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Biomedical subjects

M Dunbar

Publications and source records attributed to M Dunbar.

At least 19 recordsLinked to original sources
PubMed2006

Clear not simple: an approach to community consultation for a maternal pneumococcal vaccine trial among Indigenous women in the Northern Territory of Australia.

PneuMum is a randomised controlled maternal vaccination trial, using 23-valent Pneumococcal Polysaccharide Vaccine (23vPPV) during the third trimester or at delivery compared to vaccination at 7 months post delivery. The primary outcomes are infant middle ear disease and nasopharyngeal pneumococcal carriage at 7 months of age. PneuMum is the first vaccine trial to be conducted among Indigenous people in the Northern Territory. We describe the study design and the approach taken to develop the PneuMum message in collaboration with key Indigenous stakeholders and then to communicate the PneuMum message with Indigenous communities and potential participants. We hope that these methods will provide a model for future research involving Indigenous communities to ensure Indigenous involvement in research and ultimate improvements in Indigenous health.

Adolescent↗
PubMed2001

Parathyroid hormone-related protein maintains mammary epithelial fate and triggers nipple skin differentiation during embryonic breast development.

Prior reports have demonstrated that both parathyroid hormone-related protein (PTHrP) and the type I PTH/PTHrP receptor are necessary for the proper development of the embryonic mammary gland in mice. Using a combination of loss-of-function and gain-of-function models, we now report that PTHrP regulates a series of cell fate decisions that are central to the survival and morphogenesis of the mammary epithelium and the formation of the nipple. PTHrP is made in the epithelial cells of the mammary bud and, during embryonic mammary development, it interacts with the surrounding mesenchymal cells to induce the formation of the dense mammary mesenchyme. In response, these mammary-specific mesenchymal cells support the maintenance of mammary epithelial cell fate, trigger epithelial morphogenesis and induce the overlying epidermis to form the nipple. In the absence of PTHrP signaling, the mammary epithelial cells revert to an epidermal fate, no mammary ducts are formed and the nipple does not form. In the presence of diffuse epidermal PTHrP signaling, the ventral dermis is transformed into mammary mesenchyme and the entire ventral epidermis becomes nipple skin. These alterations in cell fate require that PTHrP be expressed during development and they require the presence of the PTH/PTHrP receptor. Finally, PTHrP signaling regulates the epidermal and mesenchymal expression of LEF1 and (&bgr;)-catenin, suggesting that these changes in cell fate involve an interaction between the PTHrP and Wnt signaling pathways.

Animals↗
PubMed2000

Distinct roles for PI3K in proliferation and survival of oligodendrocyte progenitor cells.

Phosphoinositol 3-kinase (PI3K) is a downstream effector for multiple ligand-activated receptors and modulates cell responses through activation of its target protein kinase B (Akt). We examined the roles of PI3K-Akt signaling in a primary glial (oligodendrocyte) progenitor cell culture system that is ligand-dependent for cell proliferation, survival, and prevention of differentiation. We demonstrate that PI3K and Akt (Ser-473 phosphorylation) are activated in response to platelet-derived growth factor but not basic fibroblast growth factor-2 (FGF2) and that distinct forms of PI3K are activated in early progenitors and later-maturation pro-oligodendroblasts as identified by their sensitivity to wortmannin. By establishing conditions to examine effects on cell proliferation and survival independently, we demonstrate that PI3K is necessary for a full mitogenic response and that PI3K is also necessary for early progenitor survival. Our results therefore demonstrate that PI3K-Akt signaling independently regulates proliferation and survival, that the form of PI3K is distinct in early progenitors and pro-oligodendroblasts, and that FGF2 does not activate this pathway in either primary glial cell population.

Androstadienes↗
PubMed2000

Patient satisfaction after knee arthroplasty: a report on 27,372 knees operated on between 1981 and 1995 in Sweden.

During a validation process of the Swedish Knee Arthroplasty Register (SKAR), living registered patients were sent a questionnaire to ask if they had been reoperated on. This gave an opportunity to pose a simple four-point question with respect to patient satisfaction which 95% of patients answered. We analyzed the answers of patients operated on between 1981 and 1995 and found that only 8% of the patients were dissatisfied regarding their knee arthroplasty 2-17 years postoperatively. The satisfaction rate was constant, regardless of when the operation had been performed during the 15-year period. The proportion of satisfied patients was affected by the preoperative diagnosis, patients operated on for a long-standing disease more often being satisfied than those with a short disease-duration. There was no difference in proportions of satisfied patients, whether they had primarily been operated on with a total knee arthroplasty (TKA) or a medial unicompartmental arthroplasty (UKA). For TKAs performed with primary patellar resurfacing, there was a higher ratio of satisfied patients than for TKAs not resurfaced, but this increased ratio diminished with time passed since the primary operation. Unrevised knees had a higher proportion of satisfied patients than knees that had been subject to revision, and among patients revised for medial UKA, the proportion of satisfied patients was higher than among patients revised for TKA. We conclude that satisfaction after knee arthroplasty is stable and long-lasting in unrevised cases and that even after revision most patients are satisfied.

