Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
1.
J Vis Exp ; (203)2024 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-38251798

RESUMO

In this paper, the directional gradient histogram technology is employed to extract the features of concrete image samples captured under different vibration states. The support vector machine (SVM) is utilized to learn the relationship between image features and vibration state. The machine learning results are subsequently used to assess the feasibility of the concrete vibration state. Simultaneously, the influence mechanism of the calculation parameters of the directional gradient histogram on the recognition accuracy is analyzed. The results demonstrate the feasibility of using the directional gradient histogram-SVM technology to identify the vibration state of concrete. The recognition accuracy initially increases and then decreases as the block size of the directional gradient, or the number of statistical intervals increases. The recognition accuracy also decreases linearly with the increase of the binarization threshold. By using sample images with a resolution of 1024 pixels x 1024 pixels and optimizing the feature extraction parameters, a recognition accuracy of 100% can be attained.


Assuntos
Máquina de Vetores de Suporte , Vibração , Aprendizado de Máquina , Reconhecimento Psicológico , Tecnologia
2.
Phys Chem Chem Phys ; 26(5): 4091-4098, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38226486

RESUMO

Rechargeable lithium-ion batteries, as the most advanced energy storage devices currently available, urgently require the development of cathode materials with high capacity, large specific energy, and fast charge/discharge performance to satisfy the continuous technological innovation. Here, a Li-rich Mn-based ternary cathode material Li7/6Nil/6Co1/6Mn1/2O2 is designed, and the geometrical structure, electronic properties, and thermodynamic properties of this material are investigated employing the first-principles method. Six layered structure models are established by adjusting the ratio of Ni, Co, and Mn elements, and the effects of various elements on the material properties are evaluated. Based on the performance of Ni, Co, and Mn in the structure, Li1.2Ni0.15Co0.1Mn0.55O2 features favorable electrical conductivity, thermal conductivity, and excellent stability. This material obtained through co-precipitation using a high temperature solid phase synthesis presents a high actual capacity (245 mA h g-1) and superior cycling performance (the capacity retention rate of the material is 84% after 60 cycles at 0.2C). This effort discusses the Li-rich Mn-based cathode materials in terms of the structural basis, reaction mechanism, and application exploration, which are valuable for guiding their theoretical design, optimization modification, and industrial application.

3.
Int J Nurs Knowl ; 35(2): 117-129, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36843066

RESUMO

PURPOSE: Breast cancer is the most common cancer type worldwide, with its survivors often experiencing physical and psychosocial health problems. Wearable device use is an innovative and effective way to promote physical activity and improve health-related outcomes in breast cancer survivors; however, the current evidence is unclear. We aimed to determine the effects of wearable devices on physical activity and health-related outcomes in breast cancer survivors. METHODS: PubMed, Embase, Web of Science, and Cochrane Library databases were searched to identify eligible studies from inception to September 2022. Additional relevant studies were obtained from the reference lists of the identified studies. Two reviewers independently screened the eligible studies, appraised the risk of bias, and extracted the data. Meta-analysis was conducted using Review Manager version 5.3. FINDINGS: Sixteen randomized controlled trials were included. Physical activity tracking and pedometer-based interventions improved moderate-intensity physical activity (standardized mean difference [SMD] = 0.32, 95% confidence interval [CI]: 0.17-0.46, p < 0.0001), moderate-to-vigorous physical activity (SMD = 0.85, 95%CI: 0.38-1.32, p = 0.0004), total physical activity (SMD = 0.51, 95%CI: 0.12-0.90, p = 0.01), quality of life (SMD = 0.17, 95%CI: 0.03-0.31, p = 0.01), physical function (SMD = 0.21, 95%CI: 0.04-0.38, p = 0.02), and mood state profiles (SMD = -0.58, 95%CI: -1.13 to 0.02, p = 0.04) in breast cancer survivors. However, the effects of low-intensity physical activity, vigorous-intensity physical activity, fatigue, anxiety, depression, and sleep quality could not be ascertained. CONCLUSIONS: Physical activity tracking and pedometer-based interventions were effective in increasing physical activity and improving health-related outcomes in breast cancer survivors. IMPLICATIONS FOR NURSING PRACTICE: This review offers availability of credible evidence supporting the potential usefulness and effectiveness of wearable physical activity trackers on physical activity and health-related outcomes in breast cancer survivors.


