PubMed Health⌕ Search

Biomedical subjects

John Connor

Publications and source records attributed to John Connor.

4 recordsLinked to original sources
PubMed2005

Blood pressure lowering effect of olive is mediated through calcium channel blockade.

Olive (Olea europea) is used in traditional medicine as a remedy for hypertension. The aqueous-methanolic crude extract of O. europea fruit (OeF.Cr) was studied in anaesthetized rats and its possible mechanism was elucidated using isolated cardiovascular preparations. Intravenous administration of OeF.Cr produced a dose-dependent (30-100 mg/kg) fall in arterial blood pressure in normotensive anaesthetized rats. This effect remained unaltered in atropinized animals. In the in vitro studies OeF.Cr (0.1-3.0 mg/ml) inhibited spontaneously beating guinea-pig atria. Moreover, it relaxed K+ and/or phenylephrine-induced contractions of rabbit aortic preparations over a dose range of 0.1-3.0 mg/ml, suggesting calcium channel blockade (CCB). The CCB effect was confirmed when pretreatment of the vascular preparations with OeF.Cr produced a dose-dependent rightward shift of the Ca2+ dose-response curves, similar to verapamil. These results suggest that the blood pressure lowering effect of olive is mediated through CCB, justifying its use in hypertension.

Animals↗
PubMed2005

The role of the registered nurse in an acute mental health inpatient setting in New Zealand: perceptions versus reality.

Following the closure of the large psychiatric institutions in New Zealand, there is an increasing demand for limited beds in acute inpatient facilities for acutely mentally ill patients. This change in location and downsizing of acute inpatient beds has challenged traditional roles of mental health nursing, resulting in confusion over what roles mental health nurses should now perform in the new context of care. This study compared the perceptions that registered psychiatric nurses have of their roles with their actual practice. This qualitative descriptive exploratory study observed nursing practice on three selected wards and used focus group interviews to establish from registered nurses what they perceived their roles to be. A key finding of this study was that many of the nursing roles related to delivering care from a crisis management perspective, which covers aspects such as assessment, stabilization of symptoms and discharge planning. Participants also believed that the therapeutic relationship was a fundamental role in inpatient care. Nurses used any opportunity to make it a reality such as kitchen organization, medications, or dealing with a challenging patient. This study highlighted the complexity of the roles that nurses performed and went some way to give voice to what at times seems an invisible practice.

Acute Disease↗
PubMed2002

Direct visualization of trapped erythrocytes in rat brain after focal ischemia and reperfusion.

Partial microcirculatory stasis after cerebral ischemia and reperfusion is a potential factor in delayed cell death. Sometimes described as the "no-reflow" phenomenon, limitations in current detection techniques have left the extent and spatial distribution of the phenomenon undetermined, which has led to some doubt as to its actual existence. The authors describe a new method, based on erythrocyte autofluorescence, that allows the erythrocytes trapped in the microvasculature, and thus blocking recirculation, to be directly visualized. Using this method, the authors have examined the spatial and temporal characteristics of this phenomenon in the rat intraluminal model of cerebral ischemia and reperfusion. Up to 15% of the capillaries in the ischemic penumbra remained occluded at least 2 hours after reperfusion. The amount of capillary bed showing trapped erythrocytes was more severe in the ischemic penumbra region than in the ischemic core. These results indicate that the no-reflow phenomenon may contribute to the developing damage in ischemic penumbra region, leading to additional injury after reperfusion.

Animals↗