Micronuclei In Lymphocytes Research Articles

Influencing factors of occupational health of clinical nuclear medical staff

Objective: To analyze the characteristics and its influencing factors of occupational injury among clinical nuclear medicine staff, and to put forward suggestions for formulating relevant radiation protection intervention measures. Methods: In March 2022, a study was conducted involving 12 medical institutions engaged in nuclear medicine in Gansu Province. The occupational health examination data of 1451 clinical nuclear medicine staff were analyzed. The study subjects were divided into two groups based on the median annual effective dose of external exposure in 2022: Group A (annual effective dose ≤0.2 mSv, n=927) and group B (annual effective dose >0.2 mSv, n=524). The effects of annual effective dose, age, seniority, gender and occupational category on occupational health of clinical nuclear medicine staff were analyzed. Classification variables between groups were compared with Pearson χ(2) test. Multivariate logistic regression was used to analyze the influencing factors of the abnormal results. Results: The abnormal rates of white blood cell count (WBC), red blood cell count (RBC) and hemoglobin (HGB) in female clinical nuclear medical staff were higher than those in males, and the differences were statistically significant (P<0.001). The abnormal rates of WBC and HGB in clinical nuclear medicine staff of different occupational categories were statistically significant (P<0.05). The abnormal rates of RBC and HGB of clinical nuclear medicine staff in annual effective dose group B were higher than those in group A, and the differences were statistically significant (P<0.05). Multivariate logistic regression results showed that the abnormal risks of RBC in annual effective dose group B was 2.465 times of that in group A, the abnormal risks of RBC, WBC and HGB in females were 9.354, 2.939 and 6.760 times of those in males, respectively. The abnormal risk of WBC in the radiotherapy group was 2.334 times of that in general radiotherapy group. The abnormal risk of lens in nuclear medicine group was 2.459 times of that in general radiotherapy group. The abnormal risk of ECG and lens in ≥35 years old age group were 1.814 times and 1.969 times of those in <35 years old age group, respectively. The abnormal risk of lens of the ≥10 working years group was 1.899 times of that in the <10 working years group. The risk of lymphocyte micronucleus abnormality in the interventional group was 1.481 times of that in the general radiotherapy group, the risk of lymphocyte micronucleus abnormality in females was 2.215 times of that in males. The risk of lymphocyte micronucleus abnormality and lymphocyte chromosome aberration in ≥35 years old age group were 2.552 and 2.266 times of those in <35 years old age group, respectively. The risk of lymphocyte micronucleus abnormality in the group with≥10 working years was 1.443 times of that in<10 working years group (P<0.05) . Conclusion: Long-term low-dose ionizing radiation has a certain effect on the lens and genetic indexes of clinical nuclear medicine staff.

Study of Radiosensitivity and Induction of Radiation Adaptive Response in Peripheral Blood Lymphocytes of Patients with Oncological Diseases Using the Micronuclear Test.

Radiosensitivity to low and medium doses of X-ray radiation and the ability to induce a radiation adaptive response (RAR) of lymphocytes during in vitro irradiation of peripheral blood of patients with cancer were studied. The criterion for cytogenetic damage was the frequency of micronuclei (MN) in cytochalasin-blocked binucleate lymphocytes in culture. It was found that the spontaneous level of cytogenetic damage in the lymphocytes of patients was 2.6 times higher than in healthy volunteers, and there was also significant interindividual variability in values compared to the control cohort. There were no differences in mean values for radiosensitivity to low and medium doses of X-ray between the study groups. There was no correlation between the spontaneous level of MN in lymphocytes and the radiosensitivity of individuals in both groups. RAR was induced with the same frequency and to the same extent in lymphocytes from both patients and healthy individuals.

