Biomedical subjects

R Schwarzenbach

Publications and source records attributed to R Schwarzenbach.

4 recordsLinked to original sources

PubMed2000

[Disseminated small-node cutaneous sarcoidosis].

HISTORY AND ADMISSION FINDINGS: For 6 months before admission an 83-year-old woman had experienced itching from papules on her back. Despite local and systemic corticosteroid treatment the lesions had spread further over the back and also began to involve the proximal limbs. On examination the patient was noted to be fit for her age. At the described sites there were scattered red-brown maculopapular lesions, pin-head sized, some circumscribed, others confluent. Diascopy demonstrated them to be greyish yellow. INVESTIGATIONS: Erythrocyte sedimentation rate was 15/42 mm, serum concentrations of angiotensin converting enzyme (ACE) and calcium were within normal limits. The Tine test was negative. Skin biopsy revealed a granulomatous epithelioid cell inflammation in the corium without central necrosis. She had diabetic retinopathy, a complication of type II diabetes mellitus for many years, and hepatic steatosis. TREATMENT AND COURSE: The results of the clinical and histological findings and exclusion of systemic involvement established the diagnosis of disseminated small node cutaneous sarcoidosis. Under clofazimine (Lampren), at an initial dosage of 3 x 100 mg daily by mouth, gradually reduced over 4 months, the cutaneous lesions healed completely and lastingly. CONCLUSION: This form of sarcoidosis has a good prognosis. Clofazimine, being efficacious and well tolerated, provides a good therapeutic alternative.

Aged↗

PubMed1999

The systemic exposure to the polycyclic musks, AHTN and HHCB, under conditions of use as fragrance ingredients: evidence of lack of complete absorption from a skin reservoir.

7-Acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) and 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexa-methylcyclopenta-gamma-2-be nzopyran (HHCB) are two large volume fragrance ingredients widely used in consumer products. As part of the risk evaluation, the systemic exposures to these materials was determined in rats under occlusion and in humans under simulated conditions of exposure. Ring 14C-labeled AHTN or HHCB were applied dermally in alcoholic solutions to rats at doses of 4.5 mg/kg and occluded for 6 h. Urine, feces and air were collected for up to 120 h and analyzed for radioactivity. Pairs of rats were sacrificed periodically for analysis of tissues and organs. The total amount absorbed was approximately 19% for AHTN and 14% for HHCB. In both cases, significant amounts diffused into the skin, most of which was further absorbed but a significant amount of which was lost to surface dressing by reverse diffusion and/or desquamation. Ring 14C-labeled AHTN or HHCB were applied in alcoholic solutions without occlusion to three male volunteers at concentrations approximating that which might be encountered in a typical cologne type product. After a 6-h period, all material was removed from the surface of the skin. Blood, feces and urine were collected over a 5-day period. For both materials, levels in blood and plasma were below limits of detection at all times. Based on excretion, primarily in the urine, the total absorbed dose was approximately 1 and 0.1% for AHTN and HHCB, respectively. However, over the 5-day period, 14.5% of AHTN and 19.5% of HHCB was recovered from the skin in dressings over the site of application indicating that a 'reservoir' had formed in the skin but the material in the reservoir was lost, by desquamation and/or by reverse absorption, and not available systemically. A mean of 24% (AHTN) and 22% (HHCB) was shown to evaporate under the conditions of exposure.

Animals↗

PubMed1998

[Pseudopelade Brocq--possible sequela of stage III borrelia infection?].

The differential diagnosis of cicatricial alopecia includes a wide variety of diseases. A 60-years-old woman was admitted to the hospital because of an unsuccessfully treated, progressive pseudopelede of Brocq. Further examination revealed an borreliosis (Stage III). After 3 weeks of treatment with intravenous Cefotaxime (Claforan), follow-up examination one year later show an complete arrest of the alopecia. This first description of cicatricial alopecia to be causally related to borreliosis Stage III extends the differential diagnosis of pseudopelede of Brocq and offers a curative therapy.

Alopecia↗

PubMedDate not supplied

Percutaneous absorption of sunscreens in vitro: interspecies comparison, skin models and reproducibility aspects.

Appropriate evaluation of sunscreens is required to provide better knowledge of their safety and efficacy. One of the most important elements of this evaluation is the assessment of percutaneous absorption. In vitro methods are largely used for such assessments, and the accuracy of the measurements generated with these methods depends on the use of a proper methodology. This study was designed to evaluate an in vitro protocol for investigating the percutaneous absorption of two sunscreens under standardized experimental conditions. Octyl methoxycinnamate and benzophenone 4 were each incorporated in a typical oil-in-water emulsion and tested separately. Salicylic acid was tested as a reference compound. In vitro percutaneous absorption was evaluated using two species, the pig and human, and two models, full-thickness and split-thickness skin. The reproducibility of study results was evaluated by comparing the data generated by two industrial laboratories, L'Oréal and Hoffmann-La Roche. The correlation of quantitative data between pig skin and human skin was very good, and the split-thickness skin model seemed to be more appropriate for measuring the absorption of sunscreens. Results obtained for salicylic acid demonstrated the relevance of the protocol in terms of prediction of in vivo percutaneous absorption. Finally, the comparison of pig skin data between the two laboratories demonstrated a good correlation and underlined the need for a standardized in vitro procedure.

Animals↗