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1.
Proc Natl Acad Sci U S A ; 119(47): e2205988119, 2022 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-36375057

RESUMO

Discrimination is not only an objective fact but also a subjective judgment. While extensive research has studied discrimination as an objective fact, we study the judgment of discrimination and show that it is malleable while holding objective discrimination constant. We focus on a common situation in real life: the constituent groups in a candidate pool are unequal (e.g., fewer female candidates than male candidates for tech jobs), and observers (e.g., the public) see only one side of the decision outcome (e.g., only the hired applicants, not the rejected ones). Ten experiments reveal a framing effect: people judge the decision-maker (e.g., the tech firm) as more discriminatory against the minority in the candidate pool if people see the composition of the accepted candidates than if they see the composition of the rejected candidates, even though the information in the two frames is equivalent (i.e., knowing the information in one frame is sufficient to infer the information in the other). The framing effect occurs regardless of whether the decision-maker is objectively discriminatory, replicates across diverse samples (Americans, Asians, and Europeans) and types of discrimination (e.g., gender, race, political orientation), and has significant behavioral consequences. We theorize and show that the framing effect arises because, when judging discrimination, people overlook information that they could infer but is not explicitly given, and they expect equality in the composition of the constituent groups in their given frame. This research highlights the fallibility of judged discrimination and suggests interventions to reduce biases and increase accuracy.


Assuntos
Julgamento , Seleção de Pessoal , Humanos , Masculino , Feminino , Estados Unidos
2.
BMC Plant Biol ; 24(1): 117, 2024 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-38365588

RESUMO

BACKGROUND: In paddy fields, the noxious weed barnyard grass secretes 2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) to interfere with rice growth. Rice is unable to synthesize DIMBOA. Rice cultivars with high or low levels of allelopathy may respond differently to DIMBOA. RESULTS: In this study, we found that low concentrations of DIMBOA (≤ 0.06 mM) promoted seedling growth in allelopathic rice PI312777, while DIMBOA (≤ 0.08 mM) had no significant influence on the nonallelopathic rice Lemont. DIMBOA treatment caused changes in the expression of a large number of glutathione S-transferase (GST) proteins, which resulting in enrichment of the glutathione metabolic pathway. This pathway facilitates plant detoxification of heterologous substances. The basal levels of GST activity in Lemont were significantly higher than those in PI312777, while GST activity in PI312777 was slightly induced by increasing DIMBOA concentrations. Overexpression of GST genes (Os09g0367700 and Os01g0949800) in these two cultivars enhanced rice resistance to DIMBOA. CONCLUSIONS: Taken together, our results indicated that different rice accessions with different levels of allelopathy have variable tolerance to DIMBOA. Lemont had higher GST activity, which helped it tolerate DIMBOA, while PI312777 had lower GST activity that was more inducible. The enhancement of GST expression facilitates rice tolerance to DIMBOA toxins from barnyard grass root exudates.


Assuntos
Benzoxazinas , Echinochloa , Oryza , Oryza/metabolismo , Plantas Daninhas , Glutationa Transferase/genética , Glutationa Transferase/metabolismo
3.
Arch Toxicol ; 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38630283

RESUMO

Cannabidiol (CBD), one of the major components extracted from the plant Cannabis sativa L., has been used as a prescription drug to treat seizures in many countries. CBD-induced male reproductive toxicity has been reported in animal models; however, the underlying mechanisms remain unclear. We previously reported that CBD induced apoptosis in primary human Leydig cells, which constitute the primary steroidogenic cell population in the testicular interstitium. In this study, we investigated the effects of CBD and its metabolites on TM3 mouse Leydig cells. CBD, at concentrations below 30 µM, reduced cell viability, induced G1 cell cycle arrest, and inhibited DNA synthesis. CBD induced apoptosis after exposure to high concentrations (≥ 50 µM) for 24 h or a low concentration (20 µM) for 6 days. 7-Hydroxy-CBD and 7-carboxy-CBD, the main CBD metabolites of CBD, exhibited the similar toxic effects as CBD. In addition, we conducted a time-course mRNA-sequencing analysis in both primary human Leydig cells and TM3 mouse Leydig cells to understand and compare the mechanisms underlying CBD-induced cytotoxicity. mRNA-sequencing analysis of CBD-treated human and mouse Leydig cells over a 5-day time-course indicated similar responses in both cell types. Mitochondria and lysosome dysfunction, oxidative stress, and autophagy were the major enriched pathways in both cell types. Taken together, these findings demonstrate comparable toxic effects and underlying mechanisms in CBD-treated mouse and primary human Leydig cells.

