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Biomedical subjects

M R Albert

Publications and source records attributed to M R Albert.

12 recordsLinked to original sources
PubMed2001

Murine epidermal label-retaining cells isolated by flow cytometry do not express the stem cell markers CD34, Sca-1, or Flk-1.

Keratinocyte stem cells are present in the murine epidermis, based on both in vitro and in vivo evidence, and better characterization of these cells remains an active goal. Because keratinocyte stem cells are believed to cycle slowly, a good method for identification is based on their ability to retain nucleoside analog, such as bromodeoxyuridine. Adult stem cells have been identified in other tissues, including hematopoietic, neural, and skeletal muscle, and stem cell surface markers have been characterized. We wanted to determine if cell-surface markers present on both hematopoietic and skeletal muscle stem cells (CD34, Sca-1, and Flk-1) were also present on keratinocyte stem cells, and could be used to identify them. The cell-surface expression of cells that retained bromodeoxyuridine label for at least 21 d was compared with that of nonlabel-retaining cells. Double-labeling for flow cytometric analysis was employed, and label-retaining cells were found to lack expression of the tested markers. Beta1 integrin levels were also evaluated, and although high expression was found on label-retaining cells, it was not specific for these cells.

Animals↗
PubMed1999

Concomitant positive reactions to allergens in a patch testing standard series from 1988-1997.

BACKGROUND: Patch testing is a useful diagnostic technique in patients with suspected allergic contact dermatitis (ACD). Concomitant reactions may reflect associations between tested allergens. OBJECTIVE: This study was performed to identify positive correlations between reactions to test substances in a standard screening series. The results of patch testing in patients seen from 1988 to 1997 are described. METHODS: Data were collected from chart review for patients who underwent patch testing to the full standard screening series at the Massachusetts General Hospital Contact Dermatitis Clinic. The Fisher exact test was used to evaluate associations between allergens. RESULTS: A total of 927 patients were patch tested to 22 allergens included in a screening tray. The mean age was 43.9 years, and 68.6% were women. Two or more positive reactions occurred in 36.5% of patients. Reactions to 13 pairs of allergens were found to be significantly correlated: balsam of Peru/fragrance mix, carba mix/thiuram mix, carba mix/paraben mix, cobalt chloride/potassium dichromate, cobalt chloride/nickel sulfate, ethylenediamine/neomycin sulfate, formaldehyde/imidazolidinyl urea, formaldehyde/paraben mix, formaldehyde/quaternium-15, imidazolidinyl urea/quaternium-15, neomycin sulfate/potassium dichromate, paraben mix/quaternium-15, and potassium dichromate/thimerosal. CONCLUSION: Concomitant reactions to 13 pairs of allergens in a standard series occurred at a rate greater than would be predicted by chance. Such associations may reflect cross-sensitization or cosensitization.

Adult↗
PubMed1998

Novelty shop 'itching powder'.

To evaluate causes of itch, commercial 'itching powders' were sought for evaluation. Only one product, produced in Germany and consisting of ground rose hips, is currently sold in novelty shops in the Boston area. These plant fibres appear to provoke itch and prickle sensations by non-allergic mechanical stimulation, similar to the action of wool fibres.

Humans↗
PubMed1998

Lichen planus localized to the nails.

BACKGROUND: Lichen planus may rarely be localized to the nails. OBJECTIVE: A case of ungual lichen planus is reported that was misdiagnosed as onychomycosis. METHODS: A 52-year-old woman had progressive nail dystrophy for 13 months that was unresponsive to oral terbinafine. A nail biopsy was performed. RESULTS: Histopathologic findings were consistent with lichen planus. CONCLUSION: Onychomycosis may be confused clinically with other causes of nail dystrophy. It is important to confirm the diagnosis of onychomycosis with appropriate laboratory or histologic analysis.

Diagnostic Errors↗
PubMed1998

Patch testing reactions to a standard series in 608 patients tested from 1990 to 1997 at Massachusetts General Hospital.

BACKGROUND: Patch testing is a useful diagnostic tool when allergic contact dermatitis is suspected clinically. OBJECTIVE: This study describes the results of patch testing performed from January 1, 1990 to June 1, 1997 at the Massachusetts General Hospital Contact Dermatitis Clinic. The findings are compared with those previously reported by the North American Contact Dermatitis Group (NACDG). METHODS: Data were collected from chart review and analyzed. Patients included in the study underwent patch testing to the full European standard series of allergens. A standardized patch testing technique was used, and readings were performed by a single observer. RESULTS: A total of 608 patients were patch tested to a screening tray of 24 allergens; 69.9% were women. At least one positive patch test reaction was observed in 60.0% of patients. The most common sensitizers were nickel sulfate, fragrance mix, potassium dichromate, cobalt chloride, balsam of Peru, quaternium-15, and neomycin sulfate. The sensitization rate to potassium dichromate (9.4%) was higher than has been reported by the NACDG. A statistically significant difference in the sensitization rate in men and women was observed for nickel, quinoline mix, epoxy resin, and formaldehyde. The prevalence of positive patch test reactions was not found to be influenced by testing during the summer months. CONCLUSIONS: In the authors' opinion, the prevalence of contact sensitization is generally comparable with the findings of the NACDG, with the exception of reactions to potassium dichromate. This difference in results probably reflects, in part, differences in methodology. The test concentration of potassium dichromate was 0.5%, commonly used in Europe, instead of the 0.25% concentration used by the NACDG. Further investigation is necessary to determine the optimal testing concentration of potassium dichromate.

Adolescent↗