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Biomedical subjects

J G Wright

Publications and source records attributed to J G Wright.

At least 109 records · Page 6Linked to original sources
PubMed1995

Variation in orthopedic surgeons' perceptions of the indications for and outcomes of knee replacement.

OBJECTIVE: To determine the agreement among orthopedic surgeons' indications for knee replacement, their perceptions of the usefulness of various treatments for osteoarthritis of the knee and their expected outcomes of knee replacement, and to determine the relation between these opinions and the number of knee replacement procedures performed by individual surgeons. DESIGN: Survey. SETTING: Ontario. PARTICIPANTS: All 392 orthopedic surgeons in the province. Of the 325 practising traceable surgeons 234 (72.0%) responded. OUTCOME MEASURES: Indications for knee replacement, perceived usefulness of treatments for osteoarthritis, perceived outcomes of knee replacement and number of knee replacement procedures performed by individual surgeons. RESULTS: The respondents disagreed on how 20 of 34 patient characteristics affected their decision to perform knee replacement surgery. They also disagreed on the usefulness of seven of eight treatments for arthritis of the knee. The respondents demonstrated variation in their expected outcomes of knee replacement. The surgeons who performed more procedures judged, on average, the outcomes to be better and to have fewer complications than the surgeons who performed fewer procedures. CONCLUSIONS: Orthopedic surgeons demonstrated disagreement about some of the indications for knee replacement, the usefulness of treatments for arthritis of the knee and the perceived outcomes of knee replacement. The areas of greatest disagreement should be the focus of future research and the development of practice guidelines.

Adult↗
PubMed1995

Endocarditis with multiple intracardiac shunts: identification and repair.

An 8-year-old boy who suffered from Hirschsprung's disease had development of tricuspid valve endocarditis that progressed to aortic root abscess formation, development of a fistulous communication between aorta and right atrium, atrial and ventricular septal defects, and a left ventricle to right atrium defect. Several surgical procedures were required. Operation consisted initially of closure of the septal defects and aortic valve repair. This was followed by homograft replacement of the aortic valve for persistent infection, and further closure of a left ventricle to right atrium fistula.

Abscess↗
PubMed1995

Univentricular heart with systemic outflow obstruction: palliation by primary Damus procedure.

In 24 consecutive infants (19 male and 5 female) with complex forms of single-ventricle physiology and systemic outflow obstruction, a modified Damus operation without the use of exogenous material was undertaken in conjunction with creation of an aortopulmonary shunt 3.5 mm in diameter. The median age at operation was 6 days (range, 1 to 170 days) and the median weight, 3.4 kg (range, 2.6 to 4.6 kg). There were nine early deaths. All 15 survivors (median follow-up, 6.5 months) were clinically well without major systemic ventricular dysfunction or atrioventricular or arterial valve regurgitation. Ten of them have undergone a superior vena cava-pulmonary shunt (one death), and 1 has required patch angioplasty of the aortic arch and innominate artery with revision of the aortopulmonary shunt. The 4 other survivors are awaiting a cavopulmonary shunt. Univariate analysis yielded the chronologic rank for an individual procedure (higher risk of death early in the series), presence of aortic arch atresia, and presence or absence of transposition of the great arteries as predictors of death. This aggressive surgical approach provides excellent early palliation, and because the operation prevents abnormal ventricular hypertrophy from pressure or volume overload, systemic ventricular function is optimally conserved for a future Fontan-type procedure.

Cardiac Surgical Procedures↗
PubMed1995

The role of children in reporting their physical disability.

