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Sodium overload during childhood impairs baroreflex sensitivity and increases arterial blood pressure and heart rate in adulthood; these effects persist even after high-salt diet (HSD) withdrawal. However, the literature lacks details on the effects of HSD during postnatal phases on cardiac ischemia/reperfusion responses in adulthood. The current study aimed to elucidate the impact of HSD during infancy adolescence on isolated heart function and cardiac ischemia/reperfusion responses in adulthood. Male 21-day-old Wistar rats were treated for 60 days with hypertonic saline solution (NaCl; 0.3M; experimental group) or tap water (control group). Subsequently, both groups were maintained on a normal sodium diet for 30 days. Subsequently, the rats were euthanized, and their hearts were isolated and perfused according to the Langendorff technique. After 30 min of the basal period, the hearts were subjected to 20 min of anoxia, followed by 20 min of reperfusion. The basal contractile function was unaffected by HSD. However, HSD elevated the left ventricular end-diastolic pressure during reperfusion (23.1 ± 5.2 mmHg vs. 11.6 ± 1.4 mmHg; p < 0.05) and increased ectopic incidence period during reperfusion (208.8 ± 32.9s vs. 75.0 ± 7.8s; p < 0.05). In conclusion, sodium overload compromises cardiac function after reperfusion events, diminishes ventricular relaxation, and increases the severity of arrhythmias, suggesting a possible arrhythmogenic effect of HSD in the postnatal phases.
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Arritmias Cardíacas , Traumatismo por Reperfusão Miocárdica , Ratos Wistar , Animais , Ratos , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Masculino , Traumatismo por Reperfusão Miocárdica/etiologia , Traumatismo por Reperfusão Miocárdica/fisiopatologia , Diástole/fisiologia , Cloreto de Sódio na Dieta/efeitos adversos , Frequência Cardíaca/fisiologiaRESUMO
The scarcity of nonrenewable resources and the increase in environmental pollution have intensified the search for materials that exhibit specific characteristics and are nontoxic, renewable, and sustainable. Thus, the objective of this work was to produce natural polyphenol adhesives reinforced with rice husk and its ash to increase the mechanical resistance and moisture resistance of the glue line in wood bonded joints. Polyphenols were extracted from the bark of Stryphnodendron adstringens (Mart.) Coville (barbatimão). Adhesives were produced with a 50 % solid and 50 % liquid composition. Rice husk and husk ash underwent X-ray fluorescence analysis (XRF). Adhesives and reinforcement material were characterized by Fourier transform infrared (FTIR) and thermogravimetric analyses (TGA). The adhesives were glued in a mechanical press in specimens made of Pinus elliottii, which were subjected to shear testing of the wet and dry glue line. As a result, the chemical components present in rice husk and its ash positively influenced the properties of the adhesives. The mechanical glue line shear test showed that the adhesive reinforced with rice husk ash did not show a statistically significant difference. However, natural adhesives based on polyphenols from barbatimão strengthened with rice husk and ash showed improved properties, demonstrating how much it pays to use the residue of rice production to reinforce the matrix of tannin adhesives. Thus, it can be determined that reinforcement with rice husk and ash is efficient in improving some properties of natural adhesives based on polyphenols.
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Oryza , Árvores , Oryza/química , Brasil , Casca de Planta/química , Polifenóis/análise , EcossistemaRESUMO
Cancer homeostasis depends on a balance between activated oncogenic pathways driving tumorigenesis and engagement of stress response programs that counteract the inherent toxicity of such aberrant signaling. Although inhibition of oncogenic signaling pathways has been explored extensively, there is increasing evidence that overactivation of the same pathways can also disrupt cancer homeostasis and cause lethality. We show here that inhibition of protein phosphatase 2A (PP2A) hyperactivates multiple oncogenic pathways and engages stress responses in colon cancer cells. Genetic and compound screens identify combined inhibition of PP2A and WEE1 as synergistic in multiple cancer models by collapsing DNA replication and triggering premature mitosis followed by cell death. This combination also suppressed the growth of patient-derived tumors in vivo. Remarkably, acquired resistance to this drug combination suppressed the ability of colon cancer cells to form tumors in vivo. Our data suggest that paradoxical activation of oncogenic signaling can result in tumor-suppressive resistance.
