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1.
Mol Biol Rep ; 50(6): 5273-5282, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37145211

RESUMO

BACKGROUND: Commensal bacteria secrete metabolites that reach distant cancer cells through the circulation and influence cancer behavior. Deoxycholic acid (DCA), a hormone-like metabolite, is a secondary bile acid specifically synthesized by intestinal microbes. DCA may have both pro- and antineoplastic effects in cancers. METHODS AND RESULTS: The pancreatic adenocarcinoma cell lines, Capan-2 and BxPC-3, were treated with 0.7 µM DCA, which corresponds to the reference concentration of DCA in human serum. DCA influenced the expression of epithelial to mesenchymal transition (EMT)-related genes, significantly decreased the expression level of the mesenchymal markers, transcription factor 7- like 2 (TCF7L2), snail family transcriptional repressor 2 (SLUG), CLAUDIN-1, and increased the expression of the epithelial genes, zona occludens 1 (ZO-1) and E-CADHERIN, as shown by real-time PCR and Western blotting. Consequently, DCA reduced the invasion capacity of pancreatic adenocarcinoma cells in Boyden chamber experiments. DCA induced the protein expression of oxidative/nitrosative stress markers. Moreover, DCA reduced aldehyde dehydrogenase 1 (ALDH1) activity in an Aldefluor assay and ALDH1 protein level, suggesting that DCA reduced stemness in pancreatic adenocarcinoma. In Seahorse experiments, DCA induced all fractions of mitochondrial respiration and glycolytic flux. The ratio of mitochondrial oxidation and glycolysis did not change after DCA treatment, suggesting that cells became hypermetabolic. CONCLUSION: DCA induced antineoplastic effects in pancreatic adenocarcinoma cells by inhibiting EMT, reducing cancer stemness, and inducing oxidative/nitrosative stress and procarcinogenic effects such as hypermetabolic bioenergetics.


Assuntos
Adenocarcinoma , Antineoplásicos , Neoplasias Pancreáticas , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Transição Epitelial-Mesenquimal , Antineoplásicos/farmacologia , Ácido Desoxicólico/farmacologia , Linhagem Celular Tumoral , Neoplasias Pancreáticas
2.
Cell Mol Life Sci ; 79(5): 243, 2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-35429253

RESUMO

Bile acids are soluble derivatives of cholesterol produced in the liver that subsequently undergo bacterial transformation yielding a diverse array of metabolites. The bulk of bile acid synthesis takes place in the liver yielding primary bile acids; however, other tissues have also the capacity to generate bile acids (e.g. ovaries). Hepatic bile acids are then transported to bile and are subsequently released into the intestines. In the large intestine, a fraction of primary bile acids is converted to secondary bile acids by gut bacteria. The majority of the intestinal bile acids undergo reuptake and return to the liver. A small fraction of secondary and primary bile acids remains in the circulation and exert receptor-mediated and pure chemical effects (e.g. acidic bile in oesophageal cancer) on cancer cells. In this review, we assess how changes to bile acid biosynthesis, bile acid flux and local bile acid concentration modulate the behavior of different cancers. Here, we present in-depth the involvement of bile acids in oesophageal, gastric, hepatocellular, pancreatic, colorectal, breast, prostate, ovarian cancer. Previous studies often used bile acids in supraphysiological concentration, sometimes in concentrations 1000 times higher than the highest reported tissue or serum concentrations likely eliciting unspecific effects, a practice that we advocate against in this review. Furthermore, we show that, although bile acids were classically considered as pro-carcinogenic agents (e.g. oesophageal cancer), the dogma that switch, as lower concentrations of bile acids that correspond to their serum or tissue reference concentration possess anticancer activity in a subset of cancers. Differences in the response of cancers to bile acids lie in the differential expression of bile acid receptors between cancers (e.g. FXR vs. TGR5). UDCA, a bile acid that is sold as a generic medication against cholestasis or biliary surge, and its conjugates were identified with almost purely anticancer features suggesting a possibility for drug repurposing. Taken together, bile acids were considered as tumor inducers or tumor promoter molecules; nevertheless, in certain cancers, like breast cancer, bile acids in their reference concentrations may act as tumor suppressors suggesting a Janus-faced nature of bile acids in carcinogenesis.