Assuntos
Neoplasias da Mama , Sobreviventes de Câncer , Dispositivos Eletrônicos Vestíveis , Humanos , Feminino , Qualidade de Vida , Depressão , Exercício Físico , Sobreviventes
4.
Chem Asian J ; 18(24): e202300873, 2023 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-37871137

RESUMO

Cyclopropanes are important structural motifs found in many natural products and are essential to the pharmaceutical and agrochemical industries. Here, we report a bioinspired cobalt catalyst that catalyzes the intermolecular cyclopropanation of various terminal olefins using ethyl diazoacetate (EDA) in high efficiency. This cobalt catalytic system is operationally simple under very mild conditions, enabling the synthesis of cyclopropane products with remarkable yields in short reaction time. Preliminary mechanistic studies suggest the presence of cobalt carbene radical species during the reaction.

5.
Br J Clin Pharmacol ; 89(11): 3401-3410, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37387195

RESUMO

AIMS: Advanced age is an important risk factor for adverse events during procedural sedation. Remimazolam is safe and effective in gastroscopic sedation. However, the ideal dose and application for older patients are not well known. We aim to investigate its 95% effective dose (ED95) for older patients undergoing gastroscopy and to assess its safety and efficacy, with propofol as the comparison. METHODS: The trial consists of 2 parts, patients aged >65 years and scheduled for outpatient painless gastroscopy were enrolled. In the first part, Dixon's up-and-down methodology was used to determine the ED95 of remimazolam besylate and propofol for gastroscopic insertion, in combination with 0.2 µg/kg remifentanil. In the second part, patients in each group received 0.2 µg/kg remifentanil and ED95 dose of the study drugs for sedation induction, supplemental doses were added to maintain sedation depth when necessary. The primary outcome was the incidence of adverse events. The secondary outcome was the recovery time. RESULTS: The ED95 of remimazolam besylate and propofol induction were 0.2039 (95% confidence interval 0.1753-0.3896) mg/kg and 1.9733 (95% confidence interval 1.7346-3.7021) mg/kg respectively. Adverse events were reported in 26 (40.6%) patients in the remimazolam group and 54 (83.1%) in the propofol group (P < .0001), whereas the remimazolam group presented a higher incidence of hiccups (P = .0169). Besides, the median time to awakening was approximately 1 min shorter with remimazolam than with propofol (P < .05). CONCLUSION: For older patients undergoing gastroscopy, the ED95 dose of remimazolam is a safer alternative than propofol when inducing the same sedation depth.


Assuntos
Gastroscopia , Propofol , Humanos , Propofol/efeitos adversos , Remifentanil , Benzodiazepinas , Hipnóticos e Sedativos/efeitos adversos
6.
Polymers (Basel) ; 15(9)2023 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-37177195

RESUMO

Rubber concrete (RC) exhibits high durability due to the rubber admixture. It is widely used in a large number of fatigue-resistant structures. Mesoscale studies are used to study the composition of polymers, but there is no method for fatigue simulation of RC. Therefore, this paper presents a finite element modeling approach to study the fatigue problem of RC on the mesoscale, which includes the random generation of the main components of the RC mesoscale structure. We also model the interfacial transition zone (ITZ) of aggregate mortar and the ITZ of rubber mortar. This paper combines the theory of concrete damage to plastic with the method of zero-thickness cohesive elements in the ITZ, and it is a new numerical approach. The results show that the model can simulate reasonably well the random damage pattern after RC beam load damage. The damage occurred in the middle of the beam span and tended to follow the ITZ. The model can predict the fatigue life of RC under various loads.

