The effect of granulocyte colony stimulating factor on genotoxicity in allogeneic peripheral blood stem cell transplantation donors: a prospective case-control study.

BACKGROUND: Every year, thousands of donors are exposed to granulocyte-colony stimulating factor (G-CSF) for stem cell mobilization in hematopoietic stem cell transplantations (HSCT). Previous studies about the genotoxicity of G-CSF were inconclusive. In this study, the genotoxic effects of G-CSF in peripheral blood stem cell (PBSC) donors were evaluated prospectively by using three different validated and reliable methods for the first time in the literature to the best of our knowledge. METHODS: Donors of PBSC transplantation (n=36), who received G-CSF were evaluated for genotoxicity by micronucleus test (MNT), nuclear division index (NDI), and comet assay (CA). Genotoxic effects are expected to cause an increase in MNT and CA values and decrease in NDI. Blood samples were collected at three timepoints (TP): before starting G-CSF (TP1), after G-CSF for five days (TP2), and one month after the last dose (TP3). Sixteen controls were included for baseline comparison of genotoxicity tests. CD34 cell counts and hemograms were also analyzed. RESULTS: MNT and CA parameters; comet and tail length, tail DNA%, and tail moment, showed no change in time whereas another CA parameter, Olive`s tail moment (OTM) was increased significantly at TP3 compared to both baseline and TP2 (p=0.002 and p=0.017, respectively). Nuclear division index decreased significantly at TP2 (p < 0.001), then increased above baseline at TP3 (p=0.004). Baseline comparison with controls showed higher MN frequency in donors without statistical significance (p=0.059). Whereas, CA results were significantly higher in controls. CD34 cell count showed moderate positive correlation with white blood cell count at TP2 (Pearson R=0.495, p=0.004). CONCLUSIONS: Our results showed the genotoxic effect of G-CSF in healthy donors, in two of the three tests performed, short-term effect in NDI, and long-lasting effect in OTM. So, this study provides novel information for the debate about the genotoxicity of G-CSF and supports the need for further studies with a larger sample size and longer follow-up.

Comprehensive stability study of benzimidazole drug residues in standard solution, muscle and milk.

The performance criteria of analytical methods and the necessity for stability analysis to provide the accuracy of the results of the analyzed samples are explained in European Commission Decision 2021/808/EC and the guidance document SANTE/2021/11312. Detection of time-dependent changes in drug concentrations during storage or transport and re-analysis of samples are crucial to obtain high-quality results and reliable data. In this way, it allows toxicologists to interpret the analytical results accurately in drug analyses. The aim of this study was comprehensively to investigate the stability of benzimidazoles (levamisole hydrochloride, albendazole, albendazole-sulfone, albendazole-2-amino sulfone, albendazole sulfoxide, oxfendazole, 5-hydroxythiabendazole, triclabendazole, ketotriclabendazole, thiabendazole, flubendazole, fenbendazole sulfone) in working solutions, muscle and milk samples. For this purpose, long-term stability was evaluated over 6 months and under four different storage conditions (4 °C, -20 °C, 20 °C light and 20 °C dark) in the matrix. The influences of three freeze-thaw cycles, autosampler stability, and 60 min storage at 40 °C were investigated for short-term stability. Simultaneously, the stability of the working solutions were established over 6 months and under five different conditions (4 °C, -20 °C, -80 °C, 20 °C light, and 20 °C dark). It was found that working solutions can be stored at -80 °C or -20 °C, and it is appropriate to prepare the standard working solution freshly once a month. Storage of milk at 4 °C is suitable for some analytes (ABZ-SO, FBZ-SO2, FLUBZ, ABZ, ABZ-NH2-SO2) whereas for the muscle almost all substances were stable only at -20 °C. Some freeze-thaw and short-term stability changes were detected.

The association of oxidative stress and DNA damage with XRCC1 and XRCC3 polymorphisms in radiology technicians.

