39 research outputs found

    5-Methylcytosine and 5-Hydroxymethylcytosine Spatiotemporal Profiles in the Mouse Zygote

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    Background: In the mouse zygote, DNA methylation patterns are heavily modified, and differ between the maternal and paternal pronucleus. Demethylation of the paternal genome has been described as an active and replication-independent process, although the mechanisms responsible for it remain elusive. Recently, 5-hydroxymethylcytosine has been suggested as an intermediate in this demethylation. Methodology/principal findings: In this study, we quantified DNA methylation and hydroxymethylation in both pronuclei of the mouse zygote during the replication period and we examined their patterns on the pericentric heterochromatin using 3D immuno-FISH. Our results demonstrate that 5-methylcytosine and 5-hydroxymethylcytosine localizations on the pericentric sequences are not complementary; indeed we observe no enrichment of either marks on some regions and an enrichment of both on others. In addition, we show that DNA demethylation continues during DNA replication, and is inhibited by aphidicolin. Finally, we observe notable differences in the kinetics of demethylation and hydroxymethylation; in particular, a peak of 5-hydroxymethylcytosine, unrelated to any change in 5-methylcytosine level, is observed after completion of replication. Conclusion/significance: Together our results support the already proposed hypothesis that 5-hydroxymethylcytosine is not a simple intermediate in an active demethylation process and could play a role of its own during early development

    The structure and regulation of Cullin 2 based E3 ubiquitin ligases and their biological functions

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    Immunoglobulin, glucocorticoid, or combination therapy for multisystem inflammatory syndrome in children: a propensity-weighted cohort study

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    Background Multisystem inflammatory syndrome in children (MIS-C), a hyperinflammatory condition associated with SARS-CoV-2 infection, has emerged as a serious illness in children worldwide. Immunoglobulin or glucocorticoids, or both, are currently recommended treatments. Methods The Best Available Treatment Study evaluated immunomodulatory treatments for MIS-C in an international observational cohort. Analysis of the first 614 patients was previously reported. In this propensity-weighted cohort study, clinical and outcome data from children with suspected or proven MIS-C were collected onto a web-based Research Electronic Data Capture database. After excluding neonates and incomplete or duplicate records, inverse probability weighting was used to compare primary treatments with intravenous immunoglobulin, intravenous immunoglobulin plus glucocorticoids, or glucocorticoids alone, using intravenous immunoglobulin as the reference treatment. Primary outcomes were a composite of inotropic or ventilator support from the second day after treatment initiation, or death, and time to improvement on an ordinal clinical severity scale. Secondary outcomes included treatment escalation, clinical deterioration, fever, and coronary artery aneurysm occurrence and resolution. This study is registered with the ISRCTN registry, ISRCTN69546370. Findings We enrolled 2101 children (aged 0 months to 19 years) with clinically diagnosed MIS-C from 39 countries between June 14, 2020, and April 25, 2022, and, following exclusions, 2009 patients were included for analysis (median age 8·0 years [IQR 4·2–11·4], 1191 [59·3%] male and 818 [40·7%] female, and 825 [41·1%] White). 680 (33·8%) patients received primary treatment with intravenous immunoglobulin, 698 (34·7%) with intravenous immunoglobulin plus glucocorticoids, 487 (24·2%) with glucocorticoids alone; 59 (2·9%) patients received other combinations, including biologicals, and 85 (4·2%) patients received no immunomodulators. There were no significant differences between treatments for primary outcomes for the 1586 patients with complete baseline and outcome data that were considered for primary analysis. Adjusted odds ratios for ventilation, inotropic support, or death were 1·09 (95% CI 0·75–1·58; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids and 0·93 (0·58–1·47; corrected p value=1·00) for glucocorticoids alone, versus intravenous immunoglobulin alone. Adjusted average hazard ratios for time to improvement were 1·04 (95% CI 0·91–1·20; corrected p value=1·00) for intravenous immunoglobulin plus glucocorticoids, and 0·84 (0·70–1·00; corrected p value=0·22) for glucocorticoids alone, versus intravenous immunoglobulin alone. Treatment escalation was less frequent for intravenous immunoglobulin plus glucocorticoids (OR 0·15 [95% CI 0·11–0·20]; p<0·0001) and glucocorticoids alone (0·68 [0·50–0·93]; p=0·014) versus intravenous immunoglobulin alone. Persistent fever (from day 2 onward) was less common with intravenous immunoglobulin plus glucocorticoids compared with either intravenous immunoglobulin alone (OR 0·50 [95% CI 0·38–0·67]; p<0·0001) or glucocorticoids alone (0·63 [0·45–0·88]; p=0·0058). Coronary artery aneurysm occurrence and resolution did not differ significantly between treatment groups. Interpretation Recovery rates, including occurrence and resolution of coronary artery aneurysms, were similar for primary treatment with intravenous immunoglobulin when compared to glucocorticoids or intravenous immunoglobulin plus glucocorticoids. Initial treatment with glucocorticoids appears to be a safe alternative to immunoglobulin or combined therapy, and might be advantageous in view of the cost and limited availability of intravenous immunoglobulin in many countries. Funding Imperial College London, the European Union's Horizon 2020, Wellcome Trust, the Medical Research Foundation, UK National Institute for Health and Care Research, and National Institutes of Health

