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Biomedical subjects

S Warren

Publications and source records attributed to S Warren.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

Arthroscopic mosaic arthroplasty in the equine third carpal bone.

OBJECTIVE: To investigate survival and function of autogenous heterotopic osteochondral grafts in a site where injuries are common. STUDY DESIGN: Three osteochondral grafts were harvested arthroscopically from the femoropatellar joint and transplanted to the third carpal bone (C(3)). Nine months later, histologic, histomorphometric, and biochemical comparisons were made between the transplanted grafts in C(3) and tissue adjacent to the recipient site, the opposing radial carpal bone (C(r)), the donor site in the femoropatellar joint, and the sham-operated contralateral C(3). ANIMALS: One mixed-breed pony and 5 Standardbred horses aged 3 to 8 years old. METHODS: Using instruments modified for equine use, four 4.5-mm-diameter osteochondral grafts were harvested arthroscopically from the distal aspect of the lateral trochlea of the right femur and inserted into the radial facet of the right third carpal bone. The fourth graft was kept as a donor-site control sample. Three months later, regular exercise was started and at 6 months, repeat arthroscopy was conducted to evaluate healing. The horses were euthanatized 9 months after transplantation, and comparisons were made between the grafts, opposing radial carpal bone, and contralateral third carpal bone. The assessment criteria included paravital staining, a modified Mankin scoring system, and biochemical analyses for collagen type, total collagen content, and sulfated glycosaminoglycan concentration. RESULTS: All horses were sound 21 days' postoperatively. At 6 months, all 18 grafts were intact but somewhat soft and opaque compared with surrounding carpal cartilage. Nine months' postoperatively, the bony portions of the grafts were well integrated with the recipient sites, but 6 grafts had histologic evidence of cartilage degeneration. From biochemical analysis of grafts, there was little or no new repair tissue invading the experimental sites, but sulfated glycosaminoglycan (proteoglycan) loss from the transplanted cartilage was marked. CONCLUSIONS: Heterotopic transfer of osteochondral grafts from the distal aspect of the lateral femoral trochlea to the third carpal bone is feasible with minor modifications of human mosaic arthroplasty instruments. The bony portion of the osteochondral grafts was quickly remodeled to provide subchondral support to the transplanted articular cartilage. The loss of proteoglycan from the transplanted cartilage indicates that the grafts might have been injured during harvesting or insertion, or, more likely, did not remodel to meet the demands of a new biomechanical environment. CLINICAL RELEVANCE: These findings suggest that arthroscopic resurfacing of focal osteoarticular defects will not be successful in the long term unless donor and recipient sites can be matched with respect to cartilage thickness, biochemical constituents, and physical properties. Mosaic arthroplasty may be indicated in selected cases in which no other options exist to create a confluent cartilage-covered surface.

Animals↗
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Innovative dementia care: functional status over time of persons with Alzheimer disease in a residential care centre compared to special care units.

Residential care centres (RCCs) for persons with Alzheimer disease are increasing worldwide, but there are few studies that compare the functional outcomes of RCC residents to residents of other types of continuing care settings. This study compared residents of the first Canadian RCC on physical, cognitive, behavioural and emotional functioning 6, 12 and 18 months after admission to residents of special care units (SCUs) operated by the same continuing care provider. SCU residents were initially functioning lower than RCC residents on most outcome measures and these differences persisted over time. Resident functioning declined over time regardless of care setting and, when the initial status was controlled for, the rates of decline were similar. However, RCC residents experienced greater independence/freedom of choice, fewer physical or psychotropic medication restraints and were more active, which may have enhanced their quality of life.

Accidental Falls↗
PubMedDate not supplied

Parental ancestry and risk of multiple sclerosis in Alberta, Canada.

Self-reported population ancestry data for the 19 census divisions (CDs) of Alberta, Canada, were correlated with multiple sclerosis (MS) prevalence rates in those divisions, for men and women separately; and parental ancestry was compared between a group of MS patients and controls attending the University of Alberta MS Clinic. At the CD level, there was a positive correlation between single Scandinavian ancestry and MS prevalence in men, but this was not confirmed in the case-control comparison. The case-control comparison indicated an excess risk of MS associated with single non-specific European as opposed to British ancestry in men only. When paternal versus maternal ancestry was considered separately, there was an excess risk of MS associated with non-specific European as opposed to British ancestry for both men and women, but on the father's side only. Aboriginal ancestry was negatively associated with MS prevalence at the CD level in both men and women; and no MS patients with aboriginal origin were among cases assembled through the MS clinic.

Canada↗
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Skeletal and tissue lesions resulting from exposure to radium and fission products.

The chief effects of absorbed radionuclides and external radiation are radiation osteitis, disturbed bone growth, myelofibrosis and bone tumors. The lesions are dependent in part on localization and character of the radiation and in part on dose. Data on radium have been derived from dial painters, radium chemists and those treated some years ago by oral or parenteral administration.

Aged↗
PubMedDate not supplied

Measuring long-term outcome after traumatic brain injury.

We report the results of the first stage of development of an instrument to measure long-term functional outcome after traumatic brain injury. The instrument focuses on both the person with a disability and the impact on the family caregiver. We illustrate the early stages of instrument development, focusing on one approach to standardized reviewer feedback to evaluate content validity. The results of the pilot testing are discussed in terms of: purpose, instrument construction, and clinical utility. While the complete details of the instrument are not presented, example items are used as illustration. A number of methodological issues in instrument development in rehabilitation are described including the logistics of reviewer feedback, the use of family caregivers in instrument development and the reliability of self-report in brain-injured population.

Activities of Daily Living↗
PubMedDate not supplied

Is breast cancer a result of endocrine targeting? (How women differ from rats or mice).

Parabiosis of female rats with castrate males or oophorectomized females produces carcinoma of the breast in the majority of intact females. When unilateral nephrectomy of each partner is added to the procedure, the incidence is 100 percent. Radioimmunoassays for luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, estradiol and progesterone have been performed on the sera of these rats. The pathogenesis of the breast carcinomas is discussed in the light of these results. An attempt to weigh various factors thought to be involved in causing human and experimental rat cancer of the breast suggests significant differences of a quantitative nature.

Animals↗