Autologous keratinocyte suspension in platelet concentrate accelerates and enhances wound healing - a prospective randomized clinical trial on skin graft donor sites: platelet concentrate and keratinocytes on donor sites.

BACKGROUND: Wound healing involves complex mechanisms, which, if properly chaperoned, can enhance patient recovery. The abilities of platelets and keratinocytes may be harnessed in order to stimulate wound healing through the formation of platelet clots, the release of several growth factors and cytokines, and cell proliferation. The aim of the study was to test whether autologous keratinocyte suspensions in platelet concentrate would improve wound healing. The study was conducted at the Lausanne University Hospital, Switzerland in 45 patients, randomized to three different topical treatment groups: standard treatment serving as control, autologous platelet concentrate (PC) and keratinocytes suspended in autologous platelet concentrate (PC + K). Split thickness skin graft donor sites were chosen on the anterolateral thighs of patients undergoing plastic surgery for a variety of defects. Wound healing was assessed by the duration and quality of the healing process. Pain intensity was evaluated at day five. RESULTS: Healing time was reduced from 13.9 ± 0.5 days (mean ± SEM) in the control group to 7.2 ± 0.2 days in the PC group (P < 0.01). An addition of keratinocytes in suspension further reduced the healing time to 5.7 ± 0.2 days. Pain was reduced in both the PC and PC + K groups. Data showed a statistically detectable advantage of using PC + K over PC alone (P < 0.01). CONCLUSION: The results demonstrate the positive contribution of autologous platelets combined with keratinocytes in stimulating wound healing and reducing pain. This strikingly simple approach could have a significant impact on patient care, especially critically burned victims for whom time is of the essence. CLINICAL TRIAL REGISTRY INFORMATION: Protocol Record Identification Number: 132/03Registry URL: http://www.clinicaltrials.gov.

Scientific production on the applicability of phenytoin in wound healing

Phenytoin is an anticonvulsant that has been used in wound healing. The objectives of this study were to describe how the scientific production presents the use ofphenytoinas a healing agent and to discuss its applicability in wounds. A literature review and hierarchy analysis of evidence-based practices was performed. Eighteen articles were analyzed that tested the intervention in wounds such as leprosy ulcers, leg ulcers, diabetic foot ulcers, pressure ulcers, trophic ulcers, war wounds, burns, preparation of recipient graft area, radiodermatitis and post-extraction of melanocytic nevi. Systemic use ofphenytoinin the treatment of fistulas and the hypothesis of topical use in the treatment of vitiligo were found. In conclusion, topical use ofphenytoinis scientifically evidenced. However robust research is needed that supports a protocol for the use ofphenytoinas another option of a healing agent in clinical practice.

Duration of smoking cessation for the prevention of surgical wound healing complications

The study aimed to find scientific evidence about the duration of preoperative smoking cessation required to reduce surgical wound healing complications. An integrative review was performed in the databases, Latin American and Caribbean Literature on Health Sciences (LILACS) and Medical Literature Analysis and Retrieval System Online (MEDLINE), from 08/17/2012 to 09/17/2012, using the keywords: tobacco use cessation and wound healing; tobacco use cessation and preoperative period; tobacco use cessation and perioperative period (LILACS) and tobacco use cessation and perioperative period; tobacco use cessation and wound healing (MEDLINE). Out of the 81 eligible studies, 12 were included. The duration of smoking cessation needed to reduce healing complications was at least four weeks (four studies with level of evidence I, three studies with level of evidence II, two studies with level of evidence IV, and one study with level of evidence VII).

Wound repair and regeneration.

The repair of wounds is one of the most complex biological processes that occur during human life. After an injury, multiple biological pathways immediately become activated and are synchronized to respond. In human adults, the wound repair process commonly leads to a non-functioning mass of fibrotic tissue known as a scar. By contrast, early in gestation, injured fetal tissues can be completely recreated, without fibrosis, in a process resembling regeneration. Some organisms, however, retain the ability to regenerate tissue throughout adult life. Knowledge gained from studying such organisms might help to unlock latent regenerative pathways in humans, which would change medical practice as much as the introduction of antibiotics did in the twentieth century.

GLUTAMATE RECEPTOR-LIKE genes mediate leaf-to-leaf wound signalling.

