Influence of deep sternal wound infection on long-term survival after cardiac surgery.

BACKGROUND: This study aimed to investigate the influence of deep sternal wound infection on long-term survival following cardiac surgery. MATERIAL AND METHODS: In our institutional database we retrospectively evaluated medical records of 4732 adult patients who received open-heart surgery from January 1995 through December 2005. The predictive factors for DSWI were determined using logistic regression analysis. Then, each patient with deep sternal wound infection (DSWI) was matched with 2 controls without DSWI, according to the risk factors identified previously. After checking balance resulting from matching, short-term mortality was compared between groups using a paired test, and long-term survival was compared using Kaplan-Meier analysis and a Cox proportional hazard model. RESULTS: Overall, 4732 records were analyzed. The mean age of the investigated population was 69.3±12.8 years. DSWI occurred in 74 (1.56%) patients. Significant independent predictive factors for deep sternal infections were active smoking (OR 2.19, CI95 1.35-3.53, p=0.001), obesity (OR 1.96, CI95 1.20-3.21, p=0.007), and insulin-dependent diabetes mellitus (OR 2.09, CI95 1.05-10.06, p=0.016). Mean follow-up in the matched set was 125 months, IQR 99-162. After matching, in-hospital mortality was higher in the DSWI group (8.1% vs. 2.7% p=0.03), but DSWI was not an independent predictor of long-term survival (adjusted HR 1.5, CI95 0.7-3.2, p=0.33). CONCLUSIONS: The results presented in this report clearly show that post-sternotomy deep wound infection does not influence long-term survival in an adult general cardio-surgical patient population.

Characterisation of "fou2", a constitutive wound-activated mutant and analysis of the proteome and leaf physiology in the region proximal to wounds in Arabidopsis

