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1.
J Clin Biochem Nutr ; 71(3): 191-197, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36447486

RESUMO

Nitric oxide and reactive oxygen species regulate bone remodeling, which occurs via bone formation and resorption by osteoblasts and osteoclasts, respectively. Recently, we found that 8-nitro-cGMP, a second messenger of nitric oxide and reactive oxygen species, promotes osteoclastogenesis. Here, we investigated the formation and function of 8-nitro-cGMP in osteoblasts. Mouse calvarial osteoblasts were found to produce 8-nitro-cGMP, which was augmented by tumor necrosis factor-α (10 ng/ml) and interleukin-1ß (1 ng/ml). These cytokines suppressed osteoblastic differentiation in a NO synthase activity-dependent manner. Exogenous 8-nitro-cGMP (30 µmol/L) suppressed expression of osteoblastic phenotypes, including mineralization, in clear contrast to the enhancement of mineralization by osteoblasts induced by 8-bromo-cGMP, a cell membrane-permeable analog of cGMP. It is known that reactive sulfur species denitrates and degrades 8-nitro-cGMP. Mitochondrial cysteinyl-tRNA synthetase plays a crucial role in the endogenous production of RSS. The expression of osteoblastic phenotypes was suppressed by not only exogenous 8-nitro-cGMP but also by silencing of the Cars2 gene, indicating a role of endogenous 8-nitro-cGMP in suppressing the expression of osteoblastic phenotypes. These results suggest that 8-nitro-cGMP is a negative regulator of osteoblastic differentiation.

3.
Cell Tissue Res ; 368(1): 135-144, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28070636

RESUMO

Osteoarthritis is a degenerative joint disease caused by excessive death of chondrocytes and loss of the extracellular matrix (ECM) in articular cartilage. We previously reported that reactive oxygen species (ROS) generated by the NADPH oxidase (NOX) isoform NOX-2 are involved in chondrocyte death induced by interleukin-1ß (IL-1ß). In this study, we investigate the role of NOX-2 in the production and degradation of ECM by chondrocytes. Although IL-1ß lowered the mRNA expression of type II collagen (Col2a1) and aggrecan (Acan) in mouse chondrocyte-like ATDC5 cells, RNA silencing of Nox2 did not change the mRNA expression of these major components of the ECM of cartilage. Hence, NOX-2 is not involved in the IL-1ß-induced suppression of ECM production. On the other hand, the NOX inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), the ROS scavenger N-acetylcysteine and an antisense oligodeoxynucleotide for Nox2 prevented the loss of proteoglycan induced by IL-1ß in highly differentiated ATDC5 cells. Furthermore, AEBSF did not affect the expression of hyaluronidase-1 and -2, whereas it suppressed hyaluronidase activity in culture medium. IL-1ß-induced intra- and extracellular acidification was also suppressed by AEBSF, as was the antisense oligodeoxynucleotide for Nox2. Since hyaluronidase activity is known to be higher under acidic conditions, NOX-2 probably contributes to ECM loss by the activation of hyaluronidase through acidification.


Assuntos
Condrócitos/metabolismo , Matriz Extracelular/metabolismo , Interleucina-1beta/farmacologia , NADPH Oxidases/metabolismo , Acetilcisteína/farmacologia , Ácidos/metabolismo , Agrecanas/genética , Agrecanas/metabolismo , Células Cultivadas , Condrócitos/efeitos dos fármacos , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Meios de Cultura/farmacologia , Inibidores Enzimáticos/farmacologia , Matriz Extracelular/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Ácido Hialurônico/metabolismo , Hialuronoglucosaminidase/metabolismo , Concentração de Íons de Hidrogênio , Proteoglicanas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Sulfonas/farmacologia
4.
Biochem Biophys Res Commun ; 473(2): 537-44, 2016 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-27018251

