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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.
51

Micobactérias não tuberculosas em cirurgias: desafio passível de enfrentamento no Brasil? / Nontuberculous mycobacteria in surgeries: challenge liable to be faced in Brazil?

Danielle Bezerra Cabral 16 July 2010 (has links)
Micobactérias não tuberculosas (MNT) são microrganismos ubíquos e reconhecidos como contaminantes de sistemas de água em estabelecimentos de assistência à saúde, bem como, dispositivos cirúrgicos e medicamentos injetáveis. Sua ocorrência representa uma emergência epidemiológica e sanitária, especialmente em pacientes submetidos a procedimentos cirúrgicos. Frente ao exposto, objetivou-se avaliar a produção do conhecimento científico acerca da ocorrência de infecções por MNT em pacientes submetidos a procedimentos cirúrgicos. A prática baseada em evidências representou o referencial teórico-metodológico e, como recurso para obtenção destas evidências utilizou-se a revisão integrativa da literatura nas bases de dados Lilacs, Medline/Pubmed, ISI Web of Science e Biblioteca Cochrane. Totalizaram-se 24 publicações nos últimos trinta anos, com 15 (62,5%) no idioma inglês, os demais no português. No que se refere ao delineamento dos estudos, observou-se que os mais frequentes foram: 29,2% relatos de caso, 20,8% estudos transversais e 12,5% estudos metodológicos e quaseexperimentais. A análise dos estudos culminou em três categorias temáticas sendo 08 (33,3%) relacionadas aos tipos de cirurgias, 07 (29,2%) sobre identificação das espécies por métodos microbiológicos e/ou moleculares e 09 (37,5%) medidas de prevenção e controle. Ainda como subcategorias têm-se: a vigilância pós-alta, terapêutica com antibióticos e uso de glutaraldeído. Entre os microrganismos destacam-se com 37,5% Mycobacterium chelonae, 33,3%, M. abscessus e 25% M. fortuitum. Cirurgias oftalmológicas, estéticas, cardíacas e procedimentos laparoscópicos e artroscópicos foram as mais investigadas. Diante do contexto terapêutico, a indicação é realizada empiricamente ao longo prazo, podendo incluir desbridamento cirúrgico de tecidos infectados. Na panorâmica da identificação das espécies, a eletroforese em gel de campo pulsado (PFGE) é considerada padrão-ouro devido seu alto poder discriminatório de algumas cepas bacterianas, porém com limitações. Com base nas publicações analisadas, conclui-se que não se tem um panorama nacional talvez pela inoperância do sistema de vigilância pós-alta, inexistência de critérios clínicos e bacteriológicos uniformizados em todo o território e, também pela falta de integração entre a clínica e o laboratório. Adiciona-se que aplicação de metodologias moleculares possibilitaria definir a diversidade das espécies de micobactérias que não puderam ser identificadas pelos métodos clássicos. Uma publicação sobre a situação nacional das MNTs em cirurgias é fundamental para a uma conduta correta no diagnóstico e tratamento de micobacterioses. / Nontuberculous mycobacteria (NTM) are ubiquitous microorganisms recognized as contaminants of water systems in health care services, as well as surgical devices and injectable medications. Its occurrence represents an epidemiological and sanitary emergency, especially in patients subject to surgical procedures. This study aimed to evaluate the production of scientific knowledge on the occurrence of infections caused by NTM in patients subject to surgical procedures. Evidence-based practice was the theoreticalmethodological framework used, and integrative literature review was used to obtain evidences in the following databases: Lilacs, Medline/Pubmed, ISI Web of Science and Cochrane Library. In total, 24 publications were found in the last thirty years, being 15 (62.5%) in english and the others in portuguese. Regarding the design of the studies, most (29,2%) were case reports, (20,8%) cross-sectional studies and (12,5%) methodological and quasi-experimental studies. The analysis of the studies resulted in three thematic categories: 08 (33.3%) types of surgery, 07 (29.2%) identification of the species by microbiological and/or molecular methods and 09 (37.5%) prevention and control measures. The following subcategories were identified in prevention and control: vigilance after discharge, therapy with antibiotics and use of glutaral. The most researched surgeries were ophthalmologic, aesthetic, cardiac and laparoscopy and arthroscopy. The presence of the following microorganisms is highlighted: Mycobacterium chelonae (37.5%), M. abscessus (29.2%) and M. fortuitum (25%). Pulsed-field gel electrophoresis (PFGE) is considered gold-standard in the identification of certain bacterial strains. The use of molecular techniques permits to define the diversity of the species of mycobacteria that cannot be identified by the classical methods. Regarding the therapy, in general the indication is empirically determined in long-term, and can include surgical debridement of infected tissues. Based on the analyzed publications, it is concluded that there is not a national panorama, either due to the failure of the surveillance system after discharge, the lack of clinical and bacteriological criteria uniform for the entire country or the lack of integration between clinics and laboratories.
52

Perfil da fala de pacientes submetidos à palatoplastia primária / Speech characteristics of patients submitted to primary palatoplasty