Résumé : Les jasmonates (JA), une famille d'hor1none végétale, jouent un rôle central dans la réponse à la blessure, et aux attaques d'insectes et de pathogènes. Les JA sont principalement dérivés d'un acide gras, l'acide linolénique. L'addition par une lipoxygénase d'une molécule d'oxygène à l'acide linolénique initie la synthèse de JA. Cependant les mécanismes régulant l'activation de la biosynthèse de JA ne sont pas encore connus. C'est pour cette raison que dans ce travail, nous avons caractérisé chez Arabidopsis thaliana (l'Arabette des Dames) un mutant fou2 dont l'activité lipoxygénase est plus élevée que celle d'une plante sauvage. Les niveaux de JA sont constitutivement plus élevés et l'activation de la synthèse de JA après blessure est fortement plus induite chez fou2 que chez le type sauvage. En outre, fou2 est plus résistant au pathogène Botrytis cinerea et à la chenille Spodoptera littoralis. Afin de comprendre quel mécanisme chez fou2 génére ce phénotype, nous avons cloné le gène responsable du phénotype de fou2. Le mutant fou2 porte une mutation dans le gène d'un canal à deux pores transportant probablement du potassium, du lumen de la vacuole végétale vers le compartiment cytosolique. L'analyse du protéome de fou2 a permis d'identifier une expression plus élevée de sept protéines régulées par les JA ou le stress. La découverte de l'implication d'un canal dans le phénotype de fou2 renforce l'hypothèse que les flux de cations pourraient être impliqués dans les étapes précoces de la synthèse des JA. Nous avons également étudié le protéome et la physiologie d'une feuille blessée, Pour évaluer les changements d'expression protéique en réponse à la blessure et contrôlés par les JA, nous avons quantifié l'expression de 5937 protéines chez une plante d'Arabidopsis sauvage et chez un mutant incapable de synthétiser des JA. Parmi ces 5937 protéines, nous avons identifié 99 protéines régulées par la blessure chez le type sauvage. Nous avons observé pour 65% des protéines dont l'expression protéique changeait après blessure une bonne corrélation entre la quantité de transcrits et de protéines. Plusieurs enzymes de la voie des chorismates impliquées dans la biosynthèse des acides aminés phénoliques étaient induites par les JA après blessure. Une quantification des acides aminés a montré que les niveaux d'acides aminés phénoliques augmentaient significativement après blessure. La blessure induisait aussi des changements dans l'expression de protéines impliquées dans la réponse au stress et particulièrement au stress oxydatif. Nous avons quantifié l'état réduit et oxydé du glutathion, un tripeptide qui, sous sa forme réduite, est l'antioxydant majeur des cellules. Nous avons trouvé une quantité significativement plus élevée de glutathion oxydé chez le type sauvage blessé que chez la plante aus blessée. Ce résultat suggère que la génération d'un stress oxydatif et la proportion relative de glutathions réduits et oxydés sont contrôlés par les JA après blessure. Abstract : Plants possess a family of potent fatty acid-derived wound-response and developmental regulators: the jasmonates. These compounds are derived from the tri?unsaturated fatty acid a-linolenic-acid (18:3). Addition of an oxygen molecule to 18:3 by 13-lipoxygenases (13-LOX) initiates JA biosynthesis. Actually components regulating the activation of JA biosynthesis are poorly defined. Therefore we characterized in Arabidopsis thaliana the fatty acid Qxygenation upregulated 2 (fou2) mutant, which was previously isolated in a screen for mutants with an enhanced 13-LOX activity. As a consequence of this increased 13-LOX activity, JA levels in fou2 are higher than in wild type (WT) and wounding strongly increased JA biosynthesis compared to WT. fou2 was more resistant to the fungus Botrytis cinerea and the generalist caterpillar Spodaptera littomlis, The fou2 mutant carries a missense mutation in the Two Pore Channel 1 gene (TPCJ), which encodes a vacuolar cation channel transporting probably K* into the cytosol. Patchclamp analysis of fou2 vacuolar membranes showed faster time-dependent conductivity and activation of the mutated channel at lower membrane potentials than wild-type. Proteomic analysis of fou2 leaves identified increased levels of seven biotic stress- and JA- inducible proteins. The discovery of the implication of a channel in the fou2 phenotype strenghtens the hypothesis that cation fluxes might be implicated in early steps of JA synthesis. We further concentrated on the proteome and leaf physiology in the region proximal to wounds in Arabidopsis using the WT and the aos JA-biosynthesis deficient mutant in order to find JA- induced proteins changes. We used two successive proteomic methods to assess protein changes in response to wounding Arabidopsis leaves, two dimensional electrophoresis (2DE) and linear trap quadrupole ion-trap mass spectrometry. In total 5937 proteins were quantified. We identified 99 wound-regulated proteins in the WT. Most these proteins were also wound-regulated at the transcript level showing a good correlation between transcript and protein abundance. We identified several wound-regulated enzymes involved in amino acid biosynthesis and confirmed this result by amino acid quantification. Proteins involved in stress reponses were upregulated, particularly in redox species regulation. We found a significantly higher quantity of oxidized glutathione in wounded WT relative to wounded aos leaves. This result suggests that levels of reduced glutathione are controlled by JA after wounding.

High bacterial load in negative pressure wound therapy (NPWT) foams used in the treatment of chronic wounds.

No earlier study has investigated the microbiology of negative pressure wound therapy (NPWT) foam using a standardized manner. The purpose of this study is to investigate the bacterial load and microbiological dynamics in NPWT foam removed from chronic wounds (>3 months). To determine the bacterial load, a standardized size of the removed NPWT foam was sonicated. The resulting sonication fluid was cultured, and the colony-forming units (CFU) of each species were enumerated. Sixty-eight foams from 17 patients (mean age 63 years, 71% males) were investigated. In 65 (97%) foams, â0/00¥âeuro0/001 and in 37 (54%) â0/00¥2 bacterial types were found. The bacterial load remained high during NPWT treatment, ranging from 10(4) to 10(6) CFU/ml. In three patients (27%), additional type of bacteria was found in subsequent foam cultures. The mean bacterial countâeuro0/00±âeuro0/00standard deviation was higher in polyvinyl alcohol foam (6.1âeuro0/00±âeuro0/000.5 CFU/ml) than in polyurethane (5.5âeuro0/00±âeuro0/000.8 CFU/ml) (pâeuro0/00=âeuro0/000.02). The mean of log of sum of CFU/ml in foam from 125âeuro0/00mmHg (5.5âeuro0/00±âeuro0/000.8) was lower than in foam from 100âeuro0/00mmHg pressure (5.9âeuro0/00±âeuro0/000.5) (pâeuro0/00=âeuro0/000.01). Concluding, bacterial load remains high in NPWT foam, and routine changing does not reduce the load.

