14 research outputs found
Математическое моделирование загрязнения нефтепродуктами в водной среде
In this review, we discuss and compare studies of xenobiotic metabolism in both human skin and 3D human skin reconstructs. In comparison to the liver, the skin is a less studied organ in terms of characterising metabolic capability. While the skin forms the major protective barrier to environmental chemical exposure, it is also a potential target organ for adverse health effects. Occupational, accidental or intended-use exposure to toxic chemicals could result in acute or delayed injury to the skin (e.g. inflammation, allergy, cancer). Skin metabolism may play a role in the manifestation or amelioration of adverse effects via the topical route. Today, we have robust testing strategies to assess the potential for local skin toxicity of chemical exposure. Such methods (e.g. the local lymph node assay for assessing skin sensitisation; skin painting carcinogenicity studies) incorporate skin metabolism implicitly in the in vivo model system used. In light of recent European legislation (i.e. 7th Amendment to the Cosmetics Directive and Registration Evaluation and Authorisation of existing Chemicals (REACH)), non-animal approaches will be required to reduce and replace animal experiments for chemical risk assessment. It is expected that new models and approaches will need to account for skin metabolism explicitly, as the mechanisms of adverse effects in the skin are deconvoluted. 3D skin models have been proposed as a tool to use in new in vitro alternative approaches. In order to be able to use 3D skin models in this context, we need to understand their metabolic competency in relation to xenobiotic biotransformation and whether functional activity is representative of that seen in human skin
Performance of non-invasive tests and histology for the prediction of clinical outcomes in patients with non-alcoholic fatty liver disease: an individual participant data meta-analysis
BackgroundHistologically assessed liver fibrosis stage has prognostic significance in patients with non-alcoholic fatty liver disease (NAFLD) and is accepted as a surrogate endpoint in clinical trials for non-cirrhotic NAFLD. Our aim was to compare the prognostic performance of non-invasive tests with liver histology in patients with NAFLD.MethodsThis was an individual participant data meta-analysis of the prognostic performance of histologically assessed fibrosis stage (F0–4), liver stiffness measured by vibration-controlled transient elastography (LSM-VCTE), fibrosis-4 index (FIB-4), and NAFLD fibrosis score (NFS) in patients with NAFLD. The literature was searched for a previously published systematic review on the diagnostic accuracy of imaging and simple non-invasive tests and updated to Jan 12, 2022 for this study. Studies were identified through PubMed/MEDLINE, EMBASE, and CENTRAL, and authors were contacted for individual participant data, including outcome data, with a minimum of 12 months of follow-up. The primary outcome was a composite endpoint of all-cause mortality, hepatocellular carcinoma, liver transplantation, or cirrhosis complications (ie, ascites, variceal bleeding, hepatic encephalopathy, or progression to a MELD score ≥15). We calculated aggregated survival curves for trichotomised groups and compared them using stratified log-rank tests (histology: F0–2 vs F3 vs F4; LSM: 2·67; NFS: 0·676), calculated areas under the time-dependent receiver operating characteristic curves (tAUC), and performed Cox proportional-hazards regression to adjust for confounding. This study was registered with PROSPERO, CRD42022312226.FindingsOf 65 eligible studies, we included data on 2518 patients with biopsy-proven NAFLD from 25 studies (1126 [44·7%] were female, median age was 54 years [IQR 44–63), and 1161 [46·1%] had type 2 diabetes). After a median follow-up of 57 months [IQR 33–91], the composite endpoint was observed in 145 (5·8%) patients. Stratified log-rank tests showed significant differences between the trichotomised patient groups (p<0·0001 for all comparisons). The tAUC at 5 years were 0·72 (95% CI 0·62–0·81) for histology, 0·76 (0·70–0·83) for LSM-VCTE, 0·74 (0·64–0·82) for FIB-4, and 0·70 (0·63–0·80) for NFS. All index tests were significant predictors of the primary outcome after adjustment for confounders in the Cox regression.InterpretationSimple non-invasive tests performed as well as histologically assessed fibrosis in predicting clinical outcomes in patients with NAFLD and could be considered as alternatives to liver biopsy in some cases
Interactions of skin thickness and physicochemical properties of test compounds in percutaneous penetration studies
Objectives: To determine the effect of skin thickness on the percutaneous penetration and distribution of test compounds with varying physicochemical properties using in vitro systems. Studies were carried out in accordance with OECD guidelines on skin absorption tests. Methods: Percutaneous penetration of caffeine (log P -0.01), testosterone (log P 3.32), propoxur (log P 1.52) (finite dose in ethanol to water vehicle ratio) and butoxyethanol (log P 0.83) (undiluted finite dose or as an infinite dose 50% [v/v] aqueous solution) through skin of varying thicknesses under occluded conditions was measured using flow through cells for 8-24 h. Saline (adjusted to pH 7.4) was used as receptor fluid, with BSA added for studies with testosterone and propoxur. Following exposure, the remaining surface dose was removed by swabbing and the skin digested prior to scintillation counting. Results: The maximum flux of caffeine was increased with decreasing skin thickness, although these differences were found to be non-significant. The presence of caffeine in the skin membrane was not altered by skin thickness. Maximum flux and cumulative dose absorbed of testosterone and butoxyethanol (in both finite and infinite doses) were markedly reduced with full thickness (about 1 mm thick) skin compared with split thickness skin (about 0.5 mm). Maximum flux of propoxur (dissolved in 60% ethanol) was clearly higher through skin of 0.71 mm than through skin of 1.36 mm, but no difference was found between 0.56 and 0.71 mm. The proportion of propoxur present in the membrane after 24 h increased significantly over the complete range of thicknesses tested (0.56-1.36 mm). Conclusions: A complex relationship exists between skin thickness, lipophilicity and percutaneous penetration and distribution. This has implications for risk assessment studies and for the validation of models with data from different sources. © Springer-Verlag 2006
Interactions of skin thickness and physicochemical properties of test compounds in percutaneous penetration studies
The Use of In Vitro Toxicity Data and Physiologically Based Kinetic Modeling to Predict Dose-Response Curves for In Vivo Developmental Toxicity of Glycol Ethers in Rat and Man
Three-tiered score for Ki-67 and p16 improves accuracy and reproducibility of grading CIN lesions
AIMS: To investigate the accuracy and reproducibility of a scoring system for cervical intraepithelial neoplasia (CIN1-3) based on immunohistochemical (IHC) biomarkers Ki-67 and p16ink4a. METHODS: 115 cervical tissue specimens were reviewed by three expert gynaecopathologists and graded according to three strategies: (1) CIN grade based on H&E staining only; (2) immunoscore based on the cumulative score of Ki-67 and p16ink4a only (0-6); and (3) CIN grade based on H&E supported by non-objectified IHC 2 weeks after scoring 1 and 2. The majority consensus diagnosis of the CIN grade based on H&E supported by IHC was used as the Reference Standard. The proportion of test positives (accuracy) and the absolute agreements across pathologists (reproducibility) of the three grading strategies within each Reference Standard category were calculated. RESULTS: We found that immunoscoring with positivity definition 6 yielded the highest proportion of test positives for Reference Standard CIN3 (95.5%), in combination with the lowest proportion of test positives in samples with CIN1 (1.8%). The proportion of test positives for CIN3 was significantly lower for sole H&E staining (81.8%) or combined H&E and IHC grading (84.8%) with positivity definition ≥CIN3. Immunoscore 6 also yielded high absolute agreements for CIN3 and CIN1, but the absolute agreement was low for CIN2. CONCLUSIONS: The higher accuracy and reproducibility of the immunoscore opens the possibility of a more standardised and reproducible definition of CIN grade than conventional pathology practice, allowing a more accurate comparison of CIN-based management strategies and evaluation of new biomarkers to improve the understanding of progression of precancer from human papillomavirus infection to cancer
The Use of Biokinetics and In Vitro Methods in Toxicological Risk Evaluation: The Report and Recommendations of ECVAM Workshop 15
HPV E4 expression and DNA hypermethylation of CADM1, MAL, and miR124-2 genes in cervical cancer and precursor lesions
In this study, we evaluate the expression of human papillomavirus E4 protein (marker for the onset of a productive infection) and hypermethylation of host-cell CADM1, MAL, and miR124-2 genes (marker for an advanced, transforming infection) in cervical intraepithelial neoplasia (CIN) and cancer. A total of 115 cervical lesions were categorized by 3 pathologists into no dysplasia, CIN1, CIN2, CIN3, or cancer by classical histomorphological grading criteria, and by an immunoscore (cumulative value: 0-6) grading system based on Ki-67 (score: 0-3) and p16ink4a (score: 0-3) expression. Lesions were immunostained for E4 protein and analyzed for hypermethylation of CADM1, MAL, or miR124-2 genes. Expression of E4 and hypermethylation levels were related to CIN grade based on both classical and immunoscore grading. Hypermethylation increased with severity of the lesion as defined by both classical histomorphological grading and immunoscore criteria, and was always present in carcinomas (22/22). Extensive E4 expression decreased with increasing CIN grade and immunoscore, being most frequent in classically graded CIN1 or in lesions with cumulative immunoscore 1-3 and absent in carcinomas. High-grade lesions (CIN2/3 or immunoscore: 4-6) showed less E4 expression, which was inversely related to an increasing hypermethylation. Extensive E4 expression, as observed in a small proportion of high-grade lesions (6/49 and 8/43, respectively), was mostly associated with a negative methylation marker status (5/6 and 7/8, respectively). Our results illustrate the gradual transition of productive CIN (reflected by extensive E4 expression), to advanced transforming CIN (reflected by extensive hypermethylation) and cancer. Expression patterns of E4 and hypermethylation status of host-cell genes, may be used to identify cervical lesions at risk for cervical cancer, providing a better guidance for clinicians on treatment decisions