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Meditsinskaia Sestra Aug 1973
Topics: Paraffin
PubMed: 4491435
DOI: No ID Found -
Journal of Visualized Experiments : JoVE Jun 2018Experiments using isolated pancreatic islets are important for diabetes research, but islets are expensive and of limited abundance. Islets contain a mixed cell...
Experiments using isolated pancreatic islets are important for diabetes research, but islets are expensive and of limited abundance. Islets contain a mixed cell population in a structured architecture that impacts function, and human islets are widely variable in cell type composition. Current frequently used methods to study cultured islets include molecular studies performed on whole islets, lumping disparate islet cell types together, or microscopy or molecular studies on dispersed islet cells, disrupting islet architecture. For in vivo islet studies, paraffin-embedded pancreas sectioning is a powerful technique to assess cell-specific outcomes in the native pancreatic environment. Studying post-culture islets by paraffin sectioning would offer several advantages: detection of multiple outcomes on the same islets (potentially even the exact-same islets, using serial sections), cell-type-specific measurements, and maintaining native islet cell-cell and cell-substratum interactions both during experimental exposure and for analysis. However, existing techniques for embedding isolated islets post-culture are inefficient, time consuming, prone to loss of material, and generally produce sections with inadequate islet numbers to be useful for quantifying outcomes. Clinical pathology laboratory cell block preparation facilities are inaccessible and impractical for basic research laboratories. We have developed an improved, simplified bench-top method that generates sections with robust yield and distribution of islets. Fixed islets are resuspended in warm histological agarose gel and pipetted into a flat disc on a standard glass slide, such that the islets are distributed in a plane. After standard dehydration and embedding, multiple (10+) 4 - 5 µm sections can be cut from the same islet block. Using this method, histological and immunofluorescent analyses can be performed on mouse, rat, and human islets. This is an effective, inexpensive, time-saving approach to assess cell-type-specific, intact-architecture outcomes from cultured islets.
Topics: Animals; Histological Techniques; Humans; Islets of Langerhans; Mice; Paraffin; Rats
PubMed: 30010652
DOI: 10.3791/57931 -
Annales de Chirurgie Plastique Et... Apr 2007In 1899, Robert Gersuny, an austrian surgeon from Vienna, injected a mineral oil (vaseline) to correct the absence of a testicle in a patient who was castrated for... (Review)
Review
In 1899, Robert Gersuny, an austrian surgeon from Vienna, injected a mineral oil (vaseline) to correct the absence of a testicle in a patient who was castrated for tuberculous epididymitis. The immediate success of the operation encouraged him to use vaseline as filler for soft tissue defects. The principle of the technique consisted in the injection of a product that becomes semi liquid by heating but it solidifies when it gets colder. It remains stable and inert in the human body. Eckstein used paraffin instead because the melting temperature is too high (65 degrees ) to soften after the injection. The technique provoked enthusiasm. It was used for the cure of palatal and urinary fistulae, hernia but mainly in cosmetic indications: filling of face wrinkles, cheeks, front and breast augmentation as well as the penis and especially nasal defects. Although serious complications were reported, it remained popular for the first 20 years of the 20th century. Unfortunately even with initial good results, secondary or late severe complications appeared due to the dispersion of paraffin. There was formation of nodules, the paraffinomas that were very difficult to remove. The sequelae of paraffin injections were observed for several years.
Topics: Granuloma, Foreign-Body; History, 19th Century; History, 20th Century; Humans; Injections; Paraffin; Surgery, Plastic
PubMed: 16860452
DOI: 10.1016/j.anplas.2006.05.003 -
Environmental Science & Technology Sep 2017Accurate quantification of short-chain chlorinated paraffins (SCCPs) poses an exceptional challenge to analytical chemists. SCCPs are complex mixtures of chlorinated...
Accurate quantification of short-chain chlorinated paraffins (SCCPs) poses an exceptional challenge to analytical chemists. SCCPs are complex mixtures of chlorinated alkanes with variable chain length and chlorination level; congeners with a fixed chain length (n) and number of chlorines (m) are referred to as a "congener group" CCl. Recently, we resolved individual CCl by mathematically deconvolving soft ionization high-resolution mass spectra of SCCP mixtures. Here we extend the method to quantifying CCl by introducing CCl specific response factors (RFs) that are calculated from 17 SCCP chain-length standards with a single carbon chain length and variable chlorination level. The signal pattern of each standard is measured on APCI-QTOF-MS. RFs of each CCl are obtained by pairwise optimization of the normal distribution's fit to the signal patterns of the 17 chain-length standards. The method was verified by quantifying SCCP technical mixtures and spiked environmental samples with accuracies of 82-123% and 76-109%, respectively. The absolute differences between calculated and manufacturer-reported chlorination degrees were -0.9 to 1.0%Cl for SCCP mixtures of 49-71%Cl. The quantification method has been replicated with ECNI magnetic sector MS and ECNI-Q-Orbitrap-MS. CCl concentrations determined with the three instruments were highly correlated (R > 0.90) with each other.
Topics: Environment; Environmental Monitoring; Halogenation; Hydrocarbons, Chlorinated; Paraffin
PubMed: 28813149
DOI: 10.1021/acs.est.7b02269 -
Environment International Dec 2020Chlorinated paraffins (CPs) have been extensively examined to identify their components. Short-chain CPs with a carbon number of 10-13 have been strictly restricted or...
Chlorinated paraffins (CPs) have been extensively examined to identify their components. Short-chain CPs with a carbon number of 10-13 have been strictly restricted or banned due to their addition to the list of Persistent Organic Pollutants in the world. However, more constituents with potential toxicities in these complicated mixtures are still unclear. In the present study, a purification method based on the protein affinity of thyroid hormone-related proteins (transthyretin and thyroid receptor) was established. The protein-based affinity extraction coupled with high-throughput scanning successfully discover a new group of chlorinated compounds (CP(O)) in commercial CP mixtures. The CP(O)s were purified from the commercial mixtures and identified to be chlorinated fatty acid methyl esters (CFAMEs) with a carbon chain length of 17-19 and 3-11 chlorines by a combination of liquid-liquid extraction, hydrolysis, Fourier transform infrared spectrometry and Orbitrap mass spectrometry. The newly identified CFAMEs were found to be ubiquitous in the environmental matrices, and concentration ratios of ∑CFAMEs/∑CPs ranged from 0.01 to 35 in air, soil and food samples. CFAMEs were also detected in blood samples of general populations, and accumulated in humans through dietary uptake. CFAMEs can compete with T4 for binding TTR with higher potencies than CPs, possibly leading to disruptions of thyroid hormone homeostasis.
Topics: Environmental Monitoring; Humans; Hydrocarbons, Chlorinated; Mass Spectrometry; Paraffin; Soil
PubMed: 33053452
DOI: 10.1016/j.envint.2020.106165 -
Journal of Chromatography. A Sep 2022The light condensate fraction obtained from the low temperature Fischer-Tropsch (LT-FT) process is very complex and it is processed further by hydrotreating to produce...
The light condensate fraction obtained from the low temperature Fischer-Tropsch (LT-FT) process is very complex and it is processed further by hydrotreating to produce hydrocarbon products that can be sold as final products. The mass% linear paraffins in some of the final paraffin products is listed as a required specification. Usually gas chromatography equipped with a flame ionisation detector (GC-FID) is used for the analysis of the condensate feeds to estimate the mass% linear paraffins that can be expected in the final products after commercial hydrogenation. This is an important parameter used in the blending of suitable condensate feeds. Due to the complexity of the condensate feeds, significant peak overlap occurs in the GC-FID analysis, making it difficult to accurately estimate the mass% linear paraffin content that will be obtained in the hydrogenated products. Inlet hydrogenation GC-FID analysis simplifies the prediction of the mass% linear content that can be expected in the paraffin product fractions from the analysis of a plant feed since the feed is hydrogenated in the GC inlet before GC-FID analysis. The results from this study showed that sufficient hydrogenation without significant peak tailing can be obtained in the GC inlet when using the appropriate mass and particle size Pd/AlO catalyst with the optimum bed height. Inlet hydrogenation GC-FID analysis simplifies the prediction of the mass% linear content that can be expected in the paraffin product fractions. The method can be implemented on routine GC-FID instrumentation by simply installing an inlet liner containing an appropriate catalyst, that could be re-used at least 20 times, and avoids the purchasing of additional instrumentation and complex data processing and is suitable for commercial process control.