Assuntos
Ácidos e Sais Biliares , Neoplasias Esofágicas , Ácidos e Sais Biliares/metabolismo , Carcinogênese/patologia , Neoplasias Esofágicas/metabolismo , Humanos , Fígado/metabolismo , Masculino
3.
Molecules ; 28(15)2023 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-37570868

RESUMO

Breast cancer patients are characterized by the oncobiotic transformation of multiple microbiome communities, including the gut microbiome. Oncobiotic transformation of the gut microbiome impairs the production of antineoplastic bacterial metabolites. The goal of this study was to identify bacterial metabolites with antineoplastic properties. We constructed a 30-member bacterial metabolite library and screened the library compounds for effects on cell proliferation and epithelial-mesenchymal transition. The metabolites were applied to 4T1 murine breast cancer cells in concentrations corresponding to the reference serum concentrations. However, yric acid, glycolic acid, d-mannitol, 2,3-butanediol, and trans-ferulic acid exerted cytostatic effects, and 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, and vanillic acid exerted hyperproliferative effects. Furthermore, 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid, 2,3-butanediol, and hydrocinnamic acid inhibited epithelial-to-mesenchymal (EMT) transition. We identified redox sets among the metabolites (d-mannitol-d-mannose, 1-butanol-butyric acid, ethylene glycol-glycolic acid-oxalic acid), wherein only one partner within the set (d-mannitol, butyric acid, glycolic acid) possessed bioactivity in our system, suggesting that changes to the local redox potential may affect the bacterial secretome. Of the nine bioactive metabolites, 2,3-butanediol was the only compound with both cytostatic and anti-EMT properties.


Assuntos
Antineoplásicos , Neoplasias da Mama , Citostáticos , Humanos , Animais , Camundongos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Transição Epitelial-Mesenquimal , Citostáticos/farmacologia , Ácido Butírico/farmacologia , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Proliferação de Células
4.
Cancer Metastasis Rev ; 40(4): 1223-1249, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34967927

RESUMO

Breast cancer, the most frequent cancer in women, is characterized by pathological changes to the microbiome of breast tissue, the tumor, the gut, and the urinary tract. Changes to the microbiome are determined by the stage, grade, origin (NST/lobular), and receptor status of the tumor. This year is the 50th anniversary of when Hill and colleagues first showed that changes to the gut microbiome can support breast cancer growth, namely that the oncobiome can reactivate excreted estrogens. The currently available human and murine data suggest that oncobiosis is not a cause of breast cancer, but can support its growth. Furthermore, preexisting dysbiosis and the predisposition to cancer are transplantable. The breast's and breast cancer's inherent microbiome and the gut microbiome promote breast cancer growth by reactivating estrogens, rearranging cancer cell metabolism, bringing about a more inflammatory microenvironment, and reducing the number of tumor-infiltrating lymphocytes. Furthermore, the gut microbiome can produce cytostatic metabolites, the production of which decreases or blunts breast cancer. The role of oncobiosis in the urinary tract is largely uncharted. Oncobiosis in breast cancer supports invasion, metastasis, and recurrence by supporting cellular movement, epithelial-to-mesenchymal transition, cancer stem cell function, and diapedesis. Finally, the oncobiome can modify the pharmacokinetics of chemotherapeutic drugs. The microbiome provides novel leverage on breast cancer that should be exploited for better management of the disease.


Assuntos
Neoplasias da Mama , Microbiota , Animais , Bactérias/metabolismo , Neoplasias da Mama/patologia , Disbiose/microbiologia , Estrogênios/metabolismo , Feminino , Humanos , Camundongos , Microambiente Tumoral
5.
Adv Exp Med Biol ; 1225: 137-153, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32030653

