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Biomedical subjects

N J Stewart

Publications and source records attributed to N J Stewart.

At least 19 recordsLinked to original sources
PubMed2005

Possible differences in pathogenicity between cane toad-, frog- and platypus-derived isolates of Mucor amphibiorum, and a platypus-derived isolate of Mucor circinelloides.

Platypuses (Ornithorhynchus anatinus) in the north of the island state of Tasmania, Australia, suffer from a serious disease called ulcerative mycosis, which is responsible for high morbidity and, presumably, mortality rates in areas where it occurs. The disease is caused by the dimorphic fungus Mucor amphibiorum, which is also found in Queensland, New South Wales and Victoria. However, it does not cause disease in platypuses in those states. It has been previously reported that a closely related fungus, Mucor circinelloides, may also be capable of causing this disease. This paper describes pathogenicity trials involving cane toads (Bufo marinus) as the experimental model. The toads were infected with either Tasmanian, platypus-derived M. amphibiorum, West Australian, frog-derived M. amphibiorum, Queensland cane-toad-derived M. amphibiorum or Tasmanian platypus-derived M. circinelloides. The Tasmanian isolates of M. amphibiorum were more likely to cause a serious, long-term infection than were Queensland or West Australian isolates, and (+) mating types caused a more serious infection than the (-) mating type. The isolate of M. circinelloides was incapable of infecting the toads, lending further weight to the theory that it represents an environmental contaminant. The results suggest that an endemic strain of M. amphibiorum has mutated and become pathogenic to platypuses. Alternatively, a pathogenic strain of M. amphibiorum may have been introduced into Tasmania, where it is infecting a naïve population.

Animals↗
PubMed2005

Work stress and physical assault of nursing aides in rural nursing homes with and without dementia special care units.

PURPOSE: This study compared nursing aides (NAs) employed in rural nursing homes with and without dementia special care units (SCUs) on (1) exposure to and distress from disruptive behaviours exhibited by residents, (2) job strain and (3) physical assault. DESIGN AND METHODS: The data were drawn from a larger study conducted in Saskatchewan, Canada, in which all rural nursing homes of < or = 100 beds that had an SCU were matched to same-sized rural facilities with no SCU. Nursing aides (n = 355) completed a mailed survey questionnaire. RESULTS: Nursing aides employed in nursing homes with an SCU reported significantly less frequent exposure to disruptive behaviours (including aggressive and aversive behaviours) than NAs in non-SCU facilities, less distress when these behaviours were directed toward them, less exposure to aggressive behaviour during caregiving, lower job demands and lower job strain. There was a trend toward increased risk of being assaulted in the last year associated with being in a non-SCU facility. Having a permanent position, increased job strain, and feeling inadequately prepared for dementia care were significantly associated with higher risk of being assaulted. In the SCU facilities, NAs who worked more time on the SCU reported more assaults but less distress from disruptive behaviour, lower psychological job demands, lower job strain and greater work autonomy. IMPLICATIONS: Providing more dementia care training and reducing job demands and job strain may help to reduce work-related stress and physical assault of nursing aides employed in nursing homes.

Adult↗
PubMed2004

Capacity building in rural health research: a Canadian perspective.

INTRODUCTION: The need to build capacity in rural health research is recognized in Canada. During its formative stage, the Canadian Rural Health Research Society (established in 2002), performed a nation-wide survey of the research teaching and training opportunities available to students interested in rural and remote health issues. Intended as a cross-sectional 'snapshot,' and to provide base-line data, the survey involved a comprehensive list of educational programs in health and science disciplines at all Canadian Universities offering graduate-level programs. The present project report gives an overview of the results, documenting the current strengths, but also the noticeable gaps that exist. METHODS: Data were collected via an Internet survey, developed according to Dillman's email survey design principles. Although multiple contacts are recommended, due to time constraints only two were made. The instrument included both open- and closed-ended questions designed to determine institutional commitments to rural health research training generally, as well as specific information about course offerings, infrastructure supports for students, financial assistance for studying specific topics, and future plans. Health was defined broadly and included a number of disciplines beyond those usually considered under the health rubric. Individuals in administrative positions for 462 programs in 24 distinct disciplines at 56 institutions were sent the survey. Responses were received from 120 programs at 40 universities. Due to budget constraints the instrument was not translated into French. Descriptive statistics were used to analyse the data, combined with a thematic analysis of written comments. Ethical approval was obtained from the Lakehead University before the study was conducted. RESULTS: Despite the fact that one-third of Canadians live in rural, remote and northern areas, there is a paucity of research that addresses rural health issues. Moreover, Canadian universities have very limited rural health offerings in their curricula. There are few formal courses available on rural health topics generally or rural health research specifically. Although students can take rural-related independent studies or reading courses, very few actually take advantage of the option. Of all disciplines, nursing faculty are most likely to pursue rural health research and to offer rural health courses. Moreover, nursing faculty most often indicate an intention to expand their rural health offerings. In the social sciences, geography and environmental science programs, relatively few students choose to study rural health. Similarly, in medicine, the number of students exploring rural health issues is small. There is some specific financial assistance available to students who are interested in rural health research and, as well, they have access to general pools of funding. CONCLUSION: The survey results demonstrate the limitations of current educational programs. However, they also indicate areas of potential growth and show widespread interest in increasing the offerings available at universities across Canada. The article concludes by giving an overview of the mandate and initiatives being taken by the new research society to augment training, and to enhance student participation. In addition, it notes the positive developments linked to a new Strategic Plan by the Canadian Institutes of Health Research (CIHR) to enhance rural health research in Canada.

