Overexpression of mutant ras in human melanoma increases invasiveness, proliferation and anchorage-independent growth in vitro and induces tumour formation and cachexia in vivo.

Malignant melanoma is the deadliest form of skin cancer. Previous studies have shown that the incidence of ras mutation increases with progression of melanoma, but that such mutations may not be present in the earliest radial growth phase melanomas. Recently it has been proposed that introduction of ras mutations into cells deficient in tumour suppressor genes such as p16 (INK4a) is sufficient to induce characteristics of cellular transformation such as anchorage-independent growth and tumour formation in vivo. To test this hypothesis in human melanoma, mutant N-ras, mutant H-ras or wild-type H-ras genes were transfected by electroporation into WM35 cells, a p16-deficient human melanoma cell line of low invasive potential. Increased expression of mutant ras p21 enhanced anchorage-dependent cell growth on tissue culture plastic. In addition, overexpression of mutant N-ras and H-ras, but not of wild-type H-ras, increased the experimental invasive potential, inducing anchorage-independent growth in soft agar, increasing cell motility measured by time-lapse video microscopy, and increasing invasiveness through reconstituted basement membranes. Finally, overexpression of mutant H-ras in melanoma cells was shown to increase tumorigenicity and to induce cachexia when H-ras transfected cell lines were injected subcutaneously in severe combined immunodeficiency (SCID) mice. Thus the addition of activating ras mutations to a melanoma cell line already deficient in p16 leads to enhanced proliferation, survival and migration in vitro and to enhanced subcutaneous tumour formation in vivo. This phenotype is typical of the behaviour of vertical growth phase (VGP) melanoma, and we propose that activation of the ras signalling pathway in the presence of deletions in p16 or related tumour suppressors can induce the VGP melanoma phenotype.

Waldenström macroglobulinemia-induced bullous dermatosis.

BACKGROUND: Waldenström macroglobulinemia is a plasma cell dyscrasia of undetermined cause characterized by the monoclonal proliferation of lymphoplasmacytes in the bone marrow, lymph nodes, and spleen and elevated circulating levels and tissue deposition of monoclonal IgM produced by these aberrant cells. Rarely, cutaneous manifestations of this disease have been reported. OBSERVATIONS: We report the case of a patient with bullous dermatosis induced by Waldenström macroglobulinemia and demonstrate the subepidermal location of the separation and the presence of IgM and kappa light chains by immunoperoxidase, immunofluorescent techniques, and electron microscopy with immunogold staining. Immunoblotting revealed a strong band at the 290-kd area. CONCLUSIONS: The demonstration of the separation in the upper dermis at the site of IgM deposits suggests that these deposits may be an etiologic factor in this rare manifestation.

Hypermelanotic nevus: clinical, histopathologic, and ultrastructural features in 316 cases.

We report on a series of benign melanocytic nevi that have unique clinical, histopathologic, and ultrastructural features. Between March 1993 and February 1994, 316 examples of hypermelanotic nevi were received by the dermatopathology laboratory at Denver General Hospital. Our study identified the clinical characteristics, histopathologic criteria, and ultrastructure of this lesion. Clinically, the lesions were dark brown to black macules or papules. The most common location was the back. There was a slight female predominance, and the mean age of our patients was 40 years. Histopathologically, the nevus showed the following characteristics: (a) melanin within a compact stratum corneum, (b) small nests of nevus cells at the dermal-epidermal junction and (in 52% of the cases), nests within the papillary dermis, (c) heavy melanin within keratinocytes in the lower epidermis, (d) a sparse to moderate lymphocytic infiltrate and melanophages in the superficial dermis, and (e) an absence of cytologic atypia. Electron microscopy revealed that abundant melanin was packaged in melanosome complexes within keratinocytes. Less pigmented melanocytes and nevus cells contained well-developed dendritic processes and golgi, indicative of efficient melanin transfer. According to our retrospective case control analysis, patients with hypermelanotic nevi were older and more likely to be male than those with ordinary nevi. Hypermelanotic nevi were more likely than controls to be junctional nevi; they were smaller, dark brown or black in color, and clinically suspicious for melanoma. We propose the name "hypermelanotic nevus" to describe this benign lesion, which is often biopsied to exclude melanoma.

Human keratinocytes maintain reversible anti-apoptotic defenses in vivo and in vitro.

