Enhancing the epidemiological surveillance of SARS-CoV-2 using Sanger sequencing to identify circulating variants and recombinants.

Since the emergence of SARS-CoV-2 in December 2019, more than 12,000 mutations in the virus have been identified. These could cause changes in viral characteristics and directly impact global public health. The emergence of variants is a great concern due to the chance of increased transmissibility and infectivity. Sequencing for surveillance and monitoring circulating strains is extremely necessary as the early identification of new variants allows public health agencies to make faster and more effective decisions to contain the spread of the virus. In the present study, we identified circulating variants in samples collected in Belo Horizonte, Brazil, and detected a recombinant lineage using the Sanger method. The identification of lineages was done through gene amplification of SARS-CoV-2 by Reverse Transcription-Polymerase Chain Reaction (RT-PCR). By using these specific fragments, we were able to differentiate one variant of interest and five circulating variants of concern. We were also able to detect recombinants. Randomly selected samples were sequenced by either Sanger or Next Generation Sequencing (NGS). Our findings validate the effectiveness of Sanger sequencing as a powerful tool for monitoring variants. It is easy to perform and allows the analysis of a larger number of samples in countries that cannot afford NGS.

Angiotensin-converting enzyme 2, the SARS-CoV-2 cellular receptor, is widely expressed in human myometrium and uterine leiomyoma.

OBJECTIVE: Angiotensin-converting-enzyme 2 (ACE2), the cell surface receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is found in a variety of reproductive tissues. The present study evaluated whether uterine fibroids and normal myometrium express ACE2 and, if so, at which tissue compartments. METHODS: We included 13 premenopausal women (age range 33-50 years, median 40 years) with uterine fibroids undergoing elective hysterectomy or myomectomy. Samples of leiomyoma (n = 12) and normal myometrial tissue (n = 8) were analyzed by immunohistochemistry for protein localization or by real time PCR for mRNA detection. RESULTS: In normal myometrium, ACE2 immunoreactivity was localized in smooth muscle fibers, arteriolar walls, and endothelial cells. In uterine leiomyoma, ACE2 staining was more intense in smooth muscle cells than in the extracellular matrix, and was also present in vascular endothelium. ACE2 mRNA was detected in myometrium as well as in fibroid samples. CONCLUSION: Human myometrium and uterine leiomyoma express ACE2 mRNA and have abundant distribution of ACE2 protein in their smooth muscle cells and microvasculature.

Histopathological Characterization of Mitral Valvular Lesions from Patients with Rheumatic Heart Disease. / Caracterização Histológica das Lesões da Valva Mitral de Pacientes com Cardiopatia Reumática.

BACKGROUND: The underlying mechanisms by which rheumatic heart disease (RHD) lead to severe valve dysfunction are not completely understood. OBJECTIVE: The present study evaluated the histopathological changes in mitral valves (MV) seeking an association between the pattern of predominant valvular dysfunction and histopathological findings. METHODS: In 40 patients who underwent MV replacement due to RHD, and in 20 controls that underwent heart transplant, histological aspects of the excised MV were analyzed. Clinical and echocardiographic data were also collected. Histological analyses were performed using hematoxylin-eosin staining. Inflammation, fibrosis, neoangiogenesis, calcification and adipose metaplasia were determined. A p value<0.05 was considered to be statistically significant. RESULTS: The mean age of RHD patients was 53±13 years, 36 (90%) were female, whereas the mean age of controls was 50±12 years, similar to the cases, with the majority of males (70%). The rheumatic valve endocardium presented greater thickness than the controls (1.3±0.5 mm versus 0.90±0.4 mm, p=0.003, respectively), and a more intense inflammatory infiltrate in the endocardium (78% versus 36%; p=0.004), with predominance of mononuclear cells. Moderate to marked fibrosis occurred more frequently in rheumatic valves than in control valves (100% vs. 29%; p<0.001). Calcification occurred in 35% of rheumatic valves, especially among stenotic valves, which was associated with the mitral valve area (p=0.003). CONCLUSIONS: Despite intense degree of fibrosis, the inflammatory process remains active in the rheumatic mitral valve, even at late disease with valve dysfunction. Calcification predominated in stenotic valves and in patients with right ventricular dysfunction.

