Frequency Of Micronuclei Research Articles

Erythrocyte Recovery in Oreochromis niloticus Fish Exposed to Urban Effluents.

Urban activities pollute aquatic ecosystems, and the integrity of organisms such as fish. The use of cytological techniques, such as the analysis of blood cellular integrity using the Micronucleus test, can help detect mutagenic damage as a result to urban effluents exposure. In this context, this study aimed to evaluate the frequency of micronucleus and other nuclear abnormalities in Oreochromis niloticus fish environmentally exposed to urban effluents in relation to their erythrocyte recovery capacity when exposed to clean water (30 and 45days). The results indicated high copper, dissolved iron, nickel, and thermotolerant coliform levels in the urban stream. There was no difference in the frequency of micronuclei. In contrast, cells with nuclear nuclei, binucleates, kidney-shaped nuclei, notched nuclei, lobed nuclei, and segmented nuclei decreased according to the time the fish were exposed to clean water. When exposed to clean water, we conclude that urban fish recover from genotoxic and cytotoxic damage.

Indirect effects of interference of two emerging environmental contaminants on cell health: Radiofrequency radiation and gold nanoparticles

BackgroundThe global need for wireless technologies is growing rapidly. So, we have been exposed to a new type of environmental pollution: radiofrequency radiation (RFR). Recent studies have shown that RFR can cause not only direct effects but also indirect or non-targeted effects such as the bystander effect (BE). In this study, we investigated the BE induced by RFR in the present of gold nanoparticles (GNP). Moreover, we studied the expression of cyclooxygenase-2 (COX-2). MethodsNon-toxic dose of 15-nm GNP was used to treat the Chinese Hamster Ovary (CHO) cells. After 48 h of incubation, cells were exposed to 900 MHz GSM RFR for 24 h. Then we collected the cell culture medium of these cells (conditioned culture medium, CCM) and transferred it to new cells (bystander cells). Cell deaths, DNA breaks, oxidative stress and COX-2 expression were analyzed in all groups. ResultsThe results showed that RFR increased metabolic death in cells treated with GNP. Inversely, the colony formation ability was reduced in bystander cells and RFR exposed cells either in the presence or absence of GNP. Also, the level of reactive oxygen species (ROS) in GNP treated cells showed a significant reduction compared to those of untreated cells. However, RFR-induced DNA breaks and the frequencies of micronuclei (MN) were not significantly affected by GNP. The expression of COX-2 mRNA increased in RFR GNP treated cells, but the difference was not significant. ConclusionOur results for the first time indicated that RFR induce indirect effects in the presence of GNP. However, the molecular mediators of these effects differ from those in the absence of GNP. Also, to our knowledge, this is the first study to show that COX-2 is not involved in the bystander effect induced by 900 MHz RFR.

POST-SIEGE GENOTOXIC HAZARDS IN LAKE LANAO, PHILIPPINES BY MICRONUCLEUS ASSAY

Massive war pollutants brought by Marawi Siege in the Philippines have contaminated the city environs and the surrounding ancient Lake Lanao. Munition residues including heavy metals are reportedly genotoxic hence this study was conducted to determine the post-siege genotoxic hazards posed by the munition pollutants through micronucleus (MN) assay on the slow-moving edible gastropod snails Vivipara angularis Muller (locally known as “suso”) thriving in the lake. MN, a biomarker of genotoxicity was examined and counted in the hemocytes of exposed juvenile and adult snails. Results revealed that MN frequencies (no. of MN/1000 hemocytes) were significantly higher in snails sampled in Lake Lanao lakeshores than in the reference site Lake Dapao. Among adult samples, there was a decreasing trend of MN frequencies with increasing distance from lakeshore fronting warzone ‘ground zero’ where the battle was heaviest (site A) to sampling sites away from it: sites B, C, and D (Lake Dapao) which are 8.15 km, 24.41 km, and 34.45 km, respectively. Moreover, varied patterns of micronucleation were observed between age groups and sites, i.e., in all sites except C, adults had greater MN counts than juveniles which were significant in site A only. Unexpectedly juveniles displayed significantly high MN counts than adults in site C. The elevated MN frequencies in the snail hemocytes exposed to war pollution could be attributed to genotoxic munition residues eroded and washed into the lake water. Moreover, heavy metals which are common components of weaponries were also detected in the snail muscles, although at concentrations within safe levels but continued consumption may be cautioned to avoid biomagnification. Other genotoxins must be present in site C other than munition residues predisposing the juvenile snails. The results are baseline data on the MN frequencies in V. angularis exposed to war pollutants in Lake Lanao which need further investigation. Post-siege genotoxic hazards in the lake by MN assay cannot be ignored, thus local leaders must be informed of the results for possible intervention to protect the health and well-being of the community. 
 

