26 research outputs found
Liver-Derived IGF-I Regulates Mean Life Span in Mice
Background: Transgenic mice with low levels of global insulin-like growth factor-I (IGF-I) throughout their life span, including pre- and postnatal development, have increased longevity. This study investigated whether specific deficiency of liver-derived, endocrine IGF-I is of importance for life span. Methods and Findings: Serum IGF-I was reduced by approximately 80 % in mice with adult, liver-specific IGF-I inactivation (LI-IGF-I-/- mice), and body weight decreased due to reduced body fat. The mean life span of LI-IGF-I-/- mice (n = 84) increased 10 % vs. control mice (n = 137) (Coxâs test, p,0.01), mainly due to increased life span (16%) of female mice [LI-IGF-I-/- mice (n = 31): 26.761.1 vs. control (n = 67): 23.060.7 months, p,0.001]. Male LI-IGF-I-/- mice showed only a tendency for increased longevity (p = 0.10). Energy expenditure, measured as oxygen consumption during and after submaximal exercise, was increased in the LI-IGF-I-/- mice. Moreover, microarray and RT-PCR analyses showed consistent regulation of three genes (heat shock protein 1A and 1B and connective tissue growth factor) in several body organs in the LI-IGF-I-/- mice. Conclusions: Adult inactivation of liver-derived, endocrine IGF-I resulted in moderately increased mean life span. Body weight and body fat decreased in LI-IGF-I-/- mice, possibly due to increased energy expenditure during exercise. Genes earlier reported to modulate stress response and collagen aging showed consistent regulation, providing mechanisms tha
Activation of neutrophils by mycobacteria and mycobacterial components
The genus Mycobacterium includes free-living saprophytes, opportunists, and human pathogens.Mycobacterium tuberculosis, the organism causing tuberculosis, as well as other pathogenicmycobacteria can survive and multiply inside phagocytic cells, but the underlying mechanisms areonly partly understood. The innate immune response to mycobacterial infections is predominantlymediated and regulated by activated macrophages. Neutrophils are, however, an important part of thefirst-line of defence against most microorganisms. Protection is achieved either by direct killing of thebacteria or through production of cytokines. The neutrophils might therefor be important also in thedefence against mycobacteria.The aim of this study was to investigate the neutrophil responses induced by cell wall componentsand whole cells representing mycobacteria that differ concerning virulence. The study was focused onthe capability of mycobacterial cell wall structures or whole mycobacteria cells to induce an oxidativeresponse and production of cytokines.Phenolic glycolipids (PGLs) from M. kansasii and M. tuberculosis induced an oxidative responsein human neutrophils, which PGLs from M. marinum and M. bovis BCG were unable to do. Thecarbohydrate part was shown to be of crucial importance for the interaction. In contrast, the cell wallcomponent lipoarabinomannan (LAM) was unable to bring about a significant oxidative response inneutrophils, but induced a primed state in the cells. The primed state was accompanied by granulemobilisation, shown as an increased exposure of receptors as well as a release of granule contents.Neutrophils were also exposed to whole living mycobacterial cells and it was shown that M.tuberculosis, the opportunistic M. avium, and the non-pathogenic M. smegmatis all induced aproduction/release of TNF-a, IL-6, and IL-8 from human neutrophils. The amounts induced by M.tuberculosis were, however, lower than for the other non-pathogenic bacteria. The inefficientinduction of these cytokines in neutrophils could be a mechanism for the tubercle bacilli to persist,while the non-pathogenic mycobacteria are effectively eliminated.In conclusion, mycobacteria and mycobacterial components do affects neutrophils. The oxygenradicals produced and the cytokines released might be important parts in the early defence againstmycobacterial infections
Adhesion of Streptococcus mitis and Actinomyces oris in co-culture to machined and anodized titanium surfaces as affected by atmosphere and pH