Ionizing radiation has widespread use in medicine in the diagnosis and treatment of many medical conditions. Radiology technicians are one group that is occupationally exposed to low doses of radiation. There are questions regarding whether low dose exposure to radiation could have long-term health consequences. Assessing the effect of radiation on genetic material is essential for appraising long-term health results. Hereditary variations in DNA repair genes cause differentiation in individual responses to radiation related health effects. This study aimed to determine oxidative stress and DNA damage, and their relationship to XRCC1 (Arg399Gln) and XRCC3 (Thr241Met) polymorphisms in radiology technicians occupationally exposed to low dose radiation. Peripheral blood samples were collected from 45 radiology technicians and age-matched with 40 healthy control individuals working in office environments. Our results showed that radiology technicians had significantly greater oxidative stress and DNA damage than the control group, and women appeared more susceptible to occupational radiation exposure than men. Individuals with wild-type genotypes for XRCC1 (Arg/Arg) and XRCC3 (Thr/Thr) had less DNA damage. Lower DNA damage levels could be explained by the enhanced capacity to repair low dose radiation induced DNA damage. Further studies are needed to evaluate the role of DNA repair genes in individuals that are occupationally exposed to low dose radiation.

Association between delta-aminolevulinic acid dehydratase polymorphism and placental lead levels.

Lead inhibits the delta-aminolevulinic acid dehydratase (ALAD) activity and results in neurotoxic aminolevulinic acid accumulation in the blood. During pregnancy, lead in the maternal blood can easily cross the placenta. The aim of this study was to determine whether the maternal ALAD G177C polymorphism (rs1800435) was related to the placental lead levels. The study population comprised 97 blood samples taken from mothers to investigate ALAD G177C polymorphism and their placentas to measure lead levels. ALAD G177C polymorphism was detected by standard polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique and atomic absorption spectrometry (AAS) equipped with a graphite furnace and Zeeman background correction system was used for lead determination. The median placental lead levels for ALAD1-1, ALAD1-2 and ALAD2-2 genotypes were 7.54 µg/kg, 11.78 µg/kg and 18.53 µg/kg, respectively. Statistically significant association was found between the maternal ALAD G177C polymorphism and placental lead levels (p<0.05). This study suggested that maternal ALAD G177C polymorphism was associated with placental lead levels.

Does maternal VDR FokI single nucleotide polymorphism have an effect on lead levels of placenta, maternal and cord bloods?

INTRODUCTION: Individual susceptibility due to genetic variations appears to be an important factor in lead toxicity. As lead, ubiquitous atmospheric pollutant, behaves very similarly to calcium, gene polymorphisms in proteins involved in calcium homeostasis can affect lead toxicokinetics. Vitamin D receptor (VDR), a DNA-binding transcription factor, activates genes that encode proteins involved in calcium metabolism. Thus, the objective of this study was to determine the effect of maternal VDR FokI polymorphism on lead levels of maternal blood, placental tissue and cord blood. METHODS: The study population comprised 116 women and their respective placenta and umbilical cord. Venous blood samples were drawn from mothers to investigate both the lead levels and VDR FokI polymorphism. Cord blood samples and placentas were collected for lead levels. VDR FokI polymorphism was detected by standard polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method. Lead levels were analyzed by dual atomic absorption spectrometer system. RESULTS: Genotype frequencies of VDR FokI polymorphism were 49.2% FF, 44.8% Ff and 6.0% ff. The mean lead levels of maternal blood, placenta and cord blood were 36.76 ± 13.84 µg/L, 12.84 ± 14.47 µg/kg and 25.69 ± 11.12 µg/L, respectively. Maternal blood, placental and cord blood lead levels were found significantly to be higher in mothers with f allele for the VDR FokI polymorphism (p < 0.05). DISCUSSION: The present study indicated that this polymorphism had an effect on maternal and fetal lead levels and that mothers with F allele associated with lower lead concentration may protect their respective fetus against the toxic effects of lead exposure.

Maternal hemochromatosis gene H63D single-nucleotide polymorphism and lead levels of placental tissue, maternal and umbilical cord blood.

