Role of viral RNA and lipid in the adverse events associated with the 2010 Southern Hemisphere trivalent influenza vaccine

In Australia, during the 2010 Southern Hemisphere (SH) influenza season, there was an unexpected increase in post-marketing adverse event reports of febrile seizures (FS) in children under 5 years of age shortly after vaccination with the CSL 2010 SH trivalent influenza vaccine (CSL 2010 SH TIV) compared to previous CSL TIVs and other licensed 2010 SH TIVs. In an accompanying study, we described the contribution to these adverse events of the 2010 SH influenza strains as expressed in the CSL 2010 SH TIV using in vitro cytokine/chemokine secretion from whole blood cells and induction of NF-κB activation in HEK293 reporter cells. The aim of the present study was to identify the root cause components that elicited the elevated cytokine/chemokine and NF-κB signature. Our studies demonstrated that the pyrogenic signal was associated with a heat-labile, viral-derived component(s) in the CSL 2010 SH TIV. Further, it was found that viral lipid-mediated delivery of short, fragmented viral RNA was the key trigger for the increased cytokine/chemokine secretion and NF-κB activation. It is likely that the FS reported in children <5 years were due to a combination of the new influenza strains included in the 2010 SH TIV and the CSL standard method of manufacture preserving strain-specific viral components of the new influenza strains (particularly B/Brisbane/60/2008 and to a lesser extent H1N1 A/California/07/2009). These combined to heighten immune activation of innate immune cells, which in a small proportion of children <5 years of age is associated with the occurrence of FS. The data also demonstrates that CSL TIVs formulated with increased levels of splitting agent (TDOC) for the B/Brisbane/60/2008 strain can attenuate the pro-inflammatory signals in vitro, identifying a potential path forward for generating a CSL TIV indicated for use in children <5 years.     

Mesenteric pulsatility index analysis predicts response to azathioprine in patients with Crohn's disease

OBJECTIVE: Mesenteric blood flow measurement has been found to predict relapse after steroid-induced remission in patients with Crohn's disease (CD) and ulcerative colitis (UC). Therefore, we assessed prospectively the possible relationship between changes in mesenteric blood flow and prognosis in chronically active patients with need of immunosuppressive therapy with azathioprine (AZA) or 6-mercaptopurine (6-MP). METHODS: Doppler ultrasound (DUS) measurements of the pulsatility index (PI) of the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) were performed in 52 patients with chronically active inflammatory bowel disease (CD 31 patients; UC 21 patients) before beginning therapy with AZA/6-MP (US1) and during clinical remission (CD activity index <150, Truelove index score I) (US2). Patients were weaned from concomitant therapy with corticosteroids as soon as possible and were followed up for 12 months. RESULTS: After 1 year, 16 patients with CD (51.6%) and 13 patients with UC (61.9%) were in remission, whereas 23 patients had recurrent disease or had undergone surgery. A decreased SMA PI at US2 predicted clinical relapse in all patients with CD [100%; P < 0.001; mean (+/-SD) 77 +/- 67 d after US1], but only 4 of 8 patients (50%; difference not significant; mean 84 +/- 75 d after US1) with UC. Conversely, an increase of SMA PI was associated with sustained remission in the majority of CD patients (12/16 patients; 75%; P < 0.002), but in only 7 of 13 patients (54%) with UC. Flow measurements in the IMA and postprandial values for both arteries were less reliable. CONCLUSION: Repeated DUS measurements of the SMA PI predict response to AZA/6-MP in patients with chronic active CD.     

