Ana L. Zamora-Perez

Spontaneous micronuclei in peripheral blood erythrocytes from 54 animal species (mammals, reptiles and birds): part two.

The normal numbers of micronucleated erythrocytes (MNE) observed in peripheral blood samples differ among species. This depends on the effectiveness of the spleen (or the rest of the reticuloendothelial system) to withdraw them from circulation. In our previous report, we assessed the number of MNE in the peripheral blood of 35 mammalian species. Here we show the results observed in 54 species including mammals, reptiles and birds. We obtained 212 peripheral blood samples from different species. In 14 species, only one individual was studied. Slides were stained with acridine orange. The total number of MNE (normo and polychromatic) in 10,000 erythrocytes per animal are shown. The species that display the higher MNE were: ocelote, lynx, owl, gray squirrel, hedgehog, lion, orange fronted parakeet and common barn owl. For this reason, these species could be tested as monitors for genotoxic events. Another interesting observation was that in the gray squirrel, we found the highest values of MNE in the smaller (younger) animals when compared with the larger (older) of the same species.

IL-12 and IL-18 levels in serum and gingival tissue in aggressive and chronic periodontitis.

OBJECTIVE The aim of this study was to compare the levels of interleukin-12 (IL-12) and IL-18 in gingival tissue and serum between patients with chronic (n = 18) or aggressive periodontitis (n = 12) and healthy subjects (HS) (n = 9). METHODS Gingival tissue biopsies and serum were obtained from all study subjects. The tissue was homogenized and cytokines IL-12 and IL-18 were quantified by enzyme-linked immunosorbent assay. RESULTS Interleukin-12 levels in gingival tissue were significantly higher in aggressive periodontitis patients than in HS; serum IL-12 was significantly elevated in aggressive periodontitis relative to both chronic periodontitis (CP) and HS. IL-18 levels in gingival tissue showed no significant differences between the groups. Patients with CP showed significantly elevated levels of serum IL-18 compared with HS; however, the aggressive periodontitis group showed no significant differences with either the CP group or the HS. CONCLUSIONS Our results showed higher levels of IL-12 in gingival tissue and serum of patients with aggressive periodontitis, and IL-18 was elevated in the serum of CP patients. The patterns of IL-12 and IL-18 are different in chronic and aggressive periodontitis; this finding suggests distinctive mechanisms of immunopathogenesis between these forms of periodontitis.

Increased number of micronuclei and nuclear anomalies in buccal mucosa cells from people exposed to alcohol-containing mouthwash

The aim of this study was to evaluate the effects of alcohol-containing mouthwash on the induction of micronuclei and nuclear anomalies in exfoliated buccal cells, including binucleated cells, cells with nuclear buds, and karyolitic, karyorrhectic, condensed chromatin, and pyknotic cells. Buccal mucosa cells were collected from 107 healthy participants who were divided into three groups: control subjects who did not use mouthwash (n = 33), subjects who were exposed for 30 days and two times rinsing with 30 seconds each time to alcohol-containing mouthwash (n = 38; 26% ethanol concentration); and subjects exposed to a non-alcohol-containing mouthwash (n = 36). A slide was used to collect cells from the oral mucosa from the inner lining of both cheeks. Samples were spread directly onto two separate, precleaned and precoded slides. Smears were air-dried, fixed, stained, and analyzed by microscopy for micronuclei and nuclear anomalies. Frequency of micronuclei, nuclear buds, and karyolitic, karyorrhectic, and condensed chromatin cells increased significantly (P < 0.05) in the alcohol-containing mouthwash group after mouthwash exposition, compared with both the control and the non-alcohol-containing mouthwash groups. Our results suggest that subjects exposed to alcohol-containing mouthwash exhibited an increase in frequency of micronuclei and nuclear anomalies in oral mucosal cells, which is directly related to DNA damage.

Micronucleated erythrocytes in preterm newborns exposed to phototherapy and/or oxygentherapy.

Preterm newborns (PNBs) have an immature antioxidant defense system, and this makes them more susceptible to oxidative stress generated by postnatal treatments. The objective was to determine whether micronucleated erythrocytes increase in PNB by postnatal treatments such as oxygentherapy and phototherapy. We counted micronucleated erythrocytes and micronucleated polychromatic erythrocytes as DNA damage in 72 blood samples of PNB at 26-36 weeks of gestation, taken between 1 and 84 h after birth. We assume that more time passed between sampling and birth would correspond to greater time of exposure to oxygen (37 cases) and phototherapy plus oxygen (35 cases). In the PNB only exposed to oxygen, the differences were not significant, while there was a significant increase in micronucleated polychromatic erythrocytes with increasing exposure time in those treated with phototherapy plus oxygen. In conclusion, our results suggest that the MN increase from phototherapy can be observed in peripheral blood erythrocytes of PNB.

Genotoxic evaluation of pirfenidone using erythrocyte rodent micronucleus assay.

Pirfenidone is a non-steroidal antifibrotic compound that has been proposed in clinical protocols and experimental studies as a pharmacological treatment for fibroproliferative diseases. The objective of this study was to determine the genotoxicity or cytotoxicity of three doses of pirfenidone using the micronuclei test in peripheral blood erythrocytes of rodent models. Pirfenidone was administered orally to Balb-C mice for 3 days, and also was administered topically to hairless Sprague Dawley rats during the final stage of gestation. Mice were sampled every 24 h over the course of 6 days; pregnant rats were sampled every 24 h during the last 6 days of gestation, and pups were sampled at birth. Blood smears were analyzed and the frequencies of micronucleated erythrocytes (MNEs), micronucleated polychromatic erythrocytes (MNPCEs), and the proportion of polychromatic erythrocytes (PCEs), were recorded in samples from mice, pregnant rats and rat neonates. Increases in MN frequencies (p<0.03) were noted only in the positive control groups. No genotoxic effects or decreased PCE values were observed neither in newborn rats transplacentally exposed to pirfenidone, or in two adult rodent models when pirfenidone was administered orally or topically.

Genetic profile of overweight and obese school-age children

Obesity is associated with overproduction of free radicals that promotes genotoxicity and could be measured as micronuclei (MN) and nuclear abnormalities (NA) in buccal mucosa cells. The frequency of MN and NA in buccal mucosa cells from overweight and obesity school-age children was determined. In a cross-sectional study, four anthropometric parameters were obtained from each child and one buccal mucosa sample was collected from each child. The slides were stained with orcein and fast green and microscopically analyzed for MN and NA. Twenty overweight and obesity school-age children (7–11 years old) from three schools located at the metropolitan area of Guadalajara were selected to form three groups with 20 children each, according to the weight features as follows: (1) normal weight; (2) overweight; and (3) obesity. No marked differences were found between groups for frequency of MN and NA. Genotoxicity, as indicated by increase in binucleated (BN) cells, was found in children within both overweight and obese groups exposed to passive tobacco smoke. There was no evidence of genetic instability in overweight and obese school-age children and no associations between body weight and genotoxicity markers found.

Nuclear abnormalities in buccal mucosa cells of patients with type I and II diabetes treated with folic acid.

Diabetes mellitus (DM) is characterized by high blood glucose. Excessive production of free radicals may cause oxidative damage to DNA and other molecules, leading to complications of the disease. It may be possible to delay or reduce such damage by administration of antioxidants such as folic acid (FA). The objective of this study was to determine the effect of FA on nuclear abnormalities (NAs) in the oral mucosa of patients with DM. NAs (micronucleated cells, binucleated cells, pyknotic nuclei, karyorrhexis, karyolysis, abnormally condensed chromatin, and nuclear buds) were analyzed in 2000 cells from 45 healthy individuals (control group) and 55 patients with controlled or uncontrolled type I or II DM; 35 patients in the latter group were treated with FA. Samples were taken from the FA group before and after treatment. An increased rate of NAs was found in patients with DM in comparison with that of the control group (P<0.001). FA supplementation in patients with DM reduced the frequency of NAs (20.4 ± 8.0 before treatment vs. 10.5 ± 5.2 after treatment; P<0.001). The type I and type II DM and controlled and uncontrolled DM subgroups were analyzed in terms of sex, age, and smoking habit. The significantly reduced frequencies of buccal mucosa cells with micronuclei, binucleation, pyknosis, karyorrhexis, karyorrhexis+abnormally condensed chromatin, karyolysis, and nuclear buds produced by FA supplementation in DM patients (P<0.02) are consistent with the idea that free radicals are responsible for the increased frequency of NAs in DM patients.

Micronucleated erythrocytes in newborns of rat dams exposed to ultraviolet-A light during pregnancy; protection by ascorbic acid supplementation

Pregnant hairless rat dams were exposed to ultraviolet-A light (UVA) to induce micronucleated erythrocytes (MNE) in their fetuses. The control group was exposed to conventional light; the experimental groups were exposed to UVA (365nm) during gestational days 16-21. In some cases, ascorbic acid (Asc) was administered in the drinking water from gestational day 15 until delivery. Dams were sampled at 48-h intervals during gestation, from day 16 until delivery. Blood was also obtained from neonates at birth; MNE, micronucleated polychromatic erythrocytes (MNPCE), and polychromatic erythrocytes (PCE) were scored. Increased MNE and MNPCE were observed in neonates born to mothers exposed to UVA for 40, 80 or 160min, compared to the control group. Asc treatment reduced MNE and MNPCE induction.

Effects of blue light phototherapy on DNA integrity in preterm newborns

In previous studies, exposure to phototherapy, but not oxygen therapy, resulted in damage to genetic material in newborns. The objective of this study was to determine whether micronucleated erythrocytes (MNE) increased in preterm newborns (PNBs) who were exposed to blue light phototherapy lamps. MNE of mature organisms are rapidly eliminated by the spleen, and the presence of MNE has been related to immaturity in some species. Furthermore, PNBs present spontaneous MNE. Blood samples were taken from 17 PNBs at birth to establish baseline frequencies (0 h). After beginning blue light phototherapy, blood samples were obtained from 11 of these PNBs at 24-h intervals for 96 h, after the baseline sample. MNE and micronucleated polychromatic erythrocytes (MNPCE) were counted. The basal values of MNE and MNPCE from 17 PNBs were 0.62 ± 0.48 and 1.52 ± 1.28 (‰), respectively, and no increase in MNE or MNPCE was observed in the serial samples of 11 PNBs exposed to blue light and oxygen therapies, though previous studies reported increases using other types of lamps. In conclusion, under the conditions described no increase in the number of MNE or MNPCE was observed in the peripheral blood of PNBs exposed to blue light phototherapy.

Differences in Salivary Flow Level, Xerostomia, and Flavor Alteration in Mexican HIV Patients Who Did or Did Not Receive Antiretroviral Therapy

Introduction. Objective and subjective alterations related to salivary flow have been reported in patients infected with human immunodeficiency virus (HIV), and these alterations are associated with the introduction of antiretroviral therapy. The aim of the current study was to discern whether these alterations are disease induced or secondary to drug therapy. Objective. The objective was to determine the relationships between low salivary flow, xerostomia, and flavor alterations in HIV patients who did or did not receive antiretroviral therapy. Materials and Methods. In this cross-sectional study, HIV patients were divided into two groups based on whether they had received antiretroviral therapy. Those patients with a previous diagnosis of any salivary gland disease were excluded. A survey was used to assess subjective variables, and colorimetry and salivary flow rates were measured using the Schirmer global test. Results. A total of 293 patients were included. The therapy group showed a significantly lower average salivary flow than did the group without therapy, and we observed that the flow rate tended to decrease after one year of therapy. The results were not conclusive, despite significant differences in xerostomia and flavor alteration between the groups. Conclusion. The study results suggest that antiretroviral therapy can cause cumulative damage that affects the amount of salivary flow.