A Convolutional Neural Network for Electrical Fault Recognition in Active Magnetic Bearing Systems.

Active magnetic bearings are complex mechatronic systems that consist of mechanical, electrical, and software parts, unlike classical rolling bearings. Given the complexity of this type of system, fault detection is a critical process. This paper presents a new and easy way to detect faults based on the use of a fault dictionary and machine learning. The dictionary was built starting from fault signatures consisting of images obtained from the signals available in the system. Subsequently, a convolutional neural network was trained to recognize such fault signature images. The objective of this study was to develop a fault dictionary and a classifier to recognize the most frequent soft electrical faults that affect position sensors and actuators. The proposed method permits, in a computationally convenient way that can be implemented in real time, the determination of which component has failed and what kind of failure has occurred. Therefore, this fault identification system allows determining which countermeasure to adopt in order to enhance the reliability of the system. The performance of this method was assessed by means of a case study concerning a real turbomachine supported by two active magnetic bearings for the oil and gas field. Seventeen fault classes were considered, and the neural network fault classifier reached an accuracy of 93% on the test dataset.

Increased early inflammatory response and osteoclastic activity in gingival tissues following conventional osseous resective surgery compared with the fibre retention technique: a pilot study.

BACKGROUND AND OBJECTIVE: The retention of suprabony connective fibres attached into the root cementum during fibre retention osseous resective surgery (FibReORS) results in a more conservative intrasurgical removal of bone, and limits further bone loss and patient morbidity during healing, compared with conventional osseous resective surgery (ORS). This may be a result of the protective effect of preserved connective tissue over the interproximal sites and the lower activation of the inflammatory mechanisms. Thus, the aim of this pilot study was to compare the expression of inflammatory and osteoclastic activity markers in gingival tissues following FibReORS and ORS in the early postsurgical phase. MATERIAL AND METHODS: Twenty-six posterior sextants requiring osseous resective surgery were selected in 13 patients with chronic periodontitis: 13 sextants were randomly assigned to ORS and 13 to FibReORS in a split-mouth design. Gingival biospies were collected during the surgical sessions and at suture removal. Tissue samples were analysed to evaluate the expression of proinflammatory and immunity regulatory mediators (interleukin-1α, C-X-C motif chemokine ligand 5, interferon-γ and tumour necrosis factor-α), cluster of differentiation 14 (CD14; a monocyte/macrophage marker) and TRAP (an osteoclast marker) using immunohistochemical, immunofluorescence and cytofluorimetric analyses, respectively. RESULTS: Postsurgery, a higher number of inflammatory cells and stronger expression of proinflammatory cytokines were observed in the epithelium and connective tissue of ORS gingival samples compared with FibReORS gingival samples (p < 0.001). This was accompanied by increased numbers of CD14-positive and TRAP-positive cells. CONCLUSION: Retention of the supracrestal connective fibres appears to reduce the postsurgical intensity of the host-mediated inflammatory response.

Krabbe disease: involvement of connexin43 in the apoptotic effects of sphingolipid psychosine on mouse oligodendrocyte precursors.

Krabbe disease is a genetic demyelinating syndrome characterized by deficiency of the enzyme ß-galactosylceramidase, lysosomal psychosine accumulation, and loss of myelin-forming cells. In this study, some apoptotic markers such as apoptotic index (AI), DNA fragmentation, caspase-3, PTEN, Bad, and PI3K were determined in oligodendrocyte precursors from wild type or twitcher mice untreated or treated with psychosine. Twitcher is a natural mouse model of Krabbe disease containing a premature stop codon (W339X) in the ß-galactosylceramidase gene. Moreover, a possible involvement of connexin (Cx)43 in cell death of oligodendrocyte precursors induced by psychosine was investigated with the final aim to provide a contribution to the knowledge of the molecular mechanisms and pathophysiological events that occur in Krabbe disease. Connexins are a multigene family of structurally related trans-membrane proteins able to modulate essential cellular processes such as proliferation, differentiation and migration. Among these, Cx43 is the predominant isoform in many cell types, including neural progenitor cells. Our results showed an increase of AI, DNA fragmentation, caspase-3, PTEN, Bad, and Cx43 associated to a decrease of PI3K, pAKT and pBad. Taken together, these findings suggest an involvement of Cx43 in the psychosine-mediated apoptosis of primary oligodendrocyte progenitors from wild type or twitcher mice, used for the first time as cell models in comparison. It could open unexplored perspective also for other demyelinating diseases.

