RESUMEN
Metagenomics is a helpful tool for the analysis of unculturable organisms and viruses. Viruses that target bacteria and archaea play important roles in the microbial diversity of various ecosystems. Here we show that Methanosarcina virus MV (MetMV), the second Methanosarcina sp. virus with a completely determined genome, is characteristic of hydrocarbon pollution in environmental (soil and water) samples. It was highly abundant in Hungarian hydrocarbon polluted samples and its genome was also present in the NCBI SRA database containing reads from hydrocarbon polluted samples collected in Canada, indicating the stability of its niche and the marker feature of this virus. MetMV, as the only currently identified marker virus for pollution in environmental samples, could contribute to the understanding of the complicated network of prokaryotes and their viruses driving the decomposition of environmental pollutants.
Asunto(s)
Archaea/virología , Virus de Archaea/aislamiento & purificación , Contaminación Ambiental/análisis , Hidrocarburos/análisis , Archaea/aislamiento & purificación , Virus de Archaea/genética , Canadá , ADN Viral/química , ADN Viral/metabolismo , Genoma Viral , Hungría , Microbiología del Suelo , Microbiología del AguaRESUMEN
We studied the effect of a multilevel presence of carbon-based reinforcements-a combination of conventional load-bearing unidirectional carbon fiber (CF) with multiwalled carbon nanotubes (CNT) and conductive CNT-containing nonwoven carbon nanofabric (CNF(CNT))-on the fire performance, thermal conductivity, and mechanical properties of reference and flame-retarded epoxy resin (EP) composites. The inclusion of carbon fibers and flame retardant reduced the peak heat release rate (pHRR) of the epoxy resins. The extent to which the nanoreinforcements reduced the pHRR depended on their influence on thermal conductivity. Specifically, high thermal conductivity is advantageous at the early stages of degradation, but after ignition it may lead to more intensive degradation and a higher pHRR; especially in the reference samples without flame retardant. The lowest pHRR (130 kW/m²) and self-extinguishing V-0 UL-94 rating was achieved in the flame-retarded composite containing all three levels of carbon reinforcement (EP + CNF(CNT) + CNT + CF FR). The plasticizing effect of the liquid flame retardant impaired both the tensile and flexural properties; however, it significantly enhanced the impact resistance of the epoxy resin and its composites.
RESUMEN
In the present study genotoxicological and immunotoxicological follow-up investigations were made on 811 donors including 94 unexposed controls and 717 nurses with various working conditions from different hospitals (The Hungarian Nurse Study). The nurses were exposed to different chemicals: cytostatic drugs, anesthetic, and sterilizing gases, such as ethylene oxide (ETO) and formaldehyde. The measured biomarkers were: clinical laboratory routine tests, completed with genotoxicological (chromosome aberrations [CA], sister chromatid exchange [SCE]), and immune-toxicological monitoring (ratio of lymphocyte subpopulations, lymphocyte activation markers, and leukocyte oxidative burst). The highest rate of genotoxicologically affected donors (25.4%) was found in the group of cytostatic drug-exposed nurses. Comparing geno- and immunotoxicological effect markers, we found that among genotoxicologically affected donors the frequency of helper T cell (Th) lymphocytes, the ratio of activated T and B cells increased, whereas the oxidative burst of leukocytes decreased. In hospitals with lack of protective measures increased CA yields were observed compared to those with ISO 9001 quality control or equivalent measures. Anemia, serum glucose level, thyroid dysfunctions, benign, and malignant tumors were more frequent in the exposed groups than in controls. The hygienic standard of the working environment is the basic risk factor for the vulnerability of nurses. On the basis of these results, it is suggested, that the used cytogenetic and immunological biomarkers are appropriate to detect early susceptibility to diseases. The Hungarian Nurse Study proved that the use of safety measures could protect against occupational exposure at work sites handling cytostatic drugs, anesthetic, and sterilizing gases.
Asunto(s)
Sustancias Peligrosas , Personal de Enfermería en Hospital , Citometría de Flujo , Humanos , Hungría , Sistema Inmunológico/efectos de los fármacos , Inmunofenotipificación , Mutágenos/toxicidad , Estallido RespiratorioRESUMEN
Statistical data indicate a chronic shortage of work-force due to overwork, ill health state and increased risk of chronic noninfectious diseases in Hungarian health care personnel, which needs investigations in order to decrease the risk. Nurses of oncology units, often exposed to carcinogens when preparing and handling cytostatic drugs, are especially at high risk. In the present publication we report a complex clinical, geno- and immunotoxicology risk assessment of altogether 500 nurses, performed during the last 10 years at various oncology units in Hungary. The obtained results indicate that the health status of nurses at oncology units is better than the Hungarian average, especially of hypertonia and type II diabetes. However, the prevalence of iron deficiency anemia and different thyroid gland diseases is significantly higher than those of the controls matched for sex and age. The results suggest that iron deficiency can potentiate the resistance to insulin, i.e. the persistence of iron deficiency may increase the serum glucose levels and thus the risk of diabetes. Among the studied geno- and immunotoxicology biomarkers, the frequency of chromosome aberrations, sister chromatid exchange and B lymphocytes was significantly increased compared to the matched controls. The obtained alterations demonstrate the occupational exposure of the nurses to cytostatic drugs, thus the introduction of more strict hygienic controls and compliance with the European Union chemical safety regulations is necessary.
Asunto(s)
Anemia Ferropénica/epidemiología , Antineoplásicos/efectos adversos , Estado de Salud , Enfermeras y Enfermeros/estadística & datos numéricos , Enfermedades Profesionales/epidemiología , Exposición Profesional/efectos adversos , Enfermería Oncológica , Enfermedades de la Tiroides/epidemiología , Adulto , Anemia Ferropénica/complicaciones , Anemia Ferropénica/metabolismo , Linfocitos B , Glucemia/metabolismo , Estudios de Casos y Controles , Aberraciones Cromosómicas , Dislipidemias/epidemiología , Europa (Continente) , Femenino , Guías como Asunto , Departamentos de Hospitales , Humanos , Hungría/epidemiología , Resistencia a la Insulina , Enfermedades Profesionales/complicaciones , Enfermedades Profesionales/metabolismo , Prevalencia , Estudios Retrospectivos , Intercambio de Cromátides Hermanas , Recursos HumanosRESUMEN
Chemoprevention with chelating agent Humetta for three months was performed, due to anaemia and other haematologic disorders, immunotoxicological alterations and/or increased chromosome aberration rate among galvanisers and goldsmiths occupationally exposed to precious and heavy metals. Twenty-two of altogether 47 subjects took part voluntarily in the chemoprevention, and the rest of the subjects served as untreated controls. Complex clinical laboratory testing including detailed anamneses; genotoxicological and immunotoxicological monitoring were performed before and after administration of chemopreventive agent. After chemoprevention a significant improvement was observed in anaemia and serum glucose levels, while a less marked improvement was found in serum cholesterol levels and liver functions. Altered chromosome aberration and apoptotic cell fraction also tended to normalise after treatment. Immunological parameters were not affected by the treatment. The obtained results may suggest that chemoprevention with chelating agents as Humetta can help in the prevention of harmful effects of occupational exposures to metals.