RESUMEN
Preterm infants cannot counteract excessive reactive oxygen species (ROS) production due to preterm birth, leading to an excess of lipid peroxidation with malondialdehyde (MDA) production, capable of contributing to brain damage. Melatonin (ME), an endogenous brain hormone, and its metabolites, act as a free radical scavenger against ROS. Unfortunately, preterms have an impaired antioxidant system, resulting in the inability to produce and release ME. This prospective, multicenter, parallel groups, randomized, double-blind, placebo-controlled trial aimed to assess: (i) the endogenous production of ME in very preterm infants (gestational age ≤ 29 + 6 WE, 28 infants in the ME and 26 in the placebo group); (ii) the exogenous hormone availability and its metabolization to the main metabolite, 6-OH-ME after 15 days of ME oral treatment; (iii) difference of MDA plasma concentration, as peroxidation marker, after treatment. Blood was collected before the first administration (T1) and after 15 days of administration (T2). ME and 6-OH-ME were detected by liquid chromatography tandem mass spectrometry, MDA was measured by liquid chromatograph with fluorescence detection. ME and 6-OH-ME were not detectable in the placebo group at any study time-point. ME was absent in the active group at T1. In contrast, after oral administration, ME and 6-OH-ME resulted highly detectable and the difference between concentrations T2 versus T1 was statistically significant, as well as the difference between treated and placebo groups at T2. MDA levels seemed stable during the 15 days of treatment in both groups. Nevertheless, a trend in the percentage of neonates with reduced MDA concentration at T2/T1 was 48.1% in the ME group versus 38.5% in the placebo group. We demonstrated that very preterm infants are not able to produce endogenous detectable plasma levels of ME during their first days of life. Still, following ME oral administration, appreciable amounts of ME and 6-OH-ME were available. The trend of MDA reduction in the active group requires further clinical trials to fix the dosage, the length of ME therapy and to identify more appropriate indexes to demonstrate, at biological and clinical levels, the antioxidant activity and consequent neuroprotectant potential of ME in very preterm newborns.
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Melatonina , Nacimiento Prematuro , Femenino , Recién Nacido , Humanos , Antioxidantes/farmacología , Antioxidantes/metabolismo , Melatonina/uso terapéutico , Recien Nacido Prematuro , Especies Reactivas de Oxígeno , Neuroprotección , Estudios ProspectivosRESUMEN
BACKGROUND: This study aimed to assess the pharmacokinetic profile of 150 mg rifabutin (RBT) taken every other day (every 48 h) versus 300 mg RBT taken every other day (E.O.D), both in combination with lopinavir/ritonavir (LPV/r), in adult patients with human immunodeficiency virus (HIV) and tuberculosis (TB) co-infection. METHODS: This is a two-arm, open-label, pharmacokinetic, randomised study conducted in Burkina Faso between May 2013 and December 2015. Enrolled patients were randomised to receive either 150 mg RBT EOD (arm A, 9 subjects) or 300 mg RBT EOD (arm B, 7 subjects), both associated with LPV/r taken twice daily. RBT plasma concentrations were evaluated after 2 weeks of combined HIV and TB treatment. Samples were collected just before drug ingestion and at 1, 2, 3, 4, 6, 8, and 12 h after drug ingestion to measure plasma drug concentration using an HPLC-MS/MS assay. RESULTS: The Cmax and AUC0-12h medians in arm A (Cmax = 296 ng/mL, IQR: 205-45; AUC0-12h = 2528 ng.h/mL, IQR: 1684-2735) were lower than those in arm B (Cmax = 600 ng/mL, IQR: 403-717; AUC0-12h = 4042.5 ng.h/mL, IQR: 3469-5761), with a statistically significant difference in AUC0-12h (p = 0.044) but not in Cmax (p = 0.313). No significant differences were observed in Tmax (3 h versus 4 h). Five patients had a Cmax below the plasma therapeutic limit (< 300 ng/mL) in the 150 mg RBT arm, while the Cmax was above this threshold for all patients in the 300 mg RBT arm. Additionally, at 48 h after drug ingestion, all patients had a mycobacterial minimum inhibitory concentration (MIC) above the limit (> 64 ng/mL) in the 300 mg RBT arm, while 4/9 patients had such values in the 150 mg RBT arm. CONCLUSION: This study confirmed that the 150 mg dose of rifabutin ingested EOD in combination with LPV/r is inadequate and could lead to selection of rifamycin-resistant mycobacteria. TRIAL REGISTRATION: PACTR201310000629390, 28th October 2013.
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Infecciones Oportunistas Relacionadas con el SIDA/tratamiento farmacológico , Antibióticos Antituberculosos/administración & dosificación , Antibióticos Antituberculosos/uso terapéutico , Coinfección/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/uso terapéutico , Lopinavir/uso terapéutico , Rifabutina/administración & dosificación , Rifabutina/uso terapéutico , Ritonavir/uso terapéutico , Tuberculosis/tratamiento farmacológico , Adulto , Antibióticos Antituberculosos/efectos adversos , Antibióticos Antituberculosos/sangre , Burkina Faso , Cromatografía Líquida de Alta Presión , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Proyectos Piloto , Distribución Aleatoria , Rifabutina/efectos adversos , Rifabutina/sangre , Espectrometría de Masas en TándemRESUMEN
BACKGROUND: To evaluate the pharmacokinetic of plasma lopinavir (LPV) and ritonavir (RTV) when co-administered with three times weekly (TPW) rifabutin (RBT) at a dose of either 150 or 300 mg in African tuberculosis (TB) and HIV co-infected adult patients. METHODS: This is a pharmacokinetic study conducted in Ouagadougou among patients treated with a standard dosage of LPV/RTV 400/100 mg twice daily and RBT 150 mg TPW (arm A = 9 patients) or rifabutin 300 mg TPW (arm B = 7 patients) based regimens. Patients were recruited from the Bogodogo and Kossodo district hospitals in Ouagadougou from May 2013 to December 2015. Study inclusion criteria were that the patients were between 18 and 60 years of age, HIV-1 infected with pulmonary tuberculosis confirmed or suspected. Subsequent blood samples for pharmacokinetic monitoring were collected at 1, 2, 3, 4, 6, 8 and 12 h after combined drug ingestion for plasma drug monitoring using HPLC/MS assays. RESULTS: The medians LPV Cmax and Tmax were respectively, 20 µg/mL and 4 h for the RBT 150 mg group (arm A) and 7.7 µg/mL and 3 h for the RBT 300 mg group (arm B). The AUC0-12 of LPV was 111.8 µg h/mL in patients belonging to arm A versus 69.9 µg/mL for those in arm B (p = 0.313). The C0 of LPV was lower than 4 µg/mL in three patients receiving RBT 300 mg. Of note, the RTV plasma concentrations were nearly halved among patients on RBT 300 mg compared to those on lower RBT doses. The AUC0-12 of RTV in arm A was 12.7 µg h/mL versus 6.6 µg h/ml in arm B (p = 0.313). CONCLUSION: In our study, the pharmacokinetic of LPV and RTV was found to be highly variable when coadministrated with RBT 150 mg or 300 mg three times per week. There is a need for specific large study to verify clinical and virological effects of this variation, especially when coadministrated with RBT of 300 mg TPW, and to prevent viral resistance in response to under-dosing of LPV. Trial registration PACTR201310000629390. Registered 28 October 2013, http://www.pactr.org/.
