scholarly journals Cellular Responses Induced by Zinc in Zebra Mussel Haemocytes. Loss of DNA Integrity as a Cellular Mechanism to Evaluate the Suitability of Nanocellulose-Based Materials in Nanoremediation

Nanomaterials ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 2219
Author(s):  
Patrizia Guidi ◽  
Margherita Bernardeschi ◽  
Mara Palumbo ◽  
Vittoria Scarcelli ◽  
Massimo Genovese ◽  
...  
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Soft Tissues ◽  
Dna Integrity ◽  
Genetic Damage ◽  
Morphological Alterations ◽  
Wide Range ◽  
Zinc Concentrations ◽  
Primary Damage ◽  
Cytome Assay

Zinc environmental levels are increasing due to human activities, posing a threat to ecosystems and human health. Therefore, new tools able to remediate Zn contamination in freshwater are highly recommended. Specimens of Dreissena polymorpha (zebra mussel) were exposed for 48 h and 7 days to a wide range of ZnCl2 nominal concentrations (1–10–50–100 mg/L), including those environmentally relevant. Cellulose-based nanosponges (CNS) were also tested to assess their safety and suitability for Zn removal from freshwater. Zebra mussels were exposed to 50 mg/L ZnCl2 alone or incubated with 1.25 g/L of CNS (2 h) and then removed by filtration. The effect of Zn decontamination induced by CNS has been verified by the acute toxicity bioassay Microtox®. DNA primary damage was investigated by the Comet assay; micronuclei frequency and nuclear morphological alterations were assessed by Cytome assay in mussels’ haemocytes. The results confirmed the genotoxic effect of ZnCl2 in zebra mussel haemocytes at 48 h and 7-day exposure time. Zinc concentrations were measured in CNS, suggesting that cellulose-based nanosponges were able to remove Zn(II) by reducing its levels in exposure waters and soft tissues of D. polymorpha in agreement with the observed restoration of genetic damage exerted by zinc exposure alone.

scholarly journals Quantification of assembly forces during creation of head-neck taper junction considering soft tissue bearing: a biomechanical study

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Toni Wendler ◽  
Torsten Prietzel ◽  
Robert Möbius ◽  
Jean-Pierre Fischer ◽  
Andreas Roth ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Work Experience ◽  
Soft Tissues ◽  
Force Sensor ◽  
Biomechanical Study ◽  
Measuring System ◽  
Wide Range ◽  
Head Neck

Abstract Background All current total hip arthroplasty (THA) systems are modular in design. Only during the operation femoral head and stem get connected by a Morse taper junction. The junction is realized by hammer blows from the surgeon. Decisive for the junction strength is the maximum force acting once in the direction of the neck axis, which is mainly influenced by the applied impulse and surrounding soft tissues. This leads to large differences in assembly forces between the surgeries. This study aimed to quantify the assembly forces of different surgeons under influence of surrounding soft tissue. Methods First, a measuring system, consisting of a prosthesis and a hammer, was developed. Both components are equipped with a piezoelectric force sensor. Initially, in situ experiments on human cadavers were carried out using this system in order to determine the actual assembly forces and to characterize the influence of human soft tissues. Afterwards, an in vitro model in the form of an artificial femur (Sawbones Europe AB, Malmo, Sweden) with implanted measuring stem embedded in gelatine was developed. The gelatine mixture was chosen in such a way that assembly forces applied to the model corresponded to those in situ. A study involving 31 surgeons was carried out on the aforementioned in vitro model, in which the assembly forces were determined. Results A model was developed, with the influence of human soft tissues being taken into account. The assembly forces measured on the in vitro model were, on average, 2037.2 N ± 724.9 N, ranging from 822.5 N to 3835.2 N. The comparison among the surgeons showed no significant differences in sex (P = 0.09), work experience (P = 0.71) and number of THAs performed per year (P = 0.69). Conclusions All measured assembly forces were below 4 kN, which is recommended in the literature. This could lead to increased corrosion following fretting in the head-neck interface. In addition, there was a very wide range of assembly forces among the surgeons, although other influencing factors such as different implant sizes or materials were not taken into account. To ensure optimal assembly force, the impaction should be standardized, e.g., by using an appropriate surgical instrument.

Body size-dependent Cd accumulation in the zebra mussel Dreissena polymorpha from different routes

Chemosphere ◽  
2017 ◽  
Vol 168 ◽  
pp. 825-831 ◽  
Author(s):  
Wen-Li Tang ◽  
Douglas Evans ◽  
Lisa Kraemer ◽  
Huan Zhong
Keyword(s):  
Body Size ◽  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Cd Accumulation ◽  
Size Dependent

scholarly journals Effects of Forced Hot Air on Zebra Mussel (Dreissena polymorpha) Survival

1998 ◽  
Vol 13 (3) ◽  
pp. 365-367 ◽  
Author(s):  
Thomas Ussery ◽  
Andrew C. Miller ◽  
Barry S. Payne
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha ◽  
Hot Air

scholarly journals Genome-Wide Identification of Resveratrol Intrinsic Resistance Determinants in Staphylococcus aureus

Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 82
Author(s):  
Liping Liu ◽  
Hanne Ingmer ◽  
Martin Vestergaard
Keyword(s):  
Staphylococcus Aureus ◽  
Stress Response ◽  
Inhibitory Activity ◽  
Bacterial Species ◽  
Dna Integrity ◽  
Intrinsic Resistance ◽  
Potential Health ◽  
Cellular Effects ◽  
Development Of Resistance ◽  
Wide Range

Resveratrol has been extensively studied due to its potential health benefits in multiple diseases, for example, cancer, obesity and cardiovascular diseases. Besides these properties, resveratrol displays inhibitory activity against a wide range of bacterial species; however, the cellular effects of resveratrol in bacteria remain incompletely understood, especially in the human pathogen, Staphylococcus aureus. In this study, we aimed to identify intrinsic resistance genes that aid S. aureus in tolerating the activity of resveratrol. We screened the Nebraska Transposon Mutant Library, consisting of 1920 mutants with inactivation of non-essential genes in S. aureus JE2, for increased susceptibly to resveratrol. On agar plates containing 0.5× the minimum inhibitory concentration (MIC), 17 transposon mutants failed to grow. Of these, four mutants showed a two-fold reduction in MIC, being the clpP protease mutant and three mutants with deficiencies in the electron transport chain (menD, hemB, aroC). The remaining 13 mutants did not show a reduction in MIC, but were confirmed by spot-assays to have increased susceptibility to resveratrol. Several genes were associated with DNA damage repair (recJ, xerC and xseA). Treatment of S. aureus JE2 with sub-inhibitory concentrations of resveratrol did not affect the expression of recJ, xerC and xseA, but increased expression of the SOS–stress response genes lexA and recA, suggesting that resveratrol interferes with DNA integrity in S. aureus. Expression of error-prone DNA polymerases are part of the SOS–stress response and we could show that sub-inhibitory concentrations of resveratrol increased overall mutation frequency as measured by formation of rifampicin resistant mutants. Our data show that DNA repair systems are important determinants aiding S. aureus to overcome the inhibitory activity of resveratrol. Activation of the SOS response by resveratrol could potentially facilitate the development of resistance towards conventional antibiotics in S. aureus.

Metallothionein (MT) response after chronic palladium exposure in the zebra mussel, Dreissena polymorpha

2008 ◽  
Vol 108 (3) ◽  
pp. 309-314 ◽  
Author(s):  
Sabrina N. Frank ◽  
Christoph Singer ◽  
Bernd Sures
Keyword(s):  
Zebra Mussel ◽  
Dreissena Polymorpha
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