Exposure to low-frequency electromagnetic fields and the process of carcinogenesis

Danas se u znanstvenoj literaturi i posebice u javnim medijima posvećuje sve veća pozornost mogućim učincima izlaganja električnim i magnetskim poljima niskih frekvencija na zdravlje. Eksperimentalna istraživanja na razini stanica i in vivo istraživanja na životinjama pokazala su različite biološke učinke koji bi se mogli povezati s učincima izlaganja ljudi niskim frekvencijama. lako točan mehanizam ovog odnosa još nije potpuno jasan, istraživanja upućuju na to da niske frekvencije možda pomiču proces karcinogeneze, ali ne izgleda vjerojatno da su i začetnik u pojavi karcinoma. U pedesetak epidemioloških istraživanja ispitivana je moguća povezanost izlaganja ljudi niskim frekvencijama i pojave karcinoma u dječjoj i u odrasloj dobi. Nekoliko epidemioloških ispitivanja otkrilo je moguću povezanost između pojave karcinoma u dječjoj dobi i udaljenosti od električnih konstrukcija, prijenosnih i raspodjelnih linija. lako rezultati upućuju na povezanost izloženosti električnim i magnetskim poljima niskih frekvencija i pojave raka, potrebna su daljnja istraživanja. U međuvremenu, preporuča se tzv. »oprezno izbjegavanje« produženog izlaganja elektromagnetskim poljima niskih frekvencija.In the literature as well as in public media increasing attention is paid to possible health effects of exposure to low-frequency electric and magnetic fields. Experimental studies at the cellular level and mammalian studies in vivo have demonstrated various biological effects that are possibly associated with human exposure to low-frequency radiation. Although the exact mechanism of this relationship is not entirely clear, it has been indicated that low-frequency radiation might promote the process ol carcinogenesis, although it does not seem likely to initiate it. A possible link between human low-frequency exposure and occurrence of carcinoma at child and adult age has been examined in some fifty epidemiological studies. A few studies have demonstrated a possible connection between carcinoma at child age and distance from electrical installations. Although the results point to an association between exposure to low-frequency electric and magnetic fields and cancer, further research is called for. In the meantime "cautious avoidance" of extended exposure to low-frequency electromagnetic fields is recommended

