In other to present a series of stochastic models from population dynamics capable of describing rudimentary aspects of genetic evolution, we studied two-allele Wright–Fisher and the Moran models for evolution of the relative frequencies of two alleles at a diploid locus under random genetic drift in a population of fixed size “simplest form, selection, and random mutation”. Principal results were presented in qualitative terms, illustrated by Monte Carlo simulations from R and http://www.radford.edu/~rsheehy/Gen_flash/popgen. Moran and the Wright-Fisher Models exhibited the same fixation probabilities, only that the Moran model runs twice as fast as the Wright-Fisher Model. A clue that can help us to understand this result is provided by the variance in reproductive success in the two models. Genetic changes due to drift were neither directional nor predictable in any deterministic way. Nonetheless, genetic drift led to evolutionary change in the absence of mutation (P=0.5), natural selection or gene flow. In general, alleles drift to fixation is significantly faster in smaller populations. Probability of fixation of an allele A was approximately equivalent to the initial frequency of that allele. With the inclusion of selection in our model, probability of fixation of a favoured allele due to natural selection increased with increase in fitness advantage and population size. The time taken to reach fixation is much slower, in case of no selective advantage, than a fixation under mutation with selective advantage. Show less

Benzene is known as an environmental and industrial pollutant. One way to check the amount of exposure to benzene is to measure its metabolites in the urine. Trans, Trans-Muconic Acid which is one of its metabolites is also as a biological indicator of exposure to benzene. In this study, the relationship between the amount of this biomarker and the environmental benzene concentration was investigated in two groups of policemen working outdoors in the traffic-congested areas and indoor in the same area. The results showed that the highest amount of benzene was in Salman Farsi Station at 4.44 ppm. At the same time, the biomarker measured in the urine showed 127.20 μg / L, which was the highest amount. In addition, the amount of benzene in the outdoor was approximately 3 times more than indoor and the amount of biomarker measured in outdoor employees was two times more than indoors ones. In general, wherever there was more benzene, the biomarker would also show a higher amount. Show less

Introduction Genomic mutations in TP53 gene in association with etiological risk factors have been associated with oral carcinogenesis. Herein, we screened for genomic variants of TP53 predisposing to oral cancers in Senegalese patients. Methodology 88 patients with confirmed diagnostic were recruited after informed consent. Blood samples were collected from each patient to perform DNA extraction, PCR amplification of all coding exons of TP53 followed by Sanger Sequencing of PCR products. Nucleotide sequences were analysed with Genalys software. 94 blood donors with no cancer diagnosis were also recruited as controls for association study between the most common variants identified in patients and predisposition to oral cancers. Results Sequence analysis showed that 52.27% of patients carry at least one mutation in TP53. Eleven genomic variants were identified, 7 variants already reported in databases and 4 new variants. The most recurrent variants in this study already reported as cancer-related variants were Pro72Arg (rs1042522; Arginine frequency estimated at 31.26%) and a 16 bp insertion in intron 3 (rs59758982; allelic frequency estimated at 26.25%). Haplotype analysis between these variants showed a strong linkage disequilibrium (D’ = 0.999, r2 = 0.153 and p-value < 0.05). However, association study did not find any significant association with susceptibility to oral cancer (p-value > 0.05). Conclusion Our study highlighted that despite the absence of association between the two most common cancer-related variants in Senegalese patients diagnosed with oral cancer, their strong LD suggested that they could be transmitted together in a common haplotype which may be implicated in oral carcinogenesis. Show less

Upon considering the anticancer effects of larger oligomeric proanthocyanidins and observing various papers reporting the high resolution mass spectroscopy of the oligomeric proanthocyanidins, it is determined that the unusual 13C enrichment in some plant oligomeric proanthocyanidins may be responsible for the anticancer activities of these food products. Such correlation of the 13C in the oligomeric proanthocyanidins also correlate with their scavenging of free-radicals, anti-virial and anti-bacterial properties. Proanthocyanidins in grape seeds are observed to have high enrichment in heavy isotopes of 2H, 13C, 15N and/or 17O. Mass analysis of DNA from human cancer cells are compared to normal human cells and cancer cells show bond specific enrichment of heavy isotopes in nucleotides G, A, T and C. On such basis, this study suggests possible stronger interactions of proanthocyanidins with DNA in cancer verses DNA in normal cells due to heavy isotope bond specific enrichments in both proanthocyanidins and the cancer DNA. Such 13C interactions from oligomeric proanthocyanidins with nucleic acids and proteins involved in replications, transcriptions and translations in cancer cells for interacting and chemically altering anabolism and cell division of the cancer cells are consistent with the author’s mechanism for normal cell to cancer cell transformations via possible replacements of primordial 1H, 12C, 14N, 16O, and 24Mg isotopes by nonprimordial 2H, 13C, 15N, and 17O and 25Mg isotopes in the proteins and nucleic acids. Such is also consistent with the proposed treatment for cancer by the author by use of foods containing proteins, nucleic acids, carbohydrates and/or drug molecules enriched with the nonprimordial isotopes of 2H, 13C, 15N, and 17O and 25Mg. Show less