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Extracellular vesicles (EVs), including exosomes, microvesicles, and other lipid vesicles derived from cells, play a pivotal role in intercellular communication by transferring information between cells. EVs secreted by progenitor and stem cells have been associated with the therapeutic effects observed in cell-based therapies, and they also contribute to tissue regeneration following injury, such as in orthopaedic surgery cases. This review explores the involvement of EVs in nerve regeneration, their potential as drug carriers, and their significance in stem cell research and cell-free therapies. It underscores the importance of bioengineers comprehending and manipulating EV activity to optimize the efficacy of tissue engineering and regenerative therapies.
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Vesículas Extracelulares , Regeneração Nervosa , Células-Tronco , Humanos , Vesículas Extracelulares/metabolismo , Animais , Células-Tronco/metabolismo , Células-Tronco/citologia , Engenharia Tecidual/métodos , Exossomos/metabolismo , Medicina Regenerativa/métodosRESUMO
Increases in botanical use, encompassing herbal medicines and dietary supplements, have underlined a critical need for an advancement in safety assessment methodologies. However, botanicals present unique challenges for safety assessment due to their complex and variable composition arising from diverse growing conditions, processing methods, and plant varieties. Historically, botanicals have been largely evaluated based on their history of use information, based primarily on traditional use or dietary history. However, this presumption lacks comprehensive toxicological evaluation, demanding innovative and consistent assessment strategies. To address these challenges, the Botanical Safety Consortium (BSC) was formed as an international, cross-sector forum of experts to identify fit-for purpose assays that can be used to evaluate botanical safety. This global effort aims to assess botanical safety assessment methodologies, merging traditional knowledge with modern in vitro and in silico assays. The ultimate goal is to champion the development of toxicity tools for botanicals. This manuscript highlights: 1) BSC's strategy for botanical selection, sourcing, and preparation of extracts to be used in in vitro assays, and 2) the approach utilized to characterize botanical extracts, using green tea and Asian ginseng as examples, to build confidence for use in biological assays.
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Plantas Medicinais , Suplementos Nutricionais , CháRESUMO
BACKGROUND AND PURPOSE: Family-centered care (FCC) is a crucial and dynamic philosophy within 21st-century pediatric nursing, offering numerous benefits for both children and their families. It is essential for pediatric nurses to be well-versed in the FCC approach and related practices. The aim of this study is to determine the effect of nurse training on nurses' attitudes towards FCC and on nurses' clinical practices related to FCC. METHODS: This study utilized a pretest-posttest, single-blind (for nurses and parents), and prospective design. The sample consisted of nurses (n = 41) employed at a university hospital's pediatric clinics and parents (n = 256) with infants or children admitted to these clinics. Data collection involved the Nurse Information Form, Parent and Child Information Form, Family-Centered Care Scale (FCCS), and Family-Centered Care Attitude Scale (FCCAS). RESULTS: A significant difference was observed between nurses' pre- and post-training FCCAS median scores (p < 0.05). However, no statistically significant difference was detected between the median FCCS scores of parents whose children were cared for by nurses before and after the training (p > 0.05). CONCLUSION: Following the FCC training provided to pediatric nurses, their attitudes towards the necessity and importance of FCC significantly improved compared to the pre-training period. However, no significant difference was found in the perceived FCC practices of parents whose children received inpatient treatment during the pre-and post-training periods. IMPLICATIONS TO PRACTICE: Training is important in improving pediatric nurses' attitudes towards FCC. Planned training on FCC should be provided for nurses. Difficulties in pediatric nurses' FCC practices should be identified. In addition, FCC practices should be implemented as a policy in hospitals and pediatric clinics and nurses should be supported to ensure the implementation of FCC practices.
