130 research outputs found
Persistence of micronuclei in human lymphocytes after fractionated irradiation in vitro
The study evaluate relationship between incidence of micronuclei and chromosomal aberrations after fractionated irradiation of human lymphocytes in vitro. Obtained results have shown that incidence of chromosome aberrations aberrations declined faster than micronuclei at all given doses if the time between two irradiationsis longer than 2 hours. The study confirmed that CBMN test is very sensitive assay for estimation of effects of ionizing radiation in the case of fractionated irradiation. This observation could be of interest for radiotherapy, particularly for applying micronucleus test as predictive test for hypersensitivity to ionizing radiation.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200
Positive correlation between micronuclei and necrosis of lymphocytes in medical personnel occupationally exposed to ionizing radiation
BACKGROUND: Current radiation protection standards are based on premise that any radiation dose may result in detrimental health effects. The aim of this study was to evaluate extent of the DNA damages (measured by induction of micronuclei) and interphase cell death in circulating lymphocytes of medical personnel exposed to ionizing radiation. METHODS: Baseline micronuclei were assessed using the cytokinesis-block micronucleus test. Cytotoxicity was analyzed by flow cytometry for human white blood cells to identify cells that displayed apoptosis-associated DNA condensation. Necrotic cells were analyzed simultaneously. All parameters were compared with corresponding controls. RESULTS: A statistically significant difference (t = 4.54, p = 0.002) was found between exposed and control group in the yield of baseline micronuclei. The level of baseline micronuclei correlated positively with necrosis of leucocytes (r=0.09, p=0.68 in exposed group, r=0.02, p=0.97 in controls). An inverse correlation between baseline micronuclei and apoptosis was noted in both groups of examinees (r = -0.26, p = 0.27 in exposed group, r = -0.09, p=0.80 in controls). The data obtained also suggested an inverse correlation between necrosis and apoptosis (r = -0.37, p = 0.11 in exposed group, r = -0.89, p = 0.001 in controls). CONCLUSION: Flow cytometry being a rapid, fast, and accurate method is strongly recommended in evaluation of radiation injuries. The integration of apoptosis and necrosis into micronucleus assay could be very important in the assessment of cumulative effects of ionizing radiation in occupationally exposed medical personnel
Radioprotective properties of nutraceutical Gonebazol: In vivo study
BACKGROUND: In vitro investigation of radioprotective properties of novel nutraceutical Gonebazol (Biofarm, Belgrade) has displayed its remarkable potential to reduce chromosomal aberrations and micronuclei induced by x rays. The goal of this study was to evaluate its protective properties in vivo. For this purpose, a group of medical staff performing invasive radiological diagnostics, that was identified to carry dicentrics in their lymphocytes, was selected for further monitoring. They consumed this nutraceutical for 3 weeks, 2 x 10 g per day (2 x 2 teaspoons dissolved in a glass of water). METHODS: Hematological parameters, chromosomal aberrations and micronucleus frequency were examined at the beginning of monitoring, on day 10 and 21 of the treatment. RESULTS: In the course of three weeks the incidence of chromosomal aberrations and micronuclei was significantly reduced (50%-80%), absolute number of granulocytes was lowered whereas the number of monocytes significantly was enhanced. This study has revealed that nutraceutic posses immunomodulatory properties seen as an improving monocyte-macrophage activity, which inversely correlates with incidence of lymphocyte micronuclei (r=0.75, p<0.05). CONCLUSION: Observed finding could be of particular importance in reducing cumulative effects of ionizing radiation in radiosensitive tissues and in preventing adverse health effects. No side effects were evidenced. Mechanisms of its immunomodulatory effects should be further examined
Lomljivost telomera u bolniÄkih radnika profesionalno izloženih niskim dozama ionizirajuÄega zraÄenja
