RESUMEN
Earthworms are affected by physical stress, like injury, and by exposure to xenobiotics, such as the toxic metal cadmium (Cd), which enters the environment mainly through industry and agriculture. The stress response to the single and the combination of both stressors was examined in regenerative and unharmed tissue of Lumbricus terrestris to reveal if the stress response to a natural insult like injury (amputation) interferes with Cd detoxification mechanisms. We characterized the roles of metallothionein 1 (MT1) and MT2 isoforms, heat shock protein 70 as well as immune biomarkers such as the toll-like receptors (TLR) single cysteine cluster TLR and multiple cysteine cluster TLR. The role of the activated transcription factors (ATFs) ATF2, ATF7, and the cAMP responsive element binding protein as putative regulatory intersection as well as a stress-dependent change of the essential trace elements zinc and calcium was analyzed. Phosphorylated AMP activated protein kinase, the cellular energy sensor, was measured to explore the energy demand, while the energy status was determined by detecting carbohydrate and protein levels. Taken together, we were able to show that injury rather than Cd is the driving force that separates the four treatment groups - Control, Cd exposure, Injury, Cd exposure and injury. Interestingly, we found that gene expression differed regarding the tissue section that was analyzed and we hypothesize that this is due to the migration of coelomocytes, earthworm immune cells, that take over a key role in protecting the organism from a variety of environmental challenges. Surprisingly, we discovered a role for MT1 in the response to multiple stressors and an isoform-specific function for the two newly characterized TLRs. In conclusion, we gathered novel information on the relation of innate immunity, wound healing, and Cd detoxification mechanisms in earthworms.
Asunto(s)
Cadmio , Oligoquetos , Animales , Cadmio/toxicidad , Cisteína , Zinc/metabolismo , Receptores Toll-Like/metabolismo , Cicatrización de HeridasRESUMEN
Earthworms are well-established model organisms for testing the effects of heavy metal pollution. How DNA methylation affects cadmium (Cd) detoxification processes such as the expression of metallothionein 2 (MT2), however, is largely unknown. We therefore exposed Lumbricus terrestris to 200 mg concentrations of Cd and 5-aza-2'-deoxycytidine (Aza), a demethylating agent, and sampled tissue and coelomocytes, cells of the innate immune system, for 48 h. MT2 transcription significantly increased in the Cd- and Cd-Aza-treated groups. In tissue samples, a significant decrease in MT2 in the Aza-treated group was detected, showing that Aza treatment inhibits basal MT2 gene activity but has no effect on Cd-induced MT2 levels. Although Cd repressed the gene expression of DNA-(cytosine-5)-methyltransferase-1 (DNMT1), which is responsible for maintaining DNA methylation, DNMT activity was unchanged, meaning that methylation maintenance was not affected in coelomocytes. The treatment did not influence DNMT3, which mediates de novo methylation, TET gene expression, which orchestrates demethylation, and global levels of hydroxymethylcytosine (5hmC), a product of the demethylation process. Taken together, this study indicates that Aza inhibits basal gene activity, in contrast to Cd-induced MT2 gene expression, but does not affect global DNA methylation. We therefore conclude that Cd detoxification based on the induction of MT2 does not relate to DNA methylation changes.
RESUMEN
DNA hypermethylation caused by environmental pollutants like cadmium (Cd) has already been demonstrated in many invertebrates, including earthworms. However, the exact epigenetic mechanisms that drive this hypermethylation are largely unknown and even basic DNA methylation and demethylation processes are hardly characterized. Therefore, we used an important bioindicator, the earthworm Lumbricus terrestris, as a model organism to determine time- and dose-dependent effects of Cd on global and gene-specific DNA methylation and its underlying mechanisms. We revealed Cd-induced adenine and cytosine hypermethylation using specific antibodies in dot blots and found that the methylation level of adenine compared to cytosine changed even to a bigger extent. However, the levels of hydroxymethylated cytosine did not differ between treatment groups. General methylation and demethylation components like methyltransferases (DNMT1 and 3), and ten-eleven translocation (TET) genes were confirmed in L. terrestris by quantitative RealTime PCR. However, neither gene expression, nor DNMT and TET enzyme activity showed significant differences in the Cd exposure groups. Using bisulfite conversion and sequencing, gene body methylation (gbm) of metallothionein 2 (MT2), one of the most important detoxification proteins, was characterized. Cd-dependent changes in MT2 gbm could, however, not be correlated to MT2 gene activity evaluated by quantitative RealTime PCR. Future directions as well as missing links are discussed in the present study hinting towards the importance of studying epigenetic marks and mechanistic insights in a broad variety of species to deepen our knowledge on the effects of changing environmental conditions.
