• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 2
  • 1
  • Tagged with
  • 5
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Etude de la calréticuline dans les syndromes myéloprolifératifs : de la détermination de la charge allélique aux mécanismes de dégradation des variants protéiques / Study of calreticulin in myeloproliferative neoplasms : from allelic burden determination to mechanisms of variant proteins degradation

Mansier, Olivier 14 December 2017 (has links)
Des mutations dans le gène de la calréticuline (CALR), codant pour une protéine résidente du réticulum endoplasmique (RE), ont été découvertes récemment dans les syndromes myéloprolifératifs (SMP). Elles sont associées à augmentation de prolifération cellulaire portant spécifiquement sur la lignée mégacaryocytaire. Ceci est le résultat d’une activation constitutive de la signalisation des voies JAK-STAT et MAP Kinases, consécutive à l’interaction des protéines mutantes CALR avec le récepteur à la thrombopoïétine. Plusieurs études ont montré la faible expression de ces protéines mutées dans les cellules, mais aucune n’a déterminé l’impact de leur expression sur l’homéostasie du RE ni les acteurs mis en jeu dans leur élimination. Dans ce travail, nous avons montré que l’expression des protéines CALR mutées ne perturbe pas sensiblement l’équilibre du RE et ne modifie pas la sensibilité des cellules à l’apoptose induite par un stress du RE. Nous avons ensuite démontré dans différents modèles, y compris des cellules engagées dans la différenciation mégacaryocytaire, que les faibles niveaux intracellulaires de variants protéiques CALR n’étaient pas liés à une sécrétion accrue dans le milieu extracellulaire ni à un défaut transcriptionnel. Cette faible expression est en fait la conséquence d’une dégradation mettant en jeu principalement la voie ERAD-protéasome. Dans ce processus, la reconnaissance de motifs glycans n’est pas impliquée, mais EDEM3 semble avoir un rôle majeur puisque son extinction augmente l’expression des formes mutées de CALR. La modulation de cette dégradation pourrait constituer une approche thérapeutique innovante dans les SMP. / Mutations in the calreticulin gene (CALR), encoding for an endoplasmic reticulum (ER) resident protein, have recently been discovered in myeloproliferative neoplasms (MPN). They are associated with an increased cell proliferation, specifically in the megakaryocytic lineage. This is the result of a constitutive activation of the JAK-STAT and MAP kinase pathways, following the interaction of mutant calreticulin proteins with the thrombopoietin receptor. Several studies have demonstrated that these mutated proteins are faintly expressed in cells, but none have determined the impact of their expression on ER homeostasis, nor addressed the actors at play in their degradation. In this work, we showed that the expression of mutated CALR proteins does not significantly disturb ER equilibrium, nor does it change the cellular sensitivity to ER stress-induced apoptosis. We next demonstrated in different models including cells committed towards megakaryocytic differentiation that the poor intracellular levels of variant CALR proteins are neither due to enhanced secretion into the extracellular medium, nor to transcriptional defects. This low-level expression is mainly the result of increased degradation, involving the ERAD-proteasome pathway. In this process, the recognition of glycan motifs is not engaged, but EDEM3 seems to be a key component as its extinction increases the expression levels of variant forms of CALR. Modulating this degradation process could represent a therapeutic option for MPN patients.