FUNDAMENTOS: Os mecanismos subjacentes pelos quais a doença cardíaca reumática (DCR) levam à disfunção valvar grave não são totalmente compreendidos. OBJETIVO: O presente estudo avaliou as alterações histopatológicas nas valvas mitrais (VM) buscando uma associação entre o padrão de disfunção valvar predominante e os achados histopatológicos. MÉTODOS: Em 40 pacientes submetidos à troca da VM devido a DCR e em 20 controles submetidos a transplante cardíaco, foram analisados os aspectos histológicos da VM excisada. Dados clínicos e ecocardiográficos também foram coletados. As análises histológicas foram realizadas usando coloração com hematoxilina-eosina. Determinou-se inflamação, fibrose, neoangiogênese, calcificação e metaplasia adiposa. Valores de p<0,05 foram considerados estatisticamente significativos. RESULTADOS: A idade média dos pacientes com DCR foi de 53±13 anos, sendo 36 (90%) do sexo feminino, enquanto a idade média dos controles foi de 50±12 anos, semelhante aos casos, sendo a maioria do sexo masculino (70%). O endocárdio valvar reumático apresentou espessura maior que os controles (1,3±0,5 mm versus 0,90±0,4 mm, p=0,003, respectivamente), e infiltrado inflamatório mais intenso no endocárdio (78% versus 36%; p=0,004), com predominância de células mononucleares. Ocorreu fibrose moderada a acentuada mais frequentemente em válvulas reumáticas do que em válvulas controle (100% vs. 29%; p<0,001). Ocorreu calcificação em 35% das valvas reumáticas, principalmente entre as valvas estenóticas, associada à área valvar mitral (p=0,003). CONCLUSÕES: Apesar do intenso grau de fibrose, o processo inflamatório permanece ativo na valva mitral reumática, mesmo em doença tardia com disfunção valvar. A calcificação predominou em valvas estenóticas e em pacientes com disfunção ventricular direita.

Caracterização Histológica das Lesões da Valva Mitral de Pacientes com Cardiopatia Reumática / Histopathological Characterization of Mitral Valvular Lesions from Patients with Rheumatic Heart Disease

Resumo Fundamentos: Os mecanismos subjacentes pelos quais a doença cardíaca reumática (DCR) levam à disfunção valvar grave não são totalmente compreendidos. Objetivo: O presente estudo avaliou as alterações histopatológicas nas valvas mitrais (VM) buscando uma associação entre o padrão de disfunção valvar predominante e os achados histopatológicos. Métodos: Em 40 pacientes submetidos à troca da VM devido a DCR e em 20 controles submetidos a transplante cardíaco, foram analisados os aspectos histológicos da VM excisada. Dados clínicos e ecocardiográficos também foram coletados. As análises histológicas foram realizadas usando coloração com hematoxilina-eosina. Determinou-se inflamação, fibrose, neoangiogênese, calcificação e metaplasia adiposa. Valores de p<0,05 foram considerados estatisticamente significativos. Resultados: A idade média dos pacientes com DCR foi de 53±13 anos, sendo 36 (90%) do sexo feminino, enquanto a idade média dos controles foi de 50±12 anos, semelhante aos casos, sendo a maioria do sexo masculino (70%). O endocárdio valvar reumático apresentou espessura maior que os controles (1,3±0,5 mm versus 0,90±0,4 mm, p=0,003, respectivamente), e infiltrado inflamatório mais intenso no endocárdio (78% versus 36%; p=0,004), com predominância de células mononucleares. Ocorreu fibrose moderada a acentuada mais frequentemente em válvulas reumáticas do que em válvulas controle (100% vs. 29%; p<0,001). Ocorreu calcificação em 35% das valvas reumáticas, principalmente entre as valvas estenóticas, associada à área valvar mitral (p=0,003). Conclusões: Apesar do intenso grau de fibrose, o processo inflamatório permanece ativo na valva mitral reumática, mesmo em doença tardia com disfunção valvar. A calcificação predominou em valvas estenóticas e em pacientes com disfunção ventricular direita.

