Search PubMed⌕ Search

Biomedical subjects

S O'Donnell

Publications and source records attributed to S O'Donnell.

At least 19 recordsLinked to original sources
PubMed2006

Strontium ranelate for preventing and treating postmenopausal osteoporosis.

BACKGROUND: Strontium ranelate is a new treatment for osteoporosis therefore, its benefits and harms need to be known. OBJECTIVES: To determine the efficacy and safety of strontium ranelate for the treatment and prevention of postmenopausal osteoporosis. SEARCH STRATEGY: We searched MEDLINE (1996 to March 2005), EMBASE (1996 to week 9 2005), the Cochrane Library (1996 to Issue 1 2005), reference lists of relevant articles and conference proceedings from the last two years. Additional data was sought from authors. SELECTION CRITERIA: We included randomized controlled trials (RCTs) of at least one year duration comparing strontium ranelate versus placebo reporting fracture incidence, bone mineral density (BMD), health related quality of life or safety in postmenopausal women. Treatment (versus prevention) population was defined as women with prevalent vertebral fractures and/or lumbar spine BMD T score < -2.5 SD. DATA COLLECTION AND ANALYSIS: Two reviewers independently determined study eligibility, assessed trial quality and extracted the relevant data. Disagreements were resolved by consensus. RCTs were grouped by dose of strontium ranelate and treatment duration. Where possible, meta-analysis was conducted using the random effects model. MAIN RESULTS: Four trials met the inclusion criteria. Three included a treatment population (0.5 to 2 g of strontium ranelate daily) and one a prevention population (0.125 g, 0.5 g and 1 g daily). A 37% reduction in vertebral fractures (RR 0.63, 95% CI 0.56, 0.71) and a 14% reduction in non-vertebral fractures (RR 0.86, 95% CI 0.75, 0.98) were demonstrated over three years with 2 g of strontium ranelate daily in a treatment population. An increase in BMD was shown at all BMD sites after two to three years in both populations. Lower doses of strontium ranelate were superior to placebo and the highest dose demonstrated the greatest reduction in vertebral fractures and increase in BMD. An increased risk of diarrhea with 2 g of strontium ranelate was found; however, adverse events did not affect the risk of discontinuing treatment nor did it increase the risk of serious side effects, gastritis or death. Additional data suggests that the risk of vascular and nervous system side-effects is slightly increased with taking 2 g of strontium ranelate daily over three to four years. AUTHORS' CONCLUSIONS: There is silver level evidence (www.cochranemsk.org) to support the efficacy of strontium ranelate for the reduction of fractures (vertebral and to a lesser extent non-vertebral) in postmenopausal osteoporotic women and an increase in BMD in postmenopausal women with/without osteoporosis. Diarrhea may occur however, adverse events leading to study withdrawal were not significantly increased with taking 2 g of strontium ranelate daily. Potential vascular and neurological side-effects need to be further explored.

Bone Density↗
PubMed2006

Strontium ranelate for preventing and treating postmenopausal osteoporosis.