AbstractBioloÅ”ki uÄinci ionizirajuÄega zraÄenja (IZ) pripisuju se oÅ”teÄenjima DNA i indirektnim uÄincima kroz poveÄanu proizvodnju reaktivnih vrsta kisika. Iako se telomere rabe kao pokazatelji radioosjetljivosti, o njihovu ponaÅ”anju kao odgovoru na ionizirajuÄe zraÄenje u uvjetima profesionalne izloženosti i dalje se raspravlja. U ovom radu željeli smo istražiti duljinu i strukturu telomera u bolniÄkih radnika koji su profesionalno izloženi ionizirajuÄem zraÄenju te povezati te nalaze s oksidacijskim biomolekulama i kromosomskim aberacijama. Uzorci krvi izloženih ispitanika i zdravih kontrola uzeti su za analizu tijekom rutinskoga godiÅ”njeg zdravstvenog pregleda. Osim kromosomskih aberacija, u uzorcima plazme izmjereni su i parametri oksidacijskoga stresa [prooksidacijska/antioksidacijska ravnoteža (PAB), lipidna peroksidacija i 8-okso-dG], a procjena duljine i strukture telomera provedena je metodom Q-FISH na metafaznim kromosomima. Analiza kromosomskih aberacija pokazala je da od 34 ispitanika njih 14 ima kromosomske aberacije (skupina 1), a 20 nije imalo aberacije (skupina 2). Nije bilo znaÄajne razlike u spolu ili dobi ni u duljini telomera izmeÄu skupina. MeÄutim, incidencija lomljivih telomera bila je znaÄajno veÄa u objema skupinama ispitanika izloženih IZ-u u usporedbi s kontrolnim ispitanicima. Produkti peroksidacije lipida i 8-okso-dG takoÄer su bili znaÄajno viÅ”i u objema skupinama. UÄestalost lomljivih telomera u pozitivnoj je korelaciji (statistiÄki znaÄajna) s razinama 8-okso-dG
The radioprotective properties of polyphenols on human lymphocytes
The aim of this study was to evaluate radioprotective properties of medical plants Gentianella austriaca and Gentianella dinarica. For this purpose human lymphocytes were irradiated using 60Co Ī³ rays and treated with different fractions of plant extracts, afterwards micronuclei (MN) and malondialdehyde (MDA) were measured. Polyphenols, fractions isolated from those plants have shown the protective effects, seen as significantly reduced incidence of micronuclei which was followed with reduced level of malondialdehyde. The results obtained in this study indicate that polyphenols isolated from Gentianella austriaca and Gentianella dinarica posses radioprotective properties possibly trough reduction of the lipid peroxidation.Physical chemistry 2004 : 7th international conference on fundamental and applied aspects of physical chemistry; Belgrade (Serbia); 21-23 September 200
Optimizacija metode za izolaciju epitelnih stanica iz nežljezdanog dijela želuca Å”takora za protoÄnu citometriju
Traditional methods in cell proliferation studies are based on immunohistochemical detection of proliferating cells in the target tissue. Since they are time consuming, optimization of novel, more efficient methods is important for large scale proliferation studies. In this study, we aimed to optimize the isolation of single epithelial rat forestomach cells for flow cytometry. As a marker of cellular proliferation we used the Ki-67 antibody to detect this nuclear protein expressed in proliferating cells. We also performed immunohistochemical detection of Ki-67 positive cells and propidium iodide staining to validate the results. 3-tert- butyl -4-hydroxyanisole was used as the positive control to ensure cellular proliferation. The results showed that isolation of epithelial cells with collagenase, trypsin and cell strainer ensures great cell viability (>95%) and the purity of the samples. Flow cytometry and immunostaining with the Ki-67 antibody indicated that 3-tert- butyl-4-hydroxyanisole treatment leads to a significant increase in proliferation. A significant positive correlation was observed between the results obtained by immunohistochemistry and flow cytometry, but the flow cytometric data had a smaller measurement error, suggesting the equal sensitivity and greater accuracy of this method. Propidium iodide staining showed that the percentage of cells in the G2+S phase of the cell cycle correlated positively with the percentage of Ki-67 positive cells assessed by flow cytometry, indicating that Ki-67 positive cells reflect an active dividing cell pool. We conclude that the isolation of forestomach epithelial cells described is a simple and reliable method for obtaining viable cells for use in flow cytometry. Compared to immunohistochemistry, flow cytometric detection of the Ki-67 antigen is equally sensitive, but much faster and provides more accurate results.Tradicionalne metode u ispitivanju staniÄne proliferacije temelje se na imunohistokemijskom otkrivanju proliferacijskih stanica u ciljanom tkivu. Kako su dugotrajne, optimizacija novih i uÄinkovitijih metoda važna je za velika istraživanja o proliferaciji. U ovom smo radu željeli optimizirati izolaciju epitelnih stanica prednjeg želuca Å”takora za protoÄnu citometriju. Kao marker staniÄne proliferacije koristili smo Ki-67 protutijelo za otkrivanje ovoga nuklearnog proteina izraženog u proliferacijskim stanicama. TakoÄer smo uÄinili imunohistokemijsku detekciju Ki- 67 pozitivnih stanica i bojenje propidij-jodidom kako bismo potvrdili rezultate. Butil-hidroksianizol koriÅ”ten je kao pozitivna kontrola da se osigura staniÄna proliferacija. Rezultati su pokazali da izolacija epitelnih stanica s kolagenazom, tripsinom i staniÄnim cjedilom osigurava veliku vijabilnost stanica (> 95 %) i ÄistoÄu uzoraka. ProtoÄna citometrija i Ki-67 bojenje pokazali su da tretman butil-hidroksianizolom dovodi do znakovitog porasta proliferacije. PrimijeÄena je znakovita pozitivna korelacija izmeÄu rezultata dobivenih imunohistokemijom i protoÄnom citometrijom, dok su protoÄni citometrijski podaci imali manju pogreÅ”ku mjerenja, Å”to upuÄuje na jednaku osjetljivost i veÄu toÄnost ove metode. Bojenje propidij-jodidom pokazalo je da postotak stanica u G2+S fazi staniÄnog ciklusa pozitivno korelira s postotkom Ki-67 pozitivnih stanica procijenjenih protoÄnom citometrijom, Å”to upuÄuje na to da Ki-67 oslikava stanice u aktivnoj diobi. ZakljuÄujemo da je opisana izolacija epitelnih stanica prednjeg želuca Å”takora jednostavna i pouzdana metoda za dobivanje održivih stanica za upotrebu u protoÄnoj citometriji. U usporedbi s imunohistokemijom, protoÄna citometrijska detekcija antigena Ki-67 jednako je osjetljiva, ali mnogo brža i daje toÄnije rezultate
