Browsing by Author "Sousa, Rita"
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- Bioengineered Temporomandibular Joint Disk Implants: Study Protocol for a Two-Phase Exploratory Randomized Preclinical Pilot Trial in 18 Black Merino Sheep (TEMPOJIMS)Publication . Ângelo, David Faustino; Monje, Florencio Gil; González-García, Raúl; Little, Christopher B; Mónico, Lisete; Pinho, Mário; Santos, Fábio Abade; Carrapiço, Belmira; Gonçalves, Sandra Cavaco; Morouço, Pedro; Alves, Nuno; Moura, Carla; Wang, Yadong; Jeffries, Eric; Gao, Jin; Sousa, Rita; Neto, Lia Lucas; Caldeira, Daniel; Salvado, FranciscoBackground: Preclinical trials are essential to test efficacious options to substitute the temporomandibular joint (TMJ) disk. The contemporary absence of an ideal treatment for patients with severe TMJ disorders can be related to difficulties concerning the appropriate study design to conduct preclinical trials in the TMJ field. These difficulties can be associated with the use of heterogeneous animal models, the use of the contralateral TMJ as control, the absence of rigorous randomized controlled preclinical trials with blinded outcomes assessors, and difficulties involving multidisciplinary teams. Objective: This study aims to develop a new, reproducible, and effective study design for preclinical research in the TMJ domain, obtaining rigorous data related to (1) identify the impact of bilateral discectomy in black Merino sheep, (2) identify the impact of bilateral discopexy in black Merino sheep, and (3) identify the impact of three different bioengineering TMJ discs in black Merino sheep. Methods: A two-phase exploratory randomized controlled preclinical trial with blinded outcomes is proposed. In the first phase, nine sheep are randomized into three different surgical bilateral procedures: bilateral discectomy, bilateral discopexy, and sham surgery. In the second phase, nine sheep are randomized to bilaterally test three different TMJ bioengineering disk implants. The primary outcome is the histological gradation of TMJ. Secondary outcomes are imaging changes, absolute masticatory time, ruminant time per cycle, ruminant kinetics, ruminant area, and sheep weight Results: Previous preclinical studies in this field have used the contralateral unoperated side as a control, different animal models ranging from mice to a canine model, with nonrandomized, nonblinded and uncontrolled study designs and limited outcomes measures. The main goal of this exploratory preclinical protocol is to set a new standard for future preclinical trials in oromaxillofacial surgery, particularly in the TMJ field, by proposing a rigorous design in black Merino sheep. The authors also intend to test the feasibility of pilot outcomes. The authors expect to increase the quality of further studies in this field and to progress in future treatment options for patients undergoing surgery for TMJ disk replacement. Conclusions: The study has commenced, but it is too early to provide results or conclusions.
- Efeito da dieta alimentar no perfil bioquímico do crustáceo decápode Palaemon elegans (Rathke, 1837)Publication . Sousa, RitaA espécie de Palaemon elegans encontra-se largamente distribuída pelo ambiente marinho e numa grande variedade de habitats rochosos. Os indivíduos pertencentes a esta espécie toleram uma vasta gama de salinidade e temperatura, apresentando uma grande versatilidade no que diz respeito aos itens alimentares. Neste estudo pretendeu-se avaliar o efeito da dieta alimentar na composição bioquímica (proteína bruta, gordura total, ácidos gordos e aminoácidos) do tecido muscular de P. elegans e nos respectivos parâmetros de crescimento (incremento em peso, taxa específica de crescimento e taxa de sobrevivência). Para tal, foram consideradas três dietas alimentares (mexilhão, ração semi-seca e ração semi-húmida), as quais foram fornecidas a juvenis de P. elegans cultivados durante 54 dias em condições laboratoriais (temperatura = 24ºC, salinidade = 35‰). Paralelamente ao estudo e servindo como grupo controlo, em 2010 e 2011 foram capturados no campo indivíduos selvagens de P. elegans para os quais foi igualmente estabelecido o respectivo perfil bioquímico. Com o presente estudo, foram evidenciadas elevadas correlações entre o tamanho versus peso e taxa de crescimento dos P. elegans. A análise ANCOVA demonstrou a existência de diferenças significativas (P<0.001) entre todas as taxas de crescimento específicas, sendo a ração semi-seca aquela que proporcionou valores mais elevados (0.044 d-1). A taxa de sobrevivência com maior destaque neste estudo resultou da alimentação dos crustáceos com ração semi-seca (aproximadamente 96%). No perfil bioquímico do músculo de P. elegans as diferenças com maior relevância incidem-se na quantificação de ácidos gordos e aminoácidos, comparativamente com as dietas fornecidas durante o presente estudo. Quanto aos ácidos gordos, constatam-se diferenças notórias entre a quantidade existente nas dietas fornecidas e no músculo de P. elegans para os ácidos eicosapentaenóico e docosahexaenóico na ordem de 95% e 96%, respectivamente. Relativamente à quantificação de aminoácidos, evidenciam-se diferenças estatísticas para prolina existente no músculo de P. elegans alimentados com dieta semi-seca (40,529 ± 1,9510 mg/g) e mexilhão (29,213 ± 5,8577 mg/g) comparativamente com os indivíduos capturados em meio selvagem (6,660 ± 0,1650 mg/g). Este estudo sugere que a dieta que oferece maior benefício para o crescimento sustentável da espécie e rentável para a aquacultura é a dieta semi-seca, a qual deverá ser ajustada pontualmente com ácidos gordos altamente insaturados (HUFA) e polinsaturados (PUFA), bem como de aminoácidos essenciais.