Background: With the rising demand for osseointegrated titanium implants for replacing missing teeth, often in patients with a history of periodontitis, implant-related infections have become an issue of growing concern. Novel methods for treating and preventing implant-associated infections are urgently needed. The aim of this study was to investigate if different pH, atmosphere and surface properties could restrict bacterial adhesion to titanium surfaces used in dental implants. Methods: Titanium discs with machined or anodized (TiUniteTM) surface were incubated with a co-culture of Streptococcus mitis and Actinomyces oris (early colonizers of oral surfaces) at pH 5.0, 7.0 and 9.0 at aerobic or anaerobic atmosphere. The adhesion was analysed by counting colony forming (CFU) units on agar and by confocal laser scanning microscopy (CLSM). Results: The CFU analysis showed that a pH of 5.0 was found to significantly decrease the adhesion of S. mitis, and an aerobic atmosphere, the adhesion of A. oris. S. mitis was found in significantly less amounts on the anodized surface than the machined surface, while A. oris was found in equal amounts on both surfaces. The CLSM analysis confirmed the results from the CFU count and provided additional information on how the two oral commensal species adhered to the surfaces: mainly in dispersed clusters oriented with the groves of the machined surface and the pores of the anodized surface. Conclusions: Bacterial adhesion by S. mitis and A. oris can be restricted by acidic pH and aerobic atmosphere. The anodized surface reduced the adhesion of S. mitis compared to the machined surface; while A. oris adhered equally well to the pores of the anodized surface and to the grooves of the machined surface. It is difficult to transfer these results directly into a clinical situation. However, it is worth further investigating these findings from an in vitro perspective, as well as clinically, to gain more knowledge of the effects acid pH and aerobic atmosphere have on initial bacterial adhesion
Bisfenolanaloger- anvÀndning och förekomst
Bisfenol A (BPA) Ă€r en omdiskuterad högvolymkemikalie som bl.a. har hormonstörande egenskaper. Det har visat sig internationellt att nĂ€r denna kemikalie fasas ut sĂ„ kan den ersĂ€ttas av andra bisfenoler, s.k. bisfenolanaloger. GenomgĂ„ngen av analogernas toxikologiska egenskaper visar dock att mĂ„nga av dessa Ă€mnen ur toxikologiskt perspektiv liknar BPA. PĂ„ uppdrag av NaturvĂ„rdsverket har en litteraturstudie om bisfenolanaloger utförts. Studien omfattar: Identifiering av olika bisfenolanaloger Beskrivning av bisfenolanalogers anvĂ€ndning och spridning SammanstĂ€llning av mĂ€tdata rörande bisfenolanalogers förekomst i miljön och i mĂ€nniska Ăversiktlig genomgĂ„ng av bisfenolanalogernas ekotoxikologiska och toxikologiska egenskaper. AnvĂ€ndning beskrivs frĂ€mst ur ett svenskt perspektiv, medan förekomst i miljö och mĂ€nniska beskrivs i ett internationellt perspektiv. I samtliga fall anvĂ€nds BPA som referensĂ€mne. Som direkt ersĂ€ttare till BPA anvĂ€nds bisfenol S, bisfenol S och bisfenol AP (BPF, BPS och BPAP). DĂ€rtill finns mĂ„nga bisfenolanaloger som delvis har andra tillĂ€mpningar. Totalt har vi identifierat ett 20-tal olika bisfenoler. Uppgifter om global produktion av dessa bisfenolanaloger saknas dock. För att beskriva de volymer som anvĂ€nds i Sverige har Produktregistrets uppgifter om anvĂ€ndning anvĂ€nts. Registret omfattar anvĂ€ndning i kemiska produkter men inte import i varor, vilket sannolikt ocksĂ„ Ă€r av betydelse för mĂ„nga av dessa Ă€mnen. Sökningen omfattar bisfenolanaloger som förekommer som monomerer, i diglycidyletrar och som förpolymerer. Totalt fann vi uppgifter om följande fem bisfenolanaloger registrerade i produktregistret: BPF, BPS, BPAF, BPZ och BPL. Dessa förekom i ett stort antal kemiska produkter. Resultaten kan sammanfattas enligt följande: Bland monomerer, diglycidyletrar och polymerer dominerar BPA markant över övriga bisfenolanaloger. BPAF förekommer endast som monomer eller salt. BPS förekommer frĂ€mst som polymer. BPF förekommer bĂ„de som diglycidyleter och polymer i form av epoxi, och sannolikt Ă€ven som monomer. TvĂ„ former av BPF anvĂ€nds: orto- och para-. Hydrogenerad BPA (HBPA) finns enligt produktregistret som sam- och blandpolymer, funktionen av denna Ă€r okĂ€nd. I strikt mening Ă€r HBPA dock inte en bisfenol. BPZ (polymer) och BFL (monomer) Ă€r registrerade i smĂ„ mĂ€ngder Följande monomerer har ej pĂ„trĂ€ffats i produktregistret: BPB, BPP, BPE, BPC. För nĂ„gra av de mĂ€ngdmĂ€ssigt mer betydande analogerna beskrivs hur den registrerade anvĂ€ndningen förĂ€ndats över perioden 1992-2012. MĂ„nga av Ă€mnena har varit registrerade sedan 1990-talet. NĂ„gra tendenser till ökande anvĂ€ndning under senare Ă„r kan ses för: BPAF som monomer BPF som digycidyleter (BFDGE) BPS och HBPA som polymer. Sammantaget bedöms det inte som att anvĂ€ndningen av bisfenolanaloger Ă€r fullstĂ€ndigt beskriven. Detta beror frĂ€mst pĂ„ att import