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1.
J Neurol ; 271(1): 1-23, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38015300

RESUMO

OBJECTIVE: This study aimed to synthesize the existing evidence on biomarkers related to coronavirus disease 2019 (COVID-19) patients who presented neurological events. METHODS: A systematic review of observational studies (any design) following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and the Cochrane Collaboration recommendations was performed (PROSPERO: CRD42021266995). Searches were conducted in PubMed and Scopus (updated April 2023). The methodological quality of nonrandomized studies was assessed using the Newcastle‒Ottawa Scale (NOS). An evidence gap map was built considering the reported biomarkers and NOS results. RESULTS: Nine specific markers of glial activation and neuronal injury were mapped from 35 studies published between 2020 and 2023. A total of 2,237 adult patients were evaluated in the included studies, especially during the acute phase of COVID-19. Neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) biomarkers were the most frequently assessed (n = 27 studies, 77%, and n = 14 studies, 40%, respectively). Although these biomarkers were found to be correlated with disease severity and worse outcomes in the acute phase in several studies (p < 0.05), they were not necessarily associated with neurological events. Overall, 12 studies (34%) were judged as having low methodological quality, 9 (26%) had moderate quality, and 9 (26%) had high quality. CONCLUSIONS: Different neurological biomarkers in neurosymptomatic COVID-19 patients were identified in observational studies. Although the evidence is still scarce and conflicting for some biomarkers, well-designed longitudinal studies should further explore the pathophysiological role of NfL, GFAP, and tau protein and their potential use for COVID-19 diagnosis and management.


Assuntos
COVID-19 , Adulto , Humanos , COVID-19/complicações , Teste para COVID-19 , Lacunas de Evidências , Biomarcadores/metabolismo , Neurônios/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo
3.
Sci Rep ; 13(1): 22270, 2023 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-38097608

RESUMO

Object recognition is a complex cognitive process that relies on how the brain organizes object-related information. While spatial principles have been extensively studied, less studied temporal dynamics may also offer valuable insights into this process, particularly when neural processing overlaps for different categories, as it is the case of the categories of hands and tools. Here we focus on the differences and/or similarities between the time-courses of hand and tool processing under electroencephalography (EEG). Using multivariate pattern analysis, we compared, for different time points, classification accuracy for images of hands or tools when compared to images of animals. We show that for particular time intervals (~ 136-156 ms and ~ 252-328 ms), classification accuracy for hands and for tools differs. Furthermore, we show that classifiers trained to differentiate between tools and animals generalize their learning to classification of hand stimuli between ~ 260-320 ms and ~ 376-500 ms after stimulus onset. Classifiers trained to distinguish between hands and animals, on the other hand, were able to extend their learning to the classification of tools at ~ 150 ms. These findings suggest variations in semantic features and domain-specific differences between the two categories, with later-stage similarities potentially related to shared action processing for hands and tools.


Assuntos
Mapeamento Encefálico , Encéfalo , Animais , Mapeamento Encefálico/métodos , Eletroencefalografia , Análise Multivariada , Percepção Visual
4.
Seizure ; 107: 132-135, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37023626

RESUMO

Onchocerciasis-associated epilepsy (OAE) is an important but neglected public health problem in onchocerciasis-endemic areas with insufficient or inadequate onchocerciasis control. Hence, there is a need for an internationally accepted, easy-to-use epidemiological case definition of OAE to identify areas of high Onchocerca volvulus transmission and disease burden requiring treatment and prevention interventions. By including OAE as a manifestation of onchocerciasis, we will considerably improve the accuracy of the overall onchocerciasis disease burden, which is currently underestimated. Hopefully, this will lead to increased interest and funding for onchocerciasis research and control interventions, notably the implementation of more effective elimination measures and treatment and support for affected individuals and their families.


