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  • 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.
31

Biological studies on the lepidopteran egg parasitoid Trichogrammatoidea lutea Girault (Hymenoptera : Trichogrammatoidae) at various temperatures

Mawela, Khethani Vincent 16 May 2011 (has links)
The African bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is a polyphagous pest that attacks many crops in sub-Saharan Africa. The pest is currently managed through chemical control, and by planting Bt-transgenic cotton. Trichogrammatoidea lutea Girault (Hymenoptera: Trichogrammatidae) is an indigenous egg parasitoid of H. armigera in southern Africa. The study was undertaken to determine the potential of T. lutea as a biological control agent for augmentative releases as an alternative to chemical control, and to pave the way for the development of a mass-rearing method. The biology of T. lutea was examined in the laboratory on H. armigera, Chilo partellus (Swinhoe), and Cadra (formerly Ephestia) cautella (Walker) (Lepidoptera: Pyralidae). The objectives of the study were to determine (i) the exposure time of UV-irradiation required for killing the embryos of the hosts and the effect of UV-irradiated eggs on life history parameters of T. lutea, (ii) which host(s) and temperature(s) (18, 21, 24, 27, 30 and 35 °C) are suitable for mass-rearing of T. lutea, and (iii) the longevity and age-related reproductive biology of T. lutea on H. armigera. Findings of this study showed that 13 minutes of UV-irradiation were sufficient to kill embryos of all three host species. Life history parameters were not influenced by UV-irradiation but by host species. Parasitism, number of progeny per parasitized egg, proportion of females, and developmental time of T. lutea aried on different host species at temperatures ranging from 18 to 30 °C. Trichogrammatoidea lutea did not develop at 35 °C. Overall parasitism by T. lutea was higher on H. armigera and Cadra cautella compared to Chilo partellus. The number of progeny per parasitized egg was highest on H. armigera compared to Cadra cautella and Chilo partellus. The proportion of females was highest on Chilo partellus, intermediate on Cadra cautella, and lowest on H. armigera. For all species and temperatures tested, parasitism and number of progeny per parasitized egg by T. lutea was highest on H. armigera at 27 °C. The lower threshold for development of T. lutea on all hosts was approximately 12 °C. Female T. lutea parasitized eggs of H. armigera soon after eclosion, with the highest parasitism achieved on the day of eclosion. Though T. lutea parasitized eggs for up to 14 days, it may not be economically viable to keep them in cultures for more than three days since progeny became male biased three days after eclosion. The average longevity of female and male T. lutea was 9 and 6 days, respectively. The life table parameters of T. lutea, the net replacement rate (Ro), mean generation time (T), and instantaneous rate of population increase (rm) were 25.5, 9.79, and 0.33, respectively. The timing of inundative releases of T. lutea must be synchronised with the time that eggs of H. armigera are abundant in the field. The results of this study indicate that T. lutea is a good candidate for further testing for augmentative biological control of H. armigera in the field. If successful, T. lutea may provide opportunities for expanding tactics in the management of H. armigera in southern Africa. Copyright / Dissertation (MSc)--University of Pretoria, 2011. / Zoology and Entomology / unrestricted
32

Metabolite Profiling of Red Sea Corals

Ortega, Alejandra 12 1900 (has links)
Looking at the metabolite profile of an organism provides insights into the metabolomic state of a cell and hence also into pathways employed. Little is known about the metabolites produced by corals and their algal symbionts. In particular, corals from the central Red Sea are understudied, but interesting study objects, as they live in one of the warmest and most saline environments and can provide clues as to the adjustment of corals to environmental change. In this study, we applied gas chromatography – mass spectrometry (GC–MS) metabolite profiling to analyze the metabolic profile of four coral species and their associated symbionts: Fungia granulosa, Acropora hemprichii, Porites lutea, and Pocillopora verrucosa. We identified and quantified 102 compounds among primary and secondary metabolites across all samples. F. granulosa and its symbiont showed a total of 59 metabolites which were similar to the 51 displayed by P. verrucosa. P. lutea and A. hemprichii both harbored 40 compounds in conjunction with their respective isolated algae. Comparing across species, 28 metabolites were exclusively present in algae, while 38 were exclusive to corals. A principal component and cluster analyses revealed that metabolite profiles clustered between corals and algae, but each species harbored a distinct catalog of metabolites. The major classes of compounds were carbohydrates and amino acids. Taken together, this study provides a first description of metabolites of Red Sea corals and their associated symbionts. As expected, the metabolites of coral hosts differ from their algal symbionts, but each host and algal species harbor a unique set of metabolites. This corroborates that host-symbiont species pairs display a fine-tuned complementary metabolism that provide insights into the specific nature of the symbiosis. Our analysis also revealed aquatic pollutants, which suggests that metabolite profiling might be used for monitoring pollution levels and assessing environmental impact.