4.
Planta Med ; 90(3): 219-242, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38198805

RESUMO

In September 2022, the 3rd International Workshop on pyrrolizidine alkaloids (PAs) and related phytotoxins was held on-line, entitled 'Toxins in botanical drugs and plant-derived food and feed - from science to regulation'. The workshop focused on new findings about the occurrence, exposure, toxicity, and risk assessment of PAs. In addition, new scientific results related to the risk assessment of alkenylbenzenes, a distinct class of herbal constituents, were presented. The presence of PAs and alkenylbenzenes in plant-derived food, feed, and herbal medicines has raised health concerns with respect to their acute and chronic toxicity but mainly related to the genotoxic and carcinogenic properties of several congeners. The compounds are natural constituents of a variety of plant families and species widely used in medicinal, food, and feed products. Their individual occurrence, levels, and toxic properties, together with the broad range of congeners present in nature, represent a striking challenge to modern toxicology. This review tries to provide an overview of the current knowledge on these compounds and indicates needs and perspectives for future research.


Assuntos
Plantas Medicinais , Alcaloides de Pirrolizidina , Alcaloides de Pirrolizidina/toxicidade
5.
J Phys Chem A ; 127(25): 5435-5445, 2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37319364

RESUMO

The concern of energy and the environment provides great inducement for fundamental research on the mechanisms of oxidation of char-bound nitrogen (char(N)). In the present study, based on the armchair(N) model, we investigated its reaction mechanism at an atomistic level and with a comprehensive study of the effect of the model surface. Several pathways are found by density functional theory (DFT) calculations for the oxidation of armchair(N). The main gaseous species released during the oxidation are NO, HCN, CO, and CO2. The evaluated optimal reaction pathways are selected to investigate the model-dependent reactivity. According to our calculations, the oxidation of the simplified top armchair(N) model (TM) will be much more competitive than that of the simplified edge armchair(N) model (EM). In the route giving NO, the decreased stability of the intermediates makes the reaction of TM more favorable. In the route giving HCN, the described reduced mechanism and the larger exothermicity and lower highest-energy transition state will be responsible for the priority. Further analysis of the kinetics gives the evidence for the competitiveness: the rate constants for most of the steps of the TM, such as HCN desorption, surface bond dissociation, ring closure and opening, and oxygen insertion and migration, are higher than that of the EM. Therefore, a conclusion can be drawn that the oxidation of the armchair(N) will mainly take place from the top surface rather than the edge surface. The results can be used to supplement present understanding of the oxidation of armchair structure, which is extremely crucial for the development of the kinetics model to better predict the NOx emissions during the air-staged combustion.

6.
Arch Toxicol ; 97(4): 1163-1175, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36847820

RESUMO

The in vitro micronucleus (MN) assay is a component of most test batteries used in assessing potential genotoxicity. Our previous study adapted metabolically competent HepaRG cells to the high-throughput (HT) flow-cytometry-based MN assay for genotoxicity assessment (Guo et al. in J Toxicol Environ Health A 83:702-717, 2020b, https://doi.org/10.1080/15287394.2020.1822972 ). We also demonstrated that, compared to HepaRG cells grown as two-dimensional (2D) cultures, 3D HepaRG spheroids have increased metabolic capacity and improved sensitivity in detecting DNA damage induced by genotoxicants using the comet assay (Seo et al. in ALTEX 39:583-604, 2022, https://doi.org/10.14573/altex.22011212022 ). In the present study, we have compared the performance of the HT flow-cytometry-based MN assay in HepaRG spheroids and 2D HepaRG cells by testing 34 compounds, including 19 genotoxicants or carcinogens and 15 compounds that show different genotoxic responses in vitro and in vivo. 2D HepaRG cells and spheroids were exposed to the test compounds for 24 h, followed by an additional 3- or 6-day incubation with human epidermal growth factor to stimulate cell division. The results demonstrated that HepaRG spheroids showed generally higher sensitivity in detecting several indirect-acting genotoxicants (require metabolic activation) compared to 2D cultures, with 7,12-dimethylbenzanthracene and N-nitrosodimethylamine inducing higher % MN formation along with having significantly lower benchmark dose values for MN induction in 3D spheroids. These data suggest that 3D HepaRG spheroids can be adapted to the HT flow-cytometry-based MN assay for genotoxicity testing. Our findings also indicate that integration of the MN and comet assays improved the sensitivity for detecting genotoxicants that require metabolic activation. These results suggest that HepaRG spheroids may contribute to New Approach Methodologies for genotoxicity assessment.


