RESUMEN

Background: The black-tufted ear marmoset, Callithrix penicillata, is an endemic primate from Brazil, distributed among Cerrado and Atlantic Forest vegetation. Most of the congenital malformations from the spinal cord arises from failures in the neural tube closure. Those failures result in an opened dorsal arch of one or more vertebrae are referred as spina bifida. In the occulta form, the condition is asymptomatic because spinal cord and meninges remain in the normal position. When the meninges become distended with fluid (myelomeningocele), the phenomenon is called spina bifida cystica. In these cases, the spinal cord protrudes into the subarachnoid space and the nerve roots may become displaced, causing neurological defi cits. When this defect allows leakage of cerebrospinal fluid through the skin, it is characterized as the open form. This article reports the findings of the first case of spina bifida occulta in an adult male of Callithrix penicillata collected dead in a brazilian highway. Case: A cadaver of a young-adult, male, black-tufted ear marmoset (Callithrix penicillata) was founded at km 103 of BR-116 highway in the city of Guapimirim, Rio de Janeiro State, Brazil. The cadaver was necropsied at the Laboratory of Animal Anatomy from Universidade Castelo Branco, in the city of Rio de Janeiro, Brazil. During macroscopic evaluation it was possible to identify a normal body score, healthy skin, and the presence of multiple fractures in the skull. Encephalic injury was indicated as the cause of his death. After the necropsy, the body was subjected to maceration technique to prepare his skeleton to the museum of the laboratory. Once soft tissues were removed, the skeleton was placed in the plastic box that contained a colony of necrophagous beetles (Dermestes maculatus), which completed the process of cleaning the bones. At this time, a failure to close the vertebral arches of T2, T3 and T4 was observed which characterized a case of spina bifida oculta. Discussion: As long as spina bifida is one of the most common malformations in humans, it has also been reported in several species of animals. Besides being one of the most common malformations in humans, spina bifida has been reported in several species of animals. However, there is only one report of spina bifida (cystic) of spontaneous occurrence in primates (in a female of Macaca niger with neurological defi cits). According to current literature, this is the first report of spina bifida in Callithrix penicillata, as well as in a wild animal in Brazil. Spina bifida affects most commonly lumbar or sacral vertebrae. In this case, although, malformation occurred at the level of thoracic vertebrae T2, T3 and T4, an uncommon location. The fact that the cause of death of the marmosets have been a traumatic brain injury, coupled with the appearance of changes of the vertebral arches, absence of deformation in the skin and the apparent good body condition, allowed us to deduce that this was a case of spina bifida occulta. It would be unlikely that a wild animal with myelomeningocele could survive until adulthood. The possibility of a coexisting meningocele could be compatible with the survival, despite some degree of motor impairment would make it proned to be hit by cars, falls or predation. It was not possible to determine the cause of malformation in this case, but one can imagine that some factors deficiencies (eg.: folic acid or zinc), genetic factors and effects of teratogenic substances from the environment would be some of the speculated causes for the appearance of spina bifida in this marmoset. Information about congenital malformations from other animals in the same geographic region could eventually reinforce this hypothesis.

Asunto(s)

RESUMEN

PURPOSE: Evaluate the anesthetic management in intrauterine surgery to induce myelomeningocele in non human primates Macaca mulatta. METHODS: A total of nine fetuses had intrauterine surgery; laminectomy was performed on them in L5 and L6. The studied variables were: maternal death, fetus death, cardiac frequency, respiratory frequency, arterial pressure, temperature, and oxygen saturation. RESULTS: No maternal or fetal deaths occurred; the only variable that was reported below the normal ranges was temperature. CONCLUSION: No maternal or fetal deaths occurred; the only variable that was reported below the normal ranges was temperature.(AU)

OBJETIVO: Avaliar o manejo anestésico em cirurgia intra-uterina para induzir mielomeningocelo em primatas não humanos, Macaca mulatta. MÉTODOS: Operaram-se um total de nove fetos in útero que foram submetidos à laminectomia em L5 e L6. As variáveis a estudar foram mortes maternas ou fetais, freqüência cardíaca e respiratória, pressão arterial, temperatura e saturação de oxigênio. RESULTADOS: Não se apresentaram mortes maternas ou fetais, a temperatura se manteve abaixo dos 36ºC, não tendo repercussões no bem-estar dos macacos. CONCLUSÃO: Não ocorreu nenhum óbito materno ou fetal, sendo que a única variável abaixo do normal foi a temperatura.(AU)

Asunto(s)

RESUMEN

PURPOSE: To produce a myelomeningocele-like human defect in the ovine fetus and validate this experimental model in our population. METHODS: A prospective study on 12 pregnant sheep of a crossed Hampshire/Down breed where a spinal defect was surgically created between Day 75 and Day 77 after conception. The technique consisted of a hysterotomy with exposure of fetal hind limbs and tail up to the mid spine. Fetal skin, paravertebral muscles, and 4 posterior spinal arches were excised, exposing the spinal cord. Duramater was opened and the medulla was incised until the medullar canal. Animals were euthanized at 139 days of gestation for fetal evaluation. The central nervous system was submitted to post-mortem magnetic resonance imaging (MRI) and the spine was submitted to pathological examination. RESULTS: The defect was created in 13 fetuses and 5 survived. Mean gestational age at necropsy was 121.6 days (varying from 93 to 145 days). Macroscopically, the defect was present in 4 cases. Microscopy revealed a flattened medulla with disappearance of the medullar canal and disruption of normal medullar architecture with neuronal apoptosis and/or fusion of the piamater and duramater. The MRI showed herniation of the cerebellum into the cervical canal and syringomyelia. CONCLUSIONS: The surgically produced defect mimics the defect found in the human fetus, including the Arnold-Chiari malformation. Post-mortem MRI was used for the first time in our study and proved an excellent alternative for demonstrating the cerebellar herniation. We standardized the technique for creating the defect in our population.(AU)

OBJETIVO: Produzir um defeito semelhante a meningomielocele humana em feto de ovinos, validando este modelo experimental, em nosso meio. MÉTODOS: Estudo prospectivo com 12 ovelhas de cruzamento das raças Hampshire e Down, onde um defeito na coluna foi criado cirurgicamente com 75 a 77 dias de gestação. A técnica consistiu em histerotomia com exposição das patas traseiras e cauda até a metade da coluna fetal. Foram retirados pele, musculatura paravertebral e 4 arcos vertebrais posteriores, expondo a medula. A dura foi aberta e uma incisão até o canal medular foi realizada. O sacrifício foi realizado com 139 dias de gestação para avaliação fetal. O sistema nervoso central foi submetido a ressonância magnética (REMA) post-mortem e a coluna foi submetida a exame anátomo-patológico. RESULTADOS: O defeito foi criado em 13 fetos e 5 sobreviveram. A idade gestacional média da necropsia foi de 121,6 dias (variando de 93 a 145 dias). Macroscopicamente o defeito estava presente em 4 casos. A microscopia revelou achatamento da medula, com desaparecimento do canal medular e desarranjo da citoarquitetura medular com apoptose neuronal e/ou fusão da pia e dura-máter. A REMA demonstrou herniação do cerebelo para o canal cervical e siringomelia. CONCLUSÕES: O defeito produzido foi muito semelhante à meningomielocele em fetos humanos, levando inclusive à mal-formação de Arnold-Chiari. A REMA post-mortem, utilizada de forma inédita neste estudo, demonstrou ser uma excelente alternativa para demonstrar a presença da herniação do cerebelo. A técnica para produzir o defeito foi padronizada em nosso meio.(AU)

Asunto(s)