33

Značaj optičke koherentne tomografije makule kod glaukoma otvorenog ugla / Optical coherence tomography of macula in primary open angle glaucoma

Babović Siniša 13 May 2016 (has links)
<p>Cilj ovog istraživanja je bio da se utvrdi da li postoji razlika u debljini makule kod pacijenata sa glaukomom otvorenog ugla (POAG) u odnosu na zdravu populaciju i u zavisnosti od stepena progresije bolesti, kao i da se utvrdi da li postoji povezanost između promene debljine makule i stepena o&scaron;tećenja vidnog polja i debljine peripapilarnog sloja nervnih vlakana u zavisnosti od stepena progresije bolesti. Materijal i metode: U ovu kliničku prospektivnu studiju je uključeno 186 pacijenata. Na osnovu kliničkog nalaza formirane su tri grupe. Prva grupa (kontrolna &ndash; grupa zdravih): 68 pacijenata bez očnih oboljenja, sa najboljom korigovanom vidnom o&scaron;trinom &ge; 0.9, intraokularnim pritiskom (IOP) &le; 21 mmHg, normalnim odnosom ekskavacije i povr&scaron;ine glave vidnog živca i normalnim nalazom vidnog polja. Druga grupa (rani glaukom): 78 pacijenata sa klinički dijagnostikovanim primarnim glaukomom otvorenog ugla (sa karakterističnim o&scaron;tećenjem glave vidnog živca i sloja nervnih vlakana retine i kod kojih je srednja vrednost devijacije standardne automatske perimetrije MD &gt; -6 dB, prema Hodap klasifikaciji), bez drugih očnih ili sistemskih oboljenja, koja bi imala uticaj na nastanak glaukoma i sa najboljom korigovanom vidnom o&scaron;trinom &ge; 0.5. Treća grupa (glaukom srednjeg stepena): 40 pacijenata sa klinički dijagnostikovanim primarnim glaukomom otvorenog ugla (sa karakterističnim o&scaron;tećenjem glave vidnog živca i sloja nervnih vlakana retine i kod kojih je srednja vrednost devijacije standardne automatske perimetrije -6 dB &gt; MD &gt; -12 dB, prema Hodap klasifikaciji), bez drugih očnih ili sistemskih oboljenja, koja bi imala uticaj na nastanak glaukoma i sa najboljom korigovanom vidnom o&scaron;trinom &ge; 0.5. Svim pacijentima je bio urađen kompletan oftalmolo&scaron;ki pregled, kompjuterizovano vidno polje (Humphrey Field Analyzer, Carl Zeiss Meditec, Jena, Germany, SITA Standard, test C 24-2) i optička koherentna tomografija sloja nervnih vlakana peripapilarno i u predelu makule (SOCT Copernicus HR, Optopol Tech. SA, Zawiercie, Poland). Rezultati: Perifovea i parafovea, pokazuju statistički značajno smanjenje debljine i zapremine sloja nervnih vlakana u odnosu na stepen progresije glaukoma otvorenog ugla, pri čemu je ono nagla&scaron;enije u perifovei (p&lt;0,05). U svim segmentima makule (TPeriF, IPeriF, SPeriF, NPeriF, TParaF, SParaF, IParaF i NParaF) dolazi do smanjenja debljine i zapremine sloja nervnih vlakana sa progresijom bolesti (p&lt;0,05). Segmenti makule TPeriF, IPeriF, a potom i SPeriF, prema navedenom redosledu, predstavljaju segmente sa najvećim potencijalom za predikciju ranih glaukomskih o&scaron;tećenja s obzirom na uočeno najveće smanjenje debljine i zapremine nervnih vlakana (p&lt;0,05). Segmenti makule SParaF i NParaF predstavljaju segmente sa najvećim potencijalom za predikciju napredovanja glaukomskih o&scaron;tećenja srednjeg stepena s obzirom na uočeno najveće smanjenje debljine i zapremine nervnih vlakana (p&lt;0,05). Debljina RNFL glave vidnog živca se statistički značajno smanjuje sa progresijom bolesti u svim posmatranim segmentima (p&lt;0,05). Međusobni odnos između grupe zdravih i grupe pacijenata sa ranim glaukomom ukazuje da je statistički značajno smanjenje debljine RNFL prisutno u svim segmentima osim u segmentima P3 i P4 (p&gt;0,05). Merenja debljine RNFL u segmentu P6 imaju najbolji potencijal za predikciju ranog glaukoma s obzirom na najizraženije smanjenje debljine nervnih vlakana upravo u ovom segmentu (p&lt;0,05). Merenja debljine RNFL u segmentu P1 ima najbolji potencijal za predikciju dalje progresije bolesti. Debljina sloja nervnih vlakana makule srazmerna je smanjenju debljine RNFL na glavi vidnog živca, pri čemu je ona uočljivija na nivou segmenata koji su okarakterisani kao dobri prediktori za nastanak, odnosno progresiju bolesti (P6 sa IPeriF i TPeriF, odnosno P1 sa SPeriF), &scaron;to dodatno nagla&scaron;ava njihovu važnost u dijagnostici glaukoma otvorenog ugla. Debljina makule kod pacijenata sa glaukomom otvorenog ugla je opisana umerenom do dobrom povezano&scaron;ću sa stepenom o&scaron;tećenja vidnog polja, pri čemu je ona najjača kod TPeriF, IPeriF i SPeriF segmenata i srazmerna je stepenu o&scaron;tećenja vidnog polja. Koeficijenti korelacije između vrednosti srednje devijacije vidnog polja i debljine RNFL, odnosno&nbsp; sloja nervnih vlakana makule, pokazuju snažniju povezanost u odnosu na parametre dobijenog smanjenja debljine nervnih vlakana u makuli, &scaron;to otvara mogućnost za dalja istraživanja. Segmenti glave vidnog živca i makule, koji su pokazali najbolju diskriminaciju u smislu predikcije nastanka POAGa, kao i oni koji sugeri&scaron;u na njegovu progresiju, sme&scaron;teni su na lokacijama koje su međusobno povezane opisanim prirodnim tokom nervnih vlakana.