Reinfección, inmunidad y prevención de la transmisión en la COVID-19 / Reinfection, immunity and prevention of transmission of COVID-19

Introducción: La duración de la inmunidad natural generada por la COVID-19 está por definir, lo que determina la probable reinfección. Objetivo: Destacar la necesidad de mantener las medidas de prevención a propósito de un caso de reinfección en un trabajador sanitario. Presentación de caso: Paciente femenina de 48 años de edad con antecedentes de salud que, en junio, 2020 y marzo, 2021 se le diagnóstica la COVID-19, en ambos casos con el comportamiento de enfermedad sintomática leve. Después de 24 horas de comenzar con cefalea, mareos y tos seca se confirma el diagnóstico de infección por SARS CoV-2 con PCR positivo y umbral de ciclo (CT) en 24.84. Pasados 9 meses y 9 días de la infección original, y dos días posteriores a recibir la vacuna BNT162b2 (Pfizer-BioNTech), comienza con malestar general, tos seca, secreción nasal y dolor de garganta, con PCR positivo y CT de 17.61. Conclusiones: La posibilidad de la reinfección por la COVID-19 orienta la necesidad de fortalecer las acciones de prevención de la transmisión en instituciones de salud en tanto las evidencias científicas nos provean de recursos más eficaces para su control(AU)

Introduction: The duration of natural immunity generated by COVID-19 is yet to be defined, which determines the probable reinfection. Objective: To analyze issues related to natural infection and the need to maintain prevention practices regarding a case of reinfection in a health care worker. Case presentation: Forty-eight-year-old female patient without comorbidities who was diagnosed with COVID-19 in June 2020 and March 2021, in both cases as a mild symptomatic disease. Twenty-four hours after the onset with headache, dizziness, and dry cough, the diagnosis of SARS CoV-2 infection was confirmed by positive PCR and cycle threshold (CT) at 24.84. Nine months and nine days after original infection, and two days after receiving the BNT162b2 vaccine (Pfizer-BioNTech), the patient began with general malaise, dry cough, runny nose, and sore throat, with a positive PCR and CT of 17.61. Conclusions: The possibility of reinfection by COVID-19 points to the need to strengthen transmission prevention practices in healthcare facilities as long as scientific evidence provides us with more effective resources for its control(AU)

Interpretation of the pathogenesis part of Clinical Practice Guideline:Diagnosis and Treatment in Children with Allergic Rhinitis / 中国实用儿科杂志

Allergic rhinitis(AR)in children is non-infectious chronic inflammatory disease in the nasal mucosa which was largely determined by IgE when the body is exposed to allergens. It was believed that Th1/Th2 immune imbalance is the main pathogenesis of AR;however,more and more studies put emphasis on the integrality of individual immune system of the disease. Systematic discussion on the pathogenesis of natural immunity and acquired immunity in allergic rhinitis may provide useful AR treatments in the future.

Role of protein phosphatase in regulating antiviral innate immune response / 第二军医大学学报

Protein phosphatases play critical roles in regulating cell division, cell apoptosis, and cell cycle in eukaryotic cells, participating in numerous signal transduction processes and exerting a large amount of significant biological functions. A variety of protein phosphatases are identified to maintian the phosphorylation level of key proteins with a moderate level in the antiviral innate immune response to virus infectioa In this paper, we reviewed the roles of serine/threonine protein phosphatases, tyrosine protein phosphatases, and lipid phosphatases in regulating antiviral innate immune responses.

Advances in basic immunology and implications for ocular immunology / 中华实验眼科杂志

Immune homeostasis is among the mechanisms of keeping organisms healthy and capable of responding to unfavorable insults either from exogenous or endogenous environments.In recent years,major progress has been made in basic immunology as spotlighted by innate immunity,characterization of novel subclasses of dendritic cells,T or B lymphocytes,and modulation by microRNA (miRNA),long non-coding RNA (LncRNA) and epigenetics.Meanwhile,the eye poses an organ with complex structure and function with specific requirement for immune processes.Pathogenesis or treatment of major ocular disorders involves transplantation immunology,infection immunology,autoimmunity,hypersensitivity,etc.Hence progression in basic immunology lends valuable insights to scientists or ophthalmologists,helping them to understand ocular immunology concerning eye diseases.This review briefs recent updates and future directions in the basic immunology,aiming to provide more reference to the society of ocular immunology.