Abstract Background: The underlying mechanisms by which rheumatic heart disease (RHD) lead to severe valve dysfunction are not completely understood. Objective: The present study evaluated the histopathological changes in mitral valves (MV) seeking an association between the pattern of predominant valvular dysfunction and histopathological findings. Methods: In 40 patients who underwent MV replacement due to RHD, and in 20 controls that underwent heart transplant, histological aspects of the excised MV were analyzed. Clinical and echocardiographic data were also collected. Histological analyses were performed using hematoxylin-eosin staining. Inflammation, fibrosis, neoangiogenesis, calcification and adipose metaplasia were determined. A p value<0.05 was considered to be statistically significant. Results: The mean age of RHD patients was 53±13 years, 36 (90%) were female, whereas the mean age of controls was 50±12 years, similar to the cases, with the majority of males (70%). The rheumatic valve endocardium presented greater thickness than the controls (1.3±0.5 mm versus 0.90±0.4 mm, p=0.003, respectively), and a more intense inflammatory infiltrate in the endocardium (78% versus 36%; p=0.004), with predominance of mononuclear cells. Moderate to marked fibrosis occurred more frequently in rheumatic valves than in control valves (100% vs. 29%; p<0.001). Calcification occurred in 35% of rheumatic valves, especially among stenotic valves, which was associated with the mitral valve area (p=0.003). Conclusions: Despite intense degree of fibrosis, the inflammatory process remains active in the rheumatic mitral valve, even at late disease with valve dysfunction. Calcification predominated in stenotic valves and in patients with right ventricular dysfunction.

Mitral Regurgitation After Percutaneous Mitral Valvuloplasty: Insights Into Mechanisms and Impact on Clinical Outcomes.

OBJECTIVES: The aim of this study was to assess the incidence, mechanisms, and outcomes of mitral regurgitation (MR) after percutaneous mitral valvuloplasty (PMV). BACKGROUND: Significant MR continues to be a major complication of PMV, with a wide range in clinical presentation and prognosis. METHODS: Consecutive patients with mitral stenosis undergoing PMV were prospectively enrolled. MR severity was evaluated by using quantitative echocardiographic criteria, and its mechanism was characterized by 3-dimensional transesophageal echocardiography, divided broadly into 4 categories based on the features contributing to the valve damage. B-type natriuretic peptide levels were obtained before and 24 h after the procedure. Endpoints estimated cardiovascular death or mitral valve (MV) replacement due to predominant MR. RESULTS: A total of 344 patients, ages 45.1 ± 12.1 years, of whom 293 (85%) were women, were enrolled. Significant MR after PMV was found in 64 patients (18.6%). The most frequent mechanism of MR was commissural, which occurred in 22 (34.4%) patients, followed by commissural with posterior leaflet in 16 (25.0%), leaflets at central scallop or subvalvular damage in 15 (23.4%), and central MR in 11 (17.2%). During the mean follow-up period of 3 years (range 1 day to 10.6 years), 60 patients reached the endpoint. The event-free survival rates were similar among patients with mild or commissural MR, whereas patients with damaged central leaflet scallop or subvalvular apparatus had the worst outcome, with an event-free survival rate at 1 year of only 7%. Long-term outcome was predicted by net atrioventricular compliance (Cn) at baseline and post-procedural variables, including valve area, mean gradient, and magnitude of decrease in B-type natriuretic peptide levels, adjusted for the mechanism of MR. CONCLUSIONS: Significant MR following PMV is a frequent event, mainly related to commissural splitting, with favorable clinical outcome. Parameters that express the relief of valve obstruction and the mechanism by which MR develops were predictors of long-term outcomes.

Cardiac Involvement by Yellow Fever(from the PROVAR+ Study).