7.
Polymers (Basel) ; 15(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36679189

RESUMO

The addition of rubber to concrete improves resistance to chloride ion attacks. Therefore, rapidly determining the chloride permeability coefficient (DCI) of rubber concrete (RC) can contribute to promotion in coastal areas. Most current methods for determining DCI of RC are traditional, which cannot account for multi-factorial effects and suffer from low prediction accuracy. Machine learning (ML) techniques have good non-linear learning capabilities and can consider the effects of multiple factors compared with traditional methods. However, ML models easily fall into the local optimum due to their parameters' influence. Therefore, a mixed whale optimization algorithm (MWOA) was developed in this paper to optimize ML models. The main strategies are to introduce Tent mapping to expand the search range of the algorithm, to use an adaptive t-distribution dimension-by-dimensional variation strategy to perturb the optimal fitness individual to thereby improve the algorithm's ability to jump out of the local optimum, and to introduce adaptive weights and adaptive probability threshold values to enhance the adaptive capacity of the algorithm. For this purpose, data were collected from the published literature. Three machine learning models, Extreme Learning Machine (ELM), Random Forest (RF), and Elman Neural Network (ELMAN), were built to predict the DCI of RC, and the three models were optimized using MWOA. The calculations show that the MWOA is effective with the optimized ELM, RF, and ELMAN models improving the prediction accuracy by 54.4%, 62.9%, and 36.4% compared with the initial model. The MWOA-ELM model was found to be the optimal model after a comparative analysis. The accuracy of the multiple linear regression model (MRL) and the traditional mathematical model is calculated to be 87.15% and 85.03%, which is lower than that of the MWOA-ELM model. This indicates that the ML model that is optimized using the improved whale optimization algorithm has better predictive ability than traditional models, providing a new option for predicting the DCI of RC.

8.
Materials (Basel) ; 15(11)2022 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-35683231

RESUMO

Conventional neural networks tend to fall into local extremum on large datasets, while the research on the strength of rubber concrete using intelligent algorithms to optimize artificial neural networks is limited. Therefore, to improve the prediction accuracy of rubber concrete strength, an artificial neural network model with hybrid algorithm optimization was developed in this study. The main strategy is to mix the simulated annealing (SA) algorithm with the particle swarm optimization (PSO) algorithm, using the SA algorithm to compensate for the weak global search capability of the PSO algorithm at a later stage while changing the inertia factor of the PSO algorithm to an adaptive state. For this purpose, data were first collected from the published literature to create a database. Next, ANN and PSO-ANN models are also built for comparison while four evaluation metrics, MSE, RMSE, MAE, and R2, were used to assess the model performance. Finally, compared with empirical formulations and other neural network models, the result shows that the proposed optimized artificial neural network model successfully improves the accuracy of predicting the strength of rubber concrete. This provides a new option for predicting the strength of rubber concrete.

9.
Talanta ; 221: 121399, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33076054

RESUMO

Herein, we present a facile strategy for dopamine (DA) sensing by a water-stable MOF of {[Tb(Cmdcp)(H2O)3]2(NO3)2·5H2O}n (1, H3CmdcpBr = N-carboxymethyl-(3,5-dicarboxyl)pyridinium bromide). Without any post-modification, MOF 1 functions as an effective fluorescent sensor for the label-free detection of DA with the detection limit of 0.41 µM (S/N = 3). Under the optimum condition of 80 °C, pH 9 for 80 min in Tris-HCl with natural ambient oxygen, DA polymerizes to give polydopamine (pDA), which adheres to the surface of MOF 1 and quenched its green luminescence thoroughly. The sensing process is visible to naked eyes under 365 nm UV light irradiation due to the partial overlap of its excitation spectrum with the absorption spectrum of pDA. The sensing process is not interfered by coexisting of bio-related organic substances, such as glucose (Glu), 5-hydroxytryptamine (5-HT), homocysteine (Hcy), ascorbic acid (AA), uric acid (UA), cysteine (Cys), glutathione (GSH), as well as the presence of metal ions, including Zn2+, Ca2+, Mg2+, Ni2+ and Co2+. The sensing process is also adaptable in biological fluids of serum and urine with satisfactory recoveries ranging from 96.14% to 104.32%.

10.
Spectrochim Acta A Mol Biomol Spectrosc ; 247: 119084, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33128945

RESUMO

Herein, a luminescent water-stable terbium-based metal-organic framework (MOF) {[Tb(Cmdcp)(H2O)3]2(NO3)2·5H2O}n (1, H3CmdcpBr = N-carboxymethyl-(3,5-dicarboxyl)pyridinium bromide) has been synthesized and used for the recyclable sensing of PO43- and Al3+ in tandem. MOF 1 acts as a fluorescent sensor for PO43- by the luminescence "turn-off" mechanism with high selectivity over other anions, such as F-, Cl-, Br-, I-, NO3-, H2PO4-, HSO4-, HCO3-, HSO3-, SO42-, CO32- and HPO42-. The formed PO43-@1 complex further acts as the Al3+ sensor with the luminescence "turn-on" mechanism, also with high selectivity over diverse inorganic cations of Fe2+, Mn2+, Co2+, Ni2+, Hg2+, Na+, K+, Li+, Ag+, Mg2+, Ca2+, Cd2+, Pb2+, Cu2+, and Zn2+. The detection process for both PO43- and Al3+ can be directly observed with naked eyes under the UV light at 365 nm. The detection limits for PO43- and Al3+ are 1.1 µM and 6.6 µM, respectively. Such a sensing cycle is further transferable to urine and serum samples with a satisfactory near-quantitative recovery, highlighting its good potential in biologically relevant applications.

