Morphological characteristics on a Scanning Electron Microscope of generated hyaline cartilage tissue from adipose mesenchymal stem cells, on Polycaprolactone scaffolds

Cartilage regeneration is of great interest to the medical community, given the prevalence of osteocartilage defects in the population coupled with the tissue’s low intrinsic self-repair potential. A recently new FDA approved biomaterial and 3D-printing technology provided us the opportunity to fabricate tailor made scaffolds. We used collagen coated and uncoated scaffolds to develop hyaline cartilage from adipose mesenchymal stem cells (ADMSCs). The aim of this study is to present the scaffolds’ morphological characteristics, as observed on a Scanning Electron Microscope (SEM) of generated cartilage tissue and to compare the two types of scaffolds. Cylindrical shaped PCL scaffolds, 10mm in diameter, were fabricated. ADMSCs were harvested and were cultivated on PCL scaffolds. Half of the scaffolds were treated with collagen I by coating. After 26 days in culture, the scaffolds were examined by SEM. Visualization was succeeded on the top and bottom surfaces and on the cross sections of each scaffold. At day 26, scaffolds revealed extensive colonization and viability of ADMSCs, with concurrent depositions of extracellular matrix. SEM images show that surfaces were covered with a significant amount of material with a glossy, transparent appearance, indicating the development of regenerated cartilage, more apparent on the coated scaffolds. Cultured cells demonstrated aligned direction on the scaffolds' fibers and the ECM that was produced connected the pores of the scaffolds by building apparent bridges between them. The penetration of cells was limited in the coated scaffold. We used 3D printing technology for PCL scaffold production, towards a cartilaginous implant development. SEM images provide us visualization of the scaffolds with the newly developed cartilage tissue and demonstrate that the scaffolds’ purpose for chondrogenesis was served successfully in all cases and PCL displayed good biocompatibility. Collagenation of scaffolds led to a higher density of cells on the surfaces but also to a limited penetration within, not fully serving the purpose of a 3D culture

Translational research for nasal septum cartilage regeneration with chondrocytes derived from differentiated human adipose mesenchymal stem cells

Η εργασία αφορά στη μεταφραστική έρευνα ιστοτεχνολογίας και συγκεκριμένα στη δημιουργία ανθρώπινου ρινικού διαφράγματος με τη χρήση ηλεκτρονικά υποβοηθούμενου σχεδιασμού και τρισδιάστατης εκτύπωσης τρισδιάστατου (3D) πορώδους ικριώματος χιτοζάνης/ζελατίνης (CAD/CAM). Το ικρίωμα θα χρησιμοποιηθεί για να αποικιστεί από χρονδροκύτταρα που προκύπτουν από διαφοροποιημένα μεσεγχυματικά κύτταρα ανθρώπου προερχόμενα από λιπώδη ιστό (Adipose Tissue Mesenchymal Stem Cells-AD- MSCs). Η όλη διαδικασία επιτυγχάνεται με τη χρήση βιοαντιδραστήρα.Τα μεσεγχυματικά κύτταρα είναι πολυδύναμα βλαστοκύτταρα που μπορούν να απομονωθούν από το μυελό των οστώνκαι το λιπώδη ιστό. Τα κύτταρα αυτά έχουν τη δυνατότητα να διαφοροποιούνται, υπό εργαστηριακές συνθήκες, σε οστεοκύτταρα, χονδροκύτταρα, και λιποκύτταρα. Στην παρούσα μελέτη ανθρώπινα μεσεγχυματικά κύτταρα απομονώθηκαν από λιπώδη ιστό και καλλιεργήθηκαν in vitro. Η έκφραση των αντιγόνων επιφανείας CD90, CD73, σε συνδυασμό με την απουσία του μάρτυρα CD45 επιβεβαιώνουν την επιτυχή απομόνωση μεσεγχυματικών βλαστικών κυττάρων, με χρήση κυτταρομετρίας ροής. Έπειτα από 21 ημέρες από την επαγωγή στοχευόμενης διαφοροποίησης τα βλαστοκύτταρα διαφοροποιήθηκαν σε χονδροκύτταρα και χαρακτηρίστηκαν ιστολογικά με χρώση κυανού της τολουιδίνης και μοριακά με RTPCR για δείκτες διαφοροποίησης όπως η αγκρεκάνη. Με τη χρήση του τρισδιάστατου εκτυπωτή δημιουργήθηκε υπό κλίμακα ικρίωμα ρινικού χόνδρου από PLA. Η διαδικασία θα ολοκληρωθεί με την εκτύπωση του υπό διερεύνηση υλικού χιτοζάνης/ζελατίνης σε 3D ικρίωμα και αφού εμποτιστεί με χονδροκύτταρα θα μεταφερθεί στον βιοαντιδραστήρα.Mesenchymal stem cells (MSCs) are multipotent cells isolated from various tissues, mainly from the bone marrow and adipose tissue. Their ability to differentiate into osteoblasts, chondrocytes or adipocytes renders them a promising clinical tool for injury repair and tissue regeneration. In the current study, MSCs were isolated from human adipose tissue (hAD-MSCs) and were triggered to differentiate into chondrocytes in vitro. Expression of mesenchymal stem cell markers, such as CD90 and CD73, in combination with the absence of hematopoietic markers, such as CD45, proves via flow cytometry the successful isolation of MSCs. Histologic staining with Toluidine blue and real time PCR analysis for the expression of the chondrogenic marker aggrecan (ACAN) verified the successful chondrogenic differentiation of AD-MSCs. Using Poly Lactic-Acid as scaffolding material, a three-dimensional scaffold with customized architecture, controlled porosity and interconnected porous structure was fabricated using 3D printing. The produced scaffold represents the morphology of the nasal septum cartilage. We aspire, to see this scaffold with the differentiated chondrocytes and culture the complex under the appropriate micoenvironmental conditions of a bioreactor system in order to regenerate a potential cartilage transplant. This in vitro study expands the potentials of human AD-MSCs to be used in clinic for alleviation of cartilage defects and tissue engineering in Greece and worldwide