Arthroplasty, Replacement, Knee↗
PubMed2000

A confirmatory factor analysis of the Hospital Anxiety and Depression scale: comparing empirically and theoretically derived structures.

OBJECTIVES: To compare the fit of various factor solutions for the Hospital Anxiety and Depression scale (HAD; Zigmond & Snaith, 1983). DESIGN: A cross-sectional postal survey was used to collect the data from community-based participants in the West of Scotland Twenty-07 study. METHODS: The HAD scale, a 14-item self-administered measure of anxiety and depression, was completed by 2547 participants from three age cohorts (aged approximately 18, 39 and 58 years). Using confirmatory factor analyses four models suggested by prior exploratory factor analyses were compared to a model derived from Clark and Watson's (1991) tripartite theory of anxiety and depression. RESULTS: The model derived from the tripartite theory of anxiety and depression (with factors labelled negative affectivity, anhedonic depression and autonomic anxiety) produced the closest fit to the data. This model produced a good fit in all three cohorts although group comparisons suggested that there were variations in the strength of some factor loadings across the three age groups. A model that had a hierarchical arrangement of the three factors in the tripartite model was also produced. This model fit the data equally as well as did the 'flat' tripartite model. CONCLUSIONS: Three factors appear to underlie the HAD scale. Research is needed that examines whether or not using sub-scales based on these factors increases the ability of the HAD scale to detect cases of anxiety and depression.

Adolescent↗
PubMed1999

Marital food interaction and dietary behavior.

The objective of this investigation is to consider the role of family food interaction in healthful dietary activity. A theoretical model is proposed in which three sets of determinate variables are specified as leading to interaction in the family on food issues which, in turn, is predicted to have a positive effect on four indicators of dietary quality. 155 married couples from a midwestern US state were randomly selected and interviewed. The findings provide clear evidence of the importance of family food interaction for the quality of marital partners' diet. Also differences found between husbands and wives indicate that wives contribute more to husbands' dietary quality than the reverse, suggesting again the dominant status of wives in family food selection and preparation.

Adult↗
PubMed1999

Validation of the Swedish Knee Arthroplasty Register: a postal survey regarding 30,376 knees operated on between 1975 and 1995.

The Swedish Knee Arthroplasty Register is dependent on the participating clinics regarding accuracy of information. As the register is prospective, and since revision is used as the endpoint in survival analyses, it is important that all revisions of registered primary arthroplasties are reported. To validate the register, we sent a questionnaire to all living patients with 30,796 knees registered as having been operated on from 1975-1995. Of living patients, 99% could be located and 93% answered. We found that one fifth of the revisions had not been reported and that relatively fewer revisions were lost to follow-up during the first decade of the register than in the following years. To investigate whether the Patient Administrative System (PAS), a database based on ICD coding and run by the Swedish health authorities, could be used to locate missing revisions found by the postal survey, we compared this database with the Swedish Knee Arthroplasty Register. 84% of the missing revisions revealed by the postal survey were found by using this method. Hence after the survey and the use of the PAS to find unreported revisions in deceased and non-responding patients, we estimate that 94% of all revisions are accounted for. Apart from a generally higher cumulative revision rate, conclusions reported from the Register in recent years regarding survivorship seem to be unaffected by the underreporting.

Arthroplasty, Replacement, Knee↗
PubMed1997

Judicial case management and the custody and access assessment: melding the approaches.

BACKGROUND: The presence of the Unified Family Court, with procedures emphasizing judicial case management and settlement in custody disputes, provided an opportunity to combine these practices with those of a university hospital-based family court clinic experienced in the provision of custody assessments. Specifically, a process integrating the clinical custody assessment with the work of counsel and court procedures was developed. This format, incorporating the preparation of a clinical settlement conference brief, was then evaluated with emphasis on time management, outcome in relation to settlement or trial, and the effect of clinical assessment at critical points in the combined endeavour. METHOD: Seventy-two judicial referrals conducted using this format were reviewed. To assess efficiency, we determined time intervals to various points in the process and compared them to previous local practice. Settlement rates, recorded incrementally to mark each component's contribution, were compared with rates noted in the literature. Assessment functions were identified according to the point of resolution of the dispute and in a manner to facilitate comparison with previously published work. RESULTS: The format resulted in 50% of cases settling without trial in under 5 months, a minimum settlement rate of 50%, and confirmed the ability of clinical assessment to contribute flexibly to dispute resolution in several conciliation venues and at trial. CONCLUSIONS: Combining legal and mental health efforts can results in more efficient use of resources and a substantial diversion of cases from continuing litigation. While altering the process of clinical assessments enhances such findings, further work is required to assure appropriate selection criteria for various intervention formats.