Unexpected resilience to experimental gingivitis of subepithelial connective tissue grafts in gingival recession defects: a clinical-molecular evaluation.

BACKGROUND AND OBJECTIVE: The subepithelial connective tissue graft (SCTG) is the most widely used procedure for the treatment of gingival recession defects. Little is known, however, as to whether the apposed gingival flaps are more predisposed to develop plaque-related inflammation compared to healthy sites. This has salient clinical implications, as the long-term results of root coverage will depend largely on the level of inflammation of the grafted tissue. METHODS: In the present split-mouth case-control study, clinical and biomolecular parameters were used to assess the level of inflammation of periodontal sites 12 mo after treatment with SCTG (test) and healthy non-treated gingivae (control) following the induction of plaque-related gingivitis in 19 patients. RESULTS: The data showed that test sites had a significantly (P < 0.05) lower gingival index and angulated bleeding score compared to control sites (gingival index = 1.05 ± 0.23 vs. 1.34 ± 0.47; angulated bleeding score = 0.34 ± 0.37 vs. 0.61 ± 0.39) after induction of experimental gingivitis, whereas the plaque index did not differ in the two groups (P > 0.05). With regard to the biomolecular parameters, baseline levels of the proinflammatory cytokine interleukin-1ß were higher in the gingival crevicular fluid of test sites. However, control sites exhibited more pronounced increase in the levels of interleukin-1ß compared to test sites, upon plaque accumulation, so that the final concentration was similar in both groups. No changes were recorded in the gingival crevicular fluid volume. CONCLUSION: Analysis of the data demonstrates that the sites of gingival recession treated with SCTG develop a lower degree of plaque-induced inflammation compared to healthy gingivae. This strongly suggests that SCTG does not predispose to inflammation and to further gingival recession and makes it a safe technique in the treatment of gingival defects.

Pholiotic acid promotes apoptosis in human metastatic melanoma cells.

Mushrooms produce a great variety of secondary metabolites that can be successful in both prevention and treatment of various cancers. In particular, higher Basidiomycete mushrooms contain various types of biologically active low-molecular compounds in fruiting bodies with suggested anticarcinogenic effects. The polyamine analogue {(2R)-2-[(S)-3-hydroxy-3-methylglutaryloxy] putrescine dicinnamamide} indicated with the name pholiotic acid, isolated for the first time by us from the fruiting bodies of the Basidiomycete Pholiota spumosa (Fr.) Sing. (Strophariaceae), inhibited the viability of human prostate cancer cells, such as other polyamine synthetic analogues that have shown antitumor activity in several types of cancer, including melanoma. Melanoma is an aggressive skin cancer that can metastasize to other organs and presents a high resistance to conventional therapies. In light of these considerations, the present study was therefore designed to assess whether this putrescine derivative could inhibit the growth of human metastatic melanoma cell lines, M14 and A2058. The results obtained demonstrate that this natural compound, at 12.5-50 µM concentration, was able to reduce cell viability of both cancer cells inducing cell death by intrinsic apoptotic pathway that probably involves PTEN activity, inhibition of Hsp70 expression and reactive oxygen species production. On the other hand, the increased expression of enzymes involved in polyamine catabolism trigger apoptotic cell death leading to polyamine depletion and generation of reactive oxygen species as by-products. In conclusion, these findings, starting point for further investigation, implement available our data to support pholiotic acid as an attractive potential chemopreventive agent, and provide a basis for further research into the use of this polyamine derivative as potential anticancer agent for melanoma in combination with existing therapies to improve treatment efficacy and overcome the obstacle of drug resistance.