Assuntos
Epilepsia , Síndrome do Cabeceio , Oncocercose , Humanos , Oncocercose/complicações , Oncocercose/diagnóstico , Oncocercose/epidemiologia , Síndrome do Cabeceio/epidemiologia , Epilepsia/epidemiologia , Epilepsia/etiologia , Saúde Pública , Efeitos Psicossociais da Doença , Prevalência
5.
Exp Oncol ; 45(3): 297-311, 2023 12 28.
Artigo em Inglês | MEDLINE | ID: mdl-38186025

RESUMO

BACKGROUND: Glioblastoma (GBM) is the most frequent primary malignant CNS tumor. Deficient mismatch repair (dMMR) is associated with better prognosis and is a biomarker for immunotherapy. Evaluation of MMR by immunohistochemistry (IHC) is accessible, cost effective, sensitive, and specific. AIM: Our objective was to investigate MMR proteins in adult GBM patients. MATERIALS AND METHODS: We retrospectively analyzed 68 GBM samples to evaluate the proficiency of MMR genes expression assessed by IHC. Clinicopathologic and molecular features were compared in proficient (pMMR) or dMMR. RESULTS: 10 (14.7%) samples showed dMMR, and the most frequent was MSH6 (100%) followed by MSH2, PMS2, and MLH1. We observed heterogeneous expression of dMMR in 5 GBMs. The median overall survival did not differ between pMMR (19.8 months; 0.2-30) and dMMR (16.9 months; 6.4-27.5) (p = 0.31). We observed a significantly higher overall survival associated with gross total resection compared to subtotal resection or biopsy (30.7 vs. 13.6 months, p = 0.02) and MGMT methylated status (29.6 vs. 19.8 months, p = 0.049). At the analysis time, 10 patients were still alive, all in the pMMR group. CONCLUSIONS: Our data demonstrated dMMR phenotype assessed by IHC in an expressive portion of GBM patients, however without significant impact on overall survival.


Assuntos
Glioblastoma , Adulto , Humanos , Glioblastoma/genética , Imuno-Histoquímica , Brasil , Reparo de Erro de Pareamento de DNA/genética , Estudos Retrospectivos
7.
J Trace Elem Med Biol ; 68: 126848, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34479099

RESUMO

BACKGROUND: Thallium (Tl) is a toxic metalloid and an emerging pollutant due to electronic devices and dispersal nearby base-metal mining. Therefore, Tl poses a threat to human health and especially the long-term impact on younger individuals exposed is still unknown. This study aimed to evaluate the toxic effects of thallium acetate in C. elegans in early larval stages, considering physiological and behavioral endpoints, as well as the Tl absorption and bioaccumulation. METHODS: Caenorhabditis elegans (C. elegans) was exposed to Thallium acetate (50, 100, 150, 200, 250, 500, and 1000 µM) in the L1 larval stage, with the purpose to observe the toxic effects invoked until adulthood. Transgenic worms strains were transported GFP, reporters to DAF-16 and were used to verify the antioxidant response. ICP-MS quantified total Tl+ concentration to evidence Tl uptake and bioaccumulation. RESULTS: Thallium acetate caused a significant reduction in the number of living worms (p < 0.0001 in 100-1000 µM), a delay in larval development (p < 0.01; p < 0.001 and p < 0.0001 in 100-1000 µM) through the larval stages, and egg production in the worm's uterus was reduced. Thallium acetate also induced behavioral changes. Additionally, thallium acetate activated antioxidant pathway responses in C. elegans by translocating the DAF-16 transcription factor and activation of SOD-3::GFP expression. The Tl+ quantification in worms showed its absorption in the L1 larval stage and bioaccumulation in the body after development. CONCLUSIONS: Thallium acetate reduced survival, delayed development, caused behavioral changes, induced responses inherent to oxidative stress, and serious damage to the worm's reproduction. In addition, C. elegans absorbed and bioaccumulated Tl+. Together, our results highlight the impacts of Tl+ exposure in the early stages of life, even for a short period.


Assuntos
Compostos Organometálicos/toxicidade , Testes de Toxicidade Aguda , Animais , Antioxidantes , Caenorhabditis elegans , Larva , Nematoides , Tálio/toxicidade
8.
AJNR Am J Neuroradiol ; 42(3): 590-596, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33478945

RESUMO

Galactosemia is a rare genetic condition caused by mutation of enzymes involved in galactose and glucose metabolism. The varying clinical spectrum reflects the genetic complexity of this entity manifesting as acute neonatal toxicity syndrome, requiring prompt diagnosis and treatment, to more insidious clinical scenarios as observed in the subacute and chronic presentations. The current literature predominantly focuses on the long-standing sequelae of this disease. The purpose of this multicenter clinical report comprising 17 patients with galactosemia is to highlight the MR imaging patterns encompassing the whole spectrum of galactosemia, emphasizing the 3 main clinical subtypes: 1) acute neonatal presentation, with predominant white matter edema; 2) subacute clinical onset with a new finding called the "double cap sign"; and 3) a chronic phase of the disease with heterogeneous imaging findings. The knowledge of these different patterns together with MR spectroscopy and the clinical presentation may help in prioritizing galactosemia over other neonatal metabolic diseases and prevent possible complications.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/patologia , Galactosemias/diagnóstico por imagem , Galactosemias/patologia , Adolescente , Criança , Pré-Escolar , Progressão da Doença , Feminino , Humanos , Lactente , Recém-Nascido , Masculino
10.
11.
Front Neurosci ; 14: 390, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32508561

