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1.
Org Lett ; 26(10): 2034-2038, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38486497

RESUMO

Tuberculosis (TB) is one of the most dreadful diseases, killing more than 3 million humans annually. M. tuberculosis (MTb) is the causative agent for TB and has a thick and waxy cell wall, making it an attractive target for immunological studies. In this study, a heptamannopyranoside containing 1 → 2 and 1 → 6 α-mannopyranosidic linkages has been explored for the immunological evaluations. The conjugation-ready heptamannopyranoside was synthesized by exploiting the salient features of recently discovered [Au]/[Ag]-glycosidation of ethynylcyclohexyl glycosyl carbonate donors. The glycan was conjugated to the ESAT6, an early secreted protein of MTb for further characterization as a potential subunit vaccine candidate.


Assuntos
Mycobacterium tuberculosis , Tuberculose , Humanos , Tuberculose/metabolismo , Carbonatos , Catálise
2.
J Biomol NMR ; 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38407675

RESUMO

A large proportion of human proteins contain post-translational modifications that cannot be synthesized by prokaryotes. Thus, mammalian expression systems are often employed to characterize structure/function relationships using NMR spectroscopy. Here we define the selective isotope labeling of secreted, post-translationally modified proteins using human embryonic kidney (HEK)293 cells. We determined that alpha-[15N]- atoms from 10 amino acids experience minimal metabolic scrambling (C, F, H, K, M, N, R, T, W, Y). Two more interconvert to each other (G, S). Six others experience significant scrambling (A, D, E, I, L, V). We also demonstrate that tuning culture conditions suppressed V and I scrambling. These results define expectations for 15N-labeling in HEK293 cells.

3.
Cureus ; 15(9): e46035, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37900523

RESUMO

Backgroundː Intrahepatic cholestasis of pregnancy (ICP), a hepatic condition that causes severe itching in late pregnancy, is linked to nonalcoholic fatty liver disease (NAFLD) due to disrupted bile acid balance. It poses maternal risks such as preterm labor and gestational diabetes and fetal risks such as preterm birth and respiratory distress. The study examined NAFLD's impact on ICP in pregnant women, highlighting management and research implications. Methodsː This retrospective study examined pregnant women (≥18 years) with ICP, assessing fatty liver with follow-up ultrasounds. Participants were divided into ICP only and ICP with fatty liver (FL) groups, excluding heavy alcohol users and incomplete data. Maternal age, medical history, and comorbidities were evaluated alongside abdominal ultrasounds to identify FL. Resultsː In this study of 43 pregnant women, the mean maternal age was 27 years. Patients with ICP and FL had significantly higher bile acid levels than those with ICP alone. However, no significant differences were found between the two groups regarding the history of gestational diabetes mellitus (GDM), dyslipidemia, polycystic ovarian syndrome (PCOS), parity, and hypothyroidism. Among women with ICP and FL, 51.85% underwent lower segment cesarean section (LSCS), while 43.75% with ICP without FL underwent LSCS. Conclusionsː ICP with FL did not show significant adverse effects on maternal and neonatal outcomes, including mode of delivery, gestational age, maternal complications, neonatal intensive care unit (NICU) admissions, and low birth weight (LBW) with asphyxia. However, additional research is required to fully comprehend the relationship between ICP, NAFLD, and their impact on pregnancy outcomes.

4.
Adv Mater ; 35(42): e2305383, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37578079

RESUMO

The heterogeneous nature, local presence, and dynamic evolution of defects typically govern the ionic and electronic properties of a wide variety of functional materials. While the last 50 years have seen considerable efforts into development of new methods to identify the nature of defects in complex materials, such as the perovskite oxides, very little is known about defect dynamics and their influence on the functionality of a material. Here, the discovery of the intermittent behavior of point defects (oxygen vacancies) in oxide heterostructures employing X-ray photon correlation spectroscopy is reported. Local fluctuations between two ordered phases in strained SrCoOx with different degrees of stability of the oxygen vacancies are observed. Ab-initio-informed phase-field modeling reveals that fluctuations between the competing ordered phases are modulated by the oxygen ion/vacancy interaction energy and epitaxial strain. The results demonstrate how defect dynamics, evidenced by measurement and modeling of their temporal fluctuations, give rise to stochastic properties that now can be fully characterized using coherent X-rays, coupled for the first time to multiscale modeling in functional complex oxide heterostructures. The study and its findings open new avenues for engineering the dynamical response of functional materials used in neuromorphic and electrochemical applications.

