation requirement. To examine the possibility that GPIIb/IIIa was required for rap1b association with the cytoskeleton, experiments were performed to determine if the two proteins were linked under various conditions. Chromatography of lysates from resting platelets on Sephacryl S-300 showed that GPIIb/IIIa and rap1b were well separated and distinct proteins. Immunoprecipitation of GPIIb/IIIa from lysates of resting platelets did not produce rap1b or other low molecular weight GTP binding proteins and immunoprecipitation of rap1b from lysates of resting platelets did not produce GPIIb/IIIa. Finally, rap1b was associated with the activation-dependent cytoskeleton of platelets from a patient with Glanzmann's thrombasthenia who lacks surface expressed glycoproteins IIb and IIIa. Based on these findings, we conclude that no association between GPIIb/IIIa and raplb is found in resting platelets and that rap1b association with the activation-dependent cytoskeleton is at least partly independent of GPIIb/IIIa.

Blood Platelets↗

PubMed1997

Assessment of a new ultrafiltration blood processing system.

PURPOSE: To report our clinical experience with a new blood processing device which uses ultrafiltration. We assessed safety and efficacy by evaluating: 1 ) the quality and the quantity of intraoperative shed blood processed and reinfused to the patient 2) homologous blood requirements 3) clinical status of the patient post-transfusion. METHODS: With Ethics Committee approval, the ultrafiltration device was used in six consenting patients undergoing major elective spinal surgery. Blood samples for haematology and biochemistry tests were collected from patients post-induction of anaesthesia (baseline), 1 hr and 24 hr post-autotransfusion. Volumes of blood collected and processed, and all autologous and homologous transfusions were recorded. Patients were assessed post-operatively for any adverse effects. RESULTS: Five patients had donated blood preoperatively. One patient required homologous blood products in addition to autologous blood. In two patients, the filtration cartridge became blocked and required changing midprocessing. No patient sustained device-related complications. One patient had postoperative haematuria which resolved spontaneously within two hours. CONCLUSION: The ultrafiltration device was safe and effective in reducing homologous blood requirements in six patients undergoing elective spinal surgery. Further evaluation of the ultrafiltration device will be necessary, especially in view of the blockage of the filtration cartridge.

Blood Transfusion, Autologous↗

PubMed1997

Comparison of cerebral oximeter and evoked potential monitoring in carotid endarterectomy.

PURPOSE: To assess the cerebral oximeter, which measures regional oxygen saturation (rSO2) continuously and noninvasively, as a cerebral monitor during carotid endarterectomy (CEA). The rSO2 was compared with Somatosensory Evoked Potentials (SSEPs) as an indicator for shunting and as a predictor of postoperative neurological deficits. METHODS: Seventy-two consenting patients undergoing CEA with general anaesthesia were studied. Normocarbia, normothermia and normotension were maintained. Cerebral monitoring consisted of bilateral median nerve SSEPs and the INVOS 3100 cerebral oximeter with the sensor pad placed on the ipsilateral forehead. Decreases in SSEP amplitude of 50% and in rSO2 of 10% were considered clinically significant. Neurological assessment was performed at emergence from anaesthesia, 24 hr postoperatively and at discharge. The rSO2 changes were compared with SSEP changes and with neurological deficits. Statistical analysis was with chi square and analysis of variance P < 0.05 was considered significant. RESULTS: During carotid artery clamping, rSO2 decreased from 72 +/- 8% to 68 +/- 9% and mean arterial blood pressure increased from 92 +/- 14 mmHg to 98 +/- 14 mmHg. In four patients, the carotid artery was shunted because of SSEP changes after cross-clamping. Five patients had > or = 10% decreases in rSO2 following clamp application. Changes in both SSEP and rSO2 occurred in two patients. Three of the four shunted patients had transient postoperative neurological deficits. One patients had a transient deficit without changes in either monitor. There were no persistent postoperative deficits. Compared with SSEPs, rSO2 had a sensitivity of 50% and a specificity of 96%. CONCLUSION: Clinical experience with this evolving technology is ongoing. Its role in neurovascular procedures has yet to be established.

