Procjena genotoksičnosti bleomicina i mitomicina C metodom kometnog testa

Although chemotherapy targets cancer tissue, it also damages the DNA of non-cancer cells. The aim of this study was to evaluate the in vitro genotoxic potential of therapeutic concentrations of bleomycin and mitomycin C, added alone or in combination to cultures of human peripheral lymphocytes. The levels of DNA damage and repair were assessed using the alkaline comet assay immediately after cell treatment as well as 24 and 48 hours following treatment. The results indicate that individual drugs and their combination induce a significant DNA damage to peripheral blood lymphocytes. Bleomycin alone induced the highest levels of primary DNA damage immediately after cell treatment. Although mitomycin C alone induced massive cross-linking and retarded DNA migration in resting cells, active proliferation and repair processes significantly increased DNA damage. Combined, they showed a synergetic effect, inducing complex patterns of DNA damage in peripheral blood lymphocytes and producing different types of lesions and a number of DNA alterations that directly or indirectly increased DNA migration. Our study has confirmed the sensitivity of the alkaline comet assay for assessing bleomycin and/or mitomycin C genotoxicity to human lymphocytes at concentration levels used in clinic. It has also demonstrated the utility of the alkaline comet assay as one of the primary screening methods for in vitro studies of drug-DNA interactions, especially in studying mechanisms of action of new drugs.Većina antineoplastičnih lijekova ima nespecifično djelovanje pa su na njihovu primjenu osjetljive i stanice zdravog tkiva. U pretkliničkim istraživanjima lijekova važnu ulogu imaju brzi i osjetljivi testovi za procjenu razina oštećenja i popravka stanične DNA. Cilj istraživanja bio je procijeniti toksičke učinke bleomicina i mitomicina C na genom ljudskih limfocita u uvjetima in vitro primjenom kometnog testa u alkalnoj izvedbi. Limfociti su 24 h izlagani pojedinačnim lijekovima te njihovoj kombinaciji u terapijskim koncentracijama, a potom je praćena dinamika oštećenja i popravka DNA. Postavljena su dva pokusa: (A) u kojem su lijekovi dodavani u trenutku uspostavljanja staničnih kultura kako bi se procijenili toksički učinci na limfocite u fazi mirovanja i početnim fazama rasta, i (B) u kojem su lijekovi dodavani nakon 24 h rasta stanica u kulturi, kako bi se istražili učinci na stanice u diobi. Rezultati istraživanja pokazuju da oba lijeka izazivaju značajna primarna oštećenja limfocitne DNA. Razine oštećenja i dinamika njihova popravka ovisne su o diobenoj aktivnosti limfocita i njihovu položaju unutar staničnog ciklusa. Oštećenja izazvana bleomicinom vrlo su jaka neposredno nakon tretmana, a u kasnijim fazama rasta limfocita većinom se popravljaju. Mitomicin C izaziva drukčiji obrazac oštećenja i popravka DNA. Zbog ukriženog povezivanja između lanaca DNA, on značajno usporava migraciju DNA tijekom elektroforeze u alkalnim uvjetima, a visoke razine oštećenja koje se detektiraju u kasnijim fazama rasta uzrokovane su procesima popravka DNA. Bleomicin i mitomicin C sinergistički izazivaju opsežna oštećenja limfocitne DNA, osobito u diobeno aktivnim stanicama. Dobiveni rezultati govore u prilog primjene kometnog testa u pretkliničkim istraživanjima antineoplastičnih lijekova i upućuju na moguću primjenu ove metode u procjeni oštećenja genoma proizašlih iz izloženosti ovim agensima

Različiti učinci samih hlapljivih anestetika ili u kombinaciji s gama-zračenjem od 1 i 2 Gy in vivo na DNA mišje jetre: preliminarno istraživanje

