Browsing by Subject "DAMAGE"

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  • Tuohinen, Suvi Sirkku; Skyttä, Tanja; Huhtala, Heini; Poutanen, Tuija; Virtanen, Vesa; Kellokumpu-Lehtinen, Pirkko-Liisa; Raatikainen, Pekka (2021)
    BACKGROUND Radiation therapy (RT) results in myocardial changes consisting of diffuse fibrosis, which may result in changes in diastolic function. OBJECTIVES The aim of this study was to explore RT-associated changes in left ventricular (LV) diastolic function. METHODS Sixty chemotherapy-naive patients with left-sided, early-stage breast cancer were studied with speckle tracking echocardiography at 3 time points: prior to, immediately after, and 3 years after RT. Global and regional early diastolic strain rate (SRe) were quantified, as were parameters of systolic function. RESULTS Regional changes in SRe, particularly the apical and anteroseptat segments, were observed over time and were more evident than global changes. The apical SRe declined from a median of 1.24 (interquartile range: 1.01 to 1.39) s(-1) at baseline to 1.02 (interquartile range: 0.79 to 1.15) s(-1) at 3 years of follow-up (p < 0.001). This decline was associated with the left ventricular maximal radiation dose (beta = 0.36, p = 0.007). The global SRe was CONCLUSIONS RT resulted in changes in the SRe in the apical and anteroseptat segments over 3 years of follow-up. Changes in SRe apical segments were present even in patients with preserved systolic function and were independently associated with RT dose and cardiovascular comorbidities. (C) 2021 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation.
  • Tammiste, Triin; Kask, Keiu; Padrik, Peeter; Idla, Kulli; Rosenstein, Karin; Jatsenko, Tatjana; Veerus, Piret; Salumets, Andres (2019)
    BackgroundOvarian insufficiency is a major concern for long-term cancer survivors. Although semen freezing is well established to preserve male fertility, the possibilities to secure post-cancer female fertility are mostly limited to oocyte or embryo freezing. These methods require time-consuming ovarian stimulation with or without in vitro fertilization (IVF) that evidently delays cancer therapy. Ovarian tissue cryopreservation and subsequent thawed tissue autotransplantation are considered the most promising alternative strategy for restoring the fertility of oncology patients, which has not yet received the full clinical acceptance. Therefore, all successful cases are needed to prove its reliability and safety.Case presentationHere we report a single case in Estonia, where a 28-year-old woman with malignant breast neoplasm had ovarian cortex cryopreserved before commencing gonadotoxic chemo- and radiotherapy. Two years after cancer therapy, the patient underwent heterotopic ovarian tissue transplantation into the lateral pelvic wall. The folliculogenesis was stimulated in the transplanted tissue by exogenous follicle-stimulating hormone and oocytes were collected under ultrasound guidance for IVF and embryo transfer. The healthy boy was born after full-term gestation in 2014, first in Eastern Europe.ConclusionDespite many countries have reported the first implementation of the ovarian tissue freezing and transplantation protocols, the data is still limited on the effectiveness of heterotopic ovarian transplant techniques. Thus, all case reports of heterotopic ovarian tissue transplantation and long-term follow-ups to describe the children's health are valuable source of clinical experience.
  • Lahtinen, Alexandra; Puttonen, Sampsa; Vanttola, Päivi; Viitasalo, Katriina; Sulkava, Sonja; Pervjakova, Natalia; Joensuu, Anni; Salo, Perttu; Toivola, Auli; Härmä, Mikko; Milani, Lili; Perola, Markus; Paunio, Tiina (2019)
    Short sleep duration or insomnia may lead to an increased risk of various psychiatric and cardio-metabolic conditions. Since DNA methylation plays a critical role in the regulation of gene expression, studies of differentially methylated positions (DMPs) might be valuable for understanding the mechanisms underlying insomnia. We performed a cross-sectional genome-wide analysis of DNA methylation in relation to self-reported insufficient sleep in individuals from a community-based sample (79 men, aged 39.3 +/- 7.3), and in relation to shift work disorder in an occupational cohort (26 men, aged 44.9 +/- 9.0). The analysis of DNA methylation data revealed that genes corresponding to selected DMPs form a distinctive pathway: "Nervous System Development" (FDR P value <0.05). We found that 78% of the DMPs were hypomethylated in cases in both cohorts, suggesting that insufficient sleep may be associated with loss of DNA methylation. A karyoplot revealed clusters of DMPs at various chromosomal regions, including 12 DMPs on chromosome 17, previously associated with Smith-Magenis syndrome, a rare condition comprising disturbed sleep and inverse circadian rhythm. Our findings give novel insights into the DNA methylation patterns associated with sleep loss, possibly modifying processes related to neuroplasticity and neurodegeneration. Future prospective studies are needed to confirm the observed associations.