Aged↗

PubMed1997

Health assessment in the rheumatic diseases of childhood.

Assessment of children and adults with rheumatic diseases, both in clinical practice and controlled clinical trials in rheumatology, has traditionally focused on the measurement of disease activity. More recently emphasis has been placed on the need to incorporate estimates of physical, social, and mental functioning into health assessment. Thus there has been a tremendous growth in the development of measurement instruments that evaluate health status, functional status, disability, and quality of life. This type of measurement has become essential, particularly for clinical trials in adults with rheumatic diseases, for which the AIMS (Arthritis Impact Measurement Scales), the HAQ (Health Assessment Questionnaire), and the MACTAR (McMaster-Toronto arthritis) patient preference questionnaire have been the most widely used. In the past few years, similar measures have been developed for application in children with rheumatic diseases. These include the CHAIMS (Childhood Arthritis Impact Measurement Scales), the CHAQ (Childhood Health Assessment Questionnaire), the JAFAR (Juvenile Arthritis Functional Assessment Report), the JASI (Juvenile Arthritis Self-report Index), the JAQQ (Juvenile Arthritis Quality of Life Questionnaire), and the CAHP (Childhood Arthritis Health Profile). In this review, the development and measurement properties of these childhood instruments are discussed, with particular emphasis on their potential roles as supported by recent literature.

Arthritis, Juvenile↗

PubMed1997

The influence of flexed-knee gait on the energy cost of walking in children.

There is an understanding that walking with flexed knees contributes to the increased energy cost of walking found in children with neurological conditions. To determine the influence of flexed-knee gait on energy cost of walking in a group of children without neurological abnormality, the gait patterns of 10 normal children were studied using a Vicon system and standard marker set. A telemetric system (Cosmed K2) was then used to measure the oxygen cost of walking of the same children. The tests were repeated restricting the subjects' knee extension bilaterally, using hinged braces, set to 0, 15, 30, and 45 degrees of flexion. Although the braces themselves caused a significant increase in O2 cost (mL/kg/m) (P < 0.05), due to a decrease in walking speed, no further significant increase in oxygen cost was demonstrated regardless of the degree of knee flexion imposed, despite a significant increase in measured hip flexion and ankle dorsiflexion at the 45 degrees of knee flexion setting (P < 0.05). We propose that moderate flexed-knee gait does not of itself cause an increase in the energy cost of walking and that other factors present in the physically disabled child are likely to be implicated.

Adolescent↗

PubMed1997

Catastrophic haemorrhage in a case of paediatric primary antiphospholipid syndrome and factor II deficiency.

The first case of primary antiphospholipid syndrome associated with recurrent life-threatening haemorrhages, due to the coexistence of acquired prothrombin deficiency, is described. Attention is drawn to the difficulty in diagnosing this situation, and therapeutic options are reviewed. Evidence is presented that implicates prothrombin as the protein cofactor for this lupus anticoagulant.

Adolescent↗

PubMed1997

The Juvenile Arthritis Quality of Life Questionnaire--development of a new responsive index for juvenile rheumatoid arthritis and juvenile spondyloarthritides.

OBJECTIVE: To develop a disease specific measure of quality of life for application in children with juvenile rheumatoid arthritis and juvenile spondyloarthritides-the Juvenile Arthritis Quality of Life Questionnaire (JAQQ). METHODS: Patients and their parents were interviewed by a trained interviewer using a questionnaire focusing on physical function, psychosocial function, and general symptoms to determine the most appropriate items to include in the JAQQ. Respondents volunteered items and scored them for frequency of occurrence and importance. Items so generated were scored by a panel of experts for potential responsiveness and categorized into dimensions. Item number was reduced using this scoring system. The product was then pretested to confirm its construct validity and responsiveness. Thereafter, it was distributed to clinical experts to establish face and content validity. RESULTS: 91 patients, mean age 10.35 years (range 1.25-18.0), mean disease duration 3.99 years, and their parents were included in the interview process. 220 items generated were ultimately reduced to 85. Pretesting this version of the instrument in a further 30 patients showed it to have construct validity and responsiveness and led to a further reduction in items to 74, distributed in 4 dimensions: gross motor function (17 items), fine motor function (16 items), psychosocial function (22 items), and general symptoms (19 items). Face and content validity were established in 20 clinicians. Scaling was by 7 point Likert scale to enhance responsiveness. English and French versions were developed. CONCLUSION: The JAQQ measures physical and psychosocial function and an array of general symptoms. Preliminary data suggest it is valid and responsive and thus might have potential in clinical trials.