Wounded leaves communicate their damage status to one another through a poorly understood process of long-distance signalling. This stimulates the distal production of jasmonates, potent regulators of defence responses. Using non-invasive electrodes we mapped surface potential changes in Arabidopsis thaliana after wounding leaf eight and found that membrane depolarizations correlated with jasmonate signalling domains in undamaged leaves. Furthermore, current injection elicited jasmonoyl-isoleucine accumulation, resulting in a transcriptome enriched in RNAs encoding key jasmonate signalling regulators. From among 34 screened membrane protein mutant lines, mutations in several clade 3 GLUTAMATE RECEPTOR-LIKE genes (GLRs 3.2, 3.3 and 3.6) attenuated wound-induced surface potential changes. Jasmonate-response gene expression in leaves distal to wounds was reduced in a glr3.3 glr3.6 double mutant. This work provides a genetic basis for investigating mechanisms of long-distance wound signalling in plants and indicates that plant genes related to those important for synaptic activity in animals function in organ-to-organ wound signalling.

How geographic distance and depth drive ecological variability and isolation of demersal fish communities in an archipelago system (Cape Verde, Eastern Atlantic Ocean)

Cape Verde is a tropical oceanic ecosystem, highly fragmented and dispersed, with islands physically isolated by distance and depth. To understand how isolation affects the ecological variability in this archipelago, we conducted a research project on the community structure of the 18 commercially most important demersal fishes. An index of ecological distance based on species relative dominance (Di) is developed from Catch Per Unit Effort, derived from an extensive database of artisanal fisheries. Two ecological measures of distance between islands are calculated: at the species level, DDi, and at the community level, DD (sum of DDi). A physical isolation factor (Idb) combining distance (d) and bathymetry (b) is proposed. Covariance analysis shows that isolation factor is positively correlated with both DDi and DD, suggesting that Idb can be considered as an ecological isolation factor. The effect of Idb varies with season and species. This effect is stronger in summer (May to November), than in winter (December to April), which appears to be more unstable. Species react differently to Idb, independently of season. A principal component analysis on the monthly (DDi) for the 12 islands and the 18 species, complemented by an agglomerative hierarchical clustering, shows a geographic pattern of island organization, according to Idb. Results indicate that the ecological structure of demersal fish communities of Cape Verde archipelago, both in time and space, can be explained by a geographic isolation factor. The analytical approach used here is promising and could be tested in other archipelago systems.

Controlling wound odor with metronidazole: a systematic review

AbstractOBJECTIVEVerifying the evidence of therapeutic efficacy in the topical application of metronidazole for controlling wound odor.METHODSA systematic literature review, according to the Cochrane Collaboration recommendations.RESULTS329 articles were identified in the Cochrane, LILACS, SciELO, CINAHL and PubMed databases, with 14 of them being included in the final sample. Two of the studies were double-blind randomized clinical trial studies.CONCLUSIONThe actual effectiveness of metronidazole in controlling wound odor cannot yet be evidenced due to the absence of strong evidence from studies on the subject, despite clinical practice recommending its benefits.