Assuntos
Dano ao DNA , Mutagênicos , Humanos , Testes para Micronúcleos/métodos , Mutagênicos/toxicidade , Ensaio Cometa/métodos , Testes de Mutagenicidade/métodos
7.
Arch Toxicol ; 97(12): 3227-3241, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37794255

RESUMO

Cannabidiol (CBD) is one of the most prevalent and abundant cannabinoids extracted from the plant Cannabis sativa. CBD has been reported to induce male reproductive toxicity in animal models. In this study, we examined the effects of CBD and its main metabolites, 7-carboxy-CBD and 7-hydroxy-CBD, on primary human Leydig cells, which play a crucial role in male reproductive health. Our results showed that CBD, at concentrations below the Bayesian benchmark dose (BMD)50, inhibited the growth of human Leydig cells by arresting the cell cycle at G1/S transition, disrupting cell cycle regulators, and decreasing DNA synthesis. Concentration-response transcriptomic profiling identified that apoptosis was one of the top biological processes significantly affected by treatment with CBD for 24 h. The occurrence of apoptosis was confirmed by increased activation of caspase-3/7 and an increased proportion of annexin V and propidium iodide (PI)-positive cells. Similar to CBD, both 7-carboxy-CBD and 7-hydroxy-CBD decreased cell viability and induced apoptosis after treatment for 24 h. 7-Hydroxy-CBD and 7-carboxy-CBD showed lower cytotoxicity than CBD, and 7-carboxy-CBD had the lowest cytotoxicity among the three compounds. Our findings revealed that CBD and its main metabolites can cause adverse effects on primary human Leydig cells.


Assuntos
Canabidiol , Canabinoides , Masculino , Animais , Humanos , Canabidiol/toxicidade , Teorema de Bayes , Células Intersticiais do Testículo , Apoptose
8.
Arch Toxicol ; 97(10): 2785-2798, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37486449

RESUMO

N-nitrosamine impurities have been increasingly detected in human drugs. This is a safety concern as many nitrosamines are mutagenic in bacteria and carcinogenic in rodent models. Typically, the mutagenic and carcinogenic activity of nitrosamines requires metabolic activation by cytochromes P450 enzymes (CYPs), which in many in vitro models are supplied exogenously using rodent liver homogenates. There are only limited data on the genotoxicity of nitrosamines in human cell systems. In this study, we used metabolically competent human HepaRG cells, whose metabolic capability is comparable to that of primary human hepatocytes, to evaluate the genotoxicity of eight nitrosamines [N-cyclopentyl-4-nitrosopiperazine (CPNP), N-nitrosodibutylamine (NDBA), N-nitrosodiethylamine (NDEA), N-nitrosodimethylamine (NDMA), N-nitrosodiisopropylamine (NDIPA), N-nitrosoethylisopropylamine (NEIPA), N-nitroso-N-methyl-4-aminobutyric acid (NMBA), and N-nitrosomethylphenylamine (NMPA)]. Under the conditions we used to culture HepaRG cells, three-dimensional (3D) spheroids possessed higher levels of CYP activity compared to 2D monolayer cells; thus the genotoxicity of the eight nitrosamines was investigated using 3D HepaRG spheroids in addition to more conventional 2D cultures. Genotoxicity was assessed as DNA damage using the high-throughput CometChip assay and as aneugenicity/clastogenicity in the flow-cytometry-based micronucleus (MN) assay. Following a 24-h treatment, all the nitrosamines induced DNA damage in 3D spheroids, while only three nitrosamines, NDBA, NDEA, and NDMA, produced positive responses in 2D HepaRG cells. In addition, these three nitrosamines also caused significant increases in MN frequency in both 2D and 3D HepaRG models, while NMBA and NMPA were positive only in the 3D HepaRG MN assay. Overall, our results indicate that HepaRG spheroids may provide a sensitive, human-based cell system for evaluating the genotoxicity of nitrosamines.


Assuntos
Nitrosaminas , Humanos , Nitrosaminas/toxicidade , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Carcinógenos/toxicidade , Dano ao DNA , Dimetilnitrosamina/toxicidade , Mutagênicos/toxicidade
9.
Regul Toxicol Pharmacol ; 141: 105410, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37210026