  • Blaser, Cornelia; Klein, Matthias; Grandgirard, Denis; Wittwer, Matthias; Peltola, Heikki; Weigand, Michael; Koedel, Uwe; Leib, Stephen L. (2010)
  • Kivimäki, Mika; Singh-Manoux, Archana; Batty, G. David; Sabia, Severine; Sommerlad, Andrew; Floud, Sarah; Jokela, Markus; Vahtera, Jussi; Beydoun, May A.; Suominen, Sakari B.; Koskinen, Aki; Väänänen, Ari; Goldberg, Marcel; Zins, Marie; Alfredsson, Lars; Westerholm, Peter J. M.; Knutsson, Anders; Nyberg, Solja T.; Sipilä, Pyry N.; Lindbohm, Joni V.; Pentti, Jaana; Livingston, Gill; Ferrie, Jane E.; Strandberg, Timo (2020)
    This cohort study examines the association of overall consumption of alcohol and resultant loss of consciousness with risk for dementia. Question Are alcohol-induced loss of consciousness and heavy weekly alcohol consumption associated with increased risk of future dementia? Findings In this multicohort study of 131x202f;415 adults, a 1.2-fold excess risk of dementia was associated with heavy vs moderate alcohol consumption. Those who reported having lost consciousness due to alcohol consumption, regardless of their overall weekly consumption, had a 2-fold increased risk of dementia compared with people who had not lost consciousness and were moderate drinkers. Meaning The findings of this study suggest that alcohol-induced loss of consciousness is a long-term risk factor for dementia among both heavy and moderate drinkers. Importance Evidence on alcohol consumption as a risk factor for dementia usually relates to overall consumption. The role of alcohol-induced loss of consciousness is uncertain. Objective To examine the risk of future dementia associated with overall alcohol consumption and alcohol-induced loss of consciousness in a population of current drinkers. Design, Setting, and Participants Seven cohort studies from the UK, France, Sweden, and Finland (IPD-Work consortium) including 131x202f;415 participants were examined. At baseline (1986-2012), participants were aged 18 to 77 years, reported alcohol consumption, and were free of diagnosed dementia. Dementia was examined during a mean follow-up of 14.4 years (range, 12.3-30.1). Data analysis was conducted from November 17, 2019, to May 23, 2020. Exposures Self-reported overall consumption and loss of consciousness due to alcohol consumption were assessed at baseline. Two thresholds were used to define heavy overall consumption: greater than 14 units (U) (UK definition) and greater than 21 U (US definition) per week. Main Outcomes and Measures Dementia and alcohol-related disorders to 2016 were ascertained from linked electronic health records. Results Of the 131x202f;415 participants (mean [SD] age, 43.0 [10.4] years; 80x202f;344 [61.1%] women), 1081 individuals (0.8%) developed dementia. After adjustment for potential confounders, the hazard ratio (HR) was 1.16 (95% CI, 0.98-1.37) for consuming greater than 14 vs 1 to 14 U of alcohol per week and 1.22 (95% CI, 1.01-1.48) for greater than 21 vs 1 to 21 U/wk. Of the 96x202f;591 participants with data on loss of consciousness, 10x202f;004 individuals (10.4%) reported having lost consciousness due to alcohol consumption in the past 12 months. The association between loss of consciousness and dementia was observed in men (HR, 2.86; 95% CI, 1.77-4.63) and women (HR, 2.09; 95% CI, 1.34-3.25) during the first 10 years of follow-up (HR, 2.72; 95% CI, 1.78-4.15), after excluding the first 10 years of follow-up (HR, 1.86; 95% CI, 1.16-2.99), and for early-onset (= 65 y: HR, 2.25; 95% CI, 1.38-3.66) dementia, Alzheimer disease (HR, 1.98; 95% CI, 1.28-3.07), and dementia with features of atherosclerotic cardiovascular disease (HR, 4.18; 95% CI, 1.86-9.37). The association with dementia was not explained by 14 other alcohol-related conditions. With moderate drinkers (1-14 U/wk) who had not lost consciousness as the reference group, the HR for dementia was twice as high in participants who reported having lost consciousness, whether their mean weekly consumption was moderate (HR, 2.19; 95% CI, 1.42-3.37) or heavy (HR, 2.36; 95% CI, 1.57-3.54). Conclusions and Relevance The findings of this study suggest that alcohol-induced loss of consciousness, irrespective of overall alcohol consumption, is associated with a subsequent increase in the risk of dementia.