As the number of radiotherapy and radiology diagnostic procedures increases from year to year, so does the use of general volatile anaesthesia (VA). Although considered safe, VA exposure can cause different adverse effects and, in combination with ionising radiation (IR), can also cause synergistic effects. However, little is known about DNA damage incurred by this combination at doses applied in a single radiotherapy treatment. To learn more about it, we assessed DNA damage and repair response in the liver tissue of Swiss albino male mice following exposure to isoflurane (I), sevoflurane (S), or halothane (H) alone or in combination with 1 or 2 Gy irradiation using the comet assay. Samples were taken immediately (0 h) and 2, 6, and 24 h after exposure. Compared to control, the highest DNA damage was found in mice receiving halothane alone or in combination with 1 or 2 Gy IR treatments. Sevoflurane and isoflurane displayed protective effects against 1 Gy IR, while with 2 Gy IR the first adverse effects appeared at 24 h post-exposure. Although VA effects depend on liver metabolism, the detection of unrepaired DNA damage 24 h after combined exposure with 2 Gy IR indicates that we need to look further into the combined effects of VA and IR on genome stability and include a longer time frame than 24 h for single exposure as well as repeated exposure as a more realistic scenario in radiotherapy treatment.Kako se broj radioterapijskih i radioloških dijagnostičkih postupaka iz godine u godinu povećava, tako raste i primjena hlapljivih anestetika za opću anesteziju. Iako se smatralo sigurnim, izlaganje hlapljivim anesteticima može izazvati različite štetne učinke, a u kombinaciji s ionizirajućim zračenjem može izazvati i sinergijske učinke. Međutim, malo se zna o oštećenju DNA koje uzrokuje ova kombinacija u dozama primijenjenima u jednom izlaganju u radioterapiji. Kako bismo saznali više o tome, alkalnim komet-testom analizirali smo oštećenje DNA i odgovor na popravak u jetrenom tkivu muških Swiss albino miševa nakon izlaganja samo izofluranu, sevofluranu ili halotanu, odnosno u kombinaciji sa zračenjem od 1 ili 2 Gy. Uzorci su uzeti odmah (0 h) te 2, 6 i 24 sata nakon izlaganja. U usporedbi s kontrolom, najveća oštećenja DNA utvrđena su u miševa koji su primili halotan, sam ili u kombinaciji sa zračenjem od 1 ili 2 Gy. Sevofluran i izofluran pokazali su zaštitne učinke nakon izlaganja zračenju od 1 Gy, a pri 2 Gy prve nuspojave pojavile su se 24 sata nakon izlaganja. Iako učinci hlapljivih anestetika ovise o metabolizmu jetre, otkrivanje nepopravljenog oštećenja DNA 24 sata nakon kombinirane izloženosti sa zračenjem od 2 Gy upućuje na to da trebamo nastaviti istraživati kombinirane učinke hlapljivih anestetika i ionizirajućega zračenja na stabilnost genoma i obuhvatiti šire razdoblje nakon jednokratne izloženosti (duže od 24 sata). Također treba obuhvatiti višekratna izlaganja kao realističniji scenarij u liječenju radioterapijom

Utjecaj majčinih i fetalnih faktora na uspješnost medikamentozne indukcije poroda

