Raquel Montenegro | Universidade Federal do Pará (original) (raw)

Papers by Raquel Montenegro

Frontiers in Pharmacology

Chronic myeloid leukemia (CML) is caused by constitutively active fusion protein BCR-ABL1, and ta... more Chronic myeloid leukemia (CML) is caused by constitutively active fusion protein BCR-ABL1, and targeting ABL1 is a promising therapy option. Imatinib, dasatinib, and nilotinib have all been shown to work effectively in clinical trials. ABL1 mutations, particularly the T315I gate-keeper mutation, cause resistance in patients. As a result, broad-spectrum ABL1 medicines are desperately needed. In order to screen potential drugs targeting CML, mebendazole (MBZ) was subjected to the in vitro test against CML cell lines (K562 and FEPS) and computational assays. The antiproliferative effect of MBZ and the combination with tyrosine kinase inhibitors (TKIs) was tested using end-point viability assays, cell cycle distribution analysis, cell membrane, and mitochondrial dyes. By interrupting the cell cycle and causing cell death, MBZ and its combination with imatinib and dasatinib have a significant antiproliferative effect. We identified MBZ as a promising “new use” drug targeting wild-type an...

International Journal of Molecular Sciences

The multidrug resistance (MDR) phenotype is one of the major obstacles in the treatment of chroni... more The multidrug resistance (MDR) phenotype is one of the major obstacles in the treatment of chronic myeloid leukemia (CML) in advantage stages such as blast crisis. In this scenario, more patients develop resistance mechanisms during the course of the disease, making tyrosine kinase inhibitors (TKIs) target therapies ineffective. Therefore, the aim of the study was to examine the pharmacological role of CNN1, a para-naphthoquinone, in a leukemia multidrug resistant cell line. First, the in vitro cytotoxic activity of Imatinib Mesylate (IM) in K-562 and FEPS cell lines was evaluated. Subsequently, membrane integrity and mitochondrial membrane potential assays were performed to assess the cytotoxic effects of CNN1 in K-562 and FEPS cell lines, followed by cell cycle, alkaline comet assay and annexin V-Alexa Fluor® 488/propidium iodide assays (Annexin/PI) using flow cytometry. RT-qPCR was used to evaluate the H2AFX gene expression. The results demonstrate that CNN1 was able to induce ap...

Brazilian Journal of Case Reports

Chronic Myeloid Leukemia (CML) is characterized by the increased and unregulated growth of myeloi... more Chronic Myeloid Leukemia (CML) is characterized by the increased and unregulated growth of myeloid cells in bone marrow and accumulation of these cells in blood. Its occurrence during pregnancy is a very rare condition and the correct management is not well stablished yet. We present a case of a 21-year-old female diagnosed with CML during pregnancy. The protocol chose by the doctor was hydroxyurea on second trimester, and interferon-alpha on third trimester. The baby was born healthy and at the expected time. After giving birth, the patient started Imatinib Mesilate (IM) 400mg/day treatment and was able to control the disease.

Journal of Ethnopharmacology, 2021

Ethnopharmacological relevance: 22β-hydroxytingenone (22-HTG) is a quinonemethide triterpene isol... more Ethnopharmacological relevance: 22β-hydroxytingenone (22-HTG) is a quinonemethide triterpene isolated from Salacia impressifolia (Miers) A. C. Smith (family Celastraceae), which has been used in traditional medicine to treat a variety of diseases, including dengue, renal infections, rheumatism and cancer. However, the anticancer effects of 22-HTG and the underlying molecular mechanisms in melanoma cells have not yet been elucidated. Aim of the study: The present study investigated apoptosis induction and antimetastatic potencial of 22-HTG in SK-MEL-28 human melanoma cells. Materials and methods: First, the in vitro cytotoxic activity of 22-HTG in cultured cancer cells was evaluated. Then, cell viability was determined using the trypan blue assay in melanoma cells (SK-MEL-28), which was followed by cell cycle, annexin V-FITC/propidium iodide assays (Annexin/PI), as well as assays to evaluate mitochondrial membrane potential, production of reactive oxygen species (ROS) using flow cytometry. Fluorescence microscopy using acridine orange/ethidium bromide (AO/BE) staining was also performed. RT-qPCR was carried out to evaluate the expression of BRAF, NRAS, and KRAS genes. The anti-invasiveness potential of 22-HTG was evaluated in a three-dimensional (3D) model of reconstructed human skin. Results: 22-HTG reduced viability of SK-MEL-28 cells and caused morphological changes, as cell shrinkage, chromatin condensation, and nuclear fragmentation. Furthermore, 22-HTG caused apoptosis, which was demonstrated by increased staining with AO/BE and Annexin/PI. The apoptosis may have been caused by mitochondrial instability without the involvement of ROS production. The expression of BRAF, NRAS, and KRAS, which are important biomarkers in melanoma development, was reduced by the 22-HTG treatment. In the reconstructed skin model, 22-HTG was able to decrease the invasion capacity of melanoma cells in the dermis.

PLOS ONE, 2015

Millions of blood products are transfused each year, and many lives are directly affected by tran... more Millions of blood products are transfused each year, and many lives are directly affected by transfusion. Platelet concentrate (PC) is one of the main products derived from blood. Even under good storage conditions, PC is likely to suffer cell damage. The shape of platelets changes after 5 to 7 days of storage at 22°C. Taking into consideration that some platelet proteins undergo changes in their shape and functionality during PC storage. Sixteen PC bags were collected and each PC bag tube was cut into six equal pieces to perform experiments with platelets from six different days of storage. Thus, on the first day of storage, 1/6 of the tube was used for miRNA extraction, and the remaining 5/6 was stored under the same conditions until extraction of miRNAs on each the following five days. Samples were sequenced on an Illumina Platform to demonstrate the most highly expressed miRNAs. Three miRNAs, mir127, mir191 and mir320a were validated by real-time quantitative PCR (RQ-PCR) in 100 PC bags tubes. Our method suggests, the use of the miRNAs mir127 and mir320a as biomarkers to assess the "validity period" of PC bags stored in blood banks for long periods. Thus, bags can be tested on the 5th day of storage for the relative expression levels of mir127 and mir320a. Thus, we highlight candidate miRNAs as biomarkers of storage damage that can be used as tools to evaluate the quality of stored PC. The use of miR-NAs as biomarkers of damage is unprecedented and will contribute to improved quality of blood products for transfusions.

