Solitary morphea profunda in a 5-year-old girl: case report and review of the literature.

A 5-year-old girl had a solitary sclerotic plaque on the back of recent onset. The histopathologic features were consistent with morphea profunda. Thickening and homogenization of collagen bundles were demonstrated in the dermis and subcutaneous tissues, admixed with a prominent lymphocytic and plasma cell inflammatory infiltrate. Solitary morphea profunda is a variant of localized scleroderma that has not been reported previously in childhood. Cases described in the literature as nodular or keloid morphea may represent a similar entity.

Glipizide pharmacokinetics: effects of age, diabetes, and multiple dosing.

Aging and disease may contribute to alterations in drug pharmacokinetics. The purpose of this study was to determine the effects of aging, the presence of NIDDM, and multiple dosing on the pharmacokinetics of glipizide, an oral hypoglycemic drug. Ten healthy young men (under age 25), ten healthy older men (over age 65) and 15 older diabetic men ingested a single 5 mg tablet of glipizide after an overnight fast. Blood samples for measurement of serum glipizide were obtained over the next 24 hours. The study was repeated in the diabetics after 2 weeks of daily therapy. The mean values for Tmax (range 2.0-2.5 hours), Cmax (385-465 micrograms/l), and t1/2 (4.0-4.2 hours) were not significantly different in the three populations after single doses of glipizide. Several subjects in each population had slow absorption, with peak concentrations delayed for up to 12 hours. Only one elderly diabetic subject had evidence of drug accumulation at steady state. AUC, Cl, Vss and V area were not significantly different in the three populations or at steady state, but there was a trend for AUC to be smaller and each of the other parameters to be increased in the older diabetics. The young subjects had a significantly higher fp (0.83%) than either of the two elderly groups (0.55-0.64%), but Cl int did not differ between groups. Age, diabetes, and multiple dosing appear to have little effect on the pharmacokinetics of glipizide and should have little influence on the clinical response to this drug.

Glipizide pharmacokinetics in young and elderly volunteers.

The effects of aging on the pharmacokinetics of glipizide were studied. Ten healthy young men (24.9 +/- 1.9 years of age) and 10 healthy older men (74.4 +/- 7.9 years of age) each ingested a single 5-mg tablet of glipizide after an overnight fast. Blood samples were obtained immediately before drug ingestion and at 10, 20, 30, 45, 60, 90, and 120 minutes and at 3, 4, 6, 8, 10, 12, and 24 hours after drug ingestion. Serum samples were assayed for glipizide content by a modified high-pressure liquid chromatographic method. Clearance, volume of distribution at steady state, and half-life were estimated from the serum concentration-time curve data. Area under the concentration-time curve and area under the moments curve were calculated using the trapezoidal rule. The mean values for young and older subjects for time to peak concentration (2.1 versus 2.5 hours), peak concentrations (465 versus 399 micrograms/mL), elimination half-life (4.2 versus 4.0 hours), clearance (38.8 versus 38.1 mL/min), and distribution volume at steady state (12.5 versus 14.3 L) were not significant. However, two older individuals had a markedly prolonged time to peak concentration (six to eight hours). For 8 of the 20 subjects a more prolonged terminal half-life may have existed. Further study is required to determine whether significant pharmacokinetic differences between young and elderly subjects appear with multiple dosing of glipizide.

The response of the kidney of the freshwater rainbow trout to true metabolic acidosis.

Infusion of lactic acid into the bloodstream of trout produced a short-lived depression of blood pH and a long-lasting elevation of blood lactate. The lactate injected was distributed in a volume of 198 ml/kg. Renal excretion of lactate anion and total acid increased by approximately equal amounts during the period of high blood lactate levels, but total renal loss over 72 h accounted for only 2% of the lactate load and 6% of the proton load. Comparable differences in the time courses of blood lactate and pH changes occurred when lactacidosis was induced endogenously by normocapnic hypoxia. The immediate response of the kidney was similar to that with lactic acid infusion, but there was a long-lasting (12-72 + h) elevation of urinary acid efflux that was not associated with lactate excretion. Following hypoxia, renal excretion over 72 h accounted for 1% of the estimated lactate load and 12-25% of the proton load. A renal lactate threshold of 4-10 muequiv/ml prevents significant urinary lactate excretion. The response of the trout kidney to true metabolic acidosis is similar to that of the mammalian kidney.