LDLs stimulate p38 MAPKs and wound healing through SR-BI independently of Ras and PI3 kinase.

Intracellular signals elicited by LDLs are likely to play a role in the pathogenesis associated with increased LDL blood levels. We have previously determined that LDL stimulation of human skin fibroblasts, used as a model system for adventitial fibroblasts, activates p38 mitogen-activated protein kinases (MAPKs), followed by IL-8 production and increased wound-healing capacity of the cells. The proximal events triggering these responses had not been characterized, however. Here we show that MAPK kinases MKK3 and MKK6, but not MKK4, are the upstream kinases responsible for the activation of the p38 MAPKs and stimulation of wound closure in response to LDLs. Phosphoinositide 3 kinases (PI3Ks) and Ras have been suggested to participate in lipoprotein-induced MAPK activation. However, specific PI3K inhibitors or expression of a dominant-negative form of Ras failed to blunt LDL-induced p38 MAPK activation. The classical LDL receptor does not participate in LDL signaling, but the contribution of other candidate lipoprotein receptors has not been investigated. Using cells derived from scavenger receptor class B type I (SR-BI) knockout mice or the BLT-1 SR-BI inhibitor, we now show that this receptor is required for LDLs to stimulate p38 MAPKs and to promote wound healing. Identification of MKK3/6 and SR-BI as cellular relays in LDL-mediated p38 activation further defines the signaling events that could participate in LDL-mediated pathophysiological responses.

Development of a cost-effective method for platelet-rich plasma (PRP) preparation for topical wound healing.

Platelet-rich plasma (PRP) is a volume of plasma fraction of autologous blood having platelet concentrations above baseline whole-blood values due to processing and concentration. PRP is used in various surgical fields to enhance soft-tissue and bone healing by delivering supra-physiological concentrations of autologous platelets at the site of tissue damage. These preparations may provide a good cellular source of various growth factors and cytokines, and modulate tissue response to injury. Common clinically available materials for blood preparations combined with a two-step centrifugation protocol at 280g each, to ensure cellular component integrity, provided platelet preparations which were concentrated 2-3 fold over total blood values. Costs were shown to be lower than those of other methods which require specific equipment and high-cost disposables, while safety and traceability can be increased. PRP can be used for the treatment of wounds of all types including burns and also of split-thickness skin graft donor sites, which are frequently used in burn management. The procedure can be standardized and is easy to adapt in clinical settings with minimal infrastructure, thus enabling large numbers of patients to benefit from a form of cellular therapy.