OBJECTIVE: To explore the contributions of children during the development of a disability scale, and their competence using the new scale. DESIGN: A new self-report measure of pediatric physical performance, the Activities Scale for Kids (ASK), was developed based on interviews and pilot testing with children. The ASK was then filled out by children on two occasions 2 weeks apart to assess the reliability of child self-report. Validity was assessed by comparison of interview data and ASK scores from children with similar data collected from their parents, and to clinician and family global ratings of disability. SETTING: The study was conducted at a pediatric tertiary care hospital and its affiliated rehabilitation center. PATIENTS: All subjects, 5 to 15 years of age, experienced activity limitations because of musculoskeletal disorders and were free of cognitive impairment. Thirty children (mean age, 11.5 years) participated in the development of the ASK, and 28 children (mean age, 11.4 years) participated in testing of reliability and validity. RESULTS: Children generated items similar to those generated by parents (85% agreement) and identified 10 items not obtained from parents or the literature. Children demonstrated excellent test-retest reliability (intraclass correlation coefficient [ICC] = .97) using the ASK, and their scores were highly concordant with parent-reported ASK scores (ICC = .96). Validity was ascertained by comparison of ASK scores across different levels of disability based on global ratings of families and clinicians (p = .0023). CONCLUSION: Children are able to play an important role in pediatric physical disability evaluation.

Adolescent↗
PubMed1995

ECG and echocardiographic diagnosis of pulmonary thromboembolism associated with central venous lines.

The aim was to establish the prevalence of pulmonary embolism in 21 children (median age 12 months; range 5-132 months) with central venous lines in situ > 3 months (median 10 months; range 3-47). Twelve-lead electrocardiograms (ECGs) and echocardiograms were analysed in a retrospective study using ECG and echocardiographic criteria for pulmonary embolism-previously established and validated in adult patients- and standard paediatric ECG values as control data. Patients were scored as having definite (n = 7), probable (n = 5), or no pulmonary embolism (n = 9). Overall 57% of ECGs showed abnormalities compatible with pulmonary embolism. In two patients, serial ECGs obtained during an acute cardiorespiratory illness showed cumulative changes diagnostic of pulmonary embolism. Eight of 12 patients with abnormal ECGs had echocardiography; in seven of these (88%) the right ventricular end diastolic diameter was > 2SD above the mean value for age. Twelve of the patients included in this study have died; two died following an acute respiratory illness. There was postmortem evidence of pulmonary thromboembolism in both of the two children for whom necropsy information was available. The data suggest that pulmonary embolism is common in children who have central venous lines in situ for > 3 months. Serial studies are of value in some patients. Pulmonary embolism may compromise the long term survival of children with small bowel failure and preclude consideration for liver and small bowel transplantation.

Catheterization, Central Venous↗
PubMed1995

Influence of ethnic origin on the pattern of congenital heart defects in the first year of life.

OBJECTIVE: To assess the prevalence and patterns of congenital heart defects in infants requiring hospital admission in a defined population and to determine the differences in ethnic groups. DESIGN: A three year retrospective analysis of all hospital admissions for paediatric congenital heart defects in a single centre. SETTING: Tertiary referral centre for infant cardiac services in the West Midlands region, United Kingdom. PATIENTS AND METHODS: Indian, Pakistani, Bangladeshi and other individuals from the Indian subcontinent constitute 5.8% of the total population of the West Midlands region. Some 9% of infants, however, are Asian because of a high birth rate. All infants with confirmed congenital heart defects resident in this region who required hospital admission between April 1990 and March 1993 were classified as Asians and non-Asian, mainly white, infants. RESULTS: Of 1111 infants with congenital heart defects born in the West Midlands and admitted to the hospital, 17.0% were Asian, significantly more than the percentage of Asian infants in the population (P < 0.0001). Asian infants had a higher proportion of complex congenital heart disease (7% v 2.1%, P < 0.001), whereas coarctation of the aorta was more common in non-Asian (3% v 9.1%, P = 0.003). Persistent arterial duct seemed to be more common in Asian children (16% v 10%, NS), but this group included preterm infants admitted for duct ligation. There was no significant difference between the two groups in the other nine categories of congenital heart defects. CONCLUSIONS: The estimated prevalence of congenital heart defects requiring hospital admission was higher in Asian infants than in non-Asian (9.45 per 1000 v 4.56 per 1000, P < 0.0001). Complex congenital heart defects were more common in Asian infants whereas coarctation of the aorta was more common in non-Asian.

Asia↗
PubMed1995

Surgery for infants with a hypoplastic systemic ventricle and severe outflow obstruction: early results with a modified Norwood procedure.