In vivo (Athens, Greece)

The immune response modifier Canova® is a homeopathic remedy indicated for patients with depresse... more The immune response modifier Canova® is a homeopathic remedy indicated for patients with depressed immune system, since this drug appears to increase adaptive immunity and induce an immune response against multiple and severe pathological conditions, including cancer. We evaluated the pattern of immune cellular response in non-human primates of the species Cebus apella exposed to N-methyl-N-nitrosourea (MNU) with and without Canova®. Twelve animals were divided into four groups, with three animals each: negative control and three experimental groups, MNU-alone (35 days); MNU (35 days)-plus-Canova® (3 days) and Canova®-alone (3 days). The animals received MNU orally and Canova® by three intravenous injections. Evaluation of the cellular immune response was performed by immunophenotyping of T-lymphocytes (CD4(+), CD8(+)), B-lymphocytes and natural killer cells. Analysis was also performed of the cell cycle. Our results suggest an increase of T-lymphocytes (CD4(+)CD3(+)) only in the Ca...

PLoS ONE, 2013

Our study investigated the relationship between MYC alterations and clinicopathological features ... more Our study investigated the relationship between MYC alterations and clinicopathological features in gastric cancers. We evaluated the effect of MYC mRNA expression and its protein immunoreactivity, as well as copy number variation, promoter DNA methylation, and point mutations, in 125 gastric adenocarcinoma and 67 paried non-neoplastic tissues. We observed that 77% of the tumors presented MYC immunoreactivity which was significantly associated with increased mRNA expression (p,0.05). These observations were associated with deeper tumor extension and the presence of metastasis (p,0.05). MYC protein expression was also more frequently observed in intestinal-type than in diffuse-type tumors (p,0.001). Additionally, MYC mRNA and protein expression were significantly associated with its copy number (p,0.05). The gain of MYC copies was associated with late-onset, intestinal-type, advanced tumor stage, and the presence of distant metastasis (p,0.05). A hypomethylated MYC promoter was detected in 86.4% of tumor samples. MYC hypomethylation was associated with diffuse-type, advanced tumor stage, deeper tumor extension, and the presence of lymph node metastasis (p,0.05). Moreover, eighteen tumor samples presented at least one known mutation. The presence of MYC mutations was associated with diffuse-type tumor (p,0.001). Our results showed that MYC deregulation was mainly associated with poor prognostic features and also reinforced the presence of different pathways involved in intestinal-type and diffuse-type gastric carcinogenesis. Thus, our findings suggest that MYC may be a useful marker for clinical stratification and prognosis.

Alzheimer's Disease Pathogenesis-Core Concepts, Shifting Paradigms and Therapeutic Targets, 2011

Alzheimer's Disease Pathogenesis-Core Concepts, Shifting Paradigms and Therapeutic Targets 404 de... more Alzheimer's Disease Pathogenesis-Core Concepts, Shifting Paradigms and Therapeutic Targets 404 demonstrated that brain Al content increases with age and that Al generates reactive oxygen species (ROS) that activates signaling pathways which leads to degeneration of neuronal cells. Together with ROS or alone, Al is biochemically attracted to the DNA reveling its genotoxic and mutagenic potential. Furthermore, high level of Al has been found in brain lesions, such as plaques and tangles, in patients with AD. Several studies demonstrated that among others, Al appears to be the most efficient cation in promoting Aβ aggregation, increasing dramatically cellular neurotoxicity. According to the "amyloid cascade hypothesis", accumulation of Aβ in the brain is the primary event driving AD pathogenesis, increasing the evidences by which Al is involved in AD. Iron is an essential trace element used by almost all living organisms, being often incorporated into the heme complex, which mediate redox reactions. Disturbances of brain iron homeostasis have been linked to acute neuronal injury. Moreover, iron is toxic to neural tissue, leading to neurodegenerative disorders. Organic iron (Fe) may increase the genotoxic effects of other compounds when they are combined. Together with aluminum sulfate, at nanomolar concentrations, iron trigger the release of reactive oxygen species (ROS). In high levels, iron can be mutagenic and genotoxic. In AD, iron is an important cause of oxidative stress because of its overaccumulation in the brain and colocalizes with AD lesions, senile plaques and neurofibrillary tangles. Recent studies also show that homeostasis of essential metals such as copper, iron, selenium and zinc may be altered in the brain of subjects with Alzheimer's disease. It is demonstrated that the plasma concentrations of manganese and total mercury were significantly higher in subjects with AD than in controls, however the concentrations of vanadium, manganese, rubidium, antimony, cesium and lead were significantly lower among subjects with AD cerebrospinal fluid. The influence of metal ions such as Fe, Cu, and Zn in stimulating Aβ aggregation have been widely studied where they appears to vary depending on tissue pH. It should be noticed that, although there is co-localization of metal ions in the pathological markers of AD, this does not indicate a causative role for these elements in the pathogenesis of the disease. Independently of metals being a primary cause or consequence of the disease mechanism, a change in a single metal ion can cause a significant imbalance on homeostasis in elemental levels in the body (serum, CSF and brain) leading to as a sort of "domino effect". It is clear the need to understand the fundamental biochemical mechanisms linking brain biometal metabolism, environmental metal exposure, genotoxicity and AD pathophysiology. In this review, we discuss the role of metals in Alzheimer disease and its involvement in genotoxicity. 2. Source of metal exposure Metals have been used throughout human history to make several utensils, machines, jewelry, and so on, where many of then were obtained through mining and smelting, activities that increases their distribution throughout the environment. Furthermore, the use of metals in industry, medicine, agriculture have been increased over the years, which increase the exposure, not only for those workers involved directly in working with metals but also consumers of the products and the general public through environmental contamination (Ferrer, 2003; Ansari et al., 2004).

Toxicology in Vitro, 2008

Iron (Fe) is a common chemical element that is essential for organisms as a co-factor in oxygen t... more Iron (Fe) is a common chemical element that is essential for organisms as a co-factor in oxygen transport, but that in high amounts presents a significant risk of neurodegenerative disorders. The objective of this study was to evaluate the mutagenic potential of iron sulfate. The comet assay and chromosome aberration (CA) analysis were applied to determine the DNA-damaging and clastogenic effects of iron sulfate. Human lymphocytes were treated in the quiescent phase for the comet assay and proliferative phase during the G 1 , G 1 /S, S (pulses of 1 and 6 h), and G 2 phases of the cell cycle for CA analysis, with 1.25, 2.5 and 5 lg/mL concentrations of FeSO 4 Á 7H 2 O. All tested concentrations were cytotoxic and reduced significantly the mitotic index (MI) in all phases of the cell cycle. They also induced CA in G 1 , G 1 /S and S (pulses of 1 and 6 h) phases. Iron sulfate also induced polyploidy in cells treated during G 1. In the comet assay, this metal did not induce significant DNA damage. Our results show that Fe causes alteration and inhibition of DNA synthesis only in proliferative cells, which explain the concomitant occurrence of mutagenicity and cytotoxicity, respectively, in the lymphocytes studied.

