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1.
Braz J Med Biol Res ; 56: e12713, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37493771

RESUMO

Mesenchymal stromal/stem cells stem (MSC) have been widely studied due to their great potential for application in tissue engineering and regenerative and translational medicine. In MSC-based therapy for human diseases, cell proliferation is required to obtain a large and adequate number of cells to ensure therapeutic efficacy. During in vitro culture, cells are under an artificial environment and manipulative stress that can affect genetic stability. Several regulatory agencies have established guidelines to ensure greater safety in cell-based regenerative and translational medicine, but there is no specific definition about the maximum number of passages that ensure the lowest possible risk in MSC-based regenerative medicine. In this context, the aim of this study was to analyze DNA damage and chromosome alterations in adipose-derived mesenchymal stromal cells (ADMSC) until the eleventh passage and to provide additional subsidies to regulatory agencies related to number of passages in these cells. Thus, two methods in genetic toxicology were adopted: comet assay and micronucleus test. The comet assay results showed an increase in DNA damage from the fifth passage onwards. The micronucleus test showed a statistically significant increase of micronucleus from the seventh passage onwards, indicating a possible mutagenic effect associated with the increase in the number of passages. Based on these results, it is important to emphasize the need to assess genetic toxicology and inclusion of new guidelines by regulatory agencies to guarantee the safety of MSC-based therapies for human diseases.


Assuntos
Células-Tronco Mesenquimais , Humanos , Engenharia Tecidual , Instabilidade Genômica , Proliferação de Células , Mutagênese , Diferenciação Celular , Células Estromais
2.
Nanotechnology ; 34(43)2023 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-37473751

RESUMO

Improving the thermal resilience of magnetic tunnel junctions (MTJs) broadens their applicability as sensing devices and is necessary to ensure their operation under harsh environments. In this work, we are address the impact of temperature on the degradation of the magnetic reference in field sensor stacks based on MgO-MTJs. Our study starts by simple MnIr/CoFe bilayers to gather enough insights into the role of critical morphological and magnetic parameters and their impact in the temperature dependent behavior. The exchange bias coupling field (Hex), coercive field (Hc), and blocking temperature (Tb) distribution are tuned, combining tailored growth conditions of the antiferromagnet and different buffer layer materials and stackings. This is achieved by a unique combination of ion beam deposition and magnetron sputtering, without vaccum break. Then, the work then extends beyond bilayers into more complex state-of-the-art MgO MTJ stacks as those employed in commercial sensing applications. We systematically address their characteristic fields, such as the width of the antiferromagnetic coupling plateau ΔH, and study their dependence on temperature. Although, [Ta/CuN] buffers showed higher key performance indications (e.g.Hex) at room temperature in both bilayers and MTJs, [Ta/Ru] buffers showed an overall wider ΔHup to 200 °C, more suitable to push high temperature operations. This result highlights the importance of properly design a suitable buffer layer system and addressing the complete MTJ behavior as function of temperature, to deliver the best stacking design with highest resilience to high temperature environments.

3.
Braz J Microbiol ; 54(2): 1239-1249, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36877446

RESUMO

Crohn's disease (CD) is a chronic granulomatous inflammatory bowel disease with no fully understood etiology and cure. Mycobacterium avium subspecies paratuberculosis (MAP), the etiologic agent of paratuberculosis, is also isolated from samples from human patients with CD. Paratuberculosis is characterized by persistent diarrhea and progressive weight loss and primarily affects ruminants, which eliminate the agent via feces and milk. The involvement of MAP in the pathogenesis of CD and other intestinal diseases is unclear. Thus, the present study aimed to analyze immunological, socioepidemiological, biochemical, and therapeutic variables that may be related to the occurrence of MAP in blood samples and CD patients. The sampling was random, and the population of origin was the patients from the Bowel Outpatient Clinic of the Alpha Institute of Gastroenterology (IAG), Hospital das Clínicas, Universidade Federal de Minas Gerais (HC-UFMG). Blood samples were collected from 20 patients with CD, eight with ulcerative rectocolitis (UCR), and 10 control patients without inflammatory bowel diseases. Samples were subjected to real-time PCR for detection of MAP DNA, oxidative stress analyses, and socioepidemiological variables. MAP was detected in 10 (26.3%) of the patients, seven (70%) were CD patients, 2 (20%) were URC patients, and one (10%) was a non-IBD patient. MAP was found more frequently among CD patients, but not restricted to CD patients. The presence of MAP in the blood of these patients occurred simultaneously with an inflammatory response with an increase in neutrophils and significant alterations in the production of antioxidant enzymes such as catalase and GST.