Human keratinocytes proliferate and differentiate in an epidermal environment where induction of apoptosis can be triggered by ultraviolet radiation (UVR), activated lymphocytes and cytokines. The purpose of this study was to determine whether keratinocytes were susceptible to apoptosis induced by ionophore, ultra-violet radiation, cytokines or crosslinking of CD95 (Fas/APO-1). In normal human skin exposed to two minimal erythema doses of ultraviolet radiation, suprabasal cells were the first keratinocytes to demonstrate apoptotic nuclei, and by 48 h apoptotic cells were identified throughout the mid to upper epidermis. However, most keratinocytes resisted apoptosis and UVR-induced apoptosis was not observed in basal cells, or in the most differentiated epidermis. Human keratinocytes and keratinocyte cell lines cultured in vitro developed maximal apoptosis 48 h after radiation. Human keratinocytes cultured in full growth factor supplements were resistant to UVR-induced apoptosis compared to keratinocyte cell lines or to a lymphoid cell line (HL60) susceptible to apoptosis. Keratinocyte cell lines were completely resistant to apoptosis induced by interferon-gamma, interferon-alpha, IL-2, IL-6, TNF-alpha, IL-1Ra, and GM-CSF. A subset of the cells in cultures of keratinocytes and transformed keratinocyte cell lines died by apoptosis in response to anti-Fas, IL-1alpha and TNF-alpha plus IFN-gamma and ionophore. Second passage freshly isolated human keratinocytes were much more resistant to apoptosis induced by ionophore, anti-Fas and cytokines than were transformed keratinocyte cell lines. Calcium shift to induce differentiation in second-passage keratinocyte cultures made keratinocytes even more resistant to UVR-induced apoptosis. This parallels the lack of UVR-induced apoptosis observed in the most differentiated keratinocytes in irradiated human skin. Both keratinocytes and keratinocyte cell lines express rather low levels of the anti-apoptotic proteins bcl-2 and bcl-x compared to other apoptosis-resistant cell types. The differences between keratinocytes and keratinocyte cell lines in susceptibility to apoptosis are not explained by difference in expression of bcl-2 or bcl-x. Finally, withdrawal of growth factors from keratinocytes decreased cell survival following UVR and increased the induction of apoptosis. Inhibition of protein synthesis with cyclo-heximide also made keratinocytes more susceptible to UVR-induced apoptosis, indicating that anti-apoptotic defences in cultured keratinocytes are dependent on active protein synthesis. These experiments show that the strong keratinocyte defences against apoptosis are stratified within the epidermis, and can be altered by differentiation and growth factor withdrawal.

Etiologies of the sicca syndrome: primary systemic amyloidosis and others.

BACKGROUND: The sicca syndrome has been defined as the occurrence of xerostomia and xerophthalmia. Sjögren's syndrome is the most common cause of the sicca syndrome; however, these two syndromes are not synonymous and there are many potential etiologies of the sicca syndrome. A less known cause of sicca syndrome is amyloidosis that to date has only been reported in the nondermatology literature. OBSERVATIONS: A 79-year-old man with known amyloidosis presented with persistent xerostomia. He had the classic cutaneous findings of periorbital and "pinch" purpura. A labial biopsy showed diffuse deposition of amorphous eosinophilic material surrounding salivary acini. Apple-green birefringence was noted with Congo red staining and the diagnosis was made of amyloidosis in the minor salivary glands causing xerostomia. CONCLUSIONS: The sicca syndrome can be caused by systemic amyloidosis. Because this fact is not in the dermatologic literature, many dermatologists are not aware of this uncommon presentation. The knowledge of the many causes of the sicca syndrome and an understanding of the differences between this and Sjögren's syndromes are important for any dermatologist.

DOPA-negative melanocytes in the outer root sheath of human hair follicles express premelanosomal antigens but not a melanosomal antigen or the melanosome-associated glycoproteins tyrosinase, TRP-1, and TRP-2.

It is believed that DOPA-negative melanocytes in the outer root sheath of the human hair follicle are activated, become identifiable by DOPA staining, and migrate into the epidermis during the repigmenting phase of vitiligo. These cells are difficult to identify, however, and otherwise have not been characterized. These cells are readily identified by immunofluorescence, immunohistochemistry, and immunoelectronmicroscopy using the antibodies NKI/beteb and A4F11, which recognize premelanosome-related antigens. The majority of the outer root sheath melanocytes were found in the mid to the upper portion of the hair follicle. Double staining revealed that these cells were distinct from HLA-DR-bearing dendritic cells. Further immunohistochemical investigation using alpha-PEP-7, alpha-PEP-1, or TMH-1 and alpha-PEP-8 antibodies revealed that outer root sheath melanocytes cannot be identified by antibodies to tyrosinase, TRP-1, or TRP-2, respectively. These cells also did not react with HMB45 antibody, which recognizes a melanosome-associated cytoplasmic antigen. We believe that the inactive outer root sheath melanocytes contain some of the early structural proteins but not any of the enzymatic proteins necessary for melanogenesis. Therefore, activation is the process whereby outer root sheath melanocytes acquire all of the structural and enzymatic proteins necessary for melanogenesis.