RESUMO

It is known that diabetes aggravates alveolar bone loss associated with periodontitis. While insulin depletion increases the blood concentration of ketone bodies, i.e., acetoacetate and ß-hydroxybutyrate, their roles in bone metabolism have not been much studied until today. We investigated the effects of acetoacetate and ß-hydroxybutyrate on mineralization of extracellular matrix in cultures of mouse osteoblastic MC3T3-E1 cells and primary mouse osteoblasts in the presence and absence of bone morphogenetic protein-2. Acetoacetate potentiated alkaline phosphatase activity in MC3T3-E1 cells in a concentration-dependent manner, ranging from physiological to pathological concentrations (0.05-5 mmol/L). In contrast, ß-hydroxybutyrate lowered it in the same experimental settings. Mineralization in cultures of these cells was also up-regulated by acetoacetate and down-regulated by ß-hydroxybutyrate. Similar results were obtained in cultures of mouse primary osteoblasts. Neither alkaline phosphatase mRNA nor its protein expression in MC3T3-E1 cells was affected by acetoacetate or ß-hydroxybutyrate, indicating that these ketone bodies control the enzyme activity of alkaline phosphatase in osteoblasts and hence their mineralization bi-directionally. Finally, either gene silencing of monocarboxylate transporter-1, a major transmembrate transporter for ketone bodies, nullified the effects of ketone bodies on alkaline phosphatase activity in MC3T3-E1 cells. Collectively, we found that ketone bodies bidirectionally modulates osteoblast functions, which suggests that ketone bodies are important endogenous factors that regulate bone metabolism in both physiological and pathological situations.


Assuntos
Ácido 3-Hidroxibutírico/metabolismo , Acetoacetatos/metabolismo , Fosfatase Alcalina/metabolismo , Calcificação Fisiológica , Corpos Cetônicos/metabolismo , Osteoblastos/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Camundongos , Osteoblastos/citologia
5.
Development ; 140(17): 3680-90, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23903192

RESUMO

It has been suggested that during mouse preimplantation development, the zygotically expressed transcription factor TEAD4 is essential for specification of the trophectoderm lineage required for producing a blastocyst. Here we show that blastocysts can form without TEAD4 but that TEAD4 is required to prevent oxidative stress when blastocoel formation is accompanied by increased oxidative phosphorylation that leads to the production of reactive oxygen species (ROS). Both two-cell and eight-cell Tead4(-/-) embryos developed into blastocysts when cultured under conditions that alleviate oxidative stress, and Tead4(-/-) blastocysts that formed under these conditions expressed trophectoderm-associated genes. Therefore, TEAD4 is not required for specification of the trophectoderm lineage. Once the trophectoderm was specified, Tead4 was not essential for either proliferation or differentiation of trophoblast cells in culture. However, ablation of Tead4 in trophoblast cells resulted in reduced mitochondrial membrane potential. Moreover, Tead4 suppressed ROS in embryos and embryonic fibroblasts. Finally, ectopically expressed TEAD4 protein could localize to the mitochondria as well as to the nucleus, a property not shared by other members of the TEAD family. These results reveal that TEAD4 plays a crucial role in maintaining energy homeostasis during preimplantation development.


Assuntos
Blastocisto/fisiologia , Proteínas de Ligação a DNA/metabolismo , Desenvolvimento Embrionário/fisiologia , Metabolismo Energético/fisiologia , Homeostase/fisiologia , Proteínas Musculares/metabolismo , Fatores de Transcrição/metabolismo , Animais , Fibroblastos/metabolismo , Imuno-Histoquímica , Potencial da Membrana Mitocondrial/fisiologia , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Transcrição de Domínio TEA , Trofoblastos/metabolismo , Trofoblastos/fisiologia
6.
Stem Cells ; 33(11): 3239-53, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26140583

RESUMO

Geminin is a dual-function protein unique to multicellular animals with roles in modulating gene expression and preventing DNA re-replication. Here, we show that geminin is essential at the beginning of mammalian development to prevent DNA re-replication in pluripotent cells, exemplified by embryonic stem cells, as they undergo self-renewal and differentiation. Embryonic stem cells, embryonic fibroblasts, and immortalized fibroblasts were characterized before and after geminin was depleted either by gene ablation or siRNA. Depletion of geminin under conditions that promote either self-renewal or differentiation rapidly induced DNA re-replication, followed by DNA damage, then a DNA damage response, and finally apoptosis. Once differentiation had occurred, geminin was no longer essential for viability, although it continued to contribute to preventing DNA re-replication induced DNA damage. No relationship was detected between expression of geminin and genes associated with either pluripotency or differentiation. Thus, the primary role of geminin at the beginning of mammalian development is to prevent DNA re-replication-dependent apoptosis, a role previously believed essential only in cancer cells. These results suggest that regulation of gene expression by geminin occurs only after pluripotent cells differentiate into cells in which geminin is not essential for viability.