Asunto(s)
Coinfección/tratamiento farmacológico , Infecciones por VIH/tratamiento farmacológico , Lopinavir/farmacocinética , Ritonavir/farmacocinética , Tuberculosis/tratamiento farmacológico , Adolescente , Adulto , Fármacos Anti-VIH/uso terapéutico , Burkina Faso , Femenino , VIH-1 , Humanos , Lopinavir/sangre , Masculino , Persona de Mediana Edad , Rifabutina/administración & dosificación , Rifabutina/uso terapéutico , Ritonavir/sangre , Adulto JovenRESUMEN
PFAS (perfluoroalkyl substances) are considered non-genotoxic. However, PFAS exposure has been associated with the induction of oxidative stress in vitro and in vivo, and the possible induction of indirect genotoxic effects under sustained PFAS exposure has not been investigated. In order to shed light on this aspect, in this study a comprehensive assessment of genotoxicity was carried out in mice administered with perfluorooctanoic acid (PFOA, 0.1, 1 and 5â¯mg/kg body weight) and its C4 analogue perfluorobutyric acid (PFBA, 5â¯mg/kg body weight) for five weeks through drinking water. Markers of cell toxicity, oxidative stress and DNA strand breaks were measured in liver, the main target of toxicity of PFOA in rodents; systemic genotoxicity was also assessed by the analysis of micronuclei in reticulocytes and spleen lymphocytes, and germ cell effects by the Comet assay on testis cells. PFOA administration at the highest dose (5â¯mg/kg body weight) induced marked liver hypertrophy with signs of cell injury (elevated ALT and AST), with no concurrent evidence of lipid peroxidation and oxidative stress (decreased antioxidant capacity). Only mild liver hypertrophy, with no other signs of toxicity, was determined by PFBA administration. No evidence of treatment related genotoxicity was observed in any experimental group. Overall, data indicate that under the experimental conditions of this study, severe liver toxicity induced by PFOA administration is not associated with oxidative stress. Accordingly, no genotoxic effect is observed in liver and in the other tissues examined. Milder evidence of liver toxicity, with no genotoxicity, and a lower tendency to bioaccumulation were observed in PFBA treated mice.
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Caprilatos/administración & dosificación , Caprilatos/toxicidad , Fluorocarburos/administración & dosificación , Fluorocarburos/toxicidad , Pruebas de Mutagenicidad , Administración Oral , Animales , Hígado/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: Numerous health benefits have been attributed to the Ginkgo biloba leaf extract (GBLE), one of the most extensively used phytopharmaceutical drugs worldwide. Recently, concerns of the safety of the extract have been raised after a report from US National Toxicology Program (NTP) claimed high doses of GBLE increased liver and thyroid cancer incidence in mice and rats. A safety study has been designed to assess, in a population of elderly residents in nursing homes, clinical and genomic risks associated to GBLE treatment. METHODS: GiBiEx is a multicentre randomized clinical trial, placebo controlled, double blinded, which compared subjects randomized to twice-daily doses of either 120-mg of IDN 5933 (also known as Ginkgoselect®Plus) or to placebo for a 6-months period. IDN 5933 is extracted from dried leaves and contains 24.3% flavone glycosides and 6.1% of terpene lactones (2.9% bilobalide, 1.38% ginkgolide A, 0.66% ginkgolide B, 1.12% ginkgolide C) as determined by HPLC. The study was completed by 47 subjects, 20 in the placebo group and 27 in the treatment group. Clinical (adverse clinical effect and liver injury) and genomic (micronucleus frequency, comet assay, c-myc, p53, and ctnnb1 expression profile in lymphocytes) endpoints were assessed at the start and at the end of the study. RESULTS: No adverse clinical effects or increase of liver injury markers were reported in the treatment group. The frequency of micronuclei [Mean Ratio (MR) = 1.01, 95% Confidence Intervals (95% CI) 0.86-1.18), and DNA breaks (comet assay) (MR = 0.91; 95% CI 0.58-1.43), did not differ in the two study groups. No significant difference was found in the expression profile of the three genes investigated. CONCLUSIONS: None of the markers investigated revealed a higher risk in the treatment group, supporting the safety of IDN 5933 at doses prescribed and for duration of six months. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03004508 , December 20, 2016. Trial retrospectively registered.