    Fully doped oligomers of emeraldine salt: Polaronic versus bipolaronic configuration

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    Calculations for model oligomers of the emeraldine salt with UBLYP/6-31G*/PCM are performed. The models differ in number of monomers, in the position of the counterions (Cl-), and in multiplicity. The molecular features affected most prominently by the protonation, namely, structure, energetics, and electron and spin density partitioning are analyzed. The results show unequivocally that the studied molecular characteristics are essentially size independent. The octamer profiles of all parameters are repeated in the dodecamer and the hexadecamer. The bipolaronic forms are energetically more favorable than the polaronic ones within the chosen protocol. The electronic structure in the intermediate multiplicities differs from the bipolaronic and polaronic periodicity. The geometrical changes and electron density redistribution upon increase of multiplicity illustrate the pathway of intramolecular bipolaron-polaron conversion. The orbital analysis rationalizes the observed behavior of the oligomers. © 2011 American Chemical Society

    Fully doped oligomers of emeraldine salt: Polaronic versus bipolaronic configuration

    No full text
    Calculations for model oligomers of the emeraldine salt with UBLYP/6-31G*/PCM are performed. The models differ in number of monomers, in the position of the counterions (Cl-), and in multiplicity. The molecular features affected most prominently by the protonation, namely, structure, energetics, and electron and spin density partitioning are analyzed. The results show unequivocally that the studied molecular characteristics are essentially size independent. The octamer profiles of all parameters are repeated in the dodecamer and the hexadecamer. The bipolaronic forms are energetically more favorable than the polaronic ones within the chosen protocol. The electronic structure in the intermediate multiplicities differs from the bipolaronic and polaronic periodicity. The geometrical changes and electron density redistribution upon increase of multiplicity illustrate the pathway of intramolecular bipolaron-polaron conversion. The orbital analysis rationalizes the observed behavior of the oligomers. © 2011 American Chemical Society