Adolescent↗
PubMed1997

The sexual behaviour of international travellers at two Glasgow GUM clinics. Glasgow genitourinary medicine.

A survey of patients attending 2 Glasgow genitourinary medicine (GUM) clinics was conducted in 2 3-month periods in 1993 and 1994. Three hundred and twenty-five attendees who had travelled abroad in the preceding 3 months completed anonymous self-administered questionnaires about their sexual behaviour during these recent journeys abroad. There were 112 women and 213 men (185 heterosexuals and 28 homosexuals). Twenty-two (19.6%) women, 56 (31%) heterosexual men and 13 (42%) homosexual men had a sexual contact with a new partner while abroad. Of those who had had a new sexual contact abroad, 11 women (50% of those who had sex with a new partner) and 33 heterosexual men (59% of those who had sex with a new partner) were inconsistent users of condoms. Analysis of data found that homosexual and heterosexual men, and business travellers, are at increased risk of exposure to sexually transmitted diseases, including HIV infection, and should be targeted with safer sex health promotion prior to travel.

Adolescent↗
PubMed1995

The effects of caring on health: a community-based longitudinal study.

This paper begins with a critical review of studies which have examined the effects of caring on health. Most are shown to suffer from defects in sampling and design, so that the evidence for detrimental effects is suggestive rather than conclusive. The substantive part of the paper then utilizes data on a cohort of 55-year-olds to compare the health of carers with the health of non-carers and to examine changes in caring and health over a 3-year period. The comparison yields no systematic evidence of the deleterious effects of caring on health; indeed, if there is a tendency in the accumulated data, it is in the opposite direction i.e. that carers report better health and functioning than non-carers. It is suggested that part of the explanation relates to selection and self-selection and the longitudinal data reveals high volatility in caring status, even over a short time period. The paper goes on to examine sub-groups of carers considered to be at greater risk. There is no evidence that their health is compromised but the authors acknowledge weaknesses in the data and argue for a specially designed study. The paper concludes with a discussion of the findings and their implications for research, policy and practice.

Caregivers↗
PubMed1990

Hip dysplasia with bilateral ischiatic nerve entrapment in a dog.

Dysfunction of both ischiatic nerves was detected in a 5-year-old spayed Labrador Retriever with radiographic evidence of severe bilateral hip dysplasia. Marked hyperflexion of the hip and stifle was evident when the dog walked. Results of electromyography confirmed the ischiatic nerve involvement. At staged operations, both ischiatic nerves were found to be compressed between the sacrotuberous ligament and proliferative tissue around the hip. One year after surgery, electromyographic and physical findings were essentially normal.

Animals↗
PubMed1986

Development of an objective comedogenicity assay.

The rabbit ear comedogenicity assay is useful as a screening procedure for evaluating agents that come in contact with human skin. Controversy exists regarding the reliability of this assay because of differences in results from various laboratories. The subjective nature of the standard method of grading may also contribute to this variation. We use a more objective comedogenicity assay that utilizes increasing follicular orifice size on the rabbit ear as a measure of comedogenic activity. A generally linear increase in the degree of follicular orifice area was noted with several agents evaluated over a four-week application period. Further, a noninvasive Silastic elastomer mold was used to allow measurement of the same follicular orifice areas over time.

Acne Vulgaris↗
PubMed1986

Angiotensin II receptors in the kidney.

Angiotensin II (AngII) receptors have been localized in rat kidney by using the high-affinity agonist analog 125I-labeled [Sar1]AngII as a probe for in vitro autoradiography. Receptors were associated with four morphologically distinct patterns of distribution. First, a high density of receptors occurs in glomeruli. These are diffusely distributed, consistent with a mesangial localization. AngII receptor density shows a cortical gradient, which is highest in superficial and midcortical glomeruli and lowest in juxtamedullary glomeruli. Receptors associated with both superficial and deep glomeruli show down-regulation during low-sodium intake. Second, low levels of tubular AngII binding were seen in the outer cortex. Third, a very high density of AngII receptors occurs in longitudinal bands in the inner zone of the outer medulla in association with vasa recta bundles. Receptors in this site also show down-regulation during low dietary sodium intake. Fourth, a moderate density of receptors occurs diffusely throughout the inner zone of the outer medulla in the interbundle areas. These results suggest that AngII exerts a number of different intrarenal regulatory actions. In addition to the known vascular, glomerular, and proximal tubular effects of AngII, these findings focus attention on possible actions of AngII in the renal medulla where it could regulate medullary blood flow and thereby modify the function of the countercurrent concentrating system.