RESUMO

Microbes, which live in the human body, affect a large set of pathophysiological processes. Changes in the composition and proportion of the microbiome are associated with metabolic diseases (Fulbright et al., PLoS Pathog 13:e1006480, 2017; Maruvada et al., Cell Host Microbe 22:589-599, 2017), psychiatric disorders (Macfabe, Glob Adv Health Med 2:52-66, 2013; Kundu et al., Cell 171:1481-1493, 2017), and neoplastic diseases (Plottel and Blaser, Cell Host Microbe 10:324-335, 2011; Schwabe and Jobin, Nat Rev Cancer 13:800-812, 2013; Zitvogel et al., Cell 165:276-287, 2016). However, the number of directly tumorigenic bacteria is extremely low. Microbial dysbiosis is connected to cancers of the urinary tract (Yu, Arch Med Sci 11:385-394, 2015), cervix (Chase, Gynecol Oncol 138:190-200, 2015), skin (Yu et al., J Drugs Dermatol 14:461-465, 2015), airways (Gui et al., Genet Mol Res 14:5642-5651, 2015), colon (Garrett, Science 348:80-86, 2015), lymphomas (Yamamoto and Schiestl, Int J Environ Res Public Health 11:9038-9049, 2014; Yamamoto and Schiestl, Cancer J 20:190-194, 2014), prostate (Yu, Arch Med Sci 11:385-394, 2015), and breast (Flores et al., J Transl Med 10:253, 2012; Fuhrman et al., J Clin Endocrinol Metab 99:4632-4640, 2014; Xuan et al., PLoS One 9:e83744, 2014; Goedert et al., J Natl Cancer Inst 107:djv147, 2015; Chan et al., Sci Rep 6:28061, 2016; Hieken et al., Sci Rep 6:30751, 2016; Urbaniak et al., Appl Environ Microbiol 82:5039-5048, 2016; Goedert et al., Br J Cancer 118:471-479, 2018). Microbial dysbiosis can influence organs in direct contact with the microbiome and organs that are located at distant sites of the body. The altered microbiota can lead to a disruption of the mucosal barrier (Plottel and Blaser, Cell Host Microbe 10:324-335, 2011), promote or inhibit tumorigenesis through the modification of immune responses (Kawai and Akira, Int Immunol 21:317-337, 2009; Dapito et al., Cancer Cell 21:504-516, 2012) and microbiome-derived metabolites, such as estrogens (Flores et al., J Transl Med 10:253, 2012; Fuhrman et al., J Clin Endocrinol Metab 99:4632-4640, 2014), secondary bile acids (Rowland, Role of the gut flora in toxicity and cancer, Academic Press, London, p x, 517 p., 1988; Yoshimoto et al., Nature 499:97-101, 2013; Xie et al., Int J Cancer 139:1764-1775, 2016; Shellman et al., Clin Otolaryngol 42:969-973, 2017; Luu et al., Cell Oncol (Dordr) 41:13-24, 2018; Miko et al., Biochim Biophys Acta Bioenerg 1859:958-974, 2018), short-chain fatty acids (Bindels et al., Br J Cancer 107:1337-1344, 2012), lipopolysaccharides (Dapito et al., Cancer Cell 21:504-516, 2012), and genotoxins (Fulbright et al., PLoS Pathog 13:e1006480, 2017). Thus, altered gut microbiota may change the efficacy of chemotherapy and radiation therapy (McCarron et al., Br J Biomed Sci 69:14-17, 2012; Viaud et al., Science 342:971-976, 2013; Montassier et al., Aliment Pharmacol Ther 42:515-528, 2015; Buchta Rosean et al., Adv Cancer Res 143:255-294, 2019). Taken together, microbial dysbiosis has intricate connections with neoplastic diseases; hereby, we aim to highlight the major contact routes.


Assuntos
Microbiota , Neoplasias/patologia , Microambiente Tumoral , Humanos
6.
Prenat Diagn ; 39(7): 505-518, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30980413

RESUMO

OBJECTIVE: The aim of this study was to establish the diagnostic accuracy of high-field magnetic resonance imaging (MRI) at 7 Tesla (T) compared with that of stereomicroscopic autopsy for assessing first trimester fetuses. METHODS: Nine consecutive cases of first trimester fetuses resulting from spontaneous and therapeutic pregnancy termination were considered. The cases were divided into two groups according to gestational age: the Embryo Group with cases of nine to 10 gestational weeks (GWs) and the Fetus Group with cases of 13 GWs. The first group was scanned using three-dimensional fast imaging with steady state precession (3D FISP), and the second group was scanned using a two-dimensional (2D) turbo spin-echo high-resolution T2-weighted imaging (T2 WI) protocol. A radiologist and two embryologists interpreted the images. All cases were evaluated by invasive autopsy, with pathologist blinded to the imaging results. In total, the database included 270 items for evaluation (9 cases × 30 structures/case). RESULTS: The global agreement between fetal high-field virtopsy and microscopic or stereomicroscopic autopsy was evaluated using 225 evaluation items visible by both methods. Overall, using microscopic examination and stereomicroscopic autopsy as the gold standard, fetal high-field virtopsy had a sensitivity of 94.6% [95% CI, 87.2-98.3] and a specificity of 97.6% [95% CI, 95-98.8]. The positive predictive value (PPV) was 93% [95% CI, 85.7-96.6], and the negative predictive value (NPV) was 98.2% [95% CI, 95.7-99.4]. Cohen kappa coefficient of agreement was k = 0.92 [95% CI, 0.82-0.97], and the McNemar test showed p = 1.00. CONCLUSIONS: Virtual autopsy using high-field MRI at 7 T can be considered a safe alternative approach to stereomicroscopic autopsy for the assessment of fetal structural anomalies at the end of the first trimester of pregnancy.