Topics: Bays; Chromatography, Gas; Hydrocarbons; Hydrogenation; Paraffin
PubMed: 36041249
DOI: 10.1016/j.chroma.2022.463441 -
Environmental Science & Technology Feb 2023Herein, we demonstrate the ability of a dual-purpose periodic mesoporous organosilica (PMO) probe to track the complex chlorinated paraffin (CP) composition in living...
Herein, we demonstrate the ability of a dual-purpose periodic mesoporous organosilica (PMO) probe to track the complex chlorinated paraffin (CP) composition in living animals by assembling it as an adsorbent-assisted atmospheric pressure chemical ionization Fourier-transform ion cyclotron resonance mass spectrometry (APCI-FT-ICR-MS) platform and synchronously performing it as the in vivo sampling device. First, synchronous solvent-free ionization and in-source thermal desorption of CP homologues were achieved by the introduction of the PMO adsorbent-assisted APCI module, generating exclusive adduct ions ([M - H]) of individual CP homologues (CCl) with enhanced ionization efficiency. Improved detection limits of short- and medium-chain CPs (0.10-24 and 0.48-5.0 pg/μL) were achieved versus those of the chloride-anion attachment APCI-MS methods. Second, the dual-purpose PMO probe was applied to extract the complex CP compositions in living animals, following APCI-FT-ICR-MS analysis. A modified pattern-deconvolution algorithm coupled with the sampling-rate calibration method was used for the quantification of CPs in living fish. In vivo quantification of a tilapia exposed to technical CPs for 7 days was successfully achieved, with ∑SCCPs and ∑MCCPs of the sampled fish calculated to be 1108 ± 289 and 831 ± 266 μg/kg, respectively. Meanwhile, 58 potential CP metabolites were identified in living fish for the first time during in vivo sampling of CPs, a capacity that could provide an important tool for future study regarding its expected risks to humans and its environmental fate.
Topics: Humans; Animals; Paraffin; Hydrocarbons, Chlorinated; Environmental Monitoring; Mass Spectrometry; Fishes; Chlorides
PubMed: 36790355
DOI: 10.1021/acs.est.2c05923 -
Journal of Hazardous Materials Feb 2023Chlorinated paraffins (CPs), particularly short-chain CPs (SCCPs), have been reported in human blood with high detection frequency and often high variation among...
Chlorinated paraffins (CPs), particularly short-chain CPs (SCCPs), have been reported in human blood with high detection frequency and often high variation among individuals. However, factors associated with and their contributions to inter-individual variability in SCCP concentrations in human blood have not been assessed. In this study, we first measured SCCP concentrations in 57 human blood samples collected from individuals living in the same vicinity in China. We then used the PROduction-To-Exposure model to investigate the impacts of variations in sociodemographic data, biotransformation rates, dietary patterns, and indoor contamination on inter-individual variability in SCCP concentrations in human blood. Measured ∑SCCP concentrations varied by a factor of 10 among individuals with values ranging from 122 to 1230 ng/g, wet weight. Model results show that age, sex, body weight, and dietary composition played a minor role in causing variability in ∑SCCP concentrations in human blood given that modeled ∑SCCP concentrations ranged over a factor of 2 - 3 correlated to the variations of these factors. In contrast, variations in the modeled ΣSCCP concentrations increased to factors of 6 and 8 when variability in biotransformation rates and indoor contamination were considered, respectively, indicating these two factors could be the most influential on inter-individual variability in SCCP concentrations in human blood.
Topics: Humans; Paraffin; Hydrocarbons, Chlorinated; Environmental Monitoring; China
PubMed: 36368064
DOI: 10.1016/j.jhazmat.2022.130235 -
Environmental Pollution (Barking, Essex... Sep 2023In this study, very short-, short-, medium-, and long-chain chlorinated paraffins (vSCCPs, SCCPs, MCCPs and LCCPs, respectively) were measured in 40 indoor dust samples...
In this study, very short-, short-, medium-, and long-chain chlorinated paraffins (vSCCPs, SCCPs, MCCPs and LCCPs, respectively) were measured in 40 indoor dust samples from four countries including Japan (n = 10), Australia (n = 10), Colombia (n = 10) and Thailand (n = 10). Homologues of the chemical formula CHCl ranging C and Cl were analysed using liquid chromatography coupled to Orbitrap high resolution mass spectrometry (LC-Orbitrap-HRMS) and integrated using novel custom-built CP-Seeker software. CPs were detected in all dust samples with MCCPs the dominant homologue group in all countries. Overall median ∑SCCP, ∑MCCP and ∑LCCP (C) concentrations determined in dust samples were 30 μg/g (range; 4.0-290 μg/g), 65 μg/g (range; 6.9-540 μg/g) and 8.6 μg/g (range; <1.0-230 μg/g), respectively. Of the quantified CP classes, overall concentrations were generally highest in the samples from Thailand and Colombia, followed by Australia and Japan. vSCCPs with C were detected in dust from each country with an overall frequency of 48%, while LCCPs (C) were present in 100% of samples. Estimated daily intakes (EDIs) calculated for SCCPs and MCCPs relating to ingestion of contaminated indoor dust were considered not to represent health risks based on currently available toxicological data using the margin of exposure (MOE) approach. To the authors' knowledge, this study provides the first data on CPs in indoor dust from Japan, Colombia and Thailand, and is among the first reports of vSCCPs in indoor dust, globally. These findings indicate that further toxicological data and the availability of appropriate analytical standards are needed to evaluate the potential for negative health outcomes deriving from exposure to vSCCPs and LCCPs.
Topics: Environmental Monitoring; Hydrocarbons, Chlorinated; Paraffin; Dust; Mass Spectrometry; China
PubMed: 37302785
DOI: 10.1016/j.envpol.2023.121994 -
Environmental Science & Technology Dec 2022Determining the major human exposure pathways is a prerequisite for the development of effective management strategies for environmental pollutants such as chlorinated...
Determining the major human exposure pathways is a prerequisite for the development of effective management strategies for environmental pollutants such as chlorinated paraffins (CPs). As a first step, the internal and external exposure to CPs were quantified for a well-defined human cohort. CPs in participants' plasma and diet samples were analyzed in the present study, and previous results on paired air, dust, and hand wipe samples were used for the total exposure assessment. Both one compartment pharmacokinetic modeling and forensic fingerprinting indicate that dietary intake contributed the most to body burden of CPs in this cohort, contributing a median of 60-88% of the total daily intakes. The contribution from dust ingestion and dermal exposure was greater for the intake of long-chain CPs (LCCPs) than short-chain CPs (SCCPs), while the contribution from inhalation was greater for the intake of SCCPs than medium-chain CPs (MCCPs) and LCCPs. Significantly higher concentrations of SCCPs and MCCPs were observed in diets containing butter and eggs, respectively ( < 0.05). Additionally, other exposure sources were correlated to plasma levels of CPs, including residence construction parameters such as the construction year ( < 0.05). This human exposure to CPs is not a local case. From a global perspective, there are major knowledge gaps in biomonitoring and exposure data for CPs from regions other than China and European countries.
Topics: Humans; Paraffin; Hydrocarbons, Chlorinated; Body Burden; Environmental Monitoring; Dust; Eating; China
PubMed: 36378808
DOI: 10.1021/acs.est.2c04998