Evaluation of genotoxic effects of lead in pottery-glaze workers using micronucleus assay, alkaline comet assay and DNA diffusion assay.

PURPOSE: We investigated genotoxic effects of occupational exposure to lead acetate in pottery-glaze ceramic workers. METHODS: The study was carried out in 30 exposed workers and 30 matched controls, to whom several biochemical parameters-the blood lead (B-Pb; range: exposed, 41.68-404.77; controls, 12-52) and cadmium (B-Cd) level, the activity of delta-aminolevulinic acid dehydratase (ALAD), erythrocyte protoporphyrin (EP), the level of vitamin B(12) and folate in serum-were measured. The genotoxic effects were evaluated by the alkaline comet assay, the DNA diffusion assay and micronucleus test in peripheral blood lymphocytes. RESULTS: Subjects exposed to lead had significantly higher B-Pb level and, consequently, increased values of tail intensity (TI), frequency of apoptotic and necrotic cells, and frequency of micronuclei (MN). In contrast, their activity of ALAD, the level of vitamin B(12) and folate in serum were significantly lower compared to controls. Poisson regression analysis showed a significant correlation of profession, duration of exposure, smoking, level of cadmium in blood, ALAD and EP with primary DNA damage. A majority of primary damage repairs in a short period after exposure to a genotoxic agent. In addition, the influence of gender and level of vitamin B(12) and folate in serum MN frequency in exposed group was observed. CONCLUSIONS: In this study, DNA diffusion and micronucleus test showed higher influence of tested parameters to DNA damage. The results indicate a need for concomitant use of at least two different biomarkers of exposure when estimating a genetic risk of lead exposure.

Estimation of genome damage after exposure to ionizing radiation and ultrasound used in industry.

The application of ionizing radiation in industry for nondestructive testing entails a specific framework of working conditions that include field work, facilities with different radioactive sources, maintenance thereof without halting production, use of nonionizing radiation, and exposure to chemical agents. The present study gives an estimation of recent genome damage in two groups of subjects using chromosome aberration assay and micronucleus assay. The first group was exposed to (192)Ir and the second was simultaneously exposed to (192)Ir and ultrasound. The results show that both groups had higher values of chromosome aberrations and micronucleus frequency than controls. The group of examinees exposed both to (192)Ir and ultrasound had significantly more chromatid breaks, acentric fragments, and dicentric chromosomes, and had a significantly higher frequency of micronuclei than subjects exposed to (192)Ir only. The study suggests that the detected differences in the genome damage may be attributed to the action of ultrasound. This study confirms the dosimetry data for ionizing radiation, which indicate that the methods used in industrial radiography and the usage of nonionizing radiation entail an increased health risk. In the absence of personal dosimeters for nonionizing radiation and chemical agents, biomonitoring provides reliable parameters for estimation of genome damage and may lead to improvements in working conditions and radiation safety programs.

Cytogenetic consequences after occupational exposure to antineoplastic drugs.

Cytogenetic monitoring was carried out on a group of 38 nurses who reconstitute antineoplastic drugs in order to determine the extent of chromosomal damage. Genotoxic activities of antineoplastic drugs are studied by chromosome aberration assay, micronucleus assay, sister chromatid exchange (SCE) frequency high frequency cells (HFC) analysis, and mitotic activity of peripheral lymphocytes. Results confirmed that occupational exposure to a mixture of antineoplastic drugs may cause genome damages. The results of this study show that biomonitoring after exposure to a mixture of antineoplastic drugs which express clastogenic and aneugenic activity should involve a battery of cytogenetic methods.

Transtelephonic transmission of electrocardiograms in Slovenia.

The transtelephonic transmission of electrocardiograms (ECGs) was introduced in Slovenia in 1996 and has been used regularly since September 1997 by health institutions and patients with cardiovascular diseases. Portable 12-channel ECG equipment weighing less than 200 g is generally used. The diagnostic centre is located in the intensive-care unit at the University Medical Centre Ljubljana. In the first 12 months of regular operation we received 463 calls, 213 of which were diagnostic. The most common reasons for calling were: ischaemic chest pain, atypical chest pain, palpitations and dyspnoea. The most common diagnoses made on the basis of history and the ECG were: acute myocardial infarction, angina pectoris, paroxysmal tachycardias and atypical chest pain. In 40% of cases the cardiologist's advice sufficed; 38% of patients were referred to the emergency room, 29% immediately and 9% only if a suggested therapy did not prove successful; and in 21% of cases new medication or a change of dosage of current medication was suggested. Transtelephonic ECG transmission enables direct communication between general practitioner or patient and cardiologist. With its use, time from onset of symptoms to initiation of treatment is shortened, which reduces disability and mortality due to cardiovascular diseases and improves cost-benefit.

Transtelephonic ECG in Slovenia.