Assuntos
Feto Abortado/patologia , Feto/patologia , Imageamento por Ressonância Magnética/métodos , Microscopia/métodos , Primeiro Trimestre da Gravidez , Feto Abortado/diagnóstico por imagem , Autopsia/métodos , Percepção de Profundidade , Feminino , Morte Fetal , Feto/diagnóstico por imagem , Idade Gestacional , Humanos , Imageamento Tridimensional/métodos , Valor Preditivo dos Testes , Gravidez , Sensibilidade e Especificidade
7.
Biochim Biophys Acta Bioenerg ; 1859(9): 958-974, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29655782

RESUMO

Our study aimed at finding a mechanistic relationship between the gut microbiome and breast cancer. Breast cancer cells are not in direct contact with these microbes, but disease could be influenced by bacterial metabolites including secondary bile acids that are exclusively synthesized by the microbiome and known to enter the human circulation. In murine and bench experiments, a secondary bile acid, lithocholic acid (LCA) in concentrations corresponding to its tissue reference concentrations (< 1 µM), reduced cancer cell proliferation (by 10-20%) and VEGF production (by 37%), aggressiveness and metastatic potential of primary tumors through inducing mesenchymal-to-epithelial transition, increased antitumor immune response, OXPHOS and the TCA cycle. Part of these effects was due to activation of TGR5 by LCA. Early stage breast cancer patients, versus control women, had reduced serum LCA levels, reduced chenodeoxycholic acid to LCA ratio, and reduced abundance of the baiH (7α/ß-hydroxysteroid dehydroxylase, the key enzyme in LCA generation) gene in fecal DNA, all suggesting reduced microbial generation of LCA in early breast cancer.


Assuntos
Apoptose/efeitos dos fármacos , Bactérias/metabolismo , Neoplasias da Mama/tratamento farmacológico , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Detergentes/farmacologia , Ácido Litocólico/farmacologia , Animais , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Prognóstico , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
8.
Biochem Biophys Res Commun ; 464(1): 189-94, 2015 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-26116539

RESUMO

We have previously presented co-expression of the plasma membrane calcium ATPase isoforms 4b (PMCA4b) and 1b (PMCA1b) in colon carcinoma cells, and selective upregulation of PMCA4b during differentiation initiated by short chain fatty acids or post-confluent growth. Here we show that the induction of PMCA4b expression is a characteristic feature of the post-confluency-induced differentiation of both enterocyte-type and goblet cell-type colon cancer cells. Vitamin D3 (1,25(OH)2D3) is a well-known regulator of intestinal Ca(2+) absorption and of basic cell functions such as growth and differentiation in various cell types. As PMCA proteins are involved both in intestinal Ca(2+) absorption and adenocarcinoma cell differentiation, we investigated the effect of 1,25(OH)2D3 on PMCA expression in enterocyte-like colon carcinoma cells, and monitored its effect on the expression of various differentiation markers. 1,25(OH)2D3 stimulated PMCA1b, but not PMCA4b expression without modulating the expression of the majority of the differentiation markers examined. Caco-2 cells differentiated in post-confluent cultures present normal enterocyte-like intestinal epithelial phenotype. To better understand the role of PMCA proteins in vectorial Ca(2+) transport by enterocytes, we also studied their subcellular localization in mature polarized Caco-2 cells. Both PMCA isoforms were located to the basolateral membrane, and the PMCA-specific immunofluorescent signal was significantly higher in vitamin D3-treated cells, underlining the 1,25(OH)2D3-induced upregulation of PMCA (presumably 1b isoform) expression in differentiated Caco-2 cells. We suggest that while PMCA1b has a housekeeping function in colon cancer cells, PMCA4b participates in the reorganization of the Ca(2+) signalling machinery during cell differentiation. The subcellular localization of PMCA1b and its selective 1,25(OH)2D3-dependent upregulation indicate that this isoform may have a specific role in 1,25(OH)2D3-stimulated intestinal Ca(2+) absorption.


Assuntos
Calcitriol/farmacologia , Cálcio/metabolismo , Regulação Neoplásica da Expressão Gênica , ATPases Transportadoras de Cálcio da Membrana Plasmática/metabolismo , Células CACO-2 , Sinalização do Cálcio , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Polaridade Celular , Ativação Enzimática/efeitos dos fármacos , Células HT29 , Humanos , Fenótipo , ATPases Transportadoras de Cálcio da Membrana Plasmática/genética , Ativação Transcricional/efeitos dos fármacos
9.
Materials (Basel) ; 17(13)2024 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-38998424

RESUMO

The energy-absorbing capacity and friction phenomena of different closed-cell aluminium foam-filled Al tube types are investigated through experimental compression tests. Concerning the kind of investigation, free, radial-constrained and friction tests occurred. The radial-constrained compression test results confirm that the process requires significantly more compression energy than without the constrain. Pushing away different pre-compressed foams inside the aluminium tube, the static and kinematic frictional resistances can be determined and the energy required to move them can be calculated. Knowing the value of the energy required for the frictional resistance, we can obtain how much of the energy surplus in radially inhibited compression is caused by the friction phenomena. The main goal present study is to reveal the magnitude of friction between the foam and the wall of the tube during the radially constrained test. The investigation used 0.4 and 0.7 g/cm3 density closed-cell aluminium foam whilst a compressive test was applied where the force-displacement data were recorded to calculate the absorbed energy due to friction. Considering the results of the test, it can be stated that 18% of the invested energy was used to overcome friction in the case of lighter foam and almost 23% with 0.7 g/cm3 foam during the radial-constrained test.