RESUMO

Propranolol is a widely used ß-blocker that can generate a nitrosated derivative, N-nitroso propranolol (NNP). NNP has been reported to be negative in the bacterial reverse mutation test (the Ames test) but genotoxic in other in vitro assays. In the current study, we systematically examined the in vitro mutagenicity and genotoxicity of NNP using several modifications of the Ames test known to affect the mutagenicity of nitrosamines, as well as a battery of genotoxicity tests using human cells. We found that NNP induced concentration-dependent mutations in the Ames test, both in two tester strains that detect base pair substitutions, TA1535 and TA100, as well as in the TA98 frameshift-detector strain. Although positive results were seen with rat liver S9, the hamster liver S9 fraction was more effective in bio-transforming NNP into a reactive mutagen. NNP also induced micronuclei and gene mutations in human lymphoblastoid TK6 cells in the presence of hamster liver S9. Using a panel of TK6 cell lines that each expresses a different human cytochrome P450 (CYP), CYP2C19 was identified as the most active enzyme in the bioactivation of NNP to a genotoxicant among those tested. NNP also induced concentration-dependent DNA strand breakage in metabolically competent 2-dimensional (2D) and 3D cultures of human HepaRG cells. This study indicates that NNP is genotoxic in a variety of bacterial and mammalian systems. Thus, NNP is a mutagenic and genotoxic nitrosamine and a potential human carcinogen.


Assuntos
Mutagênicos , Propranolol , Ratos , Animais , Cricetinae , Humanos , Mutagênicos/toxicidade , Propranolol/toxicidade , Mutação , Dano ao DNA , Mutagênese , Testes de Mutagenicidade/métodos , Mamíferos
10.
Molecules ; 28(7)2023 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-37049906

RESUMO

1,1,1-Trichloroethane (1,1,1-TCA) is a typical organochloride solvent in groundwater that poses threats to human health and the environment due to its carcinogenesis and bioaccumulation. In this study, a novel composite with nanoscale zero-valent iron (nZVI) supported by polycaprolac-tone (PCL)-modified biochar (nZVI@PBC) was synthesized via solution intercalation and liquid-phase reduction to address the 1,1,1-TCA pollution problem in groundwater. The synergy effect and improvement mechanism of 1,1,1-TCA removal from simulated groundwater in the presence of nZVI@PBC coupling with Shewanella putrefaciens CN32 were investigated. The results were as follows: (1) The composite surface was rough and porous, and PCL and nZVI were loaded uniformly onto the biochar surface as micro-particles and nanoparticles, respectively; (2) the optimal mass ratio of PCL, biochar, and nZVI was 1:7:2, and the optimal composite dosage was 1.0% (w/v); (3) under the optimal conditions, nZVI@PBC + CN32 exhibited excellent removal performance for 1,1,1-TCA, with a removal rate of 82.98% within 360 h, while the maximum removal rate was only 41.44% in the nZVI + CN32 treatment; (4) the abundance of CN32 and the concentration of adsorbed Fe(II) in the nZVI@PBC + CN32 treatment were significantly higher than that in control treatments, while the total organic carbon (TOC) concentration first increased and then decreased during the culture process; (5) the major improvement mechanisms include the nZVI-mediated chemical reductive dechlorination and the CN32-mediated microbial dissimilatory iron reduction. In conclusion, the nZVI@PBC composite coupling with CN32 can be a potential technique to apply for 1,1,1-TCA removal in groundwater.


Assuntos
Água Subterrânea , Shewanella putrefaciens , Poluentes Químicos da Água , Humanos , Ferro , Carvão Vegetal , Poluentes Químicos da Água/análise , Adsorção
11.
Arch Toxicol ; 96(11): 3077-3089, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35882637

RESUMO

Many nitrosamines are recognized as mutagens and potent rodent carcinogens. Over the past few years, nitrosamine impurities have been detected in various drugs leading to drug recalls. Although nitrosamines are included in a 'cohort of concern' because of their potential human health risks, most of this concern is based on rodent cancer and bacterial mutagenicity data, and there are little data on their genotoxicity in human-based systems. In this study, we employed human lymphoblastoid TK6 cells transduced with human cytochrome P450 (CYP) 2A6 to evaluate the genotoxicity of six nitrosamines that have been identified as impurities in drug products: N-nitrosodiethylamine (NDEA), N-nitrosoethylisopropylamine (NEIPA), N-nitroso-N-methyl-4-aminobutanoic acid (NMBA), N-nitrosomethylphenylamine (NMPA), N-nitrosodiisopropylamine (NDIPA), and N-nitrosodibutylamine (NDBA). Using flow cytometry-based assays, we found that 24-h treatment with NDEA, NEIPA, NMBA, and NMPA caused concentration-dependent increases in the phosphorylation of histone H2A.X (γH2A.X) in CYP2A6-expressing TK6 cells. Metabolism of these four nitrosamines by CYP2A6 also caused significant increases in micronucleus frequency as well as G2/M phase cell-cycle arrest. In addition, nuclear P53 activation was found in CYP2A6-expressing TK6 cells exposed to NDEA, NEIPA, and NMPA. Overall, the genotoxic potency of the six nitrosamine impurities in our test system was NMPA > NDEA ≈ NEIPA > NMBA > NDBA ≈ NDIPA. This study provides new information on the genotoxic potential of nitrosamines in human cells, complementing test results generated from traditional assays and partially addressing the issue of the relevance of nitrosamine genotoxicity for humans. The metabolically competent human cell system reported here may be a useful model for risk assessment of nitrosamine impurities found in drugs.