Radiološka snimanja u trudnoći

There are many false assumptions, both in the general population and among physicians, regarding the influence of radiation on pregnant patients and the fetus during diagnostic procedures, in spite of scientific facts based on studies. These false assumptions are mostly based on the idea that every diagnostic procedure using ionizing radiation is a cause for serious concern and that artificial abortion as a possible solution might be considered. We analyzed data from counseling of pregnant patients exposed to ionizing radiation during diagnostic procedures in the Merkur University Hospital during a 4-year period. In this period, 26 patients presented for counseling after exposure to diagnostic ionizing radiation during pregnancy. Results showed most of these patients to have been exposed to radiation between the 2nd and 3rd week of gestation (36%), between the 4th and 5th week 32%, before the 2nd week 24%, and after the 6th week of gestation less than 8%. To provide reasonable estimate of fetal doses, Report No. 174 from the National Council on Radiation Protection and Measurements (NCRP) was used. Data from the Report include estimate of the fetal dose from direct and indirect exposures. Th e mean doses were up to 0.01 cGy in 46.2%, 0.01-0.15 cGy in 19.2%, 0.2-1 cGy in 26.9% and 1 cGy or more in 7.7% of patients. None of the counseled patients had medical indication for abortion, even though in a small percentage of patients abortion was a personal subjective decision. Considering that there are no Croatian guidelines for counseling patients exposed to ionizing radiation during pregnancy, it is recommended to use the International Commission on Radiological Protection guidelines in the management of pregnant patients exposed to ionizing radiation.Usprkos znanstvenim spoznajama temeljenim na dugogodišnjim studijama utjecaja zračenja u dijagnostičke svrhe na trudnicu i plod o toj temi vladaju zablude kako u općoj populaciji tako i među liječnicima. Te se zablude odnose uglavnom na razmišljanje o svakoj dijagnostičkoj pretrazi koja rabi ionizirajuće zračenje kao o razlogu za ozbiljnu zabrinutost i razmatranje artificijelog pobačaja kao mogućeg rješenja. Analizirali smo podatke savjetovanja trudnica ozračenih u dijagnostičke svrhe u KB Merkur kroz razdoblje od 4 godine. U tom razdoblju savjetovalo se 26 trudnica ozračenih u dijagnostičke svrhe u našoj ustanovi. Rezultati su pokazali da je najveći broj trudnica, njih 36%, ozračen između 2. i 3. tjedna gestacije, između 4. i 5. tjedna 32%, do 2. tjedna 24%, a iznad 6. tjedna gestacije njih manje od 8%. Za izračun fetalnih doza korišten je Izvještaj 174 Nacionalnog vijeća za zaštitu od zračenja i mjerenja zračenja. Podaci iz izvještaja omogućuju procjenu doze izračun koje uzima u obzir izravnu i neizravnu izloženost za sve postupke. Prosječne doze bile su: do 0,01 cGy kod 46,2%; 0,01-0,15 cGy kod 19,2%; 0,2-1 cGy kod 26,9%; 1 cGy i više kod 7,7% trudnica. Niti jedna savjetovana trudnica nije imala medicinsku indikaciju za pobačaj, makar je u malom postotku slučajeva pobačaj bio osobna subjektivna odluka. S obzirom na to da ne postoje hrvatske smjernice za savjetovanje trudnica ozračenih u dijagnostičke svrhe preporuka je koristiti smjernice ICRP vezane za medicinske indikacije pobačaja kod određenih doza zračenja

Cytogenetic Follow-Up in Testicular Seminoma Patients Exposed to Adjuvant Radiotherapy

Early stage testicular seminoma is a radiosensitive tumor. Its incidence has significantly increased during the last decade especially in the young population. Although the therapy for testicular seminoma gives very satisfying results, the evaluation of genome damage caused by the therapy is of a great importance in order to recognize possible related health risks. The present study was performed on ten patients diagnosed with seminoma stage I; pT1/2N0M0S0, treated with adjuvant radiotherapy (a radiation dose of 25 Gy divided in 16 fractions) after orchidectomy. To assess the possible existence of an increased baseline DNA/chromosome damage in patients we also selected the appropriate control group of ten healthy men. The levels of primary DNA/chromosome damage in peripheral blood lymphocytes, as well as the dynamics of their repair were studied using the alkaline comet assay, chromosome aberration and cytokinesis-block micronucleus assay. Altogether four blood samples per patient were collected in the course of the therapy: before and after receiving the first dose of radiotherapy, in the middle of the radiotherapy cycle, and after the last dose of radiotherapy. Other two follow-up blood samples were collected six and twelve months after the cessation of therapy. As observed, the administration of the first radiation dose significantly increased the levels of DNA damage in almost all patients compared to their baseline values. Specific patterns of DNA damage were recorded in samples analyzed in the middle of radiotherapy and after receiving the last dose, indicating the possibility of an adaptive response in some patients. The levels of chromosomal aberrations and the incidence of micronuclei also increased in the course of therapy but gradually declined during the follow-up period. Our results confirmed the existence of post-irradiation damage in peripheral blood lymphocytes (and possibly in other non-target cells) of cancer patients which may represent a risk for the secondary cancer development. Considering that the majority of patients with testicular cancer are of a younger age, they represent a population deserving special attention. As cytogenetic screening may detect high-risk individuals, it might be useful in regular medical monitoring of seminoma patients after the successful therapy

Cytogenetic Follow-Up in Testicular Seminoma Patients Exposed to Adjuvant Radiotherapy