    NEW FORMYL-PEPTIDES, AS STIMULATOR OF NON-SPECIFIC ORGANISM RESISTANCE AGAINST MYCOBACTERIA

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    Introduction. The key element in the formation of tuberculosis infection (TI) is the inability of alveolar macrophage to complete phagocytosis of mycobacteria absorbed by them, that caused by both features of the pathogens biology and the tissue macrophages. It is known, that M. tuberculosis is capable long-term persistence and proliferation in alveolar macrophage cytoplasm because of high stability of them cell walls to the lysosomal enzymes action. Mainly, the phenomenon of granulomatous reaction, inherent of tuberculosis (TB), reflects the inadequacy in elimination of tuberculosis pathogen of alveolar macrophages. Thus, the inclusion of agents that can activate completed phagocytosis of mycobacteria by alveolar macrophages, in the base of anti-TB therapy is a promising direction in the prevention of latent tuberculosis reactivation. Materials and Method. The ability of formyl-peptides activate the completeness of mycobacteria phagocytosis by alveolar macrophages absorbed by them were evaluated in vitro. For reaching the aim of the study we had used a broncho-alveolar lavage obtained by white laboratory male mice 2 months of age. As a comparison drug we used the officinal preparation "Liasten". To determine the lysosomal activity by the presence of peroxidase was treated with acridine orange causing selective staining red lysosomes. Acid phosphatase activity was studied using azocoupling reaction for staining granules in the cytoplasm blue or purple. Results are expressed as mean cytochemical coefficient (LZC). Results and discussion. Incubation of alveolar macrophages and formyl-peptides leads to a significant increase the index of mycobacteria phagocytosis completeness for vaccine strains - (1,70 ± 0,31) and (1,20 ± 0,22), respectively, (p <0.05). The standard medication - Liasten - also increased the "killing" ability of tissue macrophages compared to control: (1,8 ± 0,25) and (1,20 ± 0,22), respectively, (p <0.05). Lysosomal activity of alveolar macrophages exposed formyl-peptides significantly increased in comparison with the control - (97,80 ± 5,1) and (80,9 ± 4,3) acridine orange-positive cells, respectively, (p <0.05). However, the effect of formyl-peptides on lysosomal activity of macrophages did not exceed the reference drug action - (97,80 ± 5,1) and (95,72 ± 5,3) acridine orange-positive cells, respectively, without significant differences. Incubation with formyl-peptides resulted in a significant increase of LZC of acid phosphatase in macrophages - (2,08 ± 0,20) and (1,59 ± 0,14), respectively, (p <0.05). Significant differences between the content of this enzyme in macrophages when exposed formyl-peptides and the reference drug were not detected. Conclusion. As a result the co-incubation of alveolar macrophages and new formil-peptides activates BCG phagocytosis completeness. Also, there is the influence of the studied substances under significant lysosomal activity and increase the content of acid phosphatase in macrophages isolated from broncho-alveolar lavage in comparison with the control. The level of functional activity stimulation of phagocytes under the influence of formyl-peptide is the same, that we registered after the Liasten administration. It has indicating prospects of the medicinal preparation creation on the formyl-peptides basis, which stimulates the organism non-specific resistance

    Pilot study of intratumoral injection of recombinant heat shock protein 70 in the treatment of malignant brain tumors in children

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    Maxim A Shevtsov,1,2 Alexander V Kim,2 Konstantin A Samochernych,2 Irina V Romanova,3 Boris A Margulis,1 Irina V Guzhova,1 Igor V Yakovenko,2 Alexander M Ischenko,4 William A Khachatryan2 1Institute of Cytology of the Russian Academy of Sciences, 2AL Polenov Russian Research Scientific Institute of Neurosurgery, 3IM Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences, 4Research Institute of Highly Pure Biopreparations, St Petersburg, Russian Federation Abstract: Intratumoral injections of recombinant heat shock protein (Hsp)70 were explored for feasibility in patients with brain tumors. Patients aged 4.5&ndash;14 years with untreated newly diagnosed tumors (n=12) were enrolled. After tumor resection, five injections of recombinant Hsp70 (total 2.5 mg) were administered into the resection cavity through a catheter. Before administration of Hsp70 and after the last injection, specific immune responses to the autologous tumor lysate were evaluated using the delayed-type hypersensitivity test. Further, peripheral blood was monitored to identify possible changes in lymphocyte subpopulations, cytokine levels, and the cytolytic activity of natural killer cells. The follow-up period in this trial was 12 months. Intratumoral injections of Hsp70 were well tolerated by patients. One patient had a complete clinical response documented by radiologic findings and one patient had a partial response. A positive delayed-type hypersensitivity test was observed in three patients. In peripheral blood, there was a shift from cytokines provided by Th2 cells toward cytokines of a Th1-cell-mediated response. These data corresponded to changes in lymphocyte subpopulations. Immunosuppressive T-regulatory cell levels were also reduced after injection of Hsp70, as well as production of interleukin-10. The cytolytic activity of natural killer cells was unchanged. The present study demonstrates the feasibility of intratumoral delivery of recombinant Hsp70 in patients with cancer. Further randomized clinical trials are recommended to assess the optimum dose of the chaperone, the treatment schedule, and clinical efficacy. Keywords: heat shock protein 70, malignant brain tumors, immunotherapy, glioblastom
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