&nbsp; Zaključak: Optička koherentna tomografija makule je važna pomoćna metoda u dijagnostici glaukoma kojom je moguće izdvojiti pacijente sa ranim glaukomom u odnosu na zdravu populaciju, odnosno utvrditi progresiju glaukoma otvorenog ugla.</p> / <p>All patients underwent complete ophthalmologic examination, SAP (Humphrey Field Analyzer, Carl Zeiss Meditec, Jena, Germany, SITA Standard, test C 24-2) and optical coherent tomography scans of RNFL and macula (SOCT Copernicus HR, Optopol Tech. SA, Zawiercie, Poland). Results: Perifoveal and parafoveal nerve fiber layer have shown significant reduction of thickness and volume compared to stage of POAG progression, where perifovea showed higher significance (p&lt;0,05). All macular segments (TPeriF, IPeriF, SPeriF, NPeriF, TParaF, SParaF, IParaF i NParaF) showed reduction in thickness and volume compared to disease progression (p&lt;0,05). Macular segments TPeriF, IPeriF, as well as SPeriF, represent segments with highest potential to predict early glaucomatous damage according to the most significant reduction of nerve fiber layer thickness and volume (p&lt;0,05). Macular segments SParaF and NParaF represent segments with highest potential to predict progression of POAG according to the most significant reduction of nerve fiber layer thickness and volume (p&lt;0,05). Optic nerve head (ONH) RNFL thickness showed reduction compared to POAG progression in all segments (p&lt;0,05). All ONH segments except P3 and P4 showed significant reduction of RNFL comparing control group to early glaucoma group patients (p&gt;0,05). ONH segment P6 was found to be the highly specific for early glaucoma prediction according to the most significant reduction of RNFL thickness (p&lt;0,05), while segment P1 was found to have highest potential for POAG progression. Macular nerve fiber layer thickness reduction follows ONH RNFL thickness reduction and there is mutual relation between both macular and ONH segments (P6 to IPeriF and TPeriF, P1 to SPeriF) with highest specificity for early defects and POAG progression. It was shown that macular thickness changes have moderate to good correlation with visual filed changes and it was highest in TPeriF, IPeriF and SPeriF segments. This correlation was found to be higher in macula then in ONH RNFL thickness changes, compared to visual field changes. Both macular and ONH RNFL segments, which were found to have highest specificity to POAG prediction and progression, are located in areas which mutually connect following natural course of nerve fiber layer between them. Conclusion: Optical coherence tomography of macula represents important ancillary method in POAG diagnosis and follow up, allowing to differentiate between early glaucoma patients and healthy individuals, as well as to determine progression of glaucomatous disease.</p>
34

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>
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Untersuchungen zur Expression von Interleukin-10 nach Transfektion humaner retinaler Pigmentepithelzellen und dessen Einfluss auf die Proliferation von T-Lymphozyten in vitro

Poschinger, Katharina 27 March 2003 (has links)
Bei der Altersabhängigen Makuladegeneration (AMD) handelt es sich um eine Erkrankung des Auges, die die Macula lutea, die Stelle des schärfsten Sehens betrifft. Sie ist verbunden mit der Degeneration von RPE-Zellen, die zur Dystrophie von Photorezeptoren und damit zum Verlust des zentralen Sehvermögens führt. Eine ähnliche Pathophysiologie ist bei der sogenannten Retinalen Pigmentepitheldystrophie (RPED) des Hundes zu beobachten. Die Transplantation von gesunden RPE-Zellen in das betroffene Gebiet stellt eine vielversprechende Therapiemöglichkeit dar. Die Transplantatabstoßung als Kom-plikation schränkt die klinische Anwendung ein. Eine beim Patienten nach Transplantation lebenslang durchgeführte systemische Immunsuppression ist mit erheblichen Nebenwirkungen verbunden. Deshalb bietet die Gentherapie unter Einbezug immunsuppressiver Zytokine wie beispielsweise des Interleukin-10 (IL-10) eine Lösung. In der vorliegenden Arbeit wurde ein selbst konstruierter IL-10-Expressionsvektor (Plasmid pCIneoIL-10) mittels Gentransfer in humane RPE-Zellen in vitro eingebracht. Untersucht wurde die Wirkung des sezernierten IL-10 auf die Proliferation von allogenen T-Lymphozyten mit und ohne allogene Makrophagen als professionelle antigenpräsentierende Zellen (APC). Neben humanen Spender RPE-Zellen (Spender-hRPE-Zellen) wurde eine immortalisierte Permanent-Zelllinie (hTERT-RPE1-Zellen) eingesetzt, deren Hauptvorteil in einer gleichbleibend hohen Wachstumsrate lag. Als transientes Transfektions-system für den Transfer von IL-10-DNA in hRPE-Zellen wurden kationische Lipide gewählt. Drei verschiedene Lipidformulierungen wurden miteinander verglichen und das optimale Transfektionsreagenz:DNA-Verhältnis, mit dem die höchste Transfektionseffizienz erreicht werden konnte, evaluiert. Eine Transfektionseffizienz von 23,3 ± 9,0 % (hTERT-RPE1-Zellen) beziehungsweise 10,3 ± 4,5 % (Spender-hRPE-Zellen) konnte erreicht werden. Die Transfektion hatte weder einen negativen Einfluss auf die Vitalität