Labour induction is the process in which labour is induced mechanically or pharmacologically. The percentage of induced labours is between 1.4% and 32% of the total number of births in the world. The aim of this research is to present the number of medically induced labours from 2012 to 2019 at the Clinic for Gynaecology and Obstetrics of the Clinical Hospital Center in Osijek and to present the success rate of medically induced labour and factors, both maternal and/or foetal which may affect it. Materials and methods: In the study 2361 subjects were included whose births were induced by medication regardless of the indication for medically induced labour, gestational age or mother’s age. χ2 test, Mann Whitney U test, Fisher’s exact test, Kruskal Wallis test (Pot Hoc Conover), and the univariate and multivariate logistic regression model were used. Results: The percentage of inductions was 13.8%. 81% of the child births was completed vaginally , while 19% was completed by the caesarean section. The univariate regression analysis found that meconium amniotic fluid increases the risk of the caesarean section after the labour has been induced. Factors decreasing the possibility of the caesarean section after induced labour include multiparity, women age between 25 and 35 years and women bearing female children. The multivariate statistical regression model found that women over the age of 36 are 1.58 times more likely to have the caesarean section. Women with meconium amniotic fluid are 1.47 times more likely to have the caesarean section. Multiparity in the mother and the female sex of the child reduce the probability of the caesarean section after induced labour (odds ratio (OR) 0.20, P=0.02 and OR 0.84, P=0.09, respectively). Conclusion: The study indicates that multiparity and female gender of child increase the probability of the vaginal birth after the induction, while the mother’s age over 36 and meconium amniotic fluid after the induction increase the risk of the caesarean section.Indukcija poroda postupak je kojim mehaničkim ili farmakološkim putem pokušavamo potaknuti porod. Postotak induciranih porođaja u svijetu mjeri se od 1,4 do čak 32 % od ukupnog broja poroda. Cilj je ovog preglednog rada prikazati broj medikamentozno induciranih poroda u razdoblju od 2012. do 2019. godine na Klinici za ginekologiju Kliničkog bolničkog centra u Osijeku, prikazati uspješnost medikamentozne indukcije poroda te koji od materničnih i/ili fetalnih faktora mogu utjecati na uspjeh indukcije poroda. Materijali i metode: Koristili smo podatke iz rađaonskog protokola Klinike za ginekologiju i porodništvo Kliničkog bolničkog centra u Osijeku. U istraživanje smo uključili 2361 ispitanicu čiji su porodi inducirani medikamentozno. Statistički smo obradili podatke o vrsti indukcije poroda, indikacijama za indukciju poroda te načinu poroda nakon indukcije. Koristili smo χ2 test, Mann Whitney U test, Fisherov egzaktni test, Kruskal Wallis test (Pot Hoc Conover) te model univarijantne i multivarijantne logističke regresije. Rezultati: Postotak indukcija bio je 13,8 %. U 81 % slučajeva porod je dovršen vaginalnim putem, dok je u 19 % slučajeva dovršen carskim rezom. Utvrdili smo da je čimbenik rizika za carski rez nakon indukcije poroda dijagnoza mekonijske plodove vode, dok su čimbenici koji smanjuju vjerojatnost carskog reza – dob majke od 25 do 35 godina, trudnice koje su rodile žensko dijete te trudnice koje su do sada već rađale. Modelom multivarijantne statističke regresije utvrdilo se da žene u dobi iznad 36 godina imaju 1,58 puta veću šansu za carski rez u odnosu na mlađe, a one s prisutnom dijagnozom mekonijske plodove vode 1,47 puta veću šansu za carski rez u odnosu na one koje nemaju navedenu dijagnozu. Multiparitet u majke te ženski spol djeteta smanjuju vjerojatnost carskog reza nakon indukcije poroda (redom OR 0.20, P = 0.02 te OR 0.84, P = 0.09). Zaključak: Studija je pokazala da su multiparitet i ženski spol djeteta protektivni faktori za vaginalni porod, dok su dob majke iznad 36 godina te zelena plodna voda nakon indukcije poroda rizični faktori za carski rez