via varor ej kunnat beskrivas och Ă€ven pĂ„ att det internationella kunskapslĂ€get Ă€r begrĂ€nsat. NĂ„gra svenska miljödata har ej pĂ„trĂ€ffats för andra bisfenoler Ă€n BPA, och Ă€ven internationellt finns fĂ„ undersökningar av bisfenolanaloger. Som mest finns förekomst av Ă„tta analoger beskrivna för sediment och slam. AllmĂ€nt Ă€r BPA vanligast, följt av BPF och BPS. Studier av sedimentkĂ€rnor visar att BPF spridits under Ă„tminstone nĂ„gra Ă„rtionden. I sediment frĂ„n USA och Japan förekom BPF i nĂ€stan samma halter som BPA. Tyska sediment insamlade i slutet av 1990-talet visade större haltskillnader mellan BPA och BPF. En omfattande kinesisk studie av Ă„tta bisfenoler i slam visade mycket stora haltvariationer mellan enskilda reningsverk, med dominans av BPA, BPF och BPS (medianhalter var 9,4, 2,0 och 4,3 ÎŒg/kg ts, respektive). Betydligt lĂ€gre halter pĂ„visades för BPAF och BPE, emedan BPAP, BPB och BPC ej detekterades. Human exponering för BPA sker bl.a. via hudkontakt med kvitton, livsmedel och damm. DĂ€rför har uppgifter om bisfenoler i dessa matriser sammanstĂ€llts. Mycket fĂ„ data föreligger. Livsmedel frĂ„n Kina och USA har undersökts avseende BPA och sju analoger. Samtliga undersökta Ă€mnen pĂ„trĂ€ffades men i mycket varierande grad och i varierande halter. Trots de stora variationerna inom respektive land sĂ„ rĂ„der stora likheter mellan data frĂ„n USA och Kina. BPA dominerar, tĂ€tt följd av BPF, BPS, BPP och BPAP m.fl. I damm frĂ„n bostĂ€der och kontor i USA och Asien pĂ„visades BPA och sex av sju undersökta analoger. Generellt var BPA vanligast, följt av BPS och BPF. Ăvriga analoger upptrĂ€dde i mycket lĂ„ga halter. Som exponeringsvĂ€g för mĂ€nniskor tyder dessa data pĂ„ att livsmedel generellt Ă€r mer betydande Ă€n damm. Vad gĂ€ller BPS tyder data frĂ„n USA dock pĂ„ att för enskilda individer kan damm vara mer betydelsefull exponeringskĂ€lla Ă€n livsmedel. I Sverige har data pĂ„ BPA, BPF och BPS i urin nyligen presenterats. BPF upptrĂ€dde i ungefĂ€r tio gĂ„nger lĂ€gre halter Ă€n BPA, medan BPS endast detekterades i ett fĂ„tal prov. Liknande resultat finns ocksĂ„ frĂ„n USA och sju asiatiska lĂ€nder. I rapporten presenteras ocksĂ„ en översiktlig genomgĂ„ng av Ă€mnenas fysikalisk-kemiska, ekotoxikologiska och toxikologiska egenskaper. Flertalet bisfenoler har hög vattenlöslighet och liknande endokrinstörande egenskaper som BPA. En hĂ€lsoriskbedömning bör dĂ€rför utföras för bisfenolanalogerna som en grupp Ă€mnen, med hĂ€nsyn tagen till vissa skillnader inom gruppen beroende pĂ„ substituerad funktionell grupp. Huruvida BPA utgör hĂ€lsorisker under rĂ„dande exponeringsförhĂ„llanden Ă€r omdiskuterat, framförallt beroende pĂ„ tolkningenav s.k. lĂ„gdoseffekter. Om man accepterar att BPA kan ge effekter vid lĂ„ga doser sĂ„ förefaller det rimligt att Ă€ven exponering för bisfenolanaloger skulle kunna bidra till dessa risker. Sammanfattningsvis sĂ„ tyder merparten av hittills genomförda undersökningar i andra lĂ€nder, liksom svenska uppgifter om anvĂ€ndning, pĂ„ att BPA fortfarande dominerar den totala mĂ€ngden bisfenoler i miljön eller i human exponering. Eftersom Ă€mnenas egenskaper liknar de för BPA, och eftersom BPA i viss mĂ„n substitueras mot andra bisfenoler, bedöms det Ă€ndĂ„ relevant att följa nĂ„gra bisfenolanaloger i den svenska miljön eller i den svenska befolkningen. För human urin finns ett Ă„terkommande övervakningsprogram. DĂ€rutöver föreslĂ„r vi en bred undersökning av slam frĂ„n ett större antal reningsverk som en första screening av bisfenolanaloger. Det kan dock förvĂ€ntas att halterna kommer vara lĂ„ga och att kontamineringsrisker föreligger
Functional Characterization of Nine Norway Spruce TPS Genes and Evolution of Gymnosperm Terpene Synthases of the TPS-d Subfamily
Constitutive and induced terpenoids are important defense compounds for many plants against potential herbivores and pathogens. In Norway spruce (Picea abies L. Karst), treatment with methyl jasmonate induces complex chemical and biochemical terpenoid defense responses associated with traumatic resin duct development in stems and volatile terpenoid emissions in needles. The cloning of (+)-3-carene synthase was the first step in characterizing this system at the molecular genetic level. Here we report the isolation and functional characterization of nine additional terpene synthase (TPS) cDNAs from Norway spruce. These cDNAs encode four monoterpene synthases, myrcene synthase, (â)-limonene synthase, (â)-α/ÎČ-pinene synthase, and (â)-linalool synthase; three sesquiterpene synthases, longifolene synthase, E,E-α-farnesene