5.
J Org Chem ; 88(15): 10916-10924, 2023 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-37450843

RESUMO

A Rh(III)-catalyzed [4 + 1] cyclization of 2-arylbenzimidazoles with alkynoates through C-H activation/ortho-alkenylation/intramolecular annulation cascade to obtain benzimidazole-fused isoindoles is reported. The reaction of the Rh catalyst and internal alkyne ester provides benzo[4,5]imidazo[2,1-a]isoindole acetate exclusively. Conversely, internal alkyne amide participates in the annulation process in the presence of a Ru catalyst to provide benzo[4,5]imidazo[2,1-a]isoindole acetamide. The alkyne acts as a C1 synthon and undergoes [4 + 1] cyclization rather than traditional [4 + 2] annulation.

6.
J Am Soc Mass Spectrom ; 34(7): 1225-1229, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37267530

RESUMO

Laser capture microdissection (LCM) has become an indispensable tool for mass spectrometry-based proteomic analysis of specific regions obtained from formalin-fixed paraffin-embedded (FFPE) tissue samples in both clinical and research settings. Low protein yields from LCM samples along with laborious sample processing steps present challenges for proteomic analysis without sacrificing protein and peptide recovery. Automation of sample preparation workflows is still under development, especially for samples such as laser-capture microdissected tissues. Here, we present a simplified and rapid workflow using adaptive focused acoustics (AFA) technology for sample processing for high-throughput FFPE-based proteomics. We evaluated three different workflows: standard extraction method followed by overnight trypsin digestion, AFA-assisted extraction and overnight trypsin digestion, and AFA-assisted extraction simultaneously performed with trypsin digestion. The use of AFA-based ultrasonication enables automated sample processing for high-throughput proteomic analysis of LCM-FFPE tissues in 96-well and 384-well formats. Further, accelerated trypsin digestion combined with AFA dramatically reduced the overall processing times. LC-MS/MS analysis revealed a slightly higher number of protein and peptide identifications in AFA accelerated workflows compared to standard and AFA overnight workflows. Further, we did not observe any difference in the proportion of peptides identified with missed cleavages or deamidated peptides across the three different workflows. Overall, our results demonstrate that the workflow described in this study enables rapid and high-throughput sample processing with greatly reduced sample handling, which is amenable to automation.


Assuntos
Ensaios de Triagem em Larga Escala , Proteômica , Humanos , Fluxo de Trabalho , Proteômica/instrumentação , Proteômica/métodos , Ensaios de Triagem em Larga Escala/instrumentação , Ensaios de Triagem em Larga Escala/métodos , Peptídeos/química
7.
Immunology ; 170(2): 202-213, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37218360