Assuntos
Histonas , Nitrosaminas , Amidas , Carcinógenos/metabolismo , Carcinógenos/toxicidade , Sistema Enzimático do Citocromo P-450/metabolismo , Dano ao DNA , Dietilnitrosamina/toxicidade , Humanos , Mutagênicos/toxicidade , Nitrosaminas/toxicidade , Propionatos , Proteína Supressora de Tumor p53 , Ácido gama-Aminobutírico
12.
J Appl Toxicol ; 42(9): 1491-1502, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35261072

RESUMO

Black cohosh extract (BCE) is one of the most popular botanical products for relieving menopausal symptoms. However, recent studies indicate that BCE is not only ineffective for menopausal therapy but also induces genotoxicity through an aneugenic mode of action (MoA). In this study, the cytotoxicity of five constituents of BCE was evaluated in human lymphoblastoid TK6 cells. Among the five constituents, actein (up to 50 µM) showed the highest cytotoxicity and was thus selected for further genotoxicity evaluations. Actein caused DNA damage proportionally to concentration as evidenced by the phosphorylation of the histone protein H2A.X (γH2A.X) and resulted in chromosomal damage as measured by the increased percentage of micronuclei (%MN) in cells. In addition, actein activated DNA damage response (DDR) pathway through induction of p-ATM, p-Chk1, and p-Chk2, which subsequently induced cell cycle changes and apoptosis. Moreover, both BCE and actein increased intracellular reactive oxygen species (ROS) production, decreased glutathione levels, and activated the mitogen-activated protein kinases (MAPK) signaling pathway. N-acetylcysteine, a ROS scavenger, attenuated BCE- and actein-induced ROS production, apoptosis, and DNA damage. These findings indicate that BCE- and actein-induced genotoxicity is mediated, at least partially, through oxidative stress. Taken together, our data show that actein is likely one of the major contributors to BCE-induced genotoxicity.


Assuntos
Cimicifuga , Cimicifuga/metabolismo , Cimicifuga/toxicidade , Dano ao DNA , Humanos , Extratos Vegetais , Espécies Reativas de Oxigênio/metabolismo , Saponinas , Triterpenos
13.
Sensors (Basel) ; 22(15)2022 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-35898064

RESUMO

INTRODUCTION: Obstructive sleep apnea (OSA) can cause serious health problems such as hypertension or cardiovascular disease. The manual detection of apnea is a time-consuming task, and automatic diagnosis is much more desirable. The contribution of this work is to detect OSA using a multi-error-reduction (MER) classification system with multi-domain features from bio-signals. METHODS: Time-domain, frequency-domain, and non-linear analysis features are extracted from oxygen saturation (SaO2), ECG, airflow, thoracic, and abdominal signals. To analyse the significance of each feature, we design a two-stage feature selection. Stage 1 is the statistical analysis stage, and Stage 2 is the final feature subset selection stage using machine learning methods. In Stage 1, two statistical analyses (the one-way analysis of variance (ANOVA) and the rank-sum test) provide a list of the significance level of each kind of feature. Then, in Stage 2, the support vector machine (SVM) algorithm is used to select a final feature subset based on the significance list. Next, an MER classification system is constructed, which applies a stacking with a structure that consists of base learners and an artificial neural network (ANN) meta-learner. RESULTS: The Sleep Heart Health Study (SHHS) database is used to provide bio-signals. A total of 66 features are extracted. In the experiment that involves a duration parameter, 19 features are selected as the final feature subset because they provide a better and more stable performance. The SVM model shows good performance (accuracy = 81.68%, sensitivity = 97.05%, and specificity = 66.54%). It is also found that classifiers have poor performance when they predict normal events in less than 60 s. In the next experiment stage, the time-window segmentation method with a length of 60s is used. After the above two-stage feature selection procedure, 48 features are selected as the final feature subset that give good performance (accuracy = 90.80%, sensitivity = 93.95%, and specificity = 83.82%). To conduct the classification, Gradient Boosting, CatBoost, Light GBM, and XGBoost are used as base learners, and the ANN is used as the meta-learner. The performance of this MER classification system has the accuracy of 94.66%, the sensitivity of 96.37%, and the specificity of 90.83%.


