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The mechanisms underlying regeneration of the central nervous system (CNS) following lesions have been studied extensively in both vertebrate and invertebrate models. To shed light on regeneration, ascidians, a sister group of vertebrates and with remarkable ability to regenerate their brains, constitute an appropriate model system. Glial cells have been implicated in regeneration in vertebrates; however, their role in the adult ascidian CNS regeneration is unknown. A model of degeneration and regeneration using the neurotoxin 3-acetylpyridine (3AP) in the brain of the ascidian Styela plicata was used to identify astrocyte-like cells and investigate their role. We studied the CNS of control ascidians (injected with artificial sea water) and of ascidians whose CNS was regenerating (1 and 10 days after the injection with 3AP). Our results show that the mRNA of the ortholog of glutamine synthetase (GS), a glial-cell marker in vertebrates, is increased during the early stages of regeneration. Confirming the identity of GS, the protein was identified via immunostaining in a cell population during the same regeneration stage. Last, a single ortholog of GS (GSII) is present in ascidian and amphioxus genomes, while two types exist in fungi, some invertebrates, and vertebrates, suggesting that ascidians have lost the GSI type. Taken together, our findings revealed that a cell population expressing glial-cell markers may play a role in regeneration in adult ascidians. This is the first report of astrocyte-like cells in the adult ascidian CNS, and contributes to understanding of the evolution of glial cells among metazoans., (© 2024 Wiley Periodicals LLC.)

Neurodegeneration is caused by the progressive loss of the structure and function of neurons, leading to cell death, and it is the main cause of many neurodegenerative diseases. Many molecules, such as glycosaminoglycans (GAGs), have been studied for their potential to prevent or treat these diseases. They are widespread in nature and perform an important role in neuritogenesis and neuroprotection. Here we investigated the neuritogenic and neuroprotective role of Phallusia nigra dermatan sulfate (PnD2,6S) and compared it with two distinct structures of chondroitin sulfate (C6S) and dermatan sulfate (D4S). For this study, a neuro 2A murine neuroblastoma cell line was used, and a chemical lesion was induced by the pesticide rotenone (ROT). We observed that PnD2,6S + ROT had a better neuritogenic effect than either C6S + ROT or D4S + ROT at a lower concentration (0.05 μg/mL). When evaluating the mitochondrial membrane potential, PnD2,6S showed a neuroprotective effect at a concentration of 0.4 μg/mL. These data indicate different mechanisms underlying this neuronal potential, in which the sulfation pattern is important for neuritogenic activity, while for neuroprotection all DS/CS structures had similar effects. This finding leads to a better understanding the chemical structures of PnD2,6S, C6S, and D4S and their therapeutic potential., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

We report the nearly complete genome sequences of CAstV-PK01 and CAstV-PK03, two canine astrovirus strains belonging to the species Mamastrovirus 5 , which were detected in fecal swab samples collected from puppies with diarrhea from two different kennels in the Brazilian Amazon.

Since the first reported case of COVID-19 in Brazil, the public and private educational system started to close. Up to November 2020, scientific discussions about the return of schooling activities have been rarely performed by the national scientific community and police-makers. The great delay of school returning in Brazil contrasts with successful international strategies of school reopening worldwide and seems counterintuitive with the reopening of non-essential activities. Here, important issues to be considered before and during school reopening are reviewed and discussed. COVID-19 testing is essential to avoid disease spreading, but high cost of individual RT-qPCRs impairs an extensive testing strategy for school returning. To reduce costs and increase the speed of diagnosis, we tested the efficiency of a pooled-sample PCR strategy in a cohort of the educational staff in the city of Macaé/RJ, finding five asymptomatic individuals (0,66%) among the 754 people tested. Thus, a polled-sample PCR testing strategy of the educational staff might prevent infection spreading in schools at a reasonable cost. We discuss how our test strategy could be coupled with internationally recognized safety rules to allow for a safe school return and how countries from different world regions are dealing with educational activities during COVID-19 pandemic.

