434 resultados para Kokkonen, Jouko


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We report that three (EF0089, EF2505 and EF1896, renamed here Fss1, Fss2 and Fss3, respectively, for Enterococcus faecalis surface protein) of the recently predicted MSCRAMMs (microbial surface components recognizing adhesive matrix molecules) in E. faecalis strain V583 bind fibrinogen (Fg). Despite an absence of extensive primary sequence homology, the three proteins appear to be related structurally. Within the N-terminal regions of the three enterococcal proteins, we identified pairs of putative IgG-like modules with a high degree of predicted structural similarity to the Fg-binding N2 and N3 domains of the staphylococcal MSCRAMMs ClfA and SdrG. A second N2N3-like segment was predicted in Fss1. Far-UV circular dichroism spectroscopy revealed that all four predicted N2N3-like regions are composed mainly of beta-sheets with only a minor proportion of alpha-helices, which is characteristic of Ig-like folded domains. Three of the four identified enterococcal N2N3-like regions showed potent dose-dependent binding to Fg. However, the specificity of the Fg-binding MSCRAMMs differs, as indicated by far-Western blots, which showed that recombinant segments of the MSCRAMMs bound different Fg polypeptide chains. Enterococci grown in serum-supplemented broth adhere to Fg-coated surfaces, and inactivation in strain OG1RF of the gene encoding Fss2 resulted in reduced adherence, whilst complementation of the mutant restored full Fg adherence. Thus, E. faecalis contains a family of MSCRAMMs that structurally and functionally resemble the Fg-binding MSCRAMMs of staphylococci.

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Enterococcus faecium has recently emerged as an important cause of nosocomial infections. We previously identified 15 predicted surface proteins with characteristics of MSCRAMMs and/or pili and demonstrated that their genes were frequently present in 30 clinical E. faecium isolates studied; one of these, acm, has been studied in further detail. To determine the prevalence of the other 14 genes among various E. faecium populations, we have now assessed 433 E. faecium isolates, including 264 isolates from human clinical infections, 69 isolates from stools of hospitalized patients, 70 isolates from stools of community volunteers, and 30 isolates from animal-related sources. A variable distribution of the 14 genes was detected, with their presence ranging from 51% to 98% of isolates. While 81% of clinical isolates carried 13 or 14 of the 14 genes tested, none of the community group isolates and only 13% of animal isolates carried 13 or 14 genes. The presence of these genes was most frequent in endocarditis isolates, with 11 genes present in all isolates, followed by isolates from other clinical sources. The number of genes significantly associated with clinical versus fecal or animal origin (P = 0.04 to <0.0001) varied from 10 to 13, depending on whether comparisons were made against individual clinical subgroups (endocarditis, blood, and other clinical isolates) or against all clinical isolates combined as one group. The strong association of these genes with clinical isolates raises the possibility that their preservation/acquisition has favored the adaptation of E. faecium to nosocomial environments and/or patients.

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Increasing multidrug resistance in Enterococcus faecalis, a nosocomial opportunist and common cause of bacterial endocarditis, emphasizes the need for alternative therapeutic approaches such as immunotherapy or immunoprophylaxis. In an earlier study, we demonstrated the presence of antibodies in E. faecalis endocarditis patient sera to recombinant forms of 9 E. faecalis cell wall-anchored proteins; of these, we have now characterized an in vivo-expressed locus of 3 genes and an associated sortase gene (encoding sortase C; SrtC). Here, using mutation analyses and complementation, we demonstrated that both the ebp (encoding endocarditis and biofilm-associated pili) operon and srtC are important for biofilm production of E. faecalis strain OG1RF. In addition, immunogold electron microscopy using antisera against EbpA-EbpC proteins as well as patient serum demonstrated that E. faecalis produces pleomorphic surface pili. Assembly of pili and their cell wall attachment appeared to occur via a mechanism of cross-linking of the Ebp proteins by the designated SrtC. Importantly, a nonpiliated, allelic replacement mutant was significantly attenuated in an endocarditis model. These biologically important surface pili, which are antigenic in humans during endocarditis and encoded by a ubiquitous E. faecalis operon, may be a useful immunotarget for studies aimed at prevention and/or treatment of this pathogen.

