| 1. |
- Arvidsson, Ida, et al.
(författare)
-
Shiga toxin-induced complement-mediated hemolysis and release of complement-coated red blood cell-derived microvesicles in hemolytic uremic syndrome.
- 2015
-
Ingår i: Journal of Immunology. - : The American Association of Immunologists. - 1550-6606 .- 0022-1767. ; 194:5, s. 2309-2318
-
Tidskriftsartikel (refereegranskat)abstract
- Shiga toxin (Stx)-producing Escherichia coli (STEC) cause hemolytic uremic syndrome (HUS). This study investigated whether Stx2 induces hemolysis and whether complement is involved in the hemolytic process. RBCs and/or RBC-derived microvesicles from patients with STEC-HUS (n = 25) were investigated for the presence of C3 and C9 by flow cytometry. Patients exhibited increased C3 deposition on RBCs compared with controls (p < 0.001), as well as high levels of C3- and C9-bearing RBC-derived microvesicles during the acute phase, which decreased after recovery. Stx2 bound to P1 (k) and P2 (k) phenotype RBCs, expressing high levels of the P(k) Ag (globotriaosylceramide), the known Stx receptor. Stx2 induced the release of hemoglobin and lactate dehydrogenase in whole blood, indicating hemolysis. Stx2-induced hemolysis was not demonstrated in the absence of plasma and was inhibited by heat inactivation, as well as by the terminal complement pathway Ab eculizumab, the purinergic P2 receptor antagonist suramin, and EDTA. In the presence of whole blood or plasma/serum, Stx2 induced the release of RBC-derived microvesicles coated with C5b-9, a process that was inhibited by EDTA, in the absence of factor B, and by purinergic P2 receptor antagonists. Thus, complement-coated RBC-derived microvesicles are elevated in HUS patients and induced in vitro by incubation of RBCs with Stx2, which also induced hemolysis. The role of complement in Stx2-mediated hemolysis was demonstrated by its occurrence only in the presence of plasma and its abrogation by heat inactivation, EDTA, and eculizumab. Complement activation on RBCs could play a role in the hemolytic process occurring during STEC-HUS.
|
|
| 2. |
- Azorin-Molina, C., et al.
(författare)
-
A Decline of Observed Daily Peak Wind Gusts with Distinct Seasonality in Australia, 1941-2016
- 2021
-
Ingår i: Journal of Climate. - : American Meteorological Society. - 0894-8755 .- 1520-0442. ; 34:8, s. 3103-3127
-
Tidskriftsartikel (refereegranskat)abstract
- Wind gusts represent one of the main natural hazards due to their increasing socioeconomic and environmental impacts on, for example, human safety, maritime-terrestrial-aviation activities, engineering and insurance applications, and energy production. However, the existing scientific studies focused on observed wind gusts are relatively few compared to those on mean wind speed. In Australia, previous studies found a slowdown of near-surface mean wind speed, termed "stilling," but a lack of knowledge on the multidecadal variability and trends in the magnitude (wind speed maxima) and frequency (exceeding the 90th percentile) of wind gusts exists. A new homogenized daily peak wind gusts (DPWG) dataset containing 548 time series across Australia for 1941-2016 is analyzed to determine long-term trends in wind gusts. Here we show that both the magnitude and frequency of DPWG declined across much of the continent, with a distinct seasonality: negative trends in summer-spring-autumn and weak negative or nontrending (even positive) trends in winter. We demonstrate that ocean-atmosphere oscillations such as the Indian Ocean dipole and the southern annular mode partly modulate decadal-scale variations of DPWG. The long-term declining trend of DPWG is consistent with the "stilling" phenomenon, suggesting that global warming may have reduced Australian wind gusts.
|
|
| 3. |
- Karpman, D, et al.
(författare)
-
Platelet activation in hemolytic uremic syndrome
- 2006
-
Ingår i: Seminars in Thrombosis and Hemostasis. - : Georg Thieme Verlag. - 0094-6176 .- 1098-9064. ; 32:2, s. 128-145
-
Tidskriftsartikel (refereegranskat)abstract
- Platelet consumption in platelet-fibrin aggregates leading to thrombocytopenia and small vessel obstruction are major features of the hemolytic uremic syndrome (HUS). Although thrombocytopenia has been correlated to poor prognosis, the mechanisms by which thrombocytopenia develops in HUS have not been completely elucidated. However, plausible explanations have been platelet contact with thrombogenic surfaces and/or direct contact with an aggregating agent. This article summarizes several mechanisms of platelet activation, interactions with leukocytes, chemokine release, complement activation, and antimicrobial defense. Specific mechanisms are outlined by which platelets may be activated, leading to thrombocytopenia during HUS. In diarrhea-associated HUS Shiga toxin has been shown to injure the endothelium, thus exposing the subendothelium, releasing tissue factor, and rendering the vessel wall prothrombotic. Shiga toxin also binds to and activates platelets. The toxin may activate endothelial cells and platelets simultaneously. In atypical HUS the alternative complement pathway is activated because of mutations in complement regulatory proteins. Mutated factor H does not bind to endothelium and platelets efficiently, enabling complement activation on these cells. In thrombotic thrombocytopenic purpura, intravascular platelet clotting Occurs due to dysfunction of the von Willebrand factor (VWF)-cleaving protease ADAMTS13. Thrombi are formed by binding of platelets to ultralarge VWF multimers.
|
|
| 4. |
- Minola, Lorenzo, et al.