Genotoxic and Mutagenic Assessment of PT-31, a Molecule with Antipsychotic Potential

Abstract: The PT-31 molecule, a potential antipsychotic, has demonstrated promising results when orally administrated to in vivo models. A recent study suggested the genotoxic and mutagenic po-tential of PT-31 after acute treatment by intraperitoneal route. This study aimed to evaluate PT-31 potential of inducing genotoxic or mutagenic damage after acute oral administration. For that, adult males and females Balb/C mice were treated acutely by oral administration with vehicle or PT-31 in three different doses (10, 20, and 40 mg kg-1). After 24 hours from PT-31 administration, animals were euthanized for performing the comet and micronucleus assays. None of the tested groups of PT-31 presented a significant increase in damage index and MN frequency. However, they presen-ted the following tendency on damage index: females presented a tendency at 40 mg kg-1 and males at 20 mg kg-1. Regarding the MN assay, male mice at the highest dose of 40 mg kg-1 presented a tendency of increased MN frequency. Also, there was a significant increase in PCE/NCE ratio in male mice. Results suggest that the male mice group presented higher susceptibility to damage. The tendency of increased damage to DNA and MN frequency suggests that the molecule PT-31 may induce reparable damage to DNA, and these DNA strand repairs may have originated from the MN. However, significant genotoxic and mutagenic effects were not observed. This study reinforces the atypical profile of the molecule as much as its safety by oral route administration.

Low-Frequency Pulsed Magnetic Field Enhances the Genotoxicity of Chromium(VI) Ions in Amphibians

This article reports the results of a study of Cr(VI) ions mutagenicity in the erythrocytes of Bufo viridis tadpoles under the influence of a low-frequency pulsed magnetic field (LF PMF). The tadpoles were randomly divided into 14 groups (n = 7). One group of intact tadpoles served as control. Other groups were experimental. The first six groups were placed for 24 h in water containing Cr(VI) at different concentrations (0.025, 0.05, 0.125, 0.25, 0.375, and 0.50 mg/L). The eighth group was subjected to an 8-h exposure to LF PMF (41 mT, 16 Hz). The remaining six groups of tadpoles were kept for 24 h in water with Cr(VI) ions at the specified concentrations and were also irradiated with LF PMF (41 mT, 16 Hz) during the first 8 h of this period. A day after the exposure, blood smears were taken, and the frequencies of micronuclei and nuclear anomalies in erythrocytes were analyzed. The results reveal that low concentrations of Cr(VI) (0.025 and 0.05 mg/L), unlike the higher ones (0.125 mg/L and above), did not significantly affect the frequencies of the analyzed anomalies. The combined action of Cr(VI) and LF PMF significantly increased the frequencies of the recorded anomalies in all the six variants of the experiment. The synergistic effect of Cr(VI) and LF PTF was shown.

Evaluation of the Genotoxic and Histological Effects in Neotropical Fish Prochilodus Lacustris (Pisces, Prochilodontidae) in Conservation Area of the Brazilian Northeast.