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Strains of Enterococcus faecium express a cell wall-anchored protein, Acm, which mediates adherence to collagen. Here, we (i) identify the minimal and high-affinity binding subsegments of Acm and (ii) show that anti-Acm immunoglobulin Gs (IgGs) purified against these subsegments reduced E. faecium TX2535 strain collagen adherence up to 73 and 50%, respectively, significantly more than the total IgGs against the full-length Acm A domain (28%) (P < 0.0001). Blocking Acm adherence with functional subsegment-specific antibodies raises the possibility of their use as therapeutic or prophylactic agents.

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The innate immune system recognizes microbial features leading to the activation of the adaptive immune system. The role of Toll-like receptor 9 (TLR9) is to recognize microbial DNA. In addition to immune cells, TLR9 is widely expressed in breast cancer in addition to other cancers. Breast cancer is the most common cancer in women, affecting approximately one in eight in industrialized countries. In the clinical setting, breast cancer is divided into three clinical subtypes with type-specific treatments. These subtypes are estrogen receptor (ER)-positive, HER2-positive and triple-negative (TNBC) breast cancer. TNBC is the most aggressive subtype that can be further divided into several subtypes. TNBC tumors lack ER, progesterone receptor and HER2 receptor. Therefore, the current clinically used targeted therapies are not suitable for TNBC treatment as TNBC is a collection of diseases rather than one entity. Some TNBC patients are cured with standard chemotherapy, while others rapidly die due to the disease. There are no clinically used iomarkers which would help in predicting which patients respond to chemotherapy. During this thesis project, we discovered a novel good-prognosis TNBC subtype. These tumors have high TLR9 expression levels. Our findings suggest that TLR9 screening in TNBC patient populations might help to identify the patients that are at the highest risk regarding a relapse. To gain better understanding on the role of TLR9 in TNBC, we developed an animal model which mimicks this disease. We discovered that suppression of TLR9 expression in TNBC cells increases their invasive properties in hypoxia. In line with the clinical findings, TNBC cells with low TLR9 expression also formed more aggressive tumors in vivo. TLR9 expression did not, however, affect TNBC tumor responses to doxorubicin. Our results suggest that tumor TLR9 expression may affect chemotherapyrelated immune responses, however, this requires further investigation. Our other findings revealed that DNA released by chemotherapy-killed cells induces TLR9-mediated invasion in living cancer cells. Normally, extracellular self-DNA is degraded by enzymes, but during massive cell death, for example during chemotherapy, the degradation machinery may be exhausted and self-DNA is taken up into living cells activating TLR9. We also discovered that the malaria drug chloroquine, an inhibitor of autophagy and TLR9 signalling does not inhibit TNBC growth in vivo, independently of the TLR9 status. Finally, we found that ERα as well as the sex hormones estrogen and testosterone regulate TLR9 expression and activity in breast cancer cells in vitro. As a conclusion, we suggest that TLR9 is a potential biomarker in TNBC. ------- Sisäsyntyisen immuniteetin tehtävä on tunnistaa mikrobien molekyylirakenteita, mikä saa aikaan adaptiivisen immuunijärjestelmän aktivoitumisen. Tollin kaltainen reseptori 9 (TLR9) on dna:ta tunnistava sisäsyntyisen immuniteetin reseptori, jota ilmennetään myös useissa syövissä, kuten rintasyövässä. Rintasyöpä on naisten yleisin syöpä, johon joka kahdeksas nainen sairastuu elämänsä aikana. Kliinisesti rintasyöpä jaotellaan kolmeen alatyyppiin, joista kolmoisnegatiivinen rintasyöpä on aggressiivisin. Tämän tyypin syövät eivät ilmennä hormonireseptoreja (estrogeeni- ja progesteronireseptori) tai HER2-reseptoria. Tästä johtuen kolmoisnegatiivisten potilaiden hoitoon ei voida käyttää rintasyövän nykyisten hoitosuositusten mukaisia täsmähoitoja. Kolmoisnegatiivinen rintasyöpä ei kuitenkaan ole yksi sairaus, koska molekyylitasolla sen on osoitettu koostuvan lukuisista, biologialtaan erilaisista syöpämuodoista. Tällä hetkellä kliinisessä käytössä ei ole biomarkkeria, jonka avulla kolmoisnegatiivisen rintasyövän alatyypit voisi erottaa toisistaan. Löysimme uuden kolmoisnegatiivisen syövän alatyypin, joka ilmentää vain vähän TLR9-proteiinia. Tällä alatyypillä on erittäin huono ennuste ja tulostemme perusteella TRL9-tason selvittäminen voisi seuloa huonoennusteiset syövät kolmoisnegatiivisten syöpien joukosta. Kehitimme eläinmallin, jolla voidaan tutkia matalan ja korkean TLR9-tason vaikutuksia kolmoisnegatiivisten kasvainten hoitovasteeseen. Toinen löytömme oli, että kemoterapialla tapettujen syöpäsolujen dna saa aikaan elävien syöpäsolujen TLR9-välitteistä invaasiota. Normaalisti entsyymit hajoittavat yksilön oman solunulkoisen dna:n. Erikoistilanteissa, kuten syöpähoitojen yhteydessä, jolloin solukuolema on massiivista, elimistön oma koneisto ei ehdi tuhoamaan solunulkoista dna:ta ja sitä voi kertyä eläviin soluihin, joissa se aktivoi TLR9:n. Kolmanneksi havaitsimme, että malarialääke klorokiini, joka estää TLR9:n toimintaa ja jolla on syövänvastaisia vaikutuksia soluviljelyolosuhteissa, ei estänyt TLR9-positiivisten tai TLR9-negatiivisten kasvainten kasvua käyttämässämme eläinmallissa. Neljänneksi soluviljelykokeittemme tulokset osoittivat, että sukupuolihormonit estrogeeni ja testosteroni sekä estrogeenireseptori osallistuvat TLR9:n ilmentymisen ja aktiivisuuden säätelyyn. Tuloksemme osoittavat, että TLR9 potentiaalinen biomarkkeri kolmoisnegatiivisessa rintasyövässä.

