JEANNE DA ROSA OITICICA RAMALHO
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina
LIM/32 - Laboratório de Otorrinolaringologia, Hospital das Clínicas, Faculdade de Medicina
LIM/32 - Laboratório de Otorrinolaringologia, Hospital das Clínicas, Faculdade de Medicina
2 resultados
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- Genomic copy number alterations in non-syndromic hearing loss(2016) ROSENBERG, C.; FREITAS, E. L.; UEHARA, D. T.; AURICCHIO, M. T. B. M.; COSTA, S. S.; OITICICA, J.; SILVA, A. G.; KREPISCHI, A. C.; MINGRONI-NETTO, R. C.Genetic heterogeneity has made the identification of genes related to hearing impairment a challenge. In the absence of a clear phenotypic aetiology, recurrence risk estimates are often based on family segregation and may be imprecise. We profiled by oligonucleotide array-CGH patients presenting non-syndromic hearing loss with presumptive autosomal recessive (n=50) or autosomal dominant (n=50) patterns of inheritance. Rare copy number variants (CNVs) were detected in 12 probands; four of the detected CNVs comprised genes previously associated with hearing loss (POU4F3, EYA4, USH2A, and BCAP31) and were considered causative, stressing the contribution of genomic imbalance to non-syndromic deafness. In six cases, segregation of the CNVs in pedigrees excluded them as causative. In one case, segregation could not be investigated, while in another case, a point mutation likely explains the phenotype. These findings show that the presumptive patterns of inheritance were incorrect in at least two cases, thereby impacting genetic counselling. In addition, we report the first duplication reciprocal to the rare ABCD1, BCAP31, and SLC6A8 contiguous deletion syndrome; as with most microduplication syndromes, the associated phenotype is much milder than the respective microdeletion and, in this case, was restricted to hearing impairment.
- Transplantation and survival of mouse inner ear progenitor/stem cells in the organ of Corti after cochleostomy of hearing-impaired guinea pigs: preliminary results(2016) BARBOZA JR., L. C. M.; LEZIROVITZ, K.; ZANATTA, D. B.; STRAUSS, B. E.; MINGRONI-NETTO, R. C.; OITICICA, J.; HADDAD, L. A.; BENTO, R. F.In mammals, damage to sensory receptor cells (hair cells) of the inner ear results in permanent sensorineural hearing loss. Here, we investigated whether postnatal mouse inner ear progenitor/stem cells (mIESCs) are viable after transplantation into the basal turns of neomycin-injured guinea pig cochleas. We also examined the effects of mIESC transplantation on auditory functions. Eight adult female Cavia porcellus guinea pigs (250-350g) were deafened by intratympanic neomycin delivery. After 7 days, the animals were randomly divided in two groups. The study group (n = 4) received transplantation of LacZ-positive mIESCs in culture medium into the scala tympani. The control group (n = 4) received culture medium only. At 2 weeks after transplantation, functional analyses were performed by auditory brainstem response measurement, and the animals were sacrificed. The presence of mIESCs was evaluated by immunohistochemistry of sections of the cochlea from the study group. Non-parametric tests were used for statistical analysis of the data. Intratympanic neomycin delivery damaged hair cells and increased auditory thresholds prior to cell transplantation. There were no significant differences between auditory brainstem thresholds before and after transplantation in individual guinea pigs. Some mIESCs were observed in all scalae of the basal turns of the injured cochleas, and a proportion of these cells expressed the hair cell marker myosin VIIa. Some transplanted mIESCs engrafted in the cochlear basilar membrane. Our study demonstrates that transplanted cells survived and engrafted in the organ of Corti after cochleostomy.