der hRPE-Zellen, noch wurde der natürliche Zelltod, die Apoptose, erhöht. Die IL-10-mRNA-Expression wurde mittels RT-PCR nachgewiesen. Lediglich bei den transfizierten hRPE-Zellen konnte IL-10-mRNA gefunden werden. Mittels ELISA konnte das IL-10-Protein gemessen werden. Die Sekretion des IL-10 in den Kulturüberstand von transfizierten hRPE-Zellen wurde dafür über einen Zeitraum von 7 Tagen untersucht. Es konnte festgestellt werden, dass die maximale IL-10-Proteinkonzentration bei beiden Zelllinien am Tag 3 mit Werten von 10,3 ± 0,8 ng/ml (hTERT-RPE1-Zellen) und 3,1 ng/ml (Spender-hRPE-Zellen) lag. Es bestand überdies eine positive Korrelation zwischen Transfektionseffizienz und synthetisiertem IL-10. Es wurde außerdem gezeigt, dass durch Stimulation mit dem immunmodulatorischen Zytokin Interferon-gamma (IFN-g) hRPE-Zellen MHC Klasse II-Moleküle vermehrt exprimierten. Damit sind sie ebenso wie die Makrophagen zur Antigenpräsentation fähig. Die Wirkung des von den transfizierten hRPE-Zellen sezernierten IL-10 auf die Proliferation von T-Lymphozyten wurde zwischen Tag 2 und Tag 6 (hTERT-RPE1-Zellen) beziehungsweise zwischen Tag 2 und Tag 4 (Spender-hRPE-Zellen) photometrisch untersucht. Die Proliferation allogener T-Lymphozyten mit beziehungsweise ohne Makrophagen konnte durch das sezernierte IL-10 supprimiert werden. Bei den hTERT-RPE1-Zellen lag ohne die Anwesenheit von professionellen APC am Tag 6 eine signifikante Reduktion der T-Lymphozytenproliferation vor, während bei Kokultivierung mit Makrophagen Signifikanzen am Tag 5 und Tag 6 erkennbar waren. Die immunsuppressive Wirkung von IL-10 konnte mittels Anti-IL-10-Antikörper neutralisiert werden. Damit wurde bewiesen, dass die proliferations-supprimierende Wirkung auf IL-10 zurückzuführen war. Diese Ergebnisse könnten demnach neue Möglichkeiten zur Verhinderung einer Abstoßungsreaktion nach RPE-Zelltransplantation bei Patienten mit AMD eröffnen / Age-related macular degeneration (AMD) is a disease of eyes affecting the macula lutea, the area of the retina with the highest density of retinal pigment epithelial cells (RPE cells). The disease is characterized by degeneration of RPE cells resulting in dystrophy of photoreceptors and finally loss of central vision. Transplantation of healthy RPE cells is a promising possibility for therapy but rejection of the allotransplant limits clinical application. One way to avoid this complications is a systemic immunosuppression of the recipient but this is combined with many side effects. In this thesis a self-constructed IL-10 expression vector (plasmid pCIneoIL-10) has been transferred into human RPE cells in vitro by gene transfer. In addition to human donor RPE cells a permanent RPE cell line (hTERT-RPE1 cells) was employed. Kationic lipids were used as transient transfection system for transfer of pCIneoIL-10 into hRPE cells. Three different lipid formulations and various ratios of transfection reagent:DNA were evaluated for highest transfection efficacy. With the optimized protocols a transfection efficacy of 23,3 ± 9,0 % (hTERT-RPE1 cells) and 10,3 ± 4,5 % (donor hRPE cells) was achieved. A negative influence on the viability of the hRPE cells after transfection was not observed. The IL-10 mRNA expression was analysed by reverse transcription-polymerase chain reaction (RT-PCR). Only in transfected hRPE cells the IL-10 mRNA-amplicon with 383 bp in size was found. Secretion of IL-10 protein in the cell culture supernatants of transfected hRPE cells was investigated using an enzyme-linked immunosorbent assay (ELISA) daily for 7 days. The IL-10 protein concentrations peaked at day 3 with 10,3 ± 0,8 ng/ml (hTERT-RPE1 cells) and 3,1 ng/ml (donor hRPE cells). The amount of secreted IL-10 positively correlated with transfection efficacy. After stimulation with the immunmodulatory cytokine interferon-gamma (IFN-g) the expression of MHC class II molecules on hRPE cells is increasing. Therefore they are able to present antigens similar to macrophages. Hence, the effects of recombinantly expressed IL-10 on the proliferation of allogeneic T lymphocytes were investigated both with and without allogeneic macrophages as professional antigen presenting cells (APC). Proliferation of T lymphocytes has been investigated colorimetrically between day 2 and day 6 (hTERT-RPE1 cells) and day 2 and day 4 (donor hRPE cells) respectively. The proliferation of allogeneic T lymphocytes with and without macrophages could be suppressed by the secreted IL-10. Signifikant reduction of proliferation was observed at day 6 in absence of professional APC (14,1 ± 1,1 % to 100% of untransfected control) and between day 5 (44,1 ± 4,9 %) and day 6 (37,4 ± 6,3%) in the presence of macrophages. It was possible to neutralize the immunosuppressive effect of IL-10 with anti-IL-10 antibodies. Proving that the suppressive effect of T lymphocyte proliferation was caused by IL-10. Thus, the specific IL-10 gene transfer into hRPE cells prior to transplantation may prevent rejection process and could prove a reliable method to help prevent loss of central vision due to AMD.
