Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Biol Chem ; 300(6): 107288, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38636662

RESUMO

HCN channels are important for regulating heart rhythm and nerve activity and have been studied as potential drug targets for treating depression, arrhythmia, nerve pain, and epilepsy. Despite possessing unique pharmacological properties, HCN channels share common characteristics in that they are activated by hyperpolarization and modulated by cAMP and other membrane lipids. However, the mechanisms of how these ligands bind and modulate HCN channels are unclear. In this study, we solved structures of full-length human HCN3 using cryo-EM and captured two different states, including a state without any ligand bound and a state with cAMP bound. Our structures reveal the novel binding sites for cholesteryl hemisuccinate in apo state and show how cholesteryl hemisuccinate and cAMP binding cause conformational changes in different states. These findings explain how these small modulators are sensed in mammals at the molecular level. The results of our study could help to design more potent and specific compounds to influence HCN channel activity and offer new therapeutic possibilities for diseases that lack effective treatment.


Assuntos
Microscopia Crioeletrônica , AMP Cíclico , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização , Humanos , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/metabolismo , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/química , Canais Disparados por Nucleotídeos Cíclicos Ativados por Hiperpolarização/genética , AMP Cíclico/metabolismo , Sítios de Ligação , Conformação Proteica , Células HEK293
2.
Environ Res ; 231(Pt 1): 116028, 2023 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-37150383

RESUMO

Landfill leachate concentrate (LLC) is a concentrated waste stream from landfill leachate treatment systems and has been recognized as a key challenge due to its high concentration of salts, heavy metals, organic matters, etc. Improper management of LLC (e.g. reinjection) would exacerbate the performance of upstream treatment processes and pose risks to the surrounding environments near landfill sites. Addressing the challenge and recovering resources from LLC have thus been attracting considerable attention. Although many LLC treatment technologies have been developed, a comprehensive discussion about the challenges still lacks. This review critically evaluates mainstream LLC treatment technologies, namely incineration, coagulation, advanced oxidation, evaporation and solidification/stabilization. We then introduce a geopolymer-based solidification (GS) process as a promising technology owning to its simple casting process and reusable final product and summarize engineering applications in China. Finally, we suggest investigating hybrid systems to minimize LLC production and achieve the on-site reuse of LLC. Collectively, this review provides useful information to guide the selection of LLC treatment technologies and suggests a sustainable alternative for large-scale application, while also highlighting the need of joint efforts in the industry to achieve efficient, ecofriendly and economical on-site management of landfill waste streams.


Assuntos
Metais Pesados , Eliminação de Resíduos , Poluentes Químicos da Água , Poluentes Químicos da Água/análise , Incineração , Instalações de Eliminação de Resíduos , Tecnologia
3.
Mar Drugs ; 19(12)2021 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-34940711

RESUMO

Oxidized low-density lipoprotein (ox-LDL)-induced oxidative injury in vascular endothelial cells is crucial for the progression of cardiovascular diseases, including atherosclerosis. Several flavonoids have been shown cardiovascular protective effects. Recently, our research group confirmed that the novel flavonoids isolated from the deep-sea-derived fungus Arthrinium sp., 2,3,4,6,8-pentahydroxy-1-methylxanthone (compound 1) and arthone C (compound 2) effectively scavenged ROS in vitro. In this study, we further investigated whether these compounds could protect against ox-LDL-induced oxidative injury in endothelial cells and the underlying mechanisms. Our results showed that compounds 1 and 2 inhibited ox-LDL-induced apoptosis and adhesion factors expression in human umbilical vein vascular endothelial cells (HUVECs). Mechanistic studies showed that these compounds significantly inhibited the ROS level increase and the NF-κB nuclear translocation induced by ox-LDL. Moreover, compounds 1 and 2 activated the Nrf2 to transfer into nuclei and increased the expression of its downstream antioxidant gene HO-1 by inducing the phosphorylation of AKT in HUVECs. Importantly, the AKT inhibitor MK-2206 2HCl or knockdown of Nrf2 by RNA interference attenuated the inhibition effects of these compounds on ox-LDL-induced apoptosis in HUVECs. Meanwhile, knockdown of Nrf2 abolished the effects of the compounds on ox-LDL-induced ROS level increase and the translocation of NF-κB to nuclei. Collectively, the data showed that compounds 1 and 2 protected endothelial cells against ox-LDL-induced oxidative stress through activating the AKT/Nrf2/HO-1 pathway. Our study provides new strategies for the design of lead compounds for related cardiovascular diseases treatment.


