Publications by authors named "Vivian Kahl"

Article Synopsis
  • Telomerase helps many cancers, like acute myeloid leukemia (AML), live longer and here we study a new drug called imetelstat that fights these cancers.
  • We tested imetelstat using special lab-grown cancer samples from real patients and found it can reduce cancer cells, especially in certain genetic types of AML.
  • By understanding how imetelstat works, we created a better treatment plan that combines it with another type of chemotherapy to help it work even better against AML.
View Article and Find Full Text PDF

Brazil is one of the largest consumers of pesticides in the world. This high consumption has resulted in higher potential health risk to agricultural farm workers due to occupational exposure. Hence, the aim of this study is to evaluate genomic instability, using Buccal Micronucleus Cytome (BMCyt) and telomere length (TL) measurement as biomarkers of occupational exposure to pesticides in rural workers living in the State of São Paulo, Brazil.

View Article and Find Full Text PDF

The past decades have shown that telomere crisis is highly affected by external factors. Effects of human exposure to xenobiotics on telomere length (TL), particularly in their workplace, have been largely studied. TL has been shown to be an efficient biomarker in occupational risk assessment.

View Article and Find Full Text PDF

During the harvest period, tobacco workers are exposed to nicotine and it is known that absorption of the alkaloid via the leaves causes green tobacco sickness (GST). We investigated if GST and its symptoms are associated with DNA damage and alterations of the redox status. DNA damage was measured in lymphocytes of tobacco workers and controls (n = 40/group) in single cell gel electrophoresis assays.

View Article and Find Full Text PDF

Telomeres are repetitive regions of DNA bound by specialized proteins at the termini of linear chromosomes that prevent the natural chromosome ends from being recognized as DNA double strand breaks. Telomeric DNA is gradually eroded with each round of cell division, resulting in the accumulation of critically short or dysfunctional telomeres that eventually trigger cellular senescence. Consequently, telomere length is indicative of the proliferative capacity of a cell.

View Article and Find Full Text PDF

Population health research is increasingly focused on the genetic determinants of healthy ageing, but there is no public resource of whole genome sequences and phenotype data from healthy elderly individuals. Here we describe the first release of the Medical Genome Reference Bank (MGRB), comprising whole genome sequence and phenotype of 2570 elderly Australians depleted for cancer, cardiovascular disease, and dementia. We analyse the MGRB for single-nucleotide, indel and structural variation in the nuclear and mitochondrial genomes.

View Article and Find Full Text PDF

Objectives: Lifestyle, obesity, and eating habits are emerging as determinants for the instability of telomeres. The increase in childhood and adolescent obesity and the association of biochemical profiles and dietary components with telomere length (TL) makes it an important issue in nutritional research. The aim of the present study was to investigate TL and its association with ethnic background, adiposity, clinical and biochemical parameters, and dietary patterns among Brazilian children and adolescents.

View Article and Find Full Text PDF

Coal plants represent one of the main sources of environmental pollution due to the combustion process of this mineral and the consequent release of gases and particles which, in significant quantities, can lead to a potential risk to health and the environment. The susceptibility of individuals to the genotoxic effects of coal mining can be modulated by genetic variations in the xenobiotic detoxification and DNA repair processes. The aim of this study was to evaluate if xenobiotic metabolism polymorphism, base excision repair polymorphisms and non-homologous end joining repair polymorphism, could modify individual susceptibility to genomic instability and epigenetic alterations induced in workers by occupational exposure to coal.

View Article and Find Full Text PDF

Pesticides are one of the most frequently investigated chemical, due to their multiple uses in agricultural and public health areas. This study evaluates lymphocytes CBMN (cytokinesis-block micronucleus cytome assay), inflammatory markers, inorganic elements in blood samples, and the relationship of these parameters with XRCC1Arg194Trp, OGG1Ser326Cys and PON1Gln192Arg polymorphisms in a population of tobacco farmers. The study population comprised 129 agricultural workers exposed to pesticides and 91 nonexposed.

View Article and Find Full Text PDF

Coal is a mixture of several chemicals, mainly inorganic elements and polycyclic aromatic hydrocarbons, many of which have mutagenic and carcinogenic effects. Pneumoconiosis, fibrosis, asbestosis, silicosis, emphysema, loss of lung function and cancer are some examples of coal-related disorders. The aim of this study was to analyze coal miners with respect to telomere length (TL) and percentage (%) of global DNA methylation.

View Article and Find Full Text PDF

Background: Genetic damage may occur spontaneously under normal metabolic circumstances, inadequate intake of nutrients, and excessive exposure to environmental mutagens.

Objectives: To evaluate the influence of the intake of micronutrients vitamin B, vitamin B, and folate and of the polymorphism methylenetetrahydrofolate reductase (MTHFR) C677T on the induction of DNA damage in tobacco farmers.

Methods: The study involved 66 men and 44 women engaged in tobacco cultivation in the region of Venâncio Aires (Rio Grande do Sul state, Brazil).

