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Biomedical subjects

E Cordelli

Publications and source records attributed to E Cordelli.

At least 19 recordsLinked to original sources
PubMed2006

935 MHz cellular phone radiation. An in vitro study of genotoxicity in human lymphocytes.

PURPOSE: The possibility of genotoxicity of radiofrequency radiation (RFR) applied alone or in combination with x-rays was investigated in vitro using several assays on human lymphocytes. The chosen specific absorption rate (SAR) values are near the upper limit of actual energy absorption in localized tissue when persons use some cellular telephones. The purpose of the combined exposures was to examine whether RFR might act epigenetically by reducing the fidelity of repair of DNA damage caused by a well-characterized and established mutagen. METHODS: Blood specimens from 14 donors were exposed continuously for 24 h to a Global System for Mobile Communications (GSM) basic 935 MHz signal. The signal was applied at two SAR; 1 and 2 W/Kg, alone or combined with a 1-min exposure to 1.0 Gy of 250 kVp x-rays given immediately before or after the RFR. The assays employed were the alkaline comet technique to detect DNA strand breakage, metaphase analyses to detect unstable chromosomal aberrations and sister chromatid exchanges, micronuclei in cytokinesis-blocked binucleate lymphocytes and the nuclear division index to detect alterations in the speed of in vitro cell cycling. RESULTS: By comparison with appropriate sham-exposed and control samples, no effect of RFR alone could be found for any of the assay endpoints. In addition RFR did not modify any measured effects of the x-radiation. CONCLUSIONS: This study has used several standard in vitro tests for chromosomal and DNA damage in Go human lymphocytes exposed in vitro to a combination of x-rays and RFR. It has comprehensively examined whether a 24-h continuous exposure to a 935 MHz GSM basic signal delivering SAR of 1 or 2 W/Kg is genotoxic per se or whether, it can influence the genotoxicity of the well-established clastogenic agent; x-radiation. Within the experimental parameters of the study in all instances no effect from the RFR signal was observed.

Adult↗
PubMed2004

Evaluation of genotoxic effect of low level 50 Hz magnetic fields on human blood cells using different cytogenetic assays.

The question whether extremely low frequency magnetic fields (ELFMFs) may contribute to mutagenesis or carcinogenesis is of current interest. In order to evaluate the possible genotoxic effects of ELFMFs, human blood cells from four donors were exposed in vitro for 48 h to 50 Hz, 1 mT uniform magnetic field generated by a Helmholtz coil system. Comet assay (SCGE), sister chromatid exchanges (SCE), chromosome aberrations (CAs), and micronucleus (MN) test were used to assess the DNA damage. ELF pretreated cells were also irradiated with 1 Gy of X-ray to investigate the possible combined effect of ELFMFs and ionizing radiation. Furthermore, nuclear division index (NDI) and proliferation index (PRI) were evaluated. Results do not evidence any DNA damage induced by ELFMF exposure or any effect on cell proliferation. Data obtained from the combined exposure to ELFMFs and ionizing radiation do not suggest any synergistic or antagonistic effect.

Adult↗
PubMed2003

Evaluation of DNA damage in different stages of mouse spermatogenesis after testicular X irradiation.

To evaluate whether DNA alterations in mature spermatozoa could stem from DNA damage induced in immature germ cells, testis cells and spermatozoa were analyzed by the comet assay and by the sperm chromatin structure assay 14, 45 and 100 days after in vivo X irradiation of the testes. These times were selected, according to the mouse seminiferous epithelium cycle, to follow the DNA damage induced in different germ cell compartments. The cytotoxic action was assessed by DNA flow cytometric analysis of testicular cells. A dose-dependent increase of DNA damage in testis cells was observed 14 days after irradiation, whereas mature sperm cells were not affected. On the other hand, an increase in DNA strand breaks was seen in spermatozoa 45 days after treatment. DNA damage returned to the control levels 100 days after irradiation. The methods used to evaluate DNA damage gave comparable results, emphasizing the correlation between DNA fragmentation and susceptibility of sperm chromatin to denaturation. Both techniques showed the high radiosensitivity of differentiating spermatogonia. The overall results showed that DNA damage induced in pre-meiotic germ cells is detectable in primary spermatocytes and is still present in mature spermatozoa.

Animals↗
PubMed2000

Analysis of DNA oxidative damage related to cell proliferation.