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BEVACIZUMABE INTRA-VÍTREO: ANÁLISE DA TOXICIDADE RETINIANA APÓS 3 MESES EM OLHOS DE COELHOS NÃO ALBINOS / Bevacizumab INTRA-VITREOUS: ANALYSIS OF RETINAL TOXICITY AFTER 3 MONTHS IN EYES OF RABBITS NOT ALBINO

ARRAES, João Carlos Diniz 19 June 2009 (has links)
Made available in DSpace on 2014-07-29T15:25:22Z (GMT). No. of bitstreams: 1 tese joao arraes ciencias saude.pdf: 3252483 bytes, checksum: be116024cf6d2b2b6cef094fc736420d (MD5) Previous issue date: 2009-06-19 / Antiangiogenesis therapy has become a first-line treatment for neovascular age-related macular degeneration (AMD). Bevacizumab has proven to be efficient and cost effective, however its use in AMD is still off-label. PURPOSES: Evaluating the histological toxicity of bevacizumab on the neurosensorial retina (NSR) and the retinal pigmented epithelium (RPE) in pigmented rabbit eyes; evaluating if a fast increase in vitreous volume after a 0.1 ml balanced saline solution (BSS) intravitreal injection (IVI) in a rabbit eye will lead to histological damages in the NSR and RPE; and evaluating postoperative clinical complications after an IVI in rabbits eyes. METHODS: Eighteen pigmented rabbits (36 eyes) were divided into 4 groups a Control Group (3 rabbits - 6 eyes), which did not receive any IVI; the rabbits were sacrificed at the beginning of the study. Thirty eyes of the fifteen remaining rabbits were distributed to three groups: a sham group (S), that received a 0.1 ml balanced saline solution (BSS) IVI (ten eyes); group 1, that received a 1.25 mg (0.1 ml) bevacizumab IVI (ten eyes); and group 2, that received a 2.5 mg (0.1 ml) bevacizumab IVI (ten eyes). Postoperative clinical evaluation included inspection of the anterior segment and indirect binocular ophthalmoscopy. The rabbits were sacrificed 90 days after the procedure and both eyes of all the rabbits were enucleated. Histological examination of the NSR and RPE were performed and their morphological features and layer thickness were analyzed. RESULTS: No significant postoperative clinical complications were observed either in the neurossensorial retina or in the RPE. Histological morphology and thickness of the NSR and RPE layers did not differ significantly between BBS-injected eyes and bevacizumab-injected eyes. CONCLUSIONS: A rapid increase in vitreous volume, after 0.1 ml BSS IVI did not lead to any histological damage in the NSR and RPE in rabbit eyes. After a 90-day follow-up period, a single Bevacizumab 1.25 and 2.5 mg intravitreal injection did not lead any toxic damage in the NSR and RPE. No important postoperative complications in pigmented rabbit eyes were observed and it appears to be a safe procedure for the treatment of retinal neovascular diseases / A terapia anti-angiogênica tornou-se o tratamento de primeira linha para a forma neovascular da degeneração macular relacionada à idade. O Bevacizumabe é uma droga com boa eficácia e custo-efetividade, porém seu uso nesta doença ainda é considerado off-label. OBJETIVOS: Avaliar a toxicidade sobre a retina neurossensorial (RNS) e epitélio pigmentado da retina (EPR) da injeção intra-vítrea (IV) de bevacizumabe em olhos de coelhos não albinos; avaliar se o aumento súbito do volume vítreo após a injeção IV de 0,1ml de solução salina balanceada (SSB) no olho do coelho leva a danos histológicos na RNS e EPR; e avaliar as complicações clínicas pós-operatórias após a injeção IV em olhos de coelhos. MÉTODOS: 18 coelhos não albinos (36 olhos) foram distribuídos em 4 grupos. O grupo controle (3 coelhos 6 olhos), o qual não recebeu injeção IV, foi sacrificado no início do estudo. Os trinta olhos dos 15 coelhos restantes foram distribuídos em 3 grupos (1:1:1): Grupo Placebo (injeção IV de 0,1ml de SSB); Grupo 1 (injeção IV de 1,25mg/0,1ml de bevacizumabe); e Grupo 2 (injeção IV de 2,5mg/0,1ml de bevacizumabe). Os coelhos foram acompanhados por um período de 90 dias após o procedimento, quando então foram submetidos a eutanásia. Todos os coelhos tiveram seus olhos enucleados e avaliados histologicamente. Foram realizadas avaliação clínica pós-operatória (inspeção do segmento anterior e oftalmoscopia binocular indireta) e avaliação histológica da morfologia e da espessura das camadas da RNS e EPR. RESULTADOS: Não foram observadas complicações clínicas pós-operatórias significantes. A morfologia histológica e espessura das camadas da RNS e EPR não apresentou diferença significante entre os grupos controle e placebo, grupo placebo e grupo 1 e grupo placebo e grupo 2. CONCLUSÕES: A injeção IV de 1,25mg/0,1ml e 2,5mg/0,1ml bevacizumabe não leva a alterações histológicas tóxicas na RNS e EPR, nem a complicações clínicas pós-operatórias importantes em olhos de coelhos não albinos. A injeção IV de 0,1ml de SSB não leva a danos histológicos ao RNS e ao EPR em olhos de coelhos não albinos
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Koncentrisk hämning och stimulans av bakterietillväxt i agarkulturer

Larsson, Kristoffer January 2005 (has links)
The aim of this study is to elucidate factors that effect growth of Sarcina lutea and Bacillus subtilis, exposed to the growth inhibitor SDS (Sodiumdodecylsulfat). Agar diffusion experiments revealed repeated, concentric zones of inhibition and stimulation upon exposure to Sodiumdodecylsulphate or to Amoxicillin. Temperature, nutrient concentration and inhibitor concentration were controlled. Formation of successively repeated zones of inhibition, stimulation, inhibition and stimulation is discussed: •The extension of the primary inhibition zone is due to the concentration of applied Sodium dodecyl sulphate.•Immediately outside the primary inhibition zone the bacteria have access to diffusing nutrients that have not been consumed in the primary inhabitation zone.•In zones of dense bacterial growth the bacteria may produce inhibiting substances, affecting growth of bacteria in adjacent zones.•In zones of dense bacterial growth the nutrients will soon become depleted, thus affecting bacteria in adjacent zones.
