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Biomedical subjects

A Lipson

Publications and source records attributed to A Lipson.

9 recordsLinked to original sources

Irrational reactions to negative outcomes: evidence for two conceptual systems.

According to cognitive-experiential self-theory (CEST), individuals have 2 systems for processing information, a rational system and an experiential system. Research conducted under norm theory (NT) has provided impressive evidence of an if only (IO) effect associated with postoutcome processing of aversive events that are highly consistent with formulations in CEST. Two studies involving vignettes adapted from NT were conducted that tested 4 hypotheses and corollaries derived from CEST. It was demonstrated, in support of hypotheses, that the IO effect can be obtained with ratings of one's own and of a protagonist's specific behaviors, as well as with ratings of a protagonist's diffuse emotions (the usual procedure); that a rational orientation decreases the IO effect; that increasing the intensity of outcomes increases it; and that priming the experiential system reduces people's ability to subsequently think rationally. The theoretical and research implications of these findings are discussed.

Adult

Intestinal bile salts in cystic fibrosis: studies in the patient and experimental animal.

The quantitative and qualitative distribution of bile salts in the duodenal juice of 13 patients with cystic fibrosis (CF) was studied after a test meal. The effects of triolein (TO), bovine serum albumin (BSA), and ricinoleic acid (RA) on the absorption of taurocholate (TCA) in the distal ileum of the rat in vivo was also studied. The mean (and ranges) of total bile salt concentrations, glycine: taurine conjugate ratios, and percentage of dihydroxy bile salts in the patients with CF and pancreatic insufficiency were 3.5 (1.3--6.6) mmol/l, 8.6 (greater than 10-3.1), and 37 (10--60) compared with control values of 7.4 (3.0--16.0) mmol/l, 3.0 (1.3--4.5), and 61 (52--70) respectively. The differences between the control and CF values were statistically significant (P less than 0.01--P less than 0.001). Three of the 13 CF patients had total bile salt concentrations less than 2 mmol/l, 8 had much higher glycine: taurine ratios, and 8 had a reduced percentage of dihydroxy bile salts. In 2 patients with normal pancreatic enzyme activities, duodenal bile salts were both quantitatively and qualitatively normal. TO (10 and 30 mmol/l), BSA (3%), and RA (5 mmol/l) had no inhibitory effect on the ileal absorption of TCA. These results show pronounced abnormalities of duodenal juice bile salts in CF with pancreatic insufficiency consistent with a broken enterohepatic circulation (EHC); such abnormalities may contribute to defective lipid absorption in CF. The data in the experimental animal do not support the suggestion that unhydrolysed dietary substrates play a role in the pathophysiology of the broken EHC.

Adolescent

A study of age-dependent changes in thyroid function tests in adults.

Total serum thyroxine (T4), triiodothyronine (T3), T3 resin uptake (T3U), thyrotrophin (TSH), and reverse T3 (rT3) were measured in 209 healthy adults 20--89 yr old. Mean T4 values for men were stable throughout life, but in females under age 60, T4 values were significantly higher than in older women. Values for T3U in males were significantly higher than in females throughout all decades, although females had a significant increase in T3U after age 60. TSH values increased significantly in females over age 60. Throughout all decades, males had stable TSH levels that were slightly higher than the female results before age 60 and lower thereafter. Mean serum T3 declined similarly for both sexes with increasing age, although not to the extent previously reported. Men had significantly higher mean rT3 values over all decades than females, although female rT3 levels decreased after age 50 whereas males maintained stable values. The physiologic reasons for these findings may be due to sex-related changes in binding proteins and alterations in metabolic clearance rates, production, and degradation of these hormones with increasing age.

Adult

Alterations in human high-density lipoproteins, with or without increased plasma-cholesterol, induced by diets high in cholesterol.

High-density lipoproteins (d=1.095--1.21) (H.D.L.( were isolated from six healthy men and women who added 4 to 6 eggs per day to their diet for 4 weeks and from five individuals who gradually increased their egg consumption to 3 per day over an 18-week period. Pre-diet and post-diet H.D.L.-binding activities for the cell-surface receptors of fibroblasts were compared by determining the quantity of 125I-labelled low-density lipoprotein which was competitively displaced by H.D.L. in binding, internalisation, and degradation assays. Irrespective of whether plasmacholesterol changed during the course of the diet, the binding activity of the post-diet H.D.L. was enhanced 2.6-fold to 4-fold compared with pre-diet activity. Furthermore, the increased binding activity in the H.D.L. could be accounted for by a minor, but potent, H.D.L. subfraction precipitated by heparin/manganese. Both binding activity and heparin precipitability appeared to correlate with an increase in arginine-rich apoprotein (apo-E) in the active H.D.L. subfraction. These data show that consumption of large numbers of eggs, whether or not it leads to an increase in plasma-cholesterol, does alter the properties of human H.D.L.

Adult

Treatment of pneumocystis carinii pneumonia in children.

Eighteen children with pneumocystis carinii pneumonia diagnosed over a period of 16 years at a children's hospital are reviewed. All had an underlying disease, either congenital immunodeficiency or a malignancy. 15 patients were treated, 10 with pentamidine isethionate alone, 2 with both pentamidine and co-trimoxazole, and 3 with co-trimoxazole alone. 12 of the treated group recovered and the 3 untreated patients died. The 3 deaths after treatment occurred in children receiving pentamidine alone, and in whom secondary factors contributed. The side effects of treatment with pentamidine were high, and included local reactions, hypoglycaemia, and uraemia. However, our results confirm that pentamidine is an effective treatment for pneumocystis carinii pneumonia in childhood. Co-trimoxazole may be an effective and relatively nontoxic alternative treatment.

Amidines

Porcine pancreatin as a source of salmonella infection in children with cystic fibrosis.

Contamination of a powdered preparation of pancreatin with Salmonella schwarzengrund and S. eimsbuettel resulted in the infection of at least 31% of one group of paediatric patients with cystic fibrosis. The pancreatin contained very small numbers of Salmonellae, the infecting dose in at least one child being less than 44 organisms. More stringent bacteriological standards are needed for pharmaceuticals and foods used by paediatric patients.

Child, Preschool