1,689 research outputs found
Effects of C and Al on hydrogen embrittlement mechanism in medium Mn-Ni steels
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Analyzing the advantages of subcutaneous over transcutaneous electrical stimulation for activating brainwaves
Transcranial electrical stimulation (TES) is a widely accepted neuromodulation modality for treating brain disorders. However, its clinical efficacy is fundamentally limited due to the current shunting effect of the scalp and safety issues. A newer electrical stimulation technique called subcutaneous electrical stimulation (SES) promises to overcome the limitations of TES by applying currents directly at the site of the disorder through the skull. While SES seems promising, the electrophysiological effect of SES compared to TES is still unknown, thus limiting its broader application. Here we comprehensively analyze the SES and TES to demonstrate the effectiveness and advantages of SES. Beagles were bilaterally implanted with subdural strips for intracranial electroencephalography and electric field recording. For the intracerebral electric field prediction, we designed a 3D electromagnetic simulation framework and simulated TES and SES. In the beagle model, SES induces three to four-fold larger cerebral electric fields compared to TES, and significant changes in power ratio of brainwaves were observed only in SES. Our prediction framework suggests that the field penetration of SES would be several-fold larger than TES in human brains. These results demonstrate that the SES would significantly enhance the neuromodulatory effects compared to conventional TES and overcome the TES limitations.11Ysciescopu
Mechanisms of Cross-protection by Influenza Virus M2-based Vaccines
Current influenza virus vaccines are based on strain-specific surface glycoprotein hemagglutinin (HA) antigens and effective only when the predicted vaccine strains and circulating viruses are well-matched. The current strategy of influenza vaccination does not prevent the pandemic outbreaks and protection efficacy is reduced or ineffective if mutant strains emerge. It is of high priority to develop effective vaccines and vaccination strategies conferring a broad range of cross protection. The extracellular domain of M2 (M2e) is highly conserved among human influenza A viruses and has been utilized to develop new vaccines inducing cross protection against different subtypes of influenza A virus. However, immune mechanisms of cross protection by M2e-based vaccines still remain to be fully elucidated. Here, we review immune correlates and mechanisms conferring cross protection by M2e-based vaccines. Molecular and cellular immune components that are known to be involved in M2 immune-mediated protection include antibodies, B cells, T cells, alveolar macrophages, Fc receptors, complements, and natural killer cells. Better understanding of protective mechanisms by immune responses induced by M2e vaccination will help facilitate development of broadly cross protective vaccines against influenza A virus
Leukotactin-1/CCL15-induced chemotaxis signaling through CCR1 in HOS cells
AbstractLeukotactin-1 (Lkn-1)/CCL15 is a recently cloned CC-chemokine that binds to the CCR1 and CCR3. Although Lkn-1 has been known to function as a chemoattractant for neutrophils, monocytes and lymphocytes, its cellular mechanism remains unclear. To understand the mechanism of Lkn-1-induced chemotaxis signaling, we examined the chemotactic activities of human osteogenic sarcoma cells expressing CCR1 in response to Lkn-1 using inhibitors of signaling molecules. Inhibitors of Gi/Go protein, phospholipase C (PLC) and protein kinase Cδ (PKCδ) inhibited the chemotactic activity of Lkn-1 indicating that Lkn-1-induced chemotaxis signal is transduced through Gi/Go protein, PLC and PKCδ. The activities of PLC and PKCδ were also enhanced by Lkn-1 stimulation. Chemotactic activity of Lkn-1 was inhibited by the treatment of cycloheximide and actinomycin D suggesting that newly synthesized proteins are needed for chemotaxis. Nuclear factor-κB (NF-κB) inhibitor reduced chemotactic activity of Lkn-1. DNA binding activity of NF-κB was also enhanced by Lkn-1 stimulation. These results suggest that Lkn-1 transduces the signal through Gi/Go protein, PLC, PKCδ, NF-κB and newly synthesized proteins for chemotaxis
Recombinant Influenza Virus Carrying the Conserved Domain of Respiratory Syncytial Virus (RSV) G Protein Confers Protection Against RSV Without Inflammatory Disease
Respiratory syncytial virus (RSV) is one of the most important causes for viral lower respiratory tract disease in humans. There is no licensed RSV vaccine. Here, we generated recombinant influenza viruses (PR8/RSV. HA-G) carrying the chimeric constructs of hemagglutinin (HA) and central conserved-domains of the RSV G protein. PR8/RSV.HA-G virus showed lower pathogenicity without compromising immunogenicity in mice. Single intranasal inoculation of mice with PR8/RSV.HA-G induced IgG2a isotype dominant antibodies and RSV neutralizing activity. Mice with single intranasal inoculation of PR8/RSV.HA-G were protected against RSV infection as evidenced by significant reduction of lung viral loads to a detection limit upon RSV challenge. PR8/RSV.HA-G inoculation of mice did not induce pulmonary eosinophilia and inflammation upon RSV infection. These findings support a concept that recombinant influenza viruses carrying the RSV G conserved-domain can be developed as a promising RSV vaccine candidate without pulmonary disease
The long-term evaluation of the prognosis of implants with acid-etched surfaces sandblasted with alumina: a retrospective clinical study
Background
The aim of this study was to evaluate the long-term clinical stability of implants with acid-etched surfaces sandblasted with alumina using retrospective analyses of the survival rate, success rate, primary and secondary stability, complications, and marginal bone loss of the implants.
