Contribution of TRESK two-pore domain potassium channel to bone cancer-induced spontaneous pain and evoked cutaneous pain in rats.

Cancer-associated pain is debilitating. However, the mechanism underlying cancer-induced spontaneous pain and evoked pain remains unclear. Here, using behavioral tests with immunofluorescent staining, overexpression, and knockdown of TRESK methods, we found an extensive distribution of TRESK potassium channel on both CGRP+ and IB4+ nerve fibers in the hindpaw skin, on CGRP+ nerve fibers in the tibial periosteum which lacks IB4+ fibers innervation, and on CGRP+ and IB4+ dorsal root ganglion (DRG) neurons in rats. Moreover, we found a decreased expression of TRESK in the corresponding nerve fibers within the hindpaw skin, the tibial periosteum and the DRG neurons in bone cancer rats. Overexpression of TRESK in DRG neurons attenuated both cancer-induced spontaneous pain (partly reflect skeletal pain) and evoked pain (reflect cutaneous pain) in tumor-bearing rats, in which the relief of evoked pain is time delayed than spontaneous pain. In contrast, knockdown of TRESK in DRG neurons produced both spontaneous pain and evoked pain in naïve rats. These results suggested that the differential distribution and decreased expression of TRESK in the periosteum and skin, which is attributed to the lack of IB4+ fibers innervation within the periosteum of the tibia, probably contribute to the behavioral divergence of cancer-induced spontaneous pain and evoked pain in bone cancer rats. Thus, the assessment of spontaneous pain and evoked pain should be accomplished simultaneously when evaluating the effect of some novel analgesics in animal models. Also, this study provides solid evidence for the role of peripheral TRESK in both cancer-induced spontaneous pain and evoked cutaneous pain.

Does MRI add value in selecting patients for thrombectomy beyond the 6 h window? A matched-control analysis.

Background: Controversy exists regarding the need of advanced imaging for patient selection in the extended window. Aims: To analyze the effect of initial imaging modalities on clinical outcomes of patients underwent MT in the extended window. Methods: This was a retrospective analysis of a prospective registry, the Endovascular Treatment Key Technique and Emergency Workflow Improvement of Acute Ischemic Stroke (ANGEL-ACT) registry which was conducted at 111 hospitals between November 2017 and March 2019 in China. Primary study cohort and Guideline like cohort were identified, in each cohort, two imaging modalities for patient selection in 6 to 24 h window were defined: (1) NCCT ± CTA, (2) MRI. Guideline-like cohort were further screened based on key features of the DAWN and DEFUSE 3 trials. The primary outcome was 90 day mRS. The safety outcomes were sICH, any ICH and 90-day mortality. Results: After adjusting for covariates, there were no significant differences in 90 day mRS or any safety outcomes between two imaging modalities groups in both cohorts. All outcome measures of mixed-effects logistic regression model were consistent with propensity score matching model. Conclusion: Our results indicate that patients presented with anterior large vessel occlusion in the extended time window can potentially benefit from MT even in the absence of MRI selection. This conclusion needs to be verified by the prospective randomized clinical trials.

Activation of GDNF-ERK-Runx1 signaling contributes to P2X3R gene transcription and bone cancer pain.

Bone cancer pain is a common symptom in cancer patients with bone metastases and its underlying mechanisms remain unknown. Here, we report that Runx1 directly upregulates the transcriptional activity of P2X3 receptor (P2X3R) gene promoter in PC12 cells. Knocking down Runx1 in dorsal root ganglion (DRG) neurons suppresses the functional upregulation of P2X3R, attenuates neuronal hyperexcitability and pain hypersensitivity in tumor-bearing rats, whereas overexpressing Runx1 promotes P2X3R gene transcription in DRG neurons, induces neuronal hyperexcitability and pain hypersensitivity in naïve rats. Activation of GDNF-GFRα1-Ret-ERK signaling is required for Runx1-mediated P2X3R gene transcription in DRG neurons, and contributes to neuronal hyperexcitability and pain hypersensitivity in tumor-bearing rats. These findings indicate that the Runx1-mediated P2X3R gene transcription resulted from activation of GDNF-GFRα1-Ret-ERK signaling contributes to the sensitization of DRG neurons and pathogenesis of bone cancer pain. Our findings identify a potentially targetable mechanism that may cause bone metastasis-associated pain in cancer patients.

A rare case report of a mixed persistent proatlantal intersegmental artery.

Adults with persistent proatlantal intersegmental artery (PPIA) are rarely seen. We present a case of a special type of PPIA that was in a 57-year-old man who presented with dizziness and episodic vertigo of 9 months duration. The diagnosis relied on computed tomography angiography and digital subtraction angiography, by which a left internal carotid artery stenosis and an ipsilateral PPIA originating from the external carotid artery (ECA) was found. This special type of PPIA can be described as a ''mixed PPIA'' that originated as Type II from the ECA and coursed as Type I. The patient underwent carotid artery stenting and had no relapse during 3 months follow-up. In addition, the literatures on PPIA were reviewed.