Phytoplankton dynamics and chemical characteristics of the euphotic zone were measured from 1998-2000 (an El Niño/La Niña cycle) at the 5 major stations along Line P. Near-shelf and offshore stations exhibited low seasonality in chlorophyll and moderate seasonality in particulate organic carbon (POC) production. During the 1998 El Niño, June was characterized by low chlorophyll and POC productivity due to nitrate depletion. In contrast, during the 1999 La Niña, and in 2000, higher POC productivity and nitrate occurred in June. During 1999, chlorophyll and POC productivity were similar to 1998 in late summer. Near-shelf biomass was highest in June and lowest in Feb. for the near-shelf stations. High nitrate, low chlorophyll (HNLC) stations had the highest chlorophyll in Feb. followed by June. The coccolithophore assemblage was usually numerically dominated by Emiliania huxleyi, particularly in June. Along the transect, coccolithophore abundance was much higher in June during the 1998 El Niño than in the 1999 La Niña, with Aug./Sept. abundance of both years being very low. Higher abundances were measured along the transect in June and the late summer of 2000 with sporadic ‘blooms’ of >1000 cells ml⁻¹ at some stations. Particulate inorganic carbon (PIC) production was high along the transect during June 1998, and low during both winters, June 1999 and during late summers of 1998 and 1999. There was an increase in diatom biomass and >20 µm POC production during the 1998 El Niño, specifically in the farthest offshore HNLC stations, yet diatoms were rarely found to dominate total phytoplankton biomass or production. However, there were some sporadic examples of anomalously high diatom biomass (carbon and abundance) as well as >20 µm POC production, specifically at P12 in Aug./Sept 2000. The same major diatom species were found throughout Line P (near-shelf, P16, and HNLC). Integrated silica production measured by ³²Si ranged from 0.2 to 4.7 mmol Si m⁻² d⁻¹ between 1999-2000. Silicic acid and nitrate were never limiting at all stations in Feb. and generally increased in concentration along Line P during all seasons.

Bibliography: leaves [280]-301 / xiv, 317 leaves : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Pathology, 1984

Diss. (sammanfattning) Stockholm : Karol. inst., 2004. / Härtill 4 uppsatser.

Thesis (M.S.)--University of Tennessee Health Science Center, 2006. / Title from title page screen (viewed on October 8, 2007 ). Research advisor: Edward Harris, Ph.D. Document formatted into pages (xiii, 156 p. : ill.) Vita. Abstract. Includes bibliographical references (p. 137-147).

Το αντικείμενο της παρούσας μεταπτυχιακής διατριβής ειδίκευσης ήταν η μελέτη των φυσικοχημικών και μηχανικών ιδιοτήτων παθολογικά αλλοιωμένων ανθρώπινων μηνίσκων. Οι μηνίσκοι είναι ινοχόνδρινοι μηνοειδείς δίσκοι που παρεμβάλλονται μεταξύ των αρθρικών επιφανειών του μηριαίου κονδύλου και της κνημιαίας γλύνης. Αποτελούνται ως επί το πλείστον από ίνες κολλαγόνου και χονδροκύταρα. Περιέχουν ακόμα γλυκοσαμινογλυκάνες, ελλαστίνη και DNA. Συμβάλλουν καθοριστικά στη σωστή λειτουργία της άρθρωσης καθώς είναι επιφορτισμένοι με λειτουργίες, όπως η προστασία των αρθρικών επιφανειών από τη φθορά, η λίπανση και η σταθεροποίηση της άρθρωσης. Η σημαντικότερη ίσως μεταβολική νόσος των μηνίσκων είναι η χονδρασβεστίωση (chondrocalcinosis) κατά την οποία παρατηρείται ανάπτυξη ανόργανων αλάτων στην επιφάνεια ή/και στο σώμα του ιστού. Για τη μελέτη των ιδιοτήτων των παθολογικά αλλοιωμένων ανθρώπινων μηνίσκων χρησιμοποιήθηκαν τεχνικές μηχανικής και φυσικοχημικής ανάλυσης. Με Δυναμική Μηχανική Ανάλυση επιχειρήθηκε να αξιολογηθεί η επίδραση των διαφόρων τύπων παθολογικών αλλοιώσεων στις δυναμικές μηχανικές ιδιότητες των ιστών. Οι ασβεστοποιημένοι ιστοί και οι εναποθέσεις τους μελετήθηκαν με φασματοσκοπικές τεχνικές RAMAN, FT-RAMAN, FT-IR καθώς επίσης και με απεικονιστικές τεχνικές οπτικής μικροσκοπίας, σαρωτικής μικροσκοπίας ηλεκτρονίων (SEM) και μικροσκοπίας ατομικής δύναμης (AFM). Επιπλέον, για πρώτη φορά έγινε διασύγκριση της ικανότητας τριών διαφορετικών διατάξεων RAMAN (FT-RAMAN: 1064 nm, Dispersion RAMAN: 633 nm και Dispersion RAMAN: 325 nm) να εντοπίσουν την παρουσία εναποθέσεων στους ιστούς. Στην παρούσα μελέτη εξετάστηκαν 63 μηνισκικά μοσχεύματα από οστεοαρθριτικούς ασθενείς οι οποίοι υποβλήθηκαν σε ολική αρθροπλαστική γόνατος στο Περιφερειακό Πανεπιστημιακό Νοσοκομείο Πατρών. Τα μοσχεύματα αυτά εξετάστηκαν από ιστοπαθολόγο και διαγνώστηκαν οι παθολογικές αλλοιώσεις που έφερα καθένας από αυτούς. Με βάση τα ιστοπαθολογικά αποτελέσματα έγινε κατηγοριοποίηση των δοκιμίων και συσχέτιση των αποτελεσμάτων αυτών με τα αποτελέσματα των προαναφερθέντων τεχνικών. Από τα αποτελέσματα της δυναμικής μηχανικής ανάλυσης φάνηκαν μικρές αλλά όχι στατιστικά σημαντικές διαφοροποιήσεις μεταξύ ασβεστοποιημένων μηνίσκων και μηνίσκων που παρουσίαζαν μυξωματοειδή εκφυλισμό και κύστες (σύμφωνα με τα αποτελέσματα της ιστοπαθολογικής εξέτασης). Τα αποτελέσματα της περιθλασιμετρίας ακτίνων Χ των ασβεστοποιημένων ιστών έδειξαν παρουσία μείγματος τρικλινούς και μονοκλινούς διένυδρου πυροφωσφορικού ασβεστίου (CPPD) υψηλής κρυσταλλικότητας καθώς και μικροκρυσταλλικές εναποθέσεις απατιτικής σύστασης (HAP). Οι τεχνικές μικροσκοποίας (οπτική, SEM και AFM) επιβεβαίωσαν τον παραπάνω ισχυρισμό αποκαλύπτοντας το χαρακτηριστικό τρόπο ανάπτυξης κάθε τύπου εναπόθεσης. Τα αποτελέσματα της φασματοσκοπικής ανάλυσης με χρήση των τεχνικών RAMAN – FT-RAMAN – και FT-IR έδειξαν την παρουσία επίσης χαρακτηριστικών κορυφών του CPPD και του HAP. Οι