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In the present study, we show that SARS-CoV-2 can infect palatine tonsils, adenoids, and secretions in children without symptoms of COVID-19, with no history of recent upper airway infection. We studied 48 children undergoing tonsillectomy due to snoring/OSA or recurrent tonsillitis between October 2020 and September 2021. Nasal cytobrushes, nasal washes, and tonsillar tissue fragments obtained at surgery were tested by RT-qPCR, immunohistochemistry (IHC), flow cytometry, and neutralization assay. We detected the presence of SARS-CoV-2 in at least one specimen tested in 27% of patients. IHC revealed the presence of the viral nucleoprotein in epithelial surface and in lymphoid cells in both extrafollicular and follicular regions, in adenoids and palatine tonsils. Also, IHC for the SARS-CoV-2 non-structural protein NSP-16 indicated the presence of viral replication in 53.8% of the SARS-CoV-2-infected tissues. Flow cytometry showed that CD20+ B lymphocytes were the most infected phenotypes, followed by CD4+ lymphocytes and CD123 dendritic cells, CD8+ T lymphocytes, and CD14+ macrophages. Additionally, IF indicated that infected tonsillar tissues had increased expression of ACE2 and TMPRSS2. NGS sequencing demonstrated the presence of different SARS-CoV-2 variants in tonsils from different tissues. SARS-CoV-2 antigen detection was not restricted to tonsils but was also detected in nasal cells from the olfactory region. Palatine tonsils and adenoids are sites of prolonged RNA presence by SARS-CoV-2 in children, even without COVID-19 symptoms. IMPORTANCE This study shows that SRS-CoV-2 of different lineages can infect tonsils and adenoids in one quarter of children undergoing tonsillectomy. These findings bring advancement to the area of SARS-CoV-2 pathogenesis, by showing that tonsils may be sites of prolonged infection, even without evidence of recent COVID-19 symptoms. SARS-CoV-2 infection of B and T lymphocytes, macrophages, and dendritic cells may interfere with the mounting of immune responses in these secondary lymphoid organs. Moreover, the shedding of SARS-CoV-2 RNA in respiratory secretions from silently infected children raises concern about possible diagnostic confusion in the presence of symptoms of acute respiratory infections caused by other etiologies.
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Osteoporosis is a systemic disease characterized by a reduction in bone mineral density. The dissemination of knowledge about the disease can be a viable alternative for promoting preventive behavior and self-care. This study sought to identify the main characteristics of bone health programs for older persons. We conducted an integrative review, searching for studies published between 2011 and 2022 in the CAPES periodicals database, Web of Science, PubMed, and Google Scholar using English descriptors. A total of 10,093 studies were retrieved, seven of which were selected after applying the inclusion criteria. The findings show that bone health education programs aim to empower older people by increasing knowledge about the disease and raising awareness about calcium and vitamin D intake, osteoporosis medications, and the importance of changing habits and exercise. Programs generally consist of group or individual meetings, with sessions lasting 50 to 60 minutes. Class sizes may be limited or unrestricted. Follow-up during the educational process was also found to be important. Tailoring topics to the reality and interests of participants appears to be another positive way of promoting the adoption of self-care practices.
A osteoporose é uma doença sistêmica caracterizada pela redução da densidade mineral óssea. A difusão do conhecimento sobre à doença, pode ser uma alternativa viável para atitudes preventivas e de autocuidado. Dessa forma, esse artigo procura identificar como são os programas sobre saúde óssea para idosos. Trata-se de uma revisão integrativa de estudos publicados entre 2011 e 2022 nas bases de dados Periódicos Capes, Web of Science, PubMed e Google Scholar em inglês. Foram encontrados 10.093 estudos, sendo selecionados 7 depois dos critérios de inclusão. Foi possível verificar que os programas de educação para saúde óssea possuem o objetivo de empoderar o idoso pelo aumento do conhecimento sobre a doença, conscientizar sobre o consumo de cálcio e vitamina D ou de medicamentos para osteoporose, mudanças de hábitos e a prática de exercícios físicos. Os programas geralmente são realizados com reuniões em grupo ou individualizados, com sessões de 50 a 60 minutos, podendo ou não, delimitar o número de indivíduos em cada uma delas. Nota-se que acompanhar a evolução do processo educativo também é importante. A contextualização dos temas junto a realidade e interesse dos idosos, parece ser outra forma positiva para despertar atitudes de autocuidado.