In vivo and in vitro cell populations exhibit a different sensitivity and a heterogeneous response to many genotoxic agents. Several studies have been carried out to evaluate the possibility that the different sensitivity of the cells is related to their proliferative status. In this study, the sensitivity of proliferating (P) and quiescent (Q) C3H10T1/2 cells to oxidative damage and their repair capability has been investigated by single cell gel electrophoresis (SCGE) and micronucleus test. Furthermore the possibility to simultaneously detect DNA damage and cell cycle position has been evaluated. Our results showed a dose-related increase of DNA damage in exponential and plateau phase cells treated with hydrogen peroxide (doses ranging between 2.5 and 100 microM). DNA damage was almost completely repaired within 2 h after treatment in both culture conditions. The percentage of cells in the various phases of the cell cycle has been determined by comet assay and by flow cytometry, and a good agreement between the results of the two techniques was found. Untreated exponentially growing cells in G1 phase showed a lower tail moment than S and G2/M cells. The same cell cycle dependence was evidenced in cells treated with low doses of H(2)O(2), while, at the higher doses, all cells showed a similar level of damage. These results confirm the sensitivity of the Comet Assay in assessing DNA damage, and support its usefulness in evaluating cell cycle-related differential sensitivity to genotoxic agents.

Animals↗
PubMed2000

Sperm chromatin damage impairs human fertility. The Danish First Pregnancy Planner Study Team.

OBJECTIVE: To examine the relationship between sperm chromatin defects, evaluated by the flow cytometric (FCM) sperm chromatin structure assay (SCSA), and the probability of a pregnancy in a menstrual cycle (fecundability). DESIGN: Follow-up study. SETTING: The Section of Toxicology and Biomedical Sciences, ENEA Casaccia, Rome, Italy, and the Department of Occupational Medicine, Aarhus University Hospital, Aarhus, Denmark. PATIENT(S): Two hundred fifteen Danish first pregnancy planners with no previous knowledge of their fertility capability. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Semen samples were collected at enrollment to measure semen volume, sperm concentration, motility, and morphology (by microscopy), as well as chromatin susceptibility to in situ, acid-induced partial denaturation by the FCM SCSA. Time to pregnancy was evaluated during a 2-year follow-up period. Demographic, medical, reproductive, occupational, and lifestyle data were collected by questionnaire. Fecundability was correlated with SCSA-derived parameters. RESULT(S): Fecundability declines as a function of the percentage of sperm with abnormal chromatin and becomes small when aberrant cells are >40%. CONCLUSION(S): Optimal sperm chromatin packaging seems necessary for full expression of the male fertility potential. The SCSA emerged as a predictor of the probability to conceive in this population-based study.

Chromatin↗
PubMed1999

Nuclear chromatin variations in human spermatozoa undergoing swim-up and cryopreservation evaluated by the flow cytometric sperm chromatin structure assay.

The sperm chromatin structure assay (SCSA) is a flow cytometric (FCM) technique which exploits the metachromatic properties of Acridine Orange to monitor the susceptibility of sperm chromatin DNA to in-situ acid denaturation. SCSA was used to study the chromatin structure variations of human spermatozoa in semen, both before and after swim-up and after cryopreservation. Semen samples were provided by 19 healthy normozoospermic subjects attending pre-marriage checks. Each sample was divided into three aliquots: the first aliquot was evaluated without further treatment, the second underwent swim-up, and the third was stored according to standard cryopreservation techniques in liquid nitrogen at -196 degrees C. Samples were also analysed by light and fluorescence microscopy (after Acridine Orange staining to evaluate the number of green fluorescent sperm heads), and by computer-assisted semen analysis. The results showed that post-rise spermatozoa represent a subpopulation characterized by a general improvement of the morphological (reduction of the percentage of abnormal forms and heads, increase of the green head sperm percentage) and kinetic parameters. This subpopulation also exhibited improved chromatin structure properties, confirming that these cells have the best structural and functional characteristics, indicative of optimal fertilizing ability. On the other hand, overall sperm quality deteriorates after cryopreservation. When thawed spermatozoa underwent an additional swim-up round, a general improvement of nuclear maturity was seen in the post-rise spermatozoa.

Adult↗
PubMed1998

Enhancement of radiation response by paclitaxel in mice according to different treatment schedules.