Asunto(s)
Daño del ADN/efectos de los fármacos , Ginkgo biloba/química , Extractos Vegetales , Hojas de la Planta/química , Anciano , Anciano de 80 o más Años , Femenino , Genoma/efectos de los fármacos , Humanos , Hígado/efectos de los fármacos , Pruebas de Función Hepática , Masculino , Pruebas de Micronúcleos , Extractos Vegetales/administración & dosificación , Extractos Vegetales/efectos adversos , Extractos Vegetales/farmacologíaRESUMEN
In the course of a 2-year combined chronic toxicity-carcinogenicity study performed according to Organisation for Economic Co-operation and Development (OECD) Test Guideline 453, systemic (blood cell) genotoxicity of two OECD representative nanomaterials, CeO2 NM-212 and BaSO4 upon 3- or 6-month inhalation exposure to rats was assessed. DNA effects were analysed in leukocytes using the alkaline Comet assay, gene mutations and chromosome aberrations were measured in erythrocytes using the flow cytometric Pig-a gene mutation assay and the micronucleus test (applying both microscopic and flow cytometric evaluation), respectively. Since nano-sized CeO2 elicited lung effects at concentrations of 5mg/m3 (burdens of 0.5mg/lung) in the preceding range-finding study, whereas nano-sized BaSO4 did not induce any effect, female rats were exposed to aerosol concentrations of 0.1 up to 3mg/m3 CeO2 or 50mg/m3 BaSO4 nanomaterials (6h/day; 5 days/week; whole-body exposure). The blood of animals treated with clean air served as negative control, whereas blood samples from rats treated orally with three doses of 20mg/kg body weight ethylnitrosourea at 24h intervals were used as positive controls. As expected, ethylnitrosourea elicited significant genotoxicity in the alkaline Comet and Pig-a gene mutation assays and in the micronucleus test. By contrast, 3- and 6-month CeO2 or BaSO4 nanomaterial inhalation exposure did not elicit significant findings in any of the genotoxicity tests. The results demonstrate that subchronic inhalation exposure to different low doses of CeO2 or to a high dose of BaSO4 nanomaterials does not induce genotoxicity on the rat hematopoietic system at the DNA, gene or chromosome levels.
Asunto(s)
Aberraciones Cromosómicas/inducido químicamente , Daño del ADN , Exposición por Inhalación , Leucocitos/efectos de los fármacos , Mutación , Nanoestructuras/toxicidad , Animales , Sulfato de Bario/farmacología , Sulfato de Bario/toxicidad , Cerio/farmacología , Cerio/toxicidad , ADN/efectos de los fármacos , Femenino , Leucocitos/metabolismo , Pruebas de Mutagenicidad , Nanoestructuras/química , RatasRESUMEN
BACKGROUND: The World Health Organization is coordinating an international project aimed at systematically reviewing the evidence regarding the association between radiofrequency electromagnetic field (RF-EMF) exposure and adverse health effects. Reproductive health outcomes have been identified among the priority topics to be addressed. OBJECTIVES: To evaluate the effect of RF-EMF exposure on male fertility of experimental mammals and on human sperm exposed in vitro. METHODS: Three electronic databases (PubMed, Scopus and EMF Portal) were last searched on September 17, 2022. Two independent reviewers screened the studies, which were considered eligible if met the following criteria: 1) Peer-reviewed publications of sham controlled experimental studies, 2) Non-human male mammals exposed at any stage of development or human sperm exposed in vitro, 3) RF-EMF exposure within the frequency range of 100 kHz-300 GHz, including electromagnetic pulses (EMP), 4) one of the following indicators of reproductive system impairment:Two reviewers extracted study characteristics and outcome data. We assessed risk of bias (RoB) using the Office of Health Assessment and Translation (OHAT) guidelines. We categorized studies into 3 levels of overall RoB: low, some or high concern. We pooled study results in a random effects meta-analysis comparing average exposure to no-exposure and in a dose-response meta-analysis using all exposure doses. For experimental animal studies, we conducted subgroup analyses for species, Specific Absorption Rate (SAR) and temperature increase. We grouped studies on human sperm exposed in vitro by the fertility status of sample donors and SAR. We assessed the certainty of the evidence using the GRADE approach after excluding studies that were rated as "high concern" for RoB. RESULTS: One-hundred and seventeen papers on animal studies and 10 papers on human sperm exposed in vitro were included in this review. Only few studies were rated as "low concern" because most studies were at RoB for exposure and/or outcome assessment. Subgrouping the experimental animal studies by species, SAR, and temperature increase partly accounted for the heterogeneity of individual studies in about one third of the meta-analyses. In no case was it possible to conduct a subgroup analysis of the few human sperm in vitro studies because there were always 1 or more groups including less than 3 studies. Among all the considered endpoints, the meta-analyses of animal studies provided evidence of adverse effects of RF-EMF exposure in all cases but the rate of infertile males and the size of the sired litters. The assessment of certainty according to the GRADE methodology assigned a moderate certainty to the reduction of pregnancy rate and to the evidence of no-effect on litter size, a low certainty to the reduction of sperm count, and a very low certainty to all the other meta-analysis results. Studies on human sperm exposed in vitro indicated a small detrimental effect of RF-EMF exposure on vitality and no-effect on DNA/chromatin alterations. According to GRADE, a very low certainty was attributed to these results. The few studies that used EMP exposure did not show effects on the outcomes. A low to very low certainty was attributed to these results. DISCUSSION: Many of the studies examined suffered of severe limitations that led to the attribution of uncertainty to the results of the meta-analyses and did not allow to draw firm conclusions on most of the endpoints. Nevertheless, the associations between RF-EMF exposure and decrease of pregnancy rate and sperm count, to which moderate and low certainty were attributed, are not negligible, also in view of the indications that in Western countries human male fertility potential seems to be progressively declining. It was beyond the scope of our systematic review to determine the shape of the dose-response relationship or to identify a minimum effective exposure level. The subgroup and the dose-response fitting analyses did not show a consistent relationship between the exposure levels and the observed effects. Notably, most studies evaluated RF-EMF exposure levels that were higher than the levels to which human populations are typically exposed, and the limits set in international guidelines. For these reasons we cannot provide suggestions to confirm or reconsider current human exposure limits. Considering the outcomes of this systematic review and taking into account the limitations found in several of the studies, we suggest that further investigations with better characterization of exposure and dosimetry including several exposure levels and blinded outcome assessment were conducted. PROTOCOL REGISTRATION: Protocols for the systematic reviews of animal studies and of human sperm in vitro studies were published in Pacchierotti et al., 2021. The former was also registered in PROSPERO (CRD42021227729 https://www.crd.york.ac.uk/prospero/display_record.php?RecordID = 227729) and the latter in Open Science Framework (OSF Registration DOI https://doi.org/10.17605/OSF.IO/7MUS3).
