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Biomedical subjects

M Barry

Publications and source records attributed to M Barry.

At least 19 recordsLinked to original sources
PubMed2006

Electrical control of antiferromagnetic domains in multiferroic BiFeO3 films at room temperature.

Multiferroic materials, which offer the possibility of manipulating the magnetic state by an electric field or vice versa, are of great current interest. In this work, we demonstrate the first observation of electrical control of antiferromagnetic domain structure in a single-phase multiferroic material at room temperature. High-resolution images of both antiferromagnetic and ferroelectric domain structures of (001)-oriented multiferroic BiFeO3 films revealed a clear domain correlation, indicating a strong coupling between the two types of order. The ferroelectric structure was measured using piezo force microscopy, whereas X-ray photoemission electron microscopy as well as its temperature dependence was used to detect the antiferromagnetic configuration. Antiferromagnetic domain switching induced by ferroelectric polarization switching was observed, in agreement with theoretical predictions.

Journal Article↗
PubMed2006

Adrenoceptor blockade alters plasma gelatinase activity in patients with heart failure and MMP-9 promoter activity in a human cell line (ECV304).

This study assessed the effects of short-term adrenoceptor blockade on plasma matrix metalloproteinase (MMP) activity in patients with heart failure, and the ability of adrenoceptor stimulation to modulate matrix metalloproteinase-9 (MMP-9) promoter activity in vitro. Patients with heart failure received standard therapy or standard therapy plus carvedilol. Plasma MMP activity was determined by zymography and tissue inhibitor (TIMP-1) expression was measured by immunoblotting. MMP-9 promoter activity was assessed in transfected ECV304 cells following exposure to isoprenaline or phenylephrine in the absence or presence of either propranolol or prazosin. In patients with heart failure, carvedilol attenuated the increase in proMMP-9 activity observed at 4 and 12 weeks in non-beta-blocker-treated patients (44.0 +/- 4.9 AU versus 60.8 +/- 6.7 AU; P < 0.05). Although TIMP-1 expression was unaltered, the MMP-9:TIMP-1 ratio was lower in those receiving carvedilol at 4 and 12 weeks (0.54 +/- 0.07 versus 1.04 +/- 0.17; P < 0.05). Isoprenaline transiently increased MMP-9 promoter activity after 4 h exposure (80.6 +/- 14.8-fold; P < 0.001) before returning to baseline. The response to isoprenaline was prevented by propranolol (P < 0.01). Phenylephrine caused a biphasic increase in MMP-9 promoter activity, with the greatest increase occurring at 24 h (23 +/- 3.7-fold) compared to baseline. This response was unaffected by co-incubation with prazosin. In conclusion, treatment with a mixed alpha1/beta-adrenoceptor antagonist attenuates MMP activity and tips the degradative balance to a less degradative phenotype in heart failure patients. Furthermore, adrenoceptor stimulation increases MMP-9 promoter activity, which is inhibited by beta- but not alpha-adrenoceptor blockade. Therefore, mixed adrenoceptor blockade may reduce remodeling in heart failure as a direct consequence of a beta-adrenoceptor-mediated reduction in MMP-9 transcription.

Adrenergic alpha-Antagonists↗
PubMed2006

Relationship between locking-bolt torque and load pre-tension in the Ilizarov frame.

The wire-bolt interface in an Ilizarov frame has been mechanically tested. The optimal torque to be applied to the frame locking-bolts during physiological loading has been defined. The set-up configuration was as is used clinically except a copper tube was used to simulate bone. The force-displacement curves of the Ilizarov wires are not altered by locking-bolt torque. The force in the bone model at which pre-tension is lost increases as the locking-bolts are tightened to 14 Nm torque, but decreases if torque exceeds 14 Nm. Thus, 14 Nm is the optimal locking-bolt torque in frame. The relationship between pre-tension versus load for different locking-bolt torques arises because at low and high clamping torques poor wire holding and plastic deformation respectively occur. Wire damage was seen under light and electron microscopy. Clinically, over or under-tightening locking-bolts will cause loss of pre-tension, reduction in frame stiffness and excessive movement at the fracture site, which may be associated with delayed union.

Biomechanical Phenomena↗
PubMed2006

A new look at an under-diagnosed poorly treated condition: restless legs syndrome.

Restless legs syndrome (RLS) is a common condition that is difficult to diagnose. However, once correctly diagnosed, its management is straightforward and evidence-based. The purpose of this article is to familiarise clinicians with both the symptoms and diagnostic criteria for RLS and to elucidate secondary and often curable causes of this prevalent condition. There is also a concise review of its pathophysiology and current management strategies. The authors hope this article will raise awareness of this condition among clinicians and in doing so improve the quality of life for the patients affected by it.

Dopamine Agents↗
PubMed2006

The rising cost of glaucoma drugs in Ireland 1996-2003.

