1,721,196 research outputs found
Measurement of total oxyradical scavenging capacity as an useful tool for understanding susceptibility to oxidative stress conditions
No full textRole of the chronic air pollution levels in the Covid-19 outbreak risk in Italy
Full text linkAfter the initial outbreak in China, the diffusion in Italy of SARS-CoV-2 is exhibiting a clear regional trend
with more elevated frequency and severity of cases in Northern areas. Among multiple factors possibly
involved in such geographical differences, a role has been hypothesized for atmospheric pollution. We
provide additional evidence on the possible influence of air quality, particularly in terms of chronicity of
exposure on the spread viral infection in Italian regions. Actual data on Covid-19 outbreak in Italian
provinces and corresponding long-term air quality evaluations, were obtained from Italian and European
agencies, elaborated and tested for possible interactions. Our elaborations reveal that, beside concentrations, the chronicity of exposure may influence the anomalous variability of SARS-CoV-2 in Italy. Data
on distribution of atmospheric pollutants (NO2, O3, PM2.5 and PM10) in Italian regions during the last 4
years, days exceeding regulatory limits, and years of the last decade (2010e2019) in which the limits
have been exceeded for at least 35 days, highlight that Northern Italy has been constantly exposed to
chronic air pollution. Long-term air-quality data significantly correlated with cases of Covid-19 in up to
71 Italian provinces (updated April 27, 2020) providing further evidence that chronic exposure to atmospheric contamination may represent a favourable context for the spread of the virus. Proinflammatory responses and high incidence of respiratory and cardiac affections are well known,
while the capability of this coronavirus to bind particulate matters remains to be established. Atmospheric and environmental pollution should be considered as part of an integrated approach for sustainable development, human health protection and prevention of epidemic spreads but in a long-term
and chronic perspective, since adoption of mitigation actions during a viral outbreak could be of limited
utility
Characterisation of antioxidant defences in three Antarctic notothenioid species from Terra Nova Bay (Ross Sea)
No full textOxidative challenge is an important factor affecting the adaptive strategies of Antarctic fish, but data on antioxidant
defences in these organisms remain scarce. In this investigation, individual antioxidants and the total oxyradical scavenging capacity
(TOSC) were characterised in three notothenioid species, Trematomus bernacchii, Trematomus hansoni and Trematomus newnesi;
seasonal fluctuations were further analysed in T. bernacchii sampled during different periods of the reproductive cycle, ice melting
and phytoplanktonic blooms. The overall results revealed only limited differences between the three notothenioids, with greater
TOSC values in T. hansoni and T. newnesi. The capacity for decomposing hydrogen peroxide via catalase was not particularly
enhanced in these fish, in contrast to the prominent role of the enzyme in Antarctic invertebrates. An alternative antioxidant strategy,
based on the efficiency of low molecular mass scavengers was suggested, especially for T. bernacchii which had higher levels of
glutathione and glutathione reductase; the diet composition of the investigated species might explain the differences in tissue
antioxidants. Oxidative stress responses revealed almost constant values between November and January in T. bernacchii, a quite
unusual and unexpected result considering the marked changes occurring in several biological and environmental factors. In this
respect, the antioxidant efficiency of T. bernacchii would counteract the naturally elevated environmental pro-oxidant conditions
and the associated potential increase in oxidative challenge, i.e. spawning period, sea-ice melting, phytoplanktonic development
and the seasonal increase in cadmium bioavailability at Terra Nova Ba
Effects of copper and cadmium on the presence of renal concretions in the bivalve Donacilla cornea.