Assuntos
Doença de Crohn , Doenças Inflamatórias Intestinais , Mycobacterium avium subsp. paratuberculosis , Paratuberculose , Animais , Humanos , Doença de Crohn/diagnóstico , Doença de Crohn/tratamento farmacológico , Doença de Crohn/microbiologia , Paratuberculose/microbiologia , Mycobacterium avium subsp. paratuberculosis/genética , Doenças Inflamatórias Intestinais/microbiologia , Intestinos
4.
Angiogenesis ; 26(3): 365-384, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36631598

RESUMO

The Feline Leukemia Virus Subgroup C Receptor 1a (FLVCR1a) is a transmembrane heme exporter essential for embryonic vascular development. However, the exact role of FLVCR1a during blood vessel development remains largely undefined. Here, we show that FLVCR1a is highly expressed in angiogenic endothelial cells (ECs) compared to quiescent ECs. Consistently, ECs lacking FLVCR1a give rise to structurally and functionally abnormal vascular networks in multiple models of developmental and pathologic angiogenesis. Firstly, zebrafish embryos without FLVCR1a displayed defective intersegmental vessels formation. Furthermore, endothelial-specific Flvcr1a targeting in mice led to a reduced radial expansion of the retinal vasculature associated to decreased EC proliferation. Moreover, Flvcr1a null retinas showed defective vascular organization and loose attachment of pericytes. Finally, adult neo-angiogenesis is severely affected in murine models of tumor angiogenesis. Tumor blood vessels lacking Flvcr1a were disorganized and dysfunctional. Collectively, our results demonstrate the critical role of FLVCR1a as a regulator of developmental and pathological angiogenesis identifying FLVCR1a as a potential therapeutic target in human diseases characterized by aberrant neovascularization.


Assuntos
Células Endoteliais , Neoplasias , Adulto , Animais , Humanos , Camundongos , Células Endoteliais/fisiologia , Neovascularização Patológica/genética , Neovascularização Fisiológica/genética , Peixe-Zebra
5.
Braz. j. med. biol. res ; 56: e12713, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1447680

RESUMO

Mesenchymal stromal/stem cells stem (MSC) have been widely studied due to their great potential for application in tissue engineering and regenerative and translational medicine. In MSC-based therapy for human diseases, cell proliferation is required to obtain a large and adequate number of cells to ensure therapeutic efficacy. During in vitro culture, cells are under an artificial environment and manipulative stress that can affect genetic stability. Several regulatory agencies have established guidelines to ensure greater safety in cell-based regenerative and translational medicine, but there is no specific definition about the maximum number of passages that ensure the lowest possible risk in MSC-based regenerative medicine. In this context, the aim of this study was to analyze DNA damage and chromosome alterations in adipose-derived mesenchymal stromal cells (ADMSC) until the eleventh passage and to provide additional subsidies to regulatory agencies related to number of passages in these cells. Thus, two methods in genetic toxicology were adopted: comet assay and micronucleus test. The comet assay results showed an increase in DNA damage from the fifth passage onwards. The micronucleus test showed a statistically significant increase of micronucleus from the seventh passage onwards, indicating a possible mutagenic effect associated with the increase in the number of passages. Based on these results, it is important to emphasize the need to assess genetic toxicology and inclusion of new guidelines by regulatory agencies to guarantee the safety of MSC-based therapies for human diseases.

6.
Climacteric ; 24(3): 305-312, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33709858

RESUMO

BACKGROUND: Menopausal transition is a physiological process encompassing hormonal and body changes that impact women's health and life quality. This period may be characterized by the Stages of Reproductive Aging Workshop (STRAW + 10) criteria using menstrual patterns. Use of the STRAW + 10 is uncertain in HIV infection. We aimed to characterize menopausal transition in women with HIV (WWH) using the STRAW + 10 criteria, hormonal measures and menopause symptoms. METHODS: We performed a cross-sectional study, nested to the HIV-Infected Women's Cohort, in Rio de Janeiro, Brazil. Eligible women included those aged 30 years or older, without clinical or surgical menopause, hormonal contraception, replacement therapy and ovarian disorders. We conducted face-to-face interviews and collected blood samples for follicle stimulating hormone (FSH) and estradiol measures. RESULTS: We enrolled 328 WWH (28.3% of women in the cohort). The distribution of age, hormonal levels and reported symptoms per each STRAW + 10 stage was consistent with the expected distribution in the menopausal transition. Age and FSH significantly increased and estradiol decreased from stage -2 (7 + days of menstrual delay) to stage +2 (8 + years of amenorrhea). CONCLUSIONS: The present results support use of the STRAW + 10 to characterize the menopausal transition of WWH with good clinical and immunological control.


