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Biomedical subjects

D Player

Publications and source records attributed to D Player.

11 recordsLinked to original sources
PubMed2001

Adenosine receptor antagonists and retinal neovascularization in vivo.

PURPOSE: The role of adenosine receptor (AdoR) antagonists in human retinal endothelial cell function in vitro has previously been determined. In this study, efficacy of AdoR antagonist administration in reducing retinal neovascularization was examined in a mouse pup model of oxygen-induced retinopathy. METHODS: A previously described model of oxygen-induced retinal neovascularization in newborn mouse pups was used to examine the effect of various AdoR antagonists on neovascularization. The nonselective AdoR antagonist xanthine amine congener (XAC), the A(2A)-selective antagonist ZM241385, the A(2B)-selective antagonists 3-N-propylxanthine (enprofylline) and 3-isobutyl-8-pyrrolidinoxanthine (IPDX), and the A(1)-selective antagonist cyclopentyl-1,3-dipropylxanthine (CPX) were used. After the hyperoxia exposure the animals received daily intraperitoneal injections of pharmacologically relevant doses of AdoR antagonists for 5 days. Control animals received vehicle (0.1% dimethyl sulfoxide [DMSO]) alone. The animals were then killed and perfused with fluorescein-dextran. Wholemounts of retinas from one eye were prepared and examined, whereas the retinas of the contralateral eye were embedded, sectioned, and stained for counting neovascular nuclei extending beyond the internal limiting membrane into the vitreous. RESULTS: Angiography of wholemount retinas showed reduction of neovascular tufts in animals treated with selective A(2B) AdoR antagonists. Quantification of the extraretinal neovascular nuclei showed that only animals treated with XAC, enprofylline, or IPDX showed a significant reduction in retinal neovascularization. By contrast, neither CPX nor ZM241385 had an effect on neovascularization. CONCLUSIONS: The A(2B)-selective AdoR antagonists inhibited oxygen-induced retinal neovascularization in vivo and may provide a basis for developing pharmacologic therapies for the treatment of proliferative retinopathies.

Angiography↗
PubMed1993

Citizens' advice in general practice.

OBJECTIVE: To examine the introduction of citizens advice bureau sessions into general practice. DESIGN: Prospective survey of 150 consecutive attenders. SETTING: 10 Practices in south Birmingham that volunteered to participate. OUTCOME MEASURES: The social characteristics of the population attending, the problems presented, the social security and other payments obtained, and the health problems mentioned during the sessions. RESULTS: Advice requested covered the whole range offered by the citizens advice bureaus. Thirty nine of 150 attenders obtained payments totalling 58,300.58 pounds for year 1991-2, of which 54,929.58 pounds was recurring. People mentioning health problems were significantly more likely to be entitled to unclaimed benefits. CONCLUSIONS: The provision of citizens advice bureau sessions in general practice is an effective way of providing advice on life problems and securing proper payment of benefits, particularly to patients with health problems. This service complements rather than detracts from other citizens advice bureau activities.

Adolescent↗
PubMed1989

South Birmingham Coronary Prevention Project: a district approach to the prevention of heart disease.

The South Birmingham Coronary Prevention Project is described, in which health checks by practice nurses in GPs' surgeries are combined with direct patient access to a secondary referral system. Where appropriate, health check attenders are offered the choice of either (a) counselling by the practice nurse, (b) direct referral to their GP, or (c) direct referral to secondary intervention, including specialist dietary advice for patients with high (greater than 6.5 mmol/l) serum cholesterol, stress management training for mild hypertension (diastolic blood pressure greater than 90 less than 105 mmHg), and smoking cessation groups. Significant reductions in blood pressure (p less than 0.005) and serum cholesterol levels (p less than 0.001) have been achieved. Further, substantial numbers of smokers have ceased since attending smoking cessation groups. This multidisciplinary approach to the identification and modification of risk factors for coronary heart disease may provide a powerful adjunct to wider ranging population interventions.

Coronary Disease↗
PubMed1988

A multi-disciplinary approach to the prevention of coronary heart disease.

The South Birmingham Coronary Prevention Project is described, in which health checks by practice nurses in GPs' surgeries are combined with direct patient access to a secondary referral system. Where appropriate, health check attenders are offered the choice of either counselling by the practice nurse, direct referral to their GP, or direct referral to secondary intervention, including dietary advice for patients with high serum cholesterol, stress management training for mild hypertension, and smoking cessation groups run by specialist workers. Further developments of the project may be toward increasing areas of nurses intervention, for example running lipid clinics, and combining with Look After Your Heart! in the workplace. Progress in each of these areas is described and discussed.

Coronary Disease↗
PubMed1985

Arachidonic acid and isolated human umbilical vein: concentration-limited prostacyclin generation and absence of direct toxic effects on endothelial integrity.

Previous studies show that administration of high doses of arachidonic acid to rabbits causes disruption of vascular integrity. To examine if similar changes would occur in isolated human vascular tissue, we treated human umbilical veins with arachidonic acid (0, 0.01, 0.1, 1.0 mM). Prostacyclin biosynthesis was quantitated in the supernatants and the endothelial integrity was evaluated by scanning electron microscopy. Prostacyclin synthesis was maximum at low concentrations (0.01-0.1 mM) with no additional increase with higher concentrations of arachidonic acid (1mM) confirming previous observations. There was no evidence for endothelial disruption with any concentration of arachidonic acid. This study shows that arachidonic acid has no direct effects on the vascular lining of isolated human umbilical vein, arachidonic acid-induced sudden death in experimental animals is not due to limitation of prostacyclin synthesis.

Arachidonic Acid↗
PubMed1985

Decreased platelet aggregation but increased thromboxane A2 generation in polycythemia vera.

Patients with polycythemia vera have been described to have hemorrhagic as well as thrombotic tendencies. In a patient with polycythemia vera and angina pectoris, we observed markedly decreased platelet aggregation response to epinephrine but increased platelet and whole-blood thromboxane A2 generation compared with normal subjects. Electron microscopy mostly showed partially activated forms of platelets, which may account for decreased aggregation response in vitro and hemorrhagic tendencies. Young and large platelets found in this disease, however, can generate large amounts of vasoconstrictor and platelet proaggregatory prostanoid thromboxane A2 in response to endogenous thrombin, which may be a basis for thrombotic tendencies.

Angina Pectoris↗