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Biomedical subjects

B Campbell

Publications and source records attributed to B Campbell.

At least 55 records · Page 3Linked to original sources
PubMed1999

Influenza vaccination in long-term-care facilities: structuring programs for success.

OBJECTIVES: To determine which influenza vaccination program characteristics were associated with high resident vaccination rates in Canadian long-term-care facilities (LTCFs). DESIGN: A cross-sectional survey consisting of a mailed questionnaire conducted in spring 1991. PARTICIPANTS: All 1,520 Canadian LTCFs for the elderly with at least 25 beds. RESULTS: The mean overall influenza vaccination rate in the 1,270 (84%) responding facilities was 79%. In multivariate analysis, the variables significantly associated with increased vaccination rates were: a single nonphysician staff person organizing the program, having more program aspects covered by written policies, the offering of vaccine to all residents, a policy of obtaining consent on admission that was durable for future years rather than repeating consent annually, and automatically administering vaccine to residents whose guardians could not be contacted for consent. Any encouragement to staff to be vaccinated had a significant impact on staff vaccination rates. CONCLUSION: Well-organized influenza vaccination programs increase the influenza vaccination rates of residents in Canadian LTCFs. Facilities need to develop resident vaccination programs further and to focus on vaccinating staff.

Aged↗
PubMed1999

Cardioprotective effects of abciximab (ReoPro) in an isolated perfused rat heart model of ischemia and reperfusion.

Ischemia followed by reperfusion in the presence of polymorphonuclear leukocytes (PMNs) results in cardiac contractile dysfunction as well as myocardial injury, due in large part to endothelial dysfunction, upregulation of cell adhesion molecules and subsequent neutrophil induced cardiac injury. We studied the effects of abciximab (ReoPro), an anti-IIb/IIIa antibody, which has been shown to attenuate platelet interactions, in a neutrophil-platelet mediated isolated perfused rat heart model of ischemia (I) (20 min) and reperfusion (R) (45 min). Administration of abciximab (6.5 micrograms/kg) 10 min prior to the perfusion of the PMN + platelet perfused I/R heart improved post-reperfusion coronary flow and preserved post-reperfusion left ventricular developed pressure (LVDP) and +dP/dt max as indices of cardiac contractile function. Abciximab-treated hearts reperfused in the presence of PMNs and platelets preserved all indices of cardiac contractile function. I/R heart perfused with PMNs and platelets produced a profound injury to the hearts which was attenuated with the treatment of abciximab. In addition, abciximab significantly reduced PMN accumulation in the ischemic myocardium from 38 +/- 1 PMNs/mm2 in untreated hearts to 7 +/- 1 in rats given abciximab. Similar results were obtained with PMN perfused I/R rat hearts without platelets. These results provide evidence that abciximab is a potent and effective cardioprotective agent that inhibits leukocyte-endothelial cell interactions as well as platelet-endothelial cell interaction and preserves cardiac contractile function and coronary perfusion following myocardial ischemia and reperfusion. Therefore, IIb/IIIa may be important in attenuating both platelet and neutrophil-mediated myocardial dysfunction.

Abciximab↗
PubMed1999

Appealing to the donors too much?

Many fund raisers believe that almost all donors feel they are receiving too many appeals. However, that is not always the case. Donors' perceptions of appeals vary widely from one organization to the next, and are also influenced by outside factors, such as age and overall non-profit mail received.

Adult↗
PubMed1999

Who are my donors?

When designing a communications/marketing plan, it is critical to base it on a clear, accurate understanding of the target audience. Specifically, non-profits should have a great understanding of who their constituents are.

Data Collection↗
PubMed1998

Synergism between platelets and neutrophils in provoking cardiac dysfunction after ischemia and reperfusion: role of selectins.

