417 research outputs found
Cerebral microvascular endothelial glycocalyx damage, its implications on the bloodâbrain barrier and a possible contributor to cognitive impairment
Response to There is little evidence that the endothelial glycocalyx has a specific role in glomerular permeability of albumin
Short-period line profile and light variations in the Beta Cephei star 19 Monocerotis
We present an analysis of 555 high-dispersion echelle spectra of 19 Mon obtained from two sites as well as 115 Strömgren uvby observations. We show that three periodicities are present at 5.229 94, 0.170 19 and 4.889 56 cycle dâ1. The first periodicity has by far the largest amplitude. Photometric amplitude ratios and phase differences indicate an â=2 mode, while the line profile variations unequivocally point to â=2,m=-2. Because of the low amplitudes of the other two modes, very little can be said concerning them. Although 19 Mon was originally selected on the basis of its classification as a marginal Be star, the Be nature of the star is not supported by our observation
Adiponectin reduces glomerular endothelial glycocalyx disruption and restores glomerular barrier function in a mouse model of type 2 diabetes
Adiponectin has vascular anti-inflammatory and protective effects. Although adiponectin protects against the development of albuminuria, historically, the focus has been on podocyte protection within the glomerular filtration barrier (GFB). The first barrier to albumin in the GFB is the endothelial glycocalyx (eGlx), a surface gel-like barrier covering glomerular endothelial cells (GEnCs). In diabetes, eGlx dysfunction occurs before podocyte damage; hence, we hypothesized that adiponectin could protect from eGlx damage to prevent early vascular damage in diabetic kidney disease (DKD). Globular adiponectin (gAd) activated AMPK signaling in human GEnCs through AdipoR1. It significantly reduced eGlx shedding and the TNF-αâmediated increase in syndecan-4 (SDC4) and MMP2 mRNA expression in GEnCs in vitro. It protected against increased TNF-α mRNA expression in glomeruli isolated from db/db mice and against expression of genes associated with glycocalyx shedding (namely, SDC4, MMP2, and MMP9). In addition, gAd protected against increased glomerular albumin permeability (Psâalb) in glomeruli isolated from db/db mice when administered intraperitoneally and when applied directly to glomeruli (ex vivo). Psâalb was inversely correlated with eGlx depth in vivo. In summary, adiponectin restored eGlx depth, which was correlated with improved glomerular barrier function, in diabetes
In vitro assessment of human islet vulnerability to instant blood mediated inflammatory reaction (IBMIR) and its use to demonstrate a beneficial effect of tissue culture
Culture of human pancreatic islets is now routinely carried out prior to clinical islet allotransplantation, using conditions that have been developed empirically. One of the major causes of early islet destruction after transplantation is the process termed instant blood mediated inflammatory reaction (IBMIR). The aim of this study was to develop in vitro methods to investigate IBMIR and apply them to the culture conditions used routinely in our human islet isolation laboratory. Freshly isolated or pre-cultured (24 h, 48 h) human islets were incubated in either ABO compatible allogeneic human blood or Hank's buffered salt solution (HBSS) for 1 h at 37 degrees C. Tissue factor (TF) expression and leukocyte migration were assessed by light microscopy. TF was also quantified by ELISA. To assess beta cell function, glucose stimulated insulin secretion (GSIS) assay was carried out. The extent of islet beta cell damage was quantified using a proinsulin assay. Islets cultured for 24 h had higher GSIS when compared to freshly isolated or 48 h pre-cultured islets. Freshly isolated islets had significantly higher TF content than 24 h and 48 h pre-cultured islets. Incubation of freshly isolated human islets in allogeneic human blood released 6.5 fold higher level of proinsulin in comparison to freshly isolated human islets in HBSS. The high level of proinsulin released was significantly attenuated when pre-cultured islets (24 h or 48 h) were exposed to fresh blood. Histological examination of fresh islets in blood clot showed that some islets were fragmented, showing signs of extra-islet insulin leakage and extensive neutrophil infiltration and necrosis. These features were markedly reduced when the islets were cultured for 24 h. These results suggest that our standard 24 h islet culture is markedly beneficial in attenuating IBMIR, as evidenced by increased GSIS, lower content of TF, decrease islet fragmentation and proinsulin release
Lipopolysaccharide promotes Drp1-dependent mitochondrial fission and associated inflammatory responses in macrophages