RESUMO

Background: Recently, the ketogenic diet has been proposed as an adjunct treatment for a range of medical conditions including weight loss, diabetes, cancer, and neurodegenerative diseases. Because malignant CNS tumors are highly dependent on glucose, the use of a ketogenic diet as an adjunct therapy is currently being explored. This case series summarizes our experience implementing a ketogenic diet for patients with CNS malignancies. Methods: Patients diagnosed with CNS malignancies following a ketogenic diet were identified between 2015 and 2017. Malignancies included confirmed diagnoses of glioblastoma (GBM), astrocytoma, or oligodendroglioma. With guidance from a registered dietitian, ketone levels, glucose levels, and weight were regularly collected for several patients along with patient-reported symptoms and adverse effects. Interested patients were asked to follow a 3:1 ketogenic diet for 120 days. The ketogenic diet is a high-fat, moderate protein, and very low carbohydrate diet, where patients limited carbohydrate intake to ≤20 g per day. Brain imaging was reviewed. A series of descriptive analyses were conducted. Results: The ketogenic diet was initiated in 12 patients of which 8 patients contributed data on their blood glucose and ketone levels. The majority of patients were male (n = 10) with a median age of 45 (range 32-62). Diagnoses included GBM (n = 6), grade 2/3 astrocytomas (n = 5) and one patient with a grade 2 spinal cord astrocytoma. Ten of the 12 patients were receiving concurrent treatment; two received supportive care only. The majority of patients with evaluable data (n = 8) maintained ketone levels above 0.5 mM for the duration of 120-day period. Ketone levels generally increased from baseline while glucose levels and BMI decreased. Overall, patients reported improved symptoms over the course of the diet. Imaging also suggested improved disease control and reduction in vasogenic edema. Conclusion: Taking advantage of a tumor's metabolic inflexibility can have a positive impact on patients, particularly those with CNS malignancies. More structured and statistically planned clinical trials are needed to determine the margin of impact of a ketogenic diet.

12.
AJNR Am J Neuroradiol ; 40(4): 614-619, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30846435

RESUMO

BACKGROUND AND PURPOSE: Gadolinium SWI is MR imaging that has recently been reported to be effective in the evaluation of several neurologic disorders, including demyelinating diseases. Our aim was to analyze the accuracy of gadolinium SWI for detecting the imaging evidence of active inflammation on MS plaques when a BBB dysfunction is demonstrated by a focal gadolinium-enhanced lesion and to compare this technique with gadolinium-enhanced T1 spin-echo and T1 spin-echo with magnetization transfer contrast. MATERIALS AND METHODS: MR imaging studies of 103 patients (170 examinations) were performed using a 1.5T scanner. Two neuroradiologists scrutinized signal abnormalities of the demyelinating plaques on gadolinium SWI and compared them with gadolinium T1 before and after an additional magnetization transfer pulse. Interrater agreement was evaluated among gadolinium T1 magnetization transfer contrast, gadolinium SWI, and gadolinium T1 spin-echo using the κ coefficient. The T1 magnetization transfer contrast sequence was adopted as the criterion standard in this cohort. Thus, the sensitivity, specificity, positive predictive value, and negative predictive value were calculated for gadolinium T1 spin-echo and gadolinium SWI sequences. RESULTS: Differences in BBB dysfunction were evident among gadolinium SWI, gadolinium T1 spin-echo, and gadolinium T1 magnetization transfer contrast. Gadolinium T1 magnetization transfer contrast demonstrated the highest number of active demyelinating plaques. Gadolinium SWI was highly correlated with gadolinium T1 magnetization transfer contrast in depicting acute demyelinating plaques (κ coefficient = 0.860; sensitivity = 0.837), and these techniques provided better performance compared with gadolinium T1 spin-echo (κ coefficient = 0.78; sensitivity = 0.645). CONCLUSIONS: Gadolinium SWI was able to better detect BBB dysfunction in MS plaques and had a better performance than gadolinium T1 spin-echo. Increasing SWI sequence applications in clinical practice can improve our knowledge of MS, likely allowing the addition of BBB dysfunction analysis to the striking findings of the previously reported central vein sign.