Utjecaj niskih doza klorpirifosa na krvne i stanice koštane srži štakora

The aim of this study was to investigate the genotoxic potential of low doses of chlorpyrifos (CPF) on blood and bone marrow cells in adult male Wistar rats. CPF was administered by oral gavage at daily doses of 0.010, 0.015, and 0.160 mg/kg of body weight (bw) for 28 consecutive days. Positive control (PC) was administered 300 mg/kg bw/day of ethyl methane sulphonate (EMS) for the final three days of the experiment. Toxic outcomes of exposure were determined with the in vivo micronucleus (MN) assay and alkaline comet assay. The 28-day exposure to the 0.015 mg/kg CPF dose, which was three times higher than the current value of acute reference dose (ARfD), reduced body weight gain in rats the most. The in vivo MN assay showed significant differences in number of reticulocytes per 1000 erythrocytes between PC and negative control (NC) and between all control groups and the groups exposed to 0.015 and 0.160 mg/kg bw/day of CPF. The number of micronucleated polychromatic erythrocytes per 2000 erythrocytes was significantly higher in the PC than the NC group or group exposed to 0.015 mg/kg bw/day of CPF. CPF treatment did not significantly increase primary DNA damage in bone marrow cells compared to the NC group. However, the damage in bone marrow cells of CPF-exposed rats was much higher than the one recorded in leukocytes, established in the previous research. Both assays proved to be successful for the assessment of CPFinduced genome instability in Wistar rats. However, the exact mechanisms of damage have to be further investigated and confirmed by other, more sensitive methods.Istražen je genotoksični potencijal niskih doza klorpirifosa na uzorcima krvi i stanica koštane srži u odraslih mužjaka štakora soja Wistar. Pokusnim je životinjama klorpirifos bio 28 dana oralno apliciran pomoću sonde u dnevnim dozama od 0,010 mg/kg t. m., 0,015 mg/kg t. m. i 0,160 mg/kg t. m. Kao pozitivna kontrola korišten je etil metan sulfonat (EMS) u dozi od 300 mg/kg t. m. tijekom posljednja tri dana pokusa. Toksični ishodi izloženosti klorpirifosu istraženi su primjenom in vivo mikronukleus (MN) testa i alkalnoga komet-testa. Utvrdili smo da je 28-dnevna izloženost klorpirifosu u dozi od 0,015 mg/kg t. m./dan, koja je trostruko viša od važeće vrijednosti akutne referentne doze, u najvećoj mjeri smanjila prirast tjelesne mase štakora. Rezultati MN-testa upućuju na značajne razlike u broju retikulocita na 1000 eritrocita između pozitivne i negativne kontrole te između obiju kontrola i skupina izloženih klorpirifosu u dnevnim dozama 0,015 i 0,160 mg/kg t. m. Broj polikromatskih eritrocita s mikronukleusima na 2000 eritrocita u pozitivnoj kontroli bio je značajno povećan u usporedbi s negativnom kontrolom te s uzorcima krvi štakora izloženih klorpirifosu u dnevnoj dozi od 0,015 mg/kg t. m. Izloženost CPF-u nije uzrokovala statistički značajan porast razine primarnih oštećenja DNA u stanicama koštane srži u usporedbi s razinama spontanih oštećenja DNA, izmjerenima alkalnim komet-testom u negativnoj kontroli. Međutim, razine oštećenja u stanicama koštane srži štakora izloženih klorpirifosu bile su značajno više od onih zabilježenih u leukocitima, koje su poznate iz prethodnih istraživanja. Oba su se testa pokazala uspješnima za procjenu nestabilnosti genoma izazvanih klorpirifosom u Wistar štakora. Međutim, točni mehanizmi oštećenja moraju se dodatno istražiti i potvrditi drugim osjetljivijim metodama

Oštećenje DNA stanica bubrega in vivo prouzročeno kombiniranim izlaganjem hlapljivim anesteticima i radioterapijskim dozama od 1 Gy ili 2 Gy