Assuntos
Antioxidantes/farmacologia , Ascomicetos , Flavonoides/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/química , Organismos Aquáticos , Endotélio Vascular/efeitos dos fármacos , Flavonoides/química , Heme Oxigenase-1/metabolismo , Humanos , Lipoproteínas LDL/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
4.
Bioorg Med Chem Lett ; 30(4): 126925, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31901379

RESUMO

A series of novel indole-pyrazoline hybrid derivatives were designed, synthesized, and evaluated for topoisomerase 1 (Top1) inhibitory activity. Top1-mediated relaxation assays showed that our synthesized compounds had variable Top1 inhibitory activity. Among these compounds, 3-(5-(naphthalen-1-yl)-1-phenyl-4,5-dihydro-1H-pyrazol-3-yl)-1-(phenylsulfonyl)-1H-indole (6n) was found to be a strong Top1 inhibitor with better inhibitory activity than CPT and hit compounds. Our further experiments rationalized the mode of action for this new type of inhibitors, which showed no significant binding to supercoiled DNA.


Assuntos
DNA Topoisomerases Tipo I/química , Indóis/química , Pirazóis/química , Inibidores da Topoisomerase I/síntese química , Sítios de Ligação , DNA Topoisomerases Tipo I/metabolismo , DNA Super-Helicoidal/química , DNA Super-Helicoidal/metabolismo , Desenho de Fármacos , Humanos , Simulação de Dinâmica Molecular , Relação Estrutura-Atividade , Inibidores da Topoisomerase I/metabolismo
5.
Oral Dis ; 25(1): 108-116, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30216606

RESUMO

OBJECTIVES: The present study was to investigate the association between fecal hemoglobin (f-Hb) concentration and oral cancer and its precursor, oral potentially malignant disorders (OPMD). METHODS: We used a population-based longitudinal cohort study data based on both Taiwanese nationwide oral and colorectal cancer screening programs implemented between 2004 and 2009. The total of 235,234 smokers and/or betel-quid chewers aged 50 to 69 years free of oral cancer and OPMD at entry were followed up over time to quantify the association between baseline f-Hb concentration on newly diagnosed oral cancer and OPMD. RESULTS: The risk of OPMD increased with baseline f-Hb in a dose manner, yielding a statistically significant elevated risk of developing OPMD in parallel with the incremental concentration of f-Hb (adjusted hazard ratios = 0.99, 1,11, 1,07, 1,57, and 1,63 for f-Hb categories of 1-9, 10-19, 20-49, 50-89, and ≥90 µg Hb/g, respectively, as compared with the reference group (low and undetectable f-Hb concentrations)) However, there was lacking of a statistical significance for the corresponding association regarding the risk of oral cancer, which is possibly due to sparse cases given a shorter follow-up time. CONCLUSION: We discovered that f-Hb concentration was positively related to the risk of OPMD. f-Hb can be used as a biomarker for early detection of OPMD.


Assuntos
Detecção Precoce de Câncer , Fezes/química , Hemoglobinas/análise , Neoplasias Bucais/diagnóstico , Idoso , Areca , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco
6.
J Pineal Res ; 64(3)2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29274168

RESUMO

Periodontitis (PD) is an inflammatory disease characterized by gingival inflammation and resorption of alveolar bone. Impaired receptor activator of nuclear factor-kappa B ligand/osteoprotegerin (RANKL/OPG) signaling caused by enhanced production of pro-inflammatory cytokines plays an essential role in the pathogenesis of PD. Considering melatonin possesses significant anti-inflammatory property, this study aimed to determine whether prophylactic treatment with melatonin would effectively normalize RANKL/OPG signaling, depress toll-like receptor 4/myeloid differentiation factor 88 (TLR4/MyD88)-mediated pro-inflammatory cytokine activation, and successfully suppress the pathogenesis of PD. PD was induced in adult rats by placing the ligature at molar subgingival regions. Fourteen days before PD induction, 10, 50, or 100 mg/kg of melatonin was intraperitoneally injected for consecutive 28 days. Biochemical and enzyme-linked immunosorbent assay were used to detect TLR4/MyD88 activity, RANKL, OPG, interleukin 1ß, interleukin 6, and tumor necrosis factor-α levels, respectively. The extent of bone loss, bone mineral intensity, and calcium intensity was further evaluated by scanning electron microscopy, micro-computed tomography, and energy-dispersive X-ray spectroscopy. Results indicated that high RANKL/OPG ratio, TLR4/MyD88 activity, and pro-inflammatory cytokine levels were detected following PD. Impaired biochemical findings paralleled well with severe bone loss and reduced calcium intensity. However, in rats pretreated with melatonin, all above parameters were successfully returned to nearly normal levels with maximal change observed in rats receiving 100 mg/kg. As prophylactic treatment with melatonin effectively normalizes RANKL/OPG signaling by depressing TLR4/MyD88-mediated pro-inflammatory cytokine production, dietary supplement with melatonin may serve as an advanced strategy to strengthen oral health to counteract PD-induced destructive damage.


Assuntos
Antioxidantes/farmacologia , Melatonina/farmacologia , Periodontite/patologia , Transdução de Sinais/efeitos dos fármacos , Animais , Masculino , Fator 88 de Diferenciação Mieloide/efeitos dos fármacos , Fator 88 de Diferenciação Mieloide/metabolismo , Osteoprotegerina/efeitos dos fármacos , Osteoprotegerina/metabolismo , Periodontite/prevenção & controle , Profilaxia Pré-Exposição/métodos , Ligante RANK/efeitos dos fármacos , Ligante RANK/metabolismo , Ratos , Ratos Wistar , Receptor 4 Toll-Like
7.
Molecules ; 23(2)2018 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-29473874

RESUMO

G-quadruplexes are four-stranded nucleic acid secondary structures that are formed in guanine-rich sequences. G-quadruplexes are widely distributed in functional regions of the human genome and transcriptome, such as human telomeres, oncogene promoter regions, replication initiation sites, and untranslated regions. Many G-quadruplex-forming sequences are found to be associated with cancer, and thus, these non-canonical nucleic acid structures are considered to be attractive molecular targets for cancer therapeutics with novel mechanisms of action. In this mini review, we summarize recent advances made by our lab in the study of G-quadruplex-targeted natural alkaloids and their derivatives toward the development of potential anticancer agents.


Assuntos
Alcaloides/química , Alcaloides/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Produtos Biológicos/química , Produtos Biológicos/farmacologia , Quadruplex G , Compostos Heterocíclicos/química , Compostos Heterocíclicos/farmacologia , Desenho de Fármacos , Humanos , Ligantes , Oncogenes , Regiões Promotoras Genéticas , RNA/química , RNA/genética , Relação Estrutura-Atividade
8.
ScientificWorldJournal ; 2015: 492683, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25884030

RESUMO

One of the causes of dental pulpitis is lipopolysaccharide- (LPS-) induced inflammatory response. Following pulp tissue inflammation, odontoblasts, dental pulp cells (DPCs), and dental pulp stem cells (DPSCs) will activate and repair damaged tissue to maintain homeostasis. However, when LPS infection is too serious, dental repair is impossible and disease may progress to irreversible pulpitis. Therefore, the aim of this study was to examine whether static magnetic field (SMF) can attenuate inflammatory response of dental pulp cells challenged with LPS. In methodology, dental pulp cells were isolated from extracted teeth. The population of DPSCs in the cultured DPCs was identified by phenotypes and multilineage differentiation. The effects of 0.4 T SMF on DPCs were observed through MTT assay and fluorescent anisotropy assay. Our results showed that the SMF exposure had no effect on surface markers or multilineage differentiation capability. However, SMF exposure increases cell viability by 15%. In addition, SMF increased cell membrane rigidity which is directly related to higher fluorescent anisotropy. In the LPS-challenged condition, DPCs treated with SMF demonstrated a higher tolerance to LPS-induced inflammatory response when compared to untreated controls. According to these results, we suggest that 0.4 T SMF attenuates LPS-induced inflammatory response to DPCs by changing cell membrane stability.


Assuntos
Membrana Celular/metabolismo , Polpa Dentária/patologia , Inflamação/patologia , Campos Magnéticos , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Polpa Dentária/efeitos dos fármacos , Citometria de Fluxo , Polarização de Fluorescência , Humanos , Lipopolissacarídeos , Coloração e Rotulagem
9.
ScientificWorldJournal ; 2015: 289647, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25884025

RESUMO

Proinflammatory cytokines are key inflammatory mediators in periodontitis. This study aimed to investigate the relationship between proinflammatory cytokines in saliva and periodontal status. To investigate the usefulness of cytokines in the therapeutic approach for periodontal disease, the relationship between stimulated cytokine changes and the periodontitis treatment outcome was investigated in this study. Saliva was obtained from 22 patients diagnosed by dentists as having chronic periodontitis. The proinflammatory cytokine (interleukin-1α (IL-1α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6), interleukin-8 (IL-8), tumor necrosis factor α (TNF-α), and tumor necrosis factor ß (TNF-ß)) levels were determined using a commercially available kit. The IL-1ß and IL-6 levels increased, whereas the TNF-ß levels decreased with the severity of periodontitis (4 mm pocket percentage). Poststimulation IL-1α, IL-6, and IL-8 levels were higher in patients who had an improved treatment outcome. The differences of IL-6 levels (cut point: 0.05 µg/g) yielded a sensitivity and specificity of 90.0% and 81.82%, respectively, for predicting the periodontitis treatment outcome. Among the proinflammatory cytokines, stimulated IL-6 was an excellent marker for predicting the periodontitis treatment outcome.


Assuntos
Citocinas/metabolismo , Mediadores da Inflamação/metabolismo , Periodontite/metabolismo , Periodontite/terapia , Adulto , Idoso , Área Sob a Curva , Demografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Curva ROC , Fatores de Risco , Saliva/metabolismo , Resultado do Tratamento
10.
Electromagn Biol Med ; 34(4): 302-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-24856869

RESUMO

Successful and efficient cryopreservation of living cells and organs is a key clinical application of regenerative medicine. Recently, magnetic cryopreservation has been reported for intact tooth banking and cryopreservation of dental tissue. The aim of this study was to assess the cryoprotective effects of static magnetic fields (SMFs) on human dental pulp stem cells (DPSCs) during cryopreservation. Human DPSCs isolated from extracted teeth were frozen with a 0.4-T or 0.8-T SMF and then stored at -196 °C for 24 h. During freezing, the cells were suspended in freezing media containing with 0, 3 or 10% DMSO. After thawing, the changes in survival rate of the DPSCs were determined by flow cytometry. To understand the possible cryoprotective mechanisms of the SMF, the membrane fluidity of SMF-exposed DPSCs was tested. The results showed that when the freezing medium was DMSO-free, the survival rates of the thawed DPSCs increased 2- or 2.5-fold when the cells were exposed to 0.4-T or 0.8-T SMFs, respectively (p < 0.01). In addition, after exposure to the 0.4-T SMF, the fluorescence anisotropy of the DPSCs increased significantly (p < 0.01) in the hydrophilic region. These results show that SMF exposure improved DMSO-free cryopreservation. This phenomenon may be due to the improvement of membrane stability for resisting damage caused by ice crystals during the freezing procedure.


Assuntos
Criopreservação/métodos , Polpa Dentária/citologia , Campos Magnéticos , Células-Tronco/citologia , Adolescente , Adulto , Anisotropia , Diferenciação Celular , Linhagem da Célula , Membrana Celular/fisiologia , Sobrevivência Celular , Polpa Dentária/efeitos da radiação , Dimetil Sulfóxido/química , Citometria de Fluxo , Humanos , Microscopia de Fluorescência , Células-Tronco/efeitos da radiação , Adulto Jovem
11.
Fungal Genet Biol ; 70: 68-76, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25038494

RESUMO

Candida albicans is considered to be an obligate diploid fungus. Here, we describe an approach to isolate aneuploids or haploids induced by the short-term (12-16 h) exposure of diploid reference strains SC5314 and CAI4 to the most commonly used antifungal drug, fluconazole, followed by repeated single-cell separation among small morphologically distinct colonies in the inhibition zone. The isolated strains had altered cell morphology and LOH events in the MTL and other marker alleles of the analyzed loci at 8 chromosomes of C. albicans with decreased DNA content. The present study employed next-generation sequencing (NGS) combined flow cytometry analysis of the DNA content to analyze the haploid, autodiploid, and aneuploid strains that arose from the fluconazole treatment instead of using the conventional single nucleotide polymorphism/comparative genome hybridization (SNP/CGH) method. A multiple-alignment tool was also developed based on sequenced data from NGS to establish haplotype mapping for each chromosome of the selected strains. These findings revealed that C. albicans experiences 'concerted chromosome loss' to form strains with homozygous alleles and that it even has a haploid status after short-term exposure to fluconazole. Additionally, we developed a new platform to analyze chromosome copy number using NGS.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Cromossomos Fúngicos , Fluconazol/farmacologia , Aneuploidia , Candida albicans/citologia , Candida albicans/genética , Hibridização Genômica Comparativa , Haploidia , Perda de Heterozigosidade , Polimorfismo de Nucleotídeo Único
12.
ScientificWorldJournal ; 2014: 814671, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25538964

