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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Avaliação in vitro da cisplatina, em linfócitos de pacientes com melanoma cutâneo, por meio de testes citogenéticos / In vitro assessment of cisplatin, in lymphocytes of patients with cutaneous melanoma, using cytogenetic tests

Fernanda Shimabukuro 23 July 2010 (has links)
O melanoma cutâneo maligno é uma lesão neoplásica originada nos melanócitos epidérmicos, sendo altamente invasiva e agressiva, com elevada taxa de mortalidade, cuja incidência vem aumentando nos últimos anos. O tratamento do melanoma é cirúrgico e os pacientes com metástase podem receber quimioterapia com cisplatina que ao formarem adutos com o DNA alteram o processo de replicação da célula cancerosa. Sugere-se que os sistemas de reparo do DNA tenham um papel importante na etiologia do melanoma (reparo deficiente) e no tratamento do mesmo (eficiente eliminação dos adutos). A identificação prévia da resposta dos pacientes com melanoma ao tratamento com cisplatina pode ser um indicador biológico importante na clínica oncológica. O presente trabalho teve como objetivo, a partir de linfócitos de sangue periférico de pacientes com melanoma e de controles, avaliar o dano no DNA antes e após a adição, in vitro, de cisplatina (10?M, 100?M e 250?M), além de estimar a capacidade de reparo do DNA, após a retirada da droga (1h, 2,5h e 5h). Foram utilizados os testes do micronúcleo (MN - dano basal) e do Cometa (dano basal, ação da cisplatina e reparo do DNA). A análise citogenética foi possível em 20 pacientes com melanoma (10 homens e 10 mulheres, média de 50,6 ± 5,9 anos) e 19 controles (9 homens e 10 mulheres, média de 49,9 ± 5,5 anos) que também responderam a um questionário sobre hábitos e tipos de exposição a fatores de risco ao melanoma. A frequência do dano basal pelo teste do MN e do Cometa em linfócitos de pacientes (MN = 1,2 ± 1,2 e Cometa = 59,3 ± 62,5) foi praticamente o dobro da observada nos controles (MN = 0,6 ± 1,0 e Cometa = 35,3 ± 18,6) embora a diferença entre os grupos, em ambos os testes, não tenha sido considerada estatisticamente significante (p=0,23 e p=0,85, respectivamente). O tratamento in vitro com cisplatina, em comparação com o dano basal, aumentou a frequência de Cometas nas três concentrações estudadas (10?M, 100?M e 250?M) tanto para os pacientes (65,50 ± 50,06, 72,74 ± 50,89 e 77,26 ± 44,16) quanto para os controles (66,53 ± 49,85, 66,53 ± 26,33 e 81,74 ± 43,12) diferença esta considerada significante somente para o grupo controle, nas três concentrações avaliadas (p=0,0175, p=0,0002, e p=0,0002, respectivamente). Quanto aos diferentes tempos de reparo (1h, 2,5h e 5h), após a retirada de cisplatina nas diferentes concentrações estudadas, verificou-se aumento na frequência média de Cometas tanto para os pacientes com melanoma (93,88 ± 33,7, 101,75 ± 35,7 e 99,31 ± 32,30) quanto para os controles (92,45 ± 38,4, 100,82± 38,8 e 100,81± 31,7), diferença que foi estatisticamente significante quando comparada ao dano basal observado nos pacientes (p<0,001) e nos controles (p<0,001). Resultados semelhantes foram observados quando comparados em conjunto os escores dos tempos de reparo com o escore obtido após tratamento com cisplatina nos pacientes (71,09 ± 48,2; p<=0,005) e nos controles (71,59 ± 40,5; p<=0,005). Os resultados obtidos parecem indicar um padrão de resposta semelhante em relação à cisplatina e ao reparo do DNA nos dois grupos de indivíduos avaliados. O período de incubação das células, após a retirada da cisplatina, bem como o número de indivíduos avaliados podem ter influenciado nos resultados obtidos. Por outro lado, a resposta observada nos linfócitos in vitro, pode não ser representativa do efeito in vivo da célula