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Biomedical subjects

M MacKinnon

Publications and source records attributed to M MacKinnon.

At least 19 recordsLinked to original sources
PubMed2001

Effects of consolidated tailings water on red-osier dogwood (Cornus stolonifera Michx) seedlings.

As part of their tailings management, the oil sand industries plan on producing consolidated (composite) tailings (CT), in which an inorganic coagulant aid (gypsum) is added to create a non-segregating deposit. The water associated with this treatment contains potentially phytotoxic levels of sodium, sulfate, chloride, boron, aluminum, fluoride and strontium. Since CT water is expected to saturate deposits in the reclamation areas, it may affect successful reclamation of these sites. Red-osier dogwood (Cornus stolonifera Michx) was demonstrated to be relatively salt resistant and to have high potential for the reclamation of mining areas. In the present study, we used red-osier dogwood to examine the effects of CT water on the accumulation of ions within plant tissue, growth, gas exchange, water potentials and chlorophyll concentration. CT water reduced shoot lengths and dry weights in treated plants. The roots of treated plants accumulated higher concentrations of sodium and chloride than did shoots. The accumulation of sodium and chloride was accompanied by an increase in magnesium and calcium and a decrease in potassium in the roots, while the levels of potassium increased in the leaves. CT water altered gas exchange and water potentials in seedlings, and resulted in a decrease in chlorophyll's a and b. The results suggest that the mechanisms of salt resistance in red-osier dogwood seedlings involve the restriction of sodium transport from roots to shoots.

Environmental Pollution↗
PubMed2001

What role do nurses play in Type 2 diabetes care in the community: a Delphi study.

OBJECTIVES: To identify the views of nurses on their current and future roles in care in the community for people with Type 2 diabetes. METHOD: A two-round Delphi study was used to elicit, and assess consensus on opinions from random samples of practice nurses, with a substantial role in the management of diabetes patients and diabetes specialist nurses. Both groups had defined levels of expertise in diabetes care and worked in Great Britain. The study instrument in round one comprised a questionnaire with 10 statement headings inviting opinions on the nursing role in the management and care of people with Type 2 diabetes. In the second round levels of agreement were elicited from responders on collated opinions from round one. The initial questionnaire also included closed questions to obtain a profile of current care delivered. RESULTS: Responders were 97 practice nurses and 69 diabetes specialist nurses with second round response rates of 93% and 86%, respectively. The 47 themes raised could be grouped under headings of clinical practice, responsibility, communication, knowledge, education/experience, rewards, and patients' roles. Many were common to several statements and both nurse groups. The level of agreement on the themes fed back was high, 85% of the 165 items achieved greater than 80% agreement. Agreement occurred for factors relating to clinical effectiveness, audit, knowledge, education and experience. Dissent occurred both within and between individual nurse groups on issues of responsibility, prescribing, service delivery, resources, and patient factors. CONCLUSIONS: This Delphi study has identified key areas of consensus on the management of care for people with Type 2 diabetes in the community but also areas in which further work needs to be carried out to understand the differences found. Many of the discordant items relate to the separate roles and associated issues of the two nurse groups.

Attitude of Health Personnel↗
PubMed2000

Disease and gill lesions in yellow perch (Perca flavescens) exposed to oil sands mining-associated waters.

Adult yellow perch were stocked into experimental ponds designed to test the biological effects of aquatic reclamation alternatives currently being pursued by the oil sands mining industry. Water-quality characteristics of oil sands-influenced water in the experimental ponds included increased salinity and elevated trace organics associated with raw oil sands (bitumen). After 3 and 10 months of exposure to affected waters, perch gross pathologies including severe fin erosion and virally induced tumors were observed in exposed individuals. Gill histopathology revealed large aneurysms accompanied by a proliferation of chloride and epithelial cells in the interlamellar spaces. Gill pathologies were not paralleled by a decrease in plasma sodium, calcium, or chloride. The frequencies of gross pathologies and gill changes were correlated to the concentrations of the oil sands-related compounds. As inorganic and organic compounds associated with oil sands activities are highly intercorrelated, and the observed lesions and changes are not diagnostic of particular toxicants, it was not possible to isolate the causative chemical factor(s) responsible. The incidence of observed lesions and gill pathologies could not be conclusively linked to increased mortality rates observed in the exposed populations. Evidence of recovery in the pathologies was observed between 3 and 10 months of exposure, coincident with a stabilization in population numbers.