RESUMO

AIM: Our goal was to investigate associations among scaling-stimulated changes in salivary antioxidants, oral-health-related behaviors and attitudes, and periodontal treatment outcomes. MATERIALS AND METHODS: Thirty periodontitis patients with at least 6 pockets with pocket depths of >5 mm and more than 16 functional teeth were enrolled in the study. Patients were divided into three groups: an abandoned group (AB group), a nonprogress outcome group (NP group), and an effective treatment group (ET group). Nonstimulated saliva was collected before and after scaling were received to determine superoxide dismutase (SOD) and the total antioxidant capacity (TAOC). RESULTS: Salivary SOD following scaling significantly increased from 83.09 to 194.30 U/g protein in patients who had irregular dental visit patterns (<1 visit per year). After scaling, the TAOC was significantly higher in patients who had regular dental visits than in patients who had irregular dental visits (3.52 versus 0.70 mmole/g protein, P < 0.01). The scaling-stimulated increase in SOD was related to a higher severity of periodontitis in the NP group, while the scaling-stimulated increase in the TAOC was inversely related to the severity of periodontitis in the AB group. CONCLUSIONS: These results demonstrate the importance of scaling-stimulated salivary antioxidants as prognostic biomarkers of periodontal treatment.


Assuntos
Antioxidantes/metabolismo , Comportamentos Relacionados com a Saúde , Saúde Bucal , Periodontite/metabolismo , Saliva/metabolismo , Superóxido Dismutase/metabolismo , Adulto , Biomarcadores/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Periodontite/terapia
13.
Sci Rep ; 13(1): 21219, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38040846

RESUMO

It is significant to predict welding quality during gas metal arc welding process. The welding defect detection algorithm has been developed based on convolutional neural network (CNN). The sensing system and image processing algorithm for molten pools has been developed. It overcomes the interference caused by the arc light to obtain clear images of the molten pool's boundaries. The molten pools images are used to build up training set and test set for training and testing the CNN model. The model is designed to extract the visual features of molten pool images to predict the penetration state, the welding crater, and slags. Through optimizing the network parameters such as kernel-size, batch-size and learning rate, the prediction accuracy is higher than 95%. Moreover, the model enhances additional focus on the welding crater based on the welder experience. The mechanisms between molten pool characteristics and welding defects were analyzed based on the welder experience and the visual features of the model. It is found that the model judges the occurrence of burn-through with the black hole in the middle zone of the molten pool. When the surface pores are generated, the model exhibits a strong response to circular voids in the semi-solid region at the trailing end of the molten pool. The size and shape of fusion holes exhibit a strong correlation with the molten state. When the shape of the crater does not appear concave, it often signifies excessive penetration. It contributes to enhancing the algorithm's robustness during various welding scenarios.

14.
Artigo em Inglês | MEDLINE | ID: mdl-36084166

RESUMO

A new efficient magnetic solid-phase extractant based on a surface-modified magnetic mesoporous silica microsphere referred as MMSM-PEI was synthesised and used for the enrichment and isolation of copper ions (Cu2+) in preserved eggs. The physicochemical properties and morphology of MMSM-PEI were characterized by X-ray diffraction (XRD) spectroscopy, Fourier transform infrared spectroscopy (FT-IR), vibration sample magnetometry (VSM), scanning electron microscopy (SEM) and thermos-gravimetric analyses (TGA). The concentrations of trace Cu2+ in the preserved egg were determined by flame atomic absorption spectroscopy (FAAS). The effects of important parameters were examined. The most suitable pH values and temperature for adsorbing Cu2+ were 6.5 and 25 °C, respectively. According to the determination of Cu2+ in egg white, egg yolk and the outer coating mixture (TOCM) of preserved eggs, the spiked recovery and RSD were 94.1-103.8% and 0.96-4.35%, respectively. The limit of detection (LOD) and the limit of quantitation (LOQ) were 0.14 mg/kg and 0.46 mg/kg, respectively. The developed method improved the sensitivity and accuracy of FAAS for the determination of Cu2+ and it could be applied to the determination of trace Cu2+ in real samples.


Assuntos
Polietilenoimina , Dióxido de Silício , Espectrofotometria Atômica/métodos , Dióxido de Silício/química , Polietilenoimina/análise , Espectroscopia de Infravermelho com Transformada de Fourier , Extração em Fase Sólida/métodos , Microesferas , Temperatura , Cobre/análise , Digestão , Fenômenos Magnéticos , Adsorção
15.
Cir Cir ; 90(4): 439-446, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35944394

RESUMO

INTRODUCTION: This study investigates the relationship between cellularity and capsular characteristics of pleomorphic adenoma and its influence on operative strategies. MATERIAL AND METHODS: The capsular characteristics and clinical data of patients with pleomorphic adenomas were reviewed according to Seifert's definition: (1) classic type with balanced amount of cells and stroma, (2) myxoid type with abundant ground substance, interspersed spindle cells, and (3) cellular type with predominance of ductal trabecular structures and little stroma. The immunoreactivity of cellular proliferation (Ki-67) was semi-quantitatively measured using immunohistochemistry. Variables were analyzed using Fisher's test and one-way ANOVA, with (p < 0.05) considered statistically significant. RESULTS: The duration of presence was associated with cellularity (p = 0.01). In terms of capsular characteristics, satellite nodules and positive resection margins were not related to cellularity, except for incomplete capsules (p = 0.03). There was no difference in the staining scores of Ki-67 (p = 0.12). CONCLUSION: Lower cellularity reflects higher probability of an incomplete capsule, requiring more consideration for operative strategies to prevent recurrence.


INTRODUCCIÓN: Este estudio investiga la relación entre la celularidad y las características capsulares del adenoma pleomórfico y su influencia en las estrategias operativas. MATERIAL Y MÉTODOS: Se revisaron las características capsulares y los datos clínicos de los pacientes con adenomas pleomórficos según la definición de Seifert: 1) tipo clásico con cantidad equilibrada de células y estroma, 2) tipo mixoide con abundante sustancia fundamental, células fusiformes intercaladas y 3) tipo celular con predominio de estructuras trabeculares ductales y poco estroma. La inmunorreactividad de la proliferación celular (Ki-67) se midió semicuantitativamente usando inmunohistoquímica. Las variables se analizaron mediante la prueba de Fisher y ANOVA de una vía, considerándose significativo un valor de p inferior a 0.05. RESULTADOS: La duración de la presencia se asoció con la celularidad (p = 0.01). En cuanto a las características capsulares, los nódulos satélites y los márgenes de resección positivos no se relacionaron con la celularidad, a excepción de las cápsulas incompletas (p = 0.03). No hubo diferencia en las puntuaciones de tinción de Ki-67 (p = 0.12). CONCLUSIONES: La celularidad más baja refleja una mayor probabilidad de una cápsula incompleta, lo que requiere una mayor consideración de las estrategias quirúrgicas para prevenir la recurrencia.


Assuntos
Adenoma Pleomorfo , Neoplasias Parotídeas , Adenoma Pleomorfo/cirurgia , Humanos , Antígeno Ki-67 , Margens de Excisão , Neoplasias Parotídeas/cirurgia
16.
BMC Cancer ; 10: 95, 2010 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-20226009