Assuntos
Envelhecimento/fisiologia , Infecções por HIV/fisiopatologia , HIV , Menopausa/fisiologia , Adulto , Brasil , Estudos de Coortes , Estudos Transversais , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Humanos , Pessoa de Meia-Idade
7.
J Mech Behav Biomed Mater ; 118: 104451, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33730640

RESUMO

The titanium implant/zirconia abutment interface can suffer failure upon mechanical and biological issues, ultimately leading to the loss of the artificial tooth. The study of the effect of the organic compounds present in saliva on the tribological behavior of these systems is of utmost importance to understand the failure mechanisms and better mimic the in vivo conditions. The aim of the present work is to evaluate the effect of the addition of albumin, urea, lysozyme and mucin to artificial saliva, on the triboactivity of Ti6Al4V/zirconia pair commonly used in dental implants and then, compare the results with those obtained with human saliva. The solutions' viscosity was measured and the adsorption of the different biomolecules to both Ti6Al4V and zirconia was accessed. Tribological tests were performed using Ti6Al4V balls sliding on zirconia plates inside of a corrosion cell. Friction and wear coefficients were determined, and the open circuit potential (OCP) was monitored during the tests. Also, the wear mechanisms were identified. The presence of mucin in the artificial lubricant led to the lowest wear coefficients. The main wear mechanism was abrasion, independently of the used lubricant. Adhesive wear was observed for the systems without mucin. Tribocorrosion activity and wear coefficient were lower in the presence of mucin. None of the studied artificial lubricants mimicked the effect of human saliva (HS) on the tribological behavior of the studied pair since this lubricant led to the lowest friction coefficient and highest corrosion activity.


Assuntos
Implantes Dentários , Titânio , Albuminas , Ligas , Corrosão , Humanos , Teste de Materiais , Mucinas , Muramidase , Propriedades de Superfície , Ureia , Zircônio
8.
HIV Med ; 22(6): 445-456, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33529485

RESUMO

OBJECTIVES: We aimed to evaluate the accuracy of serological biomarkers for non-alcoholic fatty liver disease (NAFLD) and advanced fibrosis (METAVIR-F3F4) in HIV mono-infected individuals. METHODS: In all, 674 participants from the PROSPEC-HIV study (NCT02542020), who had blood sample tests and transient elastography (TE) performed on the same day, were eligible. Exclusion criteria were viral hepatitis co-infection (n = 90), abusive alcohol intake (n = 61), missing data (n = 47) or unreliable TE (n = 39). NAFLD was defined by controlled attenuation parameter ≥ 248 dB/m and advanced fibrosis by liver stiffness measurement ≥ 8.7 kPa with M probe or ≥ 7.2 kPa with XL probe. Biomarkers for NAFLD [Steato-ELSA, Fatty Liver Index (FLI), Hepatic Steatosis Index (HSI), NAFLD-Liver Fat Score (NAFLD-LFS)] and fibrosis [Fibrosis-4 score (FIB-4), Aspartate-to-Platelet Ratio Index (APRI) and NAFLD Fibrosis Score (NFS)] were calculated. RESULTS: A total of 437 patients [57% female, age = 44 (interquartile range: 35-52) years, body mass index (BMI) = 26.1 (23.4-29.3) kg/m2 , CD4 = 660 (427-901) cells/µL] were included. The prevalence [95% confidence interval (CI)] of NAFLD and advanced fibrosis were 38.2% (33.8-42.9) and 10.5% (8.0-13.8), respectively. The areas (95% CI) under the receiver operator curve (AUROCs) for diagnosis of NAFLD were 0.854 (0.818-0.889), 0.840 (0.804-0.877), 0.805 (0.762-0.847) and 0.793 (0.750-0.836) for Steato-ELSA, FLI, HSI and NAFLD-LFS (P < 0.001), respectively. All tests yielded satisfactory sensitivities, specificities and negative predictive values (NPVs). The AUROCs (95% CI) for diagnosis of advanced fibrosis were 0.736 (0.659-0.814), 0.700 (0.614-0.7851) and 0.795 (0.726-0.864) for FIB-4, APRI and NFS (P = 0.077), respectively. These tests yielded high specificities and negative predictive values (NPVs) > 90%. CONCLUSION: Biomarkers for NAFLD had a good accuracy and those for fibrosis had high specificities and NPVs. These tests should be integrated to HIV care to detect NAFLD and to exclude advanced liver fibrosis.


