Skin expansion in burn patients: problems, rules and indications

Skin expansion in burn patients can be a useful method for secondary skin resurfacing, scar revision or facial remodelling. However, complications and problems occur more often in these patients than in any other. In this paper the incidence of complication in the first and second stages of expansion will be presented. Several rules will then be stated and we will clarify the indications for skin expansion in the treatment of hypertrophic scars, contractures, and post-burn destructions.Lecture given at the first State of the art course on burn reconstruction — Milano, May 1994     

Staged TRAM Breast Reconstruction: Combining the Advantages of Tissue Expansion with Surgical Delay

The TRAM flap has become the gold standard in breast reconstruction but suffers from the disadvantages of poor color match, different texture, and impaired sensation compared to the normal breast. This study reports on a two-stage procedure to address these problems. The first stage consists of insertion of a tissue expander and surgical delay of the TRAM flap. The second stage consists of removal of the tissue expander and transposition of a deepithelized TRAM flap into the tissue expanded cavity. (The capsule is excised.) Four cases of breast reconstruction are reported. The advantage of this procedure is that it offers the benefits of tissue expansion, viz., normal color match, texture, and sensation, and in addition, reconstruction is achieved with autologous tissue by a pedicled TRAM flap. The vascularity of the TRAM is enhanced by a surgical delay procedure.     

Labial skin-flap vaginoplasty using tissue expanders

In severe vaginal malformations, when the distance between the upper vaginal pouch and perineum is too long (6 cm or more), reconstruction of the vagina can be performed by colonic interposition or by long cutaneous flaps obtained by the tissue expansion technique. Two female adolescents were treated using expanded labial skin flaps. Dissection and anastomosis between the vaginal remnant and cutaneous tube was performed by the transtrigonal approach. Results were satisfactory at 2.5-year follow-up. In our opinion, expanded labial skin-flap vaginoplasty has three main advantages: (1) it permits the construction of a large, soft, well-vascularized neovagina using non-hair-bearing labial skin; (2) it obviates postoperative dilations and prevents delayed strictures; and (3) a transtrigonal approach permits an easy vaginal dissection and a careful, tension-free anastomosis.     

软组织扩张术后皮肤组织形态计量学改变

本文对６例额部皮肤软组织扩张术后皮瓣和８例正常人额部皮肤组织进行形态计量学分析及超微结构观察，探讨软组织扩张后“额外”皮肤组织的来源及形态计量学指标的改变。结果表明，扩张后表皮层数、表皮细胞面积及表皮、真皮厚度的检测值均明显高于正常对照组（Ｐ＜０．０１），而且真皮内血管数目增多。提示，软组织扩张后，表皮细胞增殖及真皮内胶原纤维合成增加是“额外”皮肤来源的形态学基础。     

Chest wall deformity after tissue expansion

There have been few reports about skeletal changes beneath a tissue expander in breast reconstruction. We present one, and surgeons should be cautious about the possibility of skeletal deformities in patients who are osteoporotic and postmenopausal who require prolonged tissue expansion.     

Tissue‐specific and time‐dependent clonal expansion of ENU‐induced mutant cells in gpt delta mice

DNA mutations play a crucial role in the origins of cancer, and the clonal expansion of mutant cells is one of the fundamental steps in multistage carcinogenesis. In this study, we correlated tumor incidence in B6C3F1 mice during the period after exposure to N ‐ ethyl‐N‐nitrosourea (ENU) with the persistence of ENU‐induced mutant clones in transgenic gpt delta B6C3F1 mice. The induced gpt mutations afforded no selective advantage in the mouse cells and could be distinguished by a mutational spectrum that is characteristic of ENU treatment. The gpt mutations were passengers of the mutant cell of origin and its daughter cells and thus could be used as neutral markers of clones that arose and persisted in the tissues. Female B6C3F1 mice exposed for 1 month to 200 ppm ENU in the drinking water developed early thymic lymphomas and late liver and lung tumors. To assay gpt mutations, we sampled the thymus, liver, lung, and small intestine of female gpt delta mice at 3 days, 4 weeks, and 8 weeks after the end of ENU exposure. Our results reveal that, in all four tissues, the ENU‐induced gpt mutations persisted for weeks after the end of mutagen exposure. Clonal expansion of mutant cells was observed in the thymus and small intestine, with the thymus showing larger clone sizes. These results indicate that the clearance of mutant cells and the potential for clonal expansion during normal tissue growth depends on tissue type and that these factors may affect the sensitivity of different tissues to carcinogenesis. Environ. Mol. Mutagen. 58:592–606, 2017. © 2017 Wiley Periodicals, Inc.     

Potential pathogenic mechanisms underlying Fragile X Tremor Ataxia Syndrome: RAN translation and/or RNA gain-of-function?

Fragile X-associated tremor/ataxia syndrome (FXTAS) is an inherited neurodegenerative disease caused by an expansion of 55–200 CGG repeats located in the FMR1 gene. The main clinical and neuropathological features of FXTAS are progressive intention tremor and gait ataxia associated with brain atrophy, neuronal cell loss and presence of ubiquitin-positive intranuclear inclusions in both neurons and astrocytes. At the molecular level, FXTAS is characterized by increased expression of FMR1 sense and antisense RNA containing expanded CGG or GGC repeats, respectively. Here, we discuss the putative molecular mechanisms underlying FXTAS and notably recent reports that expanded CGG and GGC repeats may be pathogenic through RAN translation into toxic proteins.