ABSTRACT
UV exposure has been linked to skin cancer in humans by epidemiology and the rare genetic disease xeroderma pigmentosum. However, UV produces multiple photoproducts in DNA, and their relative contribution is uncertain. An enzyme which specifically repairs cyclobutane pyrimidine dimers in DNA, T4 endonuclease V, was encapsulated in liposomes for topical delivery into mouse and human skin. In both species, liposomes applied after UV exposure localized in the epidermis and stimulated the removal of cyclobutane pyrimidine dimers. UV-irradiated mice treated with these liposomes had a dose-dependent decrease in the incidence of squamous cell carcinoma compared to controls. The results demonstrate that unrepaired cyclobutane pyrimidine dimers in DNA are a direct cause of cancer in mammalian skin.
Subject(s)
DNA Repair , Endodeoxyribonucleases/administration & dosage , Endodeoxyribonucleases/therapeutic use , Neoplasms, Radiation-Induced/prevention & control , Skin Neoplasms/prevention & control , Skin/radiation effects , Ultraviolet Rays , Viral Proteins , Animals , DNA Damage , Deoxyribonuclease (Pyrimidine Dimer) , Drug Carriers , Endodeoxyribonucleases/pharmacokinetics , Female , Humans , Liposomes , Mice , Mice, Hairless , Neoplasms, Radiation-Induced/etiology , Organ Culture Techniques , Pyrimidine Dimers/analysis , Skin/pathology , Skin Neoplasms/etiology , T-Phages/enzymology , Tissue DistributionABSTRACT
Reconstruction of upper lip defects demands careful attention in order to reconstitute both normal function and normal appearance. These defects may involve mucosa, orbicularis oris muscle, skin, vermilion, or any combination of these structures. We will describe five cases in which there were defects created by Mohs micrographic surgery and present the concept of partial-thickness wedge in combination with a flap to repair these wounds.
Subject(s)
Carcinoma, Basal Cell/surgery , Lip Neoplasms/surgery , Lip/surgery , Surgical Flaps/methods , Adult , Aged , Dermatologic Surgical Procedures , Female , Humans , Middle Aged , Mouth Mucosa/surgery , Muscles/surgeryABSTRACT
Epidermal keratinocytes cultured from explants of skin cancer patients, including biopsies from xeroderma pigmentosum patients, were ultraviolet light-irradiated and DNA repair synthesis was measured. Repair capacity was much lower in xeroderma pigmentosum patients than in normal patients. The extent of DNA repair replication did not decline with the age of the normal patient. Treatment with T4N5 liposomes containing a DNA repair enzyme enhanced repair synthesis in both normal and xeroderma pigmentosum keratinocytes in an irradiation- and liposome-dose dependent manner. These results provide no evidence that aging people or skin cancer patients are predisposed to cutaneous malignancy by a DNA repair deficiency, but do demonstrate that T4N5 liposomes enhance DNA repair in the keratinocytes of the susceptible xeroderma pigmentosum and skin cancer population.
Subject(s)
DNA Repair/drug effects , Liposomes/pharmacology , Skin/radiation effects , Adult , Aged , Aged, 80 and over , Female , Humans , Keratinocytes/radiation effects , Male , Middle Aged , Skin Neoplasms/genetics , Ultraviolet Rays , Xeroderma Pigmentosum/geneticsABSTRACT
One may accomplish certain closures without tension or distortion using blunt liposuction cannula dissection with or without suction-assisted lipectomy. If closure cannot be accomplished with adequate undermining and an appropriate flap design, the surgeon may first aspirate fat to allow use of the focally expanded skin over the fat. If still unsuccessful, fibrous neurovascular septae are progressively sacrificed as necessary to allow adequate movement and closure. Preservation of the maximal number of blood vessels and nerves within the flap is a given fact. These techniques provide more rapid and safe methods for elevating flaps with significantly less morbidity than sharp dissection methods alone.
Subject(s)
Lipectomy/methods , Surgery, Plastic , Surgical Flaps , Adipose Tissue/surgery , Humans , Lipectomy/instrumentationABSTRACT
Trichloroacetic acid (TCA) is a deliquescent chemical widely used for a variety of procedures. Stability of various concentrations of TCA in both amber glass and plastic bottles stored under refrigeration and at room temperature was measured at several time points. Extended stability data suggest that TCA potency is stable for 23 weeks and would best be maintained in glass amber bottles stored under refrigeration.
Subject(s)
Trichloroacetic Acid , Drug Stability , Drug Storage , Humans , Time FactorsABSTRACT
When lipomas reach 4 cm or more in size or are multiple, liposuction becomes an excellent alternative to excisional surgery, which is the treatment of choice for small lipomas. Two cases of multiple lipomas treated by liposuction surgery are presented.
Subject(s)
Lipectomy , Lipomatosis/surgery , Skin Neoplasms/surgery , Aged , Arm , Hemangioma/pathology , Humans , Leg , Lipectomy/methods , Lipomatosis/genetics , Lipomatosis/pathology , Male , ThoraxABSTRACT
Acute hepatitis developed in a patient taking etretinate for severe psoriasis. Discontinuation of therapy was followed by progression of the histological changes to chronic active hepatitis, despite improvement of his clinical and laboratory status. This is the third reported case of chronic active hepatitis associated with etretinate therapy, and the second patient in our group of twenty-two etretinate-treated patients with severe psoriasis to develop clinically significant hepatic disease. Immunological evaluation revealed a marked increase in the patient's OKMI-staining population of peripheral mononuclear cells and augmentation of Con A-induced lymphocyte blastogenesis in the presence of etretinate.