Transtelephonic ECG has been introduced in Slovenia in 1996. It has been operating on a regular basis since September 1997. Users of the system are health institutions and patients with CV diseases. They use portable 12-channel ECG weighing less then 200 grams. Diagnostic center is located in medical ICU in Clinical Center Ljubljana. In the first 20 months of regular operation we have received 852 calls, 450 of them being diagnostic. The most common reasons for calling were: ischaemic chest pain, atypical chest pain, palpitations and dyspnoea. Most common diagnoses made on the basis of history and ECG were: AMI, angina pectoris, paroxysmal tachycardias and atypical chest pain. In 186 cases the cardiologist's advice sufficed, 171 patients were referred to the ER, 142 immediately and 29 only if suggested therapy hadn't been successful. To 82 patients new medication or changed dosage of previous medication was suggested. With the intent to evaluate accuracy of the diagnoses made on the basis of history and transtelephonic ECG evaluation we followed up the patients who were sent to ER in Ljubljana upon our cardiologists' advice. On the basis of preliminary results we can conclude that TTE is as diagnostic as the conventional ECG and its' use shortens time from onset of symptoms to initiation of treatment, it lowers disability and mortality due to CV diseases and improves cost benefit.

The telemedicine and second medical opinion.

Telemedicine is declared as delivery of care to patients anywhere in the world by combining communications technology, with medical expertise. The well established applications of telemedicine are in the field of teleradiology, pathology, cardiology. In some cases video-conferencing (VC) may be applied. Second medical opinion is an important additional viewpoint on the patient diagnosis and treatment. The established network of consultant hospitals and worldwide Second opinion centers enable a fast (24-72 hours response) second medical opinion consultation service with the telemedicine application. The consultant hospitals at present time are: UCSF--San Franscisco, Stanford Medical Center, Bowman Gray School of Medicine, The Brigham Radiology Foundation, Emory University Hospital, University of Pennsylvania Medical Center. The second opinion centers are located worldwide, just to mention some of them: London, Budapest, Ljubljana, Tel Aviv, Bombay, Athens, Milano, Seoul.

Short-term effects of ambient nitrogen oxides on the number of emergency asthma cases in Zagreb, Croatia.

The paper describes an investigation of short-term effects of NO2 concentrations in the air on the number of emergency room visits caused by respiratory impairments, particularly asthma in adults and children. The data were collected from clinical emergency room records from July 1, 1994 to December 31, 1995. Concurrently, readings of average weekly concentrations of NO2 (microgram/m3), average weekly temperature (degree C), air pressure (kPa), and relative humidity (%) were registered. Trend and seasonality effects were estimated by the locally weighted regression (LOESS). After standardising for trend, seasonality, and meteorological conditions, the number of cases was regressed on weekly NO2 concentration, including the current and the previous week concentrations and autocorrelated residual. The weekly average NO2 concentrations were significantly associated with the number of emergency asthma cases for children and adults and with the total number of emergency respiratory cases in children, but not in adults. The results suggest that health effects of NO2 on risk groups can be detected even in moderately polluted environments. The effect is more pronounced in children.

Hydrochemical characterization of arsenic contaminated alluvial aquifers in Eastern Croatia using multivariate statistical techniques and arsenic risk assessment.

Multivariate statistical analyses, cluster, factor and discriminant analyses, were used to estimate spatial variations in groundwater chemistry in Eastern Croatia and to identify the main geochemical processes responsible for high arsenic (As) concentrations in the groundwater analyzed. Cluster analysis revealed five different groups of sampling sites linked with groundwater evolution, hydrochemical characteristics and different As content in the groundwater. Two-model factor analysis explained around 50% of total variance of the data sets and enabled identification of the different geochemical processes responsible for higher As concentrations, i.e. decoupled Fe and As reduction and desorption. Using discriminant analysis, a three-parameter discriminant function was derived: electrical conductivity, nitrate and bromide, which yielded highly accurate classification of the samples according to the concentration of As as As-safe (<10µg/L) and As contaminated (>10µg/L). A health risk assessment model was applied to calculate cumulative exposure to As as well as toxic and carcinogenic risks resulting from drinking raw groundwater contaminated by As in Eastern Croatia. Although the results obtained indicate that adverse health effects could be observed among the residents of the villages in which raw groundwater with higher As concentrations has been used, there are no reported cases of arsenicosis.

Animal model for age- and sex-related genotoxicity of diethylstilbestrol.