RESUMO

BACKGROUND: Invasiveness and metastasis are the most common characteristics of non small cell lung cancer (NSCLC) and causes of tumour-related morbidity and mortality. Mitogen-activated protein kinases (MAPKs) signalling pathways have been shown to play critical roles in tumorigenesis. However, the precise pathological role(s) of mitogen-activated protein kinase phosphatase-1 (MKP-1) in different cancers has been controversial such that the up-regulation of MKP-1 in different cancers does not always correlate to a better prognosis. In this study, we showed that the induction of MKP-1 lead to a significant retardation of proliferation and metastasis in NSCLC cells. We also established that rosiglitazone (a PPARgamma agonist) elevated MKP-1 expression level in NSCLC cells and inhibited tumour metastasis. METHODS: Both wildtype and dominant negative forms of MKP-1 were constitutively expressed in NSCLC cell line H441GL. The migration and invasion abilities of these cells were examined in vitro. MKP-1 modulating agents such as rosiglitazone and triptolide were used to demonstrate MKP-1's role in tumorigenesis. Bioluminescent imaging was utilized to study tumorigenesis of MKP-1 over-expressing H441GL cells and anti-metastatic effect of rosiglitazone. RESULTS: Over-expression of MKP-1 reduced NSCLC cell proliferation rate as well as cell invasive and migratory abilities, evident by the reduced expression levels of MMP-2 and CXCR4. Mice inoculated with MKP-1 over-expressing H441 cells did not develop NSCLC while their control wildtype H441 inoculated littermates developed NSCLC and bone metastasis. Pharmacologically, rosiglitazone, a peroxisome proliferator activated receptor-gamma (PPARgamma) agonist appeared to induce MKP-1 expression while reduce MMP-2 and CXCR4 expression. H441GL-inoculated mice receiving daily oral rosiglitazone treatment demonstrated a significant inhibition of bone metastasis when compared to mice receiving sham treatment. We found that rosiglitazone treatment impeded the ability of cell migration and invasion in vitro. Cells pre-treated with triptolide (a MKP-1 inhibitor), reversed rosiglitazone-mediated cell invasion and migration. CONCLUSION: The induction of MKP-1 could significantly suppress the proliferative and metastatic abilities of NSCLC both in vitro and in vivo. Therefore, MKP-1 could be considered as a potential therapeutic target in NSCLC therapy and PPARgamma agonists could be explored for combined chemotherapy.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/enzimologia , Fosfatase 1 de Especificidade Dupla/metabolismo , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/enzimologia , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Humanos , Luminescência , Sistema de Sinalização das MAP Quinases , Metaloproteinase 2 da Matriz/biossíntese , Camundongos , Camundongos SCID , Imagem Molecular/métodos , Invasividade Neoplásica , Metástase Neoplásica , Receptores CXCR4/biossíntese
17.
Transfusion ; 50(8): 1702-11, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20412527

RESUMO

BACKGROUND: Human platelet concentrates (PCs) may be a source material to produce purified growth factors (GFs) for clinical use or cell therapy. However, no fractionation process of therapeutic-grade GF from PCs has ever been developed. STUDY DESIGN AND METHODS: PCs were virally inactivated by solvent/detergent (S/D) treatment, subjected to oil extraction to remove part of the S/D agents, and fractionated on a SP-Sepharose (SP) chromatographic column equilibrated in a phosphate-buffered saline (PBS) buffer, pH 7.5. The breakthrough was recovered, and the column was washed with the PBS buffer and then eluted by a 0.7 mol/L NaCl-PBS buffer pH 7.5 (SP-eluate). The SP-breakthrough and SP-eluate were characterized for their content in GF, proteins, lipids, and S/D agents. The MTS value of three cell lines cultivated in a medium containing 10% fetal bovine serum supplemented with 1% to 3% of SP-eluate or recombinant human (rHu) platelet-derived growth factor (PDGF)-BB was compared. RESULTS: The SP-eluate contained a mean of 47, 17, and 6 ng/mL PDGF-AB, -BB, and -AA, respectively, and 0.26 ng/mL vascular endothelial growth factor (VEGF). It was largely depleted of transforming growth factor-ß1 (2.33 ng/mL), epidermal growth factor (0.09 ng/mL), insulin-like growth factor (3.40 ng/mL), albumin, immunoglobulin (Ig)G, IgM, IgA, and fibrinogen, which were mostly in the breakthrough. tri-n-butyl phosphate and Triton X-45 were less than 2 ppm. Cell growth-promoting activity of the SP-eluate was at least as good as that of rHu-PDGF-BB. CONCLUSION: Human PC can be fractionated into a purified, virally inactivated PDGF and VEGF concentrate, opening perspectives for the development of a new range of blood products for clinical use and cell therapy procedures.