Health risks of rare earth elements exposure: Impact on mitochondrial DNA copy number and micronucleus frequency

Toxic effects in terms of mitochondria and hereditary substances have been characterized in vitro for individual rare earth elements, while, the joint effects of mixed elements exposure in the population remain ambiguous. Based on the Occupational Chromate Exposure Dynamic Cohort of China, this study investigated the relationship between 15 blood rare earth elements (cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, samarium, terbium, thulium, yttrium, and ytterbium) and mitochondrial DNA copy number (MtDNACN) as well as peripheral blood lymphocyte micronucleus frequency (MNF). The elastic net was used to select elements highly correlated with effect indicators, whose dose-response relationships were further illustrated by restricted cubic splines. Bayesian kernel regression was employed to explore the combined effects of elements and the contributions of single element. The results showed that most rare earth elements were positively correlated with effect indicators, with yttrium showing the strongest association (β (95% CI): 0.139 (0.1089 – 0.189) for MtDNACN, 0.937 (0.345 – 1.684) for MNF). In the mixed exposure model, with the exposure level fixed at the 50th percentile as the reference, the effect estimates on MtDNACN and MNF increased by 0.228 and 0.598 units, respectively, at the 75th percentile. The single effect analysis implied that yttrium, lanthanum and terbium contributed the most to the elevation of MtDNACN, while yttrium posed the highest risk for genetic damage, accordingly, we provided recommendations to prioritize these elements of concern. In addition, we observed a chief mediating effect of MtDNACN on the elevation of MNF caused by lanthanum, whereas further mechanistic exploration is required to confirm this finding.

LASU: An efficient and stable phthalocyanine dye with tolerable safety profile for self-disinfecting anti-COVID textiles activated by ambient light

BackgroundRecent COVID crisis has demonstrated that modern society urgently needs an accessible protection against mass infections, especially viruses, as the new strains are appearing at an ever-increasing pace and cause severe harm to the population and the world economy. MethodsWe have developed an efficient phthalocyanine photosensitizer LASU, that is suitable for dyeing textiles and allows to prepare reusable self-disinfecting fabrics with strong antiviral properties. The safety profile of LASU was evaluated in accredited laboratories by several in vitro assays according to the OECD-guidelines. ResultsThe textiles impregnated with LASU phthalocyanine showed a significant antiviral photodynamic effect even under moderate indoor and outdoor light. The dye did not show any genotoxic potential in human lymphocyte micronucleus assay. It showed a possible indication for eye irritation in human EpiOcular™ model and was phototoxic when tested in mouse BALB/c 3T3 cell test in the presence and absence of UVA-irradiation. ConclusionNovel phthalocyanine-dyed textiles are suitable for general use as self-disinfecting antiviral barriers and materials in hospitals, households, and public places. The safety profile of LASU is the phototoxic effect which is related to LASU´s mode of action.

Genoprotective role of pembrolizumab liposome in isolated lymphocytes from head and neck squamous cell carcinoma patients compared to those from healthy individuals in vitro

Pembrolizumab has shown significant anticancer effects against various human cancers. The present study investigated the effects of pembrolizumab liposome and nano (naked) forms in treated lymphocytes from head and neck squamous cell carcinoma (HNSCC) patients compared to healthy individuals. The level of oxidative DNA damage induced by hydrogen peroxide (H2O2) was also investigated. A concentration of 10 µg/ml of pembrolizumab liposome was used to treat the lymphocytes in the Comet and micronucleus assays based on the preliminary dosage optimization tests. To determine the cellular pathways involved in the protective role of pembrolizumab against H2O2, several proteins involved in apoptosis (P53, P21 and Bcl-2) were assessed. Pembrolizumab significantly reduced DNA damage and decreased the number of micronuclei in lymphocytes from HNSCC patients (p < 0.01) compared with healthy individuals. The 10 µg/ml of pembrolizumab liposome significantly reduced the oxidative stress induced by H2O2 and was effective in healthy and HNSCC groups using the Comet and micronucleus assays (p < 0.001). To our knowledge, this is the first report of pembrolizumab in liposome and naked forms exhibiting a protective effect on DNA damage in the treatment of HNSCC patients.

Research on radiation sensitive biomarkers and status of radiation safety literacy under low dose irradiation: Radiation biomarkers and radiation safety culture

