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1.
Sci Immunol ; 7(78): eade9888, 2022 12 23.
Artigo em Inglês | MEDLINE | ID: mdl-36378074

RESUMO

The SARS-CoV-2 Omicron variant and its sublineages show pronounced viral escape from neutralizing antibodies elicited by vaccination or prior SARS-CoV-2 variant infection owing to over 30-amino acid alterations within the spike (S) glycoprotein. Breakthrough infection of vaccinated individuals with Omicron sublineages BA.1 and BA.2 is associated with distinct patterns of cross-neutralizing activity against SARS-CoV-2 variants of concern (VOCs). In continuation of our previous work, we characterized the effect of Omicron BA.4/BA.5 S glycoprotein exposure on the neutralizing antibody response upon breakthrough infection in vaccinated individuals and upon variant-adapted booster vaccination in mice. We found that immune sera from triple mRNA-vaccinated individuals with subsequent breakthrough infection during the Omicron BA.4/BA.5 wave showed cross-neutralizing activity against previous Omicron variants BA.1, BA.2, BA.2.12.1, and BA.4/BA.5 itself. Administration of a prototypic BA.4/BA.5-adapted mRNA booster vaccine to mice after SARS-CoV-2 wild-type strain-based primary immunization is associated with broader cross-neutralizing activity than a BA.1-adapted booster. Whereas the Omicron BA.1-adapted mRNA vaccine in a bivalent format (wild-type + BA.1) broadens cross-neutralizing activity relative to the BA.1 monovalent booster, cross-neutralization of BA.2 and descendants is more effective in mice boosted with a bivalent wild-type + BA.4/BA.5 vaccine. In naïve mice, primary immunization with the bivalent wild-type + Omicron BA.4/BA.5 vaccine induces strong cross-neutralizing activity against Omicron VOCs and previous variants. These findings suggest that, when administered as boosters, mono- and bivalent Omicron BA.4/BA.5-adapted vaccines enhance neutralization breadth and that the bivalent version also has the potential to confer protection to individuals with no preexisting immunity against SARS-CoV-2.


Assuntos
COVID-19 , Vacinas , Humanos , Animais , Camundongos , SARS-CoV-2 , COVID-19/prevenção & controle , Anticorpos Neutralizantes , Infecções Irruptivas , RNA Mensageiro
2.
J Med Virol ; 92(11): 2582-2592, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32470142

RESUMO

Rotavirus infections have become one of the most common causes of infectious gastroenteritis in children. Although rotavirus infections have been intensively studied in infants and young children, the study in adults has been limited. As such, this study assessed the prevalence of rotaviruses and performed the molecular characterization of rotaviruses circulating in Thai adults experiencing acute gastroenteritis between January 2018 and December 2018. Group A human rotaviruses were detected in 100 feces samples by rapid immunochromatography. The peak incidence of infection occurred in February and began to decline in the summer months. From January 2018 to December 2018, there were 1344 acute gastroenteritis adult cases in the Hospital for Tropical Diseases, Bangkok, Thailand. Among these, 310 cases were rotavirus-suspected cases. Only 100 samples tested positive for rotavirus via an immunochromatography test. Twentynine out of the 100 rotavirus-positive samples were further characterized by real-time polymerase chain reaction. The G3[P8] strain was identified as the most prevalent (31.0%) followed by G1P[8], G8P[8] and G9P[8], and G2P[8], which accounted for 20.8%, 17.2%, and 13.8%, respectively. Because of the detection of rare rotavirus genotypes, such as G8, the surveillance of rotavirus epidemiology is crucial in monitoring new emergences of rotavirus strains, leading to a better understanding of the effects of strain variation for further vaccine development.


Assuntos
Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia , Rotavirus/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Fezes/virologia , Feminino , Gastroenterite/epidemiologia , Gastroenterite/virologia , Genótipo , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Filogenia , Prevalência , Rotavirus/classificação , Rotavirus/isolamento & purificação , Estações do Ano , Tailândia/epidemiologia , Adulto Jovem
3.
Phys Rev Lett ; 109(25): 252001, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23368451

RESUMO

The analytic structure of the nonperturbative gluon propagator contains information on the absence of gluons from the physical spectrum of the theory. We study this structure from numerical solutions in the complex momentum plane of the gluon and ghost Dyson-Schwinger equations in Landau gauge Yang-Mills theory. The resulting ghost and gluon propagators are analytic apart from a distinct cut structure on the real, timelike momentum axis. The propagator violates the Osterwalder-Schrader positivity condition, confirming the absence of gluons from the asymptotic spectrum of the theory.

6.
Neurology ; 59(6): 893-7, 2002 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-12297573

RESUMO

BACKGROUND: Disorders of imitation are traditionally considered as a symptom of apraxia, but defective imitation of gestures can contrast with intact performance of gestures to verbal command and vice versa. It thus seems worthwhile to explore the neural basis of imitation of gestures independently of other manifestations of apraxia. OBJECTIVE: To assess body part specificity of disturbances of imitation for meaningless gestures of fingers, hand, and foot. METHOD: Imitation of meaningless gestures involving fingers (internal hand configuration), hand (external hand position), or foot was examined in 30 patients with left brain damage (LBD), 20 patients with right brain damage (RBD), and 20 normal control subjects. RESULTS: LBD affected imitation of hand and foot gestures more than imitation of finger gestures, whereas RBD had the strongest effect on finger gestures and affected foot gestures more than hand gestures. CONCLUSION: These results can be accounted for by the assumption that body part coding of gestures depends on left hemisphere function and that additional right hemisphere contributions are afforded when demands on perceptual discrimination rise.


Assuntos
Lateralidade Funcional/fisiologia , Gestos , Hipóxia Encefálica/fisiopatologia , Comportamento Imitativo/fisiologia , Adulto , Idoso , Análise de Variância , Apraxias/fisiopatologia , Feminino , , Mãos , Humanos , Masculino , Pessoa de Meia-Idade , Estatísticas não Paramétricas
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