Toxicology in Vitro, 2008

Manganese (Mn) has a natural occurrence and is necessary during the initial periods of the develo... more Manganese (Mn) has a natural occurrence and is necessary during the initial periods of the development. However, in high concentrations, Mn can be related to neurodegenerative disorders. The aim of the present study was to evaluate the mutagenic potential of manganese chloride (MnCl 2 Á 4H 2 O). Comet assay and chromosome aberrations analysis were applied to determine the DNA-damaging and clastogenic effects of MnCl 2 Á 4H 2 O. Cultured human lymphocytes were treated with 15, 20 and 25 lM manganese chloride during the G1, G1/S, S (pulses of 1 and 6 h), and G2 phases of the cell cycle. All tested concentrations were cytotoxic and reduced significantly the mitotic index in G1, G1/S and S (1 and 6 h) treatments, while in G2 treatment only the higher concentrations (20 and 25 lM) showed cytotoxic effects. Clastogenicity and DNA damage were found only in treatments with the highest concentration (25 lM). Chromosome aberrations were found exclusively in the G2 phase of the cell cycle. The absence of polyploidy in mitosis, suggests that manganese does not affect the formation of the mitotic spindle with the concentrations tested. The genotoxicity found in G2 phase and in the comet assay can be related to the short time of treatment in both cases.

Toxicology in Vitro, 2013

The down-regulation or loss of epithelial markers is often accompanied by the up-regulation of me... more The down-regulation or loss of epithelial markers is often accompanied by the up-regulation of mesenchymal markers. E-cadherin generally suppresses invasiveness, whereas N-cadherin promotes invasion and metastasis in vitro. The aim of this work is to investigate the role of biflorin, a naphthoquinone with proven anticancer properties, on the expression of N-cadherin and AKT proteins in MDA-MB-435 invasive melanoma cancer cells after 12 h of exposure to 1, 2.5 and 5 lM biflorin. Biflorin inhibited MDA-MB-435 invasion in a dose-dependent manner (p < 0.01). Likewise, biflorin down-regulated N-cadherin and AKT-1 expression in a dose-dependent manner. Biflorin did not inhibit the adhesion of MDA-MB-435 cells to any tested substrates. Additionally, biflorin blocked the invasiveness of cells by down-regulating N-cadherin, most likely via AKT-1 signaling. As such, biflorin may be a novel anticancer agent and a new prototype for drug design.

Journal of Applied Toxicology, 2010

Despite the remarkable progress in the characterization of the molecular pathogenesis of glioblas... more Despite the remarkable progress in the characterization of the molecular pathogenesis of glioblastoma multiforme (GBM), these tumors remain incurable and, in most cases, refractory to aggressive cytotoxic treatments. We conducted a morphological and cytogenetic study in two GBM cell lines (U343 and AHOL1), before and after treatment with pisosterol (at 0.5, 1.0 and 1.8 mg ml-1), a triterpene isolated from the fungus Pisolithus tinctorius. No significant alteration was observed in the morphology and frequency of chromosomal abnormalities in the cell lines analyzed after treatment with pisosterol. Using fluorescence in situ hybridization analysis with a locus-specific probe for C-MYC showed that 72% of U343 and 65% of AHOL1 cells contained more than two alleles of C-MYC before treatment. After treatment, no effects were detected at lower concentrations of pisosterol (0.5 and 1.0 mg ml-1). However, at 1.8 mg ml-1 of pisosterol, only 33% of U343 cells and 15% of AHOL1 cells presented more than two fluorescent signals, suggesting that pisosterol blocks the cells with gene amplification. Cells that do not show a high degree of C-MYC gene amplification have a less aggressive and invasive behavior and are easy targets for chemotherapy. Therefore, further studies are needed to examine the use of pisosterol in combination with conventional anti-cancer therapy.

International Journal of Cardiology, 2014

Background: Oral bacteria have been detected in atherosclerotic plaques at a variable frequency; ... more Background: Oral bacteria have been detected in atherosclerotic plaques at a variable frequency; however, the connection between oral health and vascular and oral bacterial profiles of patients with vascular disease is not clearly established. The aim of this study was to evaluate the presence of oral bacterial DNA in the mouth and atherosclerotic plaques, in addition to assessing the patients' caries and periodontal disease history. Methods: Thirty samples of supragingival and subgingival plaque, saliva and atherosclerotic plaques of 13 patients with carotid stenosis or aortic aneurysm were evaluated, through real-time polymerase chain reaction, for the presence of Streptococcus mutans (SM), Prevotella intermedia (PI), Porphyromonas gingivalis (PG) and Treponema denticola (TD). All patients were submitted to oral examination using the DMFT (decayed, missing and filled teeth) and PSR (Periodontal Screening and Recording) indexes. Histopathological analysis of the atherosclerotic plaques was performed. Results: Most of the patients were edentulous (76.9%). SM, PI, PG and TD were detected in 100.0%, 92.0%, 15.3% and 30.7% of the oral samples, respectively. SM was the most prevalent targeted bacteria in atherosclerotic plaques, detected in 100% of the samples, followed by PI (7.1%). The vascular samples were negative for PG and TD. There was a statistically significant difference (p b 0.05) between the presence of PG and TD in the oral cavity and vascular samples. Conclusion: SM was found at a high frequency in oral and vascular samples, even in edentulous patients, and its presence in atherosclerotic plaques suggests the possible involvement of this bacterium in the disease progression.

Industrial Crops and Products, 2014

The hydrodistilled oils of Piper hispidum, Piper aleyreanum, and Piper anonifolium, collected in ... more The hydrodistilled oils of Piper hispidum, Piper aleyreanum, and Piper anonifolium, collected in the Carajás National Forest, Pará state, Brazil, were analyzed by GC and GC-MS and then, evaluated their antioxidant, antifungal, anticholinesterase and cytotoxic activities. In total, 87 constituents were identified in the Piper oils. The sesquiterpenes were the most highly represented classes and the main compounds found in the Piper oils were selin-11-en-4-␣-ol, ␤-elemene, ␤-selinene, ␣-selinene, bicyclogermacrene, ␤-caryophyllene, ␣-humulene, and ␦-elemene. All analyzed oils showed powerful antifungal activity, with the detection limit (DL) from 0.1 to 1.0 g against the Cladosporium cladosporioides and Cladosporium sphareospermum fungi, as well they have no lytic effect against the mice erythrocytes. In the anticholinesterase evaluation, the oils of P. anonifolium (DL = 0.01 ng) and P. hispidum (DL = 0.01 ng) were hundred times more potent than the standard physostigmine (DL = 1.0 ng). Moreover, the oil of P. aleyreanum showed high in vitro cytotoxic activity against the human melanoma cell line SKMEL-19 (IC 50 = 7.4 g/mL) and significant antioxidant activity (DPPH = 412.2 mg TE/mL). The higher cell growth inhibition induced by the oil of P. aleyreanum is probably due to elemene (␤-, ␦-, and ␥-elemene), as well as other structurally related compounds, which were previously reported in the proliferation inhibition, stimulation of apoptosis and induction of cell cycle arrest in malignant cells.

