Cutaneous signs of systemic disease.

Commonly used dermatologic eponyms and characteristic skin signs are enormously helpful in guiding a diagnosis, even though they may not be pathonemonic. They include, on the nails, Aldrich-Mees' lines (syn.: Mees' lines), Beau's lines, Muehrcke's lines, Terry's nails, and half and half nails, often associated, respectively, with arsenic poisoning, acute stress or systemic illness, severe hypertension, liver disease and uremia, and, around the nails, Braverman's sign, associated with collagen-vascular disease. Elsewhere, one may see the Asboe-Hansen and Nikolsky's signs, indicative of the pemphigus group of diseases, Auspitz's sign, a classic finding in psoriasis, Borsieri's and Pasita's signs, seen in early scarlet fever, the butterfly rash, indicative of systemic lupus erythematosus, and the buffalo hump, seen in Cushing's disease and also in the more common corticosteroid toxicity. Gottron's papules and the heliotrope rash are signs of dermatomyositis. Janeway's lesions and Osler's nodes are seen in bacterial endocarditis. A Dennie-Morgan fold under the eye is seen in association with atopic disease. Koplik's spots are an early sign of rubeola. Fitzpatrick's sign is indicative of a benign lesion (dermatofibroma), whereas Hutchinson's sign is indicative of a malignant one (subungual melanoma). Petechiae are seen in many diseases, including fat embolization, particularly from a large bone fracture following trauma. Palpable purpura is indicative of leukocytoclastic vasculitis, and is an early, critical sign in Rickettsial diseases, including Rocky Mountain Spotted Fever, which must be diagnosed and treated early. Hyperpigmentation of areolae and scars is seen in Addison's disease. Acanthosis nigricans may indicate internal cancer, especially stomach cancer, whereas Bazex's syndrome occurs in synchrony with primary, usually squamous cancer, in the upper aerodigestive tract or metastatic cancer in cervical lymph nodes. Perioral pigmented macules or one or more cutaneous sebaceous neoplasms may be a sign of the Peutz-Jeghers or Muir-Torre syndrome, respectively, both associated also with intestinal polyps that have a malignant potential. Telangiectasiae in the perioral region may be associated with similar lesions internally in Osler-Weber-Rendu disease. Kerr's sign is indicative of spinal cord injury and Darier's sign of mastocytosis. Post proctoscopic periobital purpura (PPPP) is a phenomenon observed in some patients with systemic amyloidosis. Koebner's isomorphic response refers to the tendency of an established dermatosis, such as psoriasis, to arise in (a) site(s) of trauma, whereas Wolf's isotrophic response refers to a new dermatosis, such as tinea, not yet seen in the patient, arising in (a) site(s) of a former but different dermatosis, such as zoster.

Arcuate, annular, and polycyclic inflammatory and infectious lesions.

Common shapes encountered in dermatologic diseases include linear, nummular, annular, polycyclic, and arciform. The last three have a relatively restricted differential, which must be entirely explored. It is not uncommon for a single disease to present in annular, arciform or polycyclic configurations; moreover, the lesions may evolve from being arciform to annular and then become polycyclic. Regardless, recognizing the arrangement of the defect will undoubtedly help in making a diagnosis and guiding subsequent management. We explore diseases that often present in annular, arciform, and/or polycyclic forms.

Targeting the PI3K and MAPK pathways to treat Kaposi's-sarcoma-associated herpes virus infection and pathogenesis.

Cells require the ability to appropriately respond to signals in their extracellular environment. To initiate, inhibit and control these processes, the cell has developed a complex network of signaling cascades. The phosphatidylinositol 3-kinase (PI3K) and mitogen-activated protein kinase (MAPK) signaling pathways regulate several responses including mitosis, apoptosis, motility, proliferation, differentiation and many others. It is not surprising, therefore, that many viruses target the PI3K and MAPK pathways as a means to manipulate cellular function. Recently, Kaposi's sarcoma-associated herpes virus (KSHV) has been added to the list. KSHV manipulates the PI3K and MAPK pathways to control such divergent processes as cell survival, cellular migration, immune responses, and to control its own reactivation and lytic replication. Manipulation of the PI3K and MAPK pathways also plays a role in malignant transformation. Here, the authors review the potential to target the PI3K and MAPK signaling pathways to inhibit KSHV infection and pathogenesis.

Beta1 integrins mediate tubule formation induced by supernatants derived from KSHV-infected cells.

OBJECTIVE: Angiogenesis is defined as the formation of new blood vessels. In a recently concluded study, we identified Kaposi's sarcoma-associated herpesvirus (KSHV)-infected cells derived from primary effusion lymphoma (PEL) to overexpress vascular endothelial growth factor (VEGF) that had the propensity to mediate tubule formation on a Matrigel, an indicator of angiogenesis. The objective of this study was to determine the receptor molecules that mediate the tubule formation induced by the supernatant derived from KSHV-infected PEL cells. METHODS: The identity of receptor(s) that play a role in mediating tubule formation driven by PEL supernatant was determined by the classical in vitro angiogenesis assay conducted on a Matrigel. RESULTS: RGD peptides, antibodies, and siRNA specific to beta1 integrins significantly lowered the ability of the PEL supernatants to induce tubule formation by endothelial cells. beta1 Integrins mediated tubule formation to comparable levels in endothelial cells that were incubated with supernatants derived from uninduced or TPA-induced PEL cells. Interestingly, the beta1 integrins did not seem to have a major role in cellular attachment. CONCLUSION: We report for the first time a critical role for beta1 integrins in angiogenesis supported by the supernatant from KSHV-infected PEL cells.

Changes occurring on the cell surface during KSHV reactivation.

Following an infection, Kaposi's sarcoma-associated herpes virus (KSHV) exists predominantly in its latent state, with only 1-2% of infected cells undergoing lytic reactivation. We have previously demonstrated along with others a relationship between lytic reactivation and cell cycle progression (Bryan et al., 2006. J. Gen. Virol. 87: 519; McAllister et al., 2005. J. Virol. 79: 2626). Infected cells in the S phase are much more likely to undergo lytic reactivation when compared to those in G(0)/G(1) phase. Through the use of scanning electron microscopy (SEM), we analyzed changes occurring on the surface of cells undergoing KSHV reactivation. KSHV reactivation was observed predominantly in cells with smoother surface topology; a hallmark of cells derived from S phase. Interestingly, during the late stages of the reactivation process, we observed KSHV particles to egress cells through budding. Taken together, based on scanning electron microscopy and transmission electron microscopy evidences, we demonstrate for the first time the existence of a direct link between cell surface topology, cell cycle progression and KSHV reactivation.