A comparative study of interaction between chicken egg white lysozyme (Lyz) with two hexavalent chromate ions; chromate and dichromate; which are prevalently known for their toxicity, was investigated using different spectroscopic techniques along with a molecular docking study. Both steady-state and time-resolved studies revealed that the addition of chromate/dichromate is responsible for strong quenching of intrinsic fluorescence in Lyz and the quenching is caused by both static and dynamic quenching mechanisms. Different binding and thermodynamic parameters were also calculated at different temperatures from the intrinsic fluorescence of Lyz. The conformational change in Lyz and thermodynamic parameters obtained during the course of interaction with chromate/dichromate were well-supported by the molecular docking results.
Currently, chromium is probably the most controversial transition metal. In recent publications it is clearly stated that it is not an essential micronutrient and should be considered to have a pharmacological effect. Conflicting scientific reports along with a huge amount of dietary supplements, as well as dietary and sports nutrients available on the market have prompted the authors to investigate the available information on the range of possible application, efficacy and safety of products containing salts or chelates of chromium III. The authors reviewed articles in electronic databases for the years 1959-2016, and selected works describing the biochemical, physiological and toxic properties of chromium salts and chelates and the range of possible applications in medicine, dietetics and sport. A critical analysis of reports dealing with the effect of chromium on the carbohydrate and lipid metabolism, body composition, lean body mass and sports performance was carried out. The authors indicated papers analyzing the mechanism of action of chromium in the cognitive and affective disorders. Much attention has been paid to the safety use of chromium III supplements. There are still some unsolved issues. In the field of toxicology, a limited number of reports about environmental exposure to trivalent chromium in the workplace draws our attention. In the field of biochemical research, there is still a need to clarify the mechanism of psychiatric and endocrinological activity, especially in conjunction with the immune system. Med Pr 2018;69(2):211-223.
- MeSH
- chrom metabolismus MeSH
- lidé MeSH
- metabolismus lipidů * MeSH
- metabolismus sacharidů * MeSH
- potravní doplňky * MeSH
- sloučeniny chromu metabolismus MeSH
- stopové prvky metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
The effect of hydro-alcoholic extract of Curculigo orchoides on hexavalent chromium (Cr VI) induced toxicity in rats was investigated. Sub-acute toxicity studies were performed by OECD guidelines. K2Cr2O7 (30 mg/kg) was administered to all groups except control group for a period of 28 days by oral gavage. Control group received distilled water; treatment groups received C. orchoides (25, 50 and 100 mg/kg). Cr(VI) administration resulted in up-regulation of serum biochemical parameters such as alanine transaminase, aspartate transaminase, alkaline phosphatase, and tissue biochemical markers viz. lipid peroxidation and protein carbonyl content. C. orchioides (100 mg/kg) significantly decreased these enzyme levels. The activities of anti-oxidant enzymes like superoxide dismutase, catalase and glutathione S-transferase were significantly decreased by Cr(VI) administration (50.7%, 43.7% and 37.9%, respectively). Further, mRNA expression studies and histopathology studies confirmed Cr(VI) toxicity. In all cases, C. orchioides promoted significant restoration of enzyme levels in a dose dependent manner. These results suggest the ameliorating effect of C. orchoides on Cr(VI) induced oxidative stress is probably via, modulation of cytokines, transcription factors and apoptotic genes.
