28 results on '"Vieira VC"'
Search Results
2. Older people involved in physical activity benefit from water exercise, showing longer total sleep time.
- Author
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Alencar KL, Carvalho LB, Prado LB, Vantini AL, Vieira VC, Cardoso AP, Alencar JP, Paes AT, Peres CA, and Prado GF
- Published
- 2006
- Full Text
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3. Behavior, BDNF and epigenetic mechanisms in response to social isolation and social support in middle aged rats exposed to chronic stress.
- Author
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Borges JV, Pires VN, de Freitas BS, Rübensam G, Vieira VC, de Souza Dos Santos C, Schröder N, and Bromberg E
- Subjects
- Rats, Animals, Rats, Sprague-Dawley, Hypothalamo-Hypophyseal System metabolism, Pituitary-Adrenal System metabolism, Social Isolation, Epigenesis, Genetic, Hippocampus metabolism, Stress, Psychological metabolism, Mammals metabolism, Histone Deacetylases genetics, Histone Deacetylases metabolism, Corticosterone metabolism, Brain-Derived Neurotrophic Factor genetics, Brain-Derived Neurotrophic Factor metabolism
- Abstract
Social deprivation can be stressful for group-living mammals. On the other hand, an amazing response of these animals to stress is seeking social contact to give and receive joint protection in threatening situations. We explored the effects of social isolation and social support on epigenetic and behavioral responses to chronic stress. More specifically, we investigated the behavioral responses, corticosterone levels, BDNF gene expression, and markers of hippocampal epigenetic alterations (levels of H3K9 acetylation and methylation, H3K27 methylation, HDAC5, DNMT1, and DNMT3a gene expressions) in middle-aged adult rats maintained in different housing conditions (isolation or accompanied housing) and exposed to the chronic unpredictable stress protocol (CUS). Isolation was associated with decreased basal levels of corticosterone, impaired long-term memory, and decreased expression of the BDNF gene, besides altering the balance of H3K9 from acetylation to methylation and increasing the DNMT1 gene expression. The CUS protocol decreased H3K9 acetylation, besides increasing H3K27 methylation and DNMT1 gene expression, but had no significant effects on memory and BDNF gene expression. Interestingly, the effects of CUS on corticosterone and HDAC5 gene expression were seen only in isolated animals, whereas the effects of CUS on DNMT1 gene expression were more pronounced in isolated than accompanied animals. In conclusion, social isolation in middle age showed broader effects than chronic unpredictable stress on behavioral and epigenetic alterations potentially associated with decreased BDNF expression. Moreover, social support prevented the adverse effects of CUS on HPA axis functioning, HDAC5, and DNMT1 gene expressions., Competing Interests: Declaration of Competing Interest All the other authors have no conflict of interest to disclose., (Copyright © 2023 Elsevier B.V. All rights reserved.)
- Published
- 2023
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4. High APOBEC3B mRNA Expression Is Associated with Human Papillomavirus Type 18 Infection in Cervical Cancer.
- Author
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de Oliveira GR, Carvalho PS, Vieira VC, Curty G, Basto DL, Moreira MÂM, and Soares MA
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- Female, Humans, DNA, Human papillomavirus 18, Minor Histocompatibility Antigens genetics, RNA, Messenger genetics, Cytidine Deaminase genetics, Papillomavirus Infections complications, Papillomavirus Infections genetics, Uterine Cervical Neoplasms genetics, Uterine Cervical Neoplasms virology
- Abstract
The APOBEC3 (A3) proteins are cytidine deaminases that exhibit the ability to insert mutations in DNA and/or RNA sequences. APOBEC3B (A3B) has been evidenced as a DNA mutagen with consistent high expression in several cancer types. Data concerning the A3B influence on HPV infection and cervical cancer are limited and controversial. We investigated the role of A3B expression levels in cervical cancer in affected women positive for infection by different HPV types. Tumor biopsies from cancerous uterine cervix were collected from 216 women registered at Hospital do Câncer II of Instituto Nacional de Câncer, and infecting HPV was typed. A3B expression levels were quantified from RNA samples extracted from cervical biopsies using real-time quantitative PCR. Median A3B expression levels were higher among HPV18
+ samples when compared to HPV16+ counterparts and were also increased compared to samples positive for other HPV types. In squamous cell carcinoma, HPV18+ samples also showed increased median A3B expression when compared to HPV Alpha-9 species or only to HPV16+ samples. Our findings suggest that A3B expression is differentially upregulated in cervical cancer samples infected with HPV18. A3B could be potentially used as a biomarker for HPV infection and as a prognostic tool for clinical outcomes in the context of cervical cancer.- Published
- 2022
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5. Corrigendum to 'Phylogenetic reconstruction of black yeast-like fungi (Chaetothyriales) with hypothetical gene of EIF2AK2 kinase as novel molecular marker'[Fungal Bio 124/12 (2020) 1032-1038].
- Author
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Assunção CB, de Aguiar EL, Al-Hatmi AMS, Silva Vieira VC, Machado AS, Junta C, de Hoog S, and Caligiorne RB
- Published
- 2021
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6. Live cell, image-based high-throughput screen to quantitate p53 stabilization and viability in human papillomavirus positive cancer cells.
