Cancer incidence in Czech black coal miners in association with coalworkers’ pneumoconiosis

Objective: The aim of the study was comparison of cancer incidence risk of lungs, stomach, colon, bladder and kidneys from ex-miners of black coal mines and the general male population of the Czech Republic. Materials and methods: The analysis was conducted in two cohorts of ex-miners according to the presence of coalworkers’ pneumoconiosis (CWP). The first cohort included the miners without CWP (N = 6705), and the second cohort included the miners who were compensated for CWP (N = 2158). Personal and occupational data was merged with the data in the National Population Register and the National Oncological Register for the period from 1992 to 2006. Cancer risk in miners in comparison to the general male population of the Czech Republic was evaluated by SIR (Standardized Incidence Ratio) and 95% confidence interval (CI). Results: About twice as high risk of lung cancer was found in miners with CWP (SIR = 2.21; 95% CI: 1.75–2.76). Lung cancer risk correlated with the severity of CWP (simple CWP SIR=1.96; 95% CI: 1.48–2.56, progressive massive fibrosis SIR = 4.29; 95% CI: 2.09–7.87). No increased risk of lung cancer was found in ex-miners without CWP. The risk of malignant neoplasm at the other selected sites was comparable with the risk in the general male population of the Czech Republic. Conclusions: This study found increased lung cancer risk in coal miners with CWP, but not in those without CWP, comparing with the general population. These results served as the basis for the inclusion of lung cancer in association with CWP into a new Czech list of occupational diseases

Health status and physical fitness of mines rescue brigadesmen

Objectives: The aim of the study was to assess health status of regular and part-time mines rescue brigadesmen. Material and Methods: A group of 685 mines rescue brigadesmen was examined within the preventive testing – a basic internal, biochemistry and anthropometric examination, physical fitness testing. Results: The average age of the subjects was 41.96±7.18 years, the average exposure in mining was 20±8.1 years, out of that 11.95±7.85 years as mines rescue brigadesmen. Elevated levels of total serum cholesterol (T-CH) and low-density lipoprotein cholesterol (LDL-CH) were found in over 1/2 of the subjects. Systolic hypertension (systolic blood pressure (SBP) ≥ 140 mm Hg) was confirmed in 34%, overweight (body mass index (BMI) ≥ 25) in 62.3% and obesity (BMI ≥ 30) in 20.4% of the examined mines rescue brigadesmen. The metabolic syndrome was found in 15.2% of persons. The highest physical fitness was found in mines rescue brigadesmen and the lowest in mine officers. Limit values of maximum oxygen uptake (VO2 max/kg) determined by the management of the mine rescue station were not reached by every 3rd of all mines rescue brigadesmen. Compared with the control group of the Czech and Slovak population, the rescuers are taller, have greater BMI, higher percentage of body fat in all age categories and proportionally to that they achieve a higher maximum minute oxygen uptake; however, in relative values per kg of body weight their physical fitness is practically the same as that of the controls. Conclusions: The prevalence of risk factors of cardiovascular diseases and VO2 max/kg in the group of the mines rescue brigadesmen is comparable with that in the general untrained Czech population

Health status and physical fitness of mines rescue brigadesmen

Objectives: The aim of the study was to assess health status of regular and part-time mines rescue brigadesmen. Material and Methods: A group of 685 mines rescue brigadesmen was examined within the preventive testing – a basic internal, biochemistry and anthropometric examination, physical fitness testing. Results: The average age of the subjects was 41.96±7.18 years, the average exposure in mining was 20±8.1 years, out of that 11.95±7.85 years as mines rescue brigadesmen. Elevated levels of total serum cholesterol (T-CH) and low-density lipoprotein cholesterol (LDL-CH) were found in over 1/2 of the subjects. Systolic hypertension (systolic blood pressure (SBP) ≥ 140 mm Hg) was confirmed in 34%, overweight (body mass index (BMI) ≥ 25) in 62.3% and obesity (BMI ≥ 30) in 20.4% of the examined mines rescue brigadesmen. The metabolic syndrome was found in 15.2% of persons. The highest physical fitness was found in mines rescue brigadesmen and the lowest in mine officers. Limit values of maximum oxygen uptake (VO2 max/kg) determined by the management of the mine rescue station were not reached by every 3rd of all mines rescue brigadesmen. Compared with the control group of the Czech and Slovak population, the rescuers are taller, have greater BMI, higher percentage of body fat in all age categories and proportionally to that they achieve a higher maximum minute oxygen uptake; however, in relative values per kg of body weight their physical fitness is practically the same as that of the controls. Conclusions: The prevalence of risk factors of cardiovascular diseases and VO2 max/kg in the group of the mines rescue brigadesmen is comparable with that in the general untrained Czech population

Tyčovité nanočástice maghemitu potažené silikou: Syntéza přes akaganeit, charakterizace a biologické vlastnosti

