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Biomedical subjects

M Humphreys

Publications and source records attributed to M Humphreys.

43 records · Page 3Linked to original sources
PubMed1982

Impaired metabolism of methylphenobarbital after a combined drug overdose: treatment by resin hemoperfusion.

A 38-yr-old woman who by history ingested 13 g methylphenobarbital, alcohol, and 6 g acetaminophen became comatose slowly over 4 d. Acute hepatic injury appeared to impair the oxidative N-demethylation of methylphenobarbital to its product, phenobarbital. On the eighth day after ingestion she was treated because of protracted coma with Amberlite XAD-4 resin hemoperfusion. Hemoperfusion, which removed 0.83 g methylphenobarbital and 2.10 g phenobarbital, led to transient clinical improvement. When supportive patient management fails to produce a satisfactory clinical course in a methylphenobarbital-intoxicated patient, hemoperfusion could be a useful adjunct to therapy.

Acetaminophen↗
PubMed1980

Resin hemoperfusion in ethychlorvynol overdose.

An 18-yr-old male with a severe ethchlorvynol (ECV) overdose was treated with Amberlite XAD-4 resin hemoperfusion. Plasma ECV concentration declined 33% during a 3.5-hr hemoperfusion, but rebounded substantially, peaking 6 hr later. It was estimated that 16% of ECV in the body was removed. Following hemoperfusion, plasma ECV concentrations declined linearly at a rate of 13 mg/1/day. Hemoperfusion clearance was estimated by both the traditional method, using extraction ratios across the column and column blood flow (Cl = 270 ml/min), and an alternative method, using blood concentrations during hemoperfusion and recovery of drug from the resin (Cl = 184 ml/min). The latter may provide a better estimate of hemoperfusion clearance because it is not subject to error (which can be substantial) in measurement of column blood flow. The resin completely extracted ECV from plasma, resulting in a rate of elimination 10 times that expected from endogenous processes. To aid in kinetic analysis, blood:plasma partition and protein binding of ECV in 3 normal subjects were also examined. Blood:plasma ratio averaged 0.88 +/- 0.04 and fraction free in plasma, 0.38 +/- 0.02; neither changed as a function of blood concentration between 27 and 108 mg/1. Our data indicate that removal of ECV from the overdosed patient by hemoperfusion is limited by extensive distribution in and slow redistribution from body tissues, but because of the extremely slow rate of removal by the body and the severe nature of the ECV overdose, Amberlite XAD-4 hemoperfusion may be clinically useful.

Adolescent↗
PubMed1979

Context change and the role of meaning in word recognition.

Two experiments were conducted in which the central variable was the addition of verbal context on the test which was not present during study. Neither study showed context to be a relevant variable. Because verbal context effects (when they do occur) are presumed to result from a change of meaning, the broader role of word meaning in recognition was examined. Studies in which homographs were used to produce a change in meaning were reviewed with the conclusion that when appropriate controls are used the effects are too small to support meaning as a major factor underlying recognition. An experiment using homographs verified the general conclusion from previous studies. A review of studies was then undertaken to determine the influence of synonym distractors on recognition scores. If word meaning is critical in word recognition, the use of synonyms of study words as new words on the recognition test should produce large decrements. The evidence available did not support this expectation, and an experiment using both within-subject and between-subject comparisons showed at best only small effects. The general conclusion was that theories of recognition in which word meaning plays a dominant role cannot be supported. It is likely that word meaning is encoded during study of lists of words but is infrequently used in making recognition decisions.

Form Perception↗
PubMedDate not supplied

Are the nutritional recommendations for insulin-dependent diabetic patients being achieved?

Dietary intake was assessed, using a 3-day recorded food diary, in 122 patients with insulin-dependent diabetes. Subjects were selected randomly from patients attending a diabetic clinic and stratified for age, sex, and duration of diabetes. The findings were compared to the dietary recommendations of the European Association for the Study of Diabetes (EASD) and to the findings in a recent Irish National Nutrition Survey. The average daily protein intake among diabetic patients was 18% of the total calories, significantly higher than recommended by EASD and significantly higher than in the age-matched general population. Dietary fat intake was on average 37% of total calorie intake, again significantly higher than recommended and greater than in the general population among older patients. Saturated fat intake was higher than recommended and polyunsaturated fat intake was low. The average carbohydrate intake was 42% of total calories, significantly lower than recommended and similar to that in the general population. Sugar intake was lower and starch intake was higher among patients than in the general population, however. Fibre intake was also lower than recommended, but was higher than in the general population. We conclude that the present dietary targets for diabetic patients are not being fully achieved.

Adolescent↗