Journal Article↗
PubMed2004

Evaluating rural nursing home environments: dementia special care units versus integrated facilities.

Although one in four seniors currently lives in a rural area, little is known about the capacity of rural nursing homes to provide specialized dementia services. The physical and social environments are increasingly recognized as important factors in the quality of life and functional ability of persons with dementia. This study compared eight rural nursing homes (those located in centres with populations < or =15,000) that had created dementia Special Care Units (SCUs) to eight same-sized rural nursing homes that did not have SCUs. Outcomes were assessed in relation to residents, staff, family members, and the environment. In this paper we describe the overall study design and findings from the environmental assessment. Analysis of variance (ANOVA) was used to compare the SCU versus non-SCU environments on the nine dimensions of the Physical Environmental Assessment Protocol (PEAP), which was used to assess the physical environment. The SCUs were more supportive on six dimensions: maximizing awareness and orientation, maximizing safety and security, regulation of stimulation, quality of stimulation, opportunities for personal control, and continuity of the self. Analysis of variance was also used to compare the groups on the six subscales of the Nursing Unit Rating Scale (NURS), which assesses the social environment of dementia care settings. The SCUs were more supportive on the Separation and Stimulation subscales, indicating that SCUs had greater separation of residents with dementia from other residents for activities of daily living and programming, and better control of non-meaningful stimulation.

Aged↗
PubMed2002

Accumulation of persistent organic pollutants in Tasmanian platypus (Ornithorhynchus anatinus).

Tailfat samples were collected from 56 platypuses, 38 male and 18 female in Tasmania. No statistically significant, nor apparent, differences between the sexes were found for tailfat lipid levels and DDT and its metabolites. Lindane and PCB concentrations in tailfat lipid. Apparently--but not statistically--significantly different levels of DDT and its metabolites. Lindane and PCB concentrations were found in animals from different geographic regions of the State. Higher concentrations of DDT and its metabolites and Lindane were related to the intensity of agricultural activity and elevated PCB levels were mainly found in animals from zones with industrial and hydroelectric developments.

Adipose Tissue↗
PubMed1999

The physical environment of special care units: needs of residents with dementia from the perspective of staff and family caregivers.

To manage the care of increasing numbers of residents with dementia, many long-term care facilities have created special care units (SCUs) designed to meet the unique needs of this group. This article describes results of the qualitative component of a larger research project examining environment-behavior relationships in dementia care settings. Eighteen indepth interviews were conducted with 9 staff and 9 family members of SCU residents. Thematic analysis was conducted using grounded theory techniques. Participants described residents' needs in relation to both the physical and social environments. This article focuses on the five areas of need identified by participants in relation to the physical environment: safety, homelike setting, optimal stimulation, cues, and options for privacy and social interaction.

Aged↗
PubMed1999

Caregiver distress. Related to disruptive behaviors on special care units versus traditional long-term care units.

The link between staff stress and exposure to disruptive behaviors is an important issue in long-term care settings. This study compared the perceptions of two groups of formal caregivers (staff) regarding their distress from the behaviors of residents in their care. Staff on special care units for dementia were less distressed with disruptive behaviors than comparable staff on traditional units, although they reported higher exposure to these behaviors. These results were related to different perceptions of intent to harm and expectations of physical aggression as "part of the job." Implications for nursing include education and support for staff to enhance the quality of life for residents and staff on units where disruptive behaviors occur.

Adolescent↗
PubMed1999

Isolation of Mucor circinelloides from a case of ulcerative mycosis of platypus (Ornithorhynchus anatinus), and a comparison of the response of Mucor circinelloides and Mucor amphibiorum to different culture temperatures.