Assuntos
Encéfalo/diagnóstico por imagem , Gadolínio , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla Recidivante-Remitente/diagnóstico por imagem , Neuroimagem/métodos , Adolescente , Adulto , Algoritmos , Barreira Hematoencefálica/diagnóstico por imagem , Barreira Hematoencefálica/patologia , Encéfalo/patologia , Estudos de Coortes , Meios de Contraste , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/patologia , Estudos Retrospectivos , Sensibilidade e Especificidade , Adulto Jovem
13.
Clin Exp Immunol ; 196(3): 374-382, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30697694

RESUMO

Infective endocarditis (IE) is the cardiac disease with the highest rates of mortality. New biomarkers that are able to identify patients at risk for death are required to improve patient management and outcome. This study aims to investigate if cytokines, chemokines and growth factors measured at IE diagnosis can predict mortality. Patients with definite IE, according to the Duke's modified criteria, were included. Using high-performance Luminex assay, 27 different cytokines, chemokines and growth factors were analyzed. Machine learning techniques were used for the prediction of death and subsequently creating a decision tree, in which the cytokines, chemokines and growth factors were analyzed together with C-reactive protein (CRP). Sixty-nine patients were included, 41 (59%) male, median age 54 [interquartile range (IQR) = 41-65 years] and median time between onset of the symptoms and diagnosis was 12 days (IQR = 5-30 days). The in-hospital mortality was 26% (n = 18). Proinflammatory cytokines interkeukin (IL)-15 and C-C motif chemokine ligand (CCL4) were found to predict death, adding value to CRP levels. The decision tree predicted correctly the outcome of 91% of the patients at hospital admission. The high-risk group, defined as CRP ≥ 72 mg/dL, IL-15 ≥ 5·6 fg/ml and CCL4 ≥ 6·35 fg/ml had an 88% in-hospital mortality rate, whereas the patients classified as low-risk had a mortality rate of 8% (P = < 0·001). Cytokines IL-15 and CCL4 were predictors of mortality in IE, adding prognostic value beyond that provided by CRP levels. Assessment of cytokines has potential value for clinical risk stratification and monitoring in IE patients.


Assuntos
Quimiocina CCL4/metabolismo , Endocardite/diagnóstico , Interleucina-15/metabolismo , Adulto , Idoso , Biomarcadores/metabolismo , Proteína C-Reativa/metabolismo , Tomada de Decisões Assistida por Computador , Endocardite/imunologia , Endocardite/mortalidade , Feminino , Mortalidade Hospitalar , Humanos , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco
14.
Occup Med (Lond) ; 68(9): 641-643, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30496499

RESUMO

BACKGROUND: Cassia angustifolia, or senna, is a plant belonging to the Fabaceae family, widely used as a laxative and as a colouring agent in hair dyes. Senna is rarely reported as an occupational allergic sensitizer in the current literature. AIMS: To describe the case and diagnostic approach of a suspected occupational senna allergy. CASE REPORT: A male phytopharmaceutical warehouse worker reported bronchial, conjunctival and nasal symptoms immediately upon exposure to senna. We were able to document in vitro sensitization, finding IgE-binding proteins in senna, and in vivo sensitization through positive skin tests and conjunctival provocation test. CONCLUSION: Our study confirms that senna may cause occupational rhinoconjunctivitis symptoms with an IgE-dependent mechanism and is the first to confirm it through specific conjunctival provocation test.


Assuntos
Exposição Ocupacional/efeitos adversos , Extrato de Senna/efeitos adversos , Testes de Provocação Brônquica/métodos , Conjuntivite Alérgica/etiologia , Humanos , Hipersensibilidade/complicações , Imunoglobulina E/análise , Imunoglobulina E/sangue , Masculino , Pessoa de Meia-Idade , Senna (Planta)/efeitos adversos
15.
Biomed Res Int ; 2018: 3254094, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30310816