Human activities significantly impact the aquatic biota in lacustrine environments, leading to negative environmental consequences. Due to this, this study was carried out to evaluate the genotoxic and histological biomarkers in the gills and kidneys of Prochilodus lacustris. The collection of fish and water was conducted in three distinct stations (S1, S2, S3) in an international protected area in northeast Brazil. The histological alterations index was used to assess changes in the gills and kidneys at a histological level. In addition, micronucleus and nuclear abnormalities tests were employed to examine damage to the genetic material. According to the frequency of Micronucleus, nuclear injuries, and the histopathology of gills and kidneys, it can be inferred that station S1 had the highest impact on the fish, causing significant harm. Based on our findings, the organisms residing in Lake Açu are adversely affected by the poor environmental conditions. This raises doubts about the effectiveness of the Protection Area by Humid Zone of International Interest in Northeast Brazil.

DNA damage in workers exposed to pigment grade titanium dioxide (TiO2) and association with biomarkers of oxidative stress and inflammation

The present study was aimed at investigating DNA damage, micronuclei frequency and meta-nuclear alterations in buccal cells of workers involved in pigment-grade TiO2 production (15 exposed and 20 not-exposed). We also assessed associations of genotoxicity biomarkers with oxidative stress/inflammatory biomarkers in urine and exhaled breath condensate (EBC), as well as possible associations between biomarkers and reported respiratory symptoms. In spite of compliance with TiO2 Occupational Exposure Limits, results showed increased direct/oxidative DNA damage and micronuclei frequency in exposed workers. Genotoxicity parameters were associated with oxidative stress/inflammation biomarkers in urine and EBC, thus confirming that TiO2 exposure can affect the oxidative balance. Workers with higher genotoxic/oxidative stress biomarkers levels reported early respiratory symptoms suggesting that molecular alterations can be predictive of early health dysfunctions. These findings suggest the need to assess early health impairment in health surveillance programs and to address properly safety issues in workplaces where TiO2 is handled.

Toxic, genotoxic, mutagenic, and bioaccumulative effects of metal mixture from settleable particulate matter on American bullfrog tadpoles (Lithobates catesbeianus)

Amphibians are more susceptible to environmental stressors than other vertebrates due to their semipermeable skin and physiological adaptations to living in very specific microhabitats. Therefore, the aim of the present study was to investigate the effects of a metal mixture from settleable particulate matter (SePM) released from metallurgical industries on Lithobates catesbeianus tadpoles. Endpoints analyzed included metal bioconcentration, morphological (biometrical indices), hematological parameters (hemoglobin and blood cell count), and erythrocyte DNA damage (genotoxicity and mutagenicity). American bullfrog tadpoles (Gosner's stage 25) were kept under control condition (no contaminant addition) or exposed to a sub-lethal and environmentally relevant concentration (1 g.L−1) of SePM for 96 h. Tadpoles exposed to SePM exhibited elevated whole blood levels of Fe56, AL, Sn, Pb, Zn, Cr, Cu, Ti, Rb, V, Ce, La, Ag, As. SePM-exposed tadpoles showed a significant decrease in condition factor (12%) and increases in hepatosomatic index (25%), hemoglobin concentration (17%), and total leukocytes (82%), thrombocytes (90%), and monocytes (78%) abundance. In addition, exposed tadpoles showed higher MN and ENAs (340 and 140%, respectively) frequencies, and erythrocyte DNA damage with approximately 1.2- to 1.8-fold increases in comet parameters. Taken together, these results suggest that the multimetal mixture found in SePM is potentially genotoxic and mutagenic to L. catesbeianus tadpoles, induces stress associated with hematological changes, and negatively affects growth. Although such contamination occurs at sublethal levels, regulatory standards are needed to control the emission of SePM and protect amphibian populations.

