Biomedical subjects

A D Edwards

Publications and source records attributed to A D Edwards.

129 records · Page 8Linked to original sources

PubMed1984

Cholinergic supersensitivity and decreased number of muscarinic receptors in atria from short-term diabetic rats.

Autonomic neuropathy is a major complication of chronic diabetes and is responsible for disturbances in the cardiovascular system and other organs. Early cardiac disturbances have been attributed to defective vagal control of the heart. The heart rates of rats with chemically-induced diabetes are depressed and an increase in blood pressure produces a greater reflex bradycardia in diabetic rats. Tomlinson and Yusof found that isolated, stimulated left atria from rats made diabetic with alloxan are supersensitive to the negative inotropic influence of acetylcholine. On the other hand, Rao, et al. found that perfused working-heart preparations from streptozotocin- and alloxan-diabetic rats have a reduced sensitivity to carbamylcholine. In the present study, we measured chronotropic responses to cholinergic agonists of isolated, spontaneously-beating atria, as well as muscarinic receptor populations, in cardiac tissue from short-term (8 to 9 weeks) diabetic and age-matched control rats.

Animals↗

PubMed1983

The effect of increased lung volume on the expiratory rate of rise of alveolar carbon dioxide tension in normal man.

The rate at which alveolar PCO2 (PA, CO2) rises during expiration has been measured in seven healthy medical students. PA, CO2 rate of rise [delta PA, CO2/delta t] was measured by a method utilizing constant expiratory flow rates in individual breaths in two subjects, and was calculated from airway PCO2 and expiratory tidal volume in the remaining five subjects. Steady-state runs were recorded at two or more metabolic rates with the subject making no special effort to control mean lung volume. This was done to establish the relationship between delta PA, CO2/delta t and the rate of CO2 production (VCO2) at normal lung volume in individual subjects. Steady-state runs were also recorded at high lung volume. In each subject delta PA, CO2/delta t was less than would have been obtained at normal lung volume. Inversion of a hypothetical relation between delta PA, CO2/delta t, VCO2 and average lung volume (VLa; DuBois, Britt & Fenn, 1952) yielded calculated values of VLa for both the normal and the high lung volume states. Lung gas volume was measured in a whole body plethysmograph, ('box volume') both for the normal and high lung volume states, in each subject. Mean VLa and 'box volume' estimates showed only moderately good agreement, whereas the estimated differences between normal and high lung volume obtained by the two methods were virtually identical. These experiments suggest that the expiratory PA, CO2 rate of rise is determined, in the steady state, partly by the rate of CO2 production (a directly proportional relationship) and partly by the mean lung volume (an inversely proportional relationship).

Carbon Dioxide↗

PubMedDate not supplied

The role of systemic lidocaine in neuropathic pain management.

Pain management is rapidly changing as the mysteries of how healthy and damaged nervous systems work to communicate pain to the brain become better understood. The role of subcutaneous or intravenous lidocaine in the management of neuropathic pain has been increasingly studied. Patients with a variety of pain have been shown to benefit from this therapy, including patients with cancer, postherpetic neuralgia, second degree burns, strokes, and diabetes. As research and experience grow, so too will the practitioner's ability to successfully use intravenous and subcutaneous lidocaine therapy for their patients with pain.

Anesthetics, Local↗