Asunto(s)
Campos Electromagnéticos , Infertilidad Masculina , Semen , Animales , Humanos , Masculino , Campos Electromagnéticos/efectos adversos , Mamíferos , Ondas de Radio/efectos adversos , Reproducción , Semen/efectos de la radiación , Infertilidad Masculina/etiologíaRESUMEN
BACKGROUND: There is no consensus on darunavir (DRV) target levels in plasma for clinical use, and information about variability in plasma concentrations is limited. AIM: : To investigate the variability in DRV plasma trough concentrations in the clinical setting, evaluating interindividual and intraindividual variabilities of plasma drug levels among HIV-infected patients receiving ritonavir (RTV)-boosted DRV (DRV/r) within salvage regimens, and evaluate the potential correlation between variability and virological response. METHODS: Sixty-two patients taking DRV/r (600/100 mg twice a day) were evaluated for trough plasma concentrations and immunovirological parameters after 6 months from the start of the regimen. A subgroup of patients (n = 21) was also evaluated for intraindividual variability (expressed as coefficient of variation) on 2 samples taken at different time points. Drug concentrations were assayed by high-performance liquid chromatography with ultraviolet detection, and the values were expressed as medians with interquartile range (IQR). Genotypic sensitivity score and genotypic inhibitory quotient were calculated. RESULTS: DRV/r was used with a median of 3 other antiretroviral drugs (raltegravir use 88.7%). Median plasma concentrations were 3.22 mcg/mL (IQR, 2.04-5.69) for DRV and 0.44 mcg/mL (IQR, 0.21-0.70) for RTV. Both drugs showed a high interindividual variability in plasma concentrations (61% and 99.3%, respectively). Only 3 patients (4.8%) had undetectable DRV plasma levels. DRV plasma concentrations showed a significant positive correlation with age (r = 0.298, P = 0.019), but no significant correlation between DRV genotypic inhibitory quotient and HIV-RNA plasma levels (P = 0.614) was found. Intraindividual coefficients of variation were 58.4% for DRV and 47.1% for RTV. Patients with undetectable HIV-RNA showed a trend for lower intraindividual coefficients of variation compared with patients with detectable HIV-RNA (55.9% versus 83.8%, P = 0.156). No major interaction effects with other antiretroviral drugs were found. CONCLUSIONS: In a context of salvage therapy, both DRV and RTV plasma levels showed high interindividual and intraindividual variabilities. Lower intraindividual variability could be beneficial in maintaining viral suppression.
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Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/sangre , Ritonavir/sangre , Sulfonamidas/sangre , Adulto , Anciano , Cromatografía Líquida de Alta Presión/métodos , Darunavir , Quimioterapia Combinada , Femenino , Genotipo , Inhibidores de la Proteasa del VIH/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , ARN Viral/sangre , Ritonavir/uso terapéutico , Terapia Recuperativa , Sulfonamidas/uso terapéutico , Factores de Tiempo , Adulto JovenRESUMEN
Poly(ADP-ribose)polymerase-1 (PARP1) is a nuclear protein implicated in DNA repair, recombination, replication, and chromatin remodeling. The aim of this study was to evaluate possible differences between PARP1(-/-) and wild-type mice regarding induction and repair of DNA lesions in irradiated male germ cells. Comet assay was applied to detect DNA damage in testicular cells immediately, and two hours after 4 Gy X-ray irradiation. A similar level of spontaneous and radiation-induced DNA damage was observed in PARP1(-/-) and wild-type mice. Conversely, two hours after irradiation, a significant level of residual damage was observed in PARP1(-/-) cells only. This finding was particularly evident in round spermatids. To evaluate if PARP1 had also a role in the dynamics of H2AX phosphorylation in round spermatids, in which γ-H2AX foci had been shown to persist after completion of DNA repair, we carried out a parallel analysis of γ-H2AX foci at 0.5, 2, and 48 h after irradiation in wild-type and PARP1(-/-) mice. No evidence was obtained of an effect of PARP1 depletion on H2AX phosphorylation induction and removal. Our results suggest that, in round spermatids, under the tested experimental conditions, PARP1 has a role in radiation-induced DNA damage repair rather than in long-term chromatin modifications signaled by phosphorylated H2AX.
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Daño del ADN/efectos de la radiación , Reparación del ADN/efectos de la radiación , Células Germinativas/metabolismo , Células Germinativas/efectos de la radiación , Poli(ADP-Ribosa) Polimerasas/metabolismo , Rayos X/efectos adversos , Animales , Ensayo Cometa , Citometría de Flujo , Histonas , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilación , Poli(ADP-Ribosa) Polimerasa-1 , Poli(ADP-Ribosa) Polimerasas/genéticaRESUMEN
The increasing exposure of the human population to radiofrequency electromagnetic fields has increased concern about its possible health effects. The aim of this systematic review is to provide an update of the state of the research on this topic, through a quantitative analysis, to assess the increased risk of tumor incidence in laboratory animals (rodents) without limitations of species, strain, sex or genotype. The review was conducted according to the PRISMA guideline and individual studies were assessed by referring to the OHAT Risk of Bias Rating Tool for Human and Animal Studies. A total of 27 studies were considered eligible for the evaluation of tumor incidence; a meta-analysis was carried out on 23 studies to assess the possible increased risk of both malignant and benign tumors onset at the systemic level or in different organs/tissues. A significant association between exposure to RF and the increased/decreased risk of cancer does not result from the meta-analysis in most of considered tissues. A significant increased/decreased risk can be numerically observed only in heart, CNS/brain, and intestine for malignant tumors. Nevertheless, the assessment of the body of evidence attributes low or inadequate evidence for an association between RF exposure and the onset of neoplasm in all tissues.