tumoral. Entretanto, a identificação de marcadores de resposta a tratamentos com quimioterápicos, a partir de linfócitos de sangue periférico pode ser uma estratégia de pesquisa importante na prática clínica, inclusive para o melanoma. / Cutaneous melanoma is a malignant tumor originated from epidermal melanocytes, highly invasive and aggressive, with high mortality, and incidence that has been increasing over the years. The treatment for melanoma is surgery and patients with metastasis may receive chemotherapy with cisplatin, that results in DNA adducts that alters the replication process in cancer cells. It is suggested that the DNA repair systems have an important role in the etiology of melanoma (risk due to deficient repair) and treatment efficiency (removal of DNA adducts can decrease the treatment results). The prior identification of the response of melanoma patients to treatment with cisplatin may be an important biological marker in clinical oncology. The aim of this study was to assess, in peripheral blood lymphocytes from melanoma patients and controls, the DNA damage before and after the addition of cisplatin (10?M, 100?M and 250?M), in vitro, and estimate the capacity of DNA repair after drug removal (1h, 2.5h and 5h). The micronucleus test (MN - basal DNA damage) and the Comet assay (basal DNA damage, action of cisplatin and DNA repair) were used for the evaluation. Cytogenetic analysis was performed in 20 melanoma patients (10 men and 10 women, average age 50.6 ± 5.9 years old) and 19 controls (9 men and 10 women, average age 49.9 ± 5.5 years old) who also answered a questionnaire on habits and types of exposure to risk factors for melanoma. The frequency of basal DNA damage by the MN test and the Comet assay in lymphocytes from patients (MN = 1.2 ± 1.2 and Comet = 59.3 ± 62.5) was nearly twice the observed in controls (MN = 0, 6 ± 1.0 and Comet = 35.3 ± 18.6), although the difference between the groups in both tests was not considered statistically significant (p = 0.23 and p = 0.85, respectively). The in vitro treatment with cisplatin, compared with the basal DNA damage, increased the frequency of Comets in the three studied concentrations (10?M, 100?M and 250?M) for patients (65.50 ± 50.06, 72.74 ± 50.89 and 77.26 ± 44.16) and for the controls (66.53 ± 49.85, 66.53 ± 26.33 and 81.74 ± 43.12) and the difference was statistically significant only for the control group, for all cisplatin concentrations (p = 0.0175, p = 0.0002 and p = 0.0002, respectively). Considering the different repair times (1h, 2.5h and 5h), after removal of cisplatin at different concentrations, there was an increase in the mean frequency of Comets for both melanoma patients (93.88 ± 33.7, 101.75 ± 35.7 and 99.31 ± 32.30) and for the controls (92.45 ± 38.4, 100.82 ± 38.8 and 100.81 ± 31.7), and the difference was statistically significant when the repair Comet score was compared to the basal DNA damage observed in patients (p <0.001) and controls (p <0.001). Similar results were observed when the Comet scores of repair times were compared to the Comet scores obtained after treatment with cisplatin in patients (71.09 ± 48.2, p <= 0.005) and controls (71.59 ± 40.5, p <= 0.005). The results seem to indicate a similar pattern of response to cisplatin and DNA repair in both groups of subjects evaluated. The period of incubation of the cells after cisplatin removal and the number of individuals studied may have influenced the results. The lymphocytes\' response, in vitro, to cisplatin may not be representative of the in vivo effect of tumor cell. However, the identification of markers of response to treatment with chemotherapy from peripheral blood lymphocytes may be an important research strategy in clinical practice, including melanoma.
92