In three types of interface dermatitis, different patterns of expression of intercellular adhesion molecule-1 (ICAM-1) indicate different triggers of disease.

We found distinct patterns of intercellular adhesion molecule-1 (ICAM-1) expression in three diseases characterized by interface dermatitis with mononuclear infiltrates and keratinocyte cytotoxicity: lichen planus (LP), subacute cutaneous lupus erythematosus (SCLE), and erythema multiforme (EM). In LP, basal keratinocytes show strong ICAM-1 expression associated with a dermal infiltrate, but ICAM-1 expression in the rest of the epidermis is minimal. In SCLE, there is diffuse epidermal ICAM-1 expression, sometimes with accentuation on the cell surface of basal cells. In EM, there is strong basal cell expression of ICAM-1 with evident cell surface accentuation, and also pockets of suprabasal expression with cell surface accentuation. These patterns are associated with different factors that trigger cytokine release in different locations. Both tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) produce greater relative ICAM-1 expression in basal keratinocytes than in more differentiated keratinocytes. In LP, the pure basal keratinocyte expression of ICAM-1 appears to be caused by cytokines, predominantly IFN-gamma, released by dermal lymphocytes. The pattern of ICAM-1 in SCLE corresponds to the pattern induced by ultraviolet radiation (UVR): diffuse epidermal ICAM-1 expression, sometimes with basal accentuation. Some individuals are "responders" to TNF-alpha or UVR, showing high levels of ICAM-1 expression following UVR or TNF-alpha stimulation in vitro or UVR stimulation in vivo. We propose that the pattern of ICAM-1 induction in SCLE is dependent on UVR-induced TNF-alpha release. EM is associated with apparent latent Herpes simplex virus, and Herpes simplex virus (HSV)-infected keratinocytes show enhanced ICAM-1 expression. We propose that in EM suprabasal ICAM-1 expression may be induced directly by HSV infection or indirectly through TNF-alpha release induced by HSV reactivation. Induction of ICAM-1 within the epidermis is stratified and individually variable. Basal keratinocytes show maximal induction of ICAM-1 expression due to innate sensitivity to TNF and IFN-gamma stimulation, and to location adjacent to dermal sources of cytokines. Suprabasal ICAM-1 can be induced by UVR and epidermal TNF-alpha release, and by factors such as viral infection. Different triggers of cytokine release and adhesion molecule induction may influence the different patterns of inflammation seen in diverse inflammatory skin diseases.

Palmar purpura: an atypical presentation of childhood dermatitis herpetiformis.

Dermatitis herpetiformis (DH) is seen most commonly as a pruritic, papulovesicular eruption in young children or adolescents. Differentiation from other bullous diseases of childhood may be difficult. We report the first case of an adolescent in whom pruritic, palmar, purpuric macules and papules were the only manifestations of DH. The patient later developed typical vesiculobullous extensor lesions and symptomatic gluten-sensitive enteropathy (GSE). All lesions and GSE symptoms resolved with dapsone and a gluten-free diet. Our purpose is to illustrate an unusual presentation of pediatric DH.

Clinical, histologic, and immunofluorescent distinctions between subacute cutaneous lupus erythematosus and discoid lupus erythematosus.

Subacute cutaneous lupus erythematosus (SCLE) was originally described and distinguished from discoid lupus erythematosus (DLE) on the basis of clinical examination of the skin, but subsequent reports have questioned the concept of SCLE as a marker of a unique subset of LE patients. We classified 27 lupus patients, on the basis of cutaneous exam, as having discoid lupus skin lesions, subacute cutaneous skin lesions, or systemic lupus erythematosus (SLE) without DLE or SCLE lesions. Clinical features most characteristic of SCLE rather than DLE were superficial, non-indurated, non-scarring lesions, and photosensitivity, with lack of induration being the single most helpful finding. Histologic examination of lesional skin showed a relatively sparse, superficial infiltrate in SCLE and a denser, deeper infiltrate in DLE. A distinctive pattern of staining with direct immunofluorescence, particulate epidermal IgG deposition, was found in seven of seven SCLE patients (all anti-Ro/SSA positive) and none of the other patients. This distinctive pattern can be reproduced experimentally when anti-Ro/SSA autoantibodies are infused into human skin-grafted mice. Particulate dermal-epidermal junctional staining was the pattern seen in the patients who did not have SCLE. Clinically defining SCLE as a superficial inflammatory form of cutaneous lupus (i.e., considering lesions to be DLE if they are indurated) results in a meaningful segregation of SCLE and DLE patient groups. The epidermal IgG deposits unique to SCLE provide independent evidence that the clinical findings that were used to identify the patient groups actually identify distinctive cutaneous lupus subsets. The observation that antibodies are present in a different location in the skin in SCLE than in DLE indicates that SCLE and DLE are likely to have different pathomechanisms.

