The main goal of this study is to alert researchers who work with cell cultures for the risk of contamination by structures called nanobacteria (NB). NB are tiny structures with size varying from 80 to 500 nm, commonly occurring in clusters and producing a biofilm which contains carbonate or hydroxyl apatite. The most likely source of cell culture contamination by such organisms is serum used as supplement in culture media. The presence of NB leads to a progressive culture deterioration with accumulation of granules (probably phagocytized NB) in cytoplasmic vacuoles, an increasing number of dead cells in the supernatant and degeneration of cells that remained attached to the bottom of the vessel. NB can also be found in culture supernatants where they are found in clusters with variable size and displaying brownian movement. In this study, 19 cell lineages, 8 batches of sera and 1 batch of growth supplement from different sources were analyzed. Samples from sera were cultured in Eagle's Minimum Essential Medium (E-MEM) or incubated directly at 37ºC. Tests carried out to detect the presence of extracellular bacteria, Mycoplasma sp and viruses were all negative. Analysis by scanning electron microscopy (SEM) revealed tiny oval structures less than 500 nm in size, isolated or in small groups, in all material analyzed except in one fetal bovine serum batch.
Calyptranthes tricona is a species (Myrtaceae) native to South Brazil. Plants belonging to this family are folkloric used for analgesia, inflammation, and infectious diseases. However, little is known about the toxic potential of C. tricona. The present study aimed to evaluate the antioxidant activity of C. tricona ethanol and hexane leaf extracts, as well as verify their effect on human lymphocytes and MCF-7 cells. The extracts were subjected to preliminary phytochemical screening, antioxidant activity using DPPH and ORAC methods. Genotoxic and mutagenic effects in cultured human lymphocytes were assessed using the comet assay and the micronucleus assay, respectively. In addition, cell viability by MTT assay and fluorometric analysis of mitochondrial potential and caspases-9 activity were performed in order to verify the possible effects of both extracts on HO-induced cell death of MCF-7 cells. Our findings revealed that the phenol content and the antioxidant activity were only present in the ethanol extract. Also, the phytochemical screening presented steroids, triterpenoids, condensed tannins, and flavones as the main compounds. However, both extracts were capable of inducing concentration-dependent DNA damage in human lymphocytes. When treating MCF-7 cells with the extracts, both of them inhibited MCF-7 cell death in response to oxidative stress through a decrease of mitochondrial depolarization and caspases-9 activity. Thus, our results need to be considered in future in vitro and in vivo studies of C. tricona effects. In the meanwhile, we recommend caution in the acute/chronic use of this homemade preparation for medicinal purpose.
Objectives: This study aimed to investigate the genetic infl uence of the T102C polymorphism of the 2A serotonin receptor gene (HTR2A) and its interaction with environmental aspects, such as exposure to noise, traffi c, climate, and opportunities to acquire new information, physical protection, and security, among others, as possible risk factors for developing fi bromyalgia syndrome (FMS). Methods: Forty-one FMS patients and 49 controls were evaluated. Environmental factors were evaluated by application of the V domain of the WHOQOL-100 questionnaire. Patients were asked that their answers represented only the periods preceding the onset of symptoms. The T102C variant of the HTR2A gene was determined through PCR/RFLP. Results: Among patients, the frequency of carriers of the 102C allele was higher than in controls (76.5% vs. 50%; P = 0.028). The scores of the V domain were lower in patients than in controls, indicating a worst perception of the environmental quality by patients (P < 0.001). The factor "lack of opportunities for acquiring new information and skills" increased the chance of developing FMS by almost 14-fold (P = 0.009). The factor "low quality of social care and health" together with the presence of the 102C allele also increased this chance by more than 90-fold (P = 0.005). However, carriers of the same allele who have high quality social care and health are not at a higher risk to develop FMS. Conclusion: These data suggest that these factors may predispose to FMS, especially in carriers of the 102C allele. However, studies with larger samples are required to confi rm this hypothesis.
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