Cell cycle arrest induced by Pisosterol in HL60 cells with gene amplification

Cell Biology and Toxicology, 2008

The leukemia cell line HL60 is widely used in studies of the cell cycle, apoptosis, and adhesion ... more The leukemia cell line HL60 is widely used in studies of the cell cycle, apoptosis, and adhesion mechanisms in cancer cells. We conducted a focused cytogenetic study in an HL60 cell line, by analyzing GTG-banded chromosomes before and after treatment with pisosterol (at 0.5, 1.0, and 1.8 microg/ml), a triterpene isolated from Pisolithus tinctorius, a fungus collected in the Northeast of Brazil. Before treatment, 99% of the cells showed the homogeneously staining region (HSR) 8q24 aberration. After treatment with 1.8 microg/ml pisosterol, 90% of the analyzed cells lacked this aberration. We further performed a pulse test, in which the cells treated with pisosterol (0.5, 1.0, and 1.8 microg/ml) were washed and re-incubated in the absence of pisosterol. Only 30% of the analyzed cells lacked the HSR 8q24 aberration, suggesting that pisosterol probably blocks the cells with HSRs at interphase. No effects were detected at lower concentrations. At the highest concentration examined (1.8 microg/ml), pisosterol also inhibited cell growth, but this effect was not observed in the pulse test, reinforcing our hypothesis that, at the concentrations tested, pisosterol probably does not induce cell death in the HL60 line. The results found for pisosterol were compared with those for doxorubicin. Cells that do not show a high degree of gene amplification (HSRs and double-minute chromosomes) have a less aggressive and invasive behavior and are easy targets for chemotherapy. Therefore, further studies are needed to examine the use of pisosterol in combination with conventional anti-cancer therapy.

BMC Gastroenterology, 2012

Background Gastric cancer is a serious public health problem in Northern Brazil and in the world ... more Background Gastric cancer is a serious public health problem in Northern Brazil and in the world due to its high incidence and mortality. Despite the severity of the disease, more research is needed to better understand the molecular events involved in this intestinal-type gastric carcinogenesis process. Since precancerous lesions precede intestinal-type gastric cancer, here, we evaluated the hTERT, MYC, and TP53 mRNA and protein expression, as well as TP33 copy number, in gastric preneoplastic lesions. Methods We evaluated 19 superficial gastritis, 18 atrophic gastritis, and 18 intestinal metaplasia from cancer-free individuals of Northern Brazil. Quantitative reverse transcription PCR was used to analyze the mRNA expression and immunohistochemical methods were used to assess protein immunoreactivity in tissue samples. The number of TP53 gene copies was investigated in gastric diseases by quantitative PCR. Results We observed hTERT, MYC, and p53 immunoreactivity only in intestinal ...

Molecules, 2014

As part of a continuing search for new potential anticancer candidates, we describe the synthesis... more As part of a continuing search for new potential anticancer candidates, we describe the synthesis, cytotoxicity and mechanistic evaluation of a series of 4-oxoquinoline-3-carboxamide derivatives as novel anticancer agents. The inhibitory activity of compounds 10-18 was determined against three cancer cell lines using the MTT colorimetric assay. The screening revealed that derivatives 16b and 17b exhibited significant cytotoxic activity against the gastric cancer cell line but was not active against a normal cell line, in contrast to doxorubicin, a standard chemotherapeutic drug in clinical use. Interestingly, no hemolytical activity was observed when the toxicity of 16b and 17b was tested against blood cells. The in silico and in vitro mechanistic evaluation indicated

Pisosterol induces interphase arrest in HL60 cells with C-MYC amplification

Human & Experimental Toxicology, 2010

The leukaemia cell line HL60 is widely used in studies of the cell cycle, apoptosis and adhesion ... more The leukaemia cell line HL60 is widely used in studies of the cell cycle, apoptosis and adhesion mechanisms in cancer cells. One marked characteristic of HL60 cells is the C-MYC proto-oncogene amplification, resulting in the formation of homogeneously staining regions (HSRs) at 8p24. We conducted a fluorescence in situ hybridization study in an HL60 cell line, using a locus-specific probe for C-MYC, before and after treatment with pisosterol (at 0.5, 1.0 and 1.8 μg/mL), a triterpene isolated from the fungus Pisolithus tinctorius. Before treatment, 87.5% of the cells showed HSRs. After treatment, no effects were detected at lower concentrations of pisosterol (0.5 and 1.0 μg/mL). However, at 1.8 μg/mL only 15% of the cells presented HSRs, and 39.5% presented few fluorescent signals (3 or 4 alleles), suggesting that pisosterol probably blocks the cells with HSRs at interphase. This result is particularly interesting because cells that do not show a high degree of C-MYC gene amplificati...

Additional file 1: of mtDNA structure: the women who formed the Brazilian Northeast

Mitochondrial DNA ancestral group frequencies in other Brazilian geopolitical regions. (DOCX 30 kb)

Dementia & Neuropsychologia, 2021

Background: COVID-19 neurological manifestations were demonstrated during the pandemic, including... more Background: COVID-19 neurological manifestations were demonstrated during the pandemic, including cognitive impairment. Objectives: To determine the prevalence of cognitive and behavioral complaints (such as dementia, MCI or SCD) in a outpatient sample with recent SARS-COV2 infection. Specific: Evaluate the association of cognitive impairment with the presence of the polymorphism found in the APOE gene and with respiratory disease. Methodology: Observational, longitudinal, prospective clinical study. Inclusion criteria: patients with confirmed Covid-19. Patients are evaluated in an outpatient clinic. They are evaluated through a standardized attendance record, with somatic and cognitive neurological assessment. Cognitive assessment involves the application of cognitive (ACER, MMSE and CDR), functional (Pfeffer) and psychiatric (GDS or Beck) screening instruments, in addition to subsequent extensive neuropsychological assessment. In addition, APOE polymorphism is analysed. Preliminar...