11.
J Cell Mol Med ; 24(24): 14184-14194, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-33111502

RESUMO

As a cis-acting non-depolarizing neuromuscular blocker through a nicotinic acetylcholine receptor (nAChR), cisatracurium (CAC) is widely used in anaesthesia and intensive care units. nAChR may be present on Leydig cells to mediate the action of CAC. Here, by Western blotting, immunohistochemistry and immunofluorescence, we identified that CHRNA4 (a subunit of nAChR) exists only on rat adult Leydig cells. We studied the effect of CAC on the synthesis of testosterone in rat adult Leydig cells and mouse MLTC-1 tumour cells. Rat Leydig cells and MLTC-1 cells were treated with CAC (5, 10 and 50 µmol/L) or nAChR agonists (50 µmol/L nicotine or 50 µmol/L lobeline) for 12 hours, respectively. We found that CAC significantly increased testosterone output in rat Leydig cells and mouse MLTC-1 cells at 5 µmol/L and higher concentrations. However, nicotine and lobeline inhibited testosterone synthesis. CAC increased intracellular cAMP levels, and nicotine and lobeline reversed this change in rat Leydig cells. CAC may increase testosterone synthesis in rat Leydig cells and mouse MLTC-1 cells by up-regulating the expression of Lhcgr and Star. Up-regulation of Scarb1 and Hsd3b1 expression by CAC was also observed in rat Leydig cells. In addition to cAMP signal transduction, CAC can induce ERK1/2 phosphorylation in rat Leydig cells. In conclusion, CAC binds to nAChR on Leydig cells, and activates cAMP and ERK1/2 phosphorylation, thereby up-regulating the expression of key genes and proteins in the steroidogenic cascade, resulting in increased testosterone synthesis in Leydig cells.


Assuntos
Atracúrio/análogos & derivados , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Receptores Nicotínicos/metabolismo , Testosterona/biossíntese , Animais , Atracúrio/farmacologia , Biomarcadores , Vias Biossintéticas/efeitos dos fármacos , Células Cultivadas , AMP Cíclico/metabolismo , Imunofluorescência , Regulação da Expressão Gênica/efeitos dos fármacos , Imuno-Histoquímica , Hormônio Luteinizante/metabolismo , Hormônio Luteinizante/farmacologia , Masculino , Camundongos , Fosforilação , Ratos , Receptores Nicotínicos/genética , Esteroides/biossíntese , Testículo/metabolismo
12.
Ecotoxicol Environ Saf ; 203: 111053, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888615

RESUMO

Vinclozolin is a common dicarboximide fungicide used to protect crops from diseases. It is also an endocrine disruptor and is thought to be related to abnormalities of the reproductive tract. However, its mechanism of inducing abnormalities of the male reproductive tract is still unclear. The purpose of this study was to study the effect of gestational vinclozolin exposure on the development of rat fetal Leydig cells. Female pregnant Sprague-Dawley rats were exposed to vinclozolin (0, 25, 50, and 100 mg/kg body weight/day) by gavage from gestational day 14-21. Vinclozolin dose-dependently reduced serum testosterone levels at doses of 50 and 100 mg/kg and the anogenital distance at 100 mg/kg. RNA-seq, qPCR, and Western blotting showed that vinclozolin down-regulated the expression of Nr5a1, Sox9, Lhcgr, Cyp11a1, Hsd3b1, Hsd17b3, Amh, Pdgfa, and Dhh and their encoded proteins. Vinclozolin reduced the number of NR2F2-positive stem Leydig cells at a dose of 100 mg/kg and enhanced autophagy in the testes. In conclusion, vinclozolin disrupts reproductive tract development and testis development in male fetal rats via several pathways.


Assuntos
Disruptores Endócrinos/toxicidade , Fungicidas Industriais/toxicidade , Organogênese/efeitos dos fármacos , Oxazóis/toxicidade , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Testículo/efeitos dos fármacos , Animais , Autofagia/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Células Intersticiais do Testículo/patologia , Masculino , Gravidez , Ratos , Ratos Sprague-Dawley , Testículo/embriologia , Testículo/patologia , Testosterona/sangue
13.
Food Chem Toxicol ; 142: 111482, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32525071

RESUMO

Di-n-butyl phthalate (DBP) is widely used in consumer products as a plasticizer. Here, we report a natural product taxifolin that can attenuate developmental and reproductive toxicity of DBP. Pregnant rats were daily gavaged with 500 mg/kg DBP alone or together with taxifolin (10 and 20 mg/kg) from gestational day (GD) 12-21. At GD21, sera and testes of male fetus were collected. DBP significantly lowered serum testosterone level at 500 mg/kg and taxifolin can completely reverse its action. DBP caused abnormal aggregation of fetal Leydig cells and taxifolin can reverse it. DBP down-regulated the expression of the genes of cholesterol side-chain cleavage enzyme (Cyp11a1), 17ß-hydroxysteroid dehydrogenase 3 (Hsd17b3), and insulin-like 3 (Insl3) and taxifolin can reverse its action. DBP increased malondialdehyde levels and decreased superoxide dismutase and glutathione peroxidase expression and taxifolin can reverse it. DBP increased incidence of multinucleated gonocytes and taxifolin can prevent it. Moreover, DBP lowered sirtuin 1 (SIRT1)/peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) and phosphorylated AMP-activated protein kinase (pAMPK) signalling and taxifolin antagonized DBP. In conclusion, in utero exposure to DBP caused developmental/reproductive toxicity of male offspring via increasing reactive oxygen species and taxifolin is an effective food component that completely reverses DBP-mediated action.


Assuntos
Antioxidantes/farmacologia , Dibutilftalato/toxicidade , Plastificantes/toxicidade , Quercetina/análogos & derivados , Testículo/efeitos dos fármacos , Animais , Feminino , Masculino , Exposição Materna , Quercetina/farmacologia , Ratos , Ratos Sprague-Dawley , Testículo/embriologia
14.
Environ Pollut ; 263(Pt B): 114357, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32229375

RESUMO

Zearalenone is a phenolic Fusarium mycotoxin, which is ubiquitous in human and animal feedstuff and often co-occurs with other mycotoxins. ZEA has been reported to disturb Leydig cell function and even cause the apoptosis to the Leydig cells. However, the effects of gestational exposure to zearalenone on fetal Leydig cells and the underlying mechanism remain unknown. Sprague Dawley dams were daily gavaged with 0, 2.5, 5, 10, and 20 mg/kg body weight ZEA from gestational day 14-21. On gestational day 21, rats were euthanized and serum testosterone levels were measured, and testes were collected for further evaluation of Leydig cell number, cell size, gene, and protein expression. Zearalenone significantly decreased anogenital distance and its index of male fetus, serum testosterone levels, Leydig cell proteins (SCARB1, STAR, CYP11A1, CYP17A1, and INSL3), and fetal Leydig cell number at 10 and/or 20 mg/kg by delaying the commitment of stem Leydig cells into the Leydig cell lineage and proliferation. Further study found that Notch signaling (RFNG, PSEN1, NOTCH1, and NOTCH3) was up-regulated by zearalenone. In conclusion, gestational exposure to high doses of zearalenone (10 and 20 mg/kg) blocks fetal Leydig cell development, thus possibly causing the anomalies of the male reproductive tract.


Assuntos
Células Intersticiais do Testículo , Zearalenona , Animais , Feminino , Feto , Humanos , Masculino , Exposição Materna , Ratos , Ratos Sprague-Dawley , Testículo , Testosterona
15.
Talanta ; 210: 120596, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987206

RESUMO

A zwitterionic three-dimensional (3D) metal-organic framework (MOF) of {[Cu(Cdcbp)(bipy)]·4H2O}n (1) has been synthesized and characterized (H3CdcbpBr = 3-carboxyl-(3,5-dicarboxybenzyl)-pyridinium bromide; bipy = 4,4'-bipyridine). MOF 1 exhibits a variety of structural traits, such as ligand conjugated, positively charged pyridinium center, and Cu(II) cations that collectively enable its efficient hybridization with the flexible, negatively charged, single-stranded, and thymine-rich (T-rich) DNA. The T-rich DNA is labeled with carboxyfluorescein (FAM) fluorescent probe (characterized as P-DNA), but the resultant MOF 1 - P-DNA hybrid (characterized as P-DNA@1) is non-emissive (off-state) because of the fluorescent quenching by MOF 1. The P-DNA@1 hybrid functions as an effective and selective sensor for Hg2+ due to the formation of rigid hairpin-like T-Hg2+-T double-stranded DNA (ds-DNA@Hg2+) which is subsequently ejected by MOF 1, triggering a recovery of the P-DNA fluorescence (on-state). Subsequent addition of biothiols further sequestrates Hg2+ from the ds-DNA@Hg2+ duplex driven by the stronger Hg-S coordination, thus release the P-DNA and, in turn, resorbed by MOF 1 to regain the initial hybrid (off-state). P-DNA@1 hybrid thus detects Hg2+ and biothiols sequentially via a fluorescence "off-on-off" mechanism. The limits of detection (LOD) for Hg2+, biothiols, including cysteine (Cys), glutathione (GSH) and homocysteine (Hcy) are 3.0, 14.2, 15.1 and 8.0 nM, respectively, with the detection time of 60 min for Hg2+, and instantaneous detection for all the three biothiols. The detection mechanism is further confirmed by circular dichroism (CD), fluorescence anisotropy (FA), binding constant and molecular simulation. This sequential detection of Hg2+ and biothiols counter-proofs the presence of each other and may shed light to the occurrence of related diseases, such as neurodegenerative disorders of Parkinson's disease (PD), and Alzheimer's disease (AD).


Assuntos
Cobre/química , Corantes Fluorescentes/química , Mercúrio/análise , Estruturas Metalorgânicas/química , Simulação de Dinâmica Molecular , Compostos de Sulfidrila/análise , Dicroísmo Circular , Cristalografia por Raios X , Corantes Fluorescentes/síntese química , Estruturas Metalorgânicas/síntese química , Estrutura Molecular , Espectrofotometria Infravermelho
16.
Chemosphere ; 243: 125149, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31765896

RESUMO

Triphenyltin is an organotin, which is widely used as a fungicide in agriculture. Here, we reported the effects of triphenyltin on adrenal function in adult male rats. Adult male Sprague Dawley rats were daily gavaged with triphenyltin (0, 0.5, 1, and 2 mg/kg body weight) from postnatal day 56-86. Triphenyltin significantly decreased serum corticosterone levels at 1 and 2 mg/kg without affecting serum levels of aldosterone and adrenocorticotropic hormone. Triphenyltin increased thickness of zona glomerulosa without affecting that of zona fasciculata. Triphenyltin did not affect cell number in zona fasciculata and zona glomerulosa. Triphenyltin down-regulated the expression of Scarb1, Star, Cyp11a1, Hsd3b1, Cyp21, Cyp11b1, and Hsd11b1 at 1 and/or 2 mg/kg while it up-regulated the expression of At1, Nr4a2, and Hsd11b2 at 2 mg/kg. Triphenyltin activated the phosphorylation of AMPKα while suppressed the phosphorylation of AKT1 and SIRT1/PGC-1α in rat adrenals in vivo and H295R cells in vitro. In vitro, triphenyltin also induced ROS production in H295R cells at 100 nM, a concentration at which no apoptosis was induced. In conclusion, triphenyltin disrupts glucocorticoid synthesis in rat adrenal cortex via several mechanisms: 1) lowering AKT1 phosphorylation and SIRT1/PGC-1α levels; 2) activating AMPKα; and 3) possibly inducing ROS production.


Assuntos
Córtex Suprarrenal/efeitos dos fármacos , Fungicidas Industriais/toxicidade , Compostos Orgânicos de Estanho/toxicidade , Hormônio Adrenocorticotrópico , Aldosterona , Animais , Corticosterona/metabolismo , Regulação para Baixo/efeitos dos fármacos , Fungicidas Industriais/metabolismo , Masculino , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Fosforilação , Ratos , Ratos Sprague-Dawley , Sirtuína 1/metabolismo , Testes de Toxicidade Crônica , Zona Glomerulosa/efeitos dos fármacos
17.
Front Pharmacol ; 10: 760, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31333471

