Comprehensive analysis of epigenetic clocks reveals associations between disproportionate biological ageing and hippocampal volume

The concept of age acceleration, the difference between biological age and chronological age, is of growing interest, particularly with respect to age-related disorders, such as Alzheimer’s Disease (AD). Whilst studies have reported associations with AD risk and related phenotypes, there remains a lack of consensus on these associations. Here we aimed to comprehensively investigate the relationship between five recognised measures of age acceleration, based on DNA methylation patterns (DNAm age), and cross-sectional and longitudinal cognition and AD-related neuroimaging phenotypes (volumetric MRI and Amyloid-β PET) in the Australian Imaging, Biomarkers and Lifestyle (AIBL) and the Alzheimer’s Disease Neuroimaging Initiative (ADNI). Significant associations were observed between age acceleration using the Hannum epigenetic clock and cross-sectional hippocampal volume in AIBL and replicated in ADNI. In AIBL, several other findings were observed cross-sectionally, including a significant association between hippocampal volume and the Hannum and Phenoage epigenetic clocks. Further, significant associations were also observed between hippocampal volume and the Zhang and Phenoage epigenetic clocks within Amyloid-β positive individuals. However, these were not validated within the ADNI cohort. No associations between age acceleration and other Alzheimer’s disease-related phenotypes, including measures of cognition or brain Amyloid-β burden, were observed, and there was no association with longitudinal change in any phenotype. This study presents a link between age acceleration, as determined using DNA methylation, and hippocampal volume that was statistically significant across two highly characterised cohorts. The results presented in this study contribute to a growing literature that supports the role of epigenetic modifications in ageing and AD-related phenotypes

Long-term dental anomalies after pediatric cancer treatment in children [Kanser tedavisi gören çocuklarda uzun süre sonra görülen diş anomalileri]

PubMed ID: 30322830Objective: The aim of this study is to determine the frequency of dental anomalies (DAs) (microdontia, hypodontia, hyperdontia, enamel defect, root malformation) in pediatric cancer patients at the ages <5 years and between 5 and 7 years, and understand their relationship with the received therapy. Materials and Methods: Pediatric patients who were diagnosed with cancer and treated before the age of 7 years were investigated in a case-control design. The study included 93 pediatric patients whose ages at diagnosis were between 9 months and 7 years and whose treatments were completed before 5-8 years. Group A consisted of patients in the age range of 9 months to 4 years and Group B consisted of patients in the age range of 5-7 years. Seventy-two siblings with compatible dental age ranges were included in the control group. For both groups, intraoral examinations were performed and panoramic radiographs were taken. Results: Among the 93 pediatric patients, the mean age was 9.54±1.25 (range: 8-13 years) and 48 (51.6%) patients were male. The most common diagnosis was hematologic malignancy with a rate of 65.5%. At least one DA was detected in 7 (9.7%) individuals of the control group and in 78 (83.9%) of the patient group. While the patients in the study group had all kinds of DAs, those in the control group had only enamel defects. The rates of microdontia (p=0.077) and hypodontia (p=0.058) were detected to be significantly higher in Group A than in Group B. Root malformation was more common in patients receiving chemotherapy and radiotherapy than in those receiving only chemotherapy (p=0.006). Conclusion: In this study it was found that the pediatric patients who received cancer treatment before the age of 7 years constituted a high-risk group for DAs. The frequencies of microdontia and hypodontia were increased even more when the patient was treated for cancer before 5 years of age. © 2019 by Turkish Society of Hematology

Growing knowledge: an overview of Seed Plant diversity in Brazil

Abstract An updated inventory of Brazilian seed plants is presented and offers important insights into the country's biodiversity. This work started in 2010, with the publication of the Plants and Fungi Catalogue, and has been updated since by more than 430 specialists working online. Brazil is home to 32,086 native Angiosperms and 23 native Gymnosperms, showing an increase of 3% in its species richness in relation to 2010. The Amazon Rainforest is the richest Brazilian biome for Gymnosperms, while the Atlantic Rainforest is the richest one for Angiosperms. There was a considerable increment in the number of species and endemism rates for biomes, except for the Amazon that showed a decrease of 2.5% of recorded endemics. However, well over half of Brazillian seed plant species (57.4%) is endemic to this territory. The proportion of life-forms varies among different biomes: trees are more expressive in the Amazon and Atlantic Rainforest biomes while herbs predominate in the Pampa, and lianas are more expressive in the Amazon, Atlantic Rainforest, and Pantanal. This compilation serves not only to quantify Brazilian biodiversity, but also to highlight areas where there information is lacking and to provide a framework for the challenge faced in conserving Brazil's unique and diverse flora