A Low Cost Face Mask for Inhalation Anaesthesia in Rats

Inhalation anaesthesia in small laboratory rodents has become very popular in Biomedical Research. A  common method to deliver volatile anesthetic agents is through a face mask. The main disadvantage of this  method is the exposure of personnel to anaesthetic agents. The authors describe a low-cost face mask, made  with materials commonly accessible in the operating room that can be connected to an anaesthetic machine  eliminating personnel exposure to hazardous levels of anaesthetic agents and allowing for effective adjustments  to the anaesthetic depth.

Fatal venous air embolism in swine during surgical procedure

Η εμβολή με αέρα της φλεβικής κυκλοφορίας είναι ένα σχετικά σπάνιο γεγονός που μπορεί να συμβεί τόσο κατάτην εκτέλεση απλών χειρουργικών χειρισμών όσο και κατά τη διάρκεια μεγάλων χειρουργικών επεμβάσεων. Αν και υπάρχειπληθώρα βιβλιογραφικών αναφορών για τον άνθρωπο, η αναφορά περιστατικών σε ζώα είναι περιορισμένη. Περιγράφεται περιστατικόφλεβικής εμβολής με αέρα, που παρατηρήθηκε κατά τη διάρκεια χειρουργικής επέμβασης, για την τοποθέτηση μοσχεύματοςαπό πολυτετραφλουοροαιθυλένιο μεταξύ κοινής καρωτίδας και έξω σφαγιτιδας φλέβας σε χοίρο. Πριν και μετά τηντοποθέτηση του μοσχεύματος πραγματοποιήθηκε λήψη μετρήσεων της ενδοαγγειακής πίεσης και των μεταβολών της διαμέτρουτης έξω σφαγιτιδας φλέβας, κεντρικά και περιφερικά της αναστόμωσης του μοσχεύματος, καθώς και μετρήσεις των μεταβολώντης ροής τόσο στην κοινή καρωτίδα όσο και στην έξω σφαγιτιδα φλέβα, κεντρικά και περιφερικά των αντίστοιχων αναστομώσεων.Το ζώο παρέμενε σταθερό αιμοδυναμικά για δυο ώρες και σαράντα λεπτά, οπότε αιφνιδίως παρατηρήθηκε ραγδαία πτώσητου κορεσμού του αίματος σε οξυγόνομε ταυτόχρονη μείωση της καρδιακής συχνότητας. Παρά τους χειρισμούς που έγιναν από τη χειρουργική ομάδα, μετά από δέκα λεπτά το ζώο κατέληξε. Κατά τη νεκροτομική εξέταση παρατηρήθηκε συγκέντρωση μεγάλης ποσότητας αέρα στη δεξιά καρδιά, στην πρόσθια και την οπίσθια κοίλη φλέβα, στην πνευμονική αρτηρία, καθώς και στις στεφανιαίες αρτηρίες. Παρόλο που πιθανολογείται ότι η είσοδος του αέρα έγινε από την αναισθητική μηχανή ή το σημείο της αναστόμωσης, ο τρόπος εισόδου παραμένει άγνωστος.Air embolism can occur after minor invasive procedures, as well as during major surgical operations. Reports of air embolism cases in veterinary literature are not very often, although it is considered that it happens more often than it is recognized. During a surgical procedure in swine, for the creation of a fistula of PTFE graft between the right common carotid artery and the right jugular vein under general anaesthesia, the animal died due to massive venous air embolism. Although it is supposed that the air was possibly inserted through the anaesthetic machine or through the anastomosis, the exact mechanism of the air insertion remains unknown

The anti-inflammatory effects of exercise training promote atherosclerotic plaque stabilization in apolipoprotein E knockout mice with diabetic atherosclerosis