Animals↗
PubMed2000

The Prince Edward Island Conceptual Model for Nursing: a nursing perspective of primary health care.

The philosophy of primary health care (PHC) recognizes that health is a product of individual, social, economic, and political factors and that people have a right and a duty, individually and collectively, to participate in the course of their own health. The majority of nursing models cast the client in a dependent role and do not conceptualize health in a social, economic, and political context. The Prince Edward Island Conceptual Model for Nursing is congruent with the international move towards PHC. It guides the nurse in practising in the social and political environment in which nursing and health care take place. This model features a nurse/client partnership, the goal being to encourage clients to act on their own behalf. The conceptualization of the environment as the collective influence of the determinants of health gives both nurse and client a prominent position in the sociopolitical arena of health and health care.

Family Nursing↗
PubMed2000

Diabetes care delivery in the community.

Specialist nurses and practice nurses were asked about the future care and management of Type 2 diabetes. Consensus was high on issues such as audit, evidence-based practice, experience and record keeping. There were differences in opinion about nurse prescribing, teamwork, professional responsibility and education/training.

Adult↗
PubMed1999

Identification of permanent hearing loss in children: are the targets for outcome measures attainable?

A collaborative nine-centre study was designed to follow the routes to identification of all children up to the age of seven years newly diagnosed with permanent hearing impairment (> or = 50 dB HL) during the period 1993-1994. Ages of identification were compared with the standards set by the National Deaf Children's Society (NDCS), ascertaining whether these targets could be achieved with current service provision. Of the 126 children identified, 104 had congenital sensorineural hearing loss: 19% were identified by the age of six months and 39% by their first year. These results fall short of the NDCS targets of 40% and 80%, respectively, and point to the need for modifications of current practice, such as the introduction of universal neonatal screening.

Audiometry, Pure-Tone↗
PubMed1998

Resource Intensity Weights and Canadian hospital costs: some preliminary data.

Different types of inpatients "consume" differing amounts of hospital resources, and it is important to be able to measure these differences in resource consumption. An equitable methodology for funding hospitals must take into account differences in case mix between facilities. An ability to examine these differences in case mix and resource utilization allows hospitals to focus efforts to improve efficiency. A standardized methodology for measuring resource consumption is critical to funding and resource allocation both at a global and organizational level. This study was undertaken to determine whether or not the Canadian system for measuring resource consumption, Canadian Institute for Health Information (CIHI) RIWs, was reflective of the relative cost differences between inpatient cases at the Greater Victoria Hospital Society (GVHS) and to identify RIWs with a significant difference in comparison to GVHS cost weights. A regression analysis was performed on the more than 30,000 inpatient cost profile records from the GVHS 1995-96 cost and patient activity data. The scope of the analysis was restricted to the 424 Case Mix Groups (CMGs) that had a minimum composition of five patient profiles. Comparisons of GVHS cost weights to CIHI RIWs yielded mostly positive results. With the noted exception of about 20 CMGs, there was a high correlation between the CIHI RIW and the GVHS actual cost weights. Hence, the GVHS cost weights can be viewed with confidence as representative of the relative cost differences between typical RIW value CMGs and actual costs.

British Columbia↗
PubMed1997

p53, c-erbB-2 and nm23 expression have no prognostic significance in primary pulmonary adenocarcinoma.

OBJECTIVE: We analysed nm23, c-erbB-2 and p53 protein expression in lung adenocarcinoma in relation to clinicopathological status and patient survival, to elucidate any potential prognostic value. Published reports suggest that high p53 and c-erbB-2 protein expression and loss of nm23 protein expression are associated with poor prognosis. METHODS: A total of 162 pulmonary adenocarcinomas resected between 1980 and 1991 were stained using monoclonal antibodies to nm23 (NCL-nm23), c-erbB-2 (NCL-CB11) and p53 (DAKO Do7). Antigen retrieval was by microwave heating and bound antibody was visualised using standard immunohistochemical methods. Staining was scored by two observers blinded to tumour status and patient survival. RESULTS: Of the tumours, 101/162 (62.3%) exhibited high-level p53 expression, 30 (18.5%) showed high-level c-erbB-2 membrane staining, and 77 (47.5%) demonstrated loss of nm23 positivity. The influence of T and N status and disease stage on postoperative survival was as expected. The predicted effect on patient survival of nm23, c-erbB-2 or nm23 protein expression suggested by previous studies was not verified by our work. This was true both overall and for groups within the same T or N status or stage. CONCLUSION: Immunohistochemical assessment of the nm23, c-erbB-2 and p53 proteins using the above monoclonal antibodies does not have value as an independent prognostic indicator in pulmonary adenocarcinoma.