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Campos Electromagnéticos , Neoplasias , Animales , Humanos , Campos Electromagnéticos/efectos adversos , Ondas de Radio/efectos adversos , Neoplasias/epidemiología , Neoplasias/etiología , Encéfalo , IncidenciaRESUMEN
BACKGROUND: The World Health Organization is coordinating an international project aimed at systematically reviewing the evidence regarding the association between radiofrequency electromagnetic field (RF-EMF) exposure and adverse health effects. Within the project, 6 topics have been prioritized by an expert group, which include reproductive health outcomes. OBJECTIVES: According to the protocol published in 2021, a systematic review and meta-analyses on the adverse effects of RF-EMF exposure during pregnancy in offspring of experimental animals were conducted. METHODS: Three electronic databases (PubMed, Scopus and EMF Portal) were last searched on September 8 or 17, 2022. Based on predefined selection criteria, the obtained references were screened by two independent reviewers. Studies were included if they met the following criteria: 1) original, sham controlled experimental study on non-human mammals exposed in utero, published in peer-reviewed journals, 2) the experimental RF-EMF exposure was within the frequency range 100 kHz-300 GHz, 3) the effects of RF-EMF exposure on fecundity (litter size, embryonic/fetal losses), on the offspring health at birth (decrease of weight or length, congenital malformations, changes of sex ratio) or on delayed effects (neurocognitive alterations, female infertility or early-onset cancer) were studied. Study characteristics and outcome data were extracted by two reviewers. Risk of bias (RoB) was assessed using the Office of Health Assessment and Translation (OHAT) guidelines. Study results were pooled in a random effects meta-analysis comparing average exposure to no-exposure and in a dose-response meta-analysis using all exposure doses, after exclusion of studies that were rated at "high concern" for RoB. Subgroup analyses were conducted for species, Specific Absorption Rate (SAR) and temperature increase. The certainty of the evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. RESULTS: Eighty-eight papers could be included in this review. Effects on fecundity. The meta-analysis of studies on litter size, conducted at a whole-body average SAR of 4.92 W/kg, did not show an effect of RF-EMF exposure (MD 0.05; 95% CI -0.21 to 0.30). The meta-analysis of studies on resorbed and dead fetuses, conducted at a whole-body average SAR of 20.26 W/kg, showed a significant increase of the incidence in RF-EMF exposed animals (OR 1.84; 95% CI 1.27 to 2.66). The results were similar in the dose-response analysis. Effects on the offspring health at birth. The meta-analysis of studies on fetal weight, conducted at a whole-body average SAR of 9.83 W/kg, showed a small decrease in RF-EMF exposed animals (SMD 0.31; 95% CI 0.15 to 0.48). The meta-analysis of studies on fetal length, conducted at a whole-body average SAR of 4.55 W/kg, showed a moderate decrease in length at birth (SMD 0.45; 95% CI 0.07 to 0.83). The meta-analysis of studies on the percentage of fetuses with malformations, conducted at a whole-body average SAR of 6.75 W/kg, showed a moderate increase in RF-EMF exposed animals (SMD -0.45; 95% CI -0.68 to -0.23). The meta-analysis of studies on the incidence of litters with malformed fetuses, conducted at a whole-body average SAR of 16.63 W/kg, showed a statistically significant detrimental RF-EMF effect (OR 3.22; 95% CI 1.9 to 5.46). The results were similar in the dose-response analyses. Delayed effects on the offspring health. RF-EMF exposure was not associated with detrimental effects on brain weight (SMD 0.10; 95% CI -0.09 to 0.29) and on learning and memory functions (SMD -0.54; 95% CI -1.24 to 0.17). RF-EMF exposure was associated with a large detrimental effect on motor activity functions (SMD 0.79; 95% CI 0.21 to 1.38) and a moderate detrimental effect on motor and sensory functions (SMD -0.66; 95% CI -1.18 to -0.14). RF-EMF exposure was not associated with a decrease of the size of litters conceived by F2 female offspring (SMD 0.08; 95% CI -0.39 to 0.55). Notably, meta-analyses of neurobehavioural effects were based on few studies, which suffered of lack of independent replication deriving from only few laboratories. DISCUSSION: There was high certainty in the evidence for a lack of association of RF-EMF exposure with litter size. We attributed a moderate certainty to the evidence of a small detrimental effect on fetal weight. We also attributed a moderate certainty to the evidence of a lack of delayed effects on the offspring brain weight. For most of the other endpoints assessed by the meta-analyses, detrimental RF-EMF effects were shown, however the evidence was attributed a low or very low certainty. The body of evidence had limitations that did not allow an assessment of whether RF-EMF may affect pregnancy outcomes at exposure levels below those eliciting a well-known adverse heating impact. In conclusion, in utero RF-EMF exposure does not have a detrimental effect on fecundity and likely affects offspring health at birth, based on the meta-analysis of studies in experimental mammals on litter size and fetal weight, respectively. Regarding possible delayed effects of in utero exposure, RF-EMF probably does not affect offspring brain weight and may not decrease female offspring fertility; on the other hand, RF-EMF may have a detrimental impact on neurobehavioural functions, varying in magnitude for different endpoints, but these last findings are very uncertain. Further research is needed on the effects at birth and delayed effects with sample sizes adequate for detecting a small effect. Future studies should use standardized endpoints for testing prenatal developmental toxicity and developmental neurotoxicity (OECD TG 414 and 426), improve the description of the exposure system design and exposure conditions, conduct appropriate dosimetry characterization, blind endpoint analysis and include several exposure levels to better enable the assessment of a dose-response relationship. PROTOCOL REGISTRATION AND PUBLICATION: The protocol was published in Pacchierotti et al., 2021 and registered in PROSPERO CRD42021227746 (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=227746).
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Campos Electromagnéticos , Peso Fetal , Embarazo , Animales , Femenino , Campos Electromagnéticos/efectos adversos , Reproducción , Fertilidad , MamíferosRESUMEN
OBJECTIVES: To evaluate the pharmacokinetic profile of ritonavir-boosted lopinavir in HIV-infected patients during rifabutin-based anti-mycobacterial therapy. PATIENTS AND METHODS: A longitudinal, cross-over pharmacokinetic evaluation of lopinavir with and without rifabutin in HIV-infected subjects with mycobacterial disease was done. All received lopinavir/ritonavir (400/100 mg twice a day)â+âan adjusted rifabutin dose of 150 mg every other day. Twelve-hour lopinavir pharmacokinetic sampling occurred at 2 weeks (T1) and 6 weeks (T2) after starting combined therapy and 10 weeks after completion of adjusted rifabutin (T3). Plasma was assayed using an HPLC method; lopinavir plasma concentration-time data were analysed using non-compartmental methods. RESULTS: In 10 patients with complete lopinavir curves at T1, T2 and T3 pharmacokinetic values were, respectively: AUC(0-12), 187.5, 161.8 and 121.1 µgâ·âh/mL; C(trough), 13.2, 10.0 and 7.7 µg/mL; C(max), 18.7, 15.9 and 13.3 µg/mL; and apparent oral clearance (CL/F), 0.035, 0.037 and 0.045 L/h/kg. Lopinavir C(trough) and AUC(0-12) were significantly higher at T1 compared with T3 while CL/F remained unchanged throughout. Combined treatment was well tolerated and none of the patients experienced moderate to severe lopinavir-related adverse events. CONCLUSIONS: Lopinavir serum concentrations are not reduced when the drug is administered together with an adjusted dose of 150 mg of rifabutin every other day.
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Fármacos Anti-VIH/farmacocinética , Antituberculosos/administración & dosificación , Infecciones por VIH/tratamiento farmacológico , Lopinavir/farmacocinética , Rifabutina/administración & dosificación , Tuberculosis/tratamiento farmacológico , Adulto , Fármacos Anti-VIH/administración & dosificación , Cromatografía Líquida de Alta Presión , Interacciones Farmacológicas , Femenino , Infecciones por VIH/complicaciones , Humanos , Lopinavir/administración & dosificación , Masculino , Persona de Mediana Edad , Plasma/química , Ritonavir/administración & dosificación , Tuberculosis/complicacionesRESUMEN
OBJECTIVES: Low plasma concentrations of rifampicin, an essential antituberculosis drug, have been reported particularly among HIV co-infected persons. In a prospective, longitudinal study we measured rifampicin systemic exposure at different timepoints during highly active antiretroviral therapy (HAART). PATIENTS AND METHODS: From May 2006 to April 2007, 16 tuberculosis (TB)/HIV co-infected patients were enrolled in Ouagadougou, Burkina Faso. All patients received fixed dose combinations of rifampicin, isoniazid, pyrazinamide and ethambutol under direct observation and HAART, consisting of a fixed dose combination of stavudine, lamivudine and nevirapine. Rifampicin concentrations during the dosing interval were determined by HPLC at three different timepoints: (i) after 2 weeks of TB therapy and before starting HIV therapy (T0); (ii) after 4 weeks of combined therapy (T1); and (iii) after 10 weeks of combined therapy (T2). RESULTS: The median values of the area under the curve (AUC(0-24)) of rifampicin increased by 39% at T1 (15.69 µgâ·âh/mL; P = 0.01) and by 83% at T2 (20.65 µgâ·âh/mL; P = 0.001) compared with T0 (11.28 µgâ·âh/mL). Similar variations were observed for the median C(max) at T0 (2.24 µg/mL) compared with T2 (2.83 µg/mL; P = 0.003). However, none of the subjects had C(max) levels >8 µg/mL at either T0 or T2. CONCLUSIONS: Rifampicin systemic exposure increased during combined TB and HIV therapy, possibly due to increased drug absorption or decreased oral clearance, but remained invariably low in this population. Studies to define the C(max) rifampicin concentrations, which are associated with a significantly increased risk of treatment failure, are urgently warranted.
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Fármacos Anti-VIH/administración & dosificación , Terapia Antirretroviral Altamente Activa/métodos , Antituberculosos/farmacocinética , Infecciones por VIH/tratamiento farmacológico , Rifampin/farmacocinética , Tuberculosis/tratamiento farmacológico , Adulto , Antituberculosos/administración & dosificación , Burkina Faso , Cromatografía Líquida de Alta Presión , Etambutol/administración & dosificación , Femenino , Infecciones por VIH/complicaciones , Humanos , Isoniazida/administración & dosificación , Masculino , Persona de Mediana Edad , Plasma/química , Pirazinamida/administración & dosificación , Rifampin/administración & dosificación , Tuberculosis/complicacionesRESUMEN
BACKGROUND: Human cytomegalovirus (HCMV) infection of the central nervous system (CNS) is a rare but life threatening condition which may follow hematopoietic stem cell transplantation. Diagnosis, monitoring and treatment approaches rely on anecdotal reports. CASE PRESENTATIONS: The different outcomes of HCMV CNS disease in an adult and a pediatric T-cell depleted hematopoietic stem cell transplant (HSCT) recipient are reported. In the first case, HCMV encephalitis emerged in the context of simultaneous impairment of the T- and B-cell immunity. Antiviral treatment only reduced viral load in peripheral blood and the patient died. In the second case, an HCMV radiculopathy was observed and antiviral treatment was adjusted on the basis of intrathecal drug level. In addition, donor HCMV-specific cytotoxic T lymphocytes (CTLs) were infused. Viral load in the CNS decreased and the patient recovered from the acute event. In neither case were drug-resistant HCMV variants observed in blood or CNS samples. CONCLUSIONS: T-cell depleted HSCT appears a predisposing condition for CNS HCMV infection since never observed in other HSCT recipients at our center in the last 15 years. Intensive diagnostic approaches and timely aggressive combination treatments might improve clinical outcome in these patients.
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Antivirales/administración & dosificación , Infecciones por Citomegalovirus/patología , Encefalitis Viral/patología , Trasplante de Células Madre Hematopoyéticas , Radiculopatía/patología , Traslado Adoptivo , Sangre/virología , Líquido Cefalorraquídeo/virología , Preescolar , Infecciones por Citomegalovirus/tratamiento farmacológico , Encefalitis Viral/tratamiento farmacológico , Resultado Fatal , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiculopatía/tratamiento farmacológico , Linfocitos T Citotóxicos/inmunología , Resultado del Tratamiento , Carga ViralRESUMEN
BACKGROUND: An Italian project aims to review the scientific literature on the possible carcinogenicity of radiofrequency (100 kHz-300 GHz) electromagnetic field (RF-EMF) exposure. The ENEA team has to carry out a systematic review of the in vivo studies on this topic. OBJECTIVES: Development of a protocol for a systematic review (meta-analysis included) to investigate the potential carcinogenic risk following RF-EMF in vivo exposure to doses above or within legal limits. The aims of this review are (1) to provide a descriptive and, if possible, a quantitative summary of the results of the examined RF-EMF in vivo studies, together with an assessment of the consistency of observations and of the causes of heterogeneity, and (2) to assess the weight of evidence to support or refute the hypothesis of carcinogenic effects caused by RF-EMF exposure and to draw conclusions about the potential for carcinogenicity of RF-EMF exposure. METHODS: We will search for relevant studies in electronic academic databases and in the reference list of selected papers and reviews on the topic, including the descriptive reviews on RF-EMF carcinogenic effect carried out by international panels of experts since 2011. The following elements of the PECO question were defined: experimental studies on rodents of both sexes, all ages and species, all genetic backgrounds (Population) exposed to RF-EMF alone, or in combination with other physical or chemical agents (Exposure); only studies reporting outcome data in exposed and sham control groups (Comparison); and all types of cancer with all tumor-related outcome measures (Outcome) will be included. Only peer-reviewed articles written in English will be considered without limit in the publication date. Eligibility criteria were defined for papers to be included. A risk of bias assessment will be performed using a tool specifically developed for animal studies. A meta-analysis will be performed, if feasible, for all outcome measures; for subgroup analysis, a minimum of 3 studies per subgroup will be required. If meta-analysis will not be possible, a narrative synthesis of the results will be reported. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020191105 HIGHLIGHTS: An Italian collaborative research agreement aims to review the scientific literature on the possible carcinogenicity of RF-EMF (100 kHz - 300 GHz). The ENEA team will systematically review and, if possible, meta-analyse estimates the effects of in vivo exposure to RF-EMF exposure on cancer. The ENEA group is a multidisciplinary team of researchers with a consolidated experience both in carcinogenicity experiments and radiofrequency dosimetric assessment. The proposed protocol uses the NTP OHAT Approach for Systematic Review as an organizing framework. The proposed protocol aims to lead to the first systematic review providing a strength of evidence assessment on this topic.