  • Holmstrom, E.; Kotakoski, J.; Lechner, L.; Kaiser, U.; Nordlund, K. (2012)
  • Oya, Yasuhisa; Masuzaki, Suguru; Tokitani, Masayuki; Azuma, Keisuke; Oyaidzu, Makoto; Isobe, Kanetsugu; Asakura, Nobuyuki; Widdowson, Anna M.; Heinola, Kalle; Jachmich, Stefan; Rubel, Marek; JET contributors; Ahlgren, Tommy (2018)
    To understand the fuel retention mechanism correlation of surface chemical states and hydrogen isotope retention behavior determined by XPS (X-ray photoelectron spectroscopy) and TDS (Thermal desorption spectroscopy), respectively, for JET ITER-Like Wall samples from operational period 2011–2012 were investigated. It was found that the deposition layer was formed on the upper part of the inner vertical divertor area. At the inner plasma strike point region, the original surface materials, W or Mo, were found, indicating to an erosion-dominated region, but deposition of impurities was also found. Higher heat load would induce the formation of metal carbide. At the outer horizontal divertor tile, mixed material layer was formed with iron as an impurity. TDS showed the H and D desorption behavior and the major D desorption temperature for the upper part of the inner vertical tile was located at 370 °C and 530 °C. At the strike point region, the D desorption temperature was clearly shifted toward higher release temperatures, indicating the stabilization of D trapping by higher heat load
  • Sioofy-Khojine, Amir-Babak; Lehtonen, Jussi; Nurminen, Noora; Laitinen, Olli H.; Oikarinen, Sami; Huhtala, Heini; Pakkanen, Outi; Ruokoranta, Tanja; Hankaniemi, Minna M.; Toppari, Jorma; Vähä-Mäkilä, Mari; Ilonen, Jorma; Veijola, Riitta; Knip, Mikael; Hyöty, Heikki (2018)
    Aims/hypothesis Islet autoimmunity usually starts with the appearance of autoantibodies against either insulin (IAA) or GAD65 (GADA). This categorises children with preclinical type 1 diabetes into two immune phenotypes, which differ in their genetic background and may have different aetiology. The aim was to study whether Coxsackievirus group B (CVB) infections, which have been linked to the initiation of islet autoimmunity, are associated with either of these two phenotypes in children with HLA-conferred susceptibility to type 1 diabetes. Methods All samples were from children in the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study. Individuals are recruited to the DIPP study from the general population of new-born infants who carry defined HLA genotypes associated with susceptibility to type 1 diabetes. Our study cohort included 91 children who developed IAA and 78 children who developed GADA as their first appearing single autoantibody and remained persistently seropositive for islet autoantibodies, along with 181 and 151 individually matched autoantibody negative control children, respectively. Seroconversion to positivity for neutralising antibodies was detected as the surrogate marker of CVB infections in serial follow-up serum samples collected before and at the appearance of islet autoantibodies in each individual. Results CVB1 infections were associated with the appearance of IAA as the first autoantibody (OR 2.4 [95% CI 1.4, 4.2], corrected p = 0.018). CVB5 infection also tended to be associated with the appearance of IAA, however, this did not reach statistical significance (OR 2.3, [0.7, 7.5], p = 0.163); no other CVB types were associated with increased risk of IAA. Children who had signs of a CVB1 infection either alone or prior to infections by other CVBs were at the highest risk for developing IAA (OR 5.3 [95% CI 2.4, 11.7], p <0.001). None of the CVBs were associated with the appearance of GADA. Conclusions/interpretation CVB1 infections may contribute to the initiation of islet autoimmunity being particularly important in the insulin-driven autoimmune process.
