High Concentrations of Cannabidiol Induce Neurotoxicity in Neurosphere Culture System.

Recent studies have demonstrated that cannabinoids are potentially effective in the treatment of various neurological conditions, and cannabidiol (CBD), one of the most studied compounds, has been proposed as a non-toxic option. However, the adverse effects of CBD on neurodevelopmental processes have rarely been studied in cell culture systems. To better understand CBD's influence on neurodevelopment, we exposed neural progenitor cells (NPCs) to different concentrations of CBD (1 µM, 5 µM, and 10 µM). We assessed the morphology, migration, differentiation, cell death, and gene expression in 2D and 3D bioprinted models to stimulate physiological conditions more effectively. Our results showed that CBD was more toxic at higher concentrations (5 µM and 10 µM) and affected the viability of NPCs than at lower concentrations (1 µM), in both 2D and 3D models. Moreover, our study revealed that higher concentrations of CBD drastically reduced the size of neurospheres and the number of NPCs within neurospheres, impaired the morphology and mobility of neurons and astrocytes after differentiation, and reduced neurite sprouting. Interestingly, we also found that CBD alters cellular metabolism by influencing the expression of glycolytic and ß-oxidative enzymes in the early and late stages of metabolic pathways. Therefore, our study demonstrated that higher concentrations of CBD promote important changes in cellular functions that are crucial during CNS development.

Seroprevalence to Rabies Virus in Wildlife in Brazil.

Serum samples of 638 free-ranging wild mammals from São Paulo state, Brazil, were tested for neutralizing antibodies against rabies virus by the rapid fluorescent focus inhibition test. Overall seroprevalence was 1.7% among 24 species surveyed, with individuals of six species having positive results indicating exposure to rabies virus.

Predictive factors of weaning from mechanical ventilation and extubation outcome: A systematic review.

PURPOSE: To identify, describe and discuss the parameters used to predict weaning from mechanical ventilation and extubation outcomes. METHODS: Systematic review of scientific articles using four electronic databases: PubMed, Embase, PEDro and Cochrane Library. Search terms included "weaning", "extubation", "withdrawal" and "discontinuation", combined with "mechanical ventilation" and "predictive factors", "predictive parameters" and "predictors for success". In this study, we included original articles that presented predictive factors for weaning or extubation outcomes in adult patients and not restricted to a single disease. Articles not written in English were excluded. RESULTS: A total of 43 articles were included, with a total of 7929 patients and 56 different parameters related to weaning and extubation outcomes. Rapid Shallow Breathing Index (RSBI) was the most common predictor, discussed in 15 studies (2159 patients), followed by Age and Maximum Inspiratory Pressure in seven studies. The other 53 parameters were found in less than six studies. CONCLUSION: There are several parameters used to predict weaning and extubation outcomes. RSBI was the most frequently studied and seems to be an important measurement tool in deciding whether to wean/extubate a patient. Furthermore, the results demonstrated that weaning and extubation should be guided by several parameters, and not only to respiratory ones.

Skipping of exon 27 in C3 gene compromises TED domain and results in complete human C3 deficiency.

Primary deficiency of complement C3 is rare and usually associated with increased susceptibility to bacterial infections. In this work, we investigated the molecular basis of complete C3 deficiency in a Brazilian 9-year old female patient with a family history of consanguinity. Hemolytic assays revealed complete lack of complement-mediated hemolytic activity in the patient's serum. While levels of the complement regulatory proteins Factor I, Factor H and Factor B were normal in the patient's and family members' sera, complement C3 levels were undetectable in the patient's serum and were reduced by at least 50% in the sera of the patient's parents and brother. Additionally, no C3 could be observed in the patient's plasma and cell culture supernatants by Western blot. We also observed that patient's skin fibroblasts stimulated with Escherichia coli LPS were unable to secrete C3, which might be accumulated within the cells before being intracellularly degraded. Sequencing analysis of the patient's C3 cDNA revealed a genetic mutation responsible for the complete skipping of exon 27, resulting in the loss of 99 nucleotides (3450-3549) located in the TED domain. Sequencing of the intronic region between the exons 26 and 27 of the C3 gene (nucleotides 6690313-6690961) showed a nucleotide exchange (T→C) at position 6690626 located in a splicing donor site, resulting in the complete skipping of exon 27 in the C3 mRNA.

Effects of centrifugation on cell composition and viability of aspirated adipose tissue processed for transplantation.

BACKGROUND: Centrifugation is one of the preferred methods of fat processing. Although it has been promoted for nearly three decades to separate adipose tissue components before grafting, there remain many controversies regarding the results obtained with centrifuged adipose tissue. OBJECTIVES: The authors demonstrate the effects of centrifugation on the cellular components of aspirated fat. METHODS: Fat harvested from the lower abdomen of 10 female patients undergoing liposuction was divided in two equal parts, then processed by decantation or centrifugation and sent to the laboratory. Each processed lipoaspirate was analyzed histologically after hematoxylin and periodic acid-Schiff staining for the presence of intact adipocytes. It was then cultured and analyzed by multicolor flow cytometry for identification of adipose-derived mesenchymal stem cells. RESULTS: The middle layer of the centrifuged lipoaspirate, which is used by many surgeons, showed a great majority of altered adipocytes and very few mesenchymal stem cells in comparison with the decanted sample, which maintained the integrity of the adipocytes and showed a greater number of mesenchymal stem cells. The pellet observed as a fourth layer at the bottom of the centrifuged lipoaspirate showed the greatest concentration of endothelial cells and mesenchymal stem cells, which play a crucial role in the angiogenic and adipogenic effect of the grafted tissue. CONCLUSIONS: If centrifuged lipoaspirate is used, the pellet (rich in adipose-derived mesenchymal stem cells) and the middle layer should be employed to increase fat graft survival.

Adipose tissue of control and ex-obese patients exhibit differences in blood vessel content and resident mesenchymal stem cell population.

BACKGROUND: The normal function of white adipose tissue is disturbed in obesity. After weight loss that follows bariatric surgery, ex-obese patients undergo plastic surgery to remove residual tissues and it is not known whether their adipose tissue returns to its original state. The aim of this study was to compare the white adipose tissue composition of ex-obese with control patients with regard to blood vessels and resident mesenchymal stem cells (MSC). METHODS: Quantification of blood vessels was performed on histological sections of adipose tissue stained with hematoxylin and eosin and for von Willebrand antigen. MSC were induced to the adipogenic and osteogenic lineages by specific inductive culture media. Expression of PPARgamma2 was analyzed by reverse transcription polymerase chain reaction. RESULTS: Ex-obese adipose tissue showed a higher number (p = 0.0286) of small (107.3 +/- 22.0) and large (22.5 +/- 6.4) blood vessels, when compared to control patients (42.0 +/- 24.4 and 7.2 +/- 2.2, respectively) and they also occupied a larger area (control versus ex-obese, p = 0.0286). Adipose tissue MSC from both groups of patients expressed PPARgamma2 and were equally able to differentiate to the osteogenic lineage, but ex-obese MSC showed a higher adipogenic potential when induced in vitro (p < 0.05). CONCLUSIONS: The higher number of adipose tissue blood vessels in ex-obese patients explains the excessive bleeding observed during their plastic surgery. The presence of more committed cells to the adipogenic lineage may favor the easy weight regain that occurs in ex-obese patients. These results show that, after extensive weight loss, adipose tissue cell composition was not totally restored.