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Osteoporose , Humanos , Idoso , Idoso de 80 Anos ou mais , Osteoporose/prevenção & controle , Educação em Saúde , Cálcio da Dieta , Densidade Óssea , Exercício FísicoRESUMO
Resumo A osteoporose é uma doença sistêmica caracterizada pela redução da densidade mineral óssea. A difusão do conhecimento sobre à doença, pode ser uma alternativa viável para atitudes preventivas e de autocuidado. Dessa forma, esse artigo procura identificar como são os programas sobre saúde óssea para idosos. Trata-se de uma revisão integrativa de estudos publicados entre 2011 e 2022 nas bases de dados Periódicos Capes, Web of Science, PubMed e Google Scholar em inglês. Foram encontrados 10.093 estudos, sendo selecionados 7 depois dos critérios de inclusão. Foi possível verificar que os programas de educação para saúde óssea possuem o objetivo de empoderar o idoso pelo aumento do conhecimento sobre a doença, conscientizar sobre o consumo de cálcio e vitamina D ou de medicamentos para osteoporose, mudanças de hábitos e a prática de exercícios físicos. Os programas geralmente são realizados com reuniões em grupo ou individualizados, com sessões de 50 a 60 minutos, podendo ou não, delimitar o número de indivíduos em cada uma delas. Nota-se que acompanhar a evolução do processo educativo também é importante. A contextualização dos temas junto a realidade e interesse dos idosos, parece ser outra forma positiva para despertar atitudes de autocuidado.
Abstract Osteoporosis is a systemic disease characterized by a reduction in bone mineral density. The dissemination of knowledge about the disease can be a viable alternative for promoting preventive behavior and self-care. This study sought to identify the main characteristics of bone health programs for older persons. We conducted an integrative review, searching for studies published between 2011 and 2022 in the CAPES periodicals database, Web of Science, PubMed, and Google Scholar using English descriptors. A total of 10,093 studies were retrieved, seven of which were selected after applying the inclusion criteria. The findings show that bone health education programs aim to empower older people by increasing knowledge about the disease and raising awareness about calcium and vitamin D intake, osteoporosis medications, and the importance of changing habits and exercise. Programs generally consist of group or individual meetings, with sessions lasting 50 to 60 minutes. Class sizes may be limited or unrestricted. Follow-up during the educational process was also found to be important. Tailoring topics to the reality and interests of participants appears to be another positive way of promoting the adoption of self-care practices.
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INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE: This approach is intended for tumors centered in the jugular foramen with extensions between intracranial and extracranial spaces, possible spread to the middle ear, and variable bony destruction. 1,2. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT: Jugular foramen paragangliomas are complex lesions that usually invade and fill related venous structures. They present complex relationships with skull base neurovascular structures as internal carotid artery, lower cranial nerves (CNs), middle ear, and mastoid segment of facial nerve. In this way, it is essential to perform an adequate preoperative vascular study to evaluate sinus patency and the tumor blood supply, besides a computed tomography scan to depict bone erosion. ESSENTIAL STEPS OF THE PROCEDURE: Mastoidectomy through an infralabyrinthine route up to open the lateral border of jugular foramen, allowing exposure from the sigmoid sinus to internal jugular vein. Skeletonization of facial canal without exposure of facial nerve is performed and opening of facial recess to give access to the middle ear in way of a fallopian bridge technique. 2-10. PITFALLS/AVOIDANCE OF COMPLICATIONS: If there is preoperative preservation of lower CN function, it is important to not remove the anteromedial wall of the internal jugular vein and jugular bulb. In addition, facial nerve should be exposed just in case of preoperative facial palsy to decompress or reconstruct the nerve. VARIANTS AND INDICATIONS FOR THEIR USE: Variations are related mainly with temporal bone drilling depending on the extensions of the lesion, its source of blood supply, and preoperative preservation of CN function.Informed consent was obtained from the patient for the procedure and publication of his image.Anatomy images were used with permission from:⢠Ceccato GHW, Candido DNC, and Borba LAB. Infratemporal fossa approach to the jugular foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.⢠Ceccato GHW, Candido DNC, de Oliveira JG, and Borba LAB. Microsurgical Anatomy of the Jugular Foramen. In: Borba LAB and de Oliveira JG. Microsurgical and Endoscopic Approaches to the Skull Base. Thieme Medical Publishers. 2021.