Long-distance wound signalling in arabidopsis

The leaves of all plants use elaborate and inducible defence systems to protect themselves. A wide variety of such defences are known and they include defence chemicals such as alkaloids, phenolics and terpenes, physical structures ranging from fibre cells to silica deposits, and a wide variety of defence proteins many of which target digestive processes in herbivores. It has long been known that the defence responses of plants under attack by insects are not restricted to the site of attack. Instead, if a leaf is damaged, defence can be triggered in other parts of the plant body, for example in distal leaves or even in roots and flowers. This raises the question of what are the organ-to-organ signals that coordinate this process. Several hypotheses have been proposed. These include the long-distance transfer of chemical signals through the plant vasculature, hydraulic signals that may transit through the xylem, and electrical signals that would move through living tissues such as the phloem. Much evidence for each of these scenarios has been published. In this thesis we took advantage of the fact that many plant defence responses are regulated by a signal transduction pathway based on a molecule called jasmonic acid. We used this molecule, one of its derivatives (jasmonoyl-isoleucine), and some of the genes it regulates as markers. Using these we investigated the possible role of the electrical signals in the leaf- to-leaf activation of the jasmonate pathway. We found that feeding insects stimulate easily detected electrical activity in the leaves of Arabidopsis thaliana and we used non-invasive surface electrodes to record this activity. This approach showed that jasmonate pathway activity and the electrical activity provoked by mechanical wounding occurred within identical spatial boundaries. Measurements of the apparent speed of surface potentials agreed well with previous velocity estimates for the speed of leaf-to-leaf signals that activate the jasmonate pathway. Using this knowledge we were able to investigate the effects of current injection into Arabidopsis leaves. This resulted in the strong expression of many jasmonate-regulated genes. All these results showed that electrical activity and the activation of jasmonate signalling were highly correlated. In order to test for possible causal links between the two processes, we conducted a small-scale reverse genetic screen on a series of T-DNA insertion mutants in ion channel genes and in other genes encoding proteins such as proton pumps. This screen, which was based on surface potential measurements, revealed that mutations in genes related to ionotropic glutamate receptors in animals had impaired electrical activity after wounding. Combining mutation of two of these glutamate-receptor-like genes in a double mutant reduced the response of leaves to current injection. When a leaf of this double mutant was wounded it failed to transmit a long-distance signal to a distal leaf. This result distinguished the double mutant from the wild-type plant and provides the first genetic evidence that electrical signalling is necessary to coordinate defence responses between organs in plants. - Les feuilles des plantes disposent de systèmes de défense inductibles très élaborés. Un grand nombre de ces systèmes de défenses sont connus et sont basés sur des composés chimiques comme les alcaloïdes, les composés phénoliques ou les terpènes, des systèmes physiques allant de la production de cellules fibreuses aux cristaux de silice ainsi qu'un grand nombre de protéines de défense ciblant le processus digestif des herbivores. Il est connu dépuis longtemps que la réponse défensive de la plante face à l'attaque pas un insecte n'est pas seulement localisée au niveau de la zone d'attaque. A la place, si une feuille est attaquée, les systèmes de défense peuvent être activés ailleurs dans la plante, comme par exemple dans d'autres feuilles, les racines ou même les fleurs. Ces observations soulèvent la question de la nature des signaux d'organes à organes qui régulent ces systèmes. Plusieurs hypothèses ont été formulées; une ou plusieures molécules pourraient être véhiculées dans la plante grâce au système vasculaire, un signal hydraulique transmis au travers du xylème ou encore des signaux électriques transmis par les cellules comme dans le phloème par exemple. De nombreuses études ont été publiées sur ces différentes hypothèses. Dans ce travail de thèse, nous avons choisi d'utiliser à notre avantage le fait que de nombreuses réponses de défense de la plante sont régulées par une même voie de signalisation utilisant l'acide jasmonique. Nous avons utilisé comme marqueurs cette molécule, un de ses dérivés (le jasmonoyl-isoleucine) ainsi que certains des gènes que l'acide jasmonique régule. Nous avons alors testé l'implication de la transmission de signaux électriques dans l'activation de la voie du jasmonate de feuille à feuille. Nous avons découvert que les insectes qui se nourrissent de feuilles d'Arabidopsis thaliana activent un signal électrique que nous avons pu mesurer grâce à une technique non invasive d'électrodes de surface. Les enregistrements ont montré que la génération de signaux électriques et l'activation de la voie du jasmonate avaient lieu aux mêmes endroits. La mesure de la vitesse de déplacement des impulsions électriques correspond aux estimations faites concernant l'activation de la voie du jasmonate. Grâce à cela, nous avons pu tester l'effet d'injection de courant électrique dans les feuilles d'Arabidopsis. La conséquence a été une forte expression de nombreux gènes de la voie du jasmonate, suggérant une forte corrélation entre l'activité électrique et l'activation de la voie du jasmonate. Afin de tester le lien de cause entre ces deux phénomènes, nous avons entrepris un criblage génétique sur une série de mutants d'insertion à l'ADN-T dans des gènes de canaux ioniques et d'autres gènes d'intérêt comme les gènes des pompes à protons. Ce criblage, basé sur la mesure de potentiels de surface, a permis de montrer que plusieurs mutations de gènes liés aux récepteurs au glutamate ionotropique présentent une baisse drastique de leurs activités électriques après une blessure mécanique des feuilles par rapport au type sauvage. Par la combinaison de deux mutations de ces récepteurs au glutamate en un double mutant, on obtient une réponse à la stimulation électrique encore plus faible. Quand une feuille du double mutant est blessée, elle est incapable de transmettre un signal à longue distance vers une feuille éloignée. Ce résultat permet de distinguer le double mutant de la plante sauvage et amène la première preuve génétique que l'activité électrique est nécessaire pour coordonner les réponses de défense entre les organes chez les plantes.