- Effects of bilateral discectomy and bilateral discopexy on black Merino sheep rumination kinematics: TEMPOJIMS – phase 1 – pilot blinded, randomized preclinical studyPublication . Ângelo, David; Gil, Florencio Monje; González-García, Raúl; Mónico, Lisete; Sousa, Rita; Neto, Lia; Caldeira, Inês; Moura, Carla; Francisco, Luís Carlos; Sanz, David; Alves, Nuno; Salvado, Francisco; Morouço, PedroBackground The temporomandibular joint interposal study (TEMPOJIMS) is a rigorous preclinical trial divided in 2 phases. In phase 1 the authors investigated the role of the TMJ disc and in phase 2 the authors evaluated 3 different interposal materials. The present work of TEMPOJIMS - phase 1, investigated the effects of bilateral discectomy and discopexy in sheep mastication and rumination. Methods This randomized, blinded and controlled preclinical trial (in line with the ARRIVE guidelines) was conducted in 9 Black Merino sheep to evaluate changes in mastication and rumination after bilateral discectomy and bilateral discopexy, by comparing with a sham surgery control group. The outcomes evaluated were: (1) absolute masticatory time; (2) ruminant time per cycle; (3) ruminant kinematics, and (4) ruminant area. After baseline evaluation and surgical interventions, the outcomes were recorded over 3 successive days, every 30 days, for 6 months. Results The first month after intervention seemed to be the critical period for significant kinematic changes in the discectomy and discopexy groups. However, 6 months after the bilateral interventions, no significant changes were noticed when compared with the control group. Conclusions In this study, bilateral discectomy and discopexy had no significant effect in mastication and ruminatory movement. The introduction of kinematic evaluation presents a new challenge that may contribute to the improvement of future studies on the TMJ domain.
- The efficacy of MS-222 as anaesthetic agent in four freshwater aquarium fish speciesPublication . Chambel, João; Pinho, Rúben; Sousa, Rita; Ferreira, Tânia; Baptista, Teresa; Severiano, Vera; Mendes, Susana; Pedrosa, RuiThe efficacy of anaesthetic tricaine methanesulfonate (MS-222) was evaluated in four freshwater aquarium fish species, Zebrafish (Danio rerio), Guppy (Poecilia reticulata), Discu (Symphysodon discus) and Green swordtail (Xiphophorus helleri). The correct dose of anaesthetic should induce the plane 4 of anaesthesia in less than 180 s, recovery in less than 300 s and must survive when exposed during 30 min to anaesthetic. Fishes were exposed to six concentrations of anaesthetic (75, 100, 125, 150, 200 and 250 mg L-1) and the time of fish reaching plane 4 of anaesthesia, post exposure recovery, and the percentage of survival when fish were subject to 30 min in the anaesthetic were recorded. The optimal doses varied according to the species: D. rerio - 75, 100 and 125 mg L-1, P. reticulata - 125, 150 and 200 mg L-1, S. discus - 75 and 100 mg L-1 and X. helleri - 125 and 150 mg L-1. The induction time generally decreased significantly with increasing concentration of MS-222 for all of the species evaluated. The recovery time had a tendency to increase with the increase of the MS-222 concentration for D. rerio, P. reticulata and S. discus. On the other hand, X. helleri recovery time decreased with the increase of MS-222 concentration. MS-222 proved to be effective in anaesthesia for all the freshwater ornamental species studied. The main results clearly show that the optimal dose to anesthetize is fish species dependent and it is completely wrong to extrapolate optimal anaesthetic concentrations between different species.
- Lipid oxidation inhibition by natural tocopherols increases the nutritional value of tuna salamiPublication . Sousa, Rita; Pedrosa, Rui; Gil, Maria M.Introduction: The quality attributes of fish products deteriorate due to the lipid oxidation during processing and storage. Tuna salami is highly susceptible to oxidation, which can precipitate health hazards and economic losses in terms of inferior product quality. Methods: The effect of adding different natural antioxidants on the lipid oxidation, colour and fatty acid profile of tuna salami after nine days of storage at 4 ºC was assessed. Three different commercial mixes of tocopherols were added during the production of the tuna salami and samples were sliced and refrigerated for 9 days. Results: The lipid oxidation increased from 0.98 to 4.03 mg of malondialdehyde/kg. The oxidation process was inhibited by DLT-100 and VIT-100; however, RNX10 did not blunt the oxidative process. VIT and dose-limiting toxicity (DLT) reduced the total unsaturated fatty acid reduction. The RNX did not prevent the reduction of the a* value. Conclusion: It was concluded that tocopherols supplementation kept the nutritional value of tuna salami mainly by lipid oxidation inhibition.
