International Journal of Toxicology
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Published By Sage Publications

1092-874x, 1091-5818

2021 ◽  
pp. 109158182110628
Author(s):  
Jessica F. Hoffman ◽  
Vernieda B. Vergara ◽  
John F. Kalinich

With shrapnel injuries, the metal fragment is usually left in place to reduce the risk of morbidity extensive surgery might bring. This means the individual may retain those metals for the remainder of their life. Often the long-term health effects of the embedded metal are not known, especially with respect to protein damage and perturbations of muscle repair pathways. In this study, using homogenates of rat gastrocnemius muscle implanted with pellets of military-relevant metals, we investigated expression of iNOS and eNOS, enzymes involved in nitric oxide production, as well as MMP-2 and MMP-9, matrix metalloproteinases associated with muscle repair. In addition, hydroxynonenal-modified proteins were investigated to assess metal-induced oxidative damage and metal levels in the gastrocnemius determined. Metals were implanted for up to 12 months in order to determine the long-term effects on the expression of muscle-associated proteins. With the exception of iron and cobalt at 1-month post-implantation, there were no significant differences in metal levels in the gastrocnemius in any of the cohorts. Protein expression analysis showed significant decreases in iNOS and eNOS in the 6-month and 12-month lead and depleted uranium groups. Hydroxynonenal-modified proteins were also significantly increased in the iron, copper, lead, and depleted uranium groups. These results suggest that some embedded metals can induce long-term oxidative damage, as well as affect enzyme systems involved in signal transduction.


2021 ◽  
pp. 109158182110566
Author(s):  
Lanjie Pei ◽  
Wenxiang Yang ◽  
Yi Cao

Since the possible roles of surface modifications in determining multi-walled carbon nanotube (MWCNT)–promoted endoplasmic reticulum (ER) stress-mediated lipid-laden macrophage foam cell formation are still in debate, we compared unmodified and carboxylated MWCNT-induced cytotoxicity, lipid profile changes, and expression of ER stress genes in THP-1 macrophages. Particularly, we focused on lipid profile changes by using lipidomics approaches. We found that unmodified and carboxylated MWCNTs significantly decreased cellular viability and appeared to damage the cellular membrane to a similar extent. Likewise, the results from Oil Red O staining showed that both types of MWCNTs slightly but significantly induced lipid accumulation. In keeping with Oil Red O staining results, lipidomics data showed that both types of MWCNTs up-regulated most of the lipid classes. Interestingly, almost all lipid classes were relatively higher in carboxylated MWCNT-exposed THP-1 macrophages compared with unmodified MWCNT-exposed cells, indicating that carboxylated MWCNTs more effectively changed lipid profiles. But in contrast to our expectation, none of the MWCNTs significantly induced the expression of ER stress genes. Even, compared with carboxylated MWCNTs, unmodified MWCNTs induced higher expression of lipid genes, including macrophage scavenger receptor 1 and fatty acid synthase. Combined, our results suggested that even though carboxylation did not significantly affect MWCNT-induced lipid accumulation, carboxylated MWCNTs were more potent to alter lipid profiles in THP-1 macrophages, indicating the need to use omics techniques to understand the exact nanotoxicological effects of MWCNTs. However, the differential effects of unmodified and carboxylated MWCNTs on lipid profiles might not be related with the induction of ER stress.


2021 ◽  
Vol 40 (3_suppl) ◽  
pp. 53S-76S
Author(s):  
Christina L. Burnett ◽  
Wilma F. Bergfeld ◽  
Donald V. Belsito ◽  
Ronald A. Hill ◽  
Curtis D. Klaassen ◽  
...  

The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) assessed the safety of 33 Citrus flower- and leaf-derived ingredients, which are most frequently reported to function in cosmetics as fragrances and/or skin-conditioning agents. The Panel reviewed the available data to determine the safety of these ingredients. Because final product formulations may contain multiple botanicals, each containing similar constituents of concern, formulators are advised to be aware of these constituents and to avoid reaching levels that may be hazardous to consumers. With Citrus flower- and leaf-derived ingredients, the Panel was concerned about the presence of the hydroperoxides of limonene and linalool in cosmetics. Industry should use good manufacturing practices to limit impurities that could be present in botanical ingredients. The Panel concluded that these ingredients are safe in the present practices of use and concentration when formulated to be non-irritating and non-sensitizing.


2021 ◽  
pp. 109158182110481
Author(s):  
Yuki Asai ◽  
Takanori Yamamoto ◽  
Yasuharu Abe

Drug-induced thrombocytopenia (DITP) can be triggered by antibiotics; however, the details remain unclear. Here, we evaluated the expression profiles of DITP using the Japanese Adverse Drug Event Report (JADER) database. We analyzed reports of DITP between April 2004 and January 2021 from the JADER database. The reporting odds ratio (ROR) and 95% confidence interval (CI) were used to detect DITP signals. Factors thought to affect DITP, such as male sex and an age of at least 60 years, were added as covariates. We evaluated the time-to-onset profile and hazard type using the Weibull shape parameter. The JADER database contained 1,048,576 reports. Twelve of 60 antibiotics showed signals for DITP; the RORs (95% CIs) for ampicillin/sulbactam, ceftazidime, cefozopran, ciprofloxacin, fluconazole, fos-fluconazole, linezolid, pazufloxacin, piperacillin/tazobactam, teicoplanin, trimethoprim/sulfamethoxazole, and voriconazole were 1.75 (1.41-2.16), 1.77 (1.42-2.18), 1.35 (1.06-1.72), 2.56 (2.19-2.98), 1.93 (1.67-2.23), 2.08 (1.76-2.46), 5.29 (2.73-9.60), 1.92 (1.51-2.41), 1.54 (1.05-2.19), 1.47 (1.16-1.84), 1.92 (1.73-2.14), and 2.32 (1.59-3.30), respectively. In multiple logistic regression analysis, 7 and 6 antibiotics were detected for the factors age and male sex, respectively. The median times-to-onset of DITP for ciprofloxacin (oral treatment), fluconazole, linezolid, piperacillin/tazobactam, and trimethoprim/sulfamethoxazole were 91, 91, 11.5, 10, and 9 days, respectively. Furthermore, the 95% CI of the Weibull shape parameter β for these antibiotics was above and excluded 1, indicating that the antibiotics were the wear out failure type. We revealed the expression profiles of DITP following treatment with 12 antibiotics.


2021 ◽  
pp. 109158182110404
Author(s):  
Emmanuel Boulay ◽  
Eric Troncy ◽  
Michael Pugsley ◽  
Joey St-Pierre ◽  
Anne-Marie Downey ◽  
...  

Respiratory monitoring, using impedance with implanted telemetry in socially housed animals, was not possible until the recent development of digital signal transmission. The objective of this study was to evaluate digital telemetry monitoring of cardiopulmonary parameters (respiratory rate, tidal volume, minute volume, electrocardiography (DII), systemic arterial blood pressure, physical activity, and body temperature) in conscious, single-housed, non-rodent species commonly used in toxicology studies following administration of positive/negative controls (saline, dexmedetomidine, morphine, amphetamine, and doxapram), and also, the effects of various social housing arrangements in untreated female and/or male cynomolgus monkeys, Beagle dogs, and Göttingen minipigs (n = 4 per species). Aggressions were observed in socially housed male minipigs, however, which prevented pair-housed assessments in this species. All tested pharmacological agents significantly altered more than one organ system, highlighting important inter-organ dependencies when analyzing functional endpoints. Stress-related physiological changes were observed with single-housing or pair-housing with a new cage mate in cynomolgus monkeys and Beagle dogs, suggesting that stable social structures are preferable to limit variability, especially around dosing. Concomitant monitoring of cardiovascular and respiratory parameters from the same animals may help reduce the number of animals (3 Rs) needed to fulfill the S7A guidelines and allows for identification of organ system functional correlations. Globally, the data support the use of social housing in non-rodents for safety pharmacology multi-organ system (heart and lungs) monitoring investigations.


2021 ◽  
pp. 109158182110479
Author(s):  
Satoru Asami ◽  
Mikana Suzuki ◽  
Toshimitsu Nakayama ◽  
Yasuyo Shimoda ◽  
Motofumi Miura ◽  
...  

Research suggests that thioether analogs of vitamin K3 (VK3) can act to preserve the phosphorylation of epidermal growth factor receptors by blocking enzymes (phosphatases) responsible for their dephosphorylation. Additionally, these derivatives can induce apoptosis via mitogen-activated protein kinase and caspase-3 activation, inducing reactive oxygen species (ROS) production, and apoptosis. However, vitamin K1 exhibits only weak inhibition of phosphatase activity, while the ability of VK3 to cause oxidative DNA damage has raised concerns about carcinogenicity. Hence, in the current study, we designed, synthesized, and screened a number of VK3 analogs for their ability to enhance phosphorylation activity, without inducing off-target effects, such as DNA damage. 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay revealed that each analog produced a different level of cytotoxicity in the Jurkat human leukemia cell line; however, none elicited a cytotoxic effect that differed significantly from that of the control. Of the VK3 analogs, CPD5 exhibited the lowest EC50, and flow cytometry results showed that apoptosis was induced at final concentrations of ≥10 μM; hence, only 0.1, 1, and 10 μM were evaluated in subsequent assays. Furthermore, CPD5 did not cause vitamin K-attributed ROS generation and was found to be associated with a significant increase in caspase 3 expression, indicating that, of the synthesized thioether VK3 analogs, CPD5 was a more potent inducer of apoptosis than VK3. Hence, further elucidation of the apoptosis-inducing effect of CPD5 may reveal its efficacy in other neoplastic cells and its potential as a medication.


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