The effects of prestaglandin Ea o the synthesis of type I collagenase mRNA of cultured fibroblasts from hypertrophic scar and keloid

To investigate the effects of prostaglandin E1(PGX1) in prevention of proliferative scar formation, we cultured fibroblasts of normal skin (NS), hypertrophic scar (HS) and keloid (KL) tissues obtained from patients. We have compared type I collagenase production of cultured fibroblasts from normal skin, hypertrophic scar, and keloid tissues under various concentrations of PGE1. Our results demonstrate that type I collagenase production was significantly increased after addition of PGE1 in HS and KL, but not NS. Type I collagenase production of HS and KL fibroblasts were increased similarly in 10M and 10M of PGE1 and maximally increased in the concentration of 10M. This promotive effects of PGE1 on the production of type I collagenase was larger in KL than in HS. These results also suggest that PGE1 may play the promotive effects on type I collagenase production in dose-dependent manner. PGE1 may have a role in the prevention of hypertrophic scar and keloid by enhancing the production of type I collagenase of HS and KL fibroblasts. The promotive effects of PGE1 on type I collagenase production was variable depending on its concentration, and its effects was maximum in certain optimal condition. The maximally effective concentration of PGE1 in the prevention of proliferative scar formation should be searched in further investigations for clinical use.

Mass of Sacrococcygeal Region in Adults

Although sacrococcygeal mass is rare and usually found in infants or children, adolescent or adult patients with protruding mass in sacrococcygeal region occasionally come to us simply for a cosmetic problem. In this situation, even though there is no definite neurological deficit, it should be evaluated whether or not the underlying bony pathology or dural defect exists. Few cases about the sacrococcygeal mass have been reported in adults. We reviewed our cases including preoperative evaluation methods and postoperative diagnosis. From March, 1993 to February, 1997, we experienced 6 adult patients with sacrococcygeal mass and no neurological abnormality. Preoperative evaluation were made by plain X-ray, myelogram, computed tomography(CT), and magnetic resonance imaging (MRI), as needed. Postoperative diagnoses were 2 meningoceles, 2 lipomyelomeningoceles, 1 desmoid tumor, and 1 teratoma. From our experiences, CT or MRI is essential to evaluate the sacrococcygeal mass preoperatively. These methods can visualize the precise anatomic location and extent of the mass, its relation to the spinal cord, and associated bony abnormalities. MRI is superior to CT, especially in defining the nature of the mass and involvement of the spinal cord. Conclusively, even a simple mass in the sacrococcygeal region in adults needs MRI or CT evaluation, and MRI is the most valuable method of evaluating the mass preoperatively and provides important information to establish a treatment plan.

A New Animal Model of Proliferative Scarring

Proliferative scarring in the form of keloids and hypertrophic scars continues to be a clinical problem for some patients. The lack of an animal model for such scarring has been an obstacle to studying the biology and effective therapy of these entities. Consequently we created an accurate reproductive animal model to systematically study them. Human proliferative scars were explanted into flaps based on isolated vascular pedicles in congenitally rats. We compared the procollagen type III peptide levels of proliferative scar tissue before and after explanting. The procollagen type III peptide levels of explanted proliferative scar tissue remained increased as before explanting. Histological analysis of the explanted proliferative scar tissue revealed that all explants retained their original histotypic character even after 1 year. We could also retain the volume of implanted proliferative scar for 1 year and studied in vitro cellular proliferation. Fibroblast cultures from explanted scars demonstrated less aggressive growth characteristic than those from original surgical specimens. The advantages of this animal model are as follows: 1. The explants retain their histotypical character for a long period. 2. Placement of the explants outside the dorsum of a nude rat makes serial observation and measurement easier. 3. Agents under test can be injected into the explants through a catheter inserted into a single pedicle of island flap without the possibility of spreading systematically.