RESUMO

Novel approaches are required to improve the efficacy of immunotherapies and increase the proportion of patients who experience a benefit. Antibody-dependent cell-mediated cytotoxicity (ADCC) contributes to the efficacy of many monoclonal antibodies therapies. Natural killer (NK) cells mediate ADCC, though responses are highly variable and depend on prior treatment as well as other factors. Thus, strategies to increase NK cell activity are expected to improve multiple therapies. Both cytokine treatment and NK cell receptor engineering are being explored to increase ADCC. Post-translational modifications, including glycosylation, are widely recognized as mediators of cellular processes but minimally explored as an alternative strategy to increase ADCC. We evaluated the impact of treatment with kifunensine, an inhibitor of asparagine-linked (N-)glycan processing, on ADCC using primary and cultured human NK cells. We also probed affinity using binding assays and CD16a structure with nuclear magnetic resonance spectroscopy. Treating primary human NK cells and cultured YTS-CD16a cells with kifunensine doubled ADCC in a CD16a-dependent manner. Kifunensine treatment also increased the antibody-binding affinity of CD16a on the NK cell surface. Structural interrogation identified a single CD16a region, proximal to the N162 glycan and the antibody-binding interface, perturbed by the N-glycan composition. The observed increase in NK cell activity following kifunensine treatment synergized with afucosylated antibodies, further increasing ADCC by an additional 33%. These results demonstrate native N-glycan processing is an important factor that limits NK cell ADCC. Furthermore, optimal antibody and CD16a glycoforms are defined that provide the greatest ADCC activity.


Assuntos
Anticorpos Monoclonais , Receptores de IgG , Humanos , Receptores de IgG/metabolismo , Glicosilação , Anticorpos Monoclonais/metabolismo , Células Matadoras Naturais , Polissacarídeos/metabolismo , Citotoxicidade Celular Dependente de Anticorpos
8.
Blood Cancer J ; 13(1): 63, 2023 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-37105956

RESUMO

Multiple myeloma (MM) bone disease is a significant cause of morbidity but there is a paucity of data on the impact of malignant plasma cells on adjacent trabecular bone within the BM. Here, we characterize the proteome of trabecular bone tissue from BM biopsies of 56 patients with monoclonal gammopathy of undetermined significance (MGUS), smoldering (SMM), newly diagnosed (NDMM), relapsed MM (RMM), and normal controls. Proteins involved in extracellular matrix (ECM) formation and immunity pathways were decreased in SMM and active MM. Among the proteins most decreased were immunoglobulins, type IV collagen, and TIMP3, suggesting increased immunoparesis and decreased ECM remodelling within trabecular bone. Proteins most increased in SMM/MM were APP (enhances osteoclast activity), ENPP1 (enhances bone mineralization), and MZB1 (required for normal plasmablast differentiation). Pathway analyses showed that proteins involved in gamma -carboxylation, a pathway implicated in osteocalcin function, osteoblast differentiation, and normal hematopoiesis, were also overexpressed in SMM/MM. This study is the first comprehensive proteomic atlas of the BM bone proteome in dysproteinemias. We identify new key proteins and pathways for MM bone disease and potentially impaired hematopoiesis, and show for the first time that gamma -carboxylation pathways are increased in the bone tissue of SMM/MM.


Assuntos
Doenças Ósseas , Gamopatia Monoclonal de Significância Indeterminada , Mieloma Múltiplo , Humanos , Medula Óssea/patologia , Mieloma Múltiplo/patologia , Proteoma/metabolismo , Proteômica , Gamopatia Monoclonal de Significância Indeterminada/diagnóstico , Osso e Ossos/metabolismo , Doenças Ósseas/metabolismo , Progressão da Doença
9.
J Org Chem ; 88(1): 701-710, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36538787

RESUMO

Benzothiazine 1,1-dioxide (BTDO) is a privileged chemical motif, and its metal-free domino access is in high demand. Current BTDO production methods require costly metal catalysts or harsh reaction conditions. A facile domino approach to BTDO via a water-gas shift reaction (WGSR) employing sodium 2-nitrobenzenesulfinates and α-bromo ketones is presented. This strategy is cost-effective and environmentally beneficial. The optimized reaction conditions demonstrated remarkable chemical tolerance to a wide range of electrically and sterically varied substituents on both coupling partners.