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Campos Electromagnéticos , Neoplasias , Animales , Campos Electromagnéticos/efectos adversos , Femenino , Masculino , Metaanálisis como Asunto , Evaluación de Resultado en la Atención de Salud , Ondas de Radio/efectos adversos , Proyectos de Investigación , Revisiones Sistemáticas como AsuntoRESUMEN
The genotoxicity of nano-structured synthetic amorphous silica (SAS), a common food additive, was investigated in vivo in rats. A 90-day oral toxicity study was performed according to OECD test guideline 408 and the genotoxicity of pyrogenic SAS nanomaterial NM-203 was assessed in several organs, using complementary tests. Adult Sprague-Dawley rats of both sexes were treated orally for 90 days with 0, 2, 5, 10, 20, or 50 mg SAS/kg bw per day. Dose levels were selected to approximate expected human dietary exposures to SAS. DNA strand breaks were evaluated by the comet assay in blood, bone marrow, liver, and spleen according to OECD test guideline 489; mutations induced in bone marrow precursors of erythrocytes were assessed by the Pig-a assay and chromosome/ genome damage by the micronucleus assay in blood (OECD test guideline 474) and colon. No treatment-related increases of gene (Pig-a) or chromosome/genome (micronucleus) mutations were detected in the blood. The percentage of micronucleated cells was not increased in the colon of treated rats. Among the organs analyzed by the comet assay, the spleen was the only target showing a weak but biologically relevant genotoxic effect.
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Daño del ADN , Dióxido de Silicio , Animales , Ensayo Cometa , Femenino , Masculino , Pruebas de Micronúcleos , Ratas , Ratas Sprague-Dawley , Dióxido de Silicio/toxicidadRESUMEN
BACKGROUND: Adequate plasma trough concentrations (Ctrough) of protease inhibitors are required to maintain antiviral activity throughout the dosing interval. Therapeutic drug monitoring is used in clinical practice to optimize dosage and avoid toxic or subtherapeutic drug exposure. The pharmacokinetic variability of Atazanavir (ATV) can be relatively large, as a result of several factors. One of the affecting factors may be hepatic impairment due to hepatitis C virus (HCV) coinfection. METHODS: We collected trough plasma samples from human immunodeficiency virus (HIV)-1-infected outpatients, with and without HCV coinfection and/or cirrhosis, receiving stable highly active antiretroviral therapy containing ATV. In the total population, we mainly compared the 2 regimens: 300ATV + 100RTV OD [ritonavir (RTV), once daily (OD)] versus 400ATV OD. We used a threshold value of 0.15 µg/mL, based on the proposed therapeutic range (0.15-0.85 µg/mL). Plasma concentrations of ATV were determined by a validated assay using high-performance liquid chromatography with ultraviolet detection. A total of 214 HIV-infected outpatients were included. For each regimen, we compared 3 groups of subjects: HIV+/HCV-, HIV+/HCV+, and HIV+/HCV+ with cirrhosis. RESULTS: In the whole study population, we observed a large variability and found suboptimal Ctrough levels (<0.15 µg/mL) in 23 subjects (2 belonging to the 300/100 OD group and 21 to the 400 OD group). For the standard dosage regimen of 300ATV + 100RTV OD, we did not find a statistical difference between HIV-infected patients without HCV coinfection versus HIV-infected patients with HCV coinfection: median 0.85 (interquartile range 0.53-1.34) and 0.95 (0.70-1.36) µg/mL, respectively. In HIV+/HCV+-infected patients with cirrhosis, we found a median Ctrough of 0.70 (0.43-1.0) µg/mL, with no statistical difference when compared with HIV+/HCV- infected patients. For the 400ATV OD (n=90) dosage regimen, the total median ATV Ctrough was 0.40 (0.23-1.0) µg/mL. In this group, we found a statistically significant difference between HIV+/HCV- and HIV+/HCV+-infected patients: median Ctrough was 0.23 (0.11-0.42) and 0.52 (0.20-1.0) µg/mL, respectively. In HIV+/HCV+ subjects with cirrhosis, the Ctrough median value was 0.42 (0.13-0.75) µg/mL, and there was a significant difference when compared with HIV patients without coinfection. CONCLUSIONS: Therapeutic drug monitoring of ATV in patients receiving unboosted regimen may be useful to identify those HIV-infected subjects, with or without HCV coinfection, who may benefit from adding low RTV doses, or the subset of patients in whom removal of RTV could be attempted without the risk of suboptimal plasma ATV exposure.