ObjectiveTo analyze the health status and radiation sensitivity index of radiation workers in provincial, county and township hospitals. To explore the methods of evaluation indicators, evaluation standards and scoring principles of radiation safety culture in medical institutions. MethodsIn 2021, the radiation safety status of all 172 medical institutions in a city was investigated by using retrospective investigation, current situation investigation and laboratory study. The occupational health monitoring data of all 1547 radiation workers were statistically analyzed, and the radiation safety status and health indicators of radiation workers in provincial, county and township level hospitals were compared. ResultsThe results of occupational health monitoring of radiation workers showed that there were statistically significant differences in ALT, lens opacity (P < 0.05) and lymphocyte micronucleus (P < 0.05) between the two groups, and there were statistically significant differences in the influence of radiation service on the detection rate of lens opacity (P < 0.05). The survey results of radiation safety culture construction in medical institutions show that there are differences in the level of radiation safety culture in hospitals of different grades. The radiation safety culture construction of provincial and municipal public hospitals is obviously better than that of county hospitals, especially township hospitals. ConclusionInterventional radiologists and nuclear medicine workers engaged in iodine therapy were exposed to higher radiation agents, and radiation workers in township health centers were not aware of radiation protection, and there was a certain occupational risk. At the same time, the evaluation index of radiation safety literacy in medical institutions was determined, Disease prevention and control personnel stationed in hospitals is an effective measure to strengthen the construction of radiation safety culture in hospitals.

Cladonia rangiformis Acetone Extract— New Insight into the Chemical Composition and Biological Activity

Introduction Cladonia rangiformis, also known as reindeer lichen, has been used for various remedies in folk medicine. The rich nutritional value of this lichen is reflected in the fact that it contains atranorin, which has been proven to have numerous biological activities. Objective The chemical composition, antioxidant, anticholinesterase, and antigenotoxic activities of the C. rangiformis acetone extract were investigated. The novelty of this work is that anticholinesterase activity, protective effect on human lymphocytes, and antioxidant activity by the cupric-reducing antioxidant capacity (CUPRAC) method of C. rangiformis extract were determined for the first time, as well as gas chromatography - mass spectrometry (GC-MS) profile. Methods Chemical composition was carried out by high-performance liquid chromatography (HPLC)-diode array detector and GC-MS. Antigenotoxic effect was evaluated in human lymphocytes by cytokinesis-block micronucleus assay. Total phenolic content, DPPH and ABTS radical scavenging capacities, CUPRAC, and total reducing power were determined spectrophotometrically. Determination of acetylcholinesterase activity was performed by Ellman's colorimetry assay. The statistical analysis of variance (One-way ANOVA) was performed using Origin software package version 7.0. Results HPLC method was used to identified 3 compounds with atranorin as predominant constituent (97.2%). Fumarprotocetraric and atraric acid were represented in a much smaller mutually approximate amount, 0.3 and 0.5%, respectively. Rangiformic acid was the most abundant volatile compound. Acetone extract of C. rangiformis (2 μg/mL) decreased the frequency of micronuclei by 15.5% while the radioprotectant amifostine reduced the frequency of occurrence of micronuclei by 11.4%. On the contrary, at a concentration of 1.0 mg/mL the extract exhibited an activating effect on cholinesterase (2.0%), while at a concentration of 10.0 mg/mL it showed a weak inhibitory effect (7.3%). The total phenol content was 132.71 μg gallic acid equivalents per mg of dry extract. The IC50 value for the DPPH experiment was 16.19 mg/mL and for ABTS was 11.80 mg/mL. Cupric reducing capacity and total reducing power were 17.81 μg Trolox equivalents per mg of dry extract and 0.45 μg ascorbic acid equivalents per mg of dry extract, respectively. Conclusion In addition to previously identified compounds in the acetone extract, atraric acid was identified for the first time by using HPLC method, and orcinol, β-orcinol, lauric alcohol, atranol, and rangiformic acid by using GC-MS method. The results of biological activity proved that acetone extract had antioxidant capacity and weak anticholinesterase activity. Reduction of the number of micronuclei in human lymphocytes, classified C. rangiformis as promising substances source with beneficial effects on DNA damage.

Analysis of whole blood cells and genetic influencing factors in medical radiation workers

