Search

L-selectin shedding induced by various cytokines is crucial in activating neutrophils (PMNs) in inflammatory cascade. While the real-time shedding in vivo lasts ~10 min after PMN activation, the impact of time-dependent shedding on binding kinetics of membrane-remaining L-selectins to its ligands is poorly understood at transient or steady state. Here, we developed an in vitro L-selectin shedding dynamics approach, together with competitive assays of cell adhesion, and proposed a theoretical model for quantifying the impact of real-time shedding on the binding kinetics of membrane-remaining L-selectins to P-selectin glycoprotein ligand-1 (PSGL-1). Our data indicated that the extent of L-selectin shedding on PMA activation is higher, but the terminating time is longer for Jurkat cells than those for human PMNs. Meanwhile, fMLF or IL-8 stimulation yields the longer terminating time than that on PMA stimulation but results in a similar shedding extent for PMNs. L-selectin shedding reduces L-selectin-PSGL-1-mediated cell adhesion in three ways: decreasing membrane-anchored L-selectins, increasing soluble L-selectins competitively binding to ligands, and presenting conformational alteration of membrane-remaining L-selectins themselves. Compared with those on intact cells, the binding affinities of membrane-remaining L-selectin-PSGL-1 pairs were all enhanced at initial and lowered at the late shedding phase for both PMN and Jurkat cells even with varied transition time points. The rolling velocities of both PMNs and Jurkat cells were increased following mechanically or biochemically induced shedding of L-selectin under shear flow. These findings help to further our understanding of the function of time-dependent L-selectin shedding during the inflammation cascade.

Objective: To evaluate the outcomes of splenectomy in the treatment of relapsed/refractory autoimmune hemolytic anemia (AIHA). Methods: Retrospective analysis was performed in 30 cases with relapsed/refractory AIHA who were treated with splenectomy in our hospital. The pre- and post-operative blood routine indexes and responses were followed up. Results: Among the 30 relapsed/refractory AIHA patients, 20 were pure AIHA (including 13 patients with warm antibody AIHA, 2 with warm-cold double antibody AIHA and 5 with Coombs negative AIHA) and 10 were Evans syndrome. The short-term response was evaluated 10-14 days after operation, and the overall response rate (ORR) of short-term response was 90% [12 cases in complete response (CR), 6 cases in partial response (PR)] in 20 therapeutic evaluable cases. Among 13 patients with long-term follow-up data, except 3 patients with Evans syndrome died (2 cases were refractory to splenectomy, 1 case relapsed after surgery), the ORR of 10 patients with relapsed/refractory pure AIHA at 6 months and 12 months were 90% (9/10) and 70% (7/10), respectively, with a median follow-up of 14 (4-156) months. At the end of follow-up, 3 cases had maintained CR for more than 3 years. Conclusion: The short-term response of splenectomy as a second-line treatment for relapsed/refractory AIHA is satisfactory, and long-term outcome of splenectomy is up to 70% at 1 year. Approximately one-third of patients could maintain sustained remission.

Background: Hepatocellular carcinoma (HCC) has a poor prognosis with low chemotherapeutic efficiency to medications except to sorafenib. Previous studies showed that adverse events (AEs) of sorafenib can predict therapy efficacy to HCC. The aim of the study is to evaluate the early efficacy and AEs of sorafenib therapy., Methods: The database of HCC patients receiving sorafenib at Taichung Veterans General Hospital during the period from June 2012 to October 2016 was analyzed. All HCC cases were Barcelona Clinic Liver Cancer (BCLC) classification stage C. The early efficacy of sorafenib was classified according to the mRECIST criteria as either partial response (PR), stable disease (SD) or progressive disease (PD). Responses were recorded within 6 weeks after the start of sorafenib treatment. AEs were defined as the appearance of hand-foot skin reaction (HFSR), hypertension (HTN) and diarrhea. Exclusion criteria were poor performance status, poor drug compliance, discontinued follow-up or mortality occurring within 1 day after medication., Results: From a total of 222 subjects, eight cases (3.6%) were classified as PR, 82 cases (36.9%) SD, and 132 cases (59.5%) PD. The PR group had the highest ratio of HFSR (62.4%) and hypertension (37.5%). Pooling cases of PR and SD together, the presence of HFSR adjusted odd ratio (aOR) 2.80, 95% confidence interval (CI) 1.52 - 5.16) and diarrhea (aOR 3.42, 95% CI 1.67 - 7.01) were good predictors of favorable responses to sorafenib therapy., Conclusions: HFSR and diarrhea are good predictors of early therapy efficacy to the sorafenib treatment.