Design of a laboratory bioreactor for engineering articular cartilage based on 3D printed nasal septum-like scaffolds

«Η εκφύλιση των χόνδρων είναι μια σοβαρή πάθηση που επηρεάζει μεγάλο μέρος του πληθυσμού σε όλο το ηλικιακό φάσμα. Επί του παρόντος χρησιμοποιούνται διάφορες τεχνικές αποκατάστασης για μικρής έκτασης βλάβες όπως η αρθροπλαστική απόξεσης και ο υποχονδρικός τρυπανισμός, οι οποίες δεν μπορούν να επιδιορθώσουν βλάβες μεγαλύτερης έκτασης. Η Αναγεννητική Ιατρική προωθεί την Μηχανική Ιστών στο προσκήνιο των σύγχρονων μηχανικών τεχνικών, συνδυάζοντας καινοτόμα βιοσυμβατά υλικά, νέες μεθόδους μηχανικής ιστών όπως η τεχνολογία 3D εκτύπωσης και βιοδιαδικασίες που αποσκοπούν στην δημιουργία ποιοτικών μοσχευμάτων για εκτεταμένες βλάβες των χόνδρων. Κατάλληλο κυτταρικό περιβάλλον για δημιουργία ιστών μπορεί να επιτευχθεί με την ανάπτυξη αυτών των μοσχευμάτων σε βιοαντιδραστήρες. O κάθε βιοαντιδραστήρας χρησιμοποιεί διαφορετικές αρχές καλλιέργειας, και ορισμένοι από αυτούς όπως οι μικτού τύπου και οι βιοαντιδραστήρες διαπότισης επιστρατεύουν την άσκηση μηχανικών δυνάμεων επί του ικριώματος ώστε να επιτευχθεί μεγάλη κυτταρική πυκνότητα και ενισχυμένες μηχανικές ιδιότητες που οδηγούν στην δημιουργία καλύτερης ποιότητας χόνδρου. Αυτές οι ιδιαιτερότητες των βιοαντιδραστήρων μπορούν να αποτελέσουν εφαλτήριο κατασκευής εργαστηριακών βιοαντιδραστήρων, για την καλλιέργεια 3D εκτυπωμένων ρινικών διαφραγμάτων ως ένα λειτουργικό παράδειγμα υαλώδους χόνδρου».Cartilage degeneration is a severe disease affecting a significant part of the population at all ages. Various treatment modalities are currently used for small-sized cartilage defects, such as abrasion arthroplasty and subchondral drilling, but fail to repair larger-scale damages. Regenerative Medicine pushes Tissue Engineering (TE) to the forefront of modern engineering techniques combining novel biocompatible materials, new tissue engineering methods, like 3D printing technology and bioprocesses trying to create quality transplants for large cartilage defects. The appropriate cell environment for engineered tissues can be achieved through growth of the tissue-engineered constructs into bioreactors. Each bioreactor uses different principles for culturing processes, and some of them mostly mixed and perfusion bioreactors, use different kind of mechanical forces on the scaffold to achieve high cell densities, enhanced mechanical properties leading to better quality of engineered cartilage. These advantageous particularities can be used to create a laboratory bioreactor design, for culturing 3D printed nasal septum cartilage as a working example of hyaline cartilage

Body image, emotional intelligence and quality of life in peritoneal dialysis patients