Objective: To explore the influencing factors of whole blood cells and genetics of medical radiation workers, and provide technical support for improving occupational health management and strengthening radiation protection. Methods: In January 2022, a total of 4180 medical radiation workers who underwent occupational health examination in Gansu Provincial Center for Disease Control and Prevention from January 2020 to December 2021 were collected as the research objects, and the results of demographic characteristics, whole blood cells, chromosome aberrations, lymphocyte micronucleus and other results were collected. The whole blood cells and genetic abnormalities of different demographic characteristics of medical radiation workers were compared. And the influencing factors of whole blood cells and genetic abnormalities were analyzed by multivariate logistic regression. Results: The rates of hemoglobin (HGB), chromosome aberration and lymphocyte micronucleus abnormality were the highest in the nuclear medicine group, and the rate of white blood cell (WBC) abnormality in the radiotherapy group was higher than those in other occupational groups, the differences were statistically significant (P<0.05). The abnormal rates of WBC, HGB and lymphocyte micronucleus in female radiation workers were significantly higher than those in male radiation workers (P<0.001). The abnormal rates of HGB and lymphocyte micronucleus were statistically different among different working years and different age radiation workers (P<0.001). And the abnormal rate of platelet (PLT) was statistically different among different working years radiation workers (P<0.05). The abnormal rate of HGB in radiation workers of different hospital levels was statistically different (P<0.001). Logistic regression analysis showed that the risk of abnormal WBC and HGB in females radiation workers were 3.048 times and 13.122 times of those in males, respectively (P<0.001). The abnormal risks of WBC in the 6-20 working years group and >20 working years group were 1.517 times and 1.874 times of that in the ≤5 working years group, respectively (P<0.05). The abnormal risk of PLT in the >20 working years group was 2.643 times of that in ≤5 working years group (P<0.05). The abnormal risk of WBC in radiotherapy group and intervention group were 2.407 times and 1.341 times of that in general radiotherapy group, respectively (P<0.05) . Conclusion: Ionizing radiation has different effects on the whole blood cells and genetic indexes of workers in the nuclear medicine, interventional group and radiotherapy group. The occupational health protection of female radiation workers should be paid attention to.

A study on the radiosensitivity and induction of adaptive response in peripheral blood lymphocytes of patients with secondary immunodeficiency syndrome

This study examined radiosensitivity at low and high dose exposure to X-rays in human lymphocytes and the ability of low and high dose radiation to induce radioadaptive response when the peripheral blood cells from patients with secondary immune deficiency syndrome and healthy donors of different ages were irradiated in vitro. The frequency of micronuclei in cytochalasin-blocked binuclear lymphocytes in culture served as an indication of cytogenetic damage. It was found that the spontaneous level of cytogenetic damage in blood lymphocytes of patients with secondary immune deficiency syndrome was 2.5 times greater than that of healthy young and older volunteers and there was also a substantial interindividual variability in outcome parameters as compared to the data of control groups. There were no differences in mean values for radiosensitivity at low and high dose exposure of X-rays between the groups. In all groups, no correlation was shown between the spontaneous level of micronuclei in lymphocytes and the radiosensitivity of individuals. The adaptive response was induced with the same frequency and to the same extent in lymphocytes in patients with secondary immune deficiency syndrome and in healthy donors of different ages.

Establishment of ex vivo calibration curve for X-ray induced “dicentric + ring” and micronuclei in human peripheral lymphocytes for biodosimetry during radiological emergencies, and validation with dose blinded samples

In the modern developing society, application of radiation has increased extensively. With significant improvement in the radiation protection practices, exposure to human could be minimized substantially, but cannot be avoided completely. Assessment of exposure is essential for regulatory decision and medical management as applicable. Until now, cytogenetic changes have served as surrogate marker of radiation exposure and have been extensively employed for biological dose estimation of various planned and unplanned exposures. Dicentric Chromosomal Aberration (DCA) is radiation specific and is considered as gold standard, micronucleus is not very specific to radiation and is considered as an alternative method for biodosimetry. In this study dose response curves were generated for X-ray induced “dicentric + ring” and micronuclei, in lymphocytes of three healthy volunteers [2 females (age 22, 23 years) and 1 male (24 year)]. The blood samples were irradiated with X-ray using LINAC (energy 6 MV, dose rate 6 Gy/min), in the dose range of 0–5Gy. Irradiated blood samples were cultured and processed to harvest metaphases, as per standard procedures recommended by International Atomic Energy Agency. Pooled data obtained from all the three volunteers, were in agreement with Poisson distribution for “dicentric + ring”, however over dispersion was observed for micronuclei. Data (“dicentric + ring” and micronuclei) were fitted by linear quadratic model of the expression YC + αD + βD2 using Dose Estimate software, version 5.2. The data fit has resulted in linear coefficient α = 0.0006 (±0.0068) “dicentric + ring” cell−1 Gy−1 and quadratic coefficient β = 0.0619 (±0.0043) “dicentric + ring” cell−1 Gy−2 for “dicentric + ring” and linear coefficient α = 0.0459 ± (0.0038) micronuclei cell−1 Gy−1 and quadratic coefficient β = 0.0185 ± (0.0010) micronuclei cell−1 Gy−2 for micronuclei, respectively. Background frequencies for “dicentric + ring” and micronuclei were 0.0006 ± 0.0004 and 0.0077 ± 0.0012 cell−1, respectively. Established curves were validated, by reconstructing the doses of 8 dose blinded samples (4 by DCA and 4 by CBMN) using coefficients generated here. Estimated doses were within the variation of 0.9–16% for “dicentric + ring” and 21.7–31.2% for micronuclei respectively. These established curves have potential to be employed for biodosimetry of occupational, clinical and accidental exposures, for initial triage and medical management.

