Modulation of Colorectal Cancer Risk by Polymorphisms in 51Gln/His, 64Ile/Val, and 148Asp/Glu of APEX Gene; 23Gly/Ala of XPA Gene; and 689Ser/Arg of ERCC4 Gene

Polymorphisms in DNA repair genes may affect the activity of the BER (base excision repair) and NER (nucleotide excision repair) systems. Using DNA isolated from blood taken from patients (n = 312) and a control group (n = 320) with CRC, we have analyzed the polymorphisms of selected DNA repair genes and we have demonstrated that genotypes 51Gln/His and 148Asp/Glu of APEX gene and 23Gly/Ala of XPA gene may increase the risk of colorectal cancer. At the same time analyzing the gene-gene interactions, we suggest the thesis that the main factor to be considered when analyzing the impact of polymorphisms on the risk of malignant transformation should be intergenic interactions. Moreover, we are suggesting that some polymorphisms may have impact not only on the malignant transformation but also on the stage of the tumor

Synergistic Effect of Vitamin C on DNA Damage Induced by Cadmium

Abstract. Salts of divalent cadmium are well-known human mutagens and carcinogens. In the present work, the ability of vitamin C to modulate genotoxic effects of cadmium chloride on human lymphocytes was assessed using single cell gel electrophoresis (comet assay). Vitamin C at 20 and 100 µmol/l and cadmium at 5, 30 and 150 µmol/l significantly increased the tail moment of lymphocytes. Vitamin C also increased the tail moment of cells exposed to cadmium. This effect was concentration-dependent: the higher the vitamin C concentration the greater the tail moment. The combined effects of cadmium and vitamin C were more pronounced at all concentrations tested than the sum of the effects of the compounds applied separately (p < 0.05), so cadmium and vitamin C can be considered to have synergistic effects. The results obtained can be partly explained by the participation of cadmium in the Fenton reaction and reduction of its oxidized form by vitamin C

Situating households within an urban community:recent research at Aventura, an ancient Maya city

Recent excavations at the Maya site of Aventura, Belize provide insights into the social, economic, and environmental resources available to the residents of its ancient urban community. In 2019, the Aventura Archaeology Project (AAP) horizontally excavated three households and continued vertical test-pit investigations across commoner and elite domestic groups. The horizontal excavations, comparable to previous excavations of households in 2018, provided new insights into the similarities and differences between structures, features, burials, and middens across status groups at Aventura. One household excavation, Group 54, elucidated commoners’ access and relationships to a nearby water management feature. Commoner household excavations at Group 24, one of the smallest mound features identified by the AAP survey, revealed that even the smallest of Aventura’s households had access, though limited, to cut limestone blocks for domestic architecture. Excavations of an elite patio group, Group 38, to the north of the site core provided architectural data which complicate distinctions between elite and non-elite households. These excavations of households across the site also revealed a pattern of primary and secondary subfloor-burial deposits across elite and non-elite groups, which may indicate an attempt to socially integrate households of all statuses into Aventura’s urban community. Vertical test excavations further support Aventura’s community was inhabited over the long-term, with multiple households revealing Early and Middle Classic materials, and all households revealing occupation during the Late to Terminal Classic transition. Together, household excavations provide insights into the social, economic, and environmental forces that shaped the lives of Aventura’s urban community, bringing better focus to heterogenous and enduring urban populations during dynamic periods of Maya society

Situating households within an urban community:recent research at Aventura, an ancient Maya city

Recent excavations at the Maya site of Aventura, Belize provide insights into the social, economic, and environmental resources available to the residents of its ancient urban community. In 2019, the Aventura Archaeology Project (AAP) horizontally excavated three households and continued vertical test-pit investigations across commoner and elite domestic groups. The horizontal excavations, comparable to previous excavations of households in 2018, provided new insights into the similarities and differences between structures, features, burials, and middens across status groups at Aventura. One household excavation, Group 54, elucidated commoners’ access and relationships to a nearby water management feature. Commoner household excavations at Group 24, one of the smallest mound features identified by the AAP survey, revealed that even the smallest of Aventura’s households had access, though limited, to cut limestone blocks for domestic architecture. Excavations of an elite patio group, Group 38, to the north of the site core provided architectural data which complicate distinctions between elite and non-elite households. These excavations of households across the site also revealed a pattern of primary and secondary subfloor-burial deposits across elite and non-elite groups, which may indicate an attempt to socially integrate households of all statuses into Aventura’s urban community. Vertical test excavations further support Aventura’s community was inhabited over the long-term, with multiple households revealing Early and Middle Classic materials, and all households revealing occupation during the Late to Terminal Classic transition. Together, household excavations provide insights into the social, economic, and environmental forces that shaped the lives of Aventura’s urban community, bringing better focus to heterogenous and enduring urban populations during dynamic periods of Maya society