Assuntos
Técnicas de Imagem por Elasticidade , Infecções por HIV , Hepatopatia Gordurosa não Alcoólica , Adulto , Biomarcadores , Biópsia , Feminino , Infecções por HIV/complicações , Infecções por HIV/patologia , Humanos , Fígado/patologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/epidemiologia , Masculino , Hepatopatia Gordurosa não Alcoólica/diagnóstico
9.
Med Oral Patol Oral Cir Bucal ; 26(3): e334-e340, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33340085

RESUMO

BACKGROUND: Metallothioneins (MTs) gene polymorphisms have been associated with the ability of free radical scavenging and detoxification of heavy metals leading to cancer development. Our aim was to revisit, in a Brazilian population, single-nucleotide polymorphisms (SNPs) of the MT gene family previously associated with oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: A case-control investigation with 28 OSCC patients and 45 controls was conducted, using conventional risk factors (tobacco use and alcohol consumption) as covariates. SNPs genotyping for rs8052334 (MT1B), rs964372 (MT1B), and rs1610216 (MT2A) was performed by PCR-RFLP, and SNPs for rs11076161 (MT1A) were analyzed by TaqMan assay. RESULTS: The only SNP associated with increased risk for OSCC was the MT-1A AA genotype (OR = 4.7; p = 0.01). We have also evidenced for the first time a significant linkage disequilibrium between the SNPs of MT-2A and MT-1A in this population with the highest frequency (30%) of the unfavorable haplotype G/A/C/T (rs1610216 / rs11076161 / rs964372 / rs8052334) of MT gene polymorphisms (OR = 6.2; p = 0.04). Interestingly, after removing the effects of conventional risk factors, we have uncovered the significance of the AA genotype of the rs11076161 with increased odds of 19-fold higher towards OSCC development. CONCLUSIONS: This is the first demonstration that a significant linkage disequilibrium among gene polymorphisms of the MT family may affect susceptibility to oral cancer, which is conditioned by the G/A/C/T haplotype (rs1610216/rs11076161/rs964372/ rs8052334) and the MT-1A gene polymorphism has a potential clinical utility for the OSCC risk assessment.


Assuntos
Carcinoma de Células Escamosas , Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Brasil , Carcinoma de Células Escamosas/genética , Estudos de Casos e Controles , Predisposição Genética para Doença , Genótipo , Humanos , Metalotioneína/genética , Neoplasias Bucais/genética , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Carcinoma de Células Escamosas de Cabeça e Pescoço
10.
J Autoimmun ; 117: 102574, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33307312

