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D Cameron

Publications and source records attributed to D Cameron.

135 records · Page 8Linked to original sources
PubMedDate not supplied

The influence of habitual alcohol intake on breath-alcohol concentrations following prolonged drinking.

Fifty-one healthy men aged 20-35 years kept daily drinking diaries for 4 weeks prior to a 90-min drinking session of 1 ml of ethanol/kg body weight, taken as 4% alcohol by volume lager, at a constant rate, whilst fasting. This was followed by repeat breath-alcohol measurements for 90 min. Habitually light drinkers had significantly lower breath-alcohol levels than heavier drinkers up to 10 min post-drinking. Variation in breath-alcohol level was independent of habitual intake 15-90 min post-drinking. However, habitually light drinkers still had significantly lower blood-alcohol levels than heavy drinkers 30 min post-drinking. Group mean post-drinking breath-alcohol levels peaked at 20 min in light and moderate drinkers, at 10 min in heavy drinkers and at 5 min in very heavy drinkers. Wide individual variation in peak and rate of decline of breath-alcohol levels occurred independently of habitual intake and despite experimental control for factors influential on alcohol kinetics. Algorithms for alcohol intake and breath concentrations have limited application if drinking is prolonged. We suggest that preabsorptive metabolism and/or delayed absorption of alcohol may contribute to lower breath-alcohol levels in habitually light drinkers for 10 min following alcohol intake under the conditions of this study.

Adult↗
PubMedDate not supplied

Hemodynamic profile of a new antihypertensive agent D,L-3-[2-(3-t-butylamino-2-hydroxypropoxy)phenyl]-6-hydrazinopyridazine (SK&F 92657).

The properties of a new antihypertensive agent, SK&F 92657, D,L-3-[2-(3-t-butylamino-2-hydroxypropoxy)phenyl]-6-hydrazinopyridazine, have been studied. The compound, given intravenously, subcutaneously, or orally, caused a sustained fall in systemic blood pressure of conscious genetically hypertensive rats, normotensive cats, and renal hypertensive dogs. The fall in blood pressure of genetically hypertensive rats was maintained during 52 days of chronic dosing with no development of tolerance. The hemodynamic effects and mechanism of action of SK&F 92657 were investigated in anesthetized cats and dogs using a variety of techniques. Blood pressure was lowered by a direct vasodilator effect on precapillary blood vessels (arteries, arterioles), particularly in the renal, coronary, and skeletal muscle vasculatures, giving an overall decrease in total peripheral resistance with no significant change in cardiac output. In contrast, SK&F 92657 had no significant effect on capacitance blood vessel (veins, venules) tone or on vascular reactivity to vasoconstrictors and consequently did not cause postural hypotension. The beta-adrenoceptor-blocking actions of the drug prevented reflex increases in heart rate and cardiac output, except in the conscious dog, where vagal control of heart rate was predominant. It was also concluded that SK&F 92657 was not acting by alpha-adrenoceptor blockade, ganglion blockade, or inhibition of angiotensin II responses. A "central" action was unlikely, as SK&F 92657 caused vasodilatation in denervated autoperfused vascular beds.

Animals↗
PubMedDate not supplied

Swallowing disorders following acute stroke: prevalence and diagnostic accuracy.

We prospectively examined 128 patients with acute first-ever stroke to determine the prevalence of swallowing disorders, the diagnostic accuracy of our clinical assessment of swallowing function compared with videofluoroscopy, and interobserver agreement for the clinical and videofluoroscopic diagnosis of swallowing disorders and aspiration. We found clinical and videofluoroscopic evidence of a swallowing disorder in 51% [95% confidence interval (CI) 42-60%] and 64% (95% CI 55-72%) of patients, respectively, and aspiration in 49% (95% CI 40-58%) and 22% (95% CI 15-29%) of patients, respectively. The optimal clinical criteria for detecting videofluoroscopic evidence of a swallowing disorder and aspiration were any clinical evidence of a swallowing disorder (sensitivity 73%, 95% CI 62-82%; specificity 89%, 95% CI 76-96%), and any clinical evidence of aspiration (sensitivity 93%, 95% CI 76-99%; specificity 63%, 95% CI 53-72%). The interobserver agreement between two speech pathologists for the clinical diagnosis of a swallowing disorder (kappa: 0.82 +/- 0.09) and aspiration (kappa: 0.75 +/- 0.09) was good, and between a speech pathologist and radiologist for the videofluoroscopic diagnosis of a swallowing disorder (kappa: 0.75 +/- 0.09) and aspiration (kappa: 0.41 +/- 0.09), it was good and fair, respectively. Although clinical bedside examination underestimates the frequency of swallowing abnormalities and overestimates the frequency of aspiration compared with videofluoroscopy, it may still offer valuable information for the diagnosis of swallowing impairment. Long-term follow-up studies are required to determine the independent functional significance of the findings of the bedside and videofluoroscopic examinations in predicting the occurrence of important outcome events such as aspiration pneumonia.

Acute Disease↗