A multistep procedure, employing akaganeite FeO(OH,Cl) as a precursor, was developed for the preparation of rod-like maghemite particles for medical applications. At first, akaganeite rods with length of several hundred nm and width of approximate to 85 nm were prepared under hydrothermal conditions and were subsequently coated with mesoporous silica. Such coating enabled to maintain the shape of rods during the following steps that involved structural transformation of akaganeite to maghemite, i.e. gamma-Fe2O3. Then the original protective coating was removed by alkaline leaching, bare maghemite rods were isolated, and their structure and ferrimagnetic order were characterized by X-ray diffraction, TEM inspection, Mossbauer spectroscopy and SQUID magnetometry. The magnetization of the bare maghemite rods, that were formed by elongated clusters of approximate to 10-20 nm crystallites, made 47.0 and 41.7 Am-2/kg in magnetic field of 3 T at 5 K and 300 K, respectively. The hysteresis loops of both the bare and coated products at 300 K and ZFC/FC studies showed that the maghemite particles were largely blocked at room temperature in spite of the small size of crystallites. Finally, the particles were equipped with standard silica coating for biological studies. An evaluation of cytotoxicity of this silica-coated product was performed on two cell lines, namely A549 and MCF-7. The viability of cells incubated with particles at the concentration of 0.10, 0.21 and 0.42 mmol(Fe)/L was determined after 24 h and 48 h of incubation, and the values normalized to the viability of negative control were generally higher than 95%. Moreover, the real-time monitoring of cell adhesion, proliferation, and cytotoxicity by an xCELLigence system during 72 h of the incubation with particles revealed only some decrease of the cell index for the MCF-7 cells at the high concentration.Pro přípravu tyčovitých maghemitových částic pro lékařské aplikace byl vyvinut vícestupňový postup využívající akaganeit FeO (OH, Cl) jako prekurzor. Nejprve byly za hydrotermálních podmínek připraveny akaganeitové tyče s délkou několika stovek nm a šířkou přibližně 85 nm a následně byly potaženy mesoporézním oxidem křemičitým. Takový povlak umožnil udržet tvar tyčinek v následujících krocích, které zahrnovaly strukturální přeměnu akaganeitu na maghemit, tj. gama-Fe203. Poté byl původní ochranný povlak odstraněn alkalickým vyluhováním, byly izolovány holé maghemitové tyčinky a jejich struktura a ferrimagnetické uspořádání byly charakterizovány rentgenovou difrakcí, TEM kontrolou, Mossbauerovou spektroskopií a SQUID magnetometrií. Magnetizace holých maghemitových tyčí, které byly vytvořeny protáhlými shluky přibližně 10 až 20 nm krystalů, vytvořila 47,0 a 41,7 Am-2 / kg v magnetickém poli 3 T při 5 K a 300 K. Hysterezní smyčky holých i potažených produktů při 300 K a ZFC / FC studie ukázaly, že částice maghemitu byly z velké části blokovány při pokojové teplotě navzdory malé velikosti krystalů. Nakonec byly částice potaženy silikou pro účely biologických testů. Vyhodnocení cytotoxicity bylo provedeno na dvou buněčných liniích, konkrétně A549 a MCF-7. Viabilita buněk inkubovaných s částicemi v koncentraci 0,10, 0,21 a 0,42 mmol (Fe) / l byla stanovena po 24 hodinách a 48 hodinách a hodnoty byly vztaženy k viabilitě negativní kontroly. Viabilita byla vyšší než 95%. Kromě toho, monitorování buněčné adheze, proliferace a cytotoxicity v reálném čase pomocí systému xCELLigence po dobu 72 hodin, ukázalo pouze nepatrné snížení buněčného indexu u buněčné linie MCF-7 při vysoké koncentraci částic

Mn-Zn feritové nanočástice obalené silikou a titanem: syntéza, transverzální relaxivita a cytotoxicita

Mn-Zn ferrite nanoparticles of composition Mn0.61Zn0.42Fe1.97O4 and mean size of crystallites d(XRD) = 11 nm are synthesized under hydrothermal conditions as a single-phase product. Subsequently, two coated samples are prepared by encapsulation of the ferrite particles into silica and titania. Transmission electron microscopy confirms the core-shell structure of the products and shows that the cores are actually formed by small clusters of ferrite crystallites. Powder X-ray diffraction, combined with experimental hydrothermal treatment of the titania-coated product, demonstrates that the titania coating is amorphous but can easily be transformed into anatase. The colloidal stability of nanoparticles in water is evidenced by dynamic light scattering, and the respective hydrodynamic sizes are d(Z) = 87 and 157 nm for the silica-coated and titania-coated particles. The colloidal behavior is confirmed based on the measurements of zeta potential, whose negative values lead to strong Coulombic repulsion among coated particles. Magnetic measurements on bare and coated particles show high magnetization of Mn0.61Zn0.42Fe1.97O4 cores and superparamagnetic state at room temperature. The relaxometric study on aqueous suspensions in magnetic fields of 0.5 and 11.75 T reveals high transverse relaxivity of the samples and two distinct forms of its temperature dependence, which are analyzed with respect to the role of temperature-dependent parameters, that is, the diffusion of water and the magnetization of ferrite cores. Finally, careful evaluation of cytotoxicity of coated particles is carried out by using two different methods, namely, the determination of viability and proliferation of Jurkat cells and the real-time monitoring of attachment and proliferation of A549 cells. In the studied range of concentrations, the viability and proliferation of suspension cells are not affected, and only negligible effects are detected in the cell index of adherent cells.Mn-Zn feritové nanočástice o složení Mn0.61Zn0.42Fe1.97O4 a průměrné velikosti krystalů d(XRD) = 11 nm) byly připraveny hydrotermální syntézou. Nakonec byla podrobně vyhodnocena cytotoxicita obalených nanočástic pomocí dvou odlišných metod: pomocí stanovení viability a proliferace buněčné linie Jurkat a pomocí analýzy adheze a proliferace buněčné linie A549 v reálném čase. V rámci hodnoceného koncentračního rozsahu, nebyla ovlivněna viabilita a proliferace suspenzních buněk a pouze zanedbatelný vliv na buněčný index byl pozorován u adherentních buněk