Assuntos
Apoptose/fisiologia , Diferenciação Celular/fisiologia , Replicação do DNA/fisiologia , Células-Tronco Embrionárias/fisiologia , Geminina/fisiologia , Células-Tronco Pluripotentes/fisiologia , Animais , Sobrevivência Celular/fisiologia , Células Cultivadas , Geminina/deficiência , Camundongos , Camundongos Transgênicos
7.
Dev Biol ; 387(1): 49-63, 2014 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-24412371

RESUMO

Geminin is a protein involved in both DNA replication and cell fate acquisition. Although it is essential for mammalian preimplantation development, its role remains unclear. In one study, ablation of the geminin gene (Gmnn) in mouse preimplantation embryos resulted in apoptosis, suggesting that geminin prevents DNA re-replication, whereas in another study it resulted in differentiation of blastomeres into trophoblast giant cells (TGCs), suggesting that geminin regulates trophoblast specification and differentiation. Other studies concluded that trophoblast differentiation into TGCs is regulated by fibroblast growth factor-4 (FGF4), and that geminin is required to maintain endocycles. Here we show that ablation of Gmnn in trophoblast stem cells (TSCs) proliferating in the presence of FGF4 closely mimics the events triggered by FGF4 deprivation: arrest of cell proliferation, formation of giant cells, excessive DNA replication in the absence of DNA damage and apoptosis, and changes in gene expression that include loss of Chk1 with up-regulation of p57 and p21. Moreover, FGF4 deprivation of TSCs reduces geminin to a basal level that is required for maintaining endocycles in TGCs. Thus, geminin acts both like a component of the FGF4 signal transduction pathway that governs trophoblast proliferation and differentiation, and geminin is required to maintain endocycles.


Assuntos
Fator 4 de Crescimento de Fibroblastos/metabolismo , Geminina/metabolismo , Células Gigantes/metabolismo , Trofoblastos/metabolismo , Animais , Apoptose/genética , Diferenciação Celular , Proliferação de Células , Quinase 1 do Ponto de Checagem , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Inibidor de Quinase Dependente de Ciclina p57/biossíntese , Dano ao DNA/genética , Replicação do DNA/genética , Embrião de Mamíferos/embriologia , Embrião de Mamíferos/metabolismo , Fator 4 de Crescimento de Fibroblastos/genética , Geminina/genética , Regulação da Expressão Gênica no Desenvolvimento , Células Gigantes/citologia , Camundongos , Camundongos Transgênicos , Proteínas Quinases/deficiência , Proteínas Quinases/genética , Interferência de RNA , RNA Interferente Pequeno , Transdução de Sinais , Células-Tronco/citologia , Células-Tronco/metabolismo , Trofoblastos/citologia , Regulação para Cima
8.
Biochem Biophys Res Commun ; 467(1): 146-51, 2015 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-26399683

