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Biomedical subjects

M MacLeod

Publications and source records attributed to M MacLeod.

At least 19 recordsLinked to original sources
PubMed1999

An assessment of the environmental fate and exposure of benzene and the chlorobenzenes in Canada.

Systematic modelling of the fate of benzene and the chlorobenzenes is presented which follows a four-stage process of chemical classification, quantifying discharge rates and environmental concentrations, evaluative assessment of fate and regional mass balance modelling has been carried out for the southern Ontario region. The EQC model was applied to determine the principal transport and transformation processes experienced by this group of chemicals, which vary considerably in volatility and hydrophobicity. Observed environmental concentrations are in satisfactory agreement with the predictions of the steady state Level III ChemCAN model of chemical fate. A multiple pathway human exposure model which estimates intake of contaminants by residents of southern Ontario has been developed and applied to these chemicals. A novel method of deducing maximum tolerable environmental concentrations is presented. Results suggest that benzene and 1,4-dichlorobenzene are present in the environment at levels sufficient to cause exposures near allowable daily intake (ADI) levels for the general population, but the other substances are present at levels which result in exposure ranging from 1/10 to 1/1000 of the ADI.

Benzene↗
PubMed1998

'Being there': learning through active participation.

Students engagement in learning is predicated not only on interest but on the perception of relevance to their needs. A hermeneutic interpretation of narrative student evaluation data from an introduction to nursing lecture course that was taught by means of a practice-based phenomenological approach revealed a pattern of student learning in which students moved from detachment to active participation in their learning. The stories shared by nurses in the practice setting were instrumental in introducing students to the world of nursing and facilitating a sense of belonging. Once engaged in the experience, students looked for opportunities to become active participants in their learning. A practice-based phenomenological approach to a theory course maximizes opportunities for student participation. Active reflection and integration allow students to make their own connections between theory and practice.

Curriculum↗
PubMed1998

Issues for nurses in rural and remote Canada.

Canada is a vast country with great diversity in its landscape, industry, culture and communities. The healthcare issues and concerns of people living in rural and remote areas are as fully diverse as the people and the landscape. This article describes the context of rural and remote nursing practice in Canada and discusses issues of health status and the social determinants of health, geographical isolation, professional isolation and cultural safety. It concludes with current initiatives in practice, education, research and policy. Particular issues facing nurses in rural and remote First Nations communities are highlighted.

Canada↗
PubMed1997

Evaluation of pelvic fractures. Clinical and radiologic.

This article gives the orthopedic surgeon a framework to use during the initial evaluation of a patient with a pelvic fracture in the emergency room. The essential elements of the assessment of instability, both clinically and radiologically, are given in this article. Examples of the major patterns of instability are provided.

Fractures, Bone↗
PubMed1996

A phase I study of combined radiation therapy with 5-fluorouracil and low dose folinic acid in patients with locally advanced pancreatic or biliary carcinoma.

PURPOSE: To evaluate the toxicities of a Phase I study of radiation therapy with concurrent 5-fluorouracil (5FU) and low dose folinic acid in patients with locally advanced pancreatic or biliary carcinoma. METHODS AND MATERIALS: Twenty-seven patients with locally advanced carcinoma of the pancreas (n = 19), bile duct (n = 7), and gall bladder (n = 1) were entered into a Phase I study of combined radiation therapy, 5FU, and folinic acid. Radiation was given as a split course of 40 Gy in 20 daily fractions with a gap of 2 weeks after 20 Gy. 5-Fluorouracil, 300 to 375 mg/m2/day and folinic acid, 20 mg/m2/day were given as an i.v. bolus daily for 5 days beginning on day 1 and again on day 29. RESULTS: Eight patients developed Grade 3 or 4 toxicities (National Cancer Institute common toxicity criteria) including nausea and vomiting (n = 4), oral mucositis (n = 4), myelosuppression (n = 2), infection (n = 2), and diarrhea (n = 1). Four patients did not complete the planned protocol due to treatment toxicities. There were two treatment deaths secondary to septic neutropenia. Treatment toxicity appeared to be related to age (> 70), performance status (ECOG = 2), and 5FU dose (> 350 mg/m2/day). CONCLUSION: This protocol is poorly tolerated by elderly patients or those with poor performance status, and 350 mg/m2/day is our recommended dose for 5FU as given in this protocol.

Adult↗
PubMed1995

Psychosocial adjustment in children with port-wine stains and prominent ears.

OBJECTIVE: To evaluate psychosocial adjustment in children with port-wine stain (PWS) and children with prominent ears (PE). METHOD: Thirty-two children aged 7 to 16 years with facial PWS and 42 children with PE were evaluated using the Harter Self-Perception Profile, the Revised Children's Manifest Anxiety Scale, the Children's Depression Inventory, the Disfigurement Perception Scale, and the Child Behavior Checklist. Results were compared with normative data for the local population or with a control group. Profile scores were correlated with severity of the PWS or prominence of the ears. RESULTS: Children with PE had poorer self-perception, higher concentration anxiety, and more internalizing and externalizing symptoms, and they were more withdrawn and had more social problems than children with PWS. The children with PWS functioned as well as or better than nondisfigured peers on measurements of psychosocial adjustment, while children with PE scored lower than nondisfigured peers on measures of self-perception and parent-rated social and attention problems. There was no correlation between degree of disfigurement and level of psychosocial adjustment. CONCLUSIONS: Psychosocial adjustment varied according to the nature of the disfigurement or deformity and was unrelated to the severity of the disfigurement.