Angiotensin II↗
PubMed1984

Behavior of ewes and lambs subjected to restraint fostering.

The objective of this study was to investigate the development of maternal-filial social attachments between ewes and alien lambs using the technique of "restraint fostering." Forty-eight to 72 h after parturition, 22 Targhee -type ewes were separated from their natural lambs, placed in restraining devices ( stanchions ) and each exposed to a single alien lamb. After a period of 1 or 4 d of restraint, the ewes were subjected to five 10-min lamb acceptance tests over a 48-h period. The observer recorded butts and butt attempts by the ewe and successful and unsuccessful suckle attempts by the lamb. The ewe-lamb pairs were then housed in pens with other groups of ewes and lambs and observed intermittently for acceptance behaviors. Six of the 14 ewes restrained for 4 d and none of the eight ewes restrained for 24 h met the criterion for successful adoption within 48 h. After being housed in group pens, adoptions were achieved by three ewes in the 1-d group and an additional four ewes in the group restrained for 4 d. Ewes restrained for 24 h were significantly more aggressive toward fostered young than ewes restrained for 4 d. In addition, the proportion of successful suckling attempts was significantly lower for lambs fostered on ewes in the 1-d group. Both groups showed a decline in butts and butt attempts over successive acceptance tests, but while the proportion of successful suckling attempts declined for lambs housed with 1-d ewes, they increased over time for lambs fostered on ewes restrained for 4 d.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

In vitro autoradiographic localization of angiotensin-converting enzyme in rat brain using 125I-labelled MK351A.

A method has been developed to localize angiotensin-converting enzyme in tissues by in vitro autoradiography. The potent angiotensin-converting enzyme inhibitor, MK351A, was labelled with 125I and shown to exhibit saturable, high affinity, reversible binding to membrane fractions of rat lung and caudate-putamen. The radio-ligand bound with a T 1/2 2-3 min at 20 degrees C and dissociated with a T 1/2 of approximately 5 min on addition of excess unlabelled inhibitor. The potency of a series of converting enzyme inhibitors in displacing the radio-ligand closely paralleled their anticatalytic potency, strongly suggesting that the ligand labels the active site of converting enzyme. In vitro autoradiographic analysis using this system revealed a very high density of converting enzyme in rat lung, small bowel muocosa, adrenal zona glomerulosa, adrenal medulla and brain. In the brain, a discrete and characteristic distribution of the enzyme was observed. A very high density of converting enzyme was found in the choroid plexus, subfornical organ, caudate-putamen, globus pallidus and substantia nigra. The enzyme was also localized in discrete regions of the hypothalamus, thalamus, amygdala, brain stem and cerebellum.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1983

Treatment of canine blastomycosis with ketoconazole.

Four dogs with blastomycosis were treated with ketoconazole, and good results were obtained in 3 of the 4 cases. Dogs that responded to treatment had manifested a variety of the clinical forms of blastomycosis (osseous, pulmonary, lymphatic, and ocular), and all lesions in the dogs abated. There were no clinical signs or clinicopathologic evidence of adverse drug reaction or toxicosis. The results of the study suggested that ketoconazole is effective for the treatment of canine blastomycosis.

Animals↗
PubMed1983

Development of a nutritional care plan for diabetic patients.

A nutritional care plan, encompassing all aspects of nutritional assessment, education, and follow-up was designed and implemented at the Victoria General Hospital in Halifax, Nova Scotia. The care plan was developed in response to the results of an audit on nutritional care of diabetic patients. It was designed to assure referral of all diabetic patients to clinical dietitians, set standards for care and its documentation, provide a teaching tool, and enhance communication between inpatient and outpatient nutrition services. The care plan was developed by the authors in committee and approved by the clinical dietitians and the medical staff at the Victoria General Hospital. The care plan format is described in detail. It has been in effect since March, 1982 with positive feedback reported by clinical dietitians. Reevaluation of care, charting, and referrals to outpatient nutrition services are planned. Additional care plans on other nutritional topics are planned for the future.

Diet, Diabetic↗