- Author
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Martínez-Noël G, Vieira VC, Szajner P, Lilienthal EM, Kramer RE, Boyland KA, Smith JA, and Howley PM
- Subjects
- Apoptosis drug effects, Cell Line, Tumor, Cell Proliferation drug effects, DNA-Binding Proteins metabolism, Female, HeLa Cells, Human papillomavirus 18 genetics, Humans, Oncogene Proteins, Viral metabolism, Papillomavirus Infections diagnosis, Papillomavirus Infections diagnostic imaging, Papillomavirus Infections pathology, Uterine Cervical Neoplasms genetics, Uterine Cervical Neoplasms virology, Aurora Kinases antagonists & inhibitors, Cyclin-Dependent Kinases antagonists & inhibitors, High-Throughput Screening Assays methods, Histone Deacetylase Inhibitors pharmacology, Topoisomerase Inhibitors pharmacology, Tumor Suppressor Protein p53 metabolism
- Abstract
Approximately 5% of cancers are caused by high-risk human papillomaviruses. Although very effective preventive vaccines will reduce this cancer burden significantly over the next several decades, they have no therapeutic effect for those already infected and remaining at risk for malignant progression of hrHPV lesions. HPV-associated cancers are dependent upon the expression of the viral E6 and E7 oncogenes. The oncogenic function of hrHPV E6 relies partially on its ability to induce p53 degradation. Since p53 is generally wildtype in hrHPV-associated cancers, p53 stabilization arrests proliferation, induces apoptosis and/or results in senescence. Here we describe a live cell, image-based high-throughput screen to identify compounds that stabilize p53 and/or affect viability in HPV-positive cancer HeLa cells. We validate the robustness and potential of this screening assay by assessing the activities of approximately 6,500 known bioactive compounds, illustrating its capability to function as a platform to identify novel therapeutics for hrHPV., (Copyright © 2021 Elsevier Inc. All rights reserved.)
- Published
- 2021
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7. Prescription of off-label and unlicensed drugs for preterm infants in a neonatal intensive care unit.
- Author
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Vieira VC, Costa RS, Lima RCG, Queiroz DB, and Medeiros DS
- Subjects
- Cohort Studies, Humans, Infant, Infant, Newborn, Infant, Premature, Off-Label Use, Prescriptions, Intensive Care Units, Neonatal, Pharmaceutical Preparations
- Abstract
Objective: To evaluate the use of off-label and unlicensed medications in preterm infants hospitalized in a neonatal intensive care unit., Methods: This nonconcurrent cohort study included preterm infants admitted to 3 neonatal intensive care units in 2016 and 2017 who were followed up during the neonatal period. The type and number of medications used were recorded for the entire period and classified based on the Anatomical Therapeutic Chemical. Descriptive and bivariate data analyses were performed to assess associations between the number of drugs used (total, off-label and unlicensed) and the explanatory variables of interest., Results: Four hundred preterm infants received 16,143 prescriptions for 86 different pharmaceuticals; 51.9% of these medications were classified as off-label and 23.5% as unlicensed. The most prescribed drugs were gentamicin and ampicillin (17.5% and 15.5% among off-label, respectively) and caffeine (75.5% among unlicensed). The results indicated significant associations between the use of off-label drugs and lower gestational age, low birth weight, lower 5-minute Apgar score, advanced resuscitation maneuver in the delivery room and death. The prescription of unlicensed drugs was associated with lower gestational age, low birth weight and 5-minute Apgar score below 7., Conclusion: Neonates admitted to neonatal intensive care units are highly exposed to off-label and unlicensed medications. Further studies are needed to achieve greater safety and quality of drug therapy used in neonatology.
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- 2021
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8. Premature birth: topics in physiology and pharmacological characteristics.
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Machado JS, Ferreira TS, Lima RCG, Vieira VC, and Medeiros DS
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- Female, Humans, Infant, Infant, Low Birth Weight, Infant, Newborn, Infant, Premature, Pregnancy, Infant, Premature, Diseases, Premature Birth
- Abstract
Objective: To review the main physiological and pharmacological changes related to prematurity, to promote the evidence-based clinical practice., Methods: This is a narrative review whose research was carried out in the ScienceDirect and Medline databases via PubMed, searching for articles in any language from January 2000 to February 2020., Results: Premature newborns are born before completing the maturation process that prepares them for extrauterine life, which occurs especially in the last weeks of pregnancy. Therefore, they have their own characteristics in development. Several physiological peculiarities stand out, such as disturbances in glucose regulation, adrenal function, thermoregulation, immunity, in addition to changes in liver, renal and respiratory functions. Pharmacological aspects were also highlighted, involving pharmacokinetics and pharmacodynamics., Conclusions: Despite the recent advances in prematurity, it is still an area with many uncertainties, since several changes occur quickly and there are ethical issues that make studies difficult. Thus, it is clear that the therapeutic management of premature infants is still very much based on clinical practice.
- Published
- 2021
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9. New molecular marker for phylogenetic reconstruction of black yeast-like fungi (Chaetothyriales) with hypothetical EIF2AK2 kinase gene.