(författare)
-
The contribution of large-scale atmospheric circulation to variations of observed near-surface wind speed across Sweden since 1926
- 2023
-
Ingår i: Climatic Change. - 0165-0009. ; 176:5
-
Tidskriftsartikel (refereegranskat)abstract
- This study investigates the centennial-scale (i.e., since 1926) variability of observed near-surface wind speed across Sweden. Results show that wind speed underwent various phases of change during 1926-2019, i.e., (a) a clear slowdown during 1926-1960; (b) a stabilization from 1960 to 1990; (c) another clear slowdown during 1990-2003; (d) a slight recovery/stabilization period for 2003-2014, which may continue with a possible new slowdown. Furthermore, the performance of three reanalysis products in representing past wind variations is evaluated. The observed low-frequency variability is properly simulated by the selected reanalyses and is linked to the variations of different large-scale atmospheric circulation patterns (e.g., the North Atlantic Oscillation). However, the evident periods of decreasing trend during 1926-1960 and 1990-2003, which drive most of the stilling in the last century, are missing in the reanalyses and cannot be realistically modeled through multiple linear regression by only using indexes of atmospheric circulation. Therefore, this study reveals that changes in large-scale atmospheric circulation mainly drive the low-frequency variability of observed near-surface wind speed, while other factors (e.g., changes in surface roughness) are crucial for explaining the periods of strong terrestrial stilling across Sweden.
|
|
| 5. |
- Shen, Cheng, et al.
(författare)
-
Evaluation of global terrestrial near-surface wind speed simulated by CMIP6 models and their future projections
- 2022
-
Ingår i: Annals of the New York Academy of Sciences. - : Wiley. - 0077-8923 .- 1749-6632. ; 1518:1, s. 249-63
-
Tidskriftsartikel (refereegranskat)abstract
- We evaluate the performance of Coupled Model Intercomparison Project Phase 6 (CMIP6) models in simulating the observed global terrestrial near-surface wind speed (NSWS) and project its future changes under three different Shared Socioeconomic Pathways (SSPs). Results show that the CESM2 has the best ability in reproducing the observed NSWS trends, although all models examined are generally not doing well. Based on projections of CESM2, the global NSWS will decrease from 2021 to 2100 under all three SSPs. The projected NSWS declines significantly over the north of 20 degrees N, especially across North America, Europe, and the mid-to-high latitudes of Asia; meanwhile, it increases over the south of 20 degrees N. Under SSP585, there would be more light-windy days and fewer strong-windy days than those under SSP245, which leads to a significant global NSWS decline. Robust hemispheric-asymmetric changes in the NSWS could be due to the temperature gradient in the two hemispheres under global warming, with -1.2%, -3.5%, and -4.1% in the Northern Hemisphere, and 0.8%, 1.0%, and 1.5% in the Southern Hemisphere, for the near-term (2021-2040), mid-term (2041-2060), and long-term (2081-2100), respectively.
|
|
| 6. |
- Shen, Cheng, et al.
(författare)
-
March Near-Surface Wind Speed Hiatus Over China Since 2011
- 2023
-
Ingår i: Geophysical Research Letters. - 0094-8276. ; 50:15
-
Tidskriftsartikel (refereegranskat)abstract
- Previous research has extensively explored the "stilling" and "reversal" phenomena in annual near-surface wind speed (NSWS). However, the variations in the strengths of these phenomena between different months remain unclear. Here the monthly changes in observed NSWS from 769 stations across China during 1979-2020 were analyzed. The analysis reveals a consistent decline in NSWS that ceased around 2011, followed by an increasing trend detected in all months except March, where a distinct hiatus is observed. The hiatus in March NSWS is primarily attributed to a significant reduction in NSWS over North and Northwest China. This reduction can be linked to the southward shift of the East Asian subtropical jet (EASJ), which resulted in a decreased meridional temperature gradient and weakened transient eddy activities across northern China. These findings emphasize the importance of considering changes in the EASJ to gain a comprehensive understanding of NSWS changes at regional scale.
|
|
| 7. |
|
|
| 8. |
- Vaziri-Sani, Fariba, et al.