Patient immobilisation with volatile anaesthetics (VA) during radiotherapy is sometimes unavoidable. Although it is known that both Vas and ionising radiation can have nephrotoxic effects, there are no studies of their combined effects on DNA damage. The aim of this in vivo study was to address this gap by investigating whether 48 groups of healthy Swiss albino mice (totalling 240) would differ in kidney cell DNA damage response (alkaline comet assay) to isoflurane, sevoflurane, or halothane anaesthesia and exposure to 1 Gy or 2 Gy of ionising radiation. We took kidney cortex samples after 0, 2, 6, and 24 h of exposure and measured comet parameters: tail length and tail intensity. To quantify the efficiency of the cells to repair and re-join DNA strand breaks, we also calculated cellular DNA repair index. Exposure to either VA alone increased DNA damage, which was similar between sevoflurane and isoflurane, and the highest with halothane. In combined exposure (VA and irradiation with 1 Gy) DNA damage remained at similar levels for all time points or was even lower than damage caused by radiation alone. Halothane again demonstrated the highest damage. In combined exposure with irradiation of 2 Gy sevoflurane significantly elevated tail intensity over the first three time points, which decreased and was even lower on hour 24 than in samples exposed to the corresponding radiation dose alone. This study confirmed that volatile anaesthetics are capable of damaging DNA, while combined VA and 1 Gy or 2 Gy treatment did not have a synergistic damaging effect on DNA. Further studies on the mechanisms of action are needed to determine the extent of damage in kidney cells after longer periods of observation and how efficiently the cells can recover from exposure to single and multiple doses of volatile anaesthetics and radiotherapy.Imobilizacija bolesnika hlapljivim anesteticima (HA) tijekom radioterapije ponekad je neizbježna. Iako je poznato da i HA i ionizirajuće zračenje mogu imati nefrotoksične učinke, ne postoje istraživanja o njihovu kombiniranom učinku na oštećenje DNA bubrežnih stanica. Cilj ovog istraživanja in vivo na miševima soja Swiss albino bio je utvrditi oštećenje DNA stanica bubrega (alkalni komet-test) nakon anestezije izofluranom, sevofluranom ili halotanom i izlaganja ionizirajućem zračenju u dozama od 1 Gy ili 2 Gy. Uzorke bubrežnoga korteksa uzeli smo nakon 0, 2, 6 i 24 sata od izlaganja i izmjerili parametre komet-testa: duljinu repa i njegov intenzitet. Kako bismo kvantificirali učinkovitost staničnoga popravka, izračunali smo indeks popravka stanične DNA. Izloženost bilo kojem od testiranih anestetika povećalo je oštećenje DNA u odnosu na kontrolu, slično kod sevoflurana i izoflurana, a najveće kod halotana. U kombiniranom izlaganju HA-u i zračenju od 1 Gy, oštećenje DNA ostalo je na sličnim razinama u svim vremenskim točkama, ili je bilo čak niže od oštećenja prouzročenih samim zračenjem. Halotan je ponovno izazvao najveća oštećenja. U kombiniranom izlaganju sa zračenjem od 2 Gy sevofluran je značajno povećao intenzitet repa tijekom prvih triju vremenskih točaka, koji se smanjivao te je nakon 24 sata čak bio niži nego u uzorcima koji su bili izloženi samo zračenju. Potrebna su daljnja istraživanja mehanizma djelovanja kako bi se utvrdilo u kojoj mjeri oštećenja ostaju u bubrežnim stanicama nakon duljeg razdoblja, kao i koliko se učinkovito stanice mogu oporaviti nakon jednokratnog ili višekratnog izlaganja HA-u i zračenju

Are There Differences in Students’ School Success, Biorhythm, and Daytime Sleepiness Depending on Their School Starting Times?

Chronotype is a characteristic of a person in a certain point of one’s lifetime and it slowly changes with age. Adolescents start to go to bed later while schools impose early starting hours, which may become a problem for students who are unable to adapt their circadian rhythm. The aim of this study was to determine if differences in school starting times affect the students’ chronotype, school success, or daytime sleepiness. We tested a total of 1020 students from four high schools in Osijek, Croatia. The students had alternating school shifts (school starting hours 7 AM or 13 PM and 8 AM or 14 PM, every other week, alternatively, respectively). The participants were tested using the Epworth Sleepiness Scale and the Morningness – Eveningness Questionnaire. Earlier chronotypes were characteristic of the students starting school earlier, but without significant difference in daytime sleepiness in comparison with those starting school later. Differences were also found between different age and gender groups, female and older students having earlier chronotypes. Students going to school earlier showed better school success than the latter. In conclusion, the study shows that students starting school earlier also have earlier chronotypes, which might be consequence of the adaptation to one hour earlier school starting time

Polimorfizmi u genima za popravak DNA: poveznica s biomarkerima mikronukleus-testa u medicinskih radnika kronično izloženih niskim dozama ionizirajućeg zračenja