Methods
Patients who had implants placed (TS III SA, SS II SA, SS III SA, and U III SA) with SA surfaces from Osstem (Osstem Implant Co., Busan, Korea) at the Seoul National University Bundang Hospital, from January 2008 to December 2010 were selected for the study. Patients medical records and radiographs (panorama, periapical view) were retrospectively analyzed to investigate sex, age, location of implantation, diameter, and length of the implants, initial and secondary stability, presence of bone grafting, types of bone grafting and membranes, early and delayed complications, marginal bone loss, and implant survival rate.
Results
Ninety-six implants were placed in 45 patients. Five implants were removed during the follow-up period for a total survival rate of 94.8%. There were 14 cases of complications, including 6 cases of early complications and 8 cases of delayed complications. All five implants that failed to survive were included in the early complications. The survival of implants was significantly associated with the occurrence of complications and the absorption of bone greater than 1 mm within 1 year after prosthetic completion. In addition, the absorption of bone greater than 1 mm within 1 year after prosthetic completion was significantly associated with the occurrence of complications, primary stability, and implant placement method. Five cases that failed to survive were all included in the early complications criteria such as infection, failure of initial osseointegration, and early exposure of the fixture.
Conclusions
Of the 96 cases, 5 implants failed resulting in a 94.8% survival rate. The failed implants were all cases of early complications such as infection, failure of initial osseointegration, and early exposure of the fixtures. Peri-implantitis was mostly addressed through conservative and/or surgical treatment and resulted in very low prosthetic complications. Therefore, if preventive measures are taken to minimize initial complications, the results can be very stable
Experimental Study on the Acellular Demal Matrix Graft for the Root Coverage in Dog
Mucogingival surgery is a plastic surgical procedure designed to correct defects in the morphology, position, and dimensions of the gingiva surrounding the teeth. Many surgical techniques have been reported in mucogingival surgery. Since these procedures also include the soft tissue esthetic approach, the term periodontal plastic surgery has been proposed to be more appropriate.1 Root coverage is a procedure that falls with this definition, and it has attracted more interest than others
Long-Term Bidirectional Association Between Asthma and Attention Deficit Hyperactivity Disorder: A Big Data Cohort Study
BACKGROUND: Previous studies have argued that attention deficit hyperactivity disorder (ADHD) is associated with asthma. However, reliable evidence to verify this association has not yet been reported.
OBJECTIVES: To investigate the bidirectional association between asthma and ADHD through a 12-year big data cohort study.
METHODS: The independent variable group was extracted from 3.5 million individuals randomly sampled by the National Health Insurance Service (NHIS). In Study 1, the incidence of ADHD according to asthma was evaluated, while in Study 2, the incidence of asthma according to ADHD was analyzed. Propensity score (PS) matching with several variables was used to obtain a control group.
MEASUREMENTS AND MAIN RESULTS: In Study 1, the asthma group included 131,937 individuals and the non-asthma group included 131,937 individuals. The adjusted hazard ratio (aHR) for ADHD in the asthma group was 1.17 [95% confidence interval (CI): 1.11-1.23]. In subgroup analysis, the aHRs for ADHD of individuals in the subgroups male sex, 0-5 years old, 6-10 years old, atopic dermatitis, allergic rhinitis, Charlson comorbidity index (CCI) 1, and CCI \u3e 2 were significant (aHR: 2.83, 1.70, 1.79, 1.09, 1.15, 1.06, and 1.49, respectively). In Study 2, ADHD was found to significantly affect asthma in all age groups (aHRs of the subgroups 0∼60 and 0∼17 years old were 1.10 and 1.09, respectively). In the 0∼17 years old subgroup, the association of ADHD with asthma was greater with younger age (aHRs of the subgroups 0∼5 and 6∼10 years old were 2.53 and 1.54, respectively).
