Background:The partial loss of the lacrimal gland by obstruction, injury, removal of tumor tissue or other pathological changes may lead to loss of tear flow, bringing harmful consequences to the body. The aim was to evaluate the production of tears after removal of approximately 50% of the main lacrimal gland. Materials, Methods & Results:For this, lacrimal glands from the left eyes of seven dogs, male, adult, with weight ranging from 6 to 13kg were partially removed. In each animal, an incision of approximately 3.0 cm of skin, orbicularis and cutaneous muscle of the eye between the eyeball and the zygomatic process of frontal bone of the lateral left side was performed. After incision of the conjunctiva, close to the zygomatic process, the orbital ligament was located and partially sectioned to expose the main lacrimal gland. With a stainless steel wire graph, the gland was measured and retired approximately 50% of the parenchyma. The fragment was placed in a bottle containing 10% formalin for histological evaluation. The tears production was measured with lacrimal Schirmer test at 28 ºC and 70% relative humidity 24 hours before surgery and on the 15th, 30th and 60th days after surgery. At the 60th day, samples of gland lacrimal of the same animals were colleted for histopathologic examination of number, mean diameter of the acini and their nuclei, nucleus: cytoplasm ratio and cell area in a sample of 30 acini per animal and the density of collagen fibers. In the evaluations of the tears production with the Schirmer Test, between the pre-operative (PE), 15, 30 and 60 days post-operatively (PO) were noticed significant differences (p=0.0033) at times between PE and 15 days of PO and between 15 and 60 days of PO. By comparing histological evaluation of lacrimal gland samples in the PE and after 60 days, there were significant differences in the lacrimal gland of nuclear area (p > 0), nuclear cytoplasm proportion (p=0.0006) and cell area (p=0.0083). The collagen fibers formation did not differ significantly between the PE and 60 days after partial removal of the gland (p=0.7104). All the ethical principles of ethical use of animals in experiments recommended by the Brazilian College of Animal Experimentation and Ethics Committee of the use of animals at the Federal University of Uberlandia. Discussion: The partial removal allowed the lacrimal gland remaining to offset the production of aqueous tear film: the values found in tear production were above normal throughout the trial period. Induction of cells secreting tears to hyperactivity occurred to offset the demand of production after removing part of the gland. Thus, it was stimulated increase nuclear -giant and multiple nuclei in constant transcription-protein synthesis -and small cytoplasm with little storage tear. This fact explains the increase in cell at 60 days, the decrease in tear production after 24 hours and its return to normal parameters at 60 days postoperatively. In this experiment, the density of collagen fibers found throughout the parenchyma tea...
Foram utilizados 18 coelhos, Nova Zelândia, machos, adultos, para avaliação clínica e histológica do reparo do ramo bucal dorsal do nervo facial, decorridos 15, 30 e 60 dias de pós-operatório (PO). Os animais foram distribuídos em dois grupos para secção e aproximação epineural do ramo bucal com fio náilon monofilamentoso 10-0. Nos animais do grupo I, o nervo foi revestido com proteção de segmento de jejuno alógeno conservado em glicerina a 98% e o grupo II apenas aplicação de sutura epineural. Nos coelhos dos dois grupos ocorreu retorno da movimentação do lábio superior a partir da oitava semana. Verificou-se infiltrados celulares e células gigantes com fibrose desorganizada e fibras colágenas do envoltório alógeno entremeadas ao tecido conjuntivo. Aos 15 e 30 dias de PO, os cotos distais de ambos os grupos encontravam-se com degeneração walleriana e aos 60 dias, com fibras regeneradas. A reparação do ramo bucal dorsal do nervo facial com o segmento intestinal não foi significativamente diferente nos coelhos do controle, quanto à avaliação de recuperação funcional e histológica.
SUMMARYFourteen healthy, adult New Zealand rabbits, males and females, were used to evaluate the histological and clinical aspects after the implant of Teflon tube associated to mytomicin C. The ten right eyes of group I and ten left eyes of group II were evaluated for 30 and 60 days of postoperative (PO), respectively. The other eight eyes of group III were observed for 48 hours. A bag was constituted in the bulbar conjunctive and inside of it mytomicin C was applied. A Teflon tube was introduced in the anterior chamber and fastened in the sclera, the conjunctive bag was approximated in the limbus over the implant. There was significant difference in the averages of the intraocular pressures (IOP) between the preoperative and the postoperative of 30 and 60 days. The animals of groups I and II presented hypotonia and shallow anterior chamber in the first 15 days of PO. In the histological evaluation of the conjunctive bag, descaling of the epithelium superficial cells and degeneration of the conjunctive tissue was verified, which indicated healing changes due to the action of mytomicin C. The implant of Teflon associated with mytomicin C demonstrated to be an effective method to decrease and to maintain the IOP from 30 to 60 days PO. KEY-WORDS:Antifibroblasts. Aqueous Humor. Glaucoma. Filtrative Surgery. Ophthalmology. Oryctolagus cuniculus. RESUMOForam utilizados 14 coelhos da raça Nova Zelândia, adultos, hígidos, machos e fêmeas, para avaliar os aspectos histológicos e clínicos após o implante de tubo de teflon associado a mitomicina C. Dez olhos direitos formaram o grupo I e dez olhos esquerdos formaram o grupo II avaliados por 30 e 60 dias de pós-operatório (PO), respectivamente. Os outros oito olhos formaram o grupo III observados por 48 horas. Foi constituído uma bolsa na conjuntiva bulbar e dentro dela foi aplicado mitomicina C. Um tubo de teflon foi introduzido na câmara anterior e fixado na esclera, a bolsa conjuntival foi aproximada no limbo sobre o implante. Houve diferença significativa nas médias das pressões intraoculares (PIO) entre o pré-operatório e o pós-operatório de 30 e 60 dias. Os animais dos grupos I e II apresentaram hipotonia e câmara anterior rasa nos primeiros 15 dias de PO. Na avaliação histológica da bolsa conjuntival foi verificado descamação das células superficiais do epitélio e degeneração do tecido conjuntivo, o que indicou alterações na cicatrização mediante ação da mitomicina C. O implante de teflon associado com mitomicina C demonstrou ser um método eficaz por diminuir e manter a PIO dos 30 aos 60 dias de PO.
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