Dry tobacco leaves: an in vivo and in silico approach to the consequences of occupational exposure.

Exposure of tobacco workers handling dried tobacco leaves has been linked to an increased risk of toxicity and respiratory illness due to the presence of nicotine and other chemicals. This study aimed to evaluate the DNA damage caused by the exposure of tobacco growers during the dry leaf classification process and the relation to cellular mechanisms. A total of 86 individuals participated in the study, divided into a group exposed to dry tobacco (n = 44) and a control group (n = 42). Genotoxicity was evaluated using the alkaline comet assay and lymphocyte micronucleus (MN) assay (CBMN-Cyt), and measurement of telomere length. The levels of oxidative and nitrosative stress were evaluated through the formation of thiobarbituric acid reactive species, and nitric oxide levels, respectively. The inorganic elements were measured in the samples using particle-induced X-ray emission method. The combination of variables was demonstrated through principal component analysis and the interactions were expanded through systems biology. Comet assay, MN, death cells, thiobarbituric acid reactive species, and nitrosative stress showed a significant increase for all exposed groups in relation to the control. Telomere length showed a significant decrease for exposed women and total exposed group in relation to men and control groups, respectively. Bromine (Br) and rubidium (Rb) in the exposed group presented higher levels than control groups. Correlations between nitrate and apoptosis; Br and MN and necrosis; and Rb and telomeres; besides age and DNA damage and death cells were observed. The systems biology analysis demonstrated that tobacco elements can increase the nuclear translocation of NFKB dimers inducing HDAC2 expression, which, associated with BRCA1 protein, can potentially repress transcription of genes that promote DNA repair. Dry tobacco workers exposed to dry leaves and their different agents showed DNA damage by different mechanisms, including redox imbalance.

Comprehensive Analysis of the Herbal Mixture Made of Juniperus oxycedrus L. Berries, Inner Bark of Betula pendula Roth., and Grains of Avena sativa L.

This is the first report of the high-performance liquid chromatography and gas chromatography–mass spectrometry profile of a herbal mixture (HM) made of Juniperus oxycedrus L. (redberry juniper) berries, inner bark of Betula pendula Roth. (silver birch), and grains of Avena sativa L. (oat), and its effect on the No. of micronuclei (MN) in human lymphocytes and toxicity toward Artemia salina. Constituents represented by over 1000 µg per g of methanol dry extract were gallic acid, protocatechuic acid, and amentoflavone. The methanol extract of the HM at a concentration of 2.0 μg/mL decreased MN frequency by 38.3%, which was more than 3 times greater than that of the radioprotectant amifostine. The essential oil isolated from the HM was composed mainly of β-myrcene (32%) and showed weaker toxicity toward Artemia salina than the positive control after both incubation periods (24 h and 48 h). These findings suggest that the examined HM, beside its ethnopharmacological relevance on the elimination of renal calculi, also significantly reduces the No. of MN in human lymphocytes.

Study on the genetic damage caused by cadmium sulfide quantum dots in human lymphocytes.