Adolescent↗

PubMed1996

Seasonal onset of systemic-onset juvenile rheumatoid arthritis.

OBJECTIVE: This study was undertaken to investigate the recent finding of a seasonal difference in the onset of systemic-onset juvenile rheumatoid arthritis (SoJRA). We hypothesized that a seasonal onset pattern might implicate on infectious agent as a cause of SoJRA. METHODS: The date of onset was collected from the records of all patients with SoJRA from 1980 to 1992 at presentation to pediatric rheumatology clinics across Canada. The onset pattern of SoJRA was then compared with incidence data on viral infections obtained for the same period. RESULTS: Across Canada the onset of SoJRA was constant across the seasons. However, in the Prairie region there was a statistically significant seasonal pattern, with peaks in autumn and early spring. We could find no evidence that viral incidence correlated with disease incidence either throughout Canada or in the Prairie region. CONCLUSIONS: If a seasonal infectious agent causes SoJRA, then it is likely only one of several causes and may act only in certain regions. Future studies should be carried out in those areas where SoJRA does have a seasonal onset pattern.

Adolescent↗

PubMed1996

Measurement of oxygen consumption in disabled children by the Cosmed K2 portable telemetry system.

Measurement of the energy cost of walking in children with cerebral palsy or spina bifida is difficult due to the cumbersome nature of equipment used to assess oxygen consumption. Such information collected with a lightweight telemetric system, the Cosmed K2, correlated well with that from a non-portable breath-by-breath system associated with a treadmill. The K2 did not significantly affect regular gait pattern as measured by gait analysis, and repeatability was satisfactory. Measurement of the energy cost of walking in the individual is unreliable in detecting differences of less than 10%; comparison between groups is more useful.

Adolescent↗

PubMed1996

Energy consumption in children with spina bifida and cerebral palsy: a comparative study.

The authors looked for differences in the energy expenditure patterns of ambulant children with cerebral palsy and spina bifida. Oxygen consumption was measured according to type of cerebral palsy or level of spina bifida lesion, and in healthy children. The rate of oxygen consumption (mL/kg/min) was significantly higher in the children with diplegia than in those with hemiplegia or with spina bifida or the healthy children. Oxygen cost (mL/kg/m) was significantly higher and velocity was significantly slower in all the groups with disability than in the healthy children. The reason children with diplegia consumed more oxygen than other children when walking may be that their abnormal equilibrium reactions impaired their balance and their ability to control their walking speed.

Cerebral Palsy↗

PubMed1995

Juvenile spondyloarthropathies: clinical manifestations and medical imaging.

The spondyloarthropathies comprise four distinct entities--ankylosing spondylitis, psoriatic arthritis, the arthritis associated with inflammatory bowel disease, and Reiter's syndrome and other related forms of reactive arthritis. Although these are distinct diseases, they have a number of clinical, radiologic, and genetic characteristics in common which permit them to be classified under the unifying term "spondyloarthropathy". They are diseases of young adults, and when they present in patients under 16 years of age we refer to them as the "juvenile" spondyloarthropathies. They must be distinguished from juvenile rheumatoid arthritis, which is a totally separate entity; however the distinction may not always be obvious. Involvement of peripheral and sacroiliac joints commonly occurs in the juvenile spondyloarthropathies. The peripheral arthritis may be erosive and associated with bone apposition at the joint margins. Axial involvement is usually a late finding. Dactylitis and tenosynovitis are frequently present early on. Enthesitis, a highly specific feature, occurs much more often in the juvenile spondyloarthropathies than in the adult forms and it may be the only presenting feature. The plain radiograph is the primary and most important imaging modality for the assessment of these diseases. However, an expanding role of magnetic resonance imaging is evident.

Adolescent↗