328 research outputs found

    Calcium-phosphate glass-based bioresorbable fibre optics for light and drug delivery

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    Calcium-phosphate glasses (CPGs) are commonly used as scaffolds in tissue engineering. A novel formulation of optically transparent CPG has been recently developed to be used as an optical fibre for biomedical implantable devices. Its purpose is to combine the bioresorbability of CPGs with optical features, thus extending the applications of bioresorbable sensors for in-body monitoring or diagnostics. Modifications of the glass composition or post-treatments on the fibres can tailor the dissolution time and the interaction of the glass with different stimuli as well as with specific cells. The tested glasses both in bulk and fibre shapes showed good strength (from 200 to 350 MPa) with values that are lower than standard silica glass and much higher than common bioresorbable polymers. CPG fibres were also implanted in living rats for several weeks and no clinical signs of any adverse effect have been found. We will present our latest results on these subjects starting from the characterisation of the CPGs by means of dissolution tests, in-vitro, and ex-vivo experiments

    Delayed open conversion after endovascular abdominal aortic aneurysm: Device-specific surgical approach

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    none7Objectives: Despite several advances in endoluminal salvage for failed endovascular abdominal aortic repair (EVAR), in our experience an increasing number of cases necessitate delayed open conversion (dOC). Methods: EVAR patients requiring delayed (>30 days) conversion were prospectively collected in a computerized database including demographics, details of aortoiliac anatomy, procedural and clinical success, and postoperative complications. Results: Between 2005 and 2011, 54 patients were treated for aortic stent-graft explantation. Indications included 34 type I and III endoleaks, 13 type II endoleaks with aneurysm growth, 4 cases of material failures, and 3 stent-graft infections. All fit-for-surgery patients with type I/III endoleak underwent directly dOC. Different surgical approaches were used depending on the type of stent-graft. Overall 30-day mortality was 1.9%. Overall morbidity was 31% mainly due to acute renal failure (13 cases). Mean hospitalization was 6 days (range, 5-27 days). Overall survival at mean follow-up of 19 months was 78%. Conclusions: In recent years, the use of EVAR has increased dramatically, including in young patients regardless of their fitness for open repair. dOC after endovascular abdominal aortic aneurysm seems to be a lifesaving procedure with satisfactory initial and mid-term results. © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.Marone, E.M.; Mascia, D.; Coppi, D.; Tshomba, Y.; Bertoglio, L.; Kahlberg, A.; Chiesa, R.Marone, ENRICO MARIA; Mascia, D.; Coppi, D.; Tshomba, Y.; Bertoglio, L.; Kahlberg, A.; Chiesa, R

    Sentinel lymph node biopsy in porocarcinoma: A case reports

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    Introduction: Eccrine porocarcinoma (EPC) is a slow-growing carcinoma arising from the eccrine sweat glands. Based on its clinical presentation it can be confused with malignant and benign skin lesions, both. Histological examination is essential to formulate a correct diagnosis. Surgical excision with clear margins is the standard therapeutic approach while the role of sentinel lymph node biopsy (SNLB) remains controversial. Case presentation: The Authors report two cases of EPC of the lower limbs occurred in two women. Patients were treated by wide surgical excision of the lesion and SNLB. 6 months follow-up was disease free for both patients. Conclusion: Although a rare cutaneous tumor, EPC has to be taken into account in the differential diagnosis of malignant skin lesions because of its possible loco-regional aggressiveness and related morbidity. Among the available treatment options, surgical excision is considered the standard approach whereas the role of SNLB is controversial although the Authors discuss a possible usefulness for staging and diagnosis

    Modular e-learning for a practical skill in vascular surgery

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    Introduction: Working Time Regulations in Europe allied with the endovascular revolution require vascular surgeons to be innovative in achieving competence during their training period. We evaluated the feasibility of eLearning to teach the use of OsiriX for sizing and planning endovascular aortic aneurysm repairs. Materials and Methods: Eight blended learning modules were constructed, consisting of instructional PDFs, demonstration videos, CT angiogram downloads for individual practice and online support forums. These were delivered online over a nine-week period. The learning material encompassed an introduction to the OsiriX interface, the basic skills to use OsiriX for sizing and planning of aneurysm repairs and advanced techniques for reconstruction and online communication relating to imaging. Results: The course was successfully delivered and produced positive feedback from registered users. A high rate of dropouts occurred during the early phase. The design and implementation of a fully web-based course by full time clinicians utilising multimedia and user forums to teach vascular surgeons the performance of a practical skill is feasible. Conclusions: A modular instructional course offered online by vascular surgeons is feasible in teaching clinicians the use of OsiriX for 3D reconstructions of CT angiograms of aortic aneurysms. Shortening course duration may improve compliance. The instructional model is effective and well received by compliant learners