Efeito do tamanho das nanopartículas de prata na indução de danos citotóxicos e genotóxicos nas linhagens celulares CHO-K1 e CHO-XRS5 / Effect of silver nanoparticles size in the induction of cytotoxic and genotoxic damage in CHO-K1 and CHO-XRS5 cell lines

Tiago Alves Jorge de Souza 27 June 2013 (has links)
Devido às características especiais as nanopartículas (10-9m) estão sendo utilizadas em uma ampla gama de produtos, porém é conhecido que a utilização dessas partículas podem causar efeitos biológicos adversos, aumentando a preocupação em relação à saúde e ao meio ambiente. Recentemente, as nanopartículas de prata (AgNPs) têm sido alvo de estudos genotóxicos e citotóxicos, sendo que ainda não existe um consenso acerca da relação entre tamanho e toxicidade dessas partículas. Assim, este trabalho avaliou a citotoxicidade e a genotoxicidade das AgNPs de 10 e 100 nm nas linhagens celulares CHO-K1 e CHO-XRS5, por meio do Ensaios de Viabilidade Celular, Sobrevivência Clonogênica, Teste do Micronúcleo, o Ensaio Cometa e Cinética do Ciclo Celular por Citometria de Fluxo. Em todos os ensaios, as células foram expostas por 24 h à diferentes concentrações de AgNPs (0,025 a 5,0 g/ml) e, as células não tratadas foram utilizadas como controle negativo. A concentração de 5,0 g/ml foi citotóxica nos ensaios de Viabilidade Celular e Sobrevivência Clonogênica, sendo excluída dos ensaios de genotoxicidade. De maneira geral, as células CHO-XRS5 apresentaram menor viabilidade e maior quantidade de danos no DNA do que as células CHO-K1. As AgNPs de 10 nm causaram maiores níveis de danos no DNA em ambas as linhagens e um aumento de células em subG1 logo após o tratamento na linhagem CHO-K1. Entretanto, no tempos 24 e 72 h após o tratamento foi verificada a maior toxicidade (células em subG1) das AgNPs de 100 nm quando comparadas com suas homólogas menores (10 nm). Assim, foi observado que as AgNPs de 10 nm apresentam efeito tóxico a curto prazo similar ou maior do que a mesma concentração de partículas de 100 nm. No entanto, os efeitos genotóxicos e citotóxicos de longo prazo das AgNPs de 100 nm foram maiores do que os da partículas de 10 nm para ambas as linhagens celulares, comprovando que a exposição às AgNPs maiores (100 nm) pode causar mais efeitos biológicos adversos do que suas homólogas menores (10 nm). / Due to their particular characteristics, nanoparticles (10-9m) are being used in a range of products. However, these particles can cause adverse biological effects and because of that, there is a great concern about the health and environmental risks related to the use of these particles. Recently, silver nanoparticles (AgNPs) have been used in a variety of cytotoxicity and genotoxicity studies, but there are still controversies regarding the association between the size and the toxicity of these particles. Thus, in this study, we aimed to evaluate the cytotoxicity and genotoxicity of AgNPS (10 and 100 nm) in two different cell lines, CHO-K1 and CHO-XRS5, by performing Cell Viability assay (XTT), Clonogenic assay, Micronucleus test, Comet assay, as well as by investigating the Cell Cycle kinetics using the flow cytometry. For all the different assays, the cell cultures were exposed for 24 hours to different concentrations of AgNPs (0.025 to 5.0 g/ml) and the untreated cells were used as the negative controls. Since results from the Viability and Clonogenic assays indicated that the concentration of 5.0 g/ml was cytotoxic for both cell lines, this concentration was not included in the genotoxic assays. Our results indicated that the CHO-XRS5 cells presented a lower viability and higher levels of DNA damage compared to the CHO-K1 cells. The 10 nm-AgNPs induced greater levels of DNA damage than the 100 nm-particles in both cell lines and the former also led to a subG1 arrest soon after the treatment only in the CHO-K1 cell line. In contrast, results from all the other assays indicated that greater levels of toxicity were induced by the 100 nm-AgNPs when compared to the 10 nm-particles, both 24 and 72 h after the treatment. Thus, at the same concentration, the short-term effects of the 10 nm-AgNPs were equal to or more toxic than those of the 100 nm-particles. Nevertheless, both long-term genotoxicity and cytotoxicity induced by the 100 nm-AgNPs were greater than those induced by the 10 nm-particles for both cell lines, which suggests that the exposure to greater size particles (100 nm) can cause more adverse biological effects than the exposure to the smaller particles(10 nm).
93

Vliv anestézie na míru oxidativního poškození DNA / The influence of anesthesia on the degree of DNA oxidative damage