10.
Lancet Glob Health ; 10(10): e1494-e1504, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36113533

RESUMO

BACKGROUND: In Nepal, Streptococcus pneumoniae (pneumococcus) is a common cause of bacterial pneumonia in children, and is a major health concern. There are few data on the effect of vaccination on the disease or colonisation with pneumococci in the nasopharynx of children in this setting. The 10-valent pneumococcal conjugate vaccine (PCV10) was introduced into the routine infant immunisation schedule in Nepal in 2015. We aimed to investigate the effect of the introduction of PCV10 on pneumococcal carriage and disease in children in Nepal. METHODS: We did an observational cohort study in children in Nepal. The hospital surveillance study took place in Patan Hospital, Kathmandu, and community studies in healthy children took place in Kathmandu and Okhaldhunga district. For the surveillance study, all children admitted to Patan Hospital between March 20, 2014, and Dec 31, 2019, aged between 2 months and 14 years with clinician-suspected pneumonia, were eligible for enrolment. For the community study, healthy children aged 0-8 weeks, 6-23 months, and 24-59 months were recruited from Kathmandu, and healthy children aged 6-23 months were recruited from Okhaldhunga. We assessed the programmatic effect of PCV10 introduction using surveillance for nasopharyngeal colonisation, pneumonia, and invasive bacterial disease from 1·5 years before vaccine introduction and 4·5 years after vaccine introduction. For the surveillance study, nasopharyngeal swabs, blood cultures, and chest radiographs were obtained from children admitted to Patan Hospital with suspected pneumonia or invasive bacterial disease. For the community study, nasopharyngeal swabs were obtained from healthy children in the urban and rural settings. Pneumonia outcomes were analysed using log-binomial models and adjusted prevalence ratios (aPR) comparing each calendar year after the introduction of the vaccine into the national programme with the pre-vaccine period (2014-15), adjusted for calendar month, age, and sex. FINDINGS: Between March 20, 2014, and Dec 31, 2019, we enrolled 2051 children with suspected pneumonia, and 11 354 healthy children (8483 children aged 6-23 months, 761 aged 24-59 months, and 2110 aged 0-8 weeks) to assess nasopharyngeal colonisation. Among clinical pneumonia cases younger than 2 years, vaccine serotype carriage declined 82% (aPR 0·18 [95% CI 0·07-0·50]) by 2019. There was no decrease in vaccine serotype carriage in cases among older unvaccinated age groups. Carriage of the additional serotypes in PCV13 was 2·2 times higher by 2019 (aPR 2·17 [95% CI 1·16-4·05]), due to increases in serotypes 19A and 3. Vaccine serotype carriage in healthy children declined by 75% in those aged 6-23 months (aPR 0·25 [95% CI 0·19-0·33]) but not in those aged 24-59 months (aPR 0·59 [0·29-1·19]). A decrease in overall vaccine serotype carriage of 61% by 2019 (aPR 0·39 [95% CI 0·18-0·85]) was also observed in children younger than 8 weeks who were not yet immunised. Carriage of the additional PCV13 serotypes in children aged 6-23 months increased after PCV10 introduction for serotype 3 and 19A, but not for serotype 6A. The proportion of clinical pneumonia cases with endpoint consolidation on chest radiographs declined from 41% in the pre-vaccine period to 25% by 2018, but rose again in 2019 to 36%. INTERPRETATION: The introduction of the PCV10 vaccine into the routine immunisation programme in Nepal has reduced vaccine serotype carriage in both healthy children and children younger than 2 years with pneumonia. Increases in serotypes 19A and 3 highlight the importance of continued surveillance to monitor the effect of vaccine programmes. This analysis demonstrates a robust approach to assessing vaccine effect in situations in which pneumococcal disease endpoint effectiveness studies are not possible. FUNDING: Gavi, the Vaccine Alliance and the World Health Organization.