- Author
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Assunção CB, de Aguiar EL, Al-Hatmi AMS, Silva Vieira VC, Machado AS, Junta C, de Hoog S, and Caligiorne RB
- Subjects
- DNA, Ribosomal genetics, Ascomycota enzymology, Ascomycota genetics, Genes, Fungal, Phylogeny, eIF-2 Kinase genetics
- Abstract
In eukaryotes, phosphorylation of the α-subunit of eIF2 is a mechanism to adjust cellular gene expression profiles in response to specific signals. The eIF2α kinases are a group of serine-threonine kinases that perform important functions in response to infection, proteotoxicity, and nutrient scavenging. The conserved nature of eIF2α kinases among fungi makes them potential evolutionary markers, which may contribute to deeper understanding of taxonomy and evolution. To date, only few studies are available of eIF2α kinases in black yeasts, which are members of Chaetothyriales containing potential agents of a gamut of major human diseases, such as chromoblastomycosis, phaeohyphomycosis and mycetoma. To establish the phylogenetic validity of sequences of eIF2α kinases hypothetical genes, we compared these genes between members of different classes of fungi, including black yeasts and allies, aiming at evaluation of the phylogeny of this group using an alternative molecular marker, compared to standard ribosomal genes. Trees generated with eIF2α kinase sequences of fungi were compared with those generated by ribosomal internal transcribed spacers (ITS rDNA) sequences from the same species. Sequences used were obtained from the protein Non-redundant database of NCBI, were aligned using CLUSTALX v1.8 and alignments were analyzed with RAxML v8.2.9 on the CIPRES Science Gateway portal. The trees generated had similar topologies, demonstrating that eIF2α kinases hypothetical gene sequences present a coherent reflection of evolution among fungi, compared to trees reconstructed by the use of ribosomal sequences. Our preliminary findings with a limited dataset strongly suggest that the evolution of kinases among black yeasts follows a similar path as revealed by ribosomal data, which underlines the validity of current taxonomy of black yeasts and relatives., Competing Interests: Declaration of competing interest The authors have no conflicts of interest to declare and confirm that each one has made substantial contributions to the information or materials submitted for publication., (Copyright © 2020 British Mycological Society. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2020
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10. The papillomavirus E5 gene does not affect EGFR transcription and overall survival in cervical cancer.
- Author
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Basto DL, Chaves CBP, Felix SP, Amaro-Filho SM, Vieira VC, Martins LFL, de Carvalho NA, Almeida LM, and Moreira MÂM
- Subjects
- Adult, Carcinoma, Squamous Cell classification, ErbB Receptors genetics, ErbB Receptors metabolism, Female, Genome, Viral, Humans, Middle Aged, Signal Transduction, Survival Analysis, Vascular Endothelial Growth Factor A genetics, Carcinoma, Squamous Cell virology, Oncogene Proteins, Viral genetics, Transcription, Genetic, Uterine Cervical Neoplasms virology
- Abstract
Introduction: The human papillomavirus (HPV) E5 gene encodes a small and highly hydrophobic oncoprotein that affects immune evasion, cell proliferation, loss of apoptotic capacity and angiogenesis in tumors. E5 shows an affinity for biological membranes and was associated with an increase of epidermal growth factor/epidermal growth factor receptor (EGF/EGFR) signaling through the accumulation of EGFR in cellular membranes. Due to the frequent integration of the HPV genome into the host cell genome, E5 is frequently not transcribed in cervical tumors., Aim: In this study we looked forward to verifying whether the potential expression of E5 protein in human papillomavirus 16 positive (HPV16
+ ) and human papillomavirus 18 positive (HPV18+ ) cervical tumors was associated with levels of EGFR and vascular endothelial growth factor A (VEGFA) transcription and with patients overall survival., Results: Association between the presence of E5 transcripts and viral genome disruption was observed for HPV16+ and HPV18+ tumors. Association was not observed between tumors potentially capable of translating E5 and EGFR or VEGFA transcriptional levels. Similarly, the capability of translating E5 and overall survival in patients with HPV16+ squamous cell carcinoma tumors stage ≥ IB2 were not associated., Conclusion: The likely presence of E5 transcripts was neither associated to a higher activity of the EGFR-VEGFA pathway nor to the overall survival of patients with HPV16+ squamous cell carcinoma in stages ≥ IB2., (© 2019 Wiley Periodicals, Inc.)- Published
- 2020
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11. Characterisation of complete high- and low-risk human papillomavirus genomes isolated from cervical specimens in southern Brazil.
- Author
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Oliveira GR, Siqueira JD, Finger-Jardim F, Vieira VC, Silva RL, Gonçalves CV, Soares EA, Martinez AMB, and Soares MA
- Subjects
- Adult, Brazil, DNA, Viral, Female, Humans, Papillomaviridae isolation & purification, Phylogeny, Risk Factors, Vaginal Smears, Genome, Viral, Papillomaviridae genetics, Papillomavirus Infections virology, Uterine Cervical Diseases virology
- Abstract
The classification of human papillomavirus (HPV) intratypic lineages by complete genome sequencing is a determinant in understanding biological differences in association with this disease. In this work, we have characterised complete HPV genomes from southern Brazil. Fifteen cervicovaginal Pap smear negative samples previously categorised as HPV-positive were sequenced using ultradeep sequencing, and 18 complete genomes from 13 different HPV types were assembled. Phylogenetic and genetic distance analyses were performed to classify the HPV genomes into lineages and sublineages. This is the first report describing the distribution of HPV intratype lineages of high and low oncogenic risk in asymptomatic women from southern Brazil.
- Published
- 2017
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12. Human papillomavirus type distribution and HPV16 intratype diversity in southern Brazil in women with and without cervical lesions.