Frontiers in Pharmacology

Chronic myeloid leukemia (CML) is caused by constitutively active fusion protein BCR-ABL1, and ta... more Chronic myeloid leukemia (CML) is caused by constitutively active fusion protein BCR-ABL1, and targeting ABL1 is a promising therapy option. Imatinib, dasatinib, and nilotinib have all been shown to work effectively in clinical trials. ABL1 mutations, particularly the T315I gate-keeper mutation, cause resistance in patients. As a result, broad-spectrum ABL1 medicines are desperately needed. In order to screen potential drugs targeting CML, mebendazole (MBZ) was subjected to the in vitro test against CML cell lines (K562 and FEPS) and computational assays. The antiproliferative effect of MBZ and the combination with tyrosine kinase inhibitors (TKIs) was tested using end-point viability assays, cell cycle distribution analysis, cell membrane, and mitochondrial dyes. By interrupting the cell cycle and causing cell death, MBZ and its combination with imatinib and dasatinib have a significant antiproliferative effect. We identified MBZ as a promising “new use” drug targeting wild-type an...

International Journal of Molecular Sciences

The multidrug resistance (MDR) phenotype is one of the major obstacles in the treatment of chroni... more The multidrug resistance (MDR) phenotype is one of the major obstacles in the treatment of chronic myeloid leukemia (CML) in advantage stages such as blast crisis. In this scenario, more patients develop resistance mechanisms during the course of the disease, making tyrosine kinase inhibitors (TKIs) target therapies ineffective. Therefore, the aim of the study was to examine the pharmacological role of CNN1, a para-naphthoquinone, in a leukemia multidrug resistant cell line. First, the in vitro cytotoxic activity of Imatinib Mesylate (IM) in K-562 and FEPS cell lines was evaluated. Subsequently, membrane integrity and mitochondrial membrane potential assays were performed to assess the cytotoxic effects of CNN1 in K-562 and FEPS cell lines, followed by cell cycle, alkaline comet assay and annexin V-Alexa Fluor® 488/propidium iodide assays (Annexin/PI) using flow cytometry. RT-qPCR was used to evaluate the H2AFX gene expression. The results demonstrate that CNN1 was able to induce ap...

Brazilian Journal of Case Reports

Chronic Myeloid Leukemia (CML) is characterized by the increased and unregulated growth of myeloi... more Chronic Myeloid Leukemia (CML) is characterized by the increased and unregulated growth of myeloid cells in bone marrow and accumulation of these cells in blood. Its occurrence during pregnancy is a very rare condition and the correct management is not well stablished yet. We present a case of a 21-year-old female diagnosed with CML during pregnancy. The protocol chose by the doctor was hydroxyurea on second trimester, and interferon-alpha on third trimester. The baby was born healthy and at the expected time. After giving birth, the patient started Imatinib Mesilate (IM) 400mg/day treatment and was able to control the disease.

Journal of Ethnopharmacology, 2021

Ethnopharmacological relevance: 22β-hydroxytingenone (22-HTG) is a quinonemethide triterpene isol... more Ethnopharmacological relevance: 22β-hydroxytingenone (22-HTG) is a quinonemethide triterpene isolated from Salacia impressifolia (Miers) A. C. Smith (family Celastraceae), which has been used in traditional medicine to treat a variety of diseases, including dengue, renal infections, rheumatism and cancer. However, the anticancer effects of 22-HTG and the underlying molecular mechanisms in melanoma cells have not yet been elucidated. Aim of the study: The present study investigated apoptosis induction and antimetastatic potencial of 22-HTG in SK-MEL-28 human melanoma cells. Materials and methods: First, the in vitro cytotoxic activity of 22-HTG in cultured cancer cells was evaluated. Then, cell viability was determined using the trypan blue assay in melanoma cells (SK-MEL-28), which was followed by cell cycle, annexin V-FITC/propidium iodide assays (Annexin/PI), as well as assays to evaluate mitochondrial membrane potential, production of reactive oxygen species (ROS) using flow cytometry. Fluorescence microscopy using acridine orange/ethidium bromide (AO/BE) staining was also performed. RT-qPCR was carried out to evaluate the expression of BRAF, NRAS, and KRAS genes. The anti-invasiveness potential of 22-HTG was evaluated in a three-dimensional (3D) model of reconstructed human skin. Results: 22-HTG reduced viability of SK-MEL-28 cells and caused morphological changes, as cell shrinkage, chromatin condensation, and nuclear fragmentation. Furthermore, 22-HTG caused apoptosis, which was demonstrated by increased staining with AO/BE and Annexin/PI. The apoptosis may have been caused by mitochondrial instability without the involvement of ROS production. The expression of BRAF, NRAS, and KRAS, which are important biomarkers in melanoma development, was reduced by the 22-HTG treatment. In the reconstructed skin model, 22-HTG was able to decrease the invasion capacity of melanoma cells in the dermis.

PLOS ONE, 2015

Millions of blood products are transfused each year, and many lives are directly affected by tran... more Millions of blood products are transfused each year, and many lives are directly affected by transfusion. Platelet concentrate (PC) is one of the main products derived from blood. Even under good storage conditions, PC is likely to suffer cell damage. The shape of platelets changes after 5 to 7 days of storage at 22°C. Taking into consideration that some platelet proteins undergo changes in their shape and functionality during PC storage. Sixteen PC bags were collected and each PC bag tube was cut into six equal pieces to perform experiments with platelets from six different days of storage. Thus, on the first day of storage, 1/6 of the tube was used for miRNA extraction, and the remaining 5/6 was stored under the same conditions until extraction of miRNAs on each the following five days. Samples were sequenced on an Illumina Platform to demonstrate the most highly expressed miRNAs. Three miRNAs, mir127, mir191 and mir320a were validated by real-time quantitative PCR (RQ-PCR) in 100 PC bags tubes. Our method suggests, the use of the miRNAs mir127 and mir320a as biomarkers to assess the "validity period" of PC bags stored in blood banks for long periods. Thus, bags can be tested on the 5th day of storage for the relative expression levels of mir127 and mir320a. Thus, we highlight candidate miRNAs as biomarkers of storage damage that can be used as tools to evaluate the quality of stored PC. The use of miR-NAs as biomarkers of damage is unprecedented and will contribute to improved quality of blood products for transfusions.