Assuntos
Infecções Pneumocócicas , Pneumonia , Portador Sadio/epidemiologia , Criança , Estudos de Coortes , Humanos , Lactente , Nepal/epidemiologia , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/microbiologia , Infecções Pneumocócicas/prevenção & controle , Vacinas Pneumocócicas , Streptococcus pneumoniae
11.
Int J Mol Sci ; 23(14)2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35887150

RESUMO

Most living organisms have in their genome a sizable proportion of DNA sequences capable of mobilization; these sequences are commonly referred to as transposons, transposable elements (TEs), or jumping genes. Although long thought to have no biological significance, advances in DNA sequencing and analytical technologies have enabled precise characterization of TEs and confirmed their ubiquitous presence across all forms of life. These findings have ignited intense debates over their biological significance. The available evidence now supports the notion that TEs exert major influence over many biological aspects of organismal life. Transposable elements contribute significantly to the evolution of the genome by giving rise to genetic variations in both active and passive modes. Due to their intrinsic nature of mobility within the genome, TEs primarily cause gene disruption and large-scale genomic alterations including inversions, deletions, and duplications. Besides genomic instability, growing evidence also points to many physiologically important functions of TEs, such as gene regulation through cis-acting control elements and modulation of the transcriptome through epigenetic control. In this review, we discuss the latest evidence demonstrating the impact of TEs on genome stability and the underling mechanisms, including those developed to mitigate the deleterious impact of TEs on genomic stability and human health. We have also highlighted the potential therapeutic application of TEs.


Assuntos
Elementos de DNA Transponíveis , Instabilidade Genômica , Elementos de DNA Transponíveis/genética , Evolução Molecular , Genômica , Humanos , Sequências Reguladoras de Ácido Nucleico , Transcriptoma
12.
Bioelectrochemistry ; 146: 108166, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35643022

RESUMO

Venous thromboembolism is one of the major disorders, which is significantly increased the mortality and morbidity rate. Warfarin sodium (WFS) is the most extensively prescribed drug for the prevention of thromboembolic diseases however, it has a narrow therapeutic index. Recently, many methods for detecting and monitoring the level of WFS have been proposed. However, the electrochemical method has gained more interest than the other traditional method due to its ease of operation. This article describes the hydrothermal synthesis of nickel-doped cerium oxide (CeO2@Ni) nanospheres for the selective electrochemical determination of WFS. Various spectroscopic techniques have been used to analyze the chemical composition, and surface morphology of CeO2@Ni nanospheres. Further, the prepared CeO2@Ni nanospheres modified electrode demonstrated excellent electrocatalytic behavior for WFS detection, with an ultralow detection limit of 6.3 × 10-9 M, a linear range of 1.0 × 10-8 M to 1.51 × 10-4 M and 1.51 × 10-4 M to 9.51 × 10-4 M, and a higher sensitivity of 2.9986 µA µM-1 cm2. Therefore, we believe that the CeO2@Ni nanosphere electrocatalyst can serve as a potential electrode catalyst for the sensing of WFS in real-time applications.


Assuntos
Cério , Nanosferas , Cério/química , Técnicas Eletroquímicas/métodos , Eletrodos , Níquel/química , Varfarina
13.
J Indian Soc Periodontol ; 26(3): 224-229, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35602532

RESUMO

Background: Human dental plaque is a complex microbial community containing millions of species. Gingivitis is a dysregulated immune-inflammatory response induced by dysbiotic plaque biofilm that interrupts symbiosis. The emergence of next-generation sequencing with 16S rRNA gene has greatly contributed in understanding the complexity of microbiota. However, studies focusing on microbiome in gingivitis are limited. The whole bacterial community is important in causing periodontal disease than a small number of periodontal pathogens. In this study, we attempted to profile the subgingival microbiome from individuals with healthy gingiva and in patients with gingivitis using next-generation sequencing technology. Materials and Methods: Subgingival plaque samples from 15 healthy periodontium (Group I) and 15 gingivitis (Group II) were collected and 16s rRNA sequencing was done in Illumina Solexa Sequencer. Data analysis using 16s metagenomics tool from BaseSpace onsite operational taxonomic units was assigned to each sequence using HOMD database. Individual variation in the microbiome of the subgingival samples between the two groups was also evaluated. Results: The comparison of top 20 species between Group I and Group II revealed no significant species group between them. Synergistetes was absent in Group I samples but found in Group II. At the genus level, HACEK group species were found in both the groups, while Dialister and Aneroglobus were found abundantly in the Group II. Conclusion: The presence of unique genera and species seen in Group II samples could point toward a dysbiotic shift that could be taking place in the subgingival environment leading to gingivitis.

14.
Cureus ; 14(2): e22701, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-35386157

RESUMO

This case series describes the use of ultrasound (US)-guided dorsal sacral foraminal block (DSFB) for providing postoperative analgesia in six patients who underwent foot and ankle surgeries under spinal anesthesia. Postoperatively, all of them received a US-guided DSFB at the level of the brim of the second sacral foramina (SF2). Needle placements were confirmed with fluoroscopic (FL) images and injected radiocontrast defined the diffusion with a postoperative CT scan. The images obtained depicted ipsilateral spread in the sacral epidural space, sacral nerve roots, and plexus. The US-guided DSFB could be effectively used as an alternative method for postoperative pain relief after foot and ankle surgery.

15.
Sci Total Environ ; 825: 153973, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35183624

RESUMO

The management of post-consumer discarded plastic wastes (PCPW) creates new challenges in developing countries due to the lack of amenities, technological interventions, and associated negative environmental externalities. The fate of untreated recyclable and non-recyclable plastic wastes lies in open dumping along with other solid waste, and improper management leads to environmental externalities such as pollution, global climate change, and health issues. Additionally, open dumping upsurges the emerging microplastics and nano plastics (MNPs) contaminants. The externalities depend on the waste generating sources (household, industries, commercial), waste composition, and its characteristics. However, urban mining can minimize environmental externalities where waste plastics can convert into potential anthropogenic resources and also helps in achieving the target of sustainable development goals (SDGs 11 & 12). Moreover, various treatment technologies that help in the sustainable utilization of plastic wastes are extensively reviewed in this study and evaluate the costs benefits arising during various stages of treating plastic waste through recycling (R), incineration (I), and landfilling (L). The recycling of plastic waste has demonstrated the lowest impact on global warming potential (GWP) and total energy use (TEU), followed by landfilling and incineration (R < L < I). Nevertheless, when energy is recovered from inert (non-recyclable) plastic waste in the form of fuel or by its utilization in construction purposes, the environmental impacts are more negligible (Incineration < Landfilling). Therefore, this study determines the significance of circular economy with legislative approach and standards on plastic waste management, which help in reducing environmental externalities besides yielding a secondary resource as energy and materials through urban mining. A sustainable plastic waste management (SPWM) model is proposed for developing countries to convert plastic waste into resources and use it as a sustainable tool in urban mining.


Assuntos
Eliminação de Resíduos , Gerenciamento de Resíduos , Incineração , Plásticos , Reciclagem , Resíduos Sólidos/análise
16.
Pediatr Infect Dis J ; 41(3): 192-198, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-34955523

RESUMO

BACKGROUND: Invasive bacterial disease (IBD; including pneumonia, meningitis, sepsis) is a major cause of morbidity and mortality in children in low-income countries. METHODS: We analyzed data from a surveillance study of suspected community-acquired IBD in children <15 years of age in Kathmandu, Nepal, from 2005 to 2013 before introduction of pneumococcal conjugate vaccines (PCV). We detailed the serotype-specific distribution of invasive pneumococcal disease (IPD) and incorporated antigen and PCR testing of cerebrospinal fluid (CSF) from children with meningitis. RESULTS: Enhanced surveillance of IBD was undertaken during 2005-2006 and 2010-2013. During enhanced surveillance, a total of 7956 children were recruited of whom 7754 had blood or CSF culture results available for analysis, and 342 (4%) had a pathogen isolated. From 2007 to 2009, all 376 positive culture results were available, with 259 pathogens isolated (and 117 contaminants). Salmonella enterica serovar Typhi was the most prevalent pathogen isolated (167 cases, 28% of pathogens), followed by Streptococcus pneumoniae (98 cases, 16% pathogens). Approximately, 73% and 78% of pneumococcal serotypes were contained in 10-valent and 13-valent PCV, respectively. Most cases of invasive pneumococcal disease (IPD) were among children ≥5 years of age from 2008 onward. Antigen and PCR testing of CSF for pneumococci, Haemophilus influenzae type b and meningococci increased the number of these pathogens identified from 33 (culture) to 68 (culture/antigen/PCR testing). CONCLUSIONS: S. enterica serovar Typhi and S. pneumoniae accounted for 44% of pathogens isolated. Most pneumococcal isolates were of serotypes contained in PCVs. Antigen and PCR testing of CSF improves sensitivity for IBD pathogens.