View Article and Find Full Text PDF

Pesticides used at tobacco fields are associated with genomic instability, which is proposed to be sensitive to nutritional intake and may also induce epigenetic changes. We evaluated the effect of dietary intake and genetic susceptibility polymorphisms in (rs1801133) and (rs2736100) genes on genomic and epigenetic instability in tobacco farmers. Farmers, when compared to a nonexposed group, showed increased levels of different parameters of DNA damage (micronuclei, nucleoplasmic bridges, and nuclear buds), evaluated by cytokinesis-block micronucleus cytome assay.

View Article and Find Full Text PDF

Tobacco farming has been proving to induce poor health outcomes in agricultural workers, genomic instability being the triggering one. This study evaluated influence of PON1 (paraoxonase 1), SOD2 (superoxide dismutase), OGG1 (8-oxoguanine glycosylase), XRCC1 (X-ray repair cross-complementing protein 1), and XRCC4 (X-ray repair cross-complementing protein 4) genes polymorphisms on DNA damage in 121 subjects occupationally exposed to pesticides mixtures and nicotine at tobacco fields and 121 non-exposed individuals. Inorganic elements (Cl, P, S and Zn) and cotinine levels were found increased in farmers, confirming exposure.

View Article and Find Full Text PDF
Article Synopsis
  • Tobacco farming in Brazil is a major source of income but exposes farmers to harmful pesticides and nicotine, which can hurt their health.
  • A study found that tobacco farmers had more DNA damage and shorter telomeres (which are like protective caps on DNA) compared to those not exposed to these chemicals.
  • This damage was linked to the number of years they worked with tobacco, showing that the longer they were exposed, the more harm there was to their DNA.
View Article and Find Full Text PDF

Various pesticides in the form of mixtures must be used to keep tobacco crops pest-free. Recent studies have shown a link between occupational exposure to pesticides in tobacco crops and increased damage to the DNA, mononuclei, nuclear buds and binucleated cells in buccal cells as well as micronuclei in lymphocytes. Furthermore, pesticides used specifically for tobacco crops shorten telomere length (TL) significantly.

View Article and Find Full Text PDF

Metal ions such as iron can induce DNA damage by inducing reactive oxygen species (ROS) and oxidative stress. Vitamin C is one of the most widely consumed antioxidants worldwide, present in many fruits and vegetables, especially inMalpighia glabra L., popularly known as acerola, native to Brazil.

View Article and Find Full Text PDF

Occupational exposure to pesticides in tobacco fields causes genetic damage in farmers. The aim of this study was to analyze tobacco farmers chronically exposed to low doses of pesticides and nicotine (present in the tobacco leaves) in relation to absolute telomere length (aTL), and explore the influence of lifestyle characteristics, oxidative stress, and inorganic element levels. DNA was isolated from peripheral blood samples from agricultural workers and non-exposed individuals, and aTL was measured by quantitative real time polymerase chain reaction (qPCR) analysis.

View Article and Find Full Text PDF

Malpighia glabra L, popularly known as acerola, is considered a functional fruit and therefore is taken to prevent disease or as adjuvant to treatment strategies, since the fruit is an undeniable source of vitamin C, carotenoids, and flavonoids. Acerola is a natural source of vitamin C, flavonoids, and carotenoids. Its chemical composition is affected by genetic uniformity of the orchards and environmental factors.

View Article and Find Full Text PDF

Tobacco is a major Brazilian cash crop. Tobacco farmers apply large amounts of pesticides to control insect growth. Workers come into contact with green tobacco leaves during the tobacco harvest and absorb nicotine through the skin.

View Article and Find Full Text PDF

Tobacco farming presents several hazards to those who cultivate and harvest the plant. The genotoxic and mutagenic effects in tobacco farmers were investigated. In order to verify the relationship between genetic susceptibility and biomarkers GSTT1, GSTM1, GSTP1, CYP2A6, PON, OGG1, RAD51, XRCC1, and XRCC4 genes polymorphism were evaluated.

View Article and Find Full Text PDF
Article Synopsis
  • * Researchers studied how vitamin C, an antioxidant, affects nicotine's genotoxic effects in mice using specific tests to measure DNA damage.
  • * Mice treated with vitamin C 24 hours before being exposed to nicotine showed significant protection against DNA damage caused by nicotine.
View Article and Find Full Text PDF

Genotoxic and antigenotoxic effects of acerola fruit at two stages of ripeness were investigated using mice blood cells. The results show that no ripeness stage of acerola extracts presented any genotoxic potential to damage DNA (Comet assay) or cytotoxicity (MTT assay). When antigenotoxic activity was analyzed, unripe fruit presented higher DNA protection than ripe fruit (red color) extract.

View Article and Find Full Text PDF

Duloxetine is a potent inhibitor of serotonin and noradrenaline reuptake, with weak effects on dopamine reuptake, used in the treatment of major depression. It has been recognized that some antidepressants can affect memory in humans, but there is not study that report the duloxetine effect on memory using the inhibitory avoidance. The aim of this work was to investigate the effect of duloxetine on short- and long-term memory (STM and LTM) in the inhibitory avoidance task in mice.

View Article and Find Full Text PDF