Asunto(s)
Metilación de ADN , Oligoquetos , Animales , Cadmio/metabolismo , Cadmio/toxicidad , Epigénesis Genética , Metalotioneína/genética , Oligoquetos/genética , Oligoquetos/metabolismoRESUMEN
The enormous progress made in recent years in the field of information and communication technology and also in sensor and computer technology has affected numerous fields of medicine and is capable of inducing even radical changes in diagnostic and therapeutic processes. This is particularly true for cardiology, where, for example, telemetric monitoring of cardiac and circulatory functions has been in use for many years. Nevertheless, broad application of newer telemedical processes has not yet been achieved to the extent one would expect from the encouraging results of numerous clinical studies in this field and the state of the art of the underlying technology. In the present paper, the Working Group on Rhythmology of the Austrian Cardiological Society aims to provoke a critical discussion of the digital change in cardiology and to make recommendations for the implementation of those telemedical processes that have been shown to exert positive effects on a wide variety of medical and economic parameters. The greatest benefit of telecardiological applications is certainly to be found in the long-term care of patients with chronic cardiovascular diseases. Accordingly, follow-up care of patients with cardiological rhythm implants, management of chronic heart failure and secondary prevention following an acute cardiac event during rehabilitation are currently the most important fields of application. Telemedicine is intended to enable high-quality and cost-efficient care for an increasing number of patients, whose care poses one of the greatest challenges to our healthcare system. Not least of all, telemedicine should make a decisive contribution to improving the quality of life of this segment of the population by favorably influencing mortality, morbidity and hospitalization as well as the patient's contribution to treatment.
Asunto(s)
Cardiología , Insuficiencia Cardíaca , Telemedicina , Austria , Humanos , Calidad de VidaRESUMEN
A short review of legal aspects of organ transplantation. The influence of type of consent and the family attitude on organ donation rate in all European countries. A special attention is given to the legal and ethical aspects of living organ and tissue transplantation.
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Familia , Derechos Humanos , Trasplante de Órganos/legislación & jurisprudencia , Austria , Cadáver , Derechos Humanos/legislación & jurisprudencia , Humanos , Consentimiento Informado/legislación & jurisprudencia , Internacionalidad , Donadores Vivos/legislación & jurisprudencia , Consentimiento Presumido/legislación & jurisprudencia , Obtención de Tejidos y Órganos/legislación & jurisprudenciaRESUMEN
In Austria the vaccination coverage among health care workers (HCW) - particularly among hospital personnel - is not sufficient. This is of specific concern, because not only the individual protection but also the prevention of disease transmission of vaccine preventable diseases between HCW and patients needs to be guaranteed. Particularly immunosuppressed patients, who are at higher risk for morbidity and mortality due to certain infections, but cannot be vaccination themselves, must be able to rely on herd protection, i.e. not being infected by surrounding/caring persons. The following publication provides for the first time detailed guidelines for vaccination programs for HCWs in Austria, including personnel within hospitals, medical institutions and laboratories, as well as Medical Universities including students. Moreover, these guidelines are also recommended to medical personnel in outpatient clinics, social service institutions and medical practices. Additionally to the vaccination schedules this publication also includes a chapter on ethical as well as legal background underlying these recommendations.
Asunto(s)
Personal de Salud , Enfermedades Profesionales/prevención & control , Guías de Práctica Clínica como Asunto , Vacunación/normas , Virosis/prevención & control , Austria , HumanosRESUMEN
PURPOSE: Precise and comprehensive analysis of neuroblastoma genetics is essential for accurate risk evaluation and only pangenomic/multilocus approaches fulfill the present-day requirements. We present the establishment and validation of the PCR-based multiplex ligation-dependent probe amplification (MLPA) technique for neuroblastoma. EXPERIMENTAL DESIGN: A neuroblastoma-specific MLPA kit was designed by the SIOP Europe Neuroblastoma Biology Committee in cooperation with MRC-Holland. The contained target sequences cover 19 chromosomal arms and reference loci. Validation was performed by single locus and pangenomic techniques (n = 174). Dilution experiments for determination of minimal tumor cell percentage were performed and testing of reproducibility was checked by interlaboratory testing (n = 15). Further 156 neuroblastomas were used for establishing the amplification cutoff level. RESULTS: The MLPA technique was tested in 310 neuroblastomas and 8 neuroblastoma cell lines (including validation and amplification cutoff level testing). Intertechnique validation showed a high concordance rate (99.5%). Interlaboratory MLPA testing (κ = 0.95, P < 0.01) revealed 7 discrepant of 1,490 results (0.5%). Validation by pangenomic techniques showed a single discordance of 190 consensus results (0.5%). The test results led to formulation of interpretation standards and to a kit revision. The minimal tumor cell percentage was fixed at 60%. CONCLUSIONS: The recently designed neuroblastoma-specific MLPA kit covers all chromosomal regions demanded by the International Neuroblastoma Risk Group for therapy stratification and includes all hitherto described genetic loci of prognostic interest for future studies and can be modified or extended at any time. Moreover, the technique is cost effective, reliable, and robust with a high interlaboratory and intertechnique concordance.