- Author
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de Oliveira GR, Vieira VC, Ávila EC, Finger-Jardim F, Caldeira TD, Gatti FA, Gonçalves CV, Oliveira SG, da Hora VP, Soares MA, and de Martinez AM
- Subjects
- Adult, Brazil, Cross-Sectional Studies, DNA, Viral genetics, Female, Humans, Polymerase Chain Reaction, Socioeconomic Factors, Genetic Variation genetics, Human papillomavirus 16 genetics, Papillomavirus Infections virology, Uterine Cervical Dysplasia virology, Uterine Cervical Neoplasms virology
- Abstract
Background: Increasing evidence suggests that human papillomavirus (HPV) intratype variants (specific lineages and sublineages) are associated with pathogenesis and progression from HPV infection to persistence and the development of cervical cancer., Objectives: This study aimed to verify the prevalence of HPV infection and distribution of HPV types and HPV16 variants in southern Brazil in women with normal cytology or intraepithelial lesions., Methods: HPV typing was determined by L1 gene sequencing. To identify HPV16 variants, the LCR and E6 regions were sequenced, and characteristic single nucleotide variants were identified., Findings: A total of 445 samples were studied, with 355 from cervical scrapes and 90 from cervical biopsies. HPV was detected in 24% and 91% of these samples, respectively. The most prevalent HPV types observed were 16 (cervical, 24%; biopsies, 57%) and 58 (cervical, 12%; biopsies, 12%). Seventy-five percent of the HPV16-positive samples were classified into lineages, with 88% defined as lineage A, 10% as lineage D, and 2% as lineage B., Main Conclusions: This study identified a high frequency of European and North American HPV16 lineages, consistent with the genetic background of the human population in southern Brazil.
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- 2017
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13. Efficacy of imidazolquinoline on treatment of condyloma acuminatum of the buccal mucosa.
- Author
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Curi DS, Leite-Ribeiro PM, Torregrossa VR, Vieira VC, and Sarmento VA
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- Adult, Humans, Male, Aminoquinolines therapeutic use, Anti-HIV Agents therapeutic use, Condylomata Acuminata drug therapy, HIV Infections drug therapy, Mouth Mucosa drug effects, Mouth Mucosa virology
- Abstract
The condylomata acuminata is a benign epithelial neoplasm induced by papillomavirus, and it is characterized by the proliferation of stratified squamous epithelial tissue that affects the anogenital and oral mucosa. It is considered to be a sexually transmitted disease and has a higher prevalence in individuals infected with human immunodeficiency virus. Various therapies have been used for the removal of lesions, such as cryotherapy, surgical laser and surgical excision, which are painful and scarring. These techniques, however, do not eliminate the virus and relapses are common shortly after treatment. The use of immunomodulators has been proposed to be an alternative treatment, as imidazolquinoline has been shown to be effective in the treatment of lesions in the anogenital region. However, its use in the oral cavity has been the subject of few reports in the literature. Thus, the objective of this study is to describe a case of warts in the labial mucosa of an HIV positive patient using imidazolquinoline 5%., (© 2016 Special Care Dentistry Association and Wiley Periodicals, Inc.)
- Published
- 2017
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14. Effect of Ocimum gratissimum in Mouthrinses on De Novo Plaque Formation. A Randomized Clinical Trial.
- Author
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Pimenta MS, Lobo NS, Vieira VC, Costa ÂM, Costa FN, and Pereira SL
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- Adolescent, Adult, Chlorhexidine administration & dosage, Chlorhexidine analogs & derivatives, Cross-Over Studies, Dental Plaque Index, Double-Blind Method, Female, Humans, Male, Young Adult, Dental Plaque prevention & control, Mouthwashes, Ocimum
- Abstract
The aim of this study was to evaluate the antiplaque effect of Ocimum gratissimum (Og) by in vivo investigation. Fifteen healthy volunteers participated in a crossover, double-blind clinical study, using a 3-day partial-mouth plaque accumulation model. The participants abolished any method of mechanical oral hygiene and they were randomly assigned to initially use just the following mouthrinses: distilled water (DW solution), 0.12% chlorhexidine digluconate (CLX solution) or 10% Og (Og solution). The plaque index (PLI) was recorded in all mandibular teeth at the end of the trial and the Kruskal-Wallis (α=0.05) and Mann-Whitney (α=0.05) tests were used to estimate the difference among groups. The clinical results showed statistically significant difference among the groups (p<0.05), favoring the CLX solution and Og solution, but the first was more effective (p<0.05). The mouthrinses containing 0.12% chlorhexidine digluconate and 10% Og were able to inhibit plaque re-growth, however Og showed more limited results in comparison to CLX.
- Published
- 2016
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15. Quantitative transportation assessment in curved canals prepared with an off-centered rectangular design system.
- Author
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Silva EJ, Vieira VC, Tameirão MD, Belladonna FG, Neves Ade A, Souza EM, and DE-Deus G
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- Analysis of Variance, Equipment Design, Image Processing, Computer-Assisted, Materials Testing, Models, Anatomic, Nickel chemistry, Reproducibility of Results, Root Canal Preparation methods, Titanium chemistry, Dental Instruments, Dental Pulp Cavity anatomy & histology, Root Canal Preparation instrumentation
- Abstract
The purpose of this study was to assess the ability of an off-centered rectangular design system [ProTaper Next (PTN)] to maintain the original profile of the root canal anatomy. To this end, ProTaper Universal (PTU), Reciproc (R) and WaveOne (WO) systems were used as reference techniques for comparison. Forty clear resin blocks with simulated curved root canals were randomly assigned to 4 groups (n = 10) according to the instrumentation system used: PTN, PTU, R and WO. Color stereomicroscopic images of each block were taken before and after instrumentation. All image processing and data analysis were performed with an open source program (Fiji v.1.47n). Evaluation of canal transportation was obtained for two independent regions: straight and curved portions. Univariate analysis of variance and Tukey's Honestly Significant Difference test were performed, and a cut-off for significance was set at α = 5%. Instrumentation systems significantly influenced canal transportation (p = 0.000). Overall, R induced significantly lower canal transportation compared with WO, PTN and PTU (p = 0.000). The curved portion displayed superior canal transportation compared to the straight one (p = 0.000). The significance of the difference among instrumentation systems varied according to the canal level evaluated (p = 0.000). In its straight portion, R and WO exhibited significantly lower transportation than PTN; whereas in the curved portion, R produced the lowest deviation. PTU exhibited the highest canal transportation at both levels. It can be concluded that PTN produced less canal transportation than PTU and WO; however, R exhibited better centering ability than PTN.