An exploration of biomarkers for noise exposure: mitochondrial DNA copy number and micronucleus frequencies in Chinese workers

ABSTRACT Few studies have been conducted that use biomarkers as early warning signals for noise-associated health hazards. To explore potentially effective biomarkers for noise-exposed populations, we recruited 218 noise-exposed male workers in China. We calculated cumulative noise exposure (CNE) through noise intensity and noise-exposed duration. When the model was fully adjusted, ln-transformed relative mitochondrial DNA copy number (mtDNAcn) decreased by 0.014 (95% confidence interval (CI): −0.026, −0.003) units with each 1 dB(A)∙year increase in CNE levels. CNE was further included in the model as a grouping variable, and the results showed a negative dose-effect relationship between relative mtDNAcn and CNE (P-trend = 0.045). However, we did not find a correlation between CNE and micronucleus (MN) frequencies. Our findings suggest that CNE in workers was associated with a decrease in relative mtDNAcn which may provide a potential biomarker for noise and for certain health risk but not with MN frequencies.

Genotoxic and Cytotoxic Effects of Cone Beam Computed Tomography and Multidetector Computed Tomography on Exfoliated Buccal Epithelial Cells.

Cone beam computed tomography (CBCT) and multidetector computed tomography (MDCT) are frequently used in dental and maxillofacial problems. This study aimed to assess the genotoxicity and cytotoxicity effects of CBCT and MDCT radiographies on exfoliated buccal epithelial cells during dental examinations. This prospective experimental study was conducted at Babol University of Medical Sciences (Babol, Iran) from March 2021 to April 2021. Buccal mucosa smears were collected bilaterally pre-exposure and 12 days after CBCT or MDCT examinations. To compare the frequency of micronuclei and other cytotoxic cellular changes such as pyknosis, karyolysis, and karyorrhexis, the paired sample t test and Wilcoxon test were used. In addition, independent sample t test, Mann-Whitney, and Chi square tests were used to investigate the differences between the imaging methods and between men and women. All statistical analyses were performed using the SPSS software, and P≤0.05 was considered statistically significant. The current study included 60 adult patients (30 patients in each group), ranging in age from 21 to 50 years. The micronuclei and the other cytotoxic cellular changes increased significantly after CBCT and MDCT radiographic examinations on the 12th day compared to the pre-exposure results (P<0.001). MDCT had statistically higher cytotoxic and genotoxic effects than CBCT (9.4%, 23.1%, and 40% higher values in micronucleus frequency, the mean frequency of micronuclei, and other cytotoxic changes, respectively). There were no significant differences between men and women in the two examination methods (P=0.46 and P=0.49, respectively). Dental examinations with CBCT and MDCT can increase cytotoxicity and chromosomal damage in both men and women. Due to its lower radiation toxicities, CBCT can be recommended as an alternative to MDCT for dental examinations.

A comparative study on chromium-induced micronuclei assessment in the peripheral blood of Hsd:ICR mice.

This study investigated the genotoxic effects of chromium (Cr) in Hsd:ICR mice, considering factors such as oxidative state, apoptosis, exposure pathway, duration, pregnancy, and transplacental exposure. Genotoxicity was assessed using the erythrocytes' micronucleus (MN) assay, while apoptosis was evaluated in nucleated blood cells. The results showed that Cr(III) (CrK(SO4 )2 and CrCl3 ) did not induce any marked genotoxic damage. However, Cr(VI) (CrO3 , K2 Cr2 O7 , Na2 Cr2 O7 , and K2 CrO4 ) produced varying degrees of genotoxicity, with CrO3 being the most potent. MN frequencies increased following 24-h exposure, with a greater effect in male mice. Administering 20 mg/kg of CrO3 via gavage did not lead to significant effects compared to intraperitoneal administration. Short-term oral treatment with a daily dose of 8.5mg/kg for 49 days elevated MN levels only on day 14 after treatment. Pregnant female mice exposed to CrO3 on day 15 of pregnancy exhibited reduced genotoxic effects compared to nonpregnant animals. However, significant increases in MN levels were found in their fetuses starting 48 h after exposure. In summary, data indicate the potential genotoxic effects of Cr, with Cr(VI) forms inducing higher genotoxicity than Cr(III). These findings indicate that gender, exposure route, and pregnancy status might influence genotoxic responses to Cr.