Individual sensitivity to ionising radiation (IR) is the result of interaction between exposure, DNA damage, and its repair, which is why polymorphisms in DNA repair genes could play an important role. We examined the association between DNA damage, expressed as micronuclei (MNi), nuclear buds (NBs), and nucleoplasmic bridges (NPBs) and single nucleotide polymorphisms in selected DNA repair genes (APE1, hOGG1, XRCC1, XRCC3, XPD, PARP1, MGMT genes; representative of the different DNA repair pathways operating in mammals) in 77 hospital workers chronically exposed to low doses of IR, and 70 matched controls. A significantly higher MNi frequency was found in the exposed group (16.2±10.4 vs. 11.5±9.4; P=0.003) and the effect appeared to be independent from the principal confounding factor. Exposed individuals with hOGG1, XRCC1, PARP1, and MGMT wild-type alleles or APEX1, as well as XPD (rs13181) heterozygous showed a significantly higher MNi frequency than controls with the same genotypes. Genetic polymorphism analysis and cytogenetic dosimetry have proven to be a powerful tool complementary to physical dosimetry in regular health surveillance programmes.Individualna osjetljivost na ionizirajuće zračenje rezultat je međudjelovanja samog izlaganja zračenju, oštećenja DNA nastalog prilikom tog izlaganja te samog popravka nastalog oštećenja. Veliki doprinos razlikama čine i polimorfizmi u genima za popravak DNA. U ovom radu istražili smo povezanost nastalih oštećenja DNA u obliku mikronukleusa (MN), jezgrinih pupova (NB) i nukleoplazmatskih mostova (NPB) s polimorfizmima jednog nukleotida (SNP) u genima za popravak DNK (APE1, hOGG1, XRCC1, XRCC3, XPD, PARP1, MGMT) koji sudjeluju u različitim mehanizmima popravka. Rezultati skupine od 77 medicinskih radnika kronično izloženih niskim dozama ionizirajućeg zračenja uspoređeni su s rezultatima skupine od 70 odgovarajućih kontrola. Izložena skupina imala je značajno veću učestalost MN-a (16,2±10,4 vs. 11.5±9.4; P=0,003), a sama pojavnost oštećenja bila je neovisna o medijatornoj varijabli (kovarijati). Značajno više učestalosti MN nađene su u izloženoj skupini u homozigotnih nositelja divljeg tipa gena hOGG1, XRCC1, PARP1 i MGMT i u heterozigotnih nositelja gena APEX1 i XPD (rs13181) u odnosu na kontrolnu skupinu istoga genotipa. Analiza genskih polimorfizama i citogenetička dozimetrija važna su dopuna osobnom dozimetrijskom nadzoru izloženih radnika

DNA Damage and Glutathione Peroxidase Activity in Liver and Kidney Cells in Wistar Rats Exposed to Terbuthylazine (TERB) for 28 Consecutive Days

The potential of low doses of the chloro-triazine herbicide terbuthylazine to induce DNA damage and impair activity of glutathione peroxidase (GPx) was evaluated in kidney and parenchymal and non-parenchymal liver cells of adult male rats. In a 28-day study, terbuthylazine was applied daily by oral gavage at doses: 0.004, 0.4 and 2.29 mg/kg bw/day. Tail Intensity (T Int) and Tail Length (TL) were used as descriptors of DNA damage. In the kidney, Tail Int was significantly different in all treated groups, while TL was different in 0.4 and 2.29 mg/kg bw/day groups, compared to controls. Significant differences in TL were recorded in parenchymal and non-parenchymal liver cells of all treated groups. Tail Int was significantly different from controls in non-parenchymal liver cells at all applied doses and in parenchymal cells at terbuthylazine doses of 0.004 and 2.29 mg/kg bw/day. A significant increase in GPx activity was observed only in the kidney at doses 0.4 and 2.29 mg/kg bw/day compared to the controls indicating its possible role in the protection of kidney from free radicals. It appears that repeated exposure to low doses of terbuthylazine could cause DNA instability in kidney cells and in parenchymal and non-parenchymal liver cells in rats

Rezultati biomonitoringa radnika profesionalno izloženih olovu u industriji izrade baterija i keramičkih pločica ...