- Published
- 2016
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16. [Acute pain from the perspective of minor trauma patients treated at the emergency unit].
- Author
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Martin AR, Soares JR, Vieira VC, Marcon SS, and Barreto Mda S
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- Accidents, Home, Acute Pain etiology, Acute Pain nursing, Adolescent, Adult, Aged, Anxiety etiology, Brazil, Emergencies, Emotions, Female, Humans, Interviews as Topic, Male, Middle Aged, Qualitative Research, Stress, Physiological, Stress, Psychological etiology, Wounds and Injuries complications, Wounds and Injuries nursing, Young Adult, Acute Pain psychology, Emergency Service, Hospital, Pain Perception, Wounds and Injuries psychology
- Abstract
Objective: To study the factors that influence the perception of acute pain and the consequences of this experience in patients suffering from mild trauma., Method: Descriptive qualitative study conducted in an emergency service in southern Brazil. Data was collected in October 2013, through semi-structured interviews with 29 individuals who reported pain after physical trauma, regardless of the triggering factor. To process the data, we used a Content Analysis technique, subject modality., Results: Two categories emerged: Factors that influence the perception of pain resulting from trauma and, Consequences of acute pain due to trauma. The acute pain sensation was influenced by biological, emotional, spiritual and socio-cultural factors and induced biological and emotional consequences for individuals., Conclusion: The health professionals need to consider the factors that influence soreness and its consequences for the proper assessment and management of pain resulting from trauma.
- Published
- 2015
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17. Human papillomavirus E6 triggers upregulation of the antiviral and cancer genomic DNA deaminase APOBEC3B.
- Author
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Vieira VC, Leonard B, White EA, Starrett GJ, Temiz NA, Lorenz LD, Lee D, Soares MA, Lambert PF, Howley PM, and Harris RS
- Subjects
- Cells, Cultured, Humans, Keratinocytes enzymology, Keratinocytes virology, Minor Histocompatibility Antigens, Mutation, Transduction, Genetic, Transfection, Up-Regulation, Cytidine Deaminase biosynthesis, DNA-Binding Proteins metabolism, Host-Pathogen Interactions, Oncogene Proteins, Viral metabolism, Papillomaviridae physiology, Repressor Proteins metabolism
- Abstract
Unlabelled: Several recent studies have converged upon the innate immune DNA cytosine deaminase APOBEC3B (A3B) as a significant source of genomic uracil lesions and mutagenesis in multiple human cancers, including those of the breast, head/neck, cervix, bladder, lung, ovary, and other tissues. A3B is upregulated in these tumor types relative to normal tissues, but the mechanism is unclear. Because A3B also has antiviral activity in multiple systems and is a member of the broader innate immune response, we tested the hypothesis that human papillomavirus (HPV) infection causes A3B upregulation. We found that A3B mRNA expression and enzymatic activity were upregulated following transfection of a high-risk HPV genome and that this effect was abrogated by inactivation of E6. Transduction experiments showed that the E6 oncoprotein alone was sufficient to cause A3B upregulation, and a panel of high-risk E6 proteins triggered higher A3B levels than did a panel of low-risk or noncancer E6 proteins. Knockdown experiments in HPV-positive cell lines showed that endogenous E6 is required for A3B upregulation. Analyses of publicly available head/neck cancer data further support this relationship, as A3B levels are higher in HPV-positive cancers than in HPV-negative cancers. Taken together with the established role for high-risk E6 in functional inactivation of TP53 and published positive correlations in breast cancer between A3B upregulation and genetic inactivation of TP53, our studies suggest a model in which high-risk HPV E6, possibly through functional inactivation of TP53, causes derepression of A3B gene transcription. This would lead to a mutator phenotype that explains the observed cytosine mutation biases in HPV-positive head/neck and cervical cancers., Importance: The innate immune DNA cytosine deaminase APOBEC3B (A3B) accounts for a large proportion of somatic mutations in cervical and head/neck cancers, but nothing is known about the mechanism responsible for its upregulation in these tumor types. Almost all cervical carcinomas and large proportions of head/neck tumors are caused by human papillomavirus (HPV) infection. Here, we establish a mechanistic link between HPV infection and A3B upregulation. The E6 oncoprotein of high-risk, but not low-risk, HPV types triggers A3B upregulation, supporting a model in which TP53 inactivation causes a derepression of A3B gene transcription and elevated A3B enzyme levels. This virus-induced mutator phenotype provides a mechanistic explanation for A3B signature mutations observed in HPV-positive head/neck and cervical carcinomas and may also help to account for the preferential cancer predisposition caused by high-risk HPV isolates., (Copyright © 2014 Vieira et al.)
- Published
- 2014
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18. Dimethyl 2-nitro-biphenyl-4,4'-di-carboxyl-ate.
- Author
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Vieira VC, Golen JA, Rheingold AL, and Manke DR
- Abstract
The title compound, C16H13NO6, exhibits a biphenyl unit with a dihedral angle between the two aryl rings of 56.01 (5)°. The two ester groups vary slightly from planarity, with ar-yl-ester dihedral angles of 4.57 (5) and 16.73 (5)°. The nitro group is turned from the aromatic unit with an ar-yl-nitro dihedral angle of 48.66 (4)°. In the crystal, mol-ecules are connected by weak C-H⋯O inter-actions, forming a three-dimensional network.