No full text
Lysosomal and antioxidant defenses to metals in the Antarctic scallop Adamissiun colbecki
No full textLysosomal and antioxidant responses were investigated in the Antarctic scallop Adamussium colbecki exposed under
laboratory conditions to metals as well as in specimens transplanted from a pristine area to the Bay receiving the discharges of the
Italian Base. Exposure to copper and mercury resulted in a significant reduction of lysosomal membrane stability and in the
appearance of severe morphological alterations varying from the presence of enlarged lysosomes to the loss of lysosomal
structures. More limited effects were observed in Pb-exposed scallops. Moreover, laboratory exposures to Cu and Hg greatly
depleted the levels of total glutathione and the activities of catalase and glutathione S-transferases were significantly reduced. More
variable were the responses of glutathione peroxidases while superoxide dismutase remained almost constant. The interaction
between lysosomal alterations and antioxidant defences is discussed and the results interpreted in view of the extreme
environmental conditions for the Antarctic organisms. The results obtained from the transplantation experiment indicated only very
limited effects on scallops translocated near the effluents of the Italian Base suggesting that the biological impact of the Base should
not have major deleterious consequences on benthic marine communities
Defenses against oxidative stress in the Antarctic scallop Adamussium colbecki and effects of acute exposure to metals
No full textSince a general pathway of toxicity induced by pollutants is the enhancement of reactive oxygen species, biochemical
responses associated with variations in the antioxidant cellular system have been often proposed as biomarkers of pollutantmediated
toxicity associated with oxidative stress. Antarctic organisms live in an extreme environment characterized by low water
temperature, high level of dissolved oxygen, presence of ice and strong seasonal changes in light intensity and availability of food,
conditions which could influence both the formation of reactive oxygen species and the mechanisms for their removal. In this
respect and considering the utility of this as a key species for monitoring marine Antarctic environment it was of interest to
investigate the antioxidant defense system of the scallop Adamussium colbecki.
The parameters examined in the digestive gland of the scallop were the concentration of glutathione and the activity of several
glutathione dependent and antioxidant enzymes (glyoxalase I and II, glutathione S-transferases, glutathione peroxidases, glutathione
reductase, catalase, superoxide dismutase). Very high levels of catalase suggest a possible adaptation to Antarctic extreme
conditions, while the high activities of glutathione S-transferases are more probably related to the feeding behavior of Pectinids.
Enzymes from Adamussium colbecki generally appeared to be active at low temperatures but, with a few exceptions, their activities
increased with rising temperature. Exposure of A. colbecki to sublethal concentrations of Cu or Hg resulted in a significant
reduction in the levels of total glutathione and in the activity of catalase and glutathione S-transferases. Antioxidant responses of A.
colbecki could represent a useful tool in assessing the biological impact of environmental pollutants in the Antarctic ecosystems
Cholestatic liver reaction and heparin therapy
No full textAn unusual case of cholestatic hepatitis after heparin therapy is reported and discussed
Endocardial implantation of a cardioverter defibrillator in early childhood.
Full text linkINTRODUCTION: Experience in endovascular/endocardial techniques for implanting implantable cardioverter defibrillators in early childhood is limited. Potentially, this type of approach could limit the surgical risk, while increasing ICD therapy efficacy. The safety and feasibility of adopting a complete endovascular/endocardial approach for implanting ICDs is assessed by considering the cases of two young children.
METHODS AND RESULTS: Two boys, aged 3 and 6 years, were implanted with ICD for a history of syncope and documented ventricular tachycardia (VT). A complete endovascular/endocardial approach was adopted consisting of positioning a bipolar pacing and sensing lead in the right ventricular (RV) apex with intravascular redundancy forming a loop in the inferior vena cava (IVC), and a caval coil placed in the IVC. Sensing values (7-8 mV), pacing threshold (0.5-0.6 V/0.5 msec), and defibrillation testing (case 1 = 10 J, case 2 = 20 J) were all acceptable. During follow-up, in both cases ICD intervened correctly. In one case, 16 months after implantation, because of change in the IVC coil-active can vector, the IVC coil was effectively repositioned to a more distal position.
CONCLUSION: A complete endovascular/endocardial ICD implantation technique in early childhood is both feasible and safe. This approach avoids thoracotomy and ensures ICD therapy efficacy
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