39 research outputs found

    Identification of Angiotensin I-converting enzyme Inhibitory Activities from traditional Mongolian fermented milk products

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    Several angiotensen-converting enzyme (ACE) inhibitory peptites have been detected in milk products. There are many traditional milk products in Mongolia. For this study, some Mongolian milk products were collected, and the ACE inhibitory activities of these samples were tested; an active fraction was found in aaruul made from mare’s milk. After purification by dialysis and HPLC, the active fractions were isolated. The molecular weight of the active component was 362.05 M, as determined by mass spectrometry. An authentic standard was used to determine the IC50 value of the inhibitory activity. From 5’-GMP is not much higher than that of the active peptide in sour milk and some flavonoids. However, this is the first report that shows that 5’ –GMP inhibits ACE activity. These results will provide useful information for the development of hypertension therapy agents.DOI: http://dx.doi.org/10.5564/mjc.v12i0.175 Mongolian Journal of Chemistry Vol.12 2011: 65-6

    Climate change and equestrian empires in the Eastern Steppes: new insights from a high-resolution Lake Core in Central Mongolia

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    The repeated expansion of East Asian steppe cultures was a key driver of Eurasian history, forging new social, economic, and biological links across the continent. Climate has been suggested as important driver of these poorly understood cultural expansions, but paleo-climate records from the Mongolian Plateau often suffer from poor age control or ambiguous proxy interpretation. Here, we use a combination of geochemical analyses and comprehensive radiocarbon dating to establish the first robust and detailed record of paleo-hydrological conditions for Lake Telmen, Mongolia, covering the past ~4000 years. Our record shows that humid conditions coincided with solar minima, and hydrological modelling confirms the high sensitivity of the lake to paleo-climate changes. Careful comparisons with archaeological and historical records suggest that in the vast semi-arid grasslands of eastern Eurasia, solar minima led to reduced temperatures, less evaporation, and high biomass production, expanding the power base for pastoral economies and horse cavalry. Our findings suggest a crucial link between temperature dynamics in the Eastern Steppe and key social developments, such as the emergence of pastoral empires, and fuel concerns that global warming enhances water scarcity in the semi-arid regions of interior Eurasia.1. Introduction 2. Results 2.1 Sediment core chronology 2.2 Sedimentological and geochemical analyses 2.3 Isotope analyses, evaporation index (EI), and paleohydrology 3. Discussion 3.1 External forcing on the regional climate 3.2 Hydrological modelling 3.3 Climate impact on human history in Mongolia Method

    Plasmodium berghei Hsp90 contains a natural immunogenic I-A<sup>b</sup>-restricted antigen common to rodent and human Plasmodium species

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    Thorough understanding of the role of CD4 T cells in immunity can be greatly assisted by the study of responses to defined specificities. This requires knowledge of Plasmodium-derived immunogenic epitopes, of which only a few have been identified, especially for the mouse C57BL/6 background. We recently developed a TCR transgenic mouse line, termed PbT-II, that produces CD4+ T cells specific for an MHC class II (I-Ab)-restricted Plasmodium epitope and is responsive to both sporozoites and blood-stage P. berghei. Here, we identify a peptide within the P. berghei heat shock protein 90 as the cognate epitope recognised by PbT-II cells. We show that C57BL/6 mice infected with P. berghei blood-stage induce an endogenous CD4 T cell response specific for this epitope, indicating cells of similar specificity to PbT-II cells are present in the naïve repertoire. Adoptive transfer of in vitro activated TH1-, or particularly TH2-polarised PbT-II cells improved control of P. berghei parasitemia in C57BL/6 mice and drastically reduced the onset of experimental cerebral malaria. Our results identify a versatile, potentially protective MHC-II restricted epitope useful for exploration of CD4 T cell-mediated immunity and vaccination strategies against malaria

    Induction of Neuronal Death by Microglial AGE-Albumin: Implications for Alzheimer’s Disease

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    Advanced glycation end products (AGEs) have long been considered as potent molecules promoting neuronal cell death and contributing to neurodegenerative disorders such as Alzheimer’s disease (AD). In this study, we demonstrate that AGE-albumin, the most abundant AGE product in human AD brains, is synthesized in activated microglial cells and secreted into the extracellular space. The rate of AGE-albumin synthesis in human microglial cells is markedly increased by amyloid-β exposure and oxidative stress. Exogenous AGE-albumin upregulates the receptor protein for AGE (RAGE) and augments calcium influx, leading to apoptosis of human primary neurons. In animal experiments, soluble RAGE (sRAGE), pyridoxamine or ALT-711 prevented Aβ-induced neuronal death in rat brains. Collectively, these results provide evidence for a new mechanism by which microglial cells promote death of neuronal cells through synthesis and secretion of AGE-albumin, thereby likely contributing to neurodegenerative diseases such as AD

    Radiocarbon dating and cultural dynamics across Mongolia’s early pastoral transition

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    All necessary permits were obtained for the described study, which complied with all relevant regulations. Collaboration contract between the Max Planck Institute for the Science of Human HIstory and the National University of Mongolia began on the 10th November, 2016. Export number 10/413 (7b/52) was received on the 2nd Feb, 2017 (#A0109258, MN DE 7 643). This research was supported by the Max Planck Institute for the Science of Human History. Special thanks to Dr. Katerina Douka and the Oxford Radiocarbon Accelerator Laboratory for conducting 14C analysis, and to all of the original excavators and authors who published the radiocarbon dates cited in this study.Peer reviewedPublisher PD

    Diverging climate trends in Mongolian taiga forests influence growth and regeneration of Larix sibirica

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    Central and semiarid north-eastern Asia was subject to twentieth century warming far above the global average. Since forests of this region occur at their drought limit, they are particularly vulnerable to climate change. We studied the regional variations of temperature and precipitation trends and their effects on tree growth and forest regeneration in Mongolia. Tree-ring series from more than 2,300 trees of Siberian larch (Larix sibirica) collected in four regions of Mongolia’s forest zone were analyzed and related to available weather data. Climate trends underlie a remarkable regional variation leading to contrasting responses of tree growth in taiga forests even within the same mountain system. Within a distance of a few hundred kilometers (140–490 km), areas with recently reduced growth and regeneration of larch alternated with regions where these parameters remained constant or even increased. Reduced productivity could be correlated with increasing summer temperatures and decreasing precipitation; improved growth conditions were found at increasing precipitation, but constant summer temperatures. An effect of increasing winter temperatures on tree-ring width or forest regeneration was not detectable. Since declines of productivity and regeneration are more widespread in the Mongolian taiga than the opposite trend, a net loss of forests is likely to occur in the future, as strong increases in temperature and regionally differing changes in precipitation are predicted for the twenty-first century

    The origins and spread of domestic horses from the Western Eurasian steppes

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    This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: All collapsed and paired-end sequence data for samples sequenced in this study are available in compressed fastq format through the European Nucleotide Archive under accession number PRJEB44430, together with rescaled and trimmed bam sequence alignments against both the nuclear and mitochondrial horse reference genomes. Previously published ancient data used in this study are available under accession numbers PRJEB7537, PRJEB10098, PRJEB10854, PRJEB22390 and PRJEB31613, and detailed in Supplementary Table 1. The genomes of ten modern horses, publicly available, were also accessed as indicated in their corresponding original publications57,61,85-87.NOTE: see the published version available via the DOI in this record for the full list of authorsDomestication of horses fundamentally transformed long-range mobility and warfare. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 BC. Other longstanding candidate regions for horse domestication, such as Iberia and Anatolia, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC driving the spread of Indo-European languages. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture
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