Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 153
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 10(1): 978, 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969646

RESUMO

Societal lifestyle changes, especially increased consumption of a high-fat diet lacking dietary fibers, lead to gut microbiota dysbiosis and enhance the incidence of adiposity and chronic inflammatory disease. We aimed to investigate the metabolic effects of inulin with different degrees of polymerization on high-fat diet-fed C57BL/6 J mice and to evaluate whether different health outcomes are related to regulation of the gut microbiota. Short-chain and long-chain inulins exert beneficial effects through alleviating endotoxemia and inflammation. Antiinflammation was associated with a proportional increase in short-chain fatty acid-producing bacteria and an increase in the concentration of short-chain fatty acids. Inulin might decrease endotoxemia by increasing the proportion of Bifidobacterium and Lactobacillus, and their inhibition of endotoxin secretion may also contribute to antiinflammation. Interestingly, the beneficial health effects of long-chain inulin were more pronounced than those of short-chain inulin. Long-chain inulin was more dependent than short-chain inulin on species capable of processing complex polysaccharides, such as Bacteroides. A good understanding of inulin-gut microbiota-host interactions helps to provide a dietary strategy that could target and prevent high-fat diet-induced endotoxemia and inflammation through a prebiotic effect.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31720687

RESUMO

CONTEXT: Serum uric acid has been linked to risk of type 2 diabetes (T2DM) but debate persists as to whether it plays a causal role. Indeed, it is unclear if changes in uric acid relate to the pathophysiologic determinants of T2DM (insulin resistance, beta-cell dysfunction), as would be expected if causal. OBJECTIVE: To evaluate the impact of changes in uric acid over 2-years on changes in insulin sensitivity, beta-cell function and glycemia in women with and without recent gestational diabetes (GDM), a model of the early natural history of T2DM. DESIGN/SETTING/PARTICIPANTS: At both 1- and 3-years postpartum, 299 women (96 with recent GDM) underwent uric acid measurement and oral glucose tolerance tests that enabled assessment of insulin sensitivity/resistance (Matsuda index, Homeostasis Model Assessment (HOMA-IR)), beta-cell function (Insulin Secretion-Sensitivity Index-2 (ISSI-2), insulinogenic index/HOMA-IR (IGI/HOMA-IR)), and glucose tolerance. RESULTS: Women with recent GDM had higher serum uric acid than their peers at both 1-year (281±69 vs 262±58 µmol/l, p=0.01) and 3-years postpartum (271±59 vs 256±55 µmol/l, p=0.03), coupled with lower insulin sensitivity, poorer beta-cell function, and greater glycemia (all p<0.05). However, on fully-adjusted analyses, neither uric acid at 1-year nor its change from 1-to-3-years was independently associated with any of the following metabolic outcomes at 3-years postpartum: Matsuda index, HOMA-IR, ISSI-2, IGI/HOMA-IR, fasting glucose, 2-hour glucose, or glucose intolerance. CONCLUSION: Serum uric acid does not track with changes over time in insulin sensitivity, beta-cell function or glycemia in women with recent GDM, providing evidence against causality in its association with diabetes.

3.
J Am Heart Assoc ; 8(21): e014231, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31657272

RESUMO

Background The 1-hour glucose challenge test (GCT) is routinely performed in pregnancy to screen for gestational diabetes mellitus. Remarkably, it has recently emerged that the GCT can also predict a woman's future risk of cardiovascular disease, although the mechanistic basis of this relationship is unclear. In this context we hypothesized that a higher GCT may identify women with an otherwise unrecognized adverse cardiovascular phenotype. Thus, we sought to evaluate the relationship between the antepartum GCT and subsequent postpartum cardiovascular risk factor profile. Methods and Results In this study 503 women completed a screening GCT in late second trimester and then underwent cardiometabolic characterization at 3 months postpartum, whereupon traditional (blood pressure, glucose, lipids) and nontraditional (apolipoprotein B, C-reactive protein, adiponectin) cardiovascular risk factors were compared across GCT tertiles. At 3 months postpartum, each of the following risk factors progressively worsened from the lowest to middle to highest GCT tertile: fasting glucose (P=0.0002), 2-hour glucose (P<0.0001), total cholesterol:high-density lipoprotein cholesterol (P=0.0004), high-density lipoprotein cholesterol (P=0.004), triglycerides (P=0.001), apolipoprotein B (P=0.001), and adiponectin (P=0.02). On multiple linear regression analyses, the GCT emerged as a significant independent predictor of higher fasting glucose (P=0.0006), 2-hour glucose (P<0.0001), total cholesterol: high-density lipoprotein cholesterol (P=0.0004), triglycerides (P=0.001), low-density lipoprotein cholesterol (P=0.01), and apolipoprotein B (P=0.004) and of lower high-density lipoprotein cholesterol (P=0.02) and adiponectin (P=0.0099). Moreover, these independent associations persisted after excluding women who had gestational diabetes mellitus. Conclusions The antepartum GCT can identify women with an adverse underlying cardiovascular risk factor phenotype.

4.
J Biol Chem ; 294(47): 17889-17902, 2019 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-31628192

RESUMO

The neuropilin and tolloid-like (Neto) proteins Neto1 and Neto2 are auxiliary subunits of kainate-type glutamate receptors (KARs) that regulate KAR trafficking and gating. However, how Netos bind and regulate the biophysical functions of KARs remains unclear. Here, we found that the N-terminal domain (NTD) of glutamate receptor ionotropic kainate 2 (GluK2) binds the first complement C1r/C1s-Uegf-BMP (CUB) domain of Neto proteins (i.e. NTD-CUB1 interaction) and that the core of GluK2 (GluK2ΔNTD) binds Netos through domains other than CUB1s (core-Neto interaction). Using electrophysiological analysis in HEK293T cells, we examined the effects of these interactions on GluK2 gating, including deactivation, desensitization, and recovery from desensitization. We found that NTD deletion does not affect GluK2 fast gating kinetics, the desensitization, and the deactivation. We also observed that Neto1 and Neto2 differentially regulate GluK2 fast gating kinetics, which largely rely on the NTD-CUB1 interactions. NTD removal facilitated GluK2 recovery from desensitization, indicating that the NTD stabilizes the GluK2 desensitization state. Co-expression with Neto1 or Neto2 also accelerated GluK2 recovery from desensitization, which fully relied on the NTD-CUB1 interactions. Moreover, we demonstrate that the NTD-CUB1 interaction involves electric attraction between positively charged residues in the GluK2_NTD and negatively charged ones in the CUB1 domains. Neutralization of these charges eliminated the regulatory effects of the NTD-CUB1 interaction on GluK2 gating. We conclude that KARs bind Netos through at least two sites and that the NTD-CUB1 interaction critically regulates Neto-mediated GluK2 gating.

5.
Poult Sci ; 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31579901

RESUMO

An improved fast region-based convolutional neural network (RCNN) algorithm is proposed to improve the accuracy and efficiency of recognizing broilers in a stunned state. The algorithm recognizes 3 stunned state conditions: insufficiently stunned, moderately stunned, and excessively stunned. Image samples of stunned broilers were collected from a slaughter line using an image acquisition platform. According to the format of PASCAL VOC (pattern analysis, statistical modeling, and computational learning visual object classes) dataset, a dataset for each broiler stunned state condition was obtained using an annotation tool to mark the chicken head and wing area in the original image. A rotation and flip data augmentation method was used to enhance the effectiveness of the datasets. Based on the principle of a residual network, a multi-layer residual module (MRM) was constructed to facilitate more detailed feature extraction. A model was then developed (entitled here Faster-RCNN+MRMnet) and used to detect broiler stunned state conditions. When applied to a reinforcing dataset containing 27,828 images of chickens in a stunned state, the identification accuracy of the model was 98.06%. This was significantly higher than both the established back propagation neural network model (90.11%) and another Faster-RCNN model (96.86%). The proposed algorithm can complete the inspection of the stunned state of more than 40,000 broilers per hour. The approach can be used for online inspection applications to increase efficiency, reduce labor and cost, and yield significant benefits for poultry processing plants.

