Translating the combination of gene therapy and tissue engineering for treating recessive dystrophic epidermolysis bullosa.

The combination of gene therapy and tissue engineering is one of the most promising strategies for the treatment of recessive dystrophic epidermolysis bullosa (RDEB). RDEB is a rare genetic disease characterised by mutations in the COL7A1 gene, encoding type VII collagen (COLVII), which forms anchoring fibrils at the dermal-epidermal junction of the skin. This disease causes severe blistering and only palliative treatments are offered. In this study, the base of a strategy combining gene therapy and a tissue-engineered skin substitute (TES), which would be suitable for the permanent closure of skin wounds, was set-up. As a high transduction efficiency into fibroblasts and/or keratinocytes seems to be a prerequisite for a robust and sustained correction of RDEB, different envelope pseudotyped retroviral vectors and the transduction enhancer EF-C were tested. When green fluorescent protein (GFP) was used as a reporter gene to evaluate the retroviral-mediated gene transfer, the fibroblast infection efficiency was 30 % higher with the Ampho pseudotyped vector as compared with the other pseudotypes. At least a 3.1-fold and a 1.3-fold increased transduction were obtained in fibroblasts and keratinocytes, respectively, with EF-C as compared with polybrene. A continuous and intense deposit of haemagglutinin (HA)-COLVII was observed at the dermal-epidermal junction of self-assembled TESs made of cells transduced with a HA-tagged COL7A1 vector. Furthermore, HA-tagged basal epidermal cells expressing keratin 19 were observed in TESs, suggesting stem cell transduction. This approach could be a valuable therapeutic option to further develop, in order to improve the long-term life quality of RDEB patients.

Autologous bilayered self-assembled skin substitutes (SASSs) as permanent grafts: a case series of 14 severely burned patients indicating clinical effectiveness.

Split-thickness skin autografts (AGs) are the standard surgical treatment for severe burn injuries. However, the treatment of patients with substantial skin loss is limited by the availability of donor sites for skin harvesting. As an alternative to skin autografts, our research group developed autologous self-assembled skin substitutes (SASSs), allowing the replacement of both dermis and epidermis in a single surgical procedure. The aim of the study was to assess the clinical outcome of the SASSs as a permanent coverage for full-thickness burn wounds. Patients were recruited through the Health Canada's Special Access Program. SASSs were grafted on debrided full-thickness wounds according to similar protocols used for AGs. The graft-take and the persistence of the SASS epithelium over time were evaluated. 14 patients received surgical care with SASSs. The mean percentage of the SASS graft-take was 98 % (standard deviation = 5) at 5 to 7 d after surgery. SASS integrity persisted over time (average follow-up time: 3.2 years), without noticeable deficiency in epidermal regeneration. Assessment of scar quality (skin elasticity, erythema, thickness) was performed on a subset of patients. Non-homogeneous pigmentation was noticed in several patients. These results indicated that the SASS allowed the successful coverage of full-thickness burns given its high graft-take, aesthetic outcome equivalent to autografting and the promotion of long-term tissue regeneration. When skin donor sites are in short supply, SASSs could be a valuable alternative to treat patients with full-thickness burns covering more than 50 % of their total body surface area.

Prevalence of risk factors for cardiovascular disease in paramedics.

PURPOSE: Occupational stress and obesity are very prevalent in emergency workers. Some studies have also associated high tobacco consumption rates with occupational stress. Each of these factors is known to increase cardiovascular risk. The aim of this study was to evaluate the prevalence of occupational stress, overweight and tobacco consumption in paramedics. METHODS: This cross-sectional study of paramedics consisted in a self-report survey of 44 questions divided into two sections. The first section collected demographic information and the second evaluated occupational stressors. The questions were designed to determine the prevalence of work-related psychosocial factors, overweight (body mass index ≥ 25 kg/m(2)) and tobacco consumption (cig/day ≥ 1). The demand-control-social support model and the effort-reward model were used to estimate job strain, iso-strain and imbalance in effort and reward. RESULTS: More than 88 % of paramedics reported at least one cardiovascular risk factor, with males reporting more risk factors than females. Ninety percent of male paramedics reported occupational stress, 12 % reported smoking, and 79 % were overweight or obese by self-report. The prevalence of occupational stress and smoking was similar for female paramedics, but with a lower prevalence of overweight (37 %). CONCLUSION: By self-report, nine out of ten paramedics are at risk of developing cardiovascular disease. Both individual and organizational efforts should be made to educate and support paramedics and their organizations in reducing these workers' cardiovascular risk.