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Tumor do Glomo Jugular , Forâmen Jugular , Humanos , Forâmen Jugular/diagnóstico por imagem , Forâmen Jugular/cirurgia , Base do Crânio/diagnóstico por imagem , Base do Crânio/cirurgia , Base do Crânio/anatomia & histologia , Tumor do Glomo Jugular/cirurgia , Osso Temporal/diagnóstico por imagem , Osso Temporal/cirurgia , Nervos CranianosRESUMO
This study aimed to evaluate the influence of the addition of the cationic surfactant cetyltrimethylammonium bromide (CTAB) in microfibrillated cellulose (MFC/CNFs) suspensions submitted to different pretreatments to produce redispersible spray-dried (SD) MFC/CNFs. Suspensions pretreated with 5 % and 10 % sodium silicate and oxidized with 2,2,6,6,-tetramethylpiperidinyl-1-oxyl (TEMPO) were modified with CTAB surfactant and subsequently dried by SD. The SD-MFC/CNFs aggregates were redispersed by ultrasound to produce cellulosic films by the casting method. In summary, the results demonstrated that the addition of CTAB surfactant to the TEMPO-oxidized suspension was critical to achieving the most effective redispersion. The experimental results obtained using micrographs, optical (UV-Vis), mechanical, water vapor barrier properties, and the quality index confirmed that the addition of CTAB to the TEMPO-oxidized suspension favored the redispersion of spray-dried aggregates, development of cellulosic films with attractive properties, offering possibilities for the elaboration of new products, for example, in the production of bionanocomposites with higher mechanical performance. This research brings interesting insights into the redispersion and application of SD-MFC/CNFs aggregates, strengthening the commercialization of MFC/CNFs for industrial use.
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Biofilmes , Celulose , Suspensões , CetrimônioRESUMO
Post-partum depression (PPD) with varying clinical manifestations affecting new parents remains underdiagnosed and poorly treated. This minireview revisits the pharmacotherapy, and relevant etiological basis, capable of advancing preclinical research frameworks. Maternal tasks accompanied by numerous behavioral readouts demand modeling different paradigms that reflect the complex and heterogenous nature of PPD. Hence, effective PPD-like characterization in animals towards the discovery of pharmacological intervention demands research that deepens our understanding of the roles of hormonal and non-hormonal components and mediators of this psychiatric disorder.
