J. De Bersaques

A comparative immunohistochemical study of cytokeratin and vimentin expression in middle ear mucosa and cholesteatoma, and in epidermis

Cytokeratin expression was studied in human middle ear cholesteatoma lesions, using a variety of immunohistological techniques and a wide range of polyclonal antisera and monoclonal antibodies against cytokeratin (CK) subgroups or individual CK polypeptides. The expression of the other cytoskeletal proteins, vimentin and desmin, was also investigated. Middle ear mucosa and epidermal tissues were used as reference tissues. Our investigations also included epithelial structures present in the cholesteatoma perimatrix and in dermal tissues. The results indicate that, compared with epidermal tissues, the expression profile of CKs in cholesteatoma matrix is representative of a hyperproliferative disease. Evaluating the presence of a marker of terminal keratinization - the 56.5 kD acidic CK no 10 - we found supportive evidence of a pronounced retardation of its expression, which did not parallel histological differentiation. In epidermal tissues, the first prickle cell layers are CK10 positive whereas in many cholesteatomas this finding was observed near the stratum granulosum only. Probing the early stages of keratinization -the 58 kD basic CK no 5 and the 50 kD acidic CK no 14 - we regularly observed an extended staining area in the cholesteatoma matrix. In epidermal reference tissues, only the basal and nearest suprabasal layers were convincingly labeled. As a rule, non-epidermal CKs did not belong to the cholesteatoma CK set. However, exceptions to that rule were noticed as a focal or more extended expression of one or more non-epidermal CKs in about half of the cases. Together with the extended CK5 topography, this is further evidence that CK expression is seriously affected by the diseased state. CK expression in the perimatrix is limited to mucous glands, either normal, atrophic or hyperplastic. CKs no 4, 5, 7, 14, 18 and 19, also displayed by middle ear mucosa, were consistently observed. Where ductal arrangements were present, CK10 was also detected, in analogy with the CK10 registration in ductal portions of mucous glands in the external ear canal skin. The absence of CK8 in mucous glands of the perimatrix, however, strongly differentiates these structures from the mucous gland acini and ducti in the external ear canal, where CK8 is systematically expressed. Vimentin staining was restricted to dendritic cells of the matrix (Langerhans cells) and to perimatrix fibroblasts, blood cells and vascular endothelium. Coexpression of CK and vimentin was not observed.

An investigation of cytokeratin expression in skin epithelial cysts and some uncommon types of cystic tumours using chain-specific antibodies

SummaryThe differentiation state of skin epithelial cysts and some uncommon types of epithelial skin tumours was investigated by immunohistochemical staining, mainly using cytokeratin (CK) polypeptide-specific monoclonal antibodies. Samples of interfollicular epidermis, hair follicles and eccrine sweat glands were included as reference tissues. The CK reactivity in epidermoid cysts and milia is not restricted to CKs involved in epidermal-type differentiation, i.e. CK1, 5, 10 and 14, but in addition CK16, a hyperproliferative keratinocyte marker is suprabasally expressed. CK1 and 10 are other prominent suprabasal markers, while CK14 seems to be preferentially expressed in the basal cell layer. Of the non-epidermal CKs, only CK4 was focally or more extensively detected in about 50% of the cases. In terms of CK reactivity, keratinization of trichilemmal cysts corresponds to the keratinization of the anagen-phase hair follicle in the isthmus. The CK reactivity is again restricted to CK1, 5, 10, 14 and 16. However, the CK1 as well as CK10 reactivity is subject to serious limitations, since both CKs were only convincingly observed in foci of terminal differentiation. Eccrine hydrocystoma obligatorily expresses a complex CK set, including CK7, 8, 14, 18 and 19. This CK set perfectly corresponds to the CK composition observed in acini of eccrine sweat glands. In addition, a discontinuous CK4 and 16 reactivity was seen in about 50% of the sites, while CK1 and 10 displayed a strictly focal appearance. On the other hand, syringoma produces in its distinct structures, a CK pattern reminiscent of the one observed in eccrine sweat gland ducts and includes CK1, 5, 10, 14, 16 and 19. Finally, the CK expression pattern of pilomatricoma includes CK1, 8, 10, 14 and 19, and is reminiscent of the CK staining of hair bulb matrix cells differentiating in the keratogenous zone in the direction of hair cortex. The reactivity of CK1 and 10 was mainly restricted to foci of squamoid differentiation and also to transitional cells bordering on shadow cells, as far as it concerns CK10. Occasionally, CK7 and 16 were observed in individual cells or small cell groups. In our view these CK reactivity patterns are useful to judge the differentiation state reached in pathological conditions, but so far do not allow us unequivocally to determine the site of origin of these lesions.