Physical exercise is the cornerstone of cardiovascular disease treatment. The present study investigated whether exercise training affects atherosclerotic plaque composition through the modification of inflammatory-related pathways in apolipoprotein E knockout (apoE-/-) mice with diabetic atherosclerosis. Forty-five male apoE-/- mice were randomized into three equivalent (n=15) groups: control (CO), sedentary (SED), and exercise (EX). Diabetes was induced by streptozotocin administration. High-fat diet was administered to all groups for 12 weeks. Afterwards, CO mice were euthanatized, while the sedentary and exercise groups continued high-fat diet for 6 additional weeks. Exercising mice followed an exercise program on motorized-treadmill (5 times/week, 60 min/session). Then, blood samples and atherosclerotic plaques in the aortic root were examined. A considerable (P<0.001) regression of the atherosclerotic lesions was observed in the exercise group (180.339±75.613 x103μm2) compared to the control (325.485±72.302 x103μm2) and sedentary (340.188±159.108 x103μm2) groups. We found decreased macrophages, matrix metalloproteinase-2 (MMP-2), MMP-3, MMP-8 and interleukin-6 (IL-6) concentrations (P<0.05) in the atherosclerotic plaques of the exercise group. Compared to both control and sedentary groups, exercise training significantly increased collagen (P<0.05), elastin (P<0.001), and tissue inhibitor of matrix metalloproteinase-2 (TIMP-2) (P<0.001) content in the atherosclerotic plaques. Those effects paralleled with increased fibrous cap thickness and less internal elastic lamina ruptures after exercise training (P<0.05), while body-weight and lipid parameters did not significantly change. Plasma MMP-2 and MMP-3 concentrations in atherosclerotic tissues followed a similar trend. From our study we can conclude that exercise training reduces and stabilizes atherosclerotic lesions in apoE-/- mice with diabetic atherosclerosis. A favorable modification of the inflammatory regulators seems to explain those beneficial effects

Efficient liver gene transfer with foamy virus vectors

Liver gene transfer offers hope for the correction of genetic and acquired disorders. Efficient gene transfer in large animals can be obtained with hydrodynamic gene transfer (HGT), a method that can achieve sufficient levels of gene delivery. To test the relative efficiency between plasmid versus foamy virus (FV) vector-based liver gene transfer efficiency, we applied HGT in 4 juvenile pigs, using the same plasmid backbone, either naked or coated as a FV vector particle. Gene transfer efficiency and persistence of expression was assayed by PCR and real-time PCR, respectively, at 1 week and at 1 month after the infusions. HGT was tolerated well and no adverse reactions were observed. Plasmid injections resulted in no detectable DNA sequences at 1 week. At the 1 month time point, 2/15 liver sections analyzed were positive for the presence of plasmid DNA. When FV vectors were infused under identical conditions, 18/28 (64.3%) of the liver samples were positive for the presence of vector sequences, and the expression levels reached 29.7 and 15.6% of the endogenous GAPDH levels in the injected and the adjacent liver lobes. Our results indicate that medium-term therapeutic levels of gene expression can be obtained with FV vectors, an effect that can be attributed to the potential of the HGT procedure and to the natural affinity of FV vectors for hepatocytes

Decellularized human umbilical artery used as nerve conduit

Treatment of injuries to peripheral nerves after a segmental defect is one of the most challenging surgical problems. Despite advancements in microsurgical techniques, complete recovery of nerve function after repair has not been achieved. The purpose of this study was to evaluate the use of the decellularized human umbilical artery (hUA) as nerve guidance conduit. A segmental peripheral nerve injury was created in 24 Sprague-Dawley rats. The animals were organized into two experimental groups with different forms of repair: decellularized hUA (n = 12), and autologous nerve graft (n = 12). Sciatic faction index and gastrocnemius muscle values were calculated for functional recovery evaluation. Nerve morphometry was used to analyze nerve regeneration. Results showed that decellularized hUAs after implantation were rich in nerve fibers and characterized by improved Sciatic Functional index (SFI) values. Decellularized hUA may support elongation and bridging of the 10 mm nerve gap. © 2018 by the authors

Evaluation of a decellularization protocol for the development of a decellularized tracheal scaffold