RESUMO

The T-cell receptor (TCR) is a highly polymorphic surface receptor that allows T-cells to recognize antigenic peptides presented on the major histocompatibility complex (MHC). Changes in the TCR repertoire have been observed in several autoimmune conditions, and these changes are suggested to predispose autoimmunity. Multiple lines of evidence have implied an important role for T-cells in the pathogenesis of Systemic Sclerosis (SSc), a complex autoimmune disease. One of the major questions regarding the roles of T-cells is whether expansion and activation of T-cells observed in the diseases pathogenesis is antigen driven. To investigate the temporal TCR repertoire dynamics in SSc, we performed high-throughput sequencing of CD4+ and CD8+ TCRß chains on longitudinal samples obtained from four SSc patients collected over a minimum of two years. Repertoire overlap analysis revealed that samples taken from the same individual over time shared a high number of TCRß sequences, indicating a clear temporal persistence of the TCRß repertoire in CD4+ as well as CD8+ T-cells. Moreover, the TCRßs that were found with a high frequency at one time point were also found with a high frequency at the other time points (even after almost four years), showing that frequencies of dominant TCRßs are largely consistent over time. We also show that TCRß generation probability and observed TCR frequency are not related in SSc samples, showing that clonal expansion and persistence of TCRßs is caused by antigenic selection rather than convergent recombination. Moreover, we demonstrate that TCRß diversity is lower in CD4+ and CD8+ T-cells from SSc patients compared with memory T-cells from healthy individuals, as SSc TCRß repertoires are largely dominated by clonally expanded persistent TCRß sequences. Lastly, using "Grouping of Lymphocyte Interactions by Paratope Hotspots" (GLIPH2), we identify clusters of TCRß sequences with homologous sequences that potentially recognize the same antigens and contain TCRßs that are persist in SSc patients. In conclusion, our results show that CD4+ and CD8+ T-cells are highly persistent in SSc patients over time, and this persistence is likely a result from antigenic selection. Moreover, persistent TCRs form high similarity clusters with other (non-)persistent sequences that potentially recognize the same epitopes. These data provide evidence for an antigen driven expansion of CD4+/CD8+ T-cells in SSc.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Escleroderma Sistêmico/etiologia , Escleroderma Sistêmico/metabolismo , Adulto , Antígenos/imunologia , Suscetibilidade a Doenças , Epitopos , Feminino , Frequência do Gene , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Memória Imunológica , Imunofenotipagem , Estudos Longitudinais , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Escleroderma Sistêmico/patologia
11.
Sci Rep ; 10(1): 13149, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32753661

RESUMO

Many hypotheses have been postulated to define the etiology of sporadic Parkinson's and Alzheimer's disorders (PD and AD) but there is no consensus on what causes these devastating age-related diseases. Braak staging of both pathologies helped researchers to better understand the progression and to identify their prodromal and symptomatic phases. Indeed, it is well accepted that Lewy body pathology and neurofibrillary tangles appearance correlates with disease progression and severity of symptoms in PD and AD, respectively. Additionally, several studies in PD and AD models try to disclose which cellular mechanisms are defaulted and trigger the neurodegenerative process that culminates with neuronal death causing PD and AD classical symptomatology. Herein, we determined expression levels of proteins involved in microtubule assembly, autophagic-lysosomal pathway and unfolded protein response in the cortex, hippocampus and SNpc of PD and AD patients, vascular dementia patients and aged-match controls. The differential expression allowed us to determine which pathways are determinant to synaptic dysfunction and to establish a time line for disease progression. Our results allow us to challenge the hypothesis that both PD and AD pathologies are caused by α-synuclein or Aß pathology propagation throughout the brain in a prion-like manner.


Assuntos
Doença de Alzheimer/metabolismo , Regulação da Expressão Gênica , Hipocampo/metabolismo , Proteínas do Tecido Nervoso/biossíntese , Doença de Parkinson/metabolismo , Resposta a Proteínas não Dobradas , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Córtex Cerebral/patologia , Feminino , Hipocampo/patologia , Humanos , Masculino , Doença de Parkinson/patologia
12.
Med Oral Patol Oral Cir Bucal ; 25(5): e616-e625, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32683391

RESUMO

BACKGROUND: The aim of this study was to describe the relative frequency and the main demographic and clinic-radiographic features related to patients diagnosed with Simple bone cyst (SBC) in an Oral Diagnosis Service in Southeast Brazil and present a review and discussion of international literature on this topic. MATERIAL AND METHODS: SBC cases from our service encompassing the period between 1978 and 2017 were selected. In addition, a literature search was performed in the Pubmed/MEDLINE online electronic database published between 1951 and 2019. RESULTS: A total of 2,459 cystic lesions were documented in our service, thus 60 patients were diagnosed with the SBC representing 2.4% of all jaw cystic. Most of cases were asymptomatic. Multiple SBC lesions were seen in two patients (3.4%) and association with cemento-osseous dysplasia was seen in one female patient (1.7%). A total of 793 cases were enrolled in this literature review. CONCLUSIONS: The SBC is an asymptomatic lesion often discovered in routine image exams in young patients. The unilocular, well defined margin with scalloped appearance is characteristic and helps the definition of diagnosis. This review suggests a different epidemiologic trend concerning to the sex and it confirms the posterior region of mandible as the more frequent location. The conservative treatment with limited exploration and curettage remains as the gold-standard treatment.