Katia Ignacio Menegueti 20 September 2016 (has links)
Diversas alterações anatômicas e funcionais são observadas como consequência da fissura labiopalatina, ocasionando alterações em relação ao crescimento do terço médio da face, à audição e a funcionalidade do esfíncter velofaríngeo. Esta última interfere diretamente nas funções de sucção, deglutição e fala. O objetivo deste estudo é caracterizar o perfil da fala de pacientes submetidos à palatoplastia primária em um hospital escola de referência da cidade de São Paulo, levando-se em consideração a idade do paciente no momento da cirurgia. Os objetivos específicos são a análise da eficácia da cirurgia; a resposta muscular em relação ao procedimento cirúrgico; e o momento mais adequado para a intervenção cirúrgica. Participaram do estudo 97 indivíduos com diagnóstico de fissura palatina não sindômica associada ou não à fissura de lábio, encaminhados para avaliação fonoaudiológica, conforme demanda do serviço. Estes foram divididos em dois grupos: o grupo precoce (GP) e grupo tardio (GT). O GP foi composto por indivíduos que realizaram a palatoplastia primária até o segundo ano de vida (43 participantes) e o GT por indivíduos que realizaram a palatoplastia primária tardiamente, após os dois anos de idade (54 participantes). Os participantes foram submetidos à rotina de avaliação fonoaudiológica na Unidade de Fonoaudiologia do ICHC-FMUSP, realizada por um fonoaudiólogo treinado e com experiência na área. Dentre os parâmetros avaliados encontram-se a presença de alterações de ressonância, o grau de alteração da ressonância, a presença de distúrbios articulatórios compensatórios, a presença de ronco nasal, a presença de fraca pressão intraoral, a presença de emissão de ar e o grau de inteligibilidade da fala, variáveis consideradas para este estudo. Essas características foram classificadas inicialmente como \"presente\" ou \"ausente\" nas diferentes amostras de fala de cada participante, e posteriormente, quando aplicável, determinado seu grau de comprometimento. Após a realização do estudo verificou-se que: 1) Em relação à caracterização geral dos participantes: 1.1) Idade média da palatoplastia: GP = 1,4 anos; GT = 11,5 anos; 1.2) Idade média da primeira avaliação fonoaudiológica no serviço: GP = 12,3 anos; GT = 19,8 anos; 1.3) Gênero: predomínio do gênero masculino para GP (55,8%) e feminino para GT (53,7%); 2) Quanto à caracterização da fala (análise geral): 2.1) Ressonância: alterada em 69,8% dos participantes do GP e em 85,2% do GT, sem diferença estatisticamente significante; 2.2) Hipernasalidade: 1) presente em 72,1% dos participantes do GP, em grau leve em 48,4%, moderado em 41,9% e grave em 9,7%; 2) presente em 85,2% do GT, em grau leve em 32,6%, moderado em 43,5% e grave em 23,9%. Não foi observada diferença estatisticamente significante entre os grupos; 2.3) Hiponasalidade: presente em 7,4% do GT, todos em grau leve; 2.4) Ronco nasal: presente em 14% dos participantes do GP e em 5,6% do GT, sem diferença estatisticamente significante; 2.5) Fraca pressão intra oral: presente em 30,2% dos participantes do GP e em 44,4% do GT, sem diferença estatisticamente significante; 2.6) Emissão de ar nasal audível: presente em 23,3% dos participantes do GP e em 31,5 do GT, sem diferença estatisticamente significante; 2.7) Inteligibilidade de fala: 1) prejudicada em 69,8% dos participantes do GP, em grau leve em 56,7%, moderado em 30% e grave em 13,3%; 2) prejudicada em em 83,3% do GT, em grau leve em 24,4%, moderado em 46,7% e grave em 28,9%. Não foi observada diferença estatisticamente significante entre os grupos; 2.8) DACs: presente em 55,8% dos participantes de GP e em 75,9% de GT, com diferença significante entre os grupos (número de fonemas alterados - p=0,020); 3) Em relação à caracterização da fala (considerando tipo de fissura): ausência de resultados estatisticamente significativos entre os grupos estudados quando se levou em consideração as variáveis citadas e os tipos de fissuras; 4) Quanto à conduta fonoaudiológica após a avaliação: a conduta mais indicada foi a fonoterapia, seguida pelo acompanhamento longitudinal (alta assistida), indicação de novo procedimento cirúrgico, e alta (propriamente dita). Diante do apresentado, foi possível caracterizar o perfil geral e de fala dos pacientes submetidos à palatoplastia primária do referido hospital escola, referência de atendimento à pacientes fissurados na cidade de São Paulo. Observa-se, de forma geral, prejuízo significativo na fala dos participantes do estudo, sendo evidenciado diferença estatisticamente significante entre os resultados do procedimento precoce e tardio somente para a presença de DACs. A variável ressonância apresentou resultados estatísticos marginais, indicando tendência à diferenciação dos grupos também em relação à essa alteração. Conclui-se que a realização da cirurgia foi benéfica para os participantes, independentemente do momento da intervenção, com melhores resultados em idade anterior aos 2 anos de vida. No entanto, a resposta muscular em relação ao procedimento pode variar, chegando a não ser satisfatória em alguns casos / Several anatomic and functional alterations are observed as consequences of cleft lip and palate, causing alterations related to the growth of the medium third of the face, hearing, and the Velopharyngeal Sphincter function. This last one interferes directly with the functions of suction, deglutition, and speech. The objective of this study is to determine the speech profile of patients submitted to primary palatoplasty, in a benchmark school-hospital in Sao Paulo city, taking into consideration the patient\'s age at the moment of surgery. The specific objectives are: the analysis of the effectiveness of surgery; the muscular response related to the surgical procedure; and the most suitable moment for surgical intervention. 97 subjects with nonsyndromic cleft palate diagnosis associated or not with cleft lip participated in this study and they were referred to a speech language evaluation on demand. They were divided into two groups: the early group (EG) and the late group (LG). The EG was composed by subjects who have undergone primary palatoplasty until the second year of life (43 subjects) and the LG was made by those who had the surgery lately, after two years old (54 subjects). The participants were submitted to a speech language routine in the Speech Language service at ICHC-FMUSP with an experienced and well-trained speech language pathologist. Among the evaluated parameters, there were: existence of abnormal nasal resonance, degrees of abnormal nasal resonance, existence of articulatory compensatory disturbs (ACD), existence of nasal snoring, existence of weak intra-oral air pressure, existence of air emission, and degrees of speech intelligibility. These parameters were initially classified as \"present\" or \"absent\" in the different speech samples of each subject, and subsequently, when applicable, her/his degree of impairment was determined. After carrying through this study, it showed that: 1) according to the subjects\' general characterization: 1.1) average palatoplasty age: EG = 1.4 years old; LG = 11.5 years old; 1.2) Average age on first speech language evaluation in the service: EG = 12.3 years old; LG = 19.8 years old; 1.3) Gender: predominance of male subjects in PG (55.8%) and female subjects in LG (53.7%); 2) concerning the characterization of speech (general analysis): 2.1) abnormal nasal resonance in 69.8% of EG subjects and 85.2% of LG subjects, without any statistical significant difference; 2.2) hypernasality: 1) present in 72.1% of PG subjects, 48.4% in mild, 41.9% in moderate and 9.7% in severe levels; 2) present in 85.2% of LG subjects, 35.6% in mild, 43.5% in moderate and 23.9% in severe levels. It was not showed any statistical significant difference between the groups; 2.3) hyponasality: present in 7.4% of EG, all mild level; 2.4) Nasal snoring: present in 14% of EG and in 5.6% of LG, without any statistical significant difference; 2.5) weak intra-oral air pressure: present in 30.2% of EG and in 44.4% of LG without any statistical significant difference; 2.6) audible air emission: present in 23.3% of EG and in 31.5% of LG, without any statistical significant difference; 2.7) speech intelligibility: 1) affected in 69.8% of EG, 56.7% in mild, 30% moderate and 13.3% severe levels; 2) affected in 83.3% of LG, 24.4% in mild, 46.7% in moderate and 28.9% in severe levels. There was not showed any statistical significant difference between groups; 2.8) ACDs: present in 55.8% of EG and in 75.9% of LG with a statistical significant difference between groups (number of phonemes errors - p=0.020); 3) concerning the speech characterization (considering cleft type): absence of statistical significant results between the studied groups when taking into consideration the cited varies and cleft types; 4) About the speech language approach after the evaluation: the most indicated one was the speech therapy followed by long-term monitoring (assisted discharge), indication of new surgical procedure, and actual discharge. It was possible to characterize the general and speech characteristics of the patients submitted to primary palatoplasty in the cited school-hospital, benchmark in cleft patients in Sao Paulo city. It was observed, all in all, significant impairment in the speech of these subjects, being evident the statistical significant difference between the results of the precocious and late groups only for the existence of ACDs. The variable nasal resonance presented minimal statistical significant results which indicated a tendency to differentiate the groups also regarding this alteration. In conclusion, the surgery was beneficial to the subjects independently of the moment of intervention, with better results in ages younger than two years old. Although, the muscular response regarding this procedure might vary, not being satisfactory in a few cases
53