Manufacture of lead-containing products has long been associated with various health risks. To get an insight into the related genotoxic risks, we conducted a biomonitoring study in 50 exposed workers and 48 matched controls using a battery of endpoints that sensitively detect the extent of genome instability in peripheral blood lymphocytes. The levels of primary DNA damage were estimated with the alkaline comet assay, while cytogenetic abnormalities were determined with the cytokinesis-block micronucleus (CBMN) cytome assay. Additionally, CBMN slides of 20 exposed and 16 control participants were subjected to fluorescence in situ hybridisation (FISH), coupled with pancentromeric probes to establish the incidence of centromere-positive micronuclei, nuclear buds, and nucleoplasmic bridges. Blood lead levels (B-Pb) were measured with atomic absorption spectrometry. To further characterise cumulative effects of occupational exposure, we measured erythrocyte protoporphyrin (EP) concentrations and delta-aminolevulinic acid dehydratase (ALAD) activity in blood. We also assessed the influence of serum folate (S-folate) and vitamin B12 (S-B12) on genome stability. Compared to controls, occupationally exposed workers demonstrated significantly higher B-Pb (298.36±162.07 vs 41.58±23.02), MN frequency (18.71±11.06 vs 8.98±7.50), centromere positive MN (C+ MN) (8.15±1.8 vs 3.69±0.47), and centromere negative MN (C- MN) (14.55±1.80 vs 4.56±0.89). Exposed women had significantly higher comet tail intensity (TI) and length (TL) than control women. Furthermore, workers showed a positive correlation between age and nuclear buds and MN, between MN and years of exposure, and between S-B12 levels and TI and ALAD activity, while a negative correlation was found between TI and B-Pb. These findings suggest that occupational settings in the manufacture of lead-containing products pose significant genotoxic risks, which calls for developing more effective work safety programmes, including periodical monitoring of B-Pb and genetic endpoints.Profesionalna izloženost u industriji olova štetno utječe na zdravlje radnika. Ovo je istraživanje provedeno na 50 radnika izloženih olovu te 48 ispitanika kontrolne skupine primjenom testova za procjenu genomske nestabilnosti u limfocitima periferne krvi. Razine primarnoga oštećenja DNA procijenjene su alkalnim komet-testom, a citogenetičke abnormalnosti utvrđene su citohalazin blokiranim mikronukleus-testom (CBMN). Na podskupini od 20 izloženih i 16 kontrolnih ispitanika dodatno je proveden mikronukleus-test u kombinaciji s fluorescencijskom in situ hibridizacijom (MN-FISH). Primjenom pancentromernih sonda istražili smo učestalost mikronukleusa pozitivnih na centromere, nuklearnih pupova I nukleoplazmatskih mostova. Razine olova u krvi (B-Pb) izmjerene su atomskom apsorpcijskom spektrometrijom. Kako bismo utvrdili kumulativne učinke profesionalne izloženosti, izmjerili smo koncentracije eritrocitnoga protoporfirina (EP) i aktivnost dehidrataze delta-aminolevulinske kiseline (ALAD) u krvi. Također smo procijenili utjecaj serumskoga folata (S-folata) i vitamina B12 (S-B12) na stabilnost genoma. U usporedbi s podudarnim kontrolama, profesionalno izloženi radnici imali su značajno višu razinu B-Pb (298,36±162,07 vs. 41,58±23,02), učestalost MN-a (18,71±11,06 vs. 8,98±7,50), mikronukleusa pozitivnih na centromere (C+ MN) (8,15±1,8 vs. 3,69±0,47) i mikronukleusa negativnih na centromere (C- MN) (14,55±1,80 vs. 4,56±0,89). Izložene radnice imale su značajno veći intenzitet (TI) i duljinu (TL) repa u komettestu od ženskih kontrola. Nadalje, u radnika je utvrđena pozitivna korelacija između učestalosti jezgrinih pupova i MN-a s dobi, između MN-a i godina izloženosti te između TI-ja i aktivnosti ALAD-a i razina S-B12. Negativna korelacija utvrđena je između TI-ja i B-Pb. Dobiveni rezultati upućuju na to da profesionalna izloženost olovu predstavlja značajan genotoksični rizik, što zahtijeva razvoj učinkovitijih programa zaštite na radu, uključujući povremeno praćenje B-Pb i genetičkih markera