-
Current Opinion in Microbiology Oct 2021Catabolic bacterial microcompartments (BMC), or metabolosomes, are self-assembling structures formed by enzymes enclosed by porous protein shells. They provide a... (Review)
Review
Catabolic bacterial microcompartments (BMC), or metabolosomes, are self-assembling structures formed by enzymes enclosed by porous protein shells. They provide a specialised environment inside bacterial cells separating a short catabolic pathway with reactive or toxic intermediates from the cytoplasm. Substrates for microcompartment metabolism like ethanolamine and 1,2-propanediol are constantly produced in the human intestine by bacterial metabolism of food or host cell components. Enteric pathogens gain a competitive advantage in the intestine by metabolising these substrates, an advantage enhanced by the host inflammatory response. They exploit the intestinal specificity of signature metabolosome substrates by adopting substrate sensors and regulators encoded by BMC operons for governance of non-metabolic processes in pathogenesis. In turn, products of microcompartment metabolism regulate the host immune system.
Topics: Bacteria; Bacterial Proteins; Ethanolamine; Humans; Propylene Glycol; Virulence
PubMed: 34107380
DOI: 10.1016/j.mib.2021.05.009 -
Magnetic Resonance in Chemistry : MRC Nov 2016The variability of the electronic cigarette liquids (e-liquid) composition has the potential to influence not only the amount of nicotine delivered to the user, but also...
The variability of the electronic cigarette liquids (e-liquid) composition has the potential to influence not only the amount of nicotine delivered to the user, but also the type and amount of generated byproducts and subsequent health risks. For this reason, it is important to characterize all of the chemical components of e-liquids. We report the development and application of a single H NMR analysis method to identify and quantify the most abundant chemical components (nicotine, glycerol, 1,2-propylene glycol, and water) likely to be present as their influence on the composition of inhaled vapor is not know. For H NMR, the solvent has to dissolve the e-liquids at a concentration sufficient to readily determine the concentration of nicotine present, and the solvent and internal standard cannot possess exchangeable protons which would interfere with determining the concentrations of the analytes of interest. To fulfill these requirements, perdeuterated -dimethylformamide (DMF-) was selected as the solvent, with 1,2,4,5-tetrachloro-3-nitrobenzene as the internal standard. Nicotine concentrations from 58 different e-liquids obtained using H NMR were found to agree with the results from GC-MS analysis. Generally, the amount of nicotine present was close to that claimed by the manufacturer. In some cases, the proportions of 1,2-propylene glycol, glycerol, and water varied significantly between flavors within a brand and within flavors depending on the nicotine content. In one case, 1,2-propylene glycol was identified where the manufacturer had stated none should be present.
Topics: Electronic Nicotine Delivery Systems; Glycerol; Nicotine; Propylene Glycol; Proton Magnetic Resonance Spectroscopy; Solvents; Water
PubMed: 27495876
DOI: 10.1002/mrc.4498 -
Journal of Applied Oral Science :... 2015To investigate the physical (setting time, hardness, flowability, microstructure) and chemical (pH change, calcium release, crystallinity) properties and the biological...
OBJECTIVE
To investigate the physical (setting time, hardness, flowability, microstructure) and chemical (pH change, calcium release, crystallinity) properties and the biological outcomes (cell survival and differentiation) of mineral trioxide aggregate (MTA) mixed using different proportions of propylene glycol (PG) and water.
MATERIAL AND METHODS
White MTA was mixed with different water/PG ratios (100/0, 80/20 and 50/50). Composition (XRD), microstructure (SEM), setting time (ASTM C266-13), flowability (ANSI/ADA 57-2000), Knoop hardness (100 g/10 s) and chemical characteristics (pH change and Ca2+ release for 7 days) were evaluated. Cell proliferation, osteo/odontoblastic gene expression and mineralization induced by MTA mixed with PG were evaluated. MTA discs (5 mm in diameter, 2 mm thick) were prepared and soaked in culture medium for 7 days. Next, the discs were removed and the medium used to culture dental pulp stem cells (DPSC) for 28 days. Cells survival was evaluated using MTS assay (24, 72 and 120 h) and differentiation with RT-PCR (ALP, OCN, Runx2, DSPP and MEPE) and alizarin red staining (7 and 14 days). Data were analysed using one-way ANOVA and Tukey's post-hoc analysis (a=0.05).
RESULTS
The addition of PG significantly increased setting time, flowability and Ca2+ release, but it compromised the hardness of the material. SEM showed that 50/50 group resulted porous material after setting due to the incomplete setting reaction, as shown by XRD analysis. The addition of PG (80/20 and 50/50) was not capable to improve cell proliferation or to enhance gene expression, and mineralized deposition of DPSC after 7 and 14 days as compared to the 100/0.