Tratamento endoscópico versus cirúrgico para adenomas de papila: revisão sistemática e metanálises / Endoscopic versus surgical treatment of ampullary adenomas: systematic review and meta-analysis

Mendonça, Ernesto Quaresma 28 April 2017 (has links)
Objetivos: Avaliar os desfechos da ressecção endoscópica em comparação à cirurgia no tratamento dos adenomas de papila. Métodos: Foi realizada uma revisão sistemática com metanálise de acordo com as recomendações do Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). As bases de dados Medline, Embase, Cochrane, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL) foram escaneadas. Os estudos incluíram pacientes com adenoma de papila e dados de comparação dos tratamentos endoscópico e cirúrgico para os seguintes desfechos: Ressecção primária completa; Sucesso primário; Recorrência; Sucesso final; e Complicações. A análise foi baseada em modelos de efeito randômico e fixo. Resultados: Cinco estudos de coorte retrospectivo foram selecionados, com um total de 465 pacientes. Todos os estudos tinham dados de ressecção primária completa disponível, mostrando uma diferença favorável ao tratamento cirúrgico (Diferença de riscos = -0,22; Intervalo de confiança de 95% = -0,41 a -0,04). Dados de Sucesso primário também foram identificados em todos os cinco estudos. A análise mostrou que a abordagem cirúrgica supera o tratamento endoscópico neste desfecho (DR = -0,13; IC 95% = -0,24 a -0,02). Dados de recorrência foram encontrados em todos os estudos (465 pacientes), com benefício para o tratamento cirúrgico (DR = 0,12; IC 95% = 0,01 a 0,22). Analisando o desfecho de Sucesso final, disponível em todos os estudos, não encontramos diferença entre as duas abordagens terapêuticas (DR = -0,06; IC 95% = -0,15 a 0,04). Três estudos (251 pacientes) apresentaram dados de complicação, e a análise não mostrou diferença entre os tratamentos endoscópico e cirúrgico (DR = -0,15; IC 95% = -0,53 a 0,23), sem a possibilidade de descartar o viés de seleção para este desfecho. Conclusões: Considerando os desfechos de ressecção primária completa, sucesso primário e recorrência na comparação do tratamento cirúrgico com o tratamento endoscópico para adenomas de papila, a abordagem cirúrgica tem resultados significativamente melhores. Com relação ao sucesso final, não houve diferença entre os dois tratamentos. No desfecho das taxas de complicação, esta revisão sistemática não permite uma conclusão confiável devido à presença de alta heterogeneidade e provável viés de publicação nesta comparação / Objectives: To address the outcomes of endoscopic resection compared to surgery in the treatment of ampullary adenomas. Methods: A systematic review and meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Medline, Embase, Cochrane, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were scanned. Studies included patients with ampullary adenomas and comparison data considering endoscopic treatment and surgery for the following outcomes: Complete primary resection; Primary success; Reccurence; Final success; and Complications. The analysis were based on both random and fixed effects model. Results: Five retrospective cohort studies were selected, with 465 patients. All five studies had complete primary resection data available, showing a difference that favours surgical treatment (Risk Difference = -0.22, 95% Confidence Interval = -0.41 to -0.04). Primary success data were identified in all five studies too. Analysis showed that surgical approach overcome endoscopic treatment in this outcome (RD = -0.13, 95% CI = -0.24 to -0.02). Recurrence data was found in all studies (465 patients), with benefit for the surgical treatment (RD = 0.12, 95% CI = -0.01 to 0.22). Analyzing the final success outcome, available in all studies, we found no difference between the two therapeutic approaches (RD = -0.06, 95% CI = -0.15 to 0.04). Three studies (251 patients) presented complication data and analysis shown no difference between the approaches (RD = -0.15, 95% CI = -0.53 to 0.23), not discarding the possibility of presence of selection bias for this outcome. Conclusions: Considering complete primary resection, primary success and recurrence outcomes, surgical approach achieves significantly better results. Regarding the final success, there was no difference between the two treatments. Addressing complication data, this systematic review does not allow for a reliable conclusion due to the presence of high heterogeneity and likely publication bias in this comparison
54

The Humanized Mouse Model: The Study of the Human Alloimmune Response: A Dissertation