2

Implication du chaperome de la protéine F508del-CFTR dans son transport intracellulaire et/ou sa dégradation : rôle des lectines EDEMs et la mannosidase du RE / Involvement of F508del-CFTR protein chaperome in its trafficking defect : role of EDEMs lectins and ER mannosidase I

Sidelarbi, Khadidja 24 November 2017 (has links)
De nombreuses maladies génétiques sont directement liées à la reconnaissance de protéines mal repliées par le contrôle qualité du réticulum endoplasmique (RE), conduisant à leur rétrotranslocation vers le cytosol puis leur dégradation. Dans le cas des glycoprotéines mutées, comme la protéine F508del-CFTR (Cystic Fibrosis Transmembrane conductance Regulator), la démannosylation extensive de leur résidus mannoses constitue une étape clé dans ce processus. L’objectif de ce travail a été d’identifier et de caractériser des molécules capables de rétablir l’expression membranaire de F508del-CFTR en ciblant cette activité enzymatique. Dans un premier temps, nous avons testé des dérivés multivalents basés sur le Deoxymannojirimycin (DMJ), un inhibiteur spécifique de la classe I des α-mannosidases et révélé leur effet correcteur puissant sur F508del-CFTR. Nous avons par la suite mis en évidence leur mécanisme d’action et tenté d’expliquer l’augmentation d’efficacité observée entre les monovalents et les multivalents. Nous nous sommes enfin focalisés sur le rôle des principales mannosidases dans le RE, l’α1,2-mannosidase I du RE (ERManI) et la famille des lectines EDEM (ER degradation-enhancing α-mannosidase-like protein). Nous avons montré par une stratégie de siRNA qu’ERManI, EDEM1 et EDEM2 sont impliquées dans la rétention réticulaire du F508del-CFTR.Notre étude ouvre ainsi de nouvelles perspectives quant à l’identification de nouveaux agents pharmacologiques ciblant ces protéines. / Numerous genetic diseases are directly associated to the recognition of misfolded proteins by the endoplasmic reticulum (ER) quality control, leading to their retention and subsequently their retrotranslocation to the cytosol for degradation. In the case of mutated glycoproteins such as F508del-CFTR (Cystic Fibrosis Transmembrane conductance Regulator), causing CF pathology, mannose trimming is a key step of this process. Our objective was to identify and characterize molecules targeting ER-mannosidases activity, with the goal to restore F508del-CFTR to the plasma membrane.First, we tested multivalent derivatives, based mainly on Deoxymannojirimycin (DMJ), a specific inhibitor of α-mannosidasesI and revealed their better corrective effect on F508del-CFTR and their mechanism of action. Then we explored the mechanism explaining the higher efficiency of the multivalents compared to the monovalent. Finally, we focused on the role of key players of mannose trimming, ER-α1,2-mannosidase I (ERManI) and EDEMs (ER degradation-enhancing α-mannosidase-like protein) proteins on F508del-CFTR trafficking defect. We showed the implication of ERManI, EDEM1 and EDEM2 in F508del-CFTR retention, using a siRNA strategy. In conclusion, our study highlights these proteins as potential pharmacological targets to develop correctors for the F508del-CFTR trafficking defect.
3

[pt] O PAPEL DA MEMÓRIA NA (RE)CONSTRUÇÃO DE IDENTIDADE ORGANIZACIONAL: O CASO DA ESCOLA EDEM / [en] THE ROLE OF MEMORY IN THE (RE)CONSTRUCTION OF ORGANIZATIONAL IDENTITY: THE CASE OF EDEM SCHOOL

ALICE FUCS 01 August 2019 (has links)
