105 research outputs found
Serum Neurofilament Light and Multiple Sclerosis Progression Independent of Acute Inflammation
Introduction
Efforts to explore the utility of neurofilament light (NfL) as a biomarker associated with disability
progression in multiple sclerosis (MS) have accelerated in recent years in the absence of
pharmacodynamic or treatment response markers for clinical trials or patient care.1
The International
Progressive MS Alliance stated in 2020 that serum NfL (sNfL) measurements may serve as a useful
biomarker associated with progressive MS, although further work is needed to define the relative
contributions of inflammatory activity and neurodegeneration to longitudinal changes in disability
and sNfL.2 Using data from a large clinical trial of patients with secondary progressive MS (a phase 3,
randomized, double-blind, placebo-controlled trial exploring the effect of natalizumab on disease
progression in participants with Secondary Progressive Multiple Sclerosis [ASCEND in SPMS];
NCT01416181), we investigated whether sNfL could be used as a dynamic biomarker associated with
progressive MS disease course. That is, we investigated whether longitudinal changes in sNfL
concentration were associated with disability progression measures in the absence of relapses and
magnetic resonance imaging (MRI) evidence of inflammatory activit
Lightweight conductive graphene/thermoplastic polyurethane foams with ultrahigh compressibility for piezoresistive sensing
Lightweight conductive porous graphene/thermoplastic polyurethane (TPU) foams with ultrahigh compressibility were successfully fabricated by using the thermal induced phase separation (TISP) technique. The density and porosity of the foams were calculated to be about 0.11 g cmâ3 and 90% owing to the porous structure. Compared with pure TPU foams, the addition of graphene could effectively increase the thickness of the cell wall and hinder the formation of small holes, leading to a robust porous structure with excellent compression property. Meanwhile, the cell walls with small holes and a dendritic structure were observed due to the flexibility of graphene, endowing the foam with special positive piezoresistive behaviors and peculiar response patterns with a deflection point during the cyclic compression. This could effectively enhance the identifiability of external compression strain when used as piezoresistive sensors. In addition, larger compression sensitivity was achieved at a higher compression rate. Due to high porosity and good elasticity of TPU, the conductive foams demonstrated good compressibility and stable piezoresistive sensing signals at a strain of up to 90%. During the cyclic piezoresistive sensing test under different compression strains, the conductive foam exhibited good recoverability and reproducibility after the stabilization of cyclic loading. All these suggest that the fabricated conductive foam possesses great potential to be used as lightweight, flexible, highly sensitive, and stable piezoresistive sensors
Dietary menthol-induced TRPM8 activation enhances WAT âbrowningâ and ameliorates diet-induced obesity
Beige adipocytes are a new type of recruitable brownish adipocytes, with highly mitochondrial membrane uncoupling protein 1 expression and thermogenesis. Beige adipocytes were found among white adipocytes, especially in subcutaneous white adipose tissue (sWAT). Therefore, beige adipocytes may be involved in the regulation of energy metabolism and fat deposition. Transient receptor potential melastatin 8 (TRPM8), a Ca2+-permeable non-selective cation channel, plays vital roles in the regulation of various cellular functions. It has been reported that TRPM8 activation enhanced the thermogenic function of brown adiposytes. However, the involvement of TRPM8 in the thermogenic function of WAT remains unexplored. Our data revealed that TRPM8 was expressed in mouse white adipocytes at mRNA, protein and functional levels. The mRNA expression of Trpm8 was significantly increased in the differentiated white adipocytes than pre-adipocytes. Moreover, activation of TRPM8 by menthol enhanced the expression of thermogenic genes in cultured white aidpocytes. And menthol-induced increases of the thermogenic genes in white adipocytes was inhibited by either KT5720 (a protein kinase A inhibitor) or BAPTA-AM. In addition, high fat diet (HFD)-induced obesity in mice was significantly recovered by co-treatment with menthol. Dietary menthol enhanced WAT "browning" and improved glucose metabolism in HFD-induced obesity mice as well. Therefore, we concluded that TRPM8 might be involved in WAT "browning" by increasing the expression levels of genes related to thermogenesis and energy metabolism. And dietary menthol could be a novel approach for combating human obesity and related metabolic diseases
Heart Failure with Mid-range Ejection Fractionââa Comprehension of the Disease
Heart failure is the final main battlefield of various cardiovascular diseases with huge harm, which can cause all kinds of arrhythmias and even sudden cardiac death. The 2016 ESC guidelines formally define heart failure with mid-range ejection fraction (LVEF) in the range of 40% to 49%, aiming to refine the classification of heart failure, in order to arouse the attention of clinicians to the pathophysiology of heart failure and carry out more clinical research to better guide diagnosis and treatment. At present, there are still many controversies about the pathophysiology and treatment of HFmrEF. This article explains the characteristics of patients with HFmrEF from the aspects of epidemiology, clinical characteristics, pathophysiology, and treatment. It is found that HFmrEF is more like a transition between HFpEF and HFrEF patients than a unique phenotype. Four new drugs in the field of heart failure (ARNI, SGLT-2i, SGC, OM) and atrial septal shunts have shown different degrees of benefit in the treatment of HFmrEF patients. In the future, more clinical studies on HFmrEF (such as the HFmrEF subgroup study based on the changing trend of LVEF) are needed to deepen clinicians' understanding and understanding of HFmrEF, so as to better guide treatment