OBJECTIVE: Prospective audit of the first year of implementation of a modified approach to palliation for infants with hypoplastic systemic ventricle and severe systemic outflow obstruction. SETTING: Tertiary referral centre for neonatal and infant cardiac surgery. PATIENTS AND METHODS: 17 of 19 infants (aged < 35 days) presenting to Birmingham Children's Hospital in 1993 with hypoplastic systemic ventricle and severe outflow obstruction underwent surgery. This was performed using a new modification of the Norwood-type arch repair, without the use of exogenous material, and a 3.5 mm Gore-tex shunt between the innominate and right pulmonary arteries. The Gore-tex shunt was replaced by a cavopulmonary shunt between 3 and 5 months later. Clinical, morphological, and functional determinants of outcome were examined. RESULTS: 10 (59%) infants survived initial surgery. All proceeded to cavopulmonary shunt without further loss. Significant atrioventricular valve regurgitation seemed to be the main risk factor for poor outcome. If this was excluded, the morphology of the dominant ventricle seemed to have little effect on the outcome of initial surgery. CONCLUSIONS: Early survival was achieved in 59% of patients in the first year of implementation of a protocol for surgery in infants with hypoplastic systemic ventricle and severe outflow obstruction. The construction of a neoaorta without the use of exogenous material may allow improved later growth of the neoaorta. Early cavopulmonary shunt can be performed safely and should reduce mid-term complications from cyanosis and systemic ventricular volume loading.

Female↗
PubMed1995

Combined atrial and arterial switch procedure for congenital corrected transposition with ventricular septal defect.

OBJECTIVES: A combined atrial and arterial switch procedure was performed in selected patients with congenitally corrected transposition to establish the morphological left ventricle as the systemic ventricle. Immediate and early follow up results are presented. BACKGROUND: Progressive right ventricular dysfunction and tricuspid regurgitation are common in patients with congenitally corrected transposition who undergo repair of associated lesions. A surgical procedure which re-establishes the left ventricle as the systemic ventricle should improve functional results. METHODS: Four symptomatic children aged from 9 months to 3 years 1 month (mean 2 years 3 months) with congenitally corrected transposition and ventricular septal defect underwent both an atrial and arterial switch procedure and were followed up for a mean of 12 months (range 6-21 months). RESULTS: There were no early or late deaths. Conduction abnormalities worsened in two patients. Hospital stay ranged from 8 to 17 days (mean 13 days). The cardiothoracic ratio decreased from a mean (range) of 0.65 (0.6 to 0.71) to 0.58 (0.52 to 0.6). Currently, three patients are in functional class I and one child is in functional class II. CONCLUSIONS: The combination of an atrial and an arterial switch procedure in symptomatic children with congenitally corrected transposition establishes the left ventricle as the systemic ventricle. The initial experience is encouraging with excellent immediate and early follow up results.

Child, Preschool↗
PubMed1995

Late systemic desaturation after total cavopulmonary shunt operations.

OBJECTIVES: To assess the medium-term results of total cavopulmonary shunt operations in children with left atrial isomerism, interrupted inferior vena cava, and complex congenital heart defects. BACKGROUND: Creation of a total cavopulmonary shunt provides very good interim palliation for children with interrupted inferior vena cava and complex congenital heart disease; however, longer term results after this operation have not been reported. METHODS: Detailed follow up of six children who underwent creation of a total cavopulmonary shunt at a tertiary referral centre. RESULTS: There were no early or late deaths. Oxygen saturations at discharge ranged from 89% to 92% (mean 90%). At last follow up (mean 4.7 years) saturations at rest ranged from 73% to 81% (mean 77%) (P < 0.05). All patients underwent exercise stress testing. At peak exercise oxygen saturations ranged from 62% to 87% (mean 71.5%) and during recovery from 68% to 85% (mean 78%). Cardiac catheterisation was performed in five patients with saturations of less than 80% at rest or peak exercise. No patient had pulmonary arteriovenous fistula. Systemic venous to hepatic venous collaterals were documented in four patients. These were localised below the diaphragm in three and above the diaphragm in one patient. The collateral vessel was successfully embolised in three of these patients, with a rise in resting oxygen saturations from 6 to 10% (mean 7%). CONCLUSIONS: The development of systemic venous to hepatic venous collaterals is a common complication in patients who undergo a total cavopulmonary shunt operation. This can lead to significant desaturation at rest and during exercise. Detailed angiographic studies of the infradiaphragmatic system veins is required for diagnosis. Transcatheter embolisation of such vessels gives good relief.