RESUMO

Bropirimine is a synthetic agonist for toll-like receptor 7 (TLR7). In this study, we investigated the effects of bropirimine on differentiation and bone-resorbing activity of osteoclasts in vitro. Bropirimine inhibited osteoclast differentiation of mouse bone marrow-derived macrophages (BMMs) induced by receptor activator of nuclear factor κB ligand (RANKL) in a concentration-dependent manner. Furthermore, it suppressed the mRNA expression of nuclear factor of activated T-cells, cytoplasmic, calcineurin-dependent 1 (NFATc1), a master transcription factor for osteoclast differentiation, without affecting BMM viability. Bropirimine also inhibited osteoclast differentiation induced in co-cultures of mouse bone marrow cells (BMCs) and mouse osteoblastic UAMS-32 cells in the presence of activated vitamin D3. Bropirimine partially suppressed the expression of RANKL mRNA in UAMS-32 cells induced by activated vitamin D3. Finally, the anti-interferon-ß (IFN-ß) antibody restored RANKL-dependent differentiation of BMMs into osteoclasts suppressed by bropirimine. These results suggest that bropirimine inhibits differentiation of osteoclast precursor cells into osteoclasts via TLR7-mediated production of IFN-ß.


Assuntos
Citosina/análogos & derivados , Interferon beta/biossíntese , Osteoclastos/citologia , Osteoclastos/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Linhagem Celular , Técnicas de Cocultura , Citosina/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Masculino , Glicoproteínas de Membrana/agonistas , Camundongos , Camundongos Endogâmicos C57BL , Osteoclastos/imunologia , Ligante RANK/genética , Ligante RANK/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptor 7 Toll-Like/agonistas
10.
J Pediatr Surg ; 59(4): 610-615, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38163744

RESUMO

PURPOSE: Mid-shaft/proximal (msp) and penoscrotal/scrotal/perineal (pssp) hypospadias treated by urethroplasty (UP) terminating at the corona (UPC) or UP terminating at the tip of the glans (UPG) were compared. METHODS: UP performed at a single institute (n = 234) between 2003 and 2020 were grouped as: msp-UPC (n = 23), msp-UPG (n = 75), pssp-UPC (n = 81), and pssp-UPG (n = 55) to compare data obtained from medical records for post-UP complications (PUC; urethral stenosis, urethrocutaneous fistula, diverticulum formation, and bleeding; n = 234), post-UP uroflowmetry (PUF; average flow rate (Qave), maximum flow rate (Qmax), voiding time (VT), voided volume (VV) and urine flow curves) in 57 UP patients [msp-UPC (n = 5), msp-UPG (n = 12), pssp-UPC (n = 32), pssp-UPG (n = 8)] and 9 controls, and post-UPC esthetics (EST; n = 104). P < 0.05 was considered significant. RESULTS: Mean ages at UP (years) were: msp-UPC (3.1 ± 3.0), msp-UPG (3.3 ± 1.4), pssp-UPC (4.6 ± 2.4), and pssp-UPG (3.4 ± 1.4); p < 0.0001 by ANOVA test. Overall, there were significantly more PUC in pssp-UPG compared with pssp-UPC except for bleeding. Ages at PUF assessment were similar. Mean Qave (mL/s) for pssp-UPG (4.0 ± 1.0) was significantly less than pssp-UPC (5.9 ± 2.5; p < 0.05) and both were significantly less than controls (6.9 ± 1.8; p < 0.05, p < 0.01, respectively). Mean Qmax (mL/s) for pssp-UPC (11.4 ± 4.8) was significantly better than pssp-UPG (7.8 ± 2.3; p < 0.05) and for controls (14.9 ± 4.4) was significantly better than pssp-UPG (7.8 ± 2.3; p < 0.01). All VT (seconds) were similar to controls; all urine flow curves were normal. For EST in UPC (n = 104), 3 cases requested meatal advancement. CONCLUSIONS: UPC may be a valid option for treating pssp hypospadias because of significant differences in PUC/PUF and minimal EST issues compared with UPG. LEVEL OF EVIDENCE: Prognosis Study Level-Ⅱ.


Assuntos
Hipospadia , Procedimentos de Cirurgia Plástica , Masculino , Humanos , Lactente , Hipospadia/cirurgia , Hipospadia/complicações , Resultado do Tratamento , Procedimentos Cirúrgicos Urológicos Masculinos , Uretra/cirurgia , Estética
11.
Clin Dev Immunol ; 2013: 968549, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23956763

RESUMO

T-helper 17 (Th17) cells are characterized by producing interleukin-17 (IL-17, also called IL-17A), IL-17F, IL-21, and IL-22 and potentially TNF- α and IL-6 upon certain stimulation. IL-23, which promotes Th17 cell development, as well as IL-17 and IL-22 produced by the Th17 cells plays essential roles in various inflammatory diseases, such as experimental autoimmune encephalomyelitis, rheumatoid arthritis, colitis, and Concanavalin A-induced hepatitis. In this review, we summarize the characteristics of the functional role of Th17 cells, with particular focus on the Th17 cell-related cytokines such as IL-17, IL-22, and IL-23, in mouse models and human inflammatory diseases.