6.
J Cancer Res Clin Oncol ; 145(11): 2863-2870, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31501983

RESUMO

PURPOSE: To determine the association between lymphovascular invasion (LVI) and upper tract urothelial carcinoma (UTUC) among patients who underwent radical nephroureterectomy (RNU). MATERIALS AND METHODS: From 2003 and 2018, retrospective data of 453 patients treated for UTUC with open, laparoscopic, or robotic RNU were collected. Pathological specimens were assessed for LVI through hematoxylin and eosin staining. According to presence of LVI, patients were stratified into two groups and compared for perioperative characteristics. Kaplan-Meier analysis was used to assess progression-free (PFS), cancer-specific (CSS), and overall survival (OS). Uni- and multivariate Cox regression models were used to find significance of LVI to survival. RESULTS: LVI was present in 132 (29.1%) of patients and was associated with higher age and lower preoperative GFR. Pathological outcomes included significantly higher tumor grade, higher rates of lymph node invasion and more positive surgical margins. During median 23.2 months follow-up (mean 37.1 months), 59.2% (n = 268) of total patients had tumor recurrence, with highest incidences in lymph nodes (51.5%). 5-year PFS, CSS, and OS were estimated at 35.4%, 94.6%, and 91.1% in LVI-negative patients and 17.2%, 75.1%, and 70.8% in LVI-positive patients, respectively (all p < 0.001). Multivariate analysis showed LVI to be an independent predictor of PFS (HR = 1.480; p = 0.018). CONCLUSION: LVI is an independent predictor of adverse PFS and is associated with poor CSS and OS in patients undergoing RNU for UTUC. These results may guide clinicians in selecting patients for adjuvant chemotherapy. Future prospective trials are necessary to further validate our results.


Assuntos
Linfonodos/patologia , Vasos Linfáticos/patologia , Recidiva Local de Neoplasia/mortalidade , Nefroureterectomia/mortalidade , Neoplasias Urológicas/mortalidade , Idoso , Feminino , Seguimentos , Humanos , Metástase Linfática , Masculino , Invasividade Neoplásica , Recidiva Local de Neoplasia/patologia , Recidiva Local de Neoplasia/cirurgia , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Neoplasias Urológicas/patologia , Neoplasias Urológicas/cirurgia
7.
Arterioscler Thromb Vasc Biol ; 39(10): 2192-2197, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31412738

RESUMO

OBJECTIVE: apoA1 (apolipoprotein A-1) is the main lipoprotein associated with HDL (high-density lipoprotein) cholesterol. It was recently reported that intravenous infusion of apoA1 could lower insulin resistance in pregnant rats, leading to the suggestion that apoA1 could provide a target for reducing pregnancy-induced insulin resistance and the risk of gestational diabetes mellitus (GDM) in humans. However, the effects of apoA1 on insulin resistance and risk of GDM in human pregnancy are not known. Thus, we sought to systematically evaluate the relationships of apoA1 with glucose homeostasis and metabolic function in pregnant women. Approach and Results: In this study, 870 pregnant women were recruited in late second trimester and underwent metabolic characterization, including an oral glucose tolerance test on which 214 were diagnosed with GDM. Metabolic characterization included assessment of glucose tolerance, insulin sensitivity/resistance (Matsuda index, homeostasis model assessment of insulin resistance), pancreatic ß-cell function, lipids (LDL [low-density lipoprotein] cholesterol, HDL cholesterol, triglycerides, apoB [apolipoprotein B], and apoA1), CRP (C-reactive protein), and adiponectin. Serum apoA1 was strongly correlated with HDL (r=0.79, P<0.0001) and weakly so with adiponectin (r=0.12, P=0.0004) but showed no association with measures of insulin sensitivity/resistance, ß-cell function, glycemia, or CRP. There were no significant differences across apoA1 tertiles in mean adjusted Matsuda index (P=0.24), homeostasis model assessment of insulin resistance (P=0.08), or area under the glucose curve on the oral glucose tolerance test (P=0.96). Moreover, there were no differences in risk of GDM across tertiles of apoA1, both before (P=0.67) and after covariate adjustment (P=0.78). CONCLUSIONS: Serum apoA1 is not associated with insulin resistance or the risk of GDM in human pregnancy.