[pt] Esta pesquisa, situada no ponto de convergência entre os estudos de identidade organizacional e os estudos sociais de memória, tem por objetivo investigar a recorrente (re)construção identitária de uma escola privada (fundada em 1969 e situada na cidade do Rio de Janeiro), a partir de suas práticas e ações mnemônicas coletivas. Com o objetivo de aprofundar o entendimento das relações entre identidade e memória no âmbito coletivo, este trabalho propôs-se a investigar os dois conceitos a partir da perspectiva social construcionista, fruto de um processo de negociação cotidiana entre os membros da organização, influenciado por diferentes indivíduos, grupos, equipes de gestão e outros coletivos. No que diz respeito aos procedimentos metodológicos, a coleta de dados utilizou fontes provenientes de (a) entrevistas com membros da organização de diferentes funções e níveis hierárquicos; (b) entrevistas com membros externos relacionados à organização de forma indireta; (c) coleta documental; e (d) observação não participante. Em relação à análise dos dados, assumiu-se a flexibilidade da análise temática, para compreender o fenômeno proposto levando em consideração as influências de diferentes atores e contextos sociais. Foram identificados cinco períodos-chave, nos quais a reconstrução identitária se mostrava, de forma mais explícita, necessária à continuidade da essência da organização, e as práticas e ações mnemônicas foram então analisadas ao longo desses períodos. Desta forma, foi possível identificar como a relação dinâmica (processo social contínuo de construção e reconstrução) entre identidade e memória contribuiu para manter a continuidade, ao longo de cinquenta anos, da identidade da escola Edem. / [en] This research, located at the point of convergence between the organizational identity studies and the social memory studies, aims to investigate the recurrent identity (re)construction of a private school (founded in 1969 and located in the city of Rio de Janeiro), through its collective mnemonic practices and actions. In order to deepen the understanding of the relations between identity and memory in the collective sphere, this work has proposed to investigate the two concepts from the social constructionist perspective, the result of a negotiation process among the members of the organization, influenced by different individuals, groups, management teams and other collectives. With regard to methodological procedures, the data collection used the sources from (a) interviews with members of the organization of different functions and hierarchical levels; (b) interviews with external members related to the organization in an indirect way; (c) collection of documents; and (d) nonparticipant observation. In relation to the data analysis, the flexibility of the thematic analysis was assumed in order to understand the proposed phenomenon, taking into account the influences of different actors and social contexts. Five key periods were identified, in which identity reconstruction was more explicitly required for the continuity of the organization s essence, and mnemonic practices and actions were then analyzed over these periods. In this way, it was possible to identify how the dynamic relationship (continuous social process of construction and reconstruction) between identity and memory contributed to maintaining the continuity, over fifty years, of the essence of the identity of Edem school.
4

Uloga inhibitora vaskularnog endotelnog faktora rasta u terapiji dijabetičnog makularnog edema / The role of an inhibitor of vascular endothelial growth factor in the treatment of diabetic macular edema

Jovanović Sandra 25 March 2015 (has links)
<p>Dijabetesna retinopatija je među vodećim uzročnicima stečenog slepila, kako u razvijenim zemljama, tako i zemljama u razvoju. Dijabetesna retinopatija je jedna od<br />najče&scaron;ćih komplikacija Dijabetes Mellitus-a. U sklopu dijabetesne retinopatije jedan od najranijih razloga koji dovodi do pada vidne o&scaron;trine je dijabetični makularni edem (DME). Pad vidne o&scaron;trine kod pacijenata sa dijabetesom naru&scaron;ava njihov kvalitet života i umanjuje radnu sposobnost. Dosada&scaron;nji oblik lečenja laserfotokoaguacijom makule, nije dao zadovoljavajuće rezultate. U novije vreme sve vi&scaron;e je zastupljeno farmakolo&scaron;ko lečenje edema koje podrazumeva intrvitrealnu aplikaciju lekova iz grupe inhibitora vaskularnog endotelnog faktora rasta (VEGF inhibitori), koji dovodi do stabilizacije zidova krvnih sudova.