Purebred dogs show higher levels of genomic damage compared to mixed breed dogs

Inbreeding is a common phenomenon in small, fragmented or isolated populations, typical conditions of many threatened species. In the present paper, we used a new non-invasive approach based on the buccal micronucleus assay to evaluate the possible relationships between inbreeding and genomic damage using the dog as model species. In particular, we assessed the frequencies of micronuclei and other nuclear aberrations in a group of purebred dogs (n = 77), comparing the obtained data with those from a control group represented by mixed breed dogs (n = 75). We found a significant increase of micronuclei, nuclear buds and total nuclear aberrations frequencies in purebred dogs compared to mixed-bred dogs. The absence of significant differences in the frequency of micronuclei and other nuclear aberrations amongst different breeds reinforces the hypothesis that the observed increased genomic damage amongst purebred dogs may not be due to a different genomic instability typical of a particular breed, but to inbreeding itself. This hypothesis is further confirmed by the fact that other endogen confounding factors, such as sex, age and weight, do not contribute significantly to the increase of genomic damage observed amongst purebred dogs. In conclusion, results presented in this study showed that, in purebred dogs, inbreeding may increase the levels of genomic damage. Considering that genomic damage is associated with increased physiological problems affecting animal health, the results we obtained may represent a stimulus to discourage the use of intensive inbreeding practices in captive populations and to reduce the fragmentation of wild populations.

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.

Investigation of the Genotoxic Effects of the Analgesic Drugs Piroxicam and Tenoxicam in Human Lymphocytes

Analgesics are one of the most widely used drug groups in the world. Since the genotoxic and carcinogenic effects of some analgesic drugs have been detected, studies investigating these effects have increased. In this study, the genotoxic effects of the analgesic drugs Tenoxicam and Piroxicam were investigated in vitro in human peripheral lymphocytes by chromosomal aberrations (CAs) and micronucleus (MN) assays. In addition, mitotic index (MI) and nuclear division index (NDI) values were also determined. As a result, no difference in chromosomal abnormalities was observed in both 24 and 48 hours of Piroxicam treatment. Micronucleus frequency was increased at the three highest concentrations (0.94, 1.88 and 3.75 µg/mL) compared to the control. Piroxicam significantly decreased MI compared to both control and solvent control at concentrations of 1.88 and 3.75 µg/mL at all exposure times. Tenoxicam showed a statistically significant increase at the highest concentration (10 μg/mL) compared to the control in the 24 h CA treatment. On the other hand, no effect was observed in 48-hour CA treatment. It was concluded that tenoxicam did not cause a toxic effect at any concentration except the highest concentration (10 μg/mL) in the MN assay results. Mitotic index (MI) significantly decreased at concentrations of 1.25, 2.5, 5 and 10 μg/mL. Nuclear division index (NDI) results did not change for both agents. In conclusion, both agents were found to be genotoxic only at high concentrations and the effect was weak. This study is pioneering as there have been no previous in vitro studies in human peripheral lymphocytes for both Piroxicam and Tenoxicam. These results need to be supported by different cell groups and in vivo assays.

RED RICE BRAN EXTRACT SUPPRESSES COLON CANCER CELLS VIA APOPTOSIS INDUCTION/CELL CYCLE ARREST AND EXERTS ANTIMUTAGENIC ACTIVITY.

Red rice bran extract (RRBE) contains many biologically active substances exerting antioxidant and anti-inflammatory effects. To evaluate the anticancer potential of RRBE in human colon cancer cells and its mutagenic/antimutagenic effects on nonmalignant cells. The cytotoxic effect of RRBE was determined by trypan blue exclusion in HCT116, HT29 cell lines and a non-cancerous HEK293 cell line, and its antiproliferative effect using MTS and colony formation assay. The apoptosis induction was evaluated using ELISA, and the apoptotic rate and cell cycle progression were assessed by flow cytometry. The mutagenic/ antimutagenic potential of RRBE was analyzed by micronucleus assay in the V79 cell line. RRBE caused a dose-dependent reduction of cell viability in colon cancer cells and showed a limited cytotoxicity against HEK293 cells. The treatment with RRBE suppressed proliferation of HCT116 and HT29 cells and induced apoptosis as evidenced by the increased DNA fragmentation and the apoptotic cell counts. Furthermore, RRBE treatment significantly increased the number of cells at the G2/M phase triggering the arrest of the cell cycle in colon cancer cells. Interestingly, RRBE did not increase the micronucleus frequency in V79 cells but reduced the micronucleus formation caused by mitomycin C. RRBE effectively suppressed proliferation, induced apoptosis, and caused a cell cycle arrest in human colon cancer cells while being non-mutagenic and exerting antimutagenic effects in vitro.

