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Biomedical subjects

J D Mason

Publications and source records attributed to J D Mason.

8 recordsLinked to original sources
PubMed1992

Foetal warfarin syndrome--a complex airway problem. Case report and review of the literature.

Premature cartilaginous calcification and nasal hypoplasia following first trimester exposure to warfarin are known as the Foetal Warfarin Syndrome (FWS). There are over 40 cases reported in the literature, many of which describe breathing and feeding difficulties in the first few months of life. We report a case where a child had had difficulties breathing and feeding in the first months of life. These had been attributed to nasal hypoplasia. After proper ENT assessment the child benefitted from adenoidectomy. ENT surgeons should be aware of the syndrome as more women of child bearing age are taking warfarin following cardiac surgery and treatment of thromboembolic disease. ENT surgeons may be asked to review these children who often present with airway and feeding problems which have been attributed to nasal hypoplasia.

Calcinosis↗
PubMed1990

Small-sample reproducibility estimates: an example using rebreathing measurements.

We developed a statistical technique to estimate the reproducibility of a parameter from a population in which only two repeated measurements can be made in a single individual. The following data were analyzed: acetylene cardiac output (Qc), lung tissue volume (Vti), and carbon monoxide diffusing capacity (DLCO) measured by rebreathing techniques in a population of 86 healthy subjects (51 men and 35 women). Each subject was measured twice with a computerized rebreathing system using a test gas of 10% He-0.3% C18O-0.7% C2H2-25% O2-balance N2 while sitting at rest. The estimated coefficients of variation for repeated measurements were 6.8, 10.3, and 5.7% for Qc, Vti, and DLCO, respectively. Chebyshev's inequality was used to estimate the imprecision for a single measurement of these parameters and for averages of two or more repeated values. A single measurement of Qc would be within 14.2% of a "true" mean 90% of the time, whereas an average of three consecutive measurements would be within 8.2% of the true mean 90% of the time. Single measurements of Vti and DLCO were found to be within 21.7 and 12.0%, respectively, of the true mean 90% of the time. When three consecutive measurements are averaged, Vti is within 12.6% and DLCO is within 6.9% of the true mean 90% of the time. We conclude that 1) rebreathing Qc is as reproducible as other measurements of cardiac output, 2) rebreathing measurements of DLCO are as reproducible as those made by the single-breath technique, and 3) an average of two to three measurements of Vti should be made to obtain values with a reasonable degree of precision.

Acetylene↗
PubMed1989

The usefulness of serum electrolytes in the evaluation of acute adult gastroenteritis.

Acute gastrointestinal disorders are among the most common problems encountered by the emergency physician. Serum electrolytes are commonly ordered in the evaluation of patients with gastroenteritis. We retrospectively reviewed the charts of all 281 patients with a discharge diagnosis of acute gastroenteritis seen in our emergency department during a recent six-month period. Electrolytes were ordered on 207 of these patients, and the time spent in the ED was three to four times longer for patients on whom electrolytes were ordered. Of these 207, 24 (11%) had electrolyte abnormalities, but only two (1%) had clinically significant electrolyte abnormalities, which were defined as values that affected patient treatment or disposition. On presentation, 56 patients (27%) had orthostatic vital sign changes (defined as a pulse increase of 30 or more on standing). Five (10%) had electrolyte abnormalities. None of the abnormalities were clinically significant. Eleven patients (5%) were hospitalized. One patient had electrolyte abnormalities that were not the cause of hospitalization. No patients with uncomplicated gastroenteritis alone had clinically significant electrolyte abnormalities. We conclude that there is no justification for the routine ordering of serum electrolytes on the adult patient with acute gastroenteritis.

Acute Disease↗
PubMed1989

Psychobiological effects of carbohydrates.

The authors studied whether the fatiguing effects of eating lunch are greater for carbohydrate-rich meals than for other meals, and related the time course of behavioral change to plasma glucose, insulin, and amino acids. On different occasions, in counterbalanced order, normal women (N = 7) fasted overnight, ate a standard breakfast, and at lunch either continued to fast or ate a high-carbohydrate, low-protein meal; a hedonically similar meal containing both carbohydrate and protein; or a high-protein, low-carbohydrate meal. Meals were isocaloric and equated for fat content. Only the carbohydrate meal significantly increased fatigue, which could not be attributed to hypoglycemia because plasma glucose remained elevated. Fatigue began approximately, when the carbohydrate meal elevated the plasma tryptophan ratio but ended even though the ratio remained elevated. Fatigue after a high-carbohydrate lunch could not be explained by reactive hypoglycemia or sweet taste, and could partially be explained by the hypothesis that fatigue parallels an elevation of the tryptophan ratio.

Adolescent↗