&nbsp;<br />Cilj ove studije je da se ispita efikasnost lečenja DME uz pomoć intravitrealno aplikovanih lekova iz grupe inhibitora vaskularnog endotelnog faktora rasta u odnosu na konvencionalno do sada priznato lečenje laserfotokogulacijom makule.&nbsp;<br />Efikasnost lečenja je procenjivana na dva načina: anatomski, na osnovu smanjenja centralne makularne debljine izražene u &mu;m, merene metodom optičke koherentne tomografije, i funkcionalno, na osnovu pobolj&scaron;anja vidne o&scaron;trine koja je izražavana u log MAR jedinicama. U ovoj prospektivnoj, randomiziranoj kliničkoj studiji sa minimumom praćenja od 6 meseci, u eksperimentalnoj grupi tretiran je 51 pacijent,<br />odnosno 84 oka aplikacijom bevacizumaba (anti VEGF agens) u dozi od 1,25 mg, sa ili bez dodatnog laser tretmana.&nbsp;<br />Uz prosečno 2,46 inekcije postignuta je prosečna redukcija centralne makularne debljine od 139,15 &mu;m.&nbsp; Dobijene vrednosti su nakon svake aplikovane doze su značajno bolje u odnosu na početnu. Edemi sa većom centralnom makularnom debljinom su zahtevali tretman sa većim brojem inekcija. Kod većih edema je postignuta i veća redukcija centralne makularne debljine. U odnosu na vidnu o&scaron;trinu u eksperimentalnoj grupi postignuto je pobolj&scaron;anje od 0,135 log MAR jedinica. Efekat lasera kao samostalne terapije u kontrolnoj grupi (50 pacijenata, 92 oka) nije bio<br />značajan ni u pogledu smanjenja centralne makularne debljine kao ni na osnovu pobolj&scaron;nja vidne o&scaron;trine. Tretman bevacizumabom samostalno ili u kombinaciji sa laserom je efikasniji u tretmanu DME u odnosu na konvencionalni tretman laserfotokoaguacijom koji potvrđeno dovodi do stabilizacije stanja. Značaj ove studije je potvrda efikasnosti i bezbednosti jednog novog oblika lečenja koji samostalno ili u kombinaciji sa laser tretmanom predstavlja novi protokol lečenja dijabetičnog makularnog edema.</p> / <p>Diabetic retinopathy is among the leading causes of acquired blindness in developed countries, as well as in developing countries. Diabetic retinopathy is one of the most frequent Diabetes Mellitus complications. Within diabetic retinopathy, diabetic macular edema (DME) is one of the earliest causes of the loss of visual acuity. Impaired vision causes decline in life quality in diabetic patients and it decreases their<br />working ability. Up to this date, laser photocoagulation treatment has not given<br />satisfactory results. Recently, new promising treatment forms have emerged, including the intravitreal application of vascular endothelium growth factor (VEGF inhibitors), which lead to stabilization of the vessel wall. The aim of this study is to evaluate the efficacy of DME treatment consisting of intravitreal&nbsp; VEGF inhibitor application alone or as a part of combined treatment (intravitreal VEGF inhibitor plus laser photocoagulation) compared with conventional laser treatment alone. The effect of treatment was evaluated according to morphological parameters by measuring central macular thickness (CMT) in &mu;m with optical coherence tomography, and according to functional parameter by visual acuity in log MAR scale. In this prospective randomized clinical trial, with minimum follow up of 6 months, in experimental group 51 patient, or 84 eyes were treated with bevacizumab (VEGF inhibitor) in 1.25 mg dosage, alone or in combination with laser. The mean reduction in was 139.15 &mu;m, which was achieved with 2.46 doses on average. The difference between the final and initial CMT values after each dos age was tatistically significant.<br />Edemas with high central macular thickness required high number of intraviteal<br />aplicatons and the reduction was higher. In our study, mean visual acuity improved significantly in 0.135 log MAR. In control group (50 patient, 92 eyes) treated with laserphotocolagulation alone, the effect on visual acuity and central acular thickness was not statistically significant. The treatment with bevacizumab alone or in combined<br />treatment is more effective in treating DME than conventional macular laser treatment alone, from both - anatomical and functional perspective. The importance of this study is confirmation of the efficacy and safety of a new form of treatment and the introduction of a new protocol for the treatment of diabetic macular edema.</p>