Incidence of Yellow Fever (YF) has increased in Brazil, and cardiac findings such as bradyarrhythmias and conduction abnormalities have been described. We aimed to perform a comprehensive cardiac evaluation of patients with YF, and to assess the association between cardiac involvement and disease severity. Patients hospitalized with YF from February to March 2018 underwent clinical and laboratory evaluation, focused bedside echocardiography (GE Vivid IQ), electrocardiogram and, in case of alterations, 24-hours Holter. Patients were divided into 2 groups according to YF severity. Five patients underwent magnetic resonance imaging and 3 had necropsy. Seventy patients had confirmed YF, 69% with severe form. Mean age was 48 ± 14 years, 63 (90%) were males and 5 (7%) died. Significant electrocardiogram abnormalities were present in 52% of patients with mild/moderate form of YF (G1) and 77% of those with severe form (G2), p = 0.046. Sinus bradycardia was observed in 24% (N = 17): G1 23% versus G2 25%, p = 0.67. Among 32 patients who underwent Holter, 14 (44%) had mean HR <60 beats per minute, being 8 from G2. Echocardiogram revealed left ventricular dysfunction in 4 (6%) patients, from G2. Left ventricular wall thickening with a hyper-refringent myocardial texture suggesting infiltration was observed in 17 patients (G1 18% vs G2 27%, p = 0.55). One magnetic resonance (G2) was suggestive of myocarditis, and one necropsy revealed areas of myocardial necrosis and acute myocarditis. In conclusion, cardiac involvement was observed in patients with YF, most commonly bradycardia and myocardial hyper-refringent texture suggestive of infiltration.

Helminths and Cancers From the Evolutionary Perspective.

Helminths include free-living and parasitic Platyhelminthes and Nematoda which infect millions of people worldwide. Some Platyhelminthes species of blood flukes (Schistosoma haematobium, Schistosoma japonicum, and Schistosoma mansoni) and liver flukes (Clonorchis sinensis and Opisthorchis viverrini) are known to be involved in human cancers. Other helminths are likely to be carcinogenic. Our main goals are to summarize the current knowledge of human cancers caused by Platyhelminthes, point out some helminth and human biomarkers identified so far, and highlight the potential contributions of phylogenetics and molecular evolution to cancer research. Human cancers caused by helminth infection include cholangiocarcinoma, colorectal hepatocellular carcinoma, squamous cell carcinoma, and urinary bladder cancer. Chronic inflammation is proposed as a common pathway for cancer initiation and development. Furthermore, different bacteria present in gastric, colorectal, and urogenital microbiomes might be responsible for enlarging inflammatory and fibrotic responses in cancers. Studies have suggested that different biomarkers are involved in helminth infection and human cancer development; although, the detailed mechanisms remain under debate. Different helminth proteins have been studied by different approaches. However, their evolutionary relationships remain unsolved. Here, we illustrate the strengths of homology identification and function prediction of uncharacterized proteins from genome sequencing projects based on an evolutionary framework. Together, these approaches may help identifying new biomarkers for disease diagnostics and intervention measures. This work has potential applications in the field of phylomedicine (evolutionary medicine) and may contribute to parasite and cancer research.

Influenza A Virus as a Predisposing Factor for Cryptococcosis.

Influenza A virus (IAV) infects millions of people annually and predisposes to secondary bacterial infections. Inhalation of fungi within the Cryptococcus complex causes pulmonary disease with secondary meningo-encephalitis. Underlying pulmonary disease is a strong risk factor for development of C. gattii cryptococcosis though the effect of concurrent infection with IAV has not been studied. We developed an in vivo model of Influenza A H1N1 and C. gattii co-infection. Co-infection resulted in a major increase in morbidity and mortality, with severe lung damage and a high brain fungal burden when mice were infected in the acute phase of influenza multiplication. Furthermore, IAV alters the host response to C. gattii, leading to recruitment of significantly more neutrophils and macrophages into the lungs. Moreover, IAV induced the production of type 1 interferons (IFN-α4/ß) and the levels of IFN-γ were significantly reduced, which can be associated with impairment of the immune response to Cryptococcus during co-infection. Phagocytosis, killing of cryptococci and production of reactive oxygen species (ROS) by IAV-infected macrophages were reduced, independent of previous IFN-γ stimulation, leading to increased proliferation of the fungus within macrophages. In conclusion, IAV infection is a predisposing factor for severe disease and adverse outcomes in mice co-infected with C. gattii.