ABSTRACT
SARS-CoV-2 infection during pregnancy is not usually associated with significant adverse effects. However, in this study, we report a fetal death associated with mild COVID-19 in a 34-week-pregnant woman. The virus was detected in the placenta and in an unprecedented way in several fetal tissues. Placental abnormalities (MRI and anatomopathological study) were consistent with intense vascular malperfusion, probably the cause of fetal death. Lung histopathology also showed signs of inflammation, which could have been a contributory factor. Monitoring inflammatory response and coagulation in high-risk pregnant women with COVID-19 may prevent unfavorable outcomes, as shown in this case.
ABSTRACT
BACKGROUND: Neurological and other systemic complications occur in adults with severe COVID-19. Here we describe SARS-CoV-2 infection complicated by neuroinvasion in the post-mortem tissues of a child. METHODS: We performed a complete autopsy of a 14-month-old child who died of COVID-19 pneumonitis. Histological sections of multiple organs were stained with haematoxylin and eosin. Luxol fast blue staining for myelin and immunohistochemistry were performed in selected areas of the brain. The presence of SARS-CoV-2 was investigated by immunostaining with anti-spike protein antibody and by RT-qPCR. FINDINGS: Lesions included microthrombosis, pulmonary congestion, interstitial oedema, lymphocytic infiltrates, bronchiolar injury, collapsed alveolar spaces, cortical atrophy, and severe neuronal loss. SARS-CoV-2 staining was observed along the apical region of the choroid plexus (ChP) epithelium and in ependymal cells of the lateral ventricle, but was restricted to ChP capillaries and vessels in some regions. SARS-CoV-2 infection of brain tissue was confirmed by RT-qPCR in fragments of the ChP, lateral ventricle, and cortex. INTERPRETATION: Our results show multisystemic histopathological alterations caused by SARS-CoV-2 infection and contribute to knowledge regarding the course of fatal COVID-19 in children. Furthermore, our findings of ChP infection and viral neurotropism suggest that SARS-CoV-2 may invade the central nervous system by blood-cerebrospinal fluid barrier disruption. FUNDING: Carlos Chagas Filho Foundation for Supporting Research in the State of Rio de Janeiro (FAPERJ); the National Council for Scientific and Technological Development (CNPq) and Coordination for the Improvement of Higher Education Personnel (CAPES), in addition to intramural grants from D'Or Institute for Research and Education. EDITOR'S NOTE: This translation in Portuguese was submitted by the authors and we reproduce it as supplied. It has not been peer reviewed. Our editorial processes have only been applied to the original abstract in English, which should serve as reference for this manuscript. RESUMO: Complicações sistêmicas e neurológicas foram descritas em adultos com COVID-19 grave. Neste trabalho, descrevemos a infecção por SARS-CoV-2, incluindo sua neuroinvasão, nos tecidos post-mortem de uma criança. MÉTODOS: Realizamos a autópsia completa de uma criança de 14 meses que morreu de pneumonite por COVID-19. Cortes histológicos de múltiplos órgãos foram corados com Hematoxilina e Eosina. A coloração de Luxol Fast Blue para mielina e imuno-histoquímica foram realizadas em áreas selecionadas do cérebro. A presença de SARS-CoV-2 foi investigada por imunomarcação com anticorpo anti-proteína spike e por RT-qPCR. ACHADOS: As lesões incluíram microtrombose, congestão pulmonar, edema intersticial, infiltrados linfocíticos, lesão bronquiolar, colapso dos espaços alveolares, atrofia cortical e perda neuronal grave. A presença de SARS-CoV-2 foi observada ao longo da região apical do epitélio do plexo coróide (PC) e nas células ependimárias do ventrículo lateral, mas ficou restrita aos capilares e vasos do PC em outras regiões. A infecção do tecido cerebral por SARS-CoV-2 foi confirmada por RT-qPCR em fragmentos do PC, ventrículo lateral e cortex cerebral. INTERPRETAÇÃO: Nossos resultados mostram alterações histopatológicas multissistêmicas causadas pela infecção por SARS-CoV-2 e contribuem para ampliar o conhecimento sobre a evolução da COVID-19 fatal em crianças. Além disso, nossos achados sobre a infecção no PC e neurotropismo viral sugerem que o SARS-CoV-2 pode invadir o sistema nervoso central pela ruptura da barreira sangue-líquido cefalorraquidiano. FINANCIAMENTO: Fundação de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) e Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), além de financiamento intramural do Instituto D'Or de Pesquisa e Educação.
