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Biomedical subjects

D Matthew

Publications and source records attributed to D Matthew.

13 recordsLinked to original sources

Electrolyte disturbance with omeprazole therapy.

Omeprazole is an antagonist to the H+K+ ATPase of the gastric parietal cell. We report a case of severe electrolyte disturbance in a 5-year-old child treated with omeprazole associated with excessive urinary sodium loss, that responded completely to omeprazole withdrawal.

Child, Preschool

Disposition of azole antifungal agents. I. Nonlinearities in ketoconazole clearance and binding in rat liver.

The disposition of ketoconazole was characterized in the rat over a wide dose/concentration range. Bolus dose (0.03-10 mg/kg) studies indicate that plasma concentration-time profiles for ketoconazole are not superimposable when dose normalized because of nonlinearities occurring in both volume of distribution and clearance. The volume of distribution decreases from 3 to less than 1 L/kg, while the plasma clearance decreases 10-fold from 25 mL/min/kg as the dose is escalated. From these results, infusion rates were calculated to maintain the plasma concentrations achieved with particular bolus doses. The curvilinear relationship between steady-state plasma concentration (0.015-8.3 mg/L) and ketoconazole infusion rate (0.021-2.45 mg/hr/kg) was analyzed in terms of Michaelis-Menten kinetics. A Vmax of 3.2 mg/hr/kg and Km of 2.1 mg/L were obtained by nonlinear regression analysis. At the end of the ketoconazole infusion, liver, adrenals and kidneys were removed and assayed for ketoconazole. Tissue-to-plasma partition coefficients for the liver and adrenals showed a marked dependence upon steady-state plasma concentration. Both parameters (liver, 22; and adrenals, 53) showed a decrease of approximately 10-fold as the plasma concentrations were increased. In contrast, the kidney:plasma partition coefficient (1.8), blood:plasma concentration ratio (0.6), and plasma binding (96%) of ketoconazole did not show a concentration dependence over the range studied. It is concluded that the liver is an important determinant of ketoconazole's volume of distribution and that saturation of this process accounts largely for the reduction in volume of distribution with increasing dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Comparison of two kits for measuring ferritin in blood.

Ferritin concentrations in blood are a good indicator of iron stores and can be measured in plasma or serum with commercial kits. We have measured plasma ferritin content in infants ranging from 3 to 15 months of age. During the first three years of a four-year study, plasma samples drawn from these infants were shipped to Abbott Laboratories in Chicago and assayed using the Ferrizyme immunoassay technique (Abbott Laboratories, Chicago, Illinois). For the last year of the study, we analyzed the remaining samples in St. John's using the radioimmunoassay GammaDab125 I Kit (Baxter Travenol Diagnostics, Inc., Cambridge, Massachusetts). Both kit manufacturers report inter- and intra-assay variability of < or = 5%. Results for samples analyzed by the second method were higher than earlier results from infants of the same age with the same intakes of iron; thus, we decided to analyze subsequent samples with both kits.

Ferritins

Severe tracheobronchomalacia associated with laryngeal cleft.

We report 3 cases of severe tracheobronchomalacia associated with laryngeal cleft. Each of these children had a major cleft, type 3 in Evans' classification. Separately each of these conditions are difficult to treat, in combination these major airway anomalies caused management problems of great complexity. We describe the presentation of these cases, the diagnosis of the lesions and the management paths we followed. We discuss the pathology of the conditions and the diagnostic options which are available for defining the extent of responsibility of each component to the overall clinical picture. We discuss the therapeutic options available and describe our own management regime.

Bronchial Diseases

Childhood asthma. A controlled trial of family psychotherapy.

In an attempt to evaluate the effectiveness of family psychotherapy as an adjunct conventional treatment in childhood asthma, children with moderate to severe asthma were randomly allocated to a control group or to an experimental group; the latter group received 6 hours of family treatment during a 4-month period, and both groups had standard medical treatment. While there was no significant difference between the two groups on three parameters, the experimental group were significantly better in day-wheeze score and thoracic gas volume. These results suggest that family treatment in selected cases may have a place in the overall management of childhood asthma, and that more research with larger numbers of children is necessary.

Adolescent