The subcutaneous pedicle flap in melolabial reconstruction.

OBJECTIVE: To review and report our experience with the subcutaneous pedicle flap in the reconstruction of defects adjacent to the melolabial crease. DESIGN: Retrospective review. SETTING: Cutaneous surgery unit of an academic tertiary referral center. PATIENTS: One hundred nine patients with defects of the lateral aspect of the upper lip, the medial aspect of the cheek, and the melolabial crease after Moh excision of cutaneous lesions. CONCLUSIONS: In our experience, the subcutaneous pedicle advancement flap is often ideally suited to the reconstruction of cutaneous defects adjacent to the melolabial crease. We have been particularly satisfied with the results of this reconstructive technique when addressing deep defects adjoining the alar facial sulcus in patients with full cheeks.

Squamous cell metaplasia in the human lung: molecular characteristics of epithelial stratification.

Squamous cell metaplasia (SCM) is a frequent epithelial alteration of the human tracheobronchial mucosa. This review pays particular attention to the fact that SCM can mimic esophageal, and in some instances even skin-type differentiation, showing striking similarities not only in morphology but also in terms of gene expression. Therefore, characterization of this dynamic process lends insight into the process of stratification, squamous cell formation, and "keratinization" in a pathologically relevant in vivo situation in man. First, the concept of metaplasia is presented with certain historical viewpoints on histogenesis. Then, the morphological characteristics of normal bronchial epithelium are compared with the altered phenotype of cells in SCM. These changes are described as a disturbance of the finely tuned balance of differentiation and proliferation through the action of a variety of extrinsic and intrinsic factors. Molecular aspects of altered cell/cell and cell/extracellular matrix interactions in stratified compared with single-layered epithelia are discussed with reference to SCM in the lung. Intracellular organizational and compositional changes are then summarized with special emphasis on the differential distribution of the cytokeratin (CK) polypeptides. Finally, the still unresolved problems of the histogenetic relationships between normal bronchial mucosa, SCM, and pulmonary neoplasms are addressed. As these questions remain open, examples for detection of well defined "markers" are provided that may be employed as objective criteria for determining clinically important cellular differentiation features.

Synthesis of a naphthylvinyl-labeled glycerol ether analog of phosphatidylcholine and its use in the assay of phospholipase A2.

The synthesis of a naphthylvinyl-labeled glycerol ether analog of phosphatidylcholine, 1-O-[12-(2-naphthyl)-dodec-11-enyl]-2-O-decanoyl-sn-glycerol-3- phosphocholine (NVPC), is described. This involves a Wittig reaction between 2-naphthaldehyde and a phosphonium salt which gives the trans-naphthylvinyl group as the predominant isomer. Lyso NVPC was prepared from NVPC by phospholipase A2 action. NVPC absorbs strongly at 248 nm (epsilon = 58,300 M-1 cm-1) and gives broad fluorescence emission with maxima at 343 nm and 360 nm and a quantum yield of 0.10 in ethanol. An assay for phospholipase A2 was developed using high performance liquid chromatography with fluorescence detection to separate and quantify NVPC and lyso NVPC. Activities as low as 1-2 pmol/min in an assay volume of 0.1 ml can easily be measured. The assay was used with a pure enzyme from cobra venom and a crude enzyme from synovial fluid. Enzyme specificities for phosphatidylcholine and NVPC with cobra venom and porcine pancreatic phospholipases A2 were compared using a titrametric assay. The use of the assay with NVPC to study the metabolism of platelet activating factor is discussed.