Adenocarcinoma↗
PubMed1997

Diet-induced changes in liver and bile but not brain fatty acids can be predicted from differences in plasma phospholipid fatty acids in formula- and milk-fed piglets.

The fatty acid composition of plasma phospholipids differs between infants fed formula and infants fed human milk, but the extent to which this is accompanied by differences in tissue phospholipid fatty acids is unclear. This paper describes analysis of plasma, liver and brain fatty acids from piglets fed one of seven formulas, varying in saturated, monounsaturated, (n-6) and (n-3) fatty acids or sow milk from birth for 18 d. Bile fatty acids were analyzed because they are secreted from liver and may be an important source of fatty acids for intestinal lipoprotein synthesis. The results were used to determine the relation between diet-related differences in plasma phospholipid fatty acids and those in brain, liver and bile. Where significant associations were found, prediction limits were constructed to assess the usefulness of analysis of plasma phospholipid fatty acids to predict diet-induced changes in tissue fatty acids. The proportions (g/100 g fatty acids) of 16:0, 18:0, 18:1, 18:2(n-6) and 20:4(n-6) in plasma phospholipids were significantly associated with the proportions of the same fatty acids in liver and bile, but not brain. The results show a reasonably precise, predictable association between plasma and liver, and plasma and bile fatty acids. Brain 20:4(n-6) and 22:6(n-3), in contrast, were not reliably associated with plasma phospholipid 20:4(n-6) and 22:6(n-3) for piglets fed milk or formula providing about 1.5% energy as 18:3(n-3).

Animal Feed↗
PubMed1997

Dose-related effects of dietary iron supplementation in producing hepatic iron overload in rats.

The influence of varying the level of supplemental dietary iron on the development of hepatic iron overload was examined in rats. Two days after giving birth, Porton rats were fed a diet supplemented with 0, 0.5, 1 or 2% carbonyl iron, to institute dietary iron supplementation to the young via breast milk. After weaning, the offspring continued to receive the assigned diet until 32 weeks of age. Liver biopsies were taken from some rats at 8, 16 and 24 weeks of age and from all rats at 32 weeks of age, for assessment of iron overload. For both male and female rats, hepatic iron content was increased in a dose-related manner by feeding supplemented diet. Hepatic iron content of male rats tended to reach a plateau after 8, 16 weeks of supplementation, while that of female rats continued to rise throughout the experimental period, such that the hepatic iron content of female rats was 2.8-fold that of similarly treated males at 32 weeks of age. Iron supplementation was associated with only moderate retardation of growth. By choosing an appropriate level of iron supplementation, good (grade III-IV) hepatic iron loading can be achieved with minimal adverse effects on the animals' overall health.

Animals↗
PubMed1996

Reduction of extraneural scarring by ADCON-T/N after surgical intervention.

The effects of ADCON-T/N (Gliatech, Inc., Cleveland, OH), a carbohydrate polymer gel, on peripheral nerve scarring and regeneration were studied in rodents undergoing three types of surgical intervention. Procedure I involved external neurolysis of the sciatic nerve from surrounding tissues and separation of its tibial and peroneal components. Procedure II involved the addition of an abrasive injury. Procedure III involved transection and suture anastomosis of the tibial component. ADCON-T/N or a control gel was locally applied in a blind fashion. Additional animals received no gel, as a further control. Animals underwent second operations 4 weeks after Procedures I and II and 6 weeks after Procedure III. The surgical sites were evaluated using a numerical grading scheme to assess wound healing, sciatic nerve adherence to surrounding tissues, and separability of its tibial and peroneal components. Animals receiving ADCON-T/N demonstrated reduced nerve adherence to surrounding tissues and enhanced separability of the tibial and peroneal components, compared with animals receiving control gel or no gel. Quantitative histological analysis revealed a statistically significant reduction in the amount of dense scar tissue surrounding nerves treated with ADCON-T/N. No evidence of nerve toxicity caused by ADCON-T/N was noted. Counts of regenerating myelinated axons in animals undergoing nerve transection and suture repair did not statistically differ in treated and untreated animals. In conclusion, ADCON-T/N seems to be both safe and effective in reducing extraneural scar formation after peripheral nerve surgery and local trauma.