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Suomenlahden alueen alusöljy- ja aluskemikaalivahinkojen torjunnan yhteistoimintasuunnitelma on laadittu Uudenmaan ELYkeskuksen johdolla eri viranomaisten yhteistyönä. Suunnitelma perustuu öljyvahinkojen torjuntalain 13. §:ään. Suunnitelman tarkoituksena on varmistaa torjuntatöiden nopea käynnistyminen ja laadukas toteuttaminen viranomaisten yhteistoimin kaikissa toiminta-alueen vahinkotilanteissa. Suunnitelmassa on esitetty Suomenlahden alueen erityispiirteitä sekä eri viranomaisten ja muiden torjuntaan osallistuvien tehtäviä ja resursseja. Suunnitelmassa kuvataan torjuntatyön eri vaiheita ja toimenpiteitä. Torjuntajärjestelyt perustuvat ensisijaisesti pelastustoimen, muiden torjuntaviranomaisten sekä virka-apuviranomaisten yhteistoimintaan. Suurten merialueella tapahtuvien vahinkojen torjunnassa tarvitaan aina resursseja yhteistoiminta-alueen ulkopuolelta. Yhteistyötä ja koordinaatiota yhteistoiminta-alueiden välillä ja valtakunnallisella tasolla tulee kehittää. Kokonaisuus muun muassa päivitettyine uhkakuvineen tulee laatia valtakunnallisen torjuntastrategian muotoon. Suunnitelman laatimisen aikana kirjattujen kehittämistarpeiden toimenpanoa pyritään edistämään lähivuosina.

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Globalization has increasingly brought permanent contact with people whose cultural background is different from what many would consider their ‘own’ culture. The area of intercultural management is of critical interest due to the impact of increased European and global migration, which has required health and social care leaders and managers to develop competency to respond to the diversity and changing needs of their workforce and service users. The communities within the European Union are now often characterised by significant diversity whether at cultural, social, or psychological levels. The purpose of this chapter is to enable health and social care practitioners to assume a clinical/ professional leadership role in quality intercultural management in the health and social care sector. This chapter will focus on developing health and social care practitioners’ knowledge and understanding in the area of intercultural management within contemporary health and social care organisations. It will focus on the critical application of knowledge to practice through the provision of underpinning knowledge, understanding and debates surrounding contemporary issues and practices in the areas of intercultural management. Many practitioners accessing this information may already work in the heath/social sector and this critical focus on intercultural and diversity management has the potential to improve the quality in health and social care services through the critical application to practice.