- Published
- 2014
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19. Protoporphyrin fluorescence induced by methyl-ALA in skin healing.
- Author
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Gondim RM, Vieira VC, Veras MM, Ferreira MA, Caldini ÉT, Muñoz DR, and Baptista MS
- Subjects
- Aging pathology, Animals, Biomarkers metabolism, Mice, Mice, Nude, Photosensitizing Agents, Reproducibility of Results, Sensitivity and Specificity, Skin injuries, Skin pathology, Wounds, Penetrating pathology, Aging metabolism, Levulinic Acids analysis, Protoporphyrins analysis, Skin chemistry, Spectrometry, Fluorescence methods, Wound Healing physiology, Wounds, Penetrating metabolism
- Abstract
Background: Estimation of the time period that precedes an injury is critical in forensic medicine. However, there is no reliable method that can be used to evaluate the oldness of a lesion. The aim of this work is to develop a fluorimetric method that can be used to follow the aging process of lesions by applying methyl-ALA (MAL) on wounds and by quantifying protoporphyrin IX (PPIX) fluorescence during the healing process. We also aim to understand the changes in PPIX fluorescence by establishing a correlation with histological evaluations during the healing process., Methods: Standardized linear wounds were made on the dorsum of 72 mice, which were divided in control (MAL -) and experimental (MAL +) groups. In vivo fluorescence spectra (FS) were collected from normal and wound skin sites of control and experimental groups, corresponding to four groups of FS spectra: (a) FS of skin wound after MAL (+/+); (b) FS of normal skin after MAL (-/+); (c) FS of skin wound without MAL (+/-) and (d) FS of normal skin without MAL (-/-). Animals were monitored periodically for 3 months and euthanized. Tissue specimens were processed for histological analysis using design-based stereological methods. Serial cross-sections were analyzed to evaluate the organization of the dermis and epidermis, collagen deposition and cellular proliferation., Results: FS of skin wound with MAL (+/+) showed an expressive intensity increase from the beginning of the experiment to the 34th day, with maximum fluorescence being observed on the ≈ 11 th day after wounding. There was preferential PPIX accumulation in healing sites as compared to adjacent normal skin (+/-) in the early stage of healing. Histological findings allowed correlation of the fluorescence increase mainly with cell proliferation. The drastic decrease in the FS intensity observed in the end of the healing process was correlated with the decrease in the proliferation rate as well as with the presence of new extracellular fibrous materials., Conclusions: In the mice wound-healing model tested here, it was possible to distinguish whether the injury was in early or advanced stages by using PPIX fluorescence induced by MAL. We conclude that this method is a promising approach to evaluate the age of skin wounding and we hope this work will stimulate human studies to allow this technique to become standardized in forensic medicine., (Copyright © 2013 Elsevier B.V. All rights reserved.)
- Published
- 2013
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20. [Prevalence of Chlamydia trachomatis and risk factors associated with infection detected in endocervical sample].
- Author
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Garcês AX, de Martinez AM, Gonçalves CV, Germano FN, Barral MF, and Vieira VC
- Subjects
- Adolescent, Adult, Cervix Uteri microbiology, Cross-Sectional Studies, Female, Humans, Prevalence, Risk Factors, Young Adult, Chlamydia Infections epidemiology, Chlamydia trachomatis
- Abstract
Purpose: It was to determine the prevalence of Chlamydia trachomatis and the risk factors associated with infection in endocervical specimens from women seen in outpatient Obstetrics and Gynecology., Methods: Samples of endocervical secretion of 200 women treated at the University Hospital of the Federal University of Rio Grande were analyzed for the presence of C. trachomatis by polymerase chain reaction (PCR) using primers that amplify CT05/CT06 281 base pairs of the main outer membrane protein of C. trachomatis. All participants completed a pre-coded and self-report questionnaire. Data were analyzed with the SPSS 17.0 software; for multivariate analysis it was used Poisson regression., Results: Of the 200 women who were included in the study, the prevalence of infection with C. trachomatis was 11% (22 patients) and these 55 (27.5%) were positive for HPV. Risk factors associated with infection by C. trachomatis were: 8 years or less of schooling (p<0.001), family income below the poverty level (p=0.005), first intercourse at age 15 or less (p=0.04) and being a carrier of the virus HIV (p<0.001). After multivariate analysis, only the variables of schooling or less than eight years (PR 6.0; 95%CI 1.26 - 29.0; p=0.02) and presence of HIV (RP 14.1; 95%CI 3.4 - 57.5; p<0.001) remained statistically significant., Conclusions: The prevalence of C. trachomatis in endocervical specimens by PCR was 11%. The factors associated with a higher infection by C. trachomatis were lower education and being HIV positive.
- Published
- 2013
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21. [Risk factors and prevalence of HPV infection in patients from Basic Health Units of an University Hospital in Southern Brazil].