(författare)
-
Phenotypic expression of factor H mutations in patients with atypical hemolytic uremic syndrome
- 2006
-
Ingår i: Kidney International. - : Nature Publishing Group. - 0085-2538 .- 1523-1755. ; 69:6, s. 981-988
-
Tidskriftsartikel (refereegranskat)abstract
- We investigated the phenotypic expression of factor H mutations in two patients with atypical hemolytic uremic syndrome (HUS). Factor H in serum was assayed by rocket immunoelectrophoresis, immunoblotting, and double immunodiffusion and in tissue by immunohistochemistry. Functional activity was analyzed by hemolysis of sheep erythrocytes and binding to endothelial cells. A homozygous mutation in complement control protein (CCP) domain 10 of factor H was identified in an adult man who first developed membranoproliferative glomerulonephritis and later HUS. C3 levels were very low. The patient had undetectable factor H levels in serum and a weak factor H 150 kDa band. Double immunodiffusion showed partial antigenic identity with factor H in normal serum owing to the presence of factor H-like protein 1. Strong specific labeling for factor H was detected in glomerular endothelium, mesangium and in glomerular and tubular epithelium as well as in bone marrow cells. A heterozygous mutation in CCP 20 of factor H was found in a girl with HUS. C3 levels were moderately decreased at onset. Factor H levels were normal and a normal 150 kDa band was present. Double immunodiffusion showed antigenic identity with normal factor H. Factor H labeling was minimal in the renal cortex. Factor H dysfunction was demonstrated by increased sheep erythrocyte hemolysis and decreased binding to endothelial cells. In summary, two different factor H mutations associated with HUS were examined: in one, factor H accumulated in cells, and in the other, membrane binding was reduced.
|
|
| 9. |
- Zhang, G. F., et al.
(författare)
-
Rapid urbanization induced daily maximum wind speed decline in metropolitan areas: A case study in the Yangtze River Delta (China)
- 2022
-
Ingår i: Urban Climate. - : Elsevier BV. - 2212-0955. ; 43
-
Tidskriftsartikel (refereegranskat)abstract
- Wind extremes cause many environmental and natural hazard related problems globally, particularly in heavily populated metropolitan areas. However, the underlying causes of maximum wind speed variability in urbanized regions remain largely unknown. Here, we investigated how rapid urbanization in the Yangtze River Delta (YRD), China, impacted daily maximum wind speed (DMWS) between 1990 and 2015, based on near-surface (10 m height) DMWS observations, reanalysis datasets, and night-time lighting data (a proxy for urbanization). The station observation shows that annual DMWS in the YRD significantly (p < 0.05) declined during 1990-2015, by -0.209 m s(-1) decade(-1), while slightly (p > 0.1) positive trends were found in NCEP-NCAR1 (+0.048 m s(-1) decade(-1)) and ERA5 (+0.027 m s(-1) decade(-1)). An increasing divergence between the reanalysis output and the station observation since 2005 was found, and those stations located in areas with high rates of urbanization show the strongest negative annual DMWS trend, implying the key role of urbanization in weakening DMWS. This finding is supported by sensitivity experiments conducted using a regional climate model (RegCM4) forced with both 1990 and 2015 land-use and land-cover (LULC) data, where the simulated DMWS using the 2015 LULC data was lower than that simulated using the 1990 LULC data.
|
|
| 10. |
- Zhou, Chunlue, et al.
(författare)
-
HomogWS-se: a century-long homogenized dataset of near-surface wind speed observations since 1925 rescued in Sweden
- 2022
-
Ingår i: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 14:5, s. 2167-2177
-
Tidskriftsartikel (refereegranskat)abstract
- Creating a century-long homogenized near-surface wind speed observation dataset is essential to improve our current knowledge about the uncertainty and causes of wind speed stilling and recovery. Here, we rescued paper-based records of wind speed measurements dating back to the 1920s at 13 stations in Sweden and established a four-step homogenization procedure to generate the first 10-member centennial homogenized wind speed dataset (HomogWS-se) for community use. Results show that about 38 % of the detected change points were confirmed by the known metadata events, and the average segment length split by the change points is similar to 11.3 years. Compared with the raw wind speed series, the homogenized series is more continuous and lacks significant non-climatic jumps. The homogenized series presents an initial wind speed stilling and subsequent recovery until the 1990s, whereas the raw series fluctuates with no clear trend before the 1970s. The homogenized series shows a 25 % reduction in the wind speed stilling during 1990-2005 than the raw series, and this reduction is significant when considering the homogenization uncertainty. The homogenized wind speed series exhibits a significantly stronger correlation with the North Atlantic oscillation index than that of the raw series (0.54 vs. 0.29). These results highlight the importance of the century-long homogenized series in increasing our ability to detect and attribute multidecadal variability and changes in wind speed. The proposed homogenization procedure enables other countries or regions to rescue their early climate data and jointly build global long-term high-quality datasets. HomogWS-se is publicly available from the Zenodo repository at (Zhou et al., 2022).
|
|
