scholarly journals Incremental distribution of strontium and zinc in great ape and fossil hominin cementum using synchrotron X-ray fluorescence mapping

2018 ◽  
Vol 15 (138) ◽  
pp. 20170626 ◽  
Author(s):  
Christopher Dean ◽  
Adeline Le Cabec ◽  
Kathryn Spiers ◽  
Yi Zhang ◽  
Jan Garrevoet

Cementum and the incremental markings it contains have been widely studied as a means of ageing animals and retrieving information about diet and nutrition. The distribution of trace elements in great ape and fossil hominin cementum has not been studied previously. Synchrotron X-ray fluorescence (SXRF) enables rapid scanning of large tissue areas with high resolution of elemental distributions. First, we used SXRF to map calcium, phosphorus, strontium and zinc distributions in great ape dentine and cementum. At higher resolution, we compared zinc and strontium distributions in cellular and acellular cementum in regions where clear incremental markings were expressed. We then mapped trace element distributions in fossil hominin dentine and cementum from the 1.55–1.65 million year old site of Koobi Fora, Kenya. Zinc, in particular, is a precise marker of cementum increments in great apes, and is retained in fossil hominin cementum, but does not correspond well with the more diffuse fluctuations observed in strontium distribution. Cementum is unusual among mineralized tissues in retaining so much zinc. This is known to reduce the acid solubility of hydroxyapatite and so may confer resistance to resorption by osteoclasts in the dynamic remodelling environment of the periodontal ligament and alveolar bone.

2018 ◽  
Author(s):  
Ian Towle

Tertiary dentine forms when an odontoblast is directly affected by stimuli, commonly through occlusal wear. In this study the presence of tertiary dentine is recorded in three South African fossil hominin species (Australopithecus africanus, Homo naledi and Paranthropus robustus), and two extant great ape species (Gorilla gorilla gorilla and Pan troglodytes). Frequencies of tertiary dentine were calculated for each species based on macroscopic observations of teeth with dentine exposed through occlusal wear. Overall, the three hominin species have similar tertiary dentine frequencies ranging from 12% to 16.13%. In contrast, over 90% of gorilla teeth with dentine visible show tertiary dentine. Chimpanzees fall between these extremes with 47.21% of teeth affected. Species variances are not related to differences in occlusal wear. Instead, some species appear predisposed to produce tertiary dentine earlier and/or faster than other species. Therefore, tertiary dentine formation has the potential to provide useful information on fossil specimens. For example, the uniformly low rate of tertiary dentine formation in hominins may be due to thick enamel having a similar role in preventing loss of function of teeth, i.e., extending the life of a tooth. In contrast tertiary dentine is clearly an important mechanism for normal dental function in gorillas, and may have evolved to maintain sheering surfaces for masticating tough vegetation.


2018 ◽  
Author(s):  
Ian Towle

Tertiary dentine forms when an odontoblast is directly affected by stimuli, commonly through occlusal wear. In this study the presence of tertiary dentine is recorded in three South African fossil hominin species (Australopithecus africanus, Homo naledi and Paranthropus robustus), and two extant great ape species (Gorilla gorilla gorilla and Pan troglodytes). Frequencies of tertiary dentine were calculated for each species based on macroscopic observations of teeth with dentine exposed through occlusal wear. Overall, the three hominin species have similar tertiary dentine frequencies ranging from 12% to 16.13%. In contrast, over 90% of gorilla teeth with dentine visible show tertiary dentine. Chimpanzees fall between these extremes with 47.21% of teeth affected. Species variances are not related to differences in occlusal wear. Instead, some species appear predisposed to produce tertiary dentine earlier and/or faster than other species. Therefore, tertiary dentine formation has the potential to provide useful information on fossil specimens. For example, the uniformly low rate of tertiary dentine formation in hominins may be due to thick enamel having a similar role in preventing loss of function of teeth, i.e., extending the life of a tooth. In contrast tertiary dentine is clearly an important mechanism for normal dental function in gorillas, and may have evolved to maintain sheering surfaces for masticating tough vegetation.


2012 ◽  
Vol 92 (2) ◽  
pp. 166-172 ◽  
Author(s):  
B.L. Foster ◽  
Y. Soenjaya ◽  
F.H. Nociti ◽  
E. Holm ◽  
P.M. Zerfas ◽  
...  