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Infecciones por VIH/sangre , Infecciones por VIH/tratamiento farmacológico , Inhibidores de la Proteasa del VIH/administración & dosificación , Hepatitis C/sangre , Oligopéptidos/administración & dosificación , Oligopéptidos/sangre , Piridinas/administración & dosificación , Piridinas/sangre , Adulto , Terapia Antirretroviral Altamente Activa/métodos , Sulfato de Atazanavir , Monitoreo de Drogas/métodos , Femenino , Fibrosis/sangre , Fibrosis/virología , VIH/aislamiento & purificación , Infecciones por VIH/virología , Inhibidores de la Proteasa del VIH/sangre , Inhibidores de la Proteasa del VIH/farmacocinética , Hepacivirus/aislamiento & purificación , Hepatitis C/virología , Humanos , Masculino , Persona de Mediana Edad , Oligopéptidos/farmacocinética , Piridinas/farmacocinética , Estudios Retrospectivos , Ritonavir/uso terapéuticoRESUMEN
Synthetic amorphous silica (SAS) consists of agglomerates and aggregates of primary particles in the nanorange (<100 nm) and it is the E551 authorized food additive. The potential risks for human health associated to dietary exposure to SAS are not completely assessed; in particular, data on male and female reproductive systems are lacking. A 90-day oral toxicity study with pyrogenic SAS nanomaterial NM-203 was carried out on the basis of the OECD test guideline 408 in the frame of the NANoREG project. Adult Sprague-Dawley rats of both sexes were orally treated for 90 days with 0, 2, 5, 10, 20 and 50 mg SAS/kg bw per day. Dose levels were selected to be as close as possible to the expected human exposure to food additive E551. The present paper provides specific information on potential effects on male and female reproductive systems, through the evaluation of serum biomarkers, sperm count, histopathological analysis of testis, epididymis, ovary and uterus and real-time PCR on uterus; potential genotoxic alterations were evaluated by comet assay on testis, sperm and ovary. NM-203 did not induce histophatological and genotoxic effects in male reproductive system. In female rats, ovary is not target of NM-203 and only tissue-specific effects on uterus were recorded up to 10 mg/kg bw per day. To our best knowledge, this is the first study providing data on male and female reproductive systems after long-term, repeated oral exposure at dose levels close to dietary human exposure, which identifies a limited concern only for female reproductive health.
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Dióxido de Silicio/toxicidad , Administración Oral , Animales , Ensayo Cometa , Estradiol/sangre , Femenino , Expresión Génica/efectos de los fármacos , Genitales/efectos de los fármacos , Genitales/metabolismo , Antígeno Ki-67/metabolismo , Masculino , Ratas Sprague-Dawley , Recuento de Espermatozoides , Testosterona/sangre , Pruebas de Toxicidad SubcrónicaRESUMEN
Sperm DNA damage may have adverse effects on reproductive outcome. Sperm DNA breaks can be detected by several tests, which evaluate DNA integrity from different and complementary perspectives and offer a new class of biomarkers of the male reproductive function and of its possible impairment after environmental exposure. The remodeling of sperm chromatin produces an extremely condensed nuclear structure protecting the nuclear genome from adverse environments. This nuclear remodeling is species specific, and differences in chromatin structure may lead to a dissimilar DNA susceptibility to mutagens among species. In this study, the capacity of the comet assay in its two variants (alkaline and neutral) to detect DNA/chromatin integrity has been evaluated in human, mouse, and bull sperm. The hypothesis that chromatin packaging might influence the amount of induced and detectable DNA damage was tested by treating sperm in vitro with DNAse I, whose activity is strictly dependent upon its DNA accessibility. Furthermore, hydrogen peroxide (H2O2) was used to assess whether spermatozoa of the three species showed a different sensitivity to oxidative stress. DNAse I-induced damage was also assessed by the sperm chromatin structure assay and the TUNEL assay, and the performances of these two assays were compared and correlated with the comet assay results. Results showed a different sensitivity to DNAse I treatment among the species with human sperm resulting the most susceptible. On the contrary, no major differences among species were observed after H2O2 treatment. Furthermore, the three tests show a good correlation in revealing sperm with DNA strand breaks.
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Fragmentación del ADN , Desoxirribonucleasa I/metabolismo , Peróxido de Hidrógeno/farmacología , Oxidantes/farmacología , Estrés Oxidativo/efectos de los fármacos , Espermatozoides/efectos de los fármacos , Animales , Bovinos , Ensamble y Desensamble de Cromatina/efectos de los fármacos , Ensayo Cometa , Relación Dosis-Respuesta a Droga , Humanos , Etiquetado Corte-Fin in Situ , Masculino , Ratones , Ratones Endogámicos C57BL , Espermatozoides/enzimología , Espermatozoides/patologíaRESUMEN
In recent years, several surveys have highlighted the presence of the rodent carcinogen furan in a variety of food items. Even though the evidence of carcinogenicity of furan is unequivocal, the underlying mechanism has not been fully elucidated. In particular, the role of genotoxicity in furan carcinogenicity is still not clear, even though this information is considered pivotal for the assessment of the risk posed by the presence of low doses of furan in food. In this work, the genotoxic potential of furan in vivo has been investigated in mice, under exposure conditions similar to those associated with cancer onset in the National Toxicology Program long-term bioassay. To this aim, male B6C3F1 mice were treated by gavage for 4 weeks with 2, 4, 8 and 15 mg furan/kg b.w./day. Spleen was selected as the target organ for genotoxicity assessment, in view of the capability of quiescent splenocytes to accumulate DNA damage induced by repeat dose exposure. The induction of primary DNA damage in splenocytes was evaluated by alkaline single-cell gel electrophoresis (comet assay) and by the immunofluorescence detection of foci of phosphorylated histone H2AX (gamma-H2AX). The presence of cross-links was probed in a modified comet assay, in which cells were irradiated in vitro with gamma-rays before electrophoresis. Chromosome damage was quantitated through the detection of micronuclei in mitogen-stimulated splenocytes using the cytokinesis-block method. Micronucleus induction was also assessed with a modified protocol, using the repair inhibitor 1-beta-arabinofuranosyl-cytosine to convert single-strand breaks in micronuclei. The results obtained show a significant (P < 0.01) increase of gamma-H2AX foci in mitogen-stimulated splenocytes of mice treated with 8 and 15 mg furan/kg b.w. and a statistically significant (P < 0.001) increases of micronuclei in binucleated splenocytes cultured in vitro. Conversely, no effect of in vivo exposure to furan was observed when freshly isolated quiescent splenocytes were analysed by immunofluorescence and in comet assays, both with standard and radiation-modified protocols. These results indicate that the in vivo exposure to furan gives rise to pre-mutagenic DNA damage in resting splenocytes, which remains undetectable until it is converted in frank lesions during the S-phase upon mitogen stimulation. The resulting DNA strand breaks are visualized by the increase in gamma-H2AX foci and may originate micronuclei at the subsequent mitosis.