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Biomedical subjects

G Brennan

Publications and source records attributed to G Brennan.

At least 19 recordsLinked to original sources
PubMed2006

Stage-specific differences in fecundity over the life-cycle of two characterized isolates of the liver fluke, Fasciola hepatica.

The variability inherent in different isolates of Fasciola hepatica has been evident from reports in the literature but to date there has been no systematic examination of the relationship between these differences and the fecundity of the parasite. In this study we have attempted to remedy this situation by comparing the relative efficiencies with which 2 well-characterized isolates of the liver fluke (Oberon and Fairhurst) progress through both their definitive and intermediate hosts. We did not observe a reduction in fitness in the Oberon isolate which has been reported to be triclabendazole-resistant, compared to the triclabendazole-susceptible Fairhurst isolate, but considerable inter- and intra-isolate variability at different life-cycle stages was recorded. Thus the Oberon isolate gave 4-fold the number of cercariae when 100 snails were each challenged with a single miracidium and was more successful in establishing productive infections in rats. Fairhurst metacercariae excysted at a higher rate than those from the Oberon isolate and Fairhurst flukes produced 4-fold more eggs. The extent of the intra- and inter-isolate variability revealed in this work will provide a basis for the development of models of population dynamics aimed at predicting the response of the liver fluke to changing environmental conditions such as the use of anthelmintics or climatic change.

Adaptation, Physiological↗
PubMed2006

Preliminary outcomes of a trial to reduce conflict and containment on acute psychiatric wards: City Nurses.

Acute psychiatric wards experience high levels of conflict behaviours (violence, absconding, self-harm, rule breaking and medication refusal) by patients. These events cause stress and injury to staff and patients. Their management through containment methods (e.g. sedation, restraint, seclusion) is contentious, and nurses are ambivalent about their use. The aim of this study was to reduce conflict and containment on two acute psychiatric wards through changes in nurses' beliefs, attitudes and practices. Two 'City Nurses' were employed to work with two acute wards for 1 year, assisting with the implementation of changes according to a working model of conflict and containment generation, itself based on previous research. Evaluation was via before-and-after measures. Statistically and clinically significant decreases in conflict occurred, with falls in aggression, absconding and self-harm. Ward atmosphere improved and nurse-patient interaction rates increased. There was no significant change in containment method use. Significant reductions in aggression, absconding and self-harm can be achieved on acute psychiatric wards. However, it does not appear that containment can be reduced, even through large reductions in conflict.

Attitude of Health Personnel↗
PubMed2006

Reflections on the process of change on acute psychiatric wards during the City Nurse Project.

The intention of this paper is to discuss the process of therapeutic change on two acute psychiatric wards during a research project that aimed to reduce conflict and containment. Analysis of fieldwork notes, reflection, team discussion and supervision. The City Nurse Project successfully reduced patient aggression, self-harm and absconding. This paper reports on the reflections made over the course of the year as changes and developments to acute wards took place. Specifically discussed are the beneficial effects of an action research approach, the role of the City Nurse, support for ward managers, education and training, clinical supervision as well as difficulties and barriers to the overall process of change. At an interim stage of the project, the staff have shown a willingness to engage in efforts to change and improve two acute wards. This paper shows the potential to improve acute wards and produce positive outcomes using a working model.

Behavior Control↗
PubMed2006

Constraints and blocks to change and improvement on acute psychiatric wards--lessons from the City Nurses project.

Recent years have seen sustained criticism and inspection of acute inpatient psychiatric wards, with the publication of reports and research leading to policy developments and a variety of efforts to improve perceived deficits. The City Nurses project seeks to reduce levels of conflict and containment on acute wards through the placement of expert nurses on wards to assist with the implementation of changes according to a working model of conflict and containment generation, based on previous research. Evaluation has shown significant decreases in aggression, absconding and self-harm by patients. However, in the course of working with the wards, various constraints and blocks to change have been identified and we describe these in detail in this paper. Analysis of the fieldwork diaries of the two City Nurses identified that change was hindered by limited staffing resources, problems with the physical environment and other resources, insufficient beds and the process of bed management, hierarchical ambiguity and multidisciplinary issues, the overdemanding role of the ward manager, and pervasive anxiety about the potential for serious untoward incidents and their implications for staff. We argue that sustained positive change in acute inpatient psychiatry requires these underlying structural issues to be both acknowledged and, if possible, resolved.