Animals↗
PubMed1996

Physical fitness and its relationship to other indices of health status in children with chronic arthritis.

OBJECTIVE: To compare aerobic and anaerobic fitness of a group of children w-th chronic arthritis with that of healthy controls, and to explore the relationship between physical fitness and other indices of health status in these children. METHODS: Thirty-one children aged 8 to 17 years with chronic arthritis of varying type and severity and 16 physically healthy controls participated in the study. Using a cycle ergometer, aerobic fitness was assessed by measuring peak oxygen uptake achieved in a 15 s period during exercise to volitional fatigue. Anaerobic fitness was assessed by measuring peak power in the legs in a 5 s period and total work completed (Wingate test). Joint pain experienced over the week before testing and during testing was measured using a 10 cm visual analog scale. Self-esteem was measured using the Self Perception Profile for Children Questionnaire. RESULTS: There were no significant differences between mean peak O2 uptake or mean peak anaerobic power for patients and controls; however, the mean values for both controls and patients were significantly lower than reported values for healthy children. Peak O2 uptake controlled for age, sex, and sum of skinfolds was negatively associated with disease severity, measured by physician global assessment (p = 0.04), but peak power was not. Neither aerobic nor anaerobic fitness were associated with disease activity measured by physician global assessment or active joint count, or with disease duration. There was a tendency for children with active arthritis to experience less pain during fitness testing than over the previous week (p = 0.06). Testing did not seem to exacerbate joint symptoms. Self-ratings of athletic competence were significantly correlated with peak O2 uptake achieved for children with arthritis (r = 0.43, p = 0.02), but not for controls. Global self-esteem was moderately correlated with self-rated athletic competence in controls (r = 0.49, p = 0.09), but was not in children with arthritis. CONCLUSION: In this sample of children, most of whom had limited joint involvement, we failed to demonstrate significant group differences in fitness between patients and controls. Disease severity may be related to fitness levels, but psychosocial factors may perhaps be more important determinants of fitness. Children with arthritis seem to have realistic perceptions of their own physical capabilities, and even those children who are less fit and perceive themselves as having less athletic competence do not appear to have lowered self-esteem.

Adolescent↗
PubMed1995

Differential macrophage responses in the peripheral and central nervous system during wallerian degeneration of axons.

We characterized quantitatively the macrophage response following axonal injury in both the peripheral (PNS) and central nervous system (CNS) of adult mammals. A monoclonal antibody (ED-1) which stains monocytes, macrophages, and activated microglia was employed. In one model, Wallerian degeneration of the sciatic nerve was studied. An increase in the number of macrophages was seen as early as 1 day following nerve transection. Macrophage number increased synchronously along the length of degenerating nerve over a 21-day period. In a second model, transection of a spinal dorsal sensory root allowed us to compare and contrast the macrophage response along the PNS and CNS portions of a single axonal pathway. An increased number of macrophages restricted to the PNS portion of this pathway was seen by 3 days and continued to increase over a 14-day period. Myelin breakdown occurred in association with an increase in the number of macrophages by 3 days in the PNS but not the CNS portion of the degenerating dorsal root axon pathway. Low-affinity nerve growth factor receptor immunohistochemical staining increased by Day 1 in the PNS but not the CNS portion of this pathway, occurring prior to the invasion of macrophages. In both models, the morphology of infiltrating macrophages changed over time from small slender ramified cells to large elongated multivacuolated cells. In conclusion, our results demonstrate that the macrophage response during Wallerian degeneration of axons in adult mammals is much more rapid and robust in the PNS, where axonal regeneration occurs, than in the CNS, where axonal regeneration is far more limited.

Animals↗
PubMed1992

Diabetes care.

Providing good quality diabetes care is complex but achievable. Many aspects of the care do not require high tech medicine but, rather, good organisation. Diabetes is a costly disease, consuming 1500 pounds per diabetic patient per year versus 500 pounds on average for a non-diabetic member of the population in health service costs. Investment now in good quality diabetes care is sound: patients will benefit from a better quality of life associated with a reduced incidence of the complications of diabetes and the direct costs to the health service in treating these complications and the indirect costs to employers will be reduced. Physical and clinical assessments--measurements of blood glucose and glycosylated haemoglobin concentrations, weight, and blood pressure and assessment of eyes, kidneys, feet, and heart--are clearly important, but quality must include consideration of people and their reactions to life and diabetes--a lifelong entanglement--for which much more support should be provided.

Diabetes Mellitus↗