5

Morfološke karakteristike makule kao prognostički faktor poboljšanja vidne oštrine u terapiji pacijenata obolelih od dijabetesnog makularnog edema / Morphological characteristics of the macula as a prognostic factor of visual acuity improvement in the treatment of patients with diabetic macular edema

Džinić Vladislav 26 September 2016 (has links)
<p>Cilj ovog istraživanja je da se ispita uticaj centralne debljine makularne regije (CMT) i prisustva subretinalne tečnosti na vidnu o&scaron;trinu (VA) kod pacijenata obolelih od dijabetesnog makularnog edema, kao i uticaj očuvanosti kontinuiteta spoja spolja&scaron;njeg i unutra&scaron;njeg segmenta fotoreceptora (IS/OS &ndash; kompleks) i spolja&scaron;nje granične membrane (ELM) kao prognostičkih faktora u pobolj&scaron;anju vidne o&scaron;trine nakon primenjene terapije kod pacijenata obolelih od dijabetesnog makularnog edema (DME). Materijal i metode: u ovu retrospektivno prospektivnu kliničku studiju nasumično je uključeno 100 pacijenata koji su podeljeni u dve grupe. Grupu A &ndash; prospektivni deo studije je činilo 50 pacijenata (50 očiju) kod kojih je dijagnostikovan dijabetesni makularni edem i kod kojih je inidikovana primena terapije, laserftotkogaulacije i/ili anti-VEGF terapije (bevacizumab). Grupu B &ndash; retrospektivnu grupu je činilo 50 pacijenata (58 očiju) koji su prethodno lečeni od dijabetesnog makularnog edema primenom laserfotokoagulacije i/ili anti-VEGF terapije (bevacizumab). Nakon kompletnog oftalmolo&scaron;kog pregleda koji se sastojao od određivanja vidne o&scaron;trine (optotipima po Snellenu), biomikroskopije, merenja intraokularnog pritiska i pregleda očnog dna &ndash; fundusa primenom panfundoskopa izvr&scaron;ena je optička koherentna tomografija u svih pacijenata (primenom aparata Stratus&reg; OCT, Carl Zeiss, Meditec i Copercnicus&reg; Optopol). Analiza OCT snimka, je obuhvatila određivanje centralne debljine makule (CMT), prisustva subretinalne tečnosti kao i procenu stanja očuvanosti kontinuiteta spoja spolja&scaron;enjeg i unutra&scaron;njeg segmenta fotoreceptora (IS/OS kompleks) i očuvanost kontinuiteta spolja&scaron;nje granične membrane (ELM). CMT je izračunat primenom softvera OCT aparata i izražen kao srednja vrednost za svih 9 ETDRS polja. Prisutvno subretinalne tečnosti je klasifikovano kao pozitivno ukoliko je identifikovano makar u jednom preseku OCT tomograma .Očuvanost kontinuiteta IS/OS kompleksa i ELM je analizirana u svakom pojedinačnom snimku i podeljena u 3 kategorije. Prva &ndash; ukoliko je očuvano u svim presecima, druga &ndash; ukoliko je očuvano samo u pojedinim presecima i treća &ndash; ukoliko se IS/OS kompleks i ELM nisu mogli identifikovati na nalazu OCT tomograma. Rezultati ukazuju da prisustvo subretinalne tečnosti pre primenjene terapije nema statistički značajnog uticaja na pobolj&scaron;anje vidne o&scaron;trine nakon primenjene terapije u pacijenata grupe A (pA=0,915), a statistička značajnost nije potvrđena ni kod pacijenata koji su prethodno tretirani od DME &ndash; grupa B (pB=0,772). Srednja vrednosti CMT i VA u pacijaneta grupe A iznosila je 474&mu;m&plusmn;140,67&mu;m odnosno 0.25&plusmn;0.20. Nakon primenjene terapije srednja vrednost vidnih o&scaron;trina iznosila je 0.41&plusmn;0.25, dok su vrednosti srednje vrednosti CMT iznosile 343.68&mu;m&plusmn;99.03&mu;m. Potvrđeno je statistički značajno