10.
JCI Insight ; 9(17)2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-39042472

RESUMO

Alveolar macrophages (AMs) act as gatekeepers of the lung's immune responses, serving essential roles in recognizing and eliminating pathogens. The transcription factor (TF) early growth response 2 (EGR2) has been recently described as required for mature AMs in mice; however, its mechanisms of action have not been explored. Here, we identified EGR2 as an epigenomic regulator and likely direct proximal transcriptional activator in AMs using epigenomic approaches (RNA sequencing, ATAC sequencing, and CUT&RUN). The predicted direct proximal targets of EGR2 included a subset of AM identity genes and ones related to pathogen recognition, phagosome maturation, and adhesion, such as Clec7a, Atp6v0d2, Itgb2, Rhoc, and Tmsb10. We provided evidence that EGR2 deficiency led to impaired zymosan internalization and reduced the capacity to respond to Aspergillus fumigatus. Mechanistically, the lack of EGR2 altered the transcriptional response, secreted cytokines (i.e., CXCL11), and inflammation-resolving lipid mediators (i.e., RvE1) of AMs during in vivo zymosan-induced inflammation, which manifested in impaired resolution. Our findings demonstrated that EGR2 is a key proximal transcriptional activator and epigenomic bookmark in AMs responsible for select, distinct components of cell identity and a protective transcriptional and epigenomic program against fungi.


Assuntos
Aspergillus fumigatus , Proteína 2 de Resposta de Crescimento Precoce , Macrófagos Alveolares , Fagocitose , Animais , Macrófagos Alveolares/imunologia , Macrófagos Alveolares/metabolismo , Proteína 2 de Resposta de Crescimento Precoce/genética , Proteína 2 de Resposta de Crescimento Precoce/metabolismo , Proteína 2 de Resposta de Crescimento Precoce/imunologia , Camundongos , Fagocitose/imunologia , Fagocitose/genética , Aspergillus fumigatus/imunologia , Camundongos Knockout , Camundongos Endogâmicos C57BL , Epigenômica , Epigênese Genética/imunologia , Zimosan
11.
Methods Mol Biol ; 2609: 227-249, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36515839

RESUMO

PARP enzymes are involved in metabolic regulation and impact on a plethora of cellular metabolic pathways, among them, mitochondrial oxidative metabolism. The detrimental effects of PARP1 overactivation upon oxidative stress on mitochondrial oxidative metabolism was discovered in 1998. Since then, there was an enormous blooming in the understanding of the interplay between PARPs and mitochondria. Mitochondrial activity can be assessed by a comprehensive set of methods that we aim to introduce here.


Assuntos
Respiração Celular , Mitocôndrias , Mitocôndrias/metabolismo , Oxirredução , Estresse Oxidativo
12.
Polymers (Basel) ; 15(6)2023 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-36987367

RESUMO

Three-dimensional printing is a useful and common process in additive manufacturing nowadays. The advantage of additive polymer technology is its rapidity and design freedom. Polymer materials' mechanical properties depend on the process parameters and the chemical composition of the polymer used. Mechanical properties are very important in product applicability. The mechanical properties of polymers can be enhanced by heat treatment. Additive-manufactured PLA's mechanical properties and structure can be modified via heat treatment after the 3D printing process. The goal of this research was to test the effect of heat treatment on the mechanical and structural parameters of additive-manufactured PLA. This was achieved via the FDM processing of standard PLA tensile test specimens with longitudinal and vertical printing orientations. After printing, the test specimens were heat-treated at 55 °C, 65 °C and 80 °C for 5 h and after being held at 20 °C for 15 h. The printed and heat-treated specimens were tested using tensile tests and microscopy. Based on the test results, we can conclude that the optimal heat treatment process temperature was 65 °C for 5 h. Under the heat treatment, the test specimens did not show any deformation, the tensile strength increased by 35% and the porosity of the PLA structure decreased.

13.
Materials (Basel) ; 16(11)2023 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-37297122

RESUMO

This work aimed to comprehensively evaluate the influence of different surface modifications on the surface roughness of Ti6Al4V alloys produced by selective laser melting (SLM), casting and wrought. The Ti6Al4V surface was treated using blasting with Al2O3 (70-100 µm) and ZrO2 (50-130 µm) particles, acid etching with 0.017 mol/dm3 hydrofluoric acids (HF) for 120 s, and a combination of blasting and acid etching (SLA). It was found that the optimization of the surface roughness of Ti6Al4V parts produced by SLM differs significantly from those produced by casting or wrought processes. Experimental results showed that Ti6Al4V alloys produced by SLM and blasting with Al2O3 followed by HF etching had a higher surface roughness (Ra = 2.043 µm, Rz = 11.742 µm), whereas cast and wrought Ti6Al4V components had surface roughness values of (Ra = 1.466, Rz = 9.428 m) and (Ra = 0.940, Rz = 7.963 m), respectively. For Ti6Al4V parts blasted with ZrO2 and then etched by HF, the wrought Ti6Al4V parts exhibited higher surface roughness (Ra = 1.631 µm, Rz = 10.953 µm) than the SLM Ti6Al4V parts (Ra = 1.336 µm, Rz = 10.353 µm) and the cast Ti6Al4V parts (Ra = 1.075 µm, Rz = 8.904 µm).

14.
Materials (Basel) ; 15(5)2022 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-35269207

RESUMO

Ti6Al4V (Ti64) alloys manufactured by selective laser melting (SLM) are well known for their susceptibility to failure at a low ductility of less than 10% due to the formation of an (α') martensitic structure. Annealing and solution treatments as post-heat treatments of α' are considered a good way to improve the mechanical performance of SLM-manufactured Ti64 parts. In this research, the effect of heat treatment parameters such as temperature (850 °C and 1020 °C) and cooling rate (furnace and water cooling) on the microstructure and mechanical properties of the SLM Ti64 structure was investigated. It was shown that the tensile strength/ductility of the Ti64 alloy produced by SLM was determined by the post-heat treatment. The experimental results revealed that heat treatment at 850 °C followed by furnace cooling resulted in the best possible combination of ductility (13%) and tensile strength (σy = 932, σu = 986 MPa) with a microstructure consisting mainly of 78.71% α and 21.29% ß. Heat treatment at 850 °C followed by water cooling was characterized by a reduction in hardness and the formation of predominantly α plus α'' and a small amount of ß. HT850WC exhibited yield and tensile strengths of about 870 and 930 MPa, respectively, and an elongation at fracture of 10.4%. Heat treatment at 1020 °C and subsequent cooling in the furnace was characterized by the formation of an α + ß lamellar microstructure. In contrast, heat treatment at 1020 °C and subsequent water cooling formed semi-equiaxial ß grains of about 170 µm in diameter with longer elongated α grains and basket-weave α'. Post-treatment at 1020 °C followed by furnace cooling showed high ductility with an elongation of 14.5% but low tensile strength (σy = 748, σu = 833 MPa). In contrast, post-treatment at 1020 °C followed by water cooling showed poor ductility with elongation of 8.6% but high tensile strength (σy = 878, σu = 990 MPa). The effect of aging at 550 °C for 3 h and cooling in a furnace on the microstructure and mechanical properties of the specimens cooled with water was also studied. It was found that aging influenced the microstructure of the Ti6Al4V parts, including ß, α, and α″ precipitation and fragmentation or globularization of elongated α grains. The aging process at 550 °C leads to an increase in tensile strength and a decrease in ductility.

15.
Exp Ther Med ; 23(1): 102, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34976144

RESUMO

Severe acute respiratory distress syndrome with coronavirus 2 (SARS-CoV-2) infection affected pregnant women during the pandemic. Immunological particularity of this population and the increased need for medical assistance placed this population in a high-risk category for SARS-Cov-2 infection. Owing to high contamination risk and limited studies regarding vertical transmission, the labor and delivery of positive women required particular conditions. Cesarean section probably proved to be the optimal option for delivery of infants to reduce the risk of infection during birth. The aim of the present study was to present the management and outcome of infants born to mothers confirmed with coronavirus disease 2019 (COVID 19) prior to delivery. This is a longitudinal, retrospective study, analyzing demographics, laboratory data and management of neonates born to mothers with diagnosis of SARS-Cov-2 infection. The results showed that 5 neonates were born to SARS-Cov-2-positive mothers, all by Cesarean section and had a negative reverse transcription-quantitative polymerase chain reaction (RT-qPCR) test. None of the women breastfed during the hospital stay. The negative RT-qPCR test allowed us to reduce the hospital stay of infants and care in non-isolated areas. In summary, in the present study, vertical or perinatal transmission of the infection was not present. The testing of the pregnant women, their isolation and delivery in safe conditions for the medical staff were possible, with the latter using adequate protection equipment to limit their infection and the risk for the newborns.