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Vegetable tannins are excellent options to produce adhesives for the panel industry since they have the capacity to reduce formaldehyde emissions and are derived from renewable sources. They also allow for the possibility of increasing the resistance of the glue line through the use of natural reinforcements such as cellulose nanofibrils. Condensed tannins, polyphenols isolated from tree bark, are widely studied for the production of natural adhesives as an alternative to commercial synthetic adhesives. So, the purpose of our research is to show a natural adhesive alternative for wood bonding. Therefore, the objective of the study was to evaluate the quality of tannin adhesives of different species reinforced with different nanofibrils and thus predict which adhesive is the most promising at different concentrations of reinforcement and with different types of polyphenols. To meet this objective, polyphenols were extracted from the bark, nanofibrils were obtained, and both processes followed the current standards. Then, the adhesives were produced, their properties were characterized, and they were chemically analyzed via Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). A mechanical shear analysis of the glue line was also performed. According to the results, the addition of cellulose nanofibrils affected the physical properties of the adhesives, mostly the content of solids and the gel time. In the FTIR spectra, the OH band of the 5% Pinus and 5% Eucalyptus (EUC) TEMPO in the barbatimao adhesive and the 5% EUC of the cumate red adhesive were reduced, possibly due to their higher moisture resistance. Mechanical tests of the glue line showed that barbatimao with 5% Pinus and cumate red with 5% EUC performed best in the dry and wet shear tests. The control was the best-performing sample in the test of the commercial adhesives. The cellulose nanofibrils used as reinforcement did not change the thermal resistance of the adhesives. Therefore, the addition of cellulose nanofibrils to these tannins is an interesting means of increasing the mechanical strength, as occurred in commercial adhesive with 5% EUC. Thus, the physical and mechanical properties of tannin adhesives were better with reinforcement, making it possible to expand the use of these adhesives in the panel industry. At the industrial level, it is important to replace synthetic products with natural ones. Besides environmental and health issues, there is the question of the value of petroleum-based products, which have been widely studied so that they can be replaced.
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Polifenóis , Madeira , Polifenóis/análise , Madeira/química , Adesivos/química , Celulose/química , Taninos/químicaRESUMO
Specific kinds of enzymes have been used as an eco-friendly pre-treatment for mechanical extraction of cellulose nanofibrils (CNFs) from vegetal pulps. Another well-established pre-treatment is the 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO)-mediated oxidation, which has gained considerable attention. Pre-treatments assist in fiber swelling, facilitating mechanical fibrillation, and reducing energy consumption; however, some of these methods are extremely expensive. This work aimed to evaluate the influence of enzymatic pre-treatment with endoglucanase on the energy consumption during mechanical fibrillation of cellulose pulps. Bleached pulps from Eucalyptus sp. and Pinus sp. were pre-treated with endoglucanase enzyme compared to TEMPO-meditated oxidation. Average diameters of CNFs pre-treated with enzymes were close to that found for TEMPO-oxidized nanofibrils (TOCNFs). Results showed that enzymatic pre-treatment did not significantly modify the pulp chemical and morphological characteristics with efficient stabilization of the CNFs suspension at higher supernatant turbidity. Energy consumption of pulps treated with endoglucanase enzymes was lower than that shown by pulps treated with TEMPO, reaching up to 58% of energy savings. The enzyme studied in the pulp treatment showed high efficiency in reducing energy consumption during mechanical fibrillation and production of films with high mechanical quality, being an eco-friendly option for pulp treatment.
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Celulase , Celulose , Oxirredução , Compostos de Sódio , Ácido HipoclorosoRESUMO
The applicability of cellulose nanofibrils (CNFs) has received attention due to their attractive properties. This study proposes the functionalization of açai CNFs with copaiba oil and vegetal tannins to produce films with potential for packaging. Bio-based films were evaluated by vapor permeability, colorimetry, and mechanical strength. CNFs were produced by mechanical fibrillation, from suspensions of bleached açai fibers and commercial eucalipytus pulp. Moreover, copaiba oil and vegetal tannin were added to the CNFs to produce films/nanopapers by casting from both suspensions with concentrations of 1% (based on CNF dry mass). The bulk densities of the eucalyptus CNF films were higher (1.126-1.171 g cm-3) compared to the açai CNF ones. Films from eucalyptus and açai pulps containing copaiba oil and tannins presented higher Tonset and Tmax, respectively (312 and 370 °C). Films with açaí CNFs functionalized with copaiba oil and tannin showed the lowest permeability value (370 g day-1 m-2). Films produced with eucalyptus pulp, and eucalyptus pulp functionalized with copaiba oil highlighted by superior mechanical strength, achieving 133.8 and 121.4 MPa, respectively. The evaluation of colorimetry showed a greater tendency to yellowing for açai films, especially those functionalized with vegetal tannins. Besides the low cost, functionalized vegetal-based nanomaterials could have attractive properties, with potential for application as some kind of packaging, for transporting basic products, such as breads, flours, or products with low moisture content, enabling efficient utilization of forest wastes.