pobolj&scaron;anje vidne o&scaron;trine nakon primenjene terapije (pVA=0,0001) i statistički značajno smanjenje centralne debljine makule (pCMT=0,0001). Korelacija VA sa vrednostima CMT pre primenjene terapije pokazuje statističku značajnost sa negativnom korelacijom (r=-0,391; p=0,005) dok se nakon primenjene terapije ne uočava statistički značajna korelacija (r=-0,047; p=0,746). Analizom vrednosti CMT pre primenjene terapije sa vrednostima VA nakon terapije se uočava statistički značajna negativna korelacija, odnosno veće vrednosti CMT pre primenjene terapije ograničavaju pobolj&scaron;anje vidne o&scaron;trine nakon primenjene terapije (r=-0,393; p=0,005). Evaluacija OCT tomograma, pre primenjene terapije, u pacijenata grupe A utvrđen je u potpunosti očuvan kontinuitet IS/OS kompleksa i ELM u svim presecima u 23 odnosno 27 očiju, u pojedinim presecima u 18 odnosno 16 očiju, i nije mogao biti identifikovan u 9 odnosno 7 očiju. U pacijenata grupe A nakon primenjene terapije uočava se statistički značajno pobolj&scaron;anje vrednosti VA u zavisnosti od očuvanosti kontinuiteta IS/OS kompleksa (F=5,550, p=0,007) i ELM (F=5,428, p=0,008). Univarijantna odnosno multivarjiantna analiza podataka za granične vrednosti vidnih o&scaron;trina od 0,1 i koraka pobolj&scaron;anja od 0,1 ukazuje na statističku značajnost prediktora IS/OS kompleksa (p=0,012 i p=0,032) i ELM (p=0,003 i p=0,018) u pobolj&scaron;anju vrednosti vidnih o&scaron;trina nakon primenjene terapije. Pacijenti sa očuvanim kontinuitetom IS/OS kompelsa u svim presecima imaju 9,5 puta (OR=9,500 ) veću &scaron;ansu za pobolj&scaron;anje VA nakon primenjene terapije u odnosu na pacijente gde kontinuitet IS/OS kompleksa nije uočljiv. Pacijenti sa očuvanim kontinuitetom IS/OS kompleksa u pojedinim presecima imaju 7 puta veću &scaron;ansu (OR=7,000) za pobolj&scaron;anje vidne o&scaron;trine nakon terapije u poređenju sa onima kod kojih IS/OS nije uočljiv. Pacijenti sa očuvanim kontinuitetom ELM u svim presecima imaju 34,5 puta (OR=34,500 ) veću &scaron;ansu za pobolj&scaron;anje vidne o&scaron;trine u odnosu na pacijente gde ELM nije uočljiv. Pacijenti sa očuvanim kontinuitetom ELM u pojedinim presecima imaju 18 puta veću &scaron;ansu (OR=18,000) za pobolj&scaron;anje VA nakon terapije u odnosu na one kod kojih ELM nije uočljiv. Pored statistički značajnog uticaja očuvanosti kontinuiteta IS/OS kompleksa i ELM na pobolj&scaron;anje vrednosti vidnih o&scaron;trina nakon primenjene terapije, uočava se i pozitvna korelacija između vidnih o&scaron;trina pre i nakon terapije (r=0,869; p=0,0001). U pacijenata grupe B srednja vrednost CMT odnosno VA iznosila je 253,72&mu;m&plusmn;75,27&mu;m odnosno 0,68&plusmn;0,29. Postoji statistički značajna razlika u vrednostima VA u odnosu na očuvanost kontinuiteta IS/OS kompleksa (F=107,913, p=0,0001) i ELM (F=25,619, p=0,0001). Poređenjem vrednosti parametara za obe posmatrane grupe uočava se statistički značajna razlika u vrednostima CMT koje su bile manje u grupi B (t=5,355, p=0,0001) i srednjim vrednostima VA ( t=5,137, p=0,0001) koje su bile veće u grupi B. Analizom očuvanosti kontinuiteta IS/OS kompleksa (&chi;2=0,119, p=0,730) i ELM (&chi;2=2,957, p=0,085) ne uočava se statistički značajna razlika. Zaključak: Odnos vidnih o&scaron;trina sa centralnom debljinom makule prikazuje različite vrednosti vidnih o&scaron;trina za iste vrednosti centralne debljine makule. Značajan uticaj na vidnu o&scaron;trinu pacijenata obolelih od DME ima očuvanost integriteta spolja&scaron;nje granične membrane (ELM) i spoja unutra&scaron;njeg i spolja&scaron;njeg segmenta fotoreceptora (IS/OS kompleks) evaluiranih na osnovu OCT snimka &ndash; tomograma. Očuvanost integriteta ELM i IS/OS kompleksa u svim presecima na OCT tomogramu pre primenjene terapije u pacijenta sa DME se mogu smatrati pozitivnim prognostičkim faktorom u pobolj&scaron;anju vidne o&scaron;trine nakon primenjene terapije. U pacijenata kod kojih je kontinuitet ELM i IS/OS kompleksa očuvan u svim pravcima vrednost CMT pre primenjene terapije nema uticaj na pobolj&scaron;anje vidne funkcije nakon terapije. Integritet IS/OS kompleksa i ELM ima pozitivnu korelaciju sa vidnom o&scaron;trinom bez obzira na vrstu primenjene terapije, anti-VEGF odnosno laserfotokoagulacije. Prisustvo subretinalne tečnosti ne utiče na vidnu o&scaron;trinu pacijenata obolelih od DME. Vrednosti VA pre terapije utiču na pobolj&scaron;anje vidne o&scaron;trine nakon terapije.</p> / <p>The aim of this study was to investigate the influence of the central macular thickness (CMT) and the presence of sub retinal fluid on visual acuity (VA) in patients with diabetic macular edema, as well as the impact of preservation and continuity of the photoreceptor inner/outer segment junction (IS / OS - complex ) and external limiting membrane (ELM) as a prognostic factor in improving visual acuity after the applied therapy in patients with diabetic macular edema (DME). Materials and Methods: this retrospective - prospective randomized clinical study included 100 patients who were divided into two groups. Group A - a prospective part of the study, consisted of 50 patients (50 eyes), with the diagnosis of diabetic macular edema in which laser photocoagulation and / or anti-VEGF therapy (bevacizumab) was indicated. Group B - retrospective group, consisted of 50 patients (58 eyes), who were previously treated for diabetic macular edema either with laser photocoagulation and / or anti-VEGF therapy (bevacizumab). After complete ophthalmologic examination, which consisted of the determination of visual acuity (measured with Snellen charts), biomicroscopy, intraocular pressure measurement and inspection of the fundus, optical coherence tomography was performed in all patients (using the Stratus&reg; OCT, Carl Zeiss Meditec and Copercnicus&reg; Optopol). Analysis of OCT image, included the determination of the central macular thickness (CMT), presence of sub retinal fluid, as well as an assessment of the preservation of the continuity of the photoreceptor inner/outer segment junction (IS/OS - complex) and external limiting membrane (ELM). CMT is calculated using software of the OCT apparatus and expressed as the mean value for all 9 ETDRS fields. Presence of sub retinal fluid is classified as positive if it is identified in at least one cross-section of OCT tomogram. Preserved continuity of IS / OS complex and ELM is analyzed in each individual OCT cross-section image and divided into 3 categories. First - if it is preserved in all cross sections images, the second - if it is preserved only in certain sections and the third - if the IS / OS complex and ELM were not able to identify in OCT tomograms. The results indicate that the presence of sub retinal fluid before the applied therapy has no statistically significant effect on improving visual acuity after the applied therapy in patients of group A (pA = 0.915), and statistical significance was not also confirmed in any of the patients who were previously treated by DME - Group B (pB = 0.772). Mean CMT and VA values of patients in group A was 474&mu;m &plusmn; 140,67&mu;m and 0.25 &plusmn; 0.20. After receiving therapy mean visual acuity was 0.41 &plusmn; 0.25, while the value of the mean CMT was 343.68&mu;m&plusmn; 99.03&mu;m. Significant improvement in visual acuity was achieved after the treatment in group A (pVA = 0.0001) together with statistically significant reduction in central macular thickness (pCMT = 0.0001). Correlation of VA with the values of CMT before applied therapy shows statistically significant negative correlation (r = -0.391; p = 0.005), while after the applied therapy statistical significance was not observed (r = -0.047; p = 0.746). Analyzing the values of CMT before the applied therapy with the values of VA after the treatment statistically significant negative