  • Hassan, Alaa A.; Aly, Ashraf A.; Mohamed, Nasr K.; El Shaieb, Kamal M.; Makhlouf, Maysa M.; Abdelhafez, El-Shimaa M. N.; Bräse, Stefan; Nieger, Martin; Dalby, Kevin N.; Kaoud, Tamer S. (2019)
    A large number of natural products containing the propellane scaffold have been reported to exhibit cytotoxicity against several cancers; however, their mechanism of action is still unknown. Anticancer drugs targeting DNA are mainly composed of small planar molecule/s that can interact with the DNA helix, causing DNA malfunction and cell death. The aim of this study was to design and synthesize propellane derivatives that can act as DNA intercalators and/or groove binders. The unique structure of the propellane derivatives and their ability to display planar ligands with numerous possible geometries, renders them potential starting points to design new drugs targeting DNA in cancer cells. New substituted furo-imidazo[3.3.3]propellanes were synthesized via the reaction of substituted alkenylidene-hydrazinecarbothioamides with 2-(1,3-dioxo-2,3-dihydr- 1H-2-ylidene) propanedinitrile in tetrahydrofuran at room temperature. The structures of the products were confirmed by a combination of elemental analysis, NMR, ESI-MS, IR and single crystal X-ray analysis. Interestingly, 5c, 5d and 5f showed an ability to interact with Calf Thymus DNA (CT-DNA). Their DNA-binding mode was investigated using a combination of absorption spectroscopy, DNA melting, viscosity, CD spectroscopy measurements, as well as competitive binding studies with several dyes. Their cytotoxicity was evaluated against the NCI-60 panel of cancer cell lines. 5c, 5d and 5f exhibited similar anti-proliferative activity against the A549 non-small cell lung cancer (NSCLC) cell line. Further mechanistic studies revealed their ability to induce DNA damage in the A549 cell line, as well as apoptosis, evidenced by elevated Annexin V expression, enhanced caspase 3/7 activation and PARP cleavage. In this study, we present the potential for designing novel propellanes to provoke cytotoxic activity, likely through DNA binding-induced DNA damage and apoptosis.
  • Lindqvist, U.; Gudbjornsson, B.; Iversen, L.; Laasonen, L.; Ejstrup, L.; Ternowitz, T.; Stahle, M. (2017)
    Objective: To describe the social status and health-related quality of life of patients with psoriatic arthritis mutilans (PAM) in the Nordic countries.Method: Patients with at least one mutilated joint confirmed by radiology were studied. Disease activity involving joints and skin, physician-assessed disease activity, and patient's education and work status were recorded. Data from the 36-item Short Form Health Survey, Health Assessment Questionnaire and Dermatology Life Quality Index questionnaire were gathered and correlated with disease duration, pain, and general well-being (visual analogue scale). The controls were 58 Swedish patients with long-standing psoriatic arthritis sine PAM.Results: Sixty-seven patients were included. Patients with PAM had a protracted disease history (3314years) and disease onset at a relatively early age (30 +/- 12years). Overall inflammatory activity at inclusion was mild to moderate. The mean number of mutilated joints was 8.2 and gross deformity was found in 16% of patients. Forty per cent were treated with biological and 32% with conventional synthetic disease-modifying anti-rheumatic drugs. Forty-two per cent had retired early or were on sick leave. Impaired functional capacity with little or no ability to perform self-care or everyday tasks was reported by 21% of the patients. Patients between 45 and 60years of age reported the most impaired quality of life in comparison to the control group.Conclusion: PAM seriously affects social functioning. Whether early recognition of PAM and new forms of therapy can improve disease outcome and quality of life remains to be studied.