Utility of routine preoperative laboratory testing for patients undergoing minor gynaecologic surgical procedures: interim analysis of their impact on intraoperative and postoperative complications.

Background: Despite discouragement from many scientific societies, routine preoperative testing remains a common practice. Minor gynaecological surgery, being widely performed in everyday practice, represents an opportunity for implementing cost-reduction policies by avoiding unnecessary diagnostic assessments. Objectives: To assess whether performing routine preoperative blood tests affects postoperative complications and cost-effectiveness in patients undergoing minor gynaecological surgery. Materials and Methods: An interim subgroup analysis of a retrospective study conducted by Fondazione Policlinico Gemelli (Rome) and Azienda Sanitaria Universitaria Friuli Centrale (Udine) was performed. Patients who underwent surgery under general anaesthesia were included. The studied population was divided based on the preoperative work up. Clinical data, surgical features and complications were collected. Main Outcome Measures: Intraoperative and postoperative complications, healthcare expenditure in two groups. Results: Subgroup analysis included 1191 patients in Centre A (Rome) who underwent routine complete preoperative tests and 500 patients in Centre B (Udine), who underwent exams only if indicated. Population characteristics were similar in two groups. Postoperative complications were observed in 1.2% and 1.4% of cases in Group A and Group B, respectively (p=0.70). Severe complications occurred in 0.3% of cases in Group A and 0.4% in Group B. Group B showed a cost saving of approximately 70 Euros per procedure (p < 0.001). Conclusions: Preliminary data indicate that routine perioperative assessment did not reduce complication rates, hospital readmissions or surgical reinterventions. Given the high number of procedures, performing specific preoperative tests only when indicated may result in significant cost reduction. What is new?: This study selectively highlights the potential benefits to overall public health expenditure that could be achieved through stricter adherence to guidelines on preoperative assessment in minor gynaecological surgery.

In vitro fertilization stimulation protocol for normal responder patients.

The aim of this prospective observational study is to determine the different outcomes of IVF/ICSI treatments after using antagonists or agonists of gonadotrophin-releasing hormone (GnRH) for controlled ovarian hyperstimulation (COH) in normal responder patients. Two hundred forty-seven patients undergoing IVF treatment at the Centre of Reproductive Medicine, Rome (CERMER), from January 2005 to December 2008, were included in the study. Patients were stimulated either with a standard long protocol with GnRH agonists (n = 156) or with GnRH antagonists (n = 91). The use of GnRH antagonists resulted in a significant reduction in the duration of the stimulation (Agonist Group 14.10 ± 2.25 vs Antagonist Group 11.34 ± 2.11; p < 0.001) and in the amount of gonadotrophin (IU of r-FSH) needed (Agonist Group 1878 ± 1109 vs Antagonist Group 1331 ± 1049; p = 0.0014). Moreover a lower number of cycles were cancelled with the antagonist protocol (4.39 vs 6.41%). The GnRH antagonist protocol, when compared to the GnRH agonist one, is associated with a similar clinical pregnancy rate, similar implantation rate, significantly lower gonadotrophin requirement and shorter duration of stimulation. For this reason, GnRH antagonists might be a good treatment even for normal responder patients undergoing IVF.

Heavy metals and placental fetal-maternal barrier: a mini-review on the major concerns.

BACKGROUND: Heavy metals (HMs) are environmental contaminants with toxic properties for wildlife and humans. The placenta is a privileged organ that, along with the fetal membranes and amniotic fluid, enables growth and development of the fetus during the physiological pregnancy. It also acts as a filter reducing the passage of harmful substances, protecting the embryo and then the fetus from exposure to pollutants. The placental barrier is not completely impermeable to the passage of harmful substances; indeed, HMs were detected not only in placental tissues, but also in amniotic fluid and umbilical cord blood. The amniotic fluid can be considered as a valuable marker of prenatal exposure to exogenous factors, and as an indicator of the integrity of placental barrier. The effect of an intrauterine exposure to heavy metals has been amply evaluated during the last decades. Several studies investigated the exposure to HMs in order to evaluate the mechanism of placental transfer and the impact on fetuses and later children's health. In particular,  the early exposure to Pb, Hg, and Cd was correlated to infant health effects, such as neurological, developmental, and endocrine disorders. The aim of this mini-review is to summarise the current state of knowledge about the interaction between HMs and placental barrier, considering possible implications on fetal health.