εναποθέσεις από CPPD ανιχνεύθηκαν στο 82.6 % των ασβεστοποιημένων δειγμάτων (19 στα 23) ενώ από απατίτη στο 17.4% (4 στα 23) Aναφορικά με τα RAMAN, επισημαίνεται ότι ανεξάρτητα από το μήκος κύματος που χρησιμοποιήθηκε και παρά την ισχυρή μπάντα φθορισμού που επεδείκνυαν τα φάσματα, οι χαρακτηριστικές κορυφές των εναποθέσεων ήταν εμφανείς. / The aim of the present master thesis study was the physicochemical and biomechanical characterization of pathological human menisci. Menisci are semilunar shaped fibrocartilaginous tissues that lie between the femoral condyle and tibia plateau. They mainly consist of collagen fibers and chondrocytes. Additionally glycosaminoglycans, elastin and DNA are present in the tissue. Menisci play an important role in the good function of human knee joint by distributing the applied loads, contributing to the joint’s stability and lubricating the joint’s area. The most common metabolic meniscal lesion is the chondrocalcinosis where inorganic phases of calcium or sodium salts are deposited in/on the tissue. Pathologically altered human menisci were studied by mechanical and physicochemical analysis techniques. Dynamic Mechanical Analysis was used to investigate the effects of degeneration lesions on the dynamic mechanical properties of the tissue. Calcified tissues and the corresponding encrustations were studied by spectroscopic techniques such as RAMAN, FT-RAMAN, FT-IR as well as imaging techniques such as optical microscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). Moreover, for the first time a comparison of the ability of three different RAMAN setups (FT-RAMAN: 1064 nm, Dispersion RAMAN: 633 nm and Dispersion RAMAN:325 nm) to detect calcification on the tissues was performed. The clinical sample comprised of 63 menisci with histopathologicaly confirmed alterations that were surgically extracted from osteoarthritic patients due to total knee arthroplasty in the University Hospital of Patras. Samples were classified according to the histopathological evaluation and a correlation of histopathological with mechanical or spectroscopic findings was attempted. Dynamic mechanical analysis results showed small but no statistically significant difference between the group of calcified and the group of mucoid and cystic degenerated tissues (as determined after histopathological examination) X-ray diffraction analysis of the menisci encrustations revealed highly crystallized depositions of triclinic and monoclinic Calcium Pyrophosphate Dihydrate (CPPD) and some samples with poorly crystallized apatitic depositions (HAP). Microscopic techniques (optical, SEM and AFM) confirmed the presence of CPPD and HAP and in addition revealed information regarding their growth mechanism.The results of spectroscopical analysis using RAMAN – FT-RAMAN and FT-IR showed also the characteristic peaks of the inorganic phase (CPPD or HAP) presented in/on the tissue. CPPD encrustations were detected in 82.6 % (19 of 23) of the calcified samples while apatite in 17.4 % (4 of 23). Moreover, it is notable that all RAMAN setups showed the characteristic peaks of CPPD and HAP regardless of the excitation source and the strong fluorescence band.

Η χειρουργική καταρράκτη διαμέσου μικρής τομής με τη χρήση αναδιπλούμενων ενδοφθάλμιων φακών είχε ως αποτέλεσμα την εμφάνιση μιας νέας επιπλοκής˙ της θόλωσης των φακών. Αρκετοί παράγοντες έχουν ενοχοποιηθεί για την αιτιολόγηση του φαινομένου. Μεταξύ αυτών αναφέρονται η μετεγχειρητική φλεγμονή, η χρήση διαλυμάτων πλύσης και ιξωδοελαστικών υλικών, η σιλικόνη, τα λιπαρά οξέα που εμπεριέχονται στο υδατοειδές υγρό. Προηγούμενες αναφορές έχουν αποδώσει την αιτία του φαινομένου της θόλωσης των ενδοφακών στην ασβεστοποίηση. Για τη μελέτη του φαινομένου της ασβεστοποίησης έχουν κατά καιρούς χρησιμοποιηθεί in vivo μοντέλα. Στα μοντέλα αυτά γίνονται απλοποιήσεις ώστε να προσομοιώνονται όσο το δυνατόν καλύτερα οι φυσικοχημικές συνθήκες των βιολογικών ρευστών που είναι σε επαφή με τους αντίστοιχους ιστούς. Ακριβείς θερμοδυναμικές μετρήσεις και μελέτες της κινητικής στις συνθήκες αυτές είναι δυνατόν να δώσουν χρήσιμες πληροφορίες όσον αφορά στην εμφάνιση και εξέλιξη με το χρόνο του φαινομένου της ασβεστοποίησης διάφορων ιστών ή οργάνων. Στην παρούσα εργασία, και με στόχο να προσομoιωθούν οι συνθήκες του προσθίου θαλάμου κατά την επαφή του φακού με το υδατοειδές υγρό, κατασκευάσθηκε από πολυαμίδιο διπλότοιχος θερμοστατούμενος αντιδραστήρας συνολικού όγκου 10 ml. Ο πυθμένας και το άνω μέρος του αντιδραστήρα ήταν από γυαλί, έτσι ώστε το σύνολο να είναι δυνατόν να διευθετηθεί στο έδρανο οπτικού μικροσκοπίου διερχομένου φωτός, προκειμένου να είναι δυνατή η συνεχής παρατήρηση των δοκιμίων. Το συνθετικό υδατοειδές υγρό παρασκευάστηκε με τριπλά απεσταγμένο νερό στο οποίο διαλύθηκαν συγκεκριμένες ποσότητες κρυσταλλικών αλάτων έτσι ώστε η τελική σύσταση να αντιστοιχεί στη σύσταση του υδατοειδούς υγρού, σύμφωνα με την βιβλιογραφία. Η ροή του συνθετικού υδατοειδούς υγρού προς τον αντιδραστήρα γινόταν με τη βοήθεια αντλίας σύριγγας ρυθμιζόμενης παροχής. Ο ρυθμός ροής ήταν 0.2ml/h όπως και στην περίπτωση της ροής του υδατοειδούς υγρού στον πρόσθιο θάλαμο του φακού. Εντός του αντιδραστήρα τοποθετήθηκαν σε ειδικό δειγματοφορέα τρεις υδρόφιλοι ακρυλικοί ενδοφθάλμιοι φακοί (Α, Β και Γ) με περιεκτικότητα σε νερό 26% κ.