Effect of intense pulsed light treatment on human skin in vitro: analysis of immediate effects on dermal papillae and hair follicle stem cells.

BACKGROUND: Hair follicles house a permanent pool of epithelial stem cells. Intense pulsed light (IPL) sources have been successfully used for hair removal, but long-term hair reduction may require several treatments. Many questions remain regarding the impact of IPL treatment on the structure of the hair follicle, more specifically on hair follicular stem cells and dermal papilla cells, a group of specialized cells that orchestrate hair growth. OBJECTIVES: To characterize the destruction of human hair follicles and surrounding tissues following IPL treatment, with more attention paid to the bulge and the bulb regions. METHODS: Human scalp specimens of Fitzpatrick skin phototype II were exposed ex vivo to IPL pulses and were then processed for histological analysis, immunodetection of stem cell-associated keratin 19, and revelation of the endogenous alkaline phosphatase activity expressed in dermal papilla cells. RESULTS: Histological analysis confirmed that pigmented structures, such as the melanin-rich matrix cells of the bulb in anagen follicles and the hair shaft, are principally targeted by IPL treatment, while white hairs and epidermis remained unaffected. Damage caused by heat sometimes extended over the dermal papilla cells, while stem cells were mostly spared. CONCLUSIONS: IPL epilation principally targets pigmented structures. Our results suggest that, under the tested conditions, collateral damage does not deplete stem cells. Damage at the dermal papilla was observed only with high-energy treatment modalities. Extrapolated to frequently treated hairs, these observations explain why some hairs grow back after a single IPL treatment.

[Regenerative medicine: stem cells, cellular and matricial interactions in the reconstruction of skin and cornea by tissue engineering]. / La médecine régénératrice : les cellules souches, les interactions cellulaires et matricielles dans la reconstruction cutanée et cornéenne par génie tissulaire.

Considering that there is a shortage of organ donor, the aim of tissue engineering is to develop substitutes for the replacement of wounded or diseased tissues. Autologous tissue is evidently a preferable transplant material for long-term graft persistence because of the unavoidable rejection reaction occuring against allogeneic transplant. For the production of such substitutes, it is essential to control the culture conditions for post-natal human stem cells. Furthermore, histological organization and functionality of reconstructed tissues must approach those of native organs. For self-renewing tissues such as skin and cornea, tissue engineering strategies must include the preservation of stem cells during the in vitro process as well as after grafting to ensure the long-term regeneration of the transplants. We described a tissue engineering method named the self-assembly approach allowing the production of autologous living organs from human cells without any exogenous biomaterial. This approach is based on the capacity of mesenchymal cells to create in vitro their own extracellular matrix and then reform a tissue. Thereafter, various techniques allow the reorganization of such tissues in more complex organ such as valve leaflets, blood vessels, skin or cornea. These tissues offer the hope of new alternatives for organ transplantation in the future. In this review, the importance of preserving stem cells during in vitro expansion and controlling cell differentiation as well as tissue organization to ensure quality and functionality of tissue-engineered organs will be discussed, while focusing on skin and cornea.

Paramedics' working strategies while loading a stretcher into an ambulance.

For paramedics, loading a stretcher into an ambulance is an activity with a high risk of back injury and accidents. The objective of this study was to document strategies paramedics use at work while loading a powered stretcher into an ambulance. A total of 249 stretcher loading operations performed by 58 paramedics, and 51 semistructured post-intervention interviews were analyzed. Almost three quarters of loading operations required additional actions (e.g., raising the shoulders and additional lifting) to insert the stretcher into the cot fastener system in the ambulance. Some strategies that were necessary to complete the stretcher loading operation seemed to have negative impacts on the workers' health, such as repositioning the stretcher. This action wastes time and requires significant physical efforts, as it is usually done alone. This study suggests some potential solutions, related to equipment, training, workers and work organization, to reduce the risk of injury while loading stretchers.