Early stage testicular seminoma is a radiosensitive tumor. Its incidence has significantly increased during the last decade especially in the young population. Although the therapy for testicular seminoma gives very satisfying results, the evaluation of genome damage caused by the therapy is of a great importance in order to recognize possible related health risks. The present study was performed on ten patients diagnosed with seminoma stage I; pT1/2N0M0S0, treated with adjuvant radiotherapy (a radiation dose of 25 Gy divided in 16 fractions) after orchidectomy. To assess the possible existence of an increased baseline DNA/chromosome damage in patients we also selected the appropriate control group of ten healthy men. The levels of primary DNA/chromosome damage in peripheral blood lymphocytes, as well as the dynamics of their repair were studied using the alkaline comet assay, chromosome aberration and cytokinesis-block micronucleus assay. Altogether four blood samples per patient were collected in the course of the therapy: before and after receiving the first dose of radiotherapy, in the middle of the radiotherapy cycle, and after the last dose of radiotherapy. Other two follow-up blood samples were collected six and twelve months after the cessation of therapy. As observed, the administration of the first radiation dose significantly increased the levels of DNA damage in almost all patients compared to their baseline values. Specific patterns of DNA damage were recorded in samples analyzed in the middle of radiotherapy and after receiving the last dose, indicating the possibility of an adaptive response in some patients. The levels of chromosomal aberrations and the incidence of micronuclei also increased in the course of therapy but gradually declined during the follow-up period. Our results confirmed the existence of post-irradiation damage in peripheral blood lymphocytes (and possibly in other non-target cells) of cancer patients which may represent a risk for the secondary cancer development. Considering that the majority of patients with testicular cancer are of a younger age, they represent a population deserving special attention. As cytogenetic screening may detect high-risk individuals, it might be useful in regular medical monitoring of seminoma patients after the successful therapy

T-2 toksin - pojavnost i toksičnost u peradi

T-2 toxin is the most toxic type A trichothecene mycotoxin. It is the secondary metabolite of the Fusarium fungi, and is common in grain and animal feed. Toxic effects have been shown both in experimental animals and in livestock. It has been implicated in several outbreaks of human mycotoxicoses. Toxic effects in poultry include inhibition of protein, DNA, and RNA synthesis, cytotoxicity, immunomodulation, cell lesions in the digestive tract, organs and skin, neural disturbances and low performance in poultry production (decreased weight gain, egg production, and hatchability). Concentrations of T-2 toxin in feed are usually low, and its immunosuppressive effects and secondary infections often make diagnosis difficult. If at the onset of the disease, a change in diet leads to health and performance improvements in animals, this may point to mycotoxin poisoning. Regular control of grain and feed samples is a valuable preventive measure, and it is accurate only if representative samples are tested. This article reviews the incidence and toxic effects of T-2 toxin in poultry.T-2 toksin je najtoksičniji predstavnik trikotecenskih mikotoksina tipa A. On je sekundarni produkt metabolizma plijesni roda Fusarium i često je prisutan u žitaricama i hrani za životinje. Štetni učinci uočeni su u eksperimentalnih životinja i životinja u uzgoju. On se povezuje s pojavom bolesti ljudi od mikotoksikoza. Učinci toksina u peradi su višestruki: inhibicija sinteze proteina, DNA i RNA, citotoksični učinak, imunomodulatorni učinak, oštećenje stanica probavnog sustava, organa i kože, živčani poremećaji te pad proizvodnih karakteristika u uzgoju peradi (slabiji prirast, pad nesivosti i valivosti). Koncentracije T-2 toksina u hrani redovito su vrlo malene, a zbog imunosupresivnog djelovanja toksina te istodobne sekundarne infekcije bolest se često teško dijagnosticira. Pri pojavi bolesti promjenom hrane može doći do poboljšanja zdravstvenog stanja, što tako|er upućuje na moguće trovanje mikotoksinima. Redovita kontrola uzoraka žitarica i hrane za životinje jedna je od preventivnih mjera, a detekcija mikotoksina u žitaricama i hrani pouzdana je samo ako se ispituje reprezentativan uzorak. U radu su opisani učestalost i toksični učinci T-2 toksina u peradi