16.
J Matern Fetal Neonatal Med ; 35(25): 7290-7295, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34470118

RESUMO

Krukenberg's tumor diagnosed in pregnancy is an uncommon situation that raises both diagnosis and medical management issues. We performed a review of the existing literature regarding this pathology, diagnostic means and therapeutic approaches, motivated by a case in our own practice. A 35-year-old primigravida was diagnosed with an adnexal mass during the first trimester prenatal ultrasound. Ultrasound revealed a 10 cm right adnexal mass with multiple septae, richly vascularized, whose presence and characteristics were confirmed by magnetic resonance imaging. Due to the progressively increasing tumor size, laparoscopy was performed with right adnexectomy and peritoneal biopsies. Histopathology diagnosed a metastatic ovarian tumor from a mucinous colorectal adenocarcinoma. After delivery the patient was further investigated and diagnosed with sigmoid cancer. Even though ovarian cancer in pregnancy is rare, adnexal ultrasound is mandatory when scanning during the first trimester to rule out the presence of associated fallopian or ovarian masses.


Assuntos
Doenças dos Anexos , Tumor de Krukenberg , Neoplasias Ovarianas , Gravidez , Feminino , Humanos , Adulto , Tumor de Krukenberg/diagnóstico por imagem , Tumor de Krukenberg/cirurgia , Doenças dos Anexos/diagnóstico , Doenças dos Anexos/patologia , Neoplasias Ovarianas/diagnóstico por imagem , Neoplasias Ovarianas/cirurgia , Primeiro Trimestre da Gravidez , Imageamento por Ressonância Magnética
17.
Injury ; 52 Suppl 1: S44-S47, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32571546

RESUMO

INTRODUCTION: Periprosthetic fractures (PPFx) occur more and more often following joint replacement. The aim of this study was to investigate the functional outcome of patients treated with lower limb periprosthetic fractures in our institution. METHODS: Between 2007 and 2016 75 patients were managed with 13 intraoperative and 62 postoperative fractures. Fifty-nine fractures occurred around THR and 16 around TKR. Fractures were classified according to Unified Classification System (UCS) and the treatment was according to this algorithm. Functional outcome was assessed with the Harris Hip Scores and the Knee Society Score (KSS). RESULTS: Follow up time was 52.9 months (range 12-100 m.). The mean age of patients was 75.1 years (range 54-87 years), there were 6 males and 69 females. Harris Hip Scores were available for 42 patients and the average score was 82 (range 68-96). The KSS was available in nine patients and the average score was 124 (range 102-141). Eventually, radiographic union was observed in all cases. CONCLUSION: In this series of patients, fixation of lower limb periprosthetic fractures was found to be associated with good results despite the different fracture patterns studied. Larger studies with subgroup analysis of different fracture patterns are desirable to throw more light in this complex group of patients.


Assuntos
Artroplastia de Quadril , Fraturas do Fêmur , Fraturas Periprotéticas , Idoso , Idoso de 80 Anos ou mais , Artroplastia de Quadril/efeitos adversos , Feminino , Fraturas do Fêmur/cirurgia , Fixação Interna de Fraturas , Humanos , Articulação do Joelho , Extremidade Inferior/diagnóstico por imagem , Extremidade Inferior/cirurgia , Masculino , Pessoa de Meia-Idade , Fraturas Periprotéticas/diagnóstico por imagem , Fraturas Periprotéticas/cirurgia , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
18.
Cells ; 10(6)2021 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-34199944

RESUMO

PARP2 is a DNA repair protein. The deletion of PARP2 induces mitochondrial biogenesis and mitochondrial activity by increasing NAD+ levels and inducing SIRT1 activity. We show that the silencing of PARP2 causes mitochondrial fragmentation in myoblasts. We assessed multiple pathways that can lead to mitochondrial fragmentation and ruled out the involvement of mitophagy, the fusion-fission machinery, SIRT1, and mitochondrial unfolded protein response. Nevertheless, mitochondrial fragmentation was reversed by treatment with strong reductants, such as reduced glutathione (GSH), N-acetyl-cysteine (NAC), and a mitochondria-specific antioxidant MitoTEMPO. The effect of MitoTEMPO on mitochondrial morphology indicates the production of reactive oxygen species of mitochondrial origin. Elimination of reactive oxygen species reversed mitochondrial fragmentation in PARP2-silenced cells.


