Methadone maintenance treatment and drugs.

The mental and physical capabilities of drivers in traffic are often seriously challenged these days. Not only do they need to concentrate on driving, predict connections between various phenomena, take appropriate judgements in current situations and foresee the sequence of measures to be taken, but they are also expected to be emotionally stable, etc. The problem with drugs in traffic is often encountered when assessing the actual safe driving capability of a person in a given moment, for example after a car accident or a police check, or medical check-ups that are required for a driving license. The Road Traffic Safety Law considers methadone a drug. Drug addicts do not meet the health standards required of drivers. This research program deals with the attitude of drivers who are in methadone maintenance treatment programs with respect to the driving ability as well as the effects of methadone use in combination with other drugs on driving. It has been established that drivers undergoing the methadone maintenance program, regularly drive not only under the influence of methadone but also under the influence of marijuana (20%) and heroin (18%) and sometimes under the influence of marijuana (58.6%), heroin (55.7%), and alcohol (48.6%). Certain initiatives have been taken by some therapists to give, under certain circumstances, a clean bill of health to responsible methadone maintenance patients who have an adequate level of responsibility for themselves and their deeds, in order to help them obtain a driving license. Since it has been established that methadone maintenance patients use methadone quite commonly in combination with illegal drugs and/or alcohol, the classification of this type of addicts among possible driving candidates remains disputable. Long term interdisciplinary research is still required to determine the basic principles required to asses and possibly admit this type of drivers to participate in traffic, as well as to determine which professional therapists can participate and evaluate the driving capabilities of these patients.

Incidence of chromosomal aberrations and micronuclei in cave tour guides.

An analysis of structural chromosomal aberrations (SCA) and micronucleus tests (MN) were performed in 38 subjects, cave tour guides and in appropriate control group. The dominant type of chromosomal aberrations in tourist guides were chromosomal breaks (0.013 per cell) and acentric fragments (0.011 per cell). In the control group, these aberrations were present up to 0.008 on cells. Considering the analysed cells of the guides in total (33,556), the incidence of dicentric and rings range is below 0.0008 on cells, even though three dicentric and ring chromosoms were found already in the first 1000 in vitro metaphases of some guides. Only 0.0003 dicentrics and neither other translocations were found in control group (ambiental exposure). The incidence of micronuclei in cytokinesis blocked lymphocytes ranged from 12-32 per 500 CB cells in the cave tour guides and from 4-11 per 500 CB cells in control group. Measurements of radon and its daughters were performed at different locations in the cave. Annual doses from 40-60 mSv were estimated per 2000 work hours for cave guides. The changes found in the genome of somatic cells may be related to the exposure doses of radon and its daughters, although smoking should not be ignored.

Genotoxic effects of radiotherapy and chemotherapy on circulating lymphocytes in patients with Hodgkin's disease.

PURPOSE: The aim of this study was to find out the structural chromosomal changes in somatic cells after chemotherapy (CT) with or without radiotherapy (RT). METHODS AND MATERIALS: This prospective study included 30 Hodgkin's disease (HD) patients. The patients of Group I(1) had only MOPP/ABV CT. The patients of Group II(2) also had irradiation. Group III(3) (control group) consisted of healthy subjects without any reported malignant disease. Mutagenetic testing was performed at the time of diagnosis and was repeated immediately after treatment and again 6 months later. The following tests were applied: structural chromosomal aberrations (CA), sister chromatid exchange (SCE) and micronucleus (MN) tests. RESULTS: Prior to treatment, the chromosome damage in our patients was not higher than that in the control group. Immediately after the complete treatment, we observed a strong inhibition of the mitotic activity of lymphocytes as well as a significant increase in the frequency of CA, MN and SCE in the Groups I and II. In patients treated by RT, we found statistically significant differences between the Groups I and II in MN (P<0.005) and CA frequencies (P<0.005), and an increased number of dicentrics (P=0.021). Six months after the complete treatment, the mitotic activity was found to be nearly normal, but chromosome damage occurred. CA and SCE values did not differ much from the values measured immediately after treatment, whereas MN values decreased without returning to the baseline levels. The chromosome damage persisted even 6 months after combined RT and CT. The damage in the genome of individual cells was in some cases even greater than immediately after treatment. The possible risk of neoplastic transformation posed by these heavily damaged cells, if viable, due to the changes in the expression of oncogenes or tumour suppresser genes, is discussed.

Location and incidence of chromosome and chromatid breaks in patients with Hodgkin's disease or testicular tumors.

In 90 patients aged 17 to 35 who suffered from Hodgkin's disease (HD) or had testicular tumors (TT), the location of chromosome and chromatid breaks on individual chromosome segments was reviewed using an adapted Funes-Cravioto scheme, in addition to examining the percentage of structural chromosomal aberrations. On the basis of an analysis of 1121 breaks in patients with HD or TT, the results were presented graphically as multiples of the expected number of breaks for the normal population. Before the beginning of treatment, the number of structural chromosomal aberrations (SCA) in patients with TT or HD was equal to that in a control group of subjects with malignant diseases. This, however, does not apply to the location of chromosome and chromatid breaks. In patients with HD, the dominant unstable sites are located on group A2 chromosomes, segments 2 and 5, and on group B chromosomes, segment 5. In patients with TT, the number of chromosome and chromatid breaks is also increased on group A2 chromosomes, segments 2 and 5, and in addition, also on group B chromosomes, segment 4.

Chromosomal changes in somatic cells in seminoma patients after treatment with ionizing radiation or cytostatics.

Seminomas are sensitive to both ionizing radiation and cytostatic drugs. The study's objective was to find out the effects of cytostatics or ionizing radiation by comparing the results of genome testing before treatment and immediately afterwards. Repeat cytogenetic testing six months after completion of treatment was used to find out changes resulting from reparatory processes after various types of treatment and the degree of elimination of defective lymphocytes from circulation. Three cytogenetic tests were used in our study to find out structural changes in chromosomes (percentage of aberrations), sister chromatid exchanges (SCE) and the number of micronuclei in binuclear lymphocytes (MN). In patients treated with ionizing radiation, strong inhibition of the mitotic activity of lymphocytes occurred after irradiation of para-aortal and ipsilateral inguinal lymph nodes. However, it is difficult to make a connection between the mitotic activity of lymphocytes and their total number, which was found to be within a normal range throughout the study. There is, therefore, another possibility, i.e. that this process actually involves impairment of intracellular enzymes and blockage of the synthesis of macromolecules in lymphocytes which have suffered a large degree of genome damage. Six months after a completed course of irradiation, mitotic activity was found to be mostly normal; however, there was still a very high percentage of aberrations compared with group II (patients treated with a cytostatic, paraplatin) or with respect to the control group, in which the average percentage of aberrations was 1.42 (excluding dicentrics and rings, which are found in all irradiated patients). From the cytological-mutagenetic point of view, chemotherapy proved to be less aggressive to patients. The results of recovery were visible earlier and the elimination of damaged cells was quicker.