Assuntos
Infecções Bacterianas/epidemiologia , Streptococcus pneumoniae , Antígenos de Bactérias , Infecções Bacterianas/sangue , Infecções Bacterianas/líquido cefalorraquidiano , Infecções Bacterianas/microbiologia , Pré-Escolar , Feminino , Haemophilus influenzae tipo b , Humanos , Lactente , Masculino , Meningite Pneumocócica/epidemiologia , Testes de Sensibilidade Microbiana , Neisseria meningitidis , Nepal/epidemiologia , Infecções Pneumocócicas/sangue , Infecções Pneumocócicas/líquido cefalorraquidiano , Infecções Pneumocócicas/epidemiologia , Vacinas Pneumocócicas , Reação em Cadeia da Polimerase , Sorogrupo , Sorotipagem , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/isolamento & purificação , Vacinas Conjugadas
17.
Pediatr Infect Dis J ; 40(10): 937-943, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34292271

RESUMO

BACKGROUND: The pneumococcal conjugate vaccine has had a substantial impact on invasive pneumococcal disease. Previously, we compared immunity following vaccination with the 10-valent pneumococcal conjugate vaccine (PCV10) administered at 2 slightly different schedules: at 6 and 10 weeks of age, and at 6 and 14 weeks of age, both followed by a 9-month booster. In this study, we followed up those participants to evaluate the medium-term persistence of serotype-specific pneumococcal immunity at 2-3 years of age. METHOD: Children from the previous studies were contacted and after taking informed consent from their parents, blood samples and nasopharyngeal swabs were collected. Serotype-specific IgG antibody concentrations were determined by enzyme-linked immunosorbent assay, for the 10 vaccine serotypes, at a WHO pneumococcal serology reference laboratory. FINDINGS: Two hundred twenty of the 287 children who completed the primary study returned at 2-3 years of age to provide a blood sample and nasopharyngeal swab. The nasopharyngeal carriage rate of PCV10 serotypes in the 6 + 14 group was higher than the 6 + 10 group (13.4% vs. 1.9%). Nevertheless, the proportion of toddlers with serum pneumococcal serotype-specific IgG greater than or equal to 0.35 µg/mL was comparable for all PCV10 serotypes between the 6 + 10 week and 6 + 14 week groups. Similarly, the geometric mean concentrations of serum pneumococcal serotype-specific IgG levels were similar in the 2 groups for all serotypes, except for serotype 19F which was 32% lower in the 6 + 10 group than the 6 + 14 group. CONCLUSION: Immunization with PCV10 at 6 + 10 weeks or 6 + 14 weeks, with a booster at 9 months in each case, results in similar persistence of serotype-specific antibody at 2-3 years of age. Thus, protection from pneumococcal disease is expected to be similar when either schedule is used.