Role of PPARβ in keratinocyte adhesion and migration during skin wound healing

RESUME L'homéostasie du tissu cutané est assurée par des interactions étroites entre les cellules le composant et par l'équilibre entre la différenciation et la prolifération des kératinocytes devant permettre un renouvellement constant du tissu. Après une blessure, les kératinocytes environnant la zone blessée sont activés par des cytokines. Ils acquièrent alors un phénotype migratoire qui s'accompagne d'une modulation de l'activité protéolytique de la matrice extra cellulaire, d'une modulation de la dynamique du cytosquelette d'active, de la polarisation de la cellule, de l'affaiblissement des contacts entre cellules et de changements dans leurs contacts avec la matrice extra cellulaire. PPARβ est un facteur de transcription activé par les acides gras et leurs dérivés. Il appartient à la famille des récepteurs nucléaires aux hormones et son expression est avérée dans les kératinocytes des follicules pileux et dans les kératinocytes inter-folliculaires activés par la blessure cutanée. Le rôle de PPARβ dans la peau est principalement lié à son effet protecteur contre l'apoptose ainsi qu'à son implication dans l'équilibre dynamique entre la prolifération et la différentiation des kératinocytes. L'objet de ce travail fut de déterminer le rôle de PPARβ dans les processus d'adhésion et de migration des kératinocytes activés durant la régénération de l'épithélium blessé. Nous avons montré que les souris dépourvues du gène codant pour PPARβ ont de sévères imperfections affectant la morphologie de l'épithélium. Ce phénotype est corrélé à la modulation imparfaite du réseau d'active chez les souris dépourvues de PPARβ, à un défaut de localisation de l'intégrine α3 impliquée dans les complexes induisant la migration cellulaire, ainsi qu'à la modulation de l'expression d'acteurs majeurs affectant l'activité protéolytique de la matrice extra cellulaire. En conclusion, nos résultats montrent que PPARβ est impliqué dans le contrôle de la dynamique du cytosquelette d'active et la polarisation des kératinocytes activés. PPARβ étant impliqué dans l'acquisition d'un phénotype migratoire, il est légitime de se demander s'il intervient de même dans d'autres types cellulaires, par exemple dans la transition épithéliale-mésenchymateuse durant le développement, ou encore la progression de cellules tumorales. SUMMARY Highly coordinated intercellular interactions and single cell metabolism ensure cell and tissue maintenance of the skin. Healing of a skin wound involves keratinocyte activation by cytokines and growth factors. Activated keratinocytes acquire a motile phenotype that requires extracellular matrix remodeling and subsequent ligand activation through proteolytic activity, as well as cytoskeletal reorganisation induced by the release of cell-cell junctions and by the signalling relayed via integrin receptors and their cytoplasmic adaptors. PPARβ is a transcription factor activated by polyunsaturated fatty acids and fatty acid derivatives which belong to the nuclear hormone receptor superfamily. It is expressed in activated keratinocytes where it plays an essential role in protecting them from apoptosis. In addition, it plays an important function in hair follicle morphogenesis at the time of elongation, via the regulation of the balance between keratinocyte differentiation and proliferation. The aim of the present work was to determine if PPARβ is also involved in the regulation of migration and adhesion properties of keratinocytes during skin wound healing. We have shown that wounded PPARβ null mice display severe abnormalities of the keratinocyte migratory layer as shown at the histological level and using three-dimensional reconstruction. This altered migratory phenotype is correlated to altered dynamic of the actin cytoskeleton network, impaired α3 integrin localisation in migrating keratinocytes and changes in the expression of a key actor involved in extracellular matrix proteolytic activity. These results show that PPARβ is implicated in the fine tuning of the actin network organisation and the polarisation of activated keratinocytes following an epithelial wound. Whether these mechanisms are also controlled by PPARβ in other cell types during epithelial mesenchymal transition or tumour cell progression is an interesting question to rise.

Influence of photoperiod on body weight and depth of burrowing in larvae of Chrysomya megacephala (Fabricius) (Diptera, Calliphoridae) and implications for forensic entomology

Blowflies use discrete, ephemeral breeding sites for larval nutrition. After exhaustion of the food supply, the larvae disperse in search of sites to pupate or to seek other sources of food in a process known as post-feeding larval dispersal. In this study, some of the most important aspects of this process were investigated in larvae of the blowflies Chrysomya megacephala exposed to a variety of light: dark (LD) cycles (0:0 h, 12:12 h and 24:0 h) and incubated in tubes covered with vermiculite. For each pupa, the body weight and depth of burrowing were determined. Statistical tests were used to examine the relationship of depth of burrowing and body weight to photoperiod at which burrowing occurred. The study of burial behavior in post-feeding larval dispersing can be useful for estimating the postmortem interval (PMI) of human corpses in forensic medicine.

Biologicals and fetal cell therapy for wound and scar management.

Few biopharmaceutical preparations developed from biologicals are available for tissue regeneration and scar management. When developing biological treatments with cellular therapy, selection of cell types and establishment of consistent cell banks are crucial steps in whole-cell bioprocessing. Various cell types have been used in treatment of wounds to reduce scar to date including autolog and allogenic skin cells, platelets, placenta, and amniotic extracts. Experience with fetal cells show that they may provide an interesting cell choice due to facility of outscaling and known properties for wound healing without scar. Differential gene profiling has helped to point to potential indicators of repair which include cell adhesion, extracellular matrix, cytokines, growth factors, and development. Safety has been evidenced in Phase I and II clinical fetal cell use for burn and wound treatments with different cell delivery systems. We present herein that fetal cells present technical and therapeutic advantages compared to other cell types for effective cell-based therapy for wound and scar management.