Acitretin as cancer chemoprophylaxis in a renal transplant recipient

The use of acitretin in a renal transplant recipient who had been treated for several premalignant and malignant skin lesions is the subject of this case report. During the treatment period no new dysplastic lesions developed.

An immunohistochemical and histochemical study of cytokeratin, involucrin and transglutaminase in seborrhoeic keratosis

The mode of differentiation of seborrhoeic keratoses was investigated by immunohistochemical staining using cytokeratin (CK) polypeptide-specific monoclonal antibodies and an antibody specific for the particulate form of epidermal transglutaminase (ETgase), and by applying an anti-human involucrin serum. The role played by (E)Tgase was further evaluated using an activity assay based on the covalent attachment of monodansylcadaverine. Samples of uninvolved epidermis served as reference tissue. CK reactivities suggested that seborrhoeic keratoses is a hyperproliferative disease with an epidermal CK composition. CK5 and CK14 were prominent markers of basal and basaloid keratinocytes, whereas a decrease in staining occurred in advanced maturation stages and areas of terminal keratinization. In contrast, CK1 and CK10 were prominent markers of suprabasaloid differentiation stages and produced complementary stainings to those of CK5 and 14. Generally, CK10 staining was more impressive than CK1 staining and seemed to start before CK1 staining. In contrast to CK10 staining, cornified areas lost CK1 reactivity. These staining patterns were similar to those observed in uninvolved reference tissues. The epidermal CK subset was further supplemented with the ‘hyperproliferative’ CK6 and 16 which occur sequentially. Positive staining for CK6 was noted from basal and proximal basaloid cells onwards, whereas distal basaloid cells additionally showed CK16 staining. The presence of other non-epidermal CK polypeptides could not be shown. The competence for other differentiation markers belonging to the group of (E)Tgase and cornifying cell membranes also evolved with a typical epidermal pattern. (E)Tgase activity was restricted to advanced and terminal stages of keratinization and was dual in nature, i.e. a diffuse cytoplasmic staining occurred together with a prominent staining of cornifying cell membranes. Similarly, involucrin first detected in the cytosol of distal basaloid cells, was soon translocated to the cornifying cell membrane, reflecting its function as an ETgase substrate and precursor of the marginal band. Finally, the immunolocalization of the particulate form of ETgase was strikingly similar to the location of the first two markers. Taken together, the results allow us to conclude that seborrhoeic keratoses exhibits a hyperproliferative variant of the epidermal keratinization process. Maturation of basal keratinocytes is greatly retarded leading to an accumulation of basaloid cells which retain the molecular markers of basal cells in proximal areas, but progressively gain the molecular markers of advancing maturation in distal areas.

RELATION BETWEEN THE ABSORPTION AND THE QUENCHING OF LIQUID SCINTILLATION SAMPLES

During scintillation counting of labeled amino acids in hairs, brown- colored solutions were formed when the hairs were dissolved in Hyamine X-10. In order to see whether the quenching is related to the optical density of the solution, measurements with a Tri-Carb spectrometer were made on solutions of hair, phosphor, and H/sup 3/-leucine or S/sup 35/-cystine. The relation between quenching and density at 430 m was found to be linear up to 50% quenching for both labeled compounds. (D.L.C.)