Assuntos
Síndromes da Apneia do Sono/diagnóstico , Algoritmos , Técnicas Biossensoriais/métodos , Humanos , Aprendizado de Máquina , Polissonografia/métodos , Sensibilidade e Especificidade , Sono/fisiologia , Apneia Obstrutiva do Sono/diagnóstico , Máquina de Vetores de Suporte
14.
Small ; 16(9): e1902262, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31322830

RESUMO

Combination chemotherapy with time-programmed administration of multiple drugs is a promising method for cancer treatment. However, realizing time-programmed release of combined drugs from a single carrier is still a great challenge in enhanced cancer therapy. Here, an implantable trilayer structured fiber device is developed to achieve time-programmed release of combined drugs for synergistic treatment of breast cancer. The fiber device is prepared by a modified microfluidic-electrospinning technique. The glycerol solution containing chemotherapy agent doxorubicin (Dox) forms the internal periodic cavities of the fiber, and poly(l-lactic acid) and poly(ε-caprolactone) containing the angiogenesis inhibitor apatinib (Apa) form the double walls of the fiber. Rapid release of Dox can be obtained by adjusting the wall thickness of the cavities, meanwhile sustained release of Apa is achieved through the slow degradation of the fiber matrix. After the fiber device is implanted subcutaneously near to the implanted solid tumor of mice, an excellent synergistic therapeutic effect is achieved through time-programmed release of the combined dual drugs. The fiber device provides a platform to sequentially co-deliver dual or multiple drugs for enhanced combined therapeutic efficacy.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica , Neoplasias da Mama , Preparações de Ação Retardada , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Doxorrubicina/administração & dosagem , Feminino , Humanos , Células MCF-7 , Camundongos , Piridinas/administração & dosagem
15.
Artigo em Inglês | MEDLINE | ID: mdl-31746269

RESUMO

Genotoxic compounds may be detoxified to non-genotoxic metabolites while many pro-carcinogens require metabolic activation to exert their genotoxicity in vivo. Standard genotoxicity assays were developed and utilized for risk assessment for over 40 years. Most of these assays are conducted in metabolically incompetent rodent or human cell lines. Deficient in normal metabolism and relying on exogenous metabolic activation systems, the current in vitro genotoxicity assays often have yielded high false positive rates, which trigger unnecessary and costly in vivo studies. Metabolically active cells such as hepatocytes have been recognized as a promising cell model in predicting genotoxicity of carcinogens in vivo. In recent years, significant advances in tissue culture and biological technologies provided new opportunities for using hepatocytes in genetic toxicology. This review encompasses published studies (both in vitro and in vivo) using hepatocytes for genotoxicity assessment. Findings from both standard and newly developed genotoxicity assays are summarized. Various liver cell models used for genotoxicity assessment are described, including the potential application of advanced liver cell models such as 3D spheroids, organoids, and engineered hepatocytes. An integrated strategy, that includes the use of human-based cells with enhanced biological relevance and throughput, and applying the quantitative analysis of data, may provide an approach for future genotoxicity risk assessment.


Assuntos
Carcinógenos/toxicidade , Fígado/citologia , Fígado/efeitos dos fármacos , Testes de Mutagenicidade/métodos , Mutagênicos/toxicidade , Animais , Células Cultivadas , Hepatócitos , Humanos , Organoides , Medição de Risco , Esferoides Celulares
16.
Arch Toxicol ; 94(8): 2873-2884, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32435917

RESUMO

Dieldrin has been shown to induce liver tumors selectively in mice. Although the exact mechanism is not fully understood, previous studies from our laboratory and others have shown that dieldrin induced liver tumors in mice through a non-genotoxic mechanism acting on tumor promotion stage. Two studies were performed to examine the role of nuclear receptor activation as a possible mode of action (MOA) for dieldrin-induced mouse liver tumors. In the initial study, male C57BL/6 mice (6- to 8-week old) were treated with dieldrin in diet (10 ppm) for 7, 14, and 28 days. Phenobarbital (PB), beta-naphthoflavone (BNF) and Di (2-ethylhexyl) phthalate (DEHP) were included as positive controls in this study for evaluating the involvement of CAR (constitutive androstane receptor), AhR (aryl hydrocarbon receptor) or PPARα (peroxisome proliferator activated receptor alpha) in the MOA of dieldrin hepatocarcinogenesis. A significant increase in hepatocyte DNA synthesis (BrdU incorporation) was seen in treated mice compared with the untreated controls. Analysis of the expression of the nuclear receptor responsive genes revealed that dieldrin induced a significant increase in the expression of genes specific to CAR activation (Cyp2b10, up to 400- to 2700-fold) and PXR activation (Cyp3a11, up to 5- to 11-fold) over untreated controls. The AhR target genes Cyp1a1 and Cyp1a2 were also slightly induced (2.0- to 3.7-fold and 1.7- to 2.8-fold, respectively). PPARα activation was not seen in the liver following dieldrin treatment. In addition, consistent with previous studies in our lab, treatment with dieldrin produced significant elevation in the hepatic oxidative stress. In a subsequent study using CAR, PXR, and CAR/PXR knockout mice, we confirmed that the dieldrin-induced liver effects in mouse were only mediated by the activation of CAR receptor. Based on these findings, we propose that dieldrin induced liver tumors in mice through a nuclear receptor CAR-mediated mode of action. The previously observed oxidative stress/damage may be an associated or modifying factor in the process of dieldrin-induced liver tumor formation subsequent to the CAR activation.


Assuntos
Transformação Celular Neoplásica/induzido quimicamente , Dieldrin/toxicidade , Inseticidas/toxicidade , Neoplasias Hepáticas/induzido quimicamente , Fígado/efeitos dos fármacos , Receptores Citoplasmáticos e Nucleares/agonistas , Animais , Hidrocarboneto de Aril Hidroxilases/biossíntese , Hidrocarboneto de Aril Hidroxilases/genética , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Receptor Constitutivo de Androstano , Família 2 do Citocromo P450/biossíntese , Família 2 do Citocromo P450/genética , Replicação do DNA/efeitos dos fármacos , Indução Enzimática , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estresse Oxidativo/efeitos dos fármacos , PPAR alfa/genética , PPAR alfa/metabolismo , Receptor de Pregnano X/genética , Receptor de Pregnano X/metabolismo , Receptores Citoplasmáticos e Nucleares/metabolismo , Transdução de Sinais , Esteroide Hidroxilases/biossíntese , Esteroide Hidroxilases/genética
17.
Arch Toxicol ; 94(7): 2401-2411, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32372212

RESUMO

Sertraline, an antidepressant, is commonly used to manage mental health symptoms related to depression, anxiety disorders, and obsessive-compulsive disorder. The use of sertraline has been associated with rare but severe hepatotoxicity. Previous research demonstrated that mitochondrial dysfunction, apoptosis, and endoplasmic reticulum stress were involved in sertraline-associated cytotoxicity. In this study, we reported that after a 24-h treatment in HepG2 cells, sertraline caused cytotoxicity, suppressed topoisomerase I and IIα, and damaged DNA in a concentration-dependent manner. We also investigated the role of cytochrome P450 (CYP)-mediated metabolism in sertraline-induced toxicity using our previously established HepG2 cell lines individually expressing 14 CYPs (1A1, 1A2, 1B1, 2A6, 2B6, 2C8, 2C9, 2C18, 2C19, 2D6, 2E1, 3A4, 3A5, and 3A7). We demonstrated that CYP2D6, 2C19, 2B6, and 2C9 metabolize sertraline, and sertraline-induced cytotoxicity was significantly decreased in the cells expressing these CYPs. Western blot analysis demonstrated that the induction of É£H2A.X (a hallmark of DNA damage) and topoisomerase inhibition were partially reversed in CYP2D6-, 2C19-, 2B6-, and 2C9-overexpressing HepG2 cells. These data indicate that DNA damage and topoisomerase inhibition are involved in sertraline-induced cytotoxicity and that CYPs-mediated metabolism plays a role in decreasing the toxicity of sertraline.


Assuntos
Antidepressivos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Sistema Enzimático do Citocromo P-450/metabolismo , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Inibidores Seletivos de Recaptação de Serotonina/toxicidade , Sertralina/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Dano ao DNA , DNA Topoisomerases Tipo I/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Células Hep G2 , Hepatócitos/enzimologia , Hepatócitos/patologia , Humanos , Isoenzimas , Fígado/enzimologia , Fígado/patologia , Desintoxicação Metabólica Fase I , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo
18.
J Adv Nurs ; 76(11): 3155-3163, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32901984

