William L. Epstein

Updating the maximization test for identifying contact allergens.

The maximization test for detecting contact allergens has proved to possess both sensitivity and specificity. However, modifications have become necessary because of excessive irritancy reactions to sodium lauryl sulfate. Fewer exposures are now recommended during induction and lower concentrations for challenge patch testing. Pre‐testing of each subject in the panel is now standard procedure. The problem of interpreting challenge patch tests is discussed in detail.

The regressing thin malignant melanoma. A distinctive lesion with metastatic potential

To validate the supposition that thin malignant melanomas (less than 0.76 mm thick) of ordinarily low risk but with areas of regression may paradoxically metastasize, we observed 121 thin malignant melanomas over a six year period. Of these, 23 displayed readily apparent areas of regression, of which five (21.7%) metastasized. The incidence of metastases in their 98 counterparts without regression was 2.0% (2/98). The difference between the two is statistically significant (p = less than .01). Of the entire group of thin melanomas, those with regression represented 19.0% (23/121) yet accounted for a disproportionate 71.4% (5/7) of all metastases. We conclude that regression is a relatively poor prognostic sign, whose occurrence within an otherwise thin melanoma represents a significant caveat to the current histologic staging system that equates thinness with low risk. We thus submit that patients whose malignant melanomas display regression be followed rigorously for evidence of metastases irrespective of the tumors actual measured thickness or level of invasion. Cancer 42:2282–2292, 1978.

Defect in DNA synthesis in skin of patients with xeroderma pigmentosum demonstrated in vivo.

Exposure of normal human skin in vivo to ultraviolet irradiation at wavelengths shorter than 320 nanometers stimtulated an unscheduled DNA synthesis in all of the cell layers of the epidermis and in the upper dermnial fibrocytes. The skin of patients with xeroderma pigmentosum did not show this response. correlation of these findings with previous tissue culture studies suggests that the defect in repair of the damaged DNA in xeroderma cells occurs in vivo as well as in vitro.

EARLY EFFECTS OF ULTRAVIOLET LIGHT ON DNA SYNTHESIS IN HUMAN SKIN IN VIVO.

The early effects of ultraviolet light (UV) irradiation on deoxyribonucleic acid (DNA) synthesis in human skin were studied in vivo. Volunteers exposed to 3 minimal erythema doses (MED) (8.2-40.8 × 106ergs/sq cm) were injected intradermally with tritiated thymidine (TdR-H3), immediately, 15 minutes, 3, 5, and 24 hours afterward, and biopsies processed for light microscopy autoradiography. Comparison of the results with findings in unirradiated human skin indicated: (1) a depression in the number of germinative basal cells synthesizing DNA prior to division at three and five hours after UV, as seen in other systems; (2) a population of sparsely labeled cells not only in the basal layer but also in the malpighian and granular layers and not seen in unirradiated skin or after several other types of acute injury. This aberrant type of TdR-3H incorporation has been seen in other systems and is thought to represent dark reactivation repair of irradiated DNA as occurs in microorganisms.

Biopsy method for human adipose with vitamin E and lipid measurements

An adaptation of the needle biopsy procedure of Beynen and Katan for human adipose tissue, which yields 2–10 mg adipose samples, is described and evaluated. Micromethods are presented for the analysis of α-tocopherol, cholesterol and fatty acids in each adipose specimen. The needle biopsy procedure, which uses a Vacutainer to create suction, is compared with a punch biopsy method. The needle biopsy is rapid (6 samples/hr), simple and unobjectionable to the subjects, and provides samples with reproducible ratios of cholesterol and α-tocopherol. Unlike the punch biopsy, the needle biopsy reliably obtains specimens with a lipid composition typical of adipocytes. The needle biopsy method is adaptable to nutritional studies of tocopherol and fatty acid metabolism in adipose, and to studies of hazardous compounds stored in adipose. The linoleic acid content of adipose from residents of the West Coast was found to be considerably higher than values reported earlier. The adipose fatty acid data indicate an increase in human adipose linoleate when compared with earlier reports and suggest a trend toward increasing linoleic acid in the American diet.