Assuntos
Citocinas/metabolismo , Inflamação/imunologia , Inflamação/metabolismo , Células Th17/imunologia , Células Th17/metabolismo , Animais , Humanos , Interleucina-17/metabolismo , Interleucina-23/metabolismo , Interleucinas/metabolismo , Interleucina 22
12.
J Oral Maxillofac Surg ; 71(9): 1602.e1-1602.e10, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23611606

RESUMO

PURPOSE: The purpose of this study was to observe long-term osseous healing of the cleavage space between bone fragments after intraoral vertical ramus osteotomy using computed tomographic (CT) values. PATIENTS AND METHODS: CT examinations were performed to observe long-term osseous healing immediately after intraoral vertical ramus osteotomy and at 6 months, 1 year, and 2 years postoperatively. Bone fragments were observed on the interior and lateral sides. CT values between bone fragments were used to measure the range of each point within a 1.7- × 1.7-mm square, and the mean of the measurements was calculated. RESULTS: CT values between bone fragments increased significantly over time at 1 month, 6 months, 1 year, and 2 years after surgery. CONCLUSIONS: Osseous healing in the cleavage between bone fragments after intraoral vertical ramus osteotomy was successful according to CT values.


Assuntos
Mandíbula/diagnóstico por imagem , Osteotomia Mandibular/métodos , Tomografia Computadorizada por Raios X/métodos , Adolescente , Adulto , Fatores Etários , Anatomia Transversal , Remodelação Óssea/fisiologia , Cefalometria/métodos , Estudos de Coortes , Feminino , Seguimentos , Humanos , Técnicas de Fixação da Arcada Osseodentária/instrumentação , Estudos Longitudinais , Masculino , Mandíbula/fisiopatologia , Mandíbula/cirurgia , Prognatismo/cirurgia , Estudos Retrospectivos , Cicatrização/fisiologia , Adulto Jovem
13.
Food Chem Toxicol ; 178: 113876, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37286029

RESUMO

While human milk is considered the optimal source of nutrition for infants for the first six and twelve months of age, with continued benefit of breastfeeding with complementary foods, a safe alternative, nutritionally adequate to support infant growth and development, is necessary. In the United States, the Food and Drug Administration (FDA) establishes the requirements necessary to demonstrate the safety of infant formula within the framework of the Federal Food, Drug, and Cosmetic Act. FDA's Center for Food Safety and Applied Nutrition/Office of Food Additive Safety evaluates the safety and lawfulness of individual ingredients used in infant formula, whereas the Office of Nutrition and Food Labeling oversees the safety of infant formula. Most infant formula ingredients are either from sources with history of safe consumption by infants or are like components in human milk. Information demonstrating the regulatory status of all ingredients is required in submissions for new infant formulas, and ingredient manufacturers often use the Generally Recognized as Safe (GRAS) Notification program to establish ingredient regulatory status. We provide an overview of ingredients used in infant formula evaluated through the GRAS Notification program to highlight trends and discuss the data and information used to reach these GRAS conclusions.


Assuntos
Aditivos Alimentares , Fórmulas Infantis , Lactente , Humanos , Estados Unidos , Inocuidade dos Alimentos , Rotulagem de Alimentos , Estado Nutricional , United States Food and Drug Administration
14.
J Oleo Sci ; 71(1): 67-74, 2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-34880151

RESUMO

Surface pressure (π)-area (A) isotherms were studied to analyze the interactions between a hydrophilic ionic liquid (IL) (ethyl(2-hydroxyethyl)dimethylammonium methanesulfonate) and a pure dipalmitoylphosphatidylcholine (DPPC) film or a DPPC-cholesterol mixed film. When the hydrophilic IL was added to an underlayer solution, the isotherm shifted toward higher areas. Intriguingly, when the hydrophilic IL was added, the packing of the film materials became loose and the elastic modulus decreased, resulting in increased flexibility. This phenomenon was most evident under a cholesterol mole fraction of 0.2. This composition resembles that of cell membranes, which typically comprise phospholipids and cholesterol, suggesting that this hydrophilic IL may be able to interact significantly with biological membranes.


Assuntos
1,2-Dipalmitoilfosfatidilcolina/química , Colesterol/química , Interações Hidrofóbicas e Hidrofílicas , Líquidos Iônicos/química , Fosfolipídeos/química , Membrana Celular/química , Polarização de Fluorescência , Maleabilidade , Pressão , Soluções , Propriedades de Superfície
15.
Surg Case Rep ; 8(1): 136, 2022 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-35852719

RESUMO

BACKGROUND: While thrombosis is a well-known complication of coronavirus disease 2019 (COVID-19) infection, reports on intestinal necrosis due to intestinal ischemia caused by thrombosis are extremely rare. We herein report a case of intestinal necrosis due to multiple thrombosis in a COVID-19 patient. CASE PRESENTATION: The patient was a 64-year-old man. He was admitted to hospital after being diagnosed with COVID-19, the severity was classified as moderate II. Nasal High Flow™ management was conducted along with treatment with tocilizumab, remdesivir, and dexamethasone. Heparin was also administered due to high D-dimer values. As abdominal pain appeared from the 6th day of hospitalization, contrast-enhanced CT was performed, which confirmed multiple thrombosis in the aorta. However, no obvious intestinal ischemia was found. On the 10th day of hospitalization, the patient's abdominal pain was exacerbated. Upon re-evaluation by CT, he was diagnosed with perforative peritonitis due to ileal ischemic necrosis and emergency surgery was performed. Intraoperative examination revealed perforation due to necrosis at multiple sites in the ileum; thus, partial ileectomy was carried out. Pathological findings also revealed discontinuous multiple intestinal necrosis due to the frequent occurrence of thrombosis. Following surgery, the patient recuperated and was discharged after ventilator management and multimodal therapy at the ICU. CONCLUSIONS: Thrombosis due to COVID-19 complications is rare in the intestinal tract, but also occur. Its initial symptoms might not be captured by CT images, therefore caution is required.

16.
Langmuir ; 27(12): 7353-6, 2011 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-21604775

RESUMO

This Letter examines the relationship between the structures of ionic liquids and their water-solubility or osmotic pressure with a number of synthesized quaternary ammonium type ionic liquids and organic salts containing a hydroxyl group as hydrophilic substituted groups on ammonium group cations, and bromide or methylsulfonate as anions. The study found a linear relation between the amount and osmotic pressure of the water-soluble ionic liquids synthesized here, strongly indicating that these water-soluble ionic liquids are perfectly ionized in water like inorganic salts with small diameter ions.

17.
Langmuir ; 27(16): 9671-5, 2011 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-21751777

RESUMO

This letter proposes the use of choline-like hydrophilic ionic liquids (ILs) to visualize hydrous samples (e.g., seaweed and other biological or food samples) for scanning electron microscopy (SEM) observation. Some of the water in the samples was successfully replaced with these ILs, which penetrated the cell membranes. The treated samples did not contract much even after drying. The ILs' ionic conductivity decreased the charging of sample surfaces, and good SEM images were obtained.