Flowing polymorphonuclear neutrophils (PMNs) are forced to recruit toward inflamed tissue and adhere to vascular endothelial cells, which is primarily mediated by the binding of β 2 -integrins to ICAM-1. This process is distinct among different organs such as liver and brain; however, the underlying kinetic and mechanical mechanisms regulating tissue-specific recruitment of PMNs remain unclear. Here, binding kinetics measurement showed that ICAM-1 on murine hepatic sinusoidal endothelial cells (LSECs) bound to lymphocyte function-associated antigen-1 (LFA-1) with higher on- and off-rates but lower effective affinity compared with macrophage-1 antigen (Mac-1), whereas ICAM-1 on cerebral endothelial cells (BMECs or bEnd.3 cells) bound to LFA-1 with higher on-rates, similar off-rates, and higher effective affinity compared with Mac-1. Physiologically, free crawling tests of PMN onto LSEC, BMEC, or bEnd.3 monolayers were consistent with those kinetics differences between two β 2 -integrins interacting with hepatic sinusoid or cerebral endothelium. Numerical calculations and Monte Carlo simulations validated tissue-specific contributions of β 2 -integrin-ICAM-1 kinetics to PMN crawling on hepatic sinusoid or cerebral endothelium. Thus, this work first quantified the biophysical regulation of PMN adhesion in hepatic sinusoids compared with cerebral endothelium.

This research is to explore the effects of traditional Chinese medicine Ginseng-spikenard heart-nourishing capsule on the inactivation of c-type Kv1.4 channels (Kv1.4∆N) in Xenopus laevis oocytes with two-electrode voltageclamp technique. Defolliculated oocytes (stage V-VI) were injected with transcribed cRNAs of ferret Kv1.4δN channels. During recording, oocytes were continuously perfused with ND96 solution (control group) and solution prepared from Ginseng-spikenard heart-nourishing capsule (experimental group). Results found that, at the command potential of +50 mV, the current of experimental group was reduced to 48.33±4.0% of that in control group. The inactivation time constants in control and experimental groups were 2962.56±175.35 ms and 304.13±36.22ms, respectively (P<0.05, n=7). The recovery time of fKv1.4∆N channel after inactivation in control group and experimental groups was 987±68.39 ms and 1734.15±98.45 ms, respectively (P<0.05, n=5). Ginseng-spikenard heart-nourishing capsule can inhibit the Kv1.4δN channel, which may be one of the mechanisms of underlying antiarrhythmia.

Background: Ventricular arrhythmia (VA) is one of the most common complications of myocardial infarction (MI), and ventricular tachycardia and fibrillation are the main causes for sudden cardiac death. This study aimed to explore the effect of ramipril on the occurrence of VA and its mechanism after MI in rabbits., Methods: Twenty-four New Zealand rabbits purchased from the Wuhan Laboratory Animal Research Center were divided into three groups: sham-operated (SHAM) group (n=8), MI group (n=8) and MI with ramipril (RAM) group (n=8). Rabbits in the SHAM group received a median sternotomy without ligation of the left ventricular coronary artery. Rabbits in the MI and RAM groups received a median sternotomy followed by ligation of the left coronary artery. The successful anterior MI was confirmed by elevation of the ST segment with more than 0.2 mV in lead II and III. After MI, rabbits in the RAM group were fed with intragastric ramipril (1 mg/kg per day) for 12 weeks. Before and 12 weeks after MI in the three groups, ventricular tachycardia or fibrillation (VT/VF) episodes and MAP in cadiocytes of the epicardium, mid-myocardium and endocardium were recorded by a multichannel physiograph. Student's t test and ANOVA were used for statistical analysis., Results: VT/VF episodes were decreased more markedly in the RAM group than in the MI group after 12 weeks (2.6±0.8 vs. 12.4±2.9, P<0.05). Twelve weeks after MI, the duration of repolarization for 90% (APD90) of three-tier ventricular myocytes in the MI group was longer than that before MI (258.2±21.1 vs. 230.1±23.2, 278.0±23.8 vs. 245.8±25.4, 242.6±22.7 vs. 227.0±21.7, P<0.05). However, the APD90 was not significantly different at 12 weeks before and after MI in the RAM group (P>0.05). Moreover, the transmural dispersion of repolarization (TDR) was increased more markedly 12 weeks after MI in the MI group than in the SHAM and RAM groups (36.2±10.2 vs. 18.7±6.2, 24.9±8.7, P<0.05). But the TDR was not significantly different between the RAM and SHAM groups (18.7±6.2 vs. 24.9±8.7, P>0.05)., Conclusion: Ramipril may reduce the incidence of malignant ventricular arrhythmia via improvement of transmembrance repolarization heterogeneity after MI.