GnRH antagonists in assisted reproductive techniques: a review on the Italian experience.

Current Controlled Ovarian Stimulation (COH) for Assisted Reproductive Techniques (ART) pursues three main objectives: hypophyseal activity suppression, multiple follicle growth stimulation, and ovulation induction. By suppressing hypophyseal activity, it is possible to prevent untimely LH surge and allow the appropriate development of the leading follicle. The classical GnRH agonist long protocol is the most widely used in COH for ART. However, an alternative regimen based on GnRH antagonist has been recently introduced in clinical practice. As competitive antagonists, these drugs display an immediate and quickly reversible effect and they avoid hormonal withdrawal side effects. Moreover, this protocol shows undeniable advantages, including the shorter duration of the treatment, the lower amount of gonadotropin required, the shorter hormonal and ultrasound monitoring of patients, milder physical and emotional stress, and a lower risk of Ovarian Hyperstimulation Syndrome (OHSS). The use of GnRH antagonists was traditionally restricted to selected patients, as "poor responders" and women at high-risk of developing OHSS such as Polycystic Ovary Syndrome (PCOS) and patients who had previously experienced OHSS. These findings could prompt a trend to change from the standard agonist protocol to the antagonist protocol in all categories of patients. This review provides a comprehensive overview of the use of GnRH antagonist protocols applied both to IVF techniques and to IUI procedures in the Italian experience.

The addition of GnRH antagonists in intrauterine insemination cycles: a pilot study.

AIM: This prospective study was designed to assess whether the use of GnRH antagonists can improve the success rate of controlled ovarian stimulation (COS) in intrauterine insemination (IUI) treatments. PATIENTS AND METHODS: Eighty patients were divided into two groups: GnRH antagonist group (Group A, n=40) and control group (Group B, n=40). Patients in Group B underwent COS with recombinant Follicle Stimulating Hormone (r-FSH, 50-75 IU/d) only, while patients in Group A were administered r-FSH (50-75 IU/d) plus cetrorelix (0.25 mg/d, starting when ≥ 2 follicles ≥ 14 mm were detected on ultrasound scan). In both groups a single insemination was performed 36 hours after human Chorionic Gonadotropin (hCG, 250 mcg) administration. The primary outcome was clinical Pregnancy Rate (PR). Secondary outcomes were ongoing PR, incidence of Premature Luteinization (PL), number of follicles with mean diameter ≥ 16 mm and between 11 and 15 mm on the day of hCG administration, miscarriage rate, cycle cancellation rate, total amount of r-FSH used and duration of treatment. Student's t test and Chi-square test were used (p < .05 statistically significant). RESULTS: A total of 146 cycles were performed (Group A: n=72; Group B: n=74). A trend towards higher PR in Group A was detected, although it was not statistically significant (Clinical PR: 18.05% vs 10.81%). The number of follicles ≥ 16 mm was significantly increased in Group A. The incidence of both premature LH surge and premature luteinization (PL) was significantly higher in Group B. No significant differences were found in the duration of the stimulation protocol, and in the total amount of r-FSH administered. CONCLUSIONS: The addition of GnRH antagonist in COS/IUI protocol significantly increases the number of mature follicles. However, this multifollicular recruitment is not linked to a significantly higher PR.

Bone production by human maxillary sinus mucosa cells.