Assuntos
Membrana Celular/química , Colina/química , Líquidos Iônicos/química , Microscopia Eletrônica de Varredura/métodos , Membrana Celular/ultraestrutura
18.
J Oleo Sci ; 70(11): 1615-1621, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34645746

RESUMO

In this study, we synthesize hydrophilic amine-based protic ionic liquids (PILs) with hydroxy groups in a cation and different anions. Subsequently, we evaluate the kinetic friction coefficients of iron oxide in aqueous solutions of the PILs under different sliding conditions. Ditriethanolamine malate, triethanolamine lactate, triethanolamine methoxyacetate, and triethanolamine acetate are used as PIL samples in this study. Among them, ditriethanolamine malate exhibits the lowest kinetic friction coefficient. As the number of sliding cycles increases, the excellent lubrication capability remains. Subsequently, we characterize the adsorption of the PILs on an iron oxide surface to investigate the lubrication behavior on the basis of quartz crystal microbalance with dissipation monitoring and force curve data. We expect hydrophilic PILs to be excellent water-soluble lubricants and additives for use in metal surface treatments.


Assuntos
Aminas/química , Ânions/química , Interações Hidrofóbicas e Hidrofílicas , Líquidos Iônicos/síntese química , Lubrificantes/síntese química , Lubrificação , Técnicas de Microbalança de Cristal de Quartzo , Adsorção , Compostos Férricos/química , Líquidos Iônicos/química , Solubilidade , Soluções , Água
19.
J Oleo Sci ; 70(3): 333-339, 2021 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-33583920

RESUMO

We synthesized hydrophilic amine-based protic ionic liquids (PILs) with hydroxy groups in their cations and anions, and characterized their adsorption at a solid (iron-based substrate) / aqueous solution interface. The IL samples employed in this study were triethanolamine lactate, diethanolamine lactate, and monoethanolamine lactate. Quartz crystal microbalance with dissipation monitoring (QCM-D) measurements revealed that the adsorption mass of the hydrophilic PILs was larger than that of the comparative materials, including a non-IL sample (1,2,6-hexanetriol) and an OH-free sample in the cations (triethylamine lactate). Additionally, an increase in the number of hydroxy groups in the cations resulted in an increased adsorption mass. Force curve measurements by atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) measurements proved the high adsorption density of the hydrophilic PILs on the iron-based substrate. A decreased kinetic friction coefficient was also observed in the hydrophilic PIL systems. Moreover, hydrophilic PILs are expected to have potential applications as water-soluble lubricants and additives for metal surface treatments.


Assuntos
Aminas/química , Adsorção , Ânions , Cátions , Etanolamina/química , Etanolaminas/química , Interações Hidrofóbicas e Hidrofílicas , Hidroxilação , Lubrificantes , Solubilidade , Soluções , Água
20.
Bone ; 132: 115216, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31899346

RESUMO

Neutrophils are one of the most abundant leukocytes in the sites of lesion of inflammatory diseases such as periodontitis and rheumatoid arthritis. These diseases are accompanied by bone loss, which worsens the quality of life of the patients. However, the role of neutrophils in the inflammatory bone loss has not been fully investigated. In the present study, we found that human neutrophils enhanced osteoclast differentiation from mouse bone marrow cells co-cultured with mouse osteoblasts in the presence of active vitamin D3. The enhanced osteoclast differentiation was significantly suppressed by elastatinal, a synthetic inhibitor of neutrophil elastase. Also, we found that human neutrophils degraded human recombinant osteoprotegerin (OPG), a decoy receptor for nuclear factor κB (RANK) ligand (RANKL), the essential osteoclast differentiation-inducing factor, expressed by osteoblasts. Degradation of OPG by neutrophils was suppressed by human α1-protease inhibitor, the major endogenous inhibitor of neutrophil elastase. Recombinant human neutrophil elastase degraded human OPG in its death domain-like region. These results indicated that the degradation of OPG by elastase contributed at least in part to the enhanced osteoclast differentiation by neutrophils. There is a possibility that neutrophils play an important role in inflammatory bone loss.


Assuntos
Osteoclastos , Osteoprotegerina , Animais , Proteínas de Transporte , Diferenciação Celular , Glicoproteínas/metabolismo , Humanos , Glicoproteínas de Membrana , Camundongos , Neutrófilos/metabolismo , Osteoclastos/metabolismo , Elastase Pancreática , Qualidade de Vida , Ligante RANK , Receptor Ativador de Fator Nuclear kappa-B , Receptores Citoplasmáticos e Nucleares
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