RESUMO

AIM: To evaluate the effects of internet-based support program for primiparous women in terms of improving the levels of maternal self-efficacy, social support, and satisfaction; and reducing their postpartum depression symptoms. DESIGN: A single-blinded, multicentre, randomized, controlled, parallel-group pre-test and repeated post-test design. METHODS: Based on the self-efficacy theory and the social exchange theory, the internet-based support program has five modules: (a) learning forum of parenting knowledge and skills; (b) communication forum; (c) ask-the-expert forum; (d) baby home forum; and (e) reminder forum. Primiparous women will be recruited in the obstetric wards of two university-affiliated hospitals in China. The participants (N = 258) will be randomly allocated to the intervention group that receive routine care and access to the internet-based support program and the control group that receive routine care during the 3 months postpartum. Maternal self-efficacy, social support, and postpartum depression symptoms will be measured at baseline, immediately after the intervention (post-test 1) and 3 months after the intervention (post-test 2). The study was funded in January 2018 and was ethically approved in May 2020. DISCUSSION: If the internet-based support program has positive outcomes, it will contribute to the scientific and practical knowledge of nursing interventions to support primiparous women on parenting; and could become the routine health care for health professionals to enhance parenting ability and mental well-being of new mothers. IMPACT: As the first RCT study on parenting outcomes using a rigorous research design and a theoretical framework in China, this research will contribute to evidence on the effectiveness of using internet platform to support women after childbirth. The results could help to advance research about the use of internet-based intervention methods to improve women's maternal self-efficacy, social support, satisfaction, and to alleviate depression symptoms. Chinese Clinical Trial Registry: ChiCTR2000033154.


Assuntos
Depressão Pós-Parto , Poder Familiar , China , Depressão Pós-Parto/prevenção & controle , Feminino , Humanos , Lactente , Internet , Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto , Autoeficácia
19.
Sensors (Basel) ; 20(15)2020 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-32756353

RESUMO

People with sleep apnea (SA) are at increased risk of having stroke and cardiovascular diseases. Polysomnography (PSG) is used to detect SA. This paper conducts feature selection from PSG signals and uses a support vector machine (SVM) to detect SA. To analyze SA, the Physionet Apnea Database was used to obtain various features. Electrocardiography (ECG), oxygen saturation (SaO2), airflow, abdominal, and thoracic signals were used to provide various frequency-, time-domain and non-linear features (n = 87). To analyse the significance of these features, firstly, two evaluation measures, the rank-sum method and the analysis of variance (ANOVA) were used to evaluate the significance of the features. These features were then classified according to their significance. Finally, different class feature sets were presented as inputs for an SVM classifier to detect the onset of SA. The hill-climbing feature selection algorithm and the k-fold cross-validation method were applied to evaluate each classification performance. Through the experiments, we discovered that the best feature set (including the top-five significant features) obtained the best classification performance. Furthermore, we plotted receiver operating characteristic (ROC) curves to examine the performance of the SVM, and the results showed the SVM with Linear kernel (regularization parameter = 1) outperformed other classifiers (area under curve = 95.23%, sensitivity = 94.29%, specificity = 96.17%). The results confirm that feature subsets based on multiple bio-signals have the potential to identify patients with SA. The use of a smaller subset avoids dimensionality problems and reduces the computational load.


Assuntos
Síndromes da Apneia do Sono , Algoritmos , Eletrocardiografia , Humanos , Polissonografia , Síndromes da Apneia do Sono/diagnóstico , Máquina de Vetores de Suporte
20.
Small ; 15(8): e1804397, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30677228

RESUMO

Multiple drug resistance (MDR) of cancer cells is a major cause of chemotherapy failure. It is currently a great challenge to develop a direct and effective strategy for continuously inhibiting the P-glycoprotein (P-gp) drug pump of MDR tumor cells, thus enhancing the intracellular concentration of the therapeutic agent for effectively killing MDR tumor cells. Here, a new implantable hierarchical-structured ultrafine fiber device is developed via a microfluidic-electrospinning technology for localized codelivery of doxorubicin (DOX) and apatinib (AP). An extremely high encapsulation efficiency of ≈99% for the dual drugs is achieved through this strategy. The release of the loaded dual drugs can be controlled in a programmable release model with a rapid release of the micelles, while AP is slowly released. The sustained release of AP can continuously inhibit the P-gp drug pump of MDR tumor cells, increasing the intracellular DOX accumulation. The in vivo DOX biodistribution displays that the DOX accumulation in the tumor tissues achieves 17.82% after implanting the fiber device for 72 h, which is 6.36-fold higher than that of the intravenously injected DOX. Importantly, the fiber device shows an excellent antitumor effect on MDR tumor-bearing mice with low systemic toxicity.


Assuntos
Doxorrubicina/administração & dosagem , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/química , Piridinas/administração & dosagem , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Animais , Linhagem Celular Tumoral , Doxorrubicina/uso terapêutico , Resistência a Múltiplos Medicamentos/genética , Resistencia a Medicamentos Antineoplásicos , Células Endoteliais/metabolismo , Feminino , Humanos , Células MCF-7 , Camundongos , Micelas , Piridinas/uso terapêutico
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