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Eucalyptus , Nanofibras , Óleos Voláteis , Celulose , Florestas , Suspensões , TaninosRESUMO
Este estudo buscou identificar a presença dos três referenciais do ensino esportivo da Pedagogia do Esporte nas disciplinas de futsal de cursos de Educação Física, discutindo possíveis direcionamentos na formação de professores e treinadores da modalidade. Consideramos apenas cursos presenciais, de universidades públicas, ativos no segundo semestre de 2019. Por meio de uma análise documental, investigamos ementas, programas e objetivos das disciplinas. Ao realizar uma Análise Temática sobre os 110 documentos encontrados, percebemos que estes priorizam os conteúdos voltados ao Referencial Técnico-tático e que existe grande defasagem em relação ao Referencial Socioeducativo. Assim, uma vez evidenciado o desequilíbrio exposto nesta pesquisa, estes resultados podem contribuir em revisões de ementas e currículos, na expectativa de que a importância atribuída aos conteúdos técnico-táticos nas disciplinas de futsal seja estendida aos elementos históricos, culturais, educativos e sociais. (AU)
The study aims to identify the presence of the three references of sports learning from Sport Pedagogy in Futsal subjects from Physical Education Degree, discussing possible directions on the development of professors and coaches of this sport. We only considered the presential courses, of public universities, active on the second semester of 2019. Through a documental analysis, we searched syllabus, curriculums, and discipline goals. Performing a Thematic Analysis about the all 110 files founded, we realized that they prioritize the technical-tactical elements and present a huge gap in relation of socio-educational reference. Thus, once the unbalance exposed in this research is evidenced, the results can contribute to syllabus and curriculum revisions, in the expectation that the importance attributed to the technical-tactical elements will be extended to historical, culture, educational and socials elements. (AU)
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Humanos , Educação Física e Treinamento , Futebol , Ensino , Universidades , Capacitação de Professores , Esportes de Equipe , AprendizagemRESUMO
Malignant transformation involves an orchestrated rearrangement of cell cycle regulation mechanisms that must balance autonomic mitogenic impulses and deleterious oncogenic stress. Human papillomavirus (HPV) infection is highly prevalent in populations around the globe, whereas the incidence of cervical cancer is 0.15%. Since HPV infection primes cervical keratinocytes to undergo malignant transformation, we can assume that the balance between transforming mitogenic signals and oncogenic stress is rarely attained. We showed that highly transforming mitogenic signals triggered by HRasG12V activity in E6E7-HPV-keratinocytes generate strong replication and oxidative stresses. These stresses are counteracted by autophagy induction that buffers the rapid increase of ROS that is the main cause of genotoxic stress promoted by the oncoprotein. As a result, autophagy creates a narrow window of opportunity for malignant keratinocytes to emerge. This work shows that autophagy is crucial to allow the transition of E6E7 keratinocytes from an immortalized to a malignant state caused by HRasG12V.
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Alphapapillomavirus/patogenicidade , Autofagia , Transformação Celular Viral , Dano ao DNA , Queratinócitos/virologia , Infecções por Papillomavirus/virologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Neoplasias do Colo do Útero/virologia , Alphapapillomavirus/genética , Alphapapillomavirus/metabolismo , Linhagem Celular , Proliferação de Células , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular , Interações Hospedeiro-Patógeno , Humanos , Queratinócitos/metabolismo , Queratinócitos/patologia , Mitose , Proteínas Oncogênicas Virais/genética , Proteínas Oncogênicas Virais/metabolismo , Estresse Oxidativo , Proteínas E7 de Papillomavirus/genética , Proteínas E7 de Papillomavirus/metabolismo , Infecções por Papillomavirus/metabolismo , Infecções por Papillomavirus/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais , Neoplasias do Colo do Útero/metabolismo , Neoplasias do Colo do Útero/patologiaRESUMO
Malignant transformation involves an orchestrated rearrangement of cell cycle regulation mechanisms that must balance autonomic mitogenic impulses and deleterious oncogenic stress. Human papillomavirus (HPV) infection is highly prevalent in populations around the globe, whereas the incidence of cervical cancer is 0.15%. Since HPV infection primes cervical keratinocytes to undergo malignant transformation, we can assume that the balance between transforming mitogenic signals and oncogenic stress is rarely attained. We showed that highly transforming mitogenic signals triggered by HRasG12V activity in E6E7–HPV–keratinocytes generate strong replication and oxidative stresses. These stresses are counteracted by autophagy induction that buffers the rapid increase of ROS that is the main cause of genotoxic stress promoted by the oncoprotein. As a result, autophagy creates a narrow window of opportunity for malignant keratinocytes to emerge. This work shows that autophagy is crucial to allow the transition of E6E7 keratinocytes from an immortalized to a malignant state caused by HRasG12V.