O papel do receptor toll-like 4 na aterogênese em modelo experimental de aterosclerose / Role of toll-like receptor 4 in atherogenesis in an experimental model of atherosclerosis

Um papel importante foi atribuído ao receptor toll-like 4 (TLR4) no desenvolvimento da placa aterosclerótica. O TLR4 foi primeiramente descrito como um receptor para bactérias gram-negativas; posteriormente foi demonstrado que sua expressão está aumentada em placas ateroscleróticas e que pacientes que possuem um polimorfismo disfuncional do TLR4 são menos suscetíveis ao desenvolvimento dessa doença. Portanto, o objetivo desse estudo foi o de investigar, em um modelo experimental de aterosclerose, a influência da deleção do TLR4 na formação e morfologia da placa aterosclerótica, no perfil lipídico e em marcadores inflamatórios. Camundongos duplo knockout (DKO), deficientes no receptor de LDL e TLR4, foram gerados cruzando-se camundongos deficientes para o receptor de LDL (LDLrKO) com camundongos deficientes para o TLR4 (TLR4KO). Todos os grupos receberam dieta rica em gordura e colesterol por 12 semanas. As concentrações plasmáticas de colesterol e triglicérides foram medidas por ensaio colorimétrico. Cortes seriados da raiz aórtica foram corados com Oil red O e as áreas de lesão quantificadas por analisador de imagens. O colágeno foi medido por coloração de picrossirius. A formação de nitrotirosina e expressão de CD40L, MMP9 e iNOS nas placas foram feitas por imunohistoquímica. As comparações foram feitas por ANOVA com pós teste de Student Newman-Keuls. Os dados foram expressos como média ± EPM. Camundongos DKO desenvolveram placas menores que camundongos LDLrKO (117.6 ±1.4 vs 198.8 ± 3.3 104m2). Camundongos TLR4KO não formaram placa. As placas dos camundongos DKO apresentaram menor núcleo lipídico que as dos LDLrKO (76.2± 13.2 vs 161.7 ± 2.9 104m2). O colágeno ao redor do núcleo lipídico é maior nos camundongos DKO do que nos LDLrKO (24.9 ± 1.8 vs 16.5 ± 2.5 % da placa). A distribuição do colágeno nos camundongos DKO ocorre principalmente ao redor da placa, de forma mais organizada, enquanto que nos LDLrKO onde sua distribuição é mais difusa. As placas...

A crucial role has been suggested for toll-like receptor 4 (TLR4) in atherosclerotic plaque formation and development. TLR4 was described primarily, as a receptor for gram-negative bacteria lipopolisacharide; later it was showed that its expression is increased in atherosclerotic plaques and patients that carries a TLR4 dysfunctional polymorphism are less susceptible to development of this disease. Therefore, the aim of this study was to investigate, in an experimental model of atherosclerosis, the influence of TLR4 deletion in atherosclerotic plaque formation and morphology, cholesterol profile and inflammatory markers. Double knockout mice (DKO), deficient in LDL receptor and TLR4, were generated by breeding LDL receptor knockout mice (LDLrKO) with TLR4 knockout mice (TLR4KO). All three experimental groups, LDLrKO, TLR4KO and DKO were fed a high fat-cholesterol diet for 12 weeks. Plasma cholesterol and triacylglicerol concentrations were measured by colorimetric assay. Cross sections of aortic sinus were stained with Oil red O and lesion areas were quantified by an image analyzer. Collagen content was measured by picrossirius staining. We also measured nitrotyrosine formation, CD40L, MMP9 and iNOS expression by immunohistochemistry. Comparisons were made by ANOVA followed by Student-Newman-Keuls post- test. Data are mean ± SEM. DKO mice developed smaller plaques than LDLrKO mice (117.6 ±1.4 vs 198.8 ± 3.3 104m2). TLR4KO mice developed no plaque. Plaques from DKO mice have also a smaller lipid core than the ones from LDLrKO mice (76.2± 13.2 vs 161.7 ± 2.9 104m2). Collagen content around the lipid core is higher in DKO mice compared to LDLrKO mice (24.9 ± 1.8 vs 16.5 ± 2.5 % of the whole plaque). Interestingly, collagen distribution in DKO mice seems to occur mainly on the plaque periphery, in a more organized manner, while in LDLrKO mice it is fuzzier, being present also inside the plaque. Plaques from DKO present lower expression of CD40L and iNOS...

Factors underlying the natural resistance of animals against snake venoms

The existence of mammals and reptilia with a natural resistance to snake venoms is known since a long time. This fact has been subjected to the study by several research workers. Our experiments showed us that in the marsupial Didelphis marsupialis, a mammal highly resistant to the venom of Bothrops jararaca, and other Bothrops venoms, has a genetically origin protein, a alpha-1, acid glycoprotein, now highly purified, with protective action in mice against the jararaca snake venom.