Vitamin D deficiency causes inward hypertrophic remodeling and alters vascular reactivity of rat cerebral arterioles

BACKGROUND AND PURPOSE: Vitamin D deficiency (VDD) is a global health problem, which can lead to several pathophysiological consequences including cardiovascular diseases. Its impact on the cerebrovascular system is not well understood. The goal of the present work was to examine the effects of VDD on the morphological, biomechanical and functional properties of cerebral arterioles. METHODS: Four-week-old male Wistar rats (n = 11 per group) were either fed with vitamin D deficient diet or received conventional rat chow with per os vitamin D supplementation. Cardiovascular parameters and hormone levels (testosterone, androstenedione, progesterone and 25-hydroxyvitamin D) were measured during the study. After 8 weeks of treatment anterior cerebral artery segments were prepared and their morphological, biomechanical and functional properties were examined using pressure microangiometry. Resorcin-fuchsin and smooth muscle actin staining were used to detect elastic fiber density and smooth muscle cell counts in the vessel wall, respectively. Sections were immunostained for eNOS and COX-2 as well. RESULTS: VDD markedly increased the wall thickness, the wall-to-lumen ratio and the wall cross-sectional area of arterioles as well as the number of smooth muscle cells in the tunica media. As a consequence, tangential wall stress was significantly lower in the VDD group. In addition, VDD increased the myogenic as well as the uridine 5'-triphosphate-induced tone and impaired bradykinin-induced relaxation. Decreased eNOS and increased COX-2 expression were also observed in the endothelium of VDD animals. CONCLUSIONS: VDD causes inward hypertrophic remodeling due to vascular smooth muscle cell proliferation and enhances the vessel tone probably because of increased vasoconstrictor prostanoid levels in young adult rats. In addition, the decreased eNOS expression results in endothelial dysfunction. These morphological and functional alterations can potentially compromise the cerebral circulation and lead to cerebrovascular disorders in VDD

Risk management of road and rail transport of hazardous materials in Sicily

A Transportation Risk Analysis (TRA) tool has been used to accurately assess the risk associated to a variety of road and rail transportation cases representative of hazardous materials transport by land in Sicily. Due to the high risk level, some risk mitigation options have been investigated: the possibility of changing route and/or transport modalities have been examined for each transportation activity, all the combinations of road, rail and intermodal (roadCrail) transport have been calculated and that minimising the risk has been identified with the aid of the TRA tool

Monitoraggio e gestione dei meccanismi di deterioramento di attrezzature in pressione attraverso un approccio ontologico

Le attrezzature industriali in pressione, destinate al contenimento o alla conversione di sostanze pericolose, e i loro componenti sono soggetti a fenomeni di invecchiamento che, nel corso del tempo, possono influenzare i livelli di sicurezza dell’intero stabilimento in quanto aumentano il rischio di perdita di contenimento e riducono la performance dell’intero impianto. L’invecchiamento si manifesta come una forma generale di degrado del componente, che non è associata solo al tempo in servizio ma alla sua condizione e a come esso cambia nel corso del tempo. I meccanismi più comuni, con cui le attrezzature deteriorano, rappresentano una percentuale significativa di guasti e di sostituzioni di componenti. Tuttavia, il deterioramento si verifica anche a causa di molti altri fattori associati ad aspetti di progettazione, di gestione, etc. La conoscenza dei meccanismi con cui avviene il fenomeno (ovvero delle relazioni “causa-effetto”, “condizioni al contorno-velocità di propagazione” ed “identificazione-misura”) e delle misure di prevenzione sono utili al fine di monitorare il deterioramento delle attrezzature e di attuare una gestione sicura del fenomeno. In questo articolo, si propone un approccio di esplorazione di tali relazioni basato su una interpretazione ontologica dei meccanismi di deterioramento, con l'obiettivo di supportare il monitoraggio dell’invecchiamento di attrezzature e componenti industriali. Per raggiungere l'obiettivo, l'approccio proposto utilizza i concetti e le relazioni già definite per i più comuni meccanismi, cui sono soggetti le attrezzature, all’interno della pratica americana API 581. Detti meccanismi verranno definiti attraverso dei domini ontologici

HazMat transport through, Messina town: from risk analysis suggestions for improving territorial safety

In this paper, after briefly outlining the main features of TRAT2, its application to the land transport of dangerous goods through the downtown of Messina is outlined. Owing to its particular location, there is a large flow of hazardous materials through the city of Messina. Many of these substances come from the greatest industrialised areas of Sicily. Goods reach the town by rail or road, and cross the Straits by ship. A complete inventory of dangerous substances, detailed in the paper, was the basis of a complete riskanalysis, whose results, obtained by means of the TRAT2 software, have been analysed and discussed. From both individual risk distribution and societal risk curves the importance of parameters has been obtained and this has suggested measures to improve the safety of the urban area

Bioartificial Sponges for Auricular Cartilage Engineering

Auricle reconstruction due to congenital, post-infective or post-traumatic defects represents a challenging procedure in the field of aesthetic and reconstructive surgery due to the highly complex three-dimensional anatomy of the outer ear. Tissue engineering aims to provide alternatives to overcome the shortcomings of standard surgical reconstructive procedure. In the present study, poly(vinyl alcohol)/gelatin (PVA/G) sponges at different weight ratios were produced via emulsion and freeze-drying, and crosslinked by exposure to glutaraldehyde vapors. PVA/G sponges gave rise to highly porous, water stable and hydrophilic scaffolds. Characterization of PVA/G sponges showed round-shaped interconnected pores, high swelling capacity (>200%) and viscoelastic mechanical behavior. The PVA/G 70/30 (w/w) scaffold was selected for in vitro biological studies. Bone marrow derived human mesenchymal stromal cells (hMSCs) were used and differentiated towards chondrogenic lineage under different culture conditions: 1) commercial versus handmade differentiation medium; 2) undifferentiated versus pre-differentiated hMSC seeding; and 3) static versus dynamic culture [i.e. ultrasound (US) or bioreactor stimulation]. Histological results highlighted intense glycosaminoglycan, glycoprotein and collagen syntheses after three weeks, mostly using the commercial medium, whereas round morphology was observed in pre-differentiated cells. In static culture, immunohistochemistry for chondrogenic markers revealed an early differentiation stage, characterized by the expression of Sox-9 and collagen type I fibers. The application of US on cell/scaffold constructs increased extracellular matrix deposition and resulted in 30% higher collagen type II expression at the gene level. Bioreactor culture induced collagen type II, aggrecan and elastin formation. This study demonstrated that 70/30 PVA/G sponge is a suitable candidate for auricle reconstruction