In vivo (Athens, Greece)

The immune response modifier Canova® is a homeopathic remedy indicated for patients with depresse... more The immune response modifier Canova® is a homeopathic remedy indicated for patients with depressed immune system, since this drug appears to increase adaptive immunity and induce an immune response against multiple and severe pathological conditions, including cancer. We evaluated the pattern of immune cellular response in non-human primates of the species Cebus apella exposed to N-methyl-N-nitrosourea (MNU) with and without Canova®. Twelve animals were divided into four groups, with three animals each: negative control and three experimental groups, MNU-alone (35 days); MNU (35 days)-plus-Canova® (3 days) and Canova®-alone (3 days). The animals received MNU orally and Canova® by three intravenous injections. Evaluation of the cellular immune response was performed by immunophenotyping of T-lymphocytes (CD4(+), CD8(+)), B-lymphocytes and natural killer cells. Analysis was also performed of the cell cycle. Our results suggest an increase of T-lymphocytes (CD4(+)CD3(+)) only in the Ca...

PLoS ONE, 2013

Our study investigated the relationship between MYC alterations and clinicopathological features ... more Our study investigated the relationship between MYC alterations and clinicopathological features in gastric cancers. We evaluated the effect of MYC mRNA expression and its protein immunoreactivity, as well as copy number variation, promoter DNA methylation, and point mutations, in 125 gastric adenocarcinoma and 67 paried non-neoplastic tissues. We observed that 77% of the tumors presented MYC immunoreactivity which was significantly associated with increased mRNA expression (p,0.05). These observations were associated with deeper tumor extension and the presence of metastasis (p,0.05). MYC protein expression was also more frequently observed in intestinal-type than in diffuse-type tumors (p,0.001). Additionally, MYC mRNA and protein expression were significantly associated with its copy number (p,0.05). The gain of MYC copies was associated with late-onset, intestinal-type, advanced tumor stage, and the presence of distant metastasis (p,0.05). A hypomethylated MYC promoter was detected in 86.4% of tumor samples. MYC hypomethylation was associated with diffuse-type, advanced tumor stage, deeper tumor extension, and the presence of lymph node metastasis (p,0.05). Moreover, eighteen tumor samples presented at least one known mutation. The presence of MYC mutations was associated with diffuse-type tumor (p,0.001). Our results showed that MYC deregulation was mainly associated with poor prognostic features and also reinforced the presence of different pathways involved in intestinal-type and diffuse-type gastric carcinogenesis. Thus, our findings suggest that MYC may be a useful marker for clinical stratification and prognosis.

Alzheimer's Disease Pathogenesis-Core Concepts, Shifting Paradigms and Therapeutic Targets, 2011

Alzheimer's Disease Pathogenesis-Core Concepts, Shifting Paradigms and Therapeutic Targets 404 de... more Alzheimer's Disease Pathogenesis-Core Concepts, Shifting Paradigms and Therapeutic Targets 404 demonstrated that brain Al content increases with age and that Al generates reactive oxygen species (ROS) that activates signaling pathways which leads to degeneration of neuronal cells. Together with ROS or alone, Al is biochemically attracted to the DNA reveling its genotoxic and mutagenic potential. Furthermore, high level of Al has been found in brain lesions, such as plaques and tangles, in patients with AD. Several studies demonstrated that among others, Al appears to be the most efficient cation in promoting Aβ aggregation, increasing dramatically cellular neurotoxicity. According to the "amyloid cascade hypothesis", accumulation of Aβ in the brain is the primary event driving AD pathogenesis, increasing the evidences by which Al is involved in AD. Iron is an essential trace element used by almost all living organisms, being often incorporated into the heme complex, which mediate redox reactions. Disturbances of brain iron homeostasis have been linked to acute neuronal injury. Moreover, iron is toxic to neural tissue, leading to neurodegenerative disorders. Organic iron (Fe) may increase the genotoxic effects of other compounds when they are combined. Together with aluminum sulfate, at nanomolar concentrations, iron trigger the release of reactive oxygen species (ROS). In high levels, iron can be mutagenic and genotoxic. In AD, iron is an important cause of oxidative stress because of its overaccumulation in the brain and colocalizes with AD lesions, senile plaques and neurofibrillary tangles. Recent studies also show that homeostasis of essential metals such as copper, iron, selenium and zinc may be altered in the brain of subjects with Alzheimer's disease. It is demonstrated that the plasma concentrations of manganese and total mercury were significantly higher in subjects with AD than in controls, however the concentrations of vanadium, manganese, rubidium, antimony, cesium and lead were significantly lower among subjects with AD cerebrospinal fluid. The influence of metal ions such as Fe, Cu, and Zn in stimulating Aβ aggregation have been widely studied where they appears to vary depending on tissue pH. It should be noticed that, although there is co-localization of metal ions in the pathological markers of AD, this does not indicate a causative role for these elements in the pathogenesis of the disease. Independently of metals being a primary cause or consequence of the disease mechanism, a change in a single metal ion can cause a significant imbalance on homeostasis in elemental levels in the body (serum, CSF and brain) leading to as a sort of "domino effect". It is clear the need to understand the fundamental biochemical mechanisms linking brain biometal metabolism, environmental metal exposure, genotoxicity and AD pathophysiology. In this review, we discuss the role of metals in Alzheimer disease and its involvement in genotoxicity. 2. Source of metal exposure Metals have been used throughout human history to make several utensils, machines, jewelry, and so on, where many of then were obtained through mining and smelting, activities that increases their distribution throughout the environment. Furthermore, the use of metals in industry, medicine, agriculture have been increased over the years, which increase the exposure, not only for those workers involved directly in working with metals but also consumers of the products and the general public through environmental contamination (Ferrer, 2003; Ansari et al., 2004).

Toxicology in Vitro, 2008

Iron (Fe) is a common chemical element that is essential for organisms as a co-factor in oxygen t... more Iron (Fe) is a common chemical element that is essential for organisms as a co-factor in oxygen transport, but that in high amounts presents a significant risk of neurodegenerative disorders. The objective of this study was to evaluate the mutagenic potential of iron sulfate. The comet assay and chromosome aberration (CA) analysis were applied to determine the DNA-damaging and clastogenic effects of iron sulfate. Human lymphocytes were treated in the quiescent phase for the comet assay and proliferative phase during the G 1 , G 1 /S, S (pulses of 1 and 6 h), and G 2 phases of the cell cycle for CA analysis, with 1.25, 2.5 and 5 lg/mL concentrations of FeSO 4 Á 7H 2 O. All tested concentrations were cytotoxic and reduced significantly the mitotic index (MI) in all phases of the cell cycle. They also induced CA in G 1 , G 1 /S and S (pulses of 1 and 6 h) phases. Iron sulfate also induced polyploidy in cells treated during G 1. In the comet assay, this metal did not induce significant DNA damage. Our results show that Fe causes alteration and inhibition of DNA synthesis only in proliferative cells, which explain the concomitant occurrence of mutagenicity and cytotoxicity, respectively, in the lymphocytes studied.

Toxicology in Vitro, 2008

Manganese (Mn) has a natural occurrence and is necessary during the initial periods of the develo... more Manganese (Mn) has a natural occurrence and is necessary during the initial periods of the development. However, in high concentrations, Mn can be related to neurodegenerative disorders. The aim of the present study was to evaluate the mutagenic potential of manganese chloride (MnCl 2 Á 4H 2 O). Comet assay and chromosome aberrations analysis were applied to determine the DNA-damaging and clastogenic effects of MnCl 2 Á 4H 2 O. Cultured human lymphocytes were treated with 15, 20 and 25 lM manganese chloride during the G1, G1/S, S (pulses of 1 and 6 h), and G2 phases of the cell cycle. All tested concentrations were cytotoxic and reduced significantly the mitotic index in G1, G1/S and S (1 and 6 h) treatments, while in G2 treatment only the higher concentrations (20 and 25 lM) showed cytotoxic effects. Clastogenicity and DNA damage were found only in treatments with the highest concentration (25 lM). Chromosome aberrations were found exclusively in the G2 phase of the cell cycle. The absence of polyploidy in mitosis, suggests that manganese does not affect the formation of the mitotic spindle with the concentrations tested. The genotoxicity found in G2 phase and in the comet assay can be related to the short time of treatment in both cases.

Toxicology in Vitro, 2013

The down-regulation or loss of epithelial markers is often accompanied by the up-regulation of me... more The down-regulation or loss of epithelial markers is often accompanied by the up-regulation of mesenchymal markers. E-cadherin generally suppresses invasiveness, whereas N-cadherin promotes invasion and metastasis in vitro. The aim of this work is to investigate the role of biflorin, a naphthoquinone with proven anticancer properties, on the expression of N-cadherin and AKT proteins in MDA-MB-435 invasive melanoma cancer cells after 12 h of exposure to 1, 2.5 and 5 lM biflorin. Biflorin inhibited MDA-MB-435 invasion in a dose-dependent manner (p < 0.01). Likewise, biflorin down-regulated N-cadherin and AKT-1 expression in a dose-dependent manner. Biflorin did not inhibit the adhesion of MDA-MB-435 cells to any tested substrates. Additionally, biflorin blocked the invasiveness of cells by down-regulating N-cadherin, most likely via AKT-1 signaling. As such, biflorin may be a novel anticancer agent and a new prototype for drug design.

Journal of Applied Toxicology, 2010

Despite the remarkable progress in the characterization of the molecular pathogenesis of glioblas... more Despite the remarkable progress in the characterization of the molecular pathogenesis of glioblastoma multiforme (GBM), these tumors remain incurable and, in most cases, refractory to aggressive cytotoxic treatments. We conducted a morphological and cytogenetic study in two GBM cell lines (U343 and AHOL1), before and after treatment with pisosterol (at 0.5, 1.0 and 1.8 mg ml-1), a triterpene isolated from the fungus Pisolithus tinctorius. No significant alteration was observed in the morphology and frequency of chromosomal abnormalities in the cell lines analyzed after treatment with pisosterol. Using fluorescence in situ hybridization analysis with a locus-specific probe for C-MYC showed that 72% of U343 and 65% of AHOL1 cells contained more than two alleles of C-MYC before treatment. After treatment, no effects were detected at lower concentrations of pisosterol (0.5 and 1.0 mg ml-1). However, at 1.8 mg ml-1 of pisosterol, only 33% of U343 cells and 15% of AHOL1 cells presented more than two fluorescent signals, suggesting that pisosterol blocks the cells with gene amplification. Cells that do not show a high degree of C-MYC gene amplification have a less aggressive and invasive behavior and are easy targets for chemotherapy. Therefore, further studies are needed to examine the use of pisosterol in combination with conventional anti-cancer therapy.

International Journal of Cardiology, 2014

Background: Oral bacteria have been detected in atherosclerotic plaques at a variable frequency; ... more Background: Oral bacteria have been detected in atherosclerotic plaques at a variable frequency; however, the connection between oral health and vascular and oral bacterial profiles of patients with vascular disease is not clearly established. The aim of this study was to evaluate the presence of oral bacterial DNA in the mouth and atherosclerotic plaques, in addition to assessing the patients' caries and periodontal disease history. Methods: Thirty samples of supragingival and subgingival plaque, saliva and atherosclerotic plaques of 13 patients with carotid stenosis or aortic aneurysm were evaluated, through real-time polymerase chain reaction, for the presence of Streptococcus mutans (SM), Prevotella intermedia (PI), Porphyromonas gingivalis (PG) and Treponema denticola (TD). All patients were submitted to oral examination using the DMFT (decayed, missing and filled teeth) and PSR (Periodontal Screening and Recording) indexes. Histopathological analysis of the atherosclerotic plaques was performed. Results: Most of the patients were edentulous (76.9%). SM, PI, PG and TD were detected in 100.0%, 92.0%, 15.3% and 30.7% of the oral samples, respectively. SM was the most prevalent targeted bacteria in atherosclerotic plaques, detected in 100% of the samples, followed by PI (7.1%). The vascular samples were negative for PG and TD. There was a statistically significant difference (p b 0.05) between the presence of PG and TD in the oral cavity and vascular samples. Conclusion: SM was found at a high frequency in oral and vascular samples, even in edentulous patients, and its presence in atherosclerotic plaques suggests the possible involvement of this bacterium in the disease progression.

Industrial Crops and Products, 2014

The hydrodistilled oils of Piper hispidum, Piper aleyreanum, and Piper anonifolium, collected in ... more The hydrodistilled oils of Piper hispidum, Piper aleyreanum, and Piper anonifolium, collected in the Carajás National Forest, Pará state, Brazil, were analyzed by GC and GC-MS and then, evaluated their antioxidant, antifungal, anticholinesterase and cytotoxic activities. In total, 87 constituents were identified in the Piper oils. The sesquiterpenes were the most highly represented classes and the main compounds found in the Piper oils were selin-11-en-4-␣-ol, ␤-elemene, ␤-selinene, ␣-selinene, bicyclogermacrene, ␤-caryophyllene, ␣-humulene, and ␦-elemene. All analyzed oils showed powerful antifungal activity, with the detection limit (DL) from 0.1 to 1.0 g against the Cladosporium cladosporioides and Cladosporium sphareospermum fungi, as well they have no lytic effect against the mice erythrocytes. In the anticholinesterase evaluation, the oils of P. anonifolium (DL = 0.01 ng) and P. hispidum (DL = 0.01 ng) were hundred times more potent than the standard physostigmine (DL = 1.0 ng). Moreover, the oil of P. aleyreanum showed high in vitro cytotoxic activity against the human melanoma cell line SKMEL-19 (IC 50 = 7.4 g/mL) and significant antioxidant activity (DPPH = 412.2 mg TE/mL). The higher cell growth inhibition induced by the oil of P. aleyreanum is probably due to elemene (␤-, ␦-, and ␥-elemene), as well as other structurally related compounds, which were previously reported in the proliferation inhibition, stimulation of apoptosis and induction of cell cycle arrest in malignant cells.