BACKGROUND: Strontium ranelate is a new anti-osteoporosis therapy therefore, its benefits and harms need to be known. OBJECTIVES: To determine the efficacy and safety of strontium ranelate for the treatment and prevention of postmenopausal osteoporosis. SEARCH STRATEGY: We searched MEDLINE (1996 to March 2005), EMBASE (1996 to week 9 2005), the Cochrane Library (1996 to Issue 1 2005), reference lists of relevant articles and conference proceedings from the last two years. Additional data was sought from authors and industry sponsors. SELECTION CRITERIA: We included randomized controlled trials (RCTs) of at least one year duration comparing strontium ranelate versus placebo reporting fracture incidence, bone mineral density (BMD), health related quality of life and/or safety outcomes in postmenopausal women. Treatment (versus prevention) population was defined as women with prevalent vertebral fractures and/or lumbar spine BMD T score < -2.5 SD. DATA COLLECTION AND ANALYSIS: Two reviewers independently determined study eligibility, assessed trial quality and extracted the relevant data. Disagreements were resolved by consensus. RCTs were grouped by dose of strontium ranelate and treatment duration. Where possible, meta-analysis was conducted using the random effects model. MAIN RESULTS: A total of four trials met our inclusion criteria, three of which investigated the effects of strontium ranelate compared to placebo in a treatment population (doses ranged from 0.5 to 2 g daily) and one, in a prevention population (doses 0.125, 0.5 and 1 g daily). In osteoporotic, postmenopausal women a 37% reduction in vertebral fractures (two trials, n = 5082, RR 0.63, 95% CI 0.56 to 0.71) and a 14% reduction in non-vertebral fractures (two trials, n = 6572, RR 0.86, 95% CI 0.75 to 0.98) was demonstrated over a three year period with 2 g of strontium ranelate daily. An increase in BMD at all sites was shown with the same dose: lumbar spine BMD (two trials, n = 1614, WMD adjusted for strontium content 5.44, 95% CI 3.41 to 7.46 and WMD not adjusted 11.29, 95% CI 10.22 to 12.37 over two years), femoral neck and total hip (two trials, n = 4230, WMD 8.25, 95% CI 7.84 to 8.66 and WMD 9.83, 95% CI 9.39 to 10.26 respectively over three years). One gram of strontium ranelate daily in postmenopausal women without osteoporosis increased BMD at all sites over a two year period: lumbar spine (one trial, n = 59, WMD adjusted for strontium content 2.39, 95% CI 0.15 to 4.63 and WMD not adjusted 6.68, 95% CI 5.16 to 8.20), femoral neck (one trial, n= 60, WMD 2.52, 95%CI 0.96 to 4.09) and total hip (one trial, n = 60, WMD 1.02, 95% CI 0.48 to 1.56). In both the treatment and prevention populations, lower doses of strontium ranelate were superior to placebo with the highest dose of strontium ranelate demonstrating the greatest reduction in vertebral fractures and increase in BMD. There is some evidence to suggest that 2 g of strontium ranelate daily compared to placebo may have a beneficial effect on health related quality of life in postmenopausal women after three years of treatment. Two grams of strontium ranelate daily increased the risk of diarrhea (RR 1.38%, 95% CI 1.02 to 1.87); however, adverse events did not affect the risk of discontinuing strontium ranelate nor did it increase the risk of serious side effects, gastritis or death. Additional data obtained suggests that the risk of vascular system disorders including venous thromboembolism (two trials, n = 6669, 2.2% versus 1.5%, OR 1.5, 95% CI 1.1 to 2.1) and pulmonary embolism (two trials, n = 6669, 0.8% versus 0.4%, OR 1.7, 95% CI 1.0 to 3.1) as well as nervous system disorders such as headaches (3.9% versus 2.9%), seizures (0.3% versus 0.1%), memory loss (2.4% versus 1.9%) and disturbance in consciousness (2.5% versus 2.0%) is slightly increased with taking 2 g of strontium ranelate daily over a 3 to 4 year period. AUTHORS' CONCLUSIONS: There is silver level evidence to support the efficacy of strontium ranelate for the reduction of vertebral fractures (and to a lesser extent non-vertebral fractures) in postmenopausal osteoporotic women and an increase in BMD (all sites) in postmenopausal women with and without osteoporosis. Diarrhea may occur however, adverse events leading to study withdrawal were not significantly increased in the strontium ranelate group. Potential risks to the vascular and neurological system associated with taking 2 g of strontium ranelate daily need to be further explored and quantified.

Bone Density↗
PubMed2001

Social dominance, task performance and nutrition: implications for reproduction in eusocial wasps.

Dominance status is associated with individual differences in reproductive capacity in many animal societies, but the mechanisms that link social dominance to reproductive physiology are poorly understood. We propose a model for social dynamics that incorporates the nutritional costs and benefits of behavior: dominant individuals avoid energy-expensive behavior and build their nutritional reserves, thereby increasing their potential for reproduction. Greater reproductive capacity, once achieved, favors increased social dominance. To test the model, we measured relationships of females' nutrient storage and reproductive capacities with dominance status and task performance in the eusocial wasp Mischocyttarus mastigophorus. Ovary development was positively related with high levels of nutrient storage and with high rates of dominance behavior, but was not correlated with task performance. In contrast, high levels of nutrient storage were positively related with the performance of nutrient garnering and conserving tasks, but not with dominance behavior. These data support a model which places the nutritional costs of task performance as an intermediate causal link that connects dominance status with the accumulation of nutrient stores. Nutrient flow may be a general causal mechanism linking dominance status to reproductive capacity in animal societies.

Animal Nutritional Physiological Phenomena↗
PubMed2000

Three energy variables predict ant abundance at a geographical scale.

Energy theory posits three processes that link local abundance of ectotherms to geographical gradients in temperature. A survey of 49 New World habitats found a two order of magnitude span in the abundance (nests m(-2)) of ground nesting ants (Formicidae). Abundance increased with net primary productivity (r2=0.55), a measure of the baseline supply of harvestable energy. Abundance further increased with mean temperature (r2=0.056), a constraint on foraging activity for this thermophilic taxon. Finally for a given mean temperature, ants were more abundant in seasonal sites with longer, colder winters (r2 = 0.082) that help ectotherm taxa sequester harvested energy in non-productive months. All three variables are currently changing on a global scale. All should be useful in predicting biotic responses to climate change.

Animals↗
PubMed2000

Malignant carotid body tumor: a case report.

Carotid body tumors (CBTs) have an unpredictable history with no correlation between histology and clinical behavior. Of reported cases since 1891, local and distant metastases appear in approximately 10% of cases and remain the hallmark of malignancy. Currently, there are not enough data to support a single treatment regimen for malignant CBTs. The reported case demonstrates some unanswered issues with regard to malignant CBTs to include lymph node dissection, the need for carotid resection, and the role of radiation therapy. A 46-year-old pathologist underwent a resection of a Shamblin I CBT, to include jugular lymph node sampling, without complication. There was lymph node involvement, and tumor cells were found on the margins of the pathologic specimen. Subsequent carotid resection with reversed interposition saphenous vein graft and modified neck dissection were performed again without complication. Follow-up at 4 years has been uneventful. Diagnosis of CBTs with the use of magnetic resonance angiography, magnetic resonance imaging, color flow duplex scanning, and the role of arteriography are reviewed. The current treatment options are discussed with reference to primary lymph node sampling, carotid resection, and neck dissection in malignant cases. This case demonstrates that the unpredictable nature of CBTs and their malignant potential warrant aggressive initial local treatment to include jugular lymph node sampling and complete tumor resection.

Carotid Body Tumor↗
PubMed2000

Energy, Density, and Constraints to Species Richness: Ant Assemblages along a Productivity Gradient.

Species richness describes the number of species of a given taxon in a given time and space. The energy limitation hypothesis links the species richness of consumer taxa to net primary productivity (NPP) through two relationships: NPP limits a taxon's density, and taxon density limits species richness. We study both relationships with a survey of 15 ground ant assemblages, along a productivity gradient from deserts to rain forests. Ant density (colonies m-2) was a positive, decelerating function of net aboveground productivity (NAP). A stepwise regression suggests that the efficiency with which NAP is converted to ant colonies increases with maximum summer temperature and decreases with precipitation. Ant species richness was a positive decelerating function of density at three spatial scales. This supports the energy limitation hypothesis' assumption that average population densities are higher in environments that are more productive. These two nonlinear functions (NAP-density and density-species richness) combine to create, at a variety of scales, positive, decelerating, productivity-diversity curves for a common, ecologically dominant taxon across the terrestrial productivity gradient. However, variance in the density and diversity explained by NAP decreases with scale, suggesting that energy limitation of diversity predominates at small spatial scales (<1 ha).

Journal Article↗
PubMed2000

Telephone therapy for patients with breast cancer.

PURPOSE/OBJECTIVES: To test the value of telephone-administered cognitive-behavioral therapy in a study of patients with breast cancer. DESIGN: Women were assigned randomly to a therapy group or an assessment-only control group. SETTING: A tertiary cancer treatment center serving rural areas of North Dakota and Minnesota. SAMPLE: Women were recruited within three to four months of stage I (n = 27) or stage II (n = 26) breast cancer diagnosis. Age ranged from 30-82 (mean = 51.5 years). Most participants (n = 35) underwent a modified radical mastectomy; 17 underwent a lumpectomy. METHODS: Therapy involved 10 30-minute (or less) telephone sessions. Data that were collected from mailed questionnaires included psychological distress (Profile of Mood States), perceived stress, coping (Coping Response Indices-Revised), quality of life (Medical Outcome Scale), and satisfaction with therapy. Measures were completed at baseline and at 4- and 10-month follow-up intervals. MAIN RESEARCH VARIABLES: Telephone therapy, stress, coping, and quality of life. FINDINGS: With time, women in the therapy and control groups reported reduced stress and improved quality of life. However, significant reductions in some kinds of distress (anxiety, anger, depression, and confusion) were not observed. Most therapy participants liked the telephone treatment sessions but showed only modest improvement (less anxiety and confusion) compared with women in the control group. CONCLUSIONS: Most patients reported being comfortable with the telephone therapy and said that they felt better as a result of it. However, the outcome data showed that telephone therapy--as carried out in this study--produced only modest benefits. Researchers need to consider who is best for delivering such therapy. IMPLICATIONS FOR NURSING PRACTICE: Providing telephone therapy to patients with breast cancer has potential benefits, and nurses may be the appropriate professionals to administer the therapy.

Adaptation, Psychological↗
PubMed1999

Isolation and characterization of human monoclonal antibodies to digoxin.

Fab preparations of sheep polyclonal anti-digoxin Abs have proven useful for reversal of the toxic effects of digoxin overdoses in patients. Unfortunately, the use of foreign species proteins in humans is limited because of the potential for immunological responses that include hypersensitivity reactions and acute anaphylaxis. Immunization of recently developed transgenic mice, whose endogenous micro heavy and kappa light chain Ig genes are inactivated and which carry human Ig gene segments, with a digoxin-protein conjugate has enabled us to generate and isolate eight hybridoma cell lines secreting human sequence anti-digoxin mAbs. Six of the mAbs have been partially characterized and shown to have high specificity and low nanomolar affinities for digoxin. In addition, detailed competition binding studies performed with three of these mAbs have shown them to have distinct differences in their digoxin binding, and that all three structural moieties of the drug, the primary digitoxose sugar, steroid, and five-member unsaturated lactone ring, contribute to Ab recognition.

Animals↗
PubMed1999

Consequences of premature discontinuation of the developmental test of visual-motor integration: can these tests be salvaged?

The administration of many neuropsychological tests includes discontinuation criteria that are often complex and time-consuming. As a result, it is not uncommon for an examiner to unintentionally discontinue the administration of a test prematurely. This investigation of 56 correctly scored Developmental Test of Visual-Motor Integration protocols was conducted to determine how the premature termination of this particular test significantly affects its overall score, and thus, its interpretation. These data indicate that premature discontinuation of this test results in a minimal loss of points overall, and thus, does not invalidate the interpretation of its score.

Alzheimer Disease↗
PubMed1999

Competence of depressed patients for consent to research.

OBJECTIVE: The capacities of depressed patients to consent to research have been questioned by commentators who fear that the cognitive effects of a disorder may impair subjects' abilities to protect their interests. This study used a new instrument for assessing depressed patients' capacities to consent to research and examined their performance, including the relation between severity of depression and extent of impairment. METHOD: Twenty-six female outpatients with major depression (assessed with the Schedule of Affective Disorders and Schizophrenia-Lifetime Version) enrolled in a study of maintenance psychotherapy were recruited for this project. Consent-related abilities were measured with the MacArthur Competence Assessment Tool-Clinical Research (MacCAT-CR) 1 week after intake and again 8-10 weeks later. Depressive symptoms were measured by the Hamilton Depression Rating Scale. RESULTS: Almost all subjects performed quite well on the capacity measures and maintained that level of performance over time. There was no correlation between performance and degree of depressive symptoms and little relation to prior research experience. Some subjects appeared confused about the extent to which decisions about assignment to treatment groups would be made on the basis of their clinical condition rather than randomly. CONCLUSIONS: This outpatient group with major depression showed few impairments in their decision-making capacities related to research. As in other studies, some concerns were raised about subjects' appreciation that treatment assignments would not be individualized for their needs. Examination of hospitalized patients and those with psychotic depression would help to determine whether they show greater degrees of impairment. The MacCAT-CR was easily adapted for use with this depressed group.