correlation was observed, higher values of CMT before the applied therapy restrict visual acuity improvement after the applied therapy (r = -0.393; p = 0.005). Analyzing OCT tomograms in the patients in group A, before the applied therapy, fully preserved continuity of IS/OS complex and ELM in all the sections was found in 23 and 27 of the eyes, in certain sections in 18 and 16 of the eyes, and could not be identified in 9 and 7 eyes. Statistically significant improvement in VA, after the applied therapy, in patients in group A is observed, depending on the preservation of continuity of IS/OS complex (F = 5.550, p = 0.007) and ELM (F = 5.428, p = 0.008). Univariate and multivariate analysis with cut off VA value of 0.1 and step improvements of 0.1 points to statistically significant predictor of IS/OS complex (p = 0.012 and p = 0.032) and ELM (p = 0.003 and p = 0.018) in improving the VA after the applied therapy. Patients with preserved continuity of IS/OS complex in all sections are 9.5 times (OR = 9.500) more likely to improve the VA after receiving therapy compared to patients where continuity of IS/OS complex is not noticeable. Patients with preserved continuity of IS/OS complex in the some sections are 7 times more likely (OR = 7.000) for the improvement of visual acuity after treatment compared to those in which the IS/OS is not detectable. Patients with preserved continuity of ELM in all sections are 34.5 times (OR = 34,500) a greater chance to improve visual acuity compared to patients where ELM is not apparent. Patients with preserved continuity of ELM in the some sections are 18 times more likely (OR = 18,000) to improve the VA after treatment compared to those in which the ELM is not apparent. In addition to statistically significant impact of preservation of continuity of IS/OS complex and ELM for VA improvement after the treatment, statistically significant positive correlation between visual acuity before and after treatment (r = 0.869; p = 0.0001) was observed. In Group B patients, the mean CMT and VA value was 253,72&mu;m&plusmn;75,268&mu;m and 0.68 &plusmn; 0.29. There is a statistically significant difference in the VA values compared to the preservation of continuity of IS/OS complex (F = 107.913, p = 0.0001) and ELM (F = 25.619, p = 0.0001). Comparing the values of parameters for both groups, statistically significant difference in CMT values and mean VA was observed. CMT values were lower (t = 5.355, p = 0.0001) while VA values were higher (t = 5.137, p = 0.0001), in group B. The analysis of preservation of continuity of IS/OS complex (&chi;2 = 0.119, p = 0.730) and ELM (&chi;2 = 2.957, p = 0.085) did not show a statistically significant difference. Conclusion: The relationship of visual acuity with central macular thickness shows the different levels of visual acuity for the same value of the central macular thickness. A significant impact on VA in patients with DME has maintained integrity of the external limiting membrane (ELM) and the photoreceptors inner/outer segments junction (IS/OS complex) evaluated on the basis of OCT - tomograms. Preservation of the integrity of the ELM and IS/OS complex in all sections of the OCT tomogram before applied therapy in patients with DME can be considered a positive prognostic factor in improving visual acuity after receiving therapy. In patients with preserved continuity of ELM and IS/OS complex in all sections before applied therapy the CMT value has no effect on the improvement of visual function after treatment. Regardless of the type of applied therapy, anti-VEGF and/or laser photocoagulation preserved integrity of IS/OS complex and ELM has a positive correlation with visual acuity. The presence of sub retinal fluid does not affect the visual acuity in patients with DME. The values of VA before treatment influence the improvement of visual acuity after treatment.</p>

Page generated in 0.0193 seconds