Toxicology Mechanisms and Methods最新文献

Background: Previous studies show that spinal cord ischemia and hypoxia is an important cause of spinal cord necrosis and neurological loss. Therefore, the study aimed to identify genes related to ischemia and hypoxia after spinal cord injury (SCI) and analyze their functions, regulatory mechanism, and potential in regulating immune infiltration.

Methods: The expression profiles of GSE5296, GSE47681, and GSE217797 were downloaded from the Gene Expression Omnibus database. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed to determine the function and pathway enrichment of ischemia- and hypoxia-related differentially expressed genes (IAHRDEGs) in SCI. LASSO model was constructed, and support vector machine analysis was used to identify key genes. The diagnostic values of key genes were evaluated using decision curve analysis and receiver operating characteristic curve analysis. The interaction networks of miRNAs-IAHRDEGs and IAHRDEGs-transcription factors were predicted and constructed with the ENCORI database and Cytoscape software. CIBERSORT algorithm was utilized to analyze the correlation between key gene expression and immune cell infiltration.

Results: There were 27 IAHRDEGs identified to be significantly expressed in SCI at first. These genes were mostly significantly enriched in wound healing function and the pathway associated with lipid and atherosclerosis. Next, five key IAHRDEGs (Abca1, Casp1, Lpl, Procr, Tnfrsf1a) were identified and predicted to have diagnostic value. Moreover, the five key genes are closely related to immune cell infiltration.

Conclusion: Abca1, Casp1, Lpl, Procr, and Tnfrsf1a may promote the pathogenesis of ischemic or hypoxic SCI by regulating vascular damage, inflammation, and immune infiltration.

Purpose: This study sought to identify drug target genes and their associated molecular mechanisms during isoflurane-induced anesthesia in clinical applications.

Methods: Microarray data (ID: GSE64617; isoflurane-treated vs. normal samples) were downloaded from the Gene Expression Omnibus database. Differentially expressed genes (DEGs) were screened and hub genes were investigated using weighted correlation network analysis (WGCNA). Protein-protein interactions (PPIs) were constructed among the co-DEGs (common genes between DEGs and hub genes), followed by functional enrichment analyses. Then, three machine learning methods were used to reveal drug targets, followed by validation, nomogram analysis, and gene set enrichment analysis. Finally, an miRNA-target network was constructed.

Results: A total of 686 DEGs were identified between the two groups-of which, 183 DEGs integrated with genes revealed by WCGNA were identified as co-genes. These genes, including contactin-associated protein 1 (CNTNAP1), are mainly involved in functions such as action potentials. PPI network analysis revealed three models, with the machine learning analysis exploring four drug target genes: A2H, FAM155B, SCARF2, and SDR16C5. ROC and nomogram analyses demonstrated the ideal diagnostic value of these target genes. Finally, miRNA-mRNA pairs were constructed based on the four mRNAs and associated 174 miRNAs.

Conclusion: FA2H, FAM155B, SCARF2, and SDR16C5 may be novel drug target genes for isoflurane-induced anesthesia. CNTNAP1 may participate in the progression of isoflurane-induced anesthesia via its action potential function.

A 30 year old man was found with no signs of life in front of the house. The cyanide concentration in blood and urine was determined five years after the man's death. What is more, a stability study was conducted for 730 days in an authentic casework blood sample. Sample preparation procedure included precipitation with methanol:water mixture, solid phase extraction (SPE) and derivatization with the use of PFB-Br (pentafluorobenzyl bromide). The sample was analyzed using GC-QqQ-MS/MS (gas chromatopraphy coupled with tandem mass spectrometry) isotope dilution method. Separation was done using a SH-RXI-5MS column (30 m x 0.25 mm, 0.25 µm). Detection of PFB-CN and PFB-¹³CN was achieved using a triple-quadrupole mass spectrometer with an electron ionization (EI) ion source in multiple reaction monitoring (MRM) mode. After 5 years from the man's death, cyanide concentration was: 1900 ng/mL in blood and 500 ng/mL in urine. Stability study performed in an authentic blood sample 6 and 7 years after the man's death revealed cyanide concentrations of 1898.2 ng/mL and 1618.7 ng/mL, respectively. While spectrophotometric and colorimetric methods recorded both decrease and increase in cyanide concentration over time, newer chromatographic methods mainly indicate a decrease. The studies presented in this paper seem to confirm this trend. However, in order to interpretate the results of cyanide concentration in biological material reliably, more research is still necessary.