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Atitude do Pessoal de Saúde , Enfermeiros Pediátricos , Criança , Humanos , Método Simples-Cego , Pais , Inquéritos e Questionários , Assistência Centrada no Paciente , PercepçãoRESUMO
N-butylbenzenesulfonamide (NBBS) is a high-production volume plasticizer that is an emerging contaminant of concern for environmental and human health. To understand the risks and health effects of exposure to NBBS, studies were conducted in adult-exposed mice and developmentally exposed rats to evaluate the potential for NBBS to modulate the immune system. Beginning between 8 and 9 weeks of age, dosed feed containing NBBS at concentrations of 0, 313, 625, 1250, 2500, and 5000 ppm was continuously provided to B6C3F1/N female mice for 28 days. Dosed feed was also continuously provided to time-mated Harlan Sprague Dawley (Sprague Dawley SD) rats at concentrations of 0-, 250-, 500-, and 1000-ppm NBBS from gestation day 6 to postnatal day 28 and in F1 rats until 11-14 weeks of age. Functional assessments of innate, humoral, and cell-mediated immunity were conducted in adult female mice and F1 rats following exposure to NBBS. In female mice, NBBS treatment suppressed the antibody-forming cell (AFC) response to SRBC with small increases in T-cell responses and natural killer (NK)-cell activity. In developmentally exposed rats, NBBS treatment-related immune effects were sex dependent. A positive trend in NK-cell activity occurred in male F1 rats while a negative trend occurred in female F1 rats. The AFC response to SRBC was decreased in female F1 rats but not in male F1 rats. These data provide evidence that oral exposure to NBBS has the potential to produce immunomodulatory effects on both innate and adaptive immune responses, and these effects appear to have some dependence on species, sex, and period of exposure (developmental vs adult).
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Imunidade , Sulfonamidas , Humanos , Ratos , Camundongos , Animais , Masculino , Feminino , Ratos Sprague-Dawley , Sulfonamidas/toxicidade , Camundongos EndogâmicosRESUMO
OBJECTIVE: This descriptive cross-sectional study aimed to determine the effect of pregnancy symptoms on the sexual quality of life. METHODS: This study included 150 pregnant women who visited the obstetrics and gynecology outpatient clinic of the hospital between October 1, 2019, and April 1, 2020, and met the inclusion criteria. Data were collected using the Personal and Obstetric Information form, Sexual Quality of Life-Female scale, and Pregnancy Symptom Inventory. RESULTS: The mean age of the participants was 27.7±5.2 years. As per the collected data, 39.3% of the participants had university- or higher-level education and 21.3% had an income-generating job. A weak negative correlation was found between the scores of Sexual Quality of Life-Female and frequency of pregnancy symptoms and limitation in daily activities (p=0.016 and p=0.020, respectively), whereas a strong positive correlation was found between frequency of pregnancy symptoms and limitation in daily activities. Regression analysis showed that as Sexual Quality of Life-Female scores decreased, frequency of pregnancy symptoms and limitation in daily activities scores increased (p<0.001). CONCLUSION: Our study showed that, as the frequency of symptoms experienced during pregnancy and their impact on daily life increase, the sexual quality of life decreases. We recommend providing education and counseling services to women and their partners about pregnancy symptoms and its impact on sexual life during pregnancy and implementing effective measures to eliminate the negative effects of these symptoms on the sexual quality of life.
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Qualidade de Vida , Comportamento Sexual , Feminino , Gravidez , Humanos , Adulto Jovem , Adulto , Estudos Transversais , Comportamento Sexual/psicologiaRESUMO
Cookstove emissions are a significant source of indoor air pollution in developing countries and rural communities world-wide. Considering that many research sites for evaluating cookstove emissions and interventions are remote and require potentially lengthy periods of particulate matter (PM) filter sample storage in sub-optimal conditions (e.g., lack of cold storage), an important question is whether samples collected in the field are stable over time. To investigate this, red oak was burned in a natural-draft stove, and fine PM (PM2.5) was collected on polytetrafluoroethylene filters. Filters were stored at either ambient temperature or more optimal conditions (-20°C or -80°C) for up to 3 months and extracted. The effects of storage temperature and length on stability were evaluated for measurements of extractable organic matter (EOM), PM2.5, and polycyclic aromatic compound (PAC) levels in the filter extracts. A parallel, controlled laboratory condition was also evaluated to further explore sources of variability. In general, PM2.5 and EOM in both simulated field and laboratory samples were similar regardless of the storage condition or duration. The extracts were also analyzed by gas chromatography to quantify 22 PACs and determine similarities and/or differences between the conditions. PAC levels were a more sensitive stability measure in differentiating between storage conditions. The findings suggest that measurements are relatively consistent across storage duration/temperatures for filter samples with relatively low EOM levels. This study aims to inform protocols and filter storage procedures for exposure and intervention research conducted in low- and middle-income countries where studies may be budget- and infrastructure-limited.