A comparative autoradiographic study of keratohyalin granules containing cystine and histidine

Ultrastructural localization of cystine containing protein in keratohyalin granules of newborn rats was studied and compared with that of histidine containing protein using radioisotope-labeled precursors and autoradiographic techniques. The frequency of radioactive labels appearing over keratohyalin granules after injection of ( 3 H)cystine was not as high as after injection of ( 3 H)histidine. However, analysis of grain counts indicated that a cystine containing protein concentrates in the dense homogenous deposits (DHD) of keratohyalin granules. The number of labels in the center of keratohyalin granules increased. The incidence of labels over the keratohyalin granulelike inclusions in the nuclei of granular cells also increased with time. Histidine containing protein in contrast concentrated elsewhere in keratohyalin granules than in DHD. These findings demonstrate that keratohyalin granules are made of heterogenous constituents of different chemical composition; at least one is a protein relatively rich in cystine and another contains high levels of histidine.

Immunochemical comparison of histidine-rich protein in keratohyalin granules and cornified cells

(1) Combination of techniques for extraction and purification of histidine rich protein established by several investigators were employed for comparison of histidine-rich protein in granular cells and cornified cells of newborn rats. (2) Histidine-rich protein extracted from the same cell fraction by two different techniques either in 1 M potassium phosphate buffer (Ugel) or in 4 M urea (Dale) showed identical elution profiles on CM 52 cellulose ion exchange chromatography and the same SDS polyacrylamide gel electrophoretic patterns. (3) Histidine-rich protein from granular cells contained polypeptides of larger molecular sizes than those in histidine-rich protein from cornfield cells, although amino acid composition of the two histidine-rich protein was non-distinguishable (histidine residue was more than 7%). (4) Antibodies raised in rabbits by injection of histidine rich protein from granular cells and that from cornfield cells immunologically cross-reacted. Furthermore, the antisera were found to be reactive over both keratohyalin granules and cornified cells, but not epidermal cells of the lower strata.

Nuclear changes during keratinization of normal human epidermis.

Previous workers have shown step-by-step changes in the cytoplasm of the granular cells during differentiation (keratinization) of human epidermis, including enlargement of the keratohyalin granules and the appearance and migration to the distal plasma membrane of the membrane coating granules. Our study of the granular cell nucleus shows changes correlated with the cytoplasmic differentiation: With accumulation of cytoplasmic keratohyalin, the nucleus becomes flattened and the nuclear membrane becomes indented. Nuclear bodies are infrequently seen as concentrically arranged fibrils. The nucleolus loses its initial netlike (nucleolonemal) pattern and becomes dense. At the same time round, homogeneous dense inclusions appear in the nucleus with special concentration around the nucleolus. These dense nuclear inclusions have been observed in epithelia of other species and may reflect the process of keratinization.

Dermatitis from cashew nuts

Between April 4 and May 10, 1982, fifty-four individuals developed a poison ivy-like dermatitis 1 to 8 days after eating imported cashew nuts. The patients had a very pruritic, erythematous, maculopapular eruption that was accentuated in the flexural areas of the body. Three had blistering of the mouth and four had rectal itching. Nineteen volunteers (eleven ill and eight well) were patch-tested with 2.5 micrograms of poison ivy urushiol and an acetone extract of cashew nut shells. Patch testing did not predict illness since positive tests to both materials occurred in those who had been ill as well as in those who had been well. Absence of cashew nut shells from two thirds of the bags probably accounted for the lack of correlation between patch testing and illness. All nine who reacted to the cashew extract also reacted to poison ivy urushiol. The three who were not sensitive to poison ivy had no reaction to cashew extract. Mass spectrometry of the cashew shell extract suggested the presence of cardol , one of the allergens in cashew shell oil.

Ultrastructural studies of newborn rat epidermis after trypsinization.

Ultrastructural changes observed in newborn rat epidermal cells after trypsinization were studied. Trypsin separated epidermis from dermis by dissolving the electron dense basement lamina and caused the separation of the desmosomes at their intercellular junctions by dissolving the interdesmosomal structure. Separated epidermal cells rounded up and exhibited numerous cytoplasmic processes as a result of retraction of semidesmosomes toward the center of cells. Cytoplasmic organelles, such as mitochondria, microtubules, endoplasmic reticulum, and tonofilaments, were situated near the nucleus and the cytoplasm between the retracted tonofilaments and the plasma membrane contained mostly ribosomes. The altered morphology of epidermal cells resembles that found in pathological skin conditions such as pemphigus, malignancy, and wound healing. After trypsinization a fine periodicity 300 A became apparent in tonofilaments. This finding should be taken into account in physicochemical studies concerned with the characterization of tonofilaments.