Crude oil spilled at sea is chemically altered through environmental processes such as dissolution, biodegradation, and photodegradation. Transformation of hydrocarbons to oxygenated species increases water-solubility. Metabolites and oxidation products largely remain uncharacterized by common analytical methods but may be more bioavailable to aquatic organisms. Studies have shown that unresolved (i.e. unidentified) polar compounds ('UPCs') may constitute > 90% of the water-accommodated fraction (WAF) of heavily weathered crude oils, but still there is a paucity of information characterizing their toxicological significance in relation to other oil-derived toxicants. In this study, low-energy WAFs (no droplets) were generated from two field-weathered oils (collected during the 2010 Deepwater Horizon incident) and their polar fractions were isolated through fractionation. To allow establishment of thresholds for acute toxicity (LC₅₀) of the dissolved and polar fraction of field collected oils, we concentrated both WAFs and polar fractions to beyond field-documented concentrations, and the acute toxicity of both to the marine copepod Acartia tonsa was measured and compared to the toxicity of the native WAF (non-concentrated). The difference in toxic units (TUs) between the total of the mixture and of identified compounds of known toxicity (polycyclic aromatic hydrocarbons [PAHs] and alkyl phenols) in both WAF and polar fractions was used to estimate the contribution of the UPC to overall toxicity. This approach identified that UPC had a similar contribution to toxicity as identified compounds within the WAFs of the field-weathered oils. This signifies the relative importance of polar compounds when assessing environmental impacts of spilled and weathered oil.

In a world with a rising use of pesticides, these chemicals, although designed to effectively control pests, pose potential threats to the environment and non-target organisms, including humans. Thus, this systematic review aims to investigate a possible association between genetic polymorphisms and susceptibility and genotoxicity in individuals occupationally exposed to pesticides. This review was conducted following the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. A total of 14 carefully selected studies were thoroughly analyzed by two reviewers, who assigned scores based on previously set evaluation criteria. This study classified over half of the chosen studies as having moderate or strong quality, observing a correlation between certain genetic polymorphisms involved in xenobiotic metabolism and genotoxicity in workers exposed to pesticides. Results suggest that the genes associated with xenobiotic metabolism play a substantial role in determining individuals' susceptibility to genomic damage due to pesticide exposure, affecting both their peripheral blood and oral mucosa. This implies that individuals with specific genotypes may experience increased or decreased levels of DNA damage when exposed to these chemicals.

As an estrogenic agent, Bisphenol A Dimethacrylate (Bis-DMA) may incite alterations in both the reproductive tract and the neuroendocrine axis, and thus have the potential to affect the proper development, maturity and conceptive performance in animals. We investigated the consequences of 14 weeks of exposure to different concentrations of Bis-DMA on male mouse conceptive performance. Male mice were exposed to Bis-DMA (0, 0.1 mg/L, 1.0 mg/L or 10 mg/L) via drinking water, and the effects on fertility, reproductive organ weights, reproductive hormone levels, sperm counts and testicular histology were assessed. We clearly demonstrate that prolonged exposure of male mice to Bis-DMA negatively affects fertility and reproduction causing significant reductions in sperm counts, non-monotonic effects on serum LH and testosterone levels, increased seminal vesicle weights, lower number of embryonic implantations and viable fetuses, as well as, increased embryonal resorptions in females mated by Bis-DMA treated males. Furthermore, Bis-DMA caused abnormalities in testicular infrastructure with atrophic seminiferous tubules exhibiting intraepithelial vacuolization and disorganization, loss and shedding of germ cells into the lumen, and presence of apoptotic cells. Our data collectively suggest that Bis-DMA adversely affects male fertility and reproduction by interference with normal hormone signaling in the testis, inducing changes in testicular infrastructure and ultimately leading to impaired reproductive function and fertility.

In recent years one of the most striking results of over-population and consumption activities in the world is the rapid increase in environmental pollutants. Environmental pollutants, one of the harmful consequences of technological and modern life, threaten the health of people and other living organisms. In this study, we aimed to determine the effects of sodium omadine (NaOM) on superoxide dismutase enzyme (SOD) activity as an antioxidant and on 8-OHdG levels as oxidative DNA damage in zebrafish. Zebrafish, obtained from the aquarium fish producer, were stocked in experimental aquariums to ensure their adaptation period to the experimental conditions 15 days before the experiment. The fish were exposed to 1 ug/L and 5 ug/L concentrations of NaOM for 24, 72, and 96 h. SOD enzyme activity (U/100 mg tissue) and 8-OHdG (pg/100 mg tissue) were measured using commercial kits. The statistically significant differences in tissue SOD levels and data for DNA damage between the groups were determined as time and dose-dependent (p < 0.05). Biocidal products are environmental pollutants that cause changes in antioxidant enzyme activities, especially in non-target organisms. Marine pollution and the degradation of ecosystems directly affect people, and the results of the study offer awareness of health problems, environmental pollution, and marine pollution.

Disruption of the immune system during embryonic brain development by environmental chemicals was proposed as a possible cause of neurodevelopmental disorders. We previously found adverse effects of di-n-octyltin dichloride (DOTC) on maternal and developing immune systems of rats in an extended one-generation reproductive toxicity study according to the OECD 443 test guideline. We hypothesize that the DOTC-induced changes in the immune system can affect neurodevelopment. Therefore, we used in-vivo MRI and PET imaging and genomics, in addition to behavioral testing and neuropathology as proposed in OECD test guideline 443, to investigate the effect of DOTC on structural and functional brain development. Male rats were exposed to DOTC (0, 3, 10, or 30 mg/kg of diet) from 2 weeks prior to mating of the F0-generation until sacrifice of F1-animals. The brains of rats, exposed to DOTC showed a transiently enlarged volume of specific brain regions (MRI), altered specific gravity, and transient hyper-metabolism ([¹⁸F]FDG PET). The alterations in brain development concurred with hyper-responsiveness in auditory startle response and slight hyperactivity in young adult animals. Genomics identified altered transcription of key regulators involved in neurodevelopment and neural function (e.g. Nrgrn, Shank3, Igf1r, Cck, Apba2, Foxp2); and regulators involved in cell size, cell proliferation, and organ development, especially immune system development and functioning (e.g. LOC679869, Itga11, Arhgap5, Cd47, Dlg1, Gas6, Cml5, Mef2c). The results suggest the involvement of immunotoxicity in the impairment of the nervous system by DOTC and support the hypothesis of a close connection between the immune and nervous systems in brain development.

Microextractions have been developed for the tricyclic antidepressants (TCAs) analysis in biological matrices, including dispersive liquid-liquid microextraction (DLLME). The proposed DLLME employed 490 µL of biological sample (whole blood or plasma), which were added 15 mg of NaCl, 10 µL of medazepam as internal standard (10 µg/mL) and 100 µL of 2 M NaOH. This mixture was homogenized by vortex (2800 rpm/10 s) and 400 µL of hexane (extractor solvent) with 600 µL of methanol (dispersing solvent) were added to the sample. After the vortex step (2800 rpm/5 s), an ultrasonic bath for 300 s was employed. Then, this content was centrifuged (10 min/10000 rpm), organic phase was collected and dried under air flow. After, 30 µL of the mobile phase was used for resuspension and 20 µL is injected into LC-DAD. This method was optimized and fully validated according to UNODC and SWGTOX guidelines, reaching limits of detection equivalent to analytical methodologies that employ mass spectrometry (MS). Also, it was applied in real cases involving suspected exposure to TCAs. So, the developed DLLME for the determination of TCAs in whole blood and plasma samples proved to be a simple, reliable, robust and reproducible method that can be used in toxicology and clinical laboratories.

Salicylic acid topical is used to treat variety of skin conditions. However, salicylic acid in these products is generated through industrial synthesis and has been shown to negatively impact fetal development and cause congenital abnormalities. We hypothesized that teratogenic effects reported in salicylic acid can be prevented by naturally synthesizing salicylic acid from wintergreen oil using green chemistry method. For this purpose, we investigated the effects of natural salicylic acid (NSA) synthesized from wintergreen oil using green chemistry and synthetic salicylic acid (SSA) on keratinocyte cell (HaCaT) proliferation and zebrafish embryo development. NSA structures were analyzed by ¹H NMR, ¹³C NMR, and GC/MS methods. Percentage inhibition against HaCaT cell was determined by MTS assay. xCelligence system was used for cellular activities. Zebrafish embryos were exposed to NSA and SSA for 72 h post-fertilization. Lipid peroxidation, nitric oxide, sialic acid, glutathione-S-transferase, catalase, and superoxide dismutase were evaluated using biochemical methods. Expressions of nqO1, gfap, bdnf, vtg, egr, cyp1a, and igf2 were determined by RT-PCR as developmental indicators. MTS and RT-cell analysis showed increased cell viability by NSA, whereas SSA decreased cell viability. NSA beneficially affected zebrafish embryo development while SSA exerted deleterious effects through oxidant-antioxidant status, inflammation, and development. Results of our study showed for the first time that synthesis of salicylic acid from wintergreen oil by green chemistry overcomes its cytotoxicity in keratinocyte cells and teratogenicity in zebrafish embryos. This finding is important for drug research on safe topical applications during pregnancy, when preventing exposure to drug and chemical-derived teratogens is vital.