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Biomedical subjects

A H Morice

Publications and source records attributed to A H Morice.

At least 19 recordsLinked to original sources
PubMed2002

Testosterone acts as a coronary vasodilator by a calcium antagonistic action.

T acts as a vasodilator in vitro and in vivo. Supplemental T therapy in humans with angina improves symptoms and reduces objective measures of ischemia. In left anterior descending coronary arteries taken from adult male Wistar rats, T abolishes 100+/-4.2% of calcium-dependent contraction induced by potassium chloride, 82.3+/-6.1% of the mostly calcium-dependent contraction induced by prostaglandin-F-2-alpha, but only 45.3+/-3.4% of the contraction induced by phorbol-12,13-dibutyrate (PDBu) in the presence of extracellular calcium, and 54.5+/-4.5% of the contraction induced by PDBu in the absence of extracellular calcium. These findings suggest that T is primarily inhibiting the calcium-dependent elements of vascular contraction.

Animals↗
PubMed2002

Patients' and carers' preferences in two models of care for acute exacerbations of COPD: results of a randomised controlled trial.

BACKGROUND: Patients with an acute exacerbation of chronic obstructive pulmonary disease (COPD) were randomised to either hospital at home (HaH) or inpatient management, and patient and carer preferred site of management and satisfaction with care received in the two arms was determined. METHODS: Emergency admissions with an acute exacerbation of COPD were randomised to inpatient care or HaH care. After discharge an independent observer administered a questionnaire to both patients and carers on the preferred site of care and scored satisfaction with the care received. RESULTS: Of 60 patients recruited, 30 were randomised to receive HaH care. Retrospective patient preference for HaH care was 96.3% in the domiciliary arm and 59.3% in the conventional arm; carer preference figures were 85.7% and 42.9%, respectively. There was a higher preference for domiciliary care by both patients and carers in the HaH arm than in the inpatient arm (p=0.001 and p=0.01, respectively). Patients recorded equal satisfaction with care in the two arms (88.1% in the conventional arm, 91.7% in the domiciliary arm); carer scores were 91.3% and 91.9%, respectively. CONCLUSIONS: The results of this study show that both patients and carers were significantly more likely to prefer domiciliary care if they were in the HaH arm. Since patients had to be willing to be looked after at home, both patients' and carers' perceptions of the benefits of HaH care were reinforced by their experience. HaH care of acute exacerbations of COPD is the preferred option in suitable patients.

Acute Disease↗
PubMed2001

The placebo response to citric acid-induced cough: pharmacodynamics and gender differences.

Characteristics of the response to placebo in a citric acid-induced cough challenge were investigated as part of a randomized, double-blind crossover trial to assess the antitussive effect of dextromethorphan. Baseline cough responses were established on two occasions in 22 healthy subjects. They received 60 ml placebo antitussive syrup and cough frequency following five inhalations of 10% citric acid over 5 min was measured at regular intervals up to 12 h. Response-time models of varying complexity were used to describe the placebo cough suppression data. The cough response to placebo was also compared to that of the untreated state. The placebo cough response was best characterized by a non-linear increase in cough suppression up to a maximum reduction of 1.6 coughs from baseline at 4-4.5 h, followed by a non-linear return to baseline. The cough response in the untreated state was not different from that of placebo (P=0.99). Females coughed more frequently than males (median number of coughs=10.5 vs. 9.0, respectively P<0.001; Mann-Whitney U test), and adaptation to the cough stimulus was significantly more rapid in females (P<0.025). Accordingly, in trials that use citric acid-induced cough, gender should be considered in study design, particularly in relation to the timing of measurements.

Administration, Inhalation↗
PubMed2001

The role of the asthma nurse in treatment compliance and self-management following hospital admission.

Effective self-management and treatment compliance is important in achieving good symptom control in asthma. The aim of this study was to determine whether asthma nurse intervention during hospital admission could increase knowledge and improve self-management and whether this would influence the number of emergency call-out visits by Genera Practitioners (GPs) and hospital re-admissions. Patients with acute asthma (n=80) were assessed by the asthma nurse within 24 h of admission using a British Thoracic Society (BTS) guideline-based questionnaire. Main outcome measures were: know edge of inhalers, self-management plans, peak flow monitoring, recognition of worsening symptoms and appropriate emergency action, Following randomization, half received nurse intervention during hospitalization. All received a follow-up questionnaire 6 weeks post-discharge and again at 6 months (response rates 86% and 81% respectively). GPs were contacted by postal questionnaire after 4 months. Questionnaire responses indicated an increase in knowledge in the intervention group, along with an ability to identify appropriate action on worsening symptoms. Emergency GP call-outs were more frequent in the control group in the 4 months post-discharge. Hospital re-admission rates were similar in both groups. Asthma nurse intervention appeared to increase knowledge of asthma management, maintained throughout the study period, but had no significant impact on reducing re-admissions to hospital.

Adolescent↗
PubMed2001

Gender differences in the vasomotor effects of different steroid hormones in rat pulmonary and coronary arteries.

It is well recognised that oestrogens possess vasodilatory properties, and similar responses to testosterone have been demonstrated. However, vasomotor effects of other steroid hormones have not been well described. Direct comparisons of the relative vasoactivity of different steroid hormones in different vascular beds in male and female genders have not been made. Coronary and pulmonary arteries from adult Wistar rats were mounted in a wire myograph, loaded to 100 and 17 mmHg respectively, maximally pre-contracted with 1 x 10(-4) M prostaglandin-F-2-alpha, and dose response curves to 1 x 10(-6) to 1 x 10(-3) or 3 x 10(-3) M of 17 beta-oestradiol, testosterone, progesterone, and cortisol dissolved in water were constructed. Addition of each steroid hormone caused acute, dose dependent dilatation in coronary and pulmonary vessels. In coronary arteries the order of activity was testosterone > progesterone > 17 beta-oestradiol > cortisol, p < 0.001. In pulmonary arteries, the order of activity was progesterone > testosterone > cortisol > 17 beta-oestradiol, p < 0.001. Pulmonary arteries from male animals were more sensitive to the effects of testosterone than those from female animals, p = 0.003, whereas coronary arteries from female animals were more sensitive to the effects of 17 beta-oestradiol than those from male animals, p < 0.001. We have demonstrated significant differences in the in vitro vasomotor effects of different steroid hormones in two distinct vascular beds. Gender differences in vasomotor responses to steroid hormones may play a role in the aetiology of vasospastic diseases.

Animals↗
PubMed2001

CFC transition.

Explore the source record for details and available documents.

Anti-Asthmatic Agents↗
PubMed2000

NADPH oxidase: a universal oxygen sensor?

NADPH oxidase is classically regarded as a key enzyme of neutrophils, where it is involved in the pathogenic production of reactive oxygen species. However, NADPH oxidase-like enzymes have recently been identified in non-neutrophil cells, supporting a separate role for NADPH-oxidase derived oxygen species in oxygen sensitive processes. This article reviews the current literature surrounding the potential role of NADPH oxidase in the oxygen sensing processes which underlie hypoxic pulmonary vasoconstriction, systemic vascular smooth muscle proliferation, carotid and airways chemoreceptor activation, erythropoietin gene expression, and oxytropic responses of plant cells.

Animals↗
PubMed2000

The effect of the nitric oxide synthase inhibitor N-gamma-nitro-L-argine methyl ester on hypoxic pulmonary vasoconstriction.

We studied the role of nitric oxide in the regulation of pulmonary arterial tone and hypoxic pulmonary vasoconstriction. Rat pulmonary arteries (n=65, diameter=440+/-12 microm) were loaded to 17.5 mm Hg in a wire myograph and incubated with the nitric oxide synthase inhibitor N-gamma-nitro-L-argine methyl ester (L-NAME; 1, 10 or 100 microM) or distilled water (50 microl) prior to preconstriction with either 100 microM prostaglandin F(2 alpha) followed by acetylcholine (0.1-100 microM) or 5 microM prostaglandin F(2 alpha) followed by hypoxia. Concentrations of L-NAME (10 and 100 microM) which attenuated acetylcholine dilatation, elevated basal tone from 0. 2+/-0.5% to 9.4+/-2.1% (P<0.01) and 18.3+/-3.2% (P<0.001), respectively, potentiated contraction to 5 microM prostaglandin F(2 alpha) from 35.9+/-3.1% to 56.2+/-6.8% (P<0.05) and 66.4+/-5.8% (P<0.001), respectively, but had no significant effect on hypoxic pulmonary vasoconstriction. This suggests basal pulmonary nitric oxide release occurs, as well as in response to agonist-induced contraction, but not hypoxic pulmonary vasoconstriction.

Animals↗
PubMed2000

Hydrogen peroxide--an intracellular signal in the pulmonary circulation: involvement in hypoxic pulmonary vasoconstriction.

Hypoxic pulmonary vasoconstriction (HPV) is a regulatory feature of the pulmonary circulation that ensures consistent matching of perfusion to ventilation in the normal lung. However, under pathophysiological conditions, HPV contributes to the elevated pulmonary arterial pressure inherent to numerous disease states. Consequently, control of HPV is an avenue of potential therapy for such conditions. This review discusses the role of hydrogen peroxide (H(2)O(2)) as an intracellular signal in the pulmonary circulation, concentrating on the potential involvement of H(2)O(2) in HPV and in the control of pulmonary arterial tone. Sites of hypoxic pulmonary arterial H(2)O(2) production include the mitochondrial electron transport chain, a microsomal electron transport chain containing an NADH oxidoreductase and alternatively, a membrane-bound NADPH oxidase. Each of these sources of H(2)O(2) and the effect of hypoxia on the production of reactive oxygen species are considered. The review also discusses the variance in vascular reactivity of H(2)O(2), which is described to elicit both pulmonary arterial vasoconstriction and dilatation at varying concentrations. The redox capabilities of H(2)O(2) are also considered. The relevance of all of these actions of H(2)O(2) are also assessed as potential pharmacological targets for the future development of therapy for lung diseases that are characterised by some degree of HPV and in the pathogenesis of pulmonary diseases in which reactive oxygen species are implicated.

Humans↗