Assuntos
Cistos Ósseos , Tumores Odontogênicos , Brasil , Feminino , Humanos , Mandíbula , Instituições Acadêmicas
13.
Pediatr Obes ; 15(6): e12623, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32050058

RESUMO

BACKGROUND: Over the past three decades, the prevalence rate of overweight and obesity has increased in survivors with congenital heart disease, and little is known about the body composition and its association with clinical characteristics and lifestyle factors. OBJECTIVES: To evaluate excess total-body adiposity and central adiposity and, to describe associated factors. METHODS: Cross-sectional study with children and adolescents who underwent procedure to treat congenital heart disease, from January to July 2017. Sociodemographic and clinical characteristics, and lifestyle factors (dietary intake, physical activity, and sedentary behavior) were assessed. Adiposity was assessed using air-displacement plethysmography and waist circumference. Factors associated with excess total-body adiposity and central adiposity were analyzed using logistic regression models. RESULTS: Of 232 patients, 22.4% were identified with excess total-body adiposity and 24.6% with central adiposity. Significant factors positively associated with excess total-body adiposity were intake of added sugar and trans fatty acids, adjusted for confounding factors. Similarly, lifestyle factors were positively associated with central adiposity: intake of added sugar and trans fatty acids, sedentary behavior, and family history of obesity. CONCLUSIONS: Lifestyle factors were associated with excess total-body adiposity and central adiposity. Assessment of body composition and healthy-lifestyle counseling into outpatient care may be the key point to prevent obesity in children and adolescents with congenital heart disease.


Assuntos
Adiposidade , Cardiopatias Congênitas/metabolismo , Comportamento Sedentário , Açúcares/administração & dosagem , Ácidos Graxos trans/administração & dosagem , Adolescente , Índice de Massa Corporal , Criança , Estudos Transversais , Feminino , Cardiopatias Congênitas/complicações , Humanos , Estilo de Vida , Masculino , Obesidade Pediátrica/prevenção & controle
14.
Nanotechnology ; 31(13): 135702, 2020 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-31801117

RESUMO

Novel applications for memory devices demand nanoscale flexible structures. In particular, resistive switching (RS) devices are promising candidates for wearable and implantable technologies. Here, the Pt/Si/Ag/TiW metal-insulator-metal structure was fabricated and characterized on top of flexible substrates using a straightforward microfabrication process. We also showed that these substrates are compatible with sputtering deposition. RS was successfully achieved using both commercial cellulose cleanroom paper and bacterial cellulose, and polymer (PET) substrates. The bipolar switching behavior was observed for both flat and bent (under a radius of 3.5 mm) configurations. The observed phenomenon was explained by the formation/rupture of metallic Ag filaments in the otherwise insulating Si host layer.

15.
Sci Rep ; 9(1): 18755, 2019 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-31822738

RESUMO

A previously unreported tetragonal phase has been discovered in a epitaxially strained GdMnO3 thin films deposited on (001)-oriented SrTiO3 substrates by radio frequency (RF) magnetron sputtering. The tetragonal axis of the films grown up to a 35 nm thickness is perpendicular to the film surface and the basal lattice parameters are imposed by the cubic structure of the substrate. Furthermore, the emergence of a spontaneous electric polarization below ~32 K points to the stabilization of an improper ferroelectric phase at low temperatures, which is not observed in bulk GdMnO3. This work shows how strain engineering can be used to tailor the structure and properties of strongly correlated oxides.

16.
Arq. bras. med. vet. zootec. (Online) ; 71(5): 1719-1726, set.-out. 2019. tab
Artigo em Português | VETINDEX, LILACS | ID: biblio-1038674

RESUMO

Objetivou-se avaliar o comportamento ingestivo de cordeiros Santa Inês alimentados com resíduo de cervejaria desidratado (RCD). Foram utilizados 35 cordeiros, machos, não castrados, com peso médio inicial de 16,00±1,69kg e, aproximadamente, 70 dias de idade. Adotou-se o delineamento inteiramente ao acaso, com cinco tratamentos e sete repetições, consistindo os tratamentos em: 0; 20; 40; 60 e 80% de inclusão de RCD na porção concentrada da ração. A inclusão de RCD na ração não influenciou o tempo de alimentação (TAL; h/dia) e a eficiência de alimentação (gFDN/h; P>0,05). O TAL obtido neste estudo apresentou valor médio de 4,90h/dia. Observou-se efeito linear decrescente (P<0,05) com a inclusão do RCD, para as eficiências de alimentação (gMS/h) e ruminação (gMS/h e gFDN/h). Contudo, efeito linear crescente (P<0,05) foi constatado para tempo de ruminação e mastigação total, bem como para o número de mastigações merícicas por dia para os animais alimentados com o subproduto. A inclusão de resíduo de cervejaria desidratado influencia o comportamento ingestivo de cordeiros Santa Inês, diminuindo a eficiência de alimentação, quando relacionada ao consumo de matéria seca por hora, e aumentando o tempo de ruminação, podendo ser adicionado em até 20% na porção concentrada da ração.(AU)