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Secagem em camada de espuma da polpa de cajá. / Foam mat drying of the cajá pulp.

FERNANDES, Tâmila Kassimura da Silva. 13 June 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-06-13T13:18:30Z No. of bitstreams: 1 TÂMILA KASSIMURA DA SILVA FERNANDES - DISSERTAÇÃO PPGEA 2010..pdf: 33235363 bytes, checksum: 4b55d8a3a81c743809e6243d3ff527ae (MD5) / Made available in DSpace on 2018-06-13T13:18:30Z (GMT). No. of bitstreams: 1 TÂMILA KASSIMURA DA SILVA FERNANDES - DISSERTAÇÃO PPGEA 2010..pdf: 33235363 bytes, checksum: 4b55d8a3a81c743809e6243d3ff527ae (MD5) Previous issue date: 2010-12 / Este trabalho foi desenvolvido com o objetivo de desidratar a polpa de cajá através do processo de secagem em camada de espuma e analisar, através do planejamento experimental fatorial, o produto em pó obtido. Três formulações foram elaboradas com a polpa de cajá integral e três diferentes concentrações do emulsificante Emustab® (1, 2 e 3%), e uma concentração fixa do aditivo Super Liga Neutra (2%), as quais foram agitadas em batedeira durante 15 minutos, formando espuma. A polpa de cajá e as formulações foram caracterizadas quanto aos parâmetros químicos, físicos e físico-químicos. As Formulações (espumas) 1, 2 e 3 foram desidratadas em estufa com circulação forçada de ar, nas temperaturas de 60, 70 e 80 °C e com espessura da camada de espuma de 0,5; 1,0 e 1,5 cm. Os modelos de Page, Henderson & Pabis e Cavalcanti Mata foram ajustados aos dados experimentais das curvas de secagem. Os pós obtidos ao fim do processo de secagem foram analisados quanto aos parâmetros teor de água, °Brix, pH, acidez, açúcares (redutores, totais e não-redutores), ácido ascórbico, cinzas, cor, atividade de água e rendimento, com a finalidade de se avaliar a influência da temperatura de secagem, espessura da camada de espuma e da concentração de Emustab, através do planejamento experimental fatorial. Determinou-se a isoterma de adsorção de água a 25 °C, da melhor amostra em pó selecionada através do planejamento fatorial, e a ela se ajustaram os modelos de GAB, Oswin e Peleg. Com os resultados obtidos neste trabalho verificou-se que a polpa de cajá integral é ácida e pode ser considerada fonte de vitamina C; trata-se de um fluido pseudoplástico, em que o modelo de Herschel Bulkley foi o que melhor se ajustou aos dados experimentais. Avaliando-se os parâmetros de massa específica, expansão volumétrica e estabilidade da espuma, as três formulações estudadas (1, 2 e 3) se apresentaram dentro dos padrões de secagem em camada de espuma; verificou-se a influência dos aditivos nas características da polpa integral e as espumas apresentaram comportamento pseudoplástico, em que o modelo de Mizrahi-Berk foi o que melhor se ajustou aos dados experimentais. As curvas de secagem das espumas foram influenciadas pela espessura da camada e pela temperatura de secagem. As secagens mais rápidas ocorreram na menor espessura e maior temperatura e apresentaram menor teor de água final; a secagem mais rápida ocorreu na Formulação 3, com maior concentração de Emustab. O modelo de Cavalcanti Mata foi o que melhor se ajustou às curvas de cinética de secagem das espumas. Através do planejamento experimental verificou-se que o melhor pó encontrado foi o do Experimento 2 (polpa de cajá com 3% de Emustab e 2% de Super Liga Neutra; espessura da camada de espuma de 0,5 cm e temperatura de secagem de 60 °C). / The cajá pulp was dryed using foam-mat drying process and results were analyzed using the experimental factorial design. Were prepared formulations of cajá pulp with three different concentrations of the emulsifier Emustab® (1, 2 and 3%) and fixed concentration Super Liga Neutra (2%) additive; this mixture was stirred during 15 minutes until the foam formation. AH samples at the end were analyzed for its chemical, physical and physico-chemical properties. The Formulations 1, 2 and 3% were dried in a stove with air circulation at 60, 70 and 80 °C and thickness 0.5; 1.0 and 1.5 cm. The Page, Henderson & Pabis and Cavalcanti Mata models were used to fit the experimental data. The moisture content, °Brix, pH, acidity, sugars (reducing, total and non-reducing sugars), ascorbic acid, ashes, color, water activity and yield of the powder pulp was determined to study the effect of the drying temperature, foam layer thickness and the emulsifier concentration. From these results, the best sample was selected to study the moisture adsorption isotherm at 25 °C, fitting data by the GAB, Oswin and Peleg models. According the results it can be concluded that the whole cajá pulp is acid and could have its applications as a vitamin C source; furthermore is classified as pseudoplastic fluid, whereby its experimental data was best fítted by the Herschel Bulkley model. It can be stated that the density, volumetric expansion and stability of the foam of the three different formulations were in agreement with the drying standards of foam layers. There was an effect of the additives on the properties of the whole pulp as well as on the different formulations, whereby the formulations presented a pseudoplastic behavior, with its experimental data best fitted by the Mizrahi-Berk model. The drying curves were affected by the thickness of the layer and temperature. It was noticed that thinner layers resulted in higher drying rates with a lower final moisture content. The highest drying rate was obtained by the sample with 3% of the emulsifier. The experimental data of the drying process was best fitted by the Cavalcanti Mata model. According to the experimental factorial design the sample with the concentration of 3% of Emustab® and 2% of Super Liga Neutra, dried with a layer thickness of 0.5 cm at a temperature of 60 °C presented the best results.