- Author
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de Oliveira GR, Vieira VC, Barral MF, Döwich V, Soares MA, Conçalves CV, and de Martinez AM
- Subjects
- Adult, Brazil, Cross-Sectional Studies, Female, Genotype, Hospitals, University, Humans, Papillomaviridae genetics, Papillomavirus Infections virology, Prevalence, Risk Factors, Young Adult, Papillomavirus Infections epidemiology
- Abstract
Purpose: To determine the HPV prevalence and genotypes and to identify factors associated with infection in pregnant and non-pregnant women with positive or negative HIV-1, treated in Gynecology and Obstetrics Ambulatories and in Health Primary Units, in Rio Grande, Rio Grande do Sul State, Brazil., Methods: Cervical cells samples from 302 patients were analyzed for HPV presence and genotypes were determined by nested and sequencing polymerase chain reaction. We calculated prevalence ratios associated with the studied variables by Fisher's exact or χ² tests, and Poisson's regression. Women with insufficient material were excluded from the study., Results: HPV was detected in 55 of the 302 women included in the study (18.2%); of these, 31 were pregnant, showing a significant association for HPV (p=0.04) when compared to non-pregnant ones. Risk factors for the infection were: patients aged <20 years-old (p=0.04), early initiation of sexual life (p=0.04), absence of cytological test (p=0.01), diagnosis of altered cytology (p=0.001), and counting <349 cells/mm³ (p=0.05). However, multi-parity was found to be a protective factor for the infection (p=0.01). Multivariate analysis showed that age <20 years-old (PR=2.8; 95%CI 1.0 - 7.7, p=0.04) and an altered cytological result (PR=11.1; 95%CI 3.0 - 4.1, p=0.001) were significantly associated with infection. HPV genotype was determined in 47 samples (85.4%) presenting one genotype per infection: eight HPV 16 and 58; six HPV 6; four HPV 18 and 33; three HPV 53 and 82; two HPV 83 and 61; one HPV 31, 35, 45, 64, 68, 71 and 85., Conclusions: The prevalence of HPV detection was 18.2%, the most frequent genotypes were 16 and 58, and sociodemographic and gynecological factors were associated with viral infection.
- Published
- 2013
- Full Text
- View/download PDF
22. The role of cytidine deaminases on innate immune responses against human viral infections.
- Author
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Vieira VC and Soares MA
- Subjects
- Cytidine Deaminase chemistry, Cytidine Deaminase genetics, Genetic Predisposition to Disease, Humans, Polymorphism, Genetic, Virus Diseases genetics, Cytidine Deaminase metabolism, Immunity, Innate immunology, Virus Diseases enzymology, Virus Diseases immunology
- Abstract
The APOBEC family of proteins comprises deaminase enzymes that edit DNA and/or RNA sequences. The APOBEC3 subgroup plays an important role on the innate immune system, acting on host defense against exogenous viruses and endogenous retroelements. The role of APOBEC3 proteins in the inhibition of viral infection was firstly described for HIV-1. However, in the past few years many studies have also shown evidence of APOBEC3 action on other viruses associated with human diseases, including HTLV, HCV, HBV, HPV, HSV-1, and EBV. APOBEC3 inhibits these viruses through a series of editing-dependent and independent mechanisms. Many viruses have evolved mechanisms to counteract APOBEC effects, and strategies that enhance APOBEC3 activity constitute a new approach for antiviral drug development. On the other hand, novel evidence that editing by APOBEC3 constitutes a source for viral genetic diversification and evolution has emerged. Furthermore, a possible role in cancer development has been shown for these host enzymes. Therefore, understanding the role of deaminases on the immune response against infectious agents, as well as their role in human disease, has become pivotal. This review summarizes the state-of-the-art knowledge of the impact of APOBEC enzymes on human viruses of distinct families and harboring disparate replication strategies.
- Published
- 2013
- Full Text
- View/download PDF
23. Are skeletally mature female rats a suitable model to study osteoporosis?
- Author
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Netto CC, Vieira VC, Marinheiro LP, Agellon S, Weiler H, and Maróstica MR Jr
- Subjects
- Absorptiometry, Photon, Age Factors, Aging physiology, Alkaline Phosphatase blood, Animals, Biomarkers blood, Bone Density, Calcium blood, Female, Femur metabolism, Femur physiopathology, Osteoporosis physiopathology, Rats, Receptor Activator of Nuclear Factor-kappa B blood, Reproducibility of Results, Time Factors, Disease Models, Animal, Osteoporosis metabolism
- Abstract
Objective: To analyze if female Wistar rats at 56 weeks of age are a suitable model to study osteoporosis., Materials and Methods: Female rats with 6 and 36 weeks of age (n = 8 per group) were kept over a 20-week period and fed a diet for mature rodents complete in terms of Ca, phosphorous, and vitamin D. Excised femurs were measured for bone mass using dual-energy x-ray absorptiometry, morphometry, and biomechanical properties. The following serum markers of bone metabolism were analyzed: parathyroid hormone (PTH), osteocalcin (OC), osteoprotegerin (OPG), receptor activator of nuclear factor Κappa B ligand (RANKL), C-terminal peptides of type I collagen (CTX-I), total calcium, and alkaline phosphatase (ALP) activity., Results: Rats at 56 weeks of age showed important bone metabolism differences when compared with the younger group, such as, highest diaphysis energy to failure, lowest levels of OC, CTX-I, and ALP, and elevated PTH, even with adequate dietary Ca., Conclusion: Rats at 26-week-old rats may be too young to study age-related bone loss, whereas the 56-week-old rats may be good models to represent the early stages of age-related changes in bone metabolism.
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- 2012
- Full Text
- View/download PDF
24. The effect of combined polymorphisms in chemokines and chemokine receptors on the clinical course of HIV-1 infection in a Brazilian population.