Plasmacytoid dendritic cells sense skin injury and promote wound healing through type I interferons.

Plasmacytoid dendritic cells (pDCs) are specialized type I interferon (IFN-α/β)-producing cells that express intracellular toll-like receptor (TLR) 7 and TLR9 and recognize viral nucleic acids in the context of infections. We show that pDCs also have the ability to sense host-derived nucleic acids released in common skin wounds. pDCs were found to rapidly infiltrate both murine and human skin wounds and to transiently produce type I IFNs via TLR7- and TLR9-dependent recognition of nucleic acids. This process was critical for the induction of early inflammatory responses and reepithelization of injured skin. Cathelicidin peptides, which facilitate immune recognition of released nucleic acids by promoting their access to intracellular TLR compartments, were rapidly induced in skin wounds and were sufficient but not necessary to stimulate pDC activation and type I IFN production. These data uncover a new role of pDCs in sensing tissue damage and promoting wound repair at skin surfaces.

ROCK Inhibitor Enhances Adhesion and Wound Healing of Human Corneal Endothelial Cells.

Maintenance of corneal transparency is crucial for vision and depends mainly on the endothelium, a non-proliferative monolayer of cells covering the inner part of the cornea. When endothelial cell density falls below a critical threshold, the barrier and "pump" functions of the endothelium are compromised which results in corneal oedema and loss of visual acuity. The conventional treatment for such severe disorder is corneal graft. Unfortunately, there is a worldwide shortage of donor corneas, necessitating amelioration of tissue survival and storage after harvesting. Recently it was reported that the ROCK inhibitor Y-27632 promotes adhesion, inhibits apoptosis, increases the number of proliferating monkey corneal endothelial cells in vitro and enhance corneal endothelial wound healing both in vitro and in vivo in animal models. Using organ culture human cornea (N = 34), the effect of ROCK inhibitor was evaluated in vitro and ex vivo. Toxicity, corneal endothelial cell density, cell proliferation, apoptosis, cell morphometry, adhesion and wound healing process were evaluated by live/dead assay standard cell counting method, EdU labelling, Ki67, Caspase3, Zo-1 and Actin immunostaining. We demonstrated for the first time in human corneal endothelial cells ex vivo and in vitro, that ROCK inhibitor did not induce any toxicity effect and did not alter cell viability. ROCK inhibitor treatment did not induce human corneal endothelial cells proliferation. However, ROCK inhibitor significantly enhanced adhesion and wound healing. The present study shows that the selective ROCK inhibitor Y-27632 has no effect on human corneal endothelial cells proliferative capacities, but alters cellular behaviours. It induces changes in cell shape, increases cell adhesion and enhances wound healing ex vivo and in vitro. Its absence of toxicity, as demonstrated herein, is relevant for its use in human therapy.

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.

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.