Brief dispersion of a putative B.1.1.28-derived SARS-CoV-2 lineage harboring additional N234P and E471Q spike protein mutations in individuals crossing the Argentina-Brazil border.

BACKGROUND: SARS-CoV-2, the virus that causes COVID-19, is constantly mutating, leading to new variants that culminate in a temporal lineages fluctuation. B.1.1.28 lineage has been evolving in Brazil since February 2020 and originated P.1 (VOC), P.2 (VOI) and other P.Xs proposed as new variants. METHODS AND RESULTS: In this study, through the Illumina platform, we performed the whole-genome sequencing of 26 positive samples of SARS-CoV-2. Employing variant calling analysis on FASTQ reads and phylogenetic inference, we report a brief dispersion of a potentially new B.1.1.28-derived variant detected between 2021 May and June in individuals crossing the border between Brazil and Argentina, and local spread to inpatients from hospitals at the Rio Grande do Sul state capital (Porto Alegre). Besides, the Rio Grande do Sul State SARS-CoV-2 genomic epidemiological data was analyzed and showed an important B.1.1.28 peak in RS at the same period (May-June), even in the presence of a major Gamma wave. CONCLUSIONS: The emergence of a putative B.1.1.28-derived lineage was identified in travelers crossing Brazil-Argentina border representing an important peak of B.1.1.28 in RS State with a decreased in Gamma variant frequency in the same period of time.

Low brain-derived neurotrophic factor levels are associated with active disease and poor prognosis in childhood acute leukemia.

BACKGROUND: Brain-derived neurotrophic factor (BDNF) and its receptor, tropomyosin-related receptor kinase B (TrkB) are involved in the maturation of B lymphocytes in the bone marrow (BM), promote cell differentiation in B-cell malignancies, and are associated with poor prognosis in adults with acute leukemia (AL). However, the role of BDNF in pediatric AL remains poorly understood. OBJECTIVE: We carried out a cohort observational study to evaluate BDNF levels in BM or peripheral blood (PB) samples from children with AL. METHODS: BM or PB samples were collected from 57 children and adolescents with acute lymphoid leukemia (ALL), 14 children and adolescents with acute myeloid leukemia (AML), and 44 healthy individuals (HI) of the same age range. RESULTS: BDNF levels at diagnosis in AL patients were significantly lower when compared to HI. Samples from patients in complete remission from disease had higher levels of BDNF compared to those obtained from patients with malignant cells. Moreover, BDNF levels at diagnosis in patients who died were significantly lower compared to those found in survivors. CONCLUSIONS: These findings provide the first evidence for a possible role of BDNF as a marker of active disease and poor prognosis in pediatric AL.

Possible enhancement of long-term fear conditioning performance by cisplatin administration in rats / Possível facilitação do desempenho em condicionamento aversivo por administração de cisplatina em ratos

Neurocognitive deficits associated with chemotherapy represent an increasing concern, and the development of animal models to investigate chemotherapy-induced alterations in memory is warranted. Aims: to examine the effects of systemic injection of cisplatin on formation of fear-motivated memory in rats. Methods: male Wistar rats were given an intraperitoneal (i.p.) injection of saline or cisplatin followed by inhibitory avoidance (IA) training. Memory retention was tested 1 and 7 days after training. Control experiments using an open field were carried out to confirm the specificity of the cisplatin-induced alteration in IA performance. Results: cisplatin induced a unexpected enhancement of IA performance measured 7 days after drug injection and training. Control experiments suggested that the effect could not be attributed to sensorimotor alterations or toxic effects. Discussion: the findings are discussed in the light of previous preclinical evidence that cancer chemotherapy can, under some conditions, lead to memory enhancement

É crescente a preocupação com disfunções cognitivas associadas ao uso de quimioterapia para tratamento de câncer. É necessário o desenvolvimento de modelos experimentais que permitam avaliar alterações na memória induzidas por antineoplásicos. Objetivos: avaliar os efeitos da administração sistêmica de cisplatina sobre a formação de memória motivada por medo em ratos. Métodos: ratos Wistar machos receberam uma injeção intraperitoneal (i.p.) de solução salina (controles) ou cisplatina antes de uma sessão de treino em esquiva inibitória (EI). A retenção da memória de EI foi avaliada em testes realizados 1 e 7 dias depois do treino. Experimentos controle em um campo aberto foram usados para confirmar a especificidade das alterações induzidas por cisplatina no desempenho em EI. Resultados: a administração de cisplatina levou a um inesperado aumento do desempenho de EI medido 7 dias após o treino. Os experimentos controle indicam que esse efeito não deve estar relacionado à toxicidade ou alterações em funções sensoriais e motoras. Discussão: os resultados são discutidos em relação a estudos prévios que indicam que, em algumas condições, quimioterápicos antineoplásicos podem levar a uma facilitação da memória