8.
Can J Diabetes ; 43(8): 567-572, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31439472

RESUMO

OBJECTIVES: Serum markers of iron storage have been linked to type 2 diabetes; however, the mechanism underlying this association is unclear. In pregnancy, increased serum ferritin has been reported in women with gestational diabetes (GDM), a patient population at high risk of future type 2 diabetes. However, in the years after pregnancy, it is not known if ferritin relates to their diabetes risk or the pathophysiologic determinants thereof (insulin sensitivity and beta-cell function). Therefore, we sought to characterize the relationship between ferritin and glucose homeostasis in the early postpartum years in women with and without recent GDM. METHODS: At both 1 and 3 years postpartum, 340 women (105 with recent GDM) underwent serum ferritin measurement and an oral glucose tolerance test that enabled assessment of insulin sensitivity and/or resistance (Matsuda index and Homeostasis Model Assessment [HOMA-IR]), beta-cell function (Insulin Secretion-Sensitivity Index-2 and insulinogenic index/HOMA-IR) and glucose tolerance. RESULTS: Serum ferritin did not differ between women who had GDM and their peers at either 1 or 3 years postpartum. Baseline-adjusted change in ferritin between 1 and 3 years correlated with the concomitant change in C-reactive protein (r=0.21, p=0.0002) but was not associated with measures of insulin sensitivity and/or resistance, beta-cell function or glycemia. On adjusted analyses, neither baseline ferritin nor its change from 1 to 3 years was independently associated with any of the following metabolic outcomes at 3-years postpartum: Matsuda index, HOMA-IR, Insulin Secretion-Sensitivity Index-2, insulinogenic index/HOMA-IR, fasting glucose, 2-h glucose or glucose intolerance. CONCLUSIONS: Serum ferritin is not associated with glucose homeostasis in the early years after a GDM pregnancy.

9.
Cell Rep ; 28(4): 1050-1062.e6, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340143

RESUMO

Reduced mRNA translation delays aging, but the underlying mechanisms remain underexplored. Mutations in both DAF-2 (IGF-1 receptor) and RSKS-1 (ribosomal S6 kinase/S6K) cause synergistic lifespan extension in C. elegans. To understand the roles of translational regulation in this process, we performed polysomal profiling and identified translationally regulated ribosomal and cytochrome c (CYC-2.1) genes as key mediators of longevity. cyc-2.1 knockdown significantly extends lifespan by activating the intestinal mitochondrial unfolded protein response (UPRmt), mitochondrial fission, and AMP-activated kinase (AMPK). The germline serves as the key tissue for cyc-2.1 to regulate lifespan, and germline-specific cyc-2.1 knockdown non-autonomously activates intestinal UPRmt and AMPK. Furthermore, the RNA-binding protein GLD-1-mediated translational repression of cyc-2.1 in the germline is important for the non-autonomous activation of UPRmt and synergistic longevity of the daf-2 rsks-1 mutant. Altogether, these results illustrate a translationally regulated non-autonomous mitochondrial stress response mechanism in the modulation of lifespan by insulin-like signaling and S6K.

10.
Biomed Res Int ; 2019: 3487607, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31355256

RESUMO

Object: Retinal ischemia-reperfusion (I/R) injury is a common pathological process in many ophthalmic diseases; there are no effective therapeutic approaches available currently. Increasing evidence indicates that microglia mediated neuroinflammation plays an important role in the retinal I/R injury. In this study, we aimed to investigate the roles of chemokine receptor CXCR5 in the pathological process of retinal I/R injury model. Method: Retinal I/R injury model was established in CXCR5 knockout and wild mice by the acute elevation of intraocular pressure (AOH) for 60 minutes, and the eyes were harvested for further analyses. The cellular location of CXCR5 was detected by immunofluorescence staining; the expressions of CXCR5 and CXCL13 after I/R injury were analyzed by quantitative RT-PCR. The retinal microglia were detected as stained for Iba1 (+). Leakage of inflammatory cells was observed on the H&E stained cryosections. The protein expression and quantification of zonula occludens (ZO-1) were determined by Western blotting and densitometry. Capillary degeneration was identified on the intact retinal vasculatures prepared by trypsin digestion. Results: The number of activated microglia marked by Iba1 antibody in the retina was increased after retinal I/R injury in both KO and WT mice, more significant in KO mice. The leakage of inflammatory cells was observed largely at 2 days after injury, but there was no or little leakage at 7 days. The number of inflammatory cells (mainly neutrophils) was greater in CXCR5 KO mice than in WT mice, mainly located under internal limiting membrane. CXCR5 deficiency led to more ZO-1 degradation in CXCR5 KO mice compared to C57BL6 WT mice 2 days after reperfusion. The cellular capillaries were also significantly increased in the KO mice compared to the WT mice. Conclusion: Our findings suggest that the chemokine receptor CXCR5 may protect retina from ischemia-reperfusion injury by its anti-inflammatory effects. Thus, CXCR5 may be a promising therapeutic target for the treatment of retinal I/R injury.