Acute Disease↗
PubMed2004

Treatment gap in the use of lipid-lowering drug therapy in diabetes: a population-based study.

BACKGROUND: Lowering cholesterol is highly effective in reducing morbidity and mortality in high-risk people with prevalent cardiovascular disease. AIMS: To investigate lipid-lowering therapy use for secondary prevention of coronary heart disease in all diabetic patients in Tayside, Scotland. METHODS: Among the 385,500 Tayside residents on 31 March 2001, the DARTS database identified all people with Types 1 and 2 diabetes with prevalent macrovascular disease, defined as a history of angina or coronary heart disease. The uptake of lipid-lowering drug was ascertained from MEMO's database of prescriptions dispensed at Tayside pharmacies. RESULTS: Among the 1128 Type 1 patients, 11.3% had prevalent macrovascular disease and 7.9% used lipid-lowering therapy with 42.2% for patients with macrovascular disease. Current/former smokers (OR 2.40, 95% CI: 1.15-5.03) and those with a history of coronary heart disease (OR 2.26, 95% CI: 1.04-4.90) were more likely to use lipid-lowering therapy. Among the 8686 Type 2 patients, 38.8% had prevalent macrovascular disease and 18.3% used lipid-lowering therapy, with 26.7% for patients with macrovascular disease. Current/former smokers (OR 1.37; 95% CI 1.17-1.61) and those with a history of coronary heart disease (OR 2.07, 95% CI 1.66-2.59) or angina (OR 1.30, CI 1.03-1.63) were more likely to use lipid-lowering therapy. A duration of 4 years or less from the first macrovascular event was associated with increased use (OR 1.27; 95% CI 1.05-1.54). Age > 70 years reduced the likelihood (OR 0.51, CI 0.44-0.60). CONCLUSION: A clear gap exists between those requiring lipid-lowering drug therapy and those who are actually receiving it in Tayside.

Adult↗
PubMed2001

Studies on the immunoglobulin E responses to Teladorsagia circumcincta in sheep: purification of a major high molecular weight allergen.

Studies on the immunoglobulin (Ig)E immune responses to the gastric nematode, Teladorsagia circumcincta, have demonstrated a major high molecular weight allergen (HMWTc). Cross reactive allergens of similar MW were demonstrated for Trichostrongylus colubriformis and Cooperia curticei, but not for Haemonchus contortus. Purification of HMWTc was achieved by gel-filtration chromatography, and nonreducing SDS-PAGE and Western blot analysis revealed two closely associated bands with a molecular weight of approximately 140-150 kDa. Reduction showed four IgE reactive bands of 120, 50, 45 and 30 kDa, and deglycosylation abrogated the immunoreactivity of the 120 and 30 kDa bands. Ultrastructural immunolocalization by electron microscopy revealed that the IgE reactivity was confined to the cuticular surface of the infective (L3) larvae. ELISA studies to determine the IgE anti-HMWTc responses in lambs during their first grazing season, demonstrated significantly higher IgE antibody in lambs with low accumulative faecal egg count (FEC) compared to animals with high accumulative FEC. These studies provide evidence for a protective function of IgE antibody in Teladorsagia infections in lambs.

Allergens↗
PubMed2001

PathworX: an informatics tool for quality improvement.

To optimize quality of care while conserving resources requires the right information and the right organizational processes. PathworX, a care management and documentation system developed at Vanderbilt, coordinates interdisciplinary care based on evidence-based best practices and provides information about the achievement of patient care goals as an indicator of quality. Using data about goal achievement and resource consumption in a process of continual quality improvement enables hospital units to reduce waste while improving patient outcomes.