Cadmium sulfide quantum dots (CdS QDs) are being developed for sensors, fluorescent probes, and other platforms and are attracting increasing attention. Given the growing demand for QDs, it is clear that there is a need to understand their potential toxicity to organisms. However, little is known regarding the genotoxicity of CdS QDs to humans. Therefore, this study used CdS QDs as the research object, cultured human peripheral blood lymphocytes, and randomly divided them into a control group, CdS I group (CdS QDs), and CdS II group (CdS QDs coated with thioglycolic acid). After cultivation, we measured the olive tail distance, tail length, tail DNA%, lymphocyte micronucleus rate, and aneuploid rate. The comet test results indicated that the indices of the QD group were significantly larger than those of the control group (P < 0.05). The results of the micronucleus and chromosome aberration tests showed that the lymphocyte micronucleus rate and chromosome aneuploid rate in the QD group were significantly increased (P < 0.05) compared with those in the control group. In conclusion, CdS QDs have certain genotoxicity to human peripheral blood lymphocytes, and the DNA damage caused by CdS QDs encapsulated with thioglycolic acid is less severe than that caused by nonencapsulated CdS QDs.

Factors Affecting the Nuclei in Newborn and Children.

It is known that children are more sensitive to the effects of medical treatments and environment than adults. Today there is limited information regarding the differences in genotoxic effects in children. The micronucleus assay is a method that is used to monitor genotoxicity, and it was validated several years before. Today there is international interest for exfoliated buccal cells. Most of the micronuclei studies in children have been performed with the analyses of lymphocytes. However, there is vast interest in using exfoliated cells from the oral cavity. The reason is that other type of cells are acquired non-invasively, this is an important issue in paediatric cohorts. Unfortunately a limitation of measuring micronuclei frequency is that it has been observed to be low in newborns and on the other hand there are a large number of patients and cell sample counts. It has been observed that radiation exposure and environmental pollutants increase the micronuclei frequency in newborn and children. Regarding the medical treatments, there is little data and several studies are needed to optimise the doses. There is the need to observe if there is a relationship between micronuclei in lymphocytes and exfoliated cells and to identify the baseline of the micronuclei levels. Moreover, we evaluate the changes in response to the toxic agents. Prospective cohorts studies will clarify the predictive value of micronuclei for cancer and chronic diseases for both children and adults. Novel molecular technologies will assist in the elucidation of different biological pathways and molecular mechanisms connected with the micronulcei levels in newborn and children.

Assessment of the in vitro effect of intra and extracellular extracts of Lactobacillus against genotoxicity and oxidative stress caused by acrylamide

Introduction: acrylamide is formed by the Maillard reaction and is found in many food products subjected to thermal processes, generating genotoxicity and DNA damage. Studies have reported that lactobacilli have the ability to generate compounds with antioxidant, antigenotoxic and antimutagenic activity, which is why the present work aims to evaluate the effect of Lactobacillus strains and their intra and extracellular extracts against genotoxicity and oxidative stress as caused by acrylamide. Methods: a strain of Lactobacillus casei Shirota and a strain of Lactobacillus reuteri NRRL B-14171 were used, both were cultured in MRS broth and subjected to mechanical and enzymatic treatments to obtain extra and intracellular extracts. Lymphocytes were cultured in RPMI medium. Lipid peroxidation was evaluated by TBARS and the antioxidant capacity was measured in the extra and intracellular extracts with the ABTS technique, also using a strain of Saccharomyces cerevisiae RC 212 as a model. The reduction of lipid peroxidation in lymphocytes was measured by TBARS and the reduction of genotoxicity by reducing the formation of micronuclei in lymphocytes. Results: both strains evaluated, as well as their intra and extracellular extracts, showed the ability to counteract oxidative stress and genotoxicity caused by acrylamide. Conclusion: the results found suggest that the use of intra and extracellular extracts of both strains could be an alternative to reduce the effects of genotoxicity and oxidative stress caused by acrylamide without the need for a viable structure.