Assuntos
Inflamação/genética , Receptores CXCR5/genética , Traumatismo por Reperfusão/genética , Retina/metabolismo , Animais , Proteínas de Ligação ao Cálcio/genética , Quimiocina CXCL13/genética , Regulação da Expressão Gênica/genética , Humanos , Inflamação/metabolismo , Inflamação/patologia , Pressão Intraocular/genética , Camundongos , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/fisiopatologia , Retina/patologia
11.
Endocr Pract ; 25(9): 899-907, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31170361

RESUMO

Objective: In early type 2 diabetes (T2DM), the administration of short-term intensive insulin therapy (IIT) can induce glycemic remission for a year thereafter, but this effect ultimately wanes. In this context, intermittently repeating short-term IIT could provide a strategy for maintaining the otherwise transient benefits of this intervention. However, the viability of this strategy would be contingent upon not inducing undesirable effects of insulin therapy such as excessive hypoglycemia and fat deposition. We thus sought to evaluate the effect of administering short-term IIT every 3 months on hypoglycemia, weight gain, and quality of life in early T2DM. Methods: In this 2-year pilot trial, 24 adults with T2DM of 2.0 ± 1.7 years duration and hemoglobin A1c of 6.4 (46 mmol/mol) ± 0.1% were randomized to 3 weeks of IIT (glargine, lispro) followed by either (1), repeat IIT for up to 2 weeks every 3 months or (2), daily metformin. IIT was titrated to target near-normoglycemia (premeal glucose 4 to 6 mmol/L; 2-hour postmeal <8 mmol/L). Participants were assessed every 3 months, with quality of life (QOL) evaluated annually. Results: The rate of hypoglycemia (<3.5 mmol/L) was low in the metformin and intermittent IIT arms (0.37 versus 0.95 events per patient-year; P = .28). There were no differences between the groups in changes over time in overall, central, or hepatic fat deposition (as reflected by weight [P = .10], waist-to-hip ratio [P = .58], and alanine aminotransferase [P = .64], respectively). Moreover, there were no differences between the groups in QOL at 1- and 2-years. Conclusion: Intermittent short-term IIT may be safely administered in early T2DM without excessive adverse impact on hypoglycemic risk, anthropometry, or QOL. Abbreviations: ALT = alanine aminotransferase; HbA1c = hemoglobin A1c; IIT = intensive insulin therapy; ISSI-2 = insulin secretion-sensitivity index-2; OGTT = oral glucose tolerance test; QOL = quality of life; SF-36 = medical outcomes study 36-item short-form health survey; T2DM = type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2 , Hipoglicemia , Insulina/uso terapêutico , Glicemia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Hemoglobina A Glicada , Humanos , Hipoglicemiantes , Qualidade de Vida , Ganho de Peso
12.
Pulm Pharmacol Ther ; 57: 101803, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31085231