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B cells contribute to the immune system in many ways such as antigen presentation to CD4+ T cells, secretion of cytokines and lymphoid tissue organogenesis. Furthermore, they are the only cell type capable of producing immunoglobulins. B cells also account for critical aspects of the resistance against intracellular pathogens. Trypanosoma cruzi is an intracellular parasite that sabotages humoral response by depletion of immature B cells. Polyclonal activation and secretion of non-specific antibodies are also other mechanisms used by T cruzi to evade and subvert the mammalian host immune system, leading to increased parasitemia and susceptibility to Chagas' disease. It remained unclear whether B cell depletion occurs due to direct contact with T. cruzi or results from a global increase in inflammation. Unlike previous reports, we demonstrated in this study that T. cruzi infects human B cells, resulting in parasite-induced activation of caspase-7 followed by proteolytic cleavage of phospholipase Cγ1 and cell death. These data contribute to explain the mechanisms ruling B-cell depletion and evasion of the immune response by T. cruzi.
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Actinas/metabolismo , Linfócitos B/imunologia , Linfócitos B/metabolismo , Caspase 7/metabolismo , Interações Hospedeiro-Patógeno , Fosfolipase C gama/metabolismo , Trypanosoma cruzi/imunologia , Morte Celular , Doença de Chagas/imunologia , Doença de Chagas/metabolismo , Doença de Chagas/parasitologia , Humanos , ProteóliseRESUMO
B cells contribute to the immune system in many ways such as antigen presentation to CD4+ T cells, secretion of cytokines and lymphoid tissue organogenesis. Furthermore, they are the only cell type capable of producing immunoglobulins. B cells also account for critical aspects of the resistance against intracellular pathogens. Trypanosoma cruzi is an intracellular parasite that sabotages humoral response by depletion of immature B cells. Polyclonal activation and secretion of non-specific antibodies are also other mechanisms used by T cruzi to evade and subvert the mammalian host immune system, leading to increased parasitemia and susceptibility to Chagas’ disease. It remained unclear whether B cell depletion occurs due to direct contact with T. cruzi or results from a global increase in inflammation. Unlike previous reports, we demonstrated in this study that T. cruzi infects human B cells, resulting in parasite-induced activation of caspase-7 followed by proteolytic cleavage of phospholipase Cgama1 and cell death. These data contribute to explain the mechanisms ruling B-cell depletion and evasion of the immune response by T. cruzi.
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Cocoa shell was evaluated as a precursor for cellulose nanofibrils (NFCs) using mechanical defibrillation. Its morphology was analysed using optical microscopy and scanning electron microscopy with field emission. Rheological and mechanical behaviour were evaluated through flow curves with a strain rate ranging from 0 to 300 s-1 at 25 °C and by means of oscillatory frequency sweeps (0.01â¯Hz-10â¯Hz) and shear stress (3 Pa). The thermal-mechanical behaviour was determined by a temperature sweep with a heating rate of 3 °C min-1 and a temperature range of 25 °C-100 °C. Micrographs identified the presence of protoxilem with a mean diameter of 23.34 nm. The flow curve showed the characteristic behaviour of a pseudoplastic fluid. The storage module (G') and the loss modulus (Gâ³) were dependent on the frequency applied, indicating that the material exhibits a weak gel characteristic. The viscoelastic characteristics were influenced by temperature. Therefore, cocoa shell is a new alternative in the production of nanocellulose.