Pros and Cons of CAD/CAM Technology for Infection Prevention in Dental Settings during COVID-19 Outbreak.

The purpose of this commentary is to update the evidence reported in our previous review on the advantages and limitations of computer-aided design/computer-aided manufacturing technology in the promotion of dental business, as well as to guarantee patient and occupational safety. The COVID-19 pandemic led to an unprecedented focus on infection prevention; however, waves of COVID-19 follow one another, asymptomatic cases are nearly impossible to identify by triage in a dental setting, and the effectiveness of long-lasting immune protection through vaccination remains largely unknown. Different national laws and international guidelines (mainly USA-CDC, ECDC) have often brought about dissimilar awareness and operational choices, and in general, there has been very limited attention to this technology. Here, we discuss its advantages and limitations in light of: (a) presence of SARS-CoV-2 in the oral cavity, saliva, and dental biofilm and activation of dormant microbial infections; (b) the prevention of SARS-CoV-2 transmission by aerosol and fomite contamination; (c) the detection of various oral manifestations of COVID-19; (d) specific information for the reprocessing of the scanner tip and the ward from the manufacturers.

Innovation by Computer-Aided Design/Computer-Aided Manufacturing Technology: A Look at Infection Prevention in Dental Settings.

Recent data indicates limited awareness and compliance on infection prevention procedures by dental offices and by dental laboratories. Guidelines for infection prevention in dentistry have been published by Centres for Disease Control and Prevention since 2003; the section "IX-Special consideration" includes a subsection concerning the prevention in dental laboratories, but it has not been modernised in later versions to fit the needs of traditional and computer-aided technology. Traditional techniques required disinfecting items (impression, chewing waxes, and appliances) with well-suited products, which are also chosen for limiting impression changes or appliance deterioration. Effective procedures are available with difficulties. Some of these contain irritant or non-eco-friendly disinfectants. The transport of impression, to dental laboratories, is often delayed with limited precautions for limiting cross-infection. Gypsum casts are frequently contaminated mainly by bacteria and their antibiotic-resistant strains and even stored for long periods during dental implant supported restoration and orthodontic therapy, becoming a hidden source of infection. Nowadays, computer-aided design/computer-aided manufacturing technology seems to be an interesting way to promote both business and safety, being more comfortable for patients and more accurate than traditional technology. A further advantage is easier infection prevention since, for the most part, mainly digital impression and casts are not a source of cross-infection and the transport of contaminated items is reduced and limited to try-in stages. Nevertheless, a peculiar feature is that a digital electronic file is of course unalterable, but may be ruined by a computer virus. Additionally, the reconditioning of scanner tips is determinant for the optical characteristics and long term use of the scanner, but information for its reconditioning from producers is often limited. This study focuses on some critical points including (a) insufficient guidelines, (b) choice of proper procedure for scanner reconditioning, and (c) data protection in relation to patient privacy.

Stem Cells toward the Future: The Space Challenge.

Astronauts experience weightlessness-induced bone loss due to an unbalanced process of bone remodeling that involves bone mesenchymal stem cells (bMSCs), as well as osteoblasts, osteocytes, and osteoclasts. The effects of microgravity on osteo-cells have been extensively studied, but it is only recently that consideration has been given to the role of bone MSCs. These live in adult bone marrow niches, are characterized by their self-renewal and multipotent differentiation capacities, and the published data indicate that they may lead to interesting returns in the biomedical/bioengineering fields. This review describes the published findings concerning bMSCs exposed to simulated/real microgravity, mainly concentrating on how mechanosignaling, mechanotransduction and oxygen influence their proliferation, senescence and differentiation. A comprehensive understanding of bMSC behavior in microgravity and their role in preventing bone loss will be essential for entering the future age of long-lasting, manned space exploration.

The challenging environment on board the International Space Station affects endothelial cell function by triggering oxidative stress through thioredoxin interacting protein overexpression: the ESA-SPHINX experiment.

Exposure to microgravity generates alterations that are similar to those involved in age-related diseases, such as cardiovascular deconditioning, bone loss, muscle atrophy, and immune response impairment. Endothelial dysfunction is the common denominator. To shed light on the underlying mechanism, we participated in the Progress 40P mission with Spaceflight of Human Umbilical Vein Endothelial Cells (HUVECs): an Integrated Experiment (SPHINX), which consisted of 12 in-flight and 12 ground-based control modules and lasted 10 d. Postflight microarray analysis revealed 1023 significantly modulated genes, the majority of which are involved in cell adhesion, oxidative phosphorylation, stress responses, cell cycle, and apoptosis. Thioredoxin-interacting protein was the most up-regulated (33-fold), heat-shock proteins 70 and 90 the most down-regulated (5.6-fold). Ion channels (TPCN1, KCNG2, KCNJ14, KCNG1, KCNT1, TRPM1, CLCN4, CLCA2), mitochondrial oxidative phosphorylation, and focal adhesion were widely affected. Cytokine detection in the culture media indicated significant increased secretion of interleukin-1α and interleukin-1ß. Nitric oxide was found not modulated. Our data suggest that in cultured HUVECs, microgravity affects the same molecular machinery responsible for sensing alterations of flow and generates a prooxidative environment that activates inflammatory responses, alters endothelial behavior, and promotes senescence.