BACKGROUND: Glaucoma affects approximately 2% of the population in developed countries and is estimated to affect 67 million people worldwide. The authors investigated the effect of the introduction of new medications on the volume and cost of drugs for glaucoma in two countries, Northern Ireland (NI, population approximately 1.7 million) and the Republic of Ireland (ROI, population approximately 3.9 million) in the 8 years from 1996 to 2003. They also looked at the surgical rates for glaucoma within the same time period for the two countries. METHODS: A retrospective analysis was performed of drug costs, prescribing data, and operation rates for glaucoma in Ireland from January 1996 to December 2003. Information regarding costs and volume were obtained for each type of glaucoma drug and these were then grouped into the glaucoma treatment subsections as found in the British National Formulary. The drug information was obtained from the Central Services Agency in NI and IMS Health in the ROI and included both public and private prescriptions. The information on surgical rates for glaucoma was obtained from the Department of Health and Social Services in NI and the Hospital In-patient Enquiry (HIPE) data national files in the ROI. RESULTS: There was a 30% increase in prescription items for glaucoma in NI and a 59% increase in the ROI from 1996 to 2003. The costs increased more rapidly than the number of items: 227% in the ROI and 78% in NI from January 1996 to December 2003. In the ROI, there was an average 19% year on year increase in costs. In NI, new drugs accounted for 40% of the quantity of prescription items for glaucoma and 63% of the market cost in 2003. In the ROI new drugs accounted for 57% of the quantity and 77% of the market cost for glaucoma in 2003; prostaglandin analogue drugs alone accounted for 53% of the cost. The number of trabeculectomies performed decreased by more than 60% in both countries. CONCLUSION: Volume and cost of glaucoma drugs increased dramatically in both NI and the ROI from 1996 to 2003, probably the result of a combination of changing demographics and a changing approach towards the management of patients with glaucoma and ocular hypertension. In 2003 in the ROI, prostaglandin analogues were the most commonly prescribed class of drug for patients with glaucoma and/or ocular hypertension causing a profound rise in drug expenditure.

Adrenergic beta-Antagonists↗
PubMed2006

"Best practice' for Helicobacter pylori eradication in the primary care setting.

This study determined the relative cost effectiveness of proton pump inhibitor (PPI) based triple therapy regimens for Helicobacter pylori eradication in the primary care setting. Using decision tree analysis the expected cost for each H. pylori eradication strategy was determined from the cost of each treatment option multiplied by the probability of that option occurring. Probabilities were obtained using the GMS prescribing database where all patients who received amoxycillin, clarithromycin and a PPI in the ERHA region in 2002 were followed for one year. Depending on the regimen adopted, 40.8% to 46.1% of patients did not require any further medication in the year following H. pylori eradication treatment. The strategy of rabeprazole, amoxycillin and clarithromycin was the most cost effective option with a cost of Euro466 per asymptomatic patient. Two-way sensitivity analysis indicated that the cost of rabeprazole triple therapy and the duration of rabeprazole maintenance therapy would each have to increase by 30% before this strategy ceased to be the most cost effective and hence best practice option for eradicating Helicobacter pylori in the primary care setting in Ireland.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2006

Cost effectiveness of statin therapy for the primary prevention of coronary heart disease.

Cholesterol lowering statin therapy accounted for over 10% of total drug acquisition costs (87.5 million euros) under the Community Drugs Schemes in Ireland in 2004. Not surprisingly, the issue of value for money and cost effectiveness arises. Whilst statin therapy has proven cost effective in patients with established cardiovascular disease this is the first economic evaluation of statin therapy for primary prevention in the Irish healthcare setting. Using economic modelling techniques the incremental cost effectiveness of statin therapy in high risk individuals i.e. 10 year risk exceeding 15% ranged from 17,900 euros per life year gained (LYG) to 33,800 euros/LYG under the GMS scheme. Corresponding figures for the Drug Payment scheme were 24,500 euros/ LYG to 48,500 euros/LYG. All the statins could be considered cost effective i.e. threshold below 50,000 euros/LYG however atorvastatin proved the most cost effective statin in this pharmacoeconomic study.

Coronary Disease↗
PubMed2005

Virtual reconstruction and morphological analysis of the cranium of an ancient Egyptian mummy.

A mummy of an Egyptian priestess dating from the 22nd dynasty (c. 770 BC), completely enclosed in an anthropoid (human shaped) coffin, was scanned on a CT scanner. An accurate reconstruction of the cranium was generated from 115 x 2 mm CT images using AVS/Express on a SGI computer. Linear measurements were obtained from six orthogonal cranial views and used in a morphometric analysis software package (CRANID). The analyses carried out were both linear and nearest neighbour discriminant analysis. The results show that there is a 52.9% probability that the mummy is an Egyptian female, with a 24.5% probability that the mummy is an African female. Thus the technique confirms that the coffin contains an Egyptian female, which is consistent with the inscription on the coffin and the shape of the pelvic bones as revealed by plain X-rays. These results show that this technique has potential for analysing forensic cases where the bones are obscured by soft tissue and clothing. This technique may have an application in virtual autopsies.

Archaeology↗
PubMed2005

A randomized controlled trial of an asthma clinical pathway for children in general practice.

AIMS: To evaluate the effect of the implementation of an asthma clinical pathway on asthma in children in general practice. METHODS: A randomized, controlled trial involving 270 general practitioners. One group of general practitioners implemented the asthma clinical pathway for children (intervention group) and the control group continued with their usual asthma medical care management. The main outcome measures were admissions to hospital for asthma and attendance at the Children's Emergency Department. Compliance with the guidelines was assessed by examining asthma drug prescriptions. RESULTS: Admissions to hospital for asthma dropped 40% in the intervention group, by 33% in the control group and by 22% in general practitioners not participating in the trial. The differences between the intervention and control and between the intervention and non-participating general practitioners were not statistically significant. The decrease in attendance at the Children's Emergency Department decreased by 25%, 30% and 19%, respectively, but this was not statistically significant. There was a significant decrease in prescriptions for oral relievers, dry powder relievers in the under 6s, mast cell stabilizers and methylxanthines in both control and intervention groups. However, only for oral relievers was there a significant difference between the intervention group and control, with the decrease larger in the intervention group (p < 0.001). CONCLUSIONS: Admissions to hospital for asthma decreased, as did attendance at the Children's Emergency Department. Prescriptions for asthma medication changed in the direction anticipated with compliance with the asthma clinical pathway. However, we found no evidence within the study that implementation of the asthma clinical pathway by general practitioners resulted in lower morbidity than those general practitioners who did not implement the pathway. Possible explanations are that these general practitioners were already providing care according to the recommendations of the pathway, or that there was contamination of the control group by the intervention, or that the guidelines, although based on currently accepted recommendations, are ineffective.

Adolescent↗
PubMed2005

Cost effective prescribing of proton pump inhibitors (PPI's) in the GMS Scheme.

Total expenditure under the Community Drugs Schemes in Ireland on the proton pump inhibitors (PPI's) used for the management of patients with dyspepsia was approximately 64 million Euro in 2002, an 8-fold increase since 1995. As PPI maintenance therapy accounts for the majority of this expenditure we determined potential cost savings to the GMS scheme should the prescribing of these drugs for maintenance therapy follow published clinical and cost effectiveness guidelines. Substitution, in accordance with therapeutic indication, of the PPI with the greatest individual cost i.e. omeprazole (Losec Mups) with any of the alternative agents particularly the generic omeprazole preparations Ulcid & Lopraz, rabeprazole (Pariet) and pantoprazole (Protium) would be expected to produce cost savings in excess of 5 million Euro per annum. These savings may be further enhanced by increasing the step down from healing to maintenance doses of these drugs.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2004

Prescribing trends for nicotine replacement therapy in primary care.

Nicotine replacement therapy (NRT) has been available free of charge for medical cardholders in Ireland (29.84% of the population) since April 2001. We investigate the prescribing patterns for NRT before and after this change in reimbursement status. Using the General Medical Services Payments Board prescription database we conducted a detailed analysis of NRT prescribing (ATC code N07BA) for those patients eligible for free medications (1,168,745 patients) in all health board areas in Ireland from January to December 2002. We determined the number of monthly prescriptions for each NRT preparation (ATC code N07BA01) and bupropion (ACT code N07BA02) together with total expenditure. The mean dosage, duration of therapy and age/gender distribution of NRT treatment was also obtained. We identified 49,826 patients who received smoking cessation products in 2002. Of these 94.6% (47,147 patients) were prescribed NRT, the remaining 5.4% (2,679 patients) received bupropion. Nicotine patch therapy accounted for 82.8% of all NRT dispensed. Prescribing trends for NRT show the number of patients receiving such therapy is greatest in January and February with expenditure highest in the first quarter. Prescribing of NRT is greatest amongst the 25-54 year age group with peak prescribing between the ages of 35-44 years. The highest dose of nicotine patch therapy (15-21 mg/day) was prescribed for the majority (73%) of patients. Over three quarters (75.6%) of all patients were prescribed nicotine patch therapy for a period of less than or equal to 4 weeks (48.1% less than or equal to 2 weeks). Similarly for nicotine gum where 77% of all patients received just one month of therapy. This analysis indicates quality NRT prescribing in the primary care setting. The dose and duration of therapy is in keeping with recent NICE guidance indicating that the NRT expenditure of 2,709,954 euros in 2002 should provide value for money.

Adult↗