CONCLUSION
Except for flowability, the addition of PG did not promote further improvements on the chemical and physical properties evaluated, and it was not capable of enhancing the bioactivity of the MTA.
Topics: Aluminum Compounds; Analysis of Variance; Calcium Compounds; Cell Survival; Cells, Cultured; Dental Pulp; Drug Combinations; Gene Expression; Hardness Tests; Humans; Materials Testing; Microscopy, Electron, Scanning; Oxides; Propylene Glycol; Real-Time Polymerase Chain Reaction; Rheology; Silicates; Stem Cells; Time Factors
PubMed: 26398513
DOI: 10.1590/1678-775720150084 -
Current Allergy and Asthma Reports Mar 2021This article aims to summarize some recent trends in occupational allergic contact dermatitis (ACD), including dermatitis related to pandemic-level personal protective... (Review)
Review
PURPOSE OF REVIEW
This article aims to summarize some recent trends in occupational allergic contact dermatitis (ACD), including dermatitis related to pandemic-level personal protective equipment in healthcare workers, hazards patients may experience when working from home, and occupational perspectives on the recent American Contact Dermatitis Society (ACDS) allergens of the year and ACDS Core Allergen Series updates.
RECENT FINDINGS
Recent ACDS Allergens of the Year may be particularly relevant to healthcare workers, including isobornyl acrylate, which is present in glucose sensors and propylene glycol present in hand cleansers and disinfectants. Lavender, limonene, and linalool, all of which are new additions to the ACDS Core Allergen Series, have been reported as causes for occupational ACD in massage therapists and aromatherapists. Isothiazolinone allergy continues to rise in both consumer and occupational settings. Finally, the COVID-19 pandemic has resulted in a wave of occupational ACD in healthcare workers to personal protective equipment, and revealed new potential allergens for individuals working from home. Occupational allergic contact dermatitis continues to exert a significant occupational disease burden. Remaining aware of the current trends in allergens may allow for earlier recognition, diagnosis, and treatment, subsequently helping our patients to work in healthier and safer environments.
Topics: Acrylates; Acyclic Monoterpenes; Allergens; Allergy and Immunology; COVID-19; Camphanes; Dermatitis, Allergic Contact; Dermatitis, Occupational; Dermatology; Health Personnel; Humans; Lavandula; Limonene; Pandemics; Patch Tests; Propylene Glycol; Societies, Medical; United States
PubMed: 33779825
DOI: 10.1007/s11882-021-01000-3 -
Nicotine & Tobacco Research : Official... Nov 2023Although the greater popularity of electronic cigarettes (EC) among asthmatics is alarming, there is limited knowledge of the long-term consequences of EC exposure in...
INTRODUCTION
Although the greater popularity of electronic cigarettes (EC) among asthmatics is alarming, there is limited knowledge of the long-term consequences of EC exposure in asthmatics.
AIMS AND METHODS
Mild asthmatic C57/BL6J adult male and female mice were established by intranasal insufflation with three combined allergens. The asthmatic and age and sex-matched' naïve mice were exposed to air, nicotine-free (propylene glycol [PG]/vegetable glycerin [VG]-only), or PG/VG+Nicotine, 4 hours daily for 3 months. The effects of EC exposure were accessed by measuring cytokines in bronchoalveolar lavage, periodic acid-schiff (PAS) staining, mitochondrial DNA copy numbers (mtCN), and the transcriptome in the lung. Significance was false discovery rate <0.2 for transcriptome and 0.05 for the others.
RESULTS
In asthmatic mice, PG/VG+Nicotine increased PAS-positive cells and IL-13 compared to mice exposed to air and PG/VG-only. In naïve mice exposed to PG/VG+Nicotine and PG/VG-only, higher INF-γ was observed compared to mice exposed only to air. PG/VG-only and PG/VG+Nicotine had significantly higher mtCN compared to air exposure in asthmatic mice, while the opposite pattern was observed in non-asthmatic naïve mice. Different gene expression patterns were profoundly found for asthmatic mice exposed to PG/VG+Nicotine compared to PG/VG-only, including genes involved in mitochondrial dysfunction, oxidative phosphorylation, and p21-activated kinase (PAK) signaling.
CONCLUSIONS
This study provides experimental evidence of the potential impact of nicotine enhancement on the long-term effects of EC in asthmatics compared to non-asthmatics.
IMPLICATIONS
The findings from this study indicate the potential impact of EC in asthmatics by addressing multiple biological markers. The long-term health outcomes of EC in the susceptible group can be instrumental in supporting policymaking and educational campaigns and informing the public, healthcare providers, and EC users about the underlying risks of EC use.