Assuntos
Plaquetas/química , Fator de Crescimento Derivado de Plaquetas/isolamento & purificação , Fator A de Crescimento do Endotélio Vascular/isolamento & purificação , Células Cultivadas , Cromatografia , Humanos , Contagem de Plaquetas
18.
Biotechnol Appl Biochem ; 56(4): 151-60, 2010 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-20608898

RESUMO

There is emerging interest in the use of standardized virally inactivated human platelet lysate preparations rich in GFs (growth factors) for cell cultures, cell therapy and clinical applications. In the present paper, we report a simple process to prepare a virally inactivated platelet lysate preparation rich in TGF-beta1 (transforming growth factor-beta1), EGF (epidermal growth factor) and IGF (insulin-like growth factor) and depleted of PDGF (platelet-derived growth factor) and VEGF (vascular endothelial growth factor). Apheresis platelet concentrates were treated by the S/D (solvent/detergent) viral inactivation procedure, then subjected to an oil extraction followed by adsorption with activated charcoal and finally sterile-filtered. The resulting preparation contained a mean of 368.4, 2.4 and 54.7 ng/ml of TGF-beta1, EGF and IGF respectively. PDGF-AB and VEGF were essentially completely removed by the charcoal treatment. The mean albumin, IgG, IgM and IgA and fibrinogen contents were approx. 40.0, 8.5, 0.87, 1.66 and 2.65 mg/ml respectively, cholesterol and triglycerides were at 15 and 20.7 mg/ml respectively and TnBP (tri-n-butyl phosphate) and Triton X-45 were at 8.7 and 8.8 p.p.m. respectively. Supplementing MEM (minimum essential medium) with 1-10% of this S/D-treated platelet lysate promoted the proliferation of MG63 and SIRC cell lines as well as, or better than, 10% (v/v) FBS (fetal bovine serum), as based on the MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay. The process used to prepare such S/D-treated platelet lysates is easily scalable for industrial production. Our results open up the possibility to evaluate the potential of this new preparation for stem cell expansion and/or bone tissue engineering and regeneration.


Assuntos
Plaquetas/química , Técnicas de Cultura de Células/métodos , Fator de Crescimento Epidérmico/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fatores de Crescimento do Endotélio Vascular/metabolismo , Bioensaio , Plaquetas/citologia , Plaquetas/metabolismo , Linhagem Celular , Proliferação de Células , Células Cultivadas , Detergentes/química , Fator de Crescimento Epidérmico/isolamento & purificação , Humanos , Fator de Crescimento Insulin-Like I/isolamento & purificação , Óleos/química , Fator de Crescimento Derivado de Plaquetas/isolamento & purificação , Solventes/química , Fator de Crescimento Transformador beta/isolamento & purificação , Fatores de Crescimento do Endotélio Vascular/isolamento & purificação , Inativação de Vírus
19.
Bioelectromagnetics ; 31(4): 255-61, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-19953573

RESUMO

While the effects of static magnetic fields (SMFs) on osteoblastic differentiation are well demonstrated, the mechanotransduction pathways of SMFs are still unclear. The aim of this study was to explore the role of calmodulin in the biophysical effects of SMFs on osteoblastic cells. MG63 cells were exposed to a 0.4 T SMF. The expression of phosphodiesterase RNA in the cytoplasm was tested using real-time polymerase chain reaction. The differentiation of the cells was assessed by detecting changes in alkaline phosphatase activity. The role of calmodulin antagonist W-7 was used to evaluate alterations in osteoblastic proliferation and differentiation after the SMF simulations. Our results showed that SMF exposure increased alkaline phosphatase activity and phosphodiesterase 1C gene expression in MG63 cells. Addition of W-7 significantly inhibited the SMF-induced cellular response. We suggest that one possible mechanism by which SMFs affects osteoblastic maturation is through a calmodulin-dependent mechanotransduction pathway.


Assuntos
Calmodulina/fisiologia , Campos Eletromagnéticos , Mecanotransdução Celular , Osteoblastos/efeitos da radiação , Calmodulina/antagonistas & inibidores , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Células Cultivadas , Nucleotídeo Cíclico Fosfodiesterase do Tipo 1/biossíntese , Humanos , Osteoblastos/fisiologia , Sulfonamidas/farmacologia
20.
Chem Commun (Camb) ; 56(3): 423-426, 2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31822876

RESUMO

Iridium-catalyzed boron-hydrogen bond insertion reactions of trimethylamine-borane and sulfoxonium ylides have been demonstrated, furnishing α-boryl ketones in moderate to excellent yields in most cases (51 examples; up to 84%). This practical and scalable insertion reaction showed broad substrate scope, high functional-group compatibility and could be applied in late-stage modification of structurally complex drug compounds. Further synthetic applications were also demonstrated.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA