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331.
In the present study we investigated long-term memory for unpleasant, neutral and spider pictures in 15 spider-fearful and 15 non-fearful control individuals using behavioral and electrophysiological measures. During the initial (incidental) encoding, pictures were passively viewed in three separate blocks and were subsequently rated for valence and arousal. A recognition memory task was performed one week later in which old and new unpleasant, neutral and spider pictures were presented. Replicating previous results, we found enhanced memory performance and higher confidence ratings for unpleasant when compared to neutral materials in both animal fearful individuals and controls. When compared to controls high animal fearful individuals also showed a tendency towards better memory accuracy and significantly higher confidence during recognition of spider pictures, suggesting that memory of objects prompting specific fear is also facilitated in fearful individuals. In line, spider-fearful but not control participants responded with larger ERP positivity for correctly recognized old when compared to correctly rejected new spider pictures, thus showing the same effects in the neural signature of emotional memory for feared objects that were already discovered for other emotional materials. The increased fear memory for phobic materials observed in the present study in spider-fearful individuals might result in an enhanced fear response and reinforce negative beliefs aggravating anxiety symptomatology and hindering recovery. 相似文献
332.
Pawel Borun Lukasz Kubaszewski Tomasz Banasiewicz Jaroslaw Walkowiak Marzena Skrzypczak-Zielinska Marta Kaczmarek-Rys Andrzej Plawski 《Human genetics》2014,133(5):535-545
Efficient and cost-effective screening for DNA sequence changes, both small mutations and copy number variations (CNVs), is a crucial aspect for routine genetic diagnostics as well as for basic research. In this study we present a development and evaluation of comparative-high resolution melting (C-HRM), a new approach for the simultaneous screening of small DNA changes and gene CNVs. In contrast to other methods, relative quantification in C-HRM is based on the results obtained during the melting process and calculations of the melting peak height ratio in the multiplex reaction. Validation of the method was conducted on DNA samples from 50 individuals from Duchenne muscular dystrophy (DMD) families, 50 probands diagnosed with familial adenomatous polyposis and a control group of 36 women and 36 men. The results of analyses conducted on fragments of the DMD and APC genes correspond completely (100 %) with the results of previous studies. C-HRM sensitivity in CNV detection was assessed through the analysis of mixed DNA samples with different proportions of a deletion carrier and wild type control. The results are presented as a linear regression with R 2 of 0.9974 and imply the capability of the method to detect mosaics. C-HRM is an attractive and powerful alternative to other methods of point mutations and CNV detection with 100 % accuracy in our studied group. 相似文献
333.
Anna Jastrzebska Artur Kaminski Ewelina Grazka Joanna Marowska Jaroslaw Sadlo Grzegorz Gut Izabela Uhrynowska-Tyszkiewicz 《Cell and tissue banking》2014,15(3):413-428
Ionizing radiation has been found to induce stable defects in the crystalline lattice of bone mineral hydroxyapatite, defined as CO2 ? radical ions possessing spins. The purpose of our study was to evaluate CO2 ? radical ions induced in non-defatted or defatted human compact bone by gamma radiation (G) and accelerated electron beam (EB), applied with two doses at different temperatures. Moreover, the potential effect of free radical ion formation on mechanical parameters of compact bone, tested under compression in the previous studies, was evaluated. Bone rings from femoral shafts of six male donors (age 51 ± 3 years) were collected and assigned to sixteen experimental groups according to different processing methods (non-defatted or defatted), G and EB irradiation dose (25 or 35 kGy), and irradiation temperature [ambient temperature (AT) or dry ice (DI)]. Untreated group served as control. Following grinding under LN2 and lyophilization, CO2 ? radical ions in bone powder were measured by electron paramagnetic resonance spectrometry. We have found that irradiation of bone with G and EB induces formation of enormous amounts of CO2 ? radical ions, absent from native tissue. Free radical ion formation was dose-dependent when irradiation was performed at AT, and significantly lower in EB as compared to G-irradiated groups. In contrast, no marked effect of dose was observed when deep-frozen (DI) bone samples were irradiated with G or EB, and free radical ion numbers seemed to be slightly higher in EB-irradiated groups. Irradiation at AT induced much higher quantities of CO2 ? radical ions then on DI. That effect was more pronounced in G-irradiated bone specimens, probably due to longer exposure time. Similarly, bone defatting protective effect on free radical ion formation was found only in groups irradiated for several hours with gamma radiation at ambient temperature. Ambient irradiation temperature together with exposure time seem to be key parameters promoting CO2 ? radical ion formation in bone mineral and may mask the opposite effect of defatting and the possible effect of irradiation type. Significant weak negative correlations between CO2 ? radical ion number and some mechanical properties of compact bone rings (Young’s modulus and ultimate stress) were found. 相似文献
334.
Szymon J. Ciesielski Brenda Schilke Jaroslaw Marszalek Elizabeth A. Craig 《Molecular biology of the cell》2016,27(7):1060-1068
Iron–sulfur (Fe–S) clusters, essential protein cofactors, are assembled on the mitochondrial scaffold protein Isu and then transferred to recipient proteins via a multistep process in which Isu interacts sequentially with multiple protein factors. This pathway is in part regulated posttranslationally by modulation of the degradation of Isu, whose abundance increases >10-fold upon perturbation of the biogenesis process. We tested a model in which direct interaction with protein partners protects Isu from degradation by the mitochondrial Lon-type protease. Using purified components, we demonstrated that Isu is indeed a substrate of the Lon-type protease and that it is protected from degradation by Nfs1, the sulfur donor for Fe–S cluster assembly, as well as by Jac1, the J-protein Hsp70 cochaperone that functions in cluster transfer from Isu. Nfs1 and Jac1 variants known to be defective in interaction with Isu were also defective in protecting Isu from degradation. Furthermore, overproduction of Jac1 protected Isu from degradation in vivo, as did Nfs1. Taken together, our results lead to a model of dynamic interplay between a protease and protein factors throughout the Fe–S cluster assembly and transfer process, leading to up-regulation of Isu levels under conditions when Fe–S cluster biogenesis does not meet cellular demands. 相似文献
335.
336.
Bozena Dziadek Justyna Gatkowska Jaroslaw Dziadek Henryka Dlugonska 《Experimental parasitology》2009,123(1):81-8846
Toxoplasmosis is a one of the most world-wide spread zoonosis representing a very serious clinical and veterinary problem. In the presented study, we evaluated the protective efficacy of a combined recombinant ROP2 and ROP4 subunit vaccine in a chronic Toxoplasma gondii infection in mice. The recombinant ROP2 (rROP2) and ROP4 (rROP4) proteins were cloned and expressed in Escherichia coli and then used for the immunization of C3H/HeJ mice. Both antigens generated a strong systemic mixed Th1/Th2 response polarized towards IgG1 antibody isotype. In contrast to rROP2 stimulating only the specific IL-2 release, rROP4 and crude toxoplasma lysate antigen (TLA) used as a source of native forms of the parasite proteins induced significant proliferation of splenocytes and specific production of IFN-γ as well as IL-2, the Th1-type cytokines. Challenge of rROP2 and rROP4-vaccinated mice with cysts of low virulent T. gondii DX strain resulted in a partial protection effect with a significantly lower brain parasites load when compared with control animals. In the immunized group of mice the brain cysts number was reduced by nearly 46% as was determined in two independent experiments. These results suggest that, similar to ROP2, rhoptry protein ROP4 could be a very good candidate for future anti-T. gondii multicomponent vaccine based on the recombinant forms of different parasite proteins. 相似文献
337.
Pitcher RS Tonkin LM Daley JM Palmbos PL Green AJ Velting TL Brzostek A Korycka-Machala M Cresawn S Dziadek J Hatfull GF Wilson TE Doherty AJ 《Molecular cell》2006,23(5):743-748
Ku-dependent nonhomologous end joining (NHEJ) is a double-strand break repair process conserved in all branches of cellular life but has not previously been implicated in the DNA metabolic processes of viruses. We identified Ku homologs in Corndog and Omega, two related mycobacteriophages of Mycobacterium smegmatis. These proteins formed homodimers and bound DNA ends in a manner identical to other Ku's and stimulated joining of ends by the host NHEJ DNA ligase (LigD). Omega and Corndog are unusual in having short 4 base cos ends that would not be expected to self-anneal and would therefore require NHEJ during phage genome circularization. Consistently, M. smegmatis LigD null strains are entirely and selectively unable to support infection by Corndog or Omega, with concomitant failure of genome circularization. These results establish a new paradigm for sequestration of the host cell NHEJ process by bacteriophage and provide a framework for understanding similar transactions in eukaryotic viral infections. 相似文献
338.