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Glyphosate, the most heavily used herbicide world-wide, is applied to plants in complex formulations that promote absorption. The National Toxicology Program reported in 1992 that glyphosate, administered to rats and mice at doses up to 50,000 ppm in feed for 13 weeks, showed little evidence of toxicity, and no induction of micronuclei was observed in the mice in this study. Subsequently, mechanistic studies of glyphosate and glyphosate-based formulations (GBFs) that have focused on DNA damage and oxidative stress suggest that glyphosate may have genotoxic potential. However, few of these studies directly compared glyphosate to GBFs, or effects among GBFs. To address these data gaps, we tested glyphosate, glyphosate isopropylamine (IPA), and (aminomethyl)phosphonic acid (AMPA, a microbial metabolite of glyphosate), 9 high-use agricultural GBFs, 4 residential-use GBFs, and additional herbicides (metolachlor, mesotrione, and diquat dibromide) present in some of the GBFs in bacterial mutagenicity tests, and in human TK6 cells using a micronucleus assay and a multiplexed DNA damage assay. Our results showed no genotoxicity or notable cytotoxicity for glyphosate or AMPA at concentrations up to 10 mM, while all GBFs and herbicides other than glyphosate were cytotoxic, and some showed genotoxic activity. An in vitro to in vivo extrapolation of results for glyphosate suggests that it is of low toxicological concern for humans. In conclusion, these results demonstrate a lack of genotoxicity for glyphosate, consistent with observations in the NTP in vivo study, and suggest that toxicity associated with GBFs may be related to other components of these formulations.
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Herbicidas , Humanos , Camundongos , Animais , Ratos , Herbicidas/toxicidade , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol Propiônico , Dano ao DNA , GlifosatoRESUMO
SUMMARY OBJECTIVE: This descriptive cross-sectional study aimed to determine the effect of pregnancy symptoms on the sexual quality of life. METHODS: This study included 150 pregnant women who visited the obstetrics and gynecology outpatient clinic of the hospital between October 1, 2019, and April 1, 2020, and met the inclusion criteria. Data were collected using the Personal and Obstetric Information form, Sexual Quality of Life-Female scale, and Pregnancy Symptom Inventory. RESULTS: The mean age of the participants was 27.7±5.2 years. As per the collected data, 39.3% of the participants had university- or higher-level education and 21.3% had an income-generating job. A weak negative correlation was found between the scores of Sexual Quality of Life-Female and frequency of pregnancy symptoms and limitation in daily activities (p=0.016 and p=0.020, respectively), whereas a strong positive correlation was found between frequency of pregnancy symptoms and limitation in daily activities. Regression analysis showed that as Sexual Quality of Life-Female scores decreased, frequency of pregnancy symptoms and limitation in daily activities scores increased (p<0.001). CONCLUSION: Our study showed that, as the frequency of symptoms experienced during pregnancy and their impact on daily life increase, the sexual quality of life decreases. We recommend providing education and counseling services to women and their partners about pregnancy symptoms and its impact on sexual life during pregnancy and implementing effective measures to eliminate the negative effects of these symptoms on the sexual quality of life.