Zubáňová, Veronika January 2017 (has links)
Background: Oxidative damage is one of the most frequent types of cell components damage leading to oxidation of lipids, proteins and the molecule of DNA. As a consequence, there is a higher occurrence of several pathologies such as atherosclerosis, neurodegenerative diseases, cancer; or diabetes. In our study, influence of whole body anesthesia during minor surgery on the level of DNA damage was examined using comet assay technique. Methods: The basic principle of this method is fixing the cells (lymphocytes) in agarose, their lysis for the removal of membranes, incubation with the specific enzymes and electrophoresis of the released cell nuclei. During the electrophoresis, free low-molecular weight and negatively charged fragments of DNA move towards anode which causes the formation of the typical comet cell shape. Finally, the gels are stained by ethidium bromide (DNA intercalating dye) and visualized. Results: We have observed single strand breakages (SSBs) and, with the use of modified assay using specific enzymes for detection of specific lesions, also oxidized purines and pyrimidines. The extent of DNA damage as determined by the intensity of the tail of the comet was quantified using LUCIA Comet Assay (Laboratory Imaging, Czech Republic) software for image analysis. The results were used...
94

Vliv spinální anestezie na míru poškození DNA / The influence of spinal anesthesia on the degree of DNA damage

Koščáková, Mária January 2018 (has links)
Background: The human organism is exposed daily to many endogenous and exogenous substances that are the source of oxidative damage. Cell structures, including DNA (deoxyribonucleic acid) in the nucleus are damaged due to high concentrations of these substances and accumulation of oxidative stress in cells. The predominance of these damaging processes may later be responsible for human diseases such as cancer, neurodegenerative diseases or heart failure. In our study, we observed oxidative damage at the DNA level due to spinal anesthesia. Methods: Sample processing was performed by comet analysis. The principle consists in fixation of cells (lymphocytes) in the agarose gel, lysis of cell structures for nucleotide release, incubation with specific enzymes and exposure to electrophoresis. Damaged, negatively charged parts of the DNA in the electric field are directed to the positive charged anode, creating a typical comet shape. For visualization, the gels were stained with ethidium bromide (DNA intercalating dye). Results: We have quantified single-strand breaks, oxidized purines and pyrimidines (use of enzymes to detect specific damages). The results are reported in percentage of DNA in the comet's tail. The principle is to compare the intensity of the comet's tail with the total comet intensity....
95

In vitro-Exposition von Glycerin als Bestandteil des Shisha-Tabaks an humanen Nasenschleimhautzellen und Lymphozyten / In vitro exposure of glycerol as an ingredient of shisha tobacco to human nasal mucosa cells and lymphocytes