  • Osorio, Ana; Milne, Roger L.; Kuchenbaecker, Karoline; Vaclova, Tereza; Pita, Guillermo; Alonso, Rosario; Peterlongo, Paolo; Blanco, Ignacio; de la Hoya, Miguel; Duran, Mercedes; Diez, Orland; Ramon y Cajal, Teresa; Konstantopoulou, Irene; Martinez-Bouzas, Cristina; Conejero, Raquel Andres; Soucy, Penny; McGuffog, Lesley; Barrowdale, Daniel; Lee, Andrew; Arver, Brita; Rantala, Johanna; Loman, Niklas; Ehrencrona, Hans; Olopade, Olufunmilayo I.; Beattie, Mary S.; Domchek, Susan M.; Nathanson, Katherine; Rebbeck, Timothy R.; Arun, Banu K.; Karlan, Beth Y.; Walsh, Christine; Lester, Jenny; John, Esther M.; Whittemore, Alice S.; Daly, Mary B.; Southey, Melissa; Hopper, John; Terry, Mary B.; Buys, Saundra S.; Janavicius, Ramunas; Dorfling, Cecilia M.; van Rensburg, Elizabeth J.; Steele, Linda; Neuhausen, Susan L.; Ding, Yuan Chun; Hansen, Thomas V. O.; Jonson, Lars; Ejlertsen, Bent; Nevanlinna, Heli; Aittomaki, Kristiina; SWE-BRCA; HEBON; KConFab Investigators (2014)
  • Auvinen, Vili-Veli; Merivaara, Arto; Kiiskinen, Jasmi; Paukkonen, Heli; Laurén, Patrick; Hakkarainen, Tiina; Koivuniemi, Raili; Sarkanen, Riina; Ylikomi, Timo; Laaksonen, Timo; Yliperttula, Marjo (2019)
    The aim of this study was to evaluate the effects of two nanofibrillated cellulose (NFC) hydrogels on two human derivatives during freeze-drying. Native NFC hydrogel is a suitable platform to culture 3D cell spheroids and a hydrogel processed further, called anionic NFC (ANFC) hydrogel, is an excellent platform for controlled release of proteins. Moreover, it has been shown to be compatible with freeze-drying when correct lyoprotectants are implemented. Freeze-drying is a method, where substance is first frozen, and then vacuum dried trough sublimation of water in order to achieve dry matter without the loss of the original three-dimensional structures. The first chosen human derivative was adipose tissue extract (ATE) which is a cell-free growth factor-rich preparation capable of promoting growth of regenerative cells. The release of growth factors from the freeze-dried mixture of ATE and ANFC was compared to that of non-freeze-dried control mixtures. The release profiles remained at the same level after freeze-drying. The second derivative was hepatocellular carcinoma (HepG2) cell spheroids which were evaluated before and after freeze-drying. The 3D structure of the HepG2 cell spheroids was preserved and the spheroids retained 18% of their metabolic activity after rehydration. However, the freeze-dried and rehydrated HepG2 cell spheroids did not proliferate and the cell membrane was damaged by fusion and formation of crystals.
  • Alegre, Sara; Pascual, Jesús; Trotta, Andrea; Angeleri, Martina; Rahikainen, Moona; Brosche, Mikael; Moffatt, Barbara; Kangasjärvi, Saijaliisa (2020)
    Trans-methylation reactions are intrinsic to cellular metabolism in all living organisms. In land plants, a range of substrate-specific methyltransferases catalyze the methylation of DNA, RNA, proteins, cell wall components and numerous species-specific metabolites, thereby providing means for growth and acclimation in various terrestrial habitats. Trans-methylation reactions consume vast amounts of S-adenosyl-L-methionine (SAM) as a methyl donor in several cellular compartments. The inhibitory reaction by-product, S-adenosyl-L-homocysteine (SAH), is continuously removed by SAH hydrolase (SAHH), which essentially maintains trans-methylation reactions in all living cells. Here we report on the evolutionary conservation and post-translational control of SAHH in land plants. We provide evidence suggesting that SAHH forms oligomeric protein complexes in phylogenetically divergent land plants and that the predominant protein complex is composed by a tetramer of the enzyme. Analysis of light-stress-induced adjustments of SAHH in Arabidopsis thaliana and Physcomitrella patens further suggests that regulatory actions may take place on the levels of protein complex formation and phosphorylation of this metabolically central enzyme. Collectively, these data suggest that plant adaptation to terrestrial environments involved evolution of regulatory mechanisms that adjust the trans-methylation machinery in response to environmental cues.