Our Achilles heel.

In spite of major improvements in the quality of the medical care given by the Military Medical Services, there exists an area which has been neglected. The practice of assigning young unseasoned physicians to small health facilities, which are often isolated, has led to a situation which places the high quality of military medical care in jeopardy. Recognition of the problem is long overdue and threatens to undermine patient care in the military system. Probably the most difficult hurdle will be to developing an awareness of this problem and, once this is overcome, there are several simple steps which could quickly be instituted to correct the situation.

IgG subclasses in the serum and skin in subacute cutaneous lupus erythematosus and neonatal lupus erythematosus.

IgG subclasses differ in their biologic and chemical properties, such as complement fixation, protein and cellular binding, and placental transfer. In this study, IgG subclasses of anti-Ro/SSA antibodies in subacute cutaneous lupus (SCLE) and neonatal lupus (NLE) are examined in the serum and in the skin. IgG subclasses in NLE beginning in utero (NLE-heart disease) are compared to subclasses in NLE beginning after birth (NLE-skin disease). Human skin was grafted onto athymic mice, mice were injected with one of eight anti-Ro/SSA maternal NLE sera (four heart block, four skin disease) or seven anti-Ro/SSA SCLE sera, and grafts were examined for IgG subclasses using monoclonal anti-human IgG subclass reagents in an immunofluorescent technique. Lesional skin was examined from four SCLE patients. IgG1 was the only IgG subclass detected in the grafts and skin lesions. IgG1 was the predominant anti-Ro/SSA IgG subclass detected in SCLE and NLE sera in an ELISA using a synthetic Ro/SSA polypeptide. These studies show that the maternal anti-Ro/SSA autoantibodies in NLE-heart disease sera are predominantly IgG1 and are therefore likely to be present in the fetus at the time of gestation, when heart block usually develops. Second, differences in the clinical presentations of NLE (in utero vs. postnatal disease) cannot be attributed to differences in anti-Ro/SSA IgG subclasses. Finally, the subclass bound in the skin in SCLE is IgG1, a subclass capable of mediating tissue injury via complement or cellular effectors.

Monitoring and evaluation in an Army health clinic.

In 1987, the authors implemented an indicator monitoring system that allows for ongoing evaluation of important aspects of care at the Erlangen Health Clinic, Erlangen, Federal Republic of Germany, a U.S. Army primary medical clinic serving approximately 1,200 patients a month. Staff developed prospective and retrospective indicators based on identified high-risk, high-volume areas, and established thresholds of evaluation for each of the indicators. A numerical auditing mechanism is used to record compliance with established objective criteria that determine whether or not a case is deficient. A peer review committee reviews and recommends actions for deficient cases.

Hydroa vacciniforme with inflammatory keratitis and secondary anterior uveitis.

A 6-year-old boy had numerous episodes of hydroa vacciniforme. Several of these episodes were accompanied by an anterior uveitis with corneal clouding and stellate keratic precipitates. Wearing sunglasses prevented new eye lesions from developing despite recurrences of skin lesions. Phototesting on facial skin revealed reproduction of skin lesions with ultraviolet B but not ultraviolet A. One should be aware of eye involvement in hydroa vacciniforme, and children who experience this form of photodermatitis should have a careful eye examination and be advised to wear protective sunglasses.

Neutrophilic eccrine hidradenitis associated with induction chemotherapy.

We report three new cases of neutrophilic eccrine hidradenitis associated with induction chemotherapy which resolves two major points. First, because two of our patients had testicular carcinoma; this firmly establishes that NEH is not exclusively seen in patients with acute myelogenous leukemia or Hodgkin's lymphoma as previously reported. Second, because two of our patients did not receive cytarabine which has previously been suspected of being the causative agent, it is apparent that this disorder may be produced by more than one chemotherapeutic agent or combination of agents. The histologic features with a discussion of the spectrum of changes which may be seen are presented.