Search results for "DAMAGE"

Induction of DNA damage and expression of heat shock protein HSP70 by polychlorinated biphenyls in the marine sponge Suberites domuncula Olivi

1999

The effects of different polychlorinated biphenyls (PCBs) including toxic coplanar non-ortho (PCB77) and non-planar mono-ortho (PCB118) and di-ortho (PCB153) congeners on the extent of DNA damage as well as on the expression of heat shock protein 70 (HSP70) were investigated in the marine sponge Suberites domuncula Olivi (Porifera; Demospongiae). A time-dependent increase in the number of DNA single-strand breaks, expressed as strand scission factor (SSF), was found after injection of a single dose of 25 mu g of PCB 118 or PCB 153 per gram wet mass of S. domuncula, using Fast Micromethod assay, which is based on the unwinding of DNA under alkaline conditions. The number of strand breaks ind…

[33] Use of repair endonucleases to assess DNA damage by peroxynitrite

1999

Publisher Summary This chapter discusses the use of repair endonucleases to assess DNA damage by peroxynitrite. Repair endonucleases allow a convenient quantification of various types of oxidative modifications induced by peroxynitrite, both in cultured cells and in cell-free DNA. The high sensitivity of the assays allows highly ectotoxic exposure conditions to be avoided—as well as the generation of secondary DNA modifications—that often become a problem at high levels of damage because primary DNA oxidation products can be orders of magnitude more reactive than the original bases, as demonstrated for the reaction of 8-hydroxyguanine with singlet oxygen. The ratio of the various types of m…

Photoinduced DNA Lesions in Dormant Bacteria. The Peculiar Route Leading to Spore Photoproduct Unraveled by Multiscale Molecular Dynamics

2020

Some bacterial species enter a dormant state in the form of spores to resist to unfavorable external conditions. Spores are resistant to a wide series of stress agents, including UV radiation, and can last for tens to hundreds of years. Due to the suspension of biological functions such as DNA repair, they accumulate DNA damage upon exposure to UV radiation. Differently from active organisms, the most common DNA photoproduct in spores are not cyclobutane pyrimidine dimers, but rather the so-called spore photoproduct. This non-canonical photochemistry results from the dry state of DNA and the binding to small acid soluble proteins that drastically modify the structure and photoreactivity of …

Squaraine Dyes for Photodynamic Therapy: Mechanism of Cytotoxicity and DNA Damage Induced by Halogenated Squaraine Dyes Plus Light (>600 nm)¶

2004

Halogenated squaraine dyes 1 and 2 possess favorable photophysical and in vitro photobiological properties that make these new class of molecules interesting for photodynamic therapeutic applications. For a better understanding of the mechanism of their photobiological activity, we have analyzed the DNA damage and the cytotoxicity induced by these photosensitizers in mammalian cells and cell-free systems in the presence and absence of various additives and scavengers. Both photoactivated squaraines were found to be similar efficient in inducing single-strand breaks (SSB) in cell-free DNA when compared with the cellular DNA. Superoxide dismutase and catalase did not show any influence. Howev…

2021

The purpose of this study was to investigate blood-based biomarkers and their regulation with regard to different recovery-stress states. A total of 35 male elite athletes (13 badminton, 22 soccer players) were recruited, and two venous blood samples were taken: one in a ‘recovered’ state (REC) after a minimum of one-day rest from exercise and another one in a ‘non-recovered’ state (NOR) after a habitual loading microcycle. Overall, 23 blood-based biomarkers of different physiologic domains, which address inflammation, muscle damage, and tissue repair, were analyzed by Luminex assays. Across all athletes, only creatine kinase (CK), interleukin (IL-) 6, and IL-17A showed higher concentration…

Post-acute COVID-19 neurological syndrome: a new medical 2 challenge

2021

In December 2019, inWuhan (China), a highly pathogenic coronavirus, named SARS-CoV-2, dramatically emerged. This new virus, which causes severe pneumonia, is rapidly spreading around the world, hence it provoked the COVID-19 pandemic. This emergency launched by SARS-CoV-2 also had, and still has, devastating socio-economic aspects. Assessing the impact of COVID-19 on vulnerable groups of people is crucial for the adaptation of governments' responses. Growing scientific evidence suggests that it is essential to keep the attention on people after acute SARSCoV- 2 infection; indeed, some clinical manifestations are frequently present even after recovery. There is consensus on the need to defin…

Aspetti valutativi nella costruzione del sistema informativo per la gestione ambientale dell'azienda

2013

This paper deals with the construction of an environmental management oriented corporate information system. A company point of view is adopted and a managerial approach is integrated with an evaluative approach. The work provides a critical reflection on the nature of corporate environmental responsibility and on the contribution of evaluation discipline for environment oriented improving of the traditional economic and financial corporate information system. Corporate management recognizes the principle that governs the activity of a company in the creation of economic value. In production processes, the neg-entropic aspects − relating to produced goods and other tangible and intangible b…

A New Wireless Device for Real-Time Mechanical Impact Evaluation in a Citrus Packing Line

2020

Abstract. Postharvest handling of fresh fruit is a potential source of bruising and damage, with significant consequences for fruit quality and marketability. In the last 30 years, different types of impact-recording devices (also called electronic fruits or pseudo-fruits) have been developed with the aim of measuring the impacts experienced by fruits during postharvest operations. The aim of this study was to develop and test a novel wireless instrumented sphere to study the critical points in a citrus packing line by measuring the impacts experienced by fruits in real-time. The non-commercial device was based on a MEMS (micro-electro-mechanical system) sensor node with a sensing range fro…

A damage identification procedure based on Hilbert transform: Experimental validation

2010

SUMMARY This paper aims at validating the feasibility of an identification procedure, based on the use of the Hilbert transform, by means of experimental tests for shear-type multi-degree-of-freedom systems. Particularly, a three-degree-of-freedom frame will be studied either numerically or experimentally by means of a laboratory scale model built at the laboratory of the Structural, Aerospace and Geotechnical Engineering Department (DISAG) of University of Palermo. Several damage scenarios have been considered to prove the effectiveness of the procedure. Moreover, the experimental tests have been conducted by considering two different input loads: pulse forces, simulated by means of an ins…

Damage identification by Lévy ant colony optimization

2010

This paper deals with the identification of incipient damage in structural elements by non-destructive test based on experimentally measured structural dynamical response. By applycation of the Hilbert transform to the recorded signal the so-called phase of the analytical signal is recovered and a proper functional is constructed in such a way that its global minimum gives a measure of the damage level, meant as stiffness reduction. Minimization is achieved by applying a modified Ant Colony Optimization (ACO) for continuous variables, inspired by the ants’ forageing behavior. The modification consists in the application of a new perturbation operator, based on alpha stable Lévy distribution…