Topics: Male; Mice; Female; Animals; Nicotine; Electronic Nicotine Delivery Systems; Asthma; Lung; Propylene Glycol; Glycerol; Vegetables
PubMed: 37349133
DOI: 10.1093/ntr/ntad100 -
The Journal of Reproduction and... 2013Our aim was to optimize a cryoprotectant treatment for vitrification of immature porcine cumulus-oocyte complexes (COCs). Immature COCs were vitrified either in 35%... (Comparative Study)
Comparative Study
Our aim was to optimize a cryoprotectant treatment for vitrification of immature porcine cumulus-oocyte complexes (COCs). Immature COCs were vitrified either in 35% ethylene glycol (EG), 35% propylene glycol (PG) or a combination of 17.5% EG and 17.5% PG. After warming, the COCs were in vitro matured (IVM), and surviving oocytes were in vitro fertilized (IVF) and cultured. The mean survival rate of vitrified oocytes in 35% PG (73.9%) was higher (P<0.05) than that in 35% EG (27.8%). Oocyte maturation rates did not differ among vitrified and non-vitrified control groups. Blastocyst formation in the vitrified EG group (10.8%) was higher (P<0.05) than that in the vitrified PG group (2.0%) but was lower than that in the control group (25.0%). Treatment of oocytes with 35% of each cryoprotectant without vitrification revealed a higher toxicity of PG on subsequent blastocyst development compared with EG. The combination of EG and PG resulted in 42.6% survival after vitrification. The maturation and fertilization rates of the surviving oocytes were similar in the vitrified, control and toxicity control (TC; treated with EG+PG combination without cooling) groups. Blastocyst development in the vitrified group was lower (P<0.05) than that in the control and TC groups, which in turn had similar development rates (10.7%, 18.1% and 23.3%, respectively). In conclusion, 35% PG enabled a higher oocyte survival rate after vitrification compared with 35% EG. However, PG was greatly toxic to oocytes. The combination of 17.5% EG and 17.5% PG yielded reasonable survival rates without toxic effects on embryo development.
Topics: Animals; Cryopreservation; Cryoprotective Agents; Embryonic Development; Ethylene Glycol; Female; Fertilization in Vitro; Male; Oocytes; Propylene Glycol; Swine; Vitrification
PubMed: 23666455
DOI: 10.1262/jrd.2013-015 -
SpringerPlus Dec 2013A rapid headspace-gas chromatography (HS-GC) method was developed for the analysis of ethylene glycol and propylene glycol in plasma and serum specimens using...
A rapid headspace-gas chromatography (HS-GC) method was developed for the analysis of ethylene glycol and propylene glycol in plasma and serum specimens using 1,3-propanediol as the internal standard. The method employed a single-step derivitization using phenylboronic acid, was linear to 200 mg/dL and had a lower limit of quantitation of 1 mg/dL suitable for clinical analyses. The analytical method described allows for laboratories with HS-GC instrumentation to analyze ethanol, methanol, isopropanol, ethylene glycol, and propylene glycol on a single instrument with rapid switch-over from alcohols to glycols analysis. In addition to the novel HS-GC method, a retrospective analysis of patient specimens containing ethylene glycol and propylene glycol was also described. A total of 36 patients ingested ethylene glycol, including 3 patients who presented with two separate admissions for ethylene glycol toxicity. Laboratory studies on presentation to hospital for these patients showed both osmolal and anion gap in 13 patients, osmolal but not anion gap in 13 patients, anion but not osmolal gap in 8 patients, and 1 patient with neither an osmolal nor anion gap. Acidosis on arterial blood gas was present in 13 cases. Only one fatality was seen; this was a patient with initial serum ethylene glycol concentration of 1282 mg/dL who died on third day of hospitalization. Propylene glycol was common in patients being managed for toxic ingestions, and was often attributed to iatrogenic administration of propylene glycol-containing medications such as activated charcoal and intravenous lorazepam. In six patients, propylene glycol contributed to an abnormally high osmolal gap. The common presence of propylene glycol in hospitalized patients emphasizes the importance of being able to identify both ethylene glycol and propylene glycol by chromatographic methods.
PubMed: 23741644
DOI: 10.1186/2193-1801-2-203 -
Journal of Hazardous Materials Mar 2023No comparative study has yet been performed on the respiratory effects of individual E-cigarette ingredients. Here, lung toxicity of individual ingredients of...
No comparative study has yet been performed on the respiratory effects of individual E-cigarette ingredients. Here, lung toxicity of individual ingredients of E-cigarette products containing nicotine or tetrahydrocannabinol was investigated. Mice were intratracheally administered propylene glycol (PG), vegetable glycerin (VG), vitamin E acetate (VEA), or nicotine individually for two weeks. Cytological and histological changes were noticed in PG- and VEA-treated mice that exhibited pathophysiological changes which were associated with symptoms seen in patients with symptoms of E-cigarette or Vaping Use-Associated Lung Injuries (EVALI) or E-cigarette users. Compared to potential human exposure situations, while the VEA exposure condition was similar to the dose equivalent of VEA content in E-cigarettes, the PG condition was about 47-137 times higher than the dose equivalent of the daily PG intake of E-cigarette users. These results reveal that VEA exposure is much more likely to cause problems related to EVALI in humans than PG. Transcriptomic analysis revealed that PG exposure was associated with fibrotic lung injury via the AKT signaling pathway and M2 macrophage polarization, and VEA exposure was associated with asthmatic airway inflammation via the mitogen-activated protein kinase signaling pathway. This study provides novel insights into the pathophysiological effects of individual ingredients of E-cigarettes.
Topics: Humans; Mice; Animals; Lung Injury; Vaping; Electronic Nicotine Delivery Systems; Nicotine; Vitamin E; Propylene Glycol; Lung
PubMed: 37055947
DOI: 10.1016/j.jhazmat.2022.130454 -
Pharmaceutical Biology Dec 2017(-)-α-Bisabolol (BISA) is a sesquiterpene alcohol widely used as scent in cosmetic preparations, perfumes, shampoos, toilet soaps and other toiletries with potential... (Comparative Study)
Comparative Study
CONTEXT
(-)-α-Bisabolol (BISA) is a sesquiterpene alcohol widely used as scent in cosmetic preparations, perfumes, shampoos, toilet soaps and other toiletries with potential for use in the pharmaceutical area.
OBJECTIVE
To evaluate the corneal antinociceptive efficacy of BISA and to analyze the best solubilizing agent.
MATERIALS AND METHODS
Acute corneal nociception was induced by the local application of hypertonic saline (5 M NaCl; 20 μL) to the corneal surface of Swiss mice (n = 8/group) 60 min after topical treatment with solutions or ointment containing BISA (50-200 mg/mL). The number of eye wipes performed with the ipsilateral forepaw was counted for a period of 30 s. Control groups (vehicles) were included.
RESULTS
BISA (50, 100 or 200 mg/mL) solubilized with Tween 80 did not reduce the number of eye wipes. Animals treated with the ointment (BISA 50, 100 or 200 mg/mL; p < 0.001), as well the solution containing propylene glycol (BISA 100 mg/mL; p < 0.05), showed significant reduction in the number of nociceptive behaviours. Solutions containing propylene glycol and isopropyl myristate had no effects.
DISCUSSION AND CONCLUSION
BISA possess corneal antinociceptive activity. Although the ointment presented antinociceptive effect, it is concluded that BISA when associated with propylene glycol has better potential for corneal nociceptive pain since it is more comfortable to use, leading to greater acceptance by patients.
Topics: Administration, Ophthalmic; Analgesics; Animals; Behavior, Animal; Cornea; Disease Models, Animal; Drug Compounding; Excipients; Eye Pain; Mice; Monocyclic Sesquiterpenes; Nociceptive Pain; Ointments; Pain Measurement; Propylene Glycol; Saline Solution, Hypertonic; Sesquiterpenes; Solubility
PubMed: 28193100
DOI: 10.1080/13880209.2017.1285944 -
Respiratory Research May 2023Electronic cigarette (Ecig) use has become more common, gaining increasing acceptance as a safer alternative to tobacco smoking. However, the 2019 outbreak of Ecig and...
Electronic cigarette (Ecig) use has become more common, gaining increasing acceptance as a safer alternative to tobacco smoking. However, the 2019 outbreak of Ecig and Vaping-Associated Lung Injury (EVALI) alerted the community to the potential for incorporation of deleterious ingredients such as vitamin E acetate into products without adequate safety testing. Understanding Ecig induced molecular changes in the lung and systemically can provide a path to safety assessment and protect consumers from unsafe formulations. While vitamin E acetate has been largely removed from commercial and illicit products, many Ecig products contain additives that remain largely uncharacterized. In this study, we determined the lung-specific effects as well as systemic immune effects in response to exposure to a common Ecig base, propylene glycol and vegetable glycerin (PGVG), with and without a 1% addition of phytol, a diterpene alcohol that has been found in commercial products. We exposed animals to PGVG with and without phytol and assessed metabolite, lipid, and transcriptional markers in the lung. We found both lung-specific as well as systemic effects in immune parameters, metabolites, and lipids. Phytol drove modest changes in lung function and increased splenic CD4 T cell populations. We also conducted multi-omic data integration to better understand early complex pulmonary responses, highlighting a central enhancement of acetylcholine responses and downregulation of palmitic acid connected with conventional flow cytometric assessments of lung, systemic inflammation, and pulmonary function. Our results demonstrate that Ecig exposure not only leads to changes in pulmonary function but also affects systemic immune and metabolic parameters.
Topics: Animals; Electronic Nicotine Delivery Systems; Multiomics; Lung; Glycerol; Vitamin E; Propylene Glycol; Acetates
PubMed: 37231407
DOI: 10.1186/s12931-023-02441-2