65 research outputs found

    Increased plasma von Willebrand factor antigen levels but normal von Willebrand factor cleaving protease (ADAMTS13) activity in preeclampsia.

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    The activity of ADAMTS13, the von Willebrand factor (VWF) cleaving protease is low in several conditions, including HELLP (haemolysis, elevated liver enzymes, and low platelet count) syndrome. As HELLP syndrome develops in most cases on the basis of preeclampsia, our aim was to determine whether plasma ADAMTS13 activity is decreased in preeclampsia. Sixty-seven preeclamptic patients, 70 healthy pregnant women and 59 healthy non-pregnant women were involved in this case-control study. Plasma ADAMTS13 activity was determined with the FRETS-VWF73 assay, while VWF antigen (VWF:Ag) levels with an enzyme-linked immunosorbent assay. The multimeric pattern of VWF was analyzed by SDS-agarose gel electrophoresis. There was no significant difference in plasma ADAMTS13 activity between the preeclamptic and the healthy pregnant and non-pregnant groups (median [25-75 percentile]: 98.8 [76.5-112.8] %, 96.3 [85.6-116.2] % and 91.6 [78.5-104.4] %, respectively; p > 0.05). However, plasma VWF:Ag levels were significantly higher in preeclamptic patients than in healthy pregnant and non-pregnant women (187.1 [145.6-243.1] % versus 129.3 [105.1-182.8] % and 70.0 [60.2-87.3] %, respectively; p < 0.001). The multimeric pattern of VWF was normal in each group. Primiparas had lower plasma ADAMTS13 activity than multi-paras (92.6 [75.8-110.6] % versus 104.2 [92.1-120.8] %; p = 0.011). No other relationship was found between clinical characteristics, laboratory parameters and plasma ADAMTS13 activity in either study group. In conclusion, plasma ADAMTS13 activity is normal in preeclampsia despite the increased VWF:Ag levels. However, further studies are needed to determine whether a decrease in plasma ADAMTS13 activity could predispose preeclamptic patients to develop HELLP syndrome

    Case Study from Máza Brickyard (SW-Hungary): Paleoecology and Sediment Accumulation Changes in the Southern Part of the Carpathian Basin

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    The loess–paleosol profile of Máza brickyard in SW Hungary was investigated through multivariate analyses of malacofauna and sedimentological analyses. The aim was to reconstruct the complex developmental history of both sediment and malacofauna. Three age–depth models were calculated, and the best-fit model, the OxCal P-sequence, was chosen for further analysis. The profile overlays the MIS3 and MIS2, beginning at approximately 45,000–50,000 cal BP and ending at the Pleistocene/Holocene boundary. The accumulation rates were two periods of intensive accumulation, equal to those observed in the Bácska Loess Plateau in Hungary, and two periods of decreased accumulation. Between ~38,000 and 31,000 cal BP, a decreased accumulation period was observed in Máza and other profiles from the Bácska Loess Plateau, indicating a common weak accumulation period at the end of MIS3. Correspondence and cluster analyses provided a higher-resolution paleoecological reconstruction, revealing a more detailed picture of the evolution of the studied section. The presence of thermophilous gastropod species with a high contribution to the correspondence analysis was significant in the sections. Although Granaria frumentum, Helicopsis striata, Chondrula tridens, and Pupilla triplicata were not significant species in the Máza malacofauna as a whole, their presence was associated with warming periods and the emergence of open vegetation

    Development History of the Loess–Paleosol Profiles of Pécel, Kisdorog and Bonyhádvarasd, Hungary

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    This study covers the examination of four loess–paleosol profiles in Hungary through grain size composition, organic matter, carbonate content and magnetic susceptibility measurements. One of the profiles (with a thickness of 25.72 m) can be found in the Gödöllő hills, on the border of town Pécel, and the other three profiles (Kisdorog-West—5.60 m, Kisdorog-East—6.40 and Bonyhádvarasd—8.16 m) are located in the Tolna hills of the Transdanubia region. The sections were continuously sampled with an interval of 4 cm. The same interval was also applied to the other three profiles. During the field exploration of the Pécel profile, we were able to study the complete loess wall, which was deposited on the sediment of the nearby Rákos stream. Based on the Ostracod fauna of the clay sediment beneath, the fluvial deposit can be considered as originating from the Upper Miocene. In the case of the Transdanubian sections, a significant change can be observed in the prevailing wind direction based on the grain size analyses. In addition, the results of magnetic susceptibility measurements suggest that the development of the Pécel profile took place during MIS 9–10, while the age of the three Transdanubian sections can be assumed to be the MIS 2–4

    Applying grain-size and compositional data analysis for interpretation of the Quaternary oxbow lake sedimentation processes: Eastern Great Hungarian Plain

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    Grain size distribution is one of the paleoenvironmental proxies that provide insight statistical distribution of size fractions within the sediments. Multivariate statistics have been used to investigate the depositional process from the grain size dis-tribution. Still, the direct application of the standard multivariate methods is not straightforward and can yield misleading interpretations due to the compositional nature of the raw grain size data. This paper is a methodological framework for grain size data characterization through the centered log ratio transformation and euclidean data, coupled with principal component analysis, cluster analysis, and linear discriminant analysis to examine Quaternary sediments from Tovises bed in the southeast Great Hungarian Plain. These approaches provide statistically significant and sedimentologically interpretable results for both datasets. However, the details by which they supplemented the conceptual model were sig-nificantly different, and this discrepancy resulted in a different temporal model of the depositional history

    Application of Parameterized Grain-Size Endmember Modeling in the Study of Quaternary Oxbow Lake Sedimentation: A Case Study of Tövises Bed Sediments in the Eastern Great Hungarian Plain

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    Abandoned channels are essential in the Quaternary floodplains, and their infill contains different paleoenvironment recorders. Grain-size distribution (GSD) is one proxy that helps characterize the alluviation and associated sedimentological processes of the abandoned channels. The classic statistical methods of the grain-size analysis provide insufficient information on the whole distribution; this necessitates a more comprehensive approach. Grain-size endmember modeling (EMM) is one approach beyond the traditional procedures that helps unmix the GSDs. This study describes the changes in the depositional process by unmixing the GSDs of a Holocene abandoned channel through parameterized EMM integrated with lithofacies, age–depth model, loss-on-ignition (LOI), and magnetic susceptibility (MS). This approach effectively enabled the quantification and characterization of up to four endmembers (EM1-4); the characteristics of grain-size endmembers imply changes in sedimentary environments since 8000 BP. EM1 is mainly clay and very fine silt, representing the fine component of the distribution corresponding to the background of quiet water sedimentation of the lacustrine phase. EM2 and EM3 are the intermediate components representing the distal overbank deposits of the flood. EM4 is dominated by coarse silt and very fine sand, representing deposition of overbank flow during the flood periods. This paper demonstrates that the parametrized grain-size EMM is reasonable in characterizing abandoned channel infill sedimentary depositional and sedimentation history
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