RESUMO

Pulmonary fibrosis is a progressive fibrotic lung disease with a paucity of therapeutic options. Here we investigated the potential roles of probucol, a cholesterol-lowering drug with potent anti-oxidation properties, on pulmonary epithelial-mesenchymal transition (EMT) and fibrosis. We found that bleomycin-induced lung fibrosis was associated with increased transforming growth factor (TGF)-ß1, α-smooth muscle actin (α-SMA) and decreased E-cadherin expression in lung tissues, indicating EMT formation. Bleomycin treatment resulted in an induction of oxidative stress in lung tissues. Probucol treatment attenuated bleomycin-induced TGF-ß1 production, EMT and pulmonary fibrosis, meanwhile it suppressed bleomycin-induced oxidative stress. Bleomycin treatment resulted in decreases in protein expressions of Sirtuin 3 (SIRT3) in the lung, which were restored by ROS scavenger NAC and probucol treatment, suggesting that probucol might restore SIRT3 expression by suppressing bleomycin-induced oxidative stress. In the mouse alveolar type II epithelial cell line MLE-12, probucol treatment leads to an increase in SIRT3 expression in bleomycin-treated AT-II cells, which might contribute to the inhibitory effect of probucol on EMT through suppressing hypoxia inducible factor (HIF)-1α/TGF-ß1 pathway. In addition, probucol inhibited bleomycin-induced macrophage infiltration in the lung. Bleomycin decreased SIRT3 protein expression, whereas increased HIF-1α activation and TGF-ß1 release in the mouse macrophage cell line RAW264.7, which were attenuated by probucol treatment. Taken together, the present study suggests that probucol may ameliorate EMT and lung fibrosis through restoration of SIRT3 expression. The data obtained in this study provides proof for the idea that probucol may be a potential therapeutic option for the treatment of pulmonary fibrosis.

15.
Curr Microbiol ; 76(2): 237-247, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30569322

RESUMO

Diet is known to play a major role in determining the composition and function of the gut microbiota. Previous studies have often focused on the immediate effects of dietary intervention. How dietary history prior to a given dietary intervention influences the gut microbiota is, however, not well understood. To assess the influence of dietary history, in this study, mice with different dietary histories were subjected to the same dietary interventions, and the gut microbial communities of these mice were characterized by 16S rDNA sequencing. We found that dietary history played a long-lasting role in the composition of the gut microbiota when the dietary switch was moderate. In sharp contrast, such effects nearly vanished when the diet was switched to certain extreme dietary conditions. Interestingly, the abundance of Akkermansia, a bacterial genus associated with loss of body weight, was elevated dramatically in mice subjected to a diet composed exclusively of meat. Our results revealed a more complex picture of the influence of dietary history on gut microbiota than anticipated.


Assuntos
Bactérias/classificação , Dieta , Fezes/microbiologia , Microbioma Gastrointestinal , Animais , Bactérias/isolamento & purificação , Camundongos , Camundongos Endogâmicos BALB C , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
16.
J Biomed Mater Res B Appl Biomater ; 107(6): 1854-1863, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30550636

RESUMO

Nickel-titanium (NiTi) alloy is an attractive material for biomedical implant applications. In this study, the effects of laser shock peening (LSP) on the biocompatibility, corrosion resistance, ion release rate and hardness of NiTi were characterized. The cell culture study indicated that the LSP-treated NiTi samples had lower cytotoxicity and higher cell survival rate than the untreated samples. Specifically, the cell survival rate increased from 88 ± 1.3% to 93 ± 1.1% due to LSP treatment. LSP treatment was shown to significantly decrease the initial Ni ion release rate compared with that of the untreated samples. Electrochemical tests indicated that LSP improved the corrosion resistance of the NiTi alloy in simulated body fluid, with a decrease in the corrosion current density from 1.41 ± 0.20 µA/cm2 to 0.67 ± 0.24 µA/cm2 . Immersion tests showed that calcium deposition was significantly enhanced by LSP. In addition, the hardness of NiTi alloy increased from 226 ± 3 HV before LSP to 261 ± 3 HV after LSP. These results demonstrated that LSP is a promising surface modification method that can be used to improve the mechanical properties, corrosion resistance and biocompatibility of NiTi alloy for biomedical applications. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1854-1863, 2019.