Acute gastroenteritis is one of the main causes of mortality and morbidity worldwide, affecting mainly children, the immunocompromised and elderly people. Enteric viruses, especially rotavirus A, are considered important etiological agents, while long-term care facilities are considered favorable environments for the occurrence of sporadic cases and outbreaks of acute gastroenteritis. Therefore, it is important to monitor the viral agents present in nursing homes, especially because studies involving the elderly population in Brazil are scarce, resulting in a lack of available virological data. As a result, the causative agent remains unidentified in a large number of reported acute gastroenteritis cases. However, the advent of next-generation sequencing provides new opportunities for viral detection and discovery. The aim of this study was to identify the viruses that circulate among elderly people with and without acute gastroenteritis, living in residential care homes in Belém, Pará, Brazil, between 2017 and 2019. Ninety-three samples were collected and screened by immunochromatography and qPCR. After, the samples were analyzed individually or in pools by next generation sequencing to identify the viruses circulating in this population. In 26 sequenced samples, members of 13 eukaryotic virus families were identified. The most abundantly present virus families were Parvoviridae, Genomoviridae and Smacoviridae. Contigs displaying similarity to pegiviruses were also detected. Furthermore, a near-complete rotavirus A genome was obtained and could be classified as G3P[8] genotype with the equine DS-1-like genetic background. Complete sequences of the VP4 and VP7 genes of a rotavirus C were also detected, belonging to G4P[2]. This study demonstrates the first characterization of the gastrointestinal virome in elderly in Northern Brazil. A diversity of viruses was found to be present in patients with and without diarrhea, reinforcing the need to monitor elderly people residing in long-term care facilities, especially in cases of acute gastroenteritis., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

The Brazilian strategy to overcome the spread of COVID-19 has been particularly criticized due to the lack of a national coordinating effort and an appropriate testing program. Here, a successful approach to control the spread of COVID-19 transmission is described by the engagement of public (university and governance) and private sectors (hospitals and oil companies) in Macaé, state of Rio de Janeiro, Brazil, a city known as the National Oil Capital. In 2020 between the 17th and 38th epidemiological week, over two percent of the 206,728 citizens were subjected to symptom analysis and RT-qPCR testing by the Federal University of Rio de Janeiro, with positive individuals being notified up to 48 h after swab collection. Geocodification and spatial cluster analysis were used to limit COVID-19 spreading in Macaé. Within the first semester after the outbreak of COVID-19 in Brazil, Macaé recorded 1.8% of fatalities associated with COVID-19 up to the 38th epidemiological week, which was at least five times lower than the state capital (10.6%). Overall, considering the successful experience of this joint effort of private and public engagement in Macaé, our data suggest that the development of a similar strategy countrywise could have contributed to a better control of the COVID-19 spread in Brazil. Quarantine decree by the local administration, comprehensive molecular testing coupled to scientific analysis of COVID-19 spreading, prevented the catastrophic consequences of the pandemic as seen in other populous cities within the state of Rio de Janeiro and elsewhere in Brazil., (© 2021. The Author(s).)