Adaptation, Psychological↗
PubMed1995

Renal artery stenosis managed by Palmaz stent insertion: technical and clinical outcome.

OBJECTIVE: To assess the technical and clinical outcome of Palmaz renal artery stent insertion in patients with renal artery stenosis. DESIGN: Twenty-nine patients with radiological evidence of renal artery stenosis and hypertension (16 patients, mean +/- SD diastolic blood pressure 100.5 +/- 8.16 mmHg) and/or renal impairment (17 patients, mean +/- SD serum creatinine 376 +/- 169 mu mol/l) were referred for radiological intervention. Of these, 22 had ostial atheromatous lesions, six had atheromatous non-ostial lesions and one patient had fibromuscular dysplasia. Palmaz stent insertion was performed where either previous or concomitant percutaneous transluminal renal angioplasty (PTRA) had been unsuccessful. Technical success was defined primarily as <30% residual stenosis. A prospective radiological and clinical follow-up was performed and the results compared with the outcome following PTRA alone in a similar group of patients from our centre. RESULTS: Immediate technical success was achieved in all 29 patients. Follow-up angiography in 24 patients after a mean of 7 months showed restenosis in four patients. The hypertension was not 'cured' in any patient; a blood pressure fall was observed in seven patients (44%) and no change in the remaining nine subjects (56%). Renal function improved in four patients (24%), two of whom had angiotensin converting enzyme inhibitor-exacerbated renal impairment. This compares with an immediate technical success of 81% for PTRA alone, with cure in 50% and improvement in 32% of patients with hypertension and improvement in renal function in 64.7% of patients with renal impairment. CONCLUSIONS: Palmaz renal artery stent insertion has a higher technical success rate than PTRA, but the clinical improvement is disappointing in our patient population.

Adult↗
PubMed1994

'It's the little things that count': the hidden complexity of everyday clinical nursing practice.

This article reports on one aspect of a phenomenological study of everyday experience in nursing and how it contributes to the development of nursing expertise. The study was carried out with 10 'excellent, experienced' surgical ward sisters in two Scottish teaching hospitals. The ward sisters were found to help individual patients towards recovery by making the ward work for all. When moment-by-moment nursing practice, the context of nursing experience, is examined, it is found to be patient-centred and complex, geared towards multilayered goals. Three distinct yet inextricably intertwined processes--noticing, understanding and acting--characterize how nurses practise nursing. The quality of these processes contributes to the effectiveness of nurses' caring practices. The 'little things' of nursing practice make a difference to patients because they are imbued with nursing knowledge and skill.

Humans↗
PubMed1986

A cloned fragment of HeLa DNA containing consensus sequences of satellite II and III DNA hybridizes with the Drosophila P-element and with the 1.8 kb family of human KpnI fragments.

We have cloned a repetitive EcoRI fragment from the human genome which displays weak homologies with the Drosophila melanogaster transposable P-element. This cloned DNA appeared not to be a mobile element but, instead, a divergent member of human satellite II or III DNAs. We present here the first complete nucleotide sequence of a 1.797 kilobase pair (kb) satellite-like DNA. Moreover, this EcoRI satellite monomer contains a unique sequence of 49 basepairs (bp) that is devoid of the satellite consensus repeat 5'TTCCA3'. Southern hybridization analysis revealed that the cloned insert is closely related to a highly repetitive 1.8 kb KpnI family of tandemly organized satellite DNAs. Thus, the relationships among these satellite DNA families appear to be complex and may be a factor in their copy number, position and spatial organization.

Animals↗
PubMed1979

A crossover clinical trial of piroxicam, indomethacin and ibuprofen in rheumatoid arthritis.

A single-blind, crossover trial was carried out in 24 patients with definite or classical rheumatoid arthritis to compare the effectiveness and tolerability of piroxicam (20 mg once daily) with that of indomethacin (25 mg 3-times daily), ibuprofen (400 mg 3-times daily) and placebo. Each drug was given in random order for a period of 1 week. Pain, joint tenderness and morning stiffness decreased and grip strength increased with piroxicam compared to placebo; no statistically significant difference could be found between piroxicam and the two other active agents. A reduction in joint circumference could not be demonstrated with piroxicam or ibuprofen but most patients did not have reducible swelling in their finger joints. Piroxicam was just as effective as the other two drugs overall, but fewer side-effects were noted with piroxicam.

Adult↗
PubMed1979

Renal osteopenia - an assessment of long-term therapy with vitamin D analogues.

Renal bone disease was assessed for an average of 5.5 years in 9 patients on maintenance haemodialysis. The investigative methods included serial biochemical estimations, radiographic skeletal surveys and quantitative bone histology. Repeated bone mineral analyses and neutron activation analyses of a hand were also performed in order to monitor changes in skeletal calcium content. Before treatment, progressive osteodystrophy was demonstrated by all techniques. Following therapy with the vitamin D analogues, all patients noted symptomatic improvement; serum alkaline phosphatase reverted to normal and serum parathyroid hormone concentrations decreased. Radiographically, subperiosteal erosions healed while the histological features of osteomalacia and osteitis fibrosa were abolished. Both bone mineral and neutron activation analyses indicated that progressive skeletal demineralisation had been halted. However, a sustained increase in the overall mineral content of bone was not demonstrated. Thus, vitamin D therapy although improving the biochemical, radiological, and histological features of renal osteodystrophy may not restore bone mass to osteopenic bone.

Adult↗