The aim of this study was to evaluate the ingestive behavior of Santa Ines lambs fed dehydrated brewer's residue (DBR). Thirty-five male lambs were used, with an initial mean weight of 16.00±1.69kg and, approximately, 70 days of age. A completely randomized design was used, with five treatments and seven replicates, the treatments being: 0; 20; 40; 60 and 80% of inclusion of DBR in the concentrated portion of the ration. The inclusion of DBR in the ration did not influence feeding time (FT; h/day) and feeding efficiency (gNDF/h; P> 0.05). The FT obtained in this study had an average value of 4.90h/day. There was a decreasing linear effect (P< 0.05) for feed efficiency (gDM/h) and rumination efficiency (gDM/h and gNDF/h). However, linear increasing effect (P< 0.05) was observed for rumination and total chewing time, as well as for the number of chews per day for animals fed with the byproduct. The inclusion of dehydrated brewer's residue in the concentrate can influence the ingestive behavior of Santa Ines lambs, reducing feed efficiency, when related to the dry matter intake per hour, and increasing the total rumination time in Santa Ines lambs, it can be added up to 20% in the concentrated portion of the ration.(AU)


Assuntos
Animais , Masculino , Ovinos/crescimento & desenvolvimento , Indústria Cervejeira , Resíduos Industriais , Ração Animal/análise
17.
Biochim Biophys Acta Mol Basis Dis ; 1865(8): 2008-2023, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30572013

RESUMO

Protein post-translational modifications (PTMs) that potentiate protein aggregation have been implicated in several neurological disorders, including Alzheimer's (AD) and Parkinson's disease (PD). In fact, Tau and alpha-synuclein (ASYN) undergo several PTMs potentiating their aggregation and neurotoxicity. Recent data posits a role for acetylation in Tau and ASYN aggregation. Herein we aimed to clarify the role of Sirtuin-2 (SIRT2) and HDAC6 tubulin deacetylases as well as p300 acetyltransferase in AD and PD neurodegeneration. We used transmitochondrial cybrids that recapitulate pathogenic alterations observed in sporadic PD and AD patient brains and ASYN and Tau cellular models. We confirmed that Tau protein and ASYN are microtubules (MTs)-associated proteins (MAPs). Moreover, our results suggest that α-tubulin acetylation induced by SIRT2 inhibition is functionally associated with the improvement of MT dynamic determined by decreased Tau phosphorylation and by increased Tau/tubulin and ASYN/tubulin binding. Our data provide a strong evidence for a functional role of tubulin and MAPs acetylation on autophagic vesicular traffic and cargo clearance. Additionally, we showed that an accumulation of ASYN oligomers imbalance mitochondrial dynamics, which further compromise autophagy. We also demonstrated that an increase in Tau acetylation is associated with Tau phosphorylation. We found that p300, HDAC6 and SIRT2 influences Tau phosphorylation and autophagic flux in AD. In addition, we demonstrated that p300 and HDAC6 modulate Tau and Tubulin acetylation. Overall, our data disclose the role of Tau and ASYN modifications through acetylation in AD and PD pathology, respectively. Moreover, this study indicates that MTs can be a promising therapeutic target in the field of neurodegenerative disorders in which intracellular transport is altered.


Assuntos
Doença de Alzheimer/metabolismo , Autofagia , Microtúbulos/metabolismo , Doença de Parkinson/metabolismo , Acetilação , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Linhagem Celular , Desacetilase 6 de Histona/metabolismo , Humanos , Microtúbulos/patologia , Pessoa de Meia-Idade , Doença de Parkinson/patologia , Tubulina (Proteína)/metabolismo , alfa-Sinucleína/metabolismo , Proteínas tau/metabolismo
18.
Med Oral Patol Oral Cir Bucal ; 23(3): e262-e268, 2018 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-29680841