synthase, and E-α-bisabolene synthase; and two diterpene synthases, isopimara-7,15-diene synthase and levopimaradiene/abietadiene synthase, each with a unique product profile. To our knowledge, genes encoding isopimara-7,15-diene synthase and longifolene synthase have not been previously described, and this linalool synthase is the first described from a gymnosperm. These functionally diverse TPS account for much of the structural diversity of constitutive and methyl jasmonate-induced terpenoids in foliage, xylem, bark, and volatile emissions from needles of Norway spruce. Phylogenetic analyses based on the inclusion of these TPS into the TPS-d subfamily revealed that functional specialization of conifer TPS occurred before speciation of Pinaceae. Furthermore, based on TPS enclaves created by distinct branching patterns, the TPS-d subfamily is divided into three groups according to sequence similarities and functional assessment. Similarities of TPS evolution in angiosperms and modeling of TPS protein structures are discussed
Functional Characterization of Nine Norway Spruce TPS Genes and Evolution of Gymnosperm Terpene Synthases of the TPS-d Subfamily
Constitutive and induced terpenoids are important defense compounds for many plants against potential herbivores and pathogens. In Norway spruce (Picea abies L. Karst), treatment with methyl jasmonate induces complex chemical and biochemical terpenoid defense responses associated with traumatic resin duct development in stems and volatile terpenoid emissions in needles. The cloning of (+)-3-carene synthase was the first step in characterizing this system at the molecular genetic level. Here we report the isolation and functional characterization of nine additional terpene synthase (TPS) cDNAs from Norway spruce. These cDNAs encode four monoterpene synthases, myrcene synthase, (â)-limonene synthase, (â)-α/ÎČ-pinene synthase, and (â)-linalool synthase; three sesquiterpene synthases, longifolene synthase, E,E-α-farnesene synthase, and E-α-bisabolene synthase; and two diterpene synthases, isopimara-7,15-diene synthase and levopimaradiene/abietadiene synthase, each with a unique product profile. To our knowledge, genes encoding isopimara-7,15-diene synthase and longifolene synthase have not been previously described, and this linalool synthase is the first described from a gymnosperm. These functionally diverse TPS account for much of the structural diversity of constitutive and methyl jasmonate-induced terpenoids in foliage, xylem, bark, and volatile emissions from needles of Norway spruce. Phylogenetic analyses based on the inclusion of these TPS into the TPS-d subfamily revealed that functional specialization of conifer TPS occurred before speciation of Pinaceae. Furthermore, based on TPS enclaves created by distinct branching patterns, the TPS-d subfamily is divided into three groups according to sequence similarities and functional assessment. Similarities of TPS evolution in angiosperms and modeling of TPS protein structures are discussed
Widespread Occurrence of Non-Extractable Fluorine in Artificial Turfs from Stockholm, Sweden
Per- and polyfluoroalkyl substances (PFAS) are frequently used in the production of rubber and plastic, but little is known about the identity, concentration, or prevalence of PFAS in these products. In this study, a representative sample of plastic- and rubber-containing artificial turf (AT) fields from Stockholm, Sweden, were subjected to total fluorine (TF), extractable organic fluorine (EOF) and target PFAS analysis. TF was observed in all 51 AT samples (range: 16-313, 12-310, and 24-661 ”g F/g in backing, filling, and blades, respectively), while EOF and target PFAS occurred in <42% of all samples (<200 and <1 ng F/g, respectively). A subset of samples extracted with water confirmed the absence of fluoride. Moreover, application of the total oxidizable precursor assay revealed negligible perfluoroalkyl acid (PFAA) formation across all three sample types, indicating that the fluorinated substance(s) in AT are not low molecular weight PFAA-precursors. Collectively, these results point towards polymeric organofluorine (e.g. fluoroelastomer, polytetrafluoroethylene, polyvinylidene fluoride), consistent with patent literature. The combination of poor extractability and recalcitrance towards advanced oxidation suggests that the fluorine in AT does not pose an imminent risk to users. However, concerns remain surrounding the production and end-of-life of ATs, as well as the contribution of filling to environmental microplastic contamination