RESUMO

Background: Propofol is a widely used anesthetic. Whether propofol inhibits androgen production by rat Leydig cells and the underlying mechanism remains unclear. The objective of the current study was to examine the effects of propofol exposure to rat primary immature Leydig cells and to define propofol-induced inhibition of steroidogenic enzymes in both rat and human testes in vitro. Methods: Immature Leydig cells were purified from 35-day-old male Sprague-Dawley rats and were exposed to propofol for 3 h. The androgen production by Leydig cells under basal, luteinizing hormone, 8bromo-cAMP, and steroid-substrate stimulated conditions and gene expression of Leydig cells after exposure to propofol were measured. Immature Leydig cells were treated with propofol for 3 h and switched to propofol-free medium for additional 3 and 9 h to test whether propofol-induced inhibition is reversible. 3H-Steroids were used to evaluate the direct action of propofol on cytochrome P450 cholesterol side chain cleavage (CYP11A1), 3ß-hydroxysteroid dehydrogenase (HSD3B), cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1), and 17ß-hydroxysteroid dehydrogenase 3 (HSD17B3) activities in rat and human testes in vitro. Results: Propofol significantly lowered luteinizing hormone and 8bromo-cAMP stimulated androgen production by Leydig cells after 3-h exposure. Further investigation showed that propofol down-regulated the expression of Cyp11a1 and Cyp17a1 and their proteins at 5 and 50 µM, although it up-regulated Lhcgr expression at 50 µM. Propofol significantly suppressed phosphorylation of ERK1/2 and induced ROS production in immature Leydig cells at 5 and 50 µM. Propofol significantly induced apoptosis of immature Leydig cells at 50 µM. Propofol specifically inhibited rat and human testis HSD3B activities in vitro. The half maximal inhibitory concentrations of propofol for rat and human HSD3B enzymes were 1.011 ± 0.065 and 3.498 ± 0.067 µM, respectively. The mode of action of propofol of inhibiting HSD3B was competitive when pregnenolone was added. At 50 µM, propofol did not directly inhibit rat and human testis CYP11A1, CYP17A1, and HSD17B3 activities in vitro. Conclusion: Propofol inhibits androgen production via both directly inhibiting HSD3B activity and down-regulating Cyp11a1 and Cyp17a1 expression in Leydig cells. Suppression of steroidogenic enzymes is presumably associated with the lower production of androgen by Leydig cells after propofol treatment. However, propofol-induced inhibition on androgen production is reversible.

18.
J Cell Mol Med ; 23(8): 5618-5631, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31222931

RESUMO

Fibroblast growth factor homologous factor 1 (FHF1) is an intracellular protein that does not bind to cell surface fibroblast growth factor receptor. Here, we report that FHF1 is abundantly present in Leydig cells with up-regulation during its development. Adult male Sprague Dawley rats were intraperitoneally injected with 75 mg/kg ethane dimethane sulphonate (EDS) to ablate Leydig cells to initiate their regeneration. Then, rats daily received intratesticular injection of FHF1 (0, 10 and 100 ng/testis) from post-EDS day 14 for 14 days. FHF1 increased serum testosterone levels without affecting the levels of luteinizing hormone and follicle-stimulating hormone. FHF1 increased the cell number staining with HSD11B1, a biomarker for Leydig cells at the advanced stage, without affecting the cell number staining with CYP11A1, a biomarker for all Leydig cells. FHF1 did not affect PCNA-labelling index in Leydig cells. FHF1 increased Leydig cell mRNA (Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, Hsd17b3, Insl3, Nr5a1 and Hsd11b1) and their protein levels in vivo. FHF1 increased preadipocyte biomarker Dlk1 mRNA level and decreased fully differentiated adipocyte biomarker (Fabp4 and Lpl) mRNA and their protein levels. In conclusion, FHF1 promotes Leydig cell regeneration from stem cells while inhibiting the differentiation of preadipocyte/stem cells into adipocytes in EDS-treated testis.