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Densidade óptica de pigmento macular em uma amostra da população brasileira / Macular pigment optical density in a brazilian sample

Jorge, Letícia Pinto Coelho 19 September 2017 (has links)
Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2017-09-26T15:36:47Z No. of bitstreams: 2 Dissertação - Letícia Pinto Coelho Jorge - 2017.pdf: 7825738 bytes, checksum: 4eca5b3a59512770f7384ddd353ddb59 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-09-27T11:21:13Z (GMT) No. of bitstreams: 2 Dissertação - Letícia Pinto Coelho Jorge - 2017.pdf: 7825738 bytes, checksum: 4eca5b3a59512770f7384ddd353ddb59 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-09-27T11:21:13Z (GMT). No. of bitstreams: 2 Dissertação - Letícia Pinto Coelho Jorge - 2017.pdf: 7825738 bytes, checksum: 4eca5b3a59512770f7384ddd353ddb59 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-09-19 / Macula lutea is the region of the retina where the yellow pigments lutein and zeaxanthin are concentrated. Oxidative damage seems to be an important factor for exacerbation of several retinal diseases, such as age-related macular degeneration, and a protective role of macular pigment has been postulated. The quantitative study of macular pigment and its distribution are possible through the determination of macular pigment optical density (MPOD). The objective of this study was to determine the mean MPOD value in a sample of the Brazilian population and to evaluate the influence of sex, age, ethnicity, smoking history and refractive status on MPOD values in this sample. A cross-sectional study was performed. Forty-two healthy patients had both eyes photographed using Visucam 500 (Carl Zeiss Meditec, Jena, Germany) in combination with the MPOD module. Four variables were obtained: maximum MPOD, mean MPOD, MPOD volume and MPOD area. Demographic data and life habits were collected. The mean MPOD value in the studied population was 0.13 density unit ± 0.02. MPOD values were not influenced by gender, smoking history or refraction. MPOD values were significantly higher among black patients when compared to caucasians. There was a positive but low correlation between mean MPOD and age. / A mácula lútea é a região da retina onde se concentram os pigmentos amarelos luteína e zeaxantina. Acredita-se que eles sejam um fator de proteção para doenças atribuídas ao estresse oxidativo, como degeneração macular relacionada à idade. O estudo quantitativo do pigmento macular e sua distribuição são possíveis por meio da medida da densidade óptica de pigmento macular (MPOD). O objetivo deste trabalho foi determinar o valor médio de MPOD em uma amostra da população brasileira e avaliar a influência dos fatores sexo, idade, etnia, histórico de tabagismo e status refracional nos valores de MPOD nesta amostra. Foi realizado estudo tipo corte transversal. Quarenta e dois pacientes saudáveis tiveram ambos os olhos fotografados utilizando o Visucam 500 (Carl Zeiss Meditec, Jena, Alemanha) em combinação com o módulo MPOD. Quatro variáveis foram obtidas: MPOD máxima, MPOD média, volume de MPOD e área de MPOD. Foram colhidos dados demográficos e hábitos de vida. O valor médio de MPOD nesta amostra da população brasileira foi de 0,13 unidade de densidade ± 0,02. Os valores de MPOD não foram influenciados pelo sexo, histórico de tabagismo ou refração. Os valores de MPOD foram significativamente maiores entre os pacientes negros, quando comparados aos brancos. Encontrou-se uma correlação positiva, porém baixa, entre o valor de MPOD médio e a idade.