Oxidative stress and alterations in actin cytoskeleton trigger glutathione efflux in Saccharomyces cerevisiae.

A marked deficiency in glutathione (GSH), the most abundant antioxidant in living systems, plays a major role in aging and the pathogenesis of diseases ranging from neurological disorders to early atherosclerosis and the impairment of various immunological functions. In an attempt to shed light on GSH homeostasis, we carried out the space experiment SCORE (Saccharomyces cerevisiae oxidative stress response evaluation) during the FOTON-M3 mission. Microgravity and hyperoxic conditions induced an enormous extracellular release of GSH from S. cerevisiae cells (≈40% w/dw), changed the distribution of the buds, and activated the high osmolarity glycerol (HOG) and cell integrity/PKC pathways, as well as protein carbonylation. The results from the single spaceflight experiment were validated by a complete set of experiments under conditions of simulated microgravity and indicate that cytoskeletal alterations are mainly responsible for the observed effects. The results of ground experiments in which we induced cytoskeletal modifications by means of treatment with dihydrocytochalasin B (DHCB), a potent inhibitor of actin polymerisation, or (R)-(+)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide dihydrochloride monohydrate (Y-27632), a selective ROCK (Rho-associated coiled-coil forming protein serine/threonine kinase) inhibitor, confirmed the role of actin in GSH efflux. We also found that the GSH release can be inhibited using the potent chloride channel blocker 5-nitro-2-(3-phenylpropylamino) benzoic acid (NPPB).

Cardiovascular protective effects of resveratrol.

Resveratrol (3,4',5-trihydroxy-trans-stilbene), a phytoalexin found in grape skins, peanuts, and red wine, has been reported to have a wide range of biological and pharmacological properties. It has been speculated that at low doses (such as consumed in the common diet) resveratrol may have cardioprotective activity. In this article we describe recent in vitro and in vivo studies in animal models. The results of these studies suggest that resveratrol modulates vascular cell function, inhibits LDL oxidation, suppresses platelet aggregation and reduces myocardial damage during ischemia-reperfusion. Although the reported biological data indicate that resveratrol is a highly promising cardiovascular protective agent, more studies are needed to establish its bioavailability and in vivo cardioprotective effects, particularly in humans.

Simulated weightlessness in the design and exploitation of a NMR-compatible bioreactor.

Mammalian cells cultured in simulated weightlessness take advantage of a favorable environment, experiencing low shear stress and reduced turbulence. NMR spectroscopy allows the on-line noninvasive monitoring of cell growth and metabolism. With this in mind, we developed a novel bioreactor that fits into a NMR instrument and in which the simulated weightlessness conditions are obtained by a suitable medium and a flow-lift suspension. In detail, the gravitational vector acting on cells is counterbalanced by the hydrodynamic thrusts created by a bottom-up spiral flow of a fluid having increased density. We validate its efficiency (a) by calculating the main physical parameters as relative velocity, shear stress, and oxygen transport, and (b) by comparing the experimental results of growing a cell culture in the proposed bioreactor with those obtained using an established simulated weightlessness system (rotating wall vessel, NASA). As a test study we focused on the proliferation of human umbilical vein endothelial cells (HUVEC) in terms of cell viability and organization of their cytoskeleton.

Resveratrol provides late-phase cardioprotection by means of a nitric oxide- and adenosine-mediated mechanism.

We used two experimental models to prove that resveratrol (trans-3,4',5-trihydroxystilbene) reduces cardiac ischemic-reperfusion injury by means of a nitric oxide- and adenosine-dependent mechanism. (1). ACUTE EX VIVO: resveratrol (10 microM, 10 min) infusion in Langendorff-perfused normoxic rat hearts significantly increased adenosine release and coronary flow compared with baseline. After 30-min low-flow ischemia, vasodilation, still present at reperfusion, was completely abolished by resveratrol plus adenosine antagonist 8-(p-sulfophenyl)theophylline (SPT, 50 microM) administration. (2). CHRONIC IN VIVO: rats received tap water containing 25 mg/l resveratrol for 15 days or normal water. Twenty-four hours after, their hearts were Langendorff-perfused and submitted to 60-min low-flow ischemia and reperfusion. The resveratrol-treated hearts showed better functional recovery at reperfusion and significant vasodilation, but no variation in high-energy phosphates (31P Nuclear Magnetic Resonance). N(G)-nitro-L-arginine methyl ester (L-NAME, 30 microM), a nonselective nitric oxide synthase inhibitor, or SPT (50 microM) administered for 10 min prior to the low-flow ischemia cancelled the effects. This suggests that long-term moderate resveratrol consumption could play an important role in late cardioprotective effects.

Production of lovastatin examined by an integrated approach based on chemometrics and DOSY-NMR.

Microbial secondary metabolites are one of the sources of therapeutic molecules in the pharmaceutical industry. Product quality and high yields of secondary metabolites are the main goals for the commercial success of a fermentation process. Our novel approach was based on the decision-tree algorithm to determine the key variables correlated with the process outcome and on DOSY-NMR to identify both co-metabolites and impurities, and it improves fermentation systems and speeds up bioprocess development. The approach has been validated in the case of lovastatin production from Aspergillus terreus.