Assuntos
Inativação Gênica , Mitocôndrias , Dinâmica Mitocondrial/genética , Poli(ADP-Ribose) Polimerases , Espécies Reativas de Oxigênio/metabolismo , Células Hep G2 , Humanos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Poli(ADP-Ribose) Polimerases/genética , Poli(ADP-Ribose) Polimerases/metabolismo , Sirtuína 1/genética , Sirtuína 1/metabolismo
19.
Biochim Biophys Acta ; 1788(3): 587-99, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19135027

RESUMO

The SERCA family includes 3 genes (SERCA1-3), each of which giving rise to various isoforms. To date, detailed structural data is only available for the SERCA1a isoform. Here, limited trypsinolysis of either human platelet membranes or recombinant SERCA3a in HEK-293 cells followed by Western blotting using antibodies covering different regions of the SERCA3(a) protein revealed two, kinetically distinct, Early (ETF) and Late (LTF) Tryptic Fragmentations. The ETF uses many tryptic sites while the LTF uses a unique tryptic site. Using site-directed mutagenesis: i) Arg(334), Arg(396) and Arg(638) were directly assigned to the ETF and ii) Arg(198) was assigned as the only tryptic site to the LTF. Arg(671), Lys(712)/Lys(713) and Lys(728) were also found to modulate the ETF. SERCA inhibitors Tg and tBHQ induced modest inhibition of the ETF. In contrast, the addition of CaCl(2), EGTA or AlF(4)(-) strikingly modified the ETF without any effect on the LTF. Trypsinolysis of the other recombinant SERCA3b-3f isoforms revealed: i) same ETF and LTF as SERCA3a, with variations of the length of the C-terminal fragments; ii) Arg(1002) as an additional tryptic site in SERCA3b-3e isoforms. Taken together, the two distinct SERCA3 fragmentation profiles sign the co-expression of SERCA3 proteins in two conformational states in cell membranes.


Assuntos
ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/biossíntese , Compostos de Alumínio/farmacologia , Sequência de Aminoácidos , Plaquetas/enzimologia , Cálcio/farmacologia , Linhagem Celular , Membrana Celular/enzimologia , Ácido Egtázico/farmacologia , Retículo Endoplasmático , Fluoretos/farmacologia , Humanos , Hidroquinonas/farmacologia , Isoenzimas/biossíntese , Isoenzimas/genética , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Conformação Proteica , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/antagonistas & inibidores , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , Tapsigargina/farmacologia , Tripsina/metabolismo
20.
Antioxid Redox Signal ; 33(13): 966-997, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31989830

RESUMO

Significance: Nuclear factor erythroid 2 (NFE2)-related factor 2 (NFE2L2, or NRF2) is a transcription factor predominantly affecting the expression of antioxidant genes. NRF2 plays a significant role in the control of redox balance, which is crucial in cancer cells. NRF2 activation regulates numerous cancer hallmarks, including metabolism, cancer stem cell characteristics, tumor aggressiveness, invasion, and metastasis formation. We review the molecular characteristics of the NRF2 pathway and discuss its interactions with the cancer hallmarks previously listed. Recent Advances: The noncanonical activation of NRF2 was recently discovered, and members of this pathway are involved in carcinogenesis. Further, cancer-related changes (e.g., metabolic flexibility) that support cancer progression were found to be redox- and NRF2 dependent. Critical Issues: NRF2 undergoes Janus-faced behavior in cancers. The pro- or antineoplastic effects of NRF2 are context dependent and essentially based on the specific molecular characteristics of the cancer in question. Therefore, systematic investigation of NRF2 signaling is necessary to clarify its role in cancer etiology. The biggest challenge in the NRF2 field is to determine which cancers can be targeted for better clinical outcomes. Further, large-scale genomic and transcriptomic studies are missing to correlate the clinical outcome with the activity of the NRF2 system. Future Directions: To exploit NRF2 in a clinical setting in the future, the druggable members of the NRF2 pathway should be identified. In addition, it will be important to study how the modulation of the NRF2 system interferes with cytostatic drugs and their combinations.


Assuntos
Metabolismo Energético , Redes e Vias Metabólicas , Fator 2 Relacionado a NF-E2/metabolismo , Neoplasias/etiologia , Neoplasias/metabolismo , Animais , Antioxidantes/metabolismo , Biomarcadores Tumorais , Epigênese Genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Hormônios/metabolismo , Humanos , MicroRNAs/genética , Mutação , Fator 2 Relacionado a NF-E2/genética , Neoplasias/patologia , Células-Tronco Neoplásicas/metabolismo , Oxirredução , Estresse Oxidativo , Transdução de Sinais/efeitos dos fármacos , Resposta a Proteínas não Dobradas
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