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Biomedical subjects

B Maas

Publications and source records attributed to B Maas.

At least 19 recordsLinked to original sources

A comparative bioavailability study of carbamazepine tablets and a chewable tablet formulation.

Differences in product formulations have been shown to affect the therapeutic response by altering the relative bioavailability and pharmacokinetics of a drug. The relative bioavailability and pharmacokinetics of carbamazepine tablets (CBZ) and a chewable tablet formulation were evaluated in 10 normal healthy subjects (five men and five women). The study utilized a randomized, crossover design with a 4-week washout period between doses. Blood samples were collected at 0, 1, 2, 3, 4, 6, 8, 10, 14, 24, 30, 36, and 48 h following a 200-mg dose. Plasma samples were assayed by fluorescence polarization immunoassay. Ke, Cmax, Tmax, area under the curve (AUC), and relative bioavailability were estimated using traditional pharmacokinetic methods and compared by paired t test. A statistically significant higher Cmax (3.81 +/- 81 vs. 4.64 +/- .80 mg/L) was observed with the chewable tablet formulation but was not thought to be clinically relevant. No significant differences between formulations for Ke (0.022 +/- 0.007 vs. 0.025 +/- 0.008 h-1 h), Tmax (7.49 +/- 2.69 vs. 6.04 +/- 2.7 h), AUC 48 h (119 +/- 22 vs. 133 +/- 13 mg/h/L), or AUCO--infinity ( 221 +/- 40 vs. 203 +/- 41 mg/h/L) were noted. Absorption was variable for both preparations. The relative bioavailability using the tablet as the standard formulation was (0.92 +/- 0.22). Transient, mild side effects were noted in three subjects with the chewable tablet alone, and one subject experienced side effects with both formulations. It was concluded that CBZ tablets and chewable tablets may be used interchangeably; however, considerable intra- and intersubject variability exists, and the need for patient monitoring is emphasized.

Adult

[Remission behavior following low-dose 13-cis-retinoic acid in papulopustular acne].

64 patients suffering from severe papulopustular acne previously resistant to therapy were treated with 13-cis retinoic acid (isotretinoin) at a dosage of 0.05, 0.1, or 0.2 mg/kg body weight for 20 weeks. After treatment, we performed follow-up examinations for 12 months concerning remission and side effects. After six months, more than half of the patients were free of relapses, even those treated with low doses, although there was a trend in favor of the 0.2 mg/kg body weight dose. According to lesion counts, the therapeutic effect of isotretinoin was even better after discontinuation of the drug. Mucocutaneous side effects disappeared within four to six weeks. In severe papulopustular acne, previously showing inadequate response to therapy, at least 0.2 mg/kg body weight isotretinoin should be given to ensure a good therapeutic result. These findings correspond with those observed in the initial reduction of lesions.

Acne Vulgaris

[Allergic contact dermatitis due to Asteraceae (Compositae). Cross reaction with Liatris spicata].

Case reports of 2 florists suffering from contact dermatitis to Asteraceae, especially to Chrysanthema are described. In addition, in both patients allergic patch-test reactions to another Asteraceae species (Liatris spicata) could be demonstrated. This Asteraceae species is a native flower (Blazing Star) in the USA, but in Germany we find the flower in shops, and sometimes in parks and gardens. Genus Liatris contains about 30 species. Numerous sesquiterpene lactons are isolated from Liatris species which are probably cross reactive with sesquiterpene lactons from Asteraceae native to Europe.

Agriculture

[13-cis-retinoic acid. Low dosage oral use in acne papulopustulosa. Results of a multicenter study].

Successful treatment of acne conglobata with 13-cis-retinoic acid (isotretinoin, Ro 4-3780) has already been reported in this journal [25, 36]. The aim of the present study was to treat severe forms of papulopustular acne, unresponsive to conventional therapy, with low doses of 13-cis-retinoic acid to obtain good results with few side effects. A total of 191 patients from 14 departments of dermatology in the Federal Republic of Germany received 13-cis-retinoic acid under open randomized conditions in parallel dose groups of 0.05, 0.1, and 0.2 mg/kg body weight for 20 weeks in order to establish efficacy and tolerance. All inflammatory and non-inflammatory skin lesions were counted. The intensity of seborrhea was graded by using a scale. Adverse effects as well as laboratory values were registered. After 20 weeks of treatment a 79% (0.05 mg), 80% (0.1 mg), and 84% (0.2 mg) decrease in the number of inflammatory skin lesions was seen. Fourteen patients in the lowest dose group were considered to be dropouts. The decrease in non-inflammatory skin lesions was less marked and amounted to between 49% and 69%. A significant reduction of seborrhea could be observed in all patients. The main side effect was dryness of the skin and mucous membranes, which was, however, of low intensity. The elevation of triglyceride and cholesterol levels reported with higher doses of 13-cis-acid, especially in patients with high-risk factors, were not encountered in this study.

Acne Vulgaris

[Hypacusis in acquired hypothyroidism (author's transl)].

We examined 56 patients with latent or clinical hypothyroidism and a control group of 18 patients with acute hypothyroidism. We were especially interested in the localization and extent of hearing abnormalities. 45% of the patients with chronic hypothyroidism showed a hearing loss. 2 of these patients had a pure conductive loss, 7 a combined hearing loss and 16 a sensorineural hearing loss. We demonstrated hair cell damage in 13 of the patients with chronic hypothyroidism. This loss was mild to moderate in over 90% of the cases. Although several patients had basilar-cochlear hearing losses, no characteristic audiograms could be found. 50% of the patients showed a small improvement in hearing after thyroid substitution therapy. The results of our examinations are discussed in detail.

Adolescent

[Hypacusis in acquired hypothyroidism (author's transl)].

We examined 56 patients with latent or clinically manifest hypothyroidism and 18 patients with acute athyreosis as a control group. We were especially interested in the localization and extent of hearing abnormalities. 45% of the patients with chronic hypothyroidism showed a hearing loss. Of these, two patients had a pure conductive loss, seven a combined hearing loss and 16 a sensori-neural hearing loss. We demonstrated hair cell damage in 13 of the patients with chronic hypothyroidism. The hearing loss was mild to moderate in over 90% of the cases. Although several patients had a basocochlear hearing loss, no characteristic audiogram was found. There was a correlation between the conductive loss and the severity of the hypothyroidism. 50% of the patients showed a significant improvement in hearing after substitution therapy. The results of our examinations are discussed in detail.

Adolescent