Mitochondria have a multitude of functions, including energy generation and cell signaling. Recent evidence suggests that mitochondrial dynamics (i.e. the balance between mitochondrial fission and fusion) also regulate immune functions. Here, we reveal that lipopolysaccharide (LPS) stimulation increases mitochondrial numbers in mouse bone marrowâderived macrophages (BMMs) and human monocyteâderived macrophages. In BMMs, this response requires Tollâlike receptor 4 (Tlr4) and the TLR adaptor protein myeloid differentiation primary response 88 (MyD88) but is independent of mitochondrial biogenesis. Consistent with this phenomenon being a consequence of mitochondrial fission, the dynaminârelated protein 1 (Drp1) GTPase that promotes mitochondrial fission is enriched on mitochondria in LPSâactivated macrophages and is required for the LPSâmediated increase in mitochondrial numbers in both BMMs and mouse embryonic fibroblasts. Pharmacological agents that skew toward mitochondrial fusion also abrogated this response. LPS triggered acute Drp1 phosphorylation at serine 635 (S635), followed by sustained Drp1 dephosphorylation at serine 656 (S656), in BMMs. LPSâinduced S656 dephosphorylation was abrogated in MyD88âdeficient BMMs, suggesting that this postâtranslational modification is particularly important for Tlr4âinducible fission. Pharmacological or genetic targeting of Tlr4âinducible fission had selective effects on inflammatory mediator production, with LPSâinducible mitochondrial fission promoting the expression and/or secretion of a subset of inflammatory mediators in BMMs and mouse embryonic fibroblasts. Thus, triggering of Tlr4 results in MyD88âdependent activation of Drp1, leading to inducible mitochondrial fission and subsequent inflammatory responses in macrophages.Ronan Kapetanovic, Syeda Farhana Afroz, Divya Ramnath, Grace MEP Lawrence, Takashi Okada, James EB Curson, Jost de Bruin, David P Fairlie, Kate Schroder, Justin C St John, Antje Blumenthal, Matthew J Swee
Sufism and Liberation across the Indo-Afghan Border: 1880-1928
How do we understand links between sufism and pro-egalitarian revolutionary activism in the early twentieth century; and how did upland compositions of self and community help constitute revolutionary activism in South Asia more broadly? Using Pashto poetry as my archive I integrate a history of radical egalitarian thought and political practice to a holistic study of self-making; of imperial spatiality; and of shifting gradients of power in the regions between Kabul and Punjab. Amid a chaotic rise of new practices of imperial and monarchic hegemony around the turn of the twentieth century, I argue, older sedimentations of âdevotee selfhoodâ in the high valleys of eastern Afghanistan gave rise, in social spaces preserved by self-reflexive poetic practice and circulation, to conscious desires for avoidance of all forms of hierarchy or sovereignty, in favour of a horizontal politics of reciprocity. Such inchoate drives for freedom later played a role in constituting anti-statist revolutionary subjectivities across great geographical and social distance. From upland sufi roots they rippled outward to intersect with the work of transnational socialist and anti-imperialist militants in Indian nationalist circles too; and even influenced scholars at the heart of the nascent Afghan nation-state
Clinical risk stratification of paediatric renal transplant recipients using C1q and C3d fixing of de novo donor-specific antibodies
Introduction: We have previously shown that children who developed de novo donor-specific human leukocyte antigen (HLA) antibodies (DSA) had greater decline in allograft function. We hypothesised that patients with complement-activating DSA would have poorer renal allograft outcomes. Methods: A total of 75 children developed DSA in the original study. The first positive DSA sample was subsequently tested for C1q and C3d fixing. The primary event was defined as 50% reduction from baseline estimated glomerular filtration rate and was analysed using the KaplanâMeier estimator. Results: Of 65 patients tested, 32 (49%) and 23 (35%) tested positive for C1q and C3d fixing, respectively. Of the 32 C1q-positive (c1q+) patients, 13 (41%) did not show concomitant C3d fixing. The mean fluorescence intensity values of the original immunoglobulin G DSA correlated poorly with complement-fixing positivity (C1q: adjusted R2 0.072; C3d: adjusted R2 0.11; p < 0.05). C1q+ antibodies were associated with acute tubulitis [0.75 ± 0.18 (C1q+) vs. 0.25 ± 0.08 (C1qâ) episodes per patient (mean ± standard error of the mean; p < 0.05] but not with worse long-term renal allograft dysfunction (median time to primary event 5.9 (C1q+) vs. 6.4 (C1qâ) years; hazard ratio (HR) 0.74; 95% confidence ratio (CI) 0.30â1.81; p = 0.58]. C3d-positive (C3d+) antibodies were associated with positive C4d histological staining [47% (C3d+) vs. 20% (C3dâ); p = 0.04] and with significantly worse long-term allograft dysfunction [median time to primary event: 5.6 (C3d+) vs. 6.5 (C3dâ) years; HR 0.38; 95% CI 0.15â0.97; p = 0.04]. Conclusion: Assessment of C3d fixing as part of prospective HLA monitoring can potentially aid stratification of patients at the highest risk of long-term renal allograft dysfunction
The Raf-1 inhibitor GW5074 and dexamethasone suppress sidestream smoke-induced airway hyperresponsiveness in mice
© 2008 Lei et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
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