  • Int Stroke Genetics Consortium; NINDS-SiGN Consortium; Genetics Ischaemic Stroke Funct; Söderholm, Martin; Pedersen, Annie; Strbian, Daniel; Tatlisumak, Turgut (2019)
    Objective To discover common genetic variants associated with poststroke outcomes using a genome-wide association (GWA) study. Methods The study comprised 6,165 patients with ischemic stroke from 12 studies in Europe, the United States, and Australia included in the GISCOME (Genetics of Ischaemic Stroke Functional Outcome) network. The primary outcome was modified Rankin Scale score after 60 to 190 days, evaluated as 2 dichotomous variables (0-2 vs 3-6 and 0-1 vs 2-6) and subsequently as an ordinal variable. GWA analyses were performed in each study independently and results were meta-analyzed. Analyses were adjusted for age, sex, stroke severity (baseline NIH Stroke Scale score), and ancestry. The significance level was p <5 x 10(-8). Results We identified one genetic variant associated with functional outcome with genome-wide significance (modified Rankin Scale scores 0-2 vs 3-6, p = 5.3 x 10(-9)). This intronic variant (rs1842681) in the LOC105372028 gene is a previously reported trans-expression quantitative trait locus for PPP1R21, which encodes a regulatory subunit of protein phosphatase 1. This ubiquitous phosphatase is implicated in brain functions such as brain plasticity. Several variants detected in this study demonstrated suggestive association with outcome (p <10(-5)), some of which are within or near genes with experimental evidence of influence on ischemic stroke volume and/or brain recovery (e.g., NTN4, TEK, and PTCH1). Conclusions In this large GWA study on functional outcome after ischemic stroke, we report one significant variant and several variants with suggestive association to outcome 3 months after stroke onset with plausible mechanistic links to poststroke recovery. Future replication studies and exploration of potential functional mechanisms for identified genetic variants are warranted.
  • Kupka, K.; Leino, A. A.; Ren, W.; Vazquez, H.; Åhlgren, E. H.; Nordlund, K.; Tomut, M.; Trautmann, C.; Kluth, P.; Toulemonde, M.; Djurabekova, F. (2018)
    Stable C-C bonds existing in several sp hybridizations place carbon thin films of different structural compositions among the materials most tolerant to radiation damage, for applications in extreme environments. One of such applications, solid state electron stripper foils for heavy-ion accelerators, requires the understanding of the structural changes induced by high-energy ion irradiation. Tolerance of carbon structure to radiation damage, thermal effects and stress waves due to swift heavy ion impacts defines the lifetime and operational efficiency of the foils. In this work, we analyze the consequences of a single swift heavy ion impact on two different amorphous carbon structures by means of molecular dynamic simulations. The structures are constructed by using two different recipes to exclude the correlation of the evolution of sp2-to-sp3 hybridization with the initial condition. Both initial structures contain approximately 60% of sp2-bonded carbon atoms, however, with different degree of clustering of atoms with sp3 hybridization. We simulate the swift heavy ion impact employing an instantaneous inelastic thermal spike model. The analysis of changes in density, bonding content and the number and size of carbon primitive rings reveals graphitization of the material within the ion track, with higher degree of disorder in the core and more order in the outer shell. Simulated track dimensions are comparable to those observed in small angle x-ray scattering measurements of evaporation-deposited amorphous carbon stripper foils irradiated by 1.14 GeV U ions.