    Fenestrated-branched endovascular repair for distal thoracoabdominal aortic pathology after total aortic arch replacement with frozen elephant trunk

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    Objective: To report the outcomes of fenestrated-branched endovascular repair (FBEVAR) for thoracoabdominal aortic pathology after total aortic arch replacement with frozen elephant trunk (TAR+FET). Methods: Interrogation of prospectively maintained databases from four high-volume aortic centers identified consecutive patients treated with distal FBEVAR after prior TAR+FET between August 2013 and September 2020. The primary end point was 30-day/in-hospital mortality. Secondary end points were technical success, early clinical success, midterm survival, and freedom from reintervention. Data are presented as median (interquartile range). Results: A total of 39 patients (21 men; median age, 73 years [67-75 years]) with degenerative (n = 22) and postdissection thoracoabdominal aortic aneurysms (n = 17) (median diameter, 71 mm [61-78 mm]) were identified. Distal FBEVAR was intended in 27 patients (median interval, 9.8 months [6.2-16.6 months]), anticipated in 7, and unexpected in 5. A total of 31 patients had a two- (n = 24) or three-stage (n = 7) distal FBEVAR. Renovisceral target vessel preservation was 99.3% (145 of 146). Early primary and secondary technical success was 92% and 97%, respectively. Thirty-day mortality was 2.6% (n = 1; respiratory failure and spinal cord ischemia [SCI]). Six survivors also developed SCI, which was associated with complete (n = 4) or partial recovery (n = 2) at hospital discharge. No patients required renal replacement therapy or suffered a stroke. Early clinical success was 95%. Median follow-up was 30.5 months (23.7-49.7 months). Eleven patients required 16 late reinterventions. Estimated 3-year survival and freedom from reintervention were 84% ± 6% and 63% ± 10%, respectively. Conclusions: Distal FBEVAR after prior TAR+FET is associated with high technical success and low early mortality. The risk of SCI is significant although the majority of patients demonstrate full or partial recovery before hospital discharge. Midterm patient survival is favorable, but there remains a high requirement for late reintervention. FBEVAR represents an acceptable alternative to distal open thoracoabdominal aortic aneurysm repair

    Peri-Operative Management of Patients Undergoing Fenestrated-Branched Endovascular Repair for Juxtarenal, Pararenal and Thoracoabdominal Aortic Aneurysms: Preventing, Recognizing and Treating Complications to Improve Clinical Outcomes

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    The advent and refinement of complex endovascular techniques in the last two decades has revolutionized the field of vascular surgery. This has allowed an effective minimally invasive treatment of extensive disease involving the pararenal and the thoracoabdominal aorta. Fenestrated-branched EVAR (F/BEVAR) now represents a feasible technical solution to address these complex diseases, moving the proximal sealing zone above the renal-visceral vessels take-off and preserving their patency. The aim of this paper was to provide a narrative review on the peri-operative management of patients undergoing F/BEVAR procedures for juxtarenal abdominal aortic aneurysm (JAAA), pararenal abdominal aortic aneurysm (PRAA) or thoracoabdominal aortic aneurism (TAAA). It will focus on how to prevent, diagnose, and manage the complications ensuing from these complex interventions, in order to improve clinical outcomes. Indeed, F/BEVAR remains a technically, physiologically, and mentally demanding procedure. Intraoperative adverse events often require prolonged or additional procedures and complications may significantly impact a patient’s quality of life, health status, and overall cost of care. The presence of standardized preoperative, perioperative, and postoperative pathways of care, together with surgeons and teams with significant experience in aortic surgery, should be considered as crucial points to improve clinical outcomes. Aggressive prevention, prompt diagnosis and timely rescue of any major adverse events following the procedure remain paramount clinical needs

    Heterogeneity Governs 3D-Cultures of Clinically Relevant Microbial Communities

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    The intrinsic heterogeneity of bacterial niches should be retained in in vitrocultures to represent the complex microbial ecology. As a case study,mucin-containing hydrogels -CF-Mu3Gel - are generated by diffusion-inducedgelation, bioinspired on cystic fibrosis (CF) mucus, and a microbial nichechallenging current therapeutic strategies. At breathing frequency, CF-Mu3Gelexhibits aGâ€ČandGâ€Čâ€Čequal to 24 and 3.2 Pa, respectively. Notably, CF-Mu3Gelexhibits structural gradients with a gradual reduction of oxygen tensionacross its thickness (280–194ÎŒmol L−1). Over the culture period, a steepdecline in oxygen concentration occurs just a few millimeters below theair–mucus interface in CF-Mu3Gel, similar to those of CF airway mucus.Importantly, the distinctive features of CF-Mu3Gel significantly influencebacterial organization and antimicrobial tolerance in mono- and co-cultures ofStaphylococcus aureusandPseudomonas aeruginosathat standard culturesare unable to emulate. The antimicrobial susceptibility determined inCF-Mu3Gel corroborates the mismatch on the efficacy of antimicrobialtreatment between planktonically cultured bacteria and those in patients.With this example-based research, new light is shed on the understanding ofhow the substrate influences microbial behavior, paving the way for improvedfundamental microbiology studies and more effective drug testing anddevelopment

    Modest agreement between magnetic resonance and pathological tumor regression after neoadjuvant therapy for rectal cancer in the real world.

