Limiting the impact of destructive analytical techniques through sequential microspatial sampling of the enamel from single teeth

A fundamental research concern within contemporary bioarchaeology is the sensitive balance between the preservation of human remains and the use of destructive techniques to collect information. Here we describe one example of how multiple microspatial destructive/semi-destructive techniques may be carried out in sequence using only the enamel of a single tooth. With careful planning of both sample preparation strategies and sequencing of sampling methods, it is possible to produce multiple datasets, and yet to retain material for future analyses. In this case, enamel from the teeth of 27 individuals who lived during the early medieval period (AD 1170-1198) in Bergen, Norway, were subjected to histological, trace element (LA-ICP-MS), diagenetic (FTIR), and isotopic analyses (δ18O and δ13C, via micromill/multiprep/IRMS)

An integrative analysis of how zinc in teeth reflects maternal environments and predicts infant function in a rural Mexican community

The assessment and interpretation of zinc (Zn) concentrations derived from chemical analyses of biological hard tissues has been troubled by the complexities inherent in working with an essential trace element implicated in several important biological processes. Because Zn is subject to some homeostatic control by the body and does not undergo a clear trophic level separation several researchers have suggested its utility for paleodietary reconstruction is severely limited. However, with an understanding of the nature of Zn physiology, nutrient interactions and local factors affecting bioavailability it may yet be possible to utilize measures of hard tissue Zn concentrations in evaluating diet, health and children\u27s functional outcomes. Pre-and-postnatal enamel Zn levels were determined via laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) for 80 teeth collected from 46 infants participating in a large longitudinal study in the Solís Valley, Mexico, during the mid-1980s. Relationships between enamel Zn levels and ∼200 variables documenting maternal diet, infant growth, morbidity and cognitive development were explored. The results indicate that an infant\u27s prenatal enamel Zn content reflects their mother\u27s pregnancy dietary quality. Infants born into the poorest households, and who were exposed to poor quality diets, have the highest concentrations of zinc in their prenatal enamel. Further, prenatal enamel Zn levels are predictive of the cognitive development of Solís infants. Postnatal enamel zinc amounts reflect maternal weight gain during pregnancy and predict the onset of certain illnesses (e.g. common cold, influenza) during infancy. The uptake of Zn by postnatal enamel is likely determined by mothers\u27 storage of zinc in bone over the years preceding her pregnancy, as well as by both her pregnancy and lactation diets. This research demonstrates that, despite the fact that zinc is an essential element, its variation within deciduous teeth can be understood in terms of variation in socioeconomic status and maternal diets, and that it can in turn be predictive of individuals\u27 future functional outcomes. From a biocultural anthropological perspective these results are remarkable in that they clarify one of the mechanisms by which the biological effects of social inequality are recycled from one generation to the next

Exploring childhood mobility in Neolithic Southern France (Roquemissou) using incremental analyses of Sr isotope ratios in tooth enamel

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Pathoecology and paleodiet in Postclassic/Historic Maya from Northern Coastal Belize

This paper examines the synergism among diet, disease, and ecology at two related coastal Maya sites in Belize (Marco Gonzalez and San Pedro) for the Postclassic and Historic periods (1350-1650 AD), which immediately follow the Classic period collapse. Stable carbon- and nitrogen-isotope ratios in collagen and stable carbon-isotope ratios in structural carbonate were analysed for bones from 65 humans and a wide variety of faunal species. There are no apparent differences in whole diets or degree of carnivory between individuals with lesions indicative of anemia and those without, but those with lesions appear to have consumed significantly more C4 foods and protein from lower trophic levels. Non-specific infection (periostitis) and vitamin C deficiency (scurvy) are also present in high frequencies and appear to co-occur with lesions indicative of anemia, particularly in childhood. Individuals with scurvy also appear to have consumed significantly more C4 foods than normal individuals. Spondyloarthropathy is common in adults. These findings are discussed in light of: (1) the debate on how anemia versus scurvy are manifest and diagnosed, (2) Spanish ethnohistoric descriptions of the poor state of Maya health at the time of contact, and (3) the Osteological Paradox. We suggest that although this coastal environment exacerbated morbidity because of possible parasitic infection, the inhabitants were probably able to survive physiological stresses better than either their inland contemporaries or their modern counterparts

Ancient Clostridium DNA and variants of tetanus neurotoxins associated with human archaeological remains

The analysis of microbial genomes from human archaeological samples offers a historic snapshot of ancient pathogens and provides insights into the origins of modern infectious diseases. Here, we analyze metagenomic datasets from 38 human archaeological samples and identify bacterial genomic sequences related to modern-day Clostridium tetani, which produces the tetanus neurotoxin (TeNT) and causes the disease tetanus. These genomic assemblies had varying levels of completeness, and a subset of them displayed hallmarks of ancient DNA damage. Phylogenetic analyses revealed known C. tetani clades as well as potentially new Clostridium lineages closely related to C. tetani. The genomic assemblies encode 13 TeNT variants with unique substitution profiles, including a subgroup of TeNT variants found exclusively in ancient samples from South America. We experimentally tested a TeNT variant selected from an ancient Chilean mummy sample and found that it induced tetanus muscle paralysis in mice, with potency comparable to modern TeNT. Thus, our ancient DNA analysis identifies DNA from neurotoxigenic C. tetani in archaeological human samples, and a novel variant of TeNT that can cause disease in mammals.</p

Ancient Clostridium DNA and variants of tetanus neurotoxins associated with human archaeological remains

Abstract The analysis of microbial genomes from human archaeological samples offers a historic snapshot of ancient pathogens and provides insights into the origins of modern infectious diseases. Here, we analyze metagenomic datasets from 38 human archaeological samples and identify bacterial genomic sequences related to modern-day Clostridium tetani, which produces the tetanus neurotoxin (TeNT) and causes the disease tetanus. These genomic assemblies had varying levels of completeness, and a subset of them displayed hallmarks of ancient DNA damage. Phylogenetic analyses revealed known C. tetani clades as well as potentially new Clostridium lineages closely related to C. tetani. The genomic assemblies encode 13 TeNT variants with unique substitution profiles, including a subgroup of TeNT variants found exclusively in ancient samples from South America. We experimentally tested a TeNT variant selected from an ancient Chilean mummy sample and found that it induced tetanus muscle paralysis in mice, with potency comparable to modern TeNT. Thus, our ancient DNA analysis identifies DNA from neurotoxigenic C. tetani in archaeological human samples, and a novel variant of TeNT that can cause disease in mammals