  • Valros, Anna; Välimäki, Elina; Nordgren, Heli; Vugts, Johannes; Fabrega, Emma; Heinonen, Mari (2020)
    Tail biting lesions are a potential measure of on-farm animal welfare, as a large range of stressors increase the risk for tail biting outbreaks. Further, tail biting is a major challenge, as lesions due to tail biting decrease animal welfare and health, as well as production efficiency and carcass quality. The aim of this study was to suggest a tail scoring system for use at slaughterhouses processing undocked pigs, and to link tail lesion scores to meat inspection data. A further aim was to suggest a definition for an intact enough tail. To validate the suggested scoring system we assessed tails before and after scalding and compared results to pathological examinations. In total, 14,433 tails were scored, and 117 tails were collected for pathological examination. After scalding, 49.2% of all tails were scored as fully intact. Of tails with lesions 2.5% were scored as having major acute wounds (>2 cm), while 11.6% had minor acute wounds (
  • Honkaniemi, Juha; Ojansuu, Risto; Kasanen, Risto; Heliövaara, Kari (2018)
    Interaction of disturbance agents may cause cascading effects in forests. The three most important disturbance agents of Norway spruce (Picea abies) in northern Europe are Heterobasidion root rot, wind and the European spruce bark beetle (Ips typographus). In this study, we present a mechanistic individual agent based model to simulate the dynamics of the bark beetle and integrate it in the simulation framework WINDROT to further study the interactive dynamics of root rot, wind and bark beetles. We carried out model performance analysis concluding that the model is sensitive to the parameters of optimal bark thickness for reproduction. Stand level interaction between wind and bark beetle disturbances was also evaluated against field data. The stand level simulations show the interaction between the disturbance agents; the root rot increases wind disturbance and bark beetles benefit from wind fallen trees. No direct interaction was found in the simulation study between the root rot and bark beetles. Further experimental research and large scale simulation studies are needed to better understand the underlying mechanisms in the interaction between the disturbance agents.
  • Herbig, Charlotte; Åhlgren, E. Harriet; Jolie, Wouter; Busse, Carsten; Kotakoski, Jani; Krasheninnikov, Arkady V.; Michely, Thomas (2014)
  • Demyanenko, Svetlana; Gantsgorn, Elena; Rodkin, Stanislav; Sharifulina, Svetlana (2020)
    Sirtuins, class III histone deacetylases, are involved in the regulation of tissue repair processes and brain functions after a stroke. The ability of some isoforms of sirtuins to circulate between the nucleus and cytoplasm may have various pathophysiological effects on the cells. In present work, we focused on the role of non-mitochondrial sirtuins SIRT1, SIRT2, and SIRT6 in the restoration of brain cells following ischemic stroke. Here, using a photothrombotic stroke (PTS) model in mice, we studied whether local stroke affects the level and intracellular localization of SIRT1, SIRT2, and SIRT6 in neurons and astrocytes of the intact cerebral cortex adjacent to the ischemic ipsilateral hemisphere and in the analogous region of the contralateral hemisphere at different time points during the recovery period after a stroke. We evaluated the co-localization of sirtuins with growth-associated protein-43 (GAP 43), the presynaptic marker synaptophysin (SYN) and acetylated a-tubulin (Aca-Tub), that are associated with brain plasticity and are known to be involved in brain repair after a stroke. The results show that during the recovery period, an increase in SIRT1 and SIRT2 levels occurred. The increase of SIRT1 level was associated with an increase in synaptic plasticity proteins, whereas the increase of SIRT2 level was associated with an acetylated of a-tubulin, that can reduce the mobility of neurites. SIRT6 co-localized with GAP-43, but not with SYN. Moreover, we showed that SIRT1, SIRT2, and SIRT6 are not involved in the PTS-induced apoptosis of pen umbra cells. Taken together, our results suggest that sirtuins functions differ depending on cell type, intracellular localization, specificity of sirtuins isoforms to different substrates and nature of post-translational modifications of enzymes.
  • Henriksson, K. O. E. (2016)
    The number of point defects formed in spherical cementite and Cr23C6 inclusions embedded into ferrite (alpha-iron) has been studied and compared against cascades in pure versions of these materials (only ferrite, Fe3C, or Cr23C6 in a cell). Recoil energies between 100 eV and 3 keV and temperatures between 400 K and 1000 K were used. The overall tendency is that the number of point defects-such as antisites, vacancy and interstitials-increases with recoil energy and temperature. The radial distributions of defects indicate that the interface between inclusions and the host tend to amplify and restrict the defect formation to the inclusions themselves, when compared to cascades in pure ferrite and pure carbide cells. (C) 2016 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (