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Biomedical subjects

A Botta

Publications and source records attributed to A Botta.

At least 55 records · Page 3Linked to original sources
PubMed1997

Effect of smoking on micronucleated epithelial cells in smears from the uterine cervix.

A pilot study was conducted to determine whether any relationship exists between micronucleated cell rates of female uterine cervical epithelium and current smoking status. Cervical uterine cells obtained from 118 pre-menopausal females, seen between September 1994 and June 1995 at the Occupational Medecine Interprofessional Association (AIMT), were tested for micronucleated cells by the micronucleus assay. Of the 68 subjects taken from this population that provided a least a 1000 analysed cells, 36 were non-smokers and 32 were smokers. Age distributions were different between smokers and non-smokers but results showed that age had no effect on micronucleated cell levels. Micronucleated cervical cell rates reached 0.66% in non-smokers and 1.11% in smokers: these two levels were not statistically different. No association was noted between number of cigarettes smoked and micronucleated cell levels. Results suggested that consuming 5-20 cigarettes per day was not enough to show a smoking effect on cervical micronucleated cells. A test with a greater number of female subjects would be necessary to confirm this.

Adolescent↗
PubMed1997

Comparison between micronucleated lymphocyte rates observed in healthy subjects and cancer patients.

Micronucleated cell rates were assessed in cytokinesis-blocked lymphocytes of 198 male and female healthy subjects (HS) not occupationally exposed to genotoxic risks and of 70 male and female cancer patients (CP) prior to any anticancer treatment. In the HS group, spontaneous micronucleated cell rates (MN cell rates) were 9.7 +/- 2.8 per 1000 binucleated lymphocytes and 9.8 +/- 3.1 for males and females respectively. In the CP group, spontaneous MN cell rates were 21.1 +/- 15.3 per 1000 binucleated lymphocytes and 19.1 +/- 11.2 for males and females respectively. Moreover, they were shown to have a large inter-individual variability in the two groups. The study of inter-individual variation factors showed that only tobacco could affect MN cell rate in HS whereas age and sex apparently had no significant effect. In the CP group, only age significantly affected MN cell rate, whereas sex, tobacco, alcohol, imaging techniques and tumour stage had no significant effect. There was no significant difference in the distribution of gender between HS and CP, whereas there was a significant difference in the distribution of age and tobacco between the two groups. The comparison of MN cell rates in 54 HS and 54 CP matched for age and sex showed a statistically significant difference. Spontaneous MN cell rates of these two populations reflect environmental exposure. Moreover, for CP it most probably refers to various cellular lesions and genetic damage.

Adolescent↗
PubMed1996

Micronuclei kinetics of exfoliated urothelial cells.

Micronuclei observed in exfoliated cells result from DNA-damage of basal epithelium's cells by mutagens. Exfoliated urothelial cells can be collected by non-invasive procedure and may be used as target site to identify genotoxic effects of chemicals. Kinetic studies are important for any biomarker, especially those in which tissue differentiation and maturation processes will heavily influence the time between induction of damage and collection of damaged cells for analysis. This manuscript details the result of a longitudinal study of micronuclei induction in cells isolated from urine samples of 4 healthy women over 6 consecutive days. Three of them were former smokers. Results suggested that micronucleated cell rates were not influenced neither by the day nor by the time of sampling.

Adult↗
PubMed1996

Analysis of sequence and pathogenic properties of two variants of encephalomyocarditis virus differing in a single amino acid in VP1.

The encephalomyocarditis (EMC) virus-induced diabetes-like syndrome in mouse inbred strains was used as a model to study the insulin-dependent diabetes mellitus (IDDM). Our investigations were performed with two EMC virus variants, PV2 and PV7. After infection of SJL mice with 10(5) PFU of PV2 about 70% of the animals developed a diabetes-like syndrome, whereas the PV7 infected mice appeared healthy. Histological examination and in situ experiments revealed that the islets of Langerhans are a main target of PV2, whereas PV7 infection leads to only modest changes of the islets. Sequence analysis of both variants revealed one amino acid exchange within the capsid protein VP1. Hence, we describe the first diabetogenic and non-diabetogenic EMCV variants differing in only one single amino acid.

Amino Acid Sequence↗
PubMed1996

[The Ames test: application to smokers' urine].

The Ames test is a rapid and sensitive in vitro technique for detecting mutagens by using Salmonella typhimurium hypersensibilized strains. We applied this assay to the study of smoker's urine mutagenicity. Eighteen smokers and 18 non-smokers were investigated. Statistical analysis showed a significant increase of the smoker's urine mutagenicity. The Ames test could be used to determine the mutagenicity level of smokers. Moreover, the results suggest the applicability of the Ames test to urines of ex-smokers and passive smokers.

Adult↗
PubMed1996

Optimization of the Salmonella/mammalian microsome assay for urine mutagenesis by experimental designs.

Assessing urine mutagenicity with the Salmonella mutagenicity test is often limited by the volumes of the samples. Optimization of the assay was performed with factorial and Doehlert designs. Two fractional factorial designs 2(3-1) (3 factors, 4 experiments) were used to estimate the main effects of the percent S9 in the mix, the time of liquid incubation, the inoculum size and the growth conditions. A Doehlert design (3 factors, 13 experiments) was used to study the main effects and the interactions of the NADP, G6P and S9 in the mix. The positive markers were benzo[a]pyrene (BaP, 0.3 microgram/plate) and a pool of smokers' urine (SU, 1.25 ml equivalent/plate). The response was limited to the induction factor (IF, number of induced revertants/number of spontaneous revertants) with Salmonella typhimurium TA98. The optimal conditions for BaP were: a 60 min period of liquid incubation and a volume of 0.1 ml (approx. 10(8) cells/plate) of an overnight culture grown in 50 ml of Nutrient Broth No. 2 from a 250 ml flask. The S9 mix (0.1 ml, final volume) included 1.5% of S9, 1.0 mM NADP and 4.4 mM G6P. The maximal IF was 15.79. The optimal conditions for SU were: a 60 min period of liquid incubation and a volume of 0.1 ml (approx. 10(8) cells/plate) of an overnight culture grown in 7 ml of Nutrient Broth No. 2 from a 20 x 180 mm tube. The S9 mix (0.1 ml, final volume) included: 4% S9, 4.2 mM NADP and 5.2 mM G6P. The maximal IF was 10.95. These optimal conditions did not modify the spontaneous frequencies of the tester strains: TA97a, TA98, TA100 and TA102. The dose-response curves of mutagenic urine samples were found to be non-linear. This micromethod required 8-fold less urine sample and 12.5-fold less liver homogenate as compared to the standard plate incorporation assay and was from 6.2- to 11.8-fold more sensitive to evaluate urine mutagenicity. The sensitivity of this technique was found to be limited to individuals smoking more than approx. 5 cigarettes/day by the standard extraction-concentration procedure.

Dose-Response Relationship, Drug↗
PubMed1996

Protective effects of alpha-hederin, chlorophyllin and ascorbic acid towards the induction of micronuclei by doxorubicin in cultured human lymphocytes.

The influence of alpha-hederin (a saponin isolated from Hedera helix), chlorophyllin, the sodium-copper salt of chlorophyll, and ascorbic acid (vitamin C) on the direct clastogenicity of doxorubicin (Adriamycin) was investigated in vitro in human lymphocytes for the induction of micronuclei. In order to determine a possible mechanism of action responsible for the antimutagenic activity, treatments were performed for the three substances at different times of the culture (pre-treatment, simultaneous and post-treatment). Alpha-hederin (1.3 x 10(-2), 0.13, 1.3 and 13 nmol/ml) and chlorophyllin (0.14, 1.4 and 14 nmol/ml) were found to exert an antimutagenic effect against the clastogenicity of doxorubicin (1.5 x 10(-2) nmol/ml) in all treatments at all concentrations. Ascorbic acid (10 nmol/ml) was effective in reducing the micronucleus levels only in the simultaneous treatment, when it was previously incubated with doxorubicin for 2 h at 37 degrees C before being introduced into the culture. Our results suggested a desmutagenic effect for alpha-hederin, chlorophyllin and ascorbic acid. Chlorophyllin acted also through a bio-antimutagenic mechanism and alpha-hederin seemed to induce metabolic enzymes, which inactivated doxorubicin. Preliminary studies showed that the effective antimutagenic concentrations of alpha-hederin, chlorophyllin and ascorbic acid had no clastogenic or aneugenic effects in human lymphocytes. No cytotoxicity was observed for the three antimutagenic agents either.

Adult↗
PubMed1996

[Urinary screening of drugs of abuse among drivers involved in road accidents].

Driving under the influence of drugs is a growing cause of traffic injuries. Therefore the Abbott Laboratories established a study to estimate the consumption of opiates, cannabinoids, cocaine and amphetamines among young adults involved in a road accident and to compare with a control group. Analytical procedure chosen include an anonymous collection of urines. Drugs are screened by fluorescence polarization immunoassay. Positive samples are confirmed by gas chromatography/mass spectrometry. Results do not show any difference between the two groups.

Accidents, Traffic↗
PubMed1995

Monitoring exposure of hospital personnel handling cytostatic drugs and contaminated materials.

A study was undertaken to evaluate the urine mutagenicity of 63 individuals working in four hospital departments. The exposed group included 38 subjects who were exposed to various cytostatic drugs and/or contaminated material from treated patients. The control group included 25 individuals of the hospital personnel. Urine mutagenicity was monitored by the Ames test using tester strains TA 98 + S9 Mix and TA 102-S9 Mix. Urine samples were collected before and after the working periods. A total of 29/116 (25%) urine samples were mutagenic for either strain. Among the mutagenic samples, 24/29 were mutagenic for tester strain TA 98 exclusively. No significant correlation could be found between occupational exposure to cytostatic drugs and urine mutagenicity evaluated by the strain TA 98 + S9 Mix. Smoking was the main environmental factor that modulated urine mutagenicity with TA 98. Three subjects in the exposed group had mutagenic urine samples at the end of the working period with strain TA 102-S9 Mix. This mutagenicity was related to occupational exposure to cisplatin. In the control group, one individual had mutagenic samples before and after the working period. Assessing occupational exposure to cytostatic drugs with strain TA 102 requires additional studies to determine environmental mutagens which can be detected by this strain.

Adult↗
PubMed1995

The micronucleus assay in human exfoliated urothelial cells: effect of smoking.

Micronucleated cell rates were examined in exfoliated urothelial cells of 73 healthy donors not occupationally exposed to mutagens or aneugens. Micronucleated cell levels averaged 0.54 +/- 0.68% in the entire population: they reached 1.09% in smokers, 0.95% in ex-smokers and 0.24% in non-smokers. Among variation factors evaluated during this study, only smoking had a significant effect on micronucleated cell rates (P = 0.007) whereas age and sex had no effect (P = 0.101 and P = 0.918). No significant difference was observed between micronucleated cell rates of smokers and ex-smokers, suggesting that smoking could generate clones of basal micronucleated cells in urothelial tissues.

Adolescent↗
PubMed1995

[Tests of micronucleus count in lymphocytes: a validation study].

In spite of the development of new automated methods proposed for scoring of micronuclei, manual analysis of micronucleated cells by light microscopy is still largely employed. The purpose of this study was to define the minimal number of mononucleated and binucleated cells representative of the total number of cells of the side, to determine the division rate. The second aim was to define the minimal number of binucleated cells representative of the total number of the binucleated cells on the same slide, to determine the rate of binucleated micronucleated cells. Total mononucleated, binucleated and polynucleated cells were scored in each slide for determining the 'theoretical division rate'. Among total binucleated lymphocytes observed in each slide, micronucleated cells containing one, two or more micronuclei were scored to determine the 'theoretical micronuclei rate'. Then, 'experimental division rates' were calculated by dividing microscope slides into random areas of 500 lymphocytes, and recording mononucleated, binucleated cells. 'Experimental micronuclei rates' were determined by dividing microscope slides into random areas of 500 binucleated cells, and recording micronucleated cells containing one or more micronuclei. 'Experimental division rates' obtained by examining sets of 4000 cells were shown to be not representative of the corresponding 'theoretical rate' (statistical difference by the chi-squared test, p < 0.05)). 'Experimental micronuclei rates' obtained by examining sets of 500 binucleated cells were shown to be representative of the corresponding 'theoretical micronuclei rate' (no statistical difference by the chi-squared test, p > 0.05).

Adult↗
PubMed1994

The micronucleus assay in human lymphocytes: screening for inter-individual variability and application to biomonitoring.

Micronuclei levels were assessed in cytokinesis-blocked lymphocytes of 200 male and female healthy donors not occupationally exposed to genotoxic risks and of 33 male industrial painters handling genotoxic substances. Frequency of micronucleated cells was 9.87 +/- 3.1 per 1000 in the control population and was shown to have a large inter-individual variability. The study of factors contributing to this variability showed that only smoking could affect micronucleated cell rate, inducing an increase of 25%, whereas age and sex had no effect. Among the industrial painters, frequency of micronucleated cells averaged 18.30 +/- 7.39 per 1000: the difference between the two populations studied was shown to be statistically significant by the Mann-Whitney rank sum test (one-sided U test) and indicated that exposed painters need preventive measures.

Adult↗
PubMed1992

[Assay of micronuclei in binucleated T-lymphocytes. Analysis of the distribution and variation factors in a population of 100 subjects].

The authors analysed micronuclei levels distribution in lymphocytes of 100 non occupationally exposed subjects and studied the effect of age, sex and smoking of donors on the distribution. Results showed that micronucleated cells were distributed according to a normal distribution (average = 9.5 +/- 4 micronucleated cells in 1,000 binucleated lymphocytes). Age and sex of donors had no effect on the distribution but, concerning smoking, the results showed that micronuclei levels were correlated to the number of cigarettes daily smoked.

Adult↗