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    Magnetic resonance imaging (MRI) is routinely used for preoperative tumor staging and to assess response to therapy in rectal cancer patients. The aim of our study was to evaluate the accuracy of MRI based restaging after neoadjuvant chemoradiotherapy (CRT) in predicting pathologic response. This multicenter cohort study included adult patients with histologically confirmed locally advanced rectal adenocarcinoma treated with neoadjuvant CRT followed by curative intent elective surgery between January 2014 and December 2019 at four academic high-volume institutions. Magnetic resonance tumor regression grade (mrTRG) and pathologic tumor regression grade (pTRG) were reviewed and compared for all the patients. The agreement between radiologist and pathologist was assessed with the weighted k test. Risk factors for poor agreement were investigated using logistic regression. A total of 309 patients were included. Modest agreement was found between mrTRG and pTRG when regression was classified according to standard five-tier systems (k = 0.386). When only two categories were considered for each regression system, (pTRG 0-3 vs pTRG 4; mrTRG 2-5 vs mrTRG 1) an accuracy of 78% (95% confidence interval [CI] 0.73-0.83) was found between radiologic and pathologic assessment with a k value of 0.185. The logistic regression model revealed that "T3 greater than 5 mm extent" was the only variable significantly impacting on disagreement (OR 0.33, 95% CI 0.15-0.68, P = .0034). Modest agreement exists between mrTRG and pTRG. The chances of appropriate assessment of the regression grade after neoadjuvant CRT appear to be higher in case of a T3 tumor with at least 5 mm extension in the mesorectal fat at the pretreatment MRI

    Magnetite NPs@C with highly-efficient peroxidase-like catalytic activity as an improved biosensing strategy for selective glucose detection

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    This work reports the novel application of carbon-coated magnetite nanoparticles (mNPs@C) as catalytic nanomaterial included in a composite electrode material (mNPs@C/CPE) taking advantages of their intrinsic peroxidase-like activity. The nanostructured electrochemical transducer reveals an improved enhancement of the charge transfer for redox processes involving hydrogen peroxide. Likewise, mNPs@C/CPE demonstrated to be highly selective even at elevated concentrations of ascorbic acid and uric acid, the usual interferents of blood glucose analysis. Upon these remarkable results, the composite matrix was further modified by the addition of glucose oxidase as biocatalyst in order to obtain a biosensing strategy (GOx/mNPs@C/CPE) with enhanced properties for the electrochemical detection of glucose. GOx/mNPs@C/CPE exhibit a linear range up to 7.5 x 10-3 mol.L-1 glucose, comprising the entirely physiological range and incipient pathological values. The average sensitivity obtained at –0.100 V was (1.62 ± 0.05)x 105 nA.L.mol-1 (R2 = 0.9992), the detection limit was 2.0 x 10-6 M while the quantification limit was 6.1 x 10-6 mol.L-1. The nanostructured biosensor demonstrated to have an excellent performance for glucose detection in human blood serum even for pathological values.submittedVersionFil: Arana, Mercedes. Universidad Nacional de CĂłrdoba. Facultad de MatemĂĄtica, AstronomĂ­a y FĂ­sica; Argentina.Fil: Arana, Mercedes. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de FĂ­sica Enrique Gaviola; Argentina.Fil: Tettamanti, Cecilia Soledad. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂ­micas. Departamento de FisicoquĂ­mica; Argentina.Fil: Tettamanti, Cecilia Soledad. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de Investigaciones en FisicoquĂ­mica de CĂłrdoba; Argentina.Fil: Bercoff, Paula Gabriela. Universidad Nacional de CĂłrdoba. Facultad de MatemĂĄtica, AstronomĂ­a y FĂ­sica; Argentina.Fil: Bercoff, Paula Gabriela. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Instituto de FĂ­sica Enrique Gaviola; Argentina.Fil: RodrĂ­guez, Marcela Cecilia. Universidad Nacional de CĂłrdoba. Facultad de Ciencias QuĂ­micas. Departamento de FisicoquĂ­mica; Argentina.Fil: RodrĂ­guez, Marcela Cecilia. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnica. Instituto de Investigaciones en FisicoquĂ­mica de CĂłrdoba; Argentina.Otras Ciencias FĂ­sica
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