Experimental autotransplant of spleen

Orientadores: Nelson Adami Andreollo, Norair Salviano dos ReisDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciencias MedicasResumo: O baço é um órgão linfóide que tem importante papel na defesa dos organismos, participando no processo de filtração, fagocitose e produção de imunoglobulinas. Histologicamente é formado pelo estroma e o parênquima, sendo seu arranjo celular diferenciado em polpas branca e vermelha. Os principais tipos celulares na estrutura esplênica são: linfócitos T e B, macrófagos, plasmócitos, fibrócitos, reticulócitos e células dendríticas. Os doentes vítimas de traumatismos esplênicos e esplenectomizados assumem um estado de asplenia e consequentemente adquirem grande susceptibilidade à sepse a qual pode ser rapidamente progressiva e fatal. Assim, têm surgido opções terapêuticas após as esplenectomias, utilizando técnicas cirúrgicas conservadoras (tratamento conservador, esplenectomia parcial e esplenorrafias com ou sem aplicação de agentes hemostáticos) e por fim as técnicas de autotransplante esplênico. Os objetivos desta pesquisa experimental foram analisar macro e microscopicamente a evolução tardia do autotransplante de fragmentos de baço na cavidade peritoneal, epíplon e mesentério, após 24 semanas de observação. Foram utilizados 52 ratos Wistar, machos e adultos, submetidos a esplenectomia total e divididos em quatro grupos. O grupo I (controle) foi formado por oito animais escolhidos aleatoriamente entre os três grupos estudados. O grupo II por dezessete animais com implante de fragmento de baço solto na cavidade peritoneal; grupo III por dezoito animais com implante no epíplon e o grupo IV por dezessete animais com implante fixado na raiz do mesentério. Na avaliação histológica foram adotados critérios qualitativos e quantitativos, com a contagem de elementos celulares e não celulares. Os resultados mostraram que se formaram aderências aos tecidos adjacentes e neovascularização em todos os fragmentos transplantados. O grupo II apresentou polpa branca e vascularização preservadas. No grupo III foram observados polpa branca com formações folicular e bainha linfóide, e a polpa vermelha em aspecto cordonal apesar de hemorrágica. No grupo IV foram observados alguns cortes histológicos com depleção de polpa branca e vermelha, enquanto outros evidenciavam melhor preservação das polpas. A contagem de linfócitos revelou diferença significativa entre os grupos I e II e o grupo I e IV (p0,05). Os outros elementos: macrófagos ativos fagocitando hemossiderina, plasmócitos, fibroblastos, fibrócitos, células gigantes, monócitos, espaços intersticiais e fibras de colágeno, não apresentaram diferença significativa entre os grupos. O autotransplante esplênico é factível, sendo o grande epíplon o melhor local para a sua fixação. Esta pesquisa demonstrou por meio de análise histológica qualitativa e quantitativa que o tecido esplênico autotransplantado no epíplon preserva sua função de defesa dos organismosAbstract: The spleen is a lymphoid organ that plays important part in the organism defense, participating in filtration processes, phagocytosis and immunoglobulin production. Histologically, is formed by a stroma and the parenquima being its cellular arrangement differentiated in white and red pulps. The main cellular types in the splenic structure are: T and B lymphocytes, macrophages, plasmocytes, fibrocytes, reticulocytes and dendritic cells. The patients victims of spleen traumatisms and splenectomized assume an asplenia state and consequently they acquire a larger susceptibility to the sepses, which can be quickly progressive and fatal. Thus, it has appeared therapeutic options after the splenectomies, using techniques of conservative surgery (conservative treatment, partial splenectomies and splenorrhaphies with or without application of haemostatics agents), as well as techniques of splenic autotransplantation. The objectives of the research were to evaluate macro and microscopically the late evolution of the fragments of spleen autotransplanted in the greater omentum, mesenterium and peritoneal cavity, after 24 weeks of observation. To perform the experimental study, were employed fifty two Wistar rats, males and adults, submitted to total splenectomy and divided in four groups. The group (control) I was formed by eight animals chosen aleatorily among the three groups studied. The group II - seventeen animals with implant of spleen fragment in the peritoneal cavity; group III - eighteen animals with implant in the omentum and group IV - seventeen animals with implant fixed in mesenterium root. In the histological analysis were adopted qualitative and quantitative criteria, with the counting of no cellular e cellular elements. The results showed adherences to the adjacent tissues and vascularization in all of the fragments transplanted. The group II presented white pulp and preserved vascularization. The group III showed white pulp with follicular formations and lymphoid tissue preserved, and the red pulp in cordon aspect and hemorrhagic. The group IV presented depletion of white and red pulp, while others evidenced better preservation of the pulps. The counting of lymphocytes revealed significant difference between the groups I and II and the group I and IV (p 0.05). The other elements: active macrophages phagocyting hemosiderine, plasmocytes, fibroblasts, fibrocytes, giant cells, monocytes, interstitial spaces and fibers of collagen, did not show significant difference among the groups. The splenic autransplantation is feasible, being the better place the greater omentum. This research demonstrated through qualitative and quantitative histological analysis that the splenic tissue autotransplanted in the omentum of Wistar rats preserves its function of defense of the organismsMestradoPesquisa ExperimentalMestre em Cirurgi

Subconjunctival use of allogeneic mesenchymal stem cells to treat chronic superficial keratitis in German shepherd dogs: Pilot study

Background: Chronic superficial keratitis (CSK) is an ocular condition in dogs characterized by corneal opacification leading to visual function impairment. Control of this chronic condition requires the use of topical immunomodulators or corticosteroids daily. Regenerative medicine has shown promising results in several fields of medicine. Aim: The aim of this study was to evaluate the clinical effect of allogeneic mesenchymal stem cells (MSCs) of adipose tissue applied via subconjunctival in dogs with CSK. Methods: A series of cases of eight dogs diagnosed with CSK were divided into two groups, four dogs each; the conventional treatment group received prednisolone 1% as topical eye drops and the experimental group (EG) received allogeneic MSCs transplantation. The dogs had not previously been treated for CSK. Systemic and ophthalmologic examinations were performed to exclude other abnormalities. An administered amount of MSC (1 × 106 cells each time) was injected via subconjunctival in the peri-limbal region at 0 and 30 days. The animals were followed for 110 days for clinical evaluation, and, at the same time, the images of the corneal abnormalities were obtained and analyzed in the ImageJ software. The statistical analysis was performed in the GrandPrism 7.0 software. Results: Initial and final images revealed that areas with neovascularization, inflammatory infiltrate, and opacity regressed in most eyes in both groups (7/8 eyes in each group) at the end of the 110 days, p = 0.0391 and p = 0.0078 respectively, but this response was minor in the EG comparing to conventional group (CG) (p = 0.026). No local or systemic side effects were observed. Conclusions: Despite the small melioration, MSCs treatment suggests clinical improvement in patients with CSK after 110 days without any local or systemic side effects. However, the improvement achieved was significantly less than the observed within CG. Further studies still are needed to evaluate the use and benefits of stem cells as an adjunct treatment for CSK