Human hemochromatosis protein (HFE), a major histocompatibility complex class I-like integral membrane protein, participates in the down regulation of intestinal iron absorption by binding to transferrin receptor (TR). HFE competes with transferrin-bound iron for the TR and thus reduces uptake of iron into cells. On the other hand, a lack of HFE increases the intestinal absorption of iron similarly to iron deficiency associated with increasing in absorption and deposition of lead. During pregnancy, placenta cannot prevent transfer lead to the fetus; even low-level lead poisoning causes neurodevelopmental toxicity in children. The aim of this study was to determine the association between the maternal HFE H63D single-nucleotide polymorphism and lead levels in placental tissue, maternal blood and umbilical cord bloods. The study population comprised 93 mother-placenta pairs. Venous blood from mother was collected to investigate lead levels and HFE polymorphism that was detected by standard PCR-RFLP technique. Cord bloods and placentas were collected for lead levels which were analyzed by dual atomic absorption spectrometer system. The HFE H63D genotype frequencies of mothers were found as 75.3% homozygote typical (HH), 23.6% heterozygote (HD) and 1.1% homozygote atypical (DD). Our study results showed that the placental tissue, umbilical cord and maternal blood lead levels of mothers with HD+DD genotypes were significantly higher than those with HH genotype (p<0.05). The present study indicated for the first time that mothers with H63D gene variants have higher lead levels of their newborn's placentas and umbilical cord bloods.

Evaluation of DNA damage using 3 comet assay parameters in workers occupationally exposed to lead.

The aim of this study was to investigate the association between DNA damage and blood lead levels in individuals occupationally exposed to lead. To evaluate this association, 61 workers exposed to lead were monitored in terms of DNA damage in blood lymphocytes. The levels of DNA damage were measured according to 3 comet assay parameters, including tail intensity (TI), tail moment (TM), and DNA tail (DNAt). A statistically significant positive correlation was found between the lead levels and TI, TM, and DNAt (p < .01). Smoking had independent effects on DNA damage. A statistically significant difference was observed between smokers and nonsmokers in regards to DNA damage parameters (p < .05). In addition, the lead and DNA damage levels in smokers were found to be significantly higher than the levels observed in nonsmoking workers (p < . 05). Our results show that exposure to lead induces genotoxic effects in peripheral lymphocytes, as measured by comet assays.

Lymphocyte DNA damage in Turkish asphalt workers detected by the comet assay.

Asphalt has a highly complex structure and it contains several organic compounds including polycyclic aromatic hydrocarbons and heterocyclic compounds. In this study, comet assay was used to detect the DNA damage in blood lymphocytes of 30 workers exposed to asphalt fumes and 30 nonexposed controls. This is the first report on Turkish asphalt workers' investigated DNA damage using the alkaline single cell gel electrophoresis (SCGE). The DNA damage was evaluated by the percentage of DNA in the comet tail (% tail DNA) for each cell. According to our results, workers exposed to asphalt fumes had higher DNA damage than the control group (p < 0.01). The present study showed that asphalt fumes caused a significant increase in DNA damage and the comet assay is a suitable method for determining DNA damage in asphalt workers.

An association between polymorphism of the NADH/NADPH oxidase p22phox (phagocyte oxidase) subunit and aging in Turkish population.

BACKGROUND AND AIMS: Aging is a complex and multifactorial process that is stimulated by a number of factors including genes and life-style. It is thought that the production of reactive oxygen species (ROS) in the face of antioxidant enzymes and molecules is related to aging and age-related diseases. NAD(P)H oxidase system is the predominant cellular source of ROS, and p22phox, the major component of that system, is essential for the activation of NAD(P)H oxidase. The aim of this study was to investigate the association between p22phox C242T single nucleotide polymorphism and aging in Turkish population. METHODS: Blood samples were collected from 332 volunteers between 18 and 95 years of age and were classified into three groups according to their ages as <65, 65-84 and ≥ 85. p22phox C242T polymorphism was genotyped by PCR-RFLP method. RESULTS: CC genotype frequency in the C242T polymorphism is higher in older group (≥ 85) than younger groups (<65 and 65-85), whereas CT + TT genotype frequency is lower in older group. When the p22phox C242T polymorphism was compared with the mean ages and age groups, statistically significant associations were found. CONCLUSIONS: We showed for the first time that human aging is significantly associated with p22phox C242T genotypes in Turkish population, being highest in CC, intermediate in CT, and lowest in TT homozygote. It is plausible to suggest that CC genotype might protect people from chronic inflammation, diseases as well as from oxidative stress and, thus, individuals with CC genotype might be more advantageous for aging as compared to those with CT + TT genotypes.