Nuclear differentiation and ultimate fate during epidermal keratinization

SummaryQuantitative DNA cytophotometric investigations were performed to clarify some aspects of the differentiation and fate of nuclei in bovine snout and human epidermis representing various sites and different degrees of keratinization. We elaborated optimal conditions for hydrolysis and Feulgen staining. Diverse cytophotometric techniques, including computerized scanning cytophotometry and image analysis were applied. This approach provided the first quantitative data concerning changes of nucleotype during soft keratinization.Cytophotometric DNA measurements provide evidence for a continuous decline of nuclear DNA content from immediately beyond the basal layer to the transition zone. The overall loss of DNA is an orderly process that intensifies gradually and culminates in the stratum granulosum. Gradual nuclear degeneration, however, is not a general phenomenon, and a significant number of nuclei retains a DNA content within the diploid limits throughout the entire stratum spinosum and part of the stratum granulosum. At any level of differentiation or decay, residual nucleoprotein complexes remain intact, as judged from their resistance to acid hydrolysis.Karyological features change completely during keratinization. Basal cell nuclei are rather compact, ellipsoid and heterochromatic. Beyond the basal layer, nuclei enlarge, round up and obviously evolve to an extremely euchromatic state, with preferential localization of the dispersed heterochromatic clumps at the more peripheral sites. In the upper stratum spinosum, nuclei undergo even more drastic changes: nuclear area and volume shrink, nuclei partially regain the ellipsoid shape and revert to heterochromasia. Nevertheless, euchromatin remains the major constituent of decaying nuclei. Terminal differentiation stages, except in human sole, are marked by heterochromatin clumping. In human sole, persistence or even progression of heterochromatin dispersion is observed. Heterochromatic dots are situated along the nuclear membrane in human terminal keratinocytes, but are almost randomly distributed in bovine stratum granulosum nuclei. Finally, nuclear contrast analysis partially reveals statistically significant changes throughout keratinization.

Leucine aminopeptidase and naphthylamidases in human epidermis

ZusammenfassungNaphthylamidasen und Peptidasen sind in normaler und psoriatischer Haut und in Basaliomen bestimmt worden. Hohe Aktivitäten wurden in psoriatischer Epidermis und in dem peritumoralen Stroma gefunden. Es wird versucht, die Gründe der Differenz zwischen biochemischen und histochemischen Resultaten zu erklären.SummaryNaphthylamidases and peptidases were determined in normal and psoriatic skin and in basal cell tumors. High activities were found in psoriatic epidermis and in the tumor stroma.Histochemical images are given for comparison; possible reasons for discrepancies between biochemical and histochemical results are presented.

Improved quantitation of 13-cis- and all-trans-acitretin in human plasma by normal-phase high-performance liquid chromatography

A reliable analytical method has been developed for measurement of 13-cis- and all-trans-acitretin (Neotigason) in human plasma by normal-phase high-performance liquid chromatography, with ultraviolet detection. Human plasma was obtained after centrifugation of whole blood samples and deproteinized by ethanolic denaturation. After liquid-liquid extraction with water-n-hexane, and aliquot ws chromatographed on a silica column using isocratic elution with n-hexane-methylsalicylate-acetic acid (200:18:0.6, v/v). The wavelength was set at 360 nm, and for plasma samples a limit of quantification of 3-4 ng/ml was obtained. All manipulations were carried out under dim light conditions to prevent photoisomerization.

A Retrospective Study of the Inpatient Treatment of Psoriasis with Dithranol

This study reports the results of the Ingram dithranol regimen for the treatment of psoriasis in 275 inpatients. The median duration of hospitalization until clearance was 25 days and the medians of the interval until a next treatment or hospitalization was needed were 11 and 8.5 months, respectively.

Short-Duration Dithranol Therapy for Psoriasis

40 outpatients with psoriasis vulgaris of limited extent were treated with daily brief applications of a 1, 2 or 3% dithranol ointment. The treatment was effective in cases of large plaques, small lesions and guttate psoriasis. There was a very poor therapeutic response in palmoplantar psoriasis and in residual lesions after Ingrams regimen.