Primary infection of BALB/c mice with a dengue virus type 4 strain leads to kidney injury

BACKGROUND Dengue is a disease caused by dengue virus (DENV-1 through -4). Among the four serotypes, DENV-4 remains the least studied. Acute kidney injury is a potential complication of dengue generally associated with severe dengue infection. OBJECTIVES The goal of this study was to investigate the alterations caused by experimental dengue infection in the kidney of adult BALB/c mice. METHODS In this study, BALB/c mice were infected through the intravenous route with a DENV-4 strain, isolated from a human patient. The kidneys of the mice were procured and subject to histopathological and ultrastructural analysis. FINDINGS The presence of the viral antigen was confirmed through immunohistochemistry. Analysis of tissue sections revealed the presence of inflammatory cell infiltrate throughout the parenchyma. Glomerular enlargement was a common find. Necrosis of tubular cells and haemorrhage were also observed. Analysis of the kidney on a transmission electron microscope allowed a closer look into the necrotic tubular cells, which presented nuclei with condensed chromatin, and loss of cytoplasm. MAIN CONCLUSIONS Even though the kidney is probably not a primary target of dengue infection in mice, the inoculation of the virus in the blood appears to damage the renal tissue through local inflammation.

Monkeypox (Mpox) virus isolation and ultrastructural characterisation from a Brazilian human sample case

BACKGROUND According to the last 2023 Monkeypox (Mpox) Outbreak Global Map from the Centres for Disease Control and Prevention (CDC), more than 100 countries with no Mpox infection report cases. Brazil stands out in this group and is the second country with the highest number of cases in the last outbreak. OBJECTIVE To contribute to knowledge of the virus infection effects in a cellular model, which is important for diagnosis infections not yet included in a provider´s differential diagnosis and for developing viral inhibition strategies. METHODS We describe a virus isolation protocol for a human clinical sample from a patient from Brazil, the viral growth in a cell model through plaque forming units (PFU) assay, reverse transcriptase polymerase chain reaction (RT-PCR) and transmission electron microscopy (TEM). FINDINGS We follow the viral isolation in Vero cell culture from a Mpox positive clinically diagnosed sample and show the infection effects on cellular structures using a TEM. MAIN CONCLUSIONS Understanding the impact of viral growth on cellular structures and its replication kinetics may offer better strategies for the development of new drugs with antiviral properties.

Modelo murino imunocompetente para estudo da infecção pelo vírus dengue sorotipo 3: aspectos morfológicos, viremia e tropismo / Immunocompetent murine model for studying dengue serotype 3 virus infection: morphological aspects, viremia and tropism

Diversos estudos epidemiológicos já correlacionaram a infecção pelo DENV-3 a quadros graves, tanto em infecções primárias quanto secundárias e, no Brasil, este sorotipo apresenta maior associação a sinais e sintomas mais graves, incluindo choque, dor abdominal e exantema, em comparação aos demais sorotipos. O estabelecimento de modelos animais para estudos das infecções pelos DENV é de grande relevância para a pesquisa sobre patogênese, imunidade, desenvolvimento e teste de fármacos e candidatas a vacinas. Porém, para tal, são inúmeros os desafios, uma vez que os vírus epidêmicos circulantes não infectam naturalmente espécies não-humanas. Diante deste cenário, este estudo teve como objetivo principal verificar através de análises de hemograma, bioquímicas, morfológicas e moleculares possíveis alterações histopatológicas e fisiopatológicas, assim como a presença do genoma do DENV em diferentes órgãos, soro, saliva e urina de camundongos BALB/c infectados experimentalmente com o DENV-3 epidêmico e não neuroadaptado

Camundongos BALB/c machos, de 2 meses de idade foram infectados com DENV-3 pela via intravenosa e eutanasiados em 72 h.p.i, 7 e 14 d.p.i, de acordo com as análises a serem realizadas. Análises histopatológicas, ultraestruturais e histomorfométricas a partir de amostras de todos os órgãos estudados revelaram alterações semelhantes às observadas em casos humanos de DEN. Partículas semelhantes aos DENV foram detectadas em célula intersticial renal. Discretas alterações bioquímicas, como a elevação do nível de creatinina e ureia e diminuição do nível de colesterol total foram observadas nos camundongos infectados, ao longo da cinética experimental. Em relação às alterações no hemograma, foi observado aumento do hematócrito e diminuição da contagem de plaquetas nos camundongos infectados. Apesar de ter sido observada baixa viremia em camundongos 72 h.p.i, o genoma viral foi detectado em todos os órgãos testados, além da saliva. Estes resultados demonstram a suscetibilidade do camundongo BALB/c à infecção pelo DENV-3. (AU)

High prevalence of insulin resistance among Brazilian chronic hepatitis C patients

ABSTRACT Objective: This study aims to estimate the prevalence of insulin resistance (IR) among chronic hepatitis C (CHC) patients and their related laboratory and demographic data. Subjects and methods: In this study, non-diabetic CHC patients referred to Viral Hepatitis Ambulatories from Rio de Janeiro (Brazil) donated blood samples. Insulin was measured using a chemiluminescence immunoassay. IR was determined by HOMA-IR, where HOMA-IR > 2 was defined as IR. Results: A total of 214 CHC patients were recruited (123 females aged 53.6 years ± 10.9 years). IR was present in 133 patients (62.1%) and was associated in bivariate analysis to higher mean values of age (p = 0.040), triglycerides (p = 0.032), glucose (p = 0.000), insulin (p = 0.000), waist circumference (p = 0.001), and body mass index (p = 0.007); however, none of these variables were significant in the multivariate analysis. Conclusions: The high prevalence of IR was observed among CHC patients, and there was no difference in clinical or laboratory parameters when both groups were compared in the multivariate analysis. This high IR prevalence could lead to a high risk for development of cardiovascular disease and metabolic disorders.