Periostin Activation of Integrin Receptors on Sensory Neurons Induces Allergic Itch
Chronic allergic itch is a common symptom affecting millions of people and animals, but its pathogenesis is not fully explained. Herein, we show that periostin, abundantly expressed in the skin of patients with atopic dermatitis (AD), induces itch in mice, dogs, and monkeys. We identify the integrin αVÎČ3 expressed on a subset of sensory neurons as the periostin receptor. Using pharmacological and genetic approaches, we inhibited the function of neuronal integrin αVÎČ3, which significantly reduces periostin-induced itch in mice. Furthermore, we show that the cytokine TSLP, the application of AD-causing MC903 (calcipotriol), and house dust mites all induce periostin secretion. Finally, we establish that the JAK/STAT pathway is a key regulator of periostin secretion in keratinocytes. Altogether, our results identify a TSLP-periostin reciprocal activation loop that links the skin to the spinal cord via peripheral sensory neurons, and we characterize the non-canonical functional role of an integrin in itch
Impact of APE1/Ref-1 Redox Inhibition on Pancreatic Tumor Growth
Pancreatic cancer is especially a deadly form of cancer with a survival rate less than 2%. Pancreatic cancers respond poorly to existing chemotherapeutic agents and radiation, and progress for the treatment of pancreatic cancer remains elusive. To address this unmet medical need, a better understanding of critical pathways and molecular mechanisms involved in pancreatic tumor development, progression, and resistance to traditional therapy is therefore critical. Reductionâoxidation (redox) signaling systems are emerging as important targets in pancreatic cancer. AP endonuclease1/Redox effector factor 1 (APE1/Ref-1) is upregulated in human pancreatic cancer cells and modulation of its redox activity blocks the proliferation and migration of pancreatic cancer cells and pancreatic cancer-associated endothelial cells in vitro. Modulation of APE1/Ref-1 using a specific inhibitor of APE1/Ref-1âČs redox function, E3330, leads to a decrease in transcription factor activity for NFÎșB, AP-1, and HIF1α in vitro. This study aims to further establish the redox signaling protein APE1/Ref-1 as a molecular target in pancreatic cancer. Here, we show that inhibition of APE1/Ref-1 via E3330 results in tumor growth inhibition in cell lines and pancreatic cancer xenograft models in mice. Pharmacokinetic studies also show that E3330 attains more than10 ÎŒmol/L blood concentrations and is detectable in tumor xenografts. Through inhibition of APE1/Ref-1, the activity of NFÎșB, AP-1, and HIF1α that are key transcriptional regulators involved in survival, invasion, and metastasis is blocked. These data indicate that E3330, inhibitor of APE1/Ref-1, has potential in pancreatic cancer and clinical investigation of APE1/Ref-1 molecular target is warranted. Mol Cancer Ther; 10(9); 1698â708. ©2011 AACR
Glial fibrillary acidic protein and multiple sclerosis progression independent of acute inflammation
Background:
The clinical relevance of serum glial fibrillary acidic protein (sGFAP) concentration as a biomarker of MS disability progression independent of acute inflammation has yet to be quantified.//
Objective:
To test whether baseline values and longitudinal changes in sGFAP concentration are associated with disability progression without detectable relapse of magnetic resonance imaging (MRI) inflammatory activity in participants with secondary-progressive multiple sclerosis (SPMS).//
Methods:
We retrospectively analyzed longitudinal sGFAP concentration and clinical outcome data from the Phase 3 ASCEND trial of participants with SPMS, with no detectable relapse or MRI signs of inflammatory activity at baseline nor during the study (n = 264). Serum neurofilament (sNfL), sGFAP, T2 lesion volume, Expanded Disability Status Scale (EDSS), Timed 25-Foot Walk (T25FW), 9-Hole Peg Test (9HPT), and composite confirmed disability progression (CDP) were measured. Linear and logistic regressions and generalized estimating equations were used in the prognostic and dynamic analyses.//
Results:
We found a significant cross-sectional association between baseline sGFAP and sNfL concentrations and T2 lesion volume. No or weak correlations between sGFAP concentration and changes in EDSS, T25FW, and 9HPT, or CDP were observed.//
Conclusion:
Without inflammatory activity, changes in sGFAP concentration in participants with SPMS were neither associated with current nor predictive of future disability progression./
Antiarrhythmic effects of stimulating the left dorsal branch of the thoracic nerve in a canine model of paroxysmal atrial tachyarrhythmias
Background
Stellate ganglion nerve activity (SGNA) precedes paroxysmal atrial tachyarrhythmia (PAT) episodes in dogs with intermittent high-rate left atrial (LA) pacing. The left dorsal branch of the thoracic nerve (LDTN) contains sympathetic nerves originating from the stellate ganglia.
Objective
The purpose of this study was to test the hypothesis that high-frequency electrical stimulation of the LDTN can cause stellate ganglia damage and suppress PAT.