Cell cycle arrest induced by Pisosterol in HL60 cells with gene amplification

Cell Biology and Toxicology, 2008

The leukemia cell line HL60 is widely used in studies of the cell cycle, apoptosis, and adhesion ... more The leukemia cell line HL60 is widely used in studies of the cell cycle, apoptosis, and adhesion mechanisms in cancer cells. We conducted a focused cytogenetic study in an HL60 cell line, by analyzing GTG-banded chromosomes before and after treatment with pisosterol (at 0.5, 1.0, and 1.8 microg/ml), a triterpene isolated from Pisolithus tinctorius, a fungus collected in the Northeast of Brazil. Before treatment, 99% of the cells showed the homogeneously staining region (HSR) 8q24 aberration. After treatment with 1.8 microg/ml pisosterol, 90% of the analyzed cells lacked this aberration. We further performed a pulse test, in which the cells treated with pisosterol (0.5, 1.0, and 1.8 microg/ml) were washed and re-incubated in the absence of pisosterol. Only 30% of the analyzed cells lacked the HSR 8q24 aberration, suggesting that pisosterol probably blocks the cells with HSRs at interphase. No effects were detected at lower concentrations. At the highest concentration examined (1.8 microg/ml), pisosterol also inhibited cell growth, but this effect was not observed in the pulse test, reinforcing our hypothesis that, at the concentrations tested, pisosterol probably does not induce cell death in the HL60 line. The results found for pisosterol were compared with those for doxorubicin. Cells that do not show a high degree of gene amplification (HSRs and double-minute chromosomes) have a less aggressive and invasive behavior and are easy targets for chemotherapy. Therefore, further studies are needed to examine the use of pisosterol in combination with conventional anti-cancer therapy.

BMC Gastroenterology, 2012

Background Gastric cancer is a serious public health problem in Northern Brazil and in the world ... more Background Gastric cancer is a serious public health problem in Northern Brazil and in the world due to its high incidence and mortality. Despite the severity of the disease, more research is needed to better understand the molecular events involved in this intestinal-type gastric carcinogenesis process. Since precancerous lesions precede intestinal-type gastric cancer, here, we evaluated the hTERT, MYC, and TP53 mRNA and protein expression, as well as TP33 copy number, in gastric preneoplastic lesions. Methods We evaluated 19 superficial gastritis, 18 atrophic gastritis, and 18 intestinal metaplasia from cancer-free individuals of Northern Brazil. Quantitative reverse transcription PCR was used to analyze the mRNA expression and immunohistochemical methods were used to assess protein immunoreactivity in tissue samples. The number of TP53 gene copies was investigated in gastric diseases by quantitative PCR. Results We observed hTERT, MYC, and p53 immunoreactivity only in intestinal ...

Molecules, 2014

As part of a continuing search for new potential anticancer candidates, we describe the synthesis... more As part of a continuing search for new potential anticancer candidates, we describe the synthesis, cytotoxicity and mechanistic evaluation of a series of 4-oxoquinoline-3-carboxamide derivatives as novel anticancer agents. The inhibitory activity of compounds 10-18 was determined against three cancer cell lines using the MTT colorimetric assay. The screening revealed that derivatives 16b and 17b exhibited significant cytotoxic activity against the gastric cancer cell line but was not active against a normal cell line, in contrast to doxorubicin, a standard chemotherapeutic drug in clinical use. Interestingly, no hemolytical activity was observed when the toxicity of 16b and 17b was tested against blood cells. The in silico and in vitro mechanistic evaluation indicated

Pisosterol induces interphase arrest in HL60 cells with C-MYC amplification

Human & Experimental Toxicology, 2010

The leukaemia cell line HL60 is widely used in studies of the cell cycle, apoptosis and adhesion ... more The leukaemia cell line HL60 is widely used in studies of the cell cycle, apoptosis and adhesion mechanisms in cancer cells. One marked characteristic of HL60 cells is the C-MYC proto-oncogene amplification, resulting in the formation of homogeneously staining regions (HSRs) at 8p24. We conducted a fluorescence in situ hybridization study in an HL60 cell line, using a locus-specific probe for C-MYC, before and after treatment with pisosterol (at 0.5, 1.0 and 1.8 μg/mL), a triterpene isolated from the fungus Pisolithus tinctorius. Before treatment, 87.5% of the cells showed HSRs. After treatment, no effects were detected at lower concentrations of pisosterol (0.5 and 1.0 μg/mL). However, at 1.8 μg/mL only 15% of the cells presented HSRs, and 39.5% presented few fluorescent signals (3 or 4 alleles), suggesting that pisosterol probably blocks the cells with HSRs at interphase. This result is particularly interesting because cells that do not show a high degree of C-MYC gene amplificati...

Additional file 1: of mtDNA structure: the women who formed the Brazilian Northeast

Mitochondrial DNA ancestral group frequencies in other Brazilian geopolitical regions. (DOCX 30 kb)

Dementia & Neuropsychologia, 2021

Background: COVID-19 neurological manifestations were demonstrated during the pandemic, including... more Background: COVID-19 neurological manifestations were demonstrated during the pandemic, including cognitive impairment. Objectives: To determine the prevalence of cognitive and behavioral complaints (such as dementia, MCI or SCD) in a outpatient sample with recent SARS-COV2 infection. Specific: Evaluate the association of cognitive impairment with the presence of the polymorphism found in the APOE gene and with respiratory disease. Methodology: Observational, longitudinal, prospective clinical study. Inclusion criteria: patients with confirmed Covid-19. Patients are evaluated in an outpatient clinic. They are evaluated through a standardized attendance record, with somatic and cognitive neurological assessment. Cognitive assessment involves the application of cognitive (ACER, MMSE and CDR), functional (Pfeffer) and psychiatric (GDS or Beck) screening instruments, in addition to subsequent extensive neuropsychological assessment. In addition, APOE polymorphism is analysed. Preliminar...