RESUMO

BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory disease mediated by T cells, which manifests as reticular (white) or erosive (red) lesions, that are eventually painful. Oral lichenoid lesion (OLL) are distinguished from OLP by the presence of precipitating factors. The aim of this study was to evaluate whether the presence of metallothionein, which is involved in anti-apoptotic pathways and the anti-oxidative response, could serve as a differential diagnostic for OLP and OLL. MATERIAL AND METHODS: We evaluated the expression of metallothionein in 40 cases of OLP and 20 cases of OLL using immunohistochemistry. RESULTS AND CONCLUSIONS: White OLP has higher concentrations of metallothionein than red OLP in basal and parabasal layers. Moreover, metallothionein was more frequently observed in the cytoplasm and nuclei of basal cells in OLP patients compared to the same regions of OLL cases. Metallothionein levels are related to OLP severity and may contribute to a differential diagnosis between OLP and OLL.


Assuntos
Amálgama Dentário , Líquen Plano Bucal/diagnóstico , Líquen Plano Bucal/metabolismo , Metalotioneína/biossíntese , Adulto , Amálgama Dentário/efeitos adversos , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doenças da Boca/diagnóstico , Doenças da Boca/etiologia , Doenças da Boca/patologia
19.
Physiol Res ; 67(3): 465-474, 2018 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-29527918

RESUMO

Urocortin 2 (UCN2) is a peptide related to corticotropin-releasing factor, capable of activating CRF-R2. Among its multisystemic effects, it has actions in all 3 muscle subtypes. This study's aim was to determine its potential role in two of the intrinsic eye muscle kinetics. Strips of iris sphincter (rabbit) and ciliary (bovine) muscles were dissected and mounted in isometric force-transducer systems filled with aerated-solutions. Contraction was elicited using carbachol (10(-6) M for iris sphincter, 10(-5) M for ciliary muscle), prior adding to all testing substances. UCN2 induced relaxation in iris sphincter muscle, being the effect maximal at 10(-7) M concentrations (-12.2 % variation vs. control). This effect was abolished with incubation of indomethacin, antisauvagine-30, chelerytrine and SQ22536, but preserved with L-nitro-L-arginine. In carbachol pre-stimulated ciliary muscle, UCN2 (10(-5) M) enhanced contraction (maximal effect of 18.2 % increase vs. control). UCN2 is a new modulator of iris sphincter relaxation, dependent of CRF-R2 activation, synthesis of prostaglandins (COX pathway) and both adenylate cyclase and PKC signaling pathways, but independent of nitric oxide production. Regarding ciliary muscle, UCN2 enhances carbachol-induced contraction, in higher doses.


Assuntos
Corpo Ciliar/fisiologia , Iris/fisiologia , Urocortinas/fisiologia , Adenilil Ciclases/metabolismo , Animais , Bovinos , Técnicas In Vitro , Masculino , Óxido Nítrico Sintase/metabolismo , Proteína Quinase C/metabolismo , Coelhos , Receptores de Hormônio Liberador da Corticotropina/metabolismo
20.
J Helminthol ; 92(5): 618-629, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28974282

RESUMO

Pterygodermatites (Paucipectines) zygodontomis, a nematode parasite of the small intestine of the rodent Necromys lasiurus, from Uberlândia, Minas Gerais state, Brazil, was analysed by light and scanning electron microscopy. Additionally, phylogenies were inferred from the mitochondrially encoded cytochrome c oxidase I gene (MT-CO1). Details of the helminth surface, such as the oral aperture, cephalic papillae, papillae in the posterior region of the body and longitudinal cuticular elements represented by spine-like projections and fans are presented, adding new taxonomic details. Molecular phylogenetic analysis, based on the MT-CO1, demonstrated that P. (P.) zygodontomis and Pterygodermatites (Paucipectines) jaegerskioldi form a unique evolutionary unit in accordance with the subgenus Paucipectines and corroborated their occurrence in cricetid and didelphid hosts.


Assuntos
Doenças dos Roedores/parasitologia , Sigmodontinae/parasitologia , Infecções por Spirurida/veterinária , Spirurina/classificação , Spirurina/isolamento & purificação , Estruturas Animais/anatomia & histologia , Animais , Brasil , Análise por Conglomerados , Complexo IV da Cadeia de Transporte de Elétrons/genética , Microscopia , Microscopia Eletrônica , Filogenia , Análise de Sequência de DNA , Infecções por Spirurida/parasitologia , Spirurina/anatomia & histologia , Spirurina/genética
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