Methods
We performed chronic LDTN stimulation in 6 dogs with and 2 dogs without intermittent rapid LA pacing while monitoring SGNA.
Results
LDTN stimulation reduced average SGNA from 4.36 ÎŒV (95% confidence interval [CI] 4.10â4.62 ÎŒV) at baseline to 3.22 ÎŒV (95% CI 3.04â3.40 ÎŒV) after 2 weeks (P = .028) and completely suppressed all PAT episodes in all dogs studied. Tyrosine hydroxylase staining showed large damaged regions in both stellate ganglia, with increased percentages of tyrosine hydroxylaseânegative cells. The terminal deoxynucleotidyl transferase dUTP nick end labeling assay showed that 23.36% (95% CI 18.74%â27.98%) of ganglion cells in the left stellate ganglia and 11.15% (95% CI 9.34%â12.96%) ganglion cells in the right stellate ganglia were positive, indicating extensive cell death. A reduction of both SGNA and heart rate was also observed in dogs with LDTN stimulation but without high-rate LA pacing. Histological studies in the latter 2 dogs confirmed the presence of extensive stellate ganglia damage, along with a high percentage of terminal deoxynucleotidyl transferase dUTP nick end labelingâpositive cells.
Conclusion
LDTN stimulation damages both left stellate ganglia and right stellate ganglia, reduces left SGNA, and is antiarrhythmic in this canine model of PAT
Using skin sympathetic nerve activity to estimate stellate ganglion nerve activity in dogs
BACKGROUND: Stellate ganglion nerve activity (SGNA) is important in cardiac arrhythmogenesis. However, direct recording of SGNA requires access to the thoracic cavity. Skin of upper thorax is innervated by sympathetic nerve fibers originating from the stellate ganglia and is easily accessible.
OBJECTIVE: The purpose of this study was to test the hypothesis that thoracic skin nerve activity (SKNA) can be used to estimate SGNA.
METHODS: We recorded SGNA and SKNAs using surface electrocardiogram leads in 5 anesthetized and 4 ambulatory dogs. Apamin injected into the right stellate ganglion abruptly increased both right SGNA and SKNA in 5 anesthetized dogs. We integrated nerve activities and averaged heart rate in each 1-minure window over 10 minutes. We implanted a radiotransmitter to record left SGNA in 4 ambulatory dogs (2 normal, 1 with myocardial infarction, 1 with intermittent rapid atrial pacing). After 2 weeks of recovery, we simultaneously recorded the SKNA and left SGNA continuously for 30 minutes when the dogs were ambulatory.
RESULTS: There was a positive correlation [average r = 0.877, 95% confidence interval (CI) 0.732-1.000, P <.05 for each dog] between integrated skin nerve activity (iSKNA) and SGNA (iSGNA) and between iSKNA and heart rate (average r = 0.837, 95% CI 0.752-0.923, P <.05). Similar to that found in the anesthetized dogs, there was a positive correlation (average r = 0.746, 95% CI 0.527-0.964, P <.05) between iSKNA and iSGNA and between iSKNA and heart rate (average r = 0.706, 95% CI 0.484-0.927, P <.05).
CONCLUSION: SKNAs can be used to estimate SGNA in dogs
Role of Apamin-Sensitive Calcium-Activated Small-Conductance Potassium Currents on the Mechanisms of Ventricular Fibrillation in Pacing-Induced Failing Rabbit Hearts
BACKGROUND:
Ventricular fibrillation (VF) during heart failure is characterized by stable reentrant spiral waves (rotors). Apamin-sensitive small-conductance calcium-activated potassium currents (IKAS) are heterogeneously upregulated in failing hearts. We hypothesized that IKAS influences the location and stability of rotors during VF.
METHODS AND RESULTS:
Optical mapping was performed on 9 rabbit hearts with pacing-induced heart failure. The epicardial right ventricular and left ventricular surfaces were simultaneously mapped in a Langendorff preparation. At baseline and after apamin (100 nmol/L) infusion, the action potential duration (APD80) was determined, and VF was induced. Areas with a >50% increase in the maximum action potential duration (ÎAPD) after apamin infusion were considered to have a high IKAS distribution. At baseline, the distribution density of phase singularities during VF in high IKAS distribution areas was higher than in other areas (0.0035±0.0011 versus 0.0014±0.0010 phase singularities/pixel; P=0.004). In addition, high dominant frequencies also colocalized to high IKAS distribution areas (26.0 versus 17.9 Hz; P=0.003). These correlations were eliminated during VF after apamin infusion, as the number of phase singularities (17.2 versus 11.0; P=0.009) and dominant frequencies (22.1 versus 16.2 Hz; P=0.022) were all significantly decreased. In addition, reentrant spiral waves became unstable after apamin infusion, and the duration of VF decreased.
CONCLUSIONS:
The IKAS current influences the mechanism of VF in failing hearts as phase singularities, high dominant frequencies, and reentrant spiral waves all correlated to areas of high IKAS. Apamin eliminated this relationship and reduced VF vulnerability
- âŠ