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Biomedical subjects

D Arens

Publications and source records attributed to D Arens.

6 recordsLinked to original sources

Bone age in 116 untreated patients with Turner's syndrome rated by a computer-assisted method (CASAS).

Bone age maturation in 116 untreated patients with Turner's syndrome was evaluated in a cross-sectional and longitudinal analysis. A total of 265 radiographs were rated using the TW2-RUS method on the computer-assisted skeletal age score (CASAS) system. Bone age was found to be retarded from the chronological age of 3 to 6y. Between the ages of 7 and 12 y bone age almost equalled chronological age and progressed normally at a rate of 1 y y(-1). Bone maturation slowed down thereafter and epiphyseal closure was not reached before the age of 17 y. Reference data are presented on bone age and a bone age maturation curve for untreated patients with Turner's syndrome to be used in clinical practice. In the assessment of bone age and bone age velocity in Turner's syndrome the CASAS system produced reliable and valid results. The absolute difference between repeated bone age ratings was 0.26 "y" (median) with a range of 0.00-0.56 "y". Future studies evaluating the effect of growth-promoting treatment in Turner's syndrome should use a computerized method for the determination of bone age.

Adolescent

The isolated perfused bovine udder as an in vitro model of percutaneous drug absorption. Skin viability and percutaneous absorption of dexamethasone, benzoyl peroxide, and etofenamate.

Using udders from slaughtered cows as a new in vitro model of percutaneous drug absorption, the tissue viability and the percutaneous absorption of dexamethasone, benzoyl peroxide, and etofenamate were studied. The organ was perfused with gassed tyrode solution for up to 6 hr. As shown by measurement of glucose consumption, lactate production, lactate dehydrogenase activity, and pH in the perfusate, the tissue was viable over a 6-hr period. This was confirmed by a histological examination. Determination of the udder skin-fold thickness demonstrated that no edema developed within the perfusion period. A maximum skin penetration of dexamethasone was found after administration of dexamethasone dissolved in acetone with dimethyl sulfoxide, followed by ointment with salicylic acid, ointment without salicylic acid, and acetone solution. Experiments with benzoyl peroxide and etofenamate demonstrated that the perfused udder skin was capable of metabolizing drugs in vitro. In conclusion, the isolated perfused bovine udder is a new in vitro model, which maintains bovine udder skin with an isolated vasculature in a viable state. Using this in vitro model, we note it is possible to compare the dermal penetration, metabolism, and absorption of substances after topical administration of different drug formulations.

Animals

The role of bleaching in esthetics.

Bleaching discolored teeth must be considered a viable treatment modality. Although it does not offer the predictability of many cosmetic options, its simplicity and economics demands attention. Combining bleaching with selected bonding and contouring can return a smile to the not-so affluent, conservative, or apprehensive patient who does not wish to face tooth reduction and full coverage.

Esthetics, Dental