Decision Support Systems, Clinical↗
PubMed2000

High prevalence of primary aldosteronism in the Tayside hypertension clinic population.

Primary aldosteronism (PA) was thought to be rare but recent evidence from Australia suggests that it may be more common. As this has important implications in terms of hypertension management, we undertook to screen for this treatable condition in our hypertension clinic. We obtained blood samples in sequential patients referred for assessment in our hypertension clinic in Tayside for plasma renin activity (PRA) and aldosterone. The aldosterone to PRA ratio (ARR) was used as an initial screening test to identify potential patients with PA. Those patients with an elevated ratio (> or =750) were admitted for the salt loading and fludrocortisone suppression test. These patients also underwent adrenal CT scanning, and in selected patients, adrenal scintigraphy. Between May 1995 and January 1997 (21 months), we screened a total of 495 patients. ARR was available in 465 (93.9%) patients. Out of that number, 77 (16. 6%) had an elevated ratio of > or =750, five of whom had an adrenal adenoma (one had previous adrenalectomy). Forty-five of these patients were admitted for the salt loading and fludrocortisone suppression test with 41 positive test results suggesting PA. One patient with a negative salt loading test result however had an adenoma proven on histology. A total of 43 cases of PA were identified, giving a minimum prevalence of 9.2% (43/465). Potentially the prevalence may be up to 15% assuming that the ARR has a sensitivity of 93% (42/45) in predicting PA. In conclusion, about one in 10 patients attending a hypertension clinic may have PA. This suggests that the prevalence of PA in Tayside is as high as that in the Australian hypertensive population, and this is likely to be true elsewhere, with obvious important implications for hypertension management.

Adult↗
PubMed1998

Clinical and biochemical determinants of plasma lipid peroxide levels in type 2 diabetes.

The enhanced risk and increased severity of atheroma in diabetes is well recognized but, as yet, incompletely explained. A cross-sectional study of vascular disease risk factors in a group of type 2 diabetic patients from South West Scotland has revealed an association between glycaemic control, assessed by HbAl level and plasma lipid peroxides measured by a specific high-performance liquid chromatography method. Duration of diabetes appeared to be a subsidiary contributor to lipid peroxidation. We suggest this evidence supports the importance of glycaemic control in modulating glyco-oxidative mechanisms probably crucial to production of diabetic complications. Atherosclerosis prevention in diabetes may hinge on exemplary simultaneous control of both hyperglycaemia and hyperlipidaemia.

Chromatography, High Pressure Liquid↗
PubMed1998

Providing information to carers of people admitted to psychiatric hospital.

Relatives have an increasingly important role in providing care in the community to people with mental health problems, yet numerous studies have highlighted a lack of support from health care professionals. GEOFF BRENNAN describes the findings of a study to investigate the information provided to relatives of patients in one trust, and suggests solutions to the ethical and professional dilemmas raised.

Adult↗
PubMed1998

Providing information to carers of people admitted to psychiatric hospital.

Relatives have an increasingly important role in providing care in the community to people with mental health problems, yet numerous studies have highlighted a lack of support from health care professionals. GERARD LEAVEY and colleagues describe a study to investigate the information provided to relatives of patients in one trust, and suggest solutions to the ethical and professional dilemmas raised.

Adult↗
PubMed1994

Meal patterns of macronutrient intake in rats with particular dietary preferences.

In the present study, we examined, via computer-assisted analyses, the nocturnal meal patterns of male albino Sprague-Dawley rats with clear differences in their individual preferences for the macronutrients, protein, carbohydrate, and fat. Rats exhibiting a strong preference for the carbohydrate diet over the 12-h nocturnal cycle (approximately 50% of the group) consumed fewer total calories and relatively small, more frequent meals, compared with rats that preferred protein or fat. Moreover, the first meal of the feeding cycle was identified as being most distinctive in reflecting the individual dietary preferences of these rats. This contrasts with the subsequent meals, which for all rats showed a general trend of increasing proportions of protein and fat and a decreasing concentration of carbohydrate. Only the high-fat rats (approximately 30% of the group) were further distinguished by a particularly large fat-predominant meal in the middle-dark period, which was then followed by smaller fat-rich meals in the late-dark period. These fat-preferring rats exhibited significantly greater body weight gain compared with rats preferring carbohydrate.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗
PubMed1993

Meal pattern analysis of macronutrient intake after PVN norepinephrine and peripheral clonidine administration.