Local application of lactoferrin promotes bone regeneration in a rat critical‐sized calvarial defect model as demonstrated by micro‐CT and histological analysis

Lactoferrin is a multifunctional glycoprotein with therapeutic potential for bone tissue engineering. The aim of this study was to assess the efficacy of local application of lactoferrin on bone regeneration. Five‐millimetre critical‐sized defects were created over the right parietal bone in 64 Sprague–Dawley rats. The rats were randomized into four groups: group 1 (n  =  20) had empty defects; group 2 (n  =  20) had defects grafted with collagen gels (3 mg/ml); group 3 (n  =  20) had defects grafted with collagen gels impregnated with bovine lactoferrin (10 μg/gel); and group 4 (n  =  4) had sham surgeries (skin and periosteal incisions only). The rats were sacrificed at 4 or 12 weeks post‐operatively, and the calvaria were excised and evaluated with micro‐CT (Skyscan 1172) followed by histology. The bone volume fraction (BV/TV) was higher in lactoferrin‐treated animals at both timepoints, with groups 1, 2, 3 and 4 measuring 10.5  ±  1.1%, 8.6  ±  1.4%, 16.5  ±  0.6% and 24.27  ±  2.6%, respectively, at 4 weeks (P  <  0.05); and 12.2  ±  1.3%, 13.6  ±  1.5%, 21.9  ±  1.2% and 29.3  ±  0.8%, respectively, at 12 weeks (P  <  0.05). Histological analysis revealed that the newly formed bone within the calvarial defects of all groups was a mixture of woven and lamellar bone, with more bone in the group treated with lactoferrin at both timepoints. Our study demonstrated that local application of lactoferrin significantly increased bone regeneration in a rat critical‐sized calvarial defect model. The profound effect of lactoferrin on bone regeneration has therapeutic potential to improve the poor clinical outcomes associated with bony non‐union. LF In Vivo JTERM Authors Contributions. Copyright © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons, Ltd.     

l-Glutamine and Whole Protein Restore First-Phase Insulin Response and Increase Glucagon-Like Peptide-1 in Type 2 Diabetes Patients

l-glutamine triggers glucagon-like peptide-1 (GLP-1) release from L cells in vitro and when ingested pre-meal, decreases postprandial glycaemia and increases circulating insulin and GLP-1 in type 2 diabetes (T2D) patients. We aimed to evaluate the effect of oral l-glutamine, compared with whole protein low in glutamine, on insulin response in well-controlled T2D patients. In a randomized study with a crossover design, T2D patients (n = 10, 6 men) aged 65.1 ± 5.8, with glycosylated hemoglobin (HbA1c) 6.6% ± 0.7% (48 ± 8 mmol/mol), received oral l-glutamine (25 g), protein (25 g) or water, followed by an intravenous glucose bolus (0.3 g/kg) and hyperglycemic glucose clamp for 2 h. Blood was frequently collected for analyses of glucose, serum insulin and plasma total and active GLP-1 and area under the curve of glucose, insulin, total and active GLP-1 excursions calculated. Treatments were tested 1–2 weeks apart. Both l-glutamine and protein increased first-phase insulin response (p ≤ 0.02). Protein (p = 0.05), but not l-glutamine (p = 0.2), increased second-phase insulin response. Total GLP-1 was increased by both l-glutamine and protein (p ≤ 0.02). We conclude that oral l-glutamine and whole protein are similarly effective in restoring first-phase insulin response in T2D patients. Larger studies are required to further investigate the utility of similar approaches in improving insulin response in diabetes.     

Bile acids regulate hepatic low density lipoprotein receptor activity in the hamster by altering cholesterol flux across the liver.

The effect of different bile acids on receptor-dependent and receptor-independent low density lipoprotein (LDL) uptake in the liver and intestine was investigated. When fed at the 0.1% level for three weeks, cholic acid and chenodeoxycholic acid suppressed hepatic cholesterol synthesis in the rat by 80% and 50%, respectively, while ursodeoxycholic acid had no effect. In contrast, hepatic cholesteryl ester levels, rates of hepatic LDL transport, and concentrations of plasma LDL-cholesterol were not affected by bile acid feeding in this species. Cholic acid and chenodeoxycholic acid also suppressed hepatic cholesterol synthesis in the hamster. However, since basal rates of hepatic cholesterol synthesis in this species, as in man, are very low, the absolute reduction in hepatic synthesis could not compensate for the change in hepatic sterol balance induced by bile acid feeding. Hence, in the hamster the feeding of cholic acid and chenodeoxycholic acid increased hepatic cholesteryl ester levels 660% and 39%, respectively, reduced hepatic receptor-dependent LDL uptake by 50% and 32%, respectively, and elevated plasma LDL-cholesterol levels by 160% and 50%, respectively. Ursodeoxycholic acid feeding did not alter any of these processes, and none of the bile acids changed the rate of hepatic receptor-independent LDL transport. In the intestine, none of the bile acids altered rates of cholesterol synthesis or LDL uptake. When cholic acids, chenodeoxycholic acid, or ursodeoxycholic acid was infused continuously for 8 hr in supranormal amounts into control hamsters or rats or into animals pretreated with cholestyramine, there were no changes in LDL transport or any other parameter of hepatic cholesterol metabolism. Thus, these studies indicated that cholic acid and chenodeoxycholic acid have no acute, direct effect on rates of receptor-dependent LDL transport or cholesterol synthesis but do alter these processes indirectly by inducing changes in cholesterol balance across the liver. Ursodeoxycholic acid, in contrast, does not affect these processes either directly or indirectly and so causes no change in plasma LDL levels.     