- Klíčová slova
- Curculigo orchoides,
- MeSH
- antioxidancia farmakologie terapeutické užití MeSH
- chrom * toxicita MeSH
- Curculigo * MeSH
- dvojchroman draselný toxicita MeSH
- histologické techniky MeSH
- krysa rodu rattus MeSH
- oxidační stres účinky léků MeSH
- polymerázová řetězová reakce MeSH
- potkani Wistar MeSH
- rostlinné extrakty * farmakologie terapeutické užití MeSH
- stanovení celkové genové exprese MeSH
- testy toxicity metody statistika a číselné údaje MeSH
- western blotting MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- MeSH
- dvojchroman draselný * terapeutické užití MeSH
- extubace * MeSH
- homeopatie * MeSH
- lidé MeSH
- trvalý přetlak v dýchacích cestách MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- klinická studie MeSH
This paper presents the results of water, soil and air analyses taken in the vicinity of a former ferrochromium metallurgical plant. In the past, the area was used for the disposal of waste materials containing smelter slag, dust and other waste products from the manufacture of ferrochromium alloys for the army. Recently, production was abandoned and a project aimed at the liquidation of the dump has been initiated. The project concentrates on the recovery of chromium remains and the utilization of the leftover material as a road construction aggregate. Based on the analyses of ground water, soil and air, a health risk caused by environmental pollution with chromium, especially with Cr(VI), was determined for residential and occupational scenarios. It was found that the level of chromium emissions to the environment constitutes a potential danger of toxic and carcinogenic cases in humans exposed to the emission in the affected area. An increased level in the hazard quotient has been observed in the case of occupational activities. As far as the mutagenic effects are concerned, the occupational inhalation exposure was found to be very high, which may raise extreme concern about carcinogenic risk.
- MeSH
- chrom analýza MeSH
- dítě MeSH
- dospělí MeSH
- hodnocení rizik MeSH
- hutnictví MeSH
- inhalační expozice analýza MeSH
- konstrukční materiály * MeSH
- látky znečišťující životní prostředí analýza MeSH
- lidé MeSH
- prach analýza MeSH
- pracovní expozice analýza MeSH
- průmyslový odpad MeSH
- slitiny chromu analýza MeSH
- vláda MeSH
- voda analýza MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Polsko MeSH
UNLABELLED: PURPOSE OF THE STUDY The alloplastic materials currently used for protective surface layers on implants were tested in vitro under microbiological laboratory conditions by contamination with microbial agents most frequently found in deep infection of total joint replacements. The objective was to find out how the resistance to bacterial colonisation was related to different surface finishes. MATERIAL AND METHODS Each of 14 samples of alloplastic material currently used in the manufacture of orthopaedic implants was inoculated with each of the group of microorganisms most frequently infecting joint replacements; these were Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Enterococcus faecalis and Escherichia coli. At 24 hours of incubation, biofilms produced on sample surfaces were collected, stained with crystalline violet and assessed by spectrophotometry. The average value of biofilm absorbances (AV595) for the group of microorganism tested was taken as a basic characteristic of each material sample indicating its sensitivity to bacterial. RESULTS Of the metal materials with smooth surface finish, Vitalium (AV595, 0.368) showed the lowest affinity to microbial colonisation; next was titanium (AV595, 0.459) and steel (AV595, 0.505). A significant increase in sensitivity to bacterial colonisation was recorded in all types of surface finish of steel (AV595, 0.571) and in titanium alloy with a rough surface texture (AV595, 0.737 to 1.676); p < 0.05. Porous titanium surfaces significantly increased material affinity to colonisation. DISCUSSION Our study had certain limitations concerning in vitro evaluation of porous surfaces that have high affinity to bacterial colonisation. Porous titanium, and its hydroxyapatite layer in particular, considerably promotes osteoblast colonisation of the surface as well as implant osseointegration in the bone bed. Microorganisms therefore have no room for surface colonisation. Problematic may remain the surface parts outside contact with bone that keep their affinity to bacterial colonisation. CONCLUSIONS The material of choice for cemented implants is Vitalium which, of all metal surfaces, has the lowest sensitivity to bacterial colonisation. The materials of choice for cementless implants are titanium alloys. However, an osteoactive surface not in contact with bone remains a problem. On the one hand, its roughness and porosity are crucial to good osseointegration, on the other hand, its affinity to bacterial colonisation is high. KEY WORDS: alloplastic material, biofilm, joint replacement infection.