Modulation of the ribavirin induced cytotoxicity in harvested human lymphocytes in vitro
The present investigation was undertaken to evaluate effect of vitamin B12 on ribavi- rin induced cytotoxicity in phytohemaglutinin-stimulated human lymphocytes. Blood samples, obtained from healthy volunteers (males, aged 31 years, non-smokers) are used for examination. Blood cells were treated with increasing doses of ribavirin: 0.05, 0.17, 0.32, 0.47 and 0.65Āµmol/ml at three different incubation times: 2, 4 and 17 hours. Duplicate ribavirin treated cultures were supplemented with 50 Āµl of B12 during the drug treatment. Supplementation with B12 lowers the MN frequency and slightly recovers the proliferation potential of treated cells in each treatment period of time except for the highest concentration and the longest treatment. Presence of ribavirin during entire S phase of the cell cycle strongly blocks cell cycle progression. This study have shown that B12 posses unique beneficial effects in reducing the toxic effects of ribavirin. Mechanism of beneficial effects of ribavirin should be examined further
BioloÅ”ki uÄinciI Echinacea purpurea na krvne stanice ljudi
The aim of this study was to investigate radioprotective properties of Echinacea purpurea tablets in vivo. We analysed lymphocyte chromosome aberrations (CA), micronuclei (MN), apoptosis of leukocytes and haematological parameters in a group of radiation workers who were identified as carrying dicentric chromosomes in their lymphocytes. All radiation workers were taking two 275 mg Echinacea tablets b.i.d., according to a pharmacistās recommendation. All parameters were analysed before and after the two-week treatment. At the end of the treatment lymphocyte CA frequency dropped significantly, and the number of apoptotic cells increased. The inverse lymphocyte-to-granulocyte ratio at the beginning of the study changed to normal at its end. In conclusion, biological effects observed after administration of Echinacea purpurea preparation suggest that it may be beneficial for the prevention of adverse health effects in workers exposed to ionising radiation.Cilj ovog rada je utvrÄivanje radioprotektivnih svojstava Echinacea purpurea (āEhinaceaā, Strong Nature, Srbija) in vivo. Analizirani su kromosomske aberacije, mikronukleusi, apoptoza leukocita i hematoloÅ”ki parametri u skupini ispitanika profesionalno izloženih ionizirajuÄem zraÄenju u Äijim je limfocitima utvrÄena prisutnost dicentriÄnih kromosoma. Sve osobe profesionalno izložene ionizirajuÄem zraÄenju su uzimale 4 āEchinaceaā tablete na dan, prema preporuÄenoj ljekarniÄkoj dozi. Svi parametri su analizirani na poÄetku i nakon dva tjedna tretmana. Na kraju studije uÄestalost kromosomskih aberacija u limfocitima znaÄajno je smanjena, dok je apoptotski potencijal leukocita poveÄan. Omjer limfocita i granulocita utvrÄen na poÄetku studije nakon dva tjedna je dostigao normalne vrijednosti. UoÄena svojstva Echinacea purpurea mogu biti važna u prevenciji i ublažavanju uÄinaka Å”tetnih za zdravlje
Genotoxicity of the poly-D,L-lactide microparticles on the human lymphocytes
Particles generated of biodegradable material are extensively investigated as carriers
for sustained drug delivery. Studies have been mainly focused on the monitoring of the drug
release and of the rate of the particle degradation. However, the influence of the carrier particles
on the human immune cells was only rarely addressed. In this work, the influence of the
microparticles made of poly-D,L-lactide (PDLLA) on the function of human lymphocytes in a
three-day culture was investigated. PDLLA microparticles have been prepared by a modified
precipitation method and human lymphocytes were isolated from the blood of healthy volunteers
by a Ficoll ā density gradient centrifugation. Lymphocyte proliferation test and the cytochalasin
B micronucleus test were used to assess the PDLLA particle effect on the lymphocytes. Results
showed that PDLLA particles did not influence on the proliferation of the human lymphocytes.
On the other hand, changes in the nuclei form, as well as nucleus buddings were observed.
Moreover, the appearance of micronuclei could be detected. All together, these results might
imply genotoxicity of the PDLLA particles, or some of the chemicals used for the particle
preparation/stabilization on the human lymphocytes
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