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D R Benjamin

Publications and source records attributed to D R Benjamin.

86 records · Page 5Linked to original sources
PubMedDate not supplied

Cellular composition of the angiofibromas in tuberous sclerosis.

The angiofibroma of tuberous sclerosis is associated with a proliferation of dermal spindle cells that have been considered to be fibroblasts on the basis of a variety of techniques, although some cells have a glial appearance. This study of six angiofibromas demonstrated an increase in S100-positive, peanut agglutinin-negative spindle cells in the dermis in addition to increased numbers of epidermal melanocytes. The second major spindle cell population in the dermis proved to be dermal dendrocytes based on their expression of factor XIIIa. The number of these cells decreases in older patients, in whom the lesions were generally less cellular and more fibrotic. The angiofibroma of tuberous sclerosis is a hamartoma involving increased numbers of dermal dendrocytes, neurosustentacular cells, blood vessels, and melanocytes, in addition to collagen.

Adolescent↗
PubMedDate not supplied

Proliferating cell nuclear antigen (PCNA) and pediatric tumors: assessment of proliferative activity.

Monoclonal antibodies to proliferating cell nuclear antigen (PCNA) were used to detect proliferating cells in pediatric tumors fixed in Carnoy's solution. The percentage of staining cells was quantified using image analysis and compared to the S + G2M phase fraction as determined by flow cytometry. Although there was a general correlation between these indices of cellular proliferation, some variation was noted between tumor systems as well as within a specific tumor type. In some cases this variation was easily explicable by the morphologic findings (e.g., tumor heterogeneity and sampling differences, stromal cell proliferation, necrosis, extramedullary hematopoiesis), whereas in others it appeared to be an intrinsic property of the cell line. It is concluded that PCNA immunostaining is a useful and reproducible method of assessing one aspect of cellular proliferative activity and especially of addressing the questions, "which cells are dividing and where?" It has some advantages over flow cytometry in that it maintains tissue integrity and morphologic relationships.

Antibodies, Monoclonal↗
PubMedDate not supplied

The pendulum.

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Clinical Laboratory Techniques↗