King, Marie A. 22 May 2008 (has links)
The transplantation of allogeneic cells and tissues for the treatment of human disease has been a life-saving procedure for many thousands of patients worldwide. However, to date, neither solid organ transplantation nor bone marrow transplantation have reached their full clinical potential. Significant limitations to the advancement of clinical transplantation stem from our current inability to prevent the rejection of allogeneic tissues by the immune system of the host. Similarly, in patients that receive allogeneic bone marrow transplants, we cannot permanently prevent the engrafted immune system from mounting a response against the patient. This problem, termed graft versus host disease is the most prevalent cause of morbidity and mortality in recipients of allogeneic bone marrow transplants. Clinically, we rely on lifelong immunosuppression to prolong survival of allogeneic tissues within the host. Our currently available therapeutics burden patients with side-effects that range from being unpleasant to life-threatening, while in most cases offering only a temporary solution to the problem of alloimmunity. Efforts are underway to develop protocols and therapeutics that more effectively prevent the pathology associated with alloimmunity. To minimize patient risk, extensive pre-clinical studies in laboratory animals are conducted to predict clinical responses. In the case of immunologic studies, many of these pre-clinical studies are carried out in murine models. Unfortunately, studies of murine immunity often do not predict outcomes in the clinic. One approach to overcome this limitation is the development of a small animal model of the human immune system. In this dissertation, we hypothesized that NOD-scid IL2rγnull mice engrafted with human peripheral blood mononuclear cells (PBMC), termed the hu-PBMC-NOD-scid IL2rγnull model, would provide a model that more accurately reflects human immunity in vivo than other models currently available. To investigate this possibility, we first investigated whether NOD-scid IL2rγnull mice were able to support the engraftment of human PBMC. We found that NOD-scid IL2rγnull mice engraft with human PBMC at much higher levels then the previous gold standard model, the NOD-scid mouse. We then investigated the kinetics of human cell engraftment, determined the optimal cell dose, and defined the influence of injection route on engraftment levels. Even at low PBMC input, NOD-scid IL2rγnullmice reproducibly support high levels of human PBMC engraftment. In contrast to previous stocks of immunodeficient mice, we observed low intra- and interdonor variability of engraftment. We next hypothesized that the human PBMC engrafted in NOD-scid IL2rγnull mice were functional and would reject transplanted allogeneic human tissues. To test this, human islets were transplanted into the spleen of chemically diabetic NOD-scid IL2rγnull mice with or without intravenous injection of HLA-mismatched human PBMC. In the absence of allogeneic PBMC, the human islets were able to restore and maintain normoglycemia. In contrast, human islet grafts were completely rejected following injection of HLA-mismatched human PBMC as evidenced by return to hyperglycemia and loss of human C-peptide in the circulation. Thus, PBMC engrafted NOD-scid IL2rγnull mice are able to provide an in vivomodel of a functional human immune system and of human islet allograft rejection. The enhanced ability of NOD-scid IL2rγnull mice to support human cell engraftment gave rise to the possibility of creating a model of graft versus host disease mediated by a human immune system. To investigate this possibility, human PBMC were injected via the tail vein into lightly irradiated NOD-scid IL2rγnull mice. We found that in contrast to previous models of GVHD using human PBMC-injected immunodeficient mice, these mice consistently (100%) developed GVHD following injection of as few as 5x106PBMC, regardless of the PBMC donor used. We then tested the contribution of host MHC in the development of GVHD in this model. As in the human disease, the development of GVHD was highly dependent on host expression of MHC class I and class II molecules. To begin to evaluate the extent to which the PBMC-engrafted NOD-scid IL2rγnull humanized mouse model of GVHD represents the clinical disease, we tested the ability of a therapeutic in clinical trials to modulate GVHD in these mice. In agreement with the clinical experience, we found that interrupting the TNFα signaling cascade with etanercept delayed the onset and severity of disease in this model. In summary, we conclude that humanized NOD-scid IL2rγnull mice represent an important surrogate for investigating in vivo mechanisms of both human islet allograft rejection and graft versus host disease.
55

The Genetic Basis of Resistance to Transplantation Tolerance Induced by Costimulation Blockade in NOD Mice: a Dissertation

Pearson, Todd 17 March 2003 (has links)
The NOD mouse is a widely studied model of type 1 diabetes. The loss of self-tolerance leading to autoimmune diabetes in NOD mice involves at least 27 genetic loci. Curing type I diabetes in mice and humans by islet transplantation requires overcoming both allorejection and recurrent autoimmunity. This has been achieved with systemic immunosuppression, but tolerance induction would be preferable. In addition to their genetic defects in self-tolerance, NOD mice resist peripheral transplantation tolerance induced by costimulation blockade using donor-specific transfusion and anti-CDl54 antibody. Failure has been attributed to the underlying autoimmunity, assuming that autoimmunity and resistance to transplantation tolerance have a common basis. Hypothesizing that these two abnormalities might be related, we investigated whether they had a common genetic basis. Diabetes-resistant NOD and C57BL/6 stocks congenic for various reciprocally introduced Idd loci were assessed for their ability to be tolerized. Surprisingly, in NOD congenic mice that are almost completely protected from diabetes, costimulation blockade failed to prolong skin allograft survival. In reciprocal C57BL/6 congenic mice with NOD-derived Idd loci, skin allograft survival was readily prolonged by costimulation blockade. Unexpectedly, we observed that (NOD x C57BL/6)F1 mice, which have no diabetes, nonetheless resist induction of tolerance to skin allografts. Further analyses revealed that the F1 mice shared the dendritic cell maturation defects and abnormal CD4+ T cell responses of the NOD but had lost its defects in macrophage maturation and NK cell activity. Finally, using a genome wide scan approach, we have identified four suggestive markers in the mouse genome that control the survival of skin allografts following DST and anti-CD154 mAb therapy. We suggest that mechanisms controlling autoimmunity and transplantation tolerance in NOD mice are not completely overlapping and are potentially distinct, or that the genetic threshold for normalizing the transplantation tolerance defect is higher than that for preventing autoimmune diabetes. We conclude that resistance to allograft tolerance induction in the NOD mouse is not a direct consequence of overt autoimmunity and that autoimmunity and resistance to costimulation blockade-induced transplantation tolerance phenotypes in NOD mice are not under identical genetic control.
56

Toll-Like Receptors: Target of Hepatitis C Virus: A Dissertation

Chang, Serena Soyoung Yunmee 08 August 2008 (has links)
Hepatitis C Virus (HCV) is the primary cause of liver transplantation due to its chronic nature in up to eighty percent of infected cases. Around 3 percent of the world’s population is infected with HCV. Treatment for HCV is a combined Ribavirin and interferon-α (IFN-α) therapy effective in only fifty to eighty percent of patients depending on HCV genotype. The growing health concern with this disease is the lack of a cure despite liver transplantation. HCV targets hepatocytes, liver cells, but is not cytolytic. HCV has been shown to induce end stage liver disease through sustained inflammation from the host’s immune system in the liver. One of the key dilemmas in HCV research and the search for fully effective treatments or vaccines is the lack of animal models. HCV infectivity and disease is limited to primates, most specifically to humans, which cannot be fully replicated in any other living being. The mechanisms for HCV evasion or activation of the immune system are complex, many and discoveries within this field are crucial to overcoming this destructive hepatic infection. Toll-like receptors (TLR) are cellular activators of the innate immune system that have been a target of HCV. Activated TLRs trigger both the inflammatory and anti-viral pathways to produce inflammatory cytokines and interferons. HCV proteins have been reported to activate a number of TLRs in a variety of cell types. In order to identify possible targets of HCV within the TLR family, we first characterized TLR presence and function in both human hepatic carcinoma cell lines and purified primary human hepatocytes. RNA from TLRs 1-10 was observed to varying degrees in both the hepatoma cell lines and the primary hepatocytes. We show the extracellular and/or intracellular presence of TLR2, TLR1, TLR3 and TLR7 proteins in hepatoma cell lines. TLR3 and TLR7 are located within the endosome and recognize viral RNA products. We recently reported that TLR2-mediated innate immune signaling pathways are activated by HCV core and NS3 proteins. TLR2 activation requires homo- or heterodimerization with either TLR1 or TLR6. We show NF-κB activation in hepatoma cells by TLR2/1, TLR2/6 ligand and HCV protein stimulation. In primary hepatocytes, HCV proteins induced both IL-8 and IL-6 production. We also show that primary hepatocytes initiate a Type 1 IFN response in addition to IL-8 and IL-6 production upon stimulation with a TLR7/8 ligand. Human hepatoma and primary hepatocytes are responsive to TLR2, TLR1, TLR6, TLR7/8 ligands and HCV proteins. Activation of these TLRs may contribute to the inflammatory mediated destruction caused by HCV or could be targets of HCV contributing to its immune evasion. We found previously that hepatoma cells and primary hepatocytes are responsive to TLR2 ligands and HCV proteins. We also reported that TLR2 is activated by HCV proteins. Here we aimed to determine whether TLR2 coreceptors participated in cellular activation by HCV core or NS3 proteins. By designing siRNAs targeted to TLR2, TLR1 and TLR6, we showed that knockdown of each of these receptors impairs pro- and anti-inflammatory cytokine activation by TLR-specific ligands as well as by HCV core and NS3 proteins in Human Embryonic Kidney cells (HEK/TLR2) and in primary human macrophages. We found that HCV core and NS3 proteins induced TNF-α and IL-10 production in human monocyte-derived macrophages, which was impaired by TLR2, TLR1 and TLR6 knockdown. Contrary to human data, results from TLR2, TLR1 or TLR6 knockout mice indicated that the absence of TLR2 and its coreceptor TLR6, but not TLR1, prevented the HCV core and NS3 protein-induced peritoneal macrophage activation. TLR2 may utilize both TLR1 and TLR6 coreceptors for HCV core- and NS3-mediated activation of macrophages and innate immunity in humans. These results imply that multiple pattern recognition receptors could participate in cellular activation by HCV proteins contributing to inflammatory disease. Two critical factors in chronic HCV infection are inflammatory disease and immune evasion. We have demonstrated that TLR2 and its co-receptors play a role in inflammatory-mediated induction via HCV NS3 and core administration. It has recently been shown that HCV targets the TLR3 pathway to aid in immune evasion. TLR3 is only one of four viral recognition receptors located within the endosome and it is plausible that HCV may target others. We hypothesized that HCV infection may interfere with the expression and function of TLR7, a sensor of single stranded RNA. Investigating any effect on TLR7 by HCV may reveal a new mechanism for HCV immune evasion. Low levels of both TLR7 mRNA and protein were measured in HCV replicating cells compared to control cells while reducing HCV infection with either IFNα or restrictive culture conditions restored the decreased TLR7 expression. Downstream of the TLR7 pathway, an increased baseline IRF7 nuclear translocation was observed in HCV replicating cells compared to controls. Stimulation with a TLR7 ligand, R837, resulted in significant IRF7 nuclear translocation in control cells. In contrast, HCV replicating cells showed impaired IRF7 activation. Use of RNA polymerase inhibitors on hepatoma cells, control and HCV replicating, revealed a shorter TLR7 half life in HCV replicating cells compared to control cells which was not seen in TLR5 mRNA. These data suggest that reduced TLR7 expression, due to RNA instability, directly correlates with HCV replication and results in impaired TLR7-induced IRF7-mediated cell activation. In conclusion, Hepatitis C Virus manipulates specific Toll-like receptors’ expression and their signaling pathways to induce cytokine production. HCV utilizes surface receptors TLR2 and its co-receptors which once activated could contribute to inflammatory disease by production of inflammatory cytokines and possibly immune evasion. HCV down-regulates TLR7, a viral recognition receptor, by decreasing mRNA stability which could facilitate evasion of host immune surveillance.
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Viral Abrogation of Stem Cell Transplantation Tolerance Causes Graft Rejection and Host Death by Different Mechanisms: A Dissertation

Forman, Daron 22 May 2002 (has links)
Tolerance-based stem cell transplantation using sub-lethal conditioning is being considered for the treatment of human disease, but safety and efficacy remain to be established. In order to study these two issues, we first established that mouse bone marrow recipients treated with sub-lethal irradiation plus transient blockade of the CD40-CD154 costimulatory pathway develop permanent hematopoietic chimerism across allogeneic barriers. Our conditioning regimen of 6 Gy irradiation, a short course of anti-CD154 mAb and 25 million fully allogeneic BALB/c bone marrow cells consistently produced long-term, stable, and multilineage chimerism in C57BL/6 recipients. Furthermore, chimeric mice displayed donor-specific transplantation tolerance, as BALB/c skin allografts were permanently accepted while third-party CBA/JCr skin allografts were promptly rejected. We next determined both the safety and efficacy of this protocol by infecting chimeric mice with lymphocytic choriomeningitis virus (LCMV) either at the time of transplantation or at several time points afterwards. Infection with LCMV at the time of transplantation prevented engraftment of allogeneic, but not syngeneic, bone marrow in similarly treated mice. Surprisingly, infected allograft recipients also failed to clear the virus and died. Post-mortem study revealed hypoplastic bone marrow and spleens. Hypoplasia and death in these mice required the combination of 6 Gy irradiation, LCMV infection on the day of transplantation, and an allogeneic bone marrow transplant but did not require the presence of anti-CDl54 mAb. Allochimeric mice infected with LCMV 15 days after transplantation were able to survive and maintain their bone marrow graft, indicating that the deleterious effects of LCMV infection on host and graft survival are confined to a narrow window of time during the tolerization and transplantation process. The final section of this thesis studied the mechanisms of graft rejection and death in sublethally irradiated recipients of allogeneic bone marrow and infection with LCMV at the time of bone marrow transplantation. Infection of interferon-α/β receptor knockout mice at the time of transplantation prevented the engraftment of allogeneic bone marrow, but the mice survived. Therefore, IFN-αβ is involved in the development of marrow hypoplasia and death, whereas a second mechanism is involved in blocking the development of chimerism in these mice. Through the use of depleting mAb's and knockout mice we demonstrate that three types of recipients survived and became chimeric after being given sublethal irradiation, anti-CD154 mAb, an allogeneic bone marrow transplant and a day 0 LCMV infection: mice depleted of CD8+ T cells, CD8 knockout mice, and TCR-αβ knockout mice. Our data indicate that the mediator of bone marrow allograft destruction in LCMV-infected mice treated with costimulatory blockade is a radioresistant CD8+ NK1.1- TCRαβ+ T cell. We conclude that a non-cytopathic viral infection at the time of transplantation can prevent engraftment of allogeneic bone marrow and result in the death of sub-lethally irradiated mice treated with costimulation blockade. The abrogation of allogeneic bone marrow engraftment is mediated by a population of CD8+ NK1.1- TCRαβ+ T cells and the mediator of hypoplasia and death is viral induction of IFN-αβ.
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Tratamento endoscópico versus cirúrgico para adenomas de papila: revisão sistemática e metanálises / Endoscopic versus surgical treatment of ampullary adenomas: systematic review and meta-analysis

Ernesto Quaresma Mendonça 28 April 2017 (has links)
Objetivos: Avaliar os desfechos da ressecção endoscópica em comparação à cirurgia no tratamento dos adenomas de papila. Métodos: Foi realizada uma revisão sistemática com metanálise de acordo com as recomendações do Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). As bases de dados Medline, Embase, Cochrane, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL) foram escaneadas. Os estudos incluíram pacientes com adenoma de papila e dados de comparação dos tratamentos endoscópico e cirúrgico para os seguintes desfechos: Ressecção primária completa; Sucesso primário; Recorrência; Sucesso final; e Complicações. A análise foi baseada em modelos de efeito randômico e fixo. Resultados: Cinco estudos de coorte retrospectivo foram selecionados, com um total de 465 pacientes. Todos os estudos tinham dados de ressecção primária completa disponível, mostrando uma diferença favorável ao tratamento cirúrgico (Diferença de riscos = -0,22; Intervalo de confiança de 95% = -0,41 a -0,04). Dados de Sucesso primário também foram identificados em todos os cinco estudos. A análise mostrou que a abordagem cirúrgica supera o tratamento endoscópico neste desfecho (DR = -0,13; IC 95% = -0,24 a -0,02). Dados de recorrência foram encontrados em todos os estudos (465 pacientes), com benefício para o tratamento cirúrgico (DR = 0,12; IC 95% = 0,01 a 0,22). Analisando o desfecho de Sucesso final, disponível em todos os estudos, não encontramos diferença entre as duas abordagens terapêuticas (DR = -0,06; IC 95% = -0,15 a 0,04). Três estudos (251 pacientes) apresentaram dados de complicação, e a análise não mostrou diferença entre os tratamentos endoscópico e cirúrgico (DR = -0,15; IC 95% = -0,53 a 0,23), sem a possibilidade de descartar o viés de seleção para este desfecho. Conclusões: Considerando os desfechos de ressecção primária completa, sucesso primário e recorrência na comparação do tratamento cirúrgico com o tratamento endoscópico para adenomas de papila, a abordagem cirúrgica tem resultados significativamente melhores. Com relação ao sucesso final, não houve diferença entre os dois tratamentos. No desfecho das taxas de complicação, esta revisão sistemática não permite uma conclusão confiável devido à presença de alta heterogeneidade e provável viés de publicação nesta comparação / Objectives: To address the outcomes of endoscopic resection compared to surgery in the treatment of ampullary adenomas. Methods: A systematic review and meta-analysis was performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Medline, Embase, Cochrane, Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS), Scopus and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases were scanned. Studies included patients with ampullary adenomas and comparison data considering endoscopic treatment and surgery for the following outcomes: Complete primary resection; Primary success; Reccurence; Final success; and Complications. The analysis were based on both random and fixed effects model. Results: Five retrospective cohort studies were selected, with 465 patients. All five studies had complete primary resection data available, showing a difference that favours surgical treatment (Risk Difference = -0.22, 95% Confidence Interval = -0.41 to -0.04). Primary success data were identified in all five studies too. Analysis showed that surgical approach overcome endoscopic treatment in this outcome (RD = -0.13, 95% CI = -0.24 to -0.02). Recurrence data was found in all studies (465 patients), with benefit for the surgical treatment (RD = 0.12, 95% CI = -0.01 to 0.22). Analyzing the final success outcome, available in all studies, we found no difference between the two therapeutic approaches (RD = -0.06, 95% CI = -0.15 to 0.04). Three studies (251 patients) presented complication data and analysis shown no difference between the approaches (RD = -0.15, 95% CI = -0.53 to 0.23), not discarding the possibility of presence of selection bias for this outcome. Conclusions: Considering complete primary resection, primary success and recurrence outcomes, surgical approach achieves significantly better results. Regarding the final success, there was no difference between the two treatments. Addressing complication data, this systematic review does not allow for a reliable conclusion due to the presence of high heterogeneity and likely publication bias in this comparison
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Caracterização do perfil epidemiológico do paciente com câncer de reto no Instituto do Câncer do Estado de São Paulo: determinação dos fatores associados ao tempo de internação hospitalar do paciente cirúrgico / Epidemiological characterization of the Rectal Cancer Patient at the \"Instituto do Câncer do Estado de São Paulo\": Determination in Surgical Patient of the Factors Associated with Length of Stay

Daiane da Silva Oliveira 15 May 2017 (has links)
INTRODUÇÃO: A despeito de todos os avanços no tratamento cirúrgico do câncer, ainda existem fatores complicadores para a adequada evolução no pós-operatório. Realizou-se estudo retrospectivo em uma população de pacientes submetidos a tratamento cirúrgico oncológico eletivo para o câncer retal, a fim de caracterizá-los epidemiologicamente e determinar quais variáveis estão associadas a maior morbimortalidade tais como aumento de permanência hospitalar, utilização de unidade de terapia intensiva, reoperações, óbito em 30 dias e custos hospitalares totais. MÉTODO: Foram selecionados todos os pacientes submetidos a cirurgias retais eletivas para o tratamento oncológico no período de 01 de outubro de 2008 a 31 de dezembro de 2012, resultando numa amostra de 405 pacientes de idade adulta e ambos os sexos. Realizou-se análise univariada para cada desfecho e análise multivariada através de regressão logística com ajustamento para as seguintes variáveis: sexo, idade, índice massa corpórea, estadiamento TNM, procedimento realizado, escore ASA, via de acesso, realização de QRT neoadjuvante, intervalo entre a neoadjuvância e a cirurgia e tempo cirúrgico, com validação interna através da técnica de bootstrap. RESULTADOS: Foram identificados como fatores de risco para aumento de permanência hospitalar a obesidade classe II e III (OR 15,44; IC95% 1,05 - 227,52; p = 0,05) e anestesia combinada - regional associada à geral (OR 5,38; IC95% 1,08 - 29,95; p = 0,04); amputação abdominoperineal foi fator de risco para reoperação em 30 dias (OR 4,54; IC95% 1,15 - 17,90; p = 0,03); amputação abdominoperineal (OR 5,38; IC95% 1,21 - 23,73; p = 0,03) e exenteração pélvica (OR 19,98; IC95% 0,99 - 401,32; p = 0,05) foram fatores de risco para utilização de UTI; idade acima de 79 anos (OR 13,99; IC95% 1,51 - 128,95; p = 0,02) foi fator de risco para complicação pós-operatória; idade acima de 79 anos (OR 0,07; IC95% 0,01 - 0,39; p = 0,01) foi fator de proteção para tempo cirúrgico elevado, obesidade classe II e III (OR 12,87; IC95% 1,54 - 107,67; p = 0,02) e via de acesso laparoscópica com transição para aberta (OR 8,7; IC95% 2,67 - 28,36; p < 0,001) foram fatores de risco para tempo cirúrgico elevado. CONCLUSÕES: Obesidade classe II e III e anestesia combinada são fatores de risco para tempo de permanência hospitalar prolongado para pacientes submetidos a cirurgia para tratamento de câncer retal. Outros estudos se fazem necessários para entender quais são os mecanismos que levam a anestesia combinada, eventualmente, a este aumento de permanência hospitalar / INTRODUCTION: Despite all the developments in the surgical treatment of cancer, there are still complicating factors for a correct postoperative evolution. There were conducted a retrospective study in a population of patients submitted to surgical rectal cancer treatment to characterize them epidemiologically and determine which variables are associated with increased morbimortality such as increased hospital length of stay, use of intensive care unit, reoperations, 30-day mortality and total hospital costs. METHOD: All patients submitted to colorectal surgery treatment for cancer during the period October 1st, 2008 to December 31th, 2012, resulting in a sample of 405 patients of both genders. Univariate analysis was conducted for each outcome and multivariate analysis through logistic regression with adjustment for the following variables: sex, age, body mass index, TNM stage, procedure performed, ASA score, laparoscopic or open surgery, neoadjuvant treatment, interval between the neoadjuvant therapy and the surgery, and operative time, with internal validation by the bootstrap technique. RESULTS: there were identified as risk factors for increased hospital stay, the obesity class II and III (OR 15.44; 95% CI 1.05-227.52; p = 0.05) and combined anesthesia - regional and general (OR 5.38; 95% CI 1.08-29.95; p = 0.04); abdominoperineal amputation was a risk factor for 30-day reoperation (OR 4.54; 1.15 95% CI-17.90; p = 0.03); abdominoperineal amputation (OR 5.38; 95% CI 1.21-23.73; p = 0.03) and pelvic exenteration (OR 19.98; 95% CI 0.99-401.32; p = 0.05) were risk factors for ICU use; age over 79 years (OR 13.99; CI 1.51-128.95; p = 0.02) was a risk factor for postoperative complication; age over 79 years (OR 0.07; CI 0.01-0.39; p = 0.01) was protective factor to prolonged operative time , obesity class II and III (OR 12.87; CI 1.54-107.67; p = 0.02) and laparoscopic approach with transition to open (OR 8.7; CI 2.67-28.36; p 0.001) were risk factors to prolonged operative time. CONCLUSIONS: Obese class II and III and combined anesthesia are risk factors for prolonged hospital stay for patients undergoing surgery for rectal cancer treatment. Further studies are needed to understand the mechanisms that lead combined anesthesia to increase hospital stay
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Estudo da variação das medidas ortodônticas e da função respiratória nasal por rinometria acústica e rinomanometria em pacientes submetidos à expansão palatina cirurgicamente assistida / Study of the orthodontic measures variation and the nasal respiratory function through acoustic rhinometry and rhinomanometry in patients who have undergone surgically assisted rapid maxillary expansion

Camila Eduarda Zambon 27 April 2010 (has links)
Introdução: A atresia transversa da maxila é a discrepância volumétrica existente entre a maxila e a mandíbula no plano transversal que, além de alterações dento-esqueléticas, gera mudanças craniofaciais importantes, como o estreitamento das cavidades nasais, a diminuição da permeabilidade nasal e a respiração bucal. A expansão palatina cirurgicamente assistida (EPCA) é a técnica cirúrgica indicada para a correção da atresia maxilar em pacientes adultos, com o crescimento ósseo finalizado. A rinometria acústica é uma técnica objetiva de estudo da respiração nasal, com a qual se avalia a geometria e o volume nasal. Já a rinomanometria trata-se de um método aerodinâmico que quantifica a pressão transnasal e a resistência ao fluxo aéreo. Objetivos: O objetivo deste estudo foi avaliar subjetiva e objetivamente a função respiratória nasal, em pacientes com atresia maxilar, submetidos à EPCA e determinar o tipo de correlação existente entre as medidas ortodônticas e as alterações de área, volume, resistência, e fluxo aéreo nasal. Casuística e Métodos: Para a realização do estudo foram avaliados 27 pacientes adultos, por meio da rinometria acústica, rinomanometria, medidas ortodônticas (perímetro e comprimento do arco maxilar, distância transversa entre caninos, prés-molares e molares superiores) em modelos de estudos e escala visual analógica da função respiratória apenas nasal, no pré-operatório, após a ativação do expansor maxilar do tipo Hyrax, instalado previamente à cirurgia, e após quatro meses da EPCA, realizada sob anestesia geral. Os exames otorrinolaringológicos foram realizados em sala ambientalizada, com e sem o uso de vasoconstritor nasal, em ambas as cavidades nasais. Resultados: Os resultados demonstraram que 59,3% da casuística era do gênero feminino, com idade média de 25,33 anos. Todas as medidas ortodônticas obtiveram um aumento estatisticamente significante (p<0,001), que mantiveram-se ao longo da tempo (p<0,001). Todas as medidas avaliadas apresentaram melhores resultados com o uso de vasoconstritor nasal. A área da cavidade nasal como um todo aumentou após a cirurgia (p<0,036). O volume médio é 2,75 maior com o uso de vasoconstritor (p < 0,001), porém não houve alterações estatisticamente significantes entre os momentos avaliados. Os fluxos expiratórios e inspiratórios aumentaram ao longo do tempo (p<0,001, para ambos). A pressão expiratória diminui no decorrer dos momentos avaliados (p<0,004). A análise subjetiva da sensação respiratória apenas pelo nariz aumentou significantemente de um momento para o outro (p<0,05). Houve correlação estatística entre perímetro do arco aumentado e resistência aérea diminuída (p=0,004) e entre o aumento de uma medida transversa com o aumento do fluxo inspiratório e expiratório, sem o uso de vasoconstritor (p=0,023 e p=0,004 respectivamente). Apenas o fluxo respiratório apresentou comportamento diferente entre os lados. Conclusões: Assim, conclui-se que o procedimento cirúrgico de EPCA promove alterações importantes nas cavidades oral e nasais que, associadas, geram melhor qualidade respiratória ao paciente e demonstram a relevância clínica otorrinolaringológica de tal procedimento cirúrgico bucomaxilofacial / Introduction: Transverse atresia of maxilla is a volumetric discrepancy existing between the maxilla and the mandible on the transversal plan that, besides dentoskeletal alterations, generates important craniofacial changes, such as nasal cavities constriction, diminution of nasal permeability and buccal breathing. The surgically assisted rapid maxillary expansion (SARME) is the surgical technique indicated for correcting maxillary atresia in adult patients, whose bone development was concluded. Acoustic rhinometry is a technique of nasal breathing, with which the nasal geometry and volume are assessed. As for rhinomanometry, it is an aerodynamic method that quantifies the transnasal pressure and resistance to aerial flow. Objectives: The purpose of this paper was evaluating subjectively and objectively the nasal respiratory function in patients with maxillary atresia, who have undergone SARME and determining the type of correlation existing between the orthodontic measures and the alterations of area, volume, resistance, and nasal aerial flow. Casuistic and Methods: For the paper accomplishment were assessed 27 adult patients, through acoustic rhinometry, rhinomanometry, orthodontic measures (perimeter and length of maxillary arch, transverse distance among canines, premolars and superior molars) in models of studies and analogical visual scale of only nasal respiratory function, on pre-surgical, after the activation of Hyrax-type maxillary expander, installed previously to the surgery, and after four months of SARME, accomplished under general anesthesia. The otorhinolaryngological tests were accomplished in an environmentally adapted room, with and without the use of nasal vasoconstrictor, in both nasal cavities. Results: The results have demonstrated that 59.3% of the casuistic was of female gender, with an average age of 25.33 years. All the orthodontic measures have obtained a statistically significant growth (p<0.001), which have maintained along the time (p<0.001). All the assessed measures have presented better results with the use of nasal vasoconstrictor. The nasal cavity area as a whole augmented after the surgery (p<0.036). The average volume is 2.75 larger with the vasoconstrictor use (p < 0.001), however, there was any statistically significant alterations between the moments assessed. The expiratory and inspiratory flows have grown along the time (p<0.001, for both). The expiratory pressure is reduced in the course of the moments assessed (p<0.004). The subjective analysis of respiratory sensation only through nose has increased significantly from one moment to the other (p<0.05). There was a statistic correlation between perimeter of augmented arch and aerial resistance diminished (p=0.004) and between the increase of a transverse measure with the growth of inspiratory and expiratory flow, with and without the use of vasoconstrictor (p=0.023 and p=0.004 respectively). Only the respiratory flow presented a different behavior between the sides. Conclusions: Thus, it is concluded that the SARME promotes important alterations on oral and nasal cavities that, associated, generate a better respiratory quality to the patient and demonstrate a clinical otorhinolaryngological relevance of such bucomaxillofacial surgical procedure

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