β. Η μελέτη του συστήματος έγινε σε συνθήκες αντιπροσωπευτικές του oργανισμού, δηλαδή pH=7.4 και θερμοκρασία=37˚C. Η παρακολούθηση των φακών με τη βοήθεια του οπτικού μικροσκοπίου, το οποίο ήταν εφοδιασμένο με βιντεοκάμερα, γινόταν καθημερινά και λαμβάνονταν φωτογραφίες για περαιτέρω ανάλυση. Οι φακοί Α, Β και Γ απομακρύνθηκαν από τον αντιδραστήρα στους πέντε, εννιά και δώδεκα μήνες αντίστοιχα, με σκοπό να μελετηθεί τόσο η επιφάνειά τους όσο και το εσωτερικό του πολυμερικού υλικού. Τα μορφολογικά χαρακτηριστικά των εναποθέσεων εξετάσθηκαν και μελετήθηκαν με τη βοήθεια ηλεκτρονικού μικροσκοπίου σάρωσης ενώ η χημική σύσταση των κρυσταλλιτών ταυτοποιήθηκε με μικροανάλυση με φασματοσκοπία ενεργειακής διασποράς ακτίνων Χ (EDX). Περαιτέρω ταυτοποίηση έγινε με φασματοσκοπικές μεθόδους (φασματοσκοπία Raman) και με περίθλαση ακτίνων Χ. Η τελευταία τεχνική, λόγω της μικρής αναλογίας κρυσταλλικό στερεό/πολυμερές, δεν έδωσε αποτελέσματα και ως εκ τούτου δεν είναι δυνατόν να χρησιμοποιηθεί ως τεχνική ταυτοποίησης. Η χρήση της προϋποθέτει διαφορετική γεωμετρία δείγματος-ανιχνευτή. Ο υπερκορεσμός είναι η κινητήρια δύναμη για την έναρξη της πυρηνογένεσης και της εν συνεχεία ανάπτυξης των σταθερών πυρήνων σε κρυσταλλίτες φωσφορικού ασβεστίου. Δεδομένου του ότι, η συγκέντρωση ασβεστίου του υδατοειδούς υγρού είναι χαμηλή, περίπου η μισή της αντίστοιχης του πλάσματος, υπετέθη, ότι κάθε αιτία τοπικής αύξησης του ασβεστίου και του φωσφόρου, εντός του υδατοειδούς υγρού, μπορεί ενδεχομένως να καταλήξει σε δυστροφική ασβεστοποίηση των φακών. Η μελέτη των φακών και η αξιολόγηση του φαινομένου στο πειραματικό μοντέλο που δημιουργήθηκε στην παρούσα εργασία έγιναν σε συνθήκες σταθερού υπερκορεσμού, δεδομένου του ότι υπήρξε συνεχής ανανέωση του υδατοειδούς υγρού εντός του αντιδραστήρα, κατά τρόπο κατάλληλο ώστε να επιτευχθεί ικανοποιητική προσομοίωση των in vivo συνθηκών. Τα περισσότερα βιολογικά ρευστά, περιλαμβανομένου του υδατοειδούς υγρού είναι υπέρκορα ως προς διάφορες φάσεις αλάτων φωσφορικού ασβεστίου, οι οποίες κατά σειρά μειωμένης διαλυτότητας είναι το διένυδρο φωσφορικό ασβέστιο (CaHPO42H2O, DCPD), το φωσφορικό τριασβέστιο (Ca3(PO4)2, TCP), το φωσφορικό οκτασβέστιο (Ca8H2(PO4)65 H2O, OCP) και ο υδροξυαπατίτης (Ca10(PO4)6(OH)2, HAP). Η διαλυτότητα των κρυσταλλικών αυτών φάσεων και ο υπερκορεσμός των διαλυμάτων καθορίζονται από παράγοντες όπως η θερμοκρασία, το pH κτλ. Η τάση για καταβύθιση και σχηματισμό συγκεκριμένης φάσης κρυσταλλικού ασβεστίου εντός του υδατοειδούς υγρού, μπορεί να καθοριστεί από το διάγραμμα διαλυτότητας και εξαρτάται από το pH του διαλύματος και από τη θερμοκρασία. Σε υψηλές τιμές υπερκορεσμού και σε διαλύματα με υψηλό pH, έχει ταυτοποιηθεί ο σχηματισμός και η σταθεροποίηση πρόδρομων φάσεων, ενώ σε συνθήκες χαμηλού υπερκορεσμού και μειωμένου pH σχηματίζεται απ’ ευθείας ΗΑΡ. Η διαδικασία της ασβεστοποίησης των ενδοφακών επηρεάζεται από παράγοντες όπως η δομή και η κατεργασία του πολυμερούς υλικού βάσης (μήτρα), η παρουσία πόρων και η περιεκτικότητά του σε νερό. Τα ακρυλικά πολυμερή διαθέτουν επιφανειακές ιονιζόμενες καρβοξυλικές ομάδες, η παρουσία των οποίων σε ιονισμένη μορφή (-COO-, pH>4) ευνοεί τη συμπλοκοποίηση με ιόντα ασβεστίου του υδατοειδούς υγρού. Τα επιφανειακά αυτά σύμπλοκα είναι πιθανόν να λειτουργούν ως ενεργά κέντρα για την πυρηνογένεση και περαιτέρω ανάπτυξη των κρυστάλλων του φωσφορικού ασβεστίου. Επιπλέον, η ασβεστοποίηση φαίνεται ότι είναι έντονη στους υδρόφιλους φακούς, λόγω της υψηλότερης ενυδάτωσης των υδρόφιλων πολυμερών, η οποία έχει ως αποτέλεσμα την υψηλότερη επιφανειακή συγκέντρωση των ιονισμένων ομάδων (ομάδες / m2) και συνεπώς και των επιφανειακών συμπλόκων- ενεργών κέντρων για την κρυσταλλική ανάπτυξη. Στην παρούσα εργασία και στο in vitro μοντέλο με τη χρησιμοποίηση ενός υδρόφιλου φακού, διαπιστώθηκε ότι η διαδικασία της ασβεστοποίησης λαμβάνει χώρα στο εσωτερικό των φακών, στην πολυμερική μήτρα. Οι σχηματισμοί στο πειραματικό μοντέλο εντοπίσθηκαν στο εσωτερικό των ενδοφακών και με την πάροδο του χρόνου, διαπιστώθηκε ότι μετατοπίζονταν προς τα επιφανειακά στρώματα των φακών. Επίσης, οι εναποθέσεις εμφανίσθηκαν ως γραμμικό μέτωπο παράλληλο προς την γραμμή της επιφάνειας των ενδοφακών. Τόσο η μορφολογική εξέταση των εναποθέσεων στο εσωτερικό όσο και η φασματοσκοπική τους ταυτοποίηση, έδειξε ότι η σύστασή τους ήταν εξ’ ολοκλήρου ΗΑΡ, χωρίς να αποκλείεται και ο σχηματισμός πρόδρομης φάσης OCP, δεδομένου του ότι βρέθηκαν κρυσταλλίτες οι οποίοι μορφολογικά παρουσιάζουν μεγάλη ομοιότητα στη φάση αυτή. Η ερμηνεία της διαπίστωσης του γεγονότος ότι η ασβεστοποίηση λαμβάνει χώρα στο εσωτερικό των ενδοφακών, συνίσταται στο ότι η διάχυση των ιόντων Ca2+ και PO43- εντός της πολυμερικής μήτρας, προχωρεί μέχρι τέτοιο βαθμό ώστε να δημιουργούνται στο εσωτερικό του πολυμερούς συνθήκες τοπικού υπερκορεσμού, κατάλληλες για τη δημιουργία των αντίστοιχων κρυστάλλων. Με την υπόθεση ότι οι τιμές των συντελεστών διάχυσής των ιόντων Ca2+ και PO43- εντός της πολυμερικής μήτρας, είναι της αυτής τάξεως μεγέθους είναι δυνατόν να εξηγηθεί και η εμφάνιση μετώπου συγκέντρωσης των. Η συσσώρευση των ιόντων τα οποία αποτελούν τα δομικά συστατικά του ΗΑΡ συνεχίζεται μέχρις ότου επιτευχθεί μία κρίσιμη τιμή υπερκορεσμού. Σε αυτό το σημείο σχηματίζονται οι πυρήνες και λαμβάνει χώρα η κρυσταλλική ανάπτυξη με τον ερχομό και συσσώρευση επιπρόσθετων ιόντων. Η ασβεστοποίηση των υδρόφιλων ενδοφακών είναι μία προοδευτική και συνεχώς εξελισσόμενη διαδικασία μετά την εμφύτευσή τους και όσο περισσότερο αφήνεται να εξελιχθεί τόσο αυξάνεται η πυκνότητα των εναποθέσεων στο εσωτερικό των φακών. Η επιφάνεια μπορεί να προσβληθεί μόνο σε όψιμες φάσεις και αρκετά χρόνια μετά την εμφύτευση των φακών. Στο σημείο αυτό κρύσταλλοι μπορεί να αναπτυχθούν και σε σημεία, στα οποία έχουν δημιουργηθεί στην επιφάνεια του πολυμερούς