PURPOSE: The aim of our study was to determine if paclitaxel could be used as a radiosensitizer in vivo. MATERIALS AND METHODS: Paclitaxel was tested as a single agent and combined with an X-ray treatment. Paclitaxel was administered i.p. in doses from 30 to 120 mg/kg b.w. to (C3D2F1) mice bearing spontaneous mammary carcinoma. Tumor growth delay (TGD) or tumor control dose (TCD50, radiation dose needed to induce local tumor control in 50% of irradiated animals) and moist desquamation dose (MDD50, radiation dose needed to induce serious moist desquamation in 50% of the non-tumor-bearing feet) were the endpoints. DNA flow cytometric analysis was performed. RESULTS: DNA analysis demonstrated a G2/M block of tumor cells and a depletion of cells in S phase, with a maximum at 24 h from paclitaxel administration. Administering paclitaxel, in graded doses, 15 min before a 10-Gy X-ray treatment resulted in a linear regression line, almost parallel to that with paclitaxel alone, with a growth delay of about 6 days. In contrast, varying the X-ray dose with a constant paclitaxel injection (45 mg/kg b.w.) treatment showed some degree of synergism as the linear regression curves diverged. Interval time and sequence between paclitaxel administration and a 10 Gy X-ray treatment did not influence TGD. Protocols with paclitaxel at 30, 45, or 60 mg/kg were combined with radiation treatments at various doses (from 10 to 65 Gy). Values of TCD50 varied from 50.8 Gy for X-ray alone to 31.8 Gy for paclitaxel 60 mg/kg + X-ray. No differences were observed among MDD of different protocols. CONCLUSIONS: These results suggest that, under some conditions, paclitaxel combined with radiation can show superadditive effects and this result combined with the lack of severe normal tissue damage indicate that a favorable therapeutic gain can be obtained.

Animals↗
PubMed1998

Diepoxybutane cytotoxicity on mouse germ cells is enhanced by in vivo glutathione depletion: a flow cytometric approach.

Diepoxybutane is one of the key metabolites of butadiene, a compound of high environmental and occupational concern. The effects of diepoxybutane on mouse reproductive cells have been previously characterized by flow cytometry demonstrating a specific, dose-dependent cytotoxicity for differentiating spermatogonia. It is known that butadiene epoxides, deriving from butadiene bioactivation by cytochrome P450-monooxygenase systems, can be enzymatically conjugated to glutathione by glutathione S-transferases. In this paper, we tested the hypothesis whether a pretreatment with phorone, a well-known intracellular glutathione depleter, would enhance the germ cell cytotoxicity of diepoxybutane. Results were consistent with an active role played in vivo by the glutathione-detoxifying system, as diepoxybutane cytotoxicity was increased after chemically induced reduction of glutathione concentration.

Animals↗
PubMed1998

Reproductive toxicity of 1,3-butadiene in the mouse: cytogenetic analysis of chromosome aberrations in first-cleavage embryos and flow cytometric evaluation of spermatogonial cell killing.

Reproductive effects of 1,3 butadiene inhalation have been evaluated in male mice by reduction of post-meiotic germ cells, alteration of sperm chromatin structure and transmission of chromosome aberrations to one-cell embryos. Animals were exposed for 5 consecutive days for 6 h per day to butadiene concentrations of 130, 500 or 1300 ppm. The testicular fraction of post-meiotic germ cells was measured by flow cytometric analysis on the basis of their DNA content. Round spermatids were discriminated from mature, elongated spermatids by their different degree of chromatin condensation. Butadiene-induced cytotoxic effects on differentiating spermatogonia were shown by a concentration-dependent decrease of round spermatids occurring 21 days after chemical exposure, confirmed by a similar decrease of elongated spermatids measured in testes sampled 7 days later. Statistically significant effects were seen already at 130 ppm. An incomplete repopulation of the elongated spermatid compartment observed 35 days after exposure to 1300 ppm suggested that, at the highest concentration tested, butadiene toxicity extended to stem cells. Alterations of sperm chromatin were revealed by its increased sensitivity to acidic denaturation in situ. The percentage of abnormal sperm was significantly increased after butadiene exposure of differentiating spermatogonia and spermatocytes. This suggested the induction of persistent effects interfering with chromatin remodelling during spermiogenesis. Chromosome-type structural aberrations were significantly elevated in first-cleavage embryos conceived by males mated during the first and second week after the end of exposure. The lowest effective tested concentration was 500 ppm, the same reported for dominant lethal induction under identical exposure conditions. As in the dominant lethal assay, the effect of this dose was confined to exposed sperm, while both sperm and late spermatids were affected by the inhalation of 1300 ppm. A quantitative comparison between the effects induced by intraperitoneal injections of diepoxybutane or butadiene inhalations suggested that other reactive intermediates, in addition to diepoxybutane, might contribute to mediate butadiene-induced reproductive toxicity.