- Author
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Vieira VC, Barral MF, Mendoza-Sassi RA, Silveira JM, Soares MA, and de Martínez AM
- Subjects
- Adult, Disease Progression, Female, Gene Frequency genetics, Genetic Predisposition to Disease genetics, Genotype, Humans, Longitudinal Studies, Male, Polymerase Chain Reaction, Retrospective Studies, Chemokine CXCL12 genetics, HIV Infections genetics, Mutation genetics, Polymorphism, Genetic genetics, Receptors, CCR genetics
- Abstract
Polymorphisms in genes that encode chemokines or their receptors can modulate susceptibility to human immunodeficiency virus (HIV) infection and disease progression. The objective of this study was to assess the frequency of polymorphisms CCR5-Δ32, CCR2-64I, CCR5-59029A and SDF1-3'A and their role in the course of HIV infection in a Southern Brazilian population. Clinical data were obtained from 249 patients for an average period of 6.4 years and genotypes were determined by standard polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. Survival analyses were conducted for three outcomes: CD4+ T-cell counts below 200 cells/µL, acquired immune deficiency syndrome (AIDS) or death. The frequency of the polymorphisms CCR5-Δ32, CCR2-64I, CCR5-59029A and SDF1-3'A were 0.024, 0.113, 0.487 and 0.207, respectively. CCR5-Δ32 was associated with a reduction in the risk for CD4+ T-cell depletion and with an increased risk for death after AIDS diagnosis. CCR2-64I was associated with a reduction in the risk for developing AIDS. SDF1-3'A was also associated with decreased risk for AIDS, but its effect was only evident when CCR2-64I was present as well. These results highlight the possibility of using these markers as indicators for the prognosis of disease progression and provide evidence for the importance of analysing the effects of gene polymorphisms in a combined fashion.
- Published
- 2011
- Full Text
- View/download PDF
25. Langmuir films of petroleum at the air-water interface.
- Author
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Vieira VC, Severino D, Oliveira ON Jr, Pavinatto FJ, Zaniquelli ME, Ramos AP, and Baptista MS
- Subjects
- Air, Microscopy, Fluorescence, Water, Petroleum
- Abstract
Understanding the behavior of petroleum films at the air/water interface is crucial for dealing with oil slicks and reducing the damages to the environment, which has normally been attempted with studies of Langmuir films made of fractions of petroleum. However, the properties of films from whole petroleum samples may differ considerably from those of individual fractions. Using surface pressure and surface potential measurements and Brewster angle and fluorescence microscopy, we show that petroleum forms a nonhomogeneous Langmuir film at the air-water interface. The surface pressure isotherms for petroleum Langmuir films exhibit gas (G), liquid-expanded (LE), and liquid-condensed phases, with almost no hysteresis in the compression-decompression cycles. Domains formed upon compression from the G to the LE phase were accompanied by an increase in fluorescence intensity with excitation at 400-440 nm owing to an increase in the surface density of the chromophores in the petroleum film. The surface pressure and the fluorescence microscopy data pointed to self-assembling domains into a pseudophase in thermodynamic equilibrium with other less emitting petroleum components. This hypothesis was supported by Brewster angle microscopy images, whereby the appearance of water domains even at high surface pressures confirms the tendency of petroleum to stabilize emulsion systems. The results presented here suggest that, for understanding the interaction with water, it may be more appropriate to use the whole petroleum samples rather than its fractions.
- Published
- 2009
- Full Text
- View/download PDF
26. Photo-induced destruction of giant vesicles in methylene blue solutions.
- Author
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Caetano W, Haddad PS, Itri R, Severino D, Vieira VC, Baptista MS, Schröder AP, and Marques CM
- Subjects
- Methylene Blue, Phospholipids, Solutions, Lipid Bilayers radiation effects, Liposomes radiation effects, Photochemistry
- Abstract
We study the photodecomposition of phospholipid bilayers in aqueous solutions of methylene blue. Observation of giant unilamellar vesicles under an optical microscope reveals a consistent pattern of membrane disruption as a function of methylene blue concentration and photon density for different substrates supporting the vesicles.
- Published
- 2007
- Full Text
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27. Comparative cephalometric study between nasal and predominantly mouth breathers.
- Author
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Frasson JM, Magnani MB, Nouer DF, de Siqueira VC, and Lunardi N
- Subjects
- Child, Facial Bones physiopathology, Female, Humans, Radiography, Cephalometry, Facial Bones diagnostic imaging, Mouth Breathing physiopathology, Respiratory Mechanics physiology
- Abstract
Aim: To evaluate the possible correlation between the respiratory pattern in determining the craniofacial dimensions, using as baseline the Tweed-Merrifields cephalometric analysis, added to angle SN-GoGn and to Y axis angle., Methodology: The selected sample to this study comprised 50 teleradiographies taken in lateral and natural positions of the head in young female patients at the age of 9 to 12 years, presenting mean age of 10 years and 5 months and Class 1 malocclusion. After diagnosis of respiratory pattern, the sample was divided into two groups: control group, 25 teleradiographies of nasal breathers in lateral and natural positions of the head; experimental group, 25 teleradiographies of predominantly mouth breathers in lateral and natural positions of the head., Results: The results were submitted to descriptive analysis (mean and standard deviation), test F and "t" Student test with significance level of 5%. There was no significant difference between the group with nasal breathing and the group with predominantly mouth breathing for any of the studied variables.
- Published
- 2006
- Full Text
- View/download PDF
28. [Asymptomatic bacteriuria in childhood. Epidemiological survey in 1,017 children of Porto Alegre].
- Author
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Lobato O, Bischoff L, Pranke ML, Vieira VC, de Mello LS, and Alegre P
- Subjects
- Age Factors, Brazil, Child, Child, Preschool, Female, Humans, Male, Sex Factors, Bacteriuria epidemiology
- Published
- 1971
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