Angiography, Digital Subtraction↗
PubMed1995

Is there a difference between the epidemiologic characteristics of hip dislocation diagnosed early and late?

OBJECTIVE: To determine if there are epidemiologic differences between patients with early and late developmental dislocation of the hip (DDH). DESIGN: A chart review. SETTING: A university-affiliated children's hospital. PATIENTS: Two hundred and forty-three children, 191 with early DDH and 52 with late DDH. MAIN OUTCOME MEASURES: Sex, side involved and prevalence of bilaterality. RESULTS: There were significant differences between the two groups with respect to side involved (p < 0.0002) and bilaterality (p = 0.006) but not in relation to sex. Left-sided dislocations were predominant in the early group and right-sided dislocations in the late group. Bilaterality was more common in the late group. CONCLUSION: There is circumstantial epidemiologic evidence that late DDH may be a different entity from early DDH.

Female↗
PubMed1995

A critical appraisal of toxicity indexes in rheumatology.

Our objective was to design a grading system to judge the methodological quality of toxicity symptoms assessment in rheumatologic randomized controlled trials, and to use this grading system to evaluate rheumatology case report forms. For comparison, we also evaluated instruments derived in other clinical specialties. To further determine whether variability seen on the rheumatology case report forms would lead to variability of side effect measurement in a clinical trial setting, we conducted a survey of investigators and their coordinators in a multicenter randomized trial. We used Feinstein's definition of sensibility and a conceptual model of the process of toxicity measurement in the clinical trial setting to develop a grading system. Thirty case report forms were obtained from a convenience sample, and 7 other instruments from other disciplines were obtained through literature review. These forms were evaluated in a blinded manner by 3 reviewers. A survey of 30 trial staff from 15 centers involved in a multicenter, randomized trial of 2 active nonsteroidal antiinflammatory drugs (NSAID) in rheumatoid arthritis (RA) was undertaken to evaluate whether the variability identified in the review of the case report forms translated into variability in the measurement of side effects in clinical trial setting. The rheumatology case report forms had a mean score of 9.1 (SD = 2.6) out of 20, where 0 is the worst score and 20 is a perfect score. The structured instruments from other disciplines had a mean score of 14.9 (SD = 2.7). These means were significantly different, with p = 0.001.(ABSTRACT TRUNCATED AT 250 WORDS)

Adverse Drug Reaction Reporting Systems↗
PubMed1994

Waiting times for knee-replacement surgery in the United States and Ontario.

BACKGROUND: Canada, which has universal single-payer health insurance, is often criticized for waiting times for surgery that are longer than those in the United States. We compared waiting times for orthopedic consultations and knee-replacement surgery and patients' acceptance of them in the United States and in the province of Ontario, Canada. METHODS: A stratified random sample of 1486 Medicare recipients (629 from the U.S. national sample, 428 from Indiana, and 429 from western Pennsylvania) and 516 people from Ontario who had been hospitalized for knee replacement between 1985 and 1989 were surveyed by mail in 1992. Patients were asked how long they had waited to see an orthopedic surgeon and to have surgery, the acceptability of these waiting times, and their overall satisfaction with surgery. RESULTS: About 80 percent of the questionnaires were returned, but not all the respondents answered all the questions. The rate of response to specific questions was about 60 to 65 percent in both countries. The median waiting time for an initial orthopedic consultation was two weeks in the United States and four weeks in Ontario. The median waiting time for knee replacement after the operation had been planned was three weeks in the United States and eight weeks in Canada. In the United States, 95 percent of patients in the national sample considered their waiting time for surgery acceptable, as compared with 85.1 percent in Ontario. Overall satisfaction with surgery ("very or somewhat satisfied") was 85.3 percent for all U.S. respondents and 83.5 percent for Canadian respondents. CONCLUSIONS: Waiting times for initial orthopedic consultation and for knee-replacement surgery were longer in Ontario than in the United States, but overall satisfaction with surgery was similar.