Environmental xenoestrogens pose a significant health risk for all living organisms. There is growing evidence concerning the different susceptibility to xenoestrogens of developing and adult organisms, but little is known about their genotoxicity in pre-pubertal mammals. In the present study, we developed an animal model to test the sex- and age-specific genotoxicity of the synthetic estrogen diethylstilbestrol (DES) on the reticulocytes of 3-week-old pre-pubertal and 12-week-old adult BALB/CJ mice using the in vivo micronucleus (MN) assay. DES was administered intraperitoneally at doses of 0.05, 0.5, and 5 microg/kg for 3 days and animals were sampled 48, 72 and 96 h, and 2 weeks after exposure. Five animals were analyzed for each dose, sex, and age group. After the DES dose of 0.05 microg/kg, pre-pubertal mice showed a significant increase in MN frequency (P < 0.001), while adults continued to show reference values (5.3 vs 1.0 MN/1000 reticulocytes). At doses of 0.5 and 5 microg/kg, MN frequency significantly increased in both age groups. In pre-pubertal male animals, MN frequency remained above reference values for 2 weeks after exposure. Our animal model for pre-pubertal genotoxicity assessment using the in vivo MN assay proved to be sensitive enough to distinguish age and sex differences in genome damage caused by DES. This synthetic estrogen was found to be more genotoxic in pre-pubertal mice, males in particular. Our results are relevant for future investigations and the preparation of legislation for drugs and environmentally emitted agents, which should incorporate specific age and gender susceptibility.

Preliminary study of cytogenetic damage in personnel exposed to anesthetic gases.

Occupational exposure to anesthetic gases is associated with various adverse health effects. Genetic material has been shown to be a sensitive target of numerous harmful agents. The aim of this study was to examine whether chromosomal damage could serve to indicate exposure to anesthetics. A group of 43 hospital workers of three professions (anesthesiologists, technicians and operating room nurses) and 26 control subjects were examined for chromosome aberrations, sister chromatid exchanges and micronucleus frequency. The exposed groups matched in duration of exposure to anesthetics, but not in age. An equal ratio between women and men was possible in all groups except nurses. Likewise, the ratio between smokers and non-smokers was also not comparable. An increase in chromosome damage was found in all exposed groups. While the increase in sister chromatid exchange frequency was not significant, chromosome aberrations and micronucleus frequency increased significantly, showing higher rates in women. The results suggest that the micronucleus test is the most sensitive indicator of changes caused by anesthetic gases. The observed difference between sexes with respect to exposure risk call for further, targeted investigations.

Variation in survival in coastal and continental regions of Croatia--results of a longitudinal study.

After 25 years of follow-up, regional variations in survival were analysed on a sample of 3343 participants (1780 female, 1563 male) from three urban and three rural municipalities in Croatia. Age of participants was in the range 35-54 years at the beginning of the study (1969). Cox regression for general mortality singled out one continental rural municipality (Virovitica) with the lowest survival in both genders. The relationship between the risk of death and age at the beginning of the study was approximately linear throughout its range for men, and after the age of 45 for women. Men showed a trend of better survival in the coastal region, which was consistent with findings of a similar concurrent study of rural Croatian population.

Survival of AIDS patients in Croatia prior to the introduction of combined antiretroviral therapy with protease inhibitors.

We report our experience on survival of adults with AIDS, treated at the University Hospital of Infectious Diseases, Zagreb, Croatia from October 1986 to December 1998. The median survival of our 116 patients was 15.8 months. Multivariate analysis showed that factors independently associated with survival were type of presenting AIDS indicator disease and CD4+ cell count.

Animal model for age- and sex-related genotoxicity of diethylstilbestrol

Environmental xenoestrogens pose a significant health risk for all living organisms. There is growing evidence concerning the different susceptibility to xenoestrogens of developing and adult organisms, but little is known about their genotoxicity in pre-pubertal mammals. In the present study, we developed an animal model to test the sex- and age-specific genotoxicity of the synthetic estrogen diethylstilbestrol (DES) on the reticulocytes of 3-week-old pre-pubertal and 12-week-old adult BALB/CJ mice using the in vivo micronucleus (MN) assay. DES was administered intraperitoneally at doses of 0.05, 0.5, and 5 µg/kg for 3 days and animals were sampled 48, 72 and 96 h, and 2 weeks after exposure. Five animals were analyzed for each dose, sex, and age group. After the DES dose of 0.05 µg/kg, pre-pubertal mice showed a significant increase in MN frequency (P < 0.001), while adults continued to show reference values (5.3 vs 1.0 MN/1000 reticulocytes). At doses of 0.5 and 5 µg/kg, MN frequency significantly increased in both age groups. In pre-pubertal male animals, MN frequency remained above reference values for 2 weeks after exposure. Our animal model for pre-pubertal genotoxicity assessment using the in vivo MN assay proved to be sensitive enough to distinguish age and sex differences in genome damage caused by DES. This synthetic estrogen was found to be more genotoxic in pre-pubertal mice, males in particular. Our results are relevant for future investigations and the preparation of legislation for drugs and environmentally emitted agents, which should incorporate specific age and gender susceptibility.