σχισμές και χαρακιές. Το θέμα της έναρξης της ασβεστοποίησης (εσωτερικό ή επιφάνεια) χρειάζεται περαιτέρω διερεύνηση. Σύμφωνα με κάποιες αναφορές στη βιβλιογραφία, προτείνεται ότι η έναρξη της ασβεστοποίησης γίνεται στην επιφάνεια των ενδοφακών. Στην παρούσα εργασία, σε συνθήκες χαμηλού υπερκορεσμού, ανάλογες με τις αντίστοιχες υγιούς υδατοειδούς υγρού η ασβεστοποίηση έλαβε χώρα στο εσωτερικό της πολυμερικής μήτρας του ενδοφακού και σε χρόνο και με τρόπο ο οποίος μπορεί να εξηγηθεί από τη (βραδεία) διάχυση των δομικών ιόντων του ΗΑΡ στο εσωτερικό της πολυμερικής μήτρας. Τα ευρήματα και τα συμπεράσματα από την ολοκλήρωση της πειραματικής διαδικασίας με τη χρήση υδρόφιλων ενδοφακών με υδρόφοβη επικάλυψη δείχνουν ότι το θέμα της έναρξης της ασβεστοποίησης˙ εσωτερικό ή επιφάνεια φαίνεται ότι εκτός από τον υπερκορεσμό, υψηλός ή χαμηλός, εξαρτάται και από τη φύση του πολυμερούς του φακού˙ υδρόφιλη ή υδρόφοβη. Τα ευρήματα δείχνουν ότι η υδρόφιλη φύση ευνοεί τη διάχυση, ενώ το υδρόφοβο υλικό την έναρξη της ασβεστοποίησης στην επιφάνεια του φακού. Τα ευρήματα δείχνουν ότι η υδρόφιλη φύση ευνοεί τη διάχυση, ενώ το υδρόφοβο υλικό την έναρξη της ασβεστοποίησης στην επιφάνεια του φακού. Συμπερασματικά, η όψιμη μετεγχειρητική ασβεστοποίηση των ενδοφακών συνιστά σοβαρή επιπλοκή και αιτία μείωσης της όρασης. Λόγω του ότι η διαδικασία και η εκδήλωση του φαινομένου έχει καθυστερημένη έναρξη, είναι σημαντική η μακροχρόνια και προσεκτική παρακολούθηση αυτών των ασθενών. Αρκετοί οφθαλμίατροι δεν είναι ενήμεροι ως προς αυτήν την κλινική οντότητα και αναγνωρίζοντάς την βοηθούν ώστε να μην υποβάλλουν τους ασθενείς σε ανώφελες επεμβάσεις. Η χειρουργική εξαίρεση του φακού συνιστά τη μοναδική θεραπευτική προσέγγιση, καθώς ασθενείς με ασβεστοποιημένους φακούς παρουσιάζουν σταδιακή μείωση της οπτικής τους οξύτητας και καμία περίπτωση αυτόματης υποστροφής δεν έχει παρατηρηθεί. / Small incision cataract surgery with foldable IOL implantation resulted in a new postoperative complication, IOL opacification. Various factors implicated in the phenomenon have been suggested, including inflammation, irrigation solutions and viscosurgical devices, silicone and fatty acids contamination. There is increasing evidence that IOL opacification is due to calcification. Modeling in vivo processes by reliable and reproducible in vitro methods is of key importance to understand the underlying mechanisms. Precise thermodynamic calculations of equilibrium speciation in combination with kinetics measurements at conditions simulating the eye environment are expected to yield mechanistic information concerning the formation of calcium phosphate deposits. In the present contribution we have developed an experimental approach for the investigation of the mechanism of calcification of hydrophilic acrylic IOLs. A double walled thermostated reactor was constructed, volume totaling 10 ml made of polyamide. The reactor had glass windows on top and bottom to allow for the direct observation of the IOL specimens in situ using an optical microscope combined with an image analysis system. In the external wall of the reactor, water supplied from a thermostat was circulated in order to maintain the temperature at 37.0  0.2˚C, while in the interior of the reactor constant flow of a simulated aqueous humor solution (SAH) was ensured with the help of a syringe pump. The SAH solution was introduced in the reactor in an once flow mode at a flow rate of 0.2ml/h, simulating the in vivo flow in the anterior chamber, where aqueous humor is fully renewed within 2 hours. Hydrophilic acrylic IOLs (A, B and C) in triplicate, made of Poly-HEMA with 26% water content were placed in a special holder. The observation of IOLs was done in situ daily by optical microscopy, for the assessment of the opacification progress. Five months after the initiation of the experiment, Lens A was removed in order to be inspected, both at the surface and in the interior. The morphology of the deposits was examined using Scanning Electron Microscopy (SEΜ). The composition of the deposits was identified by microanalysis with Energy Dispersive x-ray Spectroscopy (EDS). Lens B was removed on the ninth month, while Lens C was inspected one year after the onset of the experiment. Similar studies including SEM and EDS analysis were used for the investigation of both those lenses. Investigation showed deposits of calcium phosphate crystallites in the interior of opacified IOLs. These deposits however, were not observed on the IOL’s surface. The thermodynamic driving force for the formation of a salt from solution is the difference between the chemical potentials of the salt in solution from the equilibrium. Taking into account that the calcium concentration in normal aqueous humor is low, about half of the respective value in blood serum, it may be assumed that any cause of localized increase in calcium and phosphorus might result in dystrophic calcification. The experiments in the present work were done at conditions of practically constant supersaturation, since the solution in the experimental reactor was flown once through thus providing a reasonable simulation of the in vivo conditions. Heterogeneous nucleation, an almost ubiquitous phenomenon, is initiated at impurity sites and foreign surfaces in contact with supersaturated solutions. The induction time preceding the formation of nuclei of solids which grow to crystals depends on several factors, including temperature, pH, ionic strength, solution composition which determine the thermodynamic driving force for the formation of the solid phase. Biological fluids like blood serum or aqueous humor are supersaturated with respect to a number of different phases of calcium phosphate salts, in the order of decreasing solubility: Calcium phosphate dehydrate (CaHPO42H2O, DCPD), Tricalcium phosphate (Ca3(PO4)2, TCP), Octacalcium phosphate (Ca8H2(PO4)65 H2O, OCP) and Hydroxyapatite (Ca10(PO4)6(OH)2, HAP). HAP is the thermodynamically stable phase while the rest of the crystalline phases are precursors which may be formed and/or stabilized in supersaturated solutions depending on the conditions in the supersaturated solutions. The tendency for particular calcium phosphate phases to form in supersaturated solutions may be estimated from the solubility phase diagrams of calcium phosphates. Unstable precursor phases, if formed, they convert through hydrolytic processes to the thermodynamically most stable. The process of biomaterial calcification seems moreover to be influenced by factors such as polymer structure, polymer porosity and water content. The ionizable surface hydroxyl groups (present in the carboxyl functional groups) available on the surface of the acrylic polymers may act as sites for nucleation and growth of mineral phase, through surface complexation with calcium ions. The presence of larger numbers of –COOH groups on the polymers accelerate the process of Ca-P overgrowth. The higher extend of hydration in hydrophilic materials leads to higher ionization of the surface functional groups, thus promoting calcification through the formation of complexes with Ca2+ ions. The higher calcification incidents observed in IOLs with higher water content has been attributed to this fact. The polar functional groups (-COO) on the surface of the polymeric matrix of IOLs result in the significant increase in electron density and the subsequent reduction of the interfacial energy between the polymer and aqueous solution. The energy barrier to diffusion of calcium and phosphate species from the bulk solution to the substrate is also reduced, through the formation of surface complexes, which favor the accumulation of Ca2+ and PO43- ions, thus promoting calcification. Our in vitro model experiments have shown that IOL’s calcification is a process initiated at the interior of the IOLs tested. SEM investigation in combination with EDS microanalysis, confirmed the presence of HAP crystallites with sizes less than 100nm. Raman spectroscopy analyses of the opacified lenses corroborated the findings for HAP formation in the interior of the polymeric matrix. X-Ray diffraction measurements failed to identify the presence of minerals apparently because of the low content (by mass) of solid in the polymeric matrix. Supersaturation of the aqueous humor, with respect to calcium phosphate, is the driving force a necessary condition for nucleation of Ca-P salts. The formations observed in our experimental set-up which simulated closely in vivo conditions, were found exclusively in the interior of the IOLs. The solid deposits formed linear fronts parallel to the lens surfaces, advancing with time. It may be suggested therefore that the deposits fronts is the result of diffusion of Ca2+, PO43- and OH- ions through the polymer matrix in contact with the polymer. Assuming similar values for the diffusion coefficients of Ca2+, PO43- and OH- ions in the gel (bulk polymer) material the formation of linear deposits fronts may be explained from the formation of the supersaturated solutions at a depth in which a critical supersaturation was reached. At this point calcium phosphate nuclei form and grow with the arrival of additional ions. IOL’s calcification is an ongoing process after IOL implantation, and the longer the process proceeds, the density of the deposits in the interior of the IOL increases. In all of the cases surface was free of deposits and the distortions that were observed are thought to be due to changes in polymer structure in the IOL’s interior. Surface can be affected only in late phases of calcification and many years after IOL implantation. At this stage crystals may outgrow especially at places in which the polymer’s surface has developed fissures. The issue of calcification’s process initiation (interior or surface) needs further investigation. Reports in the literature, suggest that calcification is initiated on the surface of the IOL. In our experiment where low supersaturation conditions have been achieved, diffusion was favored resulting in calcification at the interior of the polymeric matrix. Investigation and analysis of IOLs with hydrophobic surface confirmed that the issue of calcification`s process initiation is more over influenced by factors others than supersaturation conditions, such as the hydrophilic or hydrophobic nature of the IOLs surface. The experimental analysis proved that hydrophilic IOLs favor ions diffusion while hydrophobic material limits calcification process on the surface. In conclusion, late postoperative IOL opacification causes a severe loss of visual acuity. Because calcification process appears to be of delayed onset it is important to be vigilant in the long-term follow-up of these patients. Many ophthalmologists are not aware of this clinical problem and recognizing this phenomenon will help prevent patients from undergoing useless procedures. IOL exchange is the only therapeutic approach, in such patients, as patients with calcified IOLs have gradual deterioration of their visual acuity and no case of spontaneous recovery has been observed.

Introdução: A indicação de endarterectomia carotídea (EAC) profilática em conjunto com revascularização miocárdica (CRM) permanece assunto indefinido. A cirurgia conjunta é amplamente difundida, mas seus resultados vêm sendo questionados. Método: Coorte retrospectiva de 691 pacientes submetidos à CRM, escolhidos aleatoriamente. Avaliação realizada para dados gerais, presença de lesão carotídea, ateromatose aórtica, desfechos neurológicos e óbito. Resultados: Dentre 691 pacientes submetidos à CRM, 16 pacientes apresentaram acidentes vasculares cerebrais (AVC). Dentre esses, 11 pacientes (68.75%) apresentaram AVC localizados em áreas não compatíveis com as lesões carotídeas, sendo três deles com lesões calcificadas na aorta ascendente. Os pacientes com estenose carotídea apresentaram taxa similar de eventos neurológicos totais, AVC e óbito, comparados com pacientes sem estenose carotídea. Um subgrupo de 35 pacientes com estenose carotídea foi submetido à cirurgia coronariana com (14 pacientes) ou sem (21 pacientes) cirurgia de carótida, obtendo-se taxa de eventos neurológicos totais, AVC e óbito estatisticamente semelhantes. Os pacientes com calcificações aórticas apresentaram risco maior de eventos neurológicos (14,58% versus 6.55%, p=0.011), AVC (3,12% versus 2,18%, p=0,47) e óbito (8,33% versus 4,37%, p=0.12). Discussão: Os eventos neurológicos após CRM correlacionam-se com ateromatose aórtica. Os AVC freqüentemente não têm relação linear com a estenose carotídea. Estratégias para minimizar embolia da aorta podem diminuir as taxas de intercorrências neurológicas. / Introduction: The management of patients with simultaneous disease of carotid and coronary arteries is controversial. Studies showed that aortic calcifications might play a role in postoperative stroke at coronary artery bypass graft (CABG), carotid lesions may not be as important as previously considered. Method: A retrospective cohort of a randomly selected group (including elective and emergency operations) of 691 patients submitted to CABG was reviewed for general data, neurological complications and mortality. Results: Among 691 CABGs 16 patients had postoperative stroke. Among these, 11 patients (68.75%) had strokes not matching carotid lesions and anatomic presentation, three of those had detectable aortic calcifications. The patients with critical carotid stenosis had similar rates of neurological events, stroke and death as compared to patients without. The patients with aortic calcifications presented a higher risk of neurological events (14.58% versus 6.55%, p=0.011), stroke (3.12% versus 2.18%, p=0.47) and death (8.33% versus 4.37%, p=0.12). Discussion: The postoperative neurological events after CABG can be related to aortic calcifications. The strokes after coronary bypass may occur independently of the carotid lesions. Strategies to prevent aortic emboli may help preventing many post-operative strokes.

Introdução: As doenças cardiovasculares (DCV) são a principal causa de morte no mundo, sendo a doença arterial coronária (DAC) a mais comum das DCV, juntamente com acidente vascular cerebral. O cálcio das artérias coronárias é um marcador da DAC subclínica (assintomática) e é preditivo de eventos coronários futuros. Vários fatores de risco cardiovascular contribuem para o desenvolvimento da calcificação da artéria coronária (CAC). Adicionalmente, os fatores dietéticos podem influenciar no processo de aterosclerose e CAC. Objetivo: Avaliar a CAC e sua associação com fatores de risco cardiovascular e ingestão dietética em homens assintomáticos vivendo em comunidade. Métodos: Estudo transversal. A amostra consistiu de 150 homens assintomáticos com idades entre 50 e 70 anos (idade média 58,2 ± 5,3 anos), que foram submetidos à tomografia computadorizada multidetectores (TCMD). A aterosclerose subclínica foi avaliada pela CAC de acordo com o método de Agatston, sendo os escores de cálcio classificados como ≤10 (sem evidência e CAC mínima) e >10 (CAC moderada e aumentada). A ingestão dietética foi avaliada através do Registro de Consumo Alimentar (RCA). O modelo multivariado de Regressão de Modified Poisson foi utilizado para avaliar os fatores de risco cardiovascular independentemente associados com a CAC moderada/aumentada, sendo estimados os efeitos do consumo de diversos nutrientes na prevalência de CAC moderada/aumentada ajustado para ingestão calórica e fatores de risco para CAC, através da razão de prevalências e intervalo de 95% de confiança. Resultados: A presença de CAC (escore de cálcio >0) foi identificada em 59,3% dos participantes. Na análise multivariada, os fatores independentemente associados com a CAC moderada/aumentada foram a história familiar (HF) de DAC prematura (RP=1,39; IC95% 1,03-1,88, p=0,029) e a atividade física (AF) <150 minutos/semana (RP=1,40; IC95% 1,01-1,93; p=0,045). O consumo de alguns nutrientes, também, mostrou-se associado à CAC moderada/aumentada, como o menor consumo de carboidratos (p=0,021) e o maior consumo de lipídeos (p=0,006), após o ajuste do modelo para a quantidade de calorias. Com a inclusão no modelo dos fatores de risco cardiovascular e escolaridade, os nutrientes associados à prevalência da CAC moderada/aumentada foram: carboidratos percentual (RP=0,98; IC95% 0,96-0,99; p=0,040), lipídeos percentual (RP=1,04; IC95% 1,01-1,07; p=0,005) e ácidos graxos saturados (AGS) percentual (RP=1,08; IC95% 1,02-1,14; p=0,013). Conclusões: Nesta amostra de adultos e idosos assintomáticos vivendo em comunidade, fatores de risco cardiovascular como HF de DAC prematura e baixa intensidade de AF estiveram associados, de forma independente, com a calcificação coronária moderada a aumentada. Analisando os fatores dietéticos, uma maior ingestão de lipídeos totais e de gorduras saturadas mostraram-se associadas com escores mais elevados de CAC, enquanto que a ingestão maior de carboidratos, em detrimento aos lipídeos, associou-se com escores mais baixos de CAC. Nossos resultados sugerem que esses fatores de risco devem ser mais considerados na avaliação clínica do risco cardiovascular global do paciente. / Introduction: Cardiovascular diseases (CVD) are the main cause of death in the world, being the coronary artery disease (CAD) the most common CVD. The calcium of the coronary arteries is a marker for subclinical (asymptomatic) CAD, and is predictive of future coronary events. A number of cardiovascular risk factors account for coronary artery calcification (CAC). In addition, dietary factors may influence the process of atherosclerosis and CAC. Goal: To assess CAC and its association with cardiovascular risk factors and dietary intake in community-dwelling asymptomatic men. Method: Cross-sectional study. The sample included 150 asymptomatic men with age ranging between 50 and 70 years (mean age 58.2 ± 5.3 years) submitted to multidetector computed tomography (MDCT). Subclinical atherosclerosis was measured by CAC in accordance with the Agatston method, with the scores classified as ≤10 (no evidence of, or mild CAC) and >10 (moderate and severe CAC). Dietary intake was assessed according to the Food consumption Register (RCA) method. The multivariate Modified Poisson regression model was used to assess cardiovascular risk associated with moderate/severe CAC and the effects of the intake of different nutrients were estimated for the prevalence of moderate/severe CAC, adjusted for calorie intake and CAC risk factors by means of prevalence ratios and 95% confidence intervals. Results: CAC (calcium score >0) was present in 59.3% of the subjects. In the multivariate analysis, factors independently associated with moderate/severe CAC included family history (FH) of early CAD (PR=1.39; 95%CI 1.03-1.88, p=0.029) and physical activity (PA) <150 minutes/week (PR=1.40; 95%CI 1.01-1.93; p=0.045). The intake of some nutrients was also associated with moderate/severe CAC, such as lower carbohydrate intake (p=0.021) and higher lipid intake (p=0.006), after model adjustment for the amount of calories. Once the cardiovascular risk factors and schooling were included in the model, the nutrients associated with the prevalence of moderate/severe CAC were: percentage of carbohydrates (PR=0.98; 95%CI 0.96-0.99; p=0.040), percentage of lipids (PR=1.04; 95%CI 1.01-1.07; p=0.005), and percentage of saturated fatty acids (SFA) (PR=1.08; 95%CI 1.02-1.14; p=0.013). Conclusions: In the sample of community-dwelling asymptomatic adults and older persons, cardiovascular risk factors such as FH of early CAD, and low-intensity PA were independently associated with moderate to severe coronary calcification. Analysis of dietary factors showed that higher intake of total lipids and saturated fats were associated with higher CAC scores, whereas higher intake of carbohydrates over lipids was associated with lower CAC scores. Our results indicate that these risk factors should be considered in the cardiovascular assessment of the patient.

Submitted by CHRISTINE MEN MARTINS null (christinemen@hotmail.com) on 2016-04-20T16:44:53Z No. of bitstreams: 1 Tese Ciência Odontológica - Christine Men Martins.pdf: 3676381 bytes, checksum: c35e89b5716dcdfe110457cff21f6d5c (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-04-25T17:40:01Z (GMT) No. of bitstreams: 1 martins_cm_dr_araca.pdf: 3676381 bytes, checksum: c35e89b5716dcdfe110457cff21f6d5c (MD5) / Made available in DSpace on 2016-04-25T17:40:01Z (GMT). No. of bitstreams: 1 martins_cm_dr_araca.pdf: 3676381 bytes, checksum: c35e89b5716dcdfe110457cff21f6d5c (MD5) Previous issue date: 2016-03-10 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Entre as consequências da forma de ação do MTA e seus produtos encontra-se a participação na indução da mineralização nos tecidos onde é aplicado e a redução da inflamação ali presente. Sendo a hipertensão arterial uma desordem crônica de cunho inflamatório que parece agir negativamente na mobilização do cálcio e nas estruturas ósseas do organismo, pode-se inferir que o desenvolvimento da lesão periapical e o seu tratamento por meio do uso do MTA podem ser alterados pela presença do estado hipertensivo. Dessa forma, o objetivo do presente trabalho foi de estudar a influência da hipertensão arterial no padrão fenotípico da lesão periapical, na diferenciação dos osteoclastos, na resposta inflamatória tecidual e na capacidade de mineralização dos cimentos reparadores à base de MTA. Para isso o trabalho foi dividido em três artigos. O artigo 1 comparou aspectos potenciais da formação da lesão periapical nas condições de hipertensão e normotensão, tendo como hipóteses nulas que a hipertensão não altera a quantidade de osteoclastos diferenciados, o tamanho da lesão periapical e a expressão das citocinas inflamatórias IL1α, IL1β e TNFα da lesão periapical. Esse artigo teve como resposta que, apesar de não haver diferenças estatisticamente significantes entre o tamanho da lesão periapical e a expressão de citocinas inflamatórias, ratos hipertensos apresentaram um elevado número de osteoclastos diferenciados. Já o artigo 2 investigou se a hipertensão afeta a resposta tecidual do MTA branco e cinza implantados subcutaneamente em ratos, bem como a capacidade dessas substâncias para induzir a mineralização, sendo a hipótese nula testada que a hipertensão não altera a resposta tecidual e capacidade de mineralização do MTA. Por meio dos resultados para as análises histológicas com as colorações Hematoxilina e Eosina e Von Kossa e sob luz polarizada, observou-se que a hipertensão exacerba a resposta inflamatória e diminui a capacidade de mineralização, prejudicando, dessa forma, tanto o reparo tecidual quanto a mineralização. Por sua vez, o artigo 3 investigou se hipertensão afeta a resposta de mineralização do MTA branco e cinza implantados subcutaneamente em ratos, através dos biomarcadores osteoblásticos RUNX-2, OPN e OCN em ratos, sendo a hipótese nula que a habilidade de mineralização do MTA não é afetada pela hipertensão. Os resultados apontaram para o prejuízo da capacidade de mineralização para o MTA frente à hipertensão. Então, de forma geral, pode-se concluir que há a associação da hipertensão com periapicopatias de origem endodôntica e seu tratamento, sendo que a hipertensão parece interferir negativamente na quantidade de osteoclastos e na ação do MTA quanto a resposta inflamatória e a capacidade de mineralização. Isso pode colocar a hipertensão como um fator prejudicial para o sucesso do tratamento/retratamento endodôntico. / Among MTA and its products consequences, it is found the participation in mineralization induction in tissue where it is applied and reduction of inflammation maybe present. High blood pressure is a chronic inflammatory disorder that seems acting negatively on calcium mobilization and bone structures of the body. So it can be inferred that periapical lesion development and its treatment using MTA can be altered by the presence of a hypertensive state. Thus, the objective of this research was to study the influence of hypertension in periapical lesion phenotypic, in osteoclast differentiation, in tissue inflammatory response and mineralization ability of MTA repair cements. For this, work was divided into three articles. Article 1 compared potentials aspects of periapical lesion formation in hypertensive and normotensive conditions. Null hypothesis was high blood pressure does not change the number of differentiated osteoclasts, periapical lesion size and expression of IL1α, IL1β and TNFα inflammatory cytokines in apical periodontitis. Among results, although there was no statistically significant difference between periapical lesion size and inflammatory cytokines expression, hypertensive mice showed a large number of differentiated osteoclasts. Article 2 investigated whether hypertension affect tissue response and mineralization ability of white and grey MTA implanted subcutaneously in rats. Null hypotheses were that high blood pressure did not alter tissue response and mineralization capacity against MTA. Through histological analyzes with Hematoxylin and Eosin and Von Kossa stains and under Polarized Light was observed hypertension exacerbates inflammatory response and decrease mineralization capacity, damaging both tissue repair and mineralization. In turn, article 3 investigated whether hypertension affects white and gray MTA mineralization response when they were implanted subcutaneously in rats through osteoblast biomarkers RUNX-2, OPN and OCN. Null hypothesis was that MTA mineralization ability it is not affected by hypertension. The results pointed to the prejudice of MTA mineralization capacity against hypertension. So, in general, it can be concluded that there is an association between periapical problems and its treatment, wherein hypertension impairs number of osteoclasts and MTA action in inflammatory response and mineralization, thus it may be a detrimental factor for successful of endodontic treatment or retreatment. / FAPESP: 2013/09446-1

Introdução: A indicação de endarterectomia carotídea (EAC) profilática em conjunto com revascularização miocárdica (CRM) permanece assunto indefinido. A cirurgia conjunta é amplamente difundida, mas seus resultados vêm sendo questionados. Método: Coorte retrospectiva de 691 pacientes submetidos à CRM, escolhidos aleatoriamente. Avaliação realizada para dados gerais, presença de lesão carotídea, ateromatose aórtica, desfechos neurológicos e óbito. Resultados: Dentre 691 pacientes submetidos à CRM, 16 pacientes apresentaram acidentes vasculares cerebrais (AVC). Dentre esses, 11 pacientes (68.75%) apresentaram AVC localizados em áreas não compatíveis com as lesões carotídeas, sendo três deles com lesões calcificadas na aorta ascendente. Os pacientes com estenose carotídea apresentaram taxa similar de eventos neurológicos totais, AVC e óbito, comparados com pacientes sem estenose carotídea. Um subgrupo de 35 pacientes com estenose carotídea foi submetido à cirurgia coronariana com (14 pacientes) ou sem (21 pacientes) cirurgia de carótida, obtendo-se taxa de eventos neurológicos totais, AVC e óbito estatisticamente semelhantes. Os pacientes com calcificações aórticas apresentaram risco maior de eventos neurológicos (14,58% versus 6.55%, p=0.011), AVC (3,12% versus 2,18%, p=0,47) e óbito (8,33% versus 4,37%, p=0.12). Discussão: Os eventos neurológicos após CRM correlacionam-se com ateromatose aórtica. Os AVC freqüentemente não têm relação linear com a estenose carotídea. Estratégias para minimizar embolia da aorta podem diminuir as taxas de intercorrências neurológicas. / Introduction: The management of patients with simultaneous disease of carotid and coronary arteries is controversial. Studies showed that aortic calcifications might play a role in postoperative stroke at coronary artery bypass graft (CABG), carotid lesions may not be as important as previously considered. Method: A retrospective cohort of a randomly selected group (including elective and emergency operations) of 691 patients submitted to CABG was reviewed for general data, neurological complications and mortality. Results: Among 691 CABGs 16 patients had postoperative stroke. Among these, 11 patients (68.75%) had strokes not matching carotid lesions and anatomic presentation, three of those had detectable aortic calcifications. The patients with critical carotid stenosis had similar rates of neurological events, stroke and death as compared to patients without. The patients with aortic calcifications presented a higher risk of neurological events (14.58% versus 6.55%, p=0.011), stroke (3.12% versus 2.18%, p=0.47) and death (8.33% versus 4.37%, p=0.12). Discussion: The postoperative neurological events after CABG can be related to aortic calcifications. The strokes after coronary bypass may occur independently of the carotid lesions. Strategies to prevent aortic emboli may help preventing many post-operative strokes.