Bone sialoprotein (BSP) is an extracellular matrix protein found in mineralized tissues of the skeleton and dentition. BSP is multifunctional, affecting cell attachment and signaling through an RGD integrin-binding region, and acting as a positive regulator for mineral precipitation by nucleating hydroxyapatite crystals. BSP is present in cementum, the hard tissue covering the tooth root that anchors periodontal ligament (PDL) attachment. To test our hypothesis that BSP plays an important role in cementogenesis, we analyzed tooth development in a Bsp null (-/-) mouse model. Developmental analysis by histology, histochemistry, and SEM revealed a significant reduction in acellular cementum formation on Bsp-/- mouse molar and incisor roots, and the cementum deposited appeared hypomineralized. Structural defects in cementum-PDL interfaces in Bsp-/- mice caused PDL detachment, likely contributing to the high incidence of incisor malocclusion. Loss of BSP caused progressively disorganized PDL and significantly increased epithelial down-growth with aging. Bsp-/- mice displayed extensive root and alveolar bone resorption, mediated by increased RANKL and the presence of osteoclasts. Results collected here suggest that BSP plays a non-redundant role in acellular cementum formation, likely involved in initiating mineralization on the root surface. Through its importance to cementum integrity, BSP is essential for periodontal function.


Author(s):  
M. L. Zimny ◽  
A. C. Haller

During hibernation the ground squirrel is immobile, body temperature reduced and metabolism depressed. Hibernation has been shown to affect dental tissues varying degrees, although not much work has been done in this area. In limited studies, it has been shown that hibernation results in (1) mobilization of bone minerals; (2) deficient dentinogenesis and degeneration of alveolar bone; (3) presence of calculus and tears in the cementum; and (4) aggrevation of caries and pulpal and apical tooth abscesses. The purpose of this investigation was to study the effects of hibernation on dental tissues employing scanning electron microscopy (SEM) and related x-ray analyses.


1994 ◽  
Vol 31 (5) ◽  
pp. 546-552 ◽  
Author(s):  
T. Yanai ◽  
T. Masegi ◽  
K. Ueda ◽  
J. Manabe ◽  
M. Teranishi ◽  
...  

Mineralization of various degrees was found in the brains of 79 (59%) of 134 cynomolgus monkeys ( Macaca fascicularis). There was no age dependency in the incidence or severity, nor were there any abnormalities in growth, weight gain, or neurologic signs, although a slight sex difference was observed. The lesions, which were basophilic and intensely positive for periodic acid-Schiff or von Kossa stain, occurred in the vascular walls of the globus pallidus in two types: globoid bodies with prominent concentric lamellar structures in and around the arteriolar and venular wall (type A) and fine granules in the media of small or medium-sized arteries (type B). Electron microscopic examination revealed dense deposits in the degenerated media of small or medium-sized arteries or the thickened walls of the arterioles. X-ray microanalysis demonstrated the presence of calcium, phosphorus, iron, zine, magnesium, and aluminum.


2003 ◽  
Vol 49 (10) ◽  
pp. 559-565 ◽  
Author(s):  
Kazuhide NOGUCHI ◽  
Yoshiki HAMADA ◽  
Toshirou KONDOH ◽  
Mitsuyoshi IINO ◽  
Kouta NIITSU ◽  
...  

2017 ◽  
Vol 4 (1) ◽  
pp. 47-59 ◽  
Author(s):  
Hélène Marie De Nys ◽  
Therese Löhrich ◽  
Doris Wu ◽  
Sébastien Calvignac-Spencer ◽  
Fabian Hubertus Leendertz

Abstract. Humans and African great apes (AGAs) are naturally infected with several species of closely related malaria parasites. The need to understand the origins of human malaria as well as the risk of zoonotic transmissions and emergence of new malaria strains in human populations has markedly encouraged research on great ape Plasmodium parasites. Progress in the use of non-invasive methods has rendered investigations into wild ape populations possible. Present knowledge is mainly focused on parasite diversity and phylogeny, with still large gaps to fill on malaria parasite ecology. Understanding what malaria infection means in terms of great ape health is also an important, but challenging avenue of research and has been subject to relatively few research efforts so far. This paper reviews current knowledge on African great ape malaria and identifies gaps and future research perspectives.


