Seroprevalence of IgM and IgG Antibodies against SARS-CoV-2 in Asymptomatic People in Wuhan: Data from a General Hospital Near South China Seafood Wholesale Market during March to April in 2020 / 生物医学与环境科学（英文）

The aim of this study was to estimate the seroprevalence of immunoglobulin M (IgM) and G (IgG) antibodies against SARS-CoV-2 in asymptomatic people in Wuhan. This was a cross-sectional study, which enrolled 18,712 asymptomatic participants from 154 work units in Wuhan. Pearson Chi-square test,

Experimental models of autoimmune inflammatory ocular diseases / Modelos experimentais para o estudo de doenças inflamatórias oculares autoimunes

Ocular inflammation is one of the leading causes of blindness and loss of vision. Human uveitis is a complex and heterogeneous group of diseases characterized by inflammation of intraocular tissues. The eye may be the only organ involved, or uveitis may be part of a systemic disease. A significant number of cases are of unknown etiology and are labeled idiopathic. Animal models have been developed to the study of the physiopathogenesis of autoimmune uveitis due to the difficulty in obtaining human eye inflamed tissues for experiments. Most of those models are induced by injection of specific photoreceptors proteins (e.g., S-antigen, interphotoreceptor retinoid-binding protein, rhodopsin, recoverin, phosducin). Non-retinal antigens, including melanin-associated proteins and myelin basic protein, are also good inducers of uveitis in animals. Understanding the basic mechanisms and pathogenesis of autoimmune ocular diseases are essential for the development of new treatment approaches and therapeutic agents. The present review describes the main experimental models of autoimmune ocular inflammatory diseases.

A inflamação ocular é uma das principais causas de perda visual e cegueira. As uveítes constituem um grupo complexo e heterogêneo de doenças caracterizadas por inflamação dos tecidos intraoculares. O olho pode ser o único órgão envolvido ou a uveíte pode ser parte de uma doença sistêmica. A etiologia é desconhecida em um número significativo de casos, que são considerados idiopáticos. Modelos animais têm sido desenvolvidos para estudar a fisiopatogênese da uveíte autoimune devido às dificuldades na obtenção de tecidos de olhos humanos inflamados para experimentos. Na maioria desses modelos, que simulam as uveítes autoimunes em humanos, a uveíte é induzida com proteínas específicas de fotorreceptores (antígeno-S, proteína ligadora de retinoide do interfotoreceptor, rodopsina, recoverina e fosducina). Antígenos não retinianos, como proteínas associadas à melanina e proteína básica de mielina, são também bons indutores de uveíte em animais. Entender os mecanismos básicos e a patogênese dessas doenças oculares é essencial para o desenvolvimento de novas formas de tratamento das uveítes autoimunes e de novos agentes terapêuticos. Nesta revisão serão abordados os principais modelos experimentais utilizados para o estudo de doenças inflamatórias oculares autoimunes.

Comparison of the performance of polymerase chain reaction and pp65 antigenemia for the detection of human cytomegalovirus in immunosuppressed patients / Comparação de métodos para detecção de infecção por citomegalovírus em pacientes imunossuprimidos

INTRODUCTION: Human cytomegalovirus (HCMV) is often reactive in latently infected immunosuppressed patients. Accordingly, HCMV remains one of the most common infections following solid organ and hemopoietic stem cell transplantations, resulting in significant morbidity, graft loss and occasional mortality. The early diagnosis of HCMV disease is important in immunosuppressed patients, since in these individuals, preemptive treatment is useful. The objective of this study was to compare the performance of the in-house qualitative polymerase chain reaction (PCR) and pp65 antigenemia to HCMV infection in immunosuppressed patients in the Hospital de Clínicas of Porto Alegre (HCPA). METHODS: A total of 216 blood samples collected between August 2006 and January 2007 were investigated. RESULTS: Among the samples analyzed, 81 (37.5 percent) were HCMV-positive by PCR, while 48 (22.2 percent) were positive for antigenemia. Considering antigenemia as the gold standard, sensitivity, specificity, positive predictive values and negative predictive values for PCR were 87.5 percent, 76.8 percent, 51.8 percent and 95.5 percent respectively. CONCLUSIONS: These results demonstrated that qualitative PCR has high sensitivity and negative predictive value (NPV). Consequently PCR is especially indicated for the initial diagnosis of HCMV infection. In the case of preemptive treatment strategy, identification of patients at high-risk for HCMV disease is fundamental and PCR can be useful tool.