Investigation of cyto-genotoxic effects of a food sweetener Acesulfame potassium

Acesulfame potassium (ACE-K) is an artificial sweetener widely used in many foods. This investigation assessed the cytotoxic effect of ACE-K using MTT assay in human hepatocellular carcinoma (HepG2) cell line and the genotoxic effect using chromosomal aberrations (CAs), micronucleus (MN), and comet assays in human lymphocytes. 7.5-240 μg/mL concentrations of ACE-K were applied to cells. ACE-K notably decreased the cell viability on HepG2 cells, especially at 120 and 240 μg/mL at 24 and 48 h. It also significantly reduced the mitotic index (MI) at 60, 120, and 240 μg/mL at both treatments (24 and 48 h) in human lymphocytes. The frequency of the CAs significantly increased at 60, 120, and 240 μg/mL for 48 h treatment compared to control. However, no difference was observed in the frequency of MN and nuclear division index (NDI) at all the treatments. ACE-K also induced comet tail length, tail intensity, and moment at 15 μg/mL in isolated human lymphocytes. Therefore, ACE-K showed a cytotoxic effect in HepG2 cells as well as human lymphocytes at higher concentrations. It also exhibits a mild genotoxic effect by increasing the frequency of CAs at long-term treatment and DNA damaging effect only at 15 μg/mL.

Lack of genotoxicity of rhubarb (rhizome) in the Ames and micronucleus in vitro tests.

Hydroxyanthracene derivatives are widely distributed in the plant kingdom, mainly in botanicals such as the Hypericum, Rheum, Rhamnus and Aloe genera. For centuries, plants containing hydroxyanthracene derivatives have been used as herbal remedies, mainly as laxatives. The root and underground stem (rhizome) are used to make medicine, primarily for digestive complaints including constipation, diarrhoea, heartburn, stomach pain, gastrointestinal bleeding, and preparation for certain gastrointestinal diagnostic procedures. The use of hydroxyanthracene-containing botanicals has raised the attention of European Food Safety Authority (EFSA) for the potential genotoxicity activity, that in 2018 concluded "[.] and that there is a safety concern for extracts containing hydroxyanthracene derivatives although uncertainty persists". No genotoxic activity has been reported with other constituents such as rhein, physcion and chrysophanol. In the present study, Rhubarb ethanolic extract of ground rhubarb rhizome (hydroxyanthracene total content 1.39 %) was tested in the Ames Assay in Salmonella typhimurium and Escherichia coli, up to 5000µg/plate and up to 5000µg/mL in human lymphocytes Micronucleus Test (OECD 471 and 487 respectively) in vitro mutagenic and genotoxic effects. Under the experimental conditions used, the rhubarb rhizome extract showed no genotoxic activity.

Genotoxicity biomarkers in car repair workers from Barranquilla, a Colombian Caribbean City

ABSTRACT Exposure to chemicals and particles generated in automotive repair shops is a common and underestimated problem. The objective of this study was to assess the genotoxic status of auto repair workers with (1) a questionnaire to gather sociodemographic information and self-reported exposure to hazardous chemicals and (2) measurement of various biochemical parameters. Blood and oral mucosa samples were collected from 174 male volunteers from Barranquilla, Colombia, aged 18–55 years: 87 were active car repairmen and 87 were individuals with no known exposure to hazardous chemicals. Peripheral blood lymphocytes were collected for the comet and cytokinesis-blocking micronucleus (CBMN) assays, while oral mucosal epithelium extracted to quantify micronucleated cells (MNC). DNA was extracted to assess polymorphisms in the DNA repair (XRCC1) and metabolism-related genes (GSTT1 and GSTM1) using PCR-RFLP. DNA damage and frequency of micronuclei (MN) in lymphocytes and oral mucosa were significantly higher in exposed compared to control group. In both groups genotypes and allelic variants for XRCC1 and GSTT1 met the Hardy-Weinberg equilibrium (HWE). In contrast, GSTM1 deviated from HWE. In the exposed group genotypic variants were not correlated with DNA damage or MN presence in cells. DNA damage and occurrence of MN in mucosa and lymphocytes correlated with age and time of service (occupational exposure ≥ 3 years). In summary, workers in car repair shops exhibited genotoxic effects depending upon exposure duration in the workplace which occurred independent of DNA repair XRCC1 gene and metabolism genes GSTT1 and GSTM1. Date demonstrate that health authorities improve air quality in auto repair facilities to avoid occupational DNA damage.

Comparative analysis of physical doses and biomarker changes in subjects underwent Computed Tomography, Positron Emission Tomography-Computed Tomography, and interventional procedures

Even though the medical uses of ionizing radiation are well-acknowledged globally as vital tools for the improvement of human health, they also symbolize the major man-made sources of radiation exposure to the population. Estimation of absorbed dose and biological changes after radiation-based imaging might help to better understand the effects of low dose radiation. Because of this, we measured the Entrance Surface Dose (ESD) at different anatomical locations using Lithium tetraborate doped with manganese (Li2B4O7: Mn), recorded Dose Length Product (DLP) and Dose Area Product (DAP), analyzed Chromosomal Aberration (CA), Micronucleus (MN), gamma-H2AX (γ-H2AX), and p53ser15 proteins in the blood lymphocytes of patients (n = 267) underwent Computed Tomography (CT), Positron Emission Tomography-CT (PET/CT), and interventional procedures and healthy volunteers (n = 19). The DLP and effective doses obtained from PET/CT procedures were significantly higher (p < 0.05) when compared to CT. Fluoroscopic time and DAP were significantly higher (p < 0.05) in therapeutic compared to diagnostic interventional procedures. All the anatomical locations registered a significant amount of ESD, the ESD obtained from CT and interventional procedures were significantly (p < 0.05) higher when compared to PET/CT. Fluoroscopic time did not correlate with the ESD (eye, head, thyroid, and shoulder; R2 = 0.03). CA frequency after PET/CT was significantly higher (p < 0.001) when compared to CT and interventional procedures. MN frequency was significantly higher in 24-hs (p < 0.001) post-interventional procedure compared to 2-hs. The mean ± SD of mean fluorescence intensity of γ-H2AX and p53ser15 obtained from all subjects underwent PET/CT and interventional procedures did not show a significant difference (p > 0.05) between pre- and post-procedure. However, the relative fluorescence intensity of γ-H2AX and p53ser15 was >1 in 58.5 % and 65.8 % of subjects respectively. Large inter-individual variation and lack of correlation between physical dose and biomarkers suggest the need for robust dosimetry with a large sample size to understand the health effects of low dose radiation.

CytoRADx: A High-Throughput, Standardized Biodosimetry Diagnostic System Based on the Cytokinesis-Block Micronucleus Assay.

In a large-scale catastrophe, such as a nuclear detonation in a major city, it will be crucial to accurately diagnose large numbers of people to direct scarce medical resources to those in greatest need. Currently no FDA-cleared tests are available to diagnose radiation exposures, which can lead to complex, life-threatening injuries. To address this gap, we have achieved substantial advancements in radiation biodosimetry through refinement and adaptation of the cytokinesis-block micronucleus (CBMN) assay as a high throughput, quantitative diagnostic test. The classical CBMN approach, which quantifies micronuclei (MN) resulting from DNA damage, suffers from considerable time and expert labor requirements, in addition to a lack of universal methodology across laboratories. We have developed the CytoRADx™ System to address these drawbacks by implementing a standardized reagent kit, optimized assay protocol, fully automated microscopy and image analysis, and integrated dose prediction. These enhancements allow the CytoRADx System to obtain high-throughput, standardized results without specialized labor or laboratory-specific calibration curves. The CytoRADx System has been optimized for use with both humans and non-human primates (NHP) to quantify radiation dose-dependent formation of micronuclei in lymphocytes, observed using whole blood samples. Cell nuclei and resulting MN are fluorescently stained and preserved on durable microscope slides using materials provided in the kit. Up to 1,000 slides per day are subsequently scanned using the commercially based RADxScan™ Imager with customized software, which automatically quantifies the cellular features and calculates the radiation dose. Using less than 1 mL of blood, irradiated ex vivo, our system has demonstrated accurate and precise measurement of exposures from 0 to 8 Gy (90% of results within 1 Gy of delivered dose). These results were obtained from 636 human samples (24 distinct donors) and 445 NHP samples (30 distinct subjects). The system demonstrated comparable results during in vivo studies, including an investigation of 43 NHPs receiving single-dose total-body irradiation. System performance is repeatable across laboratories, operators, and instruments. Results are also statistically similar across diverse populations, considering various demographics, common medications, medical conditions, and acute injuries associated with radiological disasters. Dose calculations are stable over time as well, providing reproducible results for at least 28 days postirradiation, and for blood specimens collected and stored at room temperature for at least 72 h. The CytoRADx System provides significant advancements in the field of biodosimetry that will enable accurate diagnoses across diverse populations in large-scale emergency scenarios. In addition, our technological enhancements to the well-established CBMN assay provide a pathway for future diagnostic applications, such as toxicology and oncology.