Animals↗
PubMed1998

Greater antitumor efficacy of paclitaxel administered before epirubicin in a mouse mammary carcinoma.

Combined treatment with paclitaxel and anthracyclines is increasingly being tested in clinical practice. Epirubicin is in general administered before paclitaxel. We have investigated, using a murine mammary adenocarcinoma, whether the efficacy and toxicity of this combination is influenced by treatment sequence, different time intervals and dose intensity. The tumor was transplanted into the right hind foot of C3D2F1 female mice. Paclitaxel was administered i.p. in doses ranging from 15 mg/kg to 75 mg/kg and epirubicin (i.p. or i.v.) in doses from 9 mg/kg to 30 mg/kg. The hepatic and peritoneal toxicity observed with epirubicin administration increased in combined treatments (stronger with i.p. than i.v. epirubicin administrations) and was dose-dependent. When paclitaxel and epirubicin were administered simultaneously or paclitaxel was given 24 h before epirubicin, the same tumor growth delays were obtained in all groups. A smaller effect was observed when paclitaxel was administered 24 h after epirubicin. Increasing the epirubicin or paclitaxel dose led to higher tumor growth delays but also an increased toxicity. In conclusion, in this experimental model, the administration of 45 mg/kg paclitaxel before 15 mg/kg epirubicin was very effective and the increased toxicity can be limited by introducing an interval of 24 h between drug administrations. These results should be considered when designing clinical trials.

Animals↗
PubMed1998

The applicability of the flow cytometric sperm chromatin structure assay in epidemiological studies. Asclepios.

The impact of demographic, lifestyle, and seminal factors on the sperm chromatin structure assay (SCSA) parameters was evaluated in a population of 277 healthy Danish men. This cohort was established within the framework of a European Concerted Action on occupational hazards to male reproductive capability in order to examine the possible reproductive effects of exposure to styrene or pesticides. The SCSA measures the susceptibility of sperm DNA to in-situ acid-induced denaturation, by multiparameter flow cytometric analysis after staining with the DNA-specific fluorescent dye acridine orange. The green versus red bivariate cytogram patterns were quite variable among donors, showing a wide heterogeneity of sperm DNA denaturability. Nevertheless, in those cases where we had the possibility to measure two semen samples from the same donor, the cytogram pattern remained stable over time (0.64 < r < 0.78). Analysis of variance demonstrated that the SCSA results can be influenced by the age of the donor (P < 0.0001), smoking habits (P < 0.05), the presence of leukocytes and immature germ forms in the ejaculate (P < 0.0001), and the duration of sexual abstinence (P < 0.0001). Furthermore, the relationship between the SCSA data and sperm concentration, morphology, and vitality was weak (-0.22 < r < -0.46). Therefore, the SCSA provides independent and complementary measurements of semen quality and is thus a useful tool for epidemiological studies, but the effects of some confounders should be accounted for in the survey design and analysis.

Adolescent↗
PubMed1997

DNA integrity in human sperm.

Since the 1970s there have been conflicting reports of decreasing sperm counts in man and increasing testicular cancer. There is a hypothetical link between apparent adverse trends in several measures of human reproductive health and exposure to endocrine disrupters. Rodent bioassays are not suited for the large-scale screening of such chemicals because of their costs, complexity, and ethical concerns. Various in vitro assays have been used to examine the effects of these chemicals, but none has directly used semen as one of the target tissues in man. The present study has examined in the alkaline Comet assay in human sperm the effect of two estrogens--beta-estradiol and the phytoestrogen daidzein--and 1,2-epoxybutene, a metabolite of 1,3-butadiene, and compared them with the effects of the known reprotoxin, dibromochloropropane, in two fertile and two infertile frozen sperm samples and two fresh fertile samples. While differences were detected in the frozen fertile and infertile samples with flow cytometry, in the Comet assay both frozen and fresh samples exposed to the chemicals in vitro from fertile and infertile men produced similar altered responses by comparison with untreated samples. The integrity of DNA is necessary not only for the noncancerous state, but also for the accurate transmission of genetic material to the next generation. Thus this assay may be useful for examination of chemicals in fresh and frozen sperm samples.