Dopamine (DA) is an important molecule that plays a role in the nervous and immune systems. DA is produced by a wide variety of animals and it is considered one of the oldest neurotransmitters. However, its specific function in immune cells has not been completely revealed. In a group of chordate animals, the ascidians, DA is reported to be produced by cells in the central nervous system (CNS); however, no dopaminergic receptor in their genomes has been described until now. Because this is an integrating characteristic of the ascidian dopamine system, here it was investigated the pharmacology, function, and phylogeny of DA and dopaminergic receptors (DRs) in the modulation of nitric oxide (NO) in the Phallusia nigra immune cells. The data disclosed, for the first time, that DA modulates NO production by immune cells. Its modulation probably occurs though adrenergic receptors, which display a special characteristic, in that they are capable of binding to noradrenaline (NA) and DA. A pharmacological analysis revealed that receptors present on the ascidian immune cells showed a high affinity to butaclamol, a non-selective D2-class receptor, increasing NO production. In addition, calcium intracellular mobilization was observed when DA was added to immune cells. In conclusion, the data revealed novel insights about the presence of catecholaminergic receptors (CRs) on the P. nigra immune cells, indicating that ascidian CRs have special pharmacological characteristics that are worth highlighting from an evolutionary point of view., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Enteric adenovirus (AdV), sapovirus (SaV), and human astrovirus (HAstV) are important pathogens involved in the gastroenteritis etiology. In this study, a total of 219 fecal samples and sera were collected from children hospitalized for acute gastroenteritis (AGE) in two large pediatric hospitals in Belém, from March 2012 to April 2015. The samples were analyzed by polymerase chain reaction (PCR) for AdV and HAstV (astrovirus) detection, and Nested-PCR and qPCR for SaV detection. AdV was detected in 50.2% (110/219) of the cases, with 42.7% (47/110) being sequenced and classified as: species F (63.9% - 30/47), A (4.2% - 2/47), B (6.4% - 3/47), C (17.1% - 8/47), D (4.2% - 2/47), and E (4.2% - 2/47). Of the 110 AdV-positive feces samples, 80 paired sera presented sufficient amounts and were also tested for this virus, of which 51 (63.7%) showed positive results and 26 (70.3%) pairs (feces plus sera) presented concordant results after sequencing being classified as: species F (21/26; 80.8%), A (1/26; 3.8%), B (1/26; 3.8%), and C (3/26; 11.5%). Overall, HAstV rate in the feces samples was 1.8% (4/219), including both HAstV-1a (2/4; 50%) and HAstV-2c (2/4; 50%). SaV was detected in 4.6% (10/219) of the fecal samples, out of which 50% (5/10) of the positive samples were characterized into the genogroups GI.1 (1), GI.2 (2), and GII.4 (2). These findings highlighted the important contributions of AdV, HAstV, and SaV in the enteric virus spectrum in our region and showed the high genetic diversity of AdV. In addition, it demonstrated for the first time in Brazil, the circulation of AdV in the serum of hospitalized children with AGE., (© 2018 Wiley Periodicals, Inc.)

Introduction: Acute gastroenteritis (AGE) is one of the most common causes of morbidity and mortality, especially among children from developing countries. Human adenovirus (HAdV) and sapovirus (SaV) are among the agents that cause AGE. The present study aimed to detect and genotype HAdV and SaV in 172 fecal samples from children with AGE, collected during a surveillance study carried out in a low-income community in Belém, Pará, between 1990 and 1992., Methods: HAdV was detected by nested PCR, using primers Hex1deg/Hex2deg and NeHex3deg/NeHex4deg. SaV was assayed by reverse transcription PCR (RT-PCR), nested PCR, and quantitative PCR. The nucleotide sequence was determined by direct cycle sequencing., Results: Overall, 43% (74/172) of samples were positive for HAdV, of which 70.3% (52/74) were sequenced and classified as belonging to five different species, mostly A and F. For SaV, positivity was 5.2% (9/172) and genotypes GI.1, GI.7, GII.1, and GV.2 were detected., Conclusions: The present results reinforce the need for further studies to obtain epidemiological data about the circulation of these viruses in Brazil, especially in the Amazon Region, where data from the early 1990's are scarce. Furthermore, the study describes for the first time the detection of SaV genotypes GI.7 and GV.2 in Brazil, showing that these types circulated in the region more than 25 years ago.