CONCLUSION: From long-term follow-up, the incidence of ADHD was 1.17 times higher in the asthma group than in the control group. The incidence of asthma was 1.10 times higher in the ADHD group than in the control group. Asthma and ADHD have a bidirectional relationship, and childhood asthma and ADHD should be rigorously managed
Curcumin induces expression of 15-hydroxyprostaglandin dehydrogenase in gastric mucosal cells and mouse stomach in vivo: AP-1 as a potential target
15-Hydroxyprostaglandin dehydrogenase (15-PGDH) catalyzes the conversion of oncogenic prostaglandin E-2 to non-tumerigenic 15-keto prostaglandin E-2. In the present study, we found that curcumin, a yellow coloring agent present in the rhizome of Curcuma Tonga Linn (Zingiberaceae), induced expression of 15-PGDH at the both transcriptional and translational levels in normal rat gastric mucosal cells. By using deletion constructs of 15-PGDH promoter, we were able to demonstrate that activator protein-1 (AP-1) is the principal transcription factor responsible for regulating curcumin-induced 15-PGDH expression. Curcumin enhanced the expression of c-jun and cFos that are functional subunits of AP-1, in the nuclear fraction of cells. Silencing of c-jun suppressed curcumin-induced expression of 15-PGDH. Moreover, the chromatin immunoprecipitation assay revealed curcumin-induced binding of c-Jun to the AP-1 consensus sequence present in the 15-PGDH promoter. Curaimin increased phosphorylation of ERK1/2 and JNK. and pharmacologic inhibition of these kinases abrogated the curcumin-induced phosphorylation of clun and 15-PGDH expression. In contrast, tetrahydrocurcumin which lacks the alpha,beta-unsaturated carbonyl group failed to induce 15-PGDH expression, suggesting that the electrophilic carbonyl group of curcumin is essential for its induction of 15-PGDH expression. Curcumin restored the expression of 15-PGDH which is down-regulated by Helicobater pylori through suppression of DNA methyltransferase 1. In addition, oral administration of curcumin increased the expression of 15-PGDH and its regulators such as p-ERK1/2, p-JNK and c-Jun in the mouse stomach. Taken together, these findings suggest that curcumin-induced upregulation of 15-PGDH may contribute to chemopreventive effects of this phytochemical on inflammation-associated gastric carcinogenesis. (C) 2020 Elsevier Inc. All rights reserved.
17β-estradiol reduces inflammation and modulates antioxidant enzymes in colonic epithelial cells
Background/Aims: Estrogen is known to have protective effect in colorectal cancer development. The aims of this study are to investigate whether estradiol treatment reduces inflammation in CCD841CoN, a female human colonic epithelial cell line and to uncover underlying mechanisms of estradiol effects. Methods: 17 beta-Estradiol (E2) effect was measured by Western blot after inducing inflammation of CCD841CoN by tumor necrosis factor alpha (TNF-alpha). Expression levels of estrogen receptor alpha (ER alpha) and beta (ER beta), cyclooxygenase-2 (COX-2), nuclear factor-kappa B (NF-kappa B), heme oxygenase-1 (HO-1), and NAD(P)H-quinone oxidoreductase-1 (NQO-1) were also evaluated. Results: E2 treatment induced expression of ERO but did not increase that of ER alpha. E2 treatment for 48 hours significantly elevated the expression of anti-oxidant enzymes, HO-1 and NQO-1. TNF-alpha treatment significantly increased the level of activated NF-kappa B (p < 0.05), and this increase was significantly suppressed by treatment of to nM of E2 (p < 0.05). E2 treatment ameliorated TNF-alpha-induced COX-2 expression and decrease of HO-1 expression. 4-(2-phenyl-5,7-bis(trifluoromethyl) pyrazolo(1,5-a)pyrimidin-3-yl)phenol (PHTPP), antagonist of ER beta, removed the inhibitory effect of E2 in the TNF-alpha-induced COX-2 expression (p = 0.05). Conclusions: Estrogen seems to inhibit inflammation in female human colonic epithelial cell lines, through down-regulation of NF-kappa B and COX-2 expression and induction of anti-oxidant enzymes such as HO-1 and NQO-1.
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