The effects of Quebec home aid services on the utilization profile of sociosanitory resources: a substitution study.

The development of home aid services in Quebec is based on the hypothesis that this new program will help to maintain at home people who would otherwise be institutionalized and also contribute to reducing costs in the health care sector. Accordingly, home aid services can be viewed as a substitute for conventional health care services. This study evaluates utilization modifications of health care services subsequent to the introduction of a home-aid program in October 1977. A modified, non-equivalent, control group design was used on a target population including all residents aged 65 or more in one region of Quebec. Multiple regression was used to explain variations in resources utilization in relation to population characteristics and different health care settings. Results for the utilization of hospitals are discussed. We discovered that the anticipated substitutive effects of a home-aid program on the use of health care services cannot be ascertained.

Strategic planning for hospitals--a health-needs approach.

This paper presents a strategic planning approach which provides methods for analysing hospitals in relation to their environment and for assessing their community dependency. Hospitals must not only focus on their clienteles but must also plan their future in relation to the needs of their constituency while taking into account the other elements of the health services network. The proposed approach also takes into account the need for all the actors concerned with the future of the hospital to become involved through an active-reactive-adaptive process.

The components of women's satisfaction with maternity care.

For a better understanding of how women's satisfaction with maternity care is affected, a representative sample of 1790 women from the Montreal area who had delivered four to seven months earlier were mailed a postal questionnaire; 938 (52.4%) completed and returned it. With factor analysis, we determined five dimensions to women's satisfaction: (a) the delivery itself, (b) medical care, (c) nursing care, (d) information received and participation in the decision-making process, and (e) physical aspects of the labor and delivery rooms. Multiple regression analysis was used to determine explicative factors for each of these dimensions of satisfaction. Items relative to the delivery process such as pain intensity, complications, and length of labor were the most important for the delivery experience itself. Participation in the decision-making process was the first component of satisfaction with medical care. Information received appeared to be the major component of their satisfaction with nursing care. The physical environment did not affect women's satisfaction with obstetric care.

Characterization of a 150 kDa accessory receptor for TGF-beta 1 on keratinocytes: direct evidence for a GPI anchor and ligand binding of the released form.

Transforming growth factor-beta (TGF-beta) is a key modulator of epidermal development and homeostasis, and has been shown to potently regulate keratinocyte migration and function during wound repair. There are three cloned TGF-beta receptors termed type I, type II, and type III that are found on most cell types. The types I and II are the signaling receptors, while the type III is believed to facilitate TGF-beta binding to the types I and II receptors. Recently, we reported that in addition to these receptors, human keratinocytes express a 150 kDa TGF-beta 1 binding protein (r150) which forms a heteromeric complex with the TGF-beta signaling receptors. This accessory receptor was described as glycosyl phosphatidylinositol-specific anchored based on its sensitivity to phosphatidylinositol phospholipase C (PIPLC). In the present study, we demonstrate that the GPI-anchor is contained in r150 itself and not on a tightly associated protein and that it binds TGF-beta 1 with an affinity similar to those of the types I and II TGF-beta signaling receptors. Furthermore, the PIPLC released (soluble) form of this protein is capable of binding TGF-beta 1 independently from the signaling receptors. In addition, we provide evidence that r150 is released from the cell surface by an endogenous phospholipase C. Our observation that r150 interacts with the TGF-beta signaling receptors, together with the finding that the soluble r150 binds TGF-beta 1 suggest that r150 in either its membrane anchored or soluble form may potentiate or antagonize TGF-beta signaling. Elucidating the mechanism by which r150 functions as an accessory molecule in TGF-beta signaling may be critical to understanding the molecular mechanisms underlying the regulation of TGF-beta action in keratinocytes.