Background: Astrovirus (HAstV) is a common viral pathogen that causes gastroenteritis worldwide. It is classified into eight classical human types (HAstV-1/8) and seven other less prevalent types, described as HAstV VA1, VA2, VA3, VA4, MLB-1, MLB-2 and MLB-3. During outbreaks, the elderly and children are the most affected, and the spread of the virus is associated with person-to-person contact, food ingestion and contaminated water., Objectives: The aim of the present study was to investigate the prevalence of infection and genetic diversity of HAstV strains. Samples were collected from children with acute gastroenteritis admitted to a large pediatric hospital during a surveillance period of three years (2008-2011) in Belém city, Pará State, Amazon Region, Northern Brazil., Study Design: Screening and genotyping tests were conducted using RT-PCR to detect the classical and non-classical HAstV types using specific primers. A semi-nested RT-PCR protocol was developed to improve viral detection in samples with a low viral load., Results: The overall positivity observed in this study was 3.9% (19/483). The age distribution showed a high prevalence of positive cases in children under one year old (5.3%). We found vomiting associated with 75% of the positive cases, fever with 82.3%, and dehydration with 76.9%. Most patients with positive cases demonstrated two to five days of diarrhea, two to three episodes of vomiting during hospitalization, and three bowel movements per day. Co-infection with HAstV and norovirus was observed in three cases (15.8%), and no pattern of seasonality or any relationship between the HAstV positivity rate and climate variables was observed. Eighteen positive samples (94.7%-18/19) were genotyped based on the ORF 2 region, and the greatest prevalence was of HAstV-1a (66.6%-12/18), followed by HAstV-2 (22.2%-4/18, comprising two type-2b and two type-2c genotypes), HAstV-3c (5.6%-1/18) and HAstV-4c (5.6%-1/18). No non-classical types were detected in the clinical samples analyzed., Conclusions: The present study showed that although HAstV infections occur at low frequency, they are involved in severe pediatric cases of acute gastroenteritis presenting with a high diversity of strains, including the lineages 3c and 4c, which were never before detected in Brazil., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Gastroenteritis is one of the most common diseases during childhood, with norovirus (NoV) and sapovirus (SaV) being two of its main causes. This study reports for the first time the incidence of these viruses in hospitalized children with and without gastroenteritis in São Luís, Maranhão. A total of 136 fecal samples were tested by enzyme immunoassays (EIA) for the detection of NoV and by reverse transcription-polymerase chain reaction (RT-PCR) for detection of both NoV and SaV. Positive samples for both agents were subjected to sequencing. The overall frequency of NoV as detected by EIA and RT-PCR was 17.6% (24/136) and 32.6% (15/46), respectively in diarrheic patients and 10.0% (9/90) in non-diarrheic patients (p<0.01). Of the diarrheic patients, 17% had fever, vomiting and anorexia, and 13% developed fever, vomiting and abdominal pain. Of the 24 NoV-positive samples, 50% (12/24) were sequenced and classified as genotypes GII.3 (n=1), GII.4 (6), GII.5 (1), GII.7 (2), GII.12 (1) and GII.16 (1). SaV frequency was 9.8% (11/112), with 22.6% (7/31) in diarrheic patients and 4.9% (4/81) in nondiarrheic (p=0.04) ones. In diarrheic cases, 27.3% had fever, vomiting and anorexia, whereas 18.2% had fever, anorexia and abdominal pain. One SaV-positive sample was sequenced and classified as GII.1. These results show a high genetic diversity of NoV and higher prevalence of NoV compared to SaV. Our data highlight the importance of NoV and SaV as enteropathogens in São Luís, Maranhão., (Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.)

Sapoviruses (SaVs) belong to the family Caliciviridae and are related to gastroenteritis viruses of humans and animals. These agents have been reported from several countries of the world and represent an important cause of economic loss. The Amazon area has a high degree of diversity of animals and plants, is located in the Northern Region of Brazil and accounts for a large part of the Brazilian territory. In this study, stool samples were collected from pigs during the phase of nursing (less than 28 days of age) and post-weaning (29 to 56 days of age) from January 2008 to February 2009. A total of 169 specimens (108 nursing and 61 post-weaning pigs) were tested by reverse transcription polymerase chain reaction (RT-PCR) using the primers p289/p290 for the detection of caliciviruses (CVs), i.e., SaVs and noroviruses (NoVs). Positive sequences were analyzed using BioEdit software (v. 7.1.3.0) and compared with other sequences registered in the GenBank database. A positive frequency of 12.4 % (21/169) was observed, and all of the viruses found were identified as SaVs, with 15 belonging to genogroup GIII (71.4 %), three to GVII-1 (14.3 %) and three to GVIII-2 (14.3 %). No NoVs were detected. The frequency of SaV infections was significantly higher in nursing pigs (17.6 %-19/108) than in post-weaning pigs (3.3 %-2/61). Considering the consistency of the samples, 14.7 % of the samples were classified as diarrheic, but statistical analysis demonstrated that there was no significant difference compared to normal specimens (p = 0.5795). For the first time, we have demonstrated the circulation of SaVs in pigs from the Amazon.