Norepinephrine (NE) injected into the paraventricular nucleus (PVN) of the hypothalamus of rats is a potent stimulant of food intake, more specifically ingestion of the carbohydrate nutrient. In 2 experiments of the present study, this effect was found to be dose-dependent, and the effectiveness of NE in potentiating total food consumption was greatly reduced when the carbohydrate diet was removed. In addition, experiments using a computer-automated data acquisition apparatus were performed to characterize, in detail, the impact of PVN injection of NE and peripheral administration of the alpha2-noradrenergic agonist clonidine (CLON) on the macrostructure of feeding behavior in animals given 3 pure macronutrient diets. These 2 compounds, injected at the onset of the nocturnal feeding cycle, had very similar effects on meal patterns, with both affecting nutrient intake by increasing meal size and duration rather than by increasing meal frequency. They both affected primarily the first meal of the dark cycle, selectively enhancing carbohydrate ingestion by increasing Kcal intake, percent composition in the total diet and feeding time, and also by decreasing the satiating impact of this macronutrient. These stimulatory effects of NE and CLON on carbohydrate ingestion during the first meal were followed by complete recovery over the next 1 to 2 hours after injection. In addition to these predominant effects on carbohydrate intake, PVN NE at the highest doses tested (10 and 20 nmoles) produced a small increase in fat intake, whereas peripheral CLON actually decreased intake of fat and protein over the 12-hour cycle. The similarities in the impact of NE and CLON on carbohydrate feeding patterns support the hypothesis that both agonists may be acting via the same PVN alpha2-noradrenergic system controlling ingestion of the carbohydrate-rich meals which predominate at dark onset.

Adrenergic alpha-Agonists↗
PubMed1993

Vascular abnormalities in non-insulin-dependent diabetes mellitus identified by arterial waveform analysis.

PURPOSE: The arterial pressure waveform is derived from the complex interaction of the left ventricular stroke volume and the physical properties of the arterial circulation. Widespread abnormalities in the physical characteristics of the arterial vessels associated with diabetes mellitus can produce consistent changes in the shape of the pressure pulse waveform, providing information about arterial structure and tone that can be quantitated by pulse contour analysis. PATIENTS AND METHODS: We analyzed intraarterial brachial artery waveforms in 28 patients with non-insulin-dependent diabetes mellitus and 22 control subjects matched for age and sex. A computer-based assessment of the diastolic pressure decay and a modified Windkessel model of the circulation were employed to quantify changes in arterial waveform morphology in terms of the large-artery compliance (C1), the oscillatory diastolic waveform (C2), inertance, and systemic resistance. RESULTS: No differences were found in heart rate, mean arterial pressure, cardiac output, or stroke volume between groups. The mean oscillary arterial compliance estimate was significantly reduced in diabetic subjects versus controls: 0.02 (95% confidence interval [CI], 0.01 to 0.03) mL/mm Hg versus 0.08 (95% CI, 0.04 to 0.12) mL/mm Hg (p < 0.001). Oscillatory compliance values were uniformly reduced in the diabetic subjects regardless of the presence or absence of physical complications of the disease. No differences in large-artery compliance, inertance, or systemic resistance were found between groups. No positive correlations were found between indices of glycemic control, the known duration of diabetes, and any of the hemodynamic variables. CONCLUSIONS: Quantitative changes in the arterial pressure pulse waveform, reflected by a reduced oscillatory compliance estimate, were found in patients with non-insulin-dependent diabetes mellitus. This estimate appears to act as an early marker for the vascular abnormalities associated with diabetes before complications of the disease become clinically apparent. By contrast, no changes in large-artery compliance were found in this patient population free from clinically obvious macrovascular disease.

Adult↗