Assuntos
Anticorpos Antibacterianos/sangue , Esquemas de Imunização , Vacinas Pneumocócicas/administração & dosagem , Vacinas Pneumocócicas/imunologia , Sorogrupo , Vacinação/métodos , Portador Sadio/microbiologia , Pré-Escolar , Estudos Transversais , Seguimentos , Humanos , Imunoglobulina G/sangue , Nasofaringe/microbiologia , Nepal , Infecções Pneumocócicas/imunologia , Infecções Pneumocócicas/prevenção & controle , Streptococcus pneumoniae/classificação , Streptococcus pneumoniae/imunologia , Vacinas Conjugadas/imunologia
18.
Biomed Pharmacother ; 141: 111794, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34153851

RESUMO

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) is the causative agent of Corona Virus Disease 2019 (COVID-19). Lower production of type I and III interferons and higher levels of inflammatory mediators upon SARS-CoV2 infection contribute to COVID-19 pathogenesis. Optimal interferon production and controlled inflammation are essential to limit COVID-19 pathogenesis. However, the aggravated inflammatory response observed in COVID-19 patients causes severe damage to the host and frequently advances to acute respiratory distress syndrome (ARDS). Toll-like receptor 7 and 8 (TLR7/8) signaling pathways play a central role in regulating induction of interferons (IFNs) and inflammatory mediators in dendritic cells. Controlled inflammation is possible through regulation of TLR mediated response without influencing interferon production to reduce COVID-19 pathogenesis. This review focuses on inflammatory mediators that contribute to pathogenic effects and the role of TLR pathways in the induction of interferon and inflammatory mediators and their contribution to COVID-19 pathogenesis. We conclude that potential TLR7/8 agonists inducing antiviral interferon response and controlling inflammation are important therapeutic options to effectively eliminate SARS-CoV2 induced pathogenesis. Ongoing and future studies may provide additional evidence on their safety and efficacy to treat COVID-19 pathogenesis.


Assuntos
COVID-19/metabolismo , Mediadores da Inflamação/metabolismo , Interferons/metabolismo , Transdução de Sinais/fisiologia , Receptor 7 Toll-Like/fisiologia , Receptor 8 Toll-Like/fisiologia , Anti-Inflamatórios/administração & dosagem , COVID-19/imunologia , COVID-19/terapia , Humanos , Mediadores da Inflamação/imunologia , Interferons/imunologia , Receptor 7 Toll-Like/agonistas , Receptor 8 Toll-Like/agonistas
19.
J Phys Chem Lett ; 12(9): 2320-2326, 2021 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-33651627

RESUMO

2D materials have attracted tremendous interest as functional materials because of their diverse and tunable properties, especially at their edges. A material's work function is a critical parameter in many electronic devices; however, a fundamental understanding and a path toward large alterations of the work function in 2D materials still remain elusive. Here, we report the first evidence for anisotropy of the work function in 2D MoS2 from first-principles calculations. We also demonstrate large work-function tunability (in the range of 3.45-6.29 eV) choosing the 2H phase of MoS2 as a model system by sampling various edge configurations. We furthermore reveal the origin of this work function anisotropy and tunability by extending the existing work function relation to the local dipole moment at surfaces of 3D materials to those at edges in 2D materials. We then use machine-learning approaches to correlate work function with edge structures. These results pave the way for intrinsic edge engineering for electronic and catalytic applications.

20.
Nat Commun ; 12(1): 88, 2021 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-33398014

RESUMO

Materials databases generated by high-throughput computational screening, typically using density functional theory (DFT), have become valuable resources for discovering new heterogeneous catalysts, though the computational cost associated with generating them presents a crucial roadblock. Hence there is a significant demand for developing descriptors or features, in lieu of DFT, to accurately predict catalytic properties, such as adsorption energies. Here, we demonstrate an approach to predict energies using a convolutional neural network-based machine learning model to automatically obtain key features from the electronic density of states (DOS). The model, DOSnet, is evaluated for a diverse set of adsorbates and surfaces, yielding a mean absolute error on the order of 0.1 eV. In addition, DOSnet can provide physically meaningful predictions and insights by predicting responses to external perturbations to the electronic structure without additional DFT calculations, paving the way for the accelerated discovery of materials and catalysts by exploration of the electronic space.

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