BACKGROUND: Neutrophils (PMNs) are known to contribute to both cardiac dysfunction and myocardial necrosis after reperfusion of an ischemic heart. Moreover, platelets are also important blood cells that can aggravate myocardial ischemic injury. This study was designed to test the effects of PMNs and platelets separately and together in provoking cardiac dysfunction in isolated perfused rat hearts after ischemia and reperfusion. METHODS AND RESULTS: Control rat hearts not subjected to ischemia were perfused without blood cells for 80 minutes. Additional control rat hearts were perfused with 75x106 PMNs, with 100x106 platelets, or with 75x106 PMNs+100x106 platelets over a 5-minute perfusion followed by a 75-minute observation period. No significant reduction in coronary flow, left ventricular developed pressure (LVDP), or the first derivative of LVDP (dP/dtmax) was observed at the end of the observation period in any nonischemic group. Similarly, global ischemia (I) for 20 minutes followed by 45 minutes of reperfusion (R) produced no sustained effects on the final recovery of any of these parameters in any group of hearts perfused in the absence of blood cells. However, I/R hearts perfused with either PMNs or platelets alone exhibited decreases in these variables of 10% to 12% (P<0.05 from control). Furthermore, I/R hearts perfused with both PMNs and platelets exhibited decreases of 50% to 60% in all measurements of cardiac function (P<0.001). These dual-cell-perfused I/R hearts also exhibited marked increases in cardiac myeloperoxidase (MPO) activity, indicating a significant PMN infiltration, and enhanced P-selectin expression on the coronary microvascular endothelium. All cardiodynamic effects as well as MPO accumulation and PMN infiltration were markedly attenuated by a sialyl LewisX-oligosaccharide or a recombinant soluble P-selectin ligand, which inhibits selectin-mediated cell adhesion. CONCLUSIONS: These results provide evidence that platelets and neutrophils act synergistically in provoking postreperfusion cardiac dysfunction and that this may be largely due to cell-to-cell interactions mediated by P-selectin. These findings may help explain the reperfusion injury phenomenon.

Animals↗
PubMed1998

Inverse relationship between electrode size and lesion size during radiofrequency ablation with active electrode cooling.

BACKGROUND: Clinical efficacy has driven the use of larger electrodes (7F, length > or =4 mm) for radiofrequency ablation, which reduces electrogram resolution and causes variability in tissue contact depending on electrode orientation. With active cooling, ablation electrode size may be reduced. The purpose of this study was to examine the effect of electrode length on tissue temperature and lesion size with saline irrigation used for active cooling. METHODS AND RESULTS: In 11 anesthetized dogs, the thigh muscle was exposed and bathed with heparinized canine blood. A 7F ablation catheter with a 2- or 5-mm irrigated tip electrode was positioned perpendicular or parallel to the thigh muscle. Radiofrequency current was delivered at constant voltage (50 V) for 30 seconds during saline irrigation (20 mL/min) to 148 sites. Tissue temperature at depths of 3.5 and 7 mm and lesion size were measured. In the perpendicular electrode-tissue orientation, radiofrequency applications at 50 V with the 2-mm electrode compared with the 5-mm electrode resulted in lower power at 50 V (26 versus 36 W) but higher tissue temperatures, larger lesion depth (8.0 versus 5.4 mm), and greater diameter (12.4 mm versus 8.4 mm). Also, in the parallel orientation, overall power was lower with the 2-mm electrode (25 versus 33 W), but tissue temperatures were higher and lesions were deeper (7.3 versus 6.9 mm). Lesion diameter was similar (11.1 versus 11.3 mm) for both electrodes. CONCLUSIONS: The smaller electrode resulted in transmission of a greater fraction of the radiofrequency power to the tissue and resulted in higher tissue temperature, larger lesions, and lower dependency of lesion size on the electrode orientation.

Animals↗
PubMed1998

Effects of a metalloproteinase that truncates P-selectin glycoprotein ligand on neutrophil-induced cardiac dysfunction in ischemia/reperfusion.

This study was designed to test the effects of polymorphonuclear leukocytes (PMNs) in the presence and absence of a P-selectin blocker, mocarhagin, in provoking cardiac dysfunction in isolated perfused rat hearts following ischemia and reperfusion. Control rat hearts not subjected to ischemia were perfused without blood cells for 80 min. Additional control rat hearts were perfused with 100 x 10(6) PMNs in the presence and absence of 0.2 microgram/ml mocarhagin over a 5-min perfusion followed by a 45-min observation period. No significant reduction in coronary flow (CF), left ventricular developed pressure (LVDP), or the first derivative of LVDP (dP/dt max) was observed at the end of the observation period in any non-ischemic group. Similarly, global ischemia (I) for 20 min followed by 45 min of reperfusion (R) produced no sustained effects on the final recovery of any of these parameters in any group of hearts perfused in the absence of PMNs. I/R hearts perfused with PMNs exhibited decreases of 50-60% in all measurements of cardiac function (P < 0.001). These PMN perfused I/R hearts also exhibited marked increases in cardiac myeloperoxidase (MPO) activity indicating a significant PMN infiltration, and enhanced P-selection expression on the coronary microvascular endothelium. All cardiodynamic effects as well as MPO accumulation and PMN infiltration were attenuated markedly by the metalloproteinase, mocarhagin, which inhibits P-selectin-mediated cell adhesion by cleaving its high-affinity receptor, PSGL-1, present on neutrophils. These results provide evidence that neutrophils provoke post-reperfusion cardiac dysfunction, and that this may be largely due to P-selectin-induced adherence of neutrophils to the endothelium.

Animals↗
PubMed1998

Beneficial effects of N,N,N-trimethylsphingosine following ischemia and reperfusion in the isolated perfused rat heart.

OBJECTIVE: Ischemia followed by reperfusion in the presence of polymorphonuclear leukocytes (PMNs) results in cardiac contractile dysfunction as well as myocardial injury. These deleterious effects are due in large part to endothelial dysfunction leading to an upregulation of cell adhesion molecules and subsequent neutrophil-induced cardiac injury. At physiologically relevant concentrations, N,N,N-trimethylsphingosine (TMS), a synthetic N-methylated sphingosine derivative, has been shown to attenuate leukocyte-endothelial cell interactions. We wanted to test the effects of TMS on neutrophil-mediated cardiac dysfunction in ischemia/reperfusion. METHODS: This study examines the effects of TMS in a neutrophil-dependent isolated perfused rat heart model of ischemia (I) (20 min) and reperfusion (R) (45 min) injury. RESULTS: Administration of TMS (20 micrograms/kg) to I/R hearts perfused with PMNs improved coronary flow and preserved left ventricular developed pressure as an index of cardiac contractile function (95 +/- 5%) in comparison to those I/R hearts receiving only vehicle (60 +/- 7%) (P < 0.001). In addition, TMS significantly reduced PMN accumulation in the ischemic myocardium, as evidenced by an attenuation in cardiac myeloperoxidase activity from 1.12 +/- 0.04 in untreated hearts to 0.01 +/- 0.02 in treated hearts (P < 0.001). However, TMS did not directly stimulate nitric oxide (NO) release from rat vascular endothelium. CONCLUSION: These results provide evidence that TMS is a potent and effective cardioprotective agent that inhibits leukocyte-endothelial cell interactions and preserves cardiac contractile function and coronary perfusion following myocardial ischemia and reperfusion.

Animals↗
PubMed1998

Pre-emptive kidney transplantation: the attractive alternative.

BACKGROUND: Dialysis can be life-saving for patients with end-stage renal failure. However, not only is it associated with significant morbidity and a greater mortality than transplantation, but it is also expensive. Therefore renal transplantation is generally regarded as the treatment of choice for patients in whom this form of renal replacement therapy is appropriate. Transplantation usually takes place after a variable period of dialytic therapy, but pre-emptive kidney transplantation (PKT) has established itself as an attractive alternative. MATERIALS AND METHODS: 1463 consecutive first kidney transplants performed between January 1980 and December 1995 in a single centre were analysed. The 161 patients (11%) transplanted without prior dialysis were compared with the 1302 patients who had been dialysed prior to being transplanted. The pre-emptive group did not differ from the dialysis group in respect of donor age, donor and recipient gender, HLA mismatch, or cold ischaemic time, although there were more live donor transplants within the pre-emptive group. RESULTS: Delayed graft function occurred more frequently in the dialysis group (25% vs 16%) but more patients experienced an acute rejection episode in the pre-emptive group (67 vs 55%). The actuarial graft survival in the pre-emptive group at 1, 5, and 10 years (84, 76 and 67%) was significantly higher than the respective values in the dialysis group (83, 69, and 56%). Within the live donor recipient cohort the survival advantage for the pre-emptive group was even more striking. CONCLUSION: Pre-emptive kidney transplantation not only avoids the risks, cost, and inconvenience of dialysis, but is also associated with better graft survival than transplantation after a period of dialysis, particularly within the live donor cohort.

Adult↗
PubMed1998

Risperidone for the treatment of behavioral disturbances in dementia: a case series.

The authors describe a series of 22 patients with dementia and behavioral disturbances, including agitation, aggression, delusions, and hallucinations, who were treated with risperidone. Risperidone, in low doses, was well tolerated; 50% of patients experienced significant improvement, although 50% experienced some extrapyramidal symptoms.

Aged↗
PubMed1998

Clinical pattern of perforated prepyloric and duodenal ulcer at Ile-Ife, Nigeria.

High morbidity and mortality often attend perforation of duodenal ulcer. Over a 6-year period at Obafemi Awolowo University Teaching Hospital, Ile-Ife, Nigeria, 22 patients presented with prepyloric or duodenal ulcer perforations--a relatively low yearly rate of about four. Of the 15 patients evaluated, approximately three-quarters were working class young men and eight (53%) had no ulcer history. The high morbidity, and 20% mortality rate, observed were attributable to late presentation and the presence of advanced bacterial peritonitis in 67% of the patients at admission. Imprecise clinical features in those with small perforations led to misdiagnosis in a third of cases. Treatment of perforations in the majority (93%) of patients was by simple closure or truncal vagotomy and pyloroplasty. An increase in patients' awareness of the potentials of optimal operative management should encourage earlier presentation.

Adolescent↗
PubMed1998

Clinical case discussion: the elderly patient with psychosis.

OBJECTIVE: To present a clinical case of an elderly person with psychosis and to discuss associated diagnostic and treatment issues. METHODS: A case from 1 of the authors' clinical practices was presented in English and French to several groups of Canadian psychiatrists attending a teaching day on psychosis. Three geriatric psychiatrists acted as facilitators, soliciting the clinical experiences of the participants in the discussion. The authors integrated clinical content from these sessions with results of a Medline search on psychosis in elderly persons. RESULTS: The assessment of elderly patients with psychosis is more often than in younger patients by overlying organicity, including delirium due to illness or medication use, dementia, or sensory deficits. Treatment might further worsen cognitive, affective, and functional impairment through adverse effects such as extrapyramidal symptoms (leading to decreased mobility and general functioning), anticholinergic effects (predisposing to delirium), and hypotension (predisposing to falls). Newer antipsychotics with less hazardous side effect profiles have an increasing role, but they must be coupled with psychosocial support to maximize the patient's independent functioning and quality of life after discharge. CONCLUSIONS: Assessment and treatment of the elderly person with psychosis must consider a wide variety of biopsychosocial variables, seeking to minimize further treatment-related deterioration. Controlled studies of antipsychotics in elderly people must be conducted in a variety of diagnostic situations that reflect their actual use in the community, and information must be propagated effectively among general psychiatrists, family physicians, and geriatric psychiatrists. The role of nonpharmacologic interventions in elderly persons with psychosis is even less well understood and deservers further study.

Aged↗