The Schneider membrane is the mucosa that covers the inner part of the maxillary sinus cavities. The free surface is a ciliated pseudostratified epithelium, while the deeper portion is a highly vascularized connective tissue. The stromal fraction, bordering the bony wall of the sinus, after tooth loss can exhibit increased osteoclastic activity resulting in resorption of the bone in the posterior maxilla. Goal of our study was to isolate and characterize mesenchymal progenitors in the Schneider's membrane connective net and to evaluate their self ability to differentiate toward osteoblastic lineage, in absence of osteoinductive factors and osteoconductive biomaterials of support. This should indicate that maxillary sinus membrane represents an useful an approachable source of MSCs for bone tissue engineering and cell therapy and owns the intrinsic capacity to restore maxillary bone after tooth loss without the needing of biomaterials.

Merkel cells and permanent disesthesia in the oral mucosa after soft tissue grafts.

Connective tissue grafts are routinely procedures in the treatment of gingival defects. The clinical success of the gingival tissue graft procedures anyway should ensure not only the aesthetic integration between the tissues but also the physiological activity of the graft in terms of sensitivity and immunity because the skin and the mucosae constitute the first natural aspecific borders against pathogens. The aim of this paper was to investigate nervous net recovery after connective graft procedure, in relation with sensorial alteration in the injured area. Results showed that there is a close link among the number of Merkel cells and the alteration of sensations. Merkel cells can be found isolated standing in the basal layer, supposed to have neuroendocrine functions in the epithelia or in larger group not associated with nerves; when found in association with nerves they are named Merkel complexes, acting as slow adapter mechanical receptor. Our data can be explained in two ways: Merkel cells increase as a consequence of tissue injury, a sort of "SOS cells" that secrete neuroendocrine signals to guide tissue healing; as an alternative the presence of the Merkel cells could be read as a derailment of tissue regeneration with the stop of cellular differentiation in the direction of an abnormal proliferation, a sort of mad stem cell.

Effectiveness of topical α-Tocopherol Acetate in burn infection treatment.

Infection following burn injury is critical, especially for patients with large total body surface area burns and in skin graft donor sites. Although various aspects of α-tocopherol acetate (α-TA) beneficial effects on wound healing have been validated, it appears that no study has specifically addressed its antimicrobial potential. The purpose of this study was to explore the therapeutic efficacy of topical application of α-TA in terms of bacterial load reduction. Between January 2018 and June 2018, 20 patients with mid-deep and deep burn wounds were included in the present study (average TBSA approximately 42%, range 25-67%). Patient average age was 47.75 years (range 25-72 years), 8 were male. In each patient two clinically similar areas were identified and treated every 24 hours with topical application of α-TA in the form of Filme Olio® (Group 1) and conventional medication (Group 2). All the patients had positive results for bacterial cultures before treatment. Despite the presence of initial bacterial infection, a quicker reduction of exudates and pain and a progressive and faster bacterial load reduction was observed in Group 1. Negative cultures were obtained after 3 days on average in Group 1 (range 1-6 days) and 8 days in Group 2 (range 5-9 days). This study clearly shows the importance of the therapeutic targeting of infection in the treatment of burns. α-TA may represent a safe, simple and inexpensive method for improving the healing of difficult wounds with local infection.

Les infections sont une complication majeure des brûlures, en particulier chez les patients largement atteints et au niveau des sites donneurs. Alors que ATA a été évalué, et considéré bénéfique, dans de nombreux aspects de la cicatrisation, aucune étude ne s'est penchée sur son potentiel antimicrobien. Cette étude a exploré l'effet de ATA topique sur la réduction de l'inoculum bactérien. Vingt patients dont 12 femmes, ayant des brûlures intermédiaires et profondes, ont été inclus dans cette étude, qui s'est déroulée entre janvier et juin 2018. Leur âge était en moyenne de 47,75 ans (25- 72), la surface brûlée de 42% (25- 67%). Chez tous les patients, deux zones similaires, à la culture bactérienne positive, étaient traitées par ATA (groupe 1) ou traitement conventionnel (groupe 2). La diminution des l'exsudation, de la douleur et de la charge bactérienne était plus rapide dans le groupe 1. Les cultures se négativaient en 3 jours (1- 6) dans le groupe 1 contre 8 (5- 9) dans le groupe 2. Cette étude montre l'intérêt du traitement local des infections de zones brûlées, ATA apparaissant dans ce cadre comme un traitement simple, sûr et peu onéreux.