DNA↗
PubMed1996

Flow cytometric assessment of trophosphamide toxicity on mouse spermatogenesis.

The effects of trophosphamide on mouse reproductive cells have been investigated by flow cytometric analysis of testicular cell populations and alterations of sperm chromatin structure. Mice were treated with single intraperitoneal injections of TP, the doses ranging between 50 and 150 mg/kg, and were killed after 7, 14, 21, 28, 35, or 49 days. Dose-dependent reductions of tetraploid cells, round spermatids, and elongated spermatids were detected at 7, 21, and 28 days, respectively, reflecting cytotoxic damage to the differentiating spermatogonia compartment. The dose necessary to reduce the number of differentiating spermatogonia to half the control value was approximately 70 mg/kg. Stem cells were not affected by this treatment, and the normal spermatogenic process was restored after 7 weeks. In addition, cauda epididymal sperm were analyzed by the sperm chromatin structure assay, a flow cytometric measurement of the susceptibility of the sperm nuclear DNA to in situ acid denaturation; a statistically significant increase of sperm with altered chromatin structure was detected after a TP treatment of 150 mg/kg. Together with previous findings published in the literature, where the same doses induced heritable genetic damage, this study demonstrates a marked adverse cytotoxic effect of TP on the male reproductive integrity. All this information should be taken into consideration when TP is used in chemotherapeutic regimens.

Animals↗
PubMed1996

Flow cytometric and histological assessment of 1,2:3,4-diepoxybutane toxicity on mouse spermatogenesis.

The effects of diepoxybutane (DEB) on mouse reproductive cells have been investigated by flow cytometric and histological description of testicular cell populations and alterations of sperm chromatin packaging. Mice were treated with single intraperitoneal injections of DEB, with doses ranging between 8.5 and 78 mg/kg (100-900 microM), and were killed after 7, 14, 21, 28 or 35 d. Dose-dependent reductions of tetraploid cells, round spermatids, and elongated spermatids were detected at 7, 21, and 28 d, respectively, reflecting cytotoxic damage on the differentiating spermatogonia compartment. The dose necessary to reduce the number of differentiating spermatogonia to half the control value was estimated equal to 650 microM or 55 mg/kg. Stem cells were not affected by this treatment. Histological section of seminiferous tubules showed depletion of spermatids and reduction of the secondary spermatocyte layers. In addition, a high although not statistically significant frequency of sperm with altered chromatin packaging was detected after DEB treatment. DEB is one of the key metabolites of butadiene, which is a compound of high environmental and occupational concern. These results contribute to the assessment of the reproductive health impact of butadiene in humans.

Animals↗
PubMed1995

Mouse testis cell sorting according to DNA and mitochondrial changes during spermatogenesis.

Flow cytometry can measure variations in DNA content and chromatin structure as well as dramatic changes in the mitochondria of germ cells during maturation from spermatogonia to elongated spermatids. Using 10-N nonyl acridine orange (NAO), an inner mitochondrial membrane dye, it is easy to follow mitochondria rearrangements. Mouse testis cells stained with the DNA fluorescent probe propidium iodide (PI) and analyzed by flow cytometry can be discriminated on the basis of their ploidy levels into five main regions corresponding to elongated spermatids, round spermatids, diploid, S-phase, and tetraploid cells. The simultaneous use of PI and NAO demonstrated the presence of cells having low and high mitochondrial content in the haploid, diploid, and tetraploid compartments. Eleven sorting windows were selected from the bivariate analysis (PI/NAO) and the corresponding cells were identified by microscopic observation. Cells were also discriminated by two parameter analysis of DNA content vs. cell diameter. The definition of seven different regions allowed us to determine NAO or rhodamine 123 (Rh 123) uptakes in each compartment. We observed that the ratio (Rh 123/NAO) dramatically changed according to the progression of cell differentiation which occurs during spermatogenesis.

Acridine Orange↗