Background: End-stage-renal-disease is one of the most common chronic diseases, and peritoneal dialysis constitutes one of the replacement therapies. The aim of this study was to investigate the views of patients on peritoneal dialysis regarding their body image, to assess their quality of life and level of emotional intelligence. Methods: A cross-sectional study was performed with structured questionnaires. The sample of the study was the patients undergoing peritoneal dialysis and monitored by the nephrology clinics of 7 public hospitals in Greece. Results: A total of 102 completed questionnaires were collected and analyzed (68% response rate). The participants showed moderate degree of body-image dysphoria (mean = 1.29, SD = 0.94), moderate levels of emotional intelligence and experienced moderate quality of life. According to the statistical analysis, women reported worse body image (p = 0.013) and university graduates showed higher levels of emotionality (p = 0.016). The correlations between the quality of life questionnaire subscales and demographic characteristics revealed statistically significant relationships between marital status and the Physical Functionality subscale, where unmarried people had a better quality of life in this subscale (p = 0.042) and between postgraduate/doctoral degree holders and the subscale Patient Satisfaction (p = 0.035). Also, statistically significant relationships were found between occupation and the Social Interaction subscale, where those engaged in household activities and were unemployed (p = 0.022) showed better quality of life. Participants living in semi-urban areas had better quality of life on the subscale Burden of Kidney Disease (p = 0.034). Conclusion: ESRD patients on peritoneal dialysis suffer significant limitations related to disease and treatment modality. According to our findings, these affect both their body image as well as their quality of life. Improvement in emotional intelligence is the factor which plays an important mediating role in improving both body image and quality of life in patients on peritoneal dialysis

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

What are the Risk Factors Responsible for the Delay in Diagnosis of Acute Appendicitis in Children? Eleven-year Research from a Single Institution

Introduction: We conducted a retrospective analysis of 602 children operated on for acute appendicitis (AA) in our department between 1/2007 and 12/2017.Aim: The aim of this study was to identify factors that are related to a delay in diagnosing AA in children. Furthermore, we’d like to strengthen our previous preliminary results by a) adding gender as a new factor and b) studying a much larger population.Materials and methods: The time that elapsed from the onset of symptoms to the surgical intervention was associated with gender, age, obesity, use of antibiotics prior to diagnosis, and the initial examination by a paediatric surgeon or another physician. Univariate and multivariate logistic regression method (backward method) was applied.Results: The diagnosis of AA was delayed by at least 48 hours in 287 patients (group A, 47.7%) and was made within 48 hours in 315 patients (group B, 52.3%). In multivariate model we noticed that boys who were examined by a paediatric surgeon and didn’t take antibiotics had decreased odds of having length of diagnostic period >48 hours, girls who received antibiotics compared to girls who do not use antibiotics are almost 12 times more likely to have length of diagnostic period >48 hours, the very young age has а main effect оn the diagnostic delay and girls who have been examined by other physician compared to females who have been examined by paediatric surgeon have decreased odds of having length of diagnostic period >48 hours.Conclusions: Therefore, physicians examining children with abdominal pain must keep in mind the multiple causes of diagnostic delay that may exist alone or in combination, and which can lead to serious complications and lengthen the hospital stay. Performing repeated examinations and asking for advice from a specialist specifically for children who are a special category of patients, in areas where it is rather impossible to use imaging techniques, could be the key to correctly diagnosing and treating AA

Low Dose Administration of Glutamate Triggers a Non-Apoptotic, Autophagic Response in PC12 Cells

Background/Aims: Increasing amounts of the neurotransmitter glutamate are associated with excitotoxicity, a phenomenon related both to homeostatic processes and neurodegenerative diseases such as multiple sclerosis. Methods: PC12 cells (rat pheochromocytoma) were treated with various concentrations of the non-essential amino acid glutamate for 0.5-24 hours. The effect of glutamate on cell morphology was monitored with electron microscopy and haematoxylin-eosin staining. Cell survival was calculated with the MTT assay. Expression analysis of chaperones associated with the observed phenotype was performed using either Western Blotting at the protein level or qRT-PCR at the mRNA level. Results: Administration of glutamate in PC12 cells in doses as low as 10 μM causes an up-regulation of GRP78, GRP94 and HSC70 protein levels, while their mRNA levels show the opposite kinetics. At the same time, GAPDH and GRP75 show reduced protein levels, irrespective of their transcriptional rate. On a cellular level, low concentrations of glutamate induce an autophagy-mediated pro-survival phenotype, which is further supported by induction of the autophagic marker LC3. Conclusion: The findings in the present study underline a discrete effect of glutamate on neuronal cell fate depending on its concentration. It was also shown that a low dose of glutamate orchestrates a unique expression signature of various chaperones and induces cell autophagy, which acts in a neuroprotective fashion