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Black cohosh (BC; Actaea racemosa L.), a top-selling botanical dietary supplement, is marketed to women primarily to ameliorate a variety of gynecological symptoms. Due to widespread usage, limited safety information, and sporadic reports of hepatotoxicity, the Division of the National Toxicology Program (DNTP) initially evaluated BC extract in female rats and mice. Following administration of up to 1000 mg/kg/day BC extract by gavage for 90 days, dose-related increases in micronucleated peripheral blood erythrocytes were observed, along with a nonregenerative macrocytic anemia resembling megaloblastic anemia in humans. Because both micronuclei and megaloblastic anemia may signal disruption of folate metabolism, and inadequate folate levels in early pregnancy can adversely affect neurodevelopment, the DNTP conducted a pilot cross-sectional study comparing erythrocyte micronucleus frequencies, folate and B12 levels, and a variety of hematological and clinical chemistry parameters between women who used BC and BC-naïve women. Twenty-three women were enrolled in the BC-exposed group and 28 in the BC-naïve group. Use of any brand of BC-only supplement for at least 3 months was required for inclusion in the BC-exposed group. Supplements were analyzed for chemical composition to allow cross-product comparisons. All participants were healthy, with no known exposures (e.g., x-rays, certain medications) that could influence study endpoints. Findings revealed no increased micronucleus frequencies and no hematological abnormalities in women who used BC supplements. Although reassuring, a larger, prospective study with fewer confounders (e.g., BC product diversity and duration of use) providing greater power to detect subtle effects would increase confidence in these findings.
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Anemia Megaloblástica , Cimicifuga , Gravidez , Humanos , Feminino , Ratos , Camundongos , Animais , Estudos Transversais , Cimicifuga/efeitos adversos , Estudos Prospectivos , Suplementos Nutricionais/toxicidade , Ácido FólicoRESUMO
Principal component analysis (PCA) as a machine-learning technique could serve in disease diagnosis and prognosis by evaluating the dynamic morphological features of exosomes via Cryo-TEM-imaging. This hypothesis was investigated after the crude isolation of similarly featured exosomes derived from the extracellular vehicles (EVs) of immature dendritic cells (IDCs) JAWSII. It is possible to identify functional molecular groups by FTIR, but the unique physical and morphological characteristics of exosomes can only be revealed by specialized imaging techniques such as cryo-TEM. On the other hand, PCA has the ability to examine the morphological features of each of these IDC-derived exosomes by considering software parameters such as various membrane projections and differences in Gaussians, Hessian, hue, and class to assess the 3D orientation, shape, size, and brightness of the isolated IDC-derived exosome structures. In addition, Brownian motions from nanoparticle tracking analysis of EV IDC-derived exosomes were also compared with EV IDC-derived exosome images collected by scanning electron microscopy and confocal microscopy. Sodium-Dodecyl-Sulphate-Polyacrylamide-Gel-Electrophoresis (SDS-PAGE) was performed to separate the protein content of the crude isolates showing that no considerable protein contamination occurred during the crude isolation technique of IDC-derived-exosomes. This is an important finding because no additional purification of these exosomes is required, making PCA analysis both valuable and novel.
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Phenolic benzotriazoles are used as UV stabilizers in consumer products and have been detected in the environment suggesting potential human exposure. Phenolic benzotriazoles were nominated to the Division of National Toxicology Program for testing based on their potential widespread human exposure and lack of adequate toxicity data. Nine chemicals were selected for toxicological evaluation, representing unsubstituted (2-(2H-benzotriazole-2-yl)phenol, (P-BZT)), monosubstituted (drometrizole; 2-(2H-benzotriazol-2-yl)-4-tert-butylphenol (tBu-BZT); octrizole), disubstituted (2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (diMeEtPh-BZT), 2-(2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylpropyl)phenol (ditPe-BZT); 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxybenzenepropanoic acid, octylester (tBuPrOcEst-BZT) and halogenated trisubstituted (bumetrizole; 2-(5-chloro-2H-benzotriazol-2-yl)-4,6-bis(1,1-dimethylethyl)phenol (ditBuCl-BZT)) compounds. Different extraction methods were utilized and methods were developed to analyze phenolic benzotriazoles by quantitating free (unconjugated parent) and total (free and conjugated parent) analyte levels in plasma of rats to aid in interpretation of toxicity data, understanding of absorption, distribution, metabolism, and excretion differences. The calibration standard range was 1-500 ng/mL for free analytes and 1-1000 ng/mL for total analytes. The methods were linear (r2 ≥ 0.99). The accuracy was determined as relative error (RE) and ranged from -18.2 to +17.8, and precision was determined as relative standard deviation (RSD) and ranged from 0.0 to 20.1% for both free and total plasma calibration standards, respectively. The limit of quantitation was ≤ 5.0 and 10.0 ng/mL and limit of detection was ≤ 1.2 and 2.0 ng/mL, for free and total analytes, respectively. These data demonstrate that the methods are suitable for quantitation of free and total analytes in rat plasma.