Baseline micronucleus frequencies and 60Co cytokinesis-block micronucleus assay dose-response curve for biodosimetry in Vietnam.

This study aims to establish baseline micronucleus (MN) frequencies from various populations of residents in Vietnam and develop a 60Co dose-response curve for the cytokinesis-block micronucleus (CBMN) assay. Blood samples were exposed in vitro to a 60Co source at a dose rate of 275mGy per min in a range of 0.1 to 4.0Gy. MN background frequencies were 4.5±3.2, 7.3±4.6, 7.0±3.8 and 13.1±6.7 in 1000 binucleated (BN) cells for 96 healthy donors, 22 male radiation workers and 12 breast cancer patients, respectively. Blood samples from three healthy donors were used to generate the MN dose-response curve: y=C + (0.0496±0.0069)D + (0.0143±0.0026)D2. This curve was verified through an inter-laboratory comparison (RENEB ILC 2021). Our findings highlight the significance of the CBMN assay as an additional essential tool for biodosimetry in Vietnam.

Assessment of Micronuclei Frequency in the Peripheral Blood of Adult and Pediatric Patients Receiving Fractionated Total Body Irradiation

The cytokinesis-block micronucleus (CBMN) assay is an established method for assessing chromosome damage in human peripheral blood lymphocytes resulting from exposure to genotoxic agents such as ionizing radiation. The objective of this study was to measure cytogenetic DNA damage and hematology parameters in vivo based on MN frequency in peripheral blood lymphocytes (PBLs) from adult and pediatric leukemia patients undergoing hematopoietic stem cell transplantation preceded by total body irradiation (TBI) as part of the conditioning regimen. CBMN assay cultures were prepared from fresh blood samples collected before and at 4 and 24 h after the start of TBI, corresponding to doses of 1.25 Gy and 3.75 Gy, respectively. For both age groups, there was a significant increase in MN yields with increasing dose (p < 0.05) and dose-dependent decrease in the nuclear division index (NDI; p < 0.0001). In the pre-radiotherapy samples, there was a significantly higher NDI measured in the pediatric cohort compared to the adult due to an increase in the percentage of tri- and quadri-nucleated cells scored. Complete blood counts with differential recorded before and after TBI at the 24-h time point showed a rapid increase in neutrophil (p = 0.0001) and decrease in lymphocyte (p = 0.0006) counts, resulting in a highly elevated neutrophil-to-lymphocyte ratio (NLR) of 14.45 ± 1.85 after 3.75 Gy TBI (pre-exposure = 4.62 ± 0.49), indicating a strong systemic inflammatory response. Correlation of the hematological cell subset counts with cytogenetic damage, indicated that only the lymphocyte subset survival fraction (after TBI compared with before TBI) showed a negative correlation with increasing MN frequency from 0 to 1.25 Gy (r = −0.931; p = 0.007). Further, the data presented here indicate that the combination of CBMN assay endpoints (MN frequency and NDI values) and hematology parameters could be used to assess cytogenetic damage and early hematopoietic injury in the peripheral blood of leukemia patients, 24 h after TBI exposure.