Uebelacker, Lukas January 2019 (has links) (PDF)
Shisha-Tabak benötigt im Vergleich zur Zigarette höhere Konzentrationen des Feuchthaltemittels Glycerin. Seit Mai 2016 ist die bis dahin gültige Limitierung von Feuchthaltemitteln in Tabak auf 5 % aufgehoben. Derzeit ist das toxikologische Profil des Glycerins jedoch noch nicht hinreichend erforscht. Ziel dieser Arbeit war es, Glycerin auf mögliche zyto- und genotoxische Effekte zu untersuchen, um so das Gefährdungspotenzial durch Glycerin im Shisha-Tabak zu beurteilen und die tabakkontrollpolitische Situation in Deutschland zu diskutieren. Dafür wurden Lymphozyten sowie Nasenschleimhautzellen von 10 Patienten für eine Stunde Glycerin (0,001 mol/l bis 6,0 mol/l) exponiert. Durch den Trypanblau-Ausschlusstest wurden die Zellen auf Zytotoxizität, mittels Einzelzellgelelektrophorese (Comet Assay) und Mikrokern-Test auf Genotoxizität untersucht. Im Trypanblau-Ausschlusstest traten bei Lymphozyten sowie nasalen Mukosazellen signifikante Vitalitätsabfälle ab Glycerin-Konzentrationen von 1,0 mol/l auf. Im Comet Assay konnten für beide Zellgruppen signifikante Unterschiede des Olive Tail Moments (OTM) ab 1,0 mol/l nachgewiesen werden. Beim Mikrokern-Test zeigten sich keine signifikanten Zunahmen der Mikrokern-Anzahl. Es konnten zyto- und genotoxische Effekte ab Konzentrationen von 1,0 mol/l nachgewiesen werden. Dies überschreitet die reale Glycerin-Belastung im Hauptstromrauch der Shisha jedoch deutlich. Dennoch handelt es sich bei Genotoxizität um ein stochastisches Risiko. Ebenso sind toxische Effekte, beispielsweise durch Erhitzung, bereits bei geringeren Konzentrationen denkbar. Für eine umfangreichere Beurteilung von Feuchthaltemitteln im Shisha-Tabak sind weitere Untersuchungen indiziert. Darüber hinaus besteht enormer Handlungsbedarf zur weiteren Einführung tabakkontrollpolitischer Maßnahmen in Deutschland. / Shisha tobacco has a higher amount of glycerol than cigarette tobacco. Moreover, new legislation in Germany cancels the old limitation of humectants in shisha tobacco. Although higher amounts of glycerol in tobacco are expected, the knowledge of the toxicological profile of glycerol regarding human cells is incomplete. Aim of the study was to test glycerol for cytotoxic and genotoxic effects and to discuss the risk of humectants in shisha tobacco and the situation of German tobacco control. Lymphocytes and nasal mucosa cells of 10 patients were exposed to different glycerol levels (0.001 mol/l to 6.0 mol/l). Cytotoxic effects were examined by trypan blue exclusion test, genotoxic effects by comet assay and micronucleus test. The trypan blue exclusion test revealed significant cytotoxic effects on lymphocytes and nasal mucosa cells for glycerol concentrations of 1.0 mol/l and higher. In the comet assay a significant DNA damage could be shown for glycerol levels of 1.0 mol/l and higher. No significant micronucleus formation was monitored. While the geno- and cytotoxicity were seen in concentrations of glycerol clearly exceeding the concentrations in main stream smoke of shishas, genotoxicity is a stochastic risk occurring even at subtoxic levels. Furthermore, toxicity in lower levels could result from tobacco combustion or interactions with other smoke components. For an extensive evaluation of the risks of humectants in shisha tobacco further studies are needed. In addition, there is an enormous need for introducing further measures of tobacco control policy in Germany.
96

In vitro chemically-induced DNA damage in cancer patients and healthy individuals. The effect of genotoxic compounds in cells from polyposis coli, colon cancer patients and healthy individuals.

Kurzawa-Zegota, Malgorzata January 2011 (has links)
In the present study DNA damage was measured in peripheral blood lymphocytes from polyposis coli and colorectal cancer patients, treated with different dietary and environmental compounds and compared with lymphocytes from healthy individuals. In addition, confounding factors such as age, gender, alcohol intake and smoking habits were taken into consideration. The assays used in this study included the Comet assay, the Micronucleus assay, the Micronucleus ¿ FISH assay and the sister chromatid exchange assay. The food mutagens, PhIP and IQ, as well as titanium dioxide nanoparticles (TiO2 NPs) induced a dose dependent increase in the DNA damage and chromosomal abnormalities in all tested groups regardless of confounding factors. Prior to experiments physicochemical characterisation of nanoparticles was conducted. In the presence of the flavonoids, quercetin and rutin that were acting in an antioxidant manner, the DNA damage resulting from the highest doses of food mutagens was significantly reduced. Thus, dietary supplementation with flavonoid-rich vegetables and fruits may prove very effective in protection against oxidative stress. The polyposis coli and colon cancer patients were more susceptible to food mutagens, PhIP and IQ, as well as TiO2 NPs, and in the majority of cases had a higher level of DNA damage in the Comet assay and higher cytogenetic damage in the Micronucleus assay. In the final project, twelve frequently encountered (NewGeneris) chemical compounds were evaluated to establish their damaging potential in lymphocytes and spermatozoa from healthy donors. The highest damage was produced by DNA reactive aldehydes, food mutagens and benzo[a]pyrene when assessed with the neutral and alkaline Comet assay with and without metabolic activation. / EU NewGeneris Programme and United Kingdom - India Education and Research Initiative (UKIERI)
97

In vitro studies on genotoxicity and gene expression in spermatogenic cells: mechanisms and assay development