- Preclinical randomized controlled trial of bilateral discectomy versus bilateral discopexy in Black Merino sheep temporomandibular joint: TEMPOJIMS e Phase 1- histologic, imaging and body weight resultsPublication . Ângelo, David Faustino; Morouço, Pedro; Gil, Florêncio Monje; Mónico, Lisete; González-Garcia, Raúl; Sousa, Rita; Neto, Lia; Caldeira, Inês; Smith, Margaret; Smith, Susan; Sanz, David; Santos, Fábio Abade dos; Pinho, Mário; Carrapiço, Belmira; Cavaco, Sandra; Moura, Carla; Alves, Nuno; Salvado, Francisco; Little, ChristopherIntroduction: The role of temporomandibular joint (TMJ) surgery is not well defined due to a lack of quality randomized controlled clinical trials, comparing different TMJ surgical treatments with medical and placebo interventions. The temporomandibular joint interposal study (TEMPOJIMS) is a rigorous preclinical trial divided in 2 phases. In phase 1 the authors investigated the role of the TMJ disc and in phase 2 the authors evaluated 3 different interposal materials. The present work of TEMPOJIMS e phase 1, aims to evaluate histopathologic and imaging changes of bilateral discectomy and discopexy in Black Merino sheep TMJ, using a high-quality trial following the ARRIVE guidelines. Material and methods: This randomized, blinded and controlled preclinical trial was conducted in 9 Black Merino sheep to investigate histopathologic (primary outcome), imaging and body weight (secondary outcomes) changes after bilateral discectomy, discopexy and sham surgery. Results: Significant changes were noticed in discectomy group, both in imaging and histopathologic analyses. Body weight changes were most pronounced in the discectomy group in the first 4 months after surgery with recovery to baseline weight 6 months after surgery. Discopexy induced nonsignificant changes in histopathologic, imaging and body weight analyses. Conclusions: This study reinforces the importance of developing an effective interposal material to substitute the TMJ disc and the need to explore the molecular mechanisms that underlie TMJ cartilage degeneration. The study design proposed in TEMPOJIMS represents an important progress towards future rigorous TMJ investigations.
- A randomized controlled preclinical trial on 3 interposal temporomandibular joint disc implants: TEMPOJIMS—Phase 2Publication . DF, Angelo; Wang, Y.; Morouço, Pedro; Monje, Florencio; Mónico, Lisete; González‐Garcia, Raúl; Moura, Carla; Alves, Nuno; Sanz, David; Gao, Jin; Sousa, Rita; Neto, Lia; Faísca, Pedro; Salvado, Francisco; López Peña, Monica; Permuy, Maria; Munñoz, FernandoThe effort to develop an effective and safe temporomandibular joint (TMJ) disc substitute has been one of the mainstreams of tissue engineering. Biodegradable customized scaffolds could approach safety and effectiveness to regenerate a new autologous disc, rather than using non‐biodegradable materials. However, it is still technically challenging to mimic the biomechanical properties of the native disc with biodegradable polymers. In this study, new 3D tailored TMJ disc implants were developed: (1) Poly(glycerol sebacate) (PGS) scaffold reinforced with electrospun Poly(εcaprolactone) (PCL) fibers on the outer surface (PGS+PCL); (2) PCL and polyethylene glycol diacrylate (PEGDA) (PCL+PEGDA); and (3) PCL. The TMJ im plants were tested in a randomized preclinical trial, conducted in 24 black Merino sheep TMJ, perfoming bilateral interventions. Histologic, imaging, and kinematics analysis was performed. No statistical changes were observed between the PGS +PCL disc and the control group. The PCL+PEGDA and PCL groups were associated with statistical changes in histology (p = 0.004 for articular cartilage mid‐layer; p = 0.019 for structure changes and p = 0.017 for cell shape changes), imaging (p = 0.027 for global appreciation) and dangerous material fragmentation was observed. No biomaterial particles were observed in the multi‐organ analysis in the different groups. The sheep confirmed to be a relevant animal model for TMJ disc surgery and regenerative approaches. The PCL and PCL+PEGDA discs presented a higher risk to increase degenerative changes, due to material fragmentation. None of the tested discs regenerate a new autologous disc, however, PGS+PCL was safe, demonstrated rapid resorption, and was capable to prevent condyle degenerative changes.