2021 ◽  
Vol 74 (8) ◽  
pp. 1869-1875
Author(s):  
Svitlana P. Yarova ◽  
Iryna I. Zabolotna ◽  
Olena S. Genzytska ◽  
Andrii A. Komlev

The aim: Is to define dentine chemical composition of intact teeth and those with wedge-shaped defects followed by the analysis of revealed differences. Materials and methods: Longitudinal sections of 22 clinically removed teeth (12 – clinically intact ones, 10 – with wedge-shaped defects) from both jaws were studied in patients aged between 25-54 years. JSM-6490 LV focused beam electron microscope (scanning) with system of energy-dispersive X-ray microanalysis INCA Penta FETх3 was used. The chemical composition of 148 dentine areas in the incisal region (tubercle), equator, cervical area has been determined as a percentage of the weight amounts of carbon, oxygen, calcium, phosphorus, sodium, magnesium, sulfur, chlorine, zinc, potassium, aluminum. Results: Dentine chemical composition of teeth with wedge-shaped defects differed from those of intact teeth by significantly lower content: sodium, chlorine and calcium – in the incisal region (tubercle); sodium, magnesium − at the equator; sodium, chlorine and calcium – in the cervical region (p≤0.05). In the sample groups with cervical pathology there was more sulfur and oxygen in the incisal region (tubercle), phosphorus and zinc – at the equator, carbon and potassium – in the cervical region (p≤0.05). Conclusions: Differences in the chemical composition of intact teeth and teeth with wedge-shaped defects, the presence of correlation between the studied chemical elements confirm the role of macro- and microelements in the pathogenesis of non-carious cervical lesions.


2011 ◽  
Vol 399-401 ◽  
pp. 855-859
Author(s):  
Ting Ting Wu ◽  
Bo Lin Wu

In order to improve the acid resistance and reduce the apparent density of fracturing proppants, TiO2 powder added in the system of BaO-MgO-Al2O3 fracturing proppants were prepared by the technique of pressureless sintering. The properties of the samples were investigated by the measurements of acid solubility, X-ray diffraction and scanning electron microscopy. The results show that the acid solubility of alumina matrix fracturing proppants contenting TiO2 of the 4wt% and BaO/MgO with the ratio of 3:7 is 0.15%. It is an important development in acid resistance performance of fracturing proppants research on laboratory. TiO2 is added to the raw materials and then calcine them to ceramics, which can reduces the sintering temperature, promote the densification and improve acid-resistant property of fracturing proppants.


Author(s):  
Patrick Roberts

The evolutionary proximity of the non-human great apes to us is often stressed in studies of animals, such as Kanzi, a bonobo (Pan paniscus) bred in captivity, that demonstrate their capacity to undertake tool-use and even utilize and comprehend language (Toth et al., 1993; Savage-Rumbaugh and Lewin, 1996; Schick et al., 1999). Likewise, studies of chimpanzees (Pan spp.) have highlighted the similarity of their emotional and empathetic capacities to those of humans (Parr et al., 2005; Campbell and de Waal, 2014). However, as noted by Savage- Rumbaugh and Lewin (1996), in palaeoanthropology and archaeology more broadly, the emergence of the hominin clade and, later, our species, is referenced in terms of the ‘chasm’ between ourselves and other extant great apes. Indeed, despite our genetic and behavioural proximity, extant non-human great ape taxa are often popularly characterized as living fossils of how we used to be. They are used as analogues for the subsistence and behaviour of the Last Common Ancestor (LCA) of humans and non-human great apes (Clutton-Brock and Harvey, 1977; Goodall, 1986; Foley and Lewin, 2004) and it is almost as if the fact that they still occupy the tropical environments in which these hominoids likely evolved (though see Elton, 2008) allows them to be treated as static comparisons (Figure 3.1). Since Darwin wrote the Descent of Man in 1871, the forests of the tropics, and their modern non-human great ape inhabitants, have tended to be perceived as being left behind as the hominin clade gained increasingly ‘human’ traits of tool-use, medium to large game hunting, and upright locomotion on open ‘savanna’ landscapes (Dart, 1925; Potts, 1998; Klein, 1999). From this perspective it is perhaps unsurprising that tropical forests are seen as alien to the genus Homo and its closest hominin ancestors.


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