Procjena citogenetičkog statusa u ljudskim limfocitima nakon izloženosti visokim koncentracijama pčelinjeg otrova u uvjetima in vitro

Several studies have reported radioprotective, antimutagenic, anti-infl ammatory, antinociceptive, and anticancer effects of bee venom both in the cell and the whole organism. The aim of this study was to assess the effects of a single high dose of 100 µg mL-1 of whole bee venom in human lymphocytes in vitro over a variety of time spans (from 10 min to 24 h). After the treatment, we used the comet assay and micronucleus test to see the effect of bee venom on the cell. The comet assay confi rmed that the venom damaged the DNA molecule. Tail length, tail intensity, tail moment showed a signifi cant increase (P<0.05). The percentage of long-tailed nuclei (LTN) with the tail length exceeding the 95th percentile also increased in a time-dependent manner. The micronucleus parameters (number of micronuclei, nucleoplasmic bridges, and nuclear buds) also showed a signifi cant time-dependent increase (P<0.05). This research indicates that high concentrations of bee venom can lead to cellular instability. Further research is needed to understand the mechanism of action of bee venom and its components in human cells and to see if this natural product may fi nd application in medicine.Cilj ovog istraživanja je procjena staničnog statusa ljudskih limfocita periferne krvi nakon tretmana visokom koncentracijom pčelinjeg otrova u in vitro uvjetima primjenom alkalnog kometnog testa i mikronukleusnog testa. Limfociti su bili izloženi pčelinjem otrovu u koncentraciji od 100 µg mL-1 u različitom vremenu (od 10 min do 24 h). Rezultati kometnog testa upućuju na oštećenje molekule DNA povećanjem parametara kometnog testa (dužina repa, intenzitet repa i repni moment) te prisutnost limfocita s visokom učestalosti kometa s dugim repovima (LTN). U tim stanicama učestalost LTN premašuje 95 % ukupne raspodjele vrijednosti LTN dobivene za sve stanice kontrolnog uzorka. Parametri mikronukleusnog testa (broj mikronukleusa, nukleoplazmatski mostovi i nuklearni pupovi) također pokazuju značajan porast u odnosu na odgovarajući kontrolni uzorak (P<0,05). Rezultati dobiveni ovim tehnikama upućuju na to da pčelinji otrov u visokoj koncentraciji uzrokuje staničnu nestabilnost te na potrebu daljnjih istraživanja mehanizama djelovanja pčelinjeg otrova i njegovih sastavnica na ljudske stanice u svrhu primjene prirodnih spojeva posebice u medicinskoj praksi

Evaluation of DNA damage in white blood cells of healthy human volunteers using the alkaline comet assay and the chromosome aberration test

The present study was undertaken to contribute to the characterization of the degree of variability in baseline damage in white blood cells from control population, and to investigate how this variability is associated with external and internal factors. Altogether 170 healthy volunteers, randomly selected from the general population of the Republic of Croatia, participated in the study. Two sensitive tests: the alkaline comet assay and the chromosome aberration test were applied to study the background levels of DNA damage in their white blood cells. The results point to inter-individual differences, indicating different genome sensitivity. As revealed by both assays, the background levels of DNA damage were mostly influenced by smoking habit as well as medical exposure (especially to diagnostic X-rays). Sex and age of subjects did not significantly influence the values of DNA damage recorded in the white blood cells. Although higher levels of DNA damage were recorded in blood samples collected during winter and autumn, they were mostly influenced by medicinal exposure and smoking habit. Statistical evaluation of the data confirmed that a positive correlation exists between DNA migration and the number of long-tailed nuclei found with the comet assay and the total number of chromosome aberrations. The data obtained can serve as control values in forthcoming biomonitoring studies