Tetracyclines: nonantibiotic properties and their clinical implications.

Tetracyclines are broad-spectrum antibiotics that act as such at the ribosomal level where they interfere with protein synthesis. They were first widely prescribed by dermatologists in the early 1950s when it was discovered that they were effective as a treatment for acne. More recently, biologic actions affecting inflammation, proteolysis, angiogenesis, apoptosis, metal chelation, ionophoresis, and bone metabolism have been researched.

Treatment of scleroderma.

The treatment of systemic sclerosis (scleroderma) is difficult and remains a great challenge to the clinician. Because the cause is unknown, therapies are directed to improve peripheral blood circulation with vasodilators and antiplatelet aggregation drugs, to prevent the synthesis and release of harmful cytokines with immunosuppressant drugs, and to inhibit or reduce fibrosis with agents that reduce collagen synthesis or enhance collagenase production. The purpose of this review is to critically analyze conventional and new treatments of systemic sclerosis and localized scleroderma.

Immunopathogenesis of scleroderma--evolving concepts.

Scleroderma, or systemic sclerosis, is a connective tissue disease which may affect various organ systems including skin, lungs, gastrointestinal tract, cardiovascular system and kidneys. While the etiology is not clear, it is currently believed that scleroderma may represent an autoimmune response to an unknown antigen. In this regard, there is evidence that both humoral and cellular immunity may play roles.

Altered expression of angiopoietins and Tie2 endothelium receptor in psoriasis.

Psoriasis is a chronic inflammatory skin disease in which epidermal proliferation is closely associated with excessive microvascular expansion within the papillary dermis. Angiopoietins have recently been identified as the major ligands of the endothelial- specific receptor Tie2. Angiopoietin 1 induces Tie2 signaling as a receptor activator and maintains blood vessel formation, whereas angiopoietin 2 destabilizes vessels by blocking Tie2 signaling as an antagonist of angiopoietin 1 and acts with vascular endothelial growth factor to initiate angiogenesis.

Differential expression of laminin alpha chains during proliferative and differentiation stages in a model for skin morphogenesis.

The purpose of this study was to determine the mRNA and protein expression of laminin alpha chains at various stages of in vitro skin morphogenesis. Fibroblasts in mono-cultures express low levels of the mRNA of laminin alpha1,alpha2, alpha3 and alpha4 chains. When co-cultured with keratinocytes for 28 days, they expressed the mRNA for all these chains.