RESUMO

Different subsets of asthma patients may be recognized according to the exposure trigger and the frequency and severity of clinical signs and symptoms. Regarding the exposure trigger, generally asthma can be classified as allergic (or atopic) and nonallergic (or nonatopic). Allergic and nonallergic asthma are distinguished by the presence or absence of clinical allergic reaction and in vitro IgE response to specific aeroallergens. The mechanisms of allergic asthma have been extensively studied with major advances in the last two decades. Nonallergic asthma is characterized by its apparent independence from allergen exposure and sensitization and a higher degree of severity, but little is known regarding the underlying mechanisms. Clinically, allergic and nonallergic asthma are virtually indistinguishable in exacerbations, although exacerbation following allergen exposure is typical of allergic asthma. Although they both show several distinct clinical phenotypes and different biomarkers, there are no ideal biomarkers to stratify asthma phenotypes and guide therapy in clinical practice. Nevertheless, some biomarkers may be helpful to select subsets of atopic patients which might benefit from biologic agents, such as omalizumab. Patients with severe asthma, uncontrolled besides optimal treatment, notwithstanding nonatopic, may also benefit from omalizumab therapy, although currently there are no randomized double-blind placebo controlled clinical trials to support this suggestion. However, omalizumab discontinuation according to each patient's response to therapy and pharmacoeconomical analysis are questions that remain to be answered.


Assuntos
Antiasmáticos/uso terapêutico , Asma/tratamento farmacológico , Omalizumab/uso terapêutico , Asma/fisiopatologia , Humanos , Fenótipo
16.
Environ Monit Assess ; 190(6): 320, 2018 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-29717352

RESUMO

The presence of micropollutants that include endocrine-disrupting compounds (EDC) in aquatic environments is currently one of the most relevant aspects of water quality due to their adverse effects on aquatic organisms and human health. From the several categories of EDC, 17ß-estradiol (E2) is a natural hormone, which is prevalent in vertebrates, associated with the female reproductive system and maintenance of the sexual characters. 17α-Ethinylestradiol (EE2) is a synthetic hormone produced from the natural hormone E2 and is an essential component of oral contraceptives. These compounds are susceptible to bioconcentration and have high potential to bioaccumulation. Wastewater treatment plants are the main point source of E2 and EE2 into aquatic environments, but conventional wastewater treatment systems are not specifically designed for steroid removal. To overcome this problem, biological tertiary treatment may be a solution for the removal of emergent pollutants such as E2 and EE2. The main purpose of the present study is to provide a solution based on the optimization of a rotating biological contactor system to remove estrogens, specifically E2 and EE2, and to quantify their removal efficiency on different matrices, namely real wastewater and different synthetic wastewaters. All assays presented viable removal efficiencies for compound E2 with values always above 50%; real wastewater yielded the highest removal efficiencies. EE2 removal had better removal efficiencies with synthetic wastewater as feed solution, with removals above 15%, whereas the removal efficiency with real wastewater was inexistent.


Assuntos
Estradiol/análise , Etinilestradiol/análise , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/química , Poluentes Químicos da Água/análise , Disruptores Endócrinos/análise , Monitoramento Ambiental , Estrogênios/análise , Humanos
17.
AJNR Am J Neuroradiol ; 38(10): 1899-1904, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28705817

RESUMO

Multinodular and vacuolating neuronal tumor of the cerebrum is a recently reported benign, mixed glial neuronal lesion that is included in the 2016 updated World Health Organization classification of brain neoplasms as a unique cytoarchitectural pattern of gangliocytoma. We report 33 cases of presumed multinodular and vacuolating neuronal tumor of the cerebrum that exhibit a remarkably similar pattern of imaging findings consisting of a subcortical cluster of nodular lesions located on the inner surface of an otherwise normal-appearing cortex, principally within the deep cortical ribbon and superficial subcortical white matter, which is hyperintense on FLAIR. Only 4 of our cases are biopsy-proven because most were asymptomatic and incidentally discovered. The remaining were followed for a minimum of 24 months (mean, 3 years) without interval change. We demonstrate that these are benign, nonaggressive lesions that do not require biopsy in asymptomatic patients and behave more like a malformative process than a true neoplasm.