Human postnatal dental pulp cells co-differentiate into osteoblasts and endotheliocytes: a pivotal synergy leading to adult bone tissue formation.

Stromal stem cells from human dental pulp (SBP-DPSCs) were used to study osteogenic differentiation in vitro and in vivo. We previously reported that SBP-DPSCs are multipotent stem cells able to differentiate into osteoblasts, which synthesize three-dimensional woven bone tissue chips in vitro. In this study, we followed the temporal expression pattern of specific markers in SBP-DPSCs and found that, when differentiating into osteoblasts, they express, besides osteocalcin, also flk-1 (VEGF-R2). In addition, 30% of them expressed specific antigens for endothelial cells, including CD54, von-Willebrand (domain 1 and 2), CD31 (PECAM-1) and angiotensin-converting enzyme. Interestingly, we found endotheliocytes forming vessel walls, observing that stem cells synergically differentiate into osteoblasts and endotheliocytes, and that flk-1 exerts a pivotal role in coupling osteoblast and endotheliocyte differentiation. When either SBP-DPSCs or bone chips obtained in vitro were transplanted into immunocompromised rats, they generated a tissue structure with an integral blood supply similar to that of human adult bone; in fact, a large number of HLA-1+ vessels were observed either within the bone or surrounding it in a periosteal layer. This study provides direct evidence to suggest that osteogenesis and angiogenesis mediated by human SBP-DPSCs may be regulated by distinct mechanisms, leading to the organization of adult bone tissue after stem cell transplantation.

The stem cell hypothesis in head and neck cancer.

Cancer stem cells (CSCs) are tumoral cells which have stem features such as self-renewal, high migration capacity, drug resistance, high proliferation abilities. In the last 10 years the pathological meaning and the existence of CSCs have been matter of discussion and a large number of articles have been published about the role that these cells play in the development and maintenance of the tumors. Head and neck squamous-cell carcinoma (HNSCC) is the sixth most common cancer worldwide: early diagnosis of high-risk premalignant lesions are high priorities for reducing deaths due to head and neck cancer. In the last years the CSCs hypothesis has been faced also for head and neck cancer, with the aim of a better comprehension of the tumor biology and an early diagnosis. The evidence that the development of a tumor comes from a small number of cells with stem-like characteristic, could bring too to the identification of therapies against these cellular target, fundamental for maintenance and progression of the lesion. Here, a literature review has been reported about the detection of supposed CSCs in head and neck cancer.

Cytotoxicity of demalonyl thyrsiflorin A, a semisynthetic labdane-derived diterpenoid, to melanoma cells.

Diterpenes are compounds with complex structure and due to their unique carbon skeleton and interesting biological activities, have been the focus of continuous studies for the development of new anticancer agents. The plants of the genus Calceolaria (Scrophulariaceae family), native of South America have also yielded several new diterpenes with the scopadulane skeleton, such as thyrsiflorin A. The present study was undertaken to investigate the effect of the semisynthetic compound, demalonyl thyrsiflorin A on human melanoma cells. In A375 cells compound demalonyl thyrsiflorin A showed a clear dose-response relationship in the range of 6.25-50µM concentrations. In addition, we demonstrated an apoptotic response after treatment of cancer cells with this semisynthetic phenolic labdane diterpene at 6.25 and 12.5µM concentrations that probably involves the reduction of Hsp70 expression and reactive oxygen species production. Alternatively, the inhibition of the caspase cascade at higher concentrations, 25 and 50µM, correlated with additional reactive oxygen species increase, probably switched the mode of demalonyl thyrsiflorin A-induced cell death from apoptosis to necrosis.

Enzymatic escharolysis with nexobrid® on partial thickness burn wounds: pre- and post-debridement histological assessment.

