Fibroblasts can condense a hydrated collagen lattice to a tissue-like structure 1/28th the area of the starting gel in 24 hr. The rate of the process can be regulated by varying the protein content of the lattice, the cell number, or the con- centration of an inhibitor such as Colcemid. Fibroblasts of high population doubling level propagated in vitro, which have left the cell cycle, can carry out the contraction at least as efficiently as cycling cells. The potential uses of the system as an immu- nologically tolerated "tissue" for wound hea ing and as a model for studying fibroblast function are discussed.

Production of a tissue-like structure by contraction of collagen lattices by human fibroblasts of different proliferative

c-myc, N-myc and L-myc are the three members of the myc oncoprotein family whose role in the pathogenesis of many human neoplastic diseases has received wide empirical support. In this review, we first summarize data, derived mainly from non-clinical studies, indicating that these oncoproteins actually serve quite different roles in vivo. This concept necessarily lies at the heart of the basis for the observation that the deregulated expression of each MYC gene is reproducibly associated with only certain naturally occurring malignancies in humans and that these genes are not interchangeable with respect to their aberrant functional consequences. We also review evidence implicating each of the above MYC genes in specific neoplastic diseases and have attempted to identify unresolved questions which deserve further basic or clinical investigation. We have made every attempt to review those diseases for which significant and confirmatory evidence, based on studies with primary tumor material, exists to implicate MYC members in their causation and/or progression.

MYC oncogenes and human neoplastic disease

The extracellular matrix as a biologic scaffold material.

Situations where normal autografts cannot be used to replace damaged skin often lead to a greater risk of mortality, prolonged hospital stay and increased expenditure for the National Health Service. There is a substantial need for tissue-engineered skin bioconstructs and research is active in this field. Significant progress has been made over the years in the development and clinical use of bioengineered components of the various skin layers. Off-the-shelf availability of such constructs, or production of sufficient quantities of biological materials to aid rapid wound closure, are often the only means to help patients with major skin loss. The aim of this review is to describe those materials already commercially available for clinical use as well as to give a short insight to those under development. It seeks to provide skin scientists/tissue engineers with the information required to not only develop in vitro models of skin, but to move closer to achieving the ultimate goal of an off-the-shelf, complete full-thickness skin replacement.

https://royalsocietypublishing.org/doi/pdf/10.1098/rsif.2009.0403

A review of tissue-engineered skin bioconstructs available for skin reconstruction

&NA; This study evaluates the feasibility of growing tissue‐engineered cartilage in the shape of a human ear using chondrocytes seeded onto a synthetic biodegradable polymer fashioned in the shape of a 3‐year‐old child's auricle. A polymer template was formed in the shape of a human auricle using a nonwoven mesh of polyglycolic acid molded after being immersed in a 1% solution of polylactic acid. Each polyglycolic acid‐polylactic acid template was seeded with chondrocytes isolated from bovine articular cartilage and then implanted into subcutaneous pockets on the dorsa of 10 athymic mice. The three‐dimensional structure was well maintained after removal of an external stent that had been applied for 4 weeks. Specimens harvested 12 weeks after implantation and subjected to gross morphologic and histologic analysis demonstrated new cartilage formation. The overall geometry of the experimental specimens closely resembled the complex structure of the child's auricle. These findings demonstrate that polyglycolic acid‐polylactic acid constructs can be fabricated in a very intricate configuration and seeded with chondrocytes to generate new cartilage that would be useful in plastic and reconstructive surgery. (Plast. Reconstr. Surg. 100: 297, 1997.)

Transplantation of chondrocytes utilizing a polymer-cell construct to produce tissue-engineered cartilage in the shape of a human ear

https://www.healthmegamall.com/Articles/BabeskinArticle51.pdf

Sunscreens Inadequately Protect Against Ultraviolet-A-Induced Free Radicals in Skin: Implications for Skin Aging and Melanoma?

https://www.jprasurg.com/article/S0007-1226(04)00380-7/pdf

Histological evaluation of Permacol as a subcutaneous implant over a 20-week period in the rat model.