Adult↗
PubMed1998

Perioral forces and dental changes resulting from mandibular lip bumper treatment.

This prospective study compares pretreatment and posttreatment forces produced by a lip bumper on the mandibular first molars and determines the dental effects of this appliance after 1 year of treatment. Twenty-five patients, ages 10 to 17 years, received fixed 0.045-inch passive stainless steel lip bumpers positioned at the level of the gingival margin, 2 mm from the labial surface of the teeth as the only form of treatment in the mandibular arch. At the end of 1 year, cephalometric radiographs and dental casts were taken, and lower lip forces remeasured during rest, speech, and swallowing. Lip force measurements were performed using specially designed strain gauges mounted bilaterally in the lip bumper tubes. Measurements of lip forces made before and after treatment were compared to explore the changes, if any, due to muscle adaptation to the appliance. Dental changes were measured from casts and cephalometric radiographs. Correlation analyses were performed to determine whether a relationship existed between initial force levels and resulting tooth movement. Pretreatment and posttreatment forces did not demonstrate a statistically significant difference. On the other hand, measurement of the dental casts revealed a significant increase in arch length caused by incisor proclination and protrusion, combined with molar distalization. The arch width significantly increased at the canines, first and second premolars, and first molars. The amount of force exerted by the lower lip on the molars was not correlated to the degree of tooth movement recorded in this sample.

Adaptation, Physiological↗
PubMed1998

Reproductive caste determination in eusocial wasps (Hymenoptera: Vespidae).

Wasps (Vespidae) exhibit a range of social complexity, from solitary living to eusocial colonies, and thus are exemplary for studies of the evolutionary origin and maintenance of social behavior in animals. Integral to the definition of eusociality is the presence of reproductive castes, group members that differ qualitatively in their ability to reproduce in a social setting. Behavioral and morphological evidence suggests that caste determination, the developmental process by which differences in fecundity are established, occurs to a large extent before adult emergence (pre-imaginally) in many species of Vespidae, in both basal and advanced taxa within the clade (Vespinae+Polistinae), which includes most eusocial species. Pre-imaginal determination has been documented in many taxa (e.g. independent-founding Polistinae) where it was not thought to occur. Correlative and experimental studies indicate that differences in nutrition during larval development are often the basis of pre-imaginal caste determination. Pre-imaginal caste determination has important implications for the roles of subfertility and manipulation by nest mates in the evolution of eusocial behavior.

Journal Article↗
PubMed1998

Analysis of 1263 deaths in four general practices.

BACKGROUND: The death of a patient is a significant event that occurs often enough in general practice for it to have the potential to tell us much about the care we provide. There are few large series in the literature and we still know little about the collaborative use of this outcome measure. AIM: To determine the pattern of deaths and potentially preventable factors in our practices. METHOD: We completed a standard data collection form after each death in four general practices over a 40-month period. The results were discussed at quarterly meetings. RESULTS: A total of 1263 deaths occurred among our registered patients during the period of the audit. Preventable factors contributing to deaths were considered to be attributable to: patients (40%): mainly cigarette smoking, poor compliance, and alcohol problems; general practice teams (5%): mainly delayed referral, diagnosis and treatment, and failure to prescribe aspirin to patients with vascular disease; hospitals (6%): mainly delayed diagnosis and perceived treatment problems; the environment (3%): mainly falls, principally resulting in fractured neck of femur. CONCLUSION: A simple audit of deaths along the lines that we describe gives important information about the care provided by general practice teams and those in hospital practice. It has both educational value and is a source of ideas for service improvement and further study, particularly when carried out over several years.

Accidental Falls↗