Chronic wound healing by fetal cell therapy may be explained by differential gene profiling observed in fetal versus old skin cells.

Engineering of fetal tissue has a high potential for the treatment of acute and chronic wounds of the skin in humans as these cells have high expansion capacity under simple culture conditions and one organ donation can produce Master Cell Banks which can fabricate over 900 million biological bandages (9 x 12cm). In a Phase 1 clinical safety study, cases are presented for the treatment of therapy resistant leg ulcers. All eight patients, representing 13 ulcers, tolerated multiple treatments with fetal biological bandages showing no negative secondary effects and repair processes similar to that seen in 3rd degree burns. Differential gene profiling using Affymetrix gene chips (analyzing 12,500 genes) were accomplished on these banked fetal dermal skin cells compared to banked dermal skin cells of an aged donor in order to point to potential indicators of wound healing. Families of genes involved in cell adhesion and extracellular matrix, cell cycle, cellular signaling, development and immune response show significant differences in regulation between banked fetal and those from banked old skin cells: with approximately 47.0% of genes over-expressed in fetal fibroblasts. It is perhaps these differences which contribute to efficient tissue repair seen in the clinic with fetal cell therapy.

Four 13-lipoxygenases contribute to rapid jasmonate synthesis in wounded Arabidopsis thaliana leaves: a role for lipoxygenase 6 in responses to long-distance wound signals.

Damage-inducible defenses in plants are controlled in part by jasmonates, fatty acid-derived regulators that start to accumulate within 30 s of wounding a leaf. Using liquid chromatography-tandem mass spectrometry, we sought to identify the 13-lipoxygenases (13-LOXs) that initiate wound-induced jasmonate synthesis within a 190-s timeframe in Arabidopsis thaliana in 19 single, double, triple and quadruple mutant combinations derived from the four 13-LOX genes in this plant. All four 13-LOXs were found to contribute to jasmonate synthesis in wounded leaves: among them LOX6 showed a unique behavior. The relative contribution of LOX6 to jasmonate synthesis increased with distance from a leaf tip wound, and LOX6 was the only 13-LOX necessary for the initiation of early jasmonate synthesis in leaves distal to the wounded leaf. Herbivory assays that compared Spodoptera littoralis feeding on the lox2-1 lox3B lox4A lox6A quadruple mutant and the lox2-1 lox3B lox4A triple mutant revealed a role for LOX6 in defense of the shoot apical meristem. Consistent with this, we found that LOX6 promoter activity was strong in the apical region of rosettes. The LOX6 promoter was active in and near developing xylem cells and in expression domains we term subtrichomal mounds.

Deletion of delta-opioid receptor in mice alters skin differentiation and delays wound healing.

In addition to their well-known antinociceptive action, opioids can modulate non-neuronal functions, such as immune activity and physiology of different cell types. Several findings suggest that the delta-opioid receptor (DOR) and its endogenous ligands (enkephalins) are important players in cell differentiation and proliferation. Here we show the expression of DOR in mouse skin and human skin cultured fibroblasts and keratinocytes using RT-PCR. In DOR knock-out (KO) mice, a phenotype of thinner epidermis and higher expression of cell differentiation marker cytokeratin 10 (CK 10) were observed compared with wild type (WT). Using a burn wound model, significant wound healing delay (about 2 days) and severe epidermal hypertrophy were shown at the wound margin of DOR KO mice. This wound healing delay was further investigated by immunohistochemistry using markers for proliferation, differentiation, re-epithelialization, and dermal repair (CK 6, CK 10, and collagen IV). The levels of all these markers were increased in wounds of KO mice compared with WT. During the wound healing, the epidermal thickness in KO mice augments faster and exceeds that of the WT by day 3. These results suggest an essential role of DOR in skin differentiation, proliferation, and migration, factors that are important for wound healing.

On the depth of blowup algebras of ideals with analytic deviation one

Let I be an ideal in a local Cohen-Macaulay ring (A, m). Assume I to be generically a complete intersection of positive height. We compute the depth of the Rees algebra and the form ring of I when the analytic deviation of I equals one and its reduction number is also at most one. The formu- las we obtain coincide with the already known formulas for almost complete intersection ideals.