Enzymatic escharolysis is an innovative, non-surgical treatment method for severe burn patients as it allows very early, nontraumatic removal of necrotic tissue even on patients whose overall clinical conditions would mandate delaying traditional surgical escharectomy. The aim of this work was to examine aspects related to the "quality" of enzymatic debridement, which is inherently different from surgical debridement. To this end, biopsies harvested from partial thickness burn wounds, before and after enzymatic treatment, were histologically assessed. As is well known, surgical escharectomy removes the necrosis as well as some of its neighbouring healthy tissue, sharply and radically, leaving a perfectly clean and viable wound bed. On the other hand, enzymatic escharolysis is more selective, as it completely wipes out the necrotic portion while sparing unharmed and partially damaged tissue. In this study, only mid-deep partial thickness wounds were examined, and it was observed that partially damaged dermis was always spared by the lytic action. This dermis, however, showed some "homogenization" characteristics, had few vital skin annexes in it, and therefore looked very similar to the scaffold of dermal matrices currently available on the market. This scaffold should be safeguarded with a view to possibly achieving a more complete and functional spontaneous tissue regeneration. Conversely, if this dermal portion is mismanaged, it could desiccate, thus leading to the formation of a neo-eschar with unpredictable clinical evolution. Understanding how escharolysis actually works allowed us to extrapolate fruitful usage suggestions to optimize the procedure and fully exploit its potential.

La détersion enzymatique est une technique innovante non chirurgicale permettant l'ablation très précoce et non traumatique des tissus nécrosés même chez des patients dont l'état général nécessiterait de repousser une excision chirurgicale. Le but de ce travail était d'évaluer la « qualité ¼ du débridement enzymatique, par essence différent du traitement chirurgical. À cette fin, nous avons examiné histologiquement des biopsies réalisées avant et après détersion. Il est bien connu que la chirurgie emporte totalement et radicalement la nécrose et une partie du tissu environnant, laissant en place un tissu parfaitement propre et viable. Le débridement enzymatique est plus sélectif, emportant tout le tissu nécrosé sans affecter les tissus sains ou viables. Cette étude ne s'est intéressée qu'aux brûlures intermédiaires et nous avons observé que les régions saines étaient toujours préservées. Ce derme restant apparaît toutefois homogénéisé, avec peu d'annexes viables ce qui fait penser aux matrices des dermes artificiels actuellement commercialisés. Il doit être préservé afin de promouvoir une régénération tissulaire complète et fonctionnelle. Ainsi, si ce derme restant n'est pas correctement pris en charge, il peut se dessécher et aboutir à la formation d'un nouvel escarre, d'évolution imprévisible. Le compréhension du mécanisme exact de la lyse de la brûlure permet de développer des protocoles d'optimisation de la technique de lyse enzymatique.

Potential anticancer activity of lichen secondary metabolite physodic acid.

Secondary metabolites present in lichens, which comprise aliphatic, cycloaliphatic, aromatic and terpenic compounds, are unique with respect to those of higher plants and show interesting biological and pharmacological activities. However, only a few of these compounds, have been assessed for their effectiveness against various in vitro cancer models. In the present study, we investigated the cytotoxicity of three lichen secondary metabolites (atranorin, gyrophoric acid and physodic acid) on A375 melanoma cancer cell line. The tested compounds arise from different lichen species collected in different areas of Continental and Antarctic Chile. The obtained results confirm the major efficiency of depsidones. In fact, depsides atranorin and gyrophoric acid, showed a lower activity inhibiting the melanoma cancer cells only at more high concentrations. Whereas the depsidone physodic acid, showed a dose-response relationship in the range of 6.25-50 µM concentrations in A375 cells, activating an apoptotic process, that probably involves the reduction of Hsp70 expression. Although the molecular mechanism, by which apoptosis is induced by physodic acid remains unclear, and of course further studies are needed, the results here reported confirm the promising biological properties of depsidone compounds, and may offer a further impulse to the development of analogues with more powerful efficiency against melanoma cells.