ABSTRACT
Coronavirus disease 2019 (COVID-19) was initially described as a viral infection of the respiratory tract. It is now known, however, that several other organs are affected, including the brain. Neurological manifestations such as stroke, encephalitis, and psychiatric conditions have been reported in COVID-19 patients, but the neurotropic potential of the virus is still debated. Herein, we sought to investigate SARS-CoV-2 infection in human neural cells. We demonstrated that SARS-CoV-2 infection of neural tissue is non-permissive, however, it can elicit inflammatory response and cell damage. These findings add to the hypothesis that most of the neural damage caused by SARS-CoV-2 infection is due to a systemic inflammation leading to indirect harmful effects on the central nervous system despite the absence of local viral replication.
Subject(s)
COVID-19 , SARS-CoV-2 , Brain , Humans , InflammationABSTRACT
Coronavirus disease 2019 (COVID-19) was initially described as a viral infection of the respiratory tract. It is now known, however, that several other organs are affected, including the brain. Neurological manifestations such as stroke, encephalitis, and psychiatric conditions have been reported in COVID-19 patients, but the neurotropic potential of the virus is still debated. Herein, we sought to investigate SARS-CoV-2 infection in human neural cells. We demonstrated that SARS-CoV-2 infection of neural tissue is non-permissive, however, it can elicit inflammatory response and cell damage. These findings add to the hypothesis that most of the neural damage caused by SARS-CoV-2 infection is due to a systemic inflammation leading to indirect harmful effects on the central nervous system despite the absence of local viral replication.
ABSTRACT
This study aimed to evaluate the effects of three solvent extractors (water, ethanol and hexane) of grounded seeds of soursop, Annona muricata L. (Annonaceae), in the mortality, biology and oviposition of Plutella xylostella L. (Lepidoptera: Plutellidae). The results showed that the LC50 and LC99 were 0.0133 and 0.084%, 0.025% and 0.196%, 2.33 and 35.22% for the ethanolic, hexanic and aqueous extracts, respectively. The organic extracts affected only the larval phase and reduced viability in more than 60%, but did not affect pupal stage of the remaining larvae. Furthermore, the ethanolic extract at lethal concentraction also affected negatively the embryonic phase. The results lead to the conclusion that the ethanolic extract of soursop grounded seeds is a viable alternative to control diamondback moth on vegetables.
O presente trabalho teve como objetivo avaliar o efeito de extratos de sementes de graviola, Annona muricata L. (Annonaceae) obtidos com diferentes solventes sobre Plutella xylostella L. (Lepidoptera: Plutellidae). Foram estimadas as concentrações letais de três solventes extratores (água, hexano e etanol) e seus efeitos na biologia e oviposição. Os valores estimados das concentrações letais foram de 0,013 e 0,084%; 0,025 e 0,196%; 2,33 e 35,22%, para as CL50 e CL99 do extrato etanólico, hexânico e aquoso, respectivamente. Os extratos orgânicos afetaram apenas a fase larval e reduziu a viabilidade em mais de 60%, mas não afetou a fase pupal das lagartas remanescentes. Além disso, o extrato etanólico na concentração letal se mostrou eficiente afetando negativamente a fase embrionária. Conclui-se que o extrato etanólico da graviola é uma alternativa viável no controle da traça.
Subject(s)
Plant Extracts , Annona/toxicity , LepidopteraABSTRACT
Coumarin, o-coumaric, and kaurenoic acid are bioactive compounds usually found in the leaves of Mikania laevigata. Genetic and environmental variations in the secondary metabolites of plants may have implications for their biological effects. Three different accessions of M. laevigata cultivated in four sites between the Equator and the Tropic of Capricorn in Brazil were evaluated aiming to present potential raw materials and discuss relationships among these three bioactive compounds. The results revealed effects of plant accessions and environmental factors and suggested two contrasting chemical phenotypes of M. laevigata. The first phenotype presented the highest levels of kaurenoic acid (2283 ± 316 mg/100 g) besides lower levels of coumarin (716 ± 61 mg/100 g), which was also stimulated by the environment and mild climate at the site nearest to the Tropic of Capricorn. The other phenotype presented the lowest levels of kaurenoic acid (137 ± 17 mg/100 g) besides higher levels of coumarin (1362 ± 108 mg/100 g), which was also stimulated by the environment and tropical climate at the site nearest to the Equatorial beach.