INTRODUÇÃO: O citomegalovírus humano (HCMV), causador de infecção latente, reativa com frequência em pacientes imunossuprimidos. Portanto, o HCMV permanece uma das infecções mais comuns após transplantes de órgãos sólidos e de células hematopoiéticas resultando em significativa morbidade, perda do enxerto e ocasional mortalidade. Assim, o diagnóstico precoce para uma terapia preventiva é de grande importância. Este estudo visa comparar o desempenho dos métodos PCR qualitativo in-house e antigenemia pp65 para o diagnóstico de infecção por CMV em pacientes imunossuprimidos do Hospital de Clínicas de Porto Alegre. MÉTODOS: O estudo foi realizado em 216 amostras de sangue total (EDTA) coletadas de 85 pacientes, entre agosto de 2006 e janeiro de 2007. RESULTADOS: Dentre as 216 amostras analisadas, 81 (37,5 por cento) amostras apresentaram resultados positivos na PCR, enquanto 48 (22,2 por cento) apresentaram resultados positivos na antigenemia. A sensibilidade, especificidade, valor preditivo positivo e valor preditivo negativo para a PCR, considerando antigenemia como padrão foram 87,5 por cento, 76,8 por cento, 51,8 por cento e 95,5 por cento, respectivamente. CONCLUSÕES: Estes resultados demonstraram que a PCR tem alta sensibilidade e valor preditivo negativo. Consequentemente PCR é especialmente indicada para o diagnóstico inicial de infecção por HCMV. No caso da estratégia de terapia preventiva, a identificação de pacientes com alto risco para a doença por HCMV é fundamental e a PCR pode ser uma ferramenta útil.

combined pretransplantation seropositivity of kidney transplant recipients for cytomegalovirus antigens [pp150 and pp28] a predictor for protection against infection?

This study was aimed at detecting antibodies to the antigens which may contribute to protection against cytomegalovirus [CMV] infection after organ transplantation. A total of 203 kidney transplant patients were enrolled in the study. Based on CMV antigenemia assay, 23 patients were antigen-positive and of the remaining 180 antigen-negative patients, 46 were selected as controls matched for age, gender and source of kidney. The 69 kidney recipients [KR] had CMV antibody due to previous infection and were followed up for a period of 6 months after transplantation for the development of active CMV infections by the antigenemia assay. Antibody responses to five CMV-related peptide antigens [pp65, gB, pp150, pp28 and pp38] were investigated by enzyme immunoassay and their presence was correlated with the results of the CMV antigenemia assay. Of the five CMV-related peptide antigens, only gB antigen showed response to the antibody in 10/23 [43.5%] antigen-positive patients and 9/46 antigen-negative patients and the difference was statistically significant [p = 0.048]. On the other hand, there was no significant difference in antibody responses between the antigen-positive and antigen-negative KR to the other four CMV peptide antigens [p > 0.05]. However, among the antigen-positive KR there was only 1 patient who had antibodies to both pp150 and pp28 antigen, while among the antigen-negative KR, 22 of 46 [47.8%] had the antibodies [p < 0.001]. The findings suggest that the combined presence of antibodies against the pp150 and pp28 antigens may indicate a lower risk of CMV reactivation after kidney transplantation

Calyculin A modulates activation of the NADPH-oxidase in Me2SO-differentiated HL-60 cells

Human promyelocytic leukemia cells (HL-60) have been used as a model system in which to study the effects of protein phosphatase inhibitors on NADPH-oxidase activation. Since O2- is generated by NADPH-oxidase, we examined the effect of calyculin A pretreatment on oxidase activation in response to various agonists. When Me2SO-differentiated HL-60 cells were treated with calyculin A prior to the addition of phorbol 12-myristate 13-acetate (PMA), O2- production was inhibited; however, calyculin A enhanced O2- production by N-formyl-methionyl-leucyl-phenylalanine (FMLP). The decreased O2- production seen with calyculin A pretreatment followed by PMA may be due to diminished translocation of the p47-phox and p67-phox, cytosolic components of the oxidase, and inhibition of arachidonic acid release. Interestingly calyculin A pretreatment followed by either agonist significantly enhanced mitogen-activated-protein kinase (MAPK) activity. The differential effects of pretreatment with calyculin A on subsequent oxidase stimulation elicited by FMLP or PMA provide further evidence for substantial heterogeneity in the activation of the respiratory burst.

A conserved epitope on nuclear pore phosphoproteins reflects cell division status.

The nuclear pore complexes mediate the selective nuclear import of proteins in a signal- and energy-dependent process. We have earlier reported the characterization of a monoclonal antibody, Mab E2, that recognizes a novel class of nuclear pore phosphoproteins involved in signal-binding and protein transport. In the present study, we have analyzed the pattern of immunoreactivity of Mab E2 in cultured rat fibroblasts and have observed significant differences in the expression of epitopes in proliferating and quiescent cells. Furthermore, the common epitope recognized by Mab E2 is conserved across species, consistent with its essential role in nuclear protein import.