- MeSH
- artroplastiky kloubů přístrojové vybavení MeSH
- biofilmy růst a vývoj MeSH
- biokompatibilní materiály škodlivé účinky chemie MeSH
- Enterococcus faecalis fyziologie MeSH
- Escherichia coli fyziologie MeSH
- infekce spojené s protézou mikrobiologie MeSH
- lidé MeSH
- povrchové vlastnosti MeSH
- protézy a implantáty škodlivé účinky MeSH
- Pseudomonas aeruginosa fyziologie MeSH
- Staphylococcus aureus fyziologie MeSH
- Staphylococcus epidermidis fyziologie MeSH
- testování materiálů MeSH
- titan chemie MeSH
- vitalium chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
This work deals with non-destructive testing of artificial joints made from the austenitic steel SUS316L based on eddy current method. The technique is appropriate for final investigation of artificial joints before insertion the prosthesis into human body to avoid repeated operations. The most commonly implanted joints - knee and hip joint are evaluated in this study. The eddy current probe consists of one coil, which has both the excitation and sensing functions. Five detects are inspected using three different frequencies. The numerical simulations from Opera software with experiments are compared in this article to obtain the most appropriate frequency. The aim of this work is evaluation which frequency provides the biggest magnitude difference between individual simulated signals with various depths if surface defects are inspected.
- Klíčová slova
- testování umělých kloubů, vířivé proudy, austenitická ocel,
- MeSH
- kyčelní protézy * normy MeSH
- lidé MeSH
- protézy kloubů normy MeSH
- protézy kolene * normy MeSH
- slitiny chromu normy MeSH
- testování materiálů * metody normy přístrojové vybavení statistika a číselné údaje MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
An advanced surface engineering process combining micro-texture with a plasma carburising process was produced on CoCrMo femoral head, and their tribological properties were evaluated by the cutting-edge pendulum hip joint simulator coupled with thin film colorimetric interferometry. FESEM and GDOES showed that precipitation-free C S-phase with a uniform case depth of 10μm was formed across the micro-textures after duplex treatment. Hip simulator tests showed that the friction coefficient was reduced by 20% for micro-metre sized texture, and the long-term tribological property of microtexture was enhanced by the C-supersaturated crystalline microstructure formed on the surface of duplex treated CoCrMo, thereby enhancing biotribological durability significantly. In-situ colorimetric interferometry confirmed that the maximum film thickness around texture area was 530nm, indicating that the additional lubricant during sliding motion might provide exceptional bearing life.
At ecosystems level, environmental parameters such as temperature, pH, dissolved oxygen concentration and intensity of UV radiation (UVR) have an important role on the efficiency of organisms' physiological and behavioral performances and consequently on the capacity of response to contaminants. Insignificant alterations of these parameters may compromise this response. In addition, these parameters can additionally alter chemical compounds by inducing their degradation, producing thereafter other metabolites. Understanding the combined effects of chemicals and environmental parameters is absolutely necessary for an adequate prediction of risk in aquatic environments. According to this scenario, this work aims at studying the combined toxicity of UVR and three xenobiotics: the biocide triclosan (TCS), the metal chromium (as potassium dichromate, PD) and the fungicide prochloraz (PCZ). To achieve this goal zebrafish (Danio rerio) embryos (3h post fertilization (hpf)) were exposed to several concentrations of each chemical combined with different UV intensities; mortality and eggs were recorded every 24h for the all test duration (96 h). Results showed different response patterns depending on the toxicant, stress levels and duration of exposure. The combination of UVR and TCS indicated a dose ratio deviation where synergism was observed when UVR was the dominant stressor (day 2). The combination of UVR and PD presented a dose level dependency at day 3 indicating antagonism at low stress levels, changing with time where at day 4, a dose ratio deviation showed statistically that synergism occurred at higher PD concentrations. Finally, UVR combined with PCZ indicated a dose ratio at day 3 and dose level deviation at day 4 of exposure, suggesting a synergistic response when PCZ is the dominant stressor in the combination. The obtained results in this study highlighted the importance of taking into account the possible interaction of stressors and time of exposure to better predict environmental risk.
- MeSH
- antiinfekční látky lokální toxicita MeSH
- chemické látky znečišťující vodu toxicita MeSH
- dánio pruhované MeSH
- dvojchroman draselný toxicita MeSH
- embryo nesavčí účinky léků účinky záření MeSH
- fungicidy průmyslové toxicita MeSH
- imidazoly toxicita MeSH
- triclosan toxicita MeSH
- ultrafialové záření * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
