Circadian Rhythm and Cartilage Extracellular Matrix Genes in Osseointegration: A Genome-Wide Screening of Implant Failure by Vitamin D Deficiency

Successful dental and orthopedic implants require the establishment of an intimate association with bone tissue; however, the mechanistic explanation of how biological systems accomplish osseointegration is still incomplete. We sought to identify critical gene networks involved in osseointegration by exploring the implant failure model under vitamin D deficiency.Adult male Sprague-Dawley rats were exposed to control or vitamin D-deficient diet prior to the osteotomy surgery in the femur bone and the placement of T-shaped Ti4Al6V implant. Two weeks after the osteotomy and implant placement, tissue formed at the osteotomy site or in the hollow chamber of T-shaped implant was harvested and total RNA was evaluated by whole genome microarray analyses.Two-way ANOVA of microarray data identified 103 genes that were significantly (>2 fold) modulated by the implant placement and vitamin D deficiency. Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses assigned the highest z-score to the circadian rhythm pathway including neuronal PAS domain 2 (NPAS2), and period homolog 2 (Per2). NPAS2 and Aryl hydrocarbon receptor nuclear translocator-like (ARNTL/Bmal 1) were upregulated around implant and diminished by vitamin D deficiency, whereas the expression pattern of Per2 was complementary. Hierarchical cluster analysis further revealed that NPAS2 was in a group predominantly composed of cartilage extracellular matrix (ECM) genes. Whereas the expression of bone ECM genes around implant was not significantly affected by vitamin D deficiency, cartilage ECM genes were modulated by the presence of the implant and vitamin D status. In a proof-of-concept in vitro study, the expression of cartilage type II and X collagens was found upregulated when mouse mesenchymal stem cells were cultured on implant disk with 1,25D supplementation.This study suggests that the circadian rhythm system and cartilage extracellular matrix may be involved in the establishment of osseointegration under vitamin D regulation

Experiments to validate the NRCC smoke movement model for fire risk-cost assessment

Peer reviewed: YesNRC publication: Ye

Technological accidents caused by floods: The case of the Saga prefecture oil spill, Japan 2019

This study investigates an oil spill which involved an ironworks factory in Saga prefecture, during the severe flooding that hit southwestern Japan in late August 2019. The aim of the study is to provide an overview of the accident, highlighting the causes and the consequences of this compound disaster. Furthermore, the study analyses the emergency response and clean-up activities in order to identify lessons learned, and propose recommendations for future flood triggered oil spills. The work presented is based on the integration of information available in newspaper articles, government documents and reports, and data and interviews collected during two field trips in the affected area. The permanence of oil and the strong oil odour in adjacent crops as well as on irrigation canals and citizens’ houses was revealed during the first field trip, about one month after the accident. The analysis of the documentation on metal working oil revealed that it might have long-lasting impact in terms of environmental pollution. The presence of oil impacted also the implemented emergency response actions, since vertical evacuation, practiced by many residents during the disaster, actually put many of them in more danger as they ended up trapped in oil-covered floodwaters with strong vapours that were reported to cause nausea and skin irritation. Remarkably, it was also found that a previous oil spill had already occurred at the same site following a severe flooding event, highlighting the need to improve preparedness and develop more effective strategies for accident prevention. Disaster preparedness that specifically considers both the natural hazard and the potential for related technological scenarios should be enhanced, in particular regarding chemical accidents triggered by floods. Japan, as well as other parts of the World, is experiencing stronger rainfall events due to a changing climate leading to unprecedented flooding. Therefore, industry, government and citizens should consider the possibility of an increase of weather-related compound disasters in planning and implementation of climate change adaptation strategies