Assuntos
Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Ganglioneuroma/diagnóstico por imagem , Ganglioneuroma/patologia , Adulto , Cérebro , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Neurônios/patologia , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
18.
Eur Ann Allergy Clin Immunol ; 49(3): 114-121, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28497674

RESUMO

SUMMARY: A cross-cultural translation of the Vespid Allergy Quality of Life Questionnaire (VQLQ) to the Portuguese population (VQLQ-P) was performed, assessing its applicability in wasp and in non-beekeeper bee venom allergic patients. Additionally, we evaluated a Visual Analogue Scale (VAS) to estimate hymenoptera allergy interference with daily life. Methods. Cross-cultural translation was performed according to recommendations. The final VQLQ-P version, the Expectation of Outcome questionnaire (EoQ), EQ-5D and VAS were applied to wasp (n = 19) and non-beekeeper bee venom allergic patients (n = 30). Results. VQLQ-P significantly correlated with EoQ, (r = 0.76, p < 0.01), EQ-5D (usual activities and anxiety / depression dimensions) and VAS, with a good internal consistency (Cronbach α = 0.88) in wasp allergic individuals. VQLQ-P and EoQ correlation was also high (r = 0.67, p < 0.01) in bee allergy. Conclusion. The VQLQ-P is a valuable tool to evaluate quality of life impairment in Portuguese hymenoptera venom allergic individuals.


Assuntos
Hipersensibilidade/psicologia , Qualidade de Vida , Venenos de Vespas/imunologia , Adulto , Dessensibilização Imunológica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Tradução
19.
J Endocrinol Invest ; 40(8): 823-829, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28276007

RESUMO

Herpesviruses have been associated with various human malignancies and with thyroid autoimmunity. Aiming to investigate the presence of these viruses in thyroid nodules, we analyzed serum and thyroid tissue from 183 patients (83 benign and 100 malignant thyroid nodules). We also obtained 104 normal thyroid tissues extracted from the contralateral lobe of these patients. We used ELISA to screen the serology of all patients and a real-time quantitative PCR to analyze thyroid tissue viral load in antibody-positive patients. In addition, the presence of herpesviruses was tested by histological analysis in 20 EBV-positive tissues using the expression of LMP-1 by immunohistochemistry (IHC) and EBER by in situ hybridization (ISH). There was no evidence of HSV-2 or CMV DNA, but we found EBV DNA sequences in 29 (16%) thyroid tissue samples. We also found 7 positive EBV cases out of 104 normal tissues. Viral load was higher in tumors than in their respective normal tissues (p = 0.0002). ISH analysis revealed EBER expression in 11 out of 20 (52%) EBV-positive tissues, mostly in malignant cases (8/11, 73%). The presence of high EBV copy numbers in thyroid tumors and the expression of EBER only in malignant cases suggest an association between EBV and thyroid malignancies. However, we did not find any association between the presence of EBV and/or its viral load and any clinical or pathological tumor feature. Further studies aiming to clarify the mechanisms of EBV infection in thyroid cells are necessary to support a possible role in the development of thyroid cancer.


Assuntos
Infecções por Vírus Epstein-Barr/complicações , Herpesvirus Humano 4/patogenicidade , Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/epidemiologia , Brasil/epidemiologia , Estudos de Casos e Controles , DNA Viral/genética , Infecções por Vírus Epstein-Barr/virologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Glândula Tireoide/virologia , Neoplasias da Glândula Tireoide/virologia
20.
Braz J Med Biol Res ; 50(3): e5848, 2017 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-28273210

RESUMO

This study presents the characterization of an X-ray irradiator through dosimetric tests, which confirms the actual dose rate that small animals and cells will be exposed to during radiobiological experiments. We evaluated the linearity, consistency, repeatability, and dose distribution in the positions in which the animals or cells are placed during irradiation. In addition, we evaluated the performance of the X-ray tube (voltage and tube operating current), the radiometric survey (leakage radiation) and safety devices. The irradiator default setting was established as 160 kV and 25 mA. Tests showed that the dose rate was linear overtime (R2=1) and remained stable for long (constant) and short (repeatability) intervals between readings. The mean dose rate inside the animal cages was 1.27±0.06 Gy/min with a uniform beam of 95.40% (above the minimum threshold guaranteed by the manufacturer). The mean dose rate inside the cell plates was 0.92±0.19 Gy/min. The dose rate dependence with tube voltage and current presented a quadratic and linear relationship, respectively. There was no observed mechanical failure during evaluation of the irradiator safety devices and the radiometric survey obtained a maximum ambient equivalent dose rate of 0.26 mSv/h, which exempts it from the radiological protection requirements of the International Atomic Energy Agency. The irradiator characterization enables us to perform radiobiological experiments, and assists or even replaces traditional therapy equipment (e.g., linear accelerators) for cells and small animal irradiation, especially in early research stages.


Assuntos
Doses de Radiação , Radiometria/instrumentação , Animais , Calibragem , Desenho de Equipamento , Aceleradores de Partículas , Radiometria/métodos , Raios X
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