Aged↗
PubMed1994

A thermodynamic study of the trp repressor-operator interaction.

We have measured the heats of formation of the trp repressor/operator complex by direct titration calorimetry over the temperature range 10 degrees C to 40 degrees C. A primary strong mode of binding displays the characteristic large negative heat capacity change observed by other methods in the formation of specific protein/DNA complexes. Unlike most such reactions, however, the formation of the trp repressor/operator complex is enthalpically driven throughout the physiological temperature range. After saturation of this principal mode, we also detected a secondary weaker binding mode, which we ascribe to a now well documented interaction called "half-site" binding. Although weak, this mode also exhibits an unusually large negative heat capacity change. Since the interface of the proposed secondary half-site binding mode has the same complementary stereochemistry as the primary one (due to internal symmetry), we correlate the negative heat capacity change with the formation of a stereospecific interface and not with high affinity. As in similar cases, the empirical correlation between buried non-polar surfaces and reduction of heat capacity does not account for the large negative delta Cp, nor do crystal structures reveal any further reduction in solvent excluded surfaces within the reactants upon complex formation. We attribute the "unaccounted for" decrement in the heat capacity of the complex to the stereospecific restriction of the hydrated polar elements that form the specific interface. We suggest that the "tightening of soft internal modes" at and near the polar interface of the complex is more important than previously recognized because previous considerations did not take into account the highly hydrated nature of these polar elements and the concomitant reduction in the degrees of freedom of the water structure.

Bacterial Proteins↗
PubMed1994

Percutaneous transluminal angioplasty of tibial arteries for limb salvage in the high-risk diabetic patient.

Recent advances in balloon catheter technology allow percutaneous transluminal angioplasty (PTA) of small arteries such as the tibial arteries. PTA can thus be used to treat lower limb ischemia in diabetic patients whose arterial occlusive disease is often localized to the tibial arteries. This series included 14 consecutive diabetic patients who underwent tibial PTA for treatment of limb-threatening ischemia from 1986 to 1992. PTA was selected over conventional bypass procedures because of a lack of autogenous conduit or because of an unacceptably high surgical risk. Limb loss was imminent without prompt improvement in foot perfusion in all patients. Mean follow-up of 17 months demonstrated long-term limb salvage in 10/13 (77%) and "late" cardiac-related death in 3/13 (23%). This series demonstrates that although conventional arterial bypass should routinely supersede angioplasty procedures, tibial PTA offers the opportunity for limb salvage in diabetic patients with inadequate autogenous conduit for distal tibial bypass and may serve as an option for those who are considered too high risk for conventional bypass. Morbidity and mortality rates of tibial PTA parallel those of major amputation in this population with the obvious benefit of achieving limb salvage in carefully selected diabetic patients.

Adult↗
PubMed1994

Global rating systems used in assessing knee arthroplasty outcomes.

Global, aggregated knee rating systems are commonly used to assess patient outcomes following knee arthroplasty. In this study, the authors performed a systematic literature search and found that 17% of the English-language studies addressing primary knee arthroplasty reported on patient outcomes following the procedure using a standardized global rating system. The authors describe, in detail, the rating systems' development and format. This study found 34 different rating systems represented in the literature from 1972 to 1992. Great variability was found in the rating systems' design and utilization. Additionally, these condition-specific, physician-based rating systems did not have documented studies demonstrating their reliability or validity. Future research will need to address the issues of selecting and aggregating outcome measures and of deriving any necessary weighting schemes. The ability of researchers to compare patient outcomes across studies will be enhanced when there is consistency in reported outcome measures.

Humans↗