Genetic Characterization of Indubrasil Cattle Breed Population.

The Indubrasil breed was developed in the Brazilian region called Triângulo Mineiro as a result of a cross between zebu cattle. Initially, it was used as a terminal cross and currently it represents approximately 4.45% of all the Brazilian zebu cattle. Studies were conducted to estimate genetic parameters in the Indubrasil using pedigree information, however, until now, no study has been developed using large-scale genomic markers in this breed. Pedigree information are widely used to investigate population parameters; however, they can neglect some estimates when compared to the use of genomic markers. Therefore, the objective of this study was to investigate the population structure and the genetic diversity of Indubrasil cattle using a high-density Single Nucleotide Polymorphism (SNP) panel (Illumina BovineHD BeadChip 700k). Levels of genomic homozygosity were evaluated using three different approaches: Runs of homozygosity (FROH), % of homozygosis (FSNP), and inbreeding coefficient (Fx). Further, Runs of Homozygosity (ROH) segments conserved among the animals were investigated to identify possible regions associated with the breed characteristics. Our results indicate that even the Indubrasil breed having a small effective population size, the levels of homozygosity (FROH = 0.046) are still small. This was possibly caused by the cross conducted among different breeds for its development. It suggests no immediate risks associated with loss of genetic variation. This information might be used in breeding programs, for the breed conservation and for the expansion of the Indubrasil breed.

The UK Neovascular AMD Database Report 3: inter-centre variation in visual acuity outcomes and establishing real-world measures of care.

PurposeInternational variations in visual acuity (VA) outcomes of eyes treated for neovascular age-related macular degeneration (nAMD) are well-documented, but intra-country inter-centre regional variations are not known. These data are important for national quality outcome indicators. We aimed to determine intra-country and inter-centre regional variations in outcomes for treatment of nAMD.Patients and methodsProspective multicentre national database study of 13 UK centres that treated patients according to a set protocol (three loading doses, followed by Pro-Re-Nata retreatment). A total of 5811 treatment naive eyes of 5205 patients received a total of 36 206 ranibizumab injections over 12 months.ResultsMean starting VA between centres varied from 48.9 to 59.9 ETDRS letters. Mean inter-centre VA change from baseline to 12 months varied from +6.9 letters to -0.6 letters (mean of +2.5 letters). The proportion of eyes achieving VA of 70 letters or more varied between 21.9 and 48.7% at 12 months. Median number of injections (visits) at each centre varied from 5 to 8 (9 to 12), with an overall median of 6 (11). Age, starting VA, number of injections, and visits, but not gender were significantly associated with variation in these VA outcomes (P<0.01). Significant variation between centres persisted even after adjusting for these factors.ConclusionThere are modest differences in VA outcomes between centres in the UK. These differences are influenced, but not completely explained, by factors such as patient age, starting VA, number of injections, and visits. These data provide an indication of the VA outcomes that are achievable in real-world settings.

Visual complications of proton beam therapy for clival chordoma.

PURPOSE: Combining maximal surgical resection with high-dose proton radiation therapy is reported to be currently the best management of patients with clival chordoma. METHOD: Since 1991, four consecutive patients from our institution with this tumour have been referred for postoperative proton beam radiotherapy. RESULT: We have experienced an unusually high complication rate (50%) of delayed radiation optic neuropathy. This has resulted in profound, bilateral visual loss at 1 and 2 years postproton beam treatment. CONCLUSION: It has served as a reminder that proton beam therapy is not an innocuous treatment option and this devastating complication should be taken into account when discussing the management of clivus chordoma. We postulate whether the optic apparatus is particularly sensitive to proton vs photon damage.