Micronuclei Induction in Amniotic Fluid Cells from Cyclophosphamide Treated Rats.

The aim of the study was to determine if amniotic fluid cells of rats can be used to provide evidence of genotoxicity. In order to do that micronuclei formation was induced in rats during pregnancy after treatment with cyclophosphamide (CP), at different CP doses. On gestational day 19, we collected the amniotic fluid and determined the frequency of micronucleated cells (MNCs) from the offspring. Samples were centrifuged and placed on clean slides. The smears were observed with an epifluorescence microscope. The number of MNCs in 2000 cells per pregnant rat was counted. The fetus weight and size were recorded and provided evidence of DNA damage caused by CP administration to their mothers. A significantly greater number of MNCs was observed only for the medium CP dose (P<0.01) and the high CP dose (P<0.02) groups versus the negative control group. Birth defects produced by the administration of the CP were evident in the CP-treated groups. This study showed an alternative method to determine if compounds administrated to pregnant rat cause damage to the genetic material of their offspring. Using micronuclei testing of amniotic fluid cells enables us to determine in one test the genotoxicity and the teratogenic potential of a compound.

Micronucleated Erythrocytes in Peripheral Blood from Neonate Rats Exposed by Breastfeeding to Cyclophosphamide, Colchicine, or Cytosine-Arabinoside.

Genotoxic exposure to chemical substances is common, and nursing mothers could transmit harmful substances or their metabolites to their offspring through breast milk. We explored the possibility of determining genotoxic effects in the erythrocytes of breastfeeding rat pups whose mothers received a genotoxic compound while nursing. Ten groups of female rats and five pups per dam were studied. The control group received sterile water, and the experimental groups received one of three different doses of cyclophosphamide, colchicine, or cytosine-arabinoside. Blood smears were prepared from samples taken from each dam and pup every 24 h for six days. There were increased numbers of micronucleated erythrocytes (MNEs) and micronucleated polychromatic erythrocytes (MNPCEs) in the samples from pups in the experimental groups (P < 0.02) and increased MNPCE frequencies in the samples from the dams (P < 0.05). These results demonstrate the vertical transmission of the genotoxic effect of the compounds tested. In conclusion, assessing MNEs in breastfeeding neonate rats to assess DNA damage may be a useful approach for identifying genotoxic compounds and/or cytotoxic effects. This strategy could help in screening for therapeutic approaches that are genotoxic during the lactation stage and these assessments might also be helpful for developing preventive strategies to counteract harmful effects.

Micronucleated erythrocytes in newborns rats exposed to three different types of ultraviolet-A (UVA) lamps from commonly uses devices.

Exposure to ultraviolet-A (UVA) light can accidentally cause adverse effects in the skin and eyes. UVA induces DNA damage directly by creating pyrimidine dimers or by the formation of reactive oxygen species that can indirectly affect DNA integrity. UVA radiation is emitted by lamps from everyday devices. In adult rats, micronucleated erythrocytes (MNE) are removed from the circulation by the spleen. However, in newborn rats, MNE have been observed in peripheral blood erythrocytes. The objective of this study was to use micronucleus tests to evaluate the DNA damage caused in newborn rats exposed to UVA light from three different types of UVA lamps obtained from commonly used devices: counterfeit detectors, insecticide devices, and equipment used to harden resins for artificial nails. Rat neonates were exposed to UVA lamps for 20min daily for 6days. The neonates were sampled every third day, and the numbers of MNE and micronucleated polychromatic erythrocytes (MNPCE) in the peripheral blood were determined. The rat neonates exposed to the three types of UVA lamps showed increased numbers of MNE and MNPCE from 48h to 144h (P<0.05 and P<0.001 respectively). However, no relationship was observed between the number of MNE and the wattage of the lamps. In conclusion, under these conditions, UVA light exposure induced an increase in MNE without causing any apparent damage to the skin.

A controlled clinical trial with pirfenidone in the treatment of pathological skin scarring caused by burns in pediatric patients.

BACKGROUND: Pathologic skin scarring reversion remains a big challenge for surgeons, as disfiguring scars have a dramatic influence on patient's quality of life. METHODS: A controlled clinical trial was conducted to evaluate 8% pirfenidone (PFD) gel administered topically 3 times a day during 6 months to 33 pediatric patients with hypertrophic scars caused by burns. A total of 30 patients with hypertrophic scars with identical Vancouver Scar Scale values were treated with pressure therapy and included as controls. Improvements were evaluated by Vancouver Scar Scale and a Visual Analog Scale. Safety parameters were determined by the presence of adverse events and monitoring laboratory and hematology parameters. RESULTS: Patients treated with PFD during 6 months presented a continuous monthly statistically significant scar regression in comparison with the initial Vancouver measurement (P = <0.001). PFD group showed a higher improvement of all scar features as compared with control group treated with pressure therapy (P = <0.001). In the PFD group, 9 of 33 patients (27%) had their scores decreased in Vancouver classification by more than 55%, 22 patients (67%) had a 30% to 45% decrease, whereas 2 patients (6%) had a 30% decrease or less. Control group treated with pressure therapy showed a slight improvement in 16% of cases on an average. Patients did not show serious adverse effects or laboratory alterations throughout the study. CONCLUSIONS: Topical administration of 8% PFD gel 3 times a day is more effective and safe in the treatment of hypertrophic scars caused by burns in children, as compared with standard pressure therapy.