The fungus Mucor circinelloides was isolated from a platypus (Ornithorhynchus anatinus) suffering from ulcerative mycosis. On horse blood agar at 20, 25 and 30 degrees C, the fungus formed sphaerule-like bodies, a morphology previously associated with Mucor amphibiorum, the species thought to be responsible for the disease in platypus. A biopsy taken from the ulcer was fixed, cut and stained. The sections were compared with sections taken from other platypuses suffering from ulcerative mycosis, and from which M. amphibiorum had been isolated. There were no discernible differences between the sphaerule-like bodies found in any of the sections. The presence of sphaerule-like bodies in tissues of ulcerated animals can, therefore, probably no longer be relied upon as a definitive method for the diagnosis of M. amphibiorum infection. It is possible that M. circinelloides is either a primary or a secondary pathogen of platypuses, and further work is required to resolve this point. The isolate of M. circinelloides grew at temperatures up to 38 degrees C, with an optimum temperature for growth of 30 degrees C. Of six isolates of M. amphibiorum derived from both platypus and amphibians, two grew well at 38 degrees C. The growth of one of these isolates at elevated temperatures may be explained by the hot climate of the area in Queensland in which it was found. All of the isolates tested had maximum temperatures for growth in excess of the body temperature of platypuses (32 degrees C).

Animal Diseases↗
PubMed1998

Disease conditions and subclinical infections of the platypus (Ornithorhynchus anatinus).

Before the arrival of European settlers in Australia, the platypus, Ornithorhynchus anatinus, probably suffered from little disease. Among other things, European settlement has involved substantial environmental perturbation, introduction of large predators, introduction of motor vehicles and translocation of potential pathogens. As a result, platypuses are now killed by motor vehicles, dogs, foxes and discarded plastic litter. Information programmes targeting appropriate segments of the public would help reduce these unnecessary deaths. The enigmatic disease, ulcerative mycosis, caused by Mucor amphibiorum, has been the subject of scientific investigation in Tasmania for the past 15 years. The apparent recent acceleration in its spread has sounded a warning and more intensive investigation is warranted. The possibility that this pathogen has been translocated from subtropical to temperate Tasmania, Australia, with green free frogs in banana shipments further emphasizes the role of humans in threatening the welfare of the platypus. Recommendations are made in relation to appropriate measures that could be taken to ameliorate disease and trauma in this species.

Animal Diseases↗
PubMed1998

Bilateral emphysematous pyelonephritis.

In any diabetic patient being diagnosed or treated for pyelonephritis, it is important to exclude the diagnosis of emphysematous pyelonephritis, which carries a high mortality rate. The authors present an illustrative case of emphysematous pyelonephritis treated with antibiotics and emergency nephrectomy. The signs, symptoms, pathophysiology, diagnosis, and treatment of emphysematous pyelonephritis are discussed.

Abscess↗
PubMed1997

Differences in patellar tracking and knee kinematics among three different total knee designs.

Patellar complications are the primary reason for reoperation of the current condylar type designs. The aim of this study was to compare patellar tracking of various knee implant designs: Genesis II NexGen, and the P.F.C. Sigma Modular Knee System regarding trochlear groove center curvature. Nine unembalmed whole cadaveric lower extremities were used. The quadriceps and hamstrings were dissected into their individual muscles and loads were applied onto the muscles proximally based on the cross sectional area of the muscles. The three-dimensional kinematics of the patellofemoral and tibiofemoral joint of the intact knee were measured using a 3Space tracking system. Three implants (one from each company) were implanted onto the same cadaveric knee in random order consecutively. This was done to ensure consistency of the soft tissue constraints in influencing the amount of patellar tracking. Patellar rotation, patellar tilting, patellar lateral shift and patellar displacement in relation to groove center were measured. There was no significant difference between the intact knee and the various implants regarding patellar rotation and lateral shift. However, all three prosthetic designs showed a significant degree of lateral tilting when compared with the intact knee. At 60 degrees knee flexion, the normal patella was tilted laterally to 0.44 degree +/- 2.15 degrees as compared with the Genesis II patella at 4.75 degrees +/- 4.81 degrees, the NexGen patella at 4.85 degrees +/- 4.81 degrees, and the P.F.C. Sigma patella at 4.89 degrees +/- 3.79 degrees lateral tilt. There was no difference between the intact knee compared with the resurfaced patella in patellar displacement in relation to the groove center. This study suggests the relatively similar kinematic behavior between the implant designs as compared with the intact knees. However, additional modification of implant geometry may be required to help decrease the amount of patellar tilt.

Arthroplasty, Replacement, Knee↗
PubMed1995

Lymphangiosarcoma following mastectomy.