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Comparação das medidas da espessura macular e da camada de fibras nervosas retiniana para detecção de atrofia em banda do nervo óptico através da tomografia de coerência óptica / Comparison of macular thickness and retinal nerve fiber thickness measurements for detection of band atrophy of the optic nerve using optical coherence tomography

Moura, Frederico Castelo 31 August 2007 (has links)
Pacientes com compressão quiasmática apresentam perda das fibras nervosas da retina nasal que decussam no quiasma óptico. Por conseguinte, ocorre perda das fibras nervosas, predominantemente, no setor nasal e temporal do disco óptico, que se manifesta por atrofia em banda do nervo óptico ao exame oftalmoscópico e hemianopsia temporal ao exame de campo visual. Trabalhos anteriores mostraram que o tomógrafo de coerência óptica é capaz de diferenciar pacientes com atrofia em banda do nervo óptico associada à hemianopsia temporal completa de indivíduos normais através da análise da camada de fibras nervosas peripapilar. Estudos em glaucoma têm sugerido que a avaliação da espessura macular poderia ser útil na quantificação da perda neural como um método alternativo ou complementar ao estudo da camada de fibras nervosas da retina. No presente estudo, a espessura macular e da camada de fibras nervosas foram avaliadas pelo tomógrafo de coerência óptica em pacientes com atrofia em banda do nervo óptico e graus variados de hemianopsia temporal. O desempenho dos parâmetros maculares para detecção da atrofia em banda do nervo óptico foi avaliado pela área sob a curva ROC (AROC) e sensibilidades para especificidades fixas e os resultados foram comparados aos parâmetros da camada de fibras nervosas peripapilar. Para identificar os parâmetros do Stratus OCT que apresentaram melhor desempenho para diferenciar pacientes com AB do nervo óptico de indivíduos normais, modelos de regressão logística foram utilizados. A correlação estrutura-função foi realizada entre o grau do defeito temporal e os valores de espessura macular e da camada de fibras peripapilar através do coeficiente de correlação de Spearman. A categorização diagnóstica dos parâmetros da camada de fibras nervosas através do banco de dados normativos foi avaliada pelos valores de sensibilidade e especificidade calculados pelo teste exato de Fisher. Quarenta e quatro olhos com atrofia em banda e 47 olhos normais foram avaliados no estudo. Entre os parâmetros maculares, os parâmetros da retina nasal apresentaram melhor desempenho para detectar atrofia em banda do nervo óptico comparados aos parâmetros da retina temporal. Não houve diferença significante (p=0,32) entre as áreas sob a curva ROC do melhor parâmetro macular (AROC=0,97) e do melhor parâmetro da camada de fibras nervosas retiniana (AROC=0,99). Na avaliação da correlação estrutura-função, os parâmetros da retina nasal apresentaram maior correlação com o defeito campimétrico comparados aos parâmetros da camada de fibras nervosas da retinal. Entre os parâmetros maculares, a espessura nasal média apresentou a maior correlação (rs=0,618). Entre os parâmetros da camada de fibras nervosas da retina, a espessura média apresentou a maior correlação (rs=0,479). Os parâmetros espessura média, espessura nasal e espessura temporal da camada de fibras nervosas da retina apresentaram melhor desempenho diagnóstico baseado na categorização diagnóstica do banco de dados normativos. Os resultados obtidos no estudo mostraram que os parâmetros maculares discriminam olhos com atrofia em banda do nervo óptico em pacientes com graus variados de defeito temporal. Além disso, os parâmetros da retina nasal podem colaborar com o exame perimétrico e os parâmetros da camada de fibras nervosas para o seguimento dos pacientes com compressão quiasmática. / Patients with chiasmal compression present damage of crossed fibers of nasal retina. Therefore, retinal nerve fiber layer loss occurs predominantly on the nasal and temporal sides of the optic disc, a pattern that can be identified on ophthalmoscopy as band atrophy of the optic nerve and on visual field as temporal hemianopia. Previous studies have been demonstrated that optical coherence tomography is able to detect retinal nerve fiber layer loss in patients with lesions of the optic chiasm and complete temporal hemianopia. Studies in glaucoma have been suggested that macular thickness measurements could be useful in quantification of optical nerve axonal loss as alternative or complement method to evaluate the retinal nerve fiber layer. The purpose of the present study was to compare macular thickness and retinal nerve fiber thickness measurements in patients with band atrophy of the optic nerve and different severities of visual field defect using optical coherence tomography. Area under the receiver operating characteristic curve (AROC) and sensitivities at fixed specificities were performed for evaluation of diagnostic accuracy of macular and retinal nerve fiber layer parameters. To identify the best optical coherence tomography measurements to differentiate band atrophy of the optic nerve patients from normal individuals, logistic regression models were performed. Association between optical coherence tomography parameters and temporal field defect were examined by Spearman coefficient of correlation. Fisher\'s exact test was performed to evaluate diagnostic ability of retinal nerve fiber parameters by optical coherence tomography in eyes with band atrophy using comparison with its internal normative database. A total of 44 eyes with band atrophy of the optic nerve and 47 normal eyes were studied. Among macular parameters, nasal retina measurements showed diagnostic accuracy better than temporal retina measurements. No statistically significant difference (p=0.32) was found between areas under ROC curve for the best macular parameter (AROC=0.97) and the best retinal nerve fiber layer parameter (AROC=0.99). Nasal retina parameters correlations were higher than retinal nerve fiber parameters. The highest correlation was observed for the mean nasal thickness (rs=0.618) for macular parameters. In retinal nerve fiber parameters, the highest correlation was observed for the average thickness (rs=0.479). In evaluation of diagnostic ability of normative database, the average thickness parameter demonstrated the highest sensitivity for detection of abnormalities in eyes with band atrophy, followed by the parameters related to the nasal and temporal quadrants. These results suggest that macular thickness measurements discriminate eyes with band atrophy of the optic nerve with different severities of temporal field defect. Results also suggest that nasal retina thickness measurements could potentially be used to evaluate retinal ganglion cell loss in patients with chiasmal compression.

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