Determination of the genotoxic effects of sweeteners, mannitol and lactitol

The changes in dietary habit around the world have led to an increased use of additives in the food. The safety of food additives has been a main focus of research for many years due to the ongoing debate on their potential effects on health. In this study, the in vitro genotoxic effects of mannitol and lactitol, polyols used as sweetener food additives, were evaluated using chromosomal aberrations (CAs) and micronucleus (MN) assays in human peripheral lymphocytes. Additionally, the effects of these sweeteners on the mitotic index (MI) and nuclear division index (NDI) were investigated. Concentrations of 500, 1000, 2000, 4000, and 8000 μg/mL for mannitol and 250, 500, 1000, 2000, and 4000 μg/mL for lactitol were used. The results indicated that both polyols did not affect CA and MN frequency, and did not cause a significant change in NDI at all treatment concentratoins. However, mannitol (except at concentrations of 500 and 1000 μg/mL) and lactitol (except at 250 μg/mL) significantly decreased the MI compared to the control at almost all concentrations and treatment times. In conclusion, it was observed that mannitol and lactitol did not have a significant genotoxic effect at the concentrations used in human lymphocytes in vitro.

Formalin Induced Micronucleus Formation in the Buccal Mucosa of Pathology Laboratory Workers.

Formaldehyde is an irritating substance that is categorized as a definite carcinogen (Group A1), according to the International Agency for Research on Cancer (IARC). This study was conducted to determine the role of this substance in the frequency of micronuclei (MN) in the buccal mucosal cells due to long-term exposure of the pathology staff to formaldehyde. In this case-control study, 32 pathology laboratory staff members were assigned to the case group, and 32 staff members who were not exposed to formaldehyde were assigned to the control group. Buccal mucosa cells were collected with a wet spatula and stained with Papanicolaou stain. In each sample, 500 cells were counted; then, the frequency of MN and the average number of MN in the micronucleated cells were assessed and compared between the 2 groups using the independent t test. Furthermore, the relationship between gender and MN was evaluated using the independent t test. The relationship between years of exposure and time of exposure during the day (in hours) for the case group, as well as the relationship between age and frequency of MN was analyzed using the Pearson correlation coefficient. The mean frequency of MN in exfoliated buccal cells was 18.33±12.36 in the case group, which was significantly higher than the control group (10.55±6.22; P=0.003). The difference in the mean number of total MN in the micronucleated cells was not significant between the case and control groups (P=0.11). The relationship between sex, age, and years of exposure with the mean frequency of MN and the total number of MN in the micronucleated cells was not significant. The relationship between exposure time during the day and both the mean frequency of MN and the total number of MN in the micronucleated cells was significant (P=0.03). Formaldehyde exposure and extended time of exposure during the day can increase the frequency of MN, which can prognosticate the incidence of precancerous and cancerous lesions. Therefore, continuous exposure to formaldehyde can be considered an occupational health hazard, though further studies are needed to confirm this result.

Synthesis and Biological Toxicity Evaluation of Red Light-Emitting Carbon Quantum Dots

This study delineates the successful fabrication of red light-emitting carbon quantum dots (R-CQDs), approximately 3.5 nm in size, via hydrothermal methods. These carbon quantum dots (CQDs) display distinctive fluorescence properties, particularly a laser-dependency. The infrared and Raman spectra were subjected to a thorough investigation, revealing the presence of hydroxyl, amino, and carboxyl groups on the surface of the CQDs. Experimental findings indicate a significant correlation between the antibacterial effect of R-CQDs on E. coli and Yeast and their concentration. Subsequent research suggests that this antibacterial activity primarily stems from the CQDs’ disruption of cell membrane integrity, leading to the leakage of intracellular substances and consequently inhibiting the growth of these two microorganisms. The study also reveals that R-CQDs can trigger chromosomal aberrations in the root tip cells of broad beans and induce micronuclei formation. The frequency of micronuclei is directly proportional to the CQDs dosage, and an extended treatment duration results in an increased micronucleus rate. This suggests potential damage to the genetic material of broad beans by CQDs, which could adversely affect their growth and development. The study further identifies a significant impact of R-CQDs on the height of rice seedlings, causing a substantial reduction. Moreover, it was found that CQDs can infiltrate the rice body and instigate oxidative stress responses.