17.
Acta Physiol (Oxf) ; 225(2): e13177, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30136377

RESUMO

AIMS: Clinical trials have shown the beneficial effects of exercise training against pulmonary fibrosis. This study aimed to investigate whether prophylactic intervention with exercise training attenuates lung fibrosis via modulating endogenous hydrogen sulphde (H2 S) generation. METHODS: First, ICR mice were allocated to Control, Bleomycin, Exercise, and Bleomycin + Exercise groups. Treadmill exercise began on day 1 and continued for 4 weeks. A single intratracheal dose of bleomycin (3 mg/kg) was administered on day 15. Second, ICR mice were allocated to Control, Bleomycin, H2 S, and Bleomycin + H2 S groups. H2 S donor NaHS (28 µmol/kg) was intraperitoneally injected once daily for 2 weeks. RESULTS: Bleomycin-treated mice exhibited increased levels of collagen deposition, hydroxyproline, collagen I, transforming growth factor (TGF)-ß1, Smad2/Smad3/low-density lipoprotein receptor-related proteins (LRP-6)/glycogen synthase kinase-3ß (GSK-3ß) phosphorylation, and Smad4/ß-catenin expression in lung tissues (P < 0.01), which was alleviated by exercise training (P < 0.01 except for Smad4 and phosphorylated GSK-3ß: P < 0.05). Bleomycin-induced lung fibrosis was associated with increased α smooth muscle actin (α-SMA) and decreased E-cadherin expression (P < 0.01). Double immunofluorescence staining showed the co-localization of E-cadherin/α-SMA, indicating epithelial-mesenchymal transition (EMT) formation, which was ameliorated by exercise training. Moreover, exercise training restored bleomycin-induced downregulation of cystathionine-ß-synthase (CBS) and cystathionine-γ-lyase (CSE) expression, as well as H2 S generation in lung tissue (P < 0.01). NaHS treatment attenuated bleomycin-induced TGF-ß1 production, activation of LRP-6/ß-catenin signalling, EMT and lung fibrosis (P < 0.01 except for ß-catenin: P < 0.05). CONCLUSION: Exercise training restores bleomycin-induced downregulation of pulmonary CBS/CSE expression, thus contributing to the increased H2 S generation and suppression of TGF-ß1/Smad and LRP-6/ß-catenin signalling pathways, EMT and lung fibrosis.

18.
Diabetes Obes Metab ; 2018 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-30565366

RESUMO

The current era of large-scale clinical trials in diabetes has generated thousands of biological samples from study participants that are being stored long-term under frozen conditions for the future measurement of analytes of interest. Insulin and C-peptide are two such analytes that can provide insight into underlying pathophysiological processes (insulin sensitivity and ß-cell function). However, the validity of the inferences that may be drawn from such future measurements is contingent on the stability of these analytes after long-term frozen storage. We conducted the present study to determine the stability of insulin and C-peptide concentrations that were first measured on fresh serum at the time of collection, followed by frozen storage at -80°C for >5 years and then repeat measurement. Bland-Altman analyses revealed good agreement between the repeated insulin measurements and between the repeated C-peptide measurements. The concordance correlation coefficient (CCC) confirmed reproducibility for both insulin (CCC 0.98, 95% confidence interval [CI] 0.96-0.99) and C-peptide (CCC 0.91, 95% CI 0.84-0.95); thus, insulin and C-peptide measurements are both stable and reproducible after long-term frozen storage of serum samples.

20.
Mater Sci Eng C Mater Biol Appl ; 93: 12-20, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30274044

RESUMO

Hierarchical structures on metallic implants can enhance the interaction between cells and implants and thus increase their biocompatibility. However, it is difficult to directly fabricate hierarchical structures on metallic implants. In this study, we used a simple one-step method, ultrasonic nanocrystal surface modification (UNSM), to fabricate hierarchical surface structures on a nickel-titanium (NiTi) alloy. During UNSM, a tungsten carbide ball hits metal surfaces at ultrasonic frequency. The overlapping of the ultrasonic strikes generates hierarchical structures with microscale grooves and embedded nanoscale wrinkles. Cell culture experiments showed that cells adhere better and grow more prolifically on the UNSM-treated samples. Compared with the untreated samples, the UNSM-treated samples have higher corrosion resistance. In addition, the surface hardness increased from 243 Hv to 296 Hv and the scratch hardness increased by 22%. Overall, the improved biocompatibility, higher corrosion resistance, and enhanced mechanical properties demonstrate that UNSM is a simple and effective method to process metallic implant materials.


Assuntos
Ligas/química , Teste de Materiais , Células-Tronco Mesenquimais/metabolismo , Nanopartículas/química , Ondas Ultrassônicas , Adesão Celular , Linhagem Celular , Humanos , Células-Tronco Mesenquimais/citologia , Propriedades de Superfície
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA