PUBLICATIONS

2018

Abelson, Sagi, Grace Collord, Stanley W K Ng, Omer Weissbrod, Netta Mendelson Cohen, Elisabeth Niemeyer, Noam Barda, et al. (2018) 2018. “Prediction of Acute Myeloid Leukaemia Risk in Healthy Individuals.”. Nature 559 (7714): 400-404. https://doi.org/10.1038/s41586-018-0317-6.

The incidence of acute myeloid leukaemia (AML) increases with age and mortality exceeds 90% when diagnosed after age 65. Most cases arise without any detectable early symptoms and patients usually present with the acute complications of bone marrow failure1. The onset of such de novo AML cases is typically preceded by the accumulation of somatic mutations in preleukaemic haematopoietic stem and progenitor cells (HSPCs) that undergo clonal expansion2,3. However, recurrent AML mutations also accumulate in HSPCs during ageing of healthy individuals who do not develop AML, a phenomenon referred to as age-related clonal haematopoiesis (ARCH)4-8. Here we use deep sequencing to analyse genes that are recurrently mutated in AML to distinguish between individuals who have a high risk of developing AML and those with benign ARCH. We analysed peripheral blood cells from 95 individuals that were obtained on average 6.3 years before AML diagnosis (pre-AML group), together with 414 unselected age- and gender-matched individuals (control group). Pre-AML cases were distinct from controls and had more mutations per sample, higher variant allele frequencies, indicating greater clonal expansion, and showed enrichment of mutations in specific genes. Genetic parameters were used to derive a model that accurately predicted AML-free survival; this model was validated in an independent cohort of 29 pre-AML cases and 262 controls. Because AML is rare, we also developed an AML predictive model using a large electronic health record database that identified individuals at greater risk. Collectively our findings provide proof-of-concept that it is possible to discriminate ARCH from pre-AML many years before malignant transformation. This could in future enable earlier detection and monitoring, and may help to inform intervention.

2017

Dagan, Noa, Chandra Cohen-Stavi, Maya Leventer-Roberts, and Ran D Balicer. (2017) 2017. “External Validation and Comparison of Three Prediction Tools for Risk of Osteoporotic Fractures Using Data from Population Based Electronic Health Records: Retrospective Cohort Study.”. BMJ (Clinical Research Ed.) 356: i6755. https://doi.org/10.1136/bmj.i6755.

OBJECTIVE:  To directly compare the performance and externally validate the three most studied prediction tools for osteoporotic fractures-QFracture, FRAX, and Garvan-using data from electronic health records.

DESIGN:  Retrospective cohort study.

SETTING:  Payer provider healthcare organisation in Israel.

PARTICIPANTS:  1 054 815 members aged 50 to 90 years for comparison between tools and cohorts of different age ranges, corresponding to those in each tools' development study, for tool specific external validation.

MAIN OUTCOME MEASURE:  First diagnosis of a major osteoporotic fracture (for QFracture and FRAX tools) and hip fractures (for all three tools) recorded in electronic health records from 2010 to 2014. Observed fracture rates were compared to probabilities predicted retrospectively as of 2010.

RESULTS:  The observed five year hip fracture rate was 2.7% and the rate for major osteoporotic fractures was 7.7%. The areas under the receiver operating curve (AUC) for hip fracture prediction were 82.7% for QFracture, 81.5% for FRAX, and 77.8% for Garvan. For major osteoporotic fractures, AUCs were 71.2% for QFracture and 71.4% for FRAX. All the tools underestimated the fracture risk, but the average observed to predicted ratios and the calibration slopes of FRAX were closest to 1. Tool specific validation analyses yielded hip fracture prediction AUCs of 88.0% for QFracture (among those aged 30-100 years), 81.5% for FRAX (50-90 years), and 71.2% for Garvan (60-95 years).

CONCLUSIONS:  Both QFracture and FRAX had high discriminatory power for hip fracture prediction, with QFracture performing slightly better. This performance gap was more pronounced in previous studies, likely because of broader age inclusion criteria for QFracture validations. The simpler FRAX performed almost as well as QFracture for hip fracture prediction, and may have advantages if some of the input data required for QFracture are not available. However, both tools require calibration before implementation.

2015

Dagan, Noa, Daniel Beskin, Mayer Brezis, and Ben Y Reis. (2015) 2015. “Effects of Social Network Exposure on Nutritional Learning: Development of an Online Educational Platform.”. JMIR Serious Games 3 (2): e7. https://doi.org/10.2196/games.4002.

BACKGROUND: Social networking sites (SNSs) such as Facebook have the potential to enhance online public health interventions, in part, as they provide social exposure and reinforcement.

OBJECTIVE: The objective of the study was to evaluate whether social exposure provided by SNSs enhances the effects of online public health interventions.

METHODS: As a sample intervention, we developed Food Hero, an online platform for nutritional education in which players feed a virtual character according to their own nutritional needs and complete a set of virtual sport challenges. The platform was developed in 2 versions: a "private version" in which a user can see only his or her own score, and a "social version" in which a user can see other players' scores, including preexisting Facebook friends. We assessed changes in participants' nutritional knowledge using 4 quiz scores and 3 menu-assembly scores. Monitoring feeding and exercising attempts assessed engagement with the platform.

RESULTS: The 2 versions of the platform were randomly assigned between a study group (30 members receiving the social version) and a control group (33 members, private version). The study group's performance on the quizzes gradually increased over time, relative to that of the control group, becoming significantly higher by the fourth quiz (P=.02). Furthermore, the study group's menu-assembly scores improved over time compared to the first score, whereas the control group's performance deteriorated. Study group members spent an average of 3:40 minutes assembling each menu compared to 2:50 minutes in the control group, and performed an average of 1.58 daily sport challenges, compared to 1.21 in the control group (P=.03).

CONCLUSIONS: This work focused on isolating the SNSs' social effects in order to help guide future online interventions. Our results indicate that the social exposure provided by SNSs is associated with increased engagement and learning in an online nutritional educational platform.

2014

Rachmin, Inbal, Sagi Tshori, Yoav Smith, Amit Oppenheim, Sylvie Marchetto, Gillian Kay, Roger S-Y Foo, et al. (2014) 2014. “Erbin Is a Negative Modulator of Cardiac Hypertrophy.”. Proceedings of the National Academy of Sciences of the United States of America 111 (16): 5902-7. https://doi.org/10.1073/pnas.1320350111.

ErbB2 interacting protein (Erbin) is a widely expressed protein and participates in inhibition of several intracellular signaling pathways. Its mRNA has been found to be present in relatively high levels in the heart. However, its physiological role in the heart has not been explored. In the present work, we elucidated the role of Erbin in cardiac hypertrophy. Cardiac hypertrophy was induced in mice either by isoproterenol administration or by aortic constriction. The level of Erbin was significantly decreased in both models. Erbin(-/-) mice rapidly develop decompensated cardiac hypertrophy, and following severe pressure overload all Erbin(-/-) mice died from heart failure. Down-regulation of Erbin expression was also observed in biopsies derived from human failing hearts. It is known that Erbin inhibits Ras-mediated activation of the extracellular signal-regulated kinase (ERK) by binding to Soc-2 suppressor of clear homolog (Shoc2). Our data clearly show that ERK phosphorylation is enhanced in the heart tissues of Erbin(-/-) mice. Furthermore, we clearly demonstrate here that Erbin associates with Shoc2 in both whole hearts and in cardiomyocytes, and that in the absence of Erbin, Raf is phosphorylated and binds Shoc2, resulting in ERK phosphorylation. In conclusion, Erbin is an inhibitor of pathological cardiac hypertrophy, and this inhibition is mediated, at least in part, by modulating ERK signaling.

Del Mónaco, S M, N B Barda, N C Rubio, and A C Caballero. (2014) 2014. “Selection and Characterization of a Patagonian Pichia Kudriavzevii for Wine Deacidification.”. Journal of Applied Microbiology 117 (2): 451-64. https://doi.org/10.1111/jam.12547.

AIMS: The purpose of this study was to select autochthonous yeasts with metabolic ability to degrade L-malic acid for its potential use in young wine deacidification.

METHODS AND RESULTS: Fifty seven Patagonian nonSaccharomyces yeast of oenological origin were identified by conventional molecular methods and tested in their capability to grow at the expense of L-malic acid. Only four isolates belonging to Pichia kudriavzevii species showed this property, and one of them was selected to continue with the study. This isolate, named as P. kudriavzevii ÑNI15, was able to degrade L-malic acid in microvinifications, increasing the pH 0·2-0·3 units with a minimal effect on the acid structure of wine. Additionally, this isolate produced low levels of ethanol, important levels of glycerol (10·41 ± 0·48 g l(-1) ) and acceptable amounts of acetic acid (0·86 ± 0·13 g l(-1) ). In addition, it improved the sensorial attributes of wine increasing its fruity aroma.

CONCLUSIONS: The selection of yeasts for oenological use among nonSaccharomyces species led to the finding of a yeast strain with novel and interesting oenological characteristics which could have significant implications in the production of well-balanced and more physicochemical and microbiological stable young wines.

SIGNIFICANCE AND IMPACT OF THE STUDY: The use of P. kudriavzevii ÑNI15 as mixed starter with S. cerevisiae would eliminate the cultural and cellar operations undertaken to adjust the musts acidity, therefore improving wine quality and reducing production costs.

2010

Rodríguez, María Eugenia, Christian A Lopes, Raúl J Barbagelata, Nora B Barda, and Adriana C Caballero. (2010) 2010. “Influence of Candida Pulcherrima Patagonian Strain on Alcoholic Fermentation Behaviour and Wine Aroma.”. International Journal of Food Microbiology 138 (1-2): 19-25. https://doi.org/10.1016/j.ijfoodmicro.2009.12.025.

The use of selected Saccharomyces and non-Saccharomyces strains as mixed starters in winemaking would have advantages over the traditional spontaneous fermentation, producing wines with predictable and desirable characteristics. The aim of this study was to evaluate the impact of metabolic interactions between Patagonian indigenous Saccharomyces cerevisiae MMf9 and beta-glucosidase producer Candida pulcherrima V(6) strains on alcoholic fermentation behaviour and wine aroma Three inoculation strategies, simultaneous, sequential and final, were assayed at laboratory-scale fermentations using Muscat d'Alexandrie grape juice as substrate. The fermentation and yeast growth kinetics as well as the physicochemical and the sensory quality of wine were evaluated. Results evidenced that the sequential inoculation is the most adequate strategy of strains combination. The kinetic behaviour of sequential fermentation was similar to a successful spontaneous fermentation and its wine showed differential aromatic quality as evidenced through PC analysis using physicochemical and aromatic composition data. This wine presented the highest total concentration of higher alcohol, esters and terpenols and the strongest fruity and floral aroma.

2007