This paper examines the psychological and social impact of reconstructive surgery for hemi-facial palsy and considers psychosocial factors which may be associated with patient satisfaction. It reports a retrospective study in which 106 adults were assessed using primarily qualitative methods. All participants had undergone two-stage reconstruction using vascularised free muscle grafts, with all procedures having been carried out by the same surgeon. The participants were all at least 12 months post-surgery. They were assessed using demographic questionnaires, the hospital anxiety and depression scale (HADS) and the facial paralysis evaluation measure (FPEM). In addition, all participants were interviewed using a semi-structured format, the interviews were recorded verbatim and the transcripts were analysed using thematic analysis. Of the total study group, 67% had acquired facial palsy. The mean age of the total group was 44.7 years and 67.9% were female. As a group they were rather less depressed than the normal population with similar levels of anxiety to population norms. The primary motivation for surgery was appearance rather than function. Using interview data in addition to the FPEM, satisfaction with the process and outcome of surgery was assessed. Thirty five percent were very satisfied with both process and outcome, 34% were satisfied with the outcome but found the treatment process stressful, 15.1% were not entirely satisfied with process or outcome but felt surgery had been worthwhile as there had been some improvement. The remainder were very dissatisfied with both process and outcome and regretted having undergone surgery. There was no significant association between dissatisfaction and anxiety, the cause of the acquired palsy, longevity prior to surgery, gender nor whether the condition was acquired or congenital. There was a significant relationship with depression, in that those who were suffering from depression were more likely to be dissatisfied with surgery. Participants were asked in interview about social pressures and comments or remarks made by others about their condition. The majority (89.6%) of the total study group reported intrusive questions by acquaintances and strangers, with more than half of these being distressed by such questions. Following surgery, there was a significant reduction in the incidence of these questions. There was no relationship between distress in response to these questions prior to surgery and dissatisfaction with surgery. However, 27.4% also reported aggressive hurtful comments before surgery with a minimal improvement in incidence following surgery. These participants also reported consistent patterns of social avoidance and social isolation before and after surgery, and were more likely to be depressed than the rest of the study group. They were significantly more likely to be dissatisfied with surgery (p=.016). It is recommended that patients are screened and counseled prior to surgery to identify such problems and referred for psychological treatment in order to ensure they gain maximum benefit from reconstructive surgery.

https://www.jprasurg.com/article/S0007-1226(05)00310-3/pdf

Psychological and social factors in reconstructive surgery for hemi-facial palsy.

https://www.jprasurg.com/article/0007-1226(83)90100-5/pdf

The medicinal leech and its use in plastic surgery: a possible cause for infection

Background : Keratinocyte grafting can be used to treat acute traumatic and chronic non-healing wounds. The keratinocyte sheets are fragile and clinical “take” is difficult to assess, especially as activated keratinocytes secrete many growth factors, which have effects on wound healing apart from take. We have developed animal models of grafting that allow us to examine factors influencing autologous keratinocyte graft take. Results show clearly that pretreatment of the wound bed with viable dermis greatly increases the take of keratinocyte grafts. Data sources : International literature. Conclusions : As a greater understanding of the complex interactions of cell and matrix evolve, so will potential therapeutic maneuvers, not just in the field of cultured keratinocyte grafts, but clearly in that of benign tumors, for example, keloids, and that of oncology. There is now overwhelming evidence of the requirement for a dermal substitute for cultured keratinocyte autografts, and the sheer complexity of the situation demands that this should approximate live human dermis as closely as possible. The stumbling blocks relate to avoiding the risks of viral transmission, tissue matching of host and donor, providing early epithelial cover, and improving delivery systems for fragile keratinocyte grafts.

Roy Sanders

Papers

Sunscreens Inadequately Protect Against Ultraviolet-A-Induced Free Radicals in Skin: Implications for Skin Aging and Melanoma?

Histological evaluation of Permacol as a subcutaneous implant over a 20-week period in the rat model.

Psychological and social factors in reconstructive surgery for hemi-facial palsy.

The medicinal leech and its use in plastic surgery: a possible cause for infection

Transplantation of keratinocytes in the treatment of wounds.