This study reviews 16 cases of lymphangiosarcoma of the upper extremity after mastectomy for breast cancer (Stewart-Treves syndrome) was done at the author's institution from 1970 to 1992. Lymphangiosarcoma was diagnosed an average of 10.6 years (range, 5.6-18 years) after the diagnosis of breast cancer. Presenting signs included a bruise (6 patients); increased swelling (4); a red, raised lesion (2); a palpable mass (2); a blister appearance (1); and a non-healing eschar with continual bleeding (1). After biopsy, surgical treatment included forequarter amputation (8 patients), wide excision with grafting (5), and above-elbow amputation (1). Local recurrence of the lymphangiosarcoma occurred on the chest wall in 11 of the 16 patients after an average of 10.9 months. Metastasis occurred in 11 patients. (Metastasis occurred in 1 patient without local recurrence, and 1 patient with locally recurrent lymphangiosarcoma died of breast cancer before evidence of metastatic lymphangiosarcoma.) There are 2 long-term survivors who have lived 9.3 and 6 years, respectively, since the operation. One had been treated with a forequarter amputation and the other with wide excision. Early recognition and surgical treatment seem to offer the only chance for long-term survival.

Adult↗
PubMed1994

Load affects remodeling of transplanted, autogenous bone-patellar tendon-bone segments in a rabbit model.

The question of whether or not load affects the remodeling of a transplanted autogenous free graft was addressed by removal of the patella-patellar tendon-tibial tubercle complex from the right knees of 15 New Zealand White rabbits. The tubercle was split, and the tendon was divided with each half trimmed to an equal width. The autograft complex was transplanted into a subcutaneous tunnel on the back of the rabbit. Controlled cyclic loads were applied via transcutaneous sutures to half of the graft, while the other half remained unloaded. The mechanical stiffness and strength and the cell density of loaded and unloaded halves of the autograft were measured in nine animals at 3 weeks and in six animals at 6 weeks. Five autografts from four additional rabbits served as unimplanted controls. An analysis of variance showed that the loaded portions of the autografts had a significantly higher failure strength (mean of 90%) and were significantly stiffer (mean of 62%) than the unloaded halves at 3 and 6 weeks. Failure strength was significantly greater (mean of 90%) at 3 weeks than at 6 weeks. The autografts were less stiff and had a lower failure strength than the unimplanted controls, with the greatest difference occurring in the unloaded segments at 6 weeks. Histology revealed that both loaded and unloaded segments demonstrated an increase in cellularity at 6 weeks compared with 3 weeks. This report introduces a model for the study of the effect of load on soft-tissue grafts and demonstrates that loading affects the remodeling process of a transferred autograft.

Animals↗
PubMed1994

Movement therapy with depressed inpatients: a randomized multiple single case design.

The relative lack of research on movement therapy in inpatient versus outpatient settings stems from the difficulty of conducting an interpretable study in clinical situations where multiple treatments exist. To control for the multiple treatment confound, this study used a randomized single-case experimental design with 12 replications. Results indicated that the movement therapy, which was designed to target the syndrome of a major depressive episode had a positive effect on mood across experiments (p < .001). From a clinical perspective, these results support the use of a movement program as adjunctive treatment, and challenge the view that movement is recreation but not therapy.

Adult↗
PubMed1994

Predictors of participation in a peer-led exercise program for senior women.

This study explored variables selected using the Interaction Model of Client Health Behavior (Cox, 1982) and their relationship to exercise group participation in seniors. Seventy-five women were surveyed from from two similar senior apartment buildings. Subjects' ages ranged from 65 to 88 years (M = 75.91, SD = 6.12). Discriminant function analysis was used to test the relationship of seven demographic and motivational variables to choice of exercise group participation. As hypothesized, significant predictors for all the women in both buildings were: a measure of competence, education, number of medications, building, and age. Two variables, income and marital status, did not emerge as significant predictors. Women more likely to attend an exercise group had greater competence in health matters, higher education, a lower number of medications, were living in building B, and were lower in age. Nurses who facilitate exercise groups for seniors in the community should be aware of the impact these variables could have on attendance.

Aged↗
PubMed1993

Maintenance of set force in anterior cruciate ligament grafts.

This study was undertaken to determine how accurately total graft force and load-sharing between graft segments could be set and maintained during augmented anterior cruciate ligament (ACL) reconstruction in the goat knee. Special procedures were developed to reduce the effect of tissue creep and to overcome difficulties in the setting of graft force. Five knees from goat cadavers were reconstructed using a bone-tendon-bone graft (PT) and a synthetic augmentation device (LAD). Prescribed levels of total graft force and load-sharing between the autograft and LAD were set under a standardized external joint load. Immediately after fixation, the set force declined an average of 9 and 3% in the LAD and PT, respectively. After three subsequent exercise sequences, the set forces fell from their initial level by an average of 25% for the LAD and 28% for the PT. An analysis of variance did not show the loss of force with exercise to be statistically significant. We conclude from this in vitro study that our method can be used to set forces in an ACL reconstruction with reasonable maintenance of load-sharing but that losses of approximately 30% of total graft force after exercise of the reconstructed joint are to be expected.

Animals↗