Assuntos
Fatores de Crescimento de Fibroblastos/farmacologia , Células Intersticiais do Testículo/metabolismo , Regeneração , Células-Tronco/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Animais , Contagem de Células , Diferenciação Celular/efeitos dos fármacos , Enzima de Clivagem da Cadeia Lateral do Colesterol/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Antígeno Nuclear de Célula em Proliferação/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Regeneração/efeitos dos fármacos , Fatores de Transcrição SOX9/metabolismo , Células de Sertoli/efeitos dos fármacos , Células de Sertoli/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/efeitos dos fármacos , Testículo/metabolismo , Testosterona/sangue
19.
Steroids ; 149: 108423, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31175921

RESUMO

Dexmedetomidine (DEX), an imidazole compound, is an anesthetic drug used perioperatively. In the current study, we investigated the effects of DEX on androgen production in rat immature Leydig cells in vitro. Leydig cells isolated from pubertal Sprague Dawley rats were treated with various concentrations of DEX (0.015-1.5 µM) for 3 h and medium 5α-androstanediol and testosterone levels and the expression of Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, Hsd17b3, Srd5a1 and Akr1c14 in Leydig cells were determined. At 0.015-1.5 µM, DEX concentration-dependently inhibited androgen secretion and downregulated Cyp17a1 and Srd5a1 mRNA levels. DEX equally blocked the LH- and cAMP-stimulated secretion of androgens. Using the steroid substrates, 22R-hydroxycholesterol (for cytochrome P450 cholesterol side chain cleavage), pregnenolone (for 3ß-hydroxysteroid dehydrogenase 1), progesterone (for cytochrome P450 17α-hydroxylase/C17,C20-lyase), androstenedione (for 17ß-hydroxysteroid dehydrogenase 3), testosterone (for steroid 5α-reductase 1), and dihydrotestosterone (for 3α-hydroxysteroid dehydrogenase), it was demonstrated that DEX inhibited 22R-hydroxycholesterol, pregnenolone, progesterone, and testosterone-mediated 5α-androstanediol formation at 1.5 µM. Further study demonstrated that DEX also directly inhibited rat testis cholesterol side chain cleavage, 3ß-hydroxysteroid dehydrogenation, and 17α-hydroxylation at 1.5 µM. DEX induced ROS production and increased apoptosis rate in immature Leydig cells after 24-h treatment at ≥0.15 µM. In conclusion, DEX directly inhibits the activities of some steroidogenic enzymes and downregulates the expression of Cyp17a1 and Srd5a1, and increases ROS production, thus leading to lower production of androgens in immature Leydig cells.


Assuntos
Dexmedetomidina/farmacologia , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Esteroides/biossíntese , Androgênios/biossíntese , Animais , Apoptose/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo
20.
J Inorg Biochem ; 197: 110690, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31075721

RESUMO

A one-dimensional (1D) metal-organic framework (MOF) of [Cu(Cdcbp)(H2O)2·2H2O]n (1, H3CdcbpBr = 3-carboxyl-(3,5-dicarboxybenzyl)-pyridinium bromide) has been synthesized and characterized. MOF 1 features a cationic Cu2+ center, conjugated tricarboxylate ligand bearing positively charged pyridinium and uncoordinated carboxylate groups within its skeleton. These features enable MOF 1 to tightly adsorb thymine rich (T-rich) single-stranded DNA (ss-DNA) probe labeled with carboxyfluorescein (FAM) (denote as P-DNA) through π-stacking, electrostatic interactions and/or hydrogen bonding to give a hybrid complex (denote as P-DNA@1), and quenches its fluorescence via a photo-induced electron transfer (PET) process. The formed P-DNA@1 hybrid can thus function as a sensing platform for the detection of Hg2+, driven by the formation of hairpin-like double-stranded DNA (ds-DNA@Hg2+) with a T-Hg-T coordination motif, and subsequently dissociated into the solution due to its more rigid nature than ss-DNA, leading to the recovery of FAM fluorescence. In the presence of biothiols, including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), the strong coordination interaction between Hg2+ and the mercapto function serves to sequestrate the Hg2+ from the ds-DNA@Hg2+ duplex. The released ss-DNA, in turn, are re-adsorbed by MOF 1, leading to the formation of the initial P-DNA@1 state with fluorescence quenching. As such, P-DNA@1 detects Hg2+ and biothiols Cys/Hcy/GSH in sequence with detection limits of (2.3 ±â€¯0.8) nM and (29.6 ±â€¯0.1) nM/(19.8 ±â€¯0.5) nM/(10.2 ±â€¯0.1) nM. The sensing process is efficient and selective with instantaneous response time. The detection mechanism was further validated by circular dichroism (CD), and simulation studies using Molecular Operating Environment (MOE) package.


Assuntos
Técnicas Biossensoriais , Complexos de Coordenação/química , Sondas de DNA/química , Mercúrio/análise , Cádmio/química , Cobre/química , Compostos de Sulfidrila/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA