ABSTRACT
ABSTRACT A 71-year-old woman presented a non-arteritic anterior ischemic optic neuropathy in an optic nerve with previously registered superonasal peripapillary myelinated nerve fibers. Her past medical history was significant for controlled systemic hypertension, hyperlipidemia, and diabetes mellitus. The physiologic cup was absent in both optic discs. Non-arteritic anterior ischemic optic neuropathy mainly affected the temporal and inferior sectors of the peripapillary retinal nerve fiber layer, as could be demonstrated by retinal nerve fiber layer optical coherence tomography and optic disc optical coherence tomography angiography. Unlike other published reports, just a slight regression of the myelinated nerve fibers was observed after 1 year of follow-up. This occurred because ischemia mainly affected the temporal and inferior peripapillary sectors, whereas myelinated nerve fibers were superonasal to the optic disc.
RESUMO Uma mulher de 71 anos de idade apresentou neuropatia óptica isquêmica anterior não arterítica no nervo óptico com fibras nervosas peripapilares mielinizadas previamente registradas. Seu histórico médico foi significativo para hipertensão arterial sistêmica controlada, hiperlipidemia e diabetes mellitus. Em ambos os discos ópticos, a tacícula fisiológica esteve ausente. A neuropatia óptica isquêmica anterior não arterítica afetou principalmente os setores temporal e inferior da camada de fibras nervosas da retina peripapilar, como demonstrado pela tomografia de coerência óptica da camada de fibras nervosas da retina e pela angiotomografia de coerência óptica do disco óptico. Ao contrário de outros relatórios publicados, apenas uma ligeira regressão das fibras nervosas mielinizadas foi observada após um ano de acompanhamento. Isto pode ser explicado pelo fato da isquemia ter afetado principalmente os setores temporal e inferior peripapilares, enquanto as fibras nervosas de mielina eram nasal superior ao disco óptico.
ABSTRACT
Background & objectives: Insulin regulated aminopeptidase (IRAP) has been related to certain pathologies such as breast cancer, Alzheimer´s disease and septic shock. IRAP is encoded by the leucyl/cystinyl aminopeptidase (LNPEP) gene. The genetic variation in the LNPEP gene has been analyzed in relation with the mortality and vasopressin clearance in septic shock. The LNPEP rs4869317 SNP (single nucleotide polymorphism) was the most significantly associated SNP with vasopressinase activity, being TT genotype associated with increased mortality. The objective of the present study was to develop a simple method to allow a quick and affordable genotyping for the rs4869317 SNP of LNPEP gene. Methods: Blood DNA samples were obtained from randomly selected healthy volunteers (n=28). A pair of primers was designed to amplify an 834 bp region of the LNPEP gene containing the rs4869317 SNP. The two alleles (T or A) were detected by digestion of the PCR products with the PacI restriction endonuclease. This enzyme only cuts the PCR products when the adenine is present in the SNP. Results: All individuals showed RFPL (restriction fragment length polymorphism) fragments for the expected genotypes (TT, TA or AA). The methodology was validated by sequencing of the amplified DNAs from several ‘T/T’ and ‘A/A’ homozygotes and ‘T/A’ heterozygotes. The results from both methods showed agreement. Interpretation & conclusions: The PCR-RFLP is a simple and reliable method that allows a quick genotyping for the rs4869317 SNP of LNPEP gene. The study of this polymorphism could be useful in future investigations to analyze the role of genetic variants of IRAP in several physiological/pathological conditions.