Subject(s)
Coumarins/analysis , Diterpenes/analysis , Mikania/chemistry , Coumaric Acids/analysis , Environment , PhenotypeABSTRACT
ABSTRACT: The aim of this study was to evaluate the bioactivity of microencapsulated extract from the soursop seeds, Annona muricata L. (Annonaceae), on diamondback moth, Plutella xylostela L. (Lepidoptera: Plutellidae). Microencapsulation was performed in a Mini Spray Dryer model B-290 using 50mL of ethanolic and hexanic extracts plus 150mL of ethanol and 150mL of ultrapure water, mixed with aerosil (first polymer) or arabic gum (second polymer). It was possible to microencapsulate the ethanolic extract of soursop seeds only by using the polymer arabic gum at 20%. The microencapsulated extract caused significant acute toxicity (LC50=258mg L-1) and chronic effects, especially reduction of larval viability and increased larval stage. We concluded that the microencapsulation of the ethanolic extract of soursop seeds can be a viable alternative for controlling diamondback moth with possible gains for the environment.
RESUMO: O objetivo deste estudo foi avaliar a bioatividade do extrato microencapsulado das sementes de graviola, Annona muricata L. (Annonaceae), sobre a traça-das-crucíferas, Plutella xylostella L. (Lepidoptera: Plutellidae). A microencapsulação foi realizada em um Mini Spray Dryer modelo B-290 utilizando-se 50mL dos extratos etanólico e hexânico mais 150mL de álcool etílico e 150mL de água ultrapurificada, misturado com aerosil (primeiro polímero) ou com goma arábica (segundo polímero). Só foi possível microencapsular o extrato etanólico de sementes de graviola com a utilização do polímero goma arábica a 20%. O extrato microencapsulado causou significativa toxicidade aguda (CL50=258mg L-1) e efeitos crônicos, especialmente redução da viabilidade larval e aumento da duração do estágio larval. Conclui-se que a microencapsulação do extrato etanólico da semente de graviola pode ser uma alternativa viável no controle da traça com possíveis ganhos para o meio ambiente.
ABSTRACT
Currently, stem cell research faces a major bottleneck related to the low efficiency of methods to produce large quantities of human embryonic stem cells (ESC) for use in clinical trials. Most culture media currently employed for human ESC cultivation contain animal compounds, and cells are grown in static flasks. Besides the immediate contamination with nonhuman compounds, cell expansion in flasks tends to be laborious and nonefficient. Here we cultured human ESC in stirred microcarrier (MC) systems using an animal/human-component-free medium, to overcome both issues. The method developed to culture cells on suspended beads combined the use of polymeric MCs in stirred vessels with an optimized culture medium free of supplements of animal and human origin. This approach generated approximately 160 million cells within 6 days, which were shown to remain pluripotent. The process developed herein provides a step forward toward therapy due to the economic advantages in the production of human ESC and to their consequent low immunogenic potential.
Subject(s)
Bioreactors , Embryonic Stem Cells/cytology , Animals , Base Sequence , Cell Line , Culture Media , DNA Primers , Humans , Microscopy, Electron, Scanning , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
Embryonic stem (ES) cells are pluripotent cells derived from the inner cell mass of blastocyst-stage early mammalian embryos. A crucial stage in the differentiation of ES cells is the formation of embryoid bodies (EBs) aggregates. EB formation is based on spontaneous aggregation when ES cells are cultured in non adherent plates. Three-dimensional EB recapitulates many aspects of early mammalian embryogenesis and differentiate into the three germ layers: ectoderm, mesoderm and endoderm. Immunofluorescence and in situ hybridization are widely used techniques for the detection of target proteins and mRNA present in cells of a tissue section. Here we present a simple technique to generate high quality cryosections of embryoid bodies. This approach relies on the spatial orientation of EB embedding in OCT followed by the cryosection technique. The resulting sections can be subjected to a wide variety of analytical procedures in order to characterize populations of cells containing certain proteins, RNA or DNA. In this sense, the preparation of EB cryosections (10 µm) are essential tools for histology staining analysis (e.g. Hematoxilin and Eosin, DAPI), immunofluorescence (e.g. Oct4, nestin) or in situ hybridization. This technique can also help to understand aspects of embryogenesis with regards to the maintenance of the tri-dimensional spherical structure of EBs.