Habas, Khaled S.A. January 2015 (has links)
Spermatogenesis is a complex process of male germ cell development from diploid spermatogonia to haploid fertile spermatozoa. Apoptosis plays a vital role in limiting cell numbers and eliminating defective germ cells. This requires novel gene products, and precise and well-coordinated programmes of gene expression. It is therefore possible that a disruption of transcription factor function would significantly impact germ cell development. The present work was undertaken to use Staput separation followed by culture of purified germ cells of rodent testis since mammalian spermatogenesis cannot yet be recreated in vitro. Specificity of separation was assessed using immunocytochemistry to identify spermatogonia, spermatocytes and spermatids. The genotoxins H2O2, doxorubicin, N-ethyl-N-nitrosourea, N-methyl-N-nitrosourea, 6-mercaptopurine, 5-bromodeoxyuridine, methyl methanesulphonate and ethyl methanesulphonate were investigated. Cells were cultured and treated with different concentrations for each agent. DNA damage and apoptosis were measured by Comet and TUNEL assay respectively. Up-regulation of expression of the transcription factors Tbpl1, FHL5 and Gtf2a1l that are important post-meiotically, were examined using RT- PCR and qPCR. Protein production was evaluated using Western blotting. Tbpl1, FHL5 and Gtf2a1l were cloned in-frame into the inducible expression vector pET/100-TOPO. The recombinant clones were induced and successful expression of the proteins in E. coli was confirmed by SDS-PAGE and Western blotting. The recombinant clones obtained were used to demonstrate genotoxin induced impairment of gene expression. Thus, Staput-isolated rodent testicular germ cells seem to be a suitable model to study genotoxicity in vitro yielding result comparable to those reported in vivo. Furthermore, the work shows that genotoxins can impair gene expression.
98

Genoprotective effect of aspirin and ibuprofen in human lymphocyte cells. Effect of nano and bulk forms of aspirin and ibuprofen on lymphocytes from breast cancer patients compared with those from healthy females

Dandah, Osama M.M. January 2017 (has links)
ABSTRACT: Various recent studies have suggested that regular intake of some non-steroidal anti-inflammatory drugs (NSAIDs) have a preventative effect against several types of tumours including breast cancer. The term nanotechnology refers to technology in which one-billionth of a meter is used as a scale for chemical particle size. This work aims to study the effect of both ibuprofen and aspirin on DNA damage using peripheral blood lymphocytes from breast cancer patients and comparing the results with those from healthy females as a control using the Comet and micronucleus assays. Western blot analysis (WBA) was used to investigate the effect of these drugs on XRCC3 and p53 proteins, whereas QPCR was to evaluate this effect on p53, cox1 and cox2 genes. Two hundred fifty ng/ml of ibuprofen (NP and bulk) and 500 ng/ml of aspirin (NP and bulk) were used to treat the lymphocytes. Both aspirin and ibuprofen caused a reduction in DNA damage and micronucleus formation. Aspirin, both forms, showed a reduction in DNA damage in the Comet and micronucleus assays. Ibuprofen both forms, by contrast, showed a statistically significant reduction in micronucleus frequency in the micronucleus assay, while its preventative effect with the Comet assay was weak or insignificant. NPs of both agents were more effective than bulk sizes. Using the Comet repair assay, aspirin and ibuprofen nano form catalysed DNA repair to a greater extent than their bulk forms. Also, both sizes showed better repair with NSAIDs compared to samples repaired without NSAIDs. In WBA aspirin increased the expression of XRCC3 protein in healthy cells. However, both NSAIDs decreased that expression in cells from BC patients. Furthermore, aspirin increased p53 expression in BC patients lymphocytes. With the QPCR method, results of both aspirin forms increased the expression of the p53 gene in BC patient cells statistically significantly. Both drugs reduced cox1 expression in healthy volunteers and cancer patients lymphocytes. Moreover, cox2 reduction was only in lymphocytes from BC patients. The results of this work are consistent with the view that NSAIDs, particularly aspirin and ibuprofen, could have a promising role in cancer treatment including breast cancer. / Various recent studies have suggested that regular intake of some non-steroidal anti-inflammatory drugs (NSAIDs) have a preventative effect against several types of tumours including breast cancer. The term nanotechnology refers to technology in which one-billionth of a meter is used as a scale for chemical particle size. This work aims to study the effect of both ibuprofen and aspirin on DNA damage using peripheral blood lymphocytes from breast cancer patients and comparing the results with those from healthy females as a control using the Comet and micronucleus assays. Western blot analysis (WBA) was used to investigate the effect of these drugs on XRCC3 and p53 proteins, whereas QPCR was to evaluate this effect on p53, cox1 and cox2 genes. Two hundred fifty ng/ml of ibuprofen (NP and bulk) and 500 ng/ml of aspirin (NP and bulk) were used to treat the lymphocytes. Both aspirin and ibuprofen caused a reduction in DNA damage and micronucleus formation. Aspirin, both forms, showed a reduction in DNA damage in the Comet and micronucleus assays. Ibuprofen both forms, by contrast, showed a statistically significant reduction in micronucleus frequency in the micronucleus assay, while its preventative effect with the Comet assay was weak or insignificant. NPs of both agents were more effective than bulk sizes. Using the Comet repair assay, aspirin and ibuprofen nano form catalysed DNA repair to a greater extent than their bulk forms. Also, both sizes showed better repair with NSAIDs compared to samples repaired without NSAIDs. In WBA aspirin increased the expression of XRCC3 protein in healthy cells. However, both NSAIDs decreased that expression in cells from BC patients. Furthermore, aspirin increased p53 expression in BC patients lymphocytes. With the QPCR method, results of both aspirin forms increased the expression of the p53 gene in BC patient cells statistically significantly. Both drugs reduced cox1 expression in healthy volunteers and cancer patients lymphocytes. Moreover, cox2 reduction was only in lymphocytes from BC patients. The results of this work are consistent with the view that NSAIDs, particularly aspirin and ibuprofen, could have a promising role in cancer treatment including breast cancer. / Libyan Government
99

Biomarkers of Genotoxic and Reprotoxic Effects after Chemical Exposure. The genotoxic effects due to the respiratory disease of Tuberculosis (TB) patients compared to healthy controls in diploid lymphocyte and haploid sperm cells, after treated with two heterocyclic amines and quercetin in bulk and nano forms

Abdulmwli, Mhamoued A.A. January 2019 (has links)
In the tuberculosis patients, Mycobacterium tuberculosis can stimulate production of hydrogen peroxide in the host as a result of immune response. The H2O2 accumulate in pulmonary cells, causing oxidative stress that could lead to the cancer. We select TB patients for this study which investigates the effects of quercetin as there is an increased incidence of latent TB among the migrant population in the past few years and TB can increase the risk of cancer. Sperm and lymphocytes were treated with DNA damage inducers and quercetin (10µM, 25µM and 100µM), the responses evaluated using the Comet and micronucleus techniques. The gene expressions of COX1, COX2, P53 and Bcl-2 and catalase protein expression were investigated using the qPCR and Western blot techniques. The results showed that a substantial reduction of DNA damage in lymphocytes from TB patients and sperm from healthy donors from * P ≤ 0.0283 to *** P≤0.001in the Comet assay. In the MNi assay, the effect of quercetin in lymphocytes was more significant in reduce DNA damage, whereas the DNA damage induced by a food mutagen was significant, from *p 0.0405 to ***p 0.001. The qPCR showed significance down-regulation of COX1 and Bcl-2 gene expression, rated between *p 0.045 and **p 0.0074. However, the catalase protein was up-regulated by the nano form of quercetin when using lymphocytes from TB patients and showed significant changes at *p 0.0236. In conclusion, the nano form was found to be more efficient at the reduction of DNA damage in the Comet and micronucleus assays. Also, it down-regulated COX1 and Bcl-2 and up-regulated the catalase proteins indicating a possible role for quercetin, in genoprotection to TB through its enzyme modulating effect. / Libyan Embassy
100

Use of Fish Biomarkers to Assess the Contaminant Exposure and Effects in Lake Erie Tributaries

Yang, Xuan January 2004 (has links)
No description available.

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