100 research outputs found
Controlled Chaos of Polymorphic Mucins in a Metazoan Parasite (Schistosoma mansoni) Interacting with Its Invertebrate Host (Biomphalaria glabrata)
Invertebrates were long thought to possess only a simple, effective and hence non-adaptive defence system against microbial and parasitic attacks. However, recent studies have shown that invertebrate immunity also relies on immune receptors that diversify (e.g. in echinoderms, insects and mollusks (Biomphalaria glabrata)). Apparently, individual or population-based polymorphism-generating mechanisms exists that permit the survival of invertebrate species exposed to parasites. Consequently, the generally accepted arms race hypothesis predicts that molecular diversity and polymorphism also exist in parasites of invertebrates. We investigated the diversity and polymorphism of parasite molecules (Schistosoma mansoni Polymorphic Mucins, SmPoMucs) that are key factors for the compatibility of schistosomes interacting with their host, the mollusc Biomphalaria glabrata. We have elucidated the complex cascade of mechanisms acting both at the genomic level and during expression that confer polymorphism to SmPoMuc. We show that SmPoMuc is coded by a multi-gene family whose members frequently recombine. We show that these genes are transcribed in an individual-specific manner, and that for each gene, multiple splice variants exist. Finally, we reveal the impact of this polymorphism on the SmPoMuc glycosylation status. Our data support the view that S. mansoni has evolved a complex hierarchical system that efficiently generates a high degree of polymorphismâa âcontrolled chaosââbased on a relatively low number of genes. This contrasts with protozoan parasites that generate antigenic variation from large sets of genes such as Trypanosoma cruzi, Trypanosoma brucei and Plasmodium falciparum. Our data support the view that the interaction between parasites and their invertebrate hosts are far more complex than previously thought. While most studies in this matter have focused on invertebrate host diversification, we clearly show that diversifying mechanisms also exist on the parasite side of the interaction. Our findings shed new light on how and why invertebrate immunity develops
Elements of the material working environment in the process of assessing the threat of the underground workplace
Diagnostyka stanu bezpieczeĆstwa pracy coraz czÄĆciej, obok tradycyjnych metod i technik ukierunkowanych na badanie przyczyn i okolicznoĆci wypadkĂłw juĆŒ zaistniaĆych stosuje metody wyprzedzajÄ
ce skierowane na badaniu potencjaĆu zagroĆŒeniowego. W artykule umĂłwiono metodÄ porĂłwnawczo-jakoĆciowÄ
na przykĆadzie stanowiska pracy: obsĆuga przenoĆnika taĆmowego w wyrobisku podziemnym.Framework of diagnostics of the occupational safety state more and more often apart from the traditional methods and techniques oriented on investigations regarding the reasons and circumstances of accidents that already took place prospective advanced methods and techniques are applied, oriented on the examination of the hazard potential. The article discusses, for example, the workplace: handling a conveyor belt in an underground mine
Polish steam coal market index
Podstawowym noĆnikiem energii w polskiej gospodarce jest wÄgiel kamienny. Ze wzglÄdu na tak wysoki udziaĆ w bilansie energetycznym waĆŒnym jest zagwarantowanie stabilnych i przewidywalnych cen tego surowca. Dlatego teĆŒ dla rynku wewnÄtrznego Agencja Rozwoju PrzemysĆu S.A. i Towarowa GieĆda Energii S.A. postanowiĆy utworzyÄ Polskie Indeksy Rynku WÄgla Energetycznego PSCMI. W artykule omĂłwiono indeksy dla wÄgla sprzedawanego na krajowym rynku dla energetyki (PSCMI 1) i ciepĆownictwa (PSCMI 2). OmĂłwiono rĂłwnieĆŒ trendy cenowe i analizÄ zmian cen dla tych indeksĂłw.Coal is the primary energy carrier in the Polish economy. Due to such a high share of the energy balance, it is important to guarantee stable and predictable prices of this raw material. Therefore, for the internal market, the Industrial Development Agency S.A. And Towarowa GieĆda Energii S.A. They decided to set up the Polish Index of PSCMI Energy Market. The indices for carbon sold on the domestic market for energy (PSCMI 1) and district heating (PSCMI 2) are discussed. Price trends and price developments for these indices are also discussed
Reply to: "arginase 1: a potential marker of a common pattern of liver steatosis in HCV and NAFLD children"
International audienc
Anti-apoptotic activity of low levels of wild-type p53.
Induction of apoptosis is a function of both an external stimulus and the physiology of the cell, which includes the expression of multiple oncogenes and tumor suppressors. Here we have studied the apoptotic response of immortalized mouse fibroblasts to serum withdrawal. We show that, in addition to the p53-independent apoptosis observed in p53- cells, overexpression of wild-type p53 tumor suppressor results in a high rate of programmed cell death. However, physiological range, low levels of the p53 protein protect fibroblasts from induction of apoptosis. Our results indicate that, as a function of its dose, the wild-type p53 can either protect from death or promote apoptosis. This new, anti-apoptotic, activity of p53 may have implications for the understanding of the role played by p53 in embryonic development as well as in initial stages of oncogenesis
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