Prospective assessment after pediatric cardiac ablation: demographics, medical profiles, and initial outcomes

INTRODUCTION: A multicenter prospective study was designed and implemented to assess the short- and longer-term results and risks associated with radiofrequency (RF) ablation in children. METHODS AND RESULTS: Patients recruited for the study were aged 0 to 16 years with supraventricular tachycardia due to accessory pathways or AV nodal reentrant tachycardia (AVNRT), excluding patients with nontrivial congenital heart disease. A national registry also was established, and contributing centers were encouraged to enroll all pediatric patients, aged 0 to 21 years, undergoing ablation at their center. This report summarizes acute results of these procedures. For analysis, subjects were divided into three groups: the prospective cohort (n = 481), cohort-eligible registry participants (n = 504), and not cohort eligible registry participants (n = 1,776). Prospectively enrolled cohort patients were similar to cohort-eligible patients in terms of demographic and other patient characteristics. Overall success rates for RF ablation were high (95.7%), with higher success rates for left-sided and particularly left free-wall pathways (97.8%) than right free-wall pathways (90.8%). Complications of both electrophysiologic study and RF ablation were infrequent (4.2% and 4.0%, respectively), and there were no deaths. AV block was uncommon overall (1.2%) and was limited to ablation in AVNRT (2.1%) and septal accessory pathways (3.0%). CONCLUSION: Despite the multicenter and prospective design, the study demonstrates high success rates and low complication rates, which are comparable to prior single-center retrospective studies. These results may serve as the current best benchmark for expected results in the pediatric population, aged 0 to 16 years, both in terms of acute success rates and the occurrence of complications.     

Role of leisure-time physical activity in nonalcoholic fatty liver disease: a population-based study

Physical activity (PA) is commonly recommended for nonalchoholic fatty liver disease (NAFLD) patients. However, there is limited evidence on the independent role of PA in NAFLD. The aim of this study was to examine the association between PA and NAFLD. We conducted a cross-sectional study of a subsample (n = 375) of the Israeli National Health and Nutrition Survey. Exclusion criteria were any known etiology for liver disease. Participants underwent an abdominal ultrasound examination; biochemical tests, including leptin, adiponectin, and resistin; and the noninvasive biomarker SteatoTest and anthropometric evaluations. A semiquantitative food frequency questionnaire and a detailed PA questionnaire were administered. Three hundred forty-nine patients (52.7% men, 30.9% primary NAFLD) were included. The NAFLD group engaged in less aerobic, resistance, or other kinds of PA (P 相似文献   

Soluble α-synuclein–antibody complexes activate the NLRP3 inflammasome in hiPSC-derived microglia