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Garcinia cambogia extract (GCE) is a popular botanical supplement used in weight loss products. Hydroxycitric acid (HCA) is the principal component in GCE. Due to lack of adequate toxicity data to assess the safe use of GCE, the National Toxicology Program is testing GCE in Hsd:Sprague Dawley® SD® rats following perinatal exposure and in adult B6C3F1/N mice. We report a validated method utilizing sample clean up with ultrafiltration followed by liquid chromatography-tandem mass spectrometry analysis to quantify HCA in rat plasma over the concentration range of 20 to 800 ng/mL. The method was linear (r2 ≥ 0.99) with the limits of quantitation (LOQ) and detection (LOD) of 20.0 and 3.9 ng/mL plasma, respectively. The accuracy (determined as relative error, RE) and precision (determined as relative standard deviation, RSD) using Quality Control standards analyzed over multiple days were ≤ ± 7.5% and ≤ 9.5%, respectively. The method can be applied to quantify HCA in study matrices (RE ≤ ± 23.0%; RSD ≤ 6.0) except gestational day (GD)18 fetus. The method was partially validated in GD18 fetal homogenate over the concentration range 60-3000 ng/g (r2 ≥ 0.99, RE ≤ ± 11.9%, and RSD ≤ 5.5%; LOQ 60.0 ng/g; LOD 7.77 ng/g). The standards as high as 20,000 ng/mL (plasma) and 502,000 ng/g (fetus) can successfully be quantified after diluting into the validated range (RE ≤ ± 2.6%; RSD ≤ 5.2%). These data demonstrate that the method is suitable to quantify HCA in rodent matrices and can be adapted to other biological matrices.
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Black cohosh (Actaea racemosa L.) is a botanical supplement marketed to women of all ages. Due to paucity of data to assess the safe use, the National Toxicology Program (NTP) is evaluating the toxicity of black cohosh. The use of an authentic, quality material is imperative to generate robust data. Because botanical materials are complex mixtures with variable composition, the selection of a material is challenging. We describe selection and phytochemical characterization of an unformulated black cohosh root extract (i.e., an extract that serves as source material for a formulated product) to be used in the NTP assessments. A material was selected using a combination of non-targeted and targeted chemical analyses, including confirmation of authenticity, absence of contaminants and adulterants, and similarity to a popular black cohosh product used by consumers. Thirty-nine constituents covering three major classes, triterpene glycosides, phenolic acids, and alkaloids were identified. Among constituents quantified, triterpene glycosides made up approximately 4.7% (w/w) with total constituents quantified making up 5.8% (w/w) of the extract. Non-targeted chemical analysis followed by chemometric analysis of various materials sold as black cohosh, and reference materials for black cohosh and other Actaea species further confirmed the suitability of the selected extract for use.
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Cimicifuga/química , Extratos Vegetais/química , Alcaloides/química , Cromatografia Líquida de Alta Pressão , Contaminação de Medicamentos , Glicosídeos/química , Hidroxibenzoatos/química , Espectrometria de Massas , Triterpenos/químicaRESUMO
OBJECTIVE: Ethyltoluenes are isolated during crude oil refinement for use in gasoline and commercial products and are ubiquitous in the environment. However, minimal toxicity data are available. Previously, we identified 2-ethyltoluene (2-ET) as the most potent isomer via nose-only inhalation exposure in rodents. Here, we expanded the hazard characterization of 2-ET in two rodent models using whole-body inhalation exposure and evaluated the role of prenatal exposure. METHODS: Time-mated Hsd:Sprague Dawley® SD® rats were exposed to 0, 150, 300, 600, 900, or 1200 ppm 2-ET via inhalation starting on gestation day 6 until parturition. Rat offspring (n = 8/exposure/sex) were exposed to the same concentrations as the respective dams for 2 weeks after weaning. Adult male and female B6C3F1/N mice (n = 5/exposure/sex) were exposed to the same concentrations for 2 weeks. RESULTS AND DISCUSSION: Exposure to ≥600 ppm 2-ET produced acute toxicity in rats and mice characterized by large decreases in survival, body weight, adverse clinical observations, and diffuse nasal olfactory epithelium degeneration (rats) or necrosis (mice). Due to the early removal of groups ≥600 ppm, most endpoint evaluations focused on lower exposure groups. In 150 and 300 ppm exposure groups, reproductive performance and littering were not significantly changed and body weights in exposed rats and mice were 9-18% lower than controls. Atrophy of the olfactory epithelium and nerves was observed in all animals exposed to 150 and 300 ppm. These lesions were more severe in mice than in rats. CONCLUSION: Nasal lesions were observed in all animals after whole-body exposure up to 600 ppm 2-ET for 2 weeks. Future studies should focus on 2-ET metabolism and distribution to better understand species differences and refine hazard characterization of this understudied environmental contaminant.
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Exposição por Inalação , Administração por Inalação , Animais , Feminino , Exposição por Inalação/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos , Gravidez , Ratos , Ratos Endogâmicos F344 , Ratos Sprague-DawleyRESUMO
Phenolic benzotriazoles are ultraviolet-light absorbers used in a variety of industrial and consumer applications. We investigated the toxicokinetic behaviour of 9 compounds, covering unsubstituted, monosubstituted, disubstituted, and trisubstituted compounds, following a single gavage (30 and 300 mg/kg) and intravenous (IV) (2.25 mg/kg) administration in male rats.Following IV administration, no distinct pattern in plasma elimination was observed for the compounds with half-lives ranging from 15.4-84.8 h. Systemic exposure parameters, maximum concentration (Cmax) and area under the concentration time curve (AUC), generally increased with the degree of substitution.Following gavage administration, Cmax and AUC of unsubstituted compound were lower compared to the substituted compounds. Cmax and AUC increased ≤7-fold with a 10-fold increase in the dose except for the AUC of the unsubstituted compound where the increase was 30-fold. Plasma elimination half-lives for the class ranged from 1.57 to 192 h with the exception of 30 mg/kg drometrizole.Oral bioavailability was low with â¼ 6% estimated for unsubstituted compound and 12.8-23% for others at 30 mg/kg dose. Bioavailability was lower following administration of the higher dose.Taken collectively, these data point to low oral absorption of phenolic benzotriazoles. The absorption decreased with increasing dose. Substituted compounds may be less metabolized compared to the unsubstituted.
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Fenóis , Administração Intravenosa , Administração Oral , Animais , Área Sob a Curva , Disponibilidade Biológica , Meia-Vida , Masculino , Fenóis/toxicidade , Ratos , Toxicocinética , TriazóisRESUMO
We investigated the plasma toxicokinetic behavior of free (parent) and total (parent and conjugated forms) of bisphenol S (BPS) and bisphenol AF (BPAF) in plasma of adult male rats and mice following exposure via feed for 7 days to BPS (338, 1125, and 3375 ppm) or BPAF (338, 1125, and 3750 ppm). In rats, the exposure concentration-normalized maximum concentration [Cmax/D (ng/mL)/(ppm)] and area under the concentration time curve [AUC/D (h × ng/mL)/(ppm)] for free was higher for BPS (Cmax/D: 0.476-1.02; AUC/D: 3.58-8.26) than for BPAF (Cmax/D: 0.017-0.037; AUC/D:0.196-0.436). In mice, the difference in systemic exposure parameters between free BPS (Cmax/D: 0.376-0.459; AUC/D: 1.52-2.54) and free BPAF (Cmax/D: 0.111-0.165; AUC/D:0.846-1.09) was marginal. Elimination half-lives for free analytes (4.41-10.4 h) were comparable between species and analogues. When systemic exposure to free analyte was compared between species, in rats, BPS exposure was slightly higher but BPAF exposure was much lower than in mice. BPS and BPAF were highly conjugated; total BPS AUC values (rats ≥18-fold, mice ≥17-fold) and BPAF (rats ≥127-fold, mice ≥16-fold) were higher than corresponding free values. Data demonstrated that there are analogue and species differences in the kinetics of BPS and BPAF.
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Compostos Benzidrílicos/farmacocinética , Substâncias Perigosas/farmacocinética , Fenóis/farmacocinética , Sulfonas/farmacocinética , Animais , Compostos Benzidrílicos/toxicidade , Substâncias Perigosas/toxicidade , Cinética , Masculino , Camundongos , Fenóis/toxicidade , Ratos , Sulfonas/toxicidade , Testes de Toxicidade , ToxicocinéticaRESUMO
Polycyclic aromatic compounds (PACs) are compounds with a minimum of two six-atom aromatic fused rings. PACs arise from incomplete combustion or thermal decomposition of organic matter and are ubiquitous in the environment. Within PACs, carcinogenicity is generally regarded to be the most important public health concern. However, toxicity in other systems (reproductive and developmental toxicity, immunotoxicity) has also been reported. Despite the large number of PACs identified in the environment, research attention to understand exposure and health effects of PACs has focused on a relatively limited subset, namely polycyclic aromatic hydrocarbons (PAHs), the PACs with only carbon and hydrogen atoms. To triage the rest of the vast number of PACs for more resource-intensive testing, we developed a data-driven approach to contextualize hazard characterization of PACs, by leveraging the available data from various data streams (in silico toxicity, in vitro activity, structural fingerprints, and in vivo data availability). The PACs were clustered on the basis of their in silico toxicity profiles containing predictions from 8 different categories (carcinogenicity, cardiotoxicity, developmental toxicity, genotoxicity, hepatotoxicity, neurotoxicity, reproductive toxicity, and urinary toxicity). We found that PACs with the same parent structure (e.g., fluorene) could have diverse in silico toxicity profiles. In contrast, PACs with similar substituted groups (e.g., alkylated-PAHs) or heterocyclics (e.g., N-PACs) with varying ring sizes could have similar in silico toxicity profiles, suggesting that these groups are better candidates for toxicity read-across analysis. The clusters/regions associated with certain in silico toxicity, in vitro activity, and structural fingerprints were identified. We found that genotoxicity/carcinogenicity (in silico toxicity) and xenobiotic homeostasis and stress response (in vitro activity), respectively, dominate the toxicity/activity variation seen in the PACs. The "hot spots" with enriched toxicity/activity in conjunction with availability of in vivo carcinogenicity data revealed regions of either data-poor (hydroxylated-PAHs) or data-rich (unsubstituted, parent PAHs) PACs. These regions offer potential targets for prioritization of further in vivo assessment and for chemical read-across efforts. The analysis results are searchable through an interactive web application (https://ntp.niehs.nih.gov/go/pacs_tableau), allowing for alternative hypothesis generation.
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Monitoramento Ambiental , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Testes de Toxicidade , Análise de Componente PrincipalRESUMO
Large-scale gene expression analysis of legacy* and emerging** brominated flame retardants were conducted in the male Harlan Sprague Dawley rat [1]. Each animal was dosed for 5 days with the chemical at concentrations of 0.1 - 1000 µmol/kg body weight per day. Following the last dose, a specimen of the left liver was removed for RNA extraction. The amplified RNA (aRNA) was fragmented and then hybridized to Affymetrix Rat Genome 230 2.0 Arrays. Each GeneChip® array was scanned using an Affymetrix GeneChip® Scanner 3000 7â¯G to generate raw expression level data (.CEL files). Statistical contrasts were used to find pairwise gene expression differences between the control group and each dose group using the R/maanova package [2]. The transcriptomic data can be used to provide insights into the degree of toxicity, toxic mechanisms, disease pathways activated by exposure, and for benchmark dose analysis. The gene expression data for each of the nine flame retardants discussed here accompanies the research article entitled, "Comparative Toxicity and Liver Transcriptomics of Legacy and Emerging Brominated Flame Retardants following 5-Day Exposure in the Rat" [1]. * polybrominated diphenyl ether 47 (PBDE 47), decabromodiphenyl ether (decaBDE), hexabromocyclododecane (HBCD); ** 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB); bis(2-ethylhexyl) tetrabromophthalate (TBPH); tetrabromobisphenol A-bis(2,3-dibromopropyl ether (TBBPA-DBPE); 1,2-bis(tribromophenoxy)ethane (BTBPE); decabromodiphenylethane (DBDPE); hexachlorocyclopentadienyl-dibromocyclooctane (HCDBCO).
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Immature dendritic cells (IDc), 'dexosomes', are promising natural nanomaterials for cancer diagnose and therapy. Dexosomes were isolated purely from small-scale-up production by using t25-cell-culture flasks. Total RNA was measured as 1.43 ± 0.33 ng/106 cell. Despite the fact that they possessed a surface that is highly abundant in protein, this did not become a significant effect on the DOX loading amount. Ultrasonication was used for doxorubicin (DOX) loading into the IDc dexosomes. In accordance with the literature, three candidate DOX formulations were designed as IC50 values; dExoIII, 1.8 µg/mL, dExoII, 1.2 µg/mL, and dExoI, 0.6 µg/mL, respectively. Formulations were evaluated by MTT test against highly metastatic A549 (CCL-185; ATTC) cell line. Confocal images of unloaded (naïve) were obtained by CellMaskTM membrane staining before DOX loading. Although, dexosome membranes were highly durable subsequent to ultrasonication, it was observed that dexosomes could not be stable above 70 °C during the SEM-image analyses. dExoIII displayed sustained release profile. It was found that dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) results were in good agreement with each other. Zeta potentials of loaded dexosomes have approximately between -15 to -20 mV; and, their sizes are 150 nm even after ultrasonication. IDcJAWSII dexosomes can be able to be utilized as the "BioNanoMaterial" after DOX loading via ultrasonication technique.
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The relative toxicity of three legacy and six emerging brominated flame retardants* was studied in the male Harlan Sprague Dawley rat. The hepatocellular and thyroid toxicity of each flame retardant was evaluated following five-day exposure to each of the nine flame retardants (oral gavage in corn oil) at 0.1-1000⯵mol/kg body weight per day. Histopathology and transcriptomic analysis were performed on the left liver lobe. Centrilobular hypertrophy of hepatocytes and increases in liver weight were seen following exposure to two legacy (PBDE-47, HBCD) and to one emerging flame retardant (HCDBCO). Total thyroxine (TT4) concentrations were reduced to the greatest extent after PBDE-47 exposure. The PBDE-47, decaBDE, and HBCD liver transcriptomes were characterized by upregulation of liver disease-related and/or metabolic transcripts. Fewer liver disease or metabolic transcript changes were detected for the other flame retardants studied (TBB, TBPH, TBBPA-DBPE, BTBPE, DBDPE, or HCDBCO). PBDE-47 exhibited the most disruption of hepatocellular toxic endpoints, with the Nrf2 antioxidant pathway transcripts upregulated to the greatest extent, although some activation of this pathway also occurred after decaBDE, HBCD, TBB, and HCBCO exposure. These studies provide information that can be used for prioritizing the need for more in-depth brominated flame retardant toxicity studies.