Biomedical subjects
Publications and source records attributed to P Cook.
Two patients with toxic reactions to prochlor-perazine (Compazine) prescribed as an antiemetic are presented. The authors caution against wrongfully labeling such patients as having psychiatric disturbances when the cause is iatrogenic.
Having a mild upper respiratory tract infection does not change the sleep rate proportions or total sleep time of an infant. However, infants with colds exhibit some sleep state specific alterations in sleep apnea. At 40, 44, and 48 weeks postconception, the number of respiratory pauses of 2 to 4.9 seconds and of 5 to 9.9 seconds duration per 100 minutes of state, during rapid eye movement, and indeterminate sleep are decreased in infants with colds. The absence of this phenomenon at 52 weeks suggests that it is modified by maturation. We hypothesize that the reduction in rapid eye movement and indeterminate sleep apnea is a manifestation of an adaptive response in normal infants, but for infants at risk for the sudden infant death syndrome, this response may be overwhelmed, resulting in increased apnea and, in some instances, sudden infant death.
Ouabain-sensitive Na+ and K+ fluxes and ATP content were determined in high potassium sheep erythrocytes at different values of membrane potential and internal pH. Membrane potential was adjusted by suspending erythrocytes in media containing different concentrations of MgCl2 and sucrose. Concomitantly either the external pH was changed sufficiently to maintain a constant internal pH or the external pH was kept constant with a resultant change of internal pH. The erythrocytes were preincubated before the flux experiment started in a medium which produced increased ATP content in order to avoid substrate limitation of the pump. It was found that an increased cellular pH reduced the rates of active transport of Na+ and K+ without significantly altering the ratio of pumped Na+/K+. This reduction was not due to limitation in the supply of ATP although ATP content decreased when internal pH increased. Changes of membrane potential in the range between -10 and +60 mV at constant internal pH did not affect the rates of active transport of Na+ or K+.
Sleep-awake state distribution during inter-feed intervals over a 24-hour period on the third day of life was investigated by means of a continuous non-intrusive bassinet sleep monitor. 31 infants were studied: 14 born to mothers who drank heavily throughout pregnancy (group A), eight whose mothers modified their heavy drinking (group B) and nine whose mothers never were heavy drinkers (group C). Over the 24-hour period, group A infants slept less than those in group B. In comparison with group C, group A infants had a larger proportion of quiet sleep episodes interrupted by awake or unclassified epochs, and were more restless, with more frequent major body movements. These pilot observations suggest that heavy maternal consumption of alcohol, when continued throughout pregnancy, is associated with a disturbance of sleep-awake state distribution. Successful therapy of heavy drinking during pregnancy may improve the physiological competence of the newborn to regulate sleep-awake states and facilitate interaction between mother and infant.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The effect of catecholamines and adrenergic blocking agents on the transport of Cl- and Na+ of the isolated frog cornea was studied. Cl- transport was stimulated by the three catecholamines tested at 10(-6) to 10(-5) M concentration. The stimulation produced by 10(-6) M epinephrine was partially inhibited by both the alpha-blocker phentolamine and the beta blocker propranolol. The stimulation produced by 10(-6) M isoproterenol was not affected by 10(-5) M phentolamine but was completely prevented by 10(-5) M propranolol. The stimulation produced by 10(-5) M norepinephrine was completely blocked by the 10(-5) M propranolol and partially by 10(-5) M phentolamine. Catecholamines had no effect on the normally small Na+ transport. When the Na+ transport was previously increased by amphotericin B, epinephrine and isoproterenol produced a small and inconsistent stimulatory effect. Norepinephrine was without effect. It is concluded that both alpha- and beta-adrenergic receptors are present in the frog cornea and that the Cl- transport is increased by the stimulation of either receptor. The minimal effect on the Na+ transport further suggests the separation of pathways of the Cl- and Na+ transport in the frog cornea.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The oesophagus is the most common site of tumour development in men in parts of eastern and southern Africa. In West Africa cancer of the oesophagus is practically unknown. In the areas where it is common, the frequency is not uniformly high but shows sharp gradients within short distances. Most of the present high frequencies seem to have developed from a negligible incidence 30 or forty years ago. In all areas the disease is more common in men than women but the sex ratio varies from less than 2: 1 to 12: 1. Alcohol has been shown to be implicated in the development of cancer of the oesophagus elsewhere in the world. Home-made beer and spirit are common in many parts of Africa but there is no geographical association between frequency of consumption and the occurrence of oesophageal cancer. Evidence exists which suggests that both the geographical and temporal distributions in Africa could reflect the use of maize as a major ingredient of alcoholic drinks.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.