Electroporation-mediated interleukin-10 overexpression in skeletal muscle reduces acute rejection in rat cardiac allografts 总被引:2,自引:0,他引:2
Tavakoli R Gazdhar A Pierog J Bogdanova A Gugger M Pringle IA Gill DR Hyde SC Genoni M Schmid RA 《The journal of gene medicine》2006,8(2):242-248
OBJECTIVES: Human interleukin 10 (hIL-10) may reduce acute rejection after organ transplantation. Our previous data shows that electroporation-mediated transfer of plasmid DNA to peripheral muscle enhances gene transduction dramatically. This study was designed to investigate the effect of electroporation-mediated overexpression of hIL-10 on acute rejection of cardiac allografts in the rat. METHODS: The study was designed to evaluate the effect of hIL-10 gene transfer on (a) early rejection pattern and (b) graft survival. Gene transfer was achieved by intramuscular (i.m.) injection into the tibialis anterior muscle of Fischer (F344) male recipients followed by electroporation 24 h prior to transplantation. Heterotopic cardiac transplantation was performed from male Brown Norway rat to F344. Four groups were studied (n = 6). Treated animals in groups B1 and B2 received 2.5 microg of pCIK hIL-10 and control animals in groups A1 and A2 distilled water. Graft function was assessed by daily palpation. Animals from group A1 were sacrificed at the cessation of the heart beat of the graft and those in group B1 were sacrificed at day 7; blood was taken for ELISA measurement of hIL-10 and tissue for myeloperoxidase (MPO) measurement and histological assessment. To evaluate graft survival, groups A2 and B2 were sacrificed at cessation of the heart beat of the graft. RESULTS: Histological examination revealed severe rejection (IIIB-IV) in group A1 in contrast to low to moderate rejection (IA-IIIA) in group B1 (p = 0.02). MPO activity was significantly lower in group B1 compared to group A1 (18 +/- 7 vs. 32 +/- 14 mU/mg protein, p = 0.05). Serum hIL-10 levels were 46 +/- 13 pg/ml in group B1 vs. 0 pg/ml in group A1. At day 7 all heart allografts in the treated groups B1 and B2 were beating, whereas they stopped beating at 5 +/- 2 days in groups A1 and A2 vs. 14 +/- 2 days in group B2 (p = 0.0012). CONCLUSIONS: Electroporation-mediated intramuscular overexpression of hIL-10 reduces acute rejection and improves survival of heterotopic heart allografts in rats. This study demonstrates that peripheral overexpression of specific genes in skeletal muscle may reduce acute rejection after whole organ transplantation. 相似文献
339.
Bosman LW Hartmann J Barski JJ Lepier A Noll-Hussong M Reichardt LF Konnerth A 《Brain Cell Biology》2006,35(1):87-101
The receptor tyrosine kinase TrkB and its ligands, brain-derived neurotrophic factor (BDNF) and neurotrophin-4/5 (NT-4/5),
are critically important for growth, survival and activity-dependent synaptic strengthening in the central nervous system.
These TrkB-mediated actions occur in a highly cell-type specific manner. Here we report that cerebellar Purkinje cells, which
are richly endowed with TrkB receptors, develop a normal morphology in trkB-deficient mice. Thus, in contrast to other types of neurons, Purkinje cells do not need TrkB for dendritic growth and spine
formation. Instead, we find a moderate delay in the maturation of GABAergic synapses and, more importantly, an abnormal multiple
climbing fiber innervation in Purkinje cells in trkB-deficient mice. Thus, our results demonstrate an involvement of TrkB receptors in synapse elimination and reveal a new role
for receptor tyrosine kinases in the brain.
Electronic Supplementary Materials Supplementary Materials is available in the online version of this article at 相似文献
340.
González-Martínez SC Burczyk J Nathan R Nanos N Gil L Alía R 《Molecular ecology》2006,15(14):4577-4588
Understanding population-scale processes that affect allele frequency changes across generations is a long-standing interest in genetic, ecological and evolutionary research. In particular, individual differences in female reproductive success and the spatial scale of gene flow considerably affect evolutionary change and patterns of local selection. In this study, a recently developed maximum-likelihood (ML) method based on established offspring, the Seedling Neighbourhood Model , was applied and exponentially shaped dispersal kernels were fitted to both genetic and ecological data in a widespread Mediterranean pine, Pinus pinaster Aiton. The distribution of female reproductive success in P. pinaster was very skewed (about 10% of trees mothered 50% of offspring) and significant positive female selection gradients for diameter (γ = 0.7293) and cone crop (γ = 0.4524) were found. The selective advantage of offspring mothered by bigger trees could be due to better-quality seeds. These seeds may show more resilience to severe summer droughts and microsite variation related to water and nutrient availability. Both approaches, ecological and of parentage, consistently showed a long-distance dispersal component in saplings that was not found in dispersal kernels based on seed shadows, highlighting the importance of Janzen-Connell effects and microenvironmental variation for survival at early stages of establishment in this Mediterranean key forest tree. 相似文献