Comparative study of antiseptic toxicity on basal keratinocytes, transformed human keratinocytes and fibroblasts

The cytotoxic effects of a range of antiseptic agents were examined on cultured human fibroblasts and basal keratinocytes and compared to those on a transformed keratinocyte line (SVK 14 cells). Cells were exposed to chlorhexidine, hydrogen peroxide and sodium hypochlorite for 15 min and cell viability was assessed 24 h later with a colorimetric assay which utilizes the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT). At concentrations recommended for wound cleansing all agents produced 100% killing of all cell types. The results show that fibroblasts and keratinocytes, cells which are fundamental to the wound healing process are equally sensitive to the effects of the antiseptic agents tested, and are highly susceptible to the effects of free-chlorine containing agents. These observations are of particular importance to the use of cultured keratinocytes (culture grafts) to enhance wound healing; the application of antiseptics to such wounds is contraindicated. All three cell types tested showed similar susceptibilities to the agents tested. These findings suggest that the transformed cell line, which has the advantage of immortality and ready availability, can replace fibroblasts and keratinocytes in studies designed to investigate the adverse effects of antiseptic agents in vitro. Comparison of the ED50 concentration for each agent on all cell types to the standard use concentration produced a ranking order of toxicity which showed chlorhexidine to be the least toxic agent and sodium hypochlorite the most.(ABSTRACT TRUNCATED AT 250 WORDS)

Ichthyosis bullosa of Siemens and bullous ichthyosiform erythroderma--variants of the same disease?

A patient is described with features of both bullous ichthyosiform erythroderma (BIE) and ichthyosis bullosa--a separate entity first described in 1937 by Siemens. This combination of characteristics has not been previously reported. Bullous ichthyosiform erythroderma and ichthyosis bullosa of Siemens, occurring together in this patient may best be regarded as varying expressions of a single genodermatosis.

Keratin expression in human mammary epithelial cells cultured from normal and malignant tissue: relation to in vivo phenotypes and influence of medium

The luminal and basal epithelial cells in the human mammary gland can be distinguished in tissue sections on the basis of the pattern of keratins they express. Moreover, the invasive cells in primary carcinomas show a keratin profile that corresponds to that of the dominant luminal cell (7, 8, 18, 19). When homogeneous populations of luminal epithelial cells from milk or from breast cancer metastases are cultured the profile of keratin expression seen in vivo is maintained. We have therefore used monospecific antibodies reactive with individual keratins to examine the phenotype of cells cultured in three different media from reduction mammoplasty tissue that contains both luminal and basal cells. The phenotype of cells cultured from primary breast cancers in one of these media (MCDB170) has also been examined. In characterizing cell phenotypes, antibodies to a polymorphic epithelial mucin (PEM) expressed in vivo by luminal cells, and to smooth muscle (a) actin, expressed in vivo by basal cells, have also been used. Our results show that proliferation of different cell phenotypes is selected for in different media. In milk mix (MX) developed for growth of luminal cells from milk, only the luminal cell phenotype proliferates (for only 1 or 2 passages). In medium MCDB 170, which was developed for long-term growth of human mammary epithelial cells from reduction mammoplasty organoids, cells from the basal layer proliferate, while in MM medium the basal phenotype dominates, but a few cells with the luminal phenotype are found. Around passage 3, in medium MCDB 170, most cells senesce and a subpopulation of cells proliferates on further passage. These cells retain expression of the basal epithelial keratins but also express some features characteristic of luminal epithelial cells, suggesting that the basal layer may contain a stem cell that can develop along the luminal lineage. In culture, however, they do not express keratin 19, which in vivo is a feature of the fully differentiated luminal cell. The cells cultured from primary breast cancer in medium MCDB 170 have a similar keratin profile to that of the normal cells cultured in this medium. They do not express keratin 19, even though the invasive cells in primary cancers homogeneously express this keratin in vivo. The invasive phenotype, which in its keratin profile corresponds to the differentiated luminal cell and that of the metastatic cancer lines, cannot be cultured from primary breast cancers using MX, which supports proliferation of the corresponding normal cell.

A comparison of antibodies to type VII and type IV collagen laminin and amnion as epidermal basement membrane markers

We have compared four monoclonal antibodies which label basement membrane components using an indirect immunoperoxidase method in frozen sections of skin biopsies. The antibodies LH 7.2 and GB3 showed expression limited to epidermal and adnexal basement membrane. Antibodies to laminin and type IV collagen also decorated dermal blood vessels and stromal components. The antibodies LH 7.2 and GB3 are more suitable for labelling epidermal basement membrane in the study of cutaneous lesions.

Sporotrichoid spread of cutaneous Mycobacterium chelonei infection

Atypical mycobacterial infections of the skin have increased in frequency in immunocompromised individuals in recent years. Such patients may follow a different clinical pattern from immunocompetent patients, often lacking a history of preceding trauma and presenting with multiple suppurating subcutaneous nodules. A sporotrichoid pattern of spread may occur with the species Mycobacterium kansasii and M. marinum but is rare with M. chelonei.

Keratin 19: predicted amino acid sequence and broad tissue distribution suggest it evolved from keratinocyte keratins

The type I keratin 19 is unusual in its tissue distribution in that under normal circumstances it does not seem to be restricted, as the other keratins are, to expression in either stratified or simple epithelia. In addition to the previously reported distribution of keratin 19 in human tissues, we have observed keratin 19 in epidermal basal cells, in a defined region of the hair follicle, and in nipple epidermis. We noticed that expression of keratin 19 appears to be especially characteristic of regions of labile or variable cellular differentiation as indicated by the presence of multiple keratin phenotypes in close proximity to each other. Using a monoclonal antibody recognizing keratin 19 (LP2K) to screen a human placenta cDNA expression library, we have isolated, cloned, and sequenced cDNA coding for full-length human keratin 19, as confirmed by its reactivity with several other known anti-keratin 19 monoclonal antibodies and by the near identity of its sequence with that of the bovine keratin 19 homologue. This similarity extends to both proteins being truncated at the C-terminal end to only 13 amino acids beyond the rod domain. Although the amino acid homology over the N-terminal and helical rod domains is particularly high, the human and bovine proteins diverge substantially over the short C-terminal domain, which suggests that this region has no conserved function. Comparison with other type I keratins indicates that the closest evolutionary neighbors of keratin 19 are keratinocyte keratins, probably 13 and 14, and not the simple epithelial keratin 18. Assessing the histochemistry and sequence data together, we propose that the cell may use this apparently deficient keratin as a "neutral" keratin. While unimpaired in its ability to polymerize (keeping the cell integrated into the epithelial sheet via filament-desmosome networks), keratin 19 expression does not irrevocably commit a cell to any one of the local differentiation options. Such predicted differentiational flexibility may also imply vulnerability to transformation.

Expression of intermediate filament proteins in fetal and adult human lung tissues

The expression patterns of intermediate filament proteins in fetal and normal or nonpathological adult human lung tissues are described using (chain-specific) monoclonal antibodies. In early stages of development (9-10 weeks and 25 weeks of gestation) only so-called simple cytokeratins such as cytokeratins 7 (minor amounts). 8, 18 and 19 are detected in bronchial epithelial cells. At later stages of development, the cytokeratin expression patterns become more complex. The number of bronchial cells positive for cytokeratin 7 increases, but basal cells in the bronchial epithelium remain negative. These latter cells show, however, expression of cytokeratin 14 in the third trimester of gestation. Developing alveolar epithelial cells express cytokeratins 7, 8, 18 and 19. In adult human bronchial epithelium cytokeratins 4 (varying amounts), 7, 8, 13 (minor amounts), 14, 18 and 19 can be detected, with the main expression of cytokeratins 7, 8, and 18 in columnar cells and the main expression of cytokeratin 14 in basal cells. Vimentin is detected in all mesenchymal tissues. In addition, fetal lung expresses vimentin in bronchial epithelium, however, to a lesser extent with increasing age, resulting in the expression of vimentin in only few scattered bronchial cells at birth. Also in adult bronchial epithelium the expression of vimentin is noticed in part of the basal and columnar epithelial cells. Desmin filaments, present in smooth muscle cells of the lung, appear to alter their protein structure with age. In early stages of development smooth muscle cells surrounding blood vessels are partly reactive with some cytokeratin antibodies and with a polyclonal desmin antibody. At week 9-10 and week 25 of gestation a monoclonal antibody to desmin, however, is not reactive with blood vessel smooth muscle cells but is only reactive with smooth muscle cells surrounding bronchi. With increasing age the reactivity of cytokeratin antibodies with smooth muscle cells in blood vessels decreases, while the reactivity with the monoclonal desmin antibody increases. Our results show that during differentiation profound changes in the intermediate filament expression patterns occur in the different cell types of the developing lung.

Identification of the epidermolysis bullosa acquisita antigen by LH 7.2 monoclonal antibody: use in diagnosis

The sera from two patients with epidermolysis bullosa acquisita were blotted against dermal extracts in comparison with the mouse monoclonal antibody LH 7.2. This antibody reacts with carboxy terminal region of type VII collagen. The epidermolysis bullosa acquisita antisera showed binding to the same molecular weight protein as LH 7.2 confirming that the target antigen for epidermolysis bullosa acquisita antibodies is the carboxy terminal region of type VII collagen. This newly described collagen forms the major component of anchoring fibrils. These findings are consistent with established ultrastructural data which have shown that the epidermolysis bullosa acquisita antigen is located within and below the lamina densa. The monoclonal antibody LH 7.2 provides an internal standard for epidermolysis bullosa acquisita autoantisera activity. The use of immunoblotting of epidermolysis bullosa autoantisera in comparison with the monoclonal antibody LH 7.2 provides definitive investigation for the diagnosis of this disorder.

Type VII collagen antibody LH 7.2 identifies basement membrane characteristics of thin malignant melanomas

A monoclonal antibody (LH 7.2) to the carboxy terminal of type VII collagen has been used in an indirect immunoperoxidase method on frozen sections of biopsies of benign compound and intradermal cellular naevi, dysplastic naevi, and malignant melanomas, to label the epidermal basement membrane. Benign intradermal naevi had an intact membrane with the dermal naevus cell component lying beneath it. Compound naevi showed proliferating junctional nests of naevus cells pushing through the membrane towards the dermis beneath. In contrast, dysplastic naevi and melanomas showed a progressive displacement of the membrane downwards. Thin lesions were confined above the membrane. With increasing tumour thickness, discontinuities in the membrane were seen and foci of invasive growth through the line of the membrane were identified. These studies suggest that the good prognosis of thin melanomas is associated with confinement of the tumour within an expanded epidermis above the basement membrane.

Detection of basement membrane components and basal cell keratin 14 in noninvasive and invasive carcinomas of the breast

Using immunohistochemistry, the distribution patterns of basement membrane components type VII collagen (monoclonal antibody LH7.2), type IV collagen, and laminin were investigated in normal and malignant human breast tissue and compared with that of keratin 14 (monoclonal antibody LL002), which is expressed only by the basal (myoepithelial) cells in the secretory epithelia of the mammary gland. In normal breast tissue as well as in intraductal carcinomas, a more or less continuous basement membrane was observed at the epithelial stromal interface. Unlike laminin and type IV collagen, type VII collagen was not detected in the basement membrane of blood vessels. The keratin 14 antibody stained the basal cell layer of normal ducts and ducts with in situ cancer. In 85% of the invasive carcinomas no basement membrane or basal cells were detected. In 13 cases, however, laminin, type IV collagen, and/or type VII collagen were detected around tumor nests and individual tumor cells. Five of these tumors also showed a positive reaction with the keratin 14 antibody. In five cases keratin 14 expression was found without detectable basement membrane components. It is concluded that 18 of 103 invasive ductal breast carcinomas examined in this study exhibit a basal cell phenotype as determined from the expression of keratin and the deposition of basement membrane components.

Density-dependent modulation of synthesis of keratins 1 and 10 in the human keratinocyte line HACAT and in ras-transfected tumorigenic clones

The spontaneous human keratinocyte line HaCaT and c-Ha-ras oncogene-transfected cell clones are capable of expressing an unusually broad spectrum of keratins, not observed so far in epithelial cells. This expression is, however, strongly modulated by environmental conditions, including cell density. Both cells of the nontumorigenic HaCaT line and the tumorigenic HaCaT-ras clones, I-7 and II-3 (giving rise to benign and malignant tumors, respectively), constitutively expressed the keratins K5, K6, K14, K16 and K17, which are also common in cultures of normal keratinocytes. In addition keratins K7, K8, K18 and K19, generally associated with simple epithelia, were synthesized (to a most pronounced extent in sparse cultures), while keratins K4, K13 and K15 appeared at confluence, presumably with the onset of stratification. Moreover, in both HaCaT and HaCaT-ras clones the epidermal "suprabasal" keratins, K1 and K10, were expressed in conventional submerged cultures (at normal vitamin A levels), markedly rising with cell density, but not strictly correlated with the degree of stratification. This property was maintained in HaCaT cells up to the highest passages. According to immunofluorescence, this was due to increasing numbers of strongly stained cells, and not due to a gradual increase in all cells. Most strikingly, there was a significant delay in the appearance of K10 compared to K1, and this dissociation of expression was most evident in dispase-detached cell sheets (submerged cultures) and organotypic cultures of the ras clones (grown at the air-liquid interface). While on frozen sections bright staining for K1 was seen in some basal and virtually all suprabasal cell layers, K10 was largely restricted to the uppermost layers. Thus, obviously synthesis of K1 and K10 can be regulated independently, although generally in this given sequence. The apparent compatibility of K1 synthesis with proliferation and particularly the extended delay of K10 expression (as a postmitotic event) might be causally related to altered growth control and as such imply the significance of this disturbance. Finally, the highly preserved epidermal characteristics, in terms of expression of keratins (and other differentiation markers [5]) and their regulation, makes these cell lines excellent candidates for studying external modulators of differentiation and also underlying molecular mechanisms.

Intra-epidermal neutrophilic IgA dermatosis with colitis

We report the association of an intra-epidermal blistering disease of the skin with colitis. Both the skin and large bowel epithelium were infiltrated by neutrophils and eosinophils, and showed intra-epithelial deposition of IgA in an intercellular pattern. The colitis and the blisters responded well to treatment with dapsone.

Gamma-interferon induced human keratinocyte HLA-DR synthesis: the role of dermal activated T lymphocytes

Experiments were performed to examine the hypothesis that the surface expression of HLA-DR by keratinocytes in certain disease states is conferred by the activity of gamma-interferon, derived from dermal activated T lymphocytes. In vivo studies revealed a spatial relationship between keratinocyte HLA-DR expression and activated T lymphocytes within the dermal inflammatory infiltrate. In vitro studies confirmed that gamma-interferon can induce keratinocyte synthesis of HLA-DR. These results suggest that, in vivo, gamma-interferon produced by activated T lymphocytes induces keratinocyte HLA-DR synthesis and expression.

Management of non-genital herpes simplex virus infections in immunocompetent patients

Non-genital herpes simplex virus in immunocompetent hosts causes a variety of primary infections--gingivostomatitis, keratoconjunctivitis, herpetic whitlow, and encephalomyelitis. Recurrent infections with orolabialis are very common, but are usually mild and self-limiting. Cutaneous complications of herpes simplex virus infections include eczema herpeticum and erytherma multiforme. Systemic treatment with acyclovir is indicated in encephalomyelitis, progressive eczema herpeticum, and frequent severe erythema multiforme. Chronic, suppressive acyclovir treatment may be helpful in severe recurrent infections or those complicated by erythema multiforme/dissemination. Many primary and recurrent infections can be treated with simple topical therapy to control secondary infection. There is no evidence that systemic treatment affects viral latency or recurrent infections following discontinuation of treatment.

Darier's disease: an immunohistochemical study using monoclonal antibodies to human cytokeratins

The pathogenesis of Darier's disease was investigated by immunohistochemical staining of skin biopsies from involved and uninvolved skin in 14 patients, using monoclonal antibodies specific for keratins expressed in simple epithelia, stratified squamous epithelia and during skin specific differentiation as well as keratins expressed in mucosa and some benign epidermal hyperproliferative states. Uninvolved perilesional skin from Darier's patients showed a normal profile of keratin expression, whereas in lesional skin there was apparent delay in the expression of the suprabasal skin specific keratins. Suprabasal keratins were not detected in basal cells, thus there was no true premature keratinization. The presence of hyperproliferative keratins was restricted to suprabasal cells in lesional skin. Four patients were receiving treatment with etretinate at the time of biopsy, but results in these patients did not differ from patients using topical treatments. Etretinate did not influence the profile of keratin expression in uninvolved or involved skin. The expression of type VII collagen was examined and was normal throughout uninvolved and lesional skin in Darier's disease.

Type VII collagen is a normal component of epidermal basement membrane, which shows altered expression in recessive dystrophic epidermolysis bullosa

The murine monoclonal antibody LH 7:2, which reacts with the basement membrane of stratified squamous epithelia including epidermis, has been characterized biochemically and shown to bind to part of the type VII collagen molecule. Immunoblotting reveals that the antibody binding site lies in the non-helical carboxy terminal region of the type VII collagen dimer and immunoelectron microscopy shows that the epitope is within the lamina densa of the basement membrane. Loss of LH 7:2 binding in the hereditary blistering disease recessive dystrophic epidermolysis bullosa suggests that inadequate synthesis or excessive breakdown of type VII collagen may form the biologic basis for the disease.

Treatment of chronic venous ulcers with sheets of cultured allogenic keratinocytes

Cultured keratinocytes were used as allografts to treat 51 patients with chronic venous ulceration or rheumatoid ulcers unresponsive to all previous conventional treatments including split skin grafts. Although early epithelialization could be seen in the centre of some ulcers, a major effect appeared to be healing from the previously indolent edge. This treatment appears to provide some clinical benefit in healing of chronic ulceration.

Dermatomyositis and pulmonary fibrosis associated with anti-Jo-1 antibody

Although fibrosing alveolitis is a rare complication of dermatomyositis, early detection and treatment are important in preventing pulmonary fibrosis. Anti-Jo-1 antibody, an antibody to the cellular enzyme histidyl-t-RNA synthetase, has been found to correlate closely with the subset of dermatomyositis/polymyositis associated with fibrosing alveolitis. This association is well known to rheumatologists but has received little attention in the dermatologic literature. We wish to alert dermatologists to the importance of the association of anti-Jo-1 antibody in patients with dermatomyositis and present a patient with anti-Jo-1 antibody who had Raynaud's phenomenon and mild arthritis in association with dermatomyositis and pulmonary fibrosis. We suggest screening patients with polymyositis/dermatomyositis for this antibody, to detect the population at high risk of developing pulmonary complications.

Potential applications of anti-keratin antibodies in oral diagnosis

Recent progress in understanding the biology of keratins together with the development of monoclonal antibodies to individual keratin proteins provide the foundation for studying keratin expression in normal and pathological oral epithelia. Areas of oral pathology in which the examination of epithelial keratin profiles may yield information of potential diagnostic value are discussed. Examples of altered keratin expression in epithelial dysplasia, oral cancer and odontogenic cysts and tumours are presented. Immunocytochemical demonstration of individual keratins can clarify the composition of complex epithelia and may help to establish epithelial lineage or indicate progression changes in tumours. Some problems in the application and interpretation of keratin immunocytochemistry are also considered.