Background/Aim: Currently, there are no effective solutions for the treatment of advanced disorders of the airways. The aim of this study was to assess the efficacy of a decellularization protocol of the trachea in order to produce a functional scaffold for serious clinical respiratory disorders. Materials and Methods: Rat tracheas were decellularized using a protocol which included constituents with chemical action. Histological analysis was performed in order to evaluate the efficacy of decellularization. Genetic material was assayed and the toxicity of the decellularization protocol was assessed. Results: Histological analysis confirmed the removal of the nuclear and cellular components of the decellularized tissue, as well as maintenance of the extracellular matrix. DNA quantification showed removal of the genetic material. Furthermore, the decellularization protocol did not induce any cytotoxicity on tracheaI tissue. Conclusion: The decellularization protocol was effective for tracheal decellularization. The final aim, in the future, would be to create a tissue-engineered airway which will be able to function normally. © 2019 International Institute of Anticancer Research. All Rights Reserved

Acute histological changes of the lung after experimental Fontan circulation in a swine model

Background: Histological changes of the lungs were studied after the establishment of a modified total cavopulmonary connection (TCPC) without the use of cardiopulmonary bypass (CPB) or other means of temporary bypass on a swine model. Material/Methods: 8 open chest-anesthetized pigs Landrace x Large White pigs (mean weight 43kg, mean age 4.5 months) underwent TCPC by the use of an appropriate size Y-shaped conduit connecting the superior and inferior caval veins (end-to-end anastomosis) to the pulmonary trunk (end-to-side anastomosis). After sternotomy, a wedge resection of the lung parenchyma was performed at baseline. Hemodynamic stability was sustained after TCPC establishment and 2 hours later another wedge resection of the lung was performed (from the same anatomic area). Histological studies were conducted by hematoxylin and eosin staining. Results: All samples (n=8) at baseline were consistent with normal lung parenchyma. After the establishment of TCPC, all samples (n=8) revealed moderate mononuclear infiltration adjacent to pulmonary alveoli and bronchioles, findings compatible with bronchiolitis. Conclusions: In a normal swine model, 2 hours after the establishment of Fontan circulation without the use of CPB, pathologic examination of the lungs revealed bronchiolitis. Further research is needed to clarify these findings and the potential implications to the Fontan circulation, either immediate or long-term

The beneficial effects of a direct thrombin inhibitor, dabigatran etexilate, on the development and stability of atherosclerotic lesions in apolipoprotein e-deficient mice

Purpose Dabigatran etexilate (DE) constitutes a novel, direct thrombin inhibitor. Regarding the association of thrombin with atherogenesis, we assessed the effects of DE on the development and stability of atherosclerotic lesions in apolipoprotein-E deficient (ApoE-/-) mice. Materials-methods Fifty male ApoE-/- mice were randomized to receive western-type diet either supplemented with DE 7.5 mg DE/g chow) (DE-group, n025) or matching placebo as control (CO-group, n025) for 12 weeks. After this period, all mice underwent carotid artery injury with ferric chloride and the time to thrombotic total occlusion (TTO) was measured. Then, mice were euthanatized and each aortic arch was analyzed for the mean plaque area, the content of macrophages, elastin, collagen, nuclear factor kappaB (NF?B), vascular cell adhesion molecule-1 (VCAM-1), matrix metalloproteinase-9 (MMP-9) and its inhibitor (TIMP-1). Results DE-group showed significantly longer TTO compared to CO-group (8.9±2.3 min vs 3.5±1.1 min, p<0.001) and the mean plaque area was smaller in DE-group than CO-group (441.00±160.01×103μm2 vs 132.12±32.17× 103μm2, p<0.001). Atherosclerotic lesions derived from DE-treated mice showed increased collagen (p00.043) and elastin (p00.031) content, thicker fibrous caps (p<0.001) and reduced number of internal elastic lamina ruptures per mm of arterial girth (p<0.001) when compared to COgroup. Notably, DE treatment seemed to promote plaque stability possibly by reducing concentrations of NF?B, VCAM-1, macrophages and MMP-9 and increasing TIMP-1 within atherosclerotic lesions (p<0.05). Conclusions DE attenuates arterial thrombosis, reduces lesion size and may promote plaque stability in ApoE-/- mice. The plaque-stabilizing effects of chronic thrombin inhibition might be the result of the favorable modification of inflammatory mechanisms. © Springer Science+Business Media, LLC 2012