Parkinson’s disease is characterized by accumulation of α-synuclein (αSyn). Release of oligomeric/fibrillar αSyn from damaged neurons may potentiate neuronal death in part via microglial activation. Heretofore, it remained unknown if oligomeric/fibrillar αSyn could activate the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome in human microglia and whether anti-αSyn antibodies could prevent this effect. Here, we show that αSyn activates the NLRP3 inflammasome in human induced pluripotent stem cell (hiPSC)-derived microglia (hiMG) via dual stimulation involving Toll-like receptor 2 (TLR2) engagement and mitochondrial damage. In vitro, hiMG can be activated by mutant (A53T) αSyn secreted from hiPSC-derived A9-dopaminergic neurons. Surprisingly, αSyn–antibody complexes enhanced rather than suppressed inflammasome-mediated interleukin-1β (IL-1β) secretion, indicating these complexes are neuroinflammatory in a human context. A further increase in inflammation was observed with addition of oligomerized amyloid-β peptide (Aβ) and its cognate antibody. In vivo, engraftment of hiMG with αSyn in humanized mouse brain resulted in caspase-1 activation and neurotoxicity, which was exacerbated by αSyn antibody. These findings may have important implications for antibody therapies aimed at depleting misfolded/aggregated proteins from the human brain, as they may paradoxically trigger inflammation in human microglia.

Parkinson’s disease (PD) is characterized by accumulation of α-synuclein (αSyn; encoded by the SNCA gene) (1). Release of oligomeric/fibrillar αSyn from damaged neurons may potentiate neuronal cell death in part via microglial activation (2, 3). Moreover, misfolded proteins in general are thought to interact with brain microglia, triggering microglial activation that contributes to neurodegenerative disorders, although microglial phagocytosis may also initially clear aberrant proteins to afford some degree of protection (2, 4). Additionally, in Alzheimer’s disease (AD), amyloid-β peptide (Aβ) is thought to trigger similar processes in microglia (5–7); however, the mechanism for this trigger is still poorly understood.Microglial cells contribute to neuroinflammation, specifically that mediated by the inflammasome. In particular, the nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) inflammasome has been associated with several neurodegenerative disorders, although other types of inflammation may also be important in this regard (8). The NLRP3 inflammasome is a multiprotein complex that responds to cell stress and pathogenic stimuli to promote activation of caspase-1, which in turn mediates maturation and release of proinflammatory cytokines, including interleukin-1β (IL-1β) and IL-18 (9–11). NLRP3 inflammasome activation is a two-step process, involving an initial priming step and a secondary trigger. Priming involves a proinflammatory stimulus, such as endotoxin, a ligand for Toll-like receptor 4 (TLR4), that increases the abundance of NLRP3 and promotes de novo synthesis of pro–IL-1β via nuclear factor κB (11). The secondary trigger promotes inflammasome complex assembly and caspase-1 activation that in turn mediates the cleavage of pro–IL-1β and subsequent release of mature IL-1β. There are various secondary triggers, including adenosine triphosphate (ATP), microparticles, and bacterial toxins, all of which somehow lead to mitochondrial damage and release of oxidized mitochondrial DNA (11). Neuroinflammation has been reported in both human PD and AD brains (12–15), and NLRP3 inflammasome activation in particular has been observed in mouse models of PD and AD (7, 16). Importantly, in these PD models, dopaminergic (DA) neurons in the substantia nigra are resistant to damage in NLRP3-deficient mice compared with wild-type (WT) mice (16). Interestingly, a recent report identified an NLRP3 polymorphism that confers decreased risk in PD (17). Several groups have reported that fibrillar αSyn can activate the NLRP3 inflammasome in mice and in human monocytes (18–22), but it remains unknown if human brain microglia can be activated in this manner. Critically, antibodies targeting misfolded proteins are being tested in human clinical trials for several neurodegenerative diseases, including AD and PD; however, it is still unclear how antibodies to αSyn might affect this inflammatory response. In this study, we characterized the response of human induced pluripotent stem cell (hiPSC)-derived microglia (hiMG) to oligomeric/fibrillar αSyn in vitro and in vivo, using engraftment of hiMG in humanized mice. We used these immunocompromised mice because they prevent human cell rejection and express three human genes that support human cell engraftment (23). We show that αSyn and, even more so, αSyn–antibody complexes activate the NLRP3 inflammasome. Moreover, this process is further sensitized by the presence of Aβ and its cognate antibodies